EPA-450/3-89-003
HOSPITAL INCINERATOR OPERATOR
TRAINING COURSE:
VOLUME I
STUDENT HANDBOOK
CONTROL TECHNOLOGY CENTER
SPONSORED BY:
Emission Standards Division
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Air and Energy Engineering Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 46268
March 1989
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EPA-450/3-89-003
March 1989
HOSPITAL INCINERATOR OPERATOR TRAINING COURSE:
VOLUME I
STUDENT HANDBOOK
EPA Contract No. 68-02-4395
Work Assignment 16
Prepared by:
Midwest Research Institute
Suite 350
401 Harrison Oaks Boulevard
Gary, North Carolina 27513
Prepared for:
James A. Eddinger
Office of Air Quality Planning and Standards
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Control Technology Center
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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NOTICE
This training course is intended to provide the operator with a basic
understanding of the principles of incineration and air pollution
control. This training course is not a substitute for site-specific
hands-on training of the operator with the specific equipment to be
operated.
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DISCLAIMER
This document generally describes the proper operation of a hospital
waste incinerator. It is based on EPA's review and assessment of various
scientific and technical sources. The EPA does not represent that this
document comprehensively sets forth procedures for incinerator operation,
or that it describes applicable legal requirements, which vary according
to an incinerator's location. Proper operation of an incinerator is the
responsibility of the owner and operator.
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
iii
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ACKNOWLEDGEMENT
This document was prepared by Midwest Research Institute located in
Gary, North Carolina. Principal authors were Roy Neulicht and Linda
Chaput; Dennis Wallace, Mark Turner, and Stacy Smith were contributing
authors. Participating on the project team for the EPA were Ken Durkee
and James Eddinger of the Office of Air Quality Planning and Standards
Charles Masser of Air and Energy Engineering Research Laboratory, James
Topsale of Region III, Charles Pratt of the Air Pollution Traininq
Institute, and Justice Manning of the Center for Environmental Research
Information. Also participating on the project team were Carl York and
William Paul of the Maryland Air Management Administration.
Numerous persons were very helpful throughout this project and
provided information and comments for these course materials. Listed
below are some who deserve special acknowledgement for their'assistance.
• Mr. Larry Doucet, Doucet and Mainka, who provided a thorough
review of the student handbook.
• The following persons and facilities who provided our staff access
Messrs. Steve Shuler and Greg Swan, Joy Energy Systems; William
Tice, Rex Hospital; Dean Clark, Bio-Medical Services, Inc.;
Gary Kamp, Presbyterian—University Medical Center; Don Rust, Duke
University Medical Center; Chip Priester, Southland Exchange Joint
Venture; and Gregory Price, The Johns Hopkins Hospital.
• The following manufacturers who provided us with detailed
operating and maintenance information:
Joy Energy Systems, John Zink Company, Cleaver Brooks, and
Industronics.
• Mr. Charles Bollack and his staff, Mercy Medical Center, who
hosted the first trial run of this course and Mr. Robert J.
Winterbottom, R. J. Winterbottom, Inc., who assisted during the
course at Mercy Medical Center.
IV
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PREFACE
The program for development of a training course for ooerators of
hospital medical waste incinerators was funded as a project of EPA's
Control Technology Center (CTC) « « « project or tPA s
engineering assistance can be provided when appropriate Th rd fho rrr
^^FSSSXtt:'?^ «™ "g&ended ST"
-on training of the operator with the
The course consists of three volumes:
Volume I—Student Handbook
Volume II Course—Presentation Slides
Volume Ill—Instructor Handbook
This volume is a student handbook which includes 11 seoarat?
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TABLE OF CONTENTS
INTRODUCTION
SESSION 1. PROTECTING THE ENVIRONMENT - YOUR RESPONSIBILITY 1-1
SESSION 2. BASIC COMBUSTION PRINCIPLES 2-1
SESSION 3. BASIC INCINERATOR DESIGN 3_1
SESSION 4. AIR POLLUTION CONTROL EQUIPMENT DESIGN AND FUNCTIONS 4-1
SESSION 5. MONITORING AND AUTOMATIC CONTROL SYSTEMS 5_1
SESSION 6. INCINERATOR OPERATION 6-1
SESSION 7. AIR POLLUTION CONTROL SYSTEMS OPERATION 7-1
SESSION 8. MAINTENANCE INSPECTION--A NECESSARY PART OF YOUR JOB 8-1
SESSION 9. TYPICAL PROBLEMS g_l
SESSION 10. STATE REGULATIONS 10_1
SESSION 11. SAFETY: AN IMPORTANT PART OF YOUR JOB 11-1
GLOSSARY
SUGGESTED FURTHER READING
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SESSION 1.
PROTECTING THE ENVIRONMENT - YOUR RESPONSIBILITY
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SESSION.1. PROTECTING THE ENVIRONMENT - YOUR RESPONSIBILITY
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 1_1
WHY INCINERATION 1_1
ENVIRONMENTAL CONCERNS 1.2
Pathogen Destruction 1_2
Air Pollutants of Concern , i_2
Solid Waste Ash Quality 1_4
THE OPERATOR - YOUR ROLE 1_5
REFERENCES FOR SESSION 1 1_7
LIST OF FIGURE
Page
Figure 1-1. Schematic of incinerator showing sources of
pollutants of concern 1-3
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INTRODUCTION
DESCRIPTION
This course is designed for hospital waste incinerator operators. It
focuses on the basic principles of combustion; the proper design,
operation, and maintenance of hospital waste incineration systems and
their associated air pollution control systems; and the operator's role in
reducing air pollution and complying with applicable regulations.
COURSE GOALS AND OBJECTIVES
COURSE GOALS
1. To provide you with the knowledge of the basic principles of
incineration and proper operation and maintenance practices for hospital
waste incinerators and air pollution control systems.
2. To help you understand your role in protecting the environment by
reducing air pollution and disposing of ash properly.
3. To increase your awareness of regulatory requirements and safety
concerns.
COURSE OBJECTIVES
At the conclusion of this course you will:
1. Understand the air pollution problems associated with hospital
waste incinerators and how to minimize them.
2. Be aware of common operational problems and safety hazards and
their causes.
3. Know how to use monitoring and recordkeeping to improve operation
and maintenance and to aid in compliance with regulatory requirements.
US THE HANDBOOK
The material in the har covers the same topics your instructor
will cover. Your handbook ,- your use not only during the course but
also afterwords as a valuable reference when you go back to work.
There are one or more review exercises in each session. To complete
an exercise, place a piece of paper across the page, covering the
questions below the one you are answering. After writing your answer on a
separate piece of paper (not in the book),.slide the paper down to uncover
the next question. The answer for the first question will be given on the
right side of the page, separated by a line from the second question, as
shown on the next page. All answers to review questions will appear below
and to the right of their respective questions. The answer will be
numbered to match the question. Complete each review exercise in the
book. If you are unsure about a question or answer, review the material
in the session.
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A list of references used during preparation of the course is
provided at the end of each session. A list of documents which may be
particularly helpful to students wishing to learn more about particular
topics is presented at the end of the handbook.
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SESSION 1.
PROTECTING THE ENVIRONMENT - YOUR RESPONSIBILITY
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with
• Why hospital waste is incinerated;
• What the environmental concerns are related to incineration; and
• What air pollutants are important.
OBJECTIVES
Upon completing this session, you should be able to:
1. Name the primary reasons that hospital wastes are incinerated;
2. Identify environmental concerns related to incineration;
3. List the types of air pollutants of concern that could be emitted
to the atmosphere from hospital waste incinerators; and
4. Recognize your role in preventing air pollution and improper ash
disposal.
WHY INCINERATION
Hospitals generate large quantities of waste. Some of the types of
wastes that are generated are infectious wastes, spent alcohols or other
solvent materials, plastic containers, and general rubbish. Historically,
much of this waste has been disposed of in landfills. However, as many
landfills reach capacity and people become more concerned with environ-
mental problems caused by improper disposal of waste materials,
incineration has become an attractive option for handling wastes.
Incineration does not eliminate the need to landfill waste, but it does
reduce the amount of waste that must be placed in landfills. It also
generates a waste for landfills that is more acceptable than recognizable
hospital wastes to the general public.
The primary advantages of incineration are:
• It greatly reduces the weight and volume of waste material that
must be disposed of in landfills.
• It destroys organic materials that may be harmful or that may be
degradable to harmful materials in landfills.
• The incinerator sterilizes the waste. That is, the high
temperatures in incinerators can destroy any pathogens that may be
in infectious waste materials.
• The incinerator destroys animal or human pathological wastes or
other hospital waste materials that the general public finds
objectionable to handle or see.
1-1
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ENVIRONMENTAL CONCERNS
The general public will not accept incineration as an option for
treating hospital wastes if they do not believe that it is safe environ-
mentally. The primary concerns are that the pathogens are destroyed in
the incinerator, that the ash residue is of acceptable quality, and that
harmful air pollutants are not emitted from the incinerator. This section
will present some of the terminology that is important to understanding
these concerns. The remainder of the course will describe how an
incineration system can be operated and maintained in a way that keeps
environmental releases at an acceptable level.
PATHOGEN DESTRUCTION
The primary objective of hospital waste incineration is the
destruction of pathogens in infectious wastes. Pathogens are those
biological components of the waste that can cause an infectious disease.
The pathogens in infectious waste can be destroyed by the high
temperatures achieved in hospital waste incinerators. Almost no
information is available on the incinerator conditions required to destroy
all pathogens, but temperature and time of exposure are known to be
important. Emissions of pathogens from the incinerator could be
attributed to insufficient retention time and temperature as a result of
the following conditions:
1. Initial charging of the incinerator before operating temperatures
are achieved;
2. Failure to preheat the refractory lining;
3. Temperature fluctuations caused by intermittent use;
4. Exceeding design airflow rates, thereby reducing the retention
time;
5. Charging beyond incinerator capacity; and
6. Excessive moisture content of the waste.
Other factors such as the type of refractory lining, the positioning
and number of burners, and the precision of temperature controlling
devices also can affect pathogen destruction. The destruction of
pathogens in the incinerator ash also depends on temperature and time of
exposure.
AIR POLLUTANTS OF CONCERN
Figure 1-1 shows an incinerator and the main pollutants of concern.
These pollutants are:
Particulate matter;
Hydrochloric acid gas;
Toxic metals;
Organic compounds; and
Carbon monoxide.
1-2
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Organic
Compounds
Pathogens
Paniculate Carbon
• Monoxide
Toxic
Metals
'Hydrochloric Acid
Gas
Waste Feed
(May contain pathogens)
Fugitive
Paniculate
(windblown ash)
Ash
(May contain pathogens)
Figure 1-1.
Schematic of incinerator showing sources
of pollutants of concern.
1-3
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Particulate matter may be defined as fine liquid or solid matter such
as dust, smoke, mist, or fumes found in the gaseous emissions from the
incinerator. Particulate matter emissions may have a dark or light
color. Particulate matter emissions can be described in terms of
opacity. Opacity is the degree to which light is obscured by a polluted
gas—a clear window has 0 percent opacity while black paper has
100 percent opacity. Opacity may be measured with the naked eye or using
a transmissometer (opacity monitor). Particulate matter is a problem
because it can cause or aggravate respiratory problems in humans. It also
creates aesthetic problems since it is readily noticed and is a nuisance
because of soiling of exposed surfaces on houses and cars.
Hydrochloric (HC1) acid is generated when polyvinyl chloride (PVC)
plastic (usually clear plastic) material is burned in the incinerator.
The appearance of a white plume or cloud a short distance above the stack
indicates that HC1 is condensing. The major concerns about HC1 are that
it causes respiratory problems in humans, contributes to acid rain
problems, and causes material damage to metals and concrete..
Toxic metals include cadmium, arsenic, beryllium, chromium, nickel,
lead, and mercury. These metals may be found in hospital wastes. These
metals are known to be hazardous to human health.
Organic compounds are compounds that contain primarily carbon and
hydrogen and may also contain other elements such as oxygen, nitrogen, and
chlorine in smaller amounts. Some organic compounds are known to cause or
are suspected of causing cancer and are considered hazardous air
pollutants. The public's primary concern is related to dioxin and furan
emissions, but other organic compounds such as benzene and vinyl chloride
may be emitted.
Carbon Monoxide (CO) also is generated during combustion if the
combustor is not operated properly. (Your automobile generates some
amount of CO.) CO is toxic to humans if concentrations are high enough,
and it also is an indicator of combustion quality.
SOLID WASTE ASH QUALITY
One of the major objectives of incineration is to generate a high
quality ash for land disposal. All pathogens should be destroyed, and
almost all organic material should be completely burned. Ideally, no
large chunks of unburned waste material (other than metals or glass)
should remain in the waste. Attempting to dispose of hospital waste that
is incompletely burned may result in monetary fines, or the landfill may
refuse to accept the waste. From an aesthetic standpoint, large pieces of
medical waste that have not been burned may be of concern to the public.
A measure of ash quality is "burnout," which is the percentage of organic
material remaining in the waste. For example, a burnout of 95 percent
means that the ash can contain only 5 percent organics.
Adequately burned and quenched ash may be disposed of in a sanitary
(municipal) landfill. The ash should be stored in covered containers or
1-4
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SESSION 2. BASIC COMBUSTION PRINCIPLES
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES
2-1
THE COMBUSTION REACTION....
2-1
OPERATING FACTORS RELATED TO COMBUSTION
PRODUCTS OF THE COMBUSTION REACTION 2
COMBUSTION INDICATORS
2-7
REFERENCES FOR SESSION 2..
2-10
LIST OF FIGURE
Page
Figure 2-1. Relationship of temperature to excess air 2.5
LIST OF TABLE
Page
TABLE 2-1. CHARACTERIZATION OF HOSPITAL WASTE.
••••••••............ 2-6
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SESSION 2.
BASIC COMBUSTION PRINCIPLES
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kept wet prior to transport to the landfill to prevent fuaitivp
enS Ir*iv1*jal landf"1s may have requirements thlt must be
g
THE OPERATOR - YOUR ROLE
dnd resP°"^1l1ty fc° Protect the
specified
n* Ml n]mi Z1 ngemi ssions of particulate matter, HCI, toxic metals
through ™
4. Minimizing particulate matter emissions from ash
sites;*and P°Slng °' "h Pr°PeHy by Sendfn^ ft to •PPro
^nc -6' 0Pe[form1ng the regular maintenance inspections (described in
Session 8) to catch any operational problems early. tdescril*d in
you Jet' [h^s Es^bt Wil1 Pr°Vlde YOU WUh info^tio" to help
1-5
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REVIEW EXERCISE
1. List three advantages of hospital waste
incineration
2. List the main pollutants of concern.
3. Emissions of hydrochloric acid gas occur
because of the presence of in
the feed material.
4. Waste ash that does not meet landfill
requirements can be refused by the
landfill, and monetary fines may be
imposed for improper ash disposal. True
or false.
5. To minimize environmental problems, you
should properly:
a)
and
b)
6. You should perform regular
inspections to catch any problems early.
1. Reduces volume
and weight of waste
Destroys pathogens
(sterilizes waste)
Destroys organics
Destroys objectional
waste materials
2. Particulate matter
Hydrochloric acid
gas
Toxic metals
Hazardous organics
Carbon monoxide
3. Polyvinyl chloride
plastic
4. True
5. a)operate your
incinerator
b)handle and
dispose of the
ash.
6. Maintenance
1-6
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REFERENCES FOR SESSION 1
1. U. S. Environmental Protection Agency. EPA Guide for Infectious
Waste Management. EPA/530-SW-86-014. (NTIS PB 86-199 130) U S
EPA Office of Solid Waste. May 1986. w^u). u. 5.
2. Ontario Ministry of the Environment. Incinerator Design and
3. Barbeito, MS. and M. Shapiro. Microbiological Safety Evaluation
°n
* Ld;-EnDlSTJ?Jal-Pr0SCt1onA2ency- Hosp1tal Waste Combustion
Study. Data Gathering Phase. EPA 450/3-88-017. December 1988
1-7
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SESSION 2,
BASIC COMBUSTION PRINCIPLES
GOAL AND OBJECTIVES
GOAL
To familiarize you with:
" tBhaeSlcouC?se;Sti°n term1n°logy that wil1 be u^ed in the remainder of
• How the combustion process works and how you affect the
• Indicators of good combustion and poor combustion" and
• How the combustion process affects air emissions
OBJECTIVES
Upon completing this session, you should be able to:
t0° much or to°
?' Ite^Sf hhe Sdtins value of d1ffere"t waste types;
combusiloS *r? "OW the c°n*ustf°" 9" oxygen ,evel fs re,ated to
enS t0 °>K^ -tr poor
9. Recognize the definitions of these terms:
• Heating value;
• Stoichiometric (theoretical) air-
• Excess air;
• Starved air; and
• Products of incomplete combustion.
THE COMBUSTION REACTION
isrv
Organic M,ter1a, + Oxygen— __. Co*.,st1on Gas * SoHd Residue + EnerjyfHeat)
2-1
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For the reaction to begin and to keep going, all three elements—organic
material, oxygen, and heat—must be present.
The organic material used in the reaction comes from two sources,
waste and auxiliary fuel. Some organic material is contained in most*
hospital waste. Depending on the fraction of organics and the specific
organic composition, the waste may be adequate to sustain combustion. The
other source of organic material is auxiliary fuel. Auxiliary fuel is
always used to preheat the incinerator and to start combustion; auxiliary
fuel may be used to maintain combustion if the waste material does not
contain enough organic material to maintain high temperatures.
The oxygen needed for the combustion reaction is supplied by the
ambient combustion air. Combustion air is supplied to the combustion
chambers through air ports by a forced draft fan, by an induced draft fan,
or by natural draft. In general, this air contains about 2] percent
oxygen (02) and 79 percent nitrogen (N2), so about 21 percent of the total
combustion air fed to the incinerator is oxygen that is available to react
with the organic material in the waste and fuel.
The combustion reaction between the organic material and oxygen that
causes the organics to burn will occur only after the temperature of the
organic material is raised to the point that combustion can begin. Each
specific organic compound has its own temperature at which the reaction
occurs, but temperatures in the range of 1000° to 1800°F generally are
considered to provide "good combustion conditions." Energy in the form of
heat is required to raise the temperatures of the incinerator chamber and
organic material and 02. Initially, this energy usually is supplied by
the pilot and auxiliary fuel burners. After the system is in full
operation, the energy released from the burning waste often is adequate to
maintain these high temperatures.
Hospital wastes contain two types of organic materials—volatile
matter and fixed carbon. These two types of materials are involved in
distinct types of combustion reactions, and the operating variables that
control the two types of reaction are different.
Volatile matter is that portion of the waste that is vaporized (or
evaporated) when the waste is heated. Combustion occurs after the
material becomes a gas. The combustion variables that influence this
reaction are gas temperature, residence time, and mixing. A minimum
temperature is needed to start and sustain the chemical reaction.
Residence time is the length of time, generally measured in seconds, that
the combustion gas spends in the high temperature combustion chamber. The
residence time must be long enough for the reaction to be completed before
it leaves the high temperature zone. Turbulent mixing of the volatile
matter and combustion air is required to ensure that the organic material
and oxygen are well mixed.
Fixed carbon is the nonvolatile organic portion of the waste. For
fixed carbon, the combustion reaction is a solid-phase reaction that
occurs primarily in the waste bed (although some materials may burn in
2-2
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suspension). Key operating parameters are bed temperature solids
retention time, and mechanical turbulence in the bed. The'sol ds
retention time is the length of time that the waste bed rLflhTTn the
Mechanical turbulent Of the bed is needed to expos! all
he C0mplete burn°ut' Wfthout *"
a
OPERATING FACTORS RELATED TO COMBUSTION
The three operating factors that have the greatest effects on
combustion reaction are combustion air flow rat! and dUribut on
The two key questions about combustion air that we will address are:
* reactioU?COmbUSti0n *1r iS needed t0 SUStain the Combustion
• What happens if there is too much or too little combustion air?
COMBUSTION AIR
In the chemical reaction between organic materials and
amount of oxygen required under ideal or-perfect" cSndltS
of the organic materials with no oxygen left over is
i«'s
all
«, ..
Computation of exact stoichiometric air requirements for a
U is ^asured in
e
r , A s ^T^a'r: s
stoichiometric point, the temperature in the incinerator droos
STS r ;s£ artsyss*- % ^^S
2-3
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temperature," .and undesirable combustion products are generated as a
result of incomplete combustion. As the amount of excess air is
decreased, the combustion temperature increases until it becomes maximum
at the stoichiometric point. Below the stoichiometric point, the
temperature decreases because complete combustion has not occurred. A
graphical representation of the relationship between combustion
temperature and excess air level is shown in Figure 2-1. At air levels
below the stoichiometric point, some of the organics are not reacted, and
pollutants are emitted as a result of incomplete combustion..
If an incinerator operates with excess air, some of the oxygen in the
combustion air does not react. Increases in excess air levels result in
increases in combustion gas oxygen levels. The oxygen concentration of
the effluent gas stream is a useful indicator of the combustion excess air
levels and is useful for monitoring the combustion process.
COMBUSTION TEMPERATURE
Temperature also plays an important role in the combustion of
hospital wastes. Temperatures should be maintained at levels above design
temperatures to ensure pathogen destruction and to sustain the combustion
reaction. However, temperatures that are too high also cause problems.
Continuous exposure of the combustor refractory to high temperatures is
generally not desirable because it can cause the ash to fuse and can cause
thermal damage to the refractory. The lower and upper limits for "proper"
temperature ranges are discussed in later sessions of this course.
WASTE CHARACTERISTICS
The primary characteristics of the waste that affect the combustion
reaction are the heating value, the moisture content, and the chlorine
content. Typical heating values and moisture contents of some waste
materials typically fired to hospital waste incinerators are shown in
Table 2-1.
The heating value of a waste is a measure of the energy released when
the waste is burned. It is measured in units of Btu/lb (J/kg). A heating
value of about 5,000 Btu/lb (11.6x10 J/kg) or greater is needed to
sustain combustion. Wastes with lower heating values can be burned, but
they will not maintain adequate temperature without the addition of
auxiliary fuel. The heating value of the waste also is needed to
calculate total heat input to the incinerator where:
Heat Input (Btu/h) = Feed Rate (Ib/h) x Heating Value (Btu/lb)
Moisture is evaporated from the waste as the temperature of the waste
is raised in the combustion chamber; it passes through the incinerator,
unchanged, as water vapor. This evaporation of moisture uses energy and
reduces the temperature in the combustion chamber. The water vapor also
increases the combustion gas flow rate, which reduces combustion gas
residence time.
2-4
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TEMPERATURE
MAXIMUM
TEMPERATURE
DEFICIENT AIR j EXCESS AIR
PERCENT EXCESS AIR
CONTROL OF TEMPERATURE AS A FUNCTION OF EXCESS AIR
Figure 2-1. Relationship of temperature to excess air.
2-5
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TABLE 2-1. CHARACTERIZATION OF HOSPITAL WASTED
Component description
Human anatomical
Plastics
Swabs, absorbants
Alcohol, disinfectants
Animal infected anatomical
Glass
Beddings, shavings, paper,
fecal matter
Gauze, pads, swabs, gar-
ments, paper, cellulose
Plastics, PVC, syringes
Sharps, needles
Fluids, residuals
HHV
dry basts,
kJ/kg
18,600-27,900
32,500-46,500
18,600-27,900
25,500-32,500
20,900-37,100
0
18,600-20,900
18,600-27,900
22,500-46,500
140
0-23,200
Bulk
density as_
f i red , kg/nr
800-1 ,200
80-2,300
80-1,000
800-1 ,000
500-1,300
2,800-3,600
320-730
80-1 ,000
80-2,300
7,200-8,000
990-1,010
Moisture
content of
component,
weight %
70-90
0-1
0-30
0-0.2
60-90
0
10-50
0-30
0-1
0-1
80-100
Heat
value as
fired, kJ/g
1,860-8,370
32,300-46,500
13,000-27,900
25,500-32,500
2,090-14,900
0
9,300-18,800
13,000-27,900
22,300-46,500
140
0-4,640
Component description
Human anatomical
P 1 ast i cs
Swabs, absorbants
Alcohol, disinfectants
Animal infected anatomical
Glass
Beddings, shavings, paper,
f eca 1 matter
Gauze, pads, swabs, gai —
meats, paper, cellulose
Plastics, PVC, syringes
Sharps, needles
Fluids, residuals
HHV
dry basis,
Btu/lb
8,000-12,000
14,000-20,000
8,000-12,000
11,000-14,000
9,000-16,000
0
8,000-9,000
8,000-12,000
9,700-20,000
60
0-10,000
Bulk
dens i ty
as fired,
Ib/ft-5
50-75
5-144
5-62
48-62
30-80
175-225
20-45
5-62
5-144
450-500
62-63
Moisture
content of
component,
weight 2
70-90
0-1
0-30
0-0.2
60-90
0
10-50
0-30
0-1
0-1
80-100
Heat value
as fired,
Btu/lb
800-3,600
13,900-20,000
5,600-12,000
11,000-14,000
900-6,400
0
4,000-8,100
5,600-12,000
9,600-20,000
60
0-2,000
2-6
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Most chlorine in plastics or solvents in the waste feed will react to
form hydrochloric acid (HC1). This HC1 is an emission problem and U can
create corrosion problems downstream from the incinerator
PRODUCTS OF THE COMBUSTION REACTION
Pr;jmary. Products of hospital waste incineration are combustion
f,,.i The Or?an19,mater1als that enter the incinerator with the waste and
fuel are primarily .ade up of carbon, hydrogen, and oxygen Ideally
0ran'Cmrl "1th ox?gen '" **• combu«ion g fto form
'
s
Organics + 02 * C02 + H20 + Heat
(C, H, 0)
This ideal reaction represents complete combustion.
ThTSSi f J°? 6XCeSS air Condit1ons. is elemental carbon (or soot?
The waste feed also includes inorganic materials General! v thaw
a^^^
the comb^tion gas. Air veloci^es in the
COMBUSTION INDICATORS
fniinl?6 ^^r^ion presented in the above section suggests that the
following indicators can be used to monitor combustionquality
2-7
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OPACITY
The opacity of the combustion gas stream is a measure of the deqree
to which the stack gas plume blocks light. Opacity is primarily caused by
noncombustible ash or uncombusted carbon (soot) in the flue gas. High
opacities can indicate poor mixing or low levels of combustion air Hiqh
opacities also may be generated by high levels of HC1 emissions or poor
burner operation in the secondary chamber. If a large amount of water
vapor is present in the combustion gas, the water can condense when it
cools as it leaves the stack forming a dense white "steam plume." This is
not an indicator of poor combustion and should not be confused with a
black or white smoke plume caused by soot or acid gases.
STACK GAS 0, CONCENTRATION
The stack gas 02 concentration provides a measure of excess air
Hospital waste incinerators typically operate at 140 to 200 percent excess
air, which roughly corresponds to 12 to 14 percent 02 in the stack gas.
STACK GAS CO CONCENTRATION
Each combustion system has a "typical operating range" for CO. If
the stack gas CO concentration goes above this typical range, combustion
problems are likely.
COMBUSTION TEMPERATURE
Rapid increases or decreases in combustion gas temperature indicate
potential combustion problems. Rising temperatures indicate that the heat
input is increasing and/or airflow is decreasing which can lead to
insufficient air for complete combustion. Falling temperatures indicate
problems in sustaining combustion.
ASH COMBUSTIBLES
If an incinerator is operating properly, little organic material will
remain in the ash. The extent of organics combustion is measured by the
quantity of combustible materials remaining in the ash. Increases in ash
combustibles indicate that bed temperatures are too low, that combustion
air is not being distributed properly in the bed, or that waste retention
time is too short.
2-8
-------
REVIEW EXERCISE
•-'
1. List the three factors required for
combustion.
2.
3.
Which of the following are products of
complete combustion?
Dioxins
H20
CO
C02
The heating value of a waste required to
sustain combustion without auxiliary
fuel is about Btu/lb.
4. List two combustion conditions that can
cause high stack gas CO concentrations.
5. When the combustion air level is below
stoichiometric, it is called a
substoichiometric or _ai>
condition. ~~
6. All inorganic material is removed with
the ash. True or False?
7. As excess air levels increase beyond
stoichiometric levels, temperatures
8. About 1 scf of combustion air is needed
for every Btu of heat input.
9. Heat input (Btu/h) =
heating value (Btu/lb) x .
10. Describe the combustion conditions that
result in high opacity.
11. The most common product of incomplete
combustion is
1. Organic material
Oxygen
Heat
2. H20
CO 2
3. 5,000
4. Poor mixing
Low temperature
Insufficient air
starved
6. False. Some may be
emitted as particu-
late matter in the
combustion gases.
7. decrease
8. 100
9. feed rate, Ib/h
10. Poor mixing or low
excess air which
causes soot
formation.
11. CO
2-9
-------
REFERENCES FOR SESSION 2
1. McRee, R. Operation and Maintenance of Controlled Air Incinerators.
Ecolaire Environmental Control Products. Undated.
2. U. S. Environmental Protection Agency. EPA Guide for Infectious Waste
Management. EPA/530-SW-86-014. (NTIS PB 86-199130). U. S. EPA
Office of Solid Waste. May 1986.
3. Ontario Ministry of the Environment. Incinerator Design and Operating
Criteria, Volume II-Biomedical Waste Incineration. October 1986.
4. Beard, J. T., F. A. lachetta, and L. V. Lillelehet. APTI Course 427,
Combustion Evaluation, Student Manual. EPA 450/2-80-063. U. S. EPA
Air Pollution Training Institute. February 1980.
5. Beachler, D. S. APTI Course SI:428A, Introduction to Boiler
Operation, Self Instructional Guidebook. EPA 450/2-84-010. U. S.
EPA. December 1984.
6. Brunner, C. R. Incineration Systems. Van Nostrand Reinhold. 1984.
7. U. S. Environmental Protection Agency. Municipal Waste Combustion
Study: Combustion Control. EPA 530-SW-87-021C. (NTIS PB 87-206090).
June 1987.
8. Air Pollution Control District of Los Angeles County. A1r Pollution
Engineering Manual, 2nd Edition AP-40. (NTIS PB 225132). U. S.
EPA. May 1973.
2-10
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SESSION 3,
BASIC INCINERATOR DESIGN
-------
SESSION 3. BASIC INCINERATOR DESIGN
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 31
INTRODUCTION ..".......... 2'-!
MAJOR PARTS OF AN INCINERATION SYSTEM ............. 3!].
MULTIPLE-CHAMBER INCINERATORS 3-3
Introduction *****"'*!' 3-3
Principle of Multiple Chamber "Excess-Air" Incineration.*.*.".*.*.".*.'.* 3^
Components of Multiple-Chamber Incinerators ' 3.4
CONTROLLED-AIR INCINERATION ''" 3.3
Principle of Controlled-Air Incineration 3-8
Components of a Controlled-Air Incinerator 3 12
ROTARY KILN ...'**''**'*" 3^4
Introduction .* *'*.".""***''* 3-14
Principle of Operation "*'*****"! 3^4
Components of a Rotary Kiln 3 ^4
MODE OF INCINERATOR OPERATION 3~-l6
Single Batch Operation '**!"*' 3-16
Intermittent Duty .'.'******'* 3-16
Continuous Duty 317
WASTE FEED CHARGING AND ASH HANDLING SYSTEMS .........'. 3-17
Waste Feed Charging System .*..' 3.17
Ash Removal Systems .**.'** 3-20
COMBUSTION GAS HANDLING SYSTEM "" 3.31
BURNERS 3-23
Forced Air Blower ..*..*.** 3-24
Fuel Train ....!'* 3-24
Pilot and Main Burners [[ 3.24
FTame Safeguard [[[. 3,24
WASTE HEAT BOILERS '. 3.25
REFERENCES FOR SESSION 3 .'*" 3_28
LIST OF FIGURES
Figure 3-1. Major components of an incineration system... 3-2
Figure 3-2. In-line multiple-chamber, excess-air incinerator 3-5
Figure 3-3. Retort multiple-chamber, excess-air incinerator 3-6
Figure 3-4. Principle of controlled-air incineration 3-9
Figure 3-5. Control of temperature as a function of excess air.. 3-11
Figure 3-6. Major components of a controlled-air incinerator 3-13
Figure 3-7. Rotary kiln with auger feed 3-15
Figure 3-8. Hopper/ram mechanical waste feed system 3-18
Figure 3-9. Hopper ram charging sequence 3-19
Figure 3-10. Incinerator with staged hearth and automatic ash
removal 3.22
Figure 3-11. Incinerator with waste heat boiler and bypass stack 3-26
-------
SESSION 3.
BASIC INCINERATOR DESIGN
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with
"^components of an incinerator system:
«nl I-"* types of itineration syTteii and
OBJECTIVES
Upon completing this session, you should be able to:
control*Ied1?r1ofr rolry'lt^™™^ y°U °P^te-multiple chamber,
O T _l-. _ j-.* *• . i , *
type ol
8 and
INTRODUCTION
During this session we will discuss:
1. The major components of an incineration system:
• Waste handling and charging system:
• Incinerator;
• Ash removal system;
• Auxiliary components; and
• Control /monitor ing system.
«*•*
Multiple chamber;
Control led-air; and
Rotary kiln.
MAJOR PARTS OF AN INCINERATION SYSTEM
a »» - -
3-1
-------
To
Atmosphere
Stack
To
Atmosphere
Stack
r Waste ,
1 Heat i
I Boiler '
Air
Pollution
Control
System
Ash
Figure 3-1. Major components of an incineration system.
3-2
-------
For example, let's consider the waste charging system:
s w
system with automatic controls and interlocks -
rate can be automatically controlled by
The operation of the waste charging system affects the
performance of the incinerator; if waste is fed to the
incinerator too fast, incomplete combustion £d .VJSnutlon may
The maintenance of the waste charging system
and SSr3'6 Tr 1"cl'"e'-«or, you should
operation and "'0" °' "Ch P*rt 4ffects
there
Multiple chamber;
Controlled air; and
Rotary kilns.
°r i"ci"«--«°" USed for
MULTIPLE-CHAMBER INCINERATORS
INTRODUCTION
chambers;thepHary chambrfo^.^^J °f tW° °r more combus^'°n
chamber for gas phase common ?h«a P " C0mjustion and the secondary
are used f0-- «'«Pl-ch«ber
3-3
-------
the "in-line" hearth, and
the "retort" hearth.
Figure 3-2 depicts the in-line hearth design. For the in-line hearth,
flow of the combustion gases is straight through the incinerator with
turns in the vertical direction only (as depicted by the arrows in
Figure 3-2). Figure 3-3 depicts the retort design. In the retort
incinerator, the combustion gases turn in the vertical direction (upward
and downward) as in the in-line incinerator, but also turn sideways as
they flow through the incinerator. Because the secondary chamber is
adjacent to the primary chamber (they share a wall) and the gases turn in
the shape of a U, the design of the incinerator is more compact. In-line
incinerators perform better in the capacity range greater than 750 Ib/h
(340 kg/h). The retort design performs more efficiently than the in-line
design in the capacity range of less than 750 Ib/h (340 kg/h). The retort
design is more typically used in hospital waste applications. Multiple-
chamber incinerators are frequently designed and used specifically for
incinerating pathological wastes.
PRINCIPLE OF MULTIPLE CHAMBER "EXCESS-AIR" INCINERATION
The combustion process involves two chambers. Both the primary and
secondary combustion chambers are operated above stoichiometric oxygen
levels.
• In the primary chamber, the waste is ignited using the primary
burner. Once the waste has started burning, the burner usually
shuts off because it is no longer needed.
• Moisture and the volatile part of the waste are vaporized.
• As the burning proceeds, combustion of the nonvolatile portion
(fixed carbon) of the waste occurs in the primary chamber. The
incinerator is designed for surface combustion of the waste.
Surface combustion requires mostly overfire combustion air, rather
than underfire air.
• The combustion products and vaporized gases pass from the primary
chamber through the flame port to the mixing chamber.
• Secondary combustion air is added in the flame port. The design
of the flame port and mixing chamber, as well as the addition of
secondary air, promotes mixing.
• A secondary burner located in the mixing chamber provides
additional heat to maintain sufficient combustion temperatures.
• The combustion of the gases begun in the mixing chamber continues
as the gases pass through a port in the wall to the secondary or
"combustion" chamber.
COHPONENTS OF MULTIPLE-CHAMBER INCINERATORS
The key components of a multiple-chamber retort incinerator are
identified in Figure 3-3.
Primary Chamber. The chamber where the waste is fed and combustion
begins. The chamber is operated in an "excess-air" atmosphere.
3-4
-------
Charging Door
with Overfire
Air Pott
Grates
•Cteanout Doors with-
Undergrate Air Port
Location of
Secondary
Burner
Mixing Chamber
Curtain
Wall Port
Figure 3-2. In-line multiple-chamber, excess-air incinerator.1
3-5
-------
Charging -v
Door \
Slack
Door
Ignition Chamber
Hearth
Seconaary
Air Ports
Seconaary
Burner Port
Mixing
Chamber
First
Underheann
Port
Secondary
Combustion
Chamber
Mixing Chamber
RamePort
Charging
Door
Hearth
Primary
Burner Port
Second
Underheann
Port
Figure 3-3. Retort multiple-chamber, excess-air incinerator.1
3-6
-------
Hearth. The hearth is the surface on which the waste is placed. The
hearth on a multiple-chamber incinerator is either a metal grate
(Figure 3-3) or solid refractory hearth. When a grate is used, ash falls
through the grate into the ash pit. Note: A grate will allow liquids and
small solid objects (such as needles) to fall through to the ash pit;
consequently, multiple-chamber incinerators designed with a grate hearth
are not recommended for burning infectious wastes. Incinerators designed
specifically for burning pathological wastes such as body parts and
animals, i.e., "pathological incinerators," are always designed with solid
hearths.
Ignition Burner. Fuel burner for igniting the waste.
Charging Door. Door through which waste is loaded.
Overfire Air Port. Adjustable natural draft opening which allows
overfire combustion air to enter the primary chamber. A forced draft
combustion air blower also may be used to provide overfire air.
Cleanout Door(s). Door(s) for removal of ash from the primary and
secondary chambers.
Mixing Chamber. Chamber located between the primary and secondary
combustion chamber in which the combustion gases and secondary combustion
air are mixed and burning is initiated.
Flame Port. Opening between the primary chamber and mixing chamber
through which the combustion gases pass.
Secondary Air Port. Natural draft opening through which the
secondary combustion air enters the mixing chamber. A forced air blower
also may be used to provide, combustion air to the secondary chamber.
Secondary Burner. Auxiliary fuel burner for maintaining high gas
temperature sufficient for complete combustion.
Secondary Combustion Chamber. Chamber where combustion of qases is
completed.
Stack. Duct for venting combustion gases to atmosphere.
Multiple-chamber incinerators designed specifically for pathological
wastes incorporate the following two design features:
1. The hearth in the primary chamber is solid instead of a qrate'
and 3 '
2. The auxiliary burners in the primary chamber are intended for
continuous operation.
Pathological waste is moist and contains liquids. To assure that
fluids are retained in the incineration chamber, a solid hearth is used
A raised "lip" at the door often is designed into the hearth to prevent'
liquids from spilling out the door during charging. Because the heating
3-7
-------
value of pathological waste is low and is not sufficient to sustain
combustion, additional auxiliary burners are provided in the primary
chamber to provide the heat necessary for incineration.
CONTROLLED-AIR INCINERATION
The terms used to describe various types of incinerators are quite
varied. Multiple names have been used to describe the same type of
incinerator. We will use the term "controlled-air" incinerator to
describe one particular type of incinerator. In a controlled-air
incinerator the amount and distribution of air to each combustion chamber
is controlled. This type incinerator is often referred to as a "starved-
air" incinerator. The term "starved-air" is derived from the principle of
combustion most frequently used in this type of incinerator. The
combustion air to the chamber into which the waste is fed is strictly
controlled so that the amount of air present is less than that needed for
complete combustion, i.e., the chamber is "starved" for air.
Controlled-air incinerators come in all sizes and shapes.
Incinerators are available with design capacities ranging from 50 Ib/h
(23 kg/h) to 4,000 Ib/h (1,800 kg/h). Some are manually controlled, and
others are automatically controlled. Some use manual waste loading and
ash removal, and others are fully automated.
This section presents the operating principle of controlled-air
incineration and identifies the major components of a controlled-air
incinerator.
PRINCIPLE OF CONTROLLED-AIR INCINERATION
Figure 3-4 is a simplified drawing of an incinerator that operates
using the controlled-air principle. The principle of controlled-air
combustion is summarized as follows:
• The system consists of two combustion chambers:
— the primary chamber (also referred to as the ignition
chamber); and
— the secondary chamber (also referred to as the combustion
chamber).
• The primary chamber accepts the waste, and the combustion process
begins. A burner is used to ignite the waste. Once the waste has
started burning, the burner usually shuts off because it is no
longer needed (unless pathological wastes are being incinerated).
• The air distributed to the primary chamber is controlled so that
the chamber is starved for oxygen, in other words, the chamber is
operated below stoichiometric levels.
• The combustion air usually is fed to the primary chamber as
underfire air—underfire air is directed "under" or through the
waste bed through air inlets located near the floor or hearth of
the primary chamber.
3-8
-------
AUXILARY
IGNITION
BURNER
COMBUSTION GASES
SECONDARY CHAMBER
Volatile Content is Burned
Under Excess Air Conditions
PRIMARY CHAMBER
(Starved Air Condition)
Volatiles and Moisture
MAIN BURNER
FOR MAINTAINING
MINIMUM COMBUSTION
TEMPERATURE
MAIN FLAMEPORT AIR
ASH AND
NON-COMBUSTIBLES
CONTROLLED UNDERFIRE
AIR FOR BURNING
"FIXED CARBON"
Figure 3-4. Principle of control led-
air incineration.
3-9
-------
• Three processes occur in the primary chamber.
— First - the moisture in the waste is vaporized; boiling a pot
of water on the stove is an example of the vaporization of
water.
— Second - the volatile fraction of the waste is vaporized; when
an open can of gasoline sits in the sun, the gasoline
vaporizes.
— Third - the fixed carbon remaining in the waste is burned.
Fixed carbon is the nonvolatile portion of the waste. To
achieve complete combustion, the fixed carbon must be burned
in the primary chamber at higher temperatures and for longer
times then the volatile fraction. Charcoal briquettes burning
in your charcoal grill are an example of fixed carbon
burning.
• The combustion gases containing the moisture and the volatile
combustible materials from the primary chamber are directed to the
secondary chamber.
• As the gases enter the secondary combustion chamber more air—the
secondary combustion air—is added. The air is added with enough
force to cause mixing of the air and the combustion gases.
• Enough air is added to the secondary chamber so that an "excess"
of oxygen is available for the combustion process.
• The gas/air mixture is burned in the secondary chamber at high
temperatures 1800° to 2200°F (980° to 1200°C) to promote complete
combustion.
• A fuel burner is used in the secondary chamber to ensure that the
high temperature is maintained.
Control of the Incinerator. The amount of air supplied to each
chamber of the incinerator is used to control the combustion chamber
temperature. Figure 3-5 illustrates this principle.
• The primary chamber operates in a starved-air condition. Adding
more air allows more combustion and therefore increases the
temperature (up to the point of maximum temperature at the
stoichiometric air level).
• The secondary chamber operates in an excess-air condition. Adding
more excess air (which is cold) dilutes and cools the gases and
decreases the temperature.
Thus:
The amount of air supplied to the primary chamber controls the
combustion rate of the waste and the temperature of this chamber;
and
The amount of air supplied to the secondary chamber controls the
temperature of this chamber and the combustion rate of the
combustion gases from the primary chamber.
3-10
-------
CHAMBER OPERATING
RANGE
TEMPERATURE
DEFICIENT AIR
-*• SECONDARY
CHAMBER OPERATING
EXCESS AIR
PERCENT EXCESS AIR
Figure 3-5. Control of temperature as a function of excess air.
3-11
-------
The control system for a controlled-air incinerator is based upon the air
levels and temperatures in each chamber. Control systems are discussed in
Session 5.
COMPONENTS OF A CONTROLLED-AIR INCINERATOR
Figure 3-6 presents a schematic of a controlled-air incinerator. The
major components identified are:
1. Primary Chamber. The chamber where the waste is fed and
combustion begins. The primary chamber operates with a "starved-air"
atmosphere.
2- Primary Chamber - Combustion Air Blower. Forced air blower for
providing underfire combustion air to the primary chamber.
3. Primary (Ignition) Burner. Fuel burner for preheating
combustion chamber, igniting waste, and maintaining temperature in the
primary chamber.
4. Charge Door. Door through which waste is loaded.
5. Ash Removal Door. Door through which ash is removed from the
primary chamber.
6« Secondary Combustion Chamber. Chamber where combustion of
volatile gases is completed. The secondary chamber operates with an
excess-air atmosphere.
7. Secondary Combustion Air Blower. Forced air blower for
providing combustion air to the secondary chamber.
8. Secondary Combustion Chamber Air Port. Port through which
combustion air enters chamber and causes mixing.
9. Secondary Combustion Chamber Burner. Auxiliary fuel burner for
maintaining high temperature in secondary chamber.
10. Cleanout/Inspection Doors. Doors in the secondary and primary
chambers which can be opened when the incinerator is shut down to remove
ash and inspect the refractory.
11 • Primary Chamber Water Spray. Some manufacturers include a spray
system to inject a fine water spray (mist) into the primary chamber to
assist in temperature control.
12. Primary Chamber Underfire Steam Injection. Some manufacturers
include systems for injecting steam into the ash.
13. Stack. Natural draft stack for venting combustion gases to the
atmosphere. Because gases are hot, they rise up the stack causing a
"draft" (pulling air) through the system.
14. Thermocouples. Two thermocouples located at the exit to each
chamber to measure the temperature of the combustion gases.
15. View Ports. Sealed glass view ports for observing the
combustion chamber during operation.
16. Control Panel. Instrument panel where the controls and the
instruments for controlling and monitoring the operation are located.
The incinerator, as shown in Figure 3-6, has a hopper/ram assembly
for automatically feeding the waste to the incinerator but no mechanical
device for continuously removing the ash from the system. Waste feed charging
systems and ash removal systems are discussed later in this section.
3-12
-------
Control Panel
t
. Stack
Secondary Combustion
Air Blower
Mechanical
Charge System
Secondary Chamber
Primary.
Burner
Primary Combustion
Air Burner Blower
Viewport
Secondary Burner
Viewport
Ash Removal
Door
Primary Chamber
Figure 3-6. Major components of a controlled-air incinerator.
3-13
-------
ROTARY KILN
INTRODUCTION
Figure 3-7 is a schematic of a rotary kiln. A rotary kiln also uses
the concept of two stage combustion and has two combustion chambers. The
primary chamber is a horizontal cylindrical chamber which is slightly
inclined and rotates, hence the name "rotary kiln." The secondary chamber
is usually cylindrical in shape—much like the secondary chambers
described for controlled-air incinerators—or is box-like as depicted in
Figure 3-7.
PRINCIPLE OF OPERATION
A rotary kiln is designed to operate continuously. The incinerator
must include a system for continuous waste feed to the kiln and continuous
ash removal. The principle of operation of a kiln is summarized as
follows:
• The rotating kiln is inclined, waste is fed into the higher end
of the kiln by the mechanical feed system.
• Inside the kiln, moisture and volatiles are vaporized from the
waste, and the waste is ignited. The volatile gases pass into the
secondary chamber.
• Air and heat are added in the secondary chamber to promote
complete combustion.
• As the kiln rotates, the solids are tumbled within the kiln and
slowly move down the incline toward the discharge end. Tumbling
of the waste within the kiln provides exposure of the waste to the
air. Combustion of the solids occurs within the kiln, and the ash
is discharged into the ash removal system.
• The residence time of the solids within the kiln can be controlled
by the kiln's speed of rotation (revolutions per minute [rpm]).
The faster the kiln rotates, the faster the solids will move
through, the kiln.
COMPONENTS OF A ROTARY KILN
The key parts of a rotary kiln are shown in Figure 3-7:
Charging System. Mechanical waste feed charging system for
continuously feeding waste to the kiln.
Kiln. The rotating kiln is the primary combustion chamber. The
waste is fed into this kiln and ignited. Traditionally, the kiln operates
with an excess-air atmosphere. However, some manufacturers now have
rotary kilns designed to operate with a substoichiometric atmosphere in
the kiln; these kilns use special seals and air injection schemes.
3-14
-------
To
Atmosphere
Stack
Figure 3-7. Rotary kiln with auger feed.
3-15
-------
Kiln Drive. The kiln is rotated by a drive motor and gear system.
Primary Burner. The primary burner ignites the waste and provides
additional heat input to the primary chamber, as necessary.
Primary Combustion Air Blower. Provides combustion air for the
primary chamber.
Kiln Seals. Sealing rings to minimize air in-leakage between the
rotating kiln and the kiln end plates.
Secondary Chamber. Chamber where final combustion of gases occurs.
Secondary Burner. Auxiliary fuel burner to maintain temperature of
the secondary combustion chamber.
Secondary Combustion Air Blower. Provides combustion air for the
secondary chamber.
Ash Container. Container for collecting ash exiting the lower end of
the kiln.
Stack. Vent for discharge of combustion gases to the atmosphere.
NODE OF INCINERATOR OPERATION
The design of the incinerator and associated equipment—such as waste
feed charging and ash removal systems—must be consistent with how the
incinerator will be operated. The opposite also is true—how you operate
your incinerator must be consistent with the design features. For the
purposes of discussion, we can define three basic modes of incinerator
operation.
1. Single batch;
2. Intermittent duty; and
3. Continuous duty.
SINGLE BATCH OPERATION
Single batch operation means the incinerator is loaded with a batch
of waste, sealed, and turned on. After combustion is completed, the
incinerator is allowed to cool and the ash is removed. Usually, ash is
not removed until the next day.
INTERMITTENT DUTY
Intermittent duty means that the incinerator is intermittently loaded
with batches of waste, one after another, over a period of time, usually
one to two work shifts. The batches might be fed at routine intervals—
such as every 5 minutes for 8 hours or might be fed at uneven intervals,
3-16
-------
whenever waste is available. In any event, the incinerator must be shut
down to remove ash from the system; thus, its operation is intlrmittlnt!
CONTINUOUS DUTY
24 hourfnpr0^ dut£, man*th* Incinerator can be continuously operated
c&i
remova1 "
WASTE FEED CHARGING AND ASH HANDLING SYSTEMS
WASTE FEED CHARGING SYSTEMS
Manual Feed. This means you load the waste
h°Pper' and the
Th!Ld00r ^J1**1^ tne hoPPer from the incinerator opens
The ram moves forward to push the waste into the incinerated
UtPraThrTrSe! t0 a11ocation ^hind the fire doo?
After the fire door closes, a water spray cools the ram and
' 3"d
,
ram retracts to the starting position.
• The system is ready to accept another charge
""
3-17
-------
Hydraulic Fire *f
Door Actuator I I
Hopper Cover
Hydraulic
Ram
Actuator
Waste
Charging
Hopper
Primary
Combustion
Chamber
Fire Door
Enclosure
Furnace
Opening
Figure 3-8. Hopper/ram mechanical waste feed system.
3-18
-------
START
WASTE LOADED INTO HOPPER
STEP1
F;**60OOH OPENS
STEP 2
RAM COMES FORWARD
STEP 3
BAM REVERSES TO CLEAR PIPE DOOR
STEP 4
FIR6000R CLOSES
STEPS
RAM (RETURNS TO START
Figure 3-9. Hopper ram charging sequence.
3-19
-------
dumper" which.automatically picks up a cart full of waste and dumps the
waste into the hopper.
Another type of mechanical feed system which has been used for rotary
kilns is an auger-feeder. The auger-feeder utilizes an auger (screw-type
device) at the bottom of the waste hopper to continuously feed the waste
into the kiln. However, these systems may cause problems with medical
wastes because red bags can break. Breaks may result in liquids leaking
from the feed system or in fugitive emissions of volatile organic
materials.
Mechanical charging systems have several advantages over manual
handling and charging:
• They provide added safety to the operating personnel by preventing
heat, flames, and combustion products from escaping the
incinerator during charging.
• They limit ambient air infiltration when charging a controlled-air
incinerator, thus, there is little impact on the combustion
rate.
• They enable incinerators to be automatically charged with smaller
batches of waste at regulated time intervals; this improves
operation and combustion efficiency.
ASH REMOVAL SYSTEMS
The ash remaining from the combustion process must be removed from
the Incinerator and disposed of in an acceptable manner. The ash is
removed either manually or mechanically.
• Manual removal is typical for smaller units.
• Manual or mechanical removal is practiced for medium-sized,
intermittent-duty incinerators.
• Mechanical semicontinuous removal of ash is necessary for
continuous-duty incinerators.
Manual Ash Removal. Manual ash removal means that you remove the ash
from the incinerator using a rake or shovel.
Mechanical Ash Removal. Continuous operation of an incinerator
requires some type of mechanical system for removing the ash while the
incinerator is operating. The mechanical system includes three major
components:
1. A means of moving the ash to the end of the incinerator hearth—
usually an ash transfer ram or series of transfer rams;
2. A collection device or container for the ash as it is discharged
from the hearth; and
3. A transfer system to move the ash from the collection point.
Manual ash removal is used for most multiple-chamber incinerators.
For controlled-air incinerators using mechanical ash removal, the ram used
3-20
-------
for waste charging often 1S used for pushing the ash to the discharge end
?t nneh Ihh I eaC!l new Waste charge is pushed into the incinerator,
it pushes the waste bed on the hearth forward towards the discharge end
Each repetitive charge continues to push a portion of the waste bed
towards the discharge end where it falls into a drop chute or water quench
P I w *
Figure 3-10 depicts an incinerator that has stepped hearths and
several individual ash transfer rams. This system is often used in larqer
incinerators. Each hearth has its own ash ram and the waste is pushed
from one hearth to the other by activating each ram in series, starting at
the discharge end of the hearth. In other words:
• The ash on the last hearth (3) is discharged by ram No. 3
• Ram No. 2 activates and pushes the waste on hearth No. 2 to hearth
no • «3 •
• Ash ram No. l activates and pushes the waste on hearth No. 1 to
hearth No. 2.
• Finally, a new charge is added to hearth No. 1.
n,,.h i Jaj0r advanta9e to this type of system is that when the waste is
?ed?Srihu?pSn!h?ehrth Vhe "ext* the waste bed is mi1d1* ^turned and
redistributed which provides some degree of "mixing" of the waste and
promotes more complete combustion. Another advantage is that the
underfire air to each hearth usually can be controlled separately which
allows for greater combustion control. ^arateiy, wnicn
trancing thj"h dr?ps from the hearth. some means of collecting and
transporting the ash is required. One type of collection system Gses an
IS « i 5 * ? K re? y to the d1schaHJe chute or positioned within an
fr^S 3 J"*6! be °W the hearth' A door or 9ate Wh1ch seal* the chute
is opened at regular intervals to allow the ash to drop into the
collection bin. When the bin is filled, the seal-gate is closed and the
*l* il nfTd a"d.rep1aced Wlth an empty bin. In the second method, the
ash is discharged into a water pit. The ash discharge chute is extended
into the water pit so that an air seal is maintained: The water bath
quenches the ash as the ash is collected. A mechanical device, either a
rake or drag conveyor system, is used to intermittently or continuously
froTthP *
-------
To Boiler
Secondary Burner
/- Primary Burner
Feed Ram
Ash Transfer Rams
Ash Discharge Ram
Ash Chute •
Ash Quench-
Ash Sump
Figure 3-10. Incinerator with staged hearth and automatic ash removal.7
3-22
-------
^ Comb1nation of induced draft and forced
-Sraft is the difference between the pressure within the
dnd to dlschargTthe combustion gass o the
fis%fS,s,::.-r;-a^ -
controlling incinerator draft are discussed in
BURNERS
3-23
-------
FORCED AIR BLOWER
The forced-air blower provides the combustion air needed to burn the
oil or gas fuel and, if oil is used, the atomizing air. A single forced-
air blower in conjunction with regulatory values may be used to supply air
to the different burners or each burner may have a separate air blower.
When the burner is first turned on, the blower comes on and purges the*
burner of any volatile gas or oil residues that may have built up since
the last burn. This is a safety feature.
FUEL TRAIN
The fuel train is the series of components that controls the flow of
fuel to the burner. The fuel train set up for gas and oil burners is
basically the same. Each fuel train has a pressure gauge, a manual
shutoff valve, and a solenoid shut-off valve. The only difference between
the gas and oil fuel trains is the device used to control fuel flow; the
oil fuel train utilizes a needle flow valve while the gas fuel train
utilizes a gas orifice union. The manual shut-off valves must be open
before the burners are turned on. The solenoid valves are safety valves
which close off the fuel supply if the burners do not light or if the air
supply for combustion is lost.
PILOT AND MAIN BURNERS
Each burner is equipped with both a pilot and main burner. The pilot
is lit first, and, once a flame is detected, the fuel supply to the main
burner is opened allowing the pilot to light the main burner. Proper
operation of the burners is best achieved by looking at the burner flame
pattern through the viewports in the incinerator wall or in the burner
itself. Some burners are equipped with an observation port to view the
main flame and another to view the pilot flame. Gas-fired burners have a
blue flame while oil-fired burners have a luminous yellow flame. The
flame pattern will likely vary with the type of burner. However, the
length of the flame should be such that the flame touches the waste but
does not impinge directly on the refractory floor or wall.
FLAME SAFEGUARD
The device which controls the burner ignition process is called the
flame safeguard. When the burner is first started, the burner blower
starts and when it reaches full speed, a purge timer starts. When the
purge timer times out, the flame safeguard energizes the pilot relay that
opens the pilot fuel supply and ignitor. When the pilot lights, a flame
detector (either an ultraviolet scanner.[gas or oil] or flame rod circuit
[gas only]) detects the pilot flame and causes the main flame relay to
activate the fuel supply to the main burner. The pilot then ignites the
main burner. The flame detector continues to operate and shuts the burner
down if the main burner fails. Additionally, if the air supply is lost,
both pilot and flame relays shut off the fuel supply. The pilot usually
is ignited for no more than 15 seconds (interrupted pilot). If the main
burner does not ignite during the pilot ignition period, the flame
3-24
-------
WASTE HEAT BOILERS
«d^«^^^^
control system) is added to the incinerator system SlnS tKVS
3-25
-------
<^
Bypass X
Shutoff \
Valve X
H
Bypass
Stack
Gas Flow
Stack
Damper
ID
Fan
Incinerator
Waste Heat
Boiler
Figure 3-11. Incinerator with waste heat boiler and bypass stack.2
3-26
-------
REVIEW EXERCISE
1.
3.
4.
Which type of incinerators listed below
use combustion in two chambers?
a.
b.
c.
d.
e.
Control led-air incinerators
Multiple-chamber incinerators
Rotary kilns
All of the above
a and b
2.
The unique feature of the controlled-air
incineration principle is:
a. Large incinerators can be built
b. Combustion is controlled by limiting
the air in the primary chamber to
below stoichiometric; combustion
occurs in two stages
c. The combustion chambers are shaped
like cylinders
Continuous-duty incinerators must include
which of the following importanFfeatures
not normally included in intermittent-
duty incinerators?
a. Automatic waste feed
b. Continuous ash removal
c. Temperature monitors
1. d. All of the above
2. b.
3. b.
The primary
chamber operates
with starved air
and combustion
occurs in two
stages.
Continuous ash
removal
An incineration
the following:
includes which of
a.
b.
c.
d.
e.
f.
Waste feed charging system
Incinerator
Ash removal system
Control and monitoring system
All of the above
b and d
4. e. All of the above
3-27
-------
REFERENCES FOR. SESSION 3
1. Air Pollution Control District of Los Angeles County. Air Pollution
Engineering Manual, 2nd Edition AP-40. (NTIS PB 225132).
U. S. EPA. May 1973.
2. Ecolaire Combustion Products, Inc. Technical Article: Principles of
Controlled Air Incineration. Undated.
3. McRee, R. Operation and Maintenance of Controlled Air
Incinerators. Ecolaire Environmental Control Products. Undated.
4. Consertherm® Systems. Technical Data Form For Rotary Kiln,
Industronics, Inc. Undated.
5. Doucet, L. Waste Handling Systems and Equipment. Fire Protection
Handbook, 16th Edition. National Fire Protection Association.
6. Consumat Systems, Inc. Technical Data Form For Waste Feed System.
Undated.
7. U. S. Environmental Protection Agency. Source Category Survey:
Industrial Incinerators. EPA 450/3-80-013 (NTIS PB 80-193303).
May 1980.
8. Ashworth R. Batch Incinerators—Count Them In; Technical Paper
Prepared for the National Symposium of Infectious Waste.
Washington, D.C. May 1988.
9. Ecolaire Combustion Products, Inc. Technical Data Sheet for E Series
Incinerator. Undated.
10. Doucet, L. C. Controlled Air Incineration: Design, Procurement and
Operational Considerations. Prepared for the American Society of
Hospital Engineering, Technical Document No. 55872. January 1986.
11. U. S. Environmental Protection Agency. Hospital Waste Combustion
Study: Data Gathering Phase. EPA 450/3-88-017. December 1988.
12. Brunner, C. R. Incineration Systems. Van Nostrand Reinhold. 1984.
13. Personal conversation with Larry Doucet, Doucet & Mainka Consulting
Engineers. November 28, 1988.
14. Cleaver Brooks®. Operation, Maintenance, and Parts Manual for the
Pyrolytic Incinerator. Publication No. CBL-6826. September 1988.
15. Letter from K. Wright, John Zink Company, to J. Eddinger, EPA.
January 25, 1989.
3-28
-------
SESSION 4.
AIR POLLUTION CONTROL EQUIPMENT DESIGN AND FUNCTIONS
-------
SESSION 4. AIR POLLUTION CONTROL EQUIPMENT DESIGN AND FUNCTIONS
TABLE OF CONTENTS
SESSION GOAL AND OBJECTIVES 4_1
INTRODUCTION 4.1
WET SCRUBBERS - GENERAL 4-1
Pollutants Controlled 4_1
Pollutant Collection Principles 4-1
Types of Wet Scrubbers Used on Hospital Incinerators 4-2
PACKED-BED SCRUBBERS 4_2
Pollutants Control led 4_2
Description of Packed-Bed Scrubber 4_2
How Does a Packed-Bed Scrubber Work? 4_2
VENTURI SCRUBBERS 4.5
Pollutants Control led 4-6
Description of Venturi Scrubber 4-8
How Does a Venturi Scrubber Work? 4-8
SPRAY TOWERS 4-8
Pollutants Controlled 4_11
Description of Spray Tower Scrubber 4-11
How Does a Spray Tower Scrubber Work? 4-11
FABRIC FILTERS 4-11
Pol lutants Control led 4-11
Pollutant Collection Principles 4-11
Description of a Pulse-Jet Fabric Filter 4-13
How Does a Pulse-Jet Fabric Filter Work? 4-13
DRY SCRUBBERS - GENERAL 4-14
Pollutants Control led 4-14
Pollutant Collection Principles 4-14
Types of Dry Scrubbers Used on Hospital Incinerators 4-14
SPRAY DRYERS 4-14
Description of Spray Dryers 4-14
How Does a Spray Dryer Work? 4-14
DRY INJECTION 4-17
Description of Dry Injection 4-17
How Does Dry Injection Work? 4-17
ELECTROSTATIC PRECIPITATORS 4-19
Pollutants Control 1 ed 4-19
Pollutant Collection Principles 4-19
Description of a Single-Stage, Hot-Side, Plate ESP 4-19
How does an ESP Work? 4-21
REFERENCES FOR SESSION 4 4-27
-------
SESSION 4. AIR POLLUTION CONTROL EQUIPMENT DESIGN AND FUNCTIONS
LIST OF FIGURES
Page
Figure 4-1. Impaction..
Figure 4-2. Absorption. . .
Fiour 45' r • -^ W rectan9"^ throat
ngure 4-5. Cyclonic mist eliminator .....
tl:
11:
if r?'-0^ M^aSsrS^-'""' fl
4-12. Discharge and collection plate electrodes fo^ ....... 4'2°
a p i ate tsp
Figure 4-13. Single-stage, "'''
-------
SESSION a.
AIR POLLUTION CONTROL EQUIPMENT DESIGN AND FUNCTIONS
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with the components and the functions of
that
OBJECTIVES
Upon completing this session, you should be able to:
incinerator^ ^ ^ °f ^ P°11Uti°n C°ntro1 S*Stem used °n your
intended t^nW P°11UtdntS thdt y°Ur ^r P°11ution control system is
system;' and""*1^ ^ maj°r Components of ^our *ir pollution control
5. List the functions of each major component.
INTRODUCTION
During this session we will discuss the various tvoes of APrs ,,«,,,ii
-'^
• Wet scrubbers
— Packed-bed scrubbers
— Venturi scrubbers
— Spray towers
• Fabric filters
• Dry scrubbers
— Spray dryers
— Dry injection
• Electrostatic precipitators
WET SCRUBBERS - GENERAL
POLLUTANTS CONTROLLED
4-1
-------
POLLUTANT COLLECTION PRINCIPLES
• Participate matter - collection mechanism is primarily impaction
on wetted surfaces or in liquid droplets. Figure 4-1 shows
impaction.
• Gases - gaseous collection is through diffusion and absorption.
Figure 4-2 shows absorption.
• After capture of the pollutants in the liquid, the liquid droplets
must be separated from the clean gas stream.
TYPES OF WET SCRUBBERS USED ON HOSPITAL INCINERATORS
• Packed-bed scrubbers
• Venturi scrubbers
• Spray towers
PACKED-BED SCRUBBERS
Figure 4-3 shows a packed-bed scrubber.
POLLUTANTS CONTROLLED
• Packed-bed scrubbers are used primarily for acid gas control.
• While packed-bed scrubbers remove some particulate matter, they
have a low collection efficiency for fine particulates.
DESCRIPTION OF PACKED-BED SCRUBBER
Packed-bed scrubbers consist of:
• A cylindrical shell to house the scrubbing media;
• Packing media and supporting plates;
• Liquid spray nozzles to distribute the scrubbing liquid;
• Demister pads to remove liquid droplets from the clean flue gas;
and
• An induced draft fan for moving the flue gas through the scrubber.
The packing media is composed of 1- to 3-inch (2.5- to 7.6-cm)
diameter plastic shapes that are intended to maximize the surface area.
HOW DOES A PACKED-BED SCRUBBER WORK?
The scrubbing liquid used is important.
• With water as the scrubbing liquid there is removal of soluble
gases. HC1 is highly soluble in water and is efficiently captured
in wet scrubbers.
4-2
-------
Gas streamlines
/ \ Droplet
Particle
Figure 4-1. Impaction.
4-3
-------
Gaseous
pollutant
Figure 4-2. Absorption. 1
4-4
-------
CLEAN EXHAUST
DIRTY EXHAUST
SHELL
MIST ELIMINATOR
LIQUID SPRAYS
PACKING
Figure 4-3. Countercurrent-flow packed-bed scrubber.
4-5
-------
• Alkaline (caustic) materials, such as lime, are added to the water
to neutralize the acids collected in the scrubbing liquid. The
liquid is neutralized to reduce corrosion of equipment and keep
the pH (a measure of the water's acidity) of the water discharge
within acceptable ranges required by wastewater treatment
facilities.
• Addition of alkaline materials is needed to achieve significant
reductions of acid gases, such as S02 which are less soluble in
water than is HC1.
Packed-bed scrubbers are designed to maximize the surface area of the
liquid/gas interface to increase opportunities for absorption of the acid
gases at low fan energy costs. Relatively large amounts of scrubbing
liquid per unit of flue gas are used.
• Packed-bed scrubbers intended for acid gas control use an alkaline
scrubbing liquid; example materials are:
-- Lime (CaO);
~ Sodium hydroxide (NaOH); and
— Sodium carbonate (Na2C03).
• Scrubbing liquid is sprayed onto the packing media from the top
and bottom.
• The liquid passes downward due to gravity, wetting the surface of
the packing media.
• The dirty flue gases enter the bottom of the scrubber and travel
countercurrent (opposite) to the flow of the liquid.
• The wet surface of the packing media creates a large surface area
of liquid/gas interface for absorption.
• The acid gases are absorbed and captured in the liquid.
• The acid gases react with the alkaline materials in the scrubbing
liquid and are neutralized.
• Particulate matter is collected in the scrubbing liquid through
impaction.
• The flue gases pass out the top of the scrubber unit through the
demister pads which remove any entrained droplets of liquid that
may contain absorbed acid gases and particulate matter.
• The dirty scrubbing liquid containing the collected particulate,
acid gas/sorbent reaction products, and the unreacted sorbent
materials passes out the bottom of the scrubber and is recycled or
sent to wastewater treatment.
VENTURI SCRUBBERS
Figure 4-4 shows a venturi scrubber.
POLLUTANTS CONTROLLED
Venturi scrubbers are high-energy scrubbers used for the control of
fine particulate emissions. Hydrochloric acid gas, if present, also is
controlled by a venturi scrubber.
4-6
-------
DIRTY FLUE GAS
SPRAY NOZZLES
LIQUID INLET
VENTURI THROAT-
CYCLONIC MIST
ELIMINATOR
Figure 4-4. Spray venturi with rectangular throat.
4-7
-------
DESCRIPTION OF VENTURI SCRUBBER
• A venturi scrubber consists of:
-- A constriction in the ductwork referred to as a venturi
throat;
— Spray nozzles at the entrance to the venturi throat that
supply the scrubbing liquid, usually water;
— A cyclonic mist eliminator for removing entrained water
droplets; and
-- An induced draft fan for moving the flue gas through the
scrubber
• Some venturi scrubbers have an adjustable throat that can be used
to vary the size of the opening.
HOW DOES A VENTURI SCRUBBER WORK?
Venturi scrubbers are designed to maximize turbulence and mixing of
water droplets and dirty flue gas to improve pollutant capture efficiency.
• The venturi throat has the smallest cross-sectional area in the
ductwork and consequently the gas has the highest speed at this
location.
• As the flue gases speed up at the entrance to the venturi section,
water is injected into the flue gas stream through spray nozzles
or through the force of the high speed gases passing over water
running down on the sides of the venturi.
• The high gas speeds through the constricting throat create
turbulence which breaks the water droplets into smaller fine
droplets and causes mixing.
• Collection efficiency increases with higher gas speeds and
turbulence; however, higher gas speeds require more energy. The
amount of energy is measured as the change in pressure across the
venturi or the pressure drop in inches of water column. For
scrubbers with adjustable throats, decreasing the size of the
throat opening increases pressure drop and collection efficiency.
• Higher pressure drops require more fan energy and result in higher
operating costs.
• The water droplets, containing the captured particulate matter,
are separated from the clean gas stream in the cyclonic mist
eliminator using centrifugal force. Figure 4-5 shows a cyclonic
mist eliminator.
• The dirty scrubber water is sent to wastewater treatment. Some
facilities may recycle the scrubber water after it goes through a
settling tank. If your facility has such a recycle system, the
solids content and pH of the recycle waters must be controlled.
SPRAY TOWERS
Figure 4-6 shows a spray tower scrubber.
4-8
-------
Clean exhaust gas
Clean
exhaust gas
containing droplets
Figure 4-5. Cyclonic mist eliminator.
4-9
-------
Liquid
sprays
Figure 4-6. Countercurrent-flow spray tower.]
4-10
-------
POLLUTANTS CONTROLLED
Spray towers are low-energy scrubbers used to control large-particle
emissions.
• Spray towers are only effective for relatively large particles and
are limited in applicability to multiple chamber incinerators.
• Controlled-air incinerators have inherently low particulate mass
emission rates and fine particle size distributions that cannot be
effectively controlled by spray towers.
DESCRIPTION OF SPRAY TOWER SCRUBBER
Spray towers are relatively simple scrubbers consisting of:
• A hollow cylindrical steel vessel; and
• Spray nozzles for injecting the scrubbing liquid.
HOW DOES A SPRAY TOWER SCRUBBER WORK?
Spray towers are designed to use many spray nozzles to create a large
amount of fine liquid droplets for impacting and capturing particulate
matter.
• The dirty exhaust gas enters the bottom of the scrubber and
travels upward.
• Water droplets are sprayed downward by a series of spray nozzles
designed to cover the entire cross-sectional area of the scrubber.
• The cleaned exhaust gas exits out the top of the scrubber.
FABRIC FILTERS
Figure 4-7 shows a pulse-jet fabric filter.
POLLUTANTS CONTROLLED
Fabric filters are designed to remove solid particulate matter from
the flue gas stream by filtering the flue gas through fabric bags.
• Fabric filters are especially effective at removing fine
particulate matter.
• When used with a dry scrubber (see next section), the fabric
filter cake will help remove acid gases from the flue gases.
POLLUTANT COLLECTION PRINCIPLES
• Particulate - the dirty flue gases are passed through fabric bags
which filter out the particulate matter creating a "cake" (i.e., a
coating) of collected particulate matter on the bag that further
increases filtration. The principle is very similar to that of a
household v.acuum cleaner.
4-11
-------
Clean Air Plenum
Blow Pipe
Housing
Bag Retainer
Dirty Air Inlet and Diffuser'.
To Clean Air Outlet
*. and Exhauster
Tubular Filter Bags
Dirty Air Plenum
^ Rotary Valve Air Lock
Figure 4-7. Pulse-jet baghouse.
-------
^
filter bag along with the pollutants. As the acid aases Sass
DESCRIPTION OF A PULSE-JET FABRIC FILTFR
A pulse- jet fabric filter consists of-
~ 2M,r JM.; sM'jsr* W1th holes in ft that
"" ty lr chamber or ^num which contains the fabric
re?ainers;r ba9S w1th suPP°rtin9 W1>« frame b
IttachPH^nH 3!!- rntUri'S to which the individual bags are
attached and whnch inject the pulse of cleaning air into the
coiiected
*1r 10Ck Whl'Ch d1scha^s the ash from the
HOW DOES A PULSE-JET FABRTQ FILTER WORK?
Sags' arrcler^ Or " re-e™^ P^^ure drop, the
-Jected ,'nto
« S SS-
4-13
-------
DRY SCRUBBERS - GENERAL
POLLUTANTS CONTROLLED
Dry scrubbers remove acid gases, primarily HC1 and S02.
POLLUTANT COLLECTION PRINCIPLES
Dry scrubbers inject alkaline sorbent materials into the dirty flue
gas. The acid gases begin to react with the alkaline sorbents to produce
solid particulate salts that are collected by a particulate control
device, usually a fabric filter (see previous section), that follows the
dry scrubber. The unreacted sorbent is also captured on the fabric filter
cake where additional acid gas reacts with the sorbent and is captured.
TYPES OF DRY SCRUBBERS USED ON HOSPITAL INCINERATORS
• Spray dryers
• Dry injection
SPRAY DRYERS
DESCRIPTION OF SPRAY DRYERS
• Figure 4-8 shows a schematic of a spray dryer system. Figure 4-9
shows an internal view of the spray dryer absorber vessel.
• The primary components of a spray dryer system are:
— Lime slaker, if pebble lime is purchased;
— Sorbent mixing tank;
« Sorbent feed tank;
~ Atomizer feed tank;
— Rotary atomizers or air atomizing nozzles;
— Spray dryer absorber reaction vessel;
— Solids recycle tank; and
~ Particulate control device.
HOW DOES A SPRAY DRYER WORK?
Spray dryers are designed to spray an alkaline slurry of sorbent
material into the hot flue gases where the acid gases are absorbed into
the slurry droplets and reacted with the alkaline material to form solid
particle reaction products.
• Spray dryer facilities usually purchase pebble lime (CaO) for use.
• The pebble lime is converted to calcium hydroxide [Ca(OH)2] by the
addition of water in the slaker.
• The calcium hydroxide is mixed with water in the mixing tank to
produce a slurry containing 5 to 20 percent solids.
• The slurry is stored in the feed tank and is transferred to the
atomizer feed ta1- immediately prior to use.
• The atomizers pr 2 small droplets of slurry that are injected
into the absorbe action vessel.
4-14
-------
Lime
Storage
Slurry
Mixing
Tank
Slurry
Feed
Tank
1
StacK
Combustion
Gases
Figure 4-8. Components of a spray dryer absorber system.
4-15
-------
SORBENT SLURRY
FLUE GAS
SPRAY NOZZLE
TO BAGHOUSE
REHEAT DUCT
Figure 4-9. Spray dryer absorber vessel.
4-16
-------
n.
stream or drops to the bottom of the reaction vlsse? 3"
.
solids recycle tank for recycle back to the mixing tank
DRY INJECTION
Figure 4-10 shows a dry injection system schematic.
DESCRIPTION OF DRY INJECTION
Dry injection systems consist of:
Dry sorbent storage tank;
Kct'orT PneUmat1C line for transfer of the sorbent;
Expansion/reaction chamber (optional); and
(M>r1e f1'W " «P> «* "Hectlon
not Inc."5"' e "^"Slo"/^«t'on ch»ber sho«n fn Figure 4-10 1,
HOW DOES DRV IKJECTION WOBK?
that
*»" «" -^"tlc line to the
The soroent 1s injected into the flue gas duct which rro»t»<
turbu,ence that results in nixing of th'e'sorbent^nh'thellue
y the sorbent NH~ m the Hue gas
4-17
-------
Sorbent
Storage
Blower
Feeder
Pneumatic
Line
Stack
Combustion
Incinerator
Waste
Heat
Boiler
Injector
Combustion
Air Hurt
Expansion/
Reaction
Chamber
Solid
Residue
Figure 4-10. Components of a dry injection absorption system.
4-18
-------
The sorbent and reaction products are carried by the flue aas
the paniculate control device where the solids are collcted
ELECTROSTATIC PRECIPITATORS
POLLUTANTS CONTROLLED
=• - w= rare
POLLUTANT COLLECTION PRINCTPl FS
sea
DESCRIPTION OF A SINGLE-STAGE. HOT-SIDE, PLATE ESP
'
" ' "
, ,
These units use very high voltage to charge particles The
4-19
-------
SorOent
Storage
Blower
Feeder
Iniector
Combustion ^
incinerator
Waste
Heat
Boiler
i r
Contactor
Reactor
Stack
Solid
Residue
ID
Fan
Figure 4-11. Components of a dry injection adsorption system,
4-20
-------
ESP s are grouped according to the temperature of the flue
entering the unit. Therefore, the ESP's used on medfca !
incinerators are likely to be hot-side units Thief «i
°fa^^^
(wires) especially spaced between rows of plates Floure 4 ??
shows the gas flow through a plate ESP and the scharoe and
collection plate electrodes. Discharge electrodes are
hot-,,* put.
the
dischar9e and
matter that
hopper"86 de"'Ce that rem0ves the co"e«" -t«-1.l
electrode alignment and configuration
HOW DOES AN ESP WORE?
The following steps in sequence describe how an ESP works:
* Jil!rSi"VOlt?9e; Pu1satin9« direct current is applied to the
discharge electrodes and the collection electrodes with the
4-21
-------
Discharge
electrode
Collection
electrode
Figure 4-12. Plate ESP.
4-22
-------
Rappers
Discharge
electrodes
J , , Flue gas
in
Collection
electrodes
Hoppers
Figure 4-13. Electrostatic Precipitator.
4-23
-------
As the. dirty gas comes into contact with the corona, the gas
particles become negatively charged.
The negatively charged particles migrate to the collection
electrode because they are repelled from the negatively charged
discharge electrodes (like charges) and attracted to the
collection electrodes (opposite charges).
When the charged particles reach the collection plate, the charge
on the particle is only partially discharged. The charge is
slowly leaked to the grounded collections electrode. A portion of
the charge is retained and allows the particle to adhere to the
plate and promotes cohesion of other particles to the collected
particles on the plate.
The collection plates are rapped periodically to remove the
collected particles. Plates are rapped when the accumulated dust
layer is relatively thick (0.03 to 0.5 inches [0.01 to
0.2 centimeters)). This procedure allows large sheets of dust to
fall off the plates and helps eliminate dust reentrainment.
The dislodged dust falls into the hopper where it is removed with
a hopper discharge device such as a slide gate or drawer (manual
dust removal) or a trickle valve, rotary airlock valve, screw
conveyor, or pneumatic conveyor (automatic dust removal).
4-24
-------
REVIEW EXERCISE
1. Which of the following types of air
pollution control devices are used on
hospital incinerators?
a. Wet scrubbers
b. Fabric filters
c. Dry scrubbers
d. All of the above
2. Fine particulate emissions are controlled 1. d. All of the above
very effectively by which types of MIi or the above
devices?
a. Packed-bed scrubbers
b. Venturi scrubbers
c. Fabric filters
d. Dry scrubber systems
e. Electrostatic precipitators
3. Pulse-jet fabric filters use a blast 2. b, c, d, and e
or for cleaning the bags
4. A dry scrubber is always followed by a 3. compressed air
high efficiency particulate matter
control device. True or False?
5. Where does acid gas removal from the flue 4. True
gas occur in a dry injection system?
a. Venturi contactor
b. Flue gas ductwork
c. Fabric filter
d. All of the above
6. Both the spray dryer and dry injection 5. d. All of the above
types of dry scrubbers inject dry
alkaline sorbent into the flue gas
stream. True or False?
(continued)
4-25
-------
REVIEW EXERCISE (CONTINUED)
A venturi scrubber's control efficiency
and operating costs increase with
increased gas velocity and pressure drop
in the venturi throat. True or False?
The majority of the fine particulate
collected by a fabric filter is filtered
out by the .
False. The spray
dryer injects liquid
slurry.
True
8. filter cake
4-26
-------
REFERENCES FOR SESSION 4
1. Joseph, J and D. Beachler. APTI Course SI:412C, Wet ScrubhPr
Review - Self Instructional Guidebook. EPA 450/2-82-020
U. S. Environmental Protection Agency. March 1984.
?"?"**1 Pr°tection ^ncy. Control Techniques for
Emissions from Stationary Sources Volumes 1 *nH ?
EPA 450/3-81-005a,b. (NTIS PB 83-127498)" September 1982
3. Beachler D and M Peterson. APTI Course SI:412A, Baghouse Plan
R'U1kEM 450/2-82-005' U« '
^
U. S. Environmental Protection Agency. June 1987.
6' RRev?sion f^BSHSd for'th^?^0'',:30^" F'eld InsP«t1on Notebook;
A^r1po??ut^•onPfr;?nlngXtHute.S•JuEnn^I908^rta' Pr°te"1
7. U. S. Environmental Protection Agency. APTI Course SI
4-27
-------
SESSION 5.
MONITORING AND AUTOMATIC CONTROL SYSTEMS
-------
SESSION 5. MONITORING AND AUTOMATIC CONTROL SYSTEMS
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 5-1
INTRODUCTION 5_2
OPERATING PARAMETERS 5_7
Incinerator Operating Parameters 5.7
Wet Scrubber Operating Parameters 5.7
Fabric Filter Operating Parameters 5.7
TYPES OF AUTOMATIC CONTROL SYSTEMS 5_7
Manual Control 5.7
Automatic Timer Sequence 5_7
Automatic Control 5_H
MONITORING AND CONTROL EQUIPMENT 5-11
Temperature 5_11
Incinerator Draft and APC Pressure Drop 5-11
Oxygen Concentration 5.12
Carbon Monoxide Concentration 5-12
Opacity 5-17
Charging Rate 5-17
Scrubber Liquid pH 5-17
REFERENCES FOR SESSION 5 5-20
LIST OF FIGURES
Figure 5-1. Schematic of a temperature monitoring system.... 5-3
Figure 5-2. Schematic of a temperature control loop , 5-4
Figure 5-3. Thermostat with temperature "setpoint" , 5-5
Figure 5-4. Temperature controller/meter , 5-6
Figure 5-5. Barometric damper , 5-13
Figure 5-6. Constant speed fan with damper control 5-14
Figure 5-7. Schematic of in situ and extractive monitors..., 5-15
Figure 5-8. Schematic of extractive monitoring system , 5-16
Figure 5-9. Typical transmissometer installation for
measuring opacity 5-18
-------
LIST OF TABLES
TABLE 5-1 TYPJCALEMONITOR AND CONTROL PARAMETERS FOR
5-8
TABLE 5-2. TYPICAL MONITOR AND CONTROL PARAMETERS FOR SCRUBBERS. 5-9
TABLE 5-3. TYPICAL MONITOR AND CONTROL PARAMETERS FOR FABRIC
5-10
-------
SESSION 5.
MONITORING AND AUTOMATIC CONTROL SYSTEMS
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with:
n befween a Para™*er that is monitored and
Stored; * C°ntrolled and a Par™*er that is simp™
* mohnito?edS;'°f °perat1ng Pa™^rs that may be controlled or
" ImorsTanr5 °f automat1c contro1 s^tems used on incin-
• The types of monitors that may be included on your
incinerator/air pollution control system.
OBJECTIVES
Upon completing this session, you should be able to:
monitored; Ut "" °perating P«™*ters that may be controlled and/or
a
^^^
systems
5-1
-------
INTRODUCTION
The type of control system and the operating parameters that are
monitored will be different for each incinerator. In this session, the
parameters most likely to be monitored and/or controlled are discussed.
It is important to make a distinction between a parameter that is
monitored and a parameter that is monitored and automatically
controlled. When a parameter is monitored, it means that information is
obtained by a sensing device in the incinerator and the information is
transmitted to a receiver such as a display meter or recorder for you to
view. However, the information from the sensor does not automatically
control any operations. Figure 5-1 is a simplified schematic of a
temperature monitoring system.
When a monitored parameter is used for control, the information
transmitted from the sensor is used to adjust some function(s) within the
incineration system that in turn controls the monitored parameter. The
control system includes a controller to send a signal to the operating
system which is adjusted. Figure 5-2 is a simplified schematic of a
temperature control loop which adjusts the primary chamber combustion air
blower and burner operations to control the temperature. Control systems
use setpoints for the monitored/controlled parameter (in this case the
primary chamber temperature) to determine when action will be initiated
for the adjusted parameter (in this case, increasing/decreasing the
combustion air and turning on or off the primary burner).
A simple control system which you are all familiar with that uses a
setpoint is the household thermostat, as shown in Figure 5-3. The desired
temperature of the room is set, and the furnace automatically turns on and
off in order to maintain this temperature. A temperature dial is provided
so you can monitor the room temperature. An example of a temperature
monitor/control display which is used on an incinerator is presented in
Figure 5-4. This controller has low and high setpoints. Two pointers are
used for setting the high and low setpoints, and the third pointer
indicates the actual temperature.
So that you can fully appreciate how your incinerator operates, you
should know
Which parameters are monitored and how the monitored value is
displayed; and
• Which of the monitored parameters are automatically controlled,
and what incinerator operating functions they adjust.
The next section lists the most frequently monitored/controlled parameters
and the operating functions that they may be used to adjust. Each
incinerator will use different monitoring and control systems.
5-2
-------
CONTROL ROOM
Recorder
t
I
Burner
Combustion
Chamber
Figure 5-1. Schematic of a temperature monitoring system.
5-3
-------
CONTROL ROOM
r
Signal
Processor
Recorder
L.
•C
Burner
Combustion
Air
Blower
Combustion
—: Chamber
Figure 5-2. Schematic of a temperature control loop.
-------
Temperature
Meter
so-
so-
70-
60-
50-
Ace Heating and Cooling
Set Point
Figure 5-3. Thermostat with temperature "setpoint."
5-5
-------
ROTATE OUTER DIAL TO
SELECT TEMPERATURE
SETPOINTOR PROPORTIONAL
SETPOINT
ROTATE INNER DIAL TO
SELECT TEMPERATURE
SETPOINT
TEMPERATURE
INDICATOR
COCKING SCREW
LOCKS DIAL
POSITION
Figure 5-4. Temperature controller/meter.
5-6
-------
OPERATING PARAMETERS
INCINERATOR OPERATING PARAMFTFRS
°ther Posters are monitored Snly on
MET SCRUBBER OPERATING PARAMFTFPS
FABRIC FILTER OPERATING PARAMETERS
TYPES OF INCINERATOR AUTOMATIC CONTROL SYSTEMS
MANUAL CONTROL
AUTOMATIC TIMER SEQUEHCF
' '
to
5-7
-------
TABLE 5-1. TYPICAL MONITOR AND CONTROL PARAMETERS FOR INCINERATORS.
Monitored/control led
parameter
Purpose
Incinerator
functions controlled
(when applicable)
Temperature (primary and
secondary chambers)
Draft
Oxygen
Carbon monoxide
Opacity
Charge rate
Indicates temperature
operating range;
Control parameter
Indicates pressure in
chamber;
Control parameter
Indicates excess air
level
Indicator of combus-
tion efficiency
Indicator of emissions
Records charge rate
Combustion air
Auxiliary burners
Barometric damper
ID fan damper
Combustion air
Automatic feed
system interlock
5-8
-------
TABLE 5-2. TYPICAL MONITOR AND CONTROL PARAMETERS FOR SCRUBBERS.
Monitored parameter
Pressure and pressure drop
Scrubber liquid flow rate or pressure
Scrubber liquid pH
Inlet temperature
Scrubber functions
controlled (when applicable)
Venturi throat
ID fan
Liquid flow control valve
Caustic flow control valve
Emergency quench/dilution
air
Bypass stack
Prequench
5-9
-------
TABLE 5-3. TYPICAL MONITOR AND CONTROL PARAMETERS FOR FABRIC
FILTERS
Monitored parameter
Fabric filter operating
functions controlled
Pressure drop
Inlet gas temperature
Cleaning cycle
Emergency bypass stack
5-10
-------
hiah J?re rllllh^H"^lu*1?? dre turned on/off or shifted from low to
sptnoint* rj« n™ ?5 ,1°? * timer se«uence- Low and high temperature
?™?£ IV pr°vlded to override the time control sequence if the
low/high temperature setpoints are exceeded; that is, if the high
vT" u^h SeP£lSeJS|Sfded' ^ P™ ^ ^^ * ^ "™
even tnougn tne burner would normally be operating at a
the time sequence.
AUTOMATIC CONTROL
nm C0ntro1 system' the combustion air
-SFSS was
MONITORING AND CONTROL EQUIPMENT
monito?eor°controi X?10nS J?scr1be the types of instrumentation used to
monitor or control the operating parameters described previously.
TEMPERATURE
JS°rS!fS arV?ed t0 mon1tor temperatures in the incinerator's
JStion chambers and inlPt n»« *« +-KO =,,•—~-i-i..*.s ,_.__,."' *
o
eh±e^ ^™^^^™^^£^
temperature gauge. The chart recorder provides a permanent reco?5 of the
^;=e^^^
reported to the nuintenance
Pratures are ^intained through the use of temperture
auxiliary fuel or by adjusting the combustion^ supply or both.
INCINERATOR DRAFT AND APC PRESSURE DROP
issure drop is measured with a differential pressure gauge To
incinerator draft, one side (high-pressure side) of this
nt is always open to the ambient air while the other side (low-
c^e^JnlL'atT^I c^^
5-11
-------
barometric damper for natural draft systems. Figure 5-5 is a schematic of
a barometric damper. The damper automatically opens and closes (via a
mechanical system) to maintain a constant pressure differential between
the incinerator chamber and the atmosphere, as measured by the draft
monitor. For induced draft systems, the draft typically is controlled by
opening and closing a damper located before or after the induced draft
fan. Figure 5-6 shows a damper control system for an induced draft fan.
Airflow is decreased as the damper is closed, as depicted in the figure.
The damper can be adjusted manually or can be automatically adjusted by a
mechanical system based upon the output from the draft monitor.
To monitor the pressure drop across an ARC device, a differential
pressure gauge also is used. The high-pressure side of the gauge is
connected upstream of the control device and the low-pressure side is
connected downstream of the control device to measure the pressure drop
across the APC.
OXYGEN CONCENTRATION
Some incinerators may be equipped with oxygen monitors. The oxygen
sensor typically is located in the duct to the stack or in a duct at the
exit of the secondary combustion chamber. These monitors analyze the
oxygen concentration in the combustion gases from the secondary combustion
chamber so that the operator can ensure that enough oxygen is available
for proper combustion. For some incinerators with oxygen analyzers, the
oxygen levels measured are used to automatically control the combustion
air feed rates to the incinerator.
The two main designs used for oxygen analyzers are in situ and
extractive analyzers. Figure 5-7 depicts the in situ and extractive
designs. In situ oxygen analyzers provide rapid response to changes in
the oxygen content of the gas because the sensor is actually mounted in
direct contact with the gas stream. The extractive technique involves the
continuous withdrawal of a sample of gas that is transported via a sample
line to the analyzer which is located some distance from the sampling
point. Figure 5-8 is a schematic of an example extractive analyzer system
showing the gas conditioning and calibration components of the system.
CARBON MONOXIDE CONCENTRATION
Some incinerators may be equipped with carbon monoxide (CO)
monitors. These monitors analyze the CO concentration in the combustion
gases from the secondary combustion chamber to ensure that proper combus-
tion conditions are maintained and CO emissions are minimized. In
general, high CO levels indicate that incomplete combustion is
occurring. Typically, CO monitors are not part of the automatic process
control system.
As with oxygen analyzers, CO analyzers usually are located at the
secondary combustion chamber exit or in the stack breaching and may be
either in situ or extractive. However, CO analyzers are usually
5-12
-------
Air
To
Atmosphere
"Draft-
Stack
•Incinerator
Figure 5-5. Barometric damper.
5-13
-------
Damper Fully Open
Fan
Damper Partially Closed
XZIO
'
Fan
Stack
Stack
Figure 5-6. Constant speed fan with damper control
5-14
-------
Source-
In-Situ
Stack
LJ
• -Detector
n
lr Detector Cell
Electronics
Extractive
Stack
ProbeL
/Sample
Slransport
JAnalyzer
Figure 5-7. Schematic of in situ and extractive monitors.
5-15
-------
f
J -
c
)
SECONDARY
COMBUSTION
CHAMBER
t 1
r
,
SAMPLE
"N
• PROBE f
BACK FLUSH
PURGE AIR
DRAIN
SAMPLE
PUMP
ZERO
SPAN
1
LOW
MID
LEVEL LEVEL
CAL. CAL
Figure 5-8. Schematic of extractive monitoring system.
-------
extractive because water vapor in the exhaust gas interferes with the CO
nanthef°r' ' be rem°Ved through gas condUionJn s?es
assocadwithh' as cononn seps
associated with the extractive analyzer. Problems with CO analyzers are
''" PlU"a9e 1" the SySt6m °r Sma11 a1r
distort
OPACITY
Opacity monitors (transmissometers) are used as indicators of proper
operation rather than as part of the automatic control system. Opacity
monitors are almost always located in the stack or stack breeching and
measure the amount of light absorbed by the stack plume from a light
source directed across the stack. Figure 5-9 is a schematic of
transmissometer installation. A transmissometer cannot be used after a
Ubber beCaUSe the gas stream Conta1ns so much "^sture that a
plume caused by the moisture interferes with the opacity
measurement.
CHARGING RATE
Man,ia? -f ha^ng rate can be monitored manually or automatically.
Manual monitoring involves weighing each load of waste and recording the
nr 25 £ Vhe Chauge< Automatic monitoring involves use of a weigh scale
nn ?EPer *?** au^atically records the weight of each charge
on the scale or in the hopper. y
SCRUBBER LIQUID pH
JSnuhe-a?1d, 9SSeS are scrubbed from the exhaust gas, the scrubber
P V bec°me acid1c' Caustic S0l"tion can be added to the
"«"""*. the solution. The pH is monitored using a
e1ectrode !s placed into a sump or a pipe through which
M1QS!V10WS\ The output frora the PH meter can be used ?o
control^ ?Lt5? SCrJbber ^'qU°r auto^tically by operating a valve
controls the flow of caustic solution to the scrubber liquor.
5-17
-------
Retroreriector
a.wmblv
Blower
Blower
Figure 5-9. Typical transmissometer installation for measuring opacity. 2
-------
REVIEW EXERCISE
1.
2.
8.
10.
List five incinerator operating
parameters that may be either controlled
or monitored.
List three wet scrubber operating
parameters that may be either controlled
or monitored.
3. When a control parameter such as tempera-
ture is used to adjust an operating func-
tion (such as an auxiliary burner),
often are used to determine when
the function is activated.
4. Thermocouples are used to monitor .
5. Thermocouples usually are located at the
of each combustion chamber and
upstream of the air pollution control
device.
6. Pressure drop is usually measured with
a gauge.
7. Oxygen monitors usually are located at
the exit to the combustion
chamber or in the ductwork of the
The two basic types of oxygen and CO
monitors used are called in situ and
9. Typically, CO monitors are part of the
automatic process control system. True
or False?
Opacity monitors are used as indicators
of proper operation and are not part of
the automatic control system. True or
False?
1. Temperature, draft,
oxygen concen-
tration, carbon
monoxide concentra-
tion, opacity,
charge rate
2. Pressure and pres-
sure drop, scrubber
liquid flow rate,
scrubber liquid pH,
temperature of inlet
gas
5. setpoints
4. temperature
5. exit
6. differential
pressure
7. secondary,
stack
8. extractive
9. False
10. True
5-19
-------
REFERENCES FOR SESSION 5
- ?Peratjon-. ^tenance, and Parts Manual for the
Incinerator. Publication No. CBK6826. September 1988.
2. Jahnke, J. APTI Course SI:476A, Transmissometer Systems Operation
and Maintenance, an Advanced Course. EPA 450/2-84-004 U S
Environmental Protection Agency, Research Triangle Park, N.'c
September 1984. p. 6-9.
3. Code of Federal Regulations, Title 40 Part 60 (40 CFR 60)
Appendix B, Performance Specification 1. Specifications and Test
Procedures for Opacity Continuous Emission Monitoring Systems in
Stationary Sources. jra«.«n*
4. U. S. Environmental Protection Agency. Continuous Air Pollution
Source Monitoring Systems Handbook. EPA 625/6-79-005. June 1979.
5. Amends Incinerators. Operation and Maintenance Manual for Models
751B, 1121B, and 2151B. January 1985.
6* u^1?1^6 C^st1on Products. Inc. Equipment Operating Manual for
u
Model No. 480E.
«°5ooZ,ink Company* standard Instruction Manual: John Zink/Comtro
A-22G General Incinerator and One-Half Cubic Yard Loader.
8* ^S1?1!!6 C°mbust1on Products, Inc. Equipment Operating Manual for
Model No. 2000TES.
9. Engineering Manual With Operation and Maintenance Instructions.
Anderson 2000, Inc. Peachtree City, Georgia. Undated.
10. Joseph, J. and D. Beach 1 er. - APTI Course SI:412C, Wet Scrubber Plan
Review - Self Instructional Guidebook. EPA 450/2-82-020 U S
Environmental Protection Agency. March 1984.
11. U. S. Environmental Protection Agency. Wet Scrubber Inspection and
Evaluation Manual. EPA 340/1-83-022. (NTIS PB 85-149375)
September 1983. *
12. U. S. Environmental Protection Agency. Fabric Filter Inspection and
Evaluation Manual. EPA 340/1-84-002. (NTIS PB 86-237716)
February 1984.
13. Beachler, D.S. APTI Course SI:412, Baghouse Plan Review. U. S.
Environmental Protection Agency. EPA-450/2-82-005. April 1982.
14. U. S. Environmental Protection Agency. Operation and Maintenance
Manual for Fabric Filters. EPA 625/1-86/020. June 1986.
5-20
-------
Protection Agency,
5-21
-------
-------
SESSION 6.
INCINERATOR OPERATION
-------
SESSION 6. INCINERATOR OPERATION
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 6-1
INTRODUCTION 6-1
WASTE HANDLING 6-2
Sturdy Containers !!!!!!!!!!!!! 6-2
Minimizing Waste Handling !!!!!!.'!!!! 6-3
Proper Operation of Waste Charging System !!.!!!..!. 6-3
Secure Storage '.'.'" 6-3
Do's and Don'ts of Waste Handling .*.".*.".*.*.".*.*.'.'.'.".'." 6-3
KEY OPERATING PARAMETERS 6-4
Key Operating Parameters for Controlled-Air Incinerators!.*...... 6-4
Key Operating Parameters for Multiple-Chamber Incinerators, 6-8
OPERATION OF CONTROLLED-AIR INCINERATORS 6-10
Proper Waste Charging Procedures ,....!! 6-10
Controlling and Monitoring Key Operating Parameters ,....!! 6-12
Other Parameters to-Monitor 6-18
Summary of Control and Monitoring Techniques for
Control 1 ed-Air Incinerators 6-19
Proper Ash Handling Procedures ..]" 6-23
Startup and Shutdown Procedures .'.'.'.'. 6-24
Do's and Don'ts for Operating a Controlled-Air Incinerator .. 6-25
OPERATION OF MULTIPLE-CHAMBER INCINERATORS 6-26
Introduction 6-26
Proper Waste Charging Procedures '.',[ 6-26
Controlling and Monitoring Key Operating Parameters 6-30
Summary of Control and Monitoring Techniques for Multiple-
Chamber Inci nerators 6-34
Proper Ash Handling Procedures '.[[ 6-34
Startup and Shutdown Procedures 6-35
Do's and Oon'ts for Operating a Multiple-Chamber Incinerator 6-36
REFERENCES FOR SESSION 6 6-40
-------
LIST OF FIGURES
Page
Figure 6-1. Example combustion chamber temperature trends-
moderate volatile content waste.. , 1C
0-15
Figure 6-2a. Proper and improper burner flame patterns 6_20
Figure 6-2b. Proper and improper burner flame patterns 6.21
Figure 6-2c. Proper and improper burner flame patterns 6-22
Figure 6-3. Improper charge procedures: stuffing and burning... 6-28
Figure 6-4. Proper and improper charging: waste bed
distribution
6-29
LIST OF TABLES
3PERATING PARAMETERS AND RECOMMENDED
RANGE: CONTROLLED-AIR INCINERATOR. ...." 6.5
TABLE 6-2. KEY INCINERATOR OPERATING PARAMETERS AND RFTOMMFKinpn
OPERATING RANGE: MULTIPLE-CHAMBER INCINERATOR . . 6.g
-------
-------
SESSION 6.
INCINERATOR OPERATION
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with:
• Proper waste handling procedures;
• Proper waste charging procedures;
• Key operating parameters for the incinerator and how they can be
monitored and controlled;
• Proper ash removal and handling procedures; and
• Special actions required and possible problems with startup and
shutdown of the incinerator.
OBJECTIVES
Upon completing this session, you should be able to:
1. Recognize the do's and don'ts of waste handling and charging-
2. Identify the key operating parameters for multiple-chamber and
controlled-air incinerators;
3. State the operating range that is considered acceptable for each
key operating parameter;
4. Describe how to monitor each key operating parameter;
5. List the special actions required for startup and shutdown of the
incinerator; and
6. Recognize the do's and don'ts of ash removal and handling.
INTRODUCTION
Many types of incinerators are used for the incineration of medical
wastes. The capacity of the incinerators varies tremendously because each
incinerator model is designed differently; design criteria, operating
parameters, and operating procedures will vary. The type of control
system and the degree of automatic control and monitoring used with a
specific incinerator also will vary.
As a result, this course cannot instruct you on how to operate your
specific incinerator and is not intended to do so. Specific onsite
training from the manufacturer of your incinerator, or a qualified
consultant, is recommended. The objective of this session is to provide
y°u Wlth a basic understanding of the most important operating parameters
and how you can monitor and control them. With a basic understanding of
the key parameters, you should be able to better understand the operation
of your system. HCKH.IWM
6-1
-------
The operator is in control of many of the factors that have an impact
on the performance of the incinerator including:
• Startup and shutdown;
• Waste charging procedures;
• Monitoring and adjusting operating parameters; and
• Ash handling.
The primary concern is to assure that the incinerator is operated in
a manner so that:
• Infectious materials in the waste are rendered harmless; and
• Air pollution emissions are minimized.
In this session we will:
Discuss proper waste handling procedures;
Identify key operating parameters;
Identify recommended operating ranges for the key parameters;
Discuss operation of controlled-air incinerators; and
Discuss operation of multiple-chamber incinerators.
WASTE HANDLING
Typically, you will be responsible for handling the waste prior to
charging it to the incinerator. The primary concern with infectious waste
handling is to avoid exposure of yourself and others to pathogens and
avoid injury from sharp objects such as needles and broken glass. Proper
procedures dictate that:
• Sturdy containers (including bags) are used;
• Waste handling is minimized;
• Mechanical waste charging devices are properly operated and
maintained; and
• The waste storage area is secure and away from public traffic.
STURDY CONTAINERS
As an operator, you probably do not have control over the type of
waste containers that are used. However, if breakage and spillage is a
problem, you have an obligation to notify hospital management. Several
things can be done if bag breakage is a problem. These include:
• Using stronger bags;
• Double bagging;
• Loading less material into each bag;
• Placing the bags in rigid containers such as cardboard boxes or
barrels which can be incinerated.
6-2
-------
MINIMIZING WASTE HANDLING
As an operator, you have some control over the handling of the
waste. The less you handle the waste the less chance there is of breakina
bags or injuring yourself. You should think of ways you can minimize
handling of the waste.
One example of how waste handling can be minimized is the use of
rolling carts to transport and store the waste before charging. Once the
red bags are placed in the carts and transported to the incinerator, the
bags should not need to be handled again until the bags are loaded
directly from the cart into the incinerator charging system. It does not
make sense to unload the bags from the cart and pile them on the ground
and then have to pick them up again to load them into the incinerator.
PROPER OPERATION OF HASTE CHARGING SYSTEM
To minimize breaking and spilling bags, the mechanical charqinq
system should be properly operated.
Hopper/Ram Systems. Do not overfill the hopper by jamming waste into
it. Do not force the hopper door closed.
Automatic Cart Dump Systems. Do not overfill the carts.
SECURE STORAGE
The waste should be stored in a safe and secure way—even if stored
only for a short period of time. The following are guidelines:
• The waste storage area should be out of the way of normal hosoital
pedestrian traffic.
• The area should be secure from public access.
• The storage area or containers should be secure from rodents which
can contract and transmit disease.
An example of poor waste storage is throwing the bags in a piTe on
the loading dock adjacent to the hospital parking lot. An example of
better waste storage is to leave the bags in transport carts inside an
area protected by a chainlink fence and with limited access. An example
of even better waste storage is to leave the bags in transport carts
inside a well ventilated building which houses the incinerator charging
system. Some State regulations require that infectious wastes be stored
under refrigeration if they are not to be incinerated within a specified
time period (e.g., 24 hours).
DO'S AND DON'TS OF WASTE HANDLING
DO:
• Minimize your handling of the waste.
• Report repeated problems with bag breakage/spillage to hosoital
administrators.
6-3
-------
• Assure that the waste to be charged is safely stored if it will
not be immediately charged.
DON'T:
• Throw bags around and cause the bags to break and spill.
• Misuse mechanical charging systems and cause the bags to break and
spill.
KEY OPERATING PARAMETERS
In this section, the key operating parameters for controlled-air and
multiple-chamber incinerators are identified, and operating ranges
consistent with "good operating practice" for the key parameters are
presented. The rationales for the operating ranges also are presented.
However, incinerator designs differ, and operation of a particular
incinerator outside the recommended ranges may be appropriate. The
objective is to operate the incinerator in such a manner to achieve
complete combustion, sterilize the ash, and minimize air pollutants.
Furthermore, in many cases, specific operating limits are established by
regulatory agencies; these limits may differ from the recommended
operating ranges presented here. Obviously, the incinerator should be
operated within the regulatory limits.
First, the key operating parameters for controlled-air incinerators
are presented and discussed. Then the operating parameters for multiple-
chamber incinerators are presented and discussed.
KEY OPERATING PARAMETERS FOR CONTROLLED-AIR INCINERATORS
Table 6-1 summarizes the key operating parameters and recommended
operating ranges for the typical controlled-air incinerator.
The key operating parameters are:
Primary chamber temperature;
Secondary chamber temperature;
Charging rate;
Primary chamber combustion air level;
Total combustion air level;
Combustion gas oxygen concentration; and
Primary combustion chamber draft.
Each of these parameters is briefly discussed below.
Primary and Secondary Combustion Chamber Temperatures. The key
parameter most likely to be monitored by the operator is the temperature
of both chambers. The temperature ranges for the two chambers are
different because the functions of the two chambers are different.
Both upper and lower limits on the temperature range for each chamber
are necessary.
6-4
-------
CTi
tn
Primary chamber temperature, 'f
Combustion (secondary) chamber
temperature, "F
Charging rate, Ib/h
Primary chamber combustion air
(percent of stoleniometric)
Total combustion air
(percent excess air)
Combustion gas oxygen
concentration, percent
Primary chamber draft, in w.c.
Burndown period, h
II
Batch feed
1000' to 1800"
1800' to 2200'
Fill chamber once at beginnina
of cycle
30 to 80
HO to 200
12 to 14
-0.05 to -0.1
2 to 5
Incinerator type
intermittent feed "
1000' to 1800°
1800' to 2200"
10 to 25 percent of rated
capacity at 5 to 15 mln
intervals
30 to 80
140 to 200
12 to 14
-0.05 to -0.1
2 to 5
Continuous duty
1000° to 1800°
1800' to 2200'
10 to 25 percent of rated
capacity at 5 to 15 mln
intervals
30 to 80
140 to 200
12 to 14
-0.05 to -0.1
Not appl (cable
-------
• The temperature is maintained above the lower limit to assure
complete combustion of organic compounds and destruction of
pathogens.
• The temperature is maintained below the upper limit to prevent
damage to the incinerator refractory and slagging of the ash.
The recommended operating ranges which are considered to be good operating
practice are as follows:
• Primary chamber lower limit: Greater than 1000°F (540°C).
The chamber must be maintained at a temperature sufficient to
maintain combustion, combust the fixed carbon in the waste, and sterilize
the remaining ash. For continuous-duty, controlled-air incinerators, a
minimum temperature of 1000°F (540°C) also is recommended. However a
higher temperature such as 1400°F (760°C) may be needed to assure
combustion of the fixed carbon since the retention time of the ash in the
incinerator may be less than for batch and intermittent-duty
incinerators. The temperature necessary to achieve an acceptable ash
burnout quality should be used.
• Primary chamber upper limit: less than 1800°F (980°C).
The primary chamber must be maintained below a temperature where
slagging of the waste occurs and damage to the refractory may occur.
It should be cautioned that a higher primary chamber temperature is
not necessarily always better (e.g., 1700°F is not necessarily better than
1200°F). Many factors must be considered, including waste charac-
teristics. One manufacturer reports that based on their experience, the
volatilization rate of plastics can be significantly affected by the
temperature in the primary chamber (i.e., more rapid volatilization at
1800°F than 1100°F). Based on their experience, operating the primary
chamber at tue lower end of the recommended range helps to minimize rapid
increases in flue gas volume when highly volatile wastes are charged and
results in improved operation because the secondary chamber is not
overloaded with volatile gases.
• Secondary chamber lower limit: greater than 1800°F (980°C).
The temperature of the secondary chamber must be maintained at a high
enough level to assure complete combustion of all organic compounds. The
exact temperature required for this is dependent upon many things,
including the compound, the oxygen level, how well the gases are mixed
with the oxygen, and how long they are in the combustion chamber. A lower
limit of 1800°F is recommended.
• Secondary chamber upper limit: less than 2200°F (12QO°C).
The temperature of the secondary chamber must be maintained below a
level which causes damage to the refractory; this level usually is around
2200°F (1200°C) for sustained operation, but is dependent on the type
refractory used.
6-6
-------
NOTE: Many regulatory agencies have established specific lower
temperature limits for each combustion chamber. These im ?s may
differ from the recommended limits presented in Table 6-
Therefore, if your permit establishes a lower level temperature
limit, you must operate above this limit. temperature
Typical regulatory limits are:
lm OW)7 Chamber temPerature"™st operate at greater than HOOT
2' (870°^^ Chamber temperature"must °Perate at greater than 1600°F
co
Steady state operating conditions are approached as:
' 2Jt"SElSrt!1t1Cn (he" C°ntent' "I°1sture-
• The charge loads decrease in size; and
• The charges are made more frequently.
V0lume may be "™ *>T,U)1. than
tsr^;?s%r^err ' -
he,p assure that sufficient
The«OXy9en 'eve1 fn the stack 9" 1s an 'ndicator of the excess
o 22s s?ssti!s,nrsrr of 12 to 14 percent nu^ '<^
6-7
-------
negative pressure can cause excessive air infiltration through leaks into
the incinerator. A typical range for the draft in the primary chamber is
-0.05 to -0.10 inch of water column (in. w.c.) (-0.012 to -0.025 kilo-
pascals [kPa]).
KEY OPERATING PARAMETERS FOR MULTIPLE-CHAMBER INCINERATORS
Table 6-2 summarizes the key operating parameters for the typical
multiple-chamber incinerator.
The key operating parameters are:
Primary chamber temperature;
Secondary chamber temperature;
Charging rate;
Ignition chamber combustion air level (percent excess air);
Total combustion air level (percent excess air);
Combustion gas oxygen concentration; and
Primary and secondary combustion chamber pressure.
Each of these parameters is briefly discussed below. Many of these
operating parameters have already been discussed in detail for controlled-
air incinerators. Therefore, the discussion is abbreviated here.
Primary And Secondary Combustion Chamber Temperature.
The key parameter most likely to be monitored by the operator of a
multiple-chamber incinerator is the temperature of each chamber. The
temperature is maintained above the recommended lower limit to assure
complete combustion of organic compounds and sterilization of the ash.
The temperature is maintained below the upper limit to prevent waste
slagging and damage to the incinerator refractory. The recommended ranges
are:
• Primary chamber—10008 to 1400°F (540° to 760°C)
• Secondary chamber~1800° to 2200°F (980° to 1200°C)
As noted in Table 6-2, a higher temperature is recommended in the
primary chamber when incinerating pathological wastes. The higher
temperature is recommended to facilitate the burndown of the waste.
Many regulatory agencies have established lower limits for each
combustion chamber. If your operating permit establishes a lower
temperature limit, you must operate the incinerator above this limit.
Charging Rate. The charging rate and procedures used are very
important for operation of a multiple-chamber incinerator.
Note that charging rates for general refuse/red bag and pathological
wastes are presented differently in Table 6-2 because of their different
waste characteristics. For general refuse/red bag waste, it is important
to make frequent, small charges to avoid large surges of volatile
6-8
-------
TABLE 6-2 KEY'INCINERATOR OPERATING PARAMETERS AND RECOMMENDED
OPERATING RANGE: MULTIPLE-CHAMBER INCINERATOR
Parameter
Ignition chamber temperature, °F
Combustion (secondary) chamber
temperature, °F
Charging rate
Ignition chamber combustion air
(percent excess air)
Total combustion air (percent
excess air)
.Combustion gas oxygen concentration,
percent
General refuse
1600 to 1800 1000 to 1400
1800 to 2200 1800 to 2200
Single layer
on hearth
80
120 to 200
10 to 14
10 to 25% of
rated capacity
at 5- to 15-min
intervals
150
250 to 300
15 to 16
Ignition chamber draft, in. w.c.
-0.05 to -0.1 -0.05 to -0.1
6-9
-------
combustible gases that can exceed the capacity of the combustion air
supplied in the primary and secondary chambers. Pathological waste must
be exposed to a direct flame to achieve combustion.
Primary And Secondary Chamber Combustion Air Levels And Combustion
Gas Oxygen Concentration. The primary chamber for a multiple-chamber
incinerator is typically maintained at an excess air level of about 200
percent. A multiple-chamber incinerator is operated at an overall excess
air level of about 250 to 300 percent. This results in combustion qas
oxygen levels in the 15 to 16 percent range. Multiple-cnamber
incinerators burning pathological wastes typically are operated at lower
excess air levels than incinerators burning general refuse. Less excess
air is used because pathological waste contains less volatiles and the
heat input comes primarily from auxiliary burners.
Primary Chamber Draft. A negative pressure must be maintained in the
combustion chambers. Sufficient draft must be maintained to move the
combustion gases through the incinerator. Too much draft will cause
excessive entrapment of particulate matter from the primary chamber,
which will be emitted as an air pollutant. Excessive draft also will
increase the air in-leakage to the incinerator which increases the excess
air level. The typical range for the primary chamber draft is -0.05 to
-0.10 in. w.c. (-0.012 to -0.025 kPa).
OPERATION OF CONTROLLED-AIR INCINERATORS
This section discusses the operation of controlled-air incinerators
including:
• Proper waste charging;
• How to monitor and control the key operating parameters;
• Proper ash handling; and
• Starting up and shutting down the incinerator.
PROPER WASTE CHARGING PROCEDURES
Proper waste charging is probably the most important procedure for
the operator. Remember that the heat input rate to an incinerator is very
important because the incinerator is sized for a particular heat release
rate:
• If the release rate is too low, the incinerator will not operate
efficiently and excessive auxiliary fuel will be required.
• If the heat release rate is too high, incomplete combustion is
likely to occur causing pollution.
As an operator, you should be aware that the heat content of wastes
may vary and therefore you may need to vary the charging procedures—that
is, you may need to charge more or less waste.
Special care should be taken to avoid overcharging the incinerator
(beyond its intended use) with pathological wastes (animal carcasses and
6-10
-------
Evn?w^CaUS?T0f.the h1gh moisture content a"* 1°* heat value of
TIE?,. (InClneration of ^9e quantities of thesfw^el ?s
jon 3, the operating mode of controlled-air incinerators
• Single batch;
• Intermittent duty; or
• Continuous duty.
was
USUa'ly sma" ' »" -re charged
The incinerator is charged cold.
a
cycle rather than relying on a sinale batch rhLnl rouf^t he °Peratln9
automated charging systems are used drge' Elther manual or
pHnc1ples 3ppl* for ^rln intermittent-duty
Uh a C0nstant h-t input to
• Frequent, smaller charges are more desirable than one big charge.
6-11
-------
• Overcharging (feeding too much waste in a charge) can cause
excessive emissions because of rapid volatilization of organic
compounds that overload the secondary chamber.
• Feeding too little waste results in inadequate heat input and
excessive auxiliary fuel use.
• A recommended charging frequency is 10 to 25 percent of the rated
capacity (Ib/h) at 5 to 15 minute intervals.
• Another rule of thumb is to recharge the incinerator after the
previous charge has been reduced by 50 to 70 percent in volume fas
observed through a viewport).
• Charging volume and frequency will vary with waste composition and
the incinerator design. Differences in charging procedures are
appropriate for small manually fed units and large mechanically
fed units. For large systems using mechanical charging, frequent
charges will not interrupt incinerator operation because the
mechanical system limits entry of excess air. Frequent, smaller
charges are desirable. For smaller manually fed units, each time
the door is opened, excess air enters and disrupts combustion
Also, opening the door creates a potential safety hazard Less
frequent charging is desirable. However, the charges should not
be so large as to overload the incinerator.
• After the last charge of the day is completed, the incinerator is
set to initiate burndown. The limiting factor on how long the
incinerator can be operated without shutting down is how quickly
ash builds up on the hearth. Typically, the operating period
during which the incinerator is charged with waste is limited to
12 to 14 hours.
Continuous-duty incinerators. Continuous-duty incinerators typically
are large units equipped with mechanical feed systems.
The mechanical feed system often is automatically operated so that
the charge is fed on a timed sequence. Proper charging involves:
• Frequent charges of 10 to 25 percent of rated capacity (Ib/h)
every 5 to 15 minutes.
• Charging frequency may need to be adjusted to accommodate major
changes in waste heat value.
CONTROLLING AND MONITORING KEY OPERATING PARAMETERS
The specific controls and monitors for each incinerator will be
different. Some incinerators will have mostly manual controls and few
monitors. Other incinerators will have highly automated control systems
with many monitors to assist the operator. In this section, we will
review some basic procedures the operator can follow for controlling and
monitoring key operating parameters. How much control you actually have
over the operation of your incinerator depends on the specific design and
installation of the incinerator.
6-12
-------
The operating parameters which we win discuss include:
• Charging rate;
• Primary and secondary chamber temperatures-
• Combustion air levels; and
• Combustion chamber draft.
Charge Rate. The charge rate--or heat input rate-is critical i-n
rni°PeTat1(?n 3nd 1! °ne Parameter °ver which the operator has direct
control. The incinerator must be operated with a charge rate consistent
Z ^r ^^
rdte Ca" ** easily
"°n1t°r
The operator can monitor the charge rate in several ways:
Recording the amount and the time of each charge-
Noting the source and type of waste* '
Observing trends in the primary and'secondary temperatures
bed ln the "
time and amount °f
. 1s Mde
Monitoring charging In this way should provide sufficient Infomatlcn tn
£=,;:far^^
cause of black smoke, it is only necessary to reduce the number
n whether
6-13
-------
It is expected that the temperatures will rise and fall in a cycle
after each charge. However, major swings (for example, outside the
recommended operating ranges) may be an indication of a need to adjust
charging procedures.
You should look for:
• Primary chamber temperature drop—if the primary chamber
temperature falls below the desired low temperature setpoint and
the auxiliary fuel burner is activated, the chamber is low on fuel
and is overdue for a charge. (This assumes that the automatic
combustion air control system is properly operating and that
proper air has been provided to the primary chamber). Note: When
very wet or low Btu waste is added to the primary chamber, a drop
in temperature is expected. Adding more waste will further
decrease the temperature.
• Secondary chamber temperature increase—if the secondary
temperature begins to rise above the desired high temperature
setpoint, the chamber may be receiving more fuel—in the form of
combustion gases from the primary chamber—than the automatic air
and burner control system can handle. Assuming the primary
chamber air control system is properly operating, this situation
indicates excess volatile emissions from a charge; i.e., the
previous charge was too large or was too soon after the last
charge.
Figure 6-1 depicts a temperature record for a controlled-air
incinerator charged with a waste containing a significant volatile
content. The impact of the charge on the temperatures can be seen.
Primary and secondary temperatures as key parameters are further discussed
in the next section.
3. Observing the waste bed. If view ports are available in the
primary chamber, you can observe the waste bed. If the pile of unburned
waste (other than normal ash buildup) inside the chamber is rapidly and
steadily increasing in size, then the amount charged is greater than the
amount which can be consumed in the same period of time. On the other
hand, if all the waste is consumed well in advance of the next charge, it
may be desirable to increase the charge size.
4. Observing ash quality. If all the combustible waste is not
burned, it may be because the charge rate is too high and not enough time
has been provided for complete combustion. Another reason for poor ash
quality is insufficient underfire air. The term "burnout" is used to
describe the amount of combustible material left in the ash. If all the
waste is burned and no combustible material is left in the ash, the
burnout is 100 percent. If only half the combustible waste is burned and
one-half of the remaining ash is combustible, the burnout is 50 percent;
this level of burnout is not good.
6-14
-------
-Secondary Chamber
Temperature
•Primary
Chamber
Temperature
Burndown
TEMPERATURE TREND
Figure 6-1. Example combustion chamber temperature trends-
high volatile content waste.1
6-15
-------
Control of the charge rate. The charge rate can be controlled by
you. The rate can be controlled by either charging less waste with each
load or by charging less frequently. For example: if an incinerator has
an automatic hopper/ram charging system which is automatically controlled
to charge one hopper every 10 minutes, the operator can reduce the
charging rate simply by not filling the hopper to the top. The other
approach would be to change the automatic timer to charge less frequently;
for example, every 15 minutes instead of every 10 minutes. If the charge
rate is to be increased for a system using a hopper/ram assembly, the
frequency of charges would need to be increased (every 7 minutes, for
example) because you should not overfill a hopper.
Primary and Secondary Chamber Temperatures.
Monitoring temperatures. You use temperature gauges to monitor the
primary and secondary chamber temperatures. All incinerators should have
a temperature gauge and, preferably, a temperature recorder. A recorder
will assist you in seeing temperature trends.
Controlling temperatures. You can control temperature in three ways:
• Adjusting the charging rate;
• Adjusting the combustion air level; and
• Adjusting the auxiliary burner setpoints.
The importance of charging rate already has been discussed. Adding
additional waste will generally increase the temperature; in a controlled-
air incinerator, the automatic air control system will act to limit the
temperature increase to the desired temperature setpoint. Note: if the
fuel has a low heat content, such as pathological wastes or very wet
waste, the temperature can actually decrease when a charge is added.
For a controlled-air unit, controlling the combustion air affects the
temperature. Adjusting the combustion air is the primary control
mechanism used, other than adjusting the charge rate. Increasing the air
in the primary chamber increases the primary chamber temperature and
increasing the air in the secondary chamber decreases the secondary
chamber temperature. Usually, the automatic control system on a
controlled-air unit will control the air levels. The automatic control
system's operation will be based on:
• A clock timer sequence which operates in conjunction with each
batch charge; or
• The temperature output from the thermocouples; or
• Some combination of the above two.
Actual adjustments to air damper settings or time/temperature setpoints
normally are not made by you unless problems are persistent. Only
properly trained operators should make damper adjustments on an automatic
control system.
6-16
-------
The final temperature control available to you is use of the
auxiliary burners in the primary and secondary chambers. Again, these
burners normally are automatically controlled; the burner is activated bv
a temperature setpoint. Only properly trained operators should adjust
setpoints. aujuau
Primary Chamber and Secondary Chamber Combustion Air Levels And Stark
Gas Oxygen Level. " •
Monitoring combustion air levels. Two means of monitorinq air levels
which are available to you are:
• An oxygen monitoring system; and
• Visual observations (indirect indicator).
The only way to actually measure the combustion excess air level is
to use an oxygen monitor. Some incinerators have an oxygen monitor
installed in the stack to monitor the overall excess air level. When such
a monitor is available, you should assure that the combustion gas oxyqen
remains within the desired range. «*yyen
Visual observation within the combustion chambers (through sealed
glass observation ports) and of the stack gas will assist the operator in
determining whether air levels may be incorrect. You should look for the
following:
• Primary Chamber—The primary chamber is supposed to operate with
deficient oxygen. The waste bed should be burning with a dark red
color, and smoke will likely be present. If roaring bright yellow
or orange flames are present, too much air is available. The
problem may be air infiltration from leaks or improper combustion
air settings.
• Secondary Combustion Chamber—The secondary burner flame should be
burning with a bright yellow/orange flame and should not be
smoking. A smoking flame indicates too little burner air
• Stack Gas--The stack gas should be clean. Black smoke indicates
incomplete combustion caused by insufficient air in the secondary
chamber. (This situation is discussed in Session 8).
Control of Combustion Air. The combustion air levels are controlled
by adjusting the combustion air dampers. Depending upon the control
system, you may or may not have direct control of the air dampers The
air dampers are usually automatically controlled to maintain the desired
combustion chamber temperatures. If you suspect persistent problems with
combustion air levels, the damper settings should be checked and adjusted
by a trained/qualified technician. aajustea
In some cases, a manual "emergency" override for automatically
controlled systems may be present on the control panel for use when black
smoke at the stack indicates incomplete combustion. Such an override will
fully open the secondary air damper to allow maximum air while fully
closing the damper to the primary chamber to decrease combustion-
typical ly, the override also will shut off the secondary burner.'
6-17
-------
Incinerator Draft. The draft in the primary chamber must be
maintained within the desired operating range. If the draft is too hiqh
entrainment of participate matter may occur, or air infiltrat ™ ?h™ 22'
leaks may be excessive. If the draft is too L! the c amber Z reach a
positive pressure, which is not desirable because smoke arS hot^awJ
might puff from the chamber door seals. A negativ^ressure in the
incinerator is needed to prevent fugitive emissions.
Monitoring incinerator draft. A draft gauge is required to measure
6 incinerator chamber' *™ Incinerator may oV^not
Control of incinerator draft. For natural draft systems, the draft
may be controlled by a motorized barometric damper or stack damper or it
may be uncontro ed. Depending upon your system, these dampers may be
manually controlled or may have an automatic control to maintain a preset
For systems using an induced draft fan, a damper at the fan inlet or
outlet is usually used to control the fan suction. Again, the daiSer mJJ
be controlled manually or automatically. uomper may
OTHER PARAMETERS TO MONITOR
Other parameters you should monitor include:
• Stack opacity;
• Stack gas carbon monoxide; and
• Burner flame pattern.
Stack Gas Opacity. Stack gas opacity provides an indirect
measurement of particulate matter concentration in the stack qas As
part icu late matter increases so does opacity.
You should make a habit of observing the stack emissions. If hiqh
opacity emissions occur, proper operation of the equipment should be
checked and operating procedures should be changed, if necessary
Session 8 further discusses how opacity can be used to identify combustion
problems and some possible operating changes to correct the problems.
If your incinerator is equipped with a transmissometer (continuous
monitor for opacity) you should learn the acceptable opacity range and
frequently check the instrument data to assure that the incinerator is
operating within the acceptable range; pay attention to the "high opacity
alarm" when it goes off. a K •*
Combustion Gas Carbon Monoxide. Carbon monoxide gas (CO) is formed
during incomplete combustion. Excessive levels indicate that a poor
combustion condition exists. Levels greater than 100 ppm are usually
considered excessive. Your State may specifically regulate the level of
6-18
-------
The CO level of the combustion gas can be monitored by an
instrument. If your incinerator continuously monitors CO, you should
routinely check the levels to assure they stay within the acceptable
range. If they do not, changes in your charging procedures or adjustments
to combustion air levels are probably necessary. If no CO instrument is
installed, you cannot determine CO levels.
Burner Flame Pattern. If sealed observation ports are available, you
should check the burner flame pattern daily. The burner flame should:
• Be bright yellow/orange;
• Not smoke;
• Not move back and forth abruptly; and
• Not hit the refractory walls.
Figures 6-2a, 6-2b, and 6-2c schematically show proper and improper
flame patterns. If you suspect a burner problem, report the problem to
the maintenance department.
SUWARY OF CONTROL AND MONITORING TECHNIQUES FOR CONTROLLED-ATR
INCINERATORS "~~ * i±EH_«J£
The control and monitoring of a controlled-air incinerator is
complex. Five of the key operating parameters that are very interrelated
are:
• Charge rate;
• Primary chamber temperature;
• Secondary chamber temperature;
• Primary chamber combustion air level; and
• Secondary chamber combustion air level.
A typical controlled-air incinerator system will have some type of
automatic control system which controls both the temperature and amount of
combustion air to both chambers. The system monitors the chamber
temperatures and controls the combustion air levels and auxiliary burners
to maintain the desired setpoints. For the automatic control system to
operate properly, the incinerator must be charged with an amount of waste
consistent with the incinerator's design capacity.
The charge rate to the incinerator is the single most important
parameter that you can control. The operator monitors combustion chamber
temperatures and temperature trends to evaluate whether the charge rate is
appropriate. If an oxygen monitor is available, the stack gas oxygen
level is monitored to confirm that combustion air levels are consistent
with good operating practice.
6-19
-------
Proper Flame
Pattern
Figure 6-2a. Proper flame pattern.22
6-20
-------
Detached Flame; Too
Much Burner Air
Smoking Flame;
Not Enough Air
Figure 6-2b. Improper burner air.22
6-21
-------
Figure 6-2c. Flame impingement.22
6-22
-------
ngai^^^
'
PROPER ASH HANDLING PRQEFniiPF?
-
-,:;«
or knocking burner nozz,e aailes or the™,coup,e
1nt° a nonc™bu«1'>^ container such as ,etal, not
(^cording to
Being on the lookout for jams in conveyor systems
53 ES- "
with
6-23
-------
• Inspecting ash quality, noting problems, and determining whether
operating changes are required.
STARTUP AND SHUTDOWN PROCEDURES
Startup and shutdown of an incinerator typically requires special
steps to be taken. Specific manufacturer's instructions should be
followed. Some general recommended procedures are listed below.
Single-batch feed incinerators.
Startup:
• Remove the ash from the previous cycle;
• Charge the incinerator; do not overcharge;
• Seal the charge door;
• Preheat the secondary combustion chamber to a predetermined
temperature (1800°F [980°C] is recommended);
The manufacturer should be consulted regarding proper preheat
procedures; improper preheat can result in refractory damage.
Note: If the incinerator is overloaded and the waste in the
primary chamber enters the air passageway to the secondary
chamber, the waste may self-ignite during the preheat period.
This situation should be avoided; and
• Activate the primary chamber combustion air and burner to ignite
the waste.
Shutdown:
• After the waste burns down and all volatiles have been released,
the final burndown period is initiated.
— Increase the primary combustion air level to improve
combustion of the fixed carbon.
-- Maintain the temperature in the primary chamber at a minimum
temperature using the auxiliary burner for a predetermined
length of time to assure that the fixed carbon is combusted.
~ When the burndown period is complete, as indicated by
maintaining the preset temperature in the primary chamber for
a preset period of time, the cooldown period is Initiated.
~ Shut down the primary and secondary burners.
~ Keep the combustion blowers operating to assist in cooldown.
Intermittent-Duty Incinerators. The general procedures for startup
and shutdown of an intermittent-duty incinerator are as follows.
Startup;
• Ignite the primary and secondary burners and preheat the
combustion chambers.
6-24
-------
• After the secondary temperature has reached a minimum predeter-
mined temperature (1800'F [980°C] is recommended), activate the
combustion air blowers. The manufacturer should be consulted
regarding proper preheat procedures; improper preheat can result
in refractory damage.
• Charge the incinerator.
Shutdown. After the last charge of the day, the incinerator is set
to initiate a burndown/cooldown procedure. Depending upon the inciner-
ator, this sequence will be manually or automatically activated and
controlled. The burndown/cooldown procedure is essentially the same as
the procedure discussed for the batch-type incinerator.
Continuous Duty Incinerators. The general startup and shutdown
procedures tor continuous-duty incinerators are: snutaown
, S^UP- The startup procedure is essentially the same as for
intermittent-duty incinerators. The combustion chambers should be
preheated before charging the first load of waste.
Shutdown. Shutdown of a continuous-duty incinerator involves
stopping the charging process and maintaining temperatures in the
combustion chamber until the remaining waste burns down to ash and is
finally discharged from the system in a normal manner.
Special Considerations.
Pa|h^Jp£icjlj^. if the waste being incinerated is pathological
waste or contains a large amount of pathological waste, it will be
necessary to leave the ignition burner on during the entire process. In
fact, incinerators intended for burning primarily pathological waste will
usually have additional burners in the primary chamber?
You should remember:
• To destroy pathological waste efficiently, the waste must be
directly exposed to the burner flame.
• Loading pathological waste into the incinerator in large piles
will result in inefficient combustion. A single layer of waste
should be placed onto the hearth.
• If large volumes of pathological waste are to be incinerated, an
incinerator specially designed for pathological waste should be
DO'S AND DON'TS FOR OPERATING A CONTRQLLED-AIR INCINERATOR
DO:
Preheat the secondary chamber before igniting the waste-
Pay careful attention to charging procedures and charging rates-
character Si?s- Pdy dttent1on t0 extreme differences in waste-
6-25
-------
• Monitor combustion chamber temperatures and learn to recognize
trends that are good and trends that indicate a problem-
• Routinely monitor stack gas opacity, especially after charging:
• Pay attention to the other monitors you may have at your facili
such as oxygen, CO, and opacity; ^"
• Make good use of viewports to visually check the combustion
chambers and learn to recognize problems;
• Pay attention to operation of your auxiliary burners; are they
properly cycling on and off? At the right time?
• Inspect the ash quality. If visual inspection indicates poor
burnout—large recognizable pieces of combustible waste such as
hospital scrubs—check your equipment and/or make changes to
operating procedures/conditions;
• Note problems that indicate the need for adjustment of automatic
control system dampers and setpoints—if you are not trained to
make adjustments, call maintenance;
• Handle and dispose of the bottom ash properly and carefully;
• Operate the primary burner(s) when burning pathological waste.
DON'T:
• Overcharge the incinerator; and
• Charge large amounts of pathological waste to the incinerator
unless it is designed for pathological waste.
OPERATION OF MULTIPLE-CHAMBER INCINERATORS
INTRODUCTION
Multiple-chamber incinerators may have a grate or a fixed (solid)
hearth in the primary chamber. Incinerators with grates are designed for
use with general refuse, and combustion of medical infectious wastes
containing significant quantities of fluids is not recommended in this
type incinerator.
Multiple-chamber incinerators designed specifically for burning
pathological wastes always have a solid hearth. Caution should be
exercised when burning general refuse/red bag wastes in an incinerator
designed specifically for pathological waste. Red bag wastes likely will
contain much more volatile combustible, material than pathological wastes
and will have a higher heat value (Btu/lb). Overcharging the incinerator
with red bag waste will result in excess emissions. The proper charging
rate for the waste being burned should be carefully determined by trained
personnel. Charging procedures consistent with the type of waste being
charged should be established.
PROPER WASTE CHARGING PROCEDURES
Most multiple-chamber incinerators used for hospital wastes are
designed for intermittent duty operation. Typically, the waste is charged
by hand to the incinerator through the open charging door or-by a
mechanical charging system such a hopper/ram.
6-26
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Remember that the heat input rate to an incinerator is a very
important parameter because the incinerator is designed for a specific
heat input rate. The heat input from the waste is determined by the
amount of waste and the heat content of that waste. Because the heat
content of red bag waste and pathological waste is so different, operation
of an incinerator when burning these two types of wastes is different
Proper charging procedures for both types of waste are discussed below.
Red Bag Waste. The heat content of red bag waste is variable
depending upon the contents of the bag. Proper operation dictates'that:
• Sufficient waste should be charged to the incinerator to sustain
the desired temperature without excessive use of the primary
burner; and
• To maintain the incinerator chamber below the upper temperature
limit and to prevent emissions, the charge rate should not exceed
the capacity of the incinerator at any time.
.Therefore, recommended charging procedures include:
• Use of frequent, small batches rather than one large batch. The
objective is to avoid causing a rapid release of volatile
compounds that exceeds the combustion capacity of the
incinerator. The frequency and size of each charge will be
determined by the incinerator you have and the type of waste. A
recommended procedure is to charge about 10 percent of the rated
capacity (Ib/h) every 15 minutes.
• Keeping a fairly consistent waste bed in the incinerator. The
incinerator should not be jammed full, nor should it be empty.
• Avoiding "stuffing and burning" in the incinerator; that is, do
not fill the incinerator chamber to full capacity, floor to
ceiling, ignite the waste, and allow the incinerator to operate
unattended. The proper charging of frequent, small batches versus
the improper "stuff and burn" charging approach is illustrated in
Figure 6-3.
• When recharging the incinerator:
— Make sure the primary burner is turned off.
-- The waste bed should be stoked, if necessary, and partially
burned waste from the previous charges should be pushed
towards the back of the hearth. The new waste charge should
be fed to the front end of the hearth (near the charge
door). This procedure allows good exposure of the partially
combusted waste to the overfire air and allows a good flame
from the waste bed to be maintained. On the other hand, if
cold, new waste is thrown on top of the existing waste bed, it
partially smothers the burning bed which can result in
increased emissions. These proper and improper recharqinq
procedures are shown in Figure 6-4.
. Pathological Waste. Pathological waste has a low heat content, hiqh
moisture content, and contains a low percentage of volatiles. The waste
must be exposed to the auxiliary burners to be combusted. The followina
charging procedures are recommended.
6-27
-------
"Stuff and Bum"
Frequent Small Charges
Figure 6-3. Proper and improper charge procedures,
6-28
-------
Ash Bed Stoked To Rear-
Load To Front
Partially Burned
Ash Smothered
Figure 6-4. Proper and improper charging: waste bed distribution.
6-29
-------
• The waste should be placed on the hearth in an even layer that
provides maximum exposure to the burner(s) flame(s). The waste
should not be deeply piled.
• Recharging the incinerator should not be done until considerable
reduction in volume (greater than 75 percent) of the previous
charge has occurred.
• When recharging the incinerator:
— Turn off the primary burner(s);
— Place the fresh charge in a layer on top of the ash bed to
provide maximum exposure to the burner flame(s); and
— Close the charge door before restarting the primary burner(s).
CONTROLLING AND MONITORING KEY OPERATING PARAMETERS
^ The specific controls and monitors for each multiple-chamber
incinerator will be different. Some incinerators have mostly manual
controls with few monitors. Some incinerators have more automated
controls and monitors to assist the operator.
In this section, we will review some basic steps you can take for
controlling and monitoring the key operating parameters. Specific details
of control and how much control you actually have over the operation of
your incinerator depends on the specific incinerator.
The operating parameters discussed below include:
• Charging rate;
• Primary and secondary combustion chamber temperatures-
• Combustion air levels; and
• Combustion chamber draft.
Charging Rate. The single most important operating parameter that
you can easily control is charging of the incinerator. The incinerator
must be operated with a charge rate consistent with its design capacity.
Monitoring the charging rate. The charge rate can be easily
monitored. It is not necessary to monitor the rate exactly—unless
required by regulation.
The operator can monitor the charging rate in several ways:
Recording the amount and the time of each charge;
Noting the type and source of wastes;
Monitoring combustion chamber temperature trends;
Observing the depth of the waste bed in the primary chamber; and
Observing ash burnout quality.
1. Charging log. Recording the time and amount of each charge is
called keeping a "charging log."
Record the time when each charge is made and the quantity of each
charge (1 bag, 5 bags, etc.). Monitoring charging in this way should
6-30
-------
P-edures are
,
:: saws
You should look for:
'
st-
X.tiSJ? PSSSs«3»~ '-~ ~»
6-31
-------
5. Observing the stack emissions. When black smoke is emitted from
the stack after charging, the amount charged probably was too much. The
incinerator does not have the capacity to combust all the volatiles
released. This situation may be correctable by increasing the secondary
combustion air. If increasing the secondary combustion air does not
alleviate the problem, the size of the charge should be decreased.
Control of the charging rate. The charging rate is probably the
easiest parameter for you to control. The rate can be controlled by
changing either the amount of waste charged with each load or by changing
the charging frequency.
Primary and Secondary Chamber Temperature.
Monitoring temperatures. You use temperature gauges to monitor the
primary and secondary chamber temperatures. All incinerators should have
a temperature gauge and preferably a temperature recorder. A temperature
recorder allows you to monitor trends in temperature.
Control of temperatures. You can control temperature by controlling
three parameters:
• Charging rate;
• Combustion air level; and
• Auxiliary burner operation.
The importance of charging rate has already been discussed. For a
multiple-chamber incinerator, you essentially control temperature by
controlling the charging rate. Increasing the waste feed rate increases
temperature; decreasing the waste feed rate decreases temperature. You
must balance the charging rate and air supply to sustain the desired
temperature without causing emissions. If sufficient temperature cannot
be maintained in the primary and secondary chambers, either the charging
rate is too low, insufficient heat is being added by the auxiliary burner,
or the excess air levels are too high. Remember, as additional excess air
is added, it cools the combustion gases; this is one of the reasons that
incinerator draft should be closely monitored.
The combustion air levels are adjusted by opening or closing the
dampers controlling the overfire air. Generally, opening the dampers
allows more air to enter the incinerator. Actual control of the air
depends on the type of combustion air system used, natural draft or forced
draft. The primary auxiliary burner can be used to increase temperatures,
if necessary.
For pathological incinerators, the primary and secondary burners must
be used to control incinerator temperature since little or no heat input
is derived from the waste. The combustion chamber temperatures are
increased or decreased by increasing or decreasing the auxiliary firing
rate in the primary chamber. If excess fuel usage is noted or proper
temperatures cannot be sustained, the combustion air settings should be
checked. Too much excess air will result in greater fuel usage. Since
6-32
-------
waste properties (heat content and moisture) will not normally chance for
pathologica wastes, the incinerator should operate steadily once it is
properly adjusted. Once the air settings are properly adjusted they
should not have to be frequently changed. aajustea, ™ey
U,cLr1mary ^ Secondarv Combustion Air Levels and Combustion Gas Qx^
rnn.h..c??It0r1nVf
-------
Monitoring draft. A draft gauge is required to measure the negative
pressure in the incinerator chamber.
Controlling draft. The draft within the chamber is controlled by
adjusting control dampers on the incinerator. For incinerators operating
under natural draft conditions, a damper in the stack gas flue may be used
to control draft; or a mechanized barometric damper often is used to
control the incinerator draft automatically to a preset level. If the
incinerator has an induced draft fan, dampers at the inlet or outlet of
the fan typically are used to control draft. These dampers may be
manually controlled, or may be mechanized to automatically adjust and
control incinerator draft to a preset level.
Other Parameters to Monitor. Other parameters you should monitor
include:
• Stack gas opacity;
• Stack gas carbon monoxide; and
• Burner flame pattern.
These items were discussed in the previous section on controlled-air
incineration, and the discussion is not repeated here.
SUMMARY OF CONTROL AND MONITORING TECHNIQUES FOR MULTIPLE-CHAMBER
iHCINcRArORS
The primary control parameter for a multiple-chamber incinerator is
the charging rate. Since both the primary and secondary chambers operate
with excess air, the combustion rate in the primary chamber cannot be
strictly controlled. Consequently, proper charging of the incinerator is
essential. The operator uses combustion chamber temperatures to monitor
incinerator operation. The charging rate (heat input) must be consistent
with incinerator capacity. The primary chamber auxiliary burner typically
will be set to cycle on when insufficient heat input is provided by the
waste. Adjustments to the air dampers also may be required to maintain
the proper draft and combustion air levels; damper control is often
automatically controlled by a mechanized system.
For pathological waste incinerators, the primary control variable is
the heat input rate from the primary chamber burner(s). Since the heat
content of the waste is insufficient to sustain combustion, the auxiliary
burners operate continuously, and the combustion air levels required
remain essentially constant.
PROPER ASH HANDLING PROCEDURES
Ash is manually removed by the operator at the end of each
incineration cycle. Proper ash handling procedures for multiple-chamber
incinerators are essentially the same as for batch and intermittent-duty,
controlled-air incinerators. The following are guidelines for good
operating procedures for manually removing ash from the incinerator:
6-34
-------
Allow the incinerator to cool sufficiently so that it is safe for
' r°remOVe ^ "h' Thl'S C°°11ng Can take as
r the a*h and combustion chamber with water to cool the
chamber because this can damage the refractory
^Ln/tf bl*nt !h°vel Or raking t001' not sharP ^jects that can
damage the refractory, for removing the ash. You should exercise
m^nntT'r ?1re the refract°ry "«y still be hot and the ash
may contain local hot spots, as well as sharp objects.
Avoid bumping or knocking of burner nozzle assemblies or
thermocouple housings.
Place^the ash into a noncombustible container such as a metal
container, not cardboard.
to c°o1 the ash and minimize
disposal. Cover the
according to approved procedures (according to
STARTUP AND SHUTDOWN PROCEDURE
Startup and shutdown of the incinerator requires some special stens
SL-^S^-Ril112!.?1]",10"- Specific maSufacturer's^ns^ct^s5
Startup
fJ T ^ previous C^c1e- Is ash quality
Roln n°h adJ"stments to operating procedures will be
. Pr*+ •, Remove,the ash fr°m the previous incineration cycle.
rlrn™ ?! Jecondary cortustlon chamber to the minimum
recommended temperature (e.g., 1800°F [980°C])
• Charge the incinerator with the first charqe
• Close the door.
• Ignite the waste using the primary burner.
Shutdown
f waste,1n the 1ast Char9e has burned down, the primary
o?mP-r-tUre W1T] be Mlnta1ned by the auxiliary burner at
? Cont1nued for a Predetermined length of
lnsPection indicates that burnout of the
«. K « e
waste bed is sufficient. When the burndown period is completed
the primary and secondary burners are shut down. comP'eted'
^?np5aJh°-°9icaL1ncinerators' shutdown of the incinerator
SS shutdown 1% the aSh bed' If d11 the material has
sted, shut down the primary and secondary burners. If was
If waste still
6-35
-------
remains on the hearth, continue to incinerate until acceptable burndown
has occurred.
DO'S AND DON'TS FOR OPERATING A MULTIPLE-CHAMBER INCINERATOR
DO:
• Preheat the secondary chamber prior to startup
• Pay careful attention to charging procedures and rates
• Shut off the primary burner when charging
• Monitor combustion chamber temperatures and learn to recognize
trends that indicate proper operation and trends that indicate
problems
• Monitor combustion chamber draft and maintain draft within the
proper operating range
• Routinely monitor stack gas opacity, especially after charging
• Pay attention to operation of your auxiliary burners; are they
properly cycling on and off? At the right times?
• Properly and carefully dispose of the ash
• Inspect the ash. Does visual inspection indicate poor burnout--
are pieces of uncombusted waste present? If ash quality is poor,
make changes to operating procedures/conditions
• For pathological wastes, operate the primary burner at all times
DON'T:
Overcharge the incinerator
Deeply pile pathological waste on the hearth
6-36
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REVIEW EXERCISE
8.
^^^—^™«^^— ^-«_
A monitor(s) that would be helpful to an
operator for controlling a multiple-
chamber incinerator is:
a. A combustion gas oxygen monitor
b. An opacity monitor
c. All of the above
d. a and b
7. False. The
secondary chamber
should always be
preheated.
8.
a.
9.
10.
11.
Key operating parameters for controlled-
air incinerators include: ,
, and '
Three key operating parameters for
multiple-chamber incinerators are
, and
The temperature within the secondary
combustion chamber should be:
a.
b.
c.
d.
e.
Maintained below 2200°F
Maintained above 1800°F
Disregarded
None of the above
a and b
An oxygen moni-
tor allows the
operator to
monitor excess
air levels.
9. Any of the
following:
Primary chamber
temperature,
secondary chamber
temperature, charg-
ing rate,
combustion air
level, combustion
gas oxygen con-
centration, or
combustion chamber
draft.
10. Any three of the
following:
Primary chamber
temperature,
secondary chamber
temperature, charge
rate, total
combustion air
level, combustion
gas oxygen concen-
tration, chamber
draft.
6-38
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REVIEW EXERCISE
1. The real concern about infectious (red
bag) waste is that:
a. It stinks
b. It may contain organisms that can
cause disease
c. It is messy
2. Proper waste handling includes:
a. Handling the waste as little as
possible
b. Using strong containers
c. Not overstuffing the charging hopper
d. Properly storing the waste
e. All of the above
3. It is not the operator's problem if bags
spill and break. True or False?
4. Multiple-chamber incinerators may use
either openings or draft
blowers to provide combustion air.
5. A major way that the operator can control
the incinerator is to control
the .
6. The most important parameters that the
operator should rely upon to monitor
operation are the primary and secondary
chamber temperatures. True or False?
7. When burning pathological waste it is not
necessary to preheat the secondary
combustion chamber. True or False?
1. b. It: may contain
organisms that
cause disease
2. e. All of the above
3. False. The operator
should be concerned
about broken bags
and report problems
to the appropriate
hospital personnel.
4. natural draft,
forced
5. charging rate
6. True. The tempera-
tures indicate
operating trends.
6-37
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REVIEW EXERCISE
12.
13.
14.
15.
19.
The operator should pay attention
to in the combustion chamber
temperatures.
It is always better to charge the
incinerator with very large charges and
as few times as possible in a day. True
or False?
During startup of the incinerator, the
operator should the secondary
combustion chamber.
Because pathological waste has
a heat content and high
- content, it requires special charging
and operating procedures.
The operator should routinely look at
the stack outlet to monitor the stack
gas .
11. e. a and b
12. trends or changes
13. False
14. preheat
18. low, moisture
19. opacity
6-39
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REFERENCES FOR SESSION 6
1. McRee, R. Operation and Maintenance of Controlled-Air
Incinerators. Ecolaire Environmental Control Products. Undated.
2. Ontario Ministry of the Environment. Incinerator Design and
Operating Criteria, Volume II - Biomedical Waste Incinerators.
October 1986.
3. U. S. Environmental Protection Agency Office of Solid Waste. EPA
Guide for Infectious Waste Management. EPA/530-SW-86-014.
(NTIS PB 86-199130). May 1986.
4. Letter from Ken Wright, John Zink Company, to J. Eddinger,
U. S. EPA. January 25, 1989.
5. Personal conversation between R. Neulicht, Midwest Research
Institute* and J. Kidd, Cleaver-Brooks. February 22, 1989.
6. Personal conversation with representatives of the National Solid
Waste Management Association. December 15, 1988.
7. U. S. Environmental Protection Agency. Municipal Waste Combustion
Study: Combustion Control of Organic Emissions. EPA/530-SW-87-021C.
(NTIS PB 87-206090). June 1987.
8. Ecolaire Combustion Products, Inc. Technical Paper: Controlled Air
Incineration. Undated.
9. Simonds Incinerators. Operation and Maintenance Manual for Models
751B, 1121B, and 2151B. January 1985.
10. Ecolaire Combustion Products, Inc. Equipment Operating Manual for
Model No. 480E.
11. John Zink Company. Standard Instruction Manual: John Zink/Comtro
A-22G General Incinerator and One-Half Cubic Yard Loader.
12. Brunner, C. Incineration Systems Selection and Design. Van Nostrand
Reinhold. p. 22. 1984.
13. Personal conversation between Roy Neulicht, Midwest Research Institute
and Larry Doucet, Doucet and Mainka Consulting Engineers.
November 29, 1989.
14. Doucet, L. C. Controlled-Air Incineration: Design, Procurement, and
Operational Considerations. American Hospital Association Technical
Series, Document No. 055872. January 1986.
6-40
-------
15. Air Pollution Control District of Los Angeles County Air
PB 22sf32)- u- '-'
- AS™
19. Personal conversation between Roy Keulicht, Midwest Research
Institute, and Steve Shuler, Ecolaire Combustion Products
20. Ashworth, R. Batch Incinerators-Count Them In Technical
Tehnal
Plication
L?i Rnn'l°nmenHaI Protection Agency. Workbook for Operators of
Small Boilers and Incinerators. EPA-450/9-76-001. March 1976.
6-41
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SESSION 7,
AIR POLLUTION CONTROL SYSTEMS OPERATION
-------
SESSION 7. AIR POLLUTION CONTROL SYSTEMS OPERATION
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 7-1
Introduction 7-1
WET SCRUBBERS - GENERAL 7-1
Scrubber Operation 7-1
VENTURI SCRUBBERS 7-2
Key Operating Parameters 7-2
Recommended Operating Ranges for Key Parameters 7-2
Monitoring of Key Parameters 7-2
Venturi Scrubber Operation 7-3
Venturi Scrubber Startup 7-3
Venturi Scrubber Shutdown 7-3
PACKED-BED SCRUBBER 7-3
Key Operating Parameters 7-3
Recommended Operating Ranges for Key Parameters 7-4
Monitoring of Key Parameters 7-4
Packed-Bed Scrubber Operation 7-4
Packed-Bed Scrubber Startup and Shutdown 7-4
FABRIC FILTERS 7-4
Key Operating Parameters 7-4
Recommended Operati ng Ranges for Key Parameters 7-5
Monitoring of Key Parameters 7-5
Fabric Filter Operation 7-6
Fabric Filter Startup 7-6
Fabric Fi Her Shutdown 7-6
DRY SCRUBBERS - GENERAL 7-7
Dry Scrubber Operation 7-7
SPRAY DRYERS 7-7
Key Operating Parameters 7-7
Recommended Operating Ranges for Key Parameters 7-7
Moni tori ng of Key Parameters 7-7
Spray Dryer Operation 7-8
Spray Dryer Startup 7-8
Spray Dryer Shutdown 7-8
-------
TABLE OF CONTENTS (continued)
Page
DRY INJECTION
Key Operation Parameters 7 g
Recommended Operating Ranges for Key Parameters 70
Monitoring of Key Parameters -, a
Dry Injection Operation 7 ~2
Dry Injection Startup '~\
Dry Injection Shutdown .'.*.'.*.'.*.".'.'.'.*.'.'.'.'.'.*.'.'.' 79
ELECTROSTATIC PRECIPITATORS 7_g
Key Operating Parameters
Recommended Operating Ranges for Key 'Parameters .'.*.'.'.'." 7 in
Monitoring of Key Parameters ('f°
ESP Operation ;-}?
ESP Startup 7-11
ESP Shutdown .*.'**.'.'.".*.'.".'.*.'.*.'.'.'.*.'.'.*.'.*.' 712
REFERENCES
* 7-16
-------
SESSION 7,
AIR POLLUTION CONTROL SYSTEMS OPERATION
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with:
• The key operating parameters and how to monitor those parameters
h%^lVS|r^sS;°La1r P°11Ut10n C°ntr01 W- Wo"
• Special operating considerations for ARCS startup and shutdown.
OBJECTIVES
Upon completing this session, you should be able to:
1. Identify the key operational parameters for your ARCS-
parameiersf ^ Operat1onal ran9es considered acceptable 'for these
3. Describe how to monitor the key parameters; and
*° "*"* Pr°Per ««"««"««• W ARCS
INTRODUCTION
-to^^^^
• Wet scrubbers
~ venturi scrubber
~ packed-bed scrubber
— spray towers
• Fabric filters
• Dry scrubbers
— spray dryer
— dry injection scrubber
• Electrostatic precipitators
WET SCRUBBERS - GENERAL
SCRUBBER OPERATION
7-1
-------
scrubbers will, focus only on those items that differ from venturi
scrubbers. Spray towers are relatively simple to operate, requiring only
that a proper liquid flow rate be maintained. Spray towers will not be
discussed separately.
VENTURI SCRUBBERS
KEY OPERATING PARAMETERS
The key operating parameters that are necessary for effective
operation of a venturi scrubber are liquid supply, energy as measured by
pressure drop (AP), and suspended solids in the scrubbing water.
RECOMMENDED OPERATING RANGES FOR KEY PARAMETERS
Proper operation of a venturi scrubber requires that scrubber &P,
water supply, and solids content be maintained within acceptable ranges as
specified by the manufacturer or by the air agency permit specifica-
tions. Recommended ranges of the parameters are:
• Pressure drop~20 to 30 in. w.c. (5.0 to 7.5 kPa)
• Liquid supply--? to 10 gallons per thousand actual cubic feet
(gal/1,000 acf) (0.9 to 1.3 liters per actual cubic meter [t/m ])
• Solids content~0 to 3 percent
MONITORING OF KEY PARAMETERS
To ensure proper operation of a venturi scrubber, the operator must
monitor the key operating parameters and determine the pressure drop and
liquid supply.
• Scrubber parameters which can be monitored by the operator
include:
— venturi pressure drop;
— liquid flow rate; and
— fan static pressure, rpm, or amperage.
• Pressure drop can usually be monitored directly from installed
gauges or manometers.
• The liquid supply can be obtained by comparing the liquid flow
rate, which is usually indicated by installed gauges, with the gas
flow rate. The gas flow rate can be obtained from fan specifica-
tions, which relate gas flow rate to either fan static pressure,
rpm, or amperage. At least one of these fan parameters is usually
readily available from manufacturer installed gauges.
• Suspended solids content is not easily measured. Acceptable
levels are usually obtained by maintaining adequate scrubbing
liquid recirculation rates.
7-2
-------
VENTURI SCRUBBER OPERATION
if the scrubber
^^
Uau unnK °n d v*^«ble-throat venturi scrubber 9
Liquid supply can be increased by increasing the liquid flow rate
If suspended solids cause solids buildup problems the makel
water and blowdown rates should be increased. P
VENTURI SCRUBBER STARTUP
sequence^?: * ^^ SCrUbber reqU1>es adherence to the following in-
Turn on the liquid recirculation system and liquid flow to the
venturi throat and the mist eliminator; e
Spec1fied b* the
damper;
pr°per gas flow rate 1s
Recheck the liquid flow rate, compare with the gas flow rate
d n t0 °btain 9 ^
VENTURI SCRUBBER SHUTDOWM
shouldT°b
Shut off the scrubber fan;
• Shut off the makeup water supply system.
PACKED-BED SCRUBBER
KEY OPERATING PARAMETERS
yheDHeysu^n^9 parameter! for a Packed-bed scrubber are liquid
y, PH, suspended solids content, and inlet gas temperature.
7-3
-------
RECOMMENDED OPERATING RANGES FOR KEY PARAMETERS
Because packed-bed scrubbers are usually used on hospital
incinerators primarily for acid gas control, pH maintenance is
important. High suspended solids levels can cause the same pluggage
problems as for venturi scrubbers. Packed-bed units do not have high
pressure drop requirements to enhance scrubbing; instead, they rely on
high liquid supply rates and increased surface area for absorption. High
inlet gas temperature can damage plastic packing media.
• The recommended,range for liquid supply is 10 to 15 cral/1,000 acf
(1.3 to 2.0 z/rn3).
• The recommended range of pH is 5.5 to 7.0.
• The recommended range for suspended solids is 1 to 3 percent.
• Acceptable inlet gas temperatures are dependent on the packing
media and scrubber material of construction and should be
specified by the manufacturer.
MONITORING OF KEY PARAMETERS
Monitoring of liquid supply and suspended solids for packed-bed
scrubbers are the same as discussed above for venturi scrubbers.
• Liquid feed pH usually can be monitored directly from a
manufacturer-installed pH meter.
• A thermocouple usually is provided to monitor the gas inlet
temperature.
PACKED-BED SCRUBBER OPERATION
Operation of packed-bed scrubbers with respect to liquid supply and
suspended solids is the same as that for venturi scrubbers.
• The liquid feed pH can be increased by increasing the alkaline
sorbent material feed rate to the scrubber water.
• Gas inlet temperatures can be controlled by controlling the flue
gas exhaust temperatures from the incinerator or by adjusting an
ambient air damper upstream of the scrubber.
PACKED-BED SCRUBBER STARTUP AND SHUTDOWN
Startup and shutdown procedures for packed-bed scrubbers are the same
as those indicated above for venturi scrubbers.
FABRIC FILTERS
KEY OPERATING PARAMETERS
The key operating parameters for pulse-jet fabric filters are the
maximum and minimum flue gas temperatures, the pressure drop through the
unit, and the cleaning air pressure.
7-4
-------
RECOMMENDED OPERATING RANGES FOR KEY PARAMETERS
Proper operation of a pulse-jet fabric filter requires that flue gas
temperatures do not get high enough to damage the bags or low enough to
allow condensation of moisture or acid gases to blind or corrode the
bags. The bags should be cleaned on a frequency that will prevent
excessive pressure drops that could result in ruptured bags and excessive
fan energy costs. The cleaning air pressure should be high enough to
ensure a shock wave in the bag sufficient to dislodge the filter cake.
• The maximum flue gas temperature is dependent on the bag material
and should be specified by the manufacturer.
• The minimum gas temperature is dependent on the moisture content
and acid gas content of the gas stream and should be maintained
above the dewpoints of both. In practice, the fabric filter
vendor or hospital engineer should specify a minimum flue gas
temperature.
• The recommended pressure drop range for a pulse-jet fabric filter
is 5 to 9 in. w.c. (1.2 to 2.2 kPa).
• The recommended range for the cleaning air pressure is 60 to
100 psig (410 to 690 kPa).
MONITORING OF KEY PARAMETERS
To ensure proper operation of a fabric filter, the operator should
ensure that all bags are intact, without holes or tears, and that the bags
are cleaned on an appropriate frequency with adequate cleaning air
pressure. The integrity of the bags should be checked by a visual
inspection when the system is off-line for routine maintenance.
• Parameters that can be monitored to maintain optimum fabric filter
performance are:
— opacity;
— pressure drop; and
— temperature.
• Opacity readings are taken at the stack by a trained observer or
from an opacity monitor. Visible emissions of greater than
5 percent opacity may indicate holes in the bags or too frequent
cleaning. If high opacities are observed, the bags should be
inspected visually by maintenance personnel.
• A manometer or pressure gauge is usually provided by the
manufacturer for measuring pressure drop. Excessively high
pressure drop can indicate:
— inadequate cleaning;
— bag blinding; or
— excessive gas volume.
• Fabric filters on hospital incinerators should be equipped with
continuous stripchart temperature recorders and high temperature
alarms. The stripchart recorder will indicate whether potential
bag damage may have occurred due to high temperature. The alarm
should be set lower than the critical bag damage temperature to
7-5
-------
allow for preventive actions. The alarm temperature setting
depends on the type of bag fabric used. These same devices can be
used to monitor against excessively low temperature.
FABRIC FILTER OPERATION
Under normal conditions, the operator only has to monitor the key
parameters and ensure that the airflow rate through the fabric filter is
sufficient to maintain negative draft in the combustion chamber of the
incinerator.
• If the flue gas temperature approaches the damage point, emergency
procedures should be taken to reduce the temperature by:
— bypassing the fabric filter;
— dropping the incinerator temperature by increasing combustion
airflow in the secondary chamber or reducing auxiliary fuel
rates; or
~ introducing cooling ambient air.
• If the dewpoint temperature is approached, the incinerator
secondary chamber burner firing rates should be increased to raise
the inlet temperature.
• If the pressure drop is too high, the bag cleaning frequency
should be increased.
• If the cleaning air pressure is too low, adjust the pressure gauge
on the compressed air system.
FABRIC FILTER STARTUP
Precautions should be taken during initial startup of a new fabric
filter or after bag replacement to prevent abrasion damage to the new bags
before a protective coating of dust has formed. Condensation of moisture
and acid gases should be prevented at all startups to prevent acid attack
and bag "blinding."
• New bag abrasion can be prevented by:
— operation of the incinerator at reduced throughput of waste
charge material to allow the gradual buildup of the dust cake;
and
-- precoating the bags
• Condensation of acid gases and moisture in a cold fabric filter
can be prevented by operating the incinerator on auxiliary fuel
prior to charging with waste until the fabric filter is heated.
FABRIC FILTER SHUTDOWN
The top priority during shutdown of a fabric filter is to avoid
dewpoint conditions with resulting condensation.
• The incinerator secondary chamber burner should be "aft on for a
few minutes after waste combustion is completed to remove moisture
from the fabric filter.
7-6
-------
;!eCOndary chamber burner ^ shut down, ambient air
" thr°Ugh the SyStem t0 Pur9e Dining combustion
S0!*USt1?!! prod.u!:ts are Pur9ed, the fabric filter should be
cake ^frn.nS 2° min^S °f bag cleanin9 to remove
CCa
occurs
DRY SCRUBBERS - GENERAL
DRY SCRUBBER OPERATION
The basic operating principle for both spray dryers and drv
is to mix an adequate supply of alkaline sorbent with the flue a
allow sufficient contact time for the reaction to occur On mol
'
SPRAY DRYERS
KEY OPERATING PARAMETERS
The key operating parameters that are necessary for effective
RECOWENDED OPERATING RANGES FOR KEY PARAMETERS
^
C°ntent is 5 to 20
180T ?30°/d-7«rb °J?3et 9aS temPerature difference of 90° to
180 F (30 to 80°C) will ensure evaporation of all moisture.
MONITORING OF KEY PARAMETFRS
7-7
-------
SPRAY DRYER OPERATION
The feed rate of dry sorbent to the makeup water In the sorbent mix
tank is adjusted to obtain the desired sorbent content of the slurry. The
flow rate of slurry to the atomizer in the reaction vessel is adjusted to
change the wet bulb/dry bulb temperature difference.
• The slurry flow rate is usually monitored by a magnetic flow
meter.
• An increase in slurry flow will reduce the wet bulb/dry bulb
temperature difference.
SPRAY DRYER STARTUP
Startup of a spray dryer should follow procedures that prevent
condensation in the system and ensure evaporation of all slurry moisture
in the scrubber reactor vessel.
• One method of ensuring evaporation is to use auxiliary fuel firing
to bring the exhaust gas temperature up to the normal operating
range before injecting the slurry.
• Another method would be to gradually increase slurry feed at
startup to maintain a 90° to 180°F (30° to 80°C) wet bulb/dry bulb
temperature d i fferent i a1.
SPRAY DRYER SHUTDOWN
Proper shutdown should ensure that no liquid moisture remains or
condenses in the spray dryer or fabric filter after shutdown..
• Auxiliary fuel firing should be used to maintain temperatures
above saturation until all sorbent is purged from the system.
• To prevent bag blinding and reaction product salt corrosion, the
fabric filter should go through a complete cleaning cycle before
shutdown.
DRY INJECTION
KEY OPERATION PARAMETERS
The key operating parameters for a dry injection system are the
sorbent injection rate and the particle size of the sorbent.
• The sorbent injection rate should provide adequate sorbent for
neutralization of the acid gases and is dependent on the acid gas
content of the flue gas.
• As particle size decreases, the surface area to volume ratio
increases which improves the efficiency of acid gas collection.
7-8
-------
RECOMMENDED OPERATING RANGES FOR KEY PARAMETERS
The particle size and injection rate of the sorbent should be
specified by the manufacturer.
• Generally the sorbent feed will have a particle size where
90 percent by weight will pass through a 325 mesh screen. This
dust is approximately the consistency of talcum powder.
MONITORING OF KEY PARAMETERS
Continuous monitors for outlet acid gas concentrations are usually
provided with dry scrubbing systems. u^uaiiy
• The sorbent feed rate can be determined directly from manufacturer
installed gauges.
• Proper particle sizes for the sorbent are specified at purchase
and are maintained by transporting and fluidizing the sorbent
inhr?hrna^-r?,LreLSU:LP^Um^iC-50nveyor-- The ai> "«• rate
lth is
DRY INJECTION OPERATION
Operation of a dry injection system is relatively simple.
• Maintain the pneumatic transfer line at a constant airflow rate
• Monitor outlet acid gas concentration and increase sorbent
injection rate to achieve desired acid gas levels.
DRY INJECTION STARTUP
There are no special startup considerations for dry injection At
DRY INJECTION SHUTDOWN
The only special concern for shutdown of a dry injection system is to
Sl± fa$"c .fm«- through d Cleaning CyCle aft*r sorJen? fnjlc^on is
stopped. This prevents possible blinding from condensation and reaction
product salt damage to the fabric filter components. reaction
ELECTROSTATIC PRECIPITATORS
KEY OPERATING PARAMETERS
The key operating parameters that are necessary for effective
pSwefinput! ^ ESP ^ 9dS temperature' Particulate resistivity, and
7-9
-------
RECOMMENDED OPERATING RANGES FOR KEY PARAMETERS
Proper operation of an ESP requires that the gas temperature,
particulate resistivity, and power input be maintained within acceptable
ranges as specified by the manufacturer or by the air agency permit
specifications. Recommended ranges for these parameters are::
• Gas temperature range:
-- Hot-side ESP, 572° to 800°F (300° to 430°C)
— Cold-side ESP, less than 400°F (200°C)
• Particulate resistivity range is 10 to 10 ohm-cm
• Power ratio of secondary power to the primary power input should
range from 0.5 to 0.9
~ secondary power = secondary voltage x secondary amperage
— primary power = primary voltage x primary amperage
MONITORING OF KEY PARAMETERS
To ensure proper operation of an ESP, the operator must monitor the
key parameters and make adjustments as necessary to maintain the
parameters in the appropriate range.
• ESP parameters that can be monitored by the operator include:
— gas inlet temperature
— particulate resistivity
-- primary voltage
— primary current
— secondary voltage
« secondary current
• The gas inlet temperature can be measured using a thermocouple
mounted at the inlet to the ESP. A temperature readout such as a
stripchart recorder or LED display should be available.
Temperatures should be maintained above the dewpoints of both
hydrochloric acid and moisture. Temperatures that are too low
allow moisture and acid to condense causing sticky particulate
that is difficult to collect and causing corrosion. Temperatures
that are too high may cause damage to the ESP and in hot-side
ESP's may cause the gas density to be so low that effective
collection is difficult.
• Particulate resistivity is a measure of the resistance of the
collected dust layer to the flow of electrical current. A high
resistivity indicates that little electricity will flow. The
condition of high resistivity is indicated by increased sparkover
or by excessive current at greatly lowered voltages. Low
resistivity (i.e., high electricity flow) means that particles
lose their charge too quickly. Particles take longer to move to
the collection plate, the particles are not held strongly to the
collection plate, and particle reentrainment is a problem.
Resistivity is measured using high voltage conductivity cells -
the accepted method is the point-plane method.
• The transformer-rectifier (TR) power equipment of most modern
ESP's are equipped with primary voltage and current meters on the
7-10
-------
low-voltage (ac) side of the transformer and secondary voltaae anH
current meters on the high-voltage rectified (dc) side of thf
EJEJoSr- ™erefore* the inPut ^de is the primly side of the
Jo*? J3 I™ Pnmary I"*61"3 measure Volta9e ™<* current In
volts and amps, respectively. The secondary meters measure
vo tage in kilovolts (volts multiplied by 1,000) and current in
m liamps amps divided by 1,000). To get the power miof
JoLr *P y I e primar* V01ta9e Beading by the primary current
S5 2 K° ?f Prima!;y P°Wer* (2] mult1P1y the secondary voltage
reading by the secondary current reading to get the secondary
power by the
ESP OPERATION
n°rmal Cond1ti°ns» the operator need only monitor the kev
sc enttaoaleterS-and 6n.SUre thdt the a1rflow ™t* through the ESP is
incinerator Pe9atlVe drdft in the combustion chamber of the
temperature is approached, the incinerator
erltSre"" fin'n9 ratM Sh°Uld be 1nCreaSed to
reducedfby? ^ temperature is to° hi9h» the temperature should be
— dropping the incinerator temperature
-- introducing cooling ambient air.
iv^ce-reSiStl'Vlty is to° hl'9h (i'e- ^creased sparking and/or
excessive currents at greatly lowered voltages), it can9be reduced
'
poor collection efficiency), it can be increased
- increasing the temperature of the gas by increasing the
incinerator secondary chamber burner firing rates
— checking operation of rappers
"" rnnff^9at1J9 1nc1nerat°r feed characteristics for high-sulfur
content or for excessive conditioning agents such as alkalis
" ~n° eff1C7'ency to reduce amount
If the primary voltage is too low, it can be corrected by
-- removing excessive ash from electrodes
— checking power supply
- checking for improper rectifier and control operation
-- checking for misaligned electrodes
— checking for high resistivity.
7-11
-------
ESP STARTUP
Startup of an ESP is generally a routine operation involving heating
a number of components such as support insulators and hoppers prior to
incinerator operation. The following steps should be taken to startup the
incinerator.
Prior to operation of the incinerator:
• Check hoppers
— level-indicating system should be operational
~ ash-handling system operating and sequence check - leave in
operational mode
— hopper heaters should be on
• Check rappers
-- energize control, run rapid sequence, ensure that all rappers
are operational
— set cycle time and intensity adjustments, using installed
instrumentation - leave rappers operating
• Check TR sets
-- test-energize all TR sets and check local control alarm
functions
-- set power levels and deenergize all TR controls
-- lamp and function-test all local and remote alarms
After the incinerator has gone through its preheat mode:
• Energize TR sets, starting with inlet field, setting Powertrac
voltage to a point just below sparking.
• Successively energize successive field as load picks up to
maintain opacity, keeping voltage below normal sparking (less than
10 flashes/min on spark indicator).
• Within 2 hours, check proper operation of collected dust removal
system.
• After flue gas at 200°F (93°C) has entered ESP for 2 hours,
perform the following steps:
— check all alarm functions in local and remote
— deenergize bushing heaters after 2 hours.
• Set normal rapping.
ESP SHUTDOWN
When charging has stopped and the incinerator goes into burndown
mode, shut the ESP down by doing the following:
• Deenergize ESP by field, starting with inlet field to maintain
opacity limit
• Deenergize outlet field when all fuel flow ceases and combustion
airflow falls below 30 percent of rated flow.
• Leave rappers, ash removal system, seal-air system, and hopper
heaters operational.
7-12
-------
*nHrh«nnrS ?*? 1nc1nerator shutdown, deenergize seal-air system
and hopper heaters. Secure ash removal system.
Eight hours after incinerator shutdown, deenergize rappers
Alarms "^ 1s * Conven1ent tim^ to check oplrliion of
7-13
-------
REVIEW EXERCISE
1. What is the recommended range for liquid
supply to a venturi scrubber?
a. 1-3 gal/1,000 acf
b. 4-6 gal/I,000 acf
c. 7-10 gal/1,000 acf
d. 12-15 gal/1,000 acf
2. What is the recommended range for
suspended solids in a venturi scrubber?
a. 0-3 percent
b. 4-6 percent
c. 7-10 percent
d. 10-15 percent
3, How can the pressure drop of a venturi
scrubber be increased?
a. Adjusting the fan damper
b. Increasing fan energy
c. Adjusting throat constriction
d. All of the above
4. What is the recommended range for liquid
supply to a packed-bed scrubber?
a. 3-5 gal/I,000 acf
b. 5-10 gal/I,000 acf
c. 10-15 gal/I,000 acf
d. 15-25 gal/1,000 acf
5. What is the recommended pH for a packed-
bed scrubber?
a. 2-3
b. 3-5.5
c. 5.5-7.0
d. 7.0-9.0
6. What is the recommended pressure drop
range for a pulse-jet fabric filter?
a. 1-5 in. w.c.
b. 5-9 in. w.c.
c. 10-15 in. w.c.
d. 15-20 in. w.c.
1. c.
7-10 gal/
1,000 acf
2. a. 0 to 3 percent
3. d.
All of the
above.
4. c.
10 to 15 gal/
1,000 acf
5. c. 5.5 to 7.0
7-14
-------
REVIEW EXERCISE (CONTINUED)
Excessively high pressure drop in a
^^KhA^st-f^Tx. * .. '
fabric filter may indicate what?
a.
b.
c.
d.
Inadequate cleaning
Bag blinding
Excessive gas volume
All of the above
What is the recommended wet bulb/dry
bulb^temperature difference for a spray
a. 10° to 25°F
b. 25° to 50°F
c. 50° to 75° F
d. 90° to 180°F
7. d.
All of the
above.
8. d. 90° to 180°F
7-15
-------
REFERENCES FOR. SESSION 7
1. Engineering Manual With Operation and Maintenance Instructions.
Anderson 2000, Inc. Peachtree City, Georgia. Undated.
2. Joseph, J. and D. Beachler. APTI Course SI:412C, Wet Scrubber Plan
Review - Self Instructional Guidebook. EPA 450/2-82-020. U. S.
Environmental Protection Agency. March 1984.
3. U. S. Environmental Protection Agency. Wet Scrubber Inspection and
Evaluation Manual. EPA 340/1-83-022. (NTIS PB 85-149375).
September 1983.
4. U. S. Environmental Protection Agency. Fabric Filter Inspection and
Evaluation Manual. EPA 340/1-84-002. (NTIS PB 86-237716).
February 1984.
5. Beachler, D.S. APTI Course SI:412, Baghouse Plan Review,. U. S.
Environmental Protection Agency. EPA-450/2-82-005. April 1982.
6. U. S. Environmental Protection Agency. Operation and Maintenance
Manual for Fabric Filters. EPA 625/1-86/020. June 1986,
7. Richards Engineering. Air Pollution Source Field Inspection Notebook;
Revision 2. Prepared for the U. S. Environmental Protection Agency,
Air Pollution Training Institute. June 1988.
8. U. S. Environmental Protection Agency. APTI Course SI:412B,
Electrostatic Precipitator Plan Review, Self-Instructional
Guidebook. EPA 450/2-82-019. July 1983.
9. U. S. Environmental Protection Agency. Operation and Maintenance
Manual for Electrostatic Precipitators. EPA 625/1-85-017. September
1985.
7-16
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SESSION 8.
MAINTENANCE INSPECTION-A NECESSARY PART OF YOUR JOB
-------
SESSION 8. MAINTENANCE INSPECTION—A NECESSARY PART OF YOUR JOB
TABLE OF CONTENTS
Page
INTRODUCTION g.j
INCINERATOR MAINTENANCE INSPECTIONS 8-2
Hourly Inspections 8-2
Daily Inspections " ] * 8-2
Weekly/Biweekly/Monthly Inspections '.'.'.'. 8-4
WET SCRUBBER MAINTENANCE INSPECTIONS 8-4
Dai ly Inspections 8-4
Other Inspections )*] 3-6
FABRIC FILTER MAINTENANCE INSPECTIONS 8-6
Dai ly Inspections 8-6
RECORDKEEPING 8-8
•
REFERENCES 8-12
LIST OF TABLES
TABLE 8-1. TYPICAL MAINTENANCE INSPECTION SCHEDULE FOR A
HOSPITAL WASTE INCINERATOR 8-3
TABLE 8-2. TYPICAL MAINTENANCE INSPECTION SCHEDULE FOR A
VENTURI SCRUBBER 8-5
TABLE 8-3. TYPICAL MAINTENANCE INSPECTION SCHEDULE FOR A
FABRIC FILTER SYSTEM 8-7
TABLE 8-4. DAILY MAINTENANCE INSPECTION LOG 8-9
-------
SESSION 8.
MAINTENANCE INSPECTION-^ NECESSARY PART OF YOUR JOB
SESSION GOAL AND OBJECTIVES
GOAL
To familiarize you with:
" Ihn,n!3Ur^' dai'1y' and Week1y maintenance inspections that vou
should^ake on your hospital incinerator and Sir po?lut?on control
" 3£«; a'nd061^ ^ ^ >' rep°rted to the -Intenance
• Recordkeeping systems.
OBJECTIVES
Upon completing this session, you should be able to:
basis!' U'St ^ maintenance inspections that should be made on an hourly
basis?' L1St the ma1ntenance inspections that should be made on a daily
basis;' U'St the ma1ntenance inspections that should be made on a weekly
^ 4. Identify and alert maintenance personnel of potential problems;
5. Implement a recordkeeping system.
INTRODUCTION
Recordkeeping or maintaining an activities logbook also^discussed.
8-1
-------
INCINERATOR MAINTENANCE INSPECTIONS
The incinerator maintenance inspections that you should perform are
listed in Table 8-1. The following sections describe these inspections in
detail.
HOURLY INSPECTIONS
The hourly incinerator inspections apply only to large incinerators
with automatic ash removal conveyors. On these systems, the following
inspections should be made every hour:
• The ash removal conveyor should be inspected to clear away any
debris that might cause it to jam; and
• The quench pit water level should be checked and water added if
necessary—water must be available to quench the ash and to
maintain the air seal that the water provides on the ash removal
conveyor.
DAILY INSPECTIONS
On a daily basis, stack gas monitors (if your incinerator is equipped
with one) should be checked for proper operation and various pieces of
equipment should be inspected and cleaned as required. The following
inspections should be made daily:
• If your incinerator is equipped with stack gas monitors, make
daily calibration checks on opacity monitor and check: readings on
oxygen, carbon monoxide or hydrogen chloride monitors—anything
out of the ordinary such as unusually low or high readings should
be reported to the maintenance department;
• Observe the exhaust stack for visible emissions and compare to the
opacity monitor reading—you should make these exhaust stack
observations several times a day especially after waste charging
and during the burndown mode;
• Check thermocouple temperature readings—anything out of the
ordinary such as slow response time or unusually low or high
temperature readings should be reported to the maintenance
department;
• On batch incinerators and prior to operation, inspect the charge
door seals for closeness of fit and wear by closing the charge
door and looking for any gaps in the door seal material—any gaps
should be reported to the maintenance department;
• Inspect limit switches for freedom of operation and remove any
obstructing debris; and
• On controlled-air incinerators, inspect and clean underfire air
ports—on batch units, cleaning is best accomplished by rodding
the air ports after the previous shift's ash has been
removed—large, continuous feed units usually have cleaning
mechanisms that may be used to rod out the air ports while the
unit is in operation. [Note that multiple-chamber incinerators
(i.e. excess-air units) are supplied with air through overfire air
ports that are unlikely to become plugged.]
8-2
-------
TABLE 8-
1. TYPICAL MAINTENANCENINSPECTION SCHEDULE FOR A HOSPITAL WASTE
Weekly
Stack
Oxygen monitor
Thermocouples
L-nit switches
Underfire air ports
Blower intakes
Induced-draft fans
Biweekly Control panels
Monthly External surface of
incinerator and stack
Inspect and clean as required
Inspect water level and fill as required
Check readings; check daily calibration
values
Check exhaust for visible emissions
Check oxygen level of exhaust
Check temperature readings
Inspect for freedom of operation and
potential obstructing debris
Inspect and rod out
Inspect for accumulations of lint debris
and clean as required
Inspect and clean fan housing as required.
Check for corrosion and V-belt drives
and chains for tension and wear
Inspect and clean as required. Keep panel
securely closed and free of dirt to pre-
vent electrical malfunction
Inspect external "hot" surfaces. White
spots or discoloration may indicate loss
of refractory
8-3
-------
MEEKLY/BIWEEKLY/MONTHLY INSPECTIONS
Every week, all blower intakes and induced-draft (ID) fans used for
heat recovery should be inspected for dirt accumulation and cleaned as
required. Also, the ID fans used for heat recovery should be inspected
for corrosion, and V-belt drives and chains should be checked to make sure
they are not frayed or loose. Any corrosion or wear and any loose or
frayed V-belts or chains should be reported to the maintenance department.
Every 2 weeks, the incinerator's control panel should be inspected
for dirt accumulation and cleaned as required. The panel door should be
kept closed to prevent dirt accumulation and electrical malfunction.
Every month, you should inspect the outer surface of the incinerator
and the refractory lining inside. Any discoloration or white "hot" spots
on the outer surface may indicate a loss of refractory inside the unit and
should be reported to the maintenance department. These white spots are
usually the first indication of internal refractory damage. When the
refractory lining is cold, random cracks may be seen that vary in width
from 1/32 to 3/16 inch (0.01 to 0.07 centimeter). These cracks are normal
and close up when the refractory expands at operating temperatures. The
purpose of inspecting the cold refractory each month is to observe any
changes in existing cracks and to discover any holes larger than the
cracks. These inspections are very important because replacing badly
damaged refractory is very expensive. However, minor damage caught early
enough may be repaired by the maintenance department using plastic
refractory material.
WET SCRUBBER MAINTENANCE INSPECTIONS
The wet scrubber maintenance inspections that you should perform are
listed in Table 8-2. The following section describes these inspections in
detai1.
DAILY INSPECTIONS
The following inspections should be made on a daily basis:
• Inspect the following equipment for leakage by looking for
scrubber liquid escaping from the components and for any liquid on
surfaces directly under the equipment. All leaking components
should be reported to the maintenance department for repair.
— scrubber liquid pump
— variable throat activator
— scrubber liquid lines
— mist eliminator pressure lines
— reagent feed system
• Inspect the scrubber liquid pump for proper operation by noting
the flowmeter reading—lower flow rates than normal may indicate
pump problems.
• On variable throat venturi scrubbers, inspect the variable throat
activator for proper operation by moving the activator and
checking the resulting pressure drop—the activator should move
8-4
-------
TABLE. 8-2. TYPICAL MAINTENANCE INSPECTION SCHEDULE FOR A
VENTURI SCRUBBER
Inspec-
tion
frequency
Component
Daily Scrubber liquid pump
Variable throat activator
Scrubber Iiquid Iines
Mist eliminator pressure lines
Reagent feed system
Fan
Fan belt3
Monthly Duct work
Procedure
Check for proper operation and leakage
Check for proper operation and leakage
Check for leakage
Check for leakage
Check for leakage
Check for vibration and proper operation
Check for abnormal noise or vibration
Inspect for leakage
8-5
-------
freely and the pressure drop should increase as the activator is
moved upwards to constrict the venturi throat.
• Inspect the scrubber fan and fan belt for any abnormal vibration
or noise—any abnormal vibration or noise indicates that the fan
should be serviced by the maintenance department.
OTHER IMSPECTIONS
Every month, the off-gas ductwork should be checked for leakage,
i.e., look for holes and listen for air being sucked in. Any problems
should be reported to the maintenance department for repair.
All other maintenance activities will likely be performed by the
maintenance department during regular shutdowns. Such activities include
inspecting the internal scrubber components for corrosion, abrasion, and
material buildup (monthly); lubricating scrubber components including fan
and pump (weekly); inspecting fan, pump, motor, and drag chain bearings
and damper seals, bearings, blades and blowers for wear and loose fittings
(semiannually); and checking the accuracy of flowrates (semiannually).
FABRIC FILTER MAINTENANCE INSPECTIONS
The fabric filter maintenance inspections that you should perform are
listed in Table 8-3. The following section describes these inspections-in
detai1.
DAILY INSPECTIONS
The following inspections should be made on a daily basis:
• Inspect the exhaust stack for visible emissions—a sudden change
in opacity may indicate the failure of one or more system
components including broken/leaking bags or a malfunctioning
cleaning system—the appearance of puffing smoke indicates pinhole
leaks in a filter bag(s);
• Check and record fabric pressure loss and fan static pressure--
sudden changes in the pressure drop may indicate problems;
i.e. high pressure drop may indicate mudded bags or cleaning
system failure (listen to the system-does it sound different?)
while low pressure drop may indicate fabric failure (holes);
• Check the compressed air system for air leakage by observing the
system's pressure gauge—air leakage may be indicated by a lower
pressure than normal;
• Check all indicators on the fabric filter control panel and listen
to the system in operation—you should become familiar with the
sounds that your system makes when operating normally ; and
• Inspect the dust removal system to see that dust is being removed
from the system by checking the conveyor for jamming, pluggage,
wear, broken parts, etc.—problems with the conveyor system are
indicated when the conveyor appears to be moving but no dust is
dropping into the dust storage container, when the conveyor does
not move, or when the conveyor makes unusual sounds.
8-6
-------
TABLE 8-3. TYPICAL MAINTENANCE INSPECTION SCHEDULE FOR A FABRIC
rlLTER SYSTEM
Check exhaust for visible dust
Daily
Compressed air system
Col lector
Rotating equipment and drives
Dust removal system
Hoppers
«
and fan
trends.
ic pressure.
<°ss
Watch for
Check for air leakage (low pressure).
Check valves.
Observe all indicators on control panel
and listen to system for properly
operating subsystems.
Check for signs of jamming, leakage
broken parts, wear, etc.
Check to ensure that dust is beina
removed from the system.
Check for bridging or plugging by
looking into the hopper with the
system shut down.
8-7
-------
If you encounter any of the indicators of deteriorating performance listed
above, you should report the problem(s) to the maintenance department for
repair.
RECORDKEEPING
Recordkeeping of maintenance inspections is an important part of an
equipment operation and maintenance program. The objectives of
recordkeeping are to prevent premature failure of equipment, increase
equipment life, and minimize air pollution. These objectives can be
achieved by observing trends in the frequency and types of maintenance
required and by detecting problems early through regular maintenance
inspections. Table 8-4 shows an example of a daily maintenance inspection
log that you could use to record the dates and times when specific
inspections are performed. A similar log can be set up for inspections
that occur weekly or less frequently. You could set a log up for the
incinerator and another for the air pollution control device.
8-8
-------
TABLE 8-4. DAILY MAINTENANCE INSPECTION LOG
Facility name:
Operator's name:
Date:
Ash remova I conveyor
Water quench pit
Opac i ty mon i tor
Oxygen monitor
Underfire air ports
Ash pit/dropout sump
Stack
Scrubber liquid pump
Variable throat activator
Scrubber liquid lines
Mist eliminator pressure lines
Reagent feed system
Fan
Fan belt
8-9
-------
REVIEW EXERCISE
1. It is the operator's responsibility
to the different parts of the
incinerator and air pollution control
device on a regular basis.
2. Maintenance inspections allow you to
identify minor problems before they
develop into large, repairs.
3. The ash removal conveyor should be
inspected every hour to clean away any
debris that might cause it to .
4. Daily calibration checks should be made
on the monitor.
5. The exhaust stack should be checked
for emissions and compared to
the opacity monitor reading.
6. Limit switches should be checked for
freedom of operation and any
obstructing removed.
7. The underfire air ports should be
inspected daily and cleaned (rodded) as
necessary. True or False?
8. All blower intakes and induced draft
(ID) fans should be inspected weekly
for accumulation and cleaned as
required.
9. Any frayed or loose V-belt drives and
chains or any corrosion found during
inspection of ID fans should be reported
to the department.
10. White spots or discoloration of the
outer surface of the incinerator found
during the monthly inspection may
indicate a of refractory inside
the unit and should be reported to the
maintenance department.
1. inspect
2. expensive
3. jam
4. opacity
5. visible
6. debris
7. True
8. dirt
9. maintenance
(continued)
8-10
-------
REVIEW EXERCISE (CONTINUED)
11.
12.
13.
14.
15.
16.
List three of the five scrubber
components that should be inspected
daily for fluid leakage.
The fan, including bearings and belt,
should be checked daily for any
abnormal or vibration.
Every month, the scrubber off-gas
ductwork should be checked for
and air being sucked in.
When a baghouse is used, a sudden change
]n the of the exhaust gas may
indicate the failure of one or more
system components including broken/
leaking bags or a malfunctioning
cleaning system.
Changes in the pressure drop across the
fabric filter indicate the failure of
one or more system components. True or
False?
You should inspect the fabric filter
dust removal system to see that dust is
being removed from the system by
checking the conveyor for jamming, wear,
broken parts. True or False?
10. loss
11. Scrubber liquid
pump
Variable throat
activator
Scrubber liquid
lines
Mist eliminator
pressure lines
Reagent feed system
12. noise
13. holes
14. opacity
15. True
16. True
8-11
-------
REFERENCES FOR. SESSION 8
1. Personal conversation between M. Turner, MRI, and W. Tice Rex
Hospital, Raleigh, North Carolina. August 16, 1988.
2. Murphy, P., and Turner, M. Report of Site Visit to Ecolaire
Combustion Products, Charlotte, North Carolina. July 20,, 1988.
3. Allen Consulting and Engineering. Municipal Waste Combustion Systems
Operation and Maintenance Study. EPA-340/1-87-002. June 1987.
4. Ecolaire Combustion Products, Inc. Equipment Operating Manual for
Model No. 2000TES; Equipment Operating Manual for Model No. 480E.
5. U. S. Environmental Protection Agency. Wet Scrubber Inspection and
Evaluation Manual. EPA 340/1-83-022. (NTIS PB 85-149375)
September 1983.
6. Joseph, J. and Beachler, D. APTI Course SI:412C, Wet Scrubber Plan
Review, Self-Instructional Guidebook. U. S. Environmental Protection
Agency. EPA 450/2-82-020. March 1984.
7. Engineering Manual with Operation and Maintenance Instructions.
Anderson 2000, Inc. Peachtree City, Georgia. Undated.
8. U. S. Environmental Protection Agency. Operation and Maintenance
Manual for Fabric Filters. EPA/625/1-86/020. June 1986,.
8-12
-------
SESSION 9.
TYPICAL PROBLEMS
-------
SESSION 9. TYPICAL PROBLEMS
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 9_2
INTRODUCTION g_2
INCINERATOR PROBLEMS 9_3
PREVENTING PROBLEMS 9_9
WET SCRUBBER PROBLEMS 9_u
PREVENTING PROBLEMS 9_14
FABRIC FILTER PROBLEMS 9_16
PREVENTING PROBLEMS 9_17
REFERENCES , 9.18
LIST OF FIGURES
Figure 9-1. Black smoke leaving stack 9_3
Figure 9-2. White smoke leaving stack 9_4
Figure 9-3. White smoke/haze above the stack g_5
Figure 9-4. Smoke leaking from primary chamber 9-7
Figure 9-5. Excess auxiliary fuel usage g_8
Figure 9-6. Incomplete burnout/poor ash quality 9-10
Figure 9-7. Causes of high opacity emissions 9_14
Figure 9-8. Causes of high pressure drop 9_15
-------
SESSION 9,
TYPICAL PROBLEMS
SESSION GOAL AND OBJECTIVES
GOAL
OBJECTIVES
Upon completing this session, you should be able to:
•and a!; * cntr' °Perat1°nal pr°bl« WUh ^Inerators
\' ^9l?KZevuhe Cf"Ses of °Perat1°nal problems; and
problems " aCtl°nS t0 tdke t0 Correct and ^^ operational
INTRODUCTION
sF--™
require costly, time-consuming repairs.
INCINERATOR PROBLEMS
PROBLEM NO. PROBLEM DESCRIPTION
Black smoke leaving stack
2 White smoke leaving stack
9-1
-------
4
5
6
PROBLEM NO. 1
CAUSE:
SOLUTION/PREVENTION:
PROBLEM NO. 2
PROBABLE CAUSE:
SOLUTION/PREVENTION:
PROBLEM NO. 3
White smoke or haze appearing a short distance above
the stack
Smoke leaking from primary chamber
Excessive auxiliary fuel usage
Incomplete burnout/poor ash quality
Black smoke leaving stack (see Figure 9-1)
Incomplete burning of waste
• Not enough air for good combustion
Overcharging or charging highly volatile
material
Poor mixing in secondary chamber
• Burner failure
• Operating at too high a primary chamber
temperature
Do the following, in order, to correct the problem:
• Check/increase secondary chamber combustion air
• Check/decrease primary chamber combustion air
(underfire air or overfire air)
• Check secondary chamber temperature/assure above
minimum level
• Decrease charge size or charge rate
• Check burner operation—if no flame or a poor
flame is visible through the flame viewport,
call maintenance to repair
Steady stream of white smoke leaving stack (see
Figure 9-2)
Small aerosols in stack gas
• Too much air entering incinerator
• Secondary chamber temperature too low
Do the following, in order, to correct the problem:
• Be sure secondary burner is operating properly
• Be sure temperature of secondary chamber is
above 1800°F (980°C)
Check/decrease underfire air
• Check/decrease secondary chamber air
• If the above steps fail to eliminate white
smoke, the feed material probably contains
pigments, metallic oxides, or minerals (often
found in paper sacks).
White smoke/haze appearing a short distance above
stack (see Figure 9-3)
9-2
-------
Too Much
Highly Volatile
Waste
BLACK
SMOKE
Too Much
Underfire Air
•*- Not Enough
P\ Secondary Air
Figure 9-1. Causes of black smoke.
9-3
-------
\
WHITE/
BLUE-WHITE
SMOKE
^-Secondary Chamber
\r Temperature Too Low
U
r\
.Too Much
Secondary Air
Figure 9-2. Causes of white smoke.
9-4
-------
Hydrochloric
Acid Gas
Condensing
WHITE
SMOKE/HAZE
APPEARING
SHORT DISTANCE
FROM STACK
\
Figure 9-3. Cause of white plume a short distance above the stack.
9-5
-------
PROBABLE CAUSE:
SOLUTION/PREVENTION:
PROBLEM NO. 4
CAUSE:
SOLUTION/PREVENTION:
PROBLEM NO. 5
CAUSE:
SOLUTION/PREVENTION:
Hydrochloric acid gas condensing
Not much you can do unless you can:
Reduce amount of chlorinated waste incinerated
in each ioad, or
Eliminate chlorinated plastics from use in
hospital, or
Install acid gas scrubbing system
Smoke leaking from primary chamber (see Figure 9-4)
Positive pressure in primary chamber
• Too much underfire air
Too much highly volatile material charged
Problem with draft damper or induced draft fan
(poor draft)
Primary chamber temperature too high
Do the following, in order, to correct the problem:
Check stack damper or fan operation
Check/decrease underfire air
• Decrease feed rate
Check charging door seals for leakage
Too much auxiliary fuel usage (see Figure 9-5)
Not enough heat input from waste to keep temperature
high enough
Inconsistent charging of incinerator
Insufficient underfire air (starved-air units)
or poor underfire air distribution
• Too much secondary combustion air
• Too much air infiltration
• Fuel leakage
Wet waste
• Excessive draft
• Burner setting too high
Do the following to correct the problem:
• Charge waste at regularly timed intervals at a
rate near 100 percent of incinerator capacity
(Example: For 500 Ib/h (230 kg/h) unit, charge
50 Ib (23 kg) every 6 minutes)
• Spread wet waste with other waste through
several charges—do not charge all of the wet
waste at one time
• Check/increase underfire air (controlled-air
unit); check air ports and distribution
Check/reduce secondary combustion air
Check/reduce draft
Check charging door seals and other seals for
air leakage
9-6
-------
Malfunction In Stack
Damper or Fan
SMOKE LEAKING
FROM PRIMARY
CHAMBER
Too Much -~—-""""^A
Highly Volatile
Waste
itile )f\
Too Much
Primary Air
Figure 9-4. Causes of leaking smoke.
9-7
-------
Leaky
Door Seal
Inconsistent
Waste Charging
TOO MUCH
AUXILIARY
FUEL USAGE
r\
Too Much
Secondary Air
Fuel Leak
\
Improper
Underfire Air
Distribution
Not Enough
Undertire Air
Figure 9-5. Causes of excessive auxiliary fuel use.
Q-fl
-------
PROBLEM NO. 6
CAUSE NO. 1:
Check/decrease burner setting
• Check fuel trains and burners for fuel leakage
Incomplete burnout/poor ash quality (see Figure 9-6)
(Three causes of this problem are detailed below.)
Not enough underfire air or poor distribution
Improper underfire air setting
Clinker buildup around underfire air ports
previous charges
SOLUTION/PREVENTION:
CAUSE NO. 2:
Do the following to correct the problem-
• Check underfire air setting and adjust if needed
Check around underfire air ports for clinker
buildup and clean as needed
• Rod underfire air ports daily to remove clinker
buildup and ash
Improper waste charging
• Overstuffing incinerator
Too much wet waste
SOLUTION/PREVENTION: Do
CAUSE NO. 3:
the following to correct the problem:
Charge waste at regularly timed intervals at a
rate near 100 percent of incineration capacity
50XihP 5; f°V 5°° lbc/h [23° kg/h] unit* change
50 Ib [23 kg] every 6 minutes). Do not
overstuff
• Spread wet waste through several charges-do not
charge all of the wet waste at one time
Insufficient burndown time
SOLUTION/PREVENTION: Do the following to correct the problem:
Allow longer burndown period
• Use primary burner to maintain temperature
during burndown period
PREVENTING PROBLEMS
1. Properly charge the incinerator.
9-9
-------
Too Much
Waste/Wet Waste
Improper
Underfire Air
Distribution
Not Enough
Underfire Air
Insufficient
Burnout Period/
Temperature
INCOMPLETE
BURNOUT/POOR
ASH QUALITY
Figure 9-6. Causes of incomplete burnout/poor ash quality.
9-10
-------
WET SCRUBBER PROBLEMS
PROBLEM NO.
7
8
9
10
PROBLEM NO. 7
CAUSE:
SOLUTION/PREVENTION: Maintain the PH of
following:
• Check alkaline addition system for leaks daily
and have the maintenance department repair if
needed r
• Check pH monitor that controls alkaline
additions daily
• Have the maintenance department perform regular
preventive maintenance on pumps, pipes" valves
service **** preparation equipment in slurry'
PROBLEM DESCRIPTION
Corrosion of scrubber parts
pattern™*10"' ddmpers stuck' P°or nozzle spray
Erosion of dry service components
Erosion in wet service components
Corrosion of scrubber parts (scrubbers, absorbers
fans, dampers, ductwork, exhaust stack pumps
valves, pipes, tanks, feed preparation equipment)
Acid buildup in scrubbing liquid from absorption of
10* SUlfUr tr1oxide' and
SCrubbin9
doing the
PROBLEM NO. 8
Fan vibration, dampers stuck, poor nozzle
pattern
spray
9-11
-------
CAUSE:
SOLUTION/PREVENTION:
PROBLEM NO. 9:
CAUSE:
Scaling/plugg-ng
Preventive maintenance
Periodic cleaning of equipment
Erosion in dry service components (fans, dampers,
ductwork)
Erosion of fan blades
• Holes in ductwork
Droplet carryover due to poor mist eliminator
performance
Normal operation
CAUSE:
SOLUTION/PREVENTION:
SOLUTION/PREVENTION: Preventive maintenance
Repair/replacement of equipment
PROBLEM NO. 10: Erosion in wet service components (scrubber and
scrubber spray nozzles) (if recirculation is not
practiced, then erosion in wet service will not be a
problem)
Suspended solids in scrubbing liquid
High recirculation flow rate compared to makeup
and purge flow rates
Infrequent purging of system
Preventive maintenance
Purge system frequently to prevent solids
buildup
• Adjust recirculation rate as needed
PREVENTING PROBLEMS
It is better to prevent a problem than to have to correct a problem
after it has occurred. A few actions you can take to prevent problems
with a wet scrubber are noted below.
1. Maintain proper pH for scrubber liquid.
2. If recirculation is used, maintain low level of solids in
scrubbing liquid.
3. Establish preventive maintenance program to inspect and clean
scrubber parts, including nozzles, fan, and dampers. (The Maintenance
Department would be responsible for this action.)
FABRIC FILTER PROBLEMS
Problems with fabric filters are usually indicated by either
unusually high or low pressure drop readings or by high opacity (greater
than 5 percent) from' the fabric filter stack. High pressure drop
9-12
-------
indicates a higher resistance to airflow meaning that the filter
Acid gas and water condensation can be prevented bv
z
such
equipped with alarms and a bypass sacha v r f.
temperature exceeds or falls below a certain limit FiifS V J •
may be eliminated by proper installation of thi JfitJ h /59 abrasion
PREVENTING PROBLEMS
9-13
-------
HIGH OPACITY
STACK EMISSIONS
Improperly
Installed Bags
Broken Bags
BAGHOUSE
Figure 9-7. Causes of high opacity emissions.
-------
Moisture
Condensation
Cleaning System
Falureor
Infrequent
Cleaning
HIGH
PRESSURE
DROP
BAGHOUSE
I
Figure 9-8. Causes of high pressure drop across fabric filter.
9-15
-------
REVIEW EXERCISE
1. Which of the following problems is
probably caused by too much air entering
the incinerator and insufficient
temperature?
a. Black smoke leaving stack
b. White smoke leaving stack
c. Poor ash quality
d. Incomplete burnout
2. Increasing the charging rate is a 1. b. White smoke
possible solution to the problem of leaving the
black smoke leaving the stack. True or stack
False?
3. If smoke is leaking from the primary 2. False?
chamber, there may be either too much
underfire air, poor draft, or too much
highly volatile material in the
charge. True or False.
4. Which of the following are possible 3. True
causes for incomplete burnout and poor
ash quality.
a. Not enough underfire air
b. Improper waste charging
c. Insufficient burndown time or
temperature
d. All of the above
e. None of the above
5. Corrosion of parts of a wet scrubber is 4. d. All of the
caused by:' above
a. Too much iron in the water
b. Acid buildup in the scrubbing liquid
c. Both of the above
d. Neither of the above
(continued)
9-16
-------
8.
9.
10.
REVIEW EXERCISE (CONTINUED)
6.
7.
Problems such as plugging, stuck
dampers, and fan vibration resulting
from deposits on fan blades are caused
by:
a. Scaling
b. Erosion
c. Corrosion
Erosion in the scrubber and scrubber
spray nozzles can be reduced by which of
the following?
5- b. Acid buildup in
the scrubbing
liquid
6. a. Scaling
a.
b.
c.
d.
e.
Rod out spray nozzles regularly
Purge system frequently
Adjust recirculation rate if needed
All of the above
b and c only
When a fabric filter is operating
normally, the opacity of stack emissions
should be very low (less than
5 percent). True or False?
Which of the following are possible
causes of fabric failure resulting in
high opacity?
7. e. b and c only
8. True
a.
b.
d.
e.
f.
Improper installation of filter bags
High temperature in the fabric
filter baghouse
Acid gas condensation on the filter
bags
Abrasion of the filter bags
All of the above
b, c, and d
High pressure drop indicates a high
resistance to flow. True or False?
e. All of the
above
10. True
9-17
-------
REFERENCES FOR SESSION 9
1. U. S. Environmental Protection Agency. Workbook for Operators of
Small Boilers and Incinerators. EPA-450/9-76-001. March 1976.
2. Letter from K. Wright, John Zink Company to J. Eddinger, U. S. EPA.
January 25, 1989.
3. Personal conversation between R. Neulicht, MRI, and G. Swan, Ecolaire
Combustion Products and J. Kidd, Cleaver Brooks. February 22, 1989.
4. Joseph, J., and D. Beachler. APTI Course SI:412C, Wet Scrubber Plan
Review—Self Instructional Guidebook. EPA 450/2-82-020.
U. S. Environmental Protection Agency. March 1984.
5. U. S. Environmental Protection Agency. Wet Scrubber Inspection and
Evaluation Manual. EPA-340/1-83-022. (NTIS PB 85-149375).
September 1983.
6. U. S. Environmental Protection Agency. Operation and Maintenance
Manual for Fabric Filters. EPA 625/1-86/020. June 1986.
7. McRee, R. Operation and Maintenance of Controlled-Air Incinerators.
Ecolaire Environmental Control Products. Undated.
9-18
-------
SESSION 10.
STATE REGULATIONS
-------
SESSION 10. STATE REGULATIONS
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES 10_2
INTRODUCTION 1Q_2
THE AIR POLLUTANTS 10_3
REGULATORY REQUIREMENTS 10_4
Emission Limits IQ-4
Monitoring and Recordkeeping ,!.*.".*.'."." 10-7
Enforcement of State Regulations !!!!!!!! 10-8
Operator Traini ng ,!.'!,*.'! 10-8
YOUR STATE REGULATION 10_8
LIST OF FIGURES
Figure 10-1. Concentration standards 10-3
Figure 10-2. Correction for dilution 10-4
Figure 10-3. Exhaust gas monitors 10-6
-------
SESSION 10,
STATE REGULATIONS
SESSION GOAL AND OBJECTIVES
GOAL
that wl" "Pe"s °f «"• *""•««• regulations
OBJECTIVES
Upon completing this session, you should be able to:
that are
*** **"" °f re^^ that .ay be included in
is
INTRODUCTION
as-rf t^^j^.XTsarf p-"'^%outso .e
to meet stricter requirements ror Sore onutants"^^0^ ?ty-be.requ1red
and very small incinerators may have rew restHctlons? lnc"««tors,
• Emission limits for air pollutants that leave the incinerator
• Operating practices/limits;
of
The requirements for your particular st*+a u,-m i,
addition to these requirement your faci?i?v -f? funwirlzed later. In
"permit" from the Statelnd/or'loraT UflJ V J1 have recei"ved a
requirements for your ?nc^nemor and ??r Ln'^ may 1nclude sPecific
.ay be more strict than'ne" r'egula'ons?"^01 SyStem that
10-1
-------
THE AIR POLLUTANTS
Listed below are the air pollutants from hospital waste incinerators
that may be covered by emission limits in State regulations
Particulate matter;
Carbon monoxide;
Sulfur dioxide;
Nitrogen oxides;
Hydrochloric acid gas;
Toxic metals (arsenic, beryllium, cadmium, chromium, nickel, lead
mercury); and
Organics (dioxins/furans, ethylene, propylene).
REGULATORY REQUIREMENTS
EMISSION LIMITS
State regulations are designed to limit air pollutant emissions to
certain acceptable levels. The emission limits may be expressed in
several different ways depending on the type of pollutant.
The most common type of emission limit is the concentration standard
which limits either the mass (weight) or. volume of the pollutant in the
gas exiting the stack. This type of emission limit is expressed as
follows and is described pictorially in Figure 10-1:
Example
1 grain per dry
standard cubic foot
(1 gr/dscf) at 7 per-
cent oxygen
Type of pollutant Explanation
Particulate matter
100 parts per
million (100 ppm)
Carbon monoxide
Sulfur dioxide
Nitrogen oxides
Hydrogen chloride
No more than 1 grain (there
are 7,000 grains in 1 pound)
of particulate matter may be
contained in each cubic foot
of gas leaving the stack
corrected to 7 percent oxygen
and standard conditions (20°C,
and 1 atm) (Oxygen correction
and standard conditions are
explained below)
No more than 100 cubic feet
(cubic meters) of pollutant
may be contained in 1 million
cubic feet (cubic meters) of
gas leaving the stack
10-2
-------
1 Gram
•1 Foot-
1 Foot
,1 Foot
K>
100 Cubic
Feet
1 Grain Per Dry Standard
Cubic Foot*
Contains 1 Million
Cubic Feet
"1 pound=7000 Grains
100 Parts Per million
Figure 10-1. Concentration standards.
10-3
-------
For metric units, mass/volume concentrations are expressed as milligrams
per dry standard cubic meter (mg/dscm). The conversion is:
1 gr/dscf = 2,300 mg/dscm
For metric units, volume/volume concentrations are expressed as ppm.
Because a concentration standard limits the amount of pollutant in a
certain amount of stack gas, someone having a problem meeting the standard
might be tempted to increase the amount of air to dilute the concentration
of the pollutant. As air is added, the oxygen concentration in the gas
increases because the air contains 21 percent oxygen. To keep this from
happening, regulations usually either forbid the addition of dilution air
or require that the concentration be "corrected" to a standard level of
oxygen, usually 7 percent, or'a standard level of carbon dioxide, usually
12 percent. Figure 10-2 illustrates this concept.
Emission limits are often given for standard conditions, e.g. 0.1
grain/dry standard cubic foot. Standard temperature is 68°F (20°C) and
standard pressure is 29.92 in. w.c. (760 millimeters of mercury). A cubic
foot measured at this temperature and pressure is known as a standard
cubic foot. When a stack test is performed to check the level of
emissions from an incinerator, both temperature and pressure are measured
during the test in addition to the pollutant of interest. The test
results are then converted to standard conditions (grain/dry standard
cubic foot) using the temperature and pressure measured. In this way, all
test results of all sources including incinerators can be compared on the
same basis, i.e., all results are reduced to standard conditions.
Another type of standard is the percent reduction standard.
Sometimes the emission limit is expressed as a percent reduction of the
pollutant. In other words, the pollution control device must operate at
or above a specified efficiency level (such as 90 percent removal) to
reduce the pollutant emissions. This type standard frequently is used for
acid gases such as HC1. For example, if the emission standard requires at
least 90 percent reduction of HC1, and the HC1 in the combustion gas is
entering the scrubber inlet at a rate of 20 Ib/h (9.1 kg/h),, then the
allowed emission rate is 2 Ib/h (0.9 kg/h), which is 10 percent of the
amount entering the scrubber.
Another type of standard (shown below) sometimes found in State
regulations is called an ambient concentration standard. 11: limits the
amount of pollutant that collects at ground level in areas surrounding the
emission source. Usually, the regulation requires that the pollutant be
measured as it leaves the stack. This measurement information is then
used by a computer to calculate the amount of the pollutant at various
locations near the source.
10-4
-------
--, 1 gr/dscf
i 7% oxygen
•J 12% caroon dioxide
Barometric
Damper —
Closed
1 gr/dscf
' 7% oxygen
12% cartoon dioxide
INCINERATOR
Combustion Air
21% oxygen
79% nitrogen
0% carbon dioxide
Barometric
Damper —
Open
! 0.5 gr/dscf
1 14% oxygen
6% carbon dioxiae
1 scf air
21% oxygen
0% carbon dioxide
. 1 gr/dscf
' 7% oxygen
12% carbon dioxiae
INCINERATOR
Combustion Air
21% oxygen
79% nitrogen
0% carbon dioxide
1 gr/dscf @ 7% Oa = 0.5 gr/dscf @ 14% O2
1 gr/dscf @ 12% CO2 = 0.5 gr/dscf @ 6% CO2
Figure 10-2. Correction for dilution.
10-5
-------
Example Type of pollutant Explanation
1 microgram p^r cubic Toxic metals No more than 1 microgram of
meter (1 ug/m ) Organics pollutant may be contained in
Hydrogen chloride each cubic meter of air.
(There are 1 million
micrograms in 1 gram).
A third type of standard that is almost always included in
regulations is an opacity standard. It is expressed as a limit on the
degree to which the stack emissions are visible and block the visibility
of objects in the background. Stack emissions of 100 percent opacity
would totally block the view of background objects and indicate high
pollutant levels. Zero percent opacity would provide a clear view of the
background and indicate no detectable particulate matter emissions.
Opacity may be estimated by taking "readings" every 15 seconds and
averaging the readings over a specified time period. The "reader" must be
a certified opacity reader. The U. S. EPA Reference Method 9 "Visual
Determination of the Opacity of Emissions" establishes the procedures and
criteria for taking opacity readings and for certification. Additionally,
opacity may be estimated by comparing the opacity of the smoke to the six
sections of a Ringelmann Smoke Chart. The six sections are numbered from
0 to 5 with No. 0 being completely white and No. 5 completely black.
Sections 1 through 4 correspond to opacities of 20 percent (No. 1), 40
percent (No. 2), 60 percent (No. 3), and 80 percent (No. 4). Opacity is
estimated by choosing the section which most closely resembles the opacity
of the exhaust gas. Opacity may also be measured by an instrument called
a transmissometer that is installed in the stack. The following further
illustrates an opacity standard.
Example Type of pollutant Explanation
10 percent opacity Particulate matter The opacity of the emissions
(6-minute average) cannot average more than
10 percent for any 6-minute
period.
MONITORING AND RECORDKEEPIN6
• Certain types of records are commonly required by State
regulations or operating permits. Most of them are listed below
and involve recording the levels indicated on automatic monitoring
devices periodically or require recording the parameters
continuously.
-- Temperature of incinerator chamber(s)
— Oxygen concentration of exhaust gas
— Temperature at inlet and/or outlet of control device
— Continuous emission monitoring records (carbon monoxide or
opacity)
— Weight of waste charged to incinerator
— Air pollution control device operating parameters:
10-6
-------
a. Scrubber
• Pressure drop
• Liquid flow rate
b. Fabric filter
• Pressure drop
Keeping good records of instrument readings and
practices is important because if
that y°U are properl* °"e™t"* »"d maintaining
~ Allows you to prepare accurate annual (or more freaupnti •
reports that may be required by State regulation! I *
ENFORCEMENT OF STATE REGULATIONS
Tn da11y* weekly' and monthly records
Inspect equipment and monitoring devices
• Observe your work procedures
• "Read" the opacity of stack emissions
• Measure stack emissions ("stack test")
OPERATOR TRAINING
operas
to sute,
YOUR STATE REGULATION
specific requirements of your Stats regulation
t0 "* the
10-7
-------
SUMMARY OF REGULATIONS FOR THE STATE OF
Your Incinerator
Regulated
Type of requirement State regulation (Yes/No) Level
Applicability
Type of waste charged
Size of incinerator
Age of incinerator
Emission limits
Particulate matter
Opacity
Carbon monoxide
Sulfur dioxide
Hydrogen chloride
Nitrogen oxides
Toxic metals
Organics
Other
Operating practices
Limits on chracteristies of
waste charged (moisture,
volatility, etc.)
Waste packaging
Waste charging practices
Primary chamber temperature
Secondary chamber temperature
Residence time
Feed rate
Ash burnout levels
Ash handling and disposal
practices
Shutdown requirements
Control device temperature
Other
(continued)
10-8
-------
SUMMARY OF REGULATIONS FOR THE STATE OF
(continued)
Type of requirement
Equipment requirements
Incinerator design
Interlock systems
Automatic charging
Automatic ash removal
Other
Recordkeepinq
Incinerator temperature
Primary chamber
Secondary chamber
Control device
Temperature
Pressure drop
Liquid flow rate
Continuous monitoring records
Weight of waste charged
Other
Continuous emission monitoring
Opacity
Sulfur dioxide
Nitrogen oxides
Hydrogen chloride
Carbon monoxide
Other
Operator training
State regulation
Jfour incinerator
Regulated
(Yes/No) Level
10-9
-------
REVIEW EXERCISE
1. State regulations may include
which of the following?
a. Air pollution emission
limits
b. Operating limits
c. Monitoring and recordkeeping
requirements
d. Requirement for operator
training
1. a
2. b and c
3. d
4. a, b, c, and d
2. State regulations may be 1. 4. a, b, c, and d
different for different size
incinerators. True or False?
3. The State or local agency can 2. True
include special rules and
limitations in your permit to
operate that are more strict
than typical State regulations.
True or False?
4. Which of the following operating 3. True
practices are sometimes
regulated by States?
a. Waste packaging and waste
charging practices
b. Ash handling and disposal
practices
c. Temperatures and residence
times for incinerator
chambers
d. All of the above
e. a and b above
5. Some State regulations require 4". d. All of the above
that incinerator operators be
trained. True or False?
(continued)
10-10
-------
REVIEW EXERCISE (CONTINUED)
6.
7.
Name at least two types of
records that you may be required
to keep by State regulations.
Which of the following might an
enforcement official do to
determine if you are complying
with regulations?
a.
b.
c,
d.
e.
Examine your records
Inspect equipment
Observe your work procedures
Sample stack emissions
All of the above
8. When the stack gases are
perfectly clear, that is the
same as percent opacity
9. The greater the opacity reading,
the better. That is, 30 percent
opacity is better than
10 percent opacity. True or
False?
6.
True
Any of the following:
temperature of incinerator
chamber(s), control device
temperature, emission
levels, opacity, weight of
waste charged, scrubber
pressure drop or liquid
flow rate
7. e. All of the above
8. zero
9. False
10-11
-------
SESSION 11,
SAFETY: AN IMPORTANT PART OF YOUR JOB
-------
SESSION 11. SAFETY: AN IMPORTANT PART OF YOUR JOB
TABLE OF CONTENTS
Page
SESSION GOAL AND OBJECTIVES u_i
WASTE HANDLING u i
"Red Bag" Waste !.!!.".'!!!!! il-l
Possible Health and Safety Problems with Red Bag Waste...! .'.*.*.*.* 11-3
How to Avoid These Problems H_3
INCINERATOR OPERATION ^,5
Possible Injuries and Safety Hazards !!,!!!!! 11-6
General Safety Precautions.... ...'.'. 11-6
Burner Safety Precautions „.'!!.'.* H_6
Charging Safety Precautions [['.'. H_Q
Ash Removal Safety Precautions ',[ n_e
AIR POLLUTION CONTROL DEVICE OPERATION H_8
Wet Scrubbers—Possible Injuries and Hazards , tl-8
Wet Scrubbers—Safety Precautions H_8
Fabric Filters—Possible Hazards 11_9
Fabric Filters—Safety Precautions ...!!! 11-9
Proper Protective Clothing and Safety Equipment .* 11-10
REFERENCES U_15
LIST OF FIGURES
Figure 11-1. The biological hazard symbol 11_2
Figure 11-2. Torn waste bag H_4
Figure 11-3. Proper safety gear H_5
-------
SESSION 11.
SAFETY: AN IMPORTANT PART OF YOUR JOB
SESSION GOAL AND OBJECTIVES
GOAL
t0 Prevent Job-related
Objectives
Upon completing this session, you should be able to:
.us,* s
2. Name the types of containers used for infectious waste-
J. Describe proper waste-handling procedures;
wear on'the^bp6 protcct1ve Clothing and safet* equipment you should
5. Recognize the types of waste that must be discarded in red bags;
incinerator?16 ^^ °f mdterials that should never »* fed into an
precautions to take when charging the
from tSi t0 tdke When rem°Ving the
on.SiSS
operaton anhowt them fabric <
WASTE HANDLING
"RED BAG" WASTE
Hospital infectious wastes usually are discarded in
'
11-1
-------
Figure 11-1. The biological hazard symbol.
11-2
-------
Listed below are the types of hospital waste that are considered
infectious:
• Waste that has been in contact with isolation patients with
communicable diseases;
• Microbiological laboratory wastes, including cultures and stocks
of infectious agents;
• Blood, blood products, and body fluids;
• Pathological wastes;
• Sharps (needles, laboratory glass wastes, etc.); and
• Human and animal tissue, body parts, and bedding.
POSSIBLE HEALTH AND SAFETY PROBLEMS WITH RED BAG WASTE
• Sharp objects (e.g., needles) might pierce through a bag and
pierce yci!r skin.
• ...fectious waste might spill onto your skin or clothing if a bag
is opened or torn.(See Figure 11-2)
• Airborne micro-organisms might be inhaled.
• Micro-organisms might be swallowed.
HOW TO AVOID THESE PROBLEMS
DO
• Keep bags from tearing or breaking open by:
— Handling bags as little as possible.
— If necessary, asking hospital management to use:
Stronger or double bags, and/or
Cardboard containers or rigid carts to hold bags until they
are burned.
• Wear proper protective clothing and safety equipment (See
Figure 11-3)
— Thick rubber gloves
— Hard-soled rubber shoes
~ Safety glasses
— Dust mask
— Disposable coveralls or hospital scrubs
• Change clothing and launder daily
• Wash hands with soap after handling waste and before eating or
drinking.
DO NOT
Open bags.
• Crush/compact bags.
• Eat or drink around incinerator.
11-3
-------
Figure 11-2. Torn waste bag.
11-4
-------
Thick rubber gloves
Ear protectors
Hard-soled rubber shoes
Oust mask
Long-sleeved shirt/coveralls
Safety glasses
Figure 11-3. Proper safety gear.
11-5
-------
INCINERATOR OPERATION
You may face a number of potential hazards in operating a hospital
incinerator that can be avoided if you take the proper precautions.
POSSIBLE INJURIES AND SAFETY HAZARDS
• Burns caused by:
— Contact with hot surfaces of incinerator or other equipment
-- Careless charging procedures
— Careless ash removal procedures
~ Opening inspection ports when incinerator is operating
• Injury caused by:
— Getting too close to moving belts or hydraulic cylinders
— Lack of caution on elevated walkways
' Exposure to air contaminants or lack of oxygen caused by:
— Leak in equipment or ductwork
~ Poor ventilation of area
GENERAL SAFETY PRECAUTIONS
DO
• Wear proper protective clothing with no loose flaps, belts, etc.,
that might get caught on moving mechanical parts
Thick rubber gloves
Hard-soled rubber shoes
Safety glasses
Oust mask
Disposable coveralls
• Be careful around all moving belts, hydraulic cylinders, and doors
• Avoid contact with hot surfaces of:
Incinerator chamber
Heat recovery equipment (boiler)
Ductwork
Stack
• Be on the lookout for fuel (gas/oil) leaks.
• Use caution on elevated walkways and keep your hands on the
siderails. Be alert to gaps in the walkway or obstacles you could
trip over.
• If you notice unusual odors around an indoor incinerator, open
doors or windows to ventilate the room.
• If you develop any of the following symptoms that may indicate
contaminated air or lack of oxygen-, leave the area immediately:
Headache - Nausea
Drowsiness - Loss of coordination
Shortness of breath - Eye irritation
DO NOT
Open inspection ports to look into the incinerator during
operation.
11-6
-------
T feet 1nt° "Khanlcal chambers of feed ram assembly
"6"" T1"" U"1tS are often " "
to
place
BURNER SAFETY PRECAUTIONS
• Prevent the burner from igniting until it has gone through a purge
• Shut fff fJe ^U611 SUpply if the burner fai'ls; and
Shut off the fuel supply if the. combustion air supply fails.
IM:he system is not properly purged prior to ignition an explosion could
tYo°Uproht°ectd y^T ^ "* °Vern'de the flame S^^ ^™'> « is there
CHARGING SAFETY PRECAUTIONS
DO
. RQ en *I preY10us Char9e has burned down.
Be sure the primary chamber burner is off.
• btand behind and away from the door
DO NOT
• Look into open charge door.
• Charge bottles containing flammable liquids or explosives.
ASH REMOVAL SAFETY PRECAUTIONS
DO
• Use either
or conveyor (if available), or
^ P?acnS\^¥lSi^1f^sharP obJ'ects 1" the ash.
11-7
-------
DO NOT
• Enter the incinerator chamber.
• Damage the incinerator refractory with the shovel or rake.
• Spray water into chamber.
• Handle ash directly; if you must pick something up by hand, wear
protective gloves.
AIR POLLUTION CONTROL DEVICE OPERATION
The two types of air pollution control devices that you are most
likely to find at a hospital incinerator are wet scrubbers and fabric
filters. This section contains information about hazards associated with
control devices and safety precautions that you should know.
WET SCRUBBERS—POSSIBLE INJURIES AND HAZARDS
• Chemical burns can be'caused by the scrubber liquor if it gets on
your skin or in your eyes.
• Falls could occur on wet areas around the scrubber caused by leaks
in the scrubber vessel, ductwork, or piping.
' Injury could result from getting too close to a fan or fan belt
drive assembly, in which clothing could get caught. A vibrating
fan could cause the fan assembly to disintegrate, causing serious
injury.
• Hearing loss could be caused by the noise of operation of the
scrubber.
WET SCRUBBERS—SAFETY PRECAUTIONS
DO
• Avoid contact with scrubber liquor. If it does get on your skin
or in your eyes, flush with water for at least 15 minutes, and
seek medical attention for eye injuries.
• Know the location of the nearest eyewash and how to use it.
• Be alert for scrubber leaks and potential slippery walkways. Ask
maintenance to repair major leaks.
• Stay clear of rotating fan drive shafts where clothing could get
caught.
• Stay clear of fan belt drive assembly where clothing could get
caught or belts could break.
• Protect your hearing by wearing earplugs or earmuffs.
00 NOT
Place hand in fan belt/pulley assembly.
Continue to operate scrubber if fan is severely vibrating; shut
down incinerator and call maintenance.
11-8
-------
FABRIC FILTERS-POSSIBLE
-ur «hen handling dust
r ,
operate at about 35F (iso-c" SrS 9eneral1*
belt
«,,d cause the fan asse*,
"Used b* the ~'» of th. operation of the
sPeci'al hazards are insiriP the fabric filter ,,kaw
Hot, free flowing solids
Oxygen deficiency
High voltage
Moving mechanical parts
FABRIC FILTERS-SAFETY
00
get
• If you must enter'the fabric filter:
Wlth ™echa"1"' ^ration
- Purge the incinerator and fabric filter with *ir «•„ * •
exhaust gases before entering to drive out
— Be sure fan is "locked out"
- Stay in the fabric mter for as sh^t a't^'as possible
DO NOT
* rnnti hdn? 1n fan be1t/Pulley assembly.
.
11-9
-------
PROPER PROTECTIVE CLOTHING AND SAFETY EQUIPMENT
To protect yourself from possible injury or exposure to harmful
substances, wear the following items when working on a control device:
Eye protection (safety glasses)
Hearing protection
Long-sleeved shirt
Rubber gloves
Hard-soled rubber shoes
Oust mask
11-10
-------
REVIEW EXERCISE
2.
5.
The reason you need to be especially
careful when handling red bag waste is
because it might contain one or more of
,the following things that could be
harmful to you.
a. Human blood and blood products
Pathological wastes
Needles
Explosive chemicals
All of the above
a, b, and c above
b.
c.
d.
e.
f.
a.
b.
c.
Hospital infectious waste usually is
discarded in red plastic bags or
containers marked with which of the
following symbols?
The universal biological hazard
symbo1
A label that says "DANGER-HAZARD"
A picture of a skull and crossbones
To help keep waste bags from tearing or
breaking open, you should
them as little as possible";~~~
If a red bag appears to contain a
suspicious substance, you should open it
to be sure it is okay to put in the
incinerator. True or False?
Name the proper clothing and equipment
you should wear when handling waste.
1.
2.
4.
5.
f. a, b, and c
above
a.
3. handle
False. Never open
a red bag.
Thick rubber gloves
Hard-soled rubber
shoes
Safety glasses
Dust mask
Disposable
coveralls
11-11
-------
REVIEW EXERCISE
6. To remove the ash from the back
of the ash compartment, you
should
a. Go into the chamber and
shovel it out.
b. Use a rake or flat shovel
with a handle long enough to
reach the back without you
having to enter the chamber.
c. Flush it out with water.
7. If you want to look into the
incinerator during operation, it
is okay to open an inspection
cleanout port. True or False?
8. When operating the incinerator,
you should wear thick rubber
shoes, safety glasses, and a
dust mask. True or False?
9. Which of the following symptoms
may indicate exposure to air
contaminants or lack of oxygen?
a. Headache
b. Drowsiness
c. Shortness of breath
d. Nausea
e. Loss of coordination
f. Eye irritation
g. All of the above
h. All except b.
6. b. Use a rake or shovel
with a long handle.
7. False
8. True
9. g. All of the above
11-12
-------
REVIEW EXERCISE
10.
11.
12.
13.
14.
15.
16.
You should avoid contact with
the scrubber liquor because it
a. Can cause chemical burns to
your skin or eyes
b. Will make you pass out if
you smell it
c. Will give you a fatal skin
disease
Choose from the following words
to fill in the blanks below
describing the control device
safety hazards you should be
aware of: noise, toxic chemi-
cals, fans, leaks, fan belt.
Vibrating
in scrubber vessel,
ductwork, or piping
High levels
in the dust
from the fabric filters
and pully
assemblies
No special training is required
before entering a fabric
filter. True or False?
10. a. Can cause chemical
burns to your skin or
eyes
11. fans
12. leaks
13. noise
14. Toxic chemicals
15. Fan belt
(continued)
11-13
-------
REVIEW EXERCISE (CONTINUED)
17. Which of the following hazards 16. False
are associated with the inside
of a fabric filter.
a. Toxic gases and dust
b. Hot, free flowing solids
c. Oxygen deficiency
d. High voltage
e. Rotating equipment
f. All of the above
g. All except d
17. f. All of the above
11-14
-------
REFERENCES FOR SESSION 11
'::rs -
''
sr-
5. U. S. Environmental Protection Agency. Air Pollution Source
' «ud«t Manual. '
annnk i1"9 Systems dnd E^
-------
GLOSSARY
-------
GLOSSARY
ABSORPTION. The process by which gas molecules are transferred to
(dissolved in) a liquid phase.
ACID GASES. Corrosive gases formed during combustion of chlorinated or
halogenated compounds, e.g., hydrogen chloride (HC1).
ACTUAL CUBIC FEET PER MINUTE (acfm).3 A gas flow rate expressed with
respect to temperature and pressure conditions.
AIR, DRY.1* Air containing no water vapor.
ASH. The noncombustible inorganic residue remaining after the ignition
of combustible substances.
ASH COMBUSTIBLES. The fraction of combustible organic material remaining
in the bottom ash as measured by the loss on combustion technique.
ATOMIZATION.1* The reduction of liquid to a fine spray.
AUXILIARY FUEL BURNER. Burner in either the primary or secondary chamber
fueled by natural gas or fuel oil. Used to maintain temperature if
waste has too little heating value.
BAG BLINDING. The loading, or accumulation, of filter cake to the point
where capacity rate is diminished.
BAROMETRIC SEAL.1 A column of liquid used to hydraulically seal a
scrubber, or any component thereof, from the atmosphere or any other
part of the system.
BOTTOM ASH.5 The solid material that remains on a hearth or falls through
the grate after incineration is completed.
BURN RATE. The total quantity of waste that is burned per unit of time
that is usually expressed in pounds of waste per hour.
BURNDOWN PERIOD. The period of time in an incinerator's operating cycle
during which no additional waste is charged to the incinerator and
the primary combustion chamber temperature is maintained above a
irrininum temperature (using auxiliary burners as necessary) to
facilitate the solid phase combustion of the waste bed.
BURNOUT. A measure of ash quality; it is the percentage of the ash that
is inorganic material.
CHARGE RATE. Quantity of waste material loaded into an incinerator over a
unit of time but which is not necessarily burned. Usually expressed
in pounds of waste per hour.
-------
CHARGING^DOOR.^The opening through «hich waste is charged to the
are
CLINKERS.5 Hard, sintered, or fused pieces of residue formed in an
incinerator by the agglomeration of ash, metals, glass? and ceramics.
COLLECTION EFFICIENCY.1 The ratio of the weight of pollutant collected to
the total weight of pollutant entering the collector C0l1ected to
COMBUSTION AIR.5 The air used to burn a fuel or waste.
COMBUSTION GAS.5 The mixture of gases and vapors produced by burning.
CONDENSATION.1 The physical process of converting a substance from the
*
phase
c0LmLhE!!,?Jn INhCIN"ATI9N'5 Incineration utilizing two or more
combustion chambers in which the amounts and distribution of air to
f?rst zon^rh^VT^1^ Parttal ^ustion takes ??a?e In the
fZne '1 arS "^ t0 C°m
t1me dt the end of an Incinerator's
down r rnoH h the incinerator is allowed to cool
down. The cooldown period follows the burndown period.
CROSSL
stL?eam. ^ °f SCrUbbing 11qu1d normal (Perpendicular) to the gas
DAMPER.2 An adjustable plate installed in a duct to regulate gas flow.
°f dn °bject to the V01ume of
-------
DRAFT. A gas flow resulting from pressure difference; for example, the
pressure difference between an incinerator and the atmosphere, which
moves the products of combustion from the incinerator to the
atmosphere. (1) Natural draft: the negative pressure created by the
difference in density between the hot flue gases and the
atmosphere. (2) Induced draft: the negative pressure created by the
vacuum action of a fan or blower between the incinerator and the
stack. (3) Forced draft: the positive pressure created by the fan
or blower, which supplies the primary or secondary air..
EXCESS AIR. Burning with combustion air supply greater than
stoichiometric air requirements.
FIXED CARBON. The nonvolatile organic portion of waste.
FLAME PORT. Opening between the primary chamber and mixing chamber of a
multiple chamber incinerator through which combustion gases pass.
FORCED DRAFT. (See Draft).
FUGITIVE EMISSIONS. Emissions not released through a duct or stack such
as furnace leaks and wind blown ash.
GRID.1 A stationary support or retainer for a bed of packing in a packed
bed scrubber.
HEADER.1 A pipe used to supply and distribute liquid to downstream
outlets.
HEATING VALUE. The amount of heat that is released when a material is
combusted usually expressed as Btu/lb.
5
HEARTH. The bottom of a furnace on which waste materials are exposed to
the flame.
HEAT INPUT. Total energy released from burning;
(heating value [Btu/lb]xfeed rate [lb/h]).
HUMIDITY, ABSOLUTE.2 The weight of water vapor carried by a unit weight
of dry air or gas.
HUMIDITY, RELATIVE.2 The ratio of the absolute humidity in a gas to the
absolute humidity of a saturated gas at the same temperature.
INCINERATOR. A thermal device which combusts organic compounds using heat
and oxygen.
-------
INDUCED DRAFT FAN.3 A fan used to move a gas stream by creating a
negative pressure. (See Draft). creating a
°f Produc1n* *n ^ectlous disease in
INORGANIC MATERIAL.5 Chemical substances of mineral origin not
containing carbon to carbon bond. ur'9in, not
tle
*>
•di forwater
MIST
NATURAL DRAFT. (See Draft).
PARTICLE." Small discrete mass of solid or liquid matter.
-------
PARTICULATE MATTER. As related to control technology, any material
except uncombined water that exists as a solid or liquid in the
atmosphere or in a gas stream as measured by a standard (reference)
method at specified conditions. The standard method of measurement
and the specified conditions should be implied in or included with
the particulate matter definition.
PATHOGENIC. Waste material capable of causing disease.
PATHOLOGICAL WASTE. Waste material consisting of anatomical parts.
PATHOGEN. Organism capable of causing disease, generally a bacteria or
virus.
PENETRATION.* Fraction of suspended particulate that passes through a
collection device.
pH. A measure of acidity-alkalinity of a solution.
PILOT. A burner that is used to ignite waste and auxiliary fuel during
startup.
PLUME. Combustion gases exhausted from the stack.
PRESSURE DROP. The difference in static pressure between two points due
to energy losses in a gas stream.
PRESSURE,. STATIC.1* The pressure exerted in all directions by a fluid;
measured in a direction normal (perpendicular) to the direction of
flow.
PRIMARY CHAMBER. Chamber with hearth or grate that receives waste
material and in which the waste is ignited.
PRODUCTS OF INCOMPLETE COMBUSTION. Materials other than carbon dioxide,
water, and acid gases that are produced when organic materials are
burned.
PYROLYSIS. The chemical destruction of organic materials in the presence
of heat and the absence of oxygen.
QUENCH. Cooling of hot gases by rapid evaporation of water.
REAGENT. Reactive material used to remove acid gases from the combustion
gases.
RED BAG WASTE. As used in this document, red bag waste refers to
infectious waste; the name comes from the use of red plastic bags to
contain the waste and to clearly identify that the waste should be
handled as infectious.
-------
REFRACTORY. Nonmetallic substances used to line furnaces because they
can endure high temperatures and resist abrasion, spall ing, and
slagging.
RESIDENCE TIME. Amount of time the combustion gases are exposed to
mixing, temperature, and excess air for final combustion.
RETENTION TIME. Length of time that solid materials remain in the primary
chamber.
SATURATED GAS. A mixture of gas and vapor to which no additional vapor
can be added, at specified conditions.
SECONDARY COMBUSTION CHAMBER. Component of the incinerator that receives
combustion gases from the primary chamber and completes the
combustion process.
SIZE DISTRIBUTION/ Distribution of particles of different sizes within a
matrix of aerosols; numbers of particles of specified sizes or size
ranges, usually in micrometers.
SLURRY.1 A mixture of liquid and finely divided insoluble solid
materials.
1^
SMOKE. Small gasborne particles resulting from incomplete combustion;
particles consist predominantly of carbon and other combustible
material; present in sufficient quantity to be observable
independently of other solids.
SPECIFIC GRAVITY.1 The ratio between the density of a substance at a
given temperature and the density of water at 4°C.
SPRAY NOZZLE.1 A device used for the controlled introduction of scrubbing
liquid at predetermined rates, distribution patterns, pressures, and
droplet sizes.
STACK. Any chimney, flue, vent, or duct arranged to discharge combustion
gases to the air.
STANDARD CUBIC FEET PER MINUTE (scfm).3 A gas flow rate expressed with
respect to standard temperature and pressure conditions.
STARVED-AIR INCINERATION. Controlled air incineration in which the
primary chamber is maintained at less than stoichiometric air
conditions.
STOICHIOMETRIC AIR. The theoretical amount of air required for complete
combustion of waste to C02 and H20 vapor.
STUFF AND BURN. A situation in which the charging rate is greater than
burning rate of the incinerator.
-------
THERMOCOUPLE. A thermoelectric device used to measure temperatures.
TRANSMISSOMETER. A monitoring device used to measure combustion gas
opacity.
UNDER-FIRE AIR. Combustion air which enters the fuel bed from orifices in
the hearth.
VAPOR."* The gaseous form of substances that are normally in the solid or
liquid state and whose states can be changed either by increasing the
pressure or by decreasing the temperature.
VIEW PORT. Sealed glass ports for observing the combustion chamber during
operation.
VOLATILE MATTER. That portion of waste material which can be liberated
with the application of heat only.
WET BULB/DRY BULB. Wet bulb temperature is indicated by a wet bulb
psychrometer and dry bulb temperature is measured by an accurate
thermometer. Together, they provide a measure of relative humidity.
REFERENCES FOR GLOSSARY
*
1. Industrial Gas Cleaning Institute. Wet Scrubber Technology.
Publication WS-1, July 1985.
2. Industrial Gas Cleaning Institute. Fundamentals of Fabric Collectors
and Glossary of Terms. Publication F-2, August 1972.
3. Flue Gas Oesulfurization Inspection and Performance Evaluation.
EPA/625/1-85-019. October 1985.
4. U. S. Environmental Protection Agency, Control Techniques for
Particulate Emissions from Stationary Sources. Volume I.
EPA-450/3-81-005a. September 1982.
5. Brunner, C. R. Incineration Systems Selection and Design. Van
Nostrand Reinhold Company, 1984.
6. Cleaver-Brooks®. Operation, Maintenance, and Parts Manual—Pyrolytic
Incinerator. CBK-6826. September 1988.
-------
ADDITIONAL READING
-------
Additional Reading
Medical Waste
U. S. Environmental Protection Agency. EPA Guide for Infectious Waste
Management. EPA 530/SE-86-014. (NTIS PB 86-199130). U. S EPA Office of
Solid Waste. May 1986.
Incineration/Combustion
U. S. Environmental Protection Agency. Hospital Waste Combustion Study-
Data Gathering Phase. EPA 450/3-88-017. December 1988.
Brunner, C. Incineration Systems Selection and Design. Van Nostrand
Reinhold. 1984.
Beard, J. T., F. A. lachetta, and L. V. Lillelehet. APTI Course 427
Combustion Evaluation, Student Manual. EPA 450/2-80-063. U. S. EPA*Air
Pollution Training Institute. February 1980.
Beachler, D. S. APTI Course SI:428A, Introduction to Boiler Operation,
Self Instructional Guidebook. EPA 450/2-84-010. U. S. EPA. December
1984.
Air Pollution Control
U. S. Environmental Protection Agency. Operation and Maintenance Manual
for Fabric Filters. EPA 625/1-86/020. June 1986.
U. S. Environmental Protection Agency. Operation and Maintenance Manual
for Electrostatic Precipitators. EPA 625/1-85-017. September 1985.
U. S. Environmental Protection Agency. APTI Course SI:412B, Electrostatic
Precipitator Plan Review—Self Instructional Guidebook.
EPA 450/2-82-019. July 1983.
Joseph, J., and 0. Beachler. APTI Course SI:412C, Wet Scrubber Plan
Review, Self-Instructional Guidebook. EPA 450/2-82-020. U. S.
Environmental Protection Agency. March 1984.
Beachler, D. S. APTI Course SI:412, Baghouse Plan Review. U. S.
Environmental Protection Agency. EPA 450/2-82-005. April 1982.
Miscellaneous
U. S. Environmental Protection Agency. Continuous Air Pollution Source
Monitoring Systems Handbook. EPA 625/6-79-005. June 1979.
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TECHNICAL REPORT DATA
. lease reaa instructions on me reverse oerore cumntennfi
EPA 450/3-89-003
3. RECIPIENT'S ACCESSION NO.
I. TITLE AND SUBTITLE I
Hospital Incinerator Operator Training Course-
Volume I Student Handbook
5. REPORT DATE
' Marrh 1QPQ
,6. PERFORMING ORGANIZATION CODE
NeoJicht, R. M.; Chaput, L. S.; Wallace, D. D.;
Turner, M. B.; Smith. S. G.
3. PERFORMING ORGANIZATION REPORT NO
ION NAME ANO ADDRESS
Midwest Research Institute
401 Harrison Oaks Boulevard, Suite 350
Gary, North Carolina 27513
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-4395
68-08-0011
2. SPONSORING AGENCY NAME ANO ADDRESS
U. S. Environmental Protection Agency
Control Technology Center
Research Triangle Park, N. C. 27711
13. TYPE OF REPORT ANO PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
JOTES
James Eddinger, Office of Air Quality Planning and Standards
Justice Manning, Center for Environmental Research
Vlume X of
training course for operators of
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