EPA-600/2-78-017
February 1978
Environmental Protection Technology Series
EVALUATION OF THE
REFUSE MANAGEMENT SYSTEM AT THE
JERSEY CITY OPERATION BREAKTHROUGH SITE
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-600/2-78-017
February 1978
EVALUATION OF THE REFUSE MANAGEMENT SYSTEM
AT THE JERSEY CITY OPERATION BREAKTHROUGH SITE
by
Jack Preston Overman and Terry G. Statt
Hittman Associates, Inc.
Columbia, Maryland 21045
Contract No. 68-03-0094
Project Officer
Robert A. Olexsey
Wastewater Research Division
Municipal Environmental Research Laboratory
Cincinnati , Ohio 45268
This study was conducted
in cooperation with
Office of Policy Development and Research
Division of Energy, Building Technology, and Standards
U.S. Department of Housing and Urban Development
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental
Research Laboratory, U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the
contents necessarily reflects the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation
for use.
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FOREWORD
The Environmental Protection Agency was created because of
increasing public and government concern about the dangers of pol-
lution to health and welfare of the American people. Noxious air,
foul water, and soiled land are tragic testimony to the deteriora-
tion of our natural environment. The complexity of that environ-
ment and the interplay between its components requires a concen-
trated and integrated attack on the problem.
Research and development is that necessary first step in
problem solution and it involves defining the problem, measuring
its impact, and searching for solutions. The Municipal Environ-
mental Research Laboratory develops new and improved technology
and systems for the prevention, treatment, and management of
waste-water and solid and hazardous waste pollutant discharges
from municipal and community sources, for the preservation and
treatment of public drinking water supplies, and to minimize the
adverse economic, social, health, and aesthetic effects of pollu-
tion. This publication is one of the products of that research; a
most vital communications link between the researcher and the user
communi ty.
This report describes the operation and economics of the
pneumatic trash collection system at the Department of Housing and
Urban Development's Operation Breakthrough site at Jersey City,
New Jersey. The information in this document should be extremely
useful to decision makers in planning future high population
density residential complexes.
Francis T. Mayo, Director
Municipal Environmental
Research Laboratory
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ABSTRACT
This study evaluates the solid waste management system at
the Jersey City Operation Breakthrough site and assesses the eco-
nomic and technical practicality of the system application for
future residential communities. The installation was the first
pneumatic trash collection system (PTC) used to collect residen-
tial refuse in the U.S. The annual cost for the PTC system,
$120,021 to collect 248 tons of refuse, ranged from 160 to 460
percent more expensive than conventional systems, but would be
cost-effective if operated at design capacity. Over an eighteen
month monitoring period the PTC system was operable only 54 per-
cent of the time, had a 50 percent probability of failure within
16 hours or 15 cycles of operation. Following failures, probabili-
ties of being again operable were 50 and 83 percent within 3.4
and 24 calendar hours, respectively. The main transport line,
programmer, discharge valves, control panel, vertical trash chutes,
and compactor caused 88 percent of all system malfunctions, 94
percent of total downtime, and 91 percent of all repair man-hours.
Design recommendations are presented that could increase system
availability to about 86 percent. Additionally, recommendations
are made for use in future residential complexes. In comparison
with conventional systems, the PTC system has as benefits reduced
labor costs, the non-appearance of rodents and vermin, and the
elimination of odor, litter, and collection noise. Additionally,
the refuse collection system was completely automatic, except for
final disposal of site refuse.
The report is submitted in partial fulfillment of Contract
Number 68-03-0094 by Hittman Associates, Inc., was prepared for
the Environmental Protection Agency9 was sponsored by the Office
of Policy Development and Research, Division of Energy, Building
Technology, and Standards, Department of Housing and Urban
Development, and the work was performed from December 1971
through May 1977.
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CONTENTS
Foreword i i i
Abstract iv
Figures v i i
Tables xiv
Abbreviations, Converstion Units xvii
Acknowl edgment xvi i i
I Intro duct ion 1
II Conclusions 13
III Recommendations 23
IV Data Collection 29
V Data Evaluation and Analysis 113
References 175
Appendices
A. Test Plan for Measurement of Total Airborne
Particulates Generated by the Pneumatic
Trash Collection System 177
B. Test Plan for Measurement of Total Airborne
Viable Particles Generated by the Pneumatic
Trash Collection System 184
C. Test Plan for Characterization of the Solid
Waste Conveyed by the Pneumatic Trash
Collection System ] 33
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CONTENTS (Continued)
D. Test Plan for Characterization of the Weekly
Load Profile for the Pneumatic Trash
Collection System 1 9"1
E. Test Plan for Determination of the Load
Capacity for the Pneumatic Trash Collection
System 193
F. Test Plan for Determination of the Power
Consumption for the Main Exhausters for the
Pneumatic Trash Collection System 195
G. Test Plan for Determination of an Optimal
Scheduling for the Pneumatic Trash
Col lection System 1 97
H. Test Plan for Measurement of the Noise Levels
Attributed to the Pneumatic Trash Collection
System 200
I. Test Plan for Determination of the Service Life
for the Pneumatic Trash Collection System 202
J. Calculations for the Regression Line for the
Relationship Between Transport Velocity and
Density 207
K. Calculations of the Service Life for the Main
Transport Line.. 210
L. Calculations of the Service Life for the
Discharge Valves 212
M. Calculations of the Energy Usage for the
Pneumatic Trash Collection System 216
N. Calculations for the Cost Projects for the
Pneumatic Trash Collection Systems and
Three Conventional Alternative Systems 217
VI
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FIGURES
Number Page
1 Jersey City Operation Breakthrough site arrange-
ment showing location of PTC equipment 7
2 A persepective view of the main components in the
PTC system 10
3 Central control panel for the PTC system 31
4 One sample page in the daily log book 33
5 A typical malfunction report 34
6 Daily number of completed cycles for the PTC System
from July 1, 1974 to December 31, 1975 39
7 PTC system availability based on automatic
operations 40
8 PTC system availability based on combined operations
(automatic and manual mode cycles) 41
9 Sampling of airborne particulates at the collection
hopper by a high volume sampler 46
10 Sampling of airborne particulates of the system
exhaust air by a high volume sampler 46
11 Sampling of airborne particulates in ambient air
by a high volume sampler 47
12 Viable particle sampling of the collection hopper
air 49
13 Viable particle sampling of ambient air 49
14 A typical stage from the viable particle sampling
test after the incubation period showing colonies... 50
15 Sample of refuse being collected during the solid
waste characterization test 50
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FIGURES (Continued)
lumber
16 Sieve used to separate the refuse 52
17 Refuse was manually sorted for the solid waste
characterization test 52
18 Platform and equipment used to weigh refuse for
load profi1e test
59
19 One sample of refuse weighed during the load
profile test ........................................ 59
20 Averaged weekend and weekday demand profiles of
collected refuse by the PTC system .................. 61
21 Test samples of 5,10,15 and 20 pound bundles of
newspaper successfully conveyed by the PTC system
during the load capacity test ....................... 63
22 Test samples of 30 pound dry and 13.5 pound wet
bundles of newspaper successfully transported
by the PTC system during the load capacity test ..... 63
23 Two feather pillows, cardboard boxes, and plastic
bags filled with loose newspaper successfully
transported by the system during the load
capacity test ....................................... 64
24 Test samples of rags, cans, wood blocks, and glass
bottles successfully collected by the PTC system
during the load capacity test ....................... 64
25 Wood Blocks used to simulate high density loads
during the load capacity test ....................... 65
26 Original interior surfaces of the test section of.
the main transport line ......................... *. ... 74
27 A section of transport line in the CEB showing the
two test sections ................................... 76
28 A sample of the formations of rust and scale which
were removed from the interior test sections of
the main transport line during the initial
characterization period ............................. 76
vm
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FIGURES (Continued)
Number Page
29 Wear path along the straight section of the main
transport line before washing 77
30 Wear path along the straight section of the main
transport line after washing 77
31 Meta11ographic view of a cross section of the
bottom interior surface for the straight test
section 73
32 Metal 1ographic view of a cross section of one side
of the interior surface for the curved test
section 78
33 Location of wall thickness reading measurements on
the straight and curved test sections 80
34 Metallograph view of the surface condition of the
teflon seal at the Shelley A discharge valve 79
35 Discharge valve at Shelley B East showing the
teflon seal 83
36 Section of the discharge valve plate at Shelley A 85
37 Section of the discharge valve plate at Descon
Concordia, showing dented areas 85
38 Surface impressions of discharge valve plates 86
39 Surface impressions of the discharge valve plates at
Descon Concordia (left) and Shelley A (right) 87
40 Metal 1ographic view of a discharge valve plate
showing a typical dent 88
41 Locations on the discharge valve plates used to
measure plate thickness 89
42 Top view of typical discharge valve showing the
locations of axes used in determining the
thickness of the discharge valve plates 90
43 Profiles of thicknesses of certain discharge valve
plates along the axis perpendicular to travel 91
44 Prifiles of thicknesses of certain discharge valve
plates along the axis of travel 92
ix
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FIGURES (Continued)
Number H
45 Layers of trash and other refuse that have
accumulated at the upper corners of the collec-
tion hopper after one month of operation 93
46 Layers of trash and refuse that have stuck to
the inside of the collection hopper door after
one month of operation 94
47 Upper southeast corner of the collection hopper
showing refuse buildup which is about 1-1/2
inches thick 95
48 Upper northeast corner of the collection hopper 95
49 Typical wall section of collection hopper 96
50 Portion of collection hopper wall about three feet
downstream from inlet section 96
51 Wall thickness measurements for a test section of
the collection hopper 97
52 Views of the dust collector base and the rotary
valve assembly 99
53 Filter bags inside the dust collector after 15 months
of operation with air shaker equipment and filter
globe valve not working 100
54 Section of neoprene wiper of the compactor after
18 months of operation 100
55 Surfaces of compactor and ram showing series of
fine parallel scratches 101
56 Meta1lographic view of compactor surfaces
magnified at 13.3x 102
57 Locations of points used to measure thickness
of compactor top 102
58 Cross-sectional view of compactor ram top 103
59 The compactor motor control center 104
60 One of the shattered pillow blocks used to move
containers 106
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FIGURES (Continued)
lumber Page
61 View of free motion rollers out of alignment .......... 106
62 PTC system reliability curve: Probability of
survival vs. active time ............................ 11?
63 PTC system reliability curve: Probability of
survival vs. scheduled cycles
64 PTC system downtime probability curve: Probability
that the system would be repaired vs. time .......... 120
65 PTC system probability of repair curve: Probability
that the system would be repaired vs.
scheduled cycles..... ............................... 121
66 PTC system probability of active repair curve:
Probability that the system would be repaired
vs. active repair time once a repair has begun ...... 122
67 Two wood pieces, curtain rods, and wire rack
successfully collected by the PTC system ............ 129
68 A mechanical adding machine 7.5 inches wide, 11
inches long, and 4 inches high which was
successfully transported by the PTC system .......... 129
69 One large piece of cardboard, about 3 feet by 4
feet, a shopping basket, a plastic pipe about
3.5 feet long, and a foot weight from a
weightlifting set, which were successfully
collected by the PTC system.... ..................... 130
70 The remains of a vinyl covered rocking chair which
were successfully collected by the PTC system ....... 130
71 Three cardboard boxes and a curtain rod which
created a chute blockage at Shelly A ............... . 132
72 A large, bulky cardboard box causing a typical
discharge valve blockage ................... . ........ 132
73 Transport velocity vs. density for refuse samples
used in the load capacity test.. .................... 133
74 A sample of the aerosal cans that were safely
collected by the PTC system ....... . ................. 135
XI
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FIGURES (Continued)
Number Page
75 High temperature alarm cable for a main
exhauster, similar to the one that ignited 139
76 Annual costs for the PTC system and three alter-
native conventional solid waste management
systems 153
77 Annual cost projections for the PTC system and
three alternative conventional solid waste
management systems 154
78 Annual collection costs for the PTC system vs.
amounts of refuse collected 156
79 Typical signs posted by the tenants to inform other
tenants to be more considerate when they dispose
their refuse 160
80 Site management regulations on the usage of the
PTC system 163
81 Refuse left at the charging stations which was
collected daily by site personnel 165
82 Discharge valve room at Camci, showing the amount
of litter in the room 166
83 Bulk solid waste left in the compactor room, even
though an open-top 25 cubic yard container was
provided for this waste 166
84 Refuse scattered at the discharge valve rooms at
Descon Concordia and Camci during period of
prolonged system downtimes 168
85 Bag placed at base of storage section at Shelley A
to collect refuse during prolonged system downtime..169
86 A typical chute charging station filled with refuse
during a prolonged system malfunction 169
87 One charging station at the deck of Descon Concordia,
showing how the design preserves site aesthetics....173
88 Bulk waste left daily outside Shelley A to be picked
up by site personnel 173
xii
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FIGURES (Continued)
Number P^age
89 Bulk waste left daily outside Camci to be
collected by site personnel................... -174
90 A workman with a small cart about 4' x 4' x 4'
in size used for collecting refuse.................. 174
xi n
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TABLES
Number £*£
1 Demographic and Solid Waste System Descriptive
Data for the Jersey City Operation Breakthrough
Site 8
2 Detailed Description of PTC System Components 9
3 Data Acquisition System Used to Monitor the PTC
System 30
4 Monthly .Weight Data of Solid Waste Conveyed by
the PTC System 36
5 Distribution of Automatic and Manual Mode PTC
System Cycles 37
6 Daily Schedules for Cycling the PTC System from
July 1, 1974 to December 31, 1975 38
7 History of Significant Events of the PTC System 42
8 PTC Monthly System Availability in Terms of
Scheduled versus Completed Automatic Cycles from
July 1, 1974 to December 31, 1975 43
9 Concentrations of Total Airborne Particulates 43
10 Viable Particle Concentrations 51
11 Composition by Weight of Refuse Samples from *
Februrary 24 Through 28, 1975 54
12 Composition by Weight of Refuse Samples Collected
from June 23 Through 27, 1975 55
13 Composition by Weight of Refuse Samples Collected
from January 5 Through 9, 1976 56
14 Density of Solid Waste Sampled 57
15 Moisture Content of Solid Waste Sampled 58
xi v
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TABLES (Continued)
Number Page
16 Results of the Load Profile Test 60
17 Density of Test Loads 62
18 Transport Velocity of Test Loads Through the
PTC System 66
19 Results for the Main Exhauster Power Test 67
20 Scheduled Cycle Times Selected for PTC Operation
During Optimization Test From October 31, 1975
to December 17, 1975 69
21 OSHA Noise Level Standards for Industrial
Appli cat ions 70
22 Ambient and PTC System Noise Levels for Discharge
Valve and Adjacent Public Rooms 71
23 Ambient and PTC System Noise Levels for Major
System Components 72
24 Weight Data of the Test Sections of the Main
Transport Line 75
25 Wear Measurement Results for the Straight Test
Section of the Main Transport Line 81
26 Wear Measurement Results for the Curved Test
Section of the Main Transport Line 8?
27 Distribution of Charging Station Problems After
Eighteen Months of Service 1C7
28 Actual Costs of Solid Waste Management System at
the Jersey City Operation Breakthrough Site 110
29 Annual Labor Costs to Operate the PTC System 109
30 Component Criticality Ranking Based on 18-months
of Calendar Time 124
31 Analysis of Critical Component Failures 125
32 Annual Reliability and Maintainability for the
PTC System Using Improved Components 127
xv
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TABLES (Continued)
Number Page
33 Estimated Amount of Solid Waste Which Could be
Collected for Recycling From the PTC System.... 137
34 Description of Solid Waste Management System
Alternatives A and B 143
35 Site Manpower Requirements for System Alternative A...144
36 Site Manpower Requirements for System Alternative B...146
37 Description of Solid Waste Management System
Alternative C 147
38 Site Manpower Requirements for System
Alternative C 148
39 Annual Cost for the Refuse Collection System
Al ternati ve A , -149
40 Annual Cost for the Refuse Collection System
Alternative B 1 50
41 Annual Cost for the Refuse Collection System
Alternative C 151
42 Comparative Annual Costs for the PTC System and
Three Conventional Solid Waste Management
Systems 152
43 Population Distribution of Residents 158
44 Extent of Resident Participation in Separating
Sol id Waste .1 59
45 Resident Evaluation of PTC System Adequacy... 161
46 National Ambient Air Quality Standards for
Particulate Matter 170
47 Results for Total Airborne Particulate Matter
Sampling Tests 170
48 Results for Viable Particle Concentration
Sampling Tests .171
xvi
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ABBREVIATIONS
SFA
SFD
MFLR
MFMR
MFHR
PTC
CEB
OSHA
single-family attached dwelling units
single-family detached dwelling units
multifamily low-rise dwelling units
multifamily medium-rise dwelling units
multifamily high-rise dwelling units
pneumatic trash collection
Central Equipment Building
Occupational Safety and Health Administration
1 foot
1 cubic yard
1 cubic foot
1 foot/sec
1 pound
1 ton
1 pound/
cubic foot
CONVERSION UNITS
0.3048 meter
0.7646 cubic meter
0.0283 cubic meter
0.3048 meter/sec
0 . 4536 ki1ogram
907.2 kilogram
16.02 kilogram/cubic meter
xvn
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ACKNOWLEDGMENTS
The cooperation from Avac Systems, Inc., the design firm
of the system; Mr. Edward Herrmann, plant engineer for Gamze,
Korobkin, and Caloger, Inc.; Ms. Barbara Tillman, site manage-
ment; the private service contractor; and site residents was
greatly appreciated. Without their assistance and enthusiastic
support, this study could not have been successfully completed.
Special thanks are extended to Mr. Jerome H. Rothenberg of
HUD for his guidance and assistance as well as to the program
personnel of EPA who include Messrs. Leland Daniels, Patrick
Tobin, and Robert A. Olexsey.
xvm
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SECTION I
INTRODUCTION
BACKGROUND
The Department of Housing and Urban Development
Operation Breakthrough Program is involved in the
demonstration of innovative building and design con-
cepts for residential communities. As part of this
program, a pneumatic trash collection (PTC) system was
installed at the Jersey City Operation Breakthrough
site in conjunction with a total energy system. The
installation is the first time a PTC system has been
installed in a residential complex in the United States
even though similar systems have been installed in
hospitals and other non-residential complexes. The PTC
system was installed to evaluate the performance and
effectiveness and to determine the feasibility for use
in future residential projects.
The average city dweller discards from one to four
pounds of refuse per day which means from three to
twelve pounds per day must be disposed from a dwelling
unit. For an apartment complex of 486 dwelling units,
the total daily refuse load is from 1458 to 5832
pounds. In most residential apartment complexes, the
refuse is disposed by each family or a building janitor
in a central collection point where it is stored until
picked up and hauled to a landfill or incinerator.
This method has the disadvantages of noise, odors, poor
sanitation, and possibly being labor intensive and
costly.
In some European countries where labor and mate-
rial costs are very high, automatic waste-collection
systems have been found more economical than conven-
tional systems in high-rise residential complexes.
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Because a PTC system had never been applied to
collect residential refuse in the United States, the
evaluation assumes the important task of determining
the practicality of the system and to guide the devel-
opment of such systems for use in larger scale projects
in the future.
This report presents the results of the evaluation
of the PTC system installed and operated in the Jersey
City Operation Breakthrough site. In addition a sepa-
rate report documents the results of a survey at the
site to determine resident and management acceptance of
the refuse system (Ref. 1). Those results are summarized
in this report. Also, an executive report is prepared
to summarize all work efforts and results of the PTC
system evaluation, the evaluation of refuse management
systems at Operation Breakthrough sites, and the refuse
system user acceptance surveys at eight of the nine
Operation Breakthrough sites.
BRIEF OPERATIONAL DESCRIPTION
When a resident at the Jersey City site has a full
wastebasket, it is carried to the disposal chute on the
resident's floor. The chute is at normal air pressure,
and there is no suction or blowing of trash. The
refuse falls until it lands on a horizontal plate at
the bottom of the chute. This plate is actually a
valve separating the chute from a horizontal steel pipe
20 inches in diameter running to the central collection
point. The horizontal pipe operates at a pressure of
between 8 and 9 pounds per square inch pressure which
is created by an air pump called an "exhauster." The
chute valves in the pipe network are opened one at a
time, automatically on a fixed schedule, and the
accumulated trash falls into the horizontal pipe and is
swept along to the central collection point in the
partially evacuated horizontal pipe by air which is
moving at about 60 miles per hour. The solid waste is
collected in the central collection hopper. There it
is compacted automatically and stored until trucks
carry the sealed containers to a Jersey City landfill.
The outside air is pulled into the system of horizontal
pipes through an intake valve by the exhauster. The
spent air from the exhauster is purified in high-
efficiency filters and released to the environment
through an exhaust plenum which acts as a silencer.
Although the stream of air in the pipes travels at a
mile a minute, it is not unreasonable to be concerned
about the ability of the system to transport bottles
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and other dense solids to the collection point. Experi-
ence indicates that any dense solids that separate from
lighter materials being carried along by the air are
ultimately shoved into the hopper by batches of lighter
material that coax them along even if the pipes slant
upwards as much as thirty degrees.
The projected operating costs for the PTC system
are expected to be lower than those for conventional
collection systems. Furthermore, the PTC system is
expected to be more convenient, quieter, and more sani-
tary than conventional collection systems.
STUDY OBJECTIVES
The study is a detailed evaluation of the per-
formance of the PTC system installed and operated at
the Operation Breakthrough site in Jersey City, New
Jersey. System performance is evaluated with respect
to achievement of design specifications. Overall
evaluations are made of the system performance with
respect to technical, economic, resident acceptance,
and environmental factors. Specific objectives are
discussed in the following paragraphs-.
Technical Evaluation Objectives
The technical objectives are to determine overall
system performance and to estimate the service life for
the system. To accomplish these objectives the fol-
lowing specific technical areas were investigated.
Reliability and Maintainability --
The system reliability and maintainability is
evaluated using operational data collected during an 18
month monitoring period. These data were analyzed to
determi ne:
• The availability of the system and the
probability that the system will be in
an operable mode at any time;
• The probability that the system can con-
tinue to collect refuse automatically
after the completion of a specified
number of cycles;
• The probable repair time required to
correct malfunctions;
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0 The effects of system malfunctions on
the collection service;
s The effects and probability of a major
system breakdown; and
• The reliability and maintainability
characteristics of the system and recom-
mendations for consideration in the
design of future PTC system applications.
Performance --
The system performance is evaluated to determine
the effectiveness of the PTC system in terms of:
• The ability to meet design criteria for
the refuse loads and economics for the
site;
• The ability to transport various shapes
and densities of refuse, including over-
size, overweight, and other bulky items;
« The capacity of the system for the design
loads, actual loads, and operating schedule,
including determination of the optimum
operating schedule;
• The ability to safely handle dangerous
materials;
he adaptability of the system to recycle
pecific solid waste classes;
The
s
The ability to recover valuable items
mistakenly placed in the system; and
1 u d i n g
dents*
safety
"he service life of the PTC system is determined
by evaluating the operational degradation and wear with
respect to service time over an 18 month period.
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Economic Evaluation Objectives
The economic evaluation objectives are to deter-
mine the capital, operational, and maintenance costs
and to compare these costs to design estimates. These
costs were obtained from the government and during the
18 month monitoring period. All costs are categorized
and evaluated to determine:
t Capital costs including initial procure
ment and installation, major components,
control instrumentation, and contingency
items costs;
• Operational and maintenance costs, including
labor, hauling and landfill, energy, mate-
rial, and other costs; and
t The annualized costs of owning and operating
the system on the basis of costs per dwell-
ing unit, capita, and ton of refuse disposed.
In addition, the PTC system annualized costs are
compared to the estimated costs of a conventional
system which might have been installed at the site.
Resident Acceptance Evaluation Objectives
The level of resident acceptance is evaluated in a
separate study (Ref. 1) and summarized. That study
summarized and determined:
t The type of resident at the site;
• The resident awareness of requirements of
the collection system; and
• The resident and management acceptance of
the PTC system.
Environmental Evaluation Objectives
The objectives of the environmental effects evalu-
ation are to determine:
• Sanitation effects such as litter, cleanli-
ness, odor, and presence of rodents and
vermin;
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• Air quality of the system, internal air
the exhaust air, including airborne par-
ti cu late s and viable particles;
• Noise levels produced by the refuse col-
lection activities compared to background
noise levels and acceptability to resi-
dential use of the system;
• Aesthetic qualities attributed to the
system; and
« Advantages of a reduced number of service
vehicles visits to the site to pick up and
dispose refuse.
SITE DESCRIPTION
The Jersey City Operation Breakthrough site, which
is located in a high density area, is composed of seven
buildings. The site plan -is presented in Figure 1.
The four residential buildings (by builder designators)
are Shelley A, Selley B, Descon Concordia, and Camci.
The other buildings are the Commercial Building, School,
and Central Equipment Building (CEB). All prime utility
equipment including PTC system equipment and a total
energy plant are located in the CEB. The Commercial
Building was completed during the evaluation period.
The school building was completed after the evaluation
period and therefore is not included. The solid waste
management system serviced the four residential build-
ings during most of the 18 month monitoring period.
Demographic and related data are reported in Table 1.
REFUSE SYSTEM DESCRIPTION
The pneumatic trash collection (PTC) system automati
cally collects all the solid waste generated at the site,
with the exception of bulky waste, and compacts this
refuse into sealed containers. A detailed description
of these components is presented in Table 2. The entire
operation of the system is regulated by a central control
panel. The fully ladened refuse containers are hauled
to a sanitary landfill by a pull-on container truck.
The following steps, as illustrated in Figure 2,
occur whenever refuse is collected by the PTC system.
« Refuse is disposed of by a tenant at a chute
charging station'. A station is usually lo-
cated near the elevator.
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Legend
O - Air Inlet Valves
O - Access Plates
• - Discharge Valves
O - Collection Hopper
® - Dust Col 1ector
.._ - Main Transport Line
L_
Commercial
Building
Central Equipment Building
Camci
Descon Concord i a
IShel1ey A
Shelley B
School
She!1ey A
South
FIGURE 1. Jersey City Operation Breakthrough site
arrangement showing location of PTC equipment.
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Table 1. DEMOGRAPHIC AND SOLID WASTE SYSTEM DESCRIPTIVE DATA
FOR THE JERSEY CITY OPERATION BREAKTHROUGH SITE
Site area is 6.35 acres.
00
Building
Shelley A
Shelley A South2
Shelley B3
Descon Concordia
Camci5
Number of Units
152 MFHR
-0-
40 HFMR
12 MFLR
24 MFMR
105 MFHR
153 HFHR
Number of.
Residents
456
-0-
150
326
323
Number of
Charging Stations
18
2
8
12
16
Number of
Discharge Valves
1
2
2
3
1
Units Per
Chute
152
-0-
20
47
153
Units Per
Charging Station
8.4
-0-
5.0
11.8
9.6
Residents Per
Charging Station
25
-0-
19
27
20
TOTALS
486 units
1255
56
It is assumed that there are l.S residents per bedroom. Site management states that total number of residents varies from 1200 to 1300 people.
This is a small shed with one charging station for yard waste and another charging station for tenant use.
One charging station is used by site personnel in addition to residents.
Tuo chutes are located cm the deck tevel, and are used by the tenants on the lowest floor at Descon Concordia and for recreational waste.
The first floor charging station is used by office tenants.
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Table 2. DETAILED DESCRIPTION OF PTC SYSTEM COMPONENTS
Component
AIR INLET
VALVE
DISCHARGE
VALVE
COLLECTION
HOPPER
DUST
COLLECTOR
MAIN
EXHAUSTER
PLENUM
COMPACTOR
VENT FAN
MAIN
TRANSPORT
LINE
Manufacturer and
Model Number
Envirogenics design
Envirogenics design
Envirogenics design
Mikropul Mi kro-Pulsaire
Dust Collector Model
Hoffman Centrifugal
Exhausters No. 77102
Envirogenics design
Dempster Brothers, Inc.
Model Number SP 38-42
Model Number 5K 145AL64
Industrial Exhauster by
Buffalo Forge Co.
Envirogenics design
Function
Allows air to enter the upstream ends of the
main transport 1 ine.
Isolates trash from main transport line so
that each station may be individually cycled.
Collects solid waste and separates the air
stream from it.
Removes particulate matter and viable par-
ticles from the air stream.
Provides vacuum to collect solid waste.
Muffles the noise produced by this system.
Compacts the collected refuse into a refuse
container.
Provides a negative pressure in the line and
in the vertical gravity chutes to prevent
odors from escaping into the residential
buildings .
Moves refuse from the vertical gravity chutes
to the equipment in the CEB.
Remarks
The valve is a butterfly valve that is pneumatically
operated.
Horizontal plate valve that is pneumatically operated.
A hopper screen is installed at the exit line from the
hopper to separate the air from the refuse. A hopper
gate over the compactor unit allows a vacuum to be
used in the system. After the main exhauster is off,
it opens to let refuse fall to the compactor unit.
The dust collector is a baghouse filter. At the base
there is a rotary valve to dispose dust particles into
a waste line.
Each exhauster is coupled to a 150 HP frame 3,600 RPM
induction motor. Provides 11,300 cfm of air at a
vacuum of 3.5 inches of mercury which is equivalent
to a 60 mph wind.
It is a chamber with the following dimensions: 3 ft
wide by 9.5 ft long by 18.5 ft high.
The hydraulically powered unit compacts the site refuse
into 25-cu yd containers.
Chute bypass valves have been installed at those dis-
charge valves located in the MFMR and MFHR buildings
to allow the vent fan to remove odors. These valves
are butterfly valves which are pneumatically operated.
This is a 20-inch nominal diameter low carbon steel
line with 1/2-inch wall thickness.
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EXHAUST
VENT
PULL-ON CONTAINER TRUCK
FIGURE 2. A perspective view of the
main components in the PTC system.
10
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MM
t
1 -
•—COMPACTOR
", -
- H, '. \..i
1 HM! U HIM MnilM
SIGN POSTED ON ALL CHARGING
STATION DOORS
TYPICAL CHARGING STATION (1 OF 56)
TEST SECTIONS OF THE MAIN
TRANSPORT LINE
TYPICAL DISCHARGE VALVE (1 OF 9!
BUILDING TRASH CHUTE
TYPICAL AIR
INLET VALVE
'1 OF 4)
FIGURE 2. (continued)
11
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• The refuse falls down a vertical chute and
rests at a storage section above the dis-
charge valve.
• One of the two main exhausters convey the
refuse through the main transport line to the
collection hopper.
t A dust collector, installed downstream of the
collection hopper, removes particulate matter
and viable particles.
• The refuse is then compacted into a sealed
container and hauled away by a pull-on con-
tainer truck to a sanitary landfill.
The PTC system is designed to be a quieter, more
sanitary, and odorless service as well as to be con-
venient for users. The main components are production
line units. This reduces capital costs and demonstrates
that this system can be designed and constructed with
readily available equipment. The system is ultimately
designed to reduce operating costs, manual labor, and
energy requirements and thereby to provide for a more
effective and efficient refuse collection service than
conventional systems.
The design load for this refuse collection system
was 1300 tons per year which is equivalent to 7125
pounds per day or 4.75 pounds per capita per day. The
solid wastes to be conveyed are classified as typical
residential waste of the following characteristics:
Composition by Weight
Paper
Wood
Plastic
Rags
Glass
Metal
Stone
Misc.
33.0%
0.3
6.8
6.4
16. 1
10.7
0.3
26.4
Density
5.6 Ibs/cu ft
89.7 kg/cu m
12
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SECTION II
CONCLUSIONS
This report presents the results of the technical
and economic data gathered during an 18 month monitoring
period of the solid waste management system at the
Jersey City Operation Breakthrough site. The overall
objective of this study is to assess the economics,
effectiveness, and feasibility of using PTC systems in
residential developments. General conclusions for the
PTC system were:
• The system was unreliable which caused exces-
sive downtimes and frequent service interrup-
tions;
• The system was over specified and designed
for the actual refuse loading capacities at
the site;
t The economics of the system, particularly
capital costs, were excessive;
• The residents and site management readily
accepted the system for its convenience and
the removal of many signs of refuse collec-
tion activities; and
0 The environmental effects including litter,
cleanliness, odor, and the presence of vermin
and rodents were effectively controlled and
site aesthetics were maintained.
Specific conclusions, based on the evaluation of this
study, are reported in the following areas:
• Technical,
t Economic,
• Resident Acceptance, and
• Envi ronmental.
13
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TECHNICAL CONCLUSIONS
Reliability and Maintainability
Using the operational data collected during an
18 month monitoring period, the availability of the PTC
system was calculated to be 54 percent. Design specifi-
cations stated that the system should be in an operable
mode around 97 percent of the time. Accordingly, the
system did not meet design expectations.
The probability that the system will successfully
operate (without failure) for a given number of cycles
decreases drastically as the number of cycles increases
There is a 50 percent probability of failure for 16
hours (15 cycles) of operation and a 90 percent prob-
ability of failures for 40 hours (37 cycles) of opera-
tion. The system exhibited 16 hours (15 cycles) mean
time between failures. This represents a very, very
low reliabi1ity.
Analysis of the data showed that total calendar
downtime increased with the extent of the system mal-
function. Fifty percent of the malfunctions were
repaired within three hours of total downtime while 10
percent of the malfunctions required 36 hours. How-
ever, 60 percent of the malfunctions were repaired
within one-half hour after repair work was actively
begun. Considerable amounts of downtime were attrib-
utable to the site personnels slow response in reacting
to system problems.
The design specifications called for all system
malfunctions to be repaired within 24 hours. The
operational data indicated that 16 percent of the
malfunctions required more than 24 hours for repairs,
which did not comply with the design criteria.
The probability of a major system breakdown is
directly related to the probability of a failure*with
six critical components. These components were the
main transport line, the programmer, the discharge
valves, the control panel, the vertical trash chutes,
and the compactor. They contributed to 88 percent of
all system malfunctions, 94 percent of all downtime, 89
percent of the total repair time, and 91 percent of
the total man-hours needed to effect repairs. It was
found that design improvements for these components
14
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The effects of system malfunctions were more pro-
nounced as the amount of time that the system did not
operate increased. Minor problems with sanitation,
litter, and odor were experienced with short downtime
periods. Whenever the downtime exceeded 24 hours, major
problems ensued. As a result of the PTC system being
inoperable for periods longer than 24 hours, an
alternative refuse collection service was required.
During these periods, the site personnel manually col-
lected refuse which was a highly labor-intensive
activi ty.
The prolonged downtime and the alternative collec-
tion service combined to cause a variety of problems
with litter, odor, and vermin. At times, these sanita-
tion conditions were so repulsive that the residents
complained to the site management.
Performance
Evaluation of the operational data indicated that
the PTC did meet the design capacity criteria for the
refuse loads; however, the loads at the site were only
about one-sixth of design load criteria. The observed
load was about 248 tons per year, while the design load
criteria was from 1300 to 1600 tons per year.
The design specifications stated that the system
must be able to collect refuse with densities ranging
to 50 pounds per cubic foot. Under normal operating
conditions, the system complied with these qualifica-
tions. The transport velocities for refuse of 10 and
50 pounds per cubic foot were observed to be about 50
and 27 feet per second, respectively. Additionally,
it was noticed that many overweight, oversize, and
other bulky items were collected without any problems.
At times, small refuse samples on the order of 100
pounds per cubic foot could be safely collected. The
refuse load, however, from the residences averaged
about two pounds per cubic foot.
15
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The operating schedule of 18 cycles per day more
than adequately handled the actual loads of the PTC
system. One reason for this was that, as mentioned
previously, the actual loads were only one-sixth of the
design loads. It was determined that for the actual
loads, the optimum operating schedule would be between
seven and nine cycles per day. The times for the
cycling of the system may vary due to daily, seasonal,
and other load factors.
The PTC system did have the ability to safely han-
dle some types of dangerous materials. Residents were
informed not to dispose of certain items which would be
hazardous to the system. Overall, these restrictions
were followed. In spite of these precautions, several
dangerous materials such as aerosal cans were placed
into the system. These cans were safely collected and
created no problems.
The investigations into the adaptability of the
system to recycle specific solid waste classes showed
that the system could be modified to do so without major
design changes and with reasonable success. The modifi-
cations would most likely be centered around the collec-
tion hopper. The quantities of recycled solid waste
annually could be about 148 tons of paper, 18 tons of
glass, 20 tons of metal, and 10 tons of plastic. This
would amount to about 196 tons, or 79 percent of the
annual refuse loading.
Observations from the monitoring program revealed
that valuable items mistakenly placed into the system
could be recovered, however, the probability of re-
trieving the item undamaged is small. The chances of
recovery and the effort required for recovery depend
upon the extent of system operations. By way of illus-
tration, the likelihood of rescuing an item mistakenly
placed in the system is good, if a collection cycle has
not been initiated. If, however, the cycle has been
completed, the possibility of obtaining the item is.poor
Therefore, care should be exercised to insure that
valuable items are not placed into the system.
The design specifications for the system called
for equipment to prevent component and plant failures,
service interruptions, fires, and personnel injuries.
Many of the PTC system safety features did not satisfy
these requirements. To cite two examples, a fire detec-
tion and sprinkler system failed to operate in one of
16
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the trash chutes when a fire occurred. Also, a high
temperature alarm cable for a main exhauster caught on
fire. These failures could be attributed to poor inspec
tion techniques. For the most part, the safety equip-
ment for the PTC system did prevent injury and property
damage.
The performance of the system deteriorated with
low room temperatures. Because components were located
in rooms that were not properly heated, and components
were built to operate properly at normal room tempera-
tures, component failures occurred. Most of these
failures were related to ice formation in the pneumatic
air actuation lines for the air inlet and discharge
valves, and the sluggish behavior of the hydraulic oil
used in the compactor.
The design specifications stated that the service
life of the PTC system should be 40 years. Through
observations of equipment degradation and the amount of
wear experienced during the first 18 months of opera-
tion, it was determined through wear measurements that
two system components did not meet this design cri-
teria. The main transport line would fail after 36
years of operation, while the compactor would fail
after 38 years. Whereas the compactor can be over-
hauled, a main transport line failure would create
severe and costly problems for many reasons:
Locating the failed section,
Excavating in order to reach the section,
Repairing and/or replacing the failed section,
Backfilling to cover the section, and
Providing an alternative refuse collection
service during the repair efforts.
ECONOMIC CONCLUSIONS
From the analysis of the data obtained during the
monitoring program, it was determined that the PTC
system was not, as stated in the design specifications,
cost effective. The total annualized cost of the system
(i.e., capital, operating, and maintenance) to collect
248.3 tons of refuse per year is $120,021. The annual
costs for three alternative conventional systems, which
might have been installed, to collect 248 tons of refuse
ranged from $26,231 to $74,699. Hence, the PTC system
was from 161 to 458 percent more costly than conven-
tional approaches.
17
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The costs for all four refuse collection systems
were projected to the year 1995. The annual cost in
1995 for the PTC system to collect 248.3 tons of refuse
is about $178,389. The corresponding costs for the
three conventional systems ranged from $66,782 to
$213,228. Thus, the annual cost for the PTC system was
about 0.84 to 2.67 times the costs for the conventional
systems.
As previously discussed, the PTC system was not
utilized to its design capacity. If the actual refuse
loads were six times the loads observed which would
then equal the design load criteria, the cost per ton
of refuse disposed by the PTC system would be from $99
to $116. The corresponding values for the three
alternative conventional systems would range from $104
to $341. Thus, the PTC system could be cost-effective
if the refuse loadings at the site approached the
design criteria of 1300 to 1600 tons of refuse per
year.
The capital costs of the PTC system, which totaled
$89,782 per year, accounted for about 75 percent of the
annual cost. The major capital expenditures were: (1)
the main transport line ($36,751 per year or 31 percent
of the annual cost), (2) the equipment space in the CEB
($15,451 per year or 13 percent of the annual cost),
and (3) engineering ($12,906 per year or 11 percent of
the annual cost). If measures were implemented to
reduce the capital cost of the PTC system, especially
with the main transport line, equipment space, and
engineering, the economics of the system would become
more attractive. Two such measures might be a lower
cost substitute for the main transport line and place-
ment of the line above ground.
RESIDENT ACCEPTANCE CONCLUSIONS
In general, it can be deduced that both residents
and management accepted the PTC system. The acceptance
was attributable to: the ease in using the system,
relatively few sanitation problems, the infrequent
visits by service vehicles, the removal of most of the
visible and audible signs associated with refuse
collection systems, the disappearance of vermin and
rodents, and to other advantages which were intrinsic
to the PTC system.
18
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Most of the residents were aware of the capabilities
of the system as well as the management's responsibility
for the operation of the system. About 98 percent of
the residents realized that the site management was
responsible for system operations, while 95 percent of
the residents were aware that large bulky waste would be
collected by contacting the site management. About 66
percent of the residents segregated their refuse into
many of the following categories: glass, bulky waste,
plastic, food waste, newspapers, and cans. However,
there was no policy implemented by the site management
for refuse segregation.
The site management accepted the PTC system but
felt that many problems associated with the system could
have been avoided if the tenants had used the system
properly. The management believed that the large main-
tenance effort could have been substantially decreased
if the tenants had not misused the system. However, as
resident-related problems occurred, the management took
immediate steps to correct the situation by reinforming
residents of the regulations for proper use of the PTC
system. Specific problems cited by the site management
i nclude:
• Residents breaking PTC system components by
forcing large, bulky wastes into the chute
door;
• Residents causing chute blockages by not
pushing refuse all the way down the chute;
• Residents leaving food wastes and moist
garbage on charging station floors or in
hallways and stairways; and
• Residents improperly wrapping refuse which
created unsanitary and unhealthy conditions
in discharge valve rooms, especially during
periods of operating problems.
ENVIRONMENTAL CONCLUSIONS
Examination of the data showed that the sanitation
effects such as litter, cleanliness, odor, and presence
of rodents and vermin were minimal. The effort of site
personnel, combined with attributes of the PTC system,
controlled litter and odor, and this cleanliness kept
the vermin population down. Furthermore, it should be
19
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noted, that during the entire monitoring program no
rodents were observed. The problems with litter,
odor, and vermin occurred only during prolonged system
downtimes, particularly during hot, humid weather.
Although the internal air of the system had
excessive levels of airborne particulates and viable
particles, the dust collector effectively removed the
matter such that the concentration levels in the
system exhaust air were consistently lower than the
levels in ambient air- Additionally, the concentra-
tion of airborne particles in the system exhaust air
never exceeded the Primary Standard for the National
Ambient Air Quality Standards for particulate matter
which was 3.28 x 10~5 grains per cubic feet. The
average values of total airborne particulate matter
was 13.74 x 10~b, 2.11 x 10~5 and 3.97 x 10'5 grains
per cubic foot for system internal air, system exhaust
air and ambient air, respectively. Thus, the system
exhaust air had lower levels of airborne particulates
than the ambient air which also complied with the
design criteria.
The viable particle concentrations for the system
internal air, system exhaust air, and ambient air were
7.3, 3.8, and 5.8 colonies per cubic foot, respec-
tively. The concentration of viable particles in the
system exhaust air was lower than in the ambient air.
This met the design criteria. In addition, the odor,
which was negligible, from the exhaust air was unde-
tected by the residents.
Analysis also showed that the noise produced by
the PTC collection activities was generally lower
than background noise levels. Much of the noise was
isolated from the residential areas by locating many
of the noise-producing components in the CEB. Further
more, the noise attributed to the PTC system never
exceeded OSHA requirements. As such, the effects of
the noise from the PTC system were limited and not.a
factor to residents.
The design of the system considered retaining the
site aesthetics; hence, most of the PTC system com-
ponents were located underground, behind walls, or in
the CEB. Those components that were visible were made
to blend into the site. These measures were most
effective in removing the visible signs of the PTC
system.
20
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Results from the monitoring program show that there
were definite advantages to a reduced number of service
vehicle visits to the site to pick up and dispose refuse,
These advantages included:
• Less noise,
• Less expense,
• Less tenant awareness,
• Less chance of accidents, and
• Freed service vehicles for other operations.
21-
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SECTION III
RECOMMENDATIONS
From observations made during the monitoring pro-
gram, the data collected, and the analyses of the data,
certain recommendations have been made that could improve
the efficiency, effectiveness, and economy of the PTC
system for future residential applications. These
recommendations basically fall into two broad categories,
namely design modifications and changes in daily system
operations.
One overall recommendation is that in order for the
PTC system to be most advantageous, it should be used in
high density residential communities and in other areas
where there are high refuse loadings. For these appli
cations, the PTC system could be the most economical
selection and provide higher levels of service than con-
ventional refuse collection systems.
DESIGN RECOMMENDATIONS
First and foremost, the design loads of refuse
should be carefully estimated to insure that the actual
loadings of a proposed site would justify the capital
costs of a pneumatic trash collection system. This can
be achieved by observing the refuse loads of similar
nearby residential complexes.
With the existing PTC system, there are no pro-
visions for (1) the collection of bulky refuse that
cannot be collected by the system, and (2) an alter-
native refuse collection service during prolonged sys-
tem downtimes. Therefore, future designs should con-
sider features to provide an efficient and effective
service to handle these provisions.
The design of the existing PTC system had many
problems which caused frequent interruptions to collec-
tion services and prolonged downtimes. Considerations
23
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for the design of future PTC system applications should
consider methods of resolving the following problems.
• Water infiltration and refuse blockages in the
main transport line.
• Design changes for the following system com-
ponents which were identified as critical for
proper system operations.
main transport line,
programmer,
discharge valves,
control panel,
vertical trash chutes, and
compactor.
• Blockages in discharge valves and chutes.
• Proper operation of the container handling
system.
• Proper heating of the rooms housing system
components.
These problems with the investigated PTC system were
due to design inadequacies and caused frequent system
malfunctions and prolonged downtimes.
The problem of water infiltration could be solved
by placing a water trap and pump at the lowest point in
the transport line. The pump should be able to handle
solids, such as refuse, as well as liquids.
The observed PTC system had six critical components
(the main transport line, the programmer, the discharge
valves, the control panel, the vertical trash chutes,
and the compactor) which created most of the problems
with the system operations. Improvements in the design
of these components could benefit in lower downtime
costs as well as providing for an improved collection
service.
As for refuse blockages in the line, the PTC sys-
tem was designed and built with access plates at stra-
tegic points along the line. These plates allowed
equipment to be placed in the line to remove the block-
ages. However, many of these plates were inaccessible-
Future design of PTC systems should consider placing
24
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more access plates at locations more convenient for the
equipment needed to remove blockages and no further
apart than thirty feet.
To alleviate problems with chute blockages, future
chutes should be designed without bends and restrictions,
and with larger cross-sectional areas. The addition of
energy absorbing baffles would also prevent refuse com-
paction when objects free fall on to loose refuse at the
bottom of chutes.
A variety of problems were experienced with block-
ages in the discharges valves. Future design should
consider either improvements in the discharge valves
themselves or alternative means for passing refuse from
the chutes to the main transport line. Positive suction
through the trash chute rather than gravity feed through
a discharge valve would improve this situation. Other
pneumatic conveying systems have successfully utilized
thi s approach.
Several problems were caused by litter in the dis-
charge valve rooms when site personnel removed litter
control devices. By removal of these devices, refuse
was not controlled when entering the discharge valves.
Because of this, problems arose with operating the dis-
charge valve plate. Further problems were caused by
site personnel in their attempts to clean up the litter
and repair the discharge valves. Future systems should
be designed so that litter and spillage from the chute
is more efficiently controlled.
The container handling system used at the site was
insufficient, basically due to two problems. One was
that the hydraulic lifts could not raise a fully loaded
refuse container. The other problem was that the power
assisted rollers frequently failed. Future PTC system
designs should make certain that the components for the
container handling system are properly sized to handle
the weight and stress of a fully loaded refuse container.
Unlike the PTC system that was investigated, future
systems should take into account the temperatures at
which system components best operate. Measures should
be incorporated so that the temperatures of rooms housing
system components can be maintained at the proper levels.
One of the main problems with the system, due to low
temperatures, was caused by using outside air for the
air inlet valves. This was accomplished by louvers
25
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through the exterior walls- Since the rooms where
components were located were not heated, cold air enter-
ing into the room through the louvers caused component
malfunctions through ice formation in pneumatic actuating
air lines.
The PTC system would appear to be easily modified
for recycling resource materials such as paper, plastics,
glass, and metals. Future system applications could con-
sider reclamation of these materials and determine the
suitability of this innovation. The economic benefits
of recycling would require analysis.
Discharge valve rooms should be designed to be more
accessible to site personnel. Better locations would
facilitate manual collection services when needed and
aid in proper maintenance activities.
One factor that contributed to excessive downtimes
with the Jersey City PTC system was the central control
panel. The control panel was located in the CEB along
with the total energy plant. Since the total energy
plant was operated by an outside party, they controlled
the access to the CEB. Thus, site personnel had access
to the building and the central control panel only when
this outside party was present at the site. When sys-
tem malfunctions occurred after daily work hours or on
weekends, site personnel could not gain access to the
control panel and thereby start repairs until the out-
side party arrived at the site. This situation caused
needless delays in servicing the system. Future PTC
systems should consider placing the central control
panel in a more convenient location for all authorized
s ite personnel.
New PTC systems should be designed with new and
improved alarm systems. Problems were observed with
the annunicator panel used to indicate malfunctioned
components. One problem was that some alarms did not
operate properly. Another problem which was experi-*
enced, was that the same series of alarm lights would
occur for different types of malfunctions. This situa-
tion contributed to extended system downtime because it
was not obvious by the alarm lights which component had
ma 1 functioned.
A problem that also caused long downtimes was that
since system components were dependent upon each other
for proper operations, when one component malfunctioned
26
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the annunciator panel would register this malfunction
for a second component. Here again, delays in repair-
ing the system were produced. The delays were due to
site personnel looking for malfunctions in properly
operating components. Alarm systems for future PTC
system applications should be designed so that the
problems experienced with the existing alarm system,
namely the annunciator panel, could be avoided.
When considering the service life for future PTC
systems, requirements for components should be investi-
gated more thoroughly. Analysis of the service life of
individual components for the system studied revealed
that the main transport line and the compactor would
not last for the full 40-year service life.
All of these design recommendations should be con-
sidered for future PTC systems. However, it is not
enough just to design a better system. Measures should
be taken to insure that these new systems meet the de-
sign requirements. This would entail detailed inspec-
tions of all system components, safety equipment, and
other related pieces. Furthermore, inspections and test
methods should be implemented to assure proper installa-
tion.
OPERATIONAL RECOMMENDATIONS
Pneumatic trash collection systems could operate
more effectively and with less wear and problems if
users are fully aware of the system capabilities and
their responsibilities. Many problems with the PTC
system at the Jersey City Operational Breakthrough site
were caused by misuse of the system by tenants. Pre-
cautions should be taken to insure that users not only
are aware of how to properly use the system, but do in
fact consistently do so.
Some measures that might be taken to achieve this
goa1 would be:
t A special clause in leases about PTC system
operation and use;
• The posting of signs at strategic places
promulgating system capabilities and use;
t An indoctrination as to proper system use; and
27
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• A different concept of operation, similar to
those used is successfully at some PTC
installations. At these installations only
site personnel are allowed to charge refuse
into the system and charging schedules are
set up to preclude overloading of chutes.
This concept could effectively be used at
Jersey City if site personnel collected and
charged refuse into the system.
Future PTC systems should also consider educating
personnel responsible for the system in its use, opera-
tion, and maintenance. Considerable money, time, and
effort can be saved when operating personnel fully
understand the system. This can be achieved by con-
ducting indoctrination and training classes, preparing
manuals, and by additional measures. This requirement
should be included in specifications and quotes for
future PTC system applications as part of the design
and construction contract.
Preventive maintenance programs for future PTC
systems should be a major concern. There was no pre-
ventive maintenance program at the site studied.
Therefore, there was no way of determining how many
problems could have been avoided. With a properly
planned and executed preventive maintenance program,
the service of the system would be improved. Further-
more, benefits of a good program would be savings in
time, labor, and money -
Although the PTC system is fully automated, the
human element is still a prominent factor. With better
educated system users and operators, the PTC system
could more fully attain its expectations.
28
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SECTION IV
DATA COLLECTION
Technical and economic data gathered during the
monitoring program of the PTC system are presented in
this section. Data were collected on a variety of
topics so that detailed analyses could be performed to
determine the system feasibility, economy, and effec-
tiveness.
MONITORING PROGRAM
The monitoring program was conducted during the
first 18 months of the PTC system operations which
dated from July 1, 1974 to December 31, 1975. Observa-
tions were made of the daily activities of the system
and associated functions as well. These functions
included the manpower required to assist the system
operations, the malfunctions of the system, the condi-
tions of PTC components, and the management and tenant
problems.
An instrumentation package to continuously monitor
the PTC system was developed and installed. Various
data acquisition components, (delineated in Table 3),
were placed at strategic points along the main trans-
port line (see the diagram in Figure 5). All data from
these components were recorded on analogue recorders in
an instrument panel located in the CEB.
In order to accurately record system operations,
instruments were chosen that would best monitor the
system performance (i.e., velocity and static pres-
sures, power consumption, and malfunction annunciator
signals). The following criteria were used to select
the monitoring instruments:
t Compatibility with the system design and con-
figuration as developed by the system sup-
pliers, site planners, and developers.
29
-------
Table 3. DATA ACQUISITION SYSTEM
USED TO MONITOR THE PTC SYSTEM
GO
O
Component
Air velocity tap
Differential pressure
transducer
Main exhauster
wattmeter transducer
Analogue recorder
Malfunction
annunciator points
Control panel
Pressure calibrator
Model Number
Pitot-Venturi
Flow Element
No. 88578
Model
No. 1151 DP
Model 13130A
Manufacturer
Taylor Instrument
Companies
Rosemount
Engineering
Company
Taylor Instrument
Companies
n of
span
0.2 % of
range
0.15% of
span
0.25% of
scale
0.1% sensitivity
Model 153S18
Taylor Instrument
Companies
Remarks
Measured the velocity of the air stream at each air
inlet valve and directly before the main exhausters.
Converted pressure readings at static pressure and
air velocity taps to electrical signals.
Provided by the National Bureau of Standards and
measured the instantaneous power of the main exhausters.
Seven strip chart recorders used to document any signals
from air velocity taps, differential pressure trans-
ducers, main exhauster wattmeter transducers, and
malfunction annunciator points.
Signal was provided from the malfunction annunciator
panel at the central control panel for the PTC system.
One separate instrument panel adjacent to the central
control panel that housed the analogue recorders.
Used as a primary standard to calibrate all differen-
tial pressure transducers.
-------
Ease of installation,
or replacement of the
transducer.
maintenance, and repair
instrument sensor and
t Reliability and accuracy for obtaining data
under field environment for over a full year
of operation.
t Ease of calibration and malfunction detection
to allow quick checking in the field to
identify error signals and recalibration for
drift.
As mentioned previously, the components of the in-
strumentation packaged are described in Table 3. The
control panel that housed the analogue strip chart
recorders is shown in Figure 3.
FIGURE 3. Central control panel for the PTC system.
The analogue recorders are in the cabinet on the far left.
31
-------
In addition to the instrumentation package, a
daily log book recorded the history of the PTC system
activities. Particular problems with the system were
cataloged in malfunction report forms. Samples of a
page in the daily log book and a malfunction report
form are shown in Figures 4 and 5, respectively.
Basically, the monitoring program investigated the
PTC system reliability, maintainability, and performance
by collecting data on:
• Weight characteristics,
• Daily operations,
• Significant events, and
0 Ava ilabi1ity.
Weight Characteristics
In order to determine the quantity of refuse col-
lected by the system, the weight of this refuse was
measured. This was achieved by the following process.
The full refuse container from the compactor was loaded
onto a truck and taken to a sanitary landfill. The
truck was weighed before and after the disposal of site
refuse. The weight differential was the amount of
refuse conveyed by the PTC system.
The data for the amount of the refuse conveyed by
the PTC system during the monitoring program are pre-
sented in Table 4.
Daily Operations
The PTC system was scheduled to operate at various
numbers of cycles per day; however, many of these
cycles were uncompleted due to the following problems:
• System malfunctions,
• Loss of power from the Total Energy Plant,
• Construction activities, and *
• Other actions.
At times, manual cycles were conducted by site
personnel to effect certain repairs to the system and
to collect refuse during downtime periods. The dis-
tribution of completed cycles is presented in Table 5.
Table 6 presents the operating schedules for the PTC
system during the eighteen month monitoring period.
32
-------
on
FIGURE 4. One sample page in the daily log book.
33
-------
Malfunction Reporting Form
Serial Number
1. Date of malfunction 7* QJJUlflflfU 7 f
2. Time of malfunction ^f'OO C^/D
3. T y pe of m a If unction (Tip
a. Valve sticking
b. Chute blockage
c. Horizontal line blockage
d. Screen overload
e. Filter overload
f. Power outage
g. Blower Outage
Compactor breakdown
Other
4. Note position of malfunction on map sheet \s
5. Person at HA1 notified _ , time
6. Corrective action
a. Time maintenance personnel arrived ^\ '. *-/ Q Qff\
b. Number of persons used
C. Operation performed
..-J.-^,^,
an A am atf/wtih/: rid
Time malfunction cleare4 |(f)'.QQ
FIGURE 5. A typical malfunction report,
34
-------
DISCHARGE VALVES
0 CLEAN OUT
AIR
DL - DIFFERENTIAL PRESSURE LOO TAPS
VRL - VELOCITY PRESSURE RECORD/LOG TAPS
S.1L - STATIC PRESSURE RECORD/LOG TAPS
O SU - STATIC PRESSURE LOG TAPS
y AS-AIR SAMPLING TAPS
J2IL PRL --POWER RECORD/LOG TAPS
Jersey City Site
FIGURE 5. (continued)
-------
Table 4. MONTHLY WEIGHT DATA OF SOLID
WASTE CONVEYED BY THE PTC SYSTEM
Month Weight (pounds) Number of Containers
July1 1974 2
August 51,500 4
September 46,440 J
October 51,480 8
November 54,040 9
December 49,080 8
January 1975 47,780 5
February 36,380 4
March 42,960 4
April 48,240 4
May 48,220 4
June 43,100 4 3
July -0- -0-
August 36,140 3
September 52,140 5
October 46,060 4
November 46,100 4
December 49.480 _4
Total 749,140 78
The containers were not weighed during July 1974.
2
The site personnel collected and disposed bulk waste in the
compactor. A portion of the August 1974 weight data con-
tained the bulk waste.
3
A prolonged downtime period was experienced, and there were
no container changes during July 1975.
36
-------
Table 5. DISTRIBUTION OF AUTOMATIC
AND MANUAL MODE PTC SYSTEM CYCLES
Automatic Manual Combined
Time Interval Mode Mode Mode
Daily Basis 18 1 19
Annual Basis 6,512 440 6,952
Monitoring Period 9,768 660 10,428
(Observed Data)
Significant Events
The history of the PTC system performance is de-
picted in Figure 6. The significant events shown in
this figure are further described in Table 7. As is
clearly evident from these presentations,the system
experienced prolonged downtime periods which severely
limited collection service.
Availability
The data collected on the availability of the PTC
system have been presented in diagrams. These diagrams
graphically show, in intervals of two hundred scheduled
cycles, the ratio of completed cycles to scheduled
cycles. For the automatic mode, Figure 7, the system
availability averaged 53.6 percent. The system avail-
ability for automatic and manual modes, Figure 8,
averaged 56.6 percent. The system availability for
each month is presented in Table 8.
COMPONENT TEST PROGRAM
A test program was developed to characterize the
reliability, maintainability, and performance of the
major PTC system components. These results provide
detailed information necessary to evaluate the PTC
system for effectiveness.
The following experiments comprised the test pro-
gram:
• Sampling of total airborne particulates --
The relative air quality of the PTC system
was compared to the ambient air with respect
to dust content by measuring the particulate
concentration of system internal air, system
exhaust air, and ambient air. Test procedures
are given in Appendix A.
37
-------
Table 6 DAILY SCHEDULES FOR CYCLING THE PTC SYSTEM
FROM JULY 1, 1974 TO DECEMBER 31, 1975.
Dates:
Started
July 1, 1974
August 9
August 22
September
September
September
September 16
December
December 24, 1974
April 14
April 15
June 5
October 31
November 2
November 6
November 11
November 14
November 18
November
November 25
November 29
December 4
December 17
December 22
Ended Cycles/Day Time
August 8
August 21
September 12
13
14
15
December 22
23
April 13, 1975
June 4
October 30
November 1
November 5
November 10
November 13
November 17
November 23
24
November 28
December 3
December 16
December 21
December 31, 1975
14
Nonel
14
52
142
112
14
21
30
21
18
17
4
7
7
9
24
15
10
7
15
7
11
15
7 a.m. to 8 p.m.
7 a.m. to 8 p.m.
7 a.m. to 8 p.m.
7 a.m. to 8 p.m.
7 a.m. to 8 p.m.
7 a.m. to 8 p.m.
7 a.-m. to 8 p.m.
7 a.m. to 6 p.m.
7 a.m. to 10 p.m.
7 a.m. to 10 p.m.
7 a.m. to 11 p.m.
7 a.m. to 11 p.m.
7 a.m. to 8 p.m.
7 a.m. to 11 p.m.
7 a.m. to 10 p.m.
7 a.m. to 11 p.m.
1 a.m. to 12 p.m.
7 a.m. to 9 p.m.
8 a.m. to 10 p.m.
8 a.m. to 9 p.m.
8 a.m. to 10 p.m.
«
8 a.m. to 9 p.m.
8 a.m. to 11 p.m.
8 a.m. to 10 p.m.
A fi/.imL failure occurred in the Total Energy System, and the PTC system
uar,
-------
Major A
Events 1
July
August
September
* A A
4 56
December
A A A
e 9 10
CO
ID
lf
January
A
ll
J
February
11 12
A
13
A tA
14 116
Apri I
May
20.
10.
I ll
II
I
•
n 1
1
1
[
WI
i
I
July
Major •
Events '•
August
A
September
October
A A
23 24
November
A
FIGURE 6. Daily number of completed cycles for
the PTC system from July 1, 1974 to
December 31 , 1975.
-------
.05
.90 _
.65 _
.80 _
.60 _
.55 _
50 _
.45 _
.10-
.05 _
n
There were
9,763 cycles
in the mo n i-
tor i ng per 10
5 6
Nunher of Cycles x 103
FIGURE 7. PTC system availability based on automatic operations.
-------
.95-
.90'
.85-
.80-
.75-
.70-
n
.45-
.40-
.15-
.30-
Averaoe System
Ava flabi1i ty Mas 0. 57
Lr
LJ
P
There nere JO.J28
cycles in the nwmtonng
period
•* • *
—r~
10
Numbe r of Cycles
103
FIGURE 8. PTC system availability based on combined operations
(automatic and manual mode cycles).
-------
Table 7 HISTORY OF SIGNIFICANT EVENTS OF THE
PTC SYSTEM
Number ~~te
1 July 1, 1974
2 July 17, 1974
3 August 3, 1974
4 September 15, 1974
5 September 23, 1974
6 September 27, 1974
/ October 17 & 18, 19/4
i December 1, 1974
'i December 9, 1974
In December 13-19, 1974
1 i
1?
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Jdnuary 14-17, 19/b
January 30, 1975
February
March 5,
March 9,
March 11,
4-7, 1975
1975
1975
1975
June 23-24, 1975
July 7 to
August 8,
August 11
September
September
September
September
October 3
1975
to
3, 1975
1-3, 1975
3, 1975
4, 1975
, 1975
October 14, 1975
November
1975
December
December
December
16 & 17,
19, 1975
20, 1975
31, 1975
Description of Event
First day of PTC system operations and monitoring program
Problems develop with paper and plastic bags blocking hopper screen and reducing
system air flow.
Total Energy Plant experiences complete loss of power which is not repaired until
August 20, 1974. Water infiltration problems in the main transport line
develop during this period.
Total Energy Plant is shut down for two days, and PTC system is inoperative.
Main transport line blockage between Descon Concordia and Camri is noticed. PTC
service to residents in Camci is Impossible.
Total Energy Plant experiences complete loss of power during a PTC system
collection cycle.
NBS conducts load tests on Total Energy Plant and PTC system is turned off.
Fire in trash chute at Descon Concordia, and sprinkler system did not activate.
Tenant calls fire department to extinguish fire.
Main transport line blockage which started before September 23, 1974 is finally
cleared.
Installation of discharge valves at the Descon deck locations and a new hopper
screen at the collection hopper. PTC system is turned off.
Low ambient room temperatures create hydraulic oil flow problems for compactor.
High temperature alarm cable for main exhauster number 2 burns.
Low ambient room temperatures creates ice blockages in pneumatic activating air
Shelley A.
Total Energy Plant is down for two hours.
Programmer problems develop. Fixed September 3, 1975 which created severe
operating problems from March 23 to April 7, 1975.
Alarm goes off in Total Energy Plant during the night and site personnel turn off
main switches to exhausters.
Main transport line blockage is removed.
Power failure of Total Energy Plant and PTC system after severe lighting storm.
Daily starting problems with main exhauster and compactor, which are related to
programmer.
Main transport line blockage stops refuse collection system.
Defective power supply for programmer is replaced, and during test procedures the
main transport line blockage is removed.
Main transport line blockage is removed.
Total Energy Plant is shut down for 50 minutes.
Main transport line blockage is removed.
Main transport line blockage is removed.
Low room temperatures at Shelley A freezes pneumatic activating air lines for PTC equipment.
Hopper gate opens slowly and creates system malfunctions.
PTC system is turned off for 3 hours during the installation of PTC equipment at
the school, and final day of monitoring program.
42
-------
Table 8. PTC MONTHLY SYSTEM AVAILABILITY IN TERMS OF
SCHEDULED VERSUS COMPLETED AUTOMATIC CYCLES
FROM JULY 1, 1974 TO DECEMBER 31, 1975
Month
July 1974
August
September
October
November
December
January 1975
February
March
April
May
June
July
August
September
October
November
December
Scheduled
Cycles
434
241
408
427
420
569
929
837
921
698
558
514
527
527
510
512
371
365
Completed
Cycles
357
34
74
265
176
126
526
670
561
335
346
251
19
131
370
441
274
287
Availabili
(j.823
0.141
0.181
0.621
0.419
0.221
0.566
0.800
0.609
0.480
0.620
0.488
0.036
0.249
0.725
0.861
0.739
0.786
Total 9,768 5,234
Average Availability 0.537
43
-------
Sampling of viable particles -- Similar to
the previously described experiment, the
biological activity in the air of the PTC
system was determined by measuring viable
particles in the system air, system exhaust
air, and ambient air. Test procedures are
given in Appendix B.
Solid waste characterization -- The site
refuse, as conveyed by the PTC system, was
characterized by composition, density, and
moisture content. Test procedures are given
i n Appendi x C.
Load profile -- The refuse collected by the
PTC system was weighed for every cycle for an
entire week to determine peak loads, trends,
and usage patterns. Test procedures are pre-
sented in Appendix D.
Load capacity — The transport velocities of
test samples, varying in density, were mea-
sured to establish the densest loading which
could be collected successfully by the system.
Test procedures are given in Appendix E.
Main exhauster power consumption -- The
power consumed by the main exhausters during
typical operations was measured. Test pro-
cedures are presented in Appendix F.
i-jf
Optimum scheduling -- Modified operating
schedules were tested to investigate the
system performance for a reduced number of
daily cycles. Test procedures are given in
Appendix G.
Noise level measurements -- Noise levels
associated with the PTC collection activities
were compared to background noise levels.
Test procedures are reported in Appendix H.
Life cycle estimates -- Extensive wear,
weekly velocity, and static pressure tests
were conducted to predict the service life of
the PTC system. Initial characterization
tests were performed before the monitoring
program to determine the original
44
-------
condition of the system. Weekly veloctty and
static pressure tests were conducted to
observe the degradation of the system during
the monitoring program. Post monitoring period
characterization tests were performed to
determine the amount of wear experienced
during the program. The system components
investigated were the:
Main transport line,
Di scharge valves,
Collection hopper,
Dust col 1ector,
Compactor, and
Chute charging stations.
The test procedures are given in Appendix I.
Ai r Samp!ing Tests
Sampling of air pollutant levels for the PTC sys-
tem air and ambient air were performed on the following
dates :
• February 24 to 28, 1975,
• July 23 to 27, 1975, and
t January 5 to 9, 1976.
Seasonal affects were considered by conducting the
tests in summer and winter.
The tests for the total airborne particulates and
viable particles were conducted to observe air pollu-
tant problems attributed to the PTC system. The three
sampling locations used in these tests were:
• System air inside the collection hopper,
• System exhaust air at the exhaust vent, and
• Ambient air at a remote outdoor location.
The levels of total airborne particulates were mea-
sured by high volume samplers as depicted in Figures 9,
10, and 11. The exhaust air and ambient air were
sampled continuously. The system air inside the col-
lection hopper was sampled between PTC cycle operations.
The results for the particulate sampling tests are
reported in Table 9.
45
-------
FIGURE 9. Sampling of airborne participates
at the collection hopper by a high volume sampler
FIGURE 10. Sampling of airborne particulates
of the system exhaust air by a high volume sampler
46
-------
FIGURE 11. Sampling of airborne particulates
in ambient air by a high volume sampler.
The sampling of viable particles was conducted
with an Andersen 2000 six-stage sampler. An inde-
pendent laboratory performed the media preparation,
Figures 12 and 13 show
collection air and
typical stage after the
of the tests are pre-
incubation, and colony counts.
viable particle sampling of the
ambient air. Figure 14 shows a
incubation period. The results
sented in Table 10.
Refuse Characterization Tests
The site refuse collected by the PTC system was
characterized by composition, density, and moisture
content. These tests were carried out during the same
time periods as the air sampling tests. The refuse was
manually separated into the following ten categories:
Paper
Fi nes
i nc
Food ,
Metal
Plast
Glass
Tex t i
Wood ,
Rocks
Yard
(any refuse that passes through a one
h sieve),
1C,
ies,
, and
wastes.
i nto
1 7.
The
the
The
refuse was weighed in trash cans and sorted
ten categories as shown in Figures 15, 16, and
composition of the solid waste is reported in
47
-------
Table 9. CONCENTRATIONS OF TOTAL AIRBORNE PARTICIPATES
Date
Monday 2/24/75
Tuesday 2/25/75
Wednesday 2/26/75
Thursday 2/27/75
Friday 2/28/75
Average
Ambient Air
(10s x grains/cu ft)
2.51
3.56
5.38
4.05
4.11
3.92
Hopper Air
(105 x grains/cu ft)
4.73
4.73
4.73
4.73
4.731
4.73
Exhaust Air
(105 x grains/cu ft)
1.05
1.45
2.18
1.41
1.26
1.47
00
Monday 6/23/75
Tuesday 6/24/75
Wednesday 6/25/75
Thursday 6/26/75
Friday 6/27/75
Average
5.03
6.04
3.33
3.66
4.19
4.45
6.10
6.38
6.11
2.56
9.21
6.07
4.65
3.52
2.08
1.75
1.70
2.74
Monday 1/5/76
Tuesday 1/6/76
Wednesday 1/7/76
Thursday 1/8/76
Friday 1/9/76
Average
3.24
4.31
4.64
2.08
3.45
3.54
5.86
7.10,
130.00^
3.81
5.32
30.42
2.29
2.32
2.95
1.43
1.58
2.11
20ne filte^- paper was'used for the entire five day period.
Fine dust particles similar to green paint dye were in the collection
hopper uh-Lch may account for the high particulate level
-------
FIGURE 12. Viable particle sampling of the
collection hopper air.
r
FIGURE 13. Viable particle
sampling of ambient air.
49
-------
FIGURE 14. A typical stage from the
viable particle sampling test after
the incubation period showing colonies
>
FIGURE 15. Sample of refuse being
collected during the solid
waste characterization test.
50
-------
Table 10. VIABLE PARTICLE CONCENTRATIONS
Ambient Air Collection Hopper System Exhaust
Date (Colonies/cu ft) (Colonies/cu ft) (Colonies/cu ft)
Monday 2/24/75 0.8 3.9 1.5
Tuesday 2/25/75 0.7 4.2 0.5
Wednesday 2/26/75 3.2 3.9 3.3
Thursday 2/27/75 0.6 4.9 1.4
Friday 2/28/75 8^3 5_._4 4.9
Average 2.7 4.5 2.3
Monday 6/23/75 3.0 5.3 3.1
Tuesday 6/24/75 1.7 3.9 1.7
Wednesday 6/25/75 14.5 10.0 7.1
Thursday 6/26/75 20.6 19.3 4.9
Friday 6/27/75 10.2 3.0 12.4
Average 10.0 8.3 5.8
Monday 1/5/76 3.1 3.0 2.3
Tuesday 1/6/76 7.7 7.5 6.0
Wednesday 1/7/76 1.7 4.1 1.6
Thursday 1/8/76 1.3 2.7 1.0
Friday 1/9/76 9.1 27.9 5.7
Average 4.6 9.0 3.3
-------
FIGURE 16. Sieve used to separate the
refuse. All refuse which fell through
the sieve was classified as fines.
FIGURE 17. Refuse was manually sorted
for the solid waste characterization test
52
-------
Tables 11, 12, and 13. The density of the refuse
samples is shown in Table 14 and the moisture content
of the samples is presented in Table 15.
Load Profi1 e Test
The load profile test documented the daily demand
of the PTC system. It was conducted for one week from
September 26 to October 3, 1975. The weight of the
transported refuse for every cycle was recorded. A
platform was built to detain the refuse as the com-
pactor ram pushed it out of the compactor unit as shown
in Figure 18. The refuse was weighed as seen by the
method shown in Figure 19. The results are presented
in Table 16. The data for the first two days were
biased by water infiltration in the main transport
line.
The data show that there are two distinct load
profiles; one for weekdays and another one for the
weekend. These trends are shown graphically in Figure
20.
Load Capacity Test
Load capacity test was performed on June 9 and 10,
1975 and on December 2S 1975. The results of this
test determined the transport velocities of refuse
samples varying in density, and the maximum limit in
density for refuse that may be successfully conveyed by
the PTC system.
Two kinds of refuse samples were used in the
test. Low density loads simulated typical residential
solid waste. High density loads determined the upper
boundary in density of those items which could be
successfully conveyed. The elapsed time and density
53
-------
Table 11. COMPOSITION BY WEIGHT OF REFUSE SAMPLES COLLECTED FROM FEBRUARY 24 THROUGH 28, 1975
Category
Paper
Fines
Food
Metal
Plastic
Glass
Texti les
Wood
Monday
Weight
48.0 Ib
15.0
21.0
10.2
2.0
1.1
1.0
0.0
2/24/75
—
48.8
15.3
21.4
10.4
2.0
1.1
1.0
0.0
Tuesday
Weight
53.0 Ib
54.0
46.0
15.5
7.3
1.2
2.0
1.0
2/25/75
—
29.4
30.0
25.6
8.6
4.0
0.7
l.'l
0.6
Wednesday
Weight
114.0 Ib
28.0
22.0
6.3
5.2
3.0
9.5
1.0
2/26/75
JL
60.3
14.8
11.6
3.3
2.8
1.7
5.0
0.5
Thursday
Weight
78.4 Ib
36.2
22.3
17.3
5.5
1.0
5.5
0.0
2/27/75
—
47.2
21.8
13.4
10.4
3.3
0.6
3.3
0.0
Friday
Weight
56.6 Ib
31.8
17.8
10.9
6.2
0.0
1.1
0.0
2/28/75
JL
45.5
25.5
14.3
8.8
5.0
0.0
0.9
0.0
Five-Day
Weight
70.0 Ib
33.0
25.8
12.0
5.2
1.3
3.8
0.4
Average
JL
46.2
21.8
17.0
7.9
3.4
0.9
2.5
0.3
Totals
98.3
100.0
180.0
100.0
189.0
100.0
166.2
100.0
124.4
100.0
151.5
100.0
here were no rocks or yard waste in the refuse samples.
line total weight collected during the test period was 757.9 pounds.
-------
Table 12. COMPOSITION BY WEIGHT OF REFUSE SAMPLES COLLECTED FROM JUNE 23 THROUGH 27, 1975
01
en
Category
Paper
Fines
Food
Metal
Plastic
Glass
Textiles
Yard Waste
Monday 6/23/75
Weight I
171.4 Ib
59.4
31.5
18.2
11.5
10.7
8.3
0.0
55.1
19.1
10.1
5.9
3.7
3.4
2.7
0.0
Tuesday 6/24/75
Weight ':-.
143.1 Ib
57.3
32.8
17.7
11.1
8.5
3.3
0.0
52.3
20.9
11.9
6.5
4.1
3.1
1.2
0.0
Wednesday 6/25/75
Weight ';
199.1 Ib
42.5
28.5
20.7
7.8
8.3
10.0
0.0
62.8
13.4
9.0
6.5
2.5
2.6
3.2
0.0
Thursday 6/26/75
Weight %
173.0 Ib
34.3
38.4
15.0
9.2
23.8
6.5
0.0
57.6
11.4
12.8
5.0
3.1
7.9
2.2
0.0
Friday 6/27/75
Weight %
166.6 Ib
52.5
31.0
16.0
14.0
19.2
4.0
1.0
54.7
17.3
10.2
5.3
4.6
6.3
1.3
0.3
Five-Day Average
Weight "--
170.6 Ib
49.2
32.5
17.5
10.7
14.1
6.4
0.2
56.6
16.3
10.8
5.8
3.6
4.7
2.1
0.1
Totals2 311.0 100.0 273.0 100.0 316.9 100.0 300.2 100.0 304.3 100.0 301.2 100.0
ylheve were no rocks or wood in the refuse samples.
The total weight collected during the test period was 1505.2 pounds.
-------
Table 13. COMPOSITION BY WEIGHT OF REFUSE SAMPLES COLLECTED FROM JANUARY 5 THROUGH 9, 1976
en
01
Category
Paper
Fines
Food
Metal
Plastic
Gl ass
Textiles
Wood
Totals2
Monday
Weight
144.8 Ib
113.6
28.8
19.4
10.8
8.8
2.2
0.0
328.4
1/5/76
JL
44.1
34.6
8.8
5.9
3.2
2.7
0.7
0.0
100.0
Tuesday
Height
159.0 Ib
47.8
36.5
18.0
13.0
6.4
4.2
1.0
285.9
1/6/76
%
55.6
16.7
12.8
6.3
4.5
2.2
1.5
0.4
100.0
Wednesday
Weight
173.9 Ib
46.7
22.7
14.6
13.0
9.0
10.3
1.2
291.4
1/7/76
_?_
59.7
16.0
7.8
5.0
4.5
3.1
3.5
0.4
100.0
Thursday
Weight
90.2 Ib
40.0
19.6
12.2
3.8
2.8
4.1
1.7
174.4
1/8/76
%
51.7
22.9
11.2
7.0
2.2
1.6
2.4
1.0
100.0
Friday
Weight
128.0 Ib
48.1
35.5
17.6
9.2
10.7
10.1
0.0
259.2
1/9/76
%
49.4
18.6
13.7
6.8
3.5
4.1
3.9
0.0
100.0
Fi ve-Day
Weight
139.2 Ib
59.2
28.6
14.4
10.0
7.5
6.2
0.8
267.9
Average
_%_
52.0
22.1
10.7
6.1
3.7
2.8
2.3
0.3
100.0
~There wei>e no rocks or yard waste in the refuse samples.
The total weight collected during the test period was 13Z9.3 pounds.
-------
Table 14. DENSITY OF SOLID WASTE SAMPLED
Date
Weight of
Sample
Volume of
Sample
Dens i ty ,
(Adjusted;1
Monday 2/24/75
Tuesday 2/25/75
Wednesday 2/26/75
Thursday 2/27/75
Friday 2/28/75
Average
100.25 Ib
613.65
202.00
174.15
133.75
244.70
44.2 cu ft
210.8
75.3
72.3
_45_.2_
89.56
2.26 Ib/cu ft
2.91
2.68
2.41
2.95
2.73
1.13 Ib/cu ft
1.46
1.34
1.21
1.48
1.37
01
Monday 6/23/75
Tuesday 6/24/75
Wednesday 6/25/75
Thursday 6/26/75
Friday 6/27/75
Average
311.0
273.8
316.9
300.2
304.3
301.2
Ib
64
64
2 cu ft
2
2
76.2
88.7
76.2
3.53 Ib/cu
4.26
4.94
3.94
3.45
3.95
ft
1.77 Ib/cu ft
2.13
2.47
1.97
1.73
1.98
Monday 1/5/76
Tuesday 1/6/76
Wednesday 1/7/76
Thursday 1/8/76
Friday 1/9/76
Average
328.4 Ib
285.9
291.4
174.4
259.2
267.9
92.2 cu
88.2
76.2
48.1
68.2
74.6
ft
3.56 Ib/cu ft
3.24
3.82
3.63
3.80
3.59
1.78 Ib/cu ft
1.62
1.91
1.82
1.90
1.80
In the sample collection procedure, paper was packed into a container at about a 2 to 1 compaction ratio;
therefore, the density figures were adjusted to reflect the uncotnpacted condition.
-------
(Jl
Table 15. MOISTURE CONTENT OF SOLID WASTE SAMPLED
Weight Before Weight After Moisture
Date Drying Drying Content
Monday 2/24/75 5.25 Ib 3.37 Ib 35.8%
Tuesday 2/25/75 6.84 4.66 31.9
Wednesday 2/26/76 8.16 6.05 25.9
Thursday 2/27/75 7.43 5.11 31.2
Friday 2/28/75 7.62 4.60 39.6
Average 7.06 4.76 32.6
Monday 6/23/75 4.03 Ib 2.87 Ib 28.8%
Tuesday 6/24/75 5.46 4.12 24.6
Wednesday 6/25/75 5.09 3.29 35.3
Thursday 6/26/75 4.51 2.38 47.2
Friday 6/27/75 6.48 4.46 31.1
Average 5.11 3.42 33.1
Monday 1/5/76 6.56 Ib 4.62 Ib 29.6%
Tuesday 1/6/76 4.04 3.16 21.9
Wednesday 1/7/76 1.65 1.40 15.1
Thursday 1/8/76 3.70 2.63 28.7
Friday 1/9/7* 3.94 3.18 19.1
Average 3.98 3.00 24.6
-------
FIGURE 18. Platform and equipment used
to weigh refuse for load profile test.
HGURE 19. One sample of refuse
weighed during the load profile test
59
-------
Table 16. RESULTS OF THE LOAD PROFILE TEST
Time of
Cycle,
7 AM
8 AM
9 AM
10 AM
11 AM
12 Noon
1 PM
2 PM
3 PM
4 PM
5 PM
6 PM
7 PM
8 PM
9 PM
10 PM
1 1 PM
Daily
Total
Density
Density
(Adjusted)3
Friday2
9/26/75
64.0 Ib
85.2
84.8
144.1
162.1
226.8
160.2
163.1
121.4
1,211.7,
(1,72.2)'
9.37 lb/ft3
4.69 lb/ft3
Saturday
9/27/75
200.4 Ib
75.6
139.0
285.0
265.2
447.5
545.2
351.1
205.6
167.0
338.5
268.8
195.5
225.7
136.8
113.9
80.3
4,041.1
9.65 lb/ft3
4.83 lb/ft3
Sunday
9/28/75
111.0 Ib
18.3
110.5
202.4
152.5
120.4
204.6
156.2
137.5
134.0
109.5
135.7
166.2
146.6
99.6
119.3
126.4
2,250.7
5.«Tb/ft3
2.70 lb/ft3
Monday
9/29/75
133.4 Ib
40.1
43.9
57.4
211.1
239.5
160.8
69.9
62.4
104.4
71.3
98.6
122.5
112.2
131.5
126.8
76.0
1,861.8
4.94 lb/ft3
2.47 lb/ft3
Tuesday
9/30/75
138.0 Ib
21.9
197.4
79.3
36.3
48.0
66.7
60.4
102.3
102.7
71.0
78.2
121.5
177.8
125.8
75.0
75.3
1,577.6
5.04 lb/ft3
2.52 lb/ft3
Wednesday
10/1/75
71.9 Ib
51.8
143.9
109.3
32.5
76.0
66.9
78.4
32.3
72.8
81.7
115.2
134.4
124.4
126.8
99.1
81.6
1,499.0
4.85 lb/ft3
2.43 lb/ft3
Thursday
10/2/75
52.2 Ib
24.7
120.1
69.6
83.8
39.1
97.8
79.3
55.1
54.3
65.0
94.8
138.9
175.6
127.0
92.2
65.1
1,434.6
4.65 lb/ft3
2.33 lb/ft3
Friday
10/3/75
76.9 Ib
34.6
40.5
36.1
160.8
79.1
83.7
58.8
570.5 ,
(1,782.2)'
3.95 lb/ft3
1.98 lb/ft3
Average
112.0 Ib
38.1
113.6
119.9
134.6
149.9
175.1
122.0
94.2
102.9
117.4
133.6
148.7
169.9
129.7
112.8
89.4
2,063.9
5.86 lb/ft34
2.93 lb/ft3E
Total for Friday of 1,782.2 Ib is swr, of collection from 3 PM to 11 PM on 9/26/75, and collection from 'i AM to 2 PM on 10/3/75.
Moisture content of refuse collected from 6 PM on 9/26/75 to 'i PM on 9/27/75 was much higher than normal, probably due to
leakage into the transport pip9 from heavy rain on Friday, 9/26/75. Heights should be reduced by approximately SO percent to
account for the excess moisture.
In the sample collection procedure, paper uas packed into a container at about a 2 to 1 compaction ratio; therefore, the density
figures were adjusted to reflect the unccmpacted condition.
4 ?
The average density assumed a mean density figure for 9/26/75 and 10/3/75 of 6.51 lb/ft
^ T
~The average adjusted density assumed a riean density figure for 9/26/75 cnA 10/3/75 of 3.26 lb/ft .
-------
380-.
360-
340-
320-
300-
280
260-
240
•t— O
<— Q.
'200-
<<-
= TJ 140-1
O
-------
were measured for every test sample. Some of the test
loads, as shown in Figures 21 to 25, were the fol-
1owi ng:
Low density loads
loose newspaper
dry bundled newspaper
wet bundled newspaper
plastic trash bags
with newspaper
cardboard boxes
feather pillows
loose rags
loose cans
loose glass bottles
The densities of the test
Table 17. The results for the
Table 18.
High density loads
wood blocks
plastic trash bag with
wet rags
plastic jars with water
brick fragments
1 oads
tests
are
are
listed in
presented
i n
Main Exhauster Power Consumption Test
The electrical energy used by the main exhausters
was calculated by measuring the instantaneous power and
elapsed cycle time. The test was conducted on September
3, 1975 and December 15, 1975. The results are reported
in Table 19.
Table 17. DENSITY OF TEST LOADS
Description of test load
Balsa wood
White pine
Fi r
Walnut
Map! e
Bundled newspapers
Bundled newspapers
Wet rags
Plastic jar filled
Brick fragments
(dry)
(wet)
with water
about
Dens i ty
(Ib/cu ft)
8
23
30
39
47
25
46
43
62
100
62
-------
FIGURE 21. Test samples of 5,10,15, and 20
pound bundles of newspaper successfully
conveyed by the PTC system during the
load capacity test.
FIGURE 22. Test samples of 30 pound dry and 13.5
pound wet bundles of newspaper successfully
transported by the PTC system during the
load capacity test.
b3
-------
FIGURE 23. Two feather pillows, cardboard boxes, and
plastic bags filled with loose newspaper successfully
transported by the system during the load capacity test.
FIGURE 24. Test samples of rags, cans, wood blocks,
and glass bottles successfully collected by the
PTC system during the load capacity test.
64
-------
FIGURE 25. Wood Blocks used to simulate high density
loads during the load capacity tests. The kinds of
wood are balsa, white pine, fir, walnut, and maple.
The sizes range from 1" x 3" x 6" to 3" x 3" x 8".
Optimal Schedule Test
The optimal schedule test was conducted from
October 31, 1975 to December 17, 1975 to observe the
system performance during the operation of a reduced
number of schedule cycles. The PTC system was sched-
uled to operate an average of 18 cycles per day. If
the PTC system were able to perform satisfactory with
a fewer number of cycles, many benefits may be realized
These benefits include lower operating costs and pro-
longed component life.
65
-------
Table 18. TRANSPORT VELOCITY OF TEST LOADS THROUGH THE PTC SYSTEM
De_scri_ptjon_qf _Test_ Load
1. Loose crumpled newspapers (5 Ib)
2. Crumpled newspapers in plastic
bags (5 Ib)
3. Cardboard boxes:
#1 4-i/4"x4-l/4"x9"
#2 7"x7"x9"
#3 6-l/4"xl2"xl5"
4. Feather pillows:
#1
#2
5. Loose rags (50 Ib)
6. Loose cans (2 ft3)
7. Loose glass bottles:
n 25 Ib
n IP, ib
Elapsed Time from
DV- 3 to Hopper
Velocity
8.
9.
Wooden blocks:
balsa (3"x3"x3")
balsa (I"x3"x6")
balsa (2"x3"x6")
white pine (3"x3"x3")
fir (4"x4"x4")
walnut (3"x3"x8")
maple (3"x3"x3")
maple (3"x3"x5"j
maple (3"x3"x8")
Bundled newspapers (dry):
5 Ib
10 Ib
15 Ib
20 Ib
30 Ib
Bundled newspapers (wet):
13.5 Ib
Refuse in plastic bags:
//I
#?
Wet rags in plastic bag (30 Ib)
Plastic jar filled with water
14. Brick fragments
10
11.
10.5-13.5 sec
10.9
12.2
11.5
11.9
13.2
12.8
12.7-16.7
11.9-13.9
17.6-27.6
14.6-26.6
13.7
12.4
11.6
16.9
15.7
27.1
22.9
23.1
not transported
15.5
15.3
15.4
17.3
14.7
48.9-62.9 fps
60.6
54.1
57.4
55.5
50
51.5
39.5-52.0
47.5-55.5
23.9-37.5
24.8-45.2
48.23
53.22
56.91
39.15
42.04
24.48
28.86
28.87
42.6
43.1
42.9
38.2
44.9
32.6-42.8
41.2
36.8
39
37.7
34
35.1
26.9-35
32.3-37.
16.3-25
16.9-30
32.8
36.2
38.7
26.6
28.6
16.6
19.6
19.4
29.0
29.3
29.2
26.0
30.5
mph
.4
.8
.5
. 7
20.9
13.9
15.9
17.9
not transported
not transported
31.6
47.5
41.5
36.9
21.5
32.3
23.2
25.1
66
-------
Table 19. RESULTS FOR THE MAIN EXHAUSTER POWER TEST
Exhauster Number
Average
Energy
Used Per Cycle
minutes and seconds kilowatt?horsepower kilowatt hours
Average Cycle
Elapsed Time
Average
Power Per Cycle
Results for September 3, 1975
1
2
Average
4:57
4:57
4:57
109.53
109.69
109.61
146.88
147.10
146.99
9.04
9.05
9.05
Results for December 15,1975
1
2
Average
5:06
4:55
5:00
110.47
110.23
110.35
148.15
147.82
147.98
9.38
9.04
9.21
-------
The test schedules were determined by the results
from the load profile test. Every peak recorded in the
profile test was considered for a possible time for
cycling. There were nine test schedul es- generated, as
presented in.Table 20. The daily number of cycles
varied from 4 to 24 to demonstrate the system per-
formance for a range in schedules.
The performance of the PTC system was closely
observed during each test schedule. It was noticed
that many system malfunctions occurred during this
period which caused frequent service interruptions.
Some of these malfunctions were not related to the
cycling schedules, such as:
e Compactor failures,
0 Discharge valve blockages, and
• Control problems with discharge valves.
These problems severely prejudiced the test re-
sults, but one result is that the PTC system could not
perform satisfactory with a schedule of four daily
cycles. The system could possibly op-erate satisfactory
with a schedule ranging from seven to nine daily cycles,
however, the cycle times must be carefully selected.
It was observed that with a daily schedule of nine
cycles, refuse would back up in the vertical trash
chute at Shelly A beyond the first floor charging
station. Nevertheless, the PTC system was capable of
collecting the refuse without creating any problems.
Finally, with a daily schedule of 24 cycles, the PTC
system malfunctioned. Thus, it is apparent that many
problems with the system were independent of daily
cycle schedu1es.
Noise Level Measurements
The noise levels attributed to refuse collection
activities by the PTC system were compared to ambient
levels and to Occupational Safety and Health Administra-
tion (OSHA) standards. These OSHA standards are re-
ported in Table 21. The noise levels were measured by
a General Radio Company Permissible Sound Level Meter,
Type 1565-B. The noise levels for the discharge valve
rooms and adjacent public rooms are presented in Table
22. The noise levels for the PTC system components in
the CEB and for th.e pull-on container truck are pre-
sented in Table 23. The noise level measurements were
conducted on March 24 and 25, 1976.
68
-------
Table 20. SCHEDULED CYCLE TIMES SELECTED FOR PTC OPERATION DURING
OPTIMIZATION TESTS CONDUCTED FROM OCTOBER 31, 1975 TO DECEMBER 17, 1975
October 31 November 1 November 5 November 10 November 13 November 17 November 23 November 24 November 28 December 3 December 16
Cycle to to to to to to to to to to to
Number November 1 November 5 November 10 November 13 November 17 November 23 November 24 November 28 December 3 December 16 December 17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
7:00 AM 7:00 AH 7:00 AM 7:00 AM
12:00 Noon 10:00 10:00 9:00
3:00 PM 12:00 Noon 12:00 Noon 11:00
8:00 2:00 PM 1:30 PM 1 :00 PM
4:00 4:00 3:00
7:00 6:30 5:00
11:00 10:00 7:00
9:00
11:00
one cycle 7:00 AM
per hour
for 24 8:00
hours per
day 9:00
10:00
11:00
12:00 Noon
1:00 PM
2:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
8:00 AM
10:00
12:00 Noon
1:00 PM
2:00
4:00
5:00
6:00
8:00
10:00
8:00 AM 8:00 AM 8:00 AM
10:00 9:00 10:00
12:00 Noni 10:00 12:00 Noon
2:00 PM 11 :00 2:00 PM
5:00 12:00 Noon 5:00
7:00 1 :00 PM 7:00
9:00 2:00 9:00
3:00
4:00
5:00
6:00
7:00
8:00
9:00
10:00
8:00 AM
9:00
12:00 Noon
2:00 PM
5:00
7:00
9:00
-------
Table 21. OSHA NOISE LEVEL STANDARDS
FOR INDUSTRIAL APPLICATIONS.
Noise Level (dba)' Time Duration (hr)
90 8
92 6
95 4
97 3
100 2
102 1.5
105 1
110 ; 0.5
115 0.25
Impact noise levels must not exceed 140 db.
70
-------
Table 22. AMBIENT AND PTC SYSTEM NOISE LEVELS FOR
DISCHARGE VALVE AND ADJACENT PUBLIC ROOMS
Location
Discharge
Valve Rooms
Ambient
First
Floor Charging
System Ambient System
Remarks
Shelley A South 83 db
94 db
84 db
Shelley A
73 to 80 84 to 92 78 to 80
Shelley B East 75
Shelley B West 78
Descon Concordia 65
Descon Decks
Camci
Commercial
90
83
85
67 to 95
80 to 90
52
90
85
Noise level
the ambient
ing station.
lasted for 1
Noise level
the ambient
ing station.
was at 92
-------
Table 23. AMBIENT AND PTC SYSTEM NOISE LEVELS
FOR MAJOR SYSTEM COMPONENTS
Location
Ambient
System Remarks
PTC Equipment Room
82 to 85 db
no
Compactor Room
Pull-on Container
Truck
74 to 84
90 db Ambient noise level increased to 90 db within
six inches of vent fan. System noise level
increased to 102 db within twelve inches of
the main exhausters and to 99 db within twelve
inches of the collection hopper. These noise level
were for 6 minutes per hour.
80 to System noise level within twelve inches of
85 hydraulic pump and motor increased to 93 db,
and lasted for 2 minutes per hour.
Noise level within ten feet of pull-on con-
tainer truck was 95 db, and averaged between
ten to fifteen minutes for each load.
-------
The test showed that the noise level from the
system components was, in some cases, lower than
ambient noise levels. Furthermore, the noise levels
attributed to the PTC system activities did not exceed
OSHA standards, and, in general, were much lower than
these standards.
Life Cycle Estimates
The entire PTC system was tested extensively to
provide reliable data for preliminary life cycle esti
mates. The tests, conducted on August 7, 8, and 9,
1974; January 21 to 27, 1976; and January 30, 1976,
included initial and post characterization tests in
addition to static pressure and velocity profile tests.
The major components for the PTC system were char-
acterized before and after the 18 month monitoring
program. The results from these tests showed the
amount of wear experienced for several system components
and served as a basis to predict the service life of
each component. The following components were evaluated
Main transport line,
Discharge valves,
Col 1ection hopper,
Dust collector,
Compactor, and
Chute charging stations.
Main Transport Line --
Weekly static pressure and velocity profile tests
were performed to observe any degradation along the
main transport line. The original interior surfaces of
the line were very rough, as can be seen in Figure 26.
The refuse should erode these inner surfaces as it is
carried through the system. As the wall erosion in-
creases, the pressure should gradually decrease. This
trend, however, was not observed during the monitoring
program and the results for the weekly profile tests
for degradation in air pressure and velocity are incon-
clusive.
Two sections of the main transport line were char-
acterized to determine the overall wear of the entire
line. A straight section and a curved section were
selected as representative samples. Each section was
located in the CEB as shown in Figure 27. The wear
73
-------
FIGURE 26. Original interior surfaces of the test section
of the main transport line.
-------
analysis included consideration in the following areas
t Test sample weights,
t Interior surfaces, and
• Wall thicknesses.
The weight data indicated that wear was experi-
enced along the main transport line. However, the
amount of wear is uncertain. The original test sec-
tions were heavily corroded. Formations of rust and
scale were observed in the samples, as attested to by
Figure 28. These formations would easily erode and
prejudice the weight data. A better procedure was
considered to weigh the replacement sections, initi-
ally, and the test sections after the program. This
procedure should provide for more reliable information
The weight data are presented in Table 24.
Table 24. WEIGHT DATA OF THE TEST SECTIONS
OF THE MAIN TRANSPORT LINE
Straight Section Curved Section
Replacement 658.5 Ib 867.0 Ib
Sample1 633.5 863.0
Difference 25.0 4.0
1
Weight of sample section after 18 months of service.
The surfaces of the test samples after 18 months
were smoother than the original surfaces. A wear path
appeared along the test samples as observed in Figure
29. The interior surfaces were smoother than the
original surfaces, as seen in Figure 30.
Surface impressions were made before and after the
monitoring program at specified locations in order to
observe any wear. These samples were cut so that the
surfaces could be viewed by a metallograph and photo-
graphed. Two such areas are shown in Figures 31 and
32. In each case, the original surface was rougher
than the final surface. Hence, the main transport line
did experience wall erosion.
The wall thicknesses of the test sections were
measured during the initial and final characterization
periods by a Branson Caliper, an ultrasonic device.
75
-------
Curved Section
.
*
Straight
Section
FIGURE 27. A section of the transport line in
the CEB showing the two test sections.
FIGURE 28. A sample of the formations of rust
and scale which were removed from the interior
test sections of the main transport line during
the initial characterization period.
76
-------
FIGURE 29. Wear path along the straight
section of the main transport line before washing,
FIGURE 30. Wear path along the straight
section of the main transport line after washing.
77
-------
FIGURE 31. Metallographic view of a cross section
of the bottom interior surface for the straight test
section. The lower view is the original surface
while the upper view is the same area after 18 months
of operation. The magnification is at 13.3x.
FIGURE 32. Metallographic view of a cross section
of one side of the interior surface for the curved
test section. The lower view is the original surface,
while the upper view is the same area after 18 months
of operation. The magnification is at 13.3x.
78
-------
The differential thickness readings were used to sup-
port preliminary life cycle estimates for the entire
main transport line. An array of readings taken at
six-inch intervals and at fifteen degree rotations was
established to provide data. Figure 33 shows the
locations for these readings. The results of these
measurements appear in Tables 25 and 26 for the straight
and curved test sections, respectively.
Discharge Valves --
The discharge valves were analyzed for wear by plate
thickness, surface impression, and observation. In par-
ticular, the Teflon bearing surfaces and discharge valve
plates were investigated.
The Teflon bearing surface, which is one sixteenth
of an inch thick, allows the discharge valve plate to
slide horizontally. The overall condition of these
bearing surfaces after 18 months of operation was very
poor. Some sections were heavily scratched and chipped,
while other sections were either loose or missing.
These conditions are depicted in Figures 34 and 35.
FIGURE 34. Metallograph view of the surface
condition of the Teflon seal at the Shelly A
discharge valve. The upper view shows the
original condition and the lower view shows
the condition after 18 months of service.
Magnification is at 13.3x.
79
-------
CX>
o
FIGURE 33. Location of wall
on the straight and
thickness reading measurements
curved test sections.
-------
Table 25. WEAR MEASUREMENT RESULTS FOR THE
STRAIGHT TEST SECTION OF THE MAIN TRANSPORT LINE
Angle
0°
90°
360l
D
0
W '
N "
S •
T -
R .
A '
M
4
4
4
4
4
4
4
315V
•I-27C
T C. 1 L
225^
0°
Xs",
\ A B
C D
E F G H I J \
7 y
^|^/135° ^/
180°
Column
A
0
0
42
0
42
8
53
42
2
47
2
14
51
4
3
9
5
2
5
3
8
14
0
0
0
B
2
5
0
0
0
0
0
0
45
7
5
3
61
9
10
1
0
1
3
1
9
0
0
0
2
C
*
0
5
0
0
3
13
0
0
4
2
7
13
6
0
2
0
6
6
0
14
10
0
4
*
D
5
7
0
1
40
0
0
44
0
0
6
10
41
8
1
0
2
1
1
10
17
16
7
6
5
E
3
7
0
0
0
0
9
5
7
1
9
9
17
7
0
0
2
10
10
7
18
9
0
9
3
F
3
0
0
0
0
2
0
0
4
1
13
1
9
7
3
3
7
5
9
5
18
5
0
0
3
G
3
3
5
0
2
0
5
6
0
16
19
13
15
9
6
0
1
5
8
0
7
18
2
0
3
H
6
6
1
1
0
0
39
11
0
6
10
51
16
8
1
8
0
11
11
10
11
3
9
3
6
I
*
45
5
46
0
0
4
13
4
4
8
8
13
10
1
0
2
1
1
5
16
7
0
0
*
J
0
40
0
0
0
0
3
51
0
47
6
1
0
10
10
2
1
8
8
10
12
10
0
6
10
NOTE: All readings are in thousandths of an inch.
*'l"he hanger of the section was at these positions so
that, there uatv no readings made.
81
-------
Table 26. WEAR MEASUREMENT RESULTS FOR THE CURVED
TEST SECTION OF THE MAIN TRANSPORT LINE
Angle
0°
15°
30°
45°
60°
75°
90°
105°
120°
135°
150°
165°
180°
195°
210°
225°
240°
255°
270°
285°
300°
315°
330°
345°
A
6
6
3
6
0
1
0
0
0
5
12
5
8
5
4
7
9
22
17
19
4
9
0
1
B
5
5
0
0
3
0
0
0
8
6
13
4
7
2
10
1
20
33
27
19
1
6
0
2
C
10
1
4
41
0
4
0
0
0
5
12
1
2
6
12
9
26
31
19
8
3
5
0
0
V
D
10
45
41
45
40
0
0
0
2
8
11
3
10
13
17
13
29
32
18
10
0
7
0
43
E
3
47
37
2
40
0
1
1
2
0
2
6
1
12
11
15
27
27
59
13
49
3
38
0
F
1
40
43
42
40
0
0
0
4
0
10
5
0
9
25
11
25
21
28
11
10
10
0
10
G
0
52
0
4
42
43
26
0
2
S
11
1
0
17
20
10
16
23
50
13
9
8
0
5
Column
H
4
40
0
0
39
0
4
50
39
0
5
2
7
20
9
10
13
17
16
7
3
4
35
0
I
4
43
0
5
36
0
0
54
0
4
0
2
7
9
5
20
11
6
11
4
6
6
3
7
J
3
1
0
0
0
•o
0
44
5
1
5
5
0
7
2
7
47
7
9
0
3
3
0
0
K
2
4
1
2
39
0
7
38
3
5
6
4
0
3
2
0
2
7
12
10
0
11
0
0
L
0
50
32
0
36
5
0
38
4
12
4
3
0
6
1
0
1
18
13
10
2
4
0
1
M
1
0
0
1
0
0
1
0
0
3
1
2
0
6
0
3
0
18
9
2
1
43
0
0
N
2
0
1
0
0
9
0
0
3
• 4
8
15
0
1
0
1
0
2
0
9
9
10
0
0
.
NOTE: All readings are in thousandths of an inch.
82
-------
CD
CO
FIGURE 35. Discharge valve at Shelly B East
seal. Its condition is very poor with deep
and missing sections.
showing the Teflon
chips, scratches,
-------
The discharge valve plates also showed signs of
wear. The top surfaces were heavily dented and
scratched as shown in Figures 36 and 37. To find the
extent of this wear, surface impressions were made of
the valve plates (see Figures 38 and 39). A typical
dent of the following dimensions, 0.146 inch long and
0.014 inch deep, is illustrated in Figure 40.
The Branson Caliper was used to measure the
thickness of the plates. Figures 41 and 42 identify
the locations for measurements. The wear of the dis-
charge valve plates is presented in Figures 43 and 44.
These two figures show that the center of each plate
experienced the greatest amount of wear.
Col 1ection Hopper --
The collection hopper was investigated for wear.
There were stagnant areas near the corners of the col-
lection hopper where refuse stuck to the wall. The
refuse accumulated in paste-like layers. Figures 45
and 46 show that these formations were noticeable after
one month of operation. By the end of the monitoring
program, as illustrated in Figures 47 and 48, these
layers were about 1-1/2 to 2 inches thick. However,
the majority of the interior surface was very smooth,
similar to sand blasted surfaces, as shown in Figure 49
There was one section directly downstream from the
entry line which was dented, and had a one-eighth inch
thick crumbly layer of refuse. This is seen in Figure
50. The Branson Caliper was used to measure the wall
thickness in this area. The results are reported in
Figure 51.
Dust Col 1ector - -
The dust collector employed by the PTC system was
of the bag house variety. Airborne particulate matter
and viable particles were removed from the system air
by passing the air through felt filters. The dust and
viable particles would be collected on these filter
bags and the purified air was returned to the environ-
ment. An air shaker apparatus sent bursts of air into
these bags to dislodge the accumulated particulate
matter. The dust particles fell to a rotary valve
which discharged the particles into a drain.
After two months of operation, it was noticed that
the rotary valve at the base of the dust collector did
not operate properly- Instead of discharging the dust
-------
FIGURE 36. Section of the discharge valve plate
at Shelley A. The surface is heavily dented.
FIGURE 37. Section of the discharge valve plate
at Descon Concordia, showing dented areas.
85
-------
CO
CTl
FIGURE 38. Surface impressions of discharge valve plates
-------
00
FIGURE 39 Surface impressions of the discharge valve plates
at Descon Concordia (left) and Shelley A (right).
-------
FIGURE 40. Metallographic view of a discharge valve
plate replica showing a typical dent. The upper
replica shows a portion of an unused plate. The
lower replica shows a section of a used plate with a
dent of dimensions 0.146 inch long by 0.014-inches
deep. Magnification is at 13.3x.
88
-------
FIGURE 41. Locations on the discharge valve plates used to measure
plate thickness. The left view is at Camci, and the right view
is at Descon Concordia.
-------
DISCHARGE
VALVE
AXIS OF TRAVEL-
AXIS PERPENDICULAR
TO TRAVEL
DISCHARGE VALVE
PLATE
FIGURE 42. Top view of typical discharge valve showing the
locations of the axes used in determining the thickness
of the discharge valve plates.
90
-------
.640
(S)
.630-j
.620
PT. B
.640-
.630-i
SHELLEY A
PT. B
DESCON CONCORDIA
10 20
DISTANCE ACROSS VALVE
PLATE IN INCHES
FIGURE 43. Profiles of thicknesses of
certain discharge valve plates along
the axis perpendicular to travel.
91
-------
I/O
LU
co
CO
UJ
.640-1
.630-1
DESCON CONDORDIA
10 20 30 36 4O
DISTANCE ACROSS VALVE PLATE IN INCHES
PT. A
FI
di
GURE 44. Profiles of thicknesses of certain
scharge valve plates along the axis of travel.
92
-------
FIGURE 45. Layers of trash and other refuse that have accumulated
at the upper corners of the collection hopper after one month of
operation. Left side shows the northwest corner and the right
side shows the northeast corner of the hopper.
-------
FIGURE 46. Layers of trash
have stuck to the inside of
hopper door after one month
and refuse that
the collection
of operation.
94
-------
L
,
- /
FIGURE 47. Upper southeast corner of the
collection hopper showing refuse buildup
which is about 1-1/2 inches thick.
FIGURE 48. Upper northeast corner of the
collection hopper. The layer of refuse is
about 2 inches thick.
95
-------
FIGURE 49. Typical wall
hopper. The surface is
blasted and signs of
section of collection
shiny as though sand
wear are evident.
FIGURE 50. Portion of collection hopper wall about
three feet downstream from inlet section. Some
denting is apparent and a crumbly layer of refuse,
up to 1/8 inch thick, is built-up on the surface.
96
-------
TOP
E F
ROW
1
2
3
4
5
6
7
COLUMN
A
0
0
0
0
0
4
3
0
3
B
0
0
1
1
1
9
9
6
4
C
0
0
0
2
7
10
9
11
4
0
0
0
0
2
4
10
9
13
6
E
0
0
4
4
8
11
9
13
10
r
0
0
9
6
9
8
14
9
9
NOTE: All readings show wear in thousandths of an
inch. The columns are spaced in six inch
intervals and the rows are spaced in four
inch intervals.
SIDE
FIGURE 51. Wall thickness wear measurements for a
test section of the collection hopper.
-------
into a drain, the valve merely collected it and clogged
To alleviate this problem, the rotary valve was removed
and a plywood board was placed over the opening at the
dust collector base, as seen in Figure 52. The air
shaker apparatus was turned off, and the dust particles
gathered on the felt filters. Figure 53 shows the
filter bags at the end of the monitoring program. Dust
particles have coated the bags in layers 1 to 1-1/2
inches deep. The layers are loosely held and any air
movement will disturb the dust.
The rotary value was removed and the air shaker
turned off in the fall of 1974. Thus, for more than
one year of system operation, the dust collector did
not operate as designed but the efficiency of the
filter was not impaired as shown in the particulate
test.
Compactor Equipment --
The compactor unit used in the Jersey City Opera-
tion Breakthrough site consisted of a hydraulic refuse
compactor assembly and a container handling system.
Problems were found to exist in both. The problems
associated with the compactor assembly are considered
first.
Hydraulic Refuse Compactor Assembly-- Separating
the refuse collection hopper from the compactor was a
horizontal plate called a hopper gate. This gate
operated pneumatically, allowing trash to fall from the
collection hopper into the compactor. Here, the trash
was compressed by a hydraulic ram into a refuse con-
tainer.
The hopper gate was set up to operate within a
specified time interval. If this time interval was
exceeded, the system would malfunction. In the final
month of the monitoring program, the gate experienced
problems in opening and closing within the designated
time which created frequent system malfunctions. •
.In order to prevent refuse from scattering out of
the compactor unit, neoprene wipers were installed on
the hopper gate and on the compactor ram. These wipers
were to be adjusted and replaced periodically. During
the monitoring program, it was noticed that these
periodic checks of the wipers were not performed. As
such, the wipers became extremely worn and thus allowed
refuse to litter the compacter equipment. An example
of the excessive wear on the wipers is illustrated in
Figure 54.
98
-------
FIGURE 52. Views of the dust collector base
and the rotary valve assembly. The rotary valve
assembly was removed in the fall 1974.
-------
FIGURE 53. Filter bags inside the dust collector
after 15 months of operation with air shaker
equipment and filter globe valve not working.
Figure 54. Section of neoprene wiper of the
compactor after 18 months of operation.
Scratches are about 1/32-inch deep.
100
-------
The compactor, which compacted refuse into a con-
tainer, showed signs of wear on all surfaces. Upon
close examination, it was found that the wear was com-
posed of fine scratches parallel to the movement of
the ram. These scratches are illustrated in Figures 55
and 56.
The top plate of the ram was chosen as a repre-
sentative sample to determine the extent of the wear
for the compactor. A Branson Caliper was used for this
task. The test points chosen for measurement are shown
in Figure 57. The amount of the wear is depicted in
Figure 58.
FIGURE 55. Surfaces of compactor and ram
showing series of fine parallel scratches.
Another problem with the compactor equipment was
found to be the hydraulic fluid. The type of hydraulic
fluid used in the compactor ram operated best at a tem-
perature around 70°F. The room that housed the com-
pactor equipment, as stated in the design specifica-
tions, was to be maintained at this temperature level.
However, because the room was not heated and an exte-
rior door was constantly left open, the required
temperature was not met. For these reasons, the
hydraulic fluid became sluggish and prevented the
compactor ram from operating properly, causing system
malfunctions. This was particularly a problem during
the wi n ter months.
101
-------
FIGURE 56. Metallographic view of compactor surface replicas
magnified at 13.3x. The upper section is the compactor
face and the lower section is the compactor ram top.
FIGURE 57. Location of points used to measure
thickness of compactor top. The row of caliper
couplant fluid is to left of center.
102
-------
0.260-1
-------
Container Handling System — The container handling
system was composed of a motor control center which
operated the system; power and free motion rollers to
slide the refuse containers into position at the com-
pactor; hydraulic lift carriages on chain driven
trolleys which laterally switched containers to and
from the compactor; and various limit switches that
showed completed operations. The system was designed
to be operated by one man from the motor control
center. Basically the system was operated in the
following fashion. A full refuse container is moved
from the compactor to a pickup area and replaced with
an empty container.
Problems were found to exist in the following con-
tainer handling system components:
Motor control center,
Free motion rol1ers,
Chain driven power assisted rollers,
Hydrauli c lifts,
Chain driven drive for the lift carriages,
Hydrauli c line, and
Limit swi tches .
Motor Control Center—In the motor control center,
(see Figure 59), a problem was encountered with moving
FIGURE 59. The compactor motor control center
104
-------
one of two hydraulic lift carriages. (These carriages
were used'to move the containers laterally from the
compactor.) The problem was that a circuit breaker
would not remain closed. Thus, the power needed to
operate the carriage was not available. To complete
the circui.t, site personnel closed the contacts of the
circuit breaker with a screwdriver.
Free Motion Ro11ers--Free motion rollers were used
to move refuse containers to and from the compactors.
The set of rollers closest to the loading dock had
problems with the supports for the rollers and the
steel frame housing them. Observation showed that the
supports for the rollers, called pillar blocks, were
crushed, and the entire supporting frame was twisted
(see Figures 60 and 61).
Chain Driven Power Assisted Rollers-- Another
roller related problem was with the chain driven power
assisted rollers. These rollers, which were used in
conjunction with the free motion rollers to move
refuse containers, were driven by a motor and chain
mechanism. The bolts for the sprockets on the rollers
would shear. When this occurred, the rollers would not
operate, and thus the refuse containers could not be
moved.
Hydraulic Lift — The hydraulic lifts were improp-
erly designed in that they were unable to lift a fully
loaded refuse container so that it could be moved to
the pickup area. Therefore, since the pickup area
could not be used, the containers had to be dragged
directly from the compactor. This was ;complished by
the pull-on container truck when it arrived to pick up
the containers for disposal.
Chain Driven Drive for the Lift Carriages — The
chain drive, which was built into trenches in the
floor, provided the means for lateral movement of the
refuse containers. The problem experienced was that
trash and litter in the area fell into these trenches
and eventually fouled the chains and caused system
malfunctions.
Hydraulic Line — There was a problem with the
hydraulic line that operated the lift carriages. To
protect this line from the chain drive mechanisms, a
take-up reel was installed. On one occasion, the
hydraulic line became tangled in the take-up reel and
was si ashed.
105
-------
FIGURE 60. One of the shattered pillow
blocks used to move containers.
FIGURE 61. View of free motion
rollers out of alignment.
106
-------
Limit Switches--Various limit switches of the con-
tainer handling system did not operate. During the
monitoring period, it was noticed that two limit
switches used to show when an empty container was in
position at the compactor did not function. At the end
of the monitoring period it was observed that these
switches had not been repaired.
A problem developed with another limit switch when
the original metal doors to the refuse containers were
replaced by canvas flaps. When a refuse container was
connected to the compactor, the opened metal door would
activate a limit switch. This permitted the PTC system
to compact refuse automatically. However, the con-
tainer doors, when replaced by canvas flaps, did not
mate with the switches. To override this problem, site
personnel permanently fixed the switch so that it
always indicated that a container was connected to the
compactor. On occasions, refuse was shoved over the
floor by the compactor when the container was not in
position.
Chute Charging Stations
The fifty-six chute charging stations at the site
rtere investigated to identify types of problems. The
results of the investigations are presented in Table
27.
Table 27. DISTRIBUTION OF CHARGING STATION
PROBLEMS AFTER 18 MONTHS OF SERVICE
Problem Quanti ty Percent
Rubber safety flap was not installed 36 64
Missing rubber safety flap1 7 35
Torn rubber safety flap1 4 20
Missing locking mechanism hardware 8 14
Defective chute door return unit 6 11
Chute door failed to close completely 6 11
Chute door scrapes on frame 2 4
Chute door opens into closet door 2 4
Missing chute door handle 2 4
These figures are based on 20 chutes, sinae the
other 36 chutes were installed without any flaps.
107
-------
ECONOMIC DATA
To determine the actual costs incurred by the PTC
system, the period from January 1 to December 31, 1975
was considered. Although the monitoring program ran
for 18 months, the first six months of system moni-
toring, from July to December 1974, were not included
because of prolonged downtime periods caused by a
multitude of site problems. The areas examined to
ascertain the costs of the PTC system included:
Capital costs,
Engineering costs,
Site labor costs,
Contract labor costs
Energy costs, and
Material costs.
were
The sources used to gather these economic data
Site and power plant managements,
Private service contractors,
Local power utility,
Equipment manufacturers,
Department of Housing and Urban Development,
and
Others.
In additio.n, a record was kept of site labor expenses
that were not reported from these sources during the
monitoring program.
The actual costs of the PTC system at the Jersey
City Operation Breakthrough site are reported in Table
28. A breakdown of the annual labor costs of the
system are given in Table 29. The energy usage for the
PTC system is about 79,815 kWh per year and is deter-
mined in Appendix M. Simply stated, during the moni-
toring period of January 1 to December 31, 1975, the
PTC system collected 248.3 tons of refuse at a co?t of
$120,021.
It should be noted that all economic data have been
converted into terms of October 1975 dollars. This was
done because the previous study on the refuse collec-
tion systems at the other Operation Breakthrough sites
reported costs in these terms (Ref. 2). The common
economic base of October 1975 dollars allows the
Operation Breakthrough solid waste management systems
to be directly compared.
108
-------
Table 29. ANNUAL LABOR COSTS TO OPERATE THE PTC SYSTEM
Engineering
Plant Engineer
O
VO
Contract Labor''
Actual Adjusted
530.00 562.47
325.00 335.48
400.00 410.56
1,255.00
The skilled labor index converts the actual costs to the adjusted October 1975 costs.
Month Actual
January
February
March
April
May
June
July
August 202.32
September 369.40
October
November
December
Total 571.72
Adjusted Actual
976.50
361.26
84.15
460.99
252.47
308.57
1,563.88
204.02 743.37
372.31 210.40
63.12
539.99
743.38
576.33 6,308.08
Adjusted
1,092.67
337.23
89.77
490.02
266.99
318.52
1,605.15
749.63
212.06
63.12
538.81
740.42
6,504.39
Site
Actual
764.25
764.25
764.25
1,113.24
764.25
917.99
764.25
1,181.23
764.25
1,106.25
764.25
764.25
10,431.95
Labor4
Adjusted
828.06
825.62
825.62
1,198.18
811.56
935.06
774.64
1,185.84
766.39
1,106.25
763.25
762.26
10,782.73
Labor
Skilled1
1.0712
1.0668
1.0668
1.0630
1.0575
1.0322
1.0264
1.0084
1.0079
1.0000
0.9978
0.9960
Indices
Common
1 . 0835
1.0803
1.0803
1.0763
1.0619
1.0186
1.0136
1.0039
1.0028
1.0000
0.9991
0.9974
2
The common labor index converts the actual costs to the adjusted October 1975 costs.
Contract labor aas used to assist site personnel in removing main transport line blockages.
A
The cost data include observed estimated costs.
-------
TABLE 28. ACTUAL COSTS OF SOLID WASTE MANAGEMENT SYSTEM
AT THE JERSEY CITY OPERATION BREAKTHROUGH SITE
Item
CAPITAL COSTS
Engineering
Discharge Valves
Main Transport Line
Cathodic Protection
Building Chutes and
Stations
Compactor
Compactor Containers
and Handling System
Space in CEB4
Replacement Parts
for PTC Equipment
Main Exhausters
Dust Collector
Safety Equipment
Vent Fan
Collection Hopper
Pneumatic Control Lines
Motor Control Center
Remote Control Panels
Wiring
Electrical System
Checkout
Cost1
Index
1.25
1.25
1.21
1.24
1.25
1.00
1.00
1.23
1.00
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
Original
Installed
Costs
(Dollars)
$130,116
17,516
382,956
23,696
18,939
10,000
14,000
158,205
1,710
30,283
14,921
16,026
1,105
16,758
8,842
40,89.'!
14,368
14,368
3,316
Oct. 1975
Adjusted
Costs
(Dollars)
$162,537
21 ,880
462,862
29,473
23,658
10,000
14,000
194,592
1,710
37,829
18,639
20., 01 9
1,380
20,934
11,045
51 ,082
17,948
17,948
4,142
Carrying'
Charge
0.079
0.079
0.079
0.079
0.079
0.079
0.079
0.079
0.500
0.079
0.079
0.079
0.079
0.079
0.079
0.079
0.079
0.079
0.079
$1,121,750
Annual
Cost
(Dollars/Year)
$12,906
1,737
36,751
2,340
1,878
794
1,112
15,451
855
3,004
1,480
1,590
110
1,662
877
4,056
1,425
1 ,425
329
$89,782
Percent
10.8
1.4
30.6
1.9
1.6
0.7
0.9
12.9
0.7
2.5
1.2
1.3
0.1
1.4
0.7
3.4
1.2
1.2
0.3
74.8
-------
OPERATING AND MAINTENANCE COSTS
Engineering Time $ 576 °'5
Plant Engineer5 6>504 5-4
Contract Labor6 1.309 1.1
Plastic Bags 793 °-7
Site Labor7 8,593 7.1
Labor Supervision8 2-190 K8
Electricity9 2-474 2.1
Hauling and Landfill Fees 7.800 _6.5.
$ 30,239 25.2
TOTAL ANNUAL COSTS $120,021 100.0
The cost index is a factor to convert the original instated costs to October 1975 adjusted costs.
2 . .
The carrying charge consists of a 7.5 percent interest rate plus a sinking fund factor for
depreciable capital costs.
The annual cost for capital equipment is the product of the adjusted costs multiplied by the
carrying charge.
4
The space allotted for the PTC equipment in the CEB is about ZG percent of the total space.
Plant engineer with 257 hours regular time and IJ4 flours overtime.
Contract labor is used to remove main transport line blockages.
2387 man-hours at $3. 00 per hour with 20 percent fringes
Q
358 man-hours at $5.00 per hour with 20 percent fringes
9
79,815 kWh at 3.1 cents per kWh is supplied by the total energy plant. The local electric
utility would charge $3,360 for the same usaga.
-------
The actual costs of the system wtth regards to
the capital costs (Table 28) were determined by con-
verting the original cost dollars to annual cost dollars
This was accomplished by: (1) generating cost index
factors in order to convert the original construction
costs to October 1975 dollars, and (2) developing car-
rying charges to adjust the October 1975 dollars to the
annual costs.
The cost index factor is a ratio of the construc-
tion costs indices for October 1975 to the original con-
struction date indices, as obtained in References 3 to
25. Using this cost index factor, the original construc-
tion costs could be converted in October 1975 dollars.
Then, these dollars are multiplied by a carrying charge
to determine the annual costs of the system.
The carrying charge is the sum of the interest
rate and a sinking fund factor for depreciable capital
cost, and it is:
where: i is the interest rate
n is the depreciation period in years
In all cases the depreciation period is considered to
be the expected 40-year life of the equipment, and the
annual interest rate is established at 7.5 percent.
112
-------
SECTION V
DATA EVALUATION AND ANALYSIS
The technical and economic data collected during
this study of the PTC system (installed and operated at
the Jersey City Operation Breakthrough site) were evalu
ated and analyzed. System performance is investigated
with respect to the achievement of design specifica-
tions and the assessment of the economy, effectiveness,
and feasibility of a PTC system to collect residential
refuse. To fulfill these objectives, the following
subjects were examined:
• Technical,
• Economic,
• Residential acceptance, and
t Envi ronmental.
TECHNICAL EVALUATION
The data collected during the monitoring program
were evaluated to determine the overall system per-
formance and service life for the pneumatic trash col-
lection system. These evaluations were compared to
design estimates to observe whether the actual system
favorably complied with the design requirements, and to
identify those areas where the PTC system did not
perform satisfactorily. The specific technical topics
considered in these evaluations were as follows:
t Reliability and availability,
• Maintainabi1i ty ,
• Performance, and
t Servi ce 1i fe.
113
-------
Reliability and Availability
The system reliability as observed during the
monitoring program was compared to the design condi-
tions. System reliability was defined as the prob-
ability that a system would continue to perform for a
specified time interval of successful operations. In
order to investigate the system reliability, the
following topics were considered:
• The overall system availability;
• The probability that the PTC system would
continue to collect refuse automatically
for a specified number of successful
cycles; and
• The evaluation of observed reliability
characteristics to recommend design consider-
ations for future applications of PTC
systems.
The system reliability as stated in the design
specifications declared particular conditions. These
conditions are:
• An adequate number of redundant equipment and
controls so that a malfunctioned component,
or scheduled maintenance for individual
components, would not suspend PTC operations;
t All components, parts, and controls must
be designed for high reliability;
• A preventive maintenance program;
• Frequency of system malfunctions should
not exceed one malfunction per month;
• Repairs should be initiated within 24 hours
after a system malfunction; •
• Safety controls to prevent component
damage, plant failures, personnel in-
juries, and service interruptions; and
• Signals (visible and audible) at the
central control panel to locate malfunc-
tioned components.
114
-------
Overall System Availability --
The overall system availability was compared to
the designed availability. However, before discussing
whether the PTC system attained the required level of
reliability, several terms must be defined.
Survival Curve — A graph which shows the prob-
ability that a system will remain functional for a
specified time interval of successful operations. The
mean time between failures (MTBF) as defined by the
graph shows the mean time interval that the system will
remain in operation before failure.
Repair Curve--A graph which illustrates the prob-
ability that a system will be repaired to an operable
mode within a specified time interval after a system
malfunction. The mean downtime (MDT) describes the
time interval within which system has a 50 percent
probability of being repaired.
Active Repair Curve — A graph similar to the repair
curve except that the time frame includes only the
elapsed calendar time required for repairs. The mean
active repair time (MART) is the time interval within
which system has a 50 percent probability of being
repaired once active repair measures are initiated.
Operational Availability (A0)--A parameter for a
system which describes the probability that the system
is in an operable mode as measured against active time.
The design availability for the PTC was not specifically
stated in the design specifications except that there
should be no more than one system malfunction per month
and that repairs should be initiated within 24 hours
after a malfunction.
The reliability data were presented against
various time scales, which were calendar time, active
time, and scheduled cycles. The calendar time is dis-
aggregated into the following dimensions:
CALENDAR
TIME
INACTIVE
ACTIVE_ . M,
TIME TIME
DOWN-.
DEMAND
TIME TIME
OPERATING
NON-OPERATING
TIME TIME
115
-------
Active Time — The scheduled operating period for
each day; for example, automatic operation scheduled to
operate every hour between 7:00 A.M. and 10:00 P.M. (16
cycles per day or 15 hours per day).
Demand Time — The operating and non-operating time
achieved without downtime in the daily schedule.
Downtime-- The time accrued by failures in the
active time schedule.
Operating Time — The time required to complete one
cycle of operation.
Non-operating Time — Time between cycles during a
scheduled scenario for each day in which the PTC system
is ready for operation.
The survival curves for the PTC system are pre-
sented in Figures 62 and 63 for calendar and cycle time
respectively. The MTBF for calendar time was about 16
hours and the MCBF was 15 cycles.
Mainta inabi1i ty
The observed system maintainability was compared
to design expectations. System maintainability was
defined as the probability that a failed system could
be restored to an operable mode within a specified time
i nterval.
Therefore, the maintainability analysis considered
the following topics:
• The repair time required to correct indi-
vidual component malfunctions.;
t The effects of system malfunctions on the
col 1ection servi ce;
t The effects and probability of a major*system
breakdown; and
t The maintainability of the system and recom-
mendations for future PTC system applications,
116
-------
110 MO t»0
Active Time (hours)
200 2ie i*o no
FIGURE 62. PTC system reliability curve
Probability of survival vs. active time.
-------
CO
.4.
WO 120
Cycle Time
Number of Scheduled Cycles
FIGURE 63. PTC system reliability curve:
Probability of survival vs. scheduled cycles
-------
The major components of the system were analyzed
with regard to:
t Number of failures,
• Total and mean downtime,
« Total and mean repair time, and
• Total and mean repair time in man-hours.
The maintainability analysis also identified those
components which were more critical for successful
system operations. This was made by establishing a
criticality ranking.
The design specifications listed certain mainte-
nance requirements to reduce repair time and enhance
maintainability. These specifications called for the
major components to be designed such that all removable
parts could be replaced or repaired at the site, and
that these repairs would restore the components to the
conditions of new equipment wherever practical. Further,
mechanical and electrical components should be designed
to operate at least 15,000 calendar hours (1.7 years)
between major overhaul periods.
The maintainability characteristics for the PTC
system are determined by downtime and repair curves.
The downtime curves are presented in Figures 64 and 65
for calendar time and missed cycles. The downtime
curves in Figure 64 are recorded for calendar and
active time frames. The value for the mean downtime
(MDT) was 3.4 hours for calendar time. Thus, the mean
time to repair the system to an operable mode was about
three hours. The mean cycle downtime was three cycles.
Therefore, the mean time to repair the system to an
operable mode was three cycles. The repair curve for
active repair time is shown in Figure 66. The value
for the mean active repair time (MART) was assumed to
be one-half hour. Thus, the mean time to restore the
PTC system to an operable was about 30 minutes after
repair efforts were initiated.
A criticality ranking was developed to identify
those system components which severely affect the
operations of the PTC system. All of the system com-
ponents were ranked by their achieved availability
which is computed by:
Aa MTBFC + MDT'c
119
-------
1000
aoo
tool
500
400
100
BO
eo
60
• 0
83:
rep«
of
elap
probability of being
Ired b. ' "" "
alenda
sect
. , 1 I UJ Wl u« -I.* .
efore 24 hours J
r time *•'••- fc-^
92J probability of
repaired before ?4
of demand time have
elapsed
being
hours
OOMntime ^
During Calendar time,
Downtime Curve During
Scheduled Active Time
Pr?b*b°1Uty *°
• 0 96
FIGURE 64. PTC system downtime probability curve:
Probability that the system would be repaired vs. time
120
-------
1000T
800-
600-
500
400
300-
200-
100
80
60
50
40
30
20
10
a
6
5
4
2-
I
0.1
1.0
10
I
30
SO 60 80 9O 95 99
100
Proba bi1i ty
FIGURE 65. PTC system probability of repair curve
Probability that the system would
be repaired vs. scheduled cycles.
121
-------
100
80
60
40
30
20
1O
J L
_L
10 20 30 40 SO 60 70 80
Probabi1i ty
90
95
98
PTC system probability of acti
bability that the system would b
f\ r\ a t v* +• -i m r\ r\ m s+ i^ ^ *«rvi-i-\^i« L^-\^* L» ^-i *-i
FIGURE 66.
c urve: P ro
vs. repair time once
ve repair
be repaired
a repair has begun.
122
-------
where: MTBF,
MDT,
mean time between component c
failure
mean calendar downtime for
component c
This index was used to order the components in a criti-
cally ranking. These results, based on total calendar
time, are reported in Table 30. An analysis of criti-
cal component failures describing the prominent failure
modes and design corrective action is given in Table 31.
Those system components identified as critical were:
Main transport line,
Programmer,
Di scharge valves,
Control panel ,
Chutes, and
Compactor.
These six components were decisive for proper PTC
system operations. They contributed to 88 percent of
all system malfunctions; to 94 percent of the total
calendar downtime; and to 89 percent of the total man-
hours needed to effect repairs.
The performance for the PTC system was evaluated
to discover whether the collection service could be
improved. This analysis considered changes for the six
critical components and is based on the following assump-
tions and from Table 30:
• There would be three malfunctions per year in
the main transport line due to water infiltra-
tion and blockages.
• Malfunctions to the programmer could be re-
duced by 95 percent to six malfunctions per
year. (A majority of the programmer malfunc-
tions were related to a defective power
supply which was replaced after 14 months.)
• Many of the problems with discharge valves
and chutes were caused by tenants. By edu-
cating the tenants as to proper use, these
problems could be reduced by 20 percent to 35
discharge valve and 19 chute problems per
year.
123
-------
Table 30. COMPONENT CRITICALITY RANKING
BASED ON 18-MONTHS OF CALENDAR TIME
ro
-Fa
Component
Main transport line
Programmer
Discharge valves
Compactor
Chute1
Control panel
Block valves
Hopper screen
Vent fan
Air inlet valves
Cycle interrupt^
Main exhausters
Auxiliary bypass valves
Collection hopper valve
No. of
Failures
22
116
65
38
36
3
9
6
6
4
4
4
2
2
MTBFr
(hours)
597
113
202
346
365
4380
1460
2190
2190
3285
3285
3285
6570
6570
MDTr
(hours)
99.5
12.2
10.3
12.6
7.4
77.8
6.6
1.8
9.9
2.5
31.0
18.9
4.3
1.0
Mean
Man-hours
to Repair
(man-hours)
21.0
1.0
2.8
1.9
3.6
17.3
3.5
0.6
4.5
0.9
2.6
1.9
10.8
0.8
Component Availability
MTBFC
MTBFc & MDTc Ranking
0.86 1
0.90 2
0.95 3
0.96 4
0.98 5
0.98 6
0.99
0.99
0.99
0.99
0.99
0.99
0.99
0.99
1
Blockages periodically occurring -In vertical trash chutes.
?
'Cycle interrupts of unknown 'cause.
-------
Table 31. ANALYSIS OF CRITICAL COMPONENT FAILURES
Component
Failure Rates
(Failures/Minion Cycles)
Failure Modes
Effect of Failure on PTC System
Correctljn Action
Main Transport Line
2.252 a) Water infiltration
b) Blockage by large objects
c) Blockage by cleaning blocked chutesv
or discharge valves, or large masses
of refuse would stop air flow
No collection service by PTC system
for an average downtime of 100 hours
(4 days), and the repair effort
usually Included outside contract
labor to remove the blockage or
water.
a) Improve seals for access plates for main transport line and
better construction of vaults
b) Educate residents and site personnel
c) Exercise greater care during r.anual collection cycles
Programmer
Discharge Valve
11,876
ro
en
a) Faulty power supply
a) Jamed open with refuse
b) Frozen pneumatic lines
c) Shorted diodes
d) Broken electrical conduit
e) Faulty limit switches
f) Controls turned off
Erratic performance of system until
replacement power supply was
installed.
A ^functioned discharge valve stops
age d«ntfTO°Hfai01i!ou^$ *" '" "
a) Install new power supply
a) Implement longer cycling times for specific valves
b) Provide supplemental space heat whenever room temperatures
c) Replace diodes
d) Replace conduit and exercise greater care in housekeeping
practices
e} Establish periodic inspection of all controls
f) Establish periodic inspection of all controls
Control Panel
*) Shorted power supply
b) Control turned off
No collection service for about 78
hours (3 days).
a) Repair short
b) Establish periodic inspection of all controls
3.686 ,-j Large objects lodged in chute
a) Large masses of newspaper lodged in
chute
c) Fire in chute and sprinkler system
did not activate
Ho collection service from location,
and can create a discharge valve mal-
function, also prolonged downtimes
can create several chute blockages.
a) Educate residents and site personnel
b) Educate residents and site personnel
c) Exercise more detailed testing of system to ensure that every
component functions properly
Compactor
3,890 a) Low hydraulic oil
b) Low room temperatures which caused
hydraulic oil to become too thick
to flow easily
c) Controls turned off
d) Container filled to capacity
e) Container handling equipment broken
i) chains snapped to overhead door
so that loaded container could
not be moved
ii) chains snapped to carriages
iii) insufficient hydraulic oil for
lifts
f) Hissing container
g) Compactor kept cycling
ti) Container not connected properly
No compaction at end of cycles and
can stop all PTC collection activi-
ties. A typical malfunction would
last 13 hours.
a) Establish periodic inspection of all equipment
b) Provide supplemental space heat whenever room temperatures
approach freezing
c) Establish periodic inspection of all controls
d) Establish periodic inspection of all equipment
e) Exerci-;*1 nreater carp in ooersMna containpr handling
equipnient, repair malfunctioned or broken components, and
establish periodic inspection ot all controls
f) Establish periodic inspection of all equipment
g) Exercise more detailed testing of system to ensure mat ever
component functions properly
h) Exen.ise greater care in changing containers
-------
• Compactor problems could be reduced by 50
percent to 13 malfunctions per year if site
personnel were more attentive to compactor
operations.
t The number of malfunctions for the remaining
system components were considered to be con-
stant at two control panel malfunctions per
year and at 25 system malfunctions for the
other components per year.
The reliability and maintainabi1ity^of the PTC
system was determined from these assumptions and the
results are presented in Table 32. The MTBF becomes
85.0 hours. The MDT was found to be 13.9 hours, or the
average time to restore the system to an operable mode
is about 14 hours after the occurrence of a malfunc-
tion. The availability for the "improved" system would
be 86 percent, as determined by:
A = MTBF/(MTBF + MDT)
A - 85/(85 + 14)
A - 0.86
The availability for the observed system was pre-
viously shown by data to be 54 percent. Therefore, the
PTC system with these improvements would exhibit an
increase in availability of 32 percent.
Many additional benefits would be realized by the
improved performance of the six critical system com-
ponents. The total number of system malfunctions would
be decreased from 211 to 103 malfunctions per year
which is a reduction of about 51 percent. Furthermore,
the total downtime would be decreased from 3737 hours
per year to 1427 hours per year for a reduction of
about 62 percent. Similarly, total repair time would
be decreased by 46 percent (from 357 to 194 hours per
year) and total man-hours for repairs would be reduced
by 51 percent (from 750 to 367 man-hours per year).
These advantages would benefit in lower downtime c*osts
and in an improved refuse collection service.
Performance
The performance of the PTC system was evaluated to
determine the overall effectiveness of the system.
126
-------
Table 32. ANNUAL RELIABILITY AND MAINTAINABILITY FOR THE PTC
SYSTEM USING IMPROVED COMPONENTS
ro
Component
Main transport line
Programmer
Discharge valves
Control panel
Chutes
Compactor
All others
Total
Failures/Year
32
62
352
22
192
132
251
103
Downtime
Total2
298.5
73.2
360.5
155.6
140.6
163.8
235.0
1,427.2
in hours
Mean1
99.5
12.2
10.3
77.8
7.4
12.6
9.4
13.9
Repair time
in hours
Total2
17.7
4.8
56.0
34.0
26.6
16.9
37.5
193.5
Mean1
5.9
0.8
1.6
17.0
1.4
1.3
1.5
1.9
Repair time
in man-hours
Total2
63.0
6.0
98.0
34.6
68.4
24.7
72.5
367.2
Mean1
21.0
1.0
2.8
17.3
3.6
1.9
2.9
3.6
1
These figures were from the observed data for the PTC system.
>
'These figures were estimated for the improved system.
-------
The analysis considered the following areas:
• The ability of the system to comply with
design loadings;
• The ability to transport overweight, over-
sized, and other bulky solid waste;
• The capacity of the system for design loads,
actual loads, and operating schedules;
• The ability to safely handle dangerous
materials;
t The adaptability of the system to recycle
specific classes of solid waste;
• The adequacy of safety equipment including
provisions to prevent component and plant
failures, personnel injuries, service interrup
tions and fires; and
• The ability of the system to perform under low
ambient temperatures.
System Ability to Comply with Design Loadings --
The ability of the PTC system to collect the
design refuse loading was investigated. The design
estimate for the refuse loading was about 7200 pounds
per day or 1300 tons per year. The site generated
only 250 tons per year of refuse, which is about 19
percent of the design capacity. The system was oper-
ated about once every hour which was sufficient for the
observed site loads. For the PTC system to handle the
full design loading of 1300 tons per year, the cycle
schedule may have to be adjusted to operate at fifteen
or twenty minute intervals. Hence, the system com-
ponents could handle the design loading.
System Ability to Transport Various Sizes and Weights
of Refuse --
The ability of the PTC system to transport over-
weight, oversized, and other bulky solid waste was
studied in the load capacity test and by observing the
unusual kinds of refuse transported by the system. The
tenants had placed many unusual objects in the PTC
system which had been successfully collected. Figures
67 through 70 show some objects that were successfully
conveyed by the system. These objects include the
128
-------
FIGURE 67. Two wood pieces, curtain rods, and wire
rack successfully collected by the PTC system.
FIGURE 68. A mechanical adding machine 7.5 inches wide,
11 inches long, and 4 inches high which was successfully
transported by the PTC system.
129
-------
FIGURE 69. One large piece of cardboard, about 3
feet by 4 feet, a shopping basket, a plastic pipe
about 3.5 feet long, and a foot weight from a
weightlifting set, which were successfully col-
lected by the PTC system.
FIGURE 70.
chair which
system.
The remains of a vinyl covered rocking
were successfully collected by the PTC
130
-------
following items
Wood pieces,
Curtain rods,
Wire racks,
A mechanical adding machine,
A large piece of cardboard (3 ft by 4 ft
approximately),
A shopping basket,
Plastic pipes,
A foot weight from a weight lifting set,
Parts of a vinyl covered rocking chair.
and
However, many objects smaller that these items caused
chute and discharge valve blockages. Newspaper, card-
board boxes, and coat hangers frequently initiated
numerous malfunctions, even though, at times, these
items were easily collected. Figure 71 shows three
cardboard boxes and a curtain rod which caused one
chute blockage. Figure 72 shows a typical discharge
valve blockage, with a large cardboard box creating
thi s problem.
System Capacity for Loadings and Scheduling --
The system appeared to be able to handle design
loads without any problems. As for the actual loading,
the system operated satisfactory at 18 cycles per day.
The results from the optimum scheduling tests, used to
determine if the system could perform adequately with a
reduced number of cycles, showed that the optimum
operating schedule could be between seven to nine
cycles per day- A feasible operating schedule for seven
daily cycles could be cycling the PTC system once every
two hours from 8 AM to 2 PM and from 5 PM to 9 PM. A
possible operating schedule for nine daily cycles might
be from 7 AM to 11 PM, with the PTC system operating
once every two hours. Further tests should be conducted
to insure that these operating schedules will provide
for a reasonably high level of service. With
number of daily cycles, operating costs could
as well as prolonging component life.
a fewer
be reduced
The results obtained from the load capacity test,
which determined the maximum density of refuse which
could be safely collected by the PTC system, were com-
pared to the .design specifications. To present the
test results, a regression line for transport velocity
versus density was generated and is shown in Figure 73
The procedure to determine the regression line is re-
ported in Appendix J. The tevt showed that as the
131
-------
FIGURE 71. Three cardboard boxes and a curtain rod
which created a chute blockage at Shelley A. A ruler
is in the foreground to show the sizes of the objects.
> ,
FIGURE 72. A large, bulky cardboard box
causing a typical discharge valve blockage.
132
-------
70-
60-
Note: The equation for the regression
line is Y = 55.7 - 0.57 X where
V is the transport velocity in ft/sec, and
X is the.density in Ibs/cu ft
iBalsa Wood
co
co
50-
40.
30-
2O-
10-
Newspaper (dry)
White Pine
Wet Rags
Bundled News-
paper (wet)
Walnut"
®
Region of Difficulty
i n .Trans i t
10
20
30
40 5O 60
Density (Ibs/cu ft
70
80
I
90
I
100
FIGURE 73. Transport velocity vs. density for
refuse samples used in the load capacity test.
-------
density of a refuse sample approached 60 pounds per
cubic foot, the sample experienced difficulty in being
easily collected. However, in the presence of other
refuse, the sample was easily transported. Solid waste
with density ranging to 100 pounds per cubic foot, when
moved in this manner, could be easily collected, as
demonstrated by brick fragments and rocks that were
successfully collected.
The design specifications stated that refuse with
a density of 50 pounds per cubic foot must be colected
by the system. The load capacity test determined that
the transport velocity of refuse with this density was
about 27.2 feet per second. Experience showed that the
PTC system had little difficulty in collecting refuse
of this density. Thus, the system did favorably comply
with the design specifications in the ability to col-
lect overweight, oversized, and other bulky solid
waste.
System Ability to Handle Dangerous Materials --
There are many types of solid waste which are
prohibited from the PTC system and are classified as
dangerous materials. Signs were posted on every charg-
ing station door to inform the tenants that the fol-
lowing items may not be placed in the PTC system:
Lighted matches, cigars or cigarettes:.
Carpet sweepings;
Oi 1 soaked rags;
Empty paint cans or aerosol containers; and
Any other flammable, highly combustible,
or explosive substance.
These types of solid waste could damage the system
and injure the personnel. However, tenants did dispose
of aerosol cans, and there were no problems in the
ability of the system to safely collect these cans.
Figure 74 shows a sample of the aerosol cans which were
collected by the PTC system.
134
-------
FIGURE 74. A sample of the aerosol cans that were
safely collected by the PTC system.
System Adaptability to Recycle Specific Solid Waste --
The PTC system could be modified to recycle
specific classes of solid waste, without major design
changes and with reasonable success. The modifications
would most likely be located at the collection hopper.
When refuse entered the hopper, solid waste was circu-
lated by the air stream such that the denser materials
fell to the bottom. Thus, light refuse, such as paper
bags, newspapers, and cardboard, was above the heavier
refuse. These paper products could be easily collected
for recycling. Other equipment could be installed to
collect the metals and plastics from the refuse.
Observations indicated that glass reclaimed at the
collection hopper may not be the most effective method.
Glass objects put into the system usually become shat-
tered. Results of the composition tests indicated that
approximately one half of the refuse classified as
fines was composed of glass. Equipment could be added
to gather the glass collected by the PTC system for
recycling. However, it would be more practical as well
135
-------
as more profitable to educate tenants to segregate
glass at the chute charging stations. More glass could
be collected in this manner and it would be of a better
quality for recycling purposes.
The estimated amount of refuse that could be ex-
tracted from the PTC system for recycling is presented
in Table 33. Refuse was classified into paper, glass,
metal, and plastics. It might be possible to recycle
80 percent of the refuse; however, the economics for
recycling these materials must be carefully considered
to determine whether it is feasible.
System Ability to Recover Valuable Items --
There is a limited capability for recovering valu-
able items which have been mistakenly placed in the
system; however, the probability of retrieving an
undamaged item is small. The effort required to re-
cover an object depends on system operations. If the
object is still in the chute storage section (a com-
partment where refuse is accumulated for a chute
between cycles), it is a simple matter of removing the
section and sorting the refuse. If a collection cycle
has been completed, the task of recovering the lost
item becomes more difficult. The refuse container must
be opened and the refuse manually sorted. Since the
refuse for the entire site is compacted into the refuse
container, chances of locating any particular item are
poor,
Adequacy of Safety Equipment --
The design of the PTC system incorporated many
control and safety features to prevent component and
plant failures, service interruptions, fires, and per-
sonnel injuries. The design specifications stated
specific conditions for these features. The system
experienced several incidents which demonstrated the
effectiveness of the safety equipment to avert any
problem.
Every component in the PTC system was designed and
constructed according to recognized national and industrial
standards and applicable local codes. The collection
hopper, dust collector, main transport line and addi-
tional components under vacuum or pressure conditions
were designed and constructed according to good prac-
tices, as well as suitable ASME Boiler and Pressure
Vessel Code and ANSI standards. All wiring and elec-
trical components were designed and constructed accord-
ing to the National Electric Code, local codes, and
with the appropriate UL approved components.
136
-------
CO
—I
Table 33. ESTIMATED AMOUNT OF SOLID WASTE WHICH COULD BE
COLLECTED FOR RECYCLING FROM THE PTC SYSTEM
Refuse Type Percent Composition Annual Amount of -,
By Weight Recycled Materials
147.7 tons/yr
18.4
19.9
10. 4
196.4
The site generates 248. 7> tons of solid waste per year.
o
"The amount of glass includes an estimated portion of 50 percent of the fines.
Paper
Glass2
Metal
Plastic
Total
59.
7.
8.
4.
79.
5
4
0
2
1
-------
Fire detectors and sprinkler systems, meeting NEPA
and local codes, were installed to prevent extensive
fire damage to the PTC system. Sprinkler systems were
placed in all chute charging stations, discharge valve
rooms, the PTC equipment room, the compactor room, and
bui1 ding -trash chutes.
The PTC system was designed and constructed with
drainage and overflow features at the CEB and discharge
valve rooms to prevent service interruptions caused by
water infiltration. This would permit rapid drainage
and prevent flooding of all electrical and mechanical
equipment if there was a breakage of a water containing
system. Landscaping around the CEB was designed so
that runoff, caused by normal and abnormal rainfalls,
would be quickly carried away from the building.
The design of the PTC system included considera-
tions for safe and effective operation, and provisions
for ample room to service and repair all components.
Performance of required maintenance activities would
not place site personnel in close proximity to rotating
machinery, hot surfaces, sharp projections, low clear-
ances, and exposed electrical wiring.
Fire Detection and Sprinkler Systems--Problems
were experienced with the fire detection and sprinkler
systems. Two specific problems might have been avoided
through a more careful building inspection. One problem
was that a fire, which started in the trash chute at
Descon Concordia on December 1, 1974, failed to activate
the sprinkler system. Another problem was several
sprinkler heads in the charging stations at Shelley A
were found to be wrapped in plastic.
The high temperature alarm cable for the number 2
main exhauster ignited on January 30, 1975. Site
personnel reported that severe vibrations from the
exhauster chaffed the cable insulation and that a short
caused the fire. Figure 75 shows a high temperature
al arm cable. *
138
-------
FIGURE 75. High temperature alarm cable for a main
exhauster, similar to the one that ignited.
Water Infiltration and Drainage — The drainage and
overflow features incorporated in the PTC system could
not handle the variety of water problems experienced at
the site. The design specifications only considered
one aspect of water oriented problems. There was a
provision to protect the PTC system when a water break
in a second system at the CEB occurred. There were
numerous cases on the site, exterior to the CEB, that
the specifications did not address.
Water
through va
problems.
fill with
of the hyd
vacuum in
trate into
main trans
of water.
with the n
to remove
transport
i n f i 1
ul ts a
I n pa
wa ter
ros ta t
the ma
the 1
port 1
There
eces sa
the wa
1 i n e .
tration into the main transport line
nd access plates created a variety of
rticular, one vault would completely
after every rainstorm. The combination
i c head over the access plate and the
in transport line caused water to pene-
ine. The designs of the vaults and the
ine had no provisions for the removal
fore, in many cases, private contractors
ry skills and equipment were required
ter that had infiltrated into the main
139
-------
The floor drains for the discharge valve rooms
should be independent from any other plumbing lines.
The floor drain at Shelley B West was connected to a
roof drain. During one severe rainstorm, the drain was
blocked and stormwater flooded the discharge valve
room. The water level was over the discharge valve,
and water entered the main transport line. This created
mechanical and electrical problems with the PTC system.
The designs of future PTC systems should consider
better methods and procedures to resolve all drainage
and overflow problems. The site experienced long
downtimes and extensive labor efforts to remove water
from the main transport line. Future applications of
PTC systems should investigate more controls for drain-
age and overflow problems.
System Ability to Perform Under Low Temperatures --
It was observed that the system did not operate
properly under conditions of low temperature. The main
problems were with the compactor and the pneumatic
lines. As mentioned previously, the compactor was
housed in a room that was not heated. The hydraulic
oil used in the compactor operates in temperatures near
70°F. At lower temperatures, the oil became more
viscous and caused frequent compactor failures.
The air inlet and discharge valves were operated
by pneumatic lines. These lines were also located in
rooms that were not heated. At low temperatures,
moisture in the pneumatic lines froze and caused con-
trols to malfunction.
Service Life
The service life for the PTC system was based on
the service life of the components considered crucial
for system operations. These components were the main
transport line, the discharge valves, and the compac-
tor. Preliminary life cycle estimates for these Criti-
cal components, based on the technical data 'gathered
during the monitoring program, are compared to the
service life as stated in the design specifications.
These specifications stated that the service life shall
be forty years.
Ma in Transport Li ne --
The two test sections for the main transport line
were investigated for wear during the initial and final
characterization tests. Detailed calculations to pre-
dict the service life for the line are presented in
140
-------
Appendix K. The original wall thickness was 0.500 inch
and the annual wall erosion rate was 0.012 inch. It
was determined that a failure would occur if the wall
thickness was less than 0.070 inch. This condition
could be expected to occur after 36 years of operation,
four years less than the design life of 40 years. This
was determined by:
service life
Discharge Valves --
°-50°
" 070 inch
.
0.012 inch/year
36 years
The d
and Camci
serviced a
experience
valve. In
studied, s
The calcul
discharge
estimated
discharge
ischarge valves at Shelley A, Descon Concordia,
were investigated for wear. These stations
ll the MFHR buildings and were assumed to
the greatest amount of wear of any discharge
particular, the discharge valve plate was
ince this part showed the most signs of wear.
ations to predict the service life for the
valves are presented in Appendix L. The
service life for the plates, and thus for the
valves, ranged from 58 to 106 years.
Compactor --
The compactor ram, which appeared to experience
the greatest amount of wear for the compactor unit, was
investigated. The top plate of the ram was measured
for thickness by the Branson Caliper, an ultrasonic
device. The original plate thickness was 0.255 inch
thick, and the annual wear rate was 0.0067 inch. It
was assumed that the top plate could wear completely
through before operating problems would occur. The
service life for the compactor was found to be 38
years, two years less than the design life of 40 years.
This was determined by:
5
0.00671nch/year
38
Results of Wear Measurements --
The preliminary life cycle estimates showed that the
main transport line and the compactor may fail before
the designed service life of 40 years ends. It is con-
cluded that the compactor could be easily repaired.
However, a main transport line failure would create
141
-------
severe and costly problems for several reasons:
Locating the failed section,
Excavating in order to reach the section,
Repairing and/or replacing the failed section,
Backfilling to cover the section, and
Providing an alternative refuse collection
service dur'ing the repair efforts.
ECONOMIC EVALUATION
The economic data used for the evaluation were
obtained from the Department of Housing and Urban
Development, site management, and other sources during
12 months of the monitoring period. The costs incurred
by the PTC system were disaggregated into capital,
operational, and maintenance costs and compared to
three types of conventional solid waste management
systems commonly used in residential complexes such as
the Jersey City Operation Breakthrough site. The
annualized costs for all four refuse collection systems
are projected to the year 1995 to show the economic
relationships between the systems. Furthermore, the
observed system costs were compared to design esti-
mates.
Annua1 Cost
PTC System --
The cost to operate the PTC system during the
monitoring period of January 1 to December 31, 1975
were reported in Table 28. The system costs were
$120,021 to collect 248.3 tons of refuse during the
monitoring program. As previously mentioned, in
Section IV, all economic data have been adjusted to
October 1975 dollars.
Conventional Systems --
Three types of alternative refuse collection
systems were used for comparison. One system, system
A, consisted of a chute fed compactor unit at the base
of each MFHR building and containers at the remaining
buildings and other locations. Table 34 provides a
further description of the system. The site management
provided a bulk waste collection service, maintenance
of container pens, and labor to move the container to
areas accessible to the collection vehicles. The
manpower required to operate this system is shown in
Table 35.
142
-------
Table 34. DESCRIPTION OF SOLID WASTE MANAGEMENT SYSTEM ALTERNATIVES A AND B
co
Location
Chute Fed Compactor Chute Fed Loose Refuse Per Changes Per
and Two Containers Containers Week (Cubic Yards) Week
Camci
De.scon Deck West
Descon Deck East
Descon Concordia
Shelley B West
Shelley B East
Shelley A
Shelley A South1
153 MFHR X
12 MFLR
24 MFMR
105 MFHR X
10 MFMR
30 MFMR
152 MFHR X
31.9
X 5.0
X 13.4
20.2
X 3.8
X 11.3
42.8
X 2.5
130.9
3
2
5
2
2
4
3
2
23
This building was a small shed used to collect recreational and yard waste only.
-------
Table 35. SITE MANPOWER REQUIREMENTS FOR SYSTEM ALTERNATIVE A
Task
Change containers
Daily collection
Clean pens
Clean compactor rooms
Repair pens
Man-hours Per Task
1.5 man-hours per change
6.0 man-hours per day
0.5 man-hour per pen per week
0.5 man-hour per room per week
2.0 man-hours per week
Labor supervision at 15 percent of other labor requirements
Man-hours Per Year
1 ,794
2,190
130
104
104
Total
4,322
649
4,971
-------
System B is similar to system A (Table 34) except
for manpower requirements. In system A, the site
management provides all the labor. However, in system
B, a private contractor is responsible for moving
containers to and from the collection vehicles.
Requirements for the manpower needed are given in
Table 36.
System C consisted of vertical trash chutes with
containers at their bases. No compactor was utilized
and refuse merely collected in the containers. This
system is described further in Table 37. The site
management provided a bulk waste collection service,
maintenance of container pens, and labor to move the
containers to areas accessible to the collection ve-
hicles. The manpower required by the system is pre-
sented in Table 38.
The annual costs for systems A, B, and C are pre-
sented in Tables 39, 40, and 41 respectively.
Cost Ana lysis
Comparison with Conventional Systems --
The comparison of the annualized costs of the PTC
system with the three refuse collection systems is
shown in Table 42. It can be seen that the PTC system
is, depending on the system it is compared to, from 1.6
to 4.6 times as expensive to operate. This is based
upon the observed loading of 248.3 tons per year. The
costs are disaggregated into the following categories
and are presented in Figure 76.
• Capital cost,
• Site labor cost,
t Hauling and sanitary landfill cost, and
t Contingency cost.
The significantly higher cost of the PTC system is
attributed to the capital cost. This cost greatly
exceeded the annual cost for the three conventional
systems and accounted for about three-fourths of the
annual cost for the PTC system.
The annual costs for all four systems were pro-
jected to the year 1995 in Figure 77. Indices for
capital, labor, material, and energy costs were gen-
erated for the years 1975 to 1995 from previous work
(see Appendix N). These data were used to project the
future operating costs of each refuse collection sys-
tem, so that these costs can be compared.
145
-------
cr>
Task
Table 36. SITE MANPOWER REQUIREMENTS FOR SYSTEM ALTERNATIVE B
Man-hours Per Task Man-hours Per Year
Daily collection
Clean pens
Clean compactor rooms
Repair pens
6.0 man-hours per day
0.5 man-hour per pen per week
0.5 man-hour per room per week
2.0 man-hours per week
Labor supervision at 15 percent of other labor requirements
Total
2,190
130
104
104
2,528
379
2,907
-------
Table 37. DESCRIPTION OF SOLID WASTE MANAGEMENT SYSTEM ALTERNATIVE C
Location
Number of 3 Cubic
Yard Containers
Loose Refuse Per
Week (Cubic Yards)
Changes Per
Week
Camci
Descon
Desco
n
Descon
Shell
Shell
Shell
Shell
ey
ey
ey
ey
Dec
Dec
k
k
West
East
Concordia
B
B
A
A
Wes
Ea
s
Sou
t
t
th1
153
12
24
105
10
30
152
MFHR
MFLR
MFMR
MFHR
MFMR
MFMR
MFHR
3
1
2
2
1
1
4
1
15
31
5
13
20
3
11
42
2
130
.9
.0
.4
.2
.8
.3
.8
.5
.9
15
2
6
10
2
4
20
1
60
'This building was a small shed used to collect recreational and yard waste only.
-------
-pi
00
Table 38. SITE MANPOWER REQUIREMENTS FOR SYSTEM ALTERNATIVE C
Task Man-hours Per Task Man-hours Per Year
Change containers 1.5 man-hours per change 4,680
Daily collection 6.0 man-hours per day 2,190
Clean pens 0.5 man-hour per pen per day 390
Clean container room 0.5 man-hour per week 26
Repair pens 7.5 man-hours per week 390
7,676
Labor supervision at 15 percent of other labor requirements 1,152
Total 8,828
-------
Table 39. ANNUAL COST FOR THE REFUSE COLLECTION SYSTEM ALTERNATIVE A
Initial Cost
Capital Costs
3 compactors and 6 containers
(2 cu yd each) $19,230
5 containers (3 cu yd each) 1,050
1 container (25 cu yd ) 2,050
5 pens for 3 cu yd containers 1,350
Building chutes and charging
stations 22,623
Operating and Maintenance Costs
Labor-- 4,322 man-hours/year at $3.00/hr with
Labor supervision-- 649 man-hours/year at $5.
Compactor repair material at 1 percent of ini
Lifetime
(Years)
10
7.5
7.5
7.5
40
20 percent fringes
Carrying
Charge
0.145
0.179
0.179
0.179
0.079
00/hr with 20 percent fringes
tial cost
Pen repair material at 1 percent of initial cost
Hauling and sanitary landfill fees
Annual
Cost
$ 2,815
188
367
242
1,796
$5,408
$15,559
3,894
193
14
6,765
$26,425
Percent
8.8
0.6
1.2
0.8
5.6
17.0
48.9
12.2
0.6
0.0
21.3
83.0
$31,833 100.0
-------
Table 40. ANNUAL COST FOR THE REFUSE COLLECTION SYSTEM ALTERNATIVE B
Lifetime Carrying
Initial Cost (Years) Charge
Capital Costs
3 compactors and 6 containers
(2 cu yd each) $19,320 10 0.145
5 containers (3 cu yd each) 1,050 7.5 0.179
1 container (25 cu yd ) 2,050 7.5 O.T79
5 pens for 3 cu yd containers 1,350 7.5 0.179
Building chutes and charging
stations 22,623 40 0.079
Operating and Maintenance Costs
Labor— 2,528 man-hours/year at $3.00/hr with 20 percent fringes
Labor supervision-- 380 man-hours/year at $5.00/hr with 20 percent fringes
Compactor repair material at 1 percent of initial cost
Pen repair material at 1 percent of initial cost
Hauling and sanitary landfill fees
Annual
Cost
$ 2,815
188
367
242
1,796
$5,408
$ 9,101
2,280
193
14
9,235
$20,823
Percent
10.7
0.7
1.4
0.9
6.9
20.6
34.7
8.7
0.7
0.1
35.2
79.4
$26,231 100.0
-------
Table 41. ANNUAL COST FOR THE REFUSE COLLECTION SYSTEM ALTERNATIVE C
Initial Cost Lifetime (years) Carrying Change Annual Cost Percent
CAPITAL COSTS
15 containers $ 3,150 7.5 0.179
(3 cu yd each)
1 container 2,050 7.5 0.179
(25 cu yd)
15 pens for 4,050 7.5 0.179
3 cu yd containers
Building chutes 22,623 40 0.079
and charging
station
OPERATING AND MAINTENANCE COSTS
Labor—7,676 man-hours/year at $3.00/hour with 20% fringes
Labor supervision--!, 152 man-hours/year at $5.00/hour with
20% fringes
Pen repair material at 1% of Initial cost
Hauling and sanitary landfill fees
564
367
726
1.796
3,453
27,634
6,912
40
36,660
71 ,246
0.7
0.5
1.0
2.4
4.6
37.0
9.2
0.1
49.1
"9177
74,699 100.0
-------
en
ro
Table 42. COMPARATIVE ANNUAL COSTS FOR THE PTC SYSTEM AND
THREE CONVENTIONAL SOLID WASTE MANAGEMENT SYSTEMS
Cost/
System
PTC System
System A
System B
System C
Annual Cost
$120,021
31,833
26,231
74,699
Dwelling Unit/
Year
$247
66
54
154
Cost/
Capita/ Year
$96
25
21
60
Cost/Ton
$483
128
106
301
-------
LEGEND
- Capital Cost
- Contingency Cost
- Hauling and Sanitary
Landfill Cost
- Site Labor Cost
PTC A B C
Solid Waste Management Systems
FIGURE 76. Annual costs for the PTC system and three
alternative conventional solid waste management systems
153
-------
Legend
03
O)
S-
10
T3
£Z
O
.c
CO
O
O
c
O
O
0)
o
CJ
220-
200-
180-
160-
140-
120-
100.
80-
60-
40-
20-
System A
PTC System
System C
System B
1975
1980
1985
Year
1990
1995
FIGURE 77. Annual cost projections for the PTC system and
three alternative conventional solid waste management systems,
154
-------
The projected annual cost for the PTC system in-
creased at about the same rate as systems A and B.
Both of these conventional systems used compactors.
The annual cost for the remaining system, system C,
increased at,about twice the rate as the PTC system.
This system was highly labor intensive.
Comparison with Design Estimates --
The PTC system was designed to be cost effective
for the designed loading of 1300 tons of refuse per
year. In addition, the system components were designed
to handle an additional 25 percent in loading over its
life. Thus, the system could collect a total of 1600
tons of refuse per year.
The analysis showed, as demonstrated in Figure 78,
that the PTC system could be cost effective if it is
operated at the design capacity. Operating at the ob-
served loading of 248.3 tons per year, the cost to
collect and dispose of refuse was $483 per ton. How-
ever, if the system operated at the design loading of
1300 to 1600 tons of refuse per year, the cost would
vary between $116 to $99 per ton respectively. Com-
paring these figures to the costs of operating the
three conventional systems at the design loadings for
the PTC system, it can be seen that operating the PTC
system at design loadings would be cost effective.
System Cost in dollars/ton
System A 123 - 131
System B 104 - 109
System C 331 - 341
PTC System 99 - 116
RESIDENT ACCEPTANCE EVALUATION
The resident acceptance of the PTC system was pre-
sented in a separate document. The results from the
previous report are summarized to investigate the fol-
lowing subjects :
• The type of resident at the site;
• The resident awareness of the requirements
of the PTC system; and
t The resident and management acceptance of
the PTC system.
155
-------
100-
200 400 600 800 1000 1200 1400 1600 1800 2t>OO 2200
Amount of Collected Refuse (tons/year)
FIGURE 78. Annual collection costs for the
PTC system vs. amounts of refuse collected.
156
-------
A representative sample of the households for 164 out
of a total of 486 dwelling units at the site were
surveyed.
Type of Resident
The residents at the site are described by retire-
ment status, number of adults, and number of children.
About 24 percent of the residents were retired. A
distribution of residents by numbers of adults and
children is presented in Table 43. A typical dwelling
unit has roughly about two adults and one child.
Resident Awareness of System Requirements
The residents were surveyed to determine their
awareness of the requirements for the PTC system. The
results of the survey indicated that almost all of the
tenants were cognizant of the use and capabilities of
the PTC system. The survey indicated that 98 percent
of the residents realized that the site management was
responsible for the operations of the system. Further-
more, 95 percent of the residents were aware that
large, bulky waste would be collected by contacting the
site management. However, there was some confusion on
the part of the residents about the requirement of
segregating refuse.
The survey showed that the residents were confused
over the policy of segregating refuse before disposal
in the trash chutes. Table 44 shows the percentage of
residents that actively participated in refuse separa-
tion. Out of the 164 residents interviewed, 108 or 66
percent said they participated in separating refuse
while, 56 or 34 percent said they did not.
It was observed during the monitoring period that
some tenants were not only more aware of their respon-
sibilities to the PTC system, but more responsive as
well. These tenants posted their own signs to inform
other residents of how to use the system properly.
Figure 79 shows some of the typical signs found at the
charging stations.
Resident and Management Acceptance of the System
The residents and site management were interviewed
to determine whether they felt that the PTC system
adequately collected refuse. The results of the resi-
dents' evaluation of the system is shown in Table 45.
157
-------
Table 43. POPULATION DISTRIBUTION OF RESIDENTS
Number
per
4 or
of Adults
Unit
0
1
2
3
more
Number of
Units Sampled
0
35
1T3
12
4
164
Number of
Adults
0
35
226
36
=16
> 313
Number of
Children per Unit
0
1
2
3
4 or more
Number of
Units Sampled
98
36
20
8
2
164
Number of
Children
0
36
40
24
^8
2 108
Total Number
of Persons
0
71
226
60
=24
? 421
tn
oo
-------
Table 44. EXTENT OF RESIDENT PARTICIPATION
IN SEPARATING SOLID WASTE
1 Number of Residents Percent of Resident
Item Participating2 Participation
Glass 96 58.5
Bulky waste 81 49.4
Plastic 27 16.5
Food waste 0 0.0
Newspaper and magazines 90 54.9
Cans 1 0.6
Tenants separated their1 refuse into these oategoriet
2
A total of 164 residents were interviewed.
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CT)
O
FIGURE 79. Typical signs posted by
to be more considerate when
the tenants to inform other tenants
they dispose their refuse.
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Table 45, RESIDENT EVALUATION OF PTC SYSTEM ADEQUACY
Number of Residents Percent of
Problem Description Reporting Problems^ Dissatisfied Residents
Chute blockages 23 14.0
Small size of chute charging 9 5.5
stations
Did not use PTC system 2 1.2
Compactor mechanical problems 1 0.6
Small size of chute door opening _J_ 0.6
Total 36 21.9
A total of 164 residents were interviewed.
-------
The evaluation showed that over one percent of the
tenants did not use the PTC system, and that about 78
percent of the tenants were satisfied with the perform-
ance of the system. There was one resident who felt
that the PTC system was environmentally inadequate, but
did not state the deficiencies.
The site management felt that their services could
have been minimized if the PTC system had performed
properly and if the tenants had correctly used the sys-
tem. Due to the considerable number of system malfunc-
tions and the large quantities of litter in the dis-
charge valve rooms and charging stations, the management
had to provide extensive labor efforts to repair and
clean the system. The management also felt that many
of these efforts were attributable to the low level of
resident cooperation in properly utilizing the system.
Several specific problems were cited. They include:
• Residents breaking PTC system components by
forcing large, bulky wastes into the chute
door;
• Residents causing chute blockages by not
pushing refuse all the way down the chute;
• Residents leaving food wastes and moist
garbage on charging station floors or in
hallways and stairways; and
• Residents improperly wrapping refuse which
created unsanitary and unhealthy conditions
in discharge valve rooms, especially during
periods of operating problems.
The site management implemented many policies to
correct these problems by educating residents in the
proper use of the PTC system. One example of these
policies is a notice (Figure 80) posted on all charging
stations doors, that listed certain system regulations.
ENVIRONMENTAL EVALUATION
The PTC system was examined to determine the
environmental effects of the system. The following
topics were considered:
• Sanitation effects such as litter, clean-
liness, odor, and presence of rodents
and vermin;
162
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Summit Plaza
7OO NEWARK AVENXTE . JERSEY CITY. N. J. O73O8
(3Ol) 963-0000
H/25/75
TO ALL SUMMIT PLAZA TENANTSi
WITH THANKSGIVING APPROACHING, FOLLOWED SOON AFTER BY CHRISTMAS, WE WANT
TO REMIND EVERYONE TO BE EXTREMELY AWARE OF THE GARBAGE PROBLEMS WE HAVE
BEEN HAVING AT SUMMIT PLAZA, AND TO ACT ACCORDINGLY.
NUMEROUS TENANTS HAVE BEEN LEAVING NEWSPAPERS AND BOTTLES AND CANS AND
OTHER TRASH ON THE FLOOR OF THE COMPACTOR CLOSETS, AND OUTSIDE IN THE
HALLS.
DO NOT LEAVE ANY ITEMS, ESPECIALLY FOOD, OUTSIDE THE CHUTE. GARBAGE ATTRACTS
VERMIN. ALL GARBAGE SHOULD BE PUSHED ALL THE WAY. DOWN THE CHUTE1
THAT INCLUDES SPRAY CANS, RAGS, CLOTHES, NEWSPAPERS, AND PIZZA BOXES, WHICH
SHOULD EE CUT UP TO FIT INTO THE CHUTE — AND NOT FORCED INTO THE CHUTE.
THE ONLY ITEMS THAT CANNOT BE THROWN INTO THE CHUTE ARE THOSE WHICH ARE
PHYSICALLY TOO LARGE TO GET INTO THE CHUTE EASILY.
IT IS EXTREMELY IMPORTANT THAT YOU DO NOT FORCE LARGE OBJECTS LIKE CARD-
BOARD BOXES INTO THE CHUTE.
WHEN YOU FORCE .SOMETHING INTO THE CHUTE, AS MANY TENANTS HAVE IN THE PAST,
THE ENTIRE TRASH COLLECTION SYSTEM JAMS FOR ALL 4 BUILDINGS AT SUMMIT
PLAZA, AND BREAKS DOWN.
TENANTS THEMSELVES HAVE BEEN RESPONSIBLE FOR MANY OF "THE PILE-UPS WE HAVE
HAD IN THE CHUTE, CAUSING ODORS AND VERMIN TO COLLECT.
IT IS PARTICULARLY IMPORTANT THAT YOU EXERCISE' JUDGMENT DURING VACATIONS
AND WEEKENDS WHEN MORE PEOPLE ARE AT HOME', AND THERE ARE MORE ITEMS TO GO
DOV;N THE CHUTE — WRAPPINGE, FOOD, ETC.
SOME TENANTS HAVE ACTUALLY THROWN FURNITURE SUCH AS CHAIRS INTO THE CHUTE.
AND THE SYSTEM HAS BROKEN DOWN BECAUSE OF IT.
IF YOU ARE IN DOUBT ABOUT WHETHER OR NOT SOMETHING CAN GO DOWN THE CHUTE,
HOLD ONTO IT AND CALL THE MANAGEMENT OFFICE THE FOLLOWING MONDAY, OR THE
FOLLOWING DAY.
AND REMEMBER — CHRISTMAS TREES ARE NOT TO BE THROWN DOWN THE CHUTE. THEY
WILL HAVE TO BE PICKED UP BY OUR PORTERS UPON REQUEST.
ALSO, DO NOT THROW DOWN CURTAIN RODS, BROOM HANDLES, OR ANY VERY LONG OBJECT.
PLEASE 32 CONS-IDERATE OF YOUR NEIGHBORS, OF OUR EMPLOYEES — AND ULTIMATELY
OF YOUHS2LV3S — SO THAT WE WILL ALL HAVE A MORE ENJOYABLE HOLIDAY.
FIGURE 80. Site management regulations on the
usage of the PTC system.
163
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8 Air quality of the internal system air and of
the exhaust air, including airborne particu-
lates and viable particles;
• Noise levels produced by the refuse
collection activities compared to background
noise levels and acceptability to residential
use of the system;
• Aesthetic qualities attibuted to the
system; and
9 Advantages of a reduced number of
service vehicle visits to the site
to pick up and dispose of refuse.
These subjects are compared to the conditions declared
in the design specifications.
Sanitation Effects
The sanitation effects of the PTC system were ob-
served and examined to determine whether the refuse
collection activities of the system were more sanitary
than conventional systems. The aspects studied in
detail were litter, cleanliness, odor, and the presence
of rodents and vermin. The system, generally, was
clean. Nevertheless, the conditions around the dis-
charge valve rooms and chute charging stations dras-
tically deteriorated during periods of prolonged system
malfunctions.
As was the customary procedure, some refuse such
as large bulky items, cardboard boxes, glass bottles,
and newspaper, were left as chute charging stations
(Figure 81) and at designated pick-up areas outside the
buildings. The site management provided a daily col-
lection service for these items. Thus, the effects of
litter, odor and vermin were minimal. However, the
charging stations at the Descon Concordia and Camcf
buildings did have roaches. It was reported by the
site management, that the roaches would first appear in
the kitchens of new tenants and migrate over to these
chargi ng stations.
The discharge valve rooms were constantly littered
with refuse that escaped from the chute storage sections
Since these discharge valve rooms were located in
underground vaults, and not easily accessible to site
164
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FIGURE 81. Refuse left at the charging stations
which was collected daily by site personnel.
personnel as seen in Figure 82, the litter was not
cleaned up. As a result, ants, roaches, and flies were
prevalent. In particular, the discharge valve rooms at
Descon Concordia experienced sanitation problems. The
room was located near a mechanical room, which con-
stantly had water seepage from traps and leaks in the
steam lines. The combination of the hot, humid atmos-
phere and decaying refuse provided excellent breeding
conditions for vermin.
The compactor room was also continually littered
which was caused by site personnel. They would haul
bulk waste to the room and dispose of it either in the
open top container provided for the bulk waste or on
the floor, as seen in Figure 83. The litter would not
only fall into the channels for the container handling
equipment and foul the chains and other equipment, but
caused problems with odor, cleanliness, and vermin.
165
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FIGURE 82. Discharge valve room at Camci
showing the amount of litter in the room.
The site personnel must climb down the
ladder to clean the room.
FIGURE 83. Bulk solid waste left in the compactor
room, even though an open-top 25-cubic yard
container is provided for this waste.
166
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The sanitation effects such as litter, cleanli-
ness, odor, and insects were compounded when the system
experienced prolonged downtime. With the system not
operating, site personnel had to collect refuse manu-
ally. To accomplish this, site personnel removed the
chute storage sections. This allowed refuse from the
chutes to fall freely into the discharge valve rooms
(Figure 84). Then, the refuse could be picked up by
hand. However, this contributed to unclean conditions,
breeding places for vermin, and odors. Matters were
intensified when the weather was hot and humid.
In an effort to improve this situation, site per-
sonnel attached large bags to the bottom of the storage
sections, as shown in Figure 85. This helped to
alleviate the sanitation problems in the discharge
valve rooms, but in so doing caused another problem. As
the bags became filled, the chute would fill up.
Eventually the chute would become blocked and unable to
accept more refuse. When this occurred, residents
would leave their refuse at the chute charging stations
and in the hallways (see Figure 86). This resulted in
unclean and unhealthy conditions in the residential
dwellings themselves. It should be noted that chute
blockages during normal PTC system operations also
caused these same conditions.
An effort was made by the site management to
control the vermin at the site which also included the
PTC system. An exterminator was employed to visit the
comp1 ex monthly.
Air Quality - -
The air pollution levels associated with the PTC
system were measured and compared to ambient conditions
and Federal regulations. The total airborne particulate
matter in the system air and exhaust air were compared
to the concentration in ambient air and the EPA National
Ambient Air Quality Standards (Federal Regulations CFR
50: 36 FR22384, November 25, 1971). Table 46 reports
these Federal standards.
167
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CT>
00
FIGURE 84. Refuse scattered at the discharge valve rooms
at Descon Concordia and Camci during periods
of prolonged system downtimes.
-------
FIGURE 85. Bag placed at base of storage section at Shelley A
to collect refuse during prolonged system downtimes.
FIGURE 86. A typical chute charging station filled with refuse
during a prolonged system malfunction. Note that the door is
only partially open because of additional refuse behind the door
169
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Table 46. NATIONAL AMBIENT AIR QUALITY STANDARDS
FOR PARTICULATE MATTER
Primary Standard Secondary Standard
33 33
micrograms/m grains/ft micrograms/m grains/ft
Annual geo-
metric mean 75
Maximum 24-hour
concentration 260
3.28x10"
11.35x10"
60
150
2.62x10"
6.55x10"
The results of the total airborne particulate
tests on the system air and the system exhaust air are
presented in Table 47. The results show that even
though the internal air of the PTC system exceeded the
Primary Standard during all three test periods, the
exhaust air only exceeded the Secondary Standard once.
The ambient air exceeded the Primary Standard every
time. Thus, it can be deduced that the dust collector
was able to filter the system air such that it removed
about 85 percent of the total airborne particulate
matter. Further, the system exhaust air actually had a
lower concentration of total airborne particulate than
the ambient air.
Table 47. RESULTS FOR TOTAL AIRBORNE PARTICULATE
MATTER SAMPLING TESTSl
Date
February 24-28, 1975
June 23-27, 1975
January 5-9, 1976
Average
System Air System Exhaust Air Ambient Air
4.73
6.07
30.42
13.74
1.
2.
2.
47
74
11
2.11
3.92
4.45
3.54
3.97
Total airborne particulate matter is reported in
10~ grains/ou ft.
The viable particle concentrations of the system
exhaust air and internal air were measured and compared
to ambient air. The results for three test periods are
presented in Table 48. The results indicate that the
dust collector removed about 48 percent of all viable
particles. The results also show that the viable par-
ticle concentration in the system exhaust air was lower
than the concentration in the ambient air.
170
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Table 48. RESULTS FOR VIABLE PARTICLE
CONCENTRATION SAMPLING TESTS1
Date System Air System Exhaust Air Ambient Air
February 24-28, 1975 4.5 2.3 2.7
June 23-27, 1975 8.3 5.8 10.0
January 5-9, 1976 9.0 3.3 4.6
Average 7.3 3.8 5.8
The viable particle concentration is reported in
colonies/cu ft.
Both the particulate matter and viable particle
concentrations from the system exhaust air were lower
than the ambient air concentrations, and thus complied
with the design specifications.
Noise Levels --
A comparative analysis of the noise levels attrib-
uted to the refuse collection activities for the PTC
system to the ambient noise levels and to OSHA stan-
dards was conducted. There was no indication of exces-
sive noise levels from the PTC system. In many cases,
the ambient noise levels in the public rooms adjacent
to the discharge valve rooms were greater than the
noise attributed to the PTC system operations.
The noise levels in the CEB ranged from 74 to 85
db due to the continuous operation of the total energy
plant. The noise levels increased to between 80 to 90
db during operations of the PTC system, however, these
levels were transient and lasted less than six minutes
per hour. These noise levels were well within the
regulations promulgated by OSHA, and presented no
problems.
Noise was also produced by the pull-on container
truck when the refuse containers were changed. Never-
theless, the noise level was about 95 db and only
lasted for about ten minutes. This activity occurred
once per week.
When the PTC system was operating properly, the
noise levels from the system at the site were less than
ambient noise levels. Therefore, tenants were unaware
of noise from system operations and the system was
found to be acceptable for residential use.
171
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Aesthetics .--
The cfesign of the PTC system considered features
to preserve the site aesthetics. The following major
system components were either housed in the CEB or
below grade:
Main transport line,
Collection hopper,
Dust collector,
Main exhausters,
Vent fan,
Compactor and container handling system, and
Central control panel.
The discharge valve rooms were placed in the basement
areas of each building. The building chutes were
designed to be internal to the structure, or blend into
the site. Figure 87 shows one charging station on the
Descon Concordia deck.
A bulk waste collection service was provided by
the site personnel. The residents would leave large
boxes, furniture, and other large refuse outside each
building. Trash receptacles were provided, but there
were too few to collect all the refuse. Thus, a large
portion of the refuse was left on the ground detracting
from the site aesthetics. Figures 88 and 89 show
refuse at the Shelley A and Camci buildings, respec-
tively. This refuse was collected by small carts
(Figure 90).
Service Vehicles --
A service vehicle came to the site once each week
to exchange refuse containers. An empty container was
delivered and the full container was hauled to a sani-
tary landfill. The duration of each visit was about
twenty minutes and the vehicle, a pull-on container
truck, produced less noise than a typical rear-packer
vehicle. The site access road for service vehicles was
planned to minimize the visual impact or these vehicles
on the site. The success of these features was demon-
strated in the tenant survey report. The majority of
the residents were unaware that a private contractor
hauled the site refuse away.
172
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FIGURE 87. One charging station at the deck
of Descon Concordia, showing how the design
preserves site aesthetics.
FIGURE 88. Bulk waste left daily outside Shelley
A to be picked up by site personnel.
173
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FIGURE 89. Bulk waste left daily outside
Camci to be collected by site personnel.
FIGURE 90. A workman with a small chart about
4'x4'x4' in size used for collecting refuse.
174
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REFERFNCES
1. "Survey of User Acceptance of the Solid Waste
Removal Systems at Operation Breakthrough Sites,"
Hittman Associates, Inc., and Applied Management
Science, Inc., HUD/EPA sponsored, Cincinnati,
Ohio, unpublished.
2. "Evaluation of the Refuse Management System of
Operation Breakthrough Sites," Hittman Associates,
Inc., HUD/EPA sponsored, Cincinnati, Ohio, HUD-EPA-
HAI-1, unpubli shed.
3. "3rd Quarterly Cost Roundup," Engineering News
Record, September 19, 1974.
4. "ENR Indexes Show 73 Costs Accelerating, Engineering
News Record, March 22, 1973.
5. "4th Quarterly Cost Roundup," Engineering News
Record, June 27, 1975.
6. "Construction Scoreboard," Engineering News Record,
June 27, 1974.
7. "Construction Scoreboard," Engineering News Record,
October 16, 1975.
8. "Construction Scoreboard," Engineering News Record,
October 24, 1974.
9. "Construction Scoreboard," Engineering News Record,
January 3, 1974.
10. "Construction Scoreboard," Engineering News Record,
July 25, 1974.
11. "Construction Scoreboard," Engineering News Record,
August 22, 1974.
175
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12. "Construction Scoreboard," Engineering News Record,
September 26, 1974.
13. "Construction Scoreboard," Engineering News Record,
November 21, 1974.
14. "Construction Scoreboard," Engineering News Record,
December 19. 1974.
15. "Construction Scoreboard," Engineering News Record,
January 16, 1975.
16. "Construction Scoreboard," Engineering News Record,
February 20, 1975.
17. "Construction Scoreboard," Engineering News Record,
March 20, 1975.
18. "Construction Scoreboard, "Engineering News Record,
April 24, 1975.
19. "Construction Scoreboard," Engineering News Record,
May 22, 1975.
20. "Construction Scoreboard," Engineering News Record,
June 26, 1975.
21. "Construction Scoreboard," Engineering News Record,
July 17, 1975.
22. "Construction Scoreboard," Engineering News Record,
August 21, 1975.
23. "Construction Scoreboard," Engineering News Record,
September 18, 1975.
24. "Construction Scoreboard," Engineering News Record,
November 13, 1975.
25. "Construction Scoreboard," Engineering News Record.
December 18, 1975.
176
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APPENDIX A
TEST PLAN FOR MEASUREMENT OF TOTAL
AIRBORNE PARTICULATES GENERATED BY THE
PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
This procedure was used to determine total airborne
particulate matter generated by the pneumatic trash
collection system at the Operation Breakthrough site
in Jersey City, N.J. Tests were performed on tnree
occasions. On each occasion three locations were
tested each day for five days. The test consists of
air sampling by the high volume method. Three loca-
tions were sampled simultaneously: the outside air
adjacent to an air intake, the system air taken from
the hopper, and the system exhaust air. The total
particulate concentrations were determined for each
location by dividing the weight gains of the filters
by the volume of air sampled. Comparison of the
outside air with the hopper sample gave a measure of
air quality within the system prior to filtration.
Filter efficiency was determined by a comparison of
the hopper sample with the exhaust sample. Comparison
of the exhaust air with the outside air gave a measure
of the overall effect of the system on air quality.
177
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PROCEDURE
1. Fifteen filters are required on each occa-
sion for the test. At least twenty filters
should be processed through steps 2 to 7 in
order to have a few extra filters in case of
difficulty.
2. Visually inspect each filter to be used.
Hold the filter up to a light source and
look for pinholes, loose particles, or other
defects. Discard filters with visible
imperfections.
3. Number each filter on two diagonally oppo-
site corners with a felt tip pen or other
suitable marker.
4. Allow the filters to come to equilibrium in
a standard conditioning environment for 24
hours. This environment should have a
relative humidity less than 55% (variation
in the 0 to 55% range is not a serious
problem). The conditioning environment must
be easily reproducible. If a dessieating
chamber is used for the conditioning environ-
ment, an indicator dessicant such as activated
alumina should be selected. This dessicant
is checked every day and replaced when
necessary as indicated by a color change.
Temperature should be maintained within + 5°F
duringequilibration.
5. Check the calibration of the analytical
balance by weighing a standard weight.
Actual and measured values should be within
0.5mg. If they are not, check the balance
with other weights. Record actual and
measured weights in the lab notebook.
6. Weigh each filter on the analytical balance
within 5 minutes of removing it from the
conditioning environment. Record filter
number and weight.
7. Place each weighed filter in an envelope to
protect it from damage. Label the envelope
with the filter number. Care must be exer-
cised to prevent folding or creasing the
filters before use.
178
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8. If the sampler is located in a shelter,wipe the
inside surfaces of the shelter clean of dust
and loose particles before installing a clean
filter. Install the filter on the sampler at
its sampling location. Place the filter on the
wire screen rough side up. Center the filter
on the screen so there is a 1/2 inch border.
Tighten the wingnuts so that the rubber gasket
makes an airtight seal against the fact of the
filter. Tighten diagonally opposite nuts first
to prevent distortion of the frame and give a
more even tightening. Avoid tightening exces-
sively since this might cause the filter to
stick to the gasket. Record filter number,
location, and date.
9. Turn on the sampler and let it warm up for at
least 5 minutes. Read the flow rate of air
through the sampler with a flow rate meter. The
flow rate meter consists of a vacuum gauge con-
nected to the exhaust end of the sampler
blower. The gauge calibration is established by
comparison with a standard measurement done in
the laboratory previous to taking samples at
the site. Refer to the separate section entit-
led Sampler Flow Rate Calibration for details
of the procedure. Record initial flow rate and
starting time. If the temperature or pressure
of the air at the time of sampling differs sig-
nificantly from the temperature and pressure of
air at the time of gauge calibration, flow rate
should be adjusted. The following equation
should be used.
/T2 Pl\ W2
Q2 = Ql \T1 P2/
where:Q-] is the flow rate read from the gauge
Q2 is the adjusted flow rate
T-| is the temperature at the time of gauge
calibration expressed in °R
T2 is the temperature at the time of
sampling expressed in °R
PI is the pressure at the time of gauge
calibration expressed in inches of
mercury
179
-------
P_ is the pressure at the time of sampling
expressed in inches of mercury.
10. Collect the sample. Sampling will be performed
on three occasions. On each occasion samples
will be collected from three locations: the
outside air adjacent to an air inlet, system
air from the hopper, and exhaust air from the
system. A sample will be collected from each
location each day for five consecutive days.
11. Samplers at the exhaust and air inlet valve can
be allowed to run continuously during the day.
The sampler at the hopper cannot be allowed to
run continuously because operation of the PTC
system creates a pressure drop that could re-
duce or'entirely cancel the flow of air through
the sampler. The hopper sampler will be opera-
ted for 15 minutes beginning approximately 2
minutes after each cycle of the PTC system.
Record time and duration of operation for this
sampler each time it is turned on.
12. Read and record the flow rate at the end of
the sample collection period. The-final flow
rate should not be less than 20 ft /min or
the motor will heat up and a valid sample is
not obtained. Record the stop time.
13. Remove the exposed filter from the supporting
screen of the sampler by grasping it gently at
the ends (not the corners) and lifting it up-
ward. Inspect for leakage which might bias
results. Check for pieces of filter sticking
to the gasket.
14. Fold the filter lengthwise with the exposed
side in. Use a large paper clip at each end to
keep the filter from unfolding. Return the^
filter to the properly numbered envelope for
storage until conditioning and weighing in the
1aboratory.
15. It should be noted if there were any power
outages or other unusual conditions during the
sampling period which might, affect the results.
16. Allow the exposed filter to come to equilibrium
for 24 hours in the same conditioning environ-
180
-------
ment used for the clean filters in step 4.
Time spent in the conditioning environment
should be constant within a few hours for all
filters since some samples show a continued
weight loss for several days.
17. Repeat step 5.
18. Repeat step 6 using the exposed filters.
19. Calculate the weight of the sample on each
exposed filter using the clean weight from step
6 and the exposed weight, from step 18.
20. Calculate the average flow rate for each sample
by averaging the initial flow rate from step 9
and the final flow rate from step 12.
21. Calculate the time interval over which the
sample was taken. For the hopper samples it will
be necessary to compute the length of each of
the short intervals and then add the intervals
to get total sampling time.
22. Take the product of average flow rate from step
20 with the sample interval from step 21 to get
total volume of air sampled.
23. Compute the equivalent of the sampled volume at
standard temperature and pressure using the
formul a:
v2 = TI P2 VT
where: V] is the sampled volume computed in
step 22
Vo is the equivalent of the sampled volume
at standard temperature and pressure
T] is the temperature of the sampled air
as given by weather data for the site
(expressed in °R)
T2 is the standard temperature 70°F which
must be expressed at 530°R
P] is the pressure of the sampled air as
given by weather data for the site (in
inches of mercury)
181
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?2 is the standard pressure 29.92 inches
of mercury
To and P? could be chosen to be any convenient
values but the same values must be used for all
samples.
24. Express the weight from step 19 in grains and
the volume \/2 from step 23 in cubic feet. Take
the quotient to find particulate concentration
in grains per cubic foot for each sample.
25. Average the particulate concentrations for each
location over the five day period.
Sampler Flow Rate Calibration
Prior to using the high volume air sampler it is
necessary to calibrate the flow rate meter used with it.
The flow rate meter could be either a vacuum gauge or a
manometer, Flow rate is measured by connecting the meter
to the pressure tap at the outlet end of the blower motor,
Pressure read on the meter indicates flow rate.
To translate the pressure reading on the flow meter
into a flow rate a meter calibration curve must be estab-
lished in the laboratory. A Sierra Instruments Model 330
flow calibrator is used. The procedure is as follows:
1. Mount the Model 330 at the intake end of the
sampler. Connect a manometer to its pressure
tap.
2. Connect the vacuum gauge or manometer to be
used as a flow rate meter to the pressure tap
at the exhaust end of the blower motor housing.
3. Connect the sampler's electrical plug to an
autotransformer or other variable voltage*
source. Varying the voltage changes the speed
of the motor and, therefore, the flow rate.
4. Set the voltage to the normal operational
voltage of 115 volts. Pressure reading of the
manometer connected to the Model 330 calibrator
should be 10 to 12 inches of water. Allow the
sampler to warm up for about five minutes.
Check the pressure every minute to make sure
182
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that the flow rate has stabilized. When it
has, proceed with calibration.
5. To construct the calibration curve, vary
voltage to the sampler motor. Begin by settling
voltage to obtain a pressure of one inch in the
manometer connected to the Model 330 calibrator.
Allow the sampler to run for about 15 seconds,
making sure that the pressure reading does not
change significantly. Record the pressure
reading on the flow meter. Continue by setting
the voltage to produce pressure readings on
the calibrator manometer at one inch intervals
from two to twenty inches. Record the flow
meter reading at each pressure. Pressures of
one to twenty inches include flow rates from 20
to 75 cfm, the range normally encountered in
high volume samplers.
6. Repeat step 5 two times. Average flow meter
readings for each pressure from the three trials
Record the average.
7. Record the atmospheric temperature and pressure
during the three calibration runs.
8. Use the average flow meter readings and the
manufacturer's calibration curve for the Model
330 calibrator to construct a calibration
curve for the flow rate meter. The curve
should show flow rate in cfm versus the pres-
sure reading on the flow rate meter.
183
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APPENDIX B
TEST PLAN FOR MEASUREMENT OF TOTAL
AIRBORNE VIABLE PARTICLES GENERATED BY THE
PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
The following procedure was used to measure total
airborne viable particles generated by the pneumatic
trash collection system at the Operation Breakthrough
site in Jersey City, New Jersey. These tests were con-
ducted on three occasions. For each test period three
locations were tested daily for five days. The loca-
tions were at a remote outdoor location for ambient air
conditions, inside the collection hopper for internal
system air conditions and at the exhast vent for system
exhaust air.
The concentrations of the airborne particulates
were sampled by an Andersen 2000 sampler. The total
airborne viable particle concentrations were determined
for each location by dividing the number of colonies by
the volume of air sampled. Comparison of the ambient
air to the system internal air was a measure of air
quality attributed to the system before filtration.
The filter efficiency was determined by a comparison of
the system internal air with the system external
exhaust air. Comparison of the system exhaust air to
the ambient air was a measure of the overall effect of
the system on air quality.
184
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PROCEDURE
One hundred-forty sterilized Petri dishes
filled with Standard Methods agar (plate
count agar) should be prepared for each test
period. Eighteen dishes are required daily
and there should be at least ten more pre-
paired each day in case of accidents and con-
tamination.
The Petri dishes and aluminum covers must be
sterilized before the dishes can be filled
with the plate count agar. Petri dishes can
be placed in an autoclave for decontamina-
tion; however, the aluminum covers must be
decontaminated in a disinfectant and rinsed
well. Both Petri dishes and aluminum covers
are: (1) washed in warm water with a suit-
able cleaning agent, (2) rinsed with tap
water, and (3) rinsed with distilled water.
The Petri dishes and aluminum covers are
sterilized in a hot air sterilizer at 160°C
for two hours.
Twenty-seven ml of melted, sterile plate
count agar is poured into each sterile Petri
dish with an automatic pipette or a 30 ml
syringe with a number 15 or larger needle.
An aluminum cover is placed over each Petri
dish. The Petri dishes with the plate count
agar are inverted and refrigerated until the
test day. The Petri dishes must be at room
temperature before they can be used.
The Andersen 2000 viable particle sampler
should be checked for the proper flow rate of
one cubic foot per minute before each test
period. This can be performed by either a
dry gas meter or a wet test meter.
The six Petri dishes were placed in the six-
stage Andersen sampler. Each dish was visu-
ally inspected for plate count agar, decon-
tamination and water droplets. The Petri
dishes with the water droplets and decontani-
nated areas were not used. The Petri dishes
were placed in each stage of the sampler,
beginning with the lowest (#6) stage. The
185
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aluminum cover was removed and the proper
section for the sampler was placed over the
Petri dish. The entire sampler was loaded
in this manner. A plastic cover was placed
over -the inlet for the sampler, until the
test run was started.
Note: Before the first test period ambient
air, system internal air and system external
air were sampled for 5, 10, 15, 20, and 30
minute intervals to determine suitable sam-
pling time periods. It was noticed that a
short time period would produce very low
colony counts, and that the viable particle
concentrations were inaccurrate- Further-
more, a long time period would produce par-
tially and fully obscured Petri dishes and
invalid colony counts. For valid results
for the viable particle sampling test, the
following sampling time
based on the results of
pi ing:
intervals were made
this initial s a m -
Location
Remote outdoor for
ambient air
Inside collection
hopper for system
internal air
Exhaust vent for sys-
tem external air
Time interval
20 to 30 minutes
10 to 15 minutes
20 to 30 minutes
6. The ambient air, system internal air,and sys-
tem external air were sampled once each day.
The Andersen sampler was loaded as previously
discussed in step 5, and placed at one test
location. The plastic cover to the inlet o*f
the sampler was removed, and the pump was
started. The pump was stopped after the
proper time, as mentioned in step 5, and the
plastic cover was placed on the inlet of the
sampler. The test location, and starting and
stopping times were recorded.
186
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7. The Andersen sampler was unloaded and an
aluminum cover was placed over each Petri
dish. The Petri dishes were inverted.
8. A piece of masking tape was placed on each
inverted Petri dish and was marked with the
sample run number and stage number. These
numbers were also recorded with the other
data.
9. The Petri dishes were incubated at 35°C for
48 hours.
10. The number of colonies on each dish were
counted using a Quebec colony counter. The
Quebec colony counter consists of a source
of illumination, a grid used to keep track
of colonies that have been counted, and an
optical instrument to magnify the colonies
being counted. The total number of colonies
was so low in these tests that every colony
on each Petri dish was counted.
11. The concentration of viable particles were
computed after the colony counts were made.
The concentration was the quotient of the
colony counts divided by the volume of air.
The volume of air was the product of the
elapse time in minutes times the flow rate
which was one cubic foot per minute.
187
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APPENDIX C
TEST PLAN FOR CHARACTERIZATION OF
THE SOLID WASTE CONVEYED BY THE
PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
This procedure was used to characterize solid
waste transported by the pneumatic trash collection
system at the Operation Breakthrough site in Jersey
City, New Jersey. Tests were performed on three occa-
sions. For every occasion, one 300-pound sample of
refuse was removed from the compactor for character-
izing the solid waste. A 5 to 10 pound sample was
placed in a sealed trash bag for determining the mois-
ture content. Moisture content was determined by
weight differences before and after a drying cycle.
Density was determined by measuring sample weight and
volume. Composition of the solid waste passing through
the system was determined by manually separating the
samples into the following 10 categories:
(1) Paper
(2) Fines (Refuse which passed through a
one-inch sieve)
(3) Food
(4) Glass
(5) Metal
(6) Plastic
(7) Textiles
(8) Wood
(9) Rocks
(10) Yard Waste
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PROCEDURE
Sample collection should begin on the first
cycle of the day at 7:00 a.m. Since approxi-
mately 50 pounds of refuse is collected per
cycle, six or seven cycles will be needed to
obtain a sample of the required 300-pound
size. This estimate of the number of cycles
required is based on current operation of
the system at the rate of 30 cycles per day-
In order to obtain data on variation of the
load to the system, the six or seven cycles
used for collecting the sample will be
spaced at intervals of two to three hours.
The cycles used will be those at 7:00 a.m.,
10:00 a.m., 12:30 p.m., 3:00 p.m., 5:30
p.m., 8:00 p.m., and 10:00 p.m.
It will be necessary to have an empty con-
tainer mounted on the compacter before each
cycle and removed from the compactor after
each cycle at the indicated times. Movement
of containers will be done by site manage-
ment personnel.
After each cycle remove the accumulated
refuse from the compacter container. The
refuse will be temporarily stored in plastic
bags of the three or six bushel size. If
the three bushel size is used, approximately
135 bags will be required for collecting the
composite samples, depositing sorted mate-
rial, storage, and final disposal.
Transport the sample to the sorting loca-
tion. Sorting could be done in the room on
the second floor of the central equipment
-building where the hopper, filter, and
exhausters are located.
Weigh and measure the volume of the com-
posite sample after each cycle. Measure the
volume by using a container of known size
such as a bushel basket. Record the number
of times the sample fills the container.
Fill the container from the plastic trash
bag and then dump the contents of the con-
tainer onto a large canvas or plastic sheet
for sorting.
189
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7. Separate one-eighth of the pile for use in a
drying cycle to determine moisture content.
Obtain one-eighth of the tota? by dividing into
halves three times. Weigh the separated portion
and store in a tightly sealed 18 quart plastic
bag. Label the bag with the date and time of
the cycle from which the sample was obtained.
8. Separate the remaining seven-eights of the
sample into the 10 categories described in the
evaluation plan: paper; metal; glass and cera-
mics; textiles; plastic, rubber, and leather;
food waste; garden waste; wood; rocks; and
fines (material which passes a one-inch sieve).
There will be a three bushel trash bag for each
category. As soon as sorting is completed,
seal the bags to prevent evaportation of mois-
ture. If sorting is interrupted, seal the bags
containing both the composite and the sorted
sample until sorting can be resumed.
9. Weigh the bags and record tire weights after
sorting has been completed. When a bag is
filled, replace it with an empty one and con-
tinue sorting after recording which bag was
replaced.
10. At the end of a day of sampling dispose of
the sorted refuse.
11. Return the samples to be used for determining
moisture content to the laboratory. Weigh the
container(s) to be used for holding the samples
during drying to the nearest gram. Fill the
container(s) with sample material and reweigh:
Record data and time of cycle from which
sample was taken with the weights of the empty
and full containers. Dry samples for a minimum
of 24 hours at 75°C in a drying oven. Weigh
samples and record weight. Compute percentage
moisture content as the difference between wet
and dry weights. Average the percentage mois-
ture for all the samples from one day. Record
the computed moisture content for comparison
with other samples.
190
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APPENDIX D
TEST PLAN FOR CHARACTERIZATION OF THE
WEEKLY LOAD PROFILE FOR THE PNEUMATIC
TRASH COLLECTION SYSTEM
SCOPE
This procedure was used to characterize the weekly
load profile of solid waste transported by the pneumatic
trash collection system at the Operation Breakthrough
site in Jersey City, New Jersey. The test period was
conducted over a one week period from September 26 to
October 3, 1975. The test recorded the weight of refuse
conveyed by the PTC system for every cycle. Observa-
tion of the daily loads presented any trends in the
weekly profile to assist in eliminating nonessential
collection cycles to enhance system performance.
191
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PROCEDURE
1. The refuse container must be removed from
the compactor, and a plywood pen must be
constructed in place of the container. The
pen would detain the refuse for each cycle
until the refuse could be weighed.
2. There should be a supply of plastic bags
and a 30-gallon trash can to place the refuse
into for weighing on a scale. The refuse
for each cycle would be placed into bags and
weighed. The weights for each cycle are
recorded.
3. The scale has an adjustable pointer so that
the empty trash can may be placed on the
scale, and the adjusted pointer could be
zeroed. Thus, the weight for the refuse is
read directly from the scale by the adjustable
pointer.
4. The adjustable pointer should be checked
periodically to ascertain that it is zeroed
when an empty trash can is weighed.
5. The refuse samples are disposed into the
refuse container after weighing.
6. At the end of each test period, the plywood
pen is dismantled and the refuse container is
reconnected to the compactor.
192
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APPENDIX E
TEST PLAN FOR DETERMINATION OF
THE LOAD CAPACITY FOR THE
PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
The following procedure was performed to determine
the transport velocities of refuse samples for the load
capacity test. The test was conducted on June 9 and
10, 1975 and on December 2, 1975. The density and the
transport velocities of refuse samples resembling
typical residential and bulky solid waste were mea-
sured. The transport velocities of refuse samples for
typical residential solid waste were compared to design
estimates. The transport velocities of bulk waste were
measured so that a comparison could be made with the
design specifications. These specifications state that
the PTC system must collect refuse with densities rang-
ing to 50 pounds per cubic foot.
193
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PROCEDURE
Test loads were put into the system via the
chute at discharge valve DV-3. Discharge
valve DV-3 is located in the small shed south
of the Shelley A building. The location was
selected since it was the only location where
tenants could easily be prevented from throwing
refuse in on top of the test loads during the
procedure.
Before the tests, steady state air velocities
at the filter and at air inlet VB-B (located
at Shelley A South adjacent to DV-3) were
measured. Air inlet valve VB-B was opened
and exhauster #2 was turned on manually from
the central control panel. This configuration
was used for all load tests. The air velocity
at both the filter and VB-B was 50 mph.
The velocity at which a test load was trans-
ported through the system was measured by
observing as it entered the transport pipe at
DV 3 and emerged from the transport pipe upon
entering the cyclone at the same .time. One
stopwatch was held by the observer at DV-3.
The other stopwatch was held by the observer
at the hopper. A test load was put into the
chute. Discharge valve DV-3 was opened
manually be the control panel next to it.
When the test load entered the system, the
observer at DV-3 stopped his stopwatch. When
the observer at the hopper saw the test load
come into the hopper, he stopped his stop-
watch. Elapsed time for transport the system
was the difference of the times indicated by
the two stopwatches. After each test load,
the observers resynchronized their stopwatches
to zero by a countdown procedure over walkie
talkies. The length of the transport pipe
from DV-3 to the hopper was measured from
drawing 8881F of system blueprints furnished
by Envirogenics and it was 660 feet. Velocity
of transport was determined by dividing 660
feet by the elasped time. Some times and
velocities are indicated as ranges for those
cases which the entire load did not arrive at
one time. There was an interval of a few
seconds for the loose materials during which
the load emptied into the hopper.
194
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APPENDIX F
TEST PLAN FOR DETERMINATION OF THE
POWER CONSUMPTION FOR THE MAIN EXHAUSTERS
FOR THE PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
The following procedure was conducted to determine
the electricity used by a main exhauster during a
typical cycle. The test was performed on September 3
and repeated on December 15, 1975. Each test comprised
recording the elapsed operating time and instantaneous
power of each exhauster for three test runs. The elec-
tricity required for an exhauster is the product of the
elapsed operating time times the average value of
instantaneous power-
195
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PROCEDURE
1. The 2 rpm test motor was installed in
recorder 7. A new roll of strip chart paper
was placed in this recorder. The green pen,
which records the turbblower power signal,
was put in this recorder. The other two pens
were removed.
2. The PTC system was placed in the automatic
mode. Whenever the manual start buttom was
depressed, a complete automatic cycle was
made. During each trial, times were recorded
as soon as the green pen showed that an
exhauster was running, and at the end, when
the green pen dropped to within two percent
of the range. The difference between these
times is the elapsed time for that trial. The
exhauster number was also recorded. There
were no malfunctions or skipped steps through
out the entire test.
3. The strip chart was removed from the recorder
for analysis. The original 1/180 rpm motor
was re-installed in the recorder, as well as
the regular recorder strip chart and pens.
4. Values were summed whenever the power signal
crossed a vertical line. The average scale
reading, its standard deviation, and number
of data points were reported. This process
was repeated for each new trial.
5. The raw data were used for calculating the
elapsed time, average power, and energy con-
sumed. The average power was calculated by
multiplying the average scale reading by
1.60. This is a conversion factor for this
signal and its units are kilowatts (kw). «The
average power is also reported in units of
horsepower (hp). The conversion factor, kw
= 1.34102 horsepower was used. The energy
used is reported in units of kilowatt hours
(kwh), and is found by:
Power (kw) x Elapsed Time (min) x ,.]. . = kwh
6. Average values for elapsed time, power, and en-
ergy consumed for each exhauster were reported.
196
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APPENDIX G
TEST PLAN FOR DETERMINATION OF AN
OPTIMUM SCHEDULE FOR THE PNEUMATIC
TRASH COLLECTION SYSTEM
SCOPE
The optimal scheduling test determined the fewest
number of automatic daily cycles which provide for a
reasonably high level of collection service. During
the load capacity test, it was noticed that the load
for many cycles were lower than fifty pounds. The
optimal scheduling test observed the performance of
the PTC system with a reduced number of daily cycles
that eliminated many superfluous cycles.
197
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PROCEDURE
The PTC system was studied to identify those
components which placed a limiting factor on
the size for a cycle load. These components
were the collection hopper, the compactor,
and the storage sections for the vertical
trash chutes.
Each identified component was examined to
determine the load that it could adequately
handle, and the minimum load was determined
to be the ultimate cycle load.
a) Collection hoppei—The hopper has a
limited volume for refuse, but it was
apparent that this volume exceeded the
volume of refuse which could be safely
handled by the compactor. Therefore,
the analysis for the collection hopper
was not continued.
b) Compactoi—The compactor; which operated
on a three-stroke cycle, has a chamber
with a volume of 36.75 cubic feet. The
capacity of the compactor was computed
to be three times the chamber volume or
about 110 cubic feet.
c) Vertical trash chutes--The analysis of
the vertical trash chutes considered the
maximum volume of refuse for a single
trash chute, and the maximum volume of
refuse for all the trash chutes, since
the loads for each trash chute were not
equivalent. Each trash chute has a
limited capacity. Once this capacity is
surpassed, a chute blockage will prob-
ably occur. Blockages generally do no*t
occur unless the accumulation is higher
than the first floor. The estimated
volume of the chute to the first floor
is one cubic yard. Thus, one cubic yard
could be allowed to accumulate in a
chute before it would be necessary to
cycle the system. The chute in which
refuse would accumulate most rapidly
would be the chute in the building with
the greatest number of dwelling units
198
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occupied. Site occupancy figures were
obtained from the site management office.
There were 472 units occupied on the
site. The building with the greatest
occupancy is Shelley A with 150 rented
units. Assuming each dwelling unit gen-
erated the same amount of refuse, Shelley
A dwelling units generated 150/472 =
.318 of the total site refuse. If the
one cubic yard of refuse were allowed
to accumulate before a cycle at Shelley
A, which is .318 of the total refuse,
then about three cubic yards (81 cubic
feet) could be collected on one cycle.
d) System capacity--The capacity of the
system was found to be limited to the
volume of the storage chutes. The
maximum volume of refuse which may be
safely collected is about eighty cubic
feet.
Feasible operating schedules were selected
based on the results of the daily load pro-
file test and the maximum volume of refuse
(see Section V). The peaks in the daily load
profiles were considered as possible cycling
times. The daily number of cycles were
selected from four to twenty-four cycles.
Each operating schedule was tested for
several days to observe the performance of
the PTC system. All the vertical trash
chutes were inspected before each test to
insure that there were no chute blockages
existing before the test. Any undetected
chute blockage would unfavorably biased the
test. These chutes were frequently inspected
each day during the test to discover any
problems.
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APPENDIX H
TEST PLAN FOR MEASUREMENT OF THE
NOISE LEVELS ATTRIBUTED TO THE
PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
The noise levels associated with the collection
activities of the PTC system and the ambient noise
levels were compared. Furthermore, the noise levels
for the PTC system were compared to OSHA regulations.
This test determined whether there are excessive noise
levels attributed to the PTC system and if these noise
levels surpass industrial standards. This test was
conducted on March 24 and 25, 1976.
200
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PROCEDURE
1. All noise measurements were made with a
General Radio Co. Type 1565-B Permissible
Sound Level Meter. This meter was calibrated
twice daily by a General Radio Co. Type
1562-A Sound-Level Calibrator.
2 . The following discharge valve rooms and
adjacent public areas were measured for noise
levels during and between system operations:
a) Shelley A South
b) Shelley A
c) Shelley B East
d) Shelley B West
e) Descon Concordia
f) Camci
g) Descon Decks
h) Commercial
3. The following system components in the CEB
were measured for noise levels between and
during system operations:
a) Vent fan
b) Main exhauster
c) Compactor
d) Collection hopper
The meter was placed in general proximity
and within twelve to six inches of each
component during system operations to deter-
mine if the noise levels increased.
4. The pull-on container truck was also measured
for noise levels during its operation.
5. For each test during system operations, the
location, noise level and duration were
recorded.
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APPENDIX I
TEST PLAN FOR DETERMINATION OF THE SERVICE
LIFE FOR THE PNEUMATIC TRASH
COLLECTION SYSTEM
SCOPE
The following procedure was performed to measure
the amount of wear that was experienced by the PTC sys-
tem components during the 18-month monitoring period.
These data were used for the analysis of service life
for the PTC system. This test was conducted before
and after the monitoring period. The following compon-
ents were closely examined for wear data:
• Main transport line,
• Compactor,
• Discharge valves, and
t Collection hopper.
202
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PROCEDURE
A separate procedure is presented for each component.
MAIN TRANSPORT LINE
1. The test sections were initially characterized
by documented and certified reports stating
identification, heat, chemical analysis, and
hardness.
2. The flanges of the test sections were marked
at each end either "front" or "rear" for the
upstream and downstream ends at the pipe seam
weld. Angular positions along the circum-
ference were indexed from this weld (0°) in
a clockwise direction when facing the upstream
end. Each flange was marked by stamping the
metal.
3. Thickness measurements were taken on the pipe
sections using a Branson Caliper capable of +
0.005 inch accuracy in the following steps:
a) Mark out a surface grid on each pipe
having six inch longitudinal and 15°
radial spacings. Identify the longi-
tudinal spacing alphabetically from
front to back and the radial spacings
numerically clockwise from 0° (the
seam weld). In this manner, all points
will be referenced from the junction
of the seam weld and the front flange
(point A-l ) .
b) Prepare a data record sheet using the
grid format for each pipe.
c) Calibrate the thickness measurement
instrument against standard test sections
in accordance with the manufacturers
recommendations.
d) Measure and record the pipe thickness at
every grid point. These points were cleaned
with a wire brush, rinsed with water and
detergent, and prepared for measuring by
placing a small amount of hair cream on the
203
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point. The hair cream provided a good
medium between the test section and the
probe for the Branson Caliper so that
accurate readings could be made.
Sixteen surface impressions were made of
interior surfaces at each end of both test
sections at 90 degree rotations. Each
impression was two inches from the flange and
was made by either epoxy or auto body repair
compound. The surface was cleaned with a
brush, rinsed with water and detergent and
prepared by spraying the area with a light
layer of furniture polish. The polish
allowed the surface replica to be easily
removed-.
The test sections were weighed on a scale.
Steps 3 to 5 were performed during the
initial and final characterization periods.
The places for these readings were carefully
located and recorded so that both test
periods were examining identical areas.
COMPACTOR
1. The compactor was investigated during the
final characterization period. The unit was
visually inspected for wear and unusual con-
ditions were photographed.
2. Surface impressions were made of the com-
pactor ram face, top and other areas. The
procedure was previously presented.
3. The top of the compactor ram was measured for
thickness by the Branson Caliper. The array
of points was a straight line four inches
from the front of the compactor ram and *
parallel to it. The first reading was three
inches from the edge. The other readings
were spaced at two-inch intervals. Four
additional readings were made at the end of
the compactor ram top. These four readings
determine the original thickness of the ram.
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DISCHARGE VALVES
1. The discharge valves were visually inspected
for wear during the final characterization
period. Unusual conditions were photographed.
The teflon wearing surface was investigated
for missing, loose or chipped sections.
Additionally, surface impressions were made
of the teflon surfaces.
2. The discharge valve plates were observed for
wear. Surface impressions were made of the
following plates located at:
a) Shelley A,
b) Shelley B East,
c) Descon Concordia,
d) Camci, and
e) An extra one for initial plate conditions.
These discharge valve plates were measured
for plate thickness across two perpendicular
axes. One axis was in the direction of
travel. The thickness readings started at
three inches from the edge and spaced at two-
inch intervals.
COLLECTION HOPPER
1. The inside surface of the collection hopper was
visually inspected for wear during the final
characterization period. Any unusual conditions
were photographed.
2. The thickness of the collection hopper was
measured directly downstream of the entry
point since refuse initially impinged on this
area. An array of readings was established
at six-inch intervals horizontally and at
four-inch intervals vertically.
OTHER COMPONENTS
1. The container handling system was visually
inspected for wear during the final charac-
terization period. The following components
were particulary investigated:
a) Power and free motion rollers,
b) Drive motor, chains and sprockets for
the free motion rollers, and
205
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c) Drive motor* chains and sprockets for
the hydraulic lift trolleys.
Each chute charging station was inspected
during the final characterization period.
They were examined for proper operation,
missing or broken parts, and other unusual
conditions.
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APPENDIX J
CALCULATIONS FOR THE REGRESSION LINE
FOR THE RELATIONSHIP BETWEEN TRANSPORT
VELjOCITY AND DENSITY
SCOPE
The following analysis was performed to generate
a regression line between transport velocity and density
The results from the load capacity test were used in
this analysis. It was assumed that there was a linear
relationship between these two factors. The transport
velocity for refuse of a density of 50 pounds per cubic
foot was computed from this relationship, since the
PTC system was designed to collect refuse up to 50
pounds per cubic foot.
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ANALYSIS
The basic equation for a regression line for an
independent variable (X) and a dependent variable (Y)
i s :
Y = bx + (Y - b X")
where: Y = —-
, £XY - n
b =
- (£X)2
The data for this analysis were reported from the
load capacity test, and are presented below:
Test Load Density lb/ft3 Velocity ft/sec
Description (X) (Y)
Balsa Wood 8 52.8
White Pine 23 39.1
Fir 30 42.0
Walnut 39 24.4
Maple 47 28.7
Bundled Newspaper (Dry) 25 42.3 Avg.
Velocity
Bundled Newspaper (Wet) 46 31.6 Avg.
Velocity
Wet Rags 43 36.9
The following quantities are required to determine
the equation for the regression line.
= 261 £Y = 297.8 n = 8
£X2= 9813 TXY = 8980.0
"X = 32.63 Y =. 37.23
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The numerical value for the parameter b is:
(261 )(297.8)
__8
9813 -(^-2j
, _ 8980.0 - _ 8 rt _,_n
b = - 7 - sv- = -0.5669
The equation for the transport velocity Y of refuse
varying in density (X) is:
Y = 0.5669 X + [37.23 - (-0.5669)(32.63)]
Y = 55.7 - 0.57 X
where: X is the density of refuse in
Ibs per cu ft
Y is the transport velocity of
refuse in ft per sec
The PTC system is designed and constructed to
successfully collect refuse of a density of 50 Ibs per
cu ft. The estimated transport velocity would be:
Y = 55.7 - 0.57 (50)
Y = 27.2 ft/sec
209
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'APPENDIX K
CALCULATIONS OF THE SERVICE LIFE
FOR THE MAIN TRANSPORT LINE
SCOPE
The service life for the main transport line was
estimated by a preliminary life cycle analysis. The
wear data for the two test sections of the main trans-
port line were used. It was assumed that the wear
rate is a constant. The estimated service life, as
computed in this analysis, is compared to the 40-year
service life requirement in the design specifications,
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ANALYSIS
The main transport line was designed and construc-
ted to perform for forty years. The two test sections
were examined for wear to determine the service life
for the entire line. The line, which is placed under a
partial vacuum, is constantly eroded by the passing of
solid waste. To prevent the collapse of the line, a
minimum wall thickness must be maintained. This
analysis determined the value for the minimum wall
thickness for the service life estimate. The basic
equation for the service life of the main transport
line is:
w
where: L is the service life in years
t is the original wall thickness in inches
t is the minimum wall thickness in inches
w is the annual wear rate in inches per
year
The minimum allowable wall thickness is determined
by the geometry of the main transport line, and by the
maximum vacuum level experienced by the line. The
maximum vacuum level is at the end of every automatic
mode cycle to seal the discharge valve lids onto the
valve bases and is about 75 inches H20 or 2.70 psi vacuum.
The following expressions are also required and are
based on the geometry:
D0 = outside diameter and is 20 inches.
L = distance between main transport line
stiffeners and is 8 feet.
The minimum wall thickness value is determined by
an interative process. A minimum wall thickness value
(tm) is assumed and a parameter [B = P(Dq/tm)] is deter-
mined (Ref. 26). After B is found and since Dp and tm are
also known, the calculated value for P is checked with
the given value of 2.70 psi. Then, the value of tm is
modified so that the pressure is equal to 2.70 psi.
This final value of t is the minimum wall thickness
value. m
211
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APPENDIX L
CALCULATIONS OF THE SERVICE LIFE
FOR THE DISCHARGE VALVES
SCOPE
Preliminary life cycle analyses were conducted to
determine the service life of the discharge valves for
the PTC system. These analyses were based on data for
the wear of the discharge valve plates. The wear rate
for these plates was assumed to be constant. The ser-
vice life for the discharge valves were compared to the
40-year service life required in the design specifica-
tions.
212
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ANALYSIS
The discharge valves were designed to operate for at
least for forty years. The discharge valve plates
experienced the greatest amount of wear and are identi-
fied as critical components. The plates for the dis-
charge valves at Shelley, Descon Concordia, and Camci
were measured for thickness by an ultrasonic device. A
final discharge valve, located in the CEB, for the
Commercial building was uninstalled, and used for a
control case. The readings for all the values are
reported in Table 49.
The thickness readings for the control case ranged
from 0.638 to 0.630 inch. The mean value of the dis-
charge valve plate is 0.633 inch and is 0.005 inch less
than the maximum value.
The following procedure was established to deter-
mine the service life of each discharge valve plates.
The largest value for for each case is considered to be
the maximum thickness of the original value surface.
The average value of the original value surface is
assumed to be 0.005 inch less. The wear incurred in
service for one year is assumed to be two-thirds the
difference between the average value and the smallest
reading since the PTC system operated for eighteen
months. The minimum allowable thickness for the value
plate was assumed to be identical to the value for the
main transport line, or 0.070 inch. The following
equation was used to compute the service life:
L =
w
where L is the service life in years.
t is the original plate thickness
in inches.
t is the minimum plate thickness
171 in inches.
w is the annual wear rate in inches
per year.
213
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Table 49. THICKNESS READINGS^FOR THE
DISCHARGE VALVE PLATES'
Shell
0.635
0.632
0.632
0.633
0.634
0.635
0.630
0.629
0.626
0.624
0.625
0.622
0.623
0.627
1 ey
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
A
628
628
628
625
626
630
628
624
624
625
625
626
627
626
629
Descon
Concordia
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
6
6
6
6
38
32
31
30
627
625
623
6
39
628
6
6
32
26
628
6
29
629
6
30
Control
Camci Case
0.643 0.
0.652 0.
0.641 0.
0.639 0.
0.636 0.
0.637 0.
0.644 0.
0.632 0.
0.641 0.
0.647 0.
0.
0.
0.
0.
0.
0.
632
6
31
636
6
32
631
6
6
6
6
30
33
38
35
631
6
37
631
6
6
6
6'
34
36
34
31
1
Readings are in inches.
214
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The results for this test are presented in Table 50
Table 50. RESULTS FOR SERVICE LIFE
CALCULATIONS FOR THE DISCHARGE VALVE PLATES
Descon
Shel1ey A Concordia Camci
Largest thick- 0.635 0.639 0.652
ness (in.)
Average origi- 0.630 0.634 0.647
nal th ickness
(in.)
Smallest 0.622 0.623 0.632
thickness (in.)
Annual wear 0.0053 0.0073 0.010
rate (in. per
year)
Service life 106 77 58
(years )
215
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APPENDIX M
CALCULATIONS OF THE ENERGY USAGE
FOR THE PNEUMATIC TRASH COLLECTION SYSTEM
SCOPE
The annual electricity consumption for the PTC
system was computed. The components which used the
most electricity were identified. In every case,
except for the main exhausters, manufacturers data and
operating time were recorded to determine the power
consumption. The main exhausters were independently
tested for power usage.
216
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ANALYSIS
The annual energy usage for the PTC system was
determined by calculating the total electrical demand
for all of the system components. The following com-
ponents were identified as the largest users of elec-
tricity:
• Main exhausters,
• Compactor, and
• Vent fan.
The main exhausters operated 6952 cycles annually,
and used an average energy amount of 9.04 kwh per cycle.
The energy consumption for each main exhauster was mea-
sured in the main exhauster power tests. The elec-
tricity used by the exhausters is 62,846 kwh per year
and is calculated by:
6,952 cycles/yr x 9.04 kwh/cycle = 62,846 kwh/yr
The compactor, which is operated hydraulica1ly, has
a 10 hp induction motor with a service factor of 1.15.
The elapsed time for the compaction stage during each
automatic cycle is 2.5 minutes per cycle. The annual
electricity used by the compactor for 6952 cycles is
2484 kwh per year, and is determined by:
10 hp x 1.15 x
= 2484 kwh
1 kw
1341 hp
x 2.5 min x
1 hr
60 min
x 6952 cycles/yr
a 2 hp induction
The total annual
the total time in a
and the total down-
The yent fen, which removed odors from the verti-
cal gravity chutes in the residential buildings, oper-
ated between system operations except whenever there
were system malfunctions (that were not related to com-
pactor failures). The vent fan has
motor with a service factor of 1.15
operating time for the vent fan was
year minus the total cycling times
time (which were unrelated to compactor malfunctions).
The total operating time for the vent fan was 4215 hours
and was computed by:
Total time per year - total annual cycle time -
[total downtime - compactor downtime]
= total operating time for the vent fan
217
-------
8760 hr - 879 hr - [4144 hr - 478 hr]
4215 hr/yr
The energy consumed by the vent fan was 7229 kwh
per year and was found by:
1 If W
4215 hr/yr x 2 hp x 1.15 x 1 34] hp - 7229 kwh/yr
Additional components for the PTC system were elec-
trically operated. Some of these components are the pro-
grammer, the annunciator panel, the central control panel
and additional equipment. It was assumed that the addi-
tional energy requirements was one-tenth of the energy
usage of the main exhausters, compactor and vent fan.
The total amount of electrical energy usage was
72,559 kwh per year. The energy requirements of the
major system components are presented in Table 51.
Table 51. ANNUAL ELECTRICAL ENERGY
USAGE FOR THE PTC SYSTEM
System Component Annual Energy Usage
Main Exhausters 62,846 kwh/yr
Compactor 2,484
Vent Fan 7,229
Other System Components 7 ,256
72,559 kwh/yr
218
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APPENDIX N
CALCULATIONS OF THE COST PROJECTIONS
FOR THE PNEUMATIC TRASH COLLECTION SYSTEM
AND THREE CONVENTIONAL ALTERNATIVE SYSTEMS
SCOPE
The annual costs for the PTC system and the three
alternative conventional systems were projected for the
following years; 1975, 1980, 1985, 1990, and 1995. The
annual collection costs were computed by multiplying
labor, material and electrical costs by cost indices
which were generated for these from a previous study.
These indices are presented in Table 52. The adjusted
costs for labor, material and electrical costs were
added to the annualized capital costs to determine the
projected annual costs. The results for the PTC and
three conventional solid waste management systems are
presented in Tables 53, 54, 55, and 56 respectively.
219
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Table 52. PROJECTED COST INDICES FOR LABOR,
MATERIAL, AND ELECTRICAL COSTS
Costs 1974 1975 1980 1985 1990 1995
Labor 100.00 105.10 139.02 182.49 238.18 309.53
Material 100.00 102.55 116.29 131.87 149-54 169.58
Electri-
cal1 100.00 105.82 140.29 187.75 251.26 336.25
The cost indices for electricity are based on the
costs for No. 2 Diesel fuel oil, since the electricity
is produced at the site from five generators.
Table 53. PROJECTED ANNUAL COSTS FOR THE PTC SYSTEM
Costs 1975 1980 1985 1990 1995
Capital $89,782 $89,782 $89,782 $89,782 $89,782
Labor 26,972 35,676 46,831 61,124 79,435
Material
Electri-
cal
793
2,474
899
3,280
1 ,020
4,389
1 ,156
5,874
1 ,311
7,861
TOTAL $120,021 $129,637 $142,022 $157,936 $178,389
220
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Table 54. PROJECTED ANNUAL COSTS FOR
CONVENTIONAL REFUSE COLLECTION SYSTEM A
Costs
Capital
Labor
Material
TOTAL
Costs
Capital
Labor
Material
TOTAL
Costs
Capital
Labor
Material
TOTAL
1975
$ 5,408
26,218
207
$31,833
Table 55.
CONVENTIONAL
1975
$ 5,408
20,616
207
$26,231
Table 56.
CONVENTIONAL
1975
$ 3,354
71,206
40
$74,699
1980
$ 5,408
34,679
274
$40,361
PROJECTE
REFUSE
1980
$ 5,408
27,269
274
$32,951
PROJECTE
REFUSE
1980
$ 3,453
94,184
45
$97,682
1985
$ 5,408
45,522
367
$ 51,297
1990
$ 5,408
59,415
492
$ 65,315
1995
$ 5,408
77,215
658
$ 83,281
D ANNUAL COSTS FOR
SYSTEM COLLECTION B
1985
$ 5,408
35,796
367
$ 41,571
1990
$ 5,408
46,720
492
$ 52,620
1995
$ 5,408
60,716
658
$ 66,782
D ANNUAL COSTS FOR
COLLECTION SYSTEM C
1985
$ 3,453
123,635
51
$127,139
1990
$ 3,453
161,367
58
$164,878
1995
$ 3,453
209,709
66
$213,228
221
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-017
3. RECIPIENT'S ACCESSION1 NO.
4. TITLE AND SUBTITLE
EVALUATION OF THE REFUSE MANAGEMENT SYSTEM AT THE
JERSEY CITY OPERATION BREAKTHROUGH SITE
5. REPORT DATE
February 1978 (Issuing Datej
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Jack Preston Overman and Terry G. Statt
8. PERFORMING ORGANIZATIC
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Hittman Associates, Inc.
9190 Red Branch Road
Columbia, Maryland 21045
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
68-03-0094
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Cin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Robert A. Olexsey (513) 684-4363
16. ABSTRACT
This study evaluates the solid waste management system at the Jersey City
Operation Breakthrough site and assesses the economic and technical practicality
of the system application for future residential complexes. The installation was
the first pneumatic trash collection system (PTC) used to collect residential
refuse in the U.S. This report describes labor costs, rodents and vermin, odor,
litter, and collection noise. The report also compares cost and operation of the
PTC system with those aspects of conventional collection systems.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
:. COS AT I Field/Group
Refuse, Collection, Housing,
Housing Projects
Solid Waste Collection
High Rise Building
Residential Complexes
13B
3. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
UNCLASSIFTF.n
21. NO. OF PAGES
140
20. SECURITY CLASS (This page)
22. PRICE
EPA Form 2220-1 (9-73)
222
* U.S. GOVERNMENT PRINTING OFFICE: 1978- 260-880:25
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