&EPA
United States
Environmental Protection
Agency
Water Engineering
Research Laboratory
Cincinnati OH 45268
Office of Municipal
Pollution Control
Washington DC 20460
Research and Development
EPA/600/M-86/011
May 1 986
Design Information
Report
Belt Filter Presses
The U. S. Environmental Protection Agency has undertaken a program to help municipalities and engineers
avoid problems in wastewater treatment facility design and operation. A series of Design Information
Reports is being produced that identifies frequently occurring process design and operational problems
and describes remedial measures and design approaches which may be used to solve these problems. The
intent is not to establish new design practices, but to concisely document improved design and operational
procedures that have been developed from field experiences.
With an increased emphasis being placed on the problems of disposal of sludges from wastewater
treatment facilities, there has been a growing awareness of the need for improved efficiency and reliability
in the performance ofin-plant sludge treatment processes. The dewatering of sludges is an important step
in the total sludge processing train, and can have a serious impact on the effectiveness and cost of
subsequent sludge treatment and disposal processes. The use of belt press filtration for sludge dewatering
has increased in recent years, and belt presses are a frequently considered alternative when upgrading an
existing facility or planning a new facility.
Introduction
This report discusses current problems associated
with selection, design, and operation of belt filter
press dewatering systems at municipal wastewater
treatment facilities. The report discusses application
of the press itself, as well as selection and application
of auxiliary equipment associated with the belt filter
press. Critical to the success of a belt filter press
dewatering system is (1) an examination of equipment
selection, control, and arrangement from an opera-
tional viewpoint; (2) consideration of safety, conven-
ience of control, and accessibility; and (3) assurance
of equipment durability.
Belt filter presses have been in use in the United
States for approximately 15 years. The devices were
developed from technology associated with the
manufacture of paper, and have had a number of
problems in being transferred to municipal sludge
applications. Early belt press models demonstrated
poor performance and durability when compared to
vacuum filters and centrifuges, often requiring large
dosages of conditioning chemicals and producing a
poorly dewatered sludge cake. Most of these early
problems have been eliminated. Although durability
and lack of integrated controls can still be a problem,
this is becoming less frequent as engineers specify
higher quality equipment.
Equipment Description
Belt filter presses are continuous sludge dewatering
devices which use chemical conditioning, gravity
drainage and mechanically-applied pressure to de-
water sludge. A simplified schematic of this device is
presented in Figure I.
In most belt presses, conditioned sludge is first
introduced to the gravity drainage section where
thickening takes place through the drainage of free
water. Suspended solids concentration of the sludge
normally increases by a factor of three in this section.
On some devices this section is provided with a
vacuum assist which enhances drainage, and may
help to reduce odors. Following gravity drainage, the
sludge is subjected to gradually increasing pressure
by squeezing between opposing cloth belts. The belts
are held in place by a series of rollers that subject the
sludge to shearing forces as the belts pass through a
series of off-set rollers with reducing diameters that
define a serpentine path. The squeezing and shearing
forces thus introduced release additional quantities
of water from the sludge.
Belt filter presses may be utilized to dewater nearly all
types of sludges generated at municipal wastewater
treatment plants. The major exceptions are sludges
that are primarily chemical in nature, and biological
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Figure 1. The Three Basic Stages of a Belt Filter Press
Stage 1
Chemical
Conditioning
Polymer
Solution
Stage 2
Gravity
Drainage
Stage 3
Shear &
Compression
Dewatering
Wash Spray
Mixer, in Line Injection
or Conditioning Tank
Filtrate & Spent
Washwater
Doctor
Blade
sludges that have been conditioned or stabilized with
lime. Typical performance data for belt filter presses
on various types of sludge are shown in Table I. The
data are generally representative of the performance
of available equipment, although loading rates and
cake solids contents in the upper end of the ranges
shown are not normally achieved.
In most cases, the sludge cake produced on belt
presses has sufficiently high solids content to allow
all types of disposal methods, including direct incin-
eration. Because it is polymer conditioned, belt press
cake has a higher volatile solids proportion than other
sludge cakes, making it more amenable to incinera-
tion or composting than a sludge cake of the same
solids concentration conditioned with lime and ferric
chloride .
An interrelated system of auxiliary components
supports the operation of the belt filter press. This
auxiliary equipment includes:
1. Sludge Feed Pumps: These are continuously-
operating, adjustable flow rate pumps, usually
of progressive cavity design used to feed sludge
to the belt press.
2. Polymer Mixing and Feeding System: Because
polymer is required for sludge conditioning (see
Table 1), a bulk polymer processing system is
normally required to prepare and meter polymer
to the feed sludge.
3. Washwater System: High pressure (410 kPa [60
psi] and greater) washwater is required to clean
the dewatering belts after cake discharge.
4. Tension/Tracking Motive System: Either a
pneumatic (compressed-air) or hydraulic power
source is used to provide tension to the dewater-
ing rollers and to reposition the rollers in order
to keep the dewatering belts on track. Electrical-
ly-operated systems have also been used, but to
a much lesser extent.
5. Sludge Cake Conveying: Belt conveyors are the
most common method used for lateral convey-
ance of sludge, either to a truck (through a
receiving and storage hopper), or other receptor.
Design Considerations
There are approximately 20 manufacturers of belt
filter presses. Each manufacturer produces a press
having slightly different quality, mechanical features,
and operating characteristics. The presses are avail-
able in widths from approximately 0.5 meters to 3.5
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Table 1. Typical Dewatering Performance of Belt Filter Presses*
Type of Sludge
Raw Primary (P)
Waste Activated (WAS)
P + WAS
P + Trickling Filter (TF)
Anaerobically Digested
P
WAS
P + WAS
Aerobically Digested
P + WAS
P + WAS (thickened)
Oxygen Activated WAS
Thermally Conditioned
P + WAS
Feed Solids
Concentration
<%)
3-10
0.5-4
3-6
3-6
3-10
3-4
3-9
1-3
4-8
1-3
4-8
Dry Solids Loading Rate
kg/hr/Meter Belt Width
(Ib/hr/Meter Belt Width)
360-680
40-230
180-590
180-590
360-590
40-136
1 80-680
90-230
40-230
90-180
290-910
(800-1500)
(100-500)
(400-1300)
(400-1300)
(800-1300)
(100-300)
(400-1500)
(200-500)
(300-500)
(200-400)
(600-2000)
Dry Polymer Utilization
mg/kg
(Ib/ton)
1,000-5,000
1,000-10,000
1,000-10,000
2,000-8,000
1,000-5,000
2,000-10,000
2,000-8,000
2,000-8,000
2,000-8,000
4,000-10,000
-0-
(2-9)
(2-20)
(2-20)
(3-15)
(2-10)
(4-20)
(3-15)
(4-15)
(4-15)
(8-20)
(-0-)
Cake Solids
(%)
28-44
20-35
20-35
20-40
25-36
12-22
18-44
12-20
12-30
15-23
25-50
'Summary of data provided in references 2, 7, and 8
meters, with over 80 percent of municipal presses
having either one or two meter belt widths.
The major components of the belt filter press are its
frame, belts, rollers and bearings, belt tracking and
tensioning systems, and its controls and drives. Other
components include a flocculation system, cake
discharge blades, and cake monitoring devices.
Various types and shapes of materials can be used in
frame construction. Generally, welded or bolted
structural steel that has been coated to resist
corrosion is utilized. Bolted frames must be securely
fastened with locking-type hardware to assure dura-
bility.
Belts are made of woven synthetic fibers, generally
monofilament polyester such as rayon. Nylon belts
are available, but are normally used for specific
applications such as high pH sludges or abrasive
slurries. Various material and weave combinations
are available from belt suppliers. Either seamed or
seamless belts are available. Seamed belts include
stainless steel clipper-type seams, or zipper-types.
Seamed belts tend to wear quickly at the seam due to
a high degree of discontinuity at that point, and
resultant wear at rollers and the doctor blade. Zipper-
type seams provide less discontinuity than clipper
seams and have a longer life. Seamless belts are
continuously woven endless belts that have a longer
service life than any other belt-type. However,
seamless belts are more costly than other belt types,
and only one manufacturer markets a belt press that
lends itself to the use of a seamless belt.
Rollers and bearings are the mechanical heart of the
belt filter press. Rollers provide the pressure and
shear in the compression zone of the press, and
assure proper belt support and tension. They are
available in a variety of materials, including stainless
steel and rubber coated steel. Perforated rollers
(normally stainless steel) are used in initial pressure
stages by some manufacturers to enhance drainage.
The rollers are supported on and guided through
bearings, normally the pillow-block type. Because
they are used in a strenuous environment, highly
durable, well sealed bearings are required.
Belt tracking and tensioning systems utilize electro-
mechanical sensors to determine the position and
force applied to the press belts. They act through the
press instrumentation system to hydraulically, pneu-
matically or electronically realign and adjust belt
position and tension. Continuously acting, rather
than on-off devices, provide the least stress on the
belt and machinery.
Belt press controls include the instrumentation
necessary to maintain press operation. They are
provided in accordance with the needs of each facility
and at a minimum contain starting and stopping
devices for the press and its auxiliaries, the instru-
mentation for the belt tensioning and tracking system,
and any required safety interlocks. The main belt
drive is an electric motor, as are the drives for
auxiliaries such as the flocculation system and the
belt washing system. Integrated, centralized controls
for the dewatering system are recommended.
Most belt presses come equipped with an integral
sludge flocculation system. However, this system can
be varied by the user, and separate flocculation
devices can be specified. The devices are normally a
flocculation tank mixing drum, or in-line chemical
mixers such as static-tubes.
Cake discharge is accomplished over a discharge
roller and assisted by a discharge, or doctor, blade.
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The position and pressure of the doctor blade against
the belt press discharge roller is adjustable. The cake
discharge can be monitored for weight and thickness
using a number of electro-mechanical devices, none
of which have been shown to be of great value.
Most manufacturers will provide estimated perform-
ance data and sizing criteria for belt presses if given
the specifics of the sludge to be dewatered. Per-
formance claims should be carefully reviewed and,
where possible, confirmed through pilot testing.
Specifications should contain requirements for per-
formance bonds.
In terms of integration within the overall treatment
process, belt filter press performance varies directly
with the feed sludge solids concentrations (see Table
1). The performance of belt presses decreases when
they are used to dewater digested sludges, particular-
ly those associated with aerobic digestion of waste
activated sludge. As with other dewatering opera-
tions, it has been found that the overall performance
of the belt press can be improved if fluctuations in
conditioning, percent solids, type of sludge, and
sludge constituents are minimized.
Problem Areas and Potential Solutions
The major problems encountered with use of belt
filter presses can be categorized as follows:
• Problems associated with equipment quality.
• Problems related to operating practices.
• Problems related to process integration.
• Problems related to integration of auxiliary sys-
tems.
Table 2. Causes and Remedial Measures for Belt Tear
5.
Causes
Remedial Measures
Use of inferior quality
belt material
2. Wear at seam on stainless
steel clipper belts
Failure of belt in high
pressure zone due to
tensionmg and tracking
problem (formation of
creases in belt are
evidence of problem)
4. Misalignment of rollers
Belt shifting and/or
creasing due to:
a. Uneven feed
distribution
b. Insufficient washdown
6.
High wear due to use of
hard plastic doctor
blade
Use high quality belts
a. Replace existing belts
b. Specify high quality;
require a 4000 hr.
minimum warranty.
Use zipper seamed or
unseamed belts
a Replace existing belts
b. Specify zipper seamed or
unseamed belts.
Use improved tensioning
and tracking systems.
a. Replace tension/
tracking systems in
existing presses
b. Specify high quality
tensioning/tracking
systems for new presses
(separately discussed in
this Section)
Check and adjust roller
alignment and tensioning/
tracking system as
necessary.
Check sludge distribution
and review washdown
procedures, then:
a. Improve sludge
distribution to gravity
drainage zone of press if
possible.
b Require improved
washdown and press
maintenance.
Replace blade with a more
resilient ultra-high
molecular weight blade.
Equipment Quality Problems
The problems associated with equipment quality
primarily involve belt quality, type and reliability of
belt tensioning and tracking systems, and roller and
bearing quality. It must be noted that many of these
problems are associated with the initial installations
of belt presses and that the better equipment
manufacturers have eliminated many of these prob-
lems. Other equipment problems include frame and
instrument corrosion, inadequate safety arrange-
ments, and poor noise control.
Belt Tear—Torn belts are one of the major problems
associated with the use of belt presses. The causes
for belt tearing range from inferior quality belt
material to misalignment of the equipment to im-
proper operation and maintenance. The major causes
for belt tear and associated remedial measures are
shown in Table 2. Many of these problem areas have
been reduced or eliminated by general improvements
in belt press design, particularly belt tensioning and
tracking systems, and improved materials for the
belts themselves.
BeltTensioning/Tracking—Low quality belt tension-
ing/ tracking systems are generally associated with
poorer quality belt filter presses. Systems that utilize
exposed gearing present a safety hazard; those which
are not continuously acting will impose a jarring
action on belts. Retrofit of continuous tensioning/
tracking systems on existing equipment should be
considered, but this is generally difficult and costly.
On new facilities, specifications should require
continuously acting systems that are readily acces-
sible for easy maintenance with properly covered
gearing to minimize potential safety hazard.
Roller Failure—Roller failure can be caused by
inferior equipment, or by passage of large material
such as heavy rags on to the press. High quality,
corrosion resistant rollers constructed of epoxy
coated steel, rubber coated steel or stainless steel
should be utilized. If problems with foreign objects are
experienced, the sludge should be ground or screened
prior to dewatering.
4
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Bearing Failures—The causes and remedial meas-
ures for a high frequency of bearing failures are
presented in Table 3. In general, durable bearings
with an L-IO life (less than a 10 percent failure rate) of
100,000 hours or more should be specified.
Press Drainage—Poor drainage of belt presses
presents housekeeping and safety problems. Im-
proved press drainage pan designs and increased
attention to design of press support wells are
solutions.
Gravity Sludge Drainage—When insufficient gravity
drainage is achieved, overall dewatering performance
is diminished. Poor drainage can be a result of an
insufficient gravity drainage section, or of poor
spreading of sludge on the gravity drainage section.
Sludge spreading is improved by provision of furrow
devices that distribute sludge across the belt at the
head end of gravity drainage sections. Drainage can
be improved operationally by reducing press speed.
However, this practice will reduce press capacity.
Persistent gravity drainage problems may require the
evaluation of polymer selection, sludge conditioning,
belt material and weave suitability, and belt wash
operation.
Belt Cleaning—Belt cleaning problems are related to
improperly sized washwater systems and/or to
clogging of spray nozzles. Washwater pumps must
have sufficient pressure and flow to meet manu-
facturers' requirements. Washwater needs should be
verified during design and certified by equipment
suppliers during the shop drawing review stage,
before equipment is approved for installation. Wash-
water pumps should be furnished by the same
supplier as the belt press. Adequate access should be
provided to spray nozzles and the washwater piping
system so that they can be cleaned easily. Stainless
steel cleaning brushes within spray header systems
facilitate cleaning and should be specified. Where
plant effluent is used for washwater, strainers should
be installed in the system and provision for final
washdown and flushing with potable water should be
considered.
Personnel Safety—Personnel safety needs must be
fully considered. Adequate safety stops and trip wires
around the belt filter press and conveyors, convenient
and safe equipment access, non-slip walkways and
floors, and sufficient lighting must be provided and
properly maintained. Sound-deadening material
should be used in the walls and ceilings of dewatering
rooms to reduce noise levels.
Controls—Insufficient equipment control is a result
of an incomplete understanding of the equipment and
process. Major manufacturers of belt presses have
improved their controls by providing such features as
continuous acting belt tensioning/tracking systems
Table 3.
Causes and Remedial Measures for Frequent
Bearing Failure
Causes
Remedial Measures
1. Improper Alignment of
rollers due to:
a Poor alignment during
assembly or
maintenance
b. Structural failure of
frames.
2. Poor bearing protection
and/or improper seals
3. Poor bearing lubrication
due to:
a. Poor maintenance
practices
b. Poor bearing location
and/or poor location of
grease fittings
Properly align rollers by.
a Proper installation and
maintenance
b Use of durable frames
c. Stiffening of frame and
realignment of rollers.
2. Utilize double or triple
sealed bearings.
3. Improve lubrication
practices by.
a. Requiring ease of
lubrication on new
equipment
b Requiring proper
maintenance
procedures
c. Relocating grease
fittings and/or
extending them for ease
of maintenance on
existing equipment.
and by monitoring and alarming critical functions
such as belt misalignment, belt tension and low
washwater pressure. These functions can be inter-
connected with the press system controls such that
when activated they shut down the press and
auxiliary equipment. Other system controls for aux-
iliary equipment and chemical feed systems are the
responsibility of design engineers. These controls
should be located near the belt press, allowing
operators to control the dewatering system while
observing the equipment.
Operational Concerns
Few of the difficulties related to belt filter press
dewatering are associated with operation of the
units. The problems that have been encountered are
outlined on Table 4. As seen in the table, operating
problems can generally be corrected by providing
improved hands-on training on sludge conditioning
practices and equipment operation either initially or
as follow up during the first few years of plant
operation.
Process Application
The sludge handling system in which the belt filter
press is employed can have a significant impact on its
performance. In some cases, belt filter press per-
formance has been substantially affected by the
processes and operations preceding it; in others, belt
presses were misapplied. The difficulties associated
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Table 4. Causes and Remedial Measures for Belt Press Operational Problems
Causes
Remedial Measures
1 Improperly conditioned sludge due to:
a. Varying characteristics of raw sludge feed.
b. Improper polymer selection or dosage rate.
c Improper point of application of polymer that results in
inadequate mixing time.
2. Insufficient gravity drainage of sludge
3. Loss of sludge from between belts
4 Poor housekeeping
5 Poor safety practices, including: 5.
a. Removal of spray and other equipment guards to facilitate
observation
b. Inactivation of trip-wires to facilitate access to equipment.
Improve conditioning practices by:
a. Assuring continuity of sludge through blending of sludge
prior to dewatering. Blending facilities should be considered
where not provided.
b. Polymers should be carefully selected and tested.
Selection and dosage rate should be checked frequently,
particularly when changes in sludge characteristics are
expected.
c. The point at which polymer is applied should be reviewed and
revised as necessary to assure adequate mixing.
Evaluate:
a. press speed/drainage time
b. polymer selection and sludge conditioning system
c. belt weave and/or material selection
d. proper operation of belt wash system
Reduce belt tension.
Train operators to properly maintain the press area.
Provide steam cleaning equipment to assist cleanup.
Provide safety training and stringently enforce rules to keep
safety equipment in place.
a. Design guards for ease of removal and replacement. (One
manufacturer uses light weight panels that fasten with
magnets.)
b. Design safety equipment to minimize interference with
operation.
with poor process integration and improper applica-
tion include:
1. High pressure/tension presses are more com-
plex and require more maintenance than lower
pressure machines. When the high solids cake
produced on these devices is not needed, the
added maintenance and additional costs are not
worthwhile.
2. Increased maintenance, reduced bearing life
and increased corrosion and cloth blinding can
occur in belt presses when used to dewater
sludge conditioned with lime. Where lime
addition to the sludge is required, the lime is
most appropriately applied in mixers following
belt press dewatering.
3. Because different sludges have different condi-
tioning and press operational requirements,
wide variations in sludge characteristics can
result in poor conditioning and in reduced
dewatering efficiency. Sludge blending facilities
are needed where sludge characteristics are
likely to vary widely.
Auxiliary Systems
A number of problems associated with belt filter press
dewatering are a result of poor selection, location, or
design of the auxiliary equipment associated with the
operation. Major problems with this ancillary equip-
ment include: poor selection and location of controls,
polymer system problems, poor equipment access.
inconsistent sludge feed and lack of odor control
methods.
Controls—Problems related to selection and location
of controls include poor positioning of controls, a lack
of centralized controls, and inadequate control inter-
locks.
Controls and/or monitoring equipment are often not
provided for key process parameters such as wash-
water, sludge feed, and polymer feed rates. In
addition, sampling points are not provided for analysis
of feed sludge and filtrate. Such monitoring and
sampling equipment should be provided to allow
computation andtracking of solids capture efficiency.
The controls for the belt press and its auxiliary
equipment should be centralized. At a minimum, this
should include controls for the press, polymer feed
system, sludge feed system and sludge cake con-
veyance system. Ideally the controls should be located
in a separate room or enclosed behind a vision panel
to protect them from moisture. If the controls cannot
be isolated, the control panels should have a NEMA
type 4 rating to assure instruments will be protected
against the moist, corrosive atmosphere found in
dewatering rooms. In addition, to help avoid corrosion
problems, dried air should be used in pneumatic
controls.
When controls are located in a control room, the room
should have a separate air handling system and be
located for ease of equipment observation. Wherever
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possible, controls should be located to allow ease of
observation of the belt press gravity drainage section.
The controls for each part of the sludge dewatering
system should be interconnected to assure coordi-
nated system operation. Sludge feed, polymer feed,
belt press and sludge conveyor startup and shut down
should be properly sequenced for either automatic or
manual operation. Polymer feed should be paced on
sludge feed rate through the dewatering control
system. Automatic shutdown of dewatering equip-
ment should occur for any of the following fault
conditions:
1. Belt drive failure
2. Sludge conditioning tank failure
3. Belt misalignment
4. Insufficient belt tension
5. Loss of pneumatic or hydraulic system pressure
6. Low belt washwater pressure
7. Emergency stop (trip wire)
8. High sludge level on gravity drainage section
Polymer Feed System—Difficulties encountered
with polymer feed systems include polymer process-
ing unit malfunctions (i.e., pump and valve failures),
improperly sized feed equipment, inadequate mixing
of polymer and sludge, and an inability to pace
polymer feed rate with sludge flow. Contract speci-
fications should require proof of performance for
polymer processing units. Polymer feed equipment
should be sized to handle the broadest possible range
of both liquid and dry polymer dosage rates.
Equipment Access—Access to the belt press and its
auxiliaries is occasionally inadequate. This is often
the case where equipment is retrofitted. Adequate
platforms and/or walkways should be provided
around presses and free space should be allowed on
one side of each press for roller removal. Facilities for
lifting or hoisting heavy equipment should also be
provided. Monorail hoists or lifting hooks should be
considered. Portable A-frames are convenient for
roller removal.
Sludge Feed—Uneven sludge feed is associated with
the use of reciprocating pumps and high maintenance
is associated with the use of progressive cavity
pumps. The use of reciprocating pumps is generally
not recommended by belt press manufacturers and
should be avoided. Progressive cavity pump problems
can be reduced by removal of grit and removal or
grinding of rags prior to pumping. Removal or grinding
of rags is also recommended to reduce the potential
for roller problems. Where service conditions permit,
rotary lobe pumps can provide adequate continuous
sludge feed.
Odor Production and Control—Where septic sludge,
or sludge containing highly odorous material is
dewatered, odor release within dewatering rooms
can pose a significant problem. Dewatering rooms
should be adequately ventilated with at least six air
changes per hour. Overhead exhaust systems are
helpful in eliminating odorous gases. Where odorous
sludge is anticipated, odor control systems such as a
carbon adsorber or a wet scrubber should be investi-
gated to determine which system is more cost-
effective for the types of odors expected. Septic
sludge should be dewatered as soon as possible, and
can be "freshened" using potassium permanganate
and caustic soda.
Summary
Design of belt filter press dewatering systems requires
the coordination of several important considerations.
The performance of a belt filter press is dependent
upon various auxiliary systems that provide proper
sludge conditioning and continuity of sludge feed.
Monitoring and control systems are necessary to
identify and respond to equipment malfunctions and
changing sludge characteristics.
The following considerations and recommendations
should be included in the design and operation of belt
filter press installations:
A. Equipment
• Utilize durable materials for equipment con-
struction.
• Provide sturdily constructed, properly coated
frames.
• Utilize long life bearings (L-10 life of at least
100,000 hrs.).
• Utilize high strength rollers.
• Provide continuously acting tension/tracking
systems.
• Utilize zipper-type seamed belts or use seam-
less belts.
• Utilize durable, properly woven materials for
belts.
B. Performance
• Consult manufacturers for design and per-
formance data early in design.
• Confirm performance data with other operat-
ing installations or through pilot testing
during design.
• Specify high quality equipment and require a
performance bond.
• Assure system integration by specifying that
the dewatering system bethe responsibility of
a single supplier.
C. Auxiliary Systems
• Provide sludge blending prior to dewatering to
enhance continuity of feed sludge.
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• Either remove rags, or grind them prior to
dewatering to minimize roller problems.
• Provide flexibility in points of polymer applica-
tion and type of polymer to be used.
• Utilize continuously acting high pressure
sludge pumps such as progressive cavity or
rotary lobe pumps.
• Provide positive ventilation for odor control in
dewatering rooms. Where sludges with a high
odor potential are to be handled provide carbon
or chemical odor control systems.
D. Controls
• Provide instrumentation to monitor such
operating parameters as sludge, filtrate, and
washwater flow (with provisions for sampling).
• Integrate ancillary system controls with those
for the dewatering equipment and intercon-
nect key control functions.
• Protect controls from the moist, corrosive
operating environment.
• Locate controls within sight of belt presses,
preferably where gravity drainage sections
can be observed.
E. Safety
• Provide non-skid walkways and floors.
• Provide adequate access to equipment.
• Assure installation and maintenance of trip
wires, drive guards and other protective
equipment.
• Educate operators as to correct safety pre-
cautions and assure adherence to rules.
F. Operations
• Monitor system performance to assure opti-
mum operation.
• Assure that sludge is properly conditioned,
and that variations in feed sludge quality and
characteristics are minimized.
• Assure proper gravity drainage of sludge.
G. Operator Training
• Provide operation and maintenance training
upon completion of belt press installation.
• Provide on-going training to maintain skills;
video tapes are available for this purpose.
Acknowledgements
This report was prepared for the U.S. Environmental
Protection Agency by Metcalf & Eddy, Inc., Wakefield,
Massachusetts under Contract No. 68-03-3208.
Francis L. Evans III, EPA Project Officer, was re-
sponsible for overall project direction. Other EPA staff
who contributed to this work included:
8
Harry E. Bostian, Technical Project Manager, Water
Engineering Research Laboratory
Walter Gilbert, Office of Municipal Pollution Control
Joseph B. Farrell, Water Engineering Research
Laboratory.
Metcalf & Eddy staff participating in this project
included:
Alan F. Goulart, Project Director
Thomas K. Walsh, Project Manager
Thomas C. McMonagle, Project Engineer
Richard E.S. Toland, Mechanical Specialist
References
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MJ.S.Government Printing Office: 1986 — 646-116/20840
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