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Inclined Plate Clarifier with Sludge Thickening Bottom
PART 1 - GENERAL
1.1 Scope: The work covered in this section includes furnishing
all labor, material, equipment and incidents to install complete and
ready for operation, an inclined plate clarification device as shown on
drawings and as specified herein.
1.2 APPLICABLE PUBLICATIONS: The publications listed below form a
part of this specification to the extent referenced. The publications
are referred to in the text by the basic designation only.
American National Standards Institute (ANSI) Publication:
B16.1 Cast Iron Pipe Flanges and Flanged Fittings, Class 25, 125, 250 and 800
American Society for Testing and Materials (ASTM) Publications:
A-36 Structural Steel
A-53 Pipe, Steel, Black and Hot Dipped, Zinc Coated, Welded Seamless
A283 Low and Intermediate Steel Plate of Structural Quality
A-53 Pipe, Steel, Black and Hot Dipped, Zinc Coated, Welded Seamless
A283 Low and Intermediate Steel Plate of Structural Quality
American Welding Society (AWS) Publications:
D1.1-84 Structural Welding Code, Steel
A5.1 Mild Steel Arc-Welding Electrodes
A5.1 Mild Steel Arc-Welding Electrodes
Standard Welding Terms and Definitions
Standard Welding Symbols
Steel Structures Painting Council (SSPC) Publication:
SSPC-SP-10 Near White Blast Cleaning
American Institute of Steel Construction (AISC) Steel Construction Manual, 8th Edition
1.3 SUBMITTALS:
1.3.1 Contracting officer will review and approve all submittals.
1.3.2. Submit the following before fabrication
1.3.2.1 Shop Drawings: Shop drawings for clarification and
accessory equipment including principle dimensions and location of
fittings. Data shall include weight and distribution of weight with the
unit empty and filled with water.
1.3.2.2 Test results, signed by the manufacturer, which indicate
the clarifier is capable of handling specified effluent concentration,
pH, fluid temperature and concentration of suspended solids. Tests on
this model shall have been done within the last 3 years.
1.3.2.3 Provide calculations of clarifier loading rate at the design flow rate.
1.3.3 Submit the following after fabrication:
1.3.3.1 Verification:
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Written verification on the fabricator’s letterhead that surface preparation and coating application were performed in accordance with the specification and coating specification and system manufacturer’s printed recommendations;
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That the unit was hydraulically leak tested for a period of at least 4 hours before further surface preparation and coating;
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That the surface preparation and coating process was performed at a facility owned and operated by the manufacturer;
1.4 MANUFACTURER’S SERVICE REPRESENTATIVE’S REPORT AND
CERTIFICATE: Submit service representative’s complete signed report of
results of the inspection, operation, adjustment, and tests. Report
shall include detailed descriptions of points inspected, tests and
adjustments made, quantitative results obtained if such are specified,
and suggestions for precautions to be taken to ensure proper
maintenance. Include the manufacturer’s certificate that equipment
conforms to specified requirements and is ready for permanent operation
and that nothing in installation will render manufacturer’s warranty
null and void.
1.5 DELIVERY, STORAGE, AND HANDLING MATERIALS:
1.5.1 Delivery and Storage: Inspect materials delivered to site
for damage; unload and store with minimum handling. Store materials on
site in enclosures or under protective coverings. Protect materials not
suitable for outdoor storage to prevent damage during periods of
inclement weather, including subfreezing temperatures, precipitation,
and high winds. Store materials susceptible to deterioration by direct
sunlight under cover and avoid damage due to high temperatures. Do not
store materials on ground. Store and protect materials according to
manufacturer recommendations.
1.5.2 Handling: Handle inclined plate clarifier in such a manner
as to ensure delivery to final location in sound, undamaged condition.
Take special care not to damage interior and exterior surfaces of the
inclined plate clarifier. Make satisfactory repairs to damaged
material(s) at no cost. Carry and do not drag materials. Handle
inclined plate clarifier according to manufacturers information.
1.6 QUALITY ASSURANCE:
1.6.1 Inspection: Examine each component of clarifier for
compliance with requirements specified. Redesign or modification of
equipment to comply with specified requirements, or necessary redesign
or modification following failure to meet specified requirements, shall
receive particular attention for adequacy and suitability. This element
of inspection shall encompass visual examinations and dimensional
measurements. Noncompliance with specified requirements, or presence of
one or more defects preventing or lessening maximum efficiency of
clarifier operation, shall constitute cause for rejection.
1.7 WELDER QUALIFICATIONS:
1.7.1 Welders shall be previously qualified by passing the tests
prescribed in the AWS Standard Qualification Procedure, or by passing
such other tests as the Engineer may accept.
1.7.2 Welders shall have been tested within the past twenty four
months and their qualifications shall be considered as remaining in
effect unless the welder is not engaged in a given process of welding
for a period exceeding six months.
PART 2 - INCLINED PLATE CLARIFIER DESIGN CRITERIA AND MANUFACTURING SPECIFICATIONS
2.1 INCLINED PLATE CLARIFIER - APPLICATIONS & PERFORMANCE
2.1.1 Applications: The inclined plate clarifier shall be used to
separate entrained suspended solids from a wastewater stream having a
flow rate of * gallons per minute. Water entering the
flash mix section has previously been conditioned to destabilize micro
colloidal suspended solids. Two additional compartmental tanks with
mixers are provided to flash mix an activated polyelectrolyte with the
conditioned wastewater and then slowly flocculate the suspended solids
into easily settleable masses.
*COMPLETE BLANKS FROM ATTACHED CHART
The flocculated suspended solids precipitate from entrainment as
the hydraulic flows moves through the clarifier’s inclined plates,
collect and slide down the incline, falling into the clarifier sludge
hopper. The settled sludges collect on the bottom of the sludge hopper
and are mechanically raked to the center of the tank and discharged on
an as needed basis to a filter press or sludge thickener via air
diaphragm pumps. The clarified water gravity flows from the top of the
clarifier to a sand filter or discharge.
2.1.2 Performance: The clarifier shall remove the at least 98% of
the destabilized and conditioned micro colloidal suspended solids from * gallons per minute flow and be designed
with a flat bottom center outlet to thicken the collected solids to 3-5
percent by weight.
2.2 Inclined Plate Clarifier - Manufacturing specification
2.2.1 The manufacturer of the inclined plate clarifier and related
components shall have been manufacturing clarifiers of the following
specified design for at least five years. The clarifier and components
shall be fabricated and assembled at the steel fabrication facility
owned and operated by the manufacturer. Sandblasting and coating
operations shall also be performed at the manufacturers’ facility. The
manufacturer shall maintain a quality control staff to perform quality
assurance checks during fabrication and assembly.
2.2.2 Inclined plates shall be set at a minimum of 60 degrees above the horizontal plane.
2.2.3 The maximum flow rate through the inclined plate clarifier
shall not exceed 0.25 gallons per minute per square foot of horizontal
projected area. (Horizontal projected area of an inclined plate set at
60° is 50% of the total surface are).
2.2.4 Forced uniform flow throughout the inclined plate section
shall be created to assure that each plate received an equal amount of
flow and that the flow is distributed over the entire effective width
of each plate without short circuiting by the incorporation of dual
orifices located at least 6" above and on both sides of the plate
sections. The orifices shall be in two rows located at 2" and 3"
respectively below the top overflow weir. The orifice shall be of a
diameter that at maximum design capacity restricts the flow rate to
create a 2" pressure drop through each orifice. Custom molded Viton or
rubber grommets shall be inserted in each hole. The manufacturer shall
supply data of a installation with at least five years operating
experience that demonstrates this method of flow equalization. Center
mounted effluent collection structures do not provide uniform flow
across the plate section and are not acceptable. V-notch weirs do not
provide uniform flow and thus are not acceptable.
2.2.5 To ensure full utilization of all plate areas and to prevent
the shearing of floc particles, Velocities through the unit shall be
kept below 1 FPS. Flow velocity calculation shall be submitted for feed
ducts, feed bay and plate separators.
2.2.6 The clarifier shall be provided with minimum 4 inch freeboard at design flow rate.
2.2.7 The minimum plate spacing shall be 2 inches. Plates shall be
fabricated of fiber reinforced plastic. The plates shall be supported
by dividers constructed of stainless steel, Teflon or molded plastic
inserts and shall be individually removable.
2.2.8 The settling plates shall have a length to width ratio of
* to
1. The plates shall be a minimum of 0.09 inches thick FRP. The plates
shall have a resin rich surface to prevent fiber show. The plates shall
be produced by contact molding or machine extrusion, "hand or spray
lay-up fabrication" will not be acceptable.
2.2.9 The plates shall be 24" wide supported on the sides and
center, such that unsupported distances shall not exceed 12". Settling
plates wider than 24" shall be supported on 12" center or provide
documentation and test results that the plates will withstand a load of
100% filled with sludge, specific gravity 1.4 or above, with all water
drained from the clarifier, without plate collapsing. Manufacturer
shall provide a minimum of five installation references with at least
five years service without failure.
2.2.10 Gasket materials utilized in the plate construction shall
be Viton or Teflon. All assembly clips shall be constructed of Teflon.
2.2.11 Inlet and outlet shall be flanged connections drilled to ANSI B16.1.
2.3 MANUFACTURING SPECIFICATIONS - INTEGRAL SLUDGE HOPPER
2.3.1 The inclined plate clarifier shall have an integral sludge
hopper located below the plate zone. The sludge compartment shall be
supplied with a flat bottom and have a top driven motorized rake to
break up and direct sludge to a central discharge compartment.
2.3.2 The sludge hopper shall have three (3) sludge samples 3/4" NPT nipples and a 20 inch manway.
*COMPLETE BLANKS FROM ATTACHED CHART
2.3.3 The rake shall be a cantilevered design with the motorized
drive, supported above the solution to eliminate submerged rotating
seals. The rake drive shaft shall have a bottom mounted steady rest
support. All seals and bearings shall be above the water surface. The
high efficiency cyclical gear motor shall have at least * inch pounds of torque and be driven by a 440V, 3 phase, TEFC motor. The horsepower shall not exceed
* . Worm gear reducers are not acceptable.
2.3.4 The sludge hopper shall have a volume of at least
* gallons.
2.3.5 Two (2) zinc anodes mounted to 3/4" male pipe plugs shall be mounted in the hopper above the rake for galvanic protection.
2.4 Manufacturing Specifications - Flash Mix and Flocculate Section
2.4.1 Rapid mix tank shall have a minimum detention time of 30 seconds at design flow rate.
2.4.2 Rapid mixer to be a single speed (maximum output speed 70
rpm) mixer comprised of vertical shafted mixer with at least 75% length
of the mix chamber height, gear reducer and motor. The mixer shall have
a rigidly mounted bottom steady rest support. The gear motor shall
provide at least 300 inch pounds of torque and be driven by a 440V, 3
phase TEFC motor. All seals and bearings shall be above the water
surface.
2.4.3 Flocculating tank shall have a minimum detention time of 2
minutes at design flow rate with a motorized vertical shaft mixer,
variable speed, that supplies low turbulent motion to build the floc.
2.4.4 Flocculate mixer shall be a variable speed mixer 5 to 1
ratio with a maximum speed not to exceed 40 rpm’s comprised of mixer
paddles, variable gear reducer and TEFC motor. The gear motor shall
provide at least 300 inch pound of torque at maximum speed and shall be
driven by a 440V, 3 phase motor. The mixer shaft shall have a rigidly
mounted bottom steady rest support. All seals and bearings shall be
above the water surface.
2.4.5 Rapid mix tank and flocculating tank to have a minimum 4 inch freeboard at the design flow rate.
2.4.6 Rapid mix tank shall have a chemical injection pipe connection for injection of polymer directly below flash mixer.
*COMPLETE BLANKS FROM ATTACHED CHART
2.4.7 The rapid mix and flocculate tank shall be equipped with at least 3 integral anti-vortexing baffles.
2.5 MANUFACTURING SPECIFICATIONS - PLATFORM
2.5.1 A platform shall be included for the inspection of the rapid mix, flocculating and clarifier compartment.
2.5.2 Access to the platform shall be provided by ladder. A cage shall be included if the ladder exceeds 20 feet.
2.5.3 Platform floor grating shall be coated for corrosion resistance.
2.5.4 The platform shall have a handrail to protect personnel. The
opening between the rails shall be in compliance with OSHA and UBC
standards and shall not exceed 12 inches.
2.6 STRUCTURAL
2.6.1 All structural and tank steel stresses shall be within the
allowable limits shown in the Steel Construction Manual of the American
Institute of Steel Construction, Eighth Edition.
2.6.2 The unit to be structurally designed for installation in Seismic Zone
* in accordance with 1985 Uniform Building Code.
2.6.3 Clarifier shall be fabricated from ASTM A-36 steel.
2.6.4 All exterior welds shall be continuous seal weld or the weld must be caulked before surface coating.
2.7 ELECTRICAL:
2.7.1 Rapid mixer, flocculate drive and sludge drive unit shall have 440V, 60 Hz, 3 phase TEFC or TENV motors, maximum 1 HP.
2.7.2 The drives shall be remotely started and stopped.
2.8 TESTING:
2.8.1 All seal welds shall be visually checked for continuity, pinholes, and voids.
2.8.2 The entire unit shall be shop-hydrostatically tested. Documentation of hydrostatic test shall be provided.
*COMPLETE BLANKS FROM ATTACHED CHART
2.9 SURFACE PREPARATION AND COATING
2.9.1 Surface Preparation: The steel surfaces must be dry and
clean in accordance with the following requirements. Remove all grease,
oils and contaminants as outlined in SSPC SP1. Remove all weld splatter
and grind burrs on cut edges and rough welds smooth. Blast clean all
surfaces after fabrication in accordance with SSPC SP10 with profile
depth of 1.5-2.0 mils. Apply first primer before any rust bloom forms.
2.9.2 Caulking: All exterior non-seal welding joints shall be filled with rubber caulking before painting.
2.9.3 Exterior Surfaces:
Shop First Coat: Apply one coat average dry film thickness of two
mils minimum, of a high-build catalyzed epoxy. Apply to all steel
surfaces except the areas within 2 inches adjacent to field welds and
surfaces specified to be hot-dip galvanized. The paint shall be Hempel
4563U.
Shop Finish Coat: Apply one coat average dry film thickness of 1.0
mils minimum, of a polyurethane paint. Recoat at time interval
recommended by the manufacturer, the final coat shall be Hempel 5595U.
Third Coat: Field touch-up of damaged and unpainted areas shall be
the same as specified first and second coats at the same film thickness.
The total dry film thickness shall be an average of 4 mils.
2.9.4 Interior Surfaces:
Shop First Coat: Apply one coat average, dry film thickness of
four mils, of an immersion grade high-build catalyzed epoxy. Apply to
all steel surfaces except the areas within 2 inches adjacent to field
welds and surfaces specified to be hot-dip galvanized. The paint shall
be Hempel 15409.
Shop Finish Coat: Apply one coat average, dry film thickness of 4
mils, of an immersion grade high-build catalyzed epoxy. Recoat at time
interval recommended by the manufacturer, the final coat shall be
Hempel 15409.
Third Coat: Field touch-up of damaged and unpainted areas shall be
the same as specified first and second coats at the same film
thickness. (Liquid Contact).
The dry film thickness shall be an average of 6 mils.
PART 3 - DELIVERY, STORAGE AND HANDLING MATERIALS
3.1 Delivery and Storage: Inspect materials delivered to site for
damage; unload and store with minimum handling. Store materials on-site
in enclosures or under protective coverings. Protect materials not
suitable for outdoor storage to prevent damage during periods of
inclement weather, including subfreezing temperatures, precipitation
and high winds. Store material susceptible to deterioration by direct
sunlight under cover and avoid damage due to high temperatures. Do not
store materials directly on ground. If special precautions are
required, prominently and legibly stencil instruction for such
precautions on outside of equipment or its crating. Store and protect
materials according to manufacturers recommendations.
3.2 Handling: Handle sludge thickener tank in such a manner as to
ensure delivery to final location in sound, undamaged condition. Take
special care not to damage interior and exterior surfaces of sludge
thickener tank and associated supports and pipe coatings or linings.
Make satisfactory repairs to damaged material(s) at no cost. Carry and
do not drag materials. Handle sludge thickener tank according to
manufacturers information.
PART 4 - EXECUTION
4.1 Installation: Inclined plate clarifier tanks to be installed
as indicated and as recommended by the manufacturer. Equipment
delivered to the site in advance of installation to be stored per the
manufacturer’s requirements. Make all connections as required to make
inclined plate clarifier fully operational. Do not weld tank surfaces,
interior or exterior, it will permanently damage the interior lining.
If welding has inadvertently occurred, the interior surface affected
shall be abrasively ground to white metal and two coats of Hempel 15409
applied, with air dry between coatings.
4.2 Field Inspection Services: Examine each component of inclined
plate clarifier for compliance with requirements specified. Redesign or
modification of equipment to comply with specified requirements, or
necessary redesign or modification following failure to meet specified
requirements, shall receive particular attention for adequacy and
suitability. This element of inspection shall encompass visual
examinations and dimensional measurements. Noncompliance with specified
requirements, or presence of one or more defects preventing or
lessening maximum efficiency of inclined plate clarifier operation,
shall constitute cause for rejection.
4.3 Start-Up Testing: Manufacturer’s field representative shall
inspect and test unit and certify that the installation has been
performed in accordance with manufacturer’s recommendations and that
the system is ready for operation by others. Inspection shall consider,
but not be limited to, the following:
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Soundness (without cracked or otherwise damaged parts).
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Completeness in all details, as specified.
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Correctness of settling alignment, set points and relative arrangement of each component.
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Confirm that the unit is level within ¼" side to side and end to end.
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Inspect unit for leakage and that all mixers are operating as specified.
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Inspect coating integrity to insure installation contractor has applied touch-up paint to all scratches, blemishes and/or coating discontinuity that occurred during shipping and installation.
PART 5 - SUGGESTED MANUFACTURER:
The inclined plate clarifier shall be model number #
* manufactured by:
Hoffland Environmental, Inc.
10391 Silver Springs Road
Conroe, Texas 77303
10391 Silver Springs Road
Conroe, Texas 77303
(936) 856-4515 phone / (936) 856-4589 fax
e-mail: [email protected]
e-mail: [email protected]
*Model Number
*
*Check following page for alternates.
*Check following page for alternates.
*COMPLETE BLANKS FROM ATTACHED CHART
HOFFLAND ENVIRONMENTAL, INC.
MOTORIZED RAKE SLUDGE THICKENING BOTTOM SLUDGE HOPPER
MOTORIZED RAKE SLUDGE THICKENING BOTTOM SLUDGE HOPPER
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