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   PART 1 - GENERAL

    01 THE REQUIREMENT

    A. Scope: The Contractor shall supply and install odor control equipment as specified and as shown on the Contract Drawings. The odor control equipment shall include, but may not be limited to, the following:

    1. Reaction Chamber and Accessories

    2. Chemical Supply and Dilution System

    3. Chemical Distribution System

    4. Chemical Storage Tanks

    5. Electrical Control Panel

    6. Exhaust Fan

    7. Blower System

    8. Water Softener System

    9. Ductwork

    B. Reference to Specifications: All odor control equipment and all work connected there with shall conform with all applicable sections of these specifications.

    C. Shop Drawings: The Contractor shall submit complete shop drawings for all odor control equipment in one shop drawing submittal. Shop drawings shall be submitted in accordance with the provisions of Section 01340 of these specifications.

    1.02 PERFORMANCE - GENERAL REQUIREMENTS

    A. The odor control equipment shall be furnished by a manufacture regularly engaged in the manufacture of odor control equipment and systems for wastewater pump stations. The odor control system manufacturer shall produce detailed drawings for complete coordination and installation of the various system components and shall provide the services of a qualified Engineer to supervise the installation and shall test and make any adjustments required at no additional cost to the Owner, to the extent that the system functions as required by these specifications.

    B. The Contractor shall provide all chemicals required for performance testing.

    C. Hydrogen sulfide concentration at the inlet and outlet of the odor control system shall be analyzed by a portable hydrogen sulfide analyzer, manufactured by Interscan Corporation or equal, at least four times over an eight hour period. Failure of the odor control system to meet the specified performance shall require that the performance test be redone until it is demonstrated that the performance requirements are met.

    D. Equipment shall be located and installed so that it will be readily accessible for operation and maintenance.

   PART 2 - PRODUCTS

    02 GENERAL

    A. Process Description: The Contractor shall provide chemical absorption process equipment which uses a solution of water and readily available non-proprietary chemicals for removal of odors. Foul air from the pump station facilities shall be delivered to a scrubber vessel. Diluted sodium hypochlorite and sodium hydroxide shall be introduced into the scrubber vessel at the same locations as the foul air in the form of an atomized mist of 5 to 20 micros in size.

    B. Supplier Responsibilities:

    1. Equipment specified for the complete odor scrubbing system shall be the unit responsibility of the manufacturer of the diluted chemical distribution nozzles to achieve standardization for operation, maintenance, and service. All similar components for each system, such as the foul air fans, air compressors and chemical feed pumps, shall be furnished by the system manufacturer. The Contractor shall be solely responsible for installing complete facilities in accordance with these material and performance specifications, the Contract Drawings, and the system manufacturers requirements. The exact limits of work between the Contractor, its subcontractors, and the equipment supplier/manufacturer shall be established by the Contractor to assure that the system is complete and operable.

    2. Equipment and facilities indicated on the drawings are based on equipment typically provided by Calvert Environmental. The Contractor shall be responsible for determining any changes to the mechanical, civil and electrical designs necessitated by the use of a manufacturer/supplier other than Calvert. All design and construction costs associated with any design changes necessitated by a different supplier/manufacturer shall be borne by the Contractor. All design changes shall be subject to approval by the Engineer.

    3. If the Contractor elects to use the system of a manufacturer/supplier other than Calvert's, it shall submit to the Engineer operational or pilot test data indicating the successful operation of the alternate odor control equipment in wastewater treatment facilities. Such data shall be submitted to the Engineer for review prior to the submittal of equipment shop drawings. No alternate odor control equipment shall be accepted which cannot demonstrate successful operation to the satisfaction of the Engineer.

    B. Performance:

    1. Criteria: Foul air removed from each facility will have an average concentration of hydrogen sulfide (H2S) and design air flow rates as listed below:

    Air Flow H2S

    Location Rate (cfm) Concentration (ppm)

    Bar Screen Structure 12,000 CFM 10 PPM

    1. System Performance: The odor control system shall demonstrate following performance when operating under design flow conditions listed above.

    Inlet Outlet

    1 - 10 ppm H2S 0.1 ppm H2S

    Greater than 10 ppm H2S (1) 99% of inlet

    (1) Maximum 30 ppm H2S

    2. Minimum detention time at maximum air flow shall be 10 seconds.

    03 SCRUBBER CONTACT CHAMBER

    A. General: Each scrubber vessel shall be a fabricated Fiberglass Reinforced Plastic (FRP), concurrent flow tower. Each vessel shall be furnished complete as specified and shown.

    B. All materials and fabrications furnished in accordance with this specification shall comply with all federal and state laws and local ordinances of the place of installation and with the following codes and standards:

    1. Uniform Building Code;

    2. PS 15-69, National Bureau of Standards Voluntary Product Standard, "Custom Contact-Molded Reinforced-Polyester Chemical, Resistant Process Equipment";

    3. ASTM D-3299, "Filament-Wound Glass Fiber Reinforced Polyester Chemical-Resistant Tanks";

    4. ASTM D-883, "Definitions of Terms Relating to Plastics";

    5. ASTM D-2583, "Test for Indentation Hardness of Rigid Plastics by Means of Barcol Impressor";

    6. ASTM D-2563, "Recommended Practice for Classifying Visual Defects in Glass-Reinforced Plastic Laminate Parts";

    B. The odor control system equipment supplier shall be responsible for the complete structural design of each scrubber vessel tower. The odor control system equipment shop drawing submittal shall contain all structural calculations and drawings for the scrubber vessels, clearly indicating key items including, but not limited to, tower wall thickness, anchor bolt size and location, and ladder and platform design. The Engineer will review the structural drawings and calculations for completeness only.

    C. Materials of Construction:

    1. The contact chamber shall be filament-wound, manufactured in accordance with ASTM-D-3299. Contact molded accessories shall be manufactured in accordance with NBS PS 15-69. Any visual defects, per ASTM-D-2563, shall not exceed Level II on the vessel interior and Level III on vessel exterior.

    2. The fiberglass resin shall be a vinylester type such as Derakane 411-45, as manufactured by Dow Chemical Co., Altac 580, as manufactured by ICI America, Hetron 922 by Ashland Chemicals, or an approved equal.

    3. The resin shall be reinforced with an interior Type C fiberglass veil and an exterior continuous, fiberglass filament would reinforcement. A final gel coat is required such that no glass fiber is exposed. The final gel coat shall be pigmented. The color of the gel coat shall be as selected by the Engineer. The fiberglass shall contain an ultraviolet absorber to protect the resin from ultraviolet degradation.

    4. Reinforcement: Glass fiber reinforcement used shall be commercial grade corrosion-resistant borosilicate glass.

    5. All glass fiber reinforcing shall have a silane type surface finish and binder, which is specifically compatible with the particular resin systems to be used. This surface finish should allow the maximum possible chemical bonding between the resin and glass.

    6. Surfacing veils shall be Type "C" (chemical grade) glass, 10 mil thickness, minimum.

    7. Mat shall be Type "E" (electrical grade) glass, 1-1/2 ounces with a nominal fiber length of 1.25 +/- 0.25 inches.

    8. Continuous glass roving, used in a chopper gun for spray-up, shall be Type "E" chopper roving.

    9. Woven roving used for reinforcement shall be 24 ounces per square yard. Type "E" glass and have a 5 x 4 plain weave.

    10. Continuous roving used in filament wound structures shall be Type E glass winder roving, with a yield of 200 yards or more per pound.

    D. Fabrication:

    1. General: Uniform laminate thickness shall be maintained in accordance with ASTM 3299.

    a) All non-mold surfaces shall be coated with resin containing a wax additive in an amount necessary to allow full cure of the surface. In the case of the interior primary corrosion surfaces, the wax coat shall be applied within 24 hours of the original lamination.

    b) All cut edges shall be thoroughly coated with resin including bolt holes so that no glass fibers are exposed. All voids shall be filled with a resin paste using 3 percent millimeter fibers minimum.

    c) No pigments shall be used in any portion of the fabrication.

    2. Corrosion Liner:

    a) The inner surface of all laminates shall be resin-rich and reinforced with one "C"-glass surfacing veil layers. The inner corrosion layer shall not exceed 10 percent glass by weight, and a minimum thickness of 10 to 20 mils.

    b) The inner corrosion layer shall be followed by at least two layers of 1-1/2 ounces chopped-strand mat or two passes of chopped roving to a total of 3 ounces per square foot. Should the chopped roving technique be employed, the chopped fibers shall be 1/2 to 2 inches in length. The total corrosion barrier shall total 100 mils nominal and be 27 percent plus or minus 5 percent glass by weight.

    c) All edges of surfacing veils in wet lay-up shall be lapped a minimum of one inch. A separately cured unreinforced gel coat cannot be used.

    3. Structural Laminates:

    a) The corrosion liner shall be followed by a structural laminate of Filament Wound Construction.

    b) Minimum allowable structural laminate thickness shall be the total thickness specified. Reinforcement shall consist of continuous strand fiberglass roving applied until the specified minimum thickness is attained.

    c) The laminates shall contain not less than 55 percent or more than 70 percent glass (by weight). If for any reason, winding is interrupted to the point where the outer winding is gelled or exotherm temperatures are excessive, production shall stop and the winding shall be allowed to cure. Before winding shall commence, the prominent ridges left by the cured winding strand shall be ground to smooth the projections and minimize bridging. Following the grinding, a layer of 3/4 ounce mat shall be applied and thoroughly rolled to remove air. At this point, winding with continuous strand may be resumed.

    d) Each complete cycle of filament winding shall form a closed pattern of winding bands which completely covers the surface with two plies of bi-directional layers.

    e) "Helix winding" construction shall utilize filament winding within the range of 700, plus or minus 50, selected by the fabricator, as measured from the axial centerline of the tank shell. For chop hoop winding, the winding angle shall be 90 degrees nominal.

    f) Spacing of filaments within the winding band shall be sufficiently close that bridging is avoided, glass content is maintained within the specified limits and uniformity across the winding band without bunching or gaping maintained.

    4. Accessories:

    a) Air inlet, air outlet, hold-down brackets, sampling ports, lifting lugs, manways, anchor plates and duct connections shall be provided by the manufacturer for the contact chamber. Hold-down brackets and lifting lugs shall be integrally molded into the walls of the vessel. Anchor bolts and tie down lugs shall be of 316 stainless steel and shall be designed for the seismic conditions required for Nashville, Tennessee. Reinforcements and gussets for flanges, nozzles, stiffeners, lugs, anchors, brackets, and ducts shall be designed by the vessel manufacturer. The contact chamber shall have a 1-1/2 inch drain with a flanged outlet.

    b) Access manway covers shall be airtight at the pressure equal to or higher than the corresponding fan static pressure and shall be water tight.

    c) The bottom of the scrubber vessel shall be slightly sloped to the drain line.

    d) An aluminum access ladder with safety cage and platform for access to the chemical distribution nozzle shall be provided. The ladder and platform shall be fastened to the reaction vessel and shall comply with all applicable OSHA standards.

    E. Acceptance: The Engineer shall be permitted access to the equipment upon completion for the purpose of verifying compliance to the contract specifications. The Engineer's inspection is not intended to replace the fabricator's own quality control procedures.

    2.02 CHEMICAL FEED AND DILUTION SYSTEM

    A. General: The chemical feed and dilution system takes sodium hypochlorite and sodium hydroxide, dilutes these chemicals, and delivers them to the spray nozzle where the chemical solutions are atomized into a fine mist. Contact between the odorous gases and the chemical mist results in the oxidation of odor-causing compounds.

    The chemical feed and dilution system shall contain all piping and equipment necessary to deliver chemicals from storage tanks to the scrubber vessel or withdraw the chemical required by means of dip tubes from the chemical containing 55 gallon drums.

    B. Chemical Dilution Panels: Each scrubber system shall be provided with a chemical dilution panel as specified herein. The panel shall be fabricated of 10 gauge 304 stainless steel with stainless steel stiffeners. The height and width shall be 6 feet wide x 4 feet high. The panel shall be free-standing. Anchor bolts shall also be 304 stainless steel. The Chemical Dilution Panel shall support the chemical feed pumps and piping, compressed air pressure gauges, water meter and water piping and electrical control panel. The chemical feed system shall contain all those parts necessary to achieve the required concentrations, at the required feed rates for satisfactory performance of the odor control system.

    C. Chemical Metering Pumps:

    1. General: Positive displacement, diaphragm type chemical metering pumps shall be provided to deliver 50 percent sodium hydroxide and 12.5 percent sodium hypochlorite to the scrubber vessel. All chemical metering pumps shall be suitable for 24 hour per day operation. Chemical metering pumps shall be a positive displacement, diaphragm type. The output volume shall be adjustable over a range of 200:1 while pumps are in operation from zero to maximum capacity. Adjustment shall be by means of readily accessible dial knobs, one for changing stroke length and the other for changing stroke frequency, and shall be operationally compatible with the pH sensing devices specified herein. Control of the metering pump shall be selectable between internal and external pulsing by means of a 3-position center-off switch. All pumps shall have a minimum discharge pressure of 35 psig. All pumps greater than 10 gallons per hour shall be motor driven with a minimum discharge pressure of 100 psig.

    2. Operating Conditions:

    Sodium Hydroxide Sodium Hypochlorite

    Flow No. of Pumps Flow No. of Pumps

    (gph) Required (gph) Required

    4.5 2 8 2

    1. Pump Construction: The pump drive shall operate on a 115 volt, 60 hertz, single phase power supply. It shall be housed in a totally enclosed splash-proof control panel with no exposed moving parts. The solid state electronic pulser shall be fully encapsulated. Electronics shall be housed in a chemical resistant enclosure at the control panel end of the pump for maximum protection against chemical spillage. The chemical metering pump housing shall be of chemically resistant glass fiber reinforced thermoplastic with a glass fiber reinforced polypropylene solenoid carrier. All chemical metering pump valves shall be ball type, with ceramic balls seating on a combination valve seat and seal ring. The valve seat and seal ring shall be renewable by replacing only the combination seat-seal ring. The pump head shall be of PVC material. All fittings and connections at pump head shall be PVC. Polyethylene tubing shall be provided complete with compression connections. A foot valve with an integral one piece strainer shall be provided for the suction line and an injection/anti-suction line. An injection/antisyphon check valve with a 1/2-inch NPT male connection shall be provided for the injection point.

    2. Accessories: Each pump shall be provided with a spare parts kit complete with O-rings, gaskets, diaphragms, and accessory parts to repair all check valves.

    3. Control:

    a) Control of each sodium hypochlorite pump flow rate shall be manual. Each pump shall be automatically shut off if a low level is sensed in the appropriate chemical tank. The sodium hydroxide pump shall have a 3 position selector switch, HAND-OFF-AUTO, so that the pumps may be controlled ON/OFF manually or by a discrete 4 to 20 mA signal from the senor monitoring scrubber drainage pH.

    b) Liquid level control devices shall be provided for each chemical feed pump and will shut off the chemical feed pump when the liquid level in the 55 gallon drums or chemical storage tanks has reached its lowest suction level.

    4. Manufacturer:

    a) The sodium hydroxide metering pumps shall be as manufactured by Liquid Metronics with anti-syphon/pressure release valve, or approved equal.

    b) The sodium hypochlorite metering pumps shall be as manufactured by Liquid Metronics with anti-syphon/pressure release valve, or approved equal.

    c) Pumps shall be made of materials compatible with the chemicals to be pumped.

    B. Chemical Dilution Panel Piping:

    1. General: The system manufacturer shall provide all fittings, valves, meters, and gauges required. The system supplier shall submit with its shop drawing and submittal drawings depicting the routing of piping from the chemical dilution panel to the spray nozzle.

    2. Air Piping: Air piping up to the scrubber shall be Schedule 40 carbon steel pipe. Air piping inside the scrubber vessel shall be Type 316, Schedule 40 stainless steel pipe. The air piping shall be routed from the blower to the nozzle directly. A pressure indicator gauge shall be installed to indicate air line pressure.

    3. Water Piping: A 1/2-inch Schedule 80 PVC pipe potable water line shall be connected to the chemical dilution panel. The panel shall contain a pipe union, ball valve, water filter, solenoid valve, pressure reducing valve, check valve, rotameter, and pressure gauge before it connects to the 1/2-inch Schedule 80 PVC chemical pump discharge header. The maximum water flow rate shall be 1 gpm per nozzle. Electrical conduit and wire for the solenoid valve shall be provided and installed between the solenoid valve and the LCP.

    4. Chemical Piping: All chemical metering pumps shall discharge into a common 1/2-inch PVC header through a check valve and a 1/2-inch polyethylene tube. The header shall contain a strainer, a blowdown connection (a tee with a ball valve for draining the line), and 1/2-inch PVC pipe with ball valves to the scrubber vessel spray nozzle.

    5. The spray nozzle connection shall be in accordance with the manufacturer's recommendations, as approved by the Engineer. The Contractor shall provide necessary pipe unions outside the atomization nozzle flange to be able to disconnect and remove the nozzle for maintenance and cleaning.

    C. Automatic pH Control System: The chemical feed system shall be designed for automatic metering and variation of chemical flow. The contact chamber drain liquid shall be continuously monitored and the chemical injection rate of sodium hydroxide automatically adjusted to maintain the pH residual at the set point. Output signals from the senor probe shall be transmitted to the analyzer over standard signal wire. The probe unit shall be automatically temperature compensated and shall have a minimum sensitivity of 0.10 pH. The analyzer shall contain a suitable meter or digital display for indication of the process variable, set point, or controller output. The unit shall contain a two-mode controller (proportional or integral) with an analog output for control of the chemical injection system. An auto-manual switch shall be provided for bumpless and noiseless transfer between modes. The unit shall be provided with suitable switches to increase or decrease the control set point, to allow display of the process variable, set point or controller output, and for setting control action. The unit shall be provided with high and low alarm relays for deviation from set point. Contacts shall be provided for remote alarm transmission.

    1. The pH controller shall be Great Lakes Model 90-P3-B1C1N or equal.

    2.02 CHEMICAL STORAGE TANKS

    A. Sodium Hypochlorite

    1. The chemical storage tanks shall be of fiberglass reinforced plastic construction. The tanks and appurtenances shall meet these specifications and be in conformance with:

    a) ASTM D3299-74 for Filament-Wound Glass Fiber Reinforced Polyester Chemical-Resistant Tanks.

    b) Voluntary Product Standard PS-15-69 for Custom Contact-Molded Reinforced-Polyester Chemical-Resistant Process Equipment.

    c) ASTM D883, "Definitions of Terms Relating to Plastics".

    d) ASTM D2583, "Test for Indentation Hardness of Rigid Plastics by Means of Barcol Impressor".

    e) ASTM D2563, "Recommended Practice for Classifying Visual Defects in Glass Reinforced Plastic Laminate Parts".

    2. The fiberglass reinforced plastic chemical storage tanks provided and installed under this section shall be in accordance with the requirements of Paragraph 2.02, Scrubber Contact Chamber.

    3. The sodium hypochlorite storage tank shall be a maximum of 5 feet in diameter, approximately 7 feet high, and a minimum capacity of 1,000 gallons. The tank and accessory materials shall be completely suitable for and inert to liquid sodium hypochlorite up to 15 percent solution and at ambient, outdoor temperatures.

    4. The tank shall have 24-inch diameter access manway with gasketed and bolted lid of the same material as the tank. The top of each tank shall be fitted with a 3-inch flanged vent pipe connection. The side of each tank shall be fitted with a 2-inch flanged inlet pipe connection, a 2-inch flanged outlet pipe connection, a 2-inch threaded connections for level switch installations. Flanged connections shall be full-faced fiberglass, 150-pound standard drilling. Threaded connections shall be of 316 stainless steel, standard NPT. The tank details showing the locations of all openings, nozzles, and appurtenances shall be included in shop drawings and submitted for approval before fabrication of the chemical storage tank.

    5. Liquid level control devices shall be provided for each chemical metering pump to shut off the chemical metering pump when the liquid level in the appropriate chemical storage tank has reached its lowest suction level.

    6. The storage tank shall be provided with a transparent sight glass for level monitoring.

    7. The Contractor shall provide 1,000 gallons of chemical for start-up of the system.

    B. Sodium Hydroxide

    1. The chemical drums shall be of 55 gallon size and contain a concentration of 50 percent solution.

    2. Liquid level control devices shall be provided for each chemical metering pump to shut off the chemical metering pump when the liquid level in the appropriate chemical drum has reached its lowest suction level.

    3. The Contractor shall provide (4) 55 gallon drums of chemical for start-up of the system.

    2.03 CHEMICAL DISTRIBUTION SYSTEM

    A. The chemical distribution system shall consist of a specially designed atomizing nozzle with all openings greater than 3/16 of an inch. The nozzle shall create a chemical scrubbing mist of 5 to 20 micron sized liquid drops when 200 cfm of blower air at 12 psig is combined by collision with 0.75 gpm of a solution of water and sodium hypochlorite and sodium hydroxide. The chemical distribution nozzle shall be made out of 316 stainless steel and shall be located at the contact chamber inlet. The nozzle shall use two opposing jets to shear the solution into finely atomized drops. The drops shall be evenly dispersed at the vessel inlet and allow oxidation of the odorous compounds to the levels of performance specified. The nozzle shall be capable of being easily removed from its location in the vessel by disconnectable unions.

    2.04 BLOWER SYSTEMS

    A. General: The Contractor shall furnish and install rotary positive displacement type air blowers of Involute design with electric motor and dual V-belt drive system suitable for continuous operation 24 hours per day. Ambient air temperature can be defined as between 400F and 1000F. The blower driving unit shall be by pulley and sheave connected to a fixed speed quiet-type high efficiency TEFC electric motor. The blowers shall be installed complete with all necessary accessories, drives, piping, fittings, valves, flexible connectors, silencers, vibration isolators, safety devices and controls to obtain workable installation as shown and specified.

    B. Blower Operating Conditions:

    1. Inlet Pressure: 14.7 psia

    2. Inlet Temperature: Ambient

    3. Discharge Pressure: 12 psig minimum

    4. Maximum Noise: 65 dba

    5. Minimum HP: 20 HP

    6. Minimum Capacity: 200 SCFM

    C. Materials and Construction:

    1. Impellers: Cast iron, machined, permanently fastened to steel shaft, dynamically balanced.

    2. Headplates: Case iron, machined and ground internally to close tolerances.

    3. Impeller Case: Cast iron, machined, with heavy rib reinforcement to prevent distortion. Inlet and discharge ports are an integral part of impeller case.

    4. Bearings: Anti-friction bearings with thrust control. Single or double row ball bearing and spherical roller bearing for greater overhung load capacity.

    5. Timing Gear: Steel, accurately cut and fastened to blower shaft.

    6. Lubrication: Oil splash lubrication from oil tight housing. Drive-end bearings are grease lubricated, with lip-type seals to prevent oil and grease from entering in impeller chamber.

    7. Drive Shaft: Extended steel shaft for V-belt drive, including thrust control.

    8. Drive: V-belt drive with OSHA safety guard, removable mesh screen on front for easy access.

    9. Base: Fabricated structural steel base, shall be provided common to motor and drive.

    D. Drive: Explosion proof electric motor, suitable for outdoor installation, for 480 volt, 3 phase, 60 Hz supply (Class I, Div. I).

    E. Accessories: Each blower shall be furnished as a complete preassembled unit with the following accessories:

    1. One (1) air intake filter.

    2. One (1) air intake silencer.

    3. One (1) discharge silencer.

    4. Two (2) flexible connectors.

    5. One (1) pressure relief valve.

    6. One (1) butterfly valve suitable for hot gases at discharge.

    7. One (1) check valve.

    8. One (1) pressure gauge with valve.

    9. One (1) temperature switch.

    10. One (1) temperature gauge.

    11. One (1) safety guard

    12. And all necessary pipes, fittings, supports, and controls.

    F. Spare Parts: Each blower shall be furnished with the following spare parts:

    1. Intake filter element (2 spares).

    2. Set of drive belts.

    G. Manufacturer: Roots (Dresser Industries, Inc.), Sutorbilt or approved equal.

    2.05 EXHAUST FANS

    A. General: The Contractor shall supply and install FRP foul air exhaust fan. The fans shall be dual V-belt drive, designed for continuous, 24 hour per day service.

    1. Fan shall be fiberglass reinforced plastic, centrifugal type with backwardly inclined wheel of non overloading design, SISW, Class II, industrial fiberglass fan or inline vane-axial type with arrangement as shown on the Drawings. Fan wheel shall be statically and dynamically balanced. Fiberglass construction shall conform to PS 15-69 product standards. Fan resin shall be suitable for exposure to the specified service conditions. Fan housings shall be grounded to support bases. All fan housings shall be constructed of fiberglass and reinforced with rigid bracing to increase structural integrity. Bearing support brackets shall be positioned to directly oppose belt tension forces.

    2. Fan housings shall be of a curved scroll design with a 1-inch NPT drain connection at the bottom of the fan scroll. Fan intake and outlets shall have flanged nozzles.

    3. Fan shafts shall be stainless steel Type 316. Fan shall have self-aligning grease-packed bearings, with neoprene shaft seals and OSHA approved weatherproof FRP motor/drive cover.

    B. Fan Operating Conditions:

    1. Service: Foul air - hydrogen sulfide

    2. Elevation Above Sea (Ft.): 421.00

    3. Inlet Temperature (0F): Ambient

    4. Relative Humidity (%): 100

    5. Air Flow Rate (CFM): 12,000

    6. Minimum Horsepower (H.P.): 10

    7. Static Pressure (in W.C.): 2.5

    C. Motor:

    1. Motor shall be squirrel cage induction type, designed, manufactured, and tested in accordance with the latest edition of NEMA MG1.

    2. Motor shall be horizontal, explosion proof (Class I, Div. I), single-speed, with nonhygroscopic insulation, extra dips and bakes of insulating varnish for moisture protection of windings, gasketed conduit box halves and moisture seal between conduit box and motor frame, and drains and breathers for moisture removal.

    3. The connected load (maximum horsepower required) of motor shall not exceed its nameplate horsepower rating (exclusive of 1.15 service factor) under any anticipated operating condition.

    4. Motor shall be NEMA Design B unless otherwise indicated.

    5. Motor shall be rated for a temperature rise of 40 degrees centigrade above ambient temperature.

    6. Motors shall have a grounding terminal in the connection box.

    7. If motor is subjected to overhanging loads, it shall be designed for such loads. The magnitude of overhanging load shall not exceed the recommendations of the motor manufacturer.

    8. Bearings shall be open-type ball bearings installed in labyrinth sealed end bells with pipe plugs.

    D. Manufacturer: The fan shall be New York Blower, Harrington Plastics, Industrial Air or approved equal.

    2.06 WATER SOFTENER SYSTEM

    A. General:

    1. The purpose of the water softener will be to soften feedwater to the odor control unit. The softener shall be capable of removing hardness to not more than 0.5 grains hardness when operated at 4 gallons per minute maximum. Unit shall be 115-volt, single phase.

    2. The water softener shall be self-regenerating type duplex water softener system of suitable capacity required for proper operation of the system. The water softener shall have a minimum salt storage capacity of 200 lbs. The manufacturer shall be responsible for supplying diagrams for all piping connections to and from the water softener. Water softeners shall have an average treated water capacity of 4 gpm and shall be suitable for outdoor installation.

    B. Manufacturer: Culligan, Rayne or approved equal.

    2.07 CONTROLS

    A. General:

    1. The operation of each odor control system shall be controlled from the Odor Control Local Control Panel (OC-LCP). The panel equipment, operational sequences, and indication/alarm functions are described in this subsection.

    2. Each OC-LCP shall provide for both coordinated and independent operation of the water supply, compressed air supply, chemical metering system, and exhaust fan.

    B. Control Panel Equipment:

    1. The panel shall contain ON/OFF switches and run indicating lights for:

    a) System master switch

    b) Exhaust fan

    c) Air compressor

    d) Dilution water solenoid valve

    e) Sodium hypochlorite pumps

    f) Sodium hydroxide pump

    2. The control panel shall indicate system drainage pH which will control the sodium hydroxide pump, and low level indicator lights for NaOC1 and NaOH.

    3. Control panel shall be NEMA 4. It shall be mounted on a stainless steel frame as shown on the Drawings. OC-LCP shall be furnished completely pre-wired with factory mounted instruments, controls, and indicators as required.

    04 FIBERGLASS DUCT WORK

    A. General: Rectangular, square, and circular-shaped fiberglass (FRP) air ducts and plenums shall be provided as required. All fittings shall be fiberglass. Smooth bends or internal turning vanes shall be provided at elbows, tees and other points in the duct systems where air flow changes direction. The odor system manufacturer shall size the inlet ducting as required for system operation. Fiberglass ducts shall be manufactured by Calvert Environmental or an approved equal.

    B. Resin: Fiberglass ducting shall be constructed of fiberglass reinforced polyester resin. Resin used shall conform to the applicable sections of ASTM C581-68. No thixotropic agent shall be added to resin used on the interior surface of any duct in contact with scrubber exhaust.

    C. Reinforcement: FRP duct shall be fabricated by the filament winding method or hand lay up, for tubular shapes, using a "helix angle" of 700 +/- 50. The corrosion liner of the duct shall be fabricated using one "c" veil and 1 chopped strand mat (1-1/2 oz.) or 1 layer of chopped strand prior to filament winding. The minimum liner thickness shall be 30 mils. All non-tubular shapes shall be fabricated by the hand layup, chopped strand or a combination of both using the specified corrosion liner.

    D. Physical Properties of Laminate: The laminate shall, in all cases, have the following physical properties:

    Physical Properties (at 730F) ASTM Test Units Value

    Minimum Ultim. Tensile Strength D638 psi 12,500

    Minimum Flexural Strength D790 psi 19,000

    Minimum Flexural Modulus of D790 psi 800,000

    Elasticity (tangent)

    E. Fabrication: As a minimum, and unless otherwise specified, laminate materials of construction and fabrication of fiberglass ducts and plenums shall be in accordance with the National Bureau of Standards "Voluntary Product Standard PS 15-69" for molded reinforced polyester chemical-resistant process equipment, Sections 3.1.1 - 3.4.9. The exterior surface of the ducting shall be suitable for a corrosive environment and shall conform to Section 3.3.3.1 of PS 15-69. For all interior duct surfaces, the inner veil of reinforcement should overlap, providing reinforcement base for 100 percent of the interior surface of the duct. Ducting shall be specifically designed to facilitate water drainage where indicated on the Drawings; raised lips at duct shall not be accepted.

    F. Duct Wall Thickness: Wall thickness shall be 1/4-inch, with the exception of isolated small spots which may be as thin as 3/16-inch. In no case shall the wall thickness be less than 3/16-inch. Additional thickness may be required to meet deflection requirements.

    G. Duct Dimensions: The duct and plenum dimensions are net inside, indicating the clear space required inside the duct or plenum after lining is installed. Actual duct dimensions shall be increased to accommodate lining material, where lining is required. The system manufacturer shall size the intake and exhaust ducts for the odor control system. The duct system shall be dampered to balance the air flow from the bar screen structure.

    H. Field Joints: Field joints shall be made by wrapping using RMRMR sequence with strips of reinforcement saturated with resin, the reinforcement being at least the thickness of the heaviest plastic section being joined. Extension to a sufficient distance on each side of the joint is required to make the joint at least as strong as the pieces joined. Mating edges shall be filled with resin paste to cover cut edges and fill voids. The inside surface of the joint shall be sealed with one layer of reinforcement where accessible.

    I. Flanges: Flanges shall conform to the specifications in ASTM 4024, PS 15-69, Sections 3.4.7.1 to 3.4.7.5.

    J. Ducting Deflection: The duct work shall be designed to meet the following specification with respect to supports. Supports shall be furnished by the Contractor at no extra cost. Maximum deflection of a side on a rectangular duct shall not exceed 2 percent or S" of the duct diameter under an imposed hoop (point) loading of 550 lbs. After installation, horizontal rectangular ducting shall not sag in excess of 2 percent of the shortest side as measured from a straight and true centerline of the duct to the actual midpoint of the installed duct. Similarly, maximum sag of horizontally installed round duct shall not exceed 2 percent of the diameter. Duct supports shall be designed and installed such that the maximum deflections and sags specified are not required to meet the deflection requirements. Any internal support components of the duct work shall not increase the system pressure drop.

    K. Workmanship: The finished laminate shall be free from visual defects such as foreign inclusions, dry spots, air bubbles, pin holes, pimples, delamination, exposed reinforcement (glass fibers), and runoff and shall conform to ASTM D2563, Level II for visual defects. The exterior surface shall be smooth, with no sharp projections. Care shall be taken to fill voids and crevices at joints and fittings.

    Representative laminate samples shall be sent to the Engineer prior to fabrication for approval of surface finish and visual defects. The fabricated work shall be identical in surface finish and visual defects.

    L. Supports: The Contractor shall support all runs of duct at least every 5 feet and more frequently if required to meet the sag requirements specified herein. Supports shall be fabricated out of aluminum and designed to meet the installation requirements. Calculations shall be furnished for alternative spacing. Attachment of the supports to fiberglass ducting with screws is unacceptable.

    M. Certification: The FRP duct work supplier shall provide certification for the following:

    1. The resin used has been tested in accordance with ASTM C581 and that the resin is compatible with an environment consisting of air, hydrogen sulfide gas, methane, various aromatic hydrocarbon vapors, droplets of salt water, and droplets of water containing sodium hypochlorite, sodium hydroxide, and sulfuric acid.

    2. The fiberglass used has a flame spread rating of 25 or less and as measured in accordance with NFPA No. 255, "Standard Method of Test for Surface Burning Characteristics of Building Materials".

    3. The duct work supplied meets the visual defects level and the deflection requirements under the design vacuum pressure and hoop (point) loading specified herein.

   PART 3 - EXECUTION

    05 START-UP AND TESTING

    A. General: The Contractor shall be responsible for the successful start-up and testing of the odor control facility. The Contractor shall provide all necessary facilities, manpower, chemicals, tools, instrumentation, required during this phase of the work.

    B. Start-Up: The start-up of the odor control facility shall be accomplished under the supervision of an experienced start-up Engineer from the manufacturer/supplier. The start-up Engineer shall be at the job site for a minimum of three (3) working days to inspect the installation and direct the start-up of each system.

    C. Performance Testing: Performance testing shall be as specified in Subsection 1.02. At the conclusion of the test, the Contractor shall submit a complete test report to the Engineer, which shall include summaries of all test results.

    06 OPERATION AND MAINTENANCE INSTRUCTION AND MANUAL

    A. The Contractor shall provide for the services of personnel from the manufacturer/supplier experienced in providing operation and maintenance instruction to the Owner's personnel for a minimum of three (3) days. The odor control manufacturer shall provide operation and maintenance manual as specified in Section 01730.

    END OF SECTION