Attach 11 cooling tower REV 2.pdf

NIST BOULDER B42 - Cooling Tower Capacity Upgrade

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COOLING TOWER REQUIREMENTS

PART 1 - GENERAL

1.2 SUMMARY

A. This Section includes factory assembled and tested, open circuit mechanical induced-draft vertical discharge cooling tower.

1.4 QUALITY ASSURANCE

A. Verification of Performance:

1. The thermal performance shall be certified by the Cooling Technology Institute in accordance with CTI Certification Standard STD-201. Lacking such certification, a field acceptance test shall be conducted within the warranty period in accordance with CTI Acceptance Test Code ATC-105, by a Certified CTI Thermal Testing Agency. The Evaporative Heat Rejection Equipment shall comply with the energy efficiency requirements of ASHRAE Standard 90.1.

2. Unit Sound Performance ratings shall be tested according to CTI ATC-128 standard.

Sound ratings shall not exceed specified ratings.

B. Unit shall meet or exceed energy efficiency per ASHRAE 90.1

1.5 WARRANTY

A. written warranty executed by the manufacturer, agreeing to repair or replace components of the unit that fail in materials and workmanship within the specified warranty period.

1. The Entire Unit shall have a comprehensive five (5) year warranty against defects in materials and workmanship from date of shipment.

2. Fan Motor/Drive System: Warranty Period shall be Five (5) years from date of unit shipment from Factory (fan motor(s), fan(s), fan shaft(s), bearings, mechanical support, sheaves, bushings and belt(s)).

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Manufacturers: Subject to compliance with requirements, provide cooling towers manufactured by one of the following:

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1. EVAPCO model USS

2. or equal

2.2 IBC COMPLIANCE

A. The unit structure shall be designed, analyzed, and constructed in accordance with the latest edition of International Building Code (IBC) for: IP = 1.0, SDS = 1.34; z/h = 0, P = 119 psf.

2.3 COMPONENTS

A. Description: Factory assembled and tested, induced draft counter flow cooling tower complete with fan, fill, louvers, accessories and rigging supports

B. Materials of Construction

1. All cold-water basin components including vertical supports, air inlet louver frames and panels up to rigging seam shall be constructed of Type 304 Stainless Steel. All factory cold water basin seams shall be welded for watertight construction.

2. Casing and fan section, including channels and angle supports, shall be constructed of Type 304 stainless steel. Fan cowl and guard shall be constructed of Type 304 Stainless Steel. "Series 300" stainless steel will not be acceptable as equivalent to Type 304 Stainless Steel.

C. FM Approved Construction

1. Unit shall be listed in the current FM Approval Guide and conform to the latest edition of the FM Approval Standard for Cooling Towers, Class Number 4930. The unit shall include stainless steel water distribution, 1" x 1" stainless steel screen covering the air inlet louvers and stainless-steel partitions. A copy of the FM Approval Certificate of Compliance shall be available upon request.

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D. Fan(s):

1. Fan(s) shall be high efficiency axial propeller type with aluminum wide chord blade construction. Each fan shall be dynamically balanced and installed in a closely fitted cowl with venturi air inlet for maximum fan efficiency.

2. Provide low sound fans, with the following performance:

Sound Pressure Level (dB) End Motor Side Opp End Opp Mtr. Side Top Sound

Power Level (db)

5 ft 50 ft 5 ft 50 ft 5 ft 50ft 5ft 50ft 5ft 50 ft

Band

63 HZ

125 HZ

250 HZ

500 HZ

KHZ

KHZ

4 KHZ

8 KHZ

Calc dBA

E. Drift Eliminators

1. Drift eliminators shall be constructed entirely of Polyvinyl Chloride (PVC) in easily handled sections. Design shall incorporate three changes in air direction and limit the water carryover to a maximum of 0.001% of the recirculating water rate. Drift eliminators shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

F. Water Distribution System

1. Nozzles shall be precision molded ABS, large orifice spray nozzles utilizing fluidic technology for superior water distribution over the fill media. Nozzles shall be designed to minimize water distribution system maintenance. Spray header and branches shall be stainless steel with a steel connection to attach external piping.

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G. Heat Transfer Media

1. Fill media shall be constructed of Polyvinyl Chloride (PVC) of cross-fluted design and suitable for inlet water temperatures up to 130° F. The bonded block fill shall be bottom supported and suitable as an internal working platform. Fill shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

H. Air Inlet Louvers

1. The air inlet louver screens shall be constructed from UV inhibited Polyvinyl Chloride (PVC) and incorporate a framed interlocking design that allows for easy removal of louver screens for access to the entire basin area for maintenance. The louver screens shall have a minimum of two changes in air direction and shall be of a non-planar design to prevent splash-out and block direct sunlight & debris from entering the basin. Air inlet louvers shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

2.4 MOTORS AND DRIVES

A. Fan Motor

1. Fan motor(s) shall be totally enclosed, ball bearing type electric motor(s) suitable for moist air service. Motor(s) are Premium Efficient, Class F insulated, 1.15 service factor design. Inverter rated per NEMA MG1 Part 31.4.4.2 and suitable for variable torque applications and constant torque speed range with properly sized and adjusted variable frequency drives.

2. Fan motor(s) shall include strip-type space heaters with separate leads brought to the motor conduit box.

3. Provide VFD, manufacturer to be approved by NIST.

C. Fan Drive

1. The fan drive shall be multi-groove, solid back V-belt type with QD tapered bushings designed for 150% of the motor nameplate power. The belt material shall be neoprene reinforced with polyester cord and specifically designed for evaporative equipment service. Fan sheave shall be aluminum alloy construction. Belt adjustment shall be accomplished from the exterior of the unit.

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D. Fan Shaft

1. Fan shaft shall be solid, ground and polished steel. Exposed surface shall be coated with rust preventative.

E. Fan Shaft Bearings

1. Fan Shaft Bearings shall be heavy-duty, self-aligning ball type bearings with extended lubrication lines to grease fittings located on access door frame. Bearings shall be designed for a minimum L-10 life of 100,000 hours.

F. Vibration Switch

1. Unit shall be provided with a Vibration Cutout Switch, operating on 120 VAC feed, to protect the fan and drive assembly from damage in the event of excess vibration.

Vibration switch shall be DPDT.

2.5 MAINTENANCE ACCESS

A. Fan Section

1. Access door shall be hinged and located in the fan section for fan drive and water distribution system access.

B. Basin Section

1. Framed removable louver panels shall be on all four (4) sides of the unit for pan and sump access.

C. Internal Working Platform

1. Internal working platform shall provide easy access to the fans, belts, motors, sheaves, bearings, all mechanical equipment and complete water distribution system.

The fill shall be an acceptable means of accessing these components.

D. External Service Platform with Ladder

1. An external service platform compliant with OSHA shall be provided at the motor access door of the unit extending the full length of the access door. Each platform shall have at least a 36 in wide walking surface. The platforms shall have galvanized steel grating, supported by galvanized steel framework attached to the unit and surrounded by a handrail, knee rail and toe plate system that is compliant with OSHA.

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Mounting channels shall be the same material as the casing section (galvanized or stainless steel). A vertical ladder shall be provided from the base of the unit to the platform.

E. Motor Davit with Base

1. Unit shall be provided with mechanical external motor davit assembly which facilitates in removal of larger fan section components. Davit arm shall be constructed of aluminum and base shall be galvanized steel.

F. Louver Access Door

1. Hinged access door in louver shall be provided.

2.6 ACCESSORIES

A. Piping Connections

1. Unit shall include an oversized outlet connection for remote sump operation.

Suction hood and strainer assembly as well as make-up, overflow and drain connections shall be omitted.

2.7 NOMINAL CAPACITIES AND CHARACTERISTICS

A. Minimum total capacity: 6,000 Tons.

B. Air-Inlet Arrangement: sides

C. Waterside:

1. Design Water Flow:5,411 gpm.

2. Entering-Water Temperature: 85 deg F.

3. Leaving-Water Temperature: 75 deg F.

D. Airside:

1. Entering-Air, Wet-Bulb Temperature: 69 deg F

E. Accessories

1. IBC Standard Structural Design

2. 304 Stainless Steel Upper

3. Vibration Switch

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4. Ladder Extension; 4 Feet

5. Super Low Sound Fan

6. 1.0 Importance Factor Specified

7. Oversized Outlet for Remote Sump; ASA; 14"

8. Louver Access Door

9. Motor Davit with Base

10. Fan Motor: Space Heaters

11. 304 Welded Stainless Steel Cold Water Basin

12. External Service Platform with Ladder

13. Fan Motor: Inverter Capable, Premium Efficient

14. VFD

15. Factory Mutual Approved 16.

E. Accessories