G._Purchase_Description.pdf

Purchase Description

Fluid Cooler

1.0 Base:

1.1 Provide 2 each induced-draft, crossflow-type, factory assembled, stainless steel, closed circuit fluid coolers. The coolers shall each have a maximum footprint of 100 in. wide by 75 in. long, and have a maximum height of 156 in. The total operating horsepower of any fan shall not exceed 3 Hp.

1.2 The closed circuit fluid cooler shall be designed for quiet operation, and shall produce an overall level of sound not higher than 66 dB(A) measured at a distance of 5 ft. from cased face. Sound levels shall be measured with a Type 1 (precision) system and in full conformance with ATC-128 test code published by the Cooling Technology Institute (CTI). The measurement system shall have a real-time frequency analyzer and separate microphones with an overall tolerance +/- 3 dB. All low sound options shall be CTI Certified for thermal performance.

2.0 Thermal Performance:

2.1 The fluid cooler shall be capable of cooling 118 gpm of 50.0 % by volume ethylene glycol water solution from 116 °F to 96 °F at a design entering air wet-bulb temperature of 78 °F. Coil pressure drop shall not exceed 4 psi. The thermal performance rating shall be certified by the Cooling Technology Institute.

2.2 The closed circuit cooling fluid cooler shall be capable of a minimum of 36 gpm/Hp efficiency per ASHRAE Standard 90.1.

3.0 Performance Warranty:

3.1 CTI Certification notwithstanding, the fluid cooler manufacturer shall guarantee that the fluid cooler supplied will meet the specified performance conditions when the fluid cooler is installed according to plans. If, because of a suspected thermal performance deficiency, the owner chooses to conduct an on-site thermal performance test under the supervision of a qualified, disinterested third party in accordance with CTI or ASME standards during the first year of operation; and if the fluid cooler fails to perform within the limits of test tolerance; then the fluid cooler manufacturer will pay for the cost of the test and will make such corrections as are appropriate and agreeable to the owner to compensate for the performance deficiency.

4.0 Coil:

4.1 Coil(s) shall consist of Corrosion resistant copper tube bundle(s). Copper bundles pressure tested to 350 psi; max operating design pressure of 300 psi. The coil(s) shall be designed for free drainages of fluid at shutdown. Coil(s) shall be warranted against any failure caused by defects in materials and workmanship for a period of eighteen (18) months from the date of shipment.

5.0 Design Loading:

5.1 The structure and anchorage shall be designed to withstand a wind load of 30 psf while operating. The fluid cooler shall be designed to withstand shipping and hoisting loads of 2g horizontal or 3g vertical. The fan deck and water basin covers shall be designed for 50 psf live load or a 200 lb concentrated load. Guardrails, where specified, shall be capable of withstanding a 200 lb concentrated live load in any direction, and shall be designed in accordance with OSHA guidelines.

6.0 Construction:

6.1 Except where otherwise specified, all components of the fluid cooler shall be fabricated of heavy-gauge, 301L stainless steel. Only low-carbon stainless steel alloys will be accepted in order to minimize the risk of intergranular corrosion in the weld zones. The fluid cooler shall be capable of withstanding water having a chloride content (NaCl) of up to 750 ppm; a sulfate content (SO4) up to 1200 ppm; a calcium content (CaCO3) up to 800 ppm; silica (SiO2) up to 150 ppm. The circulating water shall contain no oil, grease, fatty acids, or organic solvents.

6.2 Each fluid cooler shall be equipped with a UL / CUL 508 listed control panel in a NEMA 3R outdoor enclosure designed specifically for fluid cooler applications. The panel shall include a main thermal magnetic circuit breaker disconnect with an external operating handle, lockable in the off position for safety. For fan operation use a full voltage non-reversing magnetic starter controlled with a solid-state temperature controller. For spray pump operation use a full voltage non-reversing magnetic starter with manual ON and OFF control via a door mounted selector switch. The solid-state device for fan control will display two temperatures, one for outgoing water and the other for set point temperature. Water temperature input shall be obtained using a three-wire RTD with dry well located in the field outlet water piping. Dry status contacts wired to user terminal points indicating typical alarm and status events shall be provided. Two safety circuits for the spray pump, low water cut off preventing a dry run pump and a pump shut down upon approaching freezing temperatures in the cold water basin shall be provided. Additional features to include: Water level control with make-up, high alarm, low alarm, high cut off and low cutoff events. Basin heater controller with low-water cutout.

7.0 Mechanical Equipment:

7.1 Fan(s) shall be high efficiency low sound design, driven through a one-piece multi-groove, solid back V-type belt. Bearings and fan shaft shall be contained in a cast-steel housing to insure proper fan shaft alignment, pillow block bearings are not allowed. Bearings shall be rated at an L10A service life of 90,000 hours or greater.

7.2 Fan motor(s) shall be 3 Hp maximum, NEMA Premium Efficiency TEFC, 1.15 service factor, two speed one winding motor and specially insulated for cooling fluid cooler duty (Class F). Speed and electrical characteristics shall be 3 phase, 60 hertz, 480 volts. Nameplate power shall not be exceeded at design operation. TEAO motors shall not be acceptable.

7.3 The fan and fan drive assembly for each cell shall be supported by a rigid, structural support that resists misalignment. The mechanical equipment assembly shall be warranted against any failure caused by defects in materials and workmanship for no less than five (5) years following the date of fluid cooler shipment. This warranty shall cover the fan(s), premium efficiency motor(s), geared speed reducer(s), drive shaft(s) and couplings, and the mechanical equipment support. Bearing assemblies and V-belts shall be warranted for 18 months.

8.0 Fill, Louvers and Drift Eliminators:

8.1 Fill shall be film-type, thermoformed of heavy duty PVC, with louvers and eliminators formed integrally in each fill sheet.

The air inlet face(s) of the fluid cooler shall be free of water splash out.

8.2 Coil air-inlet louvers shall be heavy duty 17 mil PVC with a minimum of 5.75" of air travel. Louvers shall be triple-pass to limit water splash out and prevent direct sunlight from entering the collection basin. PVC louvers shall be easily removable for access to the coil(s). Louvers with less than three changes in air direction are not allowed.

8.3 Drift eliminators shall be heavy duty 17 mil PVC with a minimum of 5.75” of air travel and a minimum of three changes in air direction. Drift eliminators shall limit drift losses to 0.005% or less of the design recirculating water flow rate.

9.0 Distribution Basins:

9.1 An open 301L stainless steel basin above the fill with removable interchangeable polypropylene nozzles installed in the floor of the basin shall provide full coverage of the fill by gravity flow. The basin components shall be installed and sealed at the factory and connected with bolted connections. Tap screws shall not be allowed. The basin shall be equipped with removable, stainless steel covers capable of withstanding the loads described in paragraph 5.1. The water distribution system shall be accessible and maintainable during tower fan and water operation.

10.0 Access:

11.1 Access doors shall be a minimum of 24" wide and 42" tall and shall be operable from inside as well as outside of the fluid cooler.

11.2 Provide external maintenance platform(s) constructed of heavy gauge galvanized steel with safety grip perforations, supported by galvanized steel framework attached to the fluid coolers. The platform shall be surrounded by an OSHA compliant guardrail system welded into subassemblies for ease of installation. Provide a permanently attached ladder to access the maintenance platform.

11.5 Provide a factory-installed, heavy gauge steel walkway with safety grip perforations, for interior maintenance.

11.0 Collection Basin:

12.1 The collection basin shall be welded 301L stainless steel construction. Only low-carbon stainless steel alloys will be accepted in order to minimize the risk of intergranular corrosion in the weld zones. Suction connections shall be equipped with stainless steel debris screens. All steel items which project into the basin (coil supports, anchor clips, etc) shall also be made of stainless steel. A factory-installed, float-operated, mechanical makeup valve and wastewater blowdown line shall be included.

An overflow and drain connection shall be provided in each cell of the fluid cooler. The basin shall include a depressed section into which accumulated particle debris can be flushed to permit cleaning. The basin floor adjacent to the depressed section shall slope toward the depressed section to prevent buildup of debris under the coil area.

12.2 Recirculation pump(s) shall be mounted to the collection basin in conjunction with a suction assembly. Recirculation piping shall be schedule 40 PVC. A blowdown line with metering valve shall be connected directly to the fluid cooler overflow.

12.3 Provide a system of electric immersion heaters and controls for each cell of the fluid cooler to prevent freezing of water in the collection basin during periods of shutdown. The system shall consist of one or more stainless steel electric immersion heaters installed in threaded couplings provided in the side of the basin. A NEMA 4 enclosure shall house a magnetic contactor to energize heaters; a transformer to provide 24-volt control circuit power; and a solid-state circuit board for temperature and low water cut-off. A control probe shall be located in the basin to monitor water level and temperature. Recirculating pump(s) shall be fitted with heat trace cable and insulated. The system shall be capable of maintaining 40°F water temperature at an ambient air temperature of -10 °F.

12.0 Warranty

13.1 The fluid cooler shall be free from defects in materials and workmanship for a period of eighteen (18) months from the date of shipment.

13.0 Definitions

" Inches ‘ Feet CTI Cooling Technology Institute CUL Underwriters’ Laboratories of Canada dB Decibels dB(A) A-weighted decibels ft Feet g Gravity gpm Gallons Per Minute Hp Horse Power lb Pound mil Thousandth of an Inch NEMA National Electrical Manufacturers Association OSHA Occupational Safety and Health Administration Pa Pascal ppm Parts Per Million psf Pound per Square Foot psi Pound per Square Inch PVC PolyVinyl Chloride RPM Revolutions Per Minute RTD Resistance Temperature Detector TEAO Totally Enclosed Air Over TEFC Totally Enclosed, Fan Cooled UL Underwriters Laboratories