Automatic Backflushing System (ABS)
General Specification
General:
An Automatic Backflushing System (ABS) shall be supplied as an integral part of each plate and frame heat exchanger to maintain optimum heat transfer surface cleanliness. The ABS shall be manufactured by Water Technology of Pensacola, Inc.
Product Description:
The ABS automatically maintains clean heat transfer surfaces without interrupting normal equipment operation.
The ABS system consists of an integrally mounted 4-way reversing valve that permits the reversing of the direction of water flow in the heat exchanger. This flow reversal has been found to significantly reduce fouling in the plate and frame heat exchanger. A control panel mounted to the plate and frame heat exchanger/chiller or at a separate location as desired controls the flow reversal. The frequency of flow reversal is set up to match job conditions. Normally, flow reversal would occur once every six to eight hours.
Equipment Specification:
Four-Way Valve: Valve shall be per Water Technology's standard HX or CX configuration and shall be of steel construction (A36 or better), positive sealing type with all internal sealing parts of hard rubber and 304 stainless steel. It shall be manufactured in accordance with ASME Unfired Pressure Vessel Code Specification per Section VIII for operation at a system working pressure of 125 PSIG (or as specified) with a maximum system differential of 35 PSIG. The valve will be mounted as an integral part of the plate and frame heat exchanger. It shall be hydrostatically tested to 1.5 times designed working pressure. Valve shall allow for manual fail-safe turning, and have a mechanical position indicator.
Pneumatic Actuator: To be pre-mounted on the valve. Double actuating cylinder to assure trouble-free operation. Actuator operation to be on 50 to 100 PSIG air pressure supplied by the customer.
Position Control Switches: Micro-switch to be supplied for the valve to indicate a complete turn of the valve in normal and reverse flow.
Control Panel: The on-load control shall have the following features:
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NEMA 4x enclosure with mounting bracket.
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Cycle counter.
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24-hour timer to automatically initiate the on-load cleaning cycle.
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Manual Override of the pre-set cleaning cycle.
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Power On light.
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Diverter Position Indicator lights:
-Normal Flow
-Reverse Flow
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Malfunction Light - To indicate slow-turning or incomplete valve turning.
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4-way solenoid valve for actuator operation to be mounted at control panel or actuator.
OPTIONAL
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Electric Unloading Feature.
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Flow Switch Bypass.
Operation and Installation Manual: Two (2) copies to be provided.
Shop Testing: In addition to tests specified for the valve, Manufacturer will functionally test the entire system prior to shipment including valve, actuator and control panel.
Field Service and Replacement Parts: Manufacturer will maintain at all times an adequate inventory of replacement parts that are available for immediate shipment. Qualified field service personnel shall be available from the manufacturer (at an added cost) on short notice to service or repair equipment furnished.
Manufacturer: The ABS System is manufactured exclusively by:
Water Technology of Pensacola, Inc.
3000 West Nine Mile Road
Pensacola, Florida 32534
TEL: 850-477-4789
FAX: 850-479-3056