Cleaning Recirculation Pump

The recirculation pump is typically a centrifugal pump. It should be sized to handle the maximum recirculation rate for the largest stage in the RO skid. For example, given a 4 2-6M array, the recirculation pump must be able to deliver 45 gpm per pressure vessel or 180 gpm at less than 50 - 60 psig. 

The cartridge filter is typically a 5- to 10-micron nominal cutoff filter. The housing can be PVC, FRP, or SS. It should be equipped with a differential pressure gauge to measure the pressure drop across the filter. Cartridge filters should be changed out with every new cleaning solution. 

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With regard to operational considerations, the recirculation pump pressure gauges (which measure pressure differentials and consequently indicate possible blockage in the coiled tube) require frequent calibration. Regular cleaning and good housekeeping are also required, especially within the furnace area. 

The main outlet of the vessel should be at least 75 mm in diameter to allow for a fast flow of the prepolymer. The outlet can be connected either to a recirculating pump or directly to a filter prior to the drum filling. The pump must be capable of pumping the most viscous material quickly. Another key point to be noted when selecting a pump is that it has to have suitable glands. It also must be able to withstand the cleaning solvents and be readily stripped for clearing any buildup in the pump. 

Specific logistics for cleaning may vary depending on the type of fryer. For example, a direct-fired fryer with no oil recirculation will require more manual procedure compared with that with an oil recirculation pump because the pump can move the caustic solution through the entire system. Similarly, a kettle fryer will require manual scrubbing for sanitation, whereas a continuous potato chips fryer can use the recirculation pump to get the cleaning action. 

Body feed pumps work best if run continuously, recirculating back to body feed tank only when the filter is off-stream for cleaning. Piston pumps should have ceramic pistons, and flush-out connections on packings may be desirable. Outlets on single outlet diaphragm pumps should be at the bottom of the diaphragm chamber to prevent accumulation of filter aid in the chamber. 

The recirculation pump permits one to make a pass over the different elements to clean again. 

Reactor recirculation pump seal coolers Reactor recirculation pump motor coolers Nonregenerative cleanup heat exchanger Clean sump coolers Sample coolers Drywell coolers... 

A storage or immersion tank, acid-resistant recirculation pump, and associated piping and valving compatible with the acid solution are required as shown in Fig. 11-8. Common methods of applying acid cleaning agents used for cleaning metals are ... 

MF and UF systems can be designed to operate in various process configurations. A common configuration is one in which the feedwater is pumped with a cross-flow tangential to the membrane. The only pretreatment usually provided is a crude prescreening (usually 50 to 300 / m). The water that permeates the membrane is clean. The water that does not permeate is recirculated as concentrate and blended with additional feedwater just after the preliminary filter. To control the concentration of the solids in the recirculation loop, some of the concentrate is discharged at a specified rate. 

RECIRCULATION FROM PUMP DISCHARGE THROUGH AN ORIRCE (WHEN NECESSARY). TO A CYCLONE SEPARATOR DELIVERING THE CLEAN FLUID TO THE SEAL CHAMBER. THE SOUDS ARE DELIVERED TO THE PUMP SUCTION UNE. 

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