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Figure   2-65.   R.O.   Pump   High   Pressure   Lamp
Figure  2-67.  Mechanical  Timer

TM-10-4610-215-10 Water Purification Unit Reverse Osmosis 600 GPH Trailer Mounted Flatbed Cargo 5 Ton 4 Wheel Tandem Rowpu Model 600-1 Manual
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TM    10-4610-215-10 TM   08580A-10/1 2-26. BACKWASH  OF  MULTIMEDIA  FILTER. NOTE The multimedia filter should be backwashes: After  20  hours  of  ROWPU  operation,  or Multimedia filter gage reading is over 10 psid, or Multimedia filter gage reading exceeds 5 psid of log reading at startup, or ROWPU  is  to  be  shut  down. a. General. The backwash cycle is an up-flow operation. Water flows from the bottom to the top of the tank and then out to drain through the backwash flow control, washing out turbidity and settling the filter bed. The filter has three separate backwash stages. The first stage of backwash is at 70 gpm to fluidize the bed. A second backwash stage begins at approximately 120 gpm, tumbles at the bed, and scours the particles against one another when the backwash diaphragm valve opens. The backwash diaphragm valve then closes, returning the backwash rate to 70 gpm to restratify the media bed. The rinse cycle is a down flow operation. Water flows from the top of the tank through the filter bed and out to drain. This displaces the backwash water in the tank, and preconditions the filter bed before the filter reaches the purge cycle. The purge cycle is rapid downflow rinse to remove turbidity from the bottom of the filter and recondition the filter bed prior to the return to service. b. Backwash Timer and Multimedia Filter Control Valve (fig. 2–15). The direction and rate of water flow through the multimedia filter are controlled by the control valve and backwash diaphragm valve. The control valve consists of six diaphragms which open and close during the timer cycles of backwash, conditioned rinse, and service (service means normal ROWPU operation). As the backwash timer automatically changes cycles, its pilot valve changes position. When the backwash timer pilot valve changes position, it hydraulically closes and opens the diaphragms in the control valve. During the 120 gpm portion of the backwash cycle (referred to as “secondary  backwash”)  the  backwash  timer  solenoid  valve  sends  water  to  the  backwash  diaphragm  valve (located just under the control valve). This opens the backwash diaphragm valve, resulting in the higher rate of backwash  water  flow. (1)  Mechanical  Timer  (Model  600-1):  The  main  components  of  the  mechanical  timer  are  the reconditioning knob, timer mechanism motor, four controller cams, pilot valve motor, white cam, and the auxiliary pilot switch. The reconditioning cycle, backwash, rinse, purge, and service operation begins when the backwash switch, located on the control panel, is manually placed in the ON position. The recharge lever solenoid in the timer is then energized and the level moves to the right, thus rotating the reconditioning knob. There is now a dead time from 2–5 minutes (the time is still running) before backwash begins. The timer motor drives the controller cams (4 cams). These cams, which are set at the factory, control the reconditioning cycle. Readjustment should not be required. Backwash is initiated when the micro switch for the bottom cam (black cam with numbers) falls in the cam slot. When the blade of the micro switch falls into the notch of the fourth cam, the white cam is in the service (SR) position. The pilot valve motor receives signals from the white cam. The pilot valve sends water to pressurize (close) control valve, or drains water (opens). The auxiliary pilot switch is used to start toe backwash pump. The switch is operated by activation of its lever arm by the raised button on the white controller arm. (a)  Open  timer  cover. 2-70







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