UFC 3-280-03
23 JULY 2003
press operator has manual control over or override control over several functions of the
filtration cycle. It is also assumed that this system is equipped with a variable flow
rate/pressure feed pumping system, a filter media precoat system, a core and air blow-
ing manifold system, and both water and acid wash filter media systems. The typical
operation sequence is as follows.
2-9.5.1.1 The closure (i.e., hydraulic or electromechanical) device is engaged, closing
all the chambers of the press.
2-9.5.1.2 The press is prefilled with water, and the filter media precoat system is
engaged. The precoat cycle is then allowed to operate for a minimum of three passes.
2-9.5.1.3 Following the precoat cycle, while a constant pressure is maintained within
the press, the sludge feed pump system is started and allowed to fill the press at the
specified high flow rate and low pressure.
2-9.5.1.4 After the initial fill period is completed, the pumping system flow rates and
pressures should be inversely stepped or adjusted (e.g., flow rate should be decreased
and pressure should be increased) until the terminal pressure, minimal filtrate flow, or
cycle time is achieved.
2-9.5.1.5 After the filtration cycle is completed, the feed pump system should be shut
off, and compressed air should be blown through the feed core and filtrate manifold to
remove any remaining liquids.
2-9.5.1.6 The closure device is then opened, and plate shifting and sludge cake dis-
charge is initiated.
2-9.5.1.7 Following sludge cake removal, and as required, the plate and filter media
water wash operation is initiated. The water wash consists of the following sequence:
Start the wash water pumping system.
Open the filter press.
Shift and wash one plate at a time.
After the last plate has been washed, turn off the wash water pumping sys-
tem.
After completing the water wash, and as required, the filter media are washed in acid.
The acid wash consists of the following sequence:
Close the press and ensure all valves not related to the acid wash system are
in the closed position.
Open the outlet valve to the acid recirculation tank and the valve to the acid
feed pump system.
Start the acid feed pump and allow the chambers of the press to fill. Allow the
pump to continue to run and recirculate the acid while occasionally inspecting
the press for leakage.
2-83
Previous Page
