15 Belt Press Start Up

The dewatering system is turned off by the swing shift operators before the end of their shift. The systems are turned back on in the morning when the day shift arrives. Start Up of the Belt Filter Press depends on how much room is in the holding tank.  For example: if there is 50” of volume remaining in the Sludge Holding Tank, BFP operation may be delayed until noon.  If there is 12 of volume remaining in the Sludge Holding Tank, BFP operation would begin as soon as possible.

One BFP is in operation while the other is on standby.  The lead and standby BFPs are rotated every month.

1.     Prepare cake discharge.

a.     Verify that dump truck is parked in the sludge bay.

b.     Verify that cake hopper {tag no. 1506VLV5791} is open.  Cake hopper may be closed from the previous night’s shut down procedure.

2.     Switch Polymer Pump Feed Valve

The polymer pump feed valves should only be changed during the monthly BFP rotation.

a.     Locate the valves {tag nos. 1507VLV5300 & 1507VLV5400} on the suction side of the Polymer Pumps. The valves are located between the Polymer Day Tank {tag no. 1507TNK5693} and the pumps {tag nos. 1507PMP5300 & 1507PMP5400}.

                  i.    The valve for the polymer pump that is rotating into operation will be closed.  Open that valve {tag nos. 1507VLV5300 & 1507VLV5400}.

                 ii.    Close the valve {tag nos. 1507VLV5300 & 1507VLV5400} of the polymer pump that is being rotated to out of service.

3.     Serpentix Conveyor System Lubricant.

a.     Verify that the Serpentix Conveyor lubricant container has oil and the switch is toggled open to deliver lubricant to the conveyor.  If the oil container is empty or low on lubricant, add Shell Oil Tellus 32.  The lubricant container is located west of Belt Filter Press #1 and ground level at the end of the Serpentix.    

4.     Open Belt Filter Press Sludge Drain Valve.

a.     Open BFP Drain Line valve {tag no. 1506VLV5181B & 1506VLV5182B}.

5.     Start Serpentix Conveyor System {tag no. 1506CVY/MTR5943}.

a.     Locate the Serpentix Conveyor E-Stop button {tag no. 1506HS5943D}.  The E-Stop button is located “upstairs” on the filter press control panel platform.

                  i.    Push the E-Stop button to stop the conveyor.

                 ii.    Push the Start button {tag no. 1506HS5943A} to restart the Serpentix Conveyor.  The BFPs will not start unless the Serpentix Conveyor is in operation.

6.     Start Wash Water System.
Typically, Wash Water Pump #1 is in operation when BFP #1 is in operation, and Wash Water Pump #2 is in operation when BFP #2 is in operation. Control defaults are set up for that scenario. The wash water flow control valves should only be changed during the monthly BFP rotation.

a.     If time for the monthly BFP rotation, perform steps 6.b and 6.c.  If it is mid-month and there is no change to the BFP operation, perform step 6.c.

b.     Open and close the wash water flow control valves {tag nos. 1506VLV5991, 1506VLV5991A & 1506VLV5992, 1506VLV5992A}. These valves are located adjacent to the pumps.

c.     Locate the Serpentix Conveyor washdown recycle water valve {tag no. 1603VLV6282C} and open.  This valve is closed by the night shift when the BFP is turned off. This valve is located on the wall next to the BFP #2 Local Control Panels.

7.     Start Belt Filter Press {tag nos. 1506BPR5981 & 1506BPR5982}.

a.     Locate the Belt Filter Press Central Control Panel {tag nos. 1506CCP5981 & 1506CCP5982} associated with the BFP unit to be put into operation.

b.     Verify the Auger System {tag nos. 1506AUG5941 & 1506AUG5942} HOA Switch {tag nos. 1506HS5941 & 1506HS5942} is in the AUTO position. The Auger System is typically in AUTO.  The Belt Filter Press will not start it the Auger System is not in AUTO.

c.     Verify that BFP Paddle Pressure and Cloth Tension Pins {tag no. 1506VLV5100A, 1506VLV5100B & 1506VLV5200A, 1506VLV5200B} are in their proper positions to extend the hydraulic rams for operation.  Pins are located on the “upstairs”, east side of the BFP under the pressure gauges {tag no. 1506PI5100, 1506PI5100A & 150PI5200, 1506PI5200A}. Pins should be pushed in and the rams should be extended.  If the pins are pulled out, there will be no hydraulic pressure which will result in a low hydraulic pressure failure of the BFP.  Pins may be left in or left out from the previous night’s shutdown process.

d.   Make sure doctor blades are down and are scraping the sludge from the belt. The doctor blades are typically left in the up position when the filter is shut down for the night.

e.     Drop all chicanes on the upper horizontal belt.

f.     Turn the BFP HOA Switch {tag nos. 1506HS5981B & 1506HS5982B} to Auto position.

g.      Press the AUTO START button {tag nos. 1506HS5981D & 1506HS5982D}. The PLC will now begin the Automatic Start Up Sequence for that BFP unit.

h.     Turn the Dewatering Switch {tag nos. 1506HS5981G & 1506HS5982G} to the ON position.  The BFP will automatically start after the Auto Start Up Sequence is complete AND the Dewatering Switch is turned to ON.  If the Dewatering Switch is in the OFF position, the BFP will not automatically start at the completion of the Auto Start Up Sequence.

i.     Polymer Pump {tag nos. 1507PMP5300 & 1507PMP5400} speed is displayed at control panel indicator screen {tag no. 1507SI5312 & 1507SI5412}.  Adjust speed and pump selection, if necessary.

j.      The Sludge Transfer Pump {tag nos. 1505PMP5500 & 1505PMP5600} speed is displayed at the indicator screen {1505SI5536B}. Adjust the feed rate, if necessary.

k.      All other systems associated with the Belt Filter Press will start automatically and do not require further adjustment.

8.     Close Belt Filter Press Sludge Drain Valve.

a.     Observe consistency of sludge in the drain sump.  Once the sludge appears to be thickening, close the Belt Press Drain Line valve {tag nos. 1506VLV5181B & 1506VLV5182B}. This drain valve is typically left closed while the belt filter press is in operation.

9.     Observe operation of Belt Press Filter.

a.     Observe influent sludge and belt press operation.

b.     Check auxiliary equipment.

c.     Verify that sludge is flocculating well at the inlet to gravity section and forms windrows approximately 2/3 of the distance to the discharge chute. Sludge should form furrows by the 3rd and 6th chicanes.  If sludge is watery and not flocculating properly, go to steps 9.F and 9.G.

d.     Ensure that sludge is not squeezing out side of pressure belts.

e.     Modify sludge retention if necessary by rotating blade.

f.     Adjust polymer feed rate, belt speed, belt tension and necessary.

g.     Report unusual conditions to the supervisor.

h.      Visually check the belt cake discharge for low moisture.

i.      Check dump truck levels periodically and empty when necessary.