Operating instructions

OPERATING INSTRUCTIONS
4-20 30 Sep 13
DE-7200VFDCentrifuge
CLEAN OUT (CONT’D)
Figure 4-20. Clean Out Screen
Provision is included for selecting the automatic or manual cleanout options. When the cleanout
process has timed out or was stopped by the operator, the Operation screen or the Faults screen
may be displayed.
If automatic reduction of the pump speed is unable to clear out solids from the conveyor, the
torque will continue to rise and the centrifuge will shut down. The clean out procedure should then
be used to clear out the impacted solids and return the centrifuge to operational status. The
following paragraphs explain the two cleanout options: automatic and manual.
Automatic Cleanout
When the automatic option is selected, the system will perform a cleanout cycle for a pre-set
duration. The bowl operates at 300 RPM, while the conveyor operates in the forward direction at a
speed that varies from 8 to 30 RPM. If excessive resistance is encountered during the cleanout,
the system will stop and alert the operator that the automatic cleanout has been unable to clear
the centrifuge. Operator intervention is then required to repeat the automatic cleanout operation.
Manual Cleanout
Note!
The manual cleanout should be used only if multiple automatic cleanout
attempts are unsuccessful.
When the manual cleanout option is selected, the operator may elect to jog the conveyor in
forward and reverse with the bowl set at zero RPM. If desired, however, the operator may choose
to operate the bowl as well as the conveyor. Reverse rotation of the conveyor is governed by a
timer that terminates reverse operation after a pre-set interval. The primary purpose of the manual
cleanout mode is to permit jogging the conveyor in an effort to remove impacted material.