SLUDGE DESANDING BOOSTER FEED PUMP (PALM OIL MILL)

Dear Azhar

The sludge oil to the desanding system contains high amount of sand /dirt which causes the excessive wear and tear on the pump
You are operating at 3 bar pressure and the existing pump will need about 1600 rpm which is a bit high
to do the job
Ideally ,select a pump at can operate at about 1000 rpm
Material can be Nihard or rubber lined pumps

The system pressure is 3 bar ,the OEM or Supplier of the Equipemet or system could have design the system to
be about 1.5 bar , and this simplify the operation

Initially there was some problem during commissioning stage ,but it was not the pump problem
as reported

a) complaint from mill that if valve is fully opened the Overload Relay tripped
we checked and found that the Ampheres setting was too low .therefore trip
as valve opened fully, the BHP increased .The motor rating is more than sufficient and it is fuuny that
electrical chargeman did not reliase this and ampheres of overload not set correctly

b) when valve is not fully openned .the flow was reduced at feed inlet to Desander .and hence the pressure
of only 1.7 bar

Pressure = Quantity / Area

How to determine if it is pump problem or system problem

Very often ,Engineer's mindset is that .
" NOT PERFORMING .MUST BE THE PUMP SUPPLIER PROBLEM OR OR PUMP NO GOOD "

a) First check the pump condition . If the pump condition is in order ,next
You can do a shut off Test on the pump .if pressure can be achieved at shut off ,then you can
confirm that the pumps 100 % ok

b) Check pump performance curve .see if rating done correctly for pump installed
Example ,for this duty
capacity : 20 m3/hr at 30 M head
pump Model :OB 1 1/4
pump Speed : 1800 rpm

If this is in order ,than move on the system

a) checked inlet . for any obstruction by sand /dirt accumulated at tank bottom or inlet line
b) Checked motor maximum Amps and setting amps ( your initial setting was 18.4 amps for 11 kw motor , Star Delta connection , it was later set to 22 amps )

Job Done

The overload relay resetted and valve can be fully open .pressure achieved and running in
required parameter

The problem now is high  wear & tear , suggest resize a pump to operate at lower rpm and material compatible to this operation
Another pump OB 1 1/4 -33 , can operate same duty point at 1200 rpm ,  lower speed and hence lower
wear and tear