Q & A > Question Details
Has there been a case in any Refineries where the backwash stream (post backwash) is routed back to the cold feed tank instead of slops. The idea is to minimize sloping and reprocess it.
 
Answers
17/11/2016 A: Sowmya Challa, Indian Oil Corp, challa.sowmya@gmail.com
Hi. In our Refinery DHDT filter back wash was initially routed to slop. Later we made two modifications, first routing it to our DHDT feed tank and later we routed to E3 Diesel product tank.
16/11/2016 A: RAMAKRISHNA DADI, HMEL, dadi2rama@gmail.com
we are facing a heavy solids in back wash filter and inside the shell and filter cartridge due to DCU to coming feed is coke.
our filter candles are 25 microns are SS 316 and shell body is CS material.
hi H2S is in the feed and cs material corroded due to galvanic corrosion and passing the coke to feed.
Recently we facing a back wash effluent and diesel routed to slope tank and the cooling water exchanger is tubes are totally corroded due to coke deposits are passing.
So we suggest every 3-4 months need isolate the each filter and remove the filter candles and clean the hydrojetting inside the filter shell is good.
07/11/2016 A: Krishna Nimesh, BPCL-Kochi Refinery, krishna.nimesh@gmail.com
I think nowadays it's a common practice in refineries to route back the backwash stream in feed tank after filtration. Put some cartridge filter, clean your backwashed feed and route back to feed tank rather than slop tank.
07/11/2016 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
If your backwash is on a timed cycle and you aren't seeing any signs of solids in the backwash, you might get away with routing the backwash back to the feed tank. I better approach would be to backwash as needed based on DP across the filter. In that case you will know there is a need to backwash and you would want to route the flow to slop.
If the backwash contains solids then you are going to start recycling solids to your filter and/or building up solids in your feed tank. Depending on the amount of solids this could cause you to have to take the feed tank out of service prematurely to clean out the solids. Recycling clean oil is OK. Recycling solids is not a good idea.