Pumping Grease and Water

[WastewaterMan]

I am dealing with a pumping situation where I need to be able to tell when the pumped liquid has changed from grease to water. I have a couple of ideas already like a thermal mass sensor or a conductivity meter but I'm primarily concerned about equipment fouling. I've also thought about doing something on the storage side but that won't help if I get ratholing. Does anyone have any suggestions or has anyone run across this before? Thanks so much.

 

[MikeHalloran]

The change should show up in the pump power, and be reflected in motor current.

Mike Halloran
Pembroke Pines, FL, USA

 

[WastewaterMan]

Thanks, I had thought about that too. With all the built up material that may exist in the line I'd be concerned about false triggers (e.g. a slug of material breaking loose and changing the pumping conditions). That being said, this is still on the table.

 

[bimr]

You need to supply some details. For example:

What is the grease? The temperature? Liquid or solid grease? Indoors or outdoors? Why are you pumping these materials? Is this a waste or a process application? Capacity? How far are you trying to pump?

 

[WastewaterMan]

Grease will be almost entirely food based waste. Mostly liquid some solids. Raw grease will be going into a tank which will be heated to help promote grease separation and to eliminate the chunkies. From there the grease will be sent to a holding tank and then to a digestor. The water will go to a separate process. Looking to pump with a progressive cavity pump no more than a few hundred feet of horizontal separation and probably 10-15 feet of static lift. I don't have all of the numbers yet but grease trap waste for the region works out to be about 1.4 million pounds a year. If worse comes to worst, I can always just pump down to a certain level and not get all of the water with each run.

 

[bimr]

Most food wastes contain FOG and DAF units are used to separate the FOG from the water. You probably will have to use heat to keep the grease in solution.

 

[gerhardl]

Is someone looking into minimizing the fat input to the system at origin?

Economical it would seem sensible too look into this instead, or parallell, to put in equipment that seems to end up with considerable heating and separating costs 'downstream'.

 

[dicksewerrat]

You could also install an injection pump to put emulsifier into the system close to the point of origin of the grease.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com