Preventing Emulsification - Best Pumps 2

[wardens355]

I am working on a project requiring pumps to transfer oily water to an oil water separator. What pump type provides the least amount of emulsification? Low RPM positive displacement seems ideal, but I'd like to get some feedback from people familiar with similar applications.

 

[bimr]

Pumping of wastewater with oil and grease is usually accomplished with low speed, low shear centrifugal pumps. These pumps operate at designed for lower speeds, 750 rpm is typical. Screw pumps made by Hidrostal, Leistritz and others work very well. Low speed postive displacement pumps such as progressive cavity pumps may also work.

 

[jardelviana]

You can think about Discflo, this pump is realy good for shear sensitive fluid. In the past I had this problem and only DISCFLO solve my problem.

 

[SNORGY]

jardelviana,

Thanks for the tip on DiscFlo pumps. It was initially counterintuitive (for me) to think of the DiscFlo pump as a low shear pump, but maybe it's exactly what I need in an application I have here at work. I need a treater feed pump to do about 40 m^3/hr @ 60 m head, pumping a 3:1 emulsion with water and 21-API oil. Up until now I have been thinking of a progressive cavity pump. I'll look into DiscFlo some more.

 

[ApplicationENG]

Goulds Pumps also make an AF (Axial Flow pump) is it low speed and Nss (pretty much a propeller). I have worked with them for emulsifications and chelants/chelator both of which a shear sensitive.

These pumps were used as "mixers"/"circulators". They are cost competitve, engineered and can be quick turnover pieces of equipment.

 

[DubMac]

As long as your flow is not too high (say over 100-200gpm), a Progressive Cavity is the best pump for non-shearing, and will easily handle any entrained solids w/o wear concerns. Look at Moyno, Netzsch, Monoflo, e.g.

 

[wardens355]

I am looking at the 400-600 gpm range. A previous project used a rotary lobe pump at about 250 rpm for this flow range. An article I uncovered online indicated that disc pumps performed the best in terms of preventing emulsification. Seems like everyone has their own flavor for this.

 

[bimr]

You seem to have skipped over the screw pump. Most skimmers use screw pumps because the pumps will not form an emulsion, are tolerant of debris, do not require priming, and will handle viscous oil.

The screw / centrifugal impeller with its open channel impeller design combines the gentle action of a screw pump and the high flow rates and cost efficiencies of a centrifugal pump.

http://www.environmental-expert.com/products/triton-screw-centrifugal-pumps-148204

http://www.hidrostal.co.uk/default.aspx?p=screwce