9 replies to this topic

[Araboni]

dear all

I have a latex (XSBR) with max viscosity of 600 mPa.s. Please let me know if I can use centrifugal pump to transfer it.

Generally speaking , Is there any rule of thumb restricting the max permissible viscosity of fluids in case of centrifugal pumps?

Edited by Araboni, 02 October 2013 - 06:13 AM.

[latexman]

At > 50 cP centrifugal pumps show an increase in brake horsepower, a reduction in head, and some reduction in capacity.

 

 

The general rule of thumb I use is 1000 cP is about the max. even with making smart design choices, like impeller type, speed, seal options, etc.  What about others?

[fallah]

Arobani,

 

As far as i know, centrifugal pumps can be able to transfer the fluids with the viscosity of as much as 700 cS and lower. This limitation value can be increased up to 1000 cS using special designed impeller.

 

In fact, for the fluids more viscous than water there are the curves by which the correction factors (for flow, efficiency and head) can be found using them the corresponding flow, head and efficiency based on water are to be calculated. Then the customer can select the proper pump inside vendor catalugue in which the pumps are normally presented based on transferring the water.

[breizh]

Araboni,

 

Consider a diaphragm pump for this type of application

 

http://www.marcopump...II_Complete.pdf

 

In all the places  I've been working , producing water based emulsion,we were using diaphragm pumps to transfer the material  because  the viscosity is one of the key specification which can be modified heavily by using  centrifugal pumps .

 

Just my experience.

 

Breizh

Edited by breizh, 05 October 2013 - 06:49 AM.

[GTYJ81]

As a general "rule of thumb", I have always used 300 cP as the limit for centrifugal pumps.  Although centrifugal pumps can be used with fluids of higher viscosities, they become very inefficient above the 300 cP threshold.

[latexman]

Araboni,

 

Is that 600 cP as determined in the lab at a low controlled temperature and a somewhat low shear rate?  Most synthetic latexes are shear thinning, and the apparent viscosity at process temperature and at the shear rate imparted by the centrifugal pump, may be significantly lower than 600 cP.

[Araboni]

Latexman

As you may be familiar with, the pertinent latex is carboxylated styrene butadiene rubber and its viscosity at zero shear is about 400-600 cP depending on the solid content of latex.

[latexman]

Do you know the product's rheology?  What is the apparent viscosity at process T and shear rate in the pump?  THAT viscosity is the one that counts on how it will pump.

[Araboni]

Latexman

during the pumping of latex , its viscosity is about 250-300 cP.

[latexman]

To answer your first question, if the latex has good shear stability, yes, you can use a centrifugal pump.