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piolenc
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Pump Design for Multi-Mode Operation

03/29/2010 9:35 AM

I'm trying to simplify and cheapen the design of some food processing gear by combining two pumps into one. The two requirements are high pressure (1500 psi), low flow and low pressure, high flow at about the same total horsepower. Is there a pump design, either manual or power-driven, that can accomodate both modes of operation? The innards of the pump have to be sterilizable.
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mike k
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#1

Re: Pump Design for Multi-Mode Operation

03/29/2010 11:32 PM

There's not too many pumps that can get 1500 psi, my favorite is the vane type. Even rotated slowly, it will pump. You could hook it up to a planetary drive to get different speeds. Have fun cleaning it.

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piolenc
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#2
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Re: Pump Design for Multi-Mode Operation

03/30/2010 12:16 AM

"There's not too many pumps that can get 1500 psi, my favorite is the vane type. Even rotated slowly, it will pump. You could hook it up to a planetary drive to get different speeds. Have fun cleaning it."

You know, that isn't a bad idea. I hadn't considered vane pumps, but I believe the modern ones are dry-film lubricated, so there's no lubricant to contaminate the pumped liquid and the sterilant solution should not cause trouble with lubrication. I believe they can even be made self-priming, though that is not a requirement here. And a two-speed planetary gearset makes good sense.

This is a very helpful response, and I am grateful that you took the time to make it.
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yesyen
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#3
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Re: Pump Design for Multi-Mode Operation

03/30/2010 1:16 AM

If you think mike k has helped by his response, why don't you give him a GA?

Its really a good answer...

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piolenc
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#4
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Re: Pump Design for Multi-Mode Operation

03/30/2010 10:03 AM

"If you think mike k has helped by his response, why don't you give him a GA?

Its really a good answer..."

Because I'm new to the forum. I've now done as you suggested.
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coffeebean
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#5

Re: Pump Design for Multi-Mode Operation

03/30/2010 10:21 AM

A piston pump is best suited to your requirements. I doubt that a vane pump will do it for you. Probably a piston pump is best suited to your requirements, which aren´t easy. Look for homogenizers in the second-hand market and see how far your budget takes you as they are not cheap.
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Anonymous Poster
#6

Re: Pump Design for Multi-Mode Operation

03/30/2010 10:41 AM

To answer your question. There is not one pump that will do both jobs.

The conditions are:

1. High pressure, low flow and

2. Low pressure , high flow.

Even if both pumps are about the same horsepower the conditions are vastly different.

Graph the two conditions with gpm on the x axis and pressure [or head] on the y axis.

The first condition will be in the upper left of the graph and the second condition will be in the lower right of the graph no single pump can meet both conditions.

You can't beat the physics of it. Stay with two pumps that operate at peak efficiency for the conditions.

Charlie
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yesyen
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#7
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Re: Pump Design for Multi-Mode Operation

03/31/2010 12:12 AM

The conditions are:

1. High pressure, low flow and

2. Low pressure , high flow.

This why mike k suggested variable speed drive arrangement. Low speed can be lined graph with, 'High pressure, low flow' and high speed can be lined up with, 'Low pressure , high flow'. If 'speed' is also included in the graph, I think it might fit-in.

Any (suitable) positive displacement pump with variable drive can be considered.

Suitable in sense, 'will the pump under consideration works at these extreme speeds?'

Cleaning the internals, is another requirement, right?

There are gear pumps with superior food grade polymer gears, separated from conventional (steel) driving timing gears, in all two sets of gears. The specific advantage would be, the pumping gears would maintain a non-contact, so contamination free.

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Anonymous Poster
#8

Re: Pump Design for Multi-Mode Operation

04/01/2010 7:42 AM

Axial Piston Pumps used in heavy machinery, with hydraulic systems have what is called a "swash" plate. This swash plate angles itself to allow greater flow and lower pressure or low flow, high pressure. This especially useful when hydraulic pistons have to work against a high force (at lower speeds) and then retract quickly (against low pressure)

http://www.tpub.com/fluid/ch1s.htm
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Anonymous Poster (2); coffeebean (1); mike k (1); piolenc (2); yesyen (2)

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