Novel Use for Fuel Injection Pump

It sounds as though a gear pump of some sort would do the job. Here's a picture of the innerds of one:

Gear pumps are positive displacement and the flowrate is closely related to the rotation speed. Any excess pressure at the delivery end of the pump can be returned to the inlet reservior via a pressure relief valve and a spill-back pipe.

'Owzat (a Cricket term, for the uninitiated)?

Hi PWSlack,

Thanks for the quick response.

We have tried a gear pump already, and cavitation is an issue. This was either caused by the high rpm of the pump or the heat generated by the gears. The fluid being pumped is recently condensed and so any sudden drop in pressure causes flash evaporation. I really need a slow reciprocating pump or other novel solution.

Cavitation is caused by a pump working sufficiently hard for the liquid either at the inlet or inside its casing to fall below its boiling pressure at that temperature.

Try cooling the liquid before it hits the pump, perhaps?

Try increasing the inlet pipe size, perhaps?

Hi des-eng,

Can you allow the condensed fluid build up in a small accumulation vessel. If you can, you would have lower volume change and therefore wouldn't drop the pressure as much as you were pumping. Also, (I'm assuming you know this, but just-in-case) is your pump the lowest point in the system?\

Mike

Try geared oil pump for VW 1600 air cooled engine, same principle, cheap and easy sourcing.

Most engines would be the same wouldn't they?

The Toyota 4A series are similar

Design Engineer, Try researching the "Tesla fluid pump", also known as the "boundary layer drag effect pump". It is used when shear is unacceptable and it does not cavitate.

Many airport fire departments use them as pumps for retardant foam.

It can be easily scaled for size, and it is very simple to build.

Dragon

GA

Hi Dragonsfarm,

The Tesla turbine is a very interesting principle, but I'm not sure if it's suitable for my application. I need 300psi pressure rise with low flow rates (~0.5L/min). Data on the pump is sparse and I cannot find any companies who manufacture tesla pumps.

The bottom line is that I do not have a development budget for this aspect of the project and so I am hoping to find an "off the shelf" solution. Many thanks for your suggestion.

Also found this CR4 thread

http://cr4.globalspec.com/thread/6542/Tesla-Turbine

bwire is on the right track. An oil pump would do the trick. Do not use a wet sump oil pump. Source out a dry sump oil pump used in race car applications. You have specified that your application will run temps around 100C. A fuel injection pump will definitely NOT handle that type of temp. A dry sump oil pump for racing applications should bring you up past 500 psi, will handle 100C temps and should not pose any cavitation problems depending on what your flow rate needs to be.

Try here:

http://www.demon-tweeks.co.uk/

Good luck

The other problem with using a fuel injector is that they use the fuel they are pumping as a cushion so the parts don't impact. If your liquid has different mechanicla properties from normal fuel you will have life issues down the road.

For an "off the shelf" idea how about a small triplex piston pump designed for pressure cleaning. Use whatever motor is compatible with the work source you are at. Good luck.

doesn't matter what product you use the cavitation problem will continue unless you can get your hands on the high pressure pumps used to pump #2 fuel oil into industrial 6 nozzle furnaces.

a company in toronto canada called inglis used to make them the name changed a while back to sunstrand inglis or inglis sunstrand. the innards have 2 sets of pumping gears set up in matching eliptical orbits. the pressure was regulated by a allen wrench after a side mounted plug was removed, the wrench was out into the sccrew haed and the pressure was able to be swet any where from mi9n. of 200p.si. to around 400 depending on how the soze of the nozzle.

'da ber

May also want to look in to the vane type pump similar to what is used to supply fuel to a gas turbine engine. The ones we had on the GE LM2500 engines on board ship would supply nearly 1,000 gals per hour at full power and over 350 psi, using marine diesel fuel, very similar to #2 fuel oil.

Is in some book a fuel injection pump,that's used in fridges or hydraulics.The diesel version is called "excello" or something like that.The hydraulic version is a piston type.In fridges, common ones,are so commons.If all of them works at differents temperatures and pressures and differents ways for lubrication...Why don't try with a common one those you get in any specialized commerce for refrigeration spare parts?

All refridge. compressors i've encountered are piston pumps. Automotive AC pumps are cheap and available too, if you project is off grid. So cheap i would not pursue a diesel or gasoline injector pumps. (just my humble opinion) Don't forget the off grid refridge with no moving parts too. (propane burner)

Good Luck,

wooly

Is your pumping requirement a long term operation, or simply an occasional need to pump the refrigerant?

Hi Bob,

The requirement is for long term operation.

I have a catalog from a company called Hydraulic Supply. They have many styles of pumps that could be used. They are at www.hydraulic-supply.com.

The Aro division of Ingersoll Rand has a piston pump that could be used if you have compressed air available. They are at www.arozone.com.

Eaton / Char-Lynn Hydraulics also manufactures many pumps. They are at www.eatonhydraulics.com This company also manufactures the Vickers brand of pumps.

Hypro pumps manufacture pumps of many types. They are at www.hypropumps.com. They manufacture some small displacement piston pumps that have ceramic plungers that should survive your refrigerant's chemical nature.

Hydura Products, Hydreco, John S. Barnes Corporation, also manufacture pumps that might be workable for you. I do not have web sites for them, but I'll bet you know how to find them.

As I was looking I did not find anything pre-made that had the volume and pressure that you wanted combined into a pump-motor combination. But if you have compressed air available where the pumping needs to be done, I feel that one of the Aro piston pumps would be easy to set up to perform exactly as you need. Use an air pressure regulator to limit the maximum discharge pressure, and air volume control to limit the speed of pumping so as to keep the suction pressure high enough that you will not bring on cavitation. Hope this helps. Just my mind running unchecked.