6 replies to this topic

[manchester]

Hallo

I'm designing pump for pumping diesel oil for 11 gpm. Differential head is 35 ft. Which one is more economical, centrifugal type of diaphragm pump?
Your help is so appreciated..

Thanks a lot

[latexman]

There are some gear pumps that are made specifically for diesel (fuel oil) applications that are quite economical. Use Google to search for them. Try Viking Pumps.

[S.AHMAD]

Hallo

I'm designing pump for pumping diesel oil for 11 gpm. Differential head is 35 ft. Which one is more economical, centrifugal type of diaphragm pump?
Your help is so appreciated..

Thanks a lot

Hi

See attached pdf file. It looks like the plunger type is the right choice.

Attached Files

•  PumpSelectionCurve.pdf   103.03KB   152 downloads

[kkala]

I'm designing pump for pumping diesel oil for 11 gpm. Differential head is 35 ft. Which one is more economical, centrifugal type of diaphragm pump?

Once we installed diaphragm pumps (air driven) to transfer a mixture of industrial phosphoric acid and gypsum from a decanter. We realized that these pumps had following drawbacks in comparison to centrifugal ones:
1. Lower than expected flowrate. Flow was not quite smooth, it was like pulses. You could see the velocity approaching a max, then a min, and so on. So we thought frictional resistance was higher compared to continuous average flow.
2. More maintenance (especially on the valves, if I remember well).
Our conclusion was that centrifugal punps would do the job better, even though they had problems of gypsum plugging. The latter could be prevented through water injection.
Consequently I would rather go for centrifugal pumps, especially for diesel having no tendency to plug pipe and pump. The diagram brought by S.Ahmad (useful indeed) indicates that single stage centrifugal pumps are also suitable.
Modern pumps of piston type (including diaphragm) have means (e.g. air chambers) to smooth flow, but they may not be feasible for an 11 gpm pump. Centrifugal pump looks simpler and more energy efficient.

Edited by kkala, 08 February 2010 - 11:56 AM.

[S.AHMAD]

I'm designing pump for pumping diesel oil for 11 gpm. Differential head is 35 ft. Which one is more economical, centrifugal type of diaphragm pump?

Once we installed diaphragm pumps (air driven) to transfer a mixture of industrial phosphoric acid and gypsum from a decanter. We realized that these pumps had following drawbacks in comparison to centrifugal ones:
1. Lower than expected flowrate. Flow was not quite smooth, it was like pulses. You could see the velocity approaching a max, then a min, and so on. So we thought frictional resistance was higher compared to continuous average flow.
2. More maintenance (especially on the valves, if I remember well).
Our conclusion was that centrifugal punps would do the job better, even though they had problems of gypsum plugging. The latter could be prevented through water injection.
Consequently I would rather go for centrifugal pumps, especially for diesel having no tendency to plug pipe and pump. The diagram brought by S.Ahmad (useful indeed) indicates that single stage centrifugal pumps are also suitable.
Modern pumps of piston type (including diaphragm) have means (e.g. air chambers) to smooth flow, but they may not be feasible for an 11 gpm pump. Centrifugal pump looks simpler and more energy efficient.

I agree very much with kkala. Normally centrifugal pump is the first choice unless it is not suitable due to some specific reasons such as too small pumping rate and or too high discharge pressure that make centrifugal more expensive.

Edited by S.AHMAD, 08 February 2010 - 07:30 PM.

[akslzf]

Are you designing a pump or a system??!!
What's the application? For pumping diesel from a drum to an engine tank? There are umpteen Barrel emptying pumps in the market. An air driven diaphragm pump should also do the work.

[manchester]

Are you designing a pump or a system??!!
What's the application? For pumping diesel from a drum to an engine tank? There are umpteen Barrel emptying pumps in the market. An air driven diaphragm pump should also do the work.

I'm designing the system. Diesel is pumped for Fire Water Pump and emergency generator. Well, thanks for the responses. And special thanks for the graphs, Ahmad. You already help me twice