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# Temp. Rise In Centrifugal Pump

centrifugal pump

9 replies to this topic
|

### #1 raj shekhar

raj shekhar

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Posted 19 May 2020 - 04:56 PM

Hi Cheresources team,

I hope you all the doing well.

I want to calculate the the temp. rise in centrifugal pump when the pump is dead headed. I got the formula from the below link -

https://powderproces...ature_Rise.html

I used the formula to calculate the temp. rise below is the calculations steps -

Shut off BHP    5 hp
Fluid handled by pump    Ethanol
Fluid density    49.25 lb/ft³
Fluid specific heat    0.6 Btu/lb.°F
Boiling point of liquid    172 °F
Pump casing volume    2.5 ft³
Weight of the fluid inside casing    123 lb
Temperature rise    2.9 °F/min

Temp. rise per min is around 3 deg F, it seems quite high. I need your views on this value. Am I missing something here.

Thank you,

Raj Shekhar Ghosh

### #2 latexman

latexman

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Posted 19 May 2020 - 05:05 PM

In my experience, that seems reasonable.

### #3 Chemitofreak

Chemitofreak

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Posted 20 May 2020 - 01:22 AM

Hi,

Can we know the reason for calculating the temperature rise?

are you calculating the minimum re-circulation flow or something else?

### #4 fallah

fallah

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Posted 20 May 2020 - 01:59 AM

Temp. rise per min is around 3 deg F, it seems quite high. I need your views on this value. Am I missing something here.

Hi Raj,

It's not so high and as latexman mentioned is reasonable...

### #5 breizh

breizh

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• 5,055 posts

Posted 20 May 2020 - 02:49 AM

Hi,

Consider the document attached to support your work.

Good luck

Breizh

Edited by breizh, 20 May 2020 - 02:49 AM.

### #6 raj shekhar

raj shekhar

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Posted 20 May 2020 - 09:37 AM

Hi,

Can we know the reason for calculating the temperature rise?

are you calculating the minimum re-circulation flow or something else?

Hi,

The pump is used here for transferring Ethanol, as it's a flammable liquid I wanted to know what is the temp. rise if we dead head the pump for longer time. If the temp. rise is much higher I will go for a minimum re-circulation line.

Thank You,

Raj Shekhar Ghosh

### #7 raj shekhar

raj shekhar

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Posted 20 May 2020 - 09:38 AM

Thank you Latexman sir and Fallah sir for sharing your valuable experience with me.

### #8 raj shekhar

raj shekhar

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Posted 20 May 2020 - 09:38 AM

Hi,

Consider the document attached to support your work.

Good luck

Breizh

Thank you Beizh sir for the document.

### #9 Chemitofreak

Chemitofreak

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Posted 20 May 2020 - 09:56 AM

Hi,

Can we know the reason for calculating the temperature rise?

are you calculating the minimum re-circulation flow or something else?

Hi,

The pump is used here for transferring Ethanol, as it's a flammable liquid I wanted to know what is the temp. rise if we dead head the pump for longer time. If the temp. rise is much higher I will go for a minimum re-circulation line.

Thank You,

Raj Shekhar Ghosh

Please note that minimum re-circulation is required for two reason

1) To avoid cavitation related damage. That is what you are interested in

2) For Mechanical stability of a pump a min. flow is required.

I would suggest you to contact the pump vendor for minimum flow rather than you calculating the same..

I would also suggest you put a minimum flow line (with a RO or control valve based on the motor rating) considering the fluid is Ethanol

### #10 raj shekhar

raj shekhar

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• 38 posts

Posted 20 May 2020 - 03:49 PM

Hi,

Can we know the reason for calculating the temperature rise?

are you calculating the minimum re-circulation flow or something else?

Hi,

The pump is used here for transferring Ethanol, as it's a flammable liquid I wanted to know what is the temp. rise if we dead head the pump for longer time. If the temp. rise is much higher I will go for a minimum re-circulation line.

Thank You,

Raj Shekhar Ghosh

Please note that minimum re-circulation is required for two reason

1) To avoid cavitation related damage. That is what you are interested in

2) For Mechanical stability of a pump a min. flow is required.

I would suggest you to contact the pump vendor for minimum flow rather than you calculating the same..

I would also suggest you put a minimum flow line (with a RO or control valve based on the motor rating) considering the fluid is Ethanol

Thank you Chemitofreak, for your suggestion.