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Heat generated by Gland Packing Calc?
2

Heat generated by Gland Packing Calc?

Heat generated by Gland Packing Calc?

(OP)
Anyone have a easy way to determine the potential heat developed in a stuffing box or gland packing? I've got the rpm, swept area of packing, diameter of sleeve, etc. I'm trying to estimate the temperature rise of the flush water. I figure a kinetic coef of friction to be 0.1 worst case. Thanks!

Keep the wheels on the ground
Bob
showshine@aol.com

RE: Heat generated by Gland Packing Calc?

2
Hello sprintcar

The heat generated at the packing is given by:

   Q = f (pi sq)PN (D sq)L/Cj

where:
       Q = Btu/min
       f = coefficient of friction
       P = liquid pressure at packing lb/in sq (gage)
       N = Shaft speed (rpm)
       D = Sleeve OD or packing ID in inches
       L = Sleeve length covered by packing in inches
       C = 12
       j = Mechanical equivalent of heat, 778 ft lb/Btu

Typical coefficients of friction are:

 Plain cotton = 0.22
 TFE-impregnated asbestos = 0.17
 Grease-lube asbestos = 0.10

RE: Heat generated by Gland Packing Calc?

(OP)
THANKS!!!!!

Keep the wheels on the ground
Bob
showshine@aol.com

RE: Heat generated by Gland Packing Calc?

(OP)
Fred - I'm getting some weird results
Would you please run the following and see what you get?
f =.17
P = 125psi gland water pressure
N = 500 rpm
D = 11 inches
L = 5 inches
Thanks!

Keep the wheels on the ground
Bob
showshine@aol.com

RE: Heat generated by Gland Packing Calc?

Hi sprintcar

I get 6,789 btu/min, if you plug this into Q = m Cp (T2-T1)where m = mass flowrate Cp = specific heat of water then knowing your inlet water temp T1 you can solve for the outlet water temp = T2.

fredb

RE: Heat generated by Gland Packing Calc?

(OP)
OK - had a problem with the spreadsheet - (missing () )
I'll add the Temp - I assume it's in Deg F, right?

Actually - this will work even better to determine the flow required to keep the water at a safe discharge temperature

Thanks again Fred!
Any other good stuff in your Pump Bag of Tricks?
email me direct if you'd like
showshine@aol.com

Keep the wheels on the ground
Bob
showshine@aol.com

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