Slurry Pump

[josevski]

I just want to know the following and any help here will be greatly appreciated.
1. Is sealing pressure(chamber pressure) on slurry pump always the discharge pressure?
2. If I am calculating the heat soak of a slurry seal; would the process temperature be the same as the sealing temperature?
3. I assume that in double seal (pressurised), the inboard seal generated heat will be the heat soak from process fluid and friction heat generated by the faces. In the outboard, only heat generated by the faces. Is this correct?
4. Double seal(Pressurized): I assume that pressure difference of inboard seal is chamber pressure(sealing press)and barrier pressure. In outboard seal it will be pressure difference between barrier pressure and atmosphere(can I assume 1 bar as atmosphere pressure or zero?) Is this correct? Thanks in advance.

 

[Scipio]

Josevski,

1. Chamber pressure varies depending on pump construction and seal flush plan. With typical construction (i.e. end suction top discharge single stage overhung centrifugal pump) it winds suction pressure plus 10-25% of the differential head. Double suction pumps or pumps like the Wilfley 2K with the impeller eye facing the seal chamber, or progressing cavity pumps are just suction pressure, though PC pumps can be run in reverse which places the seal chamber under full discharge pressure.
2. Unless there's a significant reason the fluid temperature in the seal chamber would be different like a jacketed seal chamber, yep.
3. Sounds about right with the same logic as above.
4. Yep.

Mike Henderson, P. Eng.