Heat exchanger high delta p 1

[Chem2020]

This is a problem with heat exhanger unit. It is a multi tube type heat exchanger. I was told by the operator when he opens the bypass valve the pump feeding discharge to the heat exchanger drops 20#. There are two bag filters upstream of the heat exchanger. First I thought filters might need to get changed but the operator gets high delta P throgh the heat exchanger.

Any thought what the problem might be?

 

[Latexman]

First you have to determine if there really is a problem. What is the dP supposed to be at the flow rate you are running? Look in the equipment file for a spec., capacity test data, operating data history, maintenance records, sketches showing how many leaking tubes have been plugged over the years, etc. I've seen exchangers where 20 psi dP is normal.

If it is abnormal, my first guess would be filterable solids have somehow by-passed the filter and plugged some of the tubes. Second guess, fouling.

Good luck,
Latexman

 

[choack]

Is it the Shell side or the tube side?

Maybe in the first place the configuration of the baffles or the TEMA type really gives high delta P.

 

[rmw]

I assume that when you say "the pump drops 20#" you mean the pump discharge pressure drops 20#.

Everything sounds perfectly normal to me. You are bypassing something - you didn't stipulate whether the Hx was bypassed or the filters, however, I suspect it is the Hx. Regardless, something in the pump discharge flow stream with a pressure drop was bypassed and the pump had less "system" resistance and ran out out to the right on its curve.

Want to make a bet? I'll bet that your pump's motor amps jump up too when he opens the bypass. Try it.

All sounds well as I see it.

rmw