Syphon Pot Getting heated up in Plan 53.

[shyamshins]

Dear all respected members,

I have installed seal D RO seal its a back to back seal.

API plan given is Plan 53A with pumping screw which has left hand threads.
Process parameters are as follow :
Product : Organic material name of product unknown.
Tempreture : 200deg. celcius.
Inlet press : 0.5 Kg/cm2
Discharge press : 2 Kg/cm2.

Syphon pot gets heated up but tempreture is constant at 54deg. celcius.
Barrier fluid tempreture at inlet of seal is 74 Deg celcius & from outlet of seal to syphon pot is 79 deg.celcius.
Water supply is given to inlet of cooling coil of syphon pot.
Temp. of water connected at inlet of cooling coil is 36 deg. celcius & water coming from out of syphon pot is 39 deg.celcius.

The water coming from outlet of syphon pot should be hot but it is cool.

There is no thermosyphoning effect in syphon pot as syphon pot temp. is maintained at 54 deg. celcius.

What could be the reason?

 

[TD2K]

I wouldn't automatically be worried about the low water temperature rise. Most cooling water lines I've seen to seal systems are oversized meaning you get a lot more flow of water than the seal vendor will tell you that you need. You could simply have so much water flowing through the coil that you effectively have little temperature rise.

Plan 53A has a pumping ring so I'm not sure how much actual thermosyphon effect you need. What information do you have on the seal from your vendor? Typically a supply temperature and dT rise is given, how much heat is handled by the cooling system and the required water flow.

How are you measuring the temperature of the line to and from the seal and the pot itself? If barrier fluid is being pumped around by the pumping seal, the pot should be between 74C and 79C. Is there any chance the pumping seal isn't pumping or was installed incorrectly? Have you got more than 1 pot, do you see this on the other pumps or is it unique to this pump?

 

[georgeverghese]

Doesnt sound like there is anything wrong here - 79degC is within the 80degC max normal limit for seal return fluid. Seal pot would be cooler, since it is not directly in the recirculation path.