Liquid entering into reci.compressor

[f4760249]

Dear all,

I am regulerly having this problem while designing double stage reci.compressor pakage with interstage cooling fecility liquid ammonia entering into compressor and causing sever damages even though we are proviging electronic level switch for measuring liquid level & baffle plates in interstage vessel.

Please any body give some usefull information.

[bruceboldy]

The interstage cooler size is probably to small. You are causing higher velocity thru the tank then the size of the cross sectional area of the tank can allow both gravity, and dwell time to seperate the liquid from the gas stream.
Lower the liquid level , add a mist eliminator, use a tortuorous path for the gas to suction. Do you have the booster disc submurged in the liquid? Try injecting the make up liquid into the disc line from the booster to the interstage cooler.

just a few ideas i have used on this application.
Bruce

[lana]

Hi there,

I am not an ammonia expert but as far as I know you have to have three level controls.
one for low level which stops the liquid pump. Second one on the middle which energizes the solenoid valve to fill the separator. Third one on the high level which cuts off the compressor.

I suggest that you find the reason why the separator is completely filled up.

I am sure that ammonia experts will give you the best solution here.

Cheers

[Samarjit Sen]

I am not an expert in Ammonia system and as such am unable to suggest any thing. I am sure you will get the correct solution to your problem from the experts in this forum.

Sorry for not being able to help you. I am learning about ammonia from this forum.

[US Iceman]

Is the liquid entering the low-stage cylinders or the hi-stage cylinders?

[f4760249]

Thank's

I have checked all operating level,high level & low ) level switch and solenoid valves are working well.

Hi there,

I am not an ammonia expert but as far as I know you have to have three level controls.
one for low level which stops the liquid pump. Second one on the middle which energizes the solenoid valve to fill the separator. Third one on the high level which cuts off the compressor.

I suggest that you find the reason why the separator is completely filled up.

I am sure that ammonia experts will give you the best solution here.

Cheers

[f4760249]

it was high stage cyl's.

Is the liquid entering the low-stage cylinders or the hi-stage cylinders?

[US Iceman]

Does your compressor have an intercooler mounted on the compressor package, or, a separate vessel for intercooling?

If you are getting liquid in the hi-stage cylinders it is probably coming from the intercooler.

Sometimes the intercoolers have TXV's to control the superheat into the hi-stage cylinders. If you are getting liquid there I would look into the TXV operation to start with.

[TXiceman]

You need to post a sketch of the intercooler so we can se the design. They is a lot of science and some art that goes into the design.

You can use Stokes Equation to calculate the max velocity which is determined by the density of the liquid, the vapor, surface tension of the liquid and vertical separation height.

ASHRAE has a section on accumulator design which may help you.

Ken