Screw compressor failure

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14-10-2010, 02:55 PM
christossev

Screw compressor failure

Hi everybody! I am examining a case of a J&E HallSrew HS2028 compressor that failed. The cast body of the compressor cracked/fractured into pieces destroying all of the internal parts of the compressor (stars, slide valves etc). The claim is that large amounts of liquid refrigerant entered the compressor from the liquid injection line (used to cool the oil) due to a fault of the controller that closes the solenoid valve.
Has anybody faced the similar problems and if yeas what was the cause of the failure?
Thanks!
14-10-2010, 06:01 PM
Sandro Baptista

Re: Screw compressor failure

Quote:

Originally Posted by christossev

due to a fault of the controller that closes the solenoid valve.
Thanks!

If the solenoid liquid is closed how could liquid refrigerant have entered to the compressor by that way?
15-10-2010, 02:35 PM
christossev

Re: Screw compressor failure

Quote:

Originally Posted by Sandro Baptista

If the solenoid liquid is closed how could liquid refrigerant have entered to the compressor by that way?

The solenoid remained open not closed!
15-10-2010, 05:34 PM
NoNickName

Re: Screw compressor failure

Yes, the compression of liquid between the rotors causes the two to separate and grind the housing.
But J&E have single screw and two daisies (stars), so I don't think that large amount of liquid could cause that.
15-10-2010, 07:26 PM
Grizzly

Re: Screw compressor failure

Quote:

Originally Posted by NoNickName

Yes, the compression of liquid between the rotors causes the two to separate and grind the housing.
But J&E have single screw and two daisies (stars), so I don't think that large amount of liquid could cause that.

Good points, also there is a restricting orifice to flash off the liquid if I remember correctly.

I suppose it's possible that the liquid refrigerant level in the compressor could increase.
Due to the solenoid remaining open. But surely the crankcase heater would boil off the refrigerant.

I would be looking at your system level controls for high levels.
Resulting in Suction line liquid carry over.

I am at a loss as to how you could create such a huge amount of damage otherwise.
The one Benifit of Hall screws is that the star wheels are Sacrificial.
And easily replaced.

What you are describing christossev sound more like huge thermal shock damage.
But all the Hallscrews that I used to look after were well maintained and never failed the way you describe.
Their own manual even states after 25yrs running check the main bearings for wear.

There is more to this than you are saying?
Grizzly