what would cause a screw compressor to scrap the housing

[joeywpittman]

I am relaying a question?
A screw compressor is scraping the housing at letters A,R,Q. What do you think the problem is? (¿¿¿Bad thrust bearings MAYBE???)

 

[MikeHalloran]

Dirt or burrs in the bottom end of the upper bearing bores?

No pressure above seals 16,37 to balance the housing pressure?



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[imok2]

Sounds like the thrust bearings are going out, this could be due to pressure drop like a partially plugged filter also” The operating discharge temperature plays a key role when striving for a steady-state normal oil dilution rate. Adequate discharge superheat measurements are an excellent indicator of stabilized oil dilution. Discharge oil separators should operate above 30oF (-1oC) discharge superheat. If the discharge temperature has an insufficient margin from the condensing temperature, refrigerant dilution can become extreme and detrimental to the bearing oil supply viscosity. Extreme low ambient temperature exposure to the oil separator/reservoir can have a detrimental impact to the oil dilution rate. Abnormally sustained liquid slugging into the suction of a screw compressor due to unbalanced evaporator heat loads will disturb the discharge superheat and may jeopardize the resultant bearing oil supply viscosity. Pressure drop on the oil feed lines can release refrigerant dilution causing the mechanical shaft seal face to operate at an excessive temperature. Oil feed line pressure drop may also reduce the balance piston thrust load compensation. Minimum pressure drop in compressor lube feed lines will result in optimum long-term service intervals”.(Quote)

 

[MintJulep]

Are there shims in the thrust bearing stack that could have been mis-selected at assembly?