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Effect of alkaline chemical for degreasing the copper metal

2007

Hi Gentlemen,
I have problem in refrigeration chiller unit, we have observed a serious heavy oil leakage from compressor dur to seal damage, the oil make-up was very high due to internal oil leak with the refrigerant. We observed abnormality in the process parameters i.e. temperature outlet from cooling evaporator due to poor heat transfer. We have big concerns on that the major cause is the oil contamination in the refrigeration system.

We have conducted the issue with contractor professional for HXR's cleaning, our HXR is shell and tube type, the shell side made of carbon steel where the refrigerant is there and the tubes side for cooling the water are made of copper. They recommend to do chemical cleaning for shell side where the oil contaminated by using alkaline solution called Tr-sodium phosphate (Na3PO4)and pH is 9-10. We know well the copper is very good metal in thermal conductivity but the resistivity against corrosion is very weak, it's not like CS or SS. We need your advice for the effect of such degreasing alkaline chemicals like Na2PO4 on the integrity of copper metal! Any recommendations from your experience?


WE would appreciate the reply and support as usual
Many Thanks

SAMI ZOBEIR
IBNRUSHD - K. SAUDI ARABIA