Repeated tubes failure in absorption chiller unit

[nostalgia]

Hi every body,

In one of our plant we are facing a repeated tubes failure in the tubes of high temperature generator of the double effect absorption chiller since 2008.
the chiller used water as a refrigerant, LiBr as an absorpant and used Lithium Chromate as an inhibitor. Lithium Chromate dosing stopped since 2006 since it is not environment friend.
Do thing that that failure because of stopping dosing the inhibitor OR by leaked air into the chiller?
In general, what is the possible cause of this repeated failure?
I will be grateful to you for answering those questions.

BR

[nostalgia]

up

up

[frank]

Have you had a chemical analysis of the refrigerant mixture?

have you carried out any preventative maintenance on the tubes?

Water quality is paramount on Absorption chillers

[dngupta]

It may be due to stopping dosing of inhibitor. if chromate is banned, some other inhibitor may be used. check the quality of steem also if using in generator.

[beppo]

How the vacuum condition in the chiller ? If the ambient air is leaking in, oxygen in the air will cause corrosion of metals and consume the inhibitor rapidly. You had better to check air-tightness of the chiller.

[Sridhar1312]

In Vapour absorption Machine total system need to be under vacuum and a small leak in to the system makes Oxygen gets in to the Absorbent Lithium Bromide which makes it highly corrosive.
Maintaining Vacuum in the system is critical in any vapour absorption system.
Cooling water quality and quantity is critical for VAM as the heat rejection factor is as high as 1.8 and possibility of scaling is directly proportional to water quality