Freon Condenser Tubing Evaluation of Remaining Life?

I understand you are talking about a heat exchanger, but the type escapes me. You want to cool down the hot side of a freon stream with seawater? Where are the fins? In boat many times double wall pipes ( one pipe in another) is used.

Is your type a box type cylinder? But the fins?

To have less deposit from organic species I think a downstream water cooling is more effective because you heat these that much at the entrance, that they don't like to stay inside. But the pitting is removal of material? That is electrochemie. Please explain

it is very important that there be a moisture absorber that is intact and has a reserve. The copper is inert to freons, but if any water is not absorbed the water has a tendency to react with the freons to form acids, which eat copper.

Annual service checks for water,often there is some type of water presence indicator. They also make the system with nipples and valves to allow for dryer replacement.

small domestic units are fully sealed, with integral dryers for the life of the equipment

Makes sense, but how is the complete setup? Do I miss something? GA

we can work on this issue if you like, email me details of investigations, test results and application.

Insist the vendor (or Contractor) furnish a new exchanger bundle that has good mechanical properties.

This sounds like a used exchanger that has been reamed out to clean it = less thickness left and many attachment points as well as potential pinholes. It is true that some marine organisms are inhibited by copper, but not all. Heat exchangers like this should be made to allow for the tube ends to project out of the shell to allow for cleaning without breaking into the freon loop. This cleaning should be frequent enough to prevent deeper calcareous growth and the cleaning brush should not scrape the surface. In addition, a daily halt of the water through to allow the water inside to reach killing temperature from the freon hotside. This might be 70-80 C. This will not kill bacteria but it will halt most other things, and allow your exchanger to run longer between reamings.

I would re-tube the condensers

As for risk assessment; I would consider the following:

-environmental damage due to a leak or multiple leaks

-as they are marine condensers and therefore mobile, if there is a major leak while the ship is in transit, how close is the repair facility? Would there be product loss? etc.

-does the risk involved of not repairing them, exceed the cost of repairing them?

-is reliability a concern?

-can you predict the future? If so than by a lottery ticket.

The Life of your Condenser depend on how you do your PPM,since you are using sea water.one thing you dont mention is the type of Condenser you are using but, i assumed this is Shell andTube Type.in my Previous experienced they last more than 5 years.do you know why they breakdown pre maturely? Poor maintenance and frequent used of Descaling Chemicals. Chemicals are Acid Base.use Plastic Brush suitable for the size of your condenser tubings dont let the scale become hard before you do your next PPM since sea water dont require water treatment but Filtering.believe me even you installed that condenser you have just recieved they will last 5 years or probably 10 if you do good ppm scheduling

climbqdh has explained the problems with the Condenser (it is a shell and tube) and also highlighted steps that will be taken to rectify (re-tube). But, his main query is how to determine the risk and life of a Condenser having Cu/Ni tubes using seawater.

Well, answering this is not going to be easy because i presume the Condensers are in a sea going vessel. The life of the Condenser tubes will depend on the quality of water that it handles, being a sea going vessel it is difficult to control the water quality as opposed to a stationary condenser where you can determine and take necessary steps to control the water quality, by this i mean any unwanted stuff that gets pumped in to the cooling water which can get attached to the tubes or even score and damage the tubes thereby effectively reducing its life. Fine mesh strainers in the pump's discharge could be a way out.

First of all one should not have used 90/10 Cu-Ni tubes with Sea water, particularly, if it is brakish and with high level of Ammonia. Titainium Tubes are prefered for sea water application.Please also check the tube side velocity. I am pretty sure with the type of tube failure, you are having it is due to high velocity. In my opinion the velocity with high level of suspended solids( Sea Water ) it shoud not be more than 2.0 M/sec)

Coming to the question asked, you are loolking for the residdual life of the tubes. It is very difficult to asses. However, I would suggest to asses the life on the bais of statistical control. how much time it has taken to damage the tubes and what is the thickness of tube left out. Now the rate of failure shall be acclerted as the erosion and corrosion of tubes will be much faster. You can also take samples of tubes and do accelerated similation test in the labratory foe the assesment.

Agree that Titanium tubing is the better way to go, but with sea water there is a chance of hydride build up and this will cause titanium tubes to become brittle… To counter act the hydride put an electrical charge to the tube sheet…