Methods for detecting internal leaks in tubular heat exchangers
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If there is a leak in the tubes inside the heat exchanger, what methods can be used to detect and repair it? Please offer some guidance
The usual method is to pressurize the inner wall of the shell side with nitrogen, and apply soapy water to the tubes; the tubes that produce bubbles are those that are leaking. The typical solution is to use plugs made of the same material as the tubes in question, sealing them off on both sides. The downside of this approach is that it reduces the heat exchange area. Hehe, please give new answers some attention; kindly provide me with some rewards so that I can upgrade.
When it is difficult to disassemble, ammonia can be introduced into the shell layer; for the tube layer, filter paper can be attached at the tube sheet ends and phenolphthalein can be used for leak detection, which yields good results. Soap water makes it hard to detect small leaks. The method for dealing with leaks is the same as described above.
What 2# is referring to is a relatively traditional, but also very practical method! !
Are there any specific methods and precautions for detecting ammonia leaks?
The simplest and most common method to check for leaks in the tubes of a shell-and-tube heat exchanger is to open the end cap of the heat exchanger, and then use a water pump to feed water or steam into the shell side of the heat exchanger through the pipes; water is preferred. The pressure of the water entering the shell side via the pump should be around 0.2–0.35 MPa. If there are leaks in some of the tubes, it will be clear at the tube sheet where the end cap is open – the tube from which water flows indicates that tube is leaking. Repair methods can be used to ensure that the heat exchanger can continue to be used. If only a small number of tubes are leaking and repairs do not affect the overall performance of the heat exchanger, the following methods can be employed: 1. Weld the ends of the leaking tubes shut. 2. If the shell side of the heat exchanger is at atmospheric pressure, then pre-made wooden plugs can be used to seal both ends of the tubes, which can be secured in place with nails. Make sure that the wooden plugs have been processed on a lathe to ensure they are smooth and regular in shape. If the amount of leakage from the pipes exceeds one-third, approaching one-half, then this heat exchanger should be replaced.