Core pulling of U-tube heat exchangers? ? ? ? Consult an expert? ? ?
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There is a U-tube heat exchanger here that requires core extraction to replace the shell-side gaskets. This cooler is installed at a height of 15 meters. There is no core extraction machine on site, so it’s not possible to remove the entire cooler and lower it to the ground for core extraction. However, there are two cranes available. There is also no space in the horizontal direction in front of the cooler to install or support it; the space in front allows the cooler to be pulled out. The key issue now is how to use these two cranes in tandem to keep the core level ? (The horizontal movement can be achieved by using a winch); the core has a diameter of 1.2 meters, a length of 9 meters, and a weight of 12 tons. Is it possible to suspend it directly from the pipe bundle using slings? ? How to operate it? ? ? How can one ensure horizontality while pulling the core out horizontally on one side? ? Could someone with experience help? ? Thank you
This is quite difficult. But if you change the mat, you don’t need to take everything out, right?
It should be possible to suspend the pipe bundle directly with slings; are there slides on the housing?
1. This can protect the heat exchange tubes, and lifting lugs can then be welded to the partition. It will be better if it is pulled out like this. When inserting it inside, the housing can be tilted to create a certain slope; once it is in position at the lifting lugs, those lugs can be cut off. When operating, be sure to protect the pipes by covering them with asbestos sheets or similar materials.
1. Just replace the gasket – there’s no need to pull everything out; pulling it out a certain length is sufficient； 2. A platform is welded onto the edge of the platform, leaving no space for maintenance, which seriously violates relevant regulations ； 3. Lower the entire heat exchanger, remove the core once the work is done, and then put it back in place
Thank you all. We used two cranes and put in a lot of effort to finally get this done. The gasket used is a metal-graphite gasket; in the event of a leak, the only option is to pull out the core. There are no slides on the core itself, only two guide rails with a diameter of 35 mm beneath its structure, and it has to be pulled out through friction. The problem is that there’s no space at the front to install a hook support, so we had to arrange things diagonally. Without a core-pulling machine, it was extremely difficult. It’s finally done, but I don’t know if there are any leaks. That gasket with graphite wrapped around metal, used to seal the water side of the cooler (where the water temperature is around 90 degrees Celsius), does it need any sealing compound or something applied to it? ? If you just apply pressure like this, won’t it leak again if something is slightly off? ? Any good suggestions? ?
Reply to 5# Lao Gui’s Son: To prevent an increase in leakage points, this cooler has five inlet pipes, all of which are welded to the cooler itself. Together with the five outlet pipes, that makes ten pipes in total. It’s also not possible to cut these pipes, as the gas inside still needs to go into the compressor. Welding slag is difficult to deal with, and after welding, inspections are necessary. It’s therefore impossible to remove the entire cooler at once.
It’s another design with Chinese characteristics; the assumption is that the equipment installed will never break, which puts a strain on the maintenance staff
A sling is used on the crane hook for adjustment
:PHehe! You’ve really worked hard!