Condenser installation
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The company has a vertical shell-and-tube condenser, and leakage has occurred multiple times at the welds of the tubes on the upper tube sheet; these leaks have been repaired several times. No such problems have been found on the lower tube sheet. The steam flowing through the tube side is corrosive, high-pressure, and high-temperature, while the water on the shell side is used for cooling. In order to extend the service life of this equipment (since a new one has not yet arrived), it is planned to reverse the orientation of the condenser’s shell. I would like to know what issues need to be taken into consideration and whether this approach is feasible
The sizes of the gas and liquid inlets and outlets are the same; is there a baffle at the gas inlet after the change? If there are no major changes in the above two aspects, it should be possible to reverse the arrangement, but how can the position of the supports be adjusted?
Precautions: 1. In the case of a single tube pass, the upper and lower tube boxes remain unchanged; only the tube bundle is rotated, so the inlet for the gas flow in this tube pass and its internal structure will not change. For multiple tube passes, the steps mentioned above must be followed. 2. After modifying components such as supports that require changes, a visual inspection should reveal no obvious defects. The tube sheet needs to be recalculated as the static pressure from the owner has changed. 3. If, after the modification, the upper tube box becomes the lower tube box, the tube box flanges need to be recalculated to ensure they meet the requirements, as the static pressure of the liquid column changes. 4. The tube-sheet joints must meet the requirements specified in the drawings during manufacturing, to prevent the heat exchange tubes from shifting once corrosion occurs at the welds between the upper and lower tubes, which could lead to leaks at both the upper and lower tube sheets. 5. After all modifications have been completed and inspected to meet requirements, a hydrostatic test is conducted on the tube side and shell side; once the pressure test is successful, it can be put into use.
If it is necessary to ensure the proper operation of the equipment, I personally believe that the situation described by the original poster will not improve much, because no matter how things are changed, the weld height at the junction of the pipes and the plate must be maintained. If the minimum weld thickness requirement is not met, the welds will crack, causing the pipes to separate from the plate at those welds and leading to leaks. To resolve this issue fundamentally, it is recommended to use more reliable materials to build a new device.
There should be no problem, as long as the end caps are not replaced; it’s just a matter of whether there is any deviation in the flange alignment.
Personally, I think it’s not possible; the structure cannot be changed, so it cannot be repurposed. Especially with vertical heat exchangers, the upper and lower structures are completely different.
The newly manufactured equipment has not arrived yet, and production schedules are pressing. The welding requirements for the upper and lower tube sheets are the same; although the upper tube sheet is subjected to greater gas-phase pressure due to the presence of baffles. In terms of production, the pressure is not a constant value; it varies, and similarly, the temperature is not maintained at a constant level.
The dimensions of the head pipe flanges are the same. Including the thickness of the upper and lower tube sheets of the cylinder is the same as well
The dimensions on the flange drawings match those of the bolt positions; the actual alignment deviation is still unknown