Effect of water injection at the cut end of an externally heated single furnace tube on its service life
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As the title suggests, in the external heat extraction operation mode, water supply is cut off for each individual furnace tube, while the return line remains intact. Will this cause the furnace tubes to burst, and will it affect their service life?
Steam provides protection; pressure is maintained through venting to prevent the catalyst from becoming clogged
Why isn’t the return line removed? There is a large amount of steam leakage, which has a significant impact on regeneration; it’s also bad for the catalysts and the flue gas treatment equipment.
It will definitely affect the nearby tubes and reduce their service life
Since it has leaked, both ends should be closed, the entire section should be cut out, and a small vent line in the middle should be opened to release pressure. There’s no reason to keep it in place and allowing leakage to continue; it will certainly cause damage to other coils, as well as to the regenerated catalyst.
One more thing: when we remove the upper water section, it is necessary to replace the upper water gasket, not because of a burst pipe in the tube bundle.
If a valve doesn’t close, pressure buildup and pipe rupture won’t occur, but the question is: can a gasket be replaced in such a situation?
Regarding the issue of replacing the gasket, there is a leak at the flange in front of the water valve on the furnace tube; it cannot be removed directly – one must use clamps or enclose it with a box； If there is a leak at the flange behind the water supply valve, close the water supply valve and the steam return valve of the corresponding furnace tube, open the vent to drain the fluid in the pipeline, and observe the changes in pressure. Check to determine whether there is internal leakage in the valve. If the internal leakage is minor, protective equipment can be worn and supervision ensured before removing the valve; however, proper safety measures must be taken. If the internal leakage is severe, the flange must not be removed to prevent large amounts of steam from escaping and causing injuries or deaths. A pressure of 35 kilograms is no joke – it’s better to work slowly than to risk the lives of employees.
If it has already been completely removed and is in a dry-fire state, there should be no consideration of putting it back into use, as there is a temperature difference of over 350°C; an explosion of the tube during reactivation would be very dangerous, and it could even trigger the main air system’s safety protection mechanisms. The absence of one tube has little impact on the external heat exchanger.