Purge of continuous reforming dechlorination tank.
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Our installation is continuous reforming. Among them are dechlorination tanks for pressurized hydrogen. Now the dechlorination agent (activated alumina) in the tank needs to be replaced. After the blind plate of the dechlorination tank is isolated, it is purged intermittently with nitrogen.: Each time the nitrogen is pressurized to 4-5kg and then the pressure is released to the torch. This has been done many times, but the combustible gas content still does not meet the requirements. Later, it was changed to continuous nitrogen purging, and combustible gas could still be detected after a long time. Nitrogen purging effect is too poor. Does anyone have a better way? Is steam purging okay? If steam is used, can the dechlorination tank that normally runs with 90% purity hydrogen pass steam? And the dechlorination agent will harden when steam absorbs water. I hope friends who have experience in replacing dechlorinating agents in dechlorination tanks will give you some advice.
There is no need to use intermittent purging, just use steam to purge the torch continuously for 4-8 hours, and then change to nitrogen to ensure that the combustible gas is qualified. At present, the strength of the dechlorination agent can completely eliminate the need to consider hardening. In addition, can the dechlorination tank that normally operates with 90% purity hydrogen pass steam? Why should steam be introduced normally? When shutting down, you can purge according to my method.
When we replace the dechlorination tank, we replace it with nitrogen and then disassemble the laxative.
Steam should not be used. Aluminum oxide or zinc oxide will soften when exposed to water, or even bond, making it difficult to remove. I'm afraid it will require mechanical shredding. We use the method of vacuuming and then using nitrogen to break the vacuum, and the agent can be discharged qualified in three or four times. In addition, some devices use the hot nitrogen purge and replacement method, which takes a longer time, and can also be qualified. For reference only
The hydrogen pipeline is purged by vacuuming, and the gas phase dechlorination tank should be equipped with a vacuuming pipeline.
It is best not to purge the dechlorination agent with steam, but to purge it with nitrogen and vacuum. If the replacement effect is not good, I hope you will consider the replacement method. For example, consider whether all low-point condensation is discharged. Over time, a lot of condensate will appear at the low point of the dechlorination tank. This part of the condensate has a high boiling point and evaporates very slowly at room temperature. Therefore, the condensate must be discharged at a low point during purging. ； The condensate in the dechlorination agent bed will generally collect in the lower part of the dechlorination tank, so when purging, it is best to supply air from the upper part and exhaust the lower part, otherwise it will be difficult to purge clean. I hope the above suggestions are helpful to your installation.
It is normal for the nitrogen purging time to be longer. In my case, it is about 10 days of continuous purging. I just changed the agent this month. If you have any other questions, please contact me!