Questions regarding PSA adsorption towers
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PSA units generally, as mentioned by institutions like Huaxi Institute or Tianyi, have adsorbents that can last around 15 years. However, our adsorption towers do not have any access points for removing the adsorbents. I would like to ask everyone: since adsorption towers are classified as Category II containers, the regulations stipulate that they should be subject to a comprehensive inspection after six years, under the new second-level safety assessment criteria. It is not possible to conduct a comprehensive inspection without removing the adsorbents, but removing them likely means that they can no longer be used, as there are six different types of adsorbents involved, and it is difficult to sort and classify them after removal. How does Haiyou handle this situation?
It can be done by using vacuum extraction at the outlet of the adsorption tower
1. If the adsorbent can be reused, the cover of the adsorption tower can be opened during unloading to remove the grating screen; then someone can enter the tower to clean out the adsorbent. Since the adsorbent is filled in layers, mixing only occurs at the interface between the two types of adsorbent； Separate them when unloading and make proper markings ； The used adsorbent can be discarded, and a smaller amount can be replaced with new adsorbent. 2. That’s how we do it; it’s just a bit more troublesome when uninstalling ； It is important to note that the system replacement inside the adsorption tower must be thorough; in addition, air respirators must be worn, and dedicated personnel should be assigned for supervision. Those entering the tower should also change shifts frequently. Safety first.
3# czzjm are all evacuated, and generally someone recovers them
Is an inspection required every 6 years? That is indeed a problem. Even though vacuum can be used to remove the adsorbent, doing so usually renders the adsorbent unusable; in that case, new adsorbent has to be purchased. How is the cost for that calculated?
The new regulatory requirements state: 7.6 Handling of special inspection situations (1) For pressure vessels specified in the design drawings as not being suitable for regular inspections, the user entity shall submit a written explanation, which shall then be filed with the registration authority responsible for oversight； (2) For pressure vessels that cannot undergo regular inspections on schedule due to special circumstances, an application must be submitted by the unit using the vessel; such an application must be approved by the person in charge of that unit, and consent from the original inspection agency must also be obtained. After registration with the authority responsible for overseeing vessel use, the inspection can be postponed. Alternatively, the unit using the vessel may submit an application and follow the procedures specified in section 7.7 of these regulations ； (3) For pressure vessels that cannot undergo regular inspections or for which such inspections cannot be carried out on schedule, reliable monitoring and emergency response measures must be established; if problems arise due to the failure to implement these monitoring measures, the entity using the vessel shall be held responsible
For future devices, an inspection every 6 years should be necessary. For older devices, two methods can be used: evacuation or manual removal. Evacuation is faster, but if there are multiple types of adsorbents in the tower, the degree of wear and damage is higher; therefore, manual removal is recommended, though safety must be taken into account. Even after replacement, the adsorbents can still release toxic gases, so it’s best to keep the bottom area continuously evacuated, along with wearing a gas mask