Abnormal peak value of cold blowing for vertical molecular sieve
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My unit uses vertical molecular sieves. Recently, there has been no change in the gas processing capacity of the unit, nor have any parameters of the regeneration gas changed. The molecular sieves in tank A exhibit a \"double peak\" phenomenon, while the peak value in tank B remains normal. Can vertical molecular sieves experience uneven bed layers? I seek answers and discussions from the experts.
Are there any specific pictures? Did it just appear? Does it appear only once? Are the grids of the molecular sieve and alumina both normal?
Could you send the screenshots of the peaks from the past 3 days? It would be best to include both types of molecular sieves together for comparison
Could we utilize the similarities of horizontal bed layers to infer the possible behaviors of adsorbers with vertical radial flow structures, and then make judgments item by item?
Disorders in the regeneration process can lead to press accidents. Once, during operation, a disorder in the program caused the main intake valve to open suddenly, resulting in a rapid increase in pressure and thus an accident. The presence of multiple peaks indicates that there are pits in the molecular sieve bed; the number of peaks can be used to determine the number of such pits (N-1). Did the peak value change after this punch phenomenon occurred?
There are no images available for now; it occurred recently, not just once, and the abnormal peak levels persisted. However, this issue can be resolved – there is a DN50 bypass valve between the regenerating gas at the top of the molecular sieve and the cylinder; opening that valve will help reduce the abnormal peak levels. The grid has not been inspected yet.
There has been no occurrence of procedural disorders; one bucket is normal while the other is not, and the abnormal bucket A is located further away from the heater.
To answer comprehensively, I will upload the pictures in a couple of days. Personally, I don’t think unevenness of the bed layer is the cause, as there is a DN50 bypass valve at the top of the molecular sieve, connecting the regeneration gas pipeline to the cylinder. Previously, this valve was not opened during regeneration; but after the “double peak” phenomenon occurred, opening it allowed the curve to return to normal after a few cycles. Therefore, I don’t think unevenness of the bed layer is to blame. Instead, I believe that resistance is high in certain sections due to factors such as dust, resulting in less regeneration gas flowing through those areas, which explains why the peaks appear later compared to other sections. (The bypass valve allows the regeneration gas to be sent directly into the bed layer.)
Generally, when there is less gas flow, multiple peaks should not occur. If things improve after it is opened, it’s still possible that the gas flow is low; moreover, if certain areas are blocked, the gas won’t flow evenly into the bed layer, which can also lead to multiple peaks.
It’s likely that the bed layer is not level; make sure the pressure difference between the gas entering and leaving the molecular sieve is not too large.