Minimum spray density of packed tower
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Due to work needs, when designing a packed absorption tower, the spray density can only be 0.2~0.3 m3/m2h, and the packing is divided into three parts: Part of it is wire mesh packing, part of it is corrugated orifice plate, part of it is CMR, the medium is water, and the material is 316. Can the three kinds of packing be fully wetted under such a small spray density, and can their effects be fully exerted? Please discuss it? When designing packed towers at work, have you ever designed a tower with such a small spray density? Introductions in various packing books say that the minimum spray density of wire mesh and orifice plates can be 0.2m3/m2h, but can it really be so small? Do you have any practical experience?
Why is no one discussing it? Just support it yourself!
Has the host's problem been resolved? I'm also concerned about this issue.
I think your plan should be changed. Can you increase the return flow and add a return line to the bottom filler? This will not only ensure the saturation of the absorbent, but also ensure large flow absorption at the top to ensure absorption efficiency.
Theoretically, the wire mesh packing can tolerate such a small liquid flow rate, but it is difficult to say about the orifice plate corrugation and CMR. Small flow rate is not terrible, but rough design and random installation are terrible. Low liquid volume makes these hazards more prominent, and increasing the reflux ratio will directly cause an increase in operating costs. So please share the final solution with the original poster.
The wettability of wire mesh filler should be greater than 0.2, the corrugation of the plate should be greater than 2, the fillers such as scattered pairs of CMR need to be greater than 3, and the fillers with good wettability such as ceramics and aluminum can be greater than 1
The spray density in the vacuum tower of oil refining cannot be less than 0.5. If it is too small, the liquid distribution will be slightly uneven and coking will occur.； But in other distillation towers, the spray density can be smaller, but I feel it should not be less than 0.2m3/m2·h. The reason is as mentioned on the 5th floor. If the spray density is too small, the anti-interference ability of the system will be very poor. We have done a project before, and the spray density reached 0.08m3/m2·h, not all of it, just a section. There was no other feedback from customers after the tower was opened, so it should still be OK. We are currently calculating a project. The bottom spray density of the upper filler is 0.1m3/m2·h, and the top spray density is about 0.7. I tried to reduce the diameter of the tower, but the resistance increased sharply. Consider now whether increasing the reflow ratio is worth it. A reflow ratio of 0.07 is sufficient. I have chosen 0.7 now. The filler is mesh filler.
For orifice plate corrugated packing in the oil refining vacuum tower, the design institute recommends that the minimum spray density is not less than 0.5. It is estimated that it can be smaller in other areas.
I just applied for a number and don’t know how to ask questions yet. . Let me ask you a question and ask experts to help answer it. For general packed towers, when the actual amount of absorbent that can be used cannot reach the minimum spray density, the industry has to use liquid partial circulation operation to increase the spray density. Otherwise, a plate tower must be used. This is a true or false question. Is the final answer right or wrong?