Dirty Wire Mesh Pad - Thoughts on Design

[rocketscientist]

I am doing part of a pressure profile for a desulfurization process. Does anyone have any ideas on what I should allow for a dirty mesh pad? Supposedly, this pad will be wetted by a timmed valve and spray nozzle. A report I saw from the Dutch in South Africa showed that their pressure drop doubled in less than 4 months service in a sulfur plant. This was for a wetted wire mesh pad. Obvously, I can't advise a client to clean their mesh pads every couple of months. But, it seems that is what the Dutch are coming up with. The article was a case history promoting a new type of wire mesh mist eliminator; you know the kind of article we are all suspicious of because things seem so dire if you don't use their product. It was entitled, "Increasing capacities by retrofitting mist eliminators" by Ziebolt.

Any experience to relate?

 

[STYMIEDPIPER]

Each time I have a question regarding pressure drops across a filter I usually contact the vendor. The sales engineer usually knows this type of information when asked. The sales engineer can convey what other users of the equipment have done to improve the life of the item (in this case a dirty mesh).

 

[ash9144]

My experience is that demister pads are overused and often misused. You need to look at what you are trying to remove from the gas stream. If solids are building up on the pad determine what the origin of the solids are. Some applications you can use a quick timed flush with a spray nozzle that you mention successfully. However if the solid is insoluble or becomes insoluble over time then a flush will only add to droplet entrainment. I would bet if sulfur is what is fouling your pad then you should probably look at alternatives for removing it. If it is sulfur then your mist pad is actually a filter and you should expect some routine change out frequency.