Industrial Grinder Dust Control

The first thing I would try is to dry the compressed air so you don't have the condensate and the issues that result.

milo

I agree with Milo about drying the air. I would also look at your air supply. There may be not enough volume of air to properly clean the bags. What kind of air pressure drop do you have while its cleaning?

There may be not enough volume of air for pulsing the (RAJF) Reverse Air jet filter

The frequency of cleaning certainly is not good.

You talk of 30 sec interval, it does not mean any thing.

Please give this info I will help you.

Solenoid on time/ Solenoid off time

I also do not see any venturi or compressed air nozzles in your photos. Where are they and are they correctly sized?

What is the solenoid valve size, bag size etc?

With more information of your system we can help you more!

First off, put a water remover or dehumidifier on your compressed air supply.

You didn't mention and the pictures don't show it but do you have a small air receiver or reservoir before your solenoids? Our own dust filter's performance improved when we installed one. It's just a large length of pipe that we used as a header. It stores enough air in it to blast a sufficient volume through the nozzles.

I also agree with Sisira with regards to the absence of nozzles and venturis. Did you remove them or there have never been any?

Again, Sisira is correct with regards to the ON time of the solenoids. Too short and the air jet will be ineffective. Too long and your system will not have enough air pressure built up for the next blast (in addition to wasting compressed air).

Are your solenoids firing all at the same time ? Not good, you won't have enough air to push through all the filters.

If not at the same time, do you fire them sequentially (row 1, row 2, row 3, row 4, row 5) or non-sequentially (row 1, row 3, row 5, row 2, row 4)?

Sequential is not advised because when you fire row 2 (for example) after firing row 1, you'll be depositing dust onto the newly cleaned row 1 (because they are next to each other).

If you fire them non-sequentially, try to evaluate your 30 second interval. After firing row 1, it will be 150 seconds (2½ minutes) before it fires again. Is this enough? If it's too short, there will not be enough dust accumulation on the filter for it to cake and drop to the bottom. You'll just be blowing dust around.

If it's too long, the filters will accumulate too much on them, reducing the filtering efficiency and possibly cause damage to the filter bags due to high differential pressure.

Do you have a differential pressure gauge or transmitter to monitor the pressure drop across the filters? This will enable you to analyze the efficiency of your filter. You can even use this to control when to fire your solenoids. It will also tell you if you have a damaged filter bag.

I'm not a dust filter expert. I learned what I know from analyzing our own dust filters.

regards,

Vulcan

Yes you people are on right track. same question i asked my supplier why he has not given nozzles and venturis (please show any photo if you have).because whatever he given solenoids and timer cards will be useless. effect of this blast will be poor if he is keeping just like pipes with holes. this blast air will get sucked by blower. Your advice for sequential air blast is really appriciated. We have one small reciever before solenoids. Please explain me how can I put differential pressure gauge or transmitter to monitor the presssure drop acrosss the filters.

Please guide me.

Here's a simple drawing:

As you mentioned, the differential pressure gauge or transmitter is placed across the filters. When the filters are clean, the differential pressure will be low. When the filters are partially clogged or caked, the pressure will be moderate (how much depends on your application and experience). If the filters are completely clogged, the pressure will be very high. If one or more bags become damaged, you'll get a sudden drop in pressure.

regards,

Vulcan

Thanks Vulcan. Anybody knows about nozzles and venturies. how they suppose to be mounted.