Kevin,

To solve your problem you should read my article "Design Guide for Dust Collectors" published in Chemical Engineering in April 2005. This article will be a great help to you in understanding the reasons for poor dust collector performance.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dear Amrit,

Could you send me this article"Design Guide for Dust Collectors" to me?

I have read your another article"theory and design of dilute pneumatic conveying systems".It's really helpful to me.

My email is yuwenjie2002@msn.com

thank you

■

kevinjcg

When you say "not suitable", do you mean that the the dust collection system airflow is reduced because the bagfilter is not cleaning properly?

What is the pressure differential across the filter bags?

What is the time interval between successive pulses? If it is too short (less than 10 to 15 sec.) the compressed air manifold may not have enough time to recover pressure between pulses and poor cleaning will result.

Note that the compressed air must be free of oil and moisture.

Michael Reid. ■

dear kevinjcg

From your info I calculated the following:

Filter area = 3.14 * 0.15 * 2 * 96 = 90 m2

Blower volume = 10000/60 = 166.7 m3/min

This gives a filterload of 166.7/90 = 1.84 m/min

Whether this filterload is to high, has to be checked with the experience of the filter supplier or (even better) with the experience of other forum members.

If carbon black is very light and sticky to the filter material (f.i. electro statically),

the filter load should be lower or another filtermaterial should be applied.

pulse valve diameter should be checked with the supplier.

( 1” membrane valve with a 1”blow pipe seems OK for 6 bags.

(bores in pipes approx. 4 – 5 mm)

Too fierce pulsing can destroy the carbon black agglomerations, which are shaken off the

filter bag, into dust again.

This dust will not fall against the air flow in to the hopper and will stay between the filters.

(Filter is holding the dust)

Also the upward air velocity between the filter bags at the bottom is very important.

This velocity must be below the suspension velocity of the carbon black particles.

In case the cleaning pulse is failing (not strong enough), this should be noticed

by the excessive contamination of the lower part of the filter bags.

success ■

so it is difficult to make dust collector cleaning efficently ■

!! ■

dear kevinjcg,

The filters I worked with. always worked well, whether with or without venturies.

As long as the filter loading in m/min was OK for the product and the airflow.

Checking with manufacturers and colleagues that operate filters for carbon black is the best way to go in this case.

success ■