Surri,

If you want to do this yourself, you have a steep learning curve. Get a copy of "Industrial Ventilation" (referenced frequently in this Forum) published by the American Conference of Governmental Industrial Hygienists.

Much quicker to get three competetive quotations from competent baghouse suppliers. They will know how to design the ducting and size the baghouse and fan. And, most importantly, you will know pretty well the final cost.

Michael Reid. ■

Hi Surry,

Fair questions. We are not all experts, but we need to know a few things before we talk to the Vendors.

You are dealing with two different products - Hametite and Bauxite. Each has different dusting characteristics, and will need separate equipment.

1. How may connection is possible for one dust collector? - as many as you need - 20 to 30 may be normal

2.Is it based on dust concentration??????? Yes and no. In a dust collection application the concentration of dust in the air is low [it is not a lean phase conveying problem, as you would have in a calciner]. The more dust you have the more frequently you will have to pulse the bags. Bag selection is based on the AVERAGE dust concentration of all the nozzles. You will need to discuss this with your Vendor.

3. How much flow rate, Static Pressure required to collect 1 gm of Dust? - irrelevant. The main danger is settlement of dust in the ducts. For this reason ducting is designed for a minimum air velocity of about 20 m/s.

4.Any relation is there with dust size? - In dust collection terms a 100 micron particle is a 'brick'. It will quickly drop out of the air, and should be allowed to be carried away on the belts. Larger particles should be considered as spillage, and not dust, and treated accordingly [remember you are basically dealing with an industrial vacuum cleaner]. Trying to pick up heavy particles will cause problems in the bags, and cost the earth.

5.Design based on no. of connections or based on dust? - Base your design on the required number of connections. Let the Vendor sort out the dust question at the dust collector.

6.Which type of bag is better? - You don't have a dust explosion problem. Get your Vendor to give you a recommended alternatives.

7.How to calculate the bag house is working efficiently or not? (I know to calculate the dust collector fans efficiency) - filter bags are 99.5% efficient. The more dust on the bag, the higher is the filtering efficiency. But at the same time, the pressure drop increases so you draw more power, and the air flow drops. If the pressure loss is too high the operators will have to change the bags. The Vendor can explain that to you.

8 Have you ever tried to vacuum a carpet with a hose that has a hole in it? or allows air to leak in? You just can't get enough suck at the end of the hose. The same thing happens if you allow 2 outlets to be open. You need slide-gates [slide-valves] to balance the air, so that just the right amount of air comes from each outlet, and you have enough suck left at the end of the ducting.

An Industrial Ventilation Manual will show you how to design ducting, but it won't tell you how much air to suck from each chute enclosure. For that you need someone with experience - and there is a wide variation of opinion about this out there.

It depends on the size of the application. A small box with a few outlets can be handled by discussion with Vendor. For a large application, say $1 mil capital cost it would pay to appoint a dust control consultant.

I will post a typical calculation spreadsheet on www.cospire.com

Regards - John.rz

Sustainable Technology http://www.cospire.com/browse.aspx?id=4325

Conveyor Calculation http://www.cospire.com/browse.aspx?id=4317 ■

Hello Surri,

You really got goods ideas.

We are dust collector designer and producer. Our factory makes nonwoven needle felt, filter bags, and we offer whole dust collecting system to customers too.

If you need design or quotation, pls contact me.

Best regards,

Sophie

Shanghai BG Filtech Co.,LTD.

Tel:+86 21 54893777 Ext. 255

Fax:+86 21 54893772

Mobile: +86-13601851502

Email:ycxsophie@hotmail.com,sophie@bgfiltech.com

www.bgfiltech.com

1106,No 9, Lane 300, East Nandan Rd, Shanghai, 200030, China. ■

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