You will need an pneumatic injection system to give a controlled feed into the furnace. These systems have accuracies of 1% and can work at high pressures. They are pretty standard in Iron and steel making industry. Do a Google search and you will find number of reputable vendors. ■

Originally Posted by Author

Hi Sir,

I'm Anizan Wan Ramli, mechanical engineer at Perwaja Steel Sdn Bhd (Malaysia).

Basically, at perwaja steel sdn bbhd mostly used pneumatic conveying system to transfer coke/carbon material into the furnace. However, there were some problem occured during transfer that material. As we know, there were some factors provide for this problem such as pressure drop, bending, density of particles and others.

Here, I want to ask your opinion or suggestion base to your experienced and knowledge in pneumatic conveying system. How to control the constantly the flow of material transfered into the furnace (target 25-30 kg/min).

So, I so appreciate if you share your knowlege and experienced in order to solve my problem.

Thank you...

Dear Mr. Ramli,

From your questions it seems that you are not able to get a controlled feed rate of the materials you are feeding into the furnace. With the limited information you have given it is difficult to give you a good answer. But I will try.

Conveying rate of a pneumatic conveying system will depend upon the feed rate unless it is limited by the conveying pressure that is generated. Feeding is mostly done by a blow tank or by a rotary valve. In your case I guess it is a blow tank. Feed from a blow tank is controlled by using a control valve at its bottom outlet. The open area of this valve and the pressure in the tank are then controlled to get the required feed rate. Feed problems typically arise if these two items are not correctly designed or operated.

You may contact me for any further help.

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

email: polypcc@aol.com ■

Dear Anizan Wan Ramli,

Are you aiming at just a continuous, precise, conveying rate or should the system also be controllable at various feeding rates.

In addition, your thread is unclear about whether it is one pneumatic system with one injection point or one pneumatic system with multiple injection points.

A feeder gravimetrical feeder system is shown in:

http://www.flsmidth.com/~/media/PDF%...GBDRW0112.ashxIB01000eGBDRW0112.ashx

Dear Mario,

Is this considered accurate or inaccurate?

Theory:

100% accurate = 0% inaccurate

or:

100% accuracy = 100% +/- 0% inaccuracy

accuracy = 100% +/- inaccuracy

As you state an accuracy of less than 3%,

the equation becomes:

3% accuracy = 100% +/- 97% inaccuracy

Probably, you meant an inaccuracy of +/- 3 %

Merry X-mass and a prosperous 2013 to all of you.

Take car

Teus ■

I posted a reply before to this thread, but that came apparently not through. Therefore a second attempt.

Dear Anizan,

Obviously, you are referring to the question “How to control the feeding of a pneumatic conveying system”. Probably an injection system.

In your thread, you do not describe the existing installation and it is also not clear whether the control is meant to be at maximum rate only or to be regulated at various rates.

Nor the number of the number of possible injection points is mentioned.

More info about the existing installation and the furnace process (f.i. fluctuating back pressures in the furnace) is needed for an appropriate reply

Dear Mario,

Probably you meant We dose 1,2-5,2 t/h with an inaccuracy of < 3%.

Theory:

100% accuracy = 0% inaccuracy

0% accuracy = 100 % inaccuracy

Obviously:

100% accuracy = 100% accuracy - 0% inaccuracy

example:

97% accuracy = 100% accuracy - 3% inaccuracy

or

3% accuracy = 100% accuracy - 97% inaccuracy

Have a nice time

Teus ■