Powder transfer by using the pressure drop

Posted in: , on 24. Dec. 2004 - 10:34

Hi everyone...

We're testing pp powder whose bulk density is 0.46g/cc transferring system by using the pressure drop. There is no transferring gas such as nitrogen or air. We'll just use the pressure drop between reactor and powder separator which is about 16.7Kg/cm2.G. Reactor level is controlled automatically by LCV (level control valve). Regarding the system concept, refer to the attached pfd.

At this moment, I have some concerns about the vibration and size of powder transfer line. Is there any good suggestion to operate our system safely?

System Condition

- Reactor Pressure: 17.0Kg/cm2.G

- Reactor Temperature: 80¡

- Separator Pressure: 0.3 Kg/cm2.G

- Separator Temperature: 75¡

- Target transfer rate: 16.5 T/Hr

- Reactor outlet nozzle: 1 inch

- Line size

. Powder: 2 inches

. Vent: 1 inch

Many thanks.

Transfer From Reactor

Posted on 12. Dec. 2004 - 01:03

17 tons per hr transfer rate in a 2 inch line using pressure drop from reactor to dust collector.

at 80 or 800 or so degrees c of temperature.

Of something called pp.

no feeder only overflow .

no ventury .

I cannot see any problem to achieve your goal.

No distance was specified and no additional rise either.

So in general-

with your pressure drop you can transfer almost anything to anywhere.wth almost any size pipeline.

If I read the problem right the question will be to design the proper overflow weir to achieve apropiate re entrainment with the reactor wate gas, to keep a stable transport without disturbing the reactor itself.

Can you attach a sketch ?.

With that required pressure drop the problem can be, wear in the transfer pipeline.

Regards

marco

TECMEN Consultant in: Sponge Iron (DRI) handling Sponge Iron DRI Automated Storage Firefighting and Root Cause Analysis Pneumatic Conveying Consultants Phone 5281 8300 4456.

Re: Powder Transfer By Using The Pressure Drop

Posted on 12. Dec. 2004 - 02:23

The design that you have described will not work. At a rate of 16.5 tons/hr you will get compaction of the material above the one inch outlet nozzle of the reactor. Also, unless you control the reactor pressure, conveying velocity in the 2 inch pipeline will be very high.

Regards,

A. T. Agarwal

Consultant

Pneumatic Conveying Technologies

polypcc@aol.com

Ph and Fax: 304 346 5125

Conveying Capacity.

Posted on 15. Dec. 2004 - 06:51

Dear friends

I must admit I am not faniliar with your instalation , So I if i might guess. Your reactor pressure is controlled by your recirculation gas bleed and makeup.

2.- the transport line is either a closed loop or part of the bleed.

If it si part of a closed loop you have some sort of lock bin before the solids discharge.

3.- if it is part of the bleed you have to generate the pressure drop in the transport line , that is the reason for the small diameter pipe.

4.- strating and stopping the transport line will create a transient in your reactor that has alrready taken acount for.

5´.- or you start your transport a as you start your reactor. then the initial product conveyed is raw , unreacted material or you leave a heel for startup.

I traditionally would have the bleed after the dust collector to keep my system pushing the conveying line, this is apart fron any other bleed point , this is an additional bleed , you split the bleed .

the bleed controll will be the conveying controll parameter. and the reactor solids overflow , if this is a fliudized reactor then your feed rate.

By any chance are you from SIDBEC BOSCO?

Marco

TECMEN Consultant in: Sponge Iron (DRI) handling Sponge Iron DRI Automated Storage Firefighting and Root Cause Analysis Pneumatic Conveying Consultants Phone 5281 8300 4456.
Pierre Labourt-Ibarre, France
(not verified)

Re: Powder Transfer By Using The Pressure Drop

Posted on 26. Dec. 2004 - 09:09

Dear Sir,

I did not get the pdf skectch. Where is it?

In order to convey there must be some conveying gas otherwise I do not see how the solids can travel.

Now, from the numbers assuming the Solids can travel at their bulk density (in this case 0.46 gm/cm^3), in a 2" line, the superficial velocity is quite decent, 5 m/s.

That's a very minimum since any additional conveying gas will make the flowing density lighter and the velocity accordingly higher.

As you say, the question is at the start.

Can't you throttle at the end of the line when getting in the separator?

Best Regards,

Pierre

Re: Powder Transfer By Using The Pressure Drop

Posted on 27. Dec. 2004 - 01:49

Thanks for your interests.

Actually I attached one electric file which was made by bmp and file size is just only 220kilobite. But I couldn't find that after registering my article.

I'll find out why it happened and reattach another one in the very near future.

Concerning the conveying gas, it is a process gas which is mainly propylene. My meaning which is not using carrier gas such as nitrogen or air was that we just didn't use external gas. In other words, pp powder was transferred by process gas (vapor propylene) and delta pressure of the two points.

To dear: organizer of this forum

Would you make me clear why my attachment was not seen after registering my article?

Many thanks.