Pneumatic Transport Of Batch In A Glass Plant

Posted in: , on 30. Apr. 2003 - 12:53

We are interested in peumatic transportation of the batch in a glass container plant. The total distance is approximately 130 m horizontal and 10 m vertical.5 elbows will be used. The batch is totally dry (max. %0,5 moisture)and with fine particle size.

The raw materials will be weighed in the batch house, then pneumatically transported to the receiving hopper above the mixer. Minor ingredients will be added directly in the mixer, to avoid any loss on the way. Cullet will be added onto the batch after the mixer, before the elevator to the furnace bin.

The quantity of batch to be transported is 500TPD.

I would like to hear about any experience with similar pneumatic transport of batch in glass plants, and problems to be expected and precautions to be taken.

Dennis Hauch - Freeport, TX, USA
(not verified)

Glass Xfer System

Posted on 30. Apr. 2003 - 04:18


There are three factors that, when combined, would say that you are looking at a high-pressure (10 bar) system that will have several steps the conveying pipeline:

1) the instantaneous conveying rate. An average glass processing rate of 500 t/d translates into an instantaneous conveying rate of, say, 30 t/h or more.

2) the bulk density of the conveyed material. It wasn’t stated in your thread but I would estimate it to be something in the area of 2,600 kilograms / cubic meter, very heavy indeed.

3) the horizontal and vertical conveying distance. Though not great in pneumatic conveying terms, it is significant in view of the rate and bulk density of the conveyed material.

It would be important to work with a supplier who is able to conduct pneumatic conveying trials. These trials will determine, for example, if the system must be designed as an external bypass system.

Lastly, this product is likely very abrasive so the system design must be based on minimizing / controlling conveying velocity. Anticipated wear will be a factor when selecting the pipeline material.

These are my thoughts.

Kind regards,

Dennis Hauch

Glass Transfer

Posted on 30. Apr. 2003 - 09:38

Typically, pneumatic convey systems that must transfer an entire weighed batch are best suited for short convey lengths, and for relatively non-abrasive materials. This is because in order to completely purge a convey line, air velocities comparable to dilute phase systems must be attained for a short period of time to completely sweep the pipe of material. If the conveyed material is abrasive, there will be pipe wear. If the convey distance is long, this "short period of time" becomes long, thus increasing wear. i would suggest a different approach in your situation.

The best approach is to pneumatically blend the batch in the batch house, and then transport at low velocity using the "full line concept" TM ( method of pneumatic transport. The "full line concept" method eliminates the need to purge the conveying line, thus dramatically reducing wear on the system. Also, if the batch is blended before transport, there is no worry about leaving material in the convey line after transport.

Dynamic Air Inc. (USA)
(not verified)

Pneumatic Transport Of Glass Batch

Posted on 1. May. 2003 - 09:03

I strongly urge you to consider other conveying options. Pneumatic transfer of a glass batch is difficult and prone to leaving material in the pipe and segregation, especially for container type batch that is granular (greater than 60 mesh), has a high bulk density, is not easily fluidizable, and contains cullet.

My company has experienced problems with pneumatic conveying of glass batches from the weighing process to the mixing process at the furnace. The problems are all those stated above. Only for our glass batches that use fine, easily fluidizable materials (all less than 100mesh) does pneumatic conveying work satisfactorily.

Completeness of batch transfer becomes acceptable only with large amounts of compressed air and long purge times. However, once we achieve acceptably complete material transfer, the wear rate of pipes and elbows increases causing rapid failures and leaks.

My preference for mixtures or combinations of materials that are handled on a batch basis is to not use pneumatic conveying.

Pneumatic Transport Of Batch For Glass

Posted on 2. May. 2003 - 10:02

Dear Mr/Ms Shock,

Thanks for your kind reply.

In our case there is no cullet in the batch.Cullet is added after mixer. So abrasion should not be too much of problem.

Weighed raw materials are planned to be conveyed pneumatically to the mixer.Segregation should not be a problem since will be mixed afterwards. But if there is loss of material, this is a problem.

Bulk density is about 1,5.

Mesh size is on the average around 48,ranging between 32 and 200.

Capacity considered:250 T/12 hours.

So two weighing lines can handle 500 Tons in 12 hours, and if one line has a break down, the other can carry the 500 tons in 24 hours.

Are you still as doubtful for pneumatic transport in our case?

We are of course working on alternative layouts and more conventional transport means as well.

Thank you again.


Isil (Mrs.)

(not verified)

Weighed Glass Batch Transport

Posted on 6. May. 2003 - 04:22

We also mix the batch after transporting weighed batch. The problem we've identified is leaving portions of the weighed batch in the transport lines. The material left in the line is not the same as the overall batch composition and the resulting batch does not make the same glass.

The amount of batch remaining in the line ranges from an unacceptable 400 pounds from a 4000 pound batch to an acceptable 40 pounds from a 4000 pound batch. Your acceptable limits may differ from ours. The amount remaining in the line varies with available compressed air, raw material changes, and transport system settings. For us, the batch house is at the end of the compressed air line and only gets what all the other processes don't use.

Perfect designs of all systems could make pneumatic conveying or weighed batch acceptable. You'll also need very good control of raw materials and system settings.

It seems to me that more conventional transport systems are more forgiving for changes, easier to control, and will give more complete transports all the time.

Dr M Bradley
(not verified)

Wear In Glass Batch Piplines

Posted on 7. May. 2003 - 04:55

This will be an issue even without cullet.

One thing we could do for you would be to measure the erosiveness of the batch, using a sample, then make predictions of the bends lives with various different options of wear resistant materials. This enables you to select an economic option or indeed rule out pneumatics if it is going to be a problem.

Mike Bradley

The Wolfson Centre for Bulk Solids Handling Technology

(not verified)

Pneumatic Conveying-Costs And Problems

Posted on 15. May. 2003 - 10:56

The reasons of choosing the pneumatic system are often following: no dust, no spillage, minimal space requirement, protection of the load and the environment. When conveying products by a pneumatic system there will occur three major problems; high energy costs, wear and segregation. Something that can be avoided by using well proven enclosed belt systems such as pipe conveyor or the Sicon Roulunds system. The initial investment is often lower for pneumatic systems but in the long run the costs are higher than for belt systems. I.e. Sicon have replaced several pneumatic systems in Sweden, Denmark and Norway and can show good results. Visit Internet page for more information.

Best Regards

Robert Olsson

(not verified)

Pneumatic Conveying Of Glass Batch

Posted on 15. May. 2003 - 11:19

I have some experience handling glass batch and cullet in pneumatic lines. The ingredients are highly abrasive, so you need to handle them as slow as possible in a dense phase system and use hardened pipe and elbows.

A company that supplies such equipment and has experience with these materials is:

J.D.B. Dense Flow


Mr. Cam Boothe

Frans van der Zee
(not verified)

Re: Pneumatic Transport Of Batch In A Glass Plant

Posted on 26. Jan. 2005 - 02:26

Dear Sir, If you are considering an enclosed belt system as an alternative for the pneumatic system, you can also choose for the Enerka Becker System of Fenenr Dulop. Our comapny is the licencee for this system.

TYou can find more information of

The english version will be on line soon.

Best regrads

Frans van der Zee

Enclosed Bulk Systems bv

Re: Pneumatic Transport Of Batch In A Glass Plant

Posted on 1. Feb. 2005 - 06:18

Conveying of highly abrasive materials such as glass requires very low velocities and all of the equipment that is erosion-resistant. Both of these are currently available.

But to prevent un-blending, pneumatic conveying systems should not be used to convey dry-blended materials.


Amrit Agarwal


Pneumatic Conveying Consulting

Ph and Fax: 304 346 5125