Originally Posted by Teus Tuinenburg

Dear Michal Seifert,

The pressure drop, caused by the acceleration of material is given as:

dp=1/2SLRrhogas/g(velocity(n+1)^2velocity(n)^2)

As the velocity increases along the pipeline, due to air expansion, the pressure drop for kinetic energy also increases along the pipeline.

At a diameter increase, in case of a stepped pipeline, some energy is regained from the material kinetic energy.

At the same time, a particle is constantly falling in the air flow, due to gravity.

This “falling velocity energy” has to be accounted for also.

The formula, W=Vp/4640 is a different form of the formula I gave above.

Edited to make the formula understandable ■

Originally Posted by Teus Tuinenburg

Dear Michal Seifert,

The pressure drop, caused by the acceleration of material is given as:

dp=1/2SLRrhogas/g(velocity(n+1)^2velocity(n)^2)

As the velocity increases along the pipeline, due to air expansion, the pressure drop for kinetic energy also increases along the pipeline.

At a diameter increase, in case of a stepped pipeline, some energy is regained from the material kinetic energy.

At the same time, a particle is constantly falling in the air flow, due to gravity.

This “falling velocity energy” has to be accounted for also.

The formula, W=Vp/4640 is a different form of the formula I gave above.

Edited to make the formula understandable ■

Hello Amrit,

I am working on design on dilute and dense phase vacuum conveying systems. I need help in calculating pressure losses in case of dense phase vacuum transfer. I have searched online but i'm not able to find a standard method to do it.

Also it will be great if you can mail me the article on design of dilute phase conveying systems.

my email id: puskar36@gmail.com

Thanks in advance.

Regards,

Puskar

Originally Posted by Amrit Agarwal

My article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" was published this month in Powder Handling and Processing magazine. This article gives an easy to use Excel-based calculation method for designing new dilute phase pneumatic conveying systems or for improving the performance of existing conveying systems.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting Services

Email: polypcc@aol.com

Ph and Fax: 304 346 5125

Picture added by Adinistrator as an example:

■

Hello Amrit,

I am working on design on dilute and dense phase vacuum conveying systems. I need help in calculating pressure losses in case of dense phase vacuum transfer. I have searched online but i'm not able to find a standard method to do it.

Also it will be great if you can mail me the article on design of dilute phase conveying systems.

my email id: puskar36@gmail.com

Thanks in advance.

Regards,

Puskar

Originally Posted by Amrit Agarwal

My article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" was published this month in Powder Handling and Processing magazine. This article gives an easy to use Excel-based calculation method for designing new dilute phase pneumatic conveying systems or for improving the performance of existing conveying systems.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting Services

Email: polypcc@aol.com

Ph and Fax: 304 346 5125

Picture added by Adinistrator as an example:

■

Dear Amrit,

Can you send me a copy of the article where in you have given Excel based calculation method for pneumatic conveying.

My email id : ujjwalchowdhury19@gmail.com

Thanks

Ujjwal Chowdhury

Originally Posted by Amrit Agarwal

My article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" was published this month in Powder Handling and Processing magazine. This article gives an easy to use Excel-based calculation method for designing new dilute phase pneumatic conveying systems or for improving the performance of existing conveying systems.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting Services

Email: polypcc@aol.com

Ph and Fax: 304 346 5125

Picture added by Adinistrator as an example:

■

Dear Amrit,

Can you send me a copy of the article where in you have given Excel based calculation method for pneumatic conveying.

My email id : ujjwalchowdhury19@gmail.com

Thanks

Ujjwal Chowdhury

Originally Posted by Amrit Agarwal

My article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" was published this month in Powder Handling and Processing magazine. This article gives an easy to use Excel-based calculation method for designing new dilute phase pneumatic conveying systems or for improving the performance of existing conveying systems.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting Services

Email: polypcc@aol.com

Ph and Fax: 304 346 5125

Picture added by Adinistrator as an example:

■

Dear Mr. dungnguyen,

I noticed your request on the bulk online forum for the article od Mr. Agarwal.

From your private message on the bulk online forum, you share some extra information.

Material fly ash (no pneumatic conveying properties given).

Conveying length approx. 100 m (not differentiated in horizontal length and vertical length and number of bends)

Your guesses are a pipeline diameter of 4” or 5” or 6”.

The compressor volume is selected at 60 m3/min. (for all 3 pipe diameters?)

The required capacity is set at 300 tph.

A first indicative calculation shows:

6” pipeline performs 60 tph at 2.5 barg

5” pipeline performs 48 tph at 2.5 barg

4” pipeline performs 29 tph at 2.5 barg

The selected (guessed) pipeline diameters are far too small to reach the required 300 tph.

If this is a serious project, then my advise is to contact your local Atlas Copco agent to for professional support or send a request to simon.van.rompaey@atlascopco.com Antwerp, Belgium. ■

Dear Mr. dungnguyen,

I noticed your request on the bulk online forum for the article od Mr. Agarwal.

From your private message on the bulk online forum, you share some extra information.

Material fly ash (no pneumatic conveying properties given).

Conveying length approx. 100 m (not differentiated in horizontal length and vertical length and number of bends)

Your guesses are a pipeline diameter of 4” or 5” or 6”.

The compressor volume is selected at 60 m3/min. (for all 3 pipe diameters?)

The required capacity is set at 300 tph.

A first indicative calculation shows:

6” pipeline performs 60 tph at 2.5 barg

5” pipeline performs 48 tph at 2.5 barg

4” pipeline performs 29 tph at 2.5 barg

The selected (guessed) pipeline diameters are far too small to reach the required 300 tph.

If this is a serious project, then my advise is to contact your local Atlas Copco agent to for professional support or send a request to simon.van.rompaey@atlascopco.com Antwerp, Belgium. ■

Dear Mr. dungnguyen,

Is this a serious project for you to learn or is it a serious project, which will be executed?

If the conveying length of this system is the same system, which I calculated 100m horizontal, 40 m vertical and 20 bends, there is a difference in calculated capacity and claimed capacity.

Due to insufficient data, it is not possible to find the cause of the difference.

I calculated for 4 6” pipelines a combined capacity of 4 x 60 = 240 tph. (Then you need 4 separate tanks and 4 compressors)

Again, the calculated capacity is a preliminary one and not reflecting a final design.

From the picture in your thread, I assume that the project concerns a fly ash tanker barge with one horizontal pressure tank with a working pressure of 2.5 barg.

Operating 1 pressure tank with 4 outlets is not a stable situation.

If one of the outlets is not conveying fly ash, the other outlets lose the airflow and get choked.

Then you have multiple, 100 m long problems.

Designing a pneumatic conveying system requires in depth knowledge how a system functions in all stages and calculations require software, based on the understanding of the physical laws (gas laws, Newton, thermodynamics, conservation of energy, flow dynamics and the mathematical description of all those physics)

The calculation is not in Excel. The software is not available on the market.

Again, if this is a serious project to be executed, then my advice is to contact your local Atlas Copco agent to for professional support or send a request to simon.van.rompaey@atlascopco.com Antwerp, Belgium. ■

Dear Mr. dungnguyen,

Is this a serious project for you to learn or is it a serious project, which will be executed?

If the conveying length of this system is the same system, which I calculated 100m horizontal, 40 m vertical and 20 bends, there is a difference in calculated capacity and claimed capacity.

Due to insufficient data, it is not possible to find the cause of the difference.

I calculated for 4 6” pipelines a combined capacity of 4 x 60 = 240 tph. (Then you need 4 separate tanks and 4 compressors)

Again, the calculated capacity is a preliminary one and not reflecting a final design.

From the picture in your thread, I assume that the project concerns a fly ash tanker barge with one horizontal pressure tank with a working pressure of 2.5 barg.

Operating 1 pressure tank with 4 outlets is not a stable situation.

If one of the outlets is not conveying fly ash, the other outlets lose the airflow and get choked.

Then you have multiple, 100 m long problems.

Designing a pneumatic conveying system requires in depth knowledge how a system functions in all stages and calculations require software, based on the understanding of the physical laws (gas laws, Newton, thermodynamics, conservation of energy, flow dynamics and the mathematical description of all those physics)

The calculation is not in Excel. The software is not available on the market.

Again, if this is a serious project to be executed, then my advice is to contact your local Atlas Copco agent to for professional support or send a request to simon.van.rompaey@atlascopco.com Antwerp, Belgium. ■

Dear Mr. dungnguyen,

Assume that you have 4 parallel lines operating from one common pressure tank.

And assume that the 4 pipelines have the same diameter, horizontal length, vertical length and the same number of bends.

The 4 pipelines will convey the equal amount of fly ash because the conveying pressure for all pipelines is equal and the airflow is equally divided over the pipelines.

If the feeding of one of the pipelines is changing (f.i. an irregular feeding flow or one pipeline is not getting any fly ash at all, because that section is empty) then the 4 pipelines still experience the same tank pressure.

But the requirement of equal airflow for the 4 pipelines can no longer be met.

The pipeline which is not getting any fly ash feeding becomes an open line with a low airflow resistance and draws all the air, leaving not enough air for the other lines.

In the other lines the airflow drops and the air velocity in those lines reduce to a level that the fly ash can no longer be kept in suspension, resulting in a full choke.

This is not a situation that can be solved by mathematics. ■

Dear Mr. dungnguyen,

Assume that you have 4 parallel lines operating from one common pressure tank.

And assume that the 4 pipelines have the same diameter, horizontal length, vertical length and the same number of bends.

The 4 pipelines will convey the equal amount of fly ash because the conveying pressure for all pipelines is equal and the airflow is equally divided over the pipelines.

If the feeding of one of the pipelines is changing (f.i. an irregular feeding flow or one pipeline is not getting any fly ash at all, because that section is empty) then the 4 pipelines still experience the same tank pressure.

But the requirement of equal airflow for the 4 pipelines can no longer be met.

The pipeline which is not getting any fly ash feeding becomes an open line with a low airflow resistance and draws all the air, leaving not enough air for the other lines.

In the other lines the airflow drops and the air velocity in those lines reduce to a level that the fly ash can no longer be kept in suspension, resulting in a full choke.

This is not a situation that can be solved by mathematics. ■

We have stored Non hygroscopic, self compacting, dry powder (fly ash) (Bulk Density-800 kg / cum) and ( 0 to 200 micron - d50=45 micron) in Bulk bag - 1000 kg

We have 9 cubic meter hopper. We are using hoist to lift bulk bag and pneumatic massager to empty bulk bag in the hopper.

Below the 9 cubic meter hopper we have a BLOW THROUGH VALVE (350 MM ROTOR DIA) 130 mm pipe line.

The material conveying pipe line has 6 bends, 23 meter vertical distance and 28 meter horizontal distance.

We have connected Hyva blower (Centrifugal) of 850 cum and + 1 kg/sq. cm pressure. Motor 37 kw.

Hyva air is connected to the Blow through valve.

The material is not getting conveyed.

First 5 meter pipe is 130 mm, then there is 4 meter long flexible hose of 140 mm, rest is the 150 mm pipe line. Bends are 5d with DRC wear lining

Expected conveying rate is 10 TPH.

What is the problem of system design?

Is the pressure of the blower correct?

Is the air flow of the blower sufficient?

Is the material conveying line design a problem?

What are the possible solutions to make it operational.

Vipin Dave

vipindave1851@gmail.com

Ahmedabad, India ■

We have stored Non hygroscopic, self compacting, dry powder (fly ash) (Bulk Density-800 kg / cum) and ( 0 to 200 micron - d50=45 micron) in Bulk bag - 1000 kg

We have 9 cubic meter hopper. We are using hoist to lift bulk bag and pneumatic massager to empty bulk bag in the hopper.

Below the 9 cubic meter hopper we have a BLOW THROUGH VALVE (350 MM ROTOR DIA) 130 mm pipe line.

The material conveying pipe line has 6 bends, 23 meter vertical distance and 28 meter horizontal distance.

We have connected Hyva blower (Centrifugal) of 850 cum and + 1 kg/sq. cm pressure. Motor 37 kw.

Hyva air is connected to the Blow through valve.

The material is not getting conveyed.

First 5 meter pipe is 130 mm, then there is 4 meter long flexible hose of 140 mm, rest is the 150 mm pipe line. Bends are 5d with DRC wear lining

Expected conveying rate is 10 TPH.

What is the problem of system design?

Is the pressure of the blower correct?

Is the air flow of the blower sufficient?

Is the material conveying line design a problem?

What are the possible solutions to make it operational.

Vipin Dave

vipindave1851@gmail.com

Ahmedabad, India ■

Dear Vipin Dave,

Design is 34 tph at 0.236 m3/sec at 1 bag (at sea level)

Depends on the blower characteristic. (could not find that on the internet)

Is the blower characteristic given as:

850 cum at 0 barg

And

0 cum at 1 barg

No, the material conveying line design is not a problem.

It seems that the rotary valve is over feeding the system and that the blower curve delivers not enough air flow at 1 barg

A PD blower is a better choice than a centrifugal fan, due to the respective characteristics.

A VFD drive on the rotary valve from zero to maximum and probably a smaller blower. ■

Dear Vipin Dave,

Design is 34 tph at 0.236 m3/sec at 1 bag (at sea level)

Depends on the blower characteristic. (could not find that on the internet)

Is the blower characteristic given as:

850 cum at 0 barg

And

0 cum at 1 barg

No, the material conveying line design is not a problem.

It seems that the rotary valve is over feeding the system and that the blower curve delivers not enough air flow at 1 barg

A PD blower is a better choice than a centrifugal fan, due to the respective characteristics.

A VFD drive on the rotary valve from zero to maximum and probably a smaller blower. ■