Dear Soumya,

Your question for pneumatic conveying characteristics is in fact a question for a set of tables, representing the relation between a number of material- and installation parameters.

You mention:

-Pressure drop. The pressure drop can range from low to high

-Air flow. The airflow has to be considered in relation to the pipe diameter, resulting in the air velocity, which is the real primary parameter. The air velocity is material and pipe diameter (Through the Reynoldsnumber) related.

-Solids flow. The solids flow is related by the Solid Loading Ratio to the airflow.

As the airflow is related to the pipe diameter times the air velocity, the solids flow is related to the pipe diameter and the air velocity. Moreover, the SLR is related to the conveying length (horizontally, vertically and number of bends)

See:

Pneumatic conveying, an unexpected relationship.

https://news.bulk-online.com/?p=445

A table representing the “pressure drop vs air flow diagrams for different solids flow rates” would become a multi dimensional array of figures for various materials, which is almost undoable to calculate and verify.

And if you have the computer program to calculate such tables, at the same time it is not necessary anymore, because it is then much easier to calculate your specific case.

Your statement that you have experience with Australian fly ash of different properties must enable you to define the differences in those properties and translate them to the Indian fly ash.

The defined property values are then also valid for your used calculation method.

The difference in conveying properties are not country related but fuel related and how efficient the burning process and the ESP works.

Contact Indian power stations and ask them for their fly ash installation lay outs and performances.

Success

Teus ■

Originally Posted by Teus Tuinenburg

Dear Soumya,

Your question for pneumatic conveying characteristics is in fact a question for a set of tables, representing the relation between a number of material- and installation parameters.

You mention:

-Pressure drop. The pressure drop can range from low to high

-Air flow. The airflow has to be considered in relation to the pipe diameter, resulting in the air velocity, which is the real primary parameter. The air velocity is material and pipe diameter (Through the Reynoldsnumber) related.

-Solids flow. The solids flow is related by the Solid Loading Ratio to the airflow.

As the airflow is related to the pipe diameter times the air velocity, the solids flow is related to the pipe diameter and the air velocity. Moreover, the SLR is related to the conveying length (horizontally, vertically and number of bends)

See:

Pneumatic conveying, an unexpected relationship.

https://news.bulk-online.com/?p=445

A table representing the “pressure drop vs air flow diagrams for different solids flow rates” would become a multi dimensional array of figures for various materials, which is almost undoable to calculate and verify.

And if you have the computer program to calculate such tables, at the same time it is not necessary anymore, because it is then much easier to calculate your specific case.

Your statement that you have experience with Australian fly ash of different properties must enable you to define the differences in those properties and translate them to the Indian fly ash.

The defined property values are then also valid for your used calculation method.

The difference in conveying properties are not country related but fuel related and how efficient the burning process and the ESP works.

Contact Indian power stations and ask them for their fly ash installation lay outs and performances.

Success

Teus

Just to add in this thread

Mr S.S.Mallick , indeed there is substantial difference between chemical behaviour of ASH for both the countries . Well , the indian ash high silica than austrlian ash and could be the part of the reason , we SLR ratio is considerable low than australian ash

If i have to put assess the behaviour of difference ash source perhabs , i would collect the ash a below source and carry out the discrete element model for below source

1) Indian washery coal

2) Indian non washery coal

3) Mix coal with australian coal

Mr Teus , may i request you to kindly give us the right path to follow . If to want to conduct teh objective as stated by mr MALLICK . ■

Dear kj,

My first advice would be: Contact Indian power stations and Australian power stations and ask them for their fly ash installation lay outs and performances.

Also ask them to inform you about the fuel (Coal, Oil, wood, etc.) origin, grades and properties.

Then use your calculation method to correlate the pneumatic conveying characteristics.

(Material loss factor, velocities)

The standard method.

Best regards

Teus ■

Originally Posted by Teus Tuinenburg

Dear kj,

My first advice would be: Contact Indian power stations and Australian power stations and ask them for their fly ash installation lay outs and performances.

Also ask them to inform you about the fuel (Coal, Oil, wood, etc.) origin, grades and properties.

Then use your calculation method to correlate the pneumatic conveying characteristics.

(Material loss factor, velocities)

The standard method.

Best regards

Teus

Sir

There is a technology of ash conveying by pipe conveyor . Can i have your view on this tech . I am skeptical if pipe conveyor is being used for coal conveying , why cant it be used in ash conveying

Any limitation ? ■

Dear kj,

You quoted my post and asked about the application of a pipe conveyor.

However, I have no practical knowledge nor experience in the pipe conveying technology.

Therefore, I refrain from answering your post.

Success

Teus ■

I know a little about "Fly Ash" that may offer some additional info to the collection of what is known or needs to be known:

1. "Fly Ash", I assume, means it is easily airborne with mild pneumatic current and is often classified as floatable, meaning hollow, and is separated in water vs. very small sizes which can fly and also sink in water.

2. Fly Ash comes in many varieties depending on the coal source and the power plant flue gas precipitators

3. Fly Ash sometimes has a hollow interior and can also have a perforated surface verses most with solid individual or agglomorated spheres and star shapes. Hollow structure (centospheres?) is prized for special filler applications. It demands a premium price.

4. Fly Ash size distribution as well as structure and shape can vary

5. Fly Ash can have varying surface chemistry and residual materials

6. Smaller sizes may also be influenced by Einstonian, Van Der Waahl, and Zeta Potential attractions, independent of their hollow structure, size distribution, and surface chemistry.

7. The specific gravity can vary and bulk density can also vary depending on size, structure and shape.

8. With the above comments the Reynolds Number varies leading to differences in pneumatic transport specifications that need to be characterized for accurate engineering of the transport design.

9. Some ash residual surface materials can be sensitive to temperature. The main ash content is Silica with varying degrees of Alumina and other metals bonded together. Residual materials form on the surface during precipitation from gas to solid depending on the coal properties.

10. I believe hollow sphere ash formation is not well known. If it can be formed with scientific certainty then someone might become quite rich. It has the potential for improving the properties of rubber, cement, paints, plastics, et al.

11. We have an interest in modeling the formation using SPH or its derivitive, including phase transformation. Thus, the precipitator circuit design and thermal dynamic properties may lead to controlling hollow sphere formation. If anyone wishes to discuss the above, please contact the undersigned. ■