Dear Armit,

I already request your article with reply on this thread and e-mail.

And reply for your e-mail with answers but I didn't receive any mail.

Could you check your e-mail box dated oct. 29 ?

I am still very interesting to your article.

engin.j.kim@gmail.com ■

Dear Armit,

I already request your article with reply on this thread and e-mail.

And reply for your e-mail with answers but I didn't receive any mail.

Could you check your e-mail box dated oct. 29 ?

I am still very interesting to your article.

engin.j.kim@gmail.com ■

Dear. Mr Amrit Agarwal.

Thank you amrit for you good article.

It is impressive and I'll contact you if there happens question.

Thanks! ■

Dear. Mr Amrit Agarwal.

Thank you amrit for you good article.

It is impressive and I'll contact you if there happens question.

Thanks! ■

Dear Mr. Amrit Agarwal,

Thank you very much for sending the article on "theory and design of dilute phase pneumatic conveying systems". I found your article very useful. It is a good article that puts forth a practical hands-on approach.

Thank you once again for your time and co-operation.

Warm Regards

A Kaushik ■

Dear Mr. Amrit Agarwal,

Thank you very much for sending the article on "theory and design of dilute phase pneumatic conveying systems". I found your article very useful. It is a good article that puts forth a practical hands-on approach.

Thank you once again for your time and co-operation.

Warm Regards

A Kaushik ■

A. T. Agarwal’s paper “Theory and Design of Dilute Phase Pneumatic Conveying Systems” (2005 Powder Handling & Processing) is a best introduction to the subject that I’ve found.

Useful information on this subject is difficult to obtain. This paper provides a practical method of calculation as well as an explanation.

JD ■

A. T. Agarwal’s paper “Theory and Design of Dilute Phase Pneumatic Conveying Systems” (2005 Powder Handling & Processing) is a best introduction to the subject that I’ve found.

Useful information on this subject is difficult to obtain. This paper provides a practical method of calculation as well as an explanation.

JD ■

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

i can answer you question, you can contact me by the folling:

derek@airslide.net ■

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

i can answer you question, you can contact me by the folling:

derek@airslide.net ■

Dear Mr. Amrit T. Agarwal,

I would like a copy of your article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" along with the Calculation Sheet.

Thanks in advance.

Regards,

Carlos Di Yorio

EDT Ingeniera

carlosdiyorio@edtingenieria.com ■

Dear Mr. Amrit T. Agarwal,

I would like a copy of your article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" along with the Calculation Sheet.

Thanks in advance.

Regards,

Carlos Di Yorio

EDT Ingeniera

carlosdiyorio@edtingenieria.com ■

Dear Mr. Amrit Agarwal,

I'd like a copy of your article too.Pls also send me the calculation sheet for "Theory and Design of Dilute Phase Pneumatic Conveying Systems".

Ty in advance.

Amin Bagheri

email: amin@bagheri.biz ■

Dear Mr. Amrit Agarwal,

I'd like a copy of your article too.Pls also send me the calculation sheet for "Theory and Design of Dilute Phase Pneumatic Conveying Systems".

Ty in advance.

Amin Bagheri

email: amin@bagheri.biz ■

Dear Mr. Amrit Agarwal,

I'd like a copy of your article too. Please also send me the calculation sheet for "Theory and Design of Dilute Phase Pneumatic Conveying Systems". Please send to rapee1966@gmail.com

Thank you very much

Rapee ■

Dear Mr. Amrit Agarwal,

I'd like a copy of your article too. Please also send me the calculation sheet for "Theory and Design of Dilute Phase Pneumatic Conveying Systems". Please send to rapee1966@gmail.com

Thank you very much

Rapee ■

Dear Mr.Amrit Agarwal,

I am new to pneumatic transport system.

I would like to have a copy of your article “Theory and Design of Dilute Phase Pneumatic Conveying Systems”.

Please send it to anand.rajendran@flsmidth.com

Thanks and Regards

Anand■

Dear Mr.Amrit Agarwal,

I am new to pneumatic transport system.

I would like to have a copy of your article “Theory and Design of Dilute Phase Pneumatic Conveying Systems”.

Please send it to anand.rajendran@flsmidth.com

Thanks and Regards

Anand■

I recently received the article "Theory and Design of Dilute Phase Pneumatic Conveying" from Mr. Agarwal and it was just the information that I needed to understand and perform calculations on pneumatic conveying! The information is straight forward, simple, and easily compatible with Excel if you have the basic spreadsheet skills. I would recommend this to anyone doing pneumatic conveying design.

Thanks again Mr. Agarwal!

Kyle Kuhling ■

I recently received the article "Theory and Design of Dilute Phase Pneumatic Conveying" from Mr. Agarwal and it was just the information that I needed to understand and perform calculations on pneumatic conveying! The information is straight forward, simple, and easily compatible with Excel if you have the basic spreadsheet skills. I would recommend this to anyone doing pneumatic conveying design.

Thanks again Mr. Agarwal!

Kyle Kuhling ■

Dear Mr.Agarwal,

I am interested in your article "Theory and Design of Dilute Phase Pneumatic Conveying"

Please forward me the same.

Thanks in advance.

anandindia86@gmail.com ■

Dear Mr.Agarwal,

I am interested in your article "Theory and Design of Dilute Phase Pneumatic Conveying"

Please forward me the same.

Thanks in advance.

anandindia86@gmail.com ■

I have earlier done the calculation based on the article Penumatic Convey Design at www.cheresourses.com which was based on this article. I see this article is more detailed and hopefully I can with help of this article find out whats wrong with our conveyour system or prove that it is not our system but the 3rd party surge tank having backpressure.

Thomas Hovden ■

I have earlier done the calculation based on the article Penumatic Convey Design at www.cheresourses.com which was based on this article. I see this article is more detailed and hopefully I can with help of this article find out whats wrong with our conveyour system or prove that it is not our system but the 3rd party surge tank having backpressure.

Thomas Hovden ■

Dear Mr. Amrit T. Agarwal,

Thank you for providing me with your article.

It really gave me a good stepping stone to understand the basics of pneumatic conveying. It's is quite detailed, down to the point explaining the meanings of each part of the formula.

Some comments:

a) Will be attempting to prepare a worksheet next.

b) Since I am a metric units user, with some knowledge i am still able to convert the units to metric.

c) I learned that forgetting some basic things are lethal, like what is the meaning of the number "144g" in the flanning friction factor when using imperial (4f.L.p.V2)/(2g.D.144) versus metric 4f.(LV2)/(2D). (V2 is V squared) Anyone can provide some advice on this?

All and all, thank you again for this article.

Regards,

Yong Tze Shoong ■

Dear Mr. Amrit T. Agarwal,

Thank you for providing me with your article.

It really gave me a good stepping stone to understand the basics of pneumatic conveying. It's is quite detailed, down to the point explaining the meanings of each part of the formula.

Some comments:

a) Will be attempting to prepare a worksheet next.

b) Since I am a metric units user, with some knowledge i am still able to convert the units to metric.

c) I learned that forgetting some basic things are lethal, like what is the meaning of the number "144g" in the flanning friction factor when using imperial (4f.L.p.V2)/(2g.D.144) versus metric 4f.(LV2)/(2D). (V2 is V squared) Anyone can provide some advice on this?

All and all, thank you again for this article.

Regards,

Yong Tze Shoong ■

I've just tried Amrit's calcultion method and it seems to work very nicely. We are developing a coal treatment system for which pneumatic conveying is axiomatic. I'm looking forward to running some 'What if' scenarios using his calcs.

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

■

I've just tried Amrit's calcultion method and it seems to work very nicely. We are developing a coal treatment system for which pneumatic conveying is axiomatic. I'm looking forward to running some 'What if' scenarios using his calcs.

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

■

Dear Mr Agarwal (or anybody else),

Could you send me a copy of your article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" published in Powder Handling and Processing magazine?

Thanks in advance.

My email is: federico.guido.lavalle@lomanegra.com.ar

Federico Guido ■

Dear Mr Agarwal (or anybody else),

Could you send me a copy of your article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" published in Powder Handling and Processing magazine?

Thanks in advance.

My email is: federico.guido.lavalle@lomanegra.com.ar

Federico Guido ■

A.T. Agarwal, theory and design of pneumatic conveying article

Hello,

I am writing to let you know that I've read Mr. Agarwal article, and it is absolutely fantastic, first practical reading that I've done in this subject, others are much more theoretical.

I think it's best to complement it with Mr. Agarwal Excel spreadsheet though. ■

A.T. Agarwal, theory and design of pneumatic conveying article

Hello,

I am writing to let you know that I've read Mr. Agarwal article, and it is absolutely fantastic, first practical reading that I've done in this subject, others are much more theoretical.

I think it's best to complement it with Mr. Agarwal Excel spreadsheet though. ■

Sear Mr Agarwal,

I've received you article and was very usefull for me. I did an excel workshhet and simulate one of the conveying systems we have at the cement plant. Comparing the results of the simulation with the real data at the plant (yalking about pressure ldrop), both are similar.

Some questions:

a) Which are the units for the roughness factor mentiones in the article?

b) For a cement raw meal, which is the minimum required velocity in the pipe, working with a Fuller Kynion or Claudius Peters pump.

c) I've heard that for this type of pneumatic conveying systems, a straight pipe after the pump and before the first curve is needed. Is this correct? In our system we have the first curve, just 1,5 meters downstream the pump. Can we expect any problem?

Regrds

FEderico ■

Sear Mr Agarwal,

I've received you article and was very usefull for me. I did an excel workshhet and simulate one of the conveying systems we have at the cement plant. Comparing the results of the simulation with the real data at the plant (yalking about pressure ldrop), both are similar.

Some questions:

a) Which are the units for the roughness factor mentiones in the article?

b) For a cement raw meal, which is the minimum required velocity in the pipe, working with a Fuller Kynion or Claudius Peters pump.

c) I've heard that for this type of pneumatic conveying systems, a straight pipe after the pump and before the first curve is needed. Is this correct? In our system we have the first curve, just 1,5 meters downstream the pump. Can we expect any problem?

Regrds

FEderico ■

Dear Federico,

For raw meal, a minimum velocity of approx. 12.0 m/sec is required at atmospheric conditions.

Right after the pump, where the pressure is above the atmospheric pressure, the required velocity is lower according:

gas velocity = 12 / SQRT(pressure+1)

A straight section of 1.5 m should cause no real problems as there should be enough velocity developed to get the raw meal through the bend.

And if not, the raw meal will be forced by an increased air velocity (bend is partly blocked by slow moving raw meal) through the bend.

If you need a calculation of your system, provide the necessary installation data.

Have a nice day

Teus ■

Dear Federico,

For raw meal, a minimum velocity of approx. 12.0 m/sec is required at atmospheric conditions.

Right after the pump, where the pressure is above the atmospheric pressure, the required velocity is lower according:

gas velocity = 12 / SQRT(pressure+1)

A straight section of 1.5 m should cause no real problems as there should be enough velocity developed to get the raw meal through the bend.

And if not, the raw meal will be forced by an increased air velocity (bend is partly blocked by slow moving raw meal) through the bend.

If you need a calculation of your system, provide the necessary installation data.

Have a nice day

Teus ■

Dear Amrit Agarwal,

Thank you very much for your article.

It is useful, effective and valuable.

Best regards, ■

Dear Amrit Agarwal,

Thank you very much for your article.

It is useful, effective and valuable.

Best regards, ■

I have received Mr. Agarwal's article "Theory and Design of Dilute Phase Conveying Systems" and it is everything one could hope for to gain an understanding of the design principals for conveying systems.

Regards ■

I have received Mr. Agarwal's article "Theory and Design of Dilute Phase Conveying Systems" and it is everything one could hope for to gain an understanding of the design principals for conveying systems.

Regards ■

Dear Teus,

Thank you very much for your answer.

When you says: “the required velocity is lower according: gas velocity = 12 / SQRT(pressure+1)”, I suppose m/sec are the units for the velocity, but for de pressure? Bar?

I simulated the system, using the paper Amrit sent me, and the pressure drop through the system, using the simulation fits quite well, with the data measured at the plant. These results are shown in the file attached.

The problem is that in the practice, we never could reach 215 tph, that is the required capacity. When we go above 180 tph, the system begins to have problems.

Somebody recommends us to increase the straight line right after the pump, from 1,5 to 5 m. That’s why I made that question.

Other data of the system are also shown in the file attached.

Any help is welcome.

Regards

FEderico ■

Dear Teus,

Thank you very much for your answer.

When you says: “the required velocity is lower according: gas velocity = 12 / SQRT(pressure+1)”, I suppose m/sec are the units for the velocity, but for de pressure? Bar?

I simulated the system, using the paper Amrit sent me, and the pressure drop through the system, using the simulation fits quite well, with the data measured at the plant. These results are shown in the file attached.

The problem is that in the practice, we never could reach 215 tph, that is the required capacity. When we go above 180 tph, the system begins to have problems.

Somebody recommends us to increase the straight line right after the pump, from 1,5 to 5 m. That’s why I made that question.

Other data of the system are also shown in the file attached.

Any help is welcome.

Regards

FEderico ■

Dear Federico,

Based on the given data, I calculated your raw meal pneumatic conveying system and found that the calculated raw meal capacity is 225 tons/hr. at 2.0 bar line pressure.

The air velocity ranges from 8.5 m/sec at the beginning of the pipeline to 26 m/sec at the end of the pipeline.

This should be a normal operation.

Are these results the field measurements?

After the 1 m pipe section behind the screw pump, the air velocity is 8.49 m/sec and the raw meal velocity is 7.35 m/sec (86.5% or 13.5% slippage)

Enough raw meal velocity to get the material through the bend. A longer straight pipe section would the raw meal velocity just slightly.

The capacity of 180 tons/hr would be reached at a pipeline pressure of 1.32 bar.

The design, although not really oversized, seems to be OK.

However, although you have not described the nature of your problems, it is likely that one or more of your installation components is not working properly or not as built as designed.

The raw meal feeder is a screw pump.

A screw pump can stall at too high conveying pressures, due to the generated internal friction.

Or if the screw pump suffers from extensive backflow at a certain pressure, the screw capacity is limited at higher pressures and the pressure starts fluctuating or oscillating.

If this is the case, the problem should be at approx. 1.3 bar (180 tons/hr), but the system is still conveying.

Also it is possible that the compressor pressure already reaches the maximum of 2.0 bar when the pipe line pressure is at 1.3 bar and the relief valve of the compressor starts blowing off.

In that case, the pipeline is supplied with less air.

The system is operating in dense phase and therefore the pressure would increase, and the problem worsens until the pipe line is choked.

For further ideas, we would like to have a more elaborate description of the events and, if possible,

the screw pump data.

Have a nice day

Teus

Attachments

rawmealcalculationsv1 (PDF)

■

Dear Federico,

Based on the given data, I calculated your raw meal pneumatic conveying system and found that the calculated raw meal capacity is 225 tons/hr. at 2.0 bar line pressure.

The air velocity ranges from 8.5 m/sec at the beginning of the pipeline to 26 m/sec at the end of the pipeline.

This should be a normal operation.

Are these results the field measurements?

After the 1 m pipe section behind the screw pump, the air velocity is 8.49 m/sec and the raw meal velocity is 7.35 m/sec (86.5% or 13.5% slippage)

Enough raw meal velocity to get the material through the bend. A longer straight pipe section would the raw meal velocity just slightly.

The capacity of 180 tons/hr would be reached at a pipeline pressure of 1.32 bar.

The design, although not really oversized, seems to be OK.

However, although you have not described the nature of your problems, it is likely that one or more of your installation components is not working properly or not as built as designed.

The raw meal feeder is a screw pump.

A screw pump can stall at too high conveying pressures, due to the generated internal friction.

Or if the screw pump suffers from extensive backflow at a certain pressure, the screw capacity is limited at higher pressures and the pressure starts fluctuating or oscillating.

If this is the case, the problem should be at approx. 1.3 bar (180 tons/hr), but the system is still conveying.

Also it is possible that the compressor pressure already reaches the maximum of 2.0 bar when the pipe line pressure is at 1.3 bar and the relief valve of the compressor starts blowing off.

In that case, the pipeline is supplied with less air.

The system is operating in dense phase and therefore the pressure would increase, and the problem worsens until the pipe line is choked.

For further ideas, we would like to have a more elaborate description of the events and, if possible,

the screw pump data.

Have a nice day

Teus

Attachments

rawmealcalculationsv1 (PDF)

■

Dear Teus,

Thank you so much for your answer.

The results shown in my previous post, were results predicted from my simulation using an excel worksheet, but those were in line with measured values.

You can find the field measurements in Annex 1, where you can realize how the system configuration at the present is (two compressors, one pump). According to original calculations the system was design to work with one compressor and one pump, but of course the situation was worse than the one we have today. The volumetric flow rate (8166 standard m3/h), was also measured.

I’m trying to describe the system problems:

Today the system has not been able to achieve more than 160 to 170 mtph on a consistent and reliable basis. When attempts have been made to run at higher capacities, the system has not been able to operate reliable on a continuous basis. So we are reluctant to operate the system beyond 160 mtph set point.

Rates in 180-185 mtph were made on a very short term basis because the system was starting to show signs of collapsing and within moments of a 190 mtps set point, the feed system vent line to the screw pump went positive, the Coreolis flow meter operation became unstable and the system has to be immediately brought down to a lower setting to avoid a potentially catastrophic situation of shutting down the kiln.

Besides, the following comments can be made:

1)The pump operates reliably up to a line pressure of approximately 0,95 to 1,0 barg. At his level, several events begin to take place:

a)Flapper valve arm movement increases noticeably

b)Pump motor amp variation increases

c)Material level backs up in the pump feed hopper

d)Vent system goes to a positive value

Regarding the pump data is a Claudius Peters X-300, but what other data do you need to analyze the problem?

Another question, in your opinion, if you have to design the system starting from 0, considering the pipe line configuration we have at the present, and taking into account we want to be in the safe side, as this installation cost almost nothing, and we are losing a lot of money due this restriction: what would you recommend to change in a gross basis, bigger pipe diameter, bigger flow and/or pressure at the compressors, bigger pump?

On the othe hand, according to your calculations and just to know: why the solid velocities are too much lower than gas velocities at the bends?

Regards,

Federico

href="https://forum.bulk-online.com/attachment.php?attachmentid=26097&d=1299591412" title="Name: Annex 1.pdfViews: 251Size: 33.8 KB">Annex 1.pdf ■

Dear Teus,

Thank you so much for your answer.

The results shown in my previous post, were results predicted from my simulation using an excel worksheet, but those were in line with measured values.

You can find the field measurements in Annex 1, where you can realize how the system configuration at the present is (two compressors, one pump). According to original calculations the system was design to work with one compressor and one pump, but of course the situation was worse than the one we have today. The volumetric flow rate (8166 standard m3/h), was also measured.

I’m trying to describe the system problems:

Today the system has not been able to achieve more than 160 to 170 mtph on a consistent and reliable basis. When attempts have been made to run at higher capacities, the system has not been able to operate reliable on a continuous basis. So we are reluctant to operate the system beyond 160 mtph set point.

Rates in 180-185 mtph were made on a very short term basis because the system was starting to show signs of collapsing and within moments of a 190 mtps set point, the feed system vent line to the screw pump went positive, the Coreolis flow meter operation became unstable and the system has to be immediately brought down to a lower setting to avoid a potentially catastrophic situation of shutting down the kiln.

Besides, the following comments can be made:

1)The pump operates reliably up to a line pressure of approximately 0,95 to 1,0 barg. At his level, several events begin to take place:

a)Flapper valve arm movement increases noticeably

b)Pump motor amp variation increases

c)Material level backs up in the pump feed hopper

d)Vent system goes to a positive value

Regarding the pump data is a Claudius Peters X-300, but what other data do you need to analyze the problem?

Another question, in your opinion, if you have to design the system starting from 0, considering the pipe line configuration we have at the present, and taking into account we want to be in the safe side, as this installation cost almost nothing, and we are losing a lot of money due this restriction: what would you recommend to change in a gross basis, bigger pipe diameter, bigger flow and/or pressure at the compressors, bigger pump?

On the othe hand, according to your calculations and just to know: why the solid velocities are too much lower than gas velocities at the bends?

Regards,

Federico

href="https://forum.bulk-online.com/attachment.php?attachmentid=26097&d=1299591412" title="Name: Annex 1.pdfViews: 251Size: 33.8 KB">Annex 1.pdf ■

Dear Federico,

The phenomena, which you are describing, are all related to the screw pump.

The problems are starting to occur at a line pressure level of approx. 1 bar and above.

The signs are strongly indicating that the screw pump can handle line pressures up to approx. 1 bar and above this pressure, air starts blowing back into the screw.

At the moment that the air blows back into the screw, the flapper valve closes due to the reverse flow and air is blown into the pump feed hopper, causing a level rise and a positive pressure in the vent system.

The sharp increased pump motor current indicates that the screw pump is overfed and the formed raw meal plug is getting stuck.

A solution might be to design a lower pressure system with the same airflow and gaining pressure drop over the pump mixing box.

I will investigate that.

Further:

-Is this problem occurring from day one of operation?

-Is the screw pump worn too much?

-As the raw meal conveying line is crucial to your operation, do you have a (new) spare screw pump available, which can replace the present one?

-What is the reaction of the screw pump supplier?

-Are the exact suppliers performance data of the supplied screw pump known? (Material, volume, maximum pressure, etc)

-You state that the original calculations were for one compressor (4084 m3/hr). What was the reaction of the supplier that you needed the spare compressor to get some reliable conveying?

-Can you give the data from the name plates on the compressors? (volumetric flow, pressures, rpm, make, type, gear ration, etc)

The solid velocities after a bend are much lower than the air velocity, because the solid velocity decreases as a result of friction in the bend, and the air velocity increases, due to the reduced free area in the pipe (lower solid velocity requires bigger flowing area for the same rate)

Have a nice day

Teus ■

Dear Federico,

The phenomena, which you are describing, are all related to the screw pump.

The problems are starting to occur at a line pressure level of approx. 1 bar and above.

The signs are strongly indicating that the screw pump can handle line pressures up to approx. 1 bar and above this pressure, air starts blowing back into the screw.

At the moment that the air blows back into the screw, the flapper valve closes due to the reverse flow and air is blown into the pump feed hopper, causing a level rise and a positive pressure in the vent system.

The sharp increased pump motor current indicates that the screw pump is overfed and the formed raw meal plug is getting stuck.

A solution might be to design a lower pressure system with the same airflow and gaining pressure drop over the pump mixing box.

I will investigate that.

Further:

-Is this problem occurring from day one of operation?

-Is the screw pump worn too much?

-As the raw meal conveying line is crucial to your operation, do you have a (new) spare screw pump available, which can replace the present one?

-What is the reaction of the screw pump supplier?

-Are the exact suppliers performance data of the supplied screw pump known? (Material, volume, maximum pressure, etc)

-You state that the original calculations were for one compressor (4084 m3/hr). What was the reaction of the supplier that you needed the spare compressor to get some reliable conveying?

-Can you give the data from the name plates on the compressors? (volumetric flow, pressures, rpm, make, type, gear ration, etc)

The solid velocities after a bend are much lower than the air velocity, because the solid velocity decreases as a result of friction in the bend, and the air velocity increases, due to the reduced free area in the pipe (lower solid velocity requires bigger flowing area for the same rate)

Have a nice day

Teus ■

Dear Federico,

Looking at the pressure drops between the compressors and the pressure drop over the screw pump header box, I noticed that this combined pressure drop is approx. 0.67 bar.

As the system is designed for 1 compressor operating, I assume that now the system is operating with 2 compressors, the designed air feeding pressure drop should be 0.67/2^2 = 0.17 bar.

Can you supply an isometric of the piping between the compressors (length, number of bends, diameter) and the screw pump to find out how to reduce this pressure drop?

For the time being, a reduced air feeding pressure drop will not influence the conveying line pressure drop and will not solve the screw pump problems.

It saves energy and makes more pressure available for pneumatic conveying.

All for now.

Teus ■

Dear Federico,

Looking at the pressure drops between the compressors and the pressure drop over the screw pump header box, I noticed that this combined pressure drop is approx. 0.67 bar.

As the system is designed for 1 compressor operating, I assume that now the system is operating with 2 compressors, the designed air feeding pressure drop should be 0.67/2^2 = 0.17 bar.

Can you supply an isometric of the piping between the compressors (length, number of bends, diameter) and the screw pump to find out how to reduce this pressure drop?

For the time being, a reduced air feeding pressure drop will not influence the conveying line pressure drop and will not solve the screw pump problems.

It saves energy and makes more pressure available for pneumatic conveying.

All for now.

Teus ■