# Thread: Is pneumatic conveying an understood science now?

1. ## Is pneumatic conveying an understood science now?

The basic pneumatic conveying principle is simple: A particle is propelled by a moving gas through a conduit, normally a pipe.

As simple as the definition of pneumatic conveying is, so difficult is the physical description and the calculation of this technology.

Many articles, reports, thesis’s, which describe sometimes a specific part of pneumatic conveying and a number of books are published, describing an overview of the derived formulas, manual calculation examples and built installations

All the published information is valuable in itself, but never resulted in an overall, complete description of all the physical events and the interactions that take place in pneumatic conveying.

This is also expressed by the high number of regression formula that pop-up in the pneumatic conveying papers.
Sometimes, a regression formula suggests an underlying physical law, but is not always recognized as such.

Comparing publication results is also very difficult, because of the mixed use of SI-units (which is a coherent system of units) and Imperial units.

Dr.-ING Manfred Weber, Karlsruhe, Germany, wrote a book about pneumatic conveying in 1973, in which he described pneumatic conveying in a scientific way, based on equilibrium of forces, Newton laws, energy laws, continuity laws, Bernoulli law, physical properties of gas (gas laws) and material properties (density, size).
The purpose of the book was to set a common theory for pneumatic conveying, based on only a mathematical description of physics.
This work can be considered as the start of a structured research of pneumatic conveying and as a guideline and a basis, which could be adapted for individual cases.

Today, approx. 45 years later, there are a lot of papers, publications, reports etc. and many installations built, but still the overall, integral description of pneumatic conveying, accepted by the industry and universities, is not yet commonly available.

CFD computer programs generate amazing results in visualizing pneumatic conveying, but are not easy to use for designing an installation, including feeders, compressors, filters, etc..
Let alone to use a CFD program to figure out the optimum combination of compressor type, pipe diameter and pressure drop.

A universal and integral description of a pneumatic conveying installation calculation program must have the following properties, capabilities and possibilities.

- Based on universal, physical laws
- The same formulas for vacuum conveying and pressure conveying
- Calculate gas pressure drops
- Calculate gas velocities
- Calculate various feeder systems
- Calculate various conveying gas supplies (sonic choke, pressure reducer, compressor type) characteristics
- Calculate material/gas separators (filters, cyclones)
- Calculate material velocities
- Calculate heat exchanges
- Calculate temperature changes
- Calculate sedimentation
- Calculate condensation
- Calculate energies
- Calculate bend friction and bend material velocity losses
- Calculate the existing partial gas pressure drops.
- Calculate the material related gas pressure drop
- Calculate gas supply line and vent line pressure drops
- Can calculate a Zenz diagram
- Inputs for ambient conditions and back pressure at end of conveying pipe line.
- Installation Quick modeling for vacuum- and pressure installations (including ship unloaders) for first assessment.
- Applicable for ALL types of pneumatic conveying systems.
- Transfer laboratory test to real installations without scaling
- Internal database for compressors and materials and calculated installations.
- System performance calculations (accounting for pressurizing tanks and purging pipeline)
- System evaluation
- Pneumatic conveying research
- Designing
- Silo pressure equalization during purging.
- Required aeration volumes and pressures

Back in 1980, when I had to renovate 4 pneumatic grain unloaders with an increased unloading capacity of 400 tons per suction pipe and the book of Dr.-ING Manfred Weber was 5 years old,
I started my own theory building, encouraged by the scientific/practical approach of Dr.-ING Manfred Weber.

Over the last 37 years, the developed algorithm was fine-tuned by testing many real scale installations in grains, seeds, derivatives, cement, fly ash, alumina, coal, bentonite, barite and many other materials.
The derived formulas and mathematical, involved work is written down in an eight hundred plus document.

This effort resulted in the foundation of www.yarca.nl , offering pneumatic calculation services.

The question in the title of this thread is now answered with a definite YES

2. ## Software or calculations?

Hi Teus;
It has been a long time for me to check in with you. Does your new company sell calculations or software?
Tot ziens,
Ralf

Originally Posted by Teus Tuinenburg
The basic pneumatic conveying principle is simple: A particle is propelled by a moving gas through a conduit, normally a pipe.

As simple as the definition of pneumatic conveying is, so difficult is the physical description and the calculation of this technology.

Many articles, reports, thesis’s, which describe sometimes a specific part of pneumatic conveying and a number of books are published, describing an overview of the derived formulas, manual calculation examples and built installations

All the published information is valuable in itself, but never resulted in an overall, complete description of all the physical events and the interactions that take place in pneumatic conveying.

This is also expressed by the high number of regression formula that pop-up in the pneumatic conveying papers.
Sometimes, a regression formula suggests an underlying physical law, but is not always recognized as such.

Comparing publication results is also very difficult, because of the mixed use of SI-units (which is a coherent system of units) and Imperial units.

Dr.-ING Manfred Weber, Karlsruhe, Germany, wrote a book about pneumatic conveying in 1973, in which he described pneumatic conveying in a scientific way, based on equilibrium of forces, Newton laws, energy laws, continuity laws, Bernoulli law, physical properties of gas (gas laws) and material properties (density, size).
The purpose of the book was to set a common theory for pneumatic conveying, based on only a mathematical description of physics.
This work can be considered as the start of a structured research of pneumatic conveying and as a guideline and a basis, which could be adapted for individual cases.

Today, approx. 45 years later, there are a lot of papers, publications, reports etc. and many installations built, but still the overall, integral description of pneumatic conveying, accepted by the industry and universities, is not yet commonly available.

CFD computer programs generate amazing results in visualizing pneumatic conveying, but are not easy to use for designing an installation, including feeders, compressors, filters, etc..
Let alone to use a CFD program to figure out the optimum combination of compressor type, pipe diameter and pressure drop.

A universal and integral description of a pneumatic conveying installation calculation program must have the following properties, capabilities and possibilities.

- Based on universal, physical laws
- The same formulas for vacuum conveying and pressure conveying
- Calculate gas pressure drops
- Calculate gas velocities
- Calculate various feeder systems
- Calculate various conveying gas supplies (sonic choke, pressure reducer, compressor type) characteristics
- Calculate material/gas separators (filters, cyclones)
- Calculate material velocities
- Calculate heat exchanges
- Calculate temperature changes
- Calculate sedimentation
- Calculate condensation
- Calculate energies
- Calculate bend friction and bend material velocity losses
- Calculate the existing partial gas pressure drops.
- Calculate the material related gas pressure drop
- Calculate gas supply line and vent line pressure drops
- Can calculate a Zenz diagram
- Inputs for ambient conditions and back pressure at end of conveying pipe line.
- Installation Quick modeling for vacuum- and pressure installations (including ship unloaders) for first assessment.
- Applicable for ALL types of pneumatic conveying systems.
- Transfer laboratory test to real installations without scaling
- Internal database for compressors and materials and calculated installations.
- System performance calculations (accounting for pressurizing tanks and purging pipeline)
- System evaluation
- Pneumatic conveying research
- Designing
- Silo pressure equalization during purging.
- Required aeration volumes and pressures

Back in 1980, when I had to renovate 4 pneumatic grain unloaders with an increased unloading capacity of 400 tons per suction pipe and the book of Dr.-ING Manfred Weber was 5 years old,
I started my own theory building, encouraged by the scientific/practical approach of Dr.-ING Manfred Weber.

Over the last 37 years, the developed algorithm was fine-tuned by testing many real scale installations in grains, seeds, derivatives, cement, fly ash, alumina, coal, bentonite, barite and many other materials.
The derived formulas and mathematical, involved work is written down in an eight hundred plus document.

This effort resulted in the foundation of www.yarca.nl , offering pneumatic calculation services.

The question in the title of this thread is now answered with a definite YES

3. Hi Ralf,

Indeed, a long time ago.
Yarca pcs is offering/selling calculations. (Not the software)
Based on a customer’s request, a pneumatic conveying calculation
is executed.
Sometimes for designing and sometimes for system/problem evaluation.

Auf Wiederhören

4. ## Thanks!

Originally Posted by Teus Tuinenburg
Hi Ralf,

Indeed, a long time ago.
Yarca pcs is offering/selling calculations. (Not the software)
Based on a customer’s request, a pneumatic conveying calculation
is executed.
Sometimes for designing and sometimes for system/problem evaluation.

Auf Wiederhören
Hi Teus;
Thanks for the note. That is awesome. I will see if I can forward you folks who are usually struggling with such conveying work and trouble shooting.
Ralf