### Re: Dilute-Phase Pneumatic Conveying - Particle Velocity At The…

Dear koffes,

I have a dilute phase pneumatic conveying system, transporting bulk solids over a 200 to 800 m pipeline using compressed air.

From data, I know the initial airspeed, pressure and temperature before the solids are added via a silo.

-200 to 800 m pipeline is quite a broad range. That cannot be the same conveying rate.

-Knowing the initial airspeed, pressure and temperature, you must also have the pipe diameter. (Otherwise you wouldn’t be able to calculate the air speed)

-Knowing the airspeed, you must also know the “pick-up” velocity of the 9 mm spheres.

-knowing the “pick-up” velocity of the 9 mm spheres, you must also know the suspension velocity of the particles and therefore also the particle density.

-You state that you

have a dilute phase pneumatic conveying system, transporting bulk solids over a 200 to 800 m pipeline using compressed air.

**Is it working?**

Complications: Due to the length of the line, I presume a compressible fluid model must be used, and the pipeline has some sections of vertical transport.

In a pneumatic conveying calculation, a compressible fluid model must be used.

Simplifications: The solids can be seen as perfect 9 mm diameter spheres, and probably the system can be viewed as isentropic.

The system is closer to isothermal, as the heat content of the material is more than the heat content of the conveying gas, and because of heat exchanged with the surroundings and losses that are converted to heat in the end (s.a. friction).

Desired result: I would like to know the particle velocity at the end of the pipeline where the particles are released into the atmosphere.

A velocity calculation of the particles at any place in the pipe line must be in the calculation algorithm, as this velocity influences the material related energy losses and therefore the related pressure drop.

The pressure drop in return determines the gas velocity, influencing the particle velocity, a.s.o.

1. Do you know of any available software that can perform these calculations?

2. Could you recommend some good books in order to assist me in modeling such a system? (I have already read much of "Pneumatic conveying of solids", "Fluidization of Bulk Solids" and "Multiphase Flows with Droplets and Particles, Second Edition", but all of these seem quite indirect with respect to my problem.

-If there is available software which can do this, I doubt that it is for sale.

-Books, articles, studies, reports, etc. explain a lot, but never are practical for designing.

have a nice day ■

Teus

### Re: Dilute-Phase Pneumatic Conveying - Particle Velocity At The…

Thank you for the detailed reply

Yes, due to expansion I expect to see an increase in airspeed across the length of the pipeline. Due to friction and bends at the end however, I presume that the particle velocity will be quite low compared to the initial airspeed. Parameters such as particle density, pick-up speed, and pipeline diameter are known. I must make some assumptions with respect to the suspension velocity.

The conveying system works as intended, and has been tested up to 1000 m.

You are quite right, the system is closer to isothermal. ■

## Dilute-phase Pneumatic Conveying - Particle Velocity at the End of the Transport Line

Hello.

I have a dilute phase pneumatic conveying system, transporting bulk solids over a 200 to 800 m pipeline using compressed air.

From data, I know the initial airspeed, pressure and temperature before the solids are added via a silo.

Complications:Due to the length of the line, I presume a compressible fluid model must be used, and the pipeline has some sections of vertical transport.Simplifications:The soilds can be seen as perfect 9 mm diameter spheres, and probably the system can be viewed as isentropic.Desired result:I would like to know the particle velocity at the end of the pipeline where the particles are released into the atmosphere.1. Do you know of any available software that can perform these calculations?

2. Could you recommend some good books in order to assist me in modeling such a system? (I have already read much of "Pneumatic conveying of solids", "Fluidization of Bulk Solids" and "Multiphase Flows with Droplets and Particles, Second Edition", but all of these seem quite indirect with respect to my problem.

Thank you.

Illustration added by Administrator as an example only:■Dilute-phase conveying system