Dear Damianch,

I am afraid that a dilute pneumatic conveying system will not solve your problem of damage coffee beans.

I guess that the suspension velocity of a coffee bean is approx. 12 to 14 m/sec, which results in a pickup velocity of approx. 30 m/sec., resulting in a coffee bean velocity of approx. 15 m/sec.

This high coffee bean velocity will damage the beans by collisions.

A pneumatic system for 0.1 tons/hr is a very small system and the pipe diameter will be therefor also very small. (Maybe even small compared to the size of the coffee beans)

In addition, you will have to clean the convey air from the dust, which requires a self-cleaning filter and an air separator with a rotary valve to force the conveying air through the filter.

Look for a Cablevey conveyor or a small conveyor belt

Have a nice day ■

Dear Damianch,

A vacuum system will cause at least the same amount of damage to the roasted coffee beans.

Have a nice day ■

As I scrolled down the first post I was wondering where the Cablevey advert had got to.

Imagine my satisfaction when I read Teus' reply. It really is your best choice. ■

Roasted coffee beens can be conveyed in dense phase easily at 2m/s pick up velocities.

But the degradation will still be there i wont recommend this. The best option is to use

vibratory conveyors if there is no elevation required otherwise an aero-mechanical

conveyor is a good solution. ■

Originally Posted by Damianch

Hello to all,

I am new to this field and i want some help.Here is my prolem:We want to convey roasted coffee beans from a storage silo to a packaging machine.So far, this was made by a screw conveyor, but this caused damage to the beans.So we decided to change the conveying system and convey the beans with a pneumatic system.Conveying wil be carried out in small batches.Totally, the conveying quantity will be max 100 kg per hour and the conveying distance less than 5 meters.I searched and studied many articles and guides but they focus on long distances and big quantities to be conveyed.With the research i made i think that appropriate solution for my problem is dillute phase and a centrifugal blower.I would appreciate so much any help you could offer to me,either by proposing something to study or by telling me your opinion.

Thank you very much in advnace.

========================================================================

Dear Damianch,

Pneumatic conveying is commonly used for longer distances because of its simplicity Vs mechanical conveyors. But its principles are applicable for both short or long distances, low or high conveying rates.

Your main issue is avoidance of any damage to the roasted coffee beans. This damage can be greatly reduced by using a low velocity, plug type, dense phase system. Velocity can be as low as few ft/sec. Systems like this are commercially available from many vendors.

Cableveyors are also an option but some damage to the beans may still exist due to wall friction.

Regards,

Amrit Agarwal

Pneumatic Conveying Consulting

Email: polypcc@aol.com ■

Originally Posted by Damianch

Dear Amrit Agarwal,

Thank you very much for your reply.I understand that the principles of pneumatic conveying are the same for short and long distances but I have hesistation on how applicable and functional is a pneumatic conveying system on such small distances and conveying rates as my situation.However,my main problem is the product degradation,as you understood too.As you say a Cableveyor may cause damage to the beans due to wall friction and i believe that it is possible if is working in high velocities.But I also believe that in a dense phase system wall friction will still exist causing damage to the beans.The question now in order to choose the appropriate conveying system is the percentage of degradation that causes each conveying system (dense phase or Cableveyor).But to answer this,you have to experiment with these systems in real working conditions,and this is probably unfeasible.

Have a nice day Amrit and thank you again.

====================================================================

Dear Damianch,

All initial research work in pneumatic conveying was conducted in small scale test labs using low rates and short distances such as 20 ft long horizontal lines to develop the fundamentals of pneumatic conveying technology. Even today, the quality control test labs of large production plants have very small conveying rates and short conveying distances.

I think, from technology view point, there should not be any hesitation in using pneumatic conveying for very low conveying rates and very short conveying distances.

But if product degradation is completely unacceptable, you may look into other methods such as capsule conveying.

Regards,

Amrit Agarwal

Pneumatic Conveying Consulting

email: polypcc@aol.com ■

Cheapest in order:

Screw - which is already off your map;

Pneumatic - 5m of pipe and a small fan plus a feed device;

Capsule - the difference between pneumatic and capsule is.....the capsule and the airflow reversing valve;

Cableveyor - actually the capsule fits the bill nicely...as Leon Harris will tell you. Power consumption should be less as well.

Thank you Amrit, for opening my eyes to a new plausible method. ■

Virtually any method of transferring the beans will have some form of breakage, even hand scooping could damage a tiny bit. The question is what level of breakage is acceptable, and at what cost for the equipment.

All the above methods will cause some damage. We have implemented a cost-effective transfer system using Pneu-Con vacuum loaders. They work well for short distances and low rates, and specify a tangential inlet to gently transition the beans into the receiver.

The vacuum loader is worth a look before you commit to a more expensive solution.

http://www.pneumaticconveyingsolutio...conveying.html ■

Damianch,

I had to just jump in here. Please contact Young Industries, http://www.younginds.com/

Based on the small capacity required and short distance, I would first look at a Young Industries Product Pump. This is a small Multi-Phase conveying unit that would allow you to move the beams at a very slow rate through the pipe and prevent breakage. It operates on a small amount of in-plant compressed air at low pressures, and the only moving parts (for a coffee bean application) would be a Knife gate and a Butterfly Valve.

We work with the coffee and tea industry a lot not only with pneumatic conveying but blending.

Hope this helps

Originally Posted by Damianch

Hello to all,

I am new to this field and i want some help.Here is my prolem:We want to convey roasted coffee beans from a storage silo to a packaging machine.So far, this was made by a screw conveyor, but this caused damage to the beans.So we decided to change the conveying system and convey the beans with a pneumatic system.Conveying wil be carried out in small batches.Totally, the conveying quantity will be max 100 kg per hour and the conveying distance less than 5 meters.I searched and studied many articles and guides but they focus on long distances and big quantities to be conveyed.With the research i made i think that appropriate solution for my problem is dillute phase and a centrifugal blower.I would appreciate so much any help you could offer to me,either by proposing something to study or by telling me your opinion.

Thank you very much in advnace.

■

Dear Damianch,

What about a vibration feeder?

Put a vibration-chute in place of the existing screwfeeder, which you are using now and you wouldn´t have any breakage of coffee-beans furthermore.

In my eyes (normally I am working as a consultant for pneumatic conveying) that would be the best solution for your requirements. Very low conveying velocities (approx. 2 - 5 cm/s) are possible.

Best regards

Klaus Schneider

KS-Engineering GmbH ■

Originally Posted by Damianch

Hello to all,

I am new to this field and i want some help.Here is my prolem:We want to convey roasted coffee beans from a storage silo to a packaging machine.So far, this was made by a screw conveyor, but this caused damage to the beans.So we decided to change the conveying system and convey the beans with a pneumatic system.Conveying wil be carried out in small batches.Totally, the conveying quantity will be max 100 kg per hour and the conveying distance less than 5 meters.I searched and studied many articles and guides but they focus on long distances and big quantities to be conveyed.With the research i made i think that appropriate solution for my problem is dillute phase and a centrifugal blower.I would appreciate so much any help you could offer to me,either by proposing something to study or by telling me your opinion.

Thank you very much in advnace.

Damian, check out the Olds Elevator at http://www.oldselevator.eu/

The olds elevator will not damage any product during elevation and can be sized for any capacity. It can elevate vertical or inclined and can be used as a dosing unit as well.

Best regards

Be Davids ■