Pneumatic conveying is as simple or as complicated as you want it to be. Wear through bends; moisture and filter bag corrosion are issues that are frequently raised in these forums. Provided these issues have been addressed a pneumatic conveying system can provide housekeeping benefits. It's main advantages are compactness, encasement, directional flexibility and minimal support requirements.

There is a relatively sparse conveying capacity and the energy consumption is very high.

There have been some disappointments, notably the Muschelknautz bypass and less ambitious attempts, at dense phase conveying but although even the lean phase theory always falls back on empirical tests there is often enough data to predict a useable system. This is true throughout conveying: belts; pipes; hydraulics; scraper chain you name it, the reason is not down to engineering but due mostly to material misbehaviour. We are called upon to design systems to handle material which either change characteristics whimsically or else haven't even been produced yet. This makes testing either unreliable or impossible. That said, it is far easier to build a full scale test circuit in pneumatics than it is to build a small scale belt rig.

Ease of building a test circuit would get my vote.

A Muschelknautze system was built in a Shell refinery to recirculated the spent catalyst from the reactor and back through the regenerator, it cost a fortune, didn't work and so got blacklisted. Its the first thing mentioned in the pneumatic conveying specifications as a not to do; don't even think about it. Think about it: if Shell can't get it to work then who can?

Simplicity is not a good enough reason. ■

Originally Posted by acmeairequipments

To Johngateley,



Oh wow, Thank you for giving reply but want more reviews. Waiting for more reviews about Pneumatic Conveying.

Dear Sir,

I am one of those engineers who have lived with both mechanical conveyors (such as screw conveyors, belt conveyors and bucket elevators), and pneumatic conveyors. For short and straight routes, mechanical conveyers are still viable but for long, complicated routes (mixture of horizontal and vertical sections with bends) pneumatic conveyors are much better.

Regards,

Amrit Agarwal

Pneumatic Conveying Consulting

Email: polypcc@aol.com ■

Originally Posted by Amrit Agarwal

......for long, complicated routes (mixture of horizontal and vertical sections with bends) pneumatic conveyors are much better. ....

Quite, provided that the propellant and material have acceptable conveying qualities in terms of particle size, density, moisture content and relatively short distance delivery requirements. It is advisable to site the beds in accessible spots to facilitate replacement.

Pneumatic conveyors are simply the cheapest and cleanest way if the material, throughputs and route are all acceptable. But you shouldn't tell a customer that! He is saving money on a smaller building cost and is prepared to pay through the nose for a few pipes. Air cleaning and air moving would be required anyway with any exposed system so the equivalent cost of the system really boils down to a few pipes and elbows.....and it is easy to do the FAT before starting erection. ■