Pneumatic Conveyors

Over the years we have been involved with a large number of coal handling systems, and quite a number of these have involved pneumatic conveying of the product.

Traditionally the coal is fed from a bunker by either a 5" or 6" screw or auger conveyor. At the discharge from the auger, the coal is delivered into an air stream. We have developed a very effective air seal arrangement to protect the drive end bearing on the coal auger from the ingress of dust from the air stream. We also fit a stone collection box under the infeed, which is fitted with a quick release access door.

The pneumatic convey line is usually heated and lagged, to prevent problems with moisture in the line causing product build-up and eventual blocking of the line. The most common way to heat the line is to run a small steam and condensate pipe under the lagging, to a radiator type heater located between the fan and the auger discharge.

With some installations, the coal is pneumatically fed directly into the boiler, but this creates an imbalance of over fired air, and reduces the efficiency of the boiler. The excess air also creates increased air velocity inside the boiler, which results in increased wear. We prefer to discharge the coal into an overhead storage hopper, mounted alongside the boiler, and feed the coal into the boiler via a coal auger. In these installations, the coal is separated from the air system via a cyclone and bag filter.

Click to go to the pneumatic photo gallery.  

 Typical belt conveyor.