The application of pneumatic conveying to the removal of fly ash from coal fired power stations

Pneumatic conveying is used widely around the world to convey a vast number of different products and it is generally considered to be a reliable means of conveying dry bulk particulate materials. There are two basic requirements to ensure that the system will operate reliably. One is to feed the material into the pipeline at a steady controlled rate, without exceeding a given maximum value. The other is to ensure that the pressure and volumetric flow rate of the air provided are sufficient to convey the material reliably through the length of the pipeline. There is then one problem with regard to the continued reliable operation of the system and that relates to any possible changes in the properties of the material that is being conveyed. Although the presentation refers to fly ash, the points raised here are likely to be appropriate for many other materials, particularly where particle size distribution may vary with respect to time for some reason, or vary as a result of a change of source of the material to be conveyed.