Some problems in the area of conveyance of particulate materials were identified in International Application No. PCT/US2009/006733, published on Jul. 8, 2010 as International Publication No. WO/2010/077348. That publication is herein incorporated by reference, and the disclosure of that publication is deemed to be combined with the disclosure of the present specification.
Particulate materials such as coal are often transported in open top conveyances, usually railway gondola cars. The material is dumped somewhat indiscriminately into these cars to fill them by hoppers or other large-volume low-accuracy supply mechanisms, with the result that the material is piled somewhat loosely in the gondola car in a humped pile, high in some places, and not present in other void areas in the car.
The humped pile has a number of drawbacks. For one, it positions the particulate material such that air passing over the pile more readily carries away lighter particles and dust, resulting in waste and local deposition of large amounts of undesirable dust etc. Also, some space in the car is wasted by the lack of complete distribution of the material in the interior of the car.
Another problem relates to methods adopted to prevent dust from blowing away from the material in the gondola car. WO/2010/077348 shows a system and a method for compacting materials in an open top conveyance. This compaction is beneficial to prevent fly away of dust or small particulate material. Where the material is loaded in a high humped pile in the railway car, though, it may produce a problem, in that humped pile of material in the gondola car may be so disproportionately located in the car that compaction is difficult, and the amount of material that has to be moved to be compacted may strain the apparatus.