Pulverization of solid feed material in a grinding chamber using a gas stream is known in the art. For example, a jet mill is a type of grinding device that relies on high-speed gas streams to grind material inside the grinding chamber. Pulverization may take place in a central toroidal grinding chamber of the jet mill as the process material is driven around the perimeter of the chamber by multiple jets of air or steam. Size reduction via attrition may be a result of high-velocity collisions and resulting compressive forces between particles of the process material itself, and/or between particles of the processes material and interior walls of the grinding chamber of the conventional jet mill. The pulverization in a conventional jet mill may cause wear to the grinding chamber as the gas streams, carrying pulverized particles, impacts the grinding chamber.
It is known that wear in the conventional jet mill is responsible for limiting the size of the conventional jet mill. As the size (e.g., length, width, and/or radius) of the conventional jet mill increases, the volume of the process material that could pass through the jet mill may increase roughly by a magnitude corresponding to a cube of the size increase, and the surface of the grinding chamber may increase roughly by a magnitude corresponding to a square of the size increase. For example, if the size of the conventional jet mill is doubled, the volume of the process material that could pass through the jet mill may increase as much as by eight times and the wearable surface may only increase as much as by four times. The amount of wear in the conventional jet mill may be proportional to the amount of the process material and thus takes on the level of exponential increase of the process material. Accordingly, the exponential increase of potential wear may be much faster than the increase of wearable surface of the grinding chamber when the size of the conventional jet mill increases. This geometric wear limitation may limit scaling-up of the conventional jet mill. A conventional jet mill typically has an upper size limit of approximately one meter or about forty-two inches.