ApplicationNo. 560400 filed on 03/20/1975
US Classes:241/1, By operations other than force of contact with solid surface241/23With heating or cooling of material
ExaminersPrimary: Custer, Granville Y. Jr.
Attorney, Agent or Firm
Foreign Application Priority Data1974-03-21 DT
AbstractA process is disclosed for conversion of coal powder of 4 micron size into a finer powder of the order of 1/400 micron by passing through a vertical tube of sufficient length at a temperature of -77° C and thereafter passing through a second chamber by force of gravity where a counter stream of heated nitrogen at 780° C causes the powder to break up into the smaller size particles.