Process and equipment for the production of ultrafine powders particularly of coal powders with the help of a continuous cold warm influence on the ground material
Patent 3991943 Issued on November 16, 1976. Estimated Expiration Date: 
November 16, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 16, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1311645 1679857 3797757 Inventor
AssigneeApplicationNo. 560400 filed on 03/20/1975US Classes:241/1, By operations other than force of contact with solid surface241/23With heating or cooling of materialExaminersPrimary: Custer, Granville Y. Jr.Attorney, Agent or FirmForeign Application Priority Data1974-03-21 DTAbstractA 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. | |
