The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 07, 2006
Filed:
Apr. 01, 2002
Tetsuharu Ibaraki, Kimitsu, JP;
Takashi Yamamoto, Kimitsu, JP;
Yoichi Abe, Futtsu, JP;
Shigeki Takahashi, Futtsu, JP;
Kazunori Nagai, Futtsu, JP;
Tetsuharu Ibaraki, Kimitsu, JP;
Takashi Yamamoto, Kimitsu, JP;
Yoichi Abe, Futtsu, JP;
Shigeki Takahashi, Futtsu, JP;
Kazunori Nagai, Futtsu, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The present invention provides: a method for drying compacts containing water so as not to cause explosion and powdering; a method for reducing the compacts after being dried with great efficiency in a rotary-hearth-type reducing furnace; and a rotary-hearth-type metal reducing furnace. In the present invention, when compacts comprising powder containing metal oxide and carbon are dried, the critical value of a water evaporation rate, beyond which explosion occurs, is determined from the size and porosity of the compacts, then the water evaporation rate is controlled to a value not exceeding the critical value and, by so doing, the increase in the internal pressure of the compacts caused by the generation of water vapor is prevented. By the method, the explosion and cracking of the compacts are prevented. Further, when compacts are dried in a rotary-hearth-type reducing furnace, explosion is prevented by controlling the heat supply rate to the compacts through the above method and successively the compacts are incinerated and reduced in the same furnace.