Patent ID: 6609906
Filing Date: 2003-08-26
Classification: C21D,F27B,F27D

Abstract:
An adjustable ratio control system for a furnace with a plurality of workpieces located within the furnace, comprisinga sensor that determines the temperature of each of the workpieces; and a controller that controls the temperature of an atmosphere of the furnace, wherein a first workpiece with a lower work temperature is heated at a higher rate than a second workpiece with a higher work temperature and the first workpiece and surrounding atmosphere is in a first zone and the second workpiece and surrounding atmosphere is in a second zone where the temperature of a zone is determined by the following formula AIR&it;â€ƒ&it;SP=Î”&it;â€ƒ&it;t&af;(Î”&it;â€ƒ&it;tÎ”&it;â€ƒ&it;t&it;â€ƒ&it;max)&it;R+WSPâ€ƒwhere: AIR SP is equal to the temperature to be established within a zone; &Dgr;t is equal to the temperature difference between an annealing temperature and a current work temperature of the workpiece; &Dgr;tmax is equal to the maximum temperature difference between an annealing temperature and a current work temperature among the plurality of the workpieces; R is equal to a preset ratio and WSP is equal the annealing temperature.