Direct gas burner type furnace

Abstract

A direct gas burner type furnaces for directly heating articles 13 by combustion gas and then exhausting the combustion gas outside the furnace, controls the combustion rate of a gas burner 2 based on the furnace temperature detected by a temperature sensor 3 in the furnace, and controls the rotational speed of an exhaust fan 8 based on the combustion rate to control the exhaust rate of the combustion gas in the furnace. Accordingly, it is possible to exhaust the combustion gas from the furnace in correspondence with the introduction rate of the combustion gas into the furnace and to prevent air at a normal temperature from being sucked into the furnace.

What is claimed is:  
     
         1 . A direct gas burner type furnace for directly heating articles continuously fed into the furnace by combustion gas which gas is then exhausted outside the furnace thereafter, comprising 
 combustion means opening to the interior of the furnace,    a temperature sensor for detecting the furnace temperature,    exhaust fans for discharging the combustion gas from the interior of the furnace to outside the furnace,    combustion rate control means for controlling a combustion rate of the combustion means based on the furnace temperature detected by the temperature sensor, and    exhaust rate control means for controlling an exhaust rate of the combustion gas in the furnace by controlling the exhaust fans based on the combustion rate.    
     
     
         2 . A direct gas burner type furnace as defined by  claim 1 , wherein a circulation fan is provided in the furnace for circulating the combustion gas in the furnace.  
     
     
         3 . A direct gas burner type furnace as defined by  claim 1 , wherein a plurality of said combustion means are provided.  
     
     
         4 . A direct gas burner type furnace as defined by  claim 2 , wherein a plurality of said combustion means are provided.