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Show 18 5.4 Impulse type regenerative burner system With the direct gas-firing type heat treatment furnace, to make temperature distribution uniform, a high speed burner with which the furnace atmosphere may be readily agitated is often used but since the burner air pressure is high, energy savings by use of high temperature preheated air is difficult. Therefore, by an innovation of the combustion control, w e have devised the "Impulse type regenerative burner system" aiming to achieve a temperature distribution equivalent to that when high speed burners are used while actually using low speed regenerative burners. As shown in Fig. 21, this system involves a number of regenerative burners which number not less than three, by time proportional control. And not only the combustion burners but the burners which suck exhaust, are operated switching on and off in orderly sequence, . By this, x X (x-1) ways of furnace atmosphere flow may be created and levelling of temperature distribution may be made without relying on a high speed burner, and at the same time, energy saving may be achieved. The present system is currently being tested on a car bottom type normalizing furnace (furnace temperature 870°C). In this furnace, a high heat resistance metal honeycomb is used for the regenerator element and an exclusive regenerati burner of a type in which the regenerative element is inserted in the furnace wall w a s developed and used. Among forge furnaces, there are direct fire heat processing combined use type furnaces by which normalizing and annealing are also performed after forging. With this type of furnace, a more uniform distribution of temperature is required compared with normal forge furnaces. Hereafter, it is planned to expand application of the present system to such forge furnaces. Fig. 21 Impulse type regenerative burner |