| OCR Text |
Show 15 Values equivalent to other regenerative burners were obtained in regard to energy saving performance and low N O x emission performance. At present, durability for forge furnace use is being checked. 5. Improvement of regenerative burner system for forge furnaces In the course of working to made the regenerative systems for forge furnaces practical, we worked to improve many other components in each case. Here w e give some examples. 5.1 High efficiency furnace pressure control Furnace pressure control in regenerative burner systems is normally performed by bypassing a part of the exhaust through a flue provided in the furnace body and adjusting the flow rating of by-passed exhaust by the flue damper. In contrast, as shown in Fig. 18, w e adopted a method in which a valve to adjust the exhaust suction flow rating by internal furnace pressure (furnace pressure control valve) is provided in the exhaust line instead of the flue damper. With this method, not only is it unnecessary to build a flue in case of new furnaces, but the energy saving rate increases by several percent with the total exhaust loss becoming smaller although the temperature of the exhaust from the regenerative element rises somewhat as the exhaust escape rate becomes small. However to cope with the increase and decrease of the combustion rating, more precise internal furnace pressure control can be made by providing a exhaust flow control valve besides this furnace pressure control valve to function in synchronization with the air flow control valve for combustion. Furnace pressure controller PIC •- Exhaust 1 0 0 % T Exhaust gas flow control valve Furnace pressure control valve Air flow control valve, j-*'. Air H Qcontrc W-• T/C Furnace temperature conitoiiar JTIC Fig.18 Furnace pressure direct feedback control method |
