The igniter of the sintering machine built in China in the 1950s is generally modified according to the standard design of the Soviet Union, using the DW-III ring-slit low-pressure vortex burner (Fig. 1).

This burner as compared with a conventional burner used: 1) mixture suitable for combustion of coal gas, coke oven gas and the blast furnace gas clean, 2) better mixed, 3) and in front of the gas burner than the air pressure low. According to the results of long-term use in China, it is found that the burner has the following disadvantages: 1) The number of burners of the ignition furnace is small, for example, five furnaces per 50 m ² sintering machine, two in the front row, two rear rows, staggered arrangement, ignition When the entire surface of the sintered material is heated unevenly, if the ignition intensity is increased, the phenomenon of over-burning may occur under the burner. 2) The capacity of a single burner is large, and the air gas is not easy to adjust. If the adjustment is not good, the gas is not completely burned, and the oxygen content of the exhaust gas is lowered. 3) The ignition time is short, which is incompatible with the production trend of increasing the layer at that time. 4) High calorie consumption.
China uses a thick layer sintering process, the old igniter is not suitable. In order to improve the surface quality of the sinter and reduce the solid fuel consumption, in the late 1970s, the development of new igniters and holding furnaces was started. 1) Add a holding furnace, 2) The trolley baffle is wrapped in the furnace to make the igniter and the workshop tightly sealed, and 3) to be a small-diameter casing type swirling burner. The representative one is the igniter of the WISCO 90 m ² sintering machine put into operation in August 1984. The characteristics of the igniter are shown in Fig. 2.

[next]

The igniter is a box-shaped hood structure, which is tightly sealed to the trolley, and adopts a composite lining and an anchoring structure. The ignition burner used is of a hybrid type, that is, a strong swirling structure in which the swirling fin is axially mounted in the burner, and a hole is opened in the burner head, and part of the air is premixed with the gas to improve the mixing effect. Since there is no old snail swirl mechanism, the burner is smaller in size and lighter in weight (Fig. 3).

The advantages of the igniter are as follows: 1) The lateral ignition is uniform, the heat preservation effect is good, the surface sinter ore drum index is increased by 1 to 2.5%, and the yield is increased by 2 to 4%. 2) The gas is completely burned, and the amount of heat dissipated to the outside is small. Compared with the old ignition and holding furnace, it can save 15 to 25% of gas and 3 to 5% of solid fuel. 3) The life of the lining can be extended and the maintenance is convenient. The disadvantage is that the gas consumption is higher than that of foreign advanced plants, and the per ton of sintered ore reaches 1.67~1.88× ^{10 5} kJ (3.97~4.48×10 ⁴ kcal).
In 1985, WISCO improved the ignition operation process, and adopted the method of low temperature and low negative pressure to remove the throttle flap of the lower bellows of the igniter, and then took it to the water seal tank to reduce the ignition negative pressure from 7845 to 8826Pa to 3924-4903. when Pa ignition temperature drop from 1250 deg.] C to 1100 ~ 1150 ℃, reducing the amount of gas 1000 to 1200 ^m3 / d, less than the original 25% to 35%. At this time, the ignition surface is black, no over-melting, and the entire surface is uniformly ignited, and the ideal effect of greatly reducing the gas consumption and ensuring the ignition quality is obtained. The measured surface sinter strength decreased significantly, the drum index decreased by about 3%, and the <5 mm grain size increased by 6% after falling, but the surface sinter accounted only about 1/8 of the total sinter ore, which affected the quality of the sinter. Very limited, so there is no change in the sinter drum index and return volume. On the contrary, the gas permeability of the layer is improved due to the absence of over-melting on the surface of the layer.
In recent years, the height of the material level of foreign advanced sintering plants has reached 500-600 mm. The height of the material in individual sintering plants in Japan has reached 750 mm, and the speed of trolleys has been reduced from 5 m/min to 2 m/min. The material layer increases and continues to increase. Although the resistance of the material layer increases and the vertical velocity decreases, the yield at the time of the Taiwanese market is not significantly reduced due to the increase in the yield. Since some plants slump steel industry, the production of the sintering machine in a low speed state, seeks to reduce the fuel consumption to achieve lower costs sinter, based on the above actual situation, low power igniter emerged.

 Pump valve accessories precision casting or pump valve accessories investment casting, silica sol process. It is a casting process with little or no cutting.