600mm uhp graphite electrode
What are the three temperature zones that can be divided into the tunnel kiln of the 600mm uhp graphite electrode and the characteristics of the tunnel kiln?
The tunnel kiln of uhp graphite electrode can be divided into 3 temperature zones according to the temperature range:
(1) Pre-heating. The carbon billet of the 600 uhp graphite electrode is loaded into the metal sagger and enters the preheating zone with the kiln car until it is heated to 300°C. The required heat comes from the waste flue gas of the high-temperature roasting zone and the hot air sent by the cooling zone after heat exchange. . All waste flue gas after preheating the carbon billet passes through the exhaust holes in the preheating zone, passes through the branch flue, and then merges into the general flue for exhaust.
(2) Roasting belt. There is a burner in the middle of the kiln body. The preheated air from the cooling zone and 600 graphite electrode fuel are mixed and burned to form a high temperature zone, and the carbon billet is roasted and heated. The roasting temperature can reach 850～950℃. (3) Cooling zone. Cool air is fed into the kiln through a cooler to cool the sagger equipped with uhp graphite electrode carbon blanks. The temperature of the product out of the kiln should be lower than 350℃.
The 600mm uhp graphite electrode tunnel kiln specially used for secondary baking of impregnated products has the following characteristics:
(1) The economy is reasonable. The secondary roasting temperature is low, and the production capacity cannot be fully utilized when the ring furnace is used. It is unreasonable from the aspects of technology and economy. However, it is very economical to use the tunnel kiln to carry out the low-temperature secondary roasting.
(2) A faster heating curve can be used and the kiln temperature difference is small. The roasting cycle of the tunnel kiln is only about 80h. Due to the high temperature fan, the flame gas in the kiln is forced to flow, and the temperature difference between the upper and lower sides of the kiln car does not exceed &;20℃.
(3) The volatile matter generated by the impregnant pitch in the impregnated product during roasting can be used as heating fuel, which greatly reduces fuel consumption.
(4) The impregnated product is packed in a special heat-resistant sagger, no filler protection is required. The 600mm uhp graphite electrode carbon billet is loaded and discharged outside the kiln, the production operation is simplified, and the operating environment is good.
(5) The pitch precipitated during the roasting process is deposited on the bottom plate, and the pitch coke formed can be recycled.
(6) High degree of automation, kiln temperature and kiln pressure can be automatically adjusted.
(7) Since the volatile matter generated by the secondary roasting can be fully utilized, no pollution occurs.
(8) The kiln body has a long service life and less maintenance.