The trolley type annealing furnace is usually used to produce high-quality electrical appliances and automobile plates, generally including the following furnace sections: JPF, RTF, SF, SCS, RCS, ES, etc. The latest trolley type annealing furnace adopts advanced energy-saving technologies such as waste gas three-stage waste heat recovery (the first stage waste heat recovery is used to preheat combustion supporting air, the second stage waste heat recovery is used to preheat strip steel, and the third stage waste heat recovery produces superheated water), push-pull combustion system and supporting on / off combustion control system, furnace composite lining, etc.
The steel structure of trolley type annealing furnace mainly includes furnace shell support frame and driving equipment support frame (platform steel structure). Considering the potential expansion and contraction of the furnace shell, the supporting frame of each section of furnace shell and the steel structure of the platform are independent of each other. The bottom roller chamber of each furnace section shall be installed in place first, and four datum columns shall be welded based on its own four corner columns; then the left and right integral end plates shall be welded. On the operation side and the drive side, several independently manufactured side plates shall be welded and installed from bottom to top. Finally, the top roller chamber of the top roller chamber shall be installed with four datum columns, which can be installed and welded with four datum columns of the furnace body to complete trolley type annealing The furnace shell is manufactured and installed with several widened platforms installed on the transmission side for storing the furnace top cover.
According to the working principle of the slow cooling section, the preliminary analysis is that the channel steel is cracked due to the inconsistent thermal expansion. The negative pressure generated by the circulating cooling suction of the circulating fan will bring the weight gas into the furnace, so that the furnace condition will be stable when the oxygen content in the section is too high and the steel specification e7j is not changed. Once the steel specification is changed and the temperature changes frequently, the cracking position will further deteriorate and the furnace condition will be difficult To maintain stability.
When the specification of steel is switched, the temperature difference between the air in and out of the slow cooling section of the hot galvanizing unit is generally required to be about 200K, considering the gap between the cooling air box and the furnace shell, and the high-temperature circulating gas will exchange heat at this gap; on the other hand, if = steel and channel steel on the air duct frame are welded with the furnace shell steel structure, the heat difference between the normal temperature air outside the furnace and the high-temperature gas inside the furnace will be There is a thermal gradient on the corresponding channel steel, or the expansion amount and rigidity of stainless steel expansion n are difficult to meet the temperature difference deformation requirements of the air duct, which will also lead to cracking of the channel steel.
