Firstly, the temperature of some materials are very high, such as agglomerate, it temperature is 400~600℃, Hot baked sand for 600~800 excess hot pot furnace and electrical dust collector dust bucket up to 300~400℃. Secondly, the material contains sulfur, viscosity, easy to adhere to the inner wall of the conveyor, chain and scraper. In addition, the materials contain toxic fumes, which may cause hazards to the surrounding environment. Therefore, the design of the trough chain conveyer for colored metallurgy must take into full consideration such factors as temperature, strength, abrasion resistance, operational reliability and tightness. In the past, many accidents were caused by design reasons. For example, during the trial production period of jinchuan metallurgy plant, 6 trough chain conveyors suffered from such accidents as chain and fin fracture, scraper deviation and shell deformation. This paper introduces several improvement measures on the design problems of heat resistance trough chain conveyor. The design of Safe device
Because the working condition of the high temperature trough chain conveyor is very harsh, the design of safety device is especially important. By summing up the experience of production practice, a simple and reliable safe installation is designed. The motor is controlled by a limit switch mounted on the tail wheel shaft. A limit plate is installed on the tail wheel shaft with screw spring, and the line opening and closing is fixed in the appropriate position on the tail wheel frame. When the trough chain conveyor is stuck, the spring on the tail wheel is compressed and moved towards the nose. When the distance of movement exceeds the safe distance, the limit plate that installed on the tail wheel shaft pushes the stroke switch contact to the closed position, thus cutting off the power supply of the head of the conveyor to drive the electric machine and the power supply of the feeder, making the whole conveyor stop running. Generally, one stroke switch can be installed in each of the two tail wheel frames and connected together with the two stroke switches. As long as there is one action during the production, the car can be parked, which will enhance the reliability of the safety installation.
Improving the tail structure
The feeding port ususlly be installed in the upper of trough chain conveyor. The material passes through the scraper chain of the upper part and falls to the bottom of the groove. The material with high temperature often clump together. The lump-shaped material is easy to accumulate on the upper chain strip and is taken to the tail wheel with the same chain strip, forming the tail wheel rear pile. The tail wheel too much material will make the tail wheel crowded dead, make it stop turning to create a problem. In order to make the accumulated material in the tail be discharged in time, a grey hopper was added at the lower side of the tail wheel, and a plunger valve was also installed at the lower side of the grey hopper. When the upper chain strip brings the lumpy material to the tail wheel, it falls into the dust bucket. During production, the amount of ash in the hopper can be observed through the inspection hole at the top of the tail wheel. When the ash accumulates to a certain extent, the plunger plate valve can be opened to remove it. This effectively ensures the normal operation of the tail chain wheel.
The solutions of sealing casing and thermal expension
The sealing and thermal expansion of metallurgical heat resistance trough chain conveyor is also one of the problems that must be solved reasonably. In the high temperature, no matter the machine head, machine body or machine tail may be deformation because thermal expansion. And there will be harmful gas leakage from the machine body, pollution environment. The measures we have taken to solve this problem are as following: 1) the head, tail and media casing of trough chain conveyor are all designed as separate structures, with each section connected with bolts. The casing is filled with asbestos of a certain thickness on the bonding surface between the intersections for sealing. This kind of asbestos belt is resistant to both high temperature and abrasion and has some elasticity. After each section of the shell, the thermal expansion amount of each section is reduced, and the stone wool belt is sandwiched in the middle, so that the response force generated by the shell in the case of thermal expansion can be removed. The structure is also easy to disassemble and maintain. 2) when the trough chain conveyor is installed on the ground platform, the connecting bolt between the machine body and the ground foot is changed from the original fixed mode to the pressing plate type that the machine body can slide on the platform. In this way, the shell will not be deformed when the bolt is stuck when it expands. 3) when the trough chain conveyor is hoisted on the prepared ash hopper, consideration should be taken into the machine head support structure installed on the ground platform to remove the thermal expansion response force in both horizontal and vertical directions.