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 and 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 high temperature trough/drag belt conveyor. The speed of chain
The chain speed of trough chain conveyor is one of key points to determine its normal operation. The speed of the chain mainly depends on the nature of the materials transported, the service life of the equipment and the power consumption.The materials transported by metallurgical plant include Hot calcine, hot dust, agglomerate, hot return material, hot concentrate after drying, etc.Conveyor chain speed has four kinds, namely 0.16 m/s, 0.20 m/s, 0.25 m/s, 0.32 m/s. For the above materials, even if the lowest chain speed 0.16 /s is selected, this value is too high. For example, the chain speed of trough chain conveyor used by zhongyuan gold smelting plant for conveying hot dust was 0.16 m/s in the original design. During the trial production, due to the high temperature of dust, large amount of ash, the conveyor in such a high speed of operation wear very fast, chain break accidents often occur, and the scraper produced in the movement of voice is very loud, not to stop maintenance. The speed of the chain will be slowed down to reduce the wear of the scraper, the noise is also significantly reduced. After comparison, it is found that the high temperature resistant trough chain conveyor introduced from abroad has a relatively low speed. For example, the speed of trough chain conveyor chain introduced by northwest lead and zinc plant from Germany is 0. 05 m/s. It can be concluded that the speed of colored smelting high temperature trough chain conveyor chain should not exceed 0.05 m/s.
Trough/drag chain conveyor chain mainly has the roller chain, die forging chain and double - plate chain. The chain plate is connected with pin shaft, and the scraper and chain plate are welded. The shortcoming of pin shaft connection is that the opening pin face on the pin shaft is small, and exposed, directly in contact with the material, easy to be worn by the material, make fall off, and make the pin shaft from the chain plate back into the broken chain. During operation, the scraper and the chain plate will sometimes fall off due to welding defects. A new type of high temperature embedded scraper chain introduced from abroad. The inner link and the outer link are made by die forging. The material is made of heat-resistant alloy steel with good abrasion resistance. The scraper is connected to the inner link with a bolt, and the whole scraper chain has no welding points, all of which are detachable structures. Installation and maintenance is very convenient. The back type is adopted for the combination of the chain wheel and the chain bar. The inner chain ring and the outer chain ring are interlaced with each other. The outer chain ring is engaged with the teeth of the wheel. The teeth of this kind of chain wheel is reduced by one half than that of the regular chain wheel. The strength of the chain wheel is high, the service life is long, and the transmission is smooth.
Driving device
The drive installation of trough/drag chain conveyor working under high temperature is easy to be damaged. This is because at high temperature traction chain elongation increase, mechanical wear will also add weight. Traditional trough chain conveyor generally no hanging sprocket, only by the tail tensioning installed tension to adjust the tension of the chain. Due to the long distance between the tail and the head, the self-weight of the chain itself and the weight of the material pressed on the chain have a great friction force. The tension force of the tail part can act on the head is very small, even zero. This head will still produce a heap chain appearance. If there are too many chains, the chains will get stuck in the gap between the sprocket and the chain slide, causing damage to the driving device. The overhanging sprocket above the chain wheel of the driving device can effectively solve the problem of chain stacking and chain sticking. After the addition of the chain wheel chain running track has a section of free extension of the catenary. When the chain is stretched by high temperature, the chain can be relaxed and adjusted automatically, which will not produce stuck phenomenon, thus ensuring the smooth and reliable operation of the chain. In order to ensure that catenary can be adjusted automatically in the process of operation, it is necessary to note that the retaining chain has an appropriate tightness degree during installation.