The use of scraper conveyor in China began in the 1960s, and the equipment has mature experience in the application of chemical industry, cement, grain and so on. Although the power industry is also used earlier, but because of the fluidity and abrasive properties of slag and fly ash than other materials, the use effect is not good, so for many years has been the use of hydraulic slag, ash transport, so that the loss of water resources is greater. For example, a small power plant below 50MW, the water consumption for hydraulic slag discharge and ash transport is more than 20m3h. In recent years, due to the scarcity of water resources and the deterioration of the environment, in order to save water, save investment, reduce pollution and promote comprehensive utilization, dry slag discharge and ash transport have been mentioned again. At present, the technology of dry slag discharge and ash transport develops rapidly, and has obtained certain social and economic benefits. The remarkable advantages of the scraper conveyor we designed for a thermal power generation in Xinjiang are sealing, wear-resistant, low noise, power saving and high efficiency. The equipment has been used for several years, with excellent technical performance, stable and reliable operation. 1.1 Project Overview
The 3×50MW boiling-bed coal-fired power station was built and put into operation in 1993. The fluidized boiler bed slag is first cooled by the slag cooler and then transported into the scraper conveyor to the slag storage bin. In order to meet the requirements of Party A, the scraper conveyor uses two lines, which are mutually standby.
1.2 Material Characteristics
The material is the boiling boiler bed slag sample provided by FWEC in the United States entrusted by Party A for test firing, and its characteristics are as follows:
Density 0.8~1.2t/m3
Composition C 4.7%, Al2O3 18.6% CaSO4 15.3%, Fe2O3 11.8%
1.3 User Requirements
1. The service life of the whole machine shall not be less than 5 years. 2. Minimize the weight of scraper conveyor under the premise of ensuring the performance, quality, service life and safety and reliability of scraper conveyor. 3, the length and weight of scraper conveyor should meet the requirements of the process layout. 4, scraper conveyor design and manufacturing standards, procedures, specifications must be submitted to the user for approval.
1.4 Main Features scraper conveyor is the scraper conveyor designed by our company for the slag removal system of 3×50 MW boiling-bed coal-fired power station. The design of the machine neither copies the existing drawings at home and abroad, nor copies the existing prototypes at home and abroad, but after full investigation and research, the material characteristics are thoroughly understood, and on the basis of more than 20 years of practical experience of our company, the design with its own characteristics and independent intellectual property rights is made, and its characteristics are as follows.
1, Scraper chain
scraper chain is the most important part of scraper conveyor, the chain rod of the scraper chain is forged chain, using GB 699-88 "high quality carbon structural steel technical conditions" stipulated in 45 steel; The scraper adopts precision casting, the material is ZG 35, and the bottom thickness is increased under the premise that the overall weight is unchanged, so that the bottom strength is increased, and the scraper is not easy to deformation. The pitch of the chain rod of the scraper chain is 200mm, and the pitch of the scraper is 400mm, which is designed because when the head wheel speed is a fixed value, the greater the pitch of the chain, the greater the dynamic load. Under normal circumstances, the speed of the scraper chain determined by the conveyor volume is constant, so the dynamic load of the chain is small when the pitch of the chain rod is reduced. In addition, increasing the spacing of the scraper can also reduce the weight of the chain. Because the horizontal scraper conveyor chain tension is small, so the use of single chain; The inclined scraper conveyor chain tension is larger, so the use of double chain.
2, Tail seal
The tail seal has always been a difficulty with the scraper conveyor. Because the tail shaft of the hot scraper conveyor is not fixed, it brings great difficulty to the tail sealing. The tail sealing device of the scraper conveyor uses adjustable bolts to make the sliding mark always attached to the side wall of the tail shell. At the same time, the sliding plate and the tail shaft bearing seat are artfully connected with the bracket, so that the sliding plate and the tail shaft always move synchronously to ensure the sealing.
3, Water jacket shell
The water jacket shell system is welded with steel plates, and the steel plates and both ends of the flanges are thicker to ensure the necessary strength and rigidity. In addition to the upper cover plate, the steel shell is equipped with water jacket on both sides and at the bottom. Water jacket is a long flat closed cavity welded by steel plate, attached to the two sides of the shell and the bottom below, each cavity is welded with an inlet water pipe and an outlet water pipe, cooling water to reduce the temperature of the material and prevent the shell from heating up too fast and deformation. The water injection pressure of the horizontal middle section of the water jacket is generally between 5×104~20×104Pa, and the water volume is 2~3th. The water injection method of the slag discharge system adopts the parallel countercurrent water injection method (the water flow direction and the material conveying direction are opposite to the countercurrent).
The above is our design of scraper conveyor in the power plant ash discharge design, we are a professional supplier of bulk material conveyor, we attach great importance to engineering design, equipment manufacturing, after-sales service and other projects, we look forward to working with you.