The Traditional Structure and Existing Problems of Coal Screening System in Circulating Fluidized Bed Boiler
First, the traditional design structure of Coal-fired screening system:
The Traditional Design Structure of Coal Screening System for Circulating Fluidized Bed Boiler in Power Plant. The coal screening system is arranged between 5 # and 6 # coal conveyor belts. Coal was sent to the shaker by # 5 belt, after screening, without breaking the coal through the screen and coal hopper fell 6 # coal conveyor belt was sent to finished coal warehouse, the coal need to be crushed slipped from the top of the screen to the primary crusher and then into the secondary crusher and fell to the 6 # coal conveyor belt and was delivered to the finished coal bunker.
Second, Defects of traditional design structure of coal screening system:
Field observation found that: the original design of screening system defects exist, are concentrated in the vibrating screen, there are two main points: First, the form of selection of the wrong screen, the form of the screen is screen plate, that is, in a 3000mm long, 1500mm wide, 10mm thick stainless steel plate made of uniform drilling, aperture size is 12mm; Second, the screen screen surface angle is unreasonable, the sieve screen along the 5 # belt output of the coal flow to the layout and angle of about 20 ° with the horizontal (Figure 1 " "). Vibrating screen to choose such a screen and screen layout angle, the drawback is that: the screen layout angle will leave the conveyor belt coal combustion generated when the kinetic energy and gravitational potential energy to a minimum, the damping effect caused by the 10mm-thick circular sieve hinders the screening speed of the coal and makes the conveying speed of the conveyor belt larger than the sieving speed (or sifting speed) of the vibrating screen. Even the dried raw coal, Will also accumulate in the screen surface, so that the screening system loses the screening function.