Before understanding the dust removal in the nozzle yard, we should first understand the reasons for the dust in the yard:
1. Dust during the transfer of the upper belt of the limestone stacker. There is a drop of about 2m between the discharge port of the belt conveyor and the feed port of the limestone stacking belt conveyor, and a large amount of dust is formed when the limestone falls.
2. A small amount of dust will be generated when the limestone feeding belt conveyor is running with material. The limestone is transported from the mine to the limestone yard in the factory area through the belt conveyor. The first four belt conveyors are closed throughout the whole process, so no dust can be seen from the book, and the No. 5 belt conveyor is connected to the limestone stacker and cannot be closed. , the dust enters the yard with the belt.
3. Dust during the feeding process of limestone distributing machine. There is a drop of about 2m between the discharge opening at the tail of the limestone stacking belt conveyor and the ground of the stacking yard, and there is also a drop of about 1.5m between the half-stack and the stack, and a large amount of dust is formed when the limestone falls.
The latter two are the main reasons for the high dust concentration in the limestone pre-homogenization yard.
How to use atomizing nozzles to pre-homogenize the comprehensive control measures of dust in the yard
1. The lifting arm where the stacking belt of the limestone stacker is located is lifted and lowered by hydraulic pressure, and a limit switch is installed at the top and bottom of the tail. We first adjusted the lower limit switch within the scope of the equipment to reduce the falling height, but not too much adjustment.
2. The lifting and lowering of the stacking belt of the limestone stacker during the stacking process is controlled by a lead probe with a built-in mercury contact on the head. When the probe touches the stack, it will slowly tilt to make When the mercury contact is turned on, the lift arm will lift the arm until the mercury contact is disconnected. The distance between the lifting arm and the material stack is the distance between the probe and the lifting arm. We adjust this distance to the minimum distance allowed by equipment protection, about 1m.
3. The dust during the transfer process of the upper belt of the limestone stacker cannot be solved on site due to equipment reasons. After analysis, the method of spraying water and humidifying the limestone is used to control the dust. As long as the water is added properly, the humidity of the material will affect the raw material mill. It doesn’t matter much during production
The humidification point is located at the feeding port of the belt conveyor. Drill a well on site, use a submersible pump to pump water, and connect it to the feed port of the No. 5 belt conveyor with a pipeline. At the beginning of the test, an atomizing nozzle was installed, and a manual screw hand valve was used to control the switch of the waterway. A person was responsible for adding and closing water. After the operation test, although the dust was reduced, the effect was not obvious. Finally, increase the number of atomizing nozzles to 4, change the water spray points to 2, and the water spray points are about 1m apart. However, because the material is thick and the belt speed is fast, the sprayed water will only make the surface material too wet, while most of the material below is still dry, and the effect is still not obvious. Moreover, when it is manually controlled by the post personnel, it often happens that the material has been fed for several minutes and the water has not been added. When the water is added, the dust has filled the entire yard, or the material is cut in the middle due to the mine, and the water is turned off after the manual discovery. There was a lot of water running on the belt.
4. A solenoid valve is installed on the pipeline to automatically control the on-off of the waterway, and the manual screw valve is only used to adjust the size of the water spray foot. Change the water spraying position of the nozzle to the feeding port of No. 4 tape machine and the feeding port of No. 5 tape machine. Set 2 atomizing nozzles each, and between the two tape machines is a 2.5m long feeding slot. Doing this The advantage is that it can be humidified repeatedly, and the humidification is uniform without making the material too wet. After improvement, the effect is remarkable.