Jaw crusher, which has the advantages of high crushing ratio, easy operation and convenient maintenance, is used in the industries of building, mining and cement, etc. However, during the crushing process, jaw crusher may produce a large amount of dust, which will cause terrible environmental pollution.
With the step by step follow-up of environmental supervision, it is urgent to solve the dust problem. At present, dust removal becomes a common phenomenon in the rocks crushing process, and also be a difficult problem for the mining industry.
Mining dust not only pollutes our environment and harms workers' physical health, but also accelerates abrasion and shortens the service life of jaw crusher. Therefore, it is very necessary and important to control dust.
So what are the reasons of dust generation and what can we do to efficiently reduce the dust production?
The reasons for dust generation of jaw crusher
- While the crusher rotor rotates at a high speed to crush the stone materials, it constantly discharges a large amount of air from the upper chute of the crusher to the tail of the machine, forming a high-pressure airflow. The dust flows out with the high-pressure airflow, and part of the dust is sucked away by the dust collector, while the part not sucked away has a large amount of dust, which is flowed away from the cracks of the lower chute and discharging into the atmosphere.
- The tail chute of the jaw crusher is straight with a large flow area, and high-pressure airflow is easy to pass through here and brings out dust at the same time.
- The dust collectors configured outside the jaw crusher are relatively decentralized, and the dust collection pipes are very long with so many elbows, so that the resistance of dust collection is very large, and at the same time collector will absorb some outside cleaner air from the atmosphere.
- The dust absorbed by the dust collector will be sent back to the belt conveyor, and the dust returned will be immediately blown away by the high-pressure airflow, which will be sucked away by the dust collection pipe, resulting in secondary pollution.
Errors of dust collecting and removal
The dust collecting measure of jaw crusher in the early stage mainly includes two types--spray and dust collecting, and the relevant dust-proof devices are mainly set at the inlet and outlet of crusher. However, the actual dust-proof effect of these methods in the production site is terrible, and the main reasons are:
When the crusher works, it produces dust with a large amount and a high density.
The suction hood is far away from the dust outlet and its angle is inappropriate, which makes dust easy to diffuse and difficult to collect.
The pressure of spraying water is low and the nebulization effect is terrible.
Less spraying devices are set there.
There is no dust-proof device set in the back chamber of the crusher, which makes about 25% of the dust can not be collected.
Dust removal methods
Under this condition, HXJQ Machinery has improved the following aspects of the jaw crusher to reduce the generation of dust.
The structure and techniques have been improved to reduce the generation of dust from its source
In the operation of the jaw crusher, the amount of dust generated has an important relationship with the throughput of the ore and the crushing efficiency of jaw crushers. The density of the tooth, the tooth shape and the tightness degree and wear degree of the jaw plate are the important factors that affect the efficiency of crushing.
Usually, there is a screen before the crushing chamber, and only the ore larger than the screen size can enter the crusher. However, under the existing conditions, the screen is very easy to be blocked. If the screen is not cleaned up in time, a large amount of ore will be blocked in the crusher, so that the ore that can pass through the screen without having to be crushed may make the crusher block. Then the ores are crushed repeatedly, which makes the generation of dust increase.
So in order to better control the source of the dust, it is necessary to promptly eliminate the failure of the screen blockage and reduce the amount of dust generated as much as possible.
Select jaw plate reasonably to improve crushing efficiency
The original jaw plate not only has a small number of teeth but also a large tooth model, which is not conducive to crushing iron ore with high hardness. After analysis and comparison, the jaw plate with three additional teeth may produce less dust in practical application. The crushing efficiency is increased by about 10%, and the amount of dust generated is significantly reduced.
Fastening the jaw plate
The jaw crusher generates frequent impact loads during the operation. The ore and the jaw plate frequently collide and squeeze. During the crushing process, the fixed jaw plate and the movable jaw plate are prone to loosening or falling off.
Once the jaw plate is loose or detached, the crushing efficiency of the crusher will be seriously reduced, causing the ore to block in the crushing chamber for a long time, and the ore and the jaw plate to squeeze repeatedly to generate a large amount of dust. For this reason, it is necessary to fix the jaw plate frequently and to reduce the generation of dust from the source.
Replace the blunt jaw plate in time
When the tooth is blunt, the contact area with the ore is increased The crushing power is consumed in a large amount, and a large amount of dust is also generated.
Improve the traction speed of the ore conveying after the crusher discharge port
Adjusting the subsequent conveying speed of the discharge not only can achieve the best working state of the crusher, but also can achieve the effect of controlling dust.
The practice has proved that under the tolerance range and production capacity of the subsequent processes, the traction speed is appropriately increased, and the dust is less produced.
Improve spray flow
The higher the water pressure, the more effective the dust deposition is, and increasing the spray flow rate can improve the dust reduction efficiency.
In the past, industrial circulating water was used, not only the water pressure was low (0.2 MPa), but also the water quality was poor, and the problem of insufficient spray volume often occurred. The spray nozzle is also very easy to be blocked, and the bad spray effect has a bad influence on controlling the spread of dust.
At present, the dust-proof system is adopted and the independent pump supply system is applied to reduce the amount of dust emission. The water pressure is adjusting to 0.6 MPa or above, and the spray nozzles with good nebulization and large spray angle are selected.
Meanwhile, according to the geographical characteristics of the mine, the natural water is adopted as the water source, which greatly reduces the nozzle clogging.
Reasonably increase the number of spray nozzles
During the operation of the jaw crusher, the dust is mainly produced in the crushing chamber, and internal pressure and relatively obvious airflow are formed in the crushing chamber and the discharge port. Therefore, the generated dust is mainly discharged from the discharging port.
Therefore, it is necessary to effectively control the main dust-discharging port in order to curb the spread of dust. According to the actual situation of the working site, two spray nozzles can be set respectively at three points, so that it can basically reduce dust by about 70%.
Perfect the sites of dust removal facilities
The dust hood of the jaw crusher is adjusted to about one meter from the dust outlet and perpendicular to the dust flow direction, and the fan should be placed at about 1/3 of the front end of the ventilation duct so that the fan can work best.
Humidification treatment of materials
In the actual production process, the humidification treatment of the ore before entering the crusher can effectively prolong the time of dust separation during ore crushing and reduce the dust generation.
There are many types of dust and different properties. Under normal circumstances, the smaller the particle size of the dust, the less likely it is to settle in the air, and the more difficult it is collected.
As the air flows, it causes long-term and large-scale pollution, which does harm to the human body. In addition, there are even explosive hazards for some flammable mine dust. Therefore, we must take the above measures to prevent it.
With the advancement of technology, the crusher technology has also been upgraded several times. At present, HXJQ has successfully designed and manufactured various types of jaw crushers, such as PE jaw crusher, single toggle jaw crusher and mobile jaw crusher, effectively reducing dust pollution caused by the crushing process.
Besides, HXJQ Machinery also produces cone crushers, mobile crushing plant, etc., with good quality and various models. If you have any problem with machine and crushing, welcome to contact us, and we will do our best to your queries.
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