The reason why the air in the mine can flow is because there is a pressure difference between the air inlet and the air outlet. The power that causes this pressure difference to cause air flow in the mine is called ventilation power. According to different ventilation power, the mine ventilation method can be divided into mechanical ventilation and natural ventilation. 1 ) Mechanical ventilation Mechanical ventilation uses specialized mechanical equipment (fan fans) to promote downhole air flow. Seasonal changes have little effect on ventilation, and the direction of wind flow and air volume can be adjusted. It is a reliable ventilation method used by most mines, and the safety regulations stipulate that underground mines must establish mechanical ventilation systems. Fan fans for mines are available in both axial and centrifugal versions. Figure 1 is a schematic diagram of the working principle of an axial fan, in which the inlet and outlet directions are in line and parallel to the axis. When the working wheel rotates continuously, since the blade is in the shape of a wing and forms a certain angle with the rotating surface, the low-pressure area takes in air after the blade advances; the high-pressure area is generated in front of the blade forward, and the air is driven to advance. Axial Ventilator high efficiency, light weight, the movable blades can be adjusted, has been widely used in metal mines. The disadvantage is that the noise is large and the maintenance is complicated. 2 ) Natural ventilation Natural ventilation relies on natural pressure differentials to cause air to flow. When the heights of the surface positions of the inlet and outlet shafts are different, the mass of the air column in the two wells is different, resulting in a natural pressure difference, also called natural wind pressure. As shown in Fig. 3, the level of the flat mouth is different from the height of the wellhead. In winter, the ground temperature is lower than the downhole temperature, and the ground air density is large. Therefore, the air column AB is heavier than the air column DC , so that the B and C at the same level are subjected to The quality of the air column is different: the air gravity at point B is greater than the air gravity at point C. Therefore, the winter air flows from point B to point C , that is, the wind enters from the flat, and the wellbore goes out. In summer, the ground temperature is higher than the downhole temperature, so the direction of the wind is exactly the opposite of winter. It is not difficult to see that natural ventilation is extremely unstable, and the direction of wind flow and the amount of wind are affected by the season. In spring and autumn, there is little difference in surface downhole temperature, and underground air may not flow. Therefore, natural ventilation can only be used as a supplement to mechanical ventilation. Large Size Film Lamination Machine
The "Three-dragon" brand complete set of equipment for Large Size Film Lamination Machine is sold throughout the country and exported to overseas markets, and now it covers more than 30 countries and regions, such as Russia, Vietnam, Indonesia, Malaysia, Bangladesh, Uzbekistan, Ethiopia, Congo, Nigeria, Syria, etc.
Universal Packing Machinery's growing experience is also culturing our characters and forging our determination and indomitable will. Large Size Film Lamination Machine,High And Low Pressure Film Blower,Fast Speed Plastic Film Laminating Machine,Automatic Plastic Film Laminating Machine Zhejiang Sanlong Universal Machinery Co.,Ltd. , https://www.sanlongmachinery.com
Figure 3 Schematic diagram of natural ventilation
We are pursuing the science and technology of high humanity and intelligence.
Figure 1 Axial fan fan Figure 2 Centrifugal fan fan