According to the hydrodynamics principle, whether it is to exhaust the indoor high temperature or polluted by harmful substances or to transport the outdoor air to the room, the indoor air flow will be formed in essence, and the resistance of doors and windows will be overcome during the air flow. Therefore, it will cause certain power to air, which is necessary for local fans to achieve ventilation. Natural ventilation is to realize air exchange by using the heat pressure or air pressure generated by indoor and outdoor temperature difference.
In the selection of structure, the local fans of the mine mainly adopt two types of structure, direct conduction skylight and indirect conduction type skylight. In practical engineering, direct type has low ventilation efficiency, light, bad rain blocking effect and beautiful appearance. Although indirect ventilation, lighting and rain retaining effect have some improvement, in the design of local fans in the mine, the skylight skeleton needs supporting beams, and the skeleton is also made of sandalwood, which makes the skeleton spacing more dense, manufacturing materials, large labor, high manufacturing cost, difficult installation and long installation cycle.
The local fan of mine is composed of roof structure, arc steel frame, sandalwood strip, color steel plate, auxiliary rod and other parts. The arc structure has stronger wind resistance, reduces the number of skylight frame, and the steel consumption decreases with it. The permanent load of the roof is reduced, which greatly improves the safety performance of the building structure.
