In mine workings between air and rock massif, beaten coal, as well as settled dust there is a mass and heat exchange. In the cold season, when air is supplied to the mine without heating and humidification, the process of mass exchange is directed from rocks to air. The amount of moisture released into the atmosphere depends on the moisture content of coal, dust and host rocks, the degree of grinding of coal or rocks, the speed of air movement, its humidity and other factors ...

As a rule, mines in the Far North, which develop coal seams in permafrost conditions, are characterized by seasonal fluctuations in the dust content of the mine atmosphere. In January - February, the content of dust in the air during excavation, loading and transportation of coal reaches the maximum value - hundreds and thousands of milligrams per 1 m3, and in summer it approaches the sanitary norm ...

When driving preparatory coal workings in mines in the permafrost region, air dustiness after blasting reaches hundreds and thousands of milligrams per 1 m3 of air. The dust formed is the most harmful, because on its surface adsorbed molecules of poisonous gaseous decomposition products of explosives, which have a toxic effect accelerating the development of pneumoconiosis ...

It is known that the movement of vessels (cages and skips) in mine shafts increases resistance. According to A. M. Karpov, the resistance increases up to 10% during medium intensity of operation and up to 25% during intensive operation, when increased turbulence of the flow persists even during short pauses. In narrow shafts, the resistance can increase up to 50%.

In order to overcome the resistance of the air pipeline when air moves along it, it is necessary to create a pressure difference at its ends. As is known, in the absence of air leaks, depression ...