Hygienic standards of dust content of air in industrial premises and underground workings, approved by the USSR Gossaninspektsiya, are differentiated by type and composition of dust (SN 245-63). They do not take into account a number of factors that affect the amount of dust penetrating into the human body: different altitudes at which mines are located, climatic conditions, the severity of the work performed, the duration of human stay in a dusty environment. ...
One of the sources of pollution of mine air in mine workings with conveyor transport is blowing dust from supports, floor, conveyor belt, etc. As it is known, dust detachment from the dusty surface occurs under the action of aerodynamic forces of the air stream, when the latter exceed the gravity forces of aerosols and molecular forces of attraction of dust particles with dust particles or dust particles with the dusty surface. Knowing the magnitude of these forces and the nature of the interaction of dust particles with the air flow, it is relatively easy to find the velocity of the ventilation jet, at which dust detachment begins in these conditions, i.e. determine the value of the critical velocity of dust detachment. ...