Ventilatory network

(Figure) The simplest ventilatory networks

VENTILATORY NETWORK OF THE UNDERGROUND MINE (EN: ventilation network; DE: Wetternetz; FR: reseau d'aerage; ES: red de ventilacion; RU: вентиляционная сеть) is the system of the mutually connected underground mine workings within the underground mine, which is ensuring the directional movement of the air for the airing; this system also includes the sources of the suction (the ventilators for the underground mines), the ventilatory regulators and built structures, the ways for the leakage of the air. The movement of the air within the ventilatory network is maintained with the help of the pressure (or rarefaction), which is created by one or several ventilators. The scheme of the ventilatory network includes the ventilatory branches, nodes, and contours.

Within the modern underground coal mines, the ventilatory network contains up to 300-500 branches, while within the underground ore mines, such network contains up to 1000 branches. The major parameters of the ventilatory network (the "ri" dynamic air resistance, the "qi" consumption of the air, and the "hi" losses of the pressure, within each branch), are mutually associated through the relationships of the form "hi = ri • qi2" (the branches with the turbulent movement of the air), "hi = riqi" (the branches with the laminar movement of the air), or "hi = ri • qin(1n2)". The ventilatory network as a whole is characterized by the parameters (in the case of the one ventilator for the main airing): the "Q" total consumption of the air, the "H" total loss of the pressure, the "R" total resistance, which are mutually associated through the equation "H = R • Q2", which is named the characteristic of the ventilatory system.

During the designing of the ventilation for the underground mines, and during the calculation for the ventilatory system, there are usually solved the problems of the two types: for the given "Q" total consumption of the air, and the known "ri" resistance of the individual branches, to determine the consumptions of the air within the each "qi" branch, the "R" total resistance of the ventilatory system, and select one or several ventilators for the main airing within the given underground mine; according to the "qi" and "ri" variables, they determine the parameters for the ventilatory regulators and built structures, which are ensuring the required distribution of the air within the ventilatory system.

The simplest type of the ventilatory system is the ventilatory connections, for which there may be used the exact analytical calculation: the serial connection (see the Figure, a), the parallel connection (see the Figure, b), the diagonal connection (see the Figure, v), and the parallel-serial connection (see the Figure, g). The complicated ventilatory systems are calculated with the help of the analogue (electric) models or computers, using the method of the successive approximations.