SU1399476A1 - Method of airing mines - Google Patents

Abstract

This invention relates to the mining industry. The purpose of the invention is to reduce the ventilation time after mass explosions. In the mines, polluted air is removed with the help of main ventilation fans. Ventilation doors are installed in the area of the point of zero depression. Before producing a mass explosion, energy is stored in the air supplied by the main ventilation fan by closing the doors. After the production of a mass explosion, a pulse of air movement is created by opening them. After the estimated airing time has passed, the content of poisonous explosive gases is measured before the workers are allowed into the faces. and with

Description

This invention relates to the mining industry and can be used to ventilate underground mines after massive explosions.

The aim of the invention is to reduce the time of ventilation of mines after mass explosions, large losses in the operation time of mining mines, the cost of airing,

To ventilate the mines after the mass explosions, the proposed method determines the calculated parameters of the pulsed aeration and installs the ventilation doors or vents by conventional means, closes them before the mass explosion during the charging of explosives, and after the explosion opens the ventilation devices and after the estimated time of winding, the content of poisoned WB gases is measured before the workers are allowed into the faces.

Overpressure or underpressure in the mining system of mine chambers after closing the ventilation doors will amount to 9b,

where PO is atmospheric pressure, Pa; hg - maximum depression of the fan, Pa.

According to the equation of state of the gas, the time in which the pressure or vacuum in the mine reaches Ru will be

t J3-1 5-hj.yiyi

Po () Q,) ()

where V is the total volume of mine workings from the VGP to the ventilation doors, T is the air temperature in the mine. TO;

LT is the increment of air temperature in the mine during a mass explosion. TO;

Qg is the productivity of AIV during the normal mode of ventilation of the mine, Qg is the productivity of AIV during

head 0.9hg, Q l) t air leak in the mine and on

VGP, MVc.

According to clause 138 of the Uniform Safety Rules for the development of ore, non-metallic and placer deposits using the underground method, the time may be up to 2 hours,

The average air velocity in the mine workings after opening the ventilation doors according to the equation

Rts-Ro N (1

where I am the coefficient of local resistance to sudden expansion; p is the density of mine air,

kg / m;

V — air velocity through the opening with the vent door open, m / s; V / 5 - air velocity

by speeding up, will be at, 2 kg / m

and

(s-s)

where S, is the cross-sectional area

door aperture, S is the cross-sectional area of generation at the door installation site, m

Duration of the impulse soy-, tavit

. , V W 1 (S-Sj)

o, 6Tvr:; - s, s /

five

0

five

Q

five

GDI S is the cross-sectional area of the mine workings along the outgoing air flow, m. The concentration of explosive gases in the outgoing pulse at the end of the pulse, according to the mass transfer equation, will be

С с „(1 - bts.,

n

where V is the volume of workings of blocks polluted with gas emissions of explosives, cubic meters; Kj, is the diffusion coefficient of gases,

is 0.9;

Cp - the initial concentration of explosive gases after a massive explosion,

 lOMEVp + V p -bVj

where A is the mass of explosive simultaneously explosive, kg;

 - coefficient of voidness of broken ore or rock mass; VP is the block volume occupied by the broken ore or ore mass and overburden, m; Vj. - free from the ore mass, the volume of blocks in the open refining space,

С - permissible concentration of conditional carbon monoxide before the workers are allowed into the faces, is equal to 0.00008 m / m j b - gas content of the explosive in terms of conventional carbon monoxide, l / k

The time of ventilation of the mine to the permissible concentration with conditional carbon monoxide with the proposed method of ventilation will be

2Vji f Co-Vc

 ,

Where

QM air flow during normal ventilation mode, m / s.

Reducing the time of ventilation of the mine with the proposed pulsed method of ventilation compared to the known will be

NC

-t ,, t

2V.

IJ (51 QH

"-7k7y1 Q

VC

wed

de ty - required ventilation time with enhanced ventilation mode (limestone method), s;

Q — air flow in case of enhanced ventilation mode, m / s. In the present invention, the time for reducing the content of explosive gases in mining mines to the permissible time is reduced by more than one shift, and the required power of the AIV is reduced compared to the known 1.5-1.7 times.

Claims (1)

Invention Formula 20 The way of ventilation of the mines, including the supply of fresh air to the shaft 15, removal of polluted air with the help of main ventilation fans and installation in the workings of ventilation doors, characterized in that, in order to reduce the ventilation time after mass explosions, ventilation doors are installed in the zone of zero point the depressions and before the production of the mass explosion, the energy of the air supplied by the main ventilation fan is accumulated by closing the doors, and after the production ssovogo explosion soz- provide air movement through pulse 2Q opening them.