SU1432249A1 - Method of suppressing the dust and gases in blasting work in open mines - Google Patents

Abstract

The invention relates to the lateral industry. The purpose of the invention is to increase the efficiency of suppressing dust and gases, preventing the loss of minerals and pollution of the environment by localizing an ascending plasma cloud. On the gas-gas cloud, there are air-jet streams from at least three self-propelled fan systems, evenly dispersed around the center of the bombed unit at a safe place. The axes of the air jets supplied by each unit are directed tangentially to the lateral surface of the ascending pie-gas cloud with the formation of a closed contour at the intersection points of these axes located in the same horizontal plane. The air stream is raised in a vertical plane with a speed equal to the rate of rise of the pie-gas cloud. Water jets serve simultaneously. With air in the direction from top to down towards the rising pie-gas cloud. In the presence of wind, one of the fan installations is placed on a line passing through the center of the exploding unit and perpendicular to the direction of the wind. The axis of the air jet is directed towards the wind flow at an angle determined by a mathematical formula. 1 hp f-ly, 2 ill. (L 00

Description

FIELD OF THE INVENTION The invention relates to the mining industry and can be used to suppress the drinking and gases

in blasting operations in quarries, mostly deep

and with large dimensions on the surface of the career floor.

The purpose of the invention is to increase the efficiency of suppressing food and gases,

Preventing the loss of minerals and environmental pollution by localizing a rising dust and gas cloud.

Fig. 1 is a plan view of the method implementation, top view; in fig. 2 shows section A-A in FIG. one.

The method is carried out as follows.

Before an explosion, at least three fan sets are installed at a safe distance on the same horizon around the horizon. At this axis of the air jets 2 of the tal 1 installations direct tangentially to the lateral surface of the rising dust and gas clouds 15 with all the axes of the air jets lying in the same horizontal plane .

Example. The open pit has the following parameters: depth H 108 m; length and width over the top 1000x1000 20 height of the ledge 12 m. Dimensions of the air block 60 to 12 l 50 m. To create water-air jets take the installation of DCS-1000 with a fan

thirty

ki 1 at points located on line 25 to create air x conducted through the center of the exploding block and making up an angle 120 at one intersection point. At the time of the explosion, turn on all three installations 1 and start air 2 and water 3 jets. In this case, the axes of the air jets 2 are directed in the same horizontal plane tangentially to the side surface of the ascending dust and gas cloud 4. Then, with the ascent of the dust and gas cloud 4, the air jets 2 are raised at a speed corresponding to the speed of the ascent of the dust and gas cloud. Simultaneously with the supply of air jets 2, water jets 3 are supplied from all three installations 1 from top to bottom towards the rising dust and dust cloud 4. In the presence of wind, the first installation 1 is installed at a safe distance from the exploding unit along a line perpendicular to the direction wind, and the axis of the air jet 2 is directed towards the wind flow at an angle ot from the line perpendicular to the direction of the wind, the magnitude of which is calculated from the expression

jet. The daily capacity of the open pit is 3,000 tons. The number of explosions per week is 3. The amount of explosive explosives in the block is 200 tons. The block is located at the bottom of the open pit, horizon +125. At the time of the explosion of the proposed method, the cross-section of the n-gas cloud can be reduced by 30–40 m versus 200–180 m. The volume of the gas-free dust cloud is reduced by five times due to the narrowing of the localization time. three times, while preventing the loss of a useful claim and contamination of the environment. The magnitude of the safe distance Rgg, in the management of mass explosions of quarries, is 200-250 m. Suppose, for example, the value of the velocity of the lateral wind d5 V 2 m / s, the structure factor

jet and 0.07. The range for this fan installation is 350 m, i.e. condition is met

35

40

R r

Without

Starting speed

air jet U 162 m / s, the initial radius of the cross section of the jet R 7.2 m.

Calculate for the specified expression the value of the angle jL

Rgea- a "v

-j fc I Q 1 n --3r or it .. “..

oi.- arcsin. Up. R

R

Bw

- safe distance from the installation to the unit to be exploded, m;

a is the jet structure ratio (a 0.06-0.07); V is the velocity of the lateral-5th wind side, m / s;

and - the initial exit velocity of the supplied air jet, m / s;

Rj, is the radius of the initial cross section of 10 jet, m.

In this case, the axes of the air jets 2 of the remaining units 1 are also directed tangentially to the side surface of the ascending dust and gas cloud 4, 15 with all the axes of the air jets lying in the same horizontal plane.

Example. The open pit has the following parameters: depth H 108 m; length and width at the top 1000x1000 m; The height of the ledge is 12 m. The dimensions of the block to be blown are 60 to 12 l 50 m. To create water-air jets, the installation of the DCS-1000 with a fan

 to create air

jet. The daily capacity of the open pit is 3,000 tons. The number of explosions per week is 3. The amount of explosive explosives in the block is 200 tons. The block is located at the bottom of the open pit, horizon +125. At the time of the explosion of the proposed method, the cross-section of the dust-gas cloud can be reduced to 30-40 m against 200-180 m. The volume of the dust-gas cloud due to contraction and localization is reduced five times. The time of suppression of flume and gases before the MPC is reduced three times in comparison with the known method, thus preventing the loss of minerals and pollution of the environment. The magnitude of the safe distance Rgg when conducting mass explosions in quarries is 200-250 m. Let the value of the side wind velocity V 2 m / s, the structure coefficient

jet and 0.07. The range of the ventilator installed is 350 m, i.e. condition is met

 to create air

R r

Without

The initial velocity of the supplied air jet is U 162 m / s, the initial radius of the jet cross section is R 7.2 m.

Calculate for the specified expression the value of the angle jL

55

ei s arcsin

250. 0.38 162 772

 arcsin 0.07896 4.5 ° 5

Then, the required feed angle for full localization of the ascending dust-gas cloud must be at least 5, otherwise the supplied air jet may not reach the dust-gas cloud, thereby preventing its localization.

Claims (2)

1. A method of suppressing dust and gases during blasting in quarries, including the impact on the dust-gas cloud by air-water jets of at least three self-propelled fan-installations, evenly dispersed around the center of the exploding unit at a safe distance, characterized in in order to increase the efficiency of suppressing dust and gases, preventing the loss of minerals and pollution of the environment by localizing the rising dust-gas cloud, the axis of the air jets supplied to each fan installation is directed tangentially to the side surface of the rising pinch-gas cloud with the formation of a closed contour at the intersection points of these axes located in the same horizontal plane, while the air jet is raised in the vertical planes with a speed equal to the speed of the rise of the piegas cloud, and water jets are simultaneously supplied with air from top to bottom towards the rising dust-gas cloud. 2. Method POP.1, characterized in that 1S of increasing the efficiency of suppressing dust and gas in the presence of wind, one of the fan installations is placed on a line passing through the center of the block being lifted and perpendicular to the wind direction, and the axis of the air jet of this installation they are directed towards the wind flow at an angle "L, determined from the ratio oL arcsin ..l 0.38-RO RO de r 6ei a V u. R. safety distance from the installation to the unit being shot, m; coefficient of jet structure (a 0.05-0.07); side wind speed, m / s; the initial speed of the exit of the supplied air stream, m / s; the radius of the initial cross section of the jet, m