RU2428568C1 - Installation for blowing ventilation of dead working faces - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: installation includes fan, delivery line, inducing and water-spraying device installed on its end. Inducing and water-spraying device includes outlet head with annular outlet slot, receiver and compressed air supply nozzle. In order to increase energy use efficiency of compressed air owing to active mixing of inducing and induced jets, separation effect of inducing jet from convex surface is used in inducing and water-spraying device. Common air jet is passed through two-layer fine-meshed screen before it is emitted to atmosphere of mine working. In order to protect outlet slot against deformations, at HWL (high-water level) impact, inducing and water-spraying device is equipped with deformation-proof flange. Water supply nozzles to inner cavity of the main diffuser are installed on convex surface of the main diffuser at angles of 120 degrees to each other.

EFFECT: higher use efficiency of compressed air energy.

4 cl, 2 dwg

Description

The invention relates to the field of mining and can be used to ventilate deadlocks of mine workings.

A known installation for pressure ventilation of the blind faces of mine workings [Auth. St. No. 661113, 1979, E21F 1/08], including a local ventilation fan (VMP), a discharge pipe (NT) and an ejection-water spray device consisting of a confuser equipped with an outlet head (ring nozzle made in the form of a profiled sleeve) with a receiver ( with an internal annular cavity), an outlet gap formed by laying between the flange and the annular sleeve, a convex surface and fittings for supplying compressed air and water.

A series of dependents on [Avt. St. No. 661113, 1979, E21F 1/08] modifications, for example [Aut. St. No. 846757, 1981, E21F 1/08, Aut. St. No. 941617, 1982, E21F 1/08, Aut. St. No. 1167350, 1985, E21F 1/08], the ejection-water spray devices of which contain the same parts.

All known installations, namely their ejection devices, have two drawbacks: one is obvious; the second is hidden.

1. The outlet slot is located in the immediate vicinity of the outlet head cut (profiled sleeve cut) from the dead end face. As a result, an air stream moving inside an NT under the action of a high-frequency magnetic field, having a formed (turbulent) velocity diagram, falls into the region of acceleration, caused in part by narrowing of the cross section due to the presence of a confuser, but mainly due to rarefaction in the exhaust head due to the peripheral outflow of compressed air from the outlet slit and loses the previous plot, since the speed at the inner walls of the outlet head (velocity of the ejection jet) is many times higher than the velocity on the axis of the flow (velocity of the ejected jet). To smooth the plot of the velocity of the general jet, a pipe section (mixing chamber) of at least 3 meters in length (preferably a diffuser) or a hydrodynamic lattice in the flow path is necessary. None of these are known devices. An aerodynamically unformed jet is immediately released into the open working space, which prevents the device’s efficiency (efficiency) from achieving a higher value due to the additional work performed by the compressed air energy on mixing the jets during the formation of an aerodynamically normal velocity diagram before releasing the general jet into the atmosphere.

2. All known ejection-water spray devices (confuser with ejection nozzle and nozzle for water supply) are very massive - 25-30 kg. The authors rightly believed that a massive device is less susceptible to shock air waves. At present, the amount of explosive explosive (EX), when driving a dead-end mine, reaches 24 kg (not 10 kg, as before) and an air-blast is formed of such a value that a fine deformation occurs from impacts of the exhaust head on the wall of the mine working (0.15 mm) of the outlet gap, which leads to an uneven release of compressed air around the perimeter of the gap, to a violation of the concentric uniformity of the flow and, as a result, also to a decrease in the efficiency of the device.

The objective of the invention is to increase the efficiency of use of energy of compressed air by providing hydrodynamic normalization of the plot of the velocity of the common jet discharged into the open working space towards the dead end and protecting the outlet slit from deformation when exposed to air blast due to the rejection of the confuser and the use of a profiled diffuser equipped with an anti-deformation flange .

The problem is solved in that the massive but fundamentally unnecessary confuser is completely abandoned, and the NT stream, accelerated by the vacuum in the exhaust head, is not immediately released into the atmosphere of the mine, but is passed through a receiving diffuser passing through the convex surface to the main diffuser equipped with exit two-layer aerodynamic mesh. The length of the receiving diffuser is chosen so that the ejection jet in it has time to increase in the transverse size due to the suction of air from the NT jet to the size of the radius of curvature of the convex surface [Zelenetskiy VA, Chirkov Yu.S. On the continuous flow of gas along a convex surface. / FTPRPI, No. 1, 1989, pp. 73-79], then when moving along this surface the jet breaks off by centrifugal force into the NT jet, mixes with it in the main diffuser, and after the entire stream passes through the two-layer aerodynamic grid, it flows into the atmosphere with hydrodynamic normalized (turbulent) velocity profile. A jet with a monochromatic turbulent structure has a higher efficiency of using the energy of compressed air than in the prototype and its analogues, since it does more work on transferring energy and momentum from the ejecting jet to the ejected main diffuser, which acts as a mixing chamber.

Both diffusers are equipped with flanges that connect using bolts through a rubber gasket. The outer diameter of the flanges exceeds the outer diameter of the exhaust head. Thus, this compound is an anti-deformation flange. This flange takes the first impact on the wall of the mine from the impact of air-blast on the device, thereby protecting the outlet head with a thin outlet slit from the strongest air-blast effect.

The operational advantage of the proposed device is that its mass is 15 kg less than the mass of the device as. No. 661113, primarily due to the refusal to use the confuser (it is advisable to use the confuser only as a passive accelerator). As the main diffuser, you can use the standardized fire-fighting foam generator GPS-600, equipped with a flange.

Water in the internal cavity of the main diffuser, if necessary, dust suppression in the face, is supplied through fittings mounted on a convex surface at angles of 120 degrees to each other.

The NT is attached to the proposed device in a recess formed by the junction of the exhaust head with a receiving diffuser.

Figure 1 schematically shows the proposed installation; figure 2 - node I.

The installation includes a fan 1, a pipe 2, an ejection device 3, consisting of an exhaust head and a profiled diffuser. The outlet head is formed by a bolted connection 4 of the flange 5 with a sleeve 6 containing an internal toroidal cavity 7 and a convex surface 8, through a gasket 9 to form an outlet gap 10, the outlet head comprising a fitting 11 with a pipe 12 for supplying compressed air to the cavity 7 and a mounting ring 13. The profiled diffuser is formed by the serial connection of the receiving 14 and the main 15 diffusers by bolting 16 flanges 17 and 18 through a rubber gasket 19. The diffuser 15 has a convex surface 20 and contains a piece s water inlet 21 in its inner cavity, and the mesh 22. Attachment of diffusers to the flanges and to the discharge head by means of welding.

Installation for blowing ventilation blind faces works as follows.

Fresh air sucked in from the air supply by the fan is piped to the bottom of the dead end. Passing through the ejection device, the fan jet is subjected to acceleration caused by the discharge created in the exhaust head, flowing out at high speed (up to 200 or more m / s) from the exhaust gap with compressed air. A thin stream of compressed air, enveloping the convex surface of the exhaust head, rushes into the receiving diffuser along its walls, drawing in air from the fan stream and, increasing in the transverse size, reaches the convex surface of the main diffuser, begins to envelop it, but the radius of curvature of the convex surface is chosen so that where centrifugal forces tear off the wall jet, dropping it inside the fan jet. Further, in the main diffuser, both jets (ejecting - wall and ejected - fan jet) are actively mixed and, passing through a multilayer, fine-meshed network acting as a hydrodynamic lattice, a common jet with a monochromatic turbulent structure flows into the working space towards the dead end. Such a jet is the most stable and long-range.

The presence of three nozzles 21 allows you to organize such a flow of water at which the most effective dust suppression of a finely dispersed air-water mixture is achieved.

The use of an ejection device at the end of the discharge ventilation pipe is equivalent to a decrease in its aerodynamic drag, which allows one to increase the flow rate of air supplied to the bottom by 1.5 times or more and, as a result, increase the distance between the end of the pipe and the bottom.

Claims (4)

1. Installation for blowing ventilation of blind faces of mine workings, including a fan, a blowing pipe, an ejecting water spray device containing a discharge head with an annular discharge slot, a receiver and a fitting for supplying compressed air, which is installed at the end of the discharge pipe and serves to release a common jet into the atmosphere of the mine working towards a dead end, characterized in that for the normalization of the plot of the speed of the general stream, an ejecting water-spraying device The property includes a profiled two-stage diffuser formed by the serial connection of the receiving and main diffusers, while the receiving diffuser passes through a toroidal convex surface into the main diffuser, equipped with a two-layer fine-mesh mesh at the outlet, and the length of the receiving diffuser is such that the ejection jet in it has time to increase in the transverse size due to the suction of air from the jet of the discharge pipe to the size of the radius of curvature of the convex surface, which ensures the separation of projected onto the jet from the convex surface, it garbage flow to the center and further mixing with the ejected stream in the interior space of the diffuser core. 2. Installation according to claim 1, characterized in that the ejection water spray device is equipped with an anti-deformation flange formed by flanges of the receiving and main diffusers connected through a rubber gasket, and the outer diameter of the flange exceeds the outer diameter of the outlet head. 3. Installation according to claim 2, characterized in that on the convex surface of the main diffuser there are mounted fittings at angles of 120 ° to each other for supplying water to the internal cavity of the main diffuser. 4. Installation according to claim 3, characterized in that in the recess formed by the junction of the exhaust head with a receiving diffuser, a discharge pipe is attached.

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