CN102979552B - Device for preventing coal from burning spontaneously and rapidly extinguishing under coal mine and working method thereof - Google Patents

Abstract

The invention discloses an underground coal mine prevention and control coal spontaneous combustion and rapid fire extinguishing device and working method, which comprises a cylindrical foam shell with two ends narrowed; There is an inlet of foam stock solution; the other end of the foaming shell is connected with a foam output pipe; 6 to 8 sets of spiral blades are arranged at intervals on the hollow shaft of the inner axis of the foaming shell, and air outlet holes are arranged between the spiral blades. The angle between the direction of rotation and the axial direction of the hollow shaft is 45-60 degrees, the direction of rotation of each group of helical blades is the same, and the direction of rotation of two adjacent groups is opposite. In the invention, the mixture is foamed twice, so that the foaming ratio is rapidly increased to 50-150 times in a short period of time, so as to achieve the purposes of preventing coal spontaneous combustion and quickly extinguishing fire.

Description

Underground coal mine prevention and control coal spontaneous combustion and rapid fire extinguishing device and its working method

technical field

The invention relates to a device for preventing and controlling coal spontaneous combustion and a rapid fire extinguishing device, especially for preventing and controlling coal spontaneous combustion and a rapid fire extinguishing device for underground coal mines

Background technique

Under certain conditions, coal left in goafs in coal mines is prone to spontaneous combustion fires, and the effective way to extinguish them is to spray gel foam.

The currently used foam generators mainly include mesh foamers for firefighting, which consist of an air compressor, a pressure vessel, a foaming cylinder with a metal grid and gas-liquid pipelines. This kind of foamer requires an external power source , Not suitable for underground fire prevention and extinguishing operations in coal mines.

Patent No. 02148411.2 "Three-phase foam generating device for preventing spontaneous combustion of coal" applied by China University of Mining and Technology, which includes three-phase mixture (yellow mud or fly ash slurry and foaming agent) feeding pipe, mixer and venturi tube The barrel of the foamer, the mixer is equipped with multiple barrier plates, the barrel of the foamer is provided with a pipe for injecting into the throat of the Venturi tube, there is a gap around the Venturi tube for introducing gas, and the inlet of the Venturi tube is provided Jet regulator, the tail of the foamer cylinder is equipped with an adjustable collector slideway; it relies on the negative pressure generated by the material in the Venturi tube to introduce gas, thereby generating a three-phase mixture foam, which is used to prevent coal spontaneous combustion fires in coal mines. This device relies on the mixture of yellow mud, fly ash and other foams to protect the coal, so as to achieve the effect of preventing spontaneous combustion of coal. Its shortcomings: First, the three-phase foam produced by the mixture of yellow mud and fly ash contains a large Particles and particle size are not uniform, and cannot be used for fire extinguishing and cannot completely block the contact between air and coal; second, the foaming ratio is low, only about 30 times, which has a certain effect on preventing coal spontaneous combustion in underground coal mines, and cannot realize rapid fire extinguishing in coal mines The third is that this kind of foam generator should be provided with a barrier plate in the mixer, the manufacturing process is complicated, and it is easy to produce stagnation.

Patent No. 201110067937.7 "Foam generator for coal mine fire prevention and extinguishing" applied by Xi'an Xi'an Coal Mine Safety Ventilation and Fire Extinguishment Research Institute Co., Ltd. The mixing blade installed on the central shaft of the mixer is installed in the mixer, and the mixing blade is a spacer set The barrier long piece and the short piece are arranged on the central axis of the mixer. The flow holes are set on the long barrier piece, so that a non-linear flow channel is formed in the mixer, which prolongs the mixing time of the mixed slurry in the mixer, so that the mixed slurry can be fully mixed. well mixed. Its disadvantages are: compared with the patent No. 02148411.2, the barrier plate in the mixer is replaced with a central shaft with a long barrier piece and a short barrier piece. Low.

Contents of the invention

In view of the deficiencies of the prior art, the invention provides a device with simple structure, high foaming ratio, which can be used for preventing and controlling coal spontaneous combustion and rapid fire extinguishing.

The technical solution is an underground coal mine prevention and control of coal spontaneous combustion and rapid fire extinguishing device, which includes a cylindrical foam shell with two ends narrowed; The diameter of the raw liquid inlet and the compressed gas pipe is larger than the diameter of the foam raw liquid inlet; the other end of the foaming shell is connected with a foam output pipe; the axis inside the foaming shell is provided with a hollow shaft, and 6 to 8 sets of spirals are arranged on the hollow shaft at intervals. There are air outlets between the blades and the helical blades. The rotation direction of the above-mentioned helical blades and the axial angle of the hollow shaft are 45-60 degrees. The rotation direction of each group of helical blades is the same, and the rotation direction of the adjacent two groups is opposite; A foam net is installed at one end of the outlet of the foam shell.

In order to increase the foaming ratio, an auxiliary compressed air pipeline is provided on one side of the foam shell, and the auxiliary compressed air pipeline is connected with one end of the hollow shaft.

The mesh diameter of the foamed net is preferably 0.5 to 2 mm.

The distance between each set of helical blades is preferably the distance from the outer surface of the hollow shaft to the inner surface of the foam shell.

The above-mentioned helical blades are preferably three in each group, arranged in a triangle.

The working principle of the present invention is that, in the coal mine, the underground compressed gas supply pipeline is connected to the compressed gas pipeline and the auxiliary compressed gas pipeline of the device of the present invention, the compressed gas enters the inside of the foaming shell, and at the same time, a negative pressure is generated at the entrance of the foam stock solution, Inhale the foam stock solution and mix it initially. The mixed gas and liquid fluids are further mixed at the helical blade. Adjusting the rotation direction of the helical blade can provide different resistances to the mixture of compressed gas and foam stock solution. The blades with different rotation directions make the stirring effect further Strengthening and preliminary foaming, the amount of input compressed gas can be adjusted through the auxiliary compressed air pipeline, thereby changing the foaming ratio of the foam stock solution on the foaming net, and finally forming a fine and stable gel foam on the foaming net, which is discharged from the foam output pipe . By adjusting the entering amount of the auxiliary compressed gas and selecting the pore size of the foaming network, the foaming ratio of the gel foam can be 50-150 times.

Compared with the prior art, the present invention has the advantages of:

1. Since the diameter of the compressed gas pipeline is larger than the diameter of the foam stock solution inlet, negative pressure is generated at the foam stock solution inlet, and the mixture of compressed gas and foam stock solution is initially foamed in the foaming shell under the stirring of the spiral blade, which is used to prevent coal spontaneous combustion and achieve fire extinguishing.

2. Through the auxiliary compressed air pipeline, the auxiliary compressed gas is ejected from the air outlet on the hollow shaft, and the mixture is foamed twice, so that the foaming multiple can be rapidly increased to 50-150 times in a short time, achieving rapid Fire fighting purpose.

3. The fire-free device of the present invention does not require special power, and the material is not easy to block the pipe. It is reliable in use, compact in structure and convenient in maintenance, and is especially suitable for coal mine fire extinguishing operations.

Description of drawings

Fig. 1 is a structural front view of the present invention;

Fig. 2 is an enlarged view of section A-A in Fig. 1 .

In the figure: 1-compression air pipe, 2-foam stock solution inlet, 3-foaming shell, 4-foam output pipe, 5-hollow shaft, 6-air outlet, 7-spiral blade, 8-foaming net, 9- Auxiliary air piping.

Detailed ways

The technical scheme of the present invention will be further described below in conjunction with accompanying drawing and several embodiments:

Embodiment one

As shown in Figures 1 and 2, a coal mine fire prevention gel foam generating device includes a cylindrical foam shell 3 with two ends shrinking; one end of the foam shell 3 is connected with a compressed air pipeline 1, and the compressed air One side of the pipeline 1 is provided with a foam stock solution inlet 2, and the diameter of the compressed gas pipeline 1 is greater than the diameter of the foam stock solution inlet 2; the other end of the foam shell 3 is connected with a foam output pipeline 4; There is a hollow shaft 5 on which six sets of helical blades 7 are arranged at intervals, and the spacing distance is the distance from the outer surface of the hollow shaft 5 to the inner surface of the foam shell 3 . Air outlet holes 6 are provided between the helical blades 7. In Embodiment 1, the rotation direction of the helical blades 7 and the axial angle of the hollow shaft 5 are 45 degrees. The rotation direction of each group of helical blades 7 is the same. The direction of rotation of the blades 7 is opposite; an auxiliary compressed air pipeline 9 is provided on one side of the foaming shell 3, and the auxiliary compressed air pipeline 9 is connected to one end of the hollow shaft 5; The mesh diameter of the foaming net 8 is 0.5 mm.

The helical blades 7 in the embodiment are three in each group and arranged in a triangle.

The downhole compressed gas supply pipeline is connected to the compressed gas pipeline 1 and the auxiliary compressed gas pipeline 9 of the device of the present invention. The compressed gas enters the foaming shell 3 through the compressed gas pipeline 1, and through the adjustment of the auxiliary compressed gas pipeline 9, the compressed gas entering the casing 3 The flow ratio of the gas and the gel foam stock solution is 20:1, and the angle between the helical blade 7 and the axial direction of the hollow shaft 5 is 45 degrees, so that the passing gas and liquid are fully mixed, and after being stirred by 6 sets of helical blades 7, After passing through the foaming net 8 with a mesh diameter of 0.5 mm, 50 times the gel foam is formed.

Embodiment two

The second embodiment is basically the same as the first embodiment, except that the included angle between the direction of rotation of the helical blade 7 and the axial direction of the hollow shaft 5 is 60 degrees. When in use, adjust the auxiliary compressed air pipeline 9 so that the flow ratio of the compressed gas entering the foaming shell 3 and the gel foam stock solution is 25:1, and 80 times the gel foam is formed after foaming.

Embodiment three

Embodiment 3 is basically the same as Embodiment 2, except that eight sets of helical blades 7 are arranged at intervals on the hollow shaft 5, and the mesh diameter of the foam net is 2mm. When in use, adjust the auxiliary compressed air pipeline 9 so that the flow ratio of the compressed gas entering the foaming shell 3 and the gel foam stock solution is 30:1, and 120 times the gel foam is formed after foaming.

Embodiment four

The fourth embodiment is basically the same as the third embodiment, except that the included angle between the direction of rotation of the helical blade 7 and the axial direction of the hollow shaft 5 is 60 degrees. When in use, adjust the auxiliary compressed air pipeline 9 so that the flow ratio of the compressed gas entering the foaming shell 3 and the gel foam stock solution is 30:1, and 150 times the gel foam is formed after foaming.

Claims (4)

1. A coal mine prevention and control of coal spontaneous combustion and rapid fire extinguishing device is characterized in that it comprises a cylindrical foam shell with two ends shrinking; There is a foam stock solution inlet, and the diameter of the compressed air pipe is larger than that of the foam stock solution inlet; the other end of the foam shell is connected to a foam output pipe; the axis inside the foam shell is provided with a hollow shaft, and the hollow shaft is provided with 6-8 A group of helical blades, with air outlet holes between the helical blades, the angle between the direction of rotation of the above-mentioned helical blades and the axial direction of the hollow shaft is 45-60 degrees, the direction of rotation of each group of helical blades is the same, and the direction of rotation of two adjacent groups On the contrary; the foaming net is installed at the outlet end of the foaming shell; an auxiliary compressed air pipeline is arranged on one side of the foamed shell, and the auxiliary compressed air pipeline is connected with one end of the hollow shaft. 2. The underground coal mine prevention and control coal spontaneous combustion and rapid fire extinguishing device according to claim 1, characterized in that the mesh diameter of the foam net is 0.5-2mm. 3. The coal mine underground prevention and control coal spontaneous combustion and rapid fire extinguishing device according to claim 1, characterized in that, each group of the above-mentioned spiral blades is three pieces and arranged in a triangle. 4. The working method of preventing and controlling coal spontaneous combustion and rapid fire extinguishing device in coal mine underground as claimed in any one of claims 1-3, it is characterized in that, in coal mine underground, the underground compressed gas supply pipeline is connected in coal mine underground preventing and controlling coal spontaneous combustion and rapid fire extinguishing. On the compressed gas pipeline and auxiliary compressed gas pipeline of the fire extinguishing device, the compressed gas enters the inside of the foam shell, and at the same time, a negative pressure is generated at the entrance of the foam stock solution, and the foam stock solution is sucked in for preliminary mixing, and the mixed gas and liquid fluids are further mixed at the spiral blade. , adjust the direction of rotation of the helical blades to provide different resistance to the mixture of compressed gas and foam stock solution. Blades of different directions of rotation further enhance the stirring effect and initially foam. Adjust the amount of compressed gas input through the auxiliary compressed air pipeline to change the foam stock solution The foaming ratio is expanded on the foaming net, and fine and stable gel foam is finally formed on the foaming net, which is discharged from the foam output pipe; by adjusting the amount of auxiliary compressed gas entering and selecting the pore size of the foaming net, 50 to 150 times the foaming capacity can be obtained. The foaming multiple of the gel foam.