JP3137931B2 - Dust suppression device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust suppressor capable of suppressing dust by injecting air bubbles into dust generated when a solid or the like is broken.

[0002]

2. Description of the Related Art At construction demolition sites, recycled aggregate production sites, recycling sites, and the like, a large amount of dust is generated when solids are destroyed, which impairs workers' health and inconveniences nearby residents. I was hanging on. In order to prevent environmental pollution due to such dust pollution, conventionally, there are known a water spraying method in which generated dust is sprayed with water to suppress dust and a dust collecting method in which dust is directly sucked and collected. In addition to requiring large amounts of water, it consumes large amounts of water, and requires post-treatment of sewage mixed with dust and treatment to prevent sludge from scattering.
In some cases, water cannot be used. On the other hand, the dust collection method
There is a problem that the equipment becomes enormous, maintenance work is difficult, and the equipment cannot be easily changed.

[0003] Therefore, the present applicant uses air bubbles instead of water, that is, air bubbles are sprayed toward dust, or air bubbles are sprayed at a dust generation source, and the spray is covered with a bubble layer. Invented was a method and an apparatus for trapping and suppressing dust that would adhere to the liquid film of bubbles and fly into the air (Japanese Patent Application No. 8-353014). According to this, water consumption can be reduced to 1/10,
The cost can be greatly reduced and the structure of the device is simple.

[0004]

The generation of air bubbles is determined by adjusting the mixing ratio of the chemical used, water and air, and the respective pressures. It is difficult to always stabilize and generate bubbles. Therefore, there is only one set of manifolds to which a plurality of nozzles for spraying or spraying air bubbles are attached, or when two or more sets of manifolds are used at all times, if all sets are used, chemicals, water, and air are used. There is no problem because there is no change in the flow rate and pressure, but usually, as shown in FIG. 1 described below, one set of manifolds is used when pulverized by the secondary crusher and when crushed by the tertiary crusher Therefore, for example, if the degree of pulverization by the secondary crusher is large, even if two sets of manifolds are used at the same time and bubbles are injected at two locations, the subsequent tertiary crusher side manifold becomes unnecessary and the injection may be stopped.

In this case, since one source of chemical, water, and air is used to produce air bubbles sent to the nozzles of the two sets of manifolds, the injection of one set of manifolds (tertiary crusher side) is performed. When stopped, the supply of chemicals and water concentrates on the other set (secondary crusher side), and pressure is applied.
There is no problem on the set side, and there is a problem that the injection of bubbles on the other set side is not stable. According to this, the size of the air bubbles becomes uneven, and the dust may not be sufficiently suppressed. Here, an example in which two sets of manifolds are used has been described. However, the same applies to a case where a plurality of manifolds are used. There is no problem in the case where there are two or more sets of manifolds and each manifold has an independent source of chemicals, water and air, but such a case is not usually considered from the viewpoint of cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dust suppressing device capable of stably generating air bubbles and suppressing dust even when an injection point is partially interrupted.

[0007]

According to a first aspect of the present invention, there is provided a dust suppression device, comprising mixing a supplied chemical solution containing a surfactant with water at the same pressure to form a mixed solution. A mixed liquid manufacturing apparatus (1) to be manufactured; a foaming device (2) for generating a bubble by mixing the mixed solution and compressed air; a liquid sending means (3) for sending the manufactured mixed solution to the foaming device (2); Air supply means (4) for sending compressed air to the foaming device (2); chemical liquid pressure for detecting the pressure of the chemical liquid to be sent, which is provided in the mixed liquid production apparatus (1) before the chemical liquid and water are mixed. A sensor (5); an air pressure sensor (6) provided in the air supply means (4) for detecting an air pressure to be sent; at least two or more sets of manifolds (8, 8) equipped with a plurality of ejection nozzles (7). 9); Connect the foamer (2) to each manifold (8, 9) and generate Supply means (10) for sending the generated bubbles to the jet nozzle (7); the chemical liquid control valve (11) and the water control valve (12) provided in the mixed liquid production apparatus (1) are driven forward / reversely. Open / close drive means (M
1); and the value (PC) of the chemical pressure sensor (5)
Is compared with the value (PA) of the pressure sensor for air (6), and when the pressure (PC) of the chemical solution is larger than the pressure (PA) of the air by the set value (K), the driving means (M1) is driven in reverse. The control valve for chemical solution (11) and the control valve for water (12) are closed. Conversely, when the pressure (PC) of the chemical solution becomes smaller than the pressure (PA) of air by the set value (K), the drive means (M1) is turned off. Rotate forward to control chemical liquid control valve (11) and water control valve (12)
, And a control means (13) for keeping the pressure of the chemical solution and the water relative to the air pressure constant.

Further, according to the present invention, the air supply means (4) is opened / closed by driving the air control valve (24) forward / reversely.
The air valve driving means (M2) for closing is further provided, and the control means (13) compares the value (PC) of the chemical liquid pressure sensor (5) with the value (PA) of the air pressure sensor (6), When the pressure (PC) of the chemical liquid becomes larger than the pressure (PA) of the air by the set value (K), the driving means (M1) is driven in reverse to open the chemical liquid control valve (11) and the water control valve (12). Close and drive the air valve drive means (M2) forward to open the air control valve (24), and conversely, the pressure of the chemical (PC)
Is smaller than the air pressure (PA) by the set value (K), the driving means (M1) is driven to rotate in the normal direction, and the chemical liquid control valve (1) is driven.
1) and the water control valve (12) is opened, and the air valve drive means (M2) is driven in reverse to drive the air control valve (24).
2. The dust suppression device according to claim 1, wherein the pressure of the chemical and the water with respect to the air pressure are kept constant by closing the air pressure.

Further, according to a third aspect of the present invention, the control means (13) comprises at least two or more sets of manifolds (8, 8).
When it is detected that the injection of air bubbles is stopped or interrupted from the plurality of jet nozzles (7) of one set of manifolds (9) out of 9), the value (PC) of the pressure sensor for chemical liquid (5) is detected.
3 is compared with a value (PA) of a pressure sensor for air, and control for keeping the pressure of the chemical solution and water relative to the air pressure based on the result is performed, and the dust suppression device according to claim 1 or 2, wherein is there.

[0010] The invention according to claim 4 is characterized in that the chemical solution containing a surfactant is an α-olefin sulfonate (AOS) belonging to an anionic surfactant. A dust suppression device according to any one of the above.

The symbols in parentheses above correspond to the symbols described in the drawings and the embodiments of the invention described later.

According to the first aspect of the invention, the control means compares the pressure value of the chemical supplied to the foaming device with the same pressure as that of water and mixed with the pressure value of the air supplied to the same foaming device. And
When the pressure of the chemical becomes larger than the air pressure by the set value,
The driving means is reversely driven to close the chemical liquid control valve and the water control valve. As a result, the flow rates of the supplied chemical liquid and water decrease, and the pressure value detected by the chemical liquid pressure sensor decreases. Conversely, when the pressure of the chemical becomes lower than the pressure of the air by the set value, the driving means is driven to rotate forward to open the chemical control valve and the water control valve. As a result, the flow rates of the supplied chemical liquid and water increase, and the pressure value detected by the chemical liquid pressure sensor increases. In this way, control is performed to keep the pressure of the chemical solution and water constant with respect to the air pressure, so that the injection point is partially interrupted, and even if there is a temporary fluctuation in the flow rate and pressure of the chemical solution, water, and air pressure, automatic control is performed. The air bubbles can be stably ejected from the nozzles of the manifold. Therefore, dust can be continuously suppressed.

According to the second aspect of the present invention, the control means controls the air to be opened / closed by driving the pneumatic control valve forward / reverse in addition to bringing the pressure of the chemical solution and water close to the air pressure. Since the pneumatic pressure is made closer to the pressure of the chemical and water by using the valve driving means, the time for controlling the pressure of the chemical and water with respect to the air pressure to be constant is reduced.

Further, according to the third aspect of the present invention, in addition to the functions and effects of the first or second aspect, the control means further comprises:
When it is detected that the injection of air bubbles has been stopped or interrupted from a plurality of ejection nozzles of one set of manifolds of at least two or more sets of manifolds,
Only when the fluctuation of the flow rate and the pressure of the water and the air pressure is expected to be large, the pressure of the chemical solution and the water with respect to the air pressure is controlled to be constant, so that it is efficient.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an example in which a dust suppression device according to an embodiment of the present invention is applied to a site, and FIG.
Is a block diagram showing a configuration outline of a control system of the dust suppression device according to the embodiment of the present invention, and FIG. 3 is a configuration diagram showing connection between each manifold and the mixed liquid production device.

A dust suppression device according to an embodiment of the present invention comprises:
A mixed liquid manufacturing apparatus for mixing a liquid chemical mainly containing a surfactant and water with the same pressure to produce a mixed liquid 1, a foaming device 2 for mixing the mixed liquid and compressed air to generate air bubbles 2, and manufacturing The mixed liquid supply pipe 3 as a liquid sending means for sending the mixed liquid to the foaming device 2, the air pressure supply pipe 4 as an air sending means for sending the compressed air to the foaming device 2, and the chemical and water of the mixed liquid manufacturing apparatus 1 are mixed. A pressure sensor for chemical solution, which is provided before the position to be sent, for detecting the pressure of the chemical solution to be sent, a pressure sensor for air, provided for the air pressure supply pipe 4 for detecting the air pressure to be sent, and a plurality of ejection nozzles 7. At least two sets of the attached manifolds 8, 9; the foaming device 2 and each of the manifolds 8, 9; a bubble supply pipe 10 as a bubble supply means for sending generated bubbles to a jet nozzle 7; For chemicals provided in device 1 A motor M1 as a driving means for opening / closing the gates of the node valve 11 and the water control valve 12 by forward / reverse rotation, and a central control functioning as a control means for keeping the pressure of the supplied chemical solution and water constant. An apparatus 13 is provided.

The water sent to the mixed liquid producing apparatus 1 is supplied from a water tank or a water source by a pump 15, and the flow rate and pressure are detected by a flow meter 16 and a water pressure sensor 17. Is used to adjust the flow rate and pressure. The chemical is also pumped from the tank via the filter 18 by the pump 19, the flow rate and the pressure are detected by the flow meter 20 and the chemical pressure sensor 5, and the flow rate and the pressure are adjusted by opening and closing the chemical control valve 11. You. The opening and closing of the gate of the chemical liquid control valve 11 and the opening and closing of the gate of the water control valve 12 are performed simultaneously by one motor M1, and the chemical and water are mixed at the same pressure. Is equal to the value PC of the chemical liquid pressure sensor 5. Note that two motors may be prepared. In addition, the mixed liquid producing apparatus 1 includes a compressor 21.
Is supplied through the filter 22,
The flow rate and the pressure are detected by the flow meter 23 and the air pressure sensor 6, and the flow rate and the pressure are adjusted by opening and closing the gate of the air control valve 24 by driving the motor M2.

The foamer 2 generates bubbles by repeating the process of turbulently agitating the mixed liquid and compressed air with a cylindrical filter and then rectifying the mixture a plurality of times (usually two to three times). I have. One of the foaming devices 2 may be shared by the two manifolds 8 and 9 (FIG. 1), or the foaming device 2 may be provided for each manifold (FIG. 2). The central control device 13 controls the entire dust suppression device according to the embodiment of the present invention, and plays a central role in the control.
It has various storage units including a PU, a ROM, and a RAM. Also, a panel setting device and a handy setting device are connected so that setting values and the like can be input from outside.

When air bubbles are sprayed from the nozzle 7 onto the dust floating in the air, the dust is covered with a bubble layer and adheres to the liquid film of the bubbles. That is, the bubbles replenish moisture to the dust surface,
The components of the chemical solution remaining on the surface cause the dust to be adsorbed to each other and fall at an early stage, thereby preventing the scattering of the dust. The chemical solution containing a surfactant used here is an α-olefin sulfonate (AOS) belonging to an anionic surfactant and used as a dust suppressant as a dust suppressant (Act on the Examination of Chemical Substances and Regulation of Manufacturing, etc.) ) Is a substance approved in) that, when dissolved in a liquid, significantly lowers the surface tension of the liquid. Two liquids that do not mix with each other, such as water and oil, are combined with one another. When the agent is contained, dust is wetted to easily adhere to water droplets, and soap is widely used in industrial fields such as detergents, emulsifiers, and solvents as typical examples. In order to extend the residual effect, a chemical solution having a coagulation action may be added. According to this, it is effective also in the sedimentation of the muddy water generated by the crushed sand washing.

Among the above components, the mixed liquid production apparatus 1
Various pressure sensors 5, 6, 17, various control valves 11, 1
2, 24, various flow meters 16, 20, 23, pump 15,
In the present embodiment, the filter 19, the filters 18, 22, the central control device 13, and the motors M1, M2 are incorporated as a foam control device 100. Other, foam control device 1
A solenoid valve 25 and a solenoid valve 26 for shutting down are provided on the side where the mixed liquid of 00 and the compressed air are output. In addition, the mixed liquid production apparatus 1 includes various control valves 11, 1
2, 24, controllers 28, 29, 30 connected to the various flow meters 16, 20, 23, respectively, and the controller 31 connected between the pumps 15, 19 and the central controller 13.
32. As described above, the respective components are incorporated into the foam control device 100 and are integrated, but may be configured separately. It is also possible to divide and arrange them on the construction machine or to mount them integrally.

The mixed liquid supply pipe 3 and the pneumatic supply pipe 4
It consists of a metal steel tube or a hard rubber tube. The nozzles 7 attached to the manifolds 8 and 9 can select the diameter of the injection port. On-off valves 33, 34, 34 are provided between each of the manifolds 8, 9 and the bubble supply pipe 10.
35 and 36 are provided.

Such a dust suppressing device is, for example, shown in FIG.
Applied on site as shown in That is, one of the two manifolds 8, 9 is
Is placed on the inlet side where the solid material crushed by the primary crusher is carried by the conveyor and crushed by the secondary crusher,
The other manifold 9 is arranged on the inlet side where the solids crushed by the secondary crusher are transported and then crushed by the tertiary crusher.

Next, the contents of the pressure control processing of the central control unit 13 will be described with reference to the flowchart shown in FIG. When bubbles are ejected from both the manifolds 8 and 9, there is no problem because there is no change in the flow rate and pressure of the chemical, water, and air. However, when the injection of the foam from one of the manifolds is stopped, the chemical, water, and the like are stopped. Since the flow rate and pressure of the air fluctuate and the size of the foam injected from the other moving manifold becomes uneven and the dust suppression processing becomes unstable, the injection of the foam from one manifold 9 is stopped or interrupted. (Step 1: Hereinafter, the word “step” is omitted in parentheses), the following processing is executed.

The case where the injection of the foam from the manifold 9 is stopped or interrupted means that the on-off valves 35 and 36 are closed, for example, when the degree of pulverization by the secondary crusher is large and the tertiary crusher is unnecessary. Done by Here, the central control device 13 includes an on-off valve 35,
By detecting the operation from opening to closing of 36, it is determined that the injection of the foam from the manifold 9 has been stopped or interrupted, but instead, for example, by pressing another switch by an operator or the like, Is also good.

When the central controller 13 detects that the injection from the manifold 9 is stopped or interrupted (1),
The flag F is set to 0 (2), and each pressure sensor 5,
The values PC, PA and PW of 6, 17 are read (3). Since the chemical and the water are mixed at the same pressure to produce a mixed liquid, the value PC of the chemical pressure sensor 5 and the value PW of the water pressure sensor 17 are equal. Next, the central controller 13
Compares the value PC of the chemical liquid pressure sensor 5 with the value PA of the air pressure sensor 6 and determines whether or not the absolute value of the value obtained by subtracting the value PA from the value PC is equal to or less than the set value K ( 4). When the value becomes larger than the set value K, the flag F is set to 1 (5), and it is determined which of the value PC and the value PA is larger (6). The set value K is input from the panel setting device described above. For example, if the set value K is set to 0, an allowable error for changing the value PC of the chemical pressure sensor 5 to the value PA of the air pressure sensor 6 is eliminated. Will be.

If the value PC is larger, the central controller 13 drives the motor M1 in the reverse direction to move both the gate of the chemical liquid control valve 11 and the gate of the water control valve 12 in a direction to close (7). . Thereby, the flow rates of the supplied chemical solution and water decrease, and the pressure value PC detected by the chemical pressure sensor 5 decreases (the pressure value PW detected by the water pressure sensor 17 also decreases similarly). ). Conversely, if the value PC is smaller in step 6, the central controller 13
The motor M1 is driven to rotate forward, and both the gate of the chemical liquid control valve 11 and the gate of the water control valve 12 are moved in the opening direction (8). As a result, the flow rates of the supplied chemical solution and water increase, and the pressure value PC detected by the chemical pressure sensor 5 increases (the pressure value P detected by the water pressure sensor 17).
W also increases similarly). Then, returning to step 3, step 3-4-5-6-7 (or 8) -3-.
・ Repeat the process.

Thereafter, in step 4, when the absolute value of the value obtained by subtracting the value PA of the air pressure sensor 6 from the value PC of the chemical pressure sensor 5 becomes equal to or smaller than the set value K, the central control unit 13 sets the flag F to It is determined whether or not the motor M1 is set to 1 (9). If the flag F is 0, the motor M1 is not in the driving state and the routine returns. The drive of any of the reverse rotations is stopped, and the opening of the gate of the chemical liquid control valve 11 and the gate of the water control valve 12 are held at that position (1).
0). As a result, the pressure of the chemical solution and the water with respect to the air pressure can be controlled to be constant, so that bubbles can be stably generated even when the injection point is partially interrupted, and dust can be suppressed.

When controlling the pressure of the chemical and the water with respect to the air pressure to a constant value, the value of the pressure sensor 5 for the chemical is measured by using a motor M2 that opens / closes the air control valve 24 by rotating the air forward / reverse. The PC is compared with the value PA of the air pressure sensor 6, and when the pressure PC of the chemical solution is larger than the pressure PA of the air by the set value K, the motor M1 is driven in reverse in step 7 to control the control valve 11 for the chemical solution and the water. When the control valve 12 is closed and the motor M2 is driven forward to open the air control valve 24, conversely, when the pressure PC of the chemical solution is smaller than the pressure PA of the air by the set value K, the motor M1 is driven forward in step 8. Then, the control valve for chemical liquid 11 and the control valve for water 12 may be opened, and the motor M2 may be driven in reverse to close the control valve for air 24. According to this, in addition to bringing the pressure of the chemical solution and water close to the air pressure, the air pressure also approaches the pressure of the chemical solution and water, so that the time for controlling the pressure of the chemical solution and water with respect to the air pressure to be constant is reduced. .

In this embodiment, the central control unit 13
Detects that the injection of air bubbles from the manifold 9 is stopped or interrupted in step 1 and controls the pressure to be efficiently constant only at that time. In addition to this, or in addition to this, Step 2 detects that the manifold 9 in which the injection of the bubble has been interrupted has restarted its injection by detecting the operation of the on-off valves 35 and 36 from the closing to the opening.
The following processing may be performed.

The manifolds 8 and 9 to which the plurality of nozzles 7 are attached may be frame-shaped manifolds 50 as shown in FIG. 5 instead of linear ones.

[0031]

As described above, according to the first aspect of the present invention, the pressure value of the chemical solution is compared with the pressure value of the air, and the driving means is driven forward or reverse to adjust the chemical solution. Opening and closing the valve and the water control valve to control the pressure of the chemical and water relative to the air pressure is performed,
The injection point is partially interrupted, and even if there is a temporary change in the flow rate and pressure of the chemical, water, and air pressure, it is automatically corrected.
Air bubbles can be stably emitted from the nozzles of the manifold. Therefore, dust can be continuously suppressed.

According to the second aspect of the present invention, the control means controls the air to be opened / closed by driving the pneumatic control valve forward / reversely in addition to bringing the pressure of the chemical and water close to the air pressure. Since the pneumatic pressure is made closer to the pressure of the chemical and water by using the valve driving means, the time for controlling the pressure of the chemical and water with respect to the air pressure to be constant is reduced.

Further, according to the third aspect of the present invention, in addition to the functions and effects of the first or second aspect, the control means further comprises:
When it is detected that the injection of air bubbles has been stopped or interrupted from a plurality of ejection nozzles of one set of manifolds of at least two or more sets of manifolds,
Only when the fluctuation of the flow rate and the pressure of the water and the air pressure is expected to be large, the pressure of the chemical solution and the water with respect to the air pressure is controlled to be constant, so that it is efficient.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example in which a dust suppression device according to an embodiment of the present invention is applied to a site.

FIG. 2 is a block diagram illustrating a configuration outline of a control system of the dust suppression device according to the embodiment of the present invention.

FIG. 3 is a configuration diagram showing a connection between each manifold and a mixed liquid manufacturing apparatus.

FIG. 4 is a flowchart showing the contents of a pressure control process of the central control device.

FIG. 5 is a perspective view showing another embodiment of the manifold.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mixed liquid production apparatus 2 foamer 3 mixed liquid supply pipe 4 air pressure supply pipe 5 chemical liquid pressure sensor 6 air pressure sensor 7 nozzle 8,9 manifold 10 bubble supply pipe 11 chemical liquid control valve 12 water control valve 13 central control Apparatus 15 Pump 17 Water pressure sensor 19 Pump 21 Compressor 24 Air control valve 33, 34, 35, 36 On-off valve 50 Manifold 51 Nozzle 100 Foaming control device M1 motor M2 motor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenji Kaneshiro 2-3-24 Yano Shinmachi, Aki-ku, Hiroshima City Mentec Co., Ltd. (56) References JP-A-2-300500 (JP, A) JP-A-Hei 9-47682 (JP, A) JP-A-5-96213 (JP, A) JP-A-6-277573 (JP, A) JP-A-10-169218 (JP, A) JP-B-51-35024 (JP, A) B2) Jiko 2-5896 (JP, Y2) Utility model registration 2548547 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05B 7/26 B05C 11/10 B01F 3/04 B02C 23/00 E04G 23/08

Claims (4)

(57) [Claims] 1. A mixed liquid producing apparatus for producing a mixed liquid by mixing a supplied chemical liquid containing a surfactant and water at the same pressure; a foaming device for mixing the mixed liquid and compressed air to generate air bubbles; Liquid sending means for sending the produced mixed solution to the foaming device; air sending means for sending compressed air to the foaming device; of the sent chemical solution provided in the mixed solution manufacturing apparatus before the chemical solution and water are mixed. A pressure sensor for a chemical solution for detecting pressure; a pressure sensor for air provided in an air supply means for detecting an air pressure to be sent; at least two or more sets of manifolds to which a plurality of ejection nozzles are attached; And a bubble supply means for sending generated bubbles to a nozzle for jetting; a drive means for opening / closing the control valve for chemical liquid and the control valve for water provided in the mixed liquid production apparatus by forward / reverse rotation; And the pressure sensor for chemicals The value of the sensor is compared with the value of the air pressure sensor, and when the pressure of the chemical solution is larger than the pressure of the air by a set value, the driving means is driven in reverse to close the chemical liquid control valve and the water control valve, and When the pressure of the chemical solution is smaller than the pressure of the air by a set value, the drive means is driven to rotate forward to open the control valve for the chemical solution and the control valve for the water so as to make the pressure of the chemical solution and water constant with respect to the air pressure; A dust suppression device comprising: 2. The air supply means further comprises air valve drive means for opening / closing the air control valve by rotating the air control valve forward / reversely, and the control means uses the value of the chemical liquid pressure sensor as the air pressure sensor. When the pressure of the chemical is greater than the pressure of the air by the set value, the driving means is driven in reverse to close the chemical liquid control valve and the water control valve, and the air valve driving means is driven in normal rotation. On the contrary, when the pressure of the chemical solution is smaller than the air pressure by the set value, the driving means is driven forward to open the control valve for the chemical solution and the control valve for the water and to drive the air valve. 2. The dust suppression device according to claim 1, wherein the means is reversely driven to close the air control valve so that the pressure of the chemical and the water with respect to the air pressure is constant. 3. When the control means detects that the injection of bubbles from a plurality of ejection nozzles of one set of at least two or more sets of manifolds is stopped or interrupted, the control means detects the pressure of the chemical liquid pressure sensor. 3. The dust suppression device according to claim 1, wherein the value is compared with a value of an air pressure sensor, and control is performed to make the pressure of the chemical solution and water constant with respect to the air pressure based on the result. 4. 4. The chemical solution containing a surfactant is an α-olefin sulfonate (AO) belonging to an anionic surfactant.
The dust suppression device according to any one of claims 1 to 3, wherein S).