Charge detector

Abstract

To detect the charging polarity of a particulate air-fuel mixture with high accuracy in order to spray charged water particles having a charging polarity opposite to the charging polarity of the particulate air-fuel mixture generated in a spraying object region.SOLUTION: The charge detector 80 includes the conductive cylindrical electrodes 95 that are formed in a cylindrical shape having a hollow portion and allow the particulate mixture to pass from one end side to the other end side of the hollow portion, the Faraday cage 96 that is electrically insulated from the cylindrical electrodes 95 and has the conductive outer cylindrical body side 98a and side 98b that cover the outer circumferences of the cylindrical electrodes 95 and are grounded, and the charge detection unit 105 that converts induced charges having the same polarity as the charging polarity of the particulate mixture induced to the outer circumferences of the cylindrical electrodes 95 by the charges of the particulate mixture into a voltage signal and outputs the voltage signal. A determination part 114 for determining the electrification polarity of the particulate mixture based on the voltage signal outputted from the charge detection part 105 is provided, and the length of the eaves part exceeding one end side and the other end side of the cylindrical electrode 9 in the one end side and the other end side of the outer cylindrical bodies 98a, 98b is set to be twice or more of the inner diameter of the cylindrical electrode 9.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a charged water particle spraying system that extinguishes a fire by spraying charged water particles from the tip of the ladder of a ladder fire truck or the like to a target area such as a building where a fire has broken out. [Background technology]

[0002] Conventionally, a charged water particle spraying system has been known that sprays electrically charged water particles onto a target area such as a building where a fire has broken out to extinguish the fire. This system is expected to be able to extinguish fires efficiently with a small amount of water and reduce water damage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-106405 [Patent Document 2] Japanese Patent Application Publication No. 2018-183712 [Patent Document 3] JP 2018-16965 A [Patent Document 4] Japanese Patent Application Publication No. 11-295433 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional charged water particle spraying systems, charged water particles sprayed from a charged spray head are sprayed onto a target area where a fire has occurred to suppress and extinguish the fire and to eliminate smoke generated in the target area. For example, when negatively charged charged water particles are sprayed from the charged spray head, if the particulate mixture containing smoke particles and the like generated in the target area is positively charged, it is believed that the particulates (smoke particles) contained in the particulate mixture are attracted to and captured by the charged water particles due to electrostatic force, thereby more effectively eliminating smoke. Also, when positively charged charged water particles are sprayed from the charged spray head, if the particulate mixture is negatively charged, it is believed that the particulates (smoke particles) contained in the particulate mixture are attracted to and captured by the charged water particles due to electrostatic force, thereby more effectively eliminating smoke.

[0005] However, whether the particulate mixture generated in the target spray area is negatively or positively charged varies depending on the type of combustible material and the characteristics of the fire, and sufficient smoke suppression performance may not be achieved unless the particulate mixture is charged with the opposite polarity to the charged water particles.

[0006] The present invention aims to provide a charge detector for use in a charged water particle spraying system that can detect the charge polarity of a particulate mixture with high accuracy in order to spray charged water particles with a charge polarity opposite to that of the particulate mixture generated in the spraying target area. [Means for solving the problem]

[0007] (Charged detector) The present invention provides a charge detector for detecting the charge polarity of a particulate mixture, comprising: a conductive cylindrical electrode formed in a cylindrical shape having a hollow portion and allowing the particulate gas mixture to pass from one end side to the other end side of the hollow portion; a Faraday cage having a conductive outer cylinder that is electrically insulated from the cylindrical electrode, covers the outer periphery of the cylindrical electrode, and is grounded; a charge detection unit that converts induced charges of the same polarity as the charged polarity of the particulate mixture, which are attracted to the outer periphery of the cylindrical electrode by the charges of the particulate mixture, into a voltage signal and outputs the voltage signal; a determination unit that determines the charge polarity of the particulate mixture based on a voltage signal output from the charge detection unit; Equipped with The Faraday cage is characterized in that the length of the eaves portion of one end and the other end of the outer cylindrical body that constitutes the Faraday cage and is installed to cover the outer periphery of the cylindrical electrode, which extends beyond one end and the other end of the cylindrical electrode, is more than twice the inner diameter of the cylindrical electrode.

[0008] (Determining charge polarity based on integration results) The determination unit determines the charge polarity of the particulate mixture based on the integration result of the voltage signal output from the charge detection unit.

[0009] (Determining charge polarity based on time change of integral value) The judgment unit judges the charging polarity of the particulate mixture to be negative if the integral value, which is the integration result, decreases over time, and judges the charging polarity of the particulate mixture to be positive if the integral value increases over time. [Effects of the Invention]

[0010] (Effect of the charged water particle spraying system) According to the charged water particle spraying system of the present invention, when spraying charged water particles sprayed from a plurality of charged spray heads onto a target area, a suction device sucks the particulate gas mixture flow generated in the target area towards a charge detector, and the charge detector detects the charge polarity of the mixed particulate gas flow. The control unit switches and controls the charge polarity of the charged water particles to be sprayed onto the target area based on the charge polarity of the particulate gas mixture detected by the charge detector. Specifically, the charge detector is formed in a cylindrical shape with a hollow section, and is provided with a conductive cylindrical electrode that passes the particulate gas mixture from one end to the other end of the hollow section, and a Faraday cage is provided with a conductive outer cylinder that is electrically insulated, covers the outer periphery of the cylindrical electrode, and is grounded, and the charge detector detects the charge polarity of the particulate gas mixture. The induced charge, which is of the same polarity as the charge polarity of the particulate mixture attracted to the outer periphery of the cylindrical electrode by the charge, is converted into a voltage signal by the charge detection unit and output, and the determination unit determines the charge polarity of the particulate mixture based on the voltage signal output from the charge detection unit.Since the cylindrical electrode is provided inside the Faraday cage, the charge polarity of the particulate mixture generated in the target spray area due to a fire can be detected with high accuracy without being affected by electrical disturbance factors (noise).For example, by spraying charged water particles charged with a polarity opposite to the charge polarity of the particulate mixture detected by the charge detector into the target spray area, the particulates contained in the particulate mixture can be collected, captured and removed by electrostatic force, resulting in high smoke suppression performance.

[0011] (Effect of the length of the eaves of the outer cylinder of the Faraday cage) In addition, by making the length of the eaves portion that extends beyond one end and the other end of the cylindrical electrode at one end and the other end of the outer cylinder that constitutes the Faraday cage installed to cover the outer periphery of the cylindrical electrode more than twice the inner diameter of the cylindrical electrode, even if there are openings at one end and the other end of the eaves portion that constitutes the Faraday cage, which are inlet and outlet openings that allow the particulate mixture to pass into the hollow portion of the cylindrical electrode, the distance of the eaves portion from the inlet and outlet openings to the cylindrical electrode is sufficient, so the effect of electrical disturbance factors on the cylindrical electrode is suppressed or prevented, and high detection accuracy is obtained in detecting the charging polarity of the particulate mixture.

[0012] (Effect of determining charge polarity based on integration results) In addition, the judgment unit judges the charge polarity of the particulate mixture based on the integration result of the voltage signal output from the charge detection unit. Specifically, the judgment unit judges the charge polarity of the particulate mixture to be negative if the integral value, which is the integration result, decreases over time, and judges the charge polarity of the particulate mixture to be positive if the integral value increases over time.As a result, different characteristics arising from differences in the charge polarity of the particulate mixture can be obtained from the integration result of the voltage signal, making it possible to detect the charge polarity of the particulate mixture stably with high accuracy.

[0013] (Effect of fire engines equipped with fire and smoke suppression systems) Furthermore, at least the charged spray head, charge detector, and suction device of the fire and smoke extinguishing system are installed at the tip of the ladder of a ladder fire truck, the aerial work platform of a high-altitude work fire truck, or the boom tip of a boom-equipped fire truck, so that even in the case of a fire at a high altitude, for example, on the second floor or higher of a building, the ladder tip of the ladder fire truck, the aerial work platform of a high-altitude work fire truck, or the boom tip of a boom-equipped fire truck can be placed close to an exterior wall opening such as a window, and the charged polarity of the particulate air-fuel mixture released from there can be detected with high accuracy, and charged water particles of the opposite polarity can be sprayed to ensure high smoke extinguishing performance. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an explanatory diagram showing an embodiment of a charged water particle spraying system of the present invention. [Figure 2] 2 is an explanatory diagram showing an embodiment of the charged water particle emitting portion of FIG. 1. FIG. [Figure 3] 3 is an explanatory diagram showing an embodiment of a charged spray head provided in the charged water particle discharge unit of FIG. 2. FIG. [Figure 4] 2 is an explanatory diagram showing an embodiment of the high-voltage power supply unit in FIG. 1 together with an electrostatic spray head. FIG. [Figure 5] 2 is an explanatory diagram showing an embodiment of the fire extinguishing agent supply unit in FIG. 1 together with an electrostatic spray head. FIG. [Figure 6] FIG. 2 is an explanatory diagram showing the suction device of FIG. [Figure 7] FIG. 2 is an explanatory diagram showing an embodiment of the charge detector of FIG. [Figure 8] 5A and 5B are explanatory diagrams showing a charge detection operation by a charge detection unit of the charge detector; [Figure 9] FIG. 1 is an explanatory diagram showing a firefighting activity using a ladder fire engine equipped with the charged water particle spraying system of the present invention. [Figure 10] 4 is a flowchart showing the control operation of the charged water particle spraying system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a system for spraying charged water particles according to the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment.

[0016] [Basic concept of the embodiment] First, the basic concept of the embodiment will be described. The embodiment generally relates to a charged water particle spraying system that sprays charged water particles to a target area, and is installed on a mobile object such as a fire engine, for example.

[0017] Here, the "charged water particle spraying system" is a system that includes multiple charged spray heads, a charge detector, a suction device, and a control unit, and includes the concepts of charged water particle spraying equipment and charged water particle spraying tools for constructing a charged water particle spraying system. Furthermore, the "target spraying area" is a concept that includes sources of smoke, fire, or the locations or spaces where these exist, as well as the areas where smoke, etc., diffuse.

[0018] The "charged spray head" is a device that sprays charged water particles to spray the charged water particles onto a target area, and in this embodiment, multiple charged spray heads are provided.

[0019] Furthermore, "charged water particles" are electrically charged water particles contained in the spray flow of fire extinguishing agent sprayed from an electrically charged spray head, and are water particles charged using an induction charging method in which the water particles pass through a high electric field generated by a predetermined high voltage applied to the electrically charged spray head from a high-voltage power supply.

[0020] Furthermore, "spraying charged water particles onto a target area" means that the method of spraying is arbitrary as long as the charged water particles sprayed from the charged spray head can be moved to the target area and sprayed there. For example, an airflow can be generated toward the target area, and a charged water particle airflow containing the charged water particles sprayed from the charged spray head can be released into the airflow, thereby moving the charged water particles to the target area and spraying them there; alternatively, spraying charged water particles from the charged spray head can be sprayed onto the target area.

[0021] The "charge detector" detects the charge polarity of the particulate mixture generated in the target spray area. Here, the "particulate mixture" refers to a gas containing particulates, including smoke particles and monodisperse particles generated by a fire, and combustion-produced gases such as carbon dioxide and carbon monoxide. The "charge of the particulate mixture" refers to the "charge of particles contained in the particulate mixture," and the "charge of the particulate mixture" refers to the "charge of particles contained in the particulate mixture." The "particulate mixture generated in the target area" refers to the "particulate mixture generated in the target area," and is a concept that includes "generating from a smoke source or fire source present in the target area," and therefore "being included in the location, spatial area, etc. of the smoke source or fire source, or the smoke diffusion area."

[0022] The configuration and function of the charge detector are arbitrary, but may be, for example, composed of a cylindrical electrode, a Faraday cage, a charge detection unit, and a determination unit. Here, the "cylindrical electrode" refers to a conductive electrode member formed in a cylindrical shape with a hollow portion and allowing the particulate gas mixture to pass from one end to the other end of the hollow portion. Also, the term "cylindrical" refers to any shape as long as it has a hollow portion and allows the particulate gas mixture to pass from one end to the other end of the hollow portion.

[0023] Furthermore, a "Faraday cage" is a device that has a conductive outer cylindrical body that is electrically insulated from a cylindrical electrode, covers the outer periphery of the cylindrical electrode, and is grounded, and that suppresses or prevents the effects of electrical disturbance factors on the cylindrical electrode.

[0024] In addition, a "Faraday cage" is a Faraday cage that is installed to cover the outer periphery of a cylindrical electrode. The length of the eaves portion that extends beyond one end and the other end of the cylindrical electrode on one end and the other end of the external cylindrical body is more than twice the inner diameter of the cylindrical electrode, thereby suppressing or preventing the influence of electrical disturbance factors on the cylindrical electrode from the openings at the entrance at one end and the exit at the other end of the external cylindrical body.

[0025] The "charge detector" converts the induced charge, which is attracted to the outer periphery of the cylindrical electrode by the charge of the particulate mixture and has the same polarity as the charged polarity of the particulate mixture, into a voltage signal and outputs it.

[0026] Furthermore, the "determination unit" detects the charge polarity of the particulate mixture by determining the charge polarity of the particulate mixture based on the voltage signal output from the charge detection unit, and outputs the determined charge polarity of the particulate mixture to the control unit, for example, determining the charge polarity of the particulate mixture based on the integration result of the voltage signal output from the charge detection unit. Specifically, the "determination unit" determines the charge polarity of the particulate mixture to be negative if the integral value, which is the integration result, decreases over time, and determines the charge polarity of the particulate mixture to be positive if the integral value increases over time.

[0027] The "suction device" is a device that sucks the particulate mixture from the spray target area toward the charge detector.

[0028] In addition, the "control unit" controls the switching of the charge polarity of the charged water particles to be sprayed onto the target spraying area based on the charge polarity of the particulate mixture detected by the charge detector.As an example, the "control unit" controls the switching of the charge polarity of the charged water particles to a charge polarity opposite to the charge polarity of the particulate mixture detected by the charge detector.

[0029] As an example, the charged water particle spraying system is one in which multiple charged spray heads, a charged detector, and a suction device are provided at the end of the ladder of a ladder fire truck, the aerial work platform of an aerial work fire truck, or the end of the boom of a boom-equipped fire truck, and the multiple charged spray heads are moved close to exterior wall openings such as windows of a building that are the spraying target area, thereby efficiently injecting charged water particles into the building to enable fire extinguishing, fire prevention, and smoke suppression.

[0030] Specific embodiments will be described below. In the specific embodiments shown below, the "target spray area" is a "fire compartment of a building" and "multiple charged spray heads, a charged detector, and a suction device" are provided at the tip of the ladder of a ladder fire truck.

[0031] [Specific details of the embodiment] The specific contents of the embodiment will be described separately as follows. a. Overview of the charged water particle spraying system b. Charged water particle emission section b1.Blower section b2. Charged water particle generation unit b3. Electrostatic spray head b4. Release direction adjustment part c. High voltage power supply c1. Circuit configuration of the electrolytic water particle generator c2. High voltage variable circuit c3. Reversing circuit c4. Application of high voltage c5. Abnormal current detection circuit d. Fire extinguishing agent supply section e. Charge polarity switching control of charged water particles e1.Suction device e1-1. Sampling tube e1-2.Tube e2. Holding device e3. Charge detector e3-1. Electrode structure e3-2. Charge detection unit e3-3. Operation of the charge detection unit e4. Judgment section e5. Switching control of the charging polarity of charged water particles f. Fire type and water particle charge polarity f1. Charging polarity of water particles for wood fires f2. Charging polarity of water particles in an oil fire f3. Initial setting of water particle charging polarity g.Operation panel h. Ladder fire engine equipped with an electrocharged water particle spray system i. Control operation of the charged water particle spray system j. Modifications of the present invention

[0032] [a. Overview of the charged water particle spraying system] The charged water particle spraying system of this embodiment is mounted on a fire engine such as a ladder fire truck and sprays charged water particles toward a target area. Its configuration and structure are arbitrary, but for example, as shown in FIG. 1, it includes a charged water particle discharge unit 10, an operation panel 14, a fire extinguishing agent supply unit 16, a high-voltage power supply unit 18, a charge detector 80, and a suction device 82, and the operation panel 14 is provided with an operation display unit 20 and a control unit 21.

[0033] The charged water particle discharge unit 10 includes an air blower 28 and an electrically charged water particle generator 30, and is mounted on a stand 40 so as to be rotatable in the vertical and horizontal directions. A water supply pipe 22 from the extinguishing agent supply unit 16, a high-voltage cable 24 from the high-voltage power supply unit 18, and signal cables 26e and 26f are connected to the discharge pipe 22, and signal cables 26a and 26d from the control unit 21 of the operation panel 14 are also connected to the discharge direction adjuster 26a. The signal cable 26a is connected to the discharge direction adjuster of the air blower 28, and the signal cables 26d, 26e, and 26f are connected to an on-off valve, a switch circuit, and a current detection resistor provided for each of the multiple electrically charged spray heads arranged in the charged water particle generator 30.

[0034] The charge detector 80 is provided on the side of the charged water particle discharge section 10 and detects the charge polarity of the particles contained in the particle mixture sucked by the suction device 82, and is connected to a signal cable 26c from the control section 21 of the operation panel 14.

[0035] The suction device 82 is provided on the side of the charged water particle discharger 10, and sucks in a particulate air-fuel mixture containing smoke particles from a fire that has occurred from the fire compartment side of the building toward the charge detector 80. In addition, a signal cable 26b from the control unit 21 of the operation panel 14 is connected to the suction pump 88. The specific configuration and structure of the suction device 82, including an explanation of the components assigned reference numerals in FIG. 1, will be described later.

[0036] 1, the X, Y, and Z directions are perpendicular to each other. Specifically, when looking at the front face of the charged water particle generator 30 arranged on the stand 40 in a non-rotating state, the X direction is the left-right direction (not shown in FIG. 1), the Y direction is the up-down direction, and the Z direction is the front-to-back direction. Furthermore, the +X side of the X direction is the right side, and the -X side is the left side. The +Y side of the Y direction is the upper side, the -Y side is the lower side, and the +Z side of the Z direction is the front side, and the -Z side is the rear side. This also applies to FIGS. 2 and 6, which illustrate embodiments of the present invention.

[0037] [b. Charged water particle emission section] A more detailed description will be given of the charged water particle emitting unit 10. The charged water particle emitting unit 10 emits a charged water particle airflow 12 containing charged water particles, thereby dispersing the charged water particles toward a fire compartment of a building that includes a target for fire extinguishing or fire prevention. The configuration and structure of the unit are arbitrary, but it may include, for example, an air blower 28 and a charged water particle generator 30.

[0038] The blower 28 generates an airflow toward the fire compartment, and a plurality of charged spray heads provided in the charged water particle generator 30 arranged at the outlet of the blower 28 spray charged water particles into the airflow from the blower 28 to contain the charged water particles, and the charged water particle airflow 12 containing the charged water particles is discharged toward the fire compartment. The charged water particle discharger 10 is provided, for example, at the tip of the ladder of a ladder fire engine, and discharges the charged water particle airflow 12 from the outside of a building or other structure where a fire has occurred through an exterior wall opening such as a window into the fire compartment to extinguish the fire.

[0039] FIG. 2 shows the charged water particle emission unit 10 of FIG. 1 in more detail, with FIG. 2(A) showing a rear view from the rear, FIG. 2(B) showing a side view from the left, and FIG. 2(C) showing a front view from the front.

[0040] (b1.Blower section) The blower 28 will now be described in more detail. The blower 28 has an axial fan 34 driven by a fan motor 36, for example, disposed within a cavity that is open at the front and rear. The rotation of the axial fan 34 pressurizes air drawn in through the rear opening and releases the airflow from the front opening. The volume of the airflow released from the blower 28 is arbitrary, but for example, the maximum volume is approximately 400 m3 / min. The air volume can also be changed as needed by changing the rotation speed of the axial fan 34 using the fan motor 36.

[0041] When the charged water particle discharge unit 10 is provided at the tip of the ladder of a ladder fire engine, the charged water particle discharge unit 10 can be placed within several meters of the fire compartment of the building, and therefore the airflow rate of the blower unit 28 is set so that the reach of the charged water particle airflow 12 to the fire compartment is, for example, about 10 meters. In addition, a protective cover 38 made of a multiple ring, wire mesh, or the like is attached to the rear opening of the blower unit 28.

[0042] (b2. Charged water particle generation unit) The charged water particle generator 30 will be described in more detail. The charged water particle generator 30 is disposed on the front opening side of the blower 28. When viewed from the front of the charged water particle discharger 10 as shown in FIG. 2(C), the charged water particle generator 30 has, for example, ten charged spray heads 32 arranged in a ring shape inside a support ring 31. Here, the spray axis of each charged spray head 32 is disposed so as to intersect with the discharge axis 25 of the charged water particle airflow 12, and when viewed from the left side of the charged water particle discharger 10 as shown in FIG. 2(B), the spray axis of each charged spray head 32 is disposed so as to intersect with the discharge axis 25 at point P in front of the discharge axis 25.

[0043] The intersection angle θ between the spray axis of the charged spray head 32 and the discharge axis 25 of the charged water particle airflow 12, which intersect at point P, is a predetermined angle that allows the sprayed charged water particles to be well contained in the airflow, taking into consideration the spray speed and spray spread angle of the charged water particles from the charged spray head 32, the wind speed of the airflow from the blower section 28, etc., and is, for example, a predetermined angle in the range of 45° to 90°, for example 60°.

[0044] (b3. Electrostatic spray head) Next, we will explain in more detail the electrically charged spray head 32 provided in the charged water particle generator 30 in Fig. 2. Fig. 3 shows the electrically charged spray head 32, with Fig. 3(A) showing a perspective view from the spray side and Fig. 3(B) showing a cross-sectional view from the side.

[0045] 3, the electrically charged spray head 32 sprays electrically charged water particles into the airflow from the air blower 28, and although its configuration and structure are arbitrary, one example is one that is made up of a body 54, a spray nozzle 56, an electrode holder 58, an induction electrode 60, a water-side electrode 62, and a water supply connector 64. The body 54, the spray nozzle 56, the electrode holder 58, and the water supply connector 64 are made of insulating materials.

[0046] A through hole is formed inside body 54 in the direction of spray axis 55, and conductive water-side electrode 62 is fitted into it from the spray side, with water supply connector 64 fitted into the upper side, and an earth cable is connected from the outside to electrode connector 62a of water-side electrode 62. Pressurized fire-fighting water, for example, is supplied as a fire extinguishing agent to water supply connector 64. Spray nozzle 56 is provided on the spray side of water-side electrode 62, and sprays water droplets with an average particle diameter of, for example, 100 to 300 μm.

[0047] A ring-shaped induction electrode 60 is disposed in the open space on the spray side of spray nozzle 56 by electrode holder 58. The induction electrode 60 may have any configuration or structure, but may be formed, for example, by insulating a conductive electrode core material. An external voltage application cable is connected to cable connection 60a of induction electrode 60.

[0048] A predetermined voltage (e.g., a DC voltage of 10 kV) adjusted within a predetermined adjustment range (e.g., 0.5 kV to 20 kV) within the voltage range capable of charging water particles is applied between induction electrode 60 and water-side electrode 62 from high-voltage power supply 18 shown in Fig. 1. This applied voltage creates a predetermined external electric field around the ring portion of induction electrode 60, and water particles sprayed from spray nozzle 56 are charged by induction charging as they pass through the ring portion of induction electrode 60.

[0049] Here, the predetermined adjustment range (i.e., the predetermined adjustable range) may include a voltage range in which the water particles cannot be charged, and it is sufficient if the voltage can be adjusted to a predetermined voltage that can charge the water particles. The polarity (positive / negative) of the applied voltage is switched by the high-voltage power supply unit 18.

[0050] When a predetermined DC voltage is applied to the induction electrode unit 60 so that the potential of the induction electrode unit 60 is positive, with the water-side electrode unit 62 at the reference potential (earth potential, 0 V), the water particles sprayed from the spray nozzle unit 56 are negatively charged. When a predetermined DC voltage is applied to the induction electrode unit 60 so that the potential of the induction electrode unit 60 is negative, with the water-side electrode unit 62 at the reference potential (earth potential, 0 V), the water particles sprayed from the spray nozzle unit 56 are positively charged. When the absolute value of the voltage applied between the induction electrode unit 60 and the water-side electrode unit 62 is set in the range of 0.5 kV to 20 kV, for example, spark discharge is prevented, and a spray of charged water particles is generated while ensuring safety.

[0051] The configuration and structure of the charged spray head 32 are arbitrary and are not limited to those shown in Figure 3. Any appropriate structure or known structure can be adopted that can generate water particles and charge the generated water particles to spray charged water particles.

[0052] (b4. Release direction adjustment part) The following provides a more detailed description of the emission direction adjustment unit provided in the charged water particle emitter 10. The emission direction adjustment unit adjusts the emission direction of the charged water particle airflow 12 from the charged water particle emitter 10, and while the configuration and structure thereof are arbitrary, as an example, a left-right direction adjustment unit 44 and a up-down direction adjustment unit 48 are provided as shown in FIG.

[0053] The blower 28 of the charged water particle emitter 10 is supported on a base 40 by a rotary support 42 so as to be rotatable in the left-right direction about a left-right rotary shaft 46 as a rotary shaft, and is also supported so as to be rotatable in the up-down direction about a vertical rotary shaft 50 as a rotary shaft. In addition, a left-right direction adjustment unit 44 is disposed below the base 40. The left-right direction adjustment unit 44 is, for example, motor-driven, and by supporting the rotary support 42 so that the left-right rotary shaft 46 is positioned on the drive shaft, the charged water particle emitter 10 can be rotated in the left-right direction about the left-right rotary shaft 46 as a rotary shaft, thereby making it possible to adjust the left-right emission direction of the charged water particle airflow 12.

[0054] Furthermore, a vertical direction adjustment unit 48 is disposed on the right side of the rotation support unit 42, where the vertical rotation shaft 50 is located. The vertical direction adjustment unit 48 is, for example, motor-driven, and by supporting the rotation support unit 42 so that the vertical rotation shaft 50 is located on the drive shaft, the charged water particle discharge unit 10 can be rotated in the vertical direction around the vertical rotation shaft 50 as the rotation axis, thereby making it possible to adjust the vertical discharge direction of the charged water particle airflow 12.

[0055] Here, the left-right pivot shaft 46 and the up-down pivot shaft 50 are adjusted to be at predetermined positions forward (on the release side) of the center of gravity 52 of the charged water particle discharger 10. Therefore, the release direction of the charged water particle airflow 12 discharged by the charged water particle discharger 10 is stable even when subjected to a recoil, and the operator can easily adjust the release direction to the intended direction. Furthermore, in cases where the charged water particle discharger 10 is installed in a basket section provided at the end of the ladder of a ladder fire truck, the release direction of the charged water particle airflow 12 from the charged water particle discharger 10 is highly stable even when the basket section is tilted, so the release direction of the charged water particle airflow 12 can be prevented from being directed in an unexpected direction, ensuring safe operation.

[0056] [c. High voltage power supply] The high-voltage power supply unit 18 will be described in more detail. The high-voltage power supply unit 18 supplies a high voltage for generating charged water particles to the charged-water particle emitter 10 via a high-voltage cable 24. The configuration and function of the high-voltage power supply unit 18 are arbitrary, but for example, as shown in Fig. 4, it may include a high-voltage variable circuit 66 that adjusts the supplied voltage, a polarity reversal circuit 68 that switches the polarity of the supplied voltage, an abnormal current detection circuit 74 that detects an abnormal current flowing between the induction electrode unit 60 and the water-side electrode unit 62 of the charged spray head 32 and functions as an abnormal current detector, and a selection circuit 72 that switches between applying and stopping voltage application to the charged spray head 32. In Fig. 4, the cable connected to the induction electrode unit 60 side of the high-voltage cable 24 is referred to as a voltage application cable 24a, and the cable connected to the water-side electrode unit 62 side is referred to as an earth cable 24b.

[0057] (c1. Circuit configuration of the charged water particle generator) The circuit configuration of the charged water particle generator 30, which is connected to the high-voltage power supply 18 via the high-voltage cable 24, will be described in more detail below. Fig. 4 shows the circuit configuration of the charged water particle generator 30, which includes the high-voltage power supply 18 and multiple charged spray heads 32. Each charged spray head 32 includes an induction electrode 60 and a water-side electrode 62. A voltage application cable 24a from the high-voltage power supply 18 branches off for each charged spray head 32 and is connected to the induction electrode 60 of each charged spray head 32 via a switch circuit 75 and a current-limiting resistor 76. The water-side electrode 62 of each charged spray head 32 is also commonly connected via a current-detecting resistor 78, to which an earth cable 24b from the high-voltage power supply 18 is connected via a switch 77 circuit.

[0058] Normally, switch circuits 75 and 77 are on, and high-voltage power supply 18 applies a high voltage between induction electrode 60 and water-side electrode 62, charging the water particles sprayed from charged spray head 32. Here, voltage application cable 24a and earth cable 24b use highly insulating, high-voltage cables, but when applying DC voltage, the positive cable should be a high-voltage cable and the negative cable can be a normal low-voltage cable.

[0059] (c2. High voltage variable circuit) High-voltage variable circuit 66 will now be described in more detail. High-voltage variable circuit 66 adjusts the voltage applied between induction electrode unit 60 and water-side electrode unit 62 in response to a control signal from control unit 21 of operation panel 14, thereby enabling charged water particle airflow containing charged water particles with a charge appropriate for fire extinguishing and smoke suppression to be emitted from charged spray head 32 into the fire compartment. Furthermore, by lowering the absolute value of the applied voltage, the charged water particles have a reduced charge, making it possible to prevent discharge accidents that could occur due to an increase in the charge of the charged water particles on fire-extinguishing or fire-prevention targets that are easily charged.

[0060] (c3. Reversing circuit) The polarity reversing circuit 68 will be described in more detail. The polarity reversing circuit 68 switches the polarity of the voltage applied between the induction electrode unit 60 and the water-side electrode unit 62 in response to a control signal from the control unit 21 of the operation panel 14. This switches the polarity of the charged water particles sprayed from the charged spray head 32 between positive and negative polarity, allowing a charged water particle airflow containing charged water particles of a polarity suitable for fire and smoke extinguishing to be emitted into the fire compartment. For example, by emitting a charged water particle airflow containing charged water particles charged with the opposite polarity to the polarity of the particulate air mixture generated in the fire compartment, better fire and smoke extinguishing performance can be expected.

[0061] (c4. Application of high voltage) The case where a high voltage is applied between the induction electrode section 60 and the water-side electrode section 62 of the charged spray head 32 from the high-voltage power supply section 18 will be described in more detail below, taking as an example the case where a DC voltage is applied.

[0062] High voltage variable circuit 66 adjusts the voltage output from high voltage variable circuit 66 to a predetermined DC voltage in response to a control signal from control unit 21 of operation panel 14. Here, "adjusting to a predetermined DC voltage" means adjusting to a DC voltage that can charge water particles, for example, adjusting to a DC voltage selected from the range of 0.5 kV to 20 kV (+0.5 kV to +20 kV or -0.5 kV to -20 kV), which is the voltage range that can charge water particles.

[0063] The polarity reversing circuit 68 determines whether or not to switch the polarity of the specified DC voltage adjusted and output by the high-voltage variable circuit 66 in response to a control signal from the control unit 21 of the operation panel 14, and adjusts the polarity of the DC voltage applied between the induction electrode unit 60 and the water side electrode unit 62.

[0064] For example, if high-voltage variable circuit 66 adjusts the predetermined DC voltage to +10 kV DC (positive DC), and polarity switching is not performed by polarity reversal circuit 68, the potential of induction electrode unit 60 becomes +10 kV with water-side electrode unit 62 at the reference potential (earth potential, 0 V), and a +10 kV DC voltage (positive DC voltage) that increases the potential of induction electrode unit 60 relative to the potential of water-side electrode unit 62 is applied between induction electrode unit 60 and water-side electrode unit 62. As a result, the water particles sprayed from charged spray head 32 are negatively charged.

[0065] On the other hand, when high-voltage variable circuit 66 adjusts the predetermined DC voltage to +10 kV DC (positive DC voltage) and polarity is switched by polarity reversal circuit 68, the potential of induction electrode unit 60 becomes -10 kV with water-side electrode unit 62 at the reference potential (earth potential, 0 V), and a DC voltage of -10 kV (negative DC voltage) that makes the potential of induction electrode unit 60 lower than the potential of water-side electrode unit 62 is applied between induction electrode unit 60 and water-side electrode unit 62. As a result, the water particles sprayed from charged spray head 32 are positively charged.

[0066] (c5. Abnormal current detection circuit) The abnormal current detection circuit 74, which functions as an abnormal current detector, will now be described in more detail. The abnormal current detection circuit 74 detects abnormal currents flowing due to an insulation abnormality between the induction electrode 60 and the water-side electrode 62 for each of the multiple charged spray heads 32. Here, an insulation abnormality refers to an abnormality in electrical insulation, and is a concept that includes insulation degradation, insulation failure, insulation breakdown, short circuit, etc.

[0067] A series circuit of a current limiting resistor 76, induction electrode section 60, water side electrode section 62 and current detection resistor 78 is provided on the branch line of the voltage application cable 24a which branches off for each charged spray head 32, and the signal cable 26f from the abnormal current detection circuit 74 is connected to the water side electrode section 62 side of each current detection resistor 78 by separate signal lines, and the earth cable 24b is connected to the abnormal current detection circuit 74, so that the voltage across both ends of each current detection resistor 78 is input to the abnormal current detection circuit 74 as a current detection voltage signal.

[0068] Here, the resistance value of current limiting resistor 76 is a predetermined value, for example, in the range of 1 to 10 MΩ, and the resistance value of current detection resistor 78 is any value that is sufficiently lower than the resistance value of current limiting resistor 76, for example, a predetermined resistance value in the range of 1 to 10 kΩ. Specifically, the resistance value of current detection resistor 78 is determined so that the voltage across current detection resistor 78 due to an abnormal current flowing due to an insulation abnormality in charged spray head 32 is below a predetermined low voltage, for example, 10 V or less. That is, the current flowing through current detection resistor 78 reaches a maximum when a short circuit occurs between induction electrode 60 and water-side electrode 62 of charged spray head 32, and the voltage across current detection resistor 78 also reaches a maximum voltage. Therefore, the resistance value of current detection resistor 78 is determined so that this maximum voltage is below, for example, 10 V.

[0069] Furthermore, because signal cable 26f is connected to the water-side electrode 62 side of each current detection resistor 78 by a separate signal line, abnormal current detection circuit 74 can detect abnormal currents due to poor insulation for each charged spray head 32. In this embodiment, ten charged spray heads 32 are provided (see FIG. 2), and the abnormal current detection circuit 74 outputs one of abnormal current detection signals E1 to E10 to control unit 21 corresponding to the charged spray head 32 in which an abnormal current has been detected. The configuration and function of the comparator are arbitrary, but for example, a number of comparators corresponding to the number of charged spray heads 32 are provided. For example, a current detection voltage signal, which is the voltage across current detection resistor 78 provided on the corresponding charged spray head 32 side, is input to the comparator, and when the current detection voltage signal is equal to or exceeds a predetermined threshold voltage, the comparator detects an abnormal current and outputs an abnormal current detection signal that rises from L level to H level.

[0070] The type and configuration of the comparator that operates in this manner may be arbitrary, but a Schmitt trigger circuit, for example, may be used. The Schmitt trigger circuit outputs an abnormal current detection signal by rising from L level to H level when the current detection voltage signal exceeds a first threshold voltage, and then stops outputting the abnormal current detection signal by falling from H level to L level when the current detection voltage signal falls below a second threshold voltage that is lower than the first threshold voltage. This allows the output of a stable abnormal current detection signal to be produced despite fluctuations in the current detection voltage signal due to the so-called hysteresis characteristic.

[0071] In this way, the current detection resistor 78 and the abnormal current detection circuit 74 are provided on the reference potential side, the resistance value of the current detection resistor 78 is sufficiently low compared to the resistance value of the current limiting resistor 76, and the circuit is configured so that the voltage across the current detection resistor 78 due to an abnormal current flowing due to an insulation abnormality in the charged spray head 32 is low.As a result, no special high-voltage circuit components are required for the abnormal current detection circuit 74, and since high voltage is not applied to the abnormal current detection circuit 74, there is no need for an insulation structure that can withstand high voltages, so the insulation structure can be simplified, and charged spray heads 32 that have experienced an insulation abnormality can be detected simply and easily from among multiple charged spray heads 32, without compromising safety.

[0072] The control unit 21 receives abnormal current detection signals E1-E10 from the abnormal current detection circuit 74, and when any of the abnormal current detection signals E1-E10 is received, the control unit 21 determines whether an abnormal current has been detected in the charged spray head 32 corresponding to the received abnormal current detection signal, and performs control to stop the application of high voltage to the charged spray head 32 in which the abnormal current has been detected. To perform this stop control, a selection circuit 72 is provided in the high-voltage power supply unit 18, and a switch circuit 75 is provided in each branch line of the voltage application cable 24a. The selection circuit 72 receives control signals from the control unit 21 that turn the switch circuit on and off, and the signal cable 26e from the selection circuit 72 is connected to each switch circuit 75 by a separate signal line.

[0073] In response to a control signal from the control unit 21, the selection circuit 72 outputs an OFF activation signal to the switch circuit 75 corresponding to the charged spray head 32 in which an abnormal current has been detected, turning it off, thereby stopping the application of high voltage to the charged spray head 32 in which an abnormal current has been detected, and ensuring the safety of the operator.

[0074] Furthermore, when the control unit 21 receives any of the abnormal current detection signals E1 to E10 and determines that an abnormal current has been detected in any of the charged spray heads 32, it may stop the application of voltage to all of the charged spray heads 32. To perform this simultaneous stop control, a switch circuit 77 is provided in the line between the earth cable 24b and the current detection resistor 78, and the signal cable 26e from the selection circuit 72 is connected to the switch circuit 77 by a signal line separate from the switch circuit 75. In this case, the selection circuit 72 outputs an OFF activation signal to all of the switch circuits 75 and 77 in response to a control signal from the control unit 21, turning them off and thereby stopping the application of high voltage to all of the charged spray heads 32.

[0075] [d. Fire Extinguishing Agent Supply Section] The extinguishing agent supply unit 16 shown in Fig. 1 will be described in more detail. The extinguishing agent supply unit 16 supplies, for example, fire-extinguishing water as an extinguishing agent to the charged water particle discharge unit 10, and although the configuration and structure thereof are arbitrary, as an example, since the charged water particle spraying system of this embodiment is mounted on a ladder fire truck, the extinguishing agent supply unit 16 is configured as a pressurized water supply device or pressurized water supply facility including a fire pump provided on the fire truck. In this case, water sources include a water tank mounted on the fire truck and a fire hydrant connected to a hose. The extinguishing agent supply unit 16 is operated by operating the discharge start or discharge stop switch on the control panel 14 to start and stop the supply of fire-extinguishing water.

[0076] Furthermore, the water supply pipe 22 from the fire extinguishing agent supply unit 16 branches off at the connection portion with the charged water particle discharge unit 10 and is connected via an on-off valve 35 to a plurality of charged spray heads 32 provided in the charged water particle generation unit 30 of the charged water particle discharge unit 10. Furthermore, when the charged water particle spraying system is mounted on a ladder fire truck, the water supply pipe 22 has a known expandable piping structure in the ladder portion of the ladder fire truck that expands and contracts according to the length of the ladder.

[0077] Each on-off valve 35 provided corresponding to each charged spray head 32 is connected to signal cable 26d from control unit 21 by a separate signal line, and is driven to open and close individually in response to control signals from control unit 21. Control unit 21 performs control to adjust the amount of charged water particles sprayed from each of the multiple charged spray heads 32, for example, based on operation by an operator. The method for adjusting the amount of spray is arbitrary, but for example, the number of on-off valves 35 that are driven open may be changed, or the amount of fire-extinguishing water supplied from fire-extinguishing agent supply unit 16 may be changed to adjust the amount of spray from each of the charged spray heads 32.

[0078] [e. Charge polarity switching control of charged water particles] A more detailed description will be given below of the charge polarity switching control of the charged water particles contained in the charged water particle airflow emitted from the charged water particle emitting unit 10. The charge polarity switching control of the charged water particles contained in the charged water particle airflow emitted from the charged water particle emitting unit 10 is performed by the suction device 82, the charge detector 80, and the control unit 21 of the operation panel 14 shown in FIG.

[0079] (e1. Suction device) The suction device 82 will be described in more detail. The suction device 82 sucks in a particulate mixture containing smoke particles from a fire that has occurred from the fire compartment side toward the charging detector 80, and while its structure and function are optional, for example, as shown in Fig. 6, it is composed of a sampling pipe 84, tubes 85 and 86, a suction pump 88, a rod member 90, a support part 92, and a weight 94. Of these, the rod member 90, the support part 92, and the weight 94 function as a holding device that holds the sampling pipe 84 and the tube 85 movably.

[0080] (e1-1. Sampling tube) The sampling pipe 84 will now be described in more detail. The sampling pipe 84 is a hollow member that sucks in the particulate gas mixture in the fire compartment of the building from the suction port 84a at its tip, and since it is inserted into the fire compartment, it needs to be heat-resistant, for example, a metal pipe that can withstand the heat of a fire, and is further insulated from the supporting rod member 90 and the connected tube 85 so as to be in a non-grounded state. The diameter and length of the sampling pipe 84 are optional, but the diameter is set to, for example, about 2 to 3 cm and the length to about 1 to 2 m so that the operator can suck in the particulate gas mixture from the suction port 84a at the tip of the sampling pipe 84 while maintaining a safe distance from the fire compartment.

[0081] (e1-2.Tube) The tube 85 will be described in more detail. The tube 85 is a flexible hollow member that connects the sampling pipe 84 to the inlet of the charge detector 80, and may have any structure or material, but may be, for example, a flexible tube or hose made of synthetic resin or rubber.

[0082] A heating section 85a is provided on one end of the tube 85 connected to the inlet of the charge detector 80. The heating section 85a heats the space inside the tube 85 through which the particulate gas mixture sucked from the sampling pipe 84 passes, in order to suppress or prevent condensation on the inner wall of the tube due to the suction of the particulate gas mixture. The heating section 85a has any structure and function, but may be, for example, a self-regulating heater wire that generates heat when current is applied and is wound around the tube 85.

[0083] The particulate mixture drawn into the sampling tube 84 from the fire compartment is hot, and contains water vapor in addition to particulates (smoke particles). The drawn-in high-temperature particulate mixture is cooled as it passes through the sampling tube 84 and the tube 85, which can cause condensation on the inner wall of the tube. When condensation occurs on the inner wall of the tube 85, the particulates of the drawn-in particulate mixture are attracted to the water droplets on the inner wall of the tube, resulting in a partial loss of the particulates contained in the particulate mixture. Therefore, by providing a heating unit 85a to heat the tube 85, condensation caused by the cooling of the particulate mixture can be suppressed or prevented, allowing the particulate mixture to reach the inlet of the charge detector 80 without losing the particulates contained therein, thereby improving the detection accuracy of the charge polarity of the particulate mixture.

[0084] In this embodiment, the heating unit 85a is provided on one end of the tube 85 connected to the charge detector 80, but any suitable position may be used as long as condensation can be suppressed or prevented. Similarly, a heating unit may also be provided on the sampling pipe 84 to suppress or prevent condensation on the inner wall of the sampling pipe 84.

[0085] (e1-3. Suction pump) The suction pump 88 will be described in more detail. The suction pump 88 has a suction port connected to the outlet of the charge detector 80 via a tube 86, sucks in the particulate gas mixture via a sampling pipe 84 and a tube 85, and exhausts the particulate gas mixture that has passed through the charge detector 80 to the outside. The structure and function of the suction pump 88 are arbitrary, but an appropriate pump such as an axial flow pump that is driven by a motor to suck in and exhaust gas is used. The structure and material of the tube 86 are arbitrary, but it is preferably a tube, hose, or the like made of synthetic resin or rubber, similar to the tube 85 described above.

[0086] (e2. Holding device) The holding device will be described in more detail below. The holding device movably holds the sampling pipe 84 and the tube 85 so that the suction port 84a of the sampling pipe 84 is inserted into the particulate mixture generated in the fire compartment. The structure and function of the holding device are arbitrary, but it may be composed of, for example, a rod member 90, a support 92, and a weight 94.

[0087] The rod member 90 is a long member that holds the sampling tube 84 and the tube 85 along the extension direction of the tube 85, and its structure and function are arbitrary, for example, a metal rod or pipe that has rigidity in the front-to-rear direction, which is the extension direction of the tube 85, and its length is also arbitrary, for example, about 2 to 3 m. Furthermore, the rod member 90 is arranged so that when the tube 85 is fully retracted, the tip of the rod member 90 is positioned on the outer periphery of the suction port 84a side of the sampling tube 84, and when the tube 85 is extended while holding the sampling tube 84 and the tube 85 in this state, the tip of the rod member 90 moves around the outer periphery of the sampling tube 84 in the extension direction, while maintaining its holding state of the sampling tube 84 and the tube 85.

[0088] Furthermore, if the tip of the rod member 90 is also inserted into the fire compartment depending on the insertion amount of the sampling tube 84 into the fire compartment, the rod member 90 should be made of a heat-resistant material similar to the sampling tube 84. Furthermore, instead of a material having rigidity in the extension direction of the tube 85, the rod member 90 may be made of a flexible material, with the contact point between the tip of the rod member 90 and the outer periphery of the suction port 84a side of the sampling tube 84 fixed, and the rod member 90 may be made to extend (retract) in accordance with the extension (retraction) of the tube 85.

[0089] The support portion 92 supports the rod member 90 movably so that the position of the sampling pipe 84 and tube 85 held by the rod member 90 can be adjusted so that the intake port 84a of the sampling pipe 84 can be positioned at any position corresponding to the fire compartment.

[0090] The structure and mechanism of the support part 92 are arbitrary, but for example, it may be a three-dimensional swiveling structure, and as a mechanism for realizing the three-dimensional swiveling structure, for example, a fixed base 92a is placed on top of the blower part 28, and a support shaft part 92b which serves as a support shaft in the vertical direction is erected on the fixed base 92a, and the support shaft part 92b supports, at its upper end, for example, a U-shaped support part 92c which detachably supports the rod member 90 so that it can rotate freely around the support shaft (left and right), and also supports it so that it can rotate freely around a horizontal axis (up and down) located at the height of the support part 92c in the left and right direction perpendicular to the support shaft.

[0091] By supporting the rod member 90 on the support portion 92c of the bearing portion 92, the rod member 90 can move not only in the forward and backward direction, which is the extension direction, but also left and right and up and down, and the tip of the rod member 90, which is located on the fire compartment side and is arranged on the outer periphery of the sampling pipe 84, can be rotated left and right and up and down. This makes it possible to adjust the position of the intake port 84a of the sampling pipe 84 in all directions, up and down, left and right, and forward and backward.

[0092] Furthermore, a weight 94 is disposed on the rear end side of the rod member 90. The weight 94 is set in weight so that the moment of force at the tip side of the rod member 90, which holds the sampling pipe 84 and tube 85, with the support part 92 as a fulcrum, is approximately equal to the moment of force at the rear end side where the weight 94 is disposed, thereby balancing the rod member 90 so that it remains horizontal.

[0093] Furthermore, the movement of the pole member 90 in the extension direction may be achieved by, for example, moving a basket 120 at the tip of an extendable ladder 118 shown in FIG.

[0094] (e3. Charge detector) The charge detector 80 will be described in more detail. The charge detector 80 detects the charge polarity of the particulates (smoke particles) contained in the particulate mixture generated in the fire compartment, i.e., whether the charge polarity of the particulates is negative or positive, and the configuration, structure, and function thereof are arbitrary. For example, as shown in Fig. 7(A) in the cross section taken out and viewed from the left of Fig. 6, the charge detector 80 is composed of an electrode structure, a charge detection unit 105, and a determination unit 114. Note that Fig. 7(B) shows the electrode structure and the charge detection unit 105 as viewed from the rear.

[0095] (e3-1. Electrode structure) A more detailed description will be given of the electrode structure of the charge detector 80. The electrode structure of the charge detector 80 is arbitrary, but may be configured with a cylindrical electrode 95 and a Faraday cage 96, for example.

[0096] The cylindrical electrode 95 is an electrode conductor formed in a cylindrical shape having a hollow portion, and allows the particulate gas mixture 100 sucked by the suction device 82 to pass from the inlet side at one end of the hollow portion to the outlet side at the other end. Here, Fig. 7 shows a cylindrical cylindrical electrode 95, but it is not limited to a cylindrical shape, and the cross section of the cylindrical electrode 95 may be polygonal, elliptical, or the like, as long as it allows the particulate gas mixture to pass from the inlet side at one end of the hollow portion to the outlet side at the other end.

[0097] The Faraday cage 96 functions as an electromagnetic shield by covering the outer periphery of the cylindrical electrode 95 with a grounded conductor that is electrically insulated from the cylindrical electrode 95 and thereby creating a space that suppresses or prevents the influence of electrical disturbance factors (noise) on the cylindrical electrode 95. The Faraday cage 96 may have any structure or shape, but is composed of, for example, conductive outer cylindrical bodies 98a and 98b.

[0098] The outer cylinder 98a is arranged to surround the outer periphery of the entrance side of the cylindrical electrode 95, and is a stepped cylinder consisting of a large-diameter cylindrical section with a cylindrical hole that accommodates approximately half of the entrance side of the cylindrical electrode 95, and a small-diameter cylindrical section that serves as a visor through which the entrance hole passes, and a flange is provided at the end of the large-diameter cylindrical section. The cylindrical hole in the large-diameter cylindrical section has an inner diameter that is the outer diameter of the cylindrical electrode 95 plus an insulating space (insulating gap), and its length is the length from the entrance to approximately half of the cylindrical electrode 95 plus the insulating space (insulating gap). The entrance hole that passes through the small-diameter cylindrical section has an inner diameter that is the same as the inner diameter of the cylindrical electrode 95.

[0099] External cylinder body 98b is disposed surrounding the outer periphery of cylindrical electrode 95 on the outlet side, and has the same structure as external cylinder body 98a.

[0100] The Faraday cage 96 has the large-diameter cylindrical holes of the external cylinders 98a, 98b fitted into the inlet and outlet sides of the cylindrical electrode 95 via insulating rings 102, and the flanges of both are butted together and connected and fixed with screws, thereby covering the outer periphery of the cylindrical electrode 95 while electrically insulating the cylindrical electrode 95 from the outside of the Faraday cage 96. Also, as shown in Fig. 7(B) , the external cylinders 98a, 98b have flattened upper flanges, and a grounded conductor case 104 is attached and fixed to the flattened portions, thereby electrically grounding the Faraday cage 96.

[0101] Furthermore, in the Faraday cage 96, the length L of the small-diameter cylindrical portions of the external cylinders 98a, 98b is set to be at least twice the inner diameter D of the cylindrical electrode 95. By setting the length L of the small-diameter cylindrical portions of the external cylinders 98a, 98b to be at least twice the inner diameter D of the cylindrical electrode 95 in this manner, it is possible to suppress or prevent external noise from reaching the cylindrical electrode 95 via the entrance and exit of the Faraday cage 96.

[0102] The cylindrical electrode 95 surrounded by the Faraday cage 96 has a conductor 108 arranged standing upright at approximately the center of the upper outer periphery, and the conductor 108 is connected to the input of an operational amplifier 106 housed in a conductive case 104. For this reason, the Faraday cage 96 and the conductive case 104 are provided with openings for passing the conductor 108 through.

[0103] (e3-2. Charge detection unit) The charge detection unit 105 will be described in more detail. The charge detection unit 105 converts induced charges of the same polarity as the charged particles that are attracted to the outer circumferential surface of the cylindrical electrode 95 by the charges of the charged particles contained in the particle mixture 100 passing through the cylindrical electrode 95 into a voltage signal and outputs the voltage signal. The configuration and function of the charge detection unit 105 are arbitrary, but it may be composed of an operational amplifier 106 and a resistor 110, for example. In practice, the operational amplifier 106 and the resistor 110 are mounted on a circuit board 112.

[0104] The operational amplifier 106 has an inverting input terminal (negative input terminal) connected to the outer periphery of the cylindrical electrode 95 via a conductor 108, a non-inverting input terminal (positive input terminal) connected to the grounded conductor case 104, and an output terminal connected to the inverting input terminal via a resistor 110 for negative feedback and also connected to a determination unit 114, forming a circuit that converts induced charge into a voltage signal by utilizing the imaginary short operation (virtual ground operation) of the operational amplifier 106.

[0105] Here, the imaginary short operation of the operational amplifier 106 means that when negative feedback is applied to the operational amplifier 106 via the resistor 110, the operational amplifier 106 operates so that the potential difference between the non-inverting input terminal and the inverting input terminal becomes 0V (virtual ground).

[0106] (e3-3. Operation of the charge detection unit) The charge detection operation of the charge detection unit 105, which detects the charge of the charged particles contained in the particle mixture, will be described in more detail. Figure 8(A) shows the charge detection operation when the particles in the particle mixture passing through the cylindrical electrode 95 of the charge detection unit 105 are positively charged. When positively charged particles pass through the cylindrical electrode 95, a negative charge is attracted to the inner circumferential surface of the cylindrical electrode 95, and in response, an opposite positive charge is attracted to the outer circumferential surface of the cylindrical electrode 95. Therefore, in response to the positive charge attracted to the outer circumferential surface of the cylindrical electrode 95, the voltage on the inverting input terminal side of the operational amplifier 106 becomes higher than the voltage (ground potential, 0 V) ​​on the non-inverting input terminal. For this, it becomes +Vq.

[0107] At this time, the operational amplifier 106 performs an imaginary short operation, and the voltage +Vq at the inverting input terminal is made equal to the voltage (earth potential, 0V) at the non-inverting input terminal via the output terminal and resistor 110. A current Iq flows from the output terminal to the inverting input terminal via resistor 110 so that the voltage becomes equal to the positive voltage V. As a result, the output voltage of operational amplifier 106 becomes +Vq, and a charge detection voltage signal corresponding to the positive charge of the charged particle passing through cylindrical electrode 95 is output.

[0108] When particulate mixture 100 containing positively charged particulates passes through cylindrical electrode 95, the positive charge attracted to the outer surface of cylindrical electrode 95 increases as the distance from the inlet to conductor 108 decreases until the charged particulates reach the position where conductor 108 stands up. The positive charge peaks at the position where conductor 108 stands up, and then decreases with increasing distance from conductor 108. The charge detection voltage signal +Vq output by operational amplifier 106 also changes in response to the change in the positive charge attracted to the outer surface of cylindrical electrode 95. Furthermore, when the positively charged particulates leave cylindrical electrode 95, a negative charge, which is the opposite polarity, is attracted to the outer surface of cylindrical electrode 95. Therefore, at this timing, the charge detection voltage signal output by operational amplifier 106 changes to -Vq. That is, when a positively charged particle passes through the cylindrical electrode 95, the operational amplifier 106 outputs a charge detection voltage signal that differentially changes from a positive voltage +Vq to a negative voltage −Vq.

[0109] 8(B) shows the charge detection operation when the particles contained in the particulate gas mixture 100 passing through the cylindrical electrode 95 of the charge detection unit 105 are negatively charged. When negatively charged particles pass through the cylindrical electrode 95, a positive charge is attracted to the inner circumferential surface of the cylindrical electrode 95, and an opposite negative charge is attracted to the outer circumferential surface of the cylindrical electrode 95. Therefore, in response to the negative charge attracted to the outer circumferential surface of the cylindrical electrode 95, the voltage on the inverting input terminal side of the operational amplifier 106 increases relative to the voltage (earth potential, 0 V) ​​of the non-inverting input terminal. This results in -Vq.

[0110] At this time, the operational amplifier 106 performs an imaginary short operation, and the voltage -Vq at the inverting input terminal is connected to the output via a resistor 110, and the voltage at the non-inverting input terminal (ground potential, 0V) is set to the same voltage. A current Iq flows from the inverting input terminal to the output terminal via resistor 110 so that the negative polarity charge of the charged particle passing through cylindrical electrode 95 becomes -Vq. As a result, the output voltage of operational amplifier 106 becomes -Vq, and a charge detection voltage signal corresponding to the negative polarity charge of the charged particle passing through cylindrical electrode 95 is output. Furthermore, when a negative polarity charged particle exits cylindrical electrode 95, a positive polarity charge, which is the opposite polarity, is attracted to the outer surface of cylindrical electrode 95, and at this timing, the charge detection voltage signal output from operational amplifier 106 changes to +Vq. In other words, when a negative polarity charged particle passes through cylindrical conductor 95, operational amplifier 106 outputs a charge detection voltage signal that changes differentially from a negative voltage -Vq to a positive voltage +Vq.

[0111] (e4. Judgment section) The determination unit 114 will be described in more detail. In this embodiment, the detection of the charge polarity of the particulate gas mixture is performed by the determination unit 114 determining the charge polarity of the particulates contained in the particulate gas mixture 100 based on the charge detection voltage signal output from the charge detection unit 105. The determination unit 114 determines the charge polarity of the particulates contained in the particulate gas mixture 100 based on the charge detection voltage signal output from the charge detection unit 105 and outputs the result to the control unit 21. The determination method is arbitrary, but for example, the determination of the charge polarity of the charged particulates is based on the integration result of the charge detection voltage signal output from the charge detection unit 105, and the integration result of the charge detection signal voltage signal is generated in time series by occasionally integrating the input charge detection signal voltage signal.

[0112] The determination unit 114 determines that the charge polarity of the charged particles is negative if the integral value of the charge detection voltage signal from the generated integration result shows a decreasing trend over time, and determines that the charge polarity of the charged particles is positive if the integral value of the charge detection voltage signal shows an increasing trend over time. Note that the determination unit 114 may be provided in the control unit 21 instead of the charge detector 80.

[0113] (e5. Switching control of the charging polarity of charged water particles) The control of switching the charge polarity of the charged water particles by the control unit 21 will be described in more detail below. The control unit 21 controls switching so that the charge polarity of the charged water particles contained in the charged water particle airflow 12 released from the charged water particle release unit 10 becomes the opposite charge polarity to the charge polarity of the particles contained in the particulate gas mixture 100, based on the charge polarity of the particulates contained in the particulate gas mixture 100 determined by the determination unit 114 of the charge detector 80.

[0114] When the determination unit 114 of the charge detector 80 determines that the charge polarity of the particles contained in the particle mixture 100 is positive, the control unit 21 switches the charge polarity of the charged water particles contained in the charged water particle airflow 12 emitted from the charged water particle emission unit 10 to negative. When the charged water particle airflow 12 containing negatively charged water particles is emitted into the fire compartment, the positively charged particles (smoke particles) contained in the particle mixture are adsorbed to the negatively charged water particles by electrostatic force, captured and removed, thereby achieving high smoke extinguishing performance.

[0115] Here, the control unit 21 switches the charging polarity of the charged water particles to negative polarity by controlling the polarity reversal circuit 68 of the high-voltage power supply unit 18 so as to apply a high voltage that makes the potential of the induction electrode unit 60 of the charged spray head 32 positive relative to the potential of the water side electrode unit 62.

[0116] Furthermore, when the determination unit 114 of the charge detector 80 determines that the charge polarity of the particles contained in the particle mixture 100 is negative, the control unit 21 switches the charge polarity of the charged water particles contained in the charged water particle airflow 12 emitted from the charged water particle emission unit 10 to positive. When the charged water particle airflow 12 containing positively charged water particles is emitted, the negatively charged particles (smoke particles) contained in the particle mixture are adsorbed to the positively charged water particles by electrostatic force, captured and removed, thereby achieving high smoke elimination performance.

[0117] Here, the control unit 21 switches the charging polarity of the charged water particles to a positive polarity by controlling the polarity reversal circuit 68 of the high-voltage power supply unit 18 so as to apply a high voltage that makes the potential of the induction electrode unit 60 of the charged spray head 32 negative relative to the potential of the water side electrode unit 62.

[0118] [f. Fire type and polarity of charged water particles] The relationship between the charge polarity of the charged water particles contained in the charged water particle airflow 12 emitted from the charged water particle emitting unit 10 and the type of fire will be described in more detail below.

[0119] According to the findings of the present inventors, it has been experimentally confirmed that there is a specific correspondence between the type of fire and the charge polarity of the charged water particles in order to obtain high fire and smoke extinguishing performance.

[0120] (f1. Charging polarity of water particles for wood fires) A wood fire is a fire caused by the burning of cellulose-containing materials such as wood or paper, and produces relatively white or gray smoke (white smoke or ash smoke). For convenience, this term is used. Note that water vapor is not included in white smoke. When comparing the spraying of positively charged water particles to a wood fire with the spraying of negatively charged water particles, for example, the time it takes for the smoke concentration to drop to a predetermined level after spraying is started is shorter when negatively charged water particles are sprayed than when positively charged water particles are sprayed. Therefore, negatively charged water particles offer superior smoke suppression performance for wood fires.

[0121] (f2. Charging polarity of water particles in oil fires) Oil fires are fires caused by the combustion of liquid fuels containing hydrocarbons, oils and fats, synthetic resins, etc., and produce relatively black smoke (black smoke), so are conveniently called oil fires.When comparing oil fires when positively charged water particles are sprayed with those when negatively charged water particles are sprayed, for example, the time from the start of spraying until the smoke concentration decreases to a predetermined level is almost the same, and no difference in smoke suppression performance is observed, but it has been found that the smoke suppression performance of negatively charged water particles is not impaired even if the amount sprayed is reduced.

[0122] (f3. Initial setting of water particle charging polarity) It may take time for the determination unit 114 of the charge detector 80 of this embodiment to determine the charge characteristics of the particles contained in the particulate gas mixture generated in the fire compartment and for the control unit 21 to switch and control the charge polarity of the charged water particles, so it is necessary to initially set a predetermined charge polarity as the charge polarity of the charged water particles. In this case, as described above, in the case of an oil fire, there is no difference in the fire extinguishing and smoke suppression performance depending on the charge polarity of the charged water particles, and in the case of a wood fire, a negative charge polarity of the charged water particles provides better smoke suppression performance, so it is preferable to initially set the charge polarity of the charged water particles to a negative polarity.

[0123] Therefore, the control unit 21 is initially set so that the charged water particles contained in the charged water particle airflow 12 to be released into the fire compartment are charged to a negative polarity, and if the judgment unit 114 of the charge detector 80 judges that the charge polarity of the particulate mixture is negative, which is the same polarity as the charged water particles, during the release of the charged water particle airflow 12 containing charged water particles charged to a negative polarity according to the initial setting, the control unit 21 controls to switch the charging polarity so that the charged water particles are charged to the opposite positive polarity from the initially set negative polarity.

[0124] Here, the initial setting of the charged water particles to be negatively charged means that the high voltage power supply 18 is set to apply a high voltage to the charged spray head 32 so that the potential of the induction electrode section 60 of the charged spray head 32 is positive relative to the potential of the water-side electrode section 62 by performing the operation to start the release of the charged water particle airflow 12, without the need for an operator to perform the operation to set the polarity of the charged water particles.

[0125] [g.Control panel] The control panel 14 shown in Figure 1 will now be described in more detail. The control panel 14 is an operation unit that allows an operator to operate the charged water particle spraying system of this embodiment, and the operations that can be performed on the control panel 14 are arbitrary, but examples include starting and stopping the charged water particle discharge unit 10, adjusting the discharge direction of the charged water particle airflow 12 from the charged water particle discharge unit 10 and adjusting the spray amount from each charged spray head 32, selecting the type of voltage to be applied by the high-voltage power supply unit 18, adjusting the voltage, and switching the polarity.

[0126] The operation panel 14 is provided with an operation display unit 20 and a control unit 21. The operation display unit 20 is provided with various operation buttons, operation levers, displays, indicator lights, etc. required for remote operation of the charged water particle emitting unit 10. The control unit 21 outputs control signals based on operations by an operator via the operation display unit 20 to control the charged water particle emitting unit 10, etc., and although its function and configuration are arbitrary, it is, for example, formed by a computer circuit equipped with a CPU, memory, various input / output ports, etc., and predetermined control functions are realized by the execution of programs by the CPU.

[0127] [h. Ladder fire truck equipped with an electrocharged water particle spraying system] Fire extinguishing, fire prevention, and smoke suppression using a ladder fire truck equipped with the charged water particle spraying system of this embodiment will be described in more detail. Figure 9 is an explanatory diagram showing an example of fire extinguishing, fire prevention, and smoke suppression work at a fire scene using a ladder fire truck equipped with the charged water particle spraying system of this embodiment. The charged water particle discharge unit 10, charge detector 80, and suction device 82 shown in Figure 1 are provided in a basket 120 at the tip of a retractable ladder 118, and the control panel 14, extinguishing agent water supply unit 16, and high-voltage power supply unit 18 are provided on the ladder fire truck 76 side.

[0128] For example, if a fire breaks out on the third floor of a building 122, a ladder fire engine 116 that arrives at the fire scene extends its ladder 118 so that the charged water particle discharger 10 attached to the basket 120 approaches an exterior wall opening such as a window of the building. Next, by performing a discharge activation operation on the operation panel 14 to discharge the charged water particle airflow 12, fire-extinguishing water is supplied from the extinguishing agent water supply unit 16 to the charged water particle discharger 10, a high voltage is applied from the high-voltage power supply unit 18 to the charged water particle discharger 10, and further, the air blower 28 is activated by a control signal from the operation panel 14. As a result, the airflow from the air blower 28 contains negatively charged water particles sprayed from the charged spray head 32 in accordance with the initial setting, and the charged water particle airflow 12 is discharged toward the fire compartment 124.

[0129] Furthermore, with the ladder 118 extended and the charged water particle discharge unit 10 attached to the basket 120 positioned close to an exterior wall opening such as a window of the building, the sampling tube 84 of the suction device 82 disposed above the charged water particle discharge unit 10 is inserted into the particulate gas mixture containing smoke particles from the fire occurring in the fire compartment 124, the particulate gas mixture is sucked in by the suction device 82 so that it reaches the charge detector 80, and the charge polarity of the particulate gas mixture is detected by the charge detector 80. Furthermore, as described above, the position of the sampling tube 84 can be adjusted in the front-to-back, left-to-right, and up-down directions, so that an operator standing on the basket 120 can adjust the insertion position of the sampling tube 84.

[0130] After the discharge of the charged water particle airflow 12 has begun, the operator can adjust the direction of the charged water particle airflow 12 up and down and / or left and right by operating the operation panel 14, thereby adjusting the discharge direction of the charged water particle airflow 12 toward the fire compartment 124. Furthermore, the control unit 21 controls the switching of the charge polarity of the charged water particles so that the voltage polarity of the voltage applied by the high-voltage power supply unit 18 becomes the charge polarity opposite to the charge polarity of the particulate gas mixture detected by the charge detector 80.

[0131] In addition, depending on the situation of fire extinguishing or smoke suppression by the release of the charged water particle airflow 12, the operator adjusts the release direction of the charged water particle airflow 12, adjusts the applied voltage by the high-voltage power supply unit 18, or switches the applied voltage polarity, and releases the charged water particle airflow 12 containing charged water particles with an amount of charge and polarity suitable for fire extinguishing or smoke suppression at the fire site into the fire compartment 124, thereby performing fire extinguishing, fire prevention, and smoke suppression.

[0132] [i. Control operation of the charged water particle spraying system] An example of the control operation of the charged water particle spraying system by the control unit 21 will be described in more detail with reference to the flowchart of FIG.

[0133] The charged water particle spraying system is started, and the control operation shown in FIG. 10 is carried out by the control unit 21 of the operation panel 14 shown in FIG.

[0134] In FIG. 10, the control unit 21 initially sets the charge polarity of the charged water particles contained in the charged water particle airflow 12 to be discharged in step S1 to a negative polarity. When the control unit 21 determines in step S2 that an instruction to start discharge has been issued by an operator operating the control panel 14 to start discharge, the control unit 21 proceeds to step S3, starts the fire extinguishing agent supply unit 16, and supplies a fire extinguishing agent, for example, fire water, to the multiple charged spray heads 32 provided in the charged water particle discharge unit 10. In step S4, the water particles are negatively charged in accordance with the initial setting, and the charged water particle airflow 12 containing the negatively charged charged water particles is discharged toward the fire compartment.

[0135] Next, in step S5, the control unit 21 determines whether the charge polarity of the particulate mixture detected by the charge detector 80, that is, the charge polarity of the so-called particulates (smoke particles), is negative, and if the charge polarity of the particulate mixture is negative, the control proceeds to step S6, where the charge polarity of the charged water particles is switched to positive and the charged water particle airflow 12 is emitted. If the charge polarity of the charged water particles is already positive, no switching control is performed.

[0136] On the other hand, if it is determined in step S5 that the charged polarity of the particulate mixture is not negative, i.e., that the charged polarity of the particulate mixture is positive, the process proceeds to step S7, where the charged polarity of the charged water particles is switched to negative and the charged water particle airflow 12 is emitted. However, when the process first proceeds to step S7, the water particles are initially charged to negative polarity in step S4 based on the initial setting, and therefore no switching control is performed to maintain the negative charged polarity.

[0137] Next, when the control unit 21 determines in step S8 that the spray amount from the charged spray heads 32 has been changed by an operation by the operator or the like, the control unit 21 proceeds to step S9, where it selects the number of charged spray heads 32 to spray and changes the spray amount by selectively opening and closing the on-off valve 35 shown in Fig. 5. The change in the spray amount from the charged spray heads 32 may also be adjusted by changing the amount of fire extinguishant supplied from the fire extinguisher supply unit 16 to the charged spray heads 32.

[0138] Next, when the control unit 21 determines in step S10 that the charge amount of the charged water particles has been changed due to an operation by the operator or the like, it proceeds to step S11 and adjusts the voltage applied from the high-voltage power supply unit 18 to the charged spray head 32 to change the charge amount of the charged water particles.

[0139] Next, the control unit 21 proceeds to step S12, and if it determines that the abnormal current detection circuit 74 shown in Fig. 4 has detected an abnormal current due to poor insulation in any of the multiple charged spray heads 32, it proceeds to step S13 and performs application stop control to stop the application of high voltage to the charged spray head 32 in which the abnormal current was detected. Note that this application stop control may also stop the application of high voltage to all heads, including the charged spray head 32 in which the abnormal current was detected.

[0140] Next, the control unit 21 proceeds to step S14, and repeats the processing from step S5 until it determines that a release termination instruction is given by an operator or the like. When the release termination instruction is determined, it proceeds to step S15, and performs a predetermined release termination processing to stop the release of the charged water particle airflow 12, and then ends the processing.

[0141] [j. Modifications of the present invention] (fire engine) Although the above embodiment has been described as an example in which the charged water particle spraying system is mounted on a ladder fire truck, the system may be mounted on any suitable fire truck as long as the charged water particle discharger 10 can be brought close to a fire compartment located at a high point in a building from the outside. For example, in a fire truck for high-altitude work, the charged water particle discharger 10 may be provided on the high-altitude work platform, and in a fire truck with a boom, the charged water particle discharger 10 may be provided at the end of the boom. Furthermore, the charged water particle discharger 10 may be mounted on a self-propelled tracked vehicle, which may be remotely controlled to move to a fire compartment that is inaccessible to humans and inject an airflow of charged water particles.

[0142] (High voltage supply unit) In the above embodiment, a DC voltage is applied from the high-voltage power supply 18 between the induction electrode 60 and the water-side electrode 62 of the charged fine spray head 32, but other voltages such as a pulse voltage, a pulsating voltage, and an AC voltage may also be applied. Also, when applying a voltage between the induction electrode 60 and the water-side electrode 62 from the high-voltage power supply 18, voltage adjustment and voltage polarity switching are possible, but this is not limited to this and is optional; for example, the applied voltage and / or voltage polarity may be fixed.

[0143] (others) The present invention is not limited to the above-described embodiment, but includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values ​​shown in the above-described embodiment. [Explanation of symbols]

[0144] 10: Charged water particle emission part 12: Charged water particle airflow 14:Operation panel 16: Fire extinguishing agent supply section 18: High voltage power supply 20: Operation display section 21: Control unit 22: Water pipe 24: High voltage cable 24a: Voltage application cable 24b: Earth cable 26a~26f: Signal cables 28: Ventilation section 30: Charged water particle generator 31: Support ring 32: Electrostatic spray head 34: Axial fan 35: On-off valve 36: Fan motor 38: Protective cover 40: Stand 42: Rotating support part 44:Left and right adjustment section 46: Left and right rotation axis 48: Vertical adjustment section 50: Up and down rotation axis 52: Center of gravity 54: Body 56: Spray nozzle part 58: Electrode holding part 60: Induction electrode part 62: Water side electrode part 64: Water supply connection 66: High voltage variable circuit 68: Reversing circuit 72: Selection circuit 74: Abnormal current detection circuit 75, 77: Switch circuit 76: Current limiting resistor 78: Current detection resistor 80: Charge detector 82:Suction device 84: Sampling tube 84a: Suction port 85,86:Tube 85a: Heating part 88: Suction pump 90: Rod parts 92:Support part 94: Weight 95: Cylindrical electrode 96: Faraday cage 98a, 98b: Outer cylinder 100: Fine particle mixture 102: Insulation ring 104: Conductor case 105: Charge detection unit 106: Operational amplifier 108: Conductor 112: Circuit board 114: Judgment section 116: Ladder fire engine 118: Ladder 120: Basket 122: Building 124: Fire compartment

Claims

1. A charge detector for detecting the charge polarity of a particulate mixture, a conductive cylindrical electrode formed in a cylindrical shape having a hollow portion and allowing the particulate gas mixture to pass from one end side to the other end side of the hollow portion; a Faraday cage having a conductive outer cylinder that is electrically insulated from the cylindrical electrode, covers the outer periphery of the cylindrical electrode, and is grounded; a charge detection unit that converts induced charges of the same polarity as the charged polarity of the particulate mixture attracted to the outer periphery of the cylindrical electrode by the charge of the particulate mixture into a voltage signal and outputs the voltage signal; a determination unit that determines the charge polarity of the particulate mixture based on the voltage signal output from the charge detection unit; Equipped with The charge detector is characterized in that the length of the eaves portion of the outer cylindrical body constituting the Faraday cage, which is installed to cover the outer periphery of the cylindrical electrode, at one end and the other end of the outer cylindrical body, which extends beyond the one end and the other end of the cylindrical electrode, is more than twice the inner diameter of the cylindrical electrode.

2. 2. The charge detector according to claim 1, The charge detector is characterized in that the determination unit determines the charge polarity of the particulate mixture based on an integration result of a voltage signal output from the charge detection unit.

3. 3. The charge detector according to claim 2, The charge detector is characterized in that the judgment unit judges the charge polarity of the particulate mixture to be negative when the integral value, which is the integration result, decreases over time, and judges the charge polarity of the particulate mixture to be positive when the integral value increases over time.

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