Charged water particle dispersal system

Abstract

This ensures a high level of safety even if an insulation failure occurs in the electrostatic spray head. [Solution] The charged water particle spraying system comprises a plurality of charged spray heads 32, each having an induction electrode section 60 and a water-side electrode section 62, a high-voltage power supply unit 18, and an abnormal current detection circuit 74. The induction electrode section 60 is connected to the high-voltage power supply unit 18 via individually provided switch circuits 75, and the water-side electrode section 62 is connected to the high-voltage power supply unit 18 via a common switch circuit 77. When the abnormal current detection circuit 74 detects a current abnormality, if the application of voltage to the charged spray head 32 in which the current abnormality was detected is to be stopped, the switch circuit 75 corresponding to that charged spray head 32 is turned off to disconnect the induction electrode section 60 from the high-voltage power supply unit 18. If the application of voltage to all charged spray heads 32 is to be stopped, all switch circuits 75 and switch circuits 77 are turned off to disconnect the induction electrode section 60 and the water-side electrode section 62 from the high-voltage power supply unit 18.

Description

Technical Field

[0001] The present invention relates to a charged water particle spraying system that sprays charged water particles from the tip of a ladder of a ladder fire truck or the like onto a spraying target area such as a building where a fire has occurred to extinguish the fire.

Background Art

[0002] Conventionally, a charged water particle spraying system that sprays charged water particles onto a spraying target area such as a building where a fire has occurred to extinguish the fire is known, and it is expected to be able to extinguish the fire efficiently with a small amount of water and reduce water damage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in conventional charged water particle spraying systems, charged water particles sprayed from a charged spray head are dispersed into the area where a fire is occurring to suppress and extinguish the fire, and also to eliminate smoke generated in the area. For example, if negatively charged charged water particles are sprayed from a charged spray head, and the particulate mixture containing smoke particles etc. generated in the area to be sprayed is positively charged, it is thought that the particulate particles (smoke particles) contained in the particulate mixture will be attracted to and captured by the charged water particles due to electrostatic force, thereby eliminating smoke more effectively. Furthermore, if positively charged charged water particles are sprayed from a charged spray head, and the particulate mixture is negatively charged, it is thought that the particulate particles (smoke particles) contained in the particulate mixture will be attracted to and captured by the charged water particles due to electrostatic force, thereby eliminating smoke more effectively.

[0005] However, whether the particulate mixture generated in the area to be sprayed is negatively or positively charged varies depending on the type of combustion material and the nature of the fire, and in some cases, sufficient smoke suppression performance cannot be obtained unless the charge polarity of the particulate mixture is opposite to that of the charged water particles.

[0006] Therefore, operators must spray charged water particles, set to either positive or negative polarity, and observe the results. If sufficient fire and smoke extinguishing is not achieved, they must switch the polarity of the charged water particles to the opposite polarity and spray again. This may result in insufficient fire and smoke extinguishing performance being obtained from the start of spraying, making rapid fire and smoke extinguishing operations impossible.

[0007] Furthermore, since the charged spray head has a high voltage applied between its two electrodes to charge the water particles for spraying onto the target area, if an insulation failure occurs between the electrodes, it could endanger the operator working near the charged spray head, making it necessary to ensure sufficient safety for the operator.

[0008] The present invention aims to provide a charged water particle spraying system that can ensure high fire extinguishing and smoke suppression performance from the very beginning of spraying charged water particles onto a target area.

[0009] Furthermore, the present invention aims to provide a charged water particle spraying system that can ensure high safety even if an insulation failure occurs in the charged spray head. [Means for solving the problem]

[0010] (Charged water particle dispersal system) The present invention relates to a charged water particle dispersal system for dispersing charged water particles onto a target area, Multiple charged spray heads that generate and spray charged water particles for spraying onto a target area by charging water particles by applying a predetermined voltage between two electrodes, A power supply unit that applies a predetermined voltage between two electrodes of multiple charged spray heads, An abnormal current detection unit for each of the multiple charged spray heads detects an abnormal current flowing between two electrodes, Equipped with, One electrode of each of the multiple charged spray heads is connected to the power supply unit via a first switch unit, which is individually provided for each of the multiple charged spray heads. The other electrode of each of the multiple electrostatic spray heads is connected to the power supply unit via a second switch unit that is common to all of the multiple electrostatic spray heads. When the abnormal current detection unit detects a current abnormality in at least one of the multiple charged spray heads and stops applying voltage to the charged spray head in which the current abnormality was detected, the first switch unit corresponding to the charged spray head in which the current abnormality was detected is turned off, and one electrode of the charged spray head in which the current abnormality was detected is disconnected from the power supply unit. The abnormal current detection unit detects a current abnormality in at least one of the multiple charged spray heads and, when it decides to stop applying voltage to all charged spray heads, it is characterized by turning off all first and second switch units to disconnect the two electrodes of all charged spray heads from the power supply unit. [Effects of the Invention]

[0011] (Effects of the charged water particle dispersal system) The inventors of the present invention have found that for fires involving the combustion of liquid fuels containing hydrocarbons, oils and fats, synthetic resins, etc. (oil fires), there is no difference in smoke extinguishing performance whether the charged polarity of the water particles being sprayed is negative or positive. However, for fires involving the combustion of wood and paper containing cellulose (wood fires), higher fire extinguishing and smoke extinguishing performance can be obtained by using water particles with a negative charged polarity.

[0012] Therefore, it is preferable to set the initial charge polarity of charged water particles to negative polarity. In the charged water particle dispersal system of the present invention, the charged water particles to be dispersed to the target area are initially set to be negatively charged. As a result, from the start of dispersal of charged water particles until the charge polarity of the particulate mixture is detected by the charge detector, charged water particles that are negatively charged by the initial setting are dispersed. This makes it possible to obtain high smoke extinguishing performance from the very beginning of dispersal of charged water particles, regardless of the type of fire, such as wood fires or oil fires.

[0013] (Effects of detecting and controlling abnormal currents) Furthermore, for each of the multiple charged spray heads that generate charged water particles for spraying onto a target area by charging water particles by applying a predetermined voltage between two electrodes, a current detection unit is used to detect abnormal currents flowing between the two electrodes, for example, due to insulation abnormalities. If an abnormal current is detected in at least one of the multiple charged spray heads, the application of high voltage to the charged spray head that detected the abnormal current or to all charged spray heads is stopped, thereby preventing danger to the operator and ensuring a high level of safety. [Brief explanation of the drawing]

[0014] [Figure 1] This is an explanatory diagram showing an embodiment of the charged water particle dispersal system of the present invention. [Figure 2] Figure 1 is an explanatory diagram showing an embodiment of the charged water particle discharge unit. [Figure 3] It is an explanatory diagram showing an embodiment of a charged spray head provided in the charged water particle discharge part of FIG. 2. [Figure 4] It is an explanatory diagram showing an embodiment of the high-voltage power supply part of FIG. 1 together with the charged spray head. [Figure 5] It is an explanatory diagram showing an embodiment of the fire extinguishing agent supply part of FIG. 1 together with the charged spray head. [Figure 6] It is an explanatory diagram showing the suction device of FIG. 1. [Figure 7] It is an explanatory diagram showing an embodiment of the charge detector of FIG. 1. [Figure 8] It is an explanatory diagram showing the charge detection operation by the charge detection part of the charge detector. [Figure 9] It is an explanatory diagram showing the fire extinguishing activity by a ladder fire truck equipped with the charged water particle spraying system of the present invention. [Figure 10] It is a flowchart showing the control operation of the charged water particle spraying system of the present invention.

Embodiments for Carrying out the Invention

[0015] Hereinafter, embodiments of the charged water particle spraying system according to the present invention will be described in detail based on the drawings. Note that the present invention is not limited by the following embodiments.

[0016] [Basic Concepts of Embodiments] First, the basic concepts of the embodiments will be described. The embodiments generally relate to a charged water particle spraying system for spraying charged water particles into a spraying target area, and as an example, it is provided on a moving body such as a fire truck.

[0017] Here, the "charged water particle spraying system" includes a plurality of charged spray heads, a charge detector, a suction device, and a control unit, and includes the concept of charged water particle spraying equipment and charged water particle spraying devices for constructing the charged water particle spraying system. Further, the "spraying target area" is a concept including a source of smoke or the like, a fire source, or a place or space where these exist, or a diffusion area of smoke or the like.

[0018] A "charged spray head" is a device that sprays charged water particles to a target area, and in this embodiment, it is equipped with multiple charged spray heads.

[0019] Furthermore, "charged water particles" refer to water particles contained in the spray stream of fire extinguishing agent sprayed from a charged spray head that have been charged. For example, the water particles are charged by applying a predetermined voltage between the two electrodes of the charged spray head. More specifically, they are water particles charged by an inductive charging method, in which they are passed through a high electric field generated by a predetermined high voltage applied to the charged spray head from a high-voltage power supply.

[0020] Here, the charged spray head is equipped with two electrodes: a water-side electrode as the first electrode and an induction electrode as the second electrode. A predetermined voltage is applied between these two electrodes to charge the water particles. More specifically, the water-side electrode is set to a reference potential (earth potential, 0V), and the potential of the induction electrode is set to a potential difference relative to the reference potential of the water-side electrode that allows the water particles to be charged. A predetermined voltage is then applied between the water-side electrode and the induction electrode to charge the water particles.

[0021] Furthermore, "dispersing charged water particles to the target area" means that the method of dispersal is arbitrary as long as the charged water particles sprayed from the charged spray head can be moved to the target area and dispersed. For example, an airflow may be generated toward the target area, and a charged water particle airflow containing the charged water particles sprayed from the charged spray head may be released into this airflow to move and disperse the charged water particles to the target area. Alternatively, spraying the charged water particles from the charged spray head may also constitute dispersal to the target area.

[0022] Furthermore, a "charge detector" is used to detect the charge polarity of particulate mixtures generated in the area to be sprayed. Here, "particulate mixture" refers to a gas containing particulate matter, including smoke particles and monodisperse particles generated by fire, as well as combustion product gases such as carbon dioxide and carbon monoxide. "Charging of particulate mixture" means "charging of particles contained in the particulate mixture." Furthermore, "particulate mixture generated in the target area" means "particulate mixture generated in the target area," and is a concept that includes "generating from smoke sources and fire sources present in the target area," and therefore "being included in the location or spatial area where the smoke sources and fire sources are located, as well as the smoke diffusion area, etc."

[0023] Furthermore, the "control unit" is configured to initially set the charged water particles to be negatively charged, and when the charge detector detects the negative charge of the particulate mixture, it controls the switching of the charged water particles' charge from the initially set negative polarity to positive polarity.

[0024] Furthermore, the "charged water particle dispersal system" may include an abnormal current detection unit that detects abnormal currents flowing between two electrodes for each of the multiple charged spray heads.

[0025] When the "charged water particle spraying system" is equipped with an "abnormal current detection unit," the "control unit" will, when the abnormal current detection unit detects a current abnormality in at least one of the multiple charged spray heads, stop applying voltage to the charged spray head where the current abnormality was detected, or to all charged spray heads, thereby preventing danger to the operator due to insulation abnormalities in the charged spray heads and ensuring a high level of safety. Here, insulation abnormality refers to an abnormality in electrical insulation, and is a concept that includes insulation degradation, insulation failure, dielectric breakdown, short circuit, etc.

[0026] The following describes a specific embodiment. In the specific embodiment shown below, the details will be explained in the case where the "area to be sprayed" is a "fire compartment of a building" and the "multiple charged spray heads and charge detectors" are installed at the tip of the ladder of a ladder fire truck.

[0027] [Specific details of the embodiment] The specific details of the embodiment will be explained as follows: a. Overview of the charged water particle dispersal system b. Charged water particle release section b1.Blower section b2. Charged water particle generation section b3. Electrostatic spray head b4. Release direction adjustment part c. High-voltage power supply unit c1. Circuit configuration of the electrolyzed water particle generation unit c2. High-voltage variable circuit c3. Polarity reversal circuit c4. Application of high voltage c5. Abnormal current detection circuit d. Fire extinguishing agent supply unit e. Control of switching the charge polarity 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 Unit e5. Switching control of the charge polarity of charged water particles f. Types of fire and the charge polarity of water particles f1. Charge polarity of water particles against wood fires f2. Charge polarity of water particles against oil fires f3. Initial setting of water particle charge polarity g.Operation panel h. Ladder fire truck equipped with a charged water particle dispersal system i. Control operation of the charged water particle dispersal system j. Modifications of the present invention

[0028] [a. Overview of the charged water particle dispersal system] The charged water particle spraying system of this embodiment is mounted on a fire fighting vehicle 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 Figure 1, it comprises 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 equipped with an operation display unit 20 and a control unit 21.

[0029] The charged water particle discharge unit 10 comprises a blower unit 28 and a charged water particle generation unit 30, and is rotatably mounted on a frame 40 in the vertical and horizontal directions. It is connected to a water supply pipe 22 from the fire extinguishing agent supply unit 16, and high-voltage cables 24, signal cables 26e and 26f from the high-voltage power supply unit 18, as well as signal cables 26a and 26d from the control unit 21 of the control panel 14. Here, signal cable 26a is connected to the discharge direction adjustment unit of the blower unit 28, and signal cables 26d, 26e and 26f are connected to on-off valves, switch circuits and current detection resistors provided for each of the multiple charged spray heads located in the charged water particle generation unit 30.

[0030] The charge detector 80 is located on the side of the charged water particle discharge unit 10 and detects the charge polarity of fine particles contained in the fine particle mixture drawn in by the suction device 82. A signal cable 26c from the control unit 21 of the control panel 14 is connected to it.

[0031] The suction device 82 is located on the side of the charged water particle discharge unit 10 and is used to draw in a mixture of particulate matter containing fire smoke particles generated 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 control 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 by reference numerals in Figure 1, will be described later.

[0032] In the explanation of Figure 1, the X, Y, and Z directions are mutually orthogonal. Specifically, when viewing the front of the charged water particle generation unit 30, which is positioned on the non-rotating frame 40, the X direction is the left-right direction (not shown in Figure 1), the Y direction is the up-down direction, and the Z direction is the front-back direction. Furthermore, in the X direction, the +X side is the right side and the -X side is the left side; in the Y direction, the +Y side is the upper side and the -Y side is the lower side; and in the Z direction, the +Z side is the front side and the -Z side is the rear side. This is the same in Figures 2 and 6, which represent embodiments of the present invention.

[0033] [b. Charged water particle release section] The charged water particle discharge unit 10 will now be described in more detail. The charged water particle discharge unit 10 disperses charged water particles toward the fire compartment of a building containing the target of fire extinguishing or fire prevention by discharging a charged water particle airflow 12 containing charged water particles. Its configuration and structure are arbitrary, but for example, it includes a blower unit 28 and a charged water particle generation unit 30.

[0034] The blower unit 28 generates an airflow toward the fire compartment. Multiple charged spray heads provided in the charged water particle generation unit 30, located at the outlet of the blower unit 28, spray and incorporate charged water particles into the airflow from the blower unit 28, and the charged water particle airflow 12 containing the charged water particles is released toward the fire compartment. The charged water particle discharge unit 10 is installed, for example, at the tip of the ladder of a ladder fire truck, and the charged water particle airflow 12 is released from the outside of a building where a fire has occurred, such as a building, through an exterior wall opening such as a window, into the fire compartment to extinguish the fire.

[0035] Figure 2 shows the charged water particle emission unit 10 from Figure 1 in more detail. Figure 2(A) shows a rear view, Figure 2(B) shows a side view, and Figure 2(C) shows a front view.

[0036] (b1.Blower part) The air blower unit 28 will now be described in more detail. The air blower unit 28 has a cavity with openings at the front and rear, and for example, an axial flow fan 34 driven by a fan motor 36 is arranged inside. The rotation of the axial flow fan 34 pressurizes the air drawn in from the rear opening and releases the airflow from the front opening. The airflow volume released from the air blower unit 28 can be arbitrary, but for example, the maximum airflow volume is set to about 400 m³ / min. Furthermore, the airflow volume can be changed as needed by changing the rotation speed of the axial flow fan 34 using the fan motor 36.

[0037] When the charged water particle discharge unit 10 is installed at the tip of the ladder of a ladder fire truck, it is possible to bring the charged water particle discharge unit 10 within a few meters of the fire compartment of the building. Therefore, the airflow rate of the blower unit 28 is set so that the distance to which the charged water particle airflow 12 reaches the fire compartment is, for example, about 10 meters. In addition, a protective cover 38 made of a multi-ring or wire mesh is attached to the rear opening of the blower unit 28.

[0038] (b2. Charged water particle generation section) The charged water particle generation unit 30 will now be described in more detail. The charged water particle generation unit 30 is located on the front opening side of the air blower unit 28. As shown in Figure 2(C), when viewed from the front of the charged water particle discharge unit 10, for example, 10 charged spray heads 32 are arranged in a ring shape inside the support ring 31. Here, the spray axis of each charged spray head 32 is positioned to intersect with the discharge axis 25 of the charged water particle airflow 12, and as shown in Figure 2(B), when viewed from the left side of the charged water particle discharge unit 10, the spray axes of each charged spray head 32 are positioned to intersect at point P in front of the discharge axis 25.

[0039] 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 ensures the sprayed charged water particles are well contained in the airflow, taking into consideration the ejection velocity and ejection spread angle of the charged water particles from the charged spray head 32, the wind speed of the airflow from the blower unit 28, etc. As an example, it is a predetermined angle in the range of 45° to 90°, for example, 60°.

[0040] (b3. Electrostatic spray head) Next, the charged spray head 32 provided in the charged water particle generation unit 30 in Figure 2 will be described in more detail. Figure 3 shows the charged spray head 32 removed from the surface, with Figure 3(A) showing a perspective view from the spraying side and Figure 3(B) showing a cross-sectional view from the side.

[0041] As shown in Figure 3, the charged spray head 32 sprays and incorporates charged water particles into the airflow from the blower unit 28. Its configuration and structure are arbitrary, but as an example, it consists of a body 54, a spray nozzle unit 56, an electrode holder 58, an induction electrode unit 60, a water-side electrode unit 62, and a water supply connection unit 64. The body 54, spray nozzle unit 56, electrode holder 58, and water supply connection unit 64 are made of insulating material.

[0042] A through hole is formed inside the body 54 in the direction of the spray axis 55, and a conductive water-side electrode section 62 is fitted from the spray side, and a water supply connection section 64 is fitted above it, and an earth cable is connected from the outside to the electrode connection section 62a of the water-side electrode section 62. Pressurized fire extinguishing water, for example, is supplied to the water supply connection section 64 as a fire extinguishing agent. A spray nozzle section 56 is provided on the spray side of the water-side electrode section 62, and sprays water particles with an average particle diameter of, for example, 100 to 300 μm.

[0043] A ring-shaped induction electrode section 60 is positioned in the open space on the spraying side of the spray nozzle section 56 by an electrode holding section 58. The configuration and structure of the induction electrode section 60 are arbitrary, but for example, it is formed by insulating a conductive electrode core material. An external voltage application cable is connected to the cable connection section 60a of the induction electrode section 60.

[0044] Between the induction electrode section 60 and the water-side electrode section 62, a predetermined voltage (e.g., a DC voltage of 10kV) is applied from the high-voltage power supply section 18 shown in Figure 1, adjusted within a predetermined adjustment range (e.g., 0.5kV to 20kV) within a voltage range capable of charging water particles. This applied voltage creates a predetermined external electric field around the ring portion of the induction electrode section 60, and water particles sprayed from the spray nozzle section 56 are charged by the induction charging method as they pass through the ring portion of the induction electrode section 60.

[0045] Here, the predetermined adjustment range (i.e., the adjustable predetermined range) may include a voltage range in which water particles cannot be charged, and it is sufficient that it can be adjusted to a predetermined voltage in which water particles can be charged. The polarity (positive / negative) of the applied voltage is switched by the high-voltage power supply unit 18.

[0046] The charging of water particles by the charged spray head 32 can be achieved by, for example, applying a predetermined DC voltage such that the potential of the induction electrode 60 becomes positive, with the water-side electrode 62 as the reference potential (earth potential, 0V). This causes the water particles sprayed from the spray nozzle 56 to be negatively charged. Alternatively, applying a predetermined DC voltage such that the potential of the induction electrode 60 becomes negative, with the water-side electrode 62 as the reference potential (earth potential, 0V), causes the water particles sprayed from the spray nozzle 56 to be positively charged. Furthermore, by setting the absolute value of the voltage applied between the induction electrode 60 and the water-side electrode 62 to a range of, for example, 0.5kV to 20kV, the occurrence of spark discharge is prevented, and a spray stream of charged water particles is generated while ensuring safety.

[0047] The configuration and structure of the charged spray head 32 are arbitrary and not limited to Figure 3. Any suitable structure or known structure that can generate water particles and charge the generated water particles to spray charged water particles can be adopted.

[0048] (b4. Release direction adjustment part) The discharge direction adjustment section provided in the charged water particle discharge section 10 will be described in more detail. The discharge direction adjustment section adjusts the discharge direction of the charged water particle airflow 12 from the charged water particle discharge section 10. Its configuration and structure are arbitrary, but as an example, as shown in Figure 2, a left-right direction adjustment section 44 and an up-down direction adjustment section 48 are provided.

[0049] The air blower 28 of the charged water particle discharge unit 10 is pivotally supported on the frame 40 by a pivot support 42 so as to be able to rotate left and right with respect to a left and right pivot shaft 46 as the pivot axis, and is also pivotally supported so as to be able to rotate up and down with respect to a right and down pivot shaft 50 as the pivot axis. In addition, a left and right direction adjustment unit 44 is located on the lower side of the frame 40. The left and right direction adjustment unit 44 is, for example, motor-driven, and by pivoting the pivot support 42 so that the left and right pivot shafts 46 are positioned on the drive shaft, the charged water particle discharge unit 10 can be rotated left and right with respect to the left and right pivot shafts 46 as the pivot axis, thereby adjusting the left and right discharge direction of the charged water particle airflow 12.

[0050] Furthermore, a vertical adjustment unit 48 is positioned on the right side of the rotation support unit 42 where the vertical rotation shaft 50 is located. The vertical adjustment unit 48 is, for example, motor-driven, and by pivoting 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 vertically using the vertical rotation shaft 50 as the axis of rotation, thereby allowing adjustment of the vertical discharge direction of the charged water particle airflow 12.

[0051] Here, the left-right pivot axis 46 and the up-down pivot axis 50 are adjusted to a predetermined position in front of (on the discharge side of) the center of gravity 52 of the charged water particle discharge unit 10. As a result, even when subjected to the recoil of the charged water particle airflow 12 discharged by the charged water particle discharge unit 10, the discharge direction remains stable, and the operator can easily adjust it to the desired discharge direction. Furthermore, in cases where the charged water particle discharge unit 10 is installed in the basket at the tip of the ladder of a ladder fire truck, even when the basket tilts, the stability of the discharge direction of the charged water particle airflow 12 from the charged water particle discharge unit 10 is high, preventing the discharge direction of the charged water particle airflow 12 from being directed in an unexpected direction, thus enabling safe operation.

[0052] [c. High-voltage power supply section] The high-voltage power supply unit 18 will now be described in more detail. The high-voltage power supply unit 18 supplies a high voltage to the charged water particle discharge unit 10 via a high-voltage cable 24 to generate charged water particles. Its configuration and functions are arbitrary, but for example, as shown in Figure 4, it includes a high-voltage variable circuit 66 for adjusting the supplied voltage, a polarity reversal circuit 68 for switching the polarity of the supplied voltage, an abnormal current detection circuit 74 that detects abnormal currents flowing between the induction electrode section 60 and the water-side electrode section 62 of the charged spray head 32 and functions as an abnormal current detection unit, and a selection circuit 72 for switching between applying and stopping the voltage to the charged spray head 32. Also in Figure 4, the high-voltage cable 24 has a voltage application cable 24a connected to the induction electrode section 60 side and a ground cable 24b connected to the water-side electrode section 62 side.

[0053] (c1. Circuit configuration of the charged water particle generation unit) The circuit configuration of the charged water particle generation unit 30, which is connected to the high-voltage power supply unit 18 by a high-voltage cable 24, will be described in more detail. Figure 4 shows the circuit configuration of the charged water particle generation unit 30, which is equipped with a high-voltage power supply unit 18 and a plurality of charged spray heads 32. Each charged spray head 32 is equipped with an induction electrode section 60 and a water-side electrode section 62. The voltage application cable 24a from the high-voltage power supply unit 18 branches out for each charged spray head 32 and is connected to the induction electrode section 60 of each charged spray head 32 via a switch circuit 75 and a current limiting resistor 76. In addition, the water-side electrode section 62 of each charged spray head 32 is commonly connected via a current detection resistor 78, to which the ground cable 24b from the high-voltage power supply unit 18 is connected via a switch circuit 77.

[0054] Under normal conditions, switch circuits 75 and 77 are ON, and the high-voltage power supply unit 18 applies a high voltage between the induction electrode unit 60 and the water-side electrode unit 62, thereby charging the water particles sprayed from the charged spray head 32. Here, the voltage application cable 24a and the ground cable 24b are high-insulation, voltage-resistant cables. However, when applying a DC voltage, the positive electrode cable is a voltage-resistant cable, and the negative electrode cable can be a normal low-voltage cable.

[0055] (c2. High-voltage variable circuit) The high-voltage variable circuit 66 will now be explained in more detail. The high-voltage variable circuit 66 adjusts the voltage applied between the induction electrode section 60 and the water-side electrode section 62 in accordance with a control signal from the control section 21 of the control panel 14. This allows the charged water particle airflow containing charged water particles with an appropriate charge amount for fire extinguishing and smoke suppression to be released from the charged spray head 32 into the fire compartment. Furthermore, by reducing the absolute value of the applied voltage, the amount of charge in the charged water particles is reduced, which makes it possible to prevent discharge accidents that may occur due to an increase in the amount of charge caused by the charged water particles on fire extinguishing targets or fire prevention targets that are easily charged.

[0056] (c3. Polarity reversal circuit) The polarity reversal circuit 68 will now be explained in more detail. The polarity reversal circuit 68 switches the polarity of the voltage applied between the induction electrode section 60 and the water-side electrode section 62 in response to a control signal from the control section 21 of the control panel 14. This switches the charge polarity of the charged water particles sprayed from the charged spray head 32 to positive or negative polarity, allowing a charged water particle airflow containing charged water particles with a charge polarity suitable for fire extinguishing and smoke extinguishing to be released into the fire compartment. For example, by releasing a charged water particle airflow containing charged water particles with the opposite polarity to the charge polarity of the particulate mixture generated in the fire compartment, higher fire extinguishing and smoke extinguishing performance can be expected.

[0057] (c4. Application of high voltage) The case where a high voltage is applied from the high-voltage power supply unit 18 between the induction electrode unit 60 and the water-side electrode unit 62 of the charged spray head 32 will be explained in more detail, using the case where a DC voltage is applied as an example.

[0058] The high-voltage variable circuit 66 adjusts the voltage output from the high-voltage variable circuit 66 to a predetermined DC voltage in response to a control signal from the control unit 21 of the control panel 14. "Adjusting to a predetermined DC voltage" means adjusting to a DC voltage capable of charging water particles, for example, by adjusting to a DC voltage selected from the voltage range of 0.5kV to 20kV (+0.5kV to +20kV or -0.5kV to -20kV), which is the voltage range capable of charging water particles.

[0059] The polarity reversal circuit 68 determines whether or not to switch the polarity of a predetermined 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 control panel 14, and adjusts the polarity of the DC voltage applied between the induction electrode section 60 and the water-side electrode section 62.

[0060] For example, if the high-voltage variable circuit 66 adjusts a predetermined DC voltage to a DC voltage of +10kV (positive DC voltage), and the polarity is not switched in the polarity reversal circuit 68, the potential of the induction electrode section 60 becomes +10kV with the water-side electrode section 62 as the reference potential (earth potential, 0V). A DC voltage of +10kV (positive DC voltage) is applied between the induction electrode section 60 and the water-side electrode section 62, resulting in the induction electrode section 60 having a higher potential than the water-side electrode section 62. As a result, the water particles sprayed from the charged spray head 32 become negatively charged.

[0061] On the other hand, when the high-voltage variable circuit 66 adjusts a predetermined DC voltage to a DC voltage of +10kV (positive DC voltage) and the polarity is switched in the polarity reversal circuit 68, the water-side electrode section 62 is set to a reference potential (earth potential, 0V), and the potential of the induction electrode section 60 becomes -10kV. A DC voltage of -10kV (negative DC voltage) is applied between the induction electrode section 60 and the water-side electrode section 62, resulting in the induction electrode section 60 having a lower potential than the water-side electrode section 62. As a result, the water particles sprayed from the charged spray head 32 become positively charged.

[0062] (c5. Abnormal current detection circuit) The abnormal current detection circuit 74, which functions as an abnormal current detection unit, will now be described in more detail. The abnormal current detection circuit 74 detects abnormal currents flowing between the induction electrode section 60 and the water-side electrode section 62 due to insulation abnormalities in each of the multiple charged spray heads 32. Here, insulation abnormality refers to an abnormality in electrical insulation, and is a concept that includes insulation degradation, insulation failure, dielectric breakdown, short circuit, etc.

[0063] A series circuit of a current limiting resistor 76, an induction electrode section 60, a water-side electrode section 62, and a current detection resistor 78 is provided for each branch line of the voltage application cable 24a that branches off for each charged spray head 32. A 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 via separate signal lines, and an earth cable 24b is connected to the abnormal current detection circuit 74. As a result, the voltage across each current detection resistor 78 is input to the abnormal current detection circuit 74 as a current detection voltage signal.

[0064] Here, the resistance value of the current limiting resistor 76 is set to a predetermined resistance value in the range of 1 to 10 MΩ, and the resistance value of the current detection resistor 78 is arbitrary, but is set to a resistance value that is sufficiently lower than the resistance value of the current limiting resistor 76, for example, a predetermined resistance value in the range of 1 to 10 kΩ. Specifically, the resistance value of the current detection resistor 78 is determined so that the voltage across the current detection resistor 78 due to the abnormal current flowing due to an insulation abnormality in the charged spray head 32 is below a predetermined low voltage, for example, 10 V or less. That is, the current flowing through the current detection resistor 78 is at its maximum when the induction electrode part 60 and the water side electrode part 62 of the charged spray head 32 are short-circuited, and the voltage across the current detection resistor 78 is also at its maximum voltage. Therefore, the resistance value of the current detection resistor 78 is determined so that this maximum voltage is, for example, 10 V or less.

[0065] Furthermore, since the abnormal current detection circuit 74 has separate signal lines connecting the signal cable 26f to the water-side electrode portion 62 of each current detection resistor 78, it is possible to detect abnormal currents due to insulation failure for each charged spray head 32. In this embodiment, 10 charged spray heads 32 are provided (see Figure 2), and one of the abnormal current detection signals E1 to E10 is output to the control unit 21 in accordance with the charged spray head 32 in which an abnormal current is detected. The configuration and function of the comparators are arbitrary, but for example, a number of comparators corresponding to the number of charged spray heads 32 can be provided. The comparators receive a current detection voltage signal, which is the voltage across the current detection resistor 78 provided on the side of the corresponding charged spray head 32, and when the current detection voltage signal is above or above a predetermined threshold voltage or exceeds the threshold voltage, they detect an abnormal current and output an abnormal current detection signal that rises from L level to H level.

[0066] Furthermore, the type and configuration of the comparator used in this operation are arbitrary, but for example, a Schmitt trigger circuit is used. The Schmitt trigger circuit outputs an abnormal current detection signal by raising its output 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 dropping its output from H level to L level when the current detection voltage signal falls below a second threshold voltage which is lower than the first threshold voltage. This so-called hysteresis characteristic enables stable output of an abnormal current detection signal in response to fluctuations in the current detection voltage signal.

[0067] As described above, the current detection resistor 78 and the abnormal current detection circuit 74 are provided on the reference potential side, and the resistance value of the current detection resistor 78 is sufficiently lower than the resistance value of the current limiting resistor 76. By configuring the circuit so that the voltage across the current detection resistor 78 is low due to the abnormal current flowing due to an insulation abnormality in the charged spray head 32, special high-voltage circuit components are not required for the abnormal current detection circuit 74. Furthermore, since no high voltage is applied to the abnormal current detection circuit 74, there is no need for an insulation structure that can withstand high voltages, thus simplifying the insulation structure. This allows for easy and convenient detection of the charged spray head 32 with an insulation abnormality from among multiple charged spray heads 32, without compromising safety.

[0068] The control unit 21, which receives abnormal current detection signals E1 to E10 from the abnormal current detection circuit 74, determines the detection of an abnormal current in the charged spray head 32 corresponding to the input abnormal current detection signal when any of the abnormal current detection signals E1 to E10 is input, and performs control to stop the application of high voltage to the charged spray head 32 in which an 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. Furthermore, the selection circuit 72 receives control signals from the control unit 21 to turn the switch circuits on and off, and the signal cable 26e from the selection circuit 72 is connected to each switch circuit 75 by separate signal lines.

[0069] The selection circuit 72, in response to a control signal from the control unit 21, outputs an off-operation signal to the switch circuit 75 corresponding to the charged spray head 32 where an abnormal current has been detected, thereby turning it off and stopping the application of high voltage to the charged spray head 32 where an abnormal current has been detected, thus ensuring the safety of the operator.

[0070] Furthermore, if the control unit 21 receives any of the abnormal current detection signals E1 to E10 and detects the presence of an abnormal current in any of the charged spray heads 32, it may stop applying voltage to all 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 switch circuit 77 is connected to the selector circuit 72 by a signal cable 26e separate from the switch circuit 75. In this case, the selector circuit 72 stops applying high voltage to all charged spray heads 32 by outputting an off-operation signal to all switch circuits 75 and 77 in response to a control signal from the control unit 21, thereby turning them off.

[0071] [d. Fire extinguishing agent supply unit] The fire extinguishing agent supply unit 16 shown in Figure 1 will be described in more detail. The fire extinguishing agent supply unit 16 supplies, for example, fire extinguishing water as a fire extinguishing agent to the charged water particle discharge unit 10. Its configuration and structure are arbitrary, but as an example, since the charged water particle spraying system of this embodiment is mounted on a ladder fire truck, the fire extinguishing agent supply unit 16 consists of a pressurized water supply device or pressurized water supply equipment including a fire pump installed on the fire truck. In this case, the water source includes a water tank mounted on the fire truck and a fire hydrant to which a hose is connected. Furthermore, the fire extinguishing agent supply unit 16 operates by the operation of the discharge start or discharge stop operation on the control panel 14 to supply and stop fire extinguishing water.

[0072] Furthermore, the water supply pipe 22 from the fire extinguishing agent supply unit 16 is branched at the connection point of the charged water particle discharge unit 10 and 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. In addition, when the charged water particle spraying system is mounted on a ladder fire truck, the water supply pipe 22 is equipped with a known telescopic piping structure that extends and retracts according to the length of the ladder in the ladder portion of the fire truck.

[0073] Each on-off valve 35, provided in conjunction with the charged spray head 32, is connected to the control unit 21 by separate signal cables 26d and is individually opened and closed according to the control signal from the control unit 21. The control unit 21 controls the amount of charged water particles sprayed from the multiple charged spray heads 32, for example, based on the operator's actions. The method of adjusting the spray amount is arbitrary, but for example, the spray amount from the charged spray heads 32 is adjusted by changing the number of on-off valves 35 that are opened, or by changing the amount of fire extinguishing water supplied from the fire extinguishing agent supply unit 16.

[0074] [e. Control of switching the charge polarity of charged water particles] The control of the charge polarity switching of charged water particles contained in the charged water particle airflow released from the charged water particle discharge unit 10 will be explained in more detail. The control of the charge polarity switching of charged water particles contained in the charged water particle airflow released from the charged water particle discharge 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 Figure 1.

[0075] (e1. Suction device) The suction device 82 will now be described in more detail. The suction device 82 draws in a mixture of particulate matter containing smoke particles from the fire from the fire compartment side toward the charge detector 80. Its structure and function are arbitrary, but for example, as shown in Figure 6, it consists of a sampling tube 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 holding devices that movably hold the sampling tube 84 and tube 85.

[0076] (e1-1. Sampling tube) The sampling tube 84 will now be explained in more detail. The sampling tube 84 is a hollow component that draws in a mixture of particulate matter from the fire compartment of a building through a suction port 84a at its tip. 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. Furthermore, it is insulated from the supporting rod member 90 and the connected tube 85 so that it is not grounded. The diameter and length of the sampling tube 84 are arbitrary, but to allow the operator to maintain a safe distance from the fire compartment and draw in the mixture of particulate matter from the suction port 84a at the tip of the sampling tube 84, the diameter is set to about 2 to 3 cm and the length to about 1 to 2 m.

[0077] (e1-2. Tubes) Let me explain tube 85 in more detail. Tube 85 is a flexible hollow member that connects the sampling tube 84 to the inlet of the charge detector 80. Its structure and material are arbitrary, but examples include flexible synthetic resin or rubber tubes, hoses, etc.

[0078] Furthermore, a heating section 85a is provided at one end of the tube 85 that is connected to the inlet of the charge detector 80. The heating section 85a heats the space inside the tube 85 through which the particulate mixture drawn in from the sampling tube 84 passes, in order to suppress or prevent condensation on the inner wall of the tube caused by the suction of the particulate mixture. Its structure and function are arbitrary, but for example, it is made by winding a self-regulating heater wire that generates heat when an electric current is applied around the tube 85.

[0079] The particulate mixture drawn into the sampling tube 84 from the fire compartment is at a high temperature, and in addition to fine particles (smoke particles), it also contains water vapor. As the drawn-in high-temperature particulate mixture cools as it passes through the sampling tube 84 and tube 85, condensation may occur on the inner wall of the tube. When condensation occurs on the inner wall of tube 85, the fine particles of the drawn particulate mixture are attracted to the water droplets on the inner wall of the tube, resulting in a partial loss of fine particles contained in the particulate mixture. Therefore, by providing a heating section 85a to heat tube 85, condensation caused by the cooling of the particulate mixture is suppressed or prevented, allowing the particulate mixture to reach the entrance of the charge detector 80 without losing any contained fine particles, thereby improving the detection accuracy of the charge polarity of the particulate mixture.

[0080] In this embodiment, a heating element 85a is provided on one end of the tube 85 connected to the charge detector 80, but it can be placed in any suitable location as long as condensation can be suppressed or prevented. Similarly, a heating element may also be provided on the sampling tube 84 to suppress or prevent condensation on the inner wall of the sampling tube 84.

[0081] (e1-3. Suction pump) The suction pump 88 will now be described in more detail. The suction pump 88 has the outlet of the electrostatic detector 80 connected to the suction port via a tube 86. It draws in a mixture of particulate matter through the sampling tube 84 and tube 85, and exhausts the mixture of particulate matter that has passed through the electrostatic detector 80 to the outside. The structure and function of the suction pump 88 are arbitrary, but a suitable pump that draws in and discharges gas using a motor drive, such as an axial flow pump, is used. The structure and material of the tube 86 are also arbitrary, but like the tube 85 mentioned above, it is made of synthetic resin or rubber, such as a tube or hose.

[0082] (e2. Holding device) The holding device will be described in more detail. The holding device movably holds the sampling tube 84 and tube 85 so that the suction port 84a of the sampling tube 84 is inserted into the particulate mixture generated in the fire compartment. Its structure and function are arbitrary, but for example, it consists of a rod member 90, a support part 92, and a weight 94.

[0083] 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. Its structure and function are arbitrary, but for example, it is a metal rod or pipe that has rigidity in the front-to-back direction, which is the extension direction of the tube 85, and its length is also arbitrary, but for example, it is about 2 to 3 m. The rod member 90 is also provided so that when the tube 85 is contracted to its maximum extent, the tip of the rod member 90 is positioned on the outer circumference of the sampling tube 84 on the suction port 84a side, and holds the sampling tube 84 and the tube 85 in this state. When the tube 85 is extended, the rod member 90 maintains its position of holding the sampling tube 84 and the tube 85, while the tip of the rod member 90 moves along the outer circumference of the sampling tube 84 in the extension direction.

[0084] Furthermore, if the tip of the rod member 90 is also inserted into the fire compartment depending on the insertion depth of the sampling tube 84, the rod member 90 should be made of a heat-resistant material similar to the sampling tube 84. Alternatively, instead of being a rigid material in the direction of extension 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 circumference of the suction port 84a side of the sampling tube 84 being fixed, so that the rod member 90 extends (contracts) in accordance with the extension (contraction) of the tube 85.

[0085] The support section 92 supports the rod member 90 so that the position of the sampling tube 84 and tube 85, which are held by the rod member 90, can be adjusted so that the intake port 84a of the sampling tube 84 is at any position corresponding to the fire compartment.

[0086] The structure and mechanism of the support section 92 are arbitrary, but for example, it may be a three-dimensional swivel structure. As a mechanism to realize the three-dimensional swivel structure, for example, a fixed base 92a is placed on the upper part of the blower section 28, and a support shaft section 92b which serves as a vertical support axis is erected on the fixed base 92a. The support shaft section 92b pivotally supports, for example, a U-shaped support section 92c at its upper end so as to be rotatable around the support axis (left and right), and also pivotally supports around a horizontal axis (up and down) located at the height of the support section 92c in the left and right direction perpendicular to the support axis.

[0087] Furthermore, by detachably supporting the rod member 90 on the support portion 92c of the support portion 92, the rod member 90 can move not only in the forward and backward direction which is the extension direction, but also in the left and right rotation and up and down rotation. This allows the tip of the rod member 90, which is located on the fire compartment side and positioned on the outer circumference of the sampling tube 84, to be rotated in the left and right and up and down directions. As a result, the position of the intake port 84a of the sampling tube 84 can be adjusted in all directions: up and down, left and right, and forward and backward.

[0088] Furthermore, a weight 94 is placed at the rear end of the rod member 90. The weight of the weight 94 is set such that the moment of force at the tip of the rod member 90, which holds the sampling tube 84 and tube 85 with the support portion 92 as the fulcrum, is approximately the same as the moment of force at the rear end where the weight 94 is placed, thereby balancing the rod member 90 to maintain a horizontal position.

[0089] Furthermore, the extension of the pole member 90 may be achieved, for example, by moving the basket 120 at the tip of the retractable ladder 118 shown in Figure 9.

[0090] (e3. Electrostatic detector) The charge detector 80 will now be explained in more detail. The charge detector 80 detects the charge polarity of fine particles (smoke particles) contained in the particulate mixture generated in the fire compartment, that is, whether the charge polarity of the fine particles is negative or positive. Its configuration, structure, and function are arbitrary, but for example, as shown in Figure 7(A) and the cross-section viewed from the left in Figure 6, it consists of an electrode structure, a charge detection unit 105, and a determination unit 114. Figure 7(B) shows the electrode structure and the charge detection unit 105 viewed from the rear.

[0091] (e3-1. Electrode structure) The electrode structure of the charge detector 80 will be described in more detail. The electrode structure of the charge detector 80 is arbitrary, but for example, it consists of a cylindrical electrode 95 and a Faraday cage 96.

[0092] The cylindrical electrode 95 is an electrode conductor formed in a cylindrical shape with a hollow section, and it allows the particulate mixture 100, which is drawn in by the suction device 82, to pass from the inlet side at one end of the hollow section to the outlet side at the other end. Here, Figure 7 shows a cylindrical cylindrical electrode 95, but it is not limited to a cylindrical shape, and the shape of the cylindrical cross-section may be polygonal, elliptical, etc., as long as the particulate mixture can pass from the inlet side at one end of the hollow section to the outlet side at the other end.

[0093] The Faraday cage 96 functions as an electromagnetic shield by creating a space that suppresses or prevents the influence of electrical disturbances (noise) on the cylindrical electrode 95 by covering its outer circumference with a conductor that is electrically insulated from the cylindrical electrode 95 and is grounded. The structure and shape of the Faraday cage 96 are arbitrary, but for example, it is composed of conductive outer cylinders 98a and 98b.

[0094] The outer cylinder 98a is arranged to surround the outer circumference of the inlet 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 inlet side of the cylindrical electrode 95, and a small-diameter cylindrical section that forms a canopy portion through which the inlet hole passes. A flange is provided at the end of the large-diameter cylindrical section. The inner diameter of the cylindrical hole in the large-diameter cylindrical section is the outer diameter of the cylindrical electrode 95 plus an insulating space (insulation gap), and the length of the hole is approximately half the length from the inlet of the cylindrical electrode 95 plus an insulating space (insulation gap). The inlet hole that passes through the small-diameter cylindrical section has the same inner diameter as the inner diameter of the cylindrical electrode 95.

[0095] The outer cylinder 98b is positioned to surround the outer circumference of the outlet side of the cylindrical electrode 95 and has the same structure as the outer cylinder 98a.

[0096] The Faraday cage 96 covers the outer circumference of the cylindrical electrode 95 while electrically insulating it from the outside of the Faraday cage 96. This is achieved by fitting the large-diameter cylindrical holes of the outer cylindrical bodies 98a and 98b into the inlet and outlet ends of the cylindrical electrode 95 via insulating rings 102, and then butting the flanges of the two bodies together and connecting and fixing them with screws. Furthermore, as shown in Figure 7(B), the upper sides of the flanges of the outer cylindrical bodies 98a and 98b are flattened, and the grounded conductor case 104 is attached and fixed to the flattened portion, thereby electrically grounding the Faraday cage 96.

[0097] Furthermore, the Faraday cage 96 has a length L of the small-diameter cylindrical portion of the outer cylinders 98a and 98b that is at least twice the inner diameter D of the cylindrical electrode 95. By making the length L of the small-diameter cylindrical portion of the outer cylinders 98a and 98b at least twice the inner diameter D of the cylindrical electrode 95, external noise to the cylindrical electrode 95 via the inlet and outlet of the Faraday cage 96 can be suppressed or prevented.

[0098] The cylindrical electrode 95, enclosed in a Faraday cage 96, has a conductor 108 positioned upright approximately in the center of its upper outer circumference. The conductor 108 is input-connected to an operational amplifier 106 housed in a conductor case 104. Therefore, openings are provided in the Faraday cage 96 and the conductor case 104 to allow the conductor 108 to pass through.

[0099] (e3-2. Charge detection unit) The charge detection unit 105 will now be described in more detail. The charge detection unit 105 converts the induced charge of the same polarity as the charged particles attracted to the outer surface of the cylindrical electrode 95 by the charge of the charged particles contained in the particulate mixture 100 passing through the cylindrical electrode 95 into a voltage signal and outputs it. Its configuration and function are arbitrary, but for example, it is composed of an operational amplifier 106 and a resistor 110. In practice, the operational amplifier 106 and the resistor 110 are mounted on the circuit board 112.

[0100] The operational amplifier 106 has its inverting input terminal (- input terminal) connected to the outer circumference of the cylindrical electrode 95 via a conductor 108, its non-inverting input terminal (+ input terminal) connected to the grounded conductor case 104, and its output terminal connected to the inverting input terminal via a resistor 110 for negative feedback, and also connected to the determination unit 114. This configuration utilizes the imaginary short-circuit operation (virtual ground operation) of the operational amplifier 106 to convert induced charge into a voltage signal.

[0101] Here, the imaginary short operation of the operational amplifier 106 means that when negative feedback is applied to the operational amplifier 106 via resistor 110, it operates in such a way that the potential difference between the non-inverting input terminal and the inverting input terminal of the operational amplifier 106 becomes 0V (virtual ground).

[0102] (e3-3. Operation of the charge detection unit) The charge detection operation of the charge detection unit 105, which detects the charge of charged fine particles contained in the fine particle mixture, will be explained in more detail. Figure 8(A) shows the charge detection operation when the fine particles in the fine particle mixture passing through the cylindrical electrode 95 of the charge detection unit 105 are positively charged. When positively charged fine particles pass through the cylindrical electrode 95, negative charges are attracted to the inner surface of the cylindrical electrode 95, and conversely, positive charges are attracted to the outer surface of the cylindrical electrode 95. Therefore, the voltage on the inverting input terminal side of the operational amplifier 106 corresponds to the voltage on the non-inverting input terminal side (ground potential, 0V) corresponding to the positive charges attracted to the outer surface of the cylindrical electrode 95. For this, it becomes +Vq.

[0103] At this time, the op-amp 106 operates in an imaginary short-circuit state, and the voltage +Vq at the inverting input terminal is set to equal the voltage at the non-inverting input terminal (ground potential, 0V) via resistor 110 from the output terminal. A current Iq flows from the output terminal through the resistor 110 to the inverting input terminal so that the voltage becomes +Vq. As a result, the output voltage of the operational amplifier 106 becomes +Vq, and a charge detection voltage signal corresponding to the positive charge of the charged particles passing through the cylindrical electrode 95 is output.

[0104] Here, when a particulate mixture 100 containing positively charged fine particles passes through the cylindrical electrode 95, the positive charge induced on the outer surface of the cylindrical electrode 95 increases in proportion to the decrease in distance to the conductor 108 until the charged fine particles reach the position where the conductor 108 is upright. The positive charge peaks at the position where the conductor 108 is upright, and decreases as the particles move away from the conductor 108. The charge detection voltage signal +Vq output by the operational amplifier 106 also changes in accordance with the change in the positive charge induced on the outer surface of the cylindrical electrode 95. Furthermore, when the positively charged fine particles exit the cylindrical electrode 95, a negative charge with the opposite polarity is induced on the outer surface of the cylindrical electrode 95. Therefore, at this timing, the charge detection voltage signal output from the operational amplifier 106 changes to -Vq. In other words, when positively charged microparticles pass 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.

[0105] Figure 8(B) shows the charge detection operation when the fine particles contained in the fine particle mixture 100 passing through the cylindrical electrode 95 of the charge detection unit 105 are negatively charged. When negatively charged fine particles pass through the cylindrical electrode 95, positive charges are attracted to the inner surface of the cylindrical electrode 95, and conversely, negative charges are attracted to the outer surface of the cylindrical electrode 95. Therefore, in response to the negative charges attracted to the outer surface of the cylindrical electrode 95, the voltage on the inverting input terminal side of the operational amplifier 106 is compared to the voltage at the non-inverting input terminal (ground potential, 0V). This results in -Vq.

[0106] At this time, the op-amp 106 operates in an imaginary short-circuit state, and the voltage -Vq at the inverting input terminal is taken from the output via resistor 110 and made equal to the voltage at the non-inverting input terminal (ground potential, 0V). A current Iq flows from the inverting input terminal to the output terminal via the resistor 110 to create a voltage. As a result, the output voltage of the operational amplifier 106 becomes -Vq, and a charge detection voltage signal corresponding to the negative polarity charge of the charged particles passing through the cylindrical electrode 95 is output. Furthermore, when the negative polarity charged particles exit the cylindrical electrode 95, a positive polarity charge, which is the opposite polarity, is attracted to the outer surface of the cylindrical electrode 95, and at this timing, the charge detection voltage signal output from the operational amplifier 106 changes to +Vq. In other words, when negative polarity charged particles pass through the cylindrical conductor 95, the operational amplifier 106 outputs a charge detection voltage signal that differentially changes from a negative voltage -Vq to a positive voltage +Vq.

[0107] (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 mixture is performed by the determination unit 114 determining the charge polarity of the particulates contained in the particulate 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 mixture 100 based on the charge detection voltage signal output from the charge detection unit 105 and outputs it to the control unit 21. The determination method is arbitrary, but for example, the charge polarity of the charged particulates can be determined based on the integral result of the charge detection voltage signal output from the charge detection unit 105. The integral result of the charge detection voltage signal is generated in a time series by continuously integrating the input charge detection voltage signal.

[0108] The determination unit 114 determines that the charge polarity of the charged particles is negative if the integrated value of the charge detection voltage signal shows a decreasing trend over time, and that the charge polarity of the charged particles is positive if the integrated value of the charge detection voltage signal shows an increasing trend over time. The determination unit 114 may be provided in the control unit 21 instead of the charge detector 80.

[0109] (e5. Switching control of the charge polarity of charged water particles) The control unit 21 will now explain in more detail how it controls the switching of the charge polarity of charged water particles. Based on the charge polarity of the fine particles contained in the fine particle mixture 100 determined by the determination unit 114 of the charge detector 80, the control unit 21 controls the switching of the charge polarity of the charged water particles contained in the charged water particle gas stream 12 released from the charged water particle release unit 10 so that the charge polarity of the charged water particles is opposite to that of the fine particles contained in the fine particle mixture 100.

[0110] When the control unit 21 determines that the charge polarity of the fine particles contained in the fine particle mixture 100 is positive using the determination unit 114 of the charge detector 80, it switches the charge polarity of the charged water particles contained in the charged water particle airflow 12 released from the charged water particle discharge unit 10 to negative polarity. When the charged water particle airflow 12 containing negatively charged water particles is released into the fire compartment, the positively charged fine particles (smoke particles) contained in the fine particle mixture are attracted to and captured by the negatively charged water particles by electrostatic force, resulting in high smoke extinguishing performance.

[0111] Here, the control unit 21 switches the charge 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 that a high voltage is applied so that the potential of the induction electrode portion 60 of the charged spray head 32 is positive relative to the potential of the water-side electrode portion 62.

[0112] Furthermore, if the determination unit 114 of the charge detector 80 determines that the charge polarity of the fine particles contained in the fine 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 released from the charged water particle release unit 10 to positive polarity. When the charged water particle airflow 12 containing positively charged water particles is released, negatively charged fine particles (smoke particles) contained in the fine particle mixture are attracted to the positively charged water particles by electrostatic force, captured, and removed, resulting in high smoke-removing performance.

[0113] Here, the control unit 21 switches the charge polarity of the charged water particles to positive polarity by controlling the polarity reversal circuit 68 of the high-voltage power supply unit 18 so that a high voltage is applied so that the potential of the induction electrode portion 60 of the charged spray head 32 becomes negative relative to the potential of the water-side electrode portion 62.

[0114] [f. Types of fire and the charge polarity of charged water particles] The relationship between the charge polarity of the charged water particles contained in the charged water particle airflow 12 released from the charged water particle discharge unit 10 and the type of fire will be explained in more detail.

[0115] According to the inventors of this application, it has been experimentally confirmed that in order to obtain high fire extinguishing and smoke suppression performance, there is a specific correspondence between the type of fire and the charge polarity of charged water particles.

[0116] (f1. Charge polarity of water particles in relation to wood fires) A wood fire is a fire in which wood containing cellulose, paper, etc., burns, and produces relatively white or gray smoke (white smoke or gray smoke). For convenience, it is called a wood fire. Note that water vapor is not included in white smoke. When comparing the application of positively charged water particles to a wood fire with the application of negatively charged water particles, for example, the time from the start of application until the smoke concentration decreases to a predetermined level is shorter when negatively charged water particles are applied than when positively charged water particles are applied. Therefore, negatively charged water particles provide higher smoke suppression performance for wood fires.

[0117] (f2. Charge polarity of water particles in relation to oil fires) An oil fire is a fire in which liquid fuels containing hydrocarbons, oils and fats, synthetic resins, etc., burn, and produces relatively black smoke (black smoke), and is conveniently called an oil fire. When comparing the case of spraying positively charged water particles with the case of spraying negatively charged water particles in an oil fire, 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 extinguishing performance is observed. However, it has been found that the smoke extinguishing performance is not impaired even when the amount of negatively charged water particles sprayed is reduced.

[0118] (f3. Initial setting of water particle charge polarity) In this embodiment, it may take some time for the determination unit 114 of the charge detector 80 to determine the charge characteristics of the fine particles contained in the particulate mixture generated in the fire compartment and for the control unit 21 to switch the charge polarity of the charged water particles. Therefore, it is necessary to initially set a predetermined charge polarity for the charged water particles. In this case, as mentioned above, in the case of an oil fire, there is no difference in fire extinguishing and smoke extinguishing performance depending on the charge polarity of the charged water particles, and in the case of a wood fire, smoke extinguishing performance is better when the charge polarity of the charged water particles is negative. Therefore, it is preferable to initially set the charge polarity of the charged water particles to negative polarity.

[0119] Accordingly, the control unit 21 is initially set to have the charged water particles contained in the charged water particle airflow 12 released into the fire compartment charged to a negative polarity. During the release of the charged water particle airflow 12 containing charged water particles charged to a negative polarity according to the initial setting, if the determination unit 114 of the charge detector 80 determines that the charge polarity of the particulate mixture is negative, which is the same polarity as the charged water particles, the control unit 21 switches the charge polarity so that the charged water particles are charged from the initially set negative polarity to the opposite positive polarity.

[0120] Here, initializing the charged water particles to be negatively charged means that, without requiring an operator to manually set the polarity of the charged water particles, the operation to activate the discharge of the charged water particle airflow 12 sets the high voltage applied from the high-voltage power supply unit 18 to the charged spray head 32 so that the potential of the induction electrode portion 60 of the charged spray head 32 is positive relative to the potential of the water-side electrode portion 62.

[0121] [g.Control panel] The control panel 14 shown in Figure 1 will be described in more detail. The control panel 14 is an operating unit for an operator to operate the charged water particle spraying system of this embodiment. The operations 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 amount of spray from each charged spray head 32, selecting the type of voltage to be applied by the high-voltage power supply unit 18, and performing voltage adjustment and polarity switching operations.

[0122] The control panel 14 is equipped with an operation display unit 20 and a control unit 21. The operation display unit 20 is equipped with various operation buttons, operation levers, a display, indicator lights, etc., necessary for remote operation of the charged water particle release unit 10. The control unit 21 outputs control signals based on the operator's actions on the operation display unit 20 and controls the charged water particle release unit 10, etc. Its functions and configuration are arbitrary, but for example, it is composed of a computer circuit equipped with a CPU, memory, various input / output ports, etc., and predetermined control functions are realized by the execution of a program by the CPU.

[0123] [h. Ladder fire truck equipped with a charged water particle dispersal system] The firefighting, fire prevention, and smoke suppression operations 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 firefighting, fire prevention, and smoke suppression operations using a ladder fire truck equipped with the charged water particle spraying system of this embodiment at a fire scene. The basket 120 at the tip of the extendable ladder 118 is equipped with the charged water particle discharge unit 10, the charge detector 80, and the suction device 82 shown in Figure 1, while the control panel 14, the fire extinguishing agent water supply unit 16, and the high-voltage power supply unit 18 are located on the ladder fire truck 76 side.

[0124] For example, if a fire breaks out on the third floor of building 122, the ladder fire truck 116 that arrives at the scene of the fire extends its ladder 118 so that the charged water particle discharge unit 10 located in the basket 120 is brought close to an exterior wall opening such as a window of the building. Next, by performing a discharge activation operation on the control panel 14 to discharge the charged water particle airflow 12, firefighting water is supplied from the fire extinguishing agent water supply unit 16 to the charged water particle discharge unit 10, a high voltage is applied to the charged water particle discharge unit 10 from the high-voltage power supply unit 18, and the blower unit 28 is activated by a control signal from the control panel 14. As a result, the airflow from the blower unit 28 contains charged water particles that are negatively charged according to the initial settings and sprayed from the charged spray head 32, and the charged water particle airflow 12 is discharged toward the fire compartment 124.

[0125] Furthermore, when the ladder 118 is extended and the charged water particle discharge unit 10 provided on the basket 120 is brought close to an exterior wall opening such as a window of the building, the sampling tube 84 of the suction device 82 positioned above the charged water particle discharge unit 10 is inserted into the particulate mixture containing smoke particles from the fire occurring in the fire compartment 124. The suction device 82 then draws the particulate mixture in so that it reaches the charge detector 80, and the charge detector 80 detects the charge polarity of the particulate mixture. As mentioned above, the position of the sampling tube 84 can be adjusted in the front-to-back, left-to-right, and up-and-down directions, so an operator on the basket 120 can adjust the insertion position of the sampling tube 84.

[0126] Furthermore, after the discharge of the charged water particle airflow 12 begins, the operator can adjust the direction of the charged water particle airflow 12 upwards and / or left and right by operating the control panel 14 to adjust the direction of discharge of the charged water particle airflow 12 toward the fire compartment 124. In addition, 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 is opposite to the charge polarity of the particulate mixture detected by the charge detector 80.

[0127] Furthermore, the operator will adjust the direction of discharge of the charged water particle airflow 12, adjust the applied voltage by the high-voltage power supply unit 18, and switch the polarity of the applied voltage as needed, based on the fire extinguishing and smoke suppression situation caused by the discharge of the charged water particle airflow 12. This will allow the operator to discharge the charged water particle airflow 12 containing charged water particles with an appropriate charge amount and polarity for fire extinguishing and smoke suppression at the fire scene into the fire compartment 124 to extinguish, prevent fires, and suppress smoke.

[0128] [i. Control operation of the charged water particle dispersal system] An example of the control operation of the charged water particle dispersal system by the control unit 21 will be explained in more detail with reference to the flowchart in Figure 10.

[0129] The charged water particle dispersal system is activated, and the control unit 21 of the control panel 14 shown in Figure 1 performs the control operations shown in Figure 10.

[0130] In Figure 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 released in step S1 to negative polarity. In step S2, when the operator determines that a release start instruction has been issued, such as by operating the release start operation on the control panel 14, the process proceeds to step S3, where the fire extinguishing agent supply unit 16 is activated to supply a fire extinguishing agent, such as fire extinguishing water, to the multiple charged spray heads 32 provided on the charged water particle release unit 10. In step S4, the water particles are charged to negative polarity according to the initial setting, and the charged water particle airflow 12 containing the negatively charged water particles is released towards the fire compartment.

[0131] Next, the control unit 21 determines whether the charge polarity of the particulate mixture detected by the charge detector 80 in step S5, the so-called charge polarity of the particulate matter (smoke particles), is negative or not. If the charge polarity of the particulate mixture is negative, the process proceeds to step S6, where the charge polarity of the charged water particles is switched to positive and the charged water particle gas stream 12 is released. If the charge polarity of the charged water particles is already positive, no switching control is performed.

[0132] On the other hand, if step S5 determines that the charge polarity of the particulate mixture is not negative, that is, that the charge polarity of the particulate mixture is positive, the process proceeds to step S7, where the charge polarity of the charged water particles is switched to negative and the charged water particle gas stream 12 is released. However, if the process proceeds to step S7 for the first time, the water particles are charged to a negative polarity in step S4 based on the initial settings, so no switching control is performed in order to maintain the negative charge polarity.

[0133] Next, in step S8, the control unit 21 determines that the amount of spray from the charged spray heads 32 has been changed due to the operator's actions, etc., and proceeds to step S9. There, it selects the number of charged spray heads 32 to spray by selectively opening and closing the on-off valve 35 shown in Figure 5 and changes the amount of spray. Alternatively, the amount of spray from the charged spray heads 32 may be adjusted by changing the amount of fire extinguishing agent supplied from the fire extinguishing agent supply unit 16 to the charged spray heads 32.

[0134] Next, if the control unit 21 determines in step S10 that the amount of charge of the charged water particles has changed due to the operator's actions, etc., 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 amount of charge of the charged water particles.

[0135] Next, the control unit 21 proceeds to step S12, and when the abnormal current detection circuit 74 shown in Figure 4 detects an abnormal current due to an insulation failure 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 stop the application of high voltage to all heads, including the charged spray head 32 in which the abnormal current was detected.

[0136] Next, the control unit 21 proceeds to step S14 and repeats the process from step S5 until it determines that the release has ended due to an operation by an operator or the like. Once the release has ended instruction is determined, it proceeds to step S15 and terminates by performing a predetermined release termination process to stop the release of the charged water particle gas stream 12.

[0137] [j. Modified versions of the present invention] (fire engine) The above embodiment uses a ladder fire truck as an example of a system for spraying charged water particles, but it does not prevent the system from being mounted on any suitable fire truck, as long as it is a fire truck capable of bringing the charged water particle discharge unit 10 close to a fire compartment at a high elevation in a building from the outside. For example, in the case of a high-altitude work fire truck, the charged water particle discharge unit 10 can be installed on the high-altitude work platform, and in the case of a boom fire truck, the charged water particle discharge unit 10 can be installed at the tip of the boom. Furthermore, the charged water particle discharge unit 10 can be mounted on a tracked self-propelled vehicle, and it can be remotely operated to move to a fire compartment that is inaccessible to humans and inject a stream of charged water particles.

[0138] (High-voltage supply unit) In the above embodiment, a DC voltage is applied from the high-voltage power supply unit 18 between the induction electrode section 60 and the water-side electrode section 62 of the charged fine spray head 32. However, in addition to a DC voltage, a pulse voltage, pulsating voltage, or AC voltage may also be applied. Furthermore, while voltage adjustment and voltage polarity switching are possible when applying voltage from the high-voltage power supply unit 18 between the induction electrode section 60 and the water-side electrode section 62, this is not limited to this and is optional; for example, the applied voltage and / or voltage polarity may be fixed.

[0139] (others) Furthermore, the present invention is not limited to the embodiments described above, and includes appropriate modifications that do not impair its purpose and advantages, and is not limited by the numerical values ​​shown in the embodiments described above. [Explanation of symbols]

[0140] 10: Charged water particle emission section 12: Charged water particle airflow 14:Operation panel 16: Fire extinguishing agent supply unit 18: High-voltage power supply unit 20: Operation display section 21: Control Unit 22: Water pipe 24: High-voltage cable 24a: Voltage application cable 24b: Ground cable 26a~26f: Signal cables 28: Blower unit 30: Charged water particle generation unit 31: Support ring 32: Electrostatic spray head 34: Axial flow fan 35: Shut-off valve 36: Fan motor 38: Protective cover 40: Stand 42: Rotating support section 44:Left and right adjustment section 46: Left and right pivot axis 48: Vertical adjustment section 50: Up and down pivot axis 52: Center of gravity 54: Body 56: Spray nozzle section 58: Electrode holding part 60: Induction electrode part 62: Water side electrode part 64: Water supply connection 66: High-voltage variable circuit 68: Polarity Reversal Circuit 72: Selection Circuit 74: Abnormal current detection circuit 75, 77: Switch circuits 76: Current limiting resistor 78: Current sensing resistor 80: Electrostatic 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: Particulate mixture 102: Insulating ring 104: Conductor case 105: Charge detection unit 106: Operational amplifier 108: Conductor 112: Circuit board 114: Judgment section 116: Ladder fire truck 118: Ladder 120: Basketball 122: Building 124: Fire Compartment

Claims

[Claim 1] A charged water particle dispersal system that disperses charged water particles onto a target area, Multiple charged spray heads that generate and spray charged water particles for spraying onto the target area by charging water particles by applying a predetermined voltage between two electrodes, A power supply unit that applies a predetermined voltage between two electrodes of the plurality of charged spray heads, An abnormal current detection unit for each of the plurality of charged spray heads detects an abnormal current flowing between the two electrodes, Equipped with, One electrode of the plurality of charged spray heads is connected to the power supply unit via a first switch unit provided individually for each of the plurality of charged spray heads. The other electrode of the plurality of charged spray heads is connected to the power supply unit via a second switch unit that is commonly provided for the plurality of charged spray heads. When the abnormal current detection unit detects a current abnormality in at least one of the plurality of charged spray heads and stops applying the voltage to the charged spray head in which the current abnormality was detected, the first switch unit corresponding to the charged spray head in which the current abnormality was detected is turned off, and one electrode of the charged spray head in which the current abnormality was detected is disconnected from the power supply unit. A charged water particle spraying system characterized in that, when the abnormal current detection unit detects a current abnormality in at least one of the plurality of charged spray heads and stops the application of the voltage to all of the charged spray heads, all of the first and second switch units are turned off to disconnect the two electrodes of all of the charged spray heads from the power supply unit.

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