A fire-fighting foam mixing system coupled with water supply

Abstract

The present application relates to the field of fire extinguishing systems, and more particularly to a fire foam mixing system coupled with water supply, comprising a foam stock tank, a venturi tube, a main water supply pipe, a target water pump, and a pressure regulating valve; one end of the main water supply pipe is connected to the water supply port of the target water pump, and the other end of the main water supply pipe is used to access a water source; the inlet end of the venturi tube is connected to the water outlet of the target water pump, the outlet end of the venturi tube is connected to the main water supply pipe, and the low-pressure port of the venturi tube is connected to the foam stock tank via a foam supply pipe; the pressure regulating valve is connected to the main water supply pipe and can regulate the water pressure entering the main water supply pipe. The present application facilitates the addition of foam to the target water pump in a coupled water supply state.

Description

Technical Field

[0001] The present application relates to the field of fire extinguishing systems, and in particular to a fire foam mixing system coupled with water supply. Background Art

[0002] Currently, foam fire trucks in the industry often use a ring pump negative pressure foam system for firefighting operations. This system requires a slightly negative pressure state at the water pump inlet and a sufficient pressure differential between the drainage pressure of the Venturi tube and the pressure of the water pump inlet to achieve the suction of the foam liquid into the water pump. However, during "coupled" water supply operations, since the water pump inlet is at positive pressure, it is impossible to ensure that a sufficient pressure differential is established between the foam drainage system and the "coupled" water supply pipeline to drain the foam, and a stable Venturi effect cannot be formed to draw the foam liquid into the operation.

[0003] However, in related technologies, when "coupled" water supply operations are performed, fire trucks cannot activate the negative pressure foam system, thus failing to maximize the performance advantages of the water pump and achieve more efficient firefighting performance. Therefore, it is very necessary to develop a system that can apply negative pressure ring pump foam firefighting in a coupled water supply state. Summary of the Invention

[0004] In order to facilitate the addition of foam to a water pump in a coupled water supply state, the present application provides a fire-fighting foam mixing system coupled with water supply.

[0005] In a first aspect, the present application provides a fire-fighting foam mixing system coupled with water supply, which adopts the following technical solutions:

[0006] A fire-fighting foam mixing system coupled with water supply, comprising: a foam stock tank, a venturi tube, a main water supply pipe, a target water pump and a pressure regulating valve;

[0007] One end of the main water supply pipe is connected to the water supply port of the target water pump, and the other end of the main water supply pipe is used to connect to the water source;

[0008] The inlet end of the venturi tube is connected to the water outlet of the target water pump, the water outlet end of the venturi tube is connected to the main water supply pipe, and the low-pressure port of the venturi tube is connected to the foam liquid tank via a foam supply pipe;

[0009] The pressure regulating valve is connected to the main water supply pipe and can regulate the water pressure entering the main water supply pipe.

[0010] By adopting the above technical solution, the main water supply pipe is connected to a pressurized water source, so that the main water supply pipe is in a positive pressure state; by setting a pressure regulating valve, the opening of the pressure regulating valve is reduced through adjustment, thereby reducing the water pressure in the water supply pipe, which increases the pressure difference between the water inlet of the venturi tube and the water outlet of the venturi tube connected to the main water supply pipe, thereby increasing the vacuum degree in the low-pressure port of the venturi tube, and enabling the foam concentrate in the foam concentrate tank to enter the main water supply pipe through the venturi tube under pressure for mixing, and then the mixed liquid can enter the target water pump, so as to facilitate the mixing of the foam concentrate into the target water pump while coupling the water supply to the target water pump.

[0011] In one possible implementation, the system further includes an electronic device, and the pressure regulating valve is an electrically controlled regulating valve;

[0012] A first vacuum sensor is provided in the low-pressure port of the venturi tube, and the first vacuum sensor is capable of detecting the vacuum degree at the low-pressure port of the venturi tube and outputting a vacuum degree signal;

[0013] The electronic device obtains the vacuum signal, and when the vacuum at the low-pressure port of the venturi tube is greater than 0, the electronic device outputs a reduction signal to reduce the opening of the pressure regulating valve.

[0014] By adopting the above technical solution, when the vacuum degree at the low-pressure port of the venturi tube detected by the first vacuum sensor is greater than 0, it indicates that the pressure in the main water supply pipe is relatively high, and the foam concentrate in the foam concentrate tank cannot enter the main water supply pipe through the venturi tube under the action of pressure. At this time, the electronic device can automatically output a reduction signal to reduce the opening of the pressure regulating valve, so as to reduce the water pressure in the main water supply pipe. By setting the pressure regulating valve as an electric regulating valve, the manual adjustment process is reduced and the convenience is improved.

[0015] In one possible implementation, a foam switching valve is provided on the foam supply pipe. When the vacuum degree at the low-pressure port of the venturi tube is less than a preset value, the electronic device outputs an opening signal to open the foam switching valve, and the preset value is less than or equal to 0.

[0016] By adopting the above technical solution, when the vacuum degree at the low-pressure port of the venturi tube is less than 0, the foam liquid in the foam liquid tube can enter the main water supply pipe through the venturi tube. At this time, the electronic device outputs an open signal to open the foam switch valve, thereby facilitating the foam liquid to enter the venturi tube.

[0017] In one possible implementation, the system further includes a proportional regulating valve and a water outlet flow meter;

[0018] The water outlet flow meter is arranged at the water outlet end of the target water pump, and is capable of detecting and outputting a flow signal representing the liquid flow at the water outlet end of the target water pump;

[0019] The proportional regulating valve is arranged on the foam supply pipe, one end of the proportional regulating valve is connected to one end of the foam switching valve, and the other end of the proportional regulating valve is connected to the low-pressure port of the venturi tube;

[0020] The electronic device outputs a regulating signal based on the flow signal to adjust the opening of the proportional regulating valve.

[0021] By adopting the above technical solution, the water outlet flow meter can detect the water outlet flow of the target water pump and output a flow signal. The opening of the proportional control valve can affect the amount of foam stock solution entering the main water supply pipe per unit time. By adjusting the opening of the proportional control valve based on the output signal time of the flow control signal, the amount of foam stock solution entering the main water supply pipe is adjusted based on the flow rate of the target water pump outlet.

[0022] It is convenient for the proportion of foam in the foam water solution discharged from the water outlet of the target water pump to be stable.

[0023] In one possible implementation, a one-way valve is provided on the foam supply pipeline, the water outlet of the one-way valve is connected to the low-pressure port of the venturi tube, and the water inlet of the one-way valve is connected to the end of the proportional control valve that is not connected to the foam switch valve.

[0024] By adopting the above technical solution, the one-way valve can reduce the probability of water in the main water supply pipe flowing back into the foam supply pipe, thereby reducing the probability of contamination of the foam concentrate in the foam concentrate tank.

[0025] In one possible implementation, when the vacuum degree at the low-pressure port of the venturi tube is greater than 0, the electronic device outputs a closing signal to close the proportional control valve.

[0026] By adopting the above technical solution, when the vacuum degree at the low-pressure port of the venturi tube is greater than 0, the water pressure in the main water supply pipe is relatively high, and the electronic device outputs a closing signal to close the proportional control valve, thereby reducing the probability of water in the main water pipe flowing back through the proportional control valve into the foam concentrate tank.

[0027] In one possible implementation, a cleaning valve is connected between the water outlet of the target water pump and the foam supply pipe, one end of the cleaning valve is connected to the water outlet of the target water pump, and one end of the cleaning valve is connected to one end of the foam switch valve and the proportional control valve.

[0028] By adopting the above technical solution, when the mixing of foam concentrate into the main water supply pipe is stopped, foam concentrate will remain in the foam supply pipe, the one-way valve and the proportional control valve. At this time, the high-pressure liquid passing through the water outlet of the target water pump can enter the foam supply pipe from the proportional control valve through the cleaning valve, so as to facilitate the cleaning of the residual foam concentrate.

[0029] In one possible implementation, a foam inducing valve is connected between the inlet end of the venturi tube and the water outlet of the target water pump, and the foam inducing valve is opened in response to a foam inducing signal output by the electronic device.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. The main water supply pipe is connected to a pressurized water source, so that the main water supply pipe is in a positive pressure state; by setting a pressure regulating valve, the opening of the pressure regulating valve is reduced by adjustment, thereby reducing the water pressure in the water supply pipe, which increases the pressure difference between the water inlet of the venturi tube and the water outlet of the venturi tube connected to the main water supply pipe, thereby increasing the vacuum degree in the low-pressure port of the venturi tube, which enables the foam concentrate in the foam concentrate tank to enter the main water supply pipe through the venturi tube under the action of pressure and mix, and then the mixed liquid can enter the target water pump, so as to facilitate the mixing of the foam concentrate into the target water pump when the target water pump is coupled with water supply;

[0032] 2. The outlet flow meter can detect the outlet flow of the target water pump and output a flow signal. The opening of the proportional control valve can affect the amount of foam stock solution entering the main water supply pipe per unit time. By adjusting the proportional control valve opening based on the flow control signal output and the signal time, the amount of foam stock solution entering the main water supply pipe is adjusted based on the flow rate of the target water pump outlet, so that the proportion of foam in the foam water solution discharged from the outlet of the target water pump can be stabilized.

[0033] 3. When the vacuum degree at the low-pressure port of the Venturi tube is greater than 0, the water pressure in the main water supply pipe is relatively high, and the electronic device outputs a closing signal to close the proportional control valve, thereby reducing the probability of water in the main water pipe flowing back through the proportional control valve into the foam concentrate tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the connection relationship between various devices in the fire-fighting foam mixing system coupled with water supply according to an embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of the connection relationship between the electronic equipment and each valve in the embodiment of the present application.

[0036] Explanation of the accompanying symbols: 1. Electronic equipment; 2. Target water pump; 21. Water outlet flow meter; 3. Main water supply pipe; 31. Pressure regulating valve; 32. Second vacuum sensor; 4. Water storage tank; 41. Second liquid level gauge; 42. Water supply switch valve; 5. Foam raw liquid tank; 51. Foam supply pipe; 52. Foam switch valve; 53. Foam flow meter; 54. Proportional control valve; 55. One-way valve; 56. Cleaning valve; 57. First liquid level gauge; 6. Venturi tube; 61. First vacuum sensor; 62. Foam inlet valve. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-Figure 2 This application is described in further detail.

[0038] After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

[0039] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0040] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates an "or" relationship between the related objects.

[0041] The embodiment of the present application provides a fire fighting foam mixing system coupled with water supply, referring to Figure 1 The system includes a foam raw liquid tank 5, a venturi tube 6, a main water supply pipe 3, a target water pump 2 and a pressure regulating valve 31.

[0042] One end of the main water supply pipe 3 is connected to the water supply port of the target water pump 2, and the other end of the main water supply pipe 3 can be connected to a pressurized water source to form a coupled water supply to the target water pump 2. During coupled water supply, pressurized water flows through the main water supply pipe 3 to the water inlet of the target water pump 2. At this time, the main water supply pipe 3 is in a positive pressure state, and the target water pump 2 pressurizes the water flow at the water inlet before releasing it through the water outlet.

[0043] The inlet end of the venturi tube 6 is connected to the water outlet of the target water pump 2, and the water outlet end of the venturi tube 6 is connected to the main water supply pipe 3. The low-pressure port of the venturi tube 6 is connected to the foam concentrate tank 5 via the foam supply pipe 51. During the coupled water supply, after the water inlet of the venturi tube 6 is connected to the water outlet of the target water pump 2, water with positive pressure flows at the water inlet of the venturi tube 6, while the water outlet of the venturi tube 6 is in a positive pressure state connected to the main water supply pipe 3. Therefore, it is difficult for the low-pressure port of the venturi tube 6 to form a sufficient vacuum. Therefore, it is difficult for the foam concentrate to reach the venturi tube 6 from the foam concentrate tank 5, and thus cannot enter the main water supply pipe 3.

[0044] In the embodiment of the present application, a pressure regulating valve 31 is connected to the main water supply pipe 3. When an external pressurized water source passes through the main water supply pipe 3 and enters the water inlet of the target water pump 2, it needs to pass through the pressure regulating valve 3. By providing the pressure regulating valve 31, the opening of the pressure regulating valve 31 can be adjusted to be reduced, thereby reducing the water pressure in the main water supply pipe 3, thereby increasing the pressure difference between the water inlet of the venturi tube 6 and the water outlet of the venturi tube 6 connected to the main water supply pipe 3, thereby increasing the vacuum degree in the low-pressure port of the venturi tube 6, thereby enabling the foam concentrate in the foam concentrate tank 5 to enter the main water supply pipe 3 through the venturi tube 6 under the action of pressure and mix. Then, the mixed liquid can enter the target water pump 2, thereby achieving mixing of the foam concentrate in the target water pump 2 while coupling water supply to the target water pump 2.

[0045] Further, refer to Figure 1 A fire-fighting foam mixing system with coupled water supply also includes a water tank 4, which is connected to the main water supply pipe 3 through a normally closed water supply switch valve 42. The connection point between the water supply switch valve 42 and the main water supply pipe 3 is the first position, the position where the pressure regulating valve 31 is set on the main water supply pipe 3 is the second position, and the first position is between the water inlet of the target water pump 2 and the first position. In order to detect the remaining water amount in the water tank 4, a second liquid level gauge 41 is provided in the water tank 4. During coupled water supply, the water supply switch valve 42 is in a closed state, and at this time, no water is supplied to the target water pump 2 from the outlet pipe 4; when coupled water supply is not performed for the target water pump 2, the water stored in the water tank 4 can be used to supply the target water pump 2.

[0046] Further, refer to Figure 1 and Figure 2 A firefighting foam mixing system coupled with a water supply also includes an electronic device 1, and the pressure regulating valve 31 is an electrically controlled regulating valve. Electronic device 1 includes, but is not limited to, a single-chip microcomputer, a PLC controller, a mobile phone, a laptop computer, a PDA (personal digital assistant), a tablet computer, and other mobile terminals, as well as fixed terminals such as a desktop computer, and may also be a server.

[0047] A first vacuum sensor 61 is provided in the low-pressure port of the venturi tube 6. The first vacuum sensor 61 can detect the vacuum degree at the low-pressure port of the venturi tube 6 and output a vacuum degree signal; the electronic device 1 can obtain the vacuum degree signal. When the electronic device 1 compares the vacuum degree at the low-pressure port of the venturi tube 6 and finds that it is greater than 0, the electronic device 1 outputs a reduction signal to reduce the opening of the pressure regulating valve 31, thereby realizing automatic adjustment of the pressure in the first main water supply pipe 3, reducing the process of manual adjustment, and improving efficiency and convenience.

[0048] Furthermore, a second vacuum sensor 32 is installed at the connection between the main water supply pipe 3 and the water inlet of the target water pump 2. This second vacuum sensor 32 can obtain a pressure signal representing the water pressure value input to the target water pump 2. Based on this pressure signal, the electronic device 1 can determine whether the target water pump 2 is in the coupled water supply state. When the water pressure value of the target water pump 2 is greater than 0, indicating that the target water pump 2 is in the coupled water supply state, the electronic device 1 outputs a reduction signal to reduce the opening of the pressure regulating valve 31.

[0049] A foam on / off valve 52 is provided on the foam supply pipe 51. When the vacuum at the low-pressure port of the venturi tube 6 is less than a preset value, the foam liquid in the foam liquid tank 5 meets the requirements for entering the venturi tube 6. At this time, the electronic device 1 outputs an opening signal to open the foam on / off valve 52. The preset value is less than or equal to 0. When the vacuum at the low-pressure port of the venturi tube 6 is greater than or equal to the preset value, the foam liquid in the foam liquid tank 5 does not meet the requirements for entering the venturi tube 6. In this case, the foam on / off valve 52 does not need to be opened. Furthermore, because the foam on / off valve 52 is controlled by a signal output by the electronic device 1, an input device can be provided. The user can actively control the output of a control signal from the electronic device 1 through the input device to control the opening and closing of the foam on / off valve 52. This allows the user to actively control whether to add foam liquid to the main water supply pipe 3, which is highly convenient.

[0050] 1 , a foam induction valve 62 is connected between the inlet of the venturi tube 6 and the outlet of the target water pump 2. This valve 62 is activated in response to a foam induction signal output by the electronic device 1. The foam induction signal can be output when the electronic device 1 determines that the vacuum level at the low-pressure port of the venturi tube 6 is less than a preset value, indicating that the foam in the foam concentrate tank 5 is ready to enter the main water supply pipe 3. The foam induction signal can also be output by the user, allowing the user to actively control whether to add foam concentrate to the main water supply pipe 3.

[0051] In order to maintain a stable fire extinguishing effect, the proportion of foam in the foam-water mixed liquid released from the outlet of the target water pump 2 should also be stable. Furthermore, in order to improve the stability of the foam proportion, a fire foam mixing system coupled with water supply also includes a proportional regulating valve 54 and a water outlet flow meter 21. The water outlet flow meter 21 is arranged at the outlet end of the target water pump 2 and can detect and output a flow signal representing the liquid flow at the outlet end of the target water pump 2; the proportional regulating valve 54 is arranged on the foam supply pipe 51, one end of the proportional regulating valve 54 is connected to one end of the foam switch valve 52, and the other end of the proportional regulating valve 54 is connected to the low-pressure port of the venturi tube 6; the electronic device 1 outputs a regulating signal based on the flow signal to adjust the opening of the proportional regulating valve 54.

[0052] If the foam ratio in the foamy liquid ejected from the outlet of the target water pump 2 is required to be constant, the greater the flow rate at the outlet of the target water pump 2, the greater the opening of the proportional control valve 54, and the smaller the flow rate at the outlet of the target water pump 2, the smaller the opening of the proportional control valve 54. The foam ratio can be determined by a preset reference value in the electronic device 1, that is, the relationship between the opening of the proportional control valve 54 and the flow rate at the outlet of the target water pump 2.

[0053] Furthermore, when the water pressure in the main water supply pipe 3 is high, the water in the main water supply pipe 3 is likely to flow back through the venturi tube 6 into the foam concentrate tank 5. Therefore, a one-way valve 55 is provided on the foam supply pipe 51. The outlet of the one-way valve 55 is connected to the low-pressure port of the venturi tube 6, and the inlet of the one-way valve 55 is connected to the end of the proportional control valve 54 that is not connected to the foam on / off valve 52.

[0054] Furthermore, in order to further reduce the probability of water in the main water supply pipe 3 flowing back into the foam concentrate tank 5, when the vacuum degree at the low-pressure port of the venturi tube 6 is greater than 0, it means that the water pressure in the main water supply pipe 3 is relatively large. At this time, the electronic device 1 outputs a closing signal to close the proportional control valve 54.

[0055] Furthermore, to facilitate monitoring of whether insufficient foam occurs when foam is mixed into the main water supply pipe 3, a first liquid level gauge 57 can be provided in the foam stock liquid tank 5. The first liquid level gauge 57 detects the height of the foam stock liquid in the foam stock liquid tank 5 and can output a liquid level signal to the electronic device 1, which can be read by the user via the electronic device 1 or a display device capable of communicating with the electronic device 1. Furthermore, a foam flow meter 53 can be provided on the foam supply pipe 51 to monitor the status of foam addition into the main water supply pipe 3.

[0056] Between the end of the foam raw liquid tank 5 and the low-pressure port of the venturi tube 6, a foam switch valve 52, a foam flow meter 53, a proportional regulating valve 54 and a one-way valve 55 are sequentially provided.

[0057] Furthermore, after stopping mixing the foam concentrate into the main water supply pipe 3, residual foam concentrate will remain in the foam supply pipe 51, the one-way valve 55, and the proportional control valve 54. To facilitate cleaning of the residual foam concentrate, a cleaning valve 56 is connected between the water outlet of the target water pump 2 and the foam supply pipe 51. One end of the cleaning valve 56 is connected to the water outlet of the target water pump 2, and one end of the cleaning valve 56 is connected to the end of the foam on-off valve 52 connected to the proportional control valve 54. When the cleaning valve 56 is opened, the high-pressure liquid passing through the water outlet of the target water pump 2 can enter the foam supply pipe 51 through the cleaning valve 56 and the proportional control valve 54, thereby cleaning the residual foam concentrate.

[0058] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A fire-fighting foam mixing system coupled with water supply, characterized in that: include: Foam stock liquid tank (5), venturi tube (6), main water supply pipe (3), target water pump (2) and pressure regulating valve (31); One end of the main water supply pipe (3) is connected to the water supply port of the target water pump (2), and the other end of the main water supply pipe (3) is used to connect to a water source; The inlet end of the venturi tube (6) is connected to the water outlet of the target water pump (2), the water outlet end of the venturi tube (6) is connected to the main water supply pipe (3), and the low-pressure port of the venturi tube (6) is connected to the foam raw liquid tank (5) via a foam supply pipe (51); The pressure regulating valve (31) is connected to the main water supply pipe (3) and is capable of regulating the water pressure entering the main water supply pipe (3); It also includes an electronic device (1), wherein the pressure regulating valve (31) is an electrically controlled regulating valve; A first vacuum sensor (61) is provided in the low-pressure port of the venturi tube (6), and the first vacuum sensor (61) is capable of detecting the vacuum degree at the low-pressure port of the venturi tube (6) and outputting a vacuum degree signal; The electronic device (1) obtains the vacuum signal, and when the vacuum at the low-pressure port of the venturi tube (6) is greater than 0, the electronic device (1) outputs a reduction signal to reduce the opening of the pressure regulating valve (31).

2. A fire-fighting foam mixing system coupled with water supply according to claim 1, characterized in that: The foam supply pipe (51) is provided with a foam switch valve (52). When the vacuum degree at the low-pressure port of the venturi tube (6) is less than a preset value, the electronic device (1) outputs an opening signal to open the foam switch valve (52). The preset value is less than or equal to 0.

3. A fire-fighting foam mixing system coupled with water supply according to claim 2, characterized in that: It also includes a proportional regulating valve (54) and a water outlet flow meter (21); The water outlet flow meter (21) is arranged at the water outlet end of the target water pump (2) and is capable of detecting and outputting a flow signal representing the liquid flow at the water outlet end of the target water pump (2); The proportional regulating valve (54) is arranged on the foam supply pipe (51), one end of the proportional regulating valve (54) is connected to one end of the foam switching valve (52), and the other end of the proportional regulating valve (54) is connected to the low-pressure port of the venturi tube (6); The electronic device (1) outputs a regulating signal based on the flow signal to regulate the opening of the proportional regulating valve (54).

4. A fire-fighting foam mixing system coupled with water supply according to claim 3, characterized in that: A one-way valve (55) is provided on the foam supply pipe (51), the water outlet of the one-way valve (55) is connected to the low-pressure port of the venturi tube (6), and the water inlet of the one-way valve (55) is connected to the end of the proportional regulating valve (54) that is not connected to the foam switching valve (52).

5. The fire-fighting foam mixing system coupled with water supply according to claim 3, characterized in that: When the vacuum degree at the low-pressure port of the venturi tube (6) is greater than 0, the electronic device (1) outputs a closing signal to close the proportional control valve (54).

6. The fire-fighting foam mixing system coupled with water supply according to claim 3, characterized in that: A cleaning valve (56) is connected between the water outlet of the target water pump (2) and the foam supply pipe (51), one end of the cleaning valve (56) is connected to the water outlet of the target water pump (2), and one end of the cleaning valve (56) is connected to one end of the foam switch valve (52) connected to the proportional control valve (54).

7. The fire-fighting foam mixing system coupled with water supply according to claim 1, characterized in that: A foam induction valve (62) is connected between the inlet end of the venturi tube (6) and the water outlet of the target water pump (2), and the foam induction valve (62) is opened in response to a foam induction signal output by the electronic device (1).

Images