Method and system for rapidly leading foam of foam pump of compressed air foam system

Abstract

The invention discloses a method and a system for quickly leading foam of a foam pump of a compressed air foam system, the method is as follows: an electromagnetic control emptying valve which is opened and closed under the control of a PLC (Programmable Logic Controller) is mounted at an outlet of the foam pump of the compressed air foam system, when the compressed air foam system is started, the PLC opens the electromagnetic control emptying valve to enter emptying time; and after the emptying time is up, the PLC closes the electromagnetic control emptying valve, and the foam pump pumps the foam to a mixing pipeline of the compressed air foam system, so that the mixing of the water, the foam and the air is completed.

Description

Technical Field

[0001] This invention belongs to the field of fire protection equipment technology, specifically relating to a method and system for rapidly introducing foam using a foam pump in a compressed air foam system. Background Technology

[0002] Compressed air foam systems (CAFS) are highly efficient fire suppression systems that extinguish fires by mixing water, foam, and compressed air in a specific ratio to create a homogeneous and stable foam mixture. The core requirement is that the water, foam, and air maintain pressure balance and flow rate matching during mixing.

[0003] In existing technologies, foam delivery pumps mostly employ plunger pumps or gear pumps. The advantage of these pumps is that the flow rate and rotational speed have a linear relationship, making it easy to control the flow rate through rotational speed, and the outlet pressure has minimal impact on the flow rate. However, they have a significant drawback: when there is high back pressure at the foam pump outlet (e.g., the system is already running and there is high pressure in the mixing pipeline), the pump cannot effectively draw up foam, resulting in air at the pump inlet. The foam pump runs dry because it cannot draw in air, which not only prevents normal foam injection but also easily causes dry wear damage to the pump body. Commonly used solutions include: one is to pour foam into the foam pump inlet to ensure it is full before the pump can operate normally; another is to run the foam pump even when there is no pressure at the outlet, drawing up foam until it injects it into the mixing pipeline, and then starting the water pump and air compressor, etc. These methods complicate system operation, lengthy the entire process, and place high demands on operators, which is very detrimental to fire fighting. Summary of the Invention

[0004] This invention aims to overcome the shortcomings of the prior art and provide a method and system for rapidly induced foam using a foam pump in a compressed air foam system.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows: The method for rapidly introducing foam into the compressed air foam system involves installing an electromagnetically controlled vent valve at the outlet of the foam pump, which is controlled by a PLC. When the compressed air foam system is started, the PLC opens the electromagnetically controlled vent valve to initiate the venting time. After the venting time is up, the PLC closes the electromagnetically controlled vent valve, and the foam pump pumps the foam to the mixing pipeline of the compressed air foam system to complete the mixing of water, foam, and air.

[0006] Preferably, the evacuation time is the time required for the foam pump outlet to produce a stable foam output.

[0007] More preferably, the time to achieve stable foam output from the foam pump outlet is a preset time T0 in the PLC program, wherein the time T0 is greater than the average time T required to achieve stable foam output from the foam pump outlet more than 100 times.

[0008] More preferably, T0 > 1.5T.

[0009] Preferably, the time to achieve a stable foam output from the foam pump outlet is the time when pressure is detected at the foam pump outlet.

[0010] The present invention also provides a compressed air foam system for implementing the above method. The compressed air foam system includes a foam pump and a compressed air foam mixing pipeline. The inlet of the foam pump is connected to a foam container, and the outlet of the foam pump is connected to the compressed air foam mixing pipeline through a foam delivery pipeline. An electromagnetically controlled vent valve is provided at the outlet of the foam pump, and the electromagnetically controlled vent valve is connected to a PLC.

[0011] Preferably, the electromagnetically controlled vent valve is connected to the outlet of the foam pump via a three-way valve.

[0012] Preferably, the electromagnetically controlled vent valve is connected to the foam delivery pipeline via a tee.

[0013] Preferably, the compressed air foam system further includes a fire pump and an air compressor, wherein the fire pump is connected to the compressed air foam mixing pipeline via a pressurized water delivery pipeline, and the air compressor is connected to the compressed air foam mixing pipeline via a compressed air delivery pipeline.

[0014] More preferably, the foam delivery pipe and the compressed air delivery pipe are equipped with one-way valves.

[0015] More preferably, a pressure detector is provided at the outlet of the foam pump.

[0016] The present invention will be further described below: This invention adds an electromagnetically controlled vent valve to the outlet of a foam pump. A PLC program controls this vent valve to release air from the foam pump outlet. When the vent valve opens and there is no pressure at the foam pump outlet, the foam pump vents. After the foam pump has finished venting, the vent valve closes. (That is, the venting control logic is that a stable foam output from the foam pump outlet indicates that the foam pump has completed venting. There are two judgment logics: one is to count the venting completion time of more than 100 foam pump cycles, and the program sets the venting time to be greater than 1.5 times the average of the counted times to ensure that the foam pump completes venting each time; the other is to detect the foam pump outlet pressure. If there is pressure, it proves that the foam pump is producing foam, and the system has completed venting.) Once the foam pump outlet produces foam, it can be normally injected into high-pressure water. During operation, when the foam system is started, the electromagnetically controlled vent valve automatically opens, the foam pump vents, and the program sets the venting time. After the venting time is reached, the electromagnetic valve closes, and the foam pump injects the foam solution into the high-pressure water, completing the mixing of water, foam, and air. This invention can fully automate the operation of the foam system, reducing human error during manual operation.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention enables the foam pump to start and operate normally at any time, regardless of the outlet high pressure.

[0018] 2. It solves the problems of cumbersome operation steps of foam pumps in existing compressed air foam systems, as well as the drawbacks of foam pumps being easily damaged when they are not working.

[0019] 3. It solves the problem of foam pumps without a venting device being unable to work stably.

[0020] 4. It solves the last link in the automated operation of the compressed air foam system, enabling fully automated operation of the entire process.

[0021] In summary, this invention solves the adverse effects of high pipeline pressure on the normal foam extraction of the foam pump, allowing the foam pump to switch from suction to normal foam injection into the mixing pipeline. The smooth operation of the plunger pump pipeline is controlled by a PLC program, reducing human interference during operation and achieving automation of the entire compressed air foam system process. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the compressed air foam system described in this invention; Figure 2 This is a logic diagram of the electromagnetically controlled vent valve in the method of the present invention.

[0023] In the diagram: 1. Foam pump; 2. Compressed air foam mixing pipeline; 3. Foam container; 4. Foam delivery pipeline; 5. Electromagnetically controlled vent valve; 6. Fire pump; 7. Air compressor; 8. Pressurized water delivery pipeline; 9. Compressed air delivery pipeline; 10. Check valve. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 See Figure 1 The compressed air foam system includes a foam pump 1 and a compressed air foam mixing pipe 2. The inlet of the foam pump 1 is connected to a foam container 3, and the outlet of the foam pump 1 is connected to the compressed air foam mixing pipe 2 through a foam conveying pipe 4. An electromagnetically controlled vent valve 5 is provided at the outlet of the foam pump 1, and the electromagnetically controlled vent valve 5 is connected to a PLC.

[0026] The electromagnetically controlled vent valve 5 is connected to the outlet of the foam pump 1 via a tee, or the electromagnetically controlled vent valve 5 is connected to the foam delivery pipeline 4 via a tee.

[0027] The compressed air foam system also includes a fire pump 6 and an air compressor 7. The fire pump 6 is connected to the compressed air foam mixing pipeline 2 through a pressurized water delivery pipeline 8, and the air compressor 7 is connected to the compressed air foam mixing pipeline 2 through a compressed air delivery pipeline 9.

[0028] One-way valves 10 are provided on the foam delivery pipe 4 and the compressed air delivery pipe 9.

[0029] Example 2 The method for rapidly introducing foam into the compressed air foam system involves installing an electromagnetically controlled vent valve at the outlet of the foam pump, controlled by a PLC. When the compressed air foam system is started, the PLC opens the vent valve, initiating a venting period. After the venting period, the PLC closes the vent valve, and the foam pump delivers foam to the mixing pipeline of the compressed air foam system, completing the mixing of water, foam, and air. The venting period is the time required to achieve a stable foam output from the foam pump outlet. This stable foam output time is a preset time T0 in the PLC program, where T0 is greater than the average time T required to achieve a stable foam output from the foam pump outlet after more than 100 statistical iterations, and T0 > 1.5T.

[0030] Example 3 The compressed air foam system includes a foam pump 1 and a compressed air foam mixing pipe 2. The inlet of the foam pump 1 is connected to a foam container 3, and the outlet of the foam pump 1 is connected to the compressed air foam mixing pipe 2 through a foam delivery pipe 4. An electromagnetically controlled vent valve 5 is provided at the outlet of the foam pump 1, and the electromagnetically controlled vent valve 5 is connected to a PLC.

[0031] The electromagnetically controlled vent valve 5 is connected to the outlet of the foam pump 1 via a tee, or the electromagnetically controlled vent valve 5 is connected to the foam delivery pipeline 4 via a tee.

[0032] The compressed air foam system also includes a fire pump 6 and an air compressor 7. The fire pump 6 is connected to the compressed air foam mixing pipeline 2 through a pressurized water delivery pipeline 8, and the air compressor 7 is connected to the compressed air foam mixing pipeline 2 through a compressed air delivery pipeline 9.

[0033] One-way valves 10 are provided on the foam delivery pipe 4 and the compressed air delivery pipe 9.

[0034] A pressure detector is installed at the outlet of the foam pump.

[0035] Example 4 The method for rapidly introducing foam into the compressed air foam system involves installing an electromagnetically controlled vent valve, controlled by a PLC, at the outlet of the foam pump. When the compressed air foam system is started, the PLC opens the vent valve, initiating a venting period. After the venting period, the PLC closes the vent valve, and the foam pump delivers foam to the mixing pipeline of the compressed air foam system, completing the mixing of water, foam, and air. The venting period is defined as the time required to achieve a stable foam output from the foam pump outlet. This stable foam output time is also defined as the time it takes to detect pressure at the foam pump outlet.

Claims

1. A method for rapidly introducing foam using a foam pump in a compressed air foam system, characterized in that, The method involves installing an electromagnetically controlled vent valve, controlled by a PLC, at the outlet of the foam pump in a compressed air foam system. When the compressed air foam system is started, the PLC opens the electromagnetically controlled vent valve to initiate the venting time. After the venting time is up, the PLC closes the electromagnetically controlled vent valve, and the foam pump pumps foam into the mixing pipeline of the compressed air foam system to complete the mixing of water, foam, and air.

2. The method for rapidly priming foam in a compressed air foam system as described in claim 1, characterized in that, The evacuation time is the time required for the foam pump to produce a stable foam output.

3. The method for rapidly priming foam in a compressed air foam system as described in claim 2, characterized in that, The time to achieve a stable foam output from the foam pump outlet is the time T0 preset by the PLC program, and the time T0 is greater than the average time T required to achieve a stable foam output from the foam pump outlet more than 100 times.

4. The method for rapidly priming foam in a compressed air foam system as described in claim 3, characterized in that, The T0 is greater than 1.5T.

5. The method for rapidly priming foam in a compressed air foam system as described in claim 2, characterized in that, The time when a stable foam output is achieved at the foam pump outlet is the time when pressure is detected at the foam pump outlet.

6. A compressed air foam system for implementing the method of any one of claims 1 to 5, characterized in that, The compressed air foam system includes a foam pump and a compressed air foam mixing pipeline. The foam pump inlet is connected to a foam container, and the foam pump outlet is connected to the compressed air foam mixing pipeline through a foam delivery pipeline. An electromagnetically controlled vent valve is provided at the foam pump outlet, and the electromagnetically controlled vent valve is connected to a PLC.

7. The compressed air foam system as described in claim 6, characterized in that, The electromagnetically controlled vent valve is connected to the outlet of the foam pump via a three-way valve.

8. The compressed air foam system as described in claim 6, characterized in that, The electromagnetically controlled vent valve is connected to the foam delivery pipeline via a tee.

9. The compressed air foam system as described in claim 6, characterized in that, The compressed air foam system also includes a fire pump and an air compressor. The fire pump is connected to the compressed air foam mixing pipeline via a pressurized water delivery pipeline, and the air compressor is connected to the compressed air foam mixing pipeline via a compressed air delivery pipeline.

10. The compressed air foam system as described in claim 9, characterized in that, One-way valves are installed on the foam delivery pipeline and the compressed air delivery pipeline.

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