The mechanical pump-in proportional mixing device is a flow balance proportional mixing device. Driven by the fire-fighting water flowing in the pipeline, the water turbine drives the foam liquid pump to extract the foam liquid in the atmospheric pressure tank and pump it into the main fire-fighting pipeline. Through the matching of structural parameters inside the water turbine and the foam liquid pump, the flow of water and the flow of foam liquid are balanced to achieve constant ratio mixing. The mechanical pump-in proportional mixing device is small in size, small in floor space, accurate in mixing ratio control, and does not require external power supply or diesel engine.

　　The working principle of PHP mechanical pumping type:

　　1. Mixing principle

　　When the fire-fighting water flows through the proportional mixing device, it drives the water turbine to rotate under the action of hydraulic force. The water turbine outputs the rotating torque to the foam liquid pump and drives it to run. The foam liquid pump absorbs the foam liquid in the atmospheric pressure storage tank, and injects it into the fire water main pipeline under pressure to achieve constant proportion mixing.

　　The interior of the water turbine is a fixed-volume rotor structure, and the volume of water flowing through it for one rotation is a fixed value V1. The foam liquid pump adopts a plunger pump, which is a positive displacement pump, and the volume of the foam liquid output after one rotation is a fixed value V2. The water turbine and the foam liquid pump are connected through a coupling to ensure that the speeds of the two are synchronized. Theoretically, V1:V2=fixed value. Through the optimized design of the internal cavity structure, V1:V2=97:3, meeting the requirement of 3% mixing ratio.

　　2. Performance characteristics

　　The design principle of the product itself determines the performance characteristics of the product.

　　1) Action response is fast. When the fire water flows through the turbine, the foam liquid pump is driven to work without lag time;

　　2) The mixing ratio is stable. The flow rate is only related to the volume of fluid output per revolution, and is less affected by changes in fire water pressure and flow in the pipeline;

　　3) Driven by water power, no need to provide additional power supply or diesel engine power;

　　4) The foam liquid is stored in an atmospheric tank, which can be added at any time during use without a pressure vessel;

　　5) Suitable for various foam liquids with different viscosities;

　　6) The device is small in size and occupies a small area;

　　7) It has a wide range of applications and can be applied to the mixing of foam liquid in fire trucks, ships or fixed foam systems;

　　8) The internal structure of the water turbine is complex, the cavity volume and surface design are difficult, and the processing and assembly precision is high.