Flow Measurement Principle of Multijet Jet Rotary Vane Cold Water Meter

The Multijet Jet Rotary Vane Cold Water Meter is a commonly used device for measuring flow in both civil and industrial water supply systems. Its main advantages are its compact structure and high sensitivity to low-flow measurements, which allow for accurate tracking of total cold water consumption. The accuracy of flow measurement is crucial for the economic interests of both water suppliers and users, as it also impacts energy consumption optimization and the scheduling of pipe networks within water supply systems.

Core Principle of Flow Measurement for Multijet Jet Rotary Vane Cold Water Meter

1. Structural Foundation: Collaborative Design of Multijet and Rotary Vane

The core internal structure of the water meter includes a flow splitter, multiple sets of jet orifices, a rotary vane impeller, and a counting mechanism. The flow splitter evenly distributes the cold water flowing through the water meter to multiple jet orifices, forming multiple parallel jets. The jet orifices are arranged obliquely, and the sprayed water flow generates circumferential thrust on the rotary vane impeller to drive it to rotate. The rotation angle of the impeller has a fixed proportional relationship with the volume of water flowing through. Through the gear transmission mechanism, the rotational motion is transmitted to the counting mechanism, which finally presents the cumulative flow in digital form.

2. Measurement Logic: Conversion Relationship Between Flow Velocity, Rotational Speed, and Flow Rate

Flow measurement essentially converts the kinetic energy of water flow into mechanical rotational motion and then realizes flow accumulation through mechanical transmission. Its core logic satisfies the formula: Q = k×n (Q is instantaneous flow rate, k is water meter constant, n is impeller rotational speed). When cold water passes through the jet orifices, the higher the flow velocity, the stronger the thrust on the impeller, and the higher the impeller rotational speed. Within the rated flow range, the rotational speed is linearly related to the flow velocity, ensuring linear accuracy in flow measurement. The design purpose of the multijet structure is to reduce the impact of water-flow disturbances on the impeller's rotational stability through the synergistic effect of multiple water jets and to improve measurement sensitivity under low-flow conditions.

3. Functional Mechanism of Key Components

1. Flow splitter: Adopts a streamlined design to achieve uniform flow distribution, avoid sudden changes in local flow velocity, and ensure consistent flow distribution among each jet orifice.

2. Jet Orifices: The size and angle of the orifices are carefully calibrated to control the direction and speed of the water jet. This calibration directly impacts the rotational efficiency of the impeller.

3. Rotary Vane Impeller: Constructed from lightweight and high-strength materials, the blades are angled to align with the direction of the jet. This design ensures that the thrust generated by the water flow is efficiently converted into rotational kinetic energy.

4. Counting mechanism: Through gear reduction transmission, the high-speed rotation of the impeller is converted into the low-speed rotation of the counting disc, realizing the accumulation and display of flow rate.

The core of flow measurement for the Multijet Jet Rotary Vane Cold Water Meter is to drive the rotary vane to rotate through multijet, realizing the linear conversion between flow velocity and flow rate. Its measurement accuracy depends on the collaborative matching of structural design, manufacturing process, and operating conditions.