A butterfly valve with dual-stage flow regulating function and method thereof

Abstract

The invention discloses a butterfly valve with a two-stage flow regulating function and a method thereof. The butterfly valve includes a valve body, a valve core assembly and a driving assembly. The inner ring valve plate and the annular outer ring valve plate; the driving assembly includes the driving shaft with the driving gear on the fixed sleeve, the outer ring shaft with the outer ring gear on the fixed sleeve and the inner ring shaft with the inner gear on the fixed sleeve; the outer ring The valve plate rotates around the shaft of the outer ring, and the valve plate of the inner ring rotates around the shaft of the inner ring; when the driving gear rotates, the teeth on the driving gear first mesh with the teeth of the inner ring gear, and then disengage from the teeth of the inner ring gear. Then mesh with the teeth of the outer ring gear to drive, so that the inner ring valve plate and the outer ring valve plate are opened sequentially. In the case of small flow, only the inner ring valve plate is opened to adjust the flow; in the case of large flow, both the outer ring valve plate and the inner ring valve plate are opened to adjust the flow.

Description

technical field [0001] The invention belongs to the technical field of valves, and in particular relates to a butterfly valve with a two-stage flow regulating function and a method thereof. Background technique [0002] The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. When the butterfly valve is fully opened, it has a small flow resistance. When it is opened between about 30° and 70°, it can also perform sensitive flow control. Therefore, in the field of large-diameter regulation, the application of butterfly valves is very common. Because the "opening-flow" curve of the butterfly valve is basically linear in the flow range of 30% to 75%, the butterfly valve is suitable for flow regulation at medium and high openings. And when the butterfly valve is required to be used to control flow, the working condition of small flow will produce bad working conditions. [00...

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Problems solved by technology

And when the butterfly valve is required to be used to control the flow, the working condition of small flow will cause bad working conditions.

[0003] Therefore, the butterfly control valve cannot work at a small opening because there are sharp changes in flow resistance, flow velocity, and pressure when working at a small opening. If the butterfly control valve is used to work under this working condition, it will The following problems are caused: 1) The opening is small, and the sealing surface of the valve core is close to the throttle port, which damages the sealing surface of the valve core; 2) At this time, the butterfly valve regulating valve has the smallest throttling gap and the largest flow rate, so it is washed by the water flow The most severe, seriously affecting the service life of the valve; 3) When the rapid flow rate and pressure change, it is easy to exceed the stiffness of the valve, resulting in poor stability of the valve and even serious oscillation; 4) For the valve working in the closed state, it will jump Shutdown or jump start phenomenon

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