Porous current-limiting and noise-reducing orifice plate and the current-limiting and noise-reducing device constituted thereof

Abstract

The present invention provides a porous current-limiting and noise-reducing orifice plate and a current-limiting and noise-reducing device made of it. The structure of the multi-hole current-limiting and noise-reducing orifice plate is provided with a flow-limiting hole in the center of the orifice plate, and the rest of the flow-limiting holes are A group of concentric circles are arranged in a ring, and the number of restricting holes located on concentric circles with different radii gradually increases from the inside to the outside. The center to the edge of the orifice plate is arranged in an arithmetic progression. The current limiting and noise reducing device is composed of a pipe section and at least one porous current limiting and noise reducing orifice plate arranged in the pipe section, and connecting flanges are arranged at both ends of the pipe section. Compared with the conventional porous current-limiting and noise-reducing orifice plate, the present invention has improved noise-reducing capability and significantly reduced pressure loss.

Description

technical field [0001] The present invention relates to the technical field of reducing pipeline medium pressure and noise, in particular to flow-limiting orifice technology, in particular to a multi-hole flow-limiting and noise-reducing orifice that needs to simultaneously reduce pressure and noise in large-pressure-drop pipelines and its Constituted current limiting noise reducer. Background technique [0002] The fluid flows through the porous orifice plate with a suddenly reduced cross-section in the pipeline, and the fluid is partially blocked, which will cause the pressure of the fluid behind the plate to decrease and the flow rate to increase. There is a certain pressure difference between the front and back of the orifice plate. For a certain aperture, the flow rate through the orifice plate increases with the increase of the pressure difference between the front and back of the orifice plate. The flow velocity at the hole reaches the speed of sound. At this time, n...

AI Technical Summary

Problems solved by technology

For the conventional multi-hole flow-limiting orifice, on the one hand, after the fluid flows through the multi-hole flow-limiting orifice, the flow rate changes abruptly, first increases suddenly and then decreases rapidly to a stable value. The relationship between the static pressure energy and the kinetic energy described in the equation shows that the static pressure energy at the center of the orifice plate behind the plate is the smallest, so that the flow stream converges to the center of the orifice plate as a whole, resulting in the uneven velocity distribution behind the plate; on the other hand, due to the There is a large number of vortices in the recirculation zone in the gap, resulting in a large pressure loss

Large changes in pressure and velocity, uneven distribution and the existence of a large number of vortices make the overall flow stability of the medium behind the plate poor

[0004] In addition, the conventional multi-hole flow-restricting orifice also has the defect of high decibel noise behind the plate

The high decibel noise is mainly due to the formation of restricted multiple jets in the pipeline after the fluid flows through the porous orifice. After the jet exits from the orifice, a discontinuous velocity fluctuation is formed between the core area of ​​the jet and the surrounding static fluid. According to the double jet theory , after the fluid flows through the porous orifice plate, a converging zone is formed between multiple jets, and a recirculation zone between jets is formed in the converging zone, and a near-wall recirculation zone is formed between each jet and the wall, and there are a large number of vortices in the two recirculation zones , the speed difference between the high-speed jet zone and the two backflow zones behind each center hole behind the plate is large, and there is a huge flow shear force at the junction of the two zones, resulting in relatively strong flow-induced noise and pipeline vibration, and then Cause fatigue damage to pipeline equipment and environmental noise pollution

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