FR2566092A1 - Device for controlling the flow of fluid with a low noise level. - Google Patents

Abstract

Device for controlling the flow of fluid with a low noise level. The subject of the invention is a device for controlling the flow of fluid with a low noise level comprising a hollow body 1 comprising a first orifice 2 intended to be connected to an upstream pipe 3, a second orifice 4 intended to be connected to a downstream pipe 5, the said body comprising, inside it, a flap 7 which can be moved in translation and capable of coming to shut off one of the said orifices by pressing on its seat 6, characterised in that the volume delimited by the travel of the flap is surrounded by at least one cylindrical metal sheet 10 which is perforated and coated externally with a metal fabric 11, the gas necessarily having to pass through the said fabric in order to pass from one orifice to the other. Application to pressure relief valves and to valves.

Description

Low noise fluid flow control device
The invention relates to a fluid flow control device (gas, vapor, liquid, two-phase mixture, etc.), the operation of which generates a low level of noise.

 By fluid flow control device, is meant either a sectioning member of a fluid line (tap, valve), or a regulating member allowing the adjustment of the flow rate and / or the upstream or downstream pressure in operation generally. continuous (regulator, valve, regulator, etc.), or a safety device which opens for example to the atmosphere when the upstream pressure exceeds a certain threshold (all or nothing operation).

 An object of the present invention is to provide a fluid flow control device whose operation is practically silent.

 In patent No. 81,01578, there has been described a device for silent expansion of pressurized gas comprising a tube having a perforated portion and, around this tube, a metallic fabric wound in several coaxial layers and held by a perforated sheet.

 This device attenuates the noises due to the expansion of the gases; but it's a static device. The Applicant has had the idea of applying the teaching of the aforementioned patent to a dynamic fluid control device, such as a pressure reducing valve or valve.

 The subject of the present invention is a device for controlling fluid flow with a low noise level comprising a hollow body comprising a first orifice intended to be connected to an upstream pipe, a second orifice intended to be connected to a downstream pipe, said body comprising inside a valve movable in translation and capable of closing one of said orifices by pressing on its seat, characterized in that the volume delimited by the stroke of the valve is surrounded by at least one perforated cylindrical sheet coated externally with a metallic fabric, the gas necessarily passing through said fabric to pass from one orifice to the other.

 In a first embodiment, said sheet is fixed, the valve and the sheet constituting a piston-cylinder assembly.

 In another embodiment, said sheet is integral with the valve and constitutes a cylinder, the piston being constituted by the seat of the valve.

 The invention will be better understood from the description below of various embodiments of the invention, with reference to the appended drawing in which - FIG. 1 is a view in axial section of a valve according to a first embodiment of the invention, - Figure 2 is an axial sectional view of a valve according to a second embodiment of the invention.

- Figure 3 is an axial sectional view of a valve according to the invention.

 Figure 1 shows in axial section a valve according to the invention.

 The valve comprises a valve body 1, a first port 2 intended to be connected to an upstream pipe 3 and a second port 4 intended to be connected to a downstream pipe 5.

 The tube 3 is terminated by a chamfered part 6 constituting a seat for a valve 7 provided with a rod 8 with a control not shown (manual mechanical, pneumatic, electric, etc.) and possibly a return spring 9 .

 According to the invention, the volume delimited by the stroke of the valve is surrounded by a perforated sheet 10, itself surrounded by one or more layers 11 of metallic fabric held by a protective sheet.

 In this example, the valve is made so as to constitute a piston sliding in the cylinder with gentle friction.

 The gas coming from upstream must pass through the metallic fabric 11 before escaping downstream.

 Thanks to the diffusion of gases through the fabric, the pressure of the gases is lowered; the downstream pressure depends on the position of the valve 7 in the cylinder 10 and can therefore be adjusted.

 The passage of gases through the tissue modifies the acoustic frequencies generated by the successive detent (s) by moving them towards the high ranges which are inaudible in part (ultrasound). The term fabric here has a very general meaning and designates a set of interlaced, woven, braided, knitted or other metallic threads.

 The size and number of holes in the sheet 10, the thickness and density of the metallic fabric are chosen as a function of the parameters of the gas and in particular of its nature, and the range of operating pressures.

 It is possible, if necessary, to have 2 or 3 sets of perforated sheet 10 fabric 11, concentrically.

In the variant embodiment shown in FIG. 2, the elements common to FIGS. 1 and 2 are given the same reference number
The assembly consisting of the perforated sheet 10, the # metal fabric 11 and the protective sheet 12 is integral with the valve 7.

 The upstream tube 3 is terminated by a collar 15 serving as a seat for the valve. The operation is identical to that of the valve in Figure 1.

 Figure 3 shows a tare spring soup. It comprises a body 20, an upstream opening 21 and a downstream opening 22. A valve 23 can move in a guide cylinder; it can close the upstream orifice 21 which has a seat 25 for the valve.

 The valve is urged to close by a spring 26, calibrated so as to ensure the closure of the orifice 21 for upstream pressures lower than a given calibration pressure.

 The body has inside a perforated tube 27 provided with one or more layers 28 of metallic fabric held by a perforated protective sheet 29.

 The tube is arranged coaxially with the opening 21 and extends from one end of the body to the other so that the gases are forced to pass through the sheet metal 27 - fabric 28 assembly to pass from an orifice to the other.

 The operation of such a soup is particularly silent.

Claims (3)

1 / Low noise fluid flow control device comprising a hollow body (1) comprising a first orifice (2) intended to be connected to an upstream pipe (3), a second orifice (4) intended to be connected to a downstream pipe (5), said body comprising inside a valve (7) movable in translation and capable of closing one of said orifices by pressing on its seat (6), characterized in that the volume delimited by the stroke of the valve is surrounded by at least one perforated cylindrical sheet (10) coated externally with a metallic fabric (11), the gas having to necessarily pass through said fabric to pass from one orifice to the other.  2 / Device according to claim 1, characterized in that said sheet (10) is fixed, the valve (7) of the sheet (10) constituting a piston-cylinder assembly. 3 / Device according to claim 1, characterized in that- said sheet (10) is integral with the valve (7) is a cylinder, the piston being constituted by the seat (15) of the valve.