FR2779247A1 - Pneumatically controlled reducing valve for gas bottles used in medical work and welding - Google Patents

Abstract

Gas stored in a bottle (31) passes through a first internal fixed ratio reducing valve (30) before entry into a second reducing valve (30') input chamber (2). The gas then passes through a spring loaded valve (9,10,25) to an output chamber (3) and storage (39). A moving wall (16) attached to the valve (10) defines a pneumatic control compartment (4) whose pressure is adjusted by input and output valves (20,21) and a manometer (35)

Description

The present invention relates to a fluid expander assembly under

  pressure, especially pressurized gas, and a pressurized gas cylinder

  equipped with such a regulator assembly.

  Usually industrial gases, such as welding gases or medical gases, are stored in pressure vessels, particularly in

pressurized gas cylinders.

  Inside these pressure vessels, the fluid can be, as the case may be, in the gaseous state, liquefied

or dissolved.

  In general, the pressure of the fluid inside the pressure vessel is much higher than the working pressure of the fluid and it is therefore necessary to carry out an expansion, that is to say a decompression of the fluid , up to its operating pressure. By way of example, mention may be made of the case of oxygen which is commonly compressed in gas cylinders at a pressure of the order of 2.107 Pa, for example, while gaseous oxygen is used, in welding operations, for example, at pressures of

around 106 Pa.

  Usually, the expansion of a compressed fluid is carried out by means of a regulator arranged on the container of pressurized fluid, which regulator makes it possible to control the opening and the closing of the passage of gas from the container under pressure towards the outside of this and therefore the expansion of the gas from its storage pressure in the pressure container to a pressure of use or distribution for example. In general, the regulator assemblies also comprise connection means making it possible to ensure the filling of said container with gas under pressure, means for displaying the pressures and / or fluid flow rates, and safety means making it possible to overcome any trigger system failure or any bad

use of it.

  In a manner known per se, to ensure the relaxation of the fluid under pressure, it is possible either to separate the operating members, that is to say in particular, the opening / closing valve, the valves or valves, and the detent, such as the detent valve (s), or use the detent valve to ensure

both functions at the same time.

  When the expansion valve is used to perform these two functions, said valve is usually coupled to a first system operating in all or nothing, so as to crush said valve on its seat when closing and to a second system of regulation making it possible to move said valve from its seat by the distance necessary to ensure the required flow and

  the desired pressure, upon opening.

  Currently, all pressure regulators of pressurized gas cylinders known to date, use to ensure the expansion, a valve and a piston or a membrane subjected, on one side, to the outlet pressure of the gas leaving the pressurized bottle and, on the other side, to the reverse thrust of a spring compressed by a screw or the like. Such regulators are described in particular in the

  documents FR-A-2735209, EP-A-275242, EP-A-308875, DE-A-

  3441348, US-A-5009249, EP-A-467769, EP-A-443283 and LU-A-

86802.

  However, the assembly formed by the compression spring, the screw for adjusting the compression of said spring and the operating member for said screw is particularly heavy and bulky and must meet strict requirements in terms of security: captive screw, tightening limit stop, adjusted to a

  maximum pressure (see standard EN585) ...

  Furthermore, this assembly offers ergonomics which may be satisfactory and which can be difficult to maneuver and manipulate in certain cases, forcing the user to have recourse to means or tools which are unsuitable for maneuvering said control members, which can

  causes deterioration of said operating members.

  In addition, the direction of operation of the screw operating member often leads to confusion with the valve function since, unlike a conventional valve, manipulation in the direction of tightening results in a larger opening of the valve and

not a closure of it.

  In addition, for safety reasons, it is generally recommended that users carry out a total relaxation of the spring when closing the bottle to avoid too sudden arrival of gas under

  pressure on the valve open on opening.

  However, since this recommendation is not always followed, in practice there is repeated impact, in particular on the closing valve, thus generating faster than expected wear of the latter and therefore

more frequent replacement.

  The object of the present invention is therefore to overcome the problems and drawbacks of the regulators of the prior art by proposing a pressure regulator assembly for pressurized fluid, in particular for a container for pressurized fluid, having improved ergonomics, reliability and safety, and a reduced size, which regulator assembly does not implement a screw system

  and detent spring of the prior art.

  In other words, the object of the present invention is to propose an improved regulator assembly compared to the regulator comprising screw and spring systems.

relaxation of the prior art.

  The present invention therefore relates to a pressurized fluid expander assembly, in particular for a pressurized fluid container, comprising at least one main gas expansion chamber comprising at least one inlet pressure compartment, an outlet pressure compartment and a control pressure compartment, said inlet pressure compartment and said outlet pressure compartment communicating by expansion means, and said outlet pressure compartment and said control pressure compartment being

  separated by at least one movable wall.

  Depending on the case, the regulator assembly according to the invention may include one or more of the following characteristics: - said expansion means comprise a relaxation orifice and closure means and in that said movable wall cooperates with said means shutter so as to at least partially close said expansion orifice as a function of a predetermined and adjustable control pressure prevailing in the control pressure compartment; - It further comprises pressure regulation means making it possible to adjust the control pressure prevailing in the control pressure compartment; - Said control pressure compartment comprises at least one gas inlet orifice and at least one gas outlet orifice, the gas inlet orifice communicating with a pressure control circuit controlled by an inlet valve gas; - the gas outlet orifice is controlled by a gas outlet valve; - the gas inlet and outlet valves are valves operated by manual pressure; - The inlet pressure compartment has at least one gas supply orifice connected to a gas supply circuit; - the pressure control circuit is connected to the gas supply circuit; - the shutter means comprise a valve subjected to a tension force by a spring means; - It further comprises means for pre-expansion of pressurized fluid; - The means for pre-expansion of pressurized fluid are connected to the upstream part of the gas supply circuit terminating in the main gas expansion chamber; - The means for pre-expansion of pressurized fluid or first expansion stage are contained by the bottle or the pressure container on which the regulator assembly is mounted; - It further comprises fixing means allowing the mounting of the regulator assembly on a container of pressurized gas, in particular a gas bottle; - It includes means for measuring flow and / or pressure, such as pressure gauges or similar means; - It includes flow limiting means, such as a flow limiter, arranged on the pressure control circuit, preferably between the gas inlet valve and the gas inlet orifice; - It includes means for controlling fluids, such as non-return valves or similar means; - It includes safety means, such as a pressure limiter, preferably said safety means are arranged on the pressure control circuit, advantageously between the connection point between the gas supply circuit and said control circuit pressure and gas inlet valve; the gas outlet orifice is connected to a gas evacuation circuit connected to the atmosphere, so as to allow downward regulation of the pressure prevailing in the control pressure compartment; - the outlet pressure compartment has an orifice opening into a gas line at operating pressure, preferably the gas circuit at operating pressure includes safety means, such as a

safety valve.

  The present invention also relates to a container of pressurized fluid, in particular a bottle of pressurized gas, characterized in that it is equipped with a regulator assembly according to the invention, preferably the regulator assembly according to the invention is incorporated. in a protective cover to prevent shocks

direct on the regulator assembly.

  The present invention will now be described in more detail using embodiments given by way of illustration, but not limitation and with reference to

annexed diagrams.

  FIG. 1 represents a diagram of a first embodiment of a pressure reducer assembly according to the invention, on which a gas expansion device has been shown diagrammatically

according to the invention.

  More specifically, we see a gas cylinder 31 containing a high pressure gas, for example oxygen at a pressure of 2.107 Pa, which cylinder 31 is equipped with a gas pressure regulator assembly according to

  the invention with two expansion stages 30 and 30 '.

  The dimensions and architecture of the first expansion stage 30 make it possible to incorporate it directly inside the cylinder 31 of pressurized gas, which offers a double advantage, namely to save space and weight given that, in this case, the first expansion stage 30 does not need to be incorporated into a resistant body or protective structure, since the latter is protected by the envelope of the bottle 31. A pressure gauge 34 allows the high pressure prevailing in the bottle 31 to be constantly monitored, which manometer at its pressure tap arranged upstream of

the relaxation stage 30.

  The second expansion stage 30 ', arranged outside the bottle 31, comprises a main gas expansion chamber 1 comprising 3 compartments 2, 3, and 4, namely a compartment 2 at inlet pressure, a compartment 3 with outlet pressure and a compartment 4 to

control pressure.

  More specifically, the gas having undergone a pre-expansion in the first expansion stage 30, for example a pre-expansion of a high pressure of 2.107 Pa to an average pressure of 2.106 Pa, is conveyed via a supply circuit 12 of pressurized gas medium to compartment 2 at inlet pressure communicating with compartment 3 at outlet pressure, that is to say at low pressure, by means of expansion means 9, 10 and 25, comprising a valve 10 detent subjected to a tension force by a spring means 25 and a detent orifice 9 allowing the passage of gas at medium pressure from said compartment 2 towards the

  compartment 3 with outlet pressure.

  In order to adjust or adjust the control pressure prevailing in the compartment 4, the movable wall 16 separating the outlet pressure compartment 3 and the control pressure compartment 4 cooperates with closure means 10,25 so as to more or less shut off the expansion port 9 and therefore vary the flow of gas capable of passing through said expansion port 9, by undergoing expansion therein to a low pressure or outlet pressure, for example a

pressure of the order of 2.105 Pa.

  A pressure control circuit 22, controlled by an inlet valve 20, opens into the control pressure compartment 4, via the orifice 14. This pressure control circuit 22 routes gas at inlet pressure, c that is to say at medium pressure, sensed downstream of the first expansion stage 30, into the compartment 4 at control pressure, so as to allow an adjustment of the pressure in said compartment 4 at control pressure up to pressure

  desired corresponding to a given level of relaxation,

  that is to say a more or less significant obturation of

  the expansion orifice by the closure means 10 and 25.

  Preferably, a flow limiter 41 is arranged

  between the inlet valve 20 and the inlet port 14.

  Conversely, a gas outlet orifice 15 makes it possible to evacuate part of the pressurized gas contained in the compartment 4 at control pressure, via a gas evacuation circuit 26 controlled by a gas outlet valve 21 with pneumatic manual controls, which outlet valve 21 can be connected either to the atmosphere or to the low pressure gas outlet 39, by means of a gas circuit which may include a

  or more non-return valves 37.

  Again, it is possible or even desirable to include on the gas discharge circuit 26 a

flow limiter 20 '.

  Optionally, in order to increase the safety of the regulator assembly according to the invention, it is possible to incorporate into the gas discharge circuit 26 a safety circuit 26 ′ comprising an emergency stop means 38 , such as an emergency stop valve, so as to overcome

  any malfunction of valve 21.

  According to a first embodiment, the actuation of the emergency stop means 38 makes it possible to obtain an immediate stop of the expansion and therefore of the gas flow rate within the

second 30 'relaxation stage.

  This type of operation is preferably used when the priority is to ensure a total shutdown of the gas supply, for example during a welding operation, so as to offset any risk for the operator. According to a second embodiment, the actuation of the emergency stop means 38 makes it possible to ensure a non-zero supply greater than a predetermined threshold. This type of operation is particularly suitable for the medical field where the patient must always be supplied with a respiratory gas mixture. After expansion, the gas at outlet pressure or low pressure is discharged from the outlet pressure compartment 3 through a gas outlet orifice 13 opening into a circuit 23 for outlet of gas at low pressure, connected to the

low pressure outlet 39.

  To control the pressure of the gas leaving compartment 3 at outlet pressure, a bypass circuit 24 is arranged on the outlet circuit 23, which bypass circuit 24 is connected, on the one hand, to a pressure gauge for controlling the low pressure and, on the other

  hand, to a safety valve 36.

  In addition, in general, the quality of the expansion of a gas is a function of the ratio between the surface of the expansion valve and the surface of the piston or

  the membrane used for said expansion.

  Thus, in a double-stage expansion valve according to the invention, the first expansion stage 30 makes it possible to considerably reduce the differences in gas supply pressure of the second expansion stage 30 ′ and also makes it possible to reduce the ratio of the sections, in particular of the relief valve surface 10, while retaining high flow performance in

  now, moreover, a reduced bulk.

  In addition, it is understood that the first stage 30 of

  regulator delivers a gas at fixed medium pressure, that is

  say not adjustable, and the second expansion stage 30 'delivers a low pressure gas or outlet pressure of adjustable value by means of a pneumatic control; the preset pressure setpoint being obtained by means notably of the gas inlet valve 20 controlling the passage of gas at medium pressure from the gas supply circuit 12 into the compartment 4 to

control pressure.

  To lower the pressure setpoint in the control pressure compartment 4, it suffices to actuate the gas outlet valve 21 which allows the gas to be evacuated and therefore the pressure exerted

  in compartment 4 at control pressure.

  The gas inlet and outlet valves 20 and 21, respectively, may also be proportional type valves ensuring rapid adjustment by wide opening at the start of their actuation and then precise by weak opening at the end of actuation; such

  valves being known to those skilled in the art.

  The valves 20 and 21 controlling the inlet and the outlet, respectively of the gases contained in the compartment 4 at control pressure, can be positioned where desired on the regulator, unlike the bodies known from the prior art, in particular screw members the mechanics of which implies their arrangement in the axis of the control screw and of the spring, that is to say perpendicular to the piston or to the diaphragm, so as to be in the axis of the valve or the use of a complex mechanism of references, articulations, connecting rods ... FIG. 2 represents a diagram similar to that of FIG. 1, with the exception of the fact that a safety pressure limiter 50 has been arranged on the pressure control circuit 22, upstream of the gas inlet valve 20, so as to limit the pressure of the gas entering the control pressure compartment 4 to a predetermined maximum value, for example to a value of 106 Pa. Figure 3 shows diagrammatically an embodiment similar to that of FIG. 1, except that, according to FIG. 3, a safety valve 51 has been fitted on the pressure control circuit 22 upstream of the inlet valve of gas 20, so as to overcome any possible overpressure of gas in said pressure control circuit 22 and thus avoid any untimely overpressure inside the compartment 4 at pressure of

control.

  FIG. 4 represents an embodiment analogous to that of FIG. 1 and combining the variants of FIGS. 2 and 3, namely that the pressure control circuit 22 comprises, upstream of the gas inlet valve 20, a safety pressure relief valve 50 and a valve

51 security.

  FIG. 5 represents another embodiment of the regulator according to the invention

  partially similar to that of Figure 1.

  More specifically, FIG. 5 shows diagrammatically a regulator according to the invention comprising only a single expansion stage 30 ′ comprising, as in the case of FIG. 1, a relaxation chamber 1 divided into three compartment 2,

3 and 4.

  The high pressure gas from the bottle 31 is conveyed, via a high pressure gas circuit 12, to compartment 2 at inlet pressure, on the one hand, and to compartment 4 at control pressure, d on the other hand, in order to allow an adjustment of the pressure in

  said compartment 4 at control pressure.

  Note that a safety pressure limiter 50 has been arranged on the pressure control circuit 22 in a manner similar to the embodiment of FIG. 2, which makes it possible to control the maximum pressure of the gas sent to said compartment 4 at control pressure. The embodiment of Figure 5 is particularly well suited to certain industrial fluids, such as acetylene (C2H2), which are stored in gas cylinders at a storage pressure higher than their operating pressure but low enough to do not require pre-stretch,

  as in the embodiments of FIGS. 1 to 4 below

  before. Indeed, it is usual to store acetylene in gas cylinders 31 at a maximum pressure of the order of 20.105 Pa to about 25.105 Pa, that is to say at a pressure of the order of that obtained after predetent

of an oxygen or nitrogen type gas.

  Figures 6 and 7 show yet another embodiment of a pressurized fluid expander assembly, according to the invention which expander assembly includes, as shown in Figure 1, a first expansion stage 30 and a second stage 30 ' expansion, the second expansion stage 30 'comprising a main expansion chamber 1 divided, this time into 4 compartments, namely a compartment 2 at inlet pressure o into which is introduced the gas having undergone a pre-expansion in the first pressure stage 30, a compartment 3 at outlet pressure communicating with compartment 2 at inlet pressure by means of expansion means 9, 10, 25, a compartment 5 at atmospheric pressure communicating with the atmosphere, via a port 5 'for atmospheric pressure, and a control pressure compartment 4 supplied with gas having undergone a pre-expansion, via the control circuit 22

  pressure controlled by the inlet valve 20.

  The compartment 3 at outlet pressure and the compartment 5 at atmospheric pressure are separated by a movable wall 16 ′, while the compartment 5 at atmospheric pressure and the compartment 4 at control pressure are separated by a second movable wall 16, said walls mobile 16 and 16 'cooperating with said closure means 10, 25 so as to at least partially close the expansion orifice 9 as a function of a predetermined and adjustable control pressure prevailing

  in the control pressure compartment 4.

  According to this embodiment, the pilot pressure prevailing in said compartment 4 at control pressure is exerted on the wall 16 'acting as a piston, said movable wall 16' being of section smaller than the section of the wall 16, this which has the advantage of making it possible to use a control pressure greater than the operating pressure, which makes it possible to perform a pre-expansion in the first expansion stage 30 of lower amplitude than in the previous embodiments and allows, in addition, an escape of gases through the emergency stop valves or low pressure adjustment more

  efficient, due to the greater pressure difference.

  FIG. 7 is analogous to FIG. 6, except that the first expansion stage 30 has been omitted, so that the gas leaving the bottle 31 is conveyed at its high pressure or storage pressure directly into pressure compartment 2

entry.

  Such an embodiment applies particularly well to gas conditioned in the liquid phase,

  such as carbon dioxide, nitrous oxide, G.P.L.

  or any other gas stored at a substantially constant and low high pressure, that is to say of the order of 15.105

Pa to 30.105 Pa, for example.

Fa to 30.10 Fa, for example.

  The regulator assembly according to the invention has, whatever its embodiment, a certain number of advantages compared to the regulator of the prior art, namely a suppression of the screw and the spring usually used to regulate the relaxation, simpler adjustment by means of a valve actuated by pneumatic adjustment buttons, improved ergonomics and a reduction in size, in particular by incorporating the first expansion stage, when there is one, inside the bottle and by decreasing the

  second stage section of relaxation.

  In addition, in order to avoid any handling error, the pressure adjustment valves inside the control pressure compartment can be provided with means allowing the user to know immediately and without possible error if his action is going to cause an increase or decrease in the pressure inside said pressure-controlled compartment, for example, said control valves may be marked with a "+" sign in relation to the valve intended to increase the pressure inside control pressure compartment and a "-" sign for the valve to reduce the

pressure in said compartment.

  Furthermore, it is also possible to incorporate into the regulator according to the invention, flow control means, such as a flow meter, intended to control the flow

  gases delivered at low pressure outlet.

Claims (16)

Claims   1. Pressure regulator assembly for pressurized fluid, in particular for pressurized fluid container, comprising at least one main chamber (1) for gas expansion comprising at least one inlet pressure compartment (2), a compartment (3) for outlet pressure and a control pressure compartment (4), said inlet pressure compartment (2) and said outlet pressure compartment (3) communicating by expansion means (9, 10, 25), and said compartment (3) with outlet pressure and said compartment (4) with control pressure   being separated by at least one movable wall (16, 16 ').   2. A regulator assembly according to claim 1, characterized in that said expansion means (9, 10, 25) comprise a relaxation opening (9) and closure means (10, 25) and in that said at least a movable wall (16, 16 ') cooperates with said closure means (10, 25), so as to at least partially close said expansion orifice (9) as a function of a predetermined and adjustable control pressure   prevailing in the control pressure compartment (4).   3. Regulator assembly according to one of claims   1 or 2, characterized in that it further comprises pressure regulation means (14, 15, 20, 21) making it possible to adjust the control pressure prevailing in   the control pressure compartment (4).   4. Regulator assembly according to one of the claims   1 to 3, characterized in that said control pressure compartment (4) comprises at least one gas inlet orifice (14) and at least one gas outlet orifice (15), the orifice (14) d gas inlet communicating with a pressure control circuit (22) controlled by a gas inlet valve (20).   5. A regulator assembly according to claim 4, characterized in that the orifice (15) of gas outlet is   controlled by a gas outlet valve (21).   6. Regulator assembly according to one of the claims   1 to 5, characterized in that the gas inlet and outlet valves (20, 21) are valves controlled by manual pressure.   7. Regulator assembly according to one of claims   1 to 6, characterized in that a flow limiter (41) is arranged between the inlet valve (20) and the inlet orifice (14).   8. Regulator assembly according to one of claims   1 to 3, characterized in that the inlet pressure compartment (2) has at least one gas supply orifice (11) connected to a supply circuit (12) in gas.   9. Regulator assembly according to one of claims   4 to 8, characterized in that the pressure control circuit (22) is connected to the gas supply circuit (12).   10. Regulator assembly according to one of claims   1 to 3, characterized in that the closure means (10, 25, 26) comprise a valve (10) subjected to a force of   tension by a spring means (25).   11. Regulator assembly according to one of claims   1 to 10, characterized in that it further comprises   pre-expansion means (30) for pressurized fluid.   12. Pressure regulator assembly according to one of claims   1 to 11, characterized in that it further comprises a safety circuit (26 ') comprising a stop means   emergency (38), preferably an emergency stop valve.   13. Regulator assembly according to one of claims   1 to 12, characterized in that the main chamber (1) further comprises a compartment (5) at atmospheric pressure, said compartment (5) at atmospheric pressure being located between the compartment (3) at outlet pressure and the pressure compartment (4) control.   14. Container for pressurized fluid, in particular a gas cylinder (2) under pressure, characterized in that it is equipped with a pressure reducer assembly according to one of claims 1 to 13.   15. Container according to claim 14, characterized in that the pre-expansion means (30) of the regulator assembly are located inside the container, when   the regulator assembly is mounted on said container.   16. Use of a container according to one of   claims 14 or 15 in a welding operation, cutting or technical processing.