FR2654176A1 - GAS DETENDER WITH SAFETY AGAINST MEMBRANE BREAKING. - Google Patents

Abstract

Gas regulator. It comprises a body (1) subdivided by a membrane (2) into a first chamber (3) having an outlet duct (8) and an inlet duct (5), and a second chamber (4) provided with a vent (11). Suddenly actuated means are provided for increasing the pressure drop in the vent (11) when the pressure in the second chamber (4) exceeds a second given threshold.

Description

The present invention relates to regulators

  of gas used for the supply of expanded gases to industrial

  tries or individuals. There is already known a gas expander comprising a body made of a gas impermeable material, which is subdivided by a pressure diaphragm into a first chamber and into a second chamber. The first chamber is provided with a gas outlet duct and a gas chamber. inlet duct having a valve The second chamber is provided with a vent opening to the outside A regulating spring is mounted so as to push the membrane towards the first chamber, against the opposing pressure forces which prevail

  in this first chamber The arrangement is such that the de-

  placement of the membrane, when the difference between

  prevailing in the first chamber and that in the second chamber becomes less than a first threshold

  given, leads to the closing of the input duct by the

  pet If there is a break in the pipeline downstream,

  the pressure in the first chamber drops as soon as the first

  the threshold is crossed, the flapper is applied to its seat and

  closes the inlet duct When the membrane is exhausted

  the gas, especially when the tear is im-

  load, enters the second chamber and accumulates because the flow that leaves through the vent is limited.

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  pressures in both the first and second chambers

  room, increase to the maximum pressure of admission.

  There is no longer any relaxation of the gas The downstream user devices therefore receive gas under too high pressure which deteriorates them.

  The invention overcomes this disadvantage by a

  which, when a membrane puncture occurs, induces

  overthrow the gas flow supplied by the regulator.

  According to the invention, means are provided for

  sudden increase in pressure drop in the vent, when the pressure in the second chamber exceeds a

second threshold given.

  At a single stroke, as soon as the pressure in the second chamber exceeds the second given threshold, the gas pressures in the first and second chambers become equal. Due to the force of the regulating spring applied to the diaphragm, the diaphragm moves to the first chamber This displacement causes the closure of the valve

gas does not flow anymore.

  According to one variant, the means with sudden actuation for increasing the pressure drop in the vent comprise means for closing the vent.

  another variant, these means with a sudden increase in

  the pressure drop of the vent only include means of reducing the cross section of the

  the vent, for example at least one-fifth of its initial value

  and, preferably, to one-tenth of this, so that once the regulator no longer delivers, the gas accumulated in the chambers and in the downstream pipe can

  to escape gradually to the atmosphere.

  The suddenly actuated means for increasing the pressure drop in the vent comprise, advantageously, a moving part displaced by the action of the forces due to the pressure prevailing in the second chamber when the second threshold is exceeded and intended to cooperate with a part

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  In a variant, the movable part and the fixed part bear, respectively, magnets which attract when the displacement has brought them sufficiently close together. According to another variant, the movable part is a click element such as a click blade having two stable positions, one in which the vent is open and the other in which it is closed or at least closed for nine-tenths It is advantageous to arrange the magnets so that they are out gas contact, to prevent all

  consequences due to an electrostatic effect.

  It is advantageous to mount a return spring so that it opposes the action of the means of increasing

  the pressure drop in the vent, as long as the pressure

  in the second chamber remains lower than the second given threshold Even if the regulator is overturned, the moving part can not come under the effect of the force of gravity,

  enough close to the fixed part to provoke

  clen-chement means for increasing the pressure drop, because the spring keeps the moving part away from the fixed part It is only when the much greater pressure forces far outweigh the force applied by the return spring to the moving part that

  it is close enough to the fixed and

void the trigger.

  To prevent the effects of a shock on the

  A damper, in particular a fluid damper, is mounted so as to temporarily oppose the action of the means for increasing the pressure drop in the vent. The compression of the air of the shock absorber delays the displacement of the moving part towards the fixed part and, as the forces

  which would tend to provoke this displacement are

  because the shock is due to a single shock or vibration, the moving part remains remote from the stationary part, the return spring also contributing to recalling the moving part. Preferably, the damper defines a narrow range of

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  passage of the air, this interval has a variable section, which increases as one tends to the position where the means for increasing the pressure drop come into action. Gas regulators of this kind include, in

  generally, a rearming mechanism designed to

  fart from its seat after it has been applied, because the pressure in the first chamber has become less than

  given threshold, or because an overpressure has occurred

  in this room. Advantageously, the means available to

  sudden increase in the pressure drop in

  the vent are mounted in such a way as to block the mechanism

  arming when said suddenly actuated means has acted.

  It is no longer possible to reset the regulator if the

membrane is punctured.

  It is also possible to mount this reset mechanism so as to prevent said sudden-action means of increasing the pressure drop in the event of being able to act as long as the mechanism is in the reset position. When the flow rate is re-established in the regulator, the valve deviates from

  its seat and thereby cause the displacement of the

  brane towards the second chamber, with compression of the regulation spring which is there, and especially increase of the pressure which reigns there, which can provoke the triggering

  because of this transient phenomenon, means to

  sudden increase in the pressure drop in

  the vent The reset mechanism is opposed.

  In the attached drawing, given only for

For example:

  Figure 1 is a sectional diagram of a pressure regulator according to the invention; Figures 2 and 3 are sectional views of the

  part of the vent of this regulator, while the means to

  sudden increase in the pressure drop in

  the vent are in the rest position in Figure 2, and in posi-

  triggered in Figure 3; Figure 4 is a sectional view of an alternative embodiment of the vent; Figure 5 illustrates another variant; FIG. 6 schematically represents a mode of

  implementation, illustrating the cooperation of the

  and means for sudden actuation of increasing the pressure drop in the vent, and

  Figure 7 illustrates another variant.

  The gas expander shown in FIG.

  takes a watertight body 1, subdivided by a membrane 2 into a first chamber 3 and a second chamber 4 The first

  The chamber is provided with an inlet duct 5 with a valve 6 capable of

  A control spring 9, housed in the second chamber 4, tends to push the diaphragm 2 towards the first chamber 3. A lever mechanism 10 connects the membrane 2 to the valve 6, so that the displacement of the membrane 2 to the first chamber 3 tends to bring the valve 6 of its

  seat 7 When the difference between the pressure in the

  first chamber 3 and that in the second chamber 4 becomes lower than a first given threshold, the valve 6 closes the

leads 5.

  A vent 11 puts the second chamber 4 in communica-

  with the exterior A rearming mechanism 12 class-

  It allows, by a cam 13 pushing a pin 14, to spread, via the control mechanism 10,

  The valve 6 of its seat 7 In FIG.

  part of suddenly actuating means of increase

  the pressure drop in the vent, which will be described later.

  secondly, serves as a stop for a ramp of the rearming mechanism

  12, preventing it from moving to the rearming position

if the rod 15 is out.

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  The vent shown in FIGS. 2 and 3 consists of a connector 17 coming from the body 1 and on which is screwed a threaded tube 18 having a shoulder 19 On the free front annular face of the connector 17 is placed a cup 20 provided with several holes 21 and an orifice 22 On the bottom face of the cup 20, which is farthest from the connector 17, is fixed an annular magnet 23 This same face is in contact with a return spring 24 whose other end relies on the inner face of the shoulder 19 The tube 18 has a projecting portion 25 facing the magnet 23 and

  carrying, in front of it, an annular magnet 26

  between the magnet 23 and the magnet 26 is such, in the figure

  2, that they do not attract The stem 15 comes from the

  shovel 20 and passes in the tube 18, to lead to

outside.

  In Figure 3, a puncture C membrane occurred The pressure in the chamber 4 has exceeded a given second threshold Under the effect of the gas pressure, the movable cup 20 has moved relative to the fixed tube 18 When

  the distance between the magnets 23 and 26 has become sufficiently

  The holes 21 are no longer open towards the outside via the tube 18 The pressure in both

  chambers 3, 4 become substantially equal.

  From this moment, the membrane 2 (FIG. 1) is lowered by the effect of the spring 9. The control mechanism 10 brings about

  the valve 6 on the seat 7 The regulator ceases to debit.

  In Figure 4, the tube 18 is extended by a bend 27 and the two magnets 23, 26 are housed in an extension 28, outside the tube 27 defining the path of the gas to

  The magnet 23 is connected by a rod 29 to the neck.

  shovel 20 Air is trapped in the space 30 between the two magnets 23 and 26, but can escape through

  the narrow gap 31 between the magnet 23 and the inner face

  of the extension 28 The narrow interval 31 has a sec-

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  variable, which increases as the

  shovel 20 moves towards the protruding part 25

  deur is overturned, the cup 20 is prevented from approaching

  the protruding portion 25, by the spring 24, despite the force of the gravity It is only when the pressure in the second chamber 4 far outweighs the force

  of the spring 24 that the triggering can take place.

  If there is a shock or vibration causing the cup 20 tends to be thrown abruptly toward the projecting portion 25, the chamber 30 which constitutes a fluid damper temporarily opposes this movement as long as the air does not. The means with sudden actuation of increase of the pressure drop, formed in particular by the two magnets 23 and 26 do not therefore trigger under the slightest shock. But when the pressure in the second chamber 4 applies to the cup 20 permanent forces, the air contained in the chamber 30 comes out

  by the gap 23 and the magnets 23, 26 can get closer

  expensive one of the other, all the faster than the section of

the narrow interval 31 increases.

  In Figure 5, the magnets have been replaced by a snap-action blade 32 which can assume a rest position, shown in solid lines and a release position shown in phantom, the blade having holes 33

allowing the passage of gas.

  FIG. 6 schematically shows, in the same way as in FIG. 1, a variant of the regulator according to the invention. In this case, the ramp 16 prevents the rod

  to exit when the reset mechanism 12 is in position.

  resetting, that is to say when the valve 6 is spaced from the seat 7, during the restoration of the regulator flow The means for sudden actuation of increase of the pressure drop in the vent are thus blocked even if , under the effect of a transient phenomenon, the pressure in the second

bedroom 4 becomes too big.

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  Figure 7 illustrates a particular embodiment of

  easy to manufacture Two blades 35, 36 are

  tilting tees in cavities of the tube 18 and articulated on a pin 37 integral in displacement of the cup 20 A tension spring 34 is hooked by its two ends to the blades 35, 36 The position in phantom of the

  blades 35, 36 corresponding to the trigger position.

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Claims (11)

  1 gas regulator comprising a body (1) subdivided   provided by a membrane (2) in a first chamber (3) which is provided with an outlet duct (8) and an inlet duct (5) having a valve (6) and a second chamber (4) ) which is provided with a vent (11) and in which a regulating spring (9) is mounted so as to push the diaphragm (2) towards the   first chamber (3), against the pressure forces   tagonists who reign there, the arrangement being such that the de-   placement of the membrane (2), when the difference between   pressure prevailing in the first chamber (3) and the pressure   in the second (4) becomes smaller than a first given threshold, causes the closing of the inlet duct (5) by the valve (6), characterized by means for sudden actuation of increase of the pressure drop (23). , 26) in the vent (11), when the pressure in the second chamber (4) exceeds a given second threshold.   Gas regulator according to claim 1,   characterized in that the suddenly actuated means for increasing the pressure drop in the vent comprise   means for closing the vent.   Gas regulator according to claim 1,   characterized in that the sudden-action means for increasing the pressure drop in the vent comprise means for decreasing the cross section of the vent. 2654176   4 Gas regulator according to one of the claims   1 to 3, characterized in that the sudden-action means for increasing the pressure drop in the vent comprise a movable part (20) displaced under the action of the forces due to the pressure prevailing in the second chamber ( 4) when the second threshold is exceeded and intended to cooperate with a fixed part.   Gas pressure regulator according to Claim 4, characterized in that the movable part (20) and the stationary part (18) bear, respectively, magnets (23, 26) which attract each other.   Gas regulator according to claim 4,   characterized in that the moving part is a snap element (32).   Gas regulator according to claim 6,   characterized in that the click element consists of two blades (35, 36) to which are attached respectively the ends of a spring (34).   8 Gas regulator according to claim 5,   characterized in that the magnets (23, 26) are arranged   to be out of contact with the gas.   9 Gas regulator according to one of the claims   1 or 3 to 8, characterized in that the action means   sudden increase in the pressure drop in the vent are such that they reduce the cross-section of the   the vent at least one fifth of its initial value.   Gas regulator according to one of the claims   characterized by a spring (24) mounted to oppose the action of the sudden-action means for increasing the pressure drop in the vent as long as the pressure in the second chamber (4) ) is less than the second given threshold.   11 Gas regulator according to one of the claims   tions, characterized by a damper (30) mounted thereon 2654176 so as to temporarily oppose the action of the means   sudden actuation of increase of the pressure drop.   12 Gas regulator according to one of the claims   previous arrangements, comprising a reset mechanism (12) for moving the valve (6) away from its seat (7), characterized in that the snap-action means (15) are mounted to block the reset mechanism (12). when said means have acted.   13 Gas regulator according to one of the claims   preceding arrangements, comprising a resetting mechanism (12) for moving the valve (6) away from its seat (7), characterized   in that the reset mechanism (12) is mounted manually.   to prevent the said means of action, as long as the mechanism is in the reset position.