Device for generation of a gas

Abstract

A device includes a catalytic system and an electromagnetic system. The catalytic system defines a catalysis chamber and includes a catalyst of a reaction to generate a gas from a liquid. The catalyst is housed in the catalysis chamber. The electromagnetic system includes a coil and a rod mobile relative to the coil, the rod being fixed to the catalytic system and including a magnet and a core. The electromagnetic system is configured to move the rod relative to the coil when an electrical current is passed through the coil, so as to dispose the catalytic system in an open position in which the catalysis chamber is in fluidic communication with the outside. The catalytic system is disposed in a closed position in which the catalysis chamber is hermetically closed in the absence of an electrical current through the coil.

Claims

1. A device including a catalytic system and an electromagnetic system, the catalytic system defining a catalysis chamber and including a catalyst of a reaction to generate a gas from a liquid, the catalyst being housed in the catalysis chamber, the electromagnetic system including a coil and a rod mobile relative to the coil, the rod being fixed to the catalytic system and including a magnet and a core, the electromagnetic system being configured to move the rod relative to the coil when an electrical current is passed through the coil, so as to dispose the catalytic system in an open position in which the catalysis chamber is in fluidic communication with the outside, and the catalytic system being disposed in a closed position in which the catalysis chamber is hermetically closed in the absence of electrical current through the coil.

2. The device according to claim 1, at least a part of the catalytic system being subjected to an electromagnetic closing force induced by the magnet that holds the catalytic system in the closed position in the absence of electrical current through the coil.

3. The device according to claim 1, the catalytic system including a first part and a second part fixed rigidly to the rod, the first and second parts together defining the catalysis chamber and being mobile relative to one another between the open and closed positions.

4. The device according to claim 3, at least a part of the catalytic system being subjected to an electromagnetic closing force induced by the magnet that holds the catalytic system in the closed position in the absence of electrical current through the coil, said part of the catalytic system including at least the first part and/or the catalyst.

5. The device according to claim 3, the second part being compressed between the first part and the rod in the closed position.

6. The device according to claim 3, including a casing, the first part being rigidly fixed to the casing, the first part and the casing forming a cage in which the coil is trapped.

7. The device according to claim 1, the magnet being fixed to one longitudinal end of the core.

8. The device according to claim 7, the rod including another magnet fixed to the longitudinal end of the core opposite the longitudinal end to which the magnet is fixed, the poles of the same polarity of the magnet and of the other magnet being disposed facing one another.

9. The device according to claim 1, including a spring for applying an elastic force to the catalytic system.

10. The device according to claim 1, the spring being compressed by the catalytic system in the open position.

11. The device according to claim 9, the spring applying an elastic closing force to the catalytic system to hold the catalytic system in the closed position in the absence of the passage of the electrical current in the coil.

12. The device according to claim 11, the spring being housed between the coil and the catalytic system.

13. The device according to claim 1, including a buoy conformed so that when the device is brought into contact with a liquid having a specific gravity greater than 0.6 the buoy floats on the liquid and the catalytic system is at least partly immersed in the liquid.

14. A gas generator, the generator including: an enclosure defining an interior space containing a liquid, and the device according to claim 1 at least partly immersed in the liquid so that in the open position the liquid penetrates into the catalysis chamber and the gas is generated by bringing the liquid into contact with the catalyst.

15. The gas generator according to claim 14, the liquid being chosen from a solution of hydride and a liquid organic hydrogen carrier.

16. The gas generator according to claim 14, the device being freely mobile in the enclosure.

17. A method of generating dihydrogen including the following successive steps: a) procuring the generator according to claim 15; and b) supplying electrical power to the coil to open the catalysis chamber by moving the rod relative to the coil so that the liquid penetrates into the catalysis chamber and comes into contact with the catalyst.

18. The method according to claim 17, comprising closing the catalytic system by cutting off the supply of electrical power to the coil.

19. The device according to claim 1, the spring being compressed by the catalytic system in the closed position.

20. The device according to claim 1, including a buoy conformed so that when the device is brought into contact with a liquid having a specific gravity greater than 0.6 the buoy floats on the liquid and the catalytic system is entirely immersed in the liquid.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Other features, variants and advantages of the invention will emerge more clearly on reading the detailed description and the examples provided hereinafter by way of nonlimiting illustration and examining the appended drawings, in which:

(2) FIG. 1 shows in longitudinal section one example of a gas generator according to the invention;

(3) FIG. 2 is an enlarged view of the device contained in the gas generator shown in FIG. 1, in the closed position of the catalytic system;

(4) FIG. 3 is an exploded 3D view of the device from FIG. 2;

(5) FIG. 4 shows the device from FIG. 2 in an open position of the catalytic system,

(6) FIG. 5 shows a 3D view of the device from FIG. 2 in an open position of the catalytic system;

(7) FIG. 6 shows the device from FIG. 5 in a closed position of the catalytic system;

(8) FIG. 7 shows another example of the device seen in longitudinal section and in an open position of the catalytic system;

(9) FIG. 8 shows the device from FIG. 7 in a closed position of the catalytic system;

(10) FIG. 9 shows a further example of the device seen in longitudinal section and in an open position of the catalytic system;

(11) FIG. 10 shows the device from FIG. 9 in a closed position of the catalytic system;

(12) FIG. 11 shows another embodiment of a gas generator;

(13) FIG. 12 shows the gas generator from FIG. 11 containing a smaller volume of liquid; and

(14) FIG. 13 shows the gas generator from FIG. 11 oriented differently relative to the direction of gravity.

(15) In the figures, the scales and proportions of the various members and units constituting the apparatus and the device are not necessarily respected. Moreover, for clarity, members may be represented as not being in contact with one another although they are so in practice. Different references may designate the same member.

DETAILED DESCRIPTION

(16) One example of a gas generator 5 according to the invention is shown in FIG. 1. The gas generator 1 includes an enclosure 10, a device 15, a battery 20, a measurement module 25 and a control module 30.

(17) The enclosure defines an interior space 35 containing a liquid 40 adapted to react in contact with a catalyst to generate the gas. The liquid is for example a hydride aqueous solution or a liquid organic hydrogen carrier, which is able to generate dihydrogen by reacting with a catalyst.

(18) The enclosure includes a vent 45 for evacuating the gas generated in the interior space, for example to a fuel cell, not shown.

(19) The battery 20 is disposed outside the enclosure. Other arrangements of the battery may be envisaged, as will become apparent hereinafter. The battery is electrically connected to the device by means of conductive and flexible cables 50a-b immersed in the liquid.

(20) The measurement module 25 is configured to measure a magnitude to be controlled. It is connected, for example electrically, to the control module to which is transmits the measured value of the magnitude to be controlled. For example the measurement module contains a sensor measuring the pressure of the gas in the enclosure.

(21) The control module analyzes the value of the magnitude to be controlled and as a function of the result of the measurement is able to generate and to transmit a control signal S.sub.c to the battery to trigger or to cut off the electrical power supply of the device.

(22) The device is immersed in the liquid.

(23) In the example from FIG. 1, the device is fixed to the wall of the enclosure and is disposed substantially at the center of the enclosure. However, such an arrangement, simple to produce, is not limiting on the invention. As will be described hereinafter, other advantageous arrangement variants may be envisaged.

(24) The device has a circular cylindrical and tubular general shape about a longitudinal axis X. It includes a catalytic system 60, an electromagnetic system 65 and a casing 70.

(25) The casing has a hollow and tubular general shape. It includes a bottom wall 75 with a central hole 80 through it from which extends a lateral wall 85 in which windows 90 are produced.

(26) The catalytic system includes a first part 100, a second part 95, a seal 105 and a catalyst 110.

(27) In the configuration shown in FIGS. 1, 2 and 6 the catalytic system is disposed in a closed position. The first part blocks the upper opening 115 defined by the second part. The first part and the second part therefore define a closed catalysis chamber 120.

(28) The catalyst 110, based for example on platinum and/or ruthenium, is housed in the catalysis chamber. It is of angular shape and is fixed to the first part. The first part has a wall 125 disposed facing the catalysis chamber, from which a projecting portion 130 extends in the longitudinal direction. The projecting portion has a lateral contour 135 of complementary shape to the shape of the catalyst. The catalyst is therefore fitted over and fixed to the first part, as shown in FIG. 1.

(29) According to a variant that is not shown, the catalyst may be carried by the second part, for example rigidly fixed to the bottom of the second part. According to a further variant, the catalyst may take the form of two, for example annular, blocks respectively carried by the first part and by the second part.

(30) The second part has a bottom 140 and a lateral wall 145 extending longitudinally from the bottom. The seal 105, made for example of an elastic material, is mounted on a longitudinal end face of the lateral wall of the second part.

(31) In the closed position, the first and second parts sandwich and compress the seal. They therefore provide the seal against liquid and gas of the catalysis chamber. Accordingly, in the closed position of the catalytic system the liquid contained in the enclosure is not able to penetrate into the catalysis chamber. No gas is then generated.

(32) Moreover, the first part 100 is mounted on, for example screwed to, the casing 70. The casing and the first part together define a cage 148 in which the electromagnetic system is housed.

(33) The first and second parts are mobile in translation relative to one another in the longitudinal direction, as indicated by the arrows T. The movement of the second part relative to the first part is guided by the electromagnetic system to which the second part is connected.

(34) The electromagnetic system 65 includes a coil 150 extending around the longitudinal axis and a rod 155.

(35) The coil includes a winding support around which a copper wire is wound.

(36) The coil includes an opening 160 through which the rod is mobile in translation along the longitudinal axis as shown by the arrows T.

(37) In the example shown, the coil has a toric shape and completely surrounds the rod. A toric shape is not limiting on the invention, however. Alternatively, the coil may have a more generally annular shape.

(38) The coil is housed in the cage between the lateral walls and the bottom of the casing and the catalytic system. The coil is fixed to the casing, for example clipped against the lateral wall or glued to the bottom wall. It is therefore fixed to the first part.

(39) Moreover, the rod includes a core 170 and a magnet 175 fixed to one longitudinal end of the core. In the example from FIG. 1 the core is a circular cylinder but other shapes may be envisaged.

(40) The core is preferably made of a ferromagnetic material and the magnet is fixed to the core. In a variant, the core may be made of an amagnetic or paramagnetic material.

(41) In the closed configuration the magnet is disposed at its distance from the coil in the longitudinal direction. It is in particular fixed outside the central opening.

(42) The rod 155 is fixed rigidly onto the second part 95.

(43) In the example shown the second part is made of a plastic material.

(44) The first part is made of a ferromagnetic material. It is therefore subjected to an electromagnetic force induced by the magnet that tends to attract it against the magnet.

(45) In the absence of an electrical current flowing in the coil, the attraction between the first part and the magnet maintains the catalytic system in the closed position.

(46) When an electrical current coming from the battery 20 passes through it, the coil 150 generates an electromagnetic field that attracts the magnet toward the coil. The intensity of the magnetic field is such that the absolute value of the force of attraction generated by the coil on the magnet is greater than the electromagnetic attraction force between the magnet and the catalytic system. The magnet is then moved in translation relative to the coil in the longitudinal direction toward the coil, as indicated by the arrows T, and draws with it the second part in a rigid body movement.

(47) The coil being fixed relative to the first part, the result of this is that the second part is then distant from the first part. The catalytic system is then disposed in the open position, as can be seen in FIGS. 4 and 5. The liquid 40 contained in the enclosure then passes through the windows 90 of the casing and penetrates into the catalysis chamber via the opening 178 defined by the movement of the second part relative to the first part and is able to come into contact with the catalyst. Gas is then generated.

(48) The pressure of gas in the enclosure then increases as the catalytic reaction proceeds and is measured by the measurement module. If the pressure of gas in the enclosure reaches a maximum pressure, the control module generates and transmits a control signal to cut off the supply of electrical current to the coil. The coil then no longer generates an electromagnetic field.

(49) The magnetic force induced by the magnet, to which the first part is subjected, is then such that the first part is attracted by the magnet and is moved in the longitudinal direction until the catalytic system is disposed in the closed position.

(50) The device shown in FIG. 1 is therefore particularly compact, and occupies a restricted volume in the interior space. The enclosure may advantageously contain a large volume of liquid.

(51) The device 15 shown in FIGS. 7 and 8 differs from the device shown in FIGS. 1 to 6 in that the rod 155 includes another magnet 180.

(52) The other magnet is mounted on the longitudinal end 185 of the core opposite that 190 to which the magnet is fixed.

(53) The poles of the same polarity of the two magnets are disposed one facing the other in the longitudinal direction.

(54) When the coil is supplied with electrical current both magnets are subjected to an electromagnetic force that drives them toward the open position of the catalytic system. It is therefore possible to reduce the size of the coil by reducing the number of windings of metal wire, for example by at least a factor of 2 relative to the device from FIGS. 1 to 6, whilst producing a force to retain the catalytic system in the closed position that is substantially identical. The compactness of the device is therefore improved, as is the energy efficiency of the device. Such a device is particularly preferred.

(55) The device 15 from FIGS. 9 and 10 differs from the device shown in FIGS. 1 to 6 in particular in that the device includes a spring 200, in that the core 170 is in contact via its longitudinal end 190 with and fixed to the second part 95, and in that the magnet 175 is fixed to the opposite end 185.

(56) The spring 200 is sandwiched between the coil 150 and the second part 95, against which it bears.

(57) In the example shown the spring is a Belleville washer including a central opening 205 in which the rod is engaged and is mobile. Alternatively, the spring may be a coil spring.

(58) In the open and closed positions of the device the spring is compressed. The elastic energy stored in the spring is higher in the open position than in the closed position.

(59) In the example shown, the first and second parts and the catalyst are made of amagnetic material, for example of a plastic material. No force of attraction is generated by the magnet in the catalytic system in the closed position or in the open position.

(60) When the battery delivers an electrical current to the coil, the magnet is attracted toward the coil by the electrical current as it generates. The coil is configured so that the electromagnetic force generated by the passage of the current in the coil has an absolute value greater than the elastic compression force in the spring in the closed position.

(61) The second part is then moved toward the coil, thus opening the catalysis chamber. The movement of the second part is stopped when the force of attraction of the magnet compensates the elastic compression force of the spring.

(62) When the supply of electrical current to the coil is cut off, the spring expands and brings about the movement of the second part against the first part to close the catalytic system. The catalytic system is then subjected to an elastic closing force generated by the spring in compression.

(63) Such a device is advantageous. For example, it may be intended to come into contact with liquids that corrode ferromagnetic metals such as steel. For example, the constituent members of the device, apart from the coil, the magnet and the catalyst, may be made of a polymer, for example a thermoplastic.

(64) Moreover, the device may include another magnet, as shown in FIGS. 7 and 8.

(65) In another variant of the device shown in FIGS. 9 and 10 the first part is made of a ferromagnetic material. The magnet and the first part are then attracted toward one another by the effect of the magnetic force induced by the magnet.

(66) According to a first example, in the closed position the spring may be in equilibrium, that is to say it does not store elastic energy. It does not apply an additional force to the catalytic system to keep the catalysis chamber in the closed position. According to a second example, the spring may be compressed and applies an additional force to the catalytic system.

(67) FIGS. 11 to 13 show a gas generator 5 including a device as represented in FIG. 2. The device further comprises a buoy 210 mounted on the casing.

(68) The device is electrically connected to a battery 20 by means of flexible electrical cables 50a-b.

(69) The device is freely mobile in the interior space. The electrical cables do not impede the movement of the device relative to the enclosure.

(70) The buoy floats on the liquid and it maintains the catalytic system 60 completely immersed in the liquid, whether the volume of liquid contained in the second part is high, as shown in FIG. 11, or low, as shown in FIG. 12. Similarly, as shown in FIG. 13, when the enclosure is disposed with a different orientation, for example at 90° relative to the direction G of gravity, the catalytic system is kept totally immersed in the liquid. The flow rate of gas generated is the optimum whatever the configuration shown in FIGS. 11 and 13.

(71) Moreover, in the example shown, the electromagnetic system 65 is totally immersed in the liquid. In a variant that is not shown, it may be disposed outside the liquid.

Examples

(72) Dimensions of the Coil

(73) By way of illustration, to ensure operation of the device consuming little electricity, it is required that the energy consumption of the electromagnetic system be at maximum 20 W. It is moreover required in accordance with the example that the coil generate on the magnet a force greater than the force applied by the magnet to the first part in the closed position that is greater than 2 N.

(74) The coil includes n windings of a copper wire.

(75) The total length of the copper wire is L=n.Math.l.sub.t with l.sub.t the length of a winding. The section Sb of the winding is obtained from the section of the copper wire, the whipping rate f and the winding number Sb=S.Math.n/f.

(76) The resistance R of the coil is expressed as R=n.sup.2.Math.l.sub.t.Math.ρ/(Sb.Math.f), ρ being the electrical resistivity of copper equal to 1.7×10.sup.−8 Ω.Math.cm.

(77) The power P is then expressed as P−RI.sup.2−(n.Math.I).sup.2.Math.lt.Math.ρ/(Sb.Math.f).

(78) The person skilled in the art knows that the intensity of the magnetic field produced by the coil is dependent on the product n.Math.I of the number n of windings by the current I circulating in the coil.

Example 1

(79) In a first example as shown in FIGS. 7 and 8, the device has a tubular general shape, a height equal to 50 mm and a diameter equal to 30 mm.

(80) The magnet applies a closing force to the catalytic system of the order of 2.5 N. It consists of NdFeB and has a flat circular cylindrical pastille shape of 10 mm diameter and 2 mm height.

(81) The first part is made of steel or of soft iron.

(82) In the closed position, the projecting portion is 2 mm from the magnet, the distance being measured in the longitudinal direction.

(83) The coil is made of iron or of soft steel and has a length equal to 13 mm and a diameter equal to 10 mm.

(84) The coil includes a magnetic circuit formed of steel plate 1 mm thick. The magnetic circuit channels the magnetic flux produced by the coil.

(85) The coil has a toric shape of inside and outside diameter equal to 12 mm and 30 mm respectively, which corresponds to a winding area of 90 mm.sup.2 and a winding length of 65 mm. The rod of diameter equal to 10 mm is therefore at a distance from the coil when it is engaged in the coil.

(86) Opening the catalytic system necessitates the coil to have a product n.Math.I of the order of 500 A.turns. The person skilled in the art knows how to determine this product easily as a function of the electrical voltage U at the terminals of the coil that is expressed as U=lt.Math.ρ/(Sb.Math.f).Math.n.sup.2.Math.I. They also know how to determine the diameter D of the wire from the relation D=(4.Math.Sb.Math.f/π.Math.n).sup.0.5.

(87) For example, at a voltage U equal to 5 V, the number n of turns is equal to 400, the current I flowing through the coil is 1.3 A, the diameter D of the wire of the coil is equal to 0.38 mm and the power P dissipated to open the catalysis chamber is 6 W.

(88) The travel of the core is 4 mm. The movement between the extreme open position and the closed position takes approximately 10 ms.

Example 2

(89) In a second example as shown in FIGS. 7 and 8, the device has a tubular general shape, a height equal to 50 mm and a diameter equal to 30 mm.

(90) The magnet applies a closing force to the catalytic system of the order of 2.5 N. It consists of ferrite and has a circular cylindrical pastille shape of 20 mm diameter and 5 mm height. The core is made of iron or of soft steel and has a length equal to 7 mm and a diameter equal to 20 mm.

(91) In the closed position, the projecting portion of the second part is 2 mm from the magnet, the distance being measured in the longitudinal direction.

(92) The coil includes a magnetic circuit formed of steel plate 1 mm thick.

(93) The coil has a toric shape of inside and outside diameter equal to 22 mm and 32 mm respectively and the height of the torus is 10 mm, which corresponds to a winding area of 50 mm.sup.2 and a winding length of 85 mm.

(94) Opening the catalyst system necessitates the coil to have a product n.Math.I of the order of 200 A.turns.

(95) For example, at a voltage U equal to 5 V, the number n of turns is equal to 430, the current I is 0.5 A, the diameter D of the wire of the coil is equal to 0.27 mm and the power P dissipated to open the catalysis chamber is 2.5 W.

(96) The travel of the core is greater than 5 mm. The movement between the extreme open position and the closed position takes approximately 20 ms.

(97) As has been clearly apparent throughout the present description, generation of gas, in particular of dihydrogen, by means of a generator including the device according to the invention can easily be adapted as a function of the application for which the generated gas is intended. Moreover, the device is particularly compact and its use consumes little energy.

(98) Of course, the invention is not limited to the embodiments of the device and of the gas generator according to the invention and to the embodiments of the method described and shown.