EP0518788B1 - Pressure regulated steam generator - Google Patents

Pressure regulated steam generator Download PDF

Info

Publication number
EP0518788B1
EP0518788B1 EP92420190A EP92420190A EP0518788B1 EP 0518788 B1 EP0518788 B1 EP 0518788B1 EP 92420190 A EP92420190 A EP 92420190A EP 92420190 A EP92420190 A EP 92420190A EP 0518788 B1 EP0518788 B1 EP 0518788B1
Authority
EP
European Patent Office
Prior art keywords
water
opening
pressure
level
vessel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP92420190A
Other languages
German (de)
French (fr)
Other versions
EP0518788A1 (en
Inventor
Raymond Violi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Societe Cooperative de Production Bourgeois SCOP
Original Assignee
Societe Cooperative de Production Bourgeois SCOP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Societe Cooperative de Production Bourgeois SCOP filed Critical Societe Cooperative de Production Bourgeois SCOP
Publication of EP0518788A1 publication Critical patent/EP0518788A1/en
Application granted granted Critical
Publication of EP0518788B1 publication Critical patent/EP0518788B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/78—Adaptations or mounting of level indicators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/28—Methods of steam generation characterised by form of heating method in boilers heated electrically
    • F22B1/284—Methods of steam generation characterised by form of heating method in boilers heated electrically with water in reservoirs

Definitions

  • the present invention relates to a steam generator as defined in the preamble of claim 1.
  • a steam generator as defined in the preamble of claim 1.
  • Such a generator is known, for example, from document EP-A-0 323 939.
  • Steam generators generally include a main enclosure bounded by a sealed wall to contain water.
  • Water supply channeling means comprise a water inlet control solenoid valve, for introducing water into the enclosure through at least one water inlet orifice.
  • Steam extraction channeling means communicate with the upper part of the main enclosure by at least one steam outlet orifice.
  • Heating means connectable to an external source of energy, are arranged to heat the water contained in the main enclosure.
  • Control means control the heating means and the water inlet control solenoid valve as a function of input signals produced by means of detecting the water level in the main enclosure.
  • water level detection means are adapted to measure the water level and produce control signals for the water inlet solenoid valve.
  • the problem proposed by the present invention is to eliminate the drawbacks due to the presence of deposits of tartar or limescale appearing after a prolonged period of operation of the steam generator.
  • the invention also allows correct detection of the water level even in the presence of demineralized water.
  • the invention proposes to detect the level of water in the generator by special means for detecting the pressure produced by the water column present in the generator, these means being arranged so as to prevent any deposit of tartar.
  • a difficulty is, in particular, that the pressure detected depends on the pressure of the vapor produced.
  • the invention therefore proposes to provide means to compensate for the effects that may have on the measurement of water level the presence of a vapor pressure produced.
  • the means for detecting the water level are produced by particularly inexpensive components, making it possible to significantly reduce the production cost of a steam generator.
  • the volume of air, permanently interposed in the measurement chamber between the water and the pressure switch, is trapped in the measurement because the normal water level is above the lower communication orifice of the measurement enclosure. This avoids any contact between the water and the pressure switch. In particular, the formation of scale or lime deposits on the active elements of the pressure switch such as the pressure measurement membrane is avoided.
  • the detection is carried out by a pressure measurement, a measurement which is practically insensitive to the fact that the water is demineralized or not, and to the fact that lime or tartar deposits can form in certain parts of the generator.
  • the pressure that is measured is the pressure produced by the water column present in the generator above a reference level close to the pressure switch.
  • the volume of air provides thermal insulation between the pressure switch diaphragm and high temperature water.
  • the detection is carried out at a lower temperature, by the fact that the measurement enclosure is away from the main heated enclosure. As a result, no disturbing bubbling occurs in the measurement enclosure.
  • the pressure switch advantageously comprises an elastically deformable membrane situated entirely above the water level in the measurement enclosure, its first face being subjected to the air pressure prevailing inside the measurement enclosure, and its second face being subjected to the pressure prevailing in a balancing chamber.
  • the membrane is integral with electrical conductors forming switches which close and open as a function of the deformation of the membrane under the effect of the differential pressure between the measurement enclosure and the balancing chamber.
  • the balancing chamber is advantageously connected to the first orifice of a balancing pipe, the second orifice of which is connected to an upper orifice of the main enclosure, said upper orifice being disposed above the water level.
  • the balancing chamber is thus at the vapor pressure produced in the generator.
  • a steam generator according to the present invention comprises a main enclosure 1 bounded by a sealed wall to contain water.
  • the main enclosure 1 comprises a lower compartment 2 and an upper compartment 3.
  • the lower compartment 2 and the upper compartment 3 are connected to each other by a baffle 4, or transverse part, so that the lower compartment 2 and the upper compartment 3 are offset laterally with respect to each other.
  • the generator is intended to contain water up to an average level 5 preferably situated below the baffle 4, in the upper part of the lower compartment 2.
  • the upper compartment 3 is intended to contain steam , excluding water in the liquid phase.
  • the lower compartment 2 and the upper compartment 3 form a main chamber, which is itself connected to a secondary chamber 6 bypass on the main chamber.
  • the secondary chamber 6 is connected in branch between a lower communication orifice 7 located below the average water level 5 and an upper communication orifice 8 located above the average water level 5.
  • the secondary chamber 6 constitutes an area in which the water level is stable, as opposed to the water level in the main chamber which is subjected to the effects of turbulent convection of water during the production of steam.
  • the main enclosure 1, preferably in the upper compartment 3, is provided with a steam outlet orifice 9 connected to means of steam extraction duct not shown.
  • the steam outlet orifice 9 is formed in the upper part of the main enclosure.
  • Water supply channeling means comprising a water inlet control solenoid valve 10, make it possible to introduce water into the enclosure 1 through at least one water inlet orifice 11.
  • Heating means 12 are arranged to heat the water contained in the main enclosure. They are connectable to an external source of energy. Preferably, the means of heaters 12 are arranged to heat the water in the lower compartment 2 of the main enclosure 1.
  • Control means 13 make it possible to control the various functional members of the steam generator.
  • the control means 13 make it possible to establish or interrupt the transmission of electrical energy from a line 14 for supplying electrical energy to the heating means 12 to which they are connected by conductors 15.
  • the control means 13 also make it possible to establish or interrupt the supply of electrical energy to the solenoid valve 10 to which they are connected by a pair of conductors 16.
  • the control means 13 react according to input signals present on input conductors 17.
  • the generator according to the invention comprises a measurement enclosure 18, which has a lower orifice 19 for communication, and a pressure switch 20.
  • the pressure switch 20 is subjected to the pressure prevailing inside the measurement enclosure 18, and produces input signals on the input conductors 17 which transmit these signals to the control means 13.
  • a measurement line 21 has a first end connected to a measurement orifice 22 located in the lower part of the main enclosure 1 below the mean water level 5, and has a second end connected to said lower communication orifice 19 of the measurement enclosure 18. Said lower orifice 19 for communication is also located below the mean level 5 of the water in the main enclosure 1.
  • the measurement orifice 22 may advantageously be located in the lower part of the secondary chamber 6 of main enclosure 1.
  • the water level present in the measurement line 21 and the measurement enclosure 18 is situated substantially at the lower orifice 19 of communication of the measurement enclosure, and the pressure switch 20 is located in the upper part of the measurement enclosure, that is to say above the lower orifice 19 for communication. Air can therefore be introduced into the measurement chamber and remain trapped in the enclosure, without being able to escape through the communication orifice 19 closed by water. Thus, a volume of air is permanently interposed in the measurement enclosure 18, between the water and the pressure switch 20.
  • the pressure switch 20 comprises an elastically deformable membrane 23, the first face 24 is in contact with the air contained in the measurement chamber, and therefore subject to the pressure prevailing inside the measurement chamber 18, and the second face 25 of which is subjected to the pressure prevailing in a chamber d balancing 26.
  • the membrane 23 is integral with electrical conductors such as the conductors 27 and 28 forming switches which close and open as a function of the deformation of the membrane 23 under the effect of the differential pressure between the enclosure of measure 18 and the balancing chamber 26.
  • the balancing chamber 26 can be either a chamber sealed, containing a constant quantity of air capable of compressing or expanding as a function of the movements of the membrane 23, ie advantageously a chamber brought to atmospheric pressure by a vent not shown.
  • the pressure prevailing in the measurement enclosure 18 is equal to the vapor pressure prevailing above the average water level 5 in the main enclosure 1, increased by the pressure of the water column H situated between the level water means 5 and the water level in the lower orifice 19 of communication of the measurement enclosure.
  • the steam generator according to the invention further comprises draining means.
  • These draining means comprise a drain pipe 29 connected to a lower drain hole 30 of the main enclosure 1, and comprising a siphon 31 leading to an outlet hole 32.
  • a pump 33 is interposed in the drain pipe 29 and discharges into the siphon 31.
  • the siphon 31 is located at a higher level than the average level of the water 5 in the steam generator.
  • the embodiment of Figures 2 and 5 allows production of pressurized steam escaping through the steam outlet orifice 9.
  • the generator according to this embodiment comprises the same functional members as those of the embodiment of FIGS. 1 and 4. These functional members are identified by the same references digital, and include in particular: the main enclosure 1 with its lower compartment 2 and its upper compartment 3, the secondary chamber 6 connected in diversion between a lower communication orifice 7 and an upper communication orifice 8, the outlet orifice of steam 9, the water inlet control solenoid valve 10 through a water inlet orifice 11, the control means 13, the measurement enclosure 18 with the pressure switch 20, the drain pipe 29.
  • this embodiment of Figures 2 and 5 further comprises a balancing pipe 34 provided with a first port 35 and a second port 36.
  • the first port 35 is connected to a second measurement enclosure 180 of the pressure switch 20.
  • the second orifice 36 is connected to an upper orifice of the main enclosure 1, in a position such that the second orifice 36 is disposed above the average level of the water 5.
  • a solenoid valve 37 is optionally interposed in the balancing pipe 34, and controlled by the control means 13 to which it is connected by control conductors 38.
  • the pressure switch 20 comprises two elastically deformable membranes, namely the first membrane 23 such as that of the embodiment of FIG. 4, and a second membrane 123 parallel to the first membrane 23.
  • the electrical conductors 27 and 28 forming switches constitute mobile spacers moving with one and the other of the membranes 23 and 123, and open and close electrical contacts according to the deformation of the membranes under the effect of the differential pressure between the measurement enclosure 18 and the second measurement enclosure 180.
  • the electrical conductors 27 and 28 are thus isolated from the atmosphere prevailing both in the measurement enclosure 18 and in the second measurement enclosure 180.
  • the balancing 26 can advantageously be at atmospheric pressure.
  • the generator must further comprise a drain solenoid valve 39, interposed in the drain pipe 29, to open or close the water passage in the drain pipe 29.
  • the solenoid valve 39 prevents the production of vapor pressure causing the evacuation of water by the siphon 31 when the vapor pressure is greater than the weight of the water column between the average level of the water 5 and the siphon 31.
  • the solenoid valve 39 is controlled by the control means 13 to which it is connected by control conductors 40.
  • FIG. 3 shows an alternative embodiment of a steam generator according to the present invention for producing pressurized steam.
  • the generator comprises the same functional members as those described in relation to FIG. 1, with a main enclosure 1, the heating means 12, control means 13, a measurement enclosure 18, a pressure switch 20 providing input signals sent to the control means by input conductors 17, a pump 33 interposed in the drain pipe 29 provided with a siphon 31.
  • the drain pipe 29 also includes a drain solenoid valve 39 controlled by conductors 40 connecting it to the control means 13.
  • a balancing pipe 34 is connected by a second orifice 36 to the upper part of the main enclosure 1, as in the mode of embodiment of FIG. 2.
  • FIG. 3 shows an alternative embodiment of a steam generator according to the present invention for producing pressurized steam.
  • the generator comprises the same functional members as those described in relation to FIG. 1, with a main enclosure 1, the heating means 12, control means 13, a measurement enclosure 18, a pressure switch 20 providing input signals sent to the control means by input conductors 17, a pump 33 interposed in the
  • the first orifice 35 of the balancing pipe 34 is connected not to the second enclosure of me on 180 of the pressure switch 20, but at one of the inputs of a three-way solenoid valve 41 controlled by the control means 13 via conductors 42.
  • the three-way solenoid valve 41 is interposed between the pressure switch 20 and the measurement enclosure 18, as shown in the figure, and allows the pressure switch 20 to be placed in communication alternately with the pressure prevailing in the measurement enclosure 18 or the vapor pressure produced by the generator and supplied by the balancing pipe 34.
  • the pressure switch 20 advantageously provides input signals comprising at least four different signals corresponding respectively to four different levels of pressure in the measurement enclosure 18.
  • the four levels are shown in the figures pressure A, B, C and D.
  • the average level of water 5 in the generator is in the vicinity of level C.
  • the control means 13 supply the heating means 12 with electrical energy.
  • the level of the water tends to decrease as a result of the vaporization, and, when it drops below the level C, the control means 13 cause the solenoid valve 10 to open and the water to be introduced into the generator.
  • the level then rises above the average level C, and the control means 13 cause the solenoid valve 10 to close. If the solenoid valve 10 is not cut off, the water level reaches level D, which causes the emission of an anti-overflow safety signal and the closing of the solenoid valve 10.
  • the opening of the solenoid valve 10 would not be controlled by the usual means for regulating the water level in the vicinity of level C, the surface water reaches level B detected by the pressure switch 20.
  • the signal produced by the pressure switch then causes, by means of control 13, the interruption of supply to the heating means 12.
  • the control means 13 then cause the solenoid valve 10 to open for the introduction of water.
  • the solenoid valve 39 is closed in all the stages in which it is desired to produce steam under pressure, the solenoid valve 29 being only open in the emptying stages.
  • the solenoid valve 37 can be closed in the operating steps for production of fluent steam, and must be open in the operating steps for production of pressurized steam.
  • FIG. 6 represents a variant of the embodiment of FIG. 2. This variant incorporates the same functional elements, identified by the same reference numerals.
  • a separating means 134 is interposed in the balancing pipe 34.
  • the separating means 134 has the function of transmitting the pressure throughout the balancing pipe, and of preventing the vapor coming from the main enclosure 1 propagates towards the pressure switch 20.
  • the membrane of the pressure switch 20 is thus subjected to the balancing pressure, without however being in contact with the hot and aggressive steam.
  • the three-way solenoid valve 41 can have two operating modes: for the production of fluent vapor, the solenoid valve 41 can put the pressure switch 20 and the measurement chamber 18 in permanent communication; for the production of pressurized steam, the solenoid valve 41 alternately communicates the pressure switch 20 with either the measuring chamber 18 or the balancing pipe 34.

Description

La présente invention concerne un générateur de vapeur d'eau tel que défini dans le préambule de la revendication 1. Un tel générateur est connu, par exemple, du document EP-A-0 323 939.The present invention relates to a steam generator as defined in the preamble of claim 1. Such a generator is known, for example, from document EP-A-0 323 939.

Les générateurs de vapeur comprennent généralement une enceinte principale limitée par une paroi étanche pour contenir de l'eau. Des moyens de canalisation d'amenée d'eau comportent une électrovanne de commande d'entrée d'eau, pour introduire de l'eau dans l'enceinte par au moins un orifice d'entrée d'eau. Des moyens de canalisation d'extraction de vapeur communiquent avec la partie supérieure de l'enceinte principale par au moins un orifice de sortie de vapeur. Des moyens de chauffe, connectables à une source extérieure d'énergie, sont disposés pour chauffer l'eau contenue dans l'enceinte principale. Des moyens de commande assurent la commande des moyens de chauffe et de l'électrovanne de commande d'entrée d'eau en fonction de signaux d'entrée produits par des moyens de détection de niveau d'eau dans l'enceinte principale.Steam generators generally include a main enclosure bounded by a sealed wall to contain water. Water supply channeling means comprise a water inlet control solenoid valve, for introducing water into the enclosure through at least one water inlet orifice. Steam extraction channeling means communicate with the upper part of the main enclosure by at least one steam outlet orifice. Heating means, connectable to an external source of energy, are arranged to heat the water contained in the main enclosure. Control means control the heating means and the water inlet control solenoid valve as a function of input signals produced by means of detecting the water level in the main enclosure.

Dans les générateurs connus, on maintient un niveau d'eau sensiblement constant dans l'enceinte principale. Pour cela, des moyens de détection de niveau d'eau sont adaptés pour mesurer le niveau d'eau et produire des signaux de commande de l'électrovanne d'entrée d'eau.In known generators, a substantially constant water level is maintained in the main enclosure. For this, water level detection means are adapted to measure the water level and produce control signals for the water inlet solenoid valve.

Les moyens de détection de niveau d'eau habituellement utilisés sont de diverses sortes :

  • selon le document EP-A-0 323 939, la détection du niveau de l'eau est assurée par une sonde résistive, placée dans l'enceinte principale, et venant au contact du niveau supérieur de l'eau ;
  • selon une seconde réalisation, les moyens de chauffe comprennent des tubes chauffants verticaux creux, contenant l'eau à chauffer, et dont une partie supérieure est munie d'une sonde de mesure de température fixée sur la surface périphérique extérieure du tube ; l'abaissement du niveau d'eau au-dessous de la zone occupée par la sonde de mesure de température provoque une élévation de température de la paroi correspondante de tube, élévation détectée par la sonde de mesure de température ; l'élévation de température est interprétée comme un abaissement du niveau d'eau au-dessous du niveau autorisé ;
  • l'article LEVEL MONITORING, de Thomas C. Eliott, paru dans POWER N° 9 septembre 1990 page 41 et suivantes, enseigne de mesurer le niveau d'eau d'un générateur de vapeur par une jauge manométrique, sans toutefois donner de précisions sur les moyens utilisés ;
  • le document DE-C-662 932, enseigne depuis longtemps de mesurer le niveau d'eau d'un réservoir par un dispositif à membrane au contact de l'eau.
There are various types of water level detection means usually used:
  • according to document EP-A-0 323 939, the detection of the water level is ensured by a resistive probe, placed in the main enclosure, and coming into contact with the upper level of the water;
  • according to a second embodiment, the heating means comprise hollow vertical heating tubes, containing the water to be heated, and an upper part of which is provided with a temperature measurement probe fixed on the outer peripheral surface of the tube; the lowering of the water level below the zone occupied by the temperature measurement probe causes an increase in temperature of the corresponding wall of tube, rise detected by the temperature measurement probe; the rise in temperature is interpreted as a lowering of the water level below the authorized level;
  • the article LEVEL MONITORING, by Thomas C. Eliott, published in POWER N ° 9 September 1990 page 41 and following, teaches to measure the water level of a steam generator by a gauge, without however give details of the means used;
  • document DE-C-662 932 has long taught to measure the water level of a reservoir by a membrane device in contact with water.

Ces dispositifs de mesure du niveau de l'eau ont donné jusqu'à présent satisfaction, au moins pendant les premières périodes d'utilisation. Cependant, ces moyens connus présentent des inconvénients qui apparaissent soit dès le début de fonctionnement, soit à l'issue d'une période prolongée de fonctionnement.These water level measurement devices have so far been satisfactory, at least during the first periods of use. However, these known means have drawbacks which appear either from the start of operation, or after an extended period of operation.

Par exemple, la détection de niveau d'eau par une sonde résistive ne permet pas une détection correcte lorsque- l'on veut produire de la vapeur avec une eau déminéralisée. En effet, l'eau déminéralisée présente une résistivité trop grande pour assurer un fonctionnement correct de la sonde résistive.For example, detection of the water level by a resistive probe does not allow correct detection when you want to produce steam with demineralized water. In fact, demineralized water has too high a resistivity to ensure correct operation of the resistive probe.

En outre, tous les moyens connus, qu'ils soient à sonde résistive ou à détection de température ou de pression, sont particulièrement sensibles à la présence de dépôts de tartre ou de calcaire qui se forment inévitablement après une période d'utilisation plus ou moins longue du générateur de vapeur. Un dépôt de tartre ou de calcaire sur la sonde résistive modifie sensiblement les signaux électriques produits par la sonde. De même, un dépôt de tartre ou de calcaire sur la paroi intérieure d'un tube chauffant dans la zone occupée par la sonde de mesure de température modifie sensiblement le fonctionnement de ladite sonde, car la pellicule de tartre ou de calcaire constitue un isolant thermique. Le dépôt de tarte sur la membrane d'un manomètre modifie sensiblement les capacités de déformation de la membrane et affecte la précision de la détection.In addition, all known means, whether with a resistive probe or with temperature or pressure detection, are particularly sensitive to the presence of tartar or lime deposits which inevitably form after a period of use more or less length of the steam generator. A deposit of tartar or lime on the resistive probe appreciably modifies the electrical signals produced by the probe. Likewise, a deposit of tartar or lime on the inside wall of a heating tube in the area occupied by the temperature measurement probe appreciably modifies the functioning of said probe, because the film of tartar or lime constitutes a thermal insulator . The deposition of pie on the membrane of a manometer significantly modifies the deformation capacities of the membrane and affects the accuracy of detection.

Le problème proposé par la présente invention est de supprimer les inconvénients dus à la présence de dépôts de tartre ou de calcaire apparaissant à l'issue d'une période prolongée de fonctionnement du générateur de vapeur.The problem proposed by the present invention is to eliminate the drawbacks due to the presence of deposits of tartar or limescale appearing after a prolonged period of operation of the steam generator.

L'invention permet en outre une détection correcte de niveau d'eau même en présence d'eau déminéralisée.The invention also allows correct detection of the water level even in the presence of demineralized water.

Pour cela, l'invention propose de détecter le niveau de l'eau dans le générateur par des moyens particuliers de détection de la pression produite par la colonne d'eau présente dans le générateur, ces moyens étant agencés de façon à empêcher tout dépôt de tartre. Une difficulté est, notamment, que la pression détectée dépend de la pression de la vapeur produite. L'invention se propose donc de prévoir des moyens pour compenser les effets que peut avoir sur la mesure de niveau d'eau la présence d'une pression de vapeur produite.For this, the invention proposes to detect the level of water in the generator by special means for detecting the pressure produced by the water column present in the generator, these means being arranged so as to prevent any deposit of tartar. A difficulty is, in particular, that the pressure detected depends on the pressure of the vapor produced. The invention therefore proposes to provide means to compensate for the effects that may have on the measurement of water level the presence of a vapor pressure produced.

Selon un autre but de l'invention, les moyens de détection de niveau d'eau sont réalisés par des composants particulièrement peu onéreux, permettant de réduire sensiblement le coût de production d'un générateur de vapeur.According to another object of the invention, the means for detecting the water level are produced by particularly inexpensive components, making it possible to significantly reduce the production cost of a steam generator.

Pour atteindre ces objets ainsi que d'autres, le générateur de vapeur selon l'invention comprend :

  • une enceinte principale limitée par une paroi étanche pour contenir de l'eau,
  • des moyens de canalisation d'amenée d'eau comportant une électrovanne de commande d'entrée d'eau pour introduire de l'eau dans l'enceinte par au moins un orifice d'entrée d'eau,
  • des moyens de canalisation d'extraction de vapeur, communiquant avec la partie supérieure de l'enceinte principale par au moins un orifice de sortie de vapeur,
  • des moyens de chauffe, connectables à une source extérieure d'énergie, et disposés pour chauffer l'eau contenue dans l'enceinte principale,
  • des moyens de commande, pour commander les moyens de chauffe et l'électrovanne de commande d'entrée d'eau en fonction de signaux d'entrée sur des conducteurs d'entrée,
  • une enceinte de mesure pour la détection et la régulation du niveau de l'eau, comportant un orifice inférieur de communication situé au-dessous du niveau moyen de l'eau dans l'enceinte principale et raccordé à la seconde extrémité d'une canalisation de mesure dont la première extrémité est raccordée à un orifice de mesure situé en partie inférieure de l'enceinte principale au-dessous du niveau moyen de l'eau ;
  • l'enceinte de mesure est associée à un pressostat soumis à la pression régnant à l'intérieur de l'enceinte de mesure, le pressostat produisant lesdits signaux d'entrée en fonction de ladite pression et les envoyant aux moyens de commande,
  • un volume d'air est interposé en permanence dans l'enceinte de mesure entre l'eau et le pressostat.
To achieve these and other objects, the steam generator according to the invention comprises:
  • a main enclosure bounded by a watertight wall to contain water,
  • water supply channeling means comprising a water inlet control solenoid valve for introducing water into the enclosure through at least one water inlet orifice,
  • steam extraction ducting means, communicating with the upper part of the main enclosure by at least one steam outlet orifice,
  • heating means, connectable to an external source of energy, and arranged to heat the water contained in the main enclosure,
  • control means, for controlling the heating means and the water inlet control solenoid valve as a function of input signals on input conductors,
  • a measurement enclosure for detecting and regulating the water level, comprising a lower communication orifice situated below the average level of the water in the main enclosure and connected to the second end of a drainage pipe measurement, the first end of which is connected to a measurement orifice located in the lower part of the main enclosure below the average water level;
  • the measurement chamber is associated with a pressure switch subjected to the pressure prevailing inside the measurement chamber, the pressure switch producing said input signals as a function of said pressure and sending them to the control means,
  • a volume of air is permanently interposed in the measurement chamber between the water and the pressure switch.

Le volume d'air, interposé en permanence dans l'enceinte de mesure entre l'eau et le pressostat, se trouve piégé dans l'enceinte de mesure car le niveau normal d'eau est au-dessus de l'orifice inférieur de communication de l'enceinte de mesure. On évite ainsi tout contact entre l'eau et le pressostat. En particulier, on évite la formation de dépôts de tartre ou de calcaire sur les éléments actifs du pressostat tels que la membrane de mesure de pression.The volume of air, permanently interposed in the measurement chamber between the water and the pressure switch, is trapped in the measurement because the normal water level is above the lower communication orifice of the measurement enclosure. This avoids any contact between the water and the pressure switch. In particular, the formation of scale or lime deposits on the active elements of the pressure switch such as the pressure measurement membrane is avoided.

La détection s'effectue par une mesure de pression, mesure qui est pratiquement insensible au fait que l'eau soit déminéralisée ou non, et au fait que des dépôts de calcaire ou de tartre puissent se former dans certaines parties du générateur. La pression que l'on mesure est la pression produite par la colonne d'eau présente dans le générateur au-dessus d'un niveau de référence proche du pressostat.The detection is carried out by a pressure measurement, a measurement which is practically insensitive to the fact that the water is demineralized or not, and to the fact that lime or tartar deposits can form in certain parts of the generator. The pressure that is measured is the pressure produced by the water column present in the generator above a reference level close to the pressure switch.

En outre, le volume d'air assure une isolation thermique entre la membrane du pressostat et l'eau à température élevée.In addition, the volume of air provides thermal insulation between the pressure switch diaphragm and high temperature water.

Egalement, la détection s'effectue à température plus basse, par le fait que l'enceinte de mesure est à l'écart de l'enceinte principale chauffée. Il en résulte qu'aucun bouillonnement perturbateur ne se produit dans l'enceinte de mesure.Also, the detection is carried out at a lower temperature, by the fact that the measurement enclosure is away from the main heated enclosure. As a result, no disturbing bubbling occurs in the measurement enclosure.

Le pressostat comprend avantageusement une membrane élastiquement déformable située entièrement au-dessus du niveau d'eau dans l'enceinte de mesure, sa première face étant soumise à la pression d'air régnant à l'intérieur de l'enceinte de mesure, et sa seconde face étant soumise à la pression régnant dans une chambre d'équilibrage. La membrane est solidaire de conducteurs électriques formant commutateurs qui se ferment et s'ouvrent en fonction de la déformation de la membrane sous l'effet de la pression différentielle entre l'enceinte de mesure et la chambre d'équilibrage.The pressure switch advantageously comprises an elastically deformable membrane situated entirely above the water level in the measurement enclosure, its first face being subjected to the air pressure prevailing inside the measurement enclosure, and its second face being subjected to the pressure prevailing in a balancing chamber. The membrane is integral with electrical conductors forming switches which close and open as a function of the deformation of the membrane under the effect of the differential pressure between the measurement enclosure and the balancing chamber.

Dans le cas d'un générateur de vapeur devant délivrer une vapeur sous pression, la chambre d'équilibrage est avantageusement raccordée au premier orifice d'une canalisation d'équilibrage dont le second orifice est raccordé à un orifice supérieur de l'enceinte principale, ledit orifice supérieur étant disposé au-dessus du niveau de l'eau. La chambre d'équilibrage se trouve ainsi à la pression de vapeur produite dans le générateur.In the case of a steam generator having to deliver pressurized steam, the balancing chamber is advantageously connected to the first orifice of a balancing pipe, the second orifice of which is connected to an upper orifice of the main enclosure, said upper orifice being disposed above the water level. The balancing chamber is thus at the vapor pressure produced in the generator.

D'autres objets et avantages de la présente invention ressortiront de la description suivante de modes de réalisation particuliers, faite en relation avec les figures jointes, parmi lesquelles :

  • la figure 1 représente schématiquement la structure générale d'un générateur de vapeur d'eau selon la présente invention, dans un mode de réalisation pour production de vapeur fluente ;
  • la figure 2 représente la structure générale d'un générateur de vapeur d'eau selon l'invention, dans un mode de réalisation destiné à produire de la vapeur sous pression ;
  • la figure 3 illustre un autre mode de réalisation destiné à produire de la vapeur sous pression ;
  • la figure 4 illustre un détail de réalisation du pressostat utilisé dans le mode de réalisation de la figure 1 ;
  • la figure 5 illustre une réalisation possible de pressostat utilisé dans le mode de réalisation de la figure 2 ; et
  • la figure 6 illustre une variante du mode de réalisation de la figure 2.
Other objects and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which:
  • FIG. 1 schematically represents the general structure of a steam generator according to the present invention, in an embodiment for the production of fluent steam;
  • FIG. 2 represents the general structure of a steam generator according to the invention, in an embodiment intended to produce steam under pressure;
  • Figure 3 illustrates another embodiment for producing steam under pressure;
  • Figure 4 illustrates a detail of the pressure switch used in the embodiment of Figure 1;
  • FIG. 5 illustrates a possible embodiment of a pressure switch used in the embodiment of FIG. 2; and
  • Figure 6 illustrates a variant of the embodiment of Figure 2.

Comme le représentent les figures, un générateur de vapeur selon la présente invention comprend une enceinte principale 1 limitée par une paroi étanche pour contenir de l'eau.As shown in the figures, a steam generator according to the present invention comprises a main enclosure 1 bounded by a sealed wall to contain water.

Dans les modes de réalisation représentés, l'enceinte principale 1 comprend un compartiment inférieur 2 et un compartiment supérieur 3. Le compartiment inférieur 2 et le compartiment supérieur 3 se raccordent l'un à l'autre par une chicane 4, ou partie transversale, de sorte que le compartiment inférieur 2 et le compartiment supérieur 3 sont décalés latéralement l'un par rapport à l'autre. Le générateur est destiné à contenir de l'eau jusqu'à un niveau moyen 5 situé de préférence au-dessous de la chicane 4, dans la partie supérieure du compartiment inférieur 2. Ainsi, le compartiment supérieur 3 est destiné à contenir de la vapeur, à l'exclusion de l'eau en phase liquide.In the embodiments shown, the main enclosure 1 comprises a lower compartment 2 and an upper compartment 3. The lower compartment 2 and the upper compartment 3 are connected to each other by a baffle 4, or transverse part, so that the lower compartment 2 and the upper compartment 3 are offset laterally with respect to each other. The generator is intended to contain water up to an average level 5 preferably situated below the baffle 4, in the upper part of the lower compartment 2. Thus, the upper compartment 3 is intended to contain steam , excluding water in the liquid phase.

Dans le mode de réalisation représenté, le compartiment inférieur 2 et le compartiment supérieur 3 forment une chambre principale, qui est elle-même raccordée à une chambre secondaire 6 en dérivation sur la chambre principale. La chambre secondaire 6 est raccordée en dérivation entre un orifice de communication inférieur 7 situé au-dessous du niveau moyen de l'eau 5 et un orifice de communication supérieur 8 situé au-dessus du niveau moyen d'eau 5. La chambre secondaire 6 constitue une zone dans laquelle le niveau de l'eau est stable, par opposition au niveau de l'eau dans la chambre principale qui est soumise aux effets de convection turbulente de l'eau lors de la production de vapeur.In the embodiment shown, the lower compartment 2 and the upper compartment 3 form a main chamber, which is itself connected to a secondary chamber 6 bypass on the main chamber. The secondary chamber 6 is connected in branch between a lower communication orifice 7 located below the average water level 5 and an upper communication orifice 8 located above the average water level 5. The secondary chamber 6 constitutes an area in which the water level is stable, as opposed to the water level in the main chamber which is subjected to the effects of turbulent convection of water during the production of steam.

L'enceinte principale 1, de préférence dans le compartiment supérieur 3, est munie d'un orifice de sortie de vapeur 9 raccordé à des moyens de canalisation d'extraction de vapeur non représentés. L'orifice de sortie de vapeur 9 est ménagé dans la partie supérieure de l'enceinte principale.The main enclosure 1, preferably in the upper compartment 3, is provided with a steam outlet orifice 9 connected to means of steam extraction duct not shown. The steam outlet orifice 9 is formed in the upper part of the main enclosure.

Des moyens de canalisation d'amenée d'eau, comportant une électrovanne de commande d'entrée d'eau 10, permettent d'introduire de l'eau dans l'enceinte 1 par au moins un orifice d'entrée d'eau 11.Water supply channeling means, comprising a water inlet control solenoid valve 10, make it possible to introduce water into the enclosure 1 through at least one water inlet orifice 11.

Des moyens de chauffe 12, schématiquement représentés sur les figures sous forme de deux éléments thermoplongeurs, sont disposés pour chauffer l'eau contenue dans l'enceinte principale. Ils sont connectables à une source extérieure d'énergie. De préférence, les moyens de chauffe 12 sont disposés pour chauffer l'eau dans le compartiment inférieur 2 de l'enceinte principale 1.Heating means 12, schematically represented in the figures in the form of two immersion heaters, are arranged to heat the water contained in the main enclosure. They are connectable to an external source of energy. Preferably, the means of heaters 12 are arranged to heat the water in the lower compartment 2 of the main enclosure 1.

Des moyens de commande 13 permettent de commander les différents organes fonctionnels du générateur de production de vapeur. En particulier, les moyens de commande 13 permettent d'établir ou d'interrompre la transmission d'énergie électrique depuis une ligne 14 d'amenée d'énergie électrique jusqu'aux moyens de chauffe 12 auxquels ils sont raccordés par des conducteurs 15. Les moyens de commande 13 permettent également d'établir ou d'interrompre l'amenée d'énergie électrique à l'électrovanne 10 à laquelle ils sont raccordés par une paire de conducteurs 16. Les moyens de commande 13 réagissent en fonction de signaux d'entrée présents sur des conducteurs d'entrée 17.Control means 13 make it possible to control the various functional members of the steam generator. In particular, the control means 13 make it possible to establish or interrupt the transmission of electrical energy from a line 14 for supplying electrical energy to the heating means 12 to which they are connected by conductors 15. The control means 13 also make it possible to establish or interrupt the supply of electrical energy to the solenoid valve 10 to which they are connected by a pair of conductors 16. The control means 13 react according to input signals present on input conductors 17.

Le générateur selon l'invention comprend une enceinte de mesure 18, qui comporte un orifice inférieur 19 de communication, et un pressostat 20. Le pressostat 20 est soumis à la pression régnant à l'intérieur de l'enceinte de mesure 18, et produit des signaux d'entrée sur les conducteurs d'entrée 17 qui transmettent ces signaux aux moyens de commande 13.The generator according to the invention comprises a measurement enclosure 18, which has a lower orifice 19 for communication, and a pressure switch 20. The pressure switch 20 is subjected to the pressure prevailing inside the measurement enclosure 18, and produces input signals on the input conductors 17 which transmit these signals to the control means 13.

Une canalisation de mesure 21 comporte une première extrémité raccordée à un orifice de mesure 22 situé en partie inférieure de l'enceinte principale 1 au-dessous du niveau moyen de l'eau 5, et comporte une seconde extrémité raccordée audit orifice inférieur 19 de communication de l'enceinte de mesure 18. Ledit orifice inférieur 19 de communication est également situé au-dessous du niveau moyen 5 de l'eau dans l'enceinte principale 1. L'orifice de mesure 22 peut avantageusement être situé en partie inférieure de la chambre secondaire 6 d'enceinte principale 1.A measurement line 21 has a first end connected to a measurement orifice 22 located in the lower part of the main enclosure 1 below the mean water level 5, and has a second end connected to said lower communication orifice 19 of the measurement enclosure 18. Said lower orifice 19 for communication is also located below the mean level 5 of the water in the main enclosure 1. The measurement orifice 22 may advantageously be located in the lower part of the secondary chamber 6 of main enclosure 1.

Comme le représentent les figures, le niveau de l'eau présente dans la canalisation de mesure 21 et l'enceinte de mesure 18 est situé sensiblement à l'orifice inférieur 19 de communication de l'enceinte de mesure, et le pressostat 20 est situé en partie supérieure de l'enceinte de mesure c'est-à- dire au-dessus de l'orifice inférieur 19 de communication. De l'air peut donc être introduit dans la chambre de mesure et rester piégé dans l'enceinte, sans pouvoir s'échapper par l'orifice de communication 19 obturé par l'eau. Ainsi, un volume d'air est interposé en permanence dans l'enceinte de mesure 18, entre l'eau et le pressostat 20.As shown in the figures, the water level present in the measurement line 21 and the measurement enclosure 18 is situated substantially at the lower orifice 19 of communication of the measurement enclosure, and the pressure switch 20 is located in the upper part of the measurement enclosure, that is to say above the lower orifice 19 for communication. Air can therefore be introduced into the measurement chamber and remain trapped in the enclosure, without being able to escape through the communication orifice 19 closed by water. Thus, a volume of air is permanently interposed in the measurement enclosure 18, between the water and the pressure switch 20.

La structure des moyens de mesure de niveau d'eau du mode de réalisation de la figure 1 est représentée à plus grande échelle sur la figure 4. Dans ce mode de réalisation, le pressostat 20 comprend une membrane 23 élastiquement déformable dont la première face 24 est au contact de l'air contenu dans l'enceinte de mesure, et donc soumise à la pression régnant à l'intérieur de l'enceinte de mesure 18, et dont la seconde face 25 est soumise à la pression régnant dans une chambre d'équilibrage 26. La membrane 23 est solidaire de conducteurs électriques tels que les conducteurs 27 et 28 formant commutateurs qui se ferment et s'ouvrent en fonction de la déformation de la membrane 23 sous l'effet de la pression différentielle entre l'enceinte de mesure 18 et la chambre d'équilibrage 26.The structure of the water level measuring means of the embodiment of FIG. 1 is shown on a larger scale in FIG. 4. In this embodiment, the pressure switch 20 comprises an elastically deformable membrane 23, the first face 24 is in contact with the air contained in the measurement chamber, and therefore subject to the pressure prevailing inside the measurement chamber 18, and the second face 25 of which is subjected to the pressure prevailing in a chamber d balancing 26. The membrane 23 is integral with electrical conductors such as the conductors 27 and 28 forming switches which close and open as a function of the deformation of the membrane 23 under the effect of the differential pressure between the enclosure of measure 18 and the balancing chamber 26.

Dans le mode de réalisation des figures 1 et 4, dans lequel le générateur de vapeur d'eau est destiné à produire de la vapeur fluente s'échappant par l'orifice de sortie 9, la chambre d'équilibrage 26 peut être soit une chambre étanche, contenant une quantité d'air constante susceptible de se comprimer ou de se dilater en fonction des mouvements de la membrane 23, soit avantageusement une chambre mise à la pression atmosphérique par un évent non représenté. La pression régnant dans l'enceinte de mesure 18 est égale à la pression de vapeur régnant au-dessus du niveau moyen d'eau 5 dans l'enceinte principale 1, augmentée de la pression de la colonne d'eau H située entre le niveau moyen d'eau 5 et le niveau de l'eau dans l'orifice inférieur 19 de communication de l'enceinte de mesure. On comprend qu'une variation du niveau moyen de l'eau 5 induit une variation de la pression due à la colonne d'eau H, variation produisant un déplacement de la membrane 23 et des conducteurs électriques 27 et 28, produisant des signaux électriques envoyés aux moyens de commande 13 par les conducteurs d'entrée 17.In the embodiment of FIGS. 1 and 4, in which the steam generator is intended to produce fluent steam escaping through the outlet orifice 9, the balancing chamber 26 can be either a chamber sealed, containing a constant quantity of air capable of compressing or expanding as a function of the movements of the membrane 23, ie advantageously a chamber brought to atmospheric pressure by a vent not shown. The pressure prevailing in the measurement enclosure 18 is equal to the vapor pressure prevailing above the average water level 5 in the main enclosure 1, increased by the pressure of the water column H situated between the level water means 5 and the water level in the lower orifice 19 of communication of the measurement enclosure. It is understood that a variation in the average level of water 5 induces a variation in the pressure due to the water column H, a variation producing a displacement of the membrane 23 and of the electrical conductors 27 and 28, producing electrical signals sent to the control means 13 by the input conductors 17.

Dans le mode de réalisation représenté, le générateur de vapeur selon l'invention comprend en outre des moyens de vidange. Ces moyens de vidange comportent une canalisation de vidange 29 raccordée à un orifice inférieur de vidange 30 de l'enceinte principale 1, et comportant un siphon 31 conduisant à un orifice de sortie 32. Une pompe 33 est interposée dans la canalisation de vidange 29 et refoule dans le siphon 31. Le siphon 31 est situé à un niveau plus élevé que le niveau moyen de l'eau 5 dans le générateur de vapeur.In the embodiment shown, the steam generator according to the invention further comprises draining means. These draining means comprise a drain pipe 29 connected to a lower drain hole 30 of the main enclosure 1, and comprising a siphon 31 leading to an outlet hole 32. A pump 33 is interposed in the drain pipe 29 and discharges into the siphon 31. The siphon 31 is located at a higher level than the average level of the water 5 in the steam generator.

Le mode de réalisation des figures 2 et 5 permet la production de vapeur sous pression s'échappant par l'orifice de sortie de vapeur 9. Le générateur selon ce mode de réalisation comprend les mêmes organes fonctionnels que ceux du mode de réalisation des figures 1 et 4. Ces organes fonctionnels sont repérés par les mêmes références numériques, et comprennent notamment : l'enceinte principale 1 avec son compartiment inférieur 2 et son compartiment supérieur 3, la chambre secondaire 6 raccordée en dérivation entre un orifice de communication inférieur 7 et un orifice de communication supérieur 8, l'orifice de sortie de vapeur 9, l'électrovanne de commande d'entrée d'eau 10 par un orifice d'entrée d'eau 11, les moyens de commande 13, l'enceinte de mesure 18 avec le pressostat 20, la canalisation de vidange 29.The embodiment of Figures 2 and 5 allows production of pressurized steam escaping through the steam outlet orifice 9. The generator according to this embodiment comprises the same functional members as those of the embodiment of FIGS. 1 and 4. These functional members are identified by the same references digital, and include in particular: the main enclosure 1 with its lower compartment 2 and its upper compartment 3, the secondary chamber 6 connected in diversion between a lower communication orifice 7 and an upper communication orifice 8, the outlet orifice of steam 9, the water inlet control solenoid valve 10 through a water inlet orifice 11, the control means 13, the measurement enclosure 18 with the pressure switch 20, the drain pipe 29.

Par rapport au mode de réalisation précédent des figures 1 et 4, ce mode de réalisation des figures 2 et 5 comprend en outre une canalisation d'équilibrage 34 munie d'un premier orifice 35 et d'un second orifice 36. Le premier orifice 35 est raccordé à une seconde enceinte de mesure 180 du pressostat 20. Le second orifice 36 est raccordé à un orifice supérieur de l'enceinte principale 1, en une position telle que le second orifice 36 est disposé au-dessus du niveau moyen de l'eau 5. Une électrovanne 37 est éventuellement interposée dans la canalisation d'équilibrage 34, et commandée par les moyens de commande 13 auxquels elle est reliée par des conducteurs de commande 38.Compared to the previous embodiment of Figures 1 and 4, this embodiment of Figures 2 and 5 further comprises a balancing pipe 34 provided with a first port 35 and a second port 36. The first port 35 is connected to a second measurement enclosure 180 of the pressure switch 20. The second orifice 36 is connected to an upper orifice of the main enclosure 1, in a position such that the second orifice 36 is disposed above the average level of the water 5. A solenoid valve 37 is optionally interposed in the balancing pipe 34, and controlled by the control means 13 to which it is connected by control conductors 38.

Dans le mode de réalisation de la figure 5, le pressostat 20 comprend deux membranes élastiquement déformables, à savoir la première membrane 23 telle que celle du mode de réalisation de la figure 4, et une seconde membrane 123 parallèle à la première membrane 23. Les conducteurs électriques 27 et 28 formant commutateurs constituent des entretoises mobiles se déplaçant avec l'une et l'autre des membranes 23 et 123, et ouvrent et ferment des contacts électriques en fonction de la déformation des membranes sous l'effet de la pression différentielle entre l'enceinte de mesure 18 et la seconde enceinte de mesure 180. Les conducteurs électriques 27 et 28 se trouvent ainsi isolés de l'atmosphère régnant tant dans l'enceinte de mesure 18 que dans la seconde enceinte de mesure 180. La chambre d'équilibrage 26 peut avantageusement être à la pression atmosphérique.In the embodiment of FIG. 5, the pressure switch 20 comprises two elastically deformable membranes, namely the first membrane 23 such as that of the embodiment of FIG. 4, and a second membrane 123 parallel to the first membrane 23. The electrical conductors 27 and 28 forming switches constitute mobile spacers moving with one and the other of the membranes 23 and 123, and open and close electrical contacts according to the deformation of the membranes under the effect of the differential pressure between the measurement enclosure 18 and the second measurement enclosure 180. The electrical conductors 27 and 28 are thus isolated from the atmosphere prevailing both in the measurement enclosure 18 and in the second measurement enclosure 180. The balancing 26 can advantageously be at atmospheric pressure.

Dans ce mode de réalisation des figures 2 et 5, le générateur doit comprendre en outre une électrovanne de vidange 39, interposée dans la canalisation de vidange 29, pour ouvrir ou fermer le passage d'eau dans la canalisation de vidange 29. L'électrovanne 39 évite que la production de pression de vapeur provoque l'évacuation d'eau par le siphon 31 lorsque la pression de vapeur est supérieure au poids de la colonne d'eau entre le niveau moyen de l'eau 5 et le siphon 31. L'électrovanne 39 est commandée par les moyens de commande 13 auxquels elle est reliée par des conducteurs de commande 40.In this embodiment of Figures 2 and 5, the generator must further comprise a drain solenoid valve 39, interposed in the drain pipe 29, to open or close the water passage in the drain pipe 29. The solenoid valve 39 prevents the production of vapor pressure causing the evacuation of water by the siphon 31 when the vapor pressure is greater than the weight of the water column between the average level of the water 5 and the siphon 31. The solenoid valve 39 is controlled by the control means 13 to which it is connected by control conductors 40.

La figure 3 représente une variante de réalisation d'un générateur de vapeur selon la présente invention pour production de vapeur sous pression. Dans ce mode de réalisation, le générateur comprend les mêmes organes fonctionnels que ceux décrits en relation avec la figure 1, avec une enceinte principale 1, les moyens chauffants 12, des moyens de commande 13, une enceinte de mesure 18, un pressostat 20 fournissant des signaux d'entrée envoyés aux moyens de commande par des conducteurs d'entrée 17, une pompe 33 interposée dans la canalisation de vidange 29 munie d'un siphon 31. Dans ce mode de réalisation de la figure 3, la canalisation de vidange 29 comprend également une électrovanne de vidange 39 commandée par des conducteurs 40 la reliant aux moyens de commande 13. Egalement, une canalisation d'équilibrage 34 est raccordée par un second orifice 36 à la partie supérieure de l'enceinte principale 1, comme dans le mode de réalisation de la figure 2. Toutefois, dans ce mode de réalisation de la figure 3, le premier orifice 35 de la canalisation d'équilibrage 34 est raccordé non pas à la seconde enceinte de mesure 180 du pressostat 20, mais à l'une des entrées d'une électrovanne à trois voies 41 commandée par les moyens de commande 13 par l'intermédiaire de conducteurs 42. L'électrovanne trois voies 41 est interposée entre le pressostat 20 et l'enceinte de mesure 18, comme le représente la figure, et permet de mettre en communication le pressostat 20 alternativement avec la pression régnant dans l'enceinte de mesure 18 ou la pression de vapeur produite par le générateur et amenée par la canalisation d'équilibrage 34.FIG. 3 shows an alternative embodiment of a steam generator according to the present invention for producing pressurized steam. In this embodiment, the generator comprises the same functional members as those described in relation to FIG. 1, with a main enclosure 1, the heating means 12, control means 13, a measurement enclosure 18, a pressure switch 20 providing input signals sent to the control means by input conductors 17, a pump 33 interposed in the drain pipe 29 provided with a siphon 31. In this embodiment of FIG. 3, the drain pipe 29 also includes a drain solenoid valve 39 controlled by conductors 40 connecting it to the control means 13. Also, a balancing pipe 34 is connected by a second orifice 36 to the upper part of the main enclosure 1, as in the mode of embodiment of FIG. 2. However, in this embodiment of FIG. 3, the first orifice 35 of the balancing pipe 34 is connected not to the second enclosure of me on 180 of the pressure switch 20, but at one of the inputs of a three-way solenoid valve 41 controlled by the control means 13 via conductors 42. The three-way solenoid valve 41 is interposed between the pressure switch 20 and the measurement enclosure 18, as shown in the figure, and allows the pressure switch 20 to be placed in communication alternately with the pressure prevailing in the measurement enclosure 18 or the vapor pressure produced by the generator and supplied by the balancing pipe 34.

Dans tous les modes de réalisation, le pressostat 20 fournit avantageusement des signaux d'entrée comportant au moins quatre signaux différents correspondant respectivement à quatre niveaux différents de pression dans l'enceinte de mesure 18. On a représenté, sur les figures, les quatre niveaux de pression A, B, C et D.In all the embodiments, the pressure switch 20 advantageously provides input signals comprising at least four different signals corresponding respectively to four different levels of pressure in the measurement enclosure 18. The four levels are shown in the figures pressure A, B, C and D.

Les moyens de commande 13 sont adaptés pour :

  • commander l'ouverture de l'électrovanne d'arrivée d'eau 10 en présence d'un signal d'entrée correspondant à une pression plus faible que celle produite par la hauteur H de colonne d'eau lorsque le niveau d'eau est égal au niveau inférieur A ; la vanne peut être refermée dès que le niveau A est atteint, à moins qu'un ordre d'ouverture supplémentaire soit produit par d'autres moyens ci-après ;
  • autoriser la mise en fonction des moyens de chauffe 12 en présence d'un signal d'entrée correspondant à une pression plus grande que celle produite par la colonne d'eau H lorsque le niveau d'eau est égal au niveau intermédiaire B, et interdire le fonctionnement des moyens de chauffe 12 lorsque le signal d'entrée indique une pression plus faible ;
  • commander la mise en fonction des moyens de chauffe 12 et la fermeture de l'électrovanne d'arrivée d'eau 10 en présence d'un signal d'entrée correspondant à une pression plus grande que celle produite par la colonne d'eau H lorsque le niveau d'eau est au niveau intermédiaire haut C, et interrompre le fonctionnement des moyens de chauffe 12 et ouvrir l'électrovanne d'arrivée d'eau 10 lorsque le signal d'entrée indique une pression plus faible ;
  • commander la fermeture de l'électrovanne d'arrivée d'eau 10 en présence d'un signal d'entrée correspondant à une pression plus grande que celle produite par la hauteur de colonne d'eau lorsque le niveau d'eau est au niveau supérieur D.
The control means 13 are adapted for:
  • command the opening of the water inlet solenoid valve 10 in the presence an input signal corresponding to a pressure lower than that produced by the height H of the water column when the water level is equal to the lower level A; the valve can be closed as soon as level A is reached, unless an additional opening order is produced by other means below;
  • authorize the heating means 12 to operate in the presence of an input signal corresponding to a pressure greater than that produced by the water column H when the water level is equal to the intermediate level B, and prohibit the operation of the heating means 12 when the input signal indicates a lower pressure;
  • control the activation of the heating means 12 and the closing of the water inlet solenoid valve 10 in the presence of an input signal corresponding to a pressure greater than that produced by the water column H when the water level is at the high intermediate level C, and interrupt the operation of the heating means 12 and open the water inlet solenoid valve 10 when the input signal indicates a lower pressure;
  • control the closing of the water inlet solenoid valve 10 in the presence of an input signal corresponding to a pressure greater than that produced by the height of the water column when the water level is at the higher level D.

En fonctionnement normal, le niveau moyen de l'eau 5 dans le générateur est au voisinage du niveau C. Les moyens de commande 13 assurent l'alimentation des moyens de chauffe 12 en énergie électrique. Le niveau de l'eau tend à diminuer par suite de la vaporisation, et, lorsqu'il descend en dessous du niveau C, les moyens de commande 13 provoquent l'ouverture de l'électrovanne 10 et l'introduction d'eau dans le générateur. Le niveau remonte alors au-dessus du niveau moyen C, et les moyens de commande 13 provoquent la fermeture de l'électrovanne 10. En cas de non coupure de l'électrovanne 10, le niveau d'eau atteint le niveau D, qui provoque l'émission d'un signal de sécurité anti-débordement et la fermeture de l'électrovanne 10.In normal operation, the average level of water 5 in the generator is in the vicinity of level C. The control means 13 supply the heating means 12 with electrical energy. The level of the water tends to decrease as a result of the vaporization, and, when it drops below the level C, the control means 13 cause the solenoid valve 10 to open and the water to be introduced into the generator. The level then rises above the average level C, and the control means 13 cause the solenoid valve 10 to close. If the solenoid valve 10 is not cut off, the water level reaches level D, which causes the emission of an anti-overflow safety signal and the closing of the solenoid valve 10.

Dans le cas où, lors d'une diminution du niveau moyen de l'eau 5, l'ouverture de l'électrovanne 10 ne serait pas commandée par les moyens habituels de régulation du niveau d'eau au voisinage du niveau C, la surface de l'eau atteint le niveau B détecté par le pressostat 20. Le signal produit par le pressostat provoque alors, par les moyens de commande 13, l'interruption d'alimentation des moyens de chauffe 12. En cas de diminution ultérieure du niveau de l'eau, pouvant atteindre le niveau A, les moyens de commande 13 provoquent alors l'ouverture de l'électrovanne 10 pour l'introduction d'eau.In the event that, during a decrease in the average water level 5, the opening of the solenoid valve 10 would not be controlled by the usual means for regulating the water level in the vicinity of level C, the surface water reaches level B detected by the pressure switch 20. The signal produced by the pressure switch then causes, by means of control 13, the interruption of supply to the heating means 12. In the event of a subsequent reduction in the water level, which may reach level A, the control means 13 then cause the solenoid valve 10 to open for the introduction of water.

En outre, dans le mode de réalisation des figures 2 et 3, l'électrovanne 39 est fermée dans toutes les étapes dans lesquelles on veut produire de la vapeur sous pression, l'électrovanne 29 n'étant ouverte que dans les étapes de vidange.Furthermore, in the embodiment of FIGS. 2 and 3, the solenoid valve 39 is closed in all the stages in which it is desired to produce steam under pressure, the solenoid valve 29 being only open in the emptying stages.

Dans le mode de réalisation de la figure 2, l'électrovanne 37 peut être fermée dans les étapes de fonctionnement pour production de vapeur fluente, et doit être ouverte dans les étapes de fonctionnement pour production de vapeur sous pression.In the embodiment of Figure 2, the solenoid valve 37 can be closed in the operating steps for production of fluent steam, and must be open in the operating steps for production of pressurized steam.

La figure 6 représente une variante du mode de réalisation de la figure 2. Cette variante reprend les mêmes éléments fonctionnels, repérés par les mêmes références numériques. En outre, un moyen séparateur 134 est interposé dans la canalisation d'équilibrage 34. Le moyen séparateur 134 a pour fonction de transmettre la pression dans toute la canalisation d'équilibrage, et d'empêcher que la vapeur provenant de l'enceinte principale 1 se propage vers le pressostat 20. La membrane du pressostat 20 est ainsi soumise à la pression d'équilibrage, sans toutefois être au contact de la vapeur chaude et agressive.FIG. 6 represents a variant of the embodiment of FIG. 2. This variant incorporates the same functional elements, identified by the same reference numerals. In addition, a separating means 134 is interposed in the balancing pipe 34. The separating means 134 has the function of transmitting the pressure throughout the balancing pipe, and of preventing the vapor coming from the main enclosure 1 propagates towards the pressure switch 20. The membrane of the pressure switch 20 is thus subjected to the balancing pressure, without however being in contact with the hot and aggressive steam.

Dans le mode de réalisation de la figure 3, l'électrovanne à trois voies 41 peut avoir deux modes de fonctionnement : pour la production de vapeur fluente, l'électrovanne 41 peut mettre en communication permanente le pressostat 20 et la chambre de mesure 18 ; pour la production de vapeur sous pression, l'électrovanne 41 met en communication alternativement le pressostat 20 avec soit la chambre de mesure 18 soit la canalisation d'équilibrage 34.In the embodiment of FIG. 3, the three-way solenoid valve 41 can have two operating modes: for the production of fluent vapor, the solenoid valve 41 can put the pressure switch 20 and the measurement chamber 18 in permanent communication; for the production of pressurized steam, the solenoid valve 41 alternately communicates the pressure switch 20 with either the measuring chamber 18 or the balancing pipe 34.

Claims (8)

  1. Steam generator comprising :
    - a main vessel (1) bounded by a watertight wall to contain water,
    - water inlet pipework including a water inlet control solenoid valve (10) to inject water into the vessel via at least one water inlet opening (11),
    - steam outlet pipework that communicates with the upper part of the main vessel (1) via at least one steam outlet opening (9),
    - heating devices (12) that can be connected to an external energy source and are positioned to heat the water contained in the main vessel (1),
    - control devices (13) to control the heating devices (12) and solenoid valve (10) to control water inlet as a function of input signals on input conductors (17),
    - a measuring vessel (18) for the detection and the regulation of the water level, comprising a lower communicating opening (19) situated below the average water level (5) in the main vessel (1) and connected to the second end of a measuring pipework (21) the first end of which is connected to a measuring opening (22) located in the lower part of the main vessel (1) below the average water level (5), characterized in that :
    - the measuring vessel (18) is associated with a pressure switch (20) that is exposed to the pressure inside the measuring vessel (18), the pressure switch (20) generating said input signals as a function of said pressure and sending them to the control devices (13),
    - a volume of air in the measuring vessel (18) is continuously trapped between the water and pressure switch (20).
  2. Water generator as claimed in claim 1, characterized in that the pressure switch (20) has at least one diaphragm (23) capable of elastic deformation having its first face (24) exposed to the pressure inside the measuring vessel (18) and its second face (25) exposed to the pressure inside a balancing chamber (26), said diaphragm (23) being connected to electrical conductors (27, 28) that form switches which close and open depending on the deformation of the diaphragm (23) under the effects of the pressure difference between the measuring vessel (18) and the balancing chamber (26).
  3. Steam generator as claimed in claim 2, characterized in that a second measuring vessel (180) is connected to a first opening (35) of balancing pipework (34) a second opening (36) of which is connected to an upper opening in the main vessel (1), said second opening (36) being situated above the average water level (5) in the main vessel.
  4. Steam generator as claimed in claim 2, characterized in that a 3-way valve (41) is fitted between the measuring vessel (18) and the pressure switch (20) in order to selectively connect the pressure switch (20) either to the atmosphere inside said measuring vessel (18) or to a first opening (35) of a balancing pipework (34) a second opening (36) of which is connected to an upper opening in the main vessel (1), said second opening (36) being situated above the average water level (5) and said 3-way valve (41) being controlled by control devices (13).
  5. Steam generator as claimed in any of claims 1 to 4, characterized in that the pressure switch (20) generates input signals comprising at least four different signals which correspond respectively to four different pressure levels (A, B, C, D) in the measuring vessel (18).
  6. Steam generator as claimed in claim 5, characterized in that the control devices (13) are suitable to :
    - order the opening of the water inlet control solenoid valve (10) in the presence of an input signal corresponding to a pressure lower than that produced by the height of water (H) if the water level equals a lower level (A) with the valve being closed again as soon as the level (A) is reached, unless an additional opening command signal is generated by other devices stated below ;
    - enable the switching on of the heating devices (12) in the presence of an input signal corresponding to a pressure higher than that produced by the height of water (H) if the water level equals the intermediate level (B) and prevent operation of the heating devices (12) if the input signal indicates a lower pressure ;
    - order the switching on of the heating devices (12) and the closing of the water inlet solenoid valve (10) in the presence of an input signal corresponding to a pressure higher than that produced by the height of water (H) if the water level is at the upper intermediate level (C) and switch off the heating devices (12) and open the water inlet solenoid valve (10) if the input signal indicates a lower pressure ;
    - order the closing of the water inlet control solenoid valve (10) in the presence of an input signal corresponding to a pressure higher than that produced by the height of water if the water level is at the upper level (D).
  7. Steam generator as claimed in any of claims 1 to 6, characterized in that the main vessel (1) has a main chamber containing the heating devices (12) and the steam outlet opening (9), and has a secondary chamber (6) connected in parallel to the main chamber between a lower communicating opening (7) situated below the average water level (5) and an upper communicating opening (8) situated above the average water level (5), said secondary chamber (6) containing said measuring opening (22) which is connected to the measuring pipework (21).
  8. Steam generator as claimed in any of claims 1 to 7, characterized in that it also has means of draining consisting of drain pipework (29) connected to a lower drain opening (30) in the main vessel (1) and equipped with a pump (33) that discharges into a water seal (31) and is associated with a solenoid valve (39).
EP92420190A 1991-06-10 1992-06-05 Pressure regulated steam generator Expired - Lifetime EP0518788B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9107265 1991-06-10
FR9107265A FR2677434A1 (en) 1991-06-10 1991-06-10 PILOT STEAM GENERATOR BY PRESSURE SWITCH.

Publications (2)

Publication Number Publication Date
EP0518788A1 EP0518788A1 (en) 1992-12-16
EP0518788B1 true EP0518788B1 (en) 1996-02-28

Family

ID=9413828

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92420190A Expired - Lifetime EP0518788B1 (en) 1991-06-10 1992-06-05 Pressure regulated steam generator

Country Status (4)

Country Link
US (1) US5355840A (en)
EP (1) EP0518788B1 (en)
DE (1) DE69208532T2 (en)
FR (1) FR2677434A1 (en)

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT241540Y1 (en) * 1996-01-31 2001-05-09 Irca Spa ATMOSPHERIC PRESSURE STEAM GENERATOR
US6107605A (en) * 1997-09-12 2000-08-22 Middleby-Marshall, Inc. Pressure regulator for steam oven
FI980562A (en) * 1998-03-13 1999-09-14 Amsco Europ Inc Suomen Sivulii Method and apparatus for measuring the wastewater flow from a steam generator or distillator
US5979372A (en) * 1998-11-09 1999-11-09 Daewoo Electronics Co., Ltd. Method of sensing malfunctions of a water supply system for a boiler and apparatus thereof
KR100540749B1 (en) * 2003-08-13 2006-01-10 엘지전자 주식회사 Steam generator for drum-type washing machine
US7096828B2 (en) * 2003-08-29 2006-08-29 American Griddle Corporation Self cleaning boiler and steam generator
US20070068791A1 (en) * 2003-12-02 2007-03-29 Thom Douglas M Automated water processing control system
JP2007512953A (en) * 2003-12-02 2007-05-24 シルバン ソース、 インク． Fully automated water treatment control system
US7678235B2 (en) * 2005-10-19 2010-03-16 Sylvan Source, Inc. Water purification system
US7418960B2 (en) * 2004-09-30 2008-09-02 Premark Feg Llc Steam cooker and related superheater
US7353821B2 (en) * 2004-11-24 2008-04-08 Premark Feg L.L.C. Steam oven system having steam generator with controlled fill process
US7537004B2 (en) * 2005-05-03 2009-05-26 Whirlpool Corporation Steam oven with fluid supply and drain vessel
US20060251784A1 (en) * 2005-05-03 2006-11-09 Sells Joel M Method for cooking meat using steam
US20060251785A1 (en) 2005-05-06 2006-11-09 Stefania Fraccon Method for cooking food using steam
JP3868464B1 (en) * 2005-07-26 2007-01-17 シャープ株式会社 Cooker
DE102006029578A1 (en) * 2006-06-20 2008-01-03 E.G.O. Elektro-Gerätebau GmbH Evaporator device, evaluation device and method for operating an evaporator device
US7867534B2 (en) 2006-10-18 2011-01-11 Whirlpool Corporation Cooking appliance with steam generator
DE102008035787B4 (en) * 2007-08-03 2023-07-20 Lg Electronics Inc. Steam generator and clothes treatment machine and dishwasher with a steam generator
US20090136640A1 (en) * 2007-11-26 2009-05-28 Whirlpool Corporation Method for Baking a Casserole Using Steam
US8207477B2 (en) * 2007-11-26 2012-06-26 Whirlpool Corporation Method for cooking vegetables using steam
US9788679B2 (en) 2015-06-29 2017-10-17 Whirlpool Corporation Steam generation system for use in cooking appliance
CA3014561A1 (en) * 2017-08-22 2019-02-22 Technologies Steamovap Inc. Steam generator

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE662932C (en) * 1938-07-25 Hydraulik G M B H Piston and floatless compressed air accumulator
CH130758A (en) * 1928-01-31 1928-12-31 Hch Meier Karl Water level indicator for high pressure steam boiler.
US2270608A (en) * 1941-05-22 1942-01-20 Arthur F Sandberg Circuit controller
US2718218A (en) * 1952-07-24 1955-09-20 Howard A Gray Boiler and control system therefor
US4336825A (en) * 1980-06-17 1982-06-29 Factory Mutual Research Corporation Liquid level control system
CH656203A5 (en) * 1982-03-15 1986-06-13 Schoenmann Wilfred Ernst Steam boiler with electric resistance heating
FR2625794B1 (en) * 1988-01-08 1990-05-04 Bourgeois Ste Coop Production WATER VAPOR GENERATOR FOR COOKING APPLIANCE

Also Published As

Publication number Publication date
US5355840A (en) 1994-10-18
FR2677434A1 (en) 1992-12-11
DE69208532D1 (en) 1996-04-04
EP0518788A1 (en) 1992-12-16
DE69208532T2 (en) 1996-10-10

Similar Documents

Publication Publication Date Title
EP0518788B1 (en) Pressure regulated steam generator
WO1993019237A1 (en) Steam iron with device for detecting and removing scale
EP0518787A1 (en) Boiler with deformable wall
FR2601665A1 (en) SEPARATE AIR RETURN FILLING DEVICE
EP0718861B1 (en) Electric safety interrupter
EP0872201B1 (en) Electric boiler
EP0177400B1 (en) Liquid tank with a floating roof, such as a storage tank used in the electronuclear field
EP0122194B1 (en) Hydraulic valve for low-level gas pressure differences
EP1153277B1 (en) Packaging with continuous leak monitoring
EP0528726B1 (en) Process and apparatus for controlling a pumping station and modular detection device for such a station
FR2583141A1 (en) Steam generator with an electric element for household device.
EP0110448A1 (en) Washing machine for laundry or the like with a safety or alarm device in case the drain hose drops on the floor
EP0178210B1 (en) Liquid tank with a floating roof, such as a storage tank used in the electronuclear field
FR2539435A3 (en) Boiler water feed valve
EP0328457A1 (en) Vacuum sewage transport method, vacuum sewage transport system and delay controlling device for use in this system
EP0084992B1 (en) Manometric capsule security and commanding apparatus for instant gas apparatuses
EP0582531B1 (en) Method for testing the tightness of a drain channel or a network of drain channels and installation for carrying out the method
FR2596786A1 (en) Device for emptying a liquid-containing tank, particularly water-flushing device for a W.C. bowl
EP1107083A1 (en) Water flooding protection device for an apparatus comprising a snorkel and being placed in an underground casing
FR2691233A1 (en) Domestic and industrial steam generator with immediate response - has intermediate chamber connected to storage tank during demand periods only, and to boiler only when idling.
FR2541748A1 (en) Safety valve for keeping a containment enclosure ventilated
EP3674492A1 (en) Submersible waste macerator
FR2500579A1 (en) Automatic air bleed for water pipe - has pressure balancing chamber with membrane seal for float valve
EP0170754B1 (en) Degasing, cleaning, blocking and recuperating combination with enhanced security for measuring apparatus
EP0032347A2 (en) Automatic sprinkler device for the containment of a pressurized-water reactor

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE ES FR GB IT LI LU MC NL PT SE

17P Request for examination filed

Effective date: 19930503

17Q First examination report despatched

Effective date: 19950119

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE ES FR GB IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19960228

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19960228

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19960228

REF Corresponds to:

Ref document number: 69208532

Country of ref document: DE

Date of ref document: 19960404

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Effective date: 19960528

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19960531

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19960522

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Effective date: 19960630

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19960630

Ref country code: LI

Effective date: 19960630

Ref country code: CH

Effective date: 19960630

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19980630

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990630

BERE Be: lapsed

Owner name: SOC. COOPERATIVE DE PRODUCTION BOURGEOIS (SOC. CO

Effective date: 19990630

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20070614

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20070521

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20070629

Year of fee payment: 16

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20080605

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20090228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090101

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080605

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080630