WO1994021924A1 - Pressurisation/partial vacuum pump for delivering predetermined amounts of a product - Google Patents

Pressurisation/partial vacuum pump for delivering predetermined amounts of a product Download PDF

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Publication number
WO1994021924A1
WO1994021924A1 PCT/IB1994/000035 IB9400035W WO9421924A1 WO 1994021924 A1 WO1994021924 A1 WO 1994021924A1 IB 9400035 W IB9400035 W IB 9400035W WO 9421924 A1 WO9421924 A1 WO 9421924A1
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WO
WIPO (PCT)
Prior art keywords
product
tank
chamber
pump
pump according
Prior art date
Application number
PCT/IB1994/000035
Other languages
French (fr)
Inventor
Bernard Amrhein
Original Assignee
C.A.T. Cybernetique Automatisme Telecommunication S.A.R.L.
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 C.A.T. Cybernetique Automatisme Telecommunication S.A.R.L. filed Critical C.A.T. Cybernetique Automatisme Telecommunication S.A.R.L.
Priority to AU61144/94A priority Critical patent/AU6114494A/en
Priority to EP94907656A priority patent/EP0689647B1/en
Priority to DE69407274T priority patent/DE69407274T2/en
Publication of WO1994021924A1 publication Critical patent/WO1994021924A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
    • F04F1/00—Pumps using positively or negatively pressurised fluid medium acting directly on the liquid to be pumped
    • F04F1/02—Pumps using positively or negatively pressurised fluid medium acting directly on the liquid to be pumped using both positively and negatively pressurised fluid medium, e.g. alternating

Definitions

  • the present invention relates to a pump using an air vacuum to suck from a supply duct a predetermined quantity of product, such as a liquid, a viscous, granulated or lumpy material, then an air pressure for return this quantity to a discharge pipe.
  • a predetermined quantity of product such as a liquid, a viscous, granulated or lumpy material
  • Such a pump is advantageously used, for example, in the transfer of exact amounts of corrosive products, such as salts in an electrolysis bath used for surface treatment, or in the supply of industrial washing machines in powdered form. washing, or dosing of liquid in water treatment.
  • a known pump of this type for transferring battery acid is described in document SU 626 251.
  • This pump comprises a sealed chamber provided at its bottom with a butterfly drainage valve and at its upper face with a valve float.
  • An adjacent vacuum pump establishes a partial vacuum in this chamber, which draws the liquid from an associated reservoir.
  • the float opens the upper valve which restores atmospheric pressure within the chamber then stopping the arrival of the liquid.
  • the weight of the liquid is sufficient to open the drainage valve allowing the evacuation of the liquid from below.
  • the suction pump begins to establish a new vacuum for the next cycle.
  • Another pump operating on a similar mechanism is described in document SU 676,761.
  • the accuracy based on the lifting of a float may prove to be insufficient for precise dosing, especially if the pump is incorporated in a machine undergoing vibrations.
  • the upward movement of the float may be hampered by the friction forces along its guide rod, in particular when transferring viscous or granular products.
  • the object of the present invention is a metering pump operating by vacuum then overpressure, which ensures better precision in the quantity of product transferred, and this with increased reliability thanks to a simplification of the constituent parts.
  • a pump comprising a hermetic chamber into which a product arriving by a first conduit can be sucked in when an air vacuum is applied through a mouthpiece by an air pump, because the product is received in an internal tank held by a weighing sensor delivering an electrical signal representative of the product weight, this signal being applied to an electronic air pump control unit, the product being discharged, when an air overpressure is then applied in the chamber by the air pump, in a second vertical evacuation conduit whose lower end is located at the bottom of the tank.
  • the chamber and the tank can be two nested coaxial cylindrical elements.
  • the bottom of the tank is concave conical.
  • the tank is made of a material inert to corrosion such as glass or polyvinyl chloride. Its upper edge may advantageously have a collar oriented inwardly to significantly reduce the risk of product overflowing.
  • the hermetic chamber can be made of any waterproof and mechanically resistant material, in particular of molded and / or assembled plastic elements.
  • This chamber may include a removable top cover for possible cleaning. So the first supply lines and the second discharge duct may be integral with this cover which they pass through.
  • the second discharge pipe is fitted with a non-return valve to prevent part of the product from returning to the pump when the overpressure disappears.
  • the supply pipe can be connected to a plurality of valves mounted in parallel to control the supply of different products, and the discharge pipe can also be connected to a plurality of valves controlling the outlet of the product dosed to different destinations.
  • the weighing sensor consists of a parallelepipedal block of metal partially hollowed out in its center, and on the upper and / or lower face of which a stress gauge has been stuck, one end being fixed at a fixed point of the hermetic chamber, the other end supporting the tank.
  • the weighing sensor can be based on a piezoelectric crystal with two opposite electrodes.
  • the metering pump comprises an external chamber 10 hermetically closed by a cover 12 tightening a seal 14.
  • a tank 20 supported by a weighing sensor 30.
  • a first product supply conduit 16 passes through the cover 12 and stops in the upper part of the tank 20.
  • a second product discharge conduit 18 passes through the same cover 12 and extends until at the bottom of the same tank 20.
  • the airtight chamber 10 can be put under overpressure and then under vacuum by an air pump 32 connected to a mouth 19 of the chamber 10 either by two separate lines P and D or the same line common.
  • the chamber 10 and the tank 20 are cylindrical, the tank 20 being arranged in the chamber 10 coaxially. This tank has a concave conical bottom 22, the lower end of the discharge conduit 18 then being located at its lowest level. If desired, the tank 20 can be partially closed at its upper edge by a flange 24 extending radially inward.
  • the tank 20 can be made to receive corrosive products, it is preferred to make it from a chemically inert material such as glass.
  • a chemically inert material such as glass.
  • certain polyvinyl chlorides prove to be preferable.
  • the external chamber must be sealed and mechanically solid to resist variations in internal pressure as well as vibrations that may potentially exist in the machines in which the pump is intended to be installed. We can consider, to achieve this room, a molded or stamped metal.
  • certain thermosetting plastics or synthetic resin can prove to be sufficiently solid while being lighter and less expensive to produce.
  • the weighing is insensitive to variations in internal pressure of chamber 10, it is necessary that these variations can have repercussions as much on the upper face as on the lower face of this tank. It is therefore necessary to provide a sufficient passage for the air between the external walls of the tank and the internal walls of the chamber, and to provide air access over practically the entire bottom of this tank.
  • the chamber 10 can have an external diameter of 160 mm for a height of 190 mm cover included, while the tank is reduced to a diameter of 100 mm for a height of 110 mm.
  • the weighing sensor 30 is produced from a substantially parallelepipedal metal block and hollowed out longitudinally in its center, the ends of the recess being rounded. This horizontal sensor is then fixed at one of its ends to the bottom of the chamber 10 while its other end supports the tank 20.
  • One or more strain gauges are bonded to the upper and / or lower face of the metal block. These strain gauges are connected to an electronic unit 50 controlling the function of the air pump 32.
  • the inlet duct 16 is connected to at least one solenoid valve making it possible to close this duct at will, and this by remote control of the control circuit 50.
  • this duct 16 can be connected to a plurality of connected solenoid valves 34 in parallel then allowing the transfer of different products from several neighboring tanks.
  • the discharge conduit 18 is firstly provided with a non-return valve 38.
  • This valve can be housed in the lower part of the conduit 18 near the concave bottom 22 of the tank 20.
  • the outlet of this discharge conduit is also controlled by one or more solenoid valves 36 allowing, always under the control of the circuit 50, to modify the destination of the transferred product.
  • the metering pump according to the invention operates in the following manner.
  • the control circuit 50 reads the initial weight of the tank 20 as seen by the gauge 30. Then, the circuit 50 opens one of the valves 34 and starts the air pump 32 to create a depression of the order of 100 to 200 mm of water. This has the effect of sucking the product which, emerging through the conduit 16, accumulates in the tank 10. The increase in the weight of this tank is monitored by the control circuit 50 constantly reading the electrical signal from the sensor 30.
  • the circuit 50 closes the solenoid valve 34, stops the air pump 32 and restores the atmospheric pressure inside the chamber 10. Then, this same circuit opens the 'one of the outlet solenoid valves 36 and switches on the same air pump 32 to create an overpressure in the chamber 10. This overpressure is applied on top of the product present in the tank 10, and forces it to be evacuated by the second conduit 18. In view of the position of the end of this conduit in the concave bottom 22 of the tank, this product is entirely removed. Indeed, shortly before the end, the overpressure begins to escape through this same conduit 18 which then functions as a vacuum cleaner for the final quantities of product. The non-return valve 38 then prevents any backtracking when the control circuit 50 stops the pump 32 and restores atmospheric pressure. A new dosing product transfer cycle can then start again.
  • the tank 20 could be held by a plurality of weighing sensors installed between its upper edge and the cover 12.
  • the advantage of this metering pump according to the invention is the use of electronic weighing sensors ensuring precision of remarkable measure. Indeed, whatever the electronic sensor used, it can be calibrated by first carrying out a no-load measurement, giving the initial weight of the tank, then by measuring a predetermined quantity of a reference material of known weight . The electronic circuit 50 can then calculate an offset value and a gain value to be applied to the electrical signal to obtain the rigorous measurement of the weight of the only product subsequently transferred. In the event of vibrations, the circuit establishes an average of the values recorded during a unit of time, and decides based on this average. Many variants and improvements can be made to this metering pump in the context of the invention.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Manipulator (AREA)
  • Manufacturing Of Micro-Capsules (AREA)
  • Jet Pumps And Other Pumps (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Vacuum Packaging (AREA)
  • Beverage Vending Machines With Cups, And Gas Or Electricity Vending Machines (AREA)

Abstract

A pump including a sealed chamber (10) which can suck in a product feed through a first inlet (16) by means of an air pump (32) forming a partial air vacuum therein via a port (19). The product is received in an inner vessel (20) supported on a weight sensor (30) which outputs an electrical signal representative of the product weight. The signal is fed to an electronic air pump control unit (50). Once the product has reached the desired weight, it is discharged by the air pump pressurising said chamber, the product exiting through a vertical outlet (18) with its lower end at the bottom of the vessel.

Description

POMPE A DEPRESSION ET SURPRESSION POUR DEBITER DES QUANTITES PREDETERMINEES DE PRODUITS VACUUM AND OVERPRESSURE PUMP FOR DELIVERING PREDETERMINED QUANTITIES OF PRODUCTS
La présente invention est relative à une pompe utilisant une dépression d'air pour aspirer d'un conduit d'alimentation une quantité prédéterminée de produit, tel qu'un liquide, une matière visqueuse, granulée ou grumeleuse, puis une surpression d'air pour refouler cette quantité dans un conduit d'évacuation.The present invention relates to a pump using an air vacuum to suck from a supply duct a predetermined quantity of product, such as a liquid, a viscous, granulated or lumpy material, then an air pressure for return this quantity to a discharge pipe.
Une telle pompe est avantageusement utilisée, par exemple, dans le transfert de quantités exactes de produits corrosifs, tels que des sels dans un bain d'électrolyse utilisé pour le traitement de surface, ou dans l'alimentation de machines à laver industrielles en poudre de lavage, ou le dosage de liquide dans le traitement de l'eau.Such a pump is advantageously used, for example, in the transfer of exact amounts of corrosive products, such as salts in an electrolysis bath used for surface treatment, or in the supply of industrial washing machines in powdered form. washing, or dosing of liquid in water treatment.
Une pompe connue de ce type pour le transfert d'acide de batterie est décrite dans le document SU 626 251. Cette pompe comprend une chambre hermétique munie en son fond d'une valve de drainage à papillon et en sa face supérieure d'une valve à flotteur. Une pompe à vide adjacente permet d'établir un vide partiel dans cette chambre, ce qui aspire le liquide d'un réservoir connexe. Lorsque le niveau du liquide a atteint un seuil préétabli, le flotteur ouvre la valve supérieure qui rétablit la pression atmosphérique au sein de la chambre arrêtant alors l'arrivée du liquide. Par contre, le poids du liquide suffit a ouvrir la valve de drainage permettant l'évacuation du liquide par le bas. Une fois le flotteur abaissé et la valve supérieure fermée, la pompe aspirante recommence à établir une nouvelle dépression pour le cycle suivant. Une autre pompe fonctionnant sur un mécanisme similaire est décrit dans le document SU 676 761.A known pump of this type for transferring battery acid is described in document SU 626 251. This pump comprises a sealed chamber provided at its bottom with a butterfly drainage valve and at its upper face with a valve float. An adjacent vacuum pump establishes a partial vacuum in this chamber, which draws the liquid from an associated reservoir. When the liquid level has reached a pre-established threshold, the float opens the upper valve which restores atmospheric pressure within the chamber then stopping the arrival of the liquid. On the other hand, the weight of the liquid is sufficient to open the drainage valve allowing the evacuation of the liquid from below. Once the float is lowered and the upper valve closed, the suction pump begins to establish a new vacuum for the next cycle. Another pump operating on a similar mechanism is described in document SU 676,761.
Toutefois, la précision basée sur la levée d'un flotteur peut s'avérer insuffisante pour des dosages précis, surtout si la pompe est incorporée dans une machine subissant des vibrations. Par ailleurs, le mouvement ascendant du flotteur peut être gêné par les forces de friction le long de sa tige de guidage, notamment à l'occasion de transfert de produits visqueux ou granuleux.However, the accuracy based on the lifting of a float may prove to be insufficient for precise dosing, especially if the pump is incorporated in a machine undergoing vibrations. Furthermore, the upward movement of the float may be hampered by the friction forces along its guide rod, in particular when transferring viscous or granular products.
Le but de la présente invention est une pompe doseuse fonctionnant par dépression puis surpression, laquelle assure une meilleure précision dans la quantité de produit transféré, et ce avec une fiabilité accrue grâce à une simplification des pièces constituantes.The object of the present invention is a metering pump operating by vacuum then overpressure, which ensures better precision in the quantity of product transferred, and this with increased reliability thanks to a simplification of the constituent parts.
Ces buts sont atteints grâce à une pompe comprenant une chambre hermétique dans laquelle peut être aspiré un produit arrivant par un premier conduit lorsqu'une dépression d'air est appliquée au travers d'une embouchure par une pompe à air, du fait que le produit est reçu dans une cuve interne tenue par un capteur de pesage délivrant un signal électrique représentatif du poids de produit, ce signal étant appliqué à une unité électronique de contrôle de la pompe à air, le produit étant refoulé, lorsqu'une surpression d'air est ensuite appliquée dans la chambre par la pompe à air, dans un second conduit d'évacuation vertical dont l'extrémité inférieure se situe au fond de la cuve.These aims are achieved by means of a pump comprising a hermetic chamber into which a product arriving by a first conduit can be sucked in when an air vacuum is applied through a mouthpiece by an air pump, because the product is received in an internal tank held by a weighing sensor delivering an electrical signal representative of the product weight, this signal being applied to an electronic air pump control unit, the product being discharged, when an air overpressure is then applied in the chamber by the air pump, in a second vertical evacuation conduit whose lower end is located at the bottom of the tank.
Avantageusement, la chambre et la cuve peuvent être deux éléments cylindriques coaxiaux emboîtés. De préférence, le fond de la cuve est conique concave.Advantageously, the chamber and the tank can be two nested coaxial cylindrical elements. Preferably, the bottom of the tank is concave conical.
Utilement, la cuve est réalisée en un matériau inerte à la corrosion tel que du verre ou du chlorure de polyvinyle. Son bord supérieur peut avantageusement présenter une collerette orientée vers l'intérieur pour diminuer sensiblement les risques de débordement du produit.Usefully, the tank is made of a material inert to corrosion such as glass or polyvinyl chloride. Its upper edge may advantageously have a collar oriented inwardly to significantly reduce the risk of product overflowing.
La chambre hermétique peut être réalisée en tout matériau étanche et mécaniquement résistant, notamment en éléments plastiques moulés et/ou assemblés. Cette chambre peut comprendre un couvercle supérieur démontable pour nettoyage éventuel. Alors, les premiers conduits d'amenée et le second conduit d'évacuation peuvent être solidaires de ce couvercle qu'ils traversent.The hermetic chamber can be made of any waterproof and mechanically resistant material, in particular of molded and / or assembled plastic elements. This chamber may include a removable top cover for possible cleaning. So the first supply lines and the second discharge duct may be integral with this cover which they pass through.
Utilement, le second conduit d'évacuation est muni d'un clapet anti-retour pour éviter qu'une partie du produit ne revienne dans la pompe lors de la disparition de la surpression. Utilement encore, le conduit d'amenée peut être connecté à une pluralité de valves montées en parallèle pour contrôler 1'apport de produits différents, et le conduit d'évacuation peut également être connecté à une pluralité de valves contrôlant la sortie du produit dosé vers différentes destinations.Usefully, the second discharge pipe is fitted with a non-return valve to prevent part of the product from returning to the pump when the overpressure disappears. Also usefully, the supply pipe can be connected to a plurality of valves mounted in parallel to control the supply of different products, and the discharge pipe can also be connected to a plurality of valves controlling the outlet of the product dosed to different destinations.
Par exemple, le capteur de pesage est constitué d'un bloc parallélépipédique de métal partiellement évidé en son centre, et sur la face supérieure et/ou inférieure duquel a été collée une jauge de contrainte, une extrémité étant fixée en un point fixe de la chambre hermétique, l'autre extrémité supportant la cuve. Autrement, le capteur de pesage peut être basé sur un cristal piézo-électrique garni de deux électrodes opposées.For example, the weighing sensor consists of a parallelepipedal block of metal partially hollowed out in its center, and on the upper and / or lower face of which a stress gauge has been stuck, one end being fixed at a fixed point of the hermetic chamber, the other end supporting the tank. Alternatively, the weighing sensor can be based on a piezoelectric crystal with two opposite electrodes.
L'invention sera mieux comprise à l'étude d'un mode de réalisation pris à titre d'exemple nullement limitatif et illustré en coupe schématique sur la figure annexée.The invention will be better understood from the study of an embodiment taken by way of nonlimiting example and illustrated in schematic section in the appended figure.
Comme illustré, la pompe doseuse comprend une chambre externe 10 fermée hermétiquement par un couvercle 12 serrant un joint d'étanchéité 14. Dans cette chambre est installée une cuve 20 supportée par un capteur de pesage 30.As illustrated, the metering pump comprises an external chamber 10 hermetically closed by a cover 12 tightening a seal 14. In this chamber is installed a tank 20 supported by a weighing sensor 30.
Un premier conduit d'amenée 16 de produit traverse le couvercle 12 et s'arrête dans la partie supérieure de la cuve 20. A l'inverse, un second conduit d'évacuation 18 de produit traverse le même couvercle 12 et se prolonge jusqu'au fond de la même cuve 20. Par ailleurs, la chambre hermétique 10 peut être mise en surpression puis en dépression par une pompe à air 32 reliée à une embouchure 19 de la chambre 10 soit par deux lignes distinctes P et D ou une même ligne commune. Dans le mode de réalisation illustré sur cette figure, la chambre 10 et la cuve 20 sont cylindriques, la cuve 20 étant disposée dans la chambre 10 coaxialement. Cette cuve présente un fond 22 conique concave, l'extrémité inférieure du conduit d'évacuation 18 étant alors située en son niveau le plus bas. Si désiré, la cuve 20 peut être partiellement fermée en son bord supérieur par une collerette 24 s'étendant radialement vers l'intérieur.A first product supply conduit 16 passes through the cover 12 and stops in the upper part of the tank 20. Conversely, a second product discharge conduit 18 passes through the same cover 12 and extends until at the bottom of the same tank 20. Furthermore, the airtight chamber 10 can be put under overpressure and then under vacuum by an air pump 32 connected to a mouth 19 of the chamber 10 either by two separate lines P and D or the same line common. In the embodiment illustrated in this figure, the chamber 10 and the tank 20 are cylindrical, the tank 20 being arranged in the chamber 10 coaxially. This tank has a concave conical bottom 22, the lower end of the discharge conduit 18 then being located at its lowest level. If desired, the tank 20 can be partially closed at its upper edge by a flange 24 extending radially inward.
La cuve 20 pouvant être amenée à recevoir des produits corrosifs, on préfère la réaliser en un matériau chimiquement inerte tel que le verre. Toutefois, pour des considérations de légèreté et de solidité, certains polychlorures de vinyle s'avèrent préférables. La chambre externe doit par contre être étanche et mécaniquement solide pour résister aux variations de pression interne ainsi qu'aux vibrations pouvant potentiellement exister dans les machines dans lesquelles la pompe est prévue d'être installée. On peut envisager, pour réaliser cette chambre, un métal moulé ou embouti. Toutefois, certains plastiques thermodurcissables ou en résine synthétique peuvent s'avérer suffisamment solides tout en étant plus légers et moins onéreux à réaliser.Since the tank 20 can be made to receive corrosive products, it is preferred to make it from a chemically inert material such as glass. However, for considerations of lightness and strength, certain polyvinyl chlorides prove to be preferable. The external chamber, on the other hand, must be sealed and mechanically solid to resist variations in internal pressure as well as vibrations that may potentially exist in the machines in which the pump is intended to be installed. We can consider, to achieve this room, a molded or stamped metal. However, certain thermosetting plastics or synthetic resin can prove to be sufficiently solid while being lighter and less expensive to produce.
Pour que le capteur 30 puisse mesurer effectivement le poids de la cuve, il est important que celle-ci ne vienne pas en contact frictionnel avec les parois internes de la chambre 10. De plus, pour que le pesage soit insensible aux variations de pression interne de la chambre 10, il est nécessaire que ces variations puissent se répercuter autant sur la face supérieure que sur la face inférieure de cette cuve. Il convient donc de prévoir un passage suffisant pour l'air entre les parois externes de la cuve et les parois internes de la chambre, et de prévoir un accès de l'air sur pratiquement la totalité du fond de cette cuve.So that the sensor 30 can effectively measure the weight of the tank, it is important that it does not come into frictional contact with the internal walls of the chamber 10. In addition, so that the weighing is insensitive to variations in internal pressure of chamber 10, it is necessary that these variations can have repercussions as much on the upper face as on the lower face of this tank. It is therefore necessary to provide a sufficient passage for the air between the external walls of the tank and the internal walls of the chamber, and to provide air access over practically the entire bottom of this tank.
A titre d'exemple, la chambre 10 peut présenter un diamètre externe de 160 mm pour une hauteur de 190 mm couvercle compris, alors que la cuve est réduite à un diamètre de 100 mm pour une hauteur de 110 mm.By way of example, the chamber 10 can have an external diameter of 160 mm for a height of 190 mm cover included, while the tank is reduced to a diameter of 100 mm for a height of 110 mm.
Tel qu'illustré, le capteur de pesage 30 est réalisé à partir d'un bloc métallique sensiblement parallélépipédique et évidé longitudinalement en son centre, les extrémités de l'évidement étant arrondies. Ce capteur horizontal est alors fixé en l'une de ses extrémités au fond de la chambre 10 alors que son autre extrémité supporte la cuve 20. Une ou plusieurs jauges de contrainte sont collées sur la face supérieure et/ou inférieure du bloc métallique. Ces jauges de contrainte sont reliées à une unité électronique 50 contrôlant la fonction de la pompe à air 32.As illustrated, the weighing sensor 30 is produced from a substantially parallelepipedal metal block and hollowed out longitudinally in its center, the ends of the recess being rounded. This horizontal sensor is then fixed at one of its ends to the bottom of the chamber 10 while its other end supports the tank 20. One or more strain gauges are bonded to the upper and / or lower face of the metal block. These strain gauges are connected to an electronic unit 50 controlling the function of the air pump 32.
Par ailleurs, le conduit d'entrée 16 est relié à au moins une électrovanne permettant de fermer à volonté ce conduit, et ce par télécommande du circuit de contrôle 50. Mieux, ce conduit 16 peut être relié à une pluralité d'électrovannes 34 branchées en parallèle permettant alors de transférer des produits différents issus de plusieurs réservoirs voisins.Furthermore, the inlet duct 16 is connected to at least one solenoid valve making it possible to close this duct at will, and this by remote control of the control circuit 50. Better still, this duct 16 can be connected to a plurality of connected solenoid valves 34 in parallel then allowing the transfer of different products from several neighboring tanks.
D'autre part, le conduit d'évacuation 18 est d'abord muni d'un clapet anti-retour 38. Ce clapet peut être logé dans la partie inférieure du conduit 18 proche du fond concave 22 de la cuve 20. La sortie de ce conduit d'évacuation est également contrôlée par une ou plusieurs électrovannes 36 permettant, toujours sous le contrôle du circuit 50, de modifier la destination du produit transféré.On the other hand, the discharge conduit 18 is firstly provided with a non-return valve 38. This valve can be housed in the lower part of the conduit 18 near the concave bottom 22 of the tank 20. The outlet of this discharge conduit is also controlled by one or more solenoid valves 36 allowing, always under the control of the circuit 50, to modify the destination of the transferred product.
Tel que décrit, la pompe doseuse selon l'invention fonctionne de la manière suivante.As described, the metering pump according to the invention operates in the following manner.
Lors de la phase d'initialisation, le circuit de contrôle 50 lit le poids initial de la cuve 20 tel que vu par la jauge 30. Puis, le circuit 50 ouvre l'une des valves 34 et enclenche la pompe à air 32 pour créer une dépression de l'ordre de 100 à 200 mm d'eau. Ceci a pour effet d'aspirer le produit qui, débouchant par le conduit 16, s'accumule dans la cuve 10. L'augmentation du poids de cette cuve est surveillée par le circuit de contrôle 50 lisant en permanence le signal électrique issu du capteur 30.During the initialization phase, the control circuit 50 reads the initial weight of the tank 20 as seen by the gauge 30. Then, the circuit 50 opens one of the valves 34 and starts the air pump 32 to create a depression of the order of 100 to 200 mm of water. This has the effect of sucking the product which, emerging through the conduit 16, accumulates in the tank 10. The increase in the weight of this tank is monitored by the control circuit 50 constantly reading the electrical signal from the sensor 30.
Lorsqu'un poids prédéterminé de produit est mesuré dans la cuve 10, le circuit 50 ferme 1'électrovanne 34, arrête la pompe à air 32 et rétablit la pression atmosphérique à l'intérieur de la chambre 10. Puis, ce même circuit ouvre l'une des électrovannes de sortie 36 et enclenche la même pompe à air 32 pour créer une surpression dans la chambre 10. Cette surpression s'applique sur le dessus du produit présent dans la cuve 10, et force celui-ci à s'évacuer par le second conduit 18. Compte-tenu de la position de l'extrémité de ce conduit dans le fond concave 22 de la cuve, ce produit est entièrement évacué. En effet, peu avant la fin, la surpression commence à s'échapper par ce même conduit 18 qui fonctionne alors comme un aspirateur pour les ultimes quantités de produit. La valve anti-retour 38 empêche alors tout retour en arrière lorsque le circuit de contrôle 50 arrête la pompe 32 et rétablit la pression atmosphérique. Un nouveau cycle de transfert de produit dosé peut alors recommencer.When a predetermined weight of product is measured in the tank 10, the circuit 50 closes the solenoid valve 34, stops the air pump 32 and restores the atmospheric pressure inside the chamber 10. Then, this same circuit opens the 'one of the outlet solenoid valves 36 and switches on the same air pump 32 to create an overpressure in the chamber 10. This overpressure is applied on top of the product present in the tank 10, and forces it to be evacuated by the second conduit 18. In view of the position of the end of this conduit in the concave bottom 22 of the tank, this product is entirely removed. Indeed, shortly before the end, the overpressure begins to escape through this same conduit 18 which then functions as a vacuum cleaner for the final quantities of product. The non-return valve 38 then prevents any backtracking when the control circuit 50 stops the pump 32 and restores atmospheric pressure. A new dosing product transfer cycle can then start again.
En alternative, la cuve 20 pourrait être tenue par une pluralité de capteurs de pesage installés entre son bord supérieur et le couvercle 12. L'intérêt de cette pompe doseuse selon l'invention est l'utilisation de capteurs électroniques de pesage assurant une précision de mesure remarquable. En effet, quel que soit le capteur électronique utilisé, on peut en effectuer une calibration en effectuant d'abord une mesure à vide, donnant le poids initial de la cuve, puis en mesurant une quantité prédéterminée d'un matériau de référence de poids connu. Le circuit électronique 50 peut alors calculer une valeur de décalage et une valeur de gain à appliquer au signal électrique pour obtenir la mesure rigoureuse du poids du seul produit ultérieurement transféré. En cas de vibrations, le circuit établit une moyenne des valeurs relevées pendant une unité de temps, et décide en fonction de cette moyenne. De nombreuses variantes et améliorations peuvent être apportées à cette pompe doseuse dans le cadre de l'invention. Alternatively, the tank 20 could be held by a plurality of weighing sensors installed between its upper edge and the cover 12. The advantage of this metering pump according to the invention is the use of electronic weighing sensors ensuring precision of remarkable measure. Indeed, whatever the electronic sensor used, it can be calibrated by first carrying out a no-load measurement, giving the initial weight of the tank, then by measuring a predetermined quantity of a reference material of known weight . The electronic circuit 50 can then calculate an offset value and a gain value to be applied to the electrical signal to obtain the rigorous measurement of the weight of the only product subsequently transferred. In the event of vibrations, the circuit establishes an average of the values recorded during a unit of time, and decides based on this average. Many variants and improvements can be made to this metering pump in the context of the invention.

Claims

REVENDICATIONS
1. Pompe comprenant une chambre hermétique (10) dans laquelle peut être aspiré un produit arrivant par un premier conduit (16) lorsqu'une dépression d'air est appliquée au travers d'une embouchure (19) par une pompe à air (32), caractérisée en ce que le produit est reçu dans une cuve interne (20) tenue par un capteur de pesage (30) délivrant un signal électrique représentatif du poids de produit, ce signal étant appliqué à une unité électronique de contrôle (50) de la pompe à air, le produit étant refoulé, lorsqu'une surpression d'air est ensuite appliquée dans la chambre (10) par la pompe à air, dans un second conduit d'évacuation (18) vertical dont l'extrémité inférieure se situe au fond de la cuve.1. Pump comprising a sealed chamber (10) into which a product arriving by a first conduit (16) can be sucked when an air vacuum is applied through a mouthpiece (19) by an air pump (32 ), characterized in that the product is received in an internal tank (20) held by a weighing sensor (30) delivering an electrical signal representative of the product weight, this signal being applied to an electronic control unit (50) the air pump, the product being discharged, when an air pressure is then applied in the chamber (10) by the air pump, in a second vertical exhaust duct (18) whose lower end is located at the bottom of the tank.
2. Pompe selon la revendication 1, caractérisée en ce que la chambre (10) et la cuve (20) sont deux éléments cylindriques coaxiaux emboîtés.2. Pump according to claim 1, characterized in that the chamber (10) and the tank (20) are two nested coaxial cylindrical elements.
3. Pompe selon la revendication 1, caractérisée en ce que le fond (22) de la cuve (20) est conique concave.3. Pump according to claim 1, characterized in that the bottom (22) of the tank (20) is concave conical.
4. Pompe selon la revendication 1, caractérisée en ce que la cuve (20) est réalisée en un matériau inerte à la corrosion, et en ce que la chambre hermétique (10) est réalisée en éléments plastiques moulés et/ou assemblés.4. Pump according to claim 1, characterized in that the tank (20) is made of a material inert to corrosion, and in that the hermetic chamber (10) is made of molded and / or assembled plastic elements.
5. Pompe selon la revendication 1, caractérisée en ce que le bord supérieur de la cuve (20) présente une collerette (24) orientée vers l'intérieur.5. Pump according to claim 1, characterized in that the upper edge of the tank (20) has a collar (24) oriented inward.
6. Pompe selon la revendication 1, caractérisée en ce que la chambre (10) comprend un couvercle supérieur (14) démontable, et en ce que le premier conduit d'amenée (16) et le second conduit d'évacuation (18) sont solidaires de ce couvercle qu'ils traversent. 6. Pump according to claim 1, characterized in that the chamber (10) comprises a removable top cover (14), and in that the first supply duct (16) and the second discharge duct (18) are integral with this cover which they pass through.
7. Pompe selon la revendication 1, caractérisée en ce que le second conduit d'évacuation (18) est muni d'un clapet anti-retour (38).7. Pump according to claim 1, characterized in that the second discharge conduit (18) is provided with a non-return valve (38).
8. Pompe selon la revendication 1, caractérisée en ce que le conduit d'amenée (16) est connecté à une pluralité de valves (34) montées en parallèle pour contrôler l'apport de produits différents, et/ou le conduit d'évacuation (18) est connecté à une pluralité de valves (36) pour contrôler la sortie du produit dosé vers différentes destinations.8. Pump according to claim 1, characterized in that the supply pipe (16) is connected to a plurality of valves (34) mounted in parallel to control the supply of different products, and / or the discharge pipe (18) is connected to a plurality of valves (36) to control the output of the metered product to different destinations.
9. Pompe selon la revendication 1, caractérisée en ce que le capteur de pesage (30) est constitué d'un bloc parallélépipédique de métal partiellement évidé en son centre, et sur la face supérieure et/ou inférieure duquel a été collée une jauge de contrainte, une extrémité étant fixée en un point fixe de la chambre hermétique (10), l'autre extrémité supportant la cuve (20). 9. Pump according to claim 1, characterized in that the weighing sensor (30) consists of a parallelepipedal block of metal partially hollowed out in its center, and on the upper and / or lower face from which a gauge has been stuck. constraint, one end being fixed at a fixed point of the hermetic chamber (10), the other end supporting the tank (20).
PCT/IB1994/000035 1993-03-15 1994-03-10 Pressurisation/partial vacuum pump for delivering predetermined amounts of a product WO1994021924A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU61144/94A AU6114494A (en) 1993-03-15 1994-03-10 Pressurisation/partial vacuum pump for delivering predetermined amounts of a product
EP94907656A EP0689647B1 (en) 1993-03-15 1994-03-10 Pressurisation/partial vacuum pump for delivering predetermined amounts of a product
DE69407274T DE69407274T2 (en) 1993-03-15 1994-03-10 VACUUM AND PRESSURE PUMP FOR DELIVERING SPECIFIC QUANTITIES OF PRODUCTS

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR93/03168 1993-03-15
FR9303168A FR2702802B1 (en) 1993-03-15 1993-03-15 Vacuum and overpressure pump to dispense predetermined quantities of products.

Publications (1)

Publication Number Publication Date
WO1994021924A1 true WO1994021924A1 (en) 1994-09-29

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ID=9445136

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB1994/000035 WO1994021924A1 (en) 1993-03-15 1994-03-10 Pressurisation/partial vacuum pump for delivering predetermined amounts of a product

Country Status (6)

Country Link
EP (1) EP0689647B1 (en)
AT (1) ATE161076T1 (en)
AU (1) AU6114494A (en)
DE (1) DE69407274T2 (en)
FR (1) FR2702802B1 (en)
WO (1) WO1994021924A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0792834A1 (en) * 1996-02-28 1997-09-03 Solvay Interox GmbH Pneumatic conveying and/or metering system for tank installations

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0303376A2 (en) * 1987-08-07 1989-02-15 Innovac Technology Inc. Frail material slurry pump
DE4006558A1 (en) * 1990-03-02 1991-09-05 Josef Woerz Pump system for food fluids - has two intermediate vessels, each connected by separate vacuum and overpressure lines to control valve and form there to pump

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0303376A2 (en) * 1987-08-07 1989-02-15 Innovac Technology Inc. Frail material slurry pump
DE4006558A1 (en) * 1990-03-02 1991-09-05 Josef Woerz Pump system for food fluids - has two intermediate vessels, each connected by separate vacuum and overpressure lines to control valve and form there to pump

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0792834A1 (en) * 1996-02-28 1997-09-03 Solvay Interox GmbH Pneumatic conveying and/or metering system for tank installations

Also Published As

Publication number Publication date
EP0689647B1 (en) 1997-12-10
AU6114494A (en) 1994-10-11
ATE161076T1 (en) 1997-12-15
FR2702802A1 (en) 1994-09-23
DE69407274D1 (en) 1998-01-22
FR2702802B1 (en) 1995-05-12
DE69407274T2 (en) 1998-07-23
EP0689647A1 (en) 1996-01-03

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