EP0537051B1 - Installation for the pumping of gas with pumping speed regulation - Google Patents

Installation for the pumping of gas with pumping speed regulation Download PDF

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Publication number
EP0537051B1
EP0537051B1 EP92402669A EP92402669A EP0537051B1 EP 0537051 B1 EP0537051 B1 EP 0537051B1 EP 92402669 A EP92402669 A EP 92402669A EP 92402669 A EP92402669 A EP 92402669A EP 0537051 B1 EP0537051 B1 EP 0537051B1
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EP
European Patent Office
Prior art keywords
bellows
roots
machine
inlet portion
gas
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Expired - Lifetime
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EP92402669A
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German (de)
French (fr)
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EP0537051A1 (en
Inventor
Jean-Marc Paquet
Luc Mathieu
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Alcatel CIT SA
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Alcatel CIT SA
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
    • F04B37/14—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use to obtain high vacuum
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B41/00—Pumping installations or systems specially adapted for elastic fluids
    • F04B41/06—Combinations of two or more pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/22—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves
    • F04B49/225—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves with throttling valves or valves varying the pump inlet opening or the outlet opening

Definitions

  • the present invention relates to a gas pumping installation comprising the series connection of a machine of the ROOTS type and of a primary pump, a suction inlet part of the ROOTS machine being connected to an enclosure to be emptied.
  • ROOTS type machines as they are currently used, are limited in terms of their flow rate in the high pressure range, in particular due to their coupling with a primary pump, the flow rate of which is lower at high suction pressures. , as well as the limited power of their engine.
  • document EP-A-343 914 discloses a gas pumping installation comprising the series mounting of a machine of the ROOTS type and of a primary pump, a suction inlet part of the machine.
  • ROOTS being connected to an enclosure to be emptied, the installation comprising a regulation device as a function of the difference between the pressures prevailing, respectively, in said inlet part, and a discharge outlet part of the ROOTS machine, so to adapt the flow of the ROOTS machine to that of the primary pump.
  • the regulating device includes a "bypass" pipe as well as pressure sensors upstream and downstream of the ROOTS pump.
  • the present invention aims to provide an installation of the type as above, but avoiding the use of a "bypass" pipe and therefore less bulky, simpler and economical and requiring no control.
  • the invention is thus characterized in that said regulating device consists of a device for regulating the gas passage section of said suction inlet part of the ROOTS machine.
  • the regulating device preferably comprises a bellows of generally elongated shape, arranged transversely with respect to the flow of gas in the inlet part of the ROOTS machine, the cross section of this bellows being substantially equal to or greater than the inner section of said inlet part, a first end of the bellows being fixed in a sealed manner in a wall of said inlet part, the second end of the bellows being closed and movable in the longitudinal direction of the bellows so as to modify the gas passage section.
  • This second end is subjected, on its outer side, to the pressure prevailing in the inlet part of the ROOTS machine and, on its inner side, directly or by means of a mechanical member, through an opening in the wall supporting said first end and through a channel connecting this opening to the discharge outlet part of the ROOTS machine, at the pressure prevailing in this outlet part.
  • a spring such as a helical tension spring, can be arranged to act on said movable end of the bellows, so as to compensate for the stiffness of the latter and to maintain it in an equilibrium position, when said pressure difference is substantially zero.
  • the bellows used preferably has a generally cylindrical shape and has a diameter greater than the largest dimension of the internal section of the inlet part of the ROOTS machine, said bellows being disposed in a transverse cylindrical housing formed in said part. inlet, so that the bellows is guided during its deformation and allows the passage of gas only through the space between the walls of said housing and the external surface of the bellows.
  • the mechanical member transmitting the pressure through said wall of the entry part of the ROOTS machine can be a rod, one end of which is fixed to the movable end of the bellows and which passes through said opening of the wall of said part. entry.
  • the ROOTS machine shown diagrammatically in FIG. 1 comprises an inlet part, designated as a whole by the reference 1, and an outlet part designated by 2, between which is disposed a pumping structure 3 with rotary pistons 4, 5.
  • the opening 6 of the part d he input of the machine is intended to be put in communication with an enclosure to be emptied.
  • the discharge outlet 7 of the ROOTS machine is connected to a primary pump indicated diagrammatically by a block 8.
  • a bellows 9 of generally cylindrical shape is arranged transversely in the inlet part 1 of the ROOTS machine.
  • One end 10 of this bellows is tightly fixed in the wall of this inlet part, the other end 11 being able to engage in the position of maximum elongation of the bellows in a hollow portion 12 of the wall of said input portion.
  • the bellows In the retracted position of the bellows, shown in FIG. 2, the bellows is folded back into a hollow part 13 of the wall diametrically opposite to the part 12.
  • FIG. 3 shows that the entry part of the machine forms an essentially cylindrical housing 14, in which the bellows is guided during its movement.
  • the diameter of this housing is slightly larger than the outside diameter of the bellows, and appreciably larger than the diameter of the inlet opening 6, so that in the position of maximum extension of the bellows, the sucked gas can only pass between the space between the external surface of the bellows and the surface of the housing 14 as well as, if necessary, in the space between the parts 11 and 12.
  • the bellows is provided with an actuating rod 20 passing through a fixing portion 15 to enter a chamber 16, which is connected by a channel 17 to the volume 18 of the outlet portion of machine discharge.
  • the bellows 9 is thus subjected to the difference between the pressures prevailing, respectively, in the inlet part and in the outlet part of the ROOTS machine.
  • a helical tension spring 19 can be provided inside the bellows 9 to compensate for the stiffness of the latter, and to maintain it in an equilibrium position when said pressure difference is substantially zero.
  • the ROOTS machine and the primary pump start to operate simultaneously and the bellows is opened according to the position in Fig. 2. Since the flow rate of the ROOTS machine is higher than that of the primary pump, the pressure in the chamber 18 and, consequently, in the chamber 16, becomes higher than the pressure in the inlet part of the machine , and the bellows closes. Consequently, the flow rate of the ROOTS machine decreases and the position of the bellows stabilizes when the flow rate of the ROOTS machine is compatible with that of the primary pump, the bellows being ajar to allow only the quantity of gas corresponding to this regime to pass. stable.
  • the stiffness of the helical spring is chosen so as to compensate and preferably be slightly greater than that of the bellows itself, so that at rest the bellows returns to the position shown in FIG. 2.
  • the regulation device which has just been described is particularly simple and does not require any additional monitoring or actuation device.
  • the channel 17 serving only to put the chamber 18 and the chamber 16 in communication, and therefore having no gas flow rate, its section can be relatively small, which saves space in the ROOTS machine compared to a bypass machine with the same pumping rate.
  • the calibration of the stiffness and the preload of the spring 19 makes it possible to adapt the flow rate of the ROOTS machine to the maximum flow rate of the primary pump.
  • a particular advantage lies in the fact that the closure of the inlet part is never complete and the operation of the ROOTS machine is not interrupted, so that the passage of gas between the grooves of the bellows makes it possible to avoid deposits and sticking of solid particles contained in the gas. Furthermore, it appears from the above that there is no gas recycling from the chamber 18 to the inlet part of the ROOTS device, which makes it possible to avoid pollution of the enclosure to be emptied.
  • the bellows is only subject to low pressure corrosion which is relatively mild. In the event of a bellows failure, the installation as a whole remains watertight, so that the pumped gases present no risk to the operator.
  • the present invention thus achieves considerable advantages over the usual installations of the type mentioned at the start.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Reciprocating Pumps (AREA)
  • Gas Separation By Absorption (AREA)
  • Control Of The Air-Fuel Ratio Of Carburetors (AREA)

Abstract

A machine of the ROOTS type is connected, via a suction inlet part (1), to an enclosure to be evacuated and, by a delivery outlet part (2), to a primary pump (8). A bellows (9) is located transversely in the intake part (1), one (10) of its ends being fixed, in a sealed fashion, into the wall, and the other end (11) being closed and capable of moving, so that the bellows (9) forms a member for regulating the passage cross-section of the gas in the intake part (1). The movable end (11) of the bellows is subjected, on its outer side, to the pressure prevailing in the intake part (1) and, on its inner side, by means of a rod (20) passing through the wall, and through a passageway (17) to the pressure prevailing in the delivery outlet part (2). <??>The invention applies to machines of the ROOTS type, especially for automatically regulating the pumping speed to match the latter to the flow rate of the corresponding primary pump. <IMAGE>

Description

La présente invention concerne une installation de pompage de gaz comprenant le montage en série d'une machine du type ROOTS et d'une pompe primaire, une partie d'entrée d'aspiration de la machine ROOTS étant connectée à une enceinte à vider.The present invention relates to a gas pumping installation comprising the series connection of a machine of the ROOTS type and of a primary pump, a suction inlet part of the ROOTS machine being connected to an enclosure to be emptied.

Les machines du type ROOTS, telles qu'elles sont employées actuellement sont limitées quant à leur débit dans le domaine des hautes pressions, notamment du fait de leur couplage avec une pompe primaire, dont le débit est plus faible à de hautes pressions d'aspiration, ainsi que du fait de la puissance limitée de leur moteur.ROOTS type machines, as they are currently used, are limited in terms of their flow rate in the high pressure range, in particular due to their coupling with a primary pump, the flow rate of which is lower at high suction pressures. , as well as the limited power of their engine.

On a déjà proposé l'utilisation de systèmes de démarrage asservis à la pression de travail de la pompe primaire et à la différence de pression entre les parties d'aspiration et de refoulement de la machine ROOTS. De tels dispositifs sont coûteux et compliqués et, par conséquent, peu fiables. D'autre part, les systèmes asservis nécessitant une prise de pression dans la ligne de pompage, présentent des inconvénients majeurs, notamment pour des raisons de sécurité dans le cas du pompage de gaz corrosifs.We have already proposed the use of starting systems controlled by the working pressure of the primary pump and the pressure difference between the suction and delivery parts of the ROOTS machine. Such devices are expensive and complicated and therefore unreliable. On the other hand, slave systems requiring a pressure tap in the pumping line have major drawbacks, in particular for safety reasons in the case of pumping corrosive gases.

Par exemple, on connaît par le document EP-A-343 914 une installation de pompage de gaz comprenant le montage en série d'une machine du type ROOTS et d'une pompe primaire, une partie d'entrée d'aspiration de la machine ROOTS étant connectée à une enceinte à vider, l'installation comportant un dispositif de régulation en fonction de la différence entre les pressions régnant, respectivement, dans ladite partie d'entrée, et une partie de sortie de refoulement de la machine ROOTS, de façon à adapter le débit de la machine ROOTS à celui de la pompe primaire.For example, document EP-A-343 914 discloses a gas pumping installation comprising the series mounting of a machine of the ROOTS type and of a primary pump, a suction inlet part of the machine. ROOTS being connected to an enclosure to be emptied, the installation comprising a regulation device as a function of the difference between the pressures prevailing, respectively, in said inlet part, and a discharge outlet part of the ROOTS machine, so to adapt the flow of the ROOTS machine to that of the primary pump.

Cependant, dans cette installation, le dispositif de régulation comporte une conduite de "by pass" ainsi que des capteurs de pression en amont et en aval de la pompe ROOTS.However, in this installation, the regulating device includes a "bypass" pipe as well as pressure sensors upstream and downstream of the ROOTS pump.

La présente invention a pour but de proposer une installation du type tel que ci-dessus, mais évitant l'utilisation d'une conduite de "by pass" et donc moins encombrant, plus simple et économique et ne nécessitant aucune commande.The present invention aims to provide an installation of the type as above, but avoiding the use of a "bypass" pipe and therefore less bulky, simpler and economical and requiring no control.

L'invention est ainsi caractérisée en ce que ledit dispositif de régulation consiste en un dispositif de régulation de la section de passage du gaz de ladite partie d'entrée d'aspiration de la machine ROOTS.The invention is thus characterized in that said regulating device consists of a device for regulating the gas passage section of said suction inlet part of the ROOTS machine.

Plus particulièrement, le dispositif de régulation comporte, de préférence, un soufflet de forme générale allongée, disposé transversalement par rapport au flux du gaz dans la partie d'entrée de la machine ROOTS, la section transversale de ce soufflet étant sensiblement égale ou supérieure à la section intérieure de ladite partie d'entrée, une première extrémité du soufflet étant fixée, de façon étanche, dans une paroi de ladite partie d'entrée, la seconde extrémité du soufflet étant fermée et déplaçable dans le sens longitudinal du soufflet de manière à modifier la section de passage du gaz. Cette seconde extrémité est soumise, sur son côté extérieur, à la pression régnant dans la partie d'entrée de la machine ROOTS et, sur son côté intérieur, directement ou par l'intermédiaire d'un organe mécanique, à travers une ouverture dans la paroi supportant ladite première extrémité et à travers un canal reliant cette ouverture à la partie de sortie de refoulement de la machine ROOTS, à la pression régnant dans cette partie de sortie. Un ressort, tel qu'un ressort hélicoïdal de traction, peut être agencé pour agir sur ladite extrémité déplaçable du soufflet, de manière à compenser la raideur de celui-ci et à le maintenir dans une position d'équilibre, lorsque ladite différence de pression est sensiblement nulle.More particularly, the regulating device preferably comprises a bellows of generally elongated shape, arranged transversely with respect to the flow of gas in the inlet part of the ROOTS machine, the cross section of this bellows being substantially equal to or greater than the inner section of said inlet part, a first end of the bellows being fixed in a sealed manner in a wall of said inlet part, the second end of the bellows being closed and movable in the longitudinal direction of the bellows so as to modify the gas passage section. This second end is subjected, on its outer side, to the pressure prevailing in the inlet part of the ROOTS machine and, on its inner side, directly or by means of a mechanical member, through an opening in the wall supporting said first end and through a channel connecting this opening to the discharge outlet part of the ROOTS machine, at the pressure prevailing in this outlet part. A spring, such as a helical tension spring, can be arranged to act on said movable end of the bellows, so as to compensate for the stiffness of the latter and to maintain it in an equilibrium position, when said pressure difference is substantially zero.

Le soufflet utilisé a, de préférence, une forme générale cylindrique et possède un diamètre supérieur à la plus grande dimension de la section intérieure de la partie d'entrée de la machine ROOTS, ledit soufflet étant disposé dans un logement cylindrique transversal formé dans ladite partie d'entrée, de façon que le soufflet soit guidé lors de sa déformation et ne permette le passage du gaz qu'à travers l'espace entre les parois dudit logement et la surface extérieure du soufflet. L'organe mécanique transmettant la pression à travers ladite paroi de la partie d'entrée de la machine ROOTS, peut être une tige, dont une extrémité est fixée à l'extrémité déplaçable du soufflet et qui traverse ladite ouverture de la paroi de ladite partie d'entrée.The bellows used preferably has a generally cylindrical shape and has a diameter greater than the largest dimension of the internal section of the inlet part of the ROOTS machine, said bellows being disposed in a transverse cylindrical housing formed in said part. inlet, so that the bellows is guided during its deformation and allows the passage of gas only through the space between the walls of said housing and the external surface of the bellows. The mechanical member transmitting the pressure through said wall of the entry part of the ROOTS machine, can be a rod, one end of which is fixed to the movable end of the bellows and which passes through said opening of the wall of said part. entry.

L'invention sera mieux comprise à la lumière de la description d'une forme d'exécution particulière donnée à titre d'exemple et illustrée dans le dessin annexe, dans lequel:

  • La Fig. 1 est une représentation schématique, en coupe longitudinale, d'une machine ROOTS, comportant un dispositif de régulation de la section de passage du gaz dans sa partie d'entrée.
  • La Fig. 2 est une vue en coupe axiale de la partie d'entrée de la machine ROOTS, montrant la position ouverte du dispositif de régulation, et
  • La Fig. 3 est une coupe selon le plan III-III de la Fig. 2.
The invention will be better understood in the light of the description of a particular embodiment given by way of example and illustrated in the accompanying drawing, in which:
  • Fig. 1 is a schematic representation, in longitudinal section, of a ROOTS machine, comprising a device for regulating the cross section of the gas in its inlet part.
  • Fig. 2 is a view in axial section of the entry part of the ROOTS machine, showing the open position of the regulating device, and
  • Fig. 3 is a section along the plane III-III of FIG. 2.

La machine ROOTS représentée schématiquement à la Fig. 1 comporte une partie d'entrée, désignée dans son ensemble par la référence 1, et une partie de sortie désignée par 2, entre lesquelles est disposée une structure de pompage 3 à pistons rotatifs 4, 5. L'ouverture 6 de la partie d'entrée de la machine est destinée à être mise en communication avec une enceinte à vider. L'orifice de sortie de refoulement 7 de la machine ROOTS est connecté à une pompe primaire indiquée schématiquement par un bloc 8.The ROOTS machine shown diagrammatically in FIG. 1 comprises an inlet part, designated as a whole by the reference 1, and an outlet part designated by 2, between which is disposed a pumping structure 3 with rotary pistons 4, 5. The opening 6 of the part d he input of the machine is intended to be put in communication with an enclosure to be emptied. The discharge outlet 7 of the ROOTS machine is connected to a primary pump indicated diagrammatically by a block 8.

Un soufflet 9 de forme générale cylindrique est disposé transversalement dans la partie d'entrée 1 de la machine ROOTS. Une extrémité 10 de ce soufflet est fixée, de façon étanche, dans la paroi de cette partie d'entrée, l'autre extrémité 11 pouvant s'engager dans la position d'allongement maximale du soufflet dans une portion creuse 12 de la paroi de ladite partie d'entrée. Dans la position rétractée du soufflet, montrée à la Fig. 2, le soufflet est replié dans une partie creuse 13 de la paroi diamètralement opposée à la partie 12.A bellows 9 of generally cylindrical shape is arranged transversely in the inlet part 1 of the ROOTS machine. One end 10 of this bellows is tightly fixed in the wall of this inlet part, the other end 11 being able to engage in the position of maximum elongation of the bellows in a hollow portion 12 of the wall of said input portion. In the retracted position of the bellows, shown in FIG. 2, the bellows is folded back into a hollow part 13 of the wall diametrically opposite to the part 12.

La section transversale de la Fig. 3 montre que la partie d'entrée de la machine forme un logement essentiellement cylindrique 14, dans lequel le soufflet est guidé lors de son déplacement. Le diamètre de ce logement est légèrement plus grand que le diamètre extérieur du soufflet, et sensiblement plus grand que le diamètre de l'ouverture d'entrée 6, de sorte que dans la position d'allongement maximale du soufflet, le gaz aspiré ne peut passer qu'entre l'espace compris entre la surface extérieure du soufflet et la surface du logement 14 ainsi que, le cas échéant, dans l'espace entre les parties 11 et 12.The cross section of FIG. 3 shows that the entry part of the machine forms an essentially cylindrical housing 14, in which the bellows is guided during its movement. The diameter of this housing is slightly larger than the outside diameter of the bellows, and appreciably larger than the diameter of the inlet opening 6, so that in the position of maximum extension of the bellows, the sucked gas can only pass between the space between the external surface of the bellows and the surface of the housing 14 as well as, if necessary, in the space between the parts 11 and 12.

Comme le montrent les Figures 1 et 2, le soufflet est muni d'une tige d'actionnement 20 traversant une partie de fixation 15 pour pénétrer dans une chambre 16, qui est reliée par un canal 17 au volume 18 de la partie de sortie de refoulement de la machine. Le soufflet 9 est ainsi soumis à la différence entre les pressions régnant, respectivement, dans la partie d'entrée et dans la partie de sortie de la machine ROOTS. Un ressort hélicoïdal de traction 19 peut être prévu à l'intérieur du soufflet 9 pour compenser la raideur de ce dernier, et pour le maintenir dans une position d'équilibre lorsque ladite différence de pression est sensiblement nulle.As shown in Figures 1 and 2, the bellows is provided with an actuating rod 20 passing through a fixing portion 15 to enter a chamber 16, which is connected by a channel 17 to the volume 18 of the outlet portion of machine discharge. The bellows 9 is thus subjected to the difference between the pressures prevailing, respectively, in the inlet part and in the outlet part of the ROOTS machine. A helical tension spring 19 can be provided inside the bellows 9 to compensate for the stiffness of the latter, and to maintain it in an equilibrium position when said pressure difference is substantially zero.

Le fonctionnement de l'installation décrite est le suivant.The operation of the installation described is as follows.

Lors du démarrage de l'installation, la machine ROOTS et la pompe primaire commencent à fonctionner simultanément et le soufflet est ouvert selon la position de la Fig. 2. Etant donné que le débit de la machine ROOTS est supérieur à celui de la pompe primaire, la pression dans la chambre 18 et, par conséquent, dans la chambre 16, devient supérieure à la pression dans la partie d'entrée de la machine, et le soufflet se ferme. Par conséquent, le débit de la machine ROOTS diminue et la position du soufflet se stabilise lorsque le débit de la machine ROOTS est compatible avec celui de la pompe primaire, le soufflet étant entrouvert pour ne laisser passer que la quantité de gaz correspondant à ce régime stable.When the installation starts, the ROOTS machine and the primary pump start to operate simultaneously and the bellows is opened according to the position in Fig. 2. Since the flow rate of the ROOTS machine is higher than that of the primary pump, the pressure in the chamber 18 and, consequently, in the chamber 16, becomes higher than the pressure in the inlet part of the machine , and the bellows closes. Consequently, the flow rate of the ROOTS machine decreases and the position of the bellows stabilizes when the flow rate of the ROOTS machine is compatible with that of the primary pump, the bellows being ajar to allow only the quantity of gas corresponding to this regime to pass. stable.

En cas de variation brutale de la pression de gaz à l'entrée de la machine ROOTS, par suite d'une introduction de gaz dans l'enceinte, la pression dans la chambre 18 croît rapidement du fait du débit supérieur de la machine ROOTS par rapport à celui de la pompe primaire. Par conséquent le soufflet s'allonge, le cas échéant jusqu'à sa position extrême dans laquelle le gaz ne passera qu'autour du soufflet dans les cannelures de celui-ci. L'abaissement de la pression à l'entrée de la machine ROOTS permet de revenir aux conditions de fonctionnement stables décrites précédemment.In the event of a sudden change in the gas pressure at the inlet of the ROOTS machine, as a result of the introduction of gas into the enclosure, the pressure in the chamber 18 increases rapidly due to the higher flow rate of the ROOTS machine by compared to that of the pump primary. Consequently, the bellows lengthens, if necessary up to its extreme position in which the gas will only pass around the bellows in the grooves thereof. The lowering of the pressure at the inlet of the ROOTS machine makes it possible to return to the stable operating conditions described above.

La raideur du ressort hélicoïdal est choisie de façon à compenser et à être de préférence légèrement supérieure à celle du soufflet lui-même, de sorte qu'au repos le soufflet revienne dans la position montrée à la Fig. 2.The stiffness of the helical spring is chosen so as to compensate and preferably be slightly greater than that of the bellows itself, so that at rest the bellows returns to the position shown in FIG. 2.

Le dispositif de régulation qui vient d'être décrit est particulièrement simple et ne nécessite aucun dispositif supplémentaire de surveillance ou d'actionnement. Le canal 17 ne servant qu'à mettre en communication la chambre 18 et la chambre 16, et ne présentant donc pas de débit de gaz, sa section peut être relativement faible, ce qui permet un gain en encombrement de la machine ROOTS par rapport à une machine à by-pass de même débit de pompage. Le tarage de la raideur et de la précontrainte du ressort 19 permet d'adapter le débit de la machine ROOTS au débit maximal de la pompe primaire.The regulation device which has just been described is particularly simple and does not require any additional monitoring or actuation device. The channel 17 serving only to put the chamber 18 and the chamber 16 in communication, and therefore having no gas flow rate, its section can be relatively small, which saves space in the ROOTS machine compared to a bypass machine with the same pumping rate. The calibration of the stiffness and the preload of the spring 19 makes it possible to adapt the flow rate of the ROOTS machine to the maximum flow rate of the primary pump.

Un avantage particulier réside dans le fait que l'obturation de la partie d'entrée n'est jamais complète et le fonctionnement de la machine ROOTS n'est pas interrompu, de sorte que le passage du gaz entre les cannelures du soufflet permet d'éviter les dépôts et collages de particules solides contenues dans le gaz. Par ailleurs, il ressort de ce qui précède qu'il n'y a pas de recyclage de gaz depuis la chambre 18 vers la partie d'entrée du dispositif ROOTS, ce qui permet d'éviter la pollution de l'enceinte à vider. En cas de pompage de produits corrosifs, le soufflet n'est soumis qu'à de la corrosion à basse pression qui est relativement peu agressive. En cas de bris de soufflet, l'installation, dans son ensemble, reste étanche, de sorte que les gaz pompés présentent pas de risques pour l'opérateur.A particular advantage lies in the fact that the closure of the inlet part is never complete and the operation of the ROOTS machine is not interrupted, so that the passage of gas between the grooves of the bellows makes it possible to avoid deposits and sticking of solid particles contained in the gas. Furthermore, it appears from the above that there is no gas recycling from the chamber 18 to the inlet part of the ROOTS device, which makes it possible to avoid pollution of the enclosure to be emptied. When pumping corrosive products, the bellows is only subject to low pressure corrosion which is relatively mild. In the event of a bellows failure, the installation as a whole remains watertight, so that the pumped gases present no risk to the operator.

La présente invention réalise ainsi des avantages considérables par rapport aux installations usuelles du type mentionné au début.The present invention thus achieves considerable advantages over the usual installations of the type mentioned at the start.

Claims (6)

  1. A gas pumping installation comprising a Roots-type machine and a primary pump connected in series, a suction inlet portion (1) of the Roots machine being connected to an enclosure to be evacuated, the installation including a regulating device for regulating the gas-flow sectional area as a function of the pressure difference between the respective pressures in said inlet portion and in a delivery outlet portion (2) of the Roots machine, so as to match the flow-rate of the Roots machine to that of the primary pump, the installation being characterized in that said regulating device consists of a regulating device for regulating the gas-flow sectional area of said suction inlet portion (1) of the Roots machine.
  2. An installation according to claim 1, characterized in that the regulating device includes a bellows (9) of elongate overall shape and disposed transversely relative to the flow of gas in the inlet portion (1) of the Roots machine, the cross-sectional area of the bellows being substantially not less than the inside sectional area of said inlet portion, a first end (10) of the bellows being fixed in gastight manner in a wall of said inlet portion, the second end (11) of the bellows being closed and movable in the longitudinal direction of the bellows so as to change the gas-flow sectional area, the outside face of the second end being subjected to the pressure in the inlet portion (1) of the Roots machine, and the inside face of the second end being subjected to the pressure in the outlet portion, either directly or via a mechanical member, via an opening in the wall supporting said first end and via a channel (17) connecting the opening to the delivery outlet portion (2) of the Roots machine.
  3. An installation according to claim 2, characterized in that a spring (19) is provided to act on said movable end (11) of the bellows (9), so as to compensate for the stiffness thereof and so as to maintain it in a position of equilibrium when said pressure difference is substantially zero.
  4. An installation according to claim 3, characterized in that said spring (19) is a helical traction spring.
  5. An installation according to claim 2, characterized in that said bellows (9) is cylindrical in overall shape and has a diameter larger than the largest dimension of the inside sectional area of the inlet portion (1) of the Roots machine, said bellows (9) being disposed in a transverse cylindrical housing (14) formed in said inlet portion, so that the bellows (9) is guided when it is being deformed and allows gas to flow only through the space between the walls of said housing and the outside surface of the bellows.
  6. An installation according to claim 2, characterized in that said mechanical member is a rod (20) which has one of its ends fixed to the movable end of the bellows, and which passes through said opening in the wall of the inlet portion of the Roots machine.
EP92402669A 1991-10-07 1992-09-29 Installation for the pumping of gas with pumping speed regulation Expired - Lifetime EP0537051B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9112310A FR2682164B1 (en) 1991-10-07 1991-10-07 GAS PUMPING INSTALLATION WITH PUMPING SPEED REGULATION.
FR9112310 1991-10-07

Publications (2)

Publication Number Publication Date
EP0537051A1 EP0537051A1 (en) 1993-04-14
EP0537051B1 true EP0537051B1 (en) 1994-12-07

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EP92402669A Expired - Lifetime EP0537051B1 (en) 1991-10-07 1992-09-29 Installation for the pumping of gas with pumping speed regulation

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US (1) US5244353A (en)
EP (1) EP0537051B1 (en)
JP (1) JP3251983B2 (en)
AT (1) ATE115242T1 (en)
DE (1) DE69200828T2 (en)
DK (1) DK0537051T3 (en)
FR (1) FR2682164B1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030236489A1 (en) 2002-06-21 2003-12-25 Baxter International, Inc. Method and apparatus for closed-loop flow control system
FR2971018A1 (en) * 2011-01-27 2012-08-03 Alcatel Vacuum Technology France Primary vacuum pump for load-lock chamber to load and unload photovoltaic substrates used to manufacture e.g. flat screens, has variation unit increasing space without entering/leaving of gas when pump is in limited vacuum operation state
CN102155386A (en) * 2011-05-27 2011-08-17 开平太平洋绝缘材料有限公司 Liquid ring type vacuum pump
GB2508396B (en) 2012-11-30 2015-10-07 Edwards Ltd Improvements in and relating to vacuum conduits
CN107250558B (en) 2015-02-23 2019-12-20 豪顿罗茨有限责任公司 Device for regulating the flow of a working fluid
US11815095B2 (en) * 2019-01-10 2023-11-14 Elival Co., Ltd Power saving vacuuming pump system based on complete-bearing-sealing and dry-large-pressure-difference root vacuuming root pumps

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1948907A (en) * 1931-04-18 1934-02-27 Egli Eugen Compressor
US2951633A (en) * 1955-07-14 1960-09-06 Wagner Electric Corp System and method of lubricating air compressors and the like
US2935242A (en) * 1955-07-23 1960-05-03 Heraeus Gmbh W C Pumping apparatus
CH470589A (en) * 1968-10-11 1969-03-31 Balzers Patent Beteilig Ag Arrangement for evacuating recipients
US3680980A (en) * 1970-02-20 1972-08-01 Hans U Bart Fuel pump
US3922110A (en) * 1974-01-28 1975-11-25 Henry Huse Multi-stage vacuum pump
US4596518A (en) * 1984-02-03 1986-06-24 Diesel Kiki Co., Ltd. Swash-plate type compressor
JPS60171989U (en) * 1984-04-25 1985-11-14 株式会社ボッシュオートモーティブ　システム Vane type compressor for car cooler
US4563134A (en) * 1985-06-24 1986-01-07 General Motors Corporation Cylinder head with pressure regulator valve
JPS63263282A (en) * 1987-04-22 1988-10-31 Toyota Autom Loom Works Ltd Capacity control mechanism for car air-conditioner compressor
US4850806A (en) * 1988-05-24 1989-07-25 The Boc Group, Inc. Controlled by-pass for a booster pump

Also Published As

Publication number Publication date
DE69200828T2 (en) 1995-04-13
FR2682164B1 (en) 1995-01-20
US5244353A (en) 1993-09-14
EP0537051A1 (en) 1993-04-14
DE69200828D1 (en) 1995-01-19
JP3251983B2 (en) 2002-01-28
ATE115242T1 (en) 1994-12-15
FR2682164A1 (en) 1993-04-09
DK0537051T3 (en) 1995-03-06
JPH05231371A (en) 1993-09-07

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