Classifications

• • 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
  • F04C11/00—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations
  • F04C11/001—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations of similar working principle
  • F04C11/003—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations of similar working principle having complementary function
• • 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
  • F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
  • F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/06—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
• • 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
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
• • 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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C2/16—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
• • 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
  • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
  • F04C23/001—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle
• • 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
  • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
  • F04C23/005—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of dissimilar working principle
• • 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
  • F04C28/02—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for several pumps connected in series or in parallel
• • 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
  • F04C28/06—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for stopping, starting, idling or no-load operation
• • 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
  • F04C2220/00—Application
  • F04C2220/10—Vacuum
  • F04C2220/12—Dry running

Definitions

• the present invention relates to the field of vacuum techniques. More specifically, it relates to a pumping system comprising a dry screw pump, and a method of pumping by means of this pumping system.
• the rotational speed of the pump plays a very important role, defining the operation of the pump during the different phases succeeding during the emptying of the vacuum chamber.
• the state of the art vacuum pump systems that aim at improving the final vacuum and increasing the flow also includes Roots booster pumps arranged upstream of the main dry pumps.
• This type of system is cumbersome, works either with by-pass valves having reliability problems, or by employing means of measurement, control, adjustment or control.
• these means of control, adjustment or control must be actively controlled, which necessarily results in an increase in the number of components of the system, its complexity and cost.
• the object of the present invention is to enable a better vacuum to be obtained than that (of the order of 0.0001 mbar) that a single screw-type dry vacuum pump can generate in a vacuum chamber.
• Another object of the present invention is to provide a discharge rate which is higher at low pressure than that which can be obtained with the aid of a single screw-type dry vacuum pump during a pumping to make a vacuum in a vacuum chamber.
• the present invention also aims to allow a reduction of the electrical energy required for the emptying of a vacuum chamber and the maintenance of the vacuum, as well as a decrease in the temperature of the outlet gas.
• a pumping system for generating a vacuum comprising a main vacuum pump which is a dry screw pump having a gas inlet suction connected to a vacuum vessel and a gas outlet discharge in a gas discharge conduit to an exhaust outlet of gases out of the pumping system.
• the pumping system further comprises
• a non-return valve positioned between the gas outlet discharge (4) and the exhaust outlet of the gases
• the auxiliary vacuum pump can be dry screw type, pin type, multi-stage Roots, diaphragm type, vane dry type, lubricated vane type.
• the invention also relates to a method of pumping by means of a pumping system as defined above. This process comprises steps in which:
• the main vacuum pump is started in order to pump the gases contained in the vacuum chamber and to discharge these gases by its gas outlet discharge;
• the auxiliary vacuum pump continues to pump all the time that the main vacuum pump pumps the gases contained in the vacuum chamber and / or all the time that the main vacuum pump maintains a defined pressure in the vacuum chamber.
• the auxiliary pump is operated continuously all the time that the vacuum-type main vacuum pump empties the vacuum chamber, but also all the time that the main vacuum pump dries at screw maintains a defined pressure (eg the final vacuum) in the chamber by evacuating gases by its discharge.
• the coupling of the dry-type main vacuum pump and the auxiliary pump can be done without requiring measurements or specific devices (eg pressure sensors, temperature sensors). , current, etc.), servos, data management and calculation. Therefore, the pumping system adapted for the implementation of the pumping method according to the present invention may comprise only a minimal number of components, be very simple and cost considerably less than existing systems.
• the main dry type screw vacuum pump can operate at a single constant speed, that of the electrical network, or rotate at variable speeds according to its own mode of operation. Therefore, the complexity and cost of the pumping system adapted for carrying out the pumping method according to the present invention can be further reduced.
• the auxiliary pump integrated in the pumping system can still operate according to the pumping method according to the invention without being damaged. Its dimensioning is conditioned by a minimum energy consumption for the operation of the device. Its nominal flow rate is chosen according to the volume of the exhaust duct between the dry vacuum master vacuum pump and the non-return valve. This flow rate may advantageously be 1/500 to 1/20 of the nominal flow rate of the dry main screw vacuum pump, but may also be lower or higher than these values, in particular from 1/500 to 11 ⁇ 0 or from 1/500 to 1 / 5u nominal flow rate of the main vacuum pump.
• the non-return valve placed in the duct downstream of the screw-dried main vacuum pump, may be a standard item available commercially. It is dimensioned according to the nominal flow rate of the main dry screw vacuum pump. In particular, it is expected that the check valve closes when the suction pressure of the main vacuum pump dries is between 500 mbar absolute and the final vacuum (eg 100 mbar).
• the auxiliary pump may be of high chemical resistance to the substances and gases commonly used in the semiconductor industry.
• the auxiliary pump is preferably small.
• the auxiliary vacuum pump always pumps in the volume between the gas outlet discharge of the main vacuum pump and the non-return valve.
• the startup of the auxiliary vacuum pump is controlled "all or nothing". Piloting consists of measuring one or more parameters and according to certain rules, starting the auxiliary vacuum pump or stopping it.
• the parameters provided by suitable sensors, are p. ex. the motor current of the main vacuum pump dries screw, the temperature or the pressure of the gases at its discharge, that is to say in the volume upstream of the non-return valve in the discharge pipe, or a combination of these parameters.
• the dimensioning of the auxiliary vacuum pump aims at a minimum energy consumption of its engine. Its nominal flow rate is chosen as a function of the flow rate of the main dry screw vacuum pump, but also taking into account the volume that the gas exhaust duct delimits between the main vacuum pump and the non-return valve. This flow rate can be from 1/500 to 1/20 of the nominal flow rate of the dry, screw-top vacuum pump, but can also be lower or higher than these values.
• the pressure is high, for example equal to the atmospheric pressure. Due to the compression in the dry main vacuum pump, the pressure of the gases discharged at its outlet is higher than the atmospheric pressure (if the gases at the outlet of the main pump are discharged directly to the atmosphere) or higher. than the pressure at the input of another device connected downstream. This causes the non-return valve to open.
• FIG. 1 schematically shows a pumping system adapted for carrying out a pumping method according to a first embodiment of the present invention
• FIG. 2 schematically shows a pumping system adapted for carrying out a pumping method according to a second embodiment of the present invention.
• FIG. 1 represents a pump system SP for generating a vacuum, which is adapted for implementing a pumping method according to a first embodiment of the present invention.
• This pumping system SP comprises an enclosure 1, which is connected to the suction 2 of a main vacuum pump constituted by a dry screw pump 3.
• the output gas discharge of the dry vacuum master vacuum pump 3 is connected to a discharge duct 5.
• a discharge check valve 6 is placed in the discharge duct 5, which after this check valve continues in gas outlet duct 8.
• the non-return valve 6, when it is closed, allows the formation of a volume 4, between the outlet discharge of the gases of the main vacuum pump 3 and itself.
• the pumping system SP also comprises the auxiliary vacuum pump 7, connected in parallel with the non-return valve 6.
• the suction of the auxiliary vacuum pump is connected to the volume 4 of the exhaust pipe 5 and its delivery is connected to the leads 8.
• the auxiliary vacuum pump 7 is started up as well.
• the main screw-dried vacuum pump 3 draws the gases into the chamber 1 via the duct 2 connected to its inlet and compresses them to discharge them thereafter as it leaves the evacuation duct 5 via the non-return valve. 6.
• the closing pressure of the non-return valve 6 is reached, it closes. From this moment the pumping of the auxiliary vacuum pump 7 reduces
• the auxiliary vacuum pump 7 is itself a dry screw pump.
• the main pump and the auxiliary pump can be of the same type, which simplifies operation and handling.
• this combination of pumps makes it possible to use the SP pumping system for all applications where a single screw dry pump can be used.
• the auxiliary vacuum pump 7 is a pin pump, a multi-stage Roots pump, a diaphragm pump, a dry vane pump or a lubricated vane pump. All of these pump combinations have advantages related to the particular properties of each individual type of pump.
• FIG. 2 represents an SPP pumping system adapted for the implementation of a pumping method according to a second embodiment of the present invention.
• the system represented in FIG. 2 represents the controlled pumping system SPP, furthermore comprising suitable sensors 1 1, 12, 13 which control either the motor current (sensor 1 1) of the main dry screw master vacuum pump 3, ie the pressure (gas sensor 13) in the volume of the outlet duct of the screw-dried main vacuum pump, limited by the non-return valve 6, that is the
• auxiliary vacuum pump 7 When these parameters return to initial ranges (out of set points) with a delay, the auxiliary vacuum pump is stopped.
• the auxiliary vacuum pump may be of the dry type with screw, pin, multi-stage Roots, diaphragm, vane or pallet dry lubricated, as in the first embodiment of the invention of FIG.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Reciprocating Pumps (AREA)

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Applications Claiming Priority (1)

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Citations (6)

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• 2014
  • 2014-09-26 CN CN201480082186.8A patent/CN107002680A/zh active Pending
  • 2014-09-26 DK DK14777077.0T patent/DK3198148T3/da active
  • 2014-09-26 KR KR1020177011372A patent/KR20170063839A/ko not_active IP Right Cessation
  • 2014-09-26 WO PCT/EP2014/070691 patent/WO2016045753A1/fr active Application Filing
  • 2014-09-26 PT PT147770770T patent/PT3198148T/pt unknown
  • 2014-09-26 US US15/512,883 patent/US20170298935A1/en not_active Abandoned
  • 2014-09-26 BR BR112017005927-4A patent/BR112017005927B1/pt active IP Right Grant
  • 2014-09-26 JP JP2017516050A patent/JP2017531125A/ja active Pending
  • 2014-09-26 ES ES14777077T patent/ES2780873T3/es active Active
  • 2014-09-26 AU AU2014406724A patent/AU2014406724B2/en active Active
  • 2014-09-26 EP EP14777077.0A patent/EP3198148B1/fr not_active Revoked
  • 2014-09-26 RU RU2017114347A patent/RU2670640C9/ru active
  • 2014-09-26 KR KR1020217025124A patent/KR20210102478A/ko not_active Application Discontinuation
  • 2014-09-26 CA CA2961977A patent/CA2961977A1/fr active Pending
  • 2014-09-26 PL PL14777077T patent/PL3198148T3/pl unknown
• 2015
  • 2015-09-21 TW TW104131132A patent/TWI725943B/zh active

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