Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/10—Mixing gases with gases
  • B01F23/19—Mixing systems, i.e. flow charts or diagrams; Arrangements, e.g. comprising controlling means
  • B01F23/191—Mixing systems, i.e. flow charts or diagrams; Arrangements, e.g. comprising controlling means characterised by the construction of the controlling means
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D11/00—Control of flow ratio
  • G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
  • G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
  • G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
  • G05D11/132—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components by controlling the flow of the individual components
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/20—Measuring; Control or regulation
  • B01F35/21—Measuring
  • B01F35/211—Measuring of the operational parameters
  • B01F35/2111—Flow rate
  • B01F35/21111—Mass flow rate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/20—Measuring; Control or regulation
  • B01F35/22—Control or regulation
  • B01F35/221—Control or regulation of operational parameters, e.g. level of material in the mixer, temperature or pressure
  • B01F35/2211—Amount of delivered fluid during a period
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/20—Measuring; Control or regulation
  • B01F35/22—Control or regulation
  • B01F35/221—Control or regulation of operational parameters, e.g. level of material in the mixer, temperature or pressure
  • B01F35/2218—Weight of at least one component to be mixed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
  • B01F35/71805—Feed mechanisms characterised by the means for feeding the components to the mixer using valves, gates, orifices or openings
  • B01F35/718051—Feed mechanisms characterised by the means for feeding the components to the mixer using valves, gates, orifices or openings being adjustable
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C5/00—Methods or apparatus for filling containers with liquefied, solidified, or compressed gases under pressures
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D7/00—Control of flow
  • G05D7/06—Control of flow characterised by the use of electric means
  • G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
  • G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
  • G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
  • G05D7/0641—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means using a plurality of throttling means
  • G05D7/0652—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means using a plurality of throttling means the plurality of throttling means being arranged in parallel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2221/00—Handled fluid, in particular type of fluid
  • F17C2221/03—Mixtures
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
  • F17C2250/03—Control means
  • F17C2250/032—Control means using computers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2260/00—Purposes of gas storage and gas handling
  • F17C2260/02—Improving properties related to fluid or fluid transfer
  • F17C2260/025—Reducing transfer time
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2265/00—Effects achieved by gas storage or gas handling
  • F17C2265/02—Mixing fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
  • F17C2270/00—Applications
  • F17C2270/01—Applications for fluid transport or storage

Definitions

• the present invention relates to an installation for preparing and packaging a gas mixture intended to be packaged in at least one fluid container.
• the invention also relates to a mixture conditioning method implementing such an installation.
• an installation and a method according to the invention are intended to condition a mixture comprising one or more minority gases such as carbon dioxide, carbon monoxide, nitrogen dioxide, nitrogen monoxide, oxygen , hydrogen, hydrocarbons such as methane or propane, and comprising a carrier gas, in particular nitrogen, argon, helium.
• one or more minority gases such as carbon dioxide, carbon monoxide, nitrogen dioxide, nitrogen monoxide, oxygen , hydrogen, hydrocarbons such as methane or propane, and comprising a carrier gas, in particular nitrogen, argon, helium.
• the invention can be applied in particular to the preparation and packaging of calibration gas mixtures used for the calibration and/or adjustment of gas analysis or detection equipment.
• the invention can also be applied to the conditioning of gas mixtures used in the field of electronics, in particular in the process of manufacturing integrated circuits and the production of semiconductors.
• gas mixtures are packaged in compressed form in containers, in particular cylinders.
• a gas cylinder is filled in sequential mode, the constituents of the mixture being introduced one after the other into the cylinder, starting with the constituent with the lowest content.
• a control of the quantity of gas introduced into the bottle is carried out, either by monitoring the pressure in the bottle during and after the introduction of the constituent, or by weighing the bottle during the introduction of the constituent.
• Such an installation for conditioning gas mixtures is described in particular in document WO2010/031940A1.
• the maximum variation tolerance of the actual values of the concentrations with respect to the target values can be 1% (relative %) or even 0.7% or even less. Such tolerances are all the more difficult to respect when the number of constituents is large and/or when their contents are low.
• manometric conditioning by pressure control offers an accuracy that is intrinsically limited by the accuracy of the pressure sensor and by the temperature variations which influence the calculation of the quantity of gas. Added to the uncertainty of the concentration values of the gas mixture produced are the differences in concentration between the mixtures packaged in different cylinders.
• Gravimetric packaging by weighing the constituents offers greater precision on the composition of the mixture but still imposes sequential filling of the bottles. After the introduction of each constituent, a waiting time is necessary to stabilize the measurement conditions before controlling the quantity of gas introduced. In addition, a final stage of homogenization of the mixture is necessary, for example by setting the bottle in motion using a bottle roller.
• Another disadvantage of current packaging methods is their limited efficiency, typically at a daily rate of 8 to 10 bottles per filling station. Furthermore, the bottles are filled one by one, which requires disconnection and reconnection operations each time the bottle is changed. Finally, the choice of the composition of the mixture is limited by the constituents present on the filling station, which leaves little freedom in the range of mixtures that can be manufactured.
• the object of the invention is to overcome all or part of the drawbacks mentioned above, in particular by proposing an installation for conditioning a mixture of gases offering more precision, reproducibility and flexibility in the composition of the mixture, as well as faster and more efficient filling of fluid containers.
• the invention may include one or more of the characteristics set out below.
• the first transfer circuit and the second transfer circuit each comprise an expansion member.
• Such an expansion member makes it possible to perform the mixing at low pressure, which makes it possible to use more precise regulating members. This therefore makes it possible to significantly improve the precision of the mixture.
• the flowmeter comprises a mass flowmeter and the regulating member comprises a valve, in particular a piezoelectric valve.
• Such a piezoelectric valve makes it possible, in combination with the expansion member and the pressure-raising member, to significantly improve the precision of the mixture.
• At least two of the regulating members are configured to regulate the flow of minority gas over respective flow ranges having distinct minimum flow values and/or distinct maximum flow values.
• All of the regulating members are configured to regulate the flow of minority gas over respective flow ranges having distinct minimum flow values and/or distinct maximum flow values.
• the second transfer circuit is devoid of any flow regulating device to regulate the flow of the carrier gas flowing towards the mixing device.
• the control unit is configured to select a regulator member for which the first flow rate setpoint is between the minimum flowrate value and the maximum flowrate value of the flowrate range of said regulator member, in particular when the first flowrate setpoint is less than or equal to the highest maximum value of the flow rate ranges of the regulating organs.
• the control unit is configured to select the regulating member whose flow rate range has the highest maximum value, to determine at least one new flow rate set point equal to the difference between the first flow rate set point and said highest maximum value and to select at least one other regulating device so that the new flow rate set point is between the minimum value of flow rate and the maximum value of the flow rate range of said other regulating member.
• the first flow regulator device comprises several regulator members configured to regulate the minority gas flow to the mixing device over successive flow ranges having increasing minimum values and increasing maximum values, the maximum value of at least one flow range being between the minimum value and the maximum value of the successive flowrate range, the control unit being configured to select the regulator member having the smallest minimum flowrate value when the flowrate setpoint or the new flowrate setpoint is between the maximum value of said at least one bit rate range and the minimum value of said successive bit rate range.
• the extent of said at least one flow rate range is defined as the difference between its minimum value and its maximum value and the extent of the overlap zone is defined as the difference between the maximum value of said at least one flow rate range and the minimum value of said successive flow rate range, the overlap zone representing between 15 and 50%, preferably between 15 and 30%, of the extent of said at least one flow rate range.
• Each of the regulating organs can move between a closed position in which the minority gas flow is zero and a completely open position in which the minority gas flow has its maximum value, the regulating organs being able to occupy at least one intermediate position between the position closed and the open position in which the minority gas flow has its minimum value, the minimum value corresponding to a minority gas flow equal to at least 20%, preferably to at least 25%, more preferably to at least 35% , of the respective maximum value.
• the first transfer circuit comprises fluidic isolation means associated with each of the regulating members, said fluidic isolation means being operable so as to allow the flow of the minority gas between the source of minority gas and the mixing device via the said au at least one selected regulator member and to prevent the minority gas from flowing between the source of minority gas and the mixing device via the other non-selected regulator member(s).
• the installation comprises several sources of minority gas, several first transfer circuits fluidically connecting each of the sources of minority gas to the mixing device, the first transfer circuits each comprising a first flow regulator device configured to regulate the flow of minority gas flowing towards the mixing device according to a first flow setpoint determined as a function of a target content of the gas mixture in the minority gas, the installation further comprising third fluidic connection means each arranged as a transfer circuit between a first device respective flow regulator and the mixing device, each of the third fluid connection means comprising at least one distribution valve that can be moved into position so as to allow or prevent the distribution of the minority gas coming from the first flow regulator device and an isolation valve arranged downstream of the distribution valve, said isolation valve being configured to fluidically isolate the distribution valve from the mixing device when the distribution valve is in a position preventing the distribution of the minority gas.
• the pressure lifting device comprises a pump or a compressor.
• the pressure riser is configured such that at least one operating parameter determines the rate of gas mixture flowing to the vessel.
• the second flow regulator device comprises a speed variator of a motor of the pressure lifting device, the speed of rotation of said motor determining the flow rate of gas mixture flowing towards the container, the second flow regulator device comprising a first flow controller connected to the variable speed drive and configured to measure the flow rate of gas mixture flowing to said container, the first flow controller being configured to control and/or adjust a position of the variable speed device so as to cause the measured gas mixture flow rate to tend towards the second flow rate setpoint.
• the second transfer circuit includes a flow sensor or flow meter configured to measure the flow rate of carrier gas flowing to the mixing device.
• the installation comprises an analysis unit configured to measure at least a content of the minority gas and/or the carrier gas of the gas mixture produced at the outlet of the mixing device, the control unit being connected to the control unit. analysis and configured to produce a control signal on the basis of at least one comparison of said at least one measured content with at least one target content of the minority gas and/or a target content of the carrier gas, and to adapt the first flow setpoint in response to said control signal.
• the distribution circuit comprises a buffer tank arranged between the mixing device and the pressure-raising device.
• the installation comprises several containers fluidly connected to the distribution circuit by at least one filling ramp.
• the invention may include one or more of the characteristics set out below.
• the first transfer circuit and the second transfer circuit each comprise an expansion member.
• the regulating members each comprise a flow meter associated with a regulating member.
• the flowmeter comprises a mass flowmeter and the regulating member comprises a valve, in particular a piezoelectric valve.
• At least two of the regulating members are configured to regulate the flow of minority gas over respective flow ranges having distinct minimum flow values and/or distinct maximum flow values.
• All of the regulating members are configured to regulate the flow of minority gas over respective flow ranges having distinct minimum flow values and/or distinct maximum flow values.
• the second transfer circuit is devoid of any flow regulating device to regulate the flow of the carrier gas flowing towards the mixing device.
• the minority gas 1 and the carrier gas 2 are of different natures. They are preferably pure, simple or compound substances.
• Each of the gas sources can be a gas cylinder, typically a cylinder that can have a water volume of up to 50 L, a set of cylinders connected together to form a frame of cylinders or a reservoir of greater capacity, in particular a capacity up to 1000 L, such as a cryogenic storage tank or a tank arranged on a truck-trailer.
• the sources dispense fluids in the gaseous state. Before distribution, the fluids can be stored in the gaseous state, in the liquid state, ie liquefied gas or in the two-phase liquid/gas state.
• an installation is configured to produce a binary gas mixture, ie with two constituents, from two gas sources.
• a binary gas mixture ie with two constituents
• the mixture may thus comprise a carrier gas and several distinct minority gases.
• Minimum gas means a gas whose content in the mixture is lower than the carrier gas content.
• carrier gas is meant a majority gas in the mixture, in particular a gas whose content in the mixture is at least 50%, more particularly at least 60%, or even at least 80%.
• Each of the gas sources 1, 2 is respectively connected by a first 6 and a second transfer circuit 7 to a mixing device 3.
• the first transfer circuit 6 comprises a first pipe 12 and a first flow regulator device 4 connected to a first pipe 12 and configured to regulate the flow of minority gas flowing towards the gas mixing device 3 according to a first flow setpoint D1.
• the installation further comprises a control unit 5 which is connected to the first flow regulator device 4 so as to control their operation in accordance with the first flow setpoint D1.
• the first transfer circuit 6 is advantageously separated into several branches 6a, 6b, 6c, 6d arranged in parallel and each fluidly connected to the source of minority gas 1 on the one hand and on the other hand to the mixer 3. that the branches 6a, 6b, 6c, 6d can either be connected to a common pipe supplying the mixing device 3, as illustrated, or be connected directly to the mixing device 3.
• Each branch 6a, 6b, 6c, 6d comprises a member regulator 41, 42, 43, 44.
• the second transfer circuit 7 comprises a second pipe 22.
• the pipes 12, 22 each open into two separate inlets of the mixer device 3. It should be noted that it is also possible for the pipes 21, 22 to meet at a point of connection located upstream of the mixing device 3 to form a common portion of pipe connected to an inlet of the mixing device.
• the mixer device 3 comprises a common mixer volume into which the inlet(s) and the outlet 33 of the mixer open and in which the mixture is homogenized. It is possible, for example, to use a mixer 3 of the static mixer type allowing continuous mixing of the fluids entering the mixer.
• This type of mixer generally comprises at least one disturbing element, such as a plate, a portion of pipe, an insert, capable of disturbing the flow of fluids, generating pressure drops and/or turbulence to promote the mixing of fluids and its homogenization.
• a distribution circuit 8 connects an outlet of the mixing device 3 to one or more containers 10 adapted to contain the gas mixture.
• the distribution circuit 8 comprises a second flow regulator device 9 configured to regulate and/or adjust the gas mixture flow flowing towards the container 10 according to a second flow set point D.
• the mixer device 3 produces at its outlet a gas mixture flowing with a distribution rate D which corresponds, in the case of a two-component mixture, to the sum of the minority gas and carrier gas flow rates supplying the mixing device 3.
• the flow rate of carrier gas is conditioned by the distribution rate of the mixture D and by the desired content C1 of minority gas. It corresponds to the difference between the mixing flow D and the minority gas flow D1.
• the second transfer circuit does not have any device suitable for regulating and/or adjusting the flow rate of carrier gas, the latter being a result of the flow setpoints for the minority gas and the carrier gas.
• the flow rate D is the sum of the flow rates of each minority gas and of the carrier gas.
• the first flow setpoint D1 is determined according to a target content C1 of minority gas.
• the control unit 5 calculates the first flow rate setpoint D1 in relation to the second flow rate setpoint D desired for the mixture and to the target content C1, so that the ratio D1/D corresponds to C1.
• the normo cubic meter is a unit of measurement of the quantity of gas which corresponds to the content of a volume of one cubic meter, for a gas found under normal conditions of temperature and pressure (0 or 15 or more rarely 20° C according to the standards and 1 atm, i.e. 101,325 Pa). For a pure gas, one normal cubic meter corresponds to approximately 44.6 moles of gas.
• the desired gas mixture is a mixture formed from the minority gas with a target content C1 of 10 ppm (ppm by volume) and from the carrier gas for the rest.
• a first flow setpoint D1 of 0.017 sL/min, corresponding to a proportion of 0.001% relative to D, is therefore applied to the flow regulator device 4. If the target content C1 is 5000 ppm, the total flow being always 100 Nm3/h, the first setpoint D1 is 8.33 sL/min.
• control unit 5 does not calculate the carrier gas flow set point, the fluid circuits of the installation being configured so that the carrier gas flow is regulated via the regulation of the gas flow rates. minority and distribution debit.
• control unit 5 comprises a man-machine interface comprising an input interface, for example a touch screen, allowing the input by a user of the target content of the first gas and of the dispensing rate. desired for the gas mixture.
• the contents can be expressed as a volume percentage of first gas present in the gas mixture.
• the man-machine interface can allow the user to give instructions to the control unit 5.
• control unit 5 comprises a programmable automaton, also called a “PLC” system for “Programmable Logic Controller” in English, that is to say a system for controlling an industrial process comprising a man-machine interface for supervision and a digital communication network.
• the PLC system may include several modular controllers that control plant control subsystems or equipment. These pieces of equipment are each configured to ensure at least one operation among: the acquisition of data from at least one measurement sensor, the control of at least one actuator connected to at least one flow controller device, the regulation and the servoing of parameters, the transmission of data between the various pieces of equipment in the system. Note that on the and on the , the signals received and sent between the different elements of the installation are represented by dotted lines.
• the control unit 5 can thus comprise at least one of: a microcontroller, a microprocessor, a computer.
• the control unit 5 can be connected to the various control equipment of the installation, in particular to the flow regulator organs, to the sensors, and to communicate with the said equipment by electrical links, Ethernet, Modbus, etc.
• electrical links Ethernet, Modbus, etc.
• Other modes of links and/or transmission of information, are possible for all or part of the equipment of the installation, for example by radio frequency links, WIFI, Bluetooth, etc.
• the first flow regulator device 4 comprises several regulating members 41, 42, 43, 44 arranged in parallel in the first transfer circuit 6.
• the regulating members 41, 42, 43, 44 are configured to regulate the flow of minority gas over respective flow rate ranges having distinct minimum flow rate values and distinct maximum flow rate values.
• the control unit 5 is configured to select one of these regulating members 41, 42, 43, 44 on the basis of at least one comparison of the first flow setpoint D1 with the minimum and maximum values of at least one range respective flow rate.
• the control unit 5 is connected to the regulating organs 41, 42, 43, 44. Depending on the result of the comparison, the control unit 5 controls the operation of the regulating organs 41, 42, 43, 44 so as to authorize selectively the flow of the minority gas between the source of minority gas 1 and the mixing device 3 via the at least one regulating member 41, 42, 43, 44 which has been selected by the control unit 5.
• the installation according to the invention makes it possible to simultaneously condition the constituents of the mixture in a container 10.
• the flow of gas mixture is driven by the pressure-lifting member, which ensures a large flow of gas mixture to the container 10 and therefore packaging the mixture faster and in a greater number of containers in a given time.
• the composition of the mixture is more homogeneous between different containers.
• the pressure-lifting device also makes it possible to regulate the flow rate of the gas mixture.
• the selective use of flow regulators according to their operating range and the desired flow setpoint makes it possible to manufacture mixtures whose composition is more precisely controlled.
• the flow regulating members are calibrated components for a given flow rate scale.
• regulators are preset at the factory with reference flow rates.
• the precision of a regulating organ is all the greater as its flow scale is reduced.
• Each regulator member 41, 42, 43, 44 is a flow regulator member which can be any means configured to regulate, regulate, adjust the flow rate of a fluid to bring it to a flow rate value closest to the setpoint, i. e. of the desired value.
• the flow regulating members each comprise a flow sensor, or flow meter, associated with a regulating member, such as a valve, for example a valve with proportional adjustment.
• a regulating member such as a valve
• Such flow regulating members are more precise, which makes it possible to improve the precision of the mixture.
• the valve can be piezoelectric, analog or digital.
• the valve comprises a moving part, typically at least one shutter, which is placed in the fluid flow and whose movement makes it possible to vary the passage section, and thus to vary the flow to bring it to the setpoint value.
• the flow regulator members can be mass flow regulators comprising a mass flow sensor and a proportional control valve. It should be noted that even if the regulation is based on a fluid mass measurement, the setpoint and measured flow rate values are not necessarily expressed in mass. Thus, a volume flow set point can be expressed as a percentage of opening of the proportional control valve, to which corresponds a voltage value to be applied to the control valve of the regulating device. The conversion between percentage of opening in value of mass or volume flow is done by knowing the nominal value of the regulated flow for an opening at 100%.
• the valve is piezoelectric.
• This type of valve offers high precision, good reproducibility thanks to the monitoring of the voltage applied to the valve .
• Such valves are also insensitive to magnetic fields and radiofrequency noise .
• Their power consumption is low with minimal heat generation.
• the metal-to-metal control surface reduces or even eliminates gas reactions.
• the flow regulating members 41, 42, 43, 44 each advantageously comprise a closed loop regulation system which is given flow setpoints by the control unit 5. These setpoints are then compared by the closed loop regulation system. closed with the values measured by the flow rate sensors of the flow regulating members and their positions are adjusted by said system accordingly to send the flow rate as close as possible to the first setpoint D1 to the mixing device 3.
• the first transfer circuit 6 comprises fluidic connection means 61, 62, 63, 64, such as valves, associated with each of the regulating members 41, 42, 43, 44.
• the fluidic connection means 61, 62, 63, 64 are configured in such a way as to prevent fluid communication between the mixing device 3 and the source 1 by regulating members 41, 42, 43, 44 which are not selected.
• each branch 6a, 6b, 6c, 6d comprises a respective regulator member 41, 42, 43, 44 associated with a respective fluid connection means 61, 62, 63, 64.
• the fluidic connection means 61, 62, 63, 64 can be arranged upstream or downstream of the regulating members 41, 42, 43, 44.
• the minority gas coming from the source 1 supplies the regulating members 41, 42, 43, 44.
• the means of fluidic connection 61, 62, 63, 64 which is associated with it is positioned so as to allow the passage of the minority gas towards the mixing device 3.
• the fluidic connection means 61, 62, 63, 64 which is associated with it is positioned so as to fluidically isolate the regulator member from the mixing device 3.
• the fluidic connection means 61, 62, 63, 64 act as fluidic isolation means between the source 1 and the mixer 3. Thus, even when a regulating member is not selected and is therefore in position closed, which corresponds to a zero flow rate setpoint, leaks may still occur through this regulating device.
• the fluidic connection means 61, 62, 63, 64 allow, in addition to the possibility of putting a regulating member in the closed position, to fluidically isolate this regulating member. It is thus possible to avoid any internal leaks, even minimal ones, which could influence the minority gas content of the mixture. This improves accuracy on low grade mixtures, typically down to minimum grades of 2 to 3 ppm.
• control unit 5 is configured to select a single regulator member 41, 42, 43, 44 for which the first flow setpoint D1 is between the minimum value and the maximum value of the flow range of said regulator member. 41, 42, 43, 44.
• the control unit is configured to select several regulating organs within the set of regulating organs 41, 42, 43, 44, so that the first flow setpoint D1 is between the sum of the minimum flow values of the selected organs and the sum of the maximum flow values of the selected organs.
• This possibility is implemented in the case where the first flow setpoint D1 is greater than the highest maximum value of the flow ranges of the regulating members.
• the control unit 5 can be configured in such a way as to determine several intermediate flow setpoints, the sum of which is equal to the first setpoint D1.
• Each selected regulator member regulates a partial flow rate of minority gas according to the intermediate flow set point applied to it.
• the intermediate flows distributed by each regulating member are then recombined to form the flow of minority gas flowing towards the mixing device 3.
• the control unit 5 is configured to select the regulating member whose flow range has the highest maximum value among the regulating members 41, 42, 43, 44 of the installation.
• the electronic logic 5 determines at least one new flow setpoint D n equal to the difference between the first flow setpoint D1 and said highest maximum value and compares the new setpoint D n with a maximum value and/or a minimum value d a flow rate range of at least one other regulating member 41, 42, 43, 44 and selecting another regulating member for which the new flow set point D n is between the minimum flow rate value and the maximum value of the range flow rate of said other regulating member.
• the first flow regulator device 4 comprises several regulator members 41, 42, 43, 44 configured to regulate the minority gas flow to the mixer device 3 respectively over successive flow ranges.
• successive flow ranges which follow one another in increasing order of flow so that these ranges having minimum values d min i , d min i+1 , ... increasing and maximum values d max i , d max i+1 , ... increasing.
• the successive flow ranges can cover a discontinuous flow range, that is to say the flow ranges of each regulating member are not necessarily contiguous. It should be noted that the installation according to the invention can be modulated and that the user can, according to the contents that he wishes to obtain in the mixture, add one or more regulating members whose operating range makes it possible to reach the missing contents.
• the maximum value d max i of at least one flow rate range may be between the minimum value d min i+1 and the maximum value d max i+1 of the successive bit rate range, that is to say the bit rate range coming consecutively to said at least one range in ascending order of bit rate.
• the control unit 5 is configured to select the regulating organ having the minimum flow rate value d min i the smallest when the flow set point D1 is between the maximum value d max i of said at least one bit rate range and the minimum value d min i+1 of said successive flow rate range.
• three flow regulating members operate according to three possible flow ranges, the first range having the lowest minimum value.
• the first range has an overlap zone with the second successive range and the second range has an overlap zone with the third successive range.
• the extent of said at least one flow range is defined as the difference between its minimum value d min i and its maximum value d max i and the extent of the overlap area is defined as the difference between the maximum value d max i of said at least one bit rate range and the minimum value d min i+1 of said successive flow rate range, the extent of the overlap zone representing between 15 and 50%, preferably 15 and 30%, of the extent of said at least one flow rate range.
• each of the regulator members 41, 42, 43, 44 can preferably move between a closed position in which the minority gas flow is zero and a completely open position in which the minority gas flow presents its maximum value d max i , d max i+1 , ..., the regulating members 41, 42, 43, 44 being able to occupy at least one intermediate position between the closed position and the open position.
• the regulating members are configured so that, when they occupy their intermediate position, the minority gas flow is distributed with its minimum value d min i , d min i+1 , ..., the minimum value corresponding to a flow rate of minority gas equal to at least 20%, preferably to at least 25%, more preferably to at least 35%, or even at least 50%, of the respective maximum value of each regulator member.
• the second flow regulator device 9, FC1 comprises a pressure riser 9, in particular a pump or a compressor, at least one operating parameter of which determines the flow rate of gas mixture flowing towards the container 10.
• the second flow regulator device may further comprise a speed variator of a motor of the pressure-lifting member 9.
• the flow rate of gas mixture flowing towards the container 10 varies according to the position of the speed variator which determines the speed of variation of the motor.
• the second flow regulator device may comprise at least a first flow controller FC1 associated with the variable speed drive.
• the pressure lifting device 9 can be provided with a variable speed motor, said motor comprising a variable speed drive controlled by the first controller FC1.
• the first flow controller FC1 receives control signals representative of the second flow rate set point D.
• the flow rate of gas mixture flowing towards the container 10 is measured and compared with the second set point in order to adjust the flow rate accordingly. rotation of the motor and the flow of the mixture to make it tend towards the set value.
• the control unit 5 is electrically or electromagnetically connected to the second regulator device 9 so as to control its operation in accordance with the second flow set point D. It is also possible that the second regulator device 9 be controlled by a system independent of the control unit and connected or integrated with the first flow controller FC1.
• the second transfer circuit 7 comprises a flow sensor or flow meter FC2 configured to measure the flow of carrier gas flowing to the mixing device 3. This makes it possible to have the flow value to adjust the flow of gas minor and thereby the minor gas concentration in real time.
• the first and second transfer circuits are each provided with an expansion device 15, 16, such as a pressure reducer or a valve, and with a pressure sensor PC making it possible to measure the pressure prevailing in these circuits.
• an expansion device 15, 16 such as a pressure reducer or a valve
• a pressure sensor PC making it possible to measure the pressure prevailing in these circuits.
• the minority and carrier gases are preferably each maintained at constant pressures during their distribution to the mixing device 3, preferably between 1 and 10 bar(g) (bar gauge).
• a heater 17, 18 is arranged upstream of each expansion member 15, 16 so as to heat the gases before their expansion. This makes it possible to compensate for the cooling caused by the Joule-Thomson effect during the adiabatic expansion of the gas.
• two expansion members can optionally be arranged in series, preferably with another heater arranged between two expansion members.
• the temperature of the heaters can reach 70 to 100°C.
• the heating power of each heater is controlled individually according to the pressure before expansion and the desired pressure after expansion. Note that at least one heater and at least one pressure reducer can also be arranged on the additional transfer circuits if necessary.
• the installation may comprise an analysis unit 14 configured to measure at least one content of the minority gas and/or the carrier gas of the gas mixture produced at the outlet 33 of the mixer device 3.
• the control unit 5 is electrically or electromagnetically connected to the analysis unit 14 and receives from the analysis unit 14 a measurement signal representative of said at least one measured content. In operation, the control unit 5 performs at least one comparison between said measured content and the corresponding target content of minority gas and/or carrier gas.
• the analysis unit 14 is configured to analyze only the content of the minority gas in the gas mixture.
• control unit 5 is configured to maintain or adjust the first flow setpoint D1 applied to the first regulator device 4 so as to maintain or to make the measured content tend towards the target content. This makes it possible to adjust the proportion of the first flow setpoint D1 with respect to the distribution flow D so that the effective composition of the gas mixture leaving the mixing device 3 approaches the target composition.
• This control of the contents of the mixture produced by the mixing device makes it possible to compensate for any errors between the flow rate actually regulated by the first flow regulator device 4 and the flow set point D1 which is applied to it.
• the mixing device 3 produces a mixture whose control can be carried out continuously. It should be noted that a difference between the measured and target contents can also come from the uncertainty on the flow rate of distribution of the mixture which may not correspond exactly to the second flow set point D applied to the second regulating device 9.
• control unit 5 can comprise a loop for controlling the flow of minority gas on the measurement signal supplied by the analysis unit 14.
• control loop is generally meant a control system of a process in which a manipulated variable acts on a controlled variable, i. e. a quantity to be controlled, to bring it as quickly as possible to a set value and maintain it there.
• the basic principle of a control is to continuously measure the difference between the real value of the quantity to be controlled and the setpoint value that one wishes to reach, and to calculate the appropriate command to be applied to one or more several actuators in order to reduce this difference as quickly as possible. It is also referred to as a closed-loop controlled system.
• the regulating variables are the content(s) measured by the analysis unit 14, the regulated variable is the flow rate of the minority gas.
• the first setpoint D1 is variable according to the actual content(s) measured.
• Said loop comprises a comparator arranged within the control unit 5 and configured to produce at least one error signal from the comparison of the measurement signal with the target content C1 in the minority gas and/or the content target C2 into the carrier gas.
• the loop further comprises a corrector, in particular of the proportional, integral and derivative (PID) type, which makes it possible to improve the performance of a servo-control thanks to three combined actions: a proportional action, an integral action, a derivative action .
• PID proportional, integral and derivative
• the corrector may include in particular a microprocessor, memory registers, programming instructions for processing the first error signal and developing by digital calculation the terms proportional, integral, and derivative of the servo loop. These terms, which can be determined by calculation and/or experimentally, are combined to provide the control signal for the regulating members 41, 42.
• the term derived from D can optionally be zero.
• the corrector is configured to generate the control signal from the error signal representative of a difference between the target content and the measured content. If there is a deviation, the first flow setpoint D1 is modified in accordance with the first control signal.
• the regulating members 41, 42, 43, 44 are connected to the corrector and configured to move in response to said control signal so as to reduce the deviation.
• control signal is generated from an error signal containing at least information on the difference between a measured content and a target content, for the minority gas.
• the relative difference ⁇ C1 can be used as a correction factor for the first flow set point D1.
• the analysis unit can also make it possible, during the start-up of the installation or during the filling of the container 10, to condition the distribution of the gas mixture to the conformity of the contents measured with the target contents.
• a tolerance of the order of 1% at most, or even 0.7% at most (% relative), in relation to the target levels C1, C2 can be set. If the mixture produced is not compliant, the filling may possibly be stopped.
• the gas mixture produced can optionally be distributed to a vent fluidly connected to the distribution circuit 8, in particular in the case where the composition of the mixture does not conform to the target composition.
• the pipe taking the mixture and leading it into the analysis unit 14 advantageously has the shortest possible length so that the analyzer provides a very precise response in real or near real time.
• the pipe is such that the time lag between the moment when the mixture is sampled at its sampling point and the moment when the analysis unit gives its measurement is minimal, typically less than 30 seconds, in particular between 1 and 30 seconds.
• the distribution circuit 8 comprises a buffer tank 11.
• the buffer tank 11 is arranged between the mixer device 3 and the second flow regulator device 9, FC1.
• the buffer tank 11 makes it possible to dampen the pressure fluctuations at the inlet of the second flow regulator device 9 and to complete the homogenization of the mixture leaving the mixer.
• the analysis unit 14 is fluidically connected to the distribution circuit 8 at a sampling point located between the outlet of the mixing device and the inlet of the buffer tank 11. This makes it possible to detect and react more quickly to d possible variations in content, further reducing the risk of packaging a non-compliant mixture in the container 10.
• the installation can include an alarm configured to emit an alarm signal if the analysis unit detects levels outside the expected tolerance ranges.
• the analysis unit 14 can be chosen in particular from among the following types of detectors: a thermal conductivity detector, a paramagnetic alternating pressure detector, a catalytic adsorption detector, a non-dispersive infrared absorption detector, a spectrometer infrared.
• the type of analysis unit can be adapted according to the nature of the gases to be analyzed.
• only the first setpoint D1 is adjusted according to the measurement of the analysis unit 14, the control unit 5 commanding the maintenance of the second setpoint D. It being understood that it is possible that D also be adjusted in response to the control signal.
• the installation advantageously comprises several containers 10 fluidly connected to the distribution circuit 8 by a filling ramp 60.
• the filling ramp 60 is configured for filling several containers 10 from the same distribution circuit 8, which is particularly advantageous in terms of filling efficiency and homogeneity of composition of the mixture between the containers 10.
• the filling ramp 60 can be connected to an independent control system or to the control unit 5.
• the filling ramp 60 preferably comprises a set of automatic valves which are configured to open upon filling of a container and to close when the desired amount of gas mixture has been introduced into the container.
• the automatic valves can be connected to a system for measuring the quantity of gas in each container, such as a weighing device for each container 10, so that when the desired quantity of gas is reached in the container considered, the automatic valve corresponding is closed and the automatic valve of another container is opened in order to fill it.
• the target contents C1 of minority gas are between 1 ppm and 40%, preferably between 2 and 20%, the remainder being the carrier gas.
• the installation according to the invention can also be used to produce gas mixtures such as those used in the field of electronics, in particular in the process of manufacturing integrated circuits and the production of semiconductors, in particular doping of silicon wafers.
• the gas mixture can thus comprise a carrier gas such as argon, nitrogen, helium and at least one doping gas as minority gas whose formula contains for example germanium, phosphorus, arsenic , antimony, boron, gallium, aluminum.
• the present description describes a gas mixture with two constituents but that it can be transposed to any mixture having a greater number of constituents.
• three sources distribute two types of minority gas and a carrier gas.
• Flow regulating members receive instructions from the control unit 5 to regulate the flow of each minority gas to a respective flow setpoint D1A, D1B.
• the mixer device is configured to distribute a mixture of flow rate D equal to the sum of D1A, D1B, D2. All or part of the characteristics already described for a mixture with two gases can be transposed to this mixture with three or more gases.
• the installation comprises third fluid connection means 20A, 20B each arranged in a transfer circuit 6A, 6B between a first respective flow regulator device 4A, 4B and the mixing device (3).
• Each of the third fluid connection means 20A, 20B comprises at least one dispensing valve. The distribution valve, depending on its position, prevents or allows the passage of the minority gas to the mixing device 3.
• the isolation valve is configured so as to be able to fluidically isolate the distribution valve from the mixer 3. This makes it possible to ensure that each minority gas distributed by the flow regulator device 4A, 4B is quickly available because it is waiting under pressure upstream from the third fluid connection means 20A, 20B.
• the isolation valve and the distribution valve are connected by a portion of pipe to which is connected a pressure measuring device and an evacuation valve.
• a pressure measuring device In the event of failure of one of the valves, in particular in the event of a leak, an abnormal accumulation of gas takes place at the level of the portion of the pipe, which generates an increase in the pressure measured by the measuring device. If this pressure exceeds a certain threshold, the opening of the evacuation valve can be triggered, in particular by the control unit 5, in order to vent the accumulated gas and thus prevent it from contaminating the gas. minority or gas mixture.
• the precision on the mixture is further improved.
• the installation can be implemented to distribute a mixture comprising, as required, one or the other of the minority gases.
• Minority gas sources are available on site and the desired source is connected with its flow control device to the mixing device. It is also possible to connect the two minority gas sources 1A, 1B to the mixing device so as to distribute a mixture containing the two minority gases.
• Each minority gas module comprises a first wall 51 on which are fixed a first transfer circuit 6 and first fluid connection means 30 of the first transfer circuit 6 to a respective source of minority gas 1A.
• Each carrier gas module has a second wall 52 on which are fixed the second transfer circuit 7 and second fluidic connection means 40 of the second transfer circuit 7 to a source of carrier gas 2.
• Third fluidic connection means 20 are provided for selectively connecting the mixing device 3 to one or more first transfer circuits 6 and to the second transfer circuit 7.
• the gas sources of the installation, the control unit 5, the gas modules are positioned at a distance from each other and form physically distinct and independently movable sets.
• the advantage of such an arrangement is to be flexible according to the needs of the user in terms of nature and flow rate of the gases in the mixture.
• Modules can be added or removed from the installation to adapt to a change in the constituents of the mixture.
• elements such as pressure regulators, gas heaters, flow regulators can also be added or removed to adapt to a change in target content and therefore to a change in the desired flow rate for the gas minority.
• the modules include gas inlet openings for minority and carrier gas supply.
• Other gas inlets may be provided, in particular for a sweep gas or a standard gas for calibrating the analysis unit.
• a buffer tank a system of gas pipes
• means of control and/or maintenance of the pipe system of gases such as valves, regulators, pressure measuring devices, etc. allowing operations such as gas distribution, opening or closing of certain pipes or pipe sections, management of the gas pressure, carrying out purge cycles, leak tests, etc.

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• 2021
  • 2021-12-20 FR FR2113983A patent/FR3130638B1/fr active Active
• 2022
  • 2022-11-28 CN CN202280078789.5A patent/CN118475893A/zh active Pending
  • 2022-11-28 WO PCT/EP2022/083406 patent/WO2023117307A1/fr not_active Ceased
  • 2022-11-28 EP EP22822155.2A patent/EP4453684A1/de active Pending
  • 2022-11-28 US US18/722,240 patent/US20250050285A1/en active Pending
  • 2022-11-28 KR KR1020247023601A patent/KR20240128881A/ko active Pending

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