SMART GAS MIXER

Abstract

A gas mixer device for mixing a plurality of gases to generate a gas mixture comprising a desired composition, wherein the gas mixer device comprises: a chassis supporting a mixing chamber for receiving the respective gas and storing said gas mixture, and a plurality of mass flow controllers configured to measure and control a mass flow of the respective gas. According to the present invention, the respective mass flow controller is configured to be releasably connected to the chassis. Furthermore, the present invention relates to a method for generating a gas mixture comprising a desired composition.

Claims

1-15. (canceled)

16. A gas mixer device for mixing a plurality of gases (G1, . . . , GN) to generate a gas mixture (G) comprising a desired composition, wherein the gas mixer device comprises: a chassis (200) supporting a mixing chamber for receiving the respective gas (G1, . . . , GN), and a plurality of mass flow controllers (10) configured to measure and control a mass flow of the respective gas (G1, . . . , GN), wherein the respective mass flow controllers (10) are configured to be releasably connected to the chassis (200).

17. The gas mixer device according to claim 16, wherein the respective mass flow controller comprises an inlet connected to a gas source, an outlet for passing gas into the mixing chamber, a mass flow sensor and a control valve, wherein the respective mass flow controller further comprises a controller which is configured to receive an input signal from a control unit of the gas mixer device, wherein the controller is configured to compare the input signal to an output value provided by the mass flow sensor and to adjust the control valve accordingly to achieve a desired mass flow.

18. The gas mixer device according to claim 16, wherein the chassis comprises a plurality of slots, wherein each slot is configured to receive one of the mass flow controllers.

19. The gas mixer device according to claim 18, wherein every slot comprises electrical contacts for establishing an electrical connection to a mass flow controller so that the mass flow controller is provided with electrical energy via said electrical contacts when the mass flow controller is inserted into one of the slots, and/or wherein the respective slot provides a flow connection to the mixing chamber when the mass flow controller is inserted into one of the slots, and/or wherein the respective slot provides a communication connection between a controller of a mass flow controller and the control unit, when the mass flow controller is inserted into a slot of the chassis.

20. The gas mixer device according to claim 18, wherein the control unit of the gas mixer device is configured to recognize a mass flow controller once the mass flow controller has been inserted into a slot of the chassis.

21. The gas mixer device according to claim 17, wherein the chassis comprises a plurality of slots, wherein each slot is configured to receive one of the mass flow controllers, wherein the control unit is configured to execute a control software that is configured to receive the desired composition of the gas mixture to be mixed and/or a volume per time of the respective gas and/or mass flow rate of the respective gas as input data and to provide said input data to the mass flow controllers inserted into slots of the chassis.

22. The gas mixer device according to claim 16, wherein the gas mixer device comprises a plurality of sensors, wherein the sensors are configured to monitor the composition of the gas mixture in real time.

23. The gas mixer device according to claim 22, wherein the respective sensor is configured to be releasably fastened to the chassis.

24. The gas mixer device according to claim 17, wherein the control unit is configured to track at least one of: the composition of the gas mixture, a flow rate of the gas mixture, a humidity of the gas mixture, a temperature of the gas mixture, a pressure of the gas mixture.

25. The gas mixer device according to claim 16, wherein the gas mixer device is configured to be connected to a welding device to provide the gas mixture to the welding device to be used in a welding process, and wherein particularly the gas mixer device is configured to check fulfillment of a welding procedure specification of the welding device to ensure that a correct gas mixture is delivered to the welding device.

26. The gas mixer device according to claim 17, wherein the gas mixer device is configured to check the respective gas source connected to an inlet of a mass flow controller, wherein particularly the control unit is configured to block a gas source in case it does not fulfill a pre-defined requirement.

27. The gas mixer device according to claim 25, wherein the gas mixer device is configured to adjust the composition of the gas mixture upon conducting a welding process using the welding device.

28. The gas mixer device according to claim 16, wherein the gas mixer device comprises a gas filter for filtering one of the following substances out of the gas mixture: oxygen, H.sub.2O.

29. The gas mixer device according to claim 16, wherein the gas mixer device comprises a plurality of outlets, wherein the gas mixer device is configured to supply the respective outlet of said plurality of outlets with a gas mixture mixed by the gas mixer device, wherein the gas mixer device is configured to supply the plurality of outlets with identical gas mixtures, or wherein the gas mixer device is configured to supply each outlet of said plurality of outlets with a different gas mixture.

30. A method for generating a gas mixture using a gas mixer device according to claim 16, comprising the steps of: releasably connecting a number of mass flow controllers to the chassis, wherein the inlets of the mass flow controllers are connected to different gas sources containing gases to be mixed, feeding the respective gas via the respective mass flow controller into the mixing chamber to generate a gas mixture in the mixing chamber that comprises a desired composition, wherein the mass flow of the respective gas into the mixing chamber is controlled by means of the respective mass flow controller.

Description

[0031] In the following, embodiments, further features, and advantages of the present invention shall be described with reference to the FIGURE, wherein

[0032] FIG. 1 shows a schematical illustration of an embodiment of a gas mixer device according to the present invention.

[0033] FIG. 1 shows an embodiment of a gas mixer device according to the present invention.

[0034] Particularly, the gas mixer device 1 is configured to mix a plurality of gases (G1, . . . , GN) contained in gas sources such as gas cylinders 20 to generate a gas mixture G comprising a desired composition. As shown in FIG. 1, the gas mixer device 1 comprises a mixing chamber 2 (e.g. in form of a piping) for receiving the respective gas (G1, . . . , GN). The size of the mixing chamber 2 may be adjusted to accommodate the needed response time of the application in question. Further, the gas mixer device comprises a chassis 200 holding the mixing chamber 2, wherein the chassis 200 is configured to receive and a number of mass flow controllers 10 corresponding to a number N of different gases G1, . . . , GN to be mixed. Particularly, the respective mass flow controller 10 is configured to be releasably connected to the chassis 200 by inserting the respective mass flow controller 10 into an associated slot 14 provided on the chassis 200.

[0035] Furthermore, the respective mass flow controller 10 comprises an inlet 10a connected to the respective gas source 20, an outlet 10b for passing the respective gas G1, . . . , GN into the mixing chamber (e.g. tubing) 2, a mass flow sensor 12 and a control valve 13, wherein the respective mass flow controller 10 further comprises a controller 11 which is configured to receive an input signal from a control unit 3 (e.g. via a communication unit 5 of the gas mixer device 1), wherein the respective controller 11 is configured to compare the input signal indicative of the desired composition of the final gas mixture G to an output value provided by the respective mass flow sensor 12 and to adjust its control valve 13 accordingly to achieve a desired mass flow (and therewith composition of the desired gas mixture G)

[0036] The mass flow controller compilation of the device 1 can now be adjusted to the welding task, regarding the type of gas, the number of gases G1, . . . , GN, the flow rate, and accuracy.

[0037] Once an MFC 10 is connected to the chassis 200 by inserting it into a slot 14 (e.g. clicked in) it is recognized by a control software executed on the control unit 3 (e.g. a mobile phone or some other computer). In the control software the gas mixture's composition to be achieved can be set. Particularly, if a gas mixture G is chosen that cannot be mixed in an optimal way by the respective MFC 10 connected to the chassis 200 the control software can give an advice what kind of MFC 10 needs to be added or changed.

[0038] Particularly, the quality of the gas mixture G is ensured by the use of calibrated MFC 10, and the right choice of the type of MFC 10 taking into account the inaccuracy and aging. Furthermore, sensors S1, . . . , SN can be used to monitor in real time the gas composition. According to an embodiment, these sensors can be clicked into the device 1 like the MFCs 10. Alternatively or in addition, a single gas sensor S may also be arranged downstream the mixing chamber 2 (e.g. at an outlet 4a of the gas mixer device 1).

[0039] Particularly, the gas mixer device 1 can be configured to automatically recognize the Sensors S1, . . . SN and use them for monitoring the gas mixture G. By using the sensors S1, . . . SN it can be recognized when the individual MFC 10 should be recalibrated.

[0040] Furthermore, the gas mixer device 1 can be configured to track the gas mixture's composition, flow rate, humidity, temperature and pressure. Particularly, this data can be saved and printed as a certificate.

[0041] Furthermore, the gas mixer device 1 can be connected (e.g. via the outlet 4a) to any other system like for example a power supply or a welding device 4. When checking the fulfillment of a welding procedure specification (WPS), the gas mixer device 1 can be configured to ensure that the right gas mixture G is used. The gas mixer device 1 can comprises a plurality of outlets 4a, 4b (for simplicity only two outlets are shown), wherein the outlets 4a, 4b can be connected to different devices 4, 41 that may need equal or different gas compositions. Several outlets 4a, 4b may also be connected to the same device. For example, one single welding station connected to several outlets 4a, 4b, . . . may receive several gas mixtures with a different composition and for example with a different flow and/or pressure. An example is a plasma application that needs shielding gas, plasma gas, focus gas, trailing gas and purging gas. Thus, the outlets 4a, 4b, . . . can be provided with the same gas mixture G or with different gas mixtures depending on the specific application. The outlets 4a, 4b, . . . can be connected to the same mixing chamber 2. However, particularly in case different mixtures are needed at the outlets 4a, 4b, . . . , the gas mixer device 1 can also comprise multiple mixing chambers 2, 21, . . . , wherein the outlets 4a, 4b can be connected to different mixing chambers 2, 21. Several mixing chambers 2, 21 can be connected to the outlets 10b of the mass flow controllers 10 on the inlet side of the gas mixer device 1 via suitable valves.

[0042] Furthermore, the flow rates of the gas mixture provided at the respective outlet 4a, 4b can be equal or different (depending on the respective application to which the respective gas mixture is provided).

[0043] As an option the gas mixer device 1 can be configured to check the connected gas cylinders 20 by e.g. using a bar code scanner and/or RFID equipped cylinders 20. Any alternative cylinder identification system could be used instead. If available also the filling certificate could be used to check if the required specification of the gas mixture G can be fulfilled.

[0044] Further, the control software of the gas mixer device 1 can be configured to block cylinders/gas sources 20 in case they do not fulfill the requirements.

[0045] Furthermore, according to an embodiment, the gas mixture's G composition can be adjusted while welding, e.g. according to signals like the welding current of the welding device 4 or according to a time or a temperature (e.g. Interpass temperature). The small size of the gas mixer device 1 allows to position the mixer 1 close to the process. In addition, as no buffer is used, the small gas volume between the MFC and the process allows very short reaction times in which the gas composition can be adjusted. Preferably, the response of the gas mixer device 1 is of the order of microseconds for optimum flexibility.

[0046] As an additional option, it is possible to implement a gas filter for filtering oxygen, humidity etc. out of the gas mixture G to ensure best quality.