Description:“A SYSTEM FOR MIXING SHIELDING GASES IN GAS TUNGSTEN ARC WELDING AND METHOD THEREOF”

FIELD OF INVENTION
[0001] The present disclosure relates to a system and process of mixing gases for the welding process. More particularly, the invention relates to a system and method for mixing shielding gases for supply to ignite the arc in gas tungsten arc welding (GTAW) process to achieve improved weld quality
BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Welding stainless steel and nickel-based alloys presents a unique challenge compared to welding carbon steels, primarily due to the thermal conductivity and material properties of these metals. When an optimized heat input is applied, the depth of penetration is typically less for stainless steel and nickel alloys than for carbon steel because these materials have a higher rate of heat dissipation that increase the heat input to achieve greater penetration can lead to problems such as micro cracking and the introduction of defects in the weld or the heat-affected zone (HAZ). These defects can compromise the structural integrity and performance of the welded joint.
[0004] To circumvent this issue without increasing heat input, a dual shielding gas approach can be utilized. This involves mixing two different shielding gases in suitable proportions to enhance the depth of penetration during the Gas Tungsten Arc Welding (GTAW) process, also known as Tungsten Inert Gas (TIG) welding. Shielding gases can influence several aspects of the welding process, including the stability of the arc, penetration profile, and the mechanical properties of the weld. However, the physical properties of the gases, such as density, play a significant role in their behavior when mixed. Lighter gases tend to rise while heavier gases sink. If premixed gases are stored in a cylinder, there's a risk that they may separate over time due to density differences, with the lighter gas potentially flowing out first when the valve is opened. This separation would result in an inconsistent gas mixture being delivered during the welding process, which could affect the quality and properties of the weld. In welding of stainless steel and Ni based alloys, to increase the depth of penetration instant of single shielding gas, two gas mixer suitable percentage may enhance the depth of penetration. Due to density difference, possibility of lighter weight gas may flow out first from the mixed gas cylinders.
[0005] To ensure a consistent mixture of shielding gases and to maintain the optimal properties of the weld, an instant gas mixing system is preferred. Such systems mix the gases in real-time and deliver them directly to the weld pool, thus eliminating the risks associated with premixed gas cylinders. An on-site gas mixer allows for precise control over the mixture proportions and provides a consistent flow rate of the intended gas mixture during the GTAW process. By using an instant gas mixer, welders can achieve the desired depth of penetration without compromising the integrity of the weld through excessive heat input, thereby avoiding the associated defects and improving the quality of the welds on stainless steel and nickel-based alloys.
PRIOR ARTS
[0006] A state of art US20080053965A1 relates to an apparatus for shielding gas mixture providing a first gas in a liquefied state; providing a second gas in a gaseous state; vaporizing the first gas to a gaseous state; and blending the first gas with the second gas to form the shielding gas mixture. The invention involves the mixing of gases in liquidities and gaseous state.
[0007] Another state of art US4902866A relates to an improved gas mixing apparatus for dispensing a specific ratio of two or more gases mixed together for supplying the mixture to a gas metal arc welding machine using pair of Y members coupled fittings. The state of art lacks the concept of Y members coupled fittings are not used.
[0008] Yet another state of art US20130112660A1 relates to an arc system is described which includes a power generator, a shielding gas source, a torch and a shielding gas monitor contained adjacent to or within the torch. The prior art lacks the shielding gas mixing unit.
[0009] Another state of art US20110290772A1 relates to an arc welding method that implements an arc welding torch provided with an electrode, in which a central gas flow is supplied so as to contact the electrode and an annular gas flow is supplied. on the periphery of said first gas flow. The prior art deals with multi-layer different mixed gases.
[0010] Yet another state of art IN255161 relates to an apparatus and process for alternate supply of shielding gas to the gas metal are welding (GMAW) torch. The method delivers two different shielding gases alternatively to the GMAW torch directly without any pre-mixing. The prior art lacks the premixed gases for GTAW process and pulsing unit is used for exact setting of percentage of gases.
[0011] The contemporary prior art faces several challenges that necessitate the development of the present invention. In welding of stainless steel and Ni based alloys, due to thermal conductivity of materials, the given optimized heat input will have provided very low depth of penetration comparing to carbon steels. On the increase the depth of penetration with increasing the heat input may lead to micro cracking or/and defects in the weld or heat affected zone of the weldment. To avoid this scenario, instant of single shielding gas, two gas mixer suitable percentage may enhance the depth of penetration. In common, due to density difference, possibility of lighter weight gas may flow out first from the mixed gas cylinders. Hence, ready mixer gas cylinders are not suitable for all the type of gas mixtures. So, instant gas mixture is required for GTAW process. These challenges collectively hinder the efficiency and reliability. Thus there is a pressing need to achieve the same.
OBJECTS OF THE INVENTION
[0012] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0013] It is an object of the present subject matter to provide title, which overcomes the aforementioned and other drawbacks existing in the prior art fixture and methods.
[0014] It is a principal object of the present subject matter to introduce a system and method to efficiently mix shielding gases for use in the Gas Tungsten Arc Welding (GTAW) process with a consistent and controlled supply of mixed shielding gases directly to the GTAW torch.
[0015] It is another significant object of the present subject matter to propose the system and method to optimize the percentages of mixed shielding gases to the GTAW torch.
[0016] It is another significant object of the present subject matter to propose the system and method to enhance the welding performance by providing a means to accurately and effectively mix different shielding gases in real-time, catering to the specific needs of the welding process and materials involved.
[0017] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taking into consideration with accompanied drawings in which preferred embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION
[0018] This summary is provided to introduce the concept of a system and method ofr mixing shielding gases in gas tungsten arc welding (GTAW) The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0019] The present invention discloses a system and method ofr mixing shielding gases in gas tungsten arc welding (GTAW) in accordance with an embodiment of the present disclosure. The system for mixing shielding gases in gas tungsten arc welding (GTAW) process comprises of a plurality of gas cylinders that are connected for storing different gases, a plurality of gas Regulators attached to each gas cylinder configured to control the pressure of the gas exiting the cylinders. A gas alternator is connected to the gas cylinders, equipped to control the gas flow. The gas alternator is provided with programmable timer-based flow valves to control the percentage of each gas by varying the gas flow duration to a single output. A mixing cylinder is connected to the gas alternator for thoroughly mixing the gases received from the gas alternator and regulating the gas pressure and a two-way flow valve connecting the mixing cylinder to regulate the flow of the gas. A vacuum pump is connected to two-way flow valve for evacuating the mixing cylinder before starting a new gas mixture and a flow meter is connected to two-way flow valve configured to control of the flow rate of the gas. A welding power source connected to the flow meter for receiving the mixed gases and a welding torch (connected to the welding power source, connected to utilize the mixed gases for welding applications on a plate material. A pressure gauge is connected for monitoring the pressure levels in the gas cylinders and the mixing cylinder.
[0020] In one aspect, a method for mixing shielding gases for supply to ignite the arc in gas tungsten arc welding (GTAW) process comprises of setting a predetermined pressure in the gas cylinders using gas regulators, programming the gas alternator with specific time intervals corresponding to the desired percentage mix of each gas. This is followed by activating the vacuum pump to evacuate the mixing cylinder prior to introducing the gases and initiating gas flow from the cylinders to the gas alternator. The gases are alternated based on the programmed time intervals and directed to the mixing cylinder. The gases are mixed in the mixing cylinder at a predetermined pressure for a homogeneous blend and directing the mixed gas from the mixing cylinder to the welding torch through the flowmeter.
[0021] In another aspect, two or more different shielding gases is selected from plurality of a gas including argon, hydrogen, helium, Nitrogen, oxygen and carbon dioxide.
[0022] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0024] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of improved fixture or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which
[0025] Fig. 1 illustrates the schematic diagram of the system for mixing shielding gases in gas tungsten arc welding (GTAW) in accordance with an embodiment of the present disclosure.
[0026] Fig. 2 illustrates the front view of the system for mixing shielding gases in gas tungsten arc welding (GTAW) in accordance with an embodiment of the present disclosure.
[0027] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
[0028] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
[0029] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0030] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the “invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0031] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0032] Various embodiments are further described herein with reference to the accompanying figures. It should be noted that the description and figures relate to exemplary embodiments and should not be construed as a limitation to the subject matter of the present disclosure. It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the subject matter of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the subject matter of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof. Yet further, for the sake of brevity, operation or working principles pertaining to the technical material that is known in the technical field of the present disclosure have not been described in detail so as not to unnecessarily obscure the present disclosure.
[0033] The invention relates to a system and a method for mixing and supply of two shielding gases to a Gas Tungsten Arc Welding (GTAW) torch. Shielding gas is the gas to provide the ion column from the welding Arc. The most commonly used inert gases are argon and helium. The welding Arc shape and temperature varies with change of shielding gas purity and it is ionization potentials. Higher ionization potential gas can penetrate the base plate deeper. Helium has a higher ionization potential (24.5 V) compared with argon (15.7 V), still the argon is cheaper in India, due to its availability. To enhance the penetration capacity of Argon, mixing of active gases like Nitrogen, oxygen may help up to certain percentage. In particular, welding of stainless steel and Ni based alloys, due to thermal conductivity of materials and the given optimized heat input will have provided very low depth of penetration comparing to carbon steels. If, we try to increase the depth of penetration with increasing the heat input may lead to micro cracking or/and defects in the weld or heat affected zone of the weldment. To avoid this scenario, instant of single shielding gas, two gas mixer suitable percentage may enhance the depth of penetration. In common, due to density difference, possibility of lighter weight gas may flow out first from the mixed gas cylinders. Hence, ready mixer gas cylinders are not suitable for all the type of gas mixtures. Therefore, instant gas mixture is required for GTAW process.
[0034] Fig. 1 illustrates the schematic diagram of the system for mixing shielding gases in gas tungsten arc welding (GTAW) in accordance with an embodiment of the present disclosure. The system(100) for mixing shielding gases in gas tungsten arc welding (GTAW) process comprises of a plurality of gas cylinders (1, 2), connected for storing different gases, a plurality of gas Regulators (3) attached to each gas cylinder (1,2), configured to control the pressure of the gas exiting the cylinders (1,2). A gas alternator (4) is connected to the gas cylinders (1,2), equipped to control the gas flow. The gas alternator (4) is provided with timer-based flow valves to control the percentage of each gas by varying the gas flow duration to a single output. A mixing cylinder (5) is connected to the gas alternator for thoroughly mixing the gases received from the gas alternator (4) and regulating the gas pressure and a two-way flow valve (6) connecting the mixing cylinder (5) to regulate the flow of the gas. A vacuum pump (7) is connected to two-way flow valve (6) for evacuating the mixing cylinder (5) before starting a new gas mixture and a flow meter (8) is connected to two-way flow valve (6) configured to control the flow rate of the gas. A welding power source (9) is connected to the flow meter (8) for receiving the mixed gases and a welding torch (10) is connected to the welding power source (9), connected to utilize the mixed gases for welding applications on a plate material (11). A pressure gauge (12) is provided for monitoring the pressure levels in the gas cylinders and the mixing cylinder.
[0035] The plurality of gas cylinders (1, 2) are provided for storing the different types of gases to be mixed and provide the base ingredients for the gas mixture. The gas regulators (3) are attached to the gas cylinders for controlling the pressure of gas exiting the cylinders (1,2) which ensure a consistent and controlled gas flow at a predetermined pressure, typically set at one bar, essential for accurate gas mixing.
[0036] The gas alternator (4) is equipped with multiple timer-based flow valves which allow for precise control over the proportion of each gas in the final mixture by adjusting the duration each gas is allowed to flow. The timers can be set to allow a specific gas to flow for a certain number of milliseconds, controlling its percentage in the mixture.
[0037] After the gases pass through the gas alternator (4), gas enters the mixing cylinder (5) where they are thoroughly mixed. The mixing cylinder (5) ensures a homogeneous blend of gases and regulating the pressure of the mixed gases. The two-way flow valve (6) is positioned at the outlet of the mixing cylinder (5) and directs the mixed gases either towards the flow meter (8) and subsequently to the welding torch (10) or towards the vacuum pump (7) for purging.
[0038] The vacuum pump (7) ensures purity in the gas mixture, the mixing cylinder is evacuated before introducing a new mixture. The vacuum pump (7) removes any residual gases from the cylinder, preventing contamination of the new mixture.
[0039] The flow meter (8) is connected to the mixing cylinder (5) configured for controlling the flow rate of the gas mixture and ensures the proper amount of gas is delivered to the torch (10), which is vital for achieving high-quality welds. The welding power source (9) is connected to the flow meter (8) for supplying the current to the system (100).
[0040] The pressure gauges (12) are used to monitor the pressure within the system (100) for maintaining the correct pressure is critical for the accuracy of the gas mixing process.
[0041] Fig. 2 illustrates the front view of the system for mixing shielding gases in gas tungsten arc welding (GTAW) in accordance with an embodiment of the present disclosure.
[0042] In this invention, gas mixture setup is designed and developed for mixing of two different gases with various percentages. The same setup is capable of mixing multiple number of gases (1, 2) with additional timer flow valve in gas alternator (4). This setup comprises of gas alternator (4), mixing tank (5) with vacuum pump (7), pressure gauges (12) and flow meter (8). The gas cylinders (1, 2) are connected to gas alternator (4), gas flow set as one bar pressure in all cylinders as content flow using gas regulators (3). The gas alternator (4) defined as set of multiple number of timer (100 milliseconds timer) based flow valves to control the percentage of the gas by changing gas flow time to a single output. Gas alternator (4) is connected to mixing cylinder (5). Mixing cylinder (5) is used for proper mixing of gases from alternator and acts as a medium to regulate gas pressure to welding torch via flow meter (8).
[0043] Mixing cylinder outlet line is connected to a two-way flow valve (6). One end of outlet of two-way valve (6) is connected to flow meter (8) which directs to welding torch. Another end of two-way valve (6) is connected to a vacuum pump (7) to avoid contamination from pervious stored gas in mixing cylinder (5). Mixing cylinder (5) is vacuumed before starting the new mixing percentage.
WORKING OF THE INVENTION:

[0044] A method for mixing shielding gases for supply to ignite the arc in gas tungsten arc welding (GTAW) process comprises of setting a predetermined pressure in the gas cylinders (1,2) using gas regulators (3), programming the gas alternator (4) with specific time intervals corresponding to the desired percentage mix of each gas. This is followed by activating the vacuum pump (7) to evacuate the mixing cylinder (5) prior to introducing the gases and initiating gas flow from the cylinders (1,2) to the gas alternator (4), wherein the gases are alternated based on the programmed time intervals and directed to the mixing cylinder. The gases are mixed in the mixing cylinder (5) at a predetermined pressure for a homogeneous blend and directing the mixed gas from the mixing cylinder (5) to the welding torch (10) through the flowmeter (8).
[0045] The two or more different shielding gases are selected from plurality of a gas including argon, hydrogen, helium, Nitrogen, oxygen and carbon dioxide. For example, welding application required for a mixing gases of 95% Argon with 5% Hydrogen. Argon gas cylinder (1) and hydrogen gas cylinder (2) were connected to the alternator (4). The gas flow in the pressure gauges were set to be one bar pressure in both hydrogen and argon cylinders. In alternator (4) Argon gas timer need to be set to 95 milliseconds and hydrogen gas timer need to be set to 5 milliseconds. It leads to first 95 milliseconds argon solenoid valve (12) (Solenoid valves are electromechanically operated valves that control the flow of gases. They convert electrical energy into mechanical energy) will be in open condition and followed with that further 5 milliseconds hydrogen gas solenoid valve (12) will be in open condition. Hence the outlet of gas alternator has 100 millisecond flowed gas with 95 % AR and 5% H2, still the mixing has to be happen for this gases, so it directed to the mixing cylinder (4) by the set one bar pressure. Before switch on the alternator (4), vacuum pump (7) should be switched with two-way valve (6) opened for vacuum pump and gas mixing cylinder (5). It helps to vacuum the gases stored in the mixing cylinder (5). Once vacuum reaches to 10-1 bar pressure, vacuum pump set to switch off and two-way valve (6) should be closed, Pressure gauge (12) attached to the gas mixing cylinder help to know the pressure level in the mixing cylinder (5).
[0046] Once the gas alternator (4) switched on, then gas mixing cylinder start to fill and mixing the Argon and hydrogen gases. Once the gas pressure in gas mixing cylinder reaches to one bar level, mixing gas ready direct to the welding power source (9) by turned on the two-way valve (6) to welding power source (9). The flowmeter (8) attached in this line help to control the flow of gas to torch to get better welding quality. The welding power source (9) supply the current and gas required for ignition of arc on welding torch (10) at plate material (11).
ADVANTAGES OF THE INVENTION

[0047] The proposed system and method has the following advantages over the contemporary prior arts:

• Enhanced Weld Quality: Precise gas mixtures improve penetration, reduce porosity, and minimize spatter, leading to superior welds
• Customizable Gas Mixtures: Ability to mix gases like argon, hydrogen, helium, nitrogen, oxygen, and carbon dioxide in various proportions for diverse welding needs.
• Reduced Weld Defects: Precision in gas mixture composition helps mitigate common welding defects, particularly in sensitive materials.
• Increased Efficiency: On-demand gas mixing eliminates reliance on pre-mixed cylinders, ensuring efficient gas usage and reducing waste.
• Safety and Purity: A vacuum pump purges the mixing cylinder before new mixtures, ensuring purity and enhancing safety.
• User-Friendly Operation: Programmable timer-based flow valves allow for easy and precise gas mixture adjustments.
• Consistent Gas Supply: Flow meter and pressure gauges ensure a steady and controlled gas flow to the welding torch, crucial for stable arc and consistent welding results.

TEST RESULT:

ID No
(% H2 in AR) Macro Image Reinforcement (mm) Width (mm) Depth (mm)
1AF (0%) 3.914 1.883 0.502
1F
(1%) 5.817 1.536 0.636
2F
(2%) 6.839 1.133 1.461
3F
(5%) 6.932 1.182 1.833
4F
(7%) 6.746 1.210 3.123
5F
(10%) 6.995 1.210 1.275

[0048] The above table depicts the result of mixing of two different gases in GTAW welding in particular Hydrogen gas mixed with Argon up to 10% and welded with ER NiCr3 filler wire on carbon steel plate. The results prove that mixing of gas changes the penetration capacity.

[0049] The above description does not provide specific details of the manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0050] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other fixture or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0051] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0052] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different fixture or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
, Claims:We Claim:
1. A system for mixing shielding gases in gas tungsten arc welding (GTAW) process (100), the system (100) comprising:
a plurality of gas cylinders (1, 2) for storing different gases;
a plurality of gas Regulators (3) attached to each gas cylinder (1,2), configured to control the pressure of the gas exiting the cylinders (1,2);
a gas alternator (4) connected to the gas cylinders (1,2), equipped to control the gas flow, wherein the gas alternator (4) is provided with timer-based flow valves to control the amount of each gas by varying the gas flow duration to a single output;
a mixing cylinder (5) connected to the gas alternator for mixing the gases received from the gas alternator (4) and regulating the gas pressure;
a two-way flow valve (6) connecting the mixing cylinder (5) to regulate the flow of the gas;
a vacuum pump (7) connected to two-way flow valve (6) for evacuating the mixing cylinder (5) before starting a fresh gas mixture;
a flow meter (8) connected to the two-way flow valve (6) configured to control the flow rate of the gas;
a welding torch (10) provided in connection with the welding power source (9), to utilize the mixed gases for welding on a plate material (11); and
2. The system(100) as claimed in the claim 1,wherein a welding power source (9) is connected to the flow meter (8) for supplying the current to the system (100).
3. The system (100) as claimed in the claim 1, wherein a pressure gauge (12) is connected for monitoring the pressure levels in the gas cylinders and mixing cylinder.
4. The system (100) as claimed in the claim 1, wherein the gas alternator (4) is provided to open and close the flow valves in a sequence and duration corresponding to a desired ratio of gases in the final mixture.
5. The system (100) as claimed in the claim 1, wherein the gas alternator (4) comprises of at least two solenoid valves with respect to number of gases and one single gas outlets.
6. The system(100) as claimed in claim 1, wherein the shielding gas supply in different percentage is adjusted by turning the timer to on and off cycle of the solenoid valve control.
7. A method for mixing shielding gases for supply to ignite the arc in gas tungsten arc welding (GTAW), the method comprising:
setting a predetermined pressure in the gas cylinders (1,2) using the gas regulators (3);
setting the gas alternator (4) with specific time intervals corresponding to the desired percentage mix of each gas;
activating the vacuum pump (7) to evacuate the mixing cylinder (5) prior to introducing the gases;
initiating gas flow from the cylinders (1,2) to the gas alternator (4), wherein the gases are alternated based on the time intervals and directed to the mixing cylinder;
mixing of the gases in the mixing cylinder (5) at a predetermined pressure for a homogeneous blend; and
directing the mixed gas from the mixing cylinder (5) to the welding torch (10) through flowmeter (8).
8. The method as claimed in the claim 7, wherein at least two different shielding gases include argon, hydrogen, helium, Nitrogen, oxygen and carbon dioxide.