Light blocking and dust removal isolation method for gas shielded welding

Abstract

The present application relates to the pollution prevention technical field of gas shield welding;With the dry water containing 93%-95% of water content and 3%-7% of fumed silica as the isolation medium, the isolation medium is sprayed from the nozzle to the recovery port during the operation of the welding gun, forming an isolation curtain wall;The present application uses dry water as the isolation medium, and the movement between the nozzle and the recovery port forms a dynamic isolation curtain wall, and then through the complex gas-liquid interface of the dry water particles and the adsorption effect of the fumed silica in the gas phase, the pollution of visible light, ultraviolet light and dust in the gas shield welding process is realized, and the static mask equipment has better applicability and process flexibility.

Description

Technical Field

[0001] This invention relates to the field of pollution prevention and control technology for gas shielded welding. Background Technology

[0002] Gas shielded welding is a fusion welding process that uses a high-temperature electric arc as a heat source. Since the temperature at the center of the arc is higher than the boiling point of most welding materials, it generates serious visible light and ultraviolet light pollution during operation, as well as dust pollution caused by the vaporization and condensation of welding materials, resulting in a harsh production and working environment.

[0003] Regarding pollution prevention in welding, common solutions for metal dust include exhaust filtration and local environmental sealing for settling. However, due to the characteristic of gas shielded welding using inert gas to protect the weld pool, local environmental sealing can easily cause oxygen deficiency and suffocation for operators, posing a safety hazard and making it unsuitable. In addition, in the exhaust filtration solution, in order to ensure the protective effect of the inert gas, the welding operation area needs to be sheltered from the wind and have reduced airflow, so it is not suitable to use a gas collection hood. Only the exhaust ventilation filtration method in the production workshop can be used, which has a very poor dust protection effect in the production workshop. It is usually only used for environmental protection purposes and has no substantial effect on the occupational protection of workers.

[0004] There is currently no effective way to prevent and control electric arc light pollution. Protective goggles and UV-protective clothing cannot completely eliminate the threat to worker safety posed by strong electric arc light and ultraviolet light. Summary of the Invention

[0005] Therefore, it is necessary to design a dynamic shading and dust removal isolation scheme that operates synchronously with the welding torch to optimize the working environment of gas shielded welding operations.

[0006] A light-blocking and dust-removing isolation method for gas shielded welding, characterized in that: 1) A nozzle is set on the side of the welding torch, and an isolation medium recovery port that moves with the welding torch is set on the workpiece; 2) Dry water with a moisture content of 93%-95% by mass and a fumed silica content of 3%-7% by mass is used as the isolation medium. When the welding torch is working, the isolation medium is sprayed from the nozzle to the recovery port to form an isolation curtain.

[0007] In the above scheme, the spraying of the isolation medium is linked to the welding torch, starting and stopping synchronously with the torch. During operation, the isolation medium forms a dynamic isolation curtain with a thickness of 5-10mm between the nozzle and the recovery port, achieving the functions of light blocking, dust removal, and isolation. In non-operational mode, the nozzle is inactive, and the isolation curtain remains open, facilitating observation and process adjustments by operators.

[0008] In terms of dealing with visible and ultraviolet light pollution, the light pollution caused by electric arcs is continuously diffusely reflected by the silica on the surface of dry water particles inside the dynamic isolation curtain wall, and then absorbed and weakened by the water inside the particles, thus achieving isolation and shielding. Compared with continuous water curtain shielding, the curtain wall is formed by dynamic particles, and its water / air interface is complex, which can greatly increase the path of light transmission through the curtain wall, thus more effectively absorbing and shielding light pollution.

[0009] In terms of dust pollution control, silica has a large specific surface area, which can efficiently adsorb the fine particles formed by the vaporization and condensation of welding materials. After adsorption, the particles move with the dry water and are wetted and wrapped by the water during the collision and vibration of the dry water particles. They are then collected by the recycling port for subsequent treatment. This solution can effectively remove welding dust formed by the vaporization of welding materials, protecting workers during welding operations.

[0010] Meanwhile, regarding noise pollution, this solution involves dry water particles colliding with each other as sound waves pass through, converting some of the sound wave energy into the kinetic energy of the dry water particles. In the case where the isolation medium impacts the surface of the weldment and is then collected by the recovery port, the vibration energy of the weldment can also be converted into particle kinetic energy by the isolation medium that impacts and contacts the weldment. Therefore, it can achieve a certain noise reduction effect. However, this solution has no absorption effect on noise transmitted along the inside of large-sized weldments or noise on the back side of the weldment. The noise reduction effect has a large directional difference and is limited.

[0011] In the above scheme, the absorption of light pollution is entirely achieved by water bodies. Since the absorption rate of ultraviolet light by water bodies is much lower than that of visible light, the above scheme is less effective in preventing and controlling ultraviolet light pollution than in preventing and controlling visible light pollution.

[0012] For this reason, this case provides an improved solution to enhance the prevention and control of ultraviolet (UV) pollution. Preferably, the isolation medium also includes a dye or water-soluble absorbent at a mass ratio of no more than 0.5%. In this improved solution, adding a dye such as a fluorescent dye allows the dye to adsorb onto the surface of silica, increasing the absorption and isolation effect of UV light outside the water body during continuous diffuse reflection of UV light. Adding a water-soluble absorbent such as dihydroxybenzophenone allows the absorbent to dissolve in the water body, increasing the absorption and isolation effect of the water body itself on UV light. Since the adsorption of the dye on the silica surface affects the adsorption effect on dust, and the water-soluble absorbent affects the hydrophobic agglomeration of silica and the formation of dry water particles in the water body, the amount of dye or water-soluble absorbent added needs to be adjusted and limited according to the mass ratio of silica and the type of additive, and is generally no more than 0.5% by mass.

[0013] Preferably, the nozzle points inward to the recovery port, and the isolation medium is collected by the recovery port after impacting the surface of the weldment. This solution is suitable for processing flat-shaped plates, and the seamless connection between the barrier formed by the isolation medium and the weldment further improves the dust removal effect.

[0014] Furthermore, the isolation medium also includes precipitated silica at a mass ratio of no more than 2%. Precipitated silica particles are larger than fumed silica particles and are usually used as abrasives. They also participate in dry water agglomeration and bind to the water body due to their hydrophobic characteristics. In this scheme, when dry water particles impact the surface of the weldment, the abrasive properties of precipitated silica can scrape off impurities such as oil film adhering to the surface of the weldment, thereby improving the welding quality.

[0015] Preferably, the nozzle also includes a constriction device, which is used to compress the isolation medium at the nozzle, causing the isolation medium to diffuse in a fan shape between the nozzle and the recovery port, thereby increasing the curtain wall area formed by a single nozzle. Furthermore, to prevent the constriction device from directly contacting dry water particles and causing adhesion, which would affect the formation of the curtain wall, the constriction device is equipped with a heater. This heater is used to maintain the temperature of the constriction device above 260 degrees Celsius during operation, preventing direct contact between dry water particles and the constriction device through the Leidenfrost effect.

[0016] Preferably, the actuation mechanism for spraying the isolation medium from the nozzle is a centrifugal device. Compared with pneumatic spraying, this solution has a larger flow rate of isolation medium, preventing the formation of holes in the curtain wall that cause light and air leakage. At the same time, the spraying speed of the isolation medium is more uniform, preventing slag from falling from the nozzle.

[0017] This invention uses dry water as an isolation medium, and the movement between the nozzle and the recovery port forms a dynamic isolation curtain. Then, through the complex gas-liquid interface of dry water particles and the adsorption effect of fumed silica, it can control the pollution of visible light, ultraviolet light and dust in the gas shielded welding process. Compared with static shielding equipment, it has better applicability and process flexibility. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the principle of a specific embodiment of a light-blocking and dust-removing isolation method for gas shielded welding.

[0019] In the diagram: Nozzle 1, Centrifuge 2, Recovery port 3, Welding torch 4, Isolation curtain wall 5, Static isolation plate 6, Closure device 7. Detailed Implementation

[0020] The existing equipment or simple modifications required for implementation include nozzle 1, centrifuge 2, recovery port 3, and negative pressure fan. Nozzle 1 is installed on welding torch 4 and connected to centrifuge 2 to supply the isolation medium. Recovery port 3 is connected to negative pressure fan, allowing the isolation medium to be drawn away by the fan. In operation, the isolation medium forms a 5-10mm thick dynamic isolation curtain 5 between nozzle 1 and recovery port 3. Isolation curtain 5, acting alone, shields the welding torch weld, or it can be combined with static isolation plate 6 to form an isolation cover shielding the weld. This isolation curtain 5 provides light-blocking and dust-removing isolation. In non-operational mode, nozzle 1 is inactive, and isolation curtain 5 is open, facilitating observation and process adjustments by operators.

[0021] The nozzle device 7 is an electrically heated metal tube with a specific shape that is adjusted according to the shape requirements of the isolation curtain wall 5. It is installed on the inner wall of the nozzle 1 and its temperature is higher than 260 degrees Celsius when in operation.

[0022] The isolation medium is formed by thoroughly mixing a mixture of water (93-95%), fumed silica (3-7%), precipitated silica (0-2%), and a dye or water-soluble absorbent (0-0.5%) to create granular dry water. According to static isolation curtain wall simulation tests, smaller dry water particle sizes result in better absorption and isolation of light, dust, and noise. However, according to dynamic isolation curtain wall forming tests, smaller dry water particle sizes are more prone to nozzle shedding and curtain wall breakage. Therefore, the actual particle size of the dry water formed by mixing and granulation needs to be determined based on the selected nozzle, spray speed, and other application environment conditions, and suitable particle size data should be obtained through field testing.

[0023] In the mixing ratio of the isolation medium, precipitated silica is selected. It is applicable to the structural scheme in which the isolation medium impacts the welding material and is then received by the recycling port. In this case, precipitated silica, as an abrasive adhering to the water particles, can effectively scrape off impurities such as oil film on the surface of the weldment and improve the process performance.

[0024] Dyeing agents or water-soluble absorbents are selected, which can improve the absorption effect of visible light and ultraviolet light in this design, but have a negative effect on the formation of isolation medium particles and dust removal.

Claims

1. A light-blocking and dust-removing isolation method for gas shielded welding, characterized in that: 1) A nozzle is set on the side of the welding torch, and an isolation medium recovery port that moves with the welding torch is set on the workpiece; 2) Dry water with a moisture content of 93%-95% by mass and a fumed silica content of 3%-7% by mass is used as the isolation medium. When the welding torch is working, the isolation medium is sprayed from the nozzle to the recovery port to form an isolation curtain. The nozzle also includes a nozzle constriction device, which is used to compress the isolation medium at the nozzle, causing the isolation medium to diffuse in a fan shape between the nozzle and the recovery port. The closure device is equipped with a heater, which is used to maintain the temperature of the closure device above 260 degrees Celsius during operation.

2. The light-blocking and dust-removing isolation method for gas shielded welding as described in claim 1, characterized in that, The isolation medium also includes a dye or water-soluble absorbent at a mass ratio of no more than 0.5%.

3. The light-blocking and dust-removing isolation method for gas shielded welding as described in claim 1, characterized in that, The nozzle points inward to the recovery port, and the isolation medium is received by the recovery port after impacting the surface of the weldment.

4. The light-blocking and dust-removing isolation method for gas shielded welding as described in claim 3, characterized in that, The isolation medium also includes precipitated silica at a mass ratio of no more than 2%.

5. The light-blocking and dust-removing isolation method for gas shielded welding as described in claim 1, characterized in that, The mechanism for spraying the isolation medium from the nozzle is a centrifugal device.

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