Patent Application
20150014291
The present invention generally relates to the field of fume collection, and more specifically to a system and method for collection of fumes from a welding torch as it travels up into the atmosphere before it disburses away from the capture area.
Welding fumes include many metallic particles that can be hazardous to the health of people. In addition, particle fallout from the welding fumes can be deposited around a factory or work area in the form of dust. It would be desirable to avoid one or both of these conditions. One possible solution is to scrub the air with a large air handling system, however this can only start after the fumes are disbursed around the factory or work area and it can be cost prohibitive. Alternatively, a high volume vacuum at the end of the welding torch can be used to collect the fumes; however this vacuum can also collect the shield gas needed for the welding process and cause weld defects. The vacuum at the nozzle can be turned off at points of the welding process but this allows the welding fumes to go uncollected. Source capture of welding fumes can also interfere with the product being welded which can require changing the welding procedure or reprogramming of a welding robot. Programming a long cycle welding robot can involve many hours of writing code for the arm movement. A rigid fume collector added to an arm that is already programmed can require a significant amount of reprogramming.
It would be desirable to collect the welding fumes near the welding torch before they are disbursed around the factory or work area without interfering with the welding process in a way that causes weld defects or that requires changing a welding procedure or reprogramming a welding robot.
A flexible welding fume collector is disclosed for a welding process that uses a welding torch having a nozzle. The welding fume collector includes a flexible sheath, a fume collection opening and a vacuum hose coupled to a vacuum system. The flexible sheath is made of a flexible material, and has a proximal end and a distal end. The welding torch extends through the flexible sheath with the nozzle of the welding torch extending beyond the distal end of the flexible sheath. The fume collection opening is at the distal end of the flexible sheath. The vacuum hose is coupled to a vacuum system, and the vacuum hose extends into the proximal end of the flexible sheath. The vacuum system creates a negative pressure inside the flexible sheath which extends out through the fume collection opening to collect welding fumes.
The fume collection opening can have a generally elliptical shape. In a flexible welding fume collector with a generally elliptical-shaped fume collection opening, the major axis can extend along the welding direction and the minor axis perpendicular to the welding direction; and/or the major and minor axes can both pass through the nozzle of the welding torch. In a flexible welding fume collector with a generally elliptical-shaped fume collection opening, exemplary dimensions of the major and minor axes can be about 46 millimeters and 36 millimeters, respectively.
The flexible sheath can be made of rubber, silicone or other flexible materials, and the flexible material can be heat resistant. The vacuum system, vacuum hose and flexible sheath can be sized to create the desired vacuum to collect the welding fumes without interfering with the welding process. The fume collection opening can be positioned in the recompression area of the welding fumes. The diameter of the vacuum hose and the diameter of the flexible sheath can be sized to create a low-speed collection of welding fumes through the fume collection opening. The welding torch can extend through substantially the center of the fume collection opening. The fume collection opening can be positioned far enough above the nozzle of the welding torch to avoid collection of shield gas where recompression of the welding fumes occurs. The fume collection opening can be significantly larger than the nozzle of the welding torch.
The vacuum system can include a self-cleaning filter system for collecting the welding fumes. The welding system can be a robotic welding system.
For the purposes of promoting an understanding of the principles of the novel invention, reference will now be made to the embodiments described herein and illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the novel invention is thereby intended, such alterations and further modifications in the illustrated devices and methods, and such further applications of the principles of the novel invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the novel invention relates.
A welding fume collector can be positioned near the welding torch to collect the fumes before being disbursed throughout the work area. The fume collector can be used for robotic welding in a factory and in other situations. The collector can be designed to capture fumes as they travel up into the atmosphere before they disburse away from the capture area.
The fume collector can be made of a flexible material that holds its original shape for collection and deforms or collapses when pressed against or colliding with a product allowing the welding process to continue, and retakes its original shape when not pressed against or colliding with a product. The flexible fume collector can be made of, for example and not by way of limitation, a non-heat-resistant rubber material or a heat-resistant high temperature silicone, for example silicone designed for lining ovens. The heat-resistance of the material is not critical because the vacuum provides a cooling process. The original shape of the flexible fume collector can be an elliptical shape. A numerical or digital control can be used to control the shape of the collector, for example to align the major axis of an elliptical-shaped collector with the direction of the welding. A mold can be used to form the flexible fume collector. A flexible fume collector can be added to an existing robotic welding system with little or no requirement for reprogramming.
The welding fume collector 100 should be positioned above the welding arc far enough to avoid collection of the shield gas where the recompression of the fumes occurs. The collector 100 creates a vacuum or low pressure collection area 110 where the welding fumes are collected. The low pressure evenly collects the fumes into the fume collection opening 108. The welding fume collector 100 can be coupled to the welding nozzle 132 to allow the fume collection opening 108 to be in the recompression area. The welding fume collector 100 can be positioned to take advantage of the fluid flow of the fumes.
This welding fume collector 100 can have a generally oval or elliptical collector opening 108 with the longer major axis extending along the welding direction in front and behind the welding arc and the shorter minor axis being perpendicular to the welding direction. The vacuum can be introduced to the flexible sheath 102 through a significantly smaller vacuum hose 140 at a high pressure and volume. When the collector opening 108 is significantly larger than the vacuum hose 140, there will be a significant pressure drop at the collector opening 108 allowing for a low speed collection of the welding fumes. A high volume vacuum at the end of a welding torch can cause welding defects if in the process of capturing the welding fumes it also collects the shield gas needed for the welding process. This can be avoided by using a welding fume collector with a collector opening that is significantly larger than the size of the shield gas nozzle, for example a hundred times the size of the shield gas nozzle 132. This allows the welding process to be successful without introducing weld defects while the collector is collecting welding fumes.
The vacuum or low pressure is introduced at the proximal end 104 of the flexible sheath 102 by the vacuum hose 140. Having a larger cross-section for the flexible sheath 102 than for the vacuum hose 140 produces a lower pressure collection of the welding fumes through the collection opening 108 of the flexible sheath 102. The welding nozzle 132 can be substantially in the center of the cross-section for the flexible sheath 102. When the welding process melts the steel or other material 120 through the nozzle 132, welding fumes are generated. The pressure from the shielding gas forces the fumes away from the welding area. The fume collector opening 108 of the collector 100 can be positioned far enough away from the welding area to allow the inertia of the shield gas to be dissipated allowing the collection of the welding fumes to be more effective.
The welding fume collector 100 sucks the welding fumes through the fume collection opening 108 up through the vacuum hose 140 where it passes through filters to remove particles and other components of the welding fumes. The vacuum level through the vacuum hose 140 and the fume collection opening 108 drops over the life of these filters as they fill up with debris. A self cleaning filter system can help alleviate this vacuum reduction issue as the welding fume typically includes very small particles.
While exemplary embodiments incorporating the principles of the present invention have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
