Torch

Abstract: An atmospheric low-temperature microwave plasma torch has been developed and applied to disinfection. The size of the plasma output is relatively large (35 mm in diameter). Ar gas at a flow rate of 2.2 slm and 85 W microwave power are used. Plasma discharges are produced between the tip of each electrode and the inner surface of the cylinder. When an Escherichia coli culture is placed for 2 min at 20 mm below the torch, where the gas temperature is sufficiently cool, the bacteria are almost completely killed within a 40 mm diameter circle. The UV radiation is one of the major players responsible for killing bacteria, others being the reactive species and the charged particles.

Abstract: A plasma arc torch with improved sealing of connections between fluid passages of adjoining parts of the torch, means for reducing current leakage through a control fluid, and an improved pilot arc electrical assembly, includes a main torch body and an insulator body which abut and each of which has a plasma gas passage and a control fluid passage which extend to the abutting end faces of the bodies and are aligned thereat Connections between the aligned plasma gas passages are made via coupling tubes each having a first portion inserted into a receiving portion of the passage in the main torch body and a second portion inserted into a receiving portion of the passage in the insulator body Each inserted portion includes a pair of O-rings spaced apart along the length of the tube for sealing the connection An elongate insulating conduit is sealingly received within the control fluid passages of the insulator body and main torch body, and extends through the main torch body into a control fluid connector tube A pilot arc electrical assembly includes an electrical connector attached to an end of a pilot arc bus wire and received in a receptacle in the insulator body, and a contact screw which extends through a contact ring at the outer end of the insulator body into the receptacle and engaging the connector

Abstract: A tool-workpiece instructional system is provided for simulating operation on a workpiece in the form of a welding site as shown on a display, by a student using a tool such as a welding torch simulator. The torch is a mock-up of as real torch, having mock values and torch tip, but is not supplied with any gas. A light pen and mercury switches are mounted inside to detect torch position and angular position relative to the display. A computer with a control program uses information regarding parameters of torch location relative to the display, including torch angle, torch distance to the display, torch position as projected on the plane of the display, welding rod position (as detected by a touch screen on top of the display) and oxygen and acetylene valve positions of the welding torch, and uses the parameters to determine what would happen to a welding site during a real weld and addresses appropriate segments in a video disc player to display a simulation of the welding site in real time.

Abstract: An induction plasma torch comprises a tubular torch body, a gas distributor head located at the proximal end of the torch body for supplying at least one gaseous substance into the chamber within the torch body, a higher frequency power supply connected to a first induction coil mounted coaxial to the tubular torch body, a lower frequency solid state power supply connected to a plurality of second induction coils mounted coaxial to the tubular torch body between the first induction coil and the distal end of this torch body. The first induction coil provides the inductive energy necessary to ignite the gaseous substance to form a plasma. The second induction coils provide the working energy necessary to operate the plasma torch. The second induction coils can be connected to the solid state power supply in series and/or in parallel to match the impedance of this solid state power supply.