A method for providing a region of inert gas around the electrodes in an electric arc furnace is provided. This electric arc furnace includes consumable graphite electrodes, a melting zone, and at least one lance including an inlet and an outlet, wherein the inlet is connected to a liquid inert fluid source. The method includes introducing the consumable graphite electrodes into the melting zone, wherein the distal ends of the electrodes form arcs with a solid charge of scrap metal. The method also includes introducing the liquid inert fluid into the inlet end of the at least one lance, wherein the inert fluid exits the outlet end and is introduced into the melting zone proximate to the distal ends of the electrodes, thereby providing an inert gaseous blanket, once the liquid vaporizes, around the distal ends of the electrodes

This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U.sub.0; a DC to DC switching converter having a switching frequency f.sub.s; a current control loop having a latency ; and, a ballast inductor having an inductance L; characterized in that inductance L is such that

[00001]$L>\left(\frac{U_0}{1.Math.5.Math.0.Math.0}\right).Math.,\mathrm{and}.Math..Math.L<\frac{1}{f_s}.Math.\left(\frac{U_0}{2.Math.0.Math.0}\right).$

Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch.

Embodiments described herein generally relate to plasma assisted or plasma enhanced processing chambers. More specifically, embodiments herein relate to electrostatic chucking (ESC) substrate supports configured to provide pulsed DC voltage, and methods of applying a pulsed DC voltage, to a substrate during plasma assisted or plasma enhanced semiconductor manufacturing processes.

This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U.sub.0; a DC to DC switching converter having a switching frequency f.sub.S; a current control loop having a latency Formula (I); and, a ballast inductor having an inductance L; characterized in that inductance L is such that Formula (II) and Formula (III). Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch. $\begin{array}{cc};& \left(I\right)\\ L>\left(\frac{U_0}{1500}\right),& \left(\mathrm{II}\right)\\ L<\frac{1}{f_s}\left(\frac{U_0}{200}\right).& \left(\mathrm{III}\right)\end{array}$

An electrical discharge, suitable for heating optical fibers for processing, is made in a controlled partial vacuum, such that saturation of available ionizable gas molecules is reached. The workpiece temperature is thereby made to be a stably controlled function of the absolute air pressure and is insensitive to other conditions. A system and method accomplishing the foregoing are provided.

A plasma heater includes a plasma heating section, an exhaust wasteheat heating section, a gas circulation pump, a water cooling system, and a treatment tank for waste gas and waste water. Flames emitted by plasma torches of plasma generators are directly sprayed onto first water pipes for heating. Exhaust generated after combustion of the plasma torches flows through the tail gas residual heat heating section in the metal cylindrical casing, then flows out of the metal cylindrical casing to enter the gas circulation pump, and flows back into the plasma generators through the gas circulation pump for recycling. After the circulating exhaust operates for more than 10 minutes, the discharged waste gas and waste liquid enter the recovering treatment tank.

Embodiments described herein generally relate to plasma assisted or plasma enhanced processing chambers. More specifically, embodiments herein relate to electrostatic chucking (ESC) substrate supports configured to provide pulsed DC voltage, and methods of applying a pulsed DC voltage, to a substrate during plasma assisted or plasma enhanced semiconductor manufacturing processes.

A plasma heater includes a plasma heating section, an exhaust wasteheat heating section, a gas circulation pump, a water cooling system, and a treatment tank for waste gas and waste water. Flames emitted by plasma torches of plasma generators are directly sprayed onto first water pipes for heating. Exhaust generated after combustion of the plasma torches flows through the tail gas residual heat heating section in the metal cylindrical casing, then flows out of the metal cylindrical casing to enter the gas circulation pump, and flows back into the plasma generators through the gas circulation pump for recycling. After the circulating exhaust operates for more than 10 minutes, the discharged waste gas and waste liquid enter the recovering treatment tank.

This invention concerns power supplies suitable for electric arc gas heaters such a plasma torches. It more particularly relates to the dimensioning of the inductor in the switched-mode DC to DC converter used for feeding the torch. The invention concerns in particular a DC power supply for driving a non-transferred electric arc gas heater, comprising: an AC to DC rectifier providing a potential U.sub.0; a DC to DC switching converter having a switching frequency f.sub.S; a current control loop having a latency Formula (I); and, a ballast inductor having an inductance L; characterized in that inductance L is such that Formula (II) and Formula (III). Such a design ensures the stability of the current control loop, while also ensuring a sufficient amount of current ripple to spread out the erosion zone on the electrodes of the torch.

[00001]$\begin{array}{cc};& \left(I\right)\\ L>\left(\frac{U_0}{1500}\right).Math.,& \left(\mathrm{II}\right)\\ L<\frac{1}{f_s}.Math.\left(\frac{U_0}{200}\right).& \left(\mathrm{III}\right)\end{array}$

A friction stir welding method for bonding a to-be bonded material, includes: a step of supplying nitrogen and introducing nitrogen into the to-be bonded material while melting the to-be bonded material; and a step of friction stir welding a portion of the non-bonded material in which the nitrogen is introduced. A friction stirring device for bonding a to-be bonded material, includes: a heating source for melting the to-be bonded material; a nitrogen supply source for supplying nitrogen to a melted portion of the to-be bonded material and introducing nitrogen into the to-be bonded material; and a friction stir tool for friction stir welding a portion of the non-bonded material in which the nitrogen is introduced.