A method of cooling a liner in a plasma chamber. A recycle gas is contacted with or passed through the liner to cool the liner and pre-heat the recycle gas. The pre-heated gas is then recycled through the plasma chamber to become part of the plasma forming process. The method further comprises the liner is graphite, the recycle gas passes through at least one cooling channel present in the liner, at least one of the cooling channels are covered with at least one removable liner/channel cover, carbon deposits are formed from the presence of hydrocarbons in the recycle gas, at least one channel is formed in a spiral cooling channel pattern, at least one channel is formed in a substantially straight cooling channel pattern, and a plenum to aid in the production of an even distribution of cooling gas in the channels.

One embodiment is a cooling system for regulating temperature of a surface of a metallurgical furnace. The cooling system includes a plurality of spray conduits. Each spray conduit has one or more control valves and has a plurality of nozzles. A plurality of temperature sensors are disposed proximate the surface of the metallurgical furnace. A control system adjusts the control valves of the plurality of spray conduits in response to temperature information derived from the plurality of temperature sensors.

One embodiment is a cooling system for regulating temperature of a surface of a metallurgical furnace. The cooling system includes a plurality of spray conduits. Each spray conduit has one or more control valves and has a plurality of nozzles. A plurality of temperature sensors are disposed proximate the surface of the metallurgical furnace. A control system adjusts the control valves of the plurality of spray conduits in response to temperature information derived from the plurality of temperature sensors.

A cooling system to cool a surface of a tilting metallurgical furnace including an inner plate of the surface, a plurality of nozzles, and a drain manifold is disclosed. The inner plate has an external surface and an internal surface. The plurality of nozzles is configured to be fluidly connected to a coolant supply pipe. At least a first nozzle of the plurality of spray conduits is configured to spray coolant against the external surface of the inner plate. The drain manifold positioned to receive coolant from the external surface of the inner plate. At least a second nozzle of the plurality of nozzles is configured to spray coolant directly into the drain manifold.

A cooling system to cool a surface of a tilting metallurgical furnace including an inner plate of the surface, a plurality of nozzles, and a drain manifold is disclosed. The inner plate has an external surface and an internal surface. The plurality of nozzles is configured to be fluidly connected to a coolant supply pipe. At least a first nozzle of the plurality of spray conduits is configured to spray coolant against the external surface of the inner plate. The drain manifold positioned to receive coolant from the external surface of the inner plate. At least a second nozzle of the plurality of nozzles is configured to spray coolant directly into the drain manifold.

A control system for a vacuum arc remelting (VAR) process for a metal includes a direct current (DC) power source, a ram drive, voltage drip short sensor, and a controller, which includes a processor. The drip short sensor may be configured to measure a drip short frequency of the electric arc over a period of time. The controller is configured to determine a real time arc gap length between the electrode tip and the melt pool based on a correlation between the drip short frequency and arc gap length. The controller is further configured to control power input to the electrode by the DC power supply by determining an input power level to input to the electrode based on the real time arc gap length, the input power level configured to generate a desired arc gap length, by the DC power supply, at the input power level.

A control system for a vacuum arc remelting (VAR) process for a metal includes a direct current (DC) power source, a ram drive, voltage drip short sensor, and a controller, which includes a processor. The drip short sensor may be configured to measure a drip short frequency of the electric arc over a period of time. The controller is configured to determine a real time arc gap length between the electrode tip and the melt pool based on a correlation between the drip short frequency and arc gap length. The controller is further configured to control power input to the electrode by the DC power supply by determining an input power level to input to the electrode based on the real time arc gap length, the input power level configured to generate a desired arc gap length, by the DC power supply, at the input power level.

A solidifying device is for solidifying a substrate which includes a middle and two side portions. The thermostability of the middle portion is greater than that of the side portions. The solidifying device includes a housing, a heating member, a temperature control air-floating member and a conveyor. The housing defines a working space. The heating member is in the working space. The substrate has a heat receiving surface facing the heating member. The temperature control air-floating member is in the working space and below the heating member. The conveyor is for transporting the substrate into the working space and between the temperature control air-floating member and the heating member. The heating member is for providing heat to the substrate. The temperature control air-floating member is for supplying air towards the substrate to allow the substrate to float in the working space and form a high-temperature and two low-temperature areas.

A solidifying device is for solidifying a substrate which includes a middle and two side portions. The thermostability of the middle portion is greater than that of the side portions. The solidifying device includes a housing, a heating member, a temperature control air-floating member and a conveyor. The housing defines a working space. The heating member is in the working space. The substrate has a heat receiving surface facing the heating member. The temperature control air-floating member is in the working space and below the heating member. The conveyor is for transporting the substrate into the working space and between the temperature control air-floating member and the heating member. The heating member is for providing heat to the substrate. The temperature control air-floating member is for supplying air towards the substrate to allow the substrate to float in the working space and form a high-temperature and two low-temperature areas.

A high temperature vacuum furnace including a prefabricated tongue-and-groove, low-mass insulation ring assembly hot zone, resulting in decreased energy costs and increased energy efficiency, faster heating and cooling cycles, and expedited maintenance capability resulting in lower maintenance costs. Decreased time of a workpiece in the furnace improves production turnaround and lowers energy costs for each heat treating cycle. Furnace manufacturing is also easier and less expensive compared to prior art vacuum furnaces. A bottom support structure replaces the prior art metal support ring resulting in an approximately 80-85% weight saving in the furnace hot zone. This reduces the time and energy required to heat and cool the furnace components and workpiece.