A center pipe is used in a plasma torch including a base portion and an electrode to supply cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body has a tube-like shape with a cooling water channel therein. The pipe body is electrically conductive and configured to be electrically connected to an external power source via the base portion. The contact piece is arranged radially outside the pipe body at an intermediate position between a base end surface and a tip end surface of the pipe body. The contact piece is electrically conductive and energizes the electrode through contact with an internal circumferential surface of the electrode. The base end surface is disposed outside the electrode when the center pipe is inserted into the electrode. The pipe body is configured to be electrically connected to the electrode via the contact piece.

A center pipe is used in a plasma torch including a base portion and an electrode to supply cooling water into the electrode. The center pipe includes a pipe body and a contact piece. The pipe body has a tube-like shape with a cooling water channel therein. The pipe body is electrically conductive and configured to be electrically connected to an external power source via the base portion. The contact piece is arranged radially outside the pipe body at an intermediate position between a base end surface and a tip end surface of the pipe body. The contact piece is electrically conductive and energizes the electrode through contact with an internal circumferential surface of the electrode. The base end surface is disposed outside the electrode when the center pipe is inserted into the electrode. The pipe body is configured to be electrically connected to the electrode via the contact piece.

Atmospheric-pressure plasma generation device 10 of the present invention includes heat sinks 27 and 28. Flow paths are formed in the heat sinks, and cooling gas flows in the flow paths, thereby cooling lower housing 20 in which a reaction chamber is formed. Here, the gas used for cooling is warmed by the heat of the lower housing. The warmed gas is supplied into heated gas supply device 14 and heated by heater 112. The heated gas flows in lower cover 22 and is emitted together with plasma gas from lower cover 22 toward a processing object. Consequently, it is possible to perform cooling of the lower housing heated by electric discharge and perform heating of the processing object, and it is possible to reduce energy required for heating gas.

Plasma spray apparatus for coating substrates, including at least a working chamber including a plasma torch and at least a substrate support, in which an inert gas or a mixture of inert gases is contained at a pressure which is close to the normal pressure, and at least a gas circuit, in communication with said working chamber, including recirculating means of the inert gases contained in said working chamber. The recirculating means include a closed loop, including a blower and a first heat exchanger communicating with said working chamber for extracting the inert gases and supplying a first fraction of the cooled inert gases back into a first portion of the working chamber, and at least a path, communicating with said closed loop and including a compressor and a second heat exchanger for supplying a second fraction of the cooled inert gases into a second portion of the working chamber.

Plasma spray apparatus for coating substrates, including at least a working chamber including a plasma torch and at least a substrate support, in which an inert gas or a mixture of inert gases is contained at a pressure which is close to the normal pressure, and at least a gas circuit, in communication with said working chamber, including recirculating means of the inert gases contained in said working chamber. The recirculating means include a closed loop, including a blower and a first heat exchanger communicating with said working chamber for extracting the inert gases and supplying a first fraction of the cooled inert gases back into a first portion of the working chamber, and at least a path, communicating with said closed loop and including a compressor and a second heat exchanger for supplying a second fraction of the cooled inert gases into a second portion of the working chamber.

A plasma generation device includes a plasma head configured to eject plasma gas that is plasmatized, a gas supply device configured to supply gas serving as the plasma gas to the plasma head, a pair of electrodes that is provided in the plasma head, the pair of electrodes being configured to perform discharging for a part of the gas supplied from the gas supply device to generate the plasma gas, a temperature sensor that is provided in the plasma head, the temperature sensor being configured to measure a temperature of the plasma head; and a control device, in which the control device executes a cooling process of cooling the plasma head by causing the gas supply device to continue supply of the gas until the temperature sensor measures a temperature equal to or less than a predetermined value after the discharging of the pair of electrodes is stopped.

A plasma processing apparatus includes a cooling plate having a fixing surface to which an upper electrode is fixed, the cooling plate having, on the fixing surface, an electrostatic chuck configured to attract the upper electrode by an attraction force generated by an applied voltage; a power supply configured to apply the voltage to the electrostatic chuck; and a power supply controller configured to control the power supply such that an absolute value of the voltage applied to the electrostatic chuck is increased based on a degree of consumption of the upper electrode.

A plasma processing apparatus includes a cooling plate having a fixing surface to which an upper electrode is fixed, the cooling plate having, on the fixing surface, an electrostatic chuck configured to attract the upper electrode by an attraction force generated by an applied voltage; a power supply configured to apply the voltage to the electrostatic chuck; and a power supply controller configured to control the power supply such that an absolute value of the voltage applied to the electrostatic chuck is increased based on a degree of consumption of the upper electrode.

A contact start liquid-cooled plasma arc cutting torch is provided that includes a translatable liquid-cooled electrode, a nozzle, and a multi-piece cathode. The electrode comprises an electrode body defining a proximal end and a distal end along a longitudinal axis of the electrode body. The electrode body includes a coolant cavity configured to receive at least a portion of a coolant tube of the torch for directing a liquid coolant flow distally through the coolant tube within the coolant cavity. The cathode is disposed about the proximal end of the electrode body and includes a first body shaped to matingly engage the electrode and a second body shaped to matingly engage the torch. The first body slidingly engages the second body such that the first body and the electrode are axially translatable relative to the second body along the longitudinal axis.

A contact start liquid-cooled plasma arc cutting torch is provided that includes a translatable liquid-cooled electrode, a nozzle, and a multi-piece cathode. The electrode comprises an electrode body defining a proximal end and a distal end along a longitudinal axis of the electrode body. The electrode body includes a coolant cavity configured to receive at least a portion of a coolant tube of the torch for directing a liquid coolant flow distally through the coolant tube within the coolant cavity. The cathode is disposed about the proximal end of the electrode body and includes a first body shaped to matingly engage the electrode and a second body shaped to matingly engage the torch. The first body slidingly engages the second body such that the first body and the electrode are axially translatable relative to the second body along the longitudinal axis.