US 2026/0025903 A1Published application

Apparatus and methods for purging cooling liquid conduits in a plasma arc torch

OwnerAndrew John Raymondinventor

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Abstract

Plasma arc cutting assemblies and methods that facilitate the purging of liquid from a cooling system that functions to cool components of a torch during a cutting operation. One aspect includes delivering a process gas into the cooling system to purge from it the liquid coolant. This is achieved by coupling a process gas source with a coolant supply conduit and delivering process gas into the coolant supply conduit through one or more control valves situated between the process gas source and the coolant supply conduit. Process gas from the gas source may be simultaneously delivered into a process gas flow channel of the torch during the purging process. Monitoring a liquid coolant level in a storage tank into which the liquid coolant flows may occur during the purging process, with an automatic closing of the one or more control valves occurring when a high liquid coolant level is detected.

Claims20

Dependent claims

A plasma arc cutting assembly comprising:

a torch configured to be outfitted with a detachable consumable part having disposed therein a coolant channel through which a liquid coolant flows during a plasma arc cutting operation and a process gas flow channel that is configured to deliver a process gas into an arc chamber of the torch to maintain a stream of plasma;
a coolant supply conduit through which the liquid coolant is delivered to the coolant channel;
a coolant return conduit through which the liquid coolant flows upon exiting the coolant channel;
a first control valve located on a gas line that extends at least partially between a process gas source and the process gas flow channel of the torch, the first control valve being configured to control flow of process gas into the process gas flow channel, the gas line including a first conduit located downstream an outlet of the first control valve;
and
a second control valve located between a second conduit and a third conduit and being transitional between an open position and a closed position, the second conduit coupling the first conduit to an inlet of the second control valve, the third conduit coupling an outlet of the second control valve to the coolant supply conduit.

3 more elements

A plasma arc cutting assembly comprising:

a torch configured to be outfitted with a detachable consumable part having disposed therein a coolant channel through which a liquid coolant flows during a plasma arc cutting operation and a process gas flow channel that is configured to deliver a process gas into an arc chamber of the torch to maintain a stream of plasma;
a coolant supply conduit through which the liquid coolant is delivered to the coolant channel;
a coolant return conduit through which the liquid coolant flows upon exiting the coolant channel;
a pressurized plasma process gas source containing the process gas;
a gas line through which the process gas flows before entering the process gas flow channel, a first control valve being disposed on the gas line and configured to control a flow of process gas into the process gas flow channel;
a first conduit and a second conduit, wherein a second control valve that is transitional between an open position and a closed position is disposed between the first conduit and the second conduit, and the second conduit couples an outlet of the second control valve to the coolant supply conduit;
a tank containing the liquid coolant, the tank including a liquid coolant outlet in fluid communication with the coolant supply conduit;
and
a liquid coolant high level sensor coupled to or residing in the tank and configured to activate a switch upon a liquid coolant level in the tank achieving a high threshold level, wherein when activated, the switch is operative to cause to the second control valve to cease the flow of process gas into the coolant supply conduit.

6 more elements

A method of purging liquid coolant from a plasma arc cutting assembly, the plasma arc cutting assembly comprising:

terminating power to a liquid coolant pump configured to pump, via a coolant supply conduit, a liquid coolant to a torch configured to be outfitted with a detachable consumable part that includes a coolant channel through which the liquid coolant flows during a plasma arc cutting operation and a process gas flow channel that is configured to deliver a process gas into an arc chamber of the torch to maintain a stream of plasma;
causing a first control valve, which is located on a gas line extending at least partially between a process gas source and the process gas flow channel, to assume an open position;
causing a second control valve, which is located on a conduit between the gas line and the coolant supply conduit to assume an open position, wherein when the first control valve and the second control valve are each in their open position, the process gas is delivered into at least the coolant supply conduit and the coolant channel to remove the liquid therefrom;
and
while purging the liquid coolant from the plasma arc cutting assembly, simultaneously delivering process gas to the process gas supply channel of the torch and into the arc chamber.

2 more elements

Dependencies are inferred from the claim text.