Yuanben flow switches used for plasma cutters and the cooling system
Water-cooling systems for plasma cutters are very similar to those used in automobile engines, use water and coolant, a pump, cooling hoses, and a heat exchanger to remove energy from a heat source. In an automobile, the heat source is the combustion chamber inside the engine, which operates at temperatures in excess of 1000°C. In a plasma torch the heat source is the plasma chamber inside the torch where the temperature of the arc can exceed 10,000°C.
A plasma torch, like an engine, is cooled by a combination of radiation, convection, and conduction. Energy radiates from the arc in the form of intense ultraviolet rays. Heat converts away from the torch and torch parts through moving gas or air. And finally the water-cooling system conducts heat away from the torch parts into the coolant.
What happens when conductive cooling is reduced? The system overheats rapidly. When the plasma system overheats it will also cost you time and money. An overheating plasma system will wear out torch parts quickly and eventually may burn out the torch and leads. If the problem goes uncorrected, a motor and pump may have to be replaced. But the downtime and expense of overheating can be avoided. Understanding the system and its components will help you troubleshoot problems when they occur and prevent future failures through preventative maintenance.
A typical cooling system of plasma cutters consists of a torch, motor, pump, cooling lines, flow switch, filter, heat exchanger and reservoir with float level switches and temperature switches.
Plasma torches that operate at 100-150A require water-cooling to keep the torch and parts from overheating. The copper electrode generates the plasma arc and is closest to the heat source so it requires direct cooling. Most high power electrodes are hollow milled to allow for improved cooling at the tip, a water tube extends into this milled area, closely spaced and precisely aligned to the electrode and provides a high flow velocity of coolant over the interior rear surface of the electrode.
Flow switches are designed to prevent catastrophic failure of the torch and parts in the event of low coolant flow. Brass block plunger type devices are typically used with a micro-switch that must be satisfied for the system to run. Now our flow switches is used in this system.