How to choose and use plasma source

How to choose a  suitable plasma source is extremely important for cutting quality, cutting speed, cutting efficiency.

1.Cutting current: It decides cutting thickness and speed---cutting ability.

1)When enlarge it,  arc energy increases,cutting ability increases;

2) When enlarge it, arc diameter increases,kerf becomes wide;

3)If cutting current is too large, nozzle thermal load increases, nozzle will damage, cutting quality will decline. Thus before cutting,w e should choose proper cutting current and nozzles according to plate thickness.

2. Cutting speed:Best speed should depends on its handbook. Regarding to different thickness, materual, melting point, thermal conductivity and surface tension after melting,there is different cutting speed. 

1) Increase cutting speed moderately can improve cutting quality----cutting edge will be narrrow and more flat and reduce heat distortion.

2)If speed too fast, heat input will be underrequired value,  jet flow can not blow offmelting fusant, thus to form large and dross, cutting edge not smooth.

3) If speed too slow, kerf will be large, arc will even die out.

So, cutting speed is very importabt for good cutting quality.

3.Arc voltage: Usually output voltage is cutting voltage.Plasma power source usually has very high open circuit voltage &working volt.When use nitrogen,  hydrogen or air, required voltage will be higher.When currenct is fixed, rise of voltage means rise of enthalpy and cutting ability.If at the same time, you reduce jet diameter and increase air flow rates, you will get faster cutting speed and better cutting quality.

4.Working gas  and flow rates: Working gas includes cutting gas and process gas, some equipement require arcing gas. We need to choose proper gas according to material, thickness and cutting mode. Cutting gas should not only assure the formation of plamsa arc jet, but also blow off dross and oxide in the kerf. Too large air flow will take away more arc energy, which will shorten jet length and reduce cutting ability and cause unstability of the arc. Too small air flow will weaken straightness of plasma arc and thus reduce the cutting depth,cause dross.

So, air flow should coordinate with cutting current.

Present plasma power source apply air pressure to control air flow, because when diameter of cutting nozzle is fixed, air flow depends on air pressure. To cut certain thickness, we need to choose proper air pressure accodning to datas provided by suppliers. Usual working gas including: oxygen ,nitrogen, hydrogen, argon or air and mixed gas of argon, nitrogen and so on.