Temperature control is an essential quality factor in food industry and in metal fabrication. Many processing steps apply heat to the work piece. This can affect dimensions and material structure. Cooling time is required to exclude the possibility of overheating. The cooling window can be reduced if carbon dioxide snow or liquid nitrogen is used as the cooling agent.
Liquid nitrogen
It takes 0.5-1 litre of liquid nitrogen per one kilo of metal to reduce the temperature from +20 °C to -196 °C (ΔT = 216 degrees). Liquid nitrogen must be handled like boiling water because of the risk of frost damage.
Dry ice
It takes about 0.2 kilos of dry ice per one kilo of metal to reduce the temperature by 98°C. Dry ice can be sprayed or applied as pellets.