Cooling of recirculating gas with water as cooling medium

The problem

In many process systems quick and controlled cooling of parts and material is required to assure short production cycles and a correct quality. Harjavalty, Finland in the OM Group Inc. is a leading manufacturer of semi-manufactured nickel based products. One of the products is nickel briquets the size of normal eggs. The production process includes cooling of the briquets from 900 to 150°C in a twelve meter long tunnel with a conveyor belt. The cooling with a surrounding water jacket has only 150 kW effect and needs upgrading.

The solution – AirCross reduced cooling time by 60%

Effective cooling is achieved by re-circulating non-oxidising nitrogen through AirCross 21. The nickel briquets and the nitrogen move in counter flow to each other. The results with AirCross have proved to be excellent.

Not only was cooling time reduced by 60%. The energy transferred to the water is used in the heating system. Due to the nitrogen inside the cooling tunnel the temperature was much more even between different parts of the tunnel. This increased the quality of the nickel briquets. After the positive results Harjavalty has equipped other nitrogen cooling systems with AirCross 21.