초록 ▼

Workpieces are quenched by gases in a heat-treatment system (1) and the circulated gases are recooled on cooling surfaces (12, 15) in at least one heat exchanger (11, 14), the cooling surfaces (15) of the heat exchanger (14) are cooled by a primary refrigeration unit (20) and a refrigerant to temper

Workpieces are quenched by gases in a heat-treatment system (1) and the circulated gases are recooled on cooling surfaces (12, 15) in at least one heat exchanger (11, 14), the cooling surfaces (15) of the heat exchanger (14) are cooled by a primary refrigeration unit (20) and a refrigerant to temperatures below 0°C., preferably to temperatures below -20°C. or even below -40°C., to increase the intensity of the quenching. To reduce the size and power of the refrigeration unit (20), the quenching gas is sent in succession through at least one heat exchanger (11) cooled with water and at least one heat exchanger (14) cooled by a refrigerant. To reduce the size and power of the refrigeration unit (20) even further, this unit and a secondary refrigerant are used initially to cool down a storage volume of the primary refrigerant, such as a cooling brine, being stored under little or no pressure, to a temperature below 0°C., whereupon this primary refrigerant is sent through the heat exchanger (14), at least one of which is present.

대표청구항 ▼

Process for quenching workpieces with a quenching gas comprising quenching said workpieces by passing said quenching gas over said workpieces, thereby heating said quenching gas, passing said quenching gas through a heat exchanger having cooling surfaces which are cooled with a primary refrigerant,

Process for quenching workpieces with a quenching gas comprising quenching said workpieces by passing said quenching gas over said workpieces, thereby heating said quenching gas, passing said quenching gas through a heat exchanger having cooling surfaces which are cooled with a primary refrigerant, and cooling said primary refrigerant to a temperature below 0°C. by circulating said primary refrigerant in a closed circuit through refrigeration apparatus comprising a refrigeration unit.