PROCESS AND DEVICE FOR CONTROLLING THE CARBON MONOXIDE CONTENT OF A FURNACE ATMOSPHERE FOR CARBURIZING AND CARBONITRIDING METAL WORKPIECES

摘要

The invention concerns a process and a device for controlling the CO content of a furnace atmosphere for carburizing and carbonitriding metal workpieces in a furnace, whereby the furnace atmosphere is produced by direct feeding of a mixture consisting of an oxidizing agent and a hydrocarbonaceous fuel as well as perhaps ammonia into the furnace. To ensure a continuous and trouble-free operation of the installation without sooting of the furnace, it is proposed that the CO content of the furnace atmosphere be ascertained and that a CO forming substance is added when a freely adjustable minimum CO content of the furnace atmosphere is attained. The device for carrying out this process has a CO analyzer 1 for ascertaining the CO content in the furnace atmosphere and a programmable CO control 3 for actuating a valve 4 and, if applicable, a pump 5 in dependency on the CO content in the furnace atmosphere.