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 controllingthe CO content of a furnace atmosphere for carburizing andcarbonitriding metal workpieces in a furnace, whereby thefurnace atmosphere is produced by direct feeding of a mixtureconsisting of an oxidizing agent and a hydrocarbonaceous fuelas well as perhaps ammonia into the furnace. To ensure acontinuous and trouble-free operation of the installationwithout sooting of the furnace, it is proposed that the COcontent of the furnace atmosphere be ascertained and that a COforming substance is added when a freely adjustable minimum COcontent of the furnace atmosphere is attained. The device forcarrying out this process has a CO analyzer 1 for ascertainingthe CO content in the furnace atmosphere and a programmable COcontrol 3 for actuating a valve 4 and, if applicable, a pump 5in dependency on the CO content in the furnace atmosphere.