Structural characteristics of atmosphere furnace and matters needing attention in use
Structural characteristics and use precautions controlled atmosphere furnace
1.Construction features controlled atmosphere furnace
Must ensure tightness stove, the furnace shell with continuous welds, door and door frame contact surface machining, all holes have sealing device, a front and rear chambers, fire curtain and explosion-proof equipment.
Furnace atmosphere should be evenly distributed, the installation of a circulating fan. Using a large cross-section resistance plate or radiant tube as a heat source, in a carburizing atmosphere of work, electric surface will be carbon deposition, a large section of the resistance plate is easy to clear carbon and prolong life. Lining, requires lining material with anti-reducing, anti-carburizing ability, resistance furnace lining thickness is thicker than the average because the controlled atmosphere furnace gas thermal conductivity than air. Thermocouples in a reducing atmosphere to be contaminated, the output power is reduced, so that the actual temperature is higher than the command temperature. To this end, it requires the use of controlled atmosphere furnace heat-resistant steel casing to protect the thermocouple large diameter casing hot end closed, cold end must be open, the protective gas can escape, while regular calibration of thermocouples. Controlled atmosphere furnace mechanization, high degree of automation, foreign countries have been using computer control.
2.Note the use of controlled atmosphere furnace
Consumption of controlled atmosphere, in order to maintain the furnace atmosphere composition free from outside interference, the need to maintain a positive pressure controlled atmosphere furnace, gas furnace pressure is generally higher than atmospheric pressure Drag tens to hundreds PA PA. Therefore, in the furnace work, often through controlled atmosphere furnace door, letters and other imprecise sand out of the furnace at the Plaza, need to continue to supplement the controlled atmosphere furnace. Atmosphere with a simple method to determine the consumption theory only as a reference. Empirical formulas and data but also versus actual analysis can be used as determined by the post-controlled atmosphere furnace gas capacity.
Safe operation, a controlled atmosphere of flammable gas, pay special attention to prevent an explosion, and poisoning. At each subsequent shutdown to resume production, it must first use the drive to make the furnace air, nitrogen - about the equivalent of 4,5 times the furnace volume, only to later diffuse nitrogen Walter controlled atmosphere furnace.