METHOD AND SINTERING CRADLE FOR MANUFACTURING SINTERED PELLETS Russian patent published in 2002 - IPC

FIELD: nuclear power engineering; pelletized nuclear fuel manufacture. SUBSTANCE: molded powder is mixed up with binder (ammonia stearate NH₄(C₁₇H₃₅COO) in proportion of 0.2-0.4% and pellets are pressed Then they are placed in cradles which are mounted in tunnel- type walking-beam furnace running continuously and sintered in reducing environment. Pallet-filled cradles are passed in opposition to reducing medium through three zones of binder removing section, through two zones of preheating section, through three zones of sintering section, and through cooling section. Before discharging pellet-carrying cradles reducing medium pressure within furnace is brought down to 0.23-0.27 of atmospheric value by opening entrance pellet-charging door in automatic mode for 3-5 s to burn gaseous products of raw-pellet decomposition products in fire-curtain flame of furnace. Pellet sintering cradle is made of molybdenum and has bottom, perforated walls, and false perforated bottom elevated through certain distance from bottom Cradle bottom has two rows of holes spaced apart through distance equal to walking-beam width of furnace. EFFECT: improved quality of sintered pellets; enhanced output without using more furnaces. 9 cl, 4 dwg