A continuous sintering furnace has an entrance-side deaerating chamber (23) through which trays (22) carrying a material (1) to be sintered may pass, preheating, heating and cooling zones (37, 38 and 39) into which the trays (22) are sequentially fed from the deaerating chamber (23), an exit-side deaerating chamber (26) through which the trays (22) having passed through the cooling zone (39) may pass, a pusher (35) for pushing the trays (22) from the deaerating chamber (23) to the preheating zone (37), a puller (36) for pulling the trays (22) from the cooling zone (39) to the deaerating chamber (26), an intermediate puller (43) for pulling the trays (22) from the heating zone (38) to the cooling zone (39), a vertically movable door (28) between the deaerating chamber (23) and the preheating zone (37), a vertically movable intermediate door (41) adjacent to the door (28) and arranged at the upstream end of the preheating zone (37) in the direction of movement of the trays (22), a vertically movable intermediate door (42) between the heating and cooling zones (38) and (39) and a vertically movable door (29) between the cooling zone (39) and the deaerating chamber (26). When the door (42) is in its closed position, heat flow to the cooling zone (39) is suppressed. Movement of the trays (22) in the cooling zone (39) is effected by the intermediate puller (43), thereby decreasing the number of trays (22) to be moved by the pusher (35).

A continuous sintering furnace has an entrance-side deaerating chamber (23) through which trays (22) carrying a material (1) to be sintered may pass, preheating, heating and cooling zones (37, 38 and 39) into which the trays (22) are sequentially fed from the deaerating chamber (23), an exit-side deaerating chamber (26) through which the trays (22) having passed through the cooling zone (39) may pass, a pusher (35) for pushing the trays (22) from the deaerating chamber (23) to the preheating zone (37), a puller (36) for pulling the trays (22) from the cooling zone (39) to the deaerating chamber (26), an intermediate puller (43) for pulling the trays (22) from the heating zone (38) to the cooling zone (39), a vertically movable door (28) between the deaerating chamber (23) and the preheating zone (37), a vertically movable intermediate door (41) adjacent to the door (28) and arranged at the upstream end of the preheating zone (37) in the direction of movement of the trays (22), a vertically movable intermediate door (42) between the heating and cooling zones (38) and (39) and a vertically movable door (29) between the cooling zone (39) and the deaerating chamber (26). When the door (42) is in its closed position, heat flow to the cooling zone (39) is suppressed. Movement of the trays (22) in the cooling zone (39) is effected by the intermediate puller (43), thereby decreasing the number of trays (22) to be moved by the pusher (35).

A method and an apparatus for sintering a compact of particulate material for a ceramic or of particles of metal, or a ceramic precursor film, wherein the sintering is performed by heating and burning the compact or the ceramic precursor film while applying centrifugal force to the compact or the ceramic precursor film.

A continuous sintering furnace has an entrance-side deaerating chamber (23) through which trays (22) carrying a material (1) to be sintered may pass, preheating, heating and cooling zones (37, 38 and 39) into which the trays (22) are sequentially fed from the deaerating chamber (23), an exit-side deaerating chamber (26) through which the trays (22) having passed through the cooling zone (39) may pass, a pusher (35) for pushing the trays (22) from the deaerating chamber (23) to the preheating zone (37), a puller (36) for pulling the trays (22) from the cooling zone (39) to the deaerating chamber (26), an intermediate puller (43) for pulling the trays (22) from the heating zone (38) to the cooling zone (39), a vertically movable door (28) between the deaerating chamber (23) and the preheating zone (37), a vertically movable intermediate door (41) adjacent to the door (28) and arranged at the upstream end of the preheating zone (37) in the direction of movement of the trays (22), a vertically movable intermediate door (42) between the heating and cooling zones (38) and (39) and a vertically movable door (29) between the cooling zone (39) and the deaerating chamber (26). When the door (42) is in its closed position, heat flow to the cooling zone (39) is suppressed. Movement of the trays (22) in the cooling zone (39) is effected by the intermediate puller (43), thereby decreasing the number of trays (22) to be moved by the pusher (35).

Sintering machine for the automated production of sintered tips where the mold is permanently resident inside the machine and it is shifted between several stations where all the single operations necessary to accomplish the sintering cycle are carried out automatically. The machine comprises at least one sintering station (2) and one service station (3,4), one or more laterally opening molds (14,15) capable of sliding between said stations, means to accomplish the operations of loading, unloading and cleaning the molds, means to control the sequence of the operations, and means to provide pressure and heat.

Each mold comprises a plurality of elementary cells inside each one of them one tip is being sintered. Each cell is provided with an upper plunger and a lower plunger and can be opened horizontally as well as vertically.

The invention relates to a process and apparatus for producing a shaped silicon nitride sintered body. A mixture of silicon nitride powder and a sintering assistant agent are shaped to prepare a shaped body. The shaped body (1) is sintered in an atmosphere of an N2 gas or an inactive gas including an N2 gas. The CO concentration in the atmosphere contacting the shaped body (1) during sintering is not higher than about 30 ppm. The invention also provides a process for producing a silicon nitride sintered body wherein a mixture of silicon nitride powder and a sintering assistant agent are shaped to prepare a shaped body (1). The shaped body (1) is sintered in a sintering case, at least the inner surface of which is a carbon-free heat-proof material. When required, the shaped body is supported by a jig (22) of carbon-free heat-proof material. The atmosphere is replaced in the sintering case with an N2 gas or an inactive gas including an N2 gas, and the shaped body in the sintering case is sintered under conditions such that the atmosphere in a furnace cannot come in contact with the shaped body (1). The apparatus includes a furnace core chamber (30) defined by providing partitions inside a furnace and a heating source (25), and an atmospheric gas supplying pipe (26) for supplying an N2 gas or an inactive gas including an N2 gas into the furnace core chamber (30), wherein at least the inner surface of the furnace core chamber (30) is a carbon-free heat-proof material. The shaped body (1) is disposed in the furnace core chamber (30) directly and when required the shaped body (1) is supported by a jig (22) of carbon-free heat-proof materials. The invention provides a satisactory process of producing a shaped silicon nitride sintered body having a high density and superior strength while reducing the degeneration of its surface during sintering and solving the problems associated with conventional processes. The invention also provides an economical furnace for sintering a shaped silicon nitride body which solves the problems associated with conventional processes.

Die Erfindung bezweckt eine Seitenführung von Schubro­sten, die es erlaubt, sowohl die Schubspalte zwischen einander überlappenden, beweglichen Rostreihen (12) auch die Randspalte eng einzustellen und frei von Verschleiß und Temperaturdehnung zu halten. Die Lösung erfolgt mittels Zugelementen (4), an denen ein Schwingrahmen (2,3) aufgehängt ist und die mit der Rostlängsebene einen Winkel (α) von mehr als 3 Grad bilden. Die ent­stehenden Querkräfte oder bzw. und die Formsteifigkeit bewirken eine Seitenführung des Rostes, die die ver­schleißbehafteten Bauelemente des bewegten Tragwerks überflüssig macht und es erlaubt, die Randspalte des Rostes eng und verschleißfrei zu halten. Durch Anordnung der Zugelemente in belüfteten Ausstülpungen (16) des unteren Gehäuses werden weiterhin Längenänderungen durch Wärmedehnung ausgeschaltet.