Abstract: A method and apparatus for supplying lime sludge to a rotary kiln guides the flow of the lime sludge into the kiln, and the flow of flue gases out of the kiln, in distinct paths so that contact between the lime sludge entering the kiln and flue gases exiting the kiln is substantially prevented. This is typically accomplished by providing a general horizontal tubular duct interiorly of the kiln first end and extending into a substantially vertical flue gas conduit with an annular chamber defined between an outer surface of the tubular duct and an inner surface of an inlet to the first end of the rotary kiln. The lime sludge is introduced into the annular chamber. Spiral feeding blades are preferably provided on the outer surface of the tubular duct and the duct rotates with the rotary kiln so that the spiral feeding blades engage the lime sludge and move it toward the kiln. The lime sludge is preferably dried before it is fed into the annular chamber.

Abstract: A reverse air flow oven for symmetrically heating product inserted within a heating chamber in the oven. The oven includes duct work configured symmetrically about the heating chamber, and a fan provides continuous circulation through the duct work and the heating chamber. The duct work also includes a pair of doors having complimentary configurations so that in one configuration, the air flow is in a first direction, and in the complimentary configuration, the doors cause air flow in the opposite direction. Further, a perforated plate regulates and equalizes air flow across the heating chamber and includes valve plates for controlling a build up of static pressure within the heating chamber.

Abstract: A heat-controlling device is provided with a transporting carriage for supporting and transporting a semiconductor substrate and a heating device having a plurality of heaters which apply heat in the width-wise direction of the heat-receiving member that is perpendicular to the transporting direction thereof and which are individually controlled by a controller. The controller only operates a set of the heaters that are adjacent the semiconductor substrate. Among the heaters being operated, those heaters, which are located at at least the leading end and the rear end in the transporting direction, have their outputs successively varied in accordance with the movement of the semiconductor substrate. Thus, it becomes possible to easily narrow the temperature distribution of the semiconductor substrate merely by controlling the output of the heaters.