Abstract: A gate valve having a top inlet and bottom outlet is provided with a horizontally disposed head slidable between closed and open positions. The valve body includes a seat concentric with an inlet passage and adapted to cooperate with a sealing surface on the head. An annular sleeve is provided within the inlet passage with one end of the sleeve being in contact with the sealing surface on the head. The sleeve and seat cooperate with the valve body and head to define an annular space. A means is provided to pressurize the space immediately prior to contact between the head and the seat. The head is biased to a closed position in the event of power failure. The valve is particularly designed for controlling downward flow of high temperature particulate material under high pressure.

Abstract: A rotary feeder is disclosed for feeding abrasive materials at high temperatures up to about 2300.degree. F. Each of the rotor and stator have preformed refractory inserts removably retained in position without separate fasteners being used. The inserts are preferably preformed with a camber to facilitate spring-like retention thereof.

Abstract: A continuous mixer and unloader is disclosed for the purpose of moisturizing dry material during removal from a storage bin to avoid dust pollution which could occur during loading and transport. A screw conveyor feeds the material to a mixing drum circumscribing the conveyor. Stationary curved blades direct fine particles into a water shower spray located within said drum.