Abstract: An emergency air shutdown system for diesel engines which has air intake manifold and curved discharge tubes leading into the manifold for a plurality of cylinders, the system comprising a valve member for each discharge tube and pivotal mounting means therefor to cause movement of the valve member about an axis substantially parallel to the air flow through the discharge tube between an open position outside the path of air flow and a closed position across the tube to block the air flow. Locking means are provided for keeping the valve in an open position, and activating means are provided to effect release of the locking means so as to permit rapid movement to the closed position across each tube.

Abstract: A high capacity blender has been devised which is adaptable for use in achieving the proper blend of liquid-to-liquid or liquid-to-solid constituents making up a gel composition for use in fracturing oil and gas well formations in which a high speed impeller is mounted for rotation concentrically within an outer casing and has a solids inlet which is isolated from the liquid inlet. A series of liquid inlet apertures are disposed in outer concentric surrounding relation to the impeller, and impeller vanes within the impellers are operative to impart a centrifugal force to solids introduced therein whereby to direct the solids and materials radially and outwardly under considerable force into the liquid stream which is directed axially along the inner wall of a mixing chamber.