Abstract: A bubble cap assembly for use in fluidized bed boilers, furnaces, or reactors, has a bubble cap, a stem, and at least one pin. One end of the stem is inserted into the bubble cap. The bubble cap has outlet holes for delivering a fluidizing medium, typically into a bed of granulated material, but which prevent backsifting of the granulated material into the bubble cap. The bubble cap also has at least one insertion hole, through which a pin may be inserted. When the pin is inserted through the bubble cap insertion hole, it also occupies a groove or indentation on the stem thereby preventing separation or disassembly of the bubble cap and stem combination. An elastic gasket may be provided between the bubble cap and stem to form a fluid tight connection.

Abstract: A tray which is easily attached to the rim of the cockpit of a kayak. The top surface of the tray is provided with recessed compartments for retaining various items therein. At least one recess is designed to retain a standard-sized beverage container. A clamp, formed on the tray, is designed to securely retain the kayak's paddle thereby freeing the rower's hands when desired. The tray is fabricated from molded plastic or a hard rubber.

Abstract: A tray which is easily attached to the rim of the cockpit of a kayak. The top surface of the tray is provided with recessed compartments for retaining various items therein. At least one recess is designed to retain a standard-sized beverage container. A clamp, formed on the tray, is designed to securely retain the kayak's paddle thereby freeing the rower's hands when desired. The tray is fabricated from molded plastic or a hard rubber.

Abstract: A refractory brick particularly suited for constructing a diffusor wall for an industrial heat source. The brick includes a substantially tubular body having a first end, a second end opposed to the first end, an inner surface defining a passageway extending in the longitudinal direction of the body from the first end to the second end, and an outer peripheral surface extending from the first end to the second end. The outer peripheral surface has a complementary shape that allows mating of a plurality of the bricks to form cooperatively a diffusor wall. Mating means is formed on or in the outer peripheral surface for engaging corresponding mating means formed on or in outer peripheral surfaces of adjacent bricks when assembled as a diffusor wall.

Abstract: A ceramic ferrule, an array of ceramic ferrules, and a ceramic ferrule refractory wall, all for shielding a tube sheet/boiler tube assembly of a heat exchanger connected to an industrial heat source. The head portion of each ferrule replaces conventional cast refractory walls, and has an outer-peripheral shape that allows the ferrules to mate at the operating temperature of the industrial heat source. The mated ferrules expand and contract substantially independently of one another, but form a substantially gas-tight barrier for shielding the tube sheet/boiler tube assembly from the waste gas of the industrial heat source.