Abstract: A variable orifice assembly includes a housing defining a flow orifice therethrough and configured to be connected in fluid communication between two pipes of a particle conveyance system. The assembly includes a plurality of blades pivotally mounted to the housing to pivot between a retracted position and an extended position. Each blade includes a gas path edge. In the retracted position, the gas path edges of the blades conform to the flow orifice. In the extended position, the blades extend inward from the flow orifice wherein the gas path edge of each blade is spaced apart from the other blades.

Abstract: A variable orifice assembly includes a housing defining a flow orifice therethrough and configured to be connected in fluid communication between two pipes of a particle conveyance system. The assembly includes a plurality of blades pivotally mounted to the housing to pivot between a retracted position and an extended position. Each blade includes a gas path edge. In the retracted position, the gas path edges of the blades conform to the flow orifice. In the extended position, the blades extend inward from the flow orifice.

Abstract: A variable orifice assembly includes a housing defining a flow orifice therethrough and configured to be connected in fluid communication between two pipes of a particle conveyance system. The assembly includes a plurality of blades pivotally mounted to the housing to pivot between a retracted position and an extended position. Each blade includes a gas path edge. In the retracted position, the gas path edges of the blades conform to the flow orifice. In the extended position, the blades extend inward from the flow orifice.

Abstract: A variable orifice assembly includes a housing defining a flow orifice therethrough and configured to be connected in fluid communication between two pipes of a particle conveyance system. The assembly includes a plurality of blades pivotally mounted to the housing to pivot between a retracted position and an extended position. Each blade includes a gas path edge. In the retracted position, the gas path edges of the blades conform to the flow orifice. In the extended position, the blades extend inward from the flow orifice wherein the gas path edge of each blade is spaced apart from the other blades.

Abstract: A flow control apparatus for a coal pipe containing a stream of primary combustion air carrying pulverized solid fuel particles, includes a frame sealingly secured to an outside surface of the coal pipe around a window opening formed on one side of the pipe. An orifice plate having an orifice opening at the center is supported for pivotal movement in the coal pipe on a spindle extending radially outwardly from an edge portion on one side of the orifice plate and out through the window opening in the pipe. A bearing sleeve is provided for supporting the spindle for rotating movement about a spindle axis extending transversely of the coal pipe across the center thereof. A mounting plate structure for the sleeve is provided and is attached to the frame. A removable handle is attached on an outer end of the spindle for rotating the orifice plate in the coal pipe to vary the effective flow cross-section of the orifice opening for controlling the flow of coal and primary air to a burner.

Abstract: A flow control apparatus for a coal pipe containing a stream of primary combustion air carrying pulverized solid fuel particles, includes a frame sealingly secured to an outside surface of the coal pipe around a window opening formed on one side of the pipe. An orifice plate having an orifice opening at the center is supported for pivotal movement in the coal pipe on a spindle extending radially outwardly from an edge portion on one side of the orifice plate and out through the window opening in the pipe. A bearing sleeve is provided for supporting the spindle for rotating movement about a spindle axis extending transversely of the coal pipe across the center thereof. A mounting plate structure for the sleeve is provided and is attached to the frame. A removable handle is attached on an outer end of the spindle for rotating the orifice plate in the coal pipe to vary the effective flow cross-section of the orifice opening for controlling the flow of coal and primary air to a burner.