Abstract: A rotating disc reactor for production of sodium hydrosulfite comprising a reactor main housing containing a plurality of elongated reaction chambers with at least partially arcuate interior periphery. Each reaction compartment contains a top gaseous layer, an intermediate buffer solution layer, and a bottom sodium amalgam layer. Positioned in each compartment is a rotatable shaft with a plurality of rotatable discs mounted thereon for reacting and mixing the three layers of reactants. The reactor includes means for distributing amalgam and means for distributing recirculated buffer solution into each reaction compartment. At least one of the side walls of the housing is connected to an end box having inlet and outlet means for circulating the amalgam and the sodium hydrosulfite product. The reactor further includes a sulfur dioxide inlet manifold having an arcuate interior which is offset from the reactor housing.

Abstract: A method of assembling progressing cavity pump of the Moineau type having a helically externally threaded rotor coacting with an internally helically threaded stator. In a Moineau pump where the pump casing is a singular tubular unit, the stator is normally bonded to the inside of a tubular housing with an adhesive. When such pumps are used to pump a corrosive fluid, such as caustic soda, the adhesive can be attached and the stator thus freed to rotate. To prevent the stator from rotating, studs are driven through the housing and into the stator. The location of these studs can be pre-marked by use of a suitable template. Also, the driven studs can be welded to the housing to prevent leakage or loosening.