Abstract: A system for dosing a stream of fluid with at least one active substance is provided. The system includes a housing which defines a chamber having an inlet and an outlet to enable the flow of fluid through the chamber. The system also includes a block containing the active substance, the block including a body having an outer surface and a passage therethrough defining an inner surface. The block is positioned within the housing chamber in an operative position between the inlet and the outlet so that in use fluid flows over the inner and outer surfaces of the block to dissolve and/or erode the block.

Abstract: A system for dosing a stream of fluid with at least one active substance is provided. The system includes a housing which defines a chamber having an inlet and an outlet to enable the flow of fluid through the chamber. The system also includes a block containing the active substance, the block including a body having an outer surface and a passage therethrough defining an inner surface. The block is positioned within the housing chamber in an operative position between the inlet and the outlet so that in use fluid flows over the inner and outer surfaces of the block to dissolve and/or erode the block.

Abstract: A block for chemically dosing a stream of fluid flowing past the block, the block comprising at least one surface for the fluid to flow past to dissolve and/or erode the block, wherein the block is shaped to enable the at least one surface to be dissolved and/or eroded without a substantial change in the area of the at least one surface.

Abstract: A block for chemically dosing a stream of fluid flowing past the block, the block comprising at least one surface for the fluid to flow past to dissolve and/or erode the block, wherein the block is shaped to enable the at least one surface to be dissolved and/or eroded without a substantial change in the area of the at least one surface.