Patent ID: 7172336

Claim:
An in-line mixing apparatus for mixing a plurality of chemical solutions, the apparatus comprising: a mixing apparatus main body, including a plurality of injection inlets and at least one discharge outlet, the plurality of chemical solutions being injected at the injection inlets, the plurality of injection inlets including an upstream injection inlet and at least one downstream injection inlet which are separately disposed; a mixing flow path formed inside the mixing apparatus main body, which communicates with the plurality of injection inlets and the discharge outlet; a rotary blade disposed in the mixing flow path between a vicinity of the downstream injection inlet and the discharge outlet for mixing the plurality of chemical solutions injected at the injection inlets, the rotary blade including a rotation shaft; and at least one of a shaft sealing portion and a mechanical seal disposed at the rotation shaft of the rotary blade for sealing the rotation shaft, the at least one of a shaft sealing portion and a mechanical seal being disposed at a downstream side of the upstream injection inlet and being disposed at an upstream side of the downstream injection inlet, wherein a chemical solution injected at the upstream injection inlet forms a flow along the mixing flow path from the upstream injection inlet to the discharge outlet, and wherein the at least one of a shaft sealing portion and a mechanical seal comprises: a rotation ring member; a seal ring member; and pressing means for urging the seal ring member toward the rotation ring member, and the apparatus further comprises liquid contact preventing means for substantially preventing the chemical solutions in the mixing flow path from coming into contact with the pressing means.