| 摘要 |
A water treatment apparatus (l) comprises a vessel (2) that defines a chamber (3) adapted to contain a water treatment chemical (4) over which a dosing liquid can flow from an inlet (6) to form a dosing reservoir (8) at the bottom of the vessel (2). A supply (5) of dosing liquid is connected to the inlet (6) of the vessel (2). The interior of the vessel (2) communicates with a conduit (9) along which an entraining pressurized flow of water can be fed for treatment and via an opening (10) in the conduit (9) that is connected to a bottom outlet (11) of the vessel (2). A venturi (12) is located in the conduit (9) adjacent the opening (10) so that the velocity of the pressurized water is increased as it passes over the opening (10) and entrains a dosing stream from the dosing reservoir (8) into the pressurized flow. The venturi (12) also applies suction to the interior of the vessel (2), which draws dosing liquid into the vessel (2) from the supply (5). In this way, the production of the dosing stream takes place under negative pressure conditions so that if the integrity of the vessel (2) is compromised during operation, the flow of dosing liquid into the vessel (2) will immediately cease and there can be no pressure build-up within the vessel (2) of dangerous fumes. |
