| 摘要 |
PURPOSE:To reduce the concn. of solid matter in treated water by providing a protruding part protruding to the outside of the opened end part of a pressure reducing apparatus main body to a mouth whose inner peripheral surface is conical, and forming the protruding part into a curved surface expanding in the shape of a circle opposite to the conical surface of the inner periphery of the mouth. CONSTITUTION:A mouth 2 having a conical inner peripheral surface 2a is provided to the inner periphery of the opened end of a pressure reducing device main body 1 in a pressure flotation separation apparatus. In the apparatus, a protruding part 3 protruding to the outside of the opened end the main body 1 is provided to the mouth 2, and the cross section of the protruding part 3 is formed into a curved surface 3a which expands in the shape of a circle opposite to the conical surface 2a of the inner periphery of the mouth. Besides, a spout 4 for supplying pressurized sludge in the tangential direction in the inner periphery of the main body 1 and a supply port 6 for supplying a flotation assistant are provided. Consequently, since bubbles are scattered widely around the pressure reducing device, the circulating and the turbulent flow in the flotation vessel are reduced and the concn. of solid matter is decreased. |
