PROBLEM TO BE SOLVED: To provide a hydroponic apparatus allowing an improvement in dissolved oxygen concentration in a nutritious liquid in a cultivation tank, and promotion of the growth of a plant.SOLUTION: There is provided the hydroponic apparatus A including the cultivation tank 60 in which a cultivation panel for cultivating the plant is installed, and a pump unit P for feeding the nutritious liquid through a circulation path 65 into the cultivation tank 60. The pump unit P includes: a Roots pump 3 in which a pair of rotors housed in a pump casing 4 provided with a suction port and a discharge port are rotated and driven with a driving motor and a pipeline installed in a suction pipe 45 connected to the suction port thereof. A collision member 50 for making the sucked nutritious liquid collide therewith and an air introduction port 46 are provided in the pipeline. The nutritious liquid is sucked from a water tank 71 by operation of the Roots pump 3, and the nutritious liquid in which air taken from the air introduction port 46 is mixed is made to collide with the collision member 50 to thereby generate a large amount of air bubbles. The nutritious liquid containing the micronized air bubbles produced with the pump is released into the cultivation tank 60.COPYRIGHT: (C)2012,JPO&INPIT【課題】栽培槽内の養液中の溶存酸素濃度を向上させ、植物の生育を助長可能な水耕栽培装置を提供すること。【解決手段】植物を栽培する栽培パネルが設置される栽培槽60と、栽培槽60へ循環経路65を介して養液を送り込むポンプユニットPを備えた水耕栽培装置Aにおいて、ポンプユニットPは、吸込口と吐出口を設けたポンプケーシング4内に収められた一対のロータを駆動モータにより回転駆動されるルーツポンプ3と、その吸込口に接続される吸入管45に介装される管路とからなり、吸い込んだ養液を衝突させる衝突部材50と空気導入口46を該管路に設け、ルーツポンプ3の運転により水槽71から養液を吸い込むと共に空気導入口46から取り込まれる空気が混入した養液を衝突部材50に衝突させることにより多量の気泡を発生させ、かつ、当該ポンプによって生ずる微細化気泡を含む養液を栽培槽60内へ放出させる。【選択図】図1
