PROBLEM TO BE SOLVED: To provide a gas-liquid mixing device which can naturally suck gas even when a flow rate of liquid is a low flow rate, and can fine the gas and mix the fined gas in the liquid.SOLUTION: A gas-liquid mixing device 1 of the present invention includes a diametrically reduced part 4 with an inner diameter reduced toward the advancing direction TD of the liquid, a gas-liquid mixing part 5 which is provided downstream from and concentrically with the diametrically reduced part 4 and has an inner diameter larger than the smallest inner diameter of the diametrically reduced part 4, a diametrically enlarged part 7 which is provided downstream from and concentrically with the gas-liquid mixing part 5 and has a flow passage cross-sectional area increased toward the advancing direction TD, a ring-shaped wall surface 2 which expands to the outer peripheral side from the downstream end of an inner peripheral surface of the diametrically reduced part 4 and is connected to the upstream end 5a of an inner peripheral surface of the gas-liquid mixing part 5, and a gas introducing part 6 for introducing gas into the gas-liquid mixing part 5 via a gas passage 6a. The gas passage 6a is formed by contacting an opening formed on an inner wall of the gas-liquid mixing part 5 with the ring-shaped wall surface 2, and the gas introducing part 6 makes the gas flow in the gas-liquid mixing part 5 along the tangential direction of the inner peripheral surface of the gas-liquid mixing part 5.COPYRIGHT: (C)2014,JPO&INPIT【課題】液体の流量が低流量である場合にも自然吸気を可能とし、且つ、気体を微細化して液中に混合することができる気液混合装置を提供すること。【解決手段】本発明の気液混合装置1は、液体の進行方向TDに向かって内径が縮小する縮径部4と、縮径部4の下流側に、縮径部4に対し同心的に設けられ、縮径部4の最小内径より大きい内径を有する気液混合部5と、気液混合部5の下流側に、気液混合部5に対し同心的に設けられ、進行方向TDに向かって流路断面積が増大する拡径部7と、縮径部4の内周面の下流端から外周側に広がって気液混合部5の内周面の上流端5aに繋がるリング状の壁面2と、気体通路6aを通して気液混合部5内に気体を導入する気体導入部6とを備え、気体通路6aが気液混合部5の内壁に形成する開口がリング状の壁面2に接して形成され、気体導入部6は、気液混合部5の内周面の接線方向に沿って気体を気液混合部5内に流入させる。【選択図】図1
