PROBLEM TO BE SOLVED: To provide a technique capable of widening a range in which a jet flow can be directly exposed to a film-like flow while preventing scattering of droplets of the jet flow. SOLUTION: An injection water channel 34 capable of injecting an injection flow F1 forward and a discharge water channel 36 capable of discharging a film-like flow F3 passing above the injection flow F1 forward are provided, and the film-like flow F3 flows. It has an endped film shape in a cross section orthogonal to the direction. Even if the membranous flow F3 is deflated, the membranous flow F3 does not approach the jet flow F1 and the early confluence of the membranous flow F3 and the jet flow F1 can be avoided. Along with this, the film-like flow F3 can prevent the droplets of the jet flow F1 from scattering, and the range in which the jet flow F1 can be directly exposed can be widened. [Selection diagram] Fig. 1【課題】膜状流により噴射流の飛沫の飛散を防止しつつ、噴射流を直接に浴びられる範囲を広くできる技術を提供する。【解決手段】噴射流Ｆ１を前方に噴射可能な噴射水路３４と、噴射流Ｆ１の上方を通る膜状流Ｆ３を前方に吐出可能な吐出水路３６と、を備え、膜状流Ｆ３は、流れ方向に直交する断面において有端膜状をなす。膜状流Ｆ３がすぼまったとしても、膜状流Ｆ３が噴射流Ｆ１に近づくことがなくなり、膜状流Ｆ３と噴射流Ｆ１の早期の合流を避けられる。これに伴い、膜状流Ｆ３により噴射流Ｆ１の飛沫の飛散を防止しつつ、噴射流Ｆ１を直接に浴びられる範囲を広くできる。【選択図】図１
