短語(yǔ)詞組短語(yǔ)Helical attenuation flow 螺旋衰減流helical -flow sludge blanket contact clarification 旋流接觸澄清helical laminar flow 層流螺旋流outer -helical-flow 外旋流eccentric annuli helical flow 偏心環(huán)空螺旋流tangential helical flow turbine [機(jī)]切向螺旋流式渦輪helical flow pump 旋流泵 返回 helical flow