主权项 |
1. A flow passage device comprising:
a flow passage through which a fluid flows in a direction crossing a vertical direction; an introducing space that has a supply port opening on an upper surface thereof and that has a bottom surface, the introducing space communicating with an end portion of the flow passage; and a connecting space one end of which is connected to the end portion of the flow passage and the other end of which is connected to the introducing space, the connecting space having a bottom surface, the connecting space allowing a gas-liquid interface to be formed due to surface tension, the gas-liquid interface being larger than a section of the flow passage, wherein a direction in which the gas-liquid interface faces crosses the vertical direction, wherein a part of a side of a bottom portion of the introducing space is open and connected to the connecting space, wherein the bottom surface of the introducing space and the bottom surface of the connecting space are on a single flat surface, and the introducing space is not narrowed from the bottom surface to the supply port opening, wherein neither a length, in the same axis as that of the flow passage, of the introducing space nor a width of the introducing space is narrowed, wherein the direction in which the gas-liquid interface faces is the vertical direction in a case where a liquid surface of a liquid in the introducing space is situated higher than an upper surface of the connecting space, and wherein, in a case where the liquid in the introducing space decreases and the bottom surface of the introducing space is exposed, the liquid, due to surface tension of the liquid, moves such that the liquid adheres to a lower periphery portion of the introducing space while the gas-liquid interface is formed, in a direction crossing the vertical direction, between the upper surface and a bottom surface of the connecting space. |