To provide an impeller back-to-back type multistage pump which can prevent erosion of an impeller and, further, can prevent vibrations generated by collision of high-speed fluid to the impeller.
A multistage pump includes: a first pump group 7A having a plurality of stage impellers 2; a second pump group 7B having a plurality of stage impellers 2 which are directed to the direction opposite to the impellers 2 of the first pump group 7A; a balance casing 41 in which an impeller inlet chamber 55 connected to a suction port 17 of the second pump group 7B and an annular channel 49 adjacent to the impeller inlet chamber 55 are formed; and a laminar flow mechanism 50 which separates the impeller inlet chamber 55 and the annular channel 49 from each other. The laminar flow mechanism 50 has a plurality of through-holes 51 which communicate the annular channel 49 and the impeller inlet chamber 55 to each other.
ISHIWATARI TETSUYA
KANEMURA EISAKU
| JP2002021768A | 2002-01-23 | |||
| JPH0674197A | 1994-03-15 |
Ryoji Kosugi
Tetsuya Hirosawa