| 摘要 |
PURPOSE:To reduce and maintain the deformation of an impeller due to changes in temperature within a specified allowable range by a method wherein the impeller is divided into two or more pieces together with a casing and coaxially arranged in the axial direction. CONSTITUTION:An impeller 7 of a fan 6 is divided into two, for example, together with a casing 8 and coaxially arranged in the axial direction, so that the length of each impeller 7 decreases to half, compared with a conventional long single impeller which has a length almost equal to the inside length of a thermohydrostat chamber. Therefore, when a motor 13 is started to turn the impellers 7, their rigidity remarkably increases in the case the impellers 7 are the same in diameter, and the amount of deformation of the impellers 7 in rotation decreases considerably, compared with the conventional single impeller. Deformation of the impellers 7 due to changes in temperature cant be reduced and kept within a specified allowable range without a decrease in capacity if the total length of the impellers 7 is equal to the the length of the conventional single impeller. |
