A new pneumatic bearing dynamometer for power input measurement in stirred tanks
✍ Scribed by Roberto Reséndiz; Alfredo Martínez; Gabriel Ascanio; Dr. Enrique Galindo
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 367 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0930-7516
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✦ Synopsis
A turntable dynamometer has been constructed for the accurate measurement of power input and mixing applications in bench stirred tank reactors. The main feature of this device is a pneumatic bearing with complementary conical parts. The conical pneumatic bearing permitted to apply eccentric loads without affecting its stability. The static friction torque in the pneumatic bearing was very small, 4 x Nm, and can be neglected in the experimental ranges of measured torques, i.e. from 5 x to 2.21 Nm. In accordance with the instrumentation used, the deviations obtained with the apparatus are less than 10% at low torque readings. At moderate torques, deviations lower than 1 % are routinely obtained. Several power input measurements show that the obtained data scatter is lower than 2.5 % . The power input response in the turbulent regime is in agreement with dimensional analysis: the power input depends on the cube of the impeller speed. In addition, data obtained with a turbine impeller under ungassed conditions agree with the predictions of a published correlation, which takes into account several geometrical parameters.