Left-hand versus Right-hand Impellers
What is an easy way to identify the difference between a left-hand and right-hand impeller? The table below gives a quick summary:
| Method | Left-hand Impeller | Right-hand Impeller |
| View blades from the side | Blade tip is angled upward to the left, like a backslash \ | Blade tip is angled upward to the right, like a forward slash / |
| Right hand palm down, touching thumb on hub or shaft | Blade angles downward towards fingertips | Blade angles upward towards fingertips |
| Pumping direction when rotating clockwise (viewed from top) | Downward flow | Upward flow |
An additional difference is availability – the vast majority of stirring impellers offered on the market are left-hand. If it is not specified, the general assumption is the impeller is left-hand. Suppliers usually identify right-hand impellers, but with the tips provided here you can identify the hand of most impellers from the image.
It is useful to know that any left-hand impeller can mix as a right-hand impeller if the rotation direction is reversed to counter-clockwise. The corollary is also true for right-hand impellers.
|  |
Left-hand Impeller | Right-hand Impeller |
Caframo offers one of the widest varieties of impellers at the laboratory scale, and provides the left-hand configuration for propellers and the pitched blade turbine. To achieve the versatility of both hands from an impeller, the Reversing Digital 2010 is able to rotate in either clockwise or counter-clockwise direction continually, or in both directions in an easy-to-program timed sequence. Contact us to identify the stirrer and impeller best suited for your application.
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References:
Hand. (n.d.) In Glossary of Mixers and Mixing Terms. Retrieved from http://jonesmixers.co.za/glossary-of-mixers-and-mixing-terms/
Indco Inc. (2012, Aug 27). How to determine a Left Hand vs Right Hand Propeller. [Video file]. Retrieved from https://www.youtube.com/watch?v=Qa1Y1vPop00
Mirro, R., and Voll, K. (2009, Jan 1). Which Impeller is Right for Your Cell Line? BioProcess International. Retrieved from http://www.bioprocessintl.com/analytical/cell-line-development/which-impeller-is-right-for-your-cell-line-183538/
Mixer Direct. (2014, Jul 29). Right Hand vs. Left Hand Impeller. [Video file]. Retrieved from https://www.youtube.com/watch?v=F80P0nEdFlM
The Prop Shop. (2016, Mar 23). Simple way to tell if prop is right hand or left hand rotation. [Video file]. Retrieved from https://www.youtube.com/watch?v=8Lskifpbzbo
