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Impeller: A320 and A340 |
 
A320 Impeller 
A340 Impeller Images courtesy of P. Csiszar |
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The A320 is a patented impeller by Lightnin. It has 3 blades and is called by Lightnin a fluidfoil impeller. It is considered an down-pumping axial flow impeller, because under turbulent conditions the discharge of the fluid is parallel to the shaft (0 degrees). As you can see from the table below, as the Reynold's number decreases the flow discharges at a greater angle. Turbulent Power Number Np=0.64, Flow Number Nq=0.64> The A320 was designed to operate in the turbulent and transitional ranges. The high solidity of the blades makes it work even in very high viscosity. As the viscosity increases and the Reynold's Number (Re) decreases, the starts to become more radial, as do all axial flow impellers. The table below shows the discharge angle as a function of Re. If you flip an A320 upside-down and rotate it counterclockwise, the flow pattern is upward. If the A320 is built to be an up-pumper, but to operate in the clockwise direction, the impeller is called the A340. We think that the up-pumping flow pattern has many advantages. Some people call it and up-draft or an up-flow pattern. The design of up-pumping is so different from down-pumping or down-flow that most people will not be able to optimize it. We will be bringing articles about this soon. In the meantime, look at our references and go to your library for those of you that need to know now. |
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Reference: The data above was extrapolated from graphs in the reference. |
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