A320 and A340
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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
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| 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. |
| Re |
Np |
Nq |
theta N |
discharge angle |
Notes |
| 1 |
42 |
|
|
90 deg |
T = 17.5"
Z = 12.0", Z/T = 0.69
D = 6.0", D/T = 0.34
OB = 3.0", OB/D = 0.5
4 baffles
Fluids: 96% Glycerine and Carbopol |
| 10 |
5.5 |
|
5500 |
90 |
| 30 |
2.7 |
|
850 |
70 |
| 100 |
1.7 |
|
210 |
55 |
| 300 |
1.2 |
|
40 |
27 |
| 1000 |
0.85 |
|
10 |
0 |
| 3000 |
0.74 |
|
|
0 |
| 10000 |
0.68 |
|
|
0 |
| turbulent |
0.64 |
0.64 |
|
0 |
Reference The data above was
extrapolated from graphs in the reference.
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