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| Paraflow Distribution |
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Paraflow Distribution Head
This distribution head was designed to minimize the residence time required for mixing. The low viscosity additive and main polymer follow internal parallel paths. The exit pattern of the additive is like that of the honeycomb of the bee.
The low viscosity additive and main polymer follow internal parallel paths. The exit pattern of the additive is like that of the honeycomb of the bee. This generates an enormous improvement in the A/t value.
This means that if there are N main product holes say, 42 and the additive fraction is 1% then A/t = 106,000.
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VISCOSITY AND PRESSURE DROP CONSIDERATIONS
Most polymeric materials are shear sensitive. That is to say, their viscosity is dependent on the shear rate to which they are exposed. Usually an increased shear rate produces a lowering of viscosity and is referred to as shear thinning. Viscosity versus shear rate data is usually provided by the polymer manufacturer in the form of a graph on log/log paper. We list below the shear rate and pressure drop formula for each of the devices we have described and others together with the units involved.
Main pipe inside diameter = D inches
Main product flow rate = Q gpm
Shear rate = g sec-1
Viscosity = m cP
Pressure drop = dP psi
Axial length = L inches
Additive fraction = F
Number of mixing elements = n |
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| Device |
A/t Value |
Shear rate |
Pressure drop |
Comments |
| Open pipe |
---------- |
39.2Q/D3 |
22.73x10-6Qm L/D4 |
Hagen-Poiseuille Equation |
| Helix |
np |
96.0Q/D3 |
205x10-6Qm n/D3 |
Helix L/D ratio = 1.5:1 |
KOMAX SYSTEMS, INC.
INTRODUCES
A NEW STATIC MIXER SYSTEM
FOR HIGH VISCOSITY PRODUCTS
(U.S. Patent 5,484,203)
 A Single Injection Point allows pressurized clearing action from the additive pump if needed. The built in check valve prevents back flow of polymer into the additive supply.
The PARAFLO Injector distributes additive across the inlet of the ULTRA mixer. It is less than one pipe diameter in length and has a low pressure drop.
The ULTRA Mixer generates multiple interstices with a uniform spatial distribution to give 100% utilization of the mixer volume and superior additive dispersion with low pressure drop.
| Device |
A/t Value |
Shear rate |
Pressure drop |
Comments |
| L/H unit |
8/p2 F |
215Q/D3 |
5.9x10-4Qm /D3 |
Each hole dia. = 0.45D |
| H/L unit |
3.6/F |
81.7Q/Dt2 |
22.1Qm L/Dt3 |
Where annulus dia.= 2D/3 |
| SIDD |
288/p2 F |
593Q/D3 |
12.6x10-4 Qm /D3 |
Each hole dia. = 0.3D |
| PARAFLO |
8pN/F |
Contact factory for shear rate and pressure drop calculations. |
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