Extensional Flow Mixer for Viscosity Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mixing systems face challenges in efficiently mixing fluids with varying viscosities, particularly in laminar flow conditions, where high viscosity bulk streams and low viscosity additive streams remain segregated due to low interfacial contact, leading to slow mixing rates and issues like polymer build-up and pressure loss.
Innovation Solution
A mixing system comprising an extensional flow mixer with contoured lobes that compress and broaden the streams to increase interfacial area, followed by helical static mixing elements, which enhances the dispersion and mixing efficiency of the additive stream within the bulk stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high shear forces are applied to promote mixing of high viscosity bulk stream and low viscosity additive stream, then mixing rate improves, but the streams remain segregated due to viscosity differences
Solution Approach 1:
The patent changes the flow regime parameter from laminar to turbulent by controlling Reynolds number, enabling effective mixing of streams with vastly different viscosities. The turbulent flow creates chaotic advection that overcomes the stabilizing effect of viscosity differences, allowing high mixing rates while preventing stream segregation.
2Loss of energy
If additive stream is injected into bulk stream in laminar flow, then pressure loss is minimized, but mixing occurs slowly by diffusion
Solution Approach 1:
The patent transitions the flow regime from laminar to turbulent by adjusting the Reynolds number parameter. This parameter change enables rapid mixing through turbulent eddies and chaotic advection, achieving high mixing rates without the excessive pressure losses that would result from mechanical mixing devices.
3Productivity
If additive stream is injected from within static mixer, then mixing is promoted, but polymer build-up occurs at contact points
Solution Approach 1:
The patent extracts the additive stream injection point from the interior of the static mixer and places it upstream in the bulk stream flow. This spatial separation removes the additive injection system from contact with the polymer bulk stream, eliminating the polymer build-up and plugging problem while still achieving effective mixing through the subsequent turbulent flow regime.
Solution Approach 2:
The patent introduces turbulent flow as an intermediary mechanism that enables mixing without direct contact between the additive injection system and the polymer bulk stream. The turbulent eddies and chaotic advection act as a mediator, transferring momentum and mixing the streams without requiring physical contact points that would lead to polymer deposition.
4Area of stationary object
If baffle structures are used to promote mixing, then interfacial area increases, but recirculation zones and eddy currents decrease mixing efficiency
Solution Approach 1:
The patent inverts the conventional approach to mixing enhancement. Instead of using solid baffles to create interfacial area, it uses turbulent flow structures (eddies and chaotic advection) to achieve mixing. This inversion replaces stationary geometric features with dynamic flow features, eliminating recirculation zones while maintaining high interfacial area through turbulent mixing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system significantly improves the mixing efficiency by increasing the interfacial area between the bulk and additive streams, reducing polymer build-up, and minimizing pressure loss, resulting in faster and more effective mixing of fluids with varying viscosities.
Implementation Method 1
an extensional flow mixer with contoured lobes that compress and broaden the streams to increase interfacial area
Implementation Method 2
deforming the additive stream from the cylindrical shape the additive stream initially has, to a relatively flat sheet having more surface area
Implementation Method 3
followed by helical static mixing elements, which enhances the dispersion and mixing efficiency of the additive stream within the bulk stream
Data Source
AI summary
The invention provides a mixing system comprising the following:A) at least one extensional flow mixer comprising:a generally open and hollow body having a contoured outer surface and having:a single entrance port and a single exit port;a design for compressing a bulk stream, anda design for broadening the bulk stream and the at least one injected additive stream;B) a flow conductor; andC) a primary additive stream injector, as described herein; andwherein the extensional flow mixer is followed by D) a first helical static mixing element that is at least one half “flow conductor diameter (D1)” downstream of the exit port of the extensional flow mixer; andwherein the mixing system comprises at least four helical static mixing elements, placed such that the leading edge of the first helical static mixing element is located perpendicular to the main axis (major axis) of the exit port of the extensional flow mixer.