Enclosed Drum Mixer for Boundary Layer Mixing
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Solution Overview
Problem
Existing mixers, such as open-impeller designs, require disassembly, can damage vessels, cause aeration, and inefficiently mix liquids, especially in large volumes and at the boundary layers, and are not suitable for narrow ports or low-level mixing.
Innovation Solution
A completely enclosed mixer with a tubular frame for strategic media distribution, featuring rotating and static impeller assemblies that induce axial and radial flows, eliminating the need for rigid mounting and minimizing energy consumption and aeration, and allowing operation through small vessel ports without disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If open-impeller mixers are used to mix liquid media, then mixing action is provided, but the mixers require disassembly to pass through vessel ports and may cause aeration
Solution Approach 1:
The enclosed mixer design features a nested structure where the impeller assembly is contained within a cylindrical housing that can be inserted through narrow vessel ports. The entire mixing apparatus fits within a compact envelope that passes through the port, then expands to fill the vessel volume, eliminating disassembly requirements while maintaining mixing effectiveness.
Solution Approach 2:
The mixer is divided into functional segments: a drive mechanism, an enclosed impeller assembly, and a distributed outlet system. This segmentation allows the mixer to pass through narrow ports as a compact unit while still providing comprehensive mixing coverage throughout the vessel when deployed.
2Productivity
If open-impeller mixers are used, then mixing is provided from a centralized point, but energy consumption increases and boundary layer mixing is inefficient
Solution Approach 1:
The mixer employs multiple distributed impeller assemblies positioned at different locations within the vessel, including near the base and along the walls. Each impeller creates localized flow patterns that collectively provide comprehensive mixing throughout the entire vessel volume, with particular attention to boundary layer regions where traditional centralized mixers fail.
Solution Approach 2:
The mixing action transitions from a single centralized vertical flow to a three-dimensional distributed flow field. Impellers are positioned to create radial, axial, and tangential flows simultaneously, ensuring thorough mixing throughout the vessel volume while reducing the energy required per unit volume mixed.
3Reliability
If open-impeller mixers are rigidly mounted, then stable operation is achieved, but the mixers cause aeration and cannot reach low-level media
Solution Approach 1:
The harmful aeration effect is eliminated by removing the open impeller design that exposes rotating blades to the liquid surface. Instead, the impellers are enclosed within sealed housings that prevent air from being drawn into the liquid, completely eliminating foam and aeration while maintaining effective mixing action.
Solution Approach 2:
The mixer employs adjustable and reconfigurable impeller positions that can be dynamically adapted to different vessel configurations and liquid levels. This dynamic positioning capability allows the mixer to reach low-level media without requiring rigid mounting, while the enclosed design prevents aeration regardless of position.
4Adaptability or versatility
If open-impeller mixers are used, then mixing action is provided, but the mixers cannot be easily relocated between vessels
Solution Approach 1:
The enclosed mixer design features a universal mounting interface that can be quickly installed and removed from various vessel types without requiring complex bracketry or permanent mounting structures. The self-contained enclosed housing serves as both the mixing mechanism and the mounting interface, enabling easy relocation between vessels while maintaining operational stability.
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 enclosed mixer design efficiently mixes liquids throughout the vessel volume with minimal energy and aeration, effectively reaching all areas, including boundary layers, and can be easily relocated between vessels without damaging the vessel.
Implementation Method 1
a first array of rotating and static impeller assemblies that induce an axial flow of the liquid media through the tubular frame
Implementation Method 2
a second array of rotating and static impeller assemblies that induce a radial flow of the liquid media outwardly from the tubular frame
Implementation Method 3
The mixer uses a strategic ducting of liquid through its tubular frame to strategically distribute the media throughout the vessel
Implementation Method 4
Open impeller mixers cannot induce efficient flow at the boundary layers where the liquid media contacts the vessel interior base and interior walls
Data Source
AI summary
The boundary layer drum mixer is an apparatus which can pass through the narrow top port of a standard chemical drum or bulk container without the need to disassemble any part of the mixer or the vessel. The invention is an enclosed system with an internal arrangement of impellers and stators which draw liquid-based media from the adjacent vessel and strategically distributes it throughout the vessel through an array of outlet ports. The strategic mixing requires low energy input, minimizes the risk of media aeration and works with a wide range of fluid levels. The apparatus imparts no net external torque, and therefore, requires no rigid mounting. The upper impeller flow positively entrains particles or liquid phases that tend to float. The lower impeller flow positively entrains particles or liquid phases that tend to sink and/or remain static in boundary layers against or near the vessel walls and base.