Session: 13-03-05: General: Mechanics of Solids, Structures and Fluids V

Paper Number: 166483

The Effectiveness and Utility of Modular Spring-Sleeve Static Mixing Inserts for the Inline Mixing of Fluids in Standard Pipe and Tubing 

Static mixers are critical for achieving efficient inline blending of fluids across various industrial applications, including chemical processing, color blending, water treatment, polymer manufacturing, and laboratory experiments. Traditional spiral static mixers rely on tight tolerances and direct wall contact to assist in effective mixing; these designs can introduce manufacturing challenges and increase installation costs. This study investigates a novel class of modular, 3D-printed static mixing inserts that self-secure within a loosely toleranced pipe using their material elastic properties. As pipe tolerances generously control the outer diameter and thickness, the inner diameter of the same pipe standard size and schedule could vary significantly. Unlike conventional spiral static mixer designs, these inserts maintain a gap within the streamline while preserving near-wall attachment, potentially altering mixing dynamics and pressure drop characteristics.

A combined computational fluid dynamics (CFD) and experimental approach is used to evaluate the mixing performance and hydraulic efficiency of these inserts under controlled laminar flow conditions with a Reynolds number of 1,000 maintained at the inlet. These tests are performed on a custom static mixing test rig fed by two Masterflex peristaltic pumps. Mixing efficacy is quantified using coefficient of variation (CoV) analysis to assess concentration homogeneity, while pressure drop (ΔP) measurements determine the associated energy losses. ANSYS fluent is used to simulate the velocity distributions and ΔP with the latter being compared to experimental values pertaining to system efficiency. CoV is derived from specific gravity measurements taken from the inlet fluids and resulting outlet product fluid.  Comparative studies with standard spiral static mixers provide insight into the trade-offs between mechanical functionality of the insert to mixing efficacy and hydrodynamic resistance. Additionally a dye stream is introduced in a separate component of the experiment for a visual representation of the mixing process.

These experimental findings suggest that the unique flow structures overcome the streamlined gap variation in geometry by induced radial velocity, potentially enhancing mixing without excessive pressure penalties. Differences in pressure drop being less than 5% with no noticeable deviation in homogeneity variance in the byproduct fluid with non-viscous water soluble constituent fluids. The modularity of the inserts enables rapid reconfiguration and optimization for different flow conditions while tailored structural geometries, material properties, and printing parameters allow the designer to control holding force targets at the conduit wall. These results contribute to the broader understanding of non-traditional static mixing geometries and their role in providing alternative mixing solutions. Future work will refine insert geometries based on CFD-driven insights and experimental validation, further improving performance for practical implementation while exploring additional material compositions to enhance durability and chemical resistance.

Presenting Author: Joshua Cagle Georgia Southern University

Presenting Author Biography: Joshua Cagle is a graduate student pursuing a Master’s degree in Mechanical at Georgia Southern University He earned his Bachelor of Science in Mechanical Engineering from the University of Akron and has six years of industry experience, including 5 years at Johnson Matthey, where he worked as a Design Engineer and R&D Engineer. His expertise spans manufacturing support, robotics, product and equipment design, catalyst reactors, gas processing systems, and the manufacturing and design of catalyst substrates. His current research focuses on chemical processing structures, integrating his industry experience with academic study.

Authors:

Joshua Cagle Georgia Southern University
Dr. Mosfequr Rahman Georgia Southern University