Design, Fabrication, and Testing of a 3D Printed Centrifugal Pump

Additive manufacturing offers designers a rapid means of testing ideas. Other advancements in desktop 3D printing have given more power to users by allowing them to reinforce parts with fiberglass, kevlar, and carbon fiber giving parts the rigidity and strength needed for certain projects. These advancements and others like it in 3D printing show promising applications in chemical engineering and other disciplines. Some of these applications include maintenance, as well as in design and testing of new products and process equipment. In this 10 week project, a working and reliable centrifugal pump was designed using Solidworks 3D CAD software. Based on problems associated with previous pump designs such as leaking, a weak impeller drive shaft connection, a lack of assembly rigidity, DC motor damage, and a weak assembly support structure, a new list of design requirements was made. With these new design requirements in mind, a new design was drafted. A MarkForged Mark II 3D printer was used to create viable, watertight, carbon fiber and fiberglass reinforced nylon parts. Preliminary testing of pump prototypes still showed design shortcomings like air accumulation, shaft misalignment, and persistent leaking. However, all these problems were solved quickly using additional 3D printed parts, Solidworks’ Finite Element Analysis tools, changing the assembly orientation to allow air to flow out, using embedded ball bearings, adding gaskets, and using packing to create seals around dynamic parts. After all design requirements were met, pump performance was measured using a testing rig to gather necessary data for a thermodynamic analysis, efficiency calculations, and pump performance curves. With a power input of 4 watts the max head height was 75 cm at a flow rate of 15 mL/s. Also the max flow rate with a power input of 4 watts was 49 mL/s. This testing rig was also used to investigate how different pump impeller shapes and designs effected overall pump performance. Lastly a final bill of materials was calculated with an estimated cost of $282 for this functional prototype. This proof of concept shows the promise, cost effectiveness, time effectiveness, and versatility of additive manufacturing in the design, maintenance, and troubleshooting of process equipment in the specific case of a common engineering application of pumping.