TPC centrifugal compressor impeller effectively compress large volumes of hydrogen gas

Source | Greene Tweed

This thermoplastic composite (TPC) impeller manufactured by Greene Tweed (Kulpsville, Pa., U.S.) is a clean technology enabler, facilitating the compression of pure hydrogen (H₂) gas. The centrifugal compressor impeller makes it possible to compress large volumes of undiluted H₂ gas, enabling effective distribution, storage and use in transportation and industry.

Metallic impellers are unable to efficiently compress such lightweight gases due to their lower strength-to-weight ratios compared to composites, which lead to higher centripetal forces for a given peripheral speed.

Manufactured in Greene Tweed’s Swiss facility, the complex geometry of this closed impeller is achieved via a modified and multistep compression molding approach using a pre-impregnated unidirectional carbon fiber-reinforced PEEK material. The use of Hirth coupling — a type of mechanical connection that exploits interlocking, tapered teeth — at the attachment point eliminates potential stress concentrations and CTE mismatch. Tip speeds of more than 680 meters/second were recently demonstrated on a 300-millimeter-diameter prototype, a result of its optimized design and high specific strength.