Free Floating Piston (TM) technology - a new development to increase the life of reciprocating compressor wear bands

Far large horizontally opposed compressors, changing process and requirements are dictating the increased use of non-lubricated cylinders. sometimes unpredictable life of piston wear bands remains an elusive goal. Thomassen, a manufacturer of such machines, wished to achieve a consistent and substantial improvement in wear band life. To achieve this goal, a radical approach was attempted. A feasibility study to evaluate alternative bearing forms for pistons, left magnetic and gas bearings as main candidates, The gas bearing proved ultimately to be the more attractive option. A calculation model was developed, and verified on a static test rig. After successful static trials the design was incorporated into a full size, heavy duty test compressor. Inspection after 2000 hours of operation revealed only traces of bedding-in wear on the wear bands. The Free Floating Piston(TM) technology may be used in almost all compressor applications, with all types of process gas, with virtually no wear of wear bands. It can easily be retrofitted to existing machines by virtue of its self contained design.At present a FFP(TM) technology equipped hydrogen compressor is in full time operation in the Netherlands. Financial assistance for this final phase was provided by the Netherlands Ministry of Economic Affairs. The design has been filed for patents in a number of countries around the world. This paper describes: A summary of the gas bearing technology. Application in a reciprocating compressor. Design. Testing and test results. Research path.