Rotor Design Solutions Ltd (RDS), co-funded by the UK’s innovation agency, Innovate UK, are developing a new design concept that will improve upon current screw expander technology that generates green electricity from waste steam pressure.
Approximately one quarter of energy usage is by the Industrial sector in the UK, with around half of this wasted as heat. Steam is the natural bi-product of many Industrial processes and those that do not use steam may use the waste heat via a boiler or heat exchanger to create steam. This can be passed through a screw expander to generate electricity. Currently, screw expander machines are either gear driven with no rotor contact or have contact along the full length of the helical section of the rotors. RDS patent pending technology is based around the principle that two rotors, encased within a housing, are intentionally manufactured to ensure there are defined areas of contact and non-contact for the threaded section of the rotors. At the high temperature inlet end, the rotors will be designed to have a gap between them, so they do not touch. As there is no contact between the rotors, there can be no contact damage. As the steam is expanded, there is an associated temperature drop and change of phase from gas to liquid. From this point onwards, contact of the rotors is permitted and the process fluid provides a lubricating film that reduces friction, heat, and wear within the machine.
“We are delighted our technology has been supported by Innovate UK as part of the Energy Catalyst programme,” comments Dr Dan Davey, Director of Rotor Design Solutions Ltd. “Our concept will allow the removal of timing gears and the associated lubricating oil, for a cheaper, cleaner, reliable machine.”
16th July 2018. Jo Davey, Director, Rotor Design Solutions Ltd