The 3rd Global CemPower Conference on electricity issues in the global cement industry has successfully taken place in London on 1-2 June, with delegates from 18 countries and representatives of over half a billion tonnes of cement production capacity in attendance.
The Global CemPower Conference is unique in cement industry meetings worldwide in that it concentrates on the latest trends in power economics for the industry, including the use of waste heat recovery, electrical energy efficiency measures, grinding efficiency, alternative power sources and captive power generation. Delegates rated the conference very highly for its technical content and its usefulness for making contacts.
Darren BryantÂ of Heatcatcher spoke about approaches to mitigate the operational risk of ORC-based WHR systems. Darren spoke about a 0.5MWe ORC system that the company built for what is now Lhoist (and which was previously Steetly Dolomite) at the Thrislington lime works in the UK. Four 125kW containerised ORC generators with condensers were installed, producing 448kW (net). Electric fans are used for the air-cooled condensers, with lower power requirements. Gas comes to the heat exchanger after the EPS, so dust load is relatively low, although there are still issues with dust build-ups. Sonic horns were latterly applied to deal with dust issues, after a brush cleaning system became inoperable due to heat exchanger tube issues. Darren mentioned some other lessons learned from the project: On a preheater WHR system, the consistency of the dust can be crucial to project success or failure. The system must be 100% isolated from the process, while the boiler must be designed for minimal pressure drop. A hammering system is the most-used system for dealing with dust in the heat exchanger. With an AQC boiler, the dust is typically dry but abrasive, and the location of the WHR system take-off is critical, with come locations giving a 30% improvement in system capacity compared to others. Dust load from the cooler can be reduced with a gravitational de-duster or cyclone, but the pressure drop in the system must be minimised to reduce â€˜parasiticâ€™ energy losses. A cost of around Euro3m/MW was achieved with the system at Thrislington, but Darren said that lower costs must be achieved if these systems are to be widely adopted.