The waste of electricity at an incineration plant has been overcome by a new variable speed drive.

In a bid to improve its environmental performance, London Waste has updated the process at its incineration facility in Edmonton, North London. An installation by ABB Drives Alliance partner Mid Kent Electrical (MKE) has rewarded the firm with a drop in boiler fan electricity use of over 50%.

London Waste approached MKE to look at improving the process by installing variable speed drives. Fans that bring air into the boilers to aid combustion were driven by 735 rpm slip ring motors running at full speed, with airflow controlled by pneumatically-activated dampers.

After an energy audit, MKE proposed controlling the motor with a 55 kW variable speed drive from ABB, removing the air damper in favour of controlling the speed of the fan motor. To reduce costs, it was requested that the existing motor be used with its slip rings linked out rather than being totally replaced.

An energy audit comparing the old and new control methods showed that energy consumption was cut by over 50%, giving an expected payback of under two years based on current consumption. CO2 emissions have also been reduced by the installation.

MKE supplied a turnkey package with all components, installation and modification to the existing plant. Since the first installation two further drives have been installed, providing greater control and further savings.

Source

Electrical and Mechanical Contractor