| 摘要 |
<p>This invention relates to a drive system suitable for driving a rotary arm arrangement of a sewage treatment bed, and a method of operating such a system. The drive system comprises a rotary part 16 to be rotated; a drive wheel 22 in driving engagement with the rotary part 16; an electric motor 24 for driving the drive wheel 22; an auxiliary power means, namely a rechargeable battery; and a power control means for automatically switching, in the event of a mains power supply outage, from power from the mains power supply to power from the auxiliary power means. The drive system is preferably a belt drive.</p> |
