DriveTechnology From SEW-EURODRIVE Keeps The Clean Water Flowing
Water is life. Which is why any process that recycles waste water plays a major role in ensuring the health and well being of our planet. Sewage treatment plants the world over clean up millions of tons of waste water each day; and to do that a plant must be continuously moving; its electric drives must function reliably at many points, and technical glitches and system failures are to be avoided.
The German automation giant SEW-EU-RODRIVE offers a portfolio of drive technology solutions for sewage treatment plants. Catering to every purification stage, SEW-EU-RODRIVE technologies are customized for individual requirements.They significantly lower the plant’s energy requirements and are highly reliable for continuous operations.
Solutions at every stage.
The use of gearmotors in waste water technology is remarkably varied. SEW-EURODRIVE’s wide array of helical, helical-bevel and parallel-shaft helical gearmotors offer the right drive for each stage and environment. These dependable products offer wear-free gearing, space-saving installation, robustness and lowered energy needs. By providing the right product at the right place, and supporting with the right service solutions,the company ensures lasting and reliable system availability.
Here’s how SEW-EURODRIVE’s drive technology offers water treatment plants the right support at every stage of the purification process:
(A) Infeed with screw pump-Upon reaching the plant the waste water is lifted by the screw pumps in the infeed to sewage treatment plant level, for which a motor is coupled to the gear unit via a belt. The mechanical cleaning begins. The drive unit consists of a SEW-EURODRIVE X-series helical gear unit with motor adapter and AC motor.
(B) Screening system and wash press feed-The waste water in the screening system is first coarsely cleaned and larger solids removed. Next, the filtered substances are transported by screen cleaners for further processing. SEW’s parallel-shaft helical gear units are used in combination with an AC motor. Designed slim, these use very less space and are meant for long-term use.
(C) Screening treatment- The wash press is fed directly through the screen or using a conveyor. A solid shaft screw then moves the screenings into the wash area, where faecal matter is removed with a washboard and friction process.
Then water is separated out in the pressing zone. This process uses SEW-EURODRIVE parallel-shaft helical gearmotors and helical-bevel gearmotors and frequency inverters.
(D) Sand trap with scraper and grit classifier- The flow-rate of the waste water is slowed in the sand trap, allowing the heavier materials to settle. These are pressure fed into the grit classifier, where the tangential inflow makes the water rotate, so that heavy materials sink into the funnel tip. SEW-EURODRIVE’s helical-bevel gearmotors are most used in the sand trap, as the gearing is designed for high-torque drives for long continuous usage, and are wear-free.
(E) Primary sedimentation with scraper-Since the waste water flows very slowly, even light particles could settle in the primary clarifier. For these to settle, the flow-rate must be reduced to 0.015 m/s. SEW-EURODRIVE’s helical-bevel gearmotors are used in primary sedimentation, and they are durable enough to be near wear-free even in continuous operation.
(F) Final sedimentation with scraper-Further flow-rate reduction enables sedimentation of settleable substances, and saturated microorganisms settle in the final clarifier. This sludge is pushed, along with a slide feed, and discharged through a funnel in the middle of the basin. SEW-EURODRIVE’s helical-bevel gearmotors are used here as they are ideal for moving heavy loads over long time periods.
(G) Digestion tower-Some sewage sludge is the unavoidable by-product of any waste water treatment process. This sludge produces gas in the digestion tower, which is converted into heat. For an optimal digestion process, the temperature in the tower must be kept at 36 to 37 degrees. Compact drive solutions are needed, which is why SEW-EURODRIVE’s parallel-shaft helical gearmotors are often used at this stage. For today, tomorrow and the day after.
SEW-EURODRIVE provides comprehensive engineering support and advice towards the selection of the most effective drives and solutions. The company also offers customized products and services, and partners its clients throughout the plant’s lifecycle. This is delivered via an extensive service network and a team of highly qualified experts for assistance at all stages from the orientation phase to the commissioning and the modernization of any sewage treatment plant.