Many wastewater applications will include one or more tanks for liquid storage. With liquids containing particles, wall sedimentation is a common problem if liquids are maintained at fixed levels when filling and emptying the tank.
ABB's drive modules for water and wastewater treatment include a special level control function designed to prevent sediment build-up. Incorporating all functions commonly required at pumping facilities, these modules help eliminate the need for an external PLC and can help to save energy, reduce downtime, and prevent pump jamming and pipeline blocking.
The level control function enables the drive to be used to help control the filling or emptying of waste water storage tanks. Level control eliminates the need for a control valve, bypassing piping and the subsequent energy losses. The level of the water tank can be controlled using PI control to maintain smooth but accurate level control with one or several pumps running in parallel.
How does the software help prevent tank wall sedimentation?
A special feature of the software helps prevent sediment build-up on the tank walls by randomly varying the surface level within a range preset by the user. Fast-ramp starting creates a flush effect to keep pipelines clear, and the pump is operated at a favourable point in its efficiency curve to minimize energy consumption. Level control can be used with a single pump, or two to three pumps and AC drives in parallel.
Key benefits of ABB's level control functions
- Reduced maintenance costs of the tanks
- Improved safety of staff
- Control over pumps keeping the system operational at all times
- Correct water level maintained within the tanks
- Stable process conditions in the treatment plant
For more information, please click on either of the links below: