In sedimentation tanks, solids are separated out from suspensions under the influence of gravity. In this process the density of the solid particles must be greater than that of the liquid. It makes it possible to investigate the separation of solids from a suspension in a sedimentation tank.
First a concentrated suspension is prepared in a tank, comprising water and the solid to be separated. A pump transports the concentrated suspension to the sedimentation tank. Upstream of the sedimentation tank the suspension is mixed with fresh water. The raw water generated in this way flows into the sedimentation tank via an inlet weir. A stirring machine is located upstream of the inlet weir. This prevents solids sedimenting before entering the sedimentation tank. The treated water first flows under a baffle and then over a weir to the outlet.
Learning Objectives And Experiments
- Bed-load transport in open channels
- Subcritical and supercritical flow
- Formation of ripples, dunes and antidunes
- How flow velocity affects bed-load transport
- Fluvial obstacle mark (siltation/scour formation)
- Bridge pier
- Sluice gate
- Visualisation of the flow
- Open-channel flow without sediment transport
- Subcritical and supercritical flow
- Control structure: sluice gate
- Discharge measurement on the sharp-crested weir
Specification
- Separation of suspensions by sedimentation in the sedimentation tank
- Transparent sedimentation tank with lighting for visualisation of the flow conditions
- Stirring machine in the inlet area of the sedimentation tank
- Lamella unit can optionally be inserted into the sedimentation tank
- Tank with pump and stirring machine to create and transport a concentrated suspension
- Mixture of the concentrated suspension with fresh water gives the raw water to be studied
- Adjustment of the concentration of solids via valves for fresh water flow rate and suspension flow rate
- Adjustable water level in the sedimentation tank and adjustable flow velocity in the inlet
- Electromagnetic flow rate sensor for raw water
- Lmh off cones for determining settleable substances of a water sample
Technical data
- Sedimentation tank (experimental section)
- Lxwxh: 900x110x300mm
- Max. Filling capacity: approx. 25L
- Material: plexiglass
- Lamella unit
- Angle of inclination of lamellas: 60°
- Number of lamellas: 16
- Suspension tank
- Capacity: approx. 85L
- Material: stainless steel
Pump
- Max. Flow rate: 75L/h
- Stirring machines (max. Speed)
- Suspension tank: 600min-1
- Sedimentation tank: 330min-1
Measuring Ranges
- Flow rate: 30…600L/h
- 230V, 50Hz, 1 phase
- 230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase
