This unit has been designed to demonstrate the hydraulic characteristics and settling efficiencies of a model settling basin. Although scale-up to industrial size sedimentation tanks is difficult, relevant deductions can be made as to how nonuniform flows occur and how these interact with the settling characteristics of particular suspensions.

Description

The W7MkII has been designed to demonstrate the hydraulic characteristics and settling efficiencies of a model settling basin. Although scale-up to industrial size sedimentation tanks is difficult, relevant deductions can be made as to how nonuniform flows occur and how these interact with the settling characteristics of particular suspensions.

Water is taken from the laboratory mains supply and is fed to the settling tank via a flow meter. For studies of sedimentation, slurry is prepared in a sump tank and pumped via a specially designed flow meter to join the fresh water stream just before entry to the settling tank.

Well-mixed slurry of known concentration and flow enters the tank uniformly under the inlet weir. This may be comparatively analysed by using Armfield sedimentation studies apparatus (W2-MKII) or the Imhoff cone technique.

The sump tank is continually agitated by a flow sparging device to prevent settling of solids during an experiment.

For hydraulic tracer and visualisation studies, an accurate dye injection system is provided. A known volume of dye solution is injected just before the entry to the settling tank.

• Measuring flow short circuiting and dead space using a tracer
• Comparison of real flow regimes with idealised flow models
• Effect of flowrate and baffle position on dispersion
• Measuring sediment removal efficiencies and relating these to hydraulic characteristics
• Effect of solid concentration on separation efficiency
• Use of the Imhoff cones for analysis

Features & Benefits

• Metal framework with clear sedimentation tank
• Flow sparge device in the tank to keep slurry in suspension
• Operational manual with teaching exercises

Technical Specifications

Sedimentation tank:  97L
Acrylic settling tank: 1.05m x 0.35m x 0.2m
Feed tank capacity:   120L
Sediment flowmeter range: 0 – 2 L/min
Water flowmeter range:       0.5 – 5 L/min
Pump flow rate:                    60 L/min @ 15m head