BSK® - Decanter
Clear Water Discharge
High efficiency, reliable design for Clear Water Discharge
No risk of clogging because of floating or activated sludge
Maintenance-free, corrosion-proof components. No wear parts under water
Advantages
Unique Hydraulic Design
Equipment designed and developed by Biogest International® GmbH. Remarkable high discharge volume - even for small diameters of the pipe.
Adjustable discharge volume
Two different discharge modes allow the end-user to adapt the water flow according to the specific project conditions.
Made of stainless steel
No material is better than stainless steel in the waste water: No corrosion and almost unlimited lifetime. Free choice of alloy is possible (AISI 304L, 316L etc.).
Hard-wearing gear drives
Dry mounted robust drive system with comfortable access. Well-proven technology, viable under heavy operating conditions, protected by an additional weather hood.
Fast and easy installation
Simple and prefabricated parts allow for quick assembly.
No extraction of floating or activated sludge
Efficient barrier for floating sludge by the baffle plate.
Maintenance-free, corrosion-proof components
No wear parts under water. Lifetime lubricated swivel joints (rotating links).
Low operation costs
Minimum energy consumption, gravity discharge of clear water.
Structure of the BSK®-Decanter
- Local switch box
- Electrical winch
- Lifting rope, stainless steel
- Air vent valve
- Air vent pipe
- Conductive sensor
- Inlet pipe
- Sludge baffle / barrier for floatings
- Connection pipe
- Swivel joint / rotating link
- Concrete wall
- Catching rope, stainless steel
- Discharge of cleared wastewater
- Maximum water level
- Minimum water level
- Sludge level
Function of the BSK®-Decanter
- Parking position:
- The parking position is the highest position the decanter can achieve, at a level set by the design
- The parking position (just above the maximum water level) also acts as an emergency overflow
- Equipped with a maintenance-free submerged swivel joint, the BSK®-Decanter can be lifted or lowered by an electric winch depending on the water level
- Hydraulic optimized openings in the inlet pipe of the BSK®-Decanter provides smooth and constant flow, without turbulences
- Downward movement:
- The stainless steel inlet pipe is lowered to the water by an electrically operated winch
- When the inlet pipe reaches the surface of the water, the floating sludge is pushed and held aside by a sludge baffle, without the possibility of entering the inlet openings
- Specially designed openings in horizontal inlet pipes guarantee symmetrical entry of treated waste water
- Decanting phase:
- Any downward movement will be reliably stopped before reaching the activated sludge blanket level
- After reaching the preferred water level, the BSK®-Decanter moves back to its preset parking position
- The operation of the BSK®-Decanter is realized by two limit switches, secured by two additional limit switches as well as one emergency limit switch
Applications of the BSK®-Decanter
Wastewater treatment
- Activated sludge treatment - Clear water discharge in SBR plants
- Secondary decay (Clarification) - Discharge of floating sludge (special model)
- Sludge Thickening - Discharge of supernatant
Biogas plants
- Sludge conditioning - Discharge of supernatant
Water treatment
- Surface skimming - Discharge of floating material
BSK®-Decanter of WWTP Stepanovicevo, Serbia
Types and Sizes
Available Dimensions and Hydraulic Capacities
BSK®-Decanter is used in 7 different standard sizes (pipe diameters), ranging from DN 100 to DN 400. For normative application (WLmax, WLmin, head loss = 1.0 m) the following capacities of each size apply:
Basic Configuration
Manufacturing is possible using different types of stainless steel and components:
- Material: stainless steel AISI 304 or AISI 316
- Motor capacity: 0.12 - 0.37 kW
- Rope speed: 0.5 m/min
- Stainless steel housing for weather protection
- Optional: Dip-in sensor
- Local control box
More optional extras are available.
Discharge of Clear Water or Supernatant
Typically, the DCW model is used in SB-Reactors as a complete automatic discharge system, while the DSC model offers special advantages for sludge thickening - it works mainly manually.
Each BSK®-Decanter is specially adapted to its individual application.
References
BSK®-Decanters are in operation worldwide.
Some examples are shown below
More details in our presentation brochures:
BSK®-Decanter for SBR systems 
BSK®-Effluent Decanter
BSK® is a registered trademark of Biogest International® GmbH