Floating decanter for SBR plants

Decants clear water from below the surface with no drive in the tank. All stainless steel 316Ti, designed to DWA‑M 210. Two weighted flaps open passively during decanting and stay sealed during aeration and mixing.

Rotaria KWA in an SBR tank: oval stainless steel float with decanting chamber, rigid stainless steel outlet pipe with swivel joint to the tank wall, a mixer alongside.

Design

Type	floating decanter with decanting chamber and two weighted closing flaps
Drive in/on the tank	none
Control	motorised valve in the outlet chamber or decant pump
Design basis	German DWA-M 210 guideline for SBR plants
Frost protection	down to -20 °C (support structure below the bottom water level)
Outlet pipe	rigid stainless steel pipe with swivel bearings at the tank wall
Fault protection	floor stand limits the lowest position
Commissioning	filled and vented via ball valves while the tank is filled
Float, decanting chamber, outlet pipe, supports	stainless steel 1.4571 / AISI 316Ti (alternatively 1.4404 / 316L)
Seals	EPDM
Float	welded stainless steel

Sizes

We build the Rotaria KWA for decant rates from 90 to 800 m³/h and size it precisely to your tank.

Supplied so far: 90, 100, 105 and 387 m³/h, DN 100 to DN 300, tank depth 5 to 6 m, water level variation approx. 1.5 to 1.9 m.

Dimensions, example 387 m³/h

Float (L × H)	2,600 × 400 mm
Decanting chamber, length	1,512 mm
Inlet slot (L × H)	1,300 × 160 mm
Top of inlet slot	158 mm below underside of float
Overall height of decanter head	1,111 mm
Outlet	Ø 323.9 mm (DN 300)

Dimension drawing of the 387 m³/h decanter head: float 2600 mm long and 400 mm high, decanting chamber 1512 mm with inlet slot 1300 by 160 mm, outlet diameter 323.9 mm, overall height 1111 mm. — Decanter head 387 m³/h, dimensions in mm

Suitable for

Municipal and industrial SBR plants
Retrofitting existing SBR tanks
Tanks from about 4 m deep
Water level variation up to approx. 1.9 m
Decant rates from 90 to 800 m³/h
Outdoor installation down to -20 °C

Not suitable or to be checked

Tanks without a motorised valve or decant pump for control
Water level variation above approx. 1.9 m
Very shallow tanks under about 4 m
Decant rates above 800 m³/h
Tanks with a very thick scum layer

Options

Holder for an MLSS/TSS probe on the float, removable from the tank edge, adjustable immersion depth
Pressure sensor with protective tube
Guide rails
Flexible hose connection

Tender specification and sizing: products.rotaria.com/en/sbr-decanter/ · info@rotaria.com