Biobull - Fermenter Agitator
Slow-running large-propeller agitators of the Biobull® type enable large quantities of fluid to be circulated in tanks with largely constant fill levels. They are used above all in biogas generation and in other applications with difficult substrates (fibrous constituents, maximum dry matter contents, etc.). The maximum medium temperature is 60 °C. By means of an external agitator column, the agitator can also be used in steel tanks of different shapes and sizes: The forces and moments are not transferred to the tank wall, but into the foundation.
- Propeller diameter 2650 mm or 1500 mm
- Required wall opening Chamber lining 600 x 600 mm or core hole 450 mm
- Required cover opening
- for lifting out the agitator shaft 2200 x 650 mm
- Overall weight approx. 1100 – 1500 kg depending on version
- The height of the bottom-bearing bracket and the length of the agitator shaft are determined by the tank dimensions.
- Parts flushed with gas in the fermenter Stainless steel 1.4571 (V4A)
- Parts outside the fermenter Galvanised or painted/coated
- Base bearing Silicon carbide mechanical seal
- Propeller (Ø 2650 mm) High strength, wear-resistant polymer with steel core
- Propeller (Ø 1500 mm) Stainless steel 1.4301 (V2A)
- ATEX-certified version for use in explosion protection zones 1 and 2
- Frequency inverter with parameterised safety software (torque limiting, coupling break detection, etc.)
- streisal "SafeGuard" (optional): automatic torque monitoring and control system
- Shear-pin coupling as the final predetermined breaking point
By means of an external agitator column, the agitator can also be used in steel tanks of different shapes and sizes: The forces and moments are not transferred to the tank wall, but into the foundation.
The agitators are available with various ATEX ignition protection types for use in explosion protection zones 0, 1 or 2.
With the agitator shaft installed at an inclined angle and two propellers mounted at different heights, the agitators generate significant hydraulic performance with horizontal and vertical flow components. The substrate can flow in without obstruction because the agitating elements are not covered by any obstructive built-in components.
The design of the propeller shape, the large hub diameter and smooth, tangential transition to the propeller blade prevent material from wrapping itself around the blades.
The propeller geometry with its three dimensional profile has been optimised in the fluid mechanics laboratory; this and the large propeller diameters combined with low speeds of rotation mean the agitators generate maximum thrust while drawing very little power. As a result, energy and operating costs are significantly lower!
Serviceability
Important wearing parts are mounted externally and are therefore easy to access for maintenance and servicing. For example, there is no need for the container roof (gas accumulator) to be opened regularly in biogas plants. The agitator shaft is sealed by a gas-tight siphon seal with contactless operation.
The streisal Biobull® has been available on the market for 15 years, and the first models are still in use. This means we can truly validate its long service life!