Patent DE-102007009451-A1 (DE)
Title: Biogas plant fermenter filled with a substrate, comprises a highly adjustable submersible motorized agitating device, a filling level measuring device, in which the filling level of the substrate is seized, and a control device
Inventor: BUERGER ADAM
IPC: C12M1/02
Filed: 2007-02-27
Abstract: The biogas plant fermenter (1) filled with a substrate, comprises a highly adjustable submersible motorized agitating device (6), a filling level measuring device (15), in which the filling level of the substrate is seized and a corresponding filling level measuring signal is produced as high actual value signal, and a control device, which brings the filling level measuring signal and controls a high actuator for the agitating device with a seized small filling level, so that the agitating device is lowered and the agitator blade is completely immersed in the substrate. The biogas plant fermenter (1) filled with a substrate, comprises a highly adjustable submersible motorized agitating device (6), a filling level measuring device (15), in which the filling level of the substrate is seized and a corresponding filling level measuring signal is produced as high actual value signal, and a control device which brings the filling level measuring signal and controls a high actuator for the agitating device with a seized small filling level, so that the agitating device is lowered and the agitator blade is completely immersed in the substrate. The motorized agitating device with its agitator blade (7) is completely immersed in the substrate. The measuring device comprises a mechanically processing sensor with a floater and/or a displacement body having a position indicator and/or a control switch, and an ultrasonic echo sounding device or a contactless processing gamma emitter with a counter-chain and/or a hydrostatic pipe for a bubbler method. The sensor of the measuring device is fitted at a fermenter cover. The free space height (H 3) seizes between the sensor and the substrate level with a free space height signal, which is supplied to a controller of the control device. The total height (H 0) of the actual level height (H 1) is determined with H 1=H 0-H 3. A height adjusting signal is brought corresponding to a height set point for the agitating device of the controller over a height adjuster at the controller, which controls height adjustment motor with a height control signal, so that the agitating device takes the height set point. The comparison between the signals of the actual filling level height and the height set point stored in the controller is carried out with a displaced control as safety control against the immersion of the agitator blade in the controller. A non-control grip is implemented, so that the filling level height is larger than the height set point. An automatic control grip is implemented independent of height adjusting signal, so that the filling level height is less than the height set point. The agitating device is downwardly immersed, until the actual adjusting height of the agitating device to a height difference x is smaller than the actual filling level height. The agitator blade is completely immersed during an agitating process. The height difference value x is pretended at the controller. The lowered control grip is implemented for the immersion protection of the agitator blade during exceeding of x-value difference. The controller is integrated with its control function in a plant controller and/or plant regulator. The motorized agitating device is highly adjustable at a vertical aggregate carrier (8) and by a cable winch. The aggregate carrier is received in the upper region in a dome-like service pit, in which the agitating device is upwardly displaceable.