Despite the high load, the material wear of the NEMO® BT immersible pump remains low during the conveyance of beets in biogas production.
Beets, particularly sugar beets and specially-bred energy beets, are becoming more and more popular.
Look behind the scenes
The storage of the beets in silos or silage tubes is complicated and expensive. Collecting beet pulp in foil-lined reservoirs represents a comparatively simple and cost-effective alternative to this.
Challenge accepted
In a specific application, around 10 m³ per hour of finely diced beet was to be transported to the fermenter. However, as a semi-solid oxidation layer forms on the pulp in the lagoon, the high-viscosity substrate must be drawn off underneath this layer of scum. Horizontally installed pumps at the edge of the tank or of the pontoon can’t raise the high suction performance. On the other hand, the challenges were the low pH value of the sugar beet pulp and the high, abrasive sand content of up to 10 percent of the substrate volume.
Excellently solved
For this application, a NEMO® BT immersible pump was therefore installed. These are also used elsewhere for emptying tough to high-viscosity media such as crude oil out of tanks and pits. For this application, NETZSCH's developers therefore fitted a stator made of highly-resistant NEMOLAST® elastomer and a wear-resistant rotor. In addition, the pump is operated at an appropriate speed at about 190 rpm which increases its service life. Material wear could therefore be kept low in spite of high stresses.
