The entire plant, including all peripheral equipment, needs only 30 kW to dry sludge with an initial dry residue of 20% to a dry residue of 90%. This is a specific electrical energy demand of 0.08 kWh per kg of evaporated water – a respectable value for a plant of such a size.
Even more energy is saved with the use of heat extraction. A heat exchanger extracts the residual energy contained in the exhaust air. This energy is used to heat a building. The heating energy of 83 kW coves the energy demand of the whole building during the whole year. The small amount of outlet air (4,000 m³/h) is cleaned with a two-stage chemical washer and a downstream biofilter.
The BT 4 dryer, like all other HUBER belt dryers, is fully automated. The self-regulating drying process adjusts itself to the available heat. The dryer is controlled via clearly structured visualisation. Plant control is logical and self-explaining. Owing to the preprogrammed settings a mouse click is enough to react to varying operating conditions. It is therefore uncomplicated and easy for the local staff to operate the plant.
This is another HUBER project which demonstrates that a belt drying plant should be a complete solution which is adjusted to meet the customer's requirements to his satisfaction. The problem-free combination of innovative technology and user-friendly functionality represents an important factor of sustainable success.
Facts and figures:
- Size: BT 4
- Dryer length: 7.24 m
- Water evaporation 372 kg/h
- Maximum throughput: 478 kg/h
- Drying: from 20% DR to 90% DR
- Current demand: 30 kWh/h
- Heart source: boiler operated with sewage gas