The sewage sludge mechanically dewatered to approx. 20 – 30 % DS content is extruded on a special extruder. The pellets fall directly onto a perforated conveyoer belt and form a pile that can be ventilated well. The product is fed into the drier tunnel, where hot air flows through it drying it carefully.

The conveyor belt takes the product slowly through the drier tunnel. Mechanical strain like e.g. frictional, shearing or centrifugal stressing are minimized by this forced belt conveying. This is especially important to overcome the thixotrope phase in drying.

The system can work without remixing and dries up to the requested final moisture in one passage. This provides a smooth continuous operation without longsome start-ups and shut-downs.

The retention time in the drying zone can be adjusted to the minute by the frequency-controlled drives. Thus the drier can be adapted extremely well and very flexibly to the most different requirements (through-put, DS contents, drying temperatures).

The homogeneous product structure guarantees a very constant drying and produces a high-quality, dust-free granulate, which is excellently suitable for all further ways of disposal.




The STELA BELT DRIER SYSTEM distinguishes itself by the following advantages: • high-quality final product, granulated, dust-free, hygienized, storeable
• energy saving through exhaust air recirculation
• uncomplicated operation and maintenance through clear design
• flexible installation, as one or multiple belt drier, according to the requirements
• best accessibility and optimum inspection possibilities through large doors and windows
• pre-granulation for optimal ventilation for effective and low-cost drying
• integrated cooling zone for product cooling with heat recovery
• full and partial drying in one step (without remixing of dry product)
• drying degree adjustable from 65 to 95 % DS
• low-temperature drying for safe operation, long operating life, low vapours load and fast start-up and shut-down
• flexible heating (fuel oil, natural gas, sewer gas, steam, water, thermal oil, waste heat recovery)
• utilization of external residual energy (air, flue gas, water, steam) economically possible
• careful product conveying by the belt, long operating life
• exactly defined, adjustable retention time – optimum adjustment to your requirements.