Drywa is the only low temperature belt sludge dryer equipped with a CO2 heat pump developed to make sludge management efficient and cost-effective, respecting the environment and climate.

Solwa green sludge dryer

DryWa: Innovative integrated system for drying sewage sludge

DryWa technology is developed to make sludge management efficient and cost-effective, respecting the environment and climate.
Drywa is the only low temperature belt dryer equipped with a CO2 heat pump.
Compact design, no operative costs for filters and the lowest energy consumption make Drywa 100% green and eco-friendly.

Sewage sludge and sludge from ETP (particularly from Dyeing companies) are perfectly treated by DryWa without odors and air emissions, even without filters.
The process is based on a compact technology which can be used also in a series of joint modules.

DryWa is a revolutionary thermal stand-alone system to dry sewage sludge, achieving a 95% of weight reduction in only 15 m² surface (20 ft naval container). DryWa is a system to dry sewage sludge, where the input is the wet sludge (around 25% DM) and the outputs are ashes and emissions into the atmosphere.
A high performance heater inside the system generates the drying process, allowing DryWa to be a stand-alone system in terms of thermal energy. It can be placed directly inside the wastewater treatment plant without any modification. DryWa modules can be stacked into vertical systems, to increase the drying production.

Technical data

DryWa Sludge Dryer Schema

Weight reduction: 80% Max
Surface for the module installation: 15 m²
Dimensions: LxWxH 5700mm x 2260 mm x 1104 mm
Electrical power installed: 55 kWh

Maintenance costs: No filters and no emissions risks
Pay-back: Pay-back easy to calculate thanks to disposal saving costs


Flexibility in sludge treatment: Advanced ICT technology on board. Self-setting of the machine
Emissions: ZERO air emissions (odors, COV, NH3…) thanks to the closed air circuit
Environmental authorizations procedures: No specific environmental authorizations needed
Turn key system: Simple installation and ready to use with no wasted time to pre-heat
Easy to use: Fully automatic process


Industry 4.0: Real time planning, monitoring and control
Assistance and service: Predictive maintenance on-board and global service always available


REVOLUTIONARY HIGH PERFORMANCES SLUDGE DRYER: With a specific patented technology able to optimize the water extraction performances with less energy and less hot air volume needs.

SAVING YOUR SLUDGE COSTS: With the reduction of sludge weight disposal and with the reduction of transportation costs.

NO PLANT MODIFICATION: In the wastewater treatment plants no modifications are necessary, thanks to its specific shape (naval container), which is similar to the current boxes used to store sludge.

ONLY 20 FT NAVAL CONTAINER: The smallest sludge dryer. The compact shape is the result of high performances in the drying process and efficiency.

20% HIGHER EFFICIENCY: The heat recovery, combined with the perfect fluid dynamic process, allows achieving the best performances compared to competitors.

FASTER EVAPORATION BY AN INNOVATIVE TURNING ROLLER: Higher water evaporation from sludge thanks to a specific turning roller able to break and turn the dry sludge crust.

SELF CLEANING SYSTEM: To achieve always the best performances with non-stop operations and no need of external maintenance.

WEIGHT REDUCTION WITH DRY PROCESS: Strong weight reduction only with dry process. The dry sludge can be reused in various sector.

EASY ICT MANAGEMENT: A special software has been developed for all the devices (pc, tablet, smart phone, etc.) to monitor and manage DryWa remotely as locally, recording all the main data for your report.

FOCUS ON YOU: All performing data are continually sent to Isotex offices to optimize the machine to your needs and give you the best customer assistance as well as provide you with spare parts.

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