Sludge drying is the most expensive step in sludge management, typically accounting for 40-60% of total sludge handling costs. Low-temperature belt dryers offer a game-changing solution that reduces energy consumption by 60% while operating below odor thresholds.

How Low-Temperature Belt Dryers Work

The system uses waste heat or low-grade thermal energy (60-80 degrees C) to gently evaporate moisture from thin sludge layers on a moving belt. The low operating temperature means:

• No odor generation (below volatile compound release threshold)
• No explosion risk (well below dust ignition temperature)
• Minimal exhaust gas treatment required
• Compatible with waste heat from CHP, boiler flue gas, or solar thermal

Performance Data

Parameter	Specification
Inlet Sludge Moisture	80-85%
Outlet Sludge Moisture	10-40% (adjustable)
Evaporation Capacity	500 – 8,000 kg H2O/h
Drying Temperature	60-80 degrees C
Specific Energy Consumption	0.6-0.9 kWh/kg H2O evaporated
Belt Width	1.5 – 4.0 m
Drying Area	30 – 300 m2
Reduction in Sludge Volume	Up to 75%

Cost Comparison: Thermal Drying Technologies

Technology	Energy (kWh/kg H2O)	Operating Temp	Odor	Capital Cost
Low-Temp Belt Dryer	0.6-0.9	60-80 C	Minimal	Medium
Direct Rotary Dryer	1.2-1.8	300-600 C	Significant	High
Fluidized Bed Dryer	1.0-1.5	150-400 C	Moderate	High
Solar Drying	0.1-0.3	30-50 C	Low	Low-Medium

Waste Heat Integration

The low-temperature requirement enables use of free or low-cost heat sources:

• CHP/Generator waste heat: Jacket water (80-90 C) + exhaust gas heat recovery
• Boiler flue gas: Economizer or condensing heat exchanger
• Digester biogas: CHP waste heat (most common pairing)
• Solar thermal: Vacuum tube collectors for supplementary heat

With waste heat integration, the effective drying cost drops to $15-30 per ton of water evaporated, compared to $80-120 for direct thermal dryers.

Sludge Disposal Cost Savings

Reducing sludge moisture from 80% to 30% achieves:

• 75% reduction in sludge volume and weight
• 60-80% reduction in disposal/transport costs
• Dried sludge becomes suitable for cement kiln co-processing, land application, or RDF production
• Typical ROI: 2-3 years for medium to large plants

Feiran EP Low-Temperature Dryer

Feiran EP’s low-temperature belt dryer features SUS304/316L construction, Siemens PLC control with humidity-based automatic speed regulation, and modular design for easy capacity expansion.

Request drying system proposal: sales@yixingenviroequipment.com | WeChat: 008613771308660