Rotary Kiln Incinerator SNCR Denitrification Equipment

      As a core equipment for industrial solid waste and hazardous waste treatment, the SNCR (Selective Non-Catalytic Reduction) denitrification technology in rotary kiln incinerators is a key process for controlling nitrogen oxide (NOx) emissions. The following provides a systematic analysis from the perspectives of technical principles, equipment composition, operational characteristics, and optimization directions:

I. Technical Principles and Process Compatibility

1. Core Reaction Mechanism
   SNCR achieves denitrification by injecting urea or ammonia solution into the high-temperature zone (850-1100°C) of the rotary kiln, where NOx undergoes a non-catalytic reduction reaction with the reducing agent to form N? and H?O. This temperature window highly aligns with the flue gas temperature at the kiln tail (typically 900-1050°C), enabling efficient denitrification without additional heating.

2. Process Integration Advantages
   The rotational motion of the rotary kiln promotes thorough mixing of flue gas and the reducing agent, extending the reaction time. Meanwhile, the SNCR system can be integrated into the kiln tail flue or decomposition furnace area without requiring large-scale modifications to the main incinerator structure, making it particularly suitable for environmental upgrades in existing projects.

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II. Equipment Composition and Key Parameters

1. Core Component Design
   • Reductant Storage and Supply System: Urea solution storage tanks (concentration 20-50%), metering pumps, and delivery pipelines must use corrosion-resistant materials (e.g., 316L stainless steel) and be equipped with electric heating devices to prevent crystallization in winter.
   • Injection System: Dual-fluid atomizing spray guns with adjustable nozzle angles (typically 15-30°) are used to cover the kiln tail cross-section. Compressed air pressure must be stabilized at 0.3-0.6 MPa to ensure atomized particle size ≤50 μm.
   • Control System: A PLC-based closed-loop control system monitors kiln tail flue gas temperature and NOx concentration in real-time, dynamically adjusts reductant flow, and controls ammonia slip to ≤8 ppm.
2. Performance Indicator Requirements
   • Denitrification Efficiency: 50-70% (affected by temperature window and mixing effectiveness).
   • Ammonia-to-Nitrogen Ratio (NSR): 1.1-1.5; excessive ammonia can lead to slip or secondary pollution.
   • Residence Time: ≥0.5s, optimized through CFD simulation of spray gun layout.
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