Accumulator Function

Urea synthesis converts ammonia and CO₂ to urea with intermediate ammonium carbamate formation. Unconverted carbamate from decomposition sections recycles to reactor requiring intermediate storage. Accumulators buffer concentration and flow variations, provide surge volume during upsets, and ensure stable high-pressure reactor feed maintaining efficient urea production.

Vessel Design

Vertical or horizontal pressure vessel with inlet from carbamate recovery, vapor space for ammonia off-gas, liquid outlet to reactor feed pump, level instrumentation, heating jacket or coils preventing crystallization, and relief protection. ERGIL sizes vessels based on recycle flow rate and required surge time typically 10-30 minutes.

Operating Conditions

Design pressure 15-30 bar accommodates carbamate solution vapor pressure at operating temperature 60-90°C. Materials resist corrosion from ammonia and CO₂. Heating maintains temperature preventing ammonium carbamate crystallization blocking lines and vessels. Proper venting removes non-condensables.

Material Selection

Stainless steel 316L construction resists corrosion from ammonium carbamate, ammonia, and urea solutions. Duplex or super duplex grades for severe corrosive conditions. Heating jacket in carbon steel with proper corrosion protection. Design per ASME Section VIII with materials meeting urea plant corrosion requirements.

Applications

Urea production plants with carbamate recycle systems, fertilizer facilities, and chemical plants synthesizing urea-based products. Serves facilities with production capacities 500-3,500 tons per day urea requiring reliable carbamate solution handling and recycle management.

Temperature Control

Heating jacket or internal coils maintain 70-90°C preventing carbamate crystallization. Temperature control modulates steam or hot water flow. Insulation minimizes heat losses. Proper heating ensures pumpable solution and prevents equipment fouling.

Level Control

Level transmitters control reactor feed pump maintaining stable solution supply. High and low-level alarms manage inventory. Integration with upstream decomposition and downstream synthesis optimizes carbamate recycle rates. Automated operation coordinates with reactor control systems.

Performance Benefits

Provides essential surge capacity for stable urea synthesis operation. Temperature control prevents crystallization maintaining solution flow. Buffers process variations protecting reactor from feed disturbances. Corrosion-resistant materials ensure long service life in aggressive carbamate environment.

Construction Standards

Design per ASME Section VIII with materials suitable for ammonium carbamate service. Relief valve sizing accounts for runaway reaction scenarios. Heating system design prevents hotspots causing decomposition. Complete documentation with corrosion analysis and material certifications.

Operational Advantages

Reliable carbamate solution storage with proper heating and materials. Simple level-based control integrates with urea synthesis. Minimal maintenance with corrosion-resistant construction. Critical component ensuring continuous urea production.

ERGIL carbamate solution accumulators deliver dependable intermediate storage ensuring stable urea synthesis operations in fertilizer production facilities.