CRA x Adani Infra: Sequential Biogas Mixing Improves Digester Stability
CRA delivered a complete sequential digester biogas mixing system for Adani Infra at the Naini-I STP facility, engineered to improve mixing uniformity, digestion stability, and process reliability across three existing RCC digesters. Designed for continuous recirculation and automated distribution, the system ensured uniform gas injection while eliminating the need for mechanical mixing equipment inside the tank.
Deliver uniform gas distribution across multiple large digesters
Adani required a dependable mixing solution for three operating digesters without introducing mechanical complexity or reliability risks inside the tanks. The project involved several constraints:
- Uneven mixing impacting digestion stability
- Requirement for uniform injection across large tank volumes
- Continuous-duty operation under biogas conditions
- Integration with existing plant infrastructure
- Reliable automation with minimal operator intervention
A fully integrated sequential injection system engineered for uniform mixing
A fully integrated sequential injection system engineered for uniform mixing
CRA engineered and supplied a complete gas mixing package covering compression, distribution, automation, and integration across all digesters. The system recirculates biogas and distributes it sequentially across multiple injection points for uniform mixing performance.
Core system components
- Compressors: 3 working + 1 common standby with VFD
- Rotary sequential valve: 1 per digester
- Gas lances and ports: 15 per digester
- Filter cum moisture trap and flame arrestors
- SS316 piping, valves, and full system integration
Engineering and execution
- Designed for automated sequential gas injection
- Continuous-duty operation with IE3 flameproof motors
- Centralized control panel with full instrumentation
- Complete piping scope from suction to lances
Stable operation and improved digestion performance across all units
- Uniform gas distribution across all digesters
- Improved biological activity and process stability
- Reliable unattended operation with low downtime
- Validated performance through 72-hour PG testing
- Guaranteed power consumption of 18 kW per system
Proving CRA’s Expertise in Delivering Integrated Sequential Biogas Mixing Systems
This project highlights CRA’s ability to deliver engineered biogas mixing systems tailored for large wastewater infrastructure. The sequential injection approach provides a scalable and repeatable solution for facilities seeking reliable mixing performance without mechanical complexity inside the digester.
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