The height of the TGIC anaerobic reactor can reach 16m ~28m, and the height-to-diameter ratio is generally 4-8. It consists of 5 basic parts: mixing zone, granular sludge expanded bed zone, fine treatment zone, internal circulation system and water outlet zone. The internal circulation system is the core part of the IC process. It consists of a lower three-phase separator, a biogas riser, a gas-liquid separator and a mud-water downcomer. The significant difference from UASB and EGSB reactors is that "the unique characteristics of IC anaerobic reactors" The "internal circulation structure" uses the expansion of biogas to achieve internal circulation of a large amount of mixed liquid without the need for external energy. The mass transfer process is strengthened and the removal efficiency of organic matter is greatly improved.