The Internal-heating vertical retort is divided, from top-bottom, into three zones, i.e. preheating zone, carbonization zone, and cooling zone. A checker wall is installed at the bottom of the carbonization zone, where gas and air are mixed and preheated before being ejected through distribution holes to burn under oxygen-deficient conditions and produce high-temperature flue gas that directly contacts the coal for heat exchange and carbonization. This combustion method allows more efficient heat to transfer to the coal, resulting in higher carbonization efficiency. The oil-gas mixture produced during carbonization rises with the flue gas, directly exchanging heat with the coal. Raw gas at approximately 80-120°C is collected by a umbrella type gas collection system and enters the gas collection tank via stand pipes and goose necks. After being cooled by ammonia water spray, the raw gas at approximately 70-80°C is sent to the gas purification system. The semi-coke moves downward into the cooling heat exchange and water quenching sections, where it is cooled to below 80°C with a moisture content of about 15%, before being discharged by a scraper conveyor. 

ACRE has optimized the Internal-heating vertical retort based on existing domestic technology, developing a retort design with independent intellectual property rights. This design achieves key process optimizations such as uniform material layer movement, uniform heating, and uniform gas distribution through innovative structural design and intelligent control systems.