Abstract: The loop reactors are applied widely for its simple structure and many merits. To introduce the loop reactor for coal liquefaction，a large-scale loop reactor cold model experimental apparatus was built. Many tests for nitrogen-water system were made with this apparatus，and the effects of gas superficial velocity，pressure and superficial tension on gas holdup were investigated. The gas holdups of bubble state and loop state were compared and loop reactor’s operational flexibility was investigated. Important conclusions were reached.

摘要： 环流反应器结构简单，优点多，因而近年来应用广泛。为了将环流反应器引入煤炭液化领域，建立了大型环流反应器冷模试验装置。进行了氮气-水体系的冷模运转试验，考察了表观气速、压力和表面张力对环流反应器中气含率的影响。在此基础上，对鼓泡状态和环流状态下的气含率进行了比较，并考察了环流反应器的操作弹性，得出了有重要意义的结论。