Issues related to reaction vessels

The definition of a reaction vessel should be as follows: It is a cylindrical reactor with a low height-to-diameter ratio, used to carry out single-phase liquid-phase reactions as well as multi-phase reactions such as liquid-liquid, gas-liquid, liquid-solid, and gas-liquid-solid reactions. The vessel is usually equipped with stirring devices (mechanical stirring, air flow stirring, etc.). When the height-to-diameter ratio is large, multiple-layer impellers can be used. When the material needs to be heated or cooled during the reaction process, a jacket can be installed on the reactor wall, heat exchange surfaces can be placed inside the reactor, or heat exchange can be achieved through external circulation. 　　Operation mode: Batch reactors can be classified by operation mode as follows: ① Batch reactor, also known as an intermittent batch reactor. 　　It offers flexible operation and is easy to adapt to different operating conditions and product types, making it suitable for the production of products in small batches, with a variety of types, and those that require a longer reaction time. The disadvantages of batch reactors are: they require auxiliary operations such as loading and unloading, and it is also difficult to maintain consistent product quality. However, for some reaction processes, such as certain fermentation and polymerization reactions, it remains difficult to achieve continuous production, and batch reactors are still used to this day. 　　②Continuous batch reactor, or continuous kettle. It can avoid the disadvantages of batch reactors, but the stirring action causes backmixing of the fluid inside the reactor. In situations where mixing is intense, the liquid viscosity is low, or the average residence time is long, the flow pattern of the material inside the reactor can be considered as fully mixed, and such a reactor is accordingly referred to as a fully mixed reactor. In situations where a high conversion rate is required or where there are side reactions in series, mixing back in batch reactors is a disadvantageous factor. At this time, a multi-reactor series configuration can be used to reduce the adverse effects of backmixing, and the reaction conditions can be controlled separately for each reactor. 　　③Semi-continuous batch reactor. 　　It refers to a reactor in which one type of reactant is added at once while another type is added continuously, and its characteristics lie between those of a batch reactor and a continuous reactor. Reactor vessels are not used in the main process of ammonia synthesis; the ammonia synthesis tower is a fixed-bed gas-phase reactor.