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在化工、食品和制药工业中经常遇到热敏性物料的浓缩问题。液膜式蒸发器属于一次通过式蒸发器,其停留时间足够短,可减压操作,适用于热敏性物料的浓缩。液膜式蒸发器分升膜、降膜和升降膜式,升膜和升降膜蒸发器的升膜部分的输送动力通常用料液泵。郭雪岩等为蒸发浓缩小处理量的热敏性物料而开发了一种新型蒸发器,其升膜的输送动力用蒸气喷射,尽管前人对绝热两相流和垂直管内的流动沸腾进行了大量的研究,对这种特殊的流动沸腾的研究仍是必要的。文献[2]对蒸气加热的恒壁温条件下的蒸气喷射升液的升膜蒸发进行了实验研究和理论分析。本文的喷射升膜蒸发实验研究是在透明的石英管内,在恒热通量下进行,在石英玻璃管外壁镀一层极薄的透明导电膜,这既可以电加热又不影响观察管内的流动现象。本研究包括对蒸气喷射升膜流动状态的观测和恒热通量条件下喷射蒸发传热的实验研究。
In the chemical, food and pharmaceutical industries often encounter the problem of concentration of heat-sensitive materials. Liquid film evaporator belongs to a through-type evaporator, its residence time is short enough, decompression operation, suitable for the concentration of heat-sensitive materials. Liquid film evaporator sub-rising film, falling film and lifting film, rising film and rising film evaporator lift film part of the delivery of power usually liquid material pump. Guo Xueyan et al. Developed a new type of evaporator for evaporating and concentrating a small amount of heat-sensitive material, and the transport force of its rising film was sprayed by steam. Although a great deal of research has been done on the flow boiling in adiabatic two-phase flow and vertical tube, Research on this particular flow boiling is still necessary. Literature [2] carried out experimental research and theoretical analysis on the rising film evaporation of steam jet rising liquid under the conditions of constant temperature and steam temperature. In this paper, the experimental study of jet rising film evaporation is carried out in a transparent quartz tube under constant heat flux. An extremely thin transparent conductive film is coated on the outer wall of the quartz glass tube, which can not only electrically heat but also influence the flow in the observation tube phenomenon. This study includes the experimental study on the flow state of steam jet rising film and the heat transfer of jet evaporation under constant heat flux.