Reaction vessel and heat exchange element

According to the corrosion situation, various metal materials are selected for production, and high-pressure vessels are made of composite materials, which can reduce investment. To meet the needs of heat transfer, the container is usually equipped with a jacket outside and a coil inside, with no more than 3 sets of coils. When equipped with a guide tube, the number of coils can be increased. When the volume of the container is greater than 10m ³, hollow heat exchange plates can be used as internal heat transfer elements, which can increase the heat transfer area per unit volume by more than twice.

Multiple coil structures:

Common built-in heat exchange components have the characteristics of simple processing, low investment, and high pressure resistance. The area of the coil in the reactor generally does not exceed 5 ㎡/m ³, and its heat transfer capacity can meet more than 90% of the reaction, but it cannot meet the requirements of large volume and intense exothermic chemical reactions, especially in situations where the heat transfer temperature difference is small.

Multi group coil structure diagram

Heat exchange plate structure (ZL)A reaction vessel and heat exchange plate, ZL201420849938.6）：

When multiple sets of coils still cannot meet the heat transfer requirements, the conventional design will adopt the form of external circulation+external heat exchanger, and the heat transfer capacity can be infinitely amplified. However, this increases the investment and energy consumption of the device, and the service life of the external circulation pump is relatively short under high pressure and catalyst wear. Therefore, the built-in heat exchange plate is an effective way to improve heat transfer capacity.

The built-in heat exchange plate is generally installed inside containers larger than 10m ³, with dozens of vertical heat exchange plates evenly distributed in the container in a circular arrangement. The heat exchange plates have a certain curvature and appropriate sweep angle during installation, providing good guidance for fluid flow. Each heat exchange plate is made of two metal plates welded together, leaving honeycomb shaped holes between the two plates. The cooling medium flows inside to carry away the reaction heat, and the honeycomb structure greatly increases the strength of the heat exchange plate. This heat transfer form can significantly increase the heat transfer area to over 10 ㎡/m ³, and the heat transfer coefficient is significantly higher than that of coils. Due to the significant increase in heat transfer capacity, the requirement for heat transfer temperature difference is reduced. Soft water with higher temperature can be used for circulating cooling inside the heat exchange plate, and ordinary industrial circulating water can be used to cool the soft water. This method can fundamentally solve the problem of internal structure of heat exchange elements in the reactor. In summary, the built-in heat exchange plate technology makes the heat transfer design of liquid-phase catalytic hydrogenation units more flexible.

Compared with coils, the obvious advantages of heat exchange plates are large heat transfer area, high heat transfer coefficient, and reduced flow attenuation of liquid in the axial direction, which is more conducive to catalyst suspension.

Built in heat exchange plate

Comparison diagram of flow field between reactor built-in coil and heat exchange plate