Evaporation is the basic unit operation of zui, which is common in the operation of chemical unit. From the operation mode, it can be divided into single-effect evaporation, multi-effect evaporation and direct contact evaporation. According to the fluid circulation method, it can be divided into non-circulating evaporation and natural circulation evaporation. Forced circulation type evaporation, wiped film evaporation and centrifugal thin film evaporation. Different evaporators are used for different materials during design. The correct application can not only improve the quality of products, but also save energy, reduce production costs and improve economic efficiency.
1. Principle The new centrifugal thin film evaporator adopts a built-in conical rotary heater. The material is directly fed into the conical heater by the conveying pipe. Under the push of centrifugal force, it is rolled and heated along the heating surface, and the entire evaporation process is completed at the top of the cone. The volatilized light component is recovered into the
Condenser through the secondary vapor outlet, and the heavy component is transported into the finished storage tank by the discharge collecting pipe, and the material that does not reach the concentration requirement is recycled to the evaporator through the circulation pump for secondary evaporation.
Second, the characteristics 1, high evaporation strength of the material on the high-speed rotating heating surface to generate centrifugal force, the centrifugal force generated can reach hundreds or even thousands of times the gravity, under such a large centrifugal force, the material formed on the heating surface The film thickness can reach 0.1mm, so the evaporation effect is good, the evaporation intensity is large, and the total heat transfer coefficient can reach 4000-8000kal/m2.hrc.
2, short residence time: due to the high-speed rotation of the cone heating surface to generate such a large centrifugal force, the material quickly flows from the small end of the cone to the outside, the entire heating and evaporation process takes only 1-2 seconds.
3, low evaporation temperature: the new centrifugal thin film evaporator is operated under vacuum, and the space inside the evaporator is large enough, so the vacuum is higher than the average evaporator, so the boiling point of the material can be greatly reduced, at a lower The evaporation operation is carried out at a temperature.
4, the operation flexibility: centrifugal thin film evaporator can control the residence time of the material on the heating surface at different speeds, so that the material reaches the required concentration. Secondly, the position height of the discharge collecting pipe can be adjusted, and the concentration can be stabilized.
5, has a unique foaming inhibition effect: the ordinary evaporator for the foaming materials in the heating process is more difficult to handle, generally using defoaming or foam accumulation, a unique foaming inhibition function.
6, clean and efficient: the centrifugal thin film evaporator has a simple structure, less dead angle, no need to scrape, different from the scraper type film evaporator, avoiding the friction between the scraper and the heating surface, eliminating the pollution caused by the scraper wear, easy Sterilization is especially suitable for products that are not required by GMP in the pharmaceutical industry.
7, clear and efficient: Centrifugal suitable film hair device with mirror observation hole, the material concentration process and film formation situation at a glance, there are other evaporators /
8. High efficiency and energy saving: Due to the good film formation of the centrifugal thin film evaporator, the evaporation intensity is large and the heat energy utilization rate is high. Compared with the traditional evaporator, the evaporation efficiency is significantly improved, and the heat energy utilization rate is high, which is an efficient energy saving. Evaporator.
However, the centrifugal thin film evaporator is also limited. If the viscosity of the material exceeds 200CP at the evaporation temperature, it is not suitable to use a centrifugal thin film evaporator. Since the peripheral configuration is more, the price is higher than that of the general evaporator.
Third, the scope of application:
Due to the above obvious characteristics of the centrifugal thin film evaporator, as long as the viscosity of the material does not exceed 200CP, the evaporation process can be completed by a centrifugal thin film evaporator, especially for products with extremely high heat sensitivity, and high foaming when heated by evaporation. Evaporation of materials such as antibiotic fermentation broth, blood products and aqueous protein solutions, especially for products with extremely high heat sensitivity, and materials with high foaming properties when heated by evaporation, such as antibiotic fermentation broth, blood products and aqueous protein solutions. Evaporation, especially for materials with high foaming during evaporation, other forms of evaporator are not easy to solve, and centrifugal thin film evaporators are a good form.
August 16, 2022
