Supercritical CO2 fluid extraction technology is a new separation technology in modern chemical separation. It has the characteristics of fast mass transfer rate, strong penetration ability, high extraction efficiency and low operating temperature. This technology has been widely used in medicine, food, chemical industry and other industries.
Design requirements for supercritical extraction devices
With the development of industrialized SFE devices, instruments and equipment are the key to ensuring the reliability, safety, rationality of operation and sufficient convenience of SFE devices.
The SFE extraction device equipment includes the following components: refrigeration system, extraction system, entrainer circulation system, separation system, CO₂ circulation system and control system. The extraction process is a pressure-bearing process. There are high-pressure containers, which are extraction kettles; there are also some medium-pressure containers, such as separators and storage tanks, whose main body and key parts are extraction kettles.
The overall requirements for the design of extraction kettles are focused on safety and economy. Safety is the premise and economy is the goal. Under the premise of ensuring safety, the economic requirements should be met as much as possible. Different extraction kettles should be selected for materials of different forms.
The so-called safety contains two meanings: structural integrity and sealing. Structural integrity mainly refers to the fact that the extraction kettle, on the basis of meeting the important parameters of functional requirements, must also meet the relevant regulations and indicators such as strength, stiffness, stability and durability.
The supercritical fluid extraction process is carried out under high pressure and is mostly intermittent operation. The materials in the extraction kettle need to be frequently replaced and often opened for cleaning. Therefore, the characteristics of the supercritical fluid extraction process determine that the extraction kettle needs to adopt a quick-opening sealing structure. The extraction kettle is subjected to high pressure, and the quality of the steel used determines the limit of its maximum working pressure.
The extraction kettle in the supercritical CO₂ extraction process is composed of a cylinder, a material basket, a quick-opening cover and a clamp. The inner bevel of the clamp tightly buckles the upper bevel flange of the quick-opening cover with the lower bevel convex of the upper part of the cylinder, which can quickly cover the extraction kettle.
Conclusion
The supercritical extraction kettle has the characteristics of high strength, strong rigidity, good stability and durability, and good quick-opening sealing effect. Supercritical CO₂ extraction technology has broad application prospects in the food, chemical and pharmaceutical industries.