Supercritical CO2 extraction equipment is a device that can be used for separation and refining of effective components of various natural products. The equipment mainly includes: extraction kettle, separator, CO2 storage tank, heat exchanger, distillation column, etc., among which the extraction kettle is the core equipment.
High-pressure vessel extraction kettle is used to contain the material to be extracted. It is usually made of pressure-resistant materials and can withstand the high pressure of supercritical carbon dioxide.
At present, most high-pressure vessels use hemispherical heads, spherical heads, forged tightening mouth heads and forged flat heads with a thickness not less than the thickness of the cylinder wall. However, these high-pressure vessels with head structures have the disadvantages of high cost of forgings or thick steel plates, difficult manufacturing, low material utilization rate, and long production cycle.
In view of the above situation, the new extraction kettle structure developed refers to a reinforcing hoop on the outside of the hemispherical head at the connection end of the cylinder and the hemispherical head, without turning or surfacing the transition section. It is not only suitable for heat-sleeved cylinder layer plate wrapping cylinder, but also suitable for winding cylinder.
Technical features of the new extraction kettle structure
- The outer surface of the end of the hemispherical head has a cylindrical surface and a conical surface, and is covered with a reinforcing hoop. The outer diameter of the cylindrical surface is smaller than the outer diameter of the hemispherical head; the cone angle of the conical surface is 5°~20°.
- The reinforcing hoop is made of rolled and welded steel plates and has several exhaust holes. The outer diameter is the same as that of the cylinder.
- The wall thickness of the hemispherical head is determined according to the requirements of its structure itself. When the pressure on the container is very high and the diameter is large, the hemispherical head can adopt a multi-layer structure.
- The cylinder is a single-layer cylinder or a heat sleeve cylinder, a layer plate wrapped cylinder, a flat steel belt staggered cylinder and a spiral plate cylinder.
- The bottom plane of the reinforcing hoop can be used as the support surface of the upright container, and there is no need to weld the support ring and rib plate.
- The hemispherical head has better stress resistance than the flat head, and the wall thickness of the hemispherical head is thinner, which saves materials and reduces weight;
- The technical measures of reinforcing hoops are adopted to strengthen the cylinder and hemispherical head at the connection, making the stress more reasonable.
Conclusion
The extraction kettle is one of the keys to the development of supercritical extraction technology. It has the characteristics of high strength, strong rigidity, good stability and durability, and good quick-opening sealing effect. Supercritical CO2 extraction technology has been widely used in medicine, food, chemical industry and other industries.