The advantages of the technical structure of supercritical fluid extraction
Supercritical extraction device consists of extraction kettle, separation kettle, preheater, rectification column, high pressure metering pump, filter, purifier, refrigeration system, pressure control, temperature control, flow display, computer automatic collection, processing data and printing System
Flow chart of supercritical extraction device
1. Extraction kettle: The maximum working pressure can be up to 50MPa, the maximum operating temperature is 85°C, and the inner solid-basket is used (1 uses 1 spare). The basket can be detached from top to bottom to facilitate the discharge of solid materials; meanwhile Equipped with a liquid basket with built-in stainless steel filler for the extraction of liquid materials.
2. Separation kettle: The maximum working pressure is 30MPa. The inlet is connected to the bottom of the cannula. The kettle body is equipped with a heating jacket and insulation layer. The maximum separation temperature can reach 85°C. The inner wall is processed by a special process, and the surface roughness is formed into a mirror surface, which can effectively improve the retention of the inner wall material.
3. Preheater: The maximum design pressure is 55MPa, the maximum working pressure is up to 50MPa, and the maximum operating temperature is 85°C. The preheater is placed in a constant-temperature water bath, plus an insulation layer and a stainless steel decorative layer.
The preheater is integrated with the constant temperature water bath, reducing the hot water transmission waterway, and synchronizing the temperature of each kettle body with its corresponding preheater.
4, rectification column: the highest design pressure of 30MPa (also can be designed according to user requirements higher pressure), four temperature control, column tray and stainless steel packing, stainless steel packing using three different specifications of the volume of packing, on which A lot of small holes are covered with different fillers, which can change the mass transfer rate, so that different media can be used. The temperature is four-stage temperature control, water bath heating, pipeline pump circulation, one sampling port for each section, and the thermal circulation pump is resistant to corrosion. Temperature-resistant piping pump.
5. High-pressure metering pump: CO2 pump: The flow rate is selected as appropriate. The maximum discharge pressure is 50 MPa. The frequency control flow rate and the flow adjustment range are 15%-100%. The pump head is cooled by the cooling liquid in the cold box.
Sub-pump: The flow rate is selected as appropriate, the rated discharge pressure is 50MPa, the double-piston FM control flow, and the flow adjustment range is 15%-100%.
6. Filter: The maximum design pressure is 16MPa, and the interior is filled with molecular sieve or silica gel, which can filter impurities and moisture. The number is 2 and it is used in parallel to facilitate the replacement of desiccant.
Gas-liquid separator: The maximum design pressure is 16MPa. It is placed in front of the filter and forms an anti-ice blocking double insurance with the filter.
7. Purifier: The design pressure is 50 MPa, and the filter and silica gel are installed inside.
8. Refrigeration system: The core piece refrigerator adopts the imported French Melosure closed compressor.
9, temperature control: extraction kettle, separation kettle are equipped with temperature and temperature control double-layer system, that is, one meter measures the kettle body temperature, the other only controls the heat source (constant temperature water bath) temperature, effectively control the thermal inertia phenomenon, distillation column Due to the characteristics of small internal diameter, thin wall thickness, small heating layer volume, and short heat transmission distance, a single instrument is used for temperature control and temperature measurement.
10. Pressure display: The accuracy should be 0.4 and 1.5. The extraction kettle, separation kettle, and rectification column all use a 0.4-level pressure gauge, because the accuracy of the reading will be related to the determination of the best parameters of the extraction and separation process.
The supercritical unit is equipped with computer automatic collection and processing of data and its printing system. The automatic collection part of the data is to automatically collect the weight before extraction, the weight after extraction, the pressure and temperature of the extraction kettle, the pressure and temperature of the separation of the kettle, the pressure and temperature of the distillation column, the flow of the loop and the flow of the loop, in which the extraction is before the extraction. The acquisition of weight and weight data after extraction is acquired through electronic scales (with computer interface) or electronic balance; the acquisition of pressure data is collected through the pressure sensors configured on the kettle. The collection of temperature data is transmitted through the temperature probe induction signal to the thermostat, and the temperature control instrument with the RS232 interface can be directly connected with the computer. The collection of temperature data is collected. The collection of flow data is collected by the flow sensor to collect signals to two instruments. The instrument is connected with the computer with the RS232 interface, and the flow data is collected automatically.