I. Overview:
Supercritical extraction means that at a certain pressure and appropriate temperature, in the extraction cylinder, the solvent fully contacts with the extracted substance, and the solute diffuses into the solvent, and then the working conditions are changed in the separator to precipitate the dissolved substance, so as to achieve the purpose of separation.
Supercritical extraction has the following characteristics:
The extraction temperature is low, and the product will not be decomposed.
Selective extraction can be achieved by controlling temperature and pressure.
There is no solvent residue in the product.
The solvent can be recycled.
No environmental pollution.
Supercritical fluid extraction technology uses CO2 as solvent, which has the following advantages:
The supercritical state of CO2 is easy to realize.
No toxic pollution to food and medicine.
It has the function of preventing bacterial activity.
It is not easy to burn and has good chemical stability.
Low price and good economy.
Second, the device composition process:
The device mainly consists of a refrigeration system, a CO2 storage tank, a mixer, a filter, an extraction kettle, a separation kettle, a CO2 injection pump, a carrier pump, a pressure control system, a flowmeter, a safety protection device, an electric control cabinet, a cabinet frame, a panel and the like.
III. Technical indicators of main components:
3-1. Extraction kettle:
The charging barrel for solid and liquid materials is equipped with a water jacket circulating heating system with adjustable temperature.
Material stainless steel 316
Volume 5L
Working pressure ≤50MPa
3-2, separation kettle:
The main container for material separation, in this process, the separation effect is better by changing the pressure and temperature, and it is equipped with a water jacket circulating heating system with adjustable temperature.
Material stainless steel 316
Two sets with a volume of 2×2L
Working pressure ≤30MPa
3-3, CO2 high-pressure pump:
The CO2 liquid output is pressurized, and the pump head is made of wear-resistant special material and equipped with a cooling circulation system of the pump head, so as to prevent the friction of the pump head from heating up, prolong the service life of the pump, prevent cavitation and affect the stable supply of fluid.
The flow rate is 50L/h and the frequency conversion is adjustable.
Working pressure ≤50MPa
3-4, entrainer pump:
1/4-4L/h mechanical adjustment of flow rate
Working pressure ≤50MPa
3-5, refrigeration system:
The refrigerating capacity is 4700Kcal/h, and it is air cooled.
The temperature control range is 5℃ ~ 7℃
3-6, heat exchange system:
Change the temperature in the system through heat exchange.
Material stainless steel 316
Specification φ 6× 1 coil
Working pressure ≤50MPa
Water distribution jacket circulating heating system with adjustable temperature.
3-7, purification system:
Material stainless steel 316
Working pressure ≤50MPa
3-8, CO2 storage tank:
Material stainless steel 316
Volume 4L
Working pressure 16MPa
3-9, flowmeter:
Metal tube float flowmeter digital display remote transmission 6.3 ~ 63l/h shows instantaneous and cumulative flow respectively.
3-10, temperature control system:
The control range is adjustable from room temperature to 85℃ (water bath)
Dynamic temperature control accuracy 1℃ Double-screen digital display, programmed temperature control.
3-11, cleaning system:
The equipment is designed with a cleaning loop, which can clean the separator first and then clean the whole.
3-12, safety protection device:
Safety system is the most important part of equipment, which is divided into hard safety system and soft safety system.
Hard safety system: a safety control system that can be realized even when the equipment is in the state of no electricity, including safety valves and one-way valves. The main components such as extraction kettle and separation kettle are equipped with their own independent safety valves (the protection pressure is independently calibrated according to the pressure range of the components), and the overpressure is automatically released. After the pressure is normal, it will automatically recover to protect the safety of the components at all times.
Soft safety system: integrated circuit safety control, electric contact pressure instruments, pressure and water level alarm safety control, etc. Once triggered, the soft safety system can not work normally until the problem is solved, and it is ineffective to forcibly start the power device. After the problem is solved, it will return to normal as a necessary supplement to the hard safety system.
Power safety device: the range of system pressure can be set. If the pressure triggers the upper limit, the power output will be stopped to ensure that the system pressure will not rise again. If the pressure is lower than the lower limit, the power output will be started, which can be set as dynamic protection to adjust the safety measures of the equipment, so as to ensure the safety of the equipment.
3-13, pipeline:
The pipeline adopts valve pipe fittings with specifications of DW6/50MPa series and made of stainless steel 316. The valve stem is durable after special heat treatment, and the valve layout fully considers the maintenance and process control of all parts of the equipment.
3-14, electrical system:
Brand electrical components are used for control, and the power cord adopts the three-phase five-wire system of international common standards.
3-15, box bracket:
According to the requirements of modern laboratory, the shape design of the equipment is beautiful and generous. The operation panel is made of stainless steel laser, which is clear at a glance, well arranged and harmonious with modern laboratories.