Supercritical carbon dioxide dryer

Supercritical carbon dioxidedryer

1、 Principles and Overview

Supercritical drying extraction technology is the latest discipline in modern chemical separation and is currently a rising trend internationally Develop excellent separation techniques. The so-called supercritical fluid refers to a fluid whose thermodynamic state is above the critical point (Pc, Tc), which is the point where the gas liquid interface has just disappeared. Supercritical fluid has very unique physical and chemical properties, with a density close to that of a liquid and a viscosity close to that of a gas. Its characteristics such as high diffusion coefficient, low viscosity, and high dielectric constant make it a good solvent for separation. Supercritical drying extraction refers to the process of contacting a solvent with the extracted substance in a drying vessel under high pressure and appropriate temperature, allowing the solute to diffuse into the solvent, and then changing the operating conditions in a separator to precipitate the dissolved substance for separation purposes.

Due to the selection of supercritical devicesCO₂As a supercritical drying extractant, the medium has the following characteristics:

1. Wide operating range, easy to adjust.

2. Good selectivity, targeted extraction of desired components can be achieved by controlling pressure and temperature.

3. The operating temperature is low, and dry extraction is carried out under conditions close to room temperature, which is particularly suitable for thermosensitive components,The extraction process eliminates the possibility of oxygen oxidation and light reaction, and the extract can maintain its natural flavor.

4. From dry extraction to separation, it is completed in one step. After extractionCO₂No residue on the extract.

5CO₂Non toxic, odorless, non flammable, affordable and easy to obtain, and recyclable.

6. The drying and extraction speed is fast.

In recent years, supercritical drying extraction technology has developed rapidly both domestically and internationally, with applications in hopsIndustrialization has been achieved in fields such as spices, Chinese herbal medicine, oils and fats, petrochemicals, and food and healthcare.

2、 Main technical parameters

1. Maximum drying extraction pressure: 35MPa.

2. Drying kettle capacity: 5L.

3. Temperature: normal temperature~80 ℃.

4. Maximum flow rate: 0-100L/h Adjustable.

3、 Main components

The supercritical drying (extraction) device consists of the following parts: purity of≥ 99%CO₂Gas cylinder (user provided), refrigeration device, temperature control system, pressure control system, safety protection device, portable agent tank, purifier, mixer, heat exchanger, storage tank, flow rate of100L/h andComposed of a 4L/h plunger pump, drying kettle, separation kettle, distillation column, electric control cabinet, valves, fittings, data acquisition and control system, and cabinet rack, etc.

4、 Preparation before startup

1. Firstly, check if the power supply and three-phase four wire are intact. （AC380V/50HZ）

2. Is the cooling water source of the freezer and storage tank unobstructed? The cold box contains a 30% ethylene glycol+70% aqueous solution.

3CO₂The pressure of the gas cylinder is guaranteed to be within5～6MPa The air pressure should be at least 22kg and the net weight of food grade should be no less than 22kg.

4. Check whether the pipeline joints and various connection parts are secure.

5. Add purified water and dechlorinated water to each hot box, not too full, about 2 cm away from the box cover, and check the water level before starting each time.

6. Raw materials should be loaded into the material cylinder, and should not be installed too full, away from the filter screen 2~3 About centimeters.

7. Load the material cylinder into the drying kettle, install the O-ring of the material cylinder, then put in the ventilation ring, cover the pressure ring and upper plug.

8. If extracting liquid materials or adding entrainers, place the liquid materials into the entrainer tank and pump them into the drying kettle.