The hot reflux extraction concentrator integrates extraction and concentration functions, with a compact and coherent process. Operators only need to set the parameters in the control system to automatically complete the entire process from feeding, extraction to concentration, reducing manual intervention and process connection time, lowering labor intensity, and improving production efficiency. The heat generated by heating is used to maintain the boiling and reflux of the solvent, and to assist in the evaporation of the solvent during concentration. The heat is utilized in stages without any excess heat loss. Compared with the combination of dispersed extraction and concentration equipment, it has outstanding energy-saving advantages and reduces energy consumption costs during long-term operation.

Measurement steps for hot reflux extraction concentrator:

1. Preparation before startup:

-Equipment inspection: Confirm the sealing of the slag discharge door, the status of each valve, and the absence of leaks in the pipeline, and complete equipment cleaning. Check that the steam pressure, cooling water supply, vacuum system, and power supply are operating normally.

-Feeding and soaking: Weigh the medicinal herbs according to the process requirements and put them into the extraction tank. Add a solvent (such as water or ethanol) that is 5-10 times the weight of the medicinal herbs. Close the feeding port, open the top vent valve of the tank to balance the pressure, and soak the medicinal herbs for the set time (usually 30-60 minutes).

2. Extraction and hot reflux cycle:

-Start extraction: start the cooling water system, inject steam into the extraction tank jacket or through steam valve, slowly heat it to boiling base note the amount of steam to maintain a slightly boiling state. Keep the vent valve open during boiling to prevent pressure buildup from causing explosive boiling.

-Hot reflux cycle: After boiling for 20-30 minutes, start the vacuum system to draw about 1/3 of the extraction liquid into the concentrator. Close the steam valve of the extraction tank and turn on the concentrator for heating. The secondary steam generated by concentration is liquefied by the condenser and refluxed to the extraction tank as a new solvent. Control the reflux temperature between 40-80 ℃ (water extraction should be ≤ 90 ℃, alcohol extraction should be ≤ 80 ℃) to ensure effective ingredient dissolution and reduce impurities.

-Dynamic cycle control: Maintain the extraction concentration cycle for 2-4 hours until the extract is close to colorless, indicating that the active ingredients have been basically removed.

3. Concentration and termination of reflux:

-Independent concentration stage: Close the reflux valve, open the concentrator vacuum valve (maintain vacuum degree ≥ -0.06MPa), and switch the secondary steam to the cooler. Adjust the liquid inlet of the concentrator, maintain the liquid level at the centerline of the sight glass, and continue heating and concentrating until the liquid extract reaches a specific weight of 1.1-1.34.

-Endpoint judgment: Sample and test the specific gravity of the concentrated solution. After reaching the standard, immediately close the heating valve and vacuum system, and release the concentrated paste while it is still hot to prevent wall sticking.

4. Closing operation:

-Solvent recovery: If using organic solvents such as ethanol, add water and steam to recover residual solvents.

-Cleaning and maintenance: Drain the remaining liquid medicine from the extraction tank to the storage tank, and open the slag gate to remove the residue. Activate the online cleaning system (CIP) to sterilize the equipment and clean residues.

Precautions for using the hot reflux extraction concentrator:

1. Feeding precautions: The amount of medicinal herbs to be added to each can should be determined through verification. The principle of hot reflux extraction determines that the feeding amount should be larger than that of the multifunctional extraction tank.

2. Reflux time control: Determine the start time of reflux based on the concentration of the drug solution. If the reflux time is too early and the concentration of the extraction solution is low, it will prolong the effective extraction time. If the reflux time is too late and the concentration of the extraction solution is saturated, it is not conducive to the extraction of active ingredients and also wastes energy. After 1 hour of extraction (boiling), some of the medicine should be placed in the concentration tank, refluxed, and timed. At the same time, when boiling in the extraction tank, the air inside the tank should be eliminated, otherwise pressure will be generated inside the tank.

3. Temperature control: The temperature of the reflux liquid should be controlled and not too low. At the same time, it is necessary to control the temperature inside the extraction tank and try to maintain a constant temperature. Cold extraction (below 90 ℃) has less impurities and good clarity, while hot extraction has high efficiency but poor clarity. The purpose of boiling is to enhance the diffusion and permeation of the solution, but it will cause many large molecular impurities to dissolve out.

4. Determination of extraction and concentration time: Excessive extraction will increase impurities in the extraction solution, making later separation more difficult. If the time is too short, the extraction will not be complete, wasting raw materials (the solution concentration needs to be checked during the extraction process).

5. Safety precautions: Before operation, it is necessary to wear work clothes, protective goggles, gloves, masks and other protective equipment, and pay attention to the safe distance from the equipment to avoid accidents. Especially when using organic solvents, attention should be paid to explosion-proof environments.