Put the medicinal herbs into the extraction tank and soak them in 5-10 times the solvent (such as water, ethanol, methanol) according to the process requirements. Open the straight through and jacket steam valves of the extraction tank, heat the extraction solution to boiling for 20-30 minutes, and then use a filter tube to draw 1/3 of the extraction solution into the concentrator. Close the straight through and jacket steam valves of the extraction tank, and open the steam valve of the heater to concentrate the liquid material. The secondary steam generated during concentration is sent to the extraction tank through the working riser of the evaporator as the heat source and solvent for extraction, in order to maintain boiling inside the extraction tank.

The secondary steam continues to rise, passes through the condenser condensate, and falls back into the extraction tank as a new solvent added to the medicine surface. The new solvent passes through the medicinal layer at high speed from top to bottom, and is drawn into the concentrator through the extraction tank filter tube. The concentrated secondary steam is then sent to the extraction tank as a heat source and new solvent. In this way, a new solvent is formed for thermal reflux extraction.