Method for producing emulsion

A device for preparation of an emulsion comprising:

• a heating device into which water flows continuously or intermittently to obtain heated and pressurized water or a water-insoluble substance to be emulsified flows continuously or intermittently to obtain a heated and pressurized water-insoluble substance;
• a first flow merger in which under pressure, the heated and pressurized water obtained by the heating device continuously or intermittently merges with a water-insoluble substance to be emulsified or the heated and pressurized water-insoluble substance to be emulsified obtained by the heating device continuously or intermittently merges with water;
• a mixing apparatus into which the liquid merged by the first flow merger flows and the water-insoluble substance is dissolved in the water while maintaining at a temperature and pressure approximately at the vapor-liquid critical point of water;
• a second flow merger in which the water-insoluble substance dissolved in water flowing out from the mixing apparatus merges with a surfactant at a temperature and pressure approximately at the vapor-liquid critical point of water;
• and
• a cooling device into which the liquids merged by the second flow merger flows and a mixture of the dissolved material and surfactant is cooled to obtain an emulsion in which the water-insoluble substance is emulsified in water or an emulsion in which water is emulsified in the water-insoluble substance;
• and
• the heating device, the first flow merger, the mixing apparatus, the second flow merger and the cooling device connect each other in this order.