The solid-liquid mixture crystal slurry produced by the upstream reactor or crystallization equipment is discharged into the tank of the three-in-one equipment, and the pressure difference is used as the driving force to achieve the filtration and separation of the solid-liquid mixture. Practical applications include pressure filtration, vacuum filtration, and combined filtration of pressure and vacuum. Pressure filtration uses clean compressed air, nitrogen or other inert gases. The compressed gas should be selected according to the characteristics of the solid-liquid mixture. For example, if the solid-liquid mixture is easy to be oxidized or there is an explosive medium in the solid-liquid mixture, compressed air should not be used, but inert gas should be used. According to actual experience, the general product in the pharmaceutical industry can achieve filtration with a pressure of 0.2～0.3MPa, and some products in the chemical or food industry require higher filtration pressure, and some pressure can reach 1.0MPa.
After the filtration process is completed, the next process operation is required, namely washing. The three-in-one equipment tank is equipped with a special spray device, which can make the cleaning (washing) liquid evenly distributed in the tank. By turning on the stirring system, stirring lifting mechanism, and transmission mechanism, the blades can rotate and move up and down. , So that the materials can be fully washed, and the impurities adhering to the surface of the crystal grains can be washed clean. The washing liquid used for washing and the number of washing times need to be determined according to the characteristics of materials and production processes.
The drying process of the three-in-one equipment can be hot air drying or vacuum drying. When using hot air drying or vacuum drying, clean inert gas must be used, because dust will be generated during the drying process, and the equipment operating environment must be considered as explosion-proof. At present, the mainstream drying process for three-in-one equipment is vacuum drying. The main factors affecting the vacuum drying process are the degree of vacuum, drying time, and the characteristics of the stirring blade.
The vacuum drying process uses a vacuum system to extract the inert gas from the tank to reduce the number of gas molecules and isolate the air. It is mainly suitable for materials that are easily oxidized and deteriorated, and also suitable for evaporating materials that require solvent recovery and heat-sensitive materials. In the vacuum state, it can reduce the chance of contamination of materials or inhibit the growth of certain bacteria, so it is especially suitable for drying sterile materials.