The single effect external circulation vacuum concentrator is designed based on thermodynamic evaporation principles and fluid dynamics, achieving low-temperature and high-efficiency concentration by reducing boiling point in a vacuum environment. The core workflow can be divided into three stages: firstly, the feed liquid is transported to the tubular heater through an external circulation pump, and heated to 70-85 ℃ under a steam pressure of 0.15-0.25MPa; Subsequently, the high-temperature liquid enters the evaporation chamber in a tangential direction and vaporizes instantly in a negative pressure environment maintained by the vacuum system at -0.075 to -0.085 MPa, with a boiling point that can drop to 45-60 ℃; The final secondary steam is purified by the built-in cyclone separator and wire mesh demister before entering the condensation system, while the concentrated liquid is returned to the heating chamber through the downcomer to form a closed cycle. This external circulation design enables the evaporation intensity to reach 80-120kg/(m ² · h), which is more than 30% higher than the traditional internal circulation structure.
The single effect external circulation vacuum concentrator equipment adopts modular design, mainly including five functional units:
Heating system: Adopting a multi pass tube heat exchanger, the tube bundles are arranged in a triangular shape, and the heat transfer area is adjustable from 10-50m ². The material used is 316L stainless steel or titanium alloy to meet the requirements of corrosive materials
Evaporation separation system: The evaporation chamber is designed as a cylindrical cone structure with a diameter to height ratio of 1:1.5-2.0. Inside, a guide plate is installed to form a forced vortex, which can reduce the entrainment of mist to<1%
Vacuum system: composed of a water ring vacuum pump, condenser, and gas-liquid separator, with a maximum vacuum degree of -0.095MPa, equipped with an automatic air supply valve to maintain pressure stability
• Circulating system: High temperature resistant centrifugal pump (flow rate 5-30m ³/h) is used, and the impeller is optimized by hydraulic model with NPSHr value<3m to avoid cavitation
• Control system: Integrated PLC and touch screen, real-time monitoring of 12 parameters including evaporation temperature, vacuum degree, circulation flow rate, etc., with automatic discharge and concentration chain control functions