The selection of different forms of original liquid evaporators and evaporation processes is indeed very important, as it directly affects the efficiency, cost, product quality, and environmental impact of the evaporation process. The following is a detailed analysis of this issue:

      1. Selection of evaporator form

      As the core equipment in the evaporation process, the choice of evaporator form directly affects the evaporation effect. Common forms of evaporators include central circulation tube evaporators, external heating evaporators, rising film evaporators, horizontal evaporators, vertical cold water tank evaporators, spiral tube evaporators, cooling pipes, serpentine pipes, external circulation evaporation equipment, suspended basket evaporators, Levin evaporators, forced circulation evaporators, and falling film evaporators. These evaporators each have their own characteristics and are suitable for different raw material properties and process requirements.

      1. Central circulation tube evaporator: compact structure, easy to manufacture, but with low circulation speed, suitable for some occasions where high circulation speed is not required.

      2. External heating evaporator: The heating chamber and separation chamber are separated for easy cleaning and replacement, and the circulation speed is high, suitable for situations that require high circulation speed.

      3. Rising film evaporator: suitable for solutions with large evaporation capacity, heat sensitivity and easy to form foam, but not suitable for solutions with high viscosity, crystal precipitation or easy to scale.

      4. Horizontal evaporator: Similar in structure to a horizontal shell and tube condenser, it is widely used in closed saltwater circulation systems, but needs to be stopped during cleaning.

      5. Forced circulation evaporator: using external power to circulate the solution at high speed in a certain direction, suitable for handling solutions with high viscosity, easy scaling, and large amounts of precipitated crystals.

      6. Falling film evaporator: Similar to rising film evaporator, but the raw material liquid is added from the top of the heating tube, suitable for various solutions, especially heat sensitive materials.

    2. Selection of evaporation process

      The selection of evaporation process should be based on various factors such as the characteristics of the original liquid, evaporation purpose, and economy.

      1. Determine the purpose of evaporation, such as increasing the concentration of the solution, concentrating the solution and recovering solvents, preparing pure solvents, recovering pure salts, harmless treatment of wastewater, zero discharge of wastewater, or resource utilization of wastewater. Different evaporation purposes will affect the selection of evaporators and the design of evaporation processes.

      2. Determine the characteristics of the evaporated solution, including its thermal sensitivity, corrosiveness, boiling point, viscosity, and density. These characteristics will directly affect the selection of evaporators, operating conditions, and material selection of equipment.

      3. Determine utility parameters such as power supply, steam pressure, cooling water inlet and allowable return water temperature. These parameters will affect the operating costs and efficiency of the evaporation process.

      4. Consider energy-saving measures such as re compression design of secondary steam, increasing efficiency to improve thermal energy utilization, recovering condensed water, and discharging sensible heat from evaporator materials. These measures can reduce energy consumption and improve the economy of evaporation processes.

      3、 Selection principle

      When choosing the evaporator form and evaporation process, the following principles should be followed:

      1. Adaptability principle: The selected evaporator should be able to adapt to the process characteristics of the evaporated material, such as viscosity, foaming, heat sensitivity, corrosiveness, etc.

      2. Economic principle: Under the premise of meeting the process requirements, the evaporator form and evaporation process with lower investment and operating costs should be selected.

      3. Reliability principle: The selected evaporator should operate reliably, be easy to operate, and be easy to maintain and repair.

      4. Environmental protection principle: The evaporation process should minimize pollution and damage to the environment, and achieve green production.

      In summary, the selection of different forms of original liquid evaporators and evaporation processes is very important, and it is necessary to comprehensively consider and weigh the pros and cons according to specific situations.