Introduction：

        Heat pump evaporation refers to compressing the secondary steam evaporated from the evaporator with a compressor, increasing its pressure so that its saturation temperature exceeds the boiling point of the solution, and then sending it back to the heating chamber of the evaporator as heating steam. This method is called heat pump evaporation . The use of heat pump evaporation only needs to supply heating steam at the start-up stage of the evaporator. When the operation is stable, heating steam is no longer needed, and only the work required to boost the pressure of the secondary steam is provided, thus saving a lot of raw steam.

Selection characteristics of heat pump evaporator

  The design of the evaporator: The evaporator and the compressor are also important equipment in the heat pump evaporation system, and must be carefully considered according to the nature of the material to be concentrated

  (1)Types of heat pump evaporators: Industrial heat pump evaporators generally adopt external heating natural circulation type, central circulation tube type and rising film or falling film evaporator. There are fewer other types.

  (2)The choice of evaporator material: it should be determined according to whether the cooking solution is acidic or alkaline.

  (3)Operating pressure in the evaporator: The concentration of food and medicine generally requires that the boiling solution in the evaporator is operated under negative pressure to prevent the concentrated substance from deteriorating at high temperatures. This requires high processing quality of the evaporator to prevent the outside air from deteriorating. Internal leakage. However, in wastewater treatment and concentration production of inorganic salts, the evaporator is generally best operated at atmospheric pressure.

  (4)Consideration of equipment and operating costs: Under the same energy-saving conditions, if the focus is to reduce operating costs, then the heating area of the evaporator should be designed to be larger to make the heat transfer driving force Δt smaller. Therefore, the power consumption of the motor driving the compressor will be reduced, so that the running cost will be reduced. Stainless steel is already a common material. Should the operation be reduced, more materials must be used, but it is still cost-effective to consider the overall economic benefits.