Low temperature liquid evaporator has atmospheric type and steam water bath type, etc. The atmospheric evaporator is composed of evaporating tubes with fin, which is placed in several groups side by side and has a relatively large volume. As the low temperature liquid flows through, the surface of the evaporating fin will Frost gradually. The Frost should cover the surface of the evaporator. When its thickness increases, the evaporation efficiency decreases and the evaporation quantity decreases sharply with time. As shown in Figure 150, defrosting methods are generally needed, such as blowing away the frost with steam or sweeping away the frost with broom, which can recover the evaporation quantity.
Steam water bath evaporator uses hot water to heat the low temperature liquid in the evaporating tube to make it evaporate. Before the low temperature liquid flows in, pure water (no chlorine) should be poured into the evaporator to the overflow port, then steam should be slowly poured in, and the temperature control should be set at about 60℃ (not too high ). First open the gas outlet valve, then slowly feed into the low temperature liquid, use the flow control valve to adjust to the required flow, and control the outlet gas temperature above-15℃ to prevent the outlet pipeline from frosting.
In winter, when the evaporator stops using, pay attention to discharge the remaining water in the evaporator, or blow in a small amount of steam, or keep the overflow state, the water temperature should be controlled at 20 ~ 40℃, prevent water bath from freezing. Steam pipe drain should be kept in good working condition. The coil of liquid evaporator should generally be managed according to the pressure vessel. Therefore, the pressure vessel should be inspected regularly according to the national regulations, and can be put into operation only after passing the inspection.
