Analysis of the reasons for the low production capacity of wastewater evaporators

  If the design of the wastewater evaporator is not reasonable, it will lead to the wastewater evaporator not reaching its production capacity, mainly in the following four aspects:

1. Distribution of effective temperature differences for each effect

It is common for wastewater evaporators to use positive pressure heating, with heating temperatures mostly between 105~120 ℃, and some even higher. According to the heat transfer rate, the larger the heat transfer temperature difference, the smaller the heat transfer area of the evaporator. The distribution of heat transfer temperature difference can be based on the principles of equal pressure drop and non equal pressure drop.

When designing a wastewater evaporator, the impact of steam pressure fluctuations on the evaporation effect should be considered. Therefore, in order to obtain stable steam pressure, the steam before entering the evaporator needs to be depressurized to meet the stable evaporation of the evaporator.

2. The impact of temperature difference loss

The impact of boiling point increase on the evaporator cannot be ignored, as there are many examples of insufficient constant production capacity of the evaporator due to the lack of consideration of boiling point increase. Generally, the temperature difference loss of each effect is mainly reflected in the following three aspects:

(1) The increase in boiling point due to the temperature difference caused by the decrease in vapor pressure of a solution refers to the fact that at the same temperature, the vapor pressure of a solution is always lower than that of a pure solvent due to the presence of solutes. Therefore, when the pressure at the liquid surface is constant, the boiling point of the solution is higher than that of a pure solvent, and the temperature higher than that is called the increase in boiling point of the solution.

(2) The static pressure strength of the solution inside the heating tube is lost due to its temperature difference.

(3) The temperature difference loss caused by the resistance of the fluid in the pipeline due to the secondary steam between each effect.

The above three issues of boiling point increase should be considered in the design and calculation, otherwise the calculated evaporation heat transfer area may be too small due to the lack of consideration of boiling point increase, resulting in the inability to meet the design production capacity.

3. The impact of condenser

The composition of wastewater is complex, often accompanied by low boiling point volatile organic solvents entering the condenser, which affects the Chinese effect of the condenser. The heat transfer coefficient of the condenser should be determined according to the actual situation, and the determined heat transfer area of the condenser is safe.

4. The influence of other factors

The evaporator used for Wastewater treatment has heat loss during the evaporation process. To reduce the heat loss of the evaporator, the efficiency body, separator, and steam pipeline of the evaporator should be insulated and insulated.