As a Hydrogen Peroxide Industrial Plant, let's talk about the factors that affect evaporation.
The structure and state of the evaporator determine the efficiency of evaporation. The heating coefficient α on the side of the heated steam condensation is relatively large, while the heat transfer coefficient α on the methanol side is relatively small. In the structural design, the heat supply coefficient on the methanol side should be strengthened to achieve better heat transfer efficiency. Therefore, at the time of design, the circulation speed of the raw material methanol is high, so as to improve heat transfer and enhance evaporation.
2. Evaporation temperature
It is common knowledge that liquids are vaporized by heat and evaporation. It is affirmative to increase the temperature to facilitate the evaporation of methanol. However, when the liquid temperature is lower than the boiling temperature in the operation, the liquid vaporization can only be carried out on the surface, the evaporation rate is slow, and the production efficiency is low. In actual production, the air is bubbled in the liquid layer of methanol, and the gas in the liquid layer is continuously taken away by the air. In order to establish a new gas-liquid equilibrium, the methanol must accelerate evaporation, so that it evaporates rapidly even below the boiling point. Meet production requirements.
3. Evaporation level
Under normal circumstances, the level of evaporation liquid affects the heating area and circulation speed of this methanol. According to the evaporation heat transfer rate equation, the evaporation level is higher as the evaporation liquid level is within the optimum heating height range.
4. Equilibrium concentration of methanol concentration and methanol
When the water content of the raw material methanol is high, the evaporation amount is lowered, and in order to maintain the evaporation amount, the evaporation temperature must be increased accordingly.
In the production process, the liquid phase methanol concentration in the evaporator is collectively referred to as "equilibrium concentration", which is related to the concentration of feed methanol, air temperature, humidity, flow rate, and degree of heating of the evaporator.
5. Air flow rate
In the production of formaldehyde, air is bubbled in methanol to accelerate the evaporation of methanol. The evaporation of methanol will increase significantly with the increase of air flow. Therefore, in the design of the evaporator, the air distribution method also affects the evaporation of methanol.