MVR evaporation capacity
Thread Content
When concentrating traditional Chinese medicine extracts using an MVR evaporation unit, the evaporation rate never reaches the designed level (the equipment is 90% new, and the impact of scaling on heat transfer is not taken into account). Could some experienced professionals in this field give some advice on what are the common factors that affect the evaporation rate of MVR?
1. What is the compressor operation frequency? 2. Is the heat exchange area of the heat exchanger insufficient? 3. The evaporation area of the evaporator is insufficient!
With a set of MVR units of the same specifications, the evaporation rate can meet the design requirements; therefore factors such as compressor frequency, heat exchanger area, and evaporator area can be disregarded. However, the operating current of the compressor is slightly low, and the outlet temperature is a bit high
Different compositions of the solution result in different evaporation rates, as the boiling point changes. Generally, dilute solutions have lower boiling points and thus higher evaporation rates; once evaporation proceeds to a certain extent, an increase in the concentration leads to an elevation of the boiling point, after which the evaporation rate decreases.
Is it related to the piping? The pipe resistance is different
An increase in boiling point does affect heat transfer efficiency, but the amount of vaporization during initial evaporation remains unchanged, so it shouldn’t be due to the rise in boiling point.
Firstly, the selection of pipes is based on steam pipeline standards and specific processes, which generally poses no issues. Secondly, another identical set of devices can also achieve the designed evaporation rate, so it should not be a piping issue. I think the problem lies with the compressor, but I don’t know much about compressors, so I’d like to hear the advice from those who are more experienced
What type of compressor is it, centrifugal or positive-displacement?
Haha, the problem has been solved. It’s not a compressor issue; it’s a fault with the flow meter. It was a misunderstanding. Thank you all for your guidance