In the operation of a multifunctional extraction and concentration unit, abnormalities in vacuum level, liquid level, or temperature are often related to air entering the system or improper valve opening. Common faults and corresponding measures are as follows:
Evaporator vacuum level too high (evaporation temperature too low)
Cause: The heating steam valve opening is too small, and the cooling water valve is opened too wide.
Solution: Properly open the steam valve wider; close the cooling water valve slightly; close the tank inlet valve slightly and increase the circulating water temperature.
Evaporator vacuum level too low (evaporation temperature too high)
Cause: The heating steam valve opening is too large, and the cooling water valve is opened too small.
Solution: Close the heating steam valve slightly and open the cooling water valve wider.
Liquid level in the concentration tank rises too high
Cause: Excessive liquid feed.
Solution: Reduce the feed flow and close the feed valve if necessary. After the liquid returns to the center line of the evaporator sight glass, reopen the feed valve.
Temperature drop in the condensation reflux extraction tank
Cause: Insufficient concentrated steam volume.
Solution: Properly open the heating steam valve wider to increase evaporation, and close the cooling water valve slightly.
Reduced condenser capacity in the extraction tank and low reflux temperature
Cause: Excessive heating evaporation.
Solution: Open the cooling water valve wider and close the heating steam valve slightly to reduce water evaporation.
Foam layer rising during concentration
Cause: Excessive liquid feed or excessively high vacuum.
Solution: Reduce the liquid feed, and properly admit air to lower the vacuum level. If conditions permit, a small amount of defoamer may be added to reduce surface tension and eliminate foam.
It should be noted that although a high vacuum level favors low-temperature evaporation, it can also promote foaming and cause liquid entrainment loss. Therefore, the vacuum level should not be controlled too high. When abnormal vacuum levels occur due to air entering the system, priority should be given to checking sealing points, valves, and vacuum pipeline connections. For non-standard parts such as steam valves, vacuum pipeline connectors, and seals in the above equipment, we can provide single-piece or small-batch machining according to customer drawings.
