Why is the vacuum level dropping?
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I’ve run into a troubling issue recently: the vacuum level in the last stage of the three-effect evaporation system drops by about 20% every morning between 5-7 o’clock and in the afternoon between 5-7 o’clock. At these times, the water level in the cooling tank is at its highest, which means that this should be the period when the most water is used for cooling. It’s hard to understand what could cause this problem when all other process conditions remain unchanged. Please help analyze it as well.
It is recommended that you check the entire process flow – for example, are points 5 to 7 the intervals for feeding/material discharge? Voltage drop caused by peak electricity demand?
Three-effect evaporation, on what type of device is it used?
Production is continuous, meaning continuous feeding and continuous discharging.
It is used in the brine evaporation system.
Program control issues, checking time parameters and variables related to points 5-7
There must still be some detail that hasn’t been noticed. It is recommended to record the parameters that affect the vacuum level of the evaporator for further analysis, such as steam pressure and temperature (for steam injection processes) ； Temperature and flow rate of circulating water (current of the circulation pump) ； Current of the vacuum pump. Check again what operations were performed on the 5-7 o’clock positions Is this the case in every shift (excluding human error, such as incorrect switching of valves)?
Yes, this work is in progress; the reasons behind it must be identified, otherwise it will affect production. There is another suspicion: could it be a problem with non-condensable gases?
With periodic problems, does the amount of non-condensable gas increase during the same period? I personally suspect that there is a high likelihood that the conditions related to public assistance encountered problems during this period. Others can’t help with this kind of work; one must calm down and pay close attention to the process and the details. “Identifying the causes of a problem is often more important than solving it”
I’m not familiar with your three-effect evaporation system, but if your vacuum system is powered by a jet pump, I have a few suggestions that should basically solve the problem. 1. Carefully check the individual vacuum gauges in the vacuum system to determine how the temperature, vacuum level, and other parameters differ from their normal values under normal operating conditions; this will likely help identify the problem area. 2. If the first method doesn’t work, it is possible to appropriately close a valve at a certain point, as long as the manufacturing process is not affected, and then observe the changes in vacuum level; this way, the issues can be identified one by one. 3. If there is a spare jet pump, try switching to it; this can help rule out problems with the jet pump itself. Other effects of cooling water, such as cracks in expansion joints, inadequate drainage in the system, leaks in pump seals, or poor sealing of water seals, can all lead to such outcomes; these issues can be resolved by addressing them one by one. 4. Everything has a cause; you are the one who knows best the conditions on site. Once you understand the principles of vacuum, and combine that knowledge with your own system’s operational procedures, it is not difficult to determine the reasons for vacuum failure. 5. Additionally, I would like to remind the original poster that although the vacuum system is not very noticeable, it usually comes equipped with interlocks. When making adjustments, one must think carefully before taking action; production work involves many responsibilities, so avoid carelessness that could lead to serious consequences.
Is it true that when the usage is at its highest, your cooling water supply is taken away by other users?