Vacuum system ultimate pressure problem
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The current ultimate vacuum required by the system is -100Kpa. The current unit is an oil-free vertical vacuum pump plus a first- and second-level Roots pump. The unit has been running for more than two years. The vacuum degree of the current unit is very unstable, which has seriously affected the quality of the system products. In response to the above issues, please ask the following questions:: 1. Is the vacuum degree of the system related to the ambient temperature? Is there a problem that the vacuum degree decreases as the ambient temperature increases? 2. The current actual operating vacuum degree is only between -96.5~-98.5Kpa. System leaks can be eliminated. How to analyze the unit itself? 3. How to upgrade the current unit, add a three-stage Roots pump, or replace the vertical pump with a water ring vacuum pump? I need a god to clear up the confusion.
This post was last edited by 39766 on 2020-3-13 23:14 1: Your system is a dry system. The system itself is not greatly affected by temperature, but it needs to be analyzed based on your process, such as the condensation effect in front of the pump~~ 2: See if the time from starting the pump to opening Roots has become longer. I suspect it is caused by the decrease in vacuum and air volume after the vertical oil-free pump wears out! 3: Adding three-stage Roots can improve it, but the vacuum system is too complex and other problems may occur. My suggestion is to remove the vertical pump and the first stage Roots and replace it with a screw vacuum pump that is one model larger than the vertical pump. The investment will be much greater, but the time to find the time will be much shorter.
Now the main reason is that the ultimate vacuum of the unit cannot be reached. In the early winter, the vacuum degree could reach -100Kpa, so we must consider several aspects. First, the analysis of the current unit, and second, the cost and advantages and disadvantages of the transformation.
There is a condenser in front of the pump, which is cooled by circulating water.
Replace the screw compressor with better vacuum.
It doesn't have much influence on the outside temperature. Are there any leaks in your pumped-down unit?
Agree with the second floor's point of view, it is recommended to replace the reciprocating vacuum pump with a screw vacuum pump. The reciprocating vacuum pump wears out greatly after being used for 2 years and its efficiency decreases. The use of the two-screw vacuum pump as a backing pump can eliminate the need for a Roots vacuum pump and reduce failure points. Although the initial investment is relatively large, the corresponding failure rate is low and energy saving is better.
When the ambient temperature of the unit itself is high, the vacuum degree is only about -98. Leakage points in the unit itself can be eliminated
Is there any relevant information available? study * For a moment~
It is related to the cooling water of the front condenser. In winter, the water temperature is low and the condensation effect is good. In the condenser, the gaseous state changes to a liquid state, and the volume becomes smaller, which is also like a vacuum device. In terms of renovation, the second floor is not appropriate. The poor performance of the reciprocating pump affects the evacuation time and the heating of the backing pump. In order to improve the vacuum degree in summer, it is necessary to add a main pump to increase the air pumping capacity and turn the original main pump into a backing pump. A Roots pump costs tens of thousands of dollars, so you can consider replacing it. Replacing the reciprocating pump with a water ring pump and a screw pump cannot solve the problem of vacuum degree.
With two identical units, can they be modified based on the ideas in the picture? Will the vacuum degree of the system be improved if the original two units are connected in parallel instead of in series?