Liquid backflow
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I have a vacuum system at a elevation of 10.3 m that continuously feeds material into a container located at an elevation of 0.3 m. The feed pipe is submerged inside the container, but liquid keeps being sucked back up. I’m not sure what the cause is and how to fix it
Has the original poster analyzed the pressure inside the container and the density of the material? Don’t assume that 1 atmosphere is equivalent to 10 meters of water column; when the density of the water is low, this value is more than 10 meters. Also, keep in mind that the maximum vacuum is also equivalent to 10 meters of water column – it’s necessary to consider the pressure difference between the two devices.
Agree with the person above. When the density of a liquid is less than that of water, a 10-meter column of such liquid exerts less than one atmosphere of pressure.
Calculate the outlet pressure of the vacuum equipment and the pressure inside the container; it’s not necessarily a suction effect – rather, the pressure is pushed back
Transporting vacuum equipment to storage tanks at different elevations? I’m not quite sure I understand. A height difference of exactly 10m is roughly the limit for transporting water. Moreover, it is actually impossible for vacuum equipment to achieve -0.1 MPa; if the density of your material is greater than that of water, it is theoretically possible ； If the density is less than that of water, theoretically a drop of 10 meters would already cause suction. So you either need to increase the height difference (using a submersible pipe actually reduces the drop and makes backflow more likely), or you need to use a thin balancing pipe between the low-level storage tank and the vacuum device’s outlet in order to prevent backflow.
It is mainly affected by the liquid density and the pressures in the two containers. Solution: 1. Increase the bit difference between the two devices ； 2. Under the premise of meeting process requirements, increase the pressure in the high-level storage tank, reduce the pressure in the low-level storage tank, or decrease the liquid density.
This mainly depends on the medium density and the pressure difference between the two devices