Can a water ring vacuum pump draw in water vapor?
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This post was last edited by Against the current and wind on 2023-12-8 at 10:27. A water ring vacuum pump is used to create a negative pressure; the gas being drawn in is a mixture of water vapor and a small amount of air. It is planned to first condense the water vapor using a condenser, thereby reducing the volume of gas and thus decreasing the suction capacity of the water ring vacuum pump. The condensed gas will contain a small amount of liquid water. Question 1: Is it necessary to install a gas-liquid separator between the condenser and the water ring vacuum pump? ； If the condenser is installed at a higher level than the water ring pump, the condensate can flow automatically into the water ring pump; in this case, is it possible to do without a gas-liquid separator? ； Question 2: For the water ring pump, the working medium is water; what is its inlet condition – is it at positive pressure or slightly negative pressure? Question 3: For the working medium used in water ring vacuum pumps – water – does its pressure need to be close to atmospheric pressure after gas-liquid separation? For the circulation of the working medium water, some require external power, while in others it isn’t mentioned (it may be present or not); where can this information be found or what are the relevant terms used? It’s really amateurish; it’s my first time dealing with water ring pumps. If possible, please advise on which direction to consider the issue. Thank you all.
A receiving device should be installed in front of the pump, and this device must be located below the water ring vacuum pump. The water ring vacuum pump can only be used for evacuating air; it is not capable of pumping water. A detailed plan can be provided
Question 1: Is it necessary to install a gas-liquid separator between the condenser and the water ring vacuum pump? Yes, it is generally necessary to install a gas-liquid separator. When using a water ring vacuum pump to draw in gases containing water vapor, even though most of the water vapor is condensed by the condenser, the gas may still contain uncondensed water vapor as well as a small amount of liquid water. Although water ring vacuum pumps can handle a certain amount of liquid water, carrying an excessive amount of it can reduce the pump’s efficiency and may cause damage to its internal components. - If the condenser is highly efficient and is installed at a higher level than the water ring pump, allowing the condensate to flow naturally into the water ring pump, it is theoretically possible to reduce the need for a gas-liquid separator. However, this design requires very precise engineering controls and maintenance to prevent any accidental flow of liquid water directly into the pump and cause damage. - If the condensed gas still contains liquid water, in order to protect the water ring vacuum pump from the effects of liquid water, it is recommended to install a gas-liquid separator to ensure that what enters the pump is mainly gaseous. Question 2: For the water ring pump, whose working medium is water, is it in a positive pressure state or a slightly negative pressure state when it enters? The working medium of a water ring vacuum pump usually enters the pump body at a pressure close to atmospheric pressure or slightly positive. This is because the working principle of a water ring vacuum pump involves a rotor that is mounted eccentrically and rotates within the pump chamber, causing the working fluid (usually water) to form a water ring with uneven thickness due to centrifugal force. When the working medium, water, is thrown toward the periphery of the pump casing, a series of sealed cavities are formed between the rotor blades and the water ring. As the rotor rotates, these cavities gradually expand and become connected to the inlet, thereby creating a negative pressure that draws in gas. During the exhaust process, these cavities gradually shrink as the rotor rotates, compressing the gas within them until it connects with the exhaust port, thus completing the compression and exhaust process. - Regarding the supply of liquid, pumps generally require a stable water supply system to ensure that the working medium is supplied at a constant pressure. - If the water supply is insufficient or there are faults in the water supply system, it is likely that the water, which serves as the working medium for the pump, enters the pump under slight negative pressure; this can affect the pump’s suction efficiency and service life. .
1. Add a liquid separator – the majority of the fluid is water; it should not be fed directly into the pump. 2. The water inside the pump is thrown around due to rotation, and the water vapor drawn in is under negative pressure. 3. Since the liquid separated by the separator is under negative pressure, it must be pumped away under pressure or the installation location must be high enough to take advantage of static pressure
Thank you to the two friends above for their advice. I wanted to give points to both of them, but it seems my rank is too low – I can only give points once a day. It’s embarrassing. Giving extra points doesn’t mean anything else; it’s just a way to show respect for the two of them.
1. It is necessary to add a vapor-liquid separation tank. First, the water temperature entering the liquid ring pump should preferably be kept below 30 degrees; an increase in temperature creates a negative pressure inside the pump chamber, which causes the water within the pump to boil and leads to cavitation. 2. The liquid ring pump operates under negative pressure conditions. 3. Nowadays, two-stage liquid ring booster pumps are available, which solve the problems associated with using liquid ring compressors; a single liquid ring pump is sufficient to handle the pressure discharge requirements.