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  • Does vacuum suck water and denser fluids?

    Are you having a query regarding boiling point of liquids, their displacement in vacuum> Searching for details regarding understanding their behaviour? On this page our experts shall respond to your query.

    Fluids displace themselves through pressure difference. When you apply vacuum to an equipment, the boiling point reduces and the low boiling components in your liquid will vaporize. The uncondensed gases too get sucked into vacuum.
    But what about the liquid you feed?
    Is there a chance that liquid will get sucked into vacuum?
  • Answers

    3 Answers found.
  • A very technical question. All depends on the design of the reactor, process conditions and operating parameters.

    What is the aim? You want to displace material from one place to another place or you want to separate an ingredient? Based on these issues we have to design the system.

    When you want to displace liquid from one place to another place you have to design the vacuum levels and temperature of working in such a way that no liquid will get evaporate during the process. if it happens your working will never be effective.

    The boiling temperature of a liquid will come down when you apply vacuum. The boiling temperature of the same liquid will vary based on vacuum levels and temperature. Even we can suck high viscosity material using a vacuum and transfer from one place to another place.

    ISRO will use vacuum casting technique for making rockets in which is a very high viscous composite propellant It is a mixture of solids and liquids and the functioning of the material depends very much on the composition. So the casting will be designed by vacuum in which all the parameters including flow rate of the material is also designed in such a way that the temperature will not go beyond a particular level, the material will flow from the vessel to the casing of the rocket within the specified time. This should happen so accurately that even there should not be any air entrapment also.
    All depends on your material properties, the constituents, the level of vacuum, the temperature of the system, the positioning of the reactors, the design of the reactor etc.

    So if you want to know the exact conditions you have to use, you have to give me more details. However, I think generally, how it is work is explained above.

    always confident

  • If the pressure inside a sealed container is gradually reduced then as per the PVT phase relations the boiling point of the liquid present inside the container reduces and at a certain reduced pressure the evaporation of the liquid will start and the liquid will change into the gas form. This usually happens when pressure is reduced. At the same time if instead of reducing the pressure we reduce the temperature then at a certain temperature the liquid may turn into solid. The temperature below which a substance (liquid or gas) forms a stable solid is incidentally called the solidus. So changing the pressure and temperature conditions change the phase conditions of the substance and are governed by the PVT phase relationships of that particular material. These phase diagrams are available in the text books for easy understanding.

    One thing in this matter which is to be understood is that a substance can exist in a mixture of phases also and it is entirely related to pressure and temperature conditions. There are some solids which when heated up, turn directly in gas form without changing to the intermediate liquid form. All sort of combinations are possible in the large PVT regime of the substances.

    So, if the pressure is slowly decreased in a sealed system then liquid will change to gaseous state and gas will fill the space and all the liquid might get converted to the gas. In some cases there may be some thermodynamic equilibrium and some liquid might co-exist with gas. There is no way that the liquid will disappear in that condition by the sucking action of the vacuum. It is simply the phase transformation of the substance from one state to other. Here, it is a sealed system and there is no vacuum sucking and it is in fact the reduction in pressure that is changing the phase. Vacuum sucking takes place when there is one container from which the air is taken out through suction and slowly vacuum is formed. In such cases the liquid will also be sucked out by the suction machine. There is no phase transformation here.

    Knowledge is power.

  • There are different types of Vacuum for home, hotel industry and factory usage. It is all depend on the device one uses in a certain place. Most of the Vacuum process almost same but has different capacity and mode to choose for the uses and depends.

    Hand dryer vacuum for example, it really helps to dry the wet hand within short time (few seconds) with different pressure mode set and reduce the tissue paper usage that tissue paper usually and finally throws around the corner in the bin that fills huge and then recycle them later which creates lot of process and uses manpower. Tissue paper rack and bin reduces when Hand dryer Vacuum uses and such vacuum really helps as hygienic atmosphere within too.

    Yes, once vacuum use for suck and dry purpose then the Vacuum (HEPA) 'filter' of the Vacuum convert the liquid to vaporize and store it within the device filter. And it's chemical change vaporize to clean within the filter with the heat and composition process in the device itself. One can change the filter after sometime or when its limit is over.

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