(19)
(11) EP 4 279 737 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
22.11.2023 Bulletin 2023/47

(21) Application number: 23174199.2

(22) Date of filing: 19.05.2023
(51) International Patent Classification (IPC): 
F04B 35/00(2006.01)
F04D 17/18(2006.01)
 F04B 39/00(2006.01)
(52) Cooperative Patent Classification (CPC):
F04B 35/008; F04B 39/0011; F04D 17/18; F04B 37/14; F04B 41/02; F04B 53/141; F04F 5/06; F04F 5/08
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA
Designated Validation States:
KH MA MD TN

(30) Priority: 20.05.2022 CN 202210553496

(71) Applicant: Zhejiang University
Hangzhou, Zhejiang 310058 (CN)

(72) Inventors:
  • LI, Xin
    Hangzhou (CN)
  • XIAN, Dongting
    Hangzhou (CN)

(74) Representative: Sun, Yiming 
HUASUN Patent- und Rechtsanwälte Friedrichstraße 33
80801 München
80801 München (DE)

   


(54) AIR EXTRACTOR COMPRISING A LIQUID PUMP


(57) The present invention discloses an air extractor, including a liquid cavity, an air extracting cavity, a connection channel, a drainage channel, and an air extracting channel, where the liquid cavity contains rotating liquid, the air extracting cavity has liquid therein, the liquid in the air extracting cavity is in communication with the liquid cavity through the connection channel, the liquid cavity drains the liquid through the drainage channel, the air extracting cavity is in communication with an object to be subjected to air extraction through the air extracting channel, and air in the object to be subjected to air extraction flows through the air extracting channel into the air extracting cavity. According to the air extractor provided in the present invention, the air is extracted by negative pressure generated by flowing of the rotating liquid, and the negative pressure can be increased by using a rotating fluid that is relatively denser. The air extractor provided in the present invention has small vibration and noise, and is easy to manufacture and has a small volume.


Description

TECHNICAL FIELD



[0001] The present invention pertains to the technical field of negative pressure generation, and relates to an air extractor.

BACKGROUND



[0002] A centrifugal air extracting pump can produce a negative pressure and use the negative pressure to extract air. An operating principle of the centrifugal air extracting pump is shown in FIG. 1. The centrifugal air extracting pump has a rotating air cavity (18) in which air rotates at high speed. Usually, technicians drive the air in the cavity to rotate by rotating blades (4) that are installed in the cavity. The rotating air cavity is provided with an air extracting channel (5) and an exhaust channel (17). The air extracting channel is closer to the center of rotation of the rotating air than the exhaust channel. The rotating air in the cavity may generate a centrifugal inertia force. Under the driving of the centrifugal inertia force, air close to the center of the rotational flow moves to the periphery, thereby forming a radial pressure distribution with low central pressure and high peripheral pressure. If the exhaust channel is connected to an external environment, the peripheral pressure in the cavity may be considered basically the same as the pressure of the external environment. Therefore, the pressure in the cavity is negative pressure, and the closer to the center of the rotating air, the stronger the negative pressure. The air extracting channel is connected to the rotating air cavity and an object to be subjected to air extraction. The negative pressure in the cavity extracts the air out of the object to be subjected to air extraction through the air extracting channel. Obviously, the greater the negative pressure in the cavity, the greater the air suction capacity. The level of the negative pressure in the cavity is determined by the centrifugal inertia force of the rotational air flow in the cavity. Usually, methods for increasing the centrifugal inertia force are to increase the radial size of the rotational air flow (for example, increase the radius of the cavity and the radius of blades) and increase the speed of the rotational air flow (for example, increase the rotational speed of the blades). However, these methods have the following disadvantages:
  1. (1) Increasing the radial size of the rotational air flow also leads to larger volume and poor portability of the centrifugal air extracting pump. In addition, it is difficult to produce large-size blades. When the blades are rotating, resistance increases, and the blades are easy to break. A moment arm of the resistance is large, and thus a moment of the resistance is large, which leads to inefficient operation of the motor.
  2. (2) Although increasing the rotating speed of the blades may increase the centrifugal inertia force, the rated speed of the motor cannot be increased indefinitely, usually only 3000 rpm to 5000 rpm. Therefore, the rated speed of the motor limits the increase of the centrifugal inertia force.

SUMMARY



[0003] An objective of the present invention is to provide an air extractor to overcome the disadvantages of the prior art. The air extractor extracts air by using negative pressure generated by the rotational liquid flow. The air extractor generates high air extraction pressure and small vibration and noise, and is easy to manufacture and has a small volume.

[0004] The present invention uses the following solutions to achieve the foregoing objective: An air extractor, including a liquid cavity, an air extracting cavity, a connection channel, a drainage channel, and an air extracting channel, where the liquid cavity contains rotating liquid, the air extracting cavity has liquid therein, the liquid in the air extracting cavity is in communication with the liquid cavity through the connection channel, the liquid cavity drains the liquid through the drainage channel, a communication position of the connection channel and the liquid cavity is closer to the center of the rotating liquid in the liquid cavity than a communication position of the drainage channel and the liquid cavity, the air extracting cavity is in communication with an object to be subjected to air extraction through the air extracting channel, and air in the object to be subjected to air extraction flows through the air extracting channel into the air extracting cavity.

[0005] In the foregoing technical solution, further, the air extracting cavity includes two or more air extracting sub-cavities. Accordingly, corresponding to the air extracting sub-cavities, the drainage channel includes two or more drainage sub-channels, the air extracting channel includes two or more air extracting sub-channels, and the connection channel includes two or more connection sub-channels. The air extracting sub-cavity is in communication with the liquid cavity through the drainage sub-channel. The air extracting sub-cavity is further in communication with the liquid cavity through the connection sub-channel. The air extracting sub-cavity is in communication with the object to be subjected to air extraction through the air extracting sub-channel. In addition, an environment channel is further disposed on the air extracting sub-cavities, the environment channel includes two or more environment sub-channels, and the air extracting sub-cavity is in communication with an external environment through the environment sub-channel. The air extractor further includes switching mechanisms for controlling opening and closing of the channels.

[0006] Further, a first switching mechanism is disposed on the connection sub-channel, a second switching mechanism is disposed on the drainage sub-channel, a third switching mechanism is disposed on the air extracting sub-channel, and a fourth switching mechanism is disposed on the environment sub-channel.

[0007] For the foregoing device, continuous air extraction of the device is achieved through the following switching actions:
  1. (1) Denoting one or more of the air extracting sub-cavities as an air extracting sub-cavity A, opening the corresponding first switching mechanism and third switching mechanism, and meanwhile, closing the corresponding second switching mechanism and fourth switching mechanism, performing operation on one or more of the remaining air extracting sub-cavities and denoting the same as an air extracting sub-cavity B, opening the corresponding second switching mechanism and fourth switching mechanism, and meanwhile, closing the corresponding first switching mechanism and third switching mechanism;
  2. (2) Starting the device, to form a rotational liquid flow in the liquid cavity, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;
  3. (3) Before the liquid level of the liquid in the air extracting sub-cavity A is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity A, closing the first switching mechanism and the third switching mechanism corresponding to the air extracting sub-cavity A and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A and the first switching mechanism and the third switching mechanism corresponding to the air extracting sub-cavity B, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity B through the air extracting sub-channel corresponding to the air extracting sub-cavity B, and causing the liquid to enter the air extracting sub-cavity A through the drainage sub-channel corresponding to the air extracting sub-cavity A;


[0008] Repeating (1) to (3) to control opening and closing of the switching mechanisms on the air extracting sub-cavity A and the air extracting sub-cavity B, thereby achieving continuous extraction of the air in the object to be subjected to air extraction.

[0009] Alternatively, continuous air extraction of the device is achieved through the following switching actions:
  1. (1) Denoting one or more of the air extracting sub-cavities as an air extracting sub-cavity A, opening the corresponding first switching mechanism and third switching mechanism, and meanwhile, closing the corresponding second switching mechanism and fourth switching mechanism, performing operation on one or more of the remaining air extracting sub-cavities and denoting the same as an air extracting sub-cavity B, opening the corresponding second switching mechanism and fourth switching mechanism, and meanwhile, closing the first switching mechanism and the third switching mechanism;
  2. (2) Starting the device, to form a rotational liquid flow in the liquid cavity, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;
  3. (3) Before the liquid level of the liquid in the air extracting sub-cavity A is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity A, closing the first switching mechanism corresponding to the air extracting sub-cavity A and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B; and opening the third switching mechanism corresponding to the air extracting sub-cavity B to enable the air extracting sub-cavity A to be in communication with the air extracting sub-cavity B, then closing the third switching mechanism corresponding to the air extracting sub-cavity A, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A and the first switching mechanism corresponding to the air extracting sub-cavity B, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity B through the air extracting sub-channel corresponding to the air extracting sub-cavity B, and causing the liquid to enter the air extracting sub-cavity A through the drainage sub-channel corresponding to the air extracting sub-cavity A;
  4. (4) Before the liquid level of the liquid in the air extracting sub-cavity B is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity B, closing the first switching mechanism corresponding to the air extracting sub-cavity B and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A; and opening the third switching mechanism corresponding to the air extracting sub-cavity A to enable the air extracting sub-cavity A to be in communication with the air extracting sub-cavity B, then closing the third switching mechanism corresponding to the air extracting sub-cavity B, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B and the first switching mechanism corresponding to the air extracting sub-cavity A, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;


[0010] Repeating (3) and (4) to achieve continuous extraction of the air in the object to be subjected to air extraction.

[0011] Further, an air bubble channel and an air bubble collection cavity are disposed on the liquid cavity, where the air bubble collection cavity is in communication with the liquid in the liquid cavity through the air bubble channel, and air bubbles in the liquid cavity enter the air bubble collection cavity through the air bubble channel under the effect of buoyancy.

[0012] Further, the device includes an air release channel and an air release mechanism, where the air release mechanism is in communication with the air bubble collection cavity through the air release channel, to exhaust the air in the air collection cavity.

[0013] Further, an air-liquid blocker is disposed in the air extracting cavity, and the air-liquid blocker is configured to reduce contact between the air and the liquid, and the air-liquid blocker can move up or down with the liquid level of the liquid.

[0014] Further, a plurality of liquid cavities are disposed and connected in series, that is, the drainage channel of the preceding liquid cavity is in communication with only the connection channel of the following liquid cavity.

[0015] Further, a plurality of liquid cavities are disposed and connected in parallel, that is, the connection channels of all the liquid cavities communicate, and are in communication with the air extracting cavity, and the drainage channels of all the liquid cavities communicate for draining the liquid.

[0016] Compared with the prior art, the air extractor of the present invention has the following technical advantages:
The air extractor of the present invention uses the negative pressure generated by the flowing of the rotating liquid to extract the air. In this manner, the negative pressure can be easily increased by selecting a rotating fluid that is relatively denser, and the air extraction efficiency is high. Moreover, the negative pressure generated by the device of the present invention can effectively avoid the problems of other air pumps such as negative pressure fluctuations caused by vibration, and can generate stable negative pressure. In addition, according to the air extractor, requirements on the motor and other equipment and requirements on machining accuracy can be greatly reduced, and the costs can be greatly reduced.

BRIEF DESCRIPTION OF DRAWINGS



[0017] 

FIG. 1 is a schematic diagram of an operating principle of a centrifugal air extracting pump in the prior art, where (a) is a structural cutaway view, and (b) is a top view of blades;

FIG. 2 is a specific schematic structural diagram of an air extractor according to the present invention, where (a) is a structural cutaway view, and (b) is a top view of blades;

FIG. 3 is a schematic diagram of an air extracting process of the device of FIG. 2, where (a) shows an initial state, and (b) shows a stable state;

FIG. 4 is another specific schematic structural diagram of an air extractor according to the present invention;

FIG. 5 is a schematic structural diagram of an air bubble collection cavity in an air extractor according to the present invention;

FIG. 6 is a schematic diagram of an air release channel and an air release mechanism disposed on the air bubble collection cavity in an air extractor according to the present invention;

FIG. 7 is a schematic structural diagram of an air-liquid blocker in an air extractor according to the present invention;

FIG. 8 is another schematic structural diagram of an air-liquid blocker in an air extractor according to the present invention;

FIG. 9 is a schematic structural diagram of liquid cavities connected in series in an air extractor according to the present invention; and

FIG. 10 is a schematic structural diagram of liquid cavities connected in parallel in an air extractor according to the present invention.



[0018] In the drawings: 1. liquid cavity; 2. air extracting cavity; 3. motor; 4. blade; 5. air extracting channel; 6. drainage channel; 7. connection channel; 8. object to be subjected to air extraction; 9. environment channel; 10. first switching mechanism; 11. second switching mechanism; 12. third switching mechanism; 13. fourth switching mechanism; 14. air bubble collection cavity; 15. air bubble channel; 16. air-liquid blocker; 17. exhaust channel; 18. rotating air cavity; 19. liquid level; 20. air bubble; 21. air release channel; and 22. air release mechanism.

[0019] FIG. 4 shows an air extracting cavity A and an air extracting cavity B, and accordingly, each of the foregoing components is denoted as a referential number composed of a component number and a corresponding letter. For example, the air extracting channel on the air extracting cavity A is denoted as air extracting sub-channel 5A.

[0020] FIG. 8 and FIG. 9 show a liquid cavity a and a liquid cavity b, and accordingly, each of the foregoing components is denoted as a referential number composed of a component number and a corresponding letter. For example, the drainage channel provided in the liquid cavity a is denoted as drainage channel 6a.

DESCRIPTION OF EMBODIMENTS



[0021] To make the technical problems, technical solutions and beneficial effects to be resolved by the present invention more clear, the present invention is further described in detail below in combination with accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not used to limit the present invention.

Embodiment 1



[0022] FIG. 2 is a schematic structural diagram of an air extractor according to the present invention. The device includes a liquid cavity 1, an air extracting cavity 2, blades 4, and a motor 3, where the liquid cavity contains liquid, the blades 4 are installed in the liquid cavity 1, and the motor 3 drives the blades 4 to rotate. The blades that are rotating drive the liquid in the liquid cavity to rotate. There is liquid in the air extracting cavity 2. The liquid in the liquid cavity is in communication with the liquid in the air extracting cavity through a connection channel 7. A drainage channel 6 is further disposed on the liquid cavity, and the liquid cavity is in communication with an external environment through the drainage channel 6. In the liquid cavity 1, the position of the connection channel 7 is closer to the center of the rotating liquid than the position of the drainage channel 6. An air extracting channel 5 is disposed on the air extracting cavity 2, and the air extracting cavity is in communication with an object to be subjected to air extraction 8 (for example, an air tank, as shown in FIG. 3(a)) through the air extracting channel 5. Air in the object to be subjected to air extraction is extracted and flows into the air extracting cavity 2 through the air extracting channel 5. In this embodiment, the drainage channel 6 is disposed on the outermost side of the liquid cavity, the connection channel 7 is disposed at the center of the liquid cavity. The positions of the drainage channel 6 and the connection channel 7 may also be set according to specific situations, provided that a communication position of the connection channel 7 and the liquid cavity is closer to the center of the rotating liquid than a communication position of the drainage channel 6 and the liquid cavity.

[0023] The rotating liquid in the liquid cavity 1 generates a centrifugal inertia force. Since the density of the liquid is much higher than that of the air, the centrifugal inertia force of the rotating liquid is much greater than that of rotating air in FIG. 1. Then, the pressure distribution with low central pressure and high peripheral pressure is formed in the liquid cavity. The liquid discharge channel 6 is in communication with the external environment, so that the pressure at the edge of the rotating liquid is equal to the pressure of the external environment. In the liquid cavity, the position of the connection channel 7 is closer to the center of the rotating liquid than the position of the drainage channel 6, so that the pressure at the connection channel 7 is less than the pressure at the drainage channel 6 (equivalent to the pressure of the external environment). That is, the pressure at the connection channel 7 is negative pressure. The liquid in the air extracting cavity 2 is extracted by the negative pressure through the connection channel 7, and is drained through the drainage channel 6. The liquid level in the air extracting cavity 2 decreases, so that the air pressure in the air extracting cavity decreases to form the negative pressure. The air in the object to be subjected to air extraction 8 is extracted by the negative pressure through the air extracting channel 5.

[0024] An example in which the object to be subjected to air extraction is an air tank is used for description. As shown in FIG. 3, the air tank is in communication with the air extracting cavity 2 through the air extracting channel 5. In an initial state (FIG. 3(a)), the air extracting cavity is filled with liquid, and the liquid level 19 is located at the top of the air extracting cavity. Then, the blades 4 start to rotate, forming a rotational liquid flow in the liquid cavity 1. Negative pressure (denoted as negative pressure A) is formed in the liquid cavity due to the centrifugal inertia force of the rotating liquid. The liquid in the air extracting cavity is extracted by the negative pressure A through the connection channel 7, so that the liquid level decreases, thereby forming negative pressure (negative pressure B) in the air extracting cavity. Air in the air tank is extracted by the negative pressure B of the air extracting cavity through the air extracting channel, so that the pressure in the air tank is reduced to form negative pressure (denoted as negative pressure C). In the air extracting cavity, if pressure generated by the height of the liquid is ignored, the pressures in the air extracting cavities are the same, that is, the negative pressure B. During an extraction process, the negative pressure A is higher than the negative pressure B, and the negative pressure B is higher than the negative pressure C. Finally, when the extraction process ends, the negative pressure A, negative pressure B, and negative pressure C will be balanced, that is, the negative pressure A is equal to the negative pressure B and the negative pressure C. In this case, the liquid level is kept stable at a height (FIG. 3(b)).

[0025] A comparison between the air extractor of the present invention and the centrifugal evacuating pump as shown in FIG. 1 shows that the size and the rotational speed of blades of the two are the same. It is known that a centrifugal inertia force of a rotating fluid is proportional to the density of the fluid, so that the negative pressure formed by the centrifugal inertia force is also proportional to the density of the fluid. Obviously, final negative pressure formed by a centrifugal air extracting pump of FIG. 1 in an air tank may be much lower than that of the present invention. This is because the rotating fluid in the centrifugal pump is air, while the rotating fluid of the present invention is the liquid with the density that is hundreds or even thousands of times that of the former (for example, the former is the air and the latter is water, and a density difference is 830 times). If the centrifugal air extracting pump needs to reach the negative pressure of the present invention, the rotating speed of the blades thereof must be increased by about 30 times. Obviously, this is very difficult. The rotating speed of the motor is limited by electrical and mechanical properties of the motor (for example, a motor rotor coil, a rotating bearing, or rotating friction) and cannot be increased indefinitely. The present invention increases the negative pressure by using a high-density rotating fluid. In addition, according to the present invention, the liquid is disposed in the air extracting cavity, and the liquid cavity must be in communication with the liquid in the air extracting cavity through the connection channel. This ensures that there is a rotational liquid flow in the liquid cavity during the extraction process. If the liquid is not disposed in the air extracting cavity, or the connection channel is in direct communication with the air in the air extracting cavity, the air may be extracted into the liquid cavity. Because the density of the air is less than that of the liquid, air may gather at the center of the rotational flow, forming a central air mass, and then squeeze out some or all of the liquid in the liquid cavity. With less rotary flowing of the liquid, the centrifugal inertia force becomes smaller, thereby weakening the negative pressure in the liquid cavity, and then weakening the negative pressure in the air extracting cavity.

[0026] Moreover, in addition to the centrifugal air extracting pump, there may be a piston-type air extracting pump and a screw-type air extracting pump. The piston- type air extracting pump forms extremely high negative pressure through the reciprocating motion of a piston. However, because the piston-type air extracting pump uses the motor and a crank slider mechanism, which is an asymmetric mechanical structure, to drive the reciprocating motion of the piston, the asymmetric mechanical structure has the disadvantage of extremely severe vibration, and the negative pressure may fluctuate due to the vibration. A screw-type air extracting pump extracts air and forms negative pressure through engagement of two screws. Screw engagement requires extremely high machining precision, which leads to high costs and heavy weight of the screw type air extracting pump. Blade motion of the present invention is axially symmetric and has no vibration problem, so the negative pressure is stable; and the blades driving the liquid to rotate do not require extremely high machining precision, so the costs of the centrifugal air extracting pump are extremely low.

[0027] In Embodiment 1, if the air is continuously extracted from the object to be subjected to air extraction 8, the liquid level 19 of the air extracting cavity 2 is decreased until there is no liquid in the air extracting cavity. If air extraction is further performed, the air enters the liquid cavity 1 and extrudes the liquid out of the liquid cavity. As a result, there is no rotary flowing of the liquid in the liquid cavity, so that the negative pressure is severely weakened.

Embodiment 2



[0028] To resolve this problem, an air extracting cavity of the present invention may include two or more air extracting sub-cavities. Accordingly, corresponding to the air extracting sub-cavities, a drainage channel includes two or more drainage sub-channels, an air extracting channel includes two or more air extracting sub-channels, and a connection channel includes two or more connection sub-channels. The air extracting sub-cavity is in communication with the liquid cavity through the drainage sub-channel. The air extracting sub-cavity is further in communication with the liquid cavity through the connection sub-channel. The air extracting sub-cavity is in communication with an object to be subjected to air extraction through the air extracting sub-channel. In addition, an environment sub-channel is further disposed on the air extracting sub-cavity, and the air extracting sub-cavity is in communication with an external environment through the environment sub-channel. The air extractor further includes a switching mechanism for controlling opening and closing of the channel.

[0029] As shown in FIG. 4, air extracting cavities A and B are provided in this embodiment: an air extracting sub-cavity 2A and an air extracting sub-cavity 2B. Correspondingly, the air extracting sub-cavity 2A corresponds to a connection sub-channel 7A, a drainage sub-channel 6A, an air extracting sub-channel 5A, and an environment sub-channel 9A; and the air extracting sub-cavity 2B corresponds to a connection sub-channel 7B, a drainage sub-channel 6B, an air extracting sub-channel 5B, and an environment sub-channel 9B. In this embodiment, a switching mechanism is disposed on each of the drainage sub-channels, the air extracting sub-channels, the connection sub-channels, and the environment sub-channels. As shown in FIG. 4, first switching mechanisms 10A and 10B are disposed on the connection sub-channels 7A and 7B respectively, second switching mechanisms 11A and 11B are disposed on the drainage sub-channels 6A and 6B respectively, third switching mechanisms 12A and 12B are disposed on the air extracting sub-channels 5A and 5B respectively, and fourth switching mechanisms 13A and 13B are disposed on the environment sub-channels 9A and 9B respectively. Continuous air extraction is achieved through the following switching actions:
  1. (1) Open the first switching mechanism 10A, the third switching mechanism 12A, the second switching mechanism 11B and the fourth switching mechanism 13B.
  2. (2) Start the motor, to enable the blades to rotate and form a rotational liquid flow in the liquid cavity. Liquid in the air extracting sub-cavity 2A is extracted into the liquid cavity 1 through the connection sub-channel 7A, and flows into the air extracting sub-cavity 2B through the drainage sub-channel 6B. Meanwhile, air in the air extracting sub-cavity 2B flows into an external environment through the environment sub-channel 9B, and the pressure of the air extracting sub-cavity 2B is basically the same as that of the external environment. Air in the object to be subjected to air extraction 8 is extracted into the air extracting sub-cavity 2A through the air extracting sub-channel 5A.
  3. (3) Before the liquid level of the air extracting sub-cavity 2A decreases to a bottom communication position of the connection sub-channel 7A, close the first switching mechanism 10A, the third switching mechanism 12A, the second switching mechanism 11B, and the fourth switching mechanism 13B, and open the second switching mechanism 11A, the fourth switching mechanism 13A, the first switching mechanism 10B, and the third switching mechanism 12B. Liquid in the air extracting sub-cavity 2B is extracted into the liquid cavity 1 through the connection sub-channel 7B, and flows into the air extracting sub-cavity 2A through the drainage sub-channel 6B. Meanwhile, air in the air extracting sub-cavity 2A flows into an external environment through the environment sub-channel 9A, and the pressure of the air extracting sub-cavity 2A is basically the same as that of the external environment. The air in the object to be subjected to air extraction 8 is extracted into the air extracting sub-cavity 2B through the air extracting sub-channel 5B.
  4. (4) Before the liquid level of the air extracting sub-cavity 2B decreases to a bottom communication position of the connection sub-channel 7B, open the first switching mechanism 10A, the third switching mechanism 12A, the second switching mechanism 11B and the fourth switching mechanism 13B, and close the second switching mechanism 11A, the fourth switching mechanism 13A, the first switching mechanism 10B and the third switching mechanism 12B. The liquid in the air extracting sub-cavity 2A is extracted into the liquid cavity 1 through the connection sub-channel 7A, and flows into the air extracting sub-cavity 2B through the drainage sub-channel 6B. Meanwhile, air in the air extracting sub-cavity 2B flows into an external environment through the environment sub-channel 9B, and the pressure of the air extracting sub-cavity 2B is basically the same as that of the external environment. Air in the object to be subjected to air extraction 8 is extracted into the air extracting sub-cavity 2A through the air extracting sub-channel 5A. Repeat the foregoing (3), thereby achieving continuous extraction of the air in the object to be subjected to air extraction.

Embodiment 3



[0030] In the process of Embodiment 2, all the switching mechanisms are switched at the same time, resulting in a sudden change in pressure in communication with the object to be subjected to air extraction. For example, in step (3) of Embodiment 2, when the third switching mechanism 12A is opened, and the third switching mechanism 12B is closed, the pressure in communication with the object to be subjected to air extraction 8 is suddenly changed from the negative pressure to the environment pressure. The sudden change in pressure is a sign of instability. To suppress the sudden change in pressure, this embodiment optimizes an action sequence of the switching mechanisms as follows:
  1. (1) Open the first switching mechanism 10A, the third switching mechanism 12A, the second switching mechanism 11B and the fourth switching mechanism 13B.
  2. (2) Start the motor, to enable the blades to rotate and form a rotational liquid flow in the liquid cavity 1. The liquid in the air extracting sub-cavity 2A is extracted into the liquid cavity through the connection sub-channel 7A, and flows into the air extracting sub-cavity 2B through the drainage sub-channel 6B. Meanwhile, air in the air extracting sub-cavity 2B flows into the external environment through the environment sub-channel 9B, and the pressure of the air extracting sub-cavity 2B is basically the same as that of the external environment. Air in the object to be subjected to air extraction 8 is extracted into the air extracting sub-cavity 2A through the air extracting sub-channel 5A.
  3. (3) Before the liquid level of the air extracting sub-cavity 2A decreases to a communication position of the connection sub-channel 7A close to the bottom, first, close the first switching mechanism 10A, the second switching mechanism 11B, and the fourth switching mechanism 13B. Then, open the third switching mechanism 12B. Therefore, the air extracting sub-cavity 2A is in communication with the air extracting sub-cavity 2B, and negative pressure is formed in the air extracting sub-cavity 2B. Then, close the third switching mechanism 12A. Then, open the second switching mechanism 11A and the fourth switching mechanism 13A. Therefore, the air extracting sub-cavity 2A is in communication with the external environment. Finally, open the first switching mechanism 10B.
  4. (4) Before the liquid level of the air extracting sub-cavity 2B decreases to a bottom communication position of the connection sub-channel 7B, first, close the first switching mechanism 10B, the second switching mechanism 11A, and the fourth switching mechanism 13A. Then, open the third switching mechanism 12A. Therefore, the air extracting sub-cavity 2A is in communication with the air extracting sub-cavity 2B, and negative pressure is formed in the air extracting sub-cavity 2A. Then, close the third switching mechanism 12B. Then, open the second switching mechanism 11B and the fourth switching mechanism 13B. Therefore, the air extracting sub-cavity 2B is in communication with the external environment. Finally, open the first switching mechanism 10A. Repeat the foregoing (3), thereby achieving continuous extraction of the air in the object to be subjected to air extraction.


[0031] In the foregoing process, when the two air extracting sub-cavities are switched, although the pressure in communication with the object to be subjected to air extraction changes to a certain extent, the phenomenon of the sudden change from the negative pressure to the environmental pressure is avoided, which improves the stability of the air extractor of the present invention. In addition, other switching mechanisms may be disposed in the device of the present invention, to further avoid the sudden change of the negative pressure, for example, in Embodiment 3, after the air extracting sub-channel 5A corresponding to the air extracting sub-cavity 2A is connected to the air extracting sub-cavity 5B corresponding to the air extracting sub-cavity 2B, the sub-channels are connected to the object to be subjected to air extraction through a main air extracting channel, and a main switching mechanism is disposed on the main air extracting channel. When the air extracting sub-cavity needs to be switched, the main switching mechanism is first closed, and then the main switching mechanism is opened after the air extracting sub-cavities 2A and 2B communicate and the pressures of the two are balanced.

Embodiment 4



[0032] Usually, there is air dissolved in liquid. Under negative pressure, the air dissolved in the liquid is separated out to form small air bubbles. In the present invention, negative pressure is formed in a liquid cavity, so that air bubbles are separated from liquid in the liquid cavity. Further, because the density of the air bubbles is less than that of the liquid, the air bubbles gather at a flowing center of rotating liquid, to form an air mass. The air mass occupies the space of the liquid, so that rotary flowing of the liquid cannot be formed at the central region of the liquid cavity, which weakens the negative pressure, and then weakens the air extraction effect of the present invention. To remove the air mass at the center, an air bubble collection cavity 14 as shown in FIG. 5 is designed in this embodiment. The air bubble collection cavity 14 is disposed above the liquid cavity 1, and the air bubble collection cavity 14 is in communication with the liquid cavity 1 through an air bubble channel 15. The air bubble channel 15 is disposed at a rotary flowing center in the liquid cavity 1.

[0033] There is liquid in the air bubble collection cavity 14. When the air bubbles gather at the rotational flow center, the air bubbles move upward under the action of buoyancy, enter the air bubble collection cavity through the air bubble channel 15, and finally gather in the upper space of the air bubble collection cavity 14. Therefore, no air mass is formed in the liquid cavity.

[0034] In this embodiment, the buoyancy of the air bubbles is utilized to separate the separated air from rotary liquid flowing, avoiding gathering of the air mass in the rotary flowing center of the liquid. Further, in this embodiment, a communication position of a connection channel 7 and the liquid cavity 1 is disposed at the lower part of the liquid cavity 1, as shown in FIG. 5. The liquid extracted from the air extracting cavity 2 has an upward flow rate as when flowing into the liquid cavity, which also helps convey the air bubbles to the air bubble collection cavity.

[0035] An air release channel 21 and an air release mechanism 22 are also disposed on the air bubble collection cavity 14 in FIG. 6. The air bubble collection cavity 14 is in communication with the air release mechanism 22 through the air release channel 21. The air release mechanism 22 can discharge the air in the air bubble collection cavity. The air release mechanism 22 may be a switching mechanism. After each use of the air extractor, the switching mechanism of the air release mechanism 22 is opened, so that the air bubble collection cavity 14 is in communication with an external environment. Once the liquid level in the air bubble collection cavity 14 is lower than the liquid level in the air extracting cavity 2, the liquid flows from the air extracting cavity 2 into the air bubble collection cavity 14 under the action of gravity, and extrudes the air in the air bubble collection cavity out, so that the air bubble collection cavity is filled with the liquid once again. The air release mechanism 22 may also be a small vacuum pump. When the air extractor is operating, the vacuum pump is turned on to extract the air out of the air bubble collection cavity.

Embodiment 5



[0036] The liquid in the air extracting cavity 2 is always in contact with the air, so that the air is continuously dissolved into the liquid, the newly dissolved air may be continuously separated out under the condition of a negative pressure of the liquid cavity 1. This may lead to a continuous increase of the air in the liquid cavity 1. In Embodiments 1-3, the air mass gathering at the center of the liquid cavity 1 becomes larger and larger. In Embodiment 4, the volume of the air in the air bubble collection cavity 14 is continuously increased, and finally the air fills the air bubble collection cavity 14 and then overflows into the liquid cavity 1, which is not beneficial to further increase of the negative pressure. Therefore, the present invention further needs to resolve the problem of continuous air separation.

[0037] The solution of the present invention is to reduce contact between the liquid and the air, thereby reducing the amount of air dissolved into the liquid. Using the air extracting cavity in Embodiment 3 as an example, a specific method is shown in FIG. 7. An air-liquid blocker 16 is disposed on the liquid level of the air extracting cavity. The air-liquid blocker 16 is configured to block the contact between the liquid and the air in the air extracting cavity 2, thereby achieving the purpose of reducing or preventing the air from being dissolved into the liquid. The air-liquid blocker 16 may be another liquid that is less dense than the liquid in air extracting cavity 2 and is difficult to dissolve air. For example, the liquid in the air extracting cavity 2 is water, and the air-liquid blocker 16 is oil. The oil floats above the water, blocking the contact between the air and the water and also preventing the air from being dissolved into the water. The air-liquid blocker 16 may also be a solid plate floating on the liquid, or a ball floating on the liquid (as shown in FIG. 8) and capable of moving up and down with the liquid level.

Embodiment 6



[0038] In this embodiment, two liquid cavities are connected in series to enhance the negative pressure for air extraction. As shown in FIG. 9, a liquid cavity a and a liquid cavity b are used. The liquid cavity a is in communication with an air extracting cavity 2 through a connection channel 7a. A drainage channel 6a of the liquid cavity a is in communication with a connection channel 7b of the liquid cavity b. A drainage channel 6b of the liquid cavity b drains liquid outward. If the pressure of the drainage channel 6b is an environmental pressure, the pressure of the connection channel 7a is the sum of negative pressure generated by the two liquid cavities.

[0039] The foregoing description is only one embodiment of the present invention. Based on this idea, the negative pressure for air extraction may be further increased by increasing the number of liquid cavities connected in series in other embodiments of the present invention.

Embodiment 7



[0040] In this embodiment, two liquid cavities are connected in parallel to enhance an air extraction amount. As shown in FIG. 10, a liquid cavity a and a liquid cavity b are used. A drainage channel 7a of the liquid cavity a is in communication with a connection channel 7b of the liquid cavity b, and is in communication with an air extracting cavity 2. A drainage channel 6a of the liquid cavity a is in communication with a drainage channel 6b of the liquid cavity b, to drain liquid outward. The flow of liquid from the air extracting cavity 2 is the sum of the flows of the two liquid cavities, which increases the amount of liquid inflow and also increases the air extraction amount of the air extracting cavity.

[0041] The foregoing description is only one embodiment of the present invention. Based on this idea, the negative pressure for air extraction may be further increased by increasing the number of liquid cavities connected in parallel in other embodiments of the present invention.

[0042] The foregoing descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, and the like made within the spirit and principles of the present invention shall fall into the protection scope of the present invention.


Claims

1. An air extractor, comprising a liquid cavity, an air extracting cavity, a connection channel, a drainage channel and an air extracting channel, wherein the liquid cavity contains rotating liquid, the air extracting cavity has liquid therein, the liquid in the air extracting cavity is in communication with the liquid cavity through the connection channel, the liquid cavity drains the liquid through the drainage channel, a communication position of the connection channel and the liquid cavity is closer to the center of the rotating liquid in the liquid cavity than a communication position of the drainage channel and the liquid cavity, the air extracting cavity is in communication with an object to be subjected to air extraction through the air extracting channel, and air in the object to be subjected to air extraction flows through the air extracting channel into the air extracting cavity.
 
2. The air extractor according to claim 1, wherein the air extracting cavity comprises two or more air extracting sub-cavities, accordingly, corresponding to the air extracting sub-cavities, the drainage channel comprises two or more drainage sub-channels, the air extracting channel comprises two or more air extracting sub-channels, and the connection channel comprises two or more connection sub-channels; the air extracting cavity is in communication with the liquid cavity through the drainage sub-channel; the air extracting sub-cavity is in communication with the liquid cavity through the connection sub-channel; the air extracting sub-cavity is in communication with the object to be subjected to air extraction through the air extracting sub-channel; in addition, an environment channel is further disposed on the air extracting sub-cavities, the environment channel comprises two or more environment sub-channels, and the air extracting sub-cavity is in communication with the external environment through the environment sub-channel; and the air extractor further comprises switching mechanisms for controlling opening and closing of the channels.
 
3. The air extractor according to claim 2, wherein a first switching mechanism is disposed on the connection sub-channel, a second switching mechanism is disposed on the drainage sub-channel, a third switching mechanism is disposed on the air extracting sub-channel, and a fourth switching mechanism is disposed on the environment sub-channel.
 
4. The air extractor according to claim 3, wherein continuous air extraction of the device is achieved through the following switching actions:

(1) Denoting one or more of the air extracting sub-cavities as an air extracting sub-cavity A, opening the corresponding first switching mechanism and third switching mechanism, and meanwhile, closing the corresponding second switching mechanism and fourth switching mechanism, performing operation on one or more of the remaining air extracting sub-cavities and denoting the same as an air extracting sub-cavity B, opening the corresponding second switching mechanism and fourth switching mechanism, and meanwhile, closing the corresponding first switching mechanism and third switching mechanism;

(2) Starting the device, to form a rotational liquid flow in the liquid cavity, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;

(3) Before the liquid level of the liquid in the air extracting sub-cavity A is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity A, closing the first switching mechanism and the third switching mechanism corresponding to the air extracting sub-cavity A and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A and the first switching mechanism and the third switching mechanism corresponding to the air extracting sub-cavity B, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity B through the air extracting sub-channel corresponding to the air extracting sub-cavity B, and causing the liquid to enter the air extracting sub-cavity A through the drainage sub-channel corresponding to the air extracting sub-cavity A;

Repeating (1) to (3) to control opening and closing of the switching mechanisms on the air extracting sub-cavity A and the air extracting sub-cavity B, thereby achieving continuous extraction of the air in the object to be subjected to air extraction.
 
5. The air extractor according to claim 3, wherein continuous air extraction of the device is achieved through the following switching actions:

(1) Denoting one or more of the air extracting sub-cavities as an air extracting sub-cavity A, opening the corresponding first switching mechanism and third switching mechanism, and meanwhile, closing the corresponding second switching mechanism and fourth switching mechanism, performing operation on one or more of the remaining air extracting sub-cavities and denoting the same as an air extracting sub-cavity B, opening the corresponding second switching mechanism and fourth switching mechanism, and meanwhile, closing the first switching mechanism and the third switching mechanism;

(2) Starting the device, to form a rotational liquid flow in the liquid cavity, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;

(3) Before the liquid level of the liquid in the air extracting sub-cavity A is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity A, closing the first switching mechanism corresponding to the air extracting sub-cavity A and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B; and opening the third switching mechanism corresponding to the air extracting sub-cavity B to enable the air extracting sub-cavity A to be in communication with the air extracting sub-cavity B, then closing the third switching mechanism corresponding to the air extracting sub-cavity A, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A and the first switching mechanism corresponding to the air extracting sub-cavity B, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity B through the air extracting sub-channel corresponding to the air extracting sub-cavity B, and causing the liquid to enter the air extracting sub-cavity A through the drainage sub-channel corresponding to the air extracting sub-cavity A;

(4) Before the liquid level of the liquid in the air extracting sub-cavity B is reduced to a communication position between the connection sub-channel and the air extracting sub-cavity B, closing the first switching mechanism corresponding to the air extracting sub-cavity B and the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity A; and opening the third switching mechanism corresponding to the air extracting sub-cavity A to enable the air extracting sub-cavity A to be in communication with the air extracting sub-cavity B, then closing the third switching mechanism corresponding to the air extracting sub-cavity B, and opening the second switching mechanism and the fourth switching mechanism corresponding to the air extracting sub-cavity B and the first switching mechanism corresponding to the air extracting sub-cavity A, thereby extracting the air in the object to be subjected to air extraction into the air extracting sub-cavity A through the air extracting sub-channel corresponding to the air extracting sub-cavity A, and causing the liquid to enter the air extracting sub-cavity B through the drainage sub-channel corresponding to the air extracting sub-cavity B;

Repeating (3) and (4) to achieve continuous extraction of the air in the object to be subjected to air extraction.
 
6. The air extractor according to any one of claims 1-5, wherein an air bubble channel and an air bubble collection cavity are disposed on the liquid cavity, the air bubble collection cavity is in communication with the liquid in the liquid cavity through the air bubble channel, and air bubbles in the liquid cavity enters the air bubble collection cavity through the air bubble channel under the effect of buoyancy.
 
7. The air extractor according to claim 6, wherein the device comprises an air release channel and an air release mechanism, and the air release mechanism is in communication with the air bubble collection cavity through the air release channel, to discharge the air in the air collection cavity.
 
8. The air extractor according to any one of claims 1-7, wherein an air-liquid blocker is disposed in the air extracting cavity, the air-liquid blocker configured to reduce contact between the air and the liquid, and the air-liquid blocker can move up or down with the liquid level of the liquid.
 
9. The air extractor according to any one of claims 1-8, wherein a plurality of liquid cavities are disposed and connected in series, that is, the drainage channel of the preceding liquid cavity is in communication with the connection channel of the following liquid cavity.
 
10. The air extractor according to any one of claims 1-8, wherein a plurality of liquid cavities are disposed and connected in parallel, that is, the connection channels of all the liquid cavities communicate and are in communication with the air extracting cavity, and the drainage channels of all the liquid cavities communicate for draining the liquid.
 




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