Liquid suction apparatus

Abstract

To suppress disturbance of an interface between upper and lower layers of liquid as much as possible when discharging an upper layer of liquid from a container in which the upper and lower layers of liquid are stored.SOLUTION: A liquid suction apparatus 10 is configured to draw out an upper layer of liquid L1 from a container 50 in which upper and lower layers of liquid (L2, L1) are stored. The liquid suction apparatus 10 includes: a siphon tube 11 comprising a suction tube 21 inserted into the container 50 and a discharge tube 22 for connection to the suction tube 21; a connection tube 12 for connection to an intermediate portion of the siphon tube 11; and a negative pressure imparting section 13 for applying negative pressure to the interior of the connection tube 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid suction device. [Background technology]

[0002] The following processes may be carried out to remove impurities from liquids (liquid products) stored in containers such as tanks. When a liquid (liquid product) is stored in a container, a cleaning solution such as water is supplied to the container, and impurities contained in the liquid are extracted into the cleaning solution.The liquid and the cleaning solution are separated at the interface inside the container, and the upper layer of cleaning solution is discharged out of the container. BACKGROUND ART For example, the technology disclosed in Patent Document 1 is known as a technology for sucking out liquid from a container such as a tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 5-69379 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when the liquid (liquid product) and the cleaning liquid are separated at the interface and the upper layer of cleaning liquid is discharged out of the container, it is desirable to avoid disrupting the interface formed between the upper and lower layers as much as possible. Conventionally, a pump such as a vacuum pump or a self-priming pump is used to suck liquid out of a container such as a tank. If the entire upper layer of cleaning liquid is sucked out using the pump as described above, the interface may be disrupted by pulsation caused by the operation of the pump.

[0005] Therefore, the present disclosure aims to provide a liquid suction device that can minimize disruption of the interface between the upper and lower layers of liquid when discharging the upper layer of liquid from a container in which the upper and lower layers of liquid are stored. [Means for solving the problem]

[0006] The present invention is a liquid suction device for extracting an upper layer of liquid from a container in which two layers of liquid are stored, and includes a siphon tube having a suction tube that is inserted into the container and a discharge tube that is connected to the suction tube, a connecting tube that is connected to the middle of the siphon tube, and a negative pressure applying unit that creates a negative pressure inside the connecting tube. [Effects of the Invention]

[0007] According to the liquid suction device of the present invention, when discharging the upper layer liquid from a container in which two layers of liquid are stored, it is possible to prevent the interface between the upper and lower layers of liquid from being disrupted as much as possible. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of an example of a liquid suction device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Outline of the embodiment of the present invention> Hereinafter, an outline of an embodiment of the present invention will be listed and described. (1) The present invention is a liquid suction device for extracting an upper layer of liquid from a container in which two layers of liquid are stored, the device comprising: a siphon tube having a suction tube inserted into the container and a discharge tube connected to the suction tube; a connecting tube connected to the middle of the siphon tube; and a negative pressure applying unit for creating a negative pressure inside the connecting tube.

[0010] In this liquid suction device, the suction tube of the siphon tube is inserted into a container, and with the tip (lower end) of the suction tube positioned above and close to the interface between the two liquid layers, a negative pressure is applied to the connecting tube connected to the middle of the siphon tube. This causes the upper liquid in the container to naturally drain through the siphon tube due to the siphon principle. The upper liquid is steadily discharged from the container, making it possible to minimize disruption of the interface between the upper and lower liquid layers.

[0011] (2) The negative pressure applying unit may be a pump driven by a motor, but it is preferable that the negative pressure applying unit is an air ejector. The air ejector does not vibrate as much as a motor-driven pump, and it is possible to prevent the interface from collapsing from the moment the upper layer liquid starts to be discharged.

[0012] (3) In the liquid suction device of (1) or (2) above, in order to obtain the siphon principle, the open end located at the most downstream position of the discharge pipe may be located lower than the opening at the tip (lower end) of the suction pipe, but it is preferable that the open end located at the most downstream position of the discharge pipe be located lower than the container. Even if the height of the interface between the two liquid layers changes, the above-described configuration makes it possible to discharge the liquid by the siphon principle.

[0013] (4) Any one of the liquid suction devices (1) to (3) has a support part that supports the suction tube so that it can be displaced in the vertical direction, and the siphon tube has flexible piping between the suction tube and the discharge tube. Even if the height of the interface between the two liquid layers changes, the vertical position of the suction pipe is changed accordingly. Even if the position of the suction pipe is changed, the flexible piping means that the vertical position of the discharge pipe (its most downstream open end) does not need to be changed.

[0014] (5) The liquid suction device of (2) includes a first opening / closing valve provided in the connecting pipe; The air ejector includes an air source that supplies air to the air ejector and a second opening / closing valve that is provided between the air ejector and the air ejector. According to this configuration, the upper layer liquid can be discharged by switching the open / closed states of the first open / close valve and the second open / close valve.

[0015] (6) In the liquid suction device of (5), the first opening / closing valve and the second opening / closing valve are opened, the air ejector is operated, and when the upper layer liquid starts to be discharged through the siphon tube, the first opening / closing valve is closed. With this configuration, when the air ejector creates a negative pressure in the connecting pipe and the upper layer liquid starts to be discharged through the siphon pipe due to the siphon principle, the first on-off valve is closed, thereby preventing the liquid from flowing into the connecting pipe.

[0016] <Details of the embodiment of the present invention> Hereinafter, the details of the embodiments of the present invention will be described. [Overall configuration of the liquid suction device] FIG. 1 is a diagram showing the configuration of an example of a liquid suction device of the present invention. In order to remove impurities from the liquid (liquid product L1) stored in a container 50 such as a tank, the following treatment is carried out. While the liquid product L1 is stored in the container 50, a cleaning liquid L2 such as water is supplied to the container 50, and impurities contained in the liquid product L1 are extracted into the cleaning liquid L2. The cleaning liquid L2 has a different specific gravity from the liquid product L1, and in this embodiment, the liquid product L1 and the cleaning liquid L2 undergo interfacial separation within the container 50. The specific gravity of the liquid product L1 is greater than that of the cleaning liquid L2, and the liquid product L1 becomes the lower layer within the container 50. The upper layer cleaning liquid L2 is then pumped out of the container 50.

[0017] 1 is used to pump the upper layer cleaning liquid L2 out of the container 50. In other words, the liquid suction device 10 is a device for removing the upper layer liquid (cleaning liquid L2) from the container 50 in which two upper and lower layers of liquid (cleaning liquid L2 and liquid product L1) are stored.

[0018] The liquid (liquid product L1) contained in the container 50 is not particularly limited. The liquid (liquid product L1) is, for example, a surfactant or a solution that is a raw material for cosmetics. The liquid that forms the upper layer may be other than the cleaning liquid L2. If it is the cleaning liquid L2, it may be any liquid other than water as long as it has a cleaning effect on the liquid product L1.

[0019] Regarding the flow direction of the cleaning liquid L2 pumped out from the container 50 by the liquid suction device 10 of this embodiment, the container 50 side is the "upstream side," and the opposite side, the opening end 221 side of the discharge pipe 22 described below, is the "downstream side." The liquid suction device 10 includes a siphon tube 11, a connecting tube 12, and a negative pressure applying unit 13.

[0020] The siphon tube 11 has a suction tube 21 that is inserted into the container 50, and a discharge tube 22 that is connected to the suction tube 21. The siphon tube 11 shown in FIG. 1 further has a flexible pipe 23 between the suction tube 21 and the discharge tube 22. In other words, the discharge tube 22 is connected to the suction tube 21 via the flexible pipe 23. The siphon tube 11 is made of a metal such as stainless steel, but may also be made of a resin.

[0021] The suction tube 21 has a straight tube 31 and a curved tube 32 connected to the upper part of the straight tube 31. The straight tube 31 is a long section in the vertical direction and is inserted into the container 50 through an opening 52 provided in the top plate 51 of the container 50. The lower end of the straight tube 31 is the tip 211 of the suction tube 21, which serves as a suction port for the liquid (cleaning liquid L2). As shown in FIG. 1, the tip 211 of the suction tube 21 is located above and close to the interface K between the two liquid layers (the interface K between the liquid product L1 and the cleaning liquid L2).

[0022] The flexible pipe 23 is connected to the downstream end of the curved pipe 32 . The discharge pipe 22 has an upstream first pipe section 41, an intermediate second pipe section 42, and a downstream third pipe section 43. The first pipe section 41 is connected to the downstream end section 231 of the flexible piping 23. The discharge pipe 22 has an open / close valve 44.

[0023] In this embodiment, the first pipe portion 41 extends horizontally, and the second pipe portion 42 bends from the first pipe portion 41 and extends vertically downward. The third pipe portion 43 bends from the second pipe portion 42 and extends horizontally. The downstream end of the third pipe portion 43 is the open end 221 of the discharge pipe 22. The open end 221 is open to the atmosphere and serves as a discharge port for the liquid (cleaning liquid L2). The open end 221, which is located at the most downstream position of the discharge pipe 22, is located lower than the container 50. Although not shown, the third pipe portion 43 may be omitted. In this case, the lower end of the second pipe portion 42 becomes the open end 221 located at the most downstream side of the discharge pipe 22.

[0024] Flexible piping 23 connects suction pipe 21 and discharge pipe 22 and allows displacement of suction pipe 21 and discharge pipe 22. The heightwise position of suction pipe 21 is changed according to the heightwise position of interface K. With flexible piping 23, even if the position of suction pipe 21 is changed, the position of discharge pipe 22 does not need to be changed. In other words, the position of open end 221 does not change.

[0025] The connecting pipe 12 is a pipe that is connected to the middle of the siphon pipe 11. In the present embodiment, a branch portion 24 is provided in the discharge pipe 22 (first pipe portion 41), and the connecting pipe 12 is connected to the branch portion 24. The connecting pipe 12 is made of a metal such as stainless steel, but may also be made of a resin. The liquid suction device 10 has a first on-off valve 16 provided in the connecting pipe 12. The first on-off valve 16 is a valve that can be switched selectively between an open state that allows fluid to pass through the connecting pipe 12 and a closed state that prevents fluid from passing through the connecting pipe 12. The opening and closing operation may be electric or manual.

[0026] The negative pressure applying unit 13 is a device for applying a negative pressure to the inside of the connecting pipe 12. The negative pressure applying unit 13 in this embodiment is an air ejector, and will be described below as the "air ejector 13." An air pipe 27 is connected to the connecting pipe 12, and the air ejector 13 is configured at the connection between the connecting pipe 12 and the air pipe 27. An air source 19 is connected to one end of the air pipe 27, and the other end of the air pipe 27 is open to the atmosphere. The fluid (air or cleaning liquid L2) flowing out from the open end of the air pipe 27 is received in a spare container 29.

[0027] The air source 19 is, for example, a compressor, and supplies air to the air ejector 13. The air from the air source 19 flows through the air piping 27 and passes through the air ejector 13, creating a negative pressure inside the connecting pipe 12. At this time, the first opening / closing valve 16 is in an open state, and the second opening / closing valve 17 provided on the air piping 27 is in an open state. The second on-off valve 17 is located between the air source 19 and the air ejector 13. The second on-off valve 17 is a valve that can be selectively switched between an open state that allows air to pass through and a closed state that prevents air from passing through the air piping 27. The opening and closing operation may be electrically operated or manual.

[0028] The liquid suction device 10 shown in Figure 1 has a support part 14 that supports the suction tube 21 so that it can be displaced in the vertical direction. The support part 14 supports the suction tube 21 so that it can be displaced in the vertical direction relative to the container 50. The support part 14 is attached, for example, to a portion of the container 50 that has an opening 52. The support part 14 has a cylindrical member 141 and a packing (gland packing) 142 provided inside the cylindrical member 141. The packing 142 allows sliding between the support part 14 and the suction tube 21 (straight tube 31), and the support part 14 supports the suction tube 21 (straight tube 31) so that it can be displaced.

[0029] A liquid suction method for extracting the upper layer cleaning liquid L2 from the container 50 using the liquid suction device 10 having the above configuration will now be described. As described above, liquid suction device 10 has siphon tube 11, connecting tube 12 connected to the middle of siphon tube 11, and air ejector (negative pressure applying unit) 13 for creating a negative pressure inside connecting tube 12. Siphon tube 11 has suction tube 21 inserted into container 50, and discharge tube 22 connected to suction tube 21.

[0030] In the container 50, the liquid product L1 in the lower layer and the cleaning liquid L2 in the upper layer are separated at the interface. The suction tube 21 of the siphon tube 11 is inserted into the container 50. The tip (lower end) 211 of the suction tube 21 is located above and close to the interface K between the two layers of liquid (liquid product L1, cleaning liquid L2). In this state, air is supplied from the air source 19 to the air ejector 13, creating a negative pressure in the connecting pipe 12 connected to the middle of the siphon pipe 11. At this time, the valve 44 of the discharge pipe 22 is in a closed state.

[0031] As a result, the pressure in the siphon tube 11 (particularly the suction tube 21) connected to the connecting tube 12 becomes lower than the pressure inside the container 50, and the cleaning liquid L2 in the upper layer inside the container 50 is sucked up through the suction tube 21. Note that the container 50 in this embodiment is closed by a top plate 51, but the top plate 51 is provided with an air vent 55, and the pressure inside the container 50 is equal to atmospheric pressure.

[0032] When the cleaning liquid L2 in the upper layer in the container 50 is sucked up through the suction pipe 21 and a flow of the cleaning liquid L2 occurs, the valve 44 of the discharge pipe 22 is opened. Most of the cleaning liquid L2 sucked up along the suction pipe 21 flows into the discharge pipe 22 and is discharged from the open end 221 thereof. In this way, due to the siphon principle, the cleaning liquid L2 is naturally discharged through the siphon tube 11. Due to the siphon principle, the cleaning liquid L2 is discharged stably, and it is possible to prevent the interface K between the upper and lower liquid layers from being disrupted as much as possible. Since the cleaning liquid L2 is discharged due to the siphon principle, it is possible to save power.

[0033] In order to suck up the cleaning liquid L2 along the suction pipe 21, the valve 44 of the discharge pipe 22 is closed, and the first opening / closing valve 16 and the second opening / closing valve 17 are opened, causing the air ejector 13 to function. Thereafter, as described above, the valve 44 of the discharge pipe 22 is opened, and once the discharge of the cleaning liquid L2 through the siphon pipe 11 begins, the first opening / closing valve 16 is closed. In this way, the connecting pipe 12 is put into a negative pressure by the air ejector 13, and once the discharge of the cleaning liquid L2 through the siphon pipe 11 begins according to the siphon principle, the first opening / closing valve 16 is closed. This makes it possible to prevent the cleaning liquid L2 from flowing toward the connecting pipe 12. After the first opening / closing valve 16 is closed, the second opening / closing valve 17 is closed.

[0034] The container 50 has a glass wall 53 on a part of its side wall surface, which makes it possible to check the position of the interface K from outside the container 50, and also to check that the cleaning liquid L2 has been discharged. As the cleaning liquid L2 is dispensed, its liquid level gradually drops, and when the liquid level reaches the tip 211 of the suction tube 21, the discharge of the cleaning liquid L2 according to the siphon principle is stopped. This completes the discharge of the cleaning liquid L2.

[0035] An outlet pipe 57 is connected to the bottom of the container 50, which allows the liquid product L1 in the lower layer to flow out of the container 50. The outlet pipe 57 has an on-off valve 58. When the on-off valve 58 is closed, the liquid product L1 and the cleaning liquid L2 are stored in the container 50. When the on-off valve 58 is opened, the liquid product L1 can be allowed to flow out.

[0036] 〔others〕 Although not shown, the negative pressure applying unit for applying a negative pressure to the inside of the connecting pipe 12 may be a pump driven by a motor. However, in the case of the liquid suction device 10 of this embodiment, the negative pressure applying unit is the air ejector 13. The air ejector 13 does not vibrate as compared with a motor-driven pump, and it is possible to prevent the interface K from collapsing from the time when the upper layer cleaning liquid L2 starts to be discharged. Furthermore, even if the liquid suction device 10 needs to have explosion-proof performance depending on the liquid product L1 stored in the container 50, the adoption of the air ejector 13 makes this easy.

[0037] To utilize the siphon principle, the open end 221 located at the most downstream position of the discharge pipe 22 needs to be located lower than the opening of the tip (lower end) 211 of the suction pipe 21. In the case of the liquid suction device 10 of this embodiment, the open end 221 of the discharge pipe 22 is located lower than the container 50. With this configuration, even if the height of the interface K between the two liquid layers changes, the upper layer cleaning liquid L2 can be discharged due to the siphon principle.

[0038] As described above, the liquid suction device 10 of this embodiment has the support part 14 that supports the suction tube 21 so that it can be displaced in the vertical direction. The siphon tube 11 has the flexible piping 23 between the suction tube 21 and the discharge tube 22. With this configuration, even if the height of the interface K between the two liquid layers changes, it is possible to change the vertical position of the suction pipe 21 according to that height. Furthermore, even if the position of the suction pipe 21 is changed, the flexible piping 23 makes it unnecessary to change the vertical position of the discharge pipe 22 (its most downstream open end 221).

[0039] In the above embodiment, the liquid in the container 50 is described as a case where the lower layer is the liquid product L1 and the upper layer is the cleaning liquid L2, and the liquid suction device 10 sucks in and sends out the cleaning liquid L2 in the upper layer to the outside of the container 50. However, the present invention may be configured such that, due to the relationship of specific gravity, the lower layer is the cleaning liquid and the upper layer is the liquid product, and the liquid suction device 10 sucks in and sends out the liquid product in the upper layer to the outside of the container 50.

[0040] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is not limited to the above-described embodiments, and includes all modifications within the scope of equivalents to the configurations described in the claims. [Explanation of symbols]

[0041] 10 Liquid suction device 11 Siphon tube 12 Connecting pipe 13 Air ejector (negative pressure applying part) 14 Support part 16 First opening and closing valve 17 Second opening and closing valve 19 Air source 21 Suction tube 22 Discharge pipe 23 Flexible piping 50 containers 221 Open end L1 Liquid product (lower layer liquid) L2 Cleaning liquid (upper layer liquid)

Claims

1. A liquid suction device for extracting an upper layer of liquid from a container in which two layers of liquid are stored, a siphon tube having a suction tube inserted into the container and a discharge tube connected to the suction tube; a connecting pipe connected to the middle of the siphon pipe; a negative pressure applying unit for applying a negative pressure to the inside of the connecting pipe; A liquid suction device comprising:

2. The liquid suction device according to claim 1 , wherein the negative pressure applying unit is an air ejector.

3. 3. The liquid suction device according to claim 1, wherein the open end located at the most downstream side of the discharge pipe is located at a position lower than the container.

4. a support portion that supports the suction tube so that the suction tube can be displaced in the up and down direction; 3. The liquid suction device according to claim 1, wherein the siphon tube has a flexible pipe between the suction tube and the discharge tube.

5. a first opening / closing valve provided in the connecting pipe; The liquid suction device according to claim 2 , further comprising: a second opening / closing valve provided between an air source that supplies air to the air ejector and the air ejector.

6. The first opening / closing valve and the second opening / closing valve are opened to operate the air ejector; When the upper layer liquid starts to be discharged through the siphon tube, the first on-off valve is closed. The liquid suction device according to claim 5.

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