Method and apparatus for mixing liquids, and method and apparatus for measuring the physical properties of liquids.

Abstract

The object of the present invention is to provide a liquid mixing method and apparatus that, while having a simple configuration, prevents the generation of bubbles and other contaminants and homogenizes the properties of the liquid in the tank. [Solution] The above objective is to provide a method for mixing liquids, which includes a circulation step of circulating the liquid between a tank and a pipeline connecting the outlet and inlet of the tank, wherein the circulation step involves circulating the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to a gas supply port in the pipeline, and the method and apparatus such that the inner diameter between the outlet and the gas supply port in the pipeline is larger than the inner diameter between the gas supply port and the inlet.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for mixing liquids, as well as a method and apparatus for measuring the physical properties of liquids.

Background Art

[0002] When measuring physical properties of liquids such as pH, turbidity, chromaticity, electrical conductivity, odor, and residual chlorine concentration, generally, a measuring instrument is placed in a tank that houses the measurement target.

[0003] For example, when measuring the residual chlorine concentration of water, an electrode is placed in a tank that houses the water. In the measurement of the residual chlorine concentration, immediately after applying a voltage between the electrodes, the chloride ion concentration of the water around the electrodes locally and temporarily increases. And the chloride ion concentration of the water separated from the electrodes remains low, and the chloride ion concentration of the water in the tank becomes non-uniform. Even if the residual chlorine concentration of the water is measured in such a state, an accurate measurement value in the liquid in the tank cannot be obtained. Moreover, the larger the capacity of the tank that houses the liquid, the more non-uniform the properties of the liquid in the tank become, and measurement errors are likely to occur.

[0004] Therefore, in order to make the properties of the liquid uniform, it is conceivable to stir / mix the liquid housed in the tank (see, for example, Patent Document 1).

[0005] However, when an electrode is placed in the tank, a stirring member such as a stirring blade becomes an obstacle and the arrangement configuration becomes complicated. In addition, since it is necessary to supply power to the stirring device, the device becomes complicated / larger. Moreover, by stirring / mixing the liquid in the tank, bubbles and the like may be generated, which may cause measurement errors, and ultimately high measurement accuracy cannot be maintained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Therefore, the problem that the present invention aims to solve is to provide a liquid mixing method and apparatus that, while having a simple configuration, prevents the generation of bubbles and the like, and homogenizes the properties of the liquid in the tank. [Means for solving the problem]

[0008] While diligently conducting research to solve the above problems, the inventors considered that by mixing the liquid by circulating it—by draining it from the tank and returning it to the tank, rather than stirring the liquid within the tank—the properties of the liquid could be made uniform. Furthermore, they considered that high measurement accuracy could be achieved by measuring a liquid with uniform properties in a bubble-free state.

[0009] Based on these ideas, the inventors, after repeated trial and error, succeeded in creating a method to solve the problems of the present invention, such as a method of mixing liquids by circulating them between a tank and a pipeline outside the tank using gas supplied by a gas supply means in the pipeline. The present invention is completed based on these initial ideas and successful examples made by the inventors.

[0010] In other words, according to each aspect of the present invention, the following embodiments are provided. [1] A method for mixing liquids, The process includes a circulation step in which a liquid is circulated between a tank and a pipeline connecting the outlet and inlet of the tank. The circulation process involves circulating the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to the gas supply port in the pipeline. The method wherein, in the pipeline, the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet. [2] A method for measuring the physical properties of a liquid, A circulation process in which liquid is circulated between a tank and a pipeline connecting the outlet and inlet of the tank, The process includes a measurement step of measuring the physical properties of the liquid in the aforementioned pipeline, The circulation process involves circulating the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to the gas supply port in the pipeline, and The measurement step is a method comprising measuring the physical properties of the liquid in the pipeline using a measuring means provided between the outlet and the gas supply port. [3] Apparatus for mixing liquids, It comprises a tank, a pipeline, and a means for supplying gas, The aforementioned tank is capable of containing liquid, The aforementioned pipeline is arranged to connect the outlet and inlet of the tank, The gas supply means is arranged to be able to supply gas from the gas supply port in the pipeline, and The apparatus wherein, in the pipeline, the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet. [4] Apparatus for measuring the physical properties of a liquid, It comprises a tank, a pipeline, a gas supply means, and a measuring means, The aforementioned tank is capable of containing liquid, The aforementioned pipeline is arranged to connect the outlet and inlet of the tank, The gas supply means is arranged to be able to supply gas from the gas supply port in the pipeline, and The measuring means is arranged to measure the physical properties of the liquid in the pipeline located between the outlet and the gas supply port. [Effects of the Invention]

[0011] According to the present invention, while having a simple configuration, it is possible to prevent the generation of bubbles and the like and to equalize the properties of the liquid in the tank. Further, according to the present invention, since the properties of the liquid in the tank can be equalized and the mixing of bubbles can be avoided, high measurement accuracy can be maintained in the measurement of the physical properties of the liquid.

Brief Description of Drawings

[0012] [Figure 1] FIG. 1 is a schematic configuration diagram showing an apparatus 1A according to a first aspect of the present invention. [Figure 2] FIG. 2 is a schematic configuration diagram showing an apparatus 1B according to a second aspect of the present invention. [Figure 3] FIG. 3 is a partial enlarged view showing a modification of an inlet 12 in an apparatus 1 according to the present invention.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, the details of each aspect of the present invention will be described, but the present invention can take various aspects as long as its object is achieved.

[0014] Each term in this specification is used in the meaning usually used by those skilled in the art such as the water treatment field, unless otherwise specified, and should not be construed as having an unduly limiting meaning. Further, the assumptions and theories made in this specification are based on the inventors' knowledge and experience so far, and the present invention is not limited only by such assumptions and theories.

[0015] "Comprise", "contain", and "include" mean that elements other than those explicitly stated as being included can be added (synonymous with "at least comprise"), and include "consist of" and "essentially consist of". That is, "comprise" can mean including the explicitly stated elements and any one or two or more elements, consisting of the explicitly stated elements, or essentially consisting of the explicitly stated elements. "Have" is synonymous with "comprise". Elements include limitations such as parts, means, components, steps, conditions, parameters, etc. "And / or" means any one of the multiple related items listed, or any combination or all combinations of two or more. Throughout this specification, unless clearly indicated as singular in context, it shall be assumed to include plural items.

[0016] [Summary of the Invention] One aspect of the present invention is a method and apparatus for mixing liquids, which includes a circulation step of circulating a liquid between a tank and a pipeline connecting the outlet and inlet of the tank, and the circulation step is such that the liquid contained in the tank is circulated from the outlet to the inlet by a gas from a gas supply means provided to supply gas to a gas supply port in the pipeline, and the pipeline is such that the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet. Another aspect of the present invention is a method and apparatus for measuring the physical properties of a liquid, which includes a circulation step of circulating a liquid between a tank and a pipeline connecting the outlet and inlet of the tank, and a measurement step of measuring the physical properties of the liquid in the pipeline, and the circulation step is such that the liquid contained in the tank is circulated from the outlet to the inlet by a gas from a gas supply means provided to supply gas to a gas supply port in the pipeline, and the measurement step is to measure the physical properties of the liquid in the pipeline by a measurement means provided between the outlet and the gas supply port.

[0017] In the following, various aspects and embodiments of the present invention will be described with reference to the drawings. In each drawing, elements that are not relevant to the present invention have been omitted. Furthermore, in this specification, the up-and-down direction is defined as the "vertical direction" and the left-and-right direction is defined as the "horizontal direction" in Figures 1 and 2.

[0018] [Apparatus of the first embodiment] Figure 1 is a schematic diagram showing apparatus 1A according to a first aspect of the present invention. Apparatus 1A is a device for circulating and uniformly mixing liquid L, and includes a tank 10, a pipeline 20, and a gas supply means 30.

[0019] The apparatus 1A is configured to circulate liquid L between a tank 10 and a pipeline 20 connecting the outlet 11 and inlet 12 of the tank 10, and to circulate the liquid L contained in the tank 10 from the outlet 11 to the inlet 12 using gas G supplied by a gas supply means 30 that is provided to supply gas to a gas supply port 31 in the pipeline 20.

[0020] Tank 10 is capable of containing liquid L. Liquid L is not particularly limited, but examples include water to be treated such as wastewater, as well as rainwater, surface water, seawater, tap water, and treated water.

[0021] The tank 10 is configured to have a structure that allows for an opening on its vertically upward side. This configuration allows for easy reception of liquid L from outside the tank 10, and also allows for the release of gas G contained in the liquid L inside the tank 10 and gas G contained in the liquid L returned from the pipeline 20. Here, "opening" is a concept that includes not only a state that is always open, but also a structure that is capable of being sealed but allows the tank 10 to be opened by a valve or the like. For example, the tank 10 may be configured to have a semi-closed upper end, as long as it is capable of receiving liquid L and releasing gas G. In other words, the tank 10 may be semi-sealed.

[0022] The tank 10 is provided with an outlet 11 on its vertically downward side for discharging liquid L into the pipeline 20. In this embodiment, the outlet 11 is located at the bottom of the tank 10. Furthermore, the tank 10 is provided with an inlet 12 on its vertically upward side for introducing liquid L into the tank 10. In this embodiment, the inlet 12 is positioned at the upper end of the tank 10, spaced apart from the liquid surface of the liquid L contained within the tank 10. By positioning the inlet 12 spaced apart from the liquid surface, the gas and liquid are separated when the liquid L is returned from the pipeline 20.

[0023] The conduit 20 is configured to connect the outlet 11 and inlet 12 of the tank 10 and is located outside the tank 10. The conduit 20 is configured so that the liquid L contained in the tank 10 can move from one end 201 to the other end 202 of the conduit 20, and has a circular cross-section and a hollow structure.

[0024] One end 201 of the pipeline 20 is connected to the outlet 11 of the tank 10, and the other end 202 of the pipeline 20 corresponds to the inlet 12 of the tank 10.

[0025] In this embodiment, the pipeline 20 is formed to extend from one end 201 to the other end 202 so as to connect the outlet 11 and the inlet 12 of the tank 10. The shape of the conduit 20 is not particularly limited, as long as it is configured to allow the liquid L in the tank 10 to move from the outlet 11 (one end 201) to the inlet 12 (the other end 202). For example, the conduit 20 may be formed to extend from one end 201 to the other end 202 via bends or curves. In this embodiment, specifically, the pipeline 20 has one end 201 that communicates with the outlet 11 of the tank 10, and includes a descending section 20A that extends vertically downward (or diagonally downward) from the one end 201, a horizontal section 20B that communicates with the descending section 20A via a bent section 20F1 and extends horizontally from the bent section 20F1, an ascending section 20C that communicates with the horizontal section 20B via a bent section 20F2 and extends vertically upward from the bent section 20F2, a horizontal section 20D that communicates with the ascending section 20C via a bent section 20F3 and extends horizontally from the bent section 20F3, and a descending section 20E that communicates with the horizontal section 20D via a bent section 20F4 and extends vertically downward (or diagonally downward) from the bent section 20F4.

[0026] Examples of materials for the conduit 20 include plastic materials such as polytetrafluoroethylene, silicon, silicone, and rubber; metallic materials such as stainless steel, titanium, and aluminum; and inorganic materials such as ceramics.

[0027] The gas supply means 30 is arranged to supply gas G to the gas supply port 31 in the pipeline 20. In this embodiment, the gas supply port 31 is positioned to supply gas G to the rising section 20C of the pipeline 20. That is, the gas supply means 30 is positioned such that the gas supply port 31 opens vertically upward at the bend 20F2 between the horizontal section 20B and the rising section 20C of the pipeline 20.

[0028] The gas G supplied from the gas supply means 30 is capable of transferring the liquid L in the pipeline 20 from the outlet 11 to the inlet 12, and can be any gas with low solubility in liquids such as water. For example, air, nitrogen, carbon dioxide, etc. are preferred, and air is more preferred, as they have little effect on the liquid L.

[0029] The gas supply means 30 may be, for example, a blower, a pump, or the like. The gas supply means 30 is preferably an air-lift pump, from the viewpoint of having fewer mechanical moving parts and a simpler configuration compared to a general pressurized pump, thus reducing the risk of wear and failure, and from the viewpoint of having fewer parts in contact with the liquid, thus reducing the risk of corrosion and contamination. In particular, an air-lift pump is preferred because it can maintain uniformity of the properties of the liquid L in the tank 10 because the flow rate (L / min) is constant.

[0030] In the pipeline 20, the inner diameter (d1) between the outlet 11 and the gas supply port 31 is larger than the inner diameter (d2) between the gas supply port 31 and the inlet 12. With this configuration, the liquid L in the pipeline 20 is transferred from the outlet 11 to the inlet 12, and gas G can be supplied so that it circulates between the tank 10 and the pipeline 20. On the other hand, if the inner diameter (d1) between the outlet 11 and the gas supply port 31 is smaller than the inner diameter (d2) between the gas supply port 31 and the inlet 12, some of the gas G from the gas supply means 30 may flow back into the pipeline 20, that is, flow towards one end 201 of the pipeline 20 (the outlet 11 of the tank 10), and there is a risk that gas G will mix into the tank 10. In this embodiment, the inner diameter (d1) of the lowering section 20A and the horizontal section 20B is larger than the inner diameter (d2) of the rising section 20C, the horizontal section 20D, and the lowering section 20E. In this embodiment, this is to ensure that gas G is reliably supplied to the rising section 20C, and that the gas G transfers the liquid L to the inlet 12 and returns it to the tank 10. On the other hand, if the inner diameter (d1) between the outlet 11 of the tank 10 and the gas supply port 31 is smaller than the inner diameter (d2) between the gas supply port 31 and the inlet 12, there is a risk that some of the gas G from the gas supply means 30 will flow back into the pipeline 20, that is, flow out toward one end 201 of the pipeline 20 (the outlet 11 of the tank 10).

[0031] For example, the ratio of the inner diameter (d1) between the outlet 11 and the gas supply port 31 to the inner diameter (d2) between the gas supply port 31 and the inlet 12 is preferably about 3:1 to 6:1. With this configuration, for example in this embodiment, gas G is reliably supplied to the rising section 20C within the internal space of the pipeline 20, and the layer of gas G moves within the pipeline 20 (within the rising section 20C) with the layer of liquid L and the layer of gas G separated (separated), pushing up the layer of liquid L. As a result, liquid L is intermittently discharged at the inlet 12, and after releasing the gas G, the liquid L flows into the tank 10. When liquid L flows into the tank 10 intermittently, it is preferable because the release of gas G is easier compared to when the liquid L in the pipeline 20 flows into the tank 10 mixed with the gas G without separation.

[0032] In this embodiment, it is preferable that the inner diameter of the lowering section 20A is approximately the same as that of the horizontal section 20B. Furthermore, it is preferable that the inner diameters of the horizontal section 20D and the lowering section 20E are approximately the same as those of the rising section 20C.

[0033] In the apparatus 1A described above, the liquid L contained in the tank 10 moves through the downward section 20A and the horizontal section 20B from the outlet 11 (one end 201 of the pipeline 20) located at the bottom of the tank 10 due to the action of gravity. After passing through the horizontal section 20B, the liquid L moves vertically upward through the upward section 20C when gas G is supplied to the gas supply port 31 by the gas supply means 30 at the bend 20F2. After passing through the upward section 20C, the liquid L moves through the horizontal section 20D and the downward section 20E and is discharged from the inlet 12 (the other end 202 of the pipeline 20) and flows into the tank 10.

[0034] According to the apparatus 1A of the first aspect of the present invention, the liquid L in the tank 10 is mixed by circulating it between the tank 10 and the pipeline 20. This configuration, while simple, prevents the generation of bubbles and other imperfections, and makes the properties of the liquid L in the tank 10 uniform. In the apparatus 1A according to the first aspect of the present invention, when liquid L flows into the tank 10 from the inlet 12, some bubbles may be generated as they fall onto the liquid surface in the tank 10. However, due to the difference in specific gravity, the gas G is released at the other end 202 of the pipe 20, so the liquid L in the tank 10, especially the liquid L on the lower vertical side of the tank 10, is degassed.

[0035] [Apparatus of the second embodiment] Figure 2 is a schematic diagram showing apparatus 1B according to a second aspect of the present invention. Apparatus 1B is an apparatus for measuring the physical properties of liquid L. Apparatus 1B includes a tank 10, a pipeline 20, a gas supply means 30, and a measuring means 40.

[0036] In Figure 2, components common to both the apparatus 1A in Figure 1 and the apparatus 1B in Figure 1 are denoted by the same reference numerals. Furthermore, in the following, as a general rule, the differences between the apparatus 1B of the second embodiment and the apparatus 1A of the first embodiment will be described, and the parts that overlap with the apparatus 1A of the first embodiment will not be described.

[0037] The measuring means 40 is positioned to measure the physical properties of the liquid L in the pipeline 20 located between the outlet 11 and the gas supply port 31. Specifically, the measuring means 40 is positioned on the pipeline 20 downstream of one end 201 of the pipeline 20 and upstream of the gas supply port 31 of the gas supply means 30. With this configuration, the liquid L used for measurement by the measuring means 40 does not contain gases G, etc., thus maintaining high measurement accuracy.

[0038] The measuring means 40 may be various sensors for measuring the physical properties of the liquid L, such as pH, turbidity, color, electrical conductivity, odor, and residual chlorine concentration.

[0039] In this embodiment, the measuring means 40 is positioned such that its tip T is in contact with the liquid L in the pipeline 20. Furthermore, it is preferable that the vertical position of the tip T of the measuring means 40 is lower than the vertical position of the gas supply port 31. This configuration makes it possible to suppress the mixing of gas G from the gas supply means 30 into the liquid L being measured by the measuring means 40.

[0040] As described in the first embodiment of apparatus 1A, in apparatus 1B as well, the inner diameter (d1) between the outlet 11 and the gas supply port 31 is larger than the inner diameter (d2) between the gas supply port 31 and the inlet 12.

[0041] In the apparatus 1B described above, the liquid L contained in the tank 10 moves through the downward section 20A and the horizontal section 20 from the outlet 11 (one end 201 of the pipe 20) located at the bottom of the tank 10 due to the action of gravity, and is subjected to physical property measurement by the measuring means 40. After being subjected to physical property measurement, the liquid L moves vertically upward through the upward section 20C when gas G is supplied to the gas supply port 31 by the gas supply means 30. The liquid L that has passed through the upward section 20C moves through the horizontal section 20D and the downward section 20E and is discharged from the inlet 12 (the other end 202 of the pipe 20) and flows into the tank 10.

[0042] According to the apparatus 1B of the second aspect of the present invention, the properties of the liquid L in the tank 10 can be made uniform by circulating the liquid L in the tank 10 between the tank 10 and the pipeline 20, so that the properties of the liquid L in the tank 10 can be accurately measured when measuring physical properties by the measuring means 40, and since the measurement can be performed without air bubbles in the liquid L, high measurement accuracy can be maintained.

[0043] [Differentiation] The present invention is not limited to the embodiments described above, and modifications and improvements are possible to the extent that the objectives of the present invention can be achieved. For example, as shown in Figure 3, the inlet 12 of the apparatus 1 (the other end 202 of the conduit 20) may be in contact with or immersed in the liquid surface of the liquid L contained in the tank 10, provided that it has a mechanism for separating the liquid L and gas G in the conduit 20. In the example of Figure 3(a), the inlet 12 is immersed in the liquid L contained in the tank 10, and a through-hole for releasing the gas G is formed near the other end 202 of the conduit 20. In this example, the liquid L in the conduit 20 flows into the tank 10 from the inlet 12, and the gas G in the conduit 20 is released from the through-hole. In the example of Figure 3(b), the inlet 12 has a cross-section that is inclined with respect to the liquid surface of the liquid L contained in the tank 10, with a portion immersed in the liquid L contained in the tank 10 and a portion separated from the liquid surface of the liquid L contained in the tank 10. In this example, the liquid L in the pipeline 20 flows into the tank 10 from the inlet 12, and the gas G in the pipeline 20 is released from the space between the inlet 12, which is separated from the liquid surface, and the liquid surface.

[0044] [Another aspect of the present invention] Another aspect of the present invention is a method for mixing liquids, comprising a circulation step of circulating the liquid between a tank and a pipeline connecting the outlet and inlet of the tank, wherein the circulation step circulates the liquid contained in the tank from the outlet to the inlet with gas supplied by a gas supply means provided to supply gas to a gas supply port in the pipeline, and in the pipeline, the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet. The method according to another aspect of the present invention can be realized by using apparatus 1A according to the first aspect. Furthermore, yet another aspect of the present invention is a method for measuring the physical properties of a liquid, comprising a circulation step of circulating the liquid between a tank and a pipeline connecting the outlet and inlet of the tank, and a measurement step of measuring the physical properties of the liquid in the pipeline, wherein the circulation step circulates the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to a gas supply port in the pipeline, and the measurement step circulates the physical properties of the liquid in the pipeline using a measurement means provided between the outlet and the gas supply port. The method according to yet another aspect of the present invention can be realized by using apparatus 1B according to the second aspect.

[0045] It should be noted that the present invention is not limited to any of the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components from all the components shown in the embodiments may be modified by addition, deletion, substitution, etc. Moreover, components and forms from different embodiments may be appropriately combined. [Industrial applicability]

[0046] An apparatus and method according to one aspect of the present invention, which mixes the liquid in a tank by circulating it between the tank and a pipeline, has a simple configuration that prevents the generation of bubbles and other imperfections and can homogenize the properties of the liquid in the tank. Therefore, it can be used as a means of homogenizing the properties of liquids in a wide range of devices, such as water treatment devices and water purification devices. [Explanation of Symbols]

[0047] 1 device 10 tanks 11 Outlet 12 Inlet 20 conduit 20A descending section 20B Horizontal part 20C Ascent 20D horizontal section 20E Descending part 20F bent part 201 One end 202 Other end 30 Gas supply means 31 Gas supply port 40 Measurement means L liquid G gas T Tip of measuring means

Claims

1. A method for measuring the physical properties of a liquid, A circulation process in which liquid is circulated between a tank and a pipeline connecting the outlet and inlet of the tank, The process includes a measurement step of measuring the physical properties of the liquid in the aforementioned pipeline, The circulation process involves circulating the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to the gas supply port in the pipeline. The measurement step involves measuring the physical properties of the liquid in the pipeline using a measuring means provided between the outlet and the gas supply port. The method wherein the inlet has a gas-liquid separation mechanism.

2. A method for measuring the physical properties of a liquid, A circulation process in which liquid is circulated between a tank and a pipeline connecting the outlet and inlet of the tank, The process includes a measurement step of measuring the physical properties of the liquid in the aforementioned pipeline, The circulation process involves circulating the liquid contained in the tank from the outlet to the inlet using gas supplied by a gas supply means provided to supply gas to the gas supply port in the pipeline. The measurement step involves measuring the physical properties of the liquid in the pipeline using a measuring means provided between the outlet and the gas supply port. The inlet has a gas-liquid separation mechanism, The method wherein, in the pipeline, the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet.

3. An apparatus for measuring the physical properties of a liquid, It comprises a tank, a pipeline, a gas supply means, and a measuring means, The aforementioned tank is capable of containing liquid, The aforementioned pipeline is arranged to connect the outlet and inlet of the tank, The gas supply means is arranged to be able to supply gas from the gas supply port in the pipeline. The measuring means is arranged to be capable of measuring the physical properties of the liquid in the pipeline between the outlet and the gas supply port. The apparatus, wherein the inlet has a gas-liquid separation mechanism.

4. An apparatus for measuring the physical properties of a liquid, It comprises a tank, a pipeline, a gas supply means, and a measuring means, The aforementioned tank is capable of containing liquid, The aforementioned pipeline is arranged to connect the outlet and inlet of the tank, The gas supply means is arranged to be able to supply gas from the gas supply port in the pipeline. The measuring means is arranged to be capable of measuring the physical properties of the liquid in the pipeline between the outlet and the gas supply port. The inlet has a gas-liquid separation mechanism, The apparatus wherein, in the pipeline, the inner diameter between the outlet and the gas supply port is larger than the inner diameter between the gas supply port and the inlet.

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