Sensor housing

Abstract

The purpose of the present invention is to provide a sensor housing capable of avoiding a measurement error due to air bubbles or the like.　The purpose is achieved by the sensor housing or the like. The sensor housing includes a housing body. The housing body is configured such that a main flow path is formed between an inflow port and an outflow port of a fluid. The main flow path is configured such that a part of the fluid flowing from the inflow port to the outflow port is divided by a specific gravity difference. The housing body includes an optical sensor in a part of the main flow path, and is configured such that the divided fluid again joins the fluid from the main flow path.

Description

Sensor housing

[0001] The present invention relates to a sensor housing.

[0002] Conventionally, a flow cell has been used when measuring the optical characteristics of a fluid using an optical sensor.

[0003] For example, Patent Document 1 describes a flow cell including a liquid inflow path, a liquid outflow path, and a container body.

[0004] International Publication No. 2014 / 027172

[0005] For example, in the flow cell described in Patent Document 1, the ratio of the cross-sectional area of the inflow path to the cross-sectional area of the container body is large, and when the liquid flows into the container body from the inflow path, the flow velocity of the liquid changes significantly, which causes turbulence to occur inside the container body. Furthermore, in the flow cell described in Patent Document 1, since the cross-sectional area changes between the inflow path and the container body, pressure fluctuation occurs between the inflow path and the interior of the container body.

[0006] As described above, in the flow cell described in Patent Document 1, turbulence occurs inside the container body, and pressure fluctuation occurs between the inflow path and the interior of the container body, which results in generation of air bubbles inside the container body. Such generation of air bubbles causes measurement errors in the sensor.

[0007] Accordingly, an object of the present invention is to provide a sensor housing capable of avoiding measurement errors caused by air bubbles.

[0008] The present inventors, while conducting intensive studies to solve the above problem, contemplated that measurement errors could be avoided by performing gas-liquid separation utilizing the difference in specific gravity between a liquid and a gas, and using the degassed liquid as a measurement target for a sensor.

[0009] Based on this idea, the inventors, after repeated trial and error, succeeded in creating a sensor housing that solves the problem of the present invention. This housing separates a portion of the fluid flowing through the main channel of the housing body into gas and liquid phases based on the difference in specific gravity, and measures the liquid from which gas and other substances have been removed, thereby avoiding measurement errors caused by bubbles and the like. The present invention is completed based on this first-of-its-kind idea and successful example made by the inventors.

[0010] In other words, according to each aspect of the present invention, the following embodiments are provided: [1-1] A sensor housing having a housing body, the housing body configured such that a main flow path is formed between a fluid inlet and an outlet, the main flow path is configured such that a portion of the fluid flowing from the inlet to the outlet is separated due to a difference in specific gravity, the housing body is equipped with an optical sensor in a portion of the main flow path, and the separated fluid is configured to rejoin the fluid from the main flow path. [1-2] The sensor housing according to item [1-1], wherein the main flow path has a narrow flow path extending in a straight line, and an optical sensor is provided at the end of the narrow flow path. [1-3] The sensor housing according to item [1-2], comprising a plurality of narrow flow paths, wherein the plurality of narrow flow paths have different flow path lengths. [1-4] The sensor housing according to item [1-2] or [1-3], wherein the housing body is an integrally molded product having a first surface constituting the main flow path and a second surface which is the back surface of the first surface and constituting the narrow flow path, and has through holes penetrating the first surface and the second surface. [1-5] The sensor housing according to any one of items [1-1] to [1-4], wherein the sensor housing has a lid portion that covers the first surface of the housing body and / or a lid portion that covers the second surface of the housing body. [1-6] A method for measuring the optical properties of a fluid using the sensor housing according to any one of items [1-1] to [1-5], comprising the steps of: separating a portion of the fluid in the main flow path that flows from the inlet to the outlet due to a difference in specific gravity; measuring the optical properties of the fluid flowing in the main flow path with the optical sensor; and rejoining the separated fluid with the fluid from the main flow path.[2-1] A sensor housing comprising a housing body, wherein the housing body is configured such that a main flow path is formed between a fluid inlet and an outlet, the main flow path is configured such that a portion of the fluid flowing from the inlet to the outlet is separated due to a difference in specific gravity, the inlet is positioned vertically below the outlet, the housing body has a narrow flow path in a portion of the main flow path having a smaller flow path cross-sectional area than the main flow path, an optical sensor is provided in the narrow flow path for measuring a portion of the fluid with a higher specific gravity that has been separated due to the difference in specific gravity, and the fluid with a higher specific gravity that has been separated due to the difference in specific gravity is configured to merge at the outlet. [2-2] The sensor housing according to item [2-1], wherein the narrow flow path extends in a straight line and is provided with an optical sensor at its end. [2-3] The sensor housing according to item [2-2], comprising a plurality of narrow flow paths, wherein the plurality of narrow flow paths have different flow path lengths. [2-4] The sensor housing according to item [2-2] or [2-3], wherein the housing body is an integrally molded product having a first surface and a second surface which is the back surface of the first surface and constitutes the narrow channel, and has through holes penetrating the first surface and the second surface. [2-5] The sensor housing according to item [2-4], wherein the sensor housing has a lid portion that covers the first surface of the housing body and / or a lid portion that covers the second surface of the housing body. [2-6] A method for measuring the optical properties of a fluid using the sensor housing according to item [2-1], comprising the steps of: separating a portion of the fluid in the main channel flowing from the inlet to the outlet due to a difference in specific gravity; measuring the optical properties of the fluid flowing in the main channel with the optical sensor; and rejoining the separated fluid with the fluid from the main channel.

[0011] According to the present invention, by having a configuration in which the fluid is divided according to the difference in specific gravity, it is possible to measure a fluid from which impurities such as gases, oils, organic matter, and solid matter with low specific gravity have been separated and removed, thereby providing a sensor housing that can avoid measurement errors. Furthermore, according to the present invention, by having a narrow channel that extends in a straight line and an optical sensor equipped at the end of the narrow channel, the narrow channel constitutes the optical path of the optical sensor. Therefore, even if impurities such as gases, oils, organic matter, and solid matter are mixed into the fluid flowing into the optical path, the fluid flow velocity can be increased, so that solid matter does not remain in the optical path but is immediately discharged (flowed out) from the optical path, thereby preventing measurement errors. Furthermore, according to the present invention, the configuration with multiple narrow channels allows for calibration of measurements taken by an optical sensor located in one narrow channel using an optical sensor located in another narrow channel, enabling more precise optical measurements. Additionally, the configuration in which the multiple narrow channels have different channel lengths results in a configuration with different optical path lengths, enabling measurements from high sensitivity to low sensitivity, thus widening the dynamic range. Moreover, the difference in optical path lengths can be used to detect deterioration of the optical sensor or failure of the device itself. Furthermore, according to the present invention, the housing body is a single molded product, resulting in an extremely precise, space-saving, and simple configuration as an optical sensor, reducing the number of parts, thereby improving manufacturing efficiency and providing a high degree of design freedom.

[0012] Figure 1 is a schematic front view of a sensor housing according to one embodiment of the present invention. Figure 2 is a schematic rear view of a sensor housing according to one embodiment of the present invention. Figure 3 is a schematic front view (first surface) of the housing body of the sensor housing in Figure 1. Figure 4 is a schematic rear view (second surface) of the housing body of the sensor housing in Figure 1. Figure 5 is an exploded left side view of the sensor housing shown in Figure 1. Figure 6 is a schematic cross-sectional view taken along line A-A in Figure 3. Figure 7 is an enlarged perspective view showing a part of the housing body (first surface) of the sensor housing in Figure 3. Figure 8 is an enlarged perspective view showing a part of the housing body (second surface) of the sensor housing in Figure 4.

[0013] The details of each aspect of the present invention will be described below, but the present invention can take various forms insofar as it achieves its objective.

[0014] In this specification, unless otherwise specified, each term is used in the sense commonly used by those skilled in the art in the field of water treatment, etc., and should not be interpreted as having an unreasonably restrictive meaning. Furthermore, since the assumptions and theories made herein are based on the inventors' prior knowledge and experience, the present invention is not limited solely to such assumptions and theories.

[0015] "Comprise, contain, include" means that elements other than those explicitly included can be added (synonymous with "at least include"), but it also encompasses "consist of" and "essentially constitute of". In other words, "comprise" can mean that it includes the explicitly included elements and any one or more of those elements, consists of the explicitly included elements, or essentially constitutes the explicitly included elements. "Have" is synonymous with "comprise". Elements include limitations such as parts, means, components, processes, conditions, and parameters. "And / or" means any one of the multiple related items listed, or any combination of two or more or all of them.

[0016] [Summary of the Invention] A sensor housing according to one aspect of the present invention is a housing for measuring the optical properties of a fluid.

[0017] [Overall configuration of the sensor housing] As shown in Figures 1 and 2, a sensor housing 1 according to one aspect of the present invention comprises a housing body 10, a lid portion 11A that covers the first surface 10A of the housing body 10, and a lid portion 11B that covers the second surface 10B, which is the back surface of the first surface 10A of the housing body 10.

[0018] In one aspect of the present invention, the sensor housing 1 is an integrally molded product formed by a ridged surface process. A main channel 20 is formed on the first surface 10A, which is the surface of the housing body 10, and a narrow channel 22, which is a part of the main channel 20, is formed on the second surface 10B, which is the back surface of the housing body 10 (see Figures 3 and 4).

[0019] The lids 11A and 11B are, for example, flat plates, but are not particularly limited as long as they have a structure that can cover and seal the first surface 10A and / or the second surface 10B of the housing body 10. The lid 11A is fixed to the first surface 10A of the housing body 10 using, for example, a fastening member (not shown), and seals the internal space (main flow path 20) between the first surface 10A of the housing body 10 and the lid 11A. The lid 11B is fixed to the second surface 10B of the housing body 10 using, for example, a fastening member (not shown), and seals the internal space (narrow flow path 22) between the second surface 10B of the housing body 10 and the lid 11B.

[0020] [Housing Body Configuration] As shown in Figures 3 to 8, in this embodiment, the housing body 10 has a bottom plate portion 13 and a top plate portion 14 formed in an elongated rectangular shape, a pair of side wall portions 15 (15A, 15B) formed from both ends in the longitudinal direction of the bottom plate portion 13 to both ends in the longitudinal direction of the top plate portion 14, and a back wall portion 16 that extends to close the rectangular frame formed by the connection of the four sides consisting of the bottom plate portion 13, the top plate portion 14 and the pair of side wall portions 15A, 15B.

[0021] A sensor housing 1 according to one aspect of the present invention can be used such that the bottom plate portion 13 is positioned vertically downward and the top plate portion 14 is positioned vertically upward. Hereinafter, the direction from the bottom plate portion 13 to the top plate portion 14 (or the direction from the top plate portion 14 to the bottom plate portion 13) is defined as the "vertical direction," and the longitudinal direction of the bottom plate portion 13 and the top plate portion 14 is defined as the "horizontal direction."In addition, in this specification, the direction in which the bottom plate portion 13 is located is defined as "downward" and the direction in which the top plate portion 14 is located is defined as "upward."In addition, the direction perpendicular to the plane on which Figure 3 is shown is defined as the "front-back direction."

[0022] The housing body 10 has a fluid inlet 12A at one end of the bottom plate portion 13 in the longitudinal direction on the first surface 10A. In this embodiment, the inlet 12A is formed in a cylindrical shape having an internal space that allows fluid to flow into the main flow path 20 from outside the system, and extends from the outer surface of the side wall portion 15A along the longitudinal direction of the bottom plate portion 13. The inlet 12A may also be formed extending upward from the outer surface of the bottom plate portion 13.

[0023] The housing body 10 has a fluid outlet 12B at one end of the top plate portion 14 in the longitudinal direction on the first surface 10A. In this embodiment, the outlet 12B is formed in a cylindrical shape having an internal space that allows the fluid to flow out of the system from the main flow path 20, and extends from the outer surface of the side wall portion 15B along the longitudinal direction of the top plate portion 14. The outlet 12B may also be formed extending upward from the outer surface of the top plate portion 14.

[0024] In one aspect of the present invention, since the fluid to be measured is contained in a tank or container outside the system, it is preferable that the top plate portion 14 of the housing body 10 is positioned vertically below the liquid surface of the fluid contained in the tank or container. For this reason, it is preferable that the inlet 12A and outlet 12B of the housing body 10 be positioned such that the inlet 12A is at the bottom and the outlet 12B is at the top.

[0025] The housing body 10 is configured such that a main flow path 20 is formed between the fluid inlet 12A and the outlet 12B. Here, the main flow path 20 refers to the fluid flow path from the inlet 12A to the outlet 12B.

[0026] The main flow path 20 has an internal space that allows fluid to flow from the inlet 12A to the outlet 12B. Specifically, the main flow path 20 is provided within a region defined by the lid 11, the bottom plate 13, the top plate 14, a pair of side walls 15A and 15B, and the back wall 16. The back wall 16 is formed to close the rear sides of the four sides of the bottom plate 13, the top plate 14, and the pair of side walls 15A and 15B. In other words, the housing body 10 has a structure that has depth in the direction perpendicular to the plane of the paper shown in Figure 3 (front-to-back direction), and this structure forms an internal space that allows fluid to flow from the inlet 12A to the outlet 12B.

[0027] The main flow path 20 is configured such that a portion of the fluid flowing from the inlet 12A to the outlet 12B is separated due to differences in specific gravity. Here, "separated due to differences in specific gravity" means that impurities such as gases, oils, organic matter, and solids with lower specific gravity, contained in the fluid flowing in from the inlet 12A, flow upward and are separated from the fluid with higher specific gravity.

[0028] In this embodiment, the fluid flowing in from the inlet 12A, due to differences in specific gravity, flows upward and is separated from the main flow path 20, where it rejoins with the fluid from the main flow path 20 near the outlet 12B. The separated fluid, containing gases and other substances with low specific gravity, flows vertically upward along the side wall 15A, flows horizontally along the top plate 14 while passing through the slit 18, and is discharged from the outlet 12B (see the dashed arrow in Figure 3).

[0029] Preferably, the main flow path 20 has a narrow flow path 22 extending in a straight line on the second surface 10B, which is the back surface of the first surface 10A, and an optical sensor is provided at the end of the narrow flow path 22. With this configuration, since the narrow flow path 22 constitutes the optical path of the optical sensor, even if impurities such as gases, oils, organic matter, and solids are mixed into the fluid flowing into the optical path, the fluid flow velocity can be increased, so that solids do not remain in the optical path and are immediately discharged (flowed out) from the optical path (narrow flow path 22), thereby preventing measurement errors.

[0030] Here, a narrow channel refers to a channel having a cross-sectional area smaller than that of the main channel. It is not particularly limited as long as it increases the fluid velocity and allows for optical measurement by an optical sensor, but it is preferable to have a narrower inner diameter.

[0031] As mentioned above, the smaller the cross-sectional area of ​​the narrow channel 22, the faster the flow velocity of the fluid being measured, which is preferable. The inner diameter of the narrow channel 22 can be set appropriately depending on the type of fluid being measured, etc., as long as the fluid velocity is increased and optical measurement by an optical sensor is possible, but specifically, it is between 2 mm and 6 mm. Furthermore, by reducing the inner diameter of the narrow channel 22 and increasing the fluid velocity, in addition to the immediate discharge of solids and other particles in the optical path, a cleaning effect on the channel walls and optical sensor within the narrow channel 22 can also be expected due to the fluid flow pressure.

[0032] The narrow channel 22 is formed to extend in a straight line, but in order to separate the fluid flowing in from the main channel 20 into a gas with a lower specific gravity and a fluid with a higher specific gravity (degassed fluid) based on the difference in specific gravity, it is preferable that one end of the narrow channel is formed downwards and the other end is formed upwards. In other words, it is preferable that the narrow channel 22 is formed to extend in the vertical direction (or approximately vertical direction).

[0033] In this embodiment, as shown in Figure 4, two narrow channels 22 (22A, 22B) are provided on the second surface 10B. In the sensor housing of the present invention, the number of narrow channels is not limited, but it is preferable to have multiple channels. By providing multiple narrow channels, it becomes possible to calibrate the measurement by the optical sensor located in one narrow channel with the optical sensor located in the other narrow channel, thereby realizing more precise optical measurements.

[0034] In the housing body 10, the back wall portion 16 has through holes 17 that penetrate the first surface 10A and the second surface 10B for connecting the main flow path 20 and the narrow flow path 22. In this embodiment, there are four through holes 17 (first through holes 17a, 17c and second through holes 17b, 17d). Specifically, the through holes 17 penetrate the thickness direction of the housing body 10 (front-to-back direction in Figure 3), that is, the front and back surfaces of the housing body 10. The placement of the through holes 17 is not limited as long as they penetrate the first surface 10A and the second surface 10B and allow fluid flow from the first surface 10A to the second surface 10B or from the second surface 10B to the first surface 10A.

[0035] In this embodiment, the first through-holes 17 (17a, 17c) are inlets that allow fluid to flow from the first surface 10A to the second surface 10B. The second through-holes 17 (17b, 17d) are outlets that allow fluid to flow from the second surface 10B to the first surface 10A.

[0036] The first through-holes 17 (17a, 17c), which allow fluid to flow from the first surface 10A to the second surface 10B, are preferably positioned below the second through-holes 17 (17b, 17d), which allow fluid to flow from the second surface 10B to the first surface 10A, in order to remove solid matter and other particles from the fluid flowing in the main flow path 20 of the first surface 10A. With this configuration, when the fluid flowing in the main flow path 20 passes through the first through-holes 17 (17a, 17c), gases and other particles with low specific gravity will flow upward, while fluids with high specific gravity (degassed fluid) can flow into the narrow flow path 22 (22A, 22B).

[0037] The narrow channel 22 has an internal space that allows fluid flowing in from the main channel 20 to flow from the first through-hole 17 (17a, 17c), which is the inlet, to the second through-hole 17 (17b, 17d), which is the outlet. Specifically, in this embodiment, the internal space has a rectangular cross-sectional shape (see Figure 6), and the narrow channel 22 is provided within the region defined by the lid portion 11B and the back wall portion 16.

[0038] In this embodiment, the first through-holes 17 (17a, 17c) are formed at one end of the narrow channel 22 formed on the second surface 10B, and the second through-holes 17 (17b, 17d) are formed at the other end of the narrow channel 22 formed on the second surface 10B. Furthermore, one end of the first through-holes 17 (17a, 17c) and the narrow channel 22 (22A, 22B) is positioned downwards, while the other end of the second through-holes 17 (17b, 17d) and the narrow channel 22 (22A, 22B) is positioned upwards.

[0039] In this embodiment, the first through holes 17a and 17c each allow fluid flowing through the main channel 20 to flow from the first surface 10A to the second surface 10B on the back side, and the second through holes 17b and 17d each allow fluid flowing through the narrow channel 22 to flow out from the second surface 10B to the first surface 10A on the back side. More specifically, the first through hole 17a allows fluid flowing through the main channel 20 to flow from the first surface 10A to the second surface 10B on the back side and into the first narrow channel 22A. The second through hole 17b allows fluid flowing through the first narrow channel 22A to flow out from the second surface 10B to the first surface 10A on the back side and into the main channel 20 on the first surface 10A. Similarly, the first through-hole 17c allows the fluid flowing through the main channel 20 to flow from the first surface 10A to the second surface 10B on the back side, and then to flow into the second narrow channel 22B. The second through-hole 17d allows the fluid flowing through the second narrow channel 22B to flow out from the second surface 10B to the first surface 10A on the back side, and then to flow into the main channel 20 on the first surface 10A. With this configuration, the fluid flowing through the main channel 20 on the first surface 10A passes through the first through-holes 17a and 17c and flows through the narrow channels 22 (22A and 22B). At this time, the fluid passing through the first through-holes 17a and 17c becomes degassed because, due to the difference in specific gravity, gases and other substances with a lower specific gravity are separated upwards. Furthermore, the fluid flowing through the narrow channels 22 (22A, 22B) passes through the second through-holes 17b, 17d and flows through the main channel 20 on the first surface 10A.

[0040] It is more preferable that the inner diameter of the narrow channel 22 (22A, 22B) and the diameter of the through holes 17 (17a to 17d) are approximately the same. Therefore, the diameter of the through holes 17 is preferably 2 mm to 6 mm. For example, if the inner diameter of the narrow channel 22 is larger than the diameter of the through holes 17 (especially the first through holes 17a, c which serve as inlets to the second surface 10B), the fluid velocity in the narrow channel 22 will not increase, and the immediate discharge effect of solids and other materials on the optical path will not be obtained. On the other hand, if the inner diameter of the narrow channel 22 is smaller than the diameter of the through holes 17 (especially the first through holes 17a, c which serve as inlets to the second surface 10B), turbulence may occur inside the narrow channel 22, potentially causing measurement errors. The height h of the narrow channel 22 is not particularly limited, but is preferably, for example, 2 mm to 6 mm (see Figure 6).

[0041] The sensor housing 1 of the present invention is a housing body 10 which is a single molded product, and a main flow path 20 is formed on the first surface 10A, and a narrow flow path 22 is formed on the second surface 10B which is the back surface of the first surface 10A. In other words, in the housing body 10, the main flow path 20 and the narrow flow path 22 are in a front-to-back relationship. More specifically, as shown in Figure 6, the back wall portion 16 is formed by embossing, and the protrusion 161A on the first surface 10A becomes the recess 161B on the second surface 10B, and the protrusion 162B on the second surface 10B becomes the recess 162A on the first surface. The recess 162A on the first surface 10A constitutes the main flow path 20, and the recess 161B on the second surface 10B constitutes the narrow flow path 22.

[0042] The height H of the protrusion 161A on the first surface 10A (size in the front-to-back direction in Figure 3) is the same as the height H of the bottom plate 13, top plate 14, and side wall portions 15A and 15B (size in the front-to-back direction in Figure 3) (see Figure 6). With this configuration, the fluid from the inlet 12A flows to the outlet 12B within the region defined by the lid 11A, bottom plate 13, top plate 14, the pair of side wall portions 15A and 15B, and the back wall portion 16, while the lid 11A is fixed to the first surface 10A.

[0043] An optical sensor is provided in a part of the main channel 20. The optical sensor can be placed at any position as long as it is possible to optically measure the fluid flowing through the main channel 20. In this embodiment, the optical sensor is provided in a narrow channel 22 formed on the second surface 10B. More specifically, the first narrow channel 22A has a light-receiving section 31A at one end on the upstream side where the fluid flows and a light-emitting section 30A at the other end on the downstream side where the fluid flows. Similarly, the second narrow channel 22B has a light-receiving section 31B at one end on the upstream side where the fluid flows and a light-emitting section 30B at the other end on the downstream side where the fluid flows. The optical sensor may also have the light-emitting section 30 (30A, 30B) on the upstream side where the fluid flows and the light-receiving section 31 (31A, 31B) on the downstream side. However, from the viewpoint of protecting the substrate of the light-receiving section 31, it is preferable that the light-receiving section 31 is provided on the upstream side where the fluid flows.

[0044] The arrangement relationship between the light-emitting portion 30, the light-receiving portion 31, and the through-holes 17 (first through-holes 17a, 17c and second through-holes 17b, 17d) is not particularly limited. In the present embodiment, the light-emitting portion 30 (30A, 30B) is provided downstream of the second through-holes 17 (17b, 17d), and the light-receiving portion 31 (31A, 31B) is provided upstream of the first through-holes 17 (17a, 17c).

[0045] The light-emitting portion 30 includes, for example, any light-emitting element such as an LED, and is configured to be capable of emitting light toward the fluid flowing in the narrow flow path 22. The light-receiving portion 31 includes, for example, any light-receiving element such as a photodiode, and is configured to receive the light emitted from the light-emitting portion 30. With the above configuration, the light-receiving portion 31 is configured to receive the light emitted from the light-emitting portion 30 and transmitted through the fluid flowing in the narrow flow path 22.

[0046] A recess (not shown) for installing the light-emitting portion 30 is formed on the side wall of the other end of the narrow flow path 22, and the recess can be configured to expose the light-emitting portion 30 into the narrow flow path 22. In addition, a recess (not shown) for installing the light-receiving portion 31 is formed on the side wall of one end of the narrow flow path 22, and the recess can be configured to expose the light-receiving portion 31 into the narrow flow path 22.

[0047] In the sensor housing 1 of the present invention, the arrangement relationship of the plurality of narrow flow paths 22 can be set as appropriate. It is preferable that the position of one end of the second narrow flow path 22B, more specifically the position of the first through-hole 17c, is arranged above the position of one end of the first narrow flow path 22A, more specifically the position of the first through-hole 17a. According to such a configuration, the inflow of solid matter and the like into the second narrow flow path 22B can be more reliably prevented.

[0048] Furthermore, in the sensor housing 1 of the present invention, it is preferable that a plurality of narrow flow paths 22 are provided and the flow path lengths are different from each other. With this configuration, high-sensitivity sensing is possible in a flow path with a long flow path length, that is, an optical path, and low-sensitivity sensing (for example, for low water quality) is possible in a flow path with a short flow path length, that is, an optical path. The dynamic range can be improved by utilizing the difference in light attenuation at different optical path lengths caused by different flow path lengths. Furthermore, by utilizing the difference in optical path length, the present invention can be applied to detection of deterioration of an optical sensor, failure of the device itself, and the like.

[0049] [Other Configurations] In the present embodiment, the first surface 10A (main flow path 20) of the housing body 10 is provided with a plurality of short-circuit flow prevention members 19 (19a, 19b, 19c) for preventing flowing fluid from flowing into the narrow flow paths 22 through short paths without being split according to specific gravity difference. The number, shape, and arrangement positions of the short-circuit flow prevention members are not particularly limited. For example, in the present embodiment, the short-circuit flow prevention member 19a is formed to extend from the bottom plate portion 13 while being inclined relative to the vertical direction, so that the flowing fluid flowing in from the inflow port 12A is prevented from flowing into the first narrow flow path 22A through a short path without being split according to a specific gravity difference. Regarding the short-circuit flow prevention members 19b and 19c, they are also formed to extend from the side surface of the convex portion 161A of the inner back wall portion 16 while being inclined relative to the horizontal direction, so that the fluid flowing out from the second through hole 17b via the first narrow flow path 22A is prevented from flowing into the second narrow flow path 22B through a short path without being split according to a specific gravity difference.

[0050] Furthermore, the short-circuit flow prevention member 19 not only prevents short-circuit flow (short path) of the fluid, but also has the function of capturing and separating solid matter and other particles in the fluid. For example, if the fluid flowing in from the inlet 12A contains solid matter and other particles, these particles are captured by the short-circuit flow prevention member 19a and remain at the base of the short-circuit flow prevention member 19a (near the bottom plate portion 13), preventing them from passing through the first through-hole 17a. Also, for example, if the fluid flowing out from the second through-hole 17b contains solid matter and other particles, these particles are captured by the short-circuit flow prevention members 19b and 19c and remain at the base of the short-circuit flow prevention members 19b and 19c or near the bottom plate portion 13, preventing them from passing through the first through-hole 17c.

[0051] In this embodiment, the housing body 10 has a slit 18 formed on the first surface 10A between the top plate portion 14 and the end of the protrusion 161A, for allowing a gas with a low specific gravity that is diverted from the main flow path 20 to pass through and be discharged from the outlet 12B (see Figure 7). For example, a portion of the fluid flowing in from the inlet 12A is diverted due to the difference in specific gravity, allowing the gas with a low specific gravity to flow upward along the side wall portion 15A and flow out of the outlet 12B along with the fluid through the two slits 18. Similarly, a portion of the fluid flowing out from the second through hole 17b is also diverted due to the difference in specific gravity, allowing the gas with a low specific gravity to flow upward and flow out of the outlet 12B along with the fluid through the slits 18. The position and number of slits 18 are not particularly limited, but it is preferable that they be positioned on the vertically upper side of the housing body 10 so that the gas with a low specific gravity can flow through and be discharged from the outlet 12B.

[0052] For example, the housing body 10 can be made of a metal or plastic with shielding properties. Preferably, the housing body 10 is formed by integral molding using the above-mentioned material. However, the molding material and molding method for the housing body 10 are not limited to these, and for example, a light-shielding material may be used to improve the measurement accuracy of the light-receiving unit 31, or a material that is easy to mold or process may be used, or various other known molding materials and molding methods may be used.

[0053] [Method of Use] The sensor housing 1 according to this embodiment can be used with the bottom plate portion 13 of the housing body 10 positioned vertically downward and the top plate portion 14 positioned vertically upward, with the inlet 12A connected to another upstream flow path and the outlet 12B connected to another downstream flow path. In this case, the other flow path connected to the inlet 12A is connected to a tank or container containing the fluid to be measured, and the sensor housing 1 (especially the top plate portion 14) is positioned lower than the liquid level of the fluid contained in the tank or container. In other words, when using the sensor housing 1 according to this embodiment, the inside of the housing body 10 is always full.

[0054] First, the fluid that flows into the inlet 12A from another upstream channel flows through the main channel 20 on the first surface 10A. Some of the fluid, which has a lower specific gravity, such as gases, oils, organic matter, and other impurities and solids, separates and flows upward, passes through the slit 18, and merges with the fluid flowing through the main channel 20 again before flowing out from the outlet 12B. On the other hand, the fluid with a higher specific gravity flows from the main channel 20 on the first surface 10A through the narrow channel 22 on the second surface 10B, and then flows back through the main channel 20 on the first surface 10A before flowing out from the outlet 12B. More specifically, with respect to fluids with a high specific gravity, the fluid that flows into the inlet 12A from another upstream channel flows through the main channel 20 on the first surface 10A, passes through the first through-hole 17a, and then on the second surface 10B, which is the back surface of the first surface 10A, it passes through the first narrow channel 22A, then through the second through-hole 17b, and flows again through the main channel 20 on the first surface 10A. The fluid that flows out from the second through-hole 17b flows through the main channel 20 on the first surface 10A, passes through the first through-hole 17c, and then on the second surface 10B, which is the back surface of the first surface 10A, it passes through the second narrow channel 22B, then through the second through-hole 17d, and flows again through the main channel 20 on the first surface 10A, and flows out from the outlet 12B and into another downstream channel.

[0055] Furthermore, while the fluid is passing through the narrow channel 22, the light-emitting unit 30 irradiates light onto the fluid passing through the narrow channel 22, and the light-receiving unit 31 receives the light transmitted through the fluid passing through the narrow channel 22. The light intensity value (measured value) received by the light-receiving unit 31 is transmitted to, for example, a control device (not shown), and the water quality, such as turbidity and chromaticity, of the fluid flowing through the sensor housing 1 is measured in the control device.

[0056] The sensor housing 1 according to this embodiment separates the fluid flowing through the main channel 20 into a gas or other substance with a lower specific gravity and a fluid with a higher specific gravity based on the difference in specific gravity. The gas or other substance with a lower specific gravity is diverted upwards, and the fluid with a higher specific gravity is diverted downwards. This configuration allows for the removal of the gas or other substance with a lower specific gravity, thereby avoiding measurement errors. Furthermore, the sensor housing 1 according to this embodiment has a narrow channel 22 that extends in a straight line, and an optical sensor is provided at the end of the narrow channel 22. With this configuration, the narrow channel 22 constitutes the optical path of the optical sensor. Therefore, even if solid matter or the like is mixed into the fluid flowing into the optical path, the fluid flow velocity can be increased, so the solid matter or the like does not remain in the optical path but is immediately discharged (flowed out) from the optical path, thereby preventing measurement errors. Moreover, the sensor housing 1 according to this embodiment is configured to have multiple narrow channels 22. This configuration allows for calibration of measurements taken by an optical sensor located in one narrow channel 22 using an optical sensor located in the other narrow channel 22, thereby enabling more precise optical measurements. Furthermore, the sensor housing 1 according to this embodiment has a configuration in which multiple narrow channels 22 have different channel lengths. As a result, since the optical paths have different lengths, measurements from high sensitivity to low sensitivity are possible, the dynamic range can be widened, and the difference in optical path lengths can be used to detect deterioration of the optical sensor or failure of the device itself. Moreover, the sensor housing 1 according to this embodiment is a one-piece molded product in which the main channel 20 is formed on the surface of the housing body 10 and the narrow channels are formed on the back surface. This configuration results in an extremely precise, space-saving, and simple optical sensor, reducing the number of parts, improving manufacturing efficiency, and providing a high degree of design freedom. In addition, since the sensor housing 1 is detachable, the housing body 10 can be cleaned, and the light-emitting part 30 and light-receiving part 31 can be easily replaced, allowing for repeated use over a long period of time.

[0057] [Method] A method according to one aspect of the present invention is a method for measuring the optical properties of a fluid using a sensor housing according to one aspect of the present invention, comprising the steps of: separating a portion of the fluid in a main channel flowing from an inlet to an outlet due to a difference in specific gravity; measuring the optical properties of the fluid flowing in the main channel with the optical sensor; and rejoining the separated fluid with the fluid from the main channel.

[0058] 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. Furthermore, components and forms from different embodiments may be appropriately combined.

[0059] One aspect of the present invention is a sensor housing that separates and removes gases and the like with a lower specific gravity by utilizing the difference in specific gravity. This configuration avoids measurement errors caused by bubbles and the like, making it useful as an optical property measuring device that can measure water quality more accurately and with higher purity.

[0060] 1 Sensor housing 10 Housing body 10A First surface 10B Second surface 11A Cover 11B Cover 12A Inlet 12B Outlet 13 Bottom plate 14 Top plate 15A Side wall 15B Side wall 16 Back wall 161A Protrusion 161B Recess 162A Recess 162B Protrusion 17 Through hole 18 Slit 19 Short-circuit flow prevention member 20 Main flow path 22 Narrow flow path 30 Light-emitting part 31 Light-receiving part Cross-reference of related applications

[0061] This application claims priority to Japanese Patent Application No. 2025-051525, filed on 26 March 2025, the entirety of which is incorporated herein by reference. Furthermore, the entirety of all documents referenced in the detailed description of the invention of this application, including Patent Document 1, is incorporated herein by reference.

Claims

1. A sensor housing comprising a housing body, wherein the housing body is configured such that a main flow path is formed between a fluid inlet and an outlet, the main flow path is configured such that a portion of the fluid flowing from the inlet to the outlet is separated due to a difference in specific gravity, the housing body is equipped with an optical sensor in a portion of the main flow path, and the separated fluid is configured to rejoin the fluid from the main flow path.

2. The sensor housing according to claim 1, wherein the main flow path has a narrow flow path extending in a straight line, and an optical sensor is provided at the end of the narrow flow path.

3. The sensor housing according to claim 2, comprising a plurality of narrow channels, wherein the plurality of narrow channels have different channel lengths.

4. The sensor housing according to claim 2 or 3, wherein the housing body is an integrally molded product having a first surface that constitutes the main flow path and a second surface that is the back surface of the first surface and constitutes the narrow flow path, and has through holes that penetrate the first surface and the second surface.

5. The sensor housing according to claim 4, wherein the sensor housing has a cover portion that covers a first surface of the housing body and / or a cover portion that covers a second surface of the housing body.

6. A method for measuring the optical properties of a fluid using the sensor housing described in claim 1, comprising the steps of: separating a portion of the fluid in the main channel flowing from the inlet to the outlet due to a difference in specific gravity; measuring the optical properties of the fluid flowing in the main channel with the optical sensor; and rejoining the separated fluid with the fluid from the main channel.

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