JP7773968B2 - Floating object observation device - Google Patents

Description

The present invention relates to a floating matter observation device for observing floating matter in a liquid to be observed.

As shown in Figure 10, one example of a conventional floating matter observation device of this type is a floating matter observation device 101 that observes flocs 106 in raw water 105. The floating matter observation device 101 is equipped with a laser light source 104 that irradiates the water surface 103 with sheet laser light 102, and a camera 107 that is located above the water surface 103 and captures images of flocs 106 in the raw water 105 that are irradiated with the sheet laser light 102 incident from the water surface 103.

The laser light source 104 and camera 107 are housed in a case 108. A lower end opening 109 that opens below the water surface 103 is formed at the lower end of the case 108.

The imaging range 110, in which the camera 107 images the flocs 106 irradiated with the sheet laser light 102, is set in an area below the lower end opening 109. The sheet laser light 102 passes from inside the case 108 through the lower end opening 109 and reaches the imaging range 110. The sheet laser light 102 is then reflected by the flocs 106 in the raw water 105, and the reflected laser light 111 travels from the imaging range 110 through the lower end opening 109, enters the case 108, and reaches the camera 107.

As a result, the imaging range 110 is set below the water surface 103 in an area below the lower end opening 109, so even if it is difficult for the flocks 106 to flow into the case 108 from the lower end opening 109, the camera 107 can reliably capture images of the flocks 106 in the area below the lower end opening 109.

In addition, when the floating object observation device 101 is installed outdoors, external light 112 such as sunlight (light other than the sheet laser light 102) is blocked by the case 108, preventing the external light 112 from entering the camera 107.

The floating object observation device 101 described above is described, for example, in Patent Document 1 below.

Patent Publication No. 2022-94367

However, with the above-mentioned conventional system, when the raw water 105 is highly transparent (for example, in the case of purified water), external light 112 enters the water surface 103 from outside the case 108 and is reflected by the flocs 106 in the raw water 105 or the walls or bottom of the tank (not shown). If the reflected external light 113 enters the case 108 through the lower opening 109 and reaches the camera 107, there is a risk that it may adversely affect the accuracy of observing the flocs 106.

The objective of the present invention is to provide a floating matter observation device that can observe floating matter in a liquid under observation while eliminating the effects of external light.

In order to achieve the above object, the first invention is a floating matter observation device for observing floating matters in an observation target liquid, comprising:
The apparatus includes a light source that irradiates observation light from above the liquid surface onto floating objects below the liquid surface, an imaging device that images the floating objects irradiated with the observation light from above the liquid surface within an imaging range below the liquid surface, and a wave breaker that surrounds the imaging range and blocks waves on the liquid surface,
The imaging range is formed inside the wave breaker,
The wave breaker has an inlet opening upstream in the flow direction of the liquid to be observed and an outlet opening downstream in the flow direction of the liquid to be observed,
The inlet is submerged below the liquid surface.
The outlet is formed at a height that allows the liquid level to pass through.

With this, the liquid to be observed, containing suspended matter, flows into the inside of the wave breaker through the inlet and flows out of the wave breaker through the outlet. During this process, waves on the liquid surface are blocked by the wave breaker, suppressing the generation of waves around the imaging range. This allows the imaging device to capture suspended matter without the influence of waves. This allows for clear images of suspended matter to be obtained.

In addition, even if scum floating on the liquid surface flows into the inside of the wave breaker from the inlet along with the liquid being observed, the outlet is formed at a height that allows the liquid level to pass through, so the scum is easily discharged from inside the wave breaker through the outlet to the outside of the wave breaker. This prevents scum from accumulating inside the wave breaker.

In addition, because the imaging range is formed inside the wave-breaking member, even if external light (light other than observation light) enters the liquid surface outside the wave-breaking member and is reflected by floating objects in the liquid being observed, the reflected external light (reflected light) is blocked by the wave-breaking member below the liquid surface and does not reach the imaging device. This makes it possible to observe floating objects in the liquid being observed while eliminating the effects of external light.

In the floating object observation device of the second invention, the wave breaker has a tapered portion that tapers toward the lower end,
A lower outlet that opens below the liquid surface is formed at the lower end of the tapered portion.

As a result, if floating matter that flows into the inside of the wave breaker from the inlet along with the liquid being observed settles, the settled floating matter is discharged from the inside of the wave breaker through the lower outlet to the outside of the wave breaker. This prevents floating matter from settling and becoming trapped inside the wave breaker.

In the floating object observation device of the third invention, the lower outlet is located outside the field of view of the imaging device.

This prevents reflected light entering the inside of the wave breaker from the lower outlet (i.e., external light reflected by suspended matter in the liquid being observed) from appearing in the image obtained by capturing an image of suspended matter with the imaging device.

The floating object observation device of the fourth invention has a light-blocking member attached to the lower end of the wave breaker to suppress light entering the inside of the wave breaker from the outside of the wave breaker through the lower outlet.

As a result, light reflected by floating objects in the observation liquid outside the wave-breaking member (reflected light) is blocked by the light-shielding member, significantly reducing the amount of reflected light entering the inside of the wave-breaking member from the lower outlet. This prevents reflected light from appearing in images obtained by capturing floating objects with an imaging device.

In the floating object observation device of the fifth invention, a wave attenuation member is provided above the inlet, facing the inlet in the flow direction of the observation target liquid,
the wave-damping member is inclined so that a downstream end in the flow direction of the observation target liquid faces obliquely upward relative to an upstream end,
The lower part of the wave damping member is submerged below the liquid surface.

As a result, when the liquid to be observed flows into the inside of the wave breaker from the inlet, waves traveling in the direction of the liquid to be observed are attenuated by hitting the wave-damping member from the outside of the wave breaker. This makes the waves inside the wave breaker smaller than those on the outside, allowing floating objects to be imaged with the imaging device while eliminating the influence of waves.

In addition, because the wave-damping member is inclined, vortices are less likely to occur behind the wave-damping member (downstream in the flow direction). This prevents scum floating on the liquid surface from being caught in the vortex and remaining behind the wave-damping member.

In the floating object observation device according to the sixth aspect of the present invention, the light source and the imaging device are housed in a case member,
The wave breaker is provided at the bottom of the case member.

This means that external light is blocked by the case member, preventing external light from entering the imaging device.

In the floating object observation device of the seventh invention, the observation light is a sheet laser light that spreads laterally.

As described above, this invention makes it possible to observe suspended matter in the liquid being observed while eliminating the effects of external light.

1 is a cross-sectional view of a main part of a floating object observation device according to a first embodiment of the present invention. FIG. FIG. 2 is a front view of the wave breaker member of the floating object observation device. 4 is a view taken along the line XX in FIG. 3. 4 is a cross-sectional view taken along the line YY in FIG. 3. 4 is a view taken along the arrows ZZ in FIG. 3. This is a cross-sectional view of the wave breaker of the floating object observation device, showing how waves are attenuated by the wave attenuation plate and how raw water flows within the wave breaker. FIG. 10 is a front view of a wave breaker member of a floating object observation device according to a second embodiment of the present invention. 9 is a cross-sectional view taken along the line XX in FIG. 8. FIG. 1 is a cross-sectional view of a conventional floating object observation device.

Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
In the first embodiment, as shown in FIGS. 1 and 2 , raw water 10 (an example of a liquid to be observed) is stored in a flocculation pond of a water purification plant or the like, and a large number of flocs 11 (an example of suspended matter) are generated in the raw water 10.

A floating matter observation device 12 is installed in the flocculation pond to observe flocs 11 in the raw water 10. The floating matter observation device 12 is installed outdoors floating on the water surface 14 (an example of a liquid surface), and includes a light source 16 that irradiates the flocs 11 below the water surface 14 with sheet laser light 15 (an example of observation light), a camera 18 (an example of an imaging device) that images the flocs 11 irradiated with the sheet laser light 15 from above the water surface 14 within an imaging range 17 below the water surface, a case 19 that houses the light source 16 and camera 18, and a floating body 20 (float) that provides buoyancy.

The sheet laser light 15 spreads out in a fan shape laterally (e.g., in the flow direction 30 of the raw water 10) from the light source 16 in a plan view as shown by the imaginary line in Figure 6, and is approximately linear in a side view as shown by the solid line in Figure 1. The point where the sheet laser light 15 enters the water surface 14 obliquely downward from above is referred to as the water surface incident point 22. Furthermore, the point where the laser reflected light 24 (an example of reflected light) that is reflected by the sheet laser light 15 on the flocs 11 and enters the lens 23 of the camera 18 passes obliquely upward from below is referred to as the water surface passing point 25.

The imaging range 17 is the range in which the camera 18 captures an image of the flock 11 irradiated with the sheet laser light 15, and the focus of the camera 18 is adjusted to the imaging range 17. The imaging range 17 is set near the water surface 14.

The case 19 has a case member 27 exposed above the water surface 14 and a wave breaker member 28 attached to the bottom of the case member 27. The wave breaker member 28 surrounds the imaging range 17, the water surface incident point 22, and the water surface passing point 25 to block waves on the water surface 14. The imaging range 17, the water surface incident point 22, and the water surface passing point 25 are formed inside the wave breaker member 28.

In the flocculation basin, raw water 10 flows in one direction. As shown in Figures 3 to 6, the wave breaker 28 has a front plate 32 located upstream in the flow direction 30 (front-to-rear direction) of the raw water 10, a rear plate 33 located downstream in the flow direction 30, a pair of left and right side plates 34, 35, wave damping plates 36 (an example of a wave damping member) facing each other in the flow direction 30 of the raw water 10, an inlet 37 opening upstream in the flow direction 30, and an outlet 38 opening downstream in the flow direction 30.

As shown in Figure 3, the front panel 32 and the rear panel 33 are each formed in an inverted triangular shape when viewed from the front. Also, as shown in Figure 4, the side panels 34 and 35 are each formed in a trapezoidal shape when viewed from the side.

As shown in Figure 3, the wave attenuation plate 36 is trapezoidal in front view and is provided above the front plate 32. As shown in Figure 5, the downstream end in the flow direction 30 (the upper end of the wave attenuation plate 36) is inclined so that it faces diagonally upward relative to the upstream end (the lower end of the wave attenuation plate 36). The lower end of the wave attenuation plate 36 is submerged below the water surface 14, while the upper end of the wave attenuation plate 36 protrudes upward from the water surface 14. The upper end of the wave attenuation plate 36 is inclined downstream at a predetermined inclination angle A that is greater than 0° and less than 90° relative to the horizontal plane.

The inlet 37 is formed between the front plate 32 and the wave attenuation plate 36 and is submerged below the water surface 14. The outlet 38 is formed above the rear plate 33 at a height that is equal to the water surface 14. The upper end of the rear plate 33 is submerged below the water surface 14.

As shown in Figure 5, the front plate 32 and the rear plate 33 are inclined so that the horizontal distance B decreases toward the bottom. Similarly, as shown in Figures 1 and 3, one side plate 34 and the other side plate 35 are inclined in a V-shape so that the horizontal distance C decreases toward the bottom. As a result, the wave breaker 28 is a box-shaped member with an open top and a tapered portion 40 that tapers toward the bottom.

A lower outlet 41 is formed at the lower end of the tapered section 40, opening below the water surface 14. The lower outlet 41 is formed as an elongated slit in the flow direction 30 (front-to-back direction) of the raw water 10, opens to the inside and lower outside of the wave breaker member 28, and is located outside the field of view of the camera 18.

As shown in Figures 1, 3, and 4, a light-shielding plate 35a (an example of a light-shielding member) is provided at the lower end of the wave-breaking member 28. The light-shielding plate 35a prevents external light 54 reflected by flocs 11, etc. in the raw water 10 from entering the inside of the wave-breaking member 28 through the lower discharge port 41 from the outside of the wave-breaking member 28, and is formed by extending the other side plate 35 below the lower discharge port 41.

As described above, the light-shielding plate 35a is formed by extending the other side plate 35 to below the lower discharge port 41, but it may also be formed by extending one side plate 34 to below the lower discharge port 41. Alternatively, a light-shielding plate may be provided at the lower end of the wave-breaking member 28, separate from the side plates 34, 35.

Flange portions 42 are provided at the upper ends of both side plates 34, 35.

As shown in Figures 1 and 2, the light source 16 and camera 18 are housed in a case member 27. The case member 27 is a box-shaped member with an open bottom and a flange portion 43 at its bottom end. The ceiling of the case member 27 is formed with an upwardly protruding ridge portion 50 and a downwardly recessed valley portion 51.

The case member 27 is provided with transparent window panes 48, 49 and heaters (not shown) that prevent these window panes 48, 49 from fogging up. The sheet laser light 15 passes through the window pane 48 from the light source 16 and strikes the water surface 14, and the reflected laser light 24 reflected from the sheet laser light 15 passes through the window pane 49 and reaches the lens 23 of the camera 18.

The wave breaker member 28 is attached to the lower end of the case member 27 via flanges 42 and 43. The flanges 42 and 43 are joined together with connecting members (not shown) such as bolts and nuts, and by removing the connecting members, the case 19 can be separated into the case member 27 and the wave breaker member 28, top and bottom.

The operation of the above configuration is explained below.

As shown in Figure 5, raw water 10 containing flocs 11 flows into the inside of the wave breaker 28 through the inlet 37, flows inside the wave breaker 28 in the flow direction 30, and flows out of the wave breaker 28 through the outlet 38.

In this state, as shown in Figure 1, sheet laser light 15 is emitted from light source 16, and flocs 11 within imaging range 17 are imaged by camera 18. At this time, waves on the water surface 14 are blocked by wave breaker 28, suppressing the generation of waves at water surface incidence point 22, water surface passage point 25, and around imaging range 17, allowing flocs 11 to be imaged by camera 18 with the influence of waves eliminated. This allows a clear image of flocs 11 to be obtained.

In addition, even if scum floating on the water surface 14 flows into the inside of the wave breaker 28 from the inlet 37 along with the raw water 10, as shown in Figure 5, the outlet 38 is formed at a height that allows the water surface 14 to pass through, so the scum is easily discharged from inside the wave breaker 28 through the outlet 38 to the outside of the wave breaker 28. This prevents scum from accumulating inside the wave breaker 28.

Furthermore, as shown in FIG. 1, the imaging range 17 is formed inside the wave breaker 28. Therefore, even if external light 53 (light other than the observation light emitted from the light source 16, such as sunlight) enters the water surface 14 from outside the wave breaker 28 and is reflected by flocs 11 in the raw water 10, the reflected external light 54 (reflected light 54) is blocked by the wave breaker 28 below the water surface 14 and does not reach the lens 23 of the camera 18. This makes it possible to observe flocs 11 in the raw water 10 while eliminating the effects of external light 53, 54.

Furthermore, if flocs 11 that flow into the inside of the wave breaker 28 from the inlet 37 together with the raw water 10 settle, the settled flocs 11 are discharged from inside the wave breaker 28 through the lower outlet 41 and below the wave breaker 28. This prevents the flocs 11 from settling and remaining inside the wave breaker 28.

Also, as shown in Figure 7, when raw water 10 flows into the inside of the wave breaker 28 from the inlet 37 while waves 29 are generated on the water surface 14, the waves 29 are attenuated by hitting the wave attenuation plate 36 from the upstream side of the wave breaker 28 as they travel in the flow direction 30. As a result, the waves 55 inside the wave breaker 28 are significantly smaller than the waves 29 outside, and the flocs 11 can be imaged by the camera 18 without the influence of the waves 29.

In addition, because the upper end of the wave attenuation plate 36 is inclined downstream, vortices are less likely to occur behind the wave attenuation plate 36 (downstream in the flow direction 30), and as shown by the arrow in Figure 7, the raw water 10 flows smoothly behind the wave attenuation plate 36 toward the outlet 38. This prevents scum floating on the water surface 14 from being caught in the vortex and remaining behind the wave attenuation plate 36.

In addition, because the lower discharge outlet 41 is located outside the field of view of the camera 18, it is possible to prevent reflected light 54 incident on the inside of the wave breaker member 28 from the lower discharge outlet 41 (i.e., external light 54 reflected by flocs 11, etc. in the raw water 10) from appearing in the image obtained by capturing the flocs 11 with the camera 18.

In addition, as shown in Figure 1, external light 54 (reflected light 54) reflected by flocs 11 and the like in the raw water 10 is blocked by the light blocking plate 35a, which significantly reduces the amount of reflected light 54 entering the inside of the wave breaker member 28 from the lower discharge outlet 41. This further prevents reflected light 54 from appearing in the image of the flocs 11 captured by the camera 18.

In addition, as shown in Figure 1, external light 53, such as sunlight, is blocked by the case member 27, preventing the external light 53 from entering the lens 23 of the camera 18.

In this way, the flocs 11 in the raw water 10 can be observed without the influence of external light 53, making it possible to perform highly accurate observations even with raw water 10 that is highly transparent (such as purified water).

In addition, since the ceiling of the case member 27 has peaks 50 and valleys 51, rain can easily flow down from the ceiling of the case member 27.

In the first embodiment described above, as shown in Figure 7, the wave attenuation plate 36 attenuates waves 29 outside the wave breaker member 28. However, the front plate 32 may be extended upward above the water surface 14, and an inlet 37 may be formed in the front plate 32. In this case, the extended front plate 32 can attenuate waves 29 outside the wave breaker member 28. In this case, the wave attenuation plate 36 is located downstream (behind) the extended front plate 32, and only needs to prevent the generation of vortexes near the inlet 37. For this reason, the upper end of the wave attenuation plate 36 may be submerged below the water surface 14.

Second Embodiment
In the first embodiment described above, as shown in Figures 3 and 5, the wave breaker 28 has a front plate 32, and both side plates 34, 35 are inclined in a V shape, but in the second embodiment described below, as shown in Figures 8 and 9, the wave breaker 28 does not have a front plate 32, and further, one of the side plates 34 is disposed vertically without inclination, while only the other side plate 35 is inclined. The inlet 37 is formed between the lower end of the wave attenuation plate 36 and the lower outlet 41.

This provides the same effects and advantages as the first embodiment.

In each of the above embodiments, as shown in Figures 1 and 2, the floatable object observation device 12 has a float 20 and is installed floating on the water surface 14, but this is not limited to such a floating floatable object observation device 12; it may also be a fixed floatable object observation device 12 that does not have a float 20 and is fixed to the flocculation pond.

In each of the above embodiments, as shown in Figure 5, a flat plate is used as the wave attenuation plate 36, but this is not limited to a flat plate; an arc-shaped curved plate or a bent plate in a dogleg shape may also be used.

In each of the above embodiments, the floating matter observation device 12 is installed in a flocculation basin, but it may also be installed in a location other than a flocculation basin, such as a sedimentation basin. Furthermore, while flocs 11, an example of floating matter, are observed by the floating matter observation device 12, particles other than flocs 11 may also be observed.

In the above embodiments, sheet laser light 15 was used as an example of observation light, but it is not limited to sheet laser light 15, and laser light, visible light, etc. may also be used.

In each of the above embodiments, as shown in Figure 6, the incident direction of the sheet laser light 15 and the imaging direction of the camera 18 are perpendicular to the flow direction 30 of the raw water 10, and as shown in Figures 5 and 9, the longitudinal direction of the lower discharge outlet 41 is arranged parallel to the flow direction 30 of the raw water 10, but this arrangement is not limited to these.

10. Raw water (liquid to be observed)
11 Floc (floating matter)
12 Floating object observation device 14 Water surface (liquid surface)
15 Sheet laser light (observation light)
16 Light source 17 Imaging range 18 Camera (imaging device)
27 Case member 28 Wave breaker member 29 Wave 30 Flow direction 35a Light blocking plate (light blocking member)
36 Wave attenuation plate (wave attenuation member)
37 Inlet 38 Outlet 40 Tapered portion 41 Lower outlet 54 Reflected external light

Claims (7)

A floating matter observation device for observing floating matters in an observation target liquid,
The apparatus includes a light source that irradiates observation light from above the liquid surface onto floating objects below the liquid surface, an imaging device that images the floating objects irradiated with the observation light from above the liquid surface within an imaging range below the liquid surface, and a wave breaker that surrounds the imaging range and blocks waves on the liquid surface,
The imaging range is formed inside the wave breaker,
The wave breaker has an inlet opening upstream in the flow direction of the liquid to be observed and an outlet opening downstream in the flow direction of the liquid to be observed,
The inlet is submerged below the liquid surface.
A floating matter observation device characterized in that the outlet is formed at a height that allows the liquid surface to pass through. The wave breaker has a tapered portion that tapers toward the lower end,
2. The floating matter observation device according to claim 1, wherein a lower outlet opening below the liquid surface is formed at the lower end of the tapered portion. A floating object observation device as described in claim 2, characterized in that the lower outlet is located outside the field of view of the imaging device. A floating object observation device as described in claim 2, characterized in that a light-blocking member is provided at the lower end of the wave breaker to suppress light entering the inside of the wave breaker from the outside of the wave breaker through the lower outlet. a wave attenuation member is provided above the inlet, facing the direction of flow of the liquid to be observed;
the wave-damping member is inclined so that a downstream end in the flow direction of the observation target liquid faces obliquely upward relative to an upstream end,
2. The floating object observation device according to claim 1, wherein a lower portion of the wave damping member is submerged below the liquid surface. The light source and the imaging device are housed in a case member,
2. A floating object observation device according to claim 1, wherein the wave breaker is provided at the bottom of the case member. A floating object observation device as described in any one of claims 1 to 6, characterized in that the observation light is sheet laser light that spreads laterally.