Light-transmitting glass plate liquid level meter observation device

Abstract

The invention discloses a light-transmitting glass plate liquid level meter observation device which is characterized in that a condensation imaging amplification device is additionally arranged on the basis of an existing glass plate structure, and the condensation imaging amplification device mainly comprises a linear Fresnel lens large plate, a linear Fresnel lens small plate, a shading plate, a mirror reflection plate and a connecting device. The linear Fresnel lens large plate, the linear Fresnel lens small plate and the observation hole are sequentially arranged on one side of the glass plate measurement cavity in a vertical center line alignment manner; the observation hole, the linear Fresnel lens small plate and the linear Fresnel lens large plate are sequentially arranged on the other side of the glass plate measurement cavity in a vertical center line alignment manner; the outer sides of the large linear Fresnel lens plate and the small linear Fresnel lens plate are connected through the light shielding plate to form a relatively closed system, the requirement for the manufacturing precision of the linear Fresnel lens plate is not harsh, the required observation effect is achieved, the installation position of the lens is set according to calculation, installation is more accurate, and the observation effect is good.

Description

Technical Field

[0001] The invention belongs to the field of petroleum and chemical industry, and relates to a liquid level measurement technology, in particular to a light-transmitting glass plate liquid level gauge observation device. Background Art

[0002] On many devices, a glass plate level gauge is needed to display the real liquid level. The light-transmitting glass plate level gauge is the most commonly used one. When the measured medium is a transparent liquid and the light passes through the liquid column, the light is reflected, refracted and absorbed by the liquid. The light intensity passing through the liquid column in the inner cavity of the glass plate is weaker than the light intensity passing through the gas phase above the liquid column. The liquid level is distinguished by the difference in light intensity passing through the liquid column and the gas phase. When the distance is a little farther, or when it is cloudy or the light is dark at night, the light intensity difference is not large. The human eye is not sensitive to weak light, and it is difficult to judge the liquid level. When the light-transmitting glass plate level gauge is used for a long time, the inner wall of the glass plate is relatively dirty, the intensity of light transmission is weakened, and it is not easy to distinguish the liquid level. Sometimes it is even necessary to close the root valve in front of the glass plate level gauge to make the liquid column fluctuate significantly before the liquid level can be seen clearly, because the glass plate can reflect the liquid level most realistically, and the operator also trusts the direct visual observation results, so the light-transmitting glass plate is still the most widely used although the observation effect is sometimes not very good.

[0003] Improving the visual sensitivity of the light-transmitting glass plate level gauge is a common improvement method, especially for boundary position observation and extremely important liquid level measurement occasions such as boilers. It is adopted to add special additional lights to the back panel and force the background light intensity to increase (especially the boiler water level gauge), without relying on natural light and factory lighting. In this way, a light bulb needs to be installed on the back of the glass plate and the waterproof and explosion-proof shell of the lamp needs to be installed, which is also expensive. In addition, because 220V AC power needs to be introduced, the shell needs to be explosion-proof, and cables need to be pulled, which requires a lot of construction. The service life of explosion-proof lamps is also limited. Keeping the lights on 24 hours a day will increase the failure rate, increase energy consumption, and require frequent maintenance. The explosion-proof shell also has safety hazards.

[0004] In addition, when observing the translucent glass plate, you must stand in front of the glass plate facing the observation hole. Sometimes the installation position is not suitable, making observation very inconvenient. For example, the glass plate is installed in the air of a tower or equipment, and you can only climb a ladder to observe it. When pipes are densely installed near the observation hole, you need to turn sideways or squeeze into the pipe to observe facing the observation hole. Long-distance observation is also difficult to see clearly because the observation hole is very narrow.

[0005] The structure of the glass plate can be seen in the current standard HG 21589.2-95. The basic structure and measurement principle of the light-transmitting glass plate have remained basically unchanged for many years.

[0006] Patent CN202220362373.3 discloses an improved device for glass plate level gauge, which adds a small float in the glass plate to enhance the observation effect, but it still cannot solve the problem that the small float is not easy to be observed in dim light. Especially when measuring the interface position, only a translucent glass plate can be used, and the small float is of no help in measuring the interface position.

[0007] Patent CN201120390426.4 discloses a two-color glass plate level gauge, which uses color difference to improve the observation effect, such as a two-color glass plate level gauge, but it also cannot solve the problem of unsatisfactory color difference in the upper and lower parts of the observed liquid column when the light is dim. Summary of the invention

[0008] In order to solve the technical problem in the prior art that it is difficult to see the liquid level clearly in a light-transmitting glass plate liquid level gauge and an external light source needs to be used to increase the light intensity, the present invention provides an observation device for a light-transmitting glass plate liquid level gauge.

[0009] A light-transmitting glass plate liquid level gauge observation device provided by the present invention is a focusing imaging magnifying device added on the basis of an existing glass plate structure, wherein the focusing imaging magnifying device mainly comprises a large linear Fresnel lens plate, a small linear Fresnel lens plate, a shading plate, a mirror reflection plate and a connecting device, wherein the large linear Fresnel lens plate, the small linear Fresnel lens plate and the observation hole are arranged in sequence on one side of a glass plate measurement cavity in a manner of aligning a vertical center line, and the observation hole, the small linear Fresnel lens plate and the large linear Fresnel lens plate are arranged in sequence on the other side of the glass plate measurement cavity in a manner of aligning a vertical center line; the focal spots of the large linear Fresnel lens plate and the small linear Fresnel lens plate overlap, the outer sides of the large linear Fresnel lens plate and the small linear Fresnel lens plate are connected by a shading plate to form a relatively closed system to avoid stray light from entering and to prevent dust at the same time, and the mirror reflection plate is connected to the outer side of the large linear Fresnel lens plate by a hinge at a certain angle.

[0010] There is no fixed connection angle requirement between the shading plate and the large linear Fresnel lens plate and the small linear Fresnel lens plate. When the large linear Fresnel lens plate and the small linear Fresnel lens plate are positioned according to the overlap of the focal spots, the shading plate is connected to the outer edges of the large linear Fresnel lens plate and the small linear Fresnel lens plate.

[0011] The length of the large linear Fresnel lens plate and the small linear Fresnel lens plate in the linear direction is the same and is greater than or equal to the length of the observation hole, and is consistent with the length of the glass plate.

[0012] The widths of the large linear Fresnel lens plate and the small linear Fresnel lens plate are related to the focal spot position. The closer the focal spot is to the lens plate, the smaller the outward installation space of the observation device.

[0013] The linear Fresnel lens plate is installed as close to the observation hole as possible and faces the observation hole and the measurement cavity.

[0014] The mirror reflection plate is connected to the linear Fresnel lens plate through a hinge. After adjusting the angle, the mirror reflection plate can be fixed by a fixing device, which is a clip or a similar supporting fixing member.

[0015] The flat sides of the large linear Fresnel lens plate and the small linear Fresnel lens plate face outwards for easy cleaning and maintenance. The toothed prism side of the large linear Fresnel lens plate is protected by a light-weight shading plate, which can effectively avoid dust pollution and other stray light interference and enhance the observation effect.

[0016] The mirror reflection plate is connected to the outer side of the linear Fresnel lens plate through a hinge, and the included angle between the mirror reflection plate and the linear Fresnel lens plate is 30° to 60°.

[0017] The shading plate is made of a lightweight thin aluminum alloy plate, and the linear Fresnel lens plate is made of PMMA, also known as acrylic or organic glass.

[0018] The shading plate is bonded to the outer surface of the observation hole and fixed to the glass plate by wire binding. A sealed space can be formed between the shading plate and the large linear Fresnel lens plate, the small linear Fresnel lens plate and the glass plate by gluing. The two Fresnel plates are firmly fixed to the edge of the shading plate and form a seal relative to each other to prevent dust from entering.

[0019] The width of the large linear Fresnel lens plate is 3 to 8 times, preferably 5 times, the width of the small linear Fresnel lens plate.

[0020] The reflective plate is selected from a thin glass mirror or a light PVC plate coated with a reflective coating. When strong reflection of the introduced light is required, a glass mirror is preferred.

[0021] The working principle of the light-transmitting glass plate liquid level gauge observation device provided by the present invention is:

[0022] Select a location with a stable and strong light source background light on one side, such as a light-colored background, a bright background under the sun, or a street lamp, etc. Adjust the mirror radiation plate on one side to reflect its light into the large linear Fresnel lens plate on one side, and design the focal spot of the small linear Fresnel lens plate on this side to overlap with the large lens plate on this side. The light will pass through the large linear Fresnel lens plate and then converge at the focal spot and continue to enter the small linear Fresnel lens plate through the focal spot. According to the optical principle of convex lenses, the light after passing through the small linear Fresnel lens plate will pass through the observation hole and the light-transmitting glass plate measurement cavity in parallel. The optical path of the light is very concentrated, and it will not be absorbed or lost by the outer wall of the glass plate measurement cavity, and will be emitted from the observation hole on the other side to the small linear Fresnel lens plate on the other side. The small linear Fresnel lens plate and the linear Fresnel lens The large plate is arranged symmetrically with the small linear Fresnel lens plate and the large linear Fresnel lens plate on the opposite side through the central axis of the cross section of the glass plate. According to the reversible principle of the optical path, the light passing through the large linear Fresnel lens plate on the other side will be emitted in parallel to the mirror reflection plate on the other side. The angle of the plate is adjusted to align with the high-probability observation position, so that the observer can observe the bright liquid column without facing the glass plate. According to the principle of the existing Fresnel lens, that is, the linear Fresnel lens plate is on a plane perpendicular to the lens plate and in the width direction of the surface, and the optical path characteristics parallel to the plane are similar to the focusing effect of a convex lens. The width of the liquid column is magnified in the horizontal imaging direction, and the vertical imaging maintains the original size, so that the liquid level is not distorted, thereby enhancing the observation effect of the light-transmitting glass plate.

[0023] The present invention has the following beneficial effects:

[0024] 1) The present invention can use natural light during the day and factory lighting at night. The angle of the mirror reflector can be adjusted at any time to collect light. The main body does not need an external explosion-proof light source. It is an intrinsically safe design and is more energy-saving and environmentally friendly.

[0025] 2) Fresnel lens plate has a strong focusing characteristic, so the intensity of ambient light is not high. The light intensity is related to the width of the lens plate. The focal length can also be made very small according to requirements. Because it is a plate-type structure and light weight, it is easy to fix and does not take up much space outside the installation.

[0026] 3) PMMA is the mainstream material for Fresnel lenses. It has the characteristics of high transparency, light weight, and low cost. It has optical properties very close to those of glass and is easy to manufacture according to specific sizes.

[0027] 4) The flat side of the linear Fresnel lens plate faces outward for easy cleaning and maintenance. The toothed prism side of the large lens can be protected by a light-weight sunshade, which can effectively avoid dust pollution and other stray light interference and enhance the observation effect.

[0028] 5) The present invention does not have strict requirements on the manufacturing accuracy of the linear Fresnel lens plate, and the material is easy to obtain from the market. The required observation effect is to arrange the installation position of the lens according to calculation. The more accurate the installation, the better the observation effect.

[0029] 6) The auxiliary facility of this device, the mirror reflection plate, can realize observation at any position and flexible selection of background light source at any position.

[0030] 7) Based on the principle of linear Fresnel lens plate, the lens group of this device can realize horizontal magnification imaging, a wider liquid column can be observed at a long distance, observation is easier, and the vertical liquid level imaging is not distorted.

[0031] 8) The present invention has a wide range of applications. Since it does not contact the medium, there is no need to consider the medium's corrosion, temperature, pressure and other working conditions, and it has no impact on the safety of existing glass plates.

[0032] 9) There is no need to replace the existing glass plate. You can modify and install it on the existing glass plate by yourself without changing the structure of the original glass plate. It requires little investment and is easy to modify. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a principle diagram of the optical path of light after it passes through two linear Fresnel lenses in the present invention;

[0034] Figure 2 A top view of the present invention;

[0035] Figure 3 It is a side sectional view of the present invention;

[0036] Figure 4 This is the overall effect diagram after adding a reflector plate to the present invention.

[0037] In the figure: 1- linear Fresnel lens large plate, 2- focal spot, 3- linear Fresnel lens small plate, 4- focusing light behind the linear Fresnel lens large plate, 5- parallel light behind the linear Fresnel lens small plate, 6- shading plate, 7- mirror reflection plate, 8- background light source position, 9- human eye observation position, 10- hinge, 11- observation hole, 12- glass plate, 13- glass plate measurement cavity, 14- liquid column. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings.

[0039] like Figures 1 to 4 The present invention provides a light-transmitting glass plate level gauge observation device, the structure of which includes a large linear Fresnel lens plate 1, a small linear Fresnel lens plate 3, a shading plate 6, a mirror reflection plate 7, and a hinge 10.

[0040] The structures of the large linear Fresnel lens plate 1 and the small linear Fresnel lens plate 3 are detailed in the Mechanical Industry Standard of the People's Republic of China JB / T 13804-2020 "Linear Focusing Fresnel Lens", which can be simply described as an acrylic plate with a smooth surface on one side and a long linear microstructure array on the other side. The microstructure of each array is serrated, and the shape of each sawtooth is different. Each array has a different refraction effect on light. However, after calculation and processing of the sawtooth shape of each array, each array refracts the light and focuses it into one point along the tangent direction perpendicular to the lens plate. The final effect is that the refracted light of all arrays is projected on a straight line parallel to the lens plate, which is called a focal spot.

[0041] According to the principle of Fresnel lens plate and Figure 1 , light enters from the smooth surface of the linear Fresnel lens large plate 1, and then converges on the focal spot 2. After passing through the focal spot 2, the light begins to diverge again. The focal spot of the linear Fresnel lens large plate 1 overlaps with the focal spot of the linear Fresnel lens small plate 3. After passing through the focal spot, the light is projected on the serrated surface of the linear Fresnel lens small plate 3. The two plates are arranged in parallel with their center lines facing each other. The linear Fresnel lens small plate 3 also has a convergence effect on the light. According to the reversible principle of the optical path, the light projected on the linear Fresnel lens small plate 3 after passing through the focal spot 2 will be emitted in parallel after passing through the plate. The width of the linear Fresnel lens small plate is designed. It is arranged with the same width as the observation hole and facing the observation hole 11. Because the light projected on the linear Fresnel lens large plate 1 is not projected to the surface of other components to be absorbed or lost, it is transmitted from the linear Fresnel lens small plate 3, passes through the glass plate measuring cavity 13, and is restored and emitted on the opposite side. The optical path of the light is changed. Except that the glass plate body and the liquid column in the glass plate measuring cavity 13 have loss and absorption of the light, resulting in a light intensity difference between it and the upper gas phase, the light intensity is retained to the greatest extent without loss. However, due to the focusing principle of the linear Fresnel lens, the light intensity passing through the observation hole 11 is greatly enhanced from the source.

[0042] The width of the linear Fresnel lens small plate 3 is the same as the width of the modified observation hole 11, which is generally 20 to 30 MM. The width of the designed linear Fresnel lens large plate 1 is 3 to 8 times the width of the linear Fresnel lens small plate 3. Combined with the size of the on-site installation space, it is recommended to be 5 times, and the width is about 100 to 150 MM. The final converged light intensity is achieved to make the liquid level observation effect clear. If the light intensity effect is not enough, the width of the linear Fresnel lens large plate 1 can be further increased. The focal length of the linear Fresnel lens large plate 1 and the linear Fresnel lens small plate 3 is made as small as possible according to the products on the market, so that the space requirement for the external modification of the glass plate is small and the modification is easier.

[0043] After the width of the linear Fresnel lens large plate 1 and the linear Fresnel lens small plate 3 is determined, the length is cut to a size greater than the height of the observation hole and consistent with the height of the glass plate. Figure 2 and Figure 3 During installation and fixation, the side and top and bottom surfaces are shielded and fixed with shading plates 6. The shading plates 6 are made of lightweight thin aluminum alloy plates. The aluminum alloy plates have a certain strength and are not easy to deform. They are also light and easy to bond to the outer surface of the observation hole and then fixed to the glass plate by wire binding. The shading plates and the large and small linear Fresnel lens plates and the glass plate can be sealed by gluing. The large and small linear Fresnel lens plates are fixed to the edge of the shading plates and sealed relative to each other to prevent dust from entering. The two plates must face the observation hole, such as Figure 2 The centers of the large linear Fresnel lens plates and the small linear Fresnel lens plates on both sides of the glass plate are arranged in a straight line with the central axis of the cross section of the glass plate. After the above design, the light intensity passing through the glass plate liquid level meter can be increased several times, and the enhancement multiple is approximately the width of the large linear Fresnel lens plate 1 divided by the width of the small linear Fresnel lens plate 3 minus the absorption and loss of light passing through the two plates. The shading plate 6 can shield external stray light, so that the background imaging is only the observation hole, and the imaging around the observation hole is a dark background, which is easier to increase the observation sensitivity. The liquid column 14 and the upper gas phase space are brighter than the dark background, which increases the visual sensitivity and makes observation easier.

[0044] When the human eye observes the liquid level from the front of the linear Fresnel lens large plate 1, because the principle of the Fresnel lens is the same as that of the convex lens, the focal length of the linear Fresnel lens large plate is greater than the focal length of the linear Fresnel lens small plate. According to common sense in geometry, the linear Fresnel lens small plate 3 is located between one and two focal lengths of the linear Fresnel lens large plate 1. According to the imaging law of the convex lens, the image we see is a real image of the liquid column 14 that is opposite to the left and right in the horizontal direction and horizontally enlarged. There is no change in the vertical direction and the liquid level is not distorted. The liquid level 14 is the same in the horizontal direction. Imaging in the opposite direction has no effect on the measurement of the liquid level and does not affect the observation, but the magnified imaging is of great significance for long-distance observation. The imaging of mirror reflection is a virtual image, so the final observation effect is that compared with the original observation imaging before the transformation, the image seen by the human eye at the observation position 9 after the transformation is a brighter and thicker liquid column than the background light source position 8 before the transformation. The increase in light intensity makes it easier to distinguish the liquid level. The thickened imaging makes it easier to observe and distinguish the liquid surface at a long distance, and the observation effect in the vertical direction remains unchanged, which does not affect the accurate judgment of the real liquid level.

[0045] The surface of the linear Fresnel lens plate 1 that contacts the external environment is a smooth surface. When covered with dust, the smooth surface can be easily scrubbed or self-cleaned by rainwater.

[0046] When observing the glass plate, you need to face the Fresnel lens plate 1. When the human eye observation position 9 of the glass plate is unreasonable due to the opening position of the equipment, the observation angle is not conducive to daily inspection, or the background light source position 8 opposite the glass plate observation port is not strong enough, you need to adjust the light introduction direction or observation angle, such as Figure 4 A hinge 10 is installed on the shading plate 6 outside the linear Fresnel lens large plate 1, and the hinge 10 is also connected to the mirror reflector 7. The reflector 7 can be flexibly selected from a thin glass mirror or a lightweight PVC board coated with a reflective coating. In principle, it is light in weight, easy to clean, and has clear imaging. When it is necessary to introduce strong light reflection, a glass mirror is recommended. The angle between the mirror reflector 7 and the linear Fresnel lens plate 1 is appropriately adjusted, generally 30° to 60°, and the position 8 of the stable background light source with the highest light intensity is found. For example, a nearby lighting source can be selected for night observation, and a pure light-colored background with strong sunlight can be selected for daytime observation. The mirror reflector 7 on the light-introducing side is fixed with a clip so that the light is stably reflected and horizontally incident on the linear Fresnel lens plate 1 with the strongest light. The mirror reflector 7 is fixedly installed on the opposite observation port through the hinge 10 fixed on the shading plate. The imaging is adjusted to the angle that is most convenient for observation in daily operation and fixed with a clip. The mirror reflector 7 on the observation side is fixed, so that the background light source or the observation angle can be flexibly adjusted. The double-sided hinges can be on one side relative to the shading plates on each side, or on the opposite side, so that the observation direction is on the same side or on the opposite side as the background light source. It can be flexibly designed according to the actual position of the glass plate on site.

[0047] When no adjustment is needed, the mirror reflection plate 7 is rotated away from the front area of ​​the linear Fresnel lens large plate 1, or removed from the hinge 10, and the mirror reflection plate 7 is not used, and the large plate can be directly observed.

Claims

1. A light-transmitting glass plate liquid level gauge observation device, characterized in that: The invention relates to a focusing imaging magnifying device added on the basis of an existing glass plate structure, wherein the focusing imaging magnifying device comprises a large linear Fresnel lens plate, a small linear Fresnel lens plate, a shading plate, a mirror reflection plate and a connecting device. The large linear Fresnel lens plate, the small linear Fresnel lens plate and the observation hole are arranged in sequence on one side of a glass plate measurement cavity in a manner of aligning the vertical center line, and the observation hole, the small linear Fresnel lens plate and the large linear Fresnel lens plate are arranged in sequence on the other side of the glass plate measurement cavity in a manner of aligning the vertical center line; the focal spots of the large linear Fresnel lens plate and the small linear Fresnel lens plate overlap, the outer sides of the large linear Fresnel lens plate and the small linear Fresnel lens plate are connected through the shading plate to form a relatively closed system, and the mirror reflection plate is connected to the outer side of the large linear Fresnel lens plate through a hinge at a certain angle.

2. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: After the large linear Fresnel lens plate and the small linear Fresnel lens plate are positioned so as to overlap the focal spots, the shading plate is connected to the outer edges of the large linear Fresnel lens plate and the small linear Fresnel lens plate.

3. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The linear Fresnel lens large plate and the linear Fresnel lens small plate have the same length in the linear direction and are greater than or equal to the length of the observation hole, which is consistent with the length of the glass plate; when the linear Fresnel lens small plate is installed, it is as close to the observation hole as possible and faces the observation hole and the measurement cavity.

4. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The width of the large linear Fresnel lens plate is 2 to 8 times the width of the small linear Fresnel lens plate.

5. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The width of the large linear Fresnel lens plate is 5 times the width of the small linear Fresnel lens plate.

6. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The connecting device is a hinge, the mirror reflection plate is connected to the outer side of the linear Fresnel lens plate through a hinge, the angle between the mirror reflection plate and the linear Fresnel lens plate is 30° to 60°, and the mirror reflection plate is fixed by a fixing device, which is a clip.

7. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The plane sides of the large linear Fresnel lens plate and the small linear Fresnel lens plate face outwards, and the toothed prism side of the large linear Fresnel lens plate is protected by a shading plate.

8. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The material of the shading plate is a lightweight thin aluminum alloy plate, and the material of the large linear Fresnel lens plate and the small linear Fresnel lens plate is PMMA.

9. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The shading plate is bonded to the outer surface of the glass plate observation hole and fixed to the glass plate by wire binding. A sealed space is formed between the shading plate, the large linear Fresnel lens plate, the small linear Fresnel lens plate and the glass plate by gluing. The large linear Fresnel plate and the small linear Fresnel plate are fixed to the edge of the shading plate to form a seal relative to each other.

10. The light-transmitting glass plate liquid level gauge observation device according to claim 1, characterized in that: The reflective plate is selected from a thin glass mirror or a light PVC plate coated with a reflective coating.

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