JP2007205742A - Oil detecting method and liquid surface cover for oil detection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil detecting method which certainly detects oil in its early stages by using an oil detector for detecting the oil when the thickness of the oil becomes a definite value or above. <P>SOLUTION: The oil detector 3 for detecting the oil P is floated in an oil and water separation tank 2 when the thickness of the oil P in the oil and water separation tank 2 becomes a definite value (detected thickness value) or above, and the cover piece 11 of a liquid surface cover 1 for oil detection is floated in the oil and water separation tank 2 to cover a part of a water surface so as to reduce the water surface on which the oil P is floated. Even if the oil P flowing in the oil and water separation tank 2 is small, the thickness of the oil P on the water surface becomes the detected thickness value or above, and the oil P is certainly detected in its early stages by the oil detector 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil detection method for detecting oil leaked into a liquid tank such as an oil / water separation tank and a liquid level cover for oil detection.

  For example, since the inside of a hydroelectric power plant is an environment where a very small amount of oil exists, a very small amount of oil is always collected by an oil-water separation tank. On the other hand, oil such as working oil or lubricating oil from equipment may leak into the oil / water separation tank. Oil leakage from equipment is monitored, and equipment equipment malfunctions or is damaged, or oil spills off the premises. It is necessary to prevent such. In addition, as an apparatus or device for detecting oil leakage, there is an apparatus utilizing light water surface reflection by a laser or the like, but such an apparatus also detects a very small amount of oil. Therefore, it cannot be determined whether the detected oil is due to leakage from the equipment or a trace amount of oil present in the power plant.

For this reason, the oil detector which detects oil when it floats in an oil-water separation tank and the thickness of the oil on an oil-water separation tank becomes more than fixed (detection thickness) is used (for example, refer patent document 1). . In this oil detector, for example, three electrodes are attached to a sealed floater (floating body), and the electrostatic capacity of the electrode portion is detected by a high frequency generated from a detection circuit. And when oil flows in on a water surface, since an electrode contacts with water through oil, an electrostatic capacitance will change a lot. This change is detected and amplified by a detection circuit, and a contact signal is output by a converter.
JP 2004-184192 A

  By the way, in the oil detector as described in the said patent document 1, oil is not detected unless the thickness of the oil on an oil-water separation tank becomes more than fixed (for example, 3-5 mm or more). That is, when the surface area (area of the water surface) of the oil / water separation tank is large, the oil is not detected unless a large amount of oil flows into the oil / water separation tank. For this reason, when detecting the oil on an oil-water separation tank with a large surface area with such an oil detector, it is recommended to use a partition plate (oil separator). That is, the area around the oil detector floating in the oil / water separation tank is partitioned by a partition plate whose plate surface is arranged in the depth direction, and the oil / water flows into the frame partitioned by the partition plate, The thickness is made to reach the detected thickness quickly.

  However, the detection method using such a partition plate is based on the premise that oil and water flows into the frame partitioned by the partition plate. For this reason, not only the inflow path of the oil water is limited, but the oil cannot be detected when the oil water cannot flow into the frame partitioned by the partition plate. Furthermore, for example, when a large amount of oil water flows into the frame partitioned by the partition plate and the inflowed oil flows out of the frame from the lower end of the partition plate, such oil is not detected. .

  Therefore, an object of the present invention is to provide an oil detection method that can detect oil early and reliably using an oil detector that detects oil when the thickness of the oil exceeds a certain value.

In order to achieve the above object, the invention according to claim 1 is an oil detection method using an oil detector that detects oil when the oil is floated in the liquid tank and the thickness of the oil on the liquid tank exceeds a certain value. A liquid level cover covering a part of the liquid level in the liquid tank is floated in the liquid tank, the liquid level where the oil floats is reduced, and the oil is detected by the oil detector. It is a feature.
(Function)
The liquid level where the oil floats is reduced by the liquid level cover, and the oil floating on the reduced liquid level is detected by the oil detector.

According to a second aspect of the present invention, in the oil detection method according to the first aspect, the liquid level cover is floated so that the oil floats on the liquid level around the oil detector.
(Function)
Oil floats on the liquid level around the oil detector by the liquid level cover, and this floating oil is detected by the oil detector.

Invention of Claim 3 is a liquid level cover for oil detection used with the oil detector which floats in a liquid tank and detects the oil when the thickness of the oil on the said liquid tank becomes more than fixed. The liquid tank floats in the liquid tank and covers a part of the liquid level in the liquid tank so as to reduce the liquid level on which the oil floats.
(Function)
When the main oil detection liquid level cover is floated in the liquid tank, a part of the liquid level in the liquid tank is covered by the main oil detection liquid level cover, and the liquid level where the oil floats is reduced.

According to a fourth aspect of the invention, in the oil detection liquid level cover according to the third aspect of the invention, the oil-repellent property of repelling oil on the surface is provided.
(Function)
When the main oil detection liquid level cover is floated in the liquid tank, the oil attached to the surface of the main oil detection liquid level cover is repelled and floats on the liquid level.

According to a fifth aspect of the present invention, in the oil detection liquid level cover according to the third or fourth aspect, the upper surface is formed so that oil attached to the upper surface flows toward the oil detector. It is a feature.
(Function)
When the main oil detection liquid level cover is floated in the liquid tank, the oil on the upper surface of the main oil detection liquid level cover flows toward the oil detector.

The invention described in claim 6 is characterized in that the oil detection liquid level cover according to any one of claims 3 to 5 is composed of a plurality of cover pieces having the same shape.
(Function)
Depending on the size and shape of the liquid level in the liquid tank, or the position of the oil detector, if a plurality of cover pieces are floated in the liquid tank, a part of the liquid level in the liquid tank is covered by the cover pieces. As a result, the liquid level where the oil floats is reduced.

  According to the first aspect of the present invention, since the liquid level where the oil floats is reduced by the liquid level cover, even if the amount of oil flowing into the liquid tank is small, the thickness of the oil on the liquid level becomes a certain level or more. . That is, oil can be detected early. Further, the oil water inflow path is not limited, and the oil detector detects the oil floating on the liquid surface no matter where and how the oil water flows into the liquid tank. That is, oil can be detected reliably. In addition, by changing the size of the liquid level cover and changing the size of the liquid level where the oil floats, it is possible to adjust the amount of inflow to detect the oil by the oil detector.

  According to invention of Claim 2, since oil floats on the liquid level around an oil detector by a liquid level cover, the oil which flowed into the liquid tank is detected earlier and reliably by an oil detector.

  According to the invention described in claim 3, by floating the liquid level cover for oil detection in the liquid tank, the liquid level where the oil floats is reduced, so even if the amount of oil flowing into the liquid tank is small, The thickness of the oil on the liquid level becomes more than a certain level. That is, oil can be detected early. In addition, by changing the shape and position of the liquid level cover for oil detection according to the size and shape of the liquid level in the liquid tank, or the position of the oil detector, the oil water can flow from where and how. Even if it flows in, oil floating on the liquid surface can be detected by the oil detector. That is, oil can be detected reliably. In addition, by changing the size of the oil detection liquid level cover, it is possible to adjust the amount of oil that is detected by the oil detector.

  According to the invention described in claim 4, since the oil attached to the surface of the liquid level cover for oil detection is repelled and floats on the liquid level, the oil that has flowed into the liquid tank is reliably detected by the oil detector. be able to.

  According to the fifth aspect of the present invention, since the oil attached to the upper surface of the oil detection liquid level cover flows toward the oil detector, the liquid is detected via the upper surface from above the liquid level cover for oil detection. Oil that has flowed into the tank can also be reliably detected by the oil detector.

  According to the invention described in claim 6, the liquid level is reduced by floating a plurality of cover pieces in the liquid tank in accordance with the size and shape of the liquid level in the liquid tank or the arrangement position of the oil detector. The oil flowing into the liquid tank can be detected early and reliably. In addition, it is possible to appropriately reduce the liquid level where oil floats by changing the number of cover pieces without preparing multiple oil detection liquid level covers for multiple liquid tanks of different shapes and sizes. it can. That is, one type of oil level detection liquid level cover can be applied to a plurality of types of liquid tanks.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

(Embodiment 1)
FIG. 1 is a perspective view showing a state in which oil P is detected using an oil detection liquid level cover 1 (liquid level cover) according to Embodiment 1 of the present invention. Reference numeral 2 in the figure denotes an oil / water separation tank (liquid tank) installed in the hydroelectric power plant. That is, equipment such as power generation facilities, pressure oil tanks and pressure oil pumps are installed on the upper floor, an oil collection tank is installed on the lower floor (underground layer), and an oil / water separation tank 2 is installed further below. An oil detector 3 is floated in the oil / water separation tank 2. The oil detector 3 is an oil detector that detects the oil P when the thickness of the oil P on the oil / water separation tank 2 (on the water surface) exceeds the detection thickness (constant), and is generally used widely. The detailed configuration is omitted here, but the configuration is generally as follows. That is, three electrodes are attached to a sealed floater (floating body), and the electrostatic capacity of the electrode portion is detected by the high frequency generated from the detection circuit. When the oil P flows onto the water surface (liquid surface) in the oil / water separation tank 2, the electrode comes into contact with the water W through the oil P, so that the capacitance changes greatly. This change is detected and amplified by a detection circuit, and a contact signal is output by a converter. Further, the thickness of the oil P required for the oil detector 3 to detect the oil P, that is, the detected thickness is 3 to 5 mm.

  The oil detection liquid level cover 1 is composed of a plurality of cover pieces 11, and all the cover pieces 11 are made of the same material and have the same shape (fixed shape). That is, the cover piece 11 is made of polyethylene, and therefore has oil repellency and water repellency that repels oil P and water W on the surface. Further, it is formed in a disk (disk) shape, and its outer diameter is substantially the same as the outer diameter of the oil detector 3. Furthermore, the thickness (weight) of the cover piece 11 is such that the cover piece 11 is above the water W in the oil / water separation tank 2 even when the oil P flows into the oil / water separation tank 2 and the oil P floats on the water surface. Is set to float.

  In order to detect the oil P flowing into the oil / water separation tank 2 using such an oil detection liquid level cover 1 and the oil detector 3, the following may be performed. That is, the oil detector 3 may be floated in the oil / water separation tank 2 and the plurality of cover pieces 11 may be floated in the oil / water separation tank 2 so as to cover the water surface of the oil / water separation tank 2. Thereby, the water surface in the oil / water separation tank 2 is covered by the cover piece 11 except for the gap between the cover pieces 11 and the gap between the cover piece 11 and the inner wall of the oil / water separation tank 2 (part of the water surface is covered). The water surface where oil P floats decreases. In this state, when oil P or water W flows into the oil / water separation tank 2, the oil P floats on the water surface such as a gap between the cover pieces 11. And even if the inflow amount of the oil P is small, since the water surface on which the oil P can float is reduced, the thickness of the oil P on the water surface becomes equal to or greater than the detected thickness. For this reason, even if the inflow amount of the oil P is small, the oil P is detected at an early stage by the oil detector 3. In contrast, when the oil detection liquid level cover 1 is not used, if the amount of inflow of the oil P is small, the oil P floats only on a part of the water surface, as shown in FIG. The thickness of the oil P on the water surface does not reach the detected thickness even if it floats on the entire surface. For this reason, when the inflow amount of the oil P is small, the oil detector 3 does not detect the oil P, and the oil P is not detected unless a large amount of the oil P flows into the oil-water separation tank 2. This is even more true when the surface area (water surface area) of the oil / water separation tank 2 is large.

  As described above, according to the oil detection liquid level cover 1 and the oil detection method according to the present embodiment, even if the amount of oil P flowing into the oil / water separation tank 2 is small, the oil P is detected at an early stage. be able to. Further, the inflow path of the oil P and the water W is not limited, and the oil P can be detected no matter where and how the oil P or the water W flows into the oil / water separation tank 2. That is, there is no restriction that the oil detector 3 must be partitioned around the oil detector 3 as in the prior art, and the oil P and water W must be allowed to flow only into the frame partitioned by the partition plate. And no matter how and how the oil P or water W flows into the oil / water separation tank 2, the oil P floats on the water surface such as the gap between the cover pieces 11. It can be detected reliably. Furthermore, since the surface of the cover piece 11 has oil repellency and the oil P attached to the surface of the cover piece 11 is repelled and floats on the water surface, the oil P flowing into the oil / water separation tank 2 is caused by the oil detector 3. It is detected more reliably.

  Further, by changing the number of cover pieces 11 floating in the oil / water separation tank 2, the inflow amount for detecting the oil P by the oil detector 3 can be adjusted. That is, by reducing the number of cover pieces 11, the decrease in the water surface where the oil P can float is reduced (a lot of water surface remains), and if the oil P does not flow into the oil / water separation tank 2, the oil detector 3 Oil P will not be detected. On the other hand, when the cover piece 11 is floated a lot, the water surface on which the oil P can float is greatly reduced, and the oil detector 3 detects the oil P even if a small amount of the oil P flows into the oil / water separation tank 2. .

  Furthermore, by changing the number and arrangement of the cover pieces 11 according to the size and shape of the surface area (water surface) of the oil / water separation tank 2 or the arrangement position of the oil detector 3, the oil P that has flowed into the oil / water separation tank 2 can be reduced. It can be detected early and reliably. That is, it can be applied flexibly according to the size of the oil / water separation tank 2 and the like. Moreover, the oil P floats by changing the number and arrangement of the cover pieces 11 without preparing multiple types of oil detection liquid level covers for the multiple types of oil / water separation tanks 2 having different shapes and sizes. Water surface can be reduced appropriately. That is, one type of oil level detection liquid level cover 1 can be applied to a plurality of types of oil / water separation tanks 2 and other liquid tanks.

(Embodiment 2)
FIG. 3 is a perspective view showing a state in which the oil P is detected using the oil detection liquid level cover 20 (liquid level cover) according to the second embodiment of the present invention. The oil detection liquid level cover 20 is made of an integral polyethylene and has a surface (plate surface) substantially the same as the surface (water surface) of the oil / water separation tank 2. In addition, one corner is cut out into a rectangle and a window 20a is formed. The window portion 20a is larger than the oil detector 3, and is set to a size that allows the oil detector 3 to detect the oil P floating on the water surface in the window portion 20a. Further, the upper surface of the oil detection liquid level cover 20 has a window portion so that when the oil P or water W is attached to the upper surface, the oil P or water W flows toward the window portion 20a, that is, the oil detector 3. It is formed in a downward slope toward 20a.

  In order to detect the oil P flowing into the oil / water separation tank 2 using such an oil detection liquid level cover 20 and the oil detector 3, the following may be performed. That is, the oil detection liquid level cover 20 may be floated so as to cover the water surface of the oil / water separation tank 2, and the oil detector 3 may be floated on the water surface in the window portion 20a. Thus, the water surface in the oil / water separation tank 2 is covered by the oil detection liquid surface cover 20 except in the window portion 20a, and the water surface on which the oil P can float is only the water surface in the window portion 20a. That is, the oil P floats only on the water surface around the oil detector 3. In this state, when the oil P flows into the oil / water separation tank 2, the oil P floats on the water surface in the window portion 20a, and the amount of inflow of the oil P is small as in the case of the first embodiment. Even if it exists, the oil P is detected early and reliably. In addition, since the upper surface of the oil detection liquid level cover 20 is inclined downward toward the window portion 20a, for example, oil P and water W from the upper side of the oil detection liquid level cover 20 are in the oil / water separation tank 2. Even if it flows into the oil, the oil P or water W attached to the upper surface of the oil detection liquid level cover 20 flows toward the window 20a, and the oil P is reliably detected by the oil detector 3.

  As described above, the first and second embodiments of the present invention have been described in detail. However, the specific configuration is not limited to these embodiments, and there are design changes and the like within the scope of the present invention. However, it is included in this invention. For example, in Embodiment 1, the cover piece 11 is disk-shaped, but the plate surface as shown in FIG. 4 is a rectangular cover piece 21, and the gap between the cover pieces 21 is reduced to reduce the oil detector 3. You may make it the oil P float more on the surrounding water surface. In Embodiments 1 and 2, the cover piece 11 of the oil detection liquid level cover 1 and the oil detection liquid level cover 20 are made of polyethylene. However, the surface is made of other materials such as foamed polystyrene. An oil-repellent and water-repellent coating may be applied.

It is a perspective view (partial cross section figure) which shows the state which detects oil using the liquid level cover for oil detection concerning Embodiment 1 of this invention. It is a perspective view (partial sectional view) showing a state where oil is detected without using the oil detection liquid level cover according to the first embodiment of the present invention. It is a perspective view (partial cross section figure) which shows the state which detects oil using the liquid level cover for oil detection concerning Embodiment 2 of this invention. It is a perspective view (partial cross section figure) which shows the use condition of the other cover piece of the oil level liquid level cover concerning Embodiment 1 of this invention.

Explanation of symbols

1, 20 Oil level cover for detecting oil (Liquid level cover)
11, 21 Cover piece 2 Oil-water separation tank (liquid tank)
3 Oil detector 20a Window P Oil W Water

Claims (6)

An oil detection method using an oil detector that floats in a liquid tank and detects oil when the thickness of the oil on the liquid tank exceeds a certain level,
A liquid level cover covering a part of the liquid level in the liquid tank is floated in the liquid tank, the liquid level where the oil floats is reduced, and the oil is detected by the oil detector.
An oil detection method characterized by that. Floating the liquid level cover so that the oil floats on the liquid level around the oil detector;
The oil detection method according to claim 2. A liquid level cover for oil detection that is floated in a liquid tank and used together with an oil detector that detects oil when the thickness of the oil on the liquid tank exceeds a certain level,
Floating in the liquid tank, formed so as to reduce the liquid level where the oil floats by covering a part of the liquid level in the liquid tank,
A liquid level cover for oil detection. Oil repellency that repels oil on the surface,
The liquid level cover for oil detection according to claim 3. The upper surface is formed such that oil attached to the upper surface flows toward the oil detector,
The oil level cover for oil detection according to claim 3 or 4. Consists of multiple cover pieces of the same shape,
The liquid level cover for oil detection according to claim 3, wherein the liquid level cover is for oil detection.

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