JP2002250692A - Instrument and method for measuring oil concentration in oily water containing contaminant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve constitution of a measuring cell and an oil concentration detecting part for enhancing effect for reducing errors. SOLUTION: A photoreceptive element 3 is provided along the direction of light emitted from a light source 2, the direction is set to zero degree as viewed from the center of the cell, and photoreceptive elements 4, 5 are provided at two different angles in a space zone of 0-90 deg. around an axis thereof. A level of scattered light of oil is captured mainly, based on an output from the photoreceptive element in a 0 deg. side out of the two angles, a level of reflected light of a contaminant is captured based mainly on the output from the photoreceptive element in a 90 deg. side out of the two angles, a level of transmitted light reduced by scattering caused by the oil and the contaminant is captured, based mainly on an output from a transmission light photoreceptive element set at the 0 deg. position, and computing is conducted to remove the influence of the concentration of the contaminant using a mutual relation between the outputs, so as to measure the oil concentration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring cell having a high effect of reducing the influence of the concentration of a contaminant, which is a measurement error, in an oil concentration measurement of oil water containing a contaminant, an oil concentration measuring device using the same, and It concerns the measurement method.

[0002]

2. Description of the Related Art A conventional oil concentration measuring device and method for reducing the influence of the concentration of a contaminant are disclosed in Japanese Patent Application Laid-Open Publication No. H11-157,197, which describes an output from a transmitted light element that receives transmitted light reduced by an oil and a contaminant, and an oil amount. The output from the scattered light receiving element mounted near the transmitted light receiving element for the purpose of capturing and the reflected light output from the light receiving element mounted near the light source for the purpose of capturing the amount of contaminants other than oil are captured. Detects and derives only the oil concentration from the relationship between the output values using an equation.

[0003]

SUMMARY OF THE INVENTION The causes of errors caused by the measurement of the oil concentration, which cannot be avoided by the conventional measuring method, are affected by the concentration of the contaminants. It is an object of the present invention to provide an oil concentration measurement device and a measurement method capable of improving the effect of reducing an error by improving.

[0004]

In order to achieve the above object, a light receiving element is provided in the direction of light emitted from a light source, the direction of which is set to 0 degree when viewed from the center of the measurement cell, and 0 degree around the axis. The light receiving elements are installed at two different angles in a space range of up to 90 degrees. Of these angles, the amount of scattered light of oil is mainly captured from the output from the light receiving element on the 0 degree side, and the amount of reflected light of the contaminant is mainly captured from the output from the light receiving element on the 90 degree side. The amount of transmitted light reduced by the scattering of oil and contaminants is captured from the output of the transmitted light receiving element installed at the position of, and the influence of the concentration of contaminants is removed by using the correlation between these outputs. And calculate the oil concentration.

[0005]

Embodiments of the present invention will be described with reference to FIGS. 1A and 1B, FIG. 2, and FIGS. 3A and 3B. Example In FIG. 1A, a light emitting element was attached as a light source 2 to the side of a cylindrical measuring cell 1 for putting a sample water of a mixed solution of oil and impurities to be measured, and light emitted from the light source was An A light receiving element 3 that captures the attenuation of the amount of light as transmitted light when passing through is attached to the side surface opposite to the light source 2, the direction of the transmitted light passing through the center point of the measurement cell 1 is set to 0 °, and the oil content of the sample water is mainly A light receiving element 4 for capturing the light physically refracted / reflected and scattered is attached to a side surface in a direction perpendicular to the central axis of the measurement cell in a direction of 20 degrees, and a light receiving element C in the same plane. Attach to the side in the direction of 50 degrees. As an alternative position of the B light receiving element and the C light receiving element, one or both of them can be mounted in directions of -20 degrees and -50 degrees. These two
The two light receiving elements do not necessarily have to be on the same plane as the A light receiving element, and may be at an angle position of 20 degrees and 50 degrees that can effectively receive scattered light in all planes including the optical axis.
The above configuration is used as the measuring cell and the oil concentration detector 6 in FIG. 2, and the outputs of the three light receiving elements A, B, and C and, if necessary, temperature, pressure, and other auxiliary information Z are given to the signal processor / arithmetic unit 7. After the arithmetic processing is performed to remove the influence of the concentration of the contaminant, the value of the oil concentration is displayed or output.

In FIG. 3A showing another embodiment, a light source 9 is attached to a side surface of a measurement cell 8 for measuring an oil concentration, and light emitted from the light source 9 passes near the center of the measurement cell 8 as transmitted light. A concentrator 10 and A for receiving
The light receiving element 11 is mounted on the side opposite to the light source 9, and the direction of the A light receiving element 11 is defined as 0 degree when viewed from the center of the measurement cell, and within a space of ± 90 degrees from 0 degree in the traveling direction of the transmitted light. The B light collector 13 and the B light receiving element 14, which can receive a large amount of scattered light mainly due to refraction and reflection from oil, are connected to the A light collector 11
And a C light collector 16 and a C light receiving element 17 capable of receiving a large amount of scattered light mainly due to reflection from contaminants are mounted in a position behind the B light collector 13. The above configuration corresponds to the six measurement cells and the oil concentration detector of FIG. Output of A light receiving element 11 and B light receiving element 1
4 and the output of the C light receiving element 17 and, if necessary, the temperature and other auxiliary information to the signal processing / arithmetic unit 7,
After performing arithmetic processing to remove the influence of the concentration of the contaminant, the value of the oil concentration is displayed or output. In this configuration of the oil concentration detecting unit, unnecessary scattered light can be removed by attaching the B shield plate 12 and the C shield plate 15 to the light receiving surfaces of the B light collector and the C light collector. Each condensing / light receiving element
A lens and a light receiving element can be used, and a circular or elliptical mirror and a lens optical system can be combined and the optical axis can be changed in different directions to detect the space effectively.
In addition, a light receiving element such as a CCD capable of receiving light in a plane can be combined into a small and flat structure. FIG. 3B shows a light receiving range captured by each light collector in a form projected on the light receiving surface of the C light collector with the light source as the center. A
The condenser 10 receives transmitted light in the range of, for example, 0 to 10 degrees, the B condenser 13 receives scattered light in the range of, for example, 10 to 20 degrees, and the C condenser 17 receives, for example, 20 degrees. From 30
Receives reflected light in the range of degrees

[0007]

Since the present invention is configured as described above, it has the following effects.

[0008] A small amount of oil in water forms a spherical oil vesicle, and light from a light source partially refracts and partially refracts when passing through the interior of the oil vesicle due to a difference in refractive index with water. reflect. These lights are refracted and reflected by many other oil vesicles and are scattered in a complicated manner, but most of the scattered light travels in a limited range around 0 degrees in FIG. A1. On the other hand, the light from the light source cannot pass through the suspended solids, which are the main contaminants in the oil water, and is reflected on the surface, and is reflected on many other suspended solids and scattered in multiple directions according to the shape of the surface of the solid. Its direction of travel is spread over a wider angular range than that of the oil.

The configuration of the oil concentration detector used in the conventional measuring method is such that the light receiving elements are separated as much as possible in order to separate the detection of scattered light mainly due to refraction by oil and scattered light mainly reflected by contaminants. It is mounted at an angle of 180 ° opposite to the angular position, ie the center of the measuring cell. Therefore, at the angular position of the light receiving element for the contaminant, the amount of received light is small and the sample water becomes turbid as the concentration increases, and the amount of reflected light is further attenuated. Further, since the output of the light-receiving element for transmitted light and the output of the light-scattering light receiving element for oil also include a large amount of output of scattered light due to contaminants, the oil concentration and the contaminant concentration cannot be separated by themselves. If correction and separation are performed based on the concentration information of the contaminant with a small amount of received light, the measurement error of the oil concentration increases.

In the present invention, as shown in the embodiment, by using two light receiving elements having different light receiving angles and placing the B light receiving element at a position where more reflected / scattered light from the contaminant can be received, turbidity is obtained. In this case, the influence of the attenuation of the reflected light can be reduced. Since the output of the B light receiving element is sufficiently large as compared with the light receiving position of the conventional method, separation by calculation is possible. Further, the effect can be improved by an extremely easy method without increasing the number of light receiving elements and without impairing economic efficiency.

Further, in the present invention, as shown in another embodiment, a light collector is attached to a light receiving element to receive light in a wide range, and the area of the shielding plate is changed by the shielding plate with the light emitting direction of the light source 9 as a central axis. Thus, the scattered light 1 and the scattered light 2 can be separated and received by sorting the light receiving range angularly. Thus, the optical signal of the scattered light can be received without excess compared with the method shown in FIGS. 1A and 1B, and the influence of the attenuation of the reflected light can be further reduced.

[Brief description of the drawings]

FIG. 1A is a top view of a detection unit according to an embodiment in which a light receiving element is arranged in a plane including an optical axis.

FIG. 1B is a side view of a detection unit of an embodiment in which a light receiving element is arranged in a plane including an optical axis.

FIG. 2 is a configuration block diagram of an oil concentration measurement device.

FIG. 3A is a side view of a configuration example in a case where a light receiving range is separated by a disc-shaped light collector;

FIG. 3B is a projection view onto a C-collector light-receiving surface in a configuration example in which a light-receiving range is separated by a disk-type light collector

Claims (3)

[Claims] 1. A light source 2 is attached to a side surface of a measuring cell 1 in which oil water for measuring an oil concentration is put, and light emitted from the light source 2 passes near the center of the measuring cell 1 on a side surface opposite to the light source 2. A light receiving element 3 for receiving the straight light as transmitted light is attached, its angular position as viewed from the center is 0 degree, and refraction mainly from oil within a range of 0 to ± 90 degrees in the traveling direction of the transmitted light. A light-receiving output of the B light-receiving element 4 mounted at an angle position capable of receiving a large amount of scattered light due to reflection;
A signal for performing arithmetic processing based on the correlation between these values using the light receiving output of the C light receiving element 5 mounted at an angular position capable of receiving a large amount of scattered light mainly reflected by the contaminant and the light receiving output of the A light receiving element 3. An oil concentration measuring device and a measuring method for measuring and displaying or outputting an oil concentration which is less affected by the concentration of a contaminant by the processing / operation unit 7. 2. A light source 9 is attached to a side surface of a measuring cell 8 containing an oily water for measuring an oil concentration, and the light emitted from the light source 9 receives the light passing near the center of the measuring cell 8 as transmitted light. The condenser 10 and the A light receiving element 11 are
The direction of the A light receiving element 11 is determined to be 0 degree when viewed from the center of the measurement cell, and the refraction from oil is mainly performed within a space of ± 90 degrees from 0 degree in the traveling direction of the transmitted light. B collector 13 and B that can receive much scattered light due to reflection
The light receiving element 14 is mounted at a position behind the A light collector 11, and the C light collector 16 and the C light receiving element 17, which can receive a large amount of scattered light mainly due to reflection from the contaminant, are placed behind the B light collector 13. And mixed by the signal processing / arithmetic unit 7 which performs arithmetic processing based on the correlation between these values using the output of the A light receiving element 11, the output of the B light receiving element 14, and the output of the C light receiving element 17. An oil concentration measurement device and method for measuring and displaying or outputting an oil concentration that is less affected by the concentration of a substance. 3. An oil concentration measuring device and a measuring method according to claim 2, wherein a B-shielding plate 12 and a C-shielding plate 15 are additionally mounted on the light-receiving surface of the B light collector 13 and the light-receiving surface of the C light collector 16, respectively. .