JP2003035646A - Method for maintaining oil odor detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for maintaining an oil odor detector exhibiting excellent maintainability in which contamination of piping can be reduced by judging oil odor detection based on response of oil odor (intensity of oil odor) quickly with high reliability and performing cleaning of the piping and fixing/ removal of an oil odor sensor without delay. SOLUTION: The oil odor detector comprises a crystal unit sensor for detecting oil odor contained in a fluid being measured, and piping for feeding the fluid being measured wherein cleaning of the piping and the crystal unit sensor is started at a stage where the detected intensity of oil odor reaches a specified second detection level L2 not lower than a specified first detection level L1 for determining detection of oil odor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil odor detection device, and for example, maintenance of the oil odor detection device is performed in a water intake plant such as a water purification plant to attach / detach the oil odor detection device at appropriate timing to reduce contamination of piping. It is about the method.

[0002]

2. Description of the Related Art When river water containing hydrocarbon-based oil flows into a water purification plant, a large amount of activated carbon must be added to remove the oil. No oil is determined from the presence or absence of an oil odor by an oil odor detection device, and when an oil odor is detected, an alarm is immediately issued and water intake is stopped. For example, Japanese Patent Laid-Open No. 11-295
In Japanese Patent Laid-Open No. 203, a method for managing the presence or absence of an oily odor using a crystal oscillator sensor is proposed for river water flowing into a water purification plant.

The crystal oscillator sensor has the ability to selectively detect the oily odor emitted from hydrocarbon oils such as light oil, kerosene, and heavy oil. Therefore, this crystal oscillator sensor can detect only oily odors from various odors even when river water emits various odors other than oily odors, and thus it is possible to detect mixing of hydrocarbon-based oil into river waters. it can.

FIG. 7 is a schematic configuration diagram showing the configuration of a general oily odor detecting device, showing the cleaning and desorption processing states.
The sample water taken as the fluid to be measured is sent to the purging device 2 through the electromagnetic three-way valve 1 and the pipe, and the oil component contained in the sample water is vaporized. The vaporized gas to be measured is sent through a pipe to a crystal oscillator sensor 3 which is an oil odor detection sensor, and the presence or absence of oil odor is determined. The temperature control device 4 controls the temperature of the gas to be measured and the temperature of the crystal oscillator sensor 3 to a constant temperature in order to remove the influence of the temperature drift of the crystal oscillator sensor 3 and increase the accuracy. Reference numeral 5 is an electromagnetic three-way valve.

When the oily odor component is adsorbed, the crystal oscillator sensor 3
The resonance frequency change of is reduced. This change in resonance frequency is detected and output as the odor intensity of oily odor. FIG. 8 is a graph showing a typical example of the response of the oil odor detected by the crystal oscillator sensor 3 in the oil odor detection device of FIG. 7 and the temporal change of the odor intensity. The vertical axis represents the odor intensity detected by the crystal oscillator sensor, the horizontal axis represents the elapsed time, and g represents the odor intensity curve.
A is the time when the oil component is mixed into the sample water (in other words, the oil odor is generated in the gas to be measured), and B is the time when the oil component is sufficiently removed from the sample water and the oil odor disappears. Show. The above odor intensity is detected by the crystal oscillator sensor that selectively detects only the oily odor, and therefore becomes the oily odor intensity.

The presence or absence of oily odor and the detection of oily odor are performed based on the response of the oily odor and the temporal change of the odor intensity of the oily odor. That is,
The detection of oil odor and the absence of oil odor are judged based on the time characteristics of the rise of the oil odor signal and the time characteristics of the fall of the oil odor signal. Further, as is apparent from FIG. 8, even if the change (increase) at the time point A is slow, it is possible to recognize the start time point of the change with care, but the change (decrease) after the time point B is It is slower than the change (increase) from A, and it becomes extremely difficult to determine the deodorizing point.

[0007] Conventionally, when it is determined that the deodorization (the oily odor has disappeared), the electromagnetic three-way valve 1 is switched to cleaning water in Fig. 7, the piping is cleaned, and the electromagnetic three-way valve 5 is switched. It is common to send cleaning air to 3 to clean the sensor, that is, to desorb the adsorbed gas. Therefore, when the determination of deodorization is delayed, there are problems that the piping becomes dirty and it takes time to attach and detach, and maintenance is troublesome. Further, there is a risk that the dirt in the pipe may reduce the reliability of the sensor 3 for detecting the oil odor.

[0008]

In the detection of the presence or absence of oily odor by the crystal oscillator membrane sensor, it is relatively easy to determine the oily odor detection as is clear from FIG. It is extremely difficult to make a detection judgment, and wash when it is judged to be deodorant,
In the conventional maintenance method of starting desorption, when the determination of no oily odor is delayed, there is a problem that the piping becomes dirty and it takes time before desorption, and maintenance is troublesome.

The present invention has been made in order to solve the above-mentioned problems, and quickly and reliably determines the oil odor detection, and cleans and removes the piping and / or the oil odor detection sensor without delay. It is an object of the present invention to provide a maintenance method for an oil odor detection device, which can reduce contamination of the piping and / or the oil odor detection sensor and can be easily maintained.

[0010]

A first method of the maintenance method of an oil odor detecting device of the present invention is an oil odor detecting sensor for detecting an oil odor contained in a fluid to be measured, and the above fluid to be measured. And a pipe for feeding, and when the detected oil odor intensity reaches a predetermined detection level that can be confirmed as oil odor detection,
The cleaning of the piping and / or the oil odor detection sensor is started.

A second method of the maintenance method of an oil odor detecting device of the present invention is an oil odor detecting sensor for detecting an oil odor contained in a fluid to be measured, and a pipe for feeding the fluid to be measured to the oil odor detecting sensor. And the cleaning of the pipe and / or the oil odor detection sensor is started when the detected oil odor intensity reaches a predetermined second detection level exceeding a predetermined first detection level for determining oil odor detection. It was done like this.

A third method of the maintenance method of the oil odor detecting device of the present invention is an oil odor detecting sensor for detecting an oil odor contained in a fluid to be measured, and a pipe for feeding the fluid to be measured to the oil odor detecting sensor. When the detected oil odor intensity is equal to or higher than a predetermined detection level for determining the oil odor detection and the oil odor intensity continues for a predetermined time or more, the cleaning of the pipe and / or the oil odor detection sensor is started. It was done.

A fourth method of the maintenance method of the oil odor detecting device of the present invention is the crystal oscillator sensor according to any one of the first to third methods, wherein the oil odor detecting sensor is a quartz oscillator sensor coated with a sensitive film. .

A fifth method of the maintenance method of the oil odor detecting device of the present invention is a first oil odor detecting sensor capable of selectively detecting an oil odor contained in a fluid to be measured but having a slow response.
A second oil odor detection sensor that has a quick response but low selectivity, and a pipe that supplies the fluid to be measured to the second oil odor detection sensor are provided.
After the oil odor detection sensor detects the oil odor, when the second oil odor detection sensor detects the absence of the oil odor, the cleaning of the pipe and / or the oil odor detection sensor is started. .

A sixth method of maintenance of the oil odor detecting device of the present invention is the method of the fifth method, wherein when the detection output of the first oil odor detecting sensor continues at a predetermined level or higher for a predetermined time or longer, the oil odor is detected. And so on.

A seventh method of the maintenance method of the oil odor detecting device of the present invention is the method of the fifth method, wherein the detection output of the first oil odor detecting sensor is not less than a predetermined level and the second oil odor detecting is When the detection output of the sensor is higher than a predetermined level, the oil odor is detected.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 relates to a maintenance method for an oil odor detection device according to a first embodiment of the present invention, and shows a response of an oil odor detected by a crystal oscillator sensor 3 which is an oil odor detection sensor and a temporal change of the oil odor intensity. It is a graph. The vertical axis represents the oil odor intensity detected by the crystal oscillator sensor, the horizontal axis represents the elapsed time, g ₁ represents the oil odor intensity curve when the first embodiment is applied, g ₀ represents the pipe and the crystal oscillator sensor 3. It is an oil odor intensity curve in the case where washing, that is, desorption treatment is not performed. L ₁ is the first detection level, L ₂ is the second detection level, K is the oil odor detection stage, and D is the desorption process start stage. The crystal oscillator sensor 3 has, for example, a structure in which an organic polymer thin film for adsorbing gas is formed on the surface of the crystal oscillator, and changes in the resonance frequency of the crystal oscillator due to changes in mass due to adsorption of gas. What selectively detects the oily odor from (ΔF) is used.

Next, the operation will be described. The crystal oscillator sensor 3 of the oil odor detection device having the configuration shown in FIG. 7 as in the conventional example.
The presence or absence of oily odor is detected by. The sample water, which is the fluid to be measured, is sent to the purging device 2 through the electromagnetic three-way valve 1 and the pipe, and the purging device 2 vaporizes the oil component contained in the sample water, and the vaporized gas to be measured is odord through the pipe. It is sent to the crystal oscillator sensor 3 which is a detection sensor to determine the presence or absence of oily odor. The temperature control device 4 controls the temperature of the gas to be measured and the temperature of the crystal oscillator sensor 3 to a constant temperature, in this case 50 ° C., in order to remove the influence of the temperature drift of the crystal oscillator sensor 3 and improve the accuracy.

The presence or absence of oily odor is judged from the response of the oily odor and the temporal change of the rise of the oily odor odor intensity. In the first embodiment, the oily odor intensity detected as shown in FIG. The first detection level L ₁ to be determined and the second detection level L ₂ which is equal to or higher than the first detection level (in other words, the level at which the desorption process start confirmation level can be confirmed to be a proper oil odor without an error) are set. ing. Then, it is judged that the oil odor has been detected (there is an oil odor) when the first detection level is exceeded, and the detection of the oil odor is completed when the second detection level is exceeded, and the piping and / or the crystal oscillator sensor etc. The cleaning and desorption processes are started. The first and second detection levels can be empirically determined. For example, in this case, the first detection level is a detection level of 2 Ton (2-fold dilution) in odor intensity, and the second detection level is a detection level of 1 Ton (1-fold dilution) in odor intensity. The second detection level is about twice the first detection level. The detection level at which the detected oil odor intensity can be confirmed as an oil odor detection is (-) 40-
(−) 90 Hz (Max) and the frequency band is about 9 MHz.

For cleaning and desorption of the piping and the crystal oscillator sensor 3, etc., the electromagnetic three-way valve 1 is switched, and instead of the sample water, the cleaning water is sent to the purging device 2 through the piping,
This is performed by switching the electromagnetic three-way valve 5 and sending cleaning air to the crystal oscillator sensor 3. Cleaning of the sensor 3, that is, desorption of the adsorbed gas can be promptly performed by raising an appropriate temperature and controlling to an appropriate temperature and humidity.

In the first embodiment, at the stage of the first detection level for determining the oil odor detection, an alarm for the oil odor is issued to eliminate the odor.
The cleaning and desorption are started at the stage of the second detection level at which it can be confirmed that there is a considerable oil odor instead of an error at a stage earlier than it is determined that the oil odor has disappeared.
By performing cleaning and desorption at an earlier timing, it is possible to reduce contamination of the pipe, prolong the maintenance cycle, and detect oil odor with excellent maintainability. It is responsive and can reduce the detection time of oily odors and desorption time, and can improve the reliability by preventing deterioration of the reliability of the sensor due to dirt in the piping.

Embodiment 2. FIG. 2 is a graph showing changes in oil odor response and oil odor intensity over time detected by the crystal oscillator sensor 3 according to the maintenance method for the oil odor detection apparatus according to the second embodiment of the present invention. The vertical axis represents the oil odor intensity detected by the crystal oscillator sensor, the horizontal axis represents the elapsed time, g ₂ represents the oil odor intensity curve when the first embodiment is applied, g ₀ represents the piping and the crystal oscillator sensor 3. It is an oil odor intensity curve in the case where washing, that is, desorption treatment is not performed. L is an oil odor detection level, K is an oil odor detection stage, D is a desorption process start stage, and t is an oil odor detection level duration time from the oil odor detection stage K until the desorption process is started.

In the first embodiment, the first detection level for determining the oily odor detection and the second detection level for starting the desorption process are divided into levels, but in the second embodiment, FIG.
The time is measured by a timer at a stage K when the detected oil odor intensity reaches or exceeds a predetermined oil odor detection level that is judged to be an oil odor detection, and the oil odor intensity above the oil odor detection level is a predetermined time (t ) Above, for example, the oil odor detection is stopped at the stage D which is continued for several minutes, and the cleaning of the piping, the crystal oscillator sensor 3 and the like is started. When the oil odor intensity above the oil odor detection level continues for a predetermined number of minutes, it is confirmed that the oil odor is certainly present. The presence or absence of oil odor is detected by the crystal oscillator sensor 3 which is the oil odor detection sensor of the oil odor detection device having the configuration shown in FIG. ing.

In the second embodiment as well, as in the first embodiment, desorption is started before the stage where it is judged that the deodorant and oily odors have disappeared. The desorption time can be reduced, and the reliability of the sensor can be prevented from lowering due to contamination in the pipe, and the reliability can be improved. In addition, depending on the setting of the oil odor intensity duration time (t) equal to or higher than the oil odor detection level, it is possible to perform desorption at a timing earlier than that of the first embodiment, and there is an advantage that the contamination of the pipe can be reduced.

Embodiment 3. In the first and second embodiments described above, the maintenance method in the oil odor detection device using only the crystal vibration sensor 3 having high selectivity but slow response as the oil odor detection sensor has been described. Crystal oscillator sensor 3 which is a first oily odor detecting sensor capable of selectively detecting but has a slow response, and a semiconductor sensor 6 which is a second oily odor detecting sensor having a quick response but a low selectivity.
The case of using the two oily odor detection sensors will be described. FIG. 3 is a schematic configuration diagram showing a configuration of the oil odor detection device according to the third embodiment, and shows a cleaning / desorption process state. A semiconductor sensor 6 is provided in series with the crystal oscillator sensor 3 and downstream thereof. FIG. 4 is a graph showing an example of the response of odor in the fluid to be measured detected by the oil odor detection device shown in FIG. The vertical axis shows the odor intensity detected by the oil odor detection sensor, the horizontal axis shows the elapsed time, g ₃ is the odor intensity curve by the crystal oscillator sensor, g ₄ is the odor intensity curve by the semiconductor sensor, and each time axis is Match.

The semiconductor sensor 6 has a structure in which a metal oxide semiconductor such as a tin oxide material press-molded between a pair of white metal alloy wire coils is applied and sintered. A device that detects odor is used as a change in the thermal conductivity and a change in the electrical conductivity due to the adsorption of gas on the surface of the steel sheet as a change in the resistance value as seen from both ends of the white metal alloy wire coil.

In the present embodiment, the oil odor is generated at the stage A when the odor intensity detected by the crystal oscillator sensor 3 starts to increase, and after the oil odor is detected, the odor detected by the semiconductor sensor 6 is detected. It is determined that the oil odor has disappeared at stage B when the strength suddenly drops, and the piping, the crystal oscillator sensor 3,
The cleaning and desorption processing of the semiconductor type sensor 6 and the like are started. The oily odor detection and cleaning operations are the same as those in the above-described embodiment.

In the present embodiment, the oil odor is detected by the crystal oscillator sensor 3 having a high selectivity for the oil odor, but the judgment of no oil odor (deodorization) is extremely made at the time of deodorization. Since the semiconductor type sensor 6 having a quick response is used instead of the difficult quartz oscillator sensor 3 having a slow response, the deodorant can be easily determined and can be accurately performed without delay. The presence or absence of oily odor can be detected in real time, and cleaning and desorption processing of piping, oily odor detection sensor, etc. can be performed without delay. Therefore, the contamination of the pipe can be reduced, the maintenance can be easily performed, and the oily odor can be detected with high reliability.

Fourth Embodiment FIG. 5 is a schematic configuration diagram showing a configuration of an oil odor detection device according to Embodiment 4 of the present invention,
Shows the state of cleaning and desorption. In the third embodiment described above, the semiconductor sensor 6 is provided in series with the crystal oscillator sensor 3 and downstream thereof, but in the fourth embodiment, the semiconductor sensor 6 is not provided in series as shown in FIG. But
It is provided upstream of the crystal oscillator sensor 3 near the sample water introduction side. As a result, the absence of oily odor can be detected earlier than in the third embodiment, so that cleaning and desorption can be performed earlier.

Embodiment 5. FIG. 6 is a flow chart showing the oil odor detection determination method according to the fifth embodiment of the present invention. In the third and fourth embodiments, the crystal oscillator sensor 3 is used to detect the oily odor.
According to the fifth embodiment, as shown in FIG. 6, the oil odor detection output (odor intensity) of the crystal oscillator sensor 3 is equal to or higher than a predetermined level. Then, when the strength of a predetermined level or higher continues for a predetermined time or longer and the detection output of the semiconductor type sensor 6 is higher than or equal to the predetermined level, it is determined that the oil odor is detected. The reliability of the oil odor detection determination is improved. It should be noted that the determination of the absence of oily odor is made by the semiconductor sensor 6 as in the third and fourth embodiments, and the cleaning and desorption processes can be performed without delay, the contamination of the pipes can be reduced, and the maintenance can be easily performed.

[0031]

The first method of the maintenance method of the oil odor detecting device of the present invention is an oil odor detecting sensor for detecting the oil odor contained in the fluid to be measured, and the above fluid to be measured is fed to the sensor. When the detected oil odor intensity reaches a predetermined detection level at which oil odor detection can be confirmed, the pipe and / or
Alternatively, since the cleaning of the oil odor detection sensor is started, the cleaning and desorption processing are performed at an early timing, and the contamination of the pipe and / or the oil odor detection sensor can be reduced, and the pipe and / or the above It is possible to reduce deterioration in reliability of the oil odor detection sensor due to dirt on the oil odor detection sensor.

The second method of the maintenance method of the oil odor detecting device of the present invention is an oil odor detecting sensor for detecting the oil odor contained in the fluid to be measured, and a pipe for feeding the fluid to be measured to the oil odor detecting sensor. And the cleaning of the pipe and / or the oil odor detection sensor is started when the detected oil odor intensity reaches a predetermined second detection level exceeding a predetermined first detection level for determining oil odor detection. Since the cleaning and the desorption process are performed at an early timing, the contamination of the pipe and / or the oil odor detection sensor can be reduced, and the oil odor detection sensor due to the contamination of the pipe and / or the oil odor detection sensor can be reduced. It is possible to reduce the decrease in reliability.

A third method of the maintenance method for an oil odor detecting device of the present invention is an oil odor detecting sensor for detecting an oil odor contained in a fluid to be measured, and a pipe for feeding the fluid to be measured to the oil odor detecting sensor. When the detected oil odor intensity is equal to or higher than a predetermined detection level for determining the oil odor detection and the oil odor intensity continues for a predetermined time or more, the cleaning of the pipe and / or the oil odor detection sensor is started. Therefore, in addition to the above effects, the reliability of oil odor detection is increased.

A fourth method of the maintenance method of the oil odor detecting device of the present invention is the method of any one of the first to third methods, wherein a crystal oscillator sensor coated with a sensitive film is used as the oil odor detecting sensor. Since the oil odor can be selectively absorbed, the oil odor can be easily detected and the reliability of the detection can be improved.

A fifth method of the maintenance method of the oil odor detecting device of the present invention is a first oil odor detecting sensor capable of selectively detecting an oil odor contained in a fluid to be measured, but having a slow response.
A second oil odor detection sensor that has a quick response but low selectivity, and a pipe that supplies the fluid to be measured to the second oil odor detection sensor are provided.
After the oil odor detection sensor detects the oil odor, when the second oil odor detection sensor detects no oil odor, the cleaning of the pipe and / or the oil odor detection sensor is started. The odorless judgment can be easily performed without delay. In addition to the above effects, the reliability of detecting the presence or absence of oily odor is improved.

The sixth method of the maintenance method of the oil odor detecting device of the present invention is the method of the fifth method, wherein when the detection output of the first oil odor detecting sensor continues at a predetermined level or higher for a predetermined time or longer, the oil odor is detected. Therefore, the reliability of oil odor detection is further increased.

The seventh method of the maintenance method of the oil odor detecting device of the present invention is the method of the fifth method, wherein the detection output of the first oil odor detecting sensor is not less than a predetermined level and the second oil odor detecting is Since the oil odor is detected when the detection output of the sensor is equal to or higher than a predetermined level, the reliability of the oil odor detection is further increased.

[Brief description of drawings]

FIG. 1 is a graph showing changes over time in oil odor response and odor intensity detected by a crystal oscillator sensor according to a first embodiment of the present invention.

FIG. 2 is a graph showing a response of an oily odor detected by a crystal oscillator sensor according to a second embodiment of the present invention and a temporal change in odor intensity.

FIG. 3 is a schematic configuration diagram showing a configuration of an oil odor detection device according to a third embodiment of the present invention.

FIG. 4 is a graph showing a response of an oil odor (odor) detected by the oil odor detection device shown in FIG. 3 and a temporal change in odor intensity.

FIG. 5 is a schematic configuration diagram showing a configuration of an oil odor detection device according to a fourth embodiment of the present invention.

FIG. 6 is a flowchart showing an oil odor detection determination method according to a fifth embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a general oil odor detection device.

FIG. 8 is a graph showing a temporal change in odor intensity of oily odor detected by a general crystal oscillator sensor.

[Explanation of symbols]

1 electromagnetic three-way valve 2 purging device 3 crystal oscillator sensor 4 temperature control device 5 electromagnetic three-way valve 6 semiconductor type sensor

Continued front page    F-term (reference) 2G046 AA01 CA09 DC07 DC11 EB04                 2G052 AA06 AB25 AC17 AD28 AD42                       CA03 CA04 CA35 ED15 GA23                       GA26 HB09 JA09

Claims (7)

[Claims] 1. An oil odor detection sensor for detecting an oil odor contained in a fluid to be measured, and a pipe for feeding the fluid to be measured to the sensor, and the detected oil odor intensity can be confirmed as an oil odor detection. A maintenance method for an oil odor detecting device, characterized in that cleaning of the pipe and / or the oil odor detecting sensor is started when a predetermined detection level is reached. 2. An oil odor detection sensor for detecting an oil odor contained in a fluid to be measured and a pipe for feeding the fluid to be measured to the sensor, and the detected oil odor intensity is determined to be an oil odor detection. A method for maintaining an oil odor detection device, characterized in that cleaning of the pipe and / or the oil odor detection sensor is started at a stage when a predetermined second detection level exceeding a predetermined first detection level is reached. . 3. An oil odor detection sensor for detecting an oil odor contained in a fluid to be measured, and a pipe for feeding the fluid to be measured to the sensor, and the detected oil odor intensity is determined to be an oil odor detection. A maintenance method for an oil odor detection device, wherein cleaning of the pipe and / or the oil odor detection sensor is started when the oil odor intensity that is equal to or higher than a predetermined detection level continues for a predetermined time or longer. 4. The maintenance method for an oil odor detection device according to claim 1, wherein the oil odor detection sensor is a crystal oscillator sensor coated with a sensitive film. 5. A first oil odor detection sensor capable of selectively detecting an oil odor contained in a fluid to be measured but having a slow response, and a second oil odor detection sensor having a quick response but having a low selectivity. These are provided with a pipe for feeding the fluid to be measured, and after the first oil odor detection sensor detects an oil odor, the second oil odor detection sensor detects the absence of an oil odor. And / or a method for maintaining an oil odor detecting device, characterized in that cleaning of the oil odor detecting sensor is started. 6. The maintenance method for an oil odor detection device according to claim 5, wherein the oil odor detection is performed when the detection output of the first oil odor detection sensor is at a predetermined level or higher and continues for a predetermined time or longer. 7. The oil odor detection is performed when the detection output of the first oil odor detection sensor is a predetermined level or higher and the detection output of the second oil odor detection sensor is a predetermined level or higher. 5. The maintenance method for the oil odor detection device according to 5.