JP2003343794A - Drain trap abnormality detection device and abnormality detection method - Google Patents

Abstract

(57) [Problem] To provide an abnormality detection device and an abnormality detection method for a drain trap that can detect an abnormality before a complete failure of the drain trap with a simple device configuration and can respond quickly. SOLUTION: A detecting means 1 for detecting the presence or absence of drainage in a drain discharge channel 4 of a drain trap D, and the detecting means 1
And a determination means 2 for calculating a drainage time and / or a time interval between drainage and drainage based on a signal from the control unit and determining that the time interval is out of a set range and determining that there is an abnormality. Anomaly detection device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain trap abnormality detection device for detecting the presence or absence of drainage in a drain discharge channel of a drain trap and determining whether or not there is an abnormality, and a drain trap abnormality detection device. Anomaly detection method.

[0002]

2. Description of the Related Art As shown in FIG. 1, a drain trap is provided in each of a cooler of an air compressor and a water separator installed downstream of the cooler of an air compressor constituting a nitrogen production apparatus by low temperature rectification separation. These drain traps
It has a function of automatically discharging, when a certain amount or more of condensed water that has been gas-liquid separated by a water separator or the like is accumulated. However, if a failure occurs in the drain trap, condensed water that is not discharged in the closed state will eventually flow into the downstream side, degrading the performance of the adsorption tower, stopping the nitrogen production device, and in the open state gas from there. It was released and became gas loss.

As a method of detecting the failure of the drain trap, there is a visual method or a method of providing a condensed water level abnormal rise detection sensor on the drain trap itself without the visual observation.

[0004]

However, in the drain trap failure detection method by visual observation, failure detection cannot be expected to be effective in the case of the above-mentioned nitrogen manufacturing apparatus that is continuously operated in an unattended monitoring state. In addition, the conventional condensate level rise detection sensor attached to the drain trap has a drawback that it can detect an abnormal clogged state (complete blockage) of the drain trap, but cannot detect an initial clogged phenomenon or a leak state of the drain trap. there were. . Therefore, an object of the present invention is to provide an abnormality detection device and an abnormality detection method for a drain trap that can detect an abnormality before a complete failure of the drain trap with a simple device configuration and can cope with the abnormality at an early stage. is there.

[0005]

The above object can be achieved by the present invention as described below. That is, the drain trap abnormality detection device of the present invention includes a detection unit that detects the presence or absence of drainage in the drain discharge channel of the drain trap, and a drainage time and / or drainage based on a signal from the detection unit. It is characterized by comprising a determination means for calculating a time interval with the drainage and determining an abnormality when the time is out of a set range. Here, the time interval between drainage means the interval between the end of drainage and the beginning of the next drainage, the interval between the beginnings of drainage, the interval between the ends of drainage, and the middle of drainage. Any time interval may be used as long as it serves as an index of the approximate time interval between drainage, such as the interval between times. Then, the drainage time and the time interval between drainages can be accurately measured using a PLC (Programmable Logic Controller).

In the above, it is preferable that the determining means determines that the state is abnormal even when the state without drainage and / or the state with continuous drainage continues for a certain time or more.

On the other hand, according to the drain trap abnormality detecting method of the present invention, the drainage time and / or the drainage time are detected based on the presence or absence of the drainage while detecting the presence or absence of the drainage in the drain discharge channel of the drain trap.
Alternatively, it is characterized in that the time intervals between the drainage and the drainage are sequentially calculated, and when the time is out of the set range, it is determined to be abnormal.

[0008] In the above, it is preferable to determine that there is an abnormality even when the state without drainage and / or the state with continuous drainage continues for a certain time or longer.

[Advantageous Effects] According to the abnormality detecting device and the abnormality detecting method of the present invention, the property that the drainage time and / or the time interval between drainage and drainage is changed before the drain trap completely fails is utilized. Then, by detecting and calculating this and comparing it with the set range, it is possible to detect an abnormality before the drain trap completely fails with a simple device configuration. In other words, when the drain trap fails and becomes blocked (clogged), the symptom of that is that the time interval between drainage gradually becomes shorter, and conversely the drainage time generally becomes longer. When the drain trap fails and opens, the indication is that the drainage time and / or the time interval between drainages gradually increases, and conversely the drainage time generally shortens. The invention utilizes such a property.

When the determination means determines that there is an abnormality even when the state of no drainage and / or the state of continuous drainage continues for a certain time or more, the state of no drainage and / or the drainage is When the continuous state continues for a certain time or longer, the drainage time and / or the calculation of the time interval between drainage and drainage is also continued,
Where the calculation result of the time interval cannot be output continuously, it is possible to more reliably and early cope with the abnormality by determining that the abnormality is present even when the time has continued for a certain period or more.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of a usage state of a drain trap abnormality detection device of the present invention, and FIG. 2 is a schematic configuration diagram showing an example of a drain trap abnormality detection device of the present invention.

FIG. 1 shows an example in which the drain trap abnormality detection apparatus of the present invention is applied to a nitrogen production apparatus by low temperature rectification separation. In this device, the air from the outside air is compressed by the air compressor 1
After being compressed in 1 and cooled to room temperature in the cooler 12,
Dust is removed by the filter 13, cooled further by the refrigerator 14, and condensed water is separated by the water separator 15. After that, the gas component is introduced into the adsorption device 16, the impurities are preliminarily purified, and then introduced into the rectification device 17, and nitrogen gas or the like is produced by the rectification separation.

At that time, the cooler 12, the filter 13,
The water separator 15 is provided with drain traps D1 to D3 for draining condensed water, which is formed by condensing condensed water in the taken-in air.
The drain traps D1 to D3 have a function of automatically discharging the condensed water separated from the water separator 15 or the like when a certain amount or more is accumulated.

As shown in FIGS. 1 and 2, the abnormality detecting device for the drain trap of the present invention is provided with a detecting means 1 for detecting the presence or absence of drainage in the drain discharge passage 4 of the drain trap D. The embodiment shown in FIG. 2 shows an example in which the detection means 1 is a pair of electrodes that can detect the presence or absence of drainage by a change in electrical resistance (that is, a change in current between electrodes). Such an electrode may be provided in the horizontal portion (position P1) or the vertical portion (position P2) of the drain discharge flow path 4. In each case, an example of arranging electrodes is shown in FIG.
It shows in (c). Specifically, there are two electrodes, and the transparent joint block may be inserted into the through holes so that the drain water can come into contact with the tips of the transparent joint blocks, and fixed by sealing. Regarding the positional relationship, it is possible to improve the detection accuracy by selecting an appropriate detection position depending on the pipe diameter of the detection portion, the amount of drainage, and the like.

Usually, water has a smaller resistance value than air, so that
The presence of drainage lowers the electrical resistance between the electrodes, which makes it possible to detect the presence or absence of drainage. Such a method can be applied to any drainage liquid having a resistance value smaller than that of air. In addition to such electrical detection, detection by a mechanical switch using a float and a limit switch, optical detection using an optical sensor, thermal detection, or the like can be adopted.

The condensed water is trapped in the drain trap D via the pipe 3 and then discharged to the drain pipe 5 via the drain discharge passage 4.

As shown in FIG. 2, the apparatus for detecting an abnormality in the drain trap of the present invention calculates the drainage time and / or the time interval between the drainage and the drainage based on the signal from the detecting means 1 and calculates the time. The determination means 2 is provided to determine that there is an abnormality when is out of the set range. When it is determined that there is an abnormality, it is possible to notify the abnormal state by an alarm means such as issuing an abnormal alarm by sound, light, abnormal display, or the like.

Further, as shown in FIG. 3, it is possible to notify the administrator of the abnormality by an existing online system for device management. In this example, the detection means 1 is composed of a joint 1b having a pair of electrodes 1a built therein and an amplifier 1c. The current flowing between the electrodes 1a is amplified by the amplifier 1c and output as an on-off signal by a relay circuit. . This signal is PLC (Programmable Logic Controller) 2
After 0, it is sent to TELFLO (Teleflow; remote monitoring system made by Air Liquide), and the telephone line 2
2 is sent to the computer 23 on the manager side.
The computer 23 calculates the drainage time and / or the time interval between the drainages based on the signal from the detection means 1 and determines that there is an abnormality when the time is out of the set range. A program is built in, and this functions as the determination means 2. Further, the abnormal state can be announced by the display device of the computer 23. By using such an online system, the reception control device that centrally monitors a plurality of remote devices can be monitored, so that the administrator can immediately rush to the site in the event of an abnormality.

With such a PLC, ± 10 mse
Since the time can be measured with an accuracy within c, it is possible to catch the displacement state of the relatively short drainage time (about 1.5 seconds) without overlooking.

The state of drainage from the drain trap D is shown in the graph of FIG. 4, for example. In this figure, the time interval of drainage is illustrated as the interval between the end of drainage and the beginning of the next drainage. During this time interval, the drain trap D traps the drainage liquid from the pipe 3 and then drains it in a short time (drainage time). Therefore, it seems that it is usually difficult to detect the abnormality of the drain trap D only from the time when the drainage is performed. However, by performing the measurement as described above, this measured value also causes the failure of the drain trap. It turns out that it can be used for detection.

The calculation of the drainage time and the time interval between the drainages can be performed, for example, according to the flowchart shown in FIG. Drain in step S1
If it is detected, the loop is exited and the drainage time calculation is started in step S2. In step S3, a loop is executed until the drain (drainage) is detected, the loop is exited when it is lost, the drainage time calculation is stopped in step S4, and the drainage time required for drainage is stored in step S5. .
Immediately thereafter, in step S6, the time calculation of the waiting time (drainage time interval) is started, the process to the effect that the plant is stationary is performed in step S7, and the loop of step S1 is repeated until the drain is detected. While repeating such a basic routine, after exiting the loop of step S1, the time calculation of the waiting time (drainage time interval) is stopped in step S10, and the waiting time is stored in step S11. On the other hand, after step S7, it is determined whether or not the stored waiting time is out of the set range in step S8, and if it is out of the set range, an alarm is issued in step S9.

According to this flowchart, for example, when the drain trap D fails and is opened, the drain detection continues and the loop of step S3 cannot be exited.
Since the correct waiting time cannot be output, it cannot be judged as abnormal. Further, when the drain trap D fails and is in the closed state, the state in which the drain is not detected continues and the loop of step S1 cannot be exited.

Therefore, the determining means 2 determines that the abnormality is present even when the state without drainage and / or the state with continuous drainage continues for a certain period of time or more. You will be able to judge. Specifically, for example, a step of determining whether or not the timer that has started the calculation of the waiting time in step S6 is equal to or longer than a preset fixed time is provided, and if the preset time is exceeded, the loop is exited, An abnormal alarm should be given. Further, if the signal from the detection means 1 is constant for a certain period of time or longer, it is possible to determine that the state without drainage and / or the state of continuous drainage continues for a certain period of time or longer. As for the signal input to the control device of the nitrogen manufacturing device, the measured value is received almost continuously at every ten and several msec in the on-site PLC, but when it is received at the remote monitoring side at 1 minute intervals, for example, 5 If the same value continues for a minute, the occlusion is judged to be complete and an alarm can be issued.

The above determination is performed as follows according to the change over time of the drainage time interval as shown in FIG. 6 (the same applies to the change over time of drainage time). Figure 6 case
In 1), there is a case where the drain trap D fails and becomes open, and as a symptom of this, the time interval of drainage gradually increases. In this case, since the time interval of drainage exceeds the set range at the time t1, it is possible to detect the abnormality at a time considerably earlier than the time t2 at which the failure completely occurs and the open state occurs. It should be noted that the reason why the time interval of drainage is constant after time t2 is that the drain trap D fails and is in an open state, and drain detection continues, so the loop of step S3 cannot be exited and a new calculation is performed. This is because the specified time interval is not output.

Case 2) is a case where the drain trap D fails and is in a closed state, and as a symptom of this, the time interval of drainage is gradually shortened. In this case, time t3
Since the time interval of drainage is less than the set range, at a time considerably earlier than the time t4 in which a complete failure occurs and a blocked state is reached,
Anomalies can be detected. It should be noted that the time interval of the drainage is constant after the time t4 because the drain trap D malfunctions and remains in a closed state without drain, so the loop of step S1 cannot be exited and a new calculation is performed. This is because the specified time interval is not output.

Case 3) is a case where the drain trap D fails and is in a closed state, and is a complete closed state before showing a sufficient sign of shortening the time interval. In this case, the drainage time interval is completely closed at time t5 before the time interval of drainage falls below the set range. Therefore, as described above, the determination unit 2 determines whether the drainage-free state and / or drainage is It is necessary to determine that there is an abnormality even when the continuous state continues for a certain time or longer.

Similarly, the operating state of the drain trap can be detected by the presence or absence of abnormality in the drainage time of the drainage, and the present invention can be implemented by using this method alone. Further, by combining this method with the determination method as in the above cases 1) to 3), more accurate early abnormality detection can be performed.

The drain trap abnormality detection method of the present invention can be carried out by using the above-described apparatus, and the presence / absence of drainage can be detected while detecting the presence / absence of drainage in the drain discharge channel of the drain trap. Based on the above, the drainage time and / or the time interval between the drainage and the drainage are sequentially calculated, and when the time is out of the set range, it is determined to be abnormal.
INDUSTRIAL APPLICABILITY The present invention is particularly effective for a nitrogen production device by low-temperature rectification separation which is always operated unattended.

[Other Embodiments] Other embodiments of the present invention will be described below. (1) In the above-described embodiment, an example in which a fixed setting range is used as a reference when determining whether or not the time interval of drainage deviates from the setting range has been described. May be varied according to atmospheric conditions and the like.

For example, when the moisture contained in the air from the outside is discharged as in a nitrogen production apparatus by low temperature rectification separation, the drain amount changes according to the humidity, temperature, temperature of the atmosphere, and the like. There are cases. At that time, for example, by changing the setting range as the determination reference according to the change of humidity, it becomes possible to detect the abnormality with higher accuracy, and it is possible to cope with the abnormality of the drain trap earlier.

(2) In the above-mentioned embodiment, an example in which the present invention is applied to a nitrogen production apparatus by low temperature rectification separation is shown.
INDUSTRIAL APPLICABILITY The present invention can be applied to any device as long as it has a drain trap having a function of automatically discharging the drained liquid from the device when the drainage is accumulated above a certain level.

(3) In the above-described embodiment, an example is shown in which it is determined that there is an abnormality if the time interval of drainage is out of the set range even once, but in the present invention, drainage is performed twice or more consecutively. It may be judged that there is an abnormality only when the time interval of the liquid is out of the set range, and it is abnormal only when the time interval of drainage is again out of the set range within a certain time from the time of the first deviation. May be determined. By performing such a determination, for example, when the detection unit detects the presence or absence of drainage, even if there is a detection error of the state with drainage, it is not judged as abnormal and the operation of the device is performed. You will be able to continue.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a usage state of a drain trap abnormality detection device of the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a drain trap abnormality detection device of the present invention.

FIG. 3 is a schematic configuration diagram showing another example of the drain trap abnormality detection device of the present invention.

FIG. 4 is a graph showing a drainage state from a drain trap.

FIG. 5 is a flowchart showing an example of a calculation regarding a time interval of drainage.

FIG. 6 is a graph schematically showing an example of changes over time of drainage time intervals.

[Explanation of symbols]

1 detection means 2 Judgment means 4 Drain discharge channel D drain trap D1 to D3 drain trap

Claims (4)

[Claims] 1. A detector for detecting the presence or absence of drainage in a drain discharge channel of a drain trap, and a drainage time and / or a time interval between drainage and drainage is calculated based on a signal from the detector. An abnormality detection device for a drain trap, comprising: a determination unit that determines an abnormality when the time is out of a set range. 2. The determination means is a state without drainage and / or
Alternatively, the abnormality detecting device for the drain trap according to claim 1, wherein the abnormality detecting apparatus determines that the abnormality is abnormal even when the state of continuous drainage continues for a certain time or more. 3. The drainage time and / or the time interval between drainages are sequentially calculated based on the presence / absence of drainage while detecting the presence / absence of drainage in the drain drainage channel of the drain trap. An abnormality detection method for a drain trap that determines an abnormality when the time deviates from the set range. 4. The method for detecting an abnormality in a drain trap according to claim 3, further comprising determining that there is an abnormality even when the state without drainage and / or the state with continuous drainage continues for a certain time or longer.