KR20160034269A - Backwashing Method of Gas Sensor Plumbing - Google Patents

Abstract

The present invention relates to a backwashing method to prevent a connection pipe, a valve, a sensor array space or the like from being polluted by a sample in a measuring method using a gas sensor. The backwashing method is introduced to make up for a disadvantage of a conventional normal washing method frequently used to prevent pollution. According to the conventional normal washing method, because the direction where a sample is introduced is equal to the washing direction, it is difficult to clean a connection pipe before clean air from a clean air generator is introduced. Particularly, in a case where moisture is introduced, no method to prevent the gas sensor from easily being damaged by the moisture is suggested. According to the present invention, the backwashing method is a method to perform a backwashing with the connection pipe and the valve. The backwashing method has an advantage where cleaning up to the entrance of the suction part where the sample is introduced is possible, a degree of precision of measurement is increased by discharging the moisture, which may be generated in the surroundings of the sensor and the interior of the connection pipe due to the introduced moisture, to the outside, and reduction of the life span of the sensor and damage to the sensor can be prevented.

Description

BACKWASHING METHOD OF GAS SENSOR PLUMBING BACKGROUND OF THE INVENTION [0001]

The present invention relates to a method for measuring gaseous pollutants such as various air pollutants and odor pollutants contained in air (air) using a gas sensor, More particularly, in the case of measuring a pollutant using a gas sensor, external air to be measured is sucked through a pump and passes through a region of the sensing portion where the gas sensor is located. Air and odor pollutants contained in air are measured by electrical signals. In this process, contamination occurs in the portion where the outside air containing contaminants such as a connecting pipe for sucking contaminants contained in outside air, a valve for controlling air flow, and a gas sensor position space flows, Clean air is used for cleaning.

In the case of the cleaning method of existing products, a method of washing in the same direction as the direction in which the sample is sucked is used. The problem with the forward cleaning is that there is a limit in that it is impossible to clean the connection pipe for sucking pollutants contained in the outside air and the valve for controlling the air flow according to the method of cleaning the gas sensor position space, There is a large error in the electrical signal value of the gas sensor due to valve contamination. In contrast, in the present invention, backwashing can be performed using clean air in a direction opposite to the forward direction, which is the direction of sample intake, so that the cleaning of the outside air inflow portion, which is difficult to clean in the conventional method, And a function capable of discharging moisture generated by an external temperature difference to the outside.

Various types of gas sensors have been developed and used, including sensors for detecting harmful gases, and sensors for measuring odors. There are various types of gas measurement sensor products according to the kind of gas to be measured and the use environment to be measured by the gas sensor. The classification according to the purpose of the present invention can be broadly divided into cases in which cleaning is required and cases in which it is not. (Cleaning is the function of flowing clean air to keep the problematic parts clean by the sample.)

For example, in the case of using a city gas sensor, a city gas sensor is mandatory. And the shut-off valve can be operated when the city gas leaks. In this case, the gas sensor is always in contact with clean air and is reacted by leakage of city gas. In other words, since most of the time is in contact with the clean air, there is no problem without managing the sensor pollution.

However, in the case of a gas sensor installed at a point where various pollutants come out, contamination may occur in the gas sensor, the connecting pipe through which the sample flows, and the valve controlling the sample flow. Therefore, in case of a gas sensor installed at a place with a high level of contamination such as a pollutant discharge port, the inside of the suction pipe, the valve, and the sensor may be contaminated if the cleaning operation is not performed. It is possible to prevent accurate measurement due to contamination of the sensor itself, shorten the service life of the sensor, and the like.

The present invention contemplates a cleaning method that is more efficient than the conventional cleaning method by devising a backwashing method among these sensor cleaning methods and that can prevent the sensor from being damaged by discharging moisture generated from the outside or generated by the inside- The purpose of this method is to minimize the maintenance cost of measurement equipment by improving the measurement efficiency of the gas sensor and extending the service life of the sensor.

In the case of measuring gaseous contaminants such as odors by using a gas sensor measuring instrument, the present invention can prevent contamination of a suction pipe, a valve, a sensor array space and the like which may occur during the introduction of a sample, This is a method for preventing the sensor from failing due to disturbing the measurement of the sensor by discharging moisture that can be condensed to the outside.

The present invention relates to a method for solving many problems in the measurement of gaseous pollutants such as odors using commercially available gas sensors. Conventional measurement methods include a connection pipe for sucking pollutants around the general atmosphere (low-concentration gaseous pollutant distribution) that causes odors such as factory chimneys (high-concentration gaseous pollutants) and industrial complexes and livestock facilities; A valve for control, a sensor array space including a sensor, and the like. Accordingly, the space of the connection pipe, the valve, and the sensor array is contaminated due to various gaseous contaminants such as odor substances contained in the inhaled air. In order to solve this phenomenon, clean air generator, which contains activated charcoal or silica gel, is cleaned by external clean air passing through clean air generator And this method can not solve the error due to contamination of the space because it can not clean the suction pipe and the valve for controlling the air flow. <Figure 1> shows the contamination phenomenon of the suction pipe which can confirm the problem of forward washing, and technical solution was needed to solve these problems.

        Sedation before contamination Sedation after contamination

      <Figure 1> Pollution of the suction pipe due to adsorption of gaseous pollutants

Particularly, another problem related to the sensor life in forward washing is that the water is condensed due to the difference from the ambient temperature in the suction pipe and the valve in the process of sucking the gaseous contaminant in the outlet and the general atmosphere, It has been confirmed that the life of the sensor is shortened. In the case of equipment for measuring gaseous pollutants such as existing odors, it is necessary to pass through the connection pipe for suction, the valve for controlling the air flow, and the sensor array space including the sensor in the positive direction, There is a problem of lowering the maintenance cost due to shortening of the life time of the sensor due to the water condensation phenomenon due to the difference between the ambient temperature and the problem to be lowered, and a technical method for solving the problem has been required.

  Accordingly, the present invention has developed a method of cleaning all spaces in a reverse direction of a connection pipe to be sucked, a valve for controlling air flow, and a sensor array space including a sensor. <Figure 2> shows the result of forward cleaning and reverse monitoring with gas sensor. It can be confirmed that an abnormal signal is generated due to the direct influence of condensed water during forward washing, and that the long-term influence of such moisture causes shortening of the life of the sensor and frequent failure, and it is confirmed that the sensor needs to be frequently replaced . However, from the application of the backwashing technique, it can be seen that the two gas sensors included in the sensor array continuously maintain their performance.

  In order to solve the above-mentioned problems, the present invention has developed a back washing method to improve the life of the sensor by cleaning the sensor array space, the valve and the suction pipe in the reverse direction, and to improve the efficiency and stability of the measurement result by the sensor. The application of the backwashing technology can reduce the maintenance cost of the smell measuring device using the gas sensor, and can be a revolutionary method for improving the efficiency and stability of the sensor.

           <Figure 2> Comparison between forward washing and reverse washing

In particular, in the reverse cleaning, unlike the forward cleaning, the clean air generator including the adsorbent is advantageously used selectively. In existing products, a clean air generator containing an adsorbent is connected to the sensor array space and cleaned with clean air passed through a clean air generator to clean only the sensor array space and maintain the performance of the sensor itself I can not help it. However, when the method developed in the present invention is used, it has an advantage that it can be selectively used according to the concentration of pollutants. For example, in the case of a discharge port (discharge of high-concentration gaseous pollutants) such as a factory chimney, the concentration of the reacted concentration of the sensor itself is maintained at a high concentration. Therefore, the air that has passed through the clean air generator containing the adsorbent, This method can reduce the cost of replacing the activated carbon adsorbent and reduce the maintenance cost of the gaseous pollutant measuring equipment.

In the case of gaseous pollutants such as odors generated in industrial complexes and livestock facilities where pollutant concentrations are kept at low concentrations, it is necessary to perform backwashing with air from the outside rather than air passing through the clean air generator containing the adsorbent The stability of the sensor can be enhanced. The reason for this is that, in the case of a general atmosphere where a low concentration odor is detected, gaseous contaminants such as odor are not continuously detected, but are detected intermittently according to weather conditions such as wind direction and wind speed. It can be judged by clean air. Therefore, in the case of the gaseous pollutant measurement method using the gas sensor by the backwashing method, it is possible to selectively use the method of cleaning with the outside air passing through the clean air generator including the adsorbent. This method has the advantage of reducing the cost of the adsorbent such as activated carbon and the maintenance cost of the gaseous pollutant measuring equipment.

In the method of measuring gaseous pollutants such as odor using existing gas sensors, since the flow in the forward direction is continuously maintained, except for the space where the sensor for cleaning is carried out using the clean air passing through the adsorbent, Since the valve for controlling the air flow can not be cleaned, there is a problem that an error due to the contamination of these spaces occurs at the time of measurement. In addition, since the flow in the forward direction is continuously maintained, the condensed water generated due to the temperature difference between the inside and the outside of the equipment in the connection pipe and the valve causes shortening of life of the sensor and failure, It is acting as a cause. As a result, the organizations and users who want to use the gaseous pollutant measuring equipment such as odor point out problems in using the equipment, and they are pressing on the purchase budget due to the increase in the maintenance cost, thus posing a problem in the usability of the equipment.

In order to solve the above-mentioned problems, the present invention provides a method for measuring gaseous pollutants using a gas sensor, which prevents contamination of a sensor, a suction pipe, and a valve by using backwashing, It is possible to reduce the maintenance cost of the gas sensor measurement equipment by preventing the damage of the sensor due to moisture and extending the life of the sensor. So that accurate measurement can be performed. The equipment for measuring gaseous pollutants such as odors to which the technology according to the present invention is applied may have a significant effect of increasing the use efficiency of the equipment by improving the efficiency of the equipment and minimizing the maintenance cost.

FIG. 1 is a graph showing the gas flow rate when the gas to be measured is measured by inhalation
FIG. 2 is a schematic view illustrating a case where backwashing is performed using clean air having passed through a clean air generator in the present invention.
Gas flow diagram
FIG. 3 is a graph showing the gas flow rate when backwashing is performed using outside air in the present invention. FIG.
FIG. 4 is a graph showing the gas flow rate when the sample is sucked in the existing gas sensor measuring equipment.
FIG. 5 is a graph showing the gas flow rate

The present invention will now be described in detail with reference to the accompanying drawings. In the present invention, a sample is introduced through a suction pipe from an outlet or a general atmosphere, and a gas included in the intake air is measured and discharged through the gas sensor.

Fig. 1 shows a gas flow for introducing a sample gas. When pump 150 is started to introduce the sample, operate each valve in the control unit as follows. Adjust valve 130 so that the left and right direction are opened and the upward direction is closed. When the valve 150 is operated, when the pump 150 is operated, the gas to be measured is sucked in 110, and the gas and the sensor are reacted through the 115 and 120 gas sensors. Valve 140 is opened to the left and upwards and to the right to close. After the pump 150, the valve 160 is opened in the left and right direction and the upper direction is closed, and the sucked air is discharged for introducing the sample. When the sample is sucked and passed through the sensor, the area between the suction pipe and the sensor is contaminated by the sample gas. When the humidity of the outlet is high or the difference between the inside and outside temperature is large in the process of sucking the outside air, moisture is condensed at the point where the outside air flows A phenomenon occurs.

2 is a clean air flow chart of the backwash process. After suctioning the sample by the method described in FIG. 1, the pump 150 is operated to clean the polluted pipeline and the sensor to suck clean air. Clean air is clean air for cleaning, and foreign air passes through a clean air generator 170 containing an adsorbent such as activated carbon or silica gel, so that foreign matter of the outside air is adsorbed on the adsorbent to generate clean air. When pump 150 is activated, the control unit operates each valve as follows. Valve 140 closes in the left-hand direction and opens upwards and to the right, allowing the outside air to pass through clean air generator 170, which contains adsorbent, creating clean air. In valve 160, the left and upper valves open and the right valve closes, sending clean air to valve 130. Valve 130 opens to the left and upwards and closes to the right. The clean air flows through the 120th gas sensor to the 110th outlet or the common atmosphere. The clean air flow cleans the gas sensor and valve connections. In this process, not only pollutants in the pipes, valves, and gas sensors but also the fine dust and moisture inhaled during sample introduction are discharged to the outside. It is possible to clean up to the suction pipe portion 115 where the gas flowing in at 110 is flowing.

3 is a flow chart of the outside air in the backwashing process. Run pump 150 to suck in the outside air. External air can be applied when the concentration to be measured is the same as that of the outlet, and the clean outside air is selectively used depending on the region to be measured. When pump 150 is activated, the control unit operates each valve as follows. The valve 140 is closed in the left-hand direction, and the upward direction and the rightward direction are opened, and external air flows directly through the backwash inlet 210. In valve 160, the left and top valves are opened and the right side is closed, and external air is sent to valve 130. Valve 130 opens to the left and upwards and closes to the right. Outside air flows through the gas sensor to the 110th outlet or to the common atmosphere. The gas sensor and the valve connector are cleaned through the external air flow. In this process, not only pollutants in the pipes, valves, and gas sensors but also the fine dust and moisture inhaled during sample introduction are discharged to the outside. It is possible to clean up to the suction pipe portion 115 where the gas flowing in at 110 is flowing.

Figure 4 shows the flow of the sample gas in the equipment configuration for forward washing. The valve 130 is opened in the left and right direction, and the upper valve is shut off. When the pump 150 is operated, the sample is sucked through the suction pipes 110 to 115.

Figure 5 shows the clean air flow by the cleaning method used in forward cleaning equipment. After pump 150 is running, close the left valve of valve 130 and open the top and right valves, and clean by sucking clean air through the clean air generator 170. In the forward cleaning method, it is difficult to clean the portion of the suction pipe 115 where the clean air does not pass, so that errors may occur in the measurement because the sample passes through the contaminated suction pipe portion 115 in FIG. In addition, since it is difficult to remove the water introduced into the tube, when there is a large amount of water or a temperature difference between the inside and the outside, water condensation shortens the life of the sensor and easily breaks down.

The present invention solves the problem of difficulty in washing the suction pipe 115 in the conventional forward cleaning and improves the accuracy of the measurement by applying the backwash function of sending the moisture generated from the outside or the moisture generated by the inside-outside temperature difference to the outside, To a backwashing method that prevents failure of a sensor and prolongs its life.

Claims (4)

It is a method for cleaning required in the measurement process using gas sensor. It is a method to backwash connection pipe, valve, sensor array space by performing reverse cleaning instead of conventional forward cleaning The gas sensor according to claim 1, wherein the connection pipe is configured to allow sample suction and backwashing with only three valves and one pump, and the flow of the sample and the flow of the clean air can be controlled. And the constitution of each component and the constitution of the connecting pipe, the valve and the pump so as to remove the moisture inside the connecting pipe caused by the dust, water, and the difference in temperature between the inside and the outside when the sample is inhaled. Cleaning method The method according to claim 1, wherein the clean air generator having an adsorbent (activated carbon or silica gel) built therein is installed to enable backwashing, The backwashing method according to claim 1, wherein the clean air generator is not used during backwashing,

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