KR20110026918A - Gas monitoring system with cleaning unit for sampling ports - Google Patents

Abstract

PURPOSE: A gas monitoring system is provided to obtain reliable measurement data by rapidly discharging sampling air from a sampling tube. CONSTITUTION: A plurality of sampling ports(1100) suction sampling air. A detector(1200) is connected to at least one selected sampling port and measures the suctioned sampling air. A sampling pump(1300) suctions the sampling air to the sampling port connected to the detector. A cleaning pump(1400) suctions the sampling air to the sampling ports except for the sampling port connected to the detector. A controller(1500) controls the operation of the detector and the sampling port.

Description

Gas monitoring system with cleaning unit for sampling ports

The present invention relates to a gas monitoring system that sequentially changes a plurality of sampling ports to measure sampling air at a measurement port, and performs cleaning on the remaining sampling ports.

7 shows a configuration diagram showing a conventional gas analyzer.

Referring to FIG. 7, a conventional gas analyzing apparatus includes a plurality of gas sample line piping 11, in a gas sampling analysis apparatus for connecting a plurality of gas sample line piping to a analyzer 4 using a switching valve. The other two ports of the three sides 21, 22, 23, and 24 provided in the 12, 13, and 14, respectively, are connected to the ports of the other three sides 21, 22, 23, and 24 adjacent to each other. The analyzer 21 is continuously connected to the sides 21, 22, 23 and 24, and the analyzer 4 is connected to a port where the three sides 21, 22, 23 and 24, which become the end of the side close to the analysis sum 4, remain. It is characterized by being connected.

In the conventional gas analyzer including the gas analyzer shown in FIG. 7, the method of extending the sampling port is simply a method of connecting a solenoid valve or using a manifold to inhale and measure sampling air in a desired region. Are being reported.

When using such a conventional multichannel sampling port,

First, there is a problem in that the concentration of the sampling port cannot be measured in real time due to stagnant sampling air that cannot be discharged from the sampling tube.

Second, there is a disadvantage in that the reliability of the gas concentration measurement due to the adsorption of the gas in the sampling tube and the interference by the out gas.

Third, when using the method of removing the stagnant air of the sampling tube by increasing the flow rate of the sampling air, the pressure loss due to the flow rate of the sampling air and the inner diameter and length of the sampling tube is proportional, thus eliminating the stagnant air of the sampling tube. There is a limit to this. In other words, if the flow rate is increased, a pressure loss occurs. As the inner diameter of the tube decreases, the pressure loss appears large, so that a sufficient flow rate is difficult to secure. In order to compensate for this, the inner diameter of the tube should be large. If the inner diameter of the tube is large, the amount of stagnant air increases due to the increase in the tube cross-sectional area and volume, and the amount of gas out of the tube increases.

Fourth, since the measuring devices are set to an optimum flow rate in consideration of measurement gas collection efficiency and gas analysis conditions, it is difficult to change the optimized flow rate for cleaning.

Therefore, there is an urgent need to develop a gas monitoring system of a multi-channel sampling port that can continuously discharge out gas generated from the sampling tube and prevent stagnant sampling air in the sampling tube to obtain reliable measurement results.

An object of the present invention is to provide a gas monitoring system having a plurality of sampling ports and cleaning a port that is not measured by separating a measurement port and a cleaning port.

The present invention provides a gas monitoring system for supplying sampling air at a constant flow rate when cleaning a port that is not measured, and continuously supplying all ports except the measurement port or supplying sampling air only to a port in preparation for the next measurement. To provide.

The present invention provides a plurality of sampling ports 1100 for sucking sampling air 1600; A detector 1200 connected to at least one selected from the sampling port 1100 and measuring the sampling air 1600 suctioned; A sampling pump 1300 which sucks the sampling air 1600 to the sampling port 1100 connected to the detector 1200; At least one cleaning pump (1400) for sucking the sampling air (600) to the remaining sampling ports (1100) except for the sampling port (1100) connected to the detector (1200); And a controller 1500 that controls operations of the sampling port 1100 and the detector 1200. The sampling port 1100 is divided into a measurement port 1110 to which the detection unit 1200 is connected and a cleaning port 1120 to which the detection unit 1200 is not connected, and the control unit 1500. ) Sequentially changes the selection of the measurement port 1110 and the cleaning port 1120.

In addition, the present invention is characterized in that it comprises a flow rate adjusting device 1130 for collecting and adjusting the flow rate of the sampling air 1600 supplied to the sampling port 1100.

The present invention connects the sampling pump 1300 to the measurement port 1110 selected from among the plurality of sampling ports 1100 and the cleaning pump 1400 to the remaining cleaning port 1120. It characterized in that it comprises any one selected from the solenoid valve 1140 or the multi-position valve 1141 controlled by the controller 1500.

On the other hand, the present invention, while measuring the concentration of the contaminants contained in the sampling air 1600 in the selected measurement port 1110 of the sampling port 1100, the cleaning port remaining except the measurement port 1110 Each of the ports 1120 may be continuously supplied with the sampling air 1600 by the cleaning pump 1400 to perform a cleaning operation.

According to the present invention, while the concentration of the contaminant contained in the sampling air 1600 is measured at the measurement port 1110 selected from the sampling port 1100, the cleaning port (except the measurement port 1110) The sampling air 1600 is continuously supplied to the measurement standby port 1121, which is one of the cleaning ports 1120 having the preparation step for the next measurement, from 1120 by the cleaning pump 1400. do.

Gas monitoring system according to the present invention,

First, in measuring gas using a plurality of ports, there is an advantage that reliable measurement data can be obtained by discharging the sampling air stagnant in the sampling tube.

Second, there is a problem that it is difficult to quickly obtain reliable measurement data in the conventional low concentration gas measurement, but by cleaning the port can minimize the interference effect of the sampling tube.

In the core process of the semiconductor industry and display industry, a wide variety of hazardous gases are indispensable. These harmful gases are acidic gases such as fluorine, chlorine, bromine, nitric acid and sulfuric acid, and basic gases such as ammonia and amines, and organic compounds. Etc. In general, their properties are toxic and very oxidative, causing product defects or surface peroxides. In particular, ammonia in the air has a close relationship with semiconductor production yield due to photoresistor deformation and optical microscope clouding, which requires continuous monitoring and management. In particular, the semiconductor and FPD industries manage pollutants at very low levels of pptv-ppbv in order to prevent product defects and improve production yields due to high integration and finer patterns. Recently, automatic monitoring systems have been studied to efficiently manage such extremely low concentrations.

In these environmental monitoring, sampling tubes are commonly used to measure concentrations in different regions. However, when the sampling tube is used, the sampling air residual phenomenon occurs, and when the concentration changes rapidly, there is a problem in that it shows a limitation in accurate concentration measurement due to interference such as adsorption and desorption of the tube. Especially in the case of semiconductor / FPD clean rooms, each process has a control standard for concentration. Exceeding these control levels requires a lot of cost and effort to maintain concentrations below the control levels, such as forced exhaust or replacement of filters. For example, in the case of semiconductor clean rooms, the photo zone manages a very small amount of 1 ppbv or less.In the case of chemical leaks and high concentration contamination of more than several hundred ppbv is identified, forced exhaust is performed along with the process stoppage. Removes contaminants. Again, if the clean room concentration remains below 1 ppbv, forced exhaust is stopped and the process is restarted. As described above, when the downtime for the removal of contaminants is reduced, the cost loss is very large and inefficient. Therefore, it is very important to quickly recover to an appropriate concentration and to accurately monitor the change in concentration to maintain the concentration range within the control value. However, if a leak occurs in a high concentration environment, the tube passed with a high concentration may cause adsorption of gases, resulting in desorption of contaminants from the adsorbed tube, resulting in a less rapid response than the actual environment. There is this. Therefore, process downtime and forced evacuation are required for a long time compared with low concentration. Therefore, accurate and rapid sampling tube concentration interference rejection technology is a very important problem for reliable environmental measurement and management in a monitoring system using a sampling tube.

Automated measuring equipment can be divided into portable type (hand carrier type) which can be carried and measured on site according to mobility, and stationary type (installation type) which is difficult to move. In general, the portable type is mainly used as a leak sensor because it is inexpensive, convenient to move, but less stable than a stationary type, and has low measurement sensitivity and reliability. The portable type does not use a sampling tube or uses a very short sampling tube, so the influence of the sampling tube can be eliminated. On the other hand, the stationary type is widely used for quality control in environments requiring high precision and high reliability such as semiconductors and FPDs because of its high reliability and stability. The concentration is measured by inhaling. Due to mobile constraints, multichannel sampling ports are provided to measure concentrations by connecting a sampling tube to the measuring device to the desired measuring location. The length of the sampling tube is short, ranging from several M to several hundred M. do.

However, when the sampling tube is used, contaminants (outgases) are generated in the sampling tube itself or adsorption occurs in the sampling tube. Therefore, concentration change occurs during the transfer of sampling air, making accurate concentration measurement difficult. Nevertheless, in the past, the development was mainly focused on analytical techniques for measuring trace amounts, and the influence of data due to the outgassing or adsorption of the sampling tube, which is an air vehicle, was overlooked.

In order to solve these conventional problems, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a gas monitoring system having a sampling port cleaning means according to the present invention, FIG. 2 is a block diagram of a gas monitoring system equipped with a multi-position valve according to the present invention, and FIG. 4 is a configuration diagram of an embodiment in which air is continuously supplied to perform continuous cleaning, FIG. 4 is a configuration diagram of an embodiment of cleaning only a cleaning port waiting to be measured, and FIG. 5 is a graph showing an outgas distribution according to cleaning of a sampling port. 6 is a graph showing a distribution of adsorption degree according to cleaning of a sampling port.

Referring to FIG. 1, the gas monitoring system 1000 may include a sampling port 1100, a detector 1200, a sampling pump 1300, a cleaning pump 1400, and a controller 1500. The sampling port 1100 may be sequentially selected as the measurement port 1110 and the cleaning port 1120, and some of the cleaning ports 1120 may be measurement standby ports 1121 according to embodiments. It will be described in detail below.

When sampling airborne contaminants, multi-channel sampling ports can be configured to connect sampling tubes in multiple directions and the remaining ports can be cleaned when sampling specific ports. Referring to FIG. 1, a plurality of sampling ports 1100 may be provided to suck sampling air 1600, and sampling tubes (not shown) may be connected to each of the sampling ports 1100. The sampling port 1100 is a collection of the measurement port 1110 to which the detection unit 1200 for measuring the sampling air 1600 that is sucked is connected and the remaining sampling port 1100 to which the detection unit 1200 is not connected. It may be divided into the in cleaning port 1120. The division of the measurement port 1110 and the cleaning port 1120 is variable and may be sequentially converted by the controller 1500.

Referring to FIG. 1, the measurement port 1110 selected from the sampling port 1100 opens a valve to introduce the sampling air 1600 into a sampler (not shown) to collect contaminants to detect the contaminants 1200. ) To measure the concentration of the pollutant, or to directly enter the detection unit 1200 without the sampler (not shown) to measure the concentration of the pollutant. The sampling pump 1300 may be provided to suck the sampling air 1600 to the measurement port 1110.

Referring to FIG. 1, the remaining sampling ports 1100 except for the sampling port 1100 selected as the measurement port 1110 may be divided into cleaning ports 1120. The cleaning port 1120 performs a cleaning process to solve the above-described conventional problem. The cleaning port 1120 is subsequently selected as the measurement port 1110 to use the cleaning pump 1400 to exclude the interference effect when measuring the concentration of contaminants included in the sampling air 1600. The sampling air 1600 is circulated to the sampling tube (not shown). Although an embodiment using nitrogen gas to perform cleaning may be considered, it is more preferable to flow the sampling air 1600.

At least one cleaning pump 1400 may be provided to suck the sampling air 1600 to the cleaning port 1120. According to a design, an embodiment in which the cleaning pump 1400 is provided in each of the cleaning ports 1120 and one cleaning pump 1400 for collecting the entire cleaning port 1120 and supplying the sampling air 1600. Consider an embodiment provided with).

3 and 4 illustrate two embodiments of cleaning the cleaning port 1120. Referring to FIG. 3, while the measurement port 1110 measures the concentration of contaminants contained in the sampling air 1600, each of the cleaning ports 1120 except for the measurement port 1110 may be disposed in the cleaning port 1120. The sampling air 1600 is continuously supplied by the pump 1400 and thus the cleaning operation is performed. In this embodiment, the cleaning port 1120 is selected as the measurement port 1110 and selects the concentration of the pollutant contained in the sampling air 1600 as the measurement port 1110 after the completion of the measurement. Until it is measured again.

Referring to FIG. 4, while the measurement port 1110 measures the concentration of contaminants contained in the sampling air 1600, the next measurement of the cleaning port 1120 except for the measurement port 1110 is performed. One predetermined cleaning port 1120 may be selected as the measurement standby port 1121. The measurement standby port 1121 is a port having a preparation step for measuring the concentration of contaminants contained in the sampling air 1600 next time, and the sampling air 1600 is continuously operated by the cleaning pump 1400. In this embodiment, the cleaning operation is performed. In this embodiment, the cleaning port 1120 is selected as the measurement port 1110 and after the measurement of the concentration of the contaminants contained in the sampling air 1600 is completed without performing a cleaning operation, the next measurement object When the measurement wait port 1121 is selected, the above-described cleaning operation is performed. The selection of the measurement waiting port 1121 among the cleaning ports 1120 may be selected by the controller 1500. In the embodiment shown in FIG. 4, since there is a waiting time for not performing a cleaning operation, it is preferable to perform a cleaning operation by injecting a large amount of the sampling air 1600 into the measurement waiting port 1121 in a short time.

The cleaning of the cleaning port 1120 may be performed continuously. As shown in FIG. 4, the cleaning port 1120 may be selected as the measuring port 1110 to measure a gas concentration, and then wait for the next measurement. Even if the cleaning operation is selected as the standby port 1121, it is preferable to select the measurement standby port 1121 to remove the outgas with sufficient time margin. In the conventional gas analyzer shown in FIG. 7, even if the residual gas in the pipe is discharged before the gas measurement, the cleaning and sampling must be performed immediately before the measurement because the sampling and the cleaning provided in each port have the same flow path. At the same time, cleaning cannot be performed, which takes a very long time to completely discharge the remaining gas. Therefore, faulty data may be obtained due to the remaining gas, or waiting for a long time to remove the remaining gas, which makes it difficult to measure quickly. According to the present invention, at least one cleaning pump 1400 is provided to suck out the sampling air 1600 in a method of cleaning at the same time as sampling, or to clean the sampling air 1600 at a time prior to measurement. It can be effective.

In addition, uniformity between ports for performing cleaning should be maintained. In the case of the conventional gas analyzer shown in FIG. 7, the solenoid valve is continuously passed, so the pressure loss due to the solenoid valve is very large. There is a problem that cannot be done. In the present invention, the cleaning unit and the sampling unit are separated and all ports are provided in the same structure to solve the problem of uniformity between sampling ports.

1 and 2, the controller 1500 may control operations of the sampling port 1100 and the detector 1200. In addition, the controller 1500 may sequentially change the selection of the measurement port 1110 and the cleaning port 1120, and may sequentially convert the selection of the measurement waiting port 1121.

Referring to FIG. 1, a flow rate adjusting device 1130 may be provided to collect and adjust a flow rate of the sampling air 1600 supplied to the sampling port 1100. The flow regulating device 1130 may be a flow meter, an MFC, an orifice, or a needle valve, and when the cleaning operation of the cleaning port 1120 is performed, the length, the degree of bending, the inner diameter of the sampling tube The flow rate of the sampling air 1600 is adjusted in consideration of the degree of pressure loss due to the change. The flow rate adjusting device 1130 may adjust the flow amount of the sampling air 1600 for each of the plurality of sampling ports 1100. If the flow rate control device 1130 does not exist, the sampling air 1600 may flow into only a specific port of the sampling port 1100 according to the above-described pressure loss, so that the flow rate control device 1130 is provided to prevent this. Preferably, the cleaning operation may be uniformly performed on all the sampling ports 1100.

1 and 2, the solenoid valve 1140 or the multi to connect the sampling pump 1300 to the measurement port 1110 and the cleaning pump 1400 to the remaining cleaning port 1120. Position valve 1141 may be provided. The solenoid valve 1140 or the multiposition valve 1141 may be controlled by the control unit 1500. Of course, the solenoid valve 1140 or the multi-position valve 1141 may utilize various valves according to a design including a gas solenoid valve. In FIG. 2, only the valve located in the region to be sampled of the multi-position valve 1141 is opened so that the sampling air 1600 is supplied by the sampling pump 1300, and at least one valve in the remaining region is provided. An example is connected to the cleaning pump 1400 to perform a cleaning operation by supplying the sampling air 1600. The controller 1500 may control the operation of the solenoid valve 1140 or the multiposition valve 1141, and thus control the sampling pump 1300 and the cleaning pump 1400. That is, the controller 1500 may control operations of the sampling pump 1300 and the cleaning pump 1400 by controlling each port connected to the solenoid valve 1140 or the multiposition valve 1141. In addition, an embodiment in which a separate control device for controlling the operations of the sampling pump 1300 and the cleaning pump 1400 is added according to a design may be considered.

FIG. 5 shows the distribution of outgas according to whether or not a cleaning operation is performed in the gas monitoring system 1000 having a plurality of sampling ports 1100 connected to 100 M of sampling tubes (not shown). The graph of condition (C) is the F-measurement result of the sampling port 1100 without the sampling tube (not shown) connected. The result of performing the cleaning operation by a conventional measuring method using the graph of condition (C) as a comparison target is the graph of condition (A). This is a result of not properly reacting to the concentration of the sampling air 1600 due to the out gas of the sampling tube (not shown). The graph of condition (B) shows the result of performing the cleaning operation according to the present invention in the gas monitoring system 1000 having a plurality of sampling ports 1100 connected to 100 M of sampling tubes (not shown). Indicates. Although the graph of condition (B) is connected to the same sampling tube (not numbered) as the graph of condition (A), the F-measurement results are obtained for condition (C) without connecting the sampling tube (not numbered). Similar to the graph. Therefore, it can be seen that the F- concentration is significantly reduced when the cleaning operation according to the present invention is performed.

6 shows the adsorption distribution according to cleaning by measuring a high concentration region using the gas monitoring system 1000 and then measuring a low concentration region of 0.1 ppbv. The graph of condition (C) is the NH3 measurement result of the sampling port 1100 without the sampling tube (not shown) connected. It can be seen that there is no significant effect even if the low concentration area is measured after measuring the high concentration area without connecting the sampling tube (not given the drawing number). The graph of the condition (A) without performing the cleaning operation maintains a high concentration of about 0.8 ppbv even after 10 hours has elapsed, so it can be seen that it is not suitable for low concentration measurement of 0.1 ppbv. This is because NH3 gas is adsorbed to the sampling tube (not shown). On the other hand, the graph of the condition (B) which performed the cleaning operation according to the present invention becomes similar to the graph of the condition (C) after about 2 hours has elapsed, so that the adsorption of ions in the sampling tube (not shown) It can be seen that the effect of interference can be minimized.

The technical idea should not be interpreted as being limited to the above-described embodiment of the present invention. Various modifications may be made at the level of those skilled in the art without departing from the spirit of the invention as claimed in the claims. Therefore, such improvements and modifications fall within the protection scope of the present invention as long as it is obvious to those skilled in the art.

1 is a configuration diagram of a gas monitoring system having a sampling port cleaning means according to the present invention.

2 is a block diagram of a gas monitoring system equipped with a solenoid valve according to the present invention.

3 is a block diagram of an embodiment in which sampling air is continuously supplied to a cleaning port to perform continuous cleaning.

4 is a configuration diagram of an embodiment of cleaning only a cleaning port waiting to be measured.

5 is a graph showing the distribution of outgas according to cleaning of the sampling port.

6 is a graph showing a distribution of adsorption degree according to cleaning of a sampling port.

7 is a block diagram showing a conventional gas analyzer.

<Description of the symbols for the main parts of the drawings>

4: analyzer 11, 12, 13, 14: inlet pipe

21,22,23,24: trilateral

1000: Gas Monitoring System

1100: sampling port 1110: measurement port

1120 cleaning port 1121 measurement standby port

1130: flow control device 1140: solenoid valve

1141: multi-position valve 1200: detector

1300: sampling pump 1400: cleaning pump

1500 control unit 1600 sampling air

Claims (5)

A plurality of sampling ports 1100 for sucking sampling air 1600; A detector 1200 connected to at least one selected from the sampling port 1100 and measuring the sampling air 1600 suctioned; A sampling pump 1300 which sucks the sampling air 1600 to the sampling port 1100 connected to the detector 1200; At least one cleaning pump (1400) for sucking the sampling air (600) to the remaining sampling ports (1100) except for the sampling port (1100) connected to the detector (1200); And A controller 1500 that controls operations of the sampling port 1100 and the detector 1200; , &Lt; / RTI &gt; The sampling port 1100 is divided into a measurement port 1110 to which the detection unit 1200 is connected and a cleaning port 1120 to which the detection unit 1200 is not connected, and the control unit 1500 is the measurement port 1110. And a sampling port cleaning means, characterized in that to sequentially change the selection of the cleaning port (1120). The method of claim 1, And a flow rate adjusting device (1130) for collecting and adjusting the flow rate of the sampling air (1600) supplied to the sampling port (1100). The method of claim 2, The controller 1500 to connect the sampling pump 1300 to the measurement port 1110 selected from among the plurality of sampling ports 1100 and to connect the cleaning pump 1400 to the remaining cleaning port 1120. Gas monitoring system with a sampling port cleaning means, characterized in that it comprises any one selected from the solenoid valve (1140) or the multi-position valve (1141) controlled by. 4. The method according to any one of claims 1 to 3, Each of the cleaning ports 1120 except for the measurement port 1110 while measuring the concentration of the pollutant contained in the sampling air 1600 in the measurement port 1110 selected among the sampling ports 1100, respectively. And a sampling port (1600) is continuously supplied to the cleaning pump (1400) to perform a cleaning operation. 4. The method according to any one of claims 1 to 3, Of the cleaning ports 1120 except for the measurement port 1110 while measuring the concentration of the pollutant contained in the sampling air 1600 in the measurement port 1110 selected from the sampling port 1100. Sampling port cleaning, characterized in that the sampling air 1600 is continuously supplied to the measurement standby port 1121, which is one of the cleaning ports 1120 having a preparation step for the next measurement, by the cleaning pump 1400. Gas monitoring system with means.

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