JP6503466B2 - Nitrogen gas safety supply monitor for MS and nitrogen gas generator - Google Patents

Description

  The present invention relates to a nitrogen gas safety supply monitor for MS (Mass Spectrometry) and a nitrogen gas generator.

  Heretofore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2015-024408, a gas generator provided with a compressor and a gas separation membrane is known. In JP-A-2003-159517, a hollow fiber separation membrane module is described as an example of a gas separation membrane. Furthermore, Japanese Patent Laid-Open Publication No. 2012-232281 describes a technology related to a filter device for removing dust and the like contained in fluid, and in particular, in paragraph 0114, the moisture separated by the filter is the inner of the filter. After moving downward along the inner circumferential surface of the case, it is described that the water is accumulated in the bottom of the inner case and becomes drain water. Japanese Patent Laid-Open No. 2008-188489 also describes a similar filter device.

Japanese Unexamined Patent Publication No. 2015-024408 Japanese Patent Application Laid-Open No. 2003-159517 JP JP 2012-232281 A Japanese Patent Application Publication No. 2008-188489

  After the compressor compresses the gas containing water, the compressed high-pressure high-temperature gas cools to generate drain water. The drain water is obtained by converting the vapor, which is a gas, into water, which is a liquid. As a countermeasure for drain water, a water filter having a function of filtering the moisture of the compressed air can be provided between the compressor and the gas separation membrane or the like. However, in the event that the water filter fails, the water, in particular water droplets, which should have been removed will flow downstream of the water filter. It is not preferable that such water reach the gas separation membrane, and furthermore, it is not preferable that such water reach the analyzer etc. located downstream of the gas separation membrane.

  A nitrogen gas generator is one of the target devices that the inventor of the present invention has intensively studied in relation to such a problem. Since nitrogen gas is useful as an inert gas, it can be introduced into various analyzers such as mass spectrometers. A mass spectrometer is referred to as Mass Spectrometry, which is also abbreviated as "MS". Depending on the type of analyzer or the like, the required quality of nitrogen gas may differ, and strict limitations may be imposed on the nitrogen concentration and the water content. If the nitrogen gas generator is connected to an analyzer requiring high quality dry nitrogen gas, it is desirable to prevent the nitrogen gas discharged from the nitrogen gas generator from containing even a small amount of water, particularly water droplets. Therefore, the inventor of the present invention has conducted intensive studies on how to protect the gas separation membrane or the analyzer from the drain water accompanying the compressed gas of the compressor.

  The present invention has been made to solve the problems as described above, and provides a nitrogen gas safety supply monitor for MS and a nitrogen gas generation device capable of protecting a gas separation membrane or an analyzer etc. from an excess gas. The purpose is to

  The nitrogen gas safety supply monitor for MS according to the present invention comprises a gas inlet, a gas outlet, a pipe connecting the gas inlet and the gas outlet, and a shutoff valve provided in the middle of the pipe; A water filter provided in the middle of the pipe for filtering the moisture of the gas flowing through the pipe, a water sensor for detecting the water filtered by the water filter, and water of a predetermined amount or more detected by the water sensor And a control unit which closes the shutoff valve when being operated.

  The control unit may record the date and time when the shutoff valve is closed. The control unit may further include notification means for notifying that the shutoff valve has been closed. The notification means may be a light emitting means for visually notifying, a sound producing means for auditory informing, or the like. The notification means is connected to the control unit, and the control unit operates the notification means when the shutoff valve is closed.

  The control unit may record the date and time when the power was turned on. The nitrogen gas safety supply monitor for MS is provided with a power switch for receiving an operation. When the power is turned on by operating the power switch, a system startup process is executed, and a program is created in advance so that the current system startup process execution date and time is stored in the memory in the control unit. Thus, the control unit may record a power on / off history, ie, a system on / off history.

  The pressure sensor provided in the pipe, the humidity sensor provided in the pipe, and a temperature sensor for measuring the ambient temperature of the nitrogen gas safety supply monitor for MS may be further provided. The control unit may record sensor output values of the pressure sensor, the humidity sensor, and the temperature sensor each time a predetermined time elapses. Thereby, the above-mentioned nitrogen gas safety supply monitor for MS may function as a "data logger device".

  A voltmeter for measuring a power supply voltage may be further provided, and the control unit may record the measurement value of the voltmeter each time a predetermined time elapses.

  As a specific example, the control unit may include an input / output interface (I / OIF), an arithmetic processing unit (CPU), a memory, and a timer. The control unit may execute a program that stores a system start date and a shutdown date.

  The control unit determines whether a first step of recording the activation time in the memory, a second step of opening the shutoff valve, and whether a predetermined time determined in advance from a count reference time has elapsed by measurement of the timer. If it is not determined that the predetermined time has elapsed, a third step of waiting for processing until the predetermined time has elapsed, and if it is determined that the predetermined time has elapsed, the sensor output signal is fetched and recorded in the memory When the water detection is performed, the fifth step in which the process jumps to the power-off determination of the eighth step described later when it is determined that the water detection is not performed. It is determined whether the sixth step of closing the shutoff valve, the seventh step of notifying by operating the notification means, and whether the power off operation has been performed, and the power off operation is not performed. In the case where it is determined that the processing has looped to the third step which determines the lapse of a predetermined time, and the power-off operation is performed, the shutoff valve is held closed to store the shutdown date and time Control processing may be performed.

  The nitrogen gas generator according to the present invention comprises an air inlet, a compressor for generating compressed air from the atmosphere introduced from the air inlet, a gas cooler for cooling the compressed air of the compressor, and cooling by the gas cooler A first water filter for filtering the moisture of the compressed air after being discharged, and a compressed air generator for discharging the compressed air from which the water has been filtered by the first water filter, and the compressed air generator A nitrogen gas separator having a nitrogen separation membrane for producing nitrogen from compressed air, and a nitrogen outlet for discharging nitrogen gas separated by the nitrogen separation membrane, the compressed air generator, and the nitrogen gas separator Between the compressed air generator and the nitrogen gas separator, or at the nitrogen outlet of the nitrogen gas separator. A second water filter, a water sensor for detecting water filtered by the second water filter, and a control unit for closing the shutoff valve when water exceeding a predetermined amount is detected by the water sensor And.

  The shutoff valve may be provided in the middle of a gas path between the water filter and the compressor. The shutoff valve may be provided in the middle of a gas path between the nitrogen separation membrane and the water filter. The shutoff valve may be provided between the nitrogen outlet and the nitrogen separation membrane.

  Various variations are conceivable in the structure of the shutoff valve. For example, a solenoid valve, a motor operated valve or a hydraulic valve may be used.

  Various variations are conceivable in the structure of the water filter. As one example, a cylindrical case made of a light transmitting material and closed at both ends, two openings provided on the side of the cylindrical case, and gas flowing in the cylindrical case when gas flows through these two openings And a filter membrane (membrane element) for collecting water.

  Various variations are conceivable in the structure and detection method of the water sensor. The techniques used for various known moisture analyzers can be diverted, and various commercialized moisture analyzers can be diverted. For example, one using electricity or one using light may be used.

  The compressed air generator may have, for example, an air tank in communication with the discharge port of the compressor, and a first air filter in communication with the air tank. The compressed air having passed through the first air filter flows into the gas cooler. In addition, an activated carbon filter and a micro mist filter may be further provided downstream of the first water filter. Furthermore, a pressure sensor may be provided to detect the pressure on the discharge port side of the compressor, specifically the pressure in the air tank. A safety valve may be provided to operate and remove the compressed gas when the pressure on the discharge port side of the compressor becomes abnormally high. As a preferred mode, the compressor may be automatically shut down when the pressure in the air tank reaches a predetermined upper limit value.

  The nitrogen gas safety supply monitor for MS according to the present invention may be interposed between the compressed air generator and the nitrogen separation membrane, or may be interposed between the nitrogen separation membrane and the analyzer to obtain an analyzer etc. Water safety can be improved. When a predetermined amount or more of droplet water is detected in the compressed air, the valve can be closed to close the pipe. It is possible to prevent the downstream nitrogen separation membrane connected to the gas outlet from failing due to the adverse effect of water.

  According to the nitrogen gas generator according to the present invention, the water filter and the water sensor can be interposed between the compressor for generating the compressed air and the nitrogen separation membrane. The valve can be closed to shut off the gas flow when a predetermined amount or more of droplet water is detected in the compressed air. As a result, it is possible to prevent an adverse effect of water on an analyzer or the like that expects nitrogen from the nitrogen outlet. For example, if the droplet water reaches an analyzer or the like connected downstream of the nitrogen separation membrane to receive high purity nitrogen gas, there is a possibility that malfunction may occur, but such a situation can also be prevented.

It is a block diagram showing a nitrogen gas safety supply monitor for MS and a nitrogen gas generator according to an embodiment of the present invention. It is a top perspective perspective view which shows the nitrogen gas safety supply monitor for MS concerning embodiment of this invention. It is a side perspective perspective view showing a nitrogen gas safety supply monitor for MS according to an embodiment of the present invention. It is an example of the flowchart which shows the control content which the nitrogen gas safety supply monitor for MS concerning embodiment of this invention performs. It is another example of the flowchart which shows the control content which the nitrogen gas safety supply monitor for MS concerning embodiment of this invention performs. It is a block diagram which shows the modification of the nitrogen gas generation device concerning embodiment of this invention.

  FIG. 1 is a block diagram showing a nitrogen gas safety supply monitor 20 for MS and a nitrogen gas generator 1 according to an embodiment of the present invention. The nitrogen gas generator 1 includes a compressed air generator 10, a nitrogen gas safety supply monitor 20 for MS, and a nitrogen gas separator 70. The nitrogen gas generator 1 is connected to an external power supply 4. The power source 4 is, for example, a commercial AC power source. The nitrogen gas generator 1 supplies the dried high purity nitrogen gas to a mass spectrometer (MS) 2 as an example. However, this is only an example, and the nitrogen gas generator 1 can also be used for various analysis devices and measurement devices other than the mass spectrometer 2.

(Mass spectrometer)
The basic principle of the mass spectrometer 2 is to ionize substances, separate their ions, and detect the number (intensity) of ions in mass-to-charge ratio (m / z) from the ions separated by the detector. In this way, qualitative and quantitative analysis is performed. The mass spectrometer 2 is used in combination with chromatography to separate substances. For example, it may be LC-MS (high performance liquid chromatography mass spectrometry) using a liquid, or GC-MS (gas chromatography mass spectrometry) using a gas. Atmospheric pressure ionization method (API: atmospheric pressure ionization method (API) such as electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) as a method of ionizing a substance (solution) in LC-MS Many methods are generally used.

  The mass spectrometer 2 uses nitrogen gas when ionizing a substance. Since nitrogen gas is inert, it plays a role of avoiding unnecessary reactions in ionization. The conditions required for nitrogen gas to be used include high purity, being dry, being a stable constant pressure, and being a stable constant flow rate. If the purity of nitrogen gas is low (specifically, other gases such as oxygen are mixed in) or moisture is contained, normal ionization is not performed and an analysis result is abnormal. In addition, even if the pressure or flow rate of the gas becomes unstable, the analysis results become abnormal similarly.

(Compressed air generator)
The compressed air generator 10 is cooled by an air inlet, a compressor 12 for generating compressed air from the atmosphere introduced from the air inlet, a gas cooler 14 for cooling the compressed air of the compressor 12, and a gas cooler 14 And a second air filter 18 and a micro mist filter 15 for filtering the moisture of the compressed air. The compressed air after moisture is filtered by the micro mist filter 15 and the second air filter 18 is discharged from the compressed air generator 10. The micro mist filter 15 and the second air filter 18 correspond to the "first water filter" in the means for solving the above problems.

  The compressed air generator 10 may include, as one example, an air tank 19 in communication with the discharge port of the compressor 12 and a first air filter 17 in communication with the air tank 19 as shown in FIG. 1. The first air filter 17 is in communication with the gas cooler 14. The gas cooler 14 is, for example, a heat exchanger, and more specifically, can be a radiator. An activated carbon filter may be provided further downstream of the second air filter 18 in communication with the gas cooler 14. Furthermore, a pressure sensor 13 may be provided to detect the pressure on the discharge port side of the compressor 12, specifically, the pressure in the air tank 19. A safety valve may be provided to operate and remove the compressed gas when the pressure on the discharge port side of the compressor 12 becomes abnormally high. As a preferred embodiment, the compressor 12 may be automatically shut down when the pressure in the air tank 19 reaches a predetermined upper limit value. The power supply circuit 11 is connected to a power supply 4 such as a commercial AC power supply, and generates a driving power supply for the compressor 12.

  When the moisture-containing atmosphere is compressed, it becomes high-temperature and high-pressure compressed air. When the high temperature and high pressure compressed air is cooled by the gas cooler 14, water droplets (so-called drain water) are generated. A second air filter 18 and a micro mist filter 15 are provided to remove the water droplets. The second air filter 18 and the micro mist filter 15 each have a cylindrical case as a housing and a drain water discharge mechanism. In the embodiment, the second air filter 18, the micro mist filter 15, and the water filter 41 will be described as having similar structures. However, these filters may achieve moisture filtration in different ways, and their specific shapes and structures may differ from one another.

  The compressed air generator 10 compresses the air or air introduced from the air inlet. Since the pressure and temperature of the air are increased by the compression of the compressor 12, the compressed air is rich in saturated steam. For this reason, when it is cooled through the gas cooler 14, drain water is generated as water droplets. In order to remove water, oil and foreign substances contained in the compressed air, the first air filter 17, the second air filter 18, the activated carbon filter 18a, and the micro mist filter 15 are arranged in this order from upstream to downstream of the compressed air. It is provided.

  For detailed specific configurations of the first air filter 17, the second air filter 18, the activated carbon filter 18a, and the micro mist filter 15, various known filter devices may be used. For example, Japanese Patent Laid-Open Publication No. 2012-232281 Or you may utilize the filter apparatus described in Japan Unexamined-Japanese-Patent No. 2008-188489. Therefore, further description is omitted.

(Nitrogen gas separator)
The nitrogen gas separator 70 has a compressed air inlet, a nitrogen separation membrane 74 and a nitrogen outlet 75. In a preferred embodiment, a nitrogen gas regulator 71 for pressure stabilization and a pressure meter 72 for measuring and displaying the pressure value of nitrogen gas are also provided downstream of the nitrogen separation membrane 74 as a preferred embodiment. The compressed air inlet communicates with the gas outlet 24 of the MS nitrogen gas safety supply monitor 20 to receive compressed air. The nitrogen separation membrane 74 generates nitrogen from the compressed air generated by the compressed air generator 10. As an example of the nitrogen separation membrane 74, a hollow fiber separation membrane module described in Japanese Patent Application Laid-Open No. 2003-159517 may be used. Further downstream of the nitrogen gas regulator 71 is connected to the mass spectrometer 2 via a flow meter 73. The nitrogen outlet 75 is a hole for discharging nitrogen gas separated by the nitrogen separation membrane 74. The compressed air generated by the compressed air generator 10 is supplied to the nitrogen gas separator 70 via the nitrogen gas safety supply monitor 20 for MS. By passing the compressed air through the nitrogen separation membrane 74, the dried nitrogen gas can be taken out.

(Nitrogen gas safety supply monitor for MS)
The configuration of the nitrogen gas safety supply monitor 20 for MS described in the block diagram of FIG. 1 will be described below with reference to FIGS. 2 and 3 as well. FIG. 2 is a top perspective perspective view showing the nitrogen gas safety supply monitor 20 for MS according to the embodiment of the present invention. FIG. 3 is a side perspective perspective view showing the nitrogen gas safety supply monitor 20 for MS according to the embodiment of the present invention. The nitrogen gas safety supply monitor 20 for MS has a substantially rectangular parallelepiped shape as a whole, and the inside is hollow. The front cover 6, the gas inlet 22, the gas outlet 24, and the gas inlet 22 And a pipe 26 connecting the gas outlet 24 with the gas outlet 24. The gas inlet 22 and the gas inlet 24 are respectively connected to the compressed air generator 10 and the nitrogen gas separator 70 via an external pipe (not shown). The pipe 26 is composed of three parts of pipes 26a, 26b and 26c. The nitrogen gas safety supply monitor 20 for MS is provided in the middle of the pipe 26c (specifically, at the outlet end) and in the middle of the pipe 26c and filters the moisture of the gas flowing through the pipe 26c. A water filter 41, a water sensor 38 for detecting water filtered by the water filter 41, and a control unit 50 for closing the shutoff valve 44 when the water sensor 38 detects water. The nitrogen gas safety supply monitor 20 for MS further includes a pressure sensor 30 provided in the pipe 26a, a humidity sensor 32 provided in the pipe 26b, and a temperature sensor for measuring the ambient temperature of the nitrogen gas safety supply monitor 20 for MS. And 34. A recess is provided in the upper part of the front cover 6, and the gas inlet 22 and the gas outlet 24 are arranged side by side in this recess. According to the nitrogen gas safety supply monitor 20 for MS in which the above configuration is integrated, there is a convenience that simple installation is possible so as to be interposed between the compressed air generator 10 and the nitrogen gas separator 70 is there. Also, there is an advantage that it is easy to post-install between the already installed compressed air generator 10 and the nitrogen gas separator 70. Although not provided in the MS nitrogen gas safety supply monitor 20, as a modification, the temperature of the compressed air may be measured by providing a temperature sensor for measuring the temperature of the gas in the pipe 26.

  The nitrogen gas safety supply monitor 20 for MS further includes a power supply circuit 48 and a power switch 28. The power supply circuit 48 is connected to an external power supply 4 via a power switch 28. If an example is demonstrated, the power supply circuit 48 contains the well-known converter circuit inside, converts the commercial alternating current voltage from the power supply 4 into a DC voltage, and each structure which the nitrogen gas safety supply monitor 20 for MS incorporates It may produce a DC power supply of The power switch 28 receives a manual operation from the user, and may have any shape. By the user operating the power switch 28, the power on / off of the nitrogen gas safety supply monitor 20 for MS can be switched. When the power switch 28 is turned on, the on command is also transmitted to the control unit 50, and the control unit 50 opens the pipe 26 by opening the shutoff valve 44. When the power switch 28 is turned off, the off command is also transmitted to the control unit 50, and the control unit 50 forcibly switches the shutoff valve 44 to the closed state to close the pipe 26. As a specific example, “on command” and “off command” are actually switching signals representing the switching operation of the power switch 28, and are signals that take two values of high and low.

  In the embodiment shown in FIG. 1, the shutoff valve 44 is provided between the compressed air generator 10 and the nitrogen gas separator 70. A shutoff valve 44 is provided in the middle of the gas path from the compressed air generator 10 to the nitrogen outlet 75, specifically, between the nitrogen separation membrane 74 and the water filter 41. The water filter 41 filters the moisture of the gas flowing between the compressed air generator 10 and the nitrogen separation membrane 74. When the shutoff valve 44 is closed, the flow of gas between the nitrogen separation membrane 74 and the water filter 41 is blocked. The water sensor 38, the water filter 41, the drain water lid 42, and the shutoff valve 44 constitute a gas safety supply unit 40.

  The nitrogen gas safety supply monitor 20 for MS can be interposed between the compressor 12 for generating compressed air and the nitrogen separation membrane 74 so as to be removable later. When droplet water of a predetermined amount or more is detected in the compressed air introduced from the gas inlet 22, the shutoff valve 44 can be closed to close the pipe 26. It is possible to prevent the downstream nitrogen separation membrane 74 connected to the gas outlet 24 from malfunctioning due to the adverse effect of water. Furthermore, there is a problem that when the droplet water reaches an analyzer or the like that is connected downstream of the nitrogen separation film 74 and should receive high purity nitrogen gas, there is a possibility of causing malfunction, but the occurrence of such problems is prevented It can also be done.

  As a preferred mode, the control unit 50 records the date and time when the shutoff valve 44 is closed. A specific example of the means for realizing the recording operation includes a form in which the control unit 50 executes the program recorded in the memory 56.

  As a preferable mode, the control unit 50 further includes “informing means” for notifying that the shutoff valve 44 is closed. In the embodiment, the notification means is provided with a lamp 46 for performing visual notification as an example. The lamps 46 are connected to the control unit 50, and when the shutoff valve 44 is closed, the control unit 50 operates these lamps 46 to emit light. However, instead of the lamp 46 or in addition to the lamp 46, a buzzer or the like may be provided to perform audible notification. Alternatively, the control unit 50 may transmit a warning signal or a warning message to various terminals used by the user through the added wireless communication unit. A specific example of the means for realizing the notification operation includes a form in which the control unit 50 executes a program stored in advance in the memory 56 when the notification is necessary.

  As a preferable mode, the control unit 50 records the date and time when the power supply of the nitrogen gas safety supply monitor 20 for MS was turned on. When the power is turned on by operating the power switch 28, a system start process is executed, and a program is created in advance so that the current system start process execution date and time is stored in the memory 56 of the control unit 50 at that time. It is done. Thus, the control unit 50 records the power on / off history, that is, the system on / off history. A specific example of the means for realizing the history recording operation includes a form in which the control unit 50 executes the program recorded in the memory 56.

  In a preferred embodiment, the nitrogen gas safety supply monitor 20 for MS has at least one sensor that measures a physical quantity for evaluating the physical state of the gas in the pipe 26. In the embodiment, as a specific example of such a sensor, the pressure sensor 30 provided with the nitrogen gas safety supply monitor 20 for MS, the humidity sensor 32 provided in the pipe 26, and the nitrogen gas for MS And a temperature sensor 34 for measuring the ambient temperature of the safety supply monitor 20. The pressure sensor 30 and the humidity sensor 32 can measure the pressure value and the humidity of the gas in the pipe 26, more specifically, the compressed air supplied from the compressed air generator 10. As a preferred embodiment, the control unit 50 records the values of the pressure sensor 30, the humidity sensor 32, and the temperature sensor 34 each time a predetermined time has elapsed. In a further preferred embodiment, the nitrogen gas safety supply monitor 20 for MS comprises a voltmeter 36 for measuring the power supply voltage. Specifically, the voltmeter 36 may be connected to the power supply circuit 48, and may measure the magnitude of the DC voltage generated by the power supply circuit 48. In the embodiment, the pressure sensor 30 and the like included in the nitrogen gas safety supply monitor 20 for MS may be collectively referred to as “each sensor” in order to simplify the description.

  In the preferred embodiment, the control unit 50 records the measurement value of the voltmeter 36 each time a predetermined time elapses, providing the following advantage. The power supply circuit 48 is connected to the power supply 4, and the power supply circuit 11 which is a power supply of the compressed air generator 10 is also connected to the power supply 4. When the voltage of the power supply 4 becomes unstable, both the power supply circuit 48 and the power supply circuit 11 are affected by the power supply instability, so the unstable operation of the power supply 4 is performed by the compressor 12 of the compressed air generator 10. It also affects the behavior of An example of the instability of the power supply 4 is a momentary power failure (so-called momentary power failure). If the operation of the compressor 12 becomes unstable, the pressure and flow rate of the compressed air also affect the quality and quantity of the nitrogen gas finally generated through the nitrogen gas separator 70. It spans. Nitrogen gas quality refers to purity (nitrogen density) and the like, and nitrogen gas amount refers to pressure and flow rate. In this regard, by recording the voltage measured by the voltmeter 36, it is possible to confirm later whether or not the power supply 4 has an unstable operation. As a result, it is possible to investigate the cause of the nitrogen gas becoming unstable qualitatively or quantitatively after the fact.

  In the embodiment, the means for recording the sensor output of the nitrogen gas safety supply monitor 20 for MS specifically means that the control unit 50 executes a program recorded in the memory 56.

  The control unit 50 includes a circuit board main body 51 as shown in FIG. On the circuit board main body 51, each component shown specifically in the block diagram of FIG. 1 is mounted. That is, the control unit 50 includes an input / output (I / O) interface 52, an arithmetic processing unit (CPU) 54, a non-volatile memory 56 (hereinafter simply referred to as a memory 56), a timer 58, an A / D Analog-digital) conversion circuit 53. These components are mounted on the circuit board body 51.

  The input / output interface 52 includes an input connector provided with an input terminal (pin), an output connector provided with an output terminal (pin), and the like. The input / output interface 52 is provided to perform data signal input / output with the outside of the control unit 50. The input / output interface 52 is connected to the pressure sensor 30, the humidity sensor 32, the temperature sensor 34, the voltmeter 36, and the water sensor 38 described above. The input / output interface 52 is also connected to the shutoff valve 44 and the lamp 46.

  The A / D conversion circuit 53 converts an analog output signal of each sensor such as the pressure sensor 30 connected to the control unit 50 into a digital value.

  The CPU 54 is connected to the input / output interface 52, the memory 56, the A / D conversion circuit 53, and the timer 58. The CPU 54 acquires electronic data via the input / output interface 52, the A / D conversion circuit 53, and the memory 56. The CPU 54 performs arithmetic processing on the electronic data by executing a program stored in the memory 56. The CPU 54 stores the operation result in the memory 56 or outputs the operation result from the input / output interface 52 to the outside. The electronic data is, for example, information obtained by converting the sensor output signal from each sensor into a digital value, a light lighting flag for setting whether the light should be turned on or not, or closing the shutoff valve 44 It also includes a valve open / close flag that sets whether to open or open.

  The non-volatile memory 56 may be RAM (Random Access Memory) or ROM (Read Only Memory). For example, an EEPROM (Electric Erasable Programmable Read Only Memory) such as a flash memory (FLASH EEPROM) may be used. Good. Note that volatile memory may be further provided for use in arithmetic processing. Also, an auxiliary storage device (storage device) may be provided, and data may be stored in this auxiliary storage device. When the memory and the auxiliary storage device are comprehensively expressed as "storage means", the CPU 54 performs arithmetic processing, recording and the like by exchanging electronic data with the storage means.

  The timer 58 is for measuring time. Among programs to be executed by the CPU 54, there are processing steps to be periodically executed at fixed time intervals during program execution. For example, the processing for recording the respective values of the pressure sensor 30, the humidity sensor 32, and the temperature sensor 34 described above, and the processing for recording the measurement values of the voltmeter 36 each time a predetermined time has elapsed. In addition, processing may be provided to record the measurement value of the water sensor 38 each time a predetermined time has elapsed. The CPU 54 can execute such processing steps at precise time intervals by referring to the time measurement value from the timer 58.

  The output value of each sensor converted to a digital value by the A / D conversion circuit 53 is processed by the CPU 54. The program executed by the CPU 54 includes a processing step of additionally storing the output value of each sensor in a predetermined storage area of the memory 56 every predetermined time (for example, every minute) set in advance. Thereby, the nitrogen gas safety supply monitor 20 for MS can also function as a "data logger device".

  The nitrogen gas safety supply monitor 20 for MS has a USB (Universal Serial Bus) connector 60. The USB connector 60 is connected to the control unit 50 so that electronic information stored in the memory 56 can be read out. Thus, electronic data extracted via the USB connector 60 can be browsed, processed or edited by an external terminal such as a personal computer. In addition, if the program data in the memory 56 is recorded so as to be rewritable, the program can be corrected and processed by accessing the memory 56 through the USB connector 60. Rewritable recording means, for example, the case where the program is stored in the RAM when the non-volatile memory 56 includes the ROM and the RAM. As described herein, the USB connector 60 functions as "electronic information retrieval means". Therefore, "electronic information extraction means" other than the USB connector 60 may be provided in the nitrogen gas safety supply monitor 20 for MS. For example, various general-purpose communication interfaces other than USB may be adopted, and the connector shape may be provided in accordance with each standard. Also, the communication method is not limited to wired, and a wireless communication unit may be provided, in which case no connector is necessary.

  Many variations are assumed in each configuration according to the embodiment. Some of them will be described below.

  Various variations in the structure of the shutoff valve 44 are conceivable. For example, a solenoid valve may be used. The solenoid valve is also called a solenoid valve, and has a mechanism for opening and closing the valve by moving a plunger using the magnetic force of an electromagnet, and is used for opening and closing control in the pipe 26 through which fluid is passed. A solenoid valve is advantageous in that it has the advantage of quick response and can close the pipe 26 immediately after water detection by the water sensor 38. In addition to the solenoid valve, a motor-driven motorized valve may be used. Further, the invention is not limited to the electric type, and the use of the hydraulic type or the like is not hindered. The shutoff valve 44 may have any drive system and mechanical mechanism, and may be one that can switch at least full open and full close according to the electric signal from the control unit 50. Note that as a modification, the shutoff valve 44 may be capable of continuously adjusting the opening between fully open and fully closed, and uses one that can switch the degree of opening discontinuously, that is, in multiple stages. May be The opening adjustment in such a modification may also be achieved in accordance with the control signal from the control unit 50.

Various variations in the structure of the water filter 41 are assumed. In the embodiment, as an example, a cylindrical case 41a whose both ends are closed, two openings provided at two opposing positions of the side surface of the cylindrical case 41a, and water content of gas collected in the cylindrical case 41a And a filter membrane (membrane element). One opening provided in the cylindrical case 41 a is connected to the pipe 26 c, and the other opening provided in the cylindrical case 41 a is connected to the shutoff valve 44. The gas flows into the cylindrical case 41a from the piping 26c, and the water contained in the gas is filtered by the filter membrane, and then the water filtered gas flows out from the other opening to the shutoff valve 44. The water filtered by the filter membrane is accumulated as water droplets at the bottom of the cylindrical case 41a. At the bottom of the cylindrical case 41a, a drain water hole as a water drain hole is provided, and a drain water lid 42 for manually opening and closing the drain water hole is provided. For a further specific configuration, for example, the filter device described in Japanese Patent Application Laid-Open No. 2012-232281 or Japanese Patent Application Laid-Open No. 2008-188489 is applied, or a suitably modified one is used. Since it is also possible, further explanation will be omitted.

  In the present embodiment, the cylindrical case 41a is formed of a light transmitting resin or glass. This is because, as will be described later, in the present embodiment, the water sensor 38 is of an optical detection type. However, the tubular case 41 a may not be required to be light transmissive because the detection method of the water sensor 38 is electrical, and in such a case, the tubular case 41 a may be non-transparent. In addition, a mechanism (so-called auto drain water) that opens the drain water lid when a certain amount of water is accumulated may be provided. In this case, this water is provided outside the nitrogen gas safety supply monitor 20 for MS. You may direct the tube to be discharged.

Various variations in the structure and detection method of the water sensor 38 are assumed. In the present embodiment, as an example, a light detector for performing optical detection is used as the water sensor 38. The light detector includes, for example, a light emitting unit 38 b made of a photodiode or the like, and a light detecting unit (photo detector) 38 a. The light detection unit 38 a receives the light transmitted from the light emitting unit 38 b through the water filter 41. The water sensor 38 of the optical system can detect the presence or absence of water and the amount of water based on the light reception intensity of the light detection unit 38a and the like by using the difference in the degree of absorption of light according to the amount of water.

  In addition, the technology currently used for the well-known various moisture meter can be diverted to the water filter 41, and the various moisture meter put into practical use can be diverted. For example, not only the one using light but also one using electricity may be used. The water sensor of the electrical type can detect the presence or absence of water and the amount of water by measuring a change in electrical resistance value or a change in electrical capacity according to the amount of water. If a large-sized sensor can be mounted, a microwave moisture meter may be used. Even if water sensors of methods other than these optical methods are used, whether the amount of water in the water filter 41 has reached a predetermined fixed amount by storing measurement values in the memory 56 in the same manner as described above It may be detected whether or not.

  In the present embodiment, it is determined whether the shutoff valve 44 is closed as to whether or not the liquid water has accumulated in the water filter 41 by a constant amount of water. As described above, the "constant amount of water" is an amount such as half, 1/3, 1/5, or 1/10 in the cylindrical case 41a, and it is preferable that the amount of water is not a small amount. The reason is as follows. The nitrogen separation membrane 74 is a membrane for separating and removing the moisture of the inflowing gas to produce dry nitrogen gas. For this reason, the nitrogen separation membrane 74 does not immediately fail even if water vapor whose humidity is within the allowable range flows in. On the other hand, if the shutoff valve 44 is immediately closed because a small amount of moisture is detected, it is not preferable because the compressed air supply at a stable flow rate and pressure is frequently interrupted. Therefore, in the embodiment, when the liquid water accumulated in the cylindrical case 41 a of the water filter 41 reaches a predetermined amount, the control unit 50 closes the shutoff valve 44. Therefore, in the embodiment, the output signal of the water sensor 38 (specifically, the light detection unit 38a) when the liquid water is accumulated in the water filter 41 by a predetermined amount of water is measured in advance, May be stored in the memory 56 of the control unit 50 as a determination value for the blocking valve 44 blockage determination. The "predetermined amount of water" is, for example, half, 1/3, 1/5, or 1/10 of the full state. When the water detection process (step S108) in the flowchart to be described later is performed, the output signal of the light detection unit 38a in the water sensor 38 is compared with the light reception intensity stored in advance. Thereby, it can be detected that the water in the water filter 41 has reached a predetermined amount.

Various variations are also conceivable for the mounting position of the shutoff valve 44. The shutoff valve 44 can be provided anywhere along the gas path from the compressed air generator 10 to the nitrogen outlet 75 or downstream of the nitrogen outlet 75. Specifically, in the embodiment shown in FIGS. 1 to 3, the shutoff valve 44 is provided between the nitrogen separation membrane 74 and the water filter 41. By closing the shutoff valve 44, it is possible to prevent excess compressed air from flowing into the nitrogen separation membrane 74, and further, between the water filter 41 and the nitrogen separation membrane 74 in which water is accumulated. it can. Therefore, the situation in which the stored water in the water filter 41 reaches the nitrogen separation membrane 74 can be reliably prevented. In addition, the shutoff valve 44 may be provided in the middle of the gas path between the water filter 41 and the compressor 12, that is, at any position of the pipe 26. As a result, it is possible to prevent the compressed air having an excess of moisture from flowing into the nitrogen separation membrane 74. Further, the shutoff valve 44 may be provided behind the nitrogen outlet 75 as in the modification of FIG. 6 described later. This is because at least the nitrogen gas generation device 1 can be prevented from discharging the nitrogen gas having an excess of water. The water filter 41 and the shutoff valve 44 do not necessarily have to be adjacent to each other, and may be spaced apart, and another sensor may be interposed between the water filter 41 and the shutoff valve 44. In the nitrogen gas safety supply monitor 20 for MS in the embodiment, the shutoff valve 44 is insufficient only to be able to adjust the flow rate. In the nitrogen gas safety supply monitor 20 for MS, from the viewpoint of securing water safety, at least before reaching the mass spectrometer 2, preferably upstream of the compressed air inlet of the nitrogen separation membrane 74, the shutoff valve 44 It completely occludes any of 26 points.

  FIG. 4 is an example of a flowchart showing control contents executed by the nitrogen gas safety supply monitor 20 for MS according to the embodiment of the present invention. A program created according to the flowchart shown in FIG. 4 is stored in advance in the memory 56 of the control unit 50. The CPU 54 reads out and executes this program from the memory 56 in response to the power on of the nitrogen gas safety supply monitor 20 for MS being turned on by the operation of the power switch 28.

  In the routine shown in the flowchart of FIG. 4, first, the control unit 50 executes a processing step of recording the activation time (S100). The control unit 50 subsequently executes a processing step of opening the shutoff valve 44 (S102).

Next, the control unit 50 executes a processing step of determining whether a predetermined time has elapsed from the count reference time by the measurement of the timer 58 (S104). This processing step is processing for measuring a predetermined time interval, and the time interval may be, for example, one minute (that is, 60 seconds), and may be shorter or longer than one minute. The control unit 50 controls the timer 58 so that the timer 58 measures time with the count reference time as the starting point. When the measurement time of the timer 58 reaches 60 seconds, the determination condition of this process step S104 becomes affirmative. Here, if it is the first determination immediately after activation, this count reference time is the activation time, and the determination result of this processing step becomes affirmative when a predetermined time has elapsed from the activation time. If the determination result of this processing step is affirmed not immediately after start-up but in response to the affirmation determination, the time measurement value of the timer 58 is reset to zero, and the time of the affirmation determination is the latest count It becomes a reference time. Thus, the measurement time of the timer 58 is reset each time the determination result in the processing step S104 becomes affirmative, and the determination condition in the processing step S104 becomes affirmative every time a predetermined time (for example, 60 seconds) is reached. It is possible to proceed to a processing step or the like for performing a later sensor signal acquisition. In addition, the process of process step S104 described here is an example, and as long as it is a program for measuring a predetermined time interval, a specific process does not matter.

If it is not determined that the predetermined time has elapsed from the count reference time, the process returns to the processing step S104, and the process is in a standby state until the predetermined time has elapsed. When it is determined that the predetermined time has elapsed from the count reference time, the control unit 50 subsequently executes a processing step of taking in a sensor output signal of the pressure sensor 30 or the like and recording it in the memory 56 (S106). Next, the control unit 50 executes a processing step of determining whether water detection has been performed (S108). In this step, the control unit 50 determines whether the water in the water filter 41 has reached a predetermined amount of water based on the output signal received from the light detection unit 38a of the water sensor 38, and the water is determined in advance. When the amount of water reaches, the judgment result is positive. If the determination result in step S108 is affirmative, the control unit 50 next executes a processing step of closing the shutoff valve 44 when water is detected (S110). The control unit 50 further executes a processing step of notifying by turning on the lamp 46 (S112).

  When water is not detected in step S108, the control unit 50 causes the process to jump to the power off determination (S114).

  The control unit 50 executes a processing step of determining whether or not the power switch is turned off and there is an instruction to turn off the power (S114). If the power-off operation has not been performed, the control unit 50 loops the process to the predetermined time lapse determination processing step. When the power-off operation is performed, the control unit 50 holds the shutoff valve 44 in the closed state, advances the process to the system shutdown process, and executes the process step of recording the system shutdown date and time (S116) . The system then shuts down as the current routine ends.

  The effects of the nitrogen gas safety supply monitor 20 for MS and the nitrogen gas generator 1 according to the embodiment described above are summarized as follows, for example.

  When performing mass spectrometry, nitrogen gas is required as the sample is introduced into the mass spectrometer 2 (Mass Spectrometer). The nitrogen gas is provided by the nitrogen gas generator 1. Since water is accumulated in the compressed air generator 10 when air is compressed, discharging the water to the outside occasionally is performed automatically. This automatic drainage is realized by an automatic drain function provided to the second air filter 18 and the micro mist filter 15.

  When the second air filter 18 or the micro mist filter 15 in the compressed air generator 10 fails, the excess water gas flows out from the compressed air generator 10. If this water flows in, there is a high possibility that the nitrogen separation membrane 74 will be broken, and if it breaks down, the expensive nitrogen separation membrane 74 will be replaced. Therefore, the shutoff valve 44 is closed at the time of moisture detection using the water filter 41, the water sensor 38, and the shutoff valve 44 provided in the front stage of the nitrogen separation membrane 74 to shut off the compressed air from the compressor 12. In the embodiment, after the pipe 26 is closed by closing the shutoff valve 44, the pressure on the discharge port side of the compressor 12 increases, and the pressure sensor 30 automatically senses the pressure increase to detect the compressor. 12 stops operation.

  Furthermore, if the water passing through the nitrogen separation membrane 74 flows into the mass spectrometer 2, the analysis result of the mass spectrometer 2 and the internal structure of the mass spectrometer 2 are adversely affected. In addition, if the voltage of the power supply 4 is unstable, the pressure or flow rate of nitrogen gas fluctuates, and the analysis accuracy is reduced. In this respect, since the nitrogen gas safety supply monitor 20 for MS according to the embodiment also works as a data logger device, elements (power supply abnormality, ambient temperature, humidity, or pressure) that cause the occurrence of a situation where the shutoff valve 44 is closed Can also be recorded constantly. The nitrogen gas safety supply monitor 20 for MS is the date and time when the power supply for nitrogen gas safety supply monitor 20 for MS was turned on, the date and time when the water detection was interrupted by water detection, and the pressure, humidity, temperature, and power supply voltage periodically. Information can be recorded. By recording these pieces of information, the recording results can be referenced later. By referring to the recording result, it is possible to help clarify the cause of the abnormality of the analysis result, the failure of the mass spectrometer 2 or the like. The recorded content may be transferred to the outside (for example, a personal computer as an example) via the USB connector 60 or wirelessly, and may be used for operation management.

FIG. 5 is another example of a flowchart showing control contents executed by the nitrogen gas safety supply monitor 20 for MS according to the embodiment of the present invention. When water is detected in step S108 described with reference to FIG. 4, the control unit 50 sequentially executes the processing step (S110) for closing the shutoff valve 44 and the lighting processing step ( S112 ) for the lamp 46, and then forced power off. Processing may be performed (S200), and the system may shut down upon completion of the routine.

  The MS nitrogen gas safety supply monitor 20 may not be provided with a data logger function, but may be provided only with a water detection shutoff protection function by the water sensor 38, the shutoff valve 44 and the control unit 50 that controls them. In that case, the pressure sensor 30, the humidity sensor 32, the temperature sensor 34, and the voltmeter 36 may be omitted, and the processing of steps S104 and S106 in the flowchart of FIG. 4 may be omitted. Also, the nitrogen gas safety supply monitor 20 for MS may have no data logger device function, and may be disposed between the mass spectrometer 2 and the nitrogen gas separator 70.

  In the embodiment, the nitrogen gas safety supply monitor 20 for MS, in which components such as the water filter 41, the water sensor 38, the shutoff valve 44, and the pressure sensor 30 are integrated in the housing 5, is provided. However, in order to provide the nitrogen gas generator 1 according to the embodiment, the components do not necessarily have to be integrated in one housing 5. That is, each component in the nitrogen gas safety supply monitor 20 for MS is arranged in component units, and the nitrogen gas generation device 1 having the function of the nitrogen gas safety supply monitor 20 for MS of the embodiment as a whole is provided. It is also good.

FIG. 6 is a block diagram showing a nitrogen gas generator 101 according to a modification of the embodiment of the present invention. In this modification, the nitrogen gas safety supply monitor 20 for MS is replaced with the recording device 120, and the nitrogen gas safety supply monitor 140 for MS is added. In this modification, the nitrogen gas safety supply monitor 140 for MS is connected to the nitrogen outlet 75, in other words, the nitrogen gas safety supply monitor 140 for MS is provided between the mass spectrometer 2 and the nitrogen gas separator 70. Since the nitrogen gas generation apparatus 101 is the same as the nitrogen gas generation apparatus 1 described in FIGS. 1 to 3 with respect to the configuration other than these differences, the corresponding components are denoted by the same reference numerals, I omit it. The nitrogen gas generation apparatus 101 extracts the nitrogen gas safety supply monitor 140 for MS responsible for the hardware part of the water detection / shutoff function in the functions of the nitrogen gas safety supply monitor 20 for MS, and the downstream of the nitrogen gas generation apparatus 101 It is provided on the side. This means that the gas safety supply unit 40 in FIG. 1 is provided on the downstream side of the nitrogen gas generator 101. On the other hand, among the functions possessed by the nitrogen gas safety supply monitor 20 for MS, a recording device 120 in charge of control of the shutoff valve 44 and data logger function is provided. In this modification, as shown in FIG. 6, the control unit 50 incorporated in the recording apparatus 120 is used to control the nitrogen gas safety supply monitor 140 for MS. However, FIG. The “other control unit” that controls the opening and closing of the shutoff valve 44 based on the output signal of the water sensor 38 may be incorporated in the nitrogen gas safety supply monitor 140 for MS. The “other control unit” preferably executes at least the processes of steps S102, S108, and S110 in FIGS. 4 and 5, and further performs the valve closing control of step S116. In addition, notification means such as the lamp 46 may be provided in the nitrogen gas safety supply monitor 140 for MS, and in this case, it is preferable that the “other control unit” also perform the process of step S112.

  Note that the device according to the above embodiment can be modified to another device different from the embodiment, and part of the configuration of the embodiment can be diverted to another application. Hereinafter, this deformation transfer will be described.

The embodiment can be diverted to a gas generator other than nitrogen. That is, the above-mentioned nitrogen gas safety supply monitor 20 for MS can be diverted to the dry gas production device which compresses the gas containing moisture such as the atmosphere and generates the dry gas from the compressed gas. When the gas is compressed by the compressor, drain water is generated by condensation. If the water-rich gas containing drain water is supplied to the separation membrane, a case that is not preferable for the separation membrane is assumed. Furthermore, the excess water gas is not preferable for an apparatus such as the mass spectrometer 2 provided further downstream of the separation membrane. From such a situation, another gas separation membrane can be provided instead of the nitrogen separation membrane 74 inside the nitrogen gas generator 1. As an example of a nitrogen separation membrane that has been put into practical use, there is a thing utilizing the property that a hollow fiber made of polyimide is more likely to transmit oxygen than nitrogen in air. While compressed air flows inside the nitrogen separation membrane (hollow fiber), oxygen selectively permeates through the membrane, and as a result, an oxygen- enriched gas can be obtained at the outlet of the hollow fiber membrane. . It is also assumed that such a membrane that selectively permeates oxygen is diverted as an oxygen separation membrane, and in that case, it is not preferable that the excess water gas flows into the oxygen separation membrane. This is similar to the case where the excess water gas is undesirable for the nitrogen separation membrane 74. For example, in Japanese Patent Application Laid-Open No. 2003-159517, “hollow fiber separation membrane module which selectively permeates at least one gas from mixed gas”, “enriched nitrogen air, enriched oxygen air, dry air, carbon dioxide, A hollow fiber separation membrane module for separating and recovering either hydrogen or organic vapor is described. Based on known techniques, “mixed gas separation membrane” or “gas separation membrane for separating either nitrogen-enriched air, oxygen-enriched air, dry air, carbon dioxide, hydrogen or organic vapor”, The membrane 74 may be substituted. In this case, the “nitrogen gas separator” in the embodiment can be read as a mere “gas separator” in which the type of gas is not limited.

1,101 Nitrogen gas generator 2 mass spectrometer 4 Power 5 housing 6 the front cover 10 compressed air generator 1 1 Power supply circuit 12 compressor 1 3 pressure sensor 14 Gas cooler 15 micro mist filter 17 first air filter 18 Second air filter 18a Activated carbon filter 19 Air tank 20, 140 Nitrogen gas safety supply monitor for MS 22 Gas inlet 24 Gas outlet 26, 26a, 26b, 26c Piping 28 Power switch 30 Pressure sensor 32 Humidity sensor 34 Temperature sensor 36 Voltmeter 38 water sensor 38a light detection unit 38b light emitting unit 40 gas safety supply unit 41 water filter 41a cylindrical case 42 drain water cover 44 shutoff valve 46 lamp 48 power supply circuit 50 control unit 51 circuit board main body 52 input / output interface 53 A / D conversion Circuit 54 CPU
56 memory 58 timer 60 USB connector 70 nitrogen gas separator 71 nitrogen gas regulator 72 pressure meter 73 flow meter 74 nitrogen separation membrane 75 nitrogen outlet 120 recording device

Claims (8)

With a gas inlet,
With a gas outlet,
Piping connecting the gas inlet and the gas outlet;
A shutoff valve provided in the middle of the pipe;
A water filter provided in the middle of the pipe for filtering the moisture of the gas flowing through the pipe;
A water sensor for detecting water filtered by the water filter;
A control unit which closes the shutoff valve when water of a predetermined amount or more is detected by the water sensor;
Nitrogen gas safety supply monitor for MS equipped with.   The nitrogen gas safety supply monitor for MS according to claim 1, wherein the control unit records the date and time when the shutoff valve is closed.   The nitrogen gas safety supply monitor for MS according to claim 1, further comprising notification means for notifying that the shutoff valve has been closed by the control unit.   The nitrogen gas safety supply monitor for MS according to claim 1, wherein the control unit records the date and time when the power is turned on. A pressure sensor provided in the pipe;
A humidity sensor provided in the pipe;
A temperature sensor for measuring the ambient temperature of the nitrogen gas safety supply monitor for the MS;
Equipped with
The nitrogen gas safety supply monitor for MS according to claim 1, wherein the control unit records sensor output values of the pressure sensor, the humidity sensor, and the temperature sensor each time a predetermined time elapses. Further equipped with a voltmeter to measure the supply voltage,
The nitrogen gas safety supply monitor for MS according to claim 1, wherein the control unit records the measurement value of the voltmeter each time a predetermined time elapses. Atmospheric inlet, a compressor for generating compressed air from the atmosphere introduced from the atmospheric inlet, a gas cooler for cooling the compressed air of the compressor, and filtering of moisture of the compressed air after cooling by the gas cooler A compressed water generator, which has a first water filter, and discharges compressed air from which water has been filtered by the first water filter;
A nitrogen gas separator having a nitrogen separation membrane that generates nitrogen from the compressed air generated by the compressed air generator, and a nitrogen outlet for discharging the nitrogen gas separated by the nitrogen separation membrane;
A shutoff valve provided between the compressed air generator and the nitrogen gas separator or at the nitrogen outlet of the nitrogen gas separator;
A second water filter provided between the compressed air generator and the nitrogen gas separator or at the nitrogen outlet of the nitrogen gas separator;
A water sensor for detecting water filtered by the second water filter;
A control unit which closes the shutoff valve when water of a predetermined amount or more is detected by the water sensor;
Nitrogen gas generator equipped with   The nitrogen gas generator according to claim 7, wherein the shutoff valve is provided between the nitrogen separation membrane and the second water filter.

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