KR20200001516U - Voc detector using explosive proff photo ionizaiton scheme - Google Patents

Abstract

A volatile organic compound meter using explosion-proof photoionization is provided as a field-directed transmitter type that detects the leakage of flammable gas, toxic gas, VOC, displays the concentration in the field, and converts the detection signal into a standard current signal and outputs it to the outside. The volatile organic compound measuring device using the explosion-proof type photoionization method is a photoionization sensor that detects the PID method of the concentration of volatile organic compounds (VOC) contained in the leaked gas in the field up to 1 ppb unit; A housing on which the photoionization sensor is mounted; An analog/digital converter that converts the VOC detected by the photoion sensor into a digital signal; A display unit that displays the concentration and setting parameters of the VOC detected by the photoion sensor; A mode switch for setting a computer-assisted learning mode for adjusting the zero point calibration and the sensitivity calibration of the photoionization sensor; An alarm relay for setting an alarm mode for adjusting the alarm type, alarm 1 and alarm 2 settings; And an embedded microprocessor that controls the operation of the photoionization sensor, processes the detection signal from the photoionization sensor, and controls the photoionization sensor in the corresponding mode when setting the mode of the mode switch or the alarm relay.

Description

VOC DETECTOR USING EXPLOSIVE PROFF PHOTO IONIZAITON SCHEME using an explosion-proof photoionization method

The present invention relates to a volatile organic compound measuring device, and more particularly, to a volatile organic compound measuring device using an explosion-proof photoionization method.

In the place where flammable vapors, flammable gases or flammable dusts are present, explosions or fires may occur if a spark or arc is generated or a machine that may become an ignition source due to high temperatures. Therefore, even if measures such as ventilation, ventilation, and dust removal are taken, a machine that has the potential to become an ignition source such as an electric machine used in the presence of gas and dust of flammable substances still has an explosion-proof structure. . This is called explosion-proof structure. Explosion-proof structure, pressure-proof explosion-proof structure, pressure explosion-proof structure, safety certificate explosion-proof structure, inflow explosion-proof structure, intrinsically safe explosion-proof structure, special There are six types of explosion-proof structures.

After moving into a new building or remodeling (building), the symptoms of sick house syndrome appeared, with no obvious excuses, eyes tingling, sore throat, nose, headache, and vomiting. The cause of this phenomenon was found to be volatile organic compounds emitted from building materials such as plywood or wallpaper and paints and adhesives. These volatile organic compounds (VOC) are toxic environmental pollutants such as acetone, benzene, toluene, ethyl ether and xylene. In Korea, the “Indoor Air Quality Management Act for Multi-Use Facilities” was enacted on May 29, 2003, and indoor air quality management has been established and implemented by each ministry (Ministry of Environment, Ministry of Health and Welfare, Ministry of Labor). In addition, in the indoor air quality management law of the multi-use facility, the manager responsible for the management of the multi-use facility is responsible for maintaining indoor air quality measurement once a year for recommended maintenance standards and once every two years for recommended standards. Therefore, a detector capable of analyzing and measuring volatile organic compounds is needed. However, there is no product developed in Korea, so it is a reality that relies on all foreign products. Foreign products are too expensive to buy products and the market is difficult to form, and most of the measurement range is in ppm, making it difficult to measure accurately. Since the volatile organic compounds in the atmosphere are present in a very small amount of ppb, accurate analysis of this requires an accurate measurement technique in 1 ppb units rather than ppm level analysis.

Patent registration number 10-0977031 {Registration date: August 13, 2010}

The problem to be solved by the present invention is to detect the leakage of flammable gas toxic gas VOC, display the concentration in the field, convert the detection signal into a standard current signal, and output it to the outside using an explosion-proof photoionization method. It is intended to provide a volatile organic compound measuring instrument.

The volatile organic compound measuring apparatus using the explosion-proof type photoionization method according to the present invention comprises: a photoionization sensor that detects the concentration of the volatile organic compounds (VOC) contained in the leaked gas in the field to the PID method up to 1 ppb unit; A housing on which the photoionization sensor is mounted; An analog/digital converter that converts the VOC detected by the photoion sensor into a digital signal; A display unit that displays the concentration and setting parameters of the VOC detected by the photoion sensor; A mode switch for setting a computer-assisted learning mode for adjusting the zero point calibration and the sensitivity calibration of the photoionization sensor; An alarm relay for setting an alarm mode for adjusting the alarm type, alarm 1 and alarm 2 settings; And an embedded microprocessor that controls the operation of the photoionization sensor, processes the detection signal from the photoionization sensor, and controls the photoionization sensor in the corresponding mode when setting the mode of the mode switch or the alarm relay. It is characterized by.

The photoionization sensor includes a pump that continuously sucks the leakage gas at the site; An ultraviolet lamp that emits ultraviolet rays in the leakage gas and ionizes them; An RF coil exciting the ultraviolet lamp; RF generator for generating an RF frequency using a DC power source; An electrode plate made of an anode and a cathode storing (+) ions and (-) ions of VOCs contained in the leakage gas ionized by the ultraviolet lamp; And a preamplifier that amplifies the ionized VOC.

The volatile organic compound measuring apparatus using an explosion-proof photoionization method is an analog amplification circuit that amplifies the output signal of the photoionization sensor (to prevent stability and noise of the output signal); A lamp power control circuit that controls an on time of the ultraviolet lamp, a warm time as a sensor stabilization time after the on time, and an off time with a sensor life extension time; And a backlight LED that illuminates the dark area of the display unit.

The built-in microprocessor may include a transmitter that displays current and voltage signals of the photoionization sensor in a gas concentration on the display unit.

Volatile organic compound measuring device using explosion-proof photoionization method reset switch for releasing the alarm relay; And up and down switches for inputting standard gas values.

The explosion-proof volatile organic compound meter according to the present invention is a field-indicated transmitter type gas meter that detects the leakage of flammable gas toxic gas VOC, displays the concentration in the field, and converts the detection signal into a standard current signal and outputs it to the outside. In the present invention, the transmitter displays the current and voltage signals of the sensor as a gas concentration on the LCD, and converts them into stable standard current signals (4 to 20 mA) and outputs them to the outside. The output 4~20㎃ standard current signal is transmitted to the gas leakage alarm device (GMS-1000/2000) or controllers such as PLC, DDC, MMR, and constitutes an individual or integrated gas monitoring system. It has a variety of accurate functions with a built-in microprocessor. In this design, a high-resolution A/D converter is built in to accurately transmit the indicated value. It is a high/low two-stage alarm contact to interlock various external devices such as fans. Signal transmission over long distances (25km) is possible with an external output of 4 to 20 km. Through the programmed menus, users can set their own usage environment.

As an economic/industrial effect, demand for volatile organic compound measurement detectors such as multi-use facilities, indoor air quality measurement, and indoor air quality measurement related to sick house syndrome increases, and the market area is expanded by lowering high-priced prices at low cost, and exports are made at low prices to create overseas exports. It is possible to increase. As a utilization effect, it is used to measure the concentration of VOCs in the general atmosphere, to measure the concentration of VOCs in industrial sites, to measure indoor air quality (IAQ) VOCs, to measure the concentration of harmful VOCs in chemical facilities, to manage industrial safety and health in industrial sites, and to evaluate the environment. It can be used for agency and service measurement.

1 is a block diagram showing the configuration of a volatile organic compound meter using an explosion-proof photoion method according to an embodiment of the present invention.
FIG. 2 is a view showing the internal configuration of the volatile organic compound meter shown in FIG. 1.
FIG. 3 is a detailed block diagram showing the photoionization type sensor illustrated in FIG. 1.
4 is a design diagram of the PID shown in FIG. 3.
5 is a perspective view showing an example of the PID shown in FIGS. 3 and 4.
6 is a perspective view of the sensor housing shown in FIG. 4.
7 is a view for explaining a wiring method of a volatile organic compound meter using an explosion-proof photoion method according to an embodiment of the present invention.
8 is a diagram illustrating a process of switching from a measurement mode to a CAL mode, an alarm mode, and an option mode according to an embodiment of the present invention.
FIG. 9 is a diagram illustrating a process of the CAL mode shown in FIG. 8.
FIG. 10 is a diagram for explaining a process of the alarm mode shown in FIG. 8.
11 and 12 are diagrams for explaining the process of the option mode shown in FIG. 8.

Hereinafter, a volatile organic compound meter using an explosion-proof photoion method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of a volatile organic compound meter using an explosion-proof photoion method according to an embodiment of the present invention. FIG. 2 is a view showing the internal configuration of the volatile organic compound meter shown in FIG. 1.

1 and 2, the volatile organic compound measuring apparatus using the explosion-proof photoion method according to an embodiment of the present invention is a photoionization sensor 100, a housing 2, an analog/digital converter 300, a display unit ( 500), a mode switch 210, an alarm relay 215, an analog amplification circuit 400, a lamp power control circuit 600, a backlight LED 700, and an embedded microprocessor 800.

The photoionization sensor 100 detects the concentration of VOC contained in the leaked gas at the inhaled site to the PID method up to 1 ppb unit.

FIG. 3 is a detailed block diagram showing the photoionization type sensor illustrated in FIG. 1. 4 is a design diagram of the PID shown in FIG. 3. 5 is a perspective view showing an example of the PID shown in FIGS. 3 and 4. 6 is a perspective view of the sensor housing shown in FIG. 4.

3 to 6, the photoionization sensor 100 includes a pump 25 that continuously sucks the leakage gas in the field; An ultraviolet lamp 110 that emits ultraviolet rays in the leakage gas and ionizes them; An RF coil 120 that excites the ultraviolet lamp 25; RF generator 130 for generating an RF frequency using a DC power source; An electrode plate 140 made of an anode and a cathode storing (capturing) (+) ions and (-) ions of VOCs contained in the leakage gas ionized by the ultraviolet lamp 25; And a preamplifier 150 that amplifies the ionized VOC. The pump 25 is capable of smoothly performing a gas detection function in an environment in which a gas sensor cannot be installed or is difficult to manage by continuously inhaling and detecting leakage gas in the field using an automatic suction method.

The photoionization sensor 100 is mounted on the housing 2. The housing 2 is equipped with the photoionization sensor 100, the pump 25 and the display unit 50, an analog AMP board, and a power board and protects them from external shocks and environmental changes.

The analog/digital converter 300 converts the VOC detected by the photoion sensor into a digital signal.

The display 500 displays the concentration and setting parameters of VOC detected by the photoion sensor 100. The display unit 500 displays the detected concentration in real time, allowing the user to immediately check the concentration, and also has an automatic backlight function to easily check the concentration even in a dark environment. The display unit 500 (128*64dot graphic LCD) displays gas concentration values and setting parameters measured by the sensor.

The analog amplification circuit 400 amplifies the output signal of the photoionization sensor 100 to prevent stability and noise of the output signal. The lamp power control circuit 600 controls the on time of the UV lamp 110, the warm time as the sensor stabilization time after the on time, and the off time with the sensor life extension time. The backlight LED 700 illuminates the dark area of the display unit.

The mode switch 210 sets a computer assisted learning mode for adjusting the zero point calibration and the sensitivity calibration of the photoionization sensor 100. The alarm relay 215 sets an alarm mode for adjusting the alarm type, alarm 1 and alarm 2 set values. The reset switch 220 releases the alarm relay. The up and down switches 230 and 240 enter standard gas values.

6 is a diagram illustrating a process of switching from a measurement mode to a CAL mode, an alarm mode, and an option mode according to an embodiment of the present invention.

FIG. 7 is a diagram illustrating a process of the CAL mode shown in FIG. 6.

6 and 7, in the CAL mode, when the mode switch 210 is pressed in the CAL[ZERO] state, an arbitrary value of “CAL ZERO <0.0%>” is displayed. Then, using a calibration device (not shown), clean air or 100% nitrogen is injected at a flow rate of 500 ml/min for about 1 minute. When the measured value becomes stable after gas injection, press the mode switch 210 and "CAL ZERO [OK]" is displayed. However, if the calibration is not successful, the text "CAL ZERO [FAIL]" is displayed for 2 seconds.

When the mode switch 210 is pressed in the CAL [SPAN] state, an arbitrary value of “SPAN ADJ <20.9 %>” is displayed. The standard gas value is input using the up switch 230 and the down switch 240. When the mode switch 210 is pressed again, an arbitrary value of “SPAN ADJ [20.9%]” is displayed. Using a calibration instrument, a standard gas is injected into the sensing element at a flow rate of 500 ml/min to the photoionization sensor 100 for about 1 minute. When the measured value becomes stable after gas injection, pressing the mode switch 210 displays "CAL SPAN [OK]". However, if the calibration was not successful, the text "CAL SPAN [FAIL]" is displayed for 2 seconds.

8 is a view for explaining the process of the alarm mode shown in FIG. 6.

8, in the process of the alarm mode,

(1) AL TYPE (Alarm type setting

-Four types of settings (L&L, L&H, H&L, H&H)

-Two relays are available for the alarm relay.

(Example) When H&L is set

Relay 1 is high (operates when it is over the set value)

Relay 2 is low (operation when over the set value)

(2) AL RESET

-Alarm relay control method

-Automatic or manual selection

Auto: Relay and alarm LED off according to the set value regardless of the reset switch.

Manual: The relay and status LEDs are off only when the reset switch is pressed.

(3) HI SCALE

-20mA setting compared to FULL SCALE.

(Example) When SCALE: 100 is set

With 4mA analog input: 0 display

With 20mA analog input: 100 display

(4) Alarm 1 (Alarm 1)

-Alarm 1 alarm output according to alarm type setting.

(5) Alarm 2 (Alarm 2)

-Alarm 2 alarm output according to the alarm type setting.

(6) Motor (suction pump flow rate control)

-Flow rate control from 0 to 100 ml/min.

9 and 10 are views for explaining the process of the option mode shown in FIG. 6.

9 and 10, the option mode enters after entering the password 507.

(1) DP POINT (concentration value decimal point setting): Change the decimal point according to the measurement range.

(2) Unit (concentration unit setting): Select three types: %LEL, RMP, %.

(3) Gas type (measured gas display): O ₂ , HCL, etc.

(4) Offset (measurement value correction): The error for the measurement value generated by the measurement unit is corrected by adding or subtracting.

(Example) When offset: +5 is set

When the output error is -5 in the sensing unit, the actual display indicates -5.

Correct the offset by +5 to zero the display.

(5) INITTIME (initialization time): After the power is supplied, the photoionization sensor 100 generates a stable output after a certain time.

(6) AL-BAND (Alarm DEAE band) function is a function that gives the hysteresis value to eliminate this phenomenon, while the relay output continues on/off near the alarm set value.

(Example 1) Alarm 1: 20, Alarm type: H&H, D-band: 3

If the display value is 20 or higher, the alarm is turned on.

(Example 2) Alarm 1: 20, Alarm type: H&H, D-band: 3

If the display value is 20 or more, the alarm is turned on. If the value is 23 or more, the alarm is turned off.

(7) AL TIME (Alarm Delay Time) function is a menu to prevent the occurrence of instantaneous malfunction due to external impact or noise, etc., not the normal operation of the instrument.

(Example) In case of alarm value: 50, DEAD TIME: 5

If the measured value is maintained for more than 5 seconds above the alarm set value, it is recognized as the alarm value.

(8) BAUDRATE: RS-485 baud rate setting

(9) ADDRESS: RS-485 station number setting

(10) Relay 1 [Off]: Check the alarm 1 relay output in self-check mode.

(11) Relay 2 [Off]: Check the alarm 2 relay output in self-check mode.

(12) Relay TR[Off]: Check the alarm TROBLE relay output in self-check mode.

(13) Check analog output in self-check mode.

The built-in microprocessor 800 controls the operation of the photoionization sensor 100, processes the detection signal from the photoionization sensor 100, and sets the mode of the mode switch 210 or the alarm relay 215 In the corresponding mode, the photoionization sensor 100 is controlled. The built-in microprocessor 800 includes a transmitter 810 that displays current and voltage signals of the photoionization sensor in a gas concentration on the display unit. The built-in microprocessor 800 converts the digital signal back to a 4 to 20mA standard current signal and provides signals to various external devices such as PLC, DDC, and RECODER. That is, various artificial intelligence functions are implemented as a digital process based on a micro process, and thus a more convenient, accurate, and efficient gas detection function can be performed.

2: housing
210: mode switch
215: alarm relay
220: reset switch
230: up switch
240: down switch
25: Pump
100: PID sensor
110: UV lamp
120: RF coil
130: RF generator
140: electrode plate
150: preamplifier
400: analog amplification circuit
500: display unit
600: lamp power control circuit
700: backlight LED
800: CPU

Claims (5)

A photoionization sensor that detects the concentration of volatile organic compounds (VOC) contained in the leaked gas at the site of inhalation to the PID method up to 1 ppb unit;
A housing on which the photoionization sensor is mounted;
An analog/digital converter that converts the VOC detected by the photoion sensor into a digital signal;
A display unit that displays the concentration and setting parameters of the VOC detected by the photoion sensor;
A mode switch for setting a computer-assisted learning mode for adjusting the zero point calibration and the sensitivity calibration of the photoionization sensor;
An alarm relay for setting an alarm mode for adjusting the alarm type, alarm 1 and alarm 2 settings; And
Explosion-proof light including an integrated microprocessor that controls the operation of the photoionization sensor, processes the detection signal from the photoionization sensor, and controls the photoionization sensor in the corresponding mode when setting the mode of the mode switch or the alarm relay Volatile organic compound measuring instrument using ionization method. According to claim 1,
The photoionization sensor,
A pump that continuously sucks the leakage gas at the site;
An ultraviolet lamp that emits ultraviolet rays in the leakage gas and ionizes them;
An RF coil exciting the ultraviolet lamp;
RF generator for generating an RF frequency using a DC power source;
An electrode plate made of an anode and a cathode storing (+) ions and (-) ions of VOCs contained in the leakage gas ionized by the ultraviolet lamp; And
Volatile organic compound meter using an explosion-proof photoionization method including a preamplifier to amplify the ionized VOC. According to claim 2,
An analog amplifying circuit that amplifies the output signal of the photoionization sensor (to prevent stability and noise of the output signal);
A lamp power control circuit that controls an on time of the ultraviolet lamp, a warm time as a sensor stabilization time after the on time, and an off time with a sensor life extension time; And
A volatile organic compound meter using an explosion-proof photoionization method further comprising a backlight LED illuminating the dark area of the display unit. The volatile organic compound measuring device of claim 1, wherein the built-in microprocessor includes a transmitter that displays current and voltage signals of the photoionization sensor in a gas concentration on the display unit. According to claim 1,
A reset switch for releasing the alarm relay; And
A volatile organic compound meter using an explosion-proof photoionization method further comprising an up and down switch for inputting a standard gas value.

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