JPH0434448Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a flame monitor for a hydrogen flame ionization detector for monitoring the presence or absence of hydrogen flame generation.

Prior Art While continuing analysis using a flame ionization detector that detects organic sample components separated and eluted from a gas chromatograph column, the supply of air or hydrogen gas may be accidentally cut off. In this case, combustion in the hydrogen flame ionization detector is interrupted and the hydrogen flame disappears. In this state, it will be impossible to continue the analysis work, so the operator must be notified of this, and in the case of automatic operation, measures must be taken to prevent future sample components from being introduced into the gas chromatograph, and hydrogen gas must be removed. cut off the supply of
Measures must be taken to ensure safety.
For this reason, a thermocouple is provided above the fuel gas discharge hole of the hydrogen flame ionization detector, and whether or not the hydrogen flame is extinguished is detected from the generation of thermoelectromotive force.

Problems to be Solved by the Invention However, since the analysis conditions differ due to differences in the analyte in the sample components, it is necessary to change the temperature of the flame ionization detector. Therefore, every time the temperature of the flame ionization detector changes,
The detection operating point of the thermocouple must be reset, which is troublesome.

Therefore, in view of the problems of the prior art described above, the present invention detects the presence or absence of hydrogen flame generation without requiring resetting of the detection operating point of the detector even if the analysis conditions are different. It is an object of the present invention to provide a flame monitor for a hydrogen flame ionization detector.

Means for Solving the Problems The present invention has a column for introducing a carrier gas and sample components, an air introduction tube, a hydrogen gas introduction tube, and a hydrogen gas introduction tube, and burns and ionizes the sample components. A cylindrical member equipped with a combustion gas exhaust hole, a holding member whose one end is located above the combustion gas exhaust hole and holds an optical element, a cooling member fixed to the holding member, and a cooling member fixed to the holding member; A flame monitor for a hydrogen flame ionization detector comprising an optical element cooled to room temperature or below by a member, a light source for irradiating light to the optical element, and a light receiver for receiving light output from the optical element. be.

Effect When the cooling member is cooled and the optical element is cooled to below room temperature, moisture based on the combustion state of hydrogen is not discharged from the combustion gas exhaust hole in the combustion gas when the hydrogen flame ionization detector is not ignited. Therefore, no clouding occurs in the optical element, and the light from the light source is received by the light receiver via the optical element. When the hydrogen flame ionization detector is ignited, combustion gas containing moisture based on the combustion state of hydrogen is discharged from the combustion gas exhaust hole, and the optical element is clouded by the moisture. Therefore, the light from the light source is not transmitted to the light receiver via the optical element. Therefore, the presence or absence of hydrogen flame generation can be detected from the presence or absence of an output signal from the light receiver.

Examples Examples of the reflection type flame monitor for a hydrogen flame ionization detector of the present invention will be described below.

FIG. 1 shows a sectional view of an embodiment of the present invention, in which 1 is a base member of a hydrogen flame ionization detector, which includes a conduit 2 to which air is supplied and a conduit to which hydrogen gas is supplied. 3 is provided,
Further, at the lower part of the base member 1, a column 6 is fixed by a nut 4 containing a packing 5. Reference numeral 7 denotes a cap as a cylindrical member attached to the base member 1, and a combustion gas discharge hole 7a is bored in the upper end of the cap. 8 is a combustion nozzle, and 9 is a hydrogen flame during combustion. Reference numeral 10 denotes a holding member fixedly supported by a screw thread provided around the upper part of the cap 7, and this holding member has an inverted L-shaped arm 10a whose one end is positioned above the combustion gas exhaust hole 7a. It is integrally formed. A mirror 12 as a light receiving element and a thermomodule 11 as a cooling member for cooling the mirror 12 are fixed to one end of the arm 10a.

FIG. 2 is a configuration diagram of a flame monitor for detecting the presence or absence of hydrogen flame generation in the apparatus of this embodiment. In the same figure, 13 is the thermo module 11
This is an energizing power source for cooling. 14 is an energizing power source for lighting a lamp 15 as a light source, 16 is a light receiver for receiving reflected light from mirror 12, and 17 is an amplifier for amplification, the output of which is sent to an alarm device (not shown). Sent out.

Next, to explain the operation of the device of this embodiment, the power supply 1
A voltage of No. 3 is applied to the thermomodule 11, and the thermomodule 11 is cooled to 5° to 10° C. below room temperature. The sample components sent together with the carrier gas through the column 6 are mixed with air and hydrogen gas sent from the air introduction tube 2 and the hydrogen gas introduction tube 3, respectively, and burned, and a hydrogen flame 9 is generated from the nozzle 8. let Combustion gas containing moisture based on the combustion state of hydrogen is discharged from the combustion gas exhaust hole 7a of the cap 7. Since the mirror 12 becomes cloudy due to its moisture, even if the light from the lamp 15 is irradiated onto the mirror 12, it is not sent to the light receiver 16, and therefore no output is generated from the amplifier 17, and an alarm (not shown) is generated. There is no energizing of the device.

When the supply of air or hydrogen gas is cut off, combustion stops and the hydrogen flame 9 disappears. Since combustion is stopped, no moisture is generated and the mirror 12 is not fogged. Thereby, the light from the lamp 15 is irradiated onto the mirror 12, and the reflected light from the mirror 12 is transmitted to the light receiver 16. The output photoelectrically converted by the light receiver 16 is input to the amplifier 17, and is sent to an alarm device (not shown) to notify the operator that the hydrogen flame has disappeared.

Note that a transmission type frame monitor can be constructed by using a transmission glass instead of the mirror in the device of this embodiment, but in this case, a light sensor is placed on the back side of the transmission glass, and the light generated on the front side of the transmission glass is The presence or absence of cloudiness can be detected by determining whether or not light transmitted from light sources arranged in a direction perpendicular to the transparent glass is transmitted.

Effects of the invention As explained above, according to the invention, an optical element is arranged above the combustion gas exhaust hole of a cylindrical member of a hydrogen flame ionization detector, this optical element is cooled to below room temperature by a cooling member, and the optical element is cooled to below room temperature by a cooling member. Since the element is configured to photoelectrically detect the presence or absence of clouding due to moisture contained in the hydrogen flame, and then detect the presence or absence of hydrogen flame generation, the analysis conditions will change depending on the target substance, etc. Even if the temperature of the flame ionization detector differs, it is possible to omit the troublesome work of resetting the detection operating point of the detector each time as in conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the essential parts of a flame monitor for a hydrogen flame ionization detector according to the present invention, and FIG. 2 is a diagram showing an optical path system of the flame monitor for detecting cloudiness occurring in a mirror. 1 is a base member, 2 is an air introduction pipe, 3 is a hydrogen gas introduction pipe, 4 is a nut, 5 is a packing, 6 is a column, 7 is a cap, 7a is a combustion gas discharge hole, 8
1 is a combustion nozzle, 9 is a hydrogen flame, 10 is a holding member, 1
0a is the arm, 11 is the thermo module, 12
13 is a mirror, 13 is a power source for cooling the thermomodule 11, 14 is a lamp energizing power source, 15 is a lamp, 16 is a light receiver, and 17 is an amplifier for amplification.

Claims (1)

[Scope of Claim for Utility Model Registration] A device that has a column for introducing a carrier gas and sample components, an air introduction pipe, and a hydrogen gas introduction pipe, and detects the sample components by burning them and ionizing them: a combustion gas discharge hole; a cylindrical member comprising: a holding member whose one end is located above the combustion gas exhaust hole and holds the optical element; a cooling member fixed to the holding member; and a cooling member that is cooled to below room temperature by the cooling member. A flame monitor for a hydrogen flame ionization detector, comprising: an optical element; a light source for irradiating the optical element with light; and a light receiver for receiving the light output from the optical element.