JPS6116517Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field to which the idea belongs]

The present invention relates to an infrared gas analyzer that analyzes a gas to be measured, particularly a component gas to be analyzed in the atmosphere, such as carbon dioxide, by determining the amount of infrared absorption depending on the concentration.

[Prior art and its problems] Fig. 2 shows a schematic configuration diagram of an infrared gas analyzer. In the figure, two infrared beams 1V and 1S emitted by light sources L1A and L2A in infrared light source chambers L1 and L2 pass through light transmission windows R7 and R8, and then enter sectors CH that are rotationally driven by a motor M. Therefore, it is periodically interrupted. after that,
One infrared beam 1S is guided as a measurement beam to a measurement tank (measurement cell chamber) S, and the other infrared beam 1V is guided as a reference beam to a reference tank (reference cell chamber).
You will be guided to V. The measurement tank S has light transmission windows R1 and R.
2 is provided, and a measurement gas containing an analyte component gas is guided in the direction of the arrow through introduction pipes Z1 and Z2. The measurement light beam undergoes infrared absorption in this measurement tank S depending on the concentration of the gas to be analyzed.
Further, the reference tank V is similarly provided with light transmission windows R3 and R4, and is filled with a gas that does not absorb infrared rays, such as nitrogen gas. Measuring tank S
The measurement light beam 1S that has passed through the gas-filled detector D and the reference light IV that has passed through the reference tank V
will be guided to. This detector D is connected to the first detection tank (first
detection chamber) D1, and second detection tank (second detection chamber)
Each of the detection tanks D1 and D2 is provided with a light transmission window R5 and R6, respectively, and is filled with the same type of gas as the component gas to be analyzed. First detection tank D
The measurement light beam 1S enters into the second detection tank D2 through the light transmission window R5, and the reference light IV enters into the second detection tank D2 through the light transmission window R6. Therefore, the first detection tank D1 and the second detection tank D2
is heated to different temperatures depending on the intensity of its measurement beam IS and reference beam IV. Each detection tank D
1 and D2 are communicated by a conduit K. This conduit K
The hot wire elements H1 and H2 are arranged close to each other in the center so that they are thermally coupled to each other. Each hot wire element H
1 and H2 form a bridge circuit together with two resistors, and are heated by the power supply to a temperature higher than the ambient temperature. Each detection tank D1, D2 is the measurement light LS
By being heated by the reference beam IV and the reference beam IV, the gas sealed in each detection tank D1, D2 expands, and a gas flow is generated in the conduit K according to the concentration of the gas to be analyzed. This gas flow is converted into electrical signals by hot wire elements H1 and H2. Generally, when measuring the concentration of a component gas to be analyzed using an infrared gas analyzer, a gas extraction device (gas sampling device) is required to extract the gas to be measured from the duct of the plant and introduce it into the analyzer. be. Although various extraction methods are employed in this gas extraction device, FIG. 3 shows a schematic configuration diagram of a conventional example. In the figure, the gas to be measured is sucked by a suction pump 1. When this sucked gas to be measured is cooled by the gas cooler 2, the water vapor contained in the gas to be measured becomes drain (condensed water) and is stored in the drain pot 3. The gas to be measured from which the drain has been separated is introduced into a gas analyzer 8 via a filter 4, a suction pump 1, a protection box 5, a flow meter with a throttle valve 6, and a monitoring filter 7, and after analysis is released into the atmosphere. Note that a protector 9 is provided branching off from the conduit between the filter 4 and the suction pump 1. This protector 9 is used because the suction force of the suction pump 1 is too strong, so if a blockage occurs in the filter 4 or in the middle of the pipe, the pressure in the pipe from the blockage to the suction pump 1 will drop, and the drain pot 3 This is provided to prevent the water inside from being sucked up. Further, the protective box 5 is used to prevent the suction pump 1 from pulsating. In the above-mentioned standard gas extraction device, various components are used depending on the quantitative need for the gas to be measured.
Appropriately selected. Therefore, when measuring the concentration of the component gas to be measured in the atmosphere, at least devices such as the suction pump 1 and the flow meter 6 with a throttle valve are required. For this reason, these devices have drawbacks such as requiring care in handling, requiring installation space, and increasing costs.

[Purpose of invention]

In view of the above-mentioned points, it is an object of the present invention to provide an infrared gas analyzer that eliminates the drawbacks of the prior art, allows for simple and stable introduction and extraction of atmospheric gas, and reduces manufacturing costs.

[Key points of the idea]

In order to achieve this purpose, the present invention
a case having a gas inlet and a gas outlet provided above the gas inlet; a light source chamber disposed within the case and having an infrared light source; comprising a measurement cell chamber that is irradiated with infrared rays, and a detection chamber that is irradiated with infrared rays that have passed through the measurement cell chamber,
The light source chamber is installed below the measurement cell chamber in the case, the detection chamber is installed above the measurement cell chamber in the case, and a gas inlet is provided at the bottom of the measurement cell chamber. , and a gas outlet is provided in the upper part of the measurement cell chamber, and based only on the chimney effect in the measurement cell chamber using the light source as a heat source, the gas inlet of the case and the gas inlet of the measurement cell chamber are provided. The gas to be measured is sucked into the measurement cell chamber, and the gas to be measured in the measurement cell chamber is discharged from the gas outlet of the measurement cell chamber.

[Example of idea]

Embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a schematic diagram showing an embodiment of the present invention. In the figure, parts having the same functions as in FIG. 2 are designated by the same reference numerals. Inside the case 11, there are light source chambers L1 and L2 at the bottom, a measurement cell chamber S and a reference cell chamber V above the light source chambers L1 and L2, and a detection chamber D1 above the measurement cell chamber S and reference cell chamber V.
D2 is placed. Sector in Figure 2
CH and drive motor M are omitted in this figure. The gas inlet Z1 and gas outlet Z2 of the measurement cell chamber S are now open into the case 11. Therefore, the gas to be measured inside the measurement cell chamber S is heated without the need for any additional equipment by using the light source originally required for this analyzer as a convection source, causing thermal expansion, decreasing its density, rising, and causing the gas to rise to the upper part. The gas is discharged into the case 11 from the provided gas outlet Z2. On the other hand, the atmosphere inside the case 11 is introduced from the gas introduction port Z1 provided at the bottom. This atmosphere is therefore continuously released and introduced into the measuring cell chamber S due to the chimney effect. moreover,
The atmosphere inside the case 11 is communicated with the outside atmosphere through a gas intake port 12 and a gas outlet port 13. In this way, the external atmosphere is introduced into the case 11 without using a gas extraction device that forcibly samples the gas to be measured using a pump or the like, and furthermore, due to the temperature difference inside and outside the measurement cell chamber S, the external atmosphere is continuously The concentration of the component gas to be measured is measured. Furthermore, by accommodating the measurement cell chamber S in the case 11, the mutual temperature balance is maintained to suppress the influence of fluctuations in outside temperature, and the wind directly hits the measurement cell chamber. The chimney effect can be maintained stably by avoiding temperature fluctuations, and the gas to be measured can be sampled with good stability. The case also serves as a buffer tank that averages out local concentration unevenness of the gas to be measured. The replacement time and response time cannot be adjusted by providing a case, but by adjusting the temperature difference between the measurement cell chamber S and the atmosphere, and by adjusting the temperature difference between the measurement cell chamber S and the atmosphere. It can be adjusted by adjusting the passage area of the inlet pipe Z1 or the gas outlet pipe Z2, the gas intake port 12 of the case 11, etc. As a result of experiments based on this embodiment, the response time to a 90% response value to a step input could be set to about 1 minute to about 8 minutes. Note that the response speed can be further improved by heating the measurement cell chamber S from the outside.

[Effect of the idea]

As explained above, in the present invention, a light source chamber having an infrared light source, a measurement cell chamber, and a detection chamber are housed in a case having a gas inlet and a gas outlet. Since the gas to be measured is sucked into the measurement cell by the chimney effect based on heating, it is possible to introduce the gas to be measured into the measurement cell chamber and from the measurement cell chamber without using a special gas extraction device. The gas to be measured can be easily and stably discharged, and the manufacturing cost is reduced, which is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram of an infrared gas analyzer according to the prior art, and FIG. 3 is a schematic diagram of a conventional example of a gas extraction device. 11... Case, 12... Gas intake port, 13...
...Gas outlet, L1, L2...Light source chamber, S...Measurement cell chamber, D1...Detector, Z1...Gas introduction hole, Z2...Gas outlet hole.

Claims (1)

[Scope of utility model registration request] a case having a gas inlet and a gas outlet provided above the gas inlet; a light source chamber disposed within the case and having an infrared light source; a measurement cell chamber to which infrared rays are irradiated; and a detection chamber to which infrared rays transmitted through the measurement cell chamber are irradiated; the light source chamber is installed below the measurement cell chamber in the case, and the case installing the detection chamber above the measurement cell chamber in the interior;
A gas inlet is provided in the lower part of the measurement cell chamber, and a gas outlet is provided in the upper part of the measurement cell chamber, and the gas intake of the case is performed based only on the chimney effect in the measurement cell chamber using the light source as a heat source. The gas to be measured is drawn into the measurement cell chamber through the inlet and the gas inlet of the measurement cell chamber, and the gas to be measured in the measurement cell chamber is discharged from the gas outlet of the measurement cell chamber. Features of infrared gas analyzer.