JPH0515087Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to improvements in gas analyzers.

[Conventional technology]

One of the analysis methods used in infrared gas analyzers, etc. is to obtain reference gas by passing part of the sample gas through a reference gas purifier in order to prevent the influence of interference gases contained in the sample gas. There is a so-called comparative method.

FIG. 5 shows a conventional example of a gas analyzer using this comparative method. In the figure, 1 is a filter, and sample gas SG is supplied from the inlet side of the filter.
It filters. Reference numerals 2 and 3 are capillaries connected to the outlet side of the filter 1 and provided in parallel to each other as flow rate adjusting units, and a reference gas purifier for purifying the sample gas SG to obtain the reference gas RG. .

Reference numeral 4 designates a rotary valve serving as a gas switching unit that is equipped with a plate-shaped switching member A inside, and the switching member 4A is rotationally driven by a motor (not shown), 4a and 4b are gas inlets, and 4c and 4d are gas outlets. It is. One gas inlet 4a is connected to the outlet side of the capillary 2, and the other gas inlet 4b is connected to the outlet side of the reference gas purifier 3.

Cells 5 and 6 are connected to the outlet side of the rotary valve 4 and are arranged in parallel with each other, and the gas inlet 5a of one cell 5 is connected to one gas outlet 4c of the rotary valve 4, and the gas inlet 5a of the other cell 5 is connected to the gas outlet 4c of the rotary valve 4. The gas inlet 6a of the cell 6 is connected to the other gas outlet 4d of the rotary valve 4.

A pump 7 is provided on the outlet side of the cells 5 and 6, and the gas from the gas outlets 5b and 6b of the cells 5 and 6 is discharged by the pump 7.

Although not shown, the cells 5 and 6 are each irradiated with light from a light source emitting infrared rays, for example, and the light transmitted through each cell 5 and 6 is configured to enter a detector, respectively.

In the gas analyzer having the above configuration, by operating the rotary valve 4 and switching the switching member 4A between the position shown by the solid line and the position shown by the imaginary line, sample gas SG and Reference gas RG can be supplied alternately (for example, Utility Model Publication No. 57-11251,
(See Special Publication No. 56-48822).

[Problem that the invention attempts to solve]

However, in the gas analyzer having the above configuration, for example, in order to supply sample gas SG and reference gas RG at xl per minute to each cell 5 and 6, sample gas SG at 2xl per minute is passed through filter 1. Therefore, a large amount of sample gas SG is required. Therefore, in addition to the need to increase the capacity of the pump 7, it is necessary to increase the capacity of the filter 1.
Since a large amount of sample gas SG passes through the filter 1, the life of the filter 1 is shortened accordingly, and it is necessary to frequently inspect and replace the filter 1.

The present invention has been made with the above-mentioned considerations in mind, and its purpose is to provide a gas analyzer that requires a small flow rate of sample gas to pass through the filter.

[Means for solving problems]

In order to achieve the above object, the gas analyzer according to the present invention includes a first gas switching section and a second gas switching section, respectively, at the front stage and the rear stage of the cell to which sample gas and reference gas are supplied alternately. At the same time, a reference gas purifier is provided in the gas passage connecting these gas switching sections, and the gases in the gas switching sections are always switched in synchronization with each other, thereby reducing the amount of waste discharged from the cell. The sample gas is supplied to the reference gas purifier, and the reference gas purified in the reference gas purifier is supplied to the cell.

[Effect]

In the present invention, the sample gas that has passed through the filter is supplied to the cell via the first gas switching section,
The gas used as a sample gas in this cell passes through a second gas switching section provided at the rear stage of the cell, reaches the reference gas purifier, where it is converted into a reference gas, and then passes through the first gas switching section. It is supplied to the cell via.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIGS. 1A and 1B and FIG. 2 show a first embodiment of the present invention, which is a so-called double cell type gas analyzer.

In the figure, 11 is a filter, and its inlet side 1
A sample gas SG is supplied to 1a. 12,
Reference numeral 13 denotes a cylindrical first cell and a second cell arranged in parallel to each other on the outlet side 11b of the filter 11, each having gas inlets 12a, 13a and gas outlets 12b, 13b. Although not shown, the first cell 12 and the second cell 13
are each irradiated with light from a light source that emits, for example, infrared rays, and the light transmitted through both cells 12 and 13 is configured to enter the respective detectors.
In addition, in FIG. 2, 12c and 13c are cell windows made of an infrared transparent material, and both cells 12 and 13
Both ends of each are sealed. The light source and detector are arranged in each cell 1.
The cells 2 and 13 are arranged opposite to each other with the cells 12 and 13 sandwiched therebetween.

Again, in FIG. 1, 14, 15, and 16 are a first gas switching section, a second gas switching section, and a reference gas purifier, respectively.

The first gas switching section 14 is a switching section for alternately supplying the sample gas SG and the reference gas RG to the first cell 12 and the second cell 13. Between 13 and
That is, it is provided in front of both cells 12 and 13.

The second gas switching unit 15 supplies the gas used as the sample gas SG in either the first cell 12 or the second cell 13 to the reference gas purifier 16, and A switching unit for discharging the gas used as reference gas RG in either one of the cells 12 and 13 via the pump 17.
and the pump 17, that is, after both the cells 12 and 13.

Furthermore, the reference gas purifier 16 is a purifier for purifying the gas used as the sample gas SG in either the first cell 12 or the second cell 13 to obtain the reference gas RG, First gas switching section 14 and second gas switching section 1
5 and is provided in a gas passage P connecting between the two.

First gas switching section 14 and second gas switching section 15
are shown at positions apart from each other for convenience in FIG.
4b, 15a, 15b and four gas outlets 14
A plate-shaped switching member 20 directly connected to the output shaft of the motor 19 is provided in the switching unit housing 18 comprising the switching unit housing 18, which includes the switching unit housing 18, and a seal for maintaining a seal with the inner circumferential wall of the housing 18. Disk-shaped partition member 2 formed by surrounding the member 21a
1 divides the switching member 20 into upper and lower parts, the upper part is the switching member 14A of the first gas switching part 14, and the lower part is the switching member 15A of the second gas switching part 15.
It is configured as A. In other words, the switching members 14A of the first gas switching section 14 and the second gas switching section 15
The switching member 15A and the switching member 15A are arranged coaxially and are configured to be rotated in synchronization with each other and in the same phase by one motor 19.

In the first gas switching section 14, the gas inlet 14a is connected to the outlet side 11b of the filter 11.
The gas inlet 14b is on the outlet side 16b of the reference gas purifier 16, and the gas outlet 14c is on the first cell 1
The gas inlet 12a of the second cell 13 and the gas outlet 14d are connected to the gas inlet 13a of the second cell 13, respectively, and in the second gas switching section 15,
The gas inlet 15a is the gas outlet 12 of the first cell 12.
b, the gas inlet 15b is connected to the gas outlet 13b of the second cell 13, the gas outlet 15c is connected to the inlet side 16a of the reference gas purifier 16, and the gas outlet 15d is connected to the inlet side 17a of the pump 17, respectively. There is.

Note that the outlet side 17b of the pump 17 is connected to an outlet (not shown).

Next, the flow of gas in the gas analyzer having the above configuration will be explained.

Now, when the switching members 14A and 15A of the first gas switching section 14 and the second gas switching section 15 are in the positions shown in FIG. second cell 13
The gas inlet 14 of the first gas switching section 14 on the front stage side
a and the gas outlet 14c as a sample gas. And this first
The used sample gas SG' that has exited the cell 12 is transferred to the second
The gas is supplied to the reference gas purifier 16 through the gas inlet 15a and gas outlet 15c of the gas switching unit 15, and is purified into the reference gas RG in the reference gas purifier 16. Then, this reference gas RG is supplied to the second cell 13 as a reference gas through the gas inlet 14b and gas outlet 14d of the first gas switching section 14. The used reference gas RG′ that has exited this second cell 13 is then transferred to the second gas switching unit 1.
The gas reaches the pump 17 through the gas inlet 15b and gas outlet 15d of No. 5, and is discharged to the outside.

In the above case, the first cell 12, the second cell 13
function as a measurement cell and a comparison cell, respectively.

Next, the switching members 14A and 15A are rotated 90° clockwise from the state shown in FIG.
When the sample gas SG has passed through the filter 11, it is supplied as a sample gas to the second cell 13 through the gas inlet 14a and gas outlet 14d of the first gas switching section 14. The used sample gas exiting this second cell 13
SG' is supplied to the reference gas purifier 16 through the gas inlet 15b and gas outlet 15c of the second gas switching section 15, and the reference gas purifier 1
6, it is refined into reference gas RG.
This reference gas RG is supplied to the gas inlet 14b and the gas outlet 14c of the first gas switching section 14.
The gas is then supplied to the first cell 12 as a reference gas. The used reference gas RG' that has exited the first cell 12 passes through the gas inlet 15a and outlet 15d of the second gas switching section 15, reaches the pump 17, and is discharged to the outside.

In the above case, the first cell 12, the second cell 13
function as a comparison cell and a measurement cell, respectively.

In this way, the first cell 12 and the second cell 1
3, sample gas SG and reference gas RG
are supplied alternately to obtain an AC signal as a measurement signal, making it possible to perform highly sensitive measurements. However, by passing the gas used as a sample gas through the reference gas purifier 16, Since this gas can be used as a reference gas, the flow rate of the sample gas SG passing through the filter 11 is halved compared to the conventional technique shown in FIG. 5, and the consumption amount of the sample gas SG can be reduced accordingly. Along with filter 1
1 dirt is reduced, and the need for inspection, replacement, etc. can be reduced. Further, as the pump 17, a pump with a small capacity can be used.

In addition, in the above-mentioned embodiment, the first gas switching section 14
and switching member 14A, 1 of second gas switching section 15
5A are coaxially arranged and rotated by a single motor 19, it is not necessary to do so. For example, two rotary valves having the same configuration may be used to connect the first gas switching unit to the first gas switching unit. 14
and a second gas switching section 15, and the switching members of both gas switching sections 14 and 15 may be electrically controlled so as to always switch in synchronization and in the same phase. That is, both the gas switching parts 14 and 15
It is only necessary that the switching of the gases in the two gases is always performed in synchronization with each other.

FIG. 3 shows a second embodiment of the present invention, in which a three-way solenoid valve is used instead of a rotary valve to constitute the first gas switching section and the second gas switching section. .

That is, as shown in the figure, between the outlet side 11b of the filter 11 and the gas inlet 12a of the first cell 12, and between the gas inlet 13a of the second cell 13 and the outlet side 16b of the reference gas purifier 16. A first gas switching section 33 is configured by three-way solenoid valves 31 and 32 provided between the gas outlet 12b of the first cell 12 and the inlet side 16a of the reference gas purifier 16, A second gas switching section 36 is constituted by three-way solenoid valves 34 and 35 provided between the gas outlet 13b of the second cell 13 and the inlet side 17a of the pump 17, respectively. between the point A between the cell 12 of cell 1 and the three-way solenoid valve 32, and between the three-way solenoid valve 32 and the second cell 1
3 and the three-way solenoid valve 31, between the three-way solenoid valve 34 and the first cell 12, the point C between the three-way solenoid valve 35, and the three-way solenoid valve 35 and the first cell 12. 2
Connecting portions 37, 38, 39, and 40 are provided between a point D between the cell 13 and the three-way solenoid valve 34, respectively.

Also in the gas analyzer configured in this way, the first gas switching section 33 and the second gas switching section 36 are switched synchronously.
The same effects as in the embodiment are achieved.

4A and 4B show a third embodiment of the present invention, and the gas analyzer in this embodiment is of a so-called single cell type.

That is, in the embodiment shown in FIGS. 4A and 4B, the second cell 13 in FIGS. 1A and 1B is removed, and the gas outlet 14d of the first gas switching section 14 and the second gas switching section 15 are The gas inlet 15b is directly connected to the gas inlet 15b, and there is no change in other configurations. In the gas analyzer configured in this way, the sample gas SG and the reference gas RG are alternately supplied to the cell 12, and in the state shown in FIG. In the state shown in FIG. B, reference gas RG is supplied to each cell 12.

It goes without saying that the gas analyzer configured in this manner also provides the same effects as the first embodiment.

In addition to the above-described embodiments, the present invention is also applicable to, for example, a double-cell type gas analyzer, in which sample gas and reference gas are alternately supplied to only one cell, and reference gas is supplied to the other cell. It can also be applied to a type in which gas is fixedly sealed.

[Effect of idea]

As explained above, the first gas switching section and the second gas switching section are provided respectively at the front stage and the rear stage of the cell to which the sample gas and reference gas according to the present invention are alternately supplied, and these gas switching parts A reference gas purifier is provided in the gas passage connecting the switching section, and the gases in the gas switching section are always switched in synchronization with each other, so that the used sample gas discharged from the cell is purified by the reference gas purifier. supplied to the Arens gas purifier,
Since the reference gas purified in the reference gas purifier is configured to be supplied to the cell, the reference gas is purified from the sample gas that has just been subjected to analysis.

In other words, in the gas analyzer according to the present invention,
Since the reference gas used for the next analysis can be obtained from the used sample gas, the fifth
Unlike the conventional gas analyzer shown in the figure, the consumption of sample gas is halved and the flow rate of sample gas through the filter is halved. Therefore, dirt on the filter is significantly reduced, inspection and replacement thereof can be reduced, and pump capacity can be reduced.

The present invention can be applied to all gas analyzers that supply sample gas and reference gas alternately (the period does not necessarily have to be constant) to the cell. It has an excellent effect of further improving the performance of this type of gas analyzer.

[Brief explanation of the drawing]

Figures 1A and B are block diagrams showing the first embodiment of the present invention, Figure 2 is an exploded perspective view showing the main parts thereof, Figure 3 is a block diagram showing the second embodiment of the present invention, and Figure 4 is a block diagram showing the second embodiment of the present invention. Figure A,
B is a block diagram showing a third embodiment of the present invention. FIG. 5 is a configuration diagram showing a conventional example. 12, 13... Cell, 14, 33... First gas switching section, 15, 36... Second gas switching section, 1
6...Reference gas purifier, SG...Sample gas, RG...Reference gas.

Claims (1)

[Scope of utility model registration request] In a gas analyzer in which a sample gas and a reference gas are alternately supplied to a cell, a first gas switching section and a second gas switching section are provided before and after the cell, respectively. A reference gas purifier is provided in the gas passage connecting the switching section, and the gases in the gas switching section are always switched in synchronization with each other, so that the used sample gas discharged from the cell is purified by the reference gas purifier. 1. A gas analyzer, characterized in that the reference gas is supplied to a reference gas purifier, and the reference gas purified in the reference gas purifier is supplied to the cell.