JPS6041733B2 - Standard gas preparation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for preparing a standard gas used for calibrating a gas analyzer using a quantitative generator or a gas diluter.

Conventionally, when changing the concentration of raw material gas generated by a self-quantification generator such as an ultraviolet irradiation ozone generator or a permeation tube for calibrating an analyzer, it is necessary to change the concentration, current, (light intensity or surface area). ) It is adjusted by shielding etc. and the flow rate of diluent gas.

However, these conventional means lack the simplicity and speed of adjusting the concentration required for the calibration gas, and because the dilution gas flow rate is changed, it is difficult to match the required flow rate with the generated flow rate. Furthermore, in order to improve performance such as accuracy and responsiveness, conventional gas dilution devices overflow a portion of the gas, resulting in a lot of waste.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a device having various advantages such as being able to easily and quickly adjust the concentration and eliminating waste of dilution gas. There is.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a diluent gas (e.g. Os, Nα, H
.

The inlet (2) of purified air from which O, HC, etc. have been removed is a dilution gas flow path, and its downstream side is branched into a first flow path 3 and a second flow path 4. Reference numeral 5 denotes a third flow path connecting the first and second flow paths 3 and 4, and this third flow path 5 includes a plurality of capillary flow resistances 6, . They have the same structure and size.

) are connected at one end of each, and furthermore, the connection point 71
5, one end of each of a plurality of discharge channels 81 to 6 arranged in parallel is connected to the third channel 5 so as to be different from each other. (The connection points are indicated by 91 to 6.) The other end of each of these discharge channels 81 to 5 is connected to the division valve 1.
0 to the return flow path 11, and the dividing valve 1
By switching 0, one of the discharge channels 81 to 6,
It is designed to be able to communicate with the return flow path 11. Reference numeral 12 denotes a generated gas flow path, and the other ends of each of the capillary flow resistances 61 to 5 are connected to the generated gas flow path 12. It is connected to. Reference numeral 13 denotes a flow rate regulator for gas concentration adjustment provided in the first flow path 3;
The concentration of generated gas is adjusted by changing the flow rate of diluent gas flowing through it.

14 is a quantitative generator (for example, an ultraviolet irradiation ozone generator, a permeation tube, a permeation membrane, an electrolytic method 02/H2 generator, etc.) provided in the first flow path 3, and the unit is Generates a certain amount of component gas per hour.

Therefore, in the first flow path 3, on the downstream side of the quantitative generator 14, a mixed gas of the generated gas and the diluent gas flows. Reference numeral 15 denotes a differential pressure regulator provided in the second flow path 4, which maintains the differential pressure between the inlet side and the outlet side of the capillary flow resistances 61 to 5 at a predetermined constant pressure, and controls the generated gas flow path 1.
It functions to keep the flow rate V of the generated gas flowing through 2 at a constant amount.

16 is a flow meter provided in the third flow path 5; 17 is a flow rate adjusting element (eg, a needle valve, a capillary flow resistance, etc.) provided in the return flow path 11;

fixed or semi-fixed), and the flow rate regulator 13 is closed (fixed or semi-fixed).
With the flow rate set to 0), adjust the flow rate adjustment element 17 while watching the flow meter 16 so that a predetermined amount of gas flows into the generated gas flow path 12. 18 is a scrubber provided in the return flow path 11, and functions to remove component gas flowing through the return flow path 11 from among the component gases generated by the quantitative generator 14.

This scrubber uses activated carbon (component gas is 03, S02
), a molecular sieve (when the component gas is SO2) is used.

Therefore, the dilution gas is supplied from the dilution gas inlet 1, and
The quantitative generator 14 is operated to supply a mixed gas of dilution gas and generated gas from the first flow path 3 side and dilution gas from the second flow path 4 side to the third flow path 5, respectively. , the generated gas having a desired concentration (variable) is made to flow through the generated gas flow path 12 at a predetermined flow rate.

At this time, for example, as shown in the figure, the split valve 10
When the switching cock (not shown) is operated to connect the discharge passage 83 and the return passage 11, the mixed gas and diluent gas flow in the direction of the arrow in the diagram, and only the capillary flow resistances 61 and 2 are allowed to flow. A mixed gas flows through the A portion of each of the dilution gas and the mixed gas flows through the return flow path 11 via the division valve 10, and component gases in the mixed gas are removed by the scrubber 18. Next, a manifold (branch pipe) 19 is connected to the generated gas flow path 12, and a manifold (branch pipe) 19 is connected to the generated gas flow path 12.
The flow is divided into routes 20 and 21.

The generated gas branched into one path 20 is further branched into an analyzer 22 for calibration and a gas analyzer 23 for instantaneous monitoring.
, to the overflow gas outlet 24. The generated gas diverted to the other path 21 is sent to an analyzer 26 for manual analysis (for integration monitoring) via a three-way solenoid valve 25.
Further, the generated gas in this path 21 can also be made to flow in the direction shown by the dashed arrow a by switching the three-way solenoid valve 25.

This is done when the instantaneous monitoring analyzer 23 is used to check the concentration change that may occur when the flow is divided by the first manifold 19, and when there is insufficient gas flowing into the second instantaneous monitoring analyzer 23. . In addition, in the figure, 2
7, 28 are three-way solenoid valves, 29 is check gas inlet, 30
is a check gas overflow outlet, 31 is an overflow monitor (for example, a rotor type flow meter, etc.) 32, 33
is a capillary flow resistance, 34 is a concentration division part, and 35 is a distribution part.

The present invention has the above-described configuration, and can easily and quickly obtain generated gas at a desired concentration at a constant flow rate by operating the switching cock of the division valve and/or by operating the flow rate regulator. It can be suitably used as a standard gas for calibration of gas analyzers.

Furthermore, since a return flow path is provided between the discharge flow path and the generated gas flow path, and a scrubber is provided in the return flow path, the dilution gas is not wasted and is economical.

[Brief explanation of the drawing]

The drawings are explanatory diagrams showing one embodiment of the present invention. 2... Dilution gas flow path, 3... First flow path, 4... Second flow path, 5... Third flow path, 61-5... Capillary flow resistance, 81-6. ...Discharge flow path, 10...dividing valve,
11... Return flow path, 12... Generated gas flow path, 13.
...Flow rate regulator, 14...Quantity generator, 15...Differential pressure regulator, 18...Scrubber.

Claims (1)

[Claims] 1. Branching the diluent gas flow path into a first and second flow path, and providing a third flow path that connects the first flow path and the second flow path,
One end of each of a plurality of capillary flow resistances is connected in parallel to the third flow path, and one end of each of a plurality of discharge flow paths is connected in parallel to the third flow path so as to be different from each other with respect to the connection point. connected to the third flow path, and the other end of each discharge flow path is connected to a return flow path via a split valve, the return flow path being communicated with the generated gas flow path; The other end of each of the flow resistances is connected to a generated gas flow path, the first flow path is further provided with a quantitative generator and a flow rate regulator for gas concentration adjustment, and the second flow path is connected to the capillary flow rate. A differential pressure regulator is installed to keep the differential pressure between the inlet and outlet sides of the resistor constant.
A standard gas regulating device including a scrubber in the return flow path.