JPS62185142A - Analysis gas trapper - Google Patents

Abstract

PURPOSE:To obtain a gas trapper which enable a simple and accurate quantitative analysis, by arranging a decomposition container and a gas trapping container made to communicate therewith. CONSTITUTION:Firstly, for example, about 0.3g of a sample 1 of carbon fiber reinforced aluminum is put into a decomposition container 4, 6N hydrochloric acid injected therein to as a decomposing liquid 2 while a plunger 14 of the gas trapping container 9 is moved downward. Then, the container 4 is heated with a heater 5 to decompose the sample 1 completely. A gas generated is cooled with a cooling tube 7, and flows into a trapping container 9 through a hole 11 at a cylinder section 10 via a cock 13 at an opening position passing through a glass tube 6. After the melting of the sample 1, the unit 5 is removed, the heating is stopped and the container 4 is water cooled to be returned to a room temperature. Then, the cock 13 is closed. Under such a condition, the entire container 9 is removed from a link section 8 of the tube 6, made horizontal to measure the volume of the gas and then, the concentration of methane in the gas being trapped is measured by a gas chlomatograph. Finally, the content amount of aluminum carbide is calculated by a specified formula.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an analysis gas collection device.

[Prior Art] Conventionally, the water displacement method (JIS K1901), mercury displacement method, and activated carbon collection have been used as gas collection methods for determining specific components in an analysis sample from the gas generated by decomposing the analysis sample. The law is known.

[Same problem to be solved by the invention] In the water displacement method, depending on the gas to be measured, it may be absorbed by water, resulting in errors. The mercury replacement method uses mercury, which is a poisonous substance, and is not sanitary. Furthermore, the activated carbon collection method requires complicated operations such as handling of liquid nitrogen.

It is an object of the present invention to provide a gas trapping tjA device that does not have the above-mentioned problems and is capable of simple and accurate constant a analysis.

[Structure of the Invention] (Means for Solving the Problems) The analytical gas collection device of the present invention includes a sealed decomposition container that accommodates an analytical sample and a decomposition liquid for decomposing the sample;
It is characterized by comprising a gas collection container communicating with the decomposition container and whose interior is maintained at a negative pressure state.

In the present invention, the structure of the device as a whole is much more medium-sized than conventional analytical gas collection devices, and the inside of the collection container is maintained at negative pressure, allowing the generated gas to escape to the outside. do not have. This results in high analysis accuracy.

(Detailed Description of the Structure of the Invention) The present invention basically comprises a sample decomposition means and a generated gas collection means.

The analytical sample to be determined may be any type as long as it can be quantitatively analyzed based on the type and amount of gas generated. As an example, the quantitative analysis of aluminum carbide or calcium carbide will be explained here. In this case, it is desirable to use 6N or higher hydrochloric acid as the sample decomposition solution in order to promote decomposition and shorten the time required for quantitative determination. A variable volume container for mixing the gas in the decomposition container and the gas collection container can be connected to the decomposition container.

The construction and arrangement of the variable volume vessel may be the same or similar to the gas collection vessel.

The gas collection vessel is placed in close proximity to the decomposition vessel and is in communication with the decomposition vessel by a gas guiding or guiding portion, such as a glass tube or tube portion.

The gas collection container is composed of a cylinder part as an outer part and a plunger part as an inner cylinder, and the plunger part is movably inserted into the cylinder with the withdrawal direction facing downward. In other words, the cylinder part and the plunger part need to have an airtight structure. For example, when the cylinder part is suspended, the plunger part rubs against the inner circumferential surface of the cylinder part at a very slow speed. It is preferable that they fit together to such an extent that they will fall into place. If necessary, the gap between the cylinder portion and a portion of the first lange may be sealed with a sealing material.

The bottom (closed side) of the cylinder of the gas collection container is provided with a step hole for the inflow of gas, the size of which is approximately equal to the inner diameter of the guiding glass tube. A connecting tube for connection is provided protrudingly, and a cock is provided near the tip of the connecting tube to stop the inflow of gas.

[Embodiments of the Invention] (First Actual Flow Example) A first embodiment of the analysis gas collection device according to the present invention is schematically shown in FIG. As for the analysis sample, as mentioned above, any sample can be used as long as it can be analyzed at a constant rate depending on the type of gas generated and the opening, but here, as an example, CFRAL (carbon fiber reinforced aluminum) containing aluminum carbide It was used as a sample. A decomposition container 4 in which a sample 1 of 6N or more and a decomposition liquid 2 containing hydrochloric acid are sealed with a rubber stopper 3
is housed within. As the heating device 5 for heating the sample 1 and the decomposition liquid 2 to completely dissolve or decompose the sample 1, a conventionally known stirrer heater, Bunsen burner, etc. can be used.

One end of a gas tube 6 was inserted into the decomposition vessel 4 to introduce or guide the generated gas to a gas collection vessel (described later). A water-cooled cooling pipe 7 for cooling the generated gas is integrally provided in the glass duplex 6, and the other end 8 of the glass tube 6 is provided at the bottom of a cylinder 10 that forms the outer cylinder of the gas collection container 9. It is made to be airtightly connected to a connecting cylinder part 12 protruding from a hole for gas circulation. The inflow of gas into the gas collection container is controlled by a cock 13.

The plunger portion 14 was set in the cylinder 10 with its pulling direction facing downward. The gas that has flowed into the gas collection container in this way is transferred to the bottom of the cylinder 10 and the plunger 1.
It was made to accumulate in the space between the top surfaces of 4.

Since the plunger 14 is disposed with its withdrawal direction facing downward, the pressure inside the collection container is always maintained at negative pressure or reduced pressure. By the way, by maintaining negative pressure or reduced pressure, air flows from the inlet to the container, contrary to pressurization, which lowers the concentration of methane gas in the container, but the gas does not flow out from the container. , the absolute value of methane does not change, making accurate measurement possible. A scale 15 is provided on the outer wall of the cylinder 10, with an error of ±3
Scaled intervals within %.

Next, the operation of the embodiment will be explained according to the analytical gas collection operation procedure.

First, approximately 0.3G of CFRAL (carbon fiber reinforced aluminum) sample 1 was weighed into the decomposition container 4, and 6N hydrochloric acid was injected as the decomposition liquid 2, while the plunger 14 of the gas collection container 9 was moved downward. . Next, the container 4 was heated with the heating device 5 to completely decompose sample 1311. The generated gas is cooled by the cooling pipe 7 and passes through the glass tube 6.
It flowed into the collection container 9 from the hole 11 of the cylinder portion 10 through the cock 13 located at the σl position.

After dissolving sample 1 (approximately 10
minutes), the heating device 5 was removed to stop heating, the decomposition vessel 4 was cooled with water to return to room temperature, and the cock 13 was turned off to rMl. In this state, the entire gas collection container 9 is connected to the connecting portion 8 of the glass tube 6.
The gas volume was measured with the container held horizontally, and then the methane concentration in the collected gas was measured using a gas chromatograph. As a final step, the aluminum carbide-containing skewer was prepared according to the given formula.

(Second Embodiment) A second embodiment of the analytical gas collection device of the present invention is shown in FIG. In this embodiment, a variable volume container 16 is added to the decomposition container 1. 17, a plunger 18 forming an inner cylinder, a glass tube 19 communicating with the decomposition container 4, and a cock 20 controlling the inflow of air.

When the cock 20 is closed and the plunger 18 is pushed up, air passes through the decomposition container 4 - the glass tube 6 and into the gas collection container 9.
The gases in the decomposition vessel 4 and the gas collection vessel 9 were mixed together.

[Effects of the Invention] The analysis gas collection device according to the present invention has a simpler overall structure than any of the devices in the conventionally known methods.

Furthermore, it is easy to operate, does not require the use of toxic substances that are undesirable from a sanitary standpoint, and because the inside of the gas collection container is always maintained at negative pressure or reduced pressure, the generated gas does not escape to the outside. This results in higher analytical accuracy and a highly accurate determination a.
It has a great practical effect in that it can be done in a short time!
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[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a first embodiment of the device according to the present invention;
FIG. 2 is a schematic explanatory diagram of a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sample 2... Decomposition liquid 4... Decomposition container 9... Gas collection container 10... Cylinder part 14... Plunger part 16... Variable volume container 17... Cylinder Part 18...Plunger part

Claims (4)

[Claims] (1) It consists of a sealed decomposition container that contains an analysis sample and a decomposition liquid for decomposing the sample, and a gas collection container that communicates with the decomposition container and whose interior is maintained at a negative pressure state. Characteristic analysis gas collection device. (2) The analytical gas collection device according to claim 1, wherein the analytical sample is a sample containing aluminum carbide or calcium carbide, and the decomposition liquid is hydrochloric acid of 6N or more. (3) The gas collection container includes a cylinder portion forming an outer cylinder;
The analysis gas collection device according to claim 1, comprising a plunger portion forming an inner cylinder and having a downward drawing direction. (4) The analysis gas collection device according to claim 1, wherein the decomposition container has a variable volume container for mixing the gas in the decomposition container and the gas collection container.