JPH053965Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a thermobalance device that performs thermogravimetric measurements, and is capable of performing gas replacement in the thermobalance container and performing good measurements in the replacement gas. This article relates to a device that makes it possible to do this.

(Prior Art) FIG. 3 shows a conventional example of a thermobalance device that enables thermogravimetric measurement in replacement gas.

2 is a thermobalance container which accommodates a balance 4. A sample plate on which a sample 6 is placed is suspended from one end of the balance 4, and a plate on which a weight 8 is placed is suspended from the other end to maintain balance.

A reaction tube consisting of an upper reaction tube 10 and a lower reaction tube 12 is provided on the side of the balance container 2 from which the sample 6 is suspended, and the sample 6 is provided in the lower reaction tube 12. A heating furnace (not shown) is provided around the lower reaction tube 12. The upper reaction tube 10 is provided with an inlet 14 for replacing gas, and the introduced replacing gas is supplied onto the sample 6 through an internal tube 16 and is discharged from an exhaust tube 18. The replacement gas discharged from the exhaust pipe 18 also contains the decomposed gas generated from the heated sample 6, and this decomposed gas can be led together with the replacement gas to a gas chromatograph or mass spectrometer for analysis.

20 is a thermocouple, which measures the sample temperature.

A vacuum pump 22 used for gas replacement is also connected to the thermobalance container 2 via a stop valve 24. In addition, 26 is the upper reaction tube 10
28 is an O-ring that seals the weight side of the thermobalance container 2.

In this thermobalance device, to perform gas replacement, the replacement gas inlet 14 and exhaust port 18 are closed, the stop valve 24 is opened, and the inside of the thermobalance container 2 is evacuated by the vacuum pump 22, and then the stop valve 24 is closed. After the replacement gas is introduced from the inlet 14 to fill the thermobalance container 2 with the replacement gas, the outlet 18 is opened.

(Problem to be solved by the invention) When the vacuum pump 22 performs evacuation, the sample 6
A rapid upward flow of gas from downstream to upstream occurs with respect to the sample plate on which the sample plate is placed, and this upward flow may cause the sample plate to come off.

Furthermore, even after gas replacement is completed and measurement is started while gas is introduced from the inlet 14 and discharged from the outlet 18, the downstream side of the outlet 18 can be If a pressure fluctuation occurs or if it is closed, the pressure inside the thermobalance device will increase and the thermobalance container 2
Otherwise, the reaction tubes 10 and 12 may be damaged.

The present invention reduces the exhaust speed during gas replacement to prevent the sample dish from coming off due to upward flow, and also prevents the sample dish from coming off due to the upward flow. The purpose of the present invention is to provide a displacement gas control device that can prevent accidents such as damage to the gas.

(Means for Solving the Problems) The displacement gas control device of the present invention will be explained with reference to FIG. 1 showing one embodiment. The reaction tube 10 includes an inner tube 16 for introducing a displacement gas onto the sample.
is installed in the thermobalance device, which has a replacement gas inlet 30 above the reaction tube 10 and a replacement gas outlet 18 below the reaction tube 10. Means for suppressing pressure rise 4
A vacuum pump 22 is connected via a stop valve 24 and an orifice 46, and a splitter 4 is provided at a position upstream of the sample 6 of the reaction tube 10 and downstream of the upper end of the internal tube 16.
2 is provided.

In the present invention, the terms "upstream" and "downstream" mean "upstream" and "downstream" from the position of the sample 6 with respect to the flow path of the replacement gas.

(Function) During gas replacement, the gas from the thermobalance device is exhausted at a low speed through the orifice 46, so that no rapid upward flow occurs around the sample plate on which the sample 6 is placed.

If the pressure inside the thermobalance device increases, use means 4.
0 suppresses pressure rise.

Further, on the outside of the inner tube 16, a flow of replacement gas is generated toward the splitter 42 via the upper end 16a of the inner tube 16. Even if the decomposition gas generated from the sample 6 rises outside the inner tube 16, it will be discharged from the splitter 42 together with the displacement gas flow and will not flow back into the inner tube 16.

(Embodiment) FIG. 1 shows an embodiment of the present invention. The same parts as in Figure 3 are given the same symbols.

A gas inlet 30 is provided on the side surface of the balance container 2 housing the balance 4, and one of two types of replacement gases is introduced into the gas inlet 30 via a three-way branch pipe 32. . The two types of replacement gases are, for example, helium and air.

At the lower part of the sample side of the balance container 2, an upper reaction tube 10 is sealed with an O-ring 26 and attached as shown in FIG. It is attached. An inner tube 16 is located at the center of both reaction tubes 10 and 12.
A sample plate is suspended below the inner tube 16, and a sample is placed on the sample plate. The thermocouple 20 passes through a hole at the lower end of the upper reaction tube 10 and is taken out from the thermocouple outlet 11 of the upper reaction tube 10. A discharge port 18 is provided at the lower end of the lower reaction tube 12 to take out the cracked gas together with the replacement gas.

The upper reaction tube 10 is provided with an outlet 34 through which gas flows out from the upper reaction tube 10 . The gas outlet 34 is located downstream of the upper end 16a of the internal tube 16 and upstream of the sample 6. A four-way branch pipe 3 is connected to the gas outlet 34 via a hose 36.
8 is attached, and the four-way branch pipe 38 is provided with a splitter 42 and piping 44 in addition to a relief valve 40 as a means for suppressing pressure rise.

The piping 44 has a stop valve 24 and an orifice 4.
A vacuum pump 22 is connected via 6. 4
8 is a hose.

The relief valve 40 has a structure in which a ball is pressed against the outlet by a spring, and the relief valve 40 has a structure in which a ball is pressed against the outlet by a spring.
It is set to open when the pressure reaches 0.3Kg/ ^cm2 .

Splitter 42 is a resistance tube.

Further, it is suitable for the orifice 46 to have an inner diameter of about 1 mm, for example.

Next, how to use this embodiment will be explained.

After closing the two gas inlets for supplying gas to the three-way branch pipe 32 and the passage downstream of the lower reaction tube 12, the stop valve 24 is fully opened and the balance vessel 2, upper reaction tube 10, and lower reaction tube 12 are opened. Exhaust the inside. When the sound of the vacuum pump 22 becomes low and exhaust is completed,
Gas is allowed to flow in from either gas inlet of the three-way branch pipe 32, and the stop valve 24 is fully closed. When the pressure gauge 33 stops rising and gas flows out from the relief valve 40, the passage downstream of the lower reaction tube 12 is opened to allow gas to flow around the sample dish. This completes the preparation for thermal analysis.

In this embodiment, the relief valve 40 is provided as a means for suppressing pressure rise, so that the pressure inside the reaction tubes 10 and 12 is not affected by downstream conditions.
Further, since the relief valve 40 is configured to operate at a pressure that is not significantly different from atmospheric pressure, thermal analysis can be performed under conditions close to atmospheric pressure even if downstream conditions change.

Furthermore, since the relief valve 40, splitter 42, and vacuum pump 22 are attached to one location of the upper reaction tube 10 via the four-way branch pipe 38, the apparatus becomes simple.

FIG. 2 represents another embodiment.

In the embodiment shown in FIG. 1, a relief valve 40 is provided as a means for suppressing pressure rise, whereas in this embodiment, a rubber balloon 52 is provided via a clip 50.

In order to perform gas replacement in this embodiment, after closing the rubber balloon 52 with the clip 50, two gas inlets are opened to supply gas to the three-way branch pipe 32 as in the embodiment of FIG. The downstream passage of the lower reaction tube 12 is closed, and the stop valve 24 is fully opened. When the exhaust is completed, gas is allowed to flow into either of the three-way branch pipes 32, the stop valve 24 is fully closed, and the clip 50 is removed. Once the rubber balloon 52 is inflated, the downstream passage of the lower reaction tube 12 is opened to allow gas to flow around the sample pan.

(Effects of the invention) According to the invention, the following effects can be achieved.

(1) Since a means to suppress pressure rise is provided, the thermobalance container can be kept safe even if the pressure on the downstream side fluctuates or the flow path is closed.

(2) Since exhaust during gas replacement is performed through an orifice, a sudden upward flow is not generated around the sample dish, and gas replacement can be performed safely.

(3) A splitter is installed upstream of the sample and downstream of the upper end of the internal tube, which prevents the decomposed gas generated by the sample from flowing backwards and into the internal tube, making it possible to analyze the decomposed gas. If this is done, the analysis can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a thermobalance device equipped with an embodiment of the present invention, FIG. 2 is a schematic sectional view showing a thermobalance device equipped with another embodiment of the present invention, and FIG. 3 is a conventional FIG. 2 is a schematic cross-sectional view showing a thermobalance device. 6... Sample, 10... Upper reaction tube, 12... Lower reaction tube, 16... Inner tube, 16a... Upper end of inner tube, 18... Outlet, 24... Stop valve, 22
...Vacuum pump, 30...Gas inlet, 40...
Relief valve, 42... splitter, 46... orifice.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A sample suspended from a hanging balance is housed in a reaction tube, and this reaction tube is provided with an internal tube that guides replacement gas onto the sample. A thermobalance device has a replacement gas inlet above the tube and a replacement gas outlet below the reaction tube.
A means is provided that does not operate at atmospheric pressure and suppresses a pressure increase above a certain pressure, and a vacuum pump is connected via a stop valve and an orifice, and is located upstream of the sample in the reaction tube and inside the reaction tube. A displacement gas control device for a thermobalance device, characterized in that a splitter is provided at a position downstream from the upper end of a tube. (2) The replacement gas control device for a thermobalance device according to claim 1, wherein the means for suppressing the pressure increase is a relief valve.