Thermal analysis device

Abstract

To provide a thermal analyzer capable of detecting quickly and accurately a large amount of component gas desorbed from a sample S by heating the sample S with at least a large weight of over 100 grams.SOLUTION: The thermal analyzer has a configuration to take in the outside air as a carrier gas into a carrier gas flow path. A component gas detection unit 70 includes a CO2 sensor (specific gas detection sensor) 71 for detecting CO2 gas desorbed from a sample. The component gas detection unit 70 separately includes a CO2 sensor (air-containing specific gas detection sensor) 54 for detecting CO2 gas contained in the air taken into the carrier gas flow path by a blower fan 51. The amount of CO2 gas desorbed from the sample is detected by subtracting the detected amount of CO2 gas detected by the air-containing specific gas detection sensor 54 from the detected amount of CO2 gas detected by the specific gas detection sensor 71.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermal analysis device having the function of analyzing changes in state when a sample is heated and analyzing gases desorbed from the sample due to heating. [Background technology]

[0002] In recent years, in response to the global demand for measures to combat global warming, various industrial sectors have been making efforts to reduce emissions of greenhouse gases, including CO2 (carbon dioxide), as much as possible (carbon neutrality). For example, in the cement industry, large amounts of CO2 are generated during cement manufacturing, but technological development is underway to reduce CO2 emissions into the atmosphere by absorbing the CO2 generated during manufacturing and using it in concrete (see Non-Patent Document 1).

[0003] To verify the results of technological developments that allow CO2 to be absorbed into concrete, a technique is needed to analyze how much CO2 is contained in the concrete produced. Thermal analyzers are known as analytical devices that analyze the amounts of components contained in a sample. However, conventional thermal analyzers have been developed on the premise that minute samples of about a few milligrams to a few hundred milligrams are to be analyzed, and are designed to detect about a few milligrams to a few hundred milligrams of component gases desorbed from a heated sample (see, for example, Patent Document 1).

[0004] However, the concrete for which the above-mentioned technological development is being advanced contains aggregates such as gravel and crushed stone mixed into the main ingredient, cement, so when tiny concrete particles are used as samples, the cement to aggregate mixture ratio varies greatly for each sample.As a result, the amount of desorbed gas (CO2) detected also varies from sample to sample, making it impossible to expect highly accurate qualitative analysis of desorbed gases.

[0005] Therefore, there is a need for an instrument that can perform high-precision thermal analysis on samples that are much heavier (several kilograms, for example) than those that conventional thermal analysis instruments can handle. By increasing the size of the sample, even if large solid components are randomly mixed within the sample, the overall composition ratio of the components can be made uniform, enabling high-precision qualitative analysis of desorbed gases.

[0006] On the other hand, as the sample size increases, the amount of gas desorbed from the sample also increases, making it necessary to develop a technology for analyzing the large amount of desorbed gas with high precision. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-232108 [Non-patent literature]

[0008] [Non-Patent Document 1] "Building a decarbonized society with concrete and cement!? Circulating resources and CO2 through technological innovation," [online], posted on December 15, 2021, Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry, [Retrieved August 27, 2022], Internet<URL:https: / / www.enecho.meti.go.jp / about / special / johoteikyo / concrete_cement.html> Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a thermal analysis device that can quickly and accurately detect large amounts of component gases desorbed from a sample having a weight of at least more than 100 grams by heating the sample. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a thermal analyzer comprising a heating furnace for heating a sample placed therein, a component gas detection unit for detecting component gases desorbed from the sample by heating, and a carrier gas flow path for transporting the component gases desorbed from the sample inside the heating furnace to the component gas detection unit by a carrier gas, an air intake device for taking in outside air as a carrier gas into the carrier gas flow path; a specific gas detection sensor provided in the component gas detection unit for detecting a specific component gas desorbed from the sample; an air-containing specific gas detection sensor that detects the same gas as the specific component gas that is the detection target of the specific gas detection sensor from the air taken into the carrier gas flow path by the air intake device; The amount of gas detected by the air-containing specific gas detection sensor is subtracted from the amount of gas detected by the specific gas detection sensor to determine the amount of specific component gas desorbed from the sample.

[0011] In the present invention, the carrier gas flow path is a heating furnace internal flow path having a gas supply port and a gas exhaust port, for supplying a carrier gas from the gas supply port into the heating furnace, passing through the interior of the heating furnace in which the sample is placed, and exhausting the carrier gas from the gas exhaust port; a flow path passing through the outside of the heating furnace and leading to the component gas detection unit, The gas discharge port of the flow path passing through the inside of the heating furnace is connected to the flow path passing outside the heating furnace.

[0012] The present invention also provides a heating furnace including a housing having the heating furnace installed therein, The gas supply port in the flow path passing through the inside of the heating furnace and a gas supply port for supplying a carrier gas to the flow path passing outside the heating furnace are each provided in the housing.

[0013] Furthermore, in the present invention, the flow path passing through the outside of the heating furnace is characterized by being configured to flow a carrier gas at a larger flow rate (volume or mass of gas flowing per unit time) toward the component gas detection unit compared to the flow path passing through the inside of the heating furnace.

[0014] The present invention also provides a gas flow meter for measuring the flow rate of the carrier gas flowing into the component gas detection unit; and a gas flow rate regulator for adjusting the flow rate of the carrier gas flowing into the component gas detection section.

[0015] The present invention is also characterized in that it comprises a heater for suppressing solidification of the gas conveyed from the flow path outside the heating furnace to the component gas detection section. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing the overall structure of a thermal analysis device according to an embodiment of the present invention. [Figure 2] FIG. 10 is a perspective view showing the arrangement of through holes provided in the lids of the partition cylinders. [Figure 3] FIG. 1 is a schematic diagram showing a configuration example of a thermal analysis device equipped with a gas dryer. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. This embodiment shows an example of a configuration for detecting the amount of CO2 gas desorbed from concrete that has absorbed a large amount of CO2 as an analysis target by heating the concrete. The sample S is assumed to be a large concrete mass weighing, for example, about 3 to 5 kg, but is not limited to this.

[0018] In an experiment conducted by the inventors, when a 3.5 kg concrete block was used as sample S and heated to 1000°C and maintained in this heated state, it was found that approximately 300 L of CO2 gas was desorbed from sample S. At the same time, it was also found that a large amount of H2O (water vapor) was desorbed from sample S. The thermal analysis apparatus of this embodiment is configured to quickly and accurately detect the amount of CO2 gas desorbed in large quantities from the sample S, and to suppress condensation of water vapor desorbed from the sample S within the apparatus.

[0019] FIG. 1 is a schematic diagram showing the overall structure of the thermal analysis device according to this embodiment. The thermal analysis device includes a housing 10, a heating furnace 20, a sample stage 30, and a measuring device 40. The housing 10 is a case that separates the inside and outside of the device, and a heating furnace 20 is installed in the internal space of the housing 10. The heating furnace 20 has a cylindrical heat source (heater) 21, and heats the sample S placed inside the heat source 21 from the surroundings.

[0020] Additionally, cylindrical partition wall tubes are arranged in three layers around the heating furnace 20. That is, the partition wall tubes are composed of an inner partition wall tube 22, an intermediate partition wall tube 23, and an outer partition wall tube 24, and the inner partition wall tube 22 is installed around the heating furnace 20, and the periphery of the inner partition wall tube 22 is surrounded by the intermediate partition wall tube 23, which is further surrounded by the outer partition wall tube 24. These partition wall tubes 22, 23, 24 are made of stainless steel or a heat-resistant alloy such as Fe-Cr-Al, and are provided to insulate the interior of the heating furnace 20 from heat and efficiently raise the temperature inside the heating furnace 20.

[0021] The upper end of each of the partition cylinders 22, 23, and 24 is open, and the opening is closed by a lid 22A, 23A, or 24A, which is also made of a heat-resistant alloy. Each of the lids 22A, 23A, or 24A is detachable, and the sample S can be replaced by removing the lid 22A, 23A, or 24A. Although not shown in the figure, the housing 10 is also provided with an opening / closing door for replacing the sample S.

[0022] Each lid 22A, 23A, 24A is provided with a gas delivery hole 22a, 23a, 24a, which has the function of delivering the carrier gas supplied inside the heating furnace 20 to the outside of the heating furnace 20 (the internal space of the housing 10), as described below.

[0023] The sample stage 30 has a disk-shaped sample placement section 31 formed at its upper end, and a support 32 extends downward from the center of the lower end surface of this sample placement section 31. The sample S to be analyzed is placed on the upper surface of the sample placement section 31 and placed in the center inside the heating furnace 20. The sample S is prepared by, for example, forming the concrete to be analyzed into a cylindrical block of a preset weight. A support plate 33 is formed at the lower end of the support column 32. The support column 32 is made of a material with low thermal conductivity, and prevents the heat from being transmitted to the support plate 33 even when the sample placement section 31 is heated inside the heating furnace 20. The support column 32 is supported by a bearing structure (not shown) in a manner that does not restrict its movement in the vertical direction.

[0024] Here, a thermocouple (not shown) is provided at each of the sample temperature measurement point Pa set in the sample placement section 31 and the furnace temperature measurement point Pb set at or near the heat source 21 inside the heating furnace 20, and the temperature at each temperature measurement point is measured using each of these thermocouples.

[0025] The weighing device 40 is installed below the heating furnace 20, and the support plate 33 of the sample stage 30 is mounted on the measurement section of the weighing device 40. The weighing device 40 is, for example, a weighing balance, and measures the weight of the sample S placed on the sample placement section 31 of the sample stage 30.

[0026] The measuring device 40 is disposed inside a measuring chamber 42 surrounded by a partition wall 41. An opening 41a is formed in the ceiling of the measuring chamber 42, and the measuring chamber 42 communicates with the interior of the heating furnace 20 through this opening 41a. Inside the heating furnace 20, a plurality of disk-shaped convection prevention plates 28 are arranged axially in a lower region near the opening 41a of the measuring chamber 42. The convection prevention plates 28, like the partition cylinders 22, 23, and 24, are made of a heat-resistant alloy.

[0027] A gap is formed between the outer periphery of each convection prevention plate 28 and the inner periphery of the heating furnace 20. As will be described later, the carrier gas supplied to the measuring chamber 42 flows into the interior of the heating furnace 20 through this gap.

[0028] Next, a pipe for supplying a carrier gas (gas supply pipe 50) and a pipe for discharging the carrier gas (gas discharge pipe 60) are connected to the housing 10. The hollow portions of both the gas supply pipe 50 and the gas discharge pipe 60 communicate with the internal space of the housing 10.

[0029] A component gas detection unit 70 is provided in the middle of the gas exhaust pipe 60 to detect component gases desorbed from the sample S in the heating furnace 20. A gas sensor is installed in this component gas detection unit 70, and the amount of component gases transported through the hollow part of the gas exhaust pipe 60 can be successively detected by the gas sensor.

[0030] In this embodiment, when the concrete sample S is heated, large amounts of the component gases CO and H2O (water vapor) contained in the concrete are desorbed. Therefore, the component gas detection unit 70 is provided with a CO2 sensor 71 and an H2O sensor 72 to detect the amounts of these component gases. The CO2 sensor 71 has a function of detecting CO2 contained in the carrier gas transported through the hollow portion of the gas discharge pipe 60, and successively outputting the detected amount per unit time. The H2O sensor 72 has a function of detecting H2O contained in the carrier gas transported through the hollow portion of the gas exhaust pipe 60 and successively outputting the detected amount per unit time. The H2O sensor 72 may be a humidity sensor that converts the amount of H2O into humidity and outputs the converted amount.

[0031] On the other hand, a blower fan 51 (air intake device) such as a sirocco fan is provided in the middle part of the gas supply pipe 50, and this blower fan 51 draws in outside air into the hollow part of the gas supply pipe 50, and supplies the outside air to the internal space of the housing 10 through the gas supply pipe 50.

[0032] In this embodiment, air present outside the apparatus is used as the carrier gas. As described above, when the sample S, which is concrete, is heated, a large amount of component gases (CO2 and HO) is desorbed from the sample S. To quickly transport this large amount of desorbed component gas to the component gas detection unit 70, a large amount of carrier gas is required. Generally, the carrier gas used in thermal analysis devices is an inert gas such as nitrogen gas (N2), but supplying such an inert gas in large amounts and continuously is extremely expensive. Therefore, in this embodiment, air present outside the device is used as the carrier gas, thereby realizing a thermal analysis device with low operating costs and excellent economy.

[0033] In addition, a branch pipe 52 is connected to the gas supply pipe 50. The terminal end of this branch pipe 52 is connected to the housing 10 and communicates with the inside of the measuring chamber 42. A portion of the air (carrier gas) taken into the hollow portion of the gas supply pipe 50 by the blower fan 51 is supplied to the measuring chamber 42. Here, the hollow portion of branch pipe 52 has a smaller cross-sectional area than the hollow portion of gas supply pipe 50, and the flow rate of air (carrier gas) sent to branch pipe 52 is smaller than the flow rate of air (carrier gas) flowing through gas supply pipe 50. For example, when air (carrier gas) of about 1000 L / min is taken into gas supply pipe 50, branch pipe 52 is preferably configured so that air (carrier gas) flows into it at about 5 L / min.

[0034] A flow rate adjusting valve 53 is provided in the middle of the branch pipe 52, and the flow rate of the air (carrier gas) flowing through the branch pipe 52 can be adjusted arbitrarily by this flow rate adjusting valve 53.

[0035] In this embodiment, the path from the gas supply pipe 50 to the gas exhaust pipe 60 via the internal space of the housing 10 forms a flow path A passing outside the heating furnace 20 to the component gas detection unit 70. Here, the connection portion of the gas supply pipe 50 in the housing 10 forms a gas supply port of a flow path B passing through the interior of the heating furnace. Furthermore, the path extending from branch pipe 52 through measuring chamber 42, the interior of heating furnace 20, and gas delivery holes 22a, 23a, and 24a in each of lids 22A, 23A, and 24A forms heating furnace internal flow path B. Here, the connection portion of branch pipe 52 communicating with gas supply pipe 50 in housing 10 forms a gas supply port of heating furnace internal flow path B, and gas delivery hole 24a provided in the lid closing the upper end opening of outer partition cylinder 24 forms a gas discharge port of heating furnace internal flow path B. Gas delivery hole 24a forming this gas discharge port communicates with the interior space of housing 10. That is, the gas outlet of the flow path B passing through the inside of the heating furnace is connected to the flow path A passing outside the heating furnace, and the carrier gas containing the component gas desorbed from the sample S inside the heating furnace 20 is sent from the gas delivery hole 24a (gas outlet) to the flow path A passing outside the heating furnace, where it merges with the carrier gas flowing through the flow path A passing outside the heating furnace, and flows to the component gas detection unit 70.

[0036] In this manner, in this embodiment, the flow path A passing through the outside of the heating furnace and the flow path B passing through the inside of the heating furnace form a carrier gas flow path, and the component gas desorbed from the sample S inside the heating furnace 20 is transported to the component gas detection unit 70 by the carrier gas flowing through these flow paths A and B.

[0037] Here, the furnace exterior flow path A is configured to allow a large flow rate (at least 10 L / min or more) of carrier gas to flow toward the component gas detection unit 70 in order to quickly transport the component gas desorbed in large quantities from the sample S to the component gas detection unit 70 without allowing it to stagnate. This makes it possible to quickly and accurately detect the amount of component gas desorbed from the sample S.

[0038] Furthermore, when heated, a large amount of H2O gas (water vapor) is desorbed from the concrete that is the subject of analysis in this embodiment. If this H2O gas (water vapor) remains in the internal space of the housing 10 or in the component gas detection unit 70, condensation may occur on the inner walls of the housing 10 or on the sensors 71, 72 provided in the component gas detection unit 70, which may corrode the inner walls of the housing 10 or reduce the accuracy of component gas detection by the sensors 71, 72. However, as described above, in this embodiment, the component gases desorbed in large quantities from the sample S are transported quickly to the component gas detection unit 70 through the flow path A passing outside the heating furnace without being retained, thereby avoiding the occurrence of these problems caused by condensation. For example, in the case of concrete, which is the object of analysis in this embodiment, which contains a large amount of desorbed gas, it is preferable to flow the carrier gas from the furnace exterior flow path A toward the component gas detection unit 70 at a rate of 100 L / min or more.

[0039] On the other hand, if a large flow rate of carrier gas is passed through flow path B inside the heating furnace, the inside of the heating furnace 20 will be cooled by the carrier gas, and thermal analysis using a preset temperature program may not be performed stably, which may result in failure to obtain highly accurate analytical data. Therefore, in this embodiment, the heating furnace internal flow path B is configured to allow the carrier gas to flow at a flow rate per unit time that is smaller than that of the heating furnace external flow path A. This avoids the inconvenience of the inside of the heating furnace 20 being cooled by the carrier gas, and makes it possible to stably carry out high-precision thermal analysis.

[0040] Inside the heating furnace 20, the carrier gas flowing from the measuring chamber 42 mixes with the component gases desorbed from the sample S, increasing the volume of the gas. As a result, the carrier gas containing the component gases may be forcefully ejected from the gas delivery hole 24a forming the gas outlet, which may disrupt the smooth flow of the carrier gas flowing through the furnace exterior flow path A toward the component gas detection unit 70. Therefore, in this embodiment, the gas delivery holes 22a, 23a, 24a provided in each of the lids 22A, 23A, 24A are formed at positions offset in the circumferential direction between adjacent lids (lid 22A and lid 23A, lid 23A and lid 24A) when viewed in the stacking direction of the lids, as shown in Fig. 2. As a result, the carrier gas temporarily accumulates in the space between each of the lids 22A, 23A, 24A, so that the amount of carrier gas containing component gases ejected from the gas delivery holes 24a forming the gas exhaust port is suppressed, and the carrier gas can be gently delivered into the furnace exterior flow path A.

[0041] In the structure shown in FIG. 2, each of the lids 22A, 23A, and 24A has two gas delivery holes 22a, 23a, and 24a, one on either side of the center, which are arranged at positions rotated 90 degrees from each other. However, this is not limiting, and the shape and number of the holes, or the amount of offset between the upper and lower holes, can be changed to adjust the desired amount of gas ejection.

[0042] In this embodiment, the component gas detection unit 70 is provided with a gas flow meter 73 for measuring the flow rate of the carrier gas. During adjustment work after starting up the device, the flow rate of the carrier gas flowing into the component gas detection unit 70 is measured with this gas flow meter 73, and the blower fan 51 is adjusted so that the result matches the specified flow rate. This makes it possible to repeatedly obtain thermal analysis data under the same conditions. In addition to functioning as an air intake, the blower fan 51 also functions as a gas flow rate regulator that adjusts the flow rate of the carrier gas flowing into the component gas detection unit 70.

[0043] It should be noted that even during the thermal analysis, the flow rate of the carrier gas flowing into the component gas detection unit 70 can be measured by the gas flow meter 73, and the blower fan 51 can be feedback-controlled so that the flow rate remains constant.

[0044] Furthermore, in this embodiment, a CO2 sensor 54 is also installed inside the hollow portion of the gas supply pipe 50, upstream of the connecting portion of the branch pipe 52. The CO2 sensor 71 provided in the component gas detection unit 70 functions as a specific gas detection sensor for detecting a specific component gas desorbed from the sample S. The CO2 sensor 54 installed in the hollow portion of the gas supply pipe 50 functions as an air-containing specific gas detection sensor for detecting the same gas as the specific component gas (here, CO2) that is the detection target of the specific gas detection sensor in air taken in from the outside.

[0045] In this embodiment, in which external air is used as the carrier gas, CO2, a component gas desorbed from the sample S, is also mixed into the air taken in from the outside as the carrier gas. The amount of CO2 mixed in varies depending on the CO2 concentration in the air outside the device. If the air used as the carrier gas contains the same gas (i.e., CO2) as the component gas to be detected, the CO2 sensor 71 installed in the component gas detection unit 70 will detect not only the CO2 component gas desorbed from the sample S that it is intended to detect, but also the CO2 in the carrier gas taken in from the outside, resulting in errors in the detection data.

[0046] Therefore, in this embodiment, the amount of CO2 gas desorbed from the sample S is determined without error by subtracting the amount of CO2 gas detected by the CO2 sensor 54 installed in the hollow portion of the gas supply pipe 50 from the amount of CO2 gas detected by the CO2 sensor 71 installed in the component gas detection unit 70.

[0047] In this embodiment, an HO sensor 55 is also installed in the hollow portion of the gas supply pipe 50, upstream of the connection portion of the branch pipe 52. Then, by subtracting the amount of HO gas (water vapor) detected by the HO sensor 55 installed in the hollow portion of the gas supply pipe 50 from the amount of HO gas (water vapor) detected by the HO sensor 72 provided in the component gas detection unit 70, the amount of HO gas (water vapor) desorbed from the sample S can be determined without error.

[0048] The thermal analysis apparatus having the above-described configuration takes in air as a carrier gas from the gas supply pipe 50, and supplies the carrier gas by branching it into a flow path A passing outside the heating furnace and a flow path B passing inside the heating furnace. In the heating furnace 20, the sample S (concrete) is heated, and CO2 gas is desorbed as one of the component gases desorbed from the sample S. At the same time, other component gases such as H2O gas (water vapor) contained in the sample S are also desorbed. In this embodiment, of the desorbed gases, CO2 gas and H2O gas (water vapor) are selected as specific component gases to be detected, and these component gases are detected by the CO2 sensor 71 and the H2O sensor 72 provided in the component gas detection unit 70. However, other desorbed gases may also be detected.

[0049] The component gases (CO2 gas, HO gas, etc.) desorbed from the sample S inside the heating furnace 20 are carried by the carrier gas flowing through the flow path B via the heating furnace interior, and are sent out from the gas delivery hole 24a, which is the gas outlet of the flow path, to the flow path A passing outside the heating furnace. Then, the component gases are carried to the component gas detection unit 70 by the large amount of carrier gas flowing through the flow path A passing outside the heating furnace.

[0050] Of the component gases that have reached the component gas detection unit 70, the amount of CO2 gas that is the detection target is detected by a CO2 sensor 71, and the amount of H2O gas is detected by an H2O sensor 72.

[0051] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible within the scope of the invention as defined in the claims. For example, in the above-described embodiment, air is taken in from outside the apparatus as a carrier gas, but an inert gas such as nitrogen gas can also be used as the carrier gas.

[0052] In addition, in the above-described embodiment, air (carrier gas) is supplied to the measuring chamber 42 via the branch pipe 52, but it is also possible to provide an opening in the partition wall 41 of the measuring chamber 42 and take in a portion of the air (carrier gas) supplied to the internal space of the housing 10 by the gas supply pipe 50 into the inside of the measuring chamber 42 through the opening.

[0053] In this configuration, an opening / closing window is attached to the opening provided in the partition wall 41, and the opening size can be adjusted as desired using the opening / closing window, thereby making it possible to adjust the amount of carrier gas flowing into the measuring chamber 42.

[0054] Furthermore, in the above-described embodiment, the outside air is blown in by the blower fan 51 provided in the gas supply pipe 50, but it is also possible to provide a gas suction means (air intake device) such as a blower fan or a suction pump on the gas exhaust pipe 60 side, and use the suction force to take in the outside air into the gas supply pipe 50. On the gas supply pipe 50 side, the air can be taken in using various air intake devices such as a suction pump, not limited to the blower fan 51.

[0055] In addition, in the above-described embodiment, the carrier gas flow path is configured with two paths, a flow path A passing through the outside of the heating furnace and a flow path B passing through the inside of the heating furnace. However, if the amount of gas desorbed from the sample is small, the carrier gas flow path can also be configured with a single path passing through the inside of the heating furnace.

[0056] 3, a heater 80 composed of a panel heater, an electric wire heater, an infrared heater, or the like can be installed in a necessary location, such as inside the housing 10 or the hollow portion of the gas exhaust pipe 60. This heater 80 suppresses condensation (solidification) of HO gas (water vapor) contained in the carrier gas and the desorbed gas from the sample S, thereby making it possible to avoid corrosion of the inner wall of the housing 10 and a decrease in the detection accuracy of the component gases by the sensors provided in the component gas detection unit 70. [Explanation of symbols]

[0057] 10: Housing 20: heating furnace, 21: heat source (heater), 22: inner partition cylinder, 22A: lid, 22a: gas delivery hole, 23: Intermediate partition cylinder, 23A: Lid, 23a: Gas delivery hole, 24: Outer bulkhead cylinder, 24A: Lid, 24a: Gas delivery hole, 28: Convection prevention plate, 30: sample stage, 31: sample placement section, 32: support column, 33: support plate, 40: measuring device, 41: partition wall, 41a: opening, 42: measuring room, 50: Gas supply pipe, 51: Blower fan, 52: Branch pipe, 53: Flow rate adjusting valve 54: CO2 sensor, 55: H2O sensor, 60: Gas exhaust pipe, 70: component gas detection unit, 71: CO2 sensor, 72: H2O sensor, 73: gas flow meter, 80: Heater S: sample, Pa: sample temperature measurement point, Pb: Furnace temperature measurement point, A: Fluid passage outside the heating furnace, B: Flow path through the heating furnace

Claims

1. A thermal analyzer comprising: a heating furnace for heating a sample placed therein; a component gas detection unit for detecting component gases desorbed from the sample by heating; and a carrier gas flow path for transporting the component gases desorbed from the sample inside the heating furnace to the component gas detection unit by a carrier gas, an air intake device for taking in outside air as a carrier gas into the carrier gas flow path; a specific gas detection sensor provided in the component gas detection unit for detecting a specific component gas desorbed from the sample; an air-containing specific gas detection sensor that detects the same gas as the specific component gas that is the detection target of the specific gas detection sensor from the air taken into the carrier gas flow path by the air intake device; A thermal analysis apparatus characterized in that the amount of gas detected by the air-containing specific gas detection sensor is subtracted from the amount of gas detected by the specific gas detection sensor to detect the amount of specific component gas desorbed from the sample.

2. The thermal analysis device according to claim 1, characterized in that the specific gas detection sensor and the air-containing specific gas detection sensor are both CO 2 sensors that detect CO 2 gas.

3. The carrier gas flow path is a heating furnace internal flow path having a gas supply port and a gas exhaust port, for supplying a carrier gas from the gas supply port into the heating furnace, passing through the interior of the heating furnace in which the sample is placed, and exhausting the carrier gas from the gas exhaust port; a flow path passing through the outside of the heating furnace and leading to the component gas detection unit, 2. The thermal analysis apparatus according to claim 1, wherein a gas outlet of the flow path via the inside of the heating furnace is connected to the flow path passing outside the heating furnace.

4. a housing in which the heating furnace is installed, 4. The thermal analysis apparatus according to claim 3, wherein the gas supply port in the flow path passing through the heating furnace and the gas supply port for supplying a carrier gas to the flow path passing outside the heating furnace are provided in the housing.

5. 4. The thermal analysis apparatus according to claim 3, wherein the flow path passing through the outside of the heating furnace is configured to flow a carrier gas at a larger flow rate toward the component gas detection unit than the flow path passing through the inside of the heating furnace.

6. 4. The thermal analysis apparatus according to claim 3, further comprising a heater for suppressing solidification of gas conveyed from the flow path outside the heating furnace to the component gas detection unit.

7. a gas flow meter for measuring the flow rate of the carrier gas flowing into the component gas detection unit; 7. The thermal analysis apparatus according to claim 1, further comprising a gas flow rate regulator that regulates the flow rate of the carrier gas flowing into the component gas detection section.

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