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 includes: a heating furnace internal flow path B that is formed to pass through inside a heating furnace 20 that heats a sample S; and a heating furnace external flow path A that is formed to pass outside the heating furnace 20, and a carrier gas is supplied to the flow paths. The carrier gas (including desorption gas from the sample S) flowing through the heating furnace internal flow path B is sent to the heating furnace external flow path A in which a large amount of carrier gas flows, and carried to a component gas detection unit 70.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a thermal analyzer having a function of analyzing a state change when a sample is heated and analyzing a gas desorbed from the sample by heating.

Background Art

[0002] In recent years, in response to the demand for global warming countermeasures, efforts (carbon neutrality) have been made in various industrial fields to reduce the emissions of greenhouse gases such as CO2 (carbon dioxide) as much as possible. For example, in the cement industry, a large amount of CO2 is generated during the production of cement. Technical development is underway to reduce the amount of CO2 emitted into the atmosphere by absorbing the CO2 generated during production and using it in concrete (see Non-Patent Document 1).

[0003] Here, in order to verify the results of the technical development of absorbing CO2 in concrete, a technique for analyzing how much CO2 is contained in the produced concrete is required. As an analyzer for analyzing the component amounts contained in a sample, a thermal analyzer is known. However, conventional thermal analyzers have been developed on the premise that a minute sample of about several milligrams to several hundred milligrams is the analysis target, and are designed to detect component gases of about several milligrams to several hundred milligrams desorbed from the heated sample (for example, see Patent Document 1).

[0004] However, since the concrete in which the above technical development is underway contains aggregates such as gravel and crushed stone mixed in the cement as the main raw material, when minute concrete is used as a sample, the mixing ratio of cement and aggregates varies greatly for each sample. As a result, the amount of desorbed gas (CO2) detected also varies for each sample, and high-precision qualitative analysis of the desorbed gas cannot be expected.

[0005] Therefore, there is a need for the development of a device that can perform highly accurate thermal analysis on samples that weigh significantly more (for example, several kilograms) than those targeted by conventional thermal analysis devices. By increasing the sample size, even if large solid particles are randomly mixed inside the sample, the overall composition ratio of the components becomes more uniform, enabling highly accurate qualitative analysis of desorbed gases.

[0006] On the other hand, as the sample size increases, the amount of gas desorbed from the sample inevitably increases, making it necessary to develop techniques for highly accurate analysis of this large amount of desorbed gas. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication 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], published December 15, 2021, Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry, [Accessed August 27, 2022], Internet<URL:https: / / www.enecho.meti.go.jp / about / special / johoteikyo / concrete_cement.html> [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the above circumstances, and aims to provide a thermal analyzer that can rapidly and accurately detect a large amount of component gases desorbed from a sample by heating the sample, which weighs at least 100 grams or more. [Means for solving the problem]

[0010] To achieve the above objective, the present invention provides a thermal analyzer comprising a heating furnace for heating a sample placed inside, 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 using a carrier gas, The carrier gas flow path is A heating furnace-through flow path having a gas supply port and a gas discharge port, wherein a carrier gas is supplied from the gas supply port into the heating furnace, and the carrier gas is discharged from the gas discharge port after passing through the inside of the heating furnace where the sample is placed, It includes a heating furnace external passage that passes outside the heating furnace and leads to the component gas detection unit, Furthermore, the gas outlet of the flow path through the heating furnace is connected to the flow path passing outside the heating furnace.

[0011] Furthermore, the present invention includes a housing in which the heating furnace is installed inside, The housing is characterized by providing both the gas supply port in the flow path through the heating furnace and the gas supply port for supplying carrier gas to the flow path passing outside the heating furnace.

[0012] Furthermore, the present invention is characterized by comprising an air intake device that takes in external air as a carrier gas into the carrier gas flow path.

[0013] Furthermore, in the present invention, the external flow path of the heating furnace is configured to flow a carrier gas with a larger flow rate (volume or mass of gas flowing per unit time) toward the component gas detection unit compared to the internal flow path of the heating furnace.

[0014] Furthermore, the present invention includes a gas flowmeter for measuring the flow velocity of the carrier gas flowing into the component gas detection unit, The system is characterized by comprising a gas flow rate regulator that adjusts the flow rate of the carrier gas flowing into the component gas detection unit.

[0015] The present invention is further characterized by including a heater for suppressing the condensation of the gas conveyed from the external passage flow path of the heating furnace to the component gas detection unit.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram showing the overall structure of a thermal analysis apparatus according to an embodiment of the present invention. [Figure 2] It is a perspective view showing the arrangement of through holes provided in the lid of each partition cylinder. [Figure 3] It is a schematic diagram showing a configuration example of a thermal analysis apparatus provided with a gas dryer.

Embodiments for Carrying Out the Invention

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

[0018] In the experiments of the present inventors, when a 3.5 kg concrete block was used as the sample S and heated up to 1000 °C and the overheated state was continued, it was found that about 300 L of CO2 gas desorbed from the sample S. At the same time, it was also found that a large amount of H2O (water vapor) desorbed from the sample S. The thermal analysis apparatus of this embodiment is configured to be able to quickly and accurately detect the amount of CO2 gas desorbing in large quantities from the sample S, and to suppress the condensation of the water vapor desorbed from the sample S inside the apparatus.

[0019] FIG. 1 is a schematic diagram showing the overall structure of the thermal analysis apparatus according to this embodiment. The thermal analysis apparatus includes a housing 10, a heating furnace 20, a sample stage 30, and a measuring instrument 40. The housing 10 is a casing that separates the inside and outside of the device, and the heating furnace 20 is installed in the internal space of this 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] Furthermore, a triple layer of cylindrical partition walls surrounds the heating furnace 20. Specifically, the partition walls consist of an inner partition wall 22, a medium-spaced wall 23, and an outer partition wall 24. The inner partition wall 22 is installed around the heating furnace 20, the inner partition wall 22 is surrounded by the medium-spaced wall 23, and the medium-spaced wall 23 is further surrounded by the outer partition wall 24. Each of these partition walls 22, 23, and 24 is made of stainless steel or a heat-resistant alloy such as Fe-Cr-Al, and is provided to block heat from the heating furnace 20 and efficiently raise the temperature inside the heating furnace 20.

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

[0022] Each lid 22A, 23A, and 24A is provided with gas outlets 22a, 23a, and 24a, respectively. These gas outlets 22a, 23a, and 24a have the function of sending the carrier gas supplied to the inside of the heating furnace 20 to the outside of the heating furnace 20 (the internal space of the housing 10), as will be described later.

[0023] The sample stage 30 has a disc-shaped sample placement section 31 formed at its upper end, and a support column 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 positioned in the center of the inside of the heating furnace 20. Sample S is prepared, for example, by shaping the concrete to be analyzed into a cylindrical mass of a predetermined 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, so that even when the sample placement section 31 is heated in the heating furnace 20, the heat is not transmitted to the support plate 33. The support column 32 is supported by a bearing structure (not shown) in a manner that does not restrict vertical movement.

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

[0025] The weighing instrument 40 is installed below the heating furnace 20, and the support plate 33 for the sample stage 30 is mounted on the measuring section of the weighing instrument 40. For example, a weighing balance is used in the weighing instrument 40 to measure the weight of the sample S placed on the sample placement section 31 of the sample stage 30.

[0026] The weighing device 40 is located inside a weighing chamber 42 surrounded by partition walls 41. An opening 41a is formed in the ceiling of the weighing chamber 42, and the weighing chamber 42 communicates with the inside of the heating furnace 20 through this opening 41a. Inside the heating furnace 20, multiple disc-shaped convection prevention plates 28 are arranged axially in the lower region near the opening 41a of the weighing chamber 42. The convection prevention plates 28 are also made of a heat-resistant alloy, similar to the partition cylinders 22, 23, and 24.

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

[0028] Next, the housing 10 is connected to a piping system for supplying carrier gas (gas supply pipe 50) and a piping system for discharging carrier gas (gas discharge pipe 60). Both the gas supply pipe 50 and the gas discharge pipe 60 have hollow sections that communicate with the internal space of the housing 10.

[0029] A component gas detection unit 70 is provided in the middle section of the gas discharge pipe 60 for detecting component gases that have been released 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 gas transported through the hollow section of the gas discharge pipe 60 can be sequentially detected by the gas sensor.

[0030] In this embodiment, when the concrete sample S is heated, a large amount of CO2 and H2O (water vapor) component gases contained in the concrete are released. Therefore, the component gas detection unit 70 is equipped with a CO2 sensor 71 and an H2O sensor 72 to detect the amount of these component gases. The CO2 sensor 71 has the function of detecting CO2 contained in the carrier gas that has been transported through the hollow section of the gas discharge pipe 60 and sequentially outputting the amount detected per unit time. Furthermore, the H2O sensor 72 has the function of detecting H2O contained in the carrier gas that has been transported through the hollow section of the gas discharge pipe 60 and sequentially outputting the amount detected per unit time. This H2O sensor 72 may also be a humidity sensor that converts the amount of H2O into humidity and outputs it.

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

[0032] In this embodiment, air present outside the device is used as the carrier gas. As previously described, when the concrete sample S is heated, a large amount of component gases (CO2 and H2O) are released from the sample S. To quickly transport this large amount of released component gas to the component gas detection unit 70, a large amount of carrier gas is required. Generally, the carrier gas used in thermal analyzers is an inert gas such as nitrogen gas (N2), but supplying such an inert gas in large quantities and continuously requires extremely high costs. Therefore, in this embodiment, by using air present outside the device as the carrier gas, a thermal analyzer with low operating costs and excellent economic performance has been realized.

[0033] Furthermore, a branch pipe 52 is connected to the gas supply pipe 50. The end of this branch pipe 52 is connected to the housing 10 and communicates with the inside of the metering chamber 42. Air (carrier gas) drawn into the hollow section of the gas supply pipe 50 by the blower fan 51 is partially supplied to the metering chamber 42. Here, the hollow section of the branch pipe 52 has a smaller cross-sectional area than the hollow section of the gas supply pipe 50, and the flow rate of air (carrier gas) supplied to the branch pipe 52 is less than the flow rate of air (carrier gas) flowing through the gas supply pipe 50. For example, when approximately 1000 L / min of air (carrier gas) is taken into the gas supply pipe 50, it is preferable to have a structure in which approximately 5 L / min of air (carrier gas) flows into the branch pipe 52.

[0034] Furthermore, a flow control valve 53 is provided in the middle section of the branch pipe 52, and this flow control valve 53 allows the flow rate of air (carrier gas) flowing through the branch pipe 52 to be adjusted as desired.

[0035] In this embodiment, the path from the gas supply pipe 50 through the internal space of the housing 10 to the gas discharge pipe 60 forms an external flow path A that passes outside the heating furnace 20 to the component gas detection unit 70. Here, the connection point of the gas supply pipe 50 in the housing 10 forms the gas supply port of the internal flow path B that passes through the heating furnace. Furthermore, the path from the branch pipe 52 through the metering chamber 42, the inside of the heating furnace 20, and the gas outlets 22a, 23a, and 24a of each lid 22A, 23A, and 24A forms the heating furnace-through flow path B. Here, the connection point of the branch pipe 52 that communicates with the gas supply pipe 50 in the housing 10 forms the gas supply port of the heating furnace-through flow path B, and the gas outlet 24a provided in the lid that closes the upper end opening of the outer partition cylinder 24 forms the gas outlet of the heating furnace-through flow path B. The gas outlet 24a that forms this gas outlet communicates with the internal space of the housing 10. In other words, the gas outlet of the flow path B that passes through the heating furnace is connected to the flow path A that passes outside the heating furnace. The carrier gas containing the component gases that have been released from the sample S inside the heating furnace 20 is sent out from the gas outlet 24a (gas outlet) to the flow path A that passes outside the heating furnace, where it merges with the carrier gas flowing through the flow path A that passes outside the heating furnace, and then flows to the component gas detection unit 70.

[0036] Thus, in this embodiment, the external flow path A and the internal flow path B of the heating furnace form a carrier gas flow path, and the carrier gas flowing through these flow paths A and B transports the component gases that have been removed from the sample S inside the heating furnace 20 to the component gas detection unit 70.

[0037] Here, the external flow path A of the heating furnace is configured to rapidly transport the component gases that desorb in large quantities from the sample S to the component gas detection unit 70 without causing them to accumulate. This allows for rapid and highly accurate detection of the amount of component gas desorbed from the sample S.

[0038] Furthermore, since a large amount of H2O gas (water vapor) is released from the concrete being analyzed in this embodiment when heated, if this H2O gas (water vapor) accumulates in the internal space of the housing 10 or in the component gas detection unit 70, condensation may form on the inner wall of the housing 10 or on the sensors 71 and 72 installed in the component gas detection unit 70, which may corrode the inner wall of the housing 10 or reduce the accuracy of component gas detection by the sensors 71 and 72. However, as described above, in this embodiment, the component gases that desorb in large quantities from the sample S are quickly transported to the component gas detection unit 70 through the external flow path A of the heating furnace without accumulating, thus avoiding the occurrence of these problems due to condensation. For example, in cases where there is a large amount of desorbed gas, such as in the concrete being analyzed in this embodiment, it is preferable to flow a carrier gas of 100 L / min or more from the external flow path A of the heating furnace toward the component gas detection unit 70.

[0039] On the other hand, if a large flow rate of carrier gas is introduced through the flow path B inside the heating furnace, the inside of the heating furnace 20 will be cooled by the carrier gas, making it impossible to stably perform thermal analysis according to a pre-set temperature program, and potentially resulting in the inability to obtain highly accurate analytical data. Therefore, in this embodiment, the flow path B through the heating furnace is configured to flow a carrier gas at a smaller flow rate per unit time than the flow path A passing outside the heating furnace. This avoids the inconvenience of the inside of the heating furnace 20 being cooled by the carrier gas, making it possible to stably perform highly accurate thermal analysis.

[0040] Inside the heating furnace 20, the carrier gas flowing from the metering chamber 42 mixes with the component gases detached from the sample S, increasing the gas volume. As a result, the carrier gas containing the component gases may be forcefully ejected from the gas outlet 24a that forms the gas outlet, potentially disrupting the smooth flow of the carrier gas through the external flow path A towards the component gas detection unit 70. Therefore, in this embodiment, as shown in Figure 2, the gas outlet holes 22a, 23a, and 24a provided in each lid 22A, 23A, and 24A are formed at positions that are offset in the circumferential direction between adjacent lids when viewed from the stacking direction of each lid (between lid 22A and lid 23A, and between lid 23A and lid 24A). As a result, the carrier gas temporarily accumulates in the space between each lid 22A, 23A, and 24A, which suppresses the amount of carrier gas, including component gases, ejected from the gas outlet hole 24a that forms the gas outlet, making it possible to gently send the carrier gas into the flow path A passing outside the heating furnace.

[0041] In the structure shown in Figure 2, each lid 22A, 23A, and 24A is provided with two gas outlet holes 22a, 23a, and 24a, respectively, with the center in between, and these are positioned 90 degrees apart from each other. However, the structure is not limited to this, and the desired discharge volume can be adjusted by changing the shape and number of holes, or the amount of offset between the upper and lower holes.

[0042] In this embodiment, the component gas detection unit 70 is equipped with a gas flow meter 73 for measuring the flow velocity of the carrier gas. During the adjustment process when the device is started up, the gas flow meter 73 measures the flow velocity of the carrier gas flowing into the component gas detection unit 70, and the blower fan 51 is adjusted so that the result is a specified flow velocity. This makes it possible to repeatedly acquire 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 velocity regulator that adjusts the flow velocity of the carrier gas flowing into the component gas detection unit 70.

[0043] Furthermore, even while thermal analysis is being performed, the flow velocity of the carrier gas flowing to the component gas detection unit 70 can be measured by the gas flow velocity 73, and the blower fan 51 can be feedback-controlled to maintain a constant flow velocity.

[0044] Furthermore, in this embodiment, a CO2 sensor 54 is also installed in the hollow section of the gas supply pipe 50, upstream of the connection point 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 specific component gases desorbed from the sample S. The CO2 sensor 54 installed in the hollow section of the gas supply pipe 50 functions as an air-containing specific gas detection sensor that detects the same gas as the specific component gas (in this case, CO2) that the specific gas detection sensor is targeting, in the air taken in from the outside.

[0045] In this embodiment, where external air is used as the carrier gas, CO2, a component gas that desorbs from the sample S, is also mixed into the air taken in from the outside as the carrier gas. The amount of this mixing varies depending on the CO2 concentration in the air present outside the device. If the air used as the carrier gas contains the same gas as the component gas to be detected (i.e., CO2), the CO2 sensor 71 in the component gas detection unit 70 will detect not only the CO2 component gas that has been released from the sample S that should be detected, 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 released 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 part 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 H2O sensor 55 is also installed in the hollow section of the gas supply pipe 50, upstream of the connection point of the branch pipe 52. By subtracting the amount of H2O gas (water vapor) detected by the H2O sensor 55 installed in the hollow section of the gas supply pipe 50 from the amount of H2O gas (water vapor) detected by the H2O sensor 72 installed in the component gas detection unit 70, the amount of H2O gas (water vapor) desorbed from the sample S can be determined without error.

[0048] The thermal analysis apparatus with the above 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 that passes outside the heating furnace and a flow path B that passes inside the heating furnace. Inside the heating furnace 20, CO2 gas is released as a component gas by heating the sample S (concrete). At the same time, other component gases such as H2O gas (water vapor) contained in the sample S are also released. In this embodiment, CO2 gas and H2O gas (water vapor) are selected as the specific component gases to be detected from among these released gases, and these component gases are detected by the CO2 sensor 71 and H2O sensor 72 provided in the component gas detection unit 70. However, it is also possible to configure the system to detect other released gases.

[0049] The component gases (CO2 gas, H2O gas, etc.) that have been released from the sample S inside the heating furnace 20 are transported by carrier gas flowing through the flow path B inside the heating furnace and sent out through the gas outlet hole 24a, which is the gas outlet of the flow path, to the flow path A passing outside the heating furnace. Then, they are transported to the component gas detection unit 70 by a large amount of carrier gas flowing through the flow path A passing outside the heating furnace.

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

[0051] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and applications are possible within the scope of the invention as described in the claims. For example, in the embodiment described above, air is taken in from outside the device as the carrier gas. However, when a means is developed to supply large quantities of inert gases such as nitrogen gas at a low cost, inert gases such as nitrogen gas can also be used as the carrier gas.

[0052] Furthermore, in the embodiment described above, air (carrier gas) is supplied to the metering chamber 42 via the branch pipe 52. However, it is also possible to provide an opening in the partition wall 41 of the metering chamber 42, and allow a portion of the air (carrier gas) supplied to the internal space of the housing 10 by the gas supply pipe 50 to be taken into the metering chamber 42 through that opening.

[0053] In this configuration, an opening window is installed in the partition wall 41, and the amount of opening can be arbitrarily adjusted using the opening window, thereby allowing the amount of carrier gas to flow into the metering chamber 42 to be adjusted.

[0054] Furthermore, in the above-described embodiment, outside air is supplied by a blower fan 51 installed in the gas supply pipe 50. However, it is also possible to install a gas suction means (air intake device) such as a blower fan or suction pump on the gas discharge pipe 60 side and use its suction force to draw outside air into the gas supply pipe 50. On the gas supply pipe 50 side, air can be drawn in using various air intake devices such as suction pumps, not just the blower fan 51.

[0055] Furthermore, as shown in Figure 3, a heater 80 consisting of a panel heater, electric heating element heater, infrared heater, etc., can be installed in necessary locations such as inside the housing 10 or inside the hollow section of the gas exhaust pipe 60. By using this heater 80 to suppress condensation (solidification) of H2O gas (water vapor) contained in the carrier gas and the gas desorbed from the sample S, it is 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]

[0056] 10: Housing 20: Heating furnace, 21: Heat source (heater), 22: Inner bulkhead cylinder, 22A: Lid, 22a: Gas outlet, 23: Medium-spaced wall cylinder, 23A: Lid, 23a: Gas outlet 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 control 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 via heating furnace

Claims

1. A thermal analyzer comprising a heating furnace for heating a concrete sample placed inside, a component gas detection unit for detecting component gases detached from the sample by heating, and a carrier gas flow path for transporting the component gases detached from the sample inside the heating furnace to the component gas detection unit using a carrier gas, The carrier gas flow path is A heating furnace-through flow path having a gas supply port and a gas discharge port, wherein a carrier gas is supplied from the gas supply port into the heating furnace, and the carrier gas is discharged from the gas discharge port after passing through the inside of the heating furnace where the sample is placed, It includes a heating furnace external passage that passes through the outside of the heating furnace to the component gas detection unit, The external flow path of the heating furnace is configured to prevent condensation by allowing a larger flow rate of carrier gas than the internal flow path of the heating furnace to flow toward the component gas detection unit. Furthermore, the gas outlet of the flow path through the heating furnace is connected to the flow path passing outside the heating furnace. Furthermore, the thermal analysis apparatus is characterized in that the external flow path of the heating furnace is configured to flow a carrier gas of 100 L / min or more toward the component gas detection unit.

2. The housing comprises the aforementioned heating furnace installed inside, The thermal analysis apparatus according to claim 1, characterized in that the housing is provided with the gas supply port in the flow path through the heating furnace and the gas supply port for supplying carrier gas to the flow path passing outside the heating furnace.

3. The thermal analysis apparatus according to claim 1, characterized in that the carrier gas flow path is equipped with an air intake for taking in external air as a carrier gas.

4. A gas flowmeter for measuring the flow velocity of the carrier gas flowing into the component gas detection unit, The thermal analysis apparatus according to any one of claims 1 to 3, further comprising a gas flow rate regulator for adjusting the flow rate of the carrier gas flowing into the component gas detection unit.

5. The thermal analysis apparatus according to any one of claims 1 to 3, characterized in that it is equipped with a heater for suppressing the solidification of the gas being transported from the external flow path of the heating furnace to the component gas detection unit.

6. A sample stand placed inside the heating furnace, The thermal analysis apparatus according to claim 1, further comprising a weighing device installed below the heating furnace for measuring the weight of a sample placed on the sample stage.

7. The weighing device is located inside a weighing chamber enclosed by partition walls, and the weighing chamber is in communication with the inside of the heating furnace through an opening. The thermal analysis apparatus according to claim 6, characterized in that the carrier gas is supplied to the heating furnace through the metering chamber.

8. Inside the heating furnace, in the lower region near the opening between it and the measuring chamber, a plurality of disc-shaped convection prevention plates are arranged in the axial direction. The thermal analysis apparatus according to claim 7, characterized in that a gap is formed between the outer edge of each of the convection prevention plates and the inner surface of the heating furnace, and the carrier gas supplied to the metering chamber flows into the inside of the heating furnace through this gap.

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