Elemental analysis device, method of operating elemental analysis device, and storage medium

Abstract

The present application provides an elemental analysis device, an operation method of the elemental analysis device, and a storage medium. The degassing mechanism (4) includes: a pressure feeding flow path (41) that pressure feeds purge gas to the heating furnace (1); an exhaust flow path (42) that communicates the heating furnace (1) with outside air and exhausts the purge gas pressure fed into the heating furnace (1) to the outside air; and a purge gas flow rate adjusting mechanism (43) that changes the flow path resistance of the exhaust flow path (42) in multiple stages or continuously and adjusts the flow rate of the purge gas.

Description

Technical Field

[0001] This invention relates to an elemental analysis apparatus for analyzing elements contained in a sample based on a sample gas generated by heating the sample. Background Technology

[0002] In such an elemental analysis apparatus, for example, a sample is placed in a graphite crucible placed in a heating furnace, and the sample is heated by causing the graphite crucible to heat up by allowing an electric current to flow through it.

[0003] In this type of elemental analysis apparatus, the heating furnace is turned on and the graphite crucible is replaced each time an analysis is performed. However, since atmospheric components will enter the heating furnace at this time, or there may be residual sample gas generated during the previous analysis, it is necessary to perform degassing (purging) to remove the residual gas in the heating furnace before analysis.

[0004] Therefore, existing elemental analysis devices are equipped with a pressure flow channel for pressing purge gas, such as He and Ar, which are inactive gases, from a gas storage cylinder to a heating furnace, and an exhaust flow channel for discharging the purge gas pressed into the heating furnace, so that the purge gas circulates in the heating furnace and discharges the residual gas together with the purge gas.

[0005] However, because a capillary tube is provided in the discharge channel, the flow rate of the purging gas is limited to a certain extent, so degassing requires a certain amount of time.

[0006] Therefore, as shown in Patent Document 1 (Japanese Utility Model Application Publication No. 5-33057), the following structure can be considered: a jet pump is connected to the rear end of the discharge channel, and the residual gas is discharged from the heating furnace for a short time by suction.

[0007] Patent Document 1: Japanese Utility Model Application Publication No. 5-33057

[0008] However, with this structure, if analysis begins immediately after degassing, the furnace is under negative pressure. Therefore, when switching the furnace connection to an analytical device with NDIR or similar equipment for analysis, pressure fluctuations occur, leading to inconsistent analytical accuracy. Conversely, returning the furnace to the required positive pressure necessitates starting from negative pressure, which takes time, preventing a significant reduction in analysis time.

[0009] Furthermore, since the jet pump draws in unlimited quantities, there is a possibility that the purge gas will be consumed in large quantities during degassing. Summary of the Invention

[0010] In view of the above-mentioned problems, the present invention aims to provide an elemental analysis apparatus that can shorten the time required for degassing without sacrificing analytical accuracy, thereby allowing for a moderate consumption of purge gas.

[0011] That is, the elemental analysis apparatus of the present invention includes: a heating furnace for heating a sample to generate sample gas; an analysis unit for analyzing the elements contained in the sample based on the sample gas; and a degassing mechanism for allowing purge gas to flow and discharging residual gas in the heating furnace, wherein the degassing mechanism includes: a pressure delivery channel for pressurizing purge gas into the heating furnace; a discharge channel for connecting the heating furnace to external air and discharging the purge gas pressurized into the heating furnace to the external air; and a purge gas flow rate regulating mechanism for causing the flow resistance of the discharge channel to vary in multiple stages or continuously.

[0012] With this structure, during degassing before analysis, the flow resistance of the discharge channel is first reduced and purge gas is allowed to flow, thus completing degassing essentially in a short time. Then, by increasing the flow resistance of the discharge channel, the internal pressure of the furnace is increased simultaneously with degassing, utilizing the pressure rise effect based on the flow resistance. This allows the furnace to immediately reach a stable analytical state after degassing. Furthermore, adjusting the flow resistance optimizes the consumption of purge gas.

[0013] Therefore, according to the present invention, the time required for degassing can be shortened while maintaining analytical accuracy, and the consumption of purge gas can also be moderate.

[0014] As a specific implementation that can fully improve the effect with a simple structure, one example is that the discharge channel has a first exhaust channel and a second exhaust channel arranged in parallel with each other, and the purge gas flow regulating mechanism includes a switching valve, which causes the flow resistance of the discharge channel to change in two stages by opening and closing the second exhaust channel.

[0015] If the first exhaust channel includes a resistance flow path such as a capillary tube, and the second exhaust channel is essentially composed only of piping components, then when the switch valve is opened, the heating furnace communicates with the outside air through the second exhaust channel, maintaining a near-atmospheric pressure while the purge gas flows. This allows for degassing in a shorter time. Conversely, even if the purge gas flow rate is lower than before, an equivalent degassing effect can be achieved in the same amount of time. This was first discovered by the inventors. Based on this understanding, it was determined that when the same flow rate of purge gas flows through the heating furnace, the degassing effect is better when the heating furnace is at atmospheric pressure versus under higher pressure.

[0016] If the flow resistance of the discharge channel is set to be low for a specified period and then changed to a state with high flow resistance, the flow resistance of the discharge channel will be high at the end of degassing, and the pressure inside the heating furnace will be high, thus allowing for a smooth transition to the next analysis step.

[0017] If a purge gas flow limiting mechanism is also included, which is disposed in the pressure delivery channel to limit the maximum flow rate of the purge gas, excessive purge gas can be prevented from flowing during degassing, thus reducing the waste of purge gas and achieving cost reduction.

[0018] In order to cope with various states, it is preferable that the purge gas flow limiting mechanism is configured to switch between an operating state in which flow limiting is performed and a non-operating state in which flow limiting is not performed.

[0019] For example, it can be considered that the purge gas flow limiting mechanism is activated when the flow resistance of the discharge channel is low, and is deactivated when the flow resistance of the discharge channel is high.

[0020] The present invention can also be an operating method of an elemental analysis apparatus, wherein, when the purge gas is discharged, the purge gas flow rate regulating mechanism is operated to maintain the flow resistance of the discharge channel at a low level for a specified period, and then the flow resistance is changed to a high level.

[0021] Furthermore, the present invention can also be a storage medium storing an operating program for an elemental analysis device, wherein the operating program of the elemental analysis device causes a computer to perform the following function: when the purge gas is discharged, the purge gas flow rate regulating mechanism is operated to maintain the flow resistance of the discharge channel at a low level for a specified period, and then the flow resistance is changed to a high level.

[0022] Thus, the elemental analysis apparatus according to the present invention can improve degassing efficiency without sacrificing analytical accuracy. Attached Figure Description

[0023] Figure 1 This is an overall structural diagram of an elemental analysis apparatus according to one embodiment of the present invention.

[0024] Figure 2 This is an explanatory diagram showing the flow of purge gas during the degassing operation of an elemental analysis apparatus of the same embodiment.

[0025] Figure 3 This is an explanatory diagram showing the flow of purge gas during the degassing operation of an elemental analysis apparatus of the same embodiment.

[0026] Figure 4 This is an explanatory diagram showing the flow of purge gas during the degassing operation of an elemental analysis apparatus of the same embodiment.

[0027] Figure 5This is an explanatory diagram showing the flow of purge gas during the degassing operation of an elemental analysis apparatus of the same embodiment.

[0028] Figure 6 This is an explanatory diagram showing the flow of carrier gas and sample gas during analysis in an elemental analysis apparatus of the same embodiment.

[0029] Figure 7 These are experimental results data representing the effects of the same implementation method.

[0030] Explanation of reference numerals in the attached figures

[0031] 100 elemental analysis apparatus

[0032] 1 Heating Furnace

[0033] 2. Analysis Department

[0034] 4. Degassing mechanism

[0035] 41. Pressure delivery channel

[0036] 42 Discharge channel

[0037] 421 First Exhaust Passage

[0038] 422 Second exhaust passage

[0039] 43. Purging gas flow regulation mechanism

[0040] V1 Switch Valve Detailed Implementation

[0041] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

[0042] like Figure 1 As shown, the elemental analysis apparatus 100 of this embodiment, for example, quantifies the type and amount, or proportion, of elements contained in the sample by heating a metal sample and a ceramic sample (hereinafter referred to as the sample) and analyzing the gas generated at this time (hereinafter referred to as the sample gas). It generally includes the following parts.

[0043] (1) Heating furnace 1, heating the sample.

[0044] (2) Analysis unit 2, analyzes the sample gas generated in the heating furnace 1.

[0045] (3) Sample gas delivery mechanism 3 introduces He and Ar as inactive gases into the heating furnace 1 and sends the sample gas and the carrier gas together into the analysis section 2.

[0046] Next, each part will be explained.

[0047] The heating furnace 1 heats the sample, for example, by heating a graphite crucible 11 in which the sample is placed. The heating furnace 1 is configured to open in a split manner, allowing the graphite crucible 11 to be inserted into the furnace in the open state. Furthermore, the graphite crucible 11 is held by a pair of electrodes, and an electric current is passed from the electrodes to the graphite crucible 11 to heat it.

[0048] The analysis unit 2, for example, measures the concentrations (amounts) of O, H, and N contained in the sample by measuring CO, N2, and H2 in the sample gas. Although not shown, the analysis unit 2 includes multiple NDIR (non-dispersive infrared gas analyzers), TCD (thermal conductivity detectors), oxidizers, gas removal agents, etc. Details of these are cited in Japanese Patent Application Publication No. 2013-250061, etc.

[0049] The sample gas delivery mechanism 3 includes: a carrier gas inlet channel 31 for introducing the carrier gas into the heating furnace 1; and a sample gas delivery channel 32 for sending the sample gas generated in the heating furnace 1 together with the carrier gas into the analysis unit 2.

[0050] The carrier gas inlet channel 31 is mainly composed of piping components. Its starting end is connected to a high-pressure gas cylinder (not shown), which serves as the supply source of the carrier gas, and its ending end is connected to a gas inlet located in the heating furnace 1. Additionally, a pressure regulating valve (not shown) is provided upstream of the carrier gas inlet channel 31. Using this pressure regulating valve, the pressure inside the heating furnace 1 can be adjusted to a pressure exceeding atmospheric pressure, such as 80 kPa (absolute pressure 180 kPa), when heating the sample.

[0051] The sample gas delivery channel 32 is mainly composed of piping components. Its beginning end is connected to the gas outlet provided in the heating furnace 1, and its end end is connected to the analysis unit 2. In addition, a dust filter (not shown) is provided on the sample gas delivery channel 32 to filter and remove dust and other contaminants contained in the sample gas.

[0052] Based on the above structure, the elemental analysis device 100 also includes a degassing mechanism 4. The degassing mechanism 4 pressurizes the carrier gas, which also serves as the purge gas, into the heating furnace 1, and discharges residual gases and other wastes in the heating furnace 1 together with the carrier gas into the outside air. The degassing mechanism 4 will be described in detail below, but for ease of understanding, the carrier gas is sometimes referred to as the purge gas.

[0053] Specifically, the degassing mechanism 4 includes: a pressurizing channel 41 for pressurizing purge gas into the heating furnace 1; a discharge channel 42 for connecting the heating furnace 1 with external air and discharging the purge gas pressurized into the heating furnace 1 to the external air; and a purge gas flow rate regulating mechanism 43 for changing the flow resistance of the discharge channel 42 in two stages.

[0054] In this embodiment, the carrier gas inlet channel 31 also functions as the pressure delivery channel 41, but the pressure delivery channel 41 and the carrier gas inlet channel 31 can also be set independently.

[0055] The discharge channel 42 is mainly composed of piping components. Its beginning is connected to a predetermined section in the middle of the sample gas delivery channel 32, and its end is open to the outside air. In addition, a switching valve V4, which is a three-way valve, is provided at the connection point, which is configured to allow the gas in the heating furnace 1 to be discharged to the outside air through the discharge channel 42, or to be introduced into the analysis unit through the sample gas delivery channel 32.

[0056] In addition, the discharge channel 42 is divided into two paths, a first exhaust channel 421 and a second exhaust channel 422. A capillary tube C1 is provided in the first exhaust channel 421 as a resistance channel, so that the flow resistance of the first exhaust channel 421 is higher than that of the second exhaust channel 422.

[0057] The purge gas flow rate regulating mechanism 43 includes a switching valve V1, which is disposed on the second exhaust channel 422, causing the flow resistance of the discharge channel 42 to vary in two stages. That is, if the switching valve V1 is opened, the flow resistance of the discharge channel 42 decreases, allowing a large flow of purge gas to pass through; if the switching valve V1 is closed, the flow resistance increases, allowing a small flow of purge gas to pass through.

[0058] Furthermore, in this embodiment, a purge gas flow limiting mechanism 44 for specifying the maximum flow rate of purge gas during degassing and a resistance additional mechanism 7 for depressurization are connected in series on the pressure delivery channel 41.

[0059] Specifically, the purge gas flow limiting mechanism 44 includes a capillary tube C3, which serves as a resistance flow path, disposed on the pressure delivery channel 41. In this embodiment, a bypass is disposed parallel to the capillary tube C3, and a switching valve V3 is disposed on the bypass. Moreover, when the switching valve V3 is closed, the purge gas passes only through the capillary tube C3, resulting in a flow control state due to the resistance of the capillary tube C3, i.e., the purge gas flow limiting mechanism 44 is in an operating state. On the other hand, when the switching valve V3 is open, the purge gas mainly passes through the bypass, which has virtually no resistance, resulting in an uncontrolled flow state, i.e., the purge gas flow limiting mechanism 44 is in a non-operating state.

[0060] The resistance-adding mechanism 7 is used to increase the flow resistance of the pressure delivery channel 41. Specifically, it includes a capillary tube C2, which serves as a resistance flow channel, disposed on the pressure delivery channel 41. In this embodiment, a bypass is disposed parallel to the capillary tube C2, and a switching valve V2 is disposed on the bypass. Moreover, when the switching valve V2 is closed, the purge gas passes only through the capillary tube C2, resulting in a flow resistance added by the capillary tube C2, i.e., the operating state of the resistance-adding mechanism 7. On the other hand, when the switching valve V2 is open, the purge gas passes through the bypass with virtually no resistance, resulting in a state without added flow resistance, i.e., the non-operating state of the resistance-adding mechanism 7.

[0061] In addition, in this embodiment, an instruction device (not shown) is provided for electrically controlling the switching valves. This instruction device includes a computer, which includes, for example, a CPU, memory, an A / D converter, a D / A converter, and various input / output devices. The instruction device sends instruction signals to the valves according to a program stored in the memory, thereby controlling their operation, by coordinating the CPU and its peripheral devices.

[0062] In addition, Figure 1 In this embodiment, the flow channel 6 and the switching valve V5 are used to supply purge gas to the analysis unit 2. During degassing, the switching valve V5 is operated, simultaneously purging the analysis unit 2.

[0063] Next, the degassing operation of the elemental analysis device 100 will be described.

[0064] In the degassing operation, the following steps are performed in sequence before analysis: an initial pressurization operation to pressurize the heating furnace 1, a depressurization operation to remove the pressure from the heating furnace, a high-speed degassing operation to flow purge gas while keeping the pressurized furnace 1 at a low pressure (atmospheric pressure in this case), and a pre-analytical degassing operation to flow purge gas while making the heating furnace 1 at the high pressure required for analysis.

[0065] In addition, during the series of degassing actions, each valve is automatically controlled using command signals from the command device.

[0066] First, before the degassing process begins, an empty graphite crucible 11 is placed inside the heating furnace 1.

[0067] Next, perform the initial pressurization action for a short time (e.g., 2 seconds).

[0068] In the initial pressurization action, such as Figure 2 As shown, the switching valve V4 is opened towards the discharge channel 42. Furthermore, the switching valves V3 and V2 of the purge gas flow limiting mechanism 44 and the resistance-adding mechanism 7 are open, and both the purge gas flow limiting mechanism 44 and the resistance-adding mechanism 7 are in a non-operating state. Subsequently, the switching valve V1 of the purge gas flow regulating mechanism 43 is closed, and the purge gas flow regulating mechanism 43 is in a state where the purge gas only flows through the capillary tube C1, i.e., the flow resistance of the exhaust channel 42 is relatively high.

[0069] Then, the switch valve (not shown) located at the base of the pressure delivery channel 41 is opened, and the purge gas flows into the heating furnace 1 from the pressure delivery channel 41 and is discharged from the exhaust channel 42. In the initial pressurization state, there is essentially no flow resistance on the pressure delivery channel 41 side. On the other hand, since the exhaust channel 42 side has flow resistance generated by the capillary C1, the pressurization furnace 1 reaches a higher pressure (e.g., 80 kPa) based on the pressure regulating valve (not shown) located at the base of the pressure delivery channel 41. Furthermore, the purge gas flow rate is essentially determined solely by the flow resistance of the capillary C1 of the purge gas flow rate regulating mechanism 4. Additionally, since the flow resistance of the capillary C1 in this embodiment is set lower than the flow resistance of the other capillary C2 and C3 (the specific order of flow resistance in this embodiment is C2 > C3 > C1), the purge gas flow rate is greater than the purge gas flow rates during the depressurization operation and the high-speed degassing operation described later.

[0070] Next, the depressurization action is performed for a short time (e.g., 1 second).

[0071] During the pressure relief operation, such as Figure 3 As shown, the switching valves V3 and V2 of the purge gas flow limiting mechanism 44 and the resistance adding mechanism 7 are closed, and both the purge gas flow limiting mechanism 44 and the resistance adding mechanism 7 are in the activated state. On the other hand, the switching valve V1 of the purge gas flow regulating mechanism 43 is open, and the purge gas flow regulating mechanism 43 is in a state unaffected by the flow resistance of the capillary C1, that is, the flow resistance of the exhaust flow channel 42 is low.

[0072] Therefore, the flow resistance on the pressure channel 41 side is relatively large due to its connection with capillary tubes C2 and C3, while the flow resistance on the exhaust channel 42 side is basically zero. Thus, the pressure furnace 1 changes from the high-pressure state at the initial pressurization operation to the atmospheric pressure of the exhaust channel 42. The purge gas flow rate is essentially determined by the resistance of the series flow of capillary tubes C2 and C3. However, since this series flow resistance is much greater than the flow resistance of capillary tube C1, the purge gas flow rate is much smaller than the purge gas flow rate at the initial pressurization operation.

[0073] Next, perform a high-speed degassing action at a predetermined time (e.g., 30 seconds).

[0074] During the high-speed degassing operation, such as Figure 4 As shown, the switching valve V2 of the resistance addition mechanism 7 is opened, and the resistance addition mechanism 7 becomes non-operating.

[0075] Therefore, the flow resistance on the pressurization flow channel 41 side is generated by the capillary C3 of the purge gas flow limiting mechanism 44, while the exhaust flow channel 42 side has virtually no flow resistance. Thus, the pressurization furnace 1 maintains atmospheric pressure in the same way as the depressurization operation. The purge gas flow rate is determined by the flow resistance of the capillary C3. However, since this flow resistance is set to be higher than that of the capillary C1, the purge gas flow rate is less than the purge gas flow rate during the initial pressurization operation but more than the purge gas flow rate during the depressurization operation.

[0076] Then, the pre-analysis degassing process continues for a predetermined time (e.g., 5 seconds).

[0077] During the pre-analysis degassing process, such as Figure 5 As shown, the switching valve V3 of the purge gas flow limiting mechanism 44 is open, the purge gas flow limiting mechanism 44 is in a non-operating state, and the switching valve V1 of the purge gas flow regulating mechanism 43 is closed, so that the purge gas only flows through the capillary tube C1, that is, the flow resistance of the exhaust channel 42 is relatively large. This state is the same as the state during the initial pressurization operation.

[0078] Therefore, similar to the initial pressurization operation, the pressurizing furnace 1 reaches a high pressure (e.g., 80 kPa) based on the pressure regulating valve (not shown) located at the base end of the pressurization channel 41. Furthermore, the purge gas flow rate is the same as that during the initial pressurization operation.

[0079] Furthermore, during the aforementioned degassing operation, high-speed degassing operation, and pre-analytical degassing operation, the graphite crucible 11 is heated while empty. This heating is intended to remove the hydrogen (H), oxygen (O), and nitrogen (N) adsorbed on the inner wall of the graphite crucible 11 and the heating furnace 1, and to reliably discharge them using the purge gas.

[0080] Furthermore, the predetermined time for each action can be changed by the operator or others inputting the instruction device or the like during each analysis.

[0081] Subsequently, switch valve V4 is switched to open to the sample gas delivery channel 32.

[0082] Thus, the degassing process ends, as follows: Figure 6 As shown, the carrier gas is introduced into the analysis unit 2 through the heating furnace, and the sample is ready for analysis. Then, if a sample is placed into the graphite crucible 11 inside the heating furnace 1, the analysis operation begins.

[0083] According to this structure, when degassing is performed before the analysis begins, a high-speed degassing action is first performed to bring the pressure of the heating furnace 1 close to atmospheric pressure (which is actually basically atmospheric pressure) and to circulate purge gas, thereby essentially completing the degassing in a short time. Then, a pre-analysis degassing action is performed to increase the flow resistance of the discharge channel 42 while maintaining the degassing action, and to increase the internal pressure of the heating furnace 1 by utilizing the pressure increase effect based on the flow resistance. Thus, even if the heating furnace 1 is connected to the analysis unit 2 for analysis, it can immediately become a state that can be stably analyzed, that is, the high pressure state inside the heating furnace 1 is basically maintained unchanged.

[0084] Therefore, while maintaining analytical accuracy, the degassing time can be shortened compared to the past. Furthermore, if the degassing time remains the same, the consumption of purge gas can be reduced compared to the past.

[0085] The reason why purging can be performed in a short time during the aforementioned high-speed degassing operation is that the heating furnace 1 reaches atmospheric pressure. The inventors have discovered that even at the same flow rate, the closer the heating furnace is to atmospheric pressure, the better the degassing effect, as shown in the experimental data below. Figure 7 As shown. In the Figure 7 The coordinate graph shows that the further to the left the peak is, the better the degassing effect. It is clear from this graph that, in the case of oxygen, the lower the pressure and the closer it gets to atmospheric pressure, the further to the left the peak is. The same trend applies to nitrogen.

[0086] In this embodiment, by adjusting the flow resistance value of capillary C3, the purge gas flow rate is reduced compared to the past, the consumption of purge gas is reduced, and the purge time is shortened.

[0087] Furthermore, the present invention is not limited to the embodiments described above.

[0088] For example, the purge gas flow regulating mechanism 43 can also be equipped with two or more capillary tubes in parallel, so that the purge gas flow rate can be switched in three or more stages. Variable valves can also be used in the resistance flow channel to continuously change its resistance, enabling stepless and continuous adjustment of the purge gas flow rate. In this case, the purge gas flow rate is throttled at the end of degassing, and the heating furnace 1 is brought to a predetermined pressurized state at the end of degassing.

[0089] Resistance channels are not limited to capillary tubes; they can also be throttling orifices, etc.

[0090] Alternatively, the beginning of the discharge channel 42 can be directly connected to the heating furnace 1, or the carrier gas inlet channel 31 and the pressure delivery channel 41 can be set independently, so that the channel system of the carrier gas used during analysis is independent of the channel system of the purge gas used during degassing. In this case, different types of gases can also be used for the carrier gas and the purge gas.

[0091] As long as they have equivalent functions, various on / off valves, switching valves, or their related piping structures can be changed, for example, by using other types of valves.

[0092] The purge gas flow limiting mechanism 44 is not required.

[0093] Resistance channels are not limited to capillary tubes; they can also be formed by throttling orifices, etc.

[0094] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical concept of the present invention.

[0095] Industrial applicability

[0096] According to the present invention described above, the elemental analysis apparatus includes: a heating furnace for heating a sample to generate a sample gas; an analysis unit for analyzing the elements contained in the sample based on the sample gas; and a degassing mechanism 4 for allowing purge gas to circulate and discharging residual gas from the heating furnace. In this elemental analysis apparatus, the degassing time can be shortened without sacrificing analytical accuracy.

Claims

1. An elemental analysis apparatus, comprising: A heating furnace heats the sample to generate sample gas; an analysis unit analyzes the elements contained in the sample based on the sample gas. The elemental analysis apparatus is characterized by a degassing mechanism that allows purge gas to circulate and expel residual gases from the heating furnace. The degassing mechanism includes: A pressure delivery channel is used to pressurize and deliver purging gas into the heating furnace; The exhaust channel connects the heating furnace to the outside air, allowing the purge gas compressed into the heating furnace to be discharged to the outside air; and The purge gas flow rate regulating mechanism causes the flow resistance of the discharge channel to change in multiple stages or continuously, thereby regulating the flow rate of the purge gas. The discharge channel has a first exhaust channel and a second exhaust channel arranged in parallel with each other. The purging gas flow rate regulating mechanism includes a switching valve, which causes the flow resistance of the discharge channel to change in two stages by opening and closing the second exhaust channel.

2. The elemental analysis apparatus according to claim 1, characterized in that, The first exhaust passage includes a resistance flow channel, and the flow resistance of the first exhaust passage is higher than that of the second exhaust passage.

3. The elemental analysis apparatus according to claim 2, characterized in that, The second exhaust passage consists only of piping components.

4. An elemental analysis apparatus, comprising: A heating furnace heats the sample to generate sample gas; an analysis unit analyzes the elements contained in the sample based on the sample gas. The elemental analysis apparatus is characterized by a degassing mechanism that allows purge gas to circulate and expel residual gases from the heating furnace. The degassing mechanism includes: A pressure delivery channel is used to pressurize and deliver purging gas into the heating furnace; The exhaust channel connects the heating furnace to the outside air, allowing the purge gas compressed into the heating furnace to be discharged to the outside air; and The purge gas flow rate regulating mechanism causes the flow resistance of the discharge channel to change in multiple stages or continuously, thereby regulating the flow rate of the purge gas. After the purge gas flow rate regulating mechanism maintains a low flow resistance in the discharge channel for a specified period, it then changes the flow resistance to a higher state. The discharge channel has a first exhaust channel and a second exhaust channel arranged in parallel with each other. The purging gas flow rate regulating mechanism includes a switching valve, which causes the flow resistance of the discharge channel to change in two stages by opening and closing the second exhaust channel.

5. The elemental analysis apparatus according to claim 4, characterized in that, The first exhaust passage includes a resistance flow channel, and the flow resistance of the first exhaust passage is higher than that of the second exhaust passage.

6. The elemental analysis apparatus according to claim 5, characterized in that, The second exhaust passage consists only of piping components.

7. An elemental analysis apparatus, comprising: A heating furnace heats the sample to generate sample gas; an analysis unit analyzes the elements contained in the sample based on the sample gas. The elemental analysis apparatus is characterized by a degassing mechanism that allows purge gas to circulate and expel residual gases from the heating furnace. The degassing mechanism includes: A pressure delivery channel is used to pressurize and deliver purging gas into the heating furnace; The exhaust channel connects the heating furnace to the outside air, allowing the purge gas compressed into the heating furnace to be discharged to the outside air; and The purge gas flow rate regulating mechanism causes the flow resistance of the discharge channel to change in multiple stages or continuously, thereby regulating the flow rate of the purge gas. The elemental analysis apparatus further includes a purge gas flow limiting mechanism, which is disposed in the pressure delivery channel to limit the maximum flow rate of the purge gas. The purge gas flow limiting mechanism is configured to switch between an active state that performs flow limiting and a non-active state that does not perform flow limiting. The discharge channel has a first exhaust passage and a second exhaust passage arranged parallel to each other. The purge gas flow rate regulating mechanism includes a switching valve, which causes the flow resistance of the discharge channel to vary in two stages by opening and closing the second exhaust passage. When the second exhaust passage is open, the purge gas flow limiting mechanism is activated; when the second exhaust passage is closed, the purge gas flow limiting mechanism is deactivated.

8. The elemental analysis apparatus according to claim 7, characterized in that, The first exhaust passage includes a resistance flow channel, and the flow resistance of the first exhaust passage is higher than that of the second exhaust passage.

9. The elemental analysis apparatus according to claim 8, characterized in that, The second exhaust passage consists only of piping components.

10. A method of operating an elemental analysis apparatus, the elemental analysis apparatus comprising: A heating furnace heats the sample to generate sample gas; an analysis unit detects the sample gas and analyzes the elements contained in the sample. And a degassing mechanism to allow purge gas to circulate and expel residual gas from the heating furnace. The degassing mechanism includes: a pressure conveying channel for pressurizing and conveying purge gas to the heating furnace; The system includes a discharge channel that connects the heating furnace to the outside air, allowing the purge gas compressed into the heating furnace to be discharged to the outside air; and a purge gas flow rate regulating mechanism that allows the flow resistance of the discharge channel to vary in multiple stages or continuously. The characteristic of the operation method of the elemental analysis device is that... When the purge gas is discharged, the purge gas flow rate regulating mechanism is operated to maintain the flow resistance of the discharge channel at a low level for a specified period, and then the flow resistance is changed to a high level.

11. A storage medium, characterized in that, The system stores the operating program of an elemental analysis apparatus, which includes: a heating furnace for heating a sample to generate sample gas; an analysis unit for detecting the sample gas and analyzing the elements contained in the sample; and a degassing mechanism for allowing purge gas to circulate and remove residual gas from the heating furnace. The degassing mechanism includes: a pressurizing channel for pressurizing purge gas into the heating furnace; a discharge channel for connecting the heating furnace to external air and discharging the purge gas pressurized into the heating furnace to the external air; and a purge gas flow rate regulating mechanism for varying the flow resistance of the discharge channel in multiple stages or continuously. The operating program of the elemental analysis device enables the computer to perform the following functions: When the purge gas is discharged, the purge gas flow rate regulating mechanism is operated to maintain the flow resistance of the discharge channel at a low level for a specified period, and then the flow resistance is changed to a high level.

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