Gas chromatograph apparatus

Abstract

The present invention provides a gas chromatograph apparatus capable of efficiently circulating air within a column oven. [Solution] The gas chromatograph apparatus 10 comprises a column oven 12, a heater 42, a fan 38, and a cylindrical member 40. The column oven 12 houses the column 24. The heater 42 heats the inside of the column oven 12. The fan 38 has blades 38b that rotate around a rotation axis 38a inside the column oven 12 and blows air onto the column 24 which is provided in the axial direction along the rotation axis 38a. The cylindrical member 40 is spaced apart from the column 24 in the axial direction and surrounds the outer circumference of the fan 38 along the rotation direction of the blades 38b, thereby housing at least a part of the fan 38.

Description

Technical Field

[0001] The present invention relates to a gas chromatograph apparatus.

Background Art

[0002] For example, in a gas chromatograph apparatus disclosed in Patent Document 1 below, a fan for stirring the air in the column oven is provided in the column oven. Further, a heater and a column are provided in the column oven.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a gas chromatograph apparatus, for example, when the inside of the column oven is heated, the fan and the heater are used together while the air supply port and the exhaust port of the column oven are closed. In this case, while the air in the column oven circulates, the air is heated, so that the inside of the column oven is heated. Further, when the inside of the column oven is heated, the column is also heated accordingly.

[0005] Also, for example, when the inside of the column oven is cooled, the use of the heater is stopped, and the fan is used while the air supply port and the exhaust port of the column oven are open. In this case, the air taken into the column oven from the air supply port circulates in the column oven and takes away the heat in the column oven. Further, the air that has taken away the heat in the column oven is exhausted from the exhaust port. Thereby, the inside of the column oven is cooled. Further, when the inside of the column oven is cooled, the column is also cooled accordingly.

[0006] Thus, in gas chromatography apparatuses, fans are used to heat and cool the column oven, but the airflow generated by the fan tends to spread radially away from the fan's axis of rotation. Therefore, the airflow generated by the fan has a small velocity component in the axial direction, and as a result, it takes time for the air to circulate within the column oven.

[0007] Furthermore, when multiple columns are installed in a column oven, the volume of the column oven may need to be increased. In such cases, when the volume of the column oven is increased, it is necessary to efficiently circulate the air inside the column oven in order to ensure a uniform temperature distribution.

[0008] This invention has been made in view of the above circumstances, and aims to provide a gas chromatograph apparatus that can efficiently circulate air in a column oven. [Means for solving the problem]

[0009] A first aspect of the present invention is a gas chromatograph apparatus comprising a column oven, a heater, a fan, and a cylindrical member. The column oven houses a column. The heater heats the inside of the column oven. The fan has blades that rotate about a rotation axis inside the column oven and blows air onto the column, which is provided in an axial direction along the rotation axis. The cylindrical member is spaced apart from the column in the axial direction and surrounds the outer circumference of the fan along the rotation direction of the blades, thereby housing at least a part of the fan.

[0010] A second aspect of the present invention is a gas chromatograph apparatus comprising a column oven, a heater, a fan, and a flow straightening member. The column oven houses a column. The heater heats the inside of the column oven. The fan has blades that rotate about a rotation axis inside the column oven and blows air onto the column, which is provided in an axial direction along the rotation axis. The flow straightening member straightens the air generated by the fan into an airflow about the rotation axis. [Effects of the Invention]

[0011] According to the present invention, the air inside the column oven can be circulated efficiently. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic cross-sectional view showing a part of an example of the configuration of the gas chromatograph apparatus of this embodiment. [Figure 2] This is a schematic diagram showing an example of the fan and its surrounding configuration in this embodiment. [Figure 3] This is a schematic cross-sectional view showing an example of the configuration of the cylindrical member in this embodiment. [Figure 4] This is a schematic cross-sectional view showing another example of the configuration of the cylindrical member in this embodiment. [Figure 5] This is a schematic cross-sectional view showing yet another example of the configuration of the cylindrical member in this embodiment. [Figure 6] This is a schematic cross-sectional view showing a part of an example of the configuration of a gas chromatograph apparatus in another embodiment. [Figure 7] Figure 6 is a schematic front view showing an example of the configuration of the rectifier member. [Figure 8] This is a schematic cross-sectional view showing a modified version of the gas chromatograph apparatus shown in Figure 6. [Modes for carrying out the invention]

[0013] 1. Configuration of a gas chromatograph apparatus FIG. 1 is a schematic cross-sectional view showing a part of an example of the configuration of a gas chromatograph apparatus 10 according to the present embodiment. The gas chromatograph apparatus 10 includes a column oven 12 whose temperature can be adjusted. The column oven 12 is provided with an air supply port 14 and an exhaust port 16. Further, the column oven 12 is provided with an air supply flap 18 for opening and closing the air supply port 14 and an exhaust flap 20 for opening and closing the exhaust port 16.

[0014] The gas chromatograph apparatus 10 also includes a sample introduction unit 22, a column 24, a detector 26, a temperature sensor 28, etc., which are provided inside the column oven 12. Specifically, for the sample introduction unit 22 and the detector 26, a part of them is provided inside the column oven 12.

[0015] The sample introduction unit 22 is a sample introduction unit for introducing a carrier gas and a sample gas into the column 24, and is provided with a septum (not shown). Further, a sample vaporization chamber 22a is formed inside the sample introduction unit 22.

[0016] [[ID=!1]] Furthermore, the sample introduction unit 22 includes a heater (not shown). The liquid sample introduced into the sample vaporization chamber 22a is vaporized by the heater and becomes a sample gas. However, the sample is not limited to a liquid and may be a solid or a gas.

[0017] Furthermore, a gas supply flow path 30 and a split flow path 32 communicate with the sample vaporization chamber 22a. The gas supply flow path 30 is a flow path for supplying a carrier gas into the sample vaporization chamber 22a of the sample introduction unit 22.

[0018] The split flow path 32 is a flow path for discharging a part of the gas (mixed gas of carrier gas and sample gas) in the sample vaporization chamber 22a to the outside at a predetermined split ratio when introducing the carrier gas and the sample gas into the column 24 by the split introduction method.

[0019] That is, according to the sample introduction unit 22, the sample gas is introduced into the column 24 together with the carrier gas. Further, when the sample gas is introduced into the column 24, the sample components contained in the sample gas are separated by the column 24 according to the components. Note that the column 24 is a general-purpose column.

[0020] Moreover, if it is possible to introduce the sample from the sample introduction unit 22 to the column 24, the form of the sample supplied to the sample introduction unit 22 is not particularly limited. Further, for the sample introduction unit 22, a type suitable for the form of the sample is appropriately used. For example, if the sample supplied to the sample introduction unit 22 is a gas, a type in which the sample vaporization chamber 22a is not formed is used as the sample introduction unit 22.

[0021] The detector 26 is provided for sequentially detecting various components separated by the column 24. The detector 26 is constituted by, for example, a flame ionization detector (FID). Further, the temperature sensor 28 is provided for detecting the temperature inside the column oven 12.

[0022] 2. Fan and its peripheral configuration The gas chromatograph apparatus 10 according to the present embodiment includes a drive unit 34, a transmission mechanism 36, a fan 38, a cylindrical member 40, a heater 42, etc., separately from the column 24 and the like.

[0023] FIG. 2 is a schematic view showing an example of the fan 38 and its peripheral configuration of the present embodiment. Further, FIG. 2 shows the fan 38 and the like as viewed from the transmission mechanism 36 side. Hereinafter, the fan 38 and its peripheral configuration of the present embodiment will be described with reference to FIGS. 1 and 2.

[0024] The drive unit 34 is a general-purpose motor, and the transmission mechanism 36 is a mechanism that transmits the rotational force generated by the drive unit 34 to the fan 38.

[0025] Fan 38 is a general-purpose fan and is installed inside the column oven 12. Fan 38 rotates within the column oven 12 around a rotation axis 38a. In this embodiment, fan 38 is a propeller fan having multiple blades 38b extending radially from the rotation axis 38a. Fan 38 is positioned so that its rotation axis 38a extends horizontally. Since fan 38 has multiple blades 38b, the rotation of fan 38 around the rotation axis 38a also means that the blades 38b of fan 38 rotate around the rotation axis 38a.

[0026] According to the fan 38, as shown in Figure 1, air is sent to the column 24 which is located in the direction along the rotation axis 38a (axial direction). However, if the fan 38 is a propeller fan, the air generated by the fan 38 tends to spread in the direction away from the rotation axis 38a of the fan 38 (radial direction).

[0027] The cylindrical member 40 is provided to house the fan 38. The cylindrical member 40 houses at least a portion of the fan 38 by surrounding the outer circumference of the fan 38 along the rotational direction of the fan blades 38b. The cylindrical member 40 is, for example, made of a cylindrical member with a circular cross-section perpendicular to the rotation axis 38a, and is arranged coaxially with respect to the rotation axis 38a of the fan 38, thereby enclosing the outside of the fan 38 in an annular shape. The ends of the fan blades 38b and the inner surface of the cylindrical member 40 are in close proximity.

[0028] However, the cylindrical member 40 is not limited to having a circular cross-section perpendicular to the rotation axis 38a; it may also have other shapes such as a rectangle. In the example shown in Figure 1, the cylindrical member 40 houses the entire fan 38. That is, the fan 38 is installed so as not to protrude from the cylindrical member 40 in the axial direction along the rotation axis 38a.

[0029] Furthermore, the cylindrical member 40 is spaced apart from the column 24 in the axial direction. In other words, the column 24 is located outside the cylindrical member 40 within the column oven 12. Alternatively, it can be said that the column 24 is arranged in a row with an axial gap between it and the cylindrical member 40. Specifically, the column 24 is located downstream of the airflow generated by the fan 38, with a gap between it and the cylindrical member 40. As a safety measure, a mesh or grid may be provided between the cylindrical member 40 and the column 24 to prevent the user from accidentally touching the fan 38.

[0030] The heater 42 is provided to heat the inside of the column oven 12. In the example shown in Figures 1 and 2, the heater 42 is provided on the outer circumference of the cylindrical member 40, along the rotation direction of the fan blades 38b of the fan 38. That is, the heater 42 is attached to the outside of the cylindrical member 40 and is integrally formed with the cylindrical member 40. The heater 42 includes, for example, a coil (not shown) formed by winding a metal wire, and generates heat when current is passed through the coil. The heater 42 is provided so as not to protrude from the cylindrical member 40 in the axial direction along the rotation axis 38a. However, the heater 42 is not limited to a configuration including a coil, but may also be configured in which an annular or arc-shaped heating element is provided along the outer circumference of the cylindrical member 40.

[0031] In such a gas chromatograph apparatus 10, for example, when the air intake port 14 and exhaust port 16 are closed and the fan 38 and heater 42 are used in combination, the air inside the column oven 12 circulates and is heated by the heater 42. Therefore, the inside of the column oven 12 is heated, and the column 24 is heated in the same way. The control of the heater 42 may be performed based on the temperature detected by the temperature sensor 28.

[0032] On the other hand, when the heater 42 is turned off and the air intake 14 and exhaust 16 are open, and the fan 38 is used, the air taken in from the air intake 14 circulates inside the column oven 12, removing heat from within the column oven 12. The air that has removed heat from the column oven 12 is then discharged from the exhaust 16. As a result, the inside of the column oven 12 is cooled, and the column 24 is cooled in the same way. The operation of the air intake flap 18 and exhaust flap 20 for opening and closing the air intake 14 and exhaust 16 may be controlled based on the temperature detected by the temperature sensor 28.

[0033] Furthermore, in this embodiment, as described above, since the cylindrical member 40 surrounds the outer circumference of the fan 38, tip vortices generated at the ends of the fan blades 38b are suppressed. Therefore, the wind generated by the fan 38 is less likely to spread in the direction away from the rotation axis 38a of the fan 38 (radial direction), and the reduction in the velocity component of the wind in the axial direction is suppressed.

[0034] Therefore, the cylindrical member 40 allows for efficient circulation of air within the column oven 12. Furthermore, the cylindrical member 40 enables efficient heating or cooling within the column oven 12.

[0035] Furthermore, in this embodiment, in order to further suppress the generation of wingtip vortices, that is, to circulate air in the column oven 12 more efficiently, the fan 38 is positioned so as not to protrude downstream of the wind generated by the fan 38 relative to the cylindrical member 40. Specifically, at least the ends of the blades 38b are positioned so as not to protrude downstream of the wind generated by the fan 38 relative to the cylindrical member 40.

[0036] On the other hand, the fan 38 may protrude from the cylindrical member 40 toward the upstream side of the wind generated by the fan 38. However, in this case, as described above, a part of the fan 38 is housed in the cylindrical member 40. That is, a part of the end of the blade 38b may protrude from the cylindrical member 40 toward the upstream side of the wind generated by the fan 38.

[0037] Furthermore, in this embodiment, since the heater 42 is provided on the outer circumference of the cylindrical member 40 as described above, the cylindrical member 40 is interposed between at least a portion of the column 24 and the heater 42. This suppresses the propagation of radiant heat from the heater 42 to at least a portion of the column 24.

[0038] 3. Structure of the cylindrical member Figure 3 is a schematic cross-sectional view showing an example of the configuration of the cylindrical member 40 in this embodiment. Figure 4 is a schematic cross-sectional view showing another example of the configuration of the cylindrical member 40 in this embodiment. Figure 5 is a schematic cross-sectional view showing yet another example of the configuration of the cylindrical member 40 in this embodiment.

[0039] As shown in Figures 3 to 5, the cylindrical member 40 of this embodiment specifically includes a cylindrical portion 40a and a flange portion 40b. The cylindrical portion 40a surrounds the outer circumference of the fan 38 along the rotational direction of the fan blades 38b, thereby housing at least a part of the fan 38.

[0040] The flange portion 40b is provided in the cylindrical portion 40a so as to protrude outward from the downstream end of the airflow generated by the fan 38. The flange portion 40b is an annular member arranged coaxially with the cylindrical portion 40a, and its outer diameter is larger than the outer diameter of the cylindrical portion 40a. In the cylindrical member 40, the cylindrical portion 40a and the flange portion 40b may be formed by joining separate members, or they may be formed from a single member.

[0041] Specifically, the heater 42 is provided on the outer circumference of the cylindrical portion 40a, along the rotational direction of the fan blades 38b of the fan 38. That is, the heater 42 is attached to the outside of the cylindrical portion 40a and is integrally formed with the cylindrical portion 40a. Furthermore, the heater 42 faces the column 24 with a flange portion 40b in between, so that the flange portion 40b is interposed between the column 24 and the heater 42.

[0042] In the example shown in Figure 3, the cylindrical portion 40a extends straight along the axial direction. That is, the inner and outer diameters of the cylindrical portion 40a do not change in the axial direction. Also, the angle formed by the cylindrical portion 40a and the flange portion 40b on the outer circumference of the cylindrical portion 40a is a right angle.

[0043] The cylindrical member 40 shown in Figure 4 has a more rounded periphery around the boundary between the cylindrical portion 40a and the flange portion 40b compared to the cylindrical member 40 shown in Figure 3. That is, the inner circumferential surface of the cylindrical portion 40a is continuous with the flange portion 40b via a curved surface. In the cylindrical member 40 shown in Figure 4, the cylindrical portion 40a and the flange portion 40b are formed from a single member.

[0044] However, in the cylindrical member 40 shown in Figures 3 and 4, the angle between the cylindrical portion 40a and the flange portion 40b on the outer circumference of the cylindrical portion 40a may be obtuse. That is, the flange portion 40b may be inclined so as it approaches the tip, it gradually moves towards the downstream side (column 24 side) of the wind generated by the fan 38. However, in this case, the angle between the cylindrical portion 40a and the flange portion 40b is such that the heater 42 can face the column 24 with the flange portion 40b in between.

[0045] Furthermore, the cylindrical member 40 may have a bell mouth shape, as shown in Figure 5. When the cylindrical member 40 has a bell mouth shape, the inner and outer diameters of the cylindrical portion 40a increase as they approach the downstream side (column 24 side) of the airflow generated by the fan 38.

[0046] In the example shown in Figure 5, the angle between the cylindrical portion 40a and the flange portion 40b on the outer circumference of the cylindrical portion 40a is obtuse. Furthermore, the flange portion 40b is inclined so as it approaches the tip, it gradually moves towards the downstream side (column 24 side) of the airflow generated by the fan 38. However, the angle between the cylindrical portion 40a and the flange portion 40b is such that the heater 42 can face the column 24 with the flange portion 40b in between.

[0047] Furthermore, similar to the examples shown in Figures 3 and 4, the flange portion 40b may be configured to extend in a direction perpendicular to the axial direction. For example, if the cylindrical member 40 has a bell mouth shape, similar to the example shown in Figure 4, the area around the boundary between the cylindrical portion 40a and the flange portion 40b may be rounded. That is, the inner circumferential surface of the cylindrical portion 40a may be continuous with the flange portion 40b via a curved surface.

[0048] The cylindrical portion 40a is interposed between at least a part of the column 24 and the heater 42 in a direction intersecting the axial direction, suppressing the propagation of radiant heat from the heater 42 to the column 24. The flange portion 40b is interposed between the remaining part of the column 24 and the heater 42 in the axial direction, suppressing the propagation of radiant heat from the heater 42 to the column 24. In other words, when the cylindrical member 40 includes the cylindrical portion 40a and the flange portion 40b, the propagation of radiant heat from the heater 42 to the entire column 24 is suppressed.

[0049] In this way, if the cylindrical member 40 suppresses the propagation of radiant heat from the heater 42 to the column 24, then it is possible to suppress uneven temperature distribution of the column 24 when it is heated as the column oven 12 heats up.

[0050] Furthermore, if the cylindrical member 40 has a bell mouth shape, the tip vortices generated at the ends of the fan blades 38b are further suppressed. In other words, the air inside the column oven 12 can be circulated more efficiently. For this reason, a bell mouth shape is preferred for the cylindrical member 40.

[0051] Furthermore, considering only the need to suppress the radial spread of air generated by the fan 38, the heater 42 does not necessarily have to be provided on the cylindrical member 40. For example, the heater 42 may be provided at another location inside the column oven 12, or it may be provided outside the column oven 12.

[0052] Furthermore, in this embodiment, the fan 38 is housed in the cylindrical member 40, while the column 24 and the like are not housed in the cylindrical member 40. Inside the column oven 12, the area outside the cylindrical member 40 is brighter and wider than the area inside the cylindrical member 40. Therefore, when the column 24 and the like are not housed inside the cylindrical member 40, work inside the column oven 12, specifically the replacement of the column 24, can be easily performed.

[0053] 4. Alternative Embodiments Figure 6 is a schematic cross-sectional view showing a part of an example of the configuration of a gas chromatograph apparatus 10 of another embodiment. This gas chromatograph apparatus 10 differs from the example in Figure 1 only in the configuration around the fan 38; the other configurations are the same as those in Figure 1, so the same reference numerals are used in the figure and detailed explanations are omitted.

[0054] In the example shown in Figure 6, a heater 42 is provided between the fan 38 and the column 24. That is, the heater 42 is positioned downstream of the airflow generated by the fan 38, and the column 24 is positioned further downstream. The heater 42 is formed, for example, in a mesh or spiral shape and is positioned to face forward relative to the blades 38b of the fan 38.

[0055] Furthermore, in the example shown in Figure 6, a flow straightening member 50 is provided between the heater 42 and the column 24. The flow straightening member 50 is spaced apart from the column 24 in the direction along the rotation axis 38a of the fan 38 (axial direction). A vent 51 is formed in the flow straightening member 50, and the air generated by the fan 38 is straightened by passing through the vent 51 and guided to the column 24. However, the heater 42 may be provided not only between the fan 38 and the flow straightening member 50, but also between the flow straightening member 50 and the column 24, or at other positions.

[0056] The airflow generated by the fan 38 is rectified into an airflow centered on the rotation axis 38a by passing through the vent 51 of the rectifying member 50. "Airflow centered on the rotation axis 38a" refers to, for example, an airflow that revolves around the rotation axis 38a, or an airflow that revolves in a spiral shape.

[0057] The rectifier member 50 is, for example, a plate-shaped member and functions as a partition wall that divides the space inside the column oven 12. That is, the rectifier member 50 divides the space into a first space where the fan 38 is located and a second space where the column 24 is located, and the first space and the second space may be in communication through the vent 51. In this case, the heater 42 may be located in either the first space or the second space. However, the configuration is not limited to the space inside the column oven 12 being completely partitioned by the rectifier member 50, and other vents may be provided around the rectifier member 50.

[0058] Figure 7 is a schematic front view showing an example of the configuration of the rectifier member 50 in Figure 6. In this example, a plurality of vents 51 are formed radially in the center of the plate-shaped rectifier member 50, with the rotation axis 38a of the fan 38 as the center.

[0059] Multiple vents 51 are formed so as to extend in an arc shape from the central part 52 (the part on the rotation axis 38a) of the rectifying member 50, thereby forming a vortex shape centered on the rotation axis 38a. Specifically, arc-shaped ribs 53 are formed radially from the central part 52, and arc-shaped vents 51 are formed between each of the ribs 53.

[0060] However, the rectifier member 50 is not limited to the shape shown in Figure 7, but may have any shape as long as it can rectify the airflow generated by the fan 38 into an airflow centered on the rotation axis 38a. Furthermore, the airflow centered on the rotation axis 38a generated by the rectifier member 50 may rotate clockwise or counterclockwise with respect to the rotation axis 38a.

[0061] Figure 8 is a schematic cross-sectional view showing a modified example of the gas chromatograph apparatus in Figure 6. In this example, the only difference from the example in Figure 6 is the provision of a cylindrical member 54 that guides the airflow generated by the fan 38 to the rectifier member 50. Since the other components are the same as those in Figure 6, the same reference numerals are used in the figure and detailed explanations are omitted.

[0062] The cylindrical member 54 covers the outer circumference of the fan 38 along the blades 38b. Specifically, the front (upstream) end of the cylindrical member 54 is radially opposite to the blades 38b, and the rear (downstream) end is close to or connected to the rectifier member 50. As a result, at least a portion of the fan 38 is covered by the cylindrical member 54, and the air generated by the fan 38 is guided to the rectifier member 50 through the space (wind tunnel) inside the cylindrical member 54.

[0063] The cylindrical member 54 is not limited to a configuration that covers the entire fan 38, but may cover only a part of it. The cylindrical member 54 is preferably located close to the tip of the blade 38b, but is not limited to this; for example, the cylindrical member 54 may be provided along the inner surface of the column oven 12. Furthermore, the cylindrical member 54 is not limited to a cylindrical shape, but may have other shapes. In the example shown in Figure 8, the heater 42 is located inside the cylindrical member 54, but is not limited to this configuration; the heater 42 may be located outside the cylindrical member 54.

[0064] 5. Appearance Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following embodiments.

[0065] (Article 1) A gas chromatograph apparatus according to one embodiment is: A column oven for housing the column, A heater for heating the inside of the column oven, A fan having blades that rotate around a rotation axis within the column oven, and which blows air onto the column provided in the axial direction along the rotation axis, The fan may also include a cylindrical member that is spaced apart from the column in the axial direction and surrounds the outer circumference of the fan along the rotation direction of the blades, thereby housing at least a portion of the fan.

[0066] According to the gas chromatograph apparatus described in paragraph 1, the airflow generated by the fan is less likely to spread away from the fan's axis of rotation, allowing for efficient circulation of air within the column oven. Furthermore, when heating or cooling the column oven, the fan circulates the air within it. Therefore, if the air within the column oven can be efficiently circulated, the column oven can be efficiently heated or cooled.

[0067] (Paragraph 2) In the gas chromatograph apparatus described in Paragraph 1, The fan may be positioned so as not to protrude downstream from the cylindrical member in the direction of the airflow generated by the fan.

[0068] According to the gas chromatograph apparatus described in paragraph 2, the airflow generated by the fan is less likely to spread away from the fan's axis of rotation, thus allowing for more efficient circulation of air within the column oven.

[0069] (3) In the gas chromatograph apparatus described in paragraph 1 or 2, The heater may be provided on the outer circumference of the cylindrical member, along the direction of rotation of the blades.

[0070] According to the gas chromatograph apparatus described in paragraph 3, the propagation of radiant heat from the heater to at least a portion of the column is suppressed. Furthermore, if the propagation of radiant heat from the heater to the column is suppressed, it is possible to suppress the occurrence of temperature unevenness in the column when the column is heated as the column oven is heated.

[0071] (Article 4) In the gas chromatograph apparatus described in Article 3, The cylindrical member includes a cylindrical portion and a flange portion, The cylindrical portion surrounds the outer circumference of the fan along the rotational direction of the blades, thereby housing at least a part of the fan. The flange portion is provided in the cylindrical portion so as to protrude outward from the downstream end of the airflow generated by the fan. The heater may be provided on the outer circumference of the cylindrical portion, along the direction of rotation of the blades, and facing the column across the flange portion.

[0072] According to the gas chromatograph apparatus described in Section 4, the propagation of radiant heat from the heater to the entire column is suppressed. Furthermore, this makes it possible to further suppress temperature unevenness in the column when it is heated as the column oven is heated.

[0073] (Item 5) In the gas chromatograph apparatus described in Item 4, The cylindrical member may also have a bell mouth shape.

[0074] According to the gas chromatograph apparatus described in Section 5, tip vortices generated at the ends of the fan blades are more suppressed, allowing for more efficient circulation of air within the column oven.

[0075] (Clause 6) A gas chromatograph apparatus according to one embodiment is: A column oven for housing the column, A heater for heating the inside of the column oven, A fan having blades that rotate around a rotation axis within the column oven, and which blows air onto the column provided in the axial direction along the rotation axis, The system may also include a flow straightening member that straightens the airflow generated by the fan into an airflow centered on the axis of rotation.

[0076] According to the gas chromatograph apparatus described in Section 6, the airflow generated by the fan is rectified to flow around the axis of rotation, increasing the proportion of axial airflow and improving the agitation efficiency of the air in the column oven. As a result, the air in the column oven can be circulated efficiently, making it possible to achieve a uniform temperature distribution within the column oven. Furthermore, because the proportion of axial airflow increases, it becomes possible to achieve a uniform temperature distribution within the column oven even when the fan speed is reduced. Therefore, this contributes to a longer fan lifespan, lower power consumption, and lower noise levels, as well as improving the cooling efficiency within the column oven, thus contributing to a shorter cooling time.

[0077] (Section 7) In the gas chromatograph apparatus described in Section 6, The system may further include a cylindrical member that surrounds the outer circumference of the fan along the direction of rotation of the blades, thereby housing at least a portion of the fan and guiding the airflow generated by the fan to the rectifying member.

[0078] According to the gas chromatograph apparatus described in Section 7, the airflow generated by the fan can be efficiently guided to the rectifying member, thereby generating a strong airflow centered on the axis of rotation. Consequently, the agitation efficiency of the air in the column oven is further improved, and the air in the column oven can be circulated even more efficiently.

[0079] (Paragraph 8) In the gas chromatograph apparatus described in paragraph 6 or 7, The rectifying member may have vents formed in a spiral shape around the axis of rotation.

[0080] According to the gas chromatograph apparatus described in paragraph 8, the air generated by the fan can be efficiently converted into an airflow centered on the rotation axis through vents formed in a spiral shape around the rotation axis. [Explanation of symbols]

[0081] 10. Gas chromatograph apparatus 12-column oven 24 columns 38 Fans 38a Rotation axis 38b Feather 40 Cylindrical member 40a Cylindrical section 40b Flange section 42 Heater 50 Rectifying member 51 Ventilation opening 54 Cylindrical member

Claims

1. A column oven for housing the column, A heater for heating the inside of the column oven, A fan having blades that rotate around a rotation axis within the column oven, and which blows air onto the column provided in the axial direction along the rotation axis, A gas chromatograph apparatus comprising a cylindrical member that is spaced apart from the column in the axial direction and surrounds the outer circumference of the fan along the rotation direction of the blades, thereby housing at least a portion of the fan.

2. The gas chromatograph apparatus according to claim 1, wherein the fan is arranged so as not to protrude downstream of the cylindrical member toward the wind generated by the fan.

3. The gas chromatograph apparatus according to claim 1 or 2, wherein the heater is provided on the outer circumference of the cylindrical member along the rotational direction of the blades.

4. The cylindrical member includes a cylindrical portion and a flange portion, The cylindrical portion surrounds the outer circumference of the fan along the rotational direction of the blades, thereby housing at least a part of the fan. The flange portion is provided in the cylindrical portion so as to protrude outward from the downstream end of the airflow generated by the fan. The gas chromatograph apparatus according to claim 3, wherein the heater is provided on the outer circumference of the cylindrical portion along the rotational direction of the blades and faces the column across the flange portion.

5. The gas chromatograph apparatus according to claim 4, wherein the cylindrical member has a bell mouth shape.

6. A column oven for housing the column, A heater for heating the inside of the column oven, A fan having blades that rotate around a rotation axis within the column oven, and which blows air onto the column provided in the axial direction along the rotation axis, A gas chromatograph apparatus comprising a flow straightening member that straightens the airflow generated by the fan into an airflow centered on the rotation axis.

7. The gas chromatograph apparatus according to claim 6, further comprising a cylindrical member that surrounds the outer circumference of the fan along the rotation direction of the blades, thereby housing at least a portion of the fan and guiding the air generated by the fan to the rectifying member.

8. The gas chromatograph apparatus according to claim 6 or 7, wherein the rectifying member has vents formed in a spiral shape around the axis of rotation.

Images