Gas chromatography apparatus

Abstract

Provided is a gas chromatograph device that efficiently circulates air in a column oven. A gas chromatograph device (10) includes a column oven (12), a heater (42), a fan (38), and a cylindrical member (40). The column oven (12) houses a column (24). The heater (42) heats the inside of the column oven (12). The fan (38) has a blade (38b) that rotates about a rotational axis (38a) in the column oven (12) and transports air to the column (24) disposed in a direction along the rotational axis (38a), i.e., an axial direction. The cylindrical member (40) is separated from the column (24) in the axial direction and houses at least a portion of the fan (38) by surrounding an outer periphery of the fan (38) in a direction of rotation of the blade (38b) of the fan (38).

Description

TECHNICAL FIELD

[0001] The present application relates to a gas chromatograph. BACKGROUND

[0002] In a gas chromatograph such as that disclosed in Patent Document 1 described below, a fan for stirring air in a column oven is provided in the column oven. In addition, a heater and a column are provided in the column oven.

[0003] Prior art documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-205079 SUMMARY

[0006] Problems to be solved by the invention

[0007] In a gas chromatograph, for example, when the column oven is heated, the fan and the heater are used together in a state in which the air supply port and the air exhaust port of the column oven are closed. In this case, air in the column oven is circulated while being heated, and thus the column oven is heated. In addition, when the column oven is heated, the column is also heated.

[0008] In addition, for example, when the column oven is cooled, the use of the heater is stopped, and the fan is used in a state in which the air supply port and the air exhaust port of the column oven are open. In this case, air drawn into the column oven from the air supply port is circulated in the column oven and takes heat from the column oven. Then, the air that has taken the heat from the column oven is exhausted from the air exhaust port. Thus, the column oven is cooled. In addition, when the column oven is cooled, the column is also cooled.

[0009] Thus, in a gas chromatograph, the fan is used in association with heating and cooling of the column oven, but the air generated by the fan tends to spread in a direction (radial direction) away from the rotational axis of the fan. Therefore, the speed component of the air generated by the fan in the axial direction is small, and as a result, the circulation of the air in the column oven takes time.

[0010] In addition, in a case in which a plurality of columns are provided in the column oven, or the like, the volume of the column oven is sometimes increased. In a case in which the volume of the column oven is thus increased, in order to make the temperature distribution in the column oven uniform, it is necessary to circulate the air in the column oven efficiently.

[0011] The present application has been achieved in view of the above-described actual circumstances, and an object thereof is to provide a gas chromatograph capable of efficiently circulating air in a column oven.

[0012] Solution to the problem

[0013] A first aspect of the present application is a gas chromatograph device provided with 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 a blade that rotates in the column oven with a rotational axis as a center, and blows air toward the column that is disposed in a direction along the rotational axis, that is, an axial direction. The cylindrical member is separated from the column in the axial direction, and houses at least a part of the fan by surrounding an outer periphery of the fan in a rotational direction of the blade.

[0014] A second aspect of the present application is a gas chromatograph device provided with a column oven, a heater, a fan, and a rectifying member. The column oven houses a column. The heater heats the inside of the column oven. The fan has a blade that rotates in the column oven with a rotational axis as a center, and blows air toward the column that is disposed in a direction along the rotational axis, that is, an axial direction. The rectifying member rectifies the air generated by the fan into a flow of air with the rotational axis as a center.

[0015] Effects of the invention

[0016] According to the present application, air in a column oven can be efficiently circulated. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a partial cross-sectional view showing an example of a structure of a gas chromatograph device of the present embodiment.

[0018] Fig. 2 is a schematic view showing an example of a structure of a fan and its periphery of the present embodiment.

[0019] Fig. 3 is a partial cross-sectional view showing an example of a structure of a cylindrical member of the present embodiment.

[0020] Fig. 4 is a partial cross-sectional view showing another example of a structure of a cylindrical member of the present embodiment.

[0021] Fig. 5 is a partial cross-sectional view showing still another example of a structure of a cylindrical member of the present embodiment.

[0022] Fig. 6 is a partial cross-sectional view showing an example of a structure of a gas chromatograph device of another embodiment.

[0023] Fig. 7 is a schematic front view showing an example of a structure of a rectifying member of Fig. 6 .

[0024] Fig. 8 is a schematic front view showing an example of a structure of a rectifying member ofFig. 6 Fig. 6 is a schematic cross-sectional view of a modification of the gas chromatograph device of Fig. 1.

[0025] Explanation of reference numerals

[0026] 10 gas chromatograph device; 12 column oven; 24 column; 38 fan; 38a rotation axis; 38b blade; 40 cylindrical member; 40a cylindrical portion; 40b flange portion; 42 heater; 50 rectifying member; 51 vent; 54 cylindrical member. DETAILED DESCRIPTION

[0027] 1. Structure of gas chromatograph device

[0028] Fig. 1 Fig. 1 is a schematic cross-sectional view of a partial example of the structure of a gas chromatograph device 10 according to the present embodiment. The gas chromatograph device 10 is provided with a column oven 12 that can be temperature-controlled. A gas supply port 14 and a gas discharge port 16 are provided in the column oven 12. In addition, a gas supply damper 18 that opens and closes the gas supply port 14 and a gas discharge damper 20 that opens and closes the gas discharge port 16 are provided in the column oven 12.

[0029] In addition, the gas chromatograph device 10 is provided with a sample introduction portion 22, a column 24, a detector 26, a temperature sensor 28, and the like, which are provided in the column oven 12. Specifically, a portion of the sample introduction portion 22 and the detector 26 are provided in the column oven 12.

[0030] The sample introduction portion 22 is a sample introduction unit for introducing a carrier gas and a sample gas to the column 24, and is provided with a partition (omitted from the drawing). In addition, a sample gasification chamber 22a is formed in the inside of the sample introduction portion 22.

[0031] Further, the sample introduction portion 22 is provided with a heater (omitted from the drawing). A liquid sample introduced into the sample gasification chamber 22a is gasified by the heater to become a sample gas. However, the sample is not limited to a liquid, but can also be a solid or a gas.

[0032] Further, a gas supply flow path 30 and a split flow path 32 communicate with the sample gasification chamber 22a. The gas supply flow path 30 is a flow path for supplying a carrier gas to the inside of the sample gasification chamber 22a of the sample introduction portion 22.

[0033] The split flow path 32 is a flow path for discharging a portion of the gas (mixed gas of the carrier gas and the sample gas) in the sample gasification chamber 22a to the outside at a predetermined split ratio when the carrier gas and the sample gas are introduced into the column 24 by a split introduction method.

[0034] That is, the sample gas is introduced into the column 24 together with the carrier gas by the sample introduction section 22. In addition, when the sample gas is introduced into the column 24, the sample components contained in the sample gas are separated by the column 24 by component. Further, the column 24 is a general-purpose column.

[0035] In addition, if the sample can be introduced from the sample introduction section 22 to the column 24, the form of the sample supplied to the sample introduction section 22 is not particularly limited. Further, with respect to the sample introduction section 22, a kind suitable for the form of the sample is appropriately used. For example, if the sample supplied to the sample introduction section 22 is a gas, as the sample introduction section 22, a kind of sample introduction section in which a sample gasification chamber 22a is not formed is used.

[0036] The detector 26 is provided to sequentially detect various components separated by the column 24. The detector 26 is constituted by, for example, a hydrogen flame ionization detector (FID). In addition, the temperature sensor 28 is provided to detect the temperature in the column oven 12.

[0037] 2. Structure of a fan and its periphery

[0038] The gas chromatograph 10 of the present embodiment is provided with, in addition to the column 24 and the like, a driving section 34, a transmission mechanism 36, a fan 38, a cylindrical member 40, and a heater 42, and the like.

[0039] Fig. 2 is a schematic view showing an example of the structure of the fan 38 and its periphery of the present embodiment. In addition, Fig. 2 shows the fan 38 and the like as viewed from the transmission mechanism 36 side. Hereinafter, the structure of the fan 38 and its periphery will be described with reference to Fig. 1 and Fig. 2 The structure of the fan 38 and its periphery of the present embodiment will be described.

[0040] The driving section 34 is a general-purpose motor, and the transmission mechanism 36 is a mechanism that transmits the rotational force generated by the driving section 34 to the fan 38.

[0041] The fan 38 is a general-purpose fan provided in the column oven 12. In addition, the fan 38 rotates in the column oven 12 with a rotational axis 38a as a center. In the present embodiment, the fan 38 is a propeller fan having a plurality of blades 38b extending radially with the rotational axis 38a as a center. The fan 38 is disposed so that the rotational axis 38a extends in the horizontal direction. Further, since the fan 38 has a plurality of blades 38b, the rotation of the fan 38 with the rotational axis 38a as a center also means the rotation of the blades 38b of the fan 38 with the rotational axis 38a as a center.

[0042] As Fig. 1As shown, a fan 38 delivers air to a column 24 positioned 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 diffuse in a direction away from the rotation axis 38a (radial direction).

[0043] The cylindrical member 40 is provided for housing the fan 38. The cylindrical member 40 houses at least a portion of the fan 38 by surrounding the outer periphery of the fan 38 along the rotation direction of the fan blades 38b. The cylindrical member 40 is, for example, a cylindrical member with a circular cross-section orthogonal to the rotation axis 38a, and is arranged coaxially around the rotation axis 38a of the fan 38, thus forming an annular shape surrounding the outer side of the fan 38. The ends of the fan blades 38b are close to the inner circumferential surface of the cylindrical member 40.

[0044] However, the cross-section of the cylindrical member 40 orthogonal to the axis of rotation 38a is not limited to a circle; it can also be other shapes such as a rectangle. Fig. 1 In the example shown, the cylindrical member 40 houses the entire fan 38. That is, the fan 38 is configured not to protrude from the cylindrical member 40 in the axial direction along the rotation axis 38a.

[0045] Furthermore, the cylindrical member 40 is separated from the column 24 in the axial direction. That is, the column 24 is disposed outside the cylindrical member 40 within the column temperature chamber 12. Alternatively, the column 24 can be arranged at intervals relative to the cylindrical member 40 in the axial direction. Specifically, the column 24 is arranged at intervals relative to the cylindrical member 40 on the downstream side of the airflow generated by the fan 38. 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.

[0046] Heater 42 is provided for heating the interior of column oven 12. Fig. 1 and Fig. 2 In the example shown, heater 42 is disposed on the outer periphery of cylindrical member 40 along the rotation direction of blade 38b of fan 38. That is, heater 42 is integrally formed with cylindrical member 40 by being mounted on the outside of cylindrical member 40. Heater 42 includes, for example, a coil (not shown) formed by winding metal wire, which heats up by energizing the coil. Heater 42 is configured not to protrude from cylindrical member 40 in the axial direction along rotation axis 38a. However, heater 42 is not limited to a structure including a coil, and may also be a structure with annular or arc-shaped heating element disposed along the outer periphery of cylindrical member 40.

[0047] In such a gas chromatograph 10, for example, in a state where the air inlet 14 and the air outlet 16 are closed, if the fan 38 and the heater 42 are used in combination, the air in the column oven 12 is circulated while the air is heated by the heater 42. Thus, the column oven 12 is heated, and the column 24 is also heated. Further, as for the control of the heater 42, it can be performed on the basis of the detected temperature of the temperature sensor 28.

[0048] On the other hand, in a state where the use of the heater 42 is stopped and the air inlet 14 and the air outlet 16 are opened, when the fan 38 is used, the air taken in from the air inlet 14 is circulated in the column oven 12, taking the heat in the column oven 12. Then, the air that has taken the heat in the column oven 12 is discharged from the air outlet 16. Thus, the column oven 12 is cooled, and the column 24 is also cooled. Further, as for the operation of the air inlet damper 18 and the air outlet damper 20 for opening and closing the air inlet 14 and the air outlet 16, it can also be controlled on the basis of the detected temperature of the temperature sensor 28.

[0049] Further, in the present embodiment, since the cylindrical member 40 surrounds the outer periphery of the fan 38 as described above, the tip vortex generated at the end portions of the blades 38b of the fan 38 is suppressed. Thus, 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 (radially), and thus the reduction in the speed component of the wind in the axis direction is suppressed.

[0050] Thus, with the cylindrical member 40, the air in the column oven 12 can be efficiently circulated. Further, therefore, with the cylindrical member 40, the heating or cooling in the column oven 12 can be efficiently performed.

[0051] Further, in the present embodiment, in order to further suppress the generation of the tip vortex, that is, in order to more efficiently circulate the air in the column oven 12, the fan 38 is configured not to protrude toward the downstream side of the wind generated by the fan 38 with respect to the cylindrical member 40. Specifically, at least the end portions of the blades 38b are configured not to protrude toward the downstream side of the wind generated by the fan 38 with respect to the cylindrical member 40.

[0052] On the other hand, the fan 38 can also protrude toward the upstream side of the wind generated by the fan 38 with respect to the cylindrical member 40. However, in this case, as described above, the fan 38 is housed in the cylindrical member 40 in part. That is, it can also be that the end portions of the blades 38b protrude toward the upstream side of the wind generated by the fan 38 with respect to the cylindrical member 40 in part.

[0053] Further, in the present embodiment, since the heater 42 is provided at the outer periphery of the cylindrical member 40 as described above, the cylindrical member 40 intervenes between at least part of the column 24 and the heater 42. Thus, the transfer of the radiant heat generated by the heater 42 to at least part of the column 24 is suppressed.

[0054] 3. Structure of cylindrical member

[0055] Fig. 3 is a schematic cross-sectional view showing an example of the structure of the cylindrical member 40 of the present embodiment. Fig. 4 is a schematic cross-sectional view showing another example of the structure of the cylindrical member 40 of the present embodiment. Fig. 5 is a schematic cross-sectional view showing still another example of the structure of the cylindrical member 40 of the present embodiment.

[0056] As shown in Figs. 3 to 5 , the cylindrical member 40 of the present embodiment specifically includes a cylindrical portion 40a and a flange portion 40b. The cylindrical portion 40a houses at least a part of the fan 38 by surrounding the outer periphery of the fan 38 in the direction of rotation of the blades 38b of the fan 38.

[0057] The flange portion 40b is provided to project outward from the end portion of the cylindrical portion 40a on the downstream side of the wind generated by the fan 38. The flange portion 40b is a member in the shape of a circular ring arranged coaxially with the cylindrical portion 40a, and has an outer diameter larger than that of the cylindrical portion 40a. In the cylindrical member 40, the cylindrical portion 40a and the flange portion 40b can be formed by joining separate members, or can be formed by one member.

[0058] Specifically, the heater 42 is provided to the cylindrical portion 40a along the direction of rotation of the blades 38b of the fan 38 on the outer periphery of the cylindrical portion 40a. That is, the heater 42 is configured integrally with the cylindrical portion 40a by being mounted to the outer side of the cylindrical portion 40a. Further, the heater 42 opposes the column 24 with the flange portion 40b interposed therebetween, and thus the flange portion 40b is interposed between the column 24 and the heater 42.

[0059] In the example shown in Fig. 3 , the cylindrical portion 40a extends straight in the axial direction. That is, in the axial direction, the inner diameter and the outer diameter of the cylindrical portion 40a do not change. Further, on the outer periphery of the cylindrical portion 40a, the angle formed by the cylindrical portion 40a and the flange portion 40b is a right angle.

[0060] Fig. 4 The cylindrical member 40 shown in Fig. 3 compared with the cylindrical member 40 shown in Fig. 4 , the periphery of the portion corresponding to the boundary between the cylindrical portion 40a and the flange portion 40b has a roundness. That is, the inner peripheral surface of the cylindrical portion 40a is continuous with the flange portion 40b via a curved surface. Further, in the cylindrical member 40 shown in

[0061] However, in the cylindrical member 40 shown in Fig. 3 and Fig. 4In the cylindrical member 40 shown, the angle formed by the outer periphery of the cylindrical portion 40a and the flange portion 40b can also be obtuse. That is, the flange portion 40b can also be inclined in such a manner as to gradually approach the downstream side (the column 24 side) of the air generated by the fan 38 as it goes toward the top end. However, in this case, the angle formed by the cylindrical portion 40a and the flange portion 40b is to the extent that the heater 42 can oppose the column 24 via the flange portion 40b.

[0062] Further, as shown in Fig. 5 , the cylindrical member 40 can also be in the shape of a trumpet. In the case where the cylindrical member 40 is in the shape of a trumpet, the inner diameter and the outer diameter of the cylindrical portion 40a increase as it approaches the downstream side (the column 24 side) of the air generated by the fan 38.

[0063] In Fig. 5 the example shown, the angle formed by the outer periphery of the cylindrical portion 40a and the flange portion 40b is obtuse. Further, the flange portion 40b is inclined in such a manner as to gradually approach the downstream side (the column 24 side) of the air generated by the fan 38 as it goes toward the top end. However, the angle formed by the cylindrical portion 40a and the flange portion 40b is to the extent that the heater 42 can oppose the column 24 via the flange portion 40b.

[0064] In addition, as in the examples shown in Fig. 3 and Fig. 4 , the flange portion 40b can also be a structure that extends in a direction orthogonal to the axial direction. For example, in the case where the cylindrical member 40 is in the shape of a trumpet, as in the example shown in Fig. 4 , the periphery of the portion corresponding to the boundary between the cylindrical portion 40a and the flange portion 40b can also have a roundness. That is, the inner peripheral surface of the cylindrical portion 40a can also be continuous with the flange portion 40b via a curved surface.

[0065] The cylindrical portion 40a intervenes between at least a portion of the column 24 and the heater 42 in a direction intersecting the axial direction, thereby suppressing the transfer of radiant heat generated by the heater 42 to the column 24. In addition, the flange portion 40b intervenes between the remaining portion of the column 24 and the heater 42 in the axial direction, thereby suppressing the transfer of radiant heat generated by the heater 42 to the column 24. That is, in the case where the cylindrical member 40 includes the cylindrical portion 40a and the flange portion 40b, the transfer of radiant heat generated by the heater 42 to the entire column 24 is suppressed.

[0066] In this way, if the transfer of radiant heat generated by the heater 42 to the column 24 is suppressed by the cylindrical member 40, when the column 24 is heated in conjunction with the heating of the column oven 12, it is possible to suppress the temperature of the column 24 from deviating.

[0067] Further, if the cylindrical member 40 is a bell-mouth shape, the tip vortex generated at the end of the blade 38b of the fan 38 can be further suppressed. That is, the air circulation in the column oven 12 can be further efficiently performed. Thus, the shape of the cylindrical member 40 is preferably a bell-mouth shape.

[0068] In addition, if only the viewpoint of suppressing the radial diffusion of the wind generated by the fan 38 is considered, the heater 42 can not be provided to the cylindrical member 40. For example, the heater 42 can be provided to other positions in the column oven 12, or can be provided outside the column oven 12.

[0069] Further, in the present embodiment, the fan 38 is housed in the cylindrical member 40, and the column 24 or the like is not housed in the cylindrical member 40. In the column oven 12, the outside of the cylindrical member 40 is brighter and more spacious than the inside of the cylindrical member 40, and thus, in the case where the column 24 or the like is not housed in the cylindrical member 40, the work in the column oven 12, specifically, the replacement of the column 24 or the like, can be easily performed.

[0070] 4. Other Embodiment

[0071] Fig. 6 is a partial schematic cross-sectional view that shows an example of the structure of the gas chromatograph 10 of the other embodiment. In the gas chromatograph 10, only the peripheral structure of the fan 38 is different from that of the example of Fig. 1 , and the other structures are the same as those of the example of Fig. 1 , thus the same reference numerals are marked on the same structures in the drawing and the detailed description is omitted.

[0072] In the example of Fig. 6 , the heater 42 is provided between the fan 38 and the column 24. That is, the heater 42 is disposed on the downstream side of the wind generated by the fan 38, and the column 24 is disposed on the more downstream side. The heater 42 is formed, for example, in a mesh shape or a spiral shape, and is disposed in a manner of being opposed to the blade 38b of the fan 38 in front.

[0073] Further, in the example of Fig. 6 , the rectifying member 50 is provided between the heater 42 and the column 24. The rectifying member 50 is separated from the column 24 in the direction (axial direction) along the rotation axis 38a of the fan 38. The rectifying member 50 is formed with the air passage 51, and the wind generated by the fan 38 is rectified by passing through the air passage 51 and guided to the column 24. However, the heater 42 is not limited to be provided between the fan 38 and the rectifying member 50, but can be provided between the rectifying member 50 and the column 24 or at other positions.

[0074] The air generated by the fan 38 is rectified into a flow of air centered on the rotational axis 38a by passing through the air vents 51 of the rectifying member 50. The "flow of air centered on the rotational axis 38a" refers to, for example, a flow of air that revolves around the rotational axis 38a, and can be a flow of air that revolves in a spiral shape, or the like.

[0075] The rectifying member 50 is, for example, a plate-like member that functions as a partition wall that divides the space inside the column oven 12. That is, it can also be a structure in which the column oven 12 is divided into a first space in which the fan 38 is disposed and a second space in which the column 24 is disposed by the rectifying member 50, and the first space and the second space communicate via the air vents 51. In this case, the heater 42 can be disposed in the first space, or can be disposed in the second space. However, it is not limited to a structure in which the space inside the column oven 12 is completely divided by the rectifying member 50, and other air vents can be provided around the rectifying member 50.

[0076] Fig. 7 is a schematic front view that shows an example of the structure of the rectifying member 50 of Fig. 6 In this example, a plurality of air vents 51 are formed in a radial shape around the rotational axis 38a of the fan 38 in the central portion of the plate-like rectifying member 50.

[0077] The plurality of air vents 51 are formed so as to extend in a curved arc shape from the central portion 52 (portion on the rotational axis 38a) of the rectifying member 50, thereby forming a vortex shape centered on the rotational axis 38a. Specifically, the air vents 51 in a curved arc shape are formed between the ribs 53 that are formed in a radial shape from the central portion 52.

[0078] However, the rectifying member 50 can be other shapes as long as it is a shape that can rectify the air generated by the fan 38 into a flow of air centered on the rotational axis 38a, and is not limited to the shape of Fig. 7 In addition, the flow of air generated by the rectifying member 50 can be clockwise or counterclockwise with respect to the rotational axis 38a.

[0079] Fig. 8 is a schematic cross-sectional view that shows a modified example of the gas chromatograph of Fig. 6 In this example, only the fact that the cylindrical member 54 that guides the air generated by the fan 38 toward the rectifying member 50 is provided is different from the example of Fig. 6 The other structures are the same as in the example of Fig. 6 Therefore, the same reference numerals are assigned to the same structures in the drawings, and detailed descriptions thereof are omitted.

[0080] The cylindrical member 54 covers the outer periphery of the fan 38 along the blade 38b. Specifically, the end portion of the proximal side (upstream side) of the cylindrical member 54 is radially opposite to the blade 38b, and the end portion of the distal side (downstream side) is close to or connected to the rectifying member 50. Thereby, at least a part of the fan 38 is covered by the cylindrical member 54, and the air generated by the fan 38 is guided to the rectifying member 50 via the space (air tunnel) inside the cylindrical member 54.

[0081] The cylindrical member 54 is not limited to a structure that covers the entire fan 38, and can be a structure that covers only a part. The cylindrical member 54 is preferably close to the tip end of the blade 38b, but is not limited thereto, and for example, the cylindrical member 54 can be provided along the inner surface of the column oven 12. In addition, the cylindrical member 54 is not limited to a cylindrical shape, and can be other shapes. In Fig. 8 In the example, the heater 42 is provided on the inner side of the cylindrical member 54, but is not limited thereto, and can be a structure in which the heater 42 is provided on the outer side of the cylindrical member 54.

[0082] 5. Solution

[0083] As understood by those skilled in the art, the above-described various exemplary embodiments are specific examples of the following solution.

[0084] (1) One solution can be a gas chromatograph comprising:

[0085] a column oven that houses a column;

[0086] a heater that heats the inside of the column oven;

[0087] a fan that has a blade that rotates around a rotation axis in the column oven, and that blows air to the column in the axial direction along the rotation axis; and

[0088] a cylindrical member that is separated from the column in the axial direction, and that houses at least a part of the fan by surrounding the outer periphery of the fan in the rotation direction of the blade.

[0089] The gas chromatograph according to the first aspect can efficiently circulate the air in the column oven, because the air generated by the fan is less likely to spread in the direction away from the rotation axis of the fan. In addition, the air in the column oven is circulated by the fan when the inside of the column oven is heated or cooled. Thus, the inside of the column oven can be efficiently heated or cooled if the air in the column oven is efficiently circulated.

[0090] (2) The gas chromatograph according to the first aspect,

[0091] may be configured such that the fan does not protrude toward the downstream side of the air generated by the fan with respect to the cylindrical member.

[0092] The gas chromatograph according to item 2, the air generated by the fan is less likely to further spread in a direction away from the rotational axis of the fan, and thus the air in the column oven can be circulated more efficiently.

[0093] (3) The gas chromatograph according to item 1 or 2,

[0094] The heater can be provided to the cylindrical member at an outer periphery of the cylindrical member in a rotation direction of the blade.

[0095] The gas chromatograph according to item 3, the transfer of the radiant heat generated by the heater to at least a part of the column is suppressed. In addition, if the transfer of the radiant heat generated by the heater to the column is suppressed, when the column is heated in association with the heating of the column oven, the temperature of the column can be suppressed from being deviated.

[0096] (4) The gas chromatograph according to item 3, the gas chromatograph can further include:

[0097] The cylindrical member includes a cylindrical portion and a flange portion,

[0098] The cylindrical portion houses at least a part of the fan by surrounding an outer periphery of the fan in a rotation direction of the blade,

[0099] The flange portion is provided to protrude outward from an end portion of the cylindrical portion on a downstream side of the air generated by the fan,

[0100] The heater is provided to the cylindrical portion at an outer periphery of the cylindrical portion in the rotation direction of the blade, and is opposed to the column via the flange portion.

[0101] The gas chromatograph according to item 4, the transfer of the radiant heat generated by the heater to the entire column is suppressed. In addition, thus when the column is heated in association with the heating of the column oven, the temperature of the column can be further suppressed from being deviated.

[0102] (5) The gas chromatograph according to item 4,

[0103] The cylindrical member can be a bell mouth shape.

[0104] The gas chromatograph according to item 5, a tip vortex generated at an end portion of a blade of the fan is further suppressed, and thus the air in the column oven can be circulated more efficiently.

[0105] (6) The gas chromatograph according to any one of the above items can further include:

[0106] a column oven that houses a column,

[0107] a heater that heats inside the column oven;

[0108] a fan that has a blade that rotates with a rotation axis as a center in the column oven, and that blows air to the column that is disposed in a direction along the rotation axis, that is, an axial direction;

[0109] a rectifying member that rectifies the air generated by the fan into a flow of air with the rotation axis as a center.

[0110] The gas chromatograph according to item 6, the air generated by the fan is rectified into a flow of air with the rotation axis as a center, so the proportion of the air in the axial direction increases, and the stirring efficiency of the air in the column oven improves. As a result, the air in the column oven can be circulated efficiently, so the temperature distribution of the air in the column oven can be made uniform. In addition, since the proportion of the air in the axial direction increases, the temperature distribution of the air in the column oven can be made uniform even if the rotation speed of the fan is reduced. Thus, it contributes to the long life, low power consumption, and low noise of the fan, and the cooling efficiency in the column oven can be improved, so it also contributes to the shortening of the cooling time.

[0111] (7) The gas chromatograph according to item 6,

[0112] It can also be that the gas chromatograph further has a cylindrical member that houses at least a part of the fan by surrounding the outer periphery of the fan in the rotation direction of the blade, and that guides the air generated by the fan to the rectifying member.

[0113] The gas chromatograph according to item 7, the air generated by the fan can be efficiently guided to the rectifying member, so a strong flow of air with the rotation axis as a center can be generated. Thus, the stirring efficiency of the air in the column oven further improves, and the air in the column oven can be circulated more efficiently.

[0114] (8) The gas chromatograph according to item 6 or 7,

[0115] It can also be that the rectifying member has an air passage that is formed in a vortex shape with the rotation axis as a center.

[0116] The gas chromatograph according to item 8, by means of the air passage that is formed in a vortex shape with the rotation axis as a center, the air generated by the fan can be efficiently transformed into a flow of air with the rotation axis as a center.

Claims

1. A gas chromatography apparatus, wherein, This gas chromatography apparatus has the following features: Column temperature chamber, with its storage column; A heater that heats the interior of the column oven; A fan having blades that rotate about a rotation axis within the column temperature chamber, delivering air to the column positioned along the direction of the rotation axis, i.e., the axial direction; and A cylindrical member, which separates from the column in the axial direction, accommodates at least a portion of the fan by surrounding the outer periphery of the fan along the rotational direction of the blades. The heater is disposed on the outer periphery of the cylindrical member along the rotation direction of the blades. The cylindrical component includes a cylindrical portion and a flange portion. The cylindrical portion houses at least a portion of the fan by surrounding the outer periphery of the fan along the rotation direction of the blades. The flange portion is configured to protrude outward from the downstream end of the cylindrical portion, which is connected to the airflow generated by the fan. The heater is disposed on the outer periphery of the cylindrical portion along the rotation direction of the blades, and is opposite to the column across the flange portion. The cylindrical portion is located between at least a portion of the column and the heater in a direction intersecting the axial direction.

2. The gas chromatography apparatus according to claim 1, wherein, The fan is configured not to protrude downstream of the airflow generated by the fan relative to the cylindrical member.

3. The gas chromatography apparatus according to claim 1, wherein, The cylindrical component is flared.

4. A gas chromatography apparatus, wherein, This gas chromatography apparatus has the following features: Column temperature chamber, with its storage column; A heater that heats the interior of the column oven; A fan having blades that rotate about a rotation axis within the column temperature chamber, delivering air to the column positioned along the direction of the rotation axis, i.e., the axial direction; and A rectifier that rectifies the airflow generated by the fan into a flow centered on the axis of rotation. The rectifier has an air vent shaped as a vortex centered on the axis of rotation.

5. The gas chromatography apparatus according to claim 4, wherein, The gas chromatograph also includes a cylindrical component that houses at least a portion of the fan by surrounding the outer periphery of the fan along the rotation direction of the blades, and guides the airflow generated by the fan toward the rectifying component.

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