JP3088606B2 - Constant temperature bath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermostat used for chromatographic analysis and the like.

[0002]

2. Description of the Related Art For example, a thermostat used for chromatographic analysis has conventionally been constructed as shown in FIG.
That is, in this figure, reference numeral 51 denotes a thermostat main body configured to be hermetically sealable, and its internal space 52 is formed in a box shape such as a cube or a rectangular parallelepiped. One end of the box-shaped space 52 is provided with an annular column 5.
3 is held by a suitable holding member (not shown) so that its annular center is horizontal. Reference numeral 54 denotes a propeller-type fan arranged on the other end side of the box-shaped space 52, which is rotatably driven by a driving unit 55 provided outside the thermostat main body 51.

A partition plate 56 is provided between the column 53 and the fan 54 in a vertical direction, and has a plurality of ventilation holes (not shown) formed on the surface thereof. Then, on one side (for example, the fan 54 side) of the partition plate 56,
A heating element 57 made of a heating wire is annularly held so as to correspond to the annular column 53.

[0004] In the thermostatic bath configured as described above,
The sample is introduced from one end 53a of the column 53 and exits from the other end 53b. When the heating element 57 generates heat, the heat is generated by the airflow generated by the rotation of the fan 54, and the annular column 5 is heated.
The sample is sent to the side 4, which heats the sample moving in the column 54.

[0005]

By the way, the airflow generated in the thermostat main body 51 by the rotation of the fan 54 first rises or descends along the inner side wall of the thermostat main body 51 as shown by an arrow in the drawing. Then, it passes through the upper or lower ventilation hole of the partition plate 56 to reach the column 53 side, and then flows and circulates through the central portion of the column 53 and the central portion of the partition plate 56 so as to be sucked into the fan 54. .

In this case, since the internal space 52 of the constant temperature bath 51 is box-shaped, there is a difference between the length of the internal space 52 in the diagonal direction and the length in the side direction.
In the circumferential direction, there is a difference in how the hot air hits, which causes uneven heating of the column 53. Column 5
If the heating of 3 is not performed uniformly, the behavior of the sample inside will vary, which will have a subtle effect on the retention time and the like, which will adversely affect the measurement accuracy of the chromatographic analysis.

[0007] The present invention has been made in consideration of the above-mentioned matters, and has as its object to provide a constant temperature bath capable of uniformly heating a column in any portion thereof.

[0008]

In order to achieve the above object, a thermostat according to the present invention has a sirocco fan provided substantially at the center of a sealable thermostat main body, and a heating element is disposed at the center of the sirocco fan. In addition, a column formed annularly outside the sirocco fan is arranged concentrically with the sirocco fan, and a plurality of partition plates are arranged between the sirocco fan and the column.

Instead of this configuration, a sirocco fan is provided substantially at the center of the hermetic thermostat main body, and a ring-shaped heating element is arranged concentrically with the sirocco fan outside the sirocco fan. Further, a column formed in an annular shape outside the heating element is arranged concentrically with the sirocco fan and the heating element, and further, a plurality of partition plates are arranged between the sirocco fan and the heating element. Is also good.

In each of the above-mentioned constant temperature baths, a partition plate is provided, but this may be omitted.

Further, the inner wall of the thermostat main body may be formed in a cylindrical shape.

[0012]

When, for example, a plurality of partition plates are radially provided between a sirocco fan and a column, heat generated from the heating element spreads radially and is uniformly transmitted to the column. As a result, a temperature deviation due to a difference in the position in the circumferential direction of the column can be eliminated, and any part of the column is uniformly heated. Almost the same effects can be obtained when other configurations are employed.

[0013]

1 to 3 show a first embodiment of the present invention. In these figures, reference numeral 1 denotes a thermostat main body, which is surrounded by a suitable heat insulating material 2. Although not shown in detail, the thermostatic bath main body 1 is configured to be hermetically sealable, for example, to be able to open and close a door provided on a front side.
The inner wall 3 of the thermostat main body 1 is formed in an upright cylindrical shape. Reference numeral 4 denotes an internal space surrounded by the inner wall 3. Reference numeral 5 denotes an annular base frame provided below the inside of the thermostat main body 1, and a bar 6 is provided radially from the center thereof.

7 is provided at substantially the center of the thermostat main body 1,
A sirocco fan having blades 8 formed in a circumferential portion, and is held and mounted on a base frame 5 via a thrust bearing (not shown) so that a rotating shaft 9 is vertical. Reference numeral 10 denotes a drive unit of the sirocco fan 7, which is provided, for example, below the outside of the thermostat main body 1. Reference numeral 11 denotes a power supply lead.

Reference numeral 12 denotes the center (inside) of the sirocco fan 7
Annular heating element (heater) concentrically arranged
The heating element 12 is held by being suspended from an upper support member 14 which is held substantially horizontally by a column 13 erected on the base frame 5, and both ends of the heating element 12 are connected to an appropriate drawing member 15. And is led out of the thermostat main body 1 through the

Reference numeral 16 denotes an annular column having a diameter of, for example, about 180 to 200 mm which is provided concentrically with the sirocco fan 7 and the heating element 12 so as to surround the heating element 12 and surround the heating element. It consists of a thin tube of about 0.3 mm. Both ends of the column 16 are led out of the thermostat main body 1 via an appropriate drawer member 17. Reference numeral 18 denotes a holding member for preventing the shape of the column 16 from being collapsed.

Reference numeral 19 denotes a plurality of partition plates which are erected on the base frame 5 between the sirocco fan 7 and the column 16 and are made of, for example, a stainless steel plate having an appropriate thickness.
As shown in FIG. 1, the circumference is radially provided so as to divide the circumference into eight equal parts. In this case, the upper end of the partition plate 19 is preferably slightly higher than the upper end of the sirocco fan 7.

Next, the operation of the constant temperature bath configured as described above will be described. Now, when the sirocco fan 7 is operated, an outward airflow is generated. This air flow is made radial by a plurality of partition plates 19 which are equally arranged radially around the sirocco fan 7. In this state, the heating element 1
When electricity is supplied to the heater 2 to generate heat, heat is generated from the entire circumference. This heat is applied to the column 1 provided outside the partition plate 19 by the airflow flowing radially outward.
It is carried in six directions. Thereby, the column 16 is heated.

The airflow that hits the column 16 and heats it flows from the outside of the column 16 to the center of the sirocco fan 7 through the upper space or lower space of the thermostat main body 1. Thus, by arranging the plurality of partition plates 19 radially between the sirocco fan 7 and the column 16,
The air flow generated by the sirocco fan 7 is rectified and flows radially, so that the heat from the heating element 12 also moves, so that the column 16 is uniformly heated in the circumferential direction, and the temperature distribution in the circumferential direction is reduced. Become uniform.

In this embodiment, since the internal space 4 of the thermostatic chamber main body 1 is surrounded by the cylindrical inner wall 2, the uniformity of the temperature distribution in the circumferential direction of the column 16 can be more effectively achieved. realizable.

In the above-described embodiment, the sirocco fan 7 is provided substantially at the center of the thermostatic chamber main body 1, and the heating element 12 is arranged at the center of the sirocco fan 7, and the sirocco fan 7 is formed in an annular shape outside the sirocco fan 7. The divided columns 16 are arranged concentrically with the sirocco fan 7, and a plurality of partition plates 19 are radially arranged between the sirocco fan 7 and the column 16. However, the partition plates 19 need to be provided radially. No, and sirocco fan 7 and heating element 1
2 may be reversed, and when strict temperature control is not necessarily required, the partition plate 19 may be omitted. Hereinafter, these alternative embodiments will be described with reference to FIG.
This will be described in detail with reference to FIG.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, for example, eight partition plates 19 are provided between the sirocco fan 7 and the column 16 in the tangential direction of the sirocco fan 7. Are arranged equally. In this case, the partition plate 19 is erected on the base frame 5 such that the upper end thereof is slightly higher than the upper end of the sirocco fan 7.

In the thermostat of the second embodiment, since the partition plate 19 is provided slightly densely around the sirocco fan 7, the heat of the heating element 12 is hardly radiated directly to the column 16. However, as in the first embodiment, the airflow from the sirocco fan 7 is rectified by the partition plate 19, so that the column 16 is uniformly heated in the circumferential direction, and the temperature distribution in the circumferential direction becomes uniform. .

FIG. 5 shows a third embodiment of the present invention. In this embodiment, for example, three partition plates 19 are provided between the sirocco fan 7 and the column 16 in the tangential direction of the sirocco fan 7. Are arranged equally. In this case, although not shown in detail, the partition plate 19 is not erected on the base frame 5 but is suspended from the upper support member 14 so that the lower end thereof is slightly higher than the upper end of the sirocco fan 7. Can be lowered.

In the constant temperature bath of the third embodiment, the second
Although the number of the partition plates 19 is smaller than that of the first embodiment, the degree of rectification of the airflow is smaller than that of the second embodiment. Is uniformly heated in the circumferential direction, and the temperature distribution in the circumferential direction becomes uniform.

In each of the first to third embodiments described above, the heating element 12 is provided at the center of the sirocco fan 7, but this arrangement may be reversed. In this case, the partition plate 19 is provided between the sirocco fan 7 and the heating element 12. That is, FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, a slightly smaller diameter sirocco fan 7 is disposed substantially at the center of the thermostatic chamber main body 1 and an annular heat generating member is provided outside the sirocco fan 7. The body 12 is provided concentrically with the sirocco fan 7, and an annular column 16 is provided outside the heating element 12 concentrically with the sirocco fan 7 and the heating element 12.
Between the sirocco fan 7 and the heating element 12, for example, eight partition plates 19 are equally arranged radially.

In the constant temperature bath of the fourth embodiment, the air flow generated by the sirocco fan 7
The heat is rectified and flows radially toward the heating element 12, and the heat generated in the heating element 12 moves toward the column 16 carried by the radial airflow. Therefore, in this embodiment, as in the first embodiment, the column 16
Is uniformly heated in the circumferential direction, and the temperature distribution in the circumferential direction becomes uniform.

In the fourth embodiment, the partition plate 19 is provided radially. Alternatively, FIG.
As in the second and third embodiments shown in FIG.
May be provided in the tangential direction of the sirocco fan 7 (not shown).

In any of the first to fourth embodiments, the partition plate 19 is provided to induce a rectified or radial airflow in the thermostat main body 1, and the heat generated by the heating element 12 is converted into a column by the airflow. Although the sirocco fan 7 can generate airflow in the circumferential direction, the sirocco fan 7 can uniformly heat the column 16 in the circumferential direction without providing the partition plate 19, The temperature distribution in the circumferential direction can be made uniform.

FIGS. 7 and 8 show an embodiment in which the partition plate 19 is not provided. That is, FIG. 7 shows the fifth embodiment of the present invention.
In this embodiment, a slightly small-diameter sirocco fan 7 is disposed substantially at the center of the thermostat main body 1 and an annular heating element 12 is provided outside the sirocco fan 7.
And an annular column 1 outside the heating element 12.
6 is provided concentrically with the sirocco fan 7 and the heating element 12.

In the thermostatic oven of the fifth embodiment, when the heating element 12 is energized while the sirocco fan 7 is operated to generate heat, heat is radiated from the entire circumference. This heat is carried in the direction of the column 16 by the airflow radially sent outward by the blades 8 of the sirocco fan 7. Thereby, the column 16 is heated. The airflow that hits the column 16 and heats it flows from the outside of the column 16 to the center of the heating element 12 through the upper space or lower space of the thermostat main body 1. By performing the heat transfer in this manner, the column 16 is uniformly heated in the circumferential direction, and the temperature distribution in the circumferential direction becomes uniform.

FIG. 8 shows a sixth embodiment of the present invention. In this embodiment, an annular heating element 12 is provided substantially in the center of a thermostatic chamber main body 1 and an outer side of the heating element 12 is provided. The sirocco fan 7 is arranged concentrically, and the column 14 is arranged concentrically with the sirocco fan 7 outside the sirocco fan 7. Since the operation of this embodiment is almost the same as that of the fifth embodiment, a detailed description thereof will be omitted. Also in this embodiment, the column 16 is heated uniformly in the circumferential direction, and the temperature distribution in the circumferential direction becomes uniform. Also,
In this embodiment, the radiant heat of the heating element 12 is
There is no direct hit to 6.

FIG. 9 shows the first embodiment (FIGS. 1 to 3) and the second embodiment.
In each of the thermostats of the embodiment (FIG. 4), the third embodiment (FIG. 5) and the fifth embodiment (FIG. 7), the temperature change when the temperature inside the thermostat main body 1 is controlled to 50 ° C. to 50 ° C. As can be seen, from these temperature change curves, the degree of occurrence of the temperature adjustment ripple in the thermostat main body 1 and the magnitude of the temperature position deviation of the column 16 (temperature difference at each position of the column 16) can be found.

That is, FIGS. 9A, 9B, 9C and 9D respectively show the first embodiment, the second embodiment,
Tests of the third embodiment (in the above embodiments, the sirocco fan 7 and the partition plate 19 are provided) and the fifth embodiment (in which the sirocco fan 7 is provided, but the partition plate 19 is not provided) It shows the results. Then, FIG.
Is a comparative example, in which the sirocco fan 7 was not rotated in the constant temperature bath of the fifth embodiment.

The result of FIG. 9 will be described in more detail.
As shown in FIG. 3E, even when the sirocco fan 7 is provided, the sirocco fan 7 is not operated and the air in the thermostat main body 1 is not agitated. The positional deviation was as high as 2.5 ° C.

On the other hand, when the sirocco fan 7 is provided and the partition plates 19 are provided radially as in the first embodiment, as shown in FIG. Also, the temperature position deviation is as small as 0.5 ° C.

When the sirocco fan 7 is provided and the partition plate 19 is provided slightly densely in the tangential direction of the sirocco fan 7 as in the second embodiment, as shown in FIG. Although the temperature control ripple of 1. occurs,
The temperature is within 0 ° C., and the temperature position deviation is as very small as 0.5 ° C.

In the case where the sirocco fan 7 is provided and the partition plate 19 is provided slightly sparsely in the tangential direction of the sirocco fan 7 as in the third embodiment, as shown in FIG. Although the temperature control ripple of 1. occurs,
It is within 0 ° C., and the temperature position deviation is very small at 0.4 ° C.

Further, when the sirocco fan 7 is provided as in the fifth embodiment but the partition plate 19 is not provided, the temperature control ripple becomes large, but the temperature does not swell with the passage of time. Further, the temperature position deviation was 1.4 ° C., which is considerably improved as compared with the comparative example.

From these facts, in any of the above-mentioned embodiments, it is possible to uniformly apply hot air in the circumferential direction of the column 16 to make the temperature distribution in the circumferential direction uniform. Therefore, since the behavior of the sample in the column 16 can be made constant, high reproducibility of the retention time can be obtained, and the measurement accuracy of the chromatographic analysis can be increased.

In particular, in a thermostat provided with a combination of the sirocco fan 7 and the partition plate 19, there is little or no ripple at all, so that the chromatographic analysis in which the retention time and the like are strictly controlled is used. Particularly preferred.

In the first to third embodiments and the sixth embodiment, the heating element 12 is formed in an annular shape. However, it is not necessary to make the heating element 12 so that heat can be uniformly radiated to the surroundings. It only has to be formed.

[0043]

As described above, according to the present invention, it is possible to uniformly apply hot air in the circumferential direction of the column to make the temperature distribution in the circumferential direction uniform. Therefore, it is possible to stabilize the behavior of the sample in the column,
High reproducibility of the retention time can be obtained, and the measurement accuracy of the chromatographic analysis can be increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a constant temperature bath according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the constant temperature bath.

FIG. 3 is an explanatory diagram schematically showing a configuration of the constant temperature bath.

FIG. 4 is an explanatory view schematically showing a configuration of a constant temperature bath according to a second embodiment of the present invention.

FIG. 5 is an explanatory view schematically showing a configuration of a constant temperature bath according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram schematically showing a configuration of a constant temperature bath according to a fourth embodiment of the present invention.

FIG. 7 is an explanatory view schematically showing a configuration of a constant temperature bath according to a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram schematically showing a configuration of a constant temperature bath according to a sixth embodiment of the present invention.

FIG. 9 is a diagram showing measurement results of a temperature control ripple and a temperature position deviation in a thermostat of a typical embodiment of the present invention.

FIG. 10 is a diagram schematically showing a configuration of a conventional thermostat.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Thermostat main body, 2 ... Inner wall, 7 ... Sirocco fan, 12
... heating element, 16 ... column, 19 ... partition plate.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 30/54

Claims (5)

(57) [Claims] 1. A sirocco fan is provided substantially at the center of a hermetic thermostat main body, a heating element is arranged at the center of the sirocco fan, and a column formed in an annular shape outside the sirocco fan is mounted on the sirocco fan. A constant temperature bath characterized by being arranged concentrically with a sirocco fan and a plurality of partition plates between a sirocco fan and a column. 2. A sirocco fan is provided substantially at the center of a hermetic thermostat main body, and a heating element formed annularly outside the sirocco fan is disposed concentrically with the sirocco fan. A thermostatic bath characterized by arranging a column formed annularly outside of the sirocco fan and the heating element concentrically, and further arranging a plurality of partition plates between the sirocco fan and the heating element. 3. A sirocco fan is provided substantially at the center of the hermetic thermostat main body, a heating element is arranged at the center of the sirocco fan, and a column formed in an annular shape outside the sirocco fan is mounted on the sirocco fan. A thermostat characterized by being arranged concentrically with the 4. A sirocco fan is provided substantially at the center of a sealable thermostat main body, and a heating element formed in an annular shape outside the sirocco fan is disposed concentrically with the sirocco fan. A thermostat having an annular column formed concentrically with the sirocco fan and the heating element. 5. The constant temperature bath according to claim 1, wherein an inner wall of the constant temperature bath body is cylindrical.