JPH0219739Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a constant temperature bath used in a gas chromatograph or the like.

For example, in a gas chromatograph, a column for separating each component in a measurement gas is placed in a constant temperature bath.

FIG. 1 is a configuration explanatory diagram showing an example of such a conventional device, and the internal space is vertically partitioned by a partition plate 1 with a hole bored in the center. A column 2 is arranged as a controlled object, a fan 3 for stirring heated air inside is arranged at the bottom of the partition plate 1, a heater 4 is arranged near the bottom of the outer periphery of the partition plate 1, Board 1
A temperature sensor 5 is arranged between the column 2 and the column 2. The upper member 6 is pivoted with a hinge 7 as a door so that it can be opened and closed when replacing the column 2, etc.
An intake port 10 is provided at the bottom portion 8 so as to communicate with the inside along the rotation axis 9 of the fan 3, and an exhaust port 11 is provided along the side surface so as to communicate with the outside. Note that these intake ports 10 and exhaust ports 1
1 is provided with doors 13 and 14 that are driven by, for example, a stepping motor 12 to open and close the intake port 10 and the exhaust port 11 in synchronization. Incidentally, the fan 3 is a fan that sends out air radially, such as a Sirotskov fan, and is rotationally driven by a stepping motor 15.

However, according to such a conventional configuration, an intake port 10 and an exhaust port 11 having opening/closing means 12 and 13 must be provided on the bottom surface 8, which makes the configuration complicated and expensive. Further, since the exhaust ports 11 are provided at offset positions on the bottom surface 8, the flow of air inside the column 2 becomes non-uniform, which may cause a temperature gradient in the column 2.

The present invention was developed in view of these points, and its purpose is to provide a thermostatic chamber with a relatively simple configuration, in which the internal air flow is averaged and temperature gradients are less likely to occur within the chamber. be.

The present invention that achieves this objective has an interior partitioned vertically by a partition plate, an object to be controlled is placed on the upper side of the partition plate, and a hole in the center of the partition plate is placed on the lower side of the partition plate. A fan that generates air that passes below the partition plate and passes through the outside of the partition plate to the top of the partition plate, and a heater that heats the air generated by the fan are disposed; A thermostatic chamber in which a temperature sensor is disposed near the chamber, the bottom surface of which is provided with an intake port having an opening/closing means, and a pressureless section or a pressureless section formed by the rotation of the fan with the intake port closed. It is characterized in that at least one exhaust port is provided on the side surface of the positive pressure section in the vicinity thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a configuration explanatory diagram showing one embodiment of the present invention, and the same parts as in FIG. 1 are denoted by the same reference numerals. In the figure, although an intake port 10 is provided on the bottom surface 8 as in FIG. 1, an equivalent to the exhaust port 11 in FIG. 1 is not provided. That is, in FIG. 2, the exhaust ports 16 and 17 are the same as the intake port 10.
is provided on the side surface of the no-pressure section formed by the rotation of the fan 3 when the door 13 is closed or the positive-pressure section near the no-pressure section. Note that the arrow in the figure indicates the intake port 10.
Indicates the direction of the wind when the door 13 is closed,
This shows that the wind that comes out radially from the fan 3 and passes through point A, for example, passes through B, C, D, and E and is sucked into the fan 3 again. FIG. 3 shows the pressure fluctuation along the path passing through each point A to E. As can be seen from Fig. 3, the position immediately after exiting fan 3 is positive pressure and the highest pressure.
At the position immediately before entering the fan 3, there is a negative pressure and the pressure is the lowest. In addition, M, P, and Z in the figure indicate the pressure when the door 13 of the intake port 10 is closed, and M indicates a negative pressure section. , P indicates a positive pressure section, and Z indicates a no pressure section. Third
If we were to use a diagram to show the no-pressure area or the positive pressure area near it, it would be, for example, the range L in the diagram. Furthermore, the range F in FIG. 3 indicates the range where the fan 3 is being passed.

The operation of the device configured in this way will be explained.

When heating the inside, the door 13 of the intake port 10
is closed and the heater 4 is energized to generate heat. In this state, there is almost no pressure near the exhaust ports 16 and 17, and there is almost no pressure difference between the inside and the outside.
There is almost no air flowing through 6 and 17.

On the other hand, in the case of cooling, the door 13 of the intake port 10 is opened by the stepping motor 12. and,
For example, if the set temperature is 50°C, when the measured value of the temperature sensor 5 drops to 50°C, the power supply to the heater 4 is restarted and the cooling operation is stopped. Here, if there is a large amount of current flowing through the heater 4, the interior is too cold, so the opening and closing of the door 13 is automatically controlled to keep the current at the minimum necessary. In such a cooling operation, external air is circulated inside as follows. When the door 13 is opened, external air flows into the interior from the intake port 10 according to the negative pressure generated by the rotation of the fan 3, and the internal pressure increases. When the pressure increases, the pressure near the exhaust ports 16 and 17, which was almost pressureless when the door 13 was closed, changes to positive pressure, and the heated air inside flows out to the outside. The cold air from outside that flows into the interior according to the negative pressure caused by the rotation of the fan 3 is uniformly mixed in the space below the partition plate 1 by the rotation of the fan 3.
It is applied to the space above the partition plate 1 through the heater 4 and the partition plate 1. Therefore, a temperature gradient is less likely to occur around the column 2.

With this configuration, the exhaust port on the bottom surface unlike the conventional one is not required, and the configuration can be simplified. Further, there is no need to provide a door to the exhaust port provided on the side, and space for providing a door can be saved.
It is also possible to provide many small holes as exhaust ports on the side of the non-pressure area or the positive pressure area (slightly positive pressure area) near it. By providing multiple small holes in symmetrical positions, it is possible to make the air flow uneven can be made smaller,
In particular, it is possible to prevent temperature non-uniformity during heating.
Further, the number of exhaust ports may be one.

Incidentally, in the above embodiment, an example of a constant temperature bath whose controlled object is a gas chromatograph column has been described, but the present invention is not limited to this, and is effective for controlling the temperature of various controlled objects.

As explained above, according to the present invention, it is possible to realize a constant temperature chamber with a relatively simple structure that hardly causes a temperature gradient inside, and it is highly effective in cooling from a constant temperature state and controlling temperature around room temperature.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of a conventional device, FIG. 2 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIG.
It is a figure which shows the pressure fluctuation in the path|route which passes each point of A-E in a figure. 1... Partition plate, 2... Controlled object (column),
3... Fan, 4... Heater, 5... Temperature sensor, 6... Upper member, 7... Hinge, 8... Bottom,
9...Rotating shaft, 10...Intake port, 12...Stepping motor, 13...Opening/closing means (door), 15...
...Motor, 16, 17...Exhaust port.

Claims (1)

[Scope of utility model registration request] The interior is vertically partitioned by a partition plate, the object to be controlled is arranged on the upper side of the partition plate, and the object to be controlled is placed on the lower side of the partition plate. A fan that generates air passing through the outside of the partition plate to the upper side of the partition plate and a heater that heats the air generated by the fan are arranged, and a temperature sensor is further arranged near the partition plate. In the constant temperature chamber, an inlet having an opening/closing means is provided on the bottom surface thereof, and an air inlet is provided on the side surface of the no-pressure section formed by the rotation of the fan with the inlet port closed or the positive pressure section near the no-pressure section. A thermostatic chamber characterized by having at least one exhaust port.