JP2002055094A - Column oven for chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance analyzing efficiency by reducing the consumption of power used in a column oven, shortening the cooling time and heating time due to the column oven and shortening the time per analysis. SOLUTION: The column oven 30 is separated into a column tank 32 and a heat accumulation tank 33 by a partition wall 31, and a column 33, a temperature sensor 35 and a fan 34 are attached in the column tank 32 and an air suction and discharge port 41 is provided to the column tank 34. A heater 51 and a heat accumulation tank temperature sensor 52 are attached in the heat accumulation tank 33, and an intermediate door 60 adjustable in its opening degree is provided to the partition wall 31, between the column tank 32 and the heat accumulation tank 33. With this constitution, air which is in the column tank only is replaced at cooling, to store high temperature air of the heat accumulation tank at this time, and the opening degree of the intermediate door 60 at next analysis is adjusted to utilize this high-temperature air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromatographic analyzer such as a gas chromatograph analyzer and a gas chromatograph mass spectrometer, and more particularly, to a case where a chromatographic analysis is performed at a predetermined temperature (the temperature may be changed). In addition, the present invention relates to a column oven used for controlling the temperature of an analytical column.

[0002]

2. Description of the Related Art In gas chromatograph analysis and the like, an analytical column for separating a sample into components is used. Since the temperature of the analytical column is an important parameter in the analysis, the analytical column is generally installed in a column oven capable of controlling the temperature, and the temperature is controlled by the column oven.

FIG. 4 shows a schematic cross-sectional view of a conventional column oven for gas chromatography. The column oven 10 has a box structure in which six surfaces (up, down, left, right, front and back) are surrounded by heat insulating walls. A column 12 for analysis is attached to a space on the front side in the oven chamber 11, and the column 12 can be detached by opening a front door 14 formed on a front wall 13. A heater 15 and a fan 16 for improving temperature uniformity are mounted in a space on the rear side of the oven chamber 11. Fan 1
6 is connected to a drive motor 19 by a shaft 18 passing through a rear wall 17. A temperature sensor 20 is mounted near the column installation location of the oven chamber 11, and a control unit 21 provided with a temperature control circuit for controlling temperature by controlling a heater current based on a signal from the temperature sensor 20 is provided. Have been. The rear wall 17 of the column oven 10 is provided with a suction / discharge port 22 for sucking / discharging air, and an adjustment door 23 capable of adjusting an opening degree for adjusting a suction / discharge amount is attached. The adjusting door 23 is used for cooling the entire oven chamber 11 by taking in external air and discharging the internal high-temperature air when cooling is required. During the analysis, it is used to control the temperature by the balance between the heating by the heater 15 and the cooling by the suction of the outside air from the suction / discharge port 22. In addition,
In order to smoothly exchange the outside air and the air in the oven, the outside air sucked from the suction / discharge port 22 is guided to the fan 16 and the high-temperature air in the oven chamber 11 is easily guided to the suction / discharge port 22. A duct 24 is attached. That is, by forming the duct 24 so as to partition the intake side opening and the exhaust side opening of the intake and exhaust ports,
The fan 16 does not mix the sucked air with the hot air.
It is led to. In this example, the intake / exhaust port is provided in one place, but the intake / exhaust port may, of course, be separated into an intake side port and an exhaust side port and provided at different positions. For example, if the intake / exhaust port is formed so as to form the intake port at the back of the fan and the exhaust port at a position distant from the fan, the duct becomes unnecessary.

[0004] In gas chromatographic analysis, a temperature-raising analysis is sometimes performed to gradually increase the column temperature from the start to the end of the analysis so as to increase the detection sensitivity and the quantitative accuracy. In the temperature rise analysis, for example, analysis is performed in the following procedure. First, the initial temperature (80 ° C.) is maintained for a certain time after the start of the analysis. Then a certain percentage (1
(0 ° C./min) to elute the components to be analyzed sequentially by increasing the oven temperature. After that it is kept at the final temperature (250 ° C.) for a few minutes and the analysis is terminated.

[0005] When one analysis is completed by the above operation, the oven temperature is returned to the initial temperature, and the analysis is performed again. If necessary, the temperature is returned to room temperature, the analytical column is replaced, and the next analysis is performed. When the oven temperature is cooled from the final temperature (250 ° C.) to the initial temperature (80 ° C.), the inside and outside air are exchanged by fully opening the adjustment door 23 of the suction / discharge port 22. Wait until the oven temperature reaches the initial temperature, stabilize at the initial temperature, close the adjustment door 23, and start heating the heater 15 again. Temperature control is performed by adjusting the opening, and the next analysis is started when the temperature is stabilized at the initial temperature.

[0006]

Considering the volume of the oven chamber of the gas chromatograph, the minimum required for accommodating the column, the heater, and the fan (and the fan for homogenization) is necessary because the column needs to be mounted and heated. Volume is required. However, it is difficult to maintain the temperature of the entire column at a desired temperature even if the column or the like can be simply stored. Therefore, in practice, not only the minimum volume occupied by these but also a sufficient space is sufficient. It is necessary to keep a certain volume. Therefore, the volume of the oven chamber is usually designed to be about 10 liters or more.
About half of the space in the oven chamber is used as a column storage space, and the other half is used as a heater (and fan) storage space.

Incidentally, there is a case where the analysis is continuously performed as described above. If it is necessary to cool to the initial temperature for the next analysis after the previous analysis, once the high-temperature air in the oven chamber has been exhausted to the outside, the air in the volume is heated again. The operation of heating and maintaining the initial temperature is repeated. At this time, when the power consumed by the heater of the oven is measured, 1.3 to 2.
This value is about 1 kW, which is the value of the entire gas chromatograph (column oven, system controller, detector,
That is, it occupies most of the power consumed by the sample introduction section. Also, the time required to cool or heat the entire oven chamber tends to increase according to the volume of the column oven.

Therefore, in the present invention, in consideration of such a problem, the power consumption can be suppressed as much as possible, and the cooling time and the heating time of the column oven are shortened. As a result, from the start to the end of one analysis. It is an object of the present invention to reduce the required time for the continuous analysis and to improve the efficiency when performing the continuous analysis.

[0009]

According to the present invention, there is provided a column oven for chromatography, wherein a column for analysis is mounted in an oven chamber, and the column is controlled to a predetermined temperature by a temperature control mechanism. In a chromatographic column oven that performs chromatographic analysis, the oven chamber is separated into a column tank and a storage tank by a partition wall, and the column tank side is internally fitted with a column, column tank temperature sensor, fan, and opening adjustment An air intake / exhaust port is formed, and a heater and a storage tank temperature sensor are installed inside the storage tank, and a partition between the column tank and the storage tank can be adjusted in opening. Is provided.

In the column oven for chromatography of the present invention, the heat storage chamber and the column chamber are separated by closing the intermediate door when cooling the column. While the intermediate door is closed, the heat storage chamber is in a closed room surrounded by heat insulating walls, and heat is stored except for heat that is naturally radiated. On the other hand, by opening the air suction / discharge port on the column tank side, outside air enters and high-temperature air is discharged. As a result, only the column tank is cooled, and the space to be cooled can be a minimum necessary area. Furthermore, since there is no heater or the like having a large heat capacity in the column tank, cooling can be performed quickly.

After cooling is completed, when the column tank is subsequently heated, by opening the intermediate door, the high-temperature air stored in the storage tank can be flowed into the column tank, so that the column tank is quickly raised. It becomes possible to warm.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a schematic configuration diagram of a cross section of a column oven for chromatography according to one embodiment of the present invention. The column oven 30 has a box structure surrounded by heat-insulating walls at the top, bottom, left and right, and the inside is separated into a column tank 32 and a heat storage tank 33 by a partition wall 31 formed of a heat insulating material.

In the column tank 32, in addition to the column 33, a fan 34 for promoting air circulation in the column tank 32 and for equalizing the temperature while being installed near the column 12 to monitor the column temperature. Temperature sensor 35 is attached. The column 12 can be detached by opening a front door 37 formed on the front wall 36. A motor 38 for rotationally driving the fan 34 is attached to the outside of the box forming the oven, and is rotated via a drive mechanism connected by a plurality of shafts 39 and joints 40 so as to crawl on the bottom of the box outside. The force is transmitted to the fan 34. A suction / discharge port 41 for exchanging air inside and outside is formed in a part of the side wall (the left side wall in the figure) on the column tank side, and an adjustment door 42 for adjusting the opening is attached to the suction / discharge port 41. And column tank 32
A duct 43 is attached in consideration of the flow of gas inside. That is, the duct 43 is formed such that the outside air flowing from the suction / discharge port 41 flows toward the fan 34 and the air near the column 12 in the column tank 32 is discharged toward the suction / discharge port 41. You.

A heater 51 and a temperature sensor 52 for monitoring the temperature of air in the tank are mounted in the storage tank 33. As a position of the temperature sensor, it is preferable to install the temperature sensor in the vicinity of an intermediate door described later for the purpose of measuring the temperature of the air sent into the column tank 32. In addition, animal heat tank 33
It is desirable to provide a fan 53 for the heat storage tank for the purpose of equalizing the temperature by stirring the air temperature inside. The fan 53 is connected to the motor 54 by a shaft 56 penetrating through the rear wall 55 and is provided with a rotational force. In the drawing, separate motors are used for the two fans, respectively. However, one motor may be shared by branching the power transmission mechanism to the shaft into two.

An intermediate door 60 is formed on a part of the partition 31. The opening of the intermediate door 60 can be adjusted, and the amount of air movement between the column tank 32 and the heat storage tank 33 can be adjusted by changing the opening. Reference numeral 61 denotes a control unit for controlling the entire column oven 30. The controller 61 is connected to the temperature sensors 35 and 52, the heater 51, the adjustment door 42, and the intermediate door 60, and controls these, and also controls the rotation speed of the fans 34 and 53.

Next, the operation of the temperature rising analysis using this apparatus will be described with reference to FIGS. In these figures, only the components necessary for the explanation of the operation are shown for convenience.

(1) Initial temperature rise When the apparatus is started from the stopped state and the first analysis is performed, the intermediate door 60 is opened as shown in FIG.
Is closed. In this state, the fan 34 is rotated, and the heater 51 is turned on. At this time, the temperature sensor 35 on the column tank 32 and the temperature sensor 52 on the storage tank 33 are monitored. The temperature sensor 52 monitors the storage tank 33 so as not to become abnormally high. On the other hand, since the temperature sensor 35 indicates the column temperature, feedback control is performed so that this temperature is finally stabilized at the set temperature. When the temperature of the column-side temperature sensor 35 becomes close to the set temperature from the room temperature, the operation of adjusting the opening of the adjustment door 42 starts. That is, when the temperature sensor 35 detects that the temperature has become higher than the set temperature due to excessive heating, the adjustment door 4
2, and the opening of the intermediate door 60 is reduced. Conversely, when the temperature sensor 35 detects that the temperature is lower than the set temperature, the opening degree of the adjustment door 42 is reduced and the opening degree of the intermediate door 60 is increased. By these operations, the temperature of the column tank is maintained at a constant temperature. Then, by continuing the temperature adjustment operation, the first analysis operation is started when the column bath temperature is stabilized. In the case of heating analysis,
The analysis is performed while gradually increasing the current of the heater 51 and controlling the temperature to a desired temperature by the balance between the opening degrees of the intermediate door 60 and the adjustment door 42. Fan 3 during analysis operation
Since the rotation of 4 is continued, the inside of the column tank 32 is maintained at a uniform temperature.

(2) Temperature drop When the first analysis operation is completed, cooling for starting to the initial temperature is started in preparation for the next analysis. At this time, as shown in FIG. 3, the intermediate door 60 is fully closed, and the adjustment door 42 is fully open. The fan 34 is rotated to take in low-temperature outside air and exhaust high-temperature air in the column tank 32. Although the inside and outside air can be exchanged only by the rotation operation of the fan 34, the efficiency of the air exchange can be improved by installing the duct 43. At the time of temperature decrease, the heater 51 is not used and thus is turned off. Since the entire heat storage tank 33 is surrounded by the heat insulating wall, the temperature of the heat storage tank is maintained at a high temperature close to the final temperature at the end of the previous analysis to the extent that a slight temperature drop occurs due to natural cooling. The temperature of the heat storage tank at this time is monitored by the temperature sensor 52. From the viewpoint of power saving, it is desirable to turn off the heater. However, in special cases such as when the next analysis condition is started at a considerably high temperature, the heater should be turned on and the higher temperature air must be turned on. Can also be stored in a heat storage tank.

(3) Temperature rise after the second time When the temperature rise is started in preparation for the second and subsequent analyses, the adjustment door 42 is closed as shown in FIG.
Set 0 to the opening adjustment state. The indicated value (S1) of the temperature sensor 52 of the storage tank and the indicated value of the temperature sensor 35 (S
The temperature is compared with that in 2), and the operation is performed as follows based on the result. First, for some reason, when the temperature of the heat storage tank has been sufficiently lowered and S1 ≦ S2, the intermediate door 60 is fully opened, the heater is turned on, and the temperature of the column tank 32 is increased by the heater power. Control. This case is almost the same as (1) described above. If S1>
In the case of S2, since sufficient heat is accumulated in the heat storage tank 33, the heater 51 is maintained in the OFF state, the opening of the intermediate door 60 is adjusted, and the high temperature flowing from the heat storage tank 33 to the column tank 32 is maintained. The temperature of the column tank 32 is controlled by adjusting the amount of air. In the example shown in FIG. 3, the fan is not attached to the storage tank, but even if the fan is not installed, the diffusion effect due to the temperature difference between the storage tank and the column tank or the inside of the column tank 34 It is possible to draw sufficiently high temperature air into the column tank 32 by the provided fan 34. Next, during the temperature rise, from the S1> S2 state to S1 ≒ S
When the state becomes two, the control method is switched from the opening / closing control of the intermediate door to the control by the heater power. That is, since the excess heat stored in the heat storage tank at that time is being consumed, it is no longer possible to transfer the heat to the column tank, so the control is switched to the normal heater control. .

In this way, while the heat stored in the air in the storage tank can be used, the column tank is heated by using this heat, and when it cannot be used, the temperature is controlled by the heater as usual. I do. In the embodiment shown in FIG. 1, the intermediate door 60 is provided at the corner of the partition wall 31. However, the present invention is not limited to this. High-temperature air may easily flow in.

The embodiments of the present invention will be summarized below. (1) A column for analysis is installed in the oven chamber, and the column is controlled to a predetermined temperature by a temperature control mechanism to perform chromatographic analysis. Separated, the column tank side has a column, a column tank temperature sensor and a fan mounted inside, and an air intake / exhaust port whose opening can be adjusted is formed.The heat storage tank side has a heater and a heat storage tank temperature sensor inside, A column oven for chromatographic analysis, wherein a second fan is attached, and an intermediate door whose opening is adjustable is provided on a partition wall between the column tank and the heat storage tank. (2) In a chromatographic column oven in which a column for analysis is mounted in an oven chamber and the column is controlled to a predetermined temperature by a temperature control mechanism to perform chromatographic analysis, the oven chamber is divided into a column tank and a storage tank by a partition wall. Separated, the column tank side has a column, column tank temperature sensor, and a fan mounted inside, and an air intake / exhaust port whose opening can be adjusted is formed on the wall surface of the column tank. A duct that guides to the fan and guides the air in the column tank to the exhaust port is installed, and a heater and a storage tank temperature sensor are installed inside the storage tank side, and a partition wall between the column tank and the storage tank is installed. A column oven for chromatographic analysis, characterized in that an intermediate door whose opening can be adjusted is provided on the column oven.

[0022]

As described above, in the chromatographic column oven of the present invention, the oven chamber is separated into a heat storage tank and a column tank by the partition walls, so that the heat used during the previous analysis is stored. Can be used for heating for the next analysis, which can contribute to power saving. Furthermore, the cooling time and the heating time of the column tank can be reduced, and the time required for one analysis can be reduced, so that the analysis efficiency can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic configuration of a column oven for chromatographic analysis which is one embodiment of the present invention.

FIG. 2 is a diagram showing a state when a temperature is raised in the present invention.

FIG. 3 is a diagram showing a state when the temperature is lowered in the present invention.

FIG. 4 is a diagram showing a schematic configuration of a conventional column oven for chromatography.

[Explanation of symbols]

 12: Column 30: Column oven 31: Partition wall 32: Column tank 33: Heat storage tank 34: Fan 35: Temperature sensor (for column tank) 51: Heater 52: Temperature sensor (for heat storage tank) 53: Fan (for heat storage tank) 60: Intermediate door 61: Control unit

Claims (1)

[Claims] 1. A chromatographic column oven in which a column for analysis is mounted in an oven chamber and the column is controlled to a predetermined temperature by a temperature control mechanism to perform chromatographic analysis. The column tank side has a column, a column tank temperature sensor and a fan mounted inside, and an air intake / exhaust port whose opening can be adjusted is formed.The storage tank side has a heater and storage tank temperature inside. A column oven for chromatographic analysis, wherein a sensor is mounted, and an intermediate door whose opening is adjustable is provided on a partition wall between the column tank and the heat storage tank.