JPH08160026A - Oven for controlling temperature of column - Google Patents

Abstract

PURPOSE: To perform stable temp. control by providing an annular space housing a separation column in an oven main body housing the separation column wound in an annular shape and introducing cooled N2 gas into the oven main body as a temp. control medium. CONSTITUTION: A separation column 4 wound in an annular shape is housed in the internal space 3 of an oven main body 2 formed into a ring shape. The branch cooling medium pipes 51-53 branched from the cooling medium introducing pipe 5 passing through a Dewar vessel 7 storing liquid N2 are connected to the lower part of the main body 2 to communicate with the space 3. The introducing pipe 5 receives the supply of N2 gas from the outside to introduce the N2 gas into the vessel 7. The introducing pipe 5 is allowed to communicate with the bypass 5a led out of the upper part 7a of the vessel 7 in the front stage thereof to also introduce the N2 gas gasified in the vessel 7 to efficiently form the N2 gas to introduce the same into the space 3. A piezoelectric valve 9 adjusts the flow rate of the N2 gas introduced into the introducing pipe 5 from the outside. A temp. controller 10 sends out control output to the valve 9 on the basis of the temp. data from a temp. sensor 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column temperature control oven used for gas chromatographic analysis.

[0002]

2. Description of the Related Art Conventionally, an oven using liquid CO ₂ or liquid N ₂ as a cooling medium has been used to cool a separation column in gas chromatographic analysis. For example, as shown in FIG. 7, the oven 1 has an internal space 3 of a heat insulating container (oven body) 2 formed in a rectangular box shape by plate members sandwiching a heat insulating material such as fine flex.
Further, the ring-shaped separation column 4 is housed in a suspended state, and liquid CO ₂ or liquid N ₂ is introduced from the refrigerant introduction pipe 5 into the internal space 3 thereof. This is performed by cutting off the supply of the liquid refrigerant by an on-off valve (not shown). Reference numeral 6 is a detector.

[0003]

In the above-mentioned conventional oven 1, since the liquid is used as the refrigerant, the on / off control is intermittently performed with the vaporization phenomenon in the inside thereof, and the cooling temperature becomes unstable. Easy and precise temperature control was not easy.

Further, since the internal space 3 of the oven 1 has a rectangular shape, a large dead space is generated between the inner space 3 of the oven 1 and the separation column 4 wound in a ring shape, the cooling efficiency is low, and the consumption of the refrigerant is extremely large. There were some difficulties.

The present invention has been made in view of such circumstances.
It is an object of the present invention to provide a column temperature control oven which can perform stable temperature control with high accuracy and consumes less refrigerant.

[0006]

The present invention has means for solving the above-mentioned problems as follows. That is, in the invention according to claim 1, the oven main body for accommodating the separation column wound in a ring shape is formed in a ring shape having an annular space for accommodating the separation column therein. It is characterized by becoming.

According to a second aspect of the invention, the temperature control medium introduced into the oven body according to the first aspect is liquid N ₂
It is characterized in that it is a cold gas N ₂ that has undergone heat exchange with.

The invention according to claim 3 is characterized in that a piezo valve is used as means for adjusting the flow rate of the cold gas N ₂ of the oven main body according to claim 2.

The invention according to claim 4 is characterized in that a temperature-adjustable heater is provided in the central space of the oven body according to any one of claims 1 to 3.

[0010]

In the invention described in claim 1, the ring-shaped separation column is housed in the ring-shaped space of the oven main body, so that a dead space is not generated.
The oven body is compact, and highly efficient temperature control can be performed.

According to the second aspect of the present invention, by using the cold gas N ₂ as the refrigerant, the flow rate can be adjusted easily and surely, and highly accurate temperature control can be performed.

According to the third aspect of the invention, by using a piezo valve as the flow rate adjusting means for the cold gas N ₂ ,
The flow rate can be adjusted continuously from 0 to 100%, and highly accurate temperature control can be performed.

According to the fourth aspect of the invention, the temperature controllable heater makes it possible to control the temperature over a wide range from the normal temperature to the high temperature range.

[0014]

Embodiments of the column temperature control oven of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows the configuration of a column temperature control oven 1. Reference numeral 2 is an oven main body formed in a ring shape, and a ring-shaped separation column wound in a ring-shaped internal space 3 formed in the main body 2. Holds 4. At the bottom of the oven body 2, liquid N
Refrigerant introduction pipe 5 via Dewar bottle 7 that stores ₂
Three branched refrigerant pipes 51, 52, 53 branched from are connected to each other and communicate with the internal space 3.

The refrigerant introduction pipe 5 is supplied with gas N ₂ from the outside and is communicated with a bypass 5a led out from an upper portion 7a of the dewar bottle 7 before being introduced into the dewar bottle 7, whereby the dewar is introduced. N ₂ vaporized in bottle 7
Can also be introduced into the refrigerant introduction pipe 5 to efficiently generate the cold gas N ₂ and introduce it into the internal space 3.

Reference numeral 9 is a piezo valve for adjusting the flow rate of the gas N ₂ introduced from the outside into the refrigerant introduction pipe 5.
The flow rate can be continuously adjusted from 0 to 100%. A temperature controller 10 sends a control output for temperature adjustment to the piezo valve 9 according to a preset control program based on temperature information from a temperature sensor 11 provided in the internal space 3 of the oven body 2.

As described above, since the gas N ₂ is controlled, the flow rate can be easily and reliably adjusted by the piezo valve 9, and the separation column 4 is housed without leaving a dead space in the internal space 3. Therefore, the oven main body 2 is made compact, high cooling efficiency is obtained, and stable and highly reliable temperature control is possible.
The suitable temperature control range is about -90 ° C to 18 ° C.

[0018] Then, by the bypass 5a, can also be incorporated as a refrigerant a cold body N ₂ vaporized in the dewar bottle 7, it is possible to efficiently generate the cold body N _2, synergy with high cooling efficiency This significantly reduces the consumption of refrigerant.

Explaining in more detail, the oven main body 2
2 to 4, it is composed of an upper part 21 and a lower part 22 which are integrated by bolt fastening, and is projected on the upper part 21 in a deep groove 22a dug in the lower part 22. The separation column 4 wound around the support pins p, ... Is fitted. Therefore, when assembling, as shown in FIG. 5, first, the support pins p,
The separation column 4 is wound around the ... And after the separation column 4 is fitted into the concave groove 22a of the lower portion 22 in the wound state,
The upper part 21 and the lower part 22 may be integrated by fastening the bolts s. The lower portion 22 may be made of a metal material such as Al alloy or stainless steel, and the upper portion 21 may be made of a resin material.

On the bottom surface of the lower portion 22 of the oven main body 2, there are provided connection ports a, ... For connecting the respective branch refrigerant pipes 51, 52, 53. As shown in FIG. It communicates with a jet port c that opens in the internal space 3 through a through hole b that is formed in the upper side. The cold gas N jetted from the jet port c through such a diagonal through hole b.
₂ becomes a swirl flow in the internal space 3 and evenly spreads to every corner in the internal space 3, so that the cooling effect on the separation column 4 can be remarkably improved. In addition, a small hole for opening to the atmosphere (φ1.8
mm) h is formed.

FIG. 6 shows a different embodiment, in which a coil-shaped heater 91 is operated in the central space of the oven main body 2 by the control output from the temperature controller 10 without providing a flow rate adjusting means for the cold gas N _2. Is provided, and the temperature of the separation column 4 can be controlled by the heater 91. In this case, the upper limit of the temperature control range is expanded, and the upper limit value is set to 70, for example.
It can be set to about ℃. In this case, it is preferable that both the upper part 21 and the lower part 22 of the oven main body 2 are made of a heat-resistant metallic material or a non-metallic material.

[0022]

As described above, according to the first aspect of the present invention, the oven body is formed in a ring shape having an annular space for accommodating the separation column therein, so that the oven body is compact. And highly efficient temperature control can be performed.

According to the second aspect of the invention, since the cold gas N ₂ is used as the refrigerant, the flow rate thereof can be easily and reliably adjusted, and highly accurate and stable temperature control can be performed.

According to the third aspect of the invention, since the piezo valve is used as the flow rate adjusting means of the cold gas N ₂ , 0 to 1 is used.
The flow rate can be adjusted continuously up to 00%, and highly accurate temperature control can be performed.

According to the fourth aspect of the present invention, the temperature controllable heater enables temperature control over a wide range from normal temperature to a high temperature range.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a column temperature control oven of the present invention.

FIG. 2 is a plan view of the upper part of the oven main body.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view showing a state in which a separation column is wound around the upper part of the oven body.

FIG. 5 is a partially enlarged perspective view of the lower portion of the oven main body.

FIG. 6 is a configuration diagram of another embodiment of the column temperature control oven of the present invention.

FIG. 7 is a configuration diagram showing an example of a conventional column temperature control oven.

[Explanation of symbols]

2 ... Oven body, 3 ... Space, 4 ... Separation column, 9 ... Piezo valve.

Claims (4)

[Claims] 1. An oven main body for accommodating a separation column wound in a ring shape is formed in a ring shape having an annular space for accommodating the separation column therein. Column temperature control oven. 2. A temperature control medium is introduced into the oven body, the column temperature control oven according to claim 1, characterized in that a cold body N ₂ that has exchanged heat with liquid N _2. 3. The column temperature adjusting oven according to claim 2, wherein a piezo valve is used as a means for adjusting the flow rate of the cold gas N ₂ . 4. The column temperature control oven according to claim 1, wherein a heater capable of temperature control is provided in a central space of the oven body.