JPS62261059A - Column induction heater for chromatograph - Google Patents

Abstract

PURPOSE:To achieve a higher reproducibility of retention time, by providing a metal member made of a ferromagnetic material for retaining a column with an induction coil which is energized by a current enough to heat at a Curie temperature thereof to eliminate variations in the temperature adjusting accuracy. CONSTITUTION:A capillary column 2 is retained on an internal surface of metal plates 1a and 1b which are mainly composed of a ferromagnetic material such as iron, nickel and cobalt and are adapted to obtain a desired Curie temperature varying the composition ratio or the like with other metals while induction coils 4a and 4b to be energized by AC from a power source 5 are provided on the external surface thereof so as to heat the metal plates 1a and 1b at a Curie temperature thereof. Then, as an AC is supplied to coil 4a and 4b, a magnetic flux is applied to the metal plates 1a and 1b, which are heated and elevated in the temperature by a heat generated by an eddy current loss and a ferromagnetic hysteresis loop loss. When a Curie temperature is reached, the metal plates 1a and 1b lose a ferromagnetic property to become paramagnetic and the heating due to the eddy current loss and the paramagnetic hysteresis loop loss maintains the temperature. Thus, the column 2 is kept at the Curie temperature of the metal plates 1a and 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application for a business owner) The present invention relates to an apparatus for induction heating a column in a gas chromatograph or a liquid chromatograph.

(Prior art) In a chromatograph column for sequentially separating and eluting each sample component, a fan blows in air heated by an electric heater or the like that is controlled at a constant temperature to bring the inside of the column oven to the desired temperature. It had already been heated.

(Problems to be Solved by the Invention) However, according to the above-mentioned apparatus, an indirect heating method is adopted in which heated air is sent into a spatially expanding column oven using a fan, and the temperature inside the oven is brought to a target temperature. , it is difficult to maintain a uniform target temperature inside the column oven, so the rotation speed of the fan must be adjusted to stir the heated air at high speed, or the insulation performance of the insulation material must be adjusted to prevent heat leakage. There are problems such as having to perform various troublesome temperature adjustment operations such as improving the temperature, and also having to perform the above-mentioned operations for each column oven because the temperature characteristics differ from column oven to column oven.

(Purpose) The present invention was made in view of the above problem, and its purpose is to directly conduct heat generated by a heating source to a column and heat the column to a target temperature without performing troublesome temperature adjustment work. The object of the present invention is to provide a new column induction heating device M that can be used in a white column.

(Summary of the present invention) A column is held by a plurality of metal members made of ferromagnetic material, and an induction coil energized by a current capable of heating the column at the Curie temperature of the metal member is provided in the metal member, The alternating magnetic flux induced from this induction coil is applied to the metal member, and the column is heated by the heat generated by the eddy current loss generated in the metal member and the hysteresis loop loss of the ferromagnetic material, and when it reaches the Curie temperature, the metal member becomes stronger. It loses its magnetism and becomes paramagnetic, and heating occurs due to eddy current loss and paramagnetic hysteresis loop loss.

(Example) The details of the present invention will be explained below based on the illustrated example.

Figures 1 to 3 show an example of the column induction heating device in a chromatograph according to the present invention applied to a gas chromatograph. It is a metal plate configured to obtain a desired Curie temperature by changing the composition ratio with other metals, and has a meandering groove 3 bored on its inner surface. A capillary column 2 is held, one end of which is connected to a sample vaporization chamber (not shown), and the other end of which is connected to a detector (also not shown). The metal plates 1a, 1b have metal plates 1a, 1b on their outer surfaces.
induction coils 4a, 4b energized by an alternating current from an alternating power supply 5 capable of heating b to its Curie temperature;
is provided.

In the device configured in this manner, when an alternating current from an alternating power supply 5' is supplied to the induction coils 4a and 4b, the magnetic flux generated from these coils 4a and 4b is applied to the metal plates 1a and 1b.
As a result, an eddy current loss flows in the metal plates 1a and 1b to generate magnetic flux in a direction that cancels out the above magnetic flux, and as shown in FIG. 5, the ferromagnetic hysteresis loop loss h1 of the metal plates 1a and 1b When the heating temperature of the metal plates 1a and 1b reaches the Curie temperature Tc, the metal plates 1a and 1b lose their ferromagnetism and become paramagnetic, which causes an eddy current. Loss and metal plate 1a, 1
The metal plate 1 is heated and maintained at this temperature by the paramagnetic hysteresis loop loss h2 of b (Fig. 4).
If the temperature of metal plates 1a and 1b decreases even slightly below the Curie temperature Tc due to a decrease in the ambient temperature of the device, the metal plates 1a and 1b
b becomes ferromagnetic again and is heated by eddy current loss and ferromagnetic hysteresis loop loss h1 to reach the Curie temperature T again.
c and is heated again by eddy current losses and paramagnetic hysteresis loop losses h1, and the column 2 is maintained at this temperature.

What is shown in FIG. 6 shows another embodiment of the present invention applied when the column length is long.
) is formed with a double meandering groove (not shown) on the inner surface thereof, and a capillary column 62 formed in a double meandering manner is held in this groove. According to the apparatus described in this example, multiple pairs of metal plates with different Curie temperatures are prepared, and when it is desired to change the column temperature, it is possible to change the column temperature by replacing the pair with a pair of metal plates suitable for that temperature. In addition, multiple pairs of metal plates with different Curie temperatures are installed in the oven, making it possible to simultaneously analyze multiple samples at different column temperatures. It can also be applied to column heating.

Also, by extending the sample vaporization chamber block connected to one end of the capillary column and the detector block connected to the other end,
By contacting the metal plate to conduct the heat generated by the metal plate, it is also possible to omit the opening for heating the sample vaporization chamber and detector, and when using the capillary column for cold injection, that is, to conduct the heat generated by the metal plate. It can also be applied to the case where a hot sample is sent to a capillary column and each sample component is separated and eluted during the heating process until the column reaches the Curie temperature.

(Effects) As described above, according to the present invention, a column is held by a metal member made of a ferromagnetic material, and an induction coil energized by an electric comb that can be heated at the Curie temperature is provided on this metal member. Therefore, the metal member is heated at the Curie temperature, and the generated heat is directly conducted to the column, which allows the column to be uniquely heated at the Curie temperature, thus eliminating the need for troublesome temperature adjustment work. In addition, variations in temperature adjustment accuracy are eliminated, each sample component is separated and eluted, and the reproducibility of tension time is improved.
Furthermore, there is no need to individually adjust the temperature for each heating device.

[Brief explanation of drawings]

Fig. 1 shows a column induction heating device M in a chromatograph of the present invention with an example of application to a gas chromatograph.
An exploded perspective view of the device, Figure 2 is the same device as above! Fig. 3 is an electrical circuit diagram of the same device, Fig. 4 is a graph showing the relationship between heating time and Curie temperature by the above device, and Fig. 5 shows the ferromagnetism and paramagnetism of the metal plate of the above device. FIG. 6 is a perspective view showing another embodiment of the present invention for holding a capillary column. 1a, 1b...metal plate 2...capillary column 4a, 4b...induction coil

Claims (1)

[Claims] a plurality of metal members made of a ferromagnetic material; a column held by the metal member; and an induced current provided in the metal member and capable of heating the column at the Curie temperature of the metal member. A column induction heating device for a chromatograph, characterized by comprising an induction coil.