JPH067061U - Gas chromatograph - Google Patents

Abstract

(57) [Summary] [Purpose] By combining each column as a unit, it is possible to easily perform column combination, mounting, removal, and replacement work. [Structure] A column structure 43 is fitted around the outer peripheries of a substrate 40 and an upper lid 41 that form the sample valve 20. The column structure 43 includes a cylindrical case 44 and three column units 45, 4 coaxially fitted to the outer circumference of the case 44.
6, 47, a cover 48 and a lid 49. The column unit 45 is composed of a cylindrical bobbin and a column 21A wound around the outer circumference thereof. Similarly, the column units 46 and 47 also have a bobbin and a column (21
B, 21C). When replacing the column, each column unit is replaced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas chromatograph in which a column is filled with a packing material as a stationary phase and the gas analysis is performed by utilizing the difference in the adsorptivity between the packing material and the gas.

[0002]

[Prior art]

 In a process gas chromatograph, a column used for separating gas components is usually wound around an outer peripheral surface of a bobbin as shown in FIGS. 7 and 8. That is, 1, 2 and 3 are columns, 4 is a bobbin, and this bobbin 4 is formed in a cylindrical shape and integrally has flange portions 4a and 4b on both outer peripheral surfaces, and the outer periphery between these flange portions is formed. The columns 1, 2 and 3 are wound on the surface so as to be juxtaposed in the axial direction. Then, the inner peripheral side end portions 1a, 2a, 3a of the columns 1, 2, 3 are guided in the axial direction along the outer peripheral surface of the bobbin 4 and the outer ends of the columns 1, 2, 3 from the one end portion of the bobbin 4. Have been derived respectively.

[0003]

[Problems to be solved by the device]

 However, in the above-described conventional column mounting structure, the columns 1, 2, and 3 are wound hierarchically on the outer peripheral surface of the bobbin, and the inner peripheral end 2a of the second column 2 is connected to the first column. It is passed under the innermost peripheral annular portion 1b of the column 1, and the inner peripheral end 3a of the third column 3 is connected to the innermost peripheral annular portion 1b of the first column 1 and the second column 2. Since it passes under the innermost annular portion 2b, when exchanging a deteriorated column, the columns other than the uppermost column 1 cannot be exchanged unless the upper columns are removed, resulting in remarkable workability. There was a problem of being bad.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and the purpose thereof is to combine, install, remove, and replace columns by unitizing each column. It is to provide a gas chromatograph that enables easy work.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a plurality of column units in which a sample valve is arranged on a substrate containing a heater, and a column is wound around a cylindrical bobbin having a different diameter around the sample valve. Is fitted coaxially.

[0006]

[Action]

 In the present invention, each column is wound on a bobbin of different diameter to form a column unit. The column units are fitted on the outer circumference of the sample valve in order of decreasing bobbin diameter. When exchanging a column, the column unit is exchanged.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a schematic configuration diagram of a gas chromatograph according to the present invention, in which 11 is an analyzer main body and 13 is a controller. The analyzer main body 11 is provided with a constant temperature bath 14 which is heated and maintained at a predetermined temperature (about 60 ° C. to 120 ° C.) by a heater 60 described later, and inside the constant temperature bath 14, a measuring pipe 19 and a sample valve 20 are provided. , Column 21 and detector 22 are provided. The analyzer main body 11 is housed in the pressure-proof explosion-proof container 23 so that the analyzer body 11 is explosion-proof. In addition, 18 is a pressure reducing valve for adjusting the pressure of the carrier gas C G. By holding the flow path of the sample valve 20 in a solid line during non-measurement, the carrier gas CG made of an inert gas such as helium supplied from the first carrier gas inlet 24 is detected through the column 21. While flowing into the container 22, the sample gas SG introduced from the sample gas introduction port 25 is discarded through the measuring pipe 19 and the vent port 26. When the flow path of the sample valve 20 is switched from the solid line state to the broken line state during measurement, the sample gas SG collected by the measuring pipe 19 is introduced into the column 21 by the carrier gas CG introduced from the second carrier gas introduction port 27. Sent in. The column 21 is packed with powder having a uniform particle size, such as activated carbon, activated alumina, and molecular sieve, as the stationary phase, which varies depending on the sample gas SG. The stationary phase and each gas component in the sample gas SG The gas components are separated from each other by using the difference in the moving speed based on the difference in the adsorbability and distribution coefficient of the gas, and this is detected by the detector 22 such as a thermal conductivity detector or hydrogen flame ionization detector, and the electrical signal is detected. Convert to. This electric signal is proportional to the gas component concentration, and is waveform-processed by the controller 13 to monitor or record the process step. Although only one column 21 is shown in FIG. 1, a plurality of columns are used depending on the composition of the sample gas SG.

Next, the sample valve, the mounting structure of the column and the like will be described in detail with reference to FIGS. 2 is a cross-sectional view of the sample valve and the column structure, FIG. 3 is a bottom view of the substrate, FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a front view of the column unit with a part omitted, and FIG. 6 is a bobbin. FIG.

In FIG. 2, the sample gas flow path formed inside and the carrier gas flow path (flow paths a to f shown by the solid line and the dotted line in FIG. 1) are switched to detect the sample gas SG during measurement. As the sample valve 20 which guides the carrier gas CG to the detector 22 when it is not measured, a conventionally known pneumatically driven diaphragm valve is used. This sample valve 20 includes a center plate 30, a plurality of plungers 34A, 34B, ..., Plungers 34A, 34B ,. Slidingly guides and holds the lower plunger plates 35, 36 and the plungers 34A, 34B ... Alternately operated, and lower pistons 37, 38 and return springs 39 for the pistons 37, 38. , A plunger 40A, 34B, ..., Plunger plates 35, 36, pistons 37, 38, a return spring 39, etc., and a base plate 40, an upper lid 41, etc., which are arranged opposite to each other with the center plate 30 interposed therebetween. ing. Then, the sample valve 20 is housed in a concave portion opened to the upper surface of the substrate 40, and is covered by the upper lid 41. A plurality of fluid passages (FIGS. 1a to 1f) are formed on the front and back surfaces of the center plate 30 so as to penetrate the same circumference, and the plungers 34A, 34B ...・ Is provided. When the upper and lower plungers 34A, 34B, ... Are alternately operated by the pistons 37, 38 to release the pressing states of the diaphragms 31, 32 alternately, the sample gas SG and the carrier gas CG gas supplied to the sample valve 20 are supplied. The upper and lower diaphragms 31 and 32 are elastically deformed alternately by the pressure, and the upper route and the lower route of the fluid passages a to f are alternately switched. That is, the sample valve 20 employs a system in which the diaphragm on the plunger OFF side is elastically deformed by the gas pressure to switch between the lower route and the upper route of the fluid passages a to f so that the fluid flows. The outer circumference of the sample valve 20 is covered with the column structure 43 including the column 20, and the heater 60 is built in the substrate 40.

The column structure 43 includes a cylindrical case 44 fitted to the outer peripheral surfaces of the substrate 40 and the upper lid 41, and three column units 45 and 46 coaxially fitted to the outer circumference of the case 44. , 47, and a cover 48 and a lid 49 fitted to the outside thereof. The case 44 is formed in a tubular body with both ends open, has a flange 44A integrally at the lower end of the outer peripheral surface, and is fitted on the outer peripheral surfaces of the substrate 40 and the upper lid 41. The flange 44A is in close contact with the upper surface of the lower end portion of the substrate 40 and is fixed by a set screw or the like. As shown in FIGS. 5 and 6, the column unit 45 is composed of a bobbin 50 having a cylindrical body whose both ends are open, and a first column 21A wound around the outer circumference of the bobbin 50. The bobbin 50 has an inner diameter that is substantially equal to or slightly larger than the outer diameter of the case 44, and two column storage grooves 51a and 51b that extend over the entire length in the height direction are formed on the outer peripheral surface at appropriate intervals in the circumferential direction. ing. The respective end portions 21a and 21b of the first column 21A wound around the outer peripheral surface of the bobbin 50 are guided upward through the column storage grooves 51a and 51b, and a predetermined connection is opened on the upper surface of the sample valve 20. Each is connected to the mouth via a nipple 52. When winding the column 21A, one end 21a of the column 21A is inserted into one of the column storage grooves 51a from above and drawn out from the vicinity of the lower end of the column storage groove 51a to the outside of the bobbin 50 from the bottom to the top. If the column 21A is long, the column 21A may be wound in double or triple, and the other end 21b may be inserted into the upper end of the other column storage groove 51b and guided upward. When such column storage grooves 51a and 51b are provided, when the column 21A is wound around the bobbin 50, the column portion that intersects the one end 21a does not float up from the outer peripheral surface of the bobbin, and the column is not bent or dented. It has the advantage that it can be prevented. Then, the column unit 45 thus configured is fitted on the outer periphery of the case 44 and placed on the flange 44A. It is desirable that the case 44 and the bobbin 50 are in close contact with each other in order to improve heat conduction. The other column units 46 and 47 have exactly the same configuration except that the inner and outer diameters of the bobbin are different from those of the column unit 45 described above, and the description thereof will be omitted. The cover 48 is fitted on the outer circumferential surface of the outermost column unit 47 after fitting the column units 45, 46, 47 in the ascending order, and then fitted on the outer circumference of the outermost column unit 47, after which the upper end opening is covered with a lid 49. Be seen.

In such a column structure 43, the column units 45, 46, 47 are preassembled, and the case 44 is fitted and fixed to the sample valve 20 and then sequentially fitted to the outer periphery of the case 44 in ascending order. Then, each end of each column 21A, 21B, 21C is connected to the sample valve 20, and then covered with a cover 48 and a lid 49. When replacing a column due to deterioration, change of measurement target, etc., the cover 48 and the lid 49 are removed, the column units 45, 46, 47 are once removed from the case 44, and the column to be replaced is replaced with a new column unit. And assemble it to the original state. Therefore, the column replacement work is significantly simpler and easier than the conventional device shown in FIGS. 7 and 8.

2 to 4, a heater 60 for heating and keeping the sample valve 20 and the columns 21 (21A, 21B, 21C) at a constant temperature is incorporated inside the substrate 40, and the lower surface of the substrate 40 is also provided. Has a groove 61 for accommodating and fixing the measuring pipe 19. The groove 61 is composed of two vertical holes 61a and 61b penetrating the upper and lower surfaces of the substrate 40, and a communication groove 61c which is formed in the lower surface of the substrate 40 and connects the lower end openings of the two vertical holes 61a and 61b. By doing so, the cross-sectional shape is U-shaped, and the upper end openings of the vertical holes 61a and 61b are connected to one ends of the fluid passages c and d (FIG. 4), respectively. The measuring pipe 19 is formed by bending a thin pipe having a length of 60 mm, an outer diameter of 1.6 mm and an inner diameter of 0.8 mm into a U-shape, and both ends thereof are inserted into the vertical holes 61 a and 61 b through the bush 62, respectively. The central portion is fixed to the groove bottom surface of the communication groove 61c by one set screw 63.

[0013]

[Effect of device]

 As described above, according to the gas chromatograph according to the present invention, a plurality of column units in which columns are wound around cylindrical bobbins having different diameters are coaxially fitted around the outer circumference of the sample valve. Therefore, when mounting and replacing the column, it is sufficient to mount and replace each column unit, and therefore, the column mounting work and the replacement work can be remarkably easy and the workability can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a gas chromatograph according to the present invention.

FIG. 2 is a cross-sectional view of a sample valve and a column structure.

FIG. 3 is a bottom view of the substrate.

4 is a sectional view taken along line IV-IV of FIG.

FIG. 5 is a front view of a column unit.

FIG. 6 is a plan view of the bobbin.

FIG. 7 is a front view showing a conventional bobbin.

FIG. 8 is a diagram showing column intersections.

[Explanation of symbols]

 20 sample valve 21 column 22 detector 40 substrate 43 column structure 44 case 45, 46, 47 column unit 50 bobbin 48 case 60 heater

Claims (1)

[Scope of utility model registration request] 1. A sample valve is arranged on a substrate containing a heater, and a plurality of column units each having a column wound around a cylindrical bobbin having a different diameter are coaxially fitted on the outer circumference of the sample valve. A gas chromatograph characterized by being equipped.