JPS6119287B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an absorption tube in an apparatus for collecting gas using an absorbent.

For example, in liquid scintillation measurement of carbon dioxide gas, carbon dioxide gas is absorbed and collected by an absorbent soluble in a liquid scintillator, and then measured.

Conventionally, so-called air washing bottles have sometimes been used for collection, but only large-capacity bottles are commercially available and require a large amount of absorbent.

However, for example, a container for measuring liquid scintillation has a small capacity of only about 20 ml, so even if a large amount of absorbent absorbs it, only a portion of it will be used for measurement, which is wasteful. Moreover, since the carbon dioxide gas is absorbed by a large amount of absorbent, the concentration of carbon dioxide gas absorbed by the absorbent is low, which is unfavorable for measurement.

Therefore, various attempts have been made to reduce the capacity of the air washing bottle, to modify its shape or structure, to install a container that is convenient for collecting the absorbent that has absorbed carbon dioxide gas into the measuring container, and to do so.

However, they have advantages and disadvantages, and many are inconvenient for injection of absorbent or recovery after absorption. Furthermore, as will be discussed later, reducing the capacity does not necessarily lead to the miniaturization of the device.

Examples of such a collection device include those shown in Figures 1 to 5.
What is shown in the figure is publicly known. In the figure, 1 is a port for injecting the mixed gas, 2 is an absorption tube for absorbing the target gas into the absorbent, 3 is a port for injecting the absorbent, 4 is a port for discharging the gas, and 5 is a foaming tube. 6 is a mantle tube, 7 is a port for injecting the scintillator, 8 is a port for collecting liquid such as absorbent,
9 is Patsuking. These mouths that serve the same purpose are also numbered in the figure.

The gases collected in this type of device, such as carbon dioxide gas, are conveyed by the air or carrier gas injected through the port 1, and their proportion in such a gas mixture is low. Therefore, if you try to collect as much carbon dioxide as possible in a short time, the absorption tube 2
The flow rate per unit time of the mixed gas to be atomized must be increased.

An absorbent, such as monoethal amine, is injected into the absorption tube 2 from the port 3 in advance, and the carbon dioxide gas in the mixed gas blown into the absorbent is absorbed, and the remaining gas is released from the port 4. It is discharged.

In the above case, when the flow rate of the mixed gas is small, appropriate bubbling is performed via the bubbling filter 5, for example, to promote the absorption action.

However, when the flow rate per unit time increases, severe bubbling causes problems such as the absorbent being blown upward and scattered to the outside. Therefore,
There are also examples in which the absorption tube 2 is provided with a plurality of constrictions, as in the examples shown in FIGS. 1 to 3, and projections are further provided inside the absorption tube, as in the example in FIG. The above example is
Even if the capacity of the absorption tube is reduced (in order to balance the collection rate, the diameter of the tube is made smaller, the blow-up by fumes is large, so the length of the tube needs to be increased, and the absorption tube etc. has a complicated shape structure. The device cannot necessarily be miniaturized (because it requires a jacket tube 6 to protect it).

Next, a scintillator is injected from the port 7 into the absorbent in the absorption tube 2 after the mixed gas has been injected, and the mixed liquid is transferred from the port 8 to a scintillation measurement container and collected. In the example shown in Fig. 5, the absorption tube shown in Fig. C is also used as the measurement container, and this and b
There is an example of using a packing 9 with an air inlet pipe and an exhaust pipe as shown in the figure in combination as shown in figure a, but if the internal volume of the absorption pipe c is small, or if the internal volume of the absorption pipe c is too large for the absorbent. If the gas flow rate is not extremely large compared to the amount, it is practically difficult to increase the gas flow rate per unit time due to bubbling and other reasons.

The object of the present invention is to realize an absorption tube which avoids the above-mentioned difficulties and disadvantages, and this will be explained below.

FIG. 6a shows an example of the absorption tube 2 of the present invention;
Fig. 6b shows the packing 9, Fig. 6c shows the scintillation measurement container 10 (hereinafter referred to as a vial), and Fig. 7 shows a state in which Figs. 6a, b, and c are combined.

In Fig. 6a, 11 is the outer tube, 12 is the foot tube,
13 is an inner tube, and 14 is one of the openings of the inner tube.
The outer tube 11 has a cylindrical shape starting at the mouth 4, the tube wall has a constriction as shown in the figure, and the cylinder becomes a thin foot tube 12 at the other end and communicates with the outside world at the mouth 8. In addition, inner tube 1
3 is a thin tube starting from the mouth 1, which in the figure has a bulge at an alternate position with the constriction of the outer tube, and the outlet of the inner tube is joined to the outer tube on the side of the foot tube of the outer tube;
and opens to the outside of the outer tube.

What is shown in FIG. 6a above is only one embodiment;
The absorption tube of the present invention generally has the following structure.

That is, it has a double structure formed by an inner tube and an outer tube, each of which has at least one protrusion such as a constriction or bulge, and the inner tube and outer tube are joined near both ends, At this junction, both tubes open to the other outside, and the openings of the inner tube and outer tube at one end are each configured to be connectable to an external piping system such as a gas source or a liquid supply source. At the other end, the opening of the outer tube opens near the tip of a foot tube that is elongated and elongated by a length corresponding to the vial used in combination. Thus, such a foot tube may be formed integrally with the outer tube, or may be formed by providing a connecting end on the outer tube and connecting it thereto with ease.

Therefore, the space surrounded by the outer tube of the inner tube and the inner tube of the outer tube provides the internal volume of the absorption tube, and the outer tube plays the role of protecting the thin inner tube even without providing a mantle tube. .

When the absorption tubes 2 described above are assembled as shown in FIG. 7, they are positioned so that the opening 8 of the foot tube is in close contact with the bottom surface of the vial. Alternatively, it goes without saying that the above combination can be carried out by bringing the tip of the foot tube into contact with the bottom surface by an appropriate method such as making the opening 8 of the foot tube oblique.

To collect a gas such as carbon dioxide using the above combination, first, 2 to 3 ml of a suitable amount of a carbon dioxide absorbent such as monoethanolamine is injected into a vial. Before the above-mentioned combination, it is poured directly through the port 3, and after the combination, it is allowed to flow down from the port 4 and injected through the port 8.

Next, by introducing the mixed gas under pressure from port 1, or by connecting port 1 to a mixed gas supply source and reducing the pressure on the port 4 side, the mixed gas will enter the vial from port 1 using the inner pipe as the gas introduction pipe. The internal absorbent (monoethalamine) is pushed up into the absorption tube through the foot tube opening 8 by the gas pressure, and bubbling subsequently begins.

The absorbent blown up by bubbling collides with the constrictions and bulges on the wall of the absorption tube, and only exhaust gas is discharged from the port 4 without reaching the port 4. Further, such collision increases the contact rate between the gas and the absorbent, and carbon dioxide gas is efficiently captured in the absorbent.

When the introduction of the mixed gas through port 1 for such collection is stopped and port 1 is opened or set to negative pressure, the absorbent that has collected carbon dioxide flows down into the vial through port 8. At this time, if an appropriate amount of scintillator is injected from the port 7, the absorbent adhering to the inner wall of the absorption tube is washed away and flows down into the vial together with the absorbent.

In this way, the absorbent that has captured carbon dioxide gas is almost completely collected in the vial, and the scintillator is also injected, so if the vial is separated from the absorption tube 2, scintillation measurement can be performed immediately. can be applied. Note that when the absorption tube is cut off, a mixture of the absorbent and scintillator that has captured carbon dioxide remains attached to the foot tube, but the amount can be ignored compared to the capacity of the vial.

As described above, the absorption tube of the present invention has a double structure of an inner and outer tube, and the convex portions formed by constrictions and bulges on the walls of both tubes prevent scattering of the absorbent due to bubbling and increase the flow rate of the mixed gas. Even if this happens, it can be effectively prevented, so the absorbent will not scatter and flow out of the absorption tube. In particular, when the aforementioned constrictions of the outer tube and bulges of the inner tube are arranged alternately, the length of the absorption tube can be made significantly shorter and thinner than that of conventional absorbent tubes.

In addition, since the inner tube is attached to the thin gas introduction tube, the outer diameter of the absorption tube can be made smaller than in the example shown in Fig. 3, in which such an introduction tube is provided outside the absorption tube. Since the thin inner tube forming the gas introduction tube (ventilation tube) is protected by the outer tube, there is no need to provide a jacket tube.

Furthermore, the absorbent can be injected in a predetermined amount into a large number of vials before collection, which is convenient for the collection operation.

In addition, when collecting the absorbent that has captured the target gas into a vial, the entire amount of absorbent can be collected by simply pouring the scintillator through the opening 7 at the top of the absorption tube, so it is possible to collect the entire amount of absorbent from the collection device to the measurement vial as in the conventional case. There is no need to move the image to another.

Furthermore, in the conventional collection device, the gas introduction tube is in contact with or immersed in the absorbent, whereas in the absorption tube of the present invention, the gas introduction tube opens to the outside of the absorption tube, When used in combination with a vial, there is no contact with the mixture of absorbent and scintillator liquid as long as the amount is appropriate. Therefore, even when gas flows backward, the absorbent and the like will not be sucked into the gas introduction pipe. Furthermore, even if the gas system is incorrectly connected to the ports 1 and 4, there will be no accident in which the absorbent or the like flows out of the collection device.

[Brief explanation of the drawing]

1 to 5 show a conventional gas collecting device, and FIGS. 6 and 7 show an embodiment of the gas collecting absorption tube of the present invention and its method of use. 1 and 14; opening of inner tube, 4 and 8; opening of outer tube, 11; outer tube, 12; foot tube, 13; inner tube.

Claims (1)

[Claims] 1. It has an outer tube and an inner tube that leads from the outer tube wall to the outside near both ends of the outer tube, and one end of both tubes has a connection opening for connecting to a pipe system such as a gas source and a liquid supply source, respectively. The other end is provided with an opening that opens into the vial, allowing the gas introduced from the inner tube to pass through the liquid filled in the vial. In a gas collection and absorption tube that dissolves gas into a liquid, the gas introduced from the tube opening is led out from the outer tube to promote gas contact with the wall surfaces of both the inner tube and the outer tube. 1. A gas collection and absorption tube characterized in that the outer tube has a concave and convex portion for the purpose of cleaning, and the outer tube is formed as a foot tube having an open tip at the end on the vial side and having a length approximately equal to the depth of the vial.