JP2583251Y2 - Adsorption tower with bypass column - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorption column with a bypass column, and more particularly to a technique for detecting a change in performance of the adsorption column during use or the like.

[0002]

2. Description of the Related Art High-level liquid waste generated in facilities related to a nuclear power plant can be easily handled by vitrification. In many cases, radioactive substances such as iodine and volatile ruthenium are mixed in the off-gas generated during the vitrification process, and volatile ruthenium is filled with granular silica gel adsorbent. A technique has been studied in which the silica gel is adsorbed onto a silica gel adsorbent by being sent to a so-called adsorption tower for reaction.

In an adsorption tower, the adsorption efficiency tends to gradually decrease due to the adsorption reaction over a long period of time, and the desired performance cannot be maintained.

Conventionally, the following two measures have been considered to cope with a decrease in the adsorption efficiency. How to change the adsorbent during operating hours or periodically. A method in which a sample gas is sampled from the vicinity of an inlet and an outlet of an adsorption tower, and a change in ruthenium concentration is measured to detect whether or not the adsorption efficiency has decreased.

[0005]

However, the above two methods have the following disadvantages. In other words, in the former method, the degree of deterioration of the adsorbent depends on the operation conditions, and the operation time is hardly linked to the evaluation of the adsorption efficiency. In the latter method, it is impossible to detect the degree of deterioration when volatile ruthenium is not actually generated.

The present invention has been made in view of the above circumstances, and has as its object to confirm the performance at any time regardless of the operation time or the concentration of the nuclide to be adsorbed.

[0007]

In the present invention, an adsorption tower with a bypass column is provided with an adsorption tower filled with an adsorbent of a nuclide to be adsorbed contained in an inserted off-gas, and one of the off-gases connected in parallel to the adsorption tower. The bypass column is inserted into the bypass column, and an adsorbent cartridge is loaded in the bypass column in series and filled with the same type of adsorbent as the adsorbent in the adsorption tower.

[0008]

During the operation of the adsorption tower, off-gas is inserted into the interior of the adsorption tower, and a part of the off-gas is sent to the bypass column to adsorb the nuclide to be adsorbed by the adsorbent cartridge. At a desired time, the adsorbent cartridge in the bypass column is taken out, and by checking to which position in the series connection the deterioration has progressed, the progress of the deterioration of the adsorption tower main body is indirectly analogized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an adsorption tower with a bypass column according to the present invention will be described below with reference to FIG. In the figure, X is a radioactive exhaust gas source, Y is an off-gas discharge system, 1 is an adsorption tower (adsorption tower main body), 2 is a bypass column, 2a is a cap, 2b is a fastener, 3 is an adsorbent cartridge, and 4 is a branch pipe. Reference numeral 5 denotes a merging pipe, reference numeral 6 denotes a flow detection control means, reference numeral 7 denotes a flow control valve, and reference numeral 8 denotes an on-off valve.

The adsorption tower 1 is disposed between the radioactive exhaust gas generation source X and the off-gas discharge system Y, and is filled with an adsorbent such as particulate silica gel.

The bypass column 2 has, for example, a cylindrical shape, in which a plurality of adsorbent cartridges 3 are loaded in series, and a cap 2a is attached with fasteners 2b such as bolts and nuts to form an airtight structure. Become.

The adsorbent cartridge 3 is loaded with a plurality of adsorbents filled with the same type of adsorbent as the adsorbent of the adsorption tower 1, as shown in FIG. In the loaded state, the flow paths are set in series, and the space between the flow path and the inner wall of the bypass column 2 is set to be airtight. The bed height of the adsorbent with the adsorbent cartridges 3 connected in series is set according to, for example, the bed height of the adsorption tower 1.

In the adsorption tower with the bypass column thus constructed, the adsorption tower 1 and the bypass column 2 are operated in parallel so that the nuclides to be adsorbed by the adsorption tower 1 and the bypass column 2 can be removed. Adsorption is performed. That is,
While opening the flow control valve 7 and the on-off valve 8,
The amount of off-gas flowing through the branch pipe 4 is detected by the flow rate detection control means 6, and the amount of gas passing through the bypass column 2 is controlled, for example, in proportion to the cross-sectional area between the adsorption tower 1 and each of the adsorbent cartridges 3.

While the off-gas sent to the bypass column 2 passes through each adsorbent cartridge 3 sequentially, the adsorbed nuclide is captured (adsorbed) by the adsorbent, and the off-gas from which the adsorbed nuclide has been removed is combined with the merging pipe 5. Is taken off by the off-gas discharge system Y and processed.

In the adsorption tower 1 and the adsorbent cartridge 3,
As the amount of adsorbed nuclides increases, a phenomenon occurs in which the adsorbent in the upstream portion deteriorates first, and the deterioration of the adsorbent in the downstream portion delays.

Therefore, the cap 2a of the bypass column 2 is removed, a plurality of adsorbent cartridges 3 are pulled out, and the adsorbent cartridge 3 is adsorbed by a method such as measuring the dose or individual performance of each adsorbent cartridge 3. By examining, it is possible to detect how much deterioration of the adsorbent has progressed.

[0017]

As described above, in the adsorption tower with the bypass column according to the present invention, the adsorption tower filled with the adsorbent for adsorbing the nuclide to be adsorbed, the bypass column connected in parallel to the adsorption tower, Since the configuration including the adsorbent cartridge in which a plurality of the adsorbents are loaded in the bypass column in a serially connected state is adopted, the following effects are obtained. (1) The adsorbent cartridge of the bypass column is pulled out and the degree of deterioration is checked to detect the deterioration of the adsorption tower. Therefore, the deterioration degree can be determined with high accuracy without being affected by the operating conditions of the adsorption tower. Can be detected. (2) Since the adsorbent of the bypass column deteriorates according to the amount of off-gas inserted and the nuclide contained, the adsorption performance can be confirmed regardless of the operation time or the concentration of the nuclide to be adsorbed. (3) By pulling out the adsorbent cartridge from the bypass column, a change in the performance of the adsorption tower can be detected at any time during use or the like. (4) The degree of deterioration can be easily and accurately managed to improve the reliability of the equipment. (5) Even in the off-gas passage where sampling gas cannot be collected and confirmed, it is possible to confirm the maintenance of the adsorption performance and to ensure the soundness of the off-gas passage.

[Brief description of the drawings]

FIG. 1 is a front view showing a block diagram of an embodiment of an adsorption tower with a bypass column according to the present invention.

[Explanation of symbols]

 X Radioactive exhaust gas generation source Y Offgas discharge system 1 Adsorption tower (adsorption tower main body) 2 Bypass column 2a Cap 2b Fastener 3 Adsorbent cartridge 4 Branch pipe 5 Merging pipe 6 Flow rate detection control means 7 Flow rate regulating valve 8 Open / close valve

Claims (1)

(57) [Scope of request for utility model registration] 1. An adsorption tower filled with an adsorbent of a nuclide to be adsorbed contained in an inserted off-gas, a bypass column connected in parallel to the adsorption tower and through which a part of the off-gas is inserted,
An adsorbent cartridge with a bypass column, comprising: a plurality of adsorbent cartridges loaded in series in the bypass column and filled with the same adsorbent as the adsorbent in the adsorber.