JPH0334968B2 - - Google Patents
Info
- Publication number
- JPH0334968B2 JPH0334968B2 JP59187932A JP18793284A JPH0334968B2 JP H0334968 B2 JPH0334968 B2 JP H0334968B2 JP 59187932 A JP59187932 A JP 59187932A JP 18793284 A JP18793284 A JP 18793284A JP H0334968 B2 JPH0334968 B2 JP H0334968B2
- Authority
- JP
- Japan
- Prior art keywords
- adsorbent
- iodine
- adsorption
- impregnated
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000003463 adsorbent Substances 0.000 claims description 72
- 238000001179 sorption measurement Methods 0.000 claims description 55
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims description 53
- 229910052740 iodine Inorganic materials 0.000 claims description 53
- 239000011630 iodine Substances 0.000 claims description 53
- 239000002245 particle Substances 0.000 claims description 26
- 229910052709 silver Inorganic materials 0.000 claims description 17
- 239000004332 silver Substances 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 150000002736 metal compounds Chemical class 0.000 claims description 8
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 claims description 7
- 229920006395 saturated elastomer Polymers 0.000 claims description 7
- 229940100890 silver compound Drugs 0.000 claims description 4
- 150000003379 silver compounds Chemical class 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 15
- 238000006243 chemical reaction Methods 0.000 description 13
- 238000012545 processing Methods 0.000 description 8
- 238000009792 diffusion process Methods 0.000 description 7
- 238000012958 reprocessing Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 239000011148 porous material Substances 0.000 description 5
- 230000002285 radioactive effect Effects 0.000 description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 229910021612 Silver iodide Inorganic materials 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- JKFYKCYQEWQPTM-UHFFFAOYSA-N 2-azaniumyl-2-(4-fluorophenyl)acetate Chemical compound OC(=O)C(N)C1=CC=C(F)C=C1 JKFYKCYQEWQPTM-UHFFFAOYSA-N 0.000 description 3
- 229910021536 Zeolite Inorganic materials 0.000 description 3
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 3
- 229940045105 silver iodide Drugs 0.000 description 3
- 239000010457 zeolite Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 2
- 239000003758 nuclear fuel Substances 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- ALKZAGKDWUSJED-UHFFFAOYSA-N dinuclear copper ion Chemical compound [Cu].[Cu] ALKZAGKDWUSJED-UHFFFAOYSA-N 0.000 description 1
- INQOMBQAUSQDDS-UHFFFAOYSA-N iodomethane Chemical compound IC INQOMBQAUSQDDS-UHFFFAOYSA-N 0.000 description 1
- 239000011133 lead Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052680 mordenite Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- -1 silver mordenite Chemical compound 0.000 description 1
- 210000001685 thyroid gland Anatomy 0.000 description 1
Landscapes
- Treating Waste Gases (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、原子力施設から放出される排ガス中
の放射性ヨウ素を除去するようにしたフイルタを
有する金属添着吸着材によるヨウ素除去方法に係
り、特に再処理プラントなど高濃度のヨウ素除去
に好適なヨウ素除去フイルタの運転条件に関する
ものである。Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to an iodine removal method using a metal-impregnated adsorbent having a filter designed to remove radioactive iodine from exhaust gas emitted from nuclear facilities, and particularly relates to a method for removing radioactive iodine from exhaust gas emitted from nuclear facilities. The present invention relates to operating conditions for an iodine removal filter suitable for removing high concentrations of iodine in processing plants and the like.
原子力施設では、周辺住民の放射能被曝を防止
するため、周辺環境へ放出される放射能量を低減
するための種々の対策が講じられている。このう
ち、放射性ヨウ素に対しては、これが人体の甲状
腺に選択的に吸収され放射能被曝を増大させるた
め、特に厳格な放出放射能量の低減対策が施され
ている。排ガスの低減対策としては、１〜２mmφ
程度の吸着材を充填したフイルタの設置が一般的
に行なわれている。原子力施設の代表的なものと
して原子力発電所と核燃料再処理プラントがあげ
られる。前者では古くから吸着材を充填したフイ
ルタが用いられており、線速度、粒径、層厚さな
ど諸条件について、Regulatory Guide1.140や
RDT Standerdなどに明確に規定されている。
すなわち、線速度20cm／ｓ、層厚５cm、吸着材粒
径４〜16mesh（4.76〜1.19mmφ、平均粒径４〜1.7
mmφ）などの条件が規定されている。一方、後者
の核燃料再処理プラントでは、前者の条件をその
まま適用しているのが現状である。しかし、それ
ら両者には大きな相違点がある。すなわち、原子
力発電所では、対象とする放射性ヨウ素が短半減
期 131I（半減期８日）で、ヨウ素の濃度が0.1ppb
と極めて低い。一方、再処理プラントでは対象と
する放射性ヨウ素が長半減期の 129I（半減期1.7×
107年）で、ヨウ素濃度が前者の50000倍の50ppm
と高い。これらの相違から、再処理プラントの排
ガス処理用の吸着材に対して次の３つの事が要求
される。すなわち、 129Iを化学的に安定な化合
物として半永久的に貯蔵できること、プラントか
らの放射能放出量を低減するため 129Iの高い除
去効率が得られること、吸着材のヨウ素吸着容量
が大きく廃棄物としての使用済吸着材量が少ない
ことの３点である。また 129Iの安定な化合物と
してはヨウ化銀があり、銀を添着した吸着材が広
範囲に用いられようとしている。この場合、吸着
材の使用量が大きくなることは、高価な銀を多量
に使用することとなり、運転コストを増大させる
こととなる。
At nuclear facilities, various measures are taken to reduce the amount of radioactivity released into the surrounding environment in order to prevent the surrounding residents from being exposed to radiation. Of these, radioactive iodine is selectively absorbed by the human thyroid and increases radiation exposure, so particularly strict measures are taken to reduce the amount of radioactivity released. As a measure to reduce exhaust gas, 1 to 2 mmφ
It is common practice to install a filter filled with a certain amount of adsorbent. Representative examples of nuclear facilities include nuclear power plants and nuclear fuel reprocessing plants. For the former, filters filled with adsorbent have been used for a long time, and various conditions such as linear velocity, particle size, layer thickness, etc.
It is clearly stipulated in RDT Standard etc.
That is, linear velocity 20 cm/s, layer thickness 5 cm, adsorbent particle size 4-16 mesh (4.76-1.19 mmφ, average particle size 4-1.7
mmφ) and other conditions are specified. On the other hand, the former condition is currently applied to the latter nuclear fuel reprocessing plant. However, there are major differences between the two. In other words, at nuclear power plants, the target radioactive iodine has a short half-life of 131 I (half-life of 8 days), and the concentration of iodine is 0.1 ppb.
extremely low. On the other hand, in reprocessing plants, the target radioactive iodine is 129 I (half-life 1.7×
107 years), and the iodine concentration is 50ppm, which is 50,000 times that of the former.
That's high. Because of these differences, the following three requirements are required for adsorbents for treating exhaust gas in reprocessing plants. In other words, 129 I can be stored semi-permanently as a chemically stable compound, high removal efficiency of 129 I can be obtained to reduce the amount of radioactivity released from plants, and the adsorbent has a large iodine adsorption capacity and can be easily stored as a waste material. The three points are that the amount of used adsorbent is small. Silver iodide is a stable compound of 129 I, and adsorbents impregnated with silver are about to be widely used. In this case, increasing the amount of adsorbent used means using a large amount of expensive silver, which increases operating costs.
以上の点から、再処理プラントのヨウ素除去フ
イルタに対して除去効率が高く、ヨウ素の吸着量
が大きくなるようにすることが必要である。 From the above points, it is necessary for the iodine removal filter of the reprocessing plant to have high removal efficiency and a large amount of iodine adsorption.
本発明は、再処理プラント排ガス系に設置され
るヨウ素フイルタの好適な運転条件を提供するこ
とにより、上記従来方法における欠点をなくする
ことにある。
The present invention aims to eliminate the drawbacks of the above conventional methods by providing suitable operating conditions for an iodine filter installed in the exhaust gas system of a reprocessing plant.
本発明の特徴は、ヨウ素と反応する金属または
金属化合物を添着した吸着材の充填フイルタにお
いて、充填フイルタ内にヨウ素の飽和吸着帯の現
われるような高濃度のヨウ素を処理する場合、吸
着材平均粒径dP（mm）と線速度ｕ（cm／ｓ）が次の
３つの条件を同時に満足する条件で当該フイルタ
を運転することにある。
A feature of the present invention is that in a filter filled with an adsorbent impregnated with a metal or metal compound that reacts with iodine, when processing iodine at a high concentration such that a saturated adsorption band of iodine appears in the packed filter, the average particle size of the adsorbent is The purpose of this filter is to operate the filter under conditions in which the diameter d P (mm) and the linear velocity u (cm/s) simultaneously satisfy the following three conditions.
ｕ≦24／dP 2 ……(1)
ｕ≦105×dP 2 ……(2)
ｕ≧0.2 ……(3)
〔発明の実施例〕
前述した(1)〜(3)式の条件を満足する範囲を第１
図に示す。図中の直線Ａ，Ｂ，Ｃは、それぞれ上
記の(1)、(2)、(3)式の境界条件を表わす。 u≦24/d P 2 ...(1) u≦10 5 ×d P 2 ...(2) u≧0.2 ...(3) [Embodiments of the invention] The above-mentioned equations (1) to (3) The range that satisfies the conditions is the first
As shown in the figure. Straight lines A, B, and C in the figure represent the boundary conditions of the above equations (1), (2), and (3), respectively.
本発明の従属する特徴は、上記特徴に加え、ヨ
ウ素と反応する金属または金属化合物を添着した
吸着材が、銀または銀化合物を添着した吸着材で
あることにある。 A dependent feature of the present invention, in addition to the above features, is that the adsorbent impregnated with a metal or metal compound that reacts with iodine is an adsorbent impregnated with silver or a silver compound.
本発明は以下の実験結果に基づきなされたもの
である。第２図に吸着材の吸着塔内のヨウ素吸着
分布を示す。再処理プラントではヨウ素の濃度が
高いため、運転をつづけると、飽和吸着帯と吸着
帯とが現われる。飽和吸着帯は吸着材のヨウ素を
吸着する最大の能力に達した部分で、もはやヨウ
素の吸着ができなくなつた部分である。一方吸着
帯は、吸着材にヨウ素の吸着能力が残つている部
分で、ここで、ヨウ素の吸着が進行している。発
明者らは、銀添着吸着材など種々のヨウ素と反応
する金属または金属化合物について実験を行な
い、第２図に示す吸着分布が得られることを確認
すると同時に、吸着帯の形が維持されながら進行
する定形吸着帯型の吸着が起こることを見い出し
た。ここで吸着帯が現われるのは、公知の事実で
あるが、吸着帯が定形で進行するかどうかについ
ては、反応系によつて異なるため、発明者らがヨ
ウ素の吸着反応について実験的に確認したもので
ある。 The present invention was made based on the following experimental results. Figure 2 shows the iodine adsorption distribution of the adsorbent in the adsorption tower. Due to the high concentration of iodine in reprocessing plants, if the plant continues to operate, saturated adsorption zones and adsorption zones will appear. The saturated adsorption zone is the area where the adsorbent has reached its maximum ability to adsorb iodine and is no longer able to adsorb iodine. On the other hand, the adsorption zone is a portion where the adsorbent still has the ability to adsorb iodine, and iodine adsorption is progressing here. The inventors conducted experiments with various metals or metal compounds that react with iodine, such as silver-impregnated adsorbents, and confirmed that the adsorption distribution shown in Figure 2 could be obtained, and at the same time, the adsorption progressed while maintaining the shape of the adsorption zone. It was found that a regular adsorption band type adsorption occurs. It is a well-known fact that an adsorption band appears here, but whether or not the adsorption band progresses in a regular manner depends on the reaction system, so the inventors experimentally confirmed the iodine adsorption reaction. It is something.
上記実験事実に基づき、吸着塔中に飽和吸着帯
と吸着帯が得られるようなヨウ素の吸着実験を行
ない、吸着帯が短かくなる条件を選定した。吸着
帯が短かくなることは、吸着材の有効利用率が高
くなり、吸着材の使用量が少なくなると同時に、
吸着材の交換頻度を少なくできることにつなが
る。 Based on the above experimental facts, an iodine adsorption experiment was conducted to obtain a saturated adsorption zone and an adsorption zone in the adsorption column, and conditions were selected to shorten the adsorption zone. The shorter adsorption zone means that the effective utilization rate of the adsorbent is higher, and at the same time, the amount of adsorbent used is reduced.
This leads to the ability to reduce the frequency of replacing the adsorbent.
まず、線速度条件をパラメータとし、吸着材と
して吸着材平均粒径1.5mmの銀ゼオライトを用い
て実験を行なつた。第３図にその結果を示す。こ
の図から、線速度15cm／ｓ以上では、吸着量の小
さい部分で尾を引く現象であるテイリンクがみら
れる。これは、吸着帯の長さを著しく長くする主
因になる。したがつて、10cm／ｓ以下の線速度条
件で使用することが好適であることがわかつた。 First, an experiment was conducted using silver zeolite with an average particle size of 1.5 mm as the adsorbent, using the linear velocity condition as a parameter. Figure 3 shows the results. This figure shows that at linear velocities of 15 cm/s or higher, tail link is observed where the amount of adsorption is small. This is the main cause of significantly increasing the length of the adsorption zone. Therefore, it was found that it is suitable to use the linear velocity condition of 10 cm/s or less.
次に、吸着材平均粒径をパラメータとして、実
験を行なつた結果を第４図に示す。この図から、
線速度条件だけでなく、吸着材の平均粒径によつ
ても、テイリングの発生の有無が変化することが
わかつた。すなわち、吸着材平均粒径が1.5mmで
はテイリングが発生するが、0.7mmではテイリン
グが発生していない。 Next, FIG. 4 shows the results of an experiment using the average particle diameter of the adsorbent as a parameter. From this figure,
It was found that the presence or absence of tailing changes not only depending on the linear velocity conditions but also on the average particle size of the adsorbent. That is, tailing occurs when the average particle diameter of the adsorbent is 1.5 mm, but no tailing occurs when the average particle diameter of the adsorbent is 0.7 mm.
以上の２つの実験事実に基づき、テイリングの
発生しない吸着材平均粒径と線速度条件を求め
た。その条件を示したのが第１図で、テイリング
の生じない条件の限界は、図中の直線Ａである。
また図中の他の直線は、それぞれ、次の条件から
求められたものである。まず、直線Ｂは、吸着材
が吸着塔内で流動化する限界で、粒径が小さくな
るほど、また線速度が大きくなるほど流動化しや
すいことがわかる。また、直線Ｃは、ヨウ素分子
の拡散速度で、これ以上線速度を小さくしても、
熱運動によつてヨウ素分子が吸着塔の下流側に進
行してしまうため、吸着帯は短かくならない。し
たがつて、これらの直線Ａ，Ｂ，Ｃによつて囲ま
れる条件が、吸着塔で、高濃度のヨウ素を除去す
るために好適な条件となる。 Based on the above two experimental facts, the average particle diameter of the adsorbent and the linear velocity conditions under which tailing does not occur were determined. The conditions are shown in FIG. 1, and the limit of the conditions under which no tailing occurs is the straight line A in the figure.
Further, the other straight lines in the figure are obtained from the following conditions. First, the straight line B is the limit at which the adsorbent fluidizes within the adsorption tower, and it can be seen that the smaller the particle size and the higher the linear velocity, the easier it is to fluidize. In addition, the straight line C is the diffusion rate of iodine molecules, and even if the linear velocity is decreased further,
Because the iodine molecules proceed downstream of the adsorption tower due to thermal movement, the adsorption zone does not become shorter. Therefore, the conditions surrounded by these straight lines A, B, and C are suitable conditions for removing high-concentration iodine using an adsorption tower.
吸着塔または吸着材充填フイルタにおいて、ヨ
ウ素の飽和吸着帯が存在しない場合、吸着帯の長
さは一定とならず、時間の経過とともに変化す
る。したがつて、吸着帯の長さを線速度と吸着材
粒径との関係で明確に得ることはできない。 In an adsorption tower or an adsorbent-filled filter, if there is no saturated adsorption zone for iodine, the length of the adsorption zone is not constant and changes over time. Therefore, the length of the adsorption zone cannot be clearly determined from the relationship between linear velocity and adsorbent particle size.
また、反応系が異なる場合、すなわち、ヨウ素
とヨウ素と反応する金属を添着した吸着材との吸
着反応以外の実験結果は、本発明とは異なる。こ
のことを、吸着材による吸着反応機構の点から詳
細に述べる。第５図は一例として銀添着吸着材を
とり上げ吸着材の断面を模式的に示した図であ
る。ヨウ素（I2：分子状ヨウ素、CH3I：ヨウ化
メチル）は境膜拡散、細孔内拡散、化学反応の３
つの段階を経てヨウ化銀（AgI）などとして、化
学的に安定な化合物として吸着材中に取り込まれ
る。ここで境膜拡散とは、吸着材粒子の表面に形
成される気体の静上層である境膜中のヨウ素の拡
散である。境膜の外側は、気体（処理ガス）の流
れが生じている部分である。細孔内拡散とは、吸
着材内に存在する数10〜数100Åの直径をもつ無
数の小さな孔があり、この孔内を添着された銀に
達するまでヨウ素が進んでゆく拡散である。化学
反応とは、ヨウ素が銀との化学反応によつてヨウ
化銀となることを意味している。ここで通常の吸
着反応では、境膜、細孔内拡散などが律速となつ
ている。一方、本発明の場合、ヨウ素を化学的に
吸着すること、ヨウ素の吸着量が多く、残留する
未反応の銀が少ないことから、化学反応が吸着の
律速となつている。したがつて、ヨウ素と銀、ヨ
ウ素とヨウ素と反応する金属との反応以外の反応
系は本発明とは全く異なるものである。 Further, when the reaction system is different, that is, the experimental results other than the adsorption reaction between iodine and an adsorbent impregnated with a metal that reacts with iodine are different from the present invention. This will be described in detail from the viewpoint of the adsorption reaction mechanism by the adsorbent. FIG. 5 is a diagram schematically showing a cross section of a silver-impregnated adsorbent as an example. Iodine (I 2 : molecular iodine, CH 3 I: methyl iodide) undergoes three processes: film diffusion, pore diffusion, and chemical reaction.
After going through two stages, it is incorporated into the adsorbent as a chemically stable compound such as silver iodide (AgI). Here, the film diffusion refers to the diffusion of iodine in the film, which is the upper layer of gas formed on the surface of the adsorbent particles. The outside of the boundary film is the area where gas (processing gas) flows. Pore diffusion is a process in which there are countless small pores with diameters of several tens to hundreds of angstroms existing within the adsorbent, and iodine progresses through these pores until it reaches the impregnated silver. Chemical reaction means that iodine becomes silver iodide through a chemical reaction with silver. In a normal adsorption reaction, the rate-determining factors include the boundary film and pore diffusion. On the other hand, in the case of the present invention, iodine is chemically adsorbed, the amount of iodine adsorbed is large, and residual unreacted silver is small, so that the chemical reaction is rate-limiting for adsorption. Therefore, the reaction system other than the reaction between iodine and silver and between iodine and a metal that reacts with iodine is completely different from the present invention.
したがつて、本発明は、ヨウ素を化学吸着する
場合で、かつ吸着塔内にヨウ素の飽和吸着帯が現
われる場合にのみ該当するものである。 Therefore, the present invention is applicable only when iodine is chemically adsorbed and when a saturated adsorption zone of iodine appears in the adsorption column.
なお、ここに記載した例は銀ゼオライトについ
てのみであるが、これは一例でしかなく、本発明
ではこれに限定されることはない。銀ゼオライト
以外の銀モルデナイト、銀アルミナ、銀シリカゲ
ル等の他の銀添着吸着材についても同様の結果が
得られる。またヨウ素と化学的に吸着する金属ま
たは金属化合物としては、鉛、銅、パラジウムお
よびその化合物などがあるが、前者２つ（鉛、
銅）についてはヨウ素との化学反応速度が小さ
く、本発明の第１図のＡの直線よりも、小さくな
るが、本発明の概念に含まれるものである。後者
（パラジウム）については、銀または銀化合物と
同等の反応性を有するが、銀よりも高価である欠
点がある。 Note that although the example described here is only about silver zeolite, this is only an example, and the present invention is not limited thereto. Similar results can be obtained with other silver-impregnated adsorbents other than silver zeolite, such as silver mordenite, silver alumina, and silver silica gel. Metals or metal compounds that chemically adsorb iodine include lead, copper, palladium, and their compounds, but the former two (lead,
Although the chemical reaction rate of copper (copper) with iodine is lower than that of the straight line A in FIG. 1 of the present invention, it is included in the concept of the present invention. The latter (palladium) has the same reactivity as silver or silver compounds, but has the disadvantage that it is more expensive than silver.
また、吸着材の平均粒径については、本発明の
第１図に図示する範囲において十分な効果を奏す
ることができる。本発明をより効果的に運用する
ためには、吸着材が外部からの衝激や振動などの
力によつて長期間使用しても粉末化などが生じ
ず、しかも高いヨウ素の吸着性能を維持できるよ
うに吸着材の平均粒径は１〜３mmの範囲にあるこ
とが望ましい。 Further, regarding the average particle size of the adsorbent, a sufficient effect can be achieved within the range shown in FIG. 1 of the present invention. In order to operate the present invention more effectively, the adsorbent must not turn into powder even after long-term use due to external forces such as shock or vibration, and maintain high iodine adsorption performance. The average particle size of the adsorbent is preferably in the range of 1 to 3 mm.
本発明の具体的実施例を図面により以下詳細に
述べる。 Specific embodiments of the present invention will be described in detail below with reference to the drawings.
本発明では、通常の吸着塔を用いても、吸着塔
に充填された吸着材粒径と、吸着塔で処理するガ
スの線速度の条件が、第１図の範囲を満足してい
れば、十分な効果を奏することができる。さらに
本発明の効果的に運用するために、吸着塔の形状
の点からいくつかの実施例を述べる。 In the present invention, even if a normal adsorption tower is used, as long as the particle size of the adsorbent packed in the adsorption tower and the linear velocity of the gas processed in the adsorption tower satisfy the ranges shown in FIG. It can produce sufficient effects. Furthermore, in order to effectively operate the present invention, some examples will be described from the viewpoint of the shape of the adsorption tower.
第６図は本発明を実施しうるのに効果的な例で
ある。本実施例は二層構造としたものである。す
なわち、吸着材粒径の大きな吸着材層を処理ガス
の入口側に、吸着材粒径の小さな吸着材層を処理
ガスの出口側に設けた二層構造である。吸着材粒
径の小さな吸着材層は、第１図の範囲を満足して
いることが必要である。また、吸着材粒径の小さ
な吸着材層の高さは、少なくとも吸着帯長さ以上
であることが必要である。第４図から、吸着材平
均粒径が0.7mmで、線速度が25cm／ｓの場合、吸
着材層の高さは2.5cm以上にすれば良いことにな
る。 FIG. 6 is an effective example of how the present invention can be implemented. This example has a two-layer structure. That is, it has a two-layer structure in which an adsorbent layer with a large adsorbent particle size is provided on the inlet side of the processing gas, and an adsorbent layer with a small adsorbent particle size is provided on the outlet side of the processing gas. The adsorbent layer with a small adsorbent particle size needs to satisfy the range shown in FIG. Further, the height of the adsorbent layer having a small adsorbent particle size needs to be at least equal to or greater than the length of the adsorption zone. From FIG. 4, when the average particle diameter of the adsorbent is 0.7 mm and the linear velocity is 25 cm/s, the height of the adsorbent layer should be 2.5 cm or more.
本発明例によれば、圧力損失の生じやすい吸着
材粒径の小さな層が短かくなるため、圧力損失が
少なく、処理ガスを流すのに用いるブロワーの容
量を低減できるなどの効果をもたらす。 According to the example of the present invention, the layer of small adsorbent particle size that is likely to cause pressure loss is shortened, resulting in less pressure loss and the ability to reduce the capacity of the blower used to flow the process gas.
第７図に本発明を実施しうるのに効果的な他の
実施例を示す。この実施例は、円柱状の吸着材充
填層である。処理ガスは、円柱状の吸着材充填層
の中央部に設けられた同心円状の孔から流入し、
円柱の外周方向へ流れる。この方式では、処理ガ
スの線速度が、中心部の入口側では大きいが、外
周側では小さくなる。この方式の場合、外周から
円柱中心に向かつての吸着帯長さ位置での、線速
度と吸着材平均粒径とが第１図の条件を満足する
ようにする必要がある。すなわち、第３図から、
吸着材平均粒径が1.5mmの場合、線速度を10cm／
ｓ以下としなければならない点は、吸着材充填層
外周側から３cm以上中心に向かつた点である。 FIG. 7 shows another embodiment that is effective for carrying out the present invention. This example is a cylindrical adsorbent packed bed. The processing gas flows in through a concentric hole provided in the center of the cylindrical adsorbent packed bed.
Flows toward the outer circumference of the cylinder. In this method, the linear velocity of the processing gas is large on the inlet side of the center, but becomes small on the outer peripheral side. In the case of this method, it is necessary to ensure that the linear velocity and the average particle diameter of the adsorbent satisfy the conditions shown in FIG. 1 at the length of the adsorption zone from the outer periphery toward the center of the cylinder. That is, from Figure 3,
When the average particle size of the adsorbent is 1.5 mm, the linear velocity is set to 10 cm/
The point that must be less than s is a point that is 3 cm or more toward the center from the outer periphery of the adsorbent packed bed.
本実施例によれば、円柱状の特徴を生かし、処
理ガスの出口側で、線速度を低下させることがで
きる。 According to this embodiment, the linear velocity can be reduced on the exit side of the processing gas by taking advantage of the cylindrical feature.
また、吸着層をバツケージ化し、その形状を、
放射性廃棄物の廃棄物容器（通常200容積のド
ラム缶）に直接収められる構造とすることによつ
て、使用済の吸着層を直接前記廃棄物容器に収め
ることができる。 In addition, the adsorption layer is made into a bag, and its shape is
By having a structure in which the adsorption layer is directly stored in a waste container for radioactive waste (usually a 200 volume drum), the used adsorption layer can be directly stored in the waste container.
本発明によれば、高濃度のヨウ素を除去するた
めの吸着材フイルタの最適運転条件を提供できる
ので、以下の効果が得られる。
According to the present invention, it is possible to provide optimal operating conditions for an adsorbent filter for removing high-concentration iodine, so the following effects can be obtained.
(1) 吸着材の使用量を最小限度にとどめ、高い除
去性能を維持できる。(1) The amount of adsorbent used can be kept to a minimum and high removal performance can be maintained.
(2) 廃棄物としての使用済吸着材量を最小限度に
とどめることができる。(2) The amount of used adsorbent as waste can be kept to a minimum.
第１図は、本発明によるヨウ素除去方法に好適
な条件範囲を示した線図、第２図は、吸着塔内の
ヨウ素吸着分布の説明図、第３図は、線速度をパ
ラメータとしたときのヨウ素の吸着分布の実験結
果を示した線図、第４図は、吸着材粒径の異なる
吸着材のヨウ素の吸着分布の実験結果を示した線
図、第５図は、ヨウ素の吸着メカニズムを模式的
に示した図、第６図および第７図はそれぞれ本発
明を実施しうるのに好適な吸着材充填塔の例を示
した図である。
Figure 1 is a diagram showing the range of conditions suitable for the iodine removal method according to the present invention, Figure 2 is an explanatory diagram of the iodine adsorption distribution in the adsorption tower, and Figure 3 is when linear velocity is used as a parameter. Figure 4 is a diagram showing the experimental results of the iodine adsorption distribution of adsorbents with different adsorbent particle sizes. Figure 5 is the iodine adsorption mechanism. FIG. 6 and FIG. 7 are diagrams each showing an example of an adsorbent-packed column suitable for carrying out the present invention.
Claims (1)
着した吸着材の充填フイルタにおいて、吸着材平
均粒径dP（mm）と線速度ｕ（cm／ｓ）が次の３つの
条件を同時に満足することを特徴とする金属添着
吸着材によるヨウ素除去方法。 ｕ≦24／dP 2 ｕ≦105×dP 2 ｕ≧0.2 ２ 特許請求の範囲第１項において、ヨウ素と反
応する金属または金属化合物を添着した吸着材が
銀または銀化合物添着吸着材であることを特徴と
する金属添着吸着材によるヨウ素除去方法。 ３ 特許請求の範囲第１項において、金属または
金属化合物を添着した吸着材の充填フイルタを有
し、この充填フイルタ内にヨウ素の飽和吸着帯が
あることを特徴とする金属添着吸着材によるヨウ
素除去方法。 ４ 特許請求の範囲第３項において、金属または
金属化合物を添着した吸着材が、銀または銀化合
物添着吸着材であることを特徴とする金属添着吸
着材によるヨウ素除去方法。[Claims] 1. In a filter filled with an adsorbent impregnated with a metal or metal compound that reacts with iodine, the adsorbent average particle diameter d P (mm) and linear velocity u (cm/s) meet the following three conditions. A method for removing iodine using a metal-impregnated adsorbent, which is characterized in that it satisfies the following at the same time. u≦24/d P 2 u≦10 5 ×d P 2 u≧0.2 2 In claim 1, the adsorbent impregnated with a metal or metal compound that reacts with iodine is silver or an adsorbent impregnated with a silver compound. A method for removing iodine using a metal-impregnated adsorbent. 3. Iodine removal using a metal-impregnated adsorbent according to claim 1, which has a filter filled with an adsorbent impregnated with a metal or a metal compound, and has a saturated adsorption zone for iodine in the filled filter. Method. 4. The iodine removal method using a metal-impregnated adsorbent according to claim 3, wherein the adsorbent impregnated with a metal or a metal compound is an adsorbent impregnated with silver or a silver compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59187932A JPS6168127A (en) | 1984-09-10 | 1984-09-10 | Iodine removing method by metallic adhesive adsorbent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59187932A JPS6168127A (en) | 1984-09-10 | 1984-09-10 | Iodine removing method by metallic adhesive adsorbent |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6168127A JPS6168127A (en) | 1986-04-08 |
| JPH0334968B2 true JPH0334968B2 (en) | 1991-05-24 |
Family
ID=16214705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59187932A Granted JPS6168127A (en) | 1984-09-10 | 1984-09-10 | Iodine removing method by metallic adhesive adsorbent |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6168127A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3808742A1 (en) * | 1988-03-16 | 1989-09-28 | Kernforschungsz Karlsruhe | METHOD FOR REMOVING IODINE AND IODINE COMPOUNDS FROM GASES AND STEAMS WITH SILVER-BASED ZEOLITE X |
| JP3647667B2 (en) * | 1999-03-08 | 2005-05-18 | 日本原子力研究所 | Iodine removal filter and iodine removal device carrying silver |
| US20080116417A1 (en) * | 2006-11-14 | 2008-05-22 | Samuels George J | Iodine and iodide removal method |
| JP5873302B2 (en) * | 2011-11-11 | 2016-03-01 | 日立Ｇｅニュークリア・エナジー株式会社 | Waste water treatment apparatus and waste water treatment method for nuclear facilities |
| DE102012006542A1 (en) * | 2012-04-02 | 2013-10-02 | Clariant Produkte (Deutschland) Gmbh | Methyl iodide adsorber, use thereof and method of adsorbing methyl iodide |
| JP6578096B2 (en) * | 2014-11-10 | 2019-09-18 | 三菱重工業株式会社 | Radioactive substance removal apparatus and radioactive substance removal system |
| JP2018103156A (en) * | 2016-12-28 | 2018-07-05 | 大陽日酸株式会社 | Waste gas treatment column, waste gas treatment apparatus, and waste gas treatment method |
| CN109920574B (en) * | 2019-03-26 | 2020-11-24 | 西南科技大学 | Low-temperature curing method of silver-coated silica gel |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5395879A (en) * | 1977-02-02 | 1978-08-22 | Hitachi Ltd | Operating method for silver-adsorbent filter |
-
1984
- 1984-09-10 JP JP59187932A patent/JPS6168127A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5395879A (en) * | 1977-02-02 | 1978-08-22 | Hitachi Ltd | Operating method for silver-adsorbent filter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6168127A (en) | 1986-04-08 |
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