JPS6038697A - Device for concentrating and solidifying radioactive waste liquor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to an apparatus for concentrating and assimilating radioactive waste liquid.

The coagulation-sedimentation method is a conventional treatment method for radioactive waste liquid.

There are ion exchange method and evaporation concentration method. The coagulation-precipitation method is a method in which a flocculant is added to waste liquid to capture and co-precipitate radioactive substances. The ion exchange method is a method in which the main radioactive substances in the waste liquid exist as ions, and these are adsorbed and removed using an ion exchange resin. Although the above method is effective for treating large amounts of low-level radioactive waste liquid, it is not suitable for treating high-level radioactive waste liquid because the decontamination coefficient is low.

The evaporative concentration method is a method in which a large amount of water is evaporated and separated from the waste liquid, and the radioactive materials remain in the waste liquid. This method has a much higher decontamination coefficient than the above methods and is suitable for decontaminating high-level radioactive waste liquid.

At present, radioactive waste liquid generated at nuclear power plants is mainly concentrated using this evaporation concentration method, solidified by mixing with cement or asphalt, and then filled into drums and piped. As one of the treatment methods for this waste liquid, a device has already been proposed in which it is dried with a centrifugal thin film dryer and solidified with asphalt (Special Publications Publication No. 5).
2-24200 Publication) 0 This device has an asphalt assimilation device installed at the bottom of the centrifugal thin film dryer, and mixes the asphalt in the asphalt tank using the rotating shaft of the centrifugal thin film dryer. The generated powder is directly solidified with asphalt, and the waste liquid that flows out during abnormal operation of the centrifugal thin film dryer is also collected in the asphalt tank and can be solidified. This equipment collects the unevaporated liquid that flows out from the dryer. Since the water must be directly received by the asphalt tank and evaporated on the surface of the asphalt layer, the processing speed becomes slow. To prevent this, the supply amount of waste liquid is automatically controlled by detecting the moisture content of the dry powder waste liquid, but since the moisture detector is in direct contact with the dry powder substance, it is difficult to maintain its function. The present invention was developed as a result of research with the aim of solving the above-mentioned difficulties. We propose a radioactive waste liquid concentrating and solidifying device that can dry radioactive waste liquids at a nearly constant processing speed. By the way, the present inventors have already developed a method for treating radioactive waste liquid prior to the present invention, in which solidification aid and water glass are added to radioactive waste liquid and then heated, resulting in polymerized silicate gel 7 asphalt solidification or glass assimilation.

He proposes a method of solidifying cement, etc. (Takehara 0.5
B-71428. 58-73878゜58-940
21. 58-104883) The present invention relates to a processing device for carrying out the above processing method.

The gist of the present invention is to provide an apparatus for adding water glass and a solidification aid to a liquid to be treated and heating it for concentration and solidification. Evaporator body with.

(2) An injection nozzle consisting of a double tube that is driven along the heating surface and injects the liquid to be treated and water glass onto the heating surface from the inside.

(3) A scraper preceding the injection nozzle,
A scraper in which the lower end of the scraper is always ahead of its upper end in the direction of travel.

(4) A hopper, wherein the inner diameter of the heating surface and the funnel-shaped top part are formed to have approximately the same diameter so as to receive scales scraped and falling from the heating surface disposed in the evaporator body by the scraper.

(5) A rotary blade interlocked with the scraper that scrapes down scale accumulated on the hopper surface along the inner surface of the hopper.

(6) An unevaporated liquid chamber is formed at the bottom of the evaporator main body to have a diameter larger than the heating surface, and receives unevaporated liquid flowing down the heating surface through a gap with the outer diameter of the top of the funnel-shaped hopper.

(7) Means for taking out the liquid accumulated in the unevaporated liquid chamber and mixing it with the rose treatment liquid.

(8) There is a radioactive waste liquid concentration and assimilation treatment device connected to the hopper and comprising a container or solidification device for receiving scale scraped from the hopper.

The present invention will be explained and explained below with reference to the drawings.

FIG. 1 is a diagram schematically showing a vertical cross-section in the rotational axis direction of the device of the present invention, and FIG. 2 is a cross-sectional view taken along line E-E' of the device in FIG.
Furthermore, FIG. 3 is an arrow view of the 11th marsh apparatus as viewed from the F direction.

In Figs. 1 to 3, A is treated 7ζI+, , A'
indicates unevaporated liquid, B indicates water glass, C indicates dry school, and D indicates asphalt (or cement, glass material, etc.).

The structure of the device of the present invention is as follows. The heating surface 2 of the evaporator 1 is substantially vertical and has a steam jacket 3 on its outer circumferential surface. Inside the evaporator 1, a rotating shaft 6 having a double tube structure is provided. The rotating shaft 6 is
110 - The liquid to be treated A, which is connected to the nozzle 4 through the tally joint 5 and to which a solidification aid has been added in advance.
is nozzle 4. N1110 - Enters the dryer 1 via the tally joint 5 and the outer pipe of the rotating shaft A.

The rotating shaft 6a forming the inner pipe line of the one-way rotating shaft 6 is about 10
- passes through the tally joint 5 and communicates with the nozzle 8 via the tally joint 7; Water glass B is nozzle 8. The evaporator 1 is connected to the evaporator 1 via the rotary shaft 6a, that is, the inner pipe line, through the Nα20-tally joint 7.
Go inside. Naturally, since the rotating shaft 6a is partially fixed to the rotating shaft 6 forming the outer pipe line,
It is rotated together with the rotating shaft 6 by a motor 1o via a goo-goo 9 that is firmly connected to the rotating shaft 6.

Inside the evaporator 1, there are several holes around the rotating shaft.
There are 11 scraper arms 11, 11a to θ,
An injection nozzle 12 is provided at the tip of only the scraper arm 11 located at the uppermost position, and a scraper 13 that is driven prior to the injection nozzle 12 is mounted on the scraper arm 11 with a fixing metal fitting 14. has been fixed through. Only the scraper arm 11 is a double pipe, and its inner pipe line 6a' and outer pipe line are connected to the pipe lines of the rotating shafts 6a and 6, respectively. Other scraper arm 1
Only scrapers 13a%e are fixed at the tips of 1a to θ, and no pipes or injection nozzles through which the liquid to be treated or water glass should pass are provided.

The rotating shaft 6 is connected via a rotating bearing 15 to a lower rotating shaft 6'. 15' is a support arm of the rotary bearing 15. In addition, regarding the scraper arms and scrapers arranged in the vertical direction, the vertically adjacent scraper arms, i, + 1.11 a-e
and scraper 16.1! +a to e are arranged so as to be positioned at a predetermined angle to each other with respect to the rotation axis B 4B. Usually, it is arranged so that it is about 18a0 (Fig. 2). The vertical direction in which the scrapers 13.13a-e scrape the heating surface 2 is such that the scrapers 13.13a-e that are adjacent above or below overlap with the lower end of the vertical width or part of the upper anchor i in which the heating surface 2 is scraped. Each scraper 13.13
A-e are arranged □□□. Also scraper 13
．． 15a-e? -1 heating element 2, and is tilted at a predetermined angle (usually 5 to 15 degrees) with respect to the vertical line so that the lower end precedes the upper end in the direction of travel (Fig. 3).

Incidentally, the scraper arm and the scraper may be provided at a plurality of locations at the same horizontal position around the rotating shaft 6 at intervals. 16 is a steam inlet into the steam jacket 3, 17 is a steam drain outlet provided at the bottom of the steam jacket B, and 18 is an evaporative vapor outlet provided at the top of the evaporator 1. 19 is a non-evaporation chamber formed at the bottom of the heating surface 2 and having an inner diameter larger than the inner diameter of the heating surface 7;
0 is an unevaporated liquid outlet provided in the evaporation chamber 18; 21 is an unevaporated liquid outlet; 21 is an unevaporated liquid outlet that is inserted into the evaporator 1 through the 19 and opens upward; It is a funnel-shaped hopper located at Hola...
The inner diameter of the top part of 21 is formed to be approximately the same as the inner diameter of the heating surface 2, and the outer periphery thereof is formed to be the inner diameter of the heating surface 2 and the unevaporated liquid chamber 1.
9 and the side wall of Jl.
ing. , 22 are rotating blades provided along the inner surface of the hopper 21, and are firmly connected to the rotating shaft 6. The rotary blade 22 is in close contact with the slope of the inner surface of the hopper and the upper side surface of the top of the hopper 21. 23a and 23b are dampers hanging from the upper and lower ends of the cylindrical pressure regulating sensor 24 communicating with the lower part of the hopper 21. It is connected to the pressure regulating chamber 24C and the assimilation device 25, D is asphalt, 26 is an asphalt supply nozzle, and 27 is an assimilation outlet.

28 is a heat heater, and 29 is a solidifying device motor.

As the solidification aid added in advance to the liquid to be treated A, the chemicals mentioned in the above-mentioned application that have already been proposed can be used.3 In other words, if the liquid to be treated A is a solution containing uranium, inorganic acids, organic acids, carbonic acid, etc. Using an alkali, carbon dioxide gas or alkaline earth metal salt, etc., the liquid to be treated B does not contain uranium (li
In the case of radioactive waste liquid in d, in addition to boric acid, borates, phosphoric acid, primary phosphates and aluminum salts, sulfurous acid or sulfite sulfite, thiosulfate, carbon oxide, sulfur dioxide, hydrogen sulfide or sulfide are used. A substance, an aldehyde compound, a monosaccharide, an R-based oligosaccharide, a reducing organic acid or a salt thereof, etc. are used.

The operation of the device according to the invention described above will be described. The substantially vertical heating surface 2 is heated by steam blown from the steam port 16. The to-be-treated injection to which the same stimulant has been added in advance flows from the nozzle 4 to the outer pipe line of Nu 10-tally joint s, Ir 1 inversion Jql + 6,
Outside the screen arm 11 (via the +lI pipe,
The jet q/↓ reaches the nozzle 12 at the tip of the same arm. On the other hand, water glass B rJ nozzle 8 to 11120 - tally joint 71 rotations 41 + ba, N110 - tally joint f
52 throats, 16 internal pipes, 1 scraper arm
l of the tip of the arm 11 via the canal 6a'! For the first time, the sand treatment liquid A and the water glass B are mixed and ejected from the spray nozzle 12 that reaches the A nozzle 12, and are evenly coated on the surface 2.At this time, the wave treatment The water contained in the solution is immediately turned into steam and discharged from 18 at a steam ratio of 1 ml, and the solids are mixed with the solidification aid added in advance to the pine treatment solution and water glass B. Due to the interaction of heating and heating J+1, the silicic acid is immediately covered with a film of silicic acid, separated from the water, and eventually evaporated to dryness.

The scraper 13 is rotated by the motor 10 and the goury 9 through the rotary shaft 6 and 11 scraper arms while scraping the heating surface 2 and returns to its original position. C is scraped off, and it moves one after another on the surface of the screen (13) in a combined direction of upward and toward the center of the evaporator 1, and eventually falls downward from the surface of the screen (13). The liquid A to be treated that has not completely evaporated near the scraper 13 evaporates while flowing down on the heating surface 2, and is scraped off by the scrapers 13a-e in the same way as the scraper 13. It falls down, is sent further downward by the rotary vane 22, and is moved to the dampers 23a and 23bt.
By r+v primary opening 1 equal, it passes through the pressure regulation chamber 24 and falls into the solidification device 25. - The unevaporated liquid that falls along the heating surface 2 of the man's body and reaches the unevaporated armpits is because the wall 41 of the unevaporated liquid chamber 19 has a diameter that is much larger than the inner diameter of the heating surface 2. However, the unevaporated liquid does not enter the hot spring 21 and accumulates in the unevaporated liquid chamber 19, and is discharged via the outlet 20.The unevaporated liquid is immediately mixed with the liquid to be treated A by a transfer means such as a pump and sent to the evaporator 1 again. d in the assimilation device 25.
Scale C1, asphalt D introduced from nozzle 26, heated by heater 28, and Fl't by motor 29.
s tJ, discharged from the solidified material outlet 27, filled into a container such as a drum, and left to cool to solidify. In addition, in place of the above-mentioned two-stage damper and pressure regulating chamber, if the scale is fed downward (/!) while maintaining the inside of the evaporator 1 at a predetermined degree of vacuum, it may be replaced with a rotary feeder or other means. Yes.Also, if it is not necessary to maintain direct air, there is no need to provide a damper and a single pressure chamber.Small assimilation system (1)
25 can be replaced with cement solidification or vitrification Gu in addition to the asphalt solidification device. If the amount of radioactive material is extremely small, the assimilation device 25 may not be provided, and the scale may be directly filled by replacing the container with a closed container such as a drum.

The effects of the apparatus of the present invention and its operation described above are as follows.

(1) The vertical width of each scraper 43.13a to θ scraping the heating surface 2 by the scrapers 43.13a to θ that touch the heating surface 2 upward or downward, l! : By arranging them so that they overlap, scale C
This means that a new heating surface free of adhesion is constantly prepared, and the evaporation rate is extremely high.

(2) Residence time of scale C scraped off by deploying the scraper i3, 13a-e at a predetermined angle with respect to the lead 1α line so that the lower end precedes the upper end in the direction of movement of the scraper i3, 13a-e. increases, further reducing the water content of scale C.

(3) Since the inner diameter of the heating surface 2 and the top of the funnel-shaped hopper 210 is approximately the same as the inner diameter, and the unevaporated liquid chamber 19 is provided at the bottom with a diameter larger than that of the heating surface, it is possible to 1. The scale C that has been removed easily falls into the hopper 21, and the unevaporated liquid A' flows from the heating surface 2 to the side wall of the unevaporated liquid chamber 19 and flows into the unevaporated liquid chamber without falling into the hopper. 19, scale and unevaporated liquid can be automatically separated.

(4) Since the inner surface of the hopper 21 is constantly stirred by the rotary blade 22, a small amount of water adhering to the scale C can be evaporated (5) By providing the dampers 23a, b and the pressure regulating chamber 24 I) The inside of the generator can be made into a vacuum type, which prevents radioactive materials from leaking outside, increasing safety. In addition, waste liquid containing radioactive substances that easily volatilize at high temperatures can also be treated.

(6) Water glass B depending on the evaporation dryness rate on heating surface 2
The mixing ratio of the liquid A and the liquid to be treated can be freely controlled.

In addition to the effects on the device.

(7) By adding water glass and a solidification aid to the liquid to be treated, the assimilation rate is significantly accelerated in conjunction with the effect of heating concentration, and the efficiency is increased.

(8) Solid matter, radioactive substances, etc. in the liquid are rapidly covered with polymerized silicic acid to form pellets, so that water in the liquid can be easily evaporated and separated.

(9) Since the pelletized school is made of polysilicic acid, it does not dissolve again even if it comes into contact with the unevaporated liquid, so the amount of solids in the unevaporated liquid is extremely low, and the rate of evaporation to dryness increases. The pelletized scale contains almost no moisture and water of crystallization. Therefore, it easily adheres to asphalt, resulting in a high asphalt solidification rate.

(1υ Polymerized silicic acid is a non-swelling gel, so it does not swell by absorbing the li amount of water in the asphalt, and does not create gaps with the solidified asphalt. Therefore, radioactive substances are difficult to leach out, making it safe. Of course, the effect already explained in the above-mentioned application of 〇 to effect is also included.

That is, according to the apparatus of the present invention, radioactive waste liquid can be efficiently concentrated and solidified, and the assimilation rate is high. In addition, a control circuit such as an automatic control is not required for the concentration and assimilation operation, and therefore, no complicated maintenance is required. It is extremely efficient and economical21 Furthermore, since it is a sealed type, it is safe to use volatile nuclear fli! (For example, 13'1) can be concentrated and assimilated, and a high decontamination coefficient can be obtained.Furthermore, even when asphalt is used as a fixative, almost no unevaporated water enters the asphalt. Therefore, the processing speed of assimilation is high.

The apparatus of the present invention having such effects can be applied to radioactive waste liquid concentration and solidification treatment equipment, built-up wastewater concentration and solidification treatment equipment, sludge concentration and solidification treatment equipment, etc.

[Brief explanation of the drawing]

FIG. 1 is a detailed explanatory diagram of the present invention, FIG. 2 is a sectional view taken along line E-g' of the device shown in FIG. 1, and FIG. It is 1. Shun Agent 11] Meifuku Agent Ryo Hagiwara -

Claims (1)

[Claims] 1. An apparatus for adding water glass and a solidification aid to a liquid to be treated and heating it for concentration and solidification, including: (1) an evaporator body having a substantially vertical heating surface and a steam outlet at the top; (2) an injection nozzle consisting of a double tube that is driven along the heating surface and injects the liquid to be treated and water glass onto the heating surface from the inside; (3) a scraper preceding the injection nozzle,
A scraper whose lower end always precedes its upper end in the advancing direction; (4) which receives scales scraped and falling from the heating surface disposed within the evaporator body by the scraper; (5) a hopper in which the heating surface and the inner diameter of the funnel-shaped top are formed to have approximately the same diameter; (6) a rotary blade formed at the bottom of the evaporator main body to have a diameter larger than the heating surface, and for receiving unevaporated liquid flowing down the heating surface through a gap with the outer diameter of the top of the funnel-shaped hopper; a liquid chamber; (7) means for taking out the liquid accumulated in the unevaporated liquid chamber and mixing it with the liquid to be treated; (8) a container or assimilation device connected to the hopper and receiving scale scraped from the hopper; Radioactive waste liquid concentration and assimilation processing equipment consisting of: