JPH0279000A - Device for volume reducing treatment of radioactive waste water - Google Patents

Abstract

PURPOSE:To automatically and continuously thicken a waste liquid by providing a control section which controls the waste liquid supplied from a storage tank to a waste liquid tray according to the volume of the waste liquid in a waste liquid tray. CONSTITUTION:The waste liquid tray 17 for evaporating and thickening the waste liquid is installed to the side of the storage tank 4. The waste liquid is supplied through a supply valve 18 from a waste liquid supply pot 10 into this waste liquid tray 17. The valve 18 is opened and the waste liquid is supplied from the pot 10 when the water level lowers on evaporation of the water in the waste liquid. A level sensor 14 senses the fall of the water level and a rotary drum stops when the valve 18 does not open and the water level falls further. A rotary drum heater is then turned off and a lamp is lighted in an alarm window so that an alarm buzzer sounds. The moisture in the waste liquid is evaporated form the surface of the cylindrical part of the rotary drum to thicken the waste liquid. The automatic and continuous thickening of the waste liquid is possible by continuously executing these stages.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to wastewater contaminated with radioactive isotopes, such as experimental wastewater used in experiments involving radioactive isotopes, hand washing water, organic waste incinerators, and drain wastewater. The present invention relates to a radioactive wastewater volume reduction treatment device for volume reduction treatment of radioactive wastewater.

[Conventional technology]

Nuclear power plants, research facilities and hospitals that handle radioactive isotopes, and nuclear ships discharge waste fluids containing radioactive materials.

Since this waste liquid is extremely dangerous, it is necessary to concentrate it as much as possible, store it, attenuate its radioactivity, and dispose of it in a harmless state.

Conventionally, an evaporation treatment method (volume reduction treatment method) is known as one of the methods for treating (concentrating) such waste liquid. This evaporation treatment method is especially used for low-level waste liquid treatment,
The waste liquid is concentrated by evaporating and separating a large amount of water while leaving only a minute amount of radioactive material in the waste liquid.

[Problem to be solved by the invention]

Incidentally, although low-level waste liquid has a low radioactivity level, it is discharged from a wide variety of places such as decontamination rooms, laboratories, and laundry rooms, so it is extremely large in quantity. Therefore, in order to efficiently process such a large amount of waste liquid, there has been a need for an apparatus that can automatically and continuously process such a large amount of waste liquid.

[Purpose of the invention]

This invention has been made in view of the above circumstances, and an object of the present invention is to provide a radioactive wastewater volume reduction treatment device that can automatically and continuously concentrate radioactive waste liquid.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a device main body provided inside a hood, a storage tank for storing carried-in waste liquid, and a system for evaporating and concentrating the waste liquid. A waste liquid tray, a control unit that controls the waste liquid supplied from the storage tank to the waste liquid tray according to the amount of waste liquid in the waste liquid tray, and a part of the body that is rotatable around an axis within the waste liquid tray. a rotary drum protruding above the liquid surface of the waste liquid, and a heat source for heating the body inside the drum, and a duct part provided above the waste liquid tray to discharge the generated steam to the outside of the surrounding wall. and an air heater installed in the hood to heat the air taken in from outside the hood, flowing over the body of the rotating drum, and flowing into the duct.

Further, on the side of the body of the rotating drum protruding from the liquid surface of the waste liquid, a rectifying plate is provided to cause the air heated by the heater to flow intensively over the body and into the duct part. Good too.

[For production]

In the radioactive wastewater volume reduction treatment device of this invention, the waste liquid carried into the hood is sent to a storage tank, and the amount of waste liquid supplied from the storage tank is controlled according to the amount of liquid in the waste liquid tray. The waste liquid is supplied to the waste liquid tray through the control unit, and a heated rotary drum is rotated in the waste liquid tray, and water in the waste liquid is evaporated from the surface of the body of the rotating drum and released into the atmosphere through the duct. The steps of discharging and concentrating the waste liquid are performed continuously.

In addition, since the air heated by the air heater flows into the duct with steam generated from the surface of the body of the rotating drum, the relative humidity inside the duct does not increase and the steam does not condense into dew. .

Furthermore, the flow of the air heated by the rectifying plate is rectified and flows intensively through the body of the rotating drum, so that steam generated from the body flows into the duct part more effectively.

〔Example〕

An embodiment of the radioactive wastewater volume reduction treatment apparatus of the present invention will be described below with reference to FIGS. 1 to 3.

In these figures, the reference numeral 1 indicates the hood, and the hood! A device main body 2 is installed inside. This apparatus main body 2 evaporates and separates water in the waste liquid to concentrate the waste liquid, and is constructed as follows.

That is, the storage tank 4 is installed in the frame 3 provided in the hood 1.
is provided. This storage tank 4 is supplied with waste liquid carried by a polyethylene bottle 5 by a waste liquid reception pump 6 and stored therein, and when it becomes full, a level sensor 7 detects this and a lamp lights up in an alarm window and an LW warning buzzer sounds. When the water level becomes low, the level sensor 8 senses this and the main body 2 of the device determines that the process is complete and stops automatic operation.

In addition, the waste liquid receiving pump 6 is turned on with a manual switch while monitoring the water level in the polybin 5, but when supplying waste liquid to the storage tank 4 during automatic operation, even if the manual switch is turned on, If the water level of the storage tank 4 is high,
If the level sensor 8 detects this and the pump does not start, and if the storage tank 4 becomes high or full during operation, the level sensor detects this and automatically stops the pump. .

Further, above the storage tank 4, a waste liquid supply pot IO is provided. This waste liquid supply pot! Reference numeral 0 designates an intermediate tank that supplies waste liquid from the storage tank 4 to a waste liquid supply tray, which will be described later. When the tank becomes full and the waste liquid overflows, the flow sensor 11 detects this and sends the waste liquid to the waste liquid supply pump 12.
When the engine stops, a lamp lights up in the alarm window and the fR buzzer sounds.

Further, the waste liquid supply pump I2 is connected to the waste liquid supply pot 10.
The level sensor 13 detects the water level of 0N10F.
When F is performed and the waste liquid supply pot 10 and waste liquid tray are full of water, the flow sensor 11 and the level sensor ! 4 is detected and stops, a lamp lights up in the alarm window and an alarm buzzer sounds.

Moreover, a waste liquid tray 17 for evaporating and concentrating the waste liquid is installed on the side of the storage tank 4.

This waste liquid tray 17 contains waste liquid gf! Liquid supply pot 10
When the supply is completed via the supply valve (control ff1li?lE) I8 and the water in the waste liquid evaporates and the water level drops, the supply valve 18 opens and the waste liquid is supplied from the supply pot IO, and the supply valve 18 closes. If it does not open and the water level drops further, the level sensor 14 detects this and the rotating drum (described later) stops, and the rotating drum heater turns to zero.
Now that we're on the 17th floor, a lamp lights up in the alarm window! ? [The J buzzer is now sounding.

The OL supply valve 1g is an electric valve for controlling the amount of waste liquid supplied from the waste liquid supply pot 1o to the waste liquid tray 17, and the level sensor 20 senses the water level of the waste liquid tray 17, and ON10 F F is performed. When the waste liquid tray 17 is full of water, the level sensor 14 senses this, a lamp lights up in the alarm window, and an alarm buzzer sounds.

Further, a withdrawal pipe 21 is attached to the bottom of the waste liquid tray I7 to prevent the concentrated waste liquid from being extracted from the tray 17, and this withdrawal pipe 21 is provided with a withdrawal valve 21a. Furthermore, an emergency extraction pipe 22 for emergency extraction of waste liquid is attached to the bottom of the waste liquid tray 17, and this emergency extraction pipe 22 is provided with an emergency valve 22a.

A receiving tray 23 is installed below the emergency extraction pipe 22 to receive the waste liquid to be extracted from now on and the overflowed waste liquid from the waste liquid tray I7.

Further, above the waste liquid tray 17, a shaft 25 has a bearing 2.
5a, 25a to be rotatable around an axis, and a rotary drum 26 is mounted on this shaft 25, with the lower half of its body 26a immersed in the waste liquid in the waste liquid tray I7, and the upper half protruding from the liquid surface. installed.

The surface of the body portion 26a of the rotating drum 26 is hard chrome plated and polished.

Further, heating medium oil is sealed inside the rotating drum 26, and this heating medium oil is heated by a heat transfer heater (heat source) 27 inserted from the end surface side of the rotating drum 26.
Due to this heating, the temperature of the heat medium oil gradually rises, and the heat is transmitted to the rotating drum 2G. The temperature of this heat medium oil is measured by a rotating drum thermometer 28 and automatically controlled, and its thermal expansion is absorbed by two expansion tanks.

Then, by rotating the heated rotary drum 26, water in the waste liquid is evaporated from the body 26a, and
A cake is dried and adhered to the surface of the fvf (26a, and the cake is scraped off with a blade (not shown) installed on the front surface of the body 2Ga and collected in a drum or the like.

A motor 30 with a reducer is installed on the side of the rotating drum 26, and the rotation of the motor 30 with a reducer is transmitted to the shaft 25 supporting the rotating drum 26 via a chain wheel. It has become.

Further, above the waste liquid tray 17, a waste liquid tray 17 is provided.
A duct portion 32 is provided that extends from the opening edge of the hood toward the hood 1 and collects steam. This duct part 32
A filter 33 is connected to the filter 33.
The steam from which foreign matter has been removed is discharged into the atmosphere by a blower 34.

Further, an opening 38 for taking in air from outside the hood 1 is formed in a portion of the hood 1 located on the side of the duct portion 32. A container 40 is provided. The output of this air heater 40 is automatically controlled by a hygrometer 41, and if the temperature of the air heater 40 rises abnormally, a temperature sensor 42 detects this and the air heater 40 is stopped. .

Furthermore, an inflow pipe 43 extending toward the lower end of the duct portion 32 is attached to the opening 38, and the tip of the inflow pipe 43 is connected to the lower end of the duct t'a<32. . The air taken in from the opening 3B is heated by the air heater 40, flows through the inflow pipe 43, and further flows over the surface of the body 2[3a of the rotating drum 26, and steam generated from this surface. It flows into the duct part 32 with the following.

Further, near the tip of the inflow pipe 43, a duct portion 32 is provided which passes from this portion to the vicinity of the body portion 26a of the rotating drum 26.
A curved plate-shaped rectifying plate 45 is provided that extends to the lower end of the rectifying plate 45 . This rectifier plate 45 rectifies the flow of air flowing from the inflow pipe 713 and makes it flow intensively over the body 26a, thereby more effectively directing the steam generated from the body 26a to the duct. 32.

In addition, in the case of a decrease in the flow rate of the exhaust gas in the duct section 32 or an abnormal increase in the relative humidity, the flow sensor 46 and the hygrometer 47 sense this and the apparatus comes to an emergency stop.

Next, a treatment method in the radioactive wastewater volume reduction treatment apparatus having the above configuration will be explained with reference to FIG.

The waste liquid carried in by the plastic bottle 5 is sent to the storage tank 4 by the waste liquid receiving pump 6, and then the waste liquid in this storage +fl J is sent to the waste liquid supply pot 10 by the waste liquid supply pump 12.
Water is sent to Then, from the supply pot IO to the waste tray 1
7 is supplied with waste liquid.

Next, the rotating drum 26 is rotated, and the heat transfer heater 27 is energized to heat the body portion 26a of the rotating drum 26 via the heat medium oil. Then, the waste liquid adheres to this body portion 26a, and the water in this waste liquid evaporates. And IN
The dried cake that has been dried on the surface of the portion 22a is scraped off with a blade (not shown) and collected in a drum or the like, and the waste liquid in which a certain amount of water has evaporated and is concentrated is drawn out from the extraction pipe 21. Collect in container.

Furthermore, when rotating the rotating drum 26,
Air is taken in through the opening and is heated by the air heater 40. This heated air flows through the inflow pipe 43, is rectified by the rectifying plate 45, flows intensively over the body 26a, and flows into the duct 32 with the steam generated from the body 26a.

Foreign matter is removed from the steam flowing into the duct portion 32 by a filter 33, and the steam is discharged into the atmosphere by a blower 34.

These steps are then performed continuously to automatically and continuously concentrate the waste liquid.

In addition, when the waste liquid in the storage tank 4, waste liquid supply pot IO1, and waste liquid tray 17 becomes full or at a low water level during continuous treatment of waste liquid, the level sensor 7.8, flow sensor 11. Level sensor 14.20 senses this and F! 8 Automatically perform 0N10FF of the liquid receiving pump 6, waste liquid supply pump 12, and supply valve 1g.

”Two legs? According to the radioactive wastewater volume reduction treatment device having the +11 configuration, the following effects are achieved.

■The waste liquid brought in by the plastic bottle 5 is sent to the storage tank 4, and the waste liquid is supplied from this storage WJ4 to the pot! .

This waste water supply pot! The waste liquid is supplied to the waste liquid tray 17 through the supply valve I8 which opens and closes depending on the amount of liquid in the waste liquid tray, and the heated rotary drum 26 is rotated in the waste liquid tray 17. Since water in the waste liquid is evaporated from the surface of the body portion 26a to concentrate the waste liquid, and these steps are performed continuously, the waste liquid can be automatically and continuously concentrated.

■Air is heated by the air heater 40, and this heated air flows over the surface of the body portion 26a of the rotating drum 26, and flows into the duct portion 32 with steam generated from this surface, so that the heated air flows inside the duct portion 32. It is possible to prevent steam from condensing and condensing due to high relative humidity.

■Since a rectifying plate 45 is provided that rectifies the flow of air flowing from the inflow pipe 43 and causes it to flow intensively over the body 26a of the rotating drum 26, the steam generated from the body 26a can be more effectively removed. It can be made to flow into the duct part 32.

■ Level sensor 7.8, flow sensor 11° level sensor 14, 2 that detects the fullness, high water level, or low water level of the waste liquid in the storage tank 4, waste liquid supply pot 10, and waste liquid tray 17
0 is provided, and with these, the waste liquid receiving pump 6 and the waste liquid supply pump! 2. Since ON10FF of the supply valve 18 is automatically performed, safe J rotation of the device can be performed more reliably.

〔Effect of the invention〕

As explained above, the radioactive wastewater volume reduction treatment apparatus of the present invention provides the following effects.

■Waste liquid brought in in plastic bottles etc. is sent to the storage tank,
Supplying the waste liquid from this storage tank to the waste liquid tray via a control unit that controls the supplied waste liquid q according to the amount of liquid in the waste liquid tray,
In this waste liquid tray, a heated rotary drum was rotated to evaporate water in the waste liquid from the surface of the body of the rotating drum, concentrating the waste liquid, and these steps were performed continuously. , the waste liquid can be concentrated automatically and continuously.

■The air is heated by the air heater, and this heated air flows over the surface of the body of the rotating drum and flows into the duct with steam generated from this surface, increasing the relative humidity inside the duct. This can prevent steam from condensing and condensing.

■A rectifying plate is installed to rectify the flow of heated air and direct it to flow intensively through the body of the rotating dorato, allowing steam generated from the body to flow into the duct more effectively. Can be done.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the radioactive wastewater volume reduction treatment apparatus of the present invention. Figure 1 is an explanatory diagram explaining the process flow of the apparatus, and Figure 2 is a front view of the apparatus. ,
FIG. 3 is a side view of the same. I...Hood, 2...Device body, 4.
...Storage tank, I7...Waste liquid tray, I8
...... Supply valve (control section), 26...
Rotating drum, 26a... Body, 27...
・Heat transfer heater (heat source), 32...Duct part, 4
0... Air heater, 45... Rectifier plate.

Claims (2)

[Claims] (1) Consisting of a device body and a hood surrounding the device body;
A waste liquid tray to which the waste liquid in the storage tank is supplied and for evaporating and concentrating the waste liquid, and a control for controlling the waste liquid supplied from the storage tank to the waste liquid tray according to the amount of the waste liquid in the waste liquid tray. and a rotary drum which is provided in the waste liquid tray so as to be rotatable around an axis and with a part of the body protruding above the liquid surface of the waste liquid, and which is provided with a heat source inside to heat the body. , a duct portion provided above the waste liquid tray to discharge generated steam to the outside of the hood;
Radioactive wastewater volume reduction characterized by comprising an air heater installed in the hood and heating air taken in from outside the hood, flowing over the body of the rotating drum, and flowing into the duct part. Processing equipment. (2) A rectifying plate is provided on the side of the body of the rotating drum that protrudes from the liquid surface of the waste liquid to cause the air heated by the heater to flow intensively over the body and into the duct. The radioactive wastewater volume reduction treatment apparatus according to claim 1, characterized in that: