JPS6133458B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is suitable for use in hospitals, clinics, public health centers, health centers, etc. as a chemical analysis for diagnosing diseases such as kidney disease and liver disease and for detecting medical conditions.Atomic number 53, radioisotope number 125 The hormones contained in the blood (plasma, serum) can be determined by irradiating blood taken from a patient's vein with iodine I ¹²⁵ to activate it, and measuring the intensity and half-life of its unique radioactivity. The present invention relates to a water separation method for concentrating the radioactive waste liquid left as a result of activation analysis for qualitative and quantitative determination of quantity, and an apparatus directly used for its implementation.

This type of radioactive waste liquid cannot be disposed of casually and must be stored for a strict decay period, and because the amount generated throughout the year is enormous, it is heated so that it requires less storage space. Concentration is being carried out by However, as mentioned above, iodine I ¹²⁵ is a dangerous substance that sublimes when heated and dissipates into the atmosphere, so heating it is not allowed and concentrating it is considered taboo for human health reasons. , the waste liquid had no choice but to be stored as is. Therefore, there was a problem that a large amount of storage space was required compared to waste liquid containing other radioactive substances.

Therefore, the present invention aims to provide a method and apparatus for separating water from iodine waste liquid.

The method of the present invention was developed based on the new fact that overturning the established theory regarding iodine and as a result of long-term experiments and research, we found that iodine crystallizes into a gel when heated and is not released into the atmosphere. Contrary to established theory, its features are that water is separated by heating the iodine waste liquid, and that the waste liquid is efficiently condensed by forcibly quenching the water vapor generated by heating. be.

An embodiment of an apparatus directly used for carrying out the method of the present invention will be described with reference to FIGS. 1 and 2. FIG.

The iodine waste liquid water separation device A of the present invention includes a stock tank 2 that stores radioactive waste α and whose liquid level can be freely controlled by a level controller 1, and iodine supplied from the stock tank 2 via a stock pump 3. A concentration tank 5 which accommodates the waste liquid α and has a heating means 4 such as an electric heater installed at the bottom and whose liquid level can be freely controlled by a level controller 1.
A temperature sensor 7 is attached to separate the water vapor generated in the concentration tank 5 into steam and water, surround the lower part of the outer periphery of the concentration tank 5 in a spiral shape, and send a temperature detection signal to the temperature controller 6. A refrigeration unit 10 includes a condensing pipe unit 8 that can be freely controlled, a cooling pipe 9 passing through the condensing pipe unit 8, and can be stopped in an emergency by a temperature controller 6, and a refrigeration unit 10 that passes water separated by the condensing pipe unit 8 through a carbon filter. a separated water tank 12 that introduces the water β into the previously stored water β through the condensing pipe unit 8 and recovers the water seal; a fan 13 that recirculates most of the gas separated in the condensing pipe unit 8 to the concentrating tank 5;
A charcoal filter 14 through which residual gas that has not been recirculated by the fan 13 is dissipated into the atmosphere is connected to various piping, that is, the raw solution supply piping 1.
5, organically connected by a steam extraction pipe 16, a reflux pipe 17, a drain pipe 18, and an exhaust pipe 19.

In addition, the concentration tank 5 has a level controller 1
Two level detection rods E ₁ and E ₂ with electrodes that turn on and off the stock solution pump 3 via the heating means 4
A single level detection rod E ₃ with electrodes that turns on and off and a level detection rod E ₁ suspended in the tank.
The level detection rod E ₂ detects the permissible upper limit level, the level detection rod E 2 detects the permissible lower limit level, and the level detection rod E ₃ detects the emergency level as the liquid level changes, and transmits the respective level detection signals to the level controller 1.

Furthermore, the concentration tank 5 has a container body 5a and a lid body 5b.
The lid body 5b is removably tightened with a bolt 5d with a steam leak prevention gasket 5c interposed therebetween to enable internal inspection, cleaning, and parts replacement, while the bottom plate portion 5a' of the container body 5a is A concentrated liquid outlet 5e is provided and an on-off valve 20 is attached to the undiluted liquid supply pipe 15, and a guide pipe 21 is connected vertically to the penetrating inner end of the raw liquid supply pipe 15 so that the lower end reaches near the bottom plate 5a' of the container body 5a. The extended iodic waste liquid α is prevented from jumping up on the liquid surface during supply, entering the steam extraction port 16a of the steam extraction pipe 16, and being sent to the steam extraction pipe 16.
is covered with insulation material and a thermal cover.

The condensing pipe unit 8 connects the spiral starting end of the condensing pipe 8a passing through the cooling pipe 9 of the cooling unit 10 with the lower end of the steam extraction pipe 16, and connects the spiral terminal end with the upper end of the downward drain pipe 18 and the upward reflux pipe 17. Temperature detection tubes 22...
. . are welded together to form a built-in temperature sensor 7 which is a combination of, for example, a resistance temperature detector, a thermocouple, and a thermistor, and can be optionally connected to a temperature controller 6.

The reflux pipe 17 has a connecting lower end with the same inner diameter as the condensing pipe 8a, and an upper part has a narrow diameter tube to provide a steam/water separation function, and the exhaust pipe 19 has a horizontally lower end above the charcoal filter 11 of the drain pipe 18 hanging down. are connected and raised upwards to provide air and water separation function.

In addition, in Fig. 1, 23 is a compressor, 24 is a radiator, 2
Reference numeral 5 designates an expansion valve interposed in the cooling pipe 9 at the terminal end of the condensing pipe 8a, which is opened and closed by a valve opening/closing command signal issued from a thermostat TH attached to the cooling pipe 9 at the terminal end of the condensing pipe 8a.

The operating procedure of the apparatus A of the present invention will now be explained with reference to FIG.

First, when the breaker NFB is turned on, the power light L ₁ lights up, and the level controller 1 and temperature controller 6 are also ready to start operating, and at the same time, the fan 13 that helps prevent freezing inside the condensing pipe 8a is turned on.
At the same time, heater relay R ₂ and refrigeration relay R ₃ are excited and energized to close heater relay contact R ₂ and refrigeration relay contact R ₃ , so heating operation light L ₂ is turned on and heating means 4 is turned on. Heating starts and the motor 23a of the compressor 23 is driven to start the operation of the refrigeration unit 10.

Then, the level controller 1 will issue a command signal to start the raw solution pump 3, and the pump relay will be activated.
_R1 is excited and the pump relay contact _R1 is closed, so the stock solution pump 3 is driven and the iodine waste solution α in the stock solution tank 2 is supplied from the lower end port of the guide pipe 21 of the concentration tank 5 through the supply pipe 15. Ru.

When the level detection rod E ₁ detects contact with the liquid level in the concentration tank 5, the level controller 1
The level controller 1 issues a pump stop command signal and demagnetizes the pump relay _R1 , thereby opening the pump relay contact _R1 and stopping the stock solution pump 3. Conversely, when the level detection rod _E2 detects non-contact with the liquid surface, it issues a lower limit level detection signal to the level controller 1, which issues a pump restart command signal to excite and energize the pump relay _R1. Therefore, close the pump relay contact _R1 and restart the stock solution pump 3. In this way, the stock solution pump 3 is repeatedly stopped and started, and the lower end of the level detection rod E ₁ and the level detection rod E ₂ are constantly connected.
During normal operation, the level is controlled to maintain the liquid level between the lower ends.

However, if the iodine waste solution α in the stock solution tank 2 runs out or the stock solution supply system malfunctions, the liquid level in the concentration tank 5 decreases, and in order to prevent abnormal heating by the heating means 4, non-contact with the liquid level is set. When detected by the detection rod E ₃ , an emergency level detection signal is sent to the level controller 1, and the level controller 1 issues a heating stop command signal and turns on the emergency stop or work completion light L ₃ .
At the same time as turning on, heater stop relay R ₄ is energized and energized, so heater stop relay contact R ₄ is opened and heater relay R ₂ is deenergized, heater relay contact R ₂ is opened and heating operation light L ₂ is turned on. The light is turned off and heating by the heating means 4 is stopped.

During operation, the thermostat attached to cooling pipe 9
When the TH detects supercooling of the refrigerant gas passing through the cooling pipe 9, it issues a command signal to stop the refrigeration unit 10, closes the expansion valve 25, and directly opens the thermorelay contact TH to demagnetize the refrigeration relay _R3. Then, the refrigeration relay contact _R3 is also opened to stop the operation of the motor 23a of the compressor 23 and the refrigeration unit 10. On the other hand, when the thermostat TH detects that the refrigerant gas passing through the cooling pipe 9 has returned to constant temperature cooling, it issues a command signal to restart operation of the refrigeration unit, opens the expansion valve 25, and closes the thermorelay contact TH to start freezing. When relay R ₃ is excited and energized, refrigeration relay contact R ₃ is also closed and compressor 23 motor 2 is activated.
3a and the refrigeration unit 10 are restarted.
During operation, the refrigeration unit 10 is repeatedly stopped and started to control the temperature of the refrigerant gas in the cooling pipe 9 at a constant temperature.

Furthermore, before operation, the temperature controller 6 sets the temperature inside the condensing tube 8a to the allowable limit value, that is, the lower limit temperature, for example, 5°C, which prevents expansion and bursting due to freezing inside the tube, and the upper limit temperature, for example, 40°C, which extremely reduces the condensing efficiency.
During operation, when the temperature detector 7 detects the lower limit of the temperature inside the condensing tube 8a, a lower limit temperature detection signal is sent to the temperature controller 6, and the temperature controller 6 issues an emergency stop instruction cooling signal for the refrigeration unit. Since the emergency stop relay R ₃ is demagnetized and the refrigeration relay contact R ₃ is opened, the compressor 23 is
The operation of the motor 23a and the refrigeration unit 10 are stopped immediately before the inside of the condensing pipe 8a is frozen. When the temperature detector 7 detects that the overcooling emergency situation has been lifted and the temperature inside the condensing pipe 8a has returned to within the allowable range, it issues a normal temperature detection signal to the temperature controller 6, and the temperature controller 6 cancels the emergency stop of the refrigeration unit. Emergency stop relay contact IN by issuing a finger cooling signal
By closing, the refrigeration relay _R3 is energized and closed, so the refrigeration relay contact _R3 is closed and the motor 23a of the compressor 23 and the refrigeration unit 1 are closed.
Resume 0 operation.

On the other hand, when the temperature detector 7 detects the upper limit of the temperature inside the condensing tube 8a during operation, it issues an upper limit temperature detection signal to the temperature controller 6, which issues a heater emergency stop instruction cooling signal to relay the emergency relay. By opening the contact OUT, the heater relay R ₂ is demagnetized and the heater relay contact R ₂ is also opened, so the heating operation light L ₂ is turned off and the heating of the heating means 4 is stopped. On the other hand, when the overheating emergency is canceled and the temperature detector 7 detects that the temperature of the condensing tube 8a has returned to within the allowable range, it issues a normal temperature detection signal to the temperature controller 6, and the temperature controller 6 issues a heater emergency stop release instruction cooling signal. The heater relay R ₂ is excited and energized by closing the emergency relay contact OUT, which closes the heater relay contact R ₂ and turns on the heating operation light L ₂ , at the same time restarting the heating of the heating means 4.

When the level detection rod E ₄ of the stock solution tank 2 detects contact with the liquid surface, the upper limit light (not shown) is turned on, and when the level detection rod E ₅ senses non-contact with the liquid surface, the lower limit light (not shown) is turned on. ) and turn on the level detection rod.
When E ₆ detects non-contact with the liquid surface, it lights up a warning light.

Under such operating conditions, the method of the present invention includes a first stage in which the iodine waste liquid α is heated and concentrated by the heating means 4 in a closed atmosphere in the concentration tank 5, and the water vapor generated in the first stage is sealed in the sealed atmosphere. A second stage in which steam is taken out from the atmosphere through a steam extraction pipe 16 and guided to a condensing pipe 8a and forcedly rapidly cooled and condensed in a cooling pipe 9 to separate steam and water, and most of the gas separated in the second stage is returned to a reflux pipe 17. A third stage in which the gas is sucked up by the fan 13 and refluxed into the closed atmosphere of the concentration tank 5, and the remaining gas that was not refluxed in the third stage is guided from the middle of the drain piping 18 to the exhaust piping 19, where it further promotes the separation of steam and water. A fourth stage in which the water separated in the second to fourth stages is passed through a charcoal filter 14 to adsorb odor and any iodine sublimated in the gas and then released into the outside air. The water flows concentratedly into the pipe 18, passes through the charcoal filter 11 on the way, and adsorbs any radioactive substances contained in the water, and then flows into the water from the lower end of the drain pipe 18, which extends down to the bottom plate 12a of the separated water tank 12, which has previously been filled with water β. and the fifth step of removing the water seal while preventing the gas from leaking out.

By injecting the iodine waste liquid into the concentrated liquid tank 5 and boiling it, the substances in the radioactive waste liquid except for water crystallize, and the water evaporates. This water vapor becomes water by condensing through the condensing pipe 8a...
It will be collected. At this time, in the present invention, since the water vapor is forcibly quenched using the cooling pipe and the condensing pipe, the water vapor is efficiently liquefied, and only a small amount of water vapor needs to be returned from the reflux pipe to the concentration tank. Therefore, the iodine waste liquid can be condensed efficiently. In addition, since water is collected and the gas remaining after reflux is released into the atmosphere through a charcoal filter, even if a trace amount of iodine remains in the water or gas, it will be recovered by the charcoal filter. It is designed to prevent leakage to the outside. Note that the radioactivity contained in the recovered water is at the same level as in the atmosphere.

Further, the concentrated liquid γ is taken out from the outlet 5e of the concentration tank 5 and stored in a radioactive waste storage, where its radioactivity is attenuated.

Furthermore, the separation ratio can be increased by passing the concentrated liquid through a special filter and recovering solid matter.

The present invention can reduce the volume of the iodine waste liquid by several times, so it exhibits excellent effects such as dramatically improving handling and requiring less storage space.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of the apparatus of the present invention, FIG. 2 is a detailed system configuration diagram of the air/water discharge treatment system, and FIG. 3 is an operating circuit diagram of the same. A... Iodine waste liquid water separation device, E ₁ to E ₆ ... Level detection rod, α... Iodine waste liquid, 1... Level controller, 2... Stock solution tank, 3... Stock solution pump, 4...
Heating means, 5... Concentration tank, 6... Temperature controller, 7... Temperature detector, 8... Condensing pipe unit, 9
...Cooling pipe, 10... Refrigeration unit, 11, 14... Charcoal filter, 12... Separated water tank, 13
…Fan, 15…Standard solution supply piping, 16…Steam extraction piping, 17…Recirculation piping, 18…Drain piping, 1
9...Exhaust piping.

Claims (1)

[Claims] 1. A first step in which the iodine waste liquid is heated and concentrated in a closed atmosphere, and a second step in which water vapor generated in the first step is taken out from the closed atmosphere and forcibly rapidly cooled and condensed to separate steam and water. step, and a third step in which most of the gas separated in the second step is returned to the closed atmosphere again, and the remaining gas that was not refluxed in the third step is passed through a filter to completely remove any iodine that might be contained. The water separated in the second step is passed through a filter to completely remove any iodine contained in the water, and the water is sealed in a water seal. Water separation method for iodine waste liquid. 2. The water separation method for iodine waste liquid according to claim 1, wherein in the fifth step, the water separated in the third and fourth steps is also combined and taken out as a water seal. 3. A level-controllable stock solution tank for storing iodine waste solution, a level-controllable concentration tank that accommodates the iodine waste solution fed from the active tank via a stock solution pump and equipped with a heating means at the bottom; A condensing pipe unit whose temperature can be freely controlled to separate water vapor from the water vapor generated in the concentrating tank, a refrigeration unit which cools the condensing pipe unit, and a separated water tank which recovers the water separated by the condensing pipe unit via a filter. , a fan that recirculates most of the gas separated in the condensing tube unit to the concentrating tank, and a filter that passes through the remaining gas that was not recirculated by the fan when dissipating into the atmosphere. A water separation device for iodine waste liquid that is connected to piping. 4. The water separation device for iodine waste liquid according to claim 3, wherein the condensing tube unit is equipped with a temperature detector that turns on and off the refrigeration unit and heating means via a temperature controller.