JP5892485B2 - Automatic evaporative concentrator for precipitation - Google Patents

Description

  The present invention relates to an automatic evaporation concentrator for measuring radioactivity such as precipitation fallout.

Radioactivity is released into the atmosphere due to an accident at TEPCO's nuclear power plant, and contamination from ground crops, sports grounds, etc. due to the radiation from the precipitation is detected. Interest increased all at once. Radioactivity measurement of precipitation fallout has been carried out in the Institute of Health of the National Nuclear Center and each region based on the even of Education, Culture, Sports, Science and Technology Ministry standard measurement manual so far.

  According to the manual method for measuring radioactivity of precipitation fallout, first, the total amount of tens to hundreds of liters of stored precipitation fallout (hereinafter sometimes referred to as sample water) is stored in a 100 ml measuring container. Is concentrated by evaporation.

  However, since the operation of evaporating and concentrating the water uses an electric heater such as a red hot nichrome wire heater, it is necessary to monitor it for fire prevention and is limited to the daytime operation during the working hours of the staff. For this reason, even if, for example, four electric heaters are used for the operation of evaporating and concentrating precipitation fallout, it usually takes about two weeks.

  In addition, it is necessary to manually replenish the beaker with sample water by evaporation operation using a large beaker, etc., and it is easy to cause troubles such as breakage of the beaker due to emptying, and not only is the operation complicated. Since a large amount of water is evaporated by heating, it is necessary to discharge moisture to the outdoors by working in a draft chamber.

  In the prior art, as an automatic concentrator that automatically concentrates a sample solution for concentration considered to be a relatively small amount, a heated water tank set with a ready-made rotary evaporator containing the sample solution is used under reduced pressure. Japanese Patent Application Laid-Open No. 2000-189706 and Japanese Patent Application Laid-Open No. 5-273196 disclose a device for distilling a solvent, continuously supplying a sample liquid based on the amount of decrease in the weight of a heated water tank, and automatically concentrating. .

  The present inventor has also developed the pioneering automatic evaporative concentrator for the measurement of radioactivity of the present invention (Non-Patent Document 1 and Non-Patent Document 2).

JP 2000-189706 A JP-A-5-273196 Masaaki Saito Tokuo Kato “Development of Automatic Evaporating Concentrator for Precipitation Fallout Radioactivity Measurement” Radioisotopes, Vol. 55, No. 4, pp. 189-194 (2006) Masaaki Saito Research Report, Tokyo Metropolitan Industrial Technology Research Center "Development of Automatic Evaporative Concentrator for Precipitation Radioactivity Measurement" No. 1, pp. 62-65 2006

  The radioactivity measurement method of precipitation fallout based on the above-mentioned MEXT standard measurement manual required a long and simple manual operation to concentrate a large amount of sample water.

  The automatic sample solution concentrators described in Patent Documents 1 and 2 are based on the weight measurement of the sample solution concentrator, and require a ready-made aspirator outside to achieve a reduced pressure state. However, it is not an infinite continuous system that discharges condensed water directly to the outside, and it is not suitable for evaporating and concentrating a large amount of precipitation.

  Further, in the automatic evaporation concentrator described in Non-Patent Documents 1 and 2, it is not easy to make the airtightness perfect with a configuration in which sample water is supplied to the rotary evaporator from the precipitation tank by using a tube pump. Since it is not a fully automated system, but also a configuration using a commercially available external aspirator, the overall size is large and the structure does not exceed the existing concept.

  The object of the present invention is to further improve the above-described automatic evaporative concentrator of the present inventor, and with a simple structure, it is possible to automate sample water such as precipitation fallout radioactivity measurement capable of evaporating and enriching a large amount of precipitation fallout safely. It is to provide an evaporative concentrator.

The present invention has the following configuration in order to solve the above problems.
According to the first aspect of the present invention, there is provided a sample water tank (1) in which sample water containing precipitation fallout is stored, and a sample water container (10) for distilling the sample water supplied from the sample water tank (1) under reduced pressure. And a sample water supply pipe (11) for heating the sample water container (10) and a sample water supply valve (14) for connecting the sample water tank (1) and the sample water container (10). 9), an aspirator built-in pipe (15) for depressurizing the internal closed space by a water flow connected to the top of the sample water container (10), and a sample water tank disposed at the bottom of the sample water tank (1) (1) A first water detection sensor (S1) for detecting the presence or absence of sample water, an all current relay (7) provided between the first water detection sensor (S1) and the power source, and an all current relay ( 7) a first electric circuit (A) for controlling opening and closing, and a predetermined water in the sample water container (10) And a second water detection sensor (S2) for detecting whether or not a predetermined amount of sample water is present in the sample water container (10), and between the second water detection sensor (S2) and the power source. a second electrical circuit for controlling opening and closing of the sample water supply valve (14) which is provided (B), said aspirator internal pipe (15) incorporates a is and the water flow pipe through which cooling water flows aspirator (15c), The water flow from the lower end of the water flow pipe (15c) and all the condensed water distilled from the sample water container (10) and condensed on the outer wall of the water flow pipe (15c) by cooling are received and penetrated through the bottom wall surface of the aspirator built-in pipe (15). Then, the water flow discharge pipe (15d) that discharges to the outside from the decompression system to the normal pressure system, and the top wall surface of the aspirator built-in pipe (15) pass through the opening end on the outside and inside of the aspirator built-in pipe (15). A pipe with a built-in aspirator 15) An airtight open pipe (19) having an airtight open valve (20) attached to the outside is connected to the first electric circuit (A) and the second electric circuit (B), and the airtight open valve (20) is connected. When the first water detection sensor (S1) detects that there is no sample water in the sample water tank (1), the all current relay (7) By turning off, the entire evaporative concentrator automatically stops, the airtight release valve (20) is opened, the decompressed state inside the aspirator built-in pipe (15) is released, and the second water detection sensor (S2). However, when it is detected that there is no predetermined amount of sample water in the sample water container (10), the sample water supply valve (14) is opened and the sample water container (1) 10) Sample water is supplied to It is an evaporation concentrator for precipitation fall.

Invention of Claim 2 provides the cooling water supply piping (25) which has a cooling water feed valve (26) which supplies a cooling water to the water flow pipe (15c) of the aspirator built-in pipe (15), The 3rd electric circuit (C) is configured to control the opening and closing of the cooling water supply valve (26). When the all-current relay (7) is turned on, the airtight opening valve (20) is closed and the cooling water supply valve (26 ) Is opened, the inside of the aspirator built-in pipe (15) is depressurized, and the first water detection sensor (S1) detects that there is no sample water in the sample water tank (1), and The precipitation fallout according to claim 1, characterized in that when the current relay (7) is turned off, the airtight opening valve (20) is opened and the cooling water supply valve (26) is closed . Evaporative concentrator.

  According to the first aspect of the present invention, when there is no sample water in the sample water container (10) or when the sample water is reduced and only the second water detection sensor (S2) is turned off, the sample water is supplied. Since the valve (14) is opened and the inside of the aspirator built-in pipe (15) and the sample water container (10) are in a reduced pressure state, the sample water in the sample water tank (1) is supplied from the sample water feed pipe (9). It is automatically sucked into the tank (1).

  Further, when there is sample water in the sample water container (10) by an amount that turns on the second water detection sensor (S2), the sample water supply valve (14) is closed, and again in the sample water container (10). When the sample water is decreased and the second water detection sensor (S2) is turned off, the sample water supply valve (14) is opened, and the sample water is supplied from the sample water tank (1) into the sample water container (10) under reduced pressure. Supplied.

  Further, when the sample water in the sample water tank (1) decreases and the first water detection sensor (S1) is turned off, the all power relay (7) is turned off, and the entire evaporation concentrator is automatically stopped.

  Also, if for some reason the full power supply or the full power supply relay (7) is turned off, the entire evaporative concentrator is automatically stopped to open the hermetic release valve (20) and the decompressed state in the aspirator built-in pipe (15) is released. The evaporation process is safely stopped while the sample water is maintained in the sample water tank (1) or the sample water container (10).

In addition, the aspirator built-in pipe (15) of the present invention cools and condenses the decompressed steam as it is by the water flow of the water pipe used as the aspirator used to bring the inside of the aspirator built-in pipe (15) and the sample water container (10) into a depressurized state. The main feature is that it is discharged outside the atmospheric pressure along with the water flow.

Then , by using a ready-made aspirator component that passes through the bottom wall surface of the aspirator-incorporated pipe (15) and discharges the water flow to the outside, not only the inside of the aspirator-incorporated pipe (15) but also the inside of the sample water container (10) is decompressed. Thus, the sample water in the sample water container (10) can be easily distilled under reduced pressure, and at least a part of the steam distilled from the sample water in the sample water container (10) is contained in the aspirator built-in pipe (15). Condensed on the outer wall surface of the water flow pipe (15c) at the top of the water, the condensed water obtained and the uncondensed steam pass through the water flow discharge pipe (15d) and are easily discharged from the aspirator built-in pipe (15). As a result, evaporation and concentration of the sample water in the sample water container (10) can be easily performed with an unlimited amount of treatment.

  According to the first aspect of the present invention, high-speed evaporation of water is possible at a low temperature of 100 ° C. or less by the pressure reducing action by the aspirator-containing pipe (15).

  When the sample water in the sample water container (10) decreases due to distillation, the sample water in the sample water tank (1) automatically enters the sample water container (10) via the sample water supply pipe (9). Since it is supplied, the sample water can be continuously evaporated and concentrated.

  When the sample water in the sample water tank (1) decreases and the first water detection sensor (S1) is turned off at the end of the entire process, the entire power supply relay (7) is turned off, and the entire evaporation concentrator is automatically If the entire power supply or all power supply relay (7) is turned off for some reason, the entire evaporative concentrator automatically stops, enabling unattended continuous operation of a large amount of sample water day and night, greatly reducing labor. be able to. Then, the radioactivity etc. of the obtained concentrated water can be measured easily.

According to the second aspect of the present invention, even a large amount of sample water can be activated and stopped continuously and safely for a long time. In addition, the present invention is not limited to precipitation fallout, and can easily analyze concentrate components contained in other large amounts of aqueous solutions.

It is the whole structure except the aspirator built-in pipe part of the automatic evaporation concentrator of one Example of this invention. It is a detailed block diagram of the aspirator built-in tube and sample water flask of one Example of the automatic evaporation concentrator of FIG.

An embodiment of the present invention will be described with reference to the drawings.
In the normally open type and normally closed type of the electromagnetic valve shown in this embodiment, on-off reverse drive can be easily achieved by other electronic circuits. Although this embodiment is an example of the normally closed type, the operation is the same. If it becomes a result, it will not be limited to a normally closed type. In addition, as an example of detecting water conductivity as a water detection sensor, there are various methods for detecting the water surface, such as optical, dielectric, magnetic, and float contacts. If it operates, the method is not limited. Furthermore, since the same result can be obtained by converting the sensor signal into the driving operation in the drive circuit of the electromagnetic valve and the magnetic relay, the present invention is not limited to the transistor, the IC, etc. as well as the FET shown in this embodiment. In other words, the present invention does not present novelty for water detection, drive circuitry and aspirator components, but rather shows a system using these existing components and a novel evaporator incorporating the aspirator.

  Note that pressure reduction and suction operations by an aspirator have been widely used, and the principle and mechanism are known and will not be described in detail.

  FIG. 1 shows the overall configuration of the automatic evaporative concentrator for the precipitation fallout radioactivity measurement of this embodiment, excluding the aspirator built-in tube portion.

  One month's amount of precipitation fallen in a receptacle (not shown) for precipitation fallout placed on the open-air is transferred to the sample water tank 1. In addition, when one sample water tank 1 is insufficient, it can respond even if sample water increases by connecting the some sample water tank 1 with a siphon.

  A first water detection sensor S1 including a pair of electrode terminals based on water conductivity is disposed at the bottom of the sample water tank 1. The first water detection sensor S1 is connected to all power supply relays 7 of a pair of electric wires a and b through which a 100V AC current flows through a bridge circuit 2 of a DC electric circuit A and a solenoid coil part 3 of an electromagnetic relay. .

In addition, precipitation fallout in the sample water tank 1 is supplied to the sample water flask 10 via the sample water supply pipe 9. The sample water flask 10 is immersed in a water bath 11, and the water in the water bath 11 is heated at a constant temperature to about 60 ° C. by a heater 13 immersed in the water. A so-called rotary evaporator that is rotated as a whole by a rotator (not shown) is suitable for the sample water flask 10 as an evaporator, and is immersed in the water bath 11.
The sample water flask 10 for distillation under reduced pressure can use any appropriate size and constituent material according to the capacity and workability of the sample water. For example, a sample water container such as a metal can be used. .

Sample water supply pipe 9 normally open type (the "normally closed type""open" when turned on a current flows through the solenoid coil valve NC Norma leakage Roz type, "normally open type" when the solenoid coil is turned on "Close" valve NO normally open.) Electromagnetic sample water supply valve 14 is attached, and the water supply pipe 9 on the sample water flask 10 side of the sample water supply valve 14 is in the aspirator built-in pipe 15 To reach the sample water flask 10. The inside of the sample water flask 10 can be depressurized by the pressure reducing action by the aspirator built-in tube 15. When the sample water supply valve 14 is opened, the sample water in the sample water tank 1 is directed toward the sample water flask 10 under reduced pressure. The sample water in the sample water flask 10 which has been sucked and heated in the water bath 11 is evaporated and concentrated by the pressure reducing action and heating by the aspirator built-in tube 15.

  Further, a second water detection sensor S2 comprising a pair of electrodes utilizing the conductivity of environmental water containing dissolved components is disposed at a predetermined position in the sample water flask 10, and the second water detection sensor S2 is a bridge circuit. The open / close solenoid coil portion 18 of the sample water supply valve 14 is formed via 17. An electric circuit including the bridge circuit 17 and the solenoid coil unit 18 is referred to as an electric circuit B.

  1 shows an AC electric circuit C in which an AC current of 100 volts flows between the electric wires 5 and 6. Between the electric wires 5 and 6, a heater 13 and a water flow pipe 15c (FIG. 2) used in the water bath 11 are shown. ) Supplying the cooling water supplied into the aspirator pump 22 for making the water flow and the solenoid coil part 23 for opening and closing the normally open type airtight opening valve 20 provided in the airtight opening pipe 19 and the water flow pipe 15c (FIG. 2) A solenoid coil portion 27 for opening and closing a normally closed cooling water supply valve 26 provided in the cooling water supply pipe 25 is disposed. The AC electric circuit C and the electric circuits A and B in FIG. 1 are as shown in (a), (a), (b), (b), (c), (c), and (d). , (D) indicate that they are connected to each other.

FIG. 2 is a detailed configuration diagram of the aspirator built-in tube 15 and the sample water flask 10.
A sample water supply pipe 9 extending from the inside of the sample water tank 1 penetrates the inside of the aspirator built-in pipe 15 and reaches the inside of the sample water flask 10, penetrates the top wall surface of the aspirator built-in pipe 15, and extends vertically in the inside. Further, a water flow discharge pipe 15d for discharging the water flow pipe 15c and the aspirator built-in pipe 15 from the bottom bottom end of the water flow pipe 15c is provided. A water flow is supplied from the cooling water supply pipe 25 to the water flow pipe 15c.

Through the top wall of the aspirator internal tube 15 has an open end to the outside and the inside of the aspirator internal tube 15, and air-tight open tube fitted with a normally open airtight opening valves 2 0 outside the aspirator internal tube 15 When a high-speed water flow flows into the water flow pipe 15 c of the aspirator built-in pipe 15 having 19, the internal space of the aspirator built-in pipe 15 and the sample water flask 10 is in a reduced pressure state.

  On the other hand, a part of the sample water vapor in a reduced pressure distilled from the sample water flask 10 is condensed on the outer wall surface of the water flow pipe 15c cooled by the water flow. Thus, the water flow pipe 15c also functions as a condenser during vacuum distillation.

The present embodiment is characterized in that a condenser function and a decompression function by a high-speed water flow can be obtained simultaneously by a combination of the water flow tube 15c and the water flow discharge tube 15d in the aspirator built-in tube 15. In addition, in the case of the configuration shown in FIG. 2, the high-speed water flow in the water flow pipe 15c is directly discharged from the aspirator built-in pipe 15 to the outside of the decompression system via the water flow discharge pipe 15d.

When starting the operation of the automatic evaporation apparatus of the present embodiment having the above structure, first, in advance sample water stored in the sample water tank 1, the first water sensing sensor S1 of electrical circuit A The operator is allowed to operate, and the operator manually turns on an electromagnetic switch (not shown) for operating all the power relays 7. When all the power supplies are turned on, the on state of all the power relays 7 is maintained. At the start of operation, there is no sample water in the sample water flask 10 and the second water detection sensor S2 is not conductive, so the normally open sample water supply valve 14 of the sample water supply pipe 9 is open.

  When the power is turned on by the all power supply relay 7, the heater 13 for the water bath 11 is heated, and the aspirator pump 22 is also operated to flow a high-speed water flow from the cooling water supply pipe 25 into the water flow pipe 15c. 15 and the sample water flask 10 are in a reduced pressure state. The normally open type airtight opening valve 20 is also closed because the solenoid coil 23 is operated.

  Then, the sample water in the sample water tank 1 is supplied to the sample water flask 10 via the sample water supply pipe 9 and the aspirator built-in pipe 15 under reduced pressure. The sample water is sucked into the sample water flask 10 from the sample water tank 1 until the first water detection sensor S1 is not activated.

When the sample water flowing into the sample water flask 10 accumulates up to the pair of electrode terminals of the second water detection sensor S2, the pair of electrodes of the second water detection sensor S2 conducts, and the solenoid coil 18 of the electric circuit B is activated. Since the normally open type sample water supply valve 14 is closed, the water supply from the sample water tank 1 to the sample water flask 10 is stopped, and the flask is always kept at a constant water level.

When the sample water sample water flask 10 is evaporated from the sample water supply pipe 9 flows into the aspirator internal tube 15, a portion in the outer wall surface of the water flow tube 15c is condensed, water discharge pipe 15d from the water flow pipe 15 c The steam enters the inside of the water and is discharged to the outside of the aspirator built-in pipe 15 together with the water flow flowing in the water flow discharge pipe 15d.

  Next, when the sample water in the sample water flask 10 evaporates and the water level drops below the position where the second water detection sensor S2 is installed, the second water detection sensor S2 is turned off. The sample water supply valve 14 is opened. At this time, since the inside of the sample water flask 10 is in a reduced pressure state, the sample water from the sample water tank 1 is supplied again into the sample water flask 10 via the sample water supply pipe 9. When a specified amount of sample water is stored again in the sample water flask 10, the second water detection sensor S <b> 2 is reactivated, the sample water supply valve 14 is closed, and the sample water is supplied from the sample water tank 1 to the sample water flask 10. Will automatically stop. This operation is automatically repeated until there is no sample water in the sample water tank 1.

As long since while there are water sample first water detection sensor S1 of the sample water tank 1 is operating the electrical circuit C is operating in the sample water tank 1, a water bath heater 13 and the water flow forming The aspirator pump 22 is activated, the solenoid coils 23 and 27 are activated, the normally open type airtight release valve 20 is closed, the normally closed type cooling water supply valve 26 is opened, and the water flow pipe 15c in the aspirator built-in pipe 15 is opened. A high speed water flow is supplied from the cooling water supply pipe 25.

When the sample water of sample water tank 1 is concentrated by evaporation of all the water sample successfully delivered to the water sample flask 10 ends, electrical circuit because no current flows through the solenoid coil portion 3 of the A total power relay 7 Is cut off.

When all the power is turned off and the current in the electric circuit C is cut off, the heater 13 and the aspirator pump 22 of the water bath 11 are deactivated, the normally closed cooling water supply valve 26 is closed, and the solenoid coil portion 23 is turned off. The water flow stops. Further, the solenoid coil portion 23 is turned off, the normally open type airtight opening valve 20 is opened, the inside of the aspirator built-in tube 15 returns to normal pressure, and the reduced pressure state in the sample water flask 10 is released. When the all power supply relay 7 is turned off in this way, the automatic evaporative concentrator does not automatically resume operation other than manual operation.
In addition, all the power relays 7 are turned off at the time of abnormal termination such as a power failure.

  As described above, the automatic evaporative concentrator of this embodiment can be operated and stopped automatically and continuously for a long time even with a large amount of sample water exceeding 100 liters. Further, by increasing the scale of the concentrator, the processing capacity can be increased as much as possible within a common sense range.

  In particular, it is possible to automatically evaporate and concentrate rainwater contaminated with radioactivity as sample water, so that radioactivity can be measured quickly.

  The present invention has high applicability because it allows automatic evaporation and concentration of precipitation deposits by manual operation, which has conventionally been troublesome.

DESCRIPTION OF SYMBOLS 1 Sample water tank 2, 17 Bridge circuit 3, 18, 23, 27 Solenoid coil part 5, 6 Electric wire 7 Full power relay 9 Sample water supply piping 10 Sample water flask 11 Water bath 13 Heater 14 Normally open type sample water supply valve 15 Aspirator built-in pipe 15c Water flow pipe 15d Water flow discharge pipe 19 Airtight open pipe 20 Normally open type airtight open valve 26 Normally closed type cooling water feed valve 22 Aspirator pump 25 Cooling water supply pipe S1 First water detection sensor S2 Second water detection sensor A , B, C Electrical circuit

Claims (2)

A sample water tank in which sample water containing precipitation deposits is stored;
A sample water container for vacuum distillation of the sample water supplied from the sample water tank;
A heated water tank for heating the sample water container;
A sample water supply pipe having a sample water supply valve for connecting the sample water tank and the sample water container;
A pipe with a built-in aspirator for reducing the internal closed space by a water flow connected to the top of the sample water container;
A first water detection sensor disposed at the bottom of the sample water tank and detecting the presence or absence of the sample water in the sample water tank;
An all-current relay provided between the first water detection sensor and the power source;
A first electric circuit for controlling opening and closing of the all-current relay;
A second water detection sensor disposed at a predetermined position in the sample water container and detecting whether or not a predetermined amount of sample water is present in the sample water container ;
A second electrical circuit for controlling opening and closing of the sample water supply valve provided between the second water detection sensor and a power source,
The aspirator built-in pipe is an aspirator and incorporates a water flow pipe through which cooling water flows, receives all the condensed water condensed from the water flow from the lower end of the water flow pipe and the sample water container and condensed on the outer wall of the water flow pipe by cooling, A water discharge pipe that passes through the bottom wall of the aspirator built-in pipe and discharges from the decompression system to the normal pressure system, and has an open end on the outside and inside of the aspirator built-in pipe through the top wall of the aspirator built-in pipe. And an airtight open pipe with an airtight open valve attached to the outside of the aspirator built-in pipe,
A third electric circuit connected to the first electric circuit and the second electric circuit for controlling opening and closing of the airtight opening valve;
When the first water detection sensor detects that there is no sample water in the sample water tank, the entire current relay is turned off, so that the entire evaporation concentrator is automatically stopped and the airtight release valve is opened. The decompressed state inside the aspirator built-in pipe is released,
When the second water detection sensor detects that there is no predetermined amount of sample water in the sample water container, the sample water supply valve is opened and sample water is transferred from the sample water tank to the sample water container. Evaporative concentrator for precipitation fall, characterized in that it is supplied . A cooling water supply pipe having a cooling water supply valve for supplying cooling water to the water flow pipe of the aspirator built-in pipe is provided,
The third electric circuit has a configuration for controlling opening and closing of the cooling water supply valve,
When the all current relay is turned on, the airtight opening valve is closed and the cooling water supply valve is opened, and the inside of the aspirator built-in pipe is in a reduced pressure state.
When the first water detection sensor detects that there is no sample water in the sample water tank and the all current relay is turned off, the airtight release valve is opened and the cooling water supply valve is closed. evaporative condenser according to claim 1 precipitation fallout, wherein the as the.

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