JP2001108791A - Liqiud scintillator waste-liquid inclinerating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid scintillator waste-liquid incinerating device capable of safely combusting liquid scintillator waste-liquid to reduce its volume. SOLUTION: This device is equipped with a waste liquid tank 11 for storing liquid scintillator waste-liquid, an incinerator 12 kept at 800 deg.C or higher for combusting the waste liquid injected thereinto from the tank 11 with supplied combustion air, a cooler 13 for cooling combustion gas produced in the incinerator 12 down to 200 deg.C or lower and having a dust box 55 for collecting dust in the combustion gas, a venturi scrubber 14 for cooling the combustion gas cooled by the cooler 13 down to 100 deg.C or lower, a neutralizing tower 15 for bringing the cooled gas from the scrubber 14 into contact with a nautralizer to remove harmful matters such as HCl and SOx prior to discharge, and a package 10 for housing the tank 11, the incinerator 12, the cooler 13, the scrubber 14, and the tower 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid scintillator waste liquid incinerator.

[0002]

2. Description of the Related Art Liquid scintillator effluents, which are radioactive wastes generated by the use of radioactive substances used for medical purposes, contain H-3, C-14, P- as radioisotopes.
32, P-33, S-35, Ca-45 and the like, which are discharged from the hospital as waste liquid mixed with toluene or methanol.

Conventionally, the treatment of this liquid scintillator waste liquid has been entrusted to a specialized company.

[0004]

However, since the discharged liquid scintillator is discharged in a large amount, various problems such as ensuring the safety during storage and the security during transportation are required for processing. is there.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a liquid scintillator waste liquid incinerator capable of reducing the volume by safely burning the liquid scintillator waste liquid.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a waste liquid tank containing a liquid scintillator waste liquid and a liquid scintillator waste liquid in the waste liquid tank are injected and supplied. 80 with combustion air
An incinerator for burning at a temperature of 0 ° C. or more, and a cooler having a dust box for cooling combustion gas generated in the combustion furnace to 200 ° C. or less and collecting dust in the combustion gas;
A liquid scintillator waste liquid incinerator comprising a venturi scrubber for cooling and exhausting the combustion gas cooled by the cooler to 100 ° C. or lower, and a package containing the waste liquid tank, incinerator, cooler and venturi scrubber.

According to a second aspect of the present invention, there is provided an incinerator for storing a liquid scintillator waste liquid, an incinerator for injecting the liquid scintillator waste liquid in the waste liquid tank and burning it at 800 ° C. or more with supplied combustion air. A cooler having a dust box for cooling combustion gas generated in the combustion furnace to 200 ° C. or less and collecting dust in the combustion gas; a venturi scrubber for cooling the combustion gas cooled by the cooler to 100 ° C. or less; The cooling gas from the venturi scrubber is brought into contact with a neutralizing agent to produce HC.
A liquid scintillator waste liquid incinerator comprising a neutralization tower for removing and exhausting harmful substances such as l, SOx, etc., and a package containing the waste liquid tank, incinerator, cooler, venturi scrubber and neutralization tower. .

A third aspect of the present invention is a waste liquid tank containing a liquid scintillator waste liquid, and an incinerator in which the liquid scintillator waste liquid in the waste liquid tank is injected and burned at 800 ° C. or more with the supplied combustion air. A liquid scintillator comprising: a venturi scrubber that blows a combustion gas generated in a combustion furnace together with a neutralizing agent into a water scrubber to cool the exhaust gas to 100 ° C. or lower and exhausts the exhaust gas; It is a waste liquid incinerator.

According to a fourth aspect of the present invention, there is provided an incinerator for holding a liquid scintillator waste liquid, an incinerator for injecting the liquid scintillator waste liquid in the waste liquid tank, and burning the liquid scintillator at 800 ° C. or more with supplied combustion air. A venturi scrubber that blows the combustion gas generated in the combustion furnace together with a neutralizing agent into a water scrubber to cool it to 100 ° C. or lower, and further contacts the cooling gas from the venturi scrubber with the neutralizing agent to remove HCl contained in the gas. A liquid scintillator waste liquid incinerator comprising a neutralization tower for removing and exhausting harmful substances such as SOx, and a package containing the waste liquid tank, the incinerator, the venturi scrubber and the neutralization tower.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a package for housing the entire apparatus. In the package 10, a waste liquid tank 11 for housing a liquid scintillator, a combustion furnace 12 for burning the liquid scintillator, and exhaust gas from the combustion furnace 12. A cooler 13 for cooling, a scrubber 14 for further cooling the gas from the cooler 13, a neutralization tower 15 for neutralizing harmful substances in the gas from the scrubber 14, and a gas from the neutralization tower 15 are further cooled. The sub cooler 16 is accommodated.

The waste liquid tank 11 is provided with a liquid scintillator waste liquid inlet 17, a waste liquid pump 18 for supplying the liquid scintillator waste liquid from the waste liquid tank 11 to the combustion furnace 12, and a waste liquid supply line 2 connected to the waste liquid pump 18.
0 is connected, and the line 20 is connected to a burner 21 provided in the combustion furnace 12.

The waste liquid supply line 20 has an on-off valve 2
2. A flow regulating valve 23 is connected, and a bypass line 24 for returning a part of the waste liquid from the pump 18 to the waste liquid tank 11 is connected between the on-off valve 22 and the waste liquid pump 18, and a pressure regulating valve 25 is connected to the line 24. Connected waste liquid supply line 20
The pressure of the waste liquid supplied to the tank is kept constant, and the entire amount of the waste liquid can be returned to the waste liquid tank 11 when the flow control valve 23 is closed.

A pilot burner 26 is provided in the fuel injection section 19 below the incinerator 12 in addition to the burner 21 for injecting the liquid scintillator waste liquid.
An air supply line 28 from the pushing fan 27 is connected to 6, and a fuel gas supply line 30 such as city gas is connected to the air supply line 28.

An on-off valve 31 and a flow control valve 32 are connected to the fuel gas supply line 30.
Is connected to a flow control valve 33.

At the bottom of the combustion furnace 12, a pan 34 for receiving incineration ash is provided. At the bottom of the combustion furnace 12, a spray nozzle 35 for controlling the combustion temperature is provided. Air supply line 28
Is connected to the air line 36, and a flow regulating valve 37 is connected to the air line 36.

The upper portion of the combustion furnace 12 is provided with a combustion gas outlet 38, and the outlet 38 is connected to the cooler 1 through a line 39.
3 is connected. The pressure gauge 29 is connected to the line 39.

The combustion furnace 12 is provided with a thermometer 40 for detecting the temperature of the combustion gas, and the flow rate adjusting valves 32, so that the temperature of the combustion gas becomes 800 ° C. or more, preferably 850 ° C. 33 and 37 are controlled.

The cooler 13 has a plurality of heat transfer tubes 43 provided in a cooler body 42, and the upper end of the heat transfer tubes 43 is connected to a flash drum 44 provided on the cooler body 42.
The lower end is connected to a water supply drum 45 provided outside the cooler main body 42. A return line 46 for returning condensed water to the water supply drum 45 is connected to a lower portion of the flash drum 44, and a steam line 47 is connected to the upper portion. A condenser 48 and a circulation pump 49 are connected to the steam line 47, and the circulation The pump 49 returns condensed water to the water supply drum 45.

A water supply line 50 and a return line 51 are connected to the condenser 48, and a flow control valve 52 is connected to the water supply line 50, and the flow control valve 52 is controlled by a pressure gauge 53 provided on the flash drum 44. Under the control, the amount of water supplied to the condenser 48 is adjusted.

A dust box 55 for collecting dust contained in the combustion gas is connected to the bottom of the cooler body 42. The gas cooled by the cooler body 42 is supplied to the line 5.
6 to the venturi scrubber 14.

The venturi scrubber 14 is formed by providing a water scrubber 57 with a venturi nozzle 58.
The tip of the venturi nozzle 58 is provided with a water scrubber 57.
The tip is formed jagged so as to be below the surface of the water and not to increase the bubbles blown out from the nozzle 58.

The venturi scrubber 14 is connected to the connecting pipe 6.
The gas from the venturi scrubber 14 is supplied to the neutralization tower 15 via a zero.

The neutralization tower 15 is provided with a contact layer 63 filled with a packing for gas-liquid contact in a tower main body 62, and a demister 64 provided thereon. In addition, spray pipes 65, 65 for spraying the neutralizing solution to the contact layer 63 and the mist eliminator 64, respectively, are provided.

A sub-cooler 16 is connected to a line 66 at the top of the neutralization tower 15 via an induction fan 67, and an exhaust line 70 for exhausting gas out of the package 10 is connected to a lower portion of the sub-cooler 16. .

The induction fan 67 has its motor 68 driven by the inverter 69 and operates according to the detection value of the pressure gauge 29 connected to the line 39 of the incinerator 12.
Reference numeral 9 controls the pressure of the cooler 13 by controlling the amount of exhaust air from the induction fan 67.

The sub-cooler 16 is connected to a cooling water line 72 branched from the water supply line 50 via an on-off valve 71 and a drain line 73, and the drain line 73 is returned via an on-off valve 74. Connected to line 51.

The condensed water in the sub cooler 16 is supplied to a line 75,
The liquid is returned to the neutralization tower 15 via the on-off valve 76. A U-shaped pipe 77 is formed in the line 75, and the condensed water is stored in the U-shaped pipe 77 so that the gas from the sub-cooler 16 can flow to the exhaust line 70 without flowing to the line 75.

A make-up water line 79 for supplying water from the water supply line 50 to the neutralization tower 15 via an on-off valve 78 is branched and connected, and a flow control valve 80 and an on-off valve 81 are connected to the make-up water line 79. .

A liquid level introduction tank 82 for introducing the liquid in the neutralization tower 15 is connected to the neutralization tower 15, and a liquid level meter 83 is provided in the liquid level introduction tank 82. The liquid level of the liquid level introduction tank 82, that is, the liquid level of the neutralization tower 15 is measured, and the flow rate adjusting valve 80 is controlled so that the liquid level becomes a set value. The neutralization tower 15 and the liquid level introduction tank 82 are connected so as to communicate below the liquid level with a liquid line 83 and communicate above the liquid level with a gas line 84.

Drainage lines 86 and 87 are connected to the bottom of the neutralization tower 15 and the bottom of the liquid level introduction tank 82, respectively, and are collected in a drainage tank 88.

At the bottom of the venturi scrubber 14,
A discharge line 90 is connected, and the discharge line 90 is joined to a neutralizing agent supply line 92 connected to a neutralizing agent tank 91, and is connected from a neutralizing agent line 95 via a filter 93 and a pump 94 to a flow control valve 96. , 96 via spray tube 6
5,65. Further, a neutralizing agent injection line 97 is branched off from the neutralizing agent line 95, and the line 97
The neutralizing agent is injected into the incinerator 12 together with the air from the air line 36 connected to the spray nozzle 35 of the incinerator 12 by a flow control valve 98 connected to the incinerator 12.

A pH meter 99 is connected to the neutralizing agent line 95, and the flow rate adjusting valve 100 connected to the neutralizing agent supply line 92 is controlled in accordance with the pH value to control the amount of the neutralizing agent mixed. It has become.

The neutralizing agent line 95 is connected to a line 101 which branches off from the neutralizing agent line 95 and supplies a neutralizing agent to the venturi scrubber 14.
1 is connected to a flow control valve 102.

The neutralizing agent in the neutralizing agent tank 91 is NaO
It consists of an alkali neutralizing agent such as H, CaO, Ca ₂ (OH) ₃ .

Reference numeral 103 denotes a line for draining the water filtered by the filter 93 to a drain tank 88; 104, a liquid communication line for communicating the venturi scrubber 14 with the bottom of the neutralization tower 15; On-off valves 107 connected to the line 50 and the return line 51, respectively.
Denotes an air introduction hole provided in the package 10, and 108 denotes a viewing window provided in the incinerator 12.

Next, the operation of the present invention will be described.

First, at the start of operation, the pushing fan 27 and the inducing fan 67 are operated to perform air purging in each system.

Now, the pushing fan 27 and the air supply line 2
8 and natural gas from the fuel gas line 30 are supplied to the pilot burner 26 and burned.

The liquid scintillator waste liquid injected into the waste liquid tank 11 from the injection port 17 passes through a waste liquid supply line 20 from a waste liquid pump 18, is flow-regulated by a flow control valve 23, is injected from a fixed quantity burner 21, and is incinerated It is heated and burned on a pan 34 at the bottom of the 12.

The liquid scintillator waste liquid is mostly toluene or methanol as described above, is injected from the fixed quantity burner 21, and after ignition, is completely burned by sending only air from the pilot burner 26.

The temperature in the incinerator 12 is controlled by spraying water containing a neutralizing agent from a spray nozzle 35, and is maintained at 800 ° C. or higher, actually 850 ° C. with a margin, and the combustion gas Stays in the incinerator 12 for about 2 seconds and is supplied from the outlet 38 to the subsequent cooler 13.

The combustion gas temperature of the incinerator 12 is measured by a thermometer 40.
The flow rate control valves 32, 33, 37, and 98 are controlled such that the temperature is 850 ° C. as described above.

That is, when the temperature is high, the opening of the flow control valve 98 of the spray nozzle 35 is increased, and when the temperature is low, the flow control valve 3 of the fuel gas supply line 30 is increased.
2 and the opening degree of the flow control valve 33 of the air supply line 28 is increased to control the amount of combustion by the pilot burner 26 to increase.

The combustion gas generated in the incinerator 12 is supplied to the cooler 1
3 where it is cooled to 200 ° C. At this time, the generation of dioxin can be suppressed by completely burning in the furnace, and the dioxin can be hardly generated by rapidly cooling the vicinity of the recombination temperature range of 300 ° C. and lowering it to 200 ° C. in the cooler 13. it can.

In the cooler 13, the pressure is set to, for example, 5 to 5 so that the dew point is not reached even when the combustion gas is lowered to 200 ° C.
At 8 kg / cm ² , corrosion is prevented by preventing condensation on the heat transfer tube 43, and solids such as ash and dust contained in the combustion gas are collected in the dust box 55.

The combustion gas cooled by the cooler 13 is blown into water from a venturi nozzle 58 of the venturi scrubber 14, cooled to 100 ° C. or lower, and further supplied to the neutralization tower 15 through a connecting pipe 60.

In the neutralization tower 15, Na
When a neutralizing agent such as OH is sprayed and gas-liquid contacts the packed layer 63, HCl and SOx in the gas are absorbed and removed, and the mist is removed by the demister 64.
And cooled by the induction fan 67 to the auxiliary cooler 16.
And is exhausted through an exhaust line 70.

During this waste liquid combustion operation, a gas is sampled from the radiation isotope measuring port 110 connected to the exhaust line 70, and it is confirmed whether or not the gas contains a radioisotope. Further, when an earthquake or the like occurs, it is detected by an earthquake sensor (not shown) attached to the package 10,
The on-off valve 22 of the liquid scintillator waste liquid supply line 20 is closed, and the waste liquid from the waste liquid pump 18 is transferred to the bypass line 24.
To return to the waste liquid tank 11 so as not to perform combustion.

After the waste liquid combustion, if the neutralization liquid concentration in the neutralization tower 15 is high, the operation of the incinerator 12 is continued, and the neutralization liquid is sprayed from the spray nozzle 35, dried in the incinerator 12, and solidified. The dust is collected in the dust box 55, and the operation is stopped when the concentration decreases.

FIG. 2 shows another embodiment of the present invention.

The embodiment of FIG. 2 is basically the same as the embodiment of FIG. 1, but instead of burning the fuel gas from the fuel gas supply line 30 with the pilot burner 26, the air is supplied to the air supply line 28. A preheater 112 is connected, an electric heater is provided in the air preheater 112, and a power is supplied to the electric heater from a power source 113 to heat the air and the burner 21 is heated.
And burns the liquid scintillator waste liquid while heating it with preheated air.

In this embodiment, the temperature of the incinerator 12 is controlled by controlling the opening of the flow control valve 33 connected to the air supply line 28 and the amount of electricity supplied to the air preheater 112. Can be maintained at 850 ° C. to burn the waste liquid.

FIG. 3 shows still another embodiment of the present invention.

In this embodiment, the combustion gas from the outlet 38 of the incinerator 12 is supplied to the venturi nozzle 58 of the venturi scrubber 14 directly from the line 39 without using the cooler 13 described in FIG. The above combustion gas is cooled to 100 ° C. or less.

At this time, the water in the scrubber 57 is supplied to the line 9
0 through a filter 93 and a pump 94 through a neutralizing agent line 95 through a flow control valve 101 to a venturi nozzle 58 to mix the neutralizing liquid together with the combustion gas into the scrubber 5.
7 to be cooled while containing HC in the combustion gas.
l and SOx are neutralized with a neutralizing agent.

The neutralizing agent is connected to a neutralizing agent tank 120 by connecting an introducing line 121 for introducing a liquid from the neutralizing agent line 95 and a mixing line 122 to the neutralizing agent tank 120.
The valve 123 is connected to the neutralizing agent line 95 between them, and the valves 124 and 125 are connected to both lines 121 and 122, and the opening degree of each of the valves 123, 124 and 125 is adjusted. The concentration of the neutralizing agent is adjusted by adjusting the inflow amount of the neutralizing agent.

At this time, the pH meter mounting seat 126 is connected to the neutralizing agent line 95, and the pH meter mounting seat 126 is connected to the pH meter mounting seat 126.
A meter is connected to detect the pH value (concentration) of the neutralizing agent, and the valves 123, 124, and 125 are adjusted so that the concentration becomes appropriate.
Adjust the opening of.

The gas from the neutralization tower 15 is supplied to a line 66
Then, the air is introduced into the sub-cooler 16 via a sub-cooler 16, and an exhaust fan 70 is connected to an exhaust line 70 of the sub-cooler 16 to exhaust air.

At this time, the motor 68 of the induction fan 67 is driven by the inverter device 69, and
The pressure of the combustion gas discharged to the exhaust gas is detected by the pressure gauge 29, and the amount of exhaust air from the induction fan 67 is controlled by the inverter device 69 so that the pressure becomes negative.

In the embodiment shown in FIG.
In the example of FIG. 3, the pressure is set high so that the combustion gas does not become lower than the dew point even when the combustion gas is cooled. However, in the embodiment of FIG. Even if a leak occurs, the gas containing the radioactive isotope can be maintained by maintaining the inside of the package 10 at a negative pressure.
Leakage to the outside can be reliably prevented.

In the embodiment shown in FIG. 3, dust and the like contained in the combustion gas are mixed into the water of the venturi scrubber 14 and collected by the filter 93, but the dust in the combustion gas is reduced as much as possible. Therefore, there is no problem even if it is directly collected by the venturi scrubber 14.

FIG. 4 is a modification of FIG. 3, and instead of using the combustion gas line 30 and the pilot burner 26,
The air is preheated by using the air preheater 112 described with reference to FIG. 2, and the other configuration is the same as that of FIG.

Although FIGS. 1 to 4 show the case where the neutralization tower 15 is used, harmful gases (for example, SOx) which require a relatively long time to complete the neutralization reaction are shown.
) Is not contained in the combustion gas, or if the amount is extremely small and is sufficiently neutralized and removed and rendered harmless by merely passing through the venturi scrubber 14, the neutralization tower becomes unnecessary. Neutralization tower 1 from each embodiment of FIGS.
5 can be removed.

[0065]

In summary, according to the present invention, the liquid scintillator waste liquid can be safely incinerated in a package.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing still another embodiment of the present invention.

FIG. 4 is a diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Package 11 Waste liquid tank 12 Incinerator 13 Cooler 14 Venturi scrubber 15 Neutralization tower 55 Dust box

Claims (4)

[Claims] 1. A waste liquid tank containing a liquid scintillator waste liquid, an incinerator in which the liquid scintillator waste liquid in the waste liquid tank is injected and burned at 800 ° C. or more with supplied combustion air, and generated in a combustion furnace. A cooler having a dust box for cooling the combustion gas cooled to 200 ° C. or less and collecting dust in the combustion gas, a venturi scrubber for cooling the combustion gas cooled by the cooler to 100 ° C. or less, and exhausting the waste liquid, A liquid scintillator waste liquid incinerator, comprising: an incinerator, a cooler, and a package containing a venturi scrubber. 2. A waste liquid tank containing a liquid scintillator waste liquid, an incinerator in which the liquid scintillator waste liquid in the waste liquid tank is injected and burned at 800 ° C. or more with supplied combustion air, and generated in a combustion furnace. Cooler having a dust box for cooling the combustion gas cooled to 200 ° C. or less and collecting dust in the combustion gas, a venturi scrubber for cooling the combustion gas cooled by the cooler to 100 ° C. or less, and cooling from the venturi scrubber A neutralizing tower for contacting the gas with a neutralizing agent to remove harmful substances such as HCl and SOx and exhausting the gas; and a package containing the waste liquid tank, incinerator, cooler, venturi scrubber and neutralizing tower. A liquid scintillator waste liquid incinerator characterized by comprising: 3. A waste liquid tank containing a liquid scintillator waste liquid, an incinerator in which the liquid scintillator waste liquid in the waste liquid tank is injected, and burns at 800 ° C. or more with supplied combustion air; A liquid scintillator comprising: a venturi scrubber for blowing the combustion gas into a water scrubber together with a neutralizing agent to cool the exhaust gas to 100 ° C. or less and exhausting the exhaust gas; and a package containing the waste liquid tank, the incinerator, and the venturi scrubber. Waste liquid incinerator. 4. A waste liquid tank containing a liquid scintillator waste liquid, an incinerator in which the liquid scintillator waste liquid in the waste liquid tank is injected and burned at 800 ° C. or more with supplied combustion air, and generated in a combustion furnace. A venturi scrubber which blows the burned gas together with a neutralizing agent into a water scrubber to cool it to 100 ° C. or lower and exhausts the gas; and further cools the gas from the venturi scrubber to contact the neutralizing agent with HCl and SOx in the gas. 1. A liquid scintillator waste liquid incineration apparatus comprising: a neutralization tower for removing and exhausting harmful substances described above, and a package containing the waste liquid tank, the incinerator, the venturi scrubber, and the neutralization tower.