JP2001178843A - Device for decomposing organic halide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for decomposing organic halides which can prevent the system of the device from being overheated. SOLUTION: In the device for decomposing organic halides including a reaction tube 15 for decomposing organic halides and a waste gas treatment tank 41 for neutralizing an acidic gas (decomposition product) decomposed at the tube 15, a treating liquid drawn up by a slurry pump 53a is circulated between the slurry pump 53a to draw up the treating liquid stored in the tank 41 and the tank 41, while a cooling heat exchanbger 53c to cool the treating liquid, an air-cooling fan 53b to send air to the exchanger 53c, a thermocouple (temperature sensing means) 54 to detect the temperature of the treating liquid, and a control means (control device) to control the number of revolution of the fan 53b by means of detection outputs of the means 54 are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic halogen compound decomposing apparatus for decomposing organic halogen compounds such as chlorofluorocarbons to render them harmless.

[0002]

2. Description of the Related Art Organic halogen compounds such as chlorofluorocarbon (so-called chlorofluorocarbon) and trichloromethane containing fluorine, chlorine, bromine and the like in a molecule are widely used in a wide range of applications such as refrigerants, solvents and fire extinguishers. The importance in the industrial field is extremely high. However, these compounds have high volatility, and if released untreated into the atmosphere, soil, water, etc., they may produce carcinogens, destroy the ozone layer, etc.
Since it may adversely affect the environment, it is necessary to perform detoxification treatment from the viewpoint of environmental protection.

[0003] Conventionally, methods for treating organic halogen compounds have been reported which mainly utilize a thermal decomposition reaction at a high temperature, and this treatment method is further roughly classified into an incineration method and a plasma method. In the incineration method, the organic halogen compound is incinerated together with ordinary waste such as resin.On the other hand, in the plasma method, the organic halogen compound is reacted with water vapor in plasma to produce carbon dioxide, hydrogen chloride, and fluorine. It decomposes into hydrogen.

[0004] Further, as for the latter method of controlling the decomposition of an organic halogen compound according to the plasma method, a method of generating plasma using microwaves has recently been developed. The decomposition apparatus used in this decomposition method includes an exhaust gas treatment tank containing an alkaline solution, a reaction tube disposed with the open lower end immersed in the alkaline solution, and a vertically extending above the reaction tube. A cylindrical waveguide, a discharge tube disposed inside the cylindrical waveguide and penetrating the lower end thereof and communicating with the reaction tube, and extending horizontally and connected to the cylindrical waveguide near one end thereof. And a microwave transmitter mounted on the other end of the rectangular waveguide.

[0005] In this decomposition apparatus, while the Freon gas and the water vapor are supplied to the discharge tube, the microwave transmitted from the microwave transmitter is transmitted to the cylindrical waveguide through the rectangular waveguide. Then, a discharge is caused by the microwave electric field formed inside the cylindrical waveguide, and the fluorocarbon gas is decomposed by the thermal plasma in the reaction tube. On the other hand, acid gas (hydrogen fluoride and hydrogen chloride) is generated by this decomposition reaction.
This gas is guided into the alkaline liquid by the blowing pipe and neutralized, and the remaining gas including carbon dioxide gas is discharged from the exhaust duct.

[0006]

The above neutralization reaction is an exothermic reaction. For example, when 1 kg / h of chlorofluorocarbon is treated, 3 kW of heat is generated. For this reason, there is a problem that if the decomposition of the chlorofluorocarbon gas is continued, the system such as the alkaline liquid and the exhaust gas treatment tank is overheated.

[0007] In view of the above circumstances, an object of the present invention is to provide an organic halogen compound decomposer capable of suppressing overheating of an apparatus system.

[0008]

Means for Solving the Problems In order to solve the above problems, the present invention employs the following constitution. Claim 1
The apparatus for decomposing an organic halogen compound described in the above, in an apparatus for decomposing an organic halogen compound comprising a reaction tube for decomposing an organic halogen compound and an exhaust gas treatment tank for neutralizing decomposition products decomposed in the reaction tube, A cooling heat exchanger that circulates the processing liquid sucked up by the pump between the pump that sucks up the processing liquid stored in the processing tank and the exhaust gas processing tank, and cools the processing liquid; An air-cooling fan that blows air to the exchanger, a temperature detection unit that detects the temperature of the processing liquid, and a control unit that controls the rotation speed of the air-cooling fan based on a detection output of the temperature detection unit. .

In this organic halogen compound decomposing apparatus, the processing liquid is introduced into a cooling heat exchanger and cooled by an air cooling fan. Therefore, overheating of the device system is prevented. In addition to the air-cooling type, a water-cooling type such as a cooling tower is also conceivable. Further, the air-cooling type can easily control the temperature by controlling the air-cooling fan as described above, and can quickly cool the exhaust gas treatment tank against a rise in temperature.

According to a second aspect of the present invention, in the organic halogen compound decomposing apparatus according to the first aspect, foreign matter removing means for removing foreign matter from the processing liquid sucked up by the pump is provided. The heat exchanger for use is a fin-tube heat exchanger.

[0011] Since a slurry, which is a neutralization product, is mixed in the treatment liquid, when the fin-tube type is used as the cooling heat exchanger, the slurry may cause clogging of the cooling heat exchanger. is there. Therefore, a foreign matter removing means is provided to prevent clogging of the cooling heat exchanger.

According to a third aspect of the present invention, there is provided the organic halogen compound decomposing apparatus according to the first or second aspect, wherein the three-way valve is provided in the middle of the circulation path of the processing liquid. And a drainage treatment device for selectively supplying the treatment liquid with the exhaust gas treatment tank and the wastewater treatment device.

In this organic halogen compound decomposing apparatus, the cooling system for cooling the processing liquid and the drainage processing system share a pump, so that the same pump can be operated by switching the three-way valve. Instead of circulating the treatment liquid to the exhaust gas treatment tank, the treatment liquid can be sent to a waste liquid treatment device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an organic halogen compound decomposing apparatus according to the present invention will be described with reference to FIGS. In FIG. 1, a rectangular waveguide 1 extending in a horizontal direction is provided with a microwave transmitter 2 for transmitting a microwave having a frequency of 2.45 GHz at a starting end thereof, and the microwave is transmitted from a starting end to a terminating end. Transmit.

As shown in FIG. 1, the rectangular waveguide 1 prevents the reflected wave from affecting the transmitting side by absorbing the microwave reflected at the terminal end and returning to the starting end. An isolator 3 and a tuner 6 for moving a plurality of wave adjustment members 4 in and out of the discharge tube 5 so as to adjust the amount of wave mismatch of the wave and converge the wave to the discharge tube 5 are provided.

Here, the operation of generating microwaves will be described. The microwave transmitter 2 is placed at one end of a waveguide having a rectangular cross section, and drives a magnetron to emit an electromagnetic wave having a predetermined frequency. The characteristics of this electromagnetic wave propagation phenomenon can be grasped by solving Maxwell's wave equation relating to the electromagnetic wave. As a result, the electromagnetic wave propagates as an electromagnetic wave TE wave having no electric field component in the propagation direction.

[0017] indicated by arrows the direction examples of the first-order component TE ₁₀ alternates the propagation direction of the rectangular waveguide of Figure 2. The annular cavity of the double-cylindrical waveguide formed of a double-cylindrical conductor at the other end of the rectangular waveguide 1 has conductors 9 for electromagnetic waves propagating in the waveguide 1 and electromagnetic waves reflected at the tube end. , A TM wave having an electric field component in the traveling direction is generated in the annular cavity. The TM ₁₀ wave is the primary component are also shown by the arrows in the annular cavity of FIG. The fine adjustment caused by the second or higher harmonics related to the propagation of the electromagnetic wave is adjusted by the tuner 6. The isolator 3 prevents the microwave transmitter 2 from causing fundamental damage.

As shown in FIG. 2, the discharge tube 5 is composed of an inner tube 11 and an outer tube 12, and is disposed so as to be coaxial with the central axis of the cylindrical waveguide 7. The cylindrical waveguide 7 is composed of an outer conductor 8 and an inner conductor 9 having a smaller diameter than the outer conductor 8, and extends in the vertical direction near the terminal end of the rectangular waveguide 1 while communicating with the rectangular waveguide 1. Connected. The inner conductor 9 surrounds the quartz discharge tube 5 while being fixed to the upper part of the rectangular waveguide 1 and surrounds the outer conductor 8.
, And the extended portion is used as a probe antenna 9a. An ignition electrode 14 connected to an ignition transformer 13 is inserted into the inner tube 11 of the discharge tube 5.

Further, the tip (lower end) of the inner tube 11 is disposed at a predetermined distance inward from the tip of the probe antenna 9a.

On the other hand, the tip of the outer tube 12 penetrates through the end plate 8A of the outer conductor 8 and communicates with the copper reaction tube 15;
The proximal end (upper end) of the outer tube 12 is attached with a gap between the outer tube 12 and the inner conductor 9. An optical sensor 17 is provided between the end plate 8A of the outer conductor 8 and the reaction tube 15 toward the exposed outer cylinder 12. The optical sensor 17
The state of plasma generation is monitored by detecting the luminous intensity.

In the gap between the inner conductor 9 and the proximal end of the outer cylinder 12, a gas supply pipe 16 is tangentially arranged at the inlet side of the annular passage formed by the outer pipe 12 and the inner pipe 11. Are inserted along. Argon gas (rare gas), Freon gas (organic halogen compound), air, and water vapor are supplied to the annular passage of the discharge tube 5 via the gas supply tube 16. These argon gas, Freon gas and air are
By the opening and closing operations of the solenoid valves 19a, 19b and 19c shown in FIG.

Argon gas is supplied to facilitate ignition prior to generation of plasma, and is stored in an argon cylinder 21. Needless to say, a rare gas such as helium or neon can be used in addition to the argon gas. A pressure regulator 22 and a pressure switch 23 are provided between the argon cylinder 21 and the solenoid valve 19a.
Is provided.

The air is supplied from the air compressor 24 in order to remove moisture remaining in the system to enhance the stability of ignition and to discharge gas remaining in the system. , Nitrogen gas, argon gas and the like are used. The water vapor is necessary for decomposing the chlorofluorocarbon gas, and is generated by sending water in the water storage tank 26 to the heater 18 by the plunger pump 25. This water storage tank 2
6 is provided with a level switch 27 for detecting a change in water level.

The chlorofluorocarbon gas is stored in liquid in a collected chlorofluorocarbon cylinder 28, and the collected chlorofluorocarbon cylinder 28 and the electromagnetic valve 1
9b, the squeezing device 31, the mist separator 3
2, and a pressure switch 33 are provided. The throttle device 31 is provided for quantifying the flow, and is constituted by, for example, a combination of a capillary tube and an orifice.

The mist separator 32 is for removing oil (lubricating oil) and water contained in the CFC gas, and is of a collision type or a centrifugal type. The heater 18 is intended not only to generate water vapor to be reacted with the chlorofluorocarbon gas, but also to prevent the problem that the vapor is cooled down to the chlorofluorocarbon gas and re-condensed in the apparatus by heating the fluorocarbon gas or the like in advance. A heating method such as an electric type or a steam type is adopted.

In the heater 18, two parallel flow paths 3 are provided.
4a and 34b are formed. Freon gas, argon gas, and air are introduced into one flow path 34a, and water is introduced from the water storage tank 26 into the other flow path 34b to generate steam. Channel 3 on the side that generates this water vapor
4b is filled with a resistor 35 that gives resistance to water vapor moving in the flow path 34b, so that the water vapor cannot flow smoothly in the flow path.

As the resistor 35, an inorganic or organic granular, fibrous, porous material or a molded product thereof is employed. From the viewpoint of preventing deterioration at high temperatures, SiO ₂ , Al, and the like are used. ₂ O ₃ , TiO ₂ , MgO, ZrO ₂
And inorganic materials such as oxides, carbides, nitrides and the like. A thermocouple 36 is provided near the outlet of the heater 18.

However, the fluorocarbon gas and the steam that have passed through the heater 18 are mixed in the mixer 37 and then supplied to the discharge tube 5 through the gas supply tube 16.

The reaction tube 15 is provided with a blow-in tube 45 via an exchange joint 44 as shown in FIG. The exchange joint 44 is detachably connected between the reaction tube 15 and the blow-in tube 45. The blow-in tube 45 is made of a SUS material, and is provided in the exhaust gas treatment tank 41 as shown in FIG. It is housed and folded on the way.

The exhaust gas treatment tank 41 is provided to neutralize and detoxify acidic gases (hydrogen fluoride and hydrogen chloride) generated as a result of decomposing the chlorofluorocarbon gas and blown out from the blowing pipe 45. It contains an alkaline suspension of water and calcium hydroxide (hereinafter simply referred to as an alkaline solution). For example,
When the Freon gas to be decomposed is Freon R12 for refrigerant collected from a waste refrigerator, the acid gas as a decomposed product generated by the decomposition reaction shown in Formula 1 is detoxified by the neutralization reaction shown in Formula 2.

(Formula 1) CCl ₂ F ₂ + 2H ₂ O → 2HCl + 2HF + CO ₂ (Formula 2) 2HCl + Ca (OH) ₂ → CaCl ₂ + 2H ₂ O 2HF + Ca (OH) ₂ → CaF ₂ + 2H ₂ O

Since the neutralized products (calcium chloride and calcium fluoride) produced by the neutralization reaction of the formula (2) have low solubility, some of them are dissolved in an alkaline solution, but most of them are present as a slurry. Further, the carbon dioxide generated by the decomposition reaction of the formula 1 and the acid gas reduced to a very small amount equal to or less than the emission reference value by the neutralization reaction of the formula 2 are connected to the exhaust duct 42 connected above the exhaust gas treatment tank 41. Is discharged out of the system by the blower 43.

From the tip (lower end) of the blowing pipe 45, the gas produced by the decomposition reaction of the formula 1 is released as bubbles into the alkaline solution. Since the larger the contact area with the air and the longer the time until the air bubbles reach the liquid surface, the more the air is promoted, the air bubbles in the exhaust gas treatment tank 41 that accelerate the neutralization reaction of Formula 2 by finely dividing the air bubbles A dividing means 52 is provided.

The bubble dividing means 52 has six blades 52b driven to rotate by a motor 52a. The bubble separating means 52 is arranged such that the blade 52b is located above the tip of the blowing pipe 45, and the bubbles floating from the tip of the blowing pipe 45 hit the blade 52b rotating at about 300 rpm and have a diameter of about 3 mm to 5 mm. Finely divided into bubbles. The bubble separating means 52 also plays a role of forming a suspension of water and water-insoluble calcium hydroxide by stirring the calcium hydroxide powder charged into the exhaust gas treatment tank 41. Bubble separating means 52
Keeps the operating state from the start of the operation of the plasma decomposition apparatus to the end of the operation. Except during the operation of the disassembly unit, it will be stopped.

Further, the exhaust gas treatment tank 41 has a pH value
A sensor 55 is provided. The pH value of the alkaline solution is
A control device (control means) is always provided via the pH sensor 55.
61 (see FIG. 3), for example, when the pH value becomes 9 (11 to 12 at the start of operation), the controller 6
The alarm means is actuated by the command from 1 and the disassembling operation is stopped. Any means can be used as the alarm means, as long as it can draw attention to the surroundings,
For example, means such as blinking a lamp or sounding a horn is employed.

The exhaust gas treatment tank 41 is provided with a cooler 53 for cooling the alkaline liquid (treatment liquid) because the neutralization reaction of the formula 2 is an exothermic reaction. In the following, the treatment liquid refers to an alkaline liquid or a liquid after the alkaline liquid is neutralized, and includes a slurry. The cooler 53 includes a slurry pump (pump) 53a for sucking up the processing liquid, a strainer (foreign matter removing means) 53d for removing foreign matter from the sucked up processing liquid, and a slurry pump 5
The processing liquid sucked up by 3a is discharged into an exhaust gas processing tank 4
A cooling heat exchanger 53c circulating between the cooling water exchanger 1 and an air cooling fan 53b for blowing air to the cooling heat exchanger 53c; and a thermocouple (temperature detecting means) 54 for detecting the temperature of the processing liquid. The control device 61 (see FIG. 3) receives the detection output of the thermocouple 54 and controls the air cooling fan 53b and the slurry pump 53a based on the detection output.

A three-way valve 56 is interposed in the treatment liquid circulation path, and a settling tank (drainage treatment device) 62 from which the treatment liquid branches off from the three-way valve 56 is provided. Three-way valve 56
By switching the processing liquid, the processing liquid
1 and the sedimentation tank 62.
The flow path of the processing liquid is made of heat-resistant vinyl chloride, and a general Y strainer can be used as the strainer 53d. As the cooling heat exchanger 53c, a fin-tube heat exchanger is used, and a heat exchanger used for an air conditioner or the like can be used.

A stirrer 62a is provided inside the settling tank 62, and after a coagulant is added to the treatment liquid to cause coagulation, the liquid is separated into solid and liquid by a dehydrating basket 63 provided below the settling tank 62. It has become.

A procedure for decomposing chlorofluorocarbon in the organic halogen compound decomposing apparatus having the above-described structure will be described. The opening and closing operation of the solenoid valve and the ignition operation of the ignition transformer 13 are controlled by the control device 61 as shown in FIG. As is clear from this figure, in this disassembly apparatus, 8
Decomposition of the chlorofluorocarbon gas is performed by batch processing with one cycle of time.

That is, before supplying the chlorofluorocarbon gas and water vapor, first, the operation of the decomposition apparatus is started by supplying the heated air for the purpose of removing the moisture remaining in the system for a predetermined time (3 minutes). I do. At this time, the operation of the bubble dividing means 52 also starts at the same time. After the air supply is stopped, the supply of argon gas is started for the purpose of improving ignition stability. Then, during the supply of the argon gas, the microwave is transmitted to ignite the ignition transformer 13, and the steam and the chlorofluorocarbon gas are supplied to decompose the chlorofluorocarbon. Thereafter, the supply of the argon gas is stopped. The moisture may be removed by drying the air.

After the decomposition operation is stopped, air as scavenging gas is supplied for a predetermined time (5 hours) for the purpose of ensuring safety.
Min) and purge residual acid gases. The purged acid gas is neutralized in the exhaust gas treatment tank 41. At this time, by keeping the bubble separating means 52 in the operating state, the processing liquid is agitated and neutralization is promoted. afterwards,
The purging is stopped and the operation of the decomposition apparatus is terminated. At the same time, the motor 52a is stopped, and the operation of the bubble dividing means 52 is stopped. Since the stirring in the exhaust gas treatment tank 41 is stopped by the stop of the bubble dividing means 52, the slurry precipitates in the tank 41.

In the above steps, the supply of the argon gas and the supply of the chlorofluorocarbon gas may overlap with each other. However, the time between the start of the supply of the chlorofluorocarbon gas and the stop of the supply of the argon gas may be very small. The reason is,
This is because, as long as the ignition state is stabilized, it is not necessary to continuously supply the argon gas, and it is necessary to keep the argon consumption low from the viewpoint of cost reduction. In particular, compared to other plasmas, for example, high frequency induction plasma, plasma by microwave is highly stable,
Even if the supply of the argon gas is stopped, there is almost no effect on the conversion of the chlorofluorocarbon gas into plasma.

The control device 61 includes the pressure switch 2
By receiving signals from various sensors such as 3, 33, thermocouples 36 and 54, the level switch 27, and the optical sensor 17, the supply pressure of argon gas and Freon gas to the heater 18, the liquid level in the water storage tank 26, the plasma Generation state,
The temperature in the exhaust gas treatment tank 41 is constantly monitored, and if these temperatures deviate from the prescribed values, the operation is stopped because there is a possibility that the operation is not performed normally or efficiently. However, when the temperature in the exhaust gas treatment tank 41 is high, the alkali liquid is cooled by the cooler 53 as described later. After the operation is stopped, air is supplied as described above to ensure safety, and the residual gas in the device is scavenged.

Next, the chlorofluorocarbon decomposition step shown in FIG. 5 will be described in more detail. First, the solenoid valve 19a,
By closing the solenoid valve 19b and opening the solenoid valve 19c, the air from the air compressor 24 is supplied to the discharge tube 5 via the gas supply tube 16 for three minutes. This air is supplied to the heater 18.
Is heated to 100 to 180 ° C. For this reason, residual moisture in the device is reliably removed,
The ignition stability is improved.

Next, the solenoid valve 19c is closed and the solenoid valve 19a is opened, and argon gas is supplied to the discharge tube 5. At this time, since the argon gas is supplied from the tangential direction of the outer tube 12 and flows down spirally, stagnation is formed near the tip of the inner tube 11 and plasma is easily held.

The gas supply amount at this time is 4 to 40.
l / min, desirably 15 l / min or more. In this setting range, the stagnation is effectively formed, the plasma is more easily held, and the discharge tube 5 is hardly affected by the thermal influence of the plasma, so that melting deformation and breakage thereof are effectively prevented. Become.

Then, a microwave is transmitted from the microwave transmitter 2 at a constant interval from the start of the supply of the argon gas. The microwave is transmitted to the rear end side by the rectangular waveguide 1 and further transmitted to the cylindrical waveguide 7.

At this time, as the electric field in the cylindrical waveguide 7, a TM ₀₁ mode having a large electric field intensity is formed, and the electric field mode in the rectangular waveguide 1 and the electric field mode in the cylindrical waveguide 1 are formed by the inner conductor 9. The electric field inside the cylindrical waveguide 7 is stable because the electric field mode inside the cylindrical waveguide 7 is coupled. As a matter of course, the magnetic field is generated in a direction orthogonal to the electrolysis. The gas introduced into the discharge tube 5 is heated to a plasma state by the oscillating electromagnetic field.

Next, a high voltage is applied to the ignition electrode 14 connected to the ignition transformer 13 to generate a spark discharge between the ignition electrode 14 and the inner conductor 9 to ignite. At this time, the interior of the discharge tube 5 is easily ignited because the moisture is removed by air and an easily ignited argon gas is supplied in advance. Next, the water storage tank 2 is moved by the plunger pump 25.
Water is sucked from the heater 6, the water is sucked through the heater 18, and the generated steam is supplied to the discharge tube 5.

After the supply of water vapor is started, the supply of chlorofluorocarbon gas is started as described later. The reason for supplying the water vapor first is as follows. In the method for controlling the operation of the organic halogen compound decomposing apparatus according to the present embodiment, a fluorocarbon gas and water vapor are supplied at a fixed molar ratio to decompose and react to generate an acidic gas. This is because if only the fluorocarbon gas is turned into plasma, an unexpected harmful halogen compound is generated due to recombination of the dissociated atoms, so that the detoxification process cannot be performed. Therefore, by supplying steam to the discharge tube 5 and then supplying the chlorofluorocarbon gas as described above and leaving the water vapor present at the time of chlorofluorocarbon decomposition, fluorocarbon can be safely decomposed.

The steam cannot flow smoothly in the flow path due to the resistor 35 filled in the heater 18, and a constant amount of steam always stays in the heater 18. . For this reason, scattering due to pulsation or bumping is prevented, the outflow amount of steam is stabilized, and fluctuations in the flow rate on the upstream side of the mixer 37 can be effectively suppressed. Therefore, the plasma can be stabilized without causing the disappearance of the plasma, and the processing capability can be improved.

Next, the solenoid valve 19b is opened, and CFC gas is supplied to the discharge tube 5. At this time, the chlorofluorocarbon gas flowing out of the collected chlorofluorocarbon cylinder 28 is supplied to the mist separator 3.
2 to remove oil and moisture.
For this reason, the generation of dirt on pipes and by-products due to lubricating oil in Freon gas is suppressed, and efficient and stable supply of Freon gas and the like can be performed. Does not occur. Therefore, it is possible to stabilize the plasma and improve the processing capability.

The steam, argon gas, and CFC gas flowing into the mixer 37 through the heater 18 flow out in a uniformly mixed state, and are supplied to the discharge tube 5. For this reason, the decomposition reaction of Formula 1 is sufficiently performed, and the generation of by-products such as chlorine gas and carbon monoxide can be suppressed.

When the CFC gas supplied to the discharge tube 5 is irradiated with the microwave, the discharge tube 5
High electron energy and temperature of 2,000K ~
Thermal plasma increased to 6,000 K is generated. At this time, not only the chlorofluorocarbon gas and water vapor but also the discharge tube 5
Since the argon gas is supplied at the same time, the plasma does not disappear.

Further, since the distal end of the inner tube 11 is disposed at a predetermined distance inward from the distal end of the probe antenna 9a, the thermal influence of the generated plasma can be avoided.
Melt breakage of the inner tube 11 is prevented. As a result, a stable decomposition operation can be performed without remarkable deformation of the plasma shape.

However, the generation of thermal plasma causes the fluorocarbon gas to be easily dissociated into chlorine atoms, fluorine atoms, and hydrogen atoms, so that it is easily decomposed by reacting with water vapor as shown in equation 1. When the plasma is stabilized, the electromagnetic valve 19a is closed to stop the supply of the argon gas. Therefore, when the fluorocarbon gas is decomposed for a long time, the supply of argon is unnecessary, and the consumption of argon can be kept low. The gas produced by the decomposition reaction passes through the exchange joint 44 and the blowing pipe 45,
It is released into the alkaline liquid in 1.

Thus, the product gas released into the alkaline solution through the blowing pipe 45 is rendered harmless by the neutralization reaction of the formula (2). Since this neutralization reaction is an exothermic reaction, the temperature of the alkaline solution is cooled by the cooler 53. That is, the output of the thermocouple 54 is input to the control device 61, and the control device 61 appropriately drives the slurry pump 53a and the air-cooling fan 53b with an upper limit of about 60 degrees so that the temperature of the alkaline solution does not increase too much. I do. Since the slurry pump 53a and the fan 53b can be stopped until the temperature of the processing liquid rises to about 60 degrees, power consumption is suppressed.

The generated gas released as bubbles from the tip of the blowing pipe 45 is supplied to the blade 52 of the bubble dividing means 52.
Since it is finely divided at d, the contact area with the alkaline liquid increases and the time to reach the liquid surface increases, thereby promoting the neutralization reaction. As a result, the amount of acidic gas exceeding the reference value is not discharged out of the system due to insufficient neutralization.

Of the product gas detoxified by the neutralization reaction, gas is exhausted from the exhaust duct 42, and the other gas remains as a slurry in the alkaline liquid. After disassembly operation is stopped,
After stopping the bubble separating means 52, the three-way valve 56 is switched, and the processing liquid is pumped up by the slurry pump 53a and transferred to the settling tank 62. While the treatment liquid transferred to the settling tank 62 is stirred by the stirrer 62a, the coagulant is uniformly added thereto.
After the 2a is stopped and settled, solid-liquid separation is performed in the dehydrating basket 63, the liquid component is subjected to wastewater treatment, and the solid component is discarded. After the disassembly operation is stopped, the air compressor 24
Is driven to scavenge the acid gas remaining in the apparatus, so that the safety is also improved.

As described above, in the decomposition apparatus, the processing liquid is introduced into the cooling heat exchanger 53c,
Since cooling is performed by 3b, overheating of the device system is prevented. Also, by providing the strainer 53d,
Clogging of the fin-tube cooling heat exchanger 53c is prevented. Further, the provision of the three-way valve 56 allows the processing liquid to be sent to the settling tank 62. Thereby, the processing liquid can be circulated to the exhaust gas processing tank 41 by the slurry pump 53a,
It can also be sent to the settling tank 62. Further, since the slurry pump 53a and the fan 53b can be stopped until the temperature of the processing liquid rises to about 60 degrees, power consumption is suppressed. The adoption of the air cooling system allows the rotating fan 5 to rotate based on the detection output of the thermocouple 54.
By rotating 3b, the temperature of the processing liquid can be rapidly cooled.

The apparatus for decomposing an organic halogen compound according to the present invention is not limited to the above embodiment, but includes the following embodiments. (1) Although the three-way valve 56 is provided downstream of the cooling heat exchanger 53c, it may be provided downstream of the slurry pump 53a and upstream of the cooling heat exchanger 53c. (2) As in the case of the exhaust gas treatment tank 41 'shown in FIG. 5, the material may be made of metal such as SUS and the heat radiation fins 41a may be formed on the outer peripheral wall to prevent the temperature of the treatment liquid from rising. In this case, the cooler 53 may not be provided, or may be used as an auxiliary. Further, an air cooling fan that blows air to such an exhaust gas treatment tank 41 ′ may be provided. (3) Instead of pH control of alkaline solution, as a means to avoid the discharge of acidic gas outside the system due to insufficient neutralization treatment,
The motor current value may be managed. That is,
When the motor speed decreases or stops, the air bubbles discharged from the blowing pipe 45 may not be sufficiently divided, and the neutralization reaction may not be sufficiently performed. Therefore, if the abnormality of the motor rotation is detected based on the motor current value and the operation of the decomposing device is stopped by a command from the control device 61, the discharge of the acid gas out of the system can be prevented beforehand. (4) Instead of arranging the tip of the ignition electrode 14 inside the discharge tube 5, it may be arranged outside the discharge tube 5 to ignite by spark discharge. (5) The distance at which the tip of the inner tube 11 is separated inward from the tip of the probe antenna 9a is set to be equal to the distance between the tip of the probe antenna 9a and the energy concentration portion by the microwave unless the inner tube 11 is melted. Is best,
It may be appropriately changed in consideration of the melting of the inner tube 11. (6) The bubble dividing means 52 may be of a screw type in which a propeller is fixed to the tip of a shaft. (7) The neutralizing solution stored in the exhaust gas treatment tank 41 is not limited to the above-described alkaline suspension, and an alkaline aqueous solution such as a sodium hydroxide aqueous solution may be used.

[0062]

As is apparent from the above description, according to the present invention, the processing liquid is introduced into the cooling heat exchanger and is cooled by the air cooling fan, so that overheating of the system is prevented. Further, by adopting the air-cooling type, the size of the apparatus can be reduced as compared with the water-cooling type. When a fin-tube type heat exchanger is used as the cooling heat exchanger, the cooling heat exchanger may be clogged by the slurry, but the clogging of the cooling heat exchanger due to the strainer is provided. Is prevented. Furthermore, the provision of the three-way valve allows the processing liquid to be sent to the drainage processing apparatus. Thereby, the pump can be used also.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a decomposition apparatus used in an embodiment of a decomposition method according to the present invention.

FIG. 2 is a perspective view showing an entire configuration of the disassembling apparatus.

FIG. 3 is an enlarged view of a main part of the decomposition apparatus.

FIG. 4 is a comparison diagram showing the time when microwaves, argon gas and the like are supplied and the time of ignition in the decomposition apparatus over time.

FIG. 5 is a perspective view of an exhaust gas treatment tank shown as another example of the present invention.

[Explanation of symbols]

 15 Reaction tube 41 Exhaust gas treatment tank 53a Slurry pump (pump) 53b Air cooling fan 53c Cooling heat exchanger 53d Strainer (foreign matter removing means) 54 Thermocouple (temperature detecting means) 61 Control device (control means)

Claims (3)

[Claims] An apparatus for decomposing an organic halogen compound, comprising: a reaction tube for decomposing an organic halogen compound; and an exhaust gas treatment tank for neutralizing decomposition products decomposed in the reaction tube. The processing liquid sucked up by the pump is circulated between the pump for sucking up the processing liquid and the exhaust gas processing tank, and a cooling heat exchanger for cooling the processing liquid and blowing air to the cooling heat exchanger. Decomposition of an organic halogen compound, comprising: an air-cooling fan; temperature detection means for detecting the temperature of the processing liquid; and control means for controlling the rotation speed of the air-cooling fan based on a detection output of the temperature detection means. apparatus. 2. The apparatus for decomposing an organic halogen compound according to claim 1, further comprising foreign matter removing means for removing foreign matter from the processing liquid sucked up by said pump, wherein said cooling heat exchanger is a fin-tube type heat exchanger. An apparatus for decomposing an organic halogen compound, which is an exchanger. 3. The apparatus for decomposing an organic halogen compound according to claim 1 or 2, wherein a three-way valve interposed in the middle of a circulation path of the processing liquid, and the processing liquid is treated with the exhaust gas by switching the three-way valve. An apparatus for decomposing an organic halogen compound, comprising a tank and a drainage treatment device selectively fed.