JP2003033644A - Organic halogen compound decomposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic halogen compound decomposition device which stably generates water vapor. SOLUTION: In this organic halogen compound decomposition device which is provided with a water vapor generator 18 in which, water vapor generated in the water generator 18 is reacted with organic halogen compound and the organic halogen compound is decomposed, the water vapor generator 18 is provided with a water vapor pipe 34b as a passage where water is gasified in the course that the water flows, a heater 88 which is disposed alongside of the water vapor pipe 34b and a throttling means 90 which is disposed on the outlet side of the water vapor pipe 34b and throttles the water vapor ejected from the water vapor pipe 34b.

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 CFCs.

[0002]

2. Description of the Related Art Organohalogen compounds such as chlorofluorocarbons (so-called CFCs) and trichloromethane containing fluorine, chlorine, bromine, etc. in their molecules are widely used in a wide range of applications such as refrigerants, solvents and fire extinguishing agents. , The importance in the industrial field is extremely high. However, these compounds are highly volatile, and if they are left untreated and released into the environment such as the atmosphere, soil, and water, the formation of carcinogenic substances, destruction of the ozone layer, etc.
Since it may adversely affect the environment, it is necessary to detoxify it from the viewpoint of environmental protection.

Conventionally, as a method for treating an organic halogen compound, there has been reported one mainly utilizing a thermal decomposition reaction at a high temperature, and this treating method is roughly classified into an incineration method and a plasma method. In the incineration method, an organic halogen compound is incinerated together with ordinary waste such as a resin, whereas in the plasma method, the organic halogen compound is reacted with water vapor in plasma to generate carbon dioxide, hydrogen chloride, and fluorine. It decomposes into hydrogen fluoride.

Further, as the operation control method of the latter organic halogen compound decomposing apparatus according to the plasma method, a method of generating plasma using microwaves has been developed in recent years. The decomposition apparatus used in this decomposition method includes an exhaust gas treatment tank containing an alkaline liquid, a reaction tube disposed with the opened lower end portion immersed in the alkaline liquid, and a vertical extension above the reaction tube. An existing cylindrical waveguide, a discharge tube disposed inside the cylindrical waveguide and penetrating the lower end thereof to communicate with the reaction tube, and extending horizontally and connected to the cylindrical waveguide in the vicinity of one end thereof. And a microwave transmitter attached to the other end of the rectangular waveguide.

In this decomposition apparatus, while the Freon gas and water vapor are supplied to the discharge tube, the microwave emitted from the microwave oscillator is transmitted to the cylindrical waveguide through the rectangular waveguide. Then, electric discharge is caused by the microwave electric field formed inside the cylindrical waveguide, and CFC gas is decomposed by thermal plasma in the reaction tube. On the other hand, this decomposition reaction produces acidic gases (hydrogen fluoride and hydrogen chloride).
This gas is introduced into the alkaline liquid by the blow-in pipe to be neutralized, and the remaining gas containing carbon dioxide and the like is discharged from the exhaust duct.

[0006]

Here, for example, the CFC R for the refrigerant in which the CFC gas to be decomposed is recovered from the waste refrigerator.
In the case of 12, decomposition is performed by the chemical formula shown in Formula 1.

(Formula 1) CCl ₂ F ₂ + 2H ₂ O → 2HCl + 2HF + CO ₂

As described above, it is necessary to supply water vapor (H ₂ O) to the discharge tube in order to decompose CFC gas. For this reason,
Although steam of water is generated by heating liquid water in a steam generator, it is difficult to generate steam in a stable manner, and pulsation occurs and mist-like water (mist) mixes with steam. There was a problem that the plasma would flow into the discharge tube. For this reason, there is a problem that instability of disassembly may occur and a discharge tube may be damaged.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an apparatus for decomposing an organohalogen compound which can stably generate water vapor.

[0010]

According to a first aspect of the present invention, there is provided a steam generator, wherein the steam generated in the steam generator reacts with an organic halogen compound to decompose the organic halogen compound. In the halogen compound decomposing apparatus, a flow path is formed that extends from one side of the steam generator to the other side and is folded back at the other side to extend to the one side. Further, a heater is provided in line with the flow path. It is characterized by being.

In the present invention, since the heaters are provided side by side in the flow path, the water is heated by the heater in the course of water flow and is discharged as water vapor.

According to a second aspect of the present invention, in the organic halogen compound decomposing apparatus according to the first aspect, the flow path is
A steam pipe in which water flows from the one side to the other side of the steam generator and the water is vaporized in the process;
It is composed of a decomposed gas pipe through which an organic halogen compound flows from one side of the steam generator to the other side, and the steam pipe and the decomposed gas pipe are joined at the other side of the steam generator. Is characterized by.

In the present invention, the organic halogen compound is heated together with water (steam) and then merges and is discharged as a mixture. Therefore, it is possible to prevent the mist from being generated due to the water vapor being cooled by the low temperature organic halogen compound.

According to a third aspect of the present invention, in the organic halogen compound decomposing apparatus according to the first aspect, the organic halogen compound is supplied to the other side of the steam generator at an intermediate portion of the flow path. An organohalogen compound supply port is provided, and the flow path includes a steam pipe through which water flows from one side to the other side of the steam generator and the water is vaporized in this process, and the steam generator. It is characterized in that it is constituted by a gas mixture tube through which a gas mixture of the water vapor and the organic halogen compound flows from the other side to the one side.

According to the present invention, water (steam) can be heated more sufficiently by reciprocating the steam generator and flowing through the steam pipe and the mixed gas pipe. In addition, by mixing the organic halogen compound in the middle, it is possible to heat as a mixture with the organic halogen compound. This prevents the water vapor from being cooled by the low-temperature organic halogen compound and generating mist.
Further, the pressure increases as the flow rate increases. As a result, the same effect as that provided with the throttle means is obtained, and the pressure fluctuation is reduced.

According to a fourth aspect of the present invention, in the organic halogen compound decomposing apparatus according to the second or third aspect, a mixture of the water vapor and the organic halogen compound is squeezed and discharged to the water vapor generator. A diaphragm means is provided.

The cause of unstable generation of water vapor is as follows: boiling → increase in heat transfer → decrease in heat transfer surface temperature → increase in vapor pressure loss → increase in boiling point → decrease in boiling → decrease in heat transfer rate → increase in heat transfer surface temperature → decrease in pressure → It is thought to be due to the mechanism of lowering the boiling point → boiling. In the present invention, the pressure of the air-fuel mixture is increased by the throttle means. When the pressure rises, the boiling point fluctuation with respect to the pressure fluctuation ΔP changes from ΔT1 → ΔT as shown in FIG.
Since the amount is small as shown in 2, stability of steam generation is improved.

The invention described in claim 4 is from claim 2 to claim 4.
In the apparatus for decomposing an organohalogen compound according to any one of the above, the inner wall surface of the steam pipe is roughened.

If the inner wall surface of the tube is smooth, a vapor film is formed between the inner wall and the liquid to form a heat insulating layer, which hinders boiling.
In the present invention, since the heat transfer surface is rough, the heat transfer performance is improved.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the apparatus for decomposing organic halogen compounds according to the present invention will be described with reference to FIGS. 1 to 8. In FIG. 1, a rectangular waveguide 1 extending in the horizontal direction has a frequency of 2.45G at its starting end.
The microwave transmitter 2 for transmitting the microwave of Hz is provided, and the microwave is transmitted from the start end side to the end side.

As shown in FIG. 1, the rectangular waveguide 1 absorbs the microwave reflected at the terminal end side and returned to the starting end side to prevent the reflected wave from affecting the transmitting side. There is provided an isolator 3 and a tuner 6 that adjusts the amount of wave-like mismatch of radio waves by entering and exiting the plurality of wave adjusting members 4 to converge the radio waves on the discharge tube 5.

Here, the microwave generation operation will be described. The microwave transmitter 2 is placed at one end of a waveguide having a rectangular cross section to drive a magnetron and radiate an electromagnetic wave of a predetermined frequency. The characteristic of this electromagnetic wave propagation phenomenon can be understood by solving Maxwell's wave equation relating to the electromagnetic wave, but as a result, it propagates as an electromagnetic wave TE wave having no electric field component in the propagation direction.

An example of this first-order component TE ₁₀ is shown in the direction of propagation of the rectangular waveguide of FIG. 2 by means of alternating arrows. Further, in the annular cavity of the double cylindrical waveguide formed of the double cylindrical conductor at the other end of the rectangular waveguide 1, the conductor 9 for the electromagnetic wave propagating through the waveguide 1 and the electromagnetic wave reflected at the tube end 9 Due to the coupling action by the, a TM wave having an electric field component in the traveling direction is generated in the annular cavity. The TM ₁₀ wave, which is the first-order component, is also indicated by an arrow in the annular cavity of FIG. The tuner 6 makes fine adjustments due to the second and higher harmonics involved in the propagation of electromagnetic waves. The isolator 3 prevents the microwave oscillator 2 from being fundamentally damaged.

Now, as shown in FIG. 2, the discharge tube 5 is composed of an inner tube 11 and an outer tube 120, and is arranged 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 diameter smaller than that of the outer conductor 8, and extends in the vertical direction in a state of communicating with the rectangular waveguide 1 in the vicinity of the end of the rectangular waveguide 1. Are connected as. The inner conductor 9 extends toward the end plate 8A of the outer conductor 8 while surrounding the quartz discharge tube 5 while being fixed to the upper portion of the rectangular waveguide 1, and this extending portion is used as a probe antenna 9a. There is. Further, an ignition electrode 14 connected to an ignition transformer 13 (see FIG. 1) is inserted in the inner tube 11 of the discharge tube 5. Further, the tip (lower end) of the inner tube 11 is arranged inward by a predetermined distance from the tip of the probe antenna 9a.

Now, as shown in FIG. 1, the cylindrical waveguide 7
The optical sensor 17 is provided between the reaction tube 15 and the reaction tube 15 toward the exposed outer tube 120. The optical sensor 17 monitors the plasma generation state by detecting the luminous intensity.

As shown in FIG. 2, the gas supply pipe 16 is provided in the gap between the inner conductor 9 and the base end of the outer pipe 120.
It is inserted along the tangential direction on the inlet side of the annular passage formed by the outer pipe 120 and the inner pipe 11. Argon gas (rare gas), Freon gas (organic halogen compound), air, and water vapor are supplied to the discharge tube 5 via the gas supply tube 16.
Is supplied to the annular passage. These argon gas, CFC gas, and air are used for the solenoid valves 19a and 19 shown in FIG.
By the opening and closing operations of b and 19c, they are selectively sent from the respective supply sources to the steam generator 18.

Argon gas is supplied to facilitate ignition prior to the generation of plasma, and is stored in the 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 the water remaining in the system to improve the stability of ignition and to discharge the gas remaining in the system. , Nitrogen gas, argon gas, etc. are used. The steam is necessary for decomposing the CFC gas and is generated by sending the water in the water storage tank 26 to the steam generator 18 by the plunger pump 25. The water tank 26 has a level switch 2 for detecting a change in water level.
7 is provided.

The fluorocarbon gas is stored in the recovered fluorocarbon cylinder 28 as a liquid, and the recovered fluorocarbon cylinder 28 and the solenoid valve 1 are used.
9b, the expansion device 31, the mist separator 3
2 and a pressure switch 33 are provided. The expansion device 31 is provided for the purpose of quantifying the flow, and is composed of, for example, a combination of a capillary tube and an orifice.

The mist separator 32 is used to remove oil (lubricant) and water contained in the CFC gas, and a collision type or centrifugal separation type is adopted. The steam generator 18 not only generates steam that reacts with the chlorofluorocarbon gas, but also preheats the chlorofluorocarbon gas and the like to avoid the problem that the steam is chilled by the fluorocarbon gas and recondensed in the apparatus. It is provided intentionally, and heating methods such as electric type and steam type are adopted.

As shown in FIGS. 4 and 5, the steam generator 1
A channel 87 is formed in the inside 8 by the decomposed gas pipe 34a and the steam pipe 34b provided in parallel.
At the ends of the decomposed gas pipe 34a and the steam pipe 34b,
Since the confluent space is formed by the space 91 described below, the flow path 87 extends from one side (left side in the drawing) of the steam generator 18 to the other side, and is folded back at the other side to the one side. It has an extended shape. Further, a heater 88 is provided in parallel with the decomposed gas pipe 34a and the steam pipe 34b. Decomposed gas pipe 34a
CFC gas, argon gas, and air are introduced into the steam pipe 34b, and water is introduced into the steam pipe 34b from the water storage tank 26 to generate steam. The steam pipe 34b on the side where the steam is generated is filled with a resistor 35 that gives resistance to the steam moving in the steam pipe 34b, so that the steam cannot smoothly flow in the flow path. Has become.

As the resistor 35, an inorganic or organic granular, fibrous or porous material or a molded product thereof is adopted. From the viewpoint of preventing deterioration at high temperatures, SiO ₂ , Al is used. ₂ O ₃ , TiO ₂ , MgO, ZrO ₂
Inorganic materials such as oxides represented by, and carbides, nitrides and the like are preferable.

Further, on the inner wall surface 89 of the steam pipe 34b,
The inner wall is roughened by a method such as threading or brushing. A throttling means 90 is provided on the downstream side of the outlets of the decomposed gas pipe 34a and the steam pipe 34b, and the CFCs, water vapor, etc. discharged from the decomposed gas pipe 34a and the steam pipe 34b are connected to the throttling means 90. After joining in the space 91 formed between the decomposed gas pipe 34a and the steam pipe 34b, they are both throttled by the throttle means 90, and then supplied to the discharge tube 5 through the gas supply pipe 16. ing. As the throttle means 90, an orifice, a capillary or the like can be adopted.

Now, as shown in FIG. 2, the reaction tube 15 is provided with a blow tube 45 through an exchange joint 44. The exchange joint 44 is detachably connected between the reaction tube 15 and the blow tube 45.

The exhaust gas treatment tank 41 is provided to neutralize and detoxify the acidic gases (hydrogen fluoride and hydrogen chloride) generated when the CFC gas is decomposed and blown out from the blowing pipe 45. There, an alkaline suspension prepared by adding calcium hydroxide to water (hereinafter simply referred to as an alkaline solution) is contained. For example, in the case where the CFC to be decomposed is CFC R12 for a refrigerant recovered from a waste refrigerator, the acid gas generated by the decomposition reaction shown in Formula 1 is rendered harmless 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 neutralization products (calcium chloride and calcium fluoride) produced by the neutralization reaction of the formula 2 have a low solubility, some of them are dissolved in the alkaline solution, but most of them exist as a slurry. Further, the carbon dioxide produced 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 exhaust duct 42 connected above the exhaust gas treatment tank 41. Is discharged from the system by the blower 43.

From the tip (lower end) of the blow pipe 45, the gas produced by the decomposition reaction of the formula 1 is released as bubbles in the alkaline solution. Since the larger the contact area with the bubble and the longer it takes for the bubbles to reach the liquid surface, the bubbles are promoted in the exhaust gas treatment tank 41 by finely dividing the bubbles to promote the neutralization reaction of Formula 2. A dividing means 52 is provided.

The bubble cutting means 52 is provided with six blades 52b which are rotationally driven by a motor 52a. The bubble dividing means 52 is arranged such that the blade 52b is located above the tip of the blow pipe 45, and the bubbles floating from the tip of the blow pipe 45 hit the blade 52b rotating at about 300 rpm and have a diameter of about 3 mm to 5 mm. It is divided into small bubbles. Further, the bubble dividing means 52 also plays a role of producing a suspension of water-insoluble calcium hydroxide and water by stirring the calcium hydroxide powder put into the exhaust gas treatment tank 41. Air bubble dividing means 52
Keeps the operating state from the start to the end of the operation of the plasma decomposition apparatus. Keep it in a stopped state except during the operating period of the disassembling device.

Further, the exhaust gas treatment tank 41 has a pH of
A sensor 55 is provided. The pH value of alkaline solution is
It is constantly monitored by the control device 61 (see the overall configuration diagram of FIG. 3) via the pH sensor 55. For example, when the pH value becomes 9 (11 to 12 at the start of operation), the control device 6
The alarm means is activated in response to the command from No. 1 and the disassembly operation is stopped. Any warning means can be used as long as it can draw attention to the surroundings.
For example, means such as blinking a lamp or smoothing a horn is adopted.

Further, since the neutralization reaction of the equation 2 is an exothermic reaction, the exhaust gas treatment tank 41 is provided with a cooler 53 for cooling the alkaline liquid. This cooler 53
The exhaust gas processing tank 41 is provided with a pump 53a for taking out the alkaline liquid from the bottom, and a heat radiating portion 53c through which the alkaline liquid passes and is cooled by a fan 53b. The alkaline liquid cooled by passing through the heat dissipation portion 53c is
It is returned to the exhaust gas treatment tank 41 again. By the way, the temperature inside the tank is detected by the thermocouple 54.

Further, a three-way valve 56 is provided on the downstream side of the heat radiating portion 53c, and by switching the three-way valve 56, an alkaline liquid containing slurry as a processing liquid can be sent to the settling tank 62. Has become. A stirrer 62a is provided inside the settling tank 62, and after a coagulant is added to the treatment liquid to cause coagulation, solid-liquid separation is performed by a dehydrating basket 63 provided below the settling tank 62. ing.

The procedure for decomposing freon in the decomposition apparatus for an organic halogen compound having the above-mentioned structure will be described. The opening / 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 can be seen from this figure, this decomposition device
Freon gas is decomposed by batch processing in which the time is one cycle.

That is, before supplying CFC gas or water vapor, first, the air heated for the purpose of removing the water remaining in the system is supplied for a predetermined time (3 minutes) to start the operation of the decomposition apparatus. To do. At this time, the operation of the bubble dividing means 52 is also started at the same time. After the air supply is stopped, the supply of argon gas is started to improve the ignition stability. Then, while the argon gas is being supplied, microwaves are emitted to ignite by the ignition transformer 13, and steam and chlorofluorocarbon are supplied to decompose chlorofluorocarbon. Then, the supply of argon gas is stopped. The water may be removed by drying the air.

After the disassembling operation is stopped, air as scavenging gas is kept for a predetermined time (5
Min) is supplied and residual acid gas is purged. The purged acidic gas is neutralized in the exhaust gas treatment tank 41. At this time, by keeping the bubble dividing means 52 in an operating state, the alkaline liquid is stirred and neutralization is promoted. Then, the purging is stopped and the operation of the decomposition apparatus is completed. At the same time, the motor 52a is stopped and the operation of the bubble cutting means 52 is stopped. Since the stirring in the exhaust gas treatment tank 41 is stopped by stopping the bubble dividing means 52, the slurry is precipitated in the tank 41.

In the above steps, the supply of the argon gas and the supply of the freon gas may overlap each other, but the time from the start of the supply of the freon gas to the stop of the supply of the argon gas may be very small. The reason is,
This is because it is not necessary to continue supplying the argon gas as long as the ignition state is stable, and it is necessary to keep the argon consumption low from the viewpoint of cost reduction. In particular, microwave plasma is more stable than other plasmas such as high frequency induction plasma,
Even if the supply of the argon gas is stopped, there is almost no effect on the plasma conversion of the CFC gas.

Further, the control device 61 includes the pressure switch 2
By receiving signals from various sensors such as 3, 33, thermocouple 54, level switch 27, and optical sensor 17, the supply pressure of argon gas and Freon gas to the steam generator 18, the liquid level in the water storage tank 26, the plasma The generation state of
The temperature inside the exhaust gas treatment tank 41 is constantly monitored, and if these deviate from the specified values, the operation may be stopped normally or efficiently, so the operation is stopped. Then, after the operation is stopped, air is supplied as described above to ensure safety, and residual gas in the device is scavenged.

Next, the step of CFC decomposition shown in FIG. 8 will be described in more detail. First, the solenoid valve 19a,
By closing 19b and opening the solenoid valve 19c, the air from the air compressor 24 is supplied to the discharge tube 5 through the gas supply tube 16 for 3 minutes. This air is heated to 100 to 180 ° C. by passing through the steam generator 18. For this reason, the residual moisture in the device is surely removed, and the stability of ignition is improved.

Then, the electromagnetic valve 19c is closed and the electromagnetic valve 19a is opened to supply the argon gas to the discharge tube 5. At this time, since the argon gas is supplied from the tangential direction of the outer tube 120 and flows down in a spiral shape, 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, preferably 15 l / min or more. In this setting range, stagnation is effectively formed, plasma is more easily retained, and the discharge tube 5 is less susceptible to the thermal influence of plasma, and its melt deformation and damage are effectively prevented. Become.

Then, a microwave is transmitted from the microwave transmitter 2 at a constant interval from the start of supplying the argon gas. The microwave is transmitted to the rear end side of the rectangular waveguide 1 and further 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 strength is formed, and the inner conductor 9 causes the electric field mode in the rectangular waveguide 1 and the cylindrical waveguide 1. Since the electric field mode in 7 is coupled, the electric field in the cylindrical waveguide 7 is stable. Naturally, the magnetic field is generated in the direction orthogonal to the electrolysis. The gas introduced into the discharge tube 5 is heated to a plasma state by the vibrating 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 itself and the inner conductor 9 to ignite it. At this time, the interior of the discharge tube 5 is easily ignited because the moisture is removed by air and the argon gas which is easy to ignite is supplied in advance. Next, the water tank 2 is driven by the plunger pump 25.
Water is sucked from 6 and passed through a steam generator 18 to supply the generated steam to the discharge tube 5.

After the supply of steam is started, the supply of CFC gas is started as described later. The reason for supplying steam first is as follows. In the method for controlling the operation of the decomposition apparatus for an organohalogen compound according to the present embodiment, CFCs and water vapor are supplied at a constant molar ratio for decomposition and reaction,
Generates acid gas. This is because if only the Freon gas is turned into plasma, unexpectedly harmful halogen compounds are generated due to recombination of dissociated atoms, and the harmless treatment cannot be performed. Therefore, as described above, by supplying the steam to the discharge tube 5 and then supplying the chlorofluorocarbon gas so that the steam is present during the chlorofluorocarbon decomposition,
CFC can be safely disassembled.

Further, this steam cannot be smoothly circulated in the steam pipe 34b due to the resistor 35 filled in the steam generator 18, so that a constant amount of steam is always present in the steam generator 18. It becomes a stagnant state. For this reason,
It is possible to prevent scattering due to pulsation and bumping, stabilize the outflow amount of water vapor, and effectively suppress fluctuations in the upstream flow rate. Here, the throttle means 90 is provided on the outlet side of the steam pipe 34b.
Is provided, the pressure in the steam pipe 34b rises. When the pressure rises, the pressure fluctuation Δ as shown in FIG.
The fluctuation of the boiling point with respect to P is reduced as shown by ΔT1 → ΔT2, the stability of steam generation is improved, and pulsation and the like can be prevented. Further, since the inner peripheral wall surface 89 of the steam pipe 34b is roughened, the heat transfer performance is improved. Therefore, the boiling is not hindered, and as shown in FIG. 6 (a), the boiling region A does not fluctuate so much as it is located on the inlet side. When the boiling area B is located near the outlet as shown in FIG. 6 (b), a sufficient overheat area (indicated by reference numeral L2) cannot be obtained, and mist is mixed with the steam and discharged. . In this example, as shown by the symbol L1, a sufficient overheat region from the boiling region to the outlet can be taken, so that the steam is sufficiently overheated and the outflow of mist is prevented.

Then, the solenoid valve 19b is opened to supply the CFC gas to the discharge tube 5. At this time, the fluorocarbon gas flowing out from the recovered fluorocarbon cylinder 28 is collected by the mist separator 3
Oil and water are removed by passing through 2.
Therefore, the contamination of piping etc. and the generation of by-products due to the lubricating oil in the CFC gas are suppressed, and the CFC gas can be efficiently and stably supplied. Will not be lost. Therefore, it is possible to stabilize the plasma and improve the processing capacity.

Further, the decomposed gas pipe 34a and the steam pipe 34
The chlorofluorocarbon gas and water vapor that have passed through b are accelerated by passing through the squeezing means 90 and uniformly mixed, and then supplied to the discharge tube 5. Therefore, the decomposition reaction of Formula 1 is sufficiently performed, and the production of by-products such as chlorine gas and carbon monoxide can be suppressed.

When the Freon gas supplied to the discharge tube 5 in this manner is irradiated with microwaves, the inside of the discharge tube 5 is
High electron energy and temperature of 2,000K ~
A thermal plasma of 6,000K is generated. At this time, in the discharge tube 5, not only CFC gas and water vapor,
Since argon gas is also supplied at the same time, the plasma does not disappear.

Further, since the tip of the inner tube 11 is arranged inward of the tip of the probe antenna 9a by a predetermined distance, the thermal influence of the generated plasma can be avoided,
Melt damage of the inner pipe 11 is prevented. As a result, a stable decomposition operation is possible without significant deformation of the plasma shape.

However, due to the generation of thermal plasma, the CFC gas is in a state of being easily dissociated into chlorine atoms, fluorine atoms, and hydrogen atoms, so that it is easily decomposed by reacting with water vapor as shown in Formula 1. When the plasma stabilizes, the electromagnetic valve 19a is closed to stop the supply of argon gas. Therefore, when the CFC gas is decomposed for a long time, it is not necessary to supply argon, and the consumption of argon can be suppressed to a low level. The gas produced by the decomposition reaction passes through the exchange joint 44 and the blow pipe 45, and the exhaust gas treatment tank 4
It is released into the alkaline liquid in 1.

The product gas released into the alkaline solution through the blow pipe 45 is rendered harmless by the neutralization reaction of the equation 2. Since this neutralization reaction is an exothermic reaction, the temperature of the alkaline liquid is maintained at about 60 ° C. or lower by the cooler 53.

The produced gas released as bubbles from the tip of the blow pipe 45 is the blade 52 of the bubble dividing means 52.
Since it is finely divided upon hitting d, the contact area with the alkaline liquid increases and the time to reach the liquid surface also increases, facilitating the neutralization reaction. This prevents the amount of acid gas exceeding the standard value from being discharged out of the system due to insufficient neutralization treatment.

Of the produced gas detoxified by the neutralization reaction, the gas is discharged from the exhaust duct 42, and the gas other than the gas remains as a slurry in the alkaline liquid. After the disassembly operation is stopped, the bubble dividing means 52 is stopped, and then the treatment liquid is pumped up by the pump 53a, and the three-way valve 56 is switched to set this in the sedimentation tank 62.
Move to. The coagulant is uniformly added while stirring the treatment liquid transferred to the settling tank 62 with the stirrer 62a, and the stirrer 62a is stopped to cause precipitation, and then solid-liquid separation is performed in the dehydration basket 63,
The liquid content is treated as waste water, and the solid content is treated as waste. In addition,
After the disassembly operation is stopped, the air compressor 24 is driven to scavenge the acidic gas remaining in the apparatus, so that the safety is also improved.

As described above, in the present embodiment, since the steam generator 18 can stably generate steam, the CFC gas can be stably decomposed, and the discharge tube 5 is damaged. Etc. can be prevented.

Next, a second embodiment of the present invention will be described. The same components as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted. Further, the operation and effects other than the steam generator are the same as those in the first embodiment, and therefore the description thereof will be omitted. FIG. 9 shows a steam generator 95 according to this embodiment. A flow path 97 is formed in the steam generator 95 by a mixture pipe 96a and a steam pipe 96b provided in parallel. A space 98 is formed at the end of the steam pipe 96b, and further,
An organohalogen compound supply port 99 for supplying CFC gas is opened in the space 98. From the organic halogen compound supply port 99, in addition to CFC gas, argon gas and air are introduced. With this configuration, the flow path 97 has a shape that extends from one side (left side in the drawing) of the steam generator 95 to the other side, and is folded back at the other side to extend to the one side. Furthermore, the mixed trachea 9
A heater 88 is provided in parallel with 6a and the steam pipe 96b. Water is introduced into the steam pipe 96b from the water storage tank 26 to generate steam. The steam pipe 96b on the side that generates the steam is filled with a resistor 35 that gives resistance to the steam moving in the steam pipe 96b, so that the steam cannot flow smoothly in the flow path. Has become.

As the resistor 35, an inorganic or organic granular, fibrous or porous material or a molded material thereof is adopted. From the viewpoint of preventing deterioration at high temperatures, SiO ₂ , Al is used. ₂ O ₃ , TiO ₂ , MgO, ZrO ₂
Inorganic materials such as oxides represented by, and carbides, nitrides and the like are preferable.

The inner wall surface 100 of the steam pipe 96b is roughened by a method such as threading the inner wall or brushing.

In the steam generator 95, water is supplied from the water storage tank 26 in the freon decomposition step to generate steam. Specifically, the steam pipe 9
Water is supplied to 6b and heated by the heater 88 to become steam. This steam is steam pipe 96b
Due to the resistor 35 filled in, the steam pipe 96b cannot be smoothly circulated, and a constant amount of steam is always retained in the steam generator 95. For this reason,
It is possible to prevent scattering due to pulsation and bumping, stabilize the outflow amount of water vapor, and effectively suppress fluctuations in the upstream flow rate. Further, since the inner peripheral wall surface 100 of the steam pipe 96b is roughened, the heat transfer performance is improved and boiling is not hindered. The water vapor in the water vapor pipe 96b flows into the space 98, and becomes a gas mixture mixed with the CFC gas or the like supplied from the organic halogen compound supply port 99, and then flows into the gas mixture pipe 96a. The mixture is further heated by the heater 88 in the mixture tube 96a and then discharged from the steam generator 95. That is, in addition to being heated when passing through the water vapor tube 96b, it is also heated when passing through the mixture tube 96a, so that sufficient superheat is obtained and discharged. Therefore, the mist is prevented from flowing into the plasma discharge tube. As described above, in the organohalogen compound decomposing apparatus of the present embodiment, it is possible to prevent instability of decomposition caused by pulsation and mist flowing into the plasma discharge tube, damage to the discharge tube, and the like. further,
Since the chlorofluorocarbon gas is mixed with the water vapor in the process of passing through the flow passage 97, the mixed gas pipe 96a has a function of so-called throttling means, and the pressure inside the flow passage 97 is increased.
It is possible to obtain the effect of suppressing the pressure fluctuation as shown in the above embodiment. Further, even if the mist is discharged from the water vapor pipe 96b, the mist remains in the space 98, so that the mist does not easily flow into the air-fuel mixture pipe 96a on the downstream side, and the mist discharge prevention effect can also be obtained. further,
The steam generator 18 shown as the first embodiment,
It is possible to use a member having the same structure as that of the steam generator 95 shown as the second embodiment by changing the flow direction of the fluid.

Although the throttling means 90 is provided in the first embodiment, the throttling means 90 need not necessarily be provided if the pressure in the flow path is high because the diameter of the downstream pipe is small, for example. Further, a throttle means may be provided on the air-fuel mixture discharge side of the second embodiment. Furthermore, in the second embodiment, the air-fuel mixture tube 96a may also be roughened or provided with a resistor.

[0070]

As described above, the following effects can be obtained in the present invention. In the present invention, since the heater is provided in parallel with the flow path, the water is heated by the heater in the process of water flow and is discharged as water vapor (claim 1). According to the invention of claim 2,
The organic halogen compound is heated together with water (water vapor) and then merges to be discharged as a mixture. Therefore, it is possible to prevent the mist from being generated due to the water vapor being cooled by the low temperature organic halogen compound. According to the invention described in claim 3, water (steam) is sufficiently heated by flowing back and forth between the steam generator and the steam tube and the mixed gas tube, and the mist flows into the plasma discharge tube. Is prevented. Further, by mixing the organic halogen compound in the middle, it is possible to prevent water vapor from being cooled by the low temperature organic halogen compound and generating mist. In addition, the pressure increases due to the increase in the flow rate, and the same effect as the provision of the throttling means is obtained, and the pressure fluctuation is reduced
A stable decomposition of the organic halogen compound can be performed. According to the invention described in claim 4, since the pressure in the steam pipe is increased by the throttling means, the boiling point fluctuation with respect to the pressure fluctuation is reduced. Therefore, the stability of steam generation is improved. Further, the organic halogen compound passes through the throttle means together with the water vapor. For this reason, the steam and the organic halogen compound are mixed at a high speed flow at the outlet side of the throttle means, so that the organic halogen compound can be decomposed stably. According to the invention as set forth in claim 5, since the inner wall surface of the steam pipe is roughened, the heat transfer performance is improved and the steam can be sufficiently superheated so that the steam generation can be prevented. The stability can be improved.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of an organic halogen compound decomposing apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a part of a discharge tube and a reaction tube of the decomposition apparatus.

FIG. 3 is a perspective view showing an overall configuration of the disassembling apparatus.

FIG. 4 is a sectional view showing a configuration of a steam generator provided in the decomposition apparatus.

FIG. 5 is a perspective view in which a part of the steam generator is cut away.

FIG. 6 is a diagram showing a steam generation state in the steam generator, wherein (a) is a steam generator according to the present embodiment and (b) is a conventional steam generator.

FIG. 7 is a graph showing the relationship between pressure and boiling point.

FIG. 8 is a comparative diagram showing the timing of supplying microwaves, argon gas and the like and the timing of ignition with time in the decomposition apparatus.

FIG. 9 is a cross-sectional view showing a configuration of a steam generator used in the organic halogen compound decomposing apparatus shown as the second embodiment of the present invention.

[Explanation of symbols]

18 Steam generator 34a Decomposed gas pipe (flow path) 34b Steam pipe (flow path) 87 channel 90 Squeezing means 95 Steam generator 96a steam pipe 96b mixed trachea 97 channel 99 Organic halogen compound supply port

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // F22B 1/28 F22B 1/28 Z (72) Inventor Satoshi Hitoshi Asahi, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture 3-1, Machi Mitsubishi Heavy Industries Co., Ltd. Within the Refrigeration Business Headquarters (72) Inventor Soichiro Matsumoto 3-1-1, Asahicho, Nishibirashima-cho, Nishibashijima-cho, Nishikasugai-gun, Aichi Mitsubishi Heavy Industries, Ltd. F-Term (Reference) 4G075 AA03 AA37 AA42 AA61 BA01 BA05 BB02 BB05 BD12 BD27 CA02 CA15 CA25 CA47 CA57 DA01 DA05 EA06 EB01 EB41 EC01 EC11 ED02 FA20 FB04 4H006 AA04 AC13 AC26 BE60 EA02

Claims (5)

[Claims] 1. An organohalogen compound decomposing apparatus comprising a water vapor generator, wherein the water vapor produced in the water vapor generator reacts with an organic halogen compound to decompose the organic halogen compound, wherein one side of the water vapor generator From the organic halogen compound decomposing device, wherein a flow path is formed in a shape that extends from one side to the other side and folds back on the other side to extend to the one side, and further, a heater is provided in line with the flow path. . 2. The organohalogen compound decomposing apparatus according to claim 1, wherein water flows through the flow path from the one side to the other side of the steam generator, and the water is vaporized in the process. A steam pipe and a decomposed gas pipe in which an organic halogen compound flows from one side to the other side of the steam generator, and the steam pipe and the decomposed gas pipe are provided on the other side of the steam generator. An organic halogen compound decomposing device characterized by being merged. 3. The organohalogen compound decomposing apparatus according to claim 1, wherein the other side of the steam generator is provided with an organohalogen compound supply port for supplying an organohalogen compound to an intermediate portion of the flow path. The flow path includes a steam pipe in which water is vaporized from one side of the steam generator to the other side and the water is vaporized in this process, and the steam pipe is connected from the other side of the steam generator to one side. An apparatus for decomposing an organohalogen compound, comprising an air-mixing tube in which a mixture of the water vapor and the organohalogen compound flows. 4. The organohalogen compound decomposing apparatus according to claim 2, wherein the water vapor generator is provided with throttling means for throttling and discharging a mixture of the water vapor and the organic halogen compound. An apparatus for decomposing organic halogen compounds, which is characterized in that 5. The decomposition apparatus for an organohalogen compound according to claim 2, wherein an inner wall surface of the water vapor pipe is roughened. apparatus.