JP2001172205A - Organic halide decomposer and the method of controlling the organic halide decomposer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic halide decomposer that can prevent the recovery bomb from lowering the temperature thereof and provide the control method for the organic halide decomposer. SOLUTION: The objective organic halide decomposer comprising the reactor tube 15 for decomposing organic halides and the recovery bomb 28 for receiving the organic halide to be decomposed in the reactor tube 15 is equipped with the heater 3 for heating the recovery bomb 28, the bomb pressure sensor PSW1 intervened on the way of the path for feeding the organic halide from the bomb 28 to the reactor tube 15 and the controller for controlling the heater 38 on the basis of the detection output of the bomb pressure sensor PSW1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for decomposing an organic halogen compound such as chlorofluorocarbon to render it 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]

By the way, in such a disassembly apparatus, the chlorofluorocarbon is stored as a liquid in a collected chlorofluorocarbon tank, and is supplied by its internal pressure. However, if CFCs are continuously removed from the CFC cylinder, the CFCs will be deprived of heat of vaporization, resulting in a low temperature of the CFC cylinder and a decrease in internal pressure. When the internal pressure is reduced, it becomes impossible to take out the CFC gas from the CFC cylinder even though CFCs are sufficiently left in the CFC cylinder, causing a problem that CFC decomposition becomes impossible.

In view of the above circumstances, it is an object of the present invention to provide an apparatus for decomposing an organic halogen compound and a method for controlling the apparatus for decomposing an organic halogen compound, which can prevent the temperature of the recovery cylinder from lowering.

[0008]

Means for Solving the Problems In order to solve the above problems, the present invention employs the following constitution. Claim 1
In a device for decomposing an organic halogen compound, comprising: a reaction tube that decomposes an organic halogen compound according to claim 1, and a recovery cylinder that stores the organic halogen compound decomposed in the reaction tube, a heater that heats the recovery cylinder, A cylinder pressure sensor interposed in the middle of the path of the organic halogen compound supplied from the collection cylinder to the reaction tube; and a control device for controlling the heater based on a detection output of the cylinder pressure sensor. Features.

In this apparatus for decomposing an organic halogen compound, the pressure of the cylinder is monitored and the heater is controlled to heat the cylinder, thereby preventing the pressure of the cylinder from lowering.

According to a second aspect of the present invention, in the organic halogen compound decomposing apparatus according to the first aspect, the recovery cylinder is provided downstream of the cylinder pressure sensor in the organic halogen compound supply path. A throttle device for reducing the pressure of the organic halogen compound supplied to the reaction tube is provided, and a supply pressure sensor for detecting the pressure of the organic halogen compound is provided downstream of the throttle device,
The control device controls the heater based on detection outputs of the cylinder pressure sensor and the supply pressure sensor.

In this apparatus for decomposing an organic halogen compound, by providing not only a cylinder pressure sensor but also a supply pressure sensor, an empty state of the cylinder can be detected as described later. The control method of these organic halogen compound decomposing devices can be performed as follows.

According to a third aspect of the present invention, there is provided a method for controlling an organic halogen compound decomposing apparatus, comprising: a reaction tube for decomposing an organic halogen compound; and a recovery cylinder containing the organic halogen compound decomposed in the reaction tube. In the control method of the decomposition apparatus, a heating means for heating the recovery cylinder, and a pressure of the organic halogen compound in the recovery cylinder, which is interposed in a path of the organic halogen compound supplied to the reaction tube from the recovery cylinder. Cylinder pressure detection means for detecting the cylinder pressure, and control means for controlling the heating means based on the detection output of the cylinder pressure detection means, the control means, when the cylinder pressure is less than a predetermined And operating the heating means to heat the recovery cylinder.

According to a fourth aspect of the present invention, there is provided a method for controlling an organic halogen compound decomposing apparatus according to the third aspect of the present invention, further comprising: A throttle device for reducing the pressure of the organic halogen compound supplied to the reaction tube from the recovery cylinder, and a supply pressure detecting means for detecting a supply pressure that is a pressure of the organic halogen compound downstream of the throttle device. Control means for controlling the heating means based on detection outputs of the cylinder pressure detection means and the supply pressure detection means, the control means comprising: When the pressure is equal to or less than a predetermined value, the heating means is operated to heat the recovery cylinder.

In the control method of the organic halogen compound decomposing apparatus, when the supply pressure is equal to or higher than a predetermined value and the cylinder pressure is equal to or lower than a predetermined value, it is possible to supply an organic halogen compound sufficient to decompose. However, since it can be detected that the pressure is decreasing, the recovery cylinder is heated. If the supply pressure drops below a predetermined level despite heating the recovery cylinder, it can be determined that the recovery cylinder is empty.

As means for heating the recovery cylinder,
The following may be performed. That is, the apparatus for decomposing an organic halogen compound according to claim 5 includes a reaction tube that decomposes the organic halogen compound, a recovery cylinder that contains the organic halogen compound that is decomposed in the reaction tube, and a device that is decomposed in the reaction tube. An apparatus for decomposing an organic halogen compound, which includes an exhaust gas treatment tank containing an alkali solution for neutralizing a decomposition product of the organic halogen compound, wherein the recovery cylinder is heated by the alkali solution. Since the alkali solution generates heat by neutralization, the temperature of the cylinder can be prevented from lowering by utilizing the heat generation as described above. More specifically, a pipe through which an alkaline solution flows and a recovery cylinder are both immersed in water, and the water is heated with the alkaline solution, thereby heating the recovery cylinder as a hot water bath.

[0016]

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.

[0019] 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 comprises an inner tube 11 and an outer tube 12, 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 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.

The 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. Between the argon cylinder 21 and the solenoid valve 19a, a throttle device 20, a pressure switch 23,
A flow regulator 22 is provided.

Air is supplied from the air compressor 24 to remove water remaining in the system to enhance ignition stability 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 a liquid collection tank (collection cylinder) 28, and a strainer 31 for removing foreign substances, an oil (lubricating oil) and moisture are provided between the collection chlorofluorocarbon cylinder 28 and the solenoid valve 19b. An oil separator 32 to be removed, a pressure switch PSW1 (cylinder pressure sensor, cylinder pressure detecting means), a throttle device 30, and a pressure switch PSW2 (supply pressure sensor, supply pressure detecting means) flow controller 33 are provided.

The expansion device 30 is for reducing pressure. The pressure switches PSW1 and PSW2 are turned on when the pressure drops, and the pressure switches PSW1 and PSW2 are respectively turned on.
Are provided on the upstream side and the downstream side. The pressure at which these pressure switches PSW1 and PSW2 are turned on is different. The pressure switch PSW1 on the upstream side is turned on when the pressure is about 6 kg / cm ² or less, and the pressure switch PSW2 is turned on under the condition that the pressure is lower than the pressure switch PSW1. .

Further, an electric heater (heating means) 38 is provided in the CFC cylinder 28, and the CFC cylinder 28 is heated by energization. The control device (control means) 61 (see FIG. 3) has a pressure switch PSW.
1. The detection outputs of the PSW 2 are input, and the electric heater 38 is controlled based on these detection outputs.

The heater 18 not only generates water vapor to be reacted with the chlorofluorocarbon gas, but also preheats the chlorofluorocarbon gas and the like to avoid a problem that the water vapor is cooled down to the chlorofluorocarbon gas and recondensed in the apparatus. And 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, or 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 like having passed through the heater 18 and the steam 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 blowing 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 when the fluorocarbon gas is decomposed and blown out from the blowing pipe 45. In addition, an alkaline suspension obtained by adding calcium hydroxide to water (hereinafter simply referred to as an alkaline solution) is contained. For example, when the Freon gas to be decomposed is Freon R12 for a refrigerant recovered from a waste refrigerator, the acidic 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

The neutralized products (calcium chloride and calcium fluoride) produced by the neutralization reaction of the formula (2) have a low solubility, so that a part of them is 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
The control device 61 (see FIG. 3) constantly monitors the pH value via the pH sensor 55. For example, when the pH value becomes 9 (11 to 12 at the start of operation), the alarm means is activated by a command from the control device 61. At the same time, the disassembly operation is stopped. As the warning means, any means can be used as long as it can draw attention to the surroundings. For example, means such as blinking a lamp or sounding a horn is adopted.

The exhaust gas treatment tank 41 is provided with a cooler 53 for cooling the alkaline liquid because the neutralization reaction of the formula 2 is an exothermic reaction. This cooler 53 is
A pump 53a for taking out the alkaline liquid from the bottom of the exhaust gas treatment tank 41, and a heat radiating section 53c through which the alkaline liquid passes and cooled by a fan 53b are provided. The alkaline liquid cooled by passing through the heat radiating portion 53c is:
It is returned to the exhaust gas treatment tank 41 again. Incidentally, the temperature in the tank is detected by the thermocouple 54.

Further, a three-way valve 56 is provided downstream of the radiator 53c. By switching the three-way valve 56, the alkaline liquid can be sent to the settling tank 62. A stirrer 62 is provided inside the settling tank 62.
a, a coagulant is added to an alkaline liquid containing a slurry to cause coagulation, and then solid-liquid separation is performed by a dehydrating basket 63 provided below the settling tank 62.

The procedure for decomposing chlorofluorocarbon in the organic halogen compound decomposing apparatus having the above 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 decomposer is started by supplying heated air for the purpose of removing water 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 a scavenging gas is supplied for a predetermined time (5 seconds) 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 alkaline liquid is agitated and neutralization is promoted. Thereafter, 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 is provided with the pressure switch 2
3, by receiving signals from various sensors such as PSW1, PSW2, thermocouples 36 and 54, level switch 27, and optical sensor 17, supply pressure of argon gas and Freon gas to heater 18, liquid level in water storage tank 26 , The plasma generation state and the temperature in the exhaust gas treatment tank 41 are constantly monitored, and if these deviate from specified values, the operation may not be performed normally or efficiently,
A predetermined process such as stopping the operation is performed. 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. 4 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.

Then, 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, microwaves are 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 strength is formed, and the electric field mode in the rectangular waveguide 1 and the cylindrical waveguide 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 inner conductor 9 and the ignition. 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 start of the supply of the steam, the supply of the chlorofluorocarbon gas is started as described later. The reason for the first supply of the steam 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 certain 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 to supply Freon gas to the discharge tube 5. At this time, the Freon gas flowing out of the collected Freon cylinder 28
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 water vapor, the argon gas, and the fluorocarbon gas flowing into the mixer 37 after passing 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.

Now, in the CFC cylinder 28, CFC is stored as a liquid, and the CFC is stored in the CFC cylinder 28.
From the container, the heat of vaporization causes CFC cylinder 2
8 becomes low temperature and the pressure drops. In order to prevent this, the control device 61 performs the control shown in FIG. First,
At step SP1, the output of the pressure switch PSW2 is determined. If the pressure switch PSW2 is on (pressure drop), it is detected whether or not it is in the decomposition mode (SP2). In the case of the disassembly mode, it is determined that the Freon stored in the Freon cylinder 28 is empty, and a stop process is performed. If not in the disassembly mode, error processing is performed. If the pressure switch PSW2 is off in step SP1, step S
At P3, the output of the pressure switch PSW1 is determined.
If the pressure switch PSW1 is on, the electric heater 38
Is turned on and off, and if it is on, the process is terminated; if it is off, the electric heater 38 is energized (step SP
5). As described above, when the pressure switch PSW2 is off and the pressure switch PSW1 is off (in the case of step SP3), it is possible to supply an amount of Freon sufficient to decompose, but the pressure is decreasing. Therefore, it is possible to prevent the decomposition from being impossible by heating the CFC cylinder. The above determination is performed sequentially during the decomposition of CFCs.

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 produced gas released into the alkaline solution through the blowing pipe 45 is rendered harmless by the neutralization reaction of the formula (2). Since the neutralization reaction is an exothermic reaction, the temperature of the alkaline solution is maintained at about 60 ° C. or lower by the cooler 53.

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 the decomposition operation is stopped, the bubble separating means 52 is stopped, then the alkaline liquid is pumped up by the pump 53a, and the three-way valve 56 is switched to be transferred to the settling tank 62. The alkali solution transferred to the settling tank 62 is stirred by the stirrer 6
The coagulant is added uniformly while stirring with 2a, and a stirrer 62a
Is stopped and sedimentation is performed, followed by solid-liquid separation in the dehydrating basket 63, the liquid component is subjected to wastewater treatment, and the solid component is discarded. After the decomposition 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 this example, when the pressure of the CFC cylinder 28 decreases, the controller 61
Heats the CFC cylinder 28, so that the temperature of the cylinder 28 is prevented from lowering, so that the decomposition of the organic halogen compound due to the lowering of the temperature can be prevented. Also, by providing two pressure switches PSW1 and PSW2,
The fact that the freon cylinder 28 is empty can also be detected.

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) In the above description, the control device 61 controls the electric heater 38, but the pressure switch PSW1 or PSW2 may directly turn the heater 38 on and off regardless of the control device 61. In this case, the pressure switch PSW1,
The PSW 2 plays a role of a control device (control means). (2) As a means for heating the CFC cylinder 28, an alkaline liquid may be used as shown in FIG. The collection cylinder 28 is placed in the container 65 as shown. Water is introduced into the vessel 65, and the recovery cylinder 28 and the pipe 64 extending from the cooling system of the exhaust gas treatment tank 41 are both immersed in water, and the water is heated by the alkali liquid in the pipe 64,
The recovery cylinder 28 is heated as a hot water bath. In this example, control based on the detection of the pressure switches PSW1 and PSW2 is not necessary, and the recovery cylinder 28 may be always heated. (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.

[0066]

As is apparent from the above description, in the present invention, the temperature of the recovery cylinder is prevented from lowering, so that it is possible to prevent the organic halogen compound from being decomposed due to the temperature lowering.

[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 an enlarged view of a main part of the decomposition apparatus.

FIG. 3 is a perspective view showing an entire configuration of the disassembling 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 control diagram showing control of heating the CFC in the decomposition apparatus.

FIG. 6 is a system diagram showing a disassembling apparatus shown as another example of the present invention.

[Explanation of symbols]

 15 Reaction tube 41 Exhaust gas treatment tank 28 Recovered freon cylinder (recovered cylinder) 33 Throttling device 38 Electric heater (heater) 61 Controller (control means) PSW1 Cylinder pressure sensor (cylinder pressure detecting means) PSW2 Supply pressure sensor (supply pressure detecting means) )

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Bessho 1-Fujimichi, Iwazuka-cho, Nakamura-ku, Nagoya City, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Research Laboratory F-term (reference) 2E191 BA12 BD18 4G075 AA13 AA37 BA05 BA06 BB02 CA02 CA48 CA57 CA62 CA63 EB41 4H006 AA04 AA05 AC13 AC26 BA91 BA95 BB61 BE01 BE60

Claims (5)

[Claims] An apparatus for decomposing an organic halogen compound, comprising: a reaction tube for decomposing an organic halogen compound; and a recovery cylinder for containing the organic halogen compound decomposed in the reaction tube, wherein a heater for heating the recovery cylinder is provided. A cylinder pressure sensor interposed in the middle of the path of the organic halogen compound supplied from the recovery cylinder to the reaction tube; and a control device for controlling the heater based on a detection output of the cylinder pressure sensor. An apparatus for decomposing an organic halogen compound. 2. The organic halogen compound decomposer according to claim 1, wherein the pressure of the organic halogen compound supplied to the reaction tube from the recovery cylinder downstream of the cylinder pressure sensor in the organic halogen compound supply path. A supply pressure sensor that detects the pressure of the organic halogen compound is provided on the downstream side of the restriction device, and the control device is configured to detect the pressure of the organic halogen compound based on the detection output of the cylinder pressure sensor and the supply pressure sensor. An apparatus for decomposing an organic halogen compound, wherein the apparatus controls the heater. 3. A method for controlling an organic halogen compound decomposing apparatus, comprising: a reaction tube for decomposing an organic halogen compound; and a recovery cylinder for containing an organic halogen compound decomposed in the reaction tube, wherein the recovery cylinder is heated. Heating means, cylinder pressure detecting means interposed in the middle of the path of the organic halogen compound supplied to the reaction tube from the recovery cylinder, and detecting a cylinder pressure which is a pressure of the organic halogen compound in the recovery cylinder, Control means for controlling the heating means based on the detection output of the cylinder pressure detection means, wherein the control means operates the heating means to heat the recovery cylinder when the cylinder pressure is equal to or lower than a predetermined value. A method for controlling an organic halogen compound decomposing apparatus, characterized in that: 4. The method for controlling an organic halogen compound decomposing apparatus according to claim 3, wherein the organic halogen compound is provided downstream of the cylinder pressure detecting means in an organic halogen compound supply path and supplied to the reaction tube from a recovery cylinder. A throttle device for reducing the pressure of the halogen compound; a supply pressure detection device for detecting a supply pressure that is a pressure of the organic halogen compound downstream of the throttle device; and a detection output of the cylinder pressure detection device and the supply pressure detection device. Control means for controlling the heating means on the basis of the control means, wherein the control means operates the heating means when the supply pressure is equal to or higher than a predetermined value and the cylinder pressure is equal to or lower than a predetermined value. A method for controlling an organic halogen compound decomposing apparatus, characterized by heating. 5. A reaction tube for decomposing an organic halogen compound, a recovery cylinder for containing the organic halogen compound decomposed in the reaction tube, and an alkali for neutralizing a decomposition product of the organic halogen compound decomposed in the reaction tube. An apparatus for decomposing an organic halogen compound, comprising an exhaust gas treatment tank containing a liquid, wherein the recovery cylinder is heated by the alkali liquid.