JP2003175331A - Organic halogen compound decomposition equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide organic halogen compound equipment that is capable of surely preventing the fusion breakage of a blowing pipe by restraining the peeling and reattachment of a high temperature gas from and to an inner face of the pipe. <P>SOLUTION: The organic halogen compound decomposition equipment is provided with a reaction pipe 37 which decomposes the organic halogen compound to high temperature decomposition gases and allows them to flow down and the blowing pipe 45 of which the starting end is connected with the flowing down end of the reaction pipe 37 and of which the terminal is immersed in an alkaline solution to blow the decomposition gas into the alkaline liquid, wherein the inside diameter of the blowing pipe 45 is smaller than that of the reaction pipe 37. The equipment is characterized by providing the bent surface of the blowing pipe 45 which is protruded in the direction of the inside of the pipe and which makes the inner wall surface of the reaction pipe 37 and the inner wall surface of the blowing pipe 45 continuous. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organohalogen compound decomposing apparatus for decomposing organic halogen compounds such as CFCs, and more particularly to a blowing pipe connecting portion connected to a reaction pipe that is heated to a high temperature for decomposing organic halogen compounds. Regarding improvement.

[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.

This detoxification treatment includes, for example, a plasma method in which an organic halogen compound is reacted with water vapor in plasma to decompose it into carbon dioxide, hydrogen chloride and hydrogen fluoride. In this plasma method, an organohalogen compound decomposing device that uses microwaves to generate plasma is used.

This type of decomposition apparatus comprises an exhaust gas treatment tank for containing an alkaline liquid, a blow pipe arranged with its open lower end immersed in the alkaline liquid, and a reaction pipe connected to the upper end of this blow pipe. A cylindrical waveguide extending vertically above the reaction tube, a discharge tube disposed inside the cylindrical waveguide and communicating with the reaction tube through a lower end thereof, and a discharge tube extending horizontally. A rectangular waveguide connected to the cylindrical waveguide in the vicinity of one end of the rectangular waveguide and a microwave transmitter mounted on the other end of the rectangular waveguide are provided.

In this decomposition apparatus, while the CFC gas and the 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.

Here, the alkaline liquid is a suspension of water and calcium hydroxide insoluble in water. Then, the following neutralization reaction is carried out in this alkaline liquid. 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.

[0009]

By the way, the high temperature gas of 700 to 800 ° C. decomposed by the plasma in the reaction tube is introduced into the alkaline liquid through the blowing tube connected to the lower end thereof. Therefore, a metal material is used for the reaction tube in order to improve heat resistance, and a resin material is used for the blow tube in order to improve corrosion resistance. In addition, it is desirable to keep the residence time at an appropriate length in order to improve the decomposition performance of the reaction tube, while the blow-in tube on the downstream side where the gas temperature gradually lowers has a residence time to suppress the formation of dioxins and the like. It is desirable to shorten the time. Therefore, in the conventional organohalogen compound decomposing apparatus, the diameter of the upstream reaction tube is larger than the diameter of the downstream blowing tube. This also has the advantage that the length of the reaction tube can be shortened. Further, there is an advantage that the material cost of the blow-in pipe is low and the availability is easy. As shown in FIG. 6, the reaction tube having a different diameter and the blow tube have a large-diameter reaction tube 1 through a taper 5 provided at the start end of the blow tube 3 for gradually reducing the diameter in the gas flow direction. And was connected to the small diameter blow pipe 3. However, when the taper 5 whose inner diameter is linearly reduced is provided, a corner portion 7 projects between the taper 5 and the inner wall of the blow pipe 3. From this, the streamline G of the high temperature gas flowing along the tapered surface
Since the direction of the VL suddenly changes due to the corner portion 7, it peels from the inner surface of the pipe, and after advancing for a while, reattaches to the inner surface of the pipe. For this reason, the inner wall surface of the reattachment site 9 becomes high in temperature due to high heat transfer, and melting breakage easily occurs. If melt damage occurs, the decomposed gas will flow out, and the safety and stability of the device will be reduced. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an organohalogen compound decomposing device capable of reliably preventing melt damage of a blow pipe by suppressing peeling from a pipe inner surface of high-temperature gas and redeposition. To do.

[0010]

In order to achieve the above object, the apparatus for decomposing an organohalogen compound according to claim 1 of the present invention comprises a reaction tube for decomposing an organohalogen compound into a decomposition gas at a high temperature and flowing it down. A blower pipe having a starting end connected to the lower end of the reaction tube and a terminal end immersed in an alkaline liquid to blow the decomposition gas into the alkaline liquid, the inner diameter of the blowing pipe being smaller than the inner diameter of the reaction pipe. In the organic halogen compound decomposing apparatus described above, a curved surface is provided at the start end of the blow-in pipe so as to project inward of the pipe and connect the inner wall surface of the reaction pipe and the inner wall surface of the blow-in pipe to each other.

In this apparatus for decomposing organic halogen compounds, the corners when a taper surface that linearly reduces in diameter is formed at the start end of the blow-in pipe are eliminated, and the hot gas flows along the curved surface. Therefore, phenomena such as peeling and redeposition of flowing high-temperature gas can be suppressed. This prevents the inner wall surface of the blow pipe from becoming hot due to high heat transfer,
In particular, melting damage does not occur even with a blow pipe made of a resin material. Further, it becomes possible to use an existing reaction tube.

The organic halogen compound decomposing apparatus according to a second aspect is the organic halogen compound decomposing apparatus according to the first aspect, wherein the inner wall surface of the reaction tube is at the lower end of the flow path and the inner wall surface extends along the streamline of the decomposed gas. It is characterized in that a bulging curved surface is provided which bulges to connect the inner wall surface of the reaction tube and the curved surface of the blowing tube.

In this organohalogen compound decomposing apparatus, there is no corner portion when a taper surface that linearly reduces in diameter is formed at the start end of the blow-in pipe, the separation and re-adhesion of flowing hot gas can be suppressed, and the blow-in pipe can be prevented. Prevent the inner wall surface of the
In particular, even if the blow pipe is made of a resin material, melting damage does not occur, and since the bulging curved surface eliminates recesses in the connecting portion between the lower end of the reaction tube and the curved surface of the blow pipe, stagnation of high temperature gas also occurs. It can be prevented and pressure loss can be reduced.

An apparatus for decomposing an organohalogen compound according to a third aspect of the invention comprises a reaction tube for decomposing an organohalogen compound into a decomposition gas at a high temperature and flowing down the reaction tube, a starting end connected to the lower end of the reaction tube and an alkaline liquid ending at the end. In an organohalogen compound decomposing device in which the blower tube is immersed to blow the decomposition gas into the alkaline liquid, and the inner diameter of the blower tube is smaller than the inner diameter of the reaction tube, the reaction is performed at the start end of the blower tube. A short pipe portion having the same inner diameter as the pipe is provided, and the inner wall surface of the short pipe portion and the blow pipe are arranged along the streamline of the decomposition gas between the inner wall surface of the short pipe portion and the inner wall surface of the blow pipe. It is characterized in that a curved surface is provided which is continuous with the inner wall surface of.

In this organohalogen compound decomposing apparatus, a corner portion is eliminated when a taper surface that linearly reduces in diameter is formed at the start end of the blow-in pipe, and the hot gas flows and flows along the short pipe portion and the curved surface. It is possible to suppress the phenomenon such as peeling and redeposition of the high temperature gas that occurs. This prevents the inner wall surface of the blow-in pipe from reaching a high temperature due to high heat transfer, and in particular, even in the case of the blow-in pipe made of a resin material, melting damage does not occur.
Further, no recess is formed at the connecting portion between the lower end of the reaction tube and the curved surface, and stagnation of high temperature gas can be prevented. Further, it becomes possible to use an existing reaction tube.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the apparatus for decomposing organic halogen compounds according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an outline of an organohalogen compound decomposing apparatus according to the present invention, FIG. 2 is a cross-sectional view showing a portion of a reaction tube and a blowing tube shown in FIG. 1, and FIG. 3 is a connecting portion between a reaction tube and a blowing tube. FIG. 3 is an enlarged cross-sectional view showing only one side of the axis.

In FIG. 1, a rectangular waveguide 11 extending in the horizontal direction is provided with a microwave oscillator 13 for transmitting a microwave having a frequency of 2.45 GHz at a starting end thereof, and the microwave is transmitted from the starting end side to the terminal end side. Transmit microwaves.

The rectangular waveguide 11 absorbs the microwaves reflected at the terminal end side and returned to the start end side, thereby preventing the reflected wave from affecting the transmitting side.
5 and a tuner 21 that adjusts the amount of wave-like mismatch of the electric wave by moving in and out of the plurality of wave adjusting members 17 to focus the electric wave on the discharge tube 19.

The microwave transmitter 13 is placed at one end of a waveguide having a rectangular cross section and drives a magnetron to radiate an electromagnetic wave having 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 TE10 is shown by alternating arrows in the propagation direction of the rectangular waveguide of FIG. Further, in the annular cavity of the double cylindrical waveguide formed of the double cylindrical conductor at the other end of the rectangular waveguide 11, the conductor 23 for the electromagnetic wave propagating through the waveguide 11 and the electromagnetic wave reflected at the tube end 23. Due to the coupling action of the TM, the annular cavity has an electric field component in the traveling direction.
Waves occur. The TM10 wave, which is the first-order component, is also indicated by an arrow in the annular cavity of FIG. The tuner 2 can be used to make fine adjustments due to the harmonics of the second order and higher that are related to the propagation of electromagnetic waves.
Adjusted by 1. The isolator 15 prevents the microwave oscillator 13 from being fundamentally damaged.

As shown in FIG. 2, the discharge tube 19 is composed of an inner tube 25 and an outer tube 27, and is arranged so as to be coaxial with the central axis of the cylindrical waveguide 29. The cylindrical waveguide 29 is composed of an outer conductor 31 and an inner conductor 23 having a diameter smaller than that of the outer conductor 31, and extends in the vertical direction in a state of communicating with the rectangular waveguide 11 in the vicinity of the end of the rectangular waveguide 11. Are connected as. The inner conductor 23 is fixed to the upper portion of the rectangular waveguide 11 and is made of quartz.
Extending toward the end plate 31A of the outer conductor 31 while surrounding the
This extended portion is used as the probe antenna 23a. An ignition electrode 35 connected to an ignition transformer 33 (see FIG. 1) is inserted in the inner tube 25 of the discharge tube 19.
Further, the tip (lower end) of the inner tube 25 is arranged inward by a predetermined distance from the tip of the probe antenna 23a.

Between the cylindrical waveguide 29 and the reaction tube 37,
An optical sensor 39 is provided toward the exposed outer tube 27 as shown in FIG. The optical sensor 39 monitors the plasma generation state by detecting the luminous intensity.

Then, as shown in FIG. 2, the inner conductor 23
The gas supply pipe 41 is provided in the gap between the outer pipe 27 and the base end side of the outer pipe 27.
It is inserted along the tangential direction on the inlet side of the annular passage formed by the outer pipe 27 and the inner pipe 25. Argon gas (rare gas), Freon gas (organic halogen compound), air, and water vapor are supplied to the discharge tube 1 via the gas supply tube 41.
9 to the annular passage. The argon gas, the chlorofluorocarbon gas, and the air are selectively sent to the gas supply pipe 41 from the respective supply sources 43a, 43b, 43c by the opening / closing operation of a solenoid valve (not shown).

Argon gas is supplied to facilitate ignition prior to the generation of plasma, and is stored in the argon cylinder 43a. Needless to say, a rare gas such as helium or neon can be used in addition to the argon gas. Air is supplied from an air compressor (not shown) in order to remove water remaining in the system and improve ignition stability, and to discharge gas remaining in the system. Gas, argon gas or the like is used. The water vapor is necessary for decomposing the fluorocarbon gas, and is generated by sending the water in the water storage tank 43c to a heater (not shown). The chlorofluorocarbon gas is stored in the recovered chlorofluorocarbon cylinder 43b as a liquid and is sent to the gas supply pipe 41 by the opening / closing operation of a solenoid valve (not shown).

As shown in FIG. 2, the reaction tube 37 for decomposing the organohalogen compound at a high temperature and flowing it down as a decomposition gas is connected to a lower end 37a of the reaction tube 37 with a starting end 45a and an end 45b (see FIG. Blowing pipe 45 for dipping decomposition gas into alkaline solution by immersing (see 1) in alkaline solution
Is provided. As shown in FIG. 3, the inner diameter D1 of the blow tube 45 is smaller than the inner diameter D2 of the reaction tube 37. A curved surface 51 is provided at the start end 45a of the blow pipe 45 so that the inner wall surface 37b of the reaction pipe 37 and the inner wall surface 45c of the blow pipe 45 are continuous with each other and project inward.

A metal material (for example, Inconel) is used for the reaction tube 37 to enhance heat resistance, and a resin material is used for the blow tube 45 to enhance corrosion resistance. By making the inner diameter D2 of the reaction tube 37 larger than that of the blow tube 45,
Decrease the flow rate of the hot decomposition gas to increase the residence time,
Improves disassembly performance. On the other hand, the blow-in pipe 45 has an inner diameter D1 smaller than that of the reaction pipe 37 to increase the flow rate of the high-temperature decomposition gas, shorten the residence time, and suppress the production of dioxins and the like.

The exhaust gas treatment tank 53 is provided to neutralize and detoxify the acidic gas (hydrogen fluoride and hydrogen chloride) generated when the CFC gas is decomposed and blown out from the blowing pipe 45. As a neutralization treatment liquid, an alkaline suspension (hereinafter simply referred to as an alkaline liquid) in which calcium hydroxide is added to water 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 neutralized 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 generated by the decomposition reaction of the equation 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 equation 2 are exhaust ducts 55 connected above the exhaust gas treatment tank 53. Is discharged from the system by the blower 57.

From the tip (lower end) of the blow-in pipe 45, the gas produced by the decomposition reaction of the formula 1 is released as bubbles in the alkaline solution. The larger the contact area with the bubbles and the longer the time until the bubbles reach the liquid surface, the more the bubbles are promoted. Therefore, in the exhaust gas treatment tank 53, the bubbles that accelerate the neutralization reaction of Formula 2 by finely dividing the bubbles. A dividing means 59 is provided.

The bubble dividing means 59 is provided with six blades 59b which are rotationally driven by a motor 59a. The bubble dividing means 59 is arranged such that the blade 59b is located above the tip of the blow tube 45, and the bubbles floating from the tip of the blow tube 45 hit the blade 59b 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 59 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 53. Bubble cutting means 59
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 53 has a pH of
A sensor 61 is provided. The pH value of alkaline solution is
It is constantly monitored by a control device (not shown) via the pH sensor 61. 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 and the disassembly operation is performed. Is supposed to stop. As the alarm means, any means can be used as long as it can draw attention to the surroundings, and for example, a 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 53 is provided with a cooler 63 for cooling the alkaline liquid. This cooler 63
The exhaust gas treatment tank 53 is provided with a pump 65 for taking out the alkaline liquid from the bottom and a cooling tube (not shown) that is cooled when the alkaline liquid passes through. The alkali liquid cooled by passing through the cooling tube is returned to the exhaust gas treatment tank 53 again. By the way, the temperature inside the tank is detected by the thermocouple 67.

A three-way valve 69 is provided on the downstream side of the cooler 63. By switching the three-way valve 69, an alkaline liquid containing a slurry as a processing liquid can be sent to the settling tank 71. . A stirrer 73 is provided inside the settling tank 71 so that a coagulant is added to the treatment liquid to cause coagulation and then solid-liquid separation is performed by a dehydration basket 75 provided below the settling tank 71. ing.

A procedure for decomposing freon in the decomposition apparatus for an organic halogen compound having the above-mentioned structure will be described. First, air from an air compressor (not shown) is supplied to the discharge tube 19 via the gas supply tube 41. When this air passes through a heater (not shown), 100-
It is heated to 180 ° C. For this reason, the residual moisture in the device is surely removed, and the stability of ignition is improved.

Then, an electromagnetic valve (not shown) is closed and argon gas is supplied to the discharge tube 19. At this time, since the argon gas is supplied from the tangential direction of the outer tube 27 and flows down in a spiral shape, stagnation is formed near the tip of the inner tube 25, and plasma is easily retained.

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 19 is less susceptible to the thermal influence of plasma, and its melt deformation and damage are effectively prevented. Become.

Then, the microwave is emitted from the microwave transmitter 13 at a constant interval from the start of the supply of the argon gas. The microwave is transmitted to the rear end side of the rectangular waveguide 11 and further to the cylindrical waveguide 29.

At this time, as the electric field in the cylindrical waveguide 29, the TM01 mode having a large electric field strength is formed, and further, the inner conductor 23 causes the electric field mode in the rectangular waveguide 11 and the cylindrical waveguide 29. Since the electric field mode inside is coupled, the electric field inside the cylindrical waveguide 29 is stable. Naturally, the magnetic field is generated in the direction orthogonal to the electrolysis. The gas introduced into the discharge tube 19 is heated to a plasma state by the vibrating electromagnetic field.

Next, a high voltage is applied to the ignition electrode 35 connected to the ignition transformer 33 to generate a spark discharge between itself and the inner conductor 23 to ignite it. At this time, the interior of the discharge tube 19 is easily ignited because the moisture is removed by the air and the argon gas which is easy to ignite is supplied in advance. Next, water is sucked from the water storage tank 43c and passed through a heater (not shown) to generate water vapor.
Supply to 9.

After the supply of the steam is started, the supply of the CFC gas is started as described later. The reason for supplying the steam first is that when only the CFC gas is turned into plasma, an unexpected harmful effect is caused by the recombination of dissociated atoms. This is because such a halogen compound is generated and it becomes impossible to perform detoxification treatment. Therefore, as described above, the steam can be safely decomposed by supplying the steam to the discharge tube 19 and then supplying the CFC gas so that the steam exists during the CFC decomposition.

Next, CFC gas is supplied to the discharge tube 19. At this time, the freon gas flowing out from the recovered freon cylinder 43b passes through a mist separator (not shown) to remove oil and water. 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.

When the CFC gas supplied to the discharge tube 19 is irradiated with microwaves in this manner, the electron energy in the discharge tube 19 is high and the temperature is 2,000K.
Thermal plasma increased to ~ 6,000K is generated. At this time, since not only the CFC gas and the water vapor but also the argon gas are simultaneously supplied to the discharge tube 19, the plasma is not lost.

Further, since the tip of the inner tube 25 is disposed inward of the tip of the probe antenna 23a by a predetermined distance, the thermal influence of the generated plasma can be avoided, and the inner tube 25 can be prevented. Melt damage 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. Then, when the plasma is stabilized, the supply of argon gas is stopped. Therefore, when the CFC gas is decomposed over a long period of time, it is not necessary to supply argon, and the amount of argon consumption can be kept low.

The gas produced by the decomposition reaction flows from the lower end 37a of the reaction tube 37 into the starting end 45a of the blow pipe 45, passes through the blow pipe 45 and is discharged into the alkaline liquid in the exhaust gas treatment tank 53. At this time, as shown in FIG. 3, the high-temperature generated gas is guided by streamlines from the inner wall surface 37b of the reaction tube 37 to the inner wall surface 45c along the curved surface 51, and is separated at the inner wall surface 45c of the blow tube 45. Does not redeposit.

The product gas released into the alkaline solution through the blow pipe 45 is rendered harmless by the neutralization reaction of 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 63. That is, the alkaline liquid in the exhaust gas treatment tank 53 is sucked out of the tank by the pump 65, flows in the cooling tube of the cooler 63, is cooled, and is returned to the exhaust gas treatment tank 53 again.

The produced gas released as bubbles from the tip of the blow-in pipe 45 is the blade 59 of the bubble cutting means 59.
Since it is finely divided by hitting b, 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 55, and the gas other than the gas remains as a slurry in the alkaline liquid. After the decomposition operation is stopped, the bubble dividing means 59 is stopped, and then the treatment liquid is pumped up by the pump 65, the three-way valve 69 is switched, and this is transferred to the settling tank 71. The aggregating agent is uniformly added while stirring the treatment liquid transferred to the settling tank 71 with the stirrer 73, and the stirrer 73 is stopped to cause precipitation, and then solid-liquid separation is performed in the dehydration basket 75, and the liquid component is treated as wastewater. However, the solid content is discarded.

As described above, in the organohalogen compound decomposing apparatus of the present embodiment, the start end 45a of the blow pipe 45 is formed.
Corner portion 7 when a tapered surface that linearly reduces in diameter is formed
(See FIG. 6) disappears, and the high-temperature generated gas flows along the curved surface 51. Therefore, phenomena such as peeling and redeposition of flowing high-temperature gas can be suppressed. As a result, the inner wall surface 45c of the blow pipe 45 is prevented from reaching a high temperature due to high heat transfer, and even if the blow pipe 45 is made of a resin material, melting damage does not occur. Moreover, the existing reaction tube 37 can be used.

Next, a second embodiment of the organic halogen compound decomposing apparatus according to the present invention will be described. FIG. 4 is an enlarged cross-sectional view showing the connecting portion between the reaction tube and the blow tube in the second embodiment only on one side from the axis. The same members as those shown in FIGS. 1 to 3 are designated by the same reference numerals, and duplicate explanations will be omitted. The apparatus for decomposing an organohalogen compound according to this embodiment has an inner wall surface 81a at the lower end of the reaction tube 81, and an inner wall surface 81a is bulged along a streamline of the decomposition gas so that the inner wall surface 81a of the reaction tube 81 and a blow tube A bulging curved surface 83 that connects the 45 curved surfaces 51 is provided.

According to this apparatus for decomposing organic halogen compounds, separation and reattachment of flowing high temperature gas can be suppressed, the inner wall surface 45c of the blow pipe 45 can be prevented from reaching a high temperature, and the blow pipe 45 made of a resin material can be used. In addition to preventing melting damage even if there is, a bulging curved surface 83 causes a concave portion (a portion surrounded by the bulging curved surface 83 and the broken line in FIG. 4) to be formed at the connecting portion between the lower end of the reaction tube 81 and the curved surface 51. Since it disappears, stagnation of high temperature gas can be prevented and pressure loss can be reduced.

Next, a third embodiment of the organic halogen compound decomposing apparatus according to the present invention will be described. FIG. 5 is an enlarged cross-sectional view showing the connecting portion between the reaction tube and the blowing tube in the third embodiment only on one side from the axis. The apparatus for decomposing organic halogen compounds according to this embodiment is provided with a starting end 9 of a blow pipe 91.
1a is provided with a short tube portion 93 having the same inner diameter as the reaction tube 37,
Between the inner wall surface 93a of the short pipe portion 93 and the inner wall surface 91b of the blow pipe 91, along the stream line of the high temperature gas, the short pipe portion 93 is formed.
A curved surface 95 that connects the inner wall surface 93a of the No. 3 and the inner wall surface 91b of the blow pipe 91 is provided.

According to this organohalogen compound decomposing apparatus, the corner 7 (see FIG. 6) when the taper surface which linearly reduces in diameter is formed at the starting end 91a of the blow-in pipe 91 is eliminated,
The hot gas flows along the inner wall surface 93a of the short pipe portion 93 and the curved surface 95, and it is possible to prevent the flowing hot gas from being separated or reattached. As a result, the inner wall surface 91b of the blow pipe 91 is prevented from reaching a high temperature due to high heat transfer, and even if the blow pipe 91 is made of a resin material, melting damage does not occur. Further, the lower end of the reaction tube 37 and the curved surface 9
The concave portion is eliminated at the connecting portion with 5, and the stagnation of high temperature gas can be prevented. Furthermore, the reaction tube 37 can use the existing one.

[0055]

As described in detail above, according to the organohalogen compound decomposing apparatus of the present invention, the inner wall surface of the reaction tube and the inner wall surface of the blow tube are projected at the beginning of the blow tube so as to project inward. Since a curved surface to be continuous is provided, at the beginning of the blow pipe,
When the tapered surface that linearly reduces the diameter is not formed, the high temperature gas flows along the curved surface, and it is possible to suppress the phenomenon such as separation and reattachment of the flowing high temperature gas.
This prevents the inner wall surface of the blow-in pipe from reaching a high temperature due to high heat transfer, and in particular, even in the case of the blow-in pipe made of a resin material, melting damage does not occur. As a result, the outflow of decomposed gas can be prevented, and the safety and stability of the device can be improved. Further, the existing reaction tube can be used, and the improvement cost can be suppressed.

According to the organic halogen compound decomposing apparatus of the present invention, the inner wall surface of the reaction tube is blown into the inner wall surface of the reaction tube by bulging the inner wall surface along the streamline of the decomposition gas. Since the bulging curved surface that is continuous with the curved surface of the pipe is provided, it is possible to suppress the separation and re-adhesion of the flowing hot gas, prevent the inner wall surface of the blowing pipe from becoming hot, and especially the blowing pipe made of a resin material. However, melting damage does not occur. In addition to this, since the bulging curved surface eliminates a concave portion at the connecting portion between the lower end of the reaction tube and the curved surface, stagnation of high temperature gas can be prevented and pressure loss can be reduced.

Further, according to the organohalogen compound decomposing apparatus of the present invention, a short tube portion having the same inner diameter as that of the reaction tube is provided at the start end of the blow tube, and the inner wall surface of this short tube portion and the inner wall surface of the blow tube. Since a curved surface that connects the inner wall surface of the short pipe portion and the inner wall surface of the blow pipe along the streamline of the cracked gas is provided between the and, a tapered surface that linearly reduces in diameter is provided at the start end of the blow pipe. The corners when formed are eliminated, and the phenomenon in which the hot gas flows along the curved surface and the flowing hot gas is separated or redeposited can be suppressed. This prevents the inner wall surface of the blow-in pipe from reaching a high temperature due to high heat transfer, and in particular, even in the case of the blow-in pipe made of a resin material, melting damage does not occur. As a result, the outflow of decomposed gas can be prevented, and the safety and stability of the device can be improved. Further, since the concave portion is eliminated at the connecting portion between the lower end of the reaction tube and the curved surface, stagnation of high temperature gas can be prevented. Furthermore, the existing reaction tube can be used, and the improvement cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of an organohalogen compound decomposing apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing portions of a reaction tube and a blow tube shown in FIG.

FIG. 3 is an enlarged cross-sectional view showing a connection portion between a reaction tube and a blow tube on only one side from an axis.

FIG. 4 is an enlarged cross-sectional view showing a connection portion between a reaction tube and a blow tube in the second embodiment on only one side from an axis.

FIG. 5 is an enlarged cross-sectional view showing a connecting portion between a reaction tube and a blowing tube in the third embodiment only on one side from an axis.

FIG. 6 is an enlarged cross-sectional view showing a connection portion between a conventional reaction tube and a blow tube on only one side from an axis.

[Explanation of symbols]

37, 81 ... Reaction tube 37a ... lower end 45, 91 ... Blown pipe 45a ... starting point 45b ... Termination 51 ... Curved surface 83 ... Swelling curved surface 93 ... Short pipe part 95 ... Curved surface

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07B 37/06 C07C 19/10 C07C 19/10 B01D 53/34 134E (72) Inventor Soichiro Matsumoto Nishi Kasugai Gunma Nishibiwajima-cho, Asahi-cho 3-chome 1 Mitsubishi Heavy Industries, Ltd. Cooling & Heat Business Headquarters (72) Inventor Takataka Hasegawa 1 at 60 Kyutansho, Iwatsuka-cho, Nakamura-ku, Aichi Prefecture Nakabishi Engineering Co., Ltd. Term (reference) 4D002 AA21 AC10 BA02 BA07 CA06 DA01 EA02 HA03 4G075 AA03 AA13 AA53 BA05 BD12 BD13 BD27 CA02 CA48 DA01 EA01 EB22 EB43 EC01 EC06 FB02 FC06 FC09 4H006 AA05 AC13 AC26 BA95

Claims (3)

[Claims] 1. A reaction tube for decomposing an organohalogen compound into a decomposition gas at a high temperature and flowing it down, and a starting end is connected to a lower end of the reaction tube and an end thereof is immersed in an alkali solution to decompose the decomposition gas into the alkali solution. In an organohalogen compound decomposing device having a blow-in pipe blown into it, wherein the inner diameter of the blow-in pipe is smaller than the inner diameter of the reaction pipe, at the starting end of the blow-in pipe, the inner wall surface of the reaction pipe is projected inward in the pipe. An organohalogen compound decomposing apparatus having a curved surface continuous with the inner wall surface of the blow pipe. 2. The organohalogen compound decomposing apparatus according to claim 1, wherein the inner wall surface of the lower end of the reaction tube is swollen along the streamline of the decomposition gas so as to swell the inner wall surface of the reaction tube. An apparatus for decomposing an organohalogen compound, characterized in that a bulging curved surface which connects the curved surface of the blow tube with the curved surface of the blowing tube is provided. 3. A reaction tube for decomposing an organohalogen compound into a decomposed gas at a high temperature and flowing it down, and a starting end connected to the lower end of the reaction tube and a terminal end immersed in an alkali solution to decompose the decomposed gas into the alkali solution. In an organohalogen compound decomposing apparatus having a blow-in pipe blown into it, wherein the inner diameter of the blow-in pipe is smaller than the inner diameter of the reaction pipe, a short pipe portion having the same inner diameter as the reaction pipe is provided at the starting end of the blow-in pipe. Provided between the inner wall surface of the short pipe portion and the inner wall surface of the blow pipe is a curved surface that connects the inner wall surface of the short pipe portion and the inner wall surface of the blow pipe along the streamline of the decomposed gas. An organic halogen compound decomposing device characterized by the above.