JPH0623222A - Method and apparatus for treating waste gas - Google Patents

Abstract

PURPOSE:To effectively treat waste gas to the high concentration with compact equipment by mixing gas to be treated and a powder adsorbent to give sticking/ adsorption before performing low temperature heating treatment, high temperature heating treatment and harm removing treatment. CONSTITUTION:While gas to be treated 8 contg. mist, high boiling substances and harmful/odorous gas is mixed with a powder's adsorbent and the mixture is pneumatically carried, the mist and the high boiling substances are stuck to the adsorbent and the harmful/odorous gas is adsorbed onto the adsorbent. Next, the adsorbent is removed from the flow of the gas to be treated by a cyclone 14A and carried pneumatically to reach a low temperature heating means 3 where the harmful/odorous gas is desorbed and the mist and the high boiling substances remain stuck. Further, the adsorbent is transferred to the high temperature heating means 9 to thermally decompose the mist and the high boiling substances and the regenerated adsorbent is circulated by a feed means 5. As a result, the withdrawn waste gas is made harmless.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a low concentration exhaust gas containing sticky dust and harmful / malodorous gas such as automobile coating exhaust gas, a plasticizer generated in a printing process, a steel pipe manufacturing process, etc.
When processing low-concentration exhaust gas containing high-boiling substances, mist and harmful / malodorous gas, which deteriorates adsorbents such as higher fatty acids, oil fumes, and pitches, mist and high-boiling substance and harmful / malodorous gas are simultaneously processed, Further, the present invention relates to an exhaust gas treatment method for separating harmful / odorous gas components and concentrating them into a small amount of air for efficient treatment, and an exhaust gas treatment apparatus suitable for carrying out the method.

[0002]

2. Description of the Related Art As an apparatus for treating this kind of exhaust gas, a solvent recovery apparatus utilizing an adsorbent such as activated carbon, a honeycomb type concentration apparatus, and a catalytic oxidation apparatus have been generally used. High-boiling substances require an expensive pretreatment device to adhere to and deteriorate the adsorbents and catalysts.Electric precipitators, adsorption layers, etc. are provided as pretreatment devices to remove dust or remove high-boiling substances. Is being done.

[0003]

The electrostatic precipitator and the adsorbent layer have to be subjected to a cleaning process such as cleaning each time the adhered amount increases, which poses a management problem. In many cases, a furnace is used together, but this requires a huge amount of fuel cost and causes a problem of high operating cost.

The above-mentioned conventional exhaust gas treating apparatus has a drawback that the economical efficiency becomes low as the concentration becomes low. Therefore, the exhaust gas treating apparatus is once concentrated to reduce the air volume, and is treated in combination with a small treating apparatus. The device that is in the limelight is
This is a concentrating device using a rotor in which an adsorbent such as activated carbon is processed into a honeycomb shape. This device has the advantage of being excellent in operating economy, but has the following problems.

Since the adsorbent is processed into a honeycomb rotor, the cost of the apparatus is more than ten times higher than that of the raw adsorbent, and the adsorbent is mixed with the organic binder and auxiliary materials for molding. When the adsorption performance is deteriorated, it is difficult to regenerate, and since the heating method using the hot air for regeneration cannot perform indirect heating, the enrichment is limited to 10 to 15 times in terms of the heating heat amount of the honeycomb rotor. The problem is that not only the adsorbent but also other combination members such as auxiliary materials must be heated at the same time, which requires a large amount of heating.

In the case of treating automobile exhaust gas, since the adhesive dust is contained in the exhaust gas, the adhesive dust adheres to the surface of the honeycomb rotor and clogs it, resulting in extremely low adsorption performance. Therefore, it is necessary to combine it with a high-performance and expensive wet electrostatic precipitator, which raises the problem of increasing the total equipment cost.

On the other hand, in the case of the printing exhaust gas, a high boiling point substance such as a plasticizer and a wood tar component is contained, which deteriorates the adsorbent of the honeycomb rotor. It became necessary to combine an electrostatic precipitator,
Similarly, there is a problem that the equipment cost is high.

The object of the present invention is to enable removal of harmful / odorous gas components in the gas to be treated by efficient adsorption and removal of mist and high boiling point substances by thermal decomposition during air flow transportation, and Easy to use flow rate regeneration gas,
It is an object of the present invention to provide an exhaust gas treatment method and device which can perform highly reliable and highly concentrated exhaust gas treatment at a low operating cost by adopting a structure capable of sure desorption.

[0009]

According to the present invention, a powdery adsorbent is mixed with a gas to be treated containing a mist, a high-boiling substance, and a harmful / malodorous gas to adsorb the harmful / malodorous gas to the adsorbent. After adsorbing the mist and the high-boiling-point substance to the adsorbent, the adsorbent that has been adsorbed and adhered is brought into contact with a desorbable gas in a low temperature range to remove the adsorbed harmful / odorous gas. Desorption, after that, by contacting with a gas in a high temperature range to thermally decompose the attached mist and high boiling point substances, desorption, the gas component generated by thermal decomposition is separated from the powdery adsorbent, In addition, the exhaust gas treatment method is characterized in that the recovered or detoxified treatment is performed, and the regenerated powdery adsorbent is returned and mixed with the gas to be treated.

Further, according to the present invention, an adsorbing airflow conveying means for admixing and adsorbing while admixing a powdery adsorbent with a gas to be treated containing a mist, a high-boiling substance, and a harmful / odorous gas, and adhering to the adsorbent. And a separating means for separating the adsorbent from the gas to be treated containing the powdery adsorbent from the adsorbing airflow conveying means, and the adsorbent separated by the separating means and the gas in the low temperature region are mixed. To remove the harmful / malodorous gas and to separate the desorbed harmful / malodorous gas from the adsorbent, and the adsorbent and the gas in the high temperature range separated by the low-temperature heat treating means. Mix
High-temperature heat treatment means for thermally decomposing mist and high-boiling-point substances adhering to the adsorbent and separating the gas and adsorbent generated by this pyrolysis, and adsorption after regeneration separated by the high-temperature heat treatment means. Adsorbent supply means for cooling the agent and supplying it to the adsorption air flow conveying means, and detoxification treatment for detoxifying the harmful / malodorous gas separated by the low temperature heat treatment and the gas separated by the high temperature heat treatment means An exhaust gas treatment apparatus comprising a treatment means.

Further, the present invention is an exhaust gas treating apparatus in which the low-temperature heat treatment means and the high-temperature heat treatment means include an air flow carrying means, a cyclone, and a bag filter, which are sequentially connected in series. is there.

Further, in the present invention, the detoxification processing means is an oxidative decomposition apparatus which performs a combustion action, and the high temperature gas generated in the oxidative decomposition apparatus is a low temperature range gas of the low temperature heat processing means and a high temperature heat processing means. It is an exhaust gas treatment device used for high temperature range gas.

Further, in the present invention, the adsorbent supply means is a cooling device including an air flow carrying means for using atmospheric air as a carrier air flow, a cyclone separator, and a bag filter, and an adsorbent after regeneration with the air as a carrier air stream. It is an exhaust gas treatment apparatus provided with an air flow carrier for mixing with a treatment gas.

[0014]

According to the present invention, the gas to be treated and the adsorbent in the form of powder are mixed in the process of air flow conveyance to adsorb harmful or malodorous gas in direct contact with each other and to mist or high boiling point substances. Adhesion is done. Therefore, the adsorption process is performed with a simple structure of the air flow transfer path, and a device having a complicated mechanism such as a honeycomb type concentrating device can be omitted.

The adsorbent that has been adsorbed and adhered is separated from the gas to be treated by a separating means such as a cyclone separator or a bag filter, and then desorbed, separated and pyrolyzed by the low temperature heat treatment means and the high temperature heat treatment means. And the separation is performed, and the regenerated adsorbent after being treated by both heat treatment means is mixed with the gas to be treated and reused for the exhaust gas treatment.

In the case of regenerating the desorbent, the regeneration temperature conditions are different between the harmful / malodorous gas and the mist or high boiling point substance.
The regeneration temperature condition for desorption of harmful / odorous gas is 120.
~ 250 [deg.] C, under which temperature the desorbent is desorbed from the adsorbent. On the other hand, mist such as paint mist requires oxidative decomposition in addition to thermal decomposition, and the decomposition becomes remarkable from about 250 ° C., but a high temperature of 350 to 600 ° C. is necessary for complete decomposition. High-boiling substances vary depending on the type of substance,
Desorption is carried out at a temperature of 250 ° C to 350 ° C, and part of it is thermally decomposed to produce tar and carbon, and 350 to 600 ° C is required as a regeneration condition including these.

The reason why the low temperature heat treatment is necessary is as described below. When heat treatment is performed under the conditions of regeneration of mist and high boiling point substances, harmful / malodorous gas is also desorbed at the same time, but it is within the ignition temperature range of harmful / malodorous gas, harmful / malodorous gas ignites, and becomes high concentration by concentration. From this point, the temperature rise due to the combustion heat becomes high, and trouble may occur due to abnormal temperature rise in the regeneration processing section.
For another reason, when collecting harmful / odorous gas,
The low-temperature heat treatment has a lower degree of decomposition, has a high purity and can be recovered as a liquid, and further has a low content of a high-boiling substance and other impurities.

The low-temperature heat treatment and the high-temperature heat treatment can be performed with a rotary kiln, a ribbon mixer or the like. Preferably, hot air can be used to uniformly heat by an air flow heating method, and a high temperature gas of a catalytic oxidation device in a subsequent step or an oxidative decomposition device such as a direct combustion furnace can be used as a heat source, which is economical. The amount of hot air used for low-temperature heat treatment is sufficiently smaller than the amount of gas to be treated, and the harmful / malodorous gas in the gas to be treated is transferred into this hot air, so that the ratio of the amount of gas to be treated to the amount of hot air is harmful / The malodorous gas will be concentrated.

After the low temperature heat treatment, the adsorbent is heated to 350 ° C. or higher, and the mist and high-boiling substances are removed by thermal decomposition and oxidative decomposition. This apparatus also utilizes the exhaust gas from the oxidative decomposition apparatus, and it is economical to heat with a high-temperature air stream, which is preferable as a uniform continuous treatment.

As a device for producing a heating gas for mixing with the adsorbent in the low / high temperature heat treatment means,
It can be constituted by an air carrying path, a cyclone, a bag filter, etc., and the adsorbent is effectively heat-treated between the air carrying path and the cyclone. Depending on the properties of the mist and the high-boiling substance, it may be necessary to retain the adsorbent separated by the cyclone or the bag filter in a rotary kiln or a ribbon mixer under a high temperature for a certain period of time.

When the concentrated gas after the low temperature heat treatment is to be recovered, it is sent to and recovered by a small-sized solvent recovery device corresponding to this concentrated gas air volume. When detoxifying by oxidative decomposition, it is sent to the oxidative decomposing device together with the exhaust gas after high-temperature heat treatment to be detoxified.

After the high temperature heat treatment, the adsorbent is cooled and returned to the adsorbing airflow conveying means in the first step. However, depending on the type of the substance in the gas to be treated, the malodorous component generated during the decomposition remains. However, this malodorous component may contaminate the purified gas used for the adsorption carrier flow. Therefore, by using an air flow carrier that uses the atmosphere as a carrier air flow as a cooling unit, and a cooling device that includes a cyclone separator and a bag filter, and separating the adsorbent from the cooling air, the adsorbent is cooled. At the same time, there is an advantage that the malodorous components that accompany the adsorbent are removed from the cooling air. Comparing the same cooling air amount, it is preferable that the cooling means adopts a multi-stage system because cooling and removal of malodorous components are performed more efficiently.

The adsorbent used in the method and apparatus of the present invention is required to be a nonflammable material, and zeolite, silica gel, sepiolite or the like can be applied, but hydrophobic zeolite has a low hygroscopic property, It is a suitable adsorbent because it has a large amount of harmful / odorous gas adsorption and good heat resistance. An example thereof is a hydrophobic zeolite having a particle diameter of 300 μm or less, preferably 100 μm or less as a main component. This hydrophobic zeolite is an excellent adsorbent for polar odors such as organic solvents, ammonia, amines, and mercaptans, chemically aluminosilicate metal salt crystals, and adsorbs many malodorous components as an adsorbent. It has the property of collecting.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram of an exhaust gas treating apparatus which is an embodiment of the present invention. The apparatus shown in FIG. 1 comprises an adsorption air flow transfer means 1, a separation means 2, a low temperature heat treatment means 3,
The high-temperature heat treatment means 4, the adsorbent supply means 5, and the detoxification treatment means realized by the first treatment means 6 and the second treatment means 7 are provided.

The adsorbing airflow conveying means 1 has first and second adsorbent nozzles 13A and 13B provided in the middle thereof, and gas lines 9A and 9B through which a treated gas 8 such as coating exhaust gas flows. And a conduit 12A provided with a blower 11A
And a first air flow transport path 10A having the element as a component member.
The gas to be treated 8 is conveyed by air flow and is transferred to the first adsorbent nozzle 1
3A mixes with the powdery adsorbent ejected into the gas pipe 9A and flows to the downstream gas pipe 9B, further mixes with the adsorbent ejected from the second adsorbent nozzle 13B, and the downstream side Flow to. The gas to be treated 8 containing the mist, the high-boiling substance, and the harmful / malodorous gas is mixed with an adsorbent such as a powdery hydrophobic zeolite, and the mist and the high-boiling substance are attached to the hydrophobic zeolite while being conveyed by air flow. Hazardous / odorous gas is adsorbed.

The separating means 2 comprises a first cyclone 14A,
A first bag filter 15A, a first receiver 16A,
It is equipped with two screw feeders 17A and 17B.

In the first cyclone 14A, the gas pipeline 9B is concentrically provided as an exhaust inner cylinder at the center of the cylindrical main body, and the gas pipeline 9 is provided above the cylindrical wall of the main body.
The outlet end of A is connected and an outlet with a rotary valve 20 is provided on the bottom wall of the body. The first bag filter 15A is divided into two chambers, an upper chamber and a lower chamber, by a filter 18 composed of a plurality of bag-shaped cloths, and an exhaust port 19 is opened at the top wall of the upper chamber, The outlet end of the gas line 9B is connected to the upper portion of the side wall of the chamber, and the outlet having the rotary valve 21A is provided on the bottom wall of the lower chamber.

The first receiver 16A includes the first cyclone 1
4A and the first bag filter 15A, the rotary valves 20, 21A are provided on the top wall of the main body container.
Conduits respectively extending from the bottom wall are provided with an outlet. The screw feeders 17A and 17B are provided with a supply port and a discharge port in a main body in which a screw is rotatably housed, and each supply port is a receiver 16A through a pipe line.
Connected to the outlets of the rotary valves 2
The pipes having 2A and 22B are branched and connected in the middle of the pipe 12A and in the middle of the pipe 12B described later.

Each rotary valve 20, 21A, 22A,
B is a feeder having the same structure, having a rotor in which the tips of the blades are in close contact with the main body case and rotating about a horizontal axis, and which receives powder between the blades by gravity and can supply it while sealing it, It is possible to replace and use the rotary feeder or the lock hopper which has the same effect as this. When the receiver 16A has an airtight structure, either of the rotary valves 20 and 21A can be omitted.

The operation mode of the separating means 2 is as follows. The airflow flowing in the gas pipe 9A, that is, the gas to be treated 8 mixed with the powdery adsorbent, flows into the main body of the first cyclone 14A in the tangential direction of the cylindrical wall and swirls along the inner wall of the cylinder. While descending, centrifugal force acts on the adsorbent adsorbed and adhered during this time, the adsorbent moves in the wall direction, and is separated from the to-be-processed gas 8 which has been cleaned to some extent as an air flow. And falls down the wall. On the other hand, the gas to be treated 8 separated from the adsorbent flows into the gas pipe 9B from the lower end and is mixed with the regenerated adsorbent ejected from the adsorbent nozzle 13B, and then from the upper end to the first bag filter 15A. Is sent to the lower chamber. The adsorbent that has dropped downward is in a state of having a surplus of suction and adhesion, and is fed to the first receiver 16A while the supply amount is adjusted by the rotary valve 20. The gas to be processed 8 into which the air flow sent into the lower chamber of the first bag filter 15A, that is, the adsorbent that has not been completely removed is mixed.
The mist and high-boiling-point substances are attached, and the harmful / foul-smelling gas component is scraped off by applying a reverse pressure after the adsorbent that has been adsorbed is collected by the filter 18, and falls to the bottom. The processed gas 8 that has been cleaned passes through the filter 18 and is discharged into the atmosphere through the exhaust port 19 or is collected.

The powdery adsorbent that has dropped to the bottom is sent to the first receiver 16A by the rotary valve 21A, and is mixed with the adsorbent sent through the rotary valve 20 in the first receiver 16. The adsorbent staying in the first receiver 16A is the screw feeder 17A,
17B, the rotary valves 22A, 22
After being sent out quantitatively by B, one of
The air is mixed with the air flowing in A and is conveyed by air, and the other is mixed with the hot air flowing in a pipe 12B described later and conveyed by air. In this way, the separating means 2 separates the adsorbent in the mixed state from the adsorption airflow conveying means 1 and the gas to be treated, and most of the adsorbent is fed to the next low temperature heat treating means 3, A part of them is returned to the suction air flow transport means 1 in order to perform suction / adhesion.

The low-temperature heat treatment means 3 includes a second air current carrying passage 10B having a pipe 12B in the middle of which a blower 11B is provided as an element member, a second cyclone 14B, a second bag filter 15B and a second receiver. 16B and. The conduit 12B in the second airflow transport path 10B has an inlet end
The blower 1 is connected to a pipe line 24 through which high-temperature hot air is circulated.
The midway of the pipe line near the suction side of 1B is connected to the pipe line 25 for circulating the normal temperature air flow, and the outlet side end part is the second cyclone 1
4B is connected to the upper part of the cylindrical wall of the body. In addition, pipeline 25
A temperature control valve 27 is provided in the. Second cyclone 14
B, second bag filter 15B and second receiver 16
Regarding B, the first cyclone 14 in the separating means 2
A, first bag filter 15A and first receiver 16
Since it is the same as B in terms of structure and connection form between them, detailed description thereof is omitted. The second receiver 1
The rotary valve 23B at the outlet of 6B is connected by a pipe in the middle of a pipe 12C through which high-temperature hot air described later flows.

The operation mode of the low-temperature heat treatment means 3 is as follows. The adsorbent, which is sent out in a fixed amount from the screw conveyor 17B and which is sufficiently adhered and adsorbed, flows in the pipe line 12B of the second air flow transfer passage 10B while being kept at a constant temperature by the temperature adjusting action of the temperature adjusting valve 27. When mixed with a low temperature, for example, 300 ° C air flow,
It becomes a gas stream under a solid / gas mixture state in which the temperature has dropped to 0 ° C. and flows into the second cyclone 14B. 20 in pipeline 12B
The adsorbent heated to about 0 ° C. releases (desorbs) the adsorbed harmful / bad odor gas. On the other hand, the attached mist,
The high-boiling substance remains attached because it is at a temperature (400 to 500 ° C.) below which it is thermally decomposed. In this case, the airflow in the conduit 12B required for desorption is ³ to 10 with respect to the flow rate of the gas to be treated 8 flowing in the gas conduit 9A, 100 m ³ / hour.
Since a small air flow of about m ³ / hour is sufficient and the desorption treatment means 3 is in a highly concentrated state, the second
The low temperature superheat treatment means 13 including the bag filter 15B can be performed by a small-scale facility.

The adsorbent, which is separated from the exhaust gas concentrated in the second cyclone 14B and drops downward, is sent to the second receiver 16B. On the other hand, the highly concentrated exhaust gas separated from the adsorbent is sent to the lower chamber of the second bag filter 15B, the remaining adsorbent is separated from the highly concentrated exhaust gas, and the adsorbent dropped downward is the rotary valve 21B. Is fed into the second receiver 16B through the filter 18
The highly concentrated exhaust gas that has passed through is sent to the first processing means 6 described later from the exhaust port 19 provided in the top wall of the upper chamber.

The adsorbent stored in the second receiver 16B is sent out by the rotary valve 23B in a state where mist and high boiling point substances are attached, and the hot air flow flowing in the pipe 12C of the third air flow transfer passage 10C described later. It is mixed in and transported by air flow. In this way, in the low-temperature heat treatment means 3, the adsorbent fed from the separation means 2 is fed to 120 to 25
The harmful / malodorous gas is desorbed by heating to a low temperature in the range of 0 ° C., the desorbed harmful / malodorous gas is separated from the adsorbent, and the adsorbent is sent to the next high-temperature heat treatment means 4 to remove harmful / malodorous gas.
The malodorous gas is sent to the first processing means 6.

The high-temperature heat treatment means 4 includes a third air current carrying passage 10C having a pipe 12C in the middle of which a blower 11C is provided as an element member, a third cyclone 14C, a third bag filter 15C, and a third bag filter 15C. With receiver 16C,
They correspond to the second air current carrying path 10B, the second cyclone 13C, the second bag filter 15B, and the second receiver 16B in the low-temperature superheat treatment means 3, and are equivalent in terms of structure and connection form. , Detailed description is omitted.

The mode of operation of the high temperature heat treatment means 4 will be described. The adsorbent that is sent out from the second receiver 16B in a fixed amount has mist and a high boiling point substance attached,
This adsorbent is mixed with an air stream of a high temperature, for example 600 ° C., flowing in the conduit 12C of the third air stream transport path 10C, and 350
Heat to ~ 500 ° C. The hot air flow in the pipe 12C is
For a high temperature air flow of about 800 ° C flowing in the pipe 24,
A constant temperature is maintained by mixing the air streams in the conduit 26 whose temperature is regulated by the temperature regulating valve 28. The air flow in the solid / gas mixture state in which the adsorbent is mixed and flows in the pipe 12C is sent to the third cyclone 14C,
The mist and high-boiling-point substances adhering to the adsorbent are supplied to the conduit 12
The adsorbent is regenerated by being thermally decomposed in C and in the third cyclone 14C at a high temperature and separated from the adsorbent. Most of the regenerated adsorbent is separated by the third cyclone 14C and sent to the third receiver 16C from the bottom. On the other hand, the exhaust gas separated from the adsorbent is sent to the lower chamber of the third bag filter 15C to completely separate the adsorbent that has not been completely removed from the exhaust gas, and the regenerated adsorbent that has dropped down is the rotary adsorbent. Via valve 21C,
It is sent into the third receiver 16C. The exhaust gas that has passed through the filter 18 in the bag filter 15C is sent to the second processing unit 7 described later from the exhaust port 19 provided on the top wall of the upper chamber.

The adsorbent accumulated in the third receiver 16C is in a completely regenerated state, is sent out by the rotary valve 23C, and is a pipe of the fourth air flow transfer passage 10D in the adsorbent supply means 5 described later. It is mixed with the atmosphere flowing in the path 12D and is conveyed by air flow. In this way, in the high-temperature heat treatment means 4, the adsorbent fed from the low-temperature heat treatment means 3 is heated to a high temperature in the range of 350 to 600 ° C., and the attached mist or high boiling point substance is thermally decomposed and released. Then, the regenerated adsorbent is sent to the next adsorbent supply means 5, and the exhaust gas generated by thermal decomposition is sent to the second treatment means 7.

The adsorbent supply means 5 has a fourth air flow transfer passage 10 having a pipe 12D provided with a blower 11D as an element member.
D, the fourth cyclone 14D, and the fourth bag filter 1
5D, the 4th receiver 16D, and the 5th air current conveyance path 10E which uses the conduit 12E in which the blower 11E is provided as an element member.
With. The fourth airflow transfer path 10D, the fourth cyclone 14D, the fourth bag filter 15D, and the fourth receiver 16D include a second airflow transfer path 10B, a second cyclone 14B, and a second cyclone 14B in the low-temperature heat treatment means 3. It corresponds to the bag filter 15B and the second receiver 16B,
Since the carrier flow is the same in terms of structure and connection except that it is the atmosphere, detailed description will be omitted. 4th and 5th
Both air flow passages 10D and 10E are blowers 11D and 11E.
By using the normal temperature atmosphere sent by
The outlet side end portion of the pipe 12E in the fifth air flow carrying passage 10E is provided with the adsorbent nozzle 1 provided in the gas pipe 9B.
3B is connected.

The mode of operation of the adsorbent supply means 5 will be described. From the third receiver 16C to the rotary valve 2
The regenerated adsorbent in the high temperature state sent out through 3C is mixed with the room temperature air flowing in the pipe 12D to be cooled, and becomes an air flow in a solid / gas mixed state and flows into the fourth cyclone 14D. In the cyclone 14D, the regenerated adsorbent that has been cooled and further lowered in temperature is separated from the air, and the air is sent to the lower chamber of the fourth bag filter 15D,
On the other hand, the regenerated adsorbent drops downward and drops in the fourth receiver 16
Collect in D. The air flowing into the lower chamber contains a fine regenerated adsorbent that cannot be completely separated in the fourth cyclone 14D, but this regenerated adsorbent and air are completely separated in the fourth bag filter 15D. The separated air is discharged into the atmosphere from the exhaust port 19, the regenerated adsorbent drops downward, and is sent into the fourth receiver 16D via the rotary valve 21D. This 4th receiver 16D
The regenerated adsorbent accumulated inside is cooled and sent into the pipe 12E by the rotary valve 23D.
After being mixed with air at room temperature flowing in 2E, it is sent to the adsorbent nozzle 13B and ejected from the nozzle 13B into the gas pipe 9B. In this way, in the adsorbent supply means 5, the adsorbent in the high temperature state regenerated by the high temperature heat treatment means 4 is fed by the fourth airflow transfer passage 10D, the fourth cyclone 14D and the fourth bag filter 15D.
While being cooled, it is separated from the air, and the regenerated adsorbent is returned to the adsorption airflow transfer means 1 by the fifth airflow transfer path 10E,
It can be reused for the adsorption of exhaust gases.

The first processing means 6 comprises a cooler 29 and a solvent recovery device 30. The cooler 29 has, for example, a gas-liquid type heat exchanger as an element member, and the inlet side end of the gas side flow passage is connected to the exhaust port 19 of the second bag filter 15B by a pipe line 31. The cooling water is circulated in the liquid side flow passage. As the solvent recovery device 30, for example, an adsorption type solvent recovery device using activated carbon as an adsorbent is used,
The inlet side end is connected to the outlet side end of the gas side passage of the cooler 29 by the pipe line 31.

The concentrated harmful / odorous gas discharged from the exhaust port 19 of the second bag filter 15B is cooled by the cooler 29.
It is cooled by, sent to the adsorption type solvent recovery device 30, and adsorbed on the activated carbon. In this way, the first processing means 6 collects the harmful / odorous gas by adsorption.

The second processing means 7 comprises an oxidative decomposition device 33. As the oxidative decomposition apparatus 33, for example, a direct combustion furnace in which a combustion burner 34 is provided in the furnace is used, and the gas inlet of the furnace is provided by a pipe 32 to the third bag filter 15
It is connected to the exhaust port 19 of C, and the inflow side end of the chimney and the conduit 24 is connected to the exhaust port of the furnace.

The exhaust gas discharged from the exhaust port 19 of the third bag filter 15C is directly fed to the combustion furnace 3 through the pipe 32.
3 is exhausted into the atmosphere from the stack by being burned and burned therein to be harmless, and a part of the exhaust gas is taken in by the pipe line 24 and, as described above, the low temperature heat treatment means. It is used as a carrier hot air stream in the second air stream transport path 10B of No. 4 and the third air stream transport path 10C of the high temperature heat treatment means 5. In this way, in the second treatment means 7, the exhaust gas that has been thermally decomposed and separated by the high temperature heat treatment means 4 is detoxified, and the high temperature gas generated during this detoxification treatment is cooled to the low temperature of the low temperature heat treatment means 3. The region gas and the high temperature region gas of the high temperature heat treatment means 4 are used. As the oxidative decomposition device 33, a catalytic oxidation device may be used instead of the direct combustion furnace.

In this embodiment, the detoxification process of the exhaust gas is carried out by the two processing means of the first processing means 6 and the second processing means 7, but the first processing means 7 is omitted and the pipe is By connecting the passage 32 to the exhaust port 19 of the second bag filter 15B, the exhaust gas separated by the low-temperature heat treatment means 3 and the high-temperature heat treatment means 4 is simultaneously detoxified by the second treatment means 7. You may do it.

FIG. 2 is an adhesion / adsorption characteristic diagram in the adsorption airflow conveying means 1 shown in FIG. In FIG. 2, point F shows the position where the first adsorbent nozzle 13A is provided, and point G shows the position where the second adsorbent nozzle 13B is provided. In addition, the point H is the second bag filter 15
The lower chamber inlet position of B is shown. Point F in gas line 9A
Then, it is necessary to adsorb and attach as much as possible high concentration components of the mist, high boiling point substances and harmful / malodorous gas components to the gas to be treated, which has a high concentration, by a powdery adsorbent. Yes, for example, it is adsorbed and adhered to such an extent that the concentration of the component is reduced from 100 ppm to 20 ppm. In this case, since it is an adsorption / adhesion process under high concentration, it does not need to be a regenerated adsorbent,
Sufficient adsorption / adhesion treatment is possible by reusing the adsorbent that has been adsorbed / adhered and is a little dirty. On the other hand, at point G in the gas pipe 9B, since it is necessary to further adsorb and adhere in a low-concentration component, for example, in a lean state of 20 ppm, the regenerated adsorbent in a clean state is supplied from the adsorbent supply means 5. By supplying it, highly efficient adsorption / adhesion treatment can be performed. As shown in FIG. 2, between the points G and H, it is possible to treat the target gas having a component concentration of 20 ppm to a harmless state of about 1 ppm.

The screw feeder in the embodiment may be a fixed feeder such as a spiral feeder or a vibrating feeder, and the rotary valve may be replaced by a double damper. The receivers 16B, 16C and 16D are not essential and may be omitted.

[0048]

As described above, according to the present invention, a powdery adsorbent is mixed with a gas to be treated containing a mist, a high-boiling point substance, and a harmful or malodorous gas in the course of air flow conveyance, thereby adhering and adsorbing. In addition, it is further divided into two stages, low temperature heat treatment and high temperature heat treatment, to cause desorption / desorption of harmful / malodorous gas by desorption treatment first, and mist by pyrolysis, high boiling point substances Since the separation treatment is performed next, the highly efficient exhaust gas treatment can be stably performed.

Further, according to the present invention, the temperature range 2 is different.
By performing the stepwise treatment, it is possible to treat the exhaust gas with extremely high safety without causing ignition or the like.

Further, the present invention is excellent in operating economy because the high temperature gas generated in the process of detoxifying exhaust gas can be used as the heating gas for the low temperature heat treatment and the high temperature heat treatment.

Further, according to the present invention, the gas to be treated containing the mist, the high-boiling substance, and the harmful / malodorous gas is passed through the air flow passage,
Since the detoxification treatment can be performed by a general-purpose device having a relatively simple structure such as a cyclone and a bag filter, a low-cost exhaust gas treatment device can be provided.

[Brief description of drawings]

FIG. 1 is a system diagram of an exhaust gas treating apparatus that is an embodiment of the present invention.

FIG. 2 is an adhesion / adsorption characteristic diagram in the adsorption airflow conveying means 1 shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adsorption air flow carrying means 2 Separation means 3 Low temperature heat processing means 4 High temperature heat processing means 5 Adsorbent supply means 6 First processing means 7 Second processing means 8 Processed gas 10A to 10E First to fifth air flow carrying paths 14A -14D 1st-4th cyclone 15A-15D 1st-4th bag filter 30 Solvent recovery apparatus 33 Oxidation decomposition apparatus

Claims (5)

[Claims] 1. A powdery adsorbent is mixed with a gas to be treated containing a mist, a high-boiling substance, and a harmful / odorous gas to adsorb the harmful / odorous gas to the mist and a high-boiling substance. After adhering to the adsorbent, the adsorbent that has been adsorbed and adhered is brought into contact with a desorbable low-temperature gas to desorb the adsorbed harmful / malodorous gas, and then the high temperature. Contact with the gas in the area to thermally decompose the adhering mist and high-boiling-point substances, desorb, separate the gas components generated by thermal decomposition from the powdery adsorbent, and
An exhaust gas treatment method, which comprises recovering or detoxifying treatment and returning the regenerated powdery adsorbent to be mixed with a gas to be treated. 2. An adsorbing airflow conveying means for admixing and adsorbing while admixing a powdery adsorbent with a gas to be treated containing a mist, a high boiling point substance, and a harmful / malodorous gas, and adsorbing the adsorbent. Separation means for separating the adsorbent from the gas to be treated containing the powdery adsorbent from the adsorption air flow conveying means, and the adsorbent separated by the separation means and the gas in the low temperature range are mixed to be harmful. / While desorbing offensive odor gas,
The low temperature heat treatment means for separating the desorbed harmful / odorous gas and the adsorbent, the adsorbent separated by the low temperature heat treatment means and the gas in the high temperature range are mixed and adhered to the adsorbent. The high temperature heat treatment means for thermally decomposing the mist and the high boiling point substance, and separating the gas and the adsorbent generated by this thermal decomposition, and the regenerated adsorbent separated by the high temperature heat treatment means are cooled to An adsorbent supply means for supplying to the air flow conveying means for adsorption; and a detoxification treatment means for detoxifying the harmful / malodorous gas separated by the low temperature heat treatment and the gas separated by the high temperature heat treatment means. An exhaust gas treatment device characterized by: 3. The exhaust gas treatment according to claim 2, wherein the low-temperature heat treatment means and the high-temperature heat treatment means include an air flow carrying means, a cyclone, and a bag filter, which are sequentially connected in series. apparatus. 4. The detoxification processing means is an oxidative decomposition apparatus that performs a combustion action, and the high temperature gas generated in the oxidative decomposition apparatus is a low temperature range gas of the low temperature heat processing means and a high temperature of the high temperature heat processing means. Claim 2 or 3 utilized for the area gas
The exhaust gas treatment device according to. 5. The adsorbent supply means is a cooling device including an air flow carrying means for using atmospheric air as a carrier air flow, a cyclone separator, and a bag filter, and the adsorbent after regeneration is used as a carrier air stream for processing gas to be treated. The exhaust gas treatment device according to claim 2, 3 or 4, further comprising: an air flow conveying means for mixing.