JPH0647245A - Exhaust gas treating device - Google Patents

Abstract

PURPOSE:To clean gases to be treated by removing the harmful/malodorous gaseous components, mists and high boiling materials contained in the gases to be treated with high efficiency. CONSTITUTION:Plural dust collecting means 1, 2, 3 which separate and capture powdery adsorbents with an adsorbent capturing device after executing adsorption and adhesion by mixing the gases G to be treated contg. the mists, high boiling materials and harmful/malodorous gases and the incombustible powdery adsorbents in a pneumatic transportation path are provided in series along the flow of the gases G to be treated. Regenerating means 4, 5 which desorb the harmful/malodorous gases from the heavily contaminated powdery adsorbents captured by the dust collecting means 1 of the initial stage by a heating treatment and thermally decompose the mists and high boiling materials are provided. An adsorbent supplying means 6 which cools the cleanest powdery adsorbents captured by the regenerating means 4, 5 and introduces these adsorbents to the dust collecting means 3 of the final stage and intermediate pneumatic transporting means 10A, 10F which introduce the powdery adsorbents captured by the dust collecting means 2, 3 of the second and subsequent stages respectively to the dust collecting means 1, 2 just before these means are provided.

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, In addition, the present invention relates to an exhaust gas treatment device which separates harmful / odorous gas components and concentrates them into a small amount of air for efficient treatment.

[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 ten times higher than that of the raw adsorbent, and the adsorbent is mixed with the organic binder and auxiliary materials to be molded, so that the adsorption is performed. When the performance deteriorates, it is difficult to regenerate, and furthermore, since it is a heating system using hot air for regeneration, indirect heating cannot be performed, and the concentration 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 multi-stage air flow conveyance. In addition, by using a small amount of regeneration gas for easy and reliable desorption, exhaust gas treatment with a compact structure and highly concentrated and highly efficient exhaust gas treatment at low operating cost It is to provide a device.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides an air flow passage for adsorbing and adhering by mixing a non-combustible powdery adsorbent with a gas to be treated containing a mist, a high-boiling substance, and a harmful / odorless gas. And an adsorbent collecting device for separating and collecting the powdery adsorbent from the gas to be processed containing the powdery adsorbent that has passed through the air flow conveying path, and being connected in series along the flow of the gas to be processed. The plurality of dust collecting means provided and the powdery adsorbent collected by the first stage dust collecting means are brought into contact with the heating gas in the low temperature range to prevent harmful /
The odorless gas is desorbed, and then the desorbed powdery adsorbent is brought into contact with the heating gas in the high temperature range to thermally decompose the mist and high-boiling substances to regenerate the cleanest powdery adsorbent. Regenerating means for collecting, adsorbent supplying means for cooling the cleanest powdery adsorbent collected by the regenerating means and introducing it into the dust collecting means at the final stage, and dust collecting at the second and subsequent stages. The exhaust gas treating apparatus is characterized by including a plurality of intermediate stage airflow conveying means for respectively introducing the powdery adsorbent which is adsorbed and adhered by the means to the dust collecting means of the immediately preceding stage.

[0010]

According to the present invention, in each of the dust collecting means provided in series, first, the gas to be treated and the powdery adsorbent are mixed in the air flow passage to prevent harmful effects under direct contact. /
The malodorous gas is adsorbed, the mist and the high-boiling substance are attached, and then the adsorbent collection device separates and collects the powdery adsorbent that is adsorbed and adhered. It is sent to the next-stage dust collecting means. Therefore, the gas to be treated has a higher degree of cleanliness as it passes through the dust collecting means, and can be discharged as clean air containing only a few ppm of harmful / malodorous gas components in the final stage.

In this exhaust gas treatment, the concentration of gas components contained in the gas to be treated is the highest in the first stage dust collecting means, so the adsorbent collected is naturally in the most polluted state. It is possible to efficiently regenerate this into the cleanest adsorbent by the regenerating means. And
By supplying this clean adsorbent to the dust collecting means at the final stage by the adsorbent supply means, the adsorption performance at the final stage can be further enhanced.

Further, according to the present invention, the adsorbent adsorbed and adhered by the dust collecting means of each stage after the second stage is
Each intermediate stage air flow conveying means introduces it into the dust collecting means of the immediately preceding stage, and again serves for adsorption / adhesion. Therefore, as for the relationship between the concentration of the harmful / odorous gas component and the adsorption amount of the adsorbent, it is clear that the higher the concentration is, the larger the maximum adsorption capacity of the adsorbent is.
As the gas component concentration becomes lower with respect to the gas to be treated, the adsorbent with a smaller adsorbed amount and excellent adsorption capacity is brought into contact with the gas to be treated and the powdery adsorbent flows in a countercurrent direction. By making close contact, the adsorption performance of the entire apparatus can be further enhanced, and the same amount of adsorbent can be introduced through each dust collecting means to perform stable exhaust gas treatment.

According to the invention, in the regeneration means, the heat treatment is carried out stepwise by the two kinds of heating gas of the low concentration region and the high concentration region. When the adsorbent is regenerated, the regeneration temperature conditions are different between the harmful / odorous gas and the mist or high boiling point substance. The regeneration conditions of harmful / malodorous gas are 120 to 250 ° C., under which 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. The high-boiling substance varies depending on the type of substance, but is 250 ° C to 35 ° C.
Desorption can be carried out at a temperature of 0 ° C., and a part of it is thermally decomposed to generate tar and carbon, and 350 to 600 ° C. is required as a regeneration condition including these.

By the way, the reason why the heat treatment in the low temperature region is necessary is as follows. When heat treatment is performed under the regeneration conditions of mist and high boiling point substances, harmful / malodorous gas is also desorbed at the same time, but within the ignition temperature range of harmful / malodorous gas, harmful / malodorous gas is ignited, and the concentration becomes high due to 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. Further, as another reason, when the harmful / odorous gas is recovered, 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 point substance and impurities.

The heat treatment in the low temperature range and the heat treatment in the high temperature range can be carried out by using a rotary kiln or a ribbon mixer. Preferably, hot air can be uniformly heated by an air flow heating method, and a high temperature gas of a catalytic oxidizer in a post process or an oxidative decomposition apparatus such as a direct combustion furnace can be used as a heat source, which is economical. The amount of hot air used for heat treatment in the low temperature range is sufficiently small compared to the amount of gas to be treated, and harmful / malodorous gas in the gas to be treated is transferred into this hot air, which is harmful in the ratio of the amount of gas to be treated and the amount of hot air. / The malodorous gas will be concentrated.

The adsorbent used in the heat treatment in the low temperature range 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.

The device for producing the heated gas for mixing with the adsorbent in the low / high temperature region heat treatment means can be constituted by an air carrying path, a cyclone, a bag filter, etc. Effectively heat treated between cyclones. 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 heat treatment in the low temperature range is to be recovered, it is sent to and recovered by a small-sized solvent recovery device corresponding to the flow rate of the concentrated gas. When detoxifying by oxidative decomposition, it is sent to the oxidative decomposing device together with the exhaust gas after the heat treatment in the high temperature range to be detoxified.

The adsorbent after the high temperature region heat treatment is cooled and sent to the final stage dust collecting means. At that time, depending on the type of substance in the gas to be treated, the malodorous component generated in the decomposition process may remain, and the malodorous component may contaminate the purified gas used for the adsorption gas 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 device of the present invention is required to be a nonflammable material, such as zeolite, silica gel,
Although ceviolite or the like can be applied, the hydrophobic zeolite is a suitable adsorbent because it has a low hygroscopicity, a large amount of harmful / malodorous gas is adsorbed, 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.

[0021]

1 is a system diagram of an exhaust gas treating apparatus of a first embodiment of the present invention. The apparatus shown in FIG. 1 comprises a plurality of, for example, three dust collecting means 1, 2, 3, a regenerating means realized by a combination of a low temperature heating means 4 and a high temperature heating means 5, and an adsorbent. The supply means 6, the detoxification processing means realized by a combination of the first processing means 7 and the second processing means 8, and a plurality of, for example, two intermediate-stage airflow conveying means 1
0A and 10F.

The first-stage dust collecting means 1 is provided with a first adsorbent nozzle 13A in the middle thereof, and a gas pipeline 9A as an air flow passage through which a treated gas G such as coating exhaust gas flows.
It is constituted by a first cyclone 14A1 as an adsorbent collecting device. The non-combustible powdery adsorbent ejected from the first adsorbent nozzle 13A is mixed with the gas to be processed G flowing in the gas pipe 9A, and the gas to be processed G in the solid-gas mixture state is It is sent into the first cyclone 14A1.

In the first cyclone 14A1, an exhaust inner cylinder is concentrically arranged in the center of a cylindrical main body, and the outlet end of the gas pipeline 9 is connected to the upper part of the cylindrical wall of the main body. ,
On the other hand, the bottom wall of the main body is provided with an outlet having a rotary valve 20A.

The operation mode of the first stage dust collecting means 1 is as follows. The airflow flowing in the gas pipe 9, that is, the gas to be treated G mixed with the powdery adsorbent, flows into the main body of the first cyclone 14A1 in the connecting direction of the cylindrical wall, and swirls along the inner wall of the cylinder. While descending. In this way, harmful / odorous gas is adsorbed while flowing in the gas pipe 9 and the main body. The adsorbent, which is adhered and adsorbed, moves toward the wall due to centrifugal force in the descending process, is separated from the to-be-processed gas G that has been cleaned to a certain degree as an airflow, and travels down the wall. To fall. On the other hand, the to-be-processed gas G separated from the adsorbent flows into the exhaust inner cylinder at the center from the lower end, and the second adsorbent nozzle 1 is provided in the exhaust inner cylinder.
3B is mixed with the powdery adsorbent jetted from 3B and sent out. The adsorbent that has dropped downward is sent into the conduit 12B by the rotary valve 20A.

The second-stage dust collecting means 2 is composed of the gas pipe 9B and the second cyclone 14A2. The gas line 9B and the second cyclone 14A2 are similar to the gas line 9A and the cyclone 14A1, and corresponding parts are designated by the same reference numerals. The exhaust inner cylinder of the first cyclone 14A1 and the to-be-treated gas introduction port provided in the upper portion of the main body wall of the second cyclone 14A2 are connected by the gas pipeline 9B. Therefore, the second-stage dust collecting means 2 is connected in series with the first-stage dust collecting means 1.

The mode of operation of the second stage dust collecting means 2 is as described below. In the first stage dust collecting means 1, the gas to be treated G mixed with the powdery adsorbent in the exhaust inner cylinder flows through the gas pipeline 9B, and the first stage dust collecting means 1
Like the above, the adsorption / adhesion action is performed, the component gas concentration is lowered, and the cleaning is further performed. This gas to be processed G containing the adsorbent is separated from the gas and the adsorbent by a centrifugal action in the second cyclone 14A2, and the gas to be processed G is
Is mixed with the powdery adsorbent that flows into the exhaust inner cylinder in the center from the lower end and is ejected from the third adsorbent nozzle 13C provided in the inner cylinder. Is sent into the conduit 12A by the rotary valve B.

The last-stage dust collecting means 3 is composed of a gas pipeline 9C and a first bag filter 15A, and the gas pipeline 9C is an air flow carrying path corresponding to the gas pipelines 9A and 9B. The 1-bag filter 15A is an adsorbent trapping device corresponding to the first cyclone 14A1 and the second cyclone 14A2.

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 filter cloths, and the exhaust port 1 is provided on the top wall of the upper chamber.
9 is opened, the outlet end of the gas pipe 9C is connected to the upper side wall of the lower chamber, and the rotary valve 21 is connected to the bottom wall of the lower chamber.
An outlet with A is provided. On the other hand, the gas line 9C is
The inlet end is connected to the exhaust inner cylinder of the second cyclone 14A2. Therefore, the third-stage dust collecting means 3 is connected in series with the second-stage dust collecting means 2.

The operation mode of the last stage dust collecting means is as follows. In the second-stage dust collecting means 2, the gas to be treated G mixed with the powdery adsorbent in the exhaust inner cylinder
While flowing in the gas pipe 9C, the adsorbing / adhering action is performed as in the previous stage, the concentration of the component gas is further reduced, and the cleanliness is further enhanced. The gas to be processed G containing the adsorbent is sent to the lower chamber of the first bag filter 15A, and the gas to be processed G that has been cleaned passes through the filter 18 to the atmosphere from the exhaust port 19. It is released or collected. On the other hand, after the adsorbent is collected by the filter 18, the adsorbent is blown off by applying a reverse pressure or the like and drops to the bottom portion, and is sent into the pipe 10F by the rotary valve 21A.

On the other hand, the low temperature heating means 4 in the regenerating means
Is a second air flow carrier path 10B having a conduit 12B provided with a blower 11B in the middle as an element member, a second cyclone 14B, a second bag filter 15B, and a second receiver 1.
6B and. Regarding the second cyclone 14B and the second bag filter 15B, the second cyclone 14A2 of the dust collecting means 2 and the first bag filter 1 of the dust collecting means 3
Since the structure and the connection form are the same as those of 5A, the description thereof will be omitted. The conduit 12B has an inlet end connected to the conduit 24 for circulating high-temperature hot air, and an outlet end connected to an upper portion of the cylindrical wall of the main body of the second cyclone 14B. The pipe line 12B is located at the middle of the pipe line near the suction side of the blower 11B.
The blower 11 is connected to a pipe 25 through which a normal temperature air flow is circulated.
An intermediate part of the pipeline connected to the discharge side of B is connected to the outlet having the rotary valve 20A. In addition, pipeline 2
A temperature control valve 27 is provided at 5.

The second receiver 16B is connected to the second cyclone 1
4B and the second bag filter 15B, a pipe extending from the bottom outlet of the second cyclone 14B and a pipe having the rotary valve 21B of the second bag filter 15B are provided on the top wall of the main body container. Connected, the bottom wall is provided with an outlet having a rotary valve 23B.

The high temperature heat treatment means 5 in the regeneration means is
A third air current carrying passage 10C having a pipe 12C provided with a blower 11C in the middle thereof as an element member, and a third cyclone 14
C, the third bag filter 15C, and the third receiver 16C
With. They are the second in the low temperature heat treatment means 4.
Since it corresponds to the airflow transport path 10B, the second cyclone 14B, and the second bag filter 15B, respectively, and is the same in terms of structure and mutual connection form, description thereof will be omitted here.

The mode of operation of the regeneration means is as follows. The powdery adsorbent, which is most contaminated by adsorbing and adhering by the first cyclone 14A1 of the dust collecting means 1, is sent out by the rotary valve 20A and the conduit 1
It is put into 2B. The charged powdery adsorbent is maintained at a constant temperature by the temperature adjusting action based on the temperature detecting method of the temperature adjusting valve 27 and flows in the pipe 12B.
For example, mixing with a low temperature air stream of 300 ℃, 200 ℃
It becomes a gas flow in a solid / gas mixture state in which the temperature has dropped, and flows into the second cyclone 14B. 200 ° C in pipeline 12B
The adsorbent, which has been heated to a certain degree, releases (desorbs) the adsorbed harmful / malodorous gas. On the other hand, the attached mist and high-boiling-point substances are below the temperature (400 to 500 ° C.) at which they are thermally decomposed, and therefore remain attached. The air flow in the line 12B necessary for desorption of the case, the gas to be treated G flowing in the gas conduit 9A flow, relative to 100 m ³ / min, 3 to 5 m ³ /
A small amount of air is enough, and the desorbed gas is concentrated to a high concentration, so that the low temperature heat treatment means 4 including the second 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 accumulated in the second receiver 16B is sent out by the rotary valve 23B in a state where the mist and the high boiling point substance are adhered thereto, and the third air flow transfer path 10C is formed.
Is mixed with the hot air flow flowing in the pipeline 12C and is conveyed as an air flow. Thus, in the low temperature heat treatment means 3, the adsorbent fed from the first stage dust collection means 1 is heated at 120 to 240 ° C.
The harmful / malodorous gas is desorbed by heating to a low temperature in the range of 1, and the desorbed harmful / malodorous gas is separated from the adsorbent, and the adsorbent is sent to the next high-temperature heat treatment means 5 to remove the harmful / malodorous gas. Is sent to the first processing means 7.

The adsorbent sent out from the second receiver 16B in a fixed amount has mist and a high boiling point substance adhering thereto, and this adsorbent flows at a high temperature, for example, 600 ° C., flowing in the pipe 12C of the third air current carrying passage 10C. 400 ~
Heat to 500 ° C. The high-temperature airflow in the pipe 12C mixes the high-temperature airflow of about 800 ° C. flowing in the pipe 24 with the room-temperature airflow in the pipe 26 whose temperature is adjusted by the temperature control valve 28, so that a constant temperature is obtained. Held in.
The air flow in the solid / gas mixture state in which the adsorbent is mixed and flows in the conduit 12C is sent to the third cyclone 14C, but the mist and high boiling point substances adhering to the adsorbent are in the conduit 12C and The adsorbent is regenerated by being thermally decomposed in the third cyclone 14C at a high temperature and separated from the adsorbent. Most of the regenerated adsorbent is the third
The third receiver 2 is separated from the bottom by the cyclone 14C.
It is sent to 3C. On the other hand, the exhaust gas separated from the adsorbent is sent to the lower chamber of the third bag filter 15C, the adsorbent left unremoved and the exhaust gas are completely separated, and the regenerated adsorbent dropped downward is the rotary adsorbent. Valve 21
After passing through C, 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 means 8 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 path 10D in the adsorbent supply means 6 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 5, the adsorbent fed from the low-temperature heat treatment means 4 is heated to a high temperature in the range of 400 to 500 ° C., and the attached mist and high boiling point substances are thermally decomposed and separated. Then, the regenerated adsorbent is sent to the next adsorbent supply means 6, and the exhaust gas generated by the thermal decomposition is sent to the second treatment means 8.

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 transport path 10D, the fourth cyclone 14D, the fourth bag filter 15D, and the fourth receiver 16D include the second airstream transport path 10b in the low-temperature heat treatment means 4, the second cyclone 14B, and the second 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 of the conduit 12E in the fifth airflow transport passage 10E is connected to the third adsorbent nozzle 13C provided in the exhaust inner cylinder of the second cyclone 14A2.

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 which cannot be completely separated in the fourth cyclone 14D, but the 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 by a fixed amount through the rotary valve 21D. The regenerated adsorbent accumulated in the fourth receiver 16D is cooled to near the constant temperature, and is fed into the pipe line 12E in a fixed amount by the rotary valve 23D and mixed with the air at room temperature flowing in the pipe line 12E. After that, the third adsorbent nozzle 13
C, and is ejected from the nozzle 13C into the exhaust inner cylinder. In this way, in the adsorbent supply means 6, the high-temperature adsorbent that has been regenerated by the high-temperature heat treatment means 5 is cooled by the fourth airflow transport passage 10D, the fourth cyclone 14D and the fourth bag filter 15D. The regenerated adsorbent that is separated from the air while being separated is provided to the third dust collecting unit 3 at the final stage by the fifth airflow transfer passage 10E.
It is returned to the adsorbent nozzle 13C and reused for adsorbing the exhaust gas.

Each of the intermediate stage air flow transfer means 10A, 10F is
Blowers 11A, 11F that take in the air and discharge it at room temperature
And conduits 12A, 12F having inlet ends connected to the discharge ports of the blowers 11A, 11F, and outlet ends connected to the first adsorbent nozzle 13A and the second adsorbent nozzle 13B, respectively. With. In the middle of these pipes, the rotary valve 20B outlet of the second cyclone 14A2 and the rotary valve 21A of the first bag filter 15A are provided.
The outlets are branched and connected.

The first intermediate-stage airflow conveying means 10A includes an adsorbent sent from the rotary valve 20B, that is, a second adsorbent.
The first adsorbent provided on the gas inflow side of the first-stage dust collecting means 14A1 passes through the pipe 10A by the atmosphere of the carrier airflow to absorb the adsorbent, which has been adsorbed and adhered by the stage dust collecting means 2 by a considerable amount. It is introduced into the agent nozzle 13A, and the adsorbent is conveyed so as to be used for adsorption / adhesion again.

On the other hand, the second intermediate stage air flow transfer means 10F is
The adsorbent sent out from the rotary valve 21A, that is, the adsorbent having a small amount of adsorption / adhesion collected by the final stage dust collecting means 3 is passed through the conduit 10F by the atmosphere of the carrier airflow to the second stage dust collecting means. It is introduced into the second adsorbent nozzle 13B provided on the gas inflow side of 14A2, and the adsorbent is conveyed so as to be used for adsorption / adhesion again. The rotary valve may be replaced by a double damper.

The first processing means 7 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.
After being cooled by, it is sent to the adsorption type solvent recovery device 30 and adsorbed on the activated carbon. In this way, the first processing means 7 collects the harmful / malodorous gas by adsorption.

The second processing means 8 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 supplied to the combustion furnace 3 through the pipe 32.
3 is exhausted into the atmosphere by being burned there and burned there to become harmless, and a part of the exhaust gas is taken in by the pipe line 24 and is subjected to the low temperature heat treatment as described above. It is used as a heat transfer air stream in the second air flow transfer path 10B of the means 5 and the third air flow transfer path 10C of the high temperature heat treatment means 6. In this way, the second treatment means 8 detoxifies the exhaust gas that has been thermally decomposed and separated by the high temperature heat treatment means 5, and the high temperature gas generated during the detoxification treatment is cooled to a low temperature by the low temperature heat treatment means 4. The region gas and the high temperature region gas of the high temperature heat treatment means 5 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 exhaust gas is rendered harmless by the two processing means of the first processing means 6 and the second processing means 8. However, the first processing means 8 is omitted and the pipeline is omitted. By further connecting 32 to the exhaust port 19 of the second bag filter 15B, the low temperature heat treatment means 4
The exhaust gases separated by the high temperature heat treatment means 5 and the high temperature heat treatment means 5 may be simultaneously detoxified in the second treatment means 8.

FIG. 2 is a system diagram of an exhaust gas treating apparatus which is a second embodiment of the present invention. The second embodiment of FIG. 2 is similar to the first embodiment shown in FIG. 1, and corresponding parts are designated by the same reference numerals. What should be noted in FIG. 2 is that a two-stage exhaust gas treatment apparatus in which the powdery adsorbent is mixed with the gas to be treated G in two stages by the first and second adsorbent nozzles 13A and 13B is This is different from the three-stage system of the first embodiment. The first-stage dust collecting means 1 corresponds to the first embodiment of FIG. 1, and the second-stage final collecting means 2 is constituted by a second cyclone 14A2 and a first bag filter 15A. Are connected in series, and the adsorbent collected is introduced into the dust collecting means 1, which is the immediately preceding stage, and is again used for adsorption / adhesion. Therefore, the intermediate airflow conveying means 10F in FIG. 1 is omitted. In addition,
The structures and connection forms of the respective means 4, 5, 6, 7, and 8 are the same as those in the example shown in FIG.

FIG. 3 is a perspective view showing an essential part of an exhaust gas treating apparatus which is an embodiment of the present invention. The apparatus shown in FIG. 3 is a large apparatus used when the amount of treated air is very large, and the structure of the dust collecting means 1, 2, 3 is shown. When the amount of treated air is very large, a plurality of cyclones are required, and the same applies to the bag filter. Therefore, as shown in the figure, in the first stage dust collecting means 1, the cyclone 14A
1, 14A1 are provided in parallel, and the cyclone 14A2, 14A2 is also provided in parallel in the second stage dust collecting means 2, so that it is possible to sufficiently cope with a high air volume.

FIG. 4 is a system diagram of an exhaust gas treating apparatus which is a fourth embodiment of the present invention. The device shown in FIG. 4 is similar to the first embodiment of FIG. 1, and the corresponding parts bear the same reference numerals. In the apparatus shown in FIG. 4, it should be noted that the dust collecting means is composed of four groups of the first stage 1, the second stage 2, the third stage, and the final stage n. It is provided in series with the reference, the adsorbent collected by the first stage dust collecting means 1 is introduced into the last stage dust collecting means n after being regenerated, and the second and subsequent stage dust collecting means 2, The various points in which the adsorbent collected by 3, n is introduced into the dust collecting means 1, 2, 3 of the immediately preceding stage are common to the first and second embodiments. In FIG. 4, a frame to which a reference numeral 35 is attached is a regeneration including a low temperature heat treatment means 4, a high temperature heat treatment means 5, an adsorbent supply means 6, a first treatment means 7, and a second treatment means 8. The device is schematically shown as a whole.

FIG. 5 is an isotherm adsorption diagram showing the relationship between the concentration and the adsorption amount of the adsorbent, which corresponds to the adsorption operation of the third embodiment shown in FIG.

Explaining with reference to FIGS. 4 and 5, it is assumed that the concentration P of the gas component to be processed of the gas to be processed G at the inlet of the gas pipeline 9A is 100 ppm, for example.
The gas component is adsorbed by bringing the adsorbent of the adsorption amount Q4 ejected from the adsorbent nozzle 13A into contact.
By this adsorption, the amount of adsorbent adsorbed increases to Q5.

The adsorbent having the adsorption amount Q5 is conveyed to the regenerator 35 by air flow, and is heated to be regenerated to become the cleanest powdery adsorbent having the adsorption amount reduced to Q1. After cooling the adsorbent, the adsorbent is introduced into the bag filter 15A of the last-stage dust collecting means n and brought into contact with the gas to be treated G having a small amount of gas components to cause an adsorption action. The adsorbent whose adsorbed amount has increased to Q2 by this adsorbing action is introduced into the third cyclone 14A3 of the dust collecting means 3 immediately before and adsorbed.

The adsorbent whose adsorbed amount is Q2 has an adsorbed amount increased to Q3 by the adsorbing action, and the third cyclone 14A3
And the second cyclone 14A of the dust collecting means 2 immediately before.
2 is introduced to cause adsorption. The adsorbent whose adsorbed amount is increased to Q4 by this adsorbing action, after being collected, is introduced into the gas pipe 9A connected to the immediately preceding dust collecting means 1 to perform adsorbing action.

As described above, the adsorbent separated after being adsorbed by the second and subsequent dust collecting means 2, 3, n is returned to the inlet side of the immediately preceding dust collecting means 1, 2, 3 and The adsorbent separated after being adsorbed by the dust collecting means 1 is returned to the last-stage dust collecting means n after being regenerated by the regenerating means.
It is clear that the gas to be treated G and the powdery adsorbent are in an operation state close to countercurrent contact when the gas component concentration is used as a reference, and it is possible to enhance the adsorption efficiency and to regenerate the gas. With the means, the highly concentrated adsorbent can be regenerated, and the adsorbent to be brought into contact with the gas to be treated G may be the same amount in any of the dust collecting means 1 to n.

In each of the embodiments described above, the final stage dust collecting means is constituted by a bag filter as an element. However, this has a high dust collecting efficiency as compared with a cyclone, and the atmosphere at the final stage is It is nothing else than taking measures to prevent contamination, and depending on the treatment mode, it may be replaced with a cyclone, and is an example of FIG. 2 configured by combining a cyclone and a bag filter. May be.

[0057]

As described above, according to the present invention, after the gas to be treated is cleaned by the adsorption / adhesion action of the adsorbent, the dust collecting means for separating and collecting the adsorbent is provided in two or more stages in series. In the first stage where the concentration of the gas to be treated is high, the adsorbent is brought into contact with the adsorbent having the largest adsorption amount, and after the second stage where the concentration of the component is gradually decreased, the adsorption amount is gradually reduced. Since the adsorption is performed by, stable adsorption operation can be performed at each stage without excess or deficiency in adsorption capacity.
Since the adsorption operation resembles the countercurrent contact relationship while using the air flow transfer system, highly efficient exhaust gas treatment can be performed while maintaining the same amount of adsorbent input in each stage.

Further, according to the present invention, since the adsorbent which is regenerated by the regenerating means adsorbs at a high component concentration close to the limit amount, a small amount of regenerating gas is required for regeneration. The device can be made compact.

[Brief description of drawings]

FIG. 1 is a system diagram of a first embodiment of the present invention.

FIG. 2 is a system diagram of a second embodiment of the present invention.

FIG. 3 is a perspective view showing an essential part of an embodiment of the present invention.

FIG. 4 is a system diagram of a third embodiment of the present invention.

5 is an isothermal adsorption diagram corresponding to the third embodiment of FIG. 4. FIG.

[Explanation of symbols]

 1 First-stage Dust Collection Means 2 Second-stage Dust Collection Means 3 Final-stage Dust Collection Means 4 Low Temperature Heat Treatment Means for Regeneration Means 5 High Temperature Heat Treatment Means for Regeneration Means 6 Adsorbent Supply Means 9A-9D Air Flow Conveying Path 10A, 10F Intermediate stage air flow carrying means 14A1 to 14A3 Adsorbent collection device 15A Adsorbent collection device G Gas to be treated

Claims (1)

[Claims] 1. An air flow carrying path for adsorbing and adhering by mixing a non-combustible powdery adsorbent with a gas to be treated containing a mist, a high boiling point substance, and a harmful / odorous gas, and an air flow carrying path. An adsorbent collection device for separating and collecting the powdery adsorbent from the gas to be treated containing the powdery adsorbent, and a plurality of dust collecting means provided in series along the flow of the gas to be treated , The powdery adsorbent collected by the first-stage dust collecting means is contacted with the heating gas in the low temperature range to desorb the harmful / odorous gas, and then the desorbed powdery adsorbent in the high temperature range. Regeneration means for contacting with heated gas to pyrolyze mist and high boiling point substances to regenerate and collect into the cleanest powdery adsorbent, and the cleanest powdery powder collected by the regenerating means. The adsorbent supply means for cooling the adsorbent and introducing it into the dust collecting means at the final stage and the dust collecting means at the second and subsequent stages collect the adsorbent. An exhaust gas treating apparatus comprising: a plurality of intermediate stage air flow conveying means for introducing the adsorbed and adhering powdery adsorbent into the dust collecting means of the immediately preceding stage.