JP2013086018A - Method of operating organic compound treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent useless emission of residual steam for desorption remaining in adsorption towers 11a and 11b for adsorption of organic compounds, at the timing when desorption is completed with steam for desorption, and occurrence of white smoke due to the emission of the residual steam.SOLUTION: A method of operating, or controlling, an organic compound treating apparatus uses two or more adsorption towers 11a and 11b having, inside them, an adsorption layer packed with an adsorbent adsorbing volatile organic compounds and includes introducing a gas containing a volatile organic compound into at least one of the adsorption towers, making the volatile organic compound adsorbed with the adsorbent to reduce the content of the volatile organic compound and then discharging the treated gas, introducing steam for desorption, in order, into adsorption towers after carrying out adsorption to desorb the volatile organic compound from the adsorbent and reusing the adsorbent. At the timing when the desorption is completed, residual steam for desorption remaining within the adsorption tower is transferred to an adsorption tower to then carry out desorption and/or an adsorption tower having started desorption.

Description

  The present invention relates to a control method for a processing apparatus that removes an organic compound from a gas before discharging the gas containing the organic compound.

  Exhaust gas generated from factories may contain volatile organic compounds that cause problems if discharged into the atmosphere as they are. In this case, before exhaust gas is discharged into the atmosphere, the contained volatile organic compounds must be treated. As a method for this, an adsorption tower containing activated carbon or other adsorbent is used to adsorb volatile organic compounds contained in exhaust gas to the adsorbent, reduce the concentration in the gas and discharge it to the atmosphere. An adsorption / desorption system is generally used in which a volatile organic compound is desorbed to make the adsorption tower reusable and the volatile organic compound is treated.

  For the above desorption, it is necessary to bring a gas not containing a volatile organic compound into contact with the adsorbent. Since adsorption cannot be performed simultaneously with desorption by a single adsorption tower, desorption is preferably carried out promptly. As a method of speeding up desorption, a method of introducing a large amount of desorption gas, a method of reducing pressure by suction with a vacuum pump, a method of introducing high-temperature desorption water vapor to promote desorption, which is an endothermic reaction, etc. In view of cost and efficiency, many methods using high-temperature desorption water vapor are used.

  In any case, in order to always continue the exhaust gas treatment, at least two adsorption towers must be arranged in parallel, and while one is performing the desorption process, another adsorption tower must be responsible for the adsorption process. Each column performs an adsorption process and a desorption process alternately.

  When desorption is performed with high-temperature steam, the adsorption tower immediately after the desorption step is filled with high-temperature steam. When exhaust gas is introduced here and high-temperature water vapor is pushed out, white smoke is generated from the discharge port into the atmosphere. Although its true identity is only steam, it tends to be a problem in appearance, and means for preventing the generation of white smoke are being studied.

  For example, a method has been proposed in which a condenser is connected to the outlet side of the adsorption tower, outside air is introduced, water vapor is pushed out to the condenser, and water vapor is condensed and recovered by the condenser ([0024] of Patent Document 1).

  Patent Document 2 describes a method in which two adsorption towers are connected in series, the gas to be treated is flowed to the upstream adsorption tower, and the exhaust gas is flowed to the downstream adsorption tower ([0011 of Patent Document 2]. ]).

  On the other hand, a method for saving fuel by supplying water vapor after desorbing organic matter to a combustion furnace that generates heat for obtaining water vapor and burning the organic matter is being studied (Patent Document 3). .

JP 2005-66503 A JP 2001-179041 A JP 2007-2222736 A

  However, when a capacitor is provided as in Patent Document 1, the number of parts increases, which complicates the apparatus, makes control difficult, and increases the cost.

  On the other hand, Patent Document 2 describes that the gas once adsorbed as the gas to be treated is introduced into another adsorption tower, but there is no description or suggestion regarding the surplus of desorption water vapor as a problem. Not at all.

  Moreover, even if an attempt is made to send desorption water vapor to the combustion furnace as in Patent Document 3, since the organic matter contained in the water vapor remaining in the adsorption tower at the time of desorption completion is small, this water vapor is introduced into the combustion furnace. However, the total amount of fuel that can be supplied is reduced, the amount of heat to be generated in the combustion furnace is reduced, and the amount of heat for obtaining water vapor necessary for desorption may not be covered.

  Furthermore, releasing high-temperature water vapor as it is or condensing it is a problem in terms of energy saving because it is a large loss in energy.

  Accordingly, an object of the present invention is to easily prevent the generation of white smoke due to water vapor remaining in the adsorption tower after completion of desorption, and to improve the energy efficiency.

  This invention transfers the remaining desorbed water vapor remaining in one adsorption tower at the time when the desorption process is completed, so that another adsorption tower to be desorbed from now on, another adsorption tower that has started desorption, or both The above-mentioned problem was solved by moving the system into the area.

  That is, since the remaining desorption water vapor still has a sufficient amount of heat, when it is transferred to another adsorption tower from which desorption begins, the amount of heat can be used for the heating required at the start of desorption. The water vapor can be saved. Moreover, when it is transferred into another adsorption tower which has already started desorption, it can be used as a part of desorption water vapor. In particular, it is effective to introduce at the start of desorption. The adsorption layer is not sufficiently warmed at the start of desorption, and even if desorption water vapor is introduced, desorption does not proceed easily just because it is consumed for preheating, but it can compensate for the waste. It is. If it is transferred to another adsorption tower, the corresponding water vapor can be circulated and processed in the same line as other desorption water vapor, so that no white smoke is generated from the apparatus.

  As a specific transfer-in / out method, a line for that purpose may be provided separately, but the apparatus becomes complicated accordingly, so the steam supply line for supplying the above-mentioned desorption steam that has been used originally If this is performed by reversely feeding a part of the apparatus, expansion of the apparatus can be suppressed and the present invention can be implemented.

  When there are multiple stages of the desorption water vapor supply ports in the height direction of the adsorption tower, the residual desorption water vapor is supplied from the lowermost supply port, so that it is not a part of the adsorption layer. The whole can be warmed up efficiently.

  By this invention, it is possible to efficiently use for preheating other adsorption towers without wasting the amount of heat that the residual desorption steam has, and it is also possible to prevent the generation of white smoke due to the discharge of the steam. Circulation and recycling within the system can be improved.

Configuration diagram showing an example of an organic compound processing apparatus for carrying out the present invention Flow chart in the first embodiment of the present invention Flow chart in the second embodiment of the present invention Configuration diagram of organic compound processing equipment with combustion furnace and heat exchanger

  The present invention will be specifically described below. This invention has a plurality of adsorption towers each having an adsorption layer filled with an adsorbent that adsorbs volatile organic compounds, and a gas containing a volatile organic compound is introduced into at least one of the adsorption towers. The volatile organic compound is adsorbed on the adsorbent, and the treated gas is discharged to reduce the content. After the adsorption, the desorption water vapor is sequentially introduced into the adsorption tower to volatilize the adsorbent. This is a method for controlling an organic compound processing apparatus, which is used again for adsorption after desorbing the organic compound.

  The volatile organic compound processed by the organic compound processing apparatus for carrying out the present invention is an organic compound that can be turned into a gas when heated at normal pressure, and particularly a liquid that is liquid at room temperature is easily adsorbed. Examples thereof include hydrocarbon solvents such as alcohols having about 1 to 8 carbon atoms such as methanol, ethanol and isopropyl alcohol, and aromatic organic compounds such as toluene and benzene.

  First, an embodiment having an apparatus having two adsorption towers in parallel shown in FIG. 1 will be described, but three or more adsorption towers may be arranged in parallel. Moreover, as long as two or more units are provided in parallel, a plurality of each column may be connected in series.

  This organic compound processing apparatus has two adsorption towers 11 (11a, 11b). Each of the adsorption towers 11a and 11b has a substantially cylindrical shape, and a single perforated plate 20a and 20b is provided in the vicinity of the lower end. The perforated plate 20 (20a, 20b) is sized to cover the entire cross section of the adsorption tower 11. The perforated plate 20 is filled with an adsorbent that can adsorb volatile organic compounds and can be desorbed by heating. The adsorbing layer 12 (12a, 12b) is provided. Examples of the adsorbent include activated carbon particles having a particle diameter larger than the holes of the perforated plate. The adsorption layer 12 does not reach the upper and lower ends of the adsorption tower 11 and has hollow portions on both the upper and lower sides.

  The inlet 13 (13a, 13b) for the volatile organic compound-containing gas A is provided at the upper end side of the adsorption layer 12 of the adsorption tower 11, and the post-treatment gas B outlet is provided at the lower end side of the adsorption layer 12. 15 (15a, 15b) are provided. Each mouth has a valve. Among these, the discharge port 15 is discharged into the atmosphere. Moreover, although not shown in figure at the bottom part on the lower end side, there is provided a drainage port for discharging water produced mainly by condensation of steam. The volatile organic compound-containing gas A is generated by another apparatus or the like, and is a processing target for removing the volatile organic compound to form a post-processing gas B. For example, various exhaust gas etc. are mentioned. When the volatile organic compound-containing gas A passes through the adsorption layer 12 introduced from the inlet 13 to the outlet 15, the volatile organic compound is adsorbed by the adsorbent, and the volatile organic compound It becomes the after-treatment gas B having a reduced concentration.

  Supply ports 24 (24a, 24b) for supplying desorption water vapor F to a part of the adsorption layer 12 are provided on the side surface of the adsorption tower 11 where the adsorption layer 12 is provided. Supply ports 25 (25a, 25b) for supplying desorption water vapor F to the entire adsorption layer 12 are provided at the bottom below the layer 12. Each of these ports is provided with a valve. These supply ports 24 and 25 are connected to a water vapor supply line 21 connected to a supply source of desorption water vapor, and the branch points 22 and thereafter are divided toward the respective adsorption towers 11. The steam supply line 21 is provided with a valve 23 for preventing backflow before the branch point 22.

  The desorption water vapor F supplied from the supply ports 24 and 25 is cooled by the adsorption layer 12 immediately after the start of supply, and most of the water is condensed and discharged as a large amount of water (drain) from the drain port. When the temperature of the adsorption layer 12 rises with the supply of the water vapor F for use, it partially condenses to become water (mist) and the above mixture, desorbs the volatile organic compound adsorbed on the adsorption layer 12, and gas or In a droplet (mist) state, the volatile organic compound ascends and rises and exits from the outlet 26 (26a, 26b) provided at the top of the adsorption tower 11 (volatile organic compound-containing water vapor K). . However, once desorption is performed, residual desorption water vapor, which will be described later, bears a part of this process.

  Further, each of the supply ports 25 (25a, 25b) is provided with a water vapor temperature sensor, and the temperature can be measured when residual desorption water vapor described later passes.

  The operation procedure of the operation method of the volatile organic compound processing apparatus having the above configuration will be described together with the flow of FIG. 2 and the status transition table of Table 1. In Table 1, “open” indicates that the corresponding valve is opened, and “close” indicates that the corresponding valve is closed. “In” indicates that gas flows into the tower through the corresponding portion, and “out” indicates that gas flows out of the tower through the corresponding portion. “-” Indicates that it remains closed and does not change, and “|” indicates that it remains open.

  In the volatile organic compound processing apparatus according to the present invention, first, (S100), the inlet 13 (13a or 13b) connected to one adsorption tower 11 (11a or 11b) is opened, and the volatile organic compound-containing gas A is removed. It introduce | transduces into the one adsorption tower 11 (11a or 11b), and begins to adsorb | suck to the adsorption agent of the adsorption layer 12 (S101). Here, the adsorption is started from the tower “a”. The treated gas B that has passed through the adsorption layer 12a exits from the outlet 15a and is released into the atmosphere. This adsorption work is performed until a predetermined time elapses or until the adsorption capacity becomes below a certain level (S102).

  On the other hand, preparation for desorption is proceeded before the adsorption is completed. That is, preparations are made so that steam at a high temperature sufficient for desorption can be supplied by a supply source of desorption steam F connected to the steam supply line 21.

  Next, in order to finish the adsorption in the adsorption tower 11a, the valve of the inlet 13a is closed (S103). At the same time, the valve of the inlet 13b is opened, or the valve of the inlet 13b is opened slightly earlier than the valve of the inlet 13a is closed, and the adsorption process is shifted from the adsorption tower 11a to the adsorption tower 11b (S103). Then, the valve 23 of the water vapor supply line 21 is opened, the upper supply port 24a of the adsorption tower 11a is opened (S104), and desorption of a part of the adsorption layer 12a (only the upper part) is started (S105). After a certain period of time has elapsed, the supply port 25a at the bottom of the adsorption tower 11a is opened (S106), and desorption is started for all of the adsorption layer 12, thereby allowing multistage desorption to proceed (S107). By performing such multi-stage desorption start, the concentration of the volatile organic compound to be desorbed is leveled over time, and the load when processing the volatile organic compound-containing water vapor K to be released is dispersed. Can do. If the concentration temporarily increases extremely, the processing load for separating and burning the volatile organic compound-containing water vapor K at that stage increases, but the increase in the load can be suppressed by leveling.

  Specifically, desorption proceeds as follows. At first, the adsorption layer 12a is warmed by the supplied desorption water vapor F, and the water vapor is condensed and drained as water. After sufficiently heated, the desorption water vapor F causes the adsorption layer 12a to be volatile. Organic compounds are desorbed. This first occurs in the region of the adsorption layer 12a above the supply port 24a (S105), and then occurs in the remaining region of the adsorption layer 12a (S107). Through the desorption step, the desorbed volatile organic compound is delivered to the outside from the outlet 26a as volatile organic compound-containing water vapor K accompanied by mist or water vapor (S108). Since the volatile organic compound-containing water vapor K exiting from the outlet 26a contains a volatile organic compound, it is desirable to recover or use this in some form. For example, water and an organic compound may be collected by aggregating with a condenser or the like, or may be used as a part of fuel to be sent to a combustion furnace to obtain desorption water vapor F. Such desorption operation (S108) is performed until the volatile organic compound is sufficiently desorbed from the adsorption layer 12a. Specifically, until the amount of volatile organic compound contained in the volatile organic compound-containing water vapor K becomes less than a certain value until a certain time elapses, or the temperature of the volatile organic compound-containing water vapor K exceeds a certain value. Do until it becomes. In particular, since it is difficult to measure the content of volatile organic compounds in water vapor in real time, it is desirable to make a judgment based on time or temperature. This is because if the desorption proceeds sufficiently, the temperature of the volatile organic compound-containing water vapor K sufficiently approaches the temperature of the original desorption water vapor F.

  In order to finish the desorption, the valve 23 of the water vapor supply line 21 is closed, and the upper supply port 24a is also closed (S109). However, the lower supply port 25a is left open. In this state, the process waits until the adsorption process in the adsorption tower 11b is completed (S110).

  When the adsorption in the adsorption tower 11b is completed, the inlet 13b is closed, the inlet 13a is opened, and the volatile organic compound-containing gas A is introduced into the adsorption tower 11a from the inlet 13a to be absorbed in the adsorption tower 11a. Adsorption is started (S111). However, for the adsorption tower 11b that has completed the adsorption, the upper supply port 24b is closed together with the introduction port 13b being closed, but the bottom supply port 25b is opened (S112).

  Thereby, in the adsorption tower 11a, since the discharge port 15a remains closed and the supply port 25a is vacant, the high-temperature residual desorption water vapor remaining in the adsorption tower 11a is converted into the volatile organic compound-containing gas A. And is transferred from the supply port 25a (S113). The residual desorbed water vapor transferred is reversely fed from the supply port 25a to the branch point 22, and then forwarded from the branch point 22 to the supply port 25b, and transferred into the adsorption tower 11b from the supply port 25b (S114). . Thus, the remaining desorbed water vapor moves to the adsorption tower 11b for each amount of heat held in the adsorption tower 11a. Since the inside of the adsorption tower 11b is warmed by the remaining desorption water vapor remaining in the adsorption tower 11a, the waste of the desorption water vapor F introduced into the adsorption tower 11b at the start of desorption is reduced. At this time, the valve 23 of the water vapor supply line 21 is closed.

Here, the reason why the valve on the bottom supply port 25b is opened is that if only the valve on the upper supply port 24b is opened, a large amount of organic solvent may be desorbed by residual water vapor, which may hinder leveling. is there. If residual water vapor is transferred from the bottom, this amount of heat is used exclusively to warm the entire adsorption layer and contributes little to desorption. That is, it does not hinder the above leveling.
Even when there are a plurality of supply ports in the height direction, it is better to avoid opening only the supply port closest to the supply port (that is, the uppermost).

  It is preferable not to thoroughly carry out the transfer of the residual desorption water vapor but to terminate it halfway. Since the remaining desorbed water vapor is gradually cooled, when it comes to the end of the transfer, there is no more heat to move in and out for reuse. Even if such residual escape steam is transferred into the adsorption tower 11b, the effect of preheating is insufficient, and it is more efficient to introduce the desorption steam F as it is. For this reason, in the adsorption tower 11a, the temperature is continuously measured with a temperature sensor provided in either the tower or the supply port piping, and a constant temperature at which the thermal efficiency is considered to deteriorate even if the residual desorption water vapor is transferred in and out. In order to stop the transfer, the supply port 25a is closed, the discharge port 15a is opened, and the gas is discharged from the discharge port 15a (S115). The gas discharged at this time is highly likely to be a mixture of the treated gas B and the remaining desorbed water vapor, and the content of the treated gas B increases thereafter. The remaining desorbed water vapor has already condensed most of the water vapor that it originally had and becomes water, and is discharged from the drain outlet at the bottom. It rarely happens. Thereafter, the adsorption step is continued in the adsorption tower 11a until a condition such as a fixed time elapses as described above (S116 ~).

  The rate of decrease in the temperature of the remaining desorption water vapor is considered to be substantially constant if the outside air temperature is the same. Therefore, once the temperature at the time of transfer of the remaining desorption water vapor is measured with a temperature sensor, The time until the temperature is lowered may be measured, and the second and subsequent times may be set so that the transfer is completed when the certain time has elapsed. In addition, a temperature sensor may be provided on the upper surface of the adsorption tower 11b for transferring the remaining desorbed water vapor, and the transfer-in / out may be stopped when the temperature reaches a certain level. This is particularly effective when the residual desorption water vapor is transferred from the upper part of the adsorption tower. That is, since the desorption does not proceed unexpectedly due to the remaining desorption water vapor, leveling is not hindered. In addition, when residual desorption water vapor and desorption water vapor F are mixed and transferred as in the embodiment described later, the total amount of desorption water vapor supplied into the tower increases, but by interlocking with the temperature sensor, Leveling can be performed under the same operating conditions regardless of the presence or absence of this residual desorption water vapor.

On the other hand, in the adsorption tower 11b, the upper supply port 24b is opened and the lower supply port 25b is temporarily closed (S115). At the same time, by opening the valve 23 of the water vapor supply line 21, the desorption water vapor F supplied from the water vapor supply line 21 is supplied from the upper supply port 24 b, and the upper portion of the adsorption layer 12 b is desorbed. Is started (S116). Thereafter, the supply port 25b is opened (S117), and desorption is caused in the entire adsorption layer 12b (S118), thereby preventing the volatile organic compound from being desorbed all at once from the entire adsorption layer 12b. Aim the level.
The desorption of the entire adsorption layer is started by opening the valve of the supply port 25b at the bottom (S117). However, since the lower stage of the adsorption layer is warmed by residual water vapor from the bottom surface, desorption occurs quickly, and the time of the desorption process It will be shortened.

  Subsequent progress after the desorption in the adsorption tower 11b (S119-) is the same only after the relationship between the above-mentioned S109 and the adsorption towers 11a and 11b is reversed. That is, the remaining desorbed water vapor remaining in the adsorption tower 11 b is pushed out to the volatile organic compound-containing gas A introduced from the inlet 13 b, transferred from the bottom supply port 25 b, and sent back to the branch point 22. By being transferred from the supply port 25a of the adsorption tower 11a, most of the heat remaining in the adsorption tower 11b moves to the adsorption tower 11a.

  By carrying out the transfer of residual desorbed water vapor remaining at the completion of desorption at the end of desorption and at the start of adsorption, the amount of water vapor and heat is not wasted, and high temperature water vapor is discharged into the atmosphere. And the generation of white smoke can be prevented.

  In the above embodiment, when the residual desorption water vapor is transferred in and out, the valve 23 is closed to temporarily stop the supply of new desorption water vapor. This is to prevent the remaining desorbed water vapor from flowing back to the water vapor source. However, if this valve 23 is not only on / off but also a valve whose flow rate can be adjusted, it is possible to supply new desorption water vapor while preventing the remaining desorption water vapor from flowing back to the water vapor source during transfer. , Prompt transfer and start of desorption can be performed. This second embodiment will be described based on the first embodiment.

  The implementation procedure of the second embodiment will be described together with the flow of FIG. 3 and the status transition table of Table 2. S100 to S111 are the same as those of the first embodiment, but S112 to S116 in FIG. 2 and Table 1 are changed, and are denoted as S112a to S116a, respectively. That is, when the adsorption in the adsorption tower 11b is finished and the adsorption in the adsorption tower 11a is started (S111), both the upper supply port 24b and the bottom supply port 25b of the adsorption tower 11b after the adsorption are completed. And the valve 23 is opened to supply new desorption water vapor from the water vapor source (S112a). However, the flow rate of the valve 23 and the valve of the upper supply port 24b can be reduced, and neither of them is fully opened and needs to be adjusted appropriately.

  The remaining desorbed water vapor remaining in the adsorption tower 11a is transferred from the supply port 25a (S113a, as in the first embodiment S113). The transferred desorption water vapor that has been transferred and the new desorption water vapor F supplied from the water vapor supply line 21 through the valve 23 are mixed in the vicinity of the branch point 22, and are supplied from the upper supply port 24 b and the bottom supply port 25 b. Is supplied into the adsorption tower 11b (S114a). However, the flow rate passing through the valve 23 that is a control valve is appropriately adjusted so that the mixed water vapor does not flow back to the valve 23. Further, the valve of the upper supply port 24b is used as a control valve, or a control valve is provided between the branch point 22 and the supply port 24b, or the control valve at any position is connected to the upper supply port 24b. The amount of water vapor flowing in is reduced and adjusted so that water vapor is preferentially supplied to the supply port 25b at the bottom. Thereby, water vapor | steam which is not excessive is supplied to the upper supply port 24b, desorption can be started rapidly, and the time required for desorption can be shortened rather than 1st embodiment. In parallel with this, the portion below the supply port 24b at the top of the adsorption layer 12b is sufficiently warmed by the residual desorption water vapor that has been transferred in and the new desorption water vapor F. Thereafter, the valve of the bottom supply port 25b is once closed (S115a), but since desorption has already progressed in the upper part of the adsorption layer 12b (S116a), the time loss until the desorption starts in the lower part is reduced, and adsorption is performed. Subsequent total desorption (S117, S118) is started with the layer 12b sufficiently warmed. Thereby, since the volatile organic compound adsorbed on the lower part of the adsorption layer 12b is desorbed earlier than in the first embodiment, until the volatile organic compound desorbed from the upper part of the adsorption layer 12b is followed. The amount of the volatile organic compound is further leveled as compared with the first embodiment as a whole.

  The same change as described above is also performed at the time of transfer to the adsorption tower 11a (S122a to S125a).

Next, an applied embodiment when the configuration of the organic compound processing apparatus is different will be described.
Even when the organic compound processing apparatus does not have the valve 23 in the water vapor supply line 21, the present invention can be implemented. That is, even if the desorption water vapor F is continuously supplied from the water vapor supply line 21, when the volatile organic compound-containing gas A is supplied to the adsorption tower 11a (or 11b) at a pressure exceeding the supply pressure, The residual desorption water vapor that is pushed out and pushed out pushes back the supplied desorption water vapor F, and the residual desorption water vapor can be fed back from the supply port 25a (or 25b) to the branch point 22. The residual desorption water vapor that has reached the branch point 22 and the new desorption water vapor are mixed in the same manner as in the second embodiment and are forwarded from the branch point 22 to the supply port 25b (or 25a), and the adsorption tower 11b. The residual desorption water vapor can be transferred into (or 11a). On the other hand, in the steam supply line 21 upstream from the branch point 22, the flow of the desorption water vapor F does not branch. Therefore, even if the supply pressure increases and the reverse flow of the remaining desorption water vapor proceeds to some extent, the desorption water vapor F is halfway. The backflow stops by the pressure of and the backflow to the water vapor supply source can be prevented. By adopting such a configuration without the valve 23, the number of parts can be reduced and the apparatus can be simplified, and the number of valves to be controlled can be reduced, so that the control mechanism can be simplified.

  Even when the valve 23 is not provided, the upper supply port 24a (or 24b) may be opened while being throttled by the control valve at the time of transfer as in the second embodiment.

  In practicing the present invention, the adsorption tower 11 included in the organic compound processing apparatus is not limited to two, and can be implemented even when three or more are provided in parallel. By adsorbing and desorbing three or more adsorption towers at different timings, the adsorption process, which is the object of the processing apparatus, can proceed stably. At the start of adsorption, a certain amount of time and pressure is required for the volatile organic compound-containing gas A to permeate the adsorption layer 12 and pressure loss occurs, so that the adsorption proceeds promptly with 100% efficiency. is not. By compensating the pressure loss at the start of the adsorption by another adsorption tower, the adsorption process of the adsorption tower, which is the original purpose, can proceed stably. Then, if the residual desorption water vapor remaining at the completion of desorption in one adsorption tower is transferred at the start of adsorption and transferred to the adsorption tower for the next desorption, the above-mentioned adsorption tower is in the case of two groups. Similarly to the embodiment, the heat accumulated in one adsorption tower can be used effectively, and the release of residual desorbed water vapor can be prevented to prevent the generation of white smoke.

  When three or more adsorption towers are operated in parallel, residual desorbed water vapor may be transferred from one adsorption tower that has been desorbed to another adsorption tower that has already been desorbed. In this case, it cannot be preheated before the start of desorption, but the remaining desorbed water vapor is not released into the atmosphere and can be used for desorption together with new desorbed water vapor F. The generation of white smoke due to the release of water vapor outside the atmosphere can also be suppressed.

  As a supply source for supplying water vapor to the organic compound processing apparatus for carrying out the present invention, if there is an external water vapor generation source, it may be used. When the generation source of the volatile organic compound-containing gas A generates heat, water may be evaporated by the heat to obtain the desorption water vapor F. On the other hand, when supplying steam in the apparatus as an organic compound processing apparatus and completing the apparatus, a combustion furnace 31 that burns fuel to generate heat and water vapor F that desorbs water by the heat of the combustion furnace. A heat exchanger 32 is preferably provided. The block diagram of the organic compound processing apparatus in that case is shown in FIG.

  The combustion furnace 31 is for generating heat for generating the desorption water vapor F and has a fuel supply port 42 for supplying the fuel D therefor. 11 (11a, 11b) also includes a water vapor supply port 43 for supplying the organic compound-containing water vapor K sent from the outlet 26 (26a, 26b). Of course, the combustion furnace 31 also has a burner and a chimney (both not shown). Furthermore, it has a combustion furnace temperature sensor 44 for measuring the internal temperature. Heat generated in the combustion furnace 31 is supplied to the heat exchanger 32.

  The heat exchanger 32 includes a circulation port 51 that supplies water E that is a source of water vapor, and heats the water E to generate desorption water vapor F. The generated desorption water vapor F is supplied from the water vapor generation port 52 through the water vapor supply line 21 to the supply ports 24 and 25 of the adsorption tower 11 before the branch point 22 that is divided into the adsorption towers 11a and 11b. In addition, a circulation branch 53 is provided, and one of the branches forms a circulation path 54 that circulates to the heat exchanger 32. The circulation path 54 has a function of spraying water E and is connected to the heat exchanger 32 through the circulation port 51. Until the desorption water vapor F to be generated reaches a sufficiently high temperature, the generated water vapor goes around the circulation path 54 and is not discharged to the adsorption tower 11 or the outside, thereby improving the thermal efficiency. The heat exchanger 32 has a water vapor temperature sensor 56 for measuring the internal temperature in order to adjust the temperature of the generated water vapor.

  Another discharge branch 55 is provided between the other branch of the circulation 53 and the branch point 22 that branches to the adsorption towers 11a and 11b. One of the discharge branches 55 is connected to an opening 59 to the atmosphere so that it can be released into the atmosphere when the internal pressure in the circulation path 54 becomes excessive or the desorption water vapor F is left. A valve that can be opened and closed as necessary is provided. In particular, when the present invention is carried out without providing the valve 23, it acts as a safety valve that discharges when the internal pressure of the circulation path 54 or the like approaches the allowable limit due to the residual desorbed water vapor that is fed back.

A volatile organic compound-containing gas B post-treatment gas D fuel E water F desorption water vapor K volatile organic compound-containing water vapor 11, 11a, 11b adsorption towers 12, 12a, 12b adsorption layers 13, 13a, 13b inlets 15, 15a , 15b Discharge port 20, 20a, 20b Perforated plate 21 Steam supply line 22 Branch point 23 Valves 24, 24a, 24b Supply port 25, 25a, 25b Supply port 26, 26a, 26b Supply port 31 Combustion furnace 32 Heat exchanger 35 Release Branch 42 Fuel supply port 43 Water vapor supply port 44 Combustion furnace temperature sensor 51 Circulation port 52 Water vapor generation port 53 Circulation branch 54 Circulation path 55 Discharge branch 56 Water vapor temperature sensor 59 Opening port

Claims (5)

A plurality of adsorption towers each having an adsorption layer filled with an adsorbent for adsorbing volatile organic compounds, and a gas containing a volatile organic compound is introduced into at least one of the adsorption towers; After the organic compound is adsorbed on the adsorbent and the content is reduced, the treated gas is discharged,
A method of controlling an organic compound treatment apparatus, which is used for adsorption again after introducing desorption water vapor in order to the adsorption tower after performing adsorption and desorbing volatile organic compounds from the adsorbent,
When the desorption is completed, the remaining desorption water vapor remaining in the adsorption tower is transferred, and transferred to another adsorption tower to be desorbed, another adsorption tower in which desorption has started, or both. A method for operating an organic compound processing apparatus, characterized by: The water vapor supply line that supplies the desorption water vapor to the adsorption tower has a branch point that is shared partway from the supply source and is divided toward the individual adsorption tower,
The transfer of the remaining desorbed water vapor into the other adsorption tower, the desorption water vapor supply port of one of the adsorption towers as a discharge port for transfer, from there the water vapor supply line back to the branch point, The operation method of the organic compound processing apparatus according to claim 1, wherein the operation is carried out by sequentially feeding from the branch point to a desorption water vapor supply port serving as a supply port for transfer of the other adsorption tower.   The desorption water vapor supply ports are present in a plurality of stages in the height direction of the adsorption tower, and the desorption water vapor supply ports other than at least the uppermost stage are used as the supply ports for the transfer. The operation method of the organic compound processing apparatus according to claim 2. There is no valve that prevents backflow between the desorption water vapor source and the branch point,
The operation method of the organic compound processing apparatus according to claim 2 or 3, wherein a reverse supply of the remaining desorption water vapor to the supply source is prevented by continuous supply of the desorption water vapor from the supply source.   The transfer of the remaining desorbed water vapor remaining in the one adsorption tower is determined in advance from the time when the water vapor temperature at the outlet for transfer in the one adsorption tower falls below a predetermined temperature, or from the start of the transfer. 5. The method of operating an organic compound processing apparatus according to claim 1, wherein the operation is terminated when a predetermined time has elapsed.

Images