JP3164323U - VOC fixed bed type adsorption / desorption device - Google Patents

Abstract

A VOC fixed bed type adsorption / desorption device for purifying exhaust gas containing a volatile organic compound is provided. SOLUTION: An adsorbent 5 is loaded into a thin metal pipe 9 and a plurality of thin metal adsorption cylinders 6 formed into a narrow adsorption tower shape are passed through upper and lower partition plates 11 and 12, respectively. The upper and lower portions of a plurality of metal thin-diameter adsorption cylinders 6 are hermetically disposed on the upper and lower partition plates 11 and 12, and the upper and lower partition plates 11 and 12 are hermetically disposed in the adsorption tower 3. The exhaust gas containing VOC is passed through the plurality of metal fine-diameter adsorption cylinders 6 so that the VOC in the exhaust gas is adsorbed on the adsorbent 5 and removed, and the fine metal particles of the plurality of cylinders are removed. The adsorbent 5 is connected to the upper and lower partition plates 11 and 12 so that the VOC is removed from the adsorbent 5 adsorbed by heating the diameter adsorbing cylinder 6 and removed, so that the adsorbent 5 is VOC. When the adsorption capacity of the adsorbent 5 is reduced by sufficiently adsorbing 6 heat treatment by supplying a heating medium from between the upper and lower partition plates 11 and 12. [Selection] Figure 1

Description

  The present invention relates to a VOC fixed bed type adsorption / desorption device for purifying exhaust gas containing a volatile organic compound in the field of pollution prevention.

  Volatile organic compounds (VOC) such as toluene, xylene, and trichlorethylene, which are considered as one of the causative substances of suspended particulate matter and photochemical oxidants, are discharged in the painting process, cleaning process, printing process, etc. The Air Pollution Control Law has been implemented to reduce VOC emissions, and measures to reduce VOC emissions such as recovery, regeneration, sealing, combustion / decomposition, and substance substitution are being implemented.

  The present invention is one of the VOC emission suppression measures described above, and is based on a fixed bed adsorption method using activated carbon or the like. As is well known, the fixed bed adsorption method using activated carbon recovers the VOC content from the exhaust gas, recycles it as a solvent, and reuses the exhaust gas as a fixed bed in which an adsorbent such as activated carbon is packed in the adsorption tower. The VOC flows into the adsorbent and is sufficiently adsorbed to remove it.

  If the adsorbent sufficiently adsorbs VOC, the adsorbing capacity decreases, so that it is necessary to desorb VOC or replace the adsorbent. Normally, steam is introduced, but the desorption gas generated at that time is introduced into the condenser together with a large amount of steam, and the VOC is cooled and recovered. For example, Japanese Patent Laid-Open Nos. 2001-149740 and 2001-179041 have been proposed.

  However, the agglomeration time due to the desorption of VOC takes 1 to 5 hours (first run) and the VOC residual rate of the adsorbent is 10 to 40%, and further, the moisture condensed from the steam and the recovered VOC Separation treatment was also necessary.

  The present invention has been made in view of the above points, and in order to solve the above-mentioned problems, exhaust gas containing a volatile organic compound (VOC) is passed through an adsorption tower loaded with an adsorbent to exhaust gas. VOC fixed bed type adsorption / desorption device that adsorbs the VOC to the adsorbent and removes it, and adsorbs the VOC sufficiently by adsorbing the VOC to the adsorbent to reduce the capacity of the adsorbent. In this case, an adsorbent is loaded into a thin metal pipe and a plurality of thin metal adsorption cylinders formed in a thin adsorption tower shape are passed through the upper and lower partition plates, respectively. The upper and lower portions of the diameter adsorption cylinder are hermetically disposed on the upper and lower partition plates, and the upper and lower partition plates are hermetically disposed in the adsorption tower so that the VOC-containing exhaust gas is discharged into the fine metal plates of the plurality of cylinders. The VOC in the exhaust gas is adsorbed by the adsorbent through the inside of the diameter adsorption cylinder. A heating medium can be freely supplied between the upper and lower partition plates so as to remove and remove the VOC from the adsorbent formed by heating and adsorbing the plurality of metal small-diameter adsorption cylinders. When the adsorbent adsorbs the VOC sufficiently due to pipe connection and the capacity of the adsorbent decreases, the metal thin-diameter adsorption cylinder is heated by supplying a heating medium between the upper and lower partition plates. An object of the present invention is to provide a VOC fixed bed type adsorption / desorption device characterized by being formed.

  Another object of the present invention is to provide a VOC fixed bed type adsorption / desorption characterized in that a fine mesh wire mesh is attached to the bottom of a metal thin diameter adsorption cylinder.

  Furthermore, another object of the present invention is to provide a VOC fixed bed type adsorption / desorption device characterized in that a concentration sensor or / and a temperature sensor are arranged in at least one small diameter adsorption cylinder.

  Furthermore, 50 to 1000 cylinders of metal small diameter adsorption cylinders are arranged on a partition plate, and a heating medium of steam is supplied to heat the metal small diameter adsorption cylinders. The present invention provides a VOC fixed bed type adsorption / desorption device.

  In the present invention, exhaust gas containing a volatile organic compound (VOC) is passed through an adsorption tower loaded with an adsorbent so that the VOC in the exhaust gas is adsorbed on the adsorbent and removed to sufficiently absorb the VOC in the adsorbent. Is a VOC fixed bed type adsorption / desorption device that heat-treats the adsorbent and desorbs the VOC when the adsorbent capacity is reduced by adsorbing to the metal, and adsorbing the adsorbent into a metal small diameter tube The upper and lower portions of the plurality of metal thin-diameter adsorption cylinders are hermetically disposed on the upper and lower partition plates in a state where the plurality of metal thin-diameter adsorption cylinders formed in a tower shape pass through the upper and lower partition plates, respectively. The upper and lower partition plates are hermetically arranged in the adsorption tower, and the exhaust gas containing VOC is passed through the above-mentioned metal thin-diameter adsorption cylinders to remove the VOC in the exhaust gas by adsorbing to the adsorbent. Metal thin diameter adsorption cylinder by forming to process Collecting to form a fixed bed type adsorption tower, exhaust gas containing VOC can be passed through the small diameter adsorption cylinder of each metal and adsorbed on the adsorbent to remove the VOC. Can be processed.

  Then, a heating medium can be freely supplied and connected between the upper and lower partition plates so as to remove and remove the VOC from the adsorbent adsorbed by heating the plurality of small metal adsorption cylinders. When the adsorbent sufficiently adsorbs VOC and the capacity of the adsorbent is reduced, the metal thin-diameter adsorption cylinder is formed by supplying a heating medium from between the upper and lower partition plates and performing heat treatment. When the steam heating medium is fed into the adsorption tower, the steam heating medium uniformly contacts the entire outer surface of the metal small-diameter adsorption cylinder loaded with the adsorbent adsorbing VOC, and transfers heat. VOC adsorbed on the adsorbent in the small-diameter adsorption cylinder becomes a boiling state in a short time, evaporates, desorbs from the adsorbent, flows out of the metal small-diameter adsorption cylinder, and passes through the condenser in a short time. It can be recovered and the VOC remaining rate The recovery efficiency can be improved by reducing it to 5 to 10%, and there is no need to separate the steam from the condensed water in the conventional heating medium, improving the quality accuracy of the recovered product, saving space and simplifying the equipment. Is removed.

  Further, by attaching a fine mesh wire mesh to the bottom of the metal small diameter adsorption cylinder, it is possible to attach and hold an adsorbent such as activated carbon to the small diameter adsorption cylinder, and the exhaust gas containing VOC as described above Can be purified.

  Furthermore, by disposing a concentration sensor or / and a temperature sensor in at least one small-diameter adsorption cylinder, the concentration sensor can detect the concentration of VOC in the small-diameter adsorption cylinder. It is possible to detect that VOC is adsorbed in a saturated state on the adsorbent in the metal small-diameter adsorption cylinder, and it is possible to efficiently purify the exhaust gas containing VOC, and the concentration sensor in the small-diameter adsorption cylinder or / And the temperature sensor can accurately control the supply and stop of the steam heating medium, and the VOC is efficiently desorbed from the adsorbent adsorbed by heating and adsorbing the thin metal adsorption cylinder. It can be recovered.

  Furthermore, by arranging 50 to 1000 cylinders of metal small diameter adsorption cylinders on the partition plate and supplying the steam heating medium to heat the metal small diameter adsorption cylinders, Thus, the exhaust gas containing VOC can be efficiently processed by steam heating.

Schematic for explanation of the VOC adsorption treatment state of the exhaust gas of one embodiment of the present invention, The side sectional view which arranged the thin diameter adsorption cylinder of the VOC adsorption / desorption part same as the above, Schematic for explanation of the VOC desorption processing state as above, An enlarged vertical sectional view for explanation (a) and an enlarged flat sectional view ((b)) of the thin-diameter adsorption cylinder part of the VOC adsorption / desorption process same as above.

  The VOC fixed bed type adsorption / desorption device of the present invention allows the exhaust gas containing a volatile organic compound (VOC) to pass through an adsorption tower loaded with an adsorbent to adsorb the VOC in the exhaust gas to the adsorbent and remove it. When the VOC is sufficiently adsorbed on the adsorbent and the capacity of the adsorbent decreases, the VOC fixed bed type adsorption / desorption apparatus heat-treats the adsorbent and desorbs the VOC. The upper and lower parts of the multiple metal thin-diameter adsorption cylinders are hermetically sealed in the upper and lower portions by passing through the upper and lower partition plates, respectively. In addition to being disposed on the partition plate, the upper and lower partition plates are hermetically disposed in the adsorption tower, and the exhaust gas containing VOC is allowed to pass through the fine metal adsorption cylinders of the plurality of cylinders so that the VOC in the exhaust gas. Is formed by adsorbing to the adsorbent and removing it. A heating medium is freely connected to the upper and lower partition plates so that the VOC is desorbed and removed from the adsorbent adsorbed by heating several thin metal adsorption cylinders, and the adsorbent is VOC. When the capacity of the adsorbent is reduced by sufficiently adsorbing the adsorbent, the metal thin-diameter adsorption cylinder is formed so as to be heated by supplying a heating medium between the upper and lower partition plates.

  As shown in FIGS. 1 to 3, the VOC fixed bed type adsorption / desorption device 1 is a fixed bed type exhaust gas containing a volatile organic compound (VOC) such as toluene, xylene, trichlorethylene or the like through an inflow pipe 2 having a predetermined diameter. The small-diameter adsorption cylinders 6 loaded with the adsorbents 5 are gathered around the central axis of the adsorption tower 3 as if the small-diameter adsorption towers were collected. The adsorbent 5 is passed through each of the small-diameter adsorption cylinders 6 to purify the VOC in the exhaust gas by adsorbing the adsorbent 5 and removing it from the outlet 7. 8 is allowed to flow out.

  As shown in FIGS. 1 and 2, the small-diameter adsorption cylinder 6 is formed by loading an adsorbent 5 on a metal thin-diameter tube 9 to form a small-diameter adsorption tower. For example, carbon steel pipes, alloy steel pipes, stainless steel (SUS) steel pipes, and metal pipes such as titanium can be used, and stainless steel (SUS) steel pipes having corrosion resistance, durability, and availability are preferable. The diameter is 10 to 100 mm, preferably 10 to 50 mm, more preferably 10 to 30 mm, and the number is about 50 to 1000. The diameter, number, and length correspond to the treatment capacity of the adsorption tower 3. It can be determined as appropriate, and can be arranged in a lattice or zigzag pattern. It is to be noted that the thin tube 9 is preferably as thin as possible, and the adsorbent 5 can be loaded and held by attaching a metal mesh 10 of a predetermined mesh to the bottom.

  Further, as the adsorbent 5, granular, bead-like, fibrous, honeycomb-like activated carbon, zeolite, or the like can be used, and those having a shape and size that can be easily loaded into the small-diameter tube 9 and can be exchanged are preferable. Those having a diameter corresponding to 2 to 10 mm, particularly those corresponding to a diameter of 3 to 8 mm are preferable.

  As shown in FIG. 2, the upper and lower ends of the metal thin-diameter adsorption cylinder 6 are hermetically sealed so that the upper and lower ends thereof are perpendicular to the partition plates 11 and 12, as shown in FIG. The upper and lower partition plates 11 and 12 are disposed in an airtight manner in the substantially central portion of the adsorption tower 3 to dispose the VOC-containing exhaust gas to the above-mentioned multi-cylinder metal fine diameter. The VOCs in the exhaust gas are adsorbed to the adsorbents 5 that are loaded through the adsorption cylinders 6 and are removed.

  1 and 2, a heating medium such as steam can be freely supplied between the upper and lower partition plates 11 and 12 in which a plurality of thin metal adsorption cylinders 6 of the adsorption tower 3 are hermetically arranged. When the adsorbent 5 is sufficiently adsorbed by the pipe connection and the capacity of the adsorbent 5 is reduced, the adsorbent 5 is disposed in at least one small-diameter adsorption cylinder 6 and the outflow pipe 8 at the outlet 7 of the adsorption tower 3. When the concentration of the VOC is detected by the concentration sensors 13 and 14 such as semiconductors, when a predetermined concentration is reached, a heating medium such as steam is supplied so that the upper and lower portions of the metal small-diameter adsorption cylinders 6 are The entire outer peripheral surface is formed so as to be heated uniformly over the length. As the heating medium, steam is preferable because of its large heating capacity. Reference numerals 15 and 16 denote temperature sensors, which are appropriately arranged in at least one small-diameter adsorption cylinder 6 and in the adsorption tower 3 so as to detect the temperature of these parts, and the temperature of a heating medium such as steam. Control management and safety control management can be performed. It is preferable that the concentration sensor 13 and the temperature sensor 15 are disposed in the small diameter adsorption cylinder 6 so that the concentration and temperature in the small diameter adsorption cylinder 6 can be accurately detected. Both can be managed and can be monitored accurately.

As shown in FIGS. 1 and 3, open / close valves 17 and 18 are provided at the upper and lower inlets 4 and 7 of the adsorption tower 3, respectively. When supplying a heating medium such as steam, these open / close valves are provided. 17 and 18 are closed, and a heating medium such as steam of 0.3 to 1 Pa (3 to 10 Kg / cm ² ) and 100 to 150 ° C. is supplied from the heating medium supply port 19 on the side of the adsorption tower 3. Yes. The steam is preferably superheated steam, and can be obtained by heating steam generated by a boiler or the like with an electric heater heating device or the like of a sheathed heater. 20 is a heating medium outlet, 21 is a drain outlet, 22 is a condensing device, 23 is a vacuum pump, 24 is a recovery can, and a concentration sensor S is provided in the VOC outlet 25 of the adsorption tower 3, and each supply An automatic opening / closing valve or the like can be disposed on the opening, the discharging portion, etc. so as to be freely controlled.

  When the VOC adsorbed by the heat treatment with the heating medium is desorbed in this way, the concentration sensor 13 and S arranged at the VOC outlet 25 of the small diameter adsorption cylinder 6 and the adsorption tower 3 detect the concentration of VOC to be predetermined. When the concentration of γ is reached, the heating medium supply port 19 at the side is diverted to the adsorption tower 3 to introduce a cooling medium such as water or air to cool the metal small diameter adsorption cylinder 6. The removal treatment can be repeated by passing the exhaust gas containing VOC through the metal small-diameter adsorption cylinder 6 to adsorb the VOC in the exhaust gas to the adsorbent 5. If necessary, it can also be performed by timer setting.

  In the above description, the gist of the present invention has been described with one adsorbing tower 3 as a unit. However, based on the gist of the present invention, an appropriate number of adsorbing towers 3 are arranged in parallel according to the processing amount of exhaust gas. In other words, it is possible to implement an embodiment corresponding to the above.

  FIG. 1 and subsequent figures show an embodiment of the present invention. As shown in FIG. 1, the VOC fixed bed type adsorption / desorption device 1 causes exhaust gas containing a volatile organic compound (VOC) to flow from an inlet 4 of an adsorption tower 3 through an inflow pipe 2 having a predetermined diameter. The adsorption tower 3 is an adsorption tower body in which granular activated carbon adsorbents 3 to 8 mm in diameter are loaded into small diameter pipes 9 of stainless steel (SUS) pipes each having a diameter of 30 mm to collect metal small diameter adsorption cylinders 6. In this state, the VOC in the exhaust gas is adsorbed by the adsorbent 5 and removed, and then it is discharged from the outlet 7 through the outflow pipe 8.

  The metal thin-diameter adsorption cylinder 6 has a length of about 50 cm, and upper and lower ends thereof are staggered on partition plates 11 and 12 of a stainless steel (SUS) plate having a predetermined thickness as shown in FIGS. The upper and lower portions of a stainless steel (SUS) small-diameter pipe 9 are hermetically welded to the partition plates 11 and 12, respectively, and the upper and lower partition plates 11 and 12 are hermetically arranged in the adsorption tower 3. The VOC contained in the exhaust gas is adsorbed to the adsorbent 5 loaded by passing the exhaust gas containing VOC through the small diameter adsorption cylinders 6 of the metal and removed.

  The steam heating medium can be supplied freely from the heating medium supply port 19 on the side between the upper and lower partition plates 11 and 12 in which the plurality of metal thin-diameter adsorption cylinders 6 of the adsorption tower 3 are hermetically disposed. Concentration sensors 13 and 14 are disposed in at least one small-diameter adsorption cylinder 6 and in the outflow pipe 8 at the outlet 7 of the adsorption tower 3 to detect the concentration of VOC. Temperature sensors 15 and 16 are provided in the small-diameter adsorption cylinder 6 and the adsorption tower 3 so as to detect the temperature of these portions, and temperature control management and safety control management of a heating medium such as steam can be performed. I am doing so.

  As shown in FIG. 1, when exhaust gas containing VOC flows into the adsorption tower 3 formed in this way through the blower through exhaust gas containing VOC from the upper inlet 4, the exhaust gas is a plurality of metal small-diameter adsorption cylinders. The VOC in the exhaust gas passes through the inside of the exhaust gas 6 and is adsorbed and removed by the adsorbent 5 and flows out from the outlet 7 so that the exhaust gas can be purified.

Then, if the adsorbent 5 sufficiently adsorbs VOC and the capability of the adsorbent 5 is reduced by the concentration sensors 13 and 14 in the narrow diameter adsorption cylinder 6 and the outflow pipe 8 portion of the adsorption tower 3, respectively, The on / off valves 11 and 12 at the upper and lower inlets 4 and 7 of the tower 3 are closed, and the superheated steam of 0.3 Pa (3 Kg / cm ² ) and 130 ° C. is heated from the heating medium supply port 13 on the side of the adsorption tower 3. Supply heating medium.

  When the steam heating medium is fed into the adsorption tower 3, the outer peripheral surface of the metal small-diameter adsorption cylinder 6 loaded with the adsorbent 5 having adsorbed VOC is heated with steam. As shown in FIGS. 3 (a) and 3 (b), the steam heating medium uniformly contacts the entire outer peripheral surface of the metal thin-diameter adsorption cylinder 6 and transfers heat to the inside. The adsorbent 5 adsorbed VOC is boiled instantaneously or in a short time, evaporates, desorbs from the adsorbent 5, flows out of the metal small-diameter adsorption cylinder 6, and the condenser device 22 is discharged from the VOC discharge port 25. And can be recovered in the recovery can 24 in a short time. The residual ratio of VOC is reduced to 5 to 10%, and there is no need to separate the conventional steam heating medium from the condensed water, thereby improving and simplifying the recovery accuracy. At this time, if the inside of the small diameter adsorption cylinder 6 is sucked in a reduced pressure state by the vacuum pump 23, the VOC adsorbed on the adsorbent 5 in the metal small diameter adsorption cylinder 6 is brought into a boiling state in a short time. Thus, it can be evaporated and desorbed from the adsorbent and flow out of the metal small-diameter adsorption cylinder to be recovered in a short time.

  VOC adsorbed by heat treatment with steam is desorbed, detected by the concentration sensors 13 and S in the small diameter adsorption cylinder 6 and the VOC outlet 25 of the adsorption tower 3, and the desorption state of the VOC is confirmed to cool the air. The medium is introduced, the outer peripheral surface of the metal small diameter adsorption cylinder 6 is cooled with a cooling medium, and the exhaust gas containing VOC flows again into the adsorption tower 3 and passes through the small diameter adsorption cylinder 6 to be contained in the exhaust gas. The VOC is adsorbed on the adsorbent 5 and removed repeatedly. In this way, purification treatment of exhaust gas containing VOC can be carried out efficiently and sequentially.

  By making the metal small-diameter adsorption cylinder 6 of a small diameter, as shown in FIGS. 4A and 4B, the steam heating medium is a metal small-diameter adsorption loaded with the adsorbent 5 adsorbing VOC. Heat is transferred evenly in contact with the entire outer peripheral surface of the cylinder 6, and the VOC adsorbed on the adsorbent 5 in the metal small-diameter adsorption cylinder 6 becomes a boiling state in an instant or in a short time and evaporates to adsorb. Can be removed and discharged from the metal small diameter adsorption cylinder 6 and recovered efficiently in a short time. In the heating of the steam, the steam generated in the boiler or the like is heated with an electric heater heating device of a sheathed heater or the like, and high-temperature superheated steam of about 150 ° C. is preferable. Can be desorbed.

  Thus, in the past, it took 1 to 5 hours to recover VOC, but it can be processed in a short time such as several minutes to several tens of minutes, and exhaust gas removal processing can be performed efficiently in a short time. Can do.

  INDUSTRIAL APPLICABILITY The present invention can widely use exhaust gas containing a volatile organic compound generated in a painting process, a cleaning process, a printing process, etc. in the purification treatment field.

DESCRIPTION OF SYMBOLS 1 ... Adsorption / desorption apparatus 3 ... Adsorption tower 5 ... Adsorbent 6 ... Thin diameter adsorption cylinder 9 ... Thin diameter pipe 11, 12 ... Partition plate 13 ... Concentration sensor 15 ... Temperature sensor 19 ... Heating medium inflow port

JP 2001-149740 A JP 2001-179041 A

Claims (4)

The exhaust gas containing the volatile organic compound (VOC) is passed through the adsorption tower loaded with the adsorbent, and the VOC in the exhaust gas is adsorbed on the adsorbent to be removed, and the VOC is sufficiently adsorbed on the adsorbent. When the capacity of the adsorbent decreases, a VOC fixed bed type adsorption / desorption device that heats the adsorbent to desorb VOC,
A plurality of metal fine-diameter adsorption cylinders are formed by penetrating the upper and lower partition plates into a plurality of metal thin-diameter adsorption cylinders that are formed into a thin adsorption tower by loading an adsorbent into a metal thin-diameter pipe. The upper and lower parts are hermetically disposed on the upper and lower partition plates, and the upper and lower partition plates are hermetically disposed in the adsorption tower to exhaust the VOC-containing exhaust gas into the above-mentioned metal small-diameter adsorption cylinders. Is formed so that the VOC in the exhaust gas is adsorbed by the adsorbent and removed.
The adsorbent is connected to the upper and lower partition plates so that the heating medium can be freely removed from the adsorbent that has been adsorbed by heating the plurality of metal thin-diameter adsorption cylinders. The VOC is characterized in that when the VOC is sufficiently adsorbed and the capacity of the adsorbent is reduced, the metal thin-diameter adsorption cylinder is formed such that a heating medium is supplied from between the upper and lower partition plates for heat treatment. Fixed bed type adsorption / desorption device. 2. The VOC fixed bed type adsorption / desorption device according to claim 1, wherein a fine mesh wire net is attached to the bottom of the metal thin diameter adsorption cylinder. The VOC fixed bed type adsorption / desorption method according to claim 1 or 2, wherein a concentration sensor or / and a temperature sensor are disposed in at least one small-diameter adsorption cylinder. 4. The metal thin-diameter adsorption cylinder according to claim 1, wherein 50-1000 cylinders of the metal thin-diameter adsorption cylinder are arranged on a partition plate, and a heating medium of steam is supplied to heat the metal thin-diameter adsorption cylinder. A VOC fixed bed type adsorption / desorption device according to claim 1.

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