JP2011104505A - Voc removal device and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a VOC (Volatile Organic Compounds) removal device and VOC removal method, which are simple and inexpensive in initial costs or running costs. <P>SOLUTION: The VOC removal device 1 comprises an uptake means 13, 19, 36 for taking in oil sorbing the VOC in a body device 4, a depressurizing means 3, 44 for reducing atmospheric pressure in the body device 4, a separating means 12 for separating the VOC evaporated from the oil by depressurizing the inside of the body device 4, a compression means 3, 44 for liquidizing the evaporated VOC by compressing the inside of the body device 4, and a VOC discharge means 21 for discharging the liquidized VOC separately from the remaining oil. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a removal device and removal method for medium to low concentration VOCs emitted from organic solvents used in various printing facilities and painting facilities, and in particular, VOC is separately adsorbed in advance to the oil, The present invention relates to a VOC removal apparatus and method for separating and removing adsorbed VOC from oil.

  In the printing-related industry and the paint industry, there are many works using organic solvents, and there are about 200 kinds of VOC (Volatile Organic Compounds: Toluene, Xylene, Ethyl Acetate, etc.) Is contained as a solvent in paints, adhesives, inks, etc.). VOCs at work sites are not only harmful to workers, but they also cause photochemical smog when released outside the room, and have developed into social problems.

  Therefore, after April 2006, notification of VOC emission facilities to large prefectures is required for large-scale facilities, and improvements are made if they do not meet emission standards. Is now required.

  As a conventional technique for removing VOCs, for example, an organic solvent in exhaust gas is absorbed in an absorption liquid by an absorption tower, the absorption liquid is passed through a heat exchanger and heated to a predetermined temperature, and is then absorbed in the absorption liquid by a regeneration tower. The organic solvent and water contained in the solvent are reduced in pressure and separated from the absorption liquid, further led to a condenser to condense the organic solvent and water, and then separated into the organic solvent and water by the solvent separator (Patent Document 1) And a volatile organic substance absorption chamber and a discharge chamber are provided, air containing volatile organic substances is introduced into the absorption chamber, the inside of the absorption chamber is pressurized to absorb the volatile organic substance into the oil, and the oil is released. A volatile organic substance removal system (refer to Patent Document 2) that feeds into a chamber, depressurizes the inside of the discharge chamber, releases volatile organic substances from the oil, and discharges them outside the chamber is known.

JP-A-6-315613 JP 2008-229472 A

  However, in the solvent recovery apparatus of Patent Document 1 described above, a heat exchanger, a heater, a regeneration tower, and a condenser are used as an apparatus for separating the organic solvent in a process after the organic solvent is absorbed into the absorption liquid by the absorption tower. However, since equipment such as a solvent separator is required, there is a problem that it becomes a large-scale system. Furthermore, there is a problem that a heating process is required at the time of operation and the running cost becomes high.

  Further, in the volatile organic substance removal system described in Patent Document 2, since the separated volatile organic substance is in a gaseous state, a liquefaction device or the like is required to collect and store the volatile organic substance, which increases the cost. .

  The present invention has been made in view of, for example, the above-described problems. An object of the present invention is a simple system in which VOC is separately adsorbed on oil, and VOC adsorbed on the oil is separated and removed from the oil. An object of the present invention is to provide a VOC removal apparatus and a VOC removal method that can be recovered in a liquefied state with low cost and running cost.

  In order to solve the above-described problems, a first VOC removal apparatus of the present invention includes a taking-in means for taking in oil that has adsorbed VOC into a main body apparatus, a decompressing means for reducing the atmospheric pressure in the main body apparatus, and the main body apparatus. Separating means for separating VOC vaporized from the oil by depressurizing the inside, compression means for liquefying the vaporized VOC by compressing the inside of the main body device, and separate from the oil remaining the liquefied VOC And a VOC discharge means for discharging.

  According to the first VOC removal apparatus of the present invention, oil and VOC can be easily separated by reducing and compressing the inside of the main body apparatus, and the liquefied VOC can be discharged.

  In order to solve the above-described problem, a second VOC removal device of the present invention is the first VOC removal device of the present invention described above, wherein the decompression means and the compression means decompress and compress the inside of the cylinder. A piston that reciprocates in a direction, and a control unit that controls the supply of compressed air into the cylinder and controls the reciprocation of the piston, and the intake means has an oil suction hole formed in the cylinder. An oil chamber for storing oil sucked from the oil suction hole by sliding of the piston in the pressure-reducing direction, and closing the oil suction hole when a predetermined amount of oil is sucked from the oil suction hole A valve device, and the separation means includes a decompression chamber for storing VOC vaporized from oil in the oil chamber by sliding of the piston in the decompression direction, and discharging the VOC Stage, the liquefied the VOC was the vaporizing by sliding of the piston in the compression direction, characterized in that it comprises a VOC discharge hole for discharging the VOC was liquefier outside the cylinder.

  According to the second VOC removal device of the present invention, the oil is sucked and the VOC is separated and liquefied by the VOC vaporization with a simple structure consisting of a cylinder and a piston and reciprocating movement of the piston for one stroke. VOC can be discharged.

  In order to solve the above problems, a third VOC removal device of the present invention is the second VOC removal device of the present invention described above, wherein the piston is a decompression piston that reciprocates in the decompression chamber; An oil suction piston that reciprocates in the oil chamber by reciprocating the piston shaft along a hollow portion formed in the piston shaft of the pressure reducing piston, and the pressure reducing piston is an anti-oil suction piston. When the space between the pressure reducing piston and the oil suction piston becomes negative pressure, the oil suction piston slides to the pressure reducing piston side for a predetermined length, and the valve device Closes the oil suction hole, and the amount of oil sucked from the oil suction hole into the oil chamber is set to a predetermined amount.

  According to the third VOC removing device of the present invention, the inside of the cylinder is depressurized by sliding of the decompression piston, and the oil suction amount is set to a predetermined amount by sliding the oil suction piston shaft for a predetermined length. . That is, the oil suction amount can be easily set by regulating the displacement amount of the oil suction piston.

  In order to solve the above problems, a fourth VOC removal device of the present invention is the above-described third VOC removal device of the present invention, wherein the oil suction piston includes the oil chamber and the decompression chamber. A VOC vent hole is provided so as to be able to communicate, and the valve device is slidably fitted to the outer periphery of the extension portion of the piston shaft of the oil suction piston, and the VOC vent hole opening / closing valve capable of opening and closing the VOC vent hole. An oil suction hole opening / closing valve capable of opening and closing the oil suction hole, a flange provided at the tip of the extension, and a compression spring interposed between the flange and the oil suction hole opening / closing valve. And the oil suction hole opening / closing valve closes the oil suction hole and the VOC ventilation hole opening / closing valve opens the VOC ventilation hole by sliding the decompression piston in the pressure reduction direction. To.

  According to the fourth VOC removal device of the present invention, the oil suction hole on-off valve closes the oil suction hole and stops the oil suction into the oil chamber only by sliding the pressure reducing piston in the pressure reducing direction. The VOC vent hole opening / closing valve opens the VOC vent hole so that the vaporized VOC can be collected in the decompression chamber.

  In order to solve the above problems, a fifth VOC removal device of the present invention is any one of the second to fourth VOC removal devices of the present invention described above, wherein the decompression chamber is disposed in the cylinder. A driving cylinder chamber formed adjacent to the side opposite to the oil chamber, and a driving piston that reciprocates in the driving cylinder chamber, the driving piston sharing the piston shaft of the decompression piston; The compressed air is alternately supplied to both sides of the drive piston, and the drive piston is reciprocated to reciprocate the decompression piston and the oil suction piston.

  According to the fifth VOC removing device of the present invention, the drive cylinder chamber is installed adjacent to the decompression chamber, and the piston shaft of the drive piston is shared with the decompression piston. The piston for pressure reduction and the piston for oil suction can be driven by reciprocating the motor. That is, since air is used for the driving power of the apparatus, the adjustment of the driving pressure becomes easy, and since no electricity is used, the VOC is not ignited and an explosion-proof measure can be taken.

  In order to solve the above-described problem, the sixth VOC removal device of the present invention is the fifth VOC removal device of the present invention described above, wherein the control unit is configured to perform a predetermined operation after the drive piston has finished the decompression step. Control is performed so that the compression process is started after a lapse of time.

  According to the sixth VOC removal apparatus of the present invention, it is possible to ensure time for the VOC adsorbed to the oil to evaporate from the oil, so that the VOC can be sufficiently vaporized.

In order to solve the above-described problem, the first VOC removal method of the present invention is such that compressed air is supplied to one side of the driving piston in the driving cylinder chamber, and the driving piston slides to the other side. A step of sliding a decompression piston sharing the piston axis with the drive piston in the same direction as the drive piston in the decompression chamber, and the decompression piston and the decompression piston as the decompression piston slides A step in which the oil suction piston slides in the same direction as the pressure reducing piston when the space between the piston and the oil suction piston having a piston shaft that reciprocates within the piston shaft of the piston becomes negative pressure; As the oil suction piston slides, the pressure inside the oil suction hole becomes negative, so that the oil adsorbing VOC is sucked into the oil chamber from the oil suction hole. When a predetermined amount of oil adsorbing VOC is sucked into the oil chamber from the oil suction hole, the oil suction hole is closed by the oil suction hole opening / closing valve, and the suction of oil into the oil chamber is stopped. And the further sliding of the driving piston further causes the pressure reducing piston and the oil suction piston to slide further in the same direction as the driving piston, and the VOC passage provided in the oil suction piston. The step of opening the pores by the VOC vent opening / closing valve, and the oil chamber and the decompression chamber communicate with each other through the opened VOC ventilation hole opening / closing valve, and the VOC adsorbed by the oil stored in the oil chamber Is vaporized, and the vaporized VOC is collected in the decompression chamber through the VOC communication hole;
Compressed air is supplied to the other side of the driving piston, and the driving piston is slid to one side, so that the pressure reducing piston and the oil suction piston slide in the same direction as the driving piston. The vaporized VOC in the decompression chamber is compressed and liquefied;
And a step of discharging the liquefied VOC from the VOC discharge hole to the outside of the decompression chamber.

  According to the first VOC removal method of the present invention, the VOC adsorbed on the oil can be easily separated and removed from the oil only by reciprocating the piston in the cylinder for one stroke, and the initial cost and running cost are reduced. Can be achieved.

  In order to solve the above-described problem, the second VOC removal method of the present invention includes a step in which the control unit controls the drive piston so that the drive piston moves to a compression step after a predetermined time has elapsed after the pressure reduction step. It is characterized by including.

  According to the second VOC removal method of the present invention, it is possible to secure a time for VOC adsorbed to the oil to evaporate from the oil, and thus VOC can be sufficiently vaporized.

  According to the present invention, the VOC adsorbed on the oil can be easily removed from the oil with a simple apparatus and method, and the initial cost and running cost can be reduced.

1 is an overall configuration diagram of a VOC removal device according to an embodiment of the present invention. It is a perspective view which decomposes | disassembles and shows the piston for oil suction and the valve apparatus of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state before the oil suction of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state at the time of the oil suction start of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state immediately after completion | finish of the oil suction of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state under pressure reduction of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state in which VOC is vaporized from oil in the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state of the compression process initial stage of the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows a state when the piston for pressure reduction falls to the piston for oil suction in the VOC removal apparatus which is embodiment of this invention. It is sectional drawing which shows the state which is discharging | emitting oil in the VOC removal apparatus which is embodiment of this invention. It is the A section enlarged view of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a VOC removal device according to an embodiment of the present invention. This VOC removal device 1 includes a main body device 4 mainly composed of a cylinder 2 and a piston 3, and a main body device 4. A compressed air supply device 5 that supplies compressed air, an oil container 6 that stores oil that has adsorbed VOC, a recovered oil container 7 that stores oil recovered from the main body device 4, and a liquefied VOC container that stores liquefied VOC 8 and.

  The oil that has adsorbed VOC is passed through the oil shower and cooled as described in, for example, Japanese Patent Laid-Open No. 50-69005 (chlorine organic solvent processing method). Or collected in the oil container 6 after being collected using a known technique such as a method in which the oil is dissolved in the container or a method in which the oil is put into the container and the gas pressure around the oil is increased to absorb the VOC. Is done. In the present embodiment, the cylinder 2 has an inner diameter of 90 mm and a height of 256 mm, for example, and the pressure of the compressed air is set to 0.3 MPa.

  The inside of the cylinder 2 is partitioned into three chambers, a driving cylinder chamber 11, a decompression chamber 12, and an oil chamber 13, in order from above by an upper partition wall 9 and a lower partition wall 10. A first compressed air intake port 14 that communicates between the drive cylinder chambers 11 is formed. Further, the upper partition wall 9 is provided with a shaft hole 15 in the center, and a second compressed air intake 16 communicating with the outside and the drive cylinder chamber 11 is formed around the shaft hole 15. In addition, a pressure adjusting hole 17 that communicates between the outside and the decompression chamber 12 is formed. Furthermore, an opening 18 is formed in the center of the lower partition 10.

  An oil suction hole 19 that communicates between the lower part of the oil chamber 13 and the outside is formed in the center of the bottom of the cylinder 2, and the upper end portion 19 a of the oil suction hole 19 is inclined and reduced in diameter. In addition, an oil discharge hole 20 is formed in the bottom of the cylinder portion 2 adjacent to the oil suction hole 19 so as to communicate between the lower portion of the oil chamber 13 and the outside. Further, on the outer peripheral wall surrounding the oil chamber 13 A VOC discharge hole 21 that communicates between the upper portion of the oil chamber 13 and the outside is formed.

  The piston 3 includes a driving piston 22 that reciprocates in the driving cylinder chamber 11, a decompression piston 23 that reciprocates in the decompression chamber 12, and an oil suction piston 24 that reciprocates in the oil chamber 13. Although not specifically illustrated, the pistons 22, 23, 24 have pistons on the outer circumference so that air leakage does not occur between the sliding surfaces of the chambers 11, 12, 13 and the pistons 22, 23, 24. A ring or the like is attached.

  The driving piston 22 and the decompression piston 23 share a piston shaft 25, and the piston shaft 25 passes through the shaft hole 15 of the upper partition wall 9. A hollow portion 26 is formed in a cylindrical shape in the piston shaft 25, and the hollow portion 26 communicates with the driving cylinder chamber 11 through a communication hole 27.

  The lower portion of the decompression piston 23 is reduced in diameter to form a pressing portion 28, and the pressing portion 28 can be loosely inserted into the opening 18 of the lower partition 10. Further, a shaft hole 29 communicating with the hollow portion 26 is formed at the center of the pressing portion 28, the shaft hole 29 has a smaller diameter than the hollow portion 26, and an in-shaft engagement portion 30 is formed around the lower end of the hollow portion 26. Is formed.

  The piston shaft 31 of the oil suction piston 24 is formed to be able to reciprocate along the hollow portion 26 through the shaft hole 29. The head 32 of the piston shaft 31 is expanded in diameter and can be hooked to the in-shaft engaging portion 30. A plurality of (for example, four) VOC vent holes 33 (for example, 3 to 4 mm in diameter) are provided around the piston shaft 31 of the oil suction piston 24 so that the decompression chamber 12 and the oil chamber 13 can communicate with each other. In addition, a recess 34 is formed at a position corresponding to the VOC vent hole 33 in the central portion on the lower surface side of the oil suction piston 24.

  An extension portion 35 of the piston shaft 31 projects downward on the lower surface side of the oil suction piston 24, and a valve device 36 is slidably fitted on the outer periphery of the extension portion 35. As shown well in FIG. 2, this valve device 36 is provided below the VOC vent opening / closing valve 37, which can open and close the VOC ventilation hole 33 and can be fitted in the recess 34. The oil suction hole opening / closing valve 38 which can open and close the oil suction hole 19 and can be fitted to the upper end portion 19a of the oil suction hole 19 is connected to the VOC vent hole opening / closing valve 37 and the oil suction hole opening / closing valve 38. The connecting portion 39, the flange portion 40 attached to the lower end of the extended portion 35, and the compression spring 41 interposed between the flange portion 40 and the oil suction hole opening / closing valve 38, 40 prevents the compression spring 41 from falling off.

  The compressed air supply device 5 is installed in a place isolated from the main body device 4, and includes a compressor 42, a controller 43, and a control unit 44 that controls the compressor 42 and the controller 43. The controller 43 is provided with an electric first three-way solenoid valve SV1 and a second three-way solenoid valve SV2. The first three-way solenoid valve SV1 is connected to the first compressed air via the hose 51. Connected to the intake port 14, the second three-way solenoid valve SV <b> 2 is connected to the second compressed air intake port 16 via the hose 52. When supplying the compressed air into the cylinder 2 through one of the three-way solenoid valves, the control unit 44 supplies the air on the opposite side of the driving piston 22 in the cylinder 2 from the other three-way solenoid valve. Control to release to the outside.

  The oil container 6 is connected to the oil suction hole 19 via a first check valve 45 and a hose 48, and the first check valve 45 only flows from the oil container 6 toward the oil suction hole 19. Allow. The recovered oil container 7 is connected to the oil discharge hole 20 via a second check valve 46 and a hose 49, and the second check valve 46 extends from the oil discharge hole 20 toward the recovered oil container 7. Only distribution is allowed. Furthermore, the liquefied VOC container 8 is connected to the VOC discharge hole 21 via the third check valve 47 and the hose 50, and the third check valve 47 extends from the VOC discharge hole 21 toward the liquefied VOC container 8. Only distribution is allowed. By installing check valves 45, 46 and 47 in the oil suction hole 19, the oil discharge hole 20 and the VOC discharge hole 21 in this way, oil, VOC and the like can be obtained during the decompression process and the compression process in the cylinder 2. Unnecessary suction or leakage can be prevented.

  Next, a VOC removal method according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 is a cross-sectional view showing a state before the oil is sucked into the oil chamber 13, and the compressed air is supplied from the compressor 42 shown in FIG. 1 to the NC (normally closed port) of the second three-way solenoid valve SV2. com (common port), when supplied from the second compressed air intake 16 into the driving cylinder chamber 11 below the driving piston 22, the driving piston 22 is pressed by the compressed air. The inside of the driving cylinder chamber 11 slides upward, and the decompression piston 23 slides upward in the decompression chamber 12 as the driving piston 22 slides upward. As a result, the space between the pressure reducing piston 23 and the oil suction piston 24 is increased, and the upper portion of the oil chamber 13 is in a negative pressure state.

  At this time, the air in the drive cylinder chamber 11 on the upper side of the drive piston 22 passes through the first compressed air intake port 14, and the NO (1) of the first three-way solenoid valve SV1 in the controller 43 shown in FIG. The air in the decompression chamber 12 above the decompression piston 23 is discharged to the outside through the pressure adjustment hole 17. At this time, since the hollow portion 26 in the piston shaft 25 communicates with the driving cylinder chamber 11 through the communication hole 27, the inside of the hollow portion 26 does not become negative pressure.

  FIG. 4 is a cross-sectional view showing a state when the oil having adsorbed VOC is started to be sucked into the oil chamber 13. When the upper portion of the oil chamber 13 is in a negative pressure state, the oil suction piston 24 is connected to the oil chamber 13. Slide up inside. As a result, the oil suction hole 19 and the inside of the hose 48 and the lower part of the oil chamber 13 are in a negative pressure state, and the oil adsorbing VOC is sucked from the oil container 6.

  At this time, since air has accumulated in the hose 48 in the first suction, it is necessary to reciprocate the oil suction piston 24 several times to discharge the air from the oil suction hole 19 and the hose 48. However, after that, since air does not enter the oil suction hole 19 and is filled with oil, it is possible to immediately suction even when resuming after the suspension of the suction operation.

  FIG. 5 is a cross-sectional view showing a state immediately after the suction of the VOC-adsorbed oil into the oil chamber 13, and as described above, as the drive piston 22 slides upward, Both the oil suction piston 24 slides upward, and the oil suction hole 19 and the inside of the hose 48 and the lower portion of the oil chamber 13 are in a negative pressure state. Stored in the lower part. At this time, the oil suction amount is such that the oil suction hole opening / closing valve 38 of the valve device 36 closes the inlet of the oil chamber 13 and stops the oil suction as the piston 31 of the oil suction piston 24 rises. Controlled by.

  FIG. 6 is a cross-sectional view showing a state in which the decompression chamber 12 is decompressed, and the oil suction piston 24 is inserted into the in-shaft engagement portion 30 of the piston shaft 25 as the drive piston 22 slides further upward. The head 32 of the piston shaft 31 is hooked.

  FIG. 7 is a cross-sectional view showing a state where VOC is vaporized from the oil. Following the operation in FIG. 6 described above, the oil suction piston 24 further compresses the compression spring 41 while compressing the compression spring 41. When the upper peripheral portion 24a of the piston 24 for oil suction comes into contact with the lower partition wall 10, the upward movement is restricted, but the decompression piston 23 continues to slide upward, and the decompression chamber The pressure inside 12 is reduced to a negative pressure state.

  At this time, as well shown in FIG. 11, the movement of the oil suction hole opening / closing valve 38 of the valve device 36 is restricted at the inlet of the oil chamber 13, so the VOC vent hole opening / closing valve 37 of the valve device 36 and the oil The space between the suction piston 24 and the VOC vent hole 33 is opened, and the decompression chamber 12 and the oil chamber 13 communicate with each other. Thus, the decompression chamber 12 and the oil chamber 13 communicate with each other, so that the decompression region extends to the surface of the oil stored in the oil chamber 13, the VOC adsorbed by the oil starts to vaporize, and the vaporized VOC is VOC. It collects in the decompression chamber 12 through the vent hole 33.

  The urging force of the compression spring 41 at this time is a force obtained by subtracting the sum of the surrounding frictional resistance and its own weight from the force against which the oil suction piston 24 is attracted by the negative pressure of the decompression chamber 12. Although it is necessary, even if it has a stronger force, it should be sufficiently weaker than the ascending force of the drive piston 22 by the compressed air of the compressor 42. If the urging force of the compression spring 41 is weak, the oil suction piston 24 is sucked by the negative pressure in the decompression chamber 12 in the state shown in FIG. It moves until it comes into contact with the lower partition 10, but in this process, the VOC in the decompression chamber 12 is gradually vaporized and finally the state shown in FIG. Therefore, even if the urging force of the compression spring 41 is weak, there is no adverse effect on the vaporizing action of the VOC. The compression spring 41 is immediately sucked into the negative pressure of the decompression chamber 12 at the stage of FIG. What is necessary is just to provide the urging | biasing force of the grade which the piston 24 does not slide upwards.

  Thus, in the state of FIG. 7, VOC is vaporized from the oil, but the oil itself is not vaporized at this time. This is because, for example, there is a large difference between the boiling points of VOC and oil so that the boiling point of toluene is 110.6 ° C. at ordinary temperature, whereas the boiling point of general oil is 220 ° C. or more at ordinary temperature. . Further, in this case, silicone oil is particularly suitable as an oil to be used because it does not vaporize at room temperature, is not toxic and can be used repeatedly.

  Note that the lower the pressure in the decompression chamber 12, the easier it is to vaporize VOC. However, the pressure in the decompression chamber 12 is preferably 0.01 MPa or less, which can be easily reduced. In this case, since it takes a certain amount of time for the VOC adsorbed to the oil to be released from the oil, a period of about one minute is left after the above-described decompression step, and the VOC is sufficiently vaporized from the oil. Then, it is desirable to move on to the next compression step.

  FIG. 8 is a cross-sectional view showing an initial state of a compression process in which VOC vaporized from oil is compressed from a reduced pressure state to a normal state (before pressure reduction) and liquefied. In this compression step, compressed air is converted into FIG. When the compressor 42 described above passes through the first three-way solenoid valve SV1 and is supplied from the first compressed air inlet 14 into the driving cylinder chamber 11 above the driving piston 22, the driving piston 22 is As it slides downward, the decompression piston 23 slides downward, compresses the vaporized VOC in the decompression chamber 12, and liquefies the VOC in the decompression chamber 12.

  At this time, as the pressure-reducing piston 23 slides downward, the latched state between the head portion 32 of the piston shaft 31 of the oil suction piston 24 and the in-axis engaging portion 30 of the piston shaft 25 is released. The oil suction piston 24 slides downward by the urging force of the compression spring 41, and the VOC vent hole opening / closing valve 37 is fitted into the recess 34 of the oil suction piston 24, thereby closing the VOC vent hole 33.

  Further, as the oil suction piston 24 slides downward, a gap 13a is formed in the upper portion of the oil chamber 13 between the upper surface of the oil suction piston 24 and the lower partition wall 10, so that the liquefied VOC is removed from the gap. 13a and the VOC discharge hole 21 are stored in the liquefied VOC container 8.

  In the compression process described above, the compression time of the decompression piston 23 is short, and the VOC vent hole 33 is immediately closed by the VOC vent opening / closing valve 37, so that the VOC is hardly adsorbed in the original oil. .

  Further, during the compression process described above, the air in the drive cylinder chamber 11 below the drive piston 22 passes through the second compressed air intake port 16 and is released to the outside from the NO of the second three-way solenoid valve SV2. In addition, since air is sucked into the decompression chamber 12 above the decompression piston 23 from the outside through the pressure adjusting hole 17, the interior of the drive cylinder chamber 11 below the drive piston 22 and the decompression piston 23. The inside of the decompression chamber 12 on the upper side is maintained at atmospheric pressure.

  After that, as shown in FIG. 9, the decompression piston 23 slides further downward, and the pressing portion 28 of the decompression piston 23 is loosely fitted in the opening 18 and is in contact with the oil suction piston 24. Since a gap 18 a is formed between the lower partition 10 and the periphery of the pressing portion 28, the VOC vaporized in the decompression chamber 12 is stored in the liquefied VOC container 8 through the gap 18 a and the VOC discharge hole 21.

  Further, as shown in FIG. 10, when the pressure reducing piston 23 slides downward and the pressing portion 28 of the pressure reducing piston 23 pushes down the oil suction piston 24, the oil suction hole opening / closing valve 38 is lowered, and the oil chamber The remaining oil in 13 is recovered from the oil discharge hole 20 to the recovery oil container 7. At this time, the suction hole opening / closing valve 38 is lowered and the oil chamber 13 and the oil suction hole 19 communicate with each other. However, since the oil suction hole 19 is filled with untreated oil, the remaining oil is removed from the oil discharge hole. The oil is reliably discharged from the 20 side to the recovered oil container 7. Then, when the driving piston 22, the decompression piston 23, and the oil suction piston 24 reach the bottom dead center, the discharge of the liquefied VOC and the remaining oil is finished.

DESCRIPTION OF SYMBOLS 1 VOC removal apparatus 2 Cylinder 3 Piston 4 Main body apparatus 11 Drive cylinder chamber 12 Pressure reduction chamber 13 Oil chamber 19 Oil suction hole 21 VOC discharge hole 22 Drive piston 23 Pressure reduction piston 24 Oil suction piston 25 Piston shaft 26 Hollow part 33 VOC vent hole 35 Extension part 36 Valve device 37 VOC vent hole on / off valve 38 Oil suction hole on / off valve 40 Hook 41 Compression spring 44 Control unit

Claims (8)

Taking-in means for taking in oil that has adsorbed VOCs into the main unit;
Pressure reducing means for reducing the atmospheric pressure in the main unit,
Separation means for separating VOC vaporized from the oil by depressurizing the inside of the main body device;
Compression means for liquefying the vaporized VOC by compressing the inside of the main body device;
VOC discharge means for discharging the liquefied VOC separately from the remaining oil;
The VOC removal apparatus characterized by the above-mentioned. The decompression means and the compression means comprise a piston that reciprocates in the direction of decompressing and compressing the inside of the cylinder, and a controller that controls the supply of compressed air into the cylinder and controls the reciprocation of the piston. ,
The intake means includes an oil suction hole formed in the cylinder, an oil chamber for storing oil sucked from the oil suction hole by sliding of the piston in the pressure reducing direction, and an oil suction hole. A valve device that closes the oil suction hole when a fixed amount of oil is sucked;
The separation means includes a decompression chamber that stores VOCs evaporated from oil in the oil chamber by sliding of the piston in the decompression direction,
2. The VOC discharge means includes a VOC discharge hole for liquefying the vaporized VOC by sliding the piston in the compression direction and discharging the liquefied VOC to the outside of the cylinder. VOC removal device. The piston includes a decompression piston that reciprocates in the decompression chamber, and an oil suction that reciprocates in the oil chamber as the piston shaft reciprocates along a hollow portion formed in the piston shaft of the decompression piston. A piston for
The pressure-reducing piston slides to the anti-oil suction piston side, and the space between the pressure-reduction piston and the oil suction piston becomes negative pressure, so that the oil suction piston is moved to the pressure-reduction piston side. 3. The VOC removing device according to claim 2, wherein the valve device closes the oil suction hole, and the amount of oil sucked into the oil chamber from the oil suction hole is set to a predetermined amount.   The oil suction piston is provided with a VOC ventilation hole so that the oil chamber and the decompression chamber can communicate with each other, and the valve device is slidable on the outer periphery of the extension portion of the piston shaft of the oil suction piston. A VOC vent opening / closing valve that is fitted and capable of opening / closing the VOC ventilation hole, an oil suction hole opening / closing valve capable of opening / closing the oil suction hole, a flange portion attached to a tip of the extension portion, and the flange portion; A compression spring interposed between the oil suction hole opening and closing valve, and the oil suction hole opening and closing valve closes the oil suction hole by sliding the pressure reducing piston in the pressure reducing direction. The VOC removal device according to claim 3, wherein a VOC vent opening / closing valve opens the VOC vent.   A drive cylinder chamber formed adjacent to the anti-oil chamber side of the decompression chamber and a drive piston that reciprocates in the drive cylinder chamber are provided in the cylinder, and the drive piston is The piston shaft of the decompression piston is shared, the compressed air is alternately supplied to both sides of the drive piston, and the drive piston is reciprocated to reciprocate the decompression piston and the oil suction piston. The VOC removal apparatus according to any one of claims 2 to 4.   6. The VOC removal device according to claim 5, wherein the control unit controls the driving piston so as to shift to a compression process after a predetermined time has elapsed after completion of the pressure reduction process. Compressed air is supplied to one side of the drive piston in the drive cylinder chamber, and the drive piston slides to the other side, so that the decompression piston sharing the drive piston and the piston shaft is in the decompression chamber. Sliding in the same direction as the drive piston;
As the pressure reducing piston slides, a space between the pressure reducing piston and an oil suction piston having a piston shaft that reciprocates within the piston shaft of the pressure reducing piston becomes negative pressure. A step of sliding the suction piston in the same direction as the pressure reducing piston;
As the oil suction piston slides, the oil suction hole has a negative pressure so that the oil adsorbing VOC is sucked into the oil chamber from the oil suction hole;
When a predetermined amount of oil adsorbing VOC is sucked into the oil chamber from the oil suction hole, the oil suction hole is closed by the oil suction hole on-off valve, and the suction of oil into the oil chamber is stopped; ,
As the drive piston further slides, the pressure-reducing piston and the oil suction piston slide further in the same direction as the drive piston, and the VOC vent hole provided in the oil suction piston has a VOC passage. A step opened by a pore opening / closing valve;
The oil chamber and the decompression chamber communicate with each other via the opened VOC vent opening / closing valve, and the VOC adsorbed by the oil stored in the oil chamber is vaporized, and the vaporized VOC passes through the VOC communication hole. A process through which it is collected in a vacuum chamber;
Compressed air is supplied to the other side of the driving piston, and the driving piston is slid to one side, so that the pressure reducing piston and the oil suction piston slide in the same direction as the driving piston. The vaporized VOC in the decompression chamber is compressed and liquefied;
A step of discharging the liquefied VOC from the VOC discharge hole to the outside of the decompression chamber;
VOC removal method characterized by including. 8. The VOC removal method according to claim 7, further comprising a step of controlling the control unit so that the driving piston moves to a compression step after a predetermined time has elapsed after the pressure reduction step.

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