JP2016022463A - Plant exhaust gas purifier and plant exhaust gas purification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant exhaust gas purifier and a plant exhaust gas purification method capable of improving energy recovery efficiency while ensuring low cost.SOLUTION: A plant exhaust gas purifier comprises: an upstream cyclone portion 310 including a first shell 312 having a first swirl space 316 formed therein, plant exhaust gas introduced from outside swirling in the first swirl space 316; and a downstream cyclone portion 330 including a plurality of second shells 332 each having a second swirl space 336 smaller in volume than the first swirl space 316 formed therein, the plant exhaust gas introduced from the first swirl space 316 being introduced into the second shells 332, at least part of the downstream cyclone portion 330 being located within the first shell 312.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a plant exhaust gas cleaning device and a cleaning method for removing dust in plant exhaust gas generated in a plant.

  In operation of a plant such as a casting plant, a steel plant, a woodworking plant, a food plant, a chemical plant, and a chemical plant, air containing dust of various sizes (hereinafter referred to as “plant exhaust gas”) is generated. For this reason, dust is removed from the plant exhaust gas to obtain clean air, which is then diffused into the atmosphere.

  In order to collect dust from plant exhaust gas, bag filters (for example, Patent Documents 1 to 3), wet scrubbers, and electrostatic precipitators are conventionally used.

JP 7-96127 A Japanese Patent Laid-Open No. 10-151312 Japanese Patent Laid-Open No. 2003-20482

  However, the bag filter is likely to be clogged, and it is necessary to frequently replace and clean the filter in order to maintain the dust collecting power, which increases the running cost. If a wet scrubber is employed, a large amount of wet processing-related equipment is required, which increases the cost required for capital investment and the running cost. When a failure occurs, an electric dust collector has problems in practical use, such as being forced to stop operation for a long time in order to replace parts and devices, and requiring a large installation space.

  An object of the present invention is to provide a plant exhaust gas cleaning device and a cleaning method capable of improving the dust recovery rate at a low cost.

  In order to solve the above-mentioned problems, a plant exhaust gas cleaning apparatus of the present invention has an upstream having a first pipe body into which a first swirling space in which plant exhaust gas generated in the plant is introduced and into which the plant exhaust gas swirls is formed. A plurality of second tubular bodies in which a cyclonic section and a second swirling space having a diameter or volume smaller than that of the first swirling space, in which the plant exhaust gas introduced from the first swirling space swirls, are formed; And a downstream cyclone section in which plant exhaust gas swirling in one swirling space is guided to a plurality of second pipe bodies, and at least a part of the downstream cyclone section is located in the first pipe body.

  At least a part of the plurality of second tubular bodies may protrude into the first turning space from above the first tubular body, or the whole may be located in the first turning space.

  The first swirl space may have a circular horizontal cross-sectional shape, and the plurality of second tubular bodies may be disposed so as to surround the center position of the first swirl space.

  In addition, a communication pipe that guides the plant exhaust gas from the first swirl space to the second swirl space is provided at the center position of the first swirl space surrounded by the plurality of second pipes. An inlet for introducing the plant exhaust gas, which is formed at the lower end of the main body and swirling the first swirl space, into the main body, and the plant exhaust gas that is introduced from the inlet to the main body and ascends the main body, It is good also as providing a diversion port led to two pipes.

  Moreover, the lower end of the main body part in which the introduction port is formed may have a shape in which the diameter gradually increases toward the tip.

  Moreover, it is good also as providing the collective discharge part which collects the plant exhaust gas which swirled the some 2nd turning space, and discharges outside.

  In addition, the collective discharge section includes an exhaust pipe in which at least the lower end is disposed in the second pipe body, and the plant exhaust gas rises from below to above, and the lower end of the exhaust pipe gradually increases in diameter toward the tip. It is good also as a shape to do.

  In addition, an opening is provided at the lower end of the second tubular body for vertically discharging dust centrifugally separated from the plant exhaust gas in the second swirling space, and a plurality of second tubular bodies are provided in the first tubular body. A conical tube may be provided in which a lower end is located inside and a dust chamber for storing dust discharged from an opening at the lower end of the second tubular body is formed.

  Further, a preduster that roughly collects dust from the plant exhaust gas may be provided, and the plant exhaust gas coarsely collected by the preduster may be introduced into the upstream cyclone unit.

  In addition, the pre-duster has a pre-pipe body in which a pre-swirl space in which plant exhaust gas swirls is formed, and a discharge pipe in which an inlet for introducing the plant exhaust gas is formed at one end and the one end is located in the pre-pipe. And may be provided.

  The pre-duster includes a vertical chamber tube, an annular swirl channel formed in the vertical chamber tube, a swirl unit that guides and swirls the plant exhaust gas from the outside of the vertical chamber tube to the swirl channel, and an intake port. And a discharge pipe that is formed at one end and positions the one end within the vertical chamber tube.

  In order to solve the above-mentioned problems, a method for cleaning plant exhaust gas according to the present invention includes a step of swirling plant exhaust gas in a first swirling space and removing dust from the plant exhaust gas by centrifugation, and removing dust in the first swirling space. And swirling the plant exhaust gas in a second swirl space having a smaller diameter or volume than the first swirl space, and removing dust smaller than the dust removed in the first swirl space from the plant exhaust gas by centrifugation. , Including.

  According to the present invention, the dust recovery rate can be improved and the environmental load can be reduced while the cost is low.

It is a figure explaining the whole system | strain of a plant. It is a figure explaining the whole system | strain of the cleaning apparatus of 1st Embodiment. It is a conceptual diagram explaining the preduster which comprises the cleaning apparatus of 1st Embodiment. It is a conceptual diagram explaining the dust collector which comprises the cleaning apparatus of 1st Embodiment. It is the VV sectional view taken on the line in FIG. It is a conceptual diagram explaining the dust collector of 2nd Embodiment. It is the VII-VII sectional view taken on the line in FIG. It is a conceptual diagram explaining the dust collector of 3rd Embodiment. It is the IX-IX sectional view taken on the line in FIG. It is a conceptual diagram explaining the preduster of 4th Embodiment. It is a horizontal sectional view of a turning part. (A) is an enlarged view of the XII (a) portion in FIG. 11, (b) is an enlarged view of the XII (b) portion in FIG. 10, and (c) is XII (c) -XII (c) in FIG. FIG. It is a figure explaining the attachment or detachment method of the turning part at the time of the wind rest of a plant.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating the entire system of the plant P, and FIG. 2 is a diagram illustrating the entire system of the cleaning device 100 according to the first embodiment. A plant P shown in FIG. 1 is a plant such as a casting plant, a steel plant, a woodworking plant, a food plant, a chemical plant, or a chemical plant, and generates plant exhaust gas during operation. Therefore, in the plant P, one or a plurality of dust collection points are provided, and the plant exhaust gas is exhausted from the dust collection points. A plurality of dust collection hoods 1 are provided at the dust collection location, and a cleaning device 100 is connected to the dust collection hood 1 via a dust collection duct 2. Therefore, the plant exhaust gas is introduced into the cleaning device 100 that cleans the gas via the dust collection hood 1 and the dust collection duct 2.

  As will be described in detail later, as shown in FIG. 2, the cleaning device 100 removes dust from the plant exhaust gas, and includes a preduster 200 and a dust collector 300 connected to the discharge pipe 230 of the preduster 200. It is comprised including. The preduster 200 removes coarse particle dust and medium particle dust from the plant exhaust gas. By providing the pre-duster 200, when the amount of dust in the plant exhaust gas is large or when the dust particles are coarse, it is possible to reduce the burden on the dust collector 300 installed in the subsequent stage. Plant exhaust gas from which coarse particle dust and medium particle dust have been removed by the pre-duster 200 is introduced into the dust collector 300 through the exhaust pipe 230, and fine dust is removed from the plant exhaust gas.

  Returning to FIG. 1, the plant exhaust gas from which dust has been removed by the cleaning device 100 (hereinafter, the plant exhaust gas from which dust has been removed by the cleaning device 100 is referred to as “clean gas”) includes the junction pipe 8, the damper. 9 is sucked by a suction unit (exhaust fan, blower) 10. The suction unit 10 is driven by an electric motor and sends out the sucked clean gas to the chimney 11. Then, the clean gas guided to the chimney 11 is diffused to the atmosphere.

  Next, the cleaning device 100 according to the first embodiment will be described in detail with reference to FIGS.

  FIG. 3 is a conceptual diagram illustrating the pre-duster 200 constituting the cleaning device 100 of the first embodiment. As shown in FIG. 3, the pre-duster 200 has a cylindrical upper tube portion 210a and a tapered conical portion 210b that is continuous with the lower end of the upper tube portion 210a and gradually decreases in diameter from the upper side toward the lower side. A pre-pipe body 210 made of a pipe member is provided, and the pre-pipe body 210 is installed along the central axis in the vertical direction. A pre-swirl space 212 having a circular horizontal cross-sectional shape is formed inside the pre-pipe body 210, and a pre-gas inlet 214 to which the dust collection duct 2 is connected is formed in the upper tube portion 210a. The pregas introduction port 214 is arranged so that the plant exhaust gas introduced into the pre-swirl space 212 from the dust collection duct 2 flows from the center of the upper tube portion 210a to the inner periphery so that it flows along the tangential direction or the inner peripheral surface of the upper tube portion 210a. The opening is shifted to the surface side. In other words, the opening angle of the pre-gas inlet 214 is set so that the plant exhaust gas turns in the pre-turn space 212.

  As a result, the plant exhaust gas guided to the pre-pipe body 210 by suction by the suction unit 10 swirls in the pre-swirling space 212 as shown by an arrow a in FIG. Coarse particles and medium particles are separated from plant exhaust gas by inertia and gravity. Thus, the dust centrifuged from the plant exhaust gas in the pre-swirl space 212 finally falls into the pre-duster chamber 220 due to its own weight, and is stored in the pre-duster chamber 220.

  As described above, the plant exhaust gas from which the dust is centrifuged in the pre-swirl space 212 is reversed in the flow direction upward in the axial direction inside the pre-duster chamber 220, and as shown by the arrow b in FIG. It will be guided to the discharge pipe 230 from the suction port 230a. Therefore, the plant exhaust gas from which the dust is centrifuged in the pre-swirl space 212 enters the exhaust pipe 230 from the suction port 230a, and rises in the exhaust pipe 230 from below to above.

  In addition, the lower end of the discharge pipe 230 in which the suction port 230a is formed has a curved shape of a bell mouth whose diameter gradually increases toward the tip. Thus, by making the lower end of the discharge pipe 230 into the curved shape of a bell mouth, the pressure loss at the time of gas suction is reduced to 1/20 or less compared to the case where the lower end is a straight pipe of the same diameter. Thus, the gas flow velocity at the lower end of the discharge pipe 230 can be increased, and the pressure loss of the entire preduster 200 system can be greatly reduced.

  The lower end of the pre-pipe body 210 is located in the pre-duster chamber 220 (below the upper surface 220a of the pre-duster chamber 220), and the diameter of the upper surface 220a of the pre-duster chamber 220 increases from the upper side to the lower side. It is constructed in a gradually increasing Jinkasa taper shape. As a result, when the plant exhaust gas directed from the upper side to the lower side is reversed upward in the pre-duster chamber 220, the dust separated from the plant exhaust gas is re-scattered and soared under the umbrella of the upper surface 220a of the pre-duster chamber 220. Suppressed.

  Next, a dust collector 300 that is connected to the discharge pipe 230 of the preduster 200 and further removes dust from the plant exhaust gas from which coarse dust and medium dust are removed by the preduster 200 will be described. FIG. 4 is a conceptual diagram for explaining the dust collector 300 constituting the cleaning device 100 of the first embodiment, and FIG. 5 is a cross-sectional view taken along line VV in FIG. The dust collector 300 which comprises the cleaning apparatus 100 of 1st Embodiment is provided with the upstream cyclone part 310 which removes the fine particle dust in the plant exhaust gas guide | induced from said discharge pipe 230. FIG. The upstream cyclone unit 310 includes a first tubular body 312 and a dust chute 314 connected to the lower portion of the first tubular body 312.

  The first tubular body 312 is continuous with the cylindrical side wall portion 312a, the tapered lower end of the side wall portion 312a, and the tapered conical portion 312b whose diameter gradually decreases from the upper side to the lower side, and the upper end of the side wall portion 312a is closed. And an end plate-shaped upper surface portion 312c, and is installed along the central axis in the vertical direction. A first swirl space 316 having a circular horizontal cross-sectional shape is formed inside the first tube body 312, and a first gas introduction port 318 to which the discharge pipe 230 is connected is formed in the side wall portion 312 a. Yes. The first gas inlet 318 is arranged so that the plant exhaust gas introduced into the first swirl space 316 from the discharge pipe 230 flows from the center of the side wall 312a to the inner periphery so that it flows along the tangential direction or the inner peripheral surface of the side wall 312a. The opening is shifted to the surface side. In other words, the opening angle of the first gas inlet 318 is set so that the plant exhaust gas turns at a high speed in the first turning space 316.

  Thereby, the plant exhaust gas guided to the first tube body 312 from the outside swirls in the first swirl space 316, and in this swirl process, the dust is centrifuged from the plant exhaust gas by inertia and gravity due to centrifugal force. Is done. As described above, the dust centrifuged from the plant exhaust gas in the first swirl space 316 finally falls to the dust chute 314 due to its own weight and is stored in the dust chute 314 as shown by an arrow a in FIG. The

  As described above, the plant exhaust gas from which the dust is centrifuged in the first swirl space 316 is guided from the upper part of the first pipe 312 to the communication pipe 320 as indicated by an arrow b in FIG. The communication pipe 320 includes a main body part 320a penetrating the upper surface part 312c of the first pipe body 312 in the vertical direction at the center position of the first swivel space 316, and the first swirl is provided at the lower end of the main body part 320a. An introduction port 320b for introducing the plant exhaust gas swirling through the space 316 into the main body 320a is formed. Therefore, the plant exhaust gas from which the dust is centrifuged in the first swirl space 316 enters the main body 320a from the introduction port 320b and rises upward from below in the main body 320a.

  In addition, the lower end of the main body part 320a in which the introduction port 320b is formed has a curved shape of a bell mouth whose diameter gradually increases toward the tip. Thus, by making the lower end of the main body portion 320a a curved surface shape of a bell mouth, the pressure loss at the time of gas suction can be reduced to 1/20 or less compared to the case where the lower end is a straight pipe having the same diameter. It is possible to increase the gas flow velocity at the lower end of the main body part 320a, and in addition to the curved shape of the bell mouth at the lower end of the exhaust pipe 370, which will be described later, at the lower end of the main body part 320a and the lower end of the exhaust pipe 370. The gas flow rate can be increased, and the pressure loss of the entire dust collector 300 system can be greatly reduced.

  Further, a diversion chamber 320c is formed inside the upper end side of the main body part 320a, and a plurality of parts that penetrate the main body part 320a in the radial direction are formed on the upper end side of the main body part 320a, that is, the part surrounding the diversion chamber 320c. The diversion port 320d is formed. A connection pipe 322 is connected to each of the plurality of diversion openings 320d, and the plant exhaust gas that has been moved up the main body 320a and led to the diversion chamber 320c is diverted in the radial direction by the diversion openings 320d. Is guided to the plurality of second tubular bodies 332 of the downstream cyclone unit 330 along the tangential direction.

  The downstream cyclone unit 330 is located on the downstream side of the upstream cyclone unit 310, and removes fine-grained dust that could not be removed by the upstream cyclone unit 310 from the plant exhaust gas. The downstream cyclone unit 330 includes a plurality (eight in the first embodiment) of second tube bodies 332 and a conical tube 334.

  The second tubular body 332 includes a cylindrical upper wall portion 332a, a tapered lower wall portion 332b that is continuous with the lower end of the upper wall portion 332a, and gradually decreases in diameter from the upper side to the lower side, and an upper wall portion 332a. And a closing member 332c that closes the upper end of the tube, and is installed along the central axis in the vertical direction. Inside the second tubular body 332, the plant exhaust gas introduced from the first swirl space 316 swirls at a high speed, and a second swirl space 336 having a diameter smaller than that of the first swirl space 316 is formed.

  A second gas introduction port 338 to which the connection pipe 322 is connected is formed in the upper wall portion 332a. The second gas introduction port 338 is formed at the center of the upper wall portion 332a so that the plant exhaust gas introduced into the second swirl space 336 from the connection pipe 322 flows along the tangential direction or the inner peripheral surface of the second pipe body 332. The opening is shifted from the angle to the inner peripheral surface side. In other words, the opening angle of the second gas inlet 338 is set so that the plant exhaust gas turns in the second turning space 336.

  In addition, the plurality of second tubular bodies 332 has an upper end side located above the first tubular body 312, and a part of the lower end side protrudes into the first turning space 316 of the first tubular body 312. More specifically, the upper surface 312c of the first tubular body 312 has a plurality of insertion holes through which the second tubular body 332 is inserted, and the lower end of the second tubular body 332 has an upper surface 312c. It is being fixed to the upper surface part 312c of the 1st pipe 312 in the state inserted in each insertion hole from the upper direction.

  At this time, as shown in FIG. 5, the plurality of second tubular bodies 332 are arranged so as to surround the center position of the first swirl space 316 (equally in the circumferential direction), and the communication pipe 320 is The first swirling space 316 is surrounded by a plurality of second tubular bodies 332. The diversion port 320d of the communication pipe 320 and the second gas introduction port 338 of the second pipe body 332 are opposed to each other, and the diversion port 320d and the second gas introduction port 338 arranged so as to face each other are connected to the connection pipe 322. Connected by. In this way, in the downstream cyclone section 330, the plant exhaust gas swirled in the first swirl space 316 is passed through the communication pipe 320 and each of the plurality of second pipe bodies 332 is shown by the arrow c in FIG. It is dispersed in the second swirl space 336 and guided in the tangential direction.

  The plant exhaust gas guided from the communication pipe 320 to the second pipe body 332 is swirled in the second swirl space 336, and dust is further centrifuged at a high flow rate from the plant exhaust gas in this swirling process. Thus, the dust centrifuged at a high flow rate from the plant exhaust gas in the second swirl space 336 finally falls in the second tubular body 332 by its own weight, as indicated by an arrow d in FIG. At the lower end of the second tubular body 332, an opening 332d for discharging dust that has been centrifuged from the plant exhaust gas in the second swirl space 336 vertically downward is provided.

  In addition, a conical tube 334 of the downstream cyclone unit 330 is provided in the first tube body 312 (first swirl space 316). The conical tube 334 is formed of a conical tube whose diameter gradually decreases from the upper end toward the lower end, and a dust chamber 334a is formed therein. The dust chamber 334a is sealed, and the lower ends of the plurality of second pipe bodies 332 pass through a through-hole formed in the upper surface of the conical tube 334, and are located inside the conical tube 334 (in the dust chamber 334a). It is provided to do. Therefore, the dust discharged from the opening 332d at the lower end of the second tubular body 332 falls into the dust chamber 334a and is stored.

  As described above, the dust centrifuged from the plant exhaust gas in the downstream cyclone unit 330 is stored in the dust chamber 334 a in the conical tube 334. On the other hand, the dust centrifuged from the plant exhaust gas in the upstream cyclone section 310 is stored in the dust chute 314 provided separately from the dust chamber 334a as described above. Accordingly, dust having a relatively large particle size is stored in the dust chute 314, and fine particle dust having a relatively small particle size is stored in the dust chamber 334a.

  The outer diameter of the conical tube 334 is smaller than the inner diameters of the side wall portion 312 a and the conical portion 312 b of the first tube body 312, and a gap is formed between the outer wall of the conical tube 334 and the inner wall of the first tube body 312. Has been. Thereby, the 1st turning space 316 formed in the inside of the 1st pipe body 312 becomes a cyclic | annular space centering on the conical tube 334 except for a partial upper space. That is, it can be said that the conical tube 334 has a function of rectifying the swirl flow of the plant exhaust gas in the first swirl space 316 in addition to the function of storing the dust centrifuged in the second swirl space 336.

  A lower bell 340 having a tapered surface 340a whose diameter gradually increases from the upper side to the lower side is fixed to the outer peripheral lower portion of the conical tube 334. Therefore, the dust centrifuged from the plant exhaust gas in the first swirl space 316 falls to the dust chute 314 while sliding on the tapered surface 340a of the lower bell 340 having the Jinkasa tapered shape. In addition, the tapered surface 340a of the lower bell 340 inverts the swirling flow from the upper side to the lower side again in the first swirling space 316. At this time, the dust separated from the plant exhaust gas is re-scattered and soared. Is suppressed under the umbrella of the lower bell 340.

  Below the dust chute 314 and the conical tube 334, an airflow conveying device 350 for airflowing dust stored in the dust chamber 334a and the dust chute 314 is provided. The air flow conveying device 350 includes a dust bin 352 disposed below the dust chute 314 and the conical tube 334. The dust bin 352 is connected to a dust chute 314 and a conical tube 334 via a dust discharge pipe 354 having a dust cut valve and a seal valve (not shown) for cutting out dust, and the dust cut out from the dust chute 314 is connected to the dust bin 352. And the dust cut out from the dust chamber 334a are separated and stored.

  In addition, similarly to the dust discharge pipe 354, a dust cutting pipe 356 provided with a dust cut valve, a seal valve, and the like is connected to the lower end of the dust bin 352. Further, the dust cutting tube 356 communicates with the dust transfer line 358, and a carrier gas such as nitrogen gas or air is supplied to the dust transfer line 358 via the carrier gas tube 360. As a result, the dust cut out in the dust bin 352 is transported out of the system from the dust transport line 358 by the carrier gas.

  On the other hand, the plant exhaust gas from which the dust is centrifuged in the second swirl space 336 is guided to the exhaust pipe 370 from the upper part of the second pipe body 332. The exhaust pipe 370 penetrates the closed portion 332c of each second tubular body 332 in the vertical direction at the center position of the second swirl space 336. The lower end of the exhaust pipe 370 is located in the second pipe body 332, that is, in the second swirl space 336, and the upper end is connected to the merge pipe 8. In this way, the exhaust pipe 370 and the merging pipe 8 constitute the collective discharge part 372, and the collective exhaust part 372 collects the clean gas after the dust is centrifuged in the plurality of second swirl spaces 336. Then, it is discharged outside the cleaning device 100. The lower end of the exhaust pipe 370 also has a curved shape of a bell mouth whose diameter gradually increases toward the tip, similarly to the communication pipe 320 described above, and the pressure loss of the entire dust collector 300 system in which the gas flow rate is large. Significant reduction is achieved.

  According to the cleaning device 100 of the first embodiment, the preduster 200 removes coarse particle dust and medium particle dust from the plant exhaust gas, and the plant exhaust gas is swirled in the first swirl space 316 and finely separated from the plant exhaust gas by centrifugation. The step of removing the particulate dust, and the plant exhaust gas from which the dust has been removed in the first swirl space 316 are swirled at a higher flow rate in the second swirl space 336 having a diameter smaller than that of the first swirl space 316, and by centrifugation, And a step of removing finer dust than the dust removed in the first swirl space 316 from the plant exhaust gas.

  And according to said cleaning apparatus 100, since dust content in clean gas can fully be reduced, since there is no filter like the conventional bag filter, in order to maintain dust collection power It is not necessary to replace the filter, the frequency of cleaning can be reduced, and the running cost can be reduced. Moreover, since there is no filter like the conventional bag filter, the efficiency of preventing atmospheric pollution can be improved.

  Moreover, compared with the conventional bag filter, the pressure loss of the whole cleaning apparatus 100 can be reduced, and the driving power of the suction unit 10 can be reduced.

  Furthermore, compared with the conventional bag filter, since the cleaning device 100 is small, the installation space can be reduced.

  Further, unlike the conventional wet dust collection method, the cleaning device 100 of the present embodiment can collect dust in a dry state (can be recovered as dry dust), thereby reducing the cost required for capital investment and reducing the environmental load. Can be reduced.

  FIG. 6 is a conceptual diagram illustrating a dust collector 400 according to the second embodiment, and FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. The dust collector 400 of the second embodiment is different from the dust collector 300 of the first embodiment in the arrangement of the second tubular body 332, and other configurations and operations are substantially the same as those of the first embodiment. There is no difference. Therefore, description of the same configuration as that of the first embodiment is omitted here, and only differences from the first embodiment will be described.

  In the dust collector 400 of the second embodiment, a plurality of second pipes 332 are placed on the upper surface portion 312c of the first pipe 312 with the central axis of the second pipe 332 inclined with respect to the vertical direction. Inserted and fixed. More specifically, the plurality of second tubular bodies 332 has a lower end side protruding into the first tubular body 312 (first swirl space 316) with respect to an upper end side located above the first tubular body 312. The first swirl space 316 is located on the inner side (center side) in the radial direction. By arranging the second tubular body 332 in this way, the body diameter of the first tubular body 312 can be reduced, and further cost reduction and installation space reduction can be realized.

  FIG. 8 is a conceptual diagram illustrating a dust collector 500 according to the third embodiment, and FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. The dust collector 500 of the third embodiment is different from the dust collector 300 of the first embodiment in the arrangement of the second tubular body 332, and other configurations and operations are substantially the same as those of the first embodiment. There is no difference. Therefore, description of the same configuration as that of the first embodiment is omitted here, and only differences from the first embodiment will be described.

  In the dust collector 500 of the third embodiment, the entire second tube body 332 is located in the first tube body 312 (first swirl space 316). Accordingly, the communication pipe 320 is also provided in the first pipe body 312 (first swirl space 316), and in the dust collector 500 of the third embodiment, the upper surface portion 312c of the first pipe body 312 is provided. Has a flat plate shape. Thus, by providing the entire second tube body 332 in the first tube body 312 (first swirl space 316), the total length of the dust collector 500 can be reduced.

  FIG. 10 is a conceptual diagram illustrating a pre-duster 600 according to the fourth embodiment. The preduster 600 is a straight flow type cyclone dust remover, and includes an upper cone 602 having one end connected to the dust collection duct 2. The upper cone 602 is configured by a substantially conical pipe whose diameter gradually increases from the upper end connected to the dust collecting duct 2 toward the lower end, and a vertical chamber tube 604 is formed at the lower end of the upper cone 602. Is connected. The vertical chamber tube 604 is formed of a cylindrical tube member having an internal space, and is installed with its axis aligned along the vertical direction. The gap formed in the vertical chamber tube 604 becomes an annular swirl flow path 608 in which the plant exhaust gas swirls.

  The inlet bell 612 is configured by a conical member whose diameter gradually increases from the upstream side to the downstream side in the flow direction of the plant exhaust gas, that is, from vertically upward to downward, and is fixed to the upper cone 602. The axis of the inlet bell 612 coincides with the axis of the upper cone 602, and the horizontal upper and lower divided surface 612 a having the largest diameter is positioned in the vertical chamber tube 604. The diameter of the horizontal upper and lower divided surface 612a of the inlet bell 612 is smaller than the diameter of the vertical chamber tube 604, and an annular space through which plant exhaust gas flows between the inlet bell 612, the upper cone 602, and the vertical chamber tube 604. The flow path 614 is formed. In addition, this flow path 614 becomes narrow gradually as it goes to the downward direction from the vertically upper direction as shown in the drawing, that is, from the upstream side to the downstream side in the flow direction of the plant exhaust gas. Therefore, the inlet bell 612 sends the plant exhaust gas guided from the dust collection duct 2 to the swirl flow path 608 while increasing the flow velocity while rectifying.

  Between the horizontal upper and lower divided surfaces 612a of the inlet bell 612 and the vertical chamber tube body 604, the plant exhaust gas is guided from the inside of the vertical chamber tube body 604 (upper cone 602) to the swirl channel 608, and the swirl channel A turning unit 620 for turning the plant exhaust gas in the circumferential direction 608 is provided. The swirl unit 620 changes the flow direction of the plant exhaust gas flowing in the vertical direction along the inner peripheral surfaces of the upper cone 602 and the vertical chamber tube body 604 and swirls the plant exhaust gas in the swirl flow path 608.

  11 is a horizontal sectional view of the swivel unit 620, FIG. 12A is an enlarged view of a portion XII (a) in FIG. 11, FIG. 12B is an enlarged view of a portion XII (b) in FIG. FIG. 12C is a sectional view taken along line XII (c) -XII (c) in FIG. As shown in FIG. 11, the turning portion 620 includes a cylindrical ring portion 622. The ring portion 622 is configured by connecting divided rings 622a to 622d that are divided into a plurality (four in this embodiment) in the circumferential direction. Specifically, as shown in FIG. 11 and FIG. 12A, the split rings 622a to 622d include first flange portions 624 that protrude radially inward from both ends in the circumferential direction. A cylindrical ring portion 622 is formed by bolting the first flange portions 624 of the split rings 622a to 622d adjacent to each other.

  Further, as shown in FIG. 11 and FIG. 12B, the turning portion 620 includes a second flange portion 626 that protrudes radially inward from the upper end portion of the ring portion 622. A plurality of bolt holes 626a are formed in the second flange portion 626 at regular intervals in the circumferential direction.

  On the other hand, as shown in FIG. 12B, the upper cone 602 is provided with a cone opening 602a, and a suspension bolt 602b is inserted into the cone opening 602a. One end of the suspension bolt 602 b is connected to an eyepiece 612 d erected from the inlet bell 612, and the other end is screwed with a nut 602 c outside the upper cone 602. In this way, the entrance bell 612 is fixed to the upper cone 602. The cone opening 602a is gas-sealed by a gas seal pipe 602d and a cap 602e.

  Further, at the lower end of the inlet bell 612, a horizontal upper and lower divided surface 612a is formed by machining, and a plurality of through holes 612b corresponding to the bolt holes 626a of the second flange portion 626 are formed. Then, the bolt hole 626 a of the second flange portion 626 is bolted so as to face the through hole 612 b formed in the horizontal upper and lower divided surface 612 a of the inlet bell 612, so that the swivel unit 620 is connected to the vertical chamber tube body 604. At the upper part, it is detachably held by the inlet bell 612. An inlay portion 612c is provided on the horizontal upper and lower divided surface 612a. This is because, when attaching (combining) the cylindrical ring portion 622 that is integrated with the lower portion of the inlet bell 612, a step and a steal are formed so that both can be reliably centered.

  In the state where the swivel unit 620 is held by the inlet bell 612, a gap is maintained between the outer peripheral surface of the ring unit 622 and the vertical chamber tube 604. A plurality of integrally formed guide vanes 630 are located. A plurality of the guide vanes 630 are formed at regular intervals in the circumferential direction of the ring portion 622, and the circumferential direction of the swirling flow path 608 in a state where the swirling portion 620 is disposed on the upper portion of the vertical chamber tube 604. Are spaced apart from each other.

  As shown in FIG. 12C, the guide vane 630 has a curved portion at least partially between the upstream end 630a located upstream in the flow direction of the plant exhaust gas and the downstream end 630b located downstream. The distance between adjacent guide vanes 630 is a curved shape, and the downstream end 630b is smaller than the upstream end 630a. As a result, the plant exhaust gas guided from the upper cone 602 to the swirl unit 620 increases the flow velocity by the guide vanes 630 and generates a swirl flow in the swirl flow path 608.

  That is, the plant exhaust gas introduced from the dust collection duct 2 is accelerated by the guide vane 630 of the swirl unit 620 to become a strong swirl flow, and is guided into the swirl flow path 608. Since the rotational speed of the swirl flow increases as it approaches the axis of the vertical chamber tube 604 in the swirl flow path 608, the coarse particle dust and medium particle dust contained in the plant exhaust gas are caused by the inertia of the centrifugal force and the gravity. As shown by the one-dot chain line arrow in FIG. 10, the vertical chamber tube body 604 is separated to the inner peripheral surface side, swivels along the inner peripheral surface of the vertical chamber tube body 604 and descends (sinks).

  The discharge pipe 650 is a duct that connects the vertical chamber pipe body 604 and the dust collector 300 (upstream cyclone section 310). Since the vertical chamber tube body 604 and the dust collector 300 may be installed apart from each other, the thermal expansion in the axial direction (horizontal direction) of the discharge tube 650 and the temperature of the vertical chamber tube body 604 and the dust collector 300. The displacement in the vertical direction is caused by the difference from the thermal expansion in the direction (vertical direction) orthogonal to the axis of the discharge pipe 650 based on the difference. Therefore, in the present embodiment, the discharge pipe 650 is configured by, for example, a universal bellows-type telescopic pipe unit. The universal bellows-type telescopic tube unit constrains the internal pressure thrust of the pipe by connecting two bellows with a tie rod and bolt with a stiffening ring, and the axial expansion of the discharge pipe 650 in the direction perpendicular to the axis. The difference with thermal expansion can be absorbed and the displacement of the discharge pipe 650 in the vertical direction can be suppressed. In addition, a round one-corner connecting pipe is disposed at the other end of the discharge pipe 650, and the round one-corner connecting pipe is connected to the upstream cyclone unit 310.

  Further, the exhaust pipe 650 is formed with an inlet 650a for guiding the plant exhaust gas at one end thereof, and the inlet 650a is opened vertically downward to be positioned in the vertical chamber tube 604. The discharge pipe 650 includes an extending part 650b extending upward from the suction port 650a and a curved pipe continuous from the extending part 650b. The diameter of the suction port 650 a is smaller than the diameter of the vertical chamber tube 604, and a gap is formed between the outer peripheral surface of the discharge tube 650 and the inner peripheral surface of the vertical chamber tube 604. The lower end of the vertical chamber tube 604 is connected to the lower cone 642 and the pre-duster chamber 644. Accordingly, the coarse particle dust and medium particle dust separated from the plant exhaust gas by the swirling flow fall in a gap formed between the outer peripheral surface of the discharge pipe 650 and the inner peripheral surface of the vertical chamber tube body 604. Thus, it is stored in the pre-duster chamber 644. On the other hand, the plant exhaust gas from which coarse particle dust and medium particle dust are separated is guided to the discharge pipe 650 via the suction port 650a.

  The end of the discharge pipe 650 (extension portion 650b) in which the suction port 650a is formed has a curved shape of a bell mouth whose diameter gradually increases toward the tip. Thus, by making the end portion of the discharge pipe 650 into the curved shape of a bell mouth, the pressure loss at the time of gas suction is reduced to 1/20 or less compared to the case where the end portion is a straight pipe having the same diameter. It is possible to increase the gas flow velocity at the tip of the discharge pipe 650 (suction port 650a), and the pressure loss of the entire preduster 600 system can be greatly reduced. Here, the end face shape of the suction port 650a is a bell mouth curved surface shape, but the shape of the suction port 650a is not particularly limited, and may be a straight pipe end face shape.

  Further, a preduster bell 652 having a Jinkasa tapered shape is fixed to the upper part of the outer periphery of the extending portion 650b of the discharge pipe 650. The preduster bell 652 is formed in a Jinkasa tapered shape whose diameter gradually increases from the top to the bottom, and the coarse particle dust and medium particle dust separated from the plant exhaust gas slide down the taper surface of the preduster bell 652, The cone portion 642 is guided to the pre-duster chamber 644. Further, the pre-duster bell 652 can suppress re-scattering and soaring of coarse particle dust and medium particle dust caused by colliding with the bottom of the lower cone portion 642 under the umbrella.

  The coarse particle dust and medium particle dust stored in the pre-duster chamber 644 are discharged to the outside by the dust discharge mechanism 660. The dust discharge mechanism 660 includes a thermometer, a deposition sensor, and the like, and includes a dust detection unit (not shown) that detects the dust level of the pre-duster chamber 644, a dust cutout unit 662, and a pug mill 664. The dust cutting unit 662 includes a dust control valve, a dust cut valve, and a seal valve, and opens and closes these valves in accordance with the dust level detected by the dust detection unit to remove coarse particle dust and medium particle dust. It discharges to 664. The pug mill 664 sprays water so as to prevent dust generation and scattering, and discharges dust to a dust transport vehicle (vacuum car). Thus, the dust guided to the dust transport vehicle is used as a raw material for flooring of a sintering machine in a sintering factory.

  In the present embodiment, two (two stations) pre-duster chambers 644 are provided in the lower conical portion 642. By alternately using the two pre-duster chambers 644, dust can be reliably discharged through the other pre-duster chamber 644 even when a discharge trouble occurs in one of the pre-duster chambers 644. As described above, two or more pre-duster chambers 644 are preferably provided, but one pre-star chamber 644 may be provided in order to reduce the equipment cost.

  Further, as shown in FIG. 10, the pug mill 664 is supported by the column deck via the column gutter and the frame together with the vertical chamber tube 604.

  Further, a space for separating coarse particle dust and medium particle dust from plant exhaust gas is defined as a separation space, and the distance of this separation space, that is, the distance from the upper end of the vertical chamber tube body 604 to the suction port 650a is defined as H. Let D be the inner diameter of the body 604. In this case, if the ratio H / D between the distance H of the separation space and the inner diameter D of the vertical chamber tube 604 is small, inertial separation with respect to dust particles in the plant exhaust gas does not function sufficiently. When D is large, the dust particles separated by the swirling flow are likely to be scattered again on the downstream side of the separation space. Therefore, the ratio H / D between the distance H of the separation space and the inner diameter D of the vertical chamber tube 604 is preferably 4 or less, and is preferably about 3.0 to 4.0.

  Further, assuming that the inner diameter of the discharge pipe 650 is E, the ratio E / D between the inner diameter D of the vertical chamber tube body 604 and the inner diameter E of the discharge pipe 650 is preferably about 0.5 to 0.6.

  Note that the swirl unit 620 is worn and worn by long-term use because plant exhaust gas including coarse particle dust and medium particle dust collides with it, so that a maintenance work for replacing the swirl unit 620 is required. Below, the attachment / detachment method of the turning part 620 at the time of a maintenance is demonstrated.

  FIG. 13 is a diagram for explaining a method for attaching and detaching the swivel unit 620 when the plant P is closed. As shown in FIG. 13, a plurality of suspension pieces 670 are provided inside the entrance bell 612, and when the swivel part 620 is removed during maintenance work during a wind break, first, a chain is attached to the suspension piece 670. The block 672 is suspended, and the wire rope 674 fed out from the chain block 672 holds the ring portion 622 at the position indicated by A in FIG. Next, the bolt which fixes the 2nd flange part 626 of the ring part 622 (swivel part 620) to the entrance bell 612 is removed (refer FIG.12 (b)), Furthermore, the division | segmentation rings 622a-622d adjacent to the circumferential direction are removed. The bolt connecting the first flange portion 624 is removed (see FIG. 12A), and the ring portion 622 (the turning portion 620) is divided into divided rings 622a to 622d.

  Then, the wire rope 674 is fed out, and the split rings 622a to 622d are lowered in the vertical chamber tube body 604 in the order shown by B and C in FIG. At this time, the temporary beam 676 and the temporary bracket 678 are taken in from the maintenance opening 680 provided in the lower portion of the vertical chamber tube 604 after the wind is suspended, and installed in the lower portion of the vertical chamber tube 604. The split rings 622 a to 622 d are placed on 676.

  A maintenance opening 680 is provided at a lower portion of the vertical chamber tube 604, and the split rings 622a to 622d are connected to the vertical chamber tube 604 from the maintenance opening 680 as indicated by D in FIG. You just take out sequentially. Here, the case where the swivel unit 620 is taken out from the vertical chamber tube body 604 has been described. However, when the swivel unit 620 is installed in the vertical chamber tube body 604, the reverse procedure may be performed.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the above-described embodiment, the second swirl space 336 has been described as an example of a configuration having a smaller diameter than the first swirl space 316. However, the volume of the second swirl space 336 may be smaller than that of the first swirl space 316, and the circumference may be smaller than that of the first swirl space 316.

  In the above-described embodiment, the configuration in which the dust chamber 334a is provided inside the conical tube 334 has been described as an example. However, the shape of the dust chamber 334a is not limited, and may be, for example, a cylindrical shape. In any case, it is only necessary that the lower ends of the plurality of second tubular bodies 332 are positioned in the dust chamber 334a.

  Moreover, in the said embodiment, the cleaning apparatus 100 demonstrated and demonstrated the structure provided with the pre-duster 200 as an example. However, when the amount of dust in the plant exhaust gas is small or when the dust particles are fine, the preduster 200 may not be provided, and the dust collector 300 alone may be used.

  Moreover, you may comprise a preduster by the cyclone dust collector which isolate | separates dust from plant exhaust gas by swirling plant exhaust gas and centrifuging.

  INDUSTRIAL APPLICABILITY The present invention can be used in a plant exhaust gas cleaning device and a cleaning method for obtaining clean gas by removing dust in plant exhaust gas generated in a plant.

100 Cleaning device 200, 600 Preduster 210 Pre-pipe body 230 Discharge pipe 230a Suction port 300, 400, 500 Dust collector 310 Upstream cyclone part 312 First pipe body 316 First swirling space 320 Communication pipe 320a Main body part 320b Inlet port 320d Port 330 Downstream cyclone section 332 Second pipe body 332d Opening 334 Conical pipe 334a Dust chamber 336 Second swirl space 370 Exhaust pipe 372 Collecting discharge section 604 Vertical chamber tube body 608 Swirling flow path 620 Swirling section 650 Discharge pipe

Claims (12)

An upstream cyclone unit having a first pipe body in which a first swirling space in which plant exhaust gas generated in the plant is introduced and in which the plant exhaust gas swirls is formed;
The plant exhaust gas introduced from the first swirl space swirls, and has a plurality of second tubular bodies formed therein with a second swirl space having a smaller diameter or volume than the first swirl space, A downstream cyclone section in which the plant exhaust gas swirling in the swirling space is guided to the plurality of second pipes;
With
At least a part of the downstream cyclone unit is located in the first pipe body, and the apparatus for purifying plant exhaust gas is characterized in that:   The plurality of second tubular bodies are characterized in that at least part of the second tubular bodies protrudes into the first swirling space from above the first tubular body, or the whole is located in the first swirling space. The plant exhaust gas cleaning device according to claim 1. The first swirl space has a circular horizontal cross-sectional shape,
The plant exhaust gas cleaning apparatus according to claim 2, wherein the plurality of second pipe bodies are arranged so as to surround a center position of the first swirl space. A communication pipe that guides plant exhaust gas from the first swirl space to the second swirl space is provided at the center position of the first swirl space surrounded by the plurality of second pipe bodies,
The communication pipe is
The main body,
An inlet that is formed at the lower end of the main body and introduces the plant exhaust gas swirled in the first swirl space into the main body;
A diversion port that is introduced into the main body from the introduction port and diverts the plant exhaust gas that rises up the main body to guide the plurality of second pipes;
The plant exhaust gas cleaning apparatus according to claim 3, comprising:   The plant exhaust gas cleaning apparatus according to claim 4, wherein a lower end of the main body portion in which the introduction port is formed has a shape in which a diameter gradually increases toward a tip.   The plant exhaust gas cleaning device according to any one of claims 1 to 5, further comprising a collective discharge unit that collects and exhausts the plant exhaust gas swirled in the plurality of second swirl spaces to the outside. . The collective discharge unit is
An exhaust pipe in which at least the lower end is disposed in the second pipe body, and the plant exhaust gas rises from the bottom toward the top;
The plant exhaust gas cleaning apparatus according to claim 6, wherein the lower end of the exhaust pipe has a shape in which a diameter gradually increases toward the front end. The lower end of the second tubular body is provided with an opening for vertically discharging the dust centrifuged from the plant exhaust gas in the second swirl space,
A conical tube in which the lower ends of a plurality of the second tube bodies are located inside the first tube body, and a dust chamber for storing dust discharged from an opening at the lower end of the second tube body is formed in the first tube body The plant exhaust gas cleaning device according to any one of claims 2 to 7, wherein the plant exhaust gas cleaning device is provided. A pre-duster for roughly collecting dust from the plant exhaust gas,
The plant exhaust gas cleaning apparatus according to any one of claims 1 to 8, wherein plant exhaust gas roughly collected by the pre-duster is introduced into the upstream cyclone unit. The pre-duster is
A pre-pipe body in which a pre-swirl space in which the plant exhaust gas swirls is formed;
A suction port for guiding plant exhaust gas is formed at one end, and a discharge pipe for positioning the one end in the pre-pipe body;
The plant exhaust gas cleaning device according to claim 9. The pre-duster is
A vertical chamber tube;
An annular swirl passage formed in the vertical chamber tube;
A swirl unit for guiding and swirling plant exhaust gas from the outside of the vertical chamber tube to the swirl flow path;
A suction pipe formed at one end, the discharge pipe positioning the one end in the vertical chamber tube;
The plant exhaust gas cleaning device according to claim 9. Swirling the plant exhaust gas in the first swirl space and removing dust from the plant exhaust gas by centrifugation;
The plant exhaust gas from which dust has been removed in the first swirl space is swirled in a second swirl space having a diameter or volume smaller than that of the first swirl space, and removed from the plant exhaust gas by centrifugal separation in the first swirl space. Removing dust that is smaller than the dust,
A method for cleaning plant exhaust gas, comprising:

Images