JP2017000952A - Discharge electrode of electric dust collector for processing diesel engine exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge electrode capable of properly setting arrangement of an electrode needle to a main electrode in predetermined density, and effective even for a high temperature countermeasure by attempting weight reduction and shape maintenance of the electrode needle, even if an outer diameter is changed to a large diameter in a collection pipe of a tubular collection part of an electric dust collector for processing Diesel engine exhaust gas.SOLUTION: A discharge electrode of a Diesel engine exhaust gas processing device comprises a tubular collection part composed of a main electrode and a discharge electrode electrified in particulate matter included in exhaust gas of a Diesel engine using heavy oil and a dust collecting electrode for collecting the electrified particulate matter, in which a tubular collection module being a short dimension and different in a diameter is arranged in a plurality of stages in the axial direction in the tubular collection part, and is constituted by arranging a short size discharge electrode needle or a low height saw blade-shaped discharge electrode plate in a radial shape on the outer periphery of a cylindrical discharge electrode support cylinder installed on the outer periphery of the main electrode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrical processing technology for exhaust gas using corona discharge in diesel engines such as marine, power generation, and general industrial engines, and in particular, exhausts high-temperature exhaust gas using lower quality fuel than heavy oil. The present invention relates to a discharge electrode of an electric dust collector for exhaust gas treatment of a diesel engine.

  Diesel engines are widely used as power sources for various ships, generators, large construction machines, and various automobiles. PM (particulate matter) contained in exhaust gas discharged from diesel engines is well known. In addition to causing air pollution, it is extremely harmful to the human body, so purification of the exhaust gas is extremely important. For this reason, many proposals have already been made, such as improvement of the combustion method of diesel engines, the use of various exhaust gas filters, and a method of electrical treatment using corona discharge, some of which have been put into practical use.

Among them, as a technique for electrically processing using corona discharge, for example, an apparatus described in Patent Document 1 has been proposed.
As shown in FIG. 10, the diesel engine exhaust gas treatment device described in Patent Document 1 that uses low-quality fuel equal to or lower than heavy oil has a tubular collection part 91 made up of a discharge electrode and a dust collection electrode. This is an example of a multi-stage system composed of a combination of a plurality of tubular collection modules that are short in the axial direction and have different diameters. Specifically, the tubular collection module is collected from the upstream side of the tubular collection part with a smaller diameter. The unit 91-1A, the medium-diameter collecting unit 91-1B, and the large-diameter collecting unit 91-1C are three-stage types.
That is, the diesel engine exhaust gas treatment apparatus in which the tubular collection portion is a multistage system is a small-diameter collection fixed to the collection pipe 91-1 as the first-stage small-diameter tubular collection module on the most upstream side. A small-diameter collecting portion 91-1A in which the radial first stage discharge electrode 91-1A-2 held inside the tube 91-1A-1 is fixed to the common main electrode 91-2a, and the second stage As a medium-diameter tubular collection module, the radial second stage discharge electrode 91-1B-2 held inside the intermediate-diameter collection tube 91-1B-1 is fixed to the common main electrode 91-2a. The inside of the large-diameter collecting tube 91-1C-1 common with the collecting tube 91-1 as the medium-diameter collecting portion 91-1B and the third-stage largest diameter tubular collecting module on the most downstream side The radial third stage discharge electrode 91-1C-2 held on the inner side is fixed to the common main electrode 91-2a. Is obtained by a large 径捕 collection part 91-1C was. Each discharge electrode 91-1A- of the small diameter collection part 91-1A, the medium diameter collection part 91-1B, and the large diameter collection part 91-1C in the diesel engine exhaust gas treatment apparatus having the three-stage tubular collection module. 2, 91-1B-2, 91-1C-2, as shown in enlarged view in FIG. 11A, FIG. 11B, and FIG. 12, the axial center vicinity of the collection tube 91-1 constituting the dust collection electrode is almost full length. And a group of radially projecting electrode needles 91-2b disposed at a desired interval S ′ in the longitudinal direction of the main electrode 91-2a. . Specifically, as shown in FIG. 12, the discharge electrode 91-2 includes a substrate portion 91-2f in which, for example, a sawtooth-shaped discharge plate portion (mountain portion) 91-2e extends in the axial direction of the main electrode 91-2a. A saw blade-shaped discharge electrode plate 91-2d provided integrally with the main electrode 91-2a through the substrate is protruded from the main electrode 91-2a through the substrate portion 91-2f. Has been. The discharge electrode 91-2 configured as described above is provided at the inlet portion of the low-concentration exhaust gas outlet tube 92 and the seal air inlet tube portion 91-1c provided on the exhaust gas inlet 91-1a side of the collection tube 91-1. Both ends of the main electrode 91-2a are supported via a support body 93 suspended from the provided seal air introduction pipe portion 91-1c.

  The cyclone type separation and collection means 94 provided between the downstream side and the upstream side of the tubular collection unit 91 includes a cyclone collection unit 94-1 and a reflux pipe 94 from the cyclone collection unit 94-1. -2. This cyclone collection part 94-1 is connected to the high concentration exhaust gas pipe 95 provided in the high concentration exhaust gas outlet part 91-1b provided near the inner peripheral surface on the downstream side of the collection pipe 91-1 of the tubular collection part 91. It is constituted by a tangential cyclone 94-3 connected through a reflux pipe 94-2, and further, purification after passing through the tangential cyclone 94-3 between the tangential cyclone 94-3 and the exhaust gas introduction pipe 91-1a. A reflux pipe 94-2 is provided for merging the gas with the exhaust gas flowing in the exhaust gas introduction pipe 91-1a. 96 is a blower, 97 is a flow control damper.

JP 2014-238086 A

However, the discharge electrode 91-2 in the above-described conventional diesel engine exhaust gas purification apparatus (multistage type) that electrically processes PM in the exhaust gas using corona discharge or the like has the following problems. .
That is, for example, in the case of the discharge electrode 91-2 shown in FIGS. 11A, 11B, and 12, the sawtooth-shaped discharge plate portion (mountain portion) 91-2e extends in the axial direction of the main electrode 91-2a. Since the saw-tooth discharge electrode plate 91-2d provided integrally with the main electrode 91-2a through 2f projects from the main electrode 91-2a through the substrate portion 91-2f. When the outer diameter of the collecting tube 91-1 of the tubular collecting portion 91 is increased, the interval W ′ between the tip of the electrode needle 91-2b (saw blade-shaped discharge electrode plate 91-2d) and the collecting wall surface 91-1k is set. In order to maintain a desired dimension, when the radial length H ′ of the corresponding electrode needle 91-2b is increased and the rigidity is lowered and the rigidity is ensured, not only the weight is heavy, but usually the electrode needle Is manufactured with an ultra-thin plate with a thickness of about 0.5 mm. In particular, problems such as thermal deformation occur when exposed to high temperatures. Further, in order to eliminate a dead spot having a weak electric field in this dust collecting portion and maintain a predetermined discharge current density, it is necessary to keep the circumferential interval L ′ at the tip of the electrode needle 91-2b substantially constant to a desired dimension, As a result, when the outer diameter of the collection tube 91-1 of the tubular collection portion 91 is increased, the number (number) of electrode needles 91-2b must be increased. However, when the required number (number) of electrode needles 91-2b increases, the mounting area to the main electrode 91-2a per electrode needle (one) inevitably decreases, and the main electrode 91-2a is moved to. It becomes difficult to secure the strength.
Furthermore, in the case of the above-described conventional long (long needle) electrode needle 91-2b (saw blade-shaped discharge electrode plate 91-2d), the electric field at the tip of the electrode needle is strong, but the electric field at the surface of the collection wall is weak and PM trapping is performed. Since the electric field of the entire collection space (the space between the electrode needle tip and the collection wall) is weak, it is easy to make a dead spot, the Coulomb force acting on the PM is weak, and the collection rate cannot be improved. There is a drawback that a jumping phenomenon (a phenomenon in which PM repeatedly accumulates and peels) on the collection wall of the separated PM is difficult to appear.

  The present invention has been made in order to overcome the above-described problems of the prior art, and in particular, the tubular collection portion in which the tubular collection portion made of the discharge electrode and the dust collection electrode is made short in the axial direction and has a different diameter. In a multistage diesel engine exhaust gas treatment system configured by combining multiple modules in the axial direction, the electric field and coulomb force in the PM collection space is enhanced to improve the PM collection rate, and the tubular collection Even if the outer diameter of the collection tube of the part increases, the arrangement of the electrode needles with respect to the main electrode can be set appropriately with a predetermined density, and the rigidity of the electrode needles can be maintained to reduce the weight and maintain the shape. The present invention intends to provide a discharge electrode that is also effective against high temperatures.

  The discharge electrode of the diesel engine exhaust gas treatment electrostatic precipitator according to the present invention includes a discharge electrode for charging particulate matter contained in the exhaust gas of a diesel engine using heavy oil, and a collector for collecting the charged particulate matter. A tubular collecting portion having a predetermined length constituting a dust electrode, and the discharge electrode protrudes radially inside the tubular collecting portion and a main electrode disposed in the tube axis direction and disposed on the main electrode. An electric dust collecting means composed of an electrode, and the discharge electrode and the dust collecting electrode having a single diameter and a main collecting tube having a predetermined length and having a short diameter in the axial direction and a diameter. Discharge electrodes of a diesel engine exhaust gas treatment device in which different tubular collection modules are arranged in a plurality of stages, wherein the discharge electrodes of at least one tubular collection module of the tubular collection modules arranged in the plurality of stages are arranged on the outer periphery of the main electrode Ste The main electrode and the concentric cylindrical discharge electrode support tube attached via the electrode, and a short discharge radially arranged on the surface of the discharge electrode support tube with a desired interval in the circumferential direction and the tube axis direction It is composed of an electrode needle or a low height sawtooth discharge electrode plate, and the radial length of the short discharge electrode needle or low height sawtooth discharge electrode plate is 10 to 30 mm. The distance between the tip of the sawtooth discharge electrode plate and the collection wall surface is 30 to 70 mm, and the upstream opening end of the discharge electrode support cylinder of the most upstream tubular collection module of the tubular collection part is It is characterized by being blocked.

  The discharge electrode of another diesel engine exhaust gas treatment electrostatic precipitator according to the present invention includes a discharge electrode for charging a particulate material contained in exhaust gas of a diesel engine using heavy oil, and the charged particulate material. A tubular collecting part having a predetermined length constituting a dust collecting electrode to be collected is provided, and the discharge electrode is disposed in the tubular collecting part in a tube axis direction and the main electrode. An electrostatic dust collecting means composed of radially projecting electrodes, and the discharge electrode and the dust collecting electrode having a single diameter and a predetermined length of a main collecting tube having a short length in the axial direction. Discharge electrode of a diesel engine exhaust gas treatment device in which tubular collecting modules having different sizes and diameters are arranged in three stages, a small-diameter collecting part, an intermediate-diameter collecting part, and a large-diameter collecting part from the upstream side of the tubular collecting part The tubular collection module arranged in the three stages A discharge electrode of at least one tubular collection module attached to the outer periphery of the main electrode via a stay, a concentric cylindrical discharge electrode support tube, a circumferential direction on the surface of the discharge electrode support tube, and It is composed of short discharge electrode needles or low height sawtooth discharge electrode plates arranged radially at desired intervals in the tube axis direction, and the short discharge electrode needle or low height sawtooth discharge. The length of the electrode plate in the radial direction is 10 to 30 mm, the distance between the tip of the discharge electrode needle or the low-height sawtooth discharge electrode plate and the collection wall surface is 30 to 70 mm, and the most upstream of the tubular collection part The upstream opening end of the discharge electrode support tube of the tubular collection module is closed.

  In the electric dust collector for exhaust gas treatment of diesel engine according to the present invention, at least one of the tubular collection modules arranged in a plurality of stages or three stages includes a dust collection electrode comprising a discharge electrode and a main collection tube, It is a preferable aspect to comprise.

  Further, the short discharge electrode needle or the low-height saw blade-shaped discharge electrode plate provided radially on the outer periphery of the discharge electrode support tube is a discharge electrode needle or saw having an apex angle of about 20 degrees and a substantially isosceles triangle shape. It is preferable that it is constituted by a blade-like discharge electrode plate, a cone edge ring type discharge electrode plate or a cylindrical edge ring. In addition, as a space | interval of the front-end | tip of an adjacent discharge electrode needle | hook or a saw-tooth-shaped discharge electrode plate, 10-50 mm is preferable.

A discharge electrode of an electric dust collector for exhaust gas treatment of a diesel engine according to the present invention is a tubular collection module in which a tubular collection portion comprising a discharge electrode and a collection electrode is made short in the axial direction and has a different diameter. Discharge electrode of at least one tubular collection module of an electrostatic precipitator having a multi-stage dust collecting wall structure configured by combining a plurality of axially in the axial direction, and a discharge electrode having a cylindrical shape concentric with the main electrode mounted on the outer periphery of the main electrode A short discharge electrode needle or low-height sawtooth discharge electrode plate is attached to the support cylinder, and the length of the discharge electrode needle or sawtooth discharge electrode plate is optimized, that is, the conventional long length By shortening the length, the electric field between the tip of the electrode needle or electrode plate and the collection wall increases, the amount of corona electrons emitted from the tip of the discharge electrode increases, the dead spot decreases, and the Coulomb force increases. Rate increases Minara not a, occurs jumping phenomenon in a collecting wall of PM peeled from collection wall, the cyclone collector is made possible via the branch flow path by coarsening of PM.
Further, in the case of this short discharge electrode needle or saw blade-shaped discharge electrode plate, a discharge electrode support cylinder having an appropriate size corresponding to the diameter is used even if the collection tube of the tubular collection portion has a large diameter. Thus, the distance between the tip of the discharge electrode needle or discharge electrode plate and the inner wall of the collection tube can be set to a desired appropriate size without increasing the axial length of the discharge electrode needle or discharge electrode plate. In addition to maintaining the rigidity of the electrode needle and reducing the weight, it is possible to maintain the shape because the electrode needle or the electrode plate does not undergo large thermal deformation even when exposed to high temperatures. Furthermore, the arrangement of the electrode needles and electrode plates with respect to the main electrode can be appropriately set at a predetermined density, and the attachment of the electrode needles and electrode plates to the main electrodes is facilitated. In addition, if the discharge electrode support cylinder does not have a through-hole, the gas flow that flows outside and inside the cylinder is blocked. It contributes to the improvement.

1 is a schematic longitudinal end view showing a basic structure of a discharge electrode of an electric dust collector for exhaust gas treatment of a diesel engine according to the present invention. It is a schematic longitudinal side view of the discharge electrode shown in FIG. It is a figure which shows an example of the discharge electrode plate of the discharge electrode shown in FIG. 1, (a) is a front view of a cone edge ring type discharge electrode plate, (b) is a longitudinal side view on the (a) easy line. It is a figure which shows the other example of the cone edge ring type discharge electrode plate shown in FIG. 3, (a) is a front view, (b) is a vertical side view on (a) Rollo line. It is a figure which shows the modification of the cone edge ring-type discharge electrode plate shown in FIG. 4, (a) is a front view, (b) is a vertical side view on (a) Haha line. It is a vertical side view which shows another example of the discharge electrode plate of the discharge electrode shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic vertical end view of a main part showing a first embodiment (multistage dust collecting wall structure) of a discharge electrode of an electric dust collector for treating exhaust gas from a diesel engine according to the present invention. It is a principal part general | schematic longitudinal end view which shows 2nd Example (multistage type dust-collecting wall structure) of the discharge electrode of the diesel engine exhaust gas process electric dust collector which concerns on this invention. It is a principal part general | schematic longitudinal end view which shows 3rd Example (multistage type dust collecting wall structure) of the discharge electrode of the diesel engine exhaust gas process electric dust collector which concerns on this invention. It is a schematic longitudinal cross-sectional view which shows an example of the diesel engine exhaust gas processing apparatus of the conventional multistage type dust collecting wall structure. It is a schematic longitudinal end view which expands and shows the discharge electrode of the diesel engine exhaust gas processing apparatus shown in FIG. It is a schematic longitudinal side view which expands and shows the discharge electrode of the diesel engine exhaust gas processing apparatus shown in FIG. It is a schematic perspective view which expands and shows the discharge electrode of the diesel engine exhaust gas processing apparatus shown in FIG.

  The discharge electrode 1 of the tubular collection module of the present invention shown in FIGS. 1 and 2 has a main electrode (electrode bar) 2 and the main electrode 2 with a desired interval in the circumferential direction and tube axis direction on the outer periphery. The discharge electrode support cylinder 3 has short discharge electrode needles 6 arranged radially, and the discharge electrode support cylinder 3 is configured to be concentrically attached to the main electrode 2 via a plurality of stays 5. . Here, as the size (diameter) of the discharge electrode support tube 3, the length of the discharge electrode needle 6 or the tip of the discharge electrode needle 6 is selected according to the diameter of the main electrode (electrode bar) 2 or the inner diameter of the collection tube 7. In consideration of the distance W to the collection wall surface, an appropriate size is set. Note that the means for attaching the discharge electrode support tube 3 to the main electrode 2 is not limited to a method of attaching the discharge electrode support tube 3 directly to the main electrode 2 via a plurality of stays 5 provided radially, for example, a support ring fitted to the main electrode 2. (Drawing is omitted) and a mounting method using a stay 5 may be adopted, and the stay 5 may be a plate-like or rod-like one. When a plate-like stay is used, the main electrode 2 is used. Attach to the outer peripheral surface of the main electrode 2 in the tube axis direction, and when using a rod-shaped one, attach it at a desired interval in the circumferential direction of the main electrode 2 and the tube axis direction.

As the short discharge electrode needle 6 projecting radially on the outer periphery of the discharge electrode support cylinder 3, a plate-like member having an apex angle of about 20 degrees and a substantially isosceles triangle shape can be used, for example. The length (discharge length from the outer peripheral surface of the discharge electrode support cylinder 3) H of the discharge electrode needle 6 is 10 to 30 mm. The reason is that if it is less than 10 mm, the peak electric field for corona discharge at the tip of the discharge electrode needle 6 is weak and the Coulomb force cannot be increased and it is difficult to increase the adhesion to the collecting wall surface. This is because the peak electric field increases, but the average electric field decreases, and the Coulomb force is increased to make it difficult to increase the adhesion to the collecting wall surface.
The short discharge electrode needles 6 project radially from the outer periphery of the discharge electrode support tube 3 at a desired tip interval S in the axial direction of the main electrode 2 and at a desired interval L in the circumferential direction. Further, the axial distance S between the tips of the adjacent discharge electrode needles 6 is not particularly limited, but is usually preferably 10 to 50 mm. The reason for this is that if it is less than 10 mm, the electric field is low and the Coulomb force cannot be increased and it is difficult to increase the adhesion to the collecting wall. On the other hand, if it exceeds 50 mm, there are many dead points where the electric field is weak and the average electric field decreases. This is because it is difficult to increase the coulomb force and increase the adhesion to the collection wall surface.
The distance W from the tip of the discharge electrode needle 6 to the collection wall surface (inner wall surface) of the collection tube 7 is set to 30 to 70 mm. The reason for this is that if the length is less than 30 mm, the tip of the discharge electrode needle 6 may be in contact with or interfere with the collection wall surface (inner wall surface) of the collection tube 7 during assembly, and discharge may occur during operation due to ship hulls or engine vibrations. The tip of the electrode needle 6 is easy to contact and interfere with the collection wall surface (inner wall surface) of the collection tube 7, and on the other hand, if it exceeds 70 mm, the discharge interval is wide, so a high electric field is maintained and a large Coulomb force is obtained. This is because a high voltage / high output power source is required and high voltage is required, so that high insulation is required for each part, which makes the apparatus expensive and requires a lot of man-hours for maintenance and management.
The radius R of the discharge electrode support cylinder 3, the length H of the discharge electrode needle 6, the circumferential interval L of the discharge electrode needle 6, the tip of the discharge electrode needle 6 and the collecting wall surface (inner wall surface) of the collecting tube 7 The distance W is determined appropriately according to the scale of the diesel engine exhaust gas treatment device, the arrangement position of the tubular collection module, the size (diameter) of the collection tube 7 constituting the dust collection electrode, and the like. In particular, the length H of the discharge electrode needle 6 is set in consideration of the relationship with the collection wall surface electric field of the collection tube 7.

  In addition, as the discharge electrode in the present invention, instead of the discharge electrode needle 6 shown in FIGS. 1 and 2, for example, the cone edge ring type discharge electrodes 16, 26, and 36 shown in FIGS. A cylindrical edge ring type discharge electrode plate 46 shown in FIG. 6 can be used. The cone edge ring-shaped discharge electrode 16 shown in FIG. 3 includes a ring having a cone-shaped ring-shaped edge portion 16-1 on the outer periphery, and the cone-edge ring-shaped discharge electrode 26 shown in FIG. 4 has a cone-shaped ring-shaped edge. A ring having a leak hole 26-2 for reducing exhaust gas flow resistance at the edge portion on the peripheral wall portion of the portion 26-1, and varying the phase of the circumferential position of the leak hole 26-2. The cone edge ring-shaped discharge electrode 36 shown in FIG. 5 is composed of a ring having a leak hole 36-2 larger than the leak hole 26-2 on the peripheral wall portion of the cone-shaped ring edge portion 36-1, The cone edge ring type discharge electrode 16 and the cone edge ring type discharge electrode 26 are combined. These cone edge ring type discharge electrodes 16, 26, and 36 are fitted and fixed to the discharge electrode support tube 3 with a desired number of gaps as required, so that the outer periphery of the discharge electrode support tube 3 is fixed. The cone-shaped ring-shaped edge portions 16-1, 26-1, and 36-1 can be projected radially. In the case of the cone edge ring discharge electrodes 16, 26, 36, the lengths of the cone edge portions 16-1, 26-1, 36-1 of the discharge electrode support cylinder 3 are the discharges shown in FIGS. The length H of the electrode needle 6 and the interval between the edge portions 16-1, 26-1, 36-1 of the adjacent cone edge ring discharge electrodes 16, 26, 36 are respectively set to the interval S of the tip of the discharge electrode needle 6. Correspondingly the same length.

  Further, in the cylindrical edge ring type discharge electrode 46 shown in FIG. 6, the cylindrical end ring part 46-2 is circumferentially bent at one end of the cylindrical part part 46-1, preferably at an acute angle. The peripheral edge of the ring-shaped edge portion 46-3 is formed from a thin plate or tube material having a thickness of about 0.5 mm. In the case of the cylindrical edge ring type discharge electrode 46, the edge part 46-2 is fitted to the outer periphery of the discharge electrode support cylinder 3 by fitting and fixing the cylinder part 46-1 to the discharge electrode support cylinder 3 so as to contact each other. Are projected radially. In the case of this cylindrical edge ring type discharge electrode 46, the length of the edge ring portion 46-2 is equal to the length H of the discharge electrode needle 6 shown in FIGS. 1 and 2, and the adjacent cylindrical edge ring type discharge electrode. The interval between the 46 edge ring portions 46-2 corresponds to the interval S between the tips of the discharge electrode needles 6 and has the same length. Here, the cylindrical edge ring type discharge electrode formed by combining a plurality of single cylindrical electrode plates is shown, but the strip plate having the edge ring portion 46-2 is spirally formed on the discharge electrode support cylinder 3. A cylindrical edge ring discharge electrode (not shown) may be formed by winding.

  In the case of the discharge electrode of the present invention having the above-described configuration, a short discharge electrode needle 6 or a cone edge ring type discharge electrode 16 is attached to a discharge electrode support cylinder 3 concentrically cylindrical with the main electrode 2 mounted on the outer periphery of the main electrode 2. , 26, 36 and the cylindrical edge ring discharge electrode 46, the discharge electrode support cylinder having a size corresponding to the size (diameter) of the collection tube 7 of the tubular collection module is increased. 3, the rigidity of the electrode needle or the electrode plate is remarkably increased and the deformation resistance against vibrations and the like is increased, so that the durability is not only ensured but also the electrode needle or the electrode plate is exposed to a high temperature. The shape is maintained without significant thermal deformation, and the ring-shaped edge is continuous in the circumferential direction, so it is difficult to generate a dead point with a weak electric field, and it is possible to increase the discharge current effectively. Electric Strength increases, the particles are collected to give a Coulomb force is reliably charged. Further, the distance W between the tip of the short discharge electrode needle 6 or the cone edge ring type discharge electrodes 16, 26, 36 and the cylindrical edge ring type discharge electrode 46 and the inner wall of the collecting tube 7 is set to a desired appropriate dimension. Therefore, the high rigidity of the discharge electrode needle or the discharge electrode plate is maintained and the weight can be reduced. Furthermore, the arrangement of the electrode needle 6, the cone edge ring discharge electrodes 16, 26, 36 and the cylindrical edge ring type discharge electrode 46 with respect to the main electrode 2, that is, the short discharge electrode needle 6, the cone edge ring type discharge electrodes 16, 26, 36, or the length H of the cylindrical edge ring discharge electrode 46, the axial distance S and the circumference of the tip of the discharge electrode needle 6, the cone edge ring discharge electrodes 16, 26, 36, or the cylindrical edge ring discharge electrode 46. The direction interval L can be appropriately set at a predetermined density to prevent the generation of a dead point with a weak electric field, and the short discharge electrode needle 6 and the cone edge ring discharge electrodes 16, 26, 36 with respect to the main electrode 2 or a cylindrical shape. The attachment of the edge ring discharge electrode 46 is also facilitated. Further, if the discharge electrode support cylinder 3 does not have a through-hole, the discharge electrode support cylinder 3 blocks the flow of the gas flow flowing outside and inside the cylinder, and thus has an effect of preventing undesired vortex and turbulent flow for dust collection. It also contributes to improving the rate.

  Next, a discharge electrode in which the discharge electrode of the present invention is applied to an electric dust collector for exhaust gas treatment of a diesel engine having a multistage dust collecting wall will be described with reference to FIGS.

  The diesel engine exhaust gas treatment electric dust collector shown as the first embodiment (multistage dust collecting wall structure) in FIG. 7 includes a tubular collecting module disposed in the main collecting tube 51 on the upstream side of the tubular collecting portion. In the diesel engine exhaust gas treatment apparatus which is a three-stage type of a small diameter collecting unit 51-1, a medium diameter collecting unit 51-2, and a large diameter collecting unit 51-3, the small diameter collecting unit 51-1 is being excluded. Discharge electrode 51-2A-1 composed of a short discharge electrode needle or a low-height sawtooth discharge electrode plate similar to the above in the diameter collection part 51-2 and the large diameter collection part 51-3, 51-3A-1 is arranged and configured.

  The discharge electrode 51-2A-1 disposed in the medium-diameter collecting tube 51-2A of the medium-diameter collecting portion 51-2 is formed on the outer circumference of the main electrode (electrode bar) 52 in the circumferential direction and the tube axis direction. A discharge electrode support cylinder 51-2A-1d having a radius R of 300 mm and having a short discharge electrode needle 51-2A-1c having a length H of 10 to 30 mm arranged radially at intervals, and supporting the discharge electrode The cylinder 51-2A-1d is configured to be concentrically attached to the main electrode 52 via a plurality of stays 51-2A-1e. The distance W from the tip of the discharge electrode needle 51-2A-1c to the collection wall surface (inner wall surface) of the medium diameter collection tube 51-2A is 30 to 70 mm.

  Further, the discharge electrode 51-3A-1 disposed in the large-diameter collecting tube portion 51-3A common to the main collecting tube 51 of the large-diameter collecting portion 51-3 is the medium-diameter collecting portion 51-2. Like the discharge electrode support cylinder 51-2A-1d of the discharge electrode 51-2A-1 disposed in the outer periphery of the main electrode (electrode bar) 52 in a radial manner with a desired interval in the circumferential direction and the tube axis direction. A discharge electrode support cylinder 51-3A-1d having a radius R of 400 mm and a short discharge electrode needle 51-3A-1c having a length H of 10 to 30 mm arranged, and the discharge electrode support cylinder 51-3A-1d. Are also concentrically attached to the main electrode 52 via a plurality of stays 51-3A-1e. The distance W from the tip of the discharge electrode needle 51-3A-1c to the collection wall surface (inner wall surface) of the large-diameter collection tube portion 51-3A common to the main collection tube 51 is 30 to 70 mm as described above. is there.

  In addition, the discharge electrode 51-1A-1 arrange | positioned in the small diameter collection tube 51-1A of the small diameter collection part 51-1 is radially arrange | positioned on the outer periphery of the main electrode (electrode rod) 52 at a desired space | interval. Short discharge electrode needles 51-1A-1c.

  In the figure, 51-4 is a main electrode support, 51-5 is a low concentration exhaust gas outlet pipe, and 51-6 is a high concentration exhaust gas outlet.

  An electric dust collector for diesel engine exhaust gas treatment shown as a second embodiment (multi-stage dust collecting wall structure) in FIG. 8 includes a tubular collection module disposed in the main collection pipe 61 on the upstream side of the tubular collection section. In the diesel engine exhaust gas treatment apparatus that is a three-stage system including a smaller-diameter collection unit 61-1, an intermediate-diameter collection unit 61-2, and a large-diameter collection unit 61-3, the small-diameter collection unit 61-1, Discharge electrodes 61-1A-1 and 61 composed of a short discharge electrode needle or a low-height sawtooth discharge electrode plate similar to those described above in the collection unit 61-2 and the large-diameter collection unit 61-3. -2A-1 and 61-3A-1 are arranged. Here, discharge electrode 61-1A-1 arrange | positioned in the small diameter collection tube 61-1A of the small diameter collection part 61-1 is the main electrode (electrode bar) like the discharge electrode which has the same structure as the above. Discharge electrode support cylinder having a radius R of 200 mm and having short discharge electrode needles 61-1A-1c having a length H of 10 to 30 mm radially arranged on the outer periphery of 62 at a desired interval in the circumferential direction and the tube axis direction. 61-1A-1d, and the discharge electrode support cylinder 61-1A-1d has a conical lid 61- at the upstream opening end for preventing the exhaust gas from flowing into the discharge electrode support cylinder. 1A-1d ′ is formed to close the end portion, and is concentrically attached to the main electrode 62 via a plurality of stays 61-1A-1e. The distance W from the tip of the discharge electrode needle 61-2A-1c to the collection wall surface (inner wall surface) of the small-diameter collection tube 61-1A is 30 to 70 mm. The reason why the closed portion is configured by the conical lid portion is to make the flow of the exhaust gas in the collection pipe 61 smooth without resistance.

  Further, the discharge electrode 61-2A-1 disposed in the medium diameter collection tube 61-2A of the medium diameter collection portion 61-2 is disposed in the circumferential direction and the tube axis direction on the outer periphery of the main electrode (electrode bar) 62. A discharge electrode support cylinder 61-2A-1d having short discharge electrode needles 61-2A-1c arranged radially at a desired interval, the discharge electrode support cylinder 61-2A-1d being an upstream end portion. And has a truncated conical portion 61-2A-1d ', and is concentrically attached to the main electrode 62 via a plurality of stays 61-2A-1e.

  Furthermore, the discharge electrode 61-3A-1 disposed in the large-diameter collecting tube portion 61-3A of the large-diameter collecting portion 61-3 is the discharge electrode 61 disposed in the medium-diameter collecting portion 61-2. Similar to the discharge electrode support cylinder 61-2A-1d of -2A-1, short discharge electrode needles radially arranged on the outer periphery of the main electrode (electrode bar) 62 at a desired interval in the circumferential direction and the tube axis direction The discharge electrode support cylinder 61-3A-1d having 61-3A-1c, and this discharge electrode support cylinder 61-3A-1d is also the discharge electrode support cylinder 61-2A-1d of the medium diameter collecting portion 61-2. In the same manner as described above, the upstream conical portion has a truncated conical portion 61-3A-1d 'and is concentrically attached to the main electrode 62 via a plurality of stays 61-3A-1e. .

  In the figure, 61-4 is a main electrode support, 61-5 is a low concentration exhaust gas outlet pipe, and 61-6 is a high concentration exhaust gas outlet.

An electric dust collector for diesel engine exhaust gas treatment shown as a third embodiment (multi-stage dust collecting wall structure) in FIG. 9 is a small-diameter trap of the diesel engine exhaust gas treatment electrostatic dust collector of the second embodiment shown in FIG. In addition to the collector 61-1, between the small-diameter collecting tube 71-1A and the main collecting tube 71, a discharge electrode 71-4A composed of a short discharge electrode needle or a low-height sawtooth discharge electrode plate on both the inner and outer surfaces. Except that the discharge electrode support cylinder 71-4A-1d having -1 is provided, this is an electric dust collector for exhaust gas treatment of a diesel engine having the same configuration as that of the second embodiment.
That is, in this apparatus, the tubular collection module disposed in the main collection tube 71 is arranged with a small-diameter collection unit 71-1, a medium-diameter collection unit 71-2, and a large-diameter collection from the upstream side of the tubular collection unit. In the diesel engine exhaust gas treatment apparatus having a three-stage configuration of the section 71-3, the small diameter collecting section 71-1, the medium diameter collecting section 71-2, and the large diameter collecting section 71-3 have the same short length as described above. Discharge electrode 71-1A-1, 71-2A-1, 71-3A-1 comprised by the discharge electrode needle | hook of this, or a low height saw-tooth shaped discharge electrode plate, and is comprised. Here, discharge electrode 71-1A-1 arrange | positioned in the small diameter collection tube 71-1A of the small diameter collection part 71-1 is the main electrode (electrode rod) like the discharge electrode which has the same structure as the above. A discharge electrode support cylinder having a radius R of 200 mm and having short discharge electrode needles 71-1A-1c having a length H of 10 to 30 mm radially arranged on the outer periphery of 72 at a desired interval in the circumferential direction and the tube axis direction. The discharge electrode support cylinder 71-1A-1d is composed of 71-1A-1d, and the discharge electrode support cylinder 71-1A-1d has a conical lid 71- at the upstream opening end for preventing the exhaust gas from flowing into the discharge electrode support cylinder. 1A-1d ′ is formed to close the end portion, and is attached concentrically to the main electrode 72 via a plurality of stays 71-1A-1e. The distance W from the tip of the discharge electrode needle 71-1A-1c to the collection wall surface (inner wall surface) of the small diameter collection tube 71-1A is 30 to 70 mm. The apparatus further includes a discharge electrode 71-4A- consisting of a short discharge electrode needle or a low height saw-blade discharge electrode plate on both the inner and outer surfaces between the small-diameter collection tube 71-1A and the main collection tube 71. 1 is attached concentrically to the main electrode 72 via a stay 71-4A-1e. The discharge electrode support cylinder 71-4A-1d is provided between the small-diameter collecting tube 71-1A and the main collecting tube 71 for a total of 2 degrees in the exhaust gas flow outward from the small-diameter collecting tube 71-1A. This is to promote the agglomeration, concentration and separation of PM by charging and collecting the particles.

  In addition, the discharge electrode 71-2A-1 disposed in the medium diameter collecting tube 71-2A of the medium diameter collecting portion 71-2 is arranged on the outer periphery of the main electrode (electrode bar) 72 in the circumferential direction and the tube axis direction. A discharge electrode support cylinder 71-2A-1d having a radius R of 300 mm and having a short discharge electrode needle 71-2A-1c having a length H of 10 to 30 mm arranged radially at a desired interval; The electrode support cylinder 71-2A-1d has a frustoconical portion 71-2A-1d 'at the upstream end, and is attached concentrically to the main electrode 72 via a plurality of stays 71-2A-1e. Configured.

  Furthermore, the discharge electrode 71-3A-1 disposed in the large-diameter collection tube portion 71-3A of the large-diameter collection portion 71-3 is the discharge electrode 71 disposed in the medium-diameter collection portion 71-2. Similarly to the discharge electrode support cylinder 71-2A-1d of -2A-1, the length H arranged radially on the outer periphery of the main electrode (electrode bar) 72 at a desired interval in the circumferential direction and the tube axis direction is 10 A discharge electrode support tube 71-3A-1d having a radius R of 400 mm having a short discharge electrode needle 71-3A-1c of ˜30 mm, and the discharge electrode support tube 71-3A-1d is also the medium diameter collecting portion Similarly to the discharge electrode support cylinder 71-2A-1d of 71-2, the upstream end portion has a truncated conical portion 71-3A-1d ′, and the main electrode is connected via a plurality of stays 71-3A-1e. It is configured to be attached concentrically with the electrode 72.

  In the figure, 71-4 is a main electrode support, 71-5 is a low concentration exhaust gas outlet pipe, and 71-6 is a high concentration exhaust gas outlet.

  In addition, the discharge electrode of the above-described multi-stage diesel engine exhaust gas treatment electrostatic precipitator in which the tubular collection modules having different sizes and different diameters in the tube axis direction are arranged in a plurality of stages, that is, the outer periphery of the main electrode A cylindrical discharge electrode support tube attached to the surface of the discharge electrode support tube, a short discharge electrode needle radially disposed on the surface of the discharge electrode support tube with a desired interval in the circumferential direction and the tube axis direction, or The discharge electrode composed of a low-height sawtooth discharge electrode plate is the size of the electric dust collector for exhaust gas treatment of the diesel engine, the size of the main collection tube (tube diameter, etc.), and the cross-sectional shape of the main electrode It goes without saying that the cross-sectional shape and size of the discharge electrode support cylinder, discharge electrode needle or low height saw-blade discharge electrode plate are selected according to the diameter and the diameter.

1, 51-1A-1, 51-2A-1, 51-3A-1, 61-1A-1, 61-2A-1, 61-3A-1, 71-1A-1, 71-2A-1, 71-3A-1, 71-4A-1 Discharge electrode 2, 52, 62, 72 Main electrode (electrode bar)
3, 51-2A-1d, 51-3A-1d, 61-1A-1d, 61-2A-1d, 61-3A-1d, 71-1A-1d, 71-2A-1d, 71-3A-1d, 71-4A-1d Cylindrical discharge electrode support cylinder 5, 51-2A-1e, 51-3A-1e, 61-1A-1e, 61-2A-1e, 61-3A-1e, 71-2A-1e, 71-3A-1e, 71-4A-1e Stay 6, 51-1A-1c, 51-2A-1c, 51-3A-1c, 61-1A-1c, 61-2A-1c, 61-3A-1c, 71-1A-1c, 71-2A-1c, 71-3A-1c Discharge electrode needle 7 Collection tube 16 Cone edge ring discharge electrode 16-1 Ring-shaped edge portion 26 Cone edge ring discharge electrode 26-1 Ring-shaped edge portion 26-2 Leak hole 36 Jilling discharge electrode 36-1 Ring-shaped edge portion 36-2 Leakage hole 46 Cylindrical edge ring-shaped discharge electrode 46-1 Tube body portion 46-2 Edge ring portion 46-3 Ring-shaped edge portions 51, 61, 71 Main collection Pipes 51-1, 61-1 and 71-1 Small-diameter collecting parts 51-1A, 61-1A and 71-1A Small-diameter collecting pipes 51-2, 61-2 and 71-2 Medium-diameter collecting parts 51-2A 61-2A, 71-2A Medium diameter collecting pipe 51-3, 61-3, 71-3 Large diameter collecting part 51-3A, 61-3A, 71-3A Large diameter collecting pipe part 51-4, 61-4, 71-4 Main electrode support 51-5, 61-5, 71-5 Low concentration exhaust gas outlet pipe 51-6, 61-6, 71-6 High concentration exhaust gas outlet 61-1A-1d ', 71-1A-1d ′, conical lid portions 61-2A-1d ′, 61-3A-1d ′, 71-2A-1d ′, 1-3A-1d 'frustoconical section S axial distance between discharge electrode needle tips L circumferential distance between discharge electrode needle tips H length of discharge electrode needles W distance between discharge electrode needle tips and collection wall surface R Radius of discharge electrode support tube

An electric dust collector for diesel engine exhaust gas treatment shown as a third embodiment (multi-stage dust collecting wall structure) in FIG. 9 is a small-diameter trap of the diesel engine exhaust gas treatment electrostatic dust collector of the second embodiment shown in FIG. In addition to the collector 61-1, between the small-diameter collecting tube 71-1A and the main collecting tube 71, a discharge electrode 71-4A composed of a short discharge electrode needle or a low-height sawtooth discharge electrode plate on both the inner and outer surfaces. Except that the discharge electrode support cylinder 71-4A-1d having -1 is provided, this is an electric dust collector for exhaust gas treatment of a diesel engine having the same configuration as that of the second embodiment.
That is, in this apparatus, the tubular collection module disposed in the main collection tube 71 is arranged with a small-diameter collection unit 71-1, a medium-diameter collection unit 71-2, and a large-diameter collection from the upstream side of the tubular collection unit. In the diesel engine exhaust gas treatment apparatus having a three-stage configuration of the section 71-3, the small diameter collecting section 71-1, the medium diameter collecting section 71-2, and the large diameter collecting section 71-3 have the same short length as described above. Discharge electrode 71-1A-1, 71-2A-1, 71-3A-1 comprised by the discharge electrode needle | hook of this, or a low height saw-tooth shaped discharge electrode plate, and is comprised. Here, discharge electrode 71-1A-1 arrange | positioned in the small diameter collection tube 71-1A of the small diameter collection part 71-1 is the main electrode (electrode rod) like the discharge electrode which has the same structure as the above. A discharge electrode support cylinder having a radius R of 200 mm and having short discharge electrode needles 71-1A-1c having a length H of 10 to 30 mm radially arranged on the outer periphery of 72 at a desired interval in the circumferential direction and the tube axis direction. The discharge electrode support cylinder 71-1A-1d is composed of 71-1A-1d, and the discharge electrode support cylinder 71-1A-1d has a conical lid 71- at the upstream opening end for preventing the exhaust gas from flowing into the discharge electrode support cylinder. 1A-1d ′ is formed to close the end portion, and is attached concentrically to the main electrode 72 via a plurality of stays 71-1A-1e. The distance W from the tip of the discharge electrode needle 71-1A-1c to the collection wall surface (inner wall surface) of the small diameter collection tube 71-1A is 30 to 70 mm. The apparatus further includes a discharge electrode 71-4A- consisting of a short discharge electrode needle or a low height saw-blade discharge electrode plate on both the inner and outer surfaces between the small-diameter collection tube 71-1A and the main collection tube 71. 1 is attached concentrically to the main electrode 72 via a stay 71-4A-1e. Incidentally, provision of the discharge electrode supporting tube 71-4A-1d between the small-diameter collecting tube 71-1A and the main collecting tube 71 is small collection outward exhaust gas flow from the small-diameter collecting tube 71-1A Part 71-1 and medium diameter collection part 71-2 and / or large diameter collection part 71-3 at least twice in total (between the small diameter collection tube 71-1A and the discharge electrode support cylinder 71-4A-1d). This is because the exhaust gas passing through the middle-diameter collecting pipe 71-2A is repeatedly charged and collected three times to further promote the agglomeration, concentration and separation of PM.

Claims (4)

  A discharge electrode for charging the particulate matter contained in the exhaust gas of a diesel engine using heavy oil, and a tubular collecting part of a predetermined length constituting a dust collecting electrode for collecting the charged particulate matter, and The discharge electrode includes an electric dust collecting means constituted by a main electrode disposed in a tube collecting direction in a tubular collecting portion and a radially projecting electrode disposed on the main electrode. Discharge of diesel engine exhaust gas treatment equipment in which tubular collection modules with a short diameter in the axial direction and different diameters are arranged in multiple stages in a tubular collection part consisting of a main collection pipe of a single diameter and a predetermined length which is a dust electrode A discharge electrode having a cylindrical shape concentric with the main electrode in which the discharge electrode of at least one of the tubular collection modules arranged in a plurality of stages is attached to the outer periphery of the main electrode via a stay A support tube and the discharge A short discharge electrode needle or a low-height sawtooth discharge electrode plate arranged radially on the surface of the support cylinder at desired intervals in the circumferential direction and the tube axis direction, and the short discharge electrode needle Alternatively, the radial length of the low-height sawtooth discharge electrode plate is 10 to 30 mm, and the distance between the tip of the discharge electrode needle or the low-height sawtooth discharge electrode plate and the collecting wall surface is 30 to 70 mm, A discharge electrode of an electrostatic precipitator for exhaust gas treatment of a diesel engine, wherein an upstream opening end of the discharge electrode support cylinder of the most upstream tubular collection module of the tubular collection unit is closed.   A discharge electrode for charging the particulate matter contained in the exhaust gas of a diesel engine using heavy oil, and a tubular collecting part of a predetermined length constituting a dust collecting electrode for collecting the charged particulate matter, and The discharge electrode includes an electric dust collecting means constituted by a main electrode disposed in a tube collecting direction in a tubular collecting portion and a radially projecting electrode disposed on the main electrode. A tubular collection module having a single diameter and a main collection pipe having a predetermined length, which is a dust electrode, is connected to a tubular collection module having a small diameter and a different diameter in the axial direction from the upstream side of the tubular collection section. A discharge electrode of a diesel engine exhaust gas treatment device arranged in three stages with a collecting part, a medium diameter collecting part, and a large diameter collecting part, wherein the discharge electrode of the tubular collecting module arranged in the three stages is an outer periphery of the main electrode A concentric cylindrical release with the same main electrode attached to the An electrode support cylinder, and short discharge electrode needles or low-height sawtooth discharge electrode plates radially arranged on the surface of the discharge electrode support cylinder at desired intervals in the circumferential direction and the tube axis direction. And the radial length of the short discharge electrode needle or low-height sawtooth discharge electrode plate is 10 to 30 mm, and the tip of the discharge electrode needle or low-height sawtooth discharge electrode plate and the collecting wall surface An electric current collector for exhaust gas treatment of a diesel engine, characterized in that the upstream opening end of the discharge electrode support cylinder of the tubular collecting module at the uppermost stream of the tubular collecting part is closed at an interval of 30 to 70 mm. Dust device discharge electrode.   The at least one tubular collection module of the tubular collection modules arranged in a plurality of stages or three stages is constituted by a discharge electrode and a dust collection electrode comprising a main collection tube. The discharge electrode of the electrostatic precipitator for diesel engine exhaust gas treatment of description.   The short discharge electrode needle or the low-height saw blade-shaped discharge electrode plate provided radially on the outer periphery of the discharge electrode support cylinder is composed of a cone edge ring or a cylindrical edge ring. The discharge electrode of the electrostatic dust collector for diesel engine exhaust gas treatment of any one of 3.

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