WO2012066825A1

WO2012066825A1 - Exhaust gas processing device for diesel engine

Info

Publication number: WO2012066825A1
Application number: PCT/JP2011/067318
Authority: WO
Inventors: 宗勝古堅; 義牧野; 滝川　一儀
Original assignee: 臼井国際産業株式会社
Priority date: 2010-11-16
Filing date: 2011-07-28
Publication date: 2012-05-24
Also published as: CN103261596A; CN103261596B; EP2642095A4; JP5863087B2; KR20130087566A; EP2642095B1; JP2012107556A; KR101423016B1; EP2642095A1

Abstract

Provided is an exhaust gas purifying device for a diesel engine, such that the size of a cyclone can be reduced, and a high particulate matter (PM) collection rate and low fuel consumption can be achieved. This exhaust gas processing device for a diesel engine comprises: a tubular collection unit comprising a discharge electrode for electrically charging particulate matter contained in the exhaust gas of a diesel engine that uses fuel of quality less than or equal to that of fuel oil, and a collector electrode for collecting the electrically charged particulate matter; and a cyclone-type separation and collection means for selecting and collecting the particulate matter that has peeled off from the tubular collection unit. The exhaust gas processing device is characterized in that a cyclone collection means constituted of one or more tangential cyclones is provided to a high-concentration exhaust gas discharging section for discharging exhaust gas with a high particulate matter concentration, the high-concentration exhaust gas discharging section being located in the vicinity of an inner surface of a downstream portion of the tubular collection unit, and a stream of high-concentration gas discharged from the high-concentration exhaust gas discharging section is selectively introduced to the tangential cyclone(s) according to the flow rate of the exhaust gas.

Description

Diesel engine exhaust gas treatment equipment

The present invention removes particulate matter (Particulate Matter: hereinafter referred to as “PM”) mainly composed of carbon contained in exhaust gas of a diesel engine and harmful gas, particularly for ships, power generation, industrial use, etc. More particularly, the present invention relates to an exhaust gas processing device using corona discharge in a large displacement diesel engine that discharges exhaust gas at a high temperature.

Diesel engines are widely used as power sources for various ships, generators, large construction machines, and various automobiles, but as is well known, PM contained in exhaust gas discharged from diesel engines is air pollution. In addition to toxic substances, it is a substance that 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 improvements in the combustion system of diesel engines, the use of various exhaust gas filters, and methods of electrical treatment using corona discharge, some of which have been put into practical use. .

Here, components of PM (particulate matter) in exhaust gas of a diesel engine are organic solvent soluble (SOF: Soluble Organic Fractions, hereinafter referred to as “SOF”) and organic solvent insoluble (ISF: Insoluble Organic). Fractions (hereinafter referred to as “ISF”), of which SOF is mainly composed of unburned fuel and lubricating oil, and harmful substances such as polycyclic aromatics that have a carcinogenic effect. included. On the other hand, the ISF component is mainly composed of carbon (soot) and sulfate (sulfate) components having low electrical resistivity. The SOF component and the ISF component are affected as much as possible because of their effects on the human body and the environment. Less exhaust gas is desired. In particular, it is also said that the degree of adverse effects of PM in a living body is particularly problematic when the particle diameter is nm.

For example, methods and apparatuses described below (Patent Documents 1 to 5) have been proposed as a method of performing electrical treatment using corona discharge.

That is, in Patent Document 1, as schematically shown in FIG. 12, a discharge charging unit 22 including a corona discharge unit 22-1 and a charging unit 22-2 is connected to the exhaust gas passage 21 to corona discharge. The charged electrons 29 are charged to the PM 28 mainly composed of carbon in the exhaust gas G 1, and the charged PM 28 is collected by the collection plate 23 disposed in the exhaust gas passage 21. The electrode needle 24 has a short length in the flow direction of the exhaust gas flow, and the collecting plate 23 is arranged in a direction perpendicular to the flow direction of the exhaust gas flow. Methods and apparatus have been proposed. In the figure, 25 is a seal gas pipe, 26 is a high voltage power supply device, and 27 is an exhaust gas induction pipe.

In Patent Document 2, as schematically shown in FIG. 13, a needle electrode 31 for charging a PM 33 in exhaust gas by causing a corona discharge 35 around the needle tip 31-1, and a charged PM 33 Exhaust gas trapping of a diesel engine provided with a collecting electrode 32 for collecting the gas and a high-voltage DC power source 34 for applying a predetermined DC high voltage between the needle electrode 31 and the collecting electrode 32 A collecting device has been proposed. In the figure, 36 is a deflection electrode.

Further, in Patent Document 3, as schematically shown in FIG. 14, a fixed cylindrical body 41 that constitutes one of a collection electrode pair for collecting PM provided in an exhaust path, and a center of the fixed cylindrical body 41. The electrode rod 42 extending in the axial direction at the portion and constituting the other of the collection electrode pair, and an electrostatic field is formed between the collection electrode pair to accumulate PM in the exhaust gas on the inner surface of the fixed cylindrical body 41. Exhaust gas purification provided with a high voltage power supply unit 43 and a scraping unit 44 that rotates relative to the fixed cylindrical body along the inner surface of the fixed cylindrical body 41 to scrape PM accumulated on the inner surface of the fixed cylindrical body. A device has been proposed. In the figure, 45 is an exhaust pipe, and 46 is a rotating cylindrical part.

On the other hand, Patent Document 4 discloses a discharge electrode for charging PM contained in exhaust gas of a diesel engine, an electric dust collection means having a dust collection electrode for collecting charged PM, and a dust collection electrode. Engine exhaust gas purification device provided with means for separating the PM accumulated from the dust collecting electrode and a cyclone-type separation collecting means for separating and collecting the PM peeled from the dust collecting electrode has been proposed .
As shown in FIG. 15, this apparatus is configured to process exhaust gas while flowing in the lateral direction, and serves as an electric dust collector 51 for collecting PM and a separate collector. The electrostatic dust collecting portion 51 is a collection of a cylindrical metal body 57 attached to the inner peripheral surface of the cylindrical housing 56 and an uneven portion 58 formed on the inner peripheral surface of the cylindrical metal body. The dust electrode 54, a main electrode 59 extending along the axis of the dust collection electrode 54, and a group of radially projecting electrode needles 60 disposed at predetermined intervals in the longitudinal direction of the main electrode 59. The cyclone 52 is configured at a downstream side of the guide vane 61 that converts the flow of the gas flow 53 that has passed through the electrostatic precipitator 51 into a swirl flow, and the cyclone is disposed downstream of the cyclone 52. The gas inside An exhaust pipe 62 of the eye, a hopper 63 for collecting PM, which is centrifuged is provided. A separation mechanism 64 separates the PM collected and collected by the dust collection electrode 54 from the dust collection electrode 54, and includes, for example, an eccentric motor 65 that generates vibration due to eccentricity. Reference numeral 66 denotes an extraction pipe for returning the exhaust gas in the exhaust pipe 62 to the upper space of the hopper 63.
That is, in the exhaust gas purification apparatus having the above-described configuration, PM in the exhaust gas flowing into the electric dust collector 51 is charged by the discharge between the dust collection electrode 54 and the discharge electrode 55 and captured by the dust collection electrode 54 by the Coulomb force. The collected and collected PM flows into the guide vane 61 together with the gas flow, and the PM is centrifuged by the cyclone 52 formed at the downstream side of the guide vane 61. The centrifuged PM is put into the hopper 63. On the other hand, the exhaust gas that has fallen and was collected and purified is discharged to the outside through the exhaust pipe 62.

Further, Patent Document 5 includes a charge aggregation portion that collects and aggregates the components to be collected in the exhaust gas of a diesel engine mounted on an automobile by corona discharge, and a filter portion that collects the aggregated components. As shown in FIGS. 16 and 17, the gas aggregating unit 70 is arranged on the upstream side and the filter unit 80 is arranged on the downstream side as shown in FIGS. The dust collecting electrode of the low voltage electrode is formed by the conductive cylindrical body 71f formed by the

bodies

71, 71a, etc., and disposed in the vicinity of the surface of the gas passage wall, and is disposed inside these cylindrical bodies. A corona electrode is formed by a high-voltage electrode of a linear body, and a cylindrical body of the gas passage wall is formed as a gas cooling portion that cools the gas by natural convection and heat radiation, and further, the gas passage wall Cylindrical body or the conductive cylindrical body To gas flow through the vicinity of the inner surface, the means for accelerating turbulence 71e to promote turbulence, the gas processing devices constituting provided on the surface or near the surface of the tubular body is shown. In the figure, 71c is a gas inlet chamber, 71b is a corona electrode, and 71d is a gas outlet chamber.

WO2006 / 064805B JP-A-9-112246 Japanese Patent Laid-Open No. 6-173637 JP 2006-136766 A Japanese Patent No. 4529013

However, the above-described conventional diesel engine exhaust gas purification apparatus has the following drawbacks.
That is, in the electric processing method and apparatus for exhaust gas of a diesel engine described in Patent Document 1, the electrode needle 24 in the discharge charging unit 22 is short in the flow direction of the exhaust gas flow, and the collection plate 23 is exhausted. It is arranged in a direction perpendicular to the flow direction of the gas flow, and the exhaust gas flow is in direct contact with the collection plate 23, so that the flow resistance (pressure loss; pressure loss) is large, the collection plate 23 is thin and exhausted. Since the flow direction length of the gas flow is short, there is a concern that the PM may pass through, and there is a possibility that the PM collection efficiency cannot be sufficiently increased. The PM once passed through the collection plate 23 is charged again by corona discharge. There is a problem that it is feared that it will be collected without being collected.
In Patent Document 1, the collecting plate has a long tube shape in the flow direction of the exhaust gas flow, and an electrode needle is provided in the tube axis direction of the tubular collection portion, so that the PM particles flow in the flow of the exhaust gas flow. In addition to increasing the particle size of PM in the vicinity of the inner surface of the tubular collection part of the exhaust gas flow so that it can be easily collected by a cyclone. The technical idea of increasing the concentration of PM and selectively extracting the exhaust gas stream having a large PM particle size and concentrated to a high concentration and collecting them with a cyclone is not disclosed or suggested. .

In addition, the exhaust PM collection device described in Patent Document 2 and the exhaust gas purification device described in Patent Document 3 set both voltages to appropriate conditions because the discharge voltage and the collection deflection voltage are the same potential. In order to prevent the occurrence of sparks between the deflection electrode and the collection electrode, it is necessary to increase the distance between the deflection electrode and the collection electrode, and for this reason, the PM passing through the collection section without being collected increases. In order to reduce the collection efficiency, and to increase the collection efficiency, it is necessary to increase the capacity of the collection section. It has the disadvantage that it is.
In Patent Document 2, the collection electrode 32 is a tunnel-like electrode that serves as an exhaust passage, and an electrode assembly of the needle electrode 31 and the deflection electrode 36 is formed in the tunnel of the collection electrode 32. The shaft center is arranged in a substantially common manner, and a thick and long electrode assembly is inserted in almost the entire length of the tubular collecting portion to form a lattice shape. In the paragraph [0033] of the sixth embodiment, “...... the electrode rod 42 constituting one of the discharge electrode pair and the collection electrode pair is suspended along the center line of the fixed cylindrical body 41... A large-diameter exhaust port is provided on the side surface, and a downstream exhaust pipe 45 is fitted into the exhaust port .... "Paragraph [0035] states that" the rotating cylindrical portion 46 has a truncated conical shape with a small diameter at the bottom. ... A long bar (scraping part) 4 upward from the inner surface of the rotating cylindrical part 46 ”And the outer edge of the bar 44 is in contact with the inner surface of the large diameter portion of the fixed cylindrical body 41,” paragraph [0036] states that “...... diesel particulate is the electrode rod 42 in the discharge space. The charged diesel particulates are ... attracted by an electrostatic field and are deposited on the inner surface of the large diameter portion of the fixed cylinder 41. " Further, in paragraph [0037], “a diesel particulate layer deposited on the inner surface of the large-diameter portion as the bar 44 rotates at a low speed in contact with the inner surface of the large-diameter portion of the fixed cylindrical body 41 as the rotating cylindrical portion 46 rotates. The diesel particulates that fall are collected in a collection box and can be removed ... "and a tubular collection part is formed, but it is described in Patent Document 3. Things are collecting electrodes A fixed cylindrical portion (tubular) that is long in the flow direction of the exhaust gas flow is provided, and an electrode needle is provided while maintaining an interval in the tube axis direction of the tubular collection portion, so that PM flows in the flow direction of the exhaust gas flow. This is a technique for depositing and scraping the deposited PM particles with a bar, and a part of the PM particles scattered when scraped off is a downstream exhaust fitted into a large exhaust port provided in front of the collection box. It is a technology that is highly concerned about being discharged from the pipe.
Therefore, in the techniques described in

Patent Documents

2 and 3, as in the technique described in Patent Document 1, the collecting plate has a tubular shape that is long in the flow direction of the exhaust gas flow. An electrode needle is provided in the direction of the tube axis of the tube, and the growth is caused by a jumping phenomenon that repeats deposition and separation while flowing PM particles in the flow direction of the exhaust gas flow. The particle size of PM is coarsened so that it can be easily collected by a cyclone, the concentration of PM is increased, and the exhaust gas stream having a large particle size and concentrated at a high concentration is selectively selected. The technical idea of extracting and collecting efficiently with a cyclone is neither disclosed nor suggested.

On the other hand, in the diesel engine exhaust gas purification device described in Patent Document 4, the PM particles collected on the dust collection electrode 54 of the electric dust collection unit 51 and the inner peripheral wall surface (collection tube wall) of the cylindrical housing 56 are large. A lump is formed, and the PM lump is separated from the dust collecting electrode 54 and the collecting tube wall by a natural peeling or mechanical peeling mechanism and mixed in the cylindrical housing 56, and the separated and lumped PM lump is discharged into the exhaust gas. In this system, the cyclone 52 is centrifuged and collected again in the hopper 63. In this system, the exhaust gas is discharged into the cyclone 52 by the guide vane 61 that is mixed in the exhaust gas amount disposed in the cylindrical housing 56. Therefore, a large cyclone 52 having a large guide vane 61 is inevitably required to centrifugate PM by flowing the entire amount, and the equipment cost and running cost are high. In addition, since a plurality of cyclones 52 cannot be installed structurally, it is not possible to cope with a large increase / decrease in the exhaust gas flow rate due to the increase / decrease in the number of operating engines or a large change in the engine load factor, and the exhaust gas from the cyclone introduction part Since there is no means for appropriately controlling the flow velocity, there are disadvantages that a high PM collection rate is maintained and problems such as deterioration in fuel consumption due to excessive pressure loss in the cyclone cannot be solved.
In Patent Document 4, the collection plate has a long tubular shape in the flow direction of the exhaust gas flow, an electrode needle is provided in the tube axis direction of the tubular collection portion, and the PM particles are flowed in the exhaust gas flow. While flowing in the direction, the material is deposited near the inner surface of the tubular collecting part and collected by a cyclone. However, the technique described in Patent Document 4 is similar to the technique described in Patent Documents 1 to 3 in the exhaust gas. The particle size of the gas flow PM is coarsened so that it can be easily collected by a cyclone, and the concentration of PM in the vicinity of the inner surface of the tubular collection portion of the exhaust gas flow is increased. However, there is no disclosure or suggestion of a technical idea of selectively extracting only the flow in the vicinity of the inner surface of the tubular collection portion of the exhaust gas flow concentrated to a high concentration and collecting it intensively with a cyclone.

Further, the gas processing apparatus described in Patent Document 5 is a small vehicle-mounted gas processing apparatus, which is configured by disposing the charging aggregation unit 70 on the upstream side and the filter unit 80 on the downstream side. A gas inlet chamber 71c that divides exhaust gas into a large number is provided in the agglomeration portion 70, and a gas passage wall is formed of a cylindrical body 71f. 71f is a technology related to a device that forms a gas cooling part that cools a gas by natural convection and natural heat dissipation by heat radiation, and then remixes the separated exhaust gas in a gas outlet chamber 71d, and flows out from the tubular collecting part. This is different from a technique (the present invention described later) in which the exhaust gas is not remixed before the PM particle collecting step. The gas processing apparatus described in Patent Document 5 is provided with a turbulent flow promoting means 71e for the gas flow on the inner surface of the cylindrical body 71f or in the vicinity of the inner surface, and particularly the turbulent flow of gas near the surface of the cylindrical body. This has the disadvantage that the agitation action is promoted to increase the stirring action in the cross-sectional direction of the flow path.
In addition, the thing of this patent document 5 provides an electrode needle in the tube-axis direction of this tubular collection part while making a collection wall into the tubular cylindrical body long in the flow direction of exhaust gas flow, PM Although the particles are collected while being collected in the vicinity of the inner surface of the tubular collecting portion while flowing in the flow direction of the exhaust gas flow, this Patent Document 5 is also similar to Patent Documents 1 to 4 in that the PM of the exhaust gas flow is collected. The particle size of the exhaust gas is coarsened so as to be easily collected by a cyclone installed on the downstream side, and the concentration of PM in the vicinity of the inner surface of the tubular collection part of the exhaust gas flow is increased. In addition, the technical idea of selectively extracting only the flow in the vicinity of the inner surface of the tubular collecting portion of the exhaust gas flow having a high PM concentration and collecting it in a concentrated manner with a cyclone is not disclosed or suggested.

The present invention was made in order to eliminate the above-mentioned drawbacks of the prior art, and in particular, the diesel engine exhaust gas purification described in Patent Document 4 in which a guide vane is arranged in a passage through which the total exhaust gas amount flows to constitute a cyclone. Instead of the system of the apparatus, a system in which the cyclone type separation and collection means is arranged not in the tubular collection part but on the downstream side of the tubular collection part, and the cyclone collection means is constituted by a plurality of tangential cyclones. By adopting it, the cyclone can be miniaturized, and the exhaust gas flow rate can be greatly reduced due to changes in the operating status due to the parallel operation and independent operation of the main engine and auxiliary equipment in the marine engine and large fluctuations in the load factor of the engine. It is possible to appropriately select and use cyclones according to the increase and decrease, and further by providing means for appropriately controlling the exhaust gas flow velocity in the cyclone introduction section. , It is intended to provide a diesel engine exhaust gas purification device capable of solving the problems of deterioration of fuel efficiency by excessive pressure loss in maintaining a high PM collection efficiency and the exhaust gas purifying apparatus.

A diesel engine exhaust gas purifying apparatus according to the present invention constitutes a discharge electrode for charging PM contained in exhaust gas of a diesel engine using heavy fuel or lower quality fuel, and a dust collecting electrode for collecting the charged PM. A tubular collecting portion having a predetermined length, and the discharge electrode includes a main electrode disposed in the tube axial direction in the tubular collecting portion, and a plurality of radially projecting radially spaced spaces between the main electrodes. In the diesel engine exhaust gas treatment apparatus, comprising: an electric dust collecting means constituted by an electrode needle; and a cyclone type separation collecting means for separating and collecting PM separated from the tubular collection section, the tubular collection section A PM low concentration exhaust gas outlet pipe is provided in the vicinity of the shaft center on the downstream side, and a high concentration exhaust gas outlet section is provided in the vicinity of the inner peripheral surface on the downstream side of the tubular collection part. The The cyclone collecting means to be collected is connected continuously, the cyclone collecting means is constituted by a tangential cyclone, and the opening degree of the damper disposed in the low-concentration exhaust gas outlet pipe is controlled to thereby connect the cyclone collecting means to the tangential cyclone. It is a mechanism for controlling the exhaust gas inflow speed. Needless to say, low-concentration exhaust gas is exhaust gas having a low PM content (purified exhaust gas), and high-concentration exhaust gas is exhaust gas containing a large amount of PM.

Further, the apparatus of the present invention comprises the cyclone collecting means constituted by a plurality of tangential cyclones, and the high concentration exhaust gas discharged from the high concentration exhaust gas deriving section is selectively selected according to the flow rate of the exhaust gas. It is characterized in that it becomes a method to be introduced into.

In the device according to the present invention, the tubular collecting portion has a tapered tubular portion that expands in a tapered shape at a downstream end portion thereof, and a large-diameter tubular portion that is continuous with the tapered tubular portion, and an axial center of the large-diameter tubular portion It is a preferable aspect that a low concentration exhaust gas outlet pipe and a high concentration exhaust gas outlet portion are connected in the vicinity of the inner peripheral surface of the large diameter tubular portion.

Further, it is preferable that the discharge electrode is extended to the tapered tubular portion of the tubular collection portion or the region of the tapered tubular portion and the large-diameter tubular portion connected to the tapered tubular portion. is there.

The apparatus according to the present invention is preferably configured such that the cyclone collecting means includes a plurality of tangential cyclones having different processing capacities, and a flow rate control damper is provided at an inlet of each tangential cyclone. Between the tangential cyclone and the low-concentration exhaust gas outlet pipe, an exhaust pipe for merging the purified gas after passing the tangential cyclone with the low-concentration exhaust gas is provided, and an air nozzle or a motor-driven fan is provided in the exhaust pipe. It is a preferred embodiment to have a configuration in which is arranged.

Furthermore, in the device according to the present invention, the tubular collecting part is arranged substantially horizontally, or the tubular collecting part is arranged substantially vertically and upward, or the tubular collecting part is substantially vertical and downward. It is a preferred embodiment that they are arranged in the above.

The diesel engine exhaust gas purification apparatus according to the present invention employs a method of centrifuging PM outside the tubular collection unit, so that PM in the exhaust gas is collected on the tubular collection wall surface in the tubular collection unit. It becomes a lump, and the PM lump is gradually condensed and concentrated in the vicinity of the tubular collecting wall surface while repeatedly adhering to and peeling from the tubular collecting wall surface, thereby forming an exhaust gas stream containing high concentration of PM. It flows downstream and is separated into a high-concentration exhaust gas of PM and a low-concentration exhaust gas containing only a low concentration of PM by gradually diluting the PM in the vicinity of the axial center of the tubular collection unit. , PM high-concentration exhaust gas flows in the vicinity of the tubular collection wall surface, and PM low-concentration exhaust gas flows in the vicinity of the axial center of the tubular collection part, so only high-concentration exhaust gas enriched in PM is tubular Collection wall It can be derived from the vicinity of the cyclone collecting means. That is, according to the apparatus of the present invention, only a high concentration exhaust gas of PM can be guided to the cyclone although it is a part of the total exhaust gas amount, the cyclone can be downsized. On the other hand, low-concentration exhaust gas (purified exhaust gas) in which PM has been diluted is discharged to the outside from a low-concentration exhaust gas outlet pipe connected in the vicinity of the shaft center on the downstream side of the tubular collection part.

Further, according to the apparatus of the present invention, the cyclone collecting means is constituted by a plurality of tangential cyclones, and the high concentration exhaust gas of PM discharged from the high concentration exhaust gas deriving section is selectively selected according to the flow rate of the exhaust gas. By adopting a method of introducing into a cyclone type cyclone, the “flow-in” of a tangential type cyclone with superior collection performance compared to the axial flow type cyclone of the diesel engine exhaust gas purification device described in Patent Document 4 in which a guide vane is disposed. In addition to the effect that the trapping efficiency increases when the tangential speed of the fluid is high, the exhaust due to changes in the operating status of the marine engine due to the parallel operation or independent operation of the main engine and auxiliary machinery, or large fluctuations in the load factor of the engine The processing capacity and number of tangential cyclones can be selected appropriately according to the significant increase / decrease in gas flow rate, and the PM is high in response to changes in exhaust gas flow rate. It is possible to ensure the Atsumariritsu. Furthermore, since the exhaust gas inflow rate (tangential velocity) to the tangential cyclone can be properly controlled by controlling the opening degree of the damper disposed in the low concentration exhaust gas outlet pipe, a high collection rate of PM In addition, problems such as deterioration in fuel consumption due to excessive pressure loss in the exhaust gas purification apparatus can be solved.

The diesel engine exhaust gas purification apparatus according to the present invention is also provided with a tapered tubular portion that expands in a tapered shape on the downstream side of the tubular collection portion or a large-diameter tubular portion that continues to the tapered tubular portion. PM is gradually decelerated by the tapered tubular portion, and PM can be reliably introduced into the high-concentration exhaust gas deriving portion connected to the inner peripheral surface of the large-diameter tubular portion. Furthermore, the PM is more effectively captured by adopting a configuration in which the discharge electrode is extended to the vicinity of the inner peripheral surface of the tapered tubular portion of the tubular collecting portion and the large-diameter tubular portion region connected to the tapered tubular portion. The exhaust gas can be collected and the exhaust gas can be further purified.

Furthermore, in the present invention apparatus, the cyclone collecting means is composed of a plurality of tangential cyclones having different processing capacities, for example, three types of cyclones: a small processing capacity tangential cyclone, a medium processing capacity tangential cyclone, and a large processing capacity tangential cyclone. In addition, by providing a flow control damper at the inlet of each tangential cyclone, exhaust gas due to changes in operating conditions due to parallel operation or independent operation of the main engine and auxiliary machinery in marine engines and large fluctuations in the engine load factor Not only can the tangential cyclones be selected and used more appropriately according to the significant increase / decrease in the flow rate, but also the flow control provided for each tangential cyclone in combination with the damper installed in the low concentration exhaust gas outlet pipe. By controlling the damper, the exhaust gas inflow rate to each tangential cyclone can be controlled more appropriately. . Furthermore, a discharge pipe is provided between the tangential cyclone and the low-concentration exhaust gas outlet pipe to join the purified gas after passing the tangential cyclone with the low-concentration exhaust gas, and an air nozzle is provided in the exhaust pipe. Alternatively, by adopting a configuration in which the motor drive fan is arranged, the purified gas flow after passing through the tangential cyclone is sucked at a higher speed, and the pressure loss in the exhaust gas purification device is further improved, contributing to the improvement of fuel consumption. *

In the present invention device, when the tubular collection part is arranged substantially horizontally, the tubular collection part is substantially constant with respect to the floor of the engine room where the engine is installed. When the maintenance work for the discharge electrode or the like is good, and when the tubular collecting part is arranged substantially vertically and upward with respect to the floor surface, the tubular collecting part is connected to the exhaust pipe to the chimney. Space can be saved, and when the tubular collection part is arranged substantially vertically and downward with respect to the floor surface, the falling PM is not only easily collected, but also captured. When SOF or sulfate adhering to the collecting wall liquefies, the liquid component easily flows down the collecting wall and collects even if heavy oxide scale corroded by the sulfate peels off from the wall and falls. The advantage of being easy to do, etc. It is.

It is a schematic longitudinal cross-sectional view which shows the whole structure of the 1st Example apparatus of this invention. It is a schematic longitudinal cross-sectional view which shows the whole structure of the 2nd Example apparatus of this invention. It is a schematic longitudinal cross-sectional view which expands and shows the principal part of the 3rd Example apparatus of this invention. It is a schematic longitudinal cross-sectional view which expands and shows the principal part of the modification of the 3rd Example apparatus of this invention. It is a schematic longitudinal cross-sectional view which expands and shows the principal part of the 4th Example apparatus of this invention. FIG. 6 is an enlarged cross-sectional view along the line aa in FIG. 5. It is a schematic longitudinal cross-sectional view which abbreviate | omits and shows a part of whole structure of the 5th Example apparatus of this invention. It is explanatory drawing which shows typically the other Example of the cyclone collection means in this invention apparatus. FIG. 4 is an explanatory diagram schematically showing an enlarged speed-up suction portion of the purified gas after passing through a tangential cyclone in the apparatus of the present invention, where (a) shows an air nozzle system and (b) shows a motor-driven fan system. It is the schematic which shows the example which has arrange | positioned the tubular collection part in this invention apparatus substantially perpendicularly and downward. It is the schematic which shows the example which has arrange | positioned the tubular collection part in this invention apparatus substantially perpendicularly and upwards. It is a schematic longitudinal cross-sectional view which shows an example of the conventional diesel engine exhaust gas processing apparatus. It is a schematic longitudinal cross-sectional view which shows the other example of the conventional diesel engine exhaust gas processing apparatus. It is a schematic longitudinal cross-sectional view which shows another example of the conventional diesel engine exhaust gas processing apparatus. It is a schematic longitudinal cross-sectional view which shows another example of the conventional diesel engine exhaust gas processing apparatus. It is a general | schematic longitudinal cross-sectional view which shows another example of the conventional diesel engine exhaust gas processing apparatus partially fractured | ruptured. It is a partial expanded sectional view of the diesel engine exhaust gas processing apparatus shown in FIG.

The diesel engine exhaust gas treatment apparatus shown as the first embodiment of the present invention in FIG. 1 is roughly divided into a tubular collection part 1 constituting an electric dust collection means and a separate collection part 2 constituting a separate collection means. The tubular collecting portion 1 provided for collecting PM particles is included in the exhaust gas and the collecting tube 1-1 having a collecting wall 1-1k having a predetermined length constituting the dust collecting electrode. And a discharge electrode 1-2 for charging the PM. The collection pipe 1-1 constituting the dust collection electrode has an exhaust gas introduction port 1-1a at the end on the upstream side (diesel engine side), and a low concentration of PM in the vicinity of the axial center at the end on the downstream side. The exhaust gas outlet pipe 3 is provided with a PM high-concentration exhaust gas outlet section 1-1b in the vicinity of the inner peripheral surface of the downstream end. The discharge electrode 1-2 is disposed at a desired interval in the longitudinal direction of the main electrode 1-2a extending substantially over the entire length around the axial center of the collection tube 1-1 constituting the dust collection electrode. And a group of radially protruding electrode needles 1-2b. The discharge electrode 1-2 configured in this manner is provided at the inlet portion of the seal air introduction pipe portion 1-1c provided on the exhaust gas introduction port 1-1a side of the collection pipe 1-1 and the low concentration exhaust gas outlet pipe 3. Both ends of the main electrode 1-2a are supported through a support body 4 suspended from the provided seal air introduction pipe section 3-1. Although not shown, the discharge electrode 1-2 is supported at a desired interval by a stay insulated from the inside of the collection tube 1-1 as necessary. Further, the discharge electrode 1-2 is supplied with a controlled high voltage power source by being wired to a high voltage power source device (not shown) installed outside.

The fraction collection part 2 provided on the downstream side of the tubular collection part 1 in the flow direction of the exhaust gas is composed of a cyclone collection means 2-1 as a separation means. The cyclone collecting means 2-1 is composed of a single tangential cyclone 2-1a connected to the high concentration exhaust gas deriving portion 1-1b of the collection pipe 1-1 through a communication pipe 5-1. Further, between the tangential cyclone 2-1a and the low concentration exhaust gas outlet pipe 3, the purified gas after passing through the tangential cyclone 2-1a is joined to the low concentration exhaust gas flowing in the low concentration exhaust gas outlet pipe 3. A discharge pipe 6-1 is provided. The low-concentration exhaust gas outlet pipe 3 is provided with a flow control damper 7 for adjusting the flow rate of the high-concentration exhaust gas flow rate and flow rate into the tangential cyclone 2-1a and the low-concentration exhaust gas discharge rate.
In addition, the chain line part of FIG. 1 illustrates the combination of the main machine 12 and the auxiliary machine 13 in a marine diesel engine. In the case of this marine diesel engine, the engine operation includes parallel operation of the main machine 12 and the auxiliary machine 13 and independent operation of each, and the load of each engine also fluctuates greatly, so that the total exhaust gas flow varies greatly. In the case of a large displacement engine, a plurality of the collecting pipes 1-1 may be provided side by side (not shown).

The diesel engine exhaust gas treatment apparatus shown as the second embodiment apparatus of the present invention in FIG. 2 is the first embodiment apparatus except that the cyclone collecting means 2-1 is composed of two tangential cyclones 2-1a. It has the same configuration as. That is, two tangential cyclones 2-1a are connected in parallel to the high concentration exhaust gas outlet section 1-1b of the collection pipe 1-1 via the communication pipes 5-1, 5-2, and the cyclone collecting means. 2-1 and also in this case, the exhaust pipes 6-1, 6- for joining the purified gas after passing through each tangential cyclone 2-1a to the low concentration exhaust gas flowing in the low concentration exhaust gas outlet pipe 3 respectively. 2 is disposed.

In the diesel engine exhaust gas treatment apparatus shown in FIGS. 1 and 2, PM in the exhaust gas flowing into the collection pipe 1-1 from the exhaust gas introduction port 1-1a is the collection pipe 1- 1 constituting the dust collection electrode. 1 is charged by the discharge between the collection wall surface 1-1k, which is the inner wall of 1, and the discharge electrode 1-2, the charged PM particles are collected on the collection wall surface 1-1k by Coulomb force. The PM particles collected on the collecting wall 1-1k of the collecting tube 1-1 are further accumulated with the accumulation of PM particles collected from the exhaust gas flow near the shaft with the passage of time, and gradually grow to form a lump. This PM mass flows while being concentrated in the vicinity of the collecting wall surface while repeatedly adhering to the tubular collecting wall surface 1-1k by the Coulomb force due to separation and discharge (charging) due to the exhaust flow. At the same time, the PM in the exhaust gas flowing in the vicinity of the axial center of the collection pipe 1-1 is collected on the collection wall 1-1k and gradually diluted to a low concentration. However, it becomes an exhaust gas flow containing only PM and flows downstream. That is, the exhaust gas flowing into the collection pipe 1-1 from the exhaust gas introduction port 1-1a is separated into a high-concentration exhaust gas stream and a low-concentration exhaust gas stream in the process of flowing down the tubular collection section 1, and the collection pipe 1-1 High-concentration exhaust gas flows in the vicinity of the collection wall 1-1k on the inner wall, and the low-concentration exhaust gas flows in the vicinity of the axial center of the collection tube 1-1 and flows downstream of the collection tube 1-1. To go. In the case of the diesel engine exhaust gas treatment apparatus shown in FIG. 1, a high-concentration exhaust gas flow of PM flowing in the vicinity of the collection wall 1-1k of the inner wall of the collection pipe 1-1 downstream of the collection pipe 1-1. Is introduced into the tangential cyclone 2-1a through the communication pipe 5-1 from the high-concentration exhaust gas outlet 1-1b of the collection pipe 1-1, and the PM is centrifuged, and the diesel engine exhaust gas shown in FIG. In the case of the treatment apparatus, the high-concentration exhaust gas flow that flows in the vicinity of the collection wall surface 1-1k of the inner wall of the collection tube 1-1 communicates with the communication pipe from the high-concentration exhaust gas outlet portion 1-1b of the collection tube 1-1. The PM is introduced into two tangential cyclones 2-1a through 5-1 and 5-2 and centrifuged. On the other hand, the low-concentration exhaust gas flow of PM flowing in the vicinity of the axial center of the collection pipe 1-1 is almost in the vicinity of the axial center of the collection pipe 1-1 together with the diesel engine exhaust gas treatment apparatus shown in FIGS. Is discharged to the outside through the low-concentration exhaust gas outlet pipe 3. The exhaust gas flow purified by the tangential cyclone 2-1a is joined to the low-concentration exhaust gas flow flowing in the low-concentration exhaust gas discharge pipe 3 through the exhaust pipes 6-1, 6-1 and 6-2, respectively. The
In the case of the diesel engine exhaust gas treatment apparatus shown in FIG. 2 in which the cyclone collecting means 2-1 is constituted by two tangential cyclones 2-1a, the high concentration exhaust gas discharged from the high concentration exhaust gas deriving unit 1-1b. The number of units to be used may be set according to the flow rate of the flow, and two tangential cyclones 2-1a may be used alternately.

As described above, in the case of the diesel engine exhaust gas treatment apparatus of the present invention shown in FIGS. 1 and 2, only the high concentration exhaust gas of PM (a part of the total exhaust gas amount) can be guided to the cyclone. PM can be collected and separated and collected efficiently.

Next, the diesel engine exhaust gas treatment apparatus shown as the third embodiment apparatus in FIG. 3 is expanded in a taper shape at the downstream end of the collection pipe 1-1 constituting the dust collection electrode of the tubular collection section 1. A tapered tubular portion 1-1d and a large-diameter tubular portion 1-1e connected to the tapered tubular portion, and the low-concentration exhaust gas outlet tube 3 and the vicinity of the inner peripheral surface are formed in the vicinity of the axial center of the large-diameter tubular portion 1-1e. 1 except that the high concentration exhaust gas deriving unit 1-1b is connected to the diesel engine exhaust gas processing apparatus shown in FIG. 1 or FIG. In the case of the diesel engine exhaust gas treatment apparatus having such a configuration, the high-concentration exhaust gas flow is gradually decelerated by the tapered tubular part 1-1d at the downstream end of the collection pipe 1-1, and the large-diameter tubular part 1-1e PM can be reliably introduced into the high concentration exhaust gas deriving portion 1-1b provided in the vicinity of the peripheral surface. It is more preferable that the electrode needle 1-2b of the discharge electrode 1-2 is continuously provided up to the tapered tubular portion 1-1b at the downstream end of the collection tube 1-1.

In the diesel engine exhaust gas treatment apparatus shown in FIG. 3, when the collecting pipe 1-1 is vertically arranged as shown in FIG. 4, the bottom wall surface 1-1e of the large-diameter tubular portion 1-1e is provided. ′ Is inclined downward toward the communication pipe 5-1 as illustrated. This means is used to make liquid components such as SOF and sulfate fall down to the cyclone side easier to collect, and the collection wall 1-1k on the inner surface of the collection tube 1-1 is made of PM, sulfate, etc. This is to make it easy to collect the oxide scale peeled off from the collection wall surface 1-1k when an oxide scale (metal oxide scale or the like) is generated due to corrosion due to corrosion.

In addition, the diesel engine exhaust gas treatment apparatus shown as the fourth embodiment apparatus in FIGS. 5 and 6 is tapered at the downstream end of the collection pipe 1-1 constituting the dust collection electrode of the tubular collection section 1. A diameter-expanding tapered tubular portion 1-1d and a large-diameter tubular portion 1-1e connected to the tapered tubular portion are formed, and a low-concentration exhaust gas outlet tube 3 and an inner periphery are formed in the vicinity of the axial center of the large-diameter tubular portion 1-1e. A high-concentration exhaust gas deriving portion 1-1b is connected in the vicinity of the surface, and further, the discharge electrode 1-2 and the region of the tapered tubular portion 1-1d and the large-diameter tubular portion 1-1e connected to the tapered tubular portion are provided. Except for the configuration in which the electrode needle 1-2b is extended, it has the same configuration as the diesel engine exhaust gas treatment apparatus shown in FIG. 1 or FIG. In the figure, reference numeral 1-2c denotes a support ring for supporting each of the discharge electrodes 1-2 branched into a plurality.
In the case of a diesel engine exhaust gas treatment apparatus having such a configuration, the PM is captured more effectively because the high-concentration exhaust gas flow is gradually decelerated by the tapered tubular part 1-1d at the downstream end of the collection pipe 1-1. In addition to being able to collect, the PM mass grows even after flowing into the large-diameter tubular portion 1-1e, and the collection efficiency of the cyclone collecting means 2-1 is further increased to further purify the exhaust gas. Can measure.

Further, the diesel engine exhaust gas treatment apparatus shown as the fifth embodiment in FIG. 7 has an exhaust gas introduction chamber 1-1f before the collection pipe 1-1, and the exhaust gas introduction chamber 1-1f and the collection pipe 1- 1 is provided with a constricted portion 1-1g and a tapered enlarged diameter portion 1-1h, and an electrode needle 1-2b is also provided in the constricted portion 1-1g and the tapered enlarged diameter portion 1-1h. The exhaust gas introduction port 1-1a to 1-1f and the seal air introduction port 1-1j to the seal air introduction chamber 1-1i are provided to face each other.
In the diesel engine exhaust gas treatment apparatus having such a configuration, when the length of the collection tube 1-1 is L and the inner diameter of the collection tube 1-1 is D, 3D ≦ L ≦ 15D, preferably 5D ≦ L ≦ 10D. It is preferable to satisfy the conditions. The reason is that if the flow is less than 3D, the flow of exhaust gas cannot be rectified and the turbulence cannot be suppressed, so the concentration of PM at the collecting wall 1-1k portion is not promoted. This is because the size of the apparatus is increased and the space efficiency is deteriorated. In addition, 5D ≦ L ≦ 10D as a preferable condition is that if 5D or more, the flow is rectified particularly well, and the concentration of PM near the collecting wall 1-1k is stable, and the concentration is within 10D. This is because the size of the apparatus can be suppressed and the increase in size of the apparatus can be suppressed. Specific examples of the dimensions of each part are as follows. The length L of the collecting tube 1-1 is 3 m, the inner diameter of the collecting tube 1-1 is 400 mm, the length of the restricting portion 1-1 g is 375 mm, The inner diameter of the part 1-1g is φ220 mm, and the taper angle θ of the taper enlarged part 1-1h is 30 degrees.
Further, the exhaust gas that has flowed into the exhaust gas introduction chamber 1-1f from the exhaust gas introduction port 1-1a passes through the throttle portion 1-1g, thereby suppressing the disturbance of the exhaust gas flow through the taper enlarged portion 1-1h. The flow is quickly stabilized and the concentration of the inner wall of the collecting tube at the collecting wall 1-1k and the dilution near the collecting tube axis are promoted. In addition, since the distance between the electrode and the particle is short in the constricted portion 1-1g, all particles can be reliably charged, and the particles adhere to the collecting wall surface 1-1k of the inner wall of the collecting tube to improve the collecting performance. Is peeled off. Note that the exhaust gas is made to flow into the exhaust gas introduction chamber 1-1f so that the exhaust gas flow is balanced and the exhaust gas flow is disturbed by flowing into the collecting pipe 1-1 symmetrically. This is because the flow is reduced and quickly rectified, and is well rectified while having a short axial length. Further, it is also preferable that the seal air with respect to the electrode is made to face and flow into the seal air introduction chamber 1-1i.

Next, the cyclone collecting means shown in FIG. 8 includes a plurality of tangential cyclones having different throughputs, for example, a small throughput tangential cyclone 2-1b, a medium throughput tangential cyclone 2-1c, and a large throughput tangential cyclone. This is composed of three types of cyclones 2-1d, and is connected to the high concentration exhaust gas deriving section 1-1b of the collecting pipe 1-1 through communication pipes 8-1, 8-2, 8-3 connected in radial positions. The tangential cyclones 2-1b, 2-1c and 2-1d are connected to each other, and flow control dampers 9-1 and 9 are connected to the high concentration exhaust gas introduction ports of the communication pipes 8-1, 8-2 and 8-3. -2 and 9-3.
In this way, when the cyclone collecting means is configured with multiple tangential cyclones with different processing capacities, it depends on the change in operating conditions and the load factor of the engine due to the parallel operation and independent operation of the main engine and auxiliary equipment in the marine engine. In addition to being able to select and use each tangential cyclone more appropriately in response to the exhaust gas flow rate that changes, the tangential cyclone combined with the damper disposed in the low concentration exhaust gas outlet pipe 3 By controlling the flow control dampers 9-1, 9-2, and 9-3 provided, it is possible to more appropriately control the tangential speed of the exhaust gas flowing into each tangential cyclone, and the high collection efficiency is wide. It can be secured and maintained in the range of the load factor.

Further, as shown in FIGS. 9 (a) and 9 (b), the purified gas after passing through the tangential cyclone is connected to a discharge pipe 6-1 arranged to join the purified gas after passing through the tangential cyclone with the low-concentration exhaust gas. By installing the air nozzle 10 for speeding up suction or the fan 11 driven by the motor 11-1, kinetic energy is given to the purified gas flow after passing through the tangential cyclone and the speed up suction is performed. It is improved so that the pressure loss in the exhaust gas purifying apparatus is also reduced, and the fuel consumption can be improved.

Further, FIGS. 10 and 11 respectively show a tubular collecting portion 1 in the apparatus of the present invention, for example, 1-1e that expands in a tapered shape at the downstream end of the collecting tube 1-1 shown in FIGS. FIG. 10 shows an example in which the tubular collecting part 1 is arranged substantially perpendicular to the engine room floor, FIG. 10 shows an example in which the tubular collecting part 1 is arranged substantially vertically and downward, and FIG. 11 shows the tubular collecting part. An example in which the collecting unit 1 is arranged substantially vertically and upward is shown. Here, as shown in FIG. 10, when the tubular collection part 1 is arranged substantially vertically and downward, the tubular collection part 1 can also serve as an exhaust pipe piping to a chimney (not shown). Therefore, there is an advantage that space saving can be taken. On the other hand, when the tubular collecting portion 1 is arranged vertically and upward as shown in FIG. 11, not only the falling PM is easily collected, but also SOF, sulfate, etc. adhering to the collecting wall surface are liquefied. In this case, there is an advantage that the liquid component easily flows down the collecting wall surface and is easily collected even if a heavy oxide scale corroded by sulfate or the like peels off from the wall surface and falls. In addition, when the tubular collection part 1 is arrange | positioned substantially horizontal, since the tubular collection part 1 becomes substantially constant height with respect to the floor surface of the engine room in which the engine is installed, a collection tube, a discharge electrode, etc. There is an advantage that workability during maintenance is good.

The diesel engine exhaust gas purification apparatus according to the present invention is a system for purifying exhaust gas by introducing a partial flow of the total exhaust gas amount that has been pre-concentrated and highly concentrated to the cyclone, so that the cyclone can be reduced in size. In addition, the cyclone collecting means is composed of a plurality of tangential cyclones, and a high concentration exhaust gas flow of PM discharged from the high concentration exhaust gas outlet is selectively introduced into the tangential cyclone according to the flow rate of the exhaust gas. As a result, in addition to the effects of a tangential cyclone with better collection performance than an axial flow type cyclone, the change in operating conditions and the load factor of the engine due to the parallel operation and independent operation of the main engine and auxiliary equipment in a marine engine Appropriate selection can be made while balancing the processing capacity and the number of tangential cyclones in response to large fluctuations in the exhaust gas flow rate (velocity) due to fluctuations. Therefore, it is possible to secure and maintain a high PM collection rate corresponding to each change in the exhaust gas flow rate, and to control the opening degree of the damper disposed in the low concentration exhaust gas outlet pipe, thereby the tangential cyclone. The tangential speed of the exhaust gas flowing into the exhaust gas can be controlled appropriately, so that a high PM collection rate can be secured and maintained, and problems such as deterioration in fuel consumption due to excessive pressure loss in the exhaust gas purification device can be solved. Since it has many excellent effects, it contributes greatly to the purification treatment of diesel engine exhaust gas using low quality fuel of heavy oil or less for various uses such as marine, vehicle and industrial use.

DESCRIPTION OF SYMBOLS 1 Tubular collection part 1-1 Collection pipe 1-1a Exhaust gas inlet 1-1b High concentration exhaust gas outlet part 1-1c Seal air introduction pipe part 1-1d Taper tubular part 1-1e Large diameter tubular part 1-1f Exhaust gas Introducing chamber 1-1g Restricted portion 1-1h Tapered diameter expanding portion 1-1i Seal air introducing chamber 1-1j Seal air introducing port 1-1k Collection wall surface 1-2 Discharge electrode 1-2a Main electrode 1-2b Electrode needle 1 -2c Support ring 2 Separation collection unit 2-1 Cyclone collection means 2-1a Tangential cyclone 2-1b Small throughput tangential cyclone 2-1c Medium throughput tangential cyclone 2-1d Large throughput tangential cyclone 3 Low concentration exhaust gas outlet pipe 3-1 Seal air introduction pipe 4 Support body 5-1, 5-2, 8-1, 8-2, 8-3 Communication pipe 6-1, 6-2 Discharge pipe 7, 9- 1, 9-2, 9-3 Flow rate Please damper 10 air nozzle 11 fan 11-1 motor 12 main engine 13 auxiliary

Claims

A discharge electrode for charging particulate matter contained in the exhaust gas of a diesel engine using heavy oil or lower quality fuel, and a tubular collecting portion of a predetermined length constituting a dust collecting electrode for collecting the charged particulate matter And the discharge electrode is an electric current collector constituted by a main electrode disposed in the tubular axial direction in the tubular collecting portion and a plurality of radially projecting electrode needles spaced from the main electrode. In a diesel engine exhaust gas treatment apparatus having a dust collecting means and a cyclone type separation collecting means for separating and collecting the particulate matter separated from the tubular collecting section, in the vicinity of the shaft center on the downstream side of the tubular collecting section A low concentration exhaust gas outlet pipe for particulate matter, a high concentration exhaust gas outlet portion provided in the vicinity of the inner peripheral surface on the downstream side of the tubular collection portion, respectively, and a cyclone for collecting the particulate matter in the high concentration exhaust gas outlet portion for particulate matter Collector And the cyclone collecting means is constituted by a tangential cyclone, and the exhaust gas inflow rate to the tangential cyclone is controlled by controlling the opening degree of the damper disposed in the low concentration exhaust gas outlet pipe. Diesel engine exhaust gas treatment device characterized by its mechanism.
The cyclone collecting means is composed of a plurality of tangential cyclones, and the high concentration exhaust gas discharged from the high concentration exhaust gas deriving section is selectively introduced into the tangential cyclone according to the flow rate of the exhaust gas. The diesel engine exhaust gas treatment apparatus according to claim 1.
The tubular collecting portion has a tapered tubular portion that expands in a tapered shape at a downstream end thereof and a large-diameter tubular portion that continues to the tapered tubular portion, and a low-concentration exhaust gas near the axial center of the large-diameter tubular portion The diesel engine exhaust gas treatment device according to claim 1 or 2, wherein a high-concentration exhaust gas outlet part is provided in the vicinity of the inner peripheral surface of the same large-diameter tubular part as the outlet pipe.
4. The diesel engine exhaust gas treatment according to claim 3, wherein a discharge electrode is extended to a region of a tapered tubular portion of the tubular collecting portion or a large-diameter tubular portion connected to the tapered tubular portion. apparatus.
The diesel engine exhaust gas treatment apparatus according to any one of claims 1 to 4, wherein the tubular collection part is arranged substantially horizontally.
The diesel engine exhaust gas treatment apparatus according to any one of claims 1 to 4, wherein the tubular collection part is arranged substantially vertically and upward.
The diesel engine exhaust gas treatment apparatus according to any one of claims 1 to 4, wherein the tubular collection part is arranged substantially vertically and downward.
The cyclone collecting means is constituted by a plurality of tangential cyclones having different processing capacities, and a flow rate control damper is provided at an inlet of each tangential cyclone. The diesel engine exhaust gas treatment apparatus as described.
Between the tangential cyclone and the low-concentration exhaust gas outlet pipe, a discharge pipe for merging the purified gas after passing the tangential cyclone with the low-concentration exhaust gas is disposed, and an air nozzle or a motor drive is provided in the exhaust pipe. The diesel engine exhaust gas treatment device according to any one of claims 1 to 8, wherein a fan is arranged.