JP2014163365A - Recirculated exhaust gas purification device and purifying recirculated exhaust gas purification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recirculated exhaust gas purification device and a recirculated exhaust gas purification method capable of reducing turbidity and polycyclic aromatic hydrocarbon (PAHs) in exhaust water in an exhaust gas purification treatment.SOLUTION: A recirculated exhaust gas purification device includes first collecting means 72 disposed in an exhaust gas recirculation line Lfor recirculating an exhaust gas 12 discharged from a diesel engine 11 and including a metallic collection filter 71 for collecting fine particles in the exhaust gas 12, second collecting means 74 disposed at a wake flow side of the first collecting means 72 and including active carbon 73 for purifying the exhaust gas 12, a venturi 51 disposed at a wake flow side of the second collecting means 74, and removing the fine particles in the exhaust gas, an exhaust gas scrubber 52 to which the exhaust gas 12 passing through the venturi 51 is introduced to purify the exhaust gas by circulating an absorbent 60, and an active carbon manufacturing device 76 manufacturing the active carbon 73 by using collected components 75 collected by the first collecting means 72. The active carbon 73 obtained by the active carbon manufacturing device 76 is used in the second collecting means 74.

Description

  The present invention relates to a recirculation exhaust gas purification device and a recirculation exhaust gas purification method.

  For example, in a turbocharger that is driven to rotate by exhaust gas from an internal combustion engine such as a marine diesel engine, soot (carbon) is likely to accumulate in portions exposed to combustion gases such as moving blades and stationary blades.

Further, marine diesel engine exhaust gas is an emission control substance in combustion exhaust gas according to IMO (International Maritime Organization) regulations, such as nitrogen oxide (NOx), sulfur oxide (SOx), PM (particulate matter), etc. It is necessary to remove the components.
In particular, PM and SOx are removed by a purification device such as an exhaust gas scrubber provided with spraying means for spraying water or seawater droplets.

  There is an engine system in which the purified exhaust gas purified by the exhaust gas scrubber is introduced into the intake port side of the engine via a compressor of a supercharger and burned again (Patent Document 1).

The exhaust gas scrubber used here is a venturi tube provided on the upstream side of the exhaust gas scrubber to remove PM in the exhaust gas, and sprays an alkaline cleaning liquid “absorbing liquid” such as sodium hydroxide with a spraying means. , SOx is absorbed and removed.
In addition, collection means, such as a mist separator, is installed at the scrubber outlet to finally collect and remove the mist accompanying the exhaust gas.

JP2012-180814A Japanese Patent Laid-Open No. 3-264736

  However, in the exhaust gas from the ship's internal combustion engine using poor fuel containing sulfur (S) content, unburned soot, polycyclic aromatic hydrocarbons (PAHs) incorporated therein, and unburned fuel components When hydrocarbon (HC) is purified by passing through the exhaust gas scrubber, it moves to the absorbent side. In such a case, if the absorbing liquid is discharged directly to the open ocean, there is a problem that turbidity due to soot and fine particles and polycyclic aromatic hydrocarbons (PAHs) increase, which hinders stable navigation.

In addition, even if the apportionment is collected and collected by a filter or the like, it becomes an object of industrial waste as it is, and its storage during navigation becomes a problem.
As a result, when purifying exhaust gas using an exhaust gas scrubber, establishment of a cleaning / removal technology system for reducing turbidity in discharged water and reducing the turbidity is desired.

  In view of such circumstances, the present invention provides a recirculation exhaust gas purification device and a recirculation exhaust gas purification method that reduce turbidity and polycyclic aromatic hydrocarbons (PAHs) in exhaust water in exhaust gas purification treatment. Let it be an issue.

  The first invention of the present invention for solving the above-mentioned problem is an exhaust gas purification apparatus for purifying the exhaust gas when the exhaust gas discharged from the internal combustion engine is recirculated using a supercharger. A first collecting means provided in a waste gas recirculation line for recirculating the exhaust gas discharged from the internal combustion engine, and comprising a metal collecting filter for collecting particulates in the exhaust gas; and the first collecting means. A second collecting means provided with activated carbon for purifying exhaust gas, installed on the downstream side of the exhaust gas, a venturi installed on the downstream side of the second collecting means for removing particulates in the exhaust gas, and An exhaust gas scrubber that introduces exhaust gas after passing through the venturi and purifies the exhaust gas with a circulating absorption liquid, and an activated carbon production apparatus that produces activated carbon using the collected components collected by the first collection means, Equipped with the activated carbon production equipment Certain was activated carbon recirculated exhaust gas purification device is characterized by using in the second trapping means.

  According to a second aspect of the present invention, in the first aspect of the invention, there is provided a recirculation exhaust gas purification apparatus having a third collecting means in a discharge water line for discharging discharge water from the exhaust gas scrubber.

  According to a third aspect of the present invention, there is provided a recirculation exhaust gas purifying apparatus according to the first aspect, wherein the first collection means and the second collection means are provided in two systems.

  According to a fourth invention, in any one of the first to third inventions, the exhaust gas scrubber introduces an exhaust gas after passing through the venturi, and a gas flow in the first purification tower. Heating means provided on the downstream side, a second purification tower communicating with a side wall opening of the first purification tower from which exhaust gas that has passed through the heating means of the first purification tower is discharged, and the second purification tower And a spraying means for spraying the absorbing liquid provided on the downstream side of the gas flow of the tower.

  The fifth invention uses the recirculated exhaust gas purification apparatus according to any one of the first to third aspects, uses the activated carbon obtained by the activated carbon production apparatus as the second collection means, and reduces soot in the exhaust gas. And a recirculation exhaust gas purification method characterized by cleaning with an exhaust gas scrubber.

  The sixth invention is characterized by using the fourth recirculation exhaust gas purification device, bringing bubbles entrained in the exhaust gas after passing through the venturi into contact with the heating means to break up bubbles, and removing the entrained bubbles in the exhaust gas. It is in the recirculation exhaust gas purification method.

  According to a seventh aspect, in the sixth aspect, the fine particles in the foam and the unburned fuel contained in the soot are transferred into the exhaust gas by the foam breakage and introduced into the internal combustion engine side together with the recirculated exhaust gas. The present invention is a recirculation exhaust gas purification method.

  According to the present invention, the first collection means and the second collection means are provided on the front stage side of the exhaust gas scrubber, thereby purifying the exhaust gas and collecting the soot, PM, and the like in the exhaust gas in the first collection. Collected by means. Then, the obtained collection component is separately regenerated into activated carbon by an activated carbon production apparatus, and the regenerated activated carbon is reused by the second collection means, whereby exhaust gas can be purified efficiently.

FIG. 1 is a schematic diagram of a recirculation exhaust gas purification apparatus according to a first embodiment. FIG. 2 is a production process diagram in the activated carbon production apparatus. FIG. 3 is a schematic view of the recirculation exhaust gas purifying apparatus according to the first embodiment. FIG. 4 is a schematic diagram of the recirculation exhaust gas purification apparatus according to the second embodiment. FIG. 5 is a schematic view of heating means in the first purification tower. FIG. 6 is a schematic view of heating means in another first purification tower.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

FIG. 1 is a schematic diagram of a recirculation exhaust gas purification apparatus according to a first embodiment. FIG. 2 is a production process diagram in the activated carbon production apparatus. FIG. 3 is a schematic diagram illustrating an internal combustion engine including the recirculation exhaust gas purifying apparatus according to the first embodiment.
As shown in FIG.1 and FIG.3, when the recirculation exhaust gas purification apparatus 50 which concerns on a present Example recirculates the exhaust gas 12 discharged | emitted from the diesel engine 11 which is an internal combustion engine using the supercharger 13, is the exhaust gas purifying apparatus for purifying the exhaust gas 12 is interposed in the exhaust gas recirculation line L ₃ recirculating flue gas 12 discharged from the diesel engine 11, a metal collection filter for collecting particulates in exhaust gas 12 A first collecting means 72 provided with 71, a second collecting means 74 provided on the downstream side of the first collecting means 72 and provided with activated carbon 73 for purifying the exhaust gas 12, and a second collecting means 74 A venturi 51 installed on the downstream side of the collecting means 74 for removing fine particles in the exhaust gas 12 and the exhaust gas 12 after passing through the venturi 51 are introduced, and the exhaust gas 12 is purified by the circulating absorption liquid 60. The scrubber 52 and an activated carbon production device 76 for producing activated carbon 73 using the collected component 75 collected by the first collection means 72 are provided, and the activated carbon 73 obtained by the activated carbon production device 76 is the first The second collecting means 74 is used.

In the present embodiment, the exhaust gas 12 introduced into the exhaust gas scrubber 52 is purified by removing the collection component 75 such as soot from the exhaust gas 12 by the first collection means 72 and the second collection means 74. Therefore, it is possible to prevent turbidity components such as soot from being mixed into the absorbing liquid 60 circulated in the exhaust gas scrubber 52, and to prevent the turbidity from increasing.
Moreover, the collection component 75 can produce the activated carbon 73 by the activated carbon production apparatus 76 provided therewith, and can reuse this as the activated carbon 73 of the second collection means 74.

Here, an internal combustion engine provided with the exhaust gas purifying apparatus of the present embodiment will be described.
FIG. 3 shows, for example, a diesel engine 11 provided with a recirculation exhaust gas purification device 50 in a ship and used as a main engine for ship propulsion, and an exhaust turbo type supercharger 13 driven by exhaust gas 12 of the diesel engine 11. It has.

The diesel engine 11 is, for example, a marine two-cycle engine, and a uniflow type that is scavenged in one direction so as to supply air from below and exhaust upward is adopted. The output from the diesel engine 11 is directly or indirectly connected to the screw propeller via a propeller shaft (not shown). The exhaust port of the cylinder part 11a (only one cylinder is shown in FIG. 3) of each cylinder of the diesel engine 11 is connected to an exhaust manifold 11b as an exhaust gas collecting pipe. Exhaust manifold 11b via the exhaust gas line L _1, and is connected to the inlet side of the turbine portion 13a of the supercharger 13. In FIG. 1, reference numeral 11c is an exhaust valve, and reference numeral 11d is a piston.

Meanwhile, the scavenging ports of the cylinder portion 11a is connected to the scavenging trunk 11f, scavenging trunk 11f is scavenging line via the (combustion air supply path) L _5, it is connected to the compressor section 13c of the supercharger 13 ing. Further, an air cooler (intercooler) 11 g is installed in the scavenging line L ₅ .

  The supercharger 13 includes a turbine unit 13a and a compressor unit 13c, and the turbine unit 13a and the compressor unit 13c are coaxially connected by a rotating shaft 13b. The turbine part 13a is driven by the exhaust gas 12 from the diesel engine 11, and the turbine work obtained in the turbine part 13a is transmitted to the compressor part 13c via the rotating shaft 13b. The compressor unit 13 c sucks the purified exhaust gas 12 that is the recirculated exhaust gas guided from the outside air (air) 17 and the exhaust gas purification device 15 and raises the pressure to a predetermined scavenging pressure.

Flue gas 12 after giving turbine work at turbine unit 13a flows out to the second exhaust gas line L _2. The exhaust gas 12 passes through the second exhaust gas line L ₂ and is discharged from a chimney (not shown) to the atmosphere.
The second exhaust gas line L ₂ is provided with an exhaust gas recirculation line L ₃ that performs exhaust gas recirculation (EGR) that branches a part of the exhaust gas 12 and returns it to the diesel engine 11 side. The exhaust gas recirculation line L ₃ connects the branch point 28 of the second exhaust gas line L ₂ and the inlet of the exhaust gas scrubber 52. An exhaust gas recirculation adjustment valve 29 for adjusting the exhaust gas circulation amount is provided downstream of the branch point 28 of the exhaust gas recirculation line L ₃ .

  The turbine part 13a is composed of a turbine disk and a turbine blade that receive the exhaust gas 12 and rotates, and is covered with a turbine casing 14a. The turbine casing 14a has a turbine casing inlet through which the exhaust gas 12 is guided from an exhaust gas collecting pipe (not shown), and a turbine casing outlet that guides the exhaust gas that has passed through the turbine blades to the outside of the turbine.

  The compressor unit 13 c includes a compressor casing 14 b and an impeller that compresses the air 17 and the purified exhaust gas 16 by being driven to rotate. The compressor casing 14b is provided so as to cover the impeller. The compressor casing 14b has a compressor casing inlet (suction port) that takes in air from the outside via a silencer, and a compressor casing outlet that discharges air compressed by the impeller.

One end of the rotating shaft 13b is connected to the turbine disk of the turbine section 13a, and the other end is connected to the impeller of the compressor section 13c. Therefore, when the turbine disk is rotationally driven, the impeller is also rotationally driven and the air 17 can be compressed.
The compression purge gas 18 which is compressed through the intercooler 19 interposed scavenging line L _5, is supplied to the scavenging trunk 11f side of the engine 11.

Here, the first and second collection means 72 and 74 interposed in the exhaust gas recirculation line L ₃ will be described.

As shown in FIG. 1, the first collection means 72 is provided with a metal collection filter 71 that collects soot in the exhaust gas 12. Collecting.
In this embodiment, as shown in FIG. 1, two systems of first collecting means 72, 72 are used, and the on-off valves V ₁ , V ₂ , V ₃ , V ₄ provided before and after are alternately opened / closed. By doing so, the exhaust gas 12 is allowed to pass through one of the systems.
In addition, two systems of second collection means 74 and 74 are provided, and the on-off valves V ₅ , V ₆ , V ₇ , and V ₈ provided before and after the two systems are alternately opened and closed, so that either system has an exhaust gas. 12 is passed.

Here, in the exhaust gas 12, soot, ash, polycyclic aromatic hydrocarbons (PAHs), hydrocarbons (HC) as unburned fuel components, sulfur oxides (SOx), nitrogen oxides (NOx), etc. It is included.
Polycyclic aromatic hydrocarbons (PAHs) are, for example, naphthalene, phenanthrene, pyrene, benzopyrene, and the like, which together with hydrocarbons (HC) and soot, are raw materials for activated carbon 73.

  Therefore, in this embodiment, using these collected components (soot, polycyclic aromatic hydrocarbons (PAHs), hydrocarbons (HC) which are unburned fuel components) 75, an activated carbon production apparatus 76 is used. Thus, the activated carbon 73 is manufactured.

Next, the manufacturing process of activated carbon is demonstrated using FIG.
As shown in FIG. 2, the collection components 75 such as soot collected by the metal collection filter 72 of the first collection means 72 are collected (recovery step (S1)).
In the molding machine, the recovered material is molded into a pellet having a diameter of, for example, about 8 to 10 mm (pellet molding step (S2)).
In a firing furnace, activation treatment is performed at 700 to 1,000 ° C. and regeneration (activation step (S3)).
By these steps, activated carbon 73 having pores of about 10 to 500 mm is obtained.

  The obtained activated carbon 73 can be reused by replacing it with the activated carbon 73 broken through by the second collection means 74 (reuse step (S4)).

Further, the activated carbon broken through by the second collecting means 74 may be activated and regenerated and reused.
The activated carbon that has stopped functioning is then landed and then incinerated separately.

  Thereby, since the exhaust gas 12 introduced into the exhaust gas scrubber 52 is purified, it is possible to prevent soot from being mixed into the absorption liquid 60 and to prevent an increase in the turbidity of the absorption liquid 60.

  In particular, when seawater is used as the absorbing liquid 60, in the case of a sea area with high turbidity in seawater, if it is circulated and used in the exhaust gas scrubber 52, the increase in turbidity becomes significant. By purifying the exhaust gas with the first and second collection means 72 and 74, an increase in turbidity can be suppressed.

  In addition, regarding the polycyclic aromatic hydrocarbons (PAHs) contained in the exhaust gas 12, if there is a discharge standard for the discharged water 80, the concentration of the polycyclic aromatic hydrocarbons (PAHs) can be reduced, and the wastewater regulation Can be achieved to achieve stable navigation.

  Moreover, the activated carbon 73 used for the second collection means 74 can produce activated carbon from the collected component 75 collected by the first collection means 72 by an activated carbon production apparatus 76 installed in the ship. 73 can be reused.

  As drainage standards, 16 components other than naphthalene are defined for polycyclic aromatic hydrocarbons (PAHs), and a standard is provided for discharged water 80 such as absorption liquid discharged from the exhaust gas scrubber 52. In some cases, by applying the present invention, drainage regulations can be cleared and stable navigation can be achieved.

  Since the exhaust gas 12 is purified by the adsorption treatment of the activated carbon 73 by the second collection means 74, the sulfur oxides that have been adsorbed and collected such as soot and PM in the exhaust gas 12 are collected, and the inside of the exhaust gas scrubber 52. It is also possible to reduce the concentration of sulfur oxide introduced into the. Thereby, the fall of pH of the discharged water 80 can also be suppressed.

  In the recirculation exhaust gas purification device 50, after the soot and the like in the exhaust gas 12 is purified by the first collection means 72 and the second collection means 74, PM is further added by the venturi 51 installed on the upstream side of the exhaust gas scrubber 52. And so on. The venturi 51 is supplied with makeup water 79 to remove the remaining PM and soot in the exhaust gas 12.

  Here, the exhaust gas scrubber 52 includes a spray means 56 for spraying an absorbing liquid (water or seawater) 60 provided in the scrubber body, a packed bed 64 in which the introduced exhaust gas 12 and the absorbing liquid 60 are in contact with each other, and a main body. And a mist separator 57 provided on the outlet side. The absorbing liquid 60 is circulated by a pump 62 interposed in a circulation line 61 and is cooled by a cooling means 63.

  In the exhaust gas scrubber 52, the exhaust gas 12 that has passed through the venturi 51 is introduced, and the PM and the like in the exhaust gas 12 are removed by the sprayed absorbent 60, and NOx and SOx are absorbed and removed.

  Further, the exhaust gas 12 purified by spraying the absorbing liquid 60 finally collects and removes the mist accompanying the exhaust gas 12 by a collecting means such as a mist separator 57 provided at the scrubber outlet.

  Further, an exhaust gas cooler may be installed on the upper end side of the exhaust gas scrubber 52.

The drainage line 81 is provided with drainage monitoring means 84 to monitor the discharged water 80 to be discharged.
The discharged water 80 discharged from the exhaust gas scrubber 52 is purified by passing through an activated carbon tank 82 installed in the discharge line 81.

  In addition, some of the return lines 85 are also provided with activated carbon, and when the drainage monitoring means 84 exceeds the reference value, the activated carbon tank 82 is used for purification, and the circulation pump 62 uses it again as the absorbent 60. Is done.

  As described above, by providing the first collecting means 72 and the second collecting means 74 on the front stage side of the exhaust gas scrubber 52, the exhaust gas 12 is purified and the soot, PM, etc. in the exhaust gas 12 are removed from the first stage. It is collected by the collecting means 72. Then, the obtained collection component 75 is separately regenerated into activated carbon 73 by the activated carbon production apparatus 76, and the activated carbon 73 is reused by the second collection means 74, whereby the exhaust gas can be purified efficiently. it can.

  The purified exhaust gas 16 that has passed through the exhaust gas scrubber 52 is guided to the mixing chamber 31. The mixing chamber 31 is provided on the upstream side of the compressor unit 13 c of the supercharger 13, and the purified exhaust gas 16 guided from the exhaust gas scrubber 52 and the outside air 17 are mixed.

Next, the operation method of the marine diesel engine 11 provided with the recirculation exhaust gas purification device will be described.
Flue gas 12 discharged from the diesel engine 11 is guided to the turbine portion 13a of the supercharger 13 via a first exhaust gas line L ₁ from the exhaust manifold 11b. In the turbine part 13a, exhaust gas energy is obtained and rotated, and the compressor part 13c is rotated. In the compressor unit 13c, the sucked air (outside air) 17 and the recirculated purified exhaust gas 16 are compressed and sent to the scavenging trunk 11f of the diesel engine 11 through the air cooler 11g.

For example, when navigating a sea area where exhaust gas NOx regulations are strict, exhaust gas recirculation is performed so that the exhaust gas has a predetermined NOx value or less. In this case, the exhaust gas recirculation regulating valve 29 is opened and set to a predetermined opening according to a command from a control unit (not shown).
By opening the adjustment valve 29 for exhaust gas recirculation, a predetermined amount of the exhaust gas 12 is branched from the second exhaust gas line L ₂ , passes through the exhaust gas recirculation line L _3, and passes through the first collection means 72 and the second collection device. It passes through the collecting means 74 and is led to the exhaust gas scrubber 52.

  By providing the first collection means 72 and the second collection means 74 on the front side of the exhaust gas scrubber 52, the exhaust gas 12 is purified and soot, PM, etc. in the exhaust gas 12 are collected.

  Then, the collected component 75 is regenerated into activated carbon 73 by an activated carbon production apparatus 76 installed separately, and the activated carbon 73 is reused by the second collection means 74.

  The exhaust gas scrubber 52 removes PM by the venturi 51 and makes the gas-liquid contact with the exhaust gas 12 by spraying the absorbing liquid 60 from above with the spraying means 56 to absorb and remove PM and SOx in the exhaust gas 12. To do.

The purified exhaust gas 16 processed by the exhaust gas scrubber 52 passes through the purified exhaust gas line L ₄ , and is thereafter guided to the mixing chamber 31. In the mixing chamber 31, the purified exhaust gas 16 and the outside air 17 are mixed and guided to the compressor unit 13 c of the supercharger 13. The compressed and purified gas 18 of the mixed fluid compressed by the compressor unit 13c is led to the scavenging trunk 11f after being cooled by the air cooler 11g.

As described above, by providing the first collecting means 72 and the second collecting means 74 on the front stage side of the exhaust gas scrubber 52, the exhaust gas 12 is purified and soot, PM, etc. in the exhaust gas 12 are collected. The collected component 75 is regenerated to the activated carbon 73 by the activated carbon manufacturing apparatus 76 separately. Then, by reusing the regenerated activated carbon 73 by the second collecting means 74, the exhaust gas can be purified efficiently.
Thus, stable navigation is possible while clearing the standard of the discharged water 80 discharged from the exhaust gas scrubber 52.

Next, the recirculation exhaust gas purification apparatus according to the present embodiment will be described with reference to FIG.
FIG. 4 is a schematic diagram of the recirculation exhaust gas purification apparatus according to the second embodiment. FIG. 5 is a schematic view of heating means in the first purification tower. FIG. 6 is a schematic view of heating means in another first purification tower. In addition, the same code | symbol is attached | subjected to the member which overlaps with the structure of the recirculation exhaust gas purification apparatus which concerns on Example 1 of FIG.1, 3, and the description is abbreviate | omitted. Note that the first collecting means 72 and the second collecting means 74 are omitted.
As shown in FIG. 4, in the recirculation exhaust gas purification apparatus according to the present embodiment, in the recirculation exhaust gas purification apparatus of the first embodiment, the exhaust gas scrubber 52 further introduces the exhaust gas 12 after passing through the venturi 51. The first purification tower 54A, the heating means 53 provided on the downstream side of the gas flow in the first purification tower 54A, and the first exhaust gas that has passed through the heating means 53 of the first purification tower 54A is discharged. The second purification tower 54B communicating with the side wall opening 52a of the purification tower 54A, the spray means 56 for spraying the absorbing liquid 55 provided on the downstream side of the gas flow in the second purification tower 54B, and the spray means 56 Mist collecting means 57 provided on the downstream side of the gas flow.

In this embodiment, by installing the heating means 53 in the first purification tower 54A, the bubbles 78 in the exhaust gas 12 are broken by contacting with the heating means 53, and are accompanied by the exhaust gas 12 to the downstream side. To prevent it from flowing. Thereby, it can prevent conveying from the exhaust gas scrubber 52 to the supercharger 13 of the downstream side, and can prevent the performance deterioration of the supercharger 13 and damage trouble.
First, as shown in FIG. 4, makeup water 70 is introduced into the venturi 51 installed on the upstream side of the exhaust gas scrubber 52 and a part of the absorbing liquid 60 collected at the bottom of the first purification tower 54A is introduced. It has been introduced.

And by introducing the exhaust gas 12 having a flow rate of 40 to 100 m / s into the venturi 51, particles such as PM and soot are transferred from the gas side to the circulating water side.
At the time of this removal, since the exhaust gas 12 is at a high speed, a large amount of bubbles 78 are generated and accompanied by the exhaust gas and introduced into the first purification tower 54A.

The bubbles 78 generated here are light bubbles having a bulk density of 0.05 to 0.1 g / Cm ³ , and these light bubbles stay and accumulate on the surface of the absorbing liquid 60 and are carried to the gas flow of the exhaust gas 12. It will be accompanied and scattered downstream.

In the present embodiment, the heating means 53 is provided on the gas flow downstream side (the top side of the first purification tower 54A) of the exhaust gas 12 of the first purification tower 54A. The heating means 53 uses the heat of the high temperature exhaust gas 12. Then, a part before being introduced into the venturi 51 is branched and introduced by the branch line L ₁₁ , and after passing through the heating means 53, is returned to the venturi 51 again.

  The circulating absorption liquid 60 is cooled by the cooling water 63a of the cooler 63 from the bottom of the first purification tower 54A by the circulation pump 62 interposed in the circulation line 61, and is supplied to the spray means 56. To the inside of the second purification tower 54B.

  Then, in the exhaust gas scrubber 52, the exhaust gas 12 that has passed through the venturi 51 is introduced into the first purification tower 54A, and when rising, it comes into contact with the heating means (about 200 ° C.) 53, so that the bubbles in the exhaust gas 12 are removed. Let bubbles break. Then, the broken foam is dropped into the absorption liquid reservoir 52b at the bottom of the first purification tower 54A.

  Next, the exhaust gas 12 from which the bubbles have been removed is introduced into the second purification tower 54B that communicates with the side wall opening 52a of the first purification tower 54A, and PM in the exhaust gas is removed by the absorbing liquid 60 that is sprayed. , NOx and SOx are absorbed and removed.

The exhaust gas 12 purified by spraying the absorbing liquid 60 is finally collected and removed by the mist accompanying the exhaust gas 12 by a mist collecting means 57 such as a mist separator provided at the scrubber outlet. Is introduced into the purified exhaust gas line L ₄ .

  Further, an exhaust gas cooler may be installed on the upper end side of the exhaust gas scrubber 52.

Here, since the soot which is a foam breaking substance is porous, it contains unburned fuel.
Therefore, by causing the foam 78 to break, the soot contained in the foam 78 touches the outside air, and the unburned fuel contained in the soot is transferred into the exhaust gas. Then, after passing through the exhaust gas scrubber 52 and compressed in the supercharger 13 together with engine combustion air and supplied to the internal combustion engine, the unburned fuel can be burned.
That is, in the case of discharging to the outside as discharged water in the form of bubbles, unburned fuel is discharged to the open ocean, but this can be prevented and reused by breaking the bubbles.

As a heating means installed in the first purification tower 54A, a meandering tube may be installed as shown in FIG.
Here, the diameter D of the tube may be, for example, 10 mm to 20 mm, and the interval d between the tubes may be, for example, about 20 mm to 30 mm.

  Moreover, you may make it install a spiral tube as shown in FIG.

  By introducing the exhaust gas 12 into the inside of the tube, bubbles in the exhaust gas 12 passing between the tubes (for example, d: 20 mm to 30 mm) are brought into contact with each other to break the bubbles. The shape of the tube is not limited to these.

As described above, by installing the heating means 53 in the first purification tower 54A, bubbles in the exhaust gas are broken by coming into contact with the heating means and are prevented from flowing to the downstream side accompanying the exhaust gas. .
Thereby, it can prevent conveying from the exhaust gas scrubber 52 to the supercharger 13 of the downstream side, and can prevent performance degradation and damage trouble of the supercharger. PM and soot contained in the foam fall into the cleaning liquid, are collected in the cleaning means, and can be discharged to the outside.

  As described above, since the bubbles generated in the venturi 51 installed on the upstream side of the exhaust gas scrubber 52 are removed, it is prevented from being conveyed to the supercharger 13 installed on the downstream side, and the performance of the turbocharger is reduced. And damage troubles can be prevented.

DESCRIPTION OF SYMBOLS 11 Diesel engine 12 Exhaust gas 13 Supercharger 13a Turbine part 13c Compressor part 16 Purified exhaust gas 17 Air 18 Compressed purification gas 50 Recirculation exhaust gas purification apparatus 51 Venturi 52 Exhaust gas scrubber 53 Heating means 54A 1st purification tower 54B 2nd purification tower DESCRIPTION OF SYMBOLS 56 Spraying means 57 Mist collection means 60 Absorbing liquid 71 Metal collection filter 72 1st collection means 73 Activated carbon 74 2nd collection means 75 Collection component 76 Activated carbon production apparatus

Claims (7)

When exhaust gas discharged from an internal combustion engine is recirculated using a supercharger, the exhaust gas purification device purifies the exhaust gas,
A first collecting means provided with a metal collecting filter that is interposed in an exhaust gas recirculation line for recirculating exhaust gas discharged from the internal combustion engine and collects particulates in the exhaust gas;
A second collecting means installed on the downstream side of the first collecting means and provided with activated carbon for purifying exhaust gas;
A venturi installed on the downstream side of the second collection means to remove particulates in the exhaust gas;
An exhaust gas scrubber that introduces exhaust gas after passing through the venturi and purifies the exhaust gas with a circulating absorbent;
An activated carbon production apparatus for producing activated carbon using the collected components collected by the first collection means,
A recirculated exhaust gas purification apparatus using the activated carbon obtained by the activated carbon production apparatus in the second collecting means. In claim 1,
A recirculation exhaust gas purification apparatus comprising a third collection means in an exhaust water line for discharging exhaust water from the exhaust gas scrubber. In claim 1,
The recirculation exhaust gas purification apparatus characterized in that the first collection means and the second collection means are in two systems. In any one of Claims 1 thru | or 3,
The exhaust gas scrubber is
A first purification tower for introducing exhaust gas after passing through the venturi;
Heating means provided on the downstream side of the gas flow in the first purification tower;
A second purification tower communicating with a side wall opening of the first purification tower from which exhaust gas that has passed through the heating means of the first purification tower is discharged;
A recirculation exhaust gas purification apparatus comprising spray means for spraying an absorbing liquid provided on the gas flow downstream side of the second purification tower. Using the recirculation exhaust gas purification device according to any one of claims 1 to 3,
A recirculated exhaust gas purification method characterized in that the activated carbon obtained by the activated carbon production apparatus is used in the second collecting means to reduce soot in the exhaust gas, and then washed with an exhaust gas scrubber. Using the recirculation exhaust gas purification device of claim 4,
A recirculating exhaust gas purification method, wherein bubbles entrained in exhaust gas after passing through a venturi are brought into contact with heating means to break the bubbles, thereby removing the entrained bubbles in the exhaust gas. In claim 6,
A recirculated exhaust gas purification method, wherein fine particles in bubbles and unburned fuel contained in soot are transferred into exhaust gas by foam breakage and introduced to the internal combustion engine side together with the recirculated exhaust gas.

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