Title of Invention

EXHAUST GAS PURIFIER

Abstract The present invention provides an exhaust gas purifier capable of appropriately purifying harmful components discharged even from an internal combustion engine or a combustion instrument operated mainly in excess air conditions. Particularly, the exhaust gas purifier is capable of appropriately removing nitrogen oxides, particulate matters including soot, etc. amd in addition, capable of maintaining its purification capability without reduction, the exhaust gas purifier has, in the exhaust passage (2) of an internal combustion engine (l), a nitrogen oxide adsorbent (4) for temporarily adsorbing nitrogen oxides and desorbing the adsorbed nitrogen oxides in a temperature increased enviroment or a reducing envioment, an adsorbed substance desorbing means (3) being disposed on an exhaust gas upstream side of the nitrogen oxide adsorbent (4), the adsorbed substance desorbing means (3) heating the exhaust gas or air or converting the exhaust gas or air into a reducing atmosphere, a combustion apparatus (5) being disposed on an exhaust gas downstream side of the nitrogen oxide adsorbent (4), the combustion apparatus (4) including air supply means (15), fuel supply means (6), and ignition means (7); and a filter apparatus (40) being disposed on an exhaust gas downstream side of the combustion apparatus (5) to be able to capture a particulate substance contained in the exhaust gas.
Full Text TECHNICAL FIELD
The present invention relates to an apparatus for purifying exhaust
gas of an internal combustion engine such as a diesel engine, a gas engine, a
gasoline engine, and a gas turbine engine or a combustion device such as an
incinerator and a boiler. More particularly, the present invention relates to
an exhaust gas purifier installed within an exhaust gas passage and mainly
removing nitrogen oxide and the like.
BACKGROUND ART
A target substance subject to exhaust gas purification is a
particulate matter such as nitrogen oxide, carbon monoxide, unburned
hydrocarbon, soot and the like. Various apparatuses for purifying these
substances have been conventionally developed.
As an apparatus for reducing the nitrogen oxide (NOx), a denitration
apparatus or the like has come into practical use, in which a reduction
catalyst using an ammonia or an urea as a reducing agent is installed in an
exhaust passage, thereby selectively reducing the nitrogen oxide. Further,
in a comparatively compact gas engine or an automotive gasoline engine,
there has been developed a three-way catalyst which can simultaneously
decompose three elements comprising the nitrogen oxide, the carbon
monoxide (CO) and the unburned hydrocarbon (HO, and the three way
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catalyst contributes to an effective purification of the exhaust gas.
However, it has been known that the three-way catalyst effectively
achieves a purifying operation in the case that the three-way catalyst is
operated at a theoretical air fuel ratio or within close thereto, but is
not effectively operated under the other conditions, particularly in exhaust
gas in which air (oxygen) is excess. In order to cope with this, in the gas or
gasoline engine operated in the excess air state, a nitrogen oxide occluding
catalyst system has come into practical use, which temporarily occludes the
nitrogen oxide in an occluding agent at a time of being operated under the
excess air (oxygen) condition, and next discharges and reduces the occluded
nitrogen oxide by being operated under the excess fuel condition.
However, there has been known that in the nitrogen oxide occluding
catalyst system, the catalyst is poisoned by sulfur oxide (SOx) in the
exhaust gas derived from a sulfur component in a fuel, and a purifying
capacity of the nitrogen oxide is rapidly reduced, and the nitrogen oxide
occluding catalyst system is used only in the engine using a low sulfur
containing fuel in an actual condition. There has been developed a purifier
(Patent Document 1) having a structure which reduces nitrogen oxide
adsorbed to the occluding substance and discharging the sulfur oxide or the
like, by occluding the nitrogen oxide using the occluding substance in a
nitrogen oxide purifying tower and burning the nitrogen oxide in the
nitrogen oxide purifying tower. However, because the structure is made
such as to burn within the purifying tower having the occluding substance
built-in, a durability of the occluding substance becomes actually
problematic.
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For removing a particulate substance such as the soot, an electric
precipitator and a DPF come into practical use. The DPF is structured
such as to capture the particulate substance by a filter, and burns and
removes the captured particulate substance by an electric heater or the like.
There has been recently developed a DPF in which a catalyst component
having an oxidizing operation is carried in a fine particle filter, and the
particulate substance can be continuously removed.
Patent Document l: Japanese Patent Publication Laid~Open No.
2008-27927
DISCLOSURE OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
The three-way catalyst cannot exert a catalyst function in the
internal combustion engine or the combution instrumrnt equipment
operated under the excessive air condition, as has been already explained.
Further, in the nitrogen oxide occluding catalyst system coming into
practical use in a compact gas engine or an automotive gasoline engine, it is
difficult to effectively achieve the purifying capacity in the exhaust gas
containing the sulfur oxide or the particulate substance.
In the industrial internal combustion engine, the combustion
instrument and a marine internal combustion engine, most of them are
operated under the excessive air condition, and the fuel containing the
sulfur component is used. Accordingly, a lot of sulfur oxide and particulate
substance are contained in the exhaust gas, and there is a need of an
exhaust gas purifier which can sufficiently achieves a performance under
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the exhaust gas mentioned above.
Note that the denitration apparatus selectively reducing the
nitrogen oxide by using ammonia, urea, and the like is applied to a
relatively large industrial internal combustion engine or combustion
instrument. However, the apparatus itself is large and extremely
expensive, and a maintenance cost of the the reducing agent such as
ammonia and urea is also increased. Further, there is a great possibility
that the unconsumed ammonia is discharged in the atmospheric air.
(Object of the Invention)
An object of the invention is to provide an exhaust gas purifier which
can properly remove exhausted harmful components even in internal
combustion engine or combustion instrument mainly operated under the
excess air condition.
Particularly, the object of the invention is to be able to properly
remove the nitrogen oxide, the particulate substance such as the soot, the
carbon monoxide, and the unburned hydrocarbon in the exhaust gas to
maintain a purifying capacity of the exhaust gas purifier without lowering
the purifying capacity, or to be able to properly remove the nitrogen oxide,
the sulfur oxide, and the like in the exhaust gas to maintain a purifying
capacity of the exhaust gas purifier without lowering the purifying capacity
even in the fuel containing the sulfur component.
A first aspect according to the invention provides an exhaust gas
purifier which is displaced in an exhaust passage of an internal combustion
engine or a combustion instrument, the exhaust gas purifier characterized
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by including a nitrogen oxide adsorbent which temporarily adsorbs nitrogen
oxide and desorbs the adsorbed nitrogen oxide by heating or reducing
atmosphere; adsorbed substance desorbing means which is disposed on an
exhaust gas upstream side of the nitrogen oxide adsorbent, the adsorbed
substance desorbing means heating the exhaust gas or air or converting the
exhaust gas or air into a reducing atmosphere; a combustion apparatus
which is disposed on an exhaust gas downstream side of the nitrogen oxide
adsorbent, the combustion apparatus including air supply means, fuel
supply means, and ignition means! and a filter apparatus which is disposed
on an exhaust gas downstream side of the combustion apparatus to be able
to capture a particulate substance contained in the exhaust gas, wherein the
nitrogen oxide adsorbent, the adsorbed substance desorbing means, the
combustion apparatus, and the filter apparatus are provided in the exhaust
passage.
According to the first aspect of the invention, following
working-effects are obtained.
During the normal operation of the internal combustion engine or
the like, the adsorbed substance desorbing means and the combustion
apparatus are stopped, and the nitrogen oxide in the exhaust gas is
adsorbed to and removed by the nitrogen oxide adsorbent and the
particulate substance contained in the exhaust gas is captured by the filter
apparatus in the exhaust passage.
When the adsorbing amount of the nitrogen oxide adsorbent or the
capturing amount of the filter apparatus reaches a predetermined amount
(for example, saturated amount), the adsorbed substance desorbing means
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and the combustion apparatus are operated to perform the regenerating
operation. In the nitrogen oxide adsorbent, the adsorbed nitrogen oxide is
desorbed by the adsorbed substance desorbing means. The desorbed
nitrogen oxide is delivered to the combustion apparatus, and then
appropriately reduced and removed by the combustion apparatus. In the
filter apparatus, the captured particulate substance is burned and removed
by combustion means.
At this point, usually the nitrogen oxide adsorbent differs from the
filter apparatus in the saturated amount and the regenerating conditions
such as a time and a temperature. Accordingly, in the present invention,
both the adsorbed substance desorbing means and the combustion
apparatus are operated, for example, the regeneration of the nitrogen oxide
adsorbent and the regeneration of the filter apparatus are simultaneously
performed according to the regenerating conditions of the nitrogen oxide
adsorbent, and the adsorbed substance desorbing means can be stopped
while only the combustion means is operated to regenerate the filter
apparatus in the case where the filter apparatus is insufficiently
regenerated due to the difference in regenerating conditions between the
nitrogen oxide adsorbent and the filter apparatus or the like. At this point,
the particulate substance can be removed efficiently and substantially
completely by operating the combustion apparatus according to the
regenerating conditions of the filter apparatus. Accordingly, the nitrogen
oxide adsorbent and the filter apparatus are appropriately regenerated and
maintained without decreasing the purifying ability. In addition, the fuel
cost is also saved.
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In the exhaust gas purifier according to the first aspect of the
invention, a second aspect, of the invention is characterized in that the
exhaust passage is branched into a plurality of branch exhaust passages,
means for being able to block gas flow is provided in an exhaust gas
inlet of each branch exhaust passage, each branch exhaust passage includes
the nitrogen oxide adsorbent, the adsorbed substance desorbing the
combustion apparatus, and the filter apparatus, and the adsorbed substance
desorbing means includes air supply means and is configured to heat air
from the air supply means or to convert the air into the reducing
atmosphere.
According to the second aspect of the invention, the exhaust
caused to flow into at least one branch exhaust passage from the internal
combustion engine or the like, and the exhaust gas can be blocked in other
branch exhaust passages to perform the regenerating operation. The
exhaust gas is blocked in the branch exhaust passage in which the
regenerating operation is performed, so that the air amount can freely set
irrespective of the exhaust gas amount in the adsorbed substance desorbing
means and the air supply means of each combustion apparatus.
Accordingly, the air amount of the branch exhaust gas passage in a
regenerating operation state can be set less independently of the branch
exhaust gas passage in a normal operation state, the energy (the fuel flow
rate) consumed for desorbing the nitrogen oxide from the nitrogen oxide
adsorbent and the fuel flow rate supplied to the combustion apparatus can.
be set less, and saving of the fuel cost can be achieved,
A third aspect according to the invention provides an exhaust gas
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purifier which is displaced in an exhaust passage of an internal combustion
engine or a combustion instrument, the exhaust gas purifier characterized
in that the exhaust passage branch exhaust passage is branched into a
plurality of branch exhaust passages, blocking means for being able to block
gas flow are provided at an exhaust gas inlet and an exhaust gas outlet of
the branch exhaust passage, a nitrogen oxide adsorbent, an adsorbed
substance desorbing means, a combustion apparatus, a filter apparatus, and
an atmospheric air releasing portion are provided between the blocking
means at the exhaust gas inlet and exhaust gas outlet of the branch exhaust
passage, the nitrogen oxide adsorbent temporarily adsorbing nitrogen oxide
and desorbing the adsorbed nitrogen oxide by heating or reducing
atmosphere, the adsorbed substance desorbing means being disposed on an
exhaust gas downstream side of the nitrogen oxide adsorbent, the adsorbed
substance desorbing means including air supply means while heating air
from the air supply means or converting the air into a reducing atmosphere,
the combustion apparatus being disposed on an exhaust gas upstream side
of the nitrogen oxide adsorbent, the combustion apparatus including air
supply means, fuel supply means, and ignition means, the filter apparatus
being disposed on an exhaust gas upstream side of the combustion
apparatus to be able to capture a particulate substance contained in the
exhaust gas, the atmospheric air releasing portion being disposed on an
exhaust gas upstream side of the filter apparatus to open the branch
exhaust passage to an atmosphere, and when the adsorbed substance
desorbing means and the combustion apparatus are operated to perform a
regenerating operation, the exhaust gas inlet and exhaust gas outlet, of the
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branch exhaust passage are blocked by the blocking means, the branch
exhaust passage is opened by the atmospheric air releasing portion, and gas
generated by the regenerating operation is caused to flow in a direction
opposite an exhaust gas flowing direction and discharged from the
atmospheric air releasing portion.
According to the third aspect of the invention, following
working-effects are obtained.
During the normal operation of the internal combustion engine or
the like, in the branch exhaust passage in which the exhaust gas flows, the
adsorbed substance desorbing means and the combustion apparatus are
stopped, the particulate substance contained in the exhaust gas is captured
by the filter apparatus, and the nitrogen oxide in the exhaust gas is
adsorbed to and removed by the nitrogen oxide adsorbent. Accordingly, the
nitrogen oxide adsorbent is hardly clogged with the particulate substance,
and a decrease in adsorption of the nitrogen oxide adsorbent can be
prevented.
In the case where the adsorbing amount of the nitrogen oxide
adsorbent or sulfur oxide adsorbent reaches a predetermined amount (for
example, saturated amount), the regenerating operation can be performed
in each adsorbent. During the regenerating operation, the adsorbed
substance desorbing means and the combustion apparatus are operated in
the state in which the exhaust gas inlet and outlet are blocked by the
blocking means while the branch exhaust passage is released to the
atmosphere by the atmospheric air releasing portion. The nitrogen oxide
adsorbed to the nitrogen oxide is desorbed by the adsorbed substance
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desorbing means. The desorbed nitrogen oxide is delivered to the
combustion apparatus, and then reduced and removed in the combustion
apparatus. The particulate substance captured by the filter apparatus is
incinerated and removed by the combustion apparatus. The gas
(regenerated gas) generated by the regenerating operation flows in a
direction opposite to the exhaust gas flow, and the gas is discharged to the
atmosphere through the atmospheric air releasing portion.
As described above, usually the nitrogen oxide adsorbent and the
filter apparatus differ from each other in the saturated amount and the
regenerating conditions. Accordingly, in the present invention, both the
adsorbed substance desorbing means and the combustion apparatus are
operated, for example, the regeneration of the nitrogen oxide adsorbent and
the regeneration of the filter apparatus are simultaneously performed
according to the regenerating conditions of the nitrogen oxide adsorbent,
and the adsorbed substance desorbing means can be stopped while only the
combustion means is operated to regenerate the filter apparatus in the case
where the filter apparatus is insufficiently regenerated due to the difference
in regenerating conditions between the nitrogen oxide adsorbent and the
filter apparatus or the like. At this point, the particulate substance can be
removed efficiently and substantially completely by operating the
combustion apparatus according to the regenerating conditions of the filter
apparatus. Accordingly, the nitrogen oxide adsorbent and the filter
apparatus are appropriately regenerated and maintained without
decreasing the purifying ability. In addition, the fuel cost is also saved.
Because the exhaust passage is branched into the plurality of
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branch exhaust passages, the exhaust gas generated during the normal
operation of the internal combustion engine or the like is caused to flow into
at least one branch exhaust passage, and the exhaust gas can be blocked in
other branch exhaust passages to perform the regenerating operation. The
exhaust gas is blocked in the branch exhaust passage in which the
regenerating operation is performed, so that the air amount can freely set
irrespective of the exhaust gas amount in the adsorbed substance desorbing
means and the air supply means of each combustion apparatus.
Accordingly, the air amount of the branch exhaust gas passage in the
regenerating operation state can be set less independently of the branch
exhaust gas passage in the normal operation state, the energy (the fuel flow
rate) consumed for desorbing the nitrogen oxide from the nitrogen oxide
adsorbent and the fuel flow rate supplied to the combustion apparatus can
be set less, and saving of the fuel cost can be achieved.
A fourth aspect according to the invention provides an exhaust gas
purifier which is displaced in an exhaust passage of an internal combustion
engine or a combustion instrument, the exhaust gas purifier characterized
in that the exhaust passage branch exhaust passage is branched into a
plurality of branch exhaust passages, blocking means for being able to block
gas flow are provided at an exhaust gas inlet and an exhaust gas outlet of
the branch exhaust passage, a nitrogen oxide adsorbent, a sulfur oxide
adsorbent, an adsorbed substance desorbing means, a combustion apparatus,
and an atmospheric air releasing portion are provided between the blocking
means at the exhaust gas inlet and exhaust gas outlet of the branch exhaust
passage, the nitrogen oxide adsorbent temporarily adsorbing nitrogen oxide
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and desorbing the adsorbed nitrogen oxide by heating or reducing
atmosphere, the sulfur oxide adsorbent being disposed on an exhaust gas
upstream side of the nitrogen oxide adsorbent, the sulfur oxide adsorbent
temporarily adsorbing sulfur oxide and desorbing the adsorbed sulfur oxide
by heating or reducing atmosphere, the adsorbed substance desorbing
means being disposed on an exhaust gas downstream side of the nitrogen
oxide adsorbent, the adsorbed substance desorbing means including air
supply meanswhile heating air from the air supply means or converting the
air into a reducing atmosphere, the combustion apparatus being disposed on
an exhaust gas upstream side of the nitrogen oxide adsorbent, the
combustion apparatus including air supply means, fuel supply means, and
ignition means, the atmospheric air releasing portion being disposed on an
exhaust gas upstream side of the filter apparatus to open the branch
exhaust passage to an atmosphere, and when the adsorbed substance
desorbing means and the combustion apparatus are operated to perform a
regenerating operation, the exhaust gas inlet and exhaust gas outlet of the
branch exhaust passage are blocked by the blocking means, the branch
exhaust passage is opened by the atmospheric air releasing portion, and gas
generated by the regenerating operation is caused to flow in a direction
opposite an exhaust gas flowing direction and discharged from the
atmospheric air releasing portion.
According to the fourth aspect of the invention, following
working effects are obtained.
During the normal operation of the internal combustion engine or
the like, the adsorbed substance desorbing means and the combustion
13

apparatus are stopped, and the sulfur oxide in the exhaust gas discharged
from the internal combustion engine or the like is adsorbed to and removed
by the sulfur oxide adsorbent, and the nitrogen oxide is adsorbed to and
removed by the nitrogen oxide adsorbent.
Because the sulfur oxide adsorbent is disposed on the exhaust gas
upstream of the nitrogen oxide adsorbent, the sulfur oxide hardly flows into
the nitrogen oxide adsorbent, and the performance deterioration caused by
the poisoning of the sulfur oxide can be suppressed in the nitrogen oxide
adsorbent.
In the case where the adsorbing amount of the nitrogen oxide
adsorbent or sulfur oxide adsorbent reaches a predetermined amount (for
example, saturated amount), the regenerating operation can be performed
in each adsorbent. During the regenerating operation, the adsorbed
substance desorbing means and the combustion apparatus are operated in
the state in which the exhaust gas inlet and outlet are blocked by the
blocking means while the branch exhaust passage is released to the
atmosphere by the atmospheric air releasing portion. The nitrogen oxide
adsorbed to the nitrogen oxide and the sulfur oxide adsorbed to the sulfur
oxide adsorbent are desorbed respectively by the adsorbed substance
desorbing means. The desorbed nitrogen oxide and sulfur oxide are
delivered to the combustion apparatus, and then reduced and removed in
the combustion apparatus. The gas (regenerated gas) generated by the
regenerating operation flows in the direction opposite to the exhaust gas
flow, and the gas is discharged to the atmosphere through the atmospheric
air releasing portion. Therefore, the sulfur oxide desorbed from the sulfur
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oxide adsorbent does not flow into the nitrogen oxide adsorbent, and the
performance deterioration caused by the poisoning of the sulfur oxide can he
suppressed in the nitrogen oxide adsorbent.
Accordingly, in the present invention, the nitrogen oxide and sulfur
oxide in the exhaust gas can properly be removed even in the fuel containing
the sulfur component, and the performance of the adsorbent can be
maintained without decreasing the purifying ability.
Because the exhaust passage is branched into the plurality of
branch exhaust passages, the exhaust gas generated during the normal
operation of the internal combustion engine or the like is caused to flow into
at least, one branch exhaust passage, and the exhaust gas can be blocked in
other branch exhaust passages to perform the regenerating operation. The
exhaust gas is blocked in the branch exhaust passage in which the
regenerating operation is performed, so that the air amount can freely set
irrespective of the exhaust gas amount in the adsorbed substance desorbing
means and the air supply means of each combustion apparatus.
Accordingly, the air amount of the branch exhaust gas passage in the
regenerating operation state can be set less independently of the branch
exhaust gas passage in the normal operation state, the energy (the fuel flow
rate) consumed for desorbing the nitrogen oxide and sulfur oxide from the
nitrogen oxide adsorbent and sulfur oxide adsorbent and the fuel flow rate
supplied to the combustion region on a downstream side of the adsorbent
can be set less, and saving of the fuel cost can be achieved.
In the exhaust gas purifier according to the fourth aspect of the
invention, a fifth aspect according to the invention is characterized in that,
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in each branch exhaust passage, a filter apparatus which can capture a
particulate substance contained in the exhaust gas is disposed on the
exhaust gas upstream side of the combustion apparatus and on the exhaust
gas downstream side of the atmospheric air releasing portion.
According to the fifth aspect of the invention, during the normal
operation of the internal combustion engine or the like, the particulate
substance contained in the exhaust gas is captured by the filter apparatus,
and the particulate substance does not flow into the nitrogen oxide
adsorbent and the sulfur oxide adsorbent. Accordingly, the particulate
substance has no bad influence on the adsorbing performance of each
adsorbent.
In the case where the adsorbed substance desorbing means and the
combustion apparatus are operated to perform the regenerating operation,
the adsorbed nitrogen oxide and sulfur oxide are desorbed in the nitrogen
oxide adsorbent and the sulfur oxide adsorbent, the desorbed nitrogen oxide
and sulfur oxide are delivered to the combustion apparatus, and the
nitrogen oxide is properly reduced and removed by the combustion
apparatus. In the filter apparatus, the captured particulate substance is
incinerated and removed by the combustion means.
As described above, usually the nitrogen oxide adsorbent and the
sulfur oxide adsorbent differ from the filter apparatus in the saturated
amount and the regenerating conditions. Accordingly, in the invention,
both the adsorbed substance desorbing means and the combustion
apparatus are operated, the regeneration of each adsorbent and the
regeneration of the filter apparatus are simultaneously performed according
16

to the regenerating conditions of each adsorbent, and the adsorbed
substance desorbing means can be stopped while only the combustion means
is operated to regenerate the filter apparatus in the case where the filter
apparatus is insufficiently regenerated due to the difference in regenerating
conditions between each adsorbent and the filter apparatus or the like. At
this point, the particulate substance can efficiently be removed by operating
the combustion apparatus according to the regenerating conditions of the
filter apparatus. Accordingly, each adsorbent and the filter apparatus are
appropriately regenerated and maintained without decreasing the purifying
ability. In addition, the fuel cost is also saved.
EFFECT OF THE INVENTION
According to the invention, even in the internal combustion engine
or combustion instrument which is operated on the excess air condition, the
discharged harmful component can properly be purified.
Particularly, in the first to third aspects of the invention, the
nitrogen oxide in the exhaust gas and the particulate substance such as the
soot can properly bo removed, and the exhaust gas purifier can be
maintained without decreasing the purifying ability.
In the fourth and fifth aspects of the invention, the nitrogen oxide,
the sulfur oxide, and the like in the exhaust gas can properly be removed
even in the fuel containing the sulfur component and the exhaust, gas
purifier can be maintained without, decreasing the purifying ability.
BRIEF DESCRIPTION OF THE DRAWINGS
17

Fig. 1 is a schematic view showing an exhaust gas purifier according
to a first embodiment of the invention.
Pig, 2 is a schematic view showing an exhaust gas purifier according
to a second embodiment of the invention.
Fig. 3 is a schematic view showing an exhaust gas purifier according
to a third embodiment of the invention.
Fig. 4 is a schematic view showing an exhaust gas purifier according
to a fourth embodiment of the invention.
Fig. 5 is a schematic view showing an exhaust gas purifier according
to a fifth embodiment of the invention.
EXPANATrONS OF LETTER OR NUMERALS
1 internal combustion engine
2 exhaust passage
2a branch exhaust passage
2b branch exhaust passage
3 adsorbed substance desorbing means
4 nitrogen oxide adsorbent
5 combustion apparatus
6 fuel nozde (fuel supply means)
7 igniter (ignition means)
15 air supply means
20 upstream-side switching valve
31 fuel nozzle (fuel supply means)
32 igniter (ignition means)
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33 air supply means
40 fine particle filter (filter apparatus)
42 sulfur oxide adsorbent
58 downstream-side switching valve
60 atmospheric air releasing portion
BEST MODES FOR CARRYING OUT THE INVENTION
(First Embodiment)
Fig. 1 is a schematic view showing an exhaust gas purifier according
to a first embodiment of the invention. The first embodiment is mainly
based on the first aspect of the present invention. An exhaust gas purifier
is disposed in a single exhaust passage 2 of the internal combustion engine 1
or a combustion instrument. Examples of the internal combustion engine 1
include a diesel engine, a gas engine, a gasoline engine and a gas turbine
engine. An example of the combustion instrument includes an industrial
boiler and the like.
In the exhaust passage 2, adsorbed substance desorbing means 3, a
nitrogen oxide adsorbent 4 (hereinafter referred to as "NOx adsorbent"), a
combustion apparatus 5, and a filter apparatus 40 axe disposed at
predetermined intervals in an exhaust gas flowing direction Zl in the order
from an exhaust gas upstream side.
The combustion apparatus 5 includes air supply means 15, ignition
means 7, and fuel supply means 6. The fuel supply means 6 includes a fuel
nozzle, and the fuel nozzle 6 is connected to a fuel amount regulating
apparatus 10 through a fuel tank 11. In the fuel supply means 6, a supply
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amount and supply timing of the fuel are controlled by an electronic control
unit 12 (hereinafter referred to as "ECU"). The ignition means 7 is formed
by an igniter.
The air supply means 15 is disposed on an exhaust gas downstream
side of the fuel nozzle 6 and connected to an air supply source 17 through an
air amount regulating apparatus 16. In the air amount regulating
apparatus 16, the supply amount and supply timing of the fuel are
controlled bv the ECU 12.
An NOx adsorbent 4 can efficiently and temporarily adsorb nitrogen
oxide (hereinafter referred to as MNOx") particularly even under an excess
air atmosphere, and has a nature of desorbing the adsorbed NOx at the time
of being heated to a predetermined temperature or under a reducing
atmosphere. In the present embodiment, the NOx adsorbent 4 includes a
catalyst having an oxidation and oxidizes unburned components such as
carbon monoxide (hereinafter referred to as "CO") and hydrocarbon
(hereinafter referred to as "HC").
For example, heating means for heating the exhaust gas to a
predetermined temperature or more is used as the adsorbed substance
desorbing means 3. Means for converting the exhaust gas into a reducing
atmosphere may be used as the adsorbed substance desorbing means 3.
Alternatively, the structure in which reducing agent supply means is added
to the heating means is formed, whereby efficiently the NOx and the SOx
can efficiently be adsorbed and desorbed. A heat generating resister such
as an electric heater is used as the heating means, whereby the temperature
is rapidly and securely raised. Further, a fuel supply means can also be
20

provided as another example of the adsorbed substance desorbing means 3.
In this case, the supplied fuel plays a role as the reducing agent, and the
NOx is desorbed by utilizing the heat generation at the time the supplied
fuel is oxidized on the catalyst contained in the NOx adsorbent 4 and having
the oxidation.
The filter apparatus 40 is formed by a fine particle filter which can
capture the particulate substance included in the exhaust gas. The filter
apparatus 40 may have a function of only capturing the particulate
substance, and may include a catalyst having an oxidizing operation and
have a function of being capable of continuously oxidizing the particulate
substance.
(Working-Effect of First Embodiment)
In the structure shown in Fig, 1, the adsorbed substance desorbing
means {heating means) 3 and the combustion apparatus 5 are stopped
during the normal operation of the internal combustion engine 1.
Accordingly, the exhaust gas discharged from the internal combustion
engine 1 into the exhaust passage 2 directly reaches the NOx adsorbent 4,
and the NOx is adsorbed. At the same time, unburned components such as
the CO and the HC are oxidized and detoxified by the oxidizing catalyst
contained in the NOx adsorbent 4. Then, the particulate substance
included in the exhaust gas is physically captured by the fine particle filter
40, and the purified exhaust gas is discharged from the exhaust passage 2.
In the case where an amount of particulate substance adsorbed to
the fine particle filter 40 becomes saturated and the back pressure is
increased or an adsorbing amount of NOx adsorbent 4 reaches a
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predetermined amount (for example, saturated amount), the adsorbed
substance desorbing means 3 and the combustion apparatus 5 are operated
to regenerate the NOx adsorbent 4 and the fine particle filter 40.
In the adsorbed substance desorbing means 3. the exhaust gas is
heated to a predetermined temperature or more on an upstream side of the
nitrogen oxide adsorbent 4, and the NOx adsorbent 4 is heated to the
predetermined temperature or more, whereby desorbing the NOx adsorbed
to the NOx adsorbent 4.
The NOx desorhed from the NOx adsorbent 4 reaches the
combustion apparatus 5 on the exhaust gas downstream side. The
combustion apparatus 5 causes the igniter 7 to burn the exhaust gas flowing
from the adsorbed substance desorbing means 3 with the fuel supplied from
the fuel nozzle 6, thereby forming an over-rich combustion region XI on the
exhaust gas upstream side of the air supply means 15. In the over-rich
combustion region XI, the NOx desorbed from the NOx adsorbent 4 is
reduced and removed. That is, the NOx is detoxified to N2 and discharged.
The combustion apparatus 5 also forms a lean fuel combustion
region X2 on the exhaust gas downstream side of the air supply means 15 by
the air supplied from the air supply means 15. the CO, the HC, and the
particulate substance which are discharged from the internal combustion
engine 1 and over-rich combustion region XI are burned and removed in the
lean fuel combustion region X2,
The exhaust gas and regenerated gas passing through the
combustion apparatus 5 are always pass through the over-rich combustion
region XI and lean fuel combustion region X2, because the regions XI and
22

X2 are formed across the whole section of the exhaust passage 2.
Accordingly, the NOx is surely reduced and removed, and the CO, the HC,
and the particulate substance which are discharged from the internal
combustion engine 1 and over-rich combustion region XI are surely burned
and removed.
The particulate substance captured by the fine particle filter 40 is
incinerated and removed by the burning of the combustion apparatus 5. At
this point, the NOx adsorbent 4 and the fine particle filter 40 usually differ
from each other in regenerating conditions such as a regenerating time and
a temperature. For example, although an upper limit of the temperature
rise in the NOx adsorbent 4 is restricted due to deterioration caused by heat,
sometimes the fine particle filter 40 can be regenerated at temperatures
higher than the upper limit temperature. The NOx adsorbent 4 and the
fine particle filter 40 differ from each other in a saturated amount.
Accordingly, when the regenerating operation is performed under the
condition in which the NOx adsorbent is regenerated, sometimes the fine
particle filter 40 is insufficiently regenerated even if the NOx adsorbent 4 is
regenerated.
In such the first embodiment, while the adsorbed substance
desorbing means 3 is stopped, only the combustion apparatus 5 can be
operated to regenerate only the fine particle filter 40. Because the single
regenerating operation of the fine particle filter 40 has no heat influence on
the NOx adsorbent 4, the combustion apparatus 5 can be operated at a high
temperature according to the regenerating conditions of the fine particle
filter 40. Accordingly, the particulate substance can efficiently be burned
23

and removed, and the fuel consumption becomes lessened.
In the case where the SOx is contained in the exhaust gas, the SOx
is desorbed from the NOx adsorbent 4 using a material to which the SOx is
hardly adsorbed, or the NOx adsorbent 4 is heated to an SOx desorbing
temperature even if the SOx is adsorbed, and the SOx is desorbed from the
NOx adsorbent 4 using the reducing atmosphere if needed,
(Second Embodiment)
Fig. 2 is a schematic view showing an exhaust gas purifier according
to a second embodiment of the invention. The second embodiment is
mainly based on the second aspect of the invention. In the exhaust gas
purifier of the present embodiment, the exhaust passage 2 is branched into
a plurality of branch exhaust passages 2a and 2b, e.g., first and second
branch exhaust passages 2a and 2b. The two branch exhaust passages 2a
and 2b are merged again on the exhaust gas downstream side and connected
to a downstream-side exhaust passage 2c.
A switching valve 20 is provided in a branch portion on an upstream
side of the two branch exhaust passages 2a and 2b. The exhaust gas from
the internal combustion engine 1 can selectively be discharged to one of the
branch exhaust passages 2a and 2b by switching the switching valve 20.
The switching valve 20 constitutes blocking means for blocking the flow of
the exhaust gas at an exhaust gas inlet of the branch exhaust passages 2a
and 2b.
As with the first embodiment, in each of the branch exhaust
passages 2a and 2b, the adsorbed substance desorbing means3, the NOx
adsorbent 4, the combustion apparatus 5, and the filter apparatus 40 are
24

disposed in the order from the exhaust gas upstream side. The
configurations of the NOx adsorbent 4, combustion apparatus 5, and filter
apparatus 40 are similar to those of the first embodiment.
The adsorbed substance describing means 3 of the second
embodiment includes an air supply means 33 to heat the air from the air
supply means 33 or to change the air into the reducing atmosphere.
Specifically, the adsorbed substance desorbing means 3 includes an
adsorbed substance desorbing apparatus which is formed by the air supply
means 33, a fuel supply means 31, and an ignition means 32. The fuel
supply means 31 includes the fuel nozzle, and is connected to the fuel
amount regulating apparatus 10. The air supply means 33 is connected to
the air amount regulating apparatus 16, and the ignition means 32 is
formed by the igniter.
(Working-Effect of Second Embodiment)
In the case where the internal combustion engine 1 is operated, the
switching valve 20 switches the exhaust gas passages to utilize one of the
branch exhaust passages 2a and 2b as the exhaust gas discharge passage of
the internal combustion engine 1. In the state of Fig. 2, the second branch
exhaust passage 2b is used as the exhaust gas passage, while the first
branch exhaust passage 2a is used for the regenerating operation.
In the state of Fig. 2, in the second branch exhaust passage 2b in the
normal operation state, the combustion apparatus 5 and the adsorbed
substance desorbing means 3 are stopped, the NOx in the exhaust gas is
adsorbed to the NOx adsorbent 4, and the particulate substance is captured
by the fine particle filter 40. On the other hand, in the first branch exhaust
25

passage 2a in the regenerating operation state, the combustion apparatus 5
and the adsorbed substance desorbing means 3 are operated, the adsorbed
substance desorbing means 3 burns the fuel from the fuel nozzle 31 with the
air from the air supply means 33 to supply the high-temperature
regenerated gas to the NOx adsorbent 4, the NOx is desorbed from the NOx
adsorbent 4, and the NOx is reduced ajid removed in the over-rich
combustion region XI of the combustion apparatus 5.
The exhaust gas is blocked from the internal combustion engine 1 in
the first branch exhaust, passage 2a in the regenerating operation state, and
the first branch exhaust passage 2a in the regenerating operation state is
operated independently of the second branch exhaust passage 2b in the
normal operation state, and the regenerating operation is performed by the
fuel and air supplied from the adsorbed substance desorbing means 3 and
combustion apparatus 5 in the first branch exhaust passage 2a. Therefore,
the amount of air used for the adsorbed substance desorption and the
combustion apparatus is properly set irrespective of the exhaust gas amount
from the internal combustion engine lt so that the amount of fuel supplied
from the adsorbed substance desorbing means 3 and the amount of fuel
supplied in the combustion apparatus 5 can be saved.
When the NOx absorbing amount of the NOx adsorbent 4 in the
second branch exhaust passage 2b reaches a predetermined amount (for
example, saturated amount), the switching valve 20 is switched to the first
branch exhaust passage 2a, and the combustion apparatus 5 and adsorbed
substance desorbing means 3 in the second branch exhaust passage 2b are
operated while the combustion apparatus 5 and adsorbed substance
26

desorbing means 3 in the first branch exhaust passage 2a are stopped.
That is, the normal operation is performed in the first branch exhaust
passage 2a, and the regenerating operation is simultaneously performed in
the second branch exhaust passage 2b.
Thus, in the second embodiment, the normal operation of the
internal combustion engine 1 can be performed by utilizing the one branch
exhaust passage while the regenerating operation is performed in the other
passage, thereby eliminating the particular time required
for the regenerating operation.
(Third Embodiment)
Fig. 3 is a schematic view showing an exhaust gas purifier according
to a third embodiment of the invention. The third embodiment is mainly
based on the fourth aspect of the invention. As with the first and second
embodiments, the exhaust gas purifier is provided in the exhaust passage 2
of the internal combustion engine 1 or combustion instrument.
The exhaust passage 2 is branched into a plurality of branch
exhaust passages 2a and 2b. In the third embodiment, the exhaust
passage 2 is branched into the first and second branch exhaust passages 2a
and 2b, and the two branch exhaust passages 2a and 2b are merged again
on the exhaust gas downstream side and connected to the downstream -side
exhaust passage 2c,
An upstream-side switching valve 20 is provided in a branch portion
on the upstream side of the two branch exhaust passages 2a and 2b, and a
downstream-side switching valve 58 is provided in a branch portion on the
downstream side. The exhaust gas from the internal combustion engine 1
27

can selectively be discharged to one of the branch exhaust passages 2a and
2b by switching the upstream-side switching valve 20. The
downstream-side switching valve 58 prevents the exhaust gas from flowing
into the branch exhaust passage 2a through a merging portion while
connecting the branch exhaust passage 2b through which the exhaust gas
flows to the downstream side exhaust passage 2c. The upstream-side
switching valve 20 and the downstream-side switching valve 58 constitute
blocking means for blocking the flow of the exhaust gas or regenerated gas
at the exhaust gas inlet or outlet of the branch exhaust passages 2a and 2b.
In each of the branch exhaust passages 2a and 2b» the adsorbed
substance desorbing means 3, the nitrogen oxide adsorbent 4 (hereinafter
referred to as "HOx adsorbent"), the sulfur oxide adsorbent 42 (hereinafter
referred to as "SOx adsorbent"), and the combustion apparatus 5 are
disposed at intervals in the exhaust gas flowing direction Zl in the order
from the exhaust gas downstream side.
As with the first embodiment, the combustion apparatus 5 includes
the air supply means 15, the ignition means 7, and the fuel supply means 6.
The fuel supply means 6 includes the fuel nozzle, and the fuel nozzle 6 is
connected to the fuel tank 11 through the fuel amount regulating apparatus
10. The supply amount and supply timing of the fuel are controlled by the
electronic control unit 12 (hereinafter referred to as "ECU"). The ignition
means 7 includes the igniter.
The air supply means 15 is disposed on the exhaust gas upstream
side of the fuel nozzle 6 and connected to the air supply source 17 through
the air amount regulating apparatus 16. In the air amount regulating
28

apparatus 16, the supply amount and supply timing of the fuel are
controlled hy the ECU 12.
Particularly the MOx adsorbent 4 can efficiently and tentatively
adsorb the nitrogen oxide (hereinafter referred to as "NOx") even in the
excess air atmosphere, and the NOx adsorbent 4 desorbs the adsorbed NOx
in a predetermined increased temperature or in the reducing atmosphere.
In the present embodiments the NOx adsorbent 4 includes a catalyst having
oxidation, and the NOx adsorbent 4 oxidizes the unburned components such
as the carbon monoxide (hereinafter referred to as "CO") and the
hydrocarbon (hereinafter referred to as "HC"). The NOx adsorbent 4 is
formed in the shape in which the particulate substance is easily captured.
An SOx adsorbent 42 tentatively adsorbs an SOx, and the SOx
adsorbent 42 desorbs the adsorbed SOx in a predetermined increased
temperature or in the reducing atmosphere.
The adsorbed substance desorbing means 3 includes the air supply
means 33 to heat the air from the air supply means 33 or to change the air
into the reducing atmosphere. Specifically, the adsorbed substance
desorbing means 3 includes an adsorbed substance desorbing apparatus
which is formed by the air supply means 33, the fuel supply means 31, and
the ignition means 32. The fuel supply means 31 includes the fuel nozzle,
and the fuel supply means 31 is connected to the fuel amount regulating
apparatus 10. The air supply means 33 is connected to the air amount
regulating apparatus 16, and the ignition means 32 is formed by the igniter.
In each of the branch exhaust 2a and 2b, an atmospheric
air releasing portion 60 is provided on the exhaust gas upstream side of the
29

combustion apparatus 5. The atmospheric air releasing portion 60 includes
an atmospheric air releasing passage 61 connected to the branch exhaust
passage 2a or 2b and an opening and closing valve 62 provided in the
atmospheric air releasing passage 61. Each of the branch exhaust passage
2a and 2b is released into the atmosphere through the atmospheric air
releasing passage 61 by opening the opening and closing valve 62, and each
of the branch exhaust passage 2a and 2b is blocked from the atmosphere by
closing the opening and closing valve 62.
(Working*Effect, of Third Embodiment)
During the normal operation of the internal combustion engine 1,
the exhaust gas is discharged to one of the branch exhaust passage 2a or 2b
selected by the upstream-side switching valve 20 and the downstream-side
switching valve 58. In example of Fig. 3, the exhaust gas is discharged to
the second branch exhaust passage 2b. At this point, the adsorbed
substance desorbing means 3 and combustion apparatus 5 provided in the
second branch exhaust passage 2b are stopped.
The exhaust gas flows into the SOx adsorbent 42, and the SOx
contained in the exhaust gas is adsorbed to the exhaust SOx adsorbent 42.
Then, the exhaust gas flows into the NOx adsorbent 4, NOx contained in the
exhaust gas is adsorbed to the exhaust NOx adsorbent 4, and the exhaust
gas is discharged through the downstream-side switching valve 58 and the
downstream-side exhaust passage 2c. In the NOx adsorbent 4, the
unburned component such as the CO and the HC is oxidized and detoxified
by the oxidizing catalyst, and the particulate substance is physically
captured.
30

On the other hand, in the first branch exhaust passage 2a, the
exhaust gas of the internal combustion engine 1 is blocked, and the
regenerating operation can be performed in the NOx adsorbent 4 and SOx
adsorbent 42 disposed in the first branch exhaust passage 2a while the
normal operation is operated in the internal combustion engine 1.
The adsorbed substance desorbing means 3 and the combustion
apparatus 5 are operated while the opening and closing valve 62 of the
atmospheric air releasing portion 60 is opened, thereby performing the
regenerating operation.
In the adsorbed substance desorbing means 3, the fuel supplied from
the fuel nozzle 31 is burned with the air from the air supply means 33, and
the high-temperature regenerated gas is supplied to the NOx adsorbent 4
and the SOx adsorbent 42. This enables the NOx and the SOx to be
desorbed from the NOx adsorbent 4 and the SOx adsorbent 42.
In the combustion apparatus 5, the fuel supplied from the fuel
nozzle 6 is burned by the igniter 7 using the regenerated gas flowing from
the adsorbed substance desorbing means 3, and the over-rich combustion
region XI is formed on the exhaust gas downstream side of air supply means
15. The NOx desorbed from the NOx adsorbent 4 is reduced and removed
in the over-rich combustion region XI. In the combustion apparatus 5, the
lean fuel combustion region X2 is formed on the exhaust gas upstream side
of the air supply means 15 by the air supplied from the air supply means 15.
The CO, the HC, and the particulate substance which are discharged from
the overrich combustion region XI are burned and removed in the lean fuel
combustion region X2. Then, the regenerated gas is discharged to the
31

atmosphere through the atmospheric air releasing portion 60.
Accordingly, in the regenerating operation, the flow (arrow Z2) of the
regenerated gas is generated in the direction opposite the exhaust gas flow
direction Zl.
In the second branch exhaust passage 2b through which the exhaust
gas of the normal operation flows, in the case where the adsorbed amount of
NOx adsorbent 4 or SOx adsorbent 42 reaches a predetermined amount (for
example, saturated amount), the upstream-side switching valve 20 and the
downstream-side switching valve 58 are switched to discharge the exhaust
gas to the first branch exhaust passage 2a, and the regenerating operation
is similarly performed in the second branch exhaust passage 2b.
During the normal operation, because the SOx contained in the
exhaust gas is adsorbed to the SOx adsorbent 42 before the SOX reaches the
NOx adsorbent 4, the SOx is prevented from poisoning the NOx adsorbent 4.
During the regenerating operation, because the SOx desorbed from the SOx
adsorbent 42 flows onto the combustion apparatus 5 without flowing into
the NOx adsorbent 4, the SOx is prevented from poisoning the NOx
adsorbent 4. That is, in the present embodiment, the exhaust gas flow and
the regenerated gas flow are reversed each other to prevent the SOx from
flowing into the NOx adsorbent 4 in both the normal operation and the
regenerating operation, and the deterioration of performance can be
prevented in the NOx adsorbent 4.
In the combustion apparatus 5, because the over-rich combustion
region XI and the lean fuel combustion region X2 are formed across the
whole sections of the branch exhaust passages 2a and 2b, the regenerated
32

gas passing through the combustion apparatus 5 always passes through the
regions XI and X2. Accordingly, the NOx and the SOx are surely reduced
and removed, and the CO, the HC, and the particulate substance from the
over-rich combustion region XI are surely burned and removed.
The regenerating operations of the NOx adsorbent 4 and SOx
adsorbent 42 are independently performed by the fuel supplies and air
supplies from the adsorbed substance desorbing means 3 and combustion
apparatus 5 in the branch exhaust passage in which the exhaust gas of the
internal combustion engine 1 is blocked. Therefore, the amount of air for
the adsorbed substance desorption and combustion apparatus is set
irrespective of the amount of exhaust gas from the internal combustion
engine 1, so that the amount of fuel supplied from the adsorbed substance
desorbing means 3 and the amount of fuel supplied in the combustion
apparatus can be saved,
In the third embodiment, the normal operation of the internal
combustion engine 1 can be performed by utilizing one of the branch
exhaust passages while the regenerating operation is performed in the other
branch exhaust passage, thereby eliminating the particular time required
for the regenerating operation. Additionally, the switching valves 20 and
58 are used as the blocking means for blocking the exhaust gas inlet and
outlet of the branch exhaust passage, one of the branch exhaust passages is
easily blocked from the exhaust gas, and the exhaust gas can easily be
caused to flow into the other branch exhaust passage at the same time.
(Fourth Embodiment)
Fig. 4 is a schematic view showing an exhaust gas purifier according
33

to a fourth embodiment of the invention. The present embodiment is
mainly based on the fifth aspect of the invention. In the fourth
embodiment, the filter apparatus 40 is provided to the exhaust gas purifier
of the third embodiment to capture the particulate substance contained in
the exhaust gas. The configurations of the fourth embodiment are similar
to those of the third embodiment. The filter apparatus 40 is formed by the
fine particle filter disposed on the exhaust gas upstream side of the
combustion apparatus 5 between the switching valves 20 and 58 in each of
the branch exhaust passages 2a and 2b.
The working of the present embodiment is substantially similar to
that of the third embodiment. However, during the normal operation, the
particulate substance contained in the exhaust gas is captured by the fine
particle filter 40 before the particulate substance lows into the SOx
adsorbent 42 and the NOx adsorbent 4, Accordingly, the SOx adsorbent 42
and the NOx adsorbent 4 are hardly clogged with the particulate substance,
so that the decrease in adsorption of each adsorbent can be prevented.
During the normal operation, when the amount of particulate
substance adsorbed to the fine particle filter 40 becomes the saturated state
to increase the background pressure, or when the amount of adsorbed NOx
or SOx reaches the predetermined amount (for example, saturated amount),
the normal operation is switched to the regenerating operation. During the
regenerating operation, the particulate substance captured by the fine
particle filter 40 is mainly incinerated and removed to regenerate the fine
particle filter 40 by the burning of the combustion apparatus 5.
As described in the first embodiment, the NOx adsorbent 4 and the
34

SOx adsorbent 42 usually differ from the fine particle filter 40 in the
regenerating conditions such as the regenerating time and the temperature
and the saturated amount. For example, although the upper limit of the
temperature rise in the NOx adsorbent 4 is restricted due to deterioration
caused by heat, sometimes the fine particle filter 40 can be regenerated at
temperatures higher than the upper limit temperature. Accordingly, when
the regenerating operation is performed under the conditions of each of the
adsorbents 4 and 42, sometimes the fine particle filter 40 is insufficiently
regenerated even if the regeneration of adsorbent 4 or 42 is regenerated.
In such cases, while the adsorbed substance desorbing means 3 is stopped,
only the combustion apparatus 5 can be operated to regenerate only the fine
particle filter 40. Because the single regenerating operation of the fine
particle filter 40 has no heat influence on the NOx adsorbent 4 and the like,
the combustion apparatus 5 can be op-erated at a high temperature
according to the regenerating conditions of the fine particle filter 40.
Therefore, the particulate substance can be burned and removed efficiently
and substantially completely, and the wasted consumption of the fuel is
eliminated.
The filter apparatus 40 may have a function of only capturing the
particulate substance, and the filter apparatus 40 may include a catalyst
having the oxidation and have a function of being capable of continuously
oxidisdng the particulate substance.
(Fifth Embodiment)
Fig. 5 is a schematic view showing an exhaust gas purifier according
to a fifth embodiment of the invention. The present embodiment is mainly
35

based on the third aspect of the invention. The SOx adsorbent 42 of the
fourth embodiment is neglected in the fifth embodiment. Other
conspirations of the fifth embodiment are similar to those of the fourth
embodiment. Accordingly, the fifth embodiment has similar working
effects except for that associated with the SOx adsorbent of the fourth
embodiment.
During the normal operation, the particulate substance contained in
the exhaust gas is captured by the fine particle filter 40 before flowing into
the NOx adsorbent 4. Accordingly, the NOx adsorbent 4 is hardly clogged
with the particulate substance, and the decrease in adsorption of NOx
adsorbent can be prevented,
During the normal operation, when the amount of particulate
substance adsorbed to the fine particle filter 40 becomes the saturated state
to increase the background pressure, or when the amount of adsorbed NOx
or SOx reaches the predetermined amount (for example, saturated amount),
the normal operation is switched to the regenerating operation as described
above. During the regenerating operation, the particulate substance
captured by the fine particle filter 40 is mainly incinerated and removed to
regenerate the fine particle filter 40 by the burning of the combustion
apparatus 5.
In the case where the regeneration of the NOx adsorbent 4 is
completed while the regeneration of the fine particle filter 40 is not
completed because of the difference in regenerating condition between the
NOx adsorbent 4 and the fine particle filter 40, the adsorbed substance
desorbing means 3 is stopped, and only the combustion apparatus 5 is
36

operated to regenerated only the fine particle filter 40. Because the single
regeneration of the fine particle filter 40 has no influence on the NOx
adsorbent 4 and the like, the combustion apparatus 5 can be operated
according to the regenerating conditions of the fine particle filter 40,
Therefore, the particulate substance can efficiently be removed, and the
wasted consumption of the fuel is eliminated.
(Other Embodiments)
On the second to fifth embodiments, the exhaust passage can be
branched into three or more branch exhaust passages. In such cases, the
exhaust gas may be caused to flow in one of the branch exhaust passages
while the regenerating operation is performed in other branch exhaust
passages, or the regenerating operation may be performed in one of the
branch exhaust passages while the exhaust gas is caused to flow in other
branch exhaust passages.
INDUSTRIAL APPLICABILITY
The invention is utilized as the exhaust gas prifier of the various
internal combustion engines such as the diesel engine, the gas engine, the
gasoline engine, and the gas turbine engine or the like, or the exhaust gas
purifier of the fuel instruments such as the industrial boiler or the like.
Particularly, the invention is suitable to the internal combustion engine in
which the large amount of the NOx is contained in the exhaust gas like the
internal combustion engine operated with the lean burn. The invention is
also applicable to the industrial diesel engine and the like in which the SOx
is contained. Additionally, the invention is suitable to the case in which
37

the heat of the exhaust gas is reused, and the poisoning of the SOx can be
lessened to efficiently recover the exhaust heat.
38

WE CLAIM :
1. An exhaust gas purifier being displaced in an exhaust passage of
an internal combustion engine or a combustion instrument, in the exhaust
passage, the exhaust gas purifier comprising-
a nitrogen oxide adsorbent temporarily adsorbing nitrogen oxide and
desorbmg the adsorbed nitrogen oxide by heating or reducing atmosphere;
adsorbed substance desorbmg means being disposed on an exhaust
gas upstream side of the nitrogen oxide adsorbent, the adsorbed substance
desorbing means heating the exhaust gas or air or converting the exhaust
gas or air into a reducing atmosphere;
a combustion apparatus being disposed on an exhaust gas
downstream side of the nitrogen oxide adsorbent, the combustion apparatus
including air supply means, fuel supply means, and ignition means; and
a filter apparatus being disposed on an exhaust gas downstream
side of the combustion apparatus to be able to capture a particulate
substance contained in the exhaust gas.
2. The exhaust gas purifier according to claim 1, characterized in
that the exhaust passage is branched into a plurality of branch exhaust
passages,
blocking means for being able to block gas flow is provided in an
exhaust gas inlet of each branch exhaust passage,
each branch exhaust passage includes the nitrogen oxide adsorbent,
39

the adsorbed substance desorbing means, the combustion apparatus and the
filter apparatus, and
the adsorbed substance desorbing means includes air supply means
and the adsorbed substance desorbing means is configured to heat air from
the air supply means or to convert the air Into the reducing atmosphere.
3. An exhaust gas purifier being displacod in an exhaust passage of
an internal combustion engine or a combustion instrument, the exhaust gas
purifier characterized in that the exhaust passage branch exhaust passage
is branched into a plurality of branch exhaust passages,
blocking means for being able to block gas flow are provided at an
exhaust gas inlet and an exhaust gas outlet of the branch exhaust passage,
a nitrogen oxide adsorbent, a adsorbed substance desorbing means,
a combustion apparatus, a filter apparatus, and an atmospheric air
releasing portion are provided between the blocking means at the exhaust
gas inlet and exhaust gas outlet of the branch exhaust passage,
the nitrogen oxide adsorbent temporarily adsorbing nitrogen oxide
and desorbing the adsorbed nitrogen oxide by heating or reducing
atmosphere,
the adsorbed substance desorbing means being disposed on an
exhaust gas downstream side of the nitrogen oxide adsorbent, the adsorbed
substance desorbing means including air supply means, the adsorbed
substance desorbing means heating air from the air supply means or
converting the air into a reducing atmosphere,
the combustion apparatus being disposed on an exhaust gas
40

upstream side of the nitrogen oxide adsorbent, the combustion apparatus
including air supply means, fuel supply means, and ignition means*
the filter apparatus being disposed on an exhaust gas upstream side
of the combustion apparatus to be able to capture a particulate substance
contained in the exhaust gas,
the atmospheric air releasing portion being disposed on an exhaust
gas upstream side of the filter apparatus to open the branch exhaust
passage to an atmosphere, and
when the adsorbed substance desorbing means and the combustion
apparatus are operated to perform a regenerating operation, the exhaust
gas inlet and exhaust gas outlet of the branch exhaust passage are blocked
by the blocking means, the branch exhaust passage is opened by the
atmospheric air releasing portion, and gas generated by the regenerating
operation is caused to flow in a direction opposite an exhaust gas flowing
direction and discharged from the atmospheric air releasing portion.
4. An exhaust gas purifier being displaced in an exhaust passage of
an internal combustion engine or a combustion instrument, the exhaust gas
purifier characterized in that the exhaust passage branch exhaust passage
is branched into a plurality of branch exhaust passages,
blocking means for being able to block gas flow are provided at an
exhaust gas inlet and an exhaust, gas outlet of the branch exhaust passage,
a nitrogen oxide adsorbent, a sulfur oxide adsorbent, an adsorbed
substance desorbing means, a combustion apparatus, a filter apparatus, and
an atmospheric air releasing portion are provided between the blocking
41

means at the exhaust gas inlet and exhaust gas outlet of the branch exhaust
passage,
the nitrogen oxide adsorbent temporarily adsorbing nitrogen oxide
and describing the adsorbed nitrogen oxide by heating or reducing
atmosphere,
the sulfur oxide adsorbent being disposed on an exhaust gas
upstream side of the nitrogen oxide adsorbent, the sulfur oxide adsorbent
temporarily adsorbing sulfur oxide and desorbing the adsorbed sulfur oxide
by heating or reducing atmosphere,
the adsorbed substance desorbing means being disposed on an
exhaust gas downstream side of the nitrogen oxide adsorbent, the adsorbed
substance desorbing means including air supply means, the adsorbed
substance desorbing means heating air from the air supply means or
converting the air into a reducing atmosphere,
the combustion apparatus being disposed on an exhaust gas
upstream side of the nitrogen oxide adsorbent, the combustion apparatus
including air supply means, fuel supply means, and ignition means,
the atmospheric air releasing portion being disposed on an exhaust
gas upstream side of the combustion apparatus to open the branch exhaust
passage to an atmosphere, and
when the adsorbed substance desorbing means and the combustion
apparatus are operated to perform a regenerating operation, the exhaust
gas inlet and exhaust gas outlet of the branch exhaust passage are blocked
by the blocking means, the branch exhaust passage is opened by the
atmospheric air releasing portion, and gas generated by the regenerating
42

operation is caused to flow in a direction opposite an exhaust gas flowing
direction and discharged from the atmospheric air releasing portion.
5. The exhaust gas purifier according to claim 4, characterized in
that, in each branch exhaust passage, a filter apparatus which can capture a
particulate substance contained in the exhaust gas is disposed on the
exhaust gas upstream side of the combustion apparatus arid on the exhaust
gas downstream side of the atmospheric air releasing portion.
Dated this 18th day of October 2007.

43

The present invention provides an exhaust gas purifier capable of appropriately purifying harmful components discharged even from an
internal combustion engine or a combustion instrument operated mainly in excess air conditions. Particularly, the exhaust gas purifier is capable of appropriately removing nitrogen oxides, particulate matters including soot, etc. amd in addition, capable of maintaining its purification capability
without reduction, the exhaust gas purifier has, in the exhaust passage (2) of an internal combustion engine (l), a nitrogen oxide adsorbent (4) for temporarily adsorbing nitrogen oxides and desorbing the adsorbed nitrogen
oxides in a temperature increased enviroment or a reducing envioment, an adsorbed substance desorbing means (3) being disposed on an exhaust gas upstream side of the nitrogen oxide adsorbent (4), the adsorbed substance
desorbing means (3) heating the exhaust gas or air or converting the exhaust gas or air into a reducing atmosphere, a combustion apparatus (5)
being disposed on an exhaust gas downstream side of the nitrogen oxide adsorbent (4), the combustion apparatus (4) including air supply means (15), fuel supply means (6), and ignition means (7); and a filter apparatus (40) being disposed on an exhaust gas downstream side of the combustion apparatus (5) to be able to capture a particulate substance contained in the
exhaust gas.

Documents:

04021-kolnp-2007-abstract.pdf

04021-kolnp-2007-claims.pdf

04021-kolnp-2007-correspondence others 1.1.pdf

04021-kolnp-2007-correspondence others 1.2.pdf

04021-kolnp-2007-correspondence others.pdf

04021-kolnp-2007-description complete.pdf

04021-kolnp-2007-drawings.pdf

04021-kolnp-2007-form 1.pdf

04021-kolnp-2007-form 18.pdf

04021-kolnp-2007-form 2.pdf

04021-kolnp-2007-form 3.pdf

04021-kolnp-2007-form 5.pdf

04021-kolnp-2007-international publication.pdf

04021-kolnp-2007-international search report.pdf

04021-kolnp-2007-pa.pdf

04021-kolnp-2007-pct priority document notification.pdf

04021-kolnp-2007-pct request form.pdf

04021-kolnp-2007-translated copy of priority document.pdf

4021-KOLNP-2007-ABSTRACT 1.1.pdf

4021-KOLNP-2007-ABSTRACT 1.2.pdf

4021-KOLNP-2007-ABSTRACT-1.3.pdf

4021-KOLNP-2007-AMANDED CLAIMS.pdf

4021-KOLNP-2007-AMANDED PAGES OF SPECIFICATION.pdf

4021-KOLNP-2007-CANCELLED PAGES 1.2.pdf

4021-KOLNP-2007-CANCELLED PAGES.pdf

4021-KOLNP-2007-CLAIMS 1.1.pdf

4021-KOLNP-2007-CLAIMS-1.2.pdf

4021-KOLNP-2007-CORRESPONDENCE 1.5.pdf

4021-kolnp-2007-correspondence 1.7.pdf

4021-KOLNP-2007-CORRESPONDENCE OTHERS 1.3.pdf

4021-KOLNP-2007-CORRESPONDENCE-1.4.pdf

4021-KOLNP-2007-CORRESPONDENCE-1.6.pdf

4021-kolnp-2007-correspondence.pdf

4021-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

4021-KOLNP-2007-DESCRIPTION (COMPLETE) 1.2.pdf

4021-KOLNP-2007-DESCRIPTION (COMPLETE)-1.3.pdf

4021-KOLNP-2007-DRAWINGS 1.1.pdf

4021-KOLNP-2007-DRAWINGS 1.2.pdf

4021-KOLNP-2007-DRAWINGS-1.3.pdf

4021-kolnp-2007-examination report.pdf

4021-KOLNP-2007-FORM 1 1.2.pdf

4021-KOLNP-2007-FORM 1-1.3.pdf

4021-KOLNP-2007-FORM 1.1.1.pdf

4021-kolnp-2007-form 18.pdf

4021-KOLNP-2007-FORM 2 1.2.pdf

4021-KOLNP-2007-FORM 2-1.3.pdf

4021-KOLNP-2007-FORM 2.1.1.pdf

4021-kolnp-2007-form 3.1.pdf

4021-KOLNP-2007-FORM 3.pdf

4021-KOLNP-2007-FORM-27.pdf

4021-kolnp-2007-granted-abstract.pdf

4021-kolnp-2007-granted-claims.pdf

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Patent Number 246981
Indian Patent Application Number 4021/KOLNP/2007
PG Journal Number 12/2011
Publication Date 25-Mar-2011
Grant Date 23-Mar-2011
Date of Filing 18-Oct-2007
Name of Patentee YANMAR CO., LTD.
Applicant Address 1-32, CHAYAMACHI, KITA-KU, OSAKA-SHI, OSAKA
Inventors:
# Inventor's Name Inventor's Address
1 ONO, TAISUKE C/O YANMAR CO., LTD., 1-32, CHAYAMACHI, KITA-KU, OSAKA-SHI, OSAKA 530-0013
PCT International Classification Number F01N 3/20, F01N 3/36
PCT International Application Number PCT/JP2006/304997
PCT International Filing date 2006-03-14
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2005-093803 2005-03-29 Japan