JP7002528B2 - Diesel engine exhaust gas ceramic filter regeneration method, diesel engine exhaust gas treatment method and diesel engine exhaust gas dust collection system - Google Patents

Description

The present invention relates to a method of regenerating a ceramic filter for collecting particulate matter (PM) in diesel engine exhaust gas. The present invention also relates to a treatment method for collecting particulate matter (PM) in diesel engine exhaust gas. The present invention also relates to a diesel engine exhaust gas dust collection system for collecting particulate matter (PM) in diesel engine exhaust gas.

Various filtration type dust collectors such as bag filters, ceramic filters, and diesel particulate filters (DPFs) are known to collect particulate matter in high-temperature exhaust gas emitted from engines of vehicles, ships, industrial machinery, etc. There is. In the filtration type dust collector, as a regeneration method when the filter is clogged, A) backwashing with high-pressure air, B) combustion regeneration with high-temperature gas, C) combustion regeneration by electric heating, and the like are adopted.

As the method of A), the method described in Japanese Patent No. 3066247 (Patent Document 1) is exemplified. In the publication, a cleaning gas ejection pipe is provided on the downstream side of the ceramic filter, and one or more closed chambers are provided in which the downstream ends of the ceramic filter face all or each predetermined section, and the closed chamber is provided. A method is described in which an inflow / outflow pipe is provided in the air, and a cleaning gas ejected from the ejection pipe is introduced into the closed chamber through the inflow / outflow pipe.

As the method of B), the method described in Japanese Patent No. 3073152 (Patent Document 2) is exemplified. According to the publication, soot dust contained in exhaust gas from a diesel engine is collected by a filter material, and high-temperature incinerator gas is supplied to a part of the filter material that has collected the soot dust to incinerate and filter the soot dust. It describes how to recycle the material.

As the method of C), the method described in Japanese Patent Application Laid-Open No. 2011-236787 (Patent Document 3) is exemplified. In the relevant publication, a tubular body formed by bending a laminated body consisting of a wire mesh heater, a pair of ceramic non-woven fabrics sandwiched from both sides thereof, and a pair of supporting wire mesh laminated on the outside of the ceramic non-woven fabric into a bellows shape. A filter composed of is described. An outer peripheral heater is arranged on the outer peripheral side of the filter. According to the publication, when incinerating particulate matter to regenerate the filter, it is possible to achieve regeneration in a short time by energizing the wire mesh heater and the outer peripheral heater to ensure uniform low-temperature combustion over the entire filter. It is stated that there is.

Japanese Patent No. 3066247 Japanese Patent No. 3073152 Japanese Unexamined Patent Publication No. 2011-236787

The main engine of a ship is usually a two-stroke engine, and C heavy oil is used as fuel. Since the two-stroke engine has high combustion efficiency, the exhaust gas temperature is relatively low at around 250 ° C., and further, the cylinder oil scatters, so that the oil content (SOF) in the exhaust gas tends to be high. Further, since heavy fuel oil C is a poor fuel, it tends to contain a large amount of metal components such as vanadium and nickel in the fuel. Therefore, in the prior art, the following problems occur during filter reproduction.

Backwashing with high-pressure air is effective as a technique for removing particulate matter such as soot and dust from the filter, but has a small cleaning effect on the oil adhering to the filter. In addition, a sufficient cleaning effect cannot be obtained even for particulate matter to which oil is attached. Combustion regeneration by electric heating or high temperature gas makes it difficult to control the temperature inside the filter during combustion, and in some cases, the temperature becomes locally high and the filter may be destroyed. In particular, vanadium contained in the exhaust gas obtained by burning heavy fuel oil C, which is a fuel for a large diesel engine used in ships, has a large adverse effect on ceramics in a high temperature region of 800 ° C. or higher. If the engine is regenerated by heating with vanadium attached to it, the filter may melt due to the heat of combustion. Therefore, it becomes necessary to use an expensive material such as silicon carbide.

The present invention has been created in view of the above circumstances, and provides a method for regenerating a ceramic filter for diesel engine exhaust gas, which is excellent in cleaning effect of particulate matter and oil adhering to the ceramic filter and has less damage to the ceramic filter. One of the challenges is to do. Another object of the present invention is to provide a method for treating diesel engine exhaust gas using such a regeneration method. Further, the present invention makes it one of still another subject to provide a diesel engine exhaust gas dust collection system.

As a result of diligent studies to solve the above problems, the present inventor has found that the following regeneration method combining high-pressure gas backwashing and low-temperature heating is effective.

In the first aspect of the present invention, the particulate matter in the exhaust gas of a diesel engine using heavy fuel oil C and the ceramic filter to which the oil adheres are backwashed with a high-pressure gas to carry out the backwashing of the particulate matter. Is a method for regenerating a diesel engine exhaust gas ceramic filter, which comprises a step A of removing oil from the ceramic filter and a step B of heating the ceramic filter to 300 ° C. to 500 ° C. to volatilize and remove oil from the ceramic filter.

In one embodiment of the regeneration method according to the present invention, the diesel engine is a main engine for ships.

In another embodiment of the regeneration method according to the present invention, step B includes heating the ceramic filter to 350 ° C. or higher.

Yet another embodiment of the regeneration method according to the present invention includes using the exhaust gas after dust collection discharged from the outlet of the dust collector for diesel engine exhaust gas as the heat source of the step B.

Yet another embodiment of the regeneration method according to the present invention includes using the auxiliary engine exhaust gas as a heat source in step B.

In yet another embodiment of the regeneration method according to the present invention, step B comprises passing the gas heated by the heater through the ceramic filter.

The present invention is a method for treating diesel engine exhaust gas using two or more ceramic filters in the second aspect.
The two or more ceramic filters are configured to be able to introduce the exhaust gas of a common diesel engine that uses heavy fuel oil C as fuel.
While the regeneration method according to the present invention is being carried out for at least one ceramic filter among the two or more ceramic filters, at least one system different from the at least one ceramic filter for which the regeneration method is being carried out. This is a method for treating diesel engine exhaust gas, which comprises treating the exhaust gas with the ceramic filter of the above.

In one embodiment of the method for treating diesel engine exhaust gas according to the present invention, the two or more ceramic filters are configured to be able to introduce gas heated by a common heater, and the regeneration method according to the present invention is carried out. This includes introducing the gas heated by the heater into the at least one ceramic filter system to carry out the step B.

In still another embodiment of the method for treating diesel engine exhaust gas according to the present invention, one or two or more dust collectors containing two or more ceramic filters are used.

In still another embodiment of the method for treating diesel engine exhaust gas according to the present invention, two or more dust collectors containing one system of ceramic filters are used.

Further, in the third aspect, the present invention is a diesel engine exhaust gas dust collection system using two or more ceramic filters.
The two or more ceramic filters are configured to be able to introduce the exhaust gas of a common diesel engine that uses heavy fuel oil C as fuel.
While the regeneration method according to the present invention is being carried out for at least one ceramic filter among the two or more ceramic filters, at least one system different from the at least one ceramic filter for which the regeneration method is being carried out. It is a diesel engine exhaust gas dust collection system configured to be able to treat the exhaust gas with the ceramic filter of.

In one embodiment of the diesel engine exhaust gas dust collection system according to the third aspect of the present invention, the two or more ceramic filters are configured to be capable of introducing gas heated by a common heater.
The process B can be carried out by introducing the gas heated by the heater into the at least one ceramic filter that implements the regeneration method according to the present invention.

In another embodiment of the diesel engine exhaust gas dust collecting system according to the third aspect of the present invention, one or two or more dust collectors containing two or more ceramic filters are used.

In still another embodiment of the diesel engine exhaust gas dust collecting system according to the third aspect of the present invention, two or more dust collectors containing one ceramic filter are used.

In the fourth aspect, the present invention
Diesel engine exhaust gas equipped with two or more ceramic filters, two or more exhaust gas introduction valves, two or more regeneration gas introduction valves, two or more backwash valves, a backwash gas tank, and a heater. It ’s a dust collection system.
The two or more ceramic filters are configured so that the exhaust gas of a common diesel engine using heavy fuel oil C as fuel can be introduced from the upstream side via the exhaust gas introduction valve of the corresponding system.
The two or more ceramic filters are configured so that gas heated to 300 ° C. to 500 ° C. with a common heater can be introduced from the upstream side via the regeneration gas introduction valve of the corresponding system.
The two or more ceramic filters are configured so that the backwash gas supplied from the backwash gas tank can be introduced from the downstream side via the backwash valve of the corresponding system.
Diesel engine exhaust gas dust collection system.

In one embodiment of the diesel engine exhaust gas dust collection system according to the fourth aspect of the present invention,
A circulation duct for supplying the exhaust gas after dust collection discharged from the downstream side of the two or more ceramic filters to the heater is provided.

In another embodiment of the diesel engine exhaust gas dust collection system according to the fourth aspect of the present invention,
The two or more ceramic filters are configured so that the auxiliary engine exhaust gas can be introduced from the upstream side via the regeneration gas introduction valve of the corresponding system.

In still another embodiment of the diesel engine exhaust gas dust collecting system according to the fourth aspect of the present invention, one or two or more dust collectors containing two or more ceramic filters are used.

In still another embodiment of the diesel engine exhaust gas dust collecting system according to the fourth aspect of the present invention, two or more dust collectors containing one ceramic filter are used.

The method for regenerating a ceramic filter for diesel engine exhaust gas according to the present invention is excellent in cleaning effect of particulate matter and oil adhering to the ceramic filter. In addition, the same reproduction method causes less damage to the ceramic filter. Therefore, particulate matter in the exhaust gas of a diesel engine having a large oil content can be stably collected for a long period of time, and maintenance of the dust collector becomes easy. Therefore, the present invention can be suitably used for collecting particulate matter in the exhaust gas obtained by burning heavy fuel oil C, which is a fuel for a large diesel engine used in a ship.

It is a configuration example of a diesel engine exhaust gas dust collection system to which the regeneration method of the ceramic filter type dust collector according to the present invention can be applied. This is a configuration example of a diesel engine exhaust gas dust collector system when a plurality of ceramic filter type dust collectors are installed. It is the TG-DTA measurement result of the soot to which the oil content in the exhaust gas from the ship main engine adhered. It is a schematic diagram explaining the mechanism of dust collection and backwash by a columnar ceramic filter.

(1. Exhaust gas and dust collector targeted by the present invention)
Diesel fuel includes light oil, A heavy oil, C heavy oil and the like. Of these, C heavy oil is often used as diesel fuel for large ships, but the exhaust gas of a diesel engine using C heavy oil tends to have a higher oil content (SOF) than when other diesel fuels are used. For example, the exhaust gas of a diesel engine fueled by heavy fuel oil C contains an oil content (normal hexane extract substance) of 10 mg / Nm ³ or more as measured by the n-hexane absorption weight method (Environment Agency Notification No. 64). It may contain 20 mg / Nm ³ or more of oil, and may also contain 30 mg / Nm ³ or more of oil. Further, since heavy fuel oil C is a poor fuel, it tends to contain a large amount of metal components such as vanadium and nickel in the fuel. Therefore, when the exhaust gas of a diesel engine using heavy fuel oil C is treated by a dust collector equipped with a ceramic filter (in the present specification, the dust collector equipped with a ceramic filter may be referred to as a "ceramic filter type dust collector"). , There is a problem when regenerating the filter, which was not a problem with other fuels.

In a general filtration type dust collector, when the amount of particulate matter collected in the filter becomes large and the differential pressure between the upstream and downstream of the filter becomes large, the particulate matter is removed from the filter and the filter is regenerated. Is done. Examples of the filter regeneration method include backwashing with high-pressure air, electric heating, or combustion regeneration with high-temperature gas. As described above, in these methods, particulate matter in the exhaust gas of a diesel engine using C heavy oil as fuel ( It is not suitable for regeneration of a ceramic filter type dust collector for collecting PM). On the other hand, the present invention can be suitably used for regeneration of a ceramic filter type dust collector for collecting particulate matter (PM) in the exhaust gas of a diesel engine using heavy fuel oil C as fuel.

C heavy oil is classified according to JIS standard (K2205: 1991). The international names corresponding to C heavy oil are MFO (Marine Fuel Oil: fuel oil for ships), HFO (Heavy Fuel Oil: heavy fuel oil) and RFO (Residal Fuel Oil: residual fuel oil). For reference, Table 1 shows the international names corresponding to heavy fuel oil A and heavy oil C.

The ship is equipped with a main engine for advancing the ship and an auxiliary engine for generating electricity used in the ship. A 4-stroke engine is used as the auxiliary engine, the exhaust gas temperature is relatively high at 350 ° C or higher, and the oil content in the exhaust gas is small, but the main engine is usually a 2-stroke engine, and the 2-stroke engine burns. Due to its high efficiency, the exhaust gas temperature is relatively low, around 250 ° C., and the oil content in the exhaust gas is extremely high compared to the ship auxiliary engine that uses the same heavy C oil. Therefore, the present invention can be particularly suitably used for regeneration of a ceramic filter type dust collector for collecting particulate matter (PM) in the exhaust gas of a marine main engine using heavy fuel oil C as fuel.

Various ceramic filter type dust collectors are known, and the present invention can be used for various ceramic filter type dust collectors without particular limitation. The material of the ceramic filter is not limited, but examples thereof include cordierite and silicon carbide. Among these, cordierite, which has a low cost, is preferable. The structure of the ceramic filter includes, but is not limited to, a honeycomb structure having a plurality of cells partitioned by porous partition walls. While the exhaust gas passes through the cell, particulate matter (PM) is separated from the exhaust gas and collected. The shape of the ceramic filter is not limited, but can be a prism such as a polygonal prism (such as a quadrangular prism) or a cylinder. The columnar filter can be configured so that the dust collection treatment can be performed by allowing the untreated gas to flow in from one bottom surface and the treated gas to flow out from the other bottom surface.

Illustratively, as shown in FIG. 4, a plurality of first cells 401 in which the upstream end face is opened and the downstream end face is sealed, and the upstream end face is sealed and the downstream end face is closed. A columnar ceramic filter 400 having a honeycomb structure having a plurality of second cells 402 having an open end face can be mentioned. In this type of ceramic filter 400, particulate matter 404 is collected by the following mechanism (see the left figure of FIG. 4). When the exhaust gas is supplied to the end face on the upstream side, the exhaust gas is introduced into the first cell 401 and proceeds downstream in the first cell 401. Since the end face on the downstream side of the first cell 401 is sealed, the exhaust gas passes through the porous partition wall separating the first cell 401 and the second cell 402 and flows into the second cell. Since the particulate matter 404 cannot pass through the partition wall, it is collected in the first cell 401. The oil content in the exhaust gas is also collected in the first cell 401. The exhaust gas that has flowed into the second cell 402 proceeds downstream in the second cell 402 and is discharged from the end face on the downstream side.

Further, the backwashing of this type of ceramic filter 400 can be performed as follows (see the right figure of FIG. 4). When the cleaning gas 406 is injected toward the downstream end face of the ceramic filter 400, the cleaning gas 406 advances upstream in the second cell 402 of the ceramic filter 400. Since the upstream end face of the second cell 402 is sealed, the cleaning gas 406 passes through the porous partition wall separating the first cell 401 and the second cell 402 and passes through the first cell 401. Inflow to. The cleaning gas 406 flowing into the first cell 401 travels upstream in the first cell 401 and is accompanied by the particulate matter 404 collected in the first cell 401 on the upstream side. It is discharged from the end face. However, the oil collected in the first cell 401 cannot be sufficiently discharged by backwashing.

In the present specification, the upstream side of the ceramic filter refers to the side where the exhaust gas before dust collection flows into the ceramic filter, and the downstream side of the ceramic filter is the side where the exhaust gas after dust collection flows out from the ceramic filter. Point to.

(2. How to regenerate the ceramic filter)
When regenerating the ceramic filter of a ceramic filter type dust collector that targets the exhaust gas of a diesel engine using C heavy oil, it is important how to remove the oil while avoiding damage to the filter. In the present invention, a method is adopted in which the ceramic filter is heated at a relatively low temperature such that the oil content volatilizes but the graphite does not burn. As a result, oil can be removed with high efficiency without damaging the filter. Therefore, in one embodiment of the method for regenerating a ceramic filter for diesel engine exhaust gas according to the present invention, a high-pressure gas is used with respect to a ceramic filter to which particulate matter and oil are adhered in the exhaust gas of a diesel engine using heavy fuel oil C as fuel. A step of removing particulate matter from the ceramic filter by performing backwashing using the above, and a step B of heating the ceramic filter to 300 ° C. to 500 ° C. to volatilize and remove oil from the ceramic filter. ..

In step A, particulate matter is removed from the ceramic filter by performing backwashing with a high-pressure gas. As the high-pressure gas, for example, a compressed gas having a gauge pressure of 0.1 MPa or more, typically 0.2 to 1 MPa, and more typically 0.3 to 0.7 MPa can be used. The type of high-pressure gas is not limited, but examples thereof include air, an inert gas such as nitrogen and argon, and water vapor. Among these, it is preferable to use air which is inexpensive and has versatility. The time required for one backwash and the frequency of backwash may be appropriately set according to the amount of particulate matter collected.

In step A, mainly particulate matter is removed from the ceramic filter. Particulate matter includes soot and dust. It is difficult to sufficiently remove the oil itself and the particulate matter to which a large amount of oil is attached from the ceramic filter by backwashing.

In step B, the ceramic filter is heated to volatilize and remove oil from the ceramic filter. FIG. 3 shows the TG-DTA measurement results of soot with oil in the exhaust gas from the ship's main engine. Looking at the TG curve, a weight decrease is observed from around 300 ° C., and a rapid weight decrease is observed around 350 ° C. Further, looking at the DTA curve, the calorific value increases from around this temperature, and the calorific value becomes maximum at 388.9 ° C. From this result, it is considered that when heated to 300 ° C. or higher, the oil content in the soot volatilizes and partially starts combustion at around 390 ° C.

Therefore, in order to volatilize and remove oil from the ceramic filter, it is preferable to heat the ceramic filter to 300 ° C. or higher, and more preferably to 350 ° C. or higher.

On the other hand, if the heating temperature is set too high, graphite in the soot will burn, and the temperature will rise further due to the heat of combustion, making temperature control difficult. Damage to the ceramic filter by vanadium cannot be ignored. In addition, the amount of energy consumed for heating becomes large, which is uneconomical. Therefore, the heating temperature for volatilizing and removing oil from the ceramic filter is preferably 500 ° C. or lower, more preferably 450 ° C. or lower. The time required for one heating operation and the frequency of the heating operation may be appropriately set according to the amount of oil collected.

When heating the ceramic filter, it is preferable to allow the gas heated to 300 to 500 ° C. to pass through the ceramic filter because the volatilized oil is easily accompanied by the gas and discharged. It is preferable that the heated gas flows from the upstream side to the downstream side of the ceramic filter in the same manner as the exhaust gas. As a heat source for heating the ceramic filter, it is conceivable to use a heater using liquid fuel, electricity, or the like. It can also be configured so that the gas heated by the heater passes through the ceramic filter.

However, when the outside air is heated or the filter is directly heated by the heater, it is necessary to heat the filter to 300 ° C. or higher from the ambient temperature, so that the energy consumption becomes large. Therefore, it is preferable to heat using waste heat. For example, clean exhaust gas discharged from the outlet of a ceramic filter type dust collector targeting the exhaust gas of a diesel engine using heavy fuel oil C can be circulated and used. Since the temperature of the exhaust gas discharged from the outlet of the ceramic filter type dust collector is, for example, about 250 ° C., the amount of energy required for heating to the required temperature is small.

Further, when the oil content in the exhaust gas from the auxiliary engine is low (eg, 5 mg / Nm ³ or less), the ceramic filter may be heated by passing the exhaust gas through the ceramic filter. When the temperature of the exhaust gas from the auxiliary engine is 300 ° C. or higher, no heater is required. When the exhaust gas from the auxiliary engine is passed through the ceramic filter, there is an advantage that the oil content in the ceramic filter can be volatilized and removed while the particulate matter in the exhaust gas is collected by the ceramic filter.

The order in which the steps A and B are carried out is not particularly limited, and the steps A and B may be appropriately combined and carried out according to the amount of the particulate matter and the oil content collected in the ceramic filter. Therefore, the process B may be carried out after the step A is carried out, or the step A may be carried out after the step B is carried out. It is also possible to carry out step A and step B alternately. Step B may be carried out after carrying out step A a plurality of times. Step A may be carried out after carrying out step B a plurality of times.

(3. Diesel engine exhaust gas treatment method)
In order to prevent the processing of diesel engine exhaust gas from being delayed during the regeneration of the ceramic filter, it is possible to prepare multiple systems of ceramic filters and treat the diesel engine exhaust gas using a ceramic filter different from the ceramic filter being regenerated. desirable.

Therefore, the present invention is further a method for treating diesel engine exhaust gas using two or more ceramic filters.
The two or more ceramic filters are configured to be able to introduce the exhaust gas of a common diesel engine that uses heavy fuel oil C as fuel.
While the method for regenerating the ceramic filter according to the present invention is being carried out for at least one of the two or more ceramic filters, the ceramic filter is different from the at least one ceramic filter for which the regenerating method is being carried out. Provided is a method for treating diesel engine exhaust gas, which comprises treating the exhaust gas with at least one ceramic filter.

Each of the two or more ceramic filters can be configured so that the gas heated by the heater can be introduced. When the gas heated by the heater passes through the ceramic filter, the oil adhering to the ceramic filter can be volatilized and removed. It is possible to install one heater for each ceramic filter of one system, but it is not necessary to assume that all the ceramic filters of all systems are subjected to heat treatment for regeneration at the same time. Therefore, in consideration of economic efficiency, the two or more dust collectors are configured so that the gas heated by a common heater can be introduced, and the heater is selectively used for at least one ceramic filter that implements the method for regenerating the ceramic filter. It is preferable to carry out step B by introducing heated gas.

In one embodiment of the method for treating diesel engine exhaust gas according to the present invention, each ceramic filter of two or more ceramic filters has passed a time zone for exhaust gas collection treatment and a time zone for regeneration. However, these time zones are repeated alternately. Switching between the time zone used for the exhaust gas dust collection treatment and the time zone for regeneration may be appropriately set according to the degree of deterioration in the performance of the exhaust gas dust collection treatment. It can be done at least based on the filter differential pressure.

The above method for treating diesel engine exhaust gas may be carried out by using one or two or more dust collectors containing two or more ceramic filters, or two dust collectors containing one ceramic filter. It may be carried out by using the above. Further, a dust collector containing two or more ceramic filters and a dust collector containing one ceramic filter may be used in combination. The ceramic filter of one system refers to a ceramic filter that is housed in the same chamber in the same dust collector and has the same timing of exhaust gas treatment and regeneration. Even when a plurality of ceramic filters are used in the same chamber, the plurality of ceramic filters constitute one system of ceramic filters as long as the above conditions are satisfied.

(4. Diesel engine exhaust gas dust collection system)
Hereinafter, a specific example of a method for treating diesel engine exhaust gas using the method for regenerating the ceramic filter according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration example of a diesel engine exhaust gas dust collecting system to which the method for regenerating the ceramic filter type dust collector according to the present invention can be applied. The diesel engine exhaust gas dust collection system 100 includes an inlet three-way valve 102 connected to an exhaust gas duct 121 from a diesel engine 101 using heavy fuel oil C, two exhaust gas introduction valves 103a and 103b, and two systems for introducing regenerative gas. It includes valves 104a and 104b, a ceramic filter type dust collector 110, a heater 105, an air tank 106, and two systems of backwash valves 107a and 107b. The ceramic filter type dust collector 110 includes a can body 112, two systems of ceramic filters 114a and 114b housed in the can body 112, two systems of exhaust gas / regeneration gas inlets 115a and 115b, an exhaust gas outlet 117, and a PM recovery box 118. , It is provided with two systems of backwash gas introduction ports 119a and 119b. The diesel engine exhaust gas dust collector system 100 may further install an exhaust fan 130 on the downstream side of the ceramic filter type dust collector 110 in order to reduce the back pressure on the engine.

The exhaust gas from the diesel engine 101 flowing through the exhaust gas duct 121 is switched between being sent to the ceramic filter type dust collector 110 and being sent to the bypass duct 122 at the inlet three-way valve 102. When the exhaust gas is sent to the ceramic filter type dust collector 110, the dust collection treatment is performed, and when the exhaust gas is sent to the bypass duct 122 such as in an emergency, the exhaust gas is discharged from the chimney without being treated.

The ceramic filter type dust collector 110 includes two systems of ceramic filters 114a and 114b in the can body 112. The inside of the can body 112 is divided into a chamber 112a for the first system and a chamber 112b for the second system, and the gas in both chambers does not mix on the upstream side of the filter. The first system ceramic filter 114a passes through the first system exhaust gas introduction valve 103a and collects the exhaust gas introduced into the first system chamber 112a from the first system exhaust gas / regeneration gas introduction port 115a. Can be processed. The second system ceramic filter 114b passes through the second system exhaust gas introduction valve 103b, and collects the exhaust gas introduced into the second system chamber 112b from the second system exhaust gas / regeneration gas introduction port 115b. Can be processed.

By switching the opening and closing of the exhaust gas introduction valves 103a and 103b of the two systems, it is determined whether the ceramic filter of the first system or the second system performs the exhaust gas collection treatment. It is also possible to open both the two exhaust gas introduction valves 103a and 103b and collect dust simultaneously with the two ceramic filters 114a and 114b. It is preferable to alternately collect dust during regeneration in order to prevent troubles.

The exhaust gas is cleaned by being subjected to dust collection treatment by the ceramic filters 114a and 114b, and then discharged from the exhaust gas outlet 117 of the ceramic filter type dust collector 110. The exhaust gas discharged from the exhaust gas outlet 117 of the ceramic filter type dust collector 110 can finally be discharged to the atmosphere from the chimney through the exhaust gas duct 124.

The diesel engine exhaust gas dust collection system 100 can further include a circulation duct 125 for supplying the exhaust gas after dust collection discharged from the downstream side of the ceramic filters 114a and 114b to the heater 105. One of the circulation ducts 125 can be connected to the exhaust gas duct 124, and the other can be directly or indirectly connected to the ceramic filter type dust collector 110. A regeneration fan 131 and a heater 105 are installed in the middle of the circulation duct 125. The clean exhaust gas discharged from the exhaust gas outlet 117 flows through the circulation duct 125 and is heated to the required temperature when passing through the heater 105. The heated exhaust gas can be supplied to the ceramic filter of either or both of the first system and the second system by switching the opening and closing of the two systems of the regeneration gas introduction valves 104a and 104b.

The ceramic filter 114a of the first system passes through the regeneration gas introduction valve 104a of the first system and is introduced into the chamber 112a for the first system from the exhaust gas / regeneration gas introduction port 115a of the first system for regeneration. It is possible to receive the heat regeneration treatment (step B) by the gas. The ceramic filter 114b of the second system passes through the regeneration gas introduction valve 104b of the second system, and is introduced into the chamber 112b for the second system from the exhaust gas / regeneration gas introduction port 115b of the second system. It is possible to receive the heat regeneration treatment (step B) by the gas.

Looking at FIG. 1, the exhaust gas introduction valve 103a of the first system is “open”, and the regeneration gas introduction valve 104a of the first system is “closed”. Therefore, it can be seen that the exhaust gas from the diesel engine 101 flows into the ceramic filter 114a of the first system, and the dust collection treatment is being carried out by the ceramic filter 114a of the first system. Further, the exhaust gas introduction valve 103b of the second system is "closed", and the regeneration gas introduction valve 104b of the second system is "open". Therefore, it can be seen that step B (removal of volatilization of oil) is being carried out for the ceramic filter 114b of the second system using the regenerating gas heated by the heater 105.

The diesel engine exhaust gas dust collecting system 100 can supply outside air to the ceramic filter type dust collector 110 by installing an outside air duct 127 for supplying outside air in place of the circulation duct 125 or in addition to the circulation duct 125. It may be configured in. In the diesel engine exhaust gas dust collection system 100 shown in FIG. 1, an outside air duct 127 capable of flowing the outside air taken in from the outside air intake port 128 by using the suction force of the regeneration fan 131 is connected to the circulation duct 125 in front of the heater 105. Has been done. In the front stage of the heater 105, valves 129a and 129b are installed in the circulation duct 125 and the outside air duct 127, respectively, and the gas flow rate passing through the heater 105 can be adjusted by opening / closing or opening the valves 129a and 129b, respectively. .. With this configuration, only the exhaust gas from the circulation duct 125 can flow to the heater 105, only the outside air from the outside air duct 127 can flow to the heater 105, or the exhaust gas from the circulation duct 125 and the outside air duct 127 can flow. Both outside air can be passed through the heater 105 at the same time.

Further, backwash gas introduction ports 119a and 119b are arranged on the downstream side of the two ceramic filters 114a and 114b, respectively. After leaving the air tank 106, the ceramic filter 114a of the first system flows through the backwash gas pipe 126, passes through the backwash valve 107a of the first system, and flows in from the backwash gas introduction port 119a of the first system. Receive backwash by air. After leaving the air tank 106, the ceramic filter 114b of the second system flows through the backwash gas pipe 126, passes through the backwash valve 107b of the second system, and flows in from the backwash gas introduction port 119b of the second system. Receive backwash by air. By switching the opening and closing of the two systems of backwash valves 107a and 107b, the compressed air is determined to which ceramic filter of the first system or the second system is sent.

Particulate matter discharged from the upstream side of the ceramic filters 114a and 114b by the backwash is dropped by gravity and can be collected in the PM collection box 118 installed at the bottom of the can body 112.

Next, FIG. 2 shows another configuration example of a diesel engine exhaust gas dust collecting system to which the method for regenerating the ceramic filter type dust collector according to the present invention can be applied. In the diesel engine exhaust gas dust collection system 100 shown in FIG. 1, two ceramic filters 114a and 114b are installed in one ceramic filter type dust collector 110, and the two ceramic filters 114a and 114b are subjected to dust collection treatment. It was a system that could continuously treat exhaust gas by alternately switching filter regeneration. On the other hand, in the diesel engine exhaust gas dust collector system 200 shown in FIG. 2, one ceramic filter type dust collector has only one system of ceramic filters, and such ceramic filter type dust collectors 210a, 210b, 210c. Are arranged in parallel. For the plurality of ceramic filter type dust collectors 210a, 210b, 210c, it is possible to continuously treat the exhaust gas by switching the dust collecting process and the filter regeneration in order.

The diesel engine exhaust gas dust collection system 200 includes an inlet three-way valve 202 connected to an exhaust gas duct 221 from a two-stroke diesel engine 201 of a ship's main engine, three exhaust gas introduction valves 203a, 203b, 203c, and three systems of recycling gas introduction. It is provided with valves 204a, 204b, 204c, three ceramic filter type dust collectors 210a, 210b, 210c, a heater 205, an air tank 206, and three systems of backwash valves 207a, 207b, 207c. The ceramic filter type dust collectors 210a, 210b and 210c have one system of exhaust gas / regeneration gas inlets 215a, 215b and 215c, one system of exhaust gas outlets 217a, 217b and 217c, and one system of backwash gas inlets 219a and 219b, respectively. , 219c. The diesel engine exhaust gas dust collector system 200 may further install an exhaust fan 230 on the downstream side of the ceramic filter type dust collectors 210a, 210b, 210c in order to reduce the back pressure on the engine.

The exhaust gas from the diesel engine 201 flowing through the exhaust gas duct 221 is switched between being sent to the ceramic filter type dust collectors 210a, 210b and 210c and being sent to the bypass duct 222 at the inlet three-way valve 202. When the exhaust gas is sent to the ceramic filter type dust collectors 210a, 210b, 210c, the dust collection treatment is performed, and when the exhaust gas is sent to the bypass duct 222 such as in an emergency, the exhaust gas is discharged from the chimney untreated.

The three ceramic filter type dust collectors 210a, 210b, 210c each have one system of ceramic filters 214a, 214b, 214c. The ceramic filter 214a of the first system passes through the exhaust gas introduction valve 203a of the first system, and exhaust gas introduced into the ceramic filter type dust collector 210a of the first system from the exhaust gas / regeneration gas introduction port 215a of the first system. Can be dust-collected. The ceramic filter 214b of the second system passes through the exhaust gas introduction valve 203b of the second system, and exhaust gas introduced into the ceramic filter type dust collector 210b of the second system from the exhaust gas / regeneration gas introduction port 215b of the second system. Can be dust-collected. The ceramic filter 214c of the third system passes through the exhaust gas introduction valve 203c of the third system, and exhaust gas introduced into the ceramic filter type dust collector 210c of the third system from the exhaust gas / regeneration gas introduction port 215c of the third system. Can be dust-collected.

By switching the opening and closing of the exhaust gas introduction valves 203a, 203b, and 203c of the three systems, it is determined which of the ceramic filters of the first system, the second system, and the third system performs the exhaust gas collection treatment. It is also possible to open all three exhaust gas introduction valves 203a, 203b, 203c and collect dust at the same time with the three ceramic filters 214a, 214b, 214c, and open only the two exhaust gas introduction valves to make the two ceramic filters. It is also possible to collect dust at the same time, or to open only one system of exhaust gas introduction valve and collect dust with one system of ceramic filter.

The exhaust gas is cleaned by being subjected to dust collection treatment by the ceramic filters 214a, 214b and 214c, and then discharged from the exhaust gas outlets 217a, 217b and 217c of the ceramic filter type dust collectors 210a, 210b and 210c. The exhaust gas discharged from the exhaust gas outlets 217a, 217b, and 217c can be finally discharged to the atmosphere from the chimney through the exhaust gas duct 224.

Further, the three ceramic filter type dust collectors 210a, 210b, and 210c are connected to the exhaust gas duct 223 from the 4-stroke diesel engine 220 of the ship auxiliary machine, respectively. The exhaust gas flowing through the exhaust gas duct 223 is made of any one, two or all ceramics of the first system, the second system and the third system by switching the opening and closing of the three systems of the recycling gas introduction valves 204a, 204b and 204c. It can be supplied to the filter. When the oil content in the exhaust gas from the 4-stroke diesel engine 220 of the ship auxiliary machine is small and the temperature of the exhaust gas is in the range of 300 to 500 ° C., the exhaust gas can be used as it is as a recycling gas.

The first system ceramic filter 214a passed through the first system regeneration gas introduction valve 204a and was introduced into the first system ceramic filter type dust collector 210a from the first system exhaust gas / regeneration gas introduction port 215a. It is possible to receive the heat regeneration treatment (step B) by the regeneration gas. The ceramic filter 214b of the second system passes through the regeneration gas introduction valve 204b of the second system, and is introduced into the ceramic filter type dust collector 210b of the second system from the exhaust gas / regeneration gas introduction port 215b of the second system. It is possible to receive the heat regeneration treatment (step B) by the gas. The ceramic filter 214c of the third system passes through the regeneration gas introduction valve 204c of the third system, and is introduced into the ceramic filter type dust collector 210c of the third system from the exhaust gas / regeneration gas introduction port 215c of the third system. It is possible to receive the heat regeneration treatment (step B) by the gas.

Looking at FIG. 2, the exhaust gas introduction valve 203a of the first system and the exhaust gas introduction valve 203b of the second system are “open”, and the regeneration gas introduction valve 204a of the first system and the regeneration gas of the second system are “open”. The introduction valve 204b is "closed". Therefore, the exhaust gas from the diesel engine 201 flows into the ceramic filter type dust collector 210a of the first system and the ceramic filter type dust collector 210b of the second system, and is collected by the ceramic filter 214a of the first system and the ceramic filter 214b of the second system. It can be seen that dust treatment is in progress. Further, the exhaust gas introduction valve 203c of the third system is "closed", and the regeneration gas introduction valve 204c of the third system is "open". Therefore, the regenerating gas flows into the ceramic filter type dust collector 210c of the third system, and the ceramic filter 214c of the third system is performing step B (volatile removal of oil) using the regenerating gas. I understand. However, the ceramic filter 214c of the third system can collect particulate matter in the exhaust gas from the 4-stroke diesel engine 220 of the ship auxiliary machine even during regeneration.

The diesel engine exhaust gas dust collection system 200 supplies outside air to the ceramic filter type dust collectors 210a, 210b, 210c by installing an outside air duct 227 that supplies outside air in place of the exhaust gas duct 223 or in addition to the exhaust gas duct 223. It may be configured so that it can be used. In the diesel engine exhaust gas dust collection system 200 shown in FIG. 2, an outside air duct 227 capable of flowing outside air taken in from the outside air intake port 228 by using the suction force of the regeneration fan 231 is connected to the exhaust gas duct 223. A heater 205 is installed after the regeneration fan 231 in the middle of the outside air duct 227, and the taken-in outside air can be heated to a required temperature. A valve 229a is installed in the outside air duct 227, and the amount of outside air introduced can be adjusted by opening / closing or opening / closing the valve 229a. The amount of outside air introduced may be adjusted so as to satisfy appropriate conditions for the recycled gas according to the temperature, flow rate, oil content concentration, etc. of the exhaust gas from the 4-stroke diesel engine 220 of the ship auxiliary machine.

The diesel engine exhaust gas dust collecting system 200 can further include a circulation duct 225 for supplying the exhaust gas after dust collected discharged from the downstream side of the ceramic filters 214a, 214b, and 214c to the heater 205. One of the circulation ducts 225 can be connected to the exhaust gas duct 224, and the other can be directly or indirectly connected to the ceramic filter type dust collectors 210a, 210b, 210c. In the illustrated embodiment, the circulation duct 225 is connected to the outside air duct 227 at the front stage of the regeneration fan 231 and the front stage of the heater 205. A valve 229b is installed in the circulation duct 225 in the previous stage connected to the outside air duct 227, and the gas flow rate passing through the heater 205 via the circulation duct 225 can be adjusted by opening / closing or opening the valve 229b.

Further, backwash gas introduction ports 219a, 219b, and 219c are arranged on the downstream side of the three ceramic filter type dust collectors 210a, 210b, and 210c, respectively. After leaving the air tank 206, the ceramic filter 214a of the first system flows through the backwash gas pipe 226, passes through the backwash valve 207a of the first system, and passes from the backwash gas introduction port 219a of the first system to the first system. It is backwashed by the compressed air flowing into the ceramic filter type dust collector 210a. After leaving the air tank 206, the ceramic filter 214b of the second system flows through the backwash gas pipe 226, passes through the backwash valve 207b of the second system, and passes from the backwash gas introduction port 219b of the second system to the second system. It is backwashed by the compressed air flowing into the ceramic filter type dust collector 210b. After leaving the air tank 206, the ceramic filter 214c of the third system flows through the backwash gas pipe 226, passes through the backwash valve 207c of the third system, and passes from the backwash gas introduction port 219c of the third system to the third system. It is backwashed by the compressed air flowing into the ceramic filter type dust collector 210c. By switching the opening and closing of the three systems of backwash valves 207a, 207b, and 207c, the compressed air is determined to be sent to the ceramic filter of the first system, the second system, or the third system.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)
The effect of the present invention was demonstrated by installing the diesel engine exhaust gas dust collection system shown in FIG. 1 on a ship and performing dust collection treatment of exhaust gas from the main engine 2-stroke diesel engine using heavy fuel oil C. When the exhaust gas was sampled and the dust concentration was measured according to JIS Z8888: 2013, it was 110 mg / Nm ³ , and when the oil content was measured according to the n-hexane absorption gravimetric method, it was 35 mg / Nm ³ . The dust measured in accordance with JIS Z8888: 2013 also includes soot.
The operating conditions are as follows.
・ Diesel engine exhaust gas temperature: fluctuates depending on the time of day at about 150 to 350 ° C ・ Filter: Filter made by Cordierite manufactured by NGK Insulators, Ltd. (Product name: Ceralek)
・ Backwash (step A) frequency: about 1 time / 30 minutes ・ Backwash method: 1 time backwashing process injects compressed air with a gauge pressure of 0.5 MPa for 0.1 seconds ・ Heat regeneration (step B) frequency 1 time / 6 hours ・ Heating regeneration method: Performed by passing the outside air heated to 450 ° C with an electric heater through a filter for about 30 minutes per heating regeneration.
-Dust collection / regeneration switching timing of the two filters 114a and 114b: Switching at the timing of performing heating regeneration

When the exhaust gas dust collection treatment was performed under the above operating conditions, the differential pressure of the filter was stable for 1100 hours from the start of the test, and the exhaust gas dust collection treatment could be continuously performed.

(Comparative Example 1)
Exhaust gas dust collection treatment was performed under the same operating conditions as in Example 1 except that the heat regeneration treatment of the filter was stopped. In this case, since the differential pressure of the filter doubled after about 100 hours of operation, the operation of the diesel engine exhaust gas dust collection system was stopped.

From the above test results, it can be understood that the present invention has extremely high practicality for the dust collection treatment of the exhaust gas of the ship main engine 2-stroke diesel engine using C heavy oil as fuel.

100 Diesel engine Exhaust gas dust collection system 101 Diesel engine 102 Inlet three-way valve 103a, 103b Exhaust gas introduction valve 104a, 104b Regeneration gas introduction valve 105 Heater 106 Air tank 107a, 107b Backwash valve 110 Ceramic filter type dust collector 112 Can body 114a, 114b Ceramic filters 115a, 115b Exhaust gas / regeneration gas inlet 117 Exhaust gas outlet 118 PM recovery box 119a, 119b Backwash gas inlet 121 Exhaust gas duct 122 Bypass duct 124 Exhaust gas duct 125 Circulation duct 126 Backwash gas pipe 127 Outside air duct 128 Outside air intake port 129a, 129b Valve 130 Exhaust fan 131 Regeneration fan 200 Diesel engine Exhaust gas dust collection system 201 2-stroke diesel engine 202 Inlet three-way valve 203a, 203b, 203c Exhaust gas introduction valve 204a, 204b, 204c Regeneration gas introduction valve 210a, 210b, 210c Ceramic Filter type dust collector 205 Heater 206 Air tank 207a, 207b, 207c Backwash valve 210a, 210b, 210c Ceramic filter type dust collector 214a, 214b, 214c Ceramic filter 215a, 215b, 215c Exhaust gas / regeneration gas inlet 217a, 217b, 217c Exhaust gas Outlets 219a, 219b, 219c Backwash gas inlet 220 4-stroke diesel engine 221 Exhaust gas duct 222 Bypass duct 223 Exhaust gas duct 224 Exhaust gas duct 225 Circulation duct 226 Backwash gas pipe 227 Outside air duct 228 Outside air intake port 229a, 229b Valve 230 Exhaust fan 231 Regeneration fan 400 Columnar ceramic filter 401 First cell 402 Second cell 404 Particle substance 406 Cleaning gas

Claims (19)

C The ceramic filter with particulate matter and oil in the exhaust gas of a 2-stroke diesel engine used as a main engine for ships using heavy oil as fuel is backwashed with high-pressure gas to form particles. The step A of removing substances from the ceramic filter and the exhaust gas of the 4-stroke diesel engine used as an auxiliary engine pass through the ceramic filter to heat the ceramic filter to 300 ° C. to 500 ° C. from the ceramic filter. A method for regenerating a ceramic filter for diesel engine exhaust gas, which includes step B for volatilizing and removing oil. The regeneration method according to claim 1, wherein the 4-stroke diesel engine uses C heavy oil as fuel . The regeneration method according to claim 1 or 2, wherein step B comprises heating the ceramic filter to 350 ° C. or higher. The regeneration method according to any one of claims 1 to 3, wherein the exhaust gas after dust collection discharged from the outlet of the diesel engine exhaust gas dust collector is used as a heat source in step B. The regeneration method according to any one of claims 1 to 4, wherein the oil content in the exhaust gas of the 4-stroke diesel engine is 5 mg / Nm ³ or less . The regeneration method according to any one of claims 1 to 5, wherein step B includes passing the gas heated by the heater through the ceramic filter. It is a method of treating diesel engine exhaust gas using two or more ceramic filters.
The two or more ceramic filters are configured to be able to introduce the exhaust gas of a common 2-stroke diesel engine fueled by heavy fuel oil C used as a main engine for ships .
While the regeneration method according to any one of claims 1 to 6 is being carried out for at least one ceramic filter among the two or more ceramic filters, at least one of the ceramic filters carrying out the regeneration method. A method for treating diesel engine exhaust gas, which comprises treating the exhaust gas with at least one ceramic filter different from the ceramic filter. The two or more ceramic filters are configured to be able to introduce gas heated by a common heater.
A claim including carrying out step B by introducing a gas heated by the heater into the at least one system of ceramic filters carrying out the regeneration method according to any one of claims 1 to 6. Item 7. The method for treating diesel engine exhaust gas according to Item 7. The method for treating diesel engine exhaust gas according to claim 7 or 8, wherein one or two or more dust collectors containing two or more ceramic filters are used. The method for treating diesel engine exhaust gas according to any one of claims 7 to 9, wherein two or more dust collectors containing one system of ceramic filters are used. A diesel engine exhaust gas dust collection system that uses two or more ceramic filters.
The two or more ceramic filters are configured to be able to introduce the exhaust gas of a common 2-stroke diesel engine fueled by heavy fuel oil C used as a main engine for ships .
While the regeneration method according to any one of claims 1 to 6 is being carried out for at least one ceramic filter among the two or more ceramic filters, at least one of the two or more ceramic filters carrying out the regeneration method. A diesel engine exhaust gas dust collection system configured to be capable of treating the exhaust gas with at least one ceramic filter different from the ceramic filter. The two or more ceramic filters are configured to be able to introduce gas heated by a common heater.
It is possible to carry out step B by introducing a gas heated by the heater into the at least one system of ceramic filters according to the regeneration method according to any one of claims 1 to 6. The diesel engine exhaust gas dust collecting system according to claim 11. The diesel engine exhaust gas dust collection system according to claim 11 or 12, wherein one or two or more dust collectors containing two or more ceramic filters are used. The diesel engine exhaust gas dust collection system according to any one of claims 11 to 13, wherein two or more dust collectors containing one ceramic filter are used. Diesel engine exhaust gas dust collection equipped with two or more ceramic filters, two or more exhaust gas introduction valves, two or more regeneration gas introduction valves, two or more backwash valves, and a backwash gas tank. It ’s a system,
The two or more systems of the ceramic filter are configured so that the exhaust gas of a common 2-stroke diesel engine using C heavy oil used as the main engine for ships can be introduced from the upstream side via the exhaust gas introduction valve of the corresponding system. Has been
The two or more ceramic filters are configured so that the exhaust gas of the 4-stroke diesel engine used as an auxiliary engine can be introduced from the upstream side via the regeneration gas introduction valve of the corresponding system.
The two or more ceramic filters are configured so that the backwash gas supplied from the backwash gas tank can be introduced from the downstream side via the backwash valve of the corresponding system.
Diesel engine exhaust gas dust collection system. 15 . The described diesel engine exhaust gas dust collection system. The diesel engine exhaust gas dust collection system according to claim 16 , further comprising a circulation duct for supplying the exhaust gas after dust collection discharged from the downstream side of the two or more ceramic filters to the heater . The diesel engine exhaust gas dust collection system according to any one of claims 15 to 17, wherein one or two or more dust collectors containing two or more ceramic filters are used. The diesel engine exhaust gas dust collection system according to any one of claims 15 to 18, wherein two or more dust collectors containing one ceramic filter are used.

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