JP3283795B2 - Regeneration method and apparatus for exhaust gas purification system for diesel engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of regenerating a purification treatment apparatus for removing oil such as unburned fuel and lubricating oil contained in exhaust gas mainly in a marine diesel engine and a regenerating apparatus therefor. The present invention relates to an exhaust gas purification processing device provided. The present invention is directed to an exhaust gas purifying apparatus using an oxidation catalyst.

[0002]

2. Description of the Related Art As this type of exhaust gas purification device, for example,
There is an apparatus described in JP-A-60-36709. In this device, a cylindrical casing is connected to the other end of an exhaust pipe one end of which is connected to a diesel engine, and the platinum catalyst provided in the casing allows the exhaust gas from the diesel engine to pass therethrough. At the same time as CO and HC are oxidized, carbon and oil mist adhering to the carrier layer carrying the platinum catalyst are combusted by the heat generated at that time and the heat of the exhaust gas.

Another prior art is disclosed in Japanese Patent Publication No. 62-26818.
There is a method for regenerating a denitration catalyst described in Japanese Patent Application Laid-Open Publication No. H11-209,878. This method
In a method of removing and regenerating hydrocarbon substances attached and deposited on a solid denitration catalyst, it is attempted to burn and regenerate the hydrocarbon substances by flowing a heated gas heated to 450 ° C. to 550 ° C. through a packed bed. Is what you do.

[0004]

However, the exhaust gas purifying apparatus and the method of regenerating the same described in the above-mentioned publications include:
There are issues to be improved in the following points. That is, in the former device, high-boiling components such as lubricating oil in the oil collected in the carrier layer are not easily oxidized, and thus gradually adhere to and accumulate on the surface of the carrier layer (oxidation catalyst) over time. Is done. As a result, the oxidation catalyst deteriorates, and in particular, the ability to oxidize and purify hydrocarbons decreases.
Regeneration of the oxidation catalyst is required.

[0005] In the latter method, a high-temperature heated gas is supplied to the catalyst, so that the catalyst may be more damaged, such as heat of combustion, and the life of the catalyst is shortened. Therefore, the catalyst must be replaced in a short time. And running costs increase.

The present invention has been made in view of the above points, and in an exhaust gas purification apparatus using an oxidation catalyst, the oxidation catalyst is hardly deteriorated, and when it is deteriorated, it is easily and immediately regenerated, and the exhaust gas from the diesel engine is exhausted. A method for regenerating an oxidation catalyst of an exhaust gas purification system capable of removing oil components such as unburned fuel and lubricating oil contained in gas for a long period of time and an exhaust gas purification system equipped with the regeneration system It is intended to provide.

[0007]

In order to achieve the above object, the present invention provides a method for regenerating an exhaust gas purifying apparatus, comprising the steps of: a) providing an oxidation catalyst in the middle of an exhaust gas passage discharged from a diesel engine; A method for regenerating an exhaust purification treatment apparatus for removing unburned fuel, lubricating oil, carbon and oil mist of high boiling point oil contained in exhaust gas by b)
Measure the pressure loss of the oxidation catalyst by measuring the pressure loss of the oxidation catalyst.
Oxidation of low-boiling fuel, such as light oil or kerosene , by introducing it in a vaporized state according to the specified pressure loss value
Carbon and high boiling water adsorbed on the catalyst surface
It promotes the oxidation of oil mist and the like of the point oil to regenerate the oxidation catalyst.

According to the regeneration method of the present invention having the above-described structure, when carbon or oil mist of a high-boiling oil adheres to the surface of the oxidation catalyst and the need to regenerate the oxidation catalyst arises, By introducing the vaporized state (for example, kerosene or light oil) upstream of the oxidation catalyst, the vaporized low-boiling fuel comes into contact with the oxidation catalyst to cause an oxidation reaction. Oxidation of carbon and high-boiling oil mist adsorbed on the catalyst surface is promoted by the oxidation of the low-boiling fuel, the ventilation resistance of the catalyst tank is reduced, and the contact between the exhaust gas and the catalyst is improved, The catalyst is activated. In addition, the present invention
According to the regeneration method, the pressure loss between the inlet and outlet of the oxidation catalyst is measured.
However, this increase in pressure loss is not
Oil mistake of carbon and high boiling oil adhering to the surface of the medium
Means that the number of catalysts increases,
The time required for regeneration is detected. Therefore,
Use low-boiling fuels for oxidation catalysts when catalyst regeneration is required.
As it can be introduced reliably, low-boiling fuel can be used effectively.
It can be used to regenerate a medium.

[0009]

[0010]

[0011]

[0012]

[0013] To achieve the above object, an exhaust gas purifying apparatus according to the present invention ( claim 2 ) comprises the following steps: A) providing an exhaust gas through an oxidation catalyst in an exhaust gas passage discharged from a diesel engine; Unburned fuel, lubricating oil and cars contained in
B) an exhaust gas purifying apparatus for removing oil mist or the like of high-boiling oil , B) connecting one end of a supply pipe for vaporized low-boiling fuel upstream of the oxidation catalyst in the exhaust gas passage, and connecting the other end of the supply pipe A low-boiling-point fuel discharge pump and a low-boiling-point fuel carburetor are interposed on the side, a carrier gas source is connected to the intake port of the carburetor, and a low-boiling-point fuel tank is connected to the fuel vaporizing section of the carburetor. C) light via the carrier gas
It is configured to vaporize a low-boiling fuel such as oil or kerosene and discharge the vaporized low-boiling fuel to the oxidation catalyst.

According to the exhaust gas purifying apparatus of the present invention having the above configuration, the low boiling point fuel in the tank is supplied to the vaporizing section of the vaporizer and vaporized by the carrier gas, and is discharged by the discharge force of the discharge pump. The vaporized low-boiling fuel is introduced upstream of the oxidation catalyst. As a result, the oxidation catalyst is regenerated by the same operation as the regenerating method according to claim 1 described above.

According to a third aspect of the present invention, D) a pressure drop gauge is provided between the upstream side and the downstream side of the oxidation catalyst, and the driving of the discharge pump is controlled based on a value measured by the pressure drop meter. Like that.

According to the apparatus of the third aspect , the low-boiling fuel is effectively used for the regeneration of the catalyst by the same operation as the regeneration method of the first aspect .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an exhaust gas purifying apparatus and a method of regenerating the same according to the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing an apparatus for purifying exhaust gas discharged from a diesel engine, FIG. 2 is a system diagram showing an embodiment of a device for vaporizing and supplying a low-boiling fuel, and FIG. It is a graph showing the regeneration effect of the catalyst, in which the vertical axis indicates the ratio of the hydrocarbons on the outlet side / the hydrocarbons on the inlet side, and the horizontal axis indicates the test time.

As shown in FIG. 1, a purification test apparatus 1 includes a thermostat (oven) 2 and an exhaust pipe B of a diesel engine A.
Is connected to one end of the branch pipe 3. In the thermostat 2,
A catalyst tank 4 filled with a platinum catalyst as an oxidation catalyst is housed in a cartridge, and the other end of the branch pipe 3 is connected to an inlet (upstream end) of the catalyst tank 4. One end of a suction pipe 5 is connected to an outlet (downstream end) of the catalyst tank 4, and the other end is connected to a suction unit 6 installed outside the thermostatic bath 2. The suction unit 6 includes a filter 6a and a suction pump 6 from the upstream side.
b, the flow meter 6c is connected in this order, and the downstream end of the suction unit 6 is formed at the exhaust port 6d.

One end of a supply pipe 8 of a vaporized fuel supply device 7 is connected between the branch pipe 3 and the inlet of the catalyst tank 4. The supply device 7 includes a vaporizer 9 as shown in FIG. The vaporizer 9 has a built-in light core 9a, and one end of a low-boiling-point fuel supply pipe 10 is connected to the light core 9a. A low-boiling fuel tank 11 is connected to the other end of the supply pipe 10, and a supply pump 12 is provided on the way. The supply device 7 also has a built-in heater 7b, which heats the low boiling point fuel supplied to the light core 9a to facilitate vaporization. In order to promote the vaporization of the low boiling point fuel, one end of the carrier gas supply pipe 13 is connected to the intake port 9c of the vaporizer 9, and the carrier gas tank 14 is connected to the other end. In the middle of the supply pipe 13, a constant pressure valve 15, a flow meter 16 and a fixed quantity valve 17 are provided.
Are interposed respectively. Further, the supply pipe 8 is connected to a discharge port 9 d of the vaporizer 9, and a discharge pump 18 is interposed in the supply pipe 8.

In the apparatus of the above-described embodiment, a test was conducted by using kerosene, light oil, propylene as the low boiling point fuel, and heavy fuel oil A same as the fuel of the diesel engine A. Although nitrogen gas was used as the carrier gas, air may be used. In the test, 30 l / min of exhaust gas was sucked from the exhaust pipe B of the diesel engine A by the suction unit 6, and the temperature in the constant temperature bath 2 was kept at 250 ° C. to evaporate the low boiling fuel in the vaporized state at the space velocity Sv = 5000. It was circulated through the catalyst tank 4.

After the kerosene is vaporized and continuously supplied from the supply device 7 to the catalyst tank 4 for a certain period of time, it is switched to light oil to be vaporized and continuously supplied to the catalyst tank 4 for a predetermined period of time, and finally switched to heavy fuel oil A. When the gas is vaporized and continuously supplied to the catalyst tank 4, the purifying action of the catalyst tank 4 is examined by measuring the total amount of HC (hydrocarbon) in the exhaust gas discharged from the outlet of the catalyst tank 4. Was. Switch to Fuel Oil A for a while (30
After about a minute), it was confirmed that the amount of discharge of the hydrocarbon continued to increase gradually, and the catalyst tank 4 was deteriorated. Fuel oil A is adsorbed on the surface of the catalyst tank 4, but is not easily oxidized, so that it is gradually coated and deteriorates the catalyst tank 4.

Therefore, in this test, when propylene (in a gaseous state at room temperature) was continuously supplied from the supply device 7 to the catalyst tank 4, it was oxidized and adsorbed by contact with the catalyst.
The heavy oil was oxidized to activate the catalyst, and as shown in FIG. 3, the ratio of HC in the exhaust gas on the catalyst outlet side / HC in the exhaust gas on the catalyst inlet side decreased, and the catalyst was regenerated. Thereafter, when heavy fuel oil A was vaporized in place of propylene and supplied to the catalyst tank 4, deterioration started again.

As described above, the regenerating effect by supplying the low-boiling fuel to the oxidation catalyst was confirmed. As shown in FIG. 1, the oxidation catalyst (platinum catalyst or palladium catalyst) was placed in the exhaust pipe B of the diesel engine A. A catalyst 21). Then, one end of the supply pipe 8 of the supply device 7 is connected to the oxidation catalyst 2.
1 near the inlet (upstream end). In addition, oxidation catalyst 2
1 is provided with a pressure loss meter 22 for measuring a pressure loss between the inlet side and the outlet side, and the operation of the discharge pump 18 (see FIG. 2) is started in a state where the value measured by the pressure loss meter 22 exceeds a predetermined value. Control circuit 23 is connected. As a low-boiling fuel,
For example, kerosene is used. In this way, each time the pressure loss value reaches a predetermined value, the low-boiling fuel is vaporized and the oxidation catalyst 2 is removed.
1 was introduced at the inlet to promote oxidation and to prevent deterioration of the oxidation catalyst 2 at all times. In this example, the test device 1
Is not provided because the exhaust gas temperature is relatively high and may be close to 500 ° C.

Although one embodiment of the present invention has been described above, the present invention can be implemented as follows. In other words, a quantitative meter for HC or SO _X is provided in place of the pressure drop meter 22, and when a predetermined value is reached, the vaporized low-boiling fuel is discharged to the oxidation catalyst 21 or a fixed timer is provided by providing a timer. It can be discharged every time.

[0026]

As is apparent from the above description, the regeneration method of the exhaust gas purifying apparatus for a diesel engine and the apparatus according to the present invention have the following excellent effects.

(1) According to the regenerating method of the present invention, even when carbon or high-boiling oil mist adheres to the surface of the oxidation catalyst to deteriorate the oxidation catalyst, the vaporized low-boiling fuel is oxidized. Since it comes into contact with the catalyst and causes an oxidation reaction, the oxidation of carbon mist and oil mist of high boiling point oil adsorbed on the surface is promoted, and the catalyst can be activated. Therefore, the oxidation catalyst is hardly deteriorated, and oil components such as unburned fuel and lubricating oil contained in the exhaust gas from the diesel engine can be efficiently removed for a long period of time.

(2) Further , the time when the regeneration of the catalyst is necessary is detected based on the pressure loss between the inlet and the outlet of the oxidation catalyst, and the low-boiling fuel can be accurately introduced into the oxidation catalyst. Used effectively for playback.

[0029]

( 3 ) Exhaust gas purification treatment device (Claim 2 )
With a simple structure, a low-boiling fuel vaporized via a carrier gas can be introduced upstream of the oxidation catalyst, and the oxidation catalyst can be effectively regenerated in the same manner as the regeneration method according to the first aspect.

( 4 ) The device according to claim 3 can effectively use a low-boiling-point fuel for the regeneration of the catalyst by the same operation as the regeneration method according to claim 1 .

[Brief description of the drawings]

FIG. 1 is a system diagram showing a test apparatus for purifying exhaust gas discharged from a diesel engine according to an embodiment of the present invention.

FIG. 2 is a system diagram showing an embodiment of an apparatus for vaporizing and supplying a low boiling point fuel.

FIG. 3 is a graph showing a regeneration effect of an oxidation catalyst by a low-boiling fuel, in which a vertical axis indicates a ratio of an outlet-side hydrocarbon substance / an inlet-side hydrocarbon substance, and a horizontal axis indicates a test time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Purification test apparatus 2 Constant temperature oven (oven) 3 Branch pipe 4 Catalyst tank 5 Suction pipe 6 Suction unit 7 Supply apparatus of vaporized fuel 8.10 Supply pipe 9 Vaporizer 11 Low boiling point fuel tank 12 Supply pump 13 Carrier gas supply pipe 14 Carrier gas tank 18 Discharge pump 21 Oxidation catalyst 22 Pressure drop gauge A Diesel engine B Exhaust pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 21/00-38/74 B01D 53 / 86,53 / 94 F01N 3/20 F01N 3/36

Claims (3)

(57) [Claims] 1. An exhaust gas passage for exhausting unburned fuel, lubricating oil , carbon and high-boiling oil contained in exhaust gas through an oxidation catalyst in the middle of an exhaust gas passage discharged from a diesel engine.
A method for regenerating an exhaust purification treatment apparatus for removing a gas or the like, the method comprising measuring pressure loss of the oxidation catalyst with respect to the oxidation catalyst.
Oxidation of low-boiling fuel, such as light oil or kerosene , by introducing it in a vaporized state according to the specified pressure loss value
Carbon and high boiling water adsorbed on the catalyst surface
A method for regenerating an exhaust gas purification treatment device for a diesel engine , comprising promoting the oxidation of oil mist or the like of a point oil to regenerate the oxidation catalyst. 2. An oil catalyst containing unburned fuel, lubricating oil, carbon and high-boiling oil contained in exhaust gas through an oxidation catalyst interposed in an exhaust gas passage discharged from a diesel engine.
In an exhaust gas purifying apparatus for removing a gaseous exhaust gas, an end of a supply pipe for vaporized low-boiling fuel is connected to the exhaust gas passage upstream of the oxidation catalyst, and a discharge pump for vaporized low-boiling fuel is connected to the other end of the supply pipe. , A low-boiling fuel vaporizer is interposed, and a carrier gas source is connected to the intake port of the vaporizer,
Further, a low-boiling fuel tank is connected to a fuel vaporizing section of the carburetor, the low-boiling fuel such as light oil or kerosene is vaporized through the carrier gas, and the vaporized low-boiling fuel is discharged to the oxidation catalyst. An exhaust gas purification treatment device for a diesel engine, characterized in that: 3. The diesel engine according to claim 2 , wherein a pressure loss meter is provided between an upstream side and a downstream side of the oxidation catalyst, and the driving of the discharge pump is controlled based on a value measured by the pressure loss meter. Engine exhaust purification system.