KR20070000043A - Filter for eliminating particulate matters in a diesel engine - Google Patents

Abstract

A filter device for eliminating particulate matters from a diesel engine is provided to improve particulate matter collecting efficiency by preventing the thickness of the filter from being thickened and increasing the length of the exhaust gas flow channel. A filter device comprises a can, a filter assembly, and a plurality of partitions. The can has an inlet port for inflow of exhaust gas emitted from an engine, and an outlet port for discharging exhaust gas passed through a filter. The filter assembly is arranged in the can, and mounted with a stacked or rolled type metallic foam filter(31) for passage of introduced exhaust gas. The partitions are arranged in the can so as to modify the exhaust gas flow channel for passage and emission of exhaust gas introduced through the inlet port.

Description

Filter device for removing particulate matter from diesel engines {Filter for eliminating particulate matters in a diesel engine}

The present invention relates to a filter device for removing particulate matter of a diesel engine, and more particularly, in the case of replacing a diesel particulate filter (DPF) made of a conventional ceramic with a metal, the pore of a metal foam. The size is 200-1000㎛ and coarse than the ceramic filter having an average pore size of 30㎛ has a problem that the collection efficiency is lowered, in order to improve the filter shape and arrangement design that can increase the collection efficiency while reducing the back pressure is important However, in order to increase the collection efficiency of particulate matter, the thickness of the filter must be thick. Another problem arises in that the back pressure rapidly increases when the thickness is increased. One or several partitions It is possible to increase the collection efficiency of particulate matter by passing through several layers of filters to increase the length of the exhaust gas path without increasing the thickness of the filter by using a single filter, and the partition in one filter ass'y It can be divided into many filter parts, and it can be installed in one filter ass'y by treating various catalysts by parts, and can remove various gases from exhaust gas, and metal foam filter can be stacked or rolled up. The present invention relates to a filter device for removing particulate matter of a diesel engine, which can improve collection efficiency by forming an inward method or an outward method of an exhaust gas flow path.

In general, the exhaust gas of a vehicle refers to a gas in which a mixture combusted from an engine is released into the atmosphere through an exhaust pipe, and the exhaust gas mainly includes harmful substances such as carbon monoxide (CO), nitrogen oxides (NOx), and unburned hydrocarbons (HC). This is included. Such exhaust gas regulation is inevitably tightened. Accordingly, an exhaust gas control device including an exhaust gas recirculation device, a three-way catalyst, an MPI device, and an evaporative gas control device including a canister, a purge control solenoid valve, etc. The back is applied to a vehicle.

On the other hand, although diesel engine vehicles are excellent in fuel economy and power output, unlike gasoline engines, nitrogen gas and particulate matter (PM) are significantly contained in exhaust gas. In diesel vehicles, CO and HC are emitted much less than gasoline vehicles because the air is combusted in most operating conditions, but NOx and particulate matter (soot) are emitted.

Therefore, the main targets of diesel vehicle emission regulation are NOx and particulate matter (PM). As a countermeasure technique, the delay of fuel injection time and the concentration of NOx by Exhaust Gas Recirculation As a technique for reducing and improving the combustion performance of an engine for reducing particulate matter, the trend is being developed with an emphasis on the technology. In other words, as a concrete countermeasure for diesel vehicle exhaust regulation, engine improvement and after-treatment technology are classified into diesel engines. First, engine improvement technology of diesel vehicles is improved fuel chamber, intake system (turbocharger + intercooler), and fuel injection system ( Electronically controlled high pressure fuel injection devices) and exhaust gas recirculation devices are being applied or under development. In addition, as a post-treatment technique, firstly, an oxidation catalyst for purifying high-boiling hydrocarbons in particulate matter (PM), secondly, a DeNOx catalyst which decomposes or reduces nitrogen oxides (NOx) in an excess oxygen atmosphere, and thirdly, particulate matter (PM). Diesel Particulate Filter (DPF) system. However, the particulate filter (PM) removal filter system of the post-treatment technology has the advantage of reducing the emissions by reliably capture soot, but the back pressure of the exhaust gas increases due to the increase of particulate matter trapped in the DPF over time There is a problem that the burden on the engine becomes large.

For this reason, the regeneration method of burning and removing the particulate matter collected by the reduction of the back pressure of the DPF itself is an important factor that determines the performance of the DPF.

Currently, as the material of the DPF, silicon carbide (SiC) attracts attention due to problems such as thermal expansion and durability at the time of regeneration by combustion of the collected particulate matter, as shown in FIGS. 1 and 2. The unit cell 110 is made of silicon, and the unit cell 110 is bonded with an adhesive similar to that of silicon carbide to manufacture a DPF 100 having a desired size. At present, the DPF 100 is configured of a unit cell 110 having the same cell density and porosity of the unit cell 110 to manufacture a DPF 100 having a desired size. The DPF 100 having a density and porosity has a larger DPF (100) than the diameter of the exhaust gas exhaust pipe because the size of the DPF 100 is determined based on particulate matter discharge to collect particulate matter discharged from the engine. ) Or a DPF 100 having the same diameter as the exhaust pipe, the DPF 100 having a very long length is installed, so that the back pressure of the exhaust gas is very high, so that the operation of the engine is impossible. Therefore, it is inevitable to install the DPF 100 larger than the diameter of the exhaust pipe in order to remove particulate matter while suppressing the increase in the discharge pressure with respect to the exhaust gas of the diesel engine. As a result, a phenomenon in which the flow of exhaust gas is concentrated only at the center portion of the DPF 100 occurs, and particulate matter collected at the edge thereof is not smoothly flowed during the regeneration mode due to the rise of the exhaust gas temperature. At some point, there is a problem in that the exhaust gas passage area of the DPF 100 is reduced by the loss of function, thereby increasing the exhaust gas pressure of the engine, thereby providing a cause of engine failure.

In addition, when regeneration occurs in a state where excessive particulate matter is collected, there is a problem in that the DPF 100 is damaged due to a sudden temperature rise.

Meanwhile, the material of the conventional diesel particulate filter (DPF) is a ceramic made of cordierite or silicon carbide (SiC), which is brittle and easily damaged by a weak impact, thus producing a process design. In the mass production design, special care is required and productivity is low due to poor assembly. In addition, ceramics have very poor thermal conductivity, which prevents rapid release of heat generated when particulate matter is regenerated to the outside, causing a sharp increase in local temperature, which causes the ceramic filter to melt itself or concentrate heat, resulting in a coefficient of thermal expansion with the surroundings. It may be broken by the difference. However, in the case of the metal filter, due to the superior ductility characteristics of the ceramic, there is less damage due to impact, higher assembly and productivity, and superior thermal conductivity than the ceramic, thereby rapidly transferring local heat generated during regeneration. Although there is little damage due to localized heat concentration or a difference in coefficient of thermal expansion, the pore size of the metal foam is 200 to 1000 μm and coarse than that of a ceramic filter having an average pore size of 30 μm.

Accordingly, the present invention has been conceived to solve the above problems, when replacing the conventional diesel particulate filter (DPF) made of ceramic with a metal, the pore size of the metal foam is 200 to 1000㎛ It is coarse than the ceramic filter having an average pore size of 30 μm, which lowers the collection efficiency. To improve this problem, it is important to design a filter shape and a batch design that can reduce the back pressure and increase the collection efficiency. To increase the thickness, the thickness of the filter must be thick, but another problem arises in that the back pressure increases rapidly when the thickness is increased. To improve this, the structure and arrangement for increasing the collection efficiency while taking the thickness of the filter thin are important. You can use one or several dividers to In the thickened length of the flow path of the exhaust gas even if the take is to pass through the multiple layers of filter able to provide increased particulate removal filter for a diesel engine to improve the collection efficiency of the particulate matter it is an object.

In addition, another object of the present invention can be divided by a plurality of filter parts due to the partition in one filter ass'y can be installed in one filter ass'y by treating a variety of catalysts for each site various gases from the exhaust gas It is to provide a filter device for removing particulate matter of a diesel engine that can remove.

In addition, another object of the present invention is to provide a filter device for removing particulate matter of a diesel engine that can improve the collection efficiency by forming a metal foam filter in a stacked type or rolling method and by forming an inward type or an outward type of the flow path of the exhaust gas. To provide.

Another object of the present invention is to provide a filter device for removing particulate matter of a diesel engine that can improve the flow of exhaust gas entering the inlet port by fastening a conical lid to the upper end of the filter ass'y.

In order to achieve the above object, a filter device for removing particulate matter of a diesel engine according to a preferred embodiment of the present invention includes an inlet port through which exhaust gas combusted from an engine is introduced, and an outlet port through which the exhaust gas is passed through a filter. Cans; A filter assay mounted inside the can and equipped with a stacked or rolled metal foam filter through which the introduced exhaust gas passes; One or more partitions formed inside the can to change an exhaust gas flow path through which the exhaust gas introduced into the inlet passes through the metal filter and is discharged to the outlet; Characterized by including.

In the present invention, the flow path of the exhaust gas enters inside the filter ass'y, passes through the filter ass'y and exits to the outside, and the outward method or the exhaust gas flowing back into the filter flows outside the filter ass'y. It includes an inward way through the ass'y, into the filter ass'y, into the outside and back out of the can.

In the present invention, it can be divided by a plurality of filter parts due to partitions in the one filter ass'y can be installed in one filter ass'y by treating a variety of catalysts for each part, various gases coming out of the exhaust gas Characterized in that it can be removed.

In the present invention, it characterized in that it further comprises a conical lid fastening to the upper end of the filter ass'y to improve the flow of the exhaust gas entering the inlet.

Hereinafter, with reference to the accompanying drawings, a filter for an exhaust gas purifying apparatus of a diesel engine according to a preferred embodiment of the present invention will be described in detail.

Figure 3 is a perspective view showing the shape of the metal foam filter of the laminated type constituting the filter ass'y in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention, Figure 4 is an embodiment of the present invention Fig. 5 is a perspective view showing the shape of a rolling metal foam filter constituting the filter ass'y in the filter device for removing particulate matter of a diesel engine according to the present invention, and FIG. 5 is for removing particulate matter of a diesel engine according to an embodiment of the present invention. 6 is a cross-sectional view illustrating a filter device in which an exhaust gas flow path having one partition in the filter device is formed in an outward manner, and FIG. 6 has one partition in the filter device for removing particulate matter of a diesel engine according to an embodiment of the present invention. It is sectional drawing which shows the filter apparatus in which the flow path of exhaust gas was formed inward.

As shown in FIGS. 3 to 6, the filter device 60 for removing particulate matter of a diesel engine includes an inlet 11 through which exhaust gas combusted from an engine flows in, and the exhaust gas passes through a filter. A can 10 in which an outlet 12 is formed; A filter assay (30) mounted in the can and equipped with a laminated or rolled metal foam filter through which the inflowed exhaust gas passes; exhaust gas formed in the can and introduced into the inlet And one or a plurality of partitions 20 for changing the flow path 40 of the exhaust gas through which the gas passes through the metal filter to the discharge port.

Looking at the function of the main technical means of the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention with reference to the bar shown in Figures 3 to 6 as follows.

The can 10 includes an inlet 11 through which exhaust gas combusted from an engine flows in, and an outlet 12 through which the exhaust gas passes through a filter.

The partition 20 is mounted inside the can to prevent exhaust gas flowing into the inlet from being discharged without passing through the filter. The partition 20 is one or more according to the flow path characteristics and the use environment. You can put multiple dogs. Therefore, the initial effective contact area can be increased to reduce the back pressure, and the collection gas can be improved by increasing the length of the exhaust gas passing through the metal filter. In addition, due to the number of partitions in one filter ass'y (30) can be divided into a number of filter parts can be installed in one filter ass'y (30) by treating a variety of catalysts for each part to come out of the exhaust gas Various gases can be removed.

The plurality of metal filters ass'y 30 is vertically stacked and mounted in order to increase the effective contact area between the one or more partitions and to increase the length of the exhaust gas passing through a given space. As shown in FIGS. 3 and 4, the metal foam filter formed in the metal filter ass'y 30 may have a stacking method or a rolling method. The stacking method may include a through hole 32 in the center of a nickel foam. ) And the pressurized canning of the buried layer by a pressing method, and the rolling type shows a structure in which nickel alloy foam is rolled around the holder 33. The porosity of the surface and the side of the conventional metal alloy is almost the same, but the pore size of the side is 50% of the porosity of the surface, so that the pores are small and the porosity can increase the collection efficiency. Surface porosity of the metal alloy is 400 to 700㎛, side pore is 100 to 300㎛, porosity is 86% ± 5%. In addition, the metal filter 30 is alloyed by adding chromium and iron to the Ni base. In addition, the conical lid is fastened to the upper end of the metal filter ass'y 30 to improve the flow of the exhaust gas entering the inlet 11.

The flow path 40 is formed inside the can to allow the exhaust gas introduced into the inlet to pass through the metal filter to the outlet.

In addition, the flow path 40 of the exhaust gas enters the inside of the filter ass'y 30 as shown in FIG. 5, passes through the filter ass'y, exits to the outside, and enters the inside again. As shown in the drawing, the exhaust gas flows through the filter ass'y from the outside of the filter ass'y 30, enters the inside of the filter ass'y, and flows back into the outside to exit the can. In the outward method, the exhaust gas does not pass through the filter ass (30) by welding, cock'g, brazing, fastening with a bolt, and fitting the gap between the filter ass'y (30) and the can (10). It should be prevented from leaking, and the partition 20 should be supported by the filter ass'y 30 or supported by the can 10 to prevent the flow of exhaust gas. Also, inward method should be composed of welding, cock'g, brazing, fastening with bolts and tolerance fitting so that there are no leaks from the flow path to the other side, that is, no leakage at each part. The conical cap 50 at the front end of the filter ass'y 30 is used when the exhaust gas flows badly, but may not be used when the overall exhaust gas flows well. The partition 20 at the boundary of each filter portion may have a structure supported inside the filter ass'y 30 or the can 10 as shown in FIG. 5.

7 is a perspective view illustrating a flow pattern of exhaust gas in a radial type metal foam diesel particulate filter (DPF) in the particulate matter removing filter device of a diesel engine according to an embodiment of the present invention, and FIG. In the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention is a view showing the difference in pressure drop over time between flow methods, Figure 9 is for removing particulate matter of the diesel engine according to an embodiment of the present invention 10 is a view showing a change in the collection efficiency of the filter for each particle diameter as the collection process between the flow method in the filter device, Figure 10 is a filter device for removing particulate matter in the diesel engine according to an embodiment of the present invention It is a figure which shows the change of the particle density distribution between flow systems. In addition, Figure 11 is a view showing the total collection efficiency of the filter between the flow in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention, Figure 12 is a particulate form of the diesel engine according to an embodiment of the present invention FIG. 13 is a view illustrating a distribution of masses of soot collected in a filter as a collection process between flow types is performed in a filter for removing substances, and FIG. 13 is a filter device for removing particulate matter from a diesel engine according to an embodiment of the present invention. In Figure 15 is a view showing the change in mass distribution in the filter according to the time and the foam thickness in the plane cut to the length of 15cm, which is half the length of the filter in the axial direction, Figure 14 is a particulate form of a diesel engine according to an embodiment of the present invention In the filter device for removing substances, the thickness of the soot layer growing on the surface of the exhaust gas inlet surface is shown as the collection process between the flow modes proceeds.

7 to 14 are flow and capture process analysis according to the flow direction of the radial type metallic foam DPF, flow and capture process of the radial type metallic foam DPF increased initial exhaust gas inlet area compared to the axial type metallic foam DPF A prediction technique was developed and applied to the prediction of the effects of flow and capture processes according to flow direction changes in DPF

As shown in FIG. 7, an analysis target is a radial type metallic foam DPF, and the flow method in the DPF is an inward flow method and an inner surface flowing inward from the outer surface of the foam according to the direction in which the exhaust gas flows through the DPF. It can be distinguished by the outward flow method flowing outward from. The inward flow method has a relatively larger initial exhaust gas inflow area than the outflow flow method, so the concentration and flow rate of soot per area are small.

8 shows the influence of the flow method difference on the pressure drop, and a small diagram in the figure shows an enlarged pressure drop at the beginning of the collection process. In the early stage of the collection process, the inward flow method, which was expected to have a large pressure drop from the fluid flow point of view, was calculated somewhat higher than the outward flow method, but this trend was reversed as the collection process proceeded. This indicates that the pressure drop as the flow area is narrowed is smaller than the pressure drop generated as the collecting process proceeds. In addition, the outward flow method showed a larger change in pressure drop over time than the inward flow method.

9 is a diagram showing the change in the collection efficiency of the filter for each particle diameter as the collection process proceeds. In the early stage of the collection process (1 hr), the collection efficiency was similar for both methods. As the process progressed, the outward flow method was found to have a somewhat higher collection efficiency than the inward flow method for all particle sizes. However, in FIG. 10, which shows the decrease of soot particles as the collection process proceeds, the two methods were found to have no significant difference. Both the inward flow method and the outward flow method showed high particle capture performance when the particle diameter was less than 0.1mm, and the particle capture performance was deteriorated due to the low collection efficiency for particles with diameter larger than 0.1mm.

FIG. 11 shows the total collection efficiency of the filter. In the case of outward flow, the collection efficiency is not significantly different even though it causes a higher pressure drop than in the case of inward flow. The reason for this phenomenon is that in the outward flow method, the flow velocity through the foam at the exhaust gas inlet side is larger than that of the inward flow method. Also, the narrow inlet side increases the inlet mass of the soot, increasing the soot penetration length. I think because. Increasing the flow velocity at the inflow side results in low diffusion efficiency and increasing the penetration length results in an increase in the probability of particle passing through the filter.

12 shows the distribution of the mass of soot collected in the filter as the collecting process proceeds. In the case of the inward flow method, soot particles are collected from the upper surface into which the exhaust gas is introduced and gradually become inward as time passes. The soot penetrates and shows a high distribution on the upper side and a low distribution toward the inside. It can also be seen that most of the soot mass is concentrated on the upper surface. On the other hand, in the outward flow method, the soot particles are collected from the lower side where the exhaust gas flows and the soot penetrates outward as time passes and shows a high soot mass distribution on the lower side. This aspect is also shown in FIG. 13 which shows the change in mass distribution inside the filter over time in a plane in which the 15 cm half point of the filter length is cut perpendicular to the axial direction. In the figure, the coordinate of the surface into which the exhaust gas flows was set to x = 0. In the inward method, as the exhaust gas passes through the filter from the inlet side, a large part of the soot is collected at the inlet side, and the amount of soot mass collected increases over time, whereas the amount of soot introduced into the filter is large. As it decreases proportionally, the increase in trapped soot mass inside the filter decreases as it moves away from the inlet. In the outward method, the soot mass distribution was similar to that of the inward method, but the increase in soot mass collected on the inflow side was smaller than that of the inward method, and the increase in the soot mass collected near the discharge surface where the exhaust gas leaves the filter was inward. Larger than that. It is thought that this is because in the outward method, since the inflow area of the exhaust gas is smaller than that of the inward method, a significant amount of the soot introduced does not collect around the inlet surface but penetrates into the filter. The mass collected on the exhaust gas inlet is smaller than the inward flow method, but the inlet area is only half of the inward area, so the porosity and permeability of the slab forming the inlet is reduced, resulting in a relatively high pressure. It is considered to have shown a drop.

14 shows the change in the thickness of the soot layer growing on the surface of the exhaust gas inlet surface as the collection process proceeds, and the outward method showed a faster growth rate than the inward method. Therefore, the outward method, which has a rapid growth rate of the soot layer, has a thicker soot layer than the inward method.

Therefore, it can be seen from the result of the three-dimensional flow analysis that the back pressure is low and the collection efficiency of particulate matter (PM) is good.

As described above, various substitutions, modifications, and changes can be made by those skilled in the art without departing from the technical spirit of the present invention, and thus, the embodiments and the accompanying drawings are limited. It doesn't happen.

As described above, the filter for the exhaust gas purification device of the diesel engine according to the present invention has the following effects.

First, the present invention, when replacing the diesel particulate filter (DPF) made of conventional ceramics with a metal, the pore size of the metal foam is 200 to 1000 ㎛ with a pore size of 30 ㎛ on average It is coarse than the filter, and the collection efficiency is lowered. To improve this, the filter shape and the layout design which can increase the collection efficiency while reducing the back pressure are important, but the thickness of the filter must be thick to increase the collection efficiency of particulate matter. To increase the thickness, another problem arises in that the back pressure increases rapidly. To improve this problem, it is important to use a single or multiple partitions because the structure and arrangement are important to increase the collection efficiency while taking a thin thickness of the filter. Without taking the thickness of the filter thick Its length can be passed through multiple layers of filters to increase the collection efficiency of particulate matter.

Secondly, the present invention can be divided into a plurality of filter parts due to partitions in one filter ass'y, and can be installed in one filter ass'y by treating various catalysts for each part to remove various gases from the exhaust gas. can do.

Third, the present invention can improve the collection efficiency by forming a metal foam filter in a stacked type or rolling method and by forming an inward type or an outward type flow path of the exhaust gas.

Fourth, the present invention can improve the flow of the exhaust gas entering the inlet by fastening the conical lid to the upper end of the filter ass'y.

1 is a perspective view showing a filter system for removing particulate matter of a general diesel engine.

2 is a cross-sectional view showing a filter for removing particulate matter of a conventional diesel engine.

Figure 3 is a perspective view showing the shape of the metal foam filter of the laminated type constituting the filter ass'y in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

Figure 4 is a perspective view showing the shape of the rolling metal foam filter constituting the filter ass'y in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

Figure 5 is a cross-sectional view showing a filter device in which the flow path of the exhaust gas having one partition in the outward manner in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

Figure 6 is a cross-sectional view showing a filter device in which the flow path of the exhaust gas having one partition in the inward manner in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

Figure 7 is a perspective view showing the flow pattern of the exhaust gas in the radial type metal foam diesel particulate filter (DPF) in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

8 is a view showing the difference in pressure drop over time between flow modes in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

9 is a view showing a change in the collection efficiency of the filter for each particle diameter as the collection process between the flow type in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

10 is a view showing the change of the particle density distribution between the flow method in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

11 is a view showing the total collection efficiency of the filter between the flow mode in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

12 is a view showing the distribution of the mass of soot collected in the filter as the collection process between flow modes in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

13 is a change in mass distribution in the filter according to the time and foam thickness in the plane perpendicular to the axial direction cut 15cm of the length of the filter in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention The figure showing.

14 is a view showing a change in the thickness of the soot layer growing on the surface of the exhaust gas inlet as the collection process between the flow in the filter device for removing particulate matter of the diesel engine according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10 ... can 11 ... inlet

12 ... outlet 20 ... partition

30 ... filter ass'y 31 ... metal filter

32 ... Through hole 33 ... Holder

40 ... Euro 50 ... conical lid

       60 ... filter unit

Claims (4)

In the filter device for removing particulate matter of a diesel engine, An inlet through which exhaust gas combusted from the engine is introduced, A can having an outlet through which the exhaust gas passes through the filter; A filter assay mounted inside the can and equipped with a stacked or rolled metal foam filter through which the introduced exhaust gas passes; One or more partitions formed inside the can to change an exhaust gas flow path through which the exhaust gas introduced into the inlet passes through the metal filter and is discharged to the outlet; Filter device for removing particulate matter of the diesel engine comprising a. The method of claim 1, The flow path of the exhaust gas enters the filter ass'y, passes through the filter ass'y, and exits to the outside. Then, the outward method or the exhaust gas enters the inside and passes through the filter ass'y from the outside of the filter ass'y. A filter device for removing particulate matter from a diesel engine, comprising an inward method that flows into the filter ass'y and flows back outward to the outside of the can. The method of claim 1, The partitions in the one filter ass'y can be divided into a plurality of filter parts, and can be installed in one filter ass'y by treating various catalysts for each part to remove various gases from the exhaust gas. Filter device for removing particulate matter of the diesel engine comprising. The method according to any one of claims 1 to 3, Filter unit for removing particulate matter of the diesel engine, characterized in that further comprising fastening a conical lid to the upper end of the filter ass'y to improve the flow of the exhaust gas entering the inlet.