MXPA98006987A - Cartucho filter for gas calie - Google Patents

Abstract

A regenerable gas cartridge filter (20, 120) for filtering particles from a discharge gas includes a hollow tube (130) having a pierced portion and a portion at the open end (154). The pierced portion (130) has a diameter larger than the diameter of the open end portion (154). A filter element (132) is placed in the hollow tube (130) and the filter element (132) extends over the larger diameter of the perforated portion (130) and the smaller diameter of the open end portion (15).

Description

HOT GAS CARTRIDGE FILTER Background of the Invention This invention relates to filters for the removal of particles from gaseous streams and more particularly to an appropriate filter to improve the flow rate and the capacity of the pressure drop of a regenerable cartridge filter. While this application discloses the present invention within an exhaust filter frame of a diesel engine, the invention is readily adaptable to filter particles of other types of gas streams.

Diesel engines emit a dangerous soot discharge that can be less dangerous when using a diesel particulate filter. The filters trap the soot particles emitted by a motor and thereby prevent the particles from entering the atmosphere. However the soot trapped by REF .: 28136 such filters are concentrated over time. As the soot is concentrated in the filter, the filter efficiency decreases, an increase in the pressure drop occurs through the filter and the motor experiences an increase in the gas discharge which decreases the performance of the engine. Therefore, the clogged filter should be replaced or regenerated. Depending on the speed with which the filter is filled with soot particles, the replacement of the clogged filters is inconvenient and expensive. Therefore periodic regeneration of the filter (for example, removal of trapped soot) is the preferred method to maintain a clean filter.

There are several techniques to regenerate diesel particle filters. The methods typically involve igniting the soot particles trapped in the filter and thereby burning the soot out of the filter. One technique involves the periodic release of a combustion gas within the filter as disclosed in U.S. Patent No. 4,912,920 by Hirabashi. Another technique uses electric heating elements in contact with the filtering elements. An electrically regenerable filter is illustrated in US Patent No. 5,252,164 by Bloom et al. Even a third technique uses microwave energy to heat the filter and causes the particles trapped in the filter to ignite and burn, thereby regenerating the filter. A regenerable microwave filter is illustrated in U.S. Patent No. 5,453,116 by Fischer et al.

The filter assembly regenerated by ignition of the soot trapped with a combustion gas additive or an electric heating resistor typically uses metal structures to support the filter element or to provide a resistance to heating, while the filters are regenerated by ignition of trapped soot with microwave energy they typically use porous non-metallic structures to support the filter element. A perforated metal tube, a mesh, a wound cable or a similar structure are often used to provide support for a filter element. For example, U.S. Patent No. 5,258,164 by Bloom et al. discloses an electrically resistive expanded metal cover 21 positioned between an internal filter element 20 and an outer filter element 22 which is used to heat and thereby fill the filter elements 20, 22. The diesel discharge enters the interior of the structure of porous support and passes radially through the filter elements.

The use of a regenerable cartridge filter is limited by the flow rate and the pressure drop across the cartridge filter increases, the force exerted against the inside of the filter element increases. The increase in force frequently causes the filter element to expand or "swell" near the middle of the filter cartridge which has the effect of shortening the total length of the filter element can be exposed at its ends and the gas discharge allows Flow out of the cartridge filter without passing through the filter element. The resulting leak reduces cartridge performance.

There is thus a need for a regenerable cartridge filter which is effective as a filter resistant to failure due to "swelling" of the filter element and which is easily manufactured at a low cost.

BRIEF DESCRIPTION OF THE INVENTION The present invention is an apparatus and method for keeping a gas stream clean. The invention of a particulate filter comprises a longitudinal hollow tube having a pierced portion and an open part at the end. The open part at the end has a first outer diameter and the pierced portion has a second outer diameter. The first diameter of the open end is smaller than the second diameter of the pierced portion. A filter element is placed near the hollow tube and extends over the second diameter of the perforated portion and the first diameter of the open end.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of the diesel particle trap using the particle cartridge of the invention.

Fig. 2 is a sectional view of a prior art particle cartridge.

Fig. 3 is a top view of a particle cartridge with a "swollen" filter element.

Fig. 4 is a sectional view of a particle cartridge of the invention.

However, the previously identified drawings set out preferred embodiments, this disclosure presents illustrative embodiments of the present invention by means of representation and not limitation. It should be understood that numerous modifications and modalities can be -decided by a person skilled in the art which falls within the scope and expectation of the principles of this invention.

Detailed description of the invention The present invention provides an efficient cartridge filter suitable for regeneration (for example, burning the collected soot off). The present invention is particularly suitable for preventing "swelling" of the filter media of the particulate cartridge during use.

In the description of the present invention and the claims the following terms are intended to have the meaning defined below: "Inorganic fiber" refers to any inorganic base fiber which is resistant to high temperature (e.g. temperatures approximately greater than 600 ° C), is chemically resistant to diesel exhaust gas, and has textile qualities (e.g. it is suitable for forming into a yarn or fabric which can be made inside the support tube or can be wound or wrapped around the support tube); "tow" means a plurality or pile of individual fibers or filaments; "spinning" means a plurality or pile of individual fibers or filaments that have been twisted together; "continuous filament inorganic spinning" refers to any spinning of inorganic base which is resistant to high temperatures (e.g., temperatures approximately greater than 600 ° C) and which is long enough to wrap around the circumference of the tube of support at least once; preferably the continuous yarn is at least 25 cm long, more preferably, at least 1 meter long; Referring to Figure 1, a diesel particle trap 10 includes a cover 12 comprising a cylindrical body 14, an inlet of the discharge 16 and an outlet of the discharge 18. Within the cylindrical body 14 are a plurality of filter assemblies, from side to side, parallel 20, each of these is open adjacent to the inlet of the discharge 16 and blocked adjacent to the outlet 18. The filter assemblies 20 extend between a wall at the end 22 adjacent to the discharge inlet 16 and a wall at the end 24 adjacent to the discharge outlet 18. The filter assemblies 20 are connected to the end wall 22 and the end wall 24 by an open inner tube 26 and a closed lid at the end 28., respectively. The end wall 22 and the end wall 24 are connected by a cylindrical body 14 and help direct the discharge gas 29 through the fi assemblies 20. The end wall 22 blocks the spaces between the adjacent cartridge fi 20. such that the discharge gas (see arrows 29 in Figure 1) enters the inlet of the discharge 16 passes through the inlet of the open tube 26 and into the interior of the cartridge fi 20. The closed end cap 28 locks the end of the fi assemblies 20 adjacent the end wall 24 and forcing the discharge gas 29 to pass radially and externally through the cartridge fi 20 before exiting through the openings 32 in the end wall 24 adjacent to the the outlet of the discharge 18. In an anative embodiment, the discharge gas 29 can be directed such that the discharge gas 29 flows radially from the outside of the cartridge fi 20 to the interior of the cartridge fi 20 and then s alir of an open end of the cartridge fi 20.

A cartridge filter of the prior art 20 is shown in Figure 2. The cartridge filter 20 is assembled as a cartridge. A perforated support tube 30 extends between the inlet of the tube 26 and the closed cap of the end 28. A filter element 32 is placed on the support tube 30, in the entrance of the tube 26, and the cap of the end 28. cartridge filter 20 thus consists of the support tube 30, the open inlet of the tube 26, the closed end cap 28, and the filter element 32.

The filter element 32 can comprise several types of inorganic material. For example, inorganic spun can be substantially helically wrapped or wound interlaced over the support tube 30 to provide the filter element 32. Optionally, more than one type of filter material can be combined to form the filter element 32. For example, a nonwoven web it can be interposed between the support tube 30 and an inorganic yarn which is substantially wound helically or wound entangled over the non-woven mat and the support tube 30. Any other combination of filtering materials which produce the desired filtering development can be used. The inorganic material comprises the filter material 32 can for example be fiberglass or ceramics.

As seen in Figure 2, the filter element 32 extends over the perforated support tube 30 and over the inlet of the tube 26 and the end cap 28. The external diameters of the tube inlet 26 and the end cap 28 approximately corresponds to the outer diameter of perforated support tube 30. As noted above, during use, discharge gas 29 enters the cartridge filter 20 through the open inlet of the tube 26 and flows radially through the filter element 32. As the flow velocity or the pressure drop through the cartridge filter 20 increases. As illustrated in Figure 3, the increase in force causes the filter element 32 to expand ("swell") near the middle of the filter cartridge 20. which has a resultant effect of shortening the total length of the filter element 32. As the effective length of the filter element 32 is shortened, the perforations 36 in the support tube 20 are exposed.

The only resistance to the swelling effect is the seal between the filter element 32 and the inlet of the bubo 26, the end cap 28 and the support tube 30. The seal between the filter element 32 and the inlet of the tube 26, the end cap 28 and support tube 30 is determined by the tension and winding angle at which the ceramic fiber was wrapped over the support tube 30. The resistance of the seal is the product of the cosine of the winding angle multiplied by the tension in ceramic fiber. The resistance of the seal determines the flow velocity and the pressure drop of the cartridge filter that it can withstand without swelling. Currently, prior art cartridge filters as depicted in Figures 2 and 3 are limited to flow rates of approximately 45 acfm (1.27 mVmin.) And pressure drops of approximately 60 inches of H20 (14.91 kPa). . Once the seal between the filter element 32 and the inlet of the tube 26, the end cap 28 and the support tube 30 is broken, the perforations 36 without passing through the filter element 32. The course of the resulting leakage reduces the development of the cartridge filter.

The present invention, seen in Figure 4, overcomes the swelling effect and consequently improves the flow rate and the capacity of the pressure drop of the cartridge filter of diesel particles wound with regenerable fibers by improving the resistance of the seal. between the filter element and the support tube. The cartridge filter 120 of the present invention includes an open inlet of the tube 126 and a closed end cap 128. A perforated support tube 130 extends between the open inlet of the tube 126 and the closed end cap 128. A filter element L32 is placed on the support tube 130, the inlet of the tube 126 and the end cap 128. The filter element is preferably formed by an inorganic yarn substantially woven helically or wound interlaced onto the support tube 130.

The inlet of the tube 126 and the end cap 128 are "stepped" and include the radial edges 140, 142 respectively .. As can be seen by comparing the inventive cartridge filter 120 in Figure 4 and the prior art cartridge filter 20 of Figure 2, the filter element 32 of the cartridge filter is placed on the support tube 30 in a significantly different manner than the way in which the filter element 132 is placed on the support tube 130 of the cartridge filter. inventive 120. In the inventive cartridge filter 120, the helically wound or interlaced wound yarn of the filter element 132 extends over the radial edges 140, 142 such that the end portions 152 of the filter element 132 extend over the diameter portion. reduced 154 of the inlet of the tube 126 and the end cap 128, respectively. The radial edges 140, 142 allow an increase in the strength of the seal between the filter element 132 and the support tube 130. The radial edges 140, 142 have a height "H" sufficient to allow spinning the helical or coiled winding interlacing the filtering element 132 to secure the support tube 130. Preferably, the radial edges 140, 142 have a height "H" in the range of 1/8 inch to 2 inch (3.2 mm to 19.0 mm).

As the pressure drop across the cartridge filter 120 increases and the force exerted on the internal surface 134 of the filter element 132 increases, the filter element 132 extending over the radial edges 140, 142 does not allow it to move. As the middle portion of the filter element 132 strives for "swelling" due to the increase in pressure drop across the filter element 132, the portions 152 of the filter element 132 that extend over the radial edges 140, 142 are restricted from the movement. The effective length of the filter element 132 can not be shortened if the portions of the ends 152 are restricted, and thus the filter element 132 is prevented from swelling. This allows the cartridge filter 120 to handle higher flow rates and pressure drops than the prior art cartridge filters 20 shown in Figure 2 while maintaining the development of the filter.

In a preferred embodiment of the inventive cartridge filter 120, the support tube 130 is an electrically resistive tube as disclosed in US Patent No. 5,409,669 by Smith et al. to assist in securing the cartridge filter 120 in a diesel particulate trap (as shown in Figure 1), a base plate 160 and a saddle frame 162 can be secured to the inlet of the tube 126 and the end cap 128, respectively. Alternatively, the cartridge filter 120 can be secured in a diesel particle trap by other means known in the art, such as welding, screwing, etc.

As noted above, in a preferred embodiment of the present invention, the filter element 132 is formed by an inorganic yarn substantially wound helically or wound interlaced around the support tube 130. Examples of techniques for winding the inorganic tissue near the tube support 130 is found in U.S. Patent No. 5,248,481 by Bloom, et al. which describes a radially aligned winding process.

In the lateral compensation winding process, a continuous yarn of yarn which has been textured to provide a plurality of turns of continuous fibers or fiber segments extending from the center of the yarn is substantially wound helically around the support tube. to form a plurality of spin layers. The successive windings of the yarn are wound in opposite layers to provide an intertex of the centers. The centers of the successive windings of each successive layer are spaced to define four-sided openings, with the turns of the fibers or segments of fibers on the textured yarn that is protected within each of the four-sided openings to provide. trap for gas particles. The centers of the yarn at least one layer is generally away from the centers of spinning in an adjacent layer to divert the gas into a tortuous path through the filtering material.

The radially aligned winding method also uses a continuous textured filament yarn which is wound interlaced around the support tube. The successive wraps of the yarn are oppositely entangled in layers to provide interwoven centers, with the centers of the shells of each layer radially aligned to provide walls that are spaced apart to define four-sided openings. The turns of fibers or fiber segments of the textured yarn projected into each of the four-sided openings to provide a trap for particles of diesel discharge.

Preferably, the inorganic yarn wound or wound interlaced over the support tube 130 has a diameter in the range of about 0.5 'to about 5 mm. More preferably, the diameter is within the range from about 1 to about 3 mm. Such yarns are typically within the range of from about 780 to about 7,800 individual inorganic fibers. Preferably, the inorganic yarn comprises within the range from about 1,560 to about 4,680 individual fibers. Preferably, the inorganic yarn is twisted in a roll because such a construction can be textured to provide a superior filter material when compared to inorganic yarn that is not twisted in a roll.

The texturing of inorganic yarn improves its trap or filtration efficiency. Preferably, the inorganic yarn is textured so that it is fluffed, for example, by being textured so that the turns of continuous fibers, individual fiber segments or a combination of these extend externally from a dense center. More preferred are the continuous fiber turns. The inorganic yarn can be textured by techniques known in the art including, for example, air or mechanical injection texturing. S'e prefers air-jet texturing because it generally provides a textured yarn that has fewer fiber segments and more fiber turns than texturized by mechanical technique. An air injection texturing machine suitable for this purpose is available under the trademark of the SIDEWINDER MODEL 17 designation from the Enterprise Machine and Development Corporation of New Castle, Delaware. Preferably, the textured inorganic yarn has a diameter in the range from about 1 to about 10 m. More preferably, the diameter of the textured inorganic yarn is in the range of about 3 to about 6 mm.

The inorganic fibers comprising the inorganic yarn preferably have a diameter in the range from about 5 to about 20 microns. More preferably, the inorganic fibers have a diameter in the range from about 7 to about 15 microns. Fibers having a diameter within the specified ranges are generally easier to make and texture than fibers having diameters substantially outside these ranges. In addition, fibers substantially below 5 micrometers in diameter tend to be easily damaged (for example, it breaks when textured). Fibers substantially above 25 micrometers in diameter typically provide a filter which has lower efficiency than fibers having diameters within specified ranges.

The inorganic fibers comprising the inorganic yarn are preferably heat resistant. The heat-resistant fibers can be, for example, amorphous, polycrystalline or a combination thereof. Heat resistant fibers include special high temperature glass fibers, such as GLASS S2 or GLASS E, commercially available from Owens-Corning of Toledo, Ohio; continuous melt silica fibers, such as QURTZEL ™ fused quartz yarn, commercially available from Quartz Products Corporation of Louisville, Kentucky; and ceramic metal oxide fibers such as NEXTEL ™ 312, 440 or 550 ceramic fibers, commercially available from 3M Company of St. Paul, Minnesota. Woven, woven or braided fabrics made of mixtures of ceramic and glass yarns can also be used. For applications below approximately 330 ° C, conventional glass fibers can be used.

To improve the filtration efficiency, inorganic spinning is preferably substantially wound helically or wound interlaced around the support tube 130 as described above. The inorganic yarn can be wound around the support tube 130 such that the centers of the successive windings of each of the successive layers are radially aligned (as described in US Pat. No. 5,248,482), or the inorganic yarn can be wound on around the support tube 130 such that the centers of the successive coils of the successive layers are laterally apart from one another (as described in US Pat. No. 5,248,481).

Preferably, each of the filter elements has a thickness in the range from about 1 to about 25mm. For filtering elements comprising substantially helical winding or interlocked winding, the textured yarn comprises inorganic fibers, the preferred total thickness of the interwoven wound or wound fibers being in the range of about 5 to about 15 mm. Thicknesses substantially larger than the established ranges can increase the cost unduly and can also result in undesirable high back pressures, while substantially smaller than the established ranges can provide inadequate filtration efficiency.

Each filter element 132 may alternatively comprise one or more layers of more than one type of filter material. For example, the filter element 132 may comprise one or more layers of substantially the inorganic yarn helically coiled or interwoven wound, or it may comprise one or more layers of non-woven webs of inorganic fibers, where this tangle is held against the tube. support 130 for substantially the helically wound or interlaced winding of the inorganic yarn.

The following examples are provided to illustrate the improved development created by the invention, but do not intend to limit these.

EXAMPLES The tests were developed to determine the improvements in the operation of the cartridge filter with the "stepped" cartridge design. Test 1 was in a test in a short period, with great pressure drop and high flow velocity. Test 2 was a test of durability over a long period of time with a high pressure drop and high flow velocity. Test 3 was a characterization test to fully characterize the differences between the prior art cartridge filter 20 and the inventive cartridge filter 120 (incorporating the "stepped" tube inlet 126 and the "stepped" end cap. ).

Test 1: in a short period of time with a high pressure drop and high flow velocity The objective of Test 1 was to study the operation of the filter in steady state in a short period of time of an electrically regenerable cartridge filter of the prior art. The cartridge filter of the prior art and the inventive cartridge filter were identical in all respects except for the provision of a "stepped" tube inlet of the inventive cartridge filter. The filtering elements of the two test cartridges were otherwise identical. The conditions for the test were: 1) 10 minutes of regeneration followed by one minute of cooling; 2) The regeneration was started at 60 kPa; 3) The discharge flow through the cartridge was 2.81 m3 / minute / cartridge with a discharge temperature of the exhaust manifold of 450 ° C; 4) The discharge was created by a diesel engine of 4 cylinders of 2.3 liters at 1845 r.p.m. and 98 N * m of charge; 5) Fuel with low sulfur content (0.05%) and little oil ash was used; and 6) two cartridge filters were placed in a test can.

The conditions used in this test created a fivefold increase in flow velocity over those typically handled by the prior art cartridge filter.

The data collected during the test include the time between the regenerations and the post-regeneration backpressures. This test determined the operation of the invention in a short period of time. The invention was tested by loading the cartridge filters (the cartridge of the prior art and the inventive cartridge) with soot at the predetermined pressure of 60 kPa. Once the cartridges reached the pressure drop they were regenerated and the charging cycle was repeated. The test ran for twenty-four hours to record the loading time between regenerations.

If the loading time between regenerations has remained constant, the cartridge filters usually pass the test. This means that there is no change in the operation of the cartridge filter during the test. Table 1 represents the result of the test between the cartridge filter and the cartridge filter with the inlet of the stepped tube of the present invention.

As the data in Table 1 shows, the prior art cartridge filter failed after 5 hours of operation. The time required for the cartridge filter to reach the pressure drop necessary to operate the regeneration has been increased to 300 minutes, indicating that a leak has formed. The examination of the cartridge filter of the prior art shows that the "swelling" effect took place. Another use results in a total failure of the prior art filter assembly, as tested by the infinity charging time (which indicates that the pressure drop required to operate was never achieved). In contrast, the inventive cartridge filter was increased from 105 to 120 minutes, this is a huge improvement over the cartridge filter of the prior art.

Table 1. Results of the operations * The pressure drop leveled and did not increase, so the limit of the commissioning of the regeneration was never realized.

Test 2: High speed test • flow and large pressure drop over a long period of time The objective of Test 2 was to study the filter operation in a steady state over a long period of time (at a flow velocity and high levels of pressure drop). The operation of the cartridge filter was observed over a period of about 1500 hours. The "stepped" design was installed in both the inlet of the tube 126 and the end cap 128 of the inventive cartridge filter. The conditions for the test were as follows: 1) 10 minutes of regeneration with one minute followed by cooling; 2) The regeneration was started at 40 kPa; 3) The discharge that flowed through the cartridges was 2.8 m3 / minutes / cartridges with an exhaust manifold discharge temperature of 450 ° C; 4) The unloading was created by a diesel engine of 4 cylinders of 2.3 liters at 1845 r.p.m. and 98 N * m of charge; 5) Fuel with low sulfur content (0.05%) and little oil ash was used; and 6) two cartridge filters were placed in a test can. The performance characteristics of the inventive cartridge filter that was observed include the charging time between the regenerations and the filtration efficiency.

Loading time The charging time is the time required for the filters to be charged from the post regeneration pressure drop to the 40 kPa pressure drop. The cartridge filter charge time ranges from 45-50 minutes in the initial test pulse for approximately 20 minutes at the end of the test period. The charging time will naturally decrease by the time the cartridges are filled with byproducts of the burnt lubricating oil that has passed through the motor. The by-products of the burned lubrication oil are called oil ash. If the loading time increases with time, it may indicate that the inventive cartridge filter has failed. The charging time may increase if the seal between the filter element and the support tube as a structural heater has failed and allows the discharge to flow out. Because the discharge time decreases with time, no leakage occurred in the inventive cartridge filter.

Efficiency measures The efficiencies of the inventive cartridge filter range from 78-98% for the duration of the test. The efficiencies were taken at a pressure drop of 35 kPa. The efficiency of the inventive cartridge filter increased as the test progressed. The increase in efficiency was due to the accumulation of oil ash in the filter medium. The oil ash was collected within the filter element and acted as an additional filtering mechanism. The fact that cartridge filters maintain efficiency throughout the test duration indicates that no leakage was present within the cartridge filter. In addition, the inventive cartridge filter maintained its high efficiency despite the increase in pressure drop. Notably, the prior art cartridge filter failed the largest pressure drop test.

Test 3: Characterization of the Cartridge Filter Test with and without the Invention - Test 3 was developed on a 3.4-liter Cummins diesel injection engine. The operating conditions for the test were 1560 r.p.m. of engine operating speed and 132 N * m of load on the engine. The test compares the filtration efficiency of a prior art filter cartridge and the inventive cartridge filter. Table 2 shows the results of Test 3.

Table 2 shows that the inventive cartridge filter was able to maintain performance similar to the prior art cartridge filter at low flow rates and continued its operation at high flow rates, the inventive cartridge filter maintained its filtration efficiency, without fails, to the largest pressure drop tests.

The results of the combined test show that the inventive cartridge filter was able to maintain durability at a high flow rate and pressure drop while maintaining high levels of efficiency. The inventive cartridge filter thus clearly exhibits superior performance over the cartridge filters of the prior art.

Table 2. Comparisons of the Efficiency of the Invention Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the scope and perspective of the invention. .

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (10)

1. A diesel particulate filter cartridge, characterized in that it comprises: a longitudinal hollow tube having a pierced portion and a portion at the end, the portion at the end having a first outer diameter, and the pierced portion having a second diameter that is smaller than the second diameter; Y a filter element placed in the perforated tube, the filter element extends over the second diameter of the perforated portion and the first diameter of the final portion.

2. A diesel particulate filter cartridge, characterized in that it comprises: a hollow tube having a first portion at the unbored end and a second portion at the end separated by a longitudinally bored central portion, extending between the first end portion and the second end portion, the first end portion and the second end portion have the first outer diameters, and the central pierced portion has a second outer diameter; Y a filter element placed in the hollow tube, the filter element extends over the first portion of the non-drilled end, the central portion pierced and the second portion of the end not drilled.

3. The diesel particulate cartridge filter of claim 2, characterized in that the first end portion is sealed.

4. The diesel particulate cartridge filter of claim 2, characterized in that the hollow tube is an electrically resistive heating element.

5. The diesel particulate cartridge filter of claim 2, characterized in that the filter element comprises a heat-resistant yarn wound and helically interlaced on the hollow tube to form a plurality of spinning layers, such a yarn having a center from such externally projected fiber segments or segments, where successive coils are oppositely wound on each layer to provide intertwined centers, the centers of the coils of each layer are spaced apart to provide substantially uniform four-sided apertures wherein said fiber segments being projected interlacing to form traps for the particles transported by the discharge.

6. The diesel particulate cartridge filter of claim 5, characterized in that the yarn is an inorganic yarn.

7. At the inlet of the tube for use with the cartridge filter for filtering a gas carrying particles, the cartridge filter has at least one open end, the tube inlet comprises a first end portion and a second portion, the first portion the inlet of the tube having a first diameter and the second end portion of the tube inlet has a second diameter, characterized in that the first diameter is larger than the second diameter, a portion of the transition step extending between the first diameter of the first end portion and the second diameter of the second end portion, a filter element secured to the inlet of the tube by extending the cartridge filter element over the first end portion and the second portion of the end entrance. tube, such that the filter element covers the portion of the step of the tube inlet.

8. The tube inlet of claim 7, characterized in that the second end portion of the tube inlet is secured to a base plate.

9. The tube inlet of claim 8, characterized in that the base plate includes at least one opening to allow the discharge of gases as it passes through the base plate into the interior of the cartridge.

10. The entrance of the claim tube 7, characterized in that the tube inlet further comprises the means for mounting the tube inlet and the cartridge filter within a discharge system.