Apparatus and method for increasing and measuring the filtration efficiency of a honeycomb body

Abstract

The disclosed apparatus (400) and method apply inorganic particles (407) to a plugged honeycomb (415) comprising a porous wall, an inlet end, and an outlet end. The apparatus (400) includes a particle counter (408), and the method includes counting selected portions of inorganic particles from a first sampling port (410) located upstream of the plugged honeycomb (415) and a second sampling port (412) located downstream of the plugged honeycomb (415). The selected portions of the inorganic particles are within a pre-selected range of inorganic particle sizes. For example, filtration efficiency can be increased by determining the filtration efficiency simultaneously with the deposition of inorganic particles.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to methods and apparatus for increasing and online measurement of the filtration efficiency of cellular cells. Background Technology

[0002] Particulate filters (e.g., diesel particulate filters and gasoline particulate filters (GPF)) filter particulates from the exhaust gas stream of an engine (e.g., a motor vehicle that burns diesel and gasoline fuels).

[0003] Currently, the deposition process of inorganic particles on the walls of the clogging cell is controlled by running several test pieces before production batches, thereby determining the target spraying time (or total spray suspension weight) to achieve the desired FE (filtration efficiency). Once this target is determined, all parts in the deposition process have the same process setpoint. Once a part reaches the target time (or weight), it is removed and tested to measure the final actual FE value. If a part is over-coated with inorganic particles, the FE value will exceed the upper limit at which it would be rejected; if a part is under-coated, it may be run or not rerun to try and reach the target FE. Therefore, the feedback of the deposition process is a semi-closed-loop process. Summary of the Invention

[0004] One or more embodiments of this disclosure relate to an apparatus configured to apply inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end, the apparatus comprising: a conduit extending from a first end to a second end; a deposition zone configured to receive the plugged honeycomb in fluid communication with the second end of the conduit; an inlet in fluid communication with the conduit, the inlet being located upstream of the deposition zone; an inorganic particle source in fluid communication with the inlet, configured to deliver inorganic particles to the inlet and the deposition zone; a flow generator in fluid communication with the conduit and the deposition zone, configured to establish a flow of fluid and inorganic particles introduced into the conduit; a first sampling port located upstream of and in fluid communication with the deposition zone; a second sampling port located downstream of and in fluid communication with the deposition zone; and a particle counter in fluid communication with the first and second sampling ports, configured to count selected portions of inorganic particles within a pre-selected range of inorganic particle size.

[0005] Other embodiments of this disclosure relate to an apparatus configured to apply inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end. The apparatus includes: a conduit extending from a first end to a second end; a deposition zone configured to receive the plugged honeycomb in fluid communication with the second end of the conduit; an inlet in fluid communication with the conduit, the inlet being located upstream of the deposition zone; and an inorganic particle source, a liquid source, and a binder in fluid communication with the inlet, configured to deliver a mixture of inorganic particles, liquid, and binder to an atomizing nozzle and to the deposition zone; and a flow generator in fluid communication with the conduit and the deposition zone, configured to establish a flow pattern for the fluid introduced into the conduit and... The flow of inorganic particles; a first sampling port located upstream of and in fluid communication with the sedimentation zone; a second sampling port located downstream of and in fluid communication with the sedimentation zone; a particle counter in fluid communication with the first and second sampling ports, configured to count a selected portion of inorganic particles within a pre-selected range of inorganic particle sizes, located upstream and downstream of the sedimentation zone; and a processor configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the sedimentation zone and nd = the number of inorganic particles downstream of the sedimentation zone.

[0006] Additional embodiments of this disclosure relate to a method of applying inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end, the method comprising: causing the inorganic particles to flow from a first end of a conduit to a second end of a conduit into the plugged honeycomb; sampling a portion of the inorganic particles from a first sampling port located upstream of and in fluid communication with the plugged honeycomb and from a second sampling port located downstream of and in fluid communication with the plugged honeycomb; and counting selected portions of the inorganic particles from the first and second sampling ports, the selected portions of the inorganic particles being within a pre-selected range of inorganic particle sizes.

[0007] Additional embodiments of this disclosure relate to a method for increasing the filtration efficiency of a porous honeycomb filter comprising a plugged honeycomb cell containing porous walls, an inlet end, and an outlet end. The method includes: causing an inlet flow of inorganic particles to flow into the inlet end of the plugged honeycomb cell; counting the number of inlets of selected portions of inorganic particles entering the plugged honeycomb cell; counting the number of outlets of selected portions of inorganic particles exiting the plugged honeycomb cell; wherein inorganic particles entering the plugged honeycomb cell but not exiting the plugged honeycomb cell are deposited on and / or deposited into the porous walls of the honeycomb cell, thereby increasing the filtration efficiency of the plugged honeycomb cell as deposition continues; determining the filtration efficiency of the plugged honeycomb cell with deposited particles based on the number of inlets and outlets; and terminating the flow of the inlet flow of inorganic particles entering the inlet end of the plugged honeycomb cell based on the determined filtration efficiency. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained by referring to embodiments (some of which are shown in the accompanying drawings). However, it should be understood that the accompanying drawings merely illustrate typical embodiments of this disclosure and are therefore not intended to limit its scope, as other equally effective embodiments are applicable.

[0009] Figure 1 A schematic diagram of a honeycomb structure;

[0010] Figure 2 A wall-flow particulate filter is schematically shown according to an embodiment disclosed and described herein;

[0011] Figure 3 yes Figure 8 The cross-sectional longitudinal view of the particulate filter shown;

[0012] Figure 4 A schematic diagram showing the wall of a honeycomb structure with a particle load;

[0013] Figure 5 The illustration shows an apparatus configured to deposit inorganic particles on a honeycomb substrate according to an embodiment of the present disclosure;

[0014] Figure 6A and 6B The illustration shows the functional relationship between the particle filter's capture mechanism and particle size.

[0015] Figure 7 This diagram shows a representative particle size distribution of aggregates formed by aerosol processes upstream and downstream of a plugged cellular structure according to one or more embodiments.

[0016] Figure 8 A particle concentration map showing the aerosol process upstream of the plugged honeycomb during the deposition process;

[0017] Figure 9 Particle concentration diagrams showing the aerosol processes upstream and downstream of the plugged honeycomb during the deposition process;

[0018] Figure 10 The illustration shows an online filtration efficiency measurement performed during the aerosol deposition process on a plugged honeycomb structure; and

[0019] Figure 11 This graph shows the correlation between the final online filtration efficiency measurement and the offline smoke filtration efficiency measurement. Detailed Implementation

[0020] Before describing several exemplary embodiments of this disclosure, it is to be understood that this disclosure is not limited to the details of the construction or process steps described in the following specification. This disclosure can be practiced or otherwise implemented in various ways.

[0021] In one set of embodiments, the apparatus disclosed herein is configured to apply inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end. The apparatus includes: a conduit extending from a first end to a second end; a deposition zone configured to receive the plugged honeycomb and in fluid communication with the second end of the conduit; an inlet in fluid communication with the conduit, the inlet being located upstream of the deposition zone; an inorganic particle source in fluid communication with the inlet, configured to deliver inorganic particles to the inlet and the deposition zone; a flow generator in fluid communication with the conduit and the deposition zone, configured to establish a flow of fluid and inorganic particles introduced into the conduit; a first sampling port located upstream of and in fluid communication with the deposition zone; a second sampling port located downstream of and in fluid communication with the deposition zone; and a particle counter in fluid communication with both the first and second sampling ports, configured to count selected portions of inorganic particles within a pre-selected range of inorganic particle sizes.

[0022] In some implementations, the particle counter is configured to count inorganic particles upstream and downstream of the sedimentation zone.

[0023] 1. The device of claim 2, wherein the pre-selected inorganic particle size range is from 0.1 µm to 10 µm.

[0024] 2. The device of claim 2, wherein the pre-selected inorganic particle size range is from 0.1 µm to 1 µm.

[0025] 3. The device of claim 2, wherein the pre-selected inorganic particle size range is from 0.1 µm to 0.5 µm.

[0026] 4. The device of claim 2, wherein the pre-selected inorganic particle size range is from 0.3 µm to 0.5 µm.

[0027] 5. The device of claim 2, wherein the particle counter comprises an optical spectrometer.

[0028] 6. The device of claim 2, wherein the particle counter comprises an engine exhaust particle size analyzer spectrometer.

[0029] 7. The apparatus of claim 2, wherein the particle counter comprises a scanning migration particle size analyzer.

[0030] 8. The apparatus of claim 2, wherein the particle counter comprises a coagulated particle counter.

[0031] 9. The apparatus of claim 2, further comprising an inorganic particle concentration dilution device upstream of the particle counter and downstream of the first sampling port, the inorganic particle concentration dilution device being configured to reduce the inorganic particle concentration at the first sampling port before flowing to the particle counter.

[0032] 10. The apparatus of claim 11, wherein the inorganic particle concentration dilution device includes a dilution chamber configured to provide a gas-particle ratio of 20:1 to 100:1 within the dilution chamber.

[0033] 11. The apparatus of claim 12, wherein the dilution chamber is configured to provide a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

[0034] 12. The apparatus of claim 13, wherein the dilution chamber includes a diversion connection that provides a gas-particle ratio of 20:1 to 100:1 within the dilution chamber.

[0035] 13. The apparatus of claim 13, wherein the dilution device includes a diversion connection that provides a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

[0036] In some embodiments, the device also includes a processor configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the deposition zone and nd = the number of inorganic particles downstream of the deposition zone.

[0037] 14. The device of claim 1, wherein the inorganic particle source is in fluid communication with the atomizing nozzle.

[0038] 15. The device of claim 17, wherein the fluid is a gas, and the atomizing nozzle is in fluid communication with the fluid source and the binder, and wherein the binder, liquid, and inorganic particulate source are configured to flow through the atomizing nozzle to form an aerosol.

[0039] In some implementations, the flow generator includes a fan.

[0040] In another set of embodiments, the apparatus disclosed herein is configured to apply inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end. The apparatus includes: a conduit extending from a first end to a second end; a deposition zone configured to receive the plugged honeycomb in fluid communication with the second end of the conduit; an inlet in fluid communication with the conduit, the inlet being located upstream of the deposition zone; and inorganic particle sources, a liquid source, and a binder in fluid communication with the inlet, configured to deliver a mixture of inorganic particles, liquid, and binder to an atomizing nozzle and to the deposition zone; and a flow generator in fluid communication with the conduit and the deposition zone, configured to establish a flow introduced into the conduit. The flow of bulk and inorganic particles; a first sampling port located upstream of and in fluid communication with the sedimentation zone; a second sampling port located downstream of and in fluid communication with the sedimentation zone; a particle counter in fluid communication with the first and second sampling ports, configured to count selected portions of inorganic particles within a pre-selected range of inorganic particle sizes, located upstream and downstream of the sedimentation zone; and a processor configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = number of inorganic particles upstream of the sedimentation zone and nd = number of inorganic particles downstream of the sedimentation zone.

[0041] In another set of embodiments disclosed herein, there is a method for applying inorganic particles to a plugged honeycomb containing a porous wall, an inlet end, and an outlet end. The method includes: causing the inorganic particles to flow from a first end of a conduit to a second end of the conduit and into the plugged honeycomb; sampling a portion of the inorganic particles from a first sampling port located upstream of and in fluid communication with the plugged honeycomb and from a second sampling port located downstream of and in fluid communication with the plugged honeycomb; and counting selected portions of the inorganic particles from the first and second sampling ports, the selected portions of the inorganic particles being within a pre-selected range of inorganic particle sizes.

[0042] In some implementations, counting is performed using a particle counter.

[0043] In some implementations, a flow generator in fluid communication with pipes and plugged cell is used to generate the flow of inorganic particles, which is configured to establish the flow of fluid and inorganic particles.

[0044] In some implementations, the fluid includes gas, and the flow generator includes a fan.

[0045] In some implementations, the pre-selected inorganic particle size range is from 0.1 µm to 10 µm.

[0046] In some embodiments, the pre-selected inorganic particle size range is from 0.1 µm to 1 µm. In some embodiments, the pre-selected inorganic particle size range is from 0.1 µm to 0.5 µm. In some embodiments, the pre-selected inorganic particle size range is from 0.3 µm to 0.5 µm. In some embodiments, the particle counter includes an optical spectrometer. In some embodiments, the particle counter includes an engine exhaust particle size analyzer spectrometer. In some embodiments, the particle counter includes a scanning migration particle size analyzer. In some embodiments, the particle counter includes a condensed particle counter.

[0047] In some embodiments, the method further includes diluting the particle stream upstream of the particle counter and downstream of the first sampling port to reduce the concentration of inorganic particles at the first sampling port before flowing to the particle counter. In some embodiments, the particle stream is diluted in a dilution chamber configured to provide a gas-particle ratio of 20:1 to 100:1. In some embodiments, the dilution chamber is configured to provide a gas-particle ratio of 70:1 to 100:1. In some embodiments, the dilution of the particle stream includes splitting the particle stream to provide a gas-particle ratio of 20:1 to 100:1 within the dilution chamber. In some embodiments, the dilution of the particle stream includes splitting the particle stream to provide a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

[0048] In some implementations, the method further includes calculating the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the cell and nd = the number of inorganic particles downstream of the clogging cell.

[0049] In some implementations, inorganic particles flow through an atomizing nozzle.

[0050] In some implementations, the fluid is a gas, and inorganic particles and liquids flow with a binder through an atomizing nozzle to form an aerosol.

[0051] In another embodiment, this document discloses a method for increasing the filtration efficiency of a porous honeycomb filter body comprising a clogging honeycomb body containing a porous wall, an inlet end, and an outlet end. The method includes: causing an inlet flow of inorganic particles to flow into the inlet end of the clogging honeycomb body; counting the number of inlets of selected portions of inorganic particles entering the clogging honeycomb body; counting the number of outlets of selected portions of inorganic particles leaving the clogging honeycomb body; wherein inorganic particles entering the clogging honeycomb body but not leaving the clogging honeycomb body are deposited on and / or deposited into the porous wall of the honeycomb body, thereby increasing the filtration efficiency of the clogging honeycomb body as deposition continues; determining the filtration efficiency of the clogging honeycomb body with deposited particles based on the number of inlets and outlets; and terminating the flow of the inlet flow of inorganic particles entering the inlet end of the clogging honeycomb body based on the determined filtration efficiency.

[0052] In some embodiments, a selected portion of the inlet quantity count is within a pre-selected range of inorganic particle sizes; in some embodiments, a selected portion of the outlet quantity count is within a pre-selected range of inorganic particle sizes.

[0053] In some embodiments, the pre-selected range of inorganic particle size for a selected portion of the inlet and outlet counts is the same; in some embodiments, the pre-selected range of inorganic particle size is 0.1 µm to 10 µm; in some embodiments, the pre-selected range of inorganic particle size is 0.1 µm to 1 µm; in some embodiments, the pre-selected range of inorganic particle size is 0.1 µm to 0.5 µm; in some embodiments, the pre-selected range of inorganic particle size is 0.3 µm to 0.5 µm.

[0054] In some embodiments, the inlet flow also includes a fluid; in some of these embodiments, the fluid is a gas.

[0055] In some embodiments, counting is performed using a particle counter; in some of these embodiments, the particle counter includes an optical spectrometer; in some of these embodiments, the particle counter includes an engine exhaust particle size analyzer spectrometer; in some of these embodiments, the particle counter includes a scanning migration particle size analyzer; in some of these embodiments, the particle counter includes a condensed particle counter.

[0056] In some implementations, the inlet stream contains aerosolized particles.

[0057] In some embodiments, the inlet quantity is obtained from a dilution portion of the inlet flow directed into the particle counter; in some of these embodiments, the dilution portion has a gas-particle ratio of 20:1 to 100:1; in some of these embodiments, the dilution portion has a gas-particle ratio of 70:1 to 100:1; in some of these embodiments, the outlet quantity is obtained from a dilution portion of the outlet flow directed into the particle counter.

[0058] In some of the above embodiments, the termination also includes terminating the inlet flow of inorganic particles into the inlet end of the blockage cell after the filtration efficiency has reached the target filtration efficiency.

[0059] In some of the above embodiments, the termination also includes terminating the flow of the inlet stream of inorganic particles into the inlet end of the blockage cell after the filtration efficiency has not reached the target filtration efficiency within the target deposition time.

[0060] In some of the above embodiments, the termination further includes terminating the flow of the inlet stream of inorganic particles into the inlet end of the plugged cell if the number of outlets exceeds the maximum number of outlets.

[0061] In some of the above embodiments, the termination also includes terminating the flow of the inlet stream of inorganic particles into the inlet end of the plugged cell if the number of outlets during the target deposition time exceeds the maximum number of outlets.

[0062] In some of the above embodiments, the plugged cell includes inorganic particles deposited in and / or on the porous wall before the inlet flow of the inorganic particles enters the inlet end of the plugged cell, wherein the flow of the inlet flow increases the amount of inorganic particles captured by the plugged cell.

[0063] In some of the above embodiments, the plugged honeycomb does not contain inorganic particles deposited in and / or on the porous wall before the inlet flow of inorganic particles is initiated into the inlet end of the plugged honeycomb, wherein the flow of the inlet flow introduces inorganic particles into the plugged honeycomb.

[0064] In some of the above embodiments, determining the filtration efficiency (μe) involves calculating the ratio of (number of inlets - number of outlets) / (number of inlets).

[0065] The apparatus and methods disclosed herein relate to applying inorganic particles to a plugged honeycomb containing porous walls. See now. Figure 1This document illustrates a honeycomb structure 100 according to one or more embodiments shown and described herein. In one embodiment, the honeycomb structure 100 may include a plurality of walls 115 defining a plurality of internal channels 110. The plurality of internal channels 110 and the intersecting channel walls 115 extend between a first end 105 (which may be an inlet end) and a second end 135 (which may be an outlet end) of the blocked honeycomb structure. The honeycomb structure may have one or more channels blocked on one or both of the first end 105 and the second end 135. The pattern of the blocked channels of the honeycomb structure is not limited. In some embodiments, the pattern of the blocked and unblocked channels at one end of the blocked honeycomb structure may be, for example, a checkerboard pattern, wherein alternating channels at one end of the blocked honeycomb structure are blocked. In some embodiments, a blocked channel at one end of the blocked honeycomb structure has a corresponding unblocked channel at the other end, and an unblocked channel at one end of the blocked honeycomb structure has a corresponding blocked channel at the other end.

[0066] In one or more embodiments, the plugged honeycomb may comprise cordierite, aluminum titanate, enstatite, andalusite, forsterite, corundum (SiC), spinel, sapphire, or periclase, or combinations thereof. Typically, cordierite has a composition according to the chemical formula Mg₂Al₄Si₅O₁₈. In some embodiments, the pore size, porosity, and pore size distribution of the ceramic material are obtained in a controlled manner, for example, by changing the particle size of the ceramic raw materials. Furthermore, a pore-forming agent may be included in the ceramic batch used to form the plugged honeycomb.

[0067] In some embodiments, the walls of the plugged cell may have an average thickness greater than or equal to 25 µm and less than or equal to 250 µm, for example: greater than or equal to 45 µm and less than or equal to 230 µm, greater than or equal to 65 µm and less than or equal to 210 µm, greater than or equal to 65 µm and less than or equal to 190 µm, or greater than or equal to 85 µm and less than or equal to 170 µm. The walls of the plugged cell can be described as having: a base portion comprising a body portion (also referred to herein as the body), and a surface portion (also referred to herein as the surface). The surface portion of the wall extends from the surface of the wall of the plugged cell toward the body portion of the plugged cell into the wall. The surface portion may extend from 0 (zero) into the base portion of the wall of the plugged cell to a depth of about 10 µm. In some embodiments, the surface portion may extend into the base portion of the wall to about 5 µm, about 7 µm, or about 9 µm (i.e., a depth of 0 (zero)). The body portion of the plugged cell constitutes the thickness of the wall minus the surface portion. Therefore, the body portion of the plugged cellular structure can be determined using the following equation:

[0068] t total - 2t surface

[0069] In the formula, t is always the total thickness of the wall, and t_surface is the thickness of the wall surface.

[0070] In one or more embodiments, the median pore size of the body of the plugged honeycomb (before the application of any filter material) is greater than or equal to 7 µm and less than or equal to 25 µm, for example: greater than or equal to 12 µm and less than or equal to 22 µm, or greater than or equal to 12 µm and less than or equal to 18 µm. For example, in some embodiments, the median pore size of the body of the plugged honeycomb may be about 10 µm, about 11 µm, about 12 µm, about 13 µm, about 14 µm, about 15 µm, about 16 µm, about 17 µm, about 18 µm, about 19 µm, or about 20 µm. Generally, the pore size of any given material exhibits a statistical distribution. Therefore, (before the application of any filter material), the term "median pore size" or "d50" refers to a length measurement based on the statistical distribution of all pores: 50% of the pores have a pore size greater than it, and the remaining 50% of the pores have a pore size less than it. Pores can be formed in a ceramic body by at least one of the following methods: (1) particle size and size distribution of inorganic batch material; (2) furnace / heat treatment firing time and temperature scheme; (3) furnace atmosphere (e.g., low or high oxygen content and / or water content); and (4) pore-forming agent, such as polymers and polymer particles, starch, wood flour, hollow inorganic particles and / or graphite / carbon particles.

[0071] In a specific embodiment, the median pore size (d50) of the bulk of the plugged honeycomb (before applying any filter material) is in the range of 10 µm to about 16 µm (e.g., 13-14 µm), and d10 refers to a length measurement based on the statistical distribution of all pores such that 90% of the pores have a diameter greater than it and the remaining 10% have a diameter less than it, with d10 being approximately 7 µm. In a specific embodiment, d90 refers to a length measurement based on the statistical distribution of all pores such that 10% of the pores of the bulk of the plugged honeycomb (before applying any filter material) have a diameter greater than it and the remaining 90% have a diameter less than it, with d90 being approximately 30 µm. In a specific embodiment, the median diameter (D50) of the secondary particles or aggregates is approximately 2 micrometers. In specific embodiments, it has been determined that excellent filtration efficiency and low pressure drop are achieved when the median size D50 of the aggregates and the median wall pore size d50 of the bulk honeycomb are such that the ratio of the median size D50 of the aggregates to the median wall pore size d50 of the bulk honeycomb is 5:1 to 16:1. In more specific embodiments, the ratio of the median size D50 of the aggregates to the median wall pore size d50 of the bulk honeycomb (before applying any filter material) is 6:1 to 16:1, 7:1 to 16:1, 8:1 to 16:1, 9:1 to 16:1, 10:1 to 16:1, 11:1 to 16:1, or 12:1 to 6:1, which provides excellent filtration efficiency and low pressure drop.

[0072] In some embodiments, without considering the coating, the bulk porosity of the plugged honeycomb body can be greater than or equal to 50% to less than or equal to 75%, as determined by mercury intrusion porosimetry. Other methods for measuring porosity include scanning electron microscopy (SEM) and X-ray tomography, both of which are particularly useful for measuring surface porosity and bulk porosity that are independent of each other. For example, in one or more embodiments, the bulk porosity of the plugged honeycomb body can be in the range of: about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 50% to about 60%, about 50% to about 58%, about 50% to about 56%, or about 50% to about 54%.

[0073] In one or more embodiments, the median surface pore size of the surface portion of the plugged honeycomb is greater than or equal to 7 µm and less than or equal to 20 µm, for example: greater than or equal to 8 µm and less than or equal to 15 µm, or greater than or equal to 10 µm and less than or equal to 14 µm. For example, in some embodiments, the median surface pore size of the surface of the plugged honeycomb may be about 8 µm, about 9 µm, about 10 µm, about 11 µm, about 12 µm, about 13 µm, about 14 µm, or about 15 µm.

[0074] In some embodiments, the surface porosity of the plugged honeycomb can be greater than or equal to 35% to less than or equal to 75% before applying the filter material deposit, as determined by mercury intrusion porosimetry, SEM, or X-ray tomography. For example, in one or more embodiments, the surface porosity of the plugged honeycomb can be less than 65%, such as less than 60%, less than 55%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 48%, or less than 36%.

[0075] See now Figure 2 and 3 The diagram schematically illustrates a honeycomb structure in the form of a particulate filter 200. The particulate filter 200 can be used as a wall-flow filter to filter particulate matter from an exhaust gas stream 250 (e.g., exhaust gas from a gasoline engine, in which case the particulate filter 200 is a gasoline particulate filter). The particulate filter 200 typically comprises a honeycomb structure having a plurality of channels 201 or pores extending between an inlet end 202 and an outlet end 204, defining an overall length La (e.g., ...). Figure 3 (As shown). The channels 201 of the particulate filter 200 are formed and at least partially defined by a plurality of intersecting channel walls 206 extending from the inlet end 202 to the outlet end 204. The particulate filter 200 may also include a skin layer 205 surrounding the plurality of channels 201. This skin layer 205 may be extruded during the formation of the channel walls 206 or may be formed as a post-applied skin layer in subsequent processing, for example by applying a skin adhesive to the outer peripheral portion of the channels.

[0076] Figure 3 Showing Figure 2 The axial cross-section of the particulate filter 200. In some embodiments, certain channels are designated as inlet channels 208, and certain other channels are designated as outlet channels 210. In some embodiments of the particulate filter 200, at least a first set of channels may be blocked by plugs 212. Typically, the plugs 212 are arranged near the ends of the channels 201 (i.e., the inlet end or the outlet end). The plugs are typically arranged in a predetermined pattern, such as... Figure 2 The chessboard pattern shown has each of the other channels blocked at its end. Entrance channel 208 may be blocked at or near exit end 204, and exit channel 210 may be blocked at or near entrance end 202 on a channel that does not correspond to an entrance channel, such as... Figure 3 As shown. Therefore, each channel can be blocked only at or near one end of the particulate filter.

[0077] Although Figure 2The checkerboard clogging pattern is roughly shown, but it should be understood that alternative clogging patterns can be chosen in porous ceramic honeycomb articles. In the embodiments described herein, the particulate filter 200 can be formed with a channel density of up to about 600 channels per square inch (cpsi). For example, in some embodiments, the particulate filter 100 can have a channel density of about 100 cpsi to about 600 cpsi. In some other embodiments, the particulate filter 100 can have a channel density of about 100 cpsi to about 400 cpsi or even about 200 cpsi to about 300 cpsi.

[0078] In the embodiments described herein, the channel wall 206 of the particulate filter 200 may have a thickness greater than about 4 mils (101.6 micrometers). For example, in some embodiments, the thickness of the channel wall 206 may be from about 4 mils to up to about 30 mils (762 micrometers). In some other embodiments, the thickness of the channel wall 206 may be from about 7 mils (177.8 micrometers) to about 20 mils (508 micrometers).

[0079] In some embodiments of the particulate filter 200 described herein, the channel wall 206 of the particulate filter 200 may have a bare open porosity of %P ≥ 35% (i.e., porosity before applying any coating to the clogging cell). In some embodiments, the bare open porosity of the channel wall 206 may be such that 40% ≤ %P ≤ 75%. In other embodiments, the bare open porosity of the channel wall 206 may be such that 45% ≤ %P ≤ 75%, 50% ≤ %P ≤ 75%, 55% ≤ %P ≤ 75%, 60% ≤ %P ≤ 75%, 45% ≤ %P ≤ 70%, 50% ≤ %P ≤ 70%, 55% ≤ %P ≤ 70%, or 60% ≤ %P ≤ 70%.

[0080] Furthermore, in some embodiments, the channel walls 206 of the formed particulate filter 200 have a median pore size ≤30 micrometers before any coating is applied (i.e., in the bare state). For example, in some embodiments, the median pore size may be ≥8 micrometers and less than or ≤30 micrometers. In other embodiments, the median pore size may be ≥10 micrometers and less than or ≤30 micrometers. In other embodiments, the median pore size may be ≥10 micrometers and less than or ≤25 micrometers. In some embodiments, the resulting particulate filter with a median pore size greater than about 30 micrometers has reduced filtration efficiency, while the resulting particulate filter with a median pore size less than about 8 micrometers may make it difficult for a catalyst-containing repair substrate coating to penetrate the pores. Therefore, in some embodiments, it is desirable to maintain the median pore size of the channel walls in the range of about 8 micrometers to about 30 micrometers, for example, in the range of 10 micrometers to about 20 micrometers.

[0081] In one or more embodiments described herein, the clogging honeycomb structure of the particulate filter 200 is formed of a metallic or ceramic material, such as cordierite, silicon carbide, alumina, aluminum titanate, or any other ceramic material suitable for particulate filtration applications at elevated temperatures. For example, the particulate filter 200 can be formed from cordierite by mixing a batch of ceramic precursor materials, which may contain constituent materials suitable for producing ceramic articles (which primarily comprise the cordierite crystalline phase). Generally, constituent materials suitable for forming cordierite include combinations of inorganic components (including talc, sources for forming silica, and sources for forming alumina). The batch composition may additionally contain clay, such as kaolin clay. The cordierite precursor batch composition may also contain organic components (e.g., organic pore-forming agents) added to the batch mixture to achieve the desired pore size distribution. For example, the batch composition may include starch and / or other processing aids suitable for use as pore-forming agents. Alternatively, the constituent materials may include one or more cordierite powders suitable for forming a sintered cordierite honeycomb structure after firing, as well as organic pore-forming materials.

[0082] The batch composition may additionally include one or more processing aids (e.g., binders) and liquid carriers (e.g., water or a suitable solvent). Adding processing aids to the batch mixture plasticizes it and generally improves processing, reduces drying time, reduces post-firing cracking, and / or helps produce the desired plugged honeycomb properties. For example, the binder may include an organic binder. Suitable organic binders include water-soluble cellulose ether binders such as methylcellulose, hydroxypropyl methylcellulose, methylcellulose derivatives, hydroxyethyl acrylate, polyvinyl alcohol, and / or any combination thereof. Incorporating an organic binder into the plasticized batch composition facilitates extrusion of the plasticized batch composition. In some embodiments, the batch composition may include one or more optional forming aids or processing aids, such as lubricants that aid in the extrusion of the plasticized batch mixture. Exemplary lubricants may include tall oil, sodium stearate, or other suitable lubricants.

[0083] After a batch of ceramic precursor material is mixed with appropriate processing aids, the batch of ceramic precursor material is extruded and dried to form a green honeycomb, the green honeycomb including an inlet end and an outlet end, with multiple channel walls extending between the inlet end and the outlet end. The green honeycomb is then fired according to a firing scheme suitable for producing a fired honeycomb. At least a first set of channels in the fired honeycomb can then be plugged with a ceramic plugging composition in a predetermined plugging pattern, and the honeycomb is dried and / or heated to fix the plugging within the channels.

[0084] In various embodiments, the slug-type honeycomb structure is configured to filter particulate matter from an airflow (e.g., exhaust gas from a gasoline engine). Therefore, the median pore size, porosity, geometry, and other design aspects of both the body and surface of the slug-type honeycomb structure are selected to account for these filtration requirements. For example, and as... Figure 4 As shown in the implementation method, (it can be as follows) Figure 2 and 3The wall 310 of the clogged cell 300 (in the form of a particulate filter) has a filter material deposit 320 disposed thereon, which in some embodiments is bonded by heat treatment sintering or any other method. The filter material deposit 320 includes particles 325 deposited on the wall 310 of the clogged cell 300 and helps prevent particulate matter (e.g., soot and ash) from leaving the clogged cell with the airflow 330, and helps prevent particulate matter from clogging the base portion of the wall 310 of the clogged cell 300. In this way, and according to embodiments, the filter material deposit 320 can serve as the primary filter component, while the base portion of the clogged cell can be configured in any other way to minimize pressure drop, for example, compared to a cell without such filter material deposits. The filter material deposits are delivered using the apparatus and deposition methods disclosed herein.

[0085] Compared to the thickness of the base portion of the wall of the plugged honeycomb, the material on the wall of the plugged honeycomb (which may be an inorganic layer in some portions or embodiments) is very thin. The material on the plugged honeycomb (which may be an inorganic layer) can be formed by allowing the deposited material to be applied to the surface of the wall of the plugged honeycomb in a very thin layer or in some portions or layers. In one embodiment, the average thickness of the material (which may be a deposited region or an inorganic layer) on the base portion of the wall of the plugged honeycomb is: greater than or equal to 0.5 µm and less than or equal to 50 µm, or greater than or equal to 0.5 µm and less than or equal to 45 µm, greater than or equal to 0.5 µm and less than or equal to 40 µm, or greater than or equal to 0.5 µm and less than or equal to 35 µm, or greater than or equal to 0.5 µm and less than or equal to 30 µm, greater than or equal to 0.5 µm and less than or equal to 25 µm, or greater than or equal to 0.5 µm and less than or equal to 20 µm, or greater than or equal to 0.5 µm and less than or equal to 15 µm, or greater than or equal to 0.5 µm and less than or equal to 10 µm. In one or more embodiments, the inorganic material comprises alumina.

[0086] See now Figure 5 This illustrates an embodiment of a device 400 configured to apply inorganic particles 407 to a plugged honeycomb. In one or more embodiments, the plugged honeycomb is as follows: Figure 2 and 3 The types shown, and the plugged honeycomb structure includes porous walls, an inlet end, and an outlet end. Figure 5The illustrated device 400 includes a conduit 402 extending from a first end 421 to a second end 422. The device also includes a deposition zone 414 configured to accommodate a plugged honeycomb structure 415 in fluid communication with the second end 422 of the conduit 402. In the illustrated embodiment, the device further includes at least one inlet 403 in fluid communication with the conduit 402, the inlet 403 being located upstream of the deposition zone 414. Figure 5 In the diagram, arrow 401 indicates the direction of flow through device 400 (specifically, conduit 402, deposition zone 414, and plugged cell 415). The term "upstream" refers to the location within the device where the flow is encountered prior to another location within the device. Similarly, the term "downstream" refers to the location within the device where the flow is encountered subsequent to another location within the device. Thus, the first end 421 of conduit 402 encounters the flow through the device prior to the second end 422 of conduit 402, and the second end 422 of conduit 402 encounters the flow through the device prior to deposition zone 414.

[0087] exist Figure 5 In the illustrated embodiment, the apparatus further includes an inorganic particle source 405 in fluid communication with inlet 403. The inorganic particle source 405 is configured to deliver inorganic particles 407 to inlet 403 and to deposition zone 414. According to one or more embodiments, “configured to deliver inorganic particles to inlet and to deposition zone” includes a particle source comprising means or methods for introducing inorganic particles 407 into conduit 402. For example, inlet 403 may be an opening in the wall of conduit 402 and may include a conduit (e.g., a transfer channel), and inorganic particle source 405 may include a container for receiving a quantity of inorganic particles 407. Inorganic particles 407 from the inorganic particle source can be introduced into inlet 403 by gravity feeding, auger, conveyor, or any other suitable means of introducing inorganic particles 407 into conduit 402. The apparatus 400 also includes a flow generator 418 in fluid communication with conduit 402 and deposition zone 414, and is configured to establish flow of fluid and inorganic particles 407 introduced into conduit 402. In one or more embodiments, the fluid is a gas, such as air, nitrogen, or a mixture thereof. Non-limiting examples of the flow generator 418 include a fan, blower, and / or vacuum pump, which establishes a fluid flow (e.g., a gas flow) in the direction of arrow 401. The flow generator 418 is in fluid communication with an outlet chamber 416 and an outlet conduit 420 located downstream of the deposition zone.

[0088] The device 400 also includes a first sampling port 410 located upstream of and in fluid communication with the deposition zone 414. According to one or more embodiments, the first sampling port 410 includes a tube, conduit, or other suitable conduit for transferring a portion of the inorganic particles 407 from the conduit 402. The device 400 also includes a second sampling port 412 located downstream of and in fluid communication with the deposition zone 414. In one or more embodiments, the second sampling port 412 includes a tube, conduit, or other suitable conduit for transferring a portion of the inorganic particles 407 from the outlet chamber 416.

[0089] In such Figure 5 In the illustrated device 400, a particle counter 408 is in fluid communication with a first sampling port and a second sampling port, and the particle counter is configured to count a selected portion of inorganic particles within a pre-selected inorganic particle size range. In a specific embodiment, the particle counter is configured to count inorganic particles 407 upstream and downstream of the deposition zone. Figure 5 As understood, the first sampling port 410 transmits a selected portion of the inorganic particles 407 in the conduit 402 to the particle counter 408. According to one or more embodiments, "selected portion" refers to the portion of the inorganic particles 407 subsequently analyzed by the particle counter 408. According to one or more embodiments, "particle" includes aggregates of individual particles, and "particle size distribution" includes the distribution of aggregates.

[0090] In one or more embodiments, "preselected particle size range" refers to a particle size distribution that is narrower than the particle size distribution of the inorganic particles 407 flowing through the first sampling port and delivered to the particle counter 408. As a non-limiting example, if the particle size distribution of the inorganic particles 407 in the pipe 402 ranges from 0.01 µm to 100 µm, and the preselected particle size range is 0.1 µm to 50 µm, this is a particle size distribution narrower than the particle size distribution of the particles 407 in the pipe 402. In one or more embodiments, the pre-selected particle size range is: 0.1 µm to 50 µm, 0.1 µm to 40 µm, 0.1 µm to 30 µm, 0.1 µm to 20 µm, 0.1 µm to 10 µm, 0.1 µm to 5 µm, 0.1 µm to 4 µm, 0.1 µm to 3 µm, 0.1 µm to 2 µm, 0.1 µm to 1 µm, 0.1 µm to 0.5 µm, 0.2 µm to 50 µm, 0.2 µm to 40 µm, 0.2 µm to 30 µm, 0.2 µm to 20 µm, 0.2 µm to 10 µm, 0.2 µm to 5 µm, 0.1 µm to 4 µm, 0.2 µm to 3 µm, 0.2 µm to 2 µm, 0.2 µm to 1 µm, 0.2 µm to 0.5 µm. µm, 0.3 µm to 50 µm, 0.3 µm to 40 µm, 0.3 µm to 30 µm, 0.3 µm to 20 µm, 0.3 µm to 10 µm, 0.3 µm to 5 µm, 0.3 µm to 4 µm, 0.3 µm to 3 µm, 0.3 µm to 2 µm, 0.3 µm to 1 µm, or 0.3 µm to 0.5 µm.

[0091] According to one or more embodiments, particle counter 408 includes any type of particle counter capable of counting particles within the range provided above. Non-limiting examples of particle counters include: optical spectrometers (e.g., spectrometers such as the Palas® Promo® 2000 from Palas Corporation (https: / / www.palas.de / en / )), engine exhaust particle size analyzers, particle size spectrometers, scanning migration particle size analyzers, or condensed particle counters.

[0092] In some embodiments, upstream sampling occurs. In one or more embodiments, the device 400 further includes an inorganic particle concentration dilution device 406 upstream of the particle counter 408 and downstream of the first sampling port 410, the inorganic particle concentration dilution device 406 being configured to reduce the inorganic particle concentration at the first sampling port before the inorganic particles 407 flow toward the particle counter 408. In the illustrated embodiment, the inorganic particle concentration dilution device 406 includes a dilution chamber or container. The device may also include a gas supply 404, such as air or nitrogen in fluid communication with the inorganic particle concentration dilution device 406, thereby reducing the concentration of inorganic particles 407 in the conduit 402 to a lower concentration (in units of weight per unit volume, e.g., g / cm³ or g / L). Figure 5 The diagram only shows the upstream dilution gas supply 404; no downstream dilution gas supply is shown. In one or more embodiments, the dilution chamber is configured to provide a gas-particle ratio of 20:1 to 100:1 or 70:1 to 100:1 within the dilution chamber. Other suitable gas-particle ratio ranges include: 10:1 to 100:1, 20:1 to 100:1, 30:1 to 100:1, 40:1 to 100:1, 50:1 to 100:1, 60:1 to 100:1, 70:1 to 100:1, 80:1 to 100:1, and 90:1 to 100:1. In some embodiments, upstream sampling is not diluted. In some embodiments, downstream sampling is not diluted. In some embodiments, both upstream and downstream sampling are not diluted. In some implementations, dilution is provided if the particle concentration in the sampling pipeline is too high relative to the sensitivity of the particle counter; therefore, in some implementations, dilution is provided at both upstream and downstream ports, with no port providing dilution, or any combination of both (upstream only, or downstream only): if the particle concentration at either port is too high.

[0093] In some embodiments, the dilution device 406 includes a splitter connection that provides a gas-particle ratio of 20:1 to 100:1 within the dilution chamber. In some embodiments, the dilution device includes a splitter connection that provides a gas-particle ratio of 70:1 to 100:1 within the dilution chamber. Other suitable gas-particle ratio ranges include: 10:1 to 100:1, 20:1 to 100:1, 30:1 to 100:1, 40:1 to 100:1, 50:1 to 100:1, 60:1 to 100:1, 70:1 to 100:1, 80:1 to 100:1, and 90:1 to 100:1. In some specific embodiments, the dilution device 406 includes a commercially available dilution device, such as the LDD 100 from Palas (https: / / www.palas.de / en / ).

[0094] In one or more embodiments, device 400 further includes processor 450 configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the deposition zone and nd = the number of inorganic particles downstream of the deposition zone. In one or more embodiments, processor 450 may be integrated with or separate from particle counter 408. In some embodiments, the processor includes a central processing unit (CPU), memory, and support circuitry. Processor 450 may be one of any form of general-purpose computer processor in an industrial setting capable of counting particles and performing calculations across different particle size ranges. The memory or computer-readable medium of processor 450 can be one or more of the following: easily readable memory (e.g., random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, optical storage medium (e.g., optical disc or digital video disc), flash drive, or any other form of local or remote digital storage). Supporting circuitry is connected to the CPU to support processor 450 in a conventional manner. This circuitry includes: cache, power supply, clock circuitry, input / output circuitry, and subsystems, etc. One or more processes can be stored in memory as software routines that can be executed or invoked to control the operation of particle counter 408 in the manner described herein.

[0095] In one or more embodiments, the inorganic particle source 405 is in fluid communication with the atomizing nozzle 440. In one or more embodiments including the atomizing nozzle 440, the fluid is a gas, and the atomizing nozzle is in fluid communication with a liquid source 430 and a binder 432, the binder 432, the liquid source 430, and the inorganic particle source 405 configured to flow through the atomizing nozzle 440 to form an aerosol. It will be understood that the device 400 can be constructed in various ways. For example, although two separate inlets 403 and atomizing nozzles 440 are shown, any number of inlets 403 and atomizing nozzles can be present. For example, there can be one, two, three, four, five, or more atomizing nozzles and inlets 403, respectively. Although Figure 1 The liquid source 430 and the binder source 432 are shown to be separate, but it will be understood that inorganic particles can be mixed with binders and liquids (e.g., water or alcohols (e.g., ethanol)) in the inorganic particle source 405.

[0096] Another aspect of this disclosure pertains to a method for applying inorganic particles to a plugged honeycomb containing porous walls, an inlet end, and an outlet end. The method includes: causing inorganic particles to flow from a first end of a conduit to a second end of the conduit into a plugged honeycomb in fluid communication with the second end of the conduit; sampling a portion of the inorganic particles from a sampling port (located upstream of and in fluid communication with the plugged honeycomb) and sampling a portion of the inorganic particles from a second sampling port (located downstream of and in fluid communication with the plugged honeycomb); and counting the inorganic particles from a selected portion of the inorganic particles from the first and second sampling ports, the selected portion being within a pre-selected range of inorganic particle sizes. This can be done in any suitable device (e.g., such as...). Figure 1 The method is performed in the device 400 shown. In some embodiments, counting is performed using a particle counter. In some embodiments, a flow generator in fluid communication with a pipe and a plugged cell is used to generate the flow of inorganic particles, which is configured to establish the flow of fluid with the inorganic particles. The flow generator can be any type of flow generator described above. In one or more embodiments, the pre-selected range of inorganic particle sizes is within the range provided above. In one or more embodiments, the particle counter can be any particle counter described above.

[0097] In some embodiments, the method includes diluting the particle stream upstream of the particle counter and downstream of the first sampling port to reduce the concentration of inorganic particles at the first sampling port before flowing to the particle counter. The reduction in inorganic particle concentration can occur in any of the dilution devices 406 described above and can be any of the dilution ranges described above, such as 20:10 to 100:1 or 70:1 to 100:1. In some embodiments, no dilution is performed during upstream sampling. In some embodiments, no dilution is performed during downstream sampling. In some embodiments, neither upstream nor downstream sampling is diluted. In some embodiments, dilution is provided if the particle concentration in the sampling pipeline is too high relative to the particle counter sensitivity; therefore, in some embodiments, dilution is present at both the upstream and downstream ports, with no port providing dilution, or any combination (upstream only, or downstream only): if the particle concentration at either port is too high.

[0098] In some implementations, the method further includes calculating the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the deposition zone and nd = the number of inorganic particles downstream of the deposition zone. This calculation can be performed using the processor described above regarding the device.

[0099] In one or more embodiments, inorganic particles flow through an atomizing nozzle. In one or more embodiments, the fluid of the method is a gas, and inorganic particles and liquid with a binder flow through the atomizing nozzle to form an aerosol.

[0100] Known measurement systems for measuring the filtration efficiency of clogged cell filters (e.g., GPF) generate particles ranging from 10 nm to 0.5 μm by producing soot via a combustion device and using a blower to push the generated particles through an unclogged substrate. Particle concentrations of a specific particle diameter are recorded at sampling ports equipped with particle counting instruments (SMPS, EEPS, etc.) at the front and rear of the component. Typically, air filtration efficiency is calculated as follows:

[0101] μ e =n t / n u =(n u -n d ) / n u (1)

[0102] Where μ e =Air filter efficiency, n t =Captured particles, n u =Upstream particles, and n d =Downstream particles.

[0103] While the claimed content of this disclosure should not be limited to specific operating theories, various embodiments of interest may apply to porous filters (e.g., such as...). Figure 6A and 6B The GPF (Glass Filter Form) shown in the diagram appears to employ a combination of three particle capture mechanisms to achieve filtration and thus influence filtration efficiency: interception, impaction, and diffusion (depending on particle size). Smaller particles are captured by diffusion, while larger particles are captured by interception and impaction. Therefore, the initial filtration efficiency of a new GPF will vary depending on the particle size delivered to the filter body. Consequently, both smaller and larger particles are captured through the filter body, while lower filtration efficiency is observed for particles with a diameter of approximately 200 nm.

[0104] According to one or more embodiments, the GPF filter can be modified by surface treatment as follows: by depositing small inorganic particles or agglomerates of inorganic particles (e.g., alumina powder); in some embodiments, a binder (e.g., organic or inorganic binder) is also deposited on and / or into the walls of the GPF filter. Because the agglomerates are deposited on the filter's inlet channel, they can alter the porosity of the channel wall's microstructure. During the accumulation of agglomerates, the filter's filtration efficiency increases from a baseline (no deposition) value (e.g., 50%) to a target value required for the application (e.g., greater than 90%).

[0105] According to one or more embodiments, relative to such Figure 5 The apparatus described herein and the methods described herein may include spraying and drying inorganic particles (e.g., alumina particles) and binders in an ethanol or water suspension using at least one nozzle operating under high pressure. Once the suspension containing inorganic particles is sprayed from the nozzle into a heated chamber to form an aerosol, the particles or agglomerates are dried, for example, having a particle size distribution range of about 0.01 µm to about 50 µm. The dried particles and / or agglomerates are then carried through pipes and deposited into and / or onto the porous walls of a plugged honeycomb structure.

[0106] The description will now be as follows: Figure 5 Specific embodiments of the process performed in the illustrated apparatus are described. It will be understood that while the described specific embodiments pertain to the formation of aerosols from a suspension comprising inorganic particles, solvents, and binders, this disclosure is not limited to such processes. For example, a dry aerosol process may be employed. In other embodiments, the inorganic particles may be fed directly into… Figure 5 The device 00 is introduced into inlet 430. In other embodiments, inorganic particles are introduced into the filter body without a binder.

[0107] Commercially available inorganic particles can be used as raw materials in mixtures forming inorganic materials for deposition. According to one or more embodiments, the particles are selected from: Al₂O₃, SiO₂, TiO₂, CeO₂, ZrO₂, SiC, MgO, and combinations thereof. In one or more embodiments, the mixture is a suspension. The particles can be supplied as raw materials suspended in a liquid carrier, to which other liquid carriers can optionally be added.

[0108] In some embodiments, the liquid carrier is an alcohol (e.g., ethanol). In other embodiments, the liquid is water. In some embodiments, both water and an alcohol constitute the liquid carrier. Therefore, in some embodiments, the mixture is aqueous; for example, the liquid carrier of the suspension may be water. In other embodiments, the mixture is organic; for example, the liquid carrier of the mixture may be an alcohol, such as ethanol or methanol, or a combination thereof. In one or more embodiments, the vapor pressure of the liquid carrier is greater than the vapor pressure of water at the temperature of the gaseous carrier stream. In one or more embodiments, the liquid carrier is substantially composed of a material whose boiling point at the temperature of the gaseous carrier stream is lower than that of water. In one or more embodiments, the liquid carrier is an alcohol. In one or more embodiments, the liquid carrier is: methoxyethanol, ethanol, xylene, methanol, ethyl acetate, benzene, or a mixture thereof. In one or more embodiments, the liquid carrier is an alcohol. In one or more embodiments, the liquid carrier is substantially composed of water.

[0109] In some embodiments, the suspension comprises, by weight, 5-20% particles and 80-95% liquid, and all values ​​and sub-ranges thereof. In one embodiment, the suspension comprises, by weight, 11% ± 1% alumina and 89% ± 1% ethanol.

[0110] In one or more embodiments, the median first-order particle size is in the following ranges: about 10 nm to about 4 micrometers, about 20 nm to about 3 micrometers, or about 50 nm to about 2 micrometers, or about 50 nm to about 900 nm, or about 50 nm to about 600 nm. In specific embodiments, the median first-order particle size range is about 100 nm to about 200 nm, for example, 150 nm. The median first-order particle size can be determined as a calculated value from the BET surface area of ​​the aerosol particles (which is currently about 10 m² / g in some embodiments).

[0111] In one or more embodiments, the primary particles include ceramic particles, such as oxide particles, for example: Al2O3, SiO2, MgO, CeO2, ZrO2, CaO, TiO2, cordierite, andalusite, SiC, aluminum titanate, and mixtures thereof.

[0112] If necessary, the suspension can be diluted with a solvent to form a mixture. If the droplets produced by atomization are of similar size, reducing the solids content in the mixture can proportionally reduce the aggregate size. The solvent should be miscible with the suspension mentioned above and should be a solvent used for binders and other components.

[0113] Optional binders are added to enhance agglomerates and preferably provide tackiness or adhesiveness, and inorganic binders may be included to provide mechanical integrity to the deposited material. The binders provide interparticle bonding strength at elevated temperatures (>500°C). The starting materials can be organic. After exposure to temperatures exceeding approximately 150°C, organic starting materials decompose or react with moisture and oxygen in the air, and the final deposited material composition may contain Al₂O₃, SiO₂, MgO, CeO₂, ZrO₂, CaO, TiO₂, cordierite, andalusite, SiC, aluminum titanate, and mixtures thereof.

[0114] A catalyst can be added to accelerate the curing reaction of the adhesive. An example catalyst content is 1% by weight of the adhesive.

[0115] The mixing or suspension being stored and / or awaiting delivery to the nozzle can be agitated using desired stirring techniques. In one or more embodiments, stirring is performed in a mechanical stirrer. In these embodiments, the use of a mechanical stirrer facilitates the reduction and / or elimination of potential contamination from the plastic-coated mixing rods that come into contact with the container in a magnetic stirring system.

[0116] In some implementations, the mixture is atomized into fine droplets by passing high-pressure gas through a nozzle. An example nozzle is the 1 / 4J-SS+SU11-SS from Spraying Systems Co. This setup includes a nozzle body, a fluid cap, and an air cap. The atomizing gas contributes to breaking down the liquid-particle-binder stream into droplets.

[0117] In one or more embodiments, the nozzle described herein is an internally mixing nozzle, such as an internally mixing nozzle whose part numbering is given above. In one or more embodiments, the nozzle described herein is an externally mixing nozzle, such as the externally mixing nozzle configuration of a spray system: 1 / 4J-SS+SU1A, which consists of an air cap and a fluid cap. Another available configuration consists of an air cap and a fluid cap. Externally mixing nozzles are advantageous for achieving smaller particle sizes with a more compact particle size distribution, which improves material utilization and filtration efficiency. In one or more embodiments, the nozzle herein is a converging nozzle. As used herein, a converging nozzle refers to a nozzle having a fluid flow channel whose cross-sectional area decreases from inlet to outlet, thereby accelerating fluid flow. Converging nozzles can be internally mixing or externally mixing.

[0118] In one or more embodiments, liquid-particle-binder droplets are directed into the chamber via a nozzle.

[0119] In one or more embodiments, liquid-particle-binder droplets are guided into a chamber through multiple nozzles. In one or more embodiments, multiple liquid-particle-binder streams are atomized through multiple atomizing nozzles. The multiple nozzles may include: 2 or more nozzles, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, and 10 or more, etc. The multiple nozzles may be evenly spaced within the chamber. In one or more embodiments, the multiple nozzles are each angled toward the center of the device. The nozzle angles may be acute angles, ranging from less than 90° to greater than 10° relative to the sidewall of the device, and all values ​​and sub-ranges therebetween, including 20° to 45°.

[0120] The pressure range of the atomizing gas can be from 20 psi to 150 psi. The pressure range of the liquid can be from 1 to 100 psi. The average droplet size according to one or more embodiments can be in the range of 1 micrometer to 40 micrometers, including, for example: greater than or equal to 1 micrometer to less than or equal to 15 micrometers, greater than or equal to 2 micrometers to less than or equal to 8 micrometers, greater than or equal to 4 micrometers to less than or equal to 8 micrometers, and greater than or equal to 4 micrometers to less than or equal to 6 micrometers, and all values ​​and sub-ranges therebetween. The droplet size can be adjusted by adjusting the surface tension of the mixture, the viscosity of the mixture, the density of the mixture, the gas flow rate, the gas pressure, the liquid flow rate, the liquid pressure, and the nozzle design. In one or more embodiments, the atomizing gas includes nitrogen. In one or more embodiments, the atomizing gas can be substantially composed of an inert gas. In one or more embodiments, the atomizing gas can be primarily one or more inert gases. In one or more embodiments, the atomizing gas can be primarily nitrogen. In one or more embodiments, the atomizing gas can be primarily air. In one or more embodiments, the atomizing gas can be substantially composed of nitrogen or air. In one or more embodiments, the atomizing gas can be dry. In one or more embodiments, the atomizing gas may contain substantially no liquid carrier after entering the chamber.

[0121] In some implementations, the suspension flow rate ranges from 10 to 25 g / min, including all values ​​and subranges therebetween, including 18 g / min.

[0122] In some implementations, the atomizing gas fluid nitrogen flow rate ranges from 2 to 10 Nm3 / h, including all values ​​and sub-ranges therebetween, including 5-6 Nm3 / h.

[0123] The flow of the suspension and the corresponding agglomerate size can be controlled by a pressure control system or a flow control system suitable for the equipment. For a pressure control system, a pressure controller is connected to a delivery conduit (e.g., a tube or pipe), into which the suspension of primary particles in the liquid is introduced and then flows to the nozzle. For a flow control system, a syringe pump is provided that delivers the suspension of primary particles in the liquid to the nozzle. Typically, the atomizing gas is supplied to the nozzle separately. In a preferred embodiment, the pump guides the liquid-particle-binder mixture to the atomizing nozzle at a substantially constant flow rate. A constant flow rate is advantageous rather than maintaining a constant pressure because it helps reduce variability in particle size, which in turn improves material utilization.

[0124] In one or more embodiments, the suspension comprises: an inorganic material, a liquid carrier, and preferably a binder, supplied to a nozzle as a liquid-particle-binder stream. That is, particles of the inorganic material can be mixed with the liquid carrier and the binder material to form the liquid-particle-binder stream. The liquid-particle-binder stream is atomized into liquid-particle-binder droplets through the nozzle by an atomizing gas. In one or more embodiments, the liquid-particle-binder stream is mixed with the atomizing gas. In one or more embodiments, the liquid-particle-binder stream is guided into an atomizing nozzle, thereby atomizing the particles into liquid-particle-binder droplets. The liquid-particle-binder droplets comprise a liquid carrier, a binder material, and particles.

[0125] In one or more embodiments, the liquid-particulate-binder stream is mixed with the atomizing gas via an atomizing nozzle. In one or more embodiments, the liquid-particulate-binder stream enters the atomizing nozzle. In one or more embodiments, the mixing of the liquid-particulate-binder stream and the atomizing gas occurs within the atomizing nozzle. In one or more embodiments, the mixing of the liquid-particulate-binder stream and the atomizing gas occurs outside the atomizing nozzle.

[0126] According to one or more embodiments, the online filtration efficiency of the filter is directly measured during the deposition process. In some embodiments, to perform this measurement, the concentrations of inorganic particles (including agglomerates) upstream and downstream of the GPF are directly measured during the deposition process and the real-time filter efficiency (FE) is calculated using Equation 1. In one or more embodiments, the inorganic particle size distribution is similar to that of soot particles used for standard offline FE measurements, and inorganic particles sampled from the device 400 in this manner can be used. Using the embodiments described herein and the device, the controller can stop the deposition process once the FE target is reached. This technique provides closed-loop control of the inorganic particle deposition process, thereby ensuring minimal selection loss.

[0127] Figure 7 Shown during the experiment Figure 5 The representative particle size distribution (PSD) of agglomerates upstream and downstream of the plugged honeycomb structure placed in the deposition zone of the device shown. The particle size distribution of inorganic particle agglomerates is generated through a spray drying nozzle upstream of the plugged honeycomb structure. FE measurements of the GPF filter in the 0.3–0.5 µm particle size range can be advantageously performed. Figure 7 It can be seen that this process produces a large number of particles falling within this size range. Figure 7 The particle size distribution downstream of the plugged honeycomb structure during the deposition process is also shown. For example... Figure 7As shown, the number of particles available in the 0.3–0.5 µm range is reduced because the plugged honeycomb structure filters out many of these particles (which are deposited on and / or within the inner walls of the GPF channels).

[0128] The component FE during operation can be calculated using Equation 1 and measurements of the total particle concentration upstream and downstream of the plugged cell during the deposition process. Figure 8 This displays the stability of the total particle count measured in pipe 402 upstream of the blocked cellular structure. Figure 8 In this study, the total particle concentration was measured throughout the entire time it takes for inorganic particles to deposit into a plugged honeycomb structure. Measurement stability was acceptable for in-line FE measurements. Measurements were taken using an optical spectrometer sampling particles upstream of the component. Figure 8 The data is presented in the figure. The particle size range included in the total particle concentration is 0.1 µm–10 µm. As shown in this figure, the concentration of inorganic particle agglomerates remained stable during the deposition process of approximately 380 seconds. The circles represent the particle concentration, while the lines represent the time taken for the nozzle to flow liquid and spray the suspension of dried binder, ethanol, and inorganic particles.

[0129] Figure 9 The same total particle count measurements are shown upstream and downstream during the coating of a single plugged cell in the deposition process. The (diluted) upstream concentration was measured for the first 60 seconds, then the aerosol spectrometer was switched to monitor the downstream particle concentration (see [link]). Figure 5 An online FE process can use a single particle counter (with a valve to switch between upstream and downstream concentrations) or two separate particle counters dedicated to upstream and downstream sampling. When using a single particle counter, it is assumed that the upstream particle concentration is stable throughout the deposition time, even after the counter is switched to the downstream port.

[0130] Figure 9 This displays the process particle concentration upstream (0-60 seconds) and downstream (60-420 seconds) of the clogging honeycomb structure during the deposition process. From the part onwards (that is,...) Figure 5 Data were obtained using an optical spectrometer that sampled the deposition process downstream of the deposition zone. The particle size range included in the total particle concentration is 0.1 µm–10 µm. As the clogging honeycomb deposits particulate material, the particle concentration downstream of the component decreases. Solid lines indicate the time it takes for the spray nozzle to allow liquid and particulates to flow and generate agglomerates.

[0131] Using the total particle concentration measured upstream and downstream of the blocked honeycomb structure, Equation 1 can be used to measure the online FE in the process. Figure 10In the figure, the solid circle curves show the results of this calculation during the deposition process running at all particle sizes (diameters). The plotting begins at the 60-second mark of the deposition process as the particle counter switches from upstream to downstream. Online FE values ​​are recorded as the process continues to deposit inorganic particles onto the clogging cell (thus increasing the filtration efficiency of the GPF). This is recorded directly using the particle counter. The online FE of the bare GPF starts at approximately 70%, and continues to increase as the APT process progresses. At 60 seconds, the FE measurements for all PSD column vectors (bins) have increased to 90% of the online FE scale. At the end of the process (approximately 330 seconds), the online FE has increased to approximately 99%.

[0132] exist Figure 10 In this process, real-time particle effusion (FE) measurements are performed using the measured upstream and downstream particle concentrations and Equation 1. Upstream measurements are taken during the first 60 seconds, and downstream measurements are taken after 60 seconds. The final FE for each component is calculated using the average of the last 10 seconds of the online FE curve. Data is displayed using the total particle count for all particle size column vectors within the measurement range (0.1 µm–10 µm) and specific column vectors (0.3 µm–0.7 µm column vectors).

[0133] Figure 10 The results of online FE measurements using a selected number of PSD column vectors (particle size ranges) from the aerosol spectrometer, rather than all column vectors, are also shown. Because the slugging cellular structure filters different particle sizes with varying efficiencies, online FE measurements can be customized to select column vectors (particle size ranges), providing optimal correlation with offline FE measurement systems and offering the best stability and repeatability. Regression analysis was performed to determine the optimal combination of particle sizes that maximizes correlation with offline systems and reduces variability in measurements.

[0134] Experiments were conducted in which 24 components were run through the deposition process, at four different load levels across six different components. The load range was designed to cover a wide range of filtration efficiencies from 65% to 95% based on the offline flue gas FE measurement system. Using all PSD column vectors from the aerosol spectrometer, the final online FE measurement was calculated for each unclogged cell and compared with the measured offline FE system. The results are presented in… Figure 7In the online FE measurement, the correlation between the online FE system and the flue gas FE system was approximately 93% when all particle diameters were included. After optimization studies, a better correlation was obtained by selecting only the peak inorganic particle size of 0.45 μm (based on the total count in pipe 402) and selecting the two column vectors to the right of this peak and the coordinates (approximately + / - 0.2 μm). By adopting this optimized PSD range, the online FE measurement produced a better correlation (95% vs 93%) compared to the offline flue gas FE system; a wider FE range (87%-99% vs 92%-99%), which improved the resolution of the online FE measurement; and maintained acceptable measurement repeatability. The repeatability (1) of the online FE measurement was approximately 0.5%.

[0135] Figure 11 The results of an optimization study using different granularity distributions to determine the correlation between online FE and flue gas FE are also shown. The correlation between the online FE system and the flue gas FE system can be optimized depending on the selected granularity range. In this figure, it is shown that the online FE measurement based on the PSD peak (0.45 µm) + / - 2 column vectors (approximately + / - 0.2 µm) achieved the best correlation (95%) with the offline flue gas FE measurement.

[0136] Because the high levels of particle concentration in the deposition process pipe 402 are too high even for the highest-end commercially available particle counter systems, upstream measurements utilize the dilution device described above. The dilution ratio is determined by monitoring the overlap from the particle counter while adding more diluent nitrogen to the mixing valve. Similarly, daily cleaning is required due to the high concentration of contamination on the particle counter optics. However, through regular preventative maintenance of the facility, the team is able to operate it for months without issues.

[0137] Therefore, in various embodiments, the methods and apparatus disclosed herein can help achieve the target filtration efficiency when inorganic particles are deposited on and / or in the porous walls of a plugged honeycomb structure.

[0138] Throughout this specification, the terms "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" refer to specific features, structures, materials, or characteristics described in connection with an embodiment that are included in at least one embodiment of this disclosure. Therefore, phrases appearing in various places throughout this specification, such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," do not necessarily refer to the same embodiment of this disclosure. Furthermore, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments.

[0139] Although the disclosure herein has been described in conjunction with specific embodiments, those skilled in the art will understand that the described embodiments are merely illustrative of the principles and applications of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the scope and spirit of this disclosure. Therefore, this disclosure includes modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. An apparatus for increasing the filtration efficiency of a porous honeycomb filter comprising a plugged honeycomb cell containing porous walls, an inlet end, and an outlet end, the apparatus being configured to apply inorganic particles to the plugged honeycomb cell containing porous walls, an inlet end, and an outlet end, the apparatus comprising: A pipe that spans from the first end to the second end; A deposition zone is constructed to accommodate plug-type honeycomb structures, which is in fluid communication with the second end of the pipe; An inlet in fluid communication with a pipeline, the inlet being located upstream of the deposition zone; An inorganic particle source in communication with the inlet fluid is configured to deliver inorganic particles to the inlet and to the deposition zone; A flow generator in fluid communication with a pipe and a sedimentation zone, configured to establish a flow of fluid and inorganic particles introduced into the pipe; The first sampling port is located upstream of the sedimentary area and is in fluid communication with it; A second sampling port located downstream of and in fluid communication with the sedimentary area; and A particle counter in fluid communication with a first sampling port and a second sampling port is configured to count a selected portion of inorganic particles within a pre-selected range of inorganic particle sizes.

2. The device as claimed in claim 1, wherein, The particle counter is configured to count inorganic particles upstream and downstream of the sedimentation zone.

3. The device as described in claim 2, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 10 µm.

4. The device as claimed in claim 2, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 1 µm.

5. The device as claimed in claim 2, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 0.5 µm.

6. The device as claimed in claim 2, wherein, The pre-selected inorganic particle size range is from 0.3 µm to 0.5 µm.

7. The device as claimed in claim 2, wherein, Particle counters include optical spectrometers.

8. The device as claimed in claim 2, wherein, Particle counters include engine exhaust particle size analyzers and spectrometers.

9. The device as claimed in claim 2, wherein, The particle counter includes a scanning migration particle size analyzer.

10. The device as claimed in claim 2, wherein, Particle counters include agglomerated particle counters.

11. The apparatus of claim 2, further comprising an inorganic particle concentration dilution device located upstream of the particle counter and downstream of the first sampling port, the inorganic particle concentration dilution device being configured to reduce the inorganic particle concentration at the first sampling port before flowing to the particle counter.

12. The device as claimed in claim 11, wherein, The inorganic particle concentration dilution device includes a dilution chamber configured to provide a gas-particle ratio of 20:1 to 100:1 within the dilution chamber.

13. The device as claimed in claim 12, wherein, The dilution chamber is configured to provide a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

14. The device as claimed in claim 13, wherein, The dilution chamber includes a split connection that provides a gas-particle ratio of 20:1 to 100:1 within the dilution chamber.

15. The device as claimed in claim 13, wherein, The dilution chamber includes a split connection that provides a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

16. The device as claimed in claim 2, wherein, The device also includes a processor configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the deposition zone and nd = the number of inorganic particles downstream of the deposition zone.

17. The device as claimed in claim 1, wherein, The inorganic particle source is in fluid communication with the atomizing nozzle.

18. The device as claimed in claim 17, wherein, The fluid is a gas, and the atomizing nozzle is in fluid communication with the fluid source and the binder, wherein the binder, liquid and inorganic particulate source are configured to flow through the atomizing nozzle to form an aerosol.

19. The device as claimed in claim 2, wherein, The flow generator includes a fan.

20. An apparatus for increasing the filtration efficiency of a porous honeycomb filter comprising a plugged honeycomb cell containing porous walls, an inlet end, and an outlet end, the apparatus comprising: A pipe that spans from the first end to the second end; A deposition zone is constructed to accommodate plug-type honeycomb structures, which is in fluid communication with the second end of the pipe; An inlet in fluid communication with a conduit, the inlet being located upstream of the deposition zone; and Inorganic particle source, liquid source and binder, which are in communication with the inlet fluid and configured to deliver a mixture of inorganic particles, liquid and binder to the atomizing nozzle and to the deposition zone; A flow generator in fluid communication with a pipe and a sedimentation zone, configured to establish a flow of fluid and inorganic particles introduced into the pipe; The first sampling port is located upstream of the sedimentary area and is in fluid communication with it; A second sampling port located downstream of the sedimentation zone and in fluid communication with it; A particle counter in fluid communication with a first sampling port and a second sampling port is configured to count a selected portion of inorganic particles within a pre-selected range of inorganic particle size in the upstream and downstream areas of the sedimentation zone. as well as The processor is configured to calculate the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, where nu = the number of inorganic particles upstream of the deposition zone and nd = the number of inorganic particles downstream of the deposition zone.

21. A method for applying inorganic particles to a plugged honeycomb comprising a porous wall, an inlet end, and an outlet end, the method comprising: This allows inorganic particles to flow from the first end of the pipe to the second end, reaching the blockage-type honeycomb structure. A portion of inorganic particles is sampled from a first sampling port and a second sampling port, the first sampling port being located upstream of and in fluid communication with the blocked honeycomb structure, and the second sampling port being located downstream of and in fluid communication with the blocked honeycomb structure; and Inorganic particles from a selected portion of the sample from the first sampling port and the second sampling port are counted, wherein the selected portion of inorganic particles is within a pre-selected range of inorganic particle size.

22. The method of claim 21, wherein, Counting is performed using a particle counter.

23. The method of claim 22, wherein, A flow generator is used to generate the flow of inorganic particles by means of a flow generator that is in fluid communication with pipes and a plugged cellular structure. The structure is configured to establish the flow of fluid and inorganic particles.

24. The method of claim 23, wherein, The fluid includes gas, and the flow generator includes a fan.

25. The method of claim 22, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 10 µm.

26. The method of claim 22, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 1 µm.

27. The method of claim 22, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 0.5 µm.

28. The method of claim 22, wherein, The pre-selected inorganic particle size range is from 0.3 µm to 0.5 µm.

29. The method of claim 22, wherein, Particle counters include optical spectrometers.

30. The method of claim 22, wherein, Particle counters include engine exhaust particle size analyzers and spectrometers.

31. The method of claim 22, wherein, The particle counter includes a scanning migration particle size analyzer.

32. The method of claim 22, wherein, Particle counters include agglomerated particle counters.

33. The method of claim 22, further comprising diluting the particle stream upstream of the particle counter and downstream of the first sampling port to reduce the concentration of inorganic particles at the first sampling port before flowing to the particle counter.

34. The method of claim 33, wherein, The particle stream is diluted in a dilution chamber configured to provide a gas-particle ratio of 20:1 to 100:

1.

35. The method of claim 34, wherein, The dilution chamber is configured to provide a gas-particle ratio of 70:1 to 100:1 within the dilution chamber.

36. The method of claim 34, wherein, The dilution of the particle stream involves splitting the particle stream to provide a gas-particle ratio of 20:1 to 100:1 in the dilution chamber.

37. The method of claim 34, wherein, The dilution of the particulate stream involves splitting the particulate stream to provide a gas-particle ratio of 70:1 to 100:1 in the dilution chamber.

38. The method of claim 22, further comprising calculating the percentage of inorganic particles captured by the clogging cell based on the equation (nu-nd) / nu, wherein, nu = the number of inorganic particles upstream of the honeycomb structure, and nd = the number of inorganic particles downstream of the blockage honeycomb structure.

39. The method of claim 21, wherein, Inorganic particles flow through the atomizing nozzle.

40. The method of claim 39, wherein, The fluid is a gas, as well as inorganic particles and liquids with a binder flowing through an atomizing nozzle to form an aerosol.

41. A method for increasing the filtration efficiency of a porous honeycomb filter comprising a plugged honeycomb body including a porous wall, an inlet end, and an outlet end, the method comprising: This allows the inlet flow of inorganic particles to enter the inlet end of the blockage honeycomb structure; The number of inlets for selected portions of inorganic particles entering a blockage-type honeycomb structure is counted; The number of inorganic particles exiting a selected portion of the outlet flow from the blockage-type honeycomb is counted. In this process, inorganic particles that enter the clogging honeycomb structure but do not leave it are deposited on the porous wall of the honeycomb structure and / or deposited into the porous wall of the honeycomb structure, thereby increasing the filtration efficiency of the clogging honeycomb structure as the deposition continues. The filtration efficiency of a clogging honeycomb structure with deposited particles is determined based on the number of inlets and outlets; and The flow of inorganic particles entering the inlet of the clogging cell is terminated based on the determined filtration efficiency.

42. The method of claim 41, wherein, The selected portion for counting the number of inlets is within a pre-selected range of inorganic particle sizes.

43. The method of claim 41, wherein, The selected portion for counting export quantities is within a pre-selected range of inorganic particle sizes.

44. The method of claim 41, wherein, The pre-selected range of inorganic particle sizes for counting the number of inlets and outlets is the same for the selected portion.

45. The method of claim 42, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 10 µm.

46. ​​The method of claim 42, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 1 µm.

47. The method of claim 42, wherein, The pre-selected inorganic particle size range is from 0.1 µm to 0.5 µm.

48. The method of claim 42, wherein, The pre-selected inorganic particle size range is from 0.3 µm to 0.5 µm.

49. The method of claim 41, wherein, The inlet flow also contains fluid.

50. The method of claim 49, wherein, The fluid is a gas.

51. The method of claim 41, wherein, Counting is performed using a particle counter.

52. The method of claim 51, wherein, Particle counters include optical spectrometers.

53. The method of claim 51, wherein, Particle counters include engine exhaust particle size analyzers and spectrometers.

54. The method of claim 51, wherein, The particle counter includes a scanning migration particle size analyzer.

55. The method of claim 51, wherein, Particle counters include agglomerated particle counters.

56. The method of claim 41, wherein, The inlet flow contains aerosolized particles.

57. The method of claim 41, wherein, The inlet number is obtained from the diluted portion of the inlet flow that is directed into the particle counter.

58. The method of claim 57, wherein, The dilution portion has a gas-particle ratio of 20:1 to 100:

1.

59. The method of claim 57, wherein, The dilution portion has a gas-to-particle ratio of 70:1 to 100:

1.

60. The method of claim 41, wherein, The exit quantity is obtained from the diluted portion of the exit stream that is directed into the particle counter.

61. The method of claim 41, wherein, The termination also includes stopping the flow of inorganic particles into the inlet end of the blockage honeycomb after the filtration efficiency has reached the target filtration efficiency.

62. The method of claim 41, wherein, The termination also includes terminating the flow of the inlet stream of inorganic particles into the inlet end of the blockage cell after the filtration efficiency has not reached the target filtration efficiency within the target deposition time.

63. The method of claim 41, wherein, The termination also includes terminating the inlet flow of inorganic particles into the inlet end of the blockage cell if the number of outlets exceeds the maximum number of outlets.

64. The method of claim 41, wherein, The termination also includes terminating the inlet flow of inorganic particles into the inlet end of the plugged cell if the number of outlets exceeds the maximum number of outlets within the target deposition time.

65. The method of claim 41, wherein, A clogging cell includes inorganic particles deposited in and / or on the porous wall before an inlet flow of inorganic particles enters the inlet end of the clogging cell, wherein the flow of the inlet flow increases the amount of inorganic particles captured by the clogging cell.

66. The method of claim 41, wherein, Before the inlet flow of inorganic particles enters the inlet end of the plugged honeycomb, the plugged honeycomb does not contain inorganic particles deposited in and / or on the porous wall, wherein the flow of the inlet flow introduces inorganic particles into the plugged honeycomb.

67. The method of claim 41, wherein, Determining the filtration efficiency μe involves calculating the ratio of (number of inlets - number of outlets) / (number of inlets).

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