Powder spray system, powder spray nozzle and method

Abstract

A powder spraying system includes a source of dry powder (4), a spray nozzle (25), and a supply conduit (16) connecting the source of dry powder with the spray nozzle. The spray nozzle includes a nozzle body (50) having a nozzle outlet (51), a first conduit (52) for dry powder, and a second conduit (53) for gas. The first conduit extends between a powder inlet (54) in communication with the supply conduit and a powder outlet (55). The second conduit extends between a gas inlet (56) and a gas outlet (57) located adjacent the powder outlet such that gas flowing through the second conduit and out the gas outlet creates a suction at the powder outlet to facilitate flow of dry powder through the first conduit and out the powder outlet and the nozzle outlet. The powder outlet and the gas outlet are oriented to facilitate mixing of the gas and the dry powder. The first conduit (52) is a straight conduit between the powder inlet (54) and the powder outlet (55).

Description

[0001] This disclosure relates to a powder spraying system and a powder spraying nozzle. Specifically, this disclosure relates to a powder spraying system and a powder spraying nozzle that can be used as part of an apparatus for coating a filter and in a method of coating a filter, the filter comprising a porous substrate having an inlet surface and an outlet surface, wherein the inlet surface is separated from the outlet surface by a porous structure. The filter may be, for example, a wall-flow filter for an emission control device for an internal combustion engine. Background Technology

[0002] There are concerns about particulate matter (PM) emissions (commonly known as soot) from internal combustion engines, particularly diesel and gasoline engines used in automotive applications. The main concern is related to potential health effects, especially the presence of very small particles in the nanometer range.

[0003] Diesel particulate filters (DPFs) and gasoline particulate filters (GPFs) are manufactured using a variety of materials, including sintered metals, ceramics, or metal fibers. The most common type in actual mass production is the wall-flow type, made of porous ceramic materials, which are manufactured as a monolithic array of numerous small channels extending along the length of the body. Alternating channels are blocked at one end, thus forcing exhaust gas through the porous ceramic channel walls, which prevent most particles from passing through, allowing only filtered gas to enter the environment. Commercially produced ceramic wall-flow filters include those made of cordierite, various forms of silicon carbide, and aluminum titanate. The actual shape and size of the filters used in vehicles, as well as characteristics such as channel wall thickness and porosity, depend on the application of interest. The average pore size in the filter channel walls of ceramic wall-flow filters through which gas passes is typically in the range of 5 μm to 50 μm, and usually around 20 μm. In stark contrast, most diesel particulate matter from high-speed diesel engines in modern passenger cars is very small, for example, 10 nm to 200 nm.

[0004] Some particulate matter (PM) may remain within the pore structure of the filter wall, and in some applications this can gradually accumulate until the pores are bridged by a network of PM, which then allows for the easy formation of a particulate cake on the inner wall of the filter channels. The particulate cake is an excellent filter medium, and its presence provides very high filtration efficiency. In some applications, soot is continuously burned on the filter during deposition, which prevents the accumulation of particulate cake on the filter.

[0005] For some filters, such as light-duty diesel particulate filters, it is necessary to periodically remove captured PM from the filter to prevent the buildup of excessive back pressure, which is detrimental to engine performance and can lead to poor fuel economy. Therefore, in diesel applications, the retained PM is removed from the filter by burning it in air during a process in which the amount of available air and excess fuel required to reach the high temperature needed to ignite the retained PM is carefully controlled. At the end of this process, commonly known as regeneration, removing the last remaining particles from the filter can result in a significant decrease in filtration efficiency and a burst of release of many small particles into the environment. Therefore, the filter may have low filtration efficiency during initial use and subsequently after each regeneration event and also during the latter part of each regeneration process.

[0006] Therefore, it is desirable to improve and / or maintain filtration efficiency at any time—for example, during the early lifespan of the filter when it is first used, and / or during and immediately after regeneration, and / or when the filter is loaded with soot.

[0007] Liu, X., Szente, J., Pakko, J., Lambert, C., et al., “Using Artificial Ash to Improve GPF Performance at Zero Mileage,” SAE Technical Paper 2019-01-0974, 2019, doi:10.4271 / 2019-01-0974 describes a process for loading a bare filter substrate with submicron alumina particles generated by an atomizer to create an “artificial ash” coating to reduce soot emissions during cold start conditions. The process consists of: generating aerosol particles by atomizing a liquid suspension with compressed air; drying the resulting ash-containing droplets by passing them through an oven; and capturing the dried ash particles by filtration to load them into a filter. This process utilizes… A high-capacity atomizer (model PLG-2100, PALAS, Germany) was used to provide a flow rate of 100 l / min for all sizes of bricks. Filter loading was monitored by recording the pressure drop across the filter and the PM concentrations before and after the filter using a DustTrak aerosol monitor (TSI, Minnesota, USA). While the process showed reduced soot emissions during cold start conditions, it is limited to substances that can be spray-dried, requires an atomizer, drying oven, and aerosol monitor, and the artificial ash loading conditions may be constrained by the conditions required to achieve complete drying of the liquid aerosol before it reaches the filter substrate.

[0008] WO2011 / 151711 describes a method for manufacturing a filter for filtering particulate matter from exhaust gases emitted from a lean-burning internal combustion engine. The filter includes a porous substrate having an inlet surface and an outlet surface, wherein the inlet surface is separated from the outlet surface by a porous structure containing pores of a first average pore size. The inlet surface includes a bridging network comprising interconnected refractory material particles on the pores of the porous structure. The method includes the step of contacting the inlet surface of the filter substrate with an aerosol comprising a refractory material in the form of dry powder. While the described process shows a reduction in PM emissions upon initial use and subsequently after each regeneration event, improvements to the process are desired, particularly improvements regarding the controllability of the parameters of the resulting filter.

[0009] US2019 / 0048771 describes an engine exhaust particulate filter comprising a porous substrate having inert nanoparticles at a concentration ranging from 0.01 g / L to 60 g / L relative to the filter volume of the substrate, a portion of the nanoparticles being arranged to form a regenerable porous structure configured to capture particulates from the exhaust gas stream. While the filter is intended to provide an improvement in zero-mileage efficiency of particulate filters, improvements in the process are desired, particularly in process controllability and flexibility.

[0010] The applicant has discovered (as fully described in its application GB1911704 filed on August 15, 2019, which is incorporated herein by reference in its entirety) that filters with improved filtration efficiency during the early lifespan of the filter upon initial use and / or during and immediately thereafter during regeneration and / or when the filter is loaded with soot can be obtained by a treatment method comprising the following steps:

[0011] a) The dry powder is contained in the storage container;

[0012] b) Positioning a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face separated by a porous structure;

[0013] c) A primary airflow through the porous structure of the filter is established by applying a pressure reduction to the outlet surface of the filter;

[0014] d) Transferring the dry powder from the reservoir to a spray device located upstream of the inlet face of the filter; and

[0015] e) Using the spraying device, spray the dry powder toward the inlet face of the filter, such that the dry powder is entrained in the primary airflow and passes through the inlet face of the filter to contact the porous structure.

[0016] In GB1911704, the applicant describes how the dry powder may optionally contain one or more of pyrolytic alumina, pyrolytic silica, pyrolytic titanium dioxide, silica aerogel, alumina aerogel, carbon aerogel, titanium dioxide aerogel, zirconium oxide aerogel, or cerium dioxide aerogel. Specifically, an example of a filter coated with pyrolytic alumina having a tap density of 0.05 g / L and a d50 of 5.97 microns is described.

[0017] Although this treatment method has been found to produce filters with improved filtration efficiency, further improvements are needed in the treatment of such filters, specifically, improvements in the durability of the treated filters.

[0018] Therefore, the applicant has discovered (as fully described in its application GB2002483 filed on February 21, 2020, which is incorporated herein by reference in its entirety) that the durability of treated filters can be improved by using dry powder in a spray process, the dry powder containing or consisting of a metal compound for forming a metal oxide through thermal decomposition.

[0019] In GB2002483, the applicant describes how using a metal compound that decomposes into a metal oxide as a dry powder can substantially improve the durability of the treated filter compared to treatment with metal oxides (including, for example, pyrolytic alumina), particularly the substantial improvement in the ability of the dry powder to remain adhered to the porous structure and resist detachment from the porous structure during subsequent operation of the filter.

[0020] Surprisingly, the applicant has discovered that improved adhesion of these dry powders can be achieved without the presence of any additional adhesives or adhesion promoters, or without the need for any high-temperature sintering of the filter. Specifically, it has been surprisingly found that good adhesion can be produced using such dry powders while maintaining high filtration efficiency and acceptable cold flow back pressure.

[0021] Although the treatment methods in GB1911704 and GB2002483 have been found to be effective in producing improved filters, improvements to these methods are still desired, specifically in the treatment of dry powder and spraying. Summary of the Invention

[0022] In a first aspect, this disclosure provides a powder spraying system comprising:

[0023] a) Dry powder source;

[0024] b) Spray nozzles; and

[0025] c) A supply conduit that connects the dry powder source to the spray nozzle;

[0026] The spray nozzle includes:

[0027] i) A nozzle body having a nozzle outlet;

[0028] ii) A first conduit for dry powder; and

[0029] iii) A second conduit for gas;

[0030] The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit;

[0031] The second conduit extends between the gas inlet and the gas outlet, which is located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0032] The powder outlet and the gas outlet are oriented to promote the mixing of the gas with the dry powder.

[0033] Advantageously, this powder atomization system provides improved handling and atomization of dry powder. For example, the use of the atomizing nozzle allows for more reliable and precise control of the atomization angle of the dry powder. Furthermore, providing suction at the powder outlet improves the dispersion and mixing of dry powder particles in the carrier gas of the atomized dry powder. For example, the atomizing nozzle can impart increased shear force and / or increased pressure drop to the dry powder as it passes through. This can advantageously deagglomerate the dry powder, for example, in cases where the dry powder particles tend to form sticky aggregates.

[0034] Additionally, providing suction at the powder outlet to facilitate the flow of dry powder through the first conduit and out of the powder outlet and nozzle outlet can advantageously help enable the dry powder to be gravity-fed into the spray nozzle. In the system of GB1911704, dry powder is fed from, for example, an upstream hopper to a spray nozzle by fluidizing and entraining the dry powder in a gas stream (e.g., compressed air) and conveying the gas-dry powder mixture along one or more conduits to the spray nozzle. However, this has been found to have some potential disadvantages in certain situations. For example, the energy of the gas stream conveying the dry powder to the spray nozzle tends to be high, resulting in the dry powder exiting the spray nozzle with relatively high energy. The dry powder leaving the spray nozzle may also not be mixed very uniformly with the gas stream, a problem that can be particularly prevalent when the gas:dry powder ratio of the mixture is high. Furthermore, when the air-dry powder mixture reaches the filter, the relatively high speed of the air-dry powder mixture can cause the dry powder to preferentially travel to the bottom portion of the filter channel, resulting in a less uniform distribution of the dry powder along the channel walls.

[0035] The powder atomization system of this disclosure mitigates or overcomes this problem by using suction at the powder outlet to facilitate the flow of dry powder through a first duct and out of the powder outlet and nozzle outlet. This means that a mixture of feed gas (e.g., compressed air) and dry powder is not required to deliver the dry powder to and through the atomization nozzle. Instead, dry powder from a dry powder source (or at least a portion of the dry powder source in communication with the supply duct) can be fed to the atomization nozzle through a supply duct without using a gas flow. For example, the dry powder does not need to be entrained in the airflow as it passes through the supply duct, but moves along the supply duct under the assistance of gravity assisted by the suction generated in the atomization nozzle. This allows for more precise control of the dry powder flow and allows for more uniform dispersion of the dry powder in the carrier gas. Additionally, dry powder can be atomized toward the filter inlet face with less energy.

[0036] It should be noted that when the dry powder source comprises multiple parts, such as multiple hoppers or storage locations with interconnected conduits, airflow can be used to entrain and move the dry powder as it moves from one part of the dry powder source to another. However, according to this disclosure, feeding from the terminal portion of the dry powder source (e.g., a hopper or storage location immediately upstream of the supply conduit) is carried out by gravity assisted by suction generated in the spray nozzle, and no airflow in the supply conduit is used to entrain the dry powder.

[0037] In a second aspect, this disclosure provides a powder spray nozzle, comprising:

[0038] i) A nozzle body having a nozzle outlet;

[0039] ii) A first conduit for dry powder; and

[0040] iii) A second conduit for gas;

[0041] The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit;

[0042] The second conduit extends between the gas inlet and the gas outlet, which is located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0043] The first conduit is a straight conduit between the powder inlet and the powder outlet.

[0044] Advantageously, using a straight conduit between the powder inlet and the powder outlet can help improve powder flow and significantly reduce the chance of blockage. For example, this arrangement can reduce or preferably eliminate the occurrence of stagnant areas where dry powder may accumulate. This can be particularly advantageous in systems where spray nozzles are used as described in the first aspect above, where dry powder is fed to the powder inlet of the first conduit without the use of a gas flow, for example by gravity assisted by suction generated in the spray nozzle. In such systems, reducing or eliminating any surfaces that may act as accumulation points for powder buildup can be particularly important.

[0045] Furthermore, a straight first conduit advantageously increases the velocity of the dry powder through it, which reduces the tendency for the dry powder to settle and accumulate on the inner surface of the spray nozzle. Additionally, using a straight first conduit as part of a powder spray nozzle that generates suction at the powder outlet may be particularly advantageous for dry powders that do not readily flow through the conduit, as suction and fluidization within the nozzle facilitate the flow of the dry powder in such cases.

[0046] When used in a treatment method for a filter, a powder spray system and powder spray nozzles may be found for specific applications. The filter may be, for example, a wall-flow filter used in an emission control device for an internal combustion engine. Examples of such filters include, but are not limited to, diesel particulate filters (DPF) and gasoline particulate filters (GPF). The treatment method may include the following steps:

[0047] a) The dry powder is contained in the dry powder source (e.g., in a storage container);

[0048] b) Positioning a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face separated by a porous structure;

[0049] c) A primary airflow through the porous structure of the filter is established by applying a pressure reduction to the outlet surface of the filter;

[0050] d) Transferring the dry powder from the dry powder source to the spray nozzle located upstream of the inlet face of the filter via the supply conduit; and

[0051] e) Use the spray nozzle to spray the dry powder toward the inlet face of the filter, so that the dry powder is entrained in the primary airflow and passes through the inlet face of the filter to contact the porous structure.

[0052] In a third aspect, this disclosure provides a method for treating a filter that filters particulate matter from exhaust gas, the method comprising the following steps:

[0053] a) The dry powder is contained in the storage container;

[0054] b) Positioning a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face separated by a porous structure;

[0055] c) A primary airflow through the porous structure of the filter is established by applying a pressure reduction to the outlet surface of the filter;

[0056] d) Transferring the dry powder from the reservoir to a spray device located upstream of the inlet face of the filter via a supply conduit; and

[0057] e) Using the spraying device, spray the dry powder toward the inlet face of the filter, such that the dry powder is entrained in the primary airflow and passes through the inlet face of the filter to contact the porous structure;

[0058] The dry powder is transferred to the spraying device via the supply conduit by gravity and / or by the suction force generated within the spraying device.

[0059] Advantageously, the dry powder can be transferred to the spraying device via the supply conduit solely by gravity and / or by suction generated within the spraying device. Optionally, the reservoir may include a hopper for direct feeding into the supply conduit, and the dry powder may be dispensed into the hopper. Dispensing may be by weight of the dry powder.

[0060] The spraying device may include a spray nozzle (e.g., a powder spray nozzle of the second aspect) which may be supplied with a pressurized gas flow along a conduit separate from the supply conduit, the pressurized gas flow being used in the spray nozzle to generate the suction force.

[0061] The powder spraying system of the first aspect may also include one or more of the following features:

[0062] The dry powder source may be aligned with the first conduit of the nozzle body, optionally wherein the dry powder source may coincide with the longitudinal axis of the first conduit. The dry powder source may include one or more hoppers.

[0063] The supply conduit between the dry powder source and the spray nozzle can be straight.

[0064] The inner diameter of the supply conduit between the dry powder source and the spray nozzle can be from 1 mm to 20 mm, optionally from 5 mm to 10 mm.

[0065] The spray nozzle can be oriented such that the nozzle outlet faces downwards and the dry powder source is located directly above the spray nozzle.

[0066] When this powder spraying system is used in a filter processing method, the filter can be vertically oriented within the retainer, with the inlet face of the filter at the top. The spray nozzle can be vertically positioned above the inlet face; and optionally, the spray direction of the spray nozzle can be coaxial with the longitudinal axis of the filter; and optionally, the spray direction and the longitudinal axis coincide. Advantageously, this arrangement provides a simplified process and better dry powder dispersion, and advantageously leaves no residual dry powder in the conduit feeding the powder spray nozzle.

[0067] The powder spraying system may also include a dispensing device for dispensing dry powder from a dry powder source. The dispensing device can dispense the dry powder directly into a supply conduit or into a hopper that feeds directly into the supply conduit. The dispensing device can dispense by weight, volume, particle number, or time, or by a combination of these factors. The dispensing device can be a loss-in-weight feeder. Advantageously, using a dispensing device, optionally a weight-feed dispensing device, provides more controllable and accurate dispensing of the dry powder.

[0068] Any of the above aspects may also include one or more of the following features:

[0069] The powder outlet may be located within the nozzle body upstream of the nozzle outlet, such that the initial mixing of the gas and the dry powder occurs within the nozzle body upstream of the nozzle outlet. The gas outlet may be located within the nozzle body upstream of the nozzle outlet.

[0070] Alternatively, the powder outlet may be located at or near the nozzle outlet of the nozzle body, such that the initial mixing of the gas with the dry powder occurs outside the nozzle body. In this case, the gas outlet may be located at or near the nozzle outlet of the nozzle body.

[0071] The gas outlet may include an annular outlet surrounding the powder outlet.

[0072] The powder outlet can be centrally located on the longitudinal axis of the nozzle body.

[0073] In some examples, the powder outlet may include a single powder orifice. In other examples, the powder outlet may include multiple powder orifices, each associated with the gas outlet of the second conduit. At least one of the multiple powder orifices may be oriented along the longitudinal axis of the nozzle body. At least one of the multiple powder orifices may be oriented at a divergence angle relative to the longitudinal axis of the nozzle body. The orifice diameter of the powder orifice, or each powder orifice, may be from 0.5 mm to 5.0 mm, optionally from 1.0 mm to 2.5 mm, optionally from 1.0 mm to 2.0 mm. These orifice sizes result in good dispersion of the dry powder.

[0074] The gas outlet may include an annular orifice surrounding the associated powder orifice or each associated powder orifice. The width of the annular orifice may be from 0.2 mm to 2.0 mm, optionally from 0.2 mm to 1.0 mm, optionally from 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0075] The nozzle outlet may be located in the first end face of the nozzle body, and the powder inlet may be located in the opposite second end face of the nozzle body.

[0076] The first conduit can be a straight conduit between the powder inlet and the powder outlet.

[0077] The first conduit may be parallel to the longitudinal axis of the nozzle body, and optionally coincide with the longitudinal axis of the nozzle body.

[0078] The first conduit may include a bore whose inner diameter decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0079] The first conduit may include a bore whose inner diameter smoothly decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0080] The first conduit may include a bore whose inner diameter is specifically reduced from a first diameter at the powder inlet to a second diameter at or near the powder outlet via one or more tapering sections.

[0081] The nozzle body may include one or more secondary gas outlets spaced apart from the nozzle outlet and oriented to guide one or more secondary gas flows to impinge on the gas and dry powder flow leaving the nozzle outlet. The impingement is outside the nozzle body and at a distance from the nozzle outlet.

[0082] The one or more secondary gas outlets may be oriented to guide the one or more secondary gas flows such that they are at an angle of incidence of 30° to 90°, optionally 45° to 75°, optionally 60° with respect to the gas and dry powder flow exiting the nozzle outlet.

[0083] The one or more secondary gas outlets may include 2, 4, 6, 8 or more secondary gas outlets; and optionally, the one or more secondary gas outlets may form 1, 2, 3, 4 or more pairs of secondary gas outlets, wherein each pair of secondary gas outlets may include two secondary gas outlets located on opposite sides of the nozzle outlet.

[0084] The orifice diameter of each of these secondary gas outlets can be from 0.5 mm to 2.5 mm, optionally from 1.0 mm to 2.5 mm.

[0085] The one or more secondary gas outlets may be disposed in one or more legs protruding from the surface of the nozzle body including the nozzle outlet, such that the one or more secondary gas outlets are axially located downstream of the nozzle outlet; and optionally, the one or more secondary gas outlets may be located 2 mm to 20 mm, optionally 8 mm to 15 mm, axially downstream of the nozzle outlet.

[0086] The nozzle body may include a third conduit, which is separate from the second conduit, for supplying gas to the secondary gas outlet.

[0087] The nozzle body may include a tubular element that defines at least the powder outlet of the first conduit and a top cover element, wherein the clearance between the tubular element and the top cover element defines the gas outlet.

[0088] The clearance between the tubular element and the top cover element can be 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, or optionally 0.6 mm.

[0089] The spray nozzle may further include a cleaning nozzle located within the first conduit, connected to a gas supply source, and having an outlet oriented toward the powder outlet. The outlet of the cleaning nozzle may be located 2 mm to 50 mm, optionally 4 mm to 25 mm, from the powder outlet. The outlet may include a single orifice or multiple orifices. The outlet may include 1 to 10, optionally 1 to 3 orifices. The orifice or the diameter of each orifice may be 0.5 mm to 1.5 mm, optionally 0.5 mm.

[0090] Advantageously, the cleaning nozzle can be used to reduce the chance of blockage at the powder outlet. For example, a compressed airflow can be ejected from the outlet at the inner surface of the powder outlet to break up and remove any accumulation of dry powder in the area of ​​the powder outlet.

[0091] The cleaning nozzle can be configured to generate suction within the first conduit to facilitate the flow of dry powder through the first conduit. The cleaning nozzle can also be configured to fluidize the dry powder within the first conduit.

[0092] The cleaning nozzle may include an elongated tubular element located within the first conduit to define an annular flow space for the dry powder between the outer wall of the cleaning nozzle and the inner wall of the first conduit.

[0093] The dry powder source may include a first dry powder source and a second dry powder source, and wherein the first conduit may include a first powder inlet communicating with the first dry powder source and a second powder inlet communicating with the second dry powder source; wherein the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of the first dry powder and the second dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0094] The first conduit may include a first flow path along at least a portion of its length for the first dry powder and a second flow path along at least a portion of its length for the second dry powder, the first flow path and the second flow path being separate from each other; and optionally wherein the first flow path and the second flow path may include concentrically arranged flow paths.

[0095] The powder spraying system or powder spraying nozzle described above can be incorporated as part of an apparatus for treating a filter that filters particulate matter from exhaust gas. The apparatus may further include: a filter retainer for holding the filter, wherein the nozzle outlet of the powder spraying nozzle is oriented to spray the dry powder toward the inlet face of the filter. The apparatus may further include: a vacuum generator in communication with the outlet face of the filter for generating a primary airflow through the filter, wherein the powder spraying nozzle is located upstream of the inlet face of the filter and is oriented to spray the dry powder into the primary airflow upstream of the inlet face of the filter. The apparatus may further include: a flow conduit upstream of the inlet face for guiding the primary airflow toward the inlet face of the filter; and an adapter located between the flow conduit and the filter; the adapter being configured to adapt the shape and / or size of the flow conduit to the shape and / or size of the inlet face of the filter.

[0096] The adapter may include a tubular body having an upper seal at its upper end and a lower seal at its lower end; wherein the upper end of the adapter may have a first inner diameter adapted to the inner diameter of the lower end of the flow conduit, and the lower end of the adapter may have a second inner diameter adapted to the diameter of the inlet face of the filter; and optionally wherein the first inner diameter of the adapter may be greater than or less than the second inner diameter.

[0097] The dry powder atomized through the powder spray nozzle and in the powder spraying system described above may comprise or consist of one or more refractory powders, optionally comprising one or more pyrolytic refractory powders and / or one or more aerogels. The one or more pyrolytic refractory powders may be produced by a pyrochemical process, such as flame pyrolysis. The one or more pyrolytic refractory powders may include one or more of pyrolytic alumina, pyrolytic silica, pyrolytic titanium dioxide, other pyrolytic metal oxides, and pyrolytic mixed oxides. The one or more aerogels may include one or more of silica aerogel, alumina aerogel, carbon aerogel, titanium dioxide aerogel, zirconium oxide aerogel, cerium dioxide aerogel, metal oxide aerogel, and mixed oxide aerogel.

[0098] In these examples, the tap density of the dry powder can be less than 0.10 g / cm³. 3 Optionally less than 0.08 g / cm³ 3 Optionally less than 0.07 g / cm³ 3 Optionally less than 0.06 g / cm³ 3 Optionally less than 0.05 g / cm³ 3 The d50 (by volume) of the dry powder may be less than 25 micrometers, optionally less than 20 micrometers, and optionally less than 10 micrometers.

[0099] The dry powder atomized through the powder spray nozzle and in the powder spray system may optionally contain or consist of a metal compound for forming a metal oxide by thermal decomposition. The dry powder may consist of a single metal compound, or may consist of a mixture or blend, or a continuous dose of two or more metal compounds. The metal compound, or each metal compound, may contain one or more metal cations. In the presence of multiple metal cations, these metal compounds may use the same or different metals. The metal compound may contain or consist of: metal hydroxides, metal phosphates, metal carbonates, metal sulfates, metal perchlorates, metal iodides, metal oxalates, metal acetates, metal chlorates, or mixtures thereof. The metal of the metal compound may contain or consist of: one or more of magnesium, calcium, strontium, barium, aluminum, zirconium, manganese, lithium, iron, cobalt, nickel, copper, or gallium. The dry powder may also contain metal oxides or mixed metal oxides. Optionally, the dry powder contains 90% by weight or more of a metal compound for forming a metal oxide by thermal decomposition, and 10% by weight or less of a metal oxide or mixed metal oxide. Optionally, the dry powder contains 95% by weight or more of a metal compound for forming a metal oxide by thermal decomposition, and 5% by weight or less of a metal oxide or mixed metal oxide. Optionally, the dry powder contains 99% by weight or more of a metal compound for forming a metal oxide by thermal decomposition, and 1% by weight or less of a metal oxide or mixed metal oxide. The metal in the metal oxide or mixed metal oxide may contain or consist of one or more of the following: aluminum, magnesium, calcium, strontium, barium, aluminum, zirconium, manganese, lithium, iron, cobalt, nickel, copper, or gallium. Optionally, the dry powder contains or consists of the following: metal hydroxides, metal phosphates, metal carbonates, or mixtures thereof. The metal hydroxide may be selected from the group consisting of: magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide. Metal phosphates can be selected from the group consisting of: magnesium phosphate, calcium phosphate, strontium phosphate, and barium phosphate. Metal carbonates can be selected from the group consisting of: magnesium carbonate, calcium carbonate, strontium carbonate, and barium carbonate.

[0100] In these examples, the tap density of the dry powder can be from 1 g / cm³ to 3 g / cm³. 3 Choose between 1.5 g / cm³ to 2.5 g / cm³. 3 Approximately 2g / cm³ (optional) 3 The d50 (by volume) of the dry powder can be less than 10 micrometers, optionally less than 5 micrometers, or optionally about 2 micrometers.

[0101] Dry powder can consist of a single powder type or a mixture of powder types.

[0102] When a powder spraying system is used in a filter treatment method, the transfer of dry powder from the dry powder source to the spray nozzle can be controlled independently of establishing and controlling the primary airflow; and optionally, the spraying of dry powder toward the filter inlet face can be controlled independently of establishing and controlling the primary airflow. Advantageously, by controlling the transfer and / or spraying of dry powder from the dry powder source to the spray nozzle independently of controlling the establishment and control of the primary airflow, a more controllable process can be achieved. For example, the gas flow rate and / or volumetric flow rate of the primary airflow can be changed without changing the rate and / or velocity of the dry powder transfer from the spray nozzle and / or the spraying velocity. This contrasts with methods that also use the primary airflow through the filter to fluidize the dry powder.

[0103] Optionally, a primary airflow is established before the dry powder is transferred to the spray nozzle and sprayed toward the inlet face. Advantageously, this allows for a more uniform airflow to be established through the porous structure before the spraying of the dry powder begins. Furthermore, this enables better dispersion of the dry powder as it enters and passes through the porous structure.

[0104] Optionally, the airflow through the second duct of the spray nozzle is separated from the primary airflow and can be controlled independently of the primary airflow. Advantageously, by controlling the primary airflow independently of controlling the airflow through the spray nozzle, a more controllable process can be achieved. For example, the volumetric flow rate of the airflow through the spray nozzle can be selected to optimize the spray characteristics of the dry powder at one or more outlets of the spray nozzle, and the volumetric flow rate of the primary airflow can be selected separately to optimize the deposition of dry powder in the porous structure of the filter.

[0105] The airflow through the second duct of the spray nozzle may include a compressed gas flow, or optionally an air flow.

[0106] When the powder spraying system is used in a filter treatment method, the powder spraying system may further include a flow conduit for guiding the dry powder exiting the nozzle outlet toward the filter inlet face.

[0107] Flow ducts provide an unobstructed flow path between the spray nozzle and the inlet face of the filter.

[0108] Alternatively, the flow duct may include a flow conditioner inserted between the inlet face of the spray nozzle and the filter to facilitate the dispersion of dry powder within the airflow. The flow conditioner may include one or more of a static mixer, a screen, a sieve, a baffle, and an orifice plate.

[0109] The filter inlet face can be located at a distance greater than 10 cm, optionally greater than 20 cm, from the nozzle outlet of the spray nozzle. Particular benefits are obtained when the filter inlet face is located at a distance greater than 75 cm, optionally greater than 100 cm, from the nozzle outlet of the spray nozzle. Advantageously, this spacing increases the percentage area of ​​the filter's inlet face for receiving dry powder, thereby resulting in improved uniformity of dry powder application to the filter. Additionally or alternatively, the spray nozzle outlet nozzle can be located at a distance from the filter inlet face, which is up to four times the diameter of the filter inlet face.

[0110] In this specification, the term "filter" refers to a porous substrate having a porous structure suitable for filtering particulate matter from exhaust gases. The porous substrate can be formed, for example, from sintered metal, ceramic, or metal fibers. Filters can be of the wall-flow type made of porous materials (e.g., ceramic), manufactured as a monolithic array of numerous small channels extending along the length of the substrate. For example, filters can be formed from cordierite, various forms of silicon carbide, or aluminum titanate.

[0111] The filter can be a "bare" filter or alternatively a filter with incorporated catalytic capabilities (such as oxidation, NOx capture, or selective catalytic reduction activity). The porous substrate can include a composition of porous structures coated with the filter (referred to as a support coating). The support coating can be a catalytic support coating. The catalytic support coating can include a catalyst selected from the group consisting of hydrocarbon traps, three-way catalysts (TWCs), NOx absorbers, oxidation catalysts, selective catalytic reduction (SCR) catalysts, lean NOx catalysts, and any combination of two or more of these. The catalyst (e.g., TWCs, NOx absorbers, oxidation catalysts, hydrocarbon traps, and lean NOx catalysts) can contain one or more platinum group metals, particularly those selected from the group consisting of platinum, palladium, and rhodium.

[0112] Therefore, the coated filter can be, for example, a catalytic soot filter (CSF), a selective catalytic reduction filter (SCRF), a lean NOx trap filter (LNTF), a gasoline particulate filter (GPF), an ammonia leak catalyst filter (ASCF), or a combination of two or more of them (e.g., a filter including a selective catalytic reduction (SCR) catalyst and an ammonia leak catalyst (ASC).

[0113] The shape and dimensions of a filter (e.g., characteristics such as channel wall thickness and porosity) can vary depending on the intended application of the filter. A filter can be configured for use with an internal combustion engine to filter exhaust gases emitted by that engine. The internal combustion engine can be a gasoline spark-ignition engine. However, when configured for use with an internal combustion engine in the form of a diesel or gasoline engine, the filter has a specific application.

[0114] In this specification, the term "dry powder" refers to a particulate composition that is not suspended or dissolved in a liquid. This does not necessarily mean the complete absence of all water molecules. Dry powder is optionally free-flowing.

[0115] In this specification, the term "tap density" refers to the tap density of a powder measured by 1250 taps according to Method 1 of Section 2.9.35 of the European Pharmacopoeia 7.0.

[0116] In this specification, the term "g / l" (grams per liter) refers to the mass of the dry powder divided by the volume of the filter.

[0117] In this specification, when referring to the amount of dry powder, the terms "load" and "mass load" refer to the mass of powder added to the filter, and can be measured by weighing the filter before and after the powder is applied to it.

[0118] In this specification, the term "d50 (by volume)" refers to Malvern Panalytical Ltd. of Malvern, UK, which uses Aero s dispersion units. d50 (by volume) measurement results from 3000. Dispersion conditions: air pressure = 2 barg, feed rate = 65%, hopper gap = 1.2 mm. (Based on Malvern) The instructions in the 3000 user manual provide guidance on setting the refractive index and absorption parameters.

[0119] In this specification, the term "vacuum generator" refers to a device or combination of devices used to generate a reduced pressure. Non-limiting examples of suitable devices include vacuum generators operating according to the Venturi principle, vacuum pumps such as rotary vane and liquid ring vacuum pumps, and regenerative blowers.

[0120] In this specification, the term "pressure sensor" refers to a device or combination of devices used to measure absolute pressure and / or relative pressure. Non-limiting examples of suitable devices include pressure transducers that can be diaphragm pressure transducers. For example, the P30 pressure transmitter, available from WIKA Alexander Wiegand SE&Co.KG in Klingenberg, Germany, can be used.

[0121] In this specification, the term "controller" refers to a function that may include hardware and / or software. A controller may include a control unit or a computer program that runs on dedicated or shared computing resources. A controller may include a single unit or may consist of multiple subunits operatively connected. A controller may reside on a single processing resource or may be distributed across spatially separated processing resources. A controller may include a microcontroller, one or more processors (such as one or more microprocessors), memory, configurable logic, firmware, etc.

[0122] In this specification, ranges and quantities may be expressed as “about” a specific value or range. “About” also includes exact quantities. For example, “about 2 micrometers” means “about 2 micrometers” as well as “2 micrometers”. Generally, the term “about” includes quantities expected to be within experimental error. The term “about” can include values ​​within 5% less to 5% greater than the provided value. For example, “about 2 micrometers” means “between 1.9 micrometers and 2.1 micrometers”.

[0123] In this specification, the expression "composed of" means that the dry powder is essentially composed of only the specified ingredients, excluding unavoidable impurities that are commonly encountered and will be recognized by those skilled in the art. Attached Figure Description

[0124] Aspects and embodiments of this disclosure will now be described by way of example only with reference to the accompanying drawings, in which:

[0125] Figure 1 This is a schematic diagram of a device used to process particulate matter filtered from exhaust gas;

[0126] Figure 2 This is a flowchart illustrating a method for manufacturing a filter, which incorporates the use of Figure 1 The method of processing filters in equipment;

[0127] Figure 3 It shows the use Figure 1 The flowchart shows a method for a device to treat particulate matter from exhaust gas using a filter.

[0128] Figure 4 Another schematic diagram of an apparatus for treating a filter for filtering particulate matter from exhaust gas, which is incorporated into a powder spraying system according to the present disclosure, is shown.

[0129] Figure 5 It is used for Figure 1 and Figure 4 A schematic diagram of the powder conveying equipment;

[0130] Figure 6 and Figure 7Two types of powder spray nozzles according to this disclosure are schematically shown;

[0131] Figure 8 and Figure 9 A cross-sectional view of a first embodiment of a powder spray nozzle according to the present disclosure is shown;

[0132] Figure 10 It shows Figure 7 and Figure 8 A magnified view of a portion of the powder spray nozzle;

[0133] Figure 11 and Figure 12 A cross-sectional view of a second embodiment of a powder spray nozzle according to the present disclosure is shown;

[0134] Figure 13 and Figure 14 A cross-sectional view of a third embodiment of a powder spray nozzle according to the present disclosure is shown;

[0135] Figure 15 It shows Figure 13 and Figure 14 A magnified view of a portion of the powder spray nozzle;

[0136] Figure 16 A cross-sectional view of a fourth embodiment of a powder spray nozzle according to the present disclosure is shown;

[0137] Figure 17 It is used for Figure 1 and Figure 4 A cross-sectional view of the adapter portion of the device;

[0138] Figure 18 and Figure 19 The flow regulator is shown;

[0139] Figure 20 It shows the incorporation Figure 1 and Figure 4 The flow regulator in the flow conduit of the device; and

[0140] Figure 21 Another arrangement of the device according to this disclosure is shown. Detailed Implementation

[0141] Readers in the art will recognize that, unless the present context otherwise teaches, one or more features of one aspect or embodiment of this disclosure may be combined with one or more features of any other aspect or embodiment of this disclosure.

[0142] Now we will first refer to Figure 1The description of the powder spraying system and powder spraying nozzle according to this disclosure illustrates a schematic diagram of an apparatus 1 for treating a filter 2 that filters particulate matter from exhaust gas. The filter 2 is of the type comprising a porous substrate having an inlet surface and an outlet surface separated by a porous structure.

[0143] The device 1 includes a reservoir 3 for containing dry powder 4. A filter retainer 5 is provided for holding the filter 2. A vacuum generator 6 is provided for establishing a primary airflow through the porous structure of the filter 2 during use by applying reduced pressure to the outlet face of the filter 2. A conveying device 8 is provided for conveying the dry powder 4 from the reservoir 3 to a spraying device 7. A spraying device 7 is provided for receiving the dry powder 4 from the conveying device 8 and spraying the dry powder 4 toward the inlet face of the filter 2. A controller 9 is provided, which is configured to control the operation of the device 1.

[0144] The reservoir 3 can receive dry powder 4 from the dry powder inlet 11. The reservoir 3 serves as a source of dry powder. The dry powder inlet 11 can be an output of the upstream stacked supply of dry powder. For example, the dry powder inlet 11 can be a conduit connected upstream to another reservoir of dry powder 4. The dry powder inlet 11 can represent manual, semi-automatic, or automatic refilling of the reservoir 3 through a cover or opening of the reservoir 3.

[0145] The storage container 3 may include one or more hoppers. The storage container 3 may include one hopper. Figure 1 In the illustrated example, the reservoir 3 includes a first hopper 12 and a second hopper 13. The second hopper 13 may be downstream of the first hopper 12 to receive the dry powder 4 output from the first hopper 12. One or more hoppers may be housed in a separate housing. Alternatively, one or more hoppers may be housed in a single housing. One or more hoppers may comprise one or more chambers of a single container.

[0146] The storage container 3 may include a dispensing device 15. The dispensing device 15 can dispense dry powder 4 by one or more of the following: weight, volume, number of particles, and time. The dispensing device 15 may be located at or near the outlet of the storage container 3. The dispensing device 15 may be located at or near the outlet of one or more hoppers of the storage container 3. The dispensing device may be located at or near the outlet of the first hopper 12, or at or near the outlet of the second hopper 13, or, in the case of more than two hoppers, the terminal hopper.

[0147] The dispensing device 15 can feed dry powder 4 from the storage tank 3 by weight.

[0148] The feeding device 15 may be a loss-in-weight feeder. The feeding device 15 may be a volumetric feeder including a helical or threaded arrangement. Non-limiting examples of suitable feeding devices include those available from Coperion GmbH in Stuttgart, Germany. K-Tron Type K2-ML-T35 Gravimetric twin-screw feeder and available from Sandy All-Fill International Ltd, UK. Series S1 Micro-Fill and Series 10 weight or volume spiral fillers.

[0149] The conveying device 8 transports the dry powder 4 from the storage container 3 to the spraying device 7. The conveying device 8 can feed the dry powder 4 at least partially toward the spraying device 7 by weight or by volume.

[0150] The conveying device 8 may include one or more components. The conveying device 8 may include one or more conduits, such as channels, pipes, hoses, etc.

[0151] In cases where the reservoir 3 includes more than one hopper, the conveying device 8 can convey the dry powder 4 between the hoppers. The conveying device 8 can feed the dry powder 4 between the hoppers in a gravimetric or volumetric manner. The conveying device 8 may include a first conduit 14 extending between the first hopper 12 and the second hopper 13. The first conduit 14 can extend from the first housing to the second housing. Alternatively, the first conduit 14 can extend from the first chamber to the second chamber of a single container. The dry powder 4 can be fed along the first conduit 14 in a gravimetric manner.

[0152] The conveying device 8 may include a supply conduit 16 extending from the second hopper 13 to the spraying device 7. The supply conduit 16 may be used to supply dry powder to the spraying device 7. It should be understood that, in addition to those devices explicitly described herein, other suitable devices may also be used to supply dry powder 4 to the upstream end of the supply conduit 16.

[0153] The dispensing device 15 can dispense dry powder 4 directly from the second hopper 13 into the supply conduit 16. In an alternative embodiment, the dispensing device 15 can dispense dry powder 4 from the first hopper 12 into the second hopper 13, and the second hopper 13 can feed directly into the supply conduit 16 by gravity.

[0154] A spraying device 7 is provided for receiving dry powder 4 from a conveying device 8 and spraying the dry powder 4 toward the inlet face of the filter 2. The spraying device 7 may include a spray nozzle 25 and a secondary airflow generator for generating a secondary airflow, which can be used in conjunction with the spray nozzle 25 to spray the dry powder 4 toward the inlet face of the filter 2.

[0155] The secondary airflow generator may include a compressed gas generator. Figure 1 In the illustrated example, the secondary airflow generator includes a compressed air generator, which may include a compressor 22. The compressor 22 receives air from an air inlet 21 and supplies compressed air to the spray nozzle 25 via a feed line 23. A return line 24 may be provided. Valves and controls required for operation may be provided, as will be known to those skilled in the art.

[0156] An interconnection may be provided between the conveying device 8 (e.g., supply conduit 16) and the spraying device 7, at which the dry powder 4 is transferred from the conveying device 8 to the spraying device 7. The interconnection may be located at or within the spray nozzle 25. The design and function of the spray nozzle 25 will be further described below.

[0157] The filter retainer 5 can be used to hold the filter 2 in a stationary position during processing. The filter retainer 5 can grip the upper and / or lower ends of the filter 2. The filter retainer 5 may include an expandable upper sealing bladder 31 (also referred to as an upper expandable collar) and / or an expandable lower sealing bladder 30 (also referred to as a lower expandable collar), which support the respective upper and lower ends of the filter 2. The expandable upper sealing bladder 31 and the expandable lower sealing bladder 30 may contact and / or engage with the outer surface of the filter 2. They may each form a liquid-impermeable or air-impermeable seal around the filter 2. The expandable upper sealing bladder 31 and the expandable lower sealing bladder 30 may be supported by one or more housings (e.g., by the inner walls of one or more housings).

[0158] Device 1 can be configured such that filter 2 is positioned vertically within filter holder 5 with the filter inlet face at the top. Spray nozzle 25 can be vertically positioned above the inlet face. The spray direction of spray nozzle 25 can be coaxial with the longitudinal axis of filter 2. The spray direction and the longitudinal axis of filter 2 can coincide.

[0159] The device 1 may further include a flow conduit 10 located between the spray device 7 and the inlet face of the filter 2. The flow conduit 10 may be used to constrain and guide the primary airflow toward the inlet face of the filter 2. The flow conduit 10 may be used to align the primary airflow such that when the primary airflow contacts the inlet face of the filter 2, the flow direction of the primary airflow is perpendicular to the inlet face.

[0160] The flow conduit 10 may include a pipe. The flow conduit 10 may include a cross-sectional shape that matches the cross-sectional shape of the inlet face of the filter 2. The flow conduit 10 may include a size that matches the size of the inlet face of the filter 2.

[0161] The spraying device 7 can extend into the flow conduit 10. For example, the spray nozzle 25 can be located in the upper region of the flow conduit 10. The spray nozzle 25 can coincide with the longitudinal axis of the filter 2.

[0162] The inlet face of filter 2 may be located at a distance greater than 10 cm, optionally greater than 20 cm, from the spray device 7. Particular benefits are obtained when the inlet face of filter 2 is located at a distance greater than 75 cm, optionally greater than 100 cm, from the nozzle outlet of spray nozzle 25. Additionally or alternatively, the spray device (e.g., spray nozzle 25) may be located at a distance from the inlet face of filter 2, which is up to four times the diameter of the inlet face of filter 2.

[0163] A vacuum generator 6 is provided to establish a primary airflow through the porous structure of the filter 2 during use by applying reduced pressure to the outlet face of the filter 2. The vacuum generator 6 may include a vacuum cone 40 that defines a funnel engaging the outlet face of the filter 2. An expandable lower sealing bladder 30 may form a seal between the outlet face of the filter 2 and the vacuum cone 40. The vacuum generator 6 may include a vacuum pump 42 connected to the flow cone via a conduit 43. The vacuum pump 42 can be controlled to control the volumetric flow rate of the primary airflow.

[0164] The vacuum generator 6 may be equipped with a volumetric flow sensor. The volumetric flow sensor may be an orifice plate 44 combined with a pressure sensor 45 positioned along the conduit 43. The vacuum generator 6 may include a bypass conduit 46 extending to the inlet 47.

[0165] Device 1 may further include a pressure sensor 41 for monitoring the back pressure of filter 2. A single pressure sensor 41 may be used. The single pressure sensor 41 may be located in vacuum generator 6, optionally in the filter holder or other housing of vacuum generator, such as vacuum cone 40.

[0166] Controller 9 controls the operation of at least vacuum generator 6 and spray device 7. Figure 1 For clarity, the operational connections between controller 9 and the rest of device 1 have been omitted. However, those skilled in the art will understand that any suitable connection may be provided. Such connections may be wired or wireless.

[0167] The controller 9 can be configured to control the transfer of dry powder 4 from the reservoir 3 to the spraying device 7 via the conveying device 8, independently of controlling the primary airflow generated by the vacuum generator 6. For example, the controller 9 can control the operation of the dispensing device 15.

[0168] The controller 9 can be configured to control the spraying of dry powder 4 toward the inlet face of the filter 2 independently of controlling the primary airflow. As used in this specification, the term "independent" refers to the ability of the controller 9 to control each variable of the spraying of dry powder 4 and the primary airflow independently of the state of other variables. For example, the controller 9 can establish the primary airflow even when dry powder 4 is not sprayed simultaneously. For example, the controller 9 can increase or decrease the spraying rate of dry powder 4 without changing the volumetric flow rate of the primary airflow. For example, the controller 9 can increase or decrease the volumetric flow rate of the primary airflow without changing the spraying rate of dry powder 4. For example, the controller 9 can control the operation of the spraying device 7 independently of controlling the operation of the vacuum pump 42.

[0169] The controller 9 can be configured to operate the vacuum generator 6 to establish a primary airflow before the dry powder 4 is transferred to the spray device 7 and sprayed toward the inlet face of the filter 2.

[0170] The controller 9 can be configured to control the secondary airflow generator, such as the compressor 22, independently of the vacuum generator 6. The controller 9 can be configured to operate the vacuum generator 6 to maintain the primary airflow as a continuous airflow through the porous structure, and to operate the secondary airflow generator (e.g., the compressor 22) only for a portion of the time period of the primary airflow.

[0171] The controller 9 can be configured to control the vacuum generator 6 independently of the control conveying device 8 and / or the spraying device 7 to control the speed or mass rate of the dry powder 4 sprayed toward the inlet face of the filter 2, thereby controlling the level of pressure reduction applied to the outlet face of the filter 2.

[0172] The controller 9 can be configured to stop the spraying of dry powder 4 toward the inlet face of the filter 2 when a predetermined back pressure of the filter 2, detected for example by the pressure sensor 41, is reached. The predetermined back pressure can be an absolute back pressure, or alternatively, a relative back pressure. The controller 9 can also be configured to stop the spraying of dry powder 4 toward the inlet face of the filter 2 when a predetermined total spraying time is reached.

[0173] Device 1 can be used to treat a filter with dry powder 4, which comprises or consists of one or more refractory powders, optionally including one or more pyrolytic refractory powders and / or one or more aerogels. Additionally or alternatively, device 1 can be used to treat a filter with dry powder 4, which comprises or consists of a metal compound for forming a metal oxide through thermal decomposition. In an example, the metal compound may comprise or consist of metal hydroxides, metal phosphates, metal carbonates, metal sulfates, metal perchlorates, metal iodides, metal oxalates, metal acetates, metal chlorates, or mixtures thereof.

[0174] Now refer to Figure 2The following figure illustrates an example of a method for processing a filter according to this disclosure, showing a flowchart of a method for manufacturing a filter 2 using device 1. The method will be described with reference only to a filter 2 having a catalytic coating.

[0175] In step S21, a catalytic slurry is prepared by methods known in the art.

[0176] In step S22, a support coating is prepared from the catalytic slurry using methods known in the art. The support coating may be, for example, a hydrocarbon trap, a three-way catalyst (TWC), a NOx absorbent, an oxidation catalyst, a selective catalytic reduction (SCR) catalyst, a NOx-lean catalyst, and any combination of two or more thereof.

[0177] In step S23, the carrier coating is dosed and applied to the bare filter 2 using methods known in the art. For example, the carrier coating may be applied to a first side (e.g., the top) of the filter 2, and the opposite second side (e.g., the bottom) of the filter 2 may be subjected to at least a partial vacuum to allow the carrier coating to move through the porous structure of the filter 2. The filter 2 may be coated with a single dose, wherein the carrier coating may be applied to the filter 2 in a single step, wherein the filter 2 is held in a single orientation. Alternatively, the filter 2 may be coated with two doses. For example, in the first dose, the filter 2 may be in a first orientation, wherein the first side is on top and the second side is on the bottom. The coating is applied to the first side and coats a portion of the length of the filter 2. The filter 2 may then be inverted such that the second side is on top. The coating may then be applied to the second side to coat the portion of the filter 2 not coated with the first dose. Advantageously, the dual-dose process allows different coatings to be applied to each end of the filter 2.

[0178] In step S24, filter 2 can be dried.

[0179] In step S25, the filter 2 can be calcined using methods known in the art.

[0180] In optional step S26, the back pressure of filter 2 before treatment can be measured.

[0181] In optional step S27, filter 2 can be placed in inventory awaiting processing. Subsequently, in step S28, filter 2 can be removed from inventory and processed. Alternatively, filter 2 can be processed immediately, i.e., proceeding directly to step S29.

[0182] In step S29, filter 2 can be processed, as will be referred to below. Figure 3 Further detailed description.

[0183] In step S30, after processing, filter 2 can be calcined.

[0184] If appropriate, the filter can be calcined at a selected temperature to produce the thermal decomposition of dry powder 4.

[0185] The calcination temperature can be selected to be at least 150°C, optionally at least 250°C, and optionally at least 500°C. In some embodiments, it is preferred that the calcination temperature is not greater than 550°C. However, in other embodiments, the calcination temperature can be selected to be greater than 550°C. The calcination temperature can be selected to be up to 900°C, optionally up to 1150°C. In one example, the calcination temperature can be selected to be between 300°C and 500°C. In another example, the calcination temperature can be selected to be about 520°C. In another example, the calcination temperature can be selected to be about 580°C. In yet another example, the calcination temperature can be selected to be about 900°C.

[0186] Calcination can be carried out for a period of 30 to 90 minutes, optionally 30 to 60 minutes. In one example, the period is about 35 minutes. In another example, the period is about 60 minutes. During calcination, the residence time is 1 to 15 minutes, optionally 5 to 10 minutes.

[0187] In optional step S31, the back pressure of the treated filter 2 can be measured.

[0188] In step S32, the finished filter 2 can be prepared for delivery to the customer.

[0189] Figure 3 It shows Figure 2 The flowchart for step S29.

[0190] In step S29-1, the filter can be loaded into the filter holder 5. The filter 2 can be held in a stationary position during processing. The filter 2 can be gripped by the filter holder 5 at its upper and / or lower ends. The expandable upper sealing bladder 31 and the expandable lower sealing bladder 30 can expand to contact and / or engage with the outer surface of the filter 2. The filter 2 can be held in a vertical orientation with the filter inlet face at the top. The operation of the filter holder 5, such as the expansion of the expandable upper sealing bladder 31 and the expandable lower sealing bladder 30, can be controlled by the controller 9.

[0191] In step S29-2, the vacuum generator 6 can be activated by the controller 9 to establish a primary airflow through the filter 2. Optionally, the primary airflow is established before the dry powder 4 is transferred to the spray nozzle 25 of the spray device 7 and sprayed toward the inlet face of the filter 2. The level of pressure reduction generated by the vacuum generator 6 can be controlled by the controller 9 independently of the speed or mass rate at which the dry powder 4 is transferred from the reservoir 3 to the spray device 7. The volumetric flow rate of the primary airflow can be 10 m³ / s. 3 / h to 5000m 3 / h, optional 400m 3 / h to 2000m 3 / h, optional 600m 3 / h to 1000m 3 / h.

[0192] In step S29-3, the back pressure of filter 2 can be measured before the establishment of the primary airflow but before the establishment of the secondary airflow. The back pressure can be measured using pressure sensor 41. The back pressure measurement in step S29-3 can supplement or replace the back pressure measurement in step S26. Alternatively, the back pressure measurement in step S26 can replace the back pressure measurement in step S29-3. The back pressure measurement in step S26 and / or the back pressure measurement in step S29-3 can be used by controller 9 as a measure of the initial back pressure of filter 2 before processing.

[0193] In step S29-4, the dry powder 4 is sprayed onto the inlet face of the filter 2 by the spraying device 7. During the spraying of the dry powder 4, the dry powder 4 can be supplied to the spraying device 7 by the conveying device 8.

[0194] The spray of dry powder 4 toward the inlet face of filter 2 can optionally be controlled by controller 9 independently of establishing and controlling the primary airflow.

[0195] During steps S29-4, a secondary airflow, separated from the primary airflow and provided, for example, by compressor 22, can be used to transfer dry powder 4 from reservoir 3 to spray device 7. Optionally, the secondary airflow can be controlled by controller 9 independently of the primary airflow. For example, controller 9 can control the operation of compressor 22 and / or valves and / or spray nozzles 25 of spray device 7 independently of the operation of control vacuum pump 42. Dry powder 4 can be sprayed toward the inlet face of filter 2 using the secondary airflow. The secondary airflow may include a compressed gas flow, optionally an air flow.

[0196] During step S29-4, the primary airflow may optionally be maintained as a continuous flow. During step S29-4, the secondary airflow may be applied as a single burst or multiple intermittent bursts.

[0197] In step S29-5, the back pressure of filter 2 can be monitored. This back pressure can be monitored using pressure sensor 41. Controller 9 can be configured to stop the spraying of dry powder 4 toward the inlet face of filter 2 when a predetermined back pressure is reached. If the predetermined back pressure has not yet been reached, controller 9 is configured to return to step S29-4 and continue spraying dry powder 4. This feedback can be continuous and does not necessarily involve any pause in the spraying of dry powder 4; that is, controller 9 can continuously monitor the back pressure of filter 2 while the spraying of dry powder 4 is in progress.

[0198] The predetermined back pressure can be an absolute back pressure. The absolute back pressure can be 600m. 3 The flow rate is 20 mbar to 180 mbar per hour.

[0199] Alternatively, the predetermined back pressure can be a relative back pressure. For example, a back pressure relative to the first back pressure of filter 2 before treatment, measured in steps S26 and / or S29-3, can be used. The back pressure can be measured as a percentage of the first back pressure. When the spraying of dry powder 4 is stopped, the predetermined back pressure can be 105% to 200% of the first back pressure, optionally 125% to 150%.

[0200] Alternatively, the spraying of dry powder 4 toward the inlet face of filter 2 may be stopped when the predetermined total spraying time is reached. The predetermined total spraying time may be from 1 second to 60 seconds, optionally from 1 second to 20 seconds, optionally about 10 seconds.

[0201] The controller 9 can be configured to stop the spraying of dry powder 4 toward the inlet face of the filter 2 when the predetermined total spraying time, the predetermined back pressure of the filter, or the target mass of dry powder has been sprayed toward the inlet face of the filter.

[0202] In step S29-6, the spraying of dry powder 4 is stopped. This can be achieved, for example, by the controller 9 stopping the transfer of dry powder via the conveyor 8 and / or by stopping the secondary airflow of the spraying device 7. Optionally, in step S29-6, after the spraying of dry powder 4 is stopped, the primary airflow is maintained through the porous structure of the filter 2 for a certain period of time. The controller 9 can be configured to operate the vacuum generator 6 for a certain period of time after the spraying of dry powder 4 is stopped.

[0203] Optionally, in steps S29-6, the amount of dry powder 4 delivered toward the inlet face of the filter 2 can be measured. The controller 9 is configured to determine the amount of dry powder 4 delivered based on the signal output of the dispensing device 15, for example, based on the output from the loss-in-weight feeder.

[0204] The method can be configured to deliver a maximum load of 10 g / l to 40 g / l, optionally 15 g / l to 30 g / l, optionally about 20 g / l of dry powder 4 of the filter; or to deliver a maximum load of <10 g / l, optionally <5 g / l, optionally <2 g / l of dry powder 4 of the filter.

[0205] In steps S29-7, the primary airflow through filter 2 is stopped. This can be achieved by the controller 9 stopping the vacuum generator 6, i.e., stopping the vacuum pump 42. Alternatively, this can be achieved by the controller operating a valve on the vacuum generator 6 to redirect the suction through the bypass duct 46 to suction air through the inlet 47. This avoids the need to stop the vacuum pump 42 between consecutive processes of filter 2, which could result in a faster cycle time.

[0206] In steps S29-8, the filter 2 is unloaded from the filter holder 5 by, for example, contracting the expandable upper sealing bladder 31 and the expandable lower sealing bladder 30. The filter 2 can then be removed and the process proceeds to step S30 as described above.

[0207] Figure 4 A schematic diagram of another embodiment of device 1 is shown. The same reference numerals are used for the same parts of both devices. In the following description, only the differences between the two devices will be described, and specifically, those differences relating to the spatial arrangement of hoppers 12, 13 and spray nozzles 25. For all other details, the reader may refer to the references above. Figure 1 The description of the equipment and methods given also applies to this embodiment.

[0208] Figure 4 The device 1 includes a spraying device 7, which includes spray nozzles 25 oriented toward a filter 2, which is mounted in a filter holder. A vacuum generator 6 establishes a primary airflow through the device 1.

[0209] The first hopper 12 can receive dry powder 4 from the dry powder inlet 11. The first hopper 12 serves as a source (or part of a source) of the dry powder 4. The dry powder inlet 11 can be an output of an upstream stockpiled supply of dry powder. For example, the dry powder inlet 11 can be a conduit connected upstream to another hopper or reservoir of dry powder 4. The dry powder inlet 11 can represent manual, semi-automatic, or automatic refilling of the first hopper 12.

[0210] The source of dry powder 4 may include one or more hoppers. The source of dry powder 4 may include one hopper. Figure 4In the illustrated example, the dry powder source includes a first hopper 12 and a second hopper 13, the first hopper serving as a stacking hopper and the second hopper serving as a feed hopper. The second hopper 13 is downstream of the first hopper 12 and receives the dry powder 4 output from the first hopper 12. The hoppers may be housed in separate housings. Alternatively, the hoppers may be housed in a single housing. The hoppers may include one or more chambers of a single container. One or both of hoppers 12 and 13 may be provided with one or more vents 17 to achieve pressure equalization with atmospheric pressure. One or both of hoppers 12 and 13 may be provided with a level sensor, which may be used as part of a control system for automatic or semi-automatic refilling of the hoppers. One or both of hoppers 12 and 13 may be provided with a vibrator to promote the flow of the dry powder 4 within the hopper toward the hopper outlet.

[0211] In cases where the source of dry powder comprises multiple parts (e.g., multiple hoppers 12, 13 or storage locations), these parts can be interconnected via conduits. Devices for transferring the dry powder 4 between the parts may be provided, such as devices for moving the dry powder from a first location to a second location, for example, from a storage location to a first hopper 12 via a dry powder inlet 11.

[0212] like Figure 5 As schematically shown, the dry powder inlet 11 can be fed by an upstream powder delivery system. In this example, as part of the upstream powder delivery system, a storage unit 130 for dry powder 4 and a powder delivery unit 132 for delivering dry powder 4 into a first hopper 12 (e.g., into a stacking hopper) are provided.

[0213] Storage unit 130 and powder delivery unit 132 can be interconnected via transfer conduit 131. Transfer conduit 131 can be a tube or conveyor belt or the like for conveying dry powder 4, for example, mechanically or pneumatically (by positive or negative pressure differential).

[0214] Storage unit 130 may be, for example, an enclosed chamber to reduce the dispersion of dry powder 4 outside the powder delivery system. For example, storage unit 130 may be a glove box containing one or more containers of dry powder 4.

[0215] Used along Figure 5 The device for conveying dry powder 4 through the transfer conduit 131 may be, for example, a vacuum transfer device, such as those available from Piab USA in Pittsburgh, USA; a diaphragm pump, such as those available from Axflow of Slough in the UK; or a powder feeding system, such as those available from Gema Switzerland GmbH in St. Gallen, Switzerland.

[0216] The storage container 3 may include a dispensing device 15. The dispensing device 15 can dispense dry powder 4 by one or more of the following: weight, volume, number of particles, and time. The dispensing device 15 may be located at or near the outlet of the storage container 3. The dispensing device 15 may be located at or near the outlet of one or more hoppers of the storage container 3. The dispensing device may be located at or near the outlet of the first hopper 12, or at or near the outlet of the second hopper 13, or, in the case of more than two hoppers, the terminal hopper. Figure 4 In the example shown, the dispensing device 15 is located between the first hopper 12 and the second hopper 13. The dispensing device 15 can feed dry powder 4 from the first hopper 12 by weight. The supply conduit 16 extends from the second hopper 13 to the spraying device 7. The supply conduit 16 is used to supply dry powder to the spraying device 7. Dry powder 4 can be dispensed from the first hopper 12 to the second hopper 13 using the dispensing device 15. The second hopper 13 can be fed directly into the supply conduit 16 by gravity.

[0217] However, the airflow can be used to entrain and move the dry powder 4 as it moves from the storage unit 130 to the first hopper 12. The feed from the terminal part of the dry powder source (e.g., the second hopper 13) to the supply conduit 16 is carried out by gravity, assisted by the suction force generated in the spray nozzle 25 (as described below), and the airflow in the supply conduit 16 is not used to entrain the dry powder 4.

[0218] As described above, the feeding device 15 can be a weight and / or volume feeder including a helical or threaded arrangement. Non-limiting examples of suitable feeding devices include those available from Coperion GmbH in Stuttgart, Germany. K-Tron Type K2-ML-T35 Gravimetric twin-screw feeder and available from Sandy All-Fill International Ltd, UK. Series S1 Micro-Fill and Series 10 weight or volume spiral fillers.

[0219] A spraying device 7 is provided for receiving dry powder 4 from a supply conduit 16 and spraying the dry powder 4 toward the inlet face of the filter 2. A controller is provided, which is configured to control the operation of the device 1. The spraying device 7 includes a spray nozzle 25 and a secondary airflow generator for generating a secondary airflow, which can be used in conjunction with the spray nozzle 25 to spray the dry powder 4 toward the inlet face of the filter 2. Figure 4 The feed line 23 for supplying secondary airflow to the spray nozzle 25 is shown schematically. The design and function of the spray nozzle 25 will be described further below.

[0220] The secondary airflow generator may include a compressed gas generator. The secondary airflow generator may include a compressed air generator, which may include a compressor. The compressor may receive air from an air inlet and supply compressed air to the spray nozzle 25 via a feed line 23. A return line may be provided. Valves and controls required for operation may be provided, as will be known to those skilled in the art.

[0221] The source of dry powder 4, together with the spray nozzle 25 and the supply conduit 16, can constitute part of the powder spraying system.

[0222] The source of the dry powder 4 can be aligned with the spray nozzle 25 (specifically, with the first conduit of the nozzle body of the spray nozzle 25, as will be explained below). The source of the dry powder 4 can be aligned with the longitudinal axis of the first conduit. For example, at least the second hopper 13 of the reservoir 3 can be aligned with the spray nozzle 25. The first hopper 12 can also be aligned with the spray nozzle 25, although this is optional.

[0223] Preferably, the spray nozzle 25 is oriented such that the nozzle outlet of the spray nozzle 25 faces downward, for example vertically downward, and at least the second hopper 13 is located directly above the spray nozzle 25.

[0224] The supply conduit 16 between the second hopper 13 and the spray nozzle 25 can be straight. The inner diameter of the supply conduit 16 can be from 1 mm to 20 mm, optionally from 5 mm to 10 mm.

[0225] Advantageously, using a straight supply conduit 16 between the second hopper 13 and the spray nozzle 25 can help improve powder flow and significantly reduce the chance of supply conduit blockage. Furthermore, the straight supply conduit 16 can facilitate a system in which dry powder 4 is fed into the spray nozzle 25, for example by gravity assisted by the suction force generated in the spray nozzle 25, without the use of a gas flow. In such systems, reducing or eliminating any surfaces that might act as accumulation points for powder buildup may be particularly important.

[0226] The filter retainer 5 can be designed and used as described above to keep the filter 2 in a stationary position during processing.

[0227] The flow duct 10 can be designed and used as described above to constrain and guide the primary airflow toward the inlet face of the filter 2.

[0228] As described above, the spray nozzle 25 may be vertically positioned above the inlet face of the filter 2. The spray direction of the spray nozzle 25 may be coaxial with the longitudinal axis of the filter 2. The spray direction and the longitudinal axis of the filter 2 may coincide. The spray nozzle 25 may extend into the flow duct 10. For example, the spray nozzle 25 may be located in the upper region of the flow duct 10. The spray nozzle 25 may coincide with the longitudinal axis of the filter 2. The inlet face of the filter 2 may be located at a distance greater than 10 cm, optionally greater than 20 cm, from the nozzle outlet of the spray nozzle 25. Particular benefits are obtained when the inlet face of the filter 2 is located at a distance greater than 75 cm, optionally greater than 100 cm, from the nozzle outlet of the spray nozzle 25. For example, such a distance allows the dry powder 4 to achieve sufficient residence time in the flow duct 10 to better achieve good mixing of the dry powder 4 in the airflow passing through the flow duct 10. Additionally or alternatively, the spray nozzle 25 may be located at a distance from the inlet face of the filter 2, which is up to 4 times the diameter of the inlet face 2 of the filter.

[0229] The vacuum generator 6 can be designed and used as described above to establish a primary airflow through the porous structure of the filter 2 by applying pressure reduction to the outlet face of the filter 2 during use.

[0230] The controller can be designed and used as described above to control the operation of device 1.

[0231] Figure 4 Device 1 can be used to treat filters with dry powder 4, as referenced above, for example. Figure 2 and Figure 3 As described in the associated description. Specifically, dry powder 4 can be any of the types mentioned above.

[0232] Now, a more detailed description will be given, for example, what can be used as... Figure 1 and / or Figure 4 The spray nozzle 25 is a part of the device 1.

[0233] Figure 6 and Figure 7Two types of spray nozzles 25 are schematically shown. In both cases, the spray nozzle 25 includes: a nozzle body 50 having a nozzle outlet 51; a first conduit 52 for dry powder 4; and a second conduit 53 for gas. The first conduit 52 extends between a powder inlet 54 and a powder outlet 55, which can be connected to communicate with a supply conduit 16. The second conduit 53 extends between a gas inlet 56 and a gas outlet 57. The gas outlet 57 is located near the powder outlet 55, such that the gas flowing through the second conduit 53 and out of the gas outlet 57 causes a pressure drop, which creates a suction force at the powder outlet 55 to promote the flow of dry powder 4 through the first conduit 52 and out of the powder outlet 55 and the nozzle outlet 51. The powder outlet 55 and the gas outlet 57 are oriented to promote mixing of the gas with the dry powder 4.

[0234] exist Figure 6 In the spray nozzle 25, the powder outlet 55 is located at or near the nozzle outlet 51 of the nozzle body 50, such that the initial mixing of the gas and the dry powder 4 occurs outside the nozzle body 50. The gas outlet 57 is located at or near the nozzle outlet 51 of the nozzle body 50, for example, adjacent to the nozzle outlet.

[0235] exist Figure 7 In the spray nozzle 25, the powder outlet 55 is located within the nozzle body 50 upstream of the nozzle outlet 51, such that the initial mixing of the gas and dry powder 4 occurs within the nozzle body 50 upstream of the nozzle outlet 51. The gas outlet 57 is located within the nozzle body 50 upstream of the nozzle outlet 51.

[0236] Gas outlet 57 may include an annular outlet surrounding powder outlet 55. Powder outlet 55 may be centrally located on the longitudinal axis XX of nozzle body 50.

[0237] Figures 8 to 10 A first embodiment of the powder spray nozzle 25 according to this disclosure is shown. This embodiment is... Figure 6 The type shown schematically is that the initial mixing of gas and dry powder 4 occurs outside the nozzle body 50.

[0238] The nozzle body 50 may include multiple parts assembled together. For example, the nozzle body 50 may include a first body element 62, a second body element 63, and a top cover element 65.

[0239] The second body element 63 may be connected to the first body element 62, and these elements may be sealed together using an O-ring seal 64. Alternatively, the first body element 62 and the second body element 63 may be formed as a single integral component. The top cover element 65 may be connected to the second body element 63, and these elements may be sealed together using a gasket 66.

[0240] A first tubular element 60 may be provided, which defines at least a portion of the first conduit 52 and the powder outlet 55. The first tubular element 60 may be connected to a second body element 63 of the nozzle body 50, or may form an integral part of the second body element.

[0241] The first tubular element 60 may have a proximal portion 70, which is cylindrical and has a constant inner diameter. It may also have a distal portion 71, which tapers in the direction of the powder outlet 55 with a decreasing inner diameter. It may also have a terminal portion 72, which itself defines the orifice of the powder outlet 55, and is cylindrical and has a constant inner diameter.

[0242] A second tubular element 61 may be provided, which defines another portion of the first conduit 52 and the powder inlet 54. The second tubular element 61 may be connected to the first body element 62 of the nozzle body 50, or may form an integral part of the first body element.

[0243] The second tubular element 61 may have a proximal portion 73 that defines a powder inlet 54 and is cylindrical with a constant inner diameter. It may also have a distal portion 74 that tapers in the direction of the first tubular element 60 with a decreasing inner diameter. It may also optionally have a terminal portion 75 connected to the proximal portion 70 of the first tubular element 60, which is cylindrical and has a constant inner diameter.

[0244] The first conduit 52 is preferably a straight conduit between the powder inlet 54 and the powder outlet 55. For example, portions 73-75 of the second tubular element 61 and portions 70-72 of the first tubular element 60 are preferably aligned with the longitudinal axis XX of the nozzle body 50, and more preferably coincide with the longitudinal axis.

[0245] The nozzle outlet 51 is located in the first end face 80 of the nozzle body 50, and the powder inlet 54 is located in the opposite second end face 81 of the nozzle body 50.

[0246] The first conduit 52 preferably includes a bore whose inner diameter is reduced, for example, specifically via one or more tapering sections (i.e., distal portions 71 and 74) from a first diameter at the powder inlet 54 to a second diameter at or near the powder outlet 55.

[0247] The bore of the first conduit 52 is preferably smooth and without any abrupt, inwardly pointing shoulders or cracks that could constitute obstacles or collection points for the dry powder 4 during use.

[0248] A top cap element 65 may be coupled to the distal end of the first tubular element 60. The top cap element 65 may include an orifice forming the nozzle outlet 51. When coupled, the distal end of the first tubular element 60 may be disposed in or near the orifice in the top cap element 65, such that an annular clearance between the first tubular element 60 and the top cap element 65 defines a gas outlet 57, as... Figure 10 The annular clearance between the first tubular element 60 and the top cover element 65 can be 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm, as shown most clearly in the diagram.

[0249] The second body element 63 may partially define the second conduit 53. The gas inlet 56 may be oriented laterally, for example, on the side of the nozzle body 50. The second conduit 53 may include a first portion 58 extending laterally from the gas inlet 56 and a second portion 59 extending longitudinally from the first portion 58 to the gas outlet 57.

[0250] The first tubular element 60 may be received within the second portion 59 of the second conduit 53, such that the second conduit 53 in this region comprises an annular conduit extending between the inner surface of the second body element 63 and the outer surface of the first body element 62.

[0251] In this embodiment, the powder outlet 55 is a single powder orifice. The single powder orifice may be located in the distal end of the first tubular element 60 and oriented XX along the longitudinal axis of the nozzle body 50. The orifice diameter may be from 0.5 mm to 5.0 mm, optionally from 1.0 mm to 2.5 mm, optionally from 1.0 mm to 2.0 mm.

[0252] In use, the powder inlet 54 can be connected to the supply conduit 16 of device 1. The gas inlet 56 can be connected to the feed line 23. The airflow from the feed line 23 enters the spray nozzle 25 through the gas inlet 56 and is passed along the first section 58 and the second section 59, and then exits through the gas outlet 57 and the nozzle outlet 51. The airflow passing near the powder outlet 55 causes a pressure drop, thereby generating a suction force at the powder outlet 55. This suction force assists the dry powder 4 to flow downward through the first conduit 52. The dry powder 4 from the supply conduit 16 is fed into the powder inlet 54 by gravity, and gravity drives the dry powder downward along the first conduit 52. The suction force at the powder outlet 55 assists the movement of the dry powder 4, for example, by helping to draw the dry powder 4 toward the powder outlet 55 and / or by fluidizing the dry powder 4 in the first conduit 52 near the powder outlet 55 to prevent blockage of the powder outlet 55.

[0253] Feed line 23 can supply gas at a flow rate greater than 60 liters per minute (lpm), optionally greater than 100 lpm, optionally greater than 150 lpm, and optionally greater than 200 lpm. In some examples, the feed line supplies gas at a pressure of 1 barg at a flow rate greater than 60 lpm; in some examples, at a pressure of 2 barg at a flow rate greater than 100 lpm; in some examples, at a pressure of 3 barg at a flow rate greater than 140 lpm; in some examples, at a pressure of 4 barg at a flow rate greater than 175 lpm; in some examples, at a pressure of 5 barg at a flow rate greater than 215 lpm; and in some examples, at a pressure of 6 barg at a flow rate greater than 250 lpm.

[0254] The reduced diameter of the first conduit 52 in the direction of the powder outlet 55 can have the effect of applying shear force to the particles of the dry powder 4, which can result in a reduction in the particle size of at least some of the particles. For example, the d50 (by volume) of the dry powder 4 can be reduced during transport through the first conduit 52.

[0255] Powder outlet 55 and gas outlet 57 are oriented to facilitate mixing of gas with dry powder 4, for example, in the region outside nozzle body 50 and downstream of nozzle outlet 51. Mixing of gas with dry powder 4 can assist in the dispersion and / or deagglomeration of dry powder 4.

[0256] The number, size, shape, and relative positioning of the powder outlet 55 and the gas outlet 57 can be used to control the shape and size of the dry powder plume emitted from the spray nozzle 25. For example, Figures 7 to 9 The embodiment of the spray nozzle 25 is particularly suitable for generating a conical dry powder plume having a circular shape in cross-section. The dry powder plume can be centered on the longitudinal axis XX of the nozzle body 50, which can coincide with the longitudinal axis of the filter 2.

[0257] The flow rate of the gas leaving the gas outlet 57 can also be changed to control the shape and size of the dry powder plume emitted from the spray nozzle 25.

[0258] Figures 11 to 12 A second embodiment of the powder spray nozzle 25 according to this disclosure is shown. (With) Figures 8 to 10 The same parts of the spray nozzle 25 shown in the first embodiment are designated with the same reference numerals. In the following description, only the differences between the two devices will be described. For all other details, the reader may refer to the references above. Figures 8 to 10 The given description of the spray nozzle also applies to this embodiment.

[0259] In this embodiment, the powder outlet 55 includes a plurality of powder orifices located in the distal end of the first tubular element 60. The orifice diameter of each powder orifice can be from 0.5 mm to 5.0 mm, optionally from 1.0 mm to 2.5 mm, optionally from 1.0 mm to 2.0 mm. At least one of the powder orifices may be oriented along the longitudinal axis XX of the nozzle body 50. The remaining powder orifices may be oriented at a divergence angle relative to the longitudinal axis XX.

[0260] As previously described, the gap between the first tubular element 60 and the top cap element 65 defines a gas outlet 57. Each powder orifice is associated with a gas outlet 57 of the second conduit 53. Specifically, each powder orifice may be surrounded by an annular clearance from the top cap element 65. The annular clearance between the first tubular element 60 and the top cap element 65 surrounding each powder orifice may be 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0261] Figures 11 to 12 The embodiment of the spray nozzle 25 is particularly suitable for generating a multi-conical dry powder plume, which has a cross-sectional shape composed of overlapping circles. The dry powder plume can be centered on the longitudinal axis XX of the nozzle body 50, which can coincide with the longitudinal axis of the filter 2. The action of the airflow passing near the powder orifice of the powder outlet 55 causes a pressure drop, thereby generating a suction force at the powder outlet 55, as described above. This suction force assists the dry powder 4 to flow downward through the first conduit 52.

[0262] Figures 13 to 15 A third embodiment of the powder spray nozzle 25 according to this disclosure is shown. The same reference numerals are used for the same parts of the spray nozzle 25 shown in the first and second embodiments. In the following description, only the differences between the devices will be described. For all other details, the reader may refer to the above references. Figures 8 to 12 The given description of the spray nozzle also applies to this embodiment.

[0263] In this embodiment, the powder outlet 55 is a single powder orifice, in a manner similar to... Figures 8 to 10 The first embodiment is the same. A single powder orifice may be provided in the distal end of the first tubular element 60 and oriented XX along the longitudinal axis of the nozzle body 50. The orifice diameter of the powder orifice may be 0.5 mm to 5.0 mm, optionally 1.0 mm to 2.5 mm, optionally 1.0 mm to 2.0 mm.

[0264] Gas outlet 57 is the same as in the first embodiment, except that it is provided with a plurality of optional additional gas vents 90, such as Figure 13 As shown.

[0265] The difference in this embodiment lies primarily in that the first conduit 52 includes a bore whose inner diameter smoothly decreases from a first diameter at the powder inlet 54 to a second diameter at or near the powder outlet 55. For example, the bore may include a smoothly tapered section 85 and a cylindrical section 86. The bore of the first conduit 52 is preferably smooth and without any abrupt, inwardly pointing shoulders or cracks that could potentially constitute obstructions or collection points for the dry powder 4 during use.

[0266] The difference in this implementation is that one or more secondary gas outlets 100 are provided, which are spaced apart from the nozzle outlet 51 and are oriented to guide one or more secondary gas flows 105 to impinge on the gas and dry powder flow leaving the nozzle outlet 51. The impingement occurs outside the nozzle body 50 and at a certain distance from the nozzle outlet 51.

[0267] One or more secondary gas outlets 100 are oriented to guide one or more secondary gas flows 105 such that their angle of incidence α with the gas exiting the nozzle outlet 51 and the dry powder flow 103 is 30° to 90°, optionally 45° to 75°, optionally 60°, as... Figure 15 As shown.

[0268] Two, four, six, eight or more secondary gas outlets 100 may be provided. They may be configured as one, two, three, four or more pairs of secondary gas outlets 100. Each pair of secondary gas outlets 100 may include two secondary gas outlets located on opposite sides of the nozzle outlet 51.

[0269] The orifice diameter of each secondary gas outlet in the secondary gas outlet 100 can be from 0.5 mm to 2.5 mm, optionally from 1.0 mm to 2.5 mm.

[0270] The secondary gas outlet 100 may be disposed in one or more legs 101 protruding from the surface of the nozzle body 50 including the nozzle outlet 51, such that the one or more secondary gas outlets 100 are axially located downstream of the nozzle outlet 51. For example, the secondary gas outlet 100 may be located 2 mm to 20 mm, optionally 8 mm to 15 mm, axially downstream of the nozzle outlet.

[0271] Each outrigger 101 may include one, two or more secondary gas outlets 100.

[0272] The nozzle body 50 may be equipped with two support legs 101. For example... Figures 13 to 15 As shown, the two legs 101 can be positioned opposite each other across the nozzle outlet 51. This arrangement is particularly suitable for generating oval, elliptical, or fan-shaped dry powder plumes.

[0273] Optionally, the nozzle body 50 may be provided with four legs 101. The four legs may be equidistant from each other at 90° intervals around the nozzle outlet 51.

[0274] The nozzle body 50 may include a third conduit 102, which is separate from the second conduit 53, for supplying gas to the secondary gas outlet 100. The third conduit 102 may have an inlet 104 that can be disposed in the top cover element 65.

[0275] In use, as in the aforementioned embodiments, the airflow passing near the powder outlet 55 causes a pressure reduction, thereby generating a suction force at the powder outlet 55, as described above. This suction force assists the dry powder 4 to flow downward through the first conduit 52. Furthermore, as in the aforementioned embodiments, the powder outlet 55 and the gas outlet 57 are oriented to promote mixing of the gas and the dry powder 4, for example, in the region outside the nozzle body 50 and downstream of the nozzle outlet 51. The mixing of the gas and the dry powder 4 can assist in the dispersion and / or deagglomeration of the dry powder 4. Additionally, the impact of the secondary airflow 105 on the dry powder 4 can result in additional shaping of the plume of the dry powder 4 and / or additional dispersion and / or deagglomeration of the dry powder.

[0276] Figure 16 A fourth embodiment of the powder spray nozzle 25 according to this disclosure is shown. The same reference numerals are used for the same parts as those shown in the embodiments described above. In the following description, only differences between devices will be described. For all other details, the reader may refer to the above references. Figures 8 to 12 The given description of the spray nozzle also applies to this embodiment.

[0277] In this embodiment, the spray nozzle 25 further includes a cleaning nozzle 110 located within the first conduit 52, the cleaning nozzle 110 including an inlet 111 connectable to a gas supply source and an outlet 112 oriented toward the powder outlet 55.

[0278] The outlet 112 of the cleaning nozzle can be located 55.4 mm to 25 mm from the powder outlet. The orifice diameter of the outlet 112 of the cleaning nozzle can be 0.5 mm to 1.5 mm, optionally 0.5 mm.

[0279] In use, a compressed airflow can be ejected from outlet 112 at the inner surface of powder outlet 55 to break up and remove any accumulation of dry powder 4 in the area of ​​powder outlet 55. The cleaning function of cleaning nozzle 110 can be actuated between treatments of each filter 2, or during treatment of the filter 2, i.e., while the flow of dry powder 4 is passing through the first conduit 52. The airflow exiting from cleaning nozzle 110 can be in a single burst or multiple bursts.

[0280] The cleaning nozzle 110 can be configured to generate a suction force within the first conduit 52 to assist the dry powder 4 in flowing through the first conduit 52. The cleaning nozzle 110 can also be configured to fluidize the dry powder 4 within the first conduit 52, particularly near the powder outlet 55.

[0281] The cleaning nozzle 110 may include an elongated tubular element 113 located within a first conduit 52 to define an annular flow space 114 for the dry powder 4 between the outer wall of the cleaning nozzle 110 and the inner wall of the first conduit 52.

[0282] The cleaning nozzle 110 may be incorporated into any of the embodiments of the spray nozzle 25 described above.

[0283] In any of the above embodiments, the source of dry powder 4 may include a first source of dry powder and a second source of dry powder. The first conduit 52 may include a first powder inlet communicating with the source of the first dry powder and a second powder inlet communicating with the source of the second dry powder. Gas flowing through the second conduit 53 and exiting the gas outlet 57 may generate a suction force at the powder outlet 55 to facilitate the flow of the first and second dry powders through the first conduit 52 and out of the powder outlet 55 and the nozzle outlet 51. The first conduit 52 may include a first flow path for the first dry powder and a second flow path for the second dry powder along at least a portion of its length, the first and second flow paths being separate from each other. The first and second flow paths may be concentrically arranged flow paths.

[0284] In any of the above embodiments, device 1 may further include: an adapter 120 located between flow conduit 10 and filter 2, such as, for example... Figure 17 As shown. Adapter 120 can be used to adapt the shape and / or size of the primary airflow to the shape and size of the inlet face of filter 2. For example, the diameter of flow duct 10 may be different from the diameter of the inlet face. The diameter of flow duct 10 may be larger or smaller than the diameter of the inlet face. The shapes may also be different; for example, flow duct 10 may have a circular cross-sectional shape and the inlet face of filter 2 may have an elliptical shape.

[0285] The adapter 120 may include a tubular body having an upper seal 121 at its upper end for providing a fluid-tight connection to the flow conduit 10, and a lower seal 122 at its lower end for providing a fluid-tight seal around the inlet face of the filter 2. The lower seal 122 may supplement or replace the upper sealing sac 31. A third seal 123 may be provided for a fluid-tight seal around the outlet face of the filter 2. The third seal 123 may supplement or replace the lower sealing sac 30.

[0286] The upper seal 121, the lower seal 122 and the third seal 123 may be inflatable bladder seals or elastic, flexible non-inflatable seals.

[0287] The upper end of adapter 120 may have a first inner diameter adapted to the inner diameter of the lower end of flow conduit 10. Preferably, the inner diameters are substantially equal to each other. Preferably, the cross-sectional shapes at the interfaces between the portions also match. The lower end of adapter 120 may have a second inner diameter adapted to the diameter of the inlet face of filter 2. Preferably, the diameters are substantially equal to each other. Preferably, the cross-sectional shapes at the interfaces between the portions also match.

[0288] The first inner diameter of adapter 120 may be larger than the second inner diameter. Alternatively, the first inner diameter of adapter 120 may be smaller than the second inner diameter.

[0289] The inner surface of adapter 120 is preferably smooth and does not have cracks or abrupt shoulders that could form collection points for the dry powder 4. For example, the inner surface may smoothly transition from the first inner diameter to the second inner diameter via one or more tapered sections, such as... Figure 17 As shown.

[0290] In any of the above embodiments, the flow conduit 10 may be empty to provide an unobstructed flow path between the spray device 7 and the inlet face of the filter 2. Alternatively, the flow conduit 10 may include a flow conditioner inserted between the spray device 7 and the inlet face of the filter 2 to facilitate the dispersion of the dry powder 4. For example, the flow conditioner may include one or more of a static mixer, a mesh, a sieve, a baffle, and an orifice plate.

[0291] Figure 18 and Figure 19 An example of a flow regulator 140 in the form of a perforated disc is shown, which can be as follows: Figure 20 The device is positioned midway along the flow conduit 10 or adapter 120 to improve the uniformity of gas flow and / or gas velocity within the flow conduit 10. The orifice plate includes a body 141 having a plurality of orifices 142, which may be annular, partially annular, or other forms. Figure 19 As shown, the orifice 142 may be angled relative to the longitudinal axis of the flow regulator 10 to direct the flow of gas and dry powder 4 away from the longitudinal axis. The orifice 142 may be outwardly diverging to direct the downward flow toward the periphery of the flow regulator 10.

[0292] The flow regulator 140 can be of various sizes and can occupy part or all of the cross-section of the flow conduit 10. The flow regulator 10 can force all flow through the flow regulator 140, or allow a portion of the flow to bypass the flow regulator 140.

[0293] The flow conditioner 140 may be integral with the flow conduit 10 or the adapter 120. Alternatively, the flow conditioner 140 may be integral with the spray nozzle 25. For example, the flow conditioner 140 may form a diffuser attached to the spray nozzle 25 and positioned downstream of the nozzle outlet 51.

[0294] In alternative arrangements, such as Figure 21 As schematically shown, the flow regulator 140 can be used to discharge a mixture of gas and dry powder 4 directly from the source of dry powder 4 into the flow conduit 10, i.e., without intervening spray nozzles. For example, the dry powder can be conveyed directly from the storage unit 130 via the transfer conduit 131 (as described above) to the outlet incorporated into the flow regulator 140. In this example, the dry powder 4 can be conveyed to the outlet incorporated into the flow regulator 140 via a powder feeding system such as those available from Gema Switzerland GmbH in St. Gallen, Switzerland.

[0295] In any of the above embodiments, the size and shape of the flow duct 10 may be configured to promote uniform and preferably uniaxial flow of the primary airflow past the spray nozzle 25. For example, the inlet of the flow duct 10 may be located at a distance upstream of the spray nozzle 25 to allow the primary airflow to stabilize before reaching the spray nozzle 25. For example, the inlet of the flow duct 10 may be greater than 50 cm, optionally greater than 100 cm, and optionally greater than 140 cm before the spray nozzle 25. Additionally or alternatively, the inlet of the flow duct 10 may be oriented parallel to or minimally deviated from the longitudinal axis of the flow duct 10. For example, the inlet of the flow duct may be an inlet pipe for air intake (e.g., to the atmosphere) at an angle not exceeding 20°, optionally not exceeding 15°, and optionally not exceeding 10° to the longitudinal axis of the flow duct 10, and offset from the spray nozzle 25 at a distance of 100 cm, optionally 140 cm.

[0296] According to this disclosure, powder spraying systems and / or powder spraying nozzles can be used to produce treated filters that have one or more advantages over prior art filters.

[0297] Other aspects and implementations of this disclosure are set forth in the following provisions:

[0298] Clause A1. A powder spraying system comprising:

[0299] a) Dry powder source;

[0300] b) Spray nozzles; and

[0301] c) A supply conduit that connects the dry powder source to the spray nozzle;

[0302] The spray nozzle includes:

[0303] i) A nozzle body having a nozzle outlet;

[0304] ii) A first conduit for dry powder; and

[0305] iii) A second conduit for gas;

[0306] The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit;

[0307] The second conduit extends between the gas inlet and the gas outlet, which is located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0308] The powder outlet and the gas outlet are oriented to promote the mixing of the gas with the dry powder.

[0309] Clause A2. The powder spraying system according to Clause A1, wherein the powder outlet is located within the nozzle body upstream of the nozzle outlet, such that the initial mixing of the gas with the dry powder occurs within the nozzle body upstream of the nozzle outlet.

[0310] Clause A3. A powder spraying system according to any of the preceding clauses, wherein the gas outlet is located within the nozzle body upstream of the nozzle outlet.

[0311] Clause A4. The powder spraying system according to Clause A1, wherein the powder outlet is located at or near the nozzle outlet of the nozzle body, such that the initial mixing of the gas with the dry powder occurs outside the nozzle body.

[0312] Clause A5. The powder spraying system according to Clause A4, wherein the gas outlet is located at or near the nozzle outlet of the nozzle body.

[0313] Clause A6. A powder spraying system according to any of the preceding clauses, wherein the gas outlet includes an annular outlet surrounding the powder outlet.

[0314] Clause A7. A powder spraying system according to any of the preceding clauses, wherein the powder outlet is centrally located on the longitudinal axis of the nozzle body.

[0315] Clause A8. A powder spraying system according to any of the preceding clauses, wherein the powder outlet comprises a single powder orifice.

[0316] Clause A9. A powder spraying system according to any one of Clauses A1 to A7, wherein the powder outlet includes a plurality of powder orifices, each powder orifice being associated with the gas outlet of the second conduit.

[0317] Clause A10. The powder spraying system according to Clause A9, wherein at least one of the plurality of powder orifices is oriented along the longitudinal axis of the nozzle body.

[0318] Clause A11. A powder spraying system according to Clause A9 or Clause A10, wherein at least one of the plurality of powder orifices is oriented at a divergence angle relative to the longitudinal axis of the nozzle body.

[0319] Clause A12. The powder spraying system according to any one of Clauses A8 to A11, wherein the diameter of the powder orifice or the orifice of each powder orifice is 0.5 mm to 5.0 mm, optionally 1.0 mm to 2.5 mm, optionally 1.0 mm to 2.0 mm.

[0320] Clause A13. A powder spraying system according to any one of Clauses A8 to A12, wherein the gas outlet includes an annular orifice surrounding the associated powder orifice or each associated powder orifice.

[0321] Clause A14. The powder spraying system according to Clause A6 or Clause A13, wherein the width of the annular orifice is 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0322] Clause A15. A powder spraying system according to any of the preceding clauses, wherein the nozzle outlet is located in a first end face of the nozzle body and the powder inlet is located in a second end face opposite to the nozzle body.

[0323] Clause A16. A powder spraying system according to any of the preceding clauses, wherein the first conduit is a straight conduit between the powder inlet and the powder outlet.

[0324] Clause A17. A powder spraying system according to any of the preceding clauses, wherein the first conduit is parallel to and optionally coincides with the longitudinal axis of the nozzle body.

[0325] Clause A18. A powder spraying system according to any of the preceding clauses, wherein the first conduit includes a bore whose inner diameter decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0326] Clause A19. A powder spraying system according to any of the preceding clauses, wherein the first conduit includes a bore whose inner diameter smoothly decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0327] Clause A20. A powder spraying system according to any of the preceding clauses, wherein the first conduit includes a bore whose inner diameter is specifically reduced from a first diameter at the powder inlet to a second diameter at or near the powder outlet via one or more tapering sections.

[0328] Clause A21. A powder spraying system according to any of the preceding clauses, wherein the nozzle body includes one or more secondary gas outlets spaced apart from the nozzle outlet and oriented to guide one or more secondary gas flows to impinge on the gas and dry powder flow leaving the nozzle outlet, the impingement being outside the nozzle body and at a distance from the nozzle outlet.

[0329] Clause A22. The powder spraying system according to Clause A21, wherein the one or more secondary gas outlets are oriented to guide the one or more secondary gas flows such that they are at an angle of incidence of 30° to 90°, optionally 45° to 75°, optionally 60° with respect to the gas and dry powder flow exiting the nozzle outlet.

[0330] Clause A23. The powder spraying system according to Clause A21 or Clause A22, wherein the one or more secondary gas outlets comprise 2, 4, 6, 8 or more secondary gas outlets; and optionally, the one or more secondary gas outlets form 1, 2, 3, 4 or more pairs of secondary gas outlets, wherein each pair of secondary gas outlets comprises two secondary gas outlets located on opposite sides of the nozzle outlet.

[0331] Clause A24. The powder spraying system according to any one of Clauses A21 to A23, wherein the orifice diameter of each of the secondary gas outlets is 0.5 mm to 2.5 mm, optionally 1.0 mm to 2.5 mm.

[0332] Clause A25. A powder spraying system according to any one of Clauses A21 to A24, wherein the one or more secondary gas outlets are disposed in one or more legs projecting from the face of the nozzle body including the nozzle outlet, such that the one or more secondary gas outlets are axially located downstream of the nozzle outlet; and optionally, the one or more secondary gas outlets are located 2 mm to 20 mm, optionally 8 mm to 15 mm axially downstream of the nozzle outlet.

[0333] Clause A26. A powder spraying system according to any one of Clauses A21 to A25, wherein the nozzle body includes a third conduit separate from the second conduit for supplying gas to the secondary gas outlet.

[0334] Clause A27. A powder spraying system according to any of the preceding clauses, wherein the nozzle body includes a tubular element defining at least the powder outlet of the first conduit and a top cover element, wherein a clearance between the tubular element and the top cover element defines the gas outlet.

[0335] Clause A28. The powder spraying system according to Clause A27, wherein the clearance between the tubular element and the top cover element is 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0336] Clause A29. A powder spraying system according to any of the preceding clauses, wherein the dry powder source is aligned with the first conduit of the nozzle body, optionally wherein the dry powder source coincides with the longitudinal axis of the first conduit.

[0337] Clause A30. A powder spraying system according to any of the preceding clauses, wherein the supply conduit between the dry powder source and the spray nozzle is straight.

[0338] Clause A31. A powder spraying system according to any of the preceding clauses, wherein the inner diameter of the supply conduit between the dry powder source and the spray nozzle is 1 mm to 20 mm, optionally 5 mm to 10 mm.

[0339] Clause A32. A powder spraying system according to any of the preceding clauses, wherein the spray nozzle is oriented such that the nozzle outlet faces downward and the dry powder source is located directly above the spray nozzle.

[0340] Clause A33. The powder spraying system according to any of the preceding clauses further includes: a cleaning nozzle located within the first conduit, the cleaning nozzle being connected to a gas supply source and having an outlet oriented toward the powder outlet.

[0341] Clause A34. The powder spraying system according to Clause A33, wherein the outlet of the cleaning nozzle is located at a distance of 2 mm to 50 mm, optionally 4 mm to 25 mm, from the powder outlet.

[0342] Clause A35. A powder spraying system according to Clause A33 or Clause A34, wherein the outlet of the cleaning nozzle comprises 1 to 10, optionally 1 to 3 orifices; and optionally, the orifice or the orifice diameter of each orifice is 0.5 mm to 1.5 mm, optionally 0.5 mm.

[0343] Clause A36. A powder spraying system according to any one of Clauses A33 to A35, wherein the cleaning nozzle is configured to generate a suction force within the first conduit to facilitate the flow of dry powder through the first conduit.

[0344] Clause A37. A powder spraying system according to any one of Clauses A33 to A36, wherein the cleaning nozzle is configured to fluidize the dry powder within the first conduit.

[0345] Clause A38. A powder spraying system according to any one of Clauses A33 to A37, wherein the cleaning nozzle includes an elongated tubular element located within the first conduit to define an annular flow space of the dry powder between the outer wall of the cleaning nozzle and the inner wall of the first conduit.

[0346] Clause A39. A powder spraying system according to any of the preceding clauses, wherein the dry powder source includes a first dry powder source and a second dry powder source, and wherein the first conduit includes a first powder inlet communicating with the first dry powder source and a second powder inlet communicating with the second dry powder source; wherein the gas flowing through the second conduit and exiting the gas outlet generates a suction force at the powder outlet to facilitate the flow of the first dry powder and the second dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0347] Clause A40. The powder spraying system according to Clause A39, wherein the first conduit includes a first flow path along at least a portion of its length for the first dry powder and a second flow path along at least a portion of its length for the second dry powder, the first flow path and the second flow path being separate from each other; and optionally wherein the first flow path and the second flow path include concentrically arranged flow paths.

[0348] Clause B1. A powder spray nozzle, comprising:

[0349] i) A nozzle body having a nozzle outlet;

[0350] ii) A first conduit for dry powder; and

[0351] iii) A second conduit for gas;

[0352] The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit;

[0353] The second conduit extends between the gas inlet and the gas outlet, which is located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet.

[0354] The first conduit is a straight conduit between the powder inlet and the powder outlet.

[0355] Clause B2. The powder spray nozzle according to Clause B1, wherein the powder outlet and the gas outlet are oriented to promote mixing of the gas with the dry powder.

[0356] Clause B3. A powder spray nozzle as described in Clause B1 or Clause B2, wherein the powder outlet is located within the nozzle body upstream of the nozzle outlet, such that the initial mixing of the gas with the dry powder occurs within the nozzle body upstream of the nozzle outlet.

[0357] Clause B4. A powder spray nozzle according to any one of Clauses B1 to B3, wherein the gas outlet is located within the nozzle body upstream of the nozzle outlet.

[0358] Clause B5. A powder spray nozzle as described in Clause B1 or Clause B2, wherein the powder outlet is located at or near the nozzle outlet of the nozzle body, such that the initial mixing of the gas with the dry powder occurs outside the nozzle body.

[0359] Clause B6. A powder spray nozzle as described in Clause B5, wherein the gas outlet is located at or near the nozzle outlet of the nozzle body.

[0360] Clause B7. A powder spray nozzle according to any one of Clauses B1 to 37, wherein the gas outlet includes an annular outlet surrounding the powder outlet.

[0361] Clause B8. A powder spray nozzle according to any one of Clauses B1 to B7, wherein the powder outlet is centrally located on the longitudinal axis of the nozzle body.

[0362] Clause B9. A powder spray nozzle according to any one of Clauses B1 to 39, wherein the powder outlet comprises a single powder orifice.

[0363] Clause B10. A powder spray nozzle according to any one of Clauses B1 to 39, wherein the powder outlet includes a plurality of powder orifices, each powder orifice being associated with the gas outlet of the second conduit.

[0364] Clause B11. A powder spray nozzle as described in Clause 41, wherein at least one of the plurality of powder orifices is oriented along the longitudinal axis of the nozzle body.

[0365] Clause B12. A powder spray nozzle according to Clause 41 or Clause 42, wherein at least one of the plurality of powder orifices is oriented at a divergence angle relative to the longitudinal axis of the nozzle body.

[0366] Clause B13. A powder spray nozzle according to any one of Clauses 41 to 43, wherein the diameter of the powder orifice or each powder orifice is 0.5 mm to 5.0 mm, optionally 1.0 mm to 2.5 mm, optionally 1.0 mm to 2.0 mm.

[0367] Clause B14. A powder spray nozzle according to any one of Clauses 41 to 44, wherein the gas outlet includes an annular orifice surrounding the associated powder orifice or each associated powder orifice.

[0368] Clause B15. A powder spray nozzle as described in Clause 38 or Clause 45, wherein the width of the annular orifice is 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0369] Clause B16. A powder spray nozzle according to any one of Clauses B1 to 46, wherein the nozzle outlet is located in a first end face of the nozzle body and the powder inlet is located in a second end face opposite to the nozzle body.

[0370] Clause B17. A powder spray nozzle according to any one of Clauses B1 to 47, wherein the first conduit is a straight conduit between the powder inlet and the powder outlet.

[0371] Clause B18. A powder spray nozzle according to any one of Clauses B1 to 48, wherein the first conduit is parallel to and optionally coincides with the longitudinal axis of the nozzle body.

[0372] Clause B19. A powder spray nozzle according to any one of Clauses B1 to 49, wherein the first conduit includes a bore whose inner diameter decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0373] Clause B20. A powder spray nozzle according to any one of Clauses B1 to 50, wherein the first conduit includes a bore whose inner diameter smoothly decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

[0374] Clause B21. A powder spray nozzle according to any one of Clauses B1 to B51, wherein the first conduit includes a bore whose inner diameter is specifically reduced from a first diameter at the powder inlet to a second diameter at or near the powder outlet via one or more tapering sections.

[0375] Clause B22. A powder spray nozzle according to any one of Clauses B1 to B52, wherein the nozzle body includes one or more secondary gas outlets spaced apart from the nozzle outlet and oriented to guide one or more secondary gas flows to impinge on the gas and dry powder flow leaving the nozzle outlet, the impingement being outside the nozzle body and at a distance from the nozzle outlet.

[0376] Clause B23. The powder spray nozzle according to Clause B22, wherein the one or more secondary gas outlets are oriented to guide the one or more secondary gas flows such that they are at an angle of incidence of 30° to 90°, optionally 45° to 75°, optionally 60° with respect to the gas and dry powder flow exiting the nozzle outlet.

[0377] Clause B24. A powder spray nozzle as described in Clause B22 or B23, wherein the one or more secondary gas outlets comprise 2, 4, 6, 8 or more secondary gas outlets; and optionally, the one or more secondary gas outlets form 1, 2, 3, 4 or more pairs of secondary gas outlets, wherein each pair of secondary gas outlets comprises two secondary gas outlets located on opposite sides of the nozzle outlet.

[0378] Clause B25. A powder spray nozzle according to any one of Clauses B22 to B24, wherein the orifice diameter of each of the secondary gas outlets is 0.5 mm to 2.5 mm, optionally 1.0 mm to 2.5 mm.

[0379] Clause B26. A powder spray nozzle according to any one of Clauses B22 to B25, wherein the one or more secondary gas outlets are disposed in one or more legs projecting from the face of the nozzle body including the nozzle outlet, such that the one or more secondary gas outlets are axially located downstream of the nozzle outlet; and optionally, the one or more secondary gas outlets are located 2 mm to 20 mm, optionally 8 mm to 15 mm axially downstream of the nozzle outlet.

[0380] Clause B27. A powder spray nozzle according to any one of Clauses B22 to B26, wherein the nozzle body includes a third conduit separate from the second conduit for supplying gas to the secondary gas outlet.

[0381] Clause B28. A powder spray nozzle according to any one of Clauses B1 to B27, wherein the nozzle body includes a tubular element defining at least the powder outlet of the first conduit and a top cover element, wherein a clearance between the tubular element and the top cover element defines the gas outlet.

[0382] Clause B29. The powder spray nozzle according to Clause B28, wherein the clearance between the tubular element and the top cover element is 0.2 mm to 2.0 mm, optionally 0.2 mm to 1.0 mm, optionally 0.25 mm to 0.9 mm, optionally 0.6 mm.

[0383] Clause B30. The powder spray nozzle according to any one of Clauses B1 to B29 further comprises: a cleaning nozzle located within the first conduit, the cleaning nozzle being connected to a gas supply source and having an outlet oriented toward the powder outlet.

[0384] Clause B31. The powder spray nozzle as described in Clause B30, wherein the outlet of the cleaning nozzle is located at a distance of 2 mm to 50 mm, optionally 4 mm to 25 mm, from the powder outlet.

[0385] Clause B32. A powder spray nozzle as described in Clause B30 or Clause B31, wherein the outlet of the cleaning nozzle comprises 1 to 10, optionally 1 to 3 orifices; and optionally, the orifice or the orifice diameter of each orifice is 0.5 mm to 1.5 mm, optionally 0.5 mm.

[0386] Clause B33. A powder spray nozzle according to any one of Clauses B30 to B32, wherein the cleaning nozzle is configured to generate a suction force within the first conduit to facilitate the flow of dry powder through the first conduit.

[0387] Clause B34. A powder spray nozzle according to any one of Clauses B30 to B33, wherein the cleaning nozzle is configured to fluidize the dry powder within the first conduit.

[0388] Clause B35. A powder spray nozzle according to any one of Clauses B30 to B34, wherein the cleaning nozzle includes an elongated tubular element located within the first conduit to define an annular flow space for the dry powder between the outer wall of the cleaning nozzle and the inner wall of the first conduit.

[0389] Clause B36. A powder spray nozzle according to any one of Clauses B1 to B35, wherein the first conduit includes a first powder inlet and a second powder inlet.

[0390] Clause B37. The powder spray nozzle according to Clause B36, wherein the first conduit includes a first flow path along at least a portion of its length for a first dry powder and a second flow path along at least a portion of its length for a second dry powder, the first flow path and the second flow path being separate from each other; and optionally wherein the first flow path and the second flow path include concentrically arranged flow paths.

[0391] Clause C1. A powder spraying system according to any one of Clauses A1 to A40, wherein the dry powder comprises or consists of the following:

[0392] a) A metal compound used to form a metal oxide through thermal decomposition;

[0393] b) Metal oxides; or

[0394] c) Aerogel.

[0395] Clause C2. The powder spraying system according to Clause C1, wherein the metal compound comprises or is composed of the following: metal hydroxide, metal phosphate, metal carbonate, metal sulfate, metal perchlorate, metal iodide, metal oxalate, metal acetate, metal chlorate, or mixtures thereof.

[0396] Clause C3. The powder spraying system according to Clause C1 or C2, wherein the metal of the metal compound comprises or is composed of one or more of the following: magnesium, calcium, strontium, barium, aluminum, zirconium, manganese, lithium, iron, cobalt, nickel, copper or gallium.

[0397] Clause C4. The powder spraying system according to any one of Clauses C1 to C3, wherein the metal oxide of option c) comprises one or more pyrolytic metal oxides or pyrolytic mixed oxides, such as pyrolytic alumina, pyrolytic silicon dioxide or pyrolytic titanium dioxide.

[0398] Clause C5. A powder spraying system according to any one of Clauses C1 to C4, wherein the aerogel comprises one or more of silica aerogel, alumina aerogel, carbon aerogel, titanium dioxide aerogel, zirconium oxide aerogel, cerium dioxide aerogel, metal oxide aerogel, and mixed oxide aerogel.

[0399] Clause C6. A powder spraying system according to any one of Clauses C1 to C5, wherein the tap density of the dry powder is 1 g / cm³. 3 Up to 3g / cm 3 Optional 1.5g / cm 3 Up to 2.5g / cm 3 Approximately 2g / cm³ (optional) 3 .

[0400] Clause C7. A powder spraying system according to any one of Clauses C1 to C6, wherein the d50 (by volume) of the dry powder is less than 10 micrometers, optionally less than 5 micrometers, optionally about 2 micrometers.

[0401] Clause D1. An apparatus for treating a filter that filters particulate matter from exhaust gas, the apparatus comprising a powder spraying system according to any one of Clauses A1 to A40 or C1 to C7 or a powder spraying nozzle according to any one of Clauses B1 to B37.

[0402] Clause D2. The device according to Clause D1 further includes: a filter retainer for retaining the filter, wherein the nozzle outlet of the powder spray nozzle is oriented to spray the dry powder toward the inlet face of the filter.

[0403] Clause D3. The apparatus according to Clause D2 further includes: a vacuum generator in communication with the outlet face of the filter for generating a primary airflow through the filter, wherein the powder spray nozzle is located upstream of the inlet face of the filter and is oriented to spray the dry powder into the primary airflow upstream of the inlet face of the filter.

[0404] Clause D4. The device according to Clause D3, wherein the device further comprises: a flow duct upstream of the inlet face for guiding the primary airflow toward the inlet face of the filter; and an adapter located between the flow duct and the filter; the adapter being configured to adapt the shape and / or size of the flow duct to the shape and / or size of the inlet face of the filter.

[0405] Clause D5. The device according to Clause D4, wherein the adapter includes a tubular body having an upper seal at its upper end and a lower seal at its lower end; and wherein the upper end of the adapter has a first inner diameter adapted to the inner diameter of the lower end of the flow conduit, and the lower end of the adapter has a second inner diameter adapted to the diameter of the inlet face of the filter; and optionally wherein the first inner diameter of the adapter may be greater than or less than the second inner diameter.

[0406] Clause E1. A method for treating a filter that filters particulate matter from exhaust gas, the method comprising the steps of:

[0407] a) The dry powder is contained in the storage container;

[0408] b) Positioning a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face separated by a porous structure;

[0409] c) A primary airflow through the porous structure of the filter is established by applying a pressure reduction to the outlet surface of the filter;

[0410] d) Transferring the dry powder from the reservoir to a spray device located upstream of the inlet face of the filter via a supply conduit; and

[0411] e) Using the spraying device, spray the dry powder toward the inlet face of the filter, such that the dry powder is entrained in the primary airflow and passes through the inlet face of the filter to contact the porous structure;

[0412] The dry powder is transferred to the spraying device via the supply conduit by gravity and / or by the suction force generated within the spraying device.

[0413] Clause E2. The method according to Clause E1, wherein the dry powder is transferred to the spraying device via the supply conduit solely by gravity and / or by suction generated within the spraying device.

[0414] Clause E3. The method according to Clause E1 or Clause E2, wherein the reservoir includes a hopper for direct feeding into the supply conduit, and the dry powder can be dispensed into the hopper; optionally, wherein the dispensing is by weight of the dry powder.

[0415] Clause E4. The method according to any one of Clauses E1 to E3, wherein the spraying device includes a spray nozzle that is supplied with a pressurized gas flow along a conduit separate from the supply conduit, the pressurized gas flow being used in the spray nozzle to generate the suction force.

[0416] Clause E5. The method according to any one of Clauses E1 to E4, wherein the spraying device includes a powder spray nozzle according to any one of Clauses B1 to B37.

Claims

1. A powder spraying system, comprising: a) Dry powder source; b) Spray nozzle; and c) A supply conduit connecting the dry powder source to the spray nozzle; The spray nozzle includes: i) A nozzle body having a nozzle outlet; ii) A first conduit, the first conduit being used for dry powder; and iii) A second conduit, the second conduit being used for gas; The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit; The second conduit extends between a gas inlet and a gas outlet, the gas outlet being located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet; The powder outlet and the gas outlet are oriented to promote the mixing of the gas with the dry powder.

2. The powder spraying system according to claim 1, wherein the powder outlet comprises: Single powder hole; or Multiple powder orifices, each powder orifice associated with the gas outlet of the second conduit.

3. The powder spraying system according to claim 2, wherein the diameter of the powder orifice or the orifice of each powder orifice is from 0.5 mm to 5.0 mm.

4. The powder spraying system according to claim 2, wherein the diameter of the powder orifice or the orifice of each powder orifice is 1.0 mm to 2.5 mm.

5. The powder spraying system according to claim 2, wherein the diameter of the powder hole or the orifice of each powder hole is 1.0 mm to 2.0 mm.

6. The powder spraying system of claim 1, wherein the nozzle outlet is located in a first end face of the nozzle body and the powder inlet is located in a second end face opposite to the nozzle body.

7. The powder spraying system according to claim 1, wherein the first conduit is a straight conduit between the powder inlet and the powder outlet.

8. The powder spraying system according to claim 1, wherein the first conduit is parallel to the longitudinal axis of the nozzle body.

9. The powder spraying system of claim 8, wherein the first conduit coincides with the longitudinal axis.

10. The powder spraying system of claim 1, wherein the first conduit includes a bore, the inner diameter of which decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

11. The powder spraying system of claim 1, wherein the first conduit includes a bore, the inner diameter of which smoothly decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

12. The powder spraying system of claim 1, wherein the first conduit includes a bore whose inner diameter is specifically reduced from a first diameter at the powder inlet to a second diameter at or near the powder outlet via one or more tapering sections.

13. The powder spraying system of claim 1, wherein the nozzle body includes one or more secondary gas outlets, the one or more secondary gas outlets being spaced apart from the nozzle outlet and oriented to guide one or more secondary gas flows to impinge on the gas and dry powder flow leaving the nozzle outlet, the impingement being outside the nozzle body and at a distance from the nozzle outlet; The one or more secondary gas outlets are oriented to guide the one or more secondary gas flows such that they are at an angle of incidence of 30° to 90° with the gas and dry powder flow exiting the nozzle outlet.

14. The powder spraying system of claim 13, wherein the incident angle is 45° to 75°.

15. The powder spraying system of claim 13, wherein the incident angle is 60°.

16. The powder spraying system according to any one of claims 13 to 15, wherein the one or more secondary gas outlets comprise 2, 4, 6, 8 or more secondary gas outlets; and the one or more secondary gas outlets form 1, 2, 3, 4 or more pairs of secondary gas outlets, wherein each pair of secondary gas outlets comprises two secondary gas outlets located on opposite sides of the nozzle outlet.

17. The powder spraying system according to any one of claims 13 to 15, wherein the nozzle body includes a third conduit, the third conduit being separate from the second conduit, for supplying gas to the secondary gas outlet.

18. The powder spraying system of claim 1, wherein the dry powder source is aligned with the first conduit of the nozzle body.

19. The powder spraying system of claim 18, wherein the dry powder source coincides with the longitudinal axis of the first conduit.

20. The powder spraying system of claim 1, wherein the supply conduit between the dry powder source and the spray nozzle is straight.

21. The powder spraying system of claim 1, wherein the spray nozzle is oriented such that the nozzle outlet faces downward and the dry powder source is located directly above the spray nozzle.

22. The powder spraying system according to claim 1, further comprising: A cleaning nozzle is located within the first conduit, the cleaning nozzle is connected to a gas supply source, and has an outlet oriented toward the powder outlet.

23. The powder spraying system of claim 22, wherein the outlet of the cleaning nozzle comprises 1 to 10 orifices.

24. The powder spraying system of claim 22, wherein the outlet of the cleaning nozzle comprises one to three orifices.

25. The powder spraying system according to claim 23 or 24, wherein the orifice or the orifice diameter of each orifice is 0.5 mm to 1.5 mm.

26. The powder spraying system according to claim 23 or 24, wherein the orifice or the orifice diameter of each orifice is 0.5 mm.

27. A powder spray nozzle, comprising: i) A nozzle body having a nozzle outlet; ii) A first conduit, the first conduit being used for dry powder; and iii) A second conduit, the second conduit being used for gas; The first conduit extends between a powder inlet and a powder outlet, which are in communication with the supply conduit; The second conduit extends between a gas inlet and a gas outlet, the gas outlet being located near the powder outlet, such that the gas flowing through the second conduit and out of the gas outlet generates a suction force at the powder outlet to promote the flow of dry powder through the first conduit and out of the powder outlet and the nozzle outlet; The first conduit is a straight conduit between the powder inlet and the powder outlet.

28. The powder spray nozzle of claim 27, wherein the nozzle outlet is located in a first end face of the nozzle body and the powder inlet is located in a second end face opposite to the nozzle body.

29. The powder spray nozzle of claim 27, wherein the first conduit is parallel to the longitudinal axis of the nozzle body.

30. The powder spray nozzle of claim 29, wherein the first conduit coincides with the longitudinal axis.

31. The powder spray nozzle of claim 27, wherein the first conduit includes a bore, the inner diameter of which decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

32. The powder spray nozzle of claim 27, wherein the first conduit includes a bore, the inner diameter of which smoothly decreases from a first diameter at the powder inlet to a second diameter at or near the powder outlet.

33. The powder spray nozzle of claim 27, wherein the first conduit includes a bore whose inner diameter is specifically reduced from a first diameter at the powder inlet to a second diameter at or near the powder outlet via one or more tapering sections.

34. The powder spray nozzle of claim 27, wherein the nozzle body includes one or more secondary gas outlets spaced apart from the nozzle outlet and oriented to guide one or more secondary gas flows to impinge on the gas and dry powder flow leaving the nozzle outlet, the impingement being outside the nozzle body and at a distance from the nozzle outlet; wherein the nozzle body includes a third conduit separate from the second conduit for supplying gas to the secondary gas outlets.

35. An apparatus for treating a filter that filters particulate matter from exhaust gas, the apparatus comprising a powder spraying system according to claim 1 or a powder spraying nozzle according to claim 27.

36. The apparatus of claim 35, further comprising: A filter retainer for holding a filter, wherein the nozzle outlet of the powder spray nozzle is oriented to spray the dry powder toward the inlet face of the filter.

37. The apparatus of claim 36, further comprising: A vacuum generator, which is connected to the outlet face of the filter to generate a primary airflow through the filter, wherein the powder spray nozzle is located upstream of the inlet face of the filter and is oriented to spray the dry powder into the primary airflow upstream of the inlet face of the filter.

38. The apparatus of claim 37, wherein the apparatus further comprises: A flow duct, located upstream of the inlet face, is provided to guide the primary airflow toward the inlet face of the filter. and an adapter located between the flow conduit and the filter; The adapter is configured to adapt the shape and / or size of the flow conduit to the shape and / or size of the inlet face of the filter.

39. The device of claim 38, wherein the adapter comprises a tubular body having an upper seal at its upper end and a lower seal at its lower end; and wherein the upper end of the adapter has a first inner diameter adapted to the inner diameter of the lower end of the flow conduit, and the lower end of the adapter has a second inner diameter adapted to the diameter of the inlet face of the filter.

40. The device of claim 39, wherein the first inner diameter of the adapter is larger than the second inner diameter.

41. The device of claim 39, wherein the first inner diameter of the adapter is smaller than the second inner diameter.

42. A method for treating a filter that filters particulate matter from exhaust gas, the method comprising the steps of: a) The dry powder is contained in the storage container; b) Positioning a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face separated by a porous structure; c) A primary airflow through the porous structure of the filter is established by applying a pressure reduction to the outlet surface of the filter; d) Transferring the dry powder from the reservoir to a spray device located upstream of the inlet face of the filter via a supply conduit; as well as e) Using the spraying device, spray the dry powder toward the inlet face of the filter, such that the dry powder is entrained in the primary airflow and passes through the inlet face of the filter to contact the porous structure; The dry powder is transferred to the spraying device via the supply conduit by gravity and / or by the suction force generated within the spraying device.

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