DE102008053026A1 - Filter for filtration of dosing fluid in exhaust-gas treatment system of internal combustion engine of vehicle, has support structure supporting filtering medium to form passage path for dosing fluid flow - Google Patents

Abstract

The filter (106) has a metering tank (102) for accommodating a dosing fluid. A filtering medium is arranged in an inner side of the metering tank. A support structure supports the filtering medium to form a passage path for a dosing fluid flow. The filtering medium is arranged at a discharge opening of the metering tank, so that the dosing fluid flows through the filter medium before or during the withdrawal from the metering tank. The support structure has fins that are arranged on the filtering medium. An independent claim is also included for a method for filtration of a dosing fluid in an exhaust-gas treatment system.

Description

GENERAL PRIOR ART

FIELD OF THE INVENTION

These The invention relates to filtration and in particular to filtration of dosing fluid in an exhaust treatment system.

STATE OF THE ART

Many internal combustion engines produce nitrogen oxides (NO _x ) as a by-product of combustion. In particular, diesel engines produce a relatively large amount of NO _x during operation. Engines typically release NO _x via the exhaust flow of the engine.

NO _x is a pollutant that can exacerbate asthma, react with oxygen in the air to produce ozone, and ultimately, when dissolved in water, form nitric acid. Acid rain and smog are often attributed to the release of NO _x from internal combustion engines.

Since the release of NO _{x is} undesirable, various models have been implemented to reduce NO _x emissions. One such model is an exhaust gas treatment system by selective catalytic reduction (SCR). An SCR system reduces NO _x emissions using a chemical reaction between the exhaust gases, an additive and a catalyst. A gaseous or liquid dosing fluid (most commonly ammonia or urea) is added to the exhaust gas and absorbed on a catalyst. The dosing fluid reacts with NO _x in the exhaust gas to form harmless H ₂ O (water vapor) and N ₂ (nitrogen gas).

in the Operation closes an SCR system typically houses a vehicle Tank with dosing fluid on. The dosing fluid is removed from the tank pumped an injector into the exhaust stream. One with SCR systems The difficulty involved is contamination of the dosing fluid. These contaminants may be suspended in the dosing fluid Dirt or other foreign particles, wear fragments from elements of the SCR system, for example, small pieces from a pump impeller, or act on other material. Through these contaminants can the Dosierfluidstrom be narrowed somewhere in the SCR system, which but in particular in the injector is associated with problems. foreign substances can in the relatively small injector, causing the in the exhaust gas flow can be reduced or interrupted in taking place metering fluid stream.

Some SCR systems include paper filters in housings between the dosing fluid tank and the injector to the occurrence of contaminants in the injected Reduce dosing. Although these filters the performance of the SCR system, they also cause new difficulties. The paper filters can be contaminants only in small quantities catch, and they must therefore over the lifetime the engine regularly maintained become. This typically requires an exchange or a Cleaning the paper filter.

Additionally have the dosing fluids used in SCR systems often have a relatively high freezing point. Urea, for example, has a freezing point of about -11 degrees Celsius. When a dosing fluid is at low temperatures in the Lower filter housing can, freezes the dosing fluid in the filter housing, whereby the Dosierfluidstrom interrupted and the SCR system is often damaged. As a result of it are vehicles with SCR systems operating at low temperatures often used with heaters in the filter housings of the Equipped SCR system.

The existing solutions to Filtration of dosing fluids in SCR systems are both high in cost in terms of manufacturing as well as in terms of maintenance. A regular exchange of paper filter elements can result in high maintenance costs and by the extra Installation of a heating element in a filter housing increases the manufacturing cost of the system. These costs must ultimately by the buyers, Owners and operators of those equipped with these systems Vehicles are carried.

SUMMARY OF THE INVENTION

Out the above statements clearly shows that a Need for a device, system and method for Filtration of a dosing fluid in an SCR system consists. advantageously, be through such a device, such a system and a such a method the cost of operating and manufacturing the SCR system reduces and at the same time filters out contaminants from the dosing fluid.

The present invention has been developed in response to the prior art and in particular in response to the problems and requirements associated with the prior art that have not yet been fully solved by currently available filtration methods in exhaust treatment systems. The present invention has therefore been developed to provide a device, system and method for filtering a dosing fluid in an exhaust treatment system which can overcome and eliminate many or all of the prior art disadvantages discussed above.

It provides a filter with multiple modules configured this way they are functionally the required Be able to perform steps for the filtration of dosing fluid. These modules are described in the embodiments include a dosing tank configured to engage Dosage fluid can take a befindliches within the dosing tank Filter medium and a supporting medium supporting the filter medium around a passageway for one To form dosing fluid stream.

In an embodiment the filter medium is thus provided at an outlet opening of the dosing tank, that this Dosing fluid before or on its exit from the dosing tank Flows through the filter medium. In another embodiment the filter medium is thus provided at an inlet opening of the dosing tank, that this Dosing fluid before or during its entry into the dosing tank Flows through the filter medium. In a further embodiment includes the filter has a mounting mechanism that is configured that the Filter at an inlet port or an outlet opening of the Dosing tanks can be attached.

In an embodiment comprises the filter medium comprises polymeric, meltblown microfilaments with a essentially constant diameter. In another embodiment comprises the construction has one or more ribs provided on the filter medium are. In a further embodiment comprises the filter medium has multiple layers, each of the multiple layers has a unique and substantially constant porosity, wherein the plurality of layers are arranged so that the porosity of a Inlet of the Filters to an outlet of the Filters decreases.

In a further embodiment The filter medium may be a material selected from the following group include: nylon, polyester, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Polybutylene naphthalate (PBN), high density polypropylene, polyfluoroethylene, Polyvinylidene difluoride, poly (perfluoroalkoxy) PFA, polyisobutylene, Viton, low density polyethylene and high density polyethylene. In a further embodiment includes that Filter medium a depth filtration medium or high-volume medium.

It also becomes a filtration system of the present invention of a dosing fluid in an exhaust treatment system. The system may be characterized by a dosing fluid for an exhaust treatment system, a dosing tank configured to receive the dosing fluid Can, a filter, a pump that is configured to be the dosing fluid can be pumped, as well as being embodied by an injector that is configured is that he the metering fluid can inject into an exhaust gas stream. In one embodiment In particular, the filter in the system includes a filter medium that is provided within the dosing tank so that the dosing fluid before his Outflow from the dosing tank through the filter medium. The Filter medium may further include a support structure for supporting the Filter medium include a passageway for a To form dosing fluid stream.

The filter medium of the system may further be provided within the metering tank at an outlet opening of the metering tank so that the metering fluid in one embodiment flows through the filter medium before or at its exit from the metering tank. In another embodiment, the system may include a heater configured to heat the dosing fluid and the filter media in the dosing tank. In one embodiment of the system, the dosing fluid is a mono-nitrogen oxides (NO _x ) reducing agent. In another embodiment, the dosing fluid is selected from the group consisting of urea, ammonia, and a hydrocarbon fuel.

In another embodiment of the system, the filter medium may comprise multiple layers, wherein Each of the multiple layers is unique and essentially has constant porosity and the plurality of layers are arranged so that the porosity of a Inlet of the Filters to an outlet of the Filters decreases.

It will also a method according to the invention for filtering a dosing fluid in an exhaust treatment system presented. The method includes in the presented embodiments Essentially, the steps that are required to complete the above set out functions for the Operation of the described device and the described system perform. In one embodiment The method includes receiving a dosing fluid in one Dosing tank, where the tank contains a filter medium. The procedure can also the urge of the dosing fluid through the filter medium. In one embodiment the method further comprises causing the dosing fluid to exit from the tank.

In a further embodiment the process involves heating of the metering fluid within the metering tank. In another embodiment the method includes pumping the dosing fluid through a Return line.

It is also a method according to the invention to apply a filter for presented a dosing fluid in an exhaust treatment system. The Method in the presented embodiments includes in Essentially the steps that are required to complete the above cited Functions for the operation of the device described and the described Perform system. In one embodiment The method includes providing a filter medium with a minimum porosity, the smaller than a contaminant suspended in a dosing fluid is. In certain embodiments leg, the method continues to place the filter media within a dosing tank, with the dosing tank configured in this way is that he pick up a dosing fluid used in an exhaust treatment system can, with the filter medium is placed in such a place, that this Dosing fluid flows through the filter medium before it exits the tank.

A throughout this description, reference has been made to Features, benefits or similar linguistic expressions in no way mean that all these features and benefits, which can be realized with the present invention, from a any individual embodiment must be covered by the invention. Instead, use the linguistic expressions that are themselves to refer to features and benefits, meant that a specific feature, a specific advantage or a specific characteristic, as described in connection with an embodiment, in at least one embodiment of the present invention. The in the context of this description continuously discussed Features and benefits, as well as similar linguistic turns, can thus, without this necessarily be the case, refer to the same embodiment.

Furthermore can the described features, advantages and characteristics of the invention in in any suitable manner in one or more embodiments be summarized. For one It is understood by one skilled in the art that the invention without or one or more of the specific features or benefits of a particular embodiment can be realized. In other cases, additional features and benefits in certain embodiments not necessarily present in all embodiments must be included in the invention.

These Features and advantages of the present invention are achieved by the The description below and the appended claims illustrate and clarifies or can by the practice of the invention, as set forth below become.

BRIEF DESCRIPTION OF THE DRAWINGS

Around to illustrate the advantages of the invention, the above briefly discussed Invention with reference to specific embodiments, in the attached Drawings are shown in more detail. With the Note that this Drawings only typical embodiments of the invention and therefore in terms of the scope This invention is not limiting, is the Invention with reference to the accompanying drawings in more detail described and explained; where is:

1 a schematic block diagram showing an embodiment of a metering system for an exhaust treatment system;

2 a schematic block diagram showing an embodiment of a metering system for an exhaust treatment system in accordance with the present invention;

3 a schematic block diagram showing an embodiment of a metering tank with an internal filter in a metering system for an exhaust gas treatment system in accordance with the present invention;

4 a schematic block diagram showing an embodiment of a metering tank with internal filters in a metering system for an exhaust gas treatment system in accordance with the present invention;

5 a schematic block diagram showing an embodiment of a metering system for an exhaust treatment system using high-volume medium or depth filtration medium in accordance with the present invention;

6 a schematic block diagram showing an embodiment of a metering system for an exhaust treatment system using a high-volume filtration with increasing density in accordance with the present invention;

7 Fig. 12 is a cross-sectional view showing one embodiment of a high-volume density grading filtration system in accordance with the present invention;

8th an enlarged top view of meltblown microfilaments comprising a first layer of a meltblown filtration unit in accordance with certain embodiments of the present invention form the present invention; and

9 a schematic flow diagram showing an embodiment of a method for applying a filter for a dosing fluid in an exhaust treatment system in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The throughout this description, reference has been made to "one embodiment", or a similar linguistic turn, means that a specific characteristic, a specific construction or a specific characteristic, as in the context of the embodiment described in at least one embodiment of the present invention Invention is included. Thus, you can all phrases, such as "in one embodiment," and the like linguistic phrases, as they are throughout this description used to refer to the same embodiment, but without this necessarily must be the case.

Furthermore can the described features, constructions or characteristics of the invention in any suitable manner in one or several embodiments summarized be. In the following description are numerous specific Details presented to a thorough understanding in terms of embodiments to achieve the invention. For however, it will be understood by one skilled in the art that the invention with one or more of the specific details, or with others Procedures, components, materials, etc. are practically implemented can. In other cases will be on a detailed Presentation or a detailed Description of known constructions, materials or processes omitted, to avoid ambiguity with regard to aspects of the invention.

1 is a schematic block diagram illustrating one embodiment of a dosing system 100 for an exhaust treatment system. The dosing system 100 includes a metering tank 102 , a heater 104 , a filter 106 , a pump 108 , an injector 110 and an exhaust stream 112 , The dosing system 100 a dosing fluid injected into an exhaust gas stream 112 one to pollutants in the exhaust stream 112 to reduce.

The dosing tank 102 In one embodiment, contains a dosing fluid for use in the dosing system 100 , The dosing tank 102 can an outlet 114 through the dosing fluid from the dosing tank 102 exit. The dosing tank 102 may include any suitable material for storing the dosing fluid, such as a polymer, a metal, or the like.

The filter 106 receives dosing fluid from the dosing tank 102 , The filter 106 may be connected by a hose, a pipe, a channel or the like with the dosing tank. The filter 106 removes contaminants from the dosing fluid. The filter 106 may comprise a cellulosic material, a polymeric material, a sieve or the like.

In one embodiment, the filter includes 106 a heater 104 , which is configured so that the dosing fluid in the filter 106 can be heated. The heater 104 holds the dosing fluid in the filter 106 above the freezing temperature of the dosing fluid. In one embodiment, the heater comprises 104 an electrical resistance element that generates heat in response to passing an electrical current through the element.

The pump 108 receives dosing fluid from the filter 106 and pumps the dosing fluid throughout the system 100 , The pump 108 can through a hose, a pipe, a channel or the like with the filter 106 be connected. The pump 108 For example, in one embodiment, a diaphragm pump, peristaltic pump, or other pump commonly used in the art can be included.

The injector 110 In one embodiment, dosing fluid injects into the exhaust stream 112 one. The injector 110 may include one or more bores configured to allow the dosing fluid to flow to the exhaust 112 can be forwarded.

2 is a schematic block diagram illustrating one embodiment of a dosing system 200 for an exhaust treatment system in accordance with the present invention. The dosing system 200 can be a dosing tank 202 with an internal filter 204 , a pump 206 , an injector 208 and an exhaust stream 210 include. The dosing system 200 a dosing fluid injected into an exhaust gas stream 210 to pollutants or pollutants in the exhaust stream 210 to reduce.

In one embodiment, the dosing tank includes 202 an inlet 212 , an outlet 214 and an internal filter 204 , The dosing tank 202 receives and stores a dosing fluid and passes it to the dosing system 200 for use. The dosing fluid may be any reducing agent used to treat mono-nitrogen oxides (NO _x ) in an exhaust gas stream. The dosing fluid may be, for example, urea, ammonia, a hydrocarbon fuel or the like. The dosing tank 202 may include any suitable material for storing the dosing fluid, such as For example, a polymer, a metal or the like.

The inlet 212 receives a dosing fluid stream 216 , The dosing fluid flow 216 enters the dosing tank as shown by the dashed arrows 202 one. The outlet 214 directs other elements of the dosing system 200 a dosing fluid stream from the dosing tank 202 to.

In one embodiment, the internal filter is located 204 inside the dosing tank 202 , By the arrangement of the filter 204 inside the dosing tank 202 eliminates the need for a separate heater for the filter 204 provided. In one embodiment, the internal filter is located 204 inside the dosing tank 202 at the outlet 214 of the dosing tank 202 , In this embodiment, flows out of the dosing tank 202 exiting dosing the inner filter 204 , When the dosing fluid is the internal filter 204 flows through, contained in the dosing fluid contaminants from the internal filter 204 collected.

The internal filter 204 may include a filter medium. The filter medium may comprise any suitable medium for removing contaminants from a dosing fluid. The filter medium may comprise, for example, a cellulosic material. In another example, the filter medium may comprise a polymeric material. In one embodiment, the filter medium may comprise a meltblown, highly bulky polymer medium, as described below with reference to FIG 7 described.

In certain embodiments, the internal filter is 204 through a fastening mechanism 218 with the dosing tank 204 connected. The attachment mechanism 218 may be a clip, a hook, a lock, a thread, a hose, a pipe, a channel or other attachment mechanism 218 as known in the art. In an alternative embodiment, the internal filter 204 by welding, gluing or the like on the dosing tank 202 be attached. In yet another embodiment, the internal filter 204 integral with the dosing tank 202 be educated. The internal filter 204 For example, when molding the dosing tank 202 be formed at the same time.

The pump 206 receives dosing fluid from the dosing tank 202 and pumps the dosing fluid throughout the system 200 , The pump 206 can through a hose, a pipe, a channel or the like with the filter 204 be connected. In one embodiment, the pump 206 a diaphragm pump, peristaltic pump or other pump as commonly used in the art.

In an alternative embodiment, the pump may 206 inside the dosing tank 202 are located. The pump 206 may act on the dosing fluid before the dosing fluid the internal filter 204 flows through. In another embodiment, the pump may 206 inside the dosing tank 202 and act on the dosing fluid after passing the internal filter 204 flowed through. The pump 206 may, for example, within the inner filter 204 and the dosing fluid through the outlet 214 of the dosing tank 202 pump.

The injector 208 In one embodiment, dosing fluid injects into the exhaust stream 210 one. The injector 208 may include one or more bores configured to allow the dosing fluid to flow to the exhaust 210 is forwarded.

In certain embodiments, the dosing system 200 a return line 220 include. In certain embodiments, the return line is routed 220 Dosing fluid from the pump 206 to the dosing tank 202 back. The dosing system 200 can dosing fluid through the return line 220 then return, if it is determined that dosing fluid at this time is not in the exhaust stream 210 is injected, for example, when the engine is switched off and thus generates no exhaust gas. The used feedback line 220 can serve to the dosing fluid in the pump 206 protect from freezing when the dosing system 200 is operated in cold weather.

3 shows in a cross-sectional view of an embodiment of a metering tank 302 with an internal filter in a metering system for an exhaust treatment system in accordance with the present invention. In one embodiment, the dosing tank includes 302 an inlet 212 , an outlet 214 , an internal filter 304 and a heater 306 , The dosing tank 302 receives and stores a dosing fluid and directs it to the dosing system for use. The dosing tank 302 may include any suitable material for storing the dosing fluid, such as a polymer, a metal, or the like. In one embodiment, the inlet 212 and the outlet 214 in a similar way to those in relation to 2 configured identically numbered components.

In one embodiment, the internal filter is located 304 inside the dosing tank 302 , The internal filter 304 can be a filter medium 308 and a support structure 310 include. The internal filter 304 filters a dosing fluid flow 216 ,

The filter medium 308 can be any suitable medium for removing contaminants from a dosing fluid. The filter medium 308 For example, it may comprise a cellulosic material. In another example, the filter medium 308 a polymeric material. In one embodiment, the filter medium 308 comprise a meltblown high molecular weight polymer medium as described below with reference to 7 described. It will be understood by one skilled in the art that the filter medium 308 may include any material as used in filter media. The filter medium may include, for example, nylon, polyester, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), high density polypropylene, polyfluoroethylene, polyvinylidene difluoride, poly (perfluoroalkoxy) PFA, polyisobutylene, Viton, low density polyethylene and / or high density polyethylene.

The filter medium 308 can be from a support structure 310 be supported. In one embodiment, the support structure supports 310 the filter medium 308 to a passageway for the Dosierfluidstrom 216 to build. The support structure 310 can be adjacent surfaces of the filter medium 308 to provide a passageway for the dosing fluid flow 216 to accomplish. Within the scope of this patent specification, it is understood by a person skilled in the art that the filter medium itself, depending on its design integrity, may comprise the support structure.

The support structure 310 For example, one or more ribs on an inner surface of the filter medium 308 include. The filter medium 308 may be formed in this example as a stocking, wherein the opening of the stocking at the outlet 214 of the dosing tank 302 is attached. The inner surface of the sock-shaped filter medium 308 can be lined with one or more ribs, which is a support structure 310 which separates adjacent inner surfaces of the sock-shaped filter medium to form a passageway for a dosing fluid stream 216 to build.

In one embodiment, the heater heats 306 a dosing fluid in the dosing tank 302 , The heater 306 can also do that around the internal filter 304 heat the dosing fluid. By heating the dosing fluid, the dosing fluid is maintained above a minimum temperature required for use of the dosing fluid. For example, if urea is used as a dosing fluid, the heater may 306 Keep the dosing fluid in the tank at a temperature above the freezing point of urea, which is about -11 degrees Celsius.

4 shows a cross-sectional view of an embodiment of a metering tank 402 with internal filters in a metering system for an exhaust treatment system in accordance with the present invention. In one embodiment, the dosing tank includes 402 an inlet 212 , an outlet 214 , a Einlaßin nenfilter 404 , an outlet internal filter 406 and a heater 306 , The dosing tank 402 receives and stores a dosing fluid and directs it to the dosing system for use. The dosing tank 402 may include any suitable material for storing the dosing fluid, such as a polymer, a metal, or the like. The inlet 212 and the outlet 214 are preferably in a similar manner to those in relation to 2 configured identically numbered components. The heater 306 is preferably in a similar manner to one 3 configured identically numbered component configured.

The inlet filter 404 is in one embodiment within the dosing tank 402 , The inlet filter 404 can be a filter medium 308 and a support structure 310 include. The inlet filter 404 filters a dosing fluid flow 216 upon entering the dosing tank 402 , The filter medium 308 and the support structure 310 are preferably in a similar manner to those in relation to 3 configured identically numbered components.

In one embodiment, the inlet interior filter is located 404 inside the dosing tank 402 and is at the inlet 212 at the dosing tank 402 attached. The inlet filter 404 can be in the flow of the dosing tank 402 entering dosing 216 be positioned. In one embodiment, the inlet internal filter 404 as described above with respect to 3 be configured in a tubular shape, wherein the opening of the stocking the inlet 212 of the dosing tank 402 surrounds. In an alternative embodiment, the inlet internal filter 404 be configured basket-shaped, wherein the opening of the basket the inlet 212 surrounds.

In one embodiment, the outlet inner filter is located 406 inside the dosing tank 402 , The outlet internal filter 406 can be a filter medium 308 and a support structure 310 include. The outlet internal filter 406 filters a dosing fluid flow 216 on its exit from the dosing tank 402 , The filter medium 308 and the support structure 310 are preferably in a similar manner to those in relation to 3 configured identically numbered components.

In one embodiment, the outlet inner filter is located 406 inside the dosing tank 402 and is at the outlet 214 at the dosing tank 402 attached. The outlet internal filter 406 can in the stream of out the dosing tank 402 exiting dosing 216 be positioned. In one embodiment, the outlet internal filter 406 as described above with respect to 3 described, be configured in a tubular shape, wherein the opening of the stocking the outlet 214 of the dosing tank 402 surrounds. In an alternative embodiment, the outlet internal filter 406 be configured basket-shaped, wherein the opening of the basket to the outlet 214 surrounds.

5 shows an embodiment of a dosing system 500 for a high volume media exhaust gas treatment system in accordance with the present invention. The dosing system 500 includes a metering tank 102 , a filter housing 502 , highly voluminous medium 504 , a pump 108 , an injector 110 and an exhaust stream 112 , The dosing system 500 a dosing fluid injected into an exhaust gas stream 112 one to pollutants in the exhaust stream 112 to reduce. The dosing tank 102 , the pump 108 , the injector 110 and the exhaust stream 112 are preferably in a similar manner as with respect to 1 configured identically numbered components configured.

In one embodiment, the filter housing 502 a construction for receiving the high-volume medium or depth filtration medium 504 and a passageway ready so that the dosing fluid is the high volume medium 504 flows through. In one embodiment, the filter housing is replaced 502 a dosing fluid stream from the dosing tank 102 ,

The filter housing 502 can be designed so that it can be maintained, ie the high-volume medium or depth filtration medium 504 can out of the filter housing 502 removed and replaced. In another embodiment, the filter housing 502 removable with the dosing system 500 coupled, so that the filter housing with the associated high volume medium 504 remove and replace. In yet another embodiment, the filter housing 502 include a lifetime filter that is maintenance free under normal circumstances.

In one embodiment, the filter housing 502 in a flow passage for dosing fluid between the dosing tank 102 and the pump 108 positioned. In another embodiment, the filter housing 502 in a flow passage for dosing fluid between the pump 108 and the injector 110 positioned. In certain embodiments, the filter housing 502 further comprising a heating device.

The high-volume medium or depth filtration medium 504 is located in the flow passage for dosing fluid and removes contaminants from the dosing fluid when the fluid is the high volume medium 504 flows through. In one embodiment, the high volume medium comprises 504 a series of layers having a porosity decreasing in the direction of the dosing fluid flow passage. The high volume medium 504 is related to 7 discussed in more detail.

In one embodiment, the high volume medium comprises 504 a canister filter configuration known in the art. The high volume medium 504 may comprise a meltblown polymeric material. In one embodiment, the high volume medium or depth filtration medium 504 comprise a cellulosic material. In yet another embodiment, the high volume medium 504 a combination of materials. In one embodiment, the high volume media 504 For example, a folder paper material in a canister configuration having one or more layers of polymeric material located on an outer surface of the folder material.

6 shows an embodiment of a dosing system 600 for an exhaust treatment system using high volume density density filtration in accordance with the present invention. The dosing system 600 includes a metering tank 102 , a first filter housing 602 , highly voluminous medium 504 , a pump 108 , a second filter housing 604 , an injector 110 and an exhaust stream 112 , The dosing system 600 a dosing fluid injected into an exhaust gas stream 112 to pollutants or pollutants in the exhaust stream 112 to reduce. The dosing tank 102 , the pump 108 , the injector 110 and the exhaust stream 112 are preferably in a similar manner to those in relation to 1 configured identically numbered components. The high volume medium 504 is preferably in a similar manner to one 5 configured identically numbered component configured.

In one embodiment, the first filter housing 602 in a similar way to that 5 described filter housing 502 configured. The first filter housing 602 may be in a flow passage for dosing fluid between the dosing tank 102 and the pump 108 be provided. The first filter housing 602 can be highly voluminous medium or depth filtration medium 504 for filtration of the metering fluid. In certain embodiments, the first filter housing 602 further comprising a heating device.

In one embodiment, the second filter housing 604 in a similar way to that 5 described filter housing 502 configured. The second filter housing 604 may be in a flow passage for dosing fluid between the pump 108 and the injector 110 be provided. The second filter housing 604 can be highly voluminous medium or depth filtration medium 504 for filtration of the metering fluid. In certain embodiments, the second filter housing 604 further comprising a heating device.

As now out 7 can be seen, a high-volume, a density gradient having filtration system 700 for a dosing fluid in accordance with the present invention, generally a meltblown filtration unit 702 with meltblown multiple layers 704 . 706 and 708 with varying porosity, porosity in this context meaning the percentage of space in the layer. In fact, the change in porosity produces a corresponding change in gap or pore size, thereby providing varying filtration capabilities in the layers. This process, which relies on varying porosity or increasing the density of the filtration to vary the filtration capability of the layers, allows the use of an effective high-volume acetal filter and / or other substantially dimensionally stable thermoplastic that is compatible with various dosing fluids ,

For example, in some embodiments, a first layer 704 the meltblown filtration unit 702 include a porosity of between about 90 and 98% to allow for first small particle filtration. The first shift 704 can with a second layer 706 be coupled, which is designed so that a filtration of small particles in a reduced order of magnitude is possible. One of the second layer 706 corresponding porosity can range, for example, from about 85 to 97%. Finally, the second layer 706 the meltblown filtration unit 702 with a third layer 708 be coupled, which is designed so that a filtration of fine particles is possible. One of the third layer 708 corresponding porosity can range, for example, from about 80 to 96%. In this way, the meltblown filtration unit provides 702 In the present invention, an increasingly finer filtration of a dosing fluid ready from the first layer 704 towards the third layer 708 in one direction 216 continues to flow. Of course, it will be understood by one skilled in the art that the first layer, the second layer, and the third layer 704 . 706 and 708 the meltblown filtration unit 702 as described above, for illustrative purposes only, and that a meltblown filtration unit 702 in accordance with the present invention, may include any number of layers that can be arranged to allow for progressively finer filtration. In some embodiments, the meltblown filtration unit 702 further comprising a graduated array of meltblown microfilaments integrated as a unit so that the meltblown filtration unit 702 has substantially no individually identifiable layers. In one embodiment, the meltblown filtration unit 702 include a single layer.

In some embodiments, the meltblown filtration unit 702 with at least one general filtration element 708 coupled, which is designed for a relatively coarse filtration, which further contributes to a graded filtration effect. In certain embodiments, the meltblown filtration unit 702 between two general filtration elements 708a and 708b be added to the more sensitive meltblown layers of the meltblown filtration unit 702 essentially to encapsulate and thereby the meltblown filtration unit 702 protect as well as contribute to the overall filtration.

The general filtration element 708a and 708b may include a spunbond filtration media that is one of the classes of nonwoven fabrics in which newly formed filaments are immediately subjected to cold air treatment to stop spinning distortion of the filaments. The general filtration element 708a and 708b may have a porosity higher than one of the first layer 704 the meltblown filtration unit 702 corresponding porosity, so that the general filtration element 708a and 708b provides for preliminary filtration of relatively large particles from a fluid. The general filtration element 708a and 708b For example, it may comprise spunbonded nylon, polyester, acetal, ^Teflon®, or other spunbond filtration media, as known to those skilled in the art. The average filament diameter of such a medium may, for example, comprise about 100 μm.

8th Figure 10 is an enlarged plan view of meltblown microfilaments forming a first layer of a meltblown filtration unit in accordance with certain embodiments of the present invention. In one embodiment, a substantially dimensionally stable thermoplastic, such as acetal, may be meltblown to form microfilaments 802 with a substantially constant diameter size 804 to create. For example, in some embodiments, a diameter 804 of each microfilament range from about 2.5 to 30 microns. How out 8th can be seen, the first layer 704 of the meltblown filtration unit 702 of the present invention, a porosity 806 of about 96% to provide, based on the porosity, for a coarse filtration of a fluid. The second layer 706 , as in 7 shown, microfilaments 802 which are essentially the same diameter 804 like the in 8th have shown microfilaments. The microfilaments 802 the second layer 706 however, they may have a porosity 806 of about 94% to provide, based on the porosity, for an intermediate filtration of the dosing. In the 7 illustrated third layer 708 may finally microfilaments 802 include that in diameter 804 with the first and the second layer 704 and 706 , like out 7 can be seen, although the third layer 708 a porosity 806 of about 92% to provide high bulk filtration or depth filtration with fine porosity.

The meltblown microfilaments 802 may include polymeric, meltblown microfilaments. In certain embodiments, the microfilaments may include nylon, polyesters, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), high density polypropylene, polyfluoroethylene, polyvinylidene difluoride, poly (perfluoroalkoxy) PFA, polyisobutylene , Viton, low density polyethylene and / or high density polyethylene.

The The following schematic flow diagrams are generally as Logic flow diagrams executed. As such, the order shown and the designated refer Steps to an embodiment of the present method. Other steps and procedures that in terms of the presented method in function, logic or Impact on one or more steps or sections are equivalent, are also conceivable. Additionally serve the format used and the symbols used in the explanation the logical steps of the procedure and make in terms of The scope of the process is not limited. Although the flowcharts are different Arrow and line types, this will become the scope of protection the appropriate procedure is not limited or limited. In fact, some can Arrows or other connectors serve only the logical Display the sequence of the procedure. An arrow can, for example a waiting period or a monitoring period unspecified duration between specified steps of the described Show procedure. additionally For example, the order in which a particular procedure expires can be Strictly follow the order of the corresponding steps shown or deviate from that.

9 Figure 3 is a schematic flow diagram illustrating one embodiment of a method 900 for applying a filter for a dosing fluid in an exhaust treatment system in accordance with the present invention. The procedure 900 In certain embodiments, illustrates a method of using the system and apparatus of the foregoing Figures, and will be discussed with reference to these figures.

How out 9 As can be seen, the process begins 900 with the melt blowing 902 the microfilaments 802 , The microfilaments 802 may comprise a substantially stable thermoplastic having a substantially constant diameter, as with respect to 8th described.

Subsequently, the microfilaments 802 to a layer having a substantially constant porosity 806 shaped 904 , The microfilaments 802 can be formed into multiple layers, with each layer having a different porosity 806 having. The microfilaments, for example, to a first layer 704 , a second layer 706 and a third layer 708 are formed, each layer having an increasingly smaller porosity 806 having.

Subsequently, a plurality of meltblown layers are arranged according to their relative densities 906 to a filtration unit 702 to build. For example, the first layer 704 , the second layer 706 and the third layer 708 , as discussed above, are arranged to form a filtration unit 702 form. In one embodiment, the layers may be laminated to form a continuous filtration unit 702 to build.

Subsequently, the filtration unit 702 in a flow passageway 216 placed for dosing fluid 908 , The filtration unit 702 can be inside a dosing tank 202 placed 908 become. In another embodiment, the filtration unit 702 in the flow passageway 216 for dosing fluid outside the dosing tank, for example in a filter housing 502 , placed 908 become.

Finally, dosing fluid passes through the filter medium of the filtration unit 702 filtered 910 , The filtration 910 takes place in that contained in the dosing fluid contaminants from the layers of the filtration unit 702 be caught.

The present invention may be embodied in other specific embodiments without departing from the spirit or essential characteristics of the invention. The described embodiments are in all respects illustrative only The scope of the invention therefore will be more readily apparent from the appended claims rather than the foregoing description. All changes covered by the meaning and scope of the claims fall within its scope.

Claims (21)

Filter for filtering a dosing fluid in an exhaust treatment system, the filter comprising: a dosing tank so configured is that he can receive a dosing fluid; a filter medium that is located inside the dosing tank; and a support structure, which supports the filter medium, around a passageway for to form a dosing fluid stream. Filter according to claim 1, wherein the filter medium at an outlet of the Dosing tanks is located so that the Dosing fluid before or on its exit from the dosing tank Flows through the filter medium. Filter according to claim 1 or 2, wherein the filter medium at an inlet opening of the Dosing tanks is located so that the Dosing fluid before or during its entry into the dosing tank Flows through the filter medium. Filter according to one of the preceding claims, which further comprising a fastening mechanism configured to that the Filter at an inlet port or an outlet opening of the dosing tank can be attached. Filter according to one of the preceding claims, wherein the filter medium further comprises polymeric, meltblown microfilaments comprising a substantially constant diameter. Filter according to one of the preceding claims, wherein the support structure includes one or more ribs located on the filter medium. Filter according to one of the preceding claims, wherein the filter medium comprises a plurality of layers, each of the plurality Layers has a unique and substantially constant porosity and the plurality of layers are arranged so that the porosity of a Inlet of the Filters to an outlet of the Filters decreases. A filter according to claim 7, wherein the filter medium is a Material includes that is selected from the group is made of nylon, polyester, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), high density polypropylene, polyfluoroethylene, polyvinylidene difluoride, Poly (perfluoroalkoxy) PFA, polyisobutylene, Viton, polyethylene lower Density and high density polyethylene exists. Filter according to one of the preceding claims, wherein the filter medium is highly voluminous Medium or depth filtration medium comprises. System for the filtration of a dosing fluid in one Exhaust gas treatment system, comprising: a dosing fluid for an exhaust treatment system; one Dosing tank configured to receive the dosing fluid can; a filter that has: a filter medium that within the metering tank is provided so that the metering fluid before his Emerging from the dosing tank through which the filter medium flows; and a Support structure, which supports the filter medium, around a passageway for to form a dosing fluid stream; a pump that is configured is, that you can pump the dosing fluid; and an injector that is configured is that he the metering fluid can inject into an exhaust gas stream. The system of claim 10, wherein the filter medium located within the dosing tank at an outlet opening of the dosing tank, so that Dosing fluid before or on its exit from the dosing tank Flows through the filter medium. The system of claim 10 or 11, further comprising Heating device comprises which is configured so that the Dosing fluid and the filter medium are heated in the dosing tank. A system according to any one of claims 10 to 12, wherein the dosing fluid is a mono-nitrogen oxides (NO _x ) reducing agent. A system according to any one of claims 10 to 13, wherein the dosing fluid selected from the group is made up of urea, ammonia and a hydrocarbon fuel consists. A system according to any one of claims 10 to 14, wherein the filter medium comprising several layers, wherein Each of the multiple layers is unique and essentially constant porosity has, wherein the plurality of layers are arranged so that the porosity of a Inlet of the Filters to an outlet of the Filters decreases. A dosing fluid filter apparatus, comprising: a dosing fluid tank configured to receive a dosing fluid, wherein the dosing fluid is used in an exhaust treatment system becomes; Means located within the dosing fluid tank to filter the dosing fluid; Means for supporting the means provided within the dosing fluid tank for filtering the dosing fluid, the means for supporting forming a passageway for a dosing fluid flow passing through the means provided within the dosing fluid tank for filtration of the dosing fluid. Dosing fluid filter device according to claim 16, which furthermore means for heating of the metering fluid within the metering tank. Process for the filtration of a dosing fluid in one Exhaust gas treatment system, the method comprising: Store a dosing fluid in a dosing tank, wherein the dosing tank a Contains filter medium; Urging the Dosing fluid through the filter medium; and Causing the leakage of the dosing fluid from the tank. The method of claim 18, further comprising heating the Dosing fluid within the metering tank comprises. The method of claim 18 or 19, further comprising pumping the dosing fluid through a return line. Method for applying a filter for a dosing fluid in an exhaust treatment system, the method comprising: Provide a filter medium with a minimum porosity smaller than a contaminant in a dosing fluid; and Placing the filter medium within a dosing tank, with the dosing tank configured in this way is that he is one absorb dosing fluid used in an exhaust treatment system can, with the filter medium is placed in such a place, that this Dosing fluid flows through the filter medium before it exits the tank.