Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/022—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters characterised by specially adapted filtering structure, e.g. honeycomb, mesh or fibrous
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
  • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
  • B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
  • B01D53/9454—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific device
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/0212—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters with one or more perforated tubes surrounded by filtering material, e.g. filter candles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/0218—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters the filtering elements being made from spirally-wound filtering material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1021—Platinum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1023—Palladium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1025—Rhodium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1026—Ruthenium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1028—Iridium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/204—Alkaline earth metals
  • B01D2255/2042—Barium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/206—Rare earth metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/207—Transition metals
  • B01D2255/20707—Titanium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/207—Transition metals
  • B01D2255/20715—Zirconium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/207—Transition metals
  • B01D2255/2073—Manganese
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/207—Transition metals
  • B01D2255/20746—Cobalt
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/20—Metals or compounds thereof
  • B01D2255/207—Transition metals
  • B01D2255/20753—Nickel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/50—Zeolites
  • B01D2255/502—Beta zeolites
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/50—Zeolites
  • B01D2255/504—ZSM 5 zeolites
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/90—Physical characteristics of catalysts
  • B01D2255/92—Dimensions
  • B01D2255/9202—Linear dimensions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/90—Physical characteristics of catalysts
  • B01D2255/92—Dimensions
  • B01D2255/9205—Porosity
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2330/00—Structure of catalyst support or particle filter
  • F01N2330/10—Fibrous material, e.g. mineral or metallic wool
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2470/00—Structure or shape of gas passages, pipes or tubes
  • F01N2470/02—Tubes being perforated
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the invention relates to a purifier assembly used in the treatment of exhaust or waste gases.
• the invention also relates to a method for manufacturing and using such a purifier assembly.
• Allowable limits in the exhaust emissions of vehicles, work machines and engines have lowered and will lower in 2005-2016 such that it is necessary to use after- treatment to reach the emission limits.
• PM particu late-matter
• NO ⁇ emission limits carbon monoxide and hydrocarbon emissions can be effectively eliminated by oxidation catalysts.
• EGR exhaust gas recirculation
• NO x emissions are conventionally adjusted engine-technically and unburned emissions are removed by an oxidation catalyst.
• Diesel particulate filters are particularly utilised in vehicle targets to decrease the quantity of particles detrimental to health with conversions of over 90%.
• These conventional filters are of the wall flow type (forced flow through a porous wall) based on skin filtration in which a particle cake starts to build up on the wall of the flow channel and no great numbers of particles are accumulated within the wall after the initial accumulation.
• partially filtering filters which are also known with the name POC (partial oxidation catalyst) and their filtering capacity is about 40-70%.
• POC partial oxidation catalyst
• filtered PM soot (coal material) is thermally combusted by means of extra heat.
• Soot can be oxidised by an intensive combustion reaction with oxygen at a temperature higher than 550 0 C or slowly at lower temperatures (250-350 0 C) by means of NO 2 .
• NO 2 being formed in the oxidation catalyst oxidises soot in reasonably low temperatures (>250- 300 0 C) when the oxidation catalyst is efficient enough.
• a known continuous regenerating trap (CRT) method includes a Pt- bearing oxidation catalyst and following it an uncoated or catalyst-coated DPF (EP341832). Problems in the passive method with the conventional filter are re- lated to situations where the creation of NO 2 is not sufficient e.g. when driving in rush-hour traffic, and the method requires a fuel with very low sulphur content (S ⁇ 10 ppm) for minimising the creation of sulphate in the efficient and expensive Pt-bearing oxidation catalyst. The blocking of the DPF cannot be accepted in any situation, because it will interrupt driving.
• assemblies are also known made of steel wool, of ceramic foam, as a tapered structure, as a pipe structure coated with fibre, using electrostatic separation or wet cleaners.
• known filter assemblies on top of perforated pipe structures is wrapped fibre matting or metal wool and one or more of these structures can be installed in the whole filter assembly. It is typical that the fibre structure is uniform without intermediate spaces and the flow is controlled in the structure randomly avoiding fibre threads, the average main direction being radial. This is typical for filters based on deep filtration in which particles partially accumulate within the filter ma- terial.
• exhaust gas flows in these filters in the radial direction towards the inside of the pipe, whereby particles have sufficient room to accumulate within, on the surface of and in the open space of the assembly before the filter.
• the assembly of partial filters has been modified of the oxidation catalyst such that the separation of particles is promoted by using, instead of a ceramic or metal cell, assemblies which include various pass-through openings, claws or projections on the walls as well as throttles or filtering elements in the flow channels of the cell.
• Partial filters usually have a cellular structure which includes ax- ial open channels in the main flow direction. The main flow is similar to the one of normal catalyst assemblies, but particle separation has been enhanced by forcing the flow to partially travel in the radial direction via meshes, fibres or holes in the wall controlled by a pressure difference.
• the radial flow is usually random in different directions, whereby a vector in the direction of the main flow is on average axial.
• the basic principle is also that the flow enters from one end and exits on the opposite side from the other end of the cell which is usually circular or rectangular.
• the object of this invention is to provide a purifier assembly operating in diesel or equivalent waste gases which substantially minimises the quantity of emission components in refuse gas and induces a small pressure loss.
• the invention is characterised by features which are presented in the independent claims.
• the other claims present some advantageous embodiments of the invention.
• the purifier assembly can employ a coating which comprises catalytically active components.
• the catalyst coating enhances the oxidation of carbon monoxide, hydrocarbons, nitro- gen monoxide (NO) and particles.
• the oxidation of particles can be promoted directly or indirectly by means of NO 2 .
• the purifier assembly according to the invention is arranged with a perforated structure in an inlet pipe and/or an outlet pipe of the purifier.
• a perforated structure contained by an open channel, formed by a spiral-like flow channel which structure comprises at least two meshes in the flow channels between which and through the mesh structure a fluid is arranged to flow.
• the perforated structure is arranged e.g. from its one end in the fluid inlet pipe and/or outlet pipe and the other end of the perforated structure including one or more blocking elements to control the flow of the fluid through the perforated structure to the mesh structure and/or vice versa.
• the purifier assembly comprises the perforated structure, such as a perforated pipe, around which is installed the mesh structure made of e.g. corrugated mesh or other porous sheet or membrane, by means of which is provided the spiral-shaped, open flow channel which forces the flow to partially travel through the holes of the mesh structure. Consequently, an efficient purifier assembly is provided to remove particles and gaseous impurities.
• the purifier assembly according to the invention also provides an efficient catalytic structure in which the flow is forced to circulate spirally between the mesh sheets around the perforated structure but is also able to travel through the mesh.
• the gas mixture comprises an excess of oxygen, either continuously or on average.
• gaseous fuel e.g. methane, propane, bio- fuels
• liquid fuel light or heavy fuel oil, diesel, petrol or biofuels
• solid fuel e.g. methane, propane, bio- fuels
• the assembly can also be employed for the treatment of fluids liquiform or in gas-liquid phase, e.g. as a purifier to separate solid impurities from liquids or liquids from gas.
• the assembly can be used for some synthesis processes.
• the filter according to the invention can thus be used in completely lean conditions (excess of oxygen) or in conditions where the mixture ratio is adjusted from time to time to stoichiometric or rich for a short time.
• the adjustment of the mixture ratio and the resulting rise in temperature are carried out in order to regenerate the catalysed filter either completely or partially from particles and accumulated toxins or adsorbents.
• the fluid flow direction is in some embodiments from the perforated structure through the mesh structure.
• the fluid flow direction is in some embodiments through the mesh structure to the perforated structure.
• the flow of the fluid usually exhaust gas
• the flow of the fluid can be either from within the perforated structure through the wall outwards through the mesh structure to the housing or the other way round from the purifier housing through the mesh structure through the holes in the wall of the perforated structure within the perforated structure.
• the mesh structure can be e.g. around a perforated pipe at the end of the inlet pipe and/or outlet pipe and the other end of the perforated structure comprises a blocking element to control the flow of the fluid through the perforated structure to the mesh structure and/or vice versa.
• the blocking element of the perforated structure can be a separate part, e.g. a detach- able pipe plug, or it can be a fixed part of the perforated structure, e.g. a fixed pipe end.
• the end/ends of the mesh structure there are one or more blocking elements in order to at least partially prevent the flow of the fluid.
• the blocking elements at both ends block the by-pass flow totally or partially along the surface of the perforated pipe out or after the first mesh layers.
• the blocking element blocks up and clamps the mesh or an equivalent structure.
• the blocking element is advantageously made of the mesh structure surrounding the perforated pipe. The blocking element can clamp the channel only partially, whereby a narrow flow channel remains between the meshes.
• the temperature is higher and the purifier housing is the cleaner side. Then, particles accumulate in the pipe and in the purifier assembly on the inlet side. A possible clogging risk can be relieved by using a sufficiently sparse mesh and by wrapping less mesh around the pipe. If the purifier assembly is on the outlet side around the channel exiting the housing, there is more accumulation volume for the particles, but the temperature is lower than in the former version. The temperature is relevant when starting the oxidation of components being purified (CO, HC, NO).
• the purifier housing is a normal sound-damper structure in which can also be integrated other catalyst structures (cells and/or particle filters in which oxidation, three-way, NH 3 -SCR, HC-SCR, NO-degrading, N 2 O-removing and/or NO x - trap catalyst on the surface).
• catalyst structures cells and/or particle filters in which oxidation, three-way, NH 3 -SCR, HC-SCR, NO-degrading, N 2 O-removing and/or NO x - trap catalyst on the surface.
• a way is to combine the purifier according to the invention with a filter and/or a partial filter successively either in the same or different housing.
• the basic assembly thus comprises the perforated structure arrangeable in the fluid inlet pipe and/or outlet pipe within the purifier housing which is made e.g.
• the shape of the holes can be e.g. circular or oval or they can be e.g. elongated slots.
• the diameter of the holes, the hydraulic diameter if not a circular hole, in the perforated structure is 0.1-100 mm, such as advantageously 1-50 mm, such as e.g. 10-40 mm.
• the area of the holes is 1-95%, such as advantageously 10-70%, such as e.g. 20- 60%, of the area of the whole perforated structure.
• the holes are evenly or unevenly distributed in the perforated structure. There are holes at the point of the whole mesh structure or only in part against it.
• the perforated struc- ture against part of the mesh structure there can be a closed pipe or the fluid is able to access part of the catalyst structure directly (no pipe at that point but at both ends as support).
• the mesh structure can also be installed around some other than the circular perforated structure.
• the used perforated structure can be e.g. a sturdy mesh structure or a wall made of sintered metal.
• the perforated structure is arrangeable of its one end in the fluid inlet pipe and/or outlet pipe.
• the fluid flow pipes and the perforated structure are connectable concentrically and parallelly, whereby the pressure losses of the flow are as small as possible.
• the perforated structure is advantageously simply connectable directly to the inlet pipe and/or outlet pipe. It can also include a separate connector part with which it is easily connectable.
• the diameters of the perforated structure as well as the inlet pipe and/or outlet pipe are equal or close to each other, such as e.g. pipes installable abutting or within each other, whereby connecting is technically simple and simultaneously the pressure loss of the connection is as small as possible.
• the perforated structure forms a uniform wall through the holes of which the fluid is able to flow.
• the perforated structure has to be sturdy/rigid enough and/or its material thickness has to be sufficient to connect it to the inlet pipe and/or outlet pipe in order to provide a durable assembly.
• the mesh structure of the purifier assembly can again be relatively light-structured as there is no need to connect it to the inlet pipe and/or outlet pipe.
• the fluid inlet pipe and outlet pipe can be pipes or other structures, such as channels, sleeves or fittings, via which the fluid is controllable within the purifier assembly or out of it.
• the inlet pipe and/or outlet pipe can also be e.g. assembly openings in the purifier housing.
• the perforated structure is arranged as a part of the fluid inlet pipe and/or outlet pipe or the other way round a part of the inlet pipe and/or outlet pipe is arranged to simultaneously form the perforated structure. Then, e.g.
• the catalyst structure comprises at least two meshes which form open channels between the meshes.
• the two meshes can be two separate meshes or they can formed from e.g. a structurally continuous mesh wrapped around itself. The greatest volume and thus the easiest fluid flow channel in the structure is the space between the meshes.
• the fluid is able to circulate the open channel spirally around the perforated structure and the mesh structure.
• the mesh structure comprises channels formed by a mesh pair in which the flow is also able to travel sideways. If both meshes are corrugated and at least one mesh has a corrugation angle diverging from the main flow, the fluid is able to openly flow to one of the channels between the corrugation peak.
• the hole size and thread thickness of the mesh by changing the hole size and thread thickness of the mesh, it is possible to adjust the flow direction i.e. how much of it goes spirally around and how much of it goes directly through the mesh.
• the holes of the meshes can clog but the spiral route is still open.
• the mesh it is possible to use some other perforated sheet, mesh coated with sintered metal, fibre matting, membrane or filter paper by means of which it is possible to form an equivalent flow channel.
• this element is designated with the general term of mesh structure. Holes in these materials are equivalent to the eyes of the mesh in the later examples.
• the mesh it is also possible to combine two or more materials to provide the structure.
• the mesh structure also comprises one or more non-corrugated mesh foils, perforated foils, perforated sheets, meshes, fibre mattings, paper sheets and/or membranes.
• the mesh pair it is possible to wrap the structure of several different meshes or structures, one or more of which can also be non-corrugated.
• meshes can start at different points of the perforated structure, whereby gas is able to access directly two or more spiral-like channels from which the fluid can also be carried through the mesh. Pressure difference at different points of the structure decides the flow route of the fluid.
• One or more mesh structures can be located in parallel with each other, whereby a very long structure can be provided. Parallel meshes can also partially overlap or there is a separate clamping and blocking element between them, whereby the fluid circulates separately in each element. According to an object of the invention, it is possible to use a greater corrugation height in the inner circle than in the outer circle. Then, the mesh of the inner circle is first wrapped and then continued by wrapping the mesh of the outer circle having a different corrugation height.
• the mesh can also be wrapped in an inverse way.
• the object is to install a mesh of greater corrugation height on the inlet side of the fluid and, equivalent ⁇ , a lower mesh on the outlet side. Then, space is obtained for the accumulating soot and it does not accumulate in other structures and the flow has possibilities to spread wider in the mesh structure.
• the corrugation height in the mesh structure can be selected suitable for the target as regards the assembly, counterpres- sure and emission limits.
• the corrugation height can be the same or different in various meshes.
• the height can be varied between 0.2-200 mm, advantageously it is between 0.8-3 mm. Even a small corrugation angle creates an open flow channel, which differs from the case of mesh having been wrapped directly as a sheet around the pipe.
• the corrugation an- gle in relation to the main flow in either direction is at least in one mesh 1-90 degrees, such as 10-80 degrees, such as advantageously between 20-60 degrees.
• the corrugation angle can also be varied between -90 - +90 degrees, advantageously it is between -60 - -20 and +20 - +60 degrees.
• the minus and plus angles mean angles in the opposite directions in relation to the main flow direction. It is practical to use the same slantly corrugated mesh material, make a mesh pair of them by turning one of the meshes inside out such that the corrugation peaks are in different directions and carrying against each other. Then, an assembly according to the invention is provided of the same mesh. By using the mesh structure, it is possible to wrap the slantly corrugated cell partially against the corrugation peaks directly against the perforated structure.
• the ratio of the height and width of the corrugation can be varied at a very large range, using either low and wide corrugations or high and narrow corrugation peaks.
• the peak height of the corrugated mesh is between 0.2-200 mm, advantageously 0.8-3 mm.
• the counterpressure, the cohesion and the volume of the corrugated mesh are provided suitable for practical targets.
• the mesh structure comprises threads the thickness of which is 0.1-5 mm, advantageously between 0.1-1 mm, and holes the size of which (apparent diameter/hydraulic diameter from mesh to mesh at the middle of the meshwork) is 0.05-10 mm, advantageously 0.1-2 mm.
• the mesh can be a woven structure or a mesh matting or otherwise cohering.
• the size of the holes in the mesh is between 0.05-10 mm, advantageously between 0.1-2 mm.
• the great variation is due to the fact that there are very different targets of usage or intended uses. In very dirty targets, the mesh is coarser and the corrugation height is great and, in clean targets, the mesh is denser and the corrugation height small.
• various layers around the perforated sheet very different properties are required. If using foil or perforated foil instead of metal mesh, its thickness is in the same range as the thickness of the thread i.e. between 0.01-5 mm, advantageously between 0.02-0.2 mm.
• a mesh made of a very thin thread and/or large eyes for the corrugated mesh and a very dense mesh for the straight mesh whereby it is possible to wind the mesh at a very large corrugation angle (40-80 degrees).
• a very large corrugation angle 40-80 degrees
• fibre sheets or membranes of which an equivalent structure is made it is also possible to use above-mentioned fibre sheets or membranes of which an equivalent structure is made and they partially allow fluid through.
• An embodiment is an assembly in the inner circle of which the mesh is clamped and closed and the flow thus cannot immediately access the housing from beside the pipe.
• the mesh In the outer circle, the mesh is then partially open to the housing, whereby clogging is prevented in specific situations.
• One or both of the ends can obviously be not closed, but then the fluid is easily able to by-pass mainly the spiral structure immediately beside the pipe out or in, the counterpressure controlling the relative flow volumes.
• both ends of the mesh are totally closed, one fast in the perforated sheet and the other in the outer circle. Then, the fluid is forced to penetrate the mesh and cannot circulate the open spiral channel, but a space remains between the meshes in which particles can accumulate.
• Another advantage is that a great part of the mesh threads are not fast in each other but regularly separated from each other by corrugation.
• the fluid has a better possibility to touch the threads and more volume (collection volume, turbulent volume) is provided in the structure than by wrapping the mesh matting directly around the pipe. In open spaces, turbulence is created which enhances, inter alia, the separation of particles.
• An embodiment is to construct a very elongated perforated structure, in the example a perforated pipe, around which is wrapped a mesh structure. Consequently is provided a large open flow area which correlates with the surface area of the perforated pipe.
• fluid exhaust gas
• the di- ameter of the housing does not have to be larger than the outer diameter of the catalyst and so many mesh layers are not required as in the narrower version. If the same catalyst quantity is installed as in the narrow version, the number of layers around the perforated pipe is equivalent ⁇ decreased. The conversions of gaseous components coarsely follow the catalyst quantity.
• the long and narrow structure can also be integrated into the piping and it mostly looks like a pipe with a casing. The length of the structure could be e.g. 30-200 cm for an engine of about two litres.
• the long structure can also be assembled of parallel elements welded/connected together. There can be clamping rings at the end of each element or not until the ends of the whole mesh.
• the mesh of the purifier assembly is fastened around the perforated structure with the above clamping rings, but additionally it is possible to use welding, soldering, a thicker support mesh around the mesh coil or a metal nail or pin pushed through a larger mesh which can be fast in the inner pipe.
• the ends can have been welded.
• the clamping ring is usually welded to the other structure.
• the mesh structure can be coated with porous support material which operates as a base for active compounds which oxidise CO, hydrocarbons, NO, hydrogen, ammonia or coal.
• the hydrocarbons can also include functional groups containing oxygen, nitrogen or halogens.
• the coating is made such that the mesh holes remain at least partially open at least in one mesh.
• all the holes are substantially open. This provides the advantage that in the open channel the fluid is able to go through the mesh at every point, whereby particles remain on the surface of the mesh with great filtering efficiency.
• the fluid is driven to change to the other channel by the pressure difference between the channels, which provides efficient mass transport past the catalyst surface on the surface of the mesh.
• An assembly according to an object of the invention does not have a coating at all, whereby it only operates as a particle separator and sound damper.
• the catalyst can catalyse the reduction of NO x with hydrocarbons or ammonia, adsorb nitrogen oxides (reduction in rich conditions) or oxidise ammonia.
• the catalyst comprises in the support material aluminium, silicon, titanium oxides and/or zeolites.
• the thickness of the coating is between 1-500 micrometres, advantageously between 5-40 micrometres.
• the area of the coating is determined by used materials and is between 1-700 m 2 /g, usually between 20- 300 m 2 /g.
• the coating can be added to the purifier assembly of various sludges, sols and/or solutions by dipping, pumping, sucking and/or spraying.
• the meshes can be coated open when loose of its pair by spraying and, after that, wind the mesh and catalyst structure. Consequently, it is possible to ensure that the eyes of the mesh remain open.
• the coating can also be made totally or partially by means of volatile starting materials (CVD 1 ALE techniques).
• At least part of the mesh structure is coated with support material in which is added catalytically active compounds.
• the catalytically active compounds catalyse the oxidation and/or reduction reaction of exhaust and waste gases.
• the support material comprises aluminium oxide, silicon oxide, titanium oxide, zeolite, zirconium oxide and/or cerium oxide.
• the catalytically active compounds include platinum, palladium, rhodium, iridium, ruthenium and/or vanadium, catalyse the oxidation and/or reduction reaction of exhaust and waste gases.
• the purifier assembly there are in the flow direction upstream or downstream of the purifier assembly one or more catalysts or operational units such as an oxidation catalyst, a particle filter, a reduction catalyst of nitrogen oxides and/or some other unit used for purifying refuse gases.
• active metals can be used e.g. noble metals such as platinum (Pt), palladium (Pd), iridium (Ir) and/or rhodium (Rh) and/or ruthenium (Ru).
• the active components can be added in the coated catalyst structure by absorbing (dry, wet or chemisorption) or among coating sludge, solution or sol.
• the active components can be pre-matched in the particles of materials before coating.
• the coatings and/or absorptions employ water or other solvents or their mixtures usually in the liquid phase.
• active metal e.g. noble metal
• the first can include active metal advantageously for 0.8-3 g/dm 3 and the latter 0-0.8 g/dm 3 .
• the inner circle of which comprises a mesh containing active component and the outer circle including very little active component or not at all on the surface of the mesh (can also be without coating).
• the division of the active component in the mesh can also be inversed: Pt more in the outer circle and less in the inner circle. The aim is to add to the same structure e.g.
• Pd can be employed as an active component when the object of the catalyst coating is to catalyse the oxidation of CO and HCs and the temperatures are high in the operating or regeneration conditions.
• the gas mixture is stoichiometric or rich ( ⁇ 1), rhodium and/or palladium is used for stability, selectiv- ity and NO x reduction.
• promoters in the support material can be used e.g. vanadium (V), wolfram (W), iron (Fe), zirconium (Zr), cerium (Ce) 1 lanthanum (La), manganese (Mn) 1 cobalt, barium, strontium and/or nickel (Ni).
• the support material can also mainly consist of these promoters.
• typical NO x adsorption compounds e.g. by absorbing, whereby nitrogen oxides can be adsorbed in lean mixture and reduced during rich mixture.
• a purifier coated with catalyst according to the invention can be treated during manufacture in static or dynamic conditions with oxidising and/or reducing gas mixtures which can include air, oxygen, hydrogen, carbon monoxide, ammonia, exhaust gas, hydrocarbons, water or inert gas. With the treatments, it is also possible to form various mixed oxides between the coating compounds by employing suitable starting materials, particle sizes and finishing conditions.
• oxidising and/or reducing gas mixtures which can include air, oxygen, hydrogen, carbon monoxide, ammonia, exhaust gas, hydrocarbons, water or inert gas.
• the purifier according to the invention is thus able to decrease the emissions of refuse gases.
• good particle separating efficiency is also provided.
• the assembly is a novel kind of a partial filter structure for diesel targets, among others. This assembly is particularly well suited for the purification of the exhaust gases of small diesel engines in which it is integrateable directly to the sound-damper structure.
• the purifier also replaces normal elements used in sound damping. At its best, the purifier can be located in the same original sound damper, whereby no change is visible on the outside and no redesigning problems occur in the target of usage.
• the filtering capacity is better with the same total volume than when the same meshes were wound as a cell and the flow conveyed through the created cell from one end to the other.
• the assembly according to the invention provides great separating efficiency for the used mesh material and with relatively great corrugation height due to the forced spiral route.
• DOC oxidation catalyst
• CO, HCs and NO oxidises CO, HCs and NO. Forming NO 2 slowly oxidises coal-based particles.
• the DOC can be located in the same container or it is separate in front of a container according to the invention.
• the DOC can also be within the inlet or outlet pipe.
• the oxidation catalyst coating can also be in a structure in an inlet according to the invention and another structure uncoated or containing less active compounds according to the invention in the outlet.
• the temperature of the catalyst can also be increased externally by combusting hydrocarbons or by utilising other exothermic (heat-forming) reactions.
• Additional heat is provided by feeding fuel among the exhaust gas and/or by post-injection in the engine. At the same time, it is possible to decrease the volume of combustion air (by decreasing A/F ratio). It is also possible to provide additional heat for the regeneration of the catalyst structure by electric heating, burners and/or plasma and/or some other method heating the structure and/or soot.
• the accumulation of particles can be promoted with electrostatic methods, by using mesh pairs as charged collection meshes and by insulat- ing the meshes from the other structure and each other.
• the purifier assembly can also be coated with known compounds catalysing the combustion of soot in which the chemical element is e.g. vanadium, manganese, copper, cerium, iron or alkali/alkali earth metal.
• Figs. 1A-1C show some structures according to the invention.
• Fig. 2 shows a cross-sectional view at the point of a catalyst structure.
• Fig. 3 shows channels formed by a mesh pair in which the flow is also able to travel sideways.
• Fig. 4 shows meshes with different starting points.
• Fig. 5 shows a mesh structure formed by the mesh pair or several walls.
• Fig. 6 shows a special structure.
• Fig. 7 shows an elongated purifier assembly.
• the flow of the fluid 1 ,7 usually exhaust gas, can either be from within the pipe outwards through the mesh structure 5 or inversed from the purifier housing 8.
• the purifier assembly is within the purifier housing 8 and it is arranged in the inlet pipe 2 (Figs. 1A 1 1C) or the outlet pipe 3 (Fig. 1B).
• the blocking element 6, 9 At one end of the perforated structure 4, around which there is the spiral-like mesh structure 5, there is the blocking element 6, 9 to control the flow of the fluid 1 , 7 through the perforated structure 4 to the mesh structure 5 and/or vice versa.
• the blocking element 6 At the end of the mesh structure 5, there is the blocking element 6 in order to at least partially prevent the flow of the fluid 1 , 7.
• the blocking elements 6 at both edges block the by-pass flow totally or partially along the outer surface of the perforated pipe 4 out or after the first mesh layers.
• the blocking element 6 blocks up and clamps the mesh or an equivalent structure.
• the perforated pipe 4 is totally closed with the blocking element 6, 9, whereby the flow is forced through the perforated and catalyst structure 4, 5.
• Fig. 1A or 1B The case is of the block of the inlet or outlet pipe 2, 3 depending on which way the flow goes through the purifier assembly (Fig. 1A or 1B).
• the perforated structure 4 can be welded a plug 9 of the same material as the perforated structure 4.
• the plug can also be integrated into the closest blocking element 6 clamping the mesh structure 5.
• Fig. 1C clarifies the structure for the part of the blocking elements 6, 9.
• the perforated structure 4 of Fig. 1C is from one end an open and from the other end a closed pipe.
• arrows point the alternative flow directions of the fluid.
• Fig. 3 in the channels of the mesh structure 5 formed by the mesh pair the fluid 1 incoming in the axial direction is also advantageously able to travel sideways.
• the greatest volume and thus the easiest flow channel of the fluid 1 in the mesh structure 5 is a space formed by corrugations h-L between the meshes.
• the mesh structure 5 is wrapped around the perforated structure 5 of several different meshes or structures one or more of which are non-corrugated. A whole foil forces the flow to totally circulate on the spiral route. If many meshes are used, they can start at different points of the perforated structure, whereby gas is able to access directly two or more spiral-like channels from which the fluid can also be carried through the mesh.
• Fig. 5 describes some of the concepts.
• a corrugation width L and height e.g.
• hi relative high peak, h2 relatively low peak) in the corrugated foil can be selected suitable for the target in relation to the assembly, counterpressure and emission limits.
• the corrugation height can be the same or different in various meshes.
• the wall is usually a mesh or a foil.
• the foil can also be a smooth foil h ⁇ .
• Fig. 5 also shows a width D of the mesh.
• the direction of peaks h3, h4 of the corrugated foil is selected advantageously such that it is at an angle with the fluid flow direction.
• Fig. 5 shows two corrugated foils h3, h4 which are both at an angle with the flow direction of the fluid 1 and, furthermore, at an angle in relation to each other h3/h4. In Fig.
• the purifier assembly of Fig. 6 is a specific special structure in which the blocking ring 6 only closes the inner circle of the mesh structure 5 and from the outer circle the fluid is able to exit from the side to the housing 8. The flow can also be in- versed i.e. from the housing 8 through the mesh structure 5 to the perforated structure 4.
• the purifier assembly of Fig. 7 is an elongated purifier assembly within the purifier housing 8 which comprises a relatively great open flow area which correlates with the surface area of the perforated structure 4.
• the purifier assembly according to the invention (code NOC) was manufactured by using a slantly corrugated mesh foil which was wound for five overlapping meshes around the perforated pipe such that the outer diameter of the structure was 90 mm and its length 130 mm.
• the pipe diameter was 55 mm
• holes were 10 x 50 mm
• the area of the holes was about 45% of the total area of the perforated pipe.
• the corrugation height was about 1.3 mm
• width about 2.5 mm
• the volume of the catalyst layer was 0.52 litres.
• the thread thickness was about 110 ⁇ m and there were about 34 threads at the distance of one centimetre (87 mesh).
• the structure was coated by spraying in the mesh support material having a large area in which the main component was aluminium oxide and it further contained as promoters ZSM-5 and Beta zeolite (Si/AI 2 >25), TiO 2 , CeO 2 and ZrO 2 , for the total of about 40%.
• the support material included particles of both small ( ⁇ 2 ⁇ m) and large (>2 ⁇ m) particle size.
• the eyes of the mesh remained totally open, because the quantity of the coating was about 10 g/litre and the eye diameter (from mesh edge to mesh edge) before coating about 180 ⁇ m.
• As an active component Pt was absorbed in the support material for 0.53 g/litre i.e. the total of about 0.27 g of Pt.
• exhaust gas is able to travel in the assembly also through the mesh, which intensifies particle separation.
• the perforated pipe was connected
• a Fiat Doblo (1.9 I) was the vehicle which was driven within the European passenger-car test cycle (EDC) settings.
• EDC European passenger-car test cycle
• DOC oxidation catalyst
• the cellular structure of which was made of metal foil the volume was 0.52 litres
• the cell number was 120 cpsi (cells per in 2 )
• the coating volume was about 110 g/l and Pt charge 3.2 g/l.
• the consistency of the coating was similar to the one in the catalyst according to the invention.
• the purpose of the oxidation catalyst is to intensify the operation of gaseous components (the oxidation of CO, HC and NO), because the assembly according to the invention solely has quite little coating and Pt.
• the assembly according to the invention was tested using both flow directions of Fig. 1.
• the catalyst according to the invention with the oxidation catalyst provided the conversions of 63% of CO, 55% of THC and 53% of PM with the assembly according to Fig. 1A.
• the assembly according to Fig. 1 B with the oxidation catalyst provided the conversions of 63% of CO, 59% of THC and 45% of PM.
• the conversions were: CO 56%, THC 37% and PM 26%. NO x conversions cannot be considerable in these conditions and the measuring result was even negative which can result from measurement variation.
• the PM, THC and CO conversions are good when keeping in mind that the temperatures are clearly below 200 0 C for the first 800 seconds in the cycle with the duration of about 1 ,200 s.

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• 2009
  • 2009-06-29 FI FI20095735A patent/FI20095735A0/fi not_active Application Discontinuation
• 2010
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  • 2010-06-28 WO PCT/FI2010/050555 patent/WO2011001027A1/en active Application Filing
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