WO2013158007A1

WO2013158007A1 - Device and method for elimination of particles from gaseous media

Info

Publication number: WO2013158007A1
Application number: PCT/SE2013/000045
Authority: WO
Inventors: Ulf Johanson; Elsie HJELM
Original assignee: Ulf Johanson; Hjelm Elsie
Priority date: 2012-04-20
Filing date: 2013-04-05
Publication date: 2013-10-24

Abstract

The present invention relates to a device for the elimination of particles present in gases, such as smoke and exhaust gases, in particular diesel engine exhaust gases and particles related to ventilation air, comprising a first pass-way (1) having a first inlet (11) for gaseous medium comprising minute particulate material, a means bringing said particles contained in the fraction of particulate material into agglomeration, a collecting means for collecting said agglomerated particles, and a particulate purified gas outlet, whereby the means for agglomeration of particles consists of a series of deflecting surfaces (2-4, 21-28, 31-38) being laterally and longitudinally displaced in relation to each other, which deflecting surfaces (2-4, 21- 28, 31-38, ) cover each 40 to 60 percent of the cross-section of said first pass-way and consists of at least three substantially parallel disposed flat baffles (2-4, 21-28, 31-38) being oblique with an angle a being 120 to 160 degrees to the axis of the said first pass-way (1) and whereby said baffles (2-4, 21-28, 31-38) in a projection of the first pass-way (1) covers the pass-way completely, and whereby the last baffle (4, 28, 38) in the flow direction is arranged to direct agglomerated particles into a second pass-way (10) for disposing said agglomerated particles and wherein a series of consecutively smaller cones (5-7) are arranged in the first pass-way (1) down-stream the parallel disposed baffles (2-4, 21-28, 31-38), whereby the cones (5-7) have their apexes directed downstream in said first pass-way (1), and whereby all but the last cone are truncated.

Description

TITLE

DEVICE AND METHOD FOR ELIMINATION OF PARTICLES FROM GASEOUS MEDIA.

DESCRIPTION

Technical field

The present invention relates to a device for the elimination of particles present in gases, such as smoke and exhaust gases, in particular diesel engine exhaust gases and particles related to ventilation air.

The object of the present invention is to obtain a device for elimination/reduction of the amount of particles in such gases in order to thereby reduce the environmental risks, in particular for those being present in ttie neighbourhood, i.e., are present close to a major road having a high traffic load.

Background of the invention

Soot, or particulate matter (PM), is produced in both gasoline and diesel-powered engines.

These engines create chemical and organic compounds from the combustion of hydrocarbon-based fuels (fossil fuels). These compounds then cluster together in particle form to create soot, which is released into the air as exhaust. Soot may also be produced as the indirect by product of nitrogen oxides (NOx) and sulphur dioxides (SOx) reacting in the atmosphere. Soot's composition often includes hundreds of different chemical elements, including sulphates, ammonium, nitrates, elemental carbon, condensed organic compounds, and even carcinogenic compounds and heavy metals such as arsenic, selenium, cadmium and zinc. One of reasons conventional diesel engines release more soot than their

conventional gasoline counterparts has to do with the way fuel is injected and ignited: on gas engines, fuel is injected during the intake stroke and ignited with a spark; on diesels, fuel is injected during the compression stroke, and the fuel ignites spontaneously from the pressure. As a result, gas engines have two emissions advantages: The ignition process is more carefully controlled and the air and fuel are more thoroughly mixed before ignition occurs, thereby reducing the amount of unburned fuel. In a conventional diesel, fuel is injected late in the cycle and the air is not as well mixed as in a gasoline engine. As a result of this less homogeneously mixed fuel and air, there are fuel-dense pockets in the combustion chamber. The consequence is that diesel engine exhaust contains incompletely burned fuel (soot) known as particulate matter.

But new engine standards alone are not enough to protect the public from diesel pollution. New standards for diesel engines will be slowly phased in over the next 10 years. Plus, the durability of diesel engines means that older, high-polluting vehicles can continue to operate for decades. Diesel soot emissions are furthered by the fuel itself, as today's conventional diesel fuel contains significantly more sulfur than does gasoline.

The exact composition of soot is difficult to characterize because different engine technologies and conditions produce different types of soot. Indeed, the smoke clouds coming from diesel engines can even have different colours. For example, blue smoke (mainly oil and unburnt fuel) can indicate a poorly serviced and/or tuned engine; black smoke (soot, oil and unburnt fuel) can indicate a mechanical fault with the engine; and white smoke (water droplets and unburnt fuel) is produced when the engine is started from cold and may disappear when the engine warms up. The soot in your neighbourhood may be different than the soot in someone else's hometown, but no matter the source and type, soot can present a grave health threat. As previously mentioned, soot particles either come directly from the tailpipe, or can be formed when tailpipe emissions of NOx and SOx react with atmospheric agents. Once formed, soot comes in many sizes, though all just a fraction of the width of a human hair, from coarse PM (less than 10 microns in diameter) to fine PM (less than 2.5 microns) to ultra fine PM (less than 0.1 microns). Most soot is in the fine and ultra fine categories, with ultra fine particles making up 80-95% of soot. Ultra fine particles are the most dangerous, however, as they are small enough to penetrate the cells of the lungs. Soot particles can have an environmental lifetime of one to three weeks, and they can travel long distances, journeying to communities in far regions. Soot particles have even been found at the South Pole, where no major emission source exists for thousands of miles. Premature deaths are a result of exposure to diesel particulate matter, both direct from the tailpipe and from the conversion of NOx emissions to particulates in the atmosphere. Estimates for indirect particulate exposure for each air basin are based on a conversion of NOx emissions to particulates. As soot travels through the air in your community, you breathe it in, and so it starts the next phase of its journey: a trip through your body's respiratory system. Large soot particles (> 0 microns) deposit in your nose, throat, and lungs, causing coughing and sore throat, and are ejected from your body through sneezing, coughing, and nose blowing. Coarse particles (10 microns) are inhaled into your windpipe and settle there, causing irritation and more coughing. Fine and ultra fine particles (less than 2.5 microns) are the most successful in invading your body, small enough to travel all the way down deep into your lungs.

Once there, these soot particles can irritate and mutate the most sensitive tissues in your lungs: your alveoli. These air sacs line your lung's alveolar ducts and are the primary gas exchange units of the lungs. Surrounded by networks of blood capillaries, alveoli exchange oxygen and carbon dioxide from the air you breathe in with blood in your capillaries, thus allowing your circulatory system to carry oxygen to the rest of your body. Soot particles, however, make this task more difficult as they cause inflammation and scarring of these alveoli. Scar tissue builds up and slows oxygen flow to your capillaries, straining your heart because it must work harder to compensate for oxygen loss.

In the end, soot travels far and wide to affect thousands of communities and millions of people, including you and your family. It begins in the combustion of an engine and ends up in the innermost reaches of individuals' lungs. Society pays a heavy price for soot's journey. Billions of dollars in health care costs, the loss of work and school days, and the loss of human lives create an enormous burden for society to shoulder. This burden is not a necessary one, however, as it can be lifted from off our backs with the help of stricter air regulations and cleaner engine technology. The diesel industry is constantly innovating new solutions to clean up existing diesel engines that run for millions of miles. Employing emissions control systems and devices, owners of diesel products are able to make the most out of their investment in diesel technology. In a white handkerchief test, a demonstration a white handkerchief remains clean even when held in front of an exhaust pipe.

High Efficiency Diesel Particulate Filters (DPFs)

High efficiency diesel particulate filter (DPF) removes PM in diesel exhaust by filtering exhaust from the engine. The filter systems can reduce PM emissions by 80 to greater than 90 percent.

Wall-Flow Diesel Particulate Filter

High efficiency filters are effective in controlling the carbon fraction of the

particulate, the portion that some health experts believe may be the PM component of the greatest concern.

Since the volume of particulate matter generated by a diesel engine is sufficient to Since the volume of particulate matter generated by a diesel engine is sufficient to fill up and plug a reasonably sized filter over time, some means of disposing of this trapped particulate must be provided. The most promising means of disposal is to burn or oxidize the particulate in the filter, thus regenerating, or cleansing, the filter. This is accomplished through the use of a catalyst placed either in front of the filter or applied directly on the filter, a fuel-borne catalyst, or burners which are used to oxidize or combust the collected particulate. Flow-Through Filters

Flow-through filter technology is a relatively new method of reducing diesel PM emissions that unlike a high efficiency DPF, does not physically "trap" and accumulate PM. Instead, exhaust flows typically through a catalyzed wire mesh or a sintered metal sheet that includes a torturous flow path, giving rise to turbulent flow conditions. Any particles that are not oxidized within the flow-through filter flow out with the rest of the exhaust. So far, there have been limited commercial use of the flow-through filters but there is an increasing interest in this technology due to its ability to significantly reduce PM emissions from older, "dirtier" diesel engines. Flow-through systems are capable of achieving PM reduction of about 30 to 70 percent.

Diesel Oxidation Catalysts (DOCs)

Like catalytic converters already used on all new gasoline vehicles, diesel oxidation catalysts (DOCs) cause chemical reactions to reduce emissions without being consumed and without any moving parts.

The exhausts of engines share similar physical and chemical characteristics with airborne materials from many sources. This makes it difficult to quantify the portion of an individual's exposure from the general environment that derives directly from engine exhausts and also complicates assessment of occupational exposures to engine exhausts.

A '"diesel particulate filter'", sometimes called a "DPF"', is device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine, most of which are rated at 85% efficiency, but often attaining efficiencies of over 90%. A diesel-powered vehicle with a filter installed will emit no visible smoke from its exhaust pipe, as >99% have a particle size of less than 1 pm (visible particles have a size of more than 30 μιτι). In addition to collecting the particulate, a method must be designed to get rid of it. Some filters are single use (disposable), while others are designed to burn off the accumulated particulate, either through the use of a catalyst (passive), or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, or through engine modifications (the engine is set to run a certain specific way when the filter load reaches a pre-determined level, either to heat the exhaust gasses, or to produce high amounts of nitrogen oxide, N02, which will oxidize the particulates at relatively low temperatures). This procedure is known as "filter regeneration." Fuel sulphur interferes with many "Regeneration" strategies, so almost all jurisdictions that are interested in the reduction of particulate emissions, are also passing regulations governing fuel sulphur levels. Particulate filters have been in use on non-road machines since 1980, and in automobiles since 1996. Diesel engines during combustion of the fuel/air mix produce a variety of particles generically classified as diesel particulate matter due to incomplete combustion. The composition of the particles varies widely dependent upon engine type, age, and the emissions specification that the engine was designed to meet, two-stroke diesel engines produce more particulate per horsepower output than do four-stroke diesel engines, as they less completely combust the fuel-air mix.

Historically diesel engine emissions were not regulated until 1987 when the first California Heavy Truck rule was introduced capping particulate emissions at 0.60 G/BHP Hour. Since then progressively tighter standards have been introduced for diesel engines.

While particulate emissions from diesel engines was first regulated in the United States, similar regulations have also been adopted by the European Union, most Asian countries, and the rest of North and South America.

While no jurisdiction has made filters mandatory, the increasingly stringent emissions regulations that engine manufactures must meet mean that eventually all on-road diesel engines will be fitted with them. Neither the American 2007 heavy truck engine emissions regulations or the European Union 2007 automobile regulations can be met without filters. PSA Peugeot was the first company to make them standard fit on passenger cars, in anticipation of the future Euro V regulations.

It is expected that non-road diesel engines will be regulated in a similar manner. As of July 2006 the California Air Resources Board is looking at introducing regulations that will require retrofit of all diesel engines operating in the state by the year 2013. Other jurisdictions may also do this. A variety of retrofit programs have been done:

2002 - In Japan the Prefecture of Tokyo passed a law banning trucks without filters from entering the city limits.

2003 - Mexico City started a program to retrofit trucks 2001 - Hong Kong retrofit program

2004 - New York City retrofit program (non-road) Variants of DPFs Unlike a catalytic converter which is a flow-through device, a DPF cleans exhaust gas by forcing the gas to flow through the filter. There are a variety of diesel particulate filter technologies on the market. Each is designed around similar requirements:

# Fine filtration

# Minimum pressure drop

# Low cost # Mass production suitability # Product durability Cordierite wall flow filters

The most common filter is made of cordierite (a ceramic material that is also used as catalytic converter supports (= cores)). Cordierite filters provide excellent filtration efficiency, are (relatively) inexpensive, and have thermal properties that make packaging them for installation in the vehicle simple. The major drawback is that cordierite has a relatively low melting point (about 1200°C) and cordierite substrates have been known to melt down during filter regeneration. This is mostly an issue if the filter has become loaded more heavily than usual, and is more of an issue with passive systems than with active systems, unless there is systems break down.

Cordierite filter cores look like catalytic converter cores that have had alternate channels plugged - the plugs force the exhaust gas flow through the wall and the particulate collects on the inlet face.

Silicon carbide wall flow filters

The second most popular filter material is silicon carbide, or SiC. It has a higher (1700°C) melting point than cordierite, however it is not as stable thermally, making packaging an issue. Small SiC cores are made of single pieces, while larger cores are made in segments, which are separated by special cement so that heat expansion of the core will be taken up by the cement, and not the package. SiC cores are usually more expensive than cordierite cores, however they are manufactured in similar sizes, and one can often be used to replace the other.

Silicon carbide filter cores also look like catalytic converter cores that have alternate channels plugged - again the plugs force the exhaust gas flow through the wall and the particulate collects on the inlet face. Metal fibre flow through filters Some cores are made from metal fibres - generally the fibres are "woven" into a monolith. Such cores have the advantage that a current can be passed through the monolith to heat the core for regeneration purposes. Metal fibre cores tend to be more expensive than cordierite or silicon carbide cores, and generally not interchangeable with them. Partial filters

There are a variety of devices that produce over 50% particulate matter filtration, but less than 85%. Partial filters come in a variety of materials. The only commonality between them is that they produce more back pressure than a catalytic converter, and less than a diesel particulate filter. Partial filter technology is popular for retrofit.

Filter usage

A properly designed filter will have little effect on fuel usage, however improper installation can be catastrophic, which is why automobile and truck engine manufacturers have avoided the use of filter technology until now. It was first offered as standard by the French manufacturer PSA Peugeot Citroen in early 2000, and has been a huge success.

Maintenance

Filters require more maintenance than catalytic converters. Engine oil ash builds up on the surface of the inlet face of the filter, and will eventually clog the pores. This increases the pressure drop over the filter, which when it reaches 100 inches of water or higher is capable of causing engine damage. Regular filter maintenance is a necessity.

Regeneration

Regeneration is the process of removing the accumulated soot from the filter. This is done either passively (by adding a catalyst to the filter) or actively. On-board active filter management can use a variety of strategies, such as engine management to increase exhaust temperature, fuel burner to increase the exhaust temperature, catalytic oxidizer to increase the exhaust temperature, resistive heating coils to increase the exhaust temperature, microwave energy to increase the exhaust temperature.

All on-board active systems use extra fuel, whether through burning to heat the DPF, or providing extra power to the DPF's electrical system. Typically a computer monitors one or more sensors that measure back pressure and/or temperature, and based on preprogrammed set points the computer makes decisions on when to activate the regeneration cycle. The additional fuel can be supplied by a metering pump. Running the cycle too often while keeping the back pressure in the exhaust system low, will use extra fuel. The reverse runs risk of engine damage and/or uncontrolled regeneration and possible DPF failure. Quality regeneration software is a necessity for longevity of the active DPF system.

Diesel particulate matter combusts at temperatures above 600°C are attained. The start of combustion causes a further increase in temperature. In some cases the combustion of the particulate matter can raise temperatures above the structural integrity threshold of the filter material, which can cause catastrophic failure of the substrate. Various strategies have been developed to limit this possibility. Note that unlike a sparkignited engine, which typically has less that 0.5% oxygen in the exhaust gas stream before the emission control device(s), many diesel engines run above 15% oxygen pre-filter. While the amount of available oxygen makes fast regeneration of a filter possible, it also contributes to run away regeneration issues.

SE-C-513 391 discloses a device for complete combustion of solid fuels and comprises two combustion chambers joined together, of which one is a combustion chamber for drying and gasification of the fuel and the second one is a final combustion chamber for combustion of the gasified fuel and whereby a ceramic filter is arranged as a partition wall between the chambers, which filter allows the gasified fuel to pass through but blocks remaining solid substance to pass into the final combustion chamber and whereby the combustion gas is forced to pass the ceramic filter whereby the combustion temperature is raised to a suitable combustion temperature. This device is meant to replace a conventional furnace.

NO-C-131 ,325 relates to a device for separating solid particles from a gas stream by direct the gas from a source to a mixing chamber where a mixture of steam and atomized liquid droplets are introduced under such conditions that the liquid droplets are accelerated to a speed of at least 60 m/s over the inlet speed, whereby solid particles are caught by the liquid droplets, whereby a subpressure is obtained in the mixing chamber. The invention is thereby related to a ration between steam and atomized droplets.

US-A-6,019,819 relates to a device catching a condensate, which condensate contains oil and other hydrocarbons from food processing, such as French frying potatoes. WO 99/56854 relates to a process for separating particles from a flow of hot gas whereby the relative humidity is primarily increased to almost saturation, then gas and particles are cooled adiabatically so that water condenses upon the particles whereupon the particle containing water is separated off. EP-A-0 1 10 438 relates to a process and a device for purification of particle containing gas by means of condensation of water onto the particles in the gas and a separation of water droplets comprising particles.

WO 2009/05 547 relates to a device for the elimination of particles from gaseous media, characterized by comprising a first pass-way having a first inlet for gaseous medium comprising minute particulate material, a means compressing the said gaseous medium bringing the fraction containing said particulate material to a return pass-way bringing said particles contained in the fraction of particulate material into agglomeration, a collecting means for collecting said agglomerated particles, a particle withdrawing means to eliminate said collected agglomerated particles, as well as those already being large, and a particulate purified gas outlet. In a preferred bringing said particles contained in the fraction of particulate material into

agglomeration.

US 6,056,798 relates to a separator for eliminating particles from a gas flow comprising a series of cylindrical tubes having decreasing diameter, each tube part having a truncated cone part overlapping a distance between the tube parts, whereby the truncated cones having a decreasing angle to the longitudinal direction of the cylindrical tubes. The interspaces between the tube parts are arranged for letting gaseous medium out.

The distribution of particles derived from a diesel engine is quite wide. Thus they range all the way from nuclei mode (10 nm) to coarse mode 10000 nm), whereby the large mass of particles is concentrated around 100 nm. However, there is a great demand for a completion of existing particles removing systems to reduce emissions of toxic particulates from in particular diesel engines, either mobile or stationary, as well as a complete cleansing of ventilation air. In particular particles having a size of less than 50 nm, more specifically less than 10 nm, still more specifically down to 1 nm or less, are of interest to be removed.

Nothing in the prior art discussed above can provide this. Summary of the present invention

The present invention relates to a device for the elimination of particles from gaseous media, characterized in that the means for agglomeration of particles consists of a series of deflecting surfaces being laterally and longitudinally displaced in relation to each other, which deflecting surfaces cover each 20 to 60 percent of the cross-section of said first pass-way and consists of at least three substantially parallel disposed flat baffles being oblique with an angle a being 120 to 160 degrees to the axis of the said first pass-way and whereby said baffles in a projection of the first pass-way covers the pass-way completely, and whereby the last baffle in the flow direction is arranged to direct agglomerated particles into a second pass-way for disposing said agglomerated particles.

The device of the invention it is arranged for agglomeration and collection of particles having a particle size less than 1 μιτι, preferably less than 0.5 μιη, more preferably less than 0.3 μιτι, further more preferably less than 0.2 μηι, even down to 10 nm or less, which particles after agglomeration have a particle size of at least 15 μιη, preferably 10 μητι, more preferably 6 μ^ηπ or less, whereby that the device further catches and makes the agglomerated particles subject to an elimination.

In a further aspect of the invention it relates to a method for the elimination of particles from gaseous media, characterized by passing said gaseous media into a means for agglomeration of particles consisting a series of deflecting surfaces (2-4), which deflecting surfaces cover each 20 to 60 percent of the cross-section of said first pass-way and consist of at least three substantially parallel disposed flat baffles being oblique with an angle a being 120 to 160 degrees to the axis of the said first pass-way, and whereby said baffles in a projection of the first pass-way covers the pass-way completely and whereby the last baffle in the flow direction direct agglomerated particles into a second pass-way for disposing said agglomerated particles.

The term minute particle refers to particles having a size of less than 0.2 μιη.

Detailed description of the present invention

The present invention will now be described in more detail with reference to the accompanying drawing, however, without being restricted to this or the embodiment being related thereto, in which drawing

FIG. 1 shows a schematic longitudinal cross-sectional view of an embodiment of the invention for treating a particle containing gaseous medium in general;

FIG. 2 shows a cross-section along line ll-ll in FIG. 1 ; FIG. 1 shows a schematic longitudinal cross-sectional view of an embodiment of the invention for treating a particle containing gaseous medium in general;

FIG. 2 shows a cross-section along line ll-ll in FIG. 1 ;

FIG. 3 shows a cross-section along line Ill-Ill in FIG. 1 ;

FIG. 4 shows a cross-section along line IV-IV in FIG. 1 ;

FIG. 5 shows a detail of the baffle set-up shown in FIG. 1 ;

FIG. 6 shows a second embodiment of the baffle set-up of the invention; and FIG. 7 shows a third embodiment of the baffle set-up of the invention. In the following in operation exhaust gases containing particles to be separated off are passed into a first inlet 1 1 of a pass-way 1 and are represented by the open arrows marked with black dotes pointing downwards. In the pass-way 1 there are arranged three inclined baffles 2, 3, 4 arranged to form an agglomeration means. The baffles 2, 3, 4 are placed in parallel with each other and are arranged displaced laterally and longitudinally in relation to each other with regard to the cross-section of the pass-way 1 in such a way that a projection of the baffles perpendicular to the direction of the pass-way fully covers the pass-way 1 . The baffles 2, 3, 4 are inclined downwards with regard to the flow of a gaseous medium. It means that the first baffle 2 being attached to the wall of the pass-way has its upper end closest to the inlet opening 1 1. The first baffle 2 closes to the said wall. The second baffle 3 is placed across the pass-way leaving a space on either side thereof to the wall. The third baffle 4 is placed to close to the opposite side of the wall of the pass-way with relation to the first baffle 2, and downstream of the first and second baffles 2, and 3. Thus each baffle 2, 3, 4 covers 20 to 60%, preferably 40 to 60% of the cross- section. The baffles 2, 3, 4 are further displaced longitudinally and laterally in relation to each other leaving a space between each other. The spaces arranged allow for a passage of gaseous medium downstream the pass-way 1. The baffles are substantially parallel to each other which here means that the outermost baffles 2 and 4 are parallel while the intermediate baffle 3 may be less oblique. Such an arrangement will further improve the elimination of particles. When the baffles 2, 3, and 4 are run in parallel the elimination grade will be 87%, which grade will be preferably 130 to 150 degrees. The angle a is given in relation to the current flow of the gaseous medium introduced in the pass-way.

Three conical parts 5, 6, 7 are arranged downstream the set of baffles 2, 3, 4. The bottom of the first conical part 5 being a truncated cone, is facing the inlet 11 of the pass-way 1 and is covering the whole pass-way . The second conical part 6 is a further truncated cone into the bottom part of which the first conical part 5 extends. The third conical part 7 is a full cone provided with an extended tubular apex 8. The second conical part 6 extends into said third conical part 7. The conical parts 5, 6, and 7 are more or less congruent. The second and third conical parts 6, and 7 are placed with a distance to the aforegoing conical part to provide a space between the conical parts to allow for a passage downstream the pass-way 1.

The third baffle 4 leads to an opening 9 in the wall of the pass-way 1 which opening 9 is the inlet of a tube 10 for disposing of particles having been agglomerated. In the embodiment of Fig. 1 this tube 10 is either connected to a filter 12 for collecting agglomerated particles or is connected to a off-gas tube 13 for example ventilation air. The choice of either filter 2, or off-gas tube 13 is made by changing, opening or closing, a valve 14 in the tube 10. When the gaseous medium having been passed through the filter 12 and being cleansed for agglomerated particles, it is returned into the pass-way 1 via a loop 15 opening into the pass-way 1.

Instead of the filter 12 or the opening into the off-gas tube 13 the tube 12 can be connected to a vacuum source, such as a vacuum cleaner (not shown) to collect agglomerated particles.

During the compression of the cross section at the conical parts as well as in outlets minute particles will become agglomerated into particles having a size of 10 microns or more. Solid arrows will indicate pass-ways of the particles separated off. Open arrows without any black dotes indicate cleaned air flows freed from particles. or more. Solid arrows will indicate pass-ways of the particles separated off. Open arrows without any black dotes indicate cleaned air flows freed from particles.

In the device according to FIG. 1 the first embodiment shows the first inlet 1 1 , preferably in the form of a pipe having any suitable cross-section which pipe may also come from a combustion engine, such as a car diesel or gasoline engine. On the opposite side to the inlet 1 1 , an exhaust opening 12 is arranged. It should be noted that the baffles 2, 3, 4, 5 are arranged at a distance from each other allowing a gaseous medium to pass in between the baffles 2 and 3, 3 and 4, and 4 and 5, respectively, and up into the upper space of the pipe 1 above the baffles, and further into the exhaust opening 16. When the gaseous medium is compressed into the smaller spaces below the baffles the superfluous amount of gaseous medium will pass out between the baffles while the particles due to their weight will end up in the particle opening 9. The particles at the opening 9 will then, due to the velocity, agglomerate into larger particles, and the agglomerated particles together with particles having a size already of considerably size, will be withdrawn from the opening 9 as mentioned above and optionally be destroyed or otherwise eliminated. The particle eliminating means of the present invention works as follows. A gaseous medium being introduced through the inlet will at first meet the baffles 2, 3, 4 at which any minute particles will agglomerate an be passed away sideways to the opening 9 and further into the tube 10, The cleansed gaseous medium, possibly containing a small residue of particles I deflected upwards and downwards between the baffles 2, 3, 4 to the conical parts 5, 6, 7, where any such remaining particles will be agglomerated and be collected in the extended apex of the third conical part 7. The amount of such agglomerated particles is deemed to be so little that an emptying of the apex is not regarded necessary during the life-time of the particle eliminating means. In case there should be a need for emptying the apex of such collected particles, these can be removed by means of a vacuum source via valve 17. The cross-area of the apex is 0.2 to 3 percent of the cross-area of the inlet of the first conical part 5. An exhaust tube 18 can be arranged opposite to the particle opening 9 through which exhaust tube 18 any larger particles that might have passed the baffles 4 and 5 can be withdrawn. In FIG. 5 showing a detail of the baffle set-up according to FIG. 1 an alternative of the fixed baffles 2, 3, and 4 is shown wherein baffle 3 has been arranged to a rotatable axis 19 whereby the baffle 3 can be used as an exhaust cut-out. In a vertical position it closes the through going passage and in a more horizontal position allows the through passage of gases.

In the second embodiment of the invention shown in FIG. 6 the first pass-way has been divided into a "dirty" zone A and a "clean" zone B. The zones A and B are divided by a set of baffles 21 , 22, 23, 24, 25, 26, 27, and 28 arranged centrally, whereby the baffles create a turbulence of the incoming air to be cleansed from particles in which turbulent air in the "dirty" zone A the agglomeration of the particles take place. The agglomerated particles are removed via the outlet 9 being arranged to direct agglomerated particles into a second pass-way (10) for disposing said agglomerated particles, and the cleansed air is removed via the "clean" zone B to be further treated in the set of conical parts 5, 6, 7, wherein optional remaining very small parts will become eliminated from the air.

In the third embodiment of the invention shown in FIG. 7 the first pass-way has been divided into a "dirty" zone A and a "clean" zone B. The zones A and B are divided by a set of baffles 3 , 32, 33a-b, 34 a-b, 35 a-b, 36 a-b, 37, and 38 arranged centrally, whereby the baffles create a turbulence of the incoming air to be cleansed from particles in which turbulent air in the "dirty" zone A the agglomeration of the particles take place. The agglomerated particles are removed via the outlet 9 being arranged to direct agglomerated particles into a second pass-way (10) for disposing said agglomerated particles, and the cleansed air is removed via the "clean" zone B to be further treated in the set of conical parts 5, 6, 7, wherein optional remaining very small parts will become eliminated from the air. In the third embodiment the resistance changes due to the displaced parts of the baffles 33a-b, 34 a-b, 35 a-b, 36 a-b.

The opening 9 may as indicated above be connected to a suction source consisting of a pump as well, which sucks particle containing gas to either a combustion source, or a deposit source, or further to a means for further compression, or when a more complete agglomeration already is at hand, for direct disposal depending on the situation and technical construction. The present invention will work within a large range of diameters of the ingoing tube, i.e., in exhaust pipes of gasoline and diesel engines to ventilation tubes in larger buildings.

The embodiments shown discloses conical parts, cones of truncated cones, but, however, the form of these deflecting parts is not of importance but they may be parts of tetrahedrons, pentahedrons, hexahedrons, etc.

The present invention is used for eliminating particles from gaseous media including smoke and exhaust gases as well as air, such as ventilation air, whereby in the latter case microscopic particles, such as allergens, bacteria and virus can be eliminated, and air of combustion comprising a lot of ground and soil derived particles.

Claims

1. A device for the elimination of particles present in gases, such as smoke and exhaust gases, in particular diesel engine exhaust gases and particles related to ventilation air, comprising a first pass-way (1) having a first inlet (11) for gaseous medium comprising minute particulate material, a means bringing said particles contained in the fraction of particulate material into agglomeration, a collecting means for collecting said agglomerated particles, and a particulate purified gas outlet, characterized in that the means for agglomeration of particles consists of a series of deflecting surfaces (2-4, 21- 28, 31-38) being laterally and longitudinally displaced in relation to each other, which deflecting surfaces (2-4, 21-28, 31-38, ) cover each 20 to 60 percent of the cross-section of said first pass-way and consists of at least three substantially parallel disposed flat baffles (2-4, 21-28, 31 -38) being oblique with an angle a being 120 to 160 degrees to the axis of the said first pass-way (1) and whereby said baffles (2-4, 21-28, 31-38) in a projection of the first pass-way (1 ) covers the pass-way completely, and whereby the last baffle (4, 28, 38) in the flow direction is arranged to direct agglomerated particles into a second pass-way (10) for disposing said agglomerated particles, and wherein a series of consecutively smaller cones (5-7) are arranged in the first pass-way (1) down-stream the parallel disposed baffles (2-4, 21-28, 31-38), whereby the cones (5-7) have their apexes directed downstream in said first pass-way (1), and whereby all but the last cone are truncated.

2. A device according to claim 1 , wherein the cones (5-7) are arranged with a distance them between to allow for a passage of a gaseous medium them between.

3. A method for the elimination of particles from gaseous media, characterized by passing said gaseous media into a means for agglomeration of particles consisting a series of deflecting surfaces (2-4, 21-28, 31-38), which deflecting surfaces (2-4, 21 -28, 31-38) cover each 20 to 60 percent of the cross-section of said first pass-way (1) and consist of at least three substantially parallel disposed flat baffles (2-4, 21 -28, 31-38) being oblique with an angle a being 120 to 160 degrees to the axis of the said first pass-way (1 ) and whereby said baffles (2-4, 21-28, 31 -38) in a projection of the first pass-way (1 ) covers the pass-way (1 ) completely, and whereby the last baffle (4, 28, 38) in the flow direction direct agglomerated particles into a second pass-way (10) for disposing said agglomerated particles and further passing the gaseous medium into a series of consecutively smaller cones (5-7) are arranged in the first pass-way (1 ) down-stream the parallel disposed baffles (2-4, 21 -28, 31 - 38), whereby the cones (5-7) have their apexes directed downstream in said first pass-way (1 ), and whereby all but the last cone are truncated for eliminating further small particles collecting those in the apex of the last cone.

4. A method according to claim 3, wherein the agglomerated particles are

transferred into a filter (12) collecting the said agglomerated particles.

5. A method according to claim 3, wherein the agglomerated particles are

sucked away for disposal.