ITRE20080068A1 - '' PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES '' - Google Patents
'' PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES '' Download PDFInfo
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- ITRE20080068A1 ITRE20080068A1 IT000068A ITRE20080068A ITRE20080068A1 IT RE20080068 A1 ITRE20080068 A1 IT RE20080068A1 IT 000068 A IT000068 A IT 000068A IT RE20080068 A ITRE20080068 A IT RE20080068A IT RE20080068 A1 ITRE20080068 A1 IT RE20080068A1
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- IT
- Italy
- Prior art keywords
- filter element
- additive
- polymeric material
- exhaust gases
- plant
- Prior art date
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- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 title claims description 55
- 239000007789 gas Substances 0.000 title claims description 25
- 230000009467 reduction Effects 0.000 title description 8
- 239000000654 additive Substances 0.000 claims description 37
- 230000000996 additive effect Effects 0.000 claims description 37
- 239000000463 material Substances 0.000 claims description 22
- 238000002485 combustion reaction Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 238000001914 filtration Methods 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 239000004743 Polypropylene Substances 0.000 claims description 4
- -1 polypropylene Polymers 0.000 claims description 4
- 229920001155 polypropylene Polymers 0.000 claims description 4
- 238000006722 reduction reaction Methods 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 9
- 229910001868 water Inorganic materials 0.000 description 9
- 239000003054 catalyst Substances 0.000 description 8
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 7
- 239000004202 carbamide Substances 0.000 description 7
- 239000007788 liquid Substances 0.000 description 6
- 229910021529 ammonia Inorganic materials 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 235000019892 Stellar Nutrition 0.000 description 4
- 229920002678 cellulose Polymers 0.000 description 4
- 239000001913 cellulose Substances 0.000 description 4
- 238000010531 catalytic reduction reaction Methods 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 239000013043 chemical agent Substances 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 208000017667 Chronic Disease Diseases 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical class [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/40—Nitrogen compounds
- B01D2257/404—Nitrogen oxides other than dinitrogen oxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/01—Engine exhaust gases
- B01D2258/012—Diesel engines and lean burn gasoline engines
-
- 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
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
-
- 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
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
-
- 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
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1406—Storage means for substances, e.g. tanks or reservoirs
-
- 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
Description
DESCRIZIONE DESCRIPTION
del Brevetto Italiano per Invenzione Industriale dal titolo: of the Italian Patent for Industrial Invention entitled:
?IMPIANTO PER LA RIDUZIONE DEGLI OSSIDI DI AZOTO NEI GAS DI SCARICO? ? PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN THE EXHAUST GAS?
La presente invenzione riguarda in generale gli impianti per la Riduzione Selettiva Catalitica (SCR) degli ossidi di azoto nei gas di scarico prodotti da una combustione, in particolare dalla combustione della miscela aria/combustibile all?interno di un motore a combustione interna di un veicolo. The present invention generally relates to systems for the Selective Catalytic Reduction (SCR) of nitrogen oxides in the exhaust gases produced by combustion, in particular by the combustion of the air / fuel mixture inside an internal combustion engine of a vehicle. .
La Riduzione Selettiva Catalitica (SCR) ? un processo chimico per l?abbattimento delle emissioni di ossidi di azoto (NOx), in cui un reagente chimico, tipicamente un agente riducente azotato come ad esempio l?ammoniaca o l?urea, viene aggiunto ai gas di scarico in modo da reagire con gli ossidi di azoto in essi contenuti, dando origine ad azoto molecolare (N2) ed acqua (H2O). Selective Catalytic Reduction (SCR)? a chemical process for the abatement of nitrogen oxide (NOx) emissions, in which a chemical reagent, typically a nitrogen reducing agent such as ammonia or urea, is added to the exhaust gases in order to react with the nitrogen oxides contained in them, giving rise to molecular nitrogen (N2) and water (H2O).
L?agente chimico riducente viene aggiunto ai gas di scarico in presenza di un opportuno catalizzatore, il quale permette che la riduzione degli ossidi di azoto abbia luogo a temperature minori (comunque superiori a 250?C) e con rendimenti di riduzione pi? elevati, rispetto a quanto accadrebbe se la riduzione avvenisse spontaneamente senza catalizzazione. The reducing chemical agent is added to the exhaust gases in the presence of a suitable catalyst, which allows the reduction of nitrogen oxides to take place at lower temperatures (in any case higher than 250 ° C) and with higher reduction efficiency. high, compared to what would happen if the reduction occurred spontaneously without catalyzing.
Sui veicoli con motore a combustione interna, l?agente chimico riducente ? generalmente fornito sotto forma di un additivo che prende il nome di AdBlue. On vehicles with internal combustion engines, the reducing chemical agent? generally supplied in the form of an additive called AdBlue.
Questo additivo ? un liquido stabile e incolore, simile all?acqua, composto per il 32,5% da urea e per il resto da acqua deionizzata. Si tratta di un liquido a bassa tossicit?, che non comporta rischi di malattie croniche, che non ? infiammabile n? esplosivo, ed ? perci? facilmente trasportabile all?interno di un semplice serbatoio posto a bordo del veicolo. This additive? a stable and colorless liquid, similar to water, composed of 32.5% urea and the rest of deionized water. It is a low toxic liquid, which does not involve the risk of chronic diseases, which does not? flammable n? explosive, and? why? easily transportable inside a simple tank placed on board the vehicle.
L?additivo viene iniettato nel flusso dei gas di scarico attraverso una linea di alimentazione che sfocia direttamente nel tubo di scappamento, a monte di un catalizzatore (SCR Catalyst) che serve per accelerare la riduzione degli ossidi di azoto, e che ? integrato nella marmitta. The additive is injected into the exhaust gas stream through a supply line that flows directly into the exhaust pipe, upstream of a catalyst (SCR Catalyst) which serves to accelerate the reduction of nitrogen oxides, and what? integrated in the muffler.
Il flusso di gas di scarico entra in circolo all?ingresso del catalizzatore, in modo da scaldarlo rapidamente dopo l?avviamento del motore, sino a raggiungere le temperature relativamente elevate (oltre 250?C) che sono necessarie per innescare la reazione di riduzione degli ossidi di azoto. The flow of exhaust gas enters the circulation at the inlet of the catalyst, in order to heat it rapidly after starting the engine, until it reaches the relatively high temperatures (over 250 ° C) which are necessary to trigger the reduction reaction of the nitrogen oxides.
Quando l?additivo liquido entra nel tubo di scappamento, l?urea in esso contenuta si decompone in ammoniaca ed anidride carbonica. L?ammoniaca ? il reagente che riduce gli NOx dando origine ad azoto molecolare ed acqua. When the liquid additive enters the exhaust pipe, the urea contained in it decomposes into ammonia and carbon dioxide. The ammonia? the reagent that reduces NOx giving rise to molecular nitrogen and water.
La linea di alimentazione dell?additivo comprende schematicamente un serbatoio di contenimento, ed una pompa atta ad aspirare l?additivo contenuto nel serbatoio e a convogliarlo verso una valvola di dosaggio, che lo inietta in quantit? dosate all?interno del tubo di scappamento. The additive feed line schematically includes a containment tank, and a pump suitable for sucking the additive contained in the tank and conveying it to a metering valve, which injects it in large quantities. dosed inside the exhaust pipe.
Lungo la linea di alimentazione ? presente anche un filtro, il quale ? di norma posto a monte della pompa, per filtrare l?additivo liquido. Along the power line? there is also a filter, which? normally placed upstream of the pump, to filter the liquid additive.
Il filtro comprende un involucro esterno dotato di un ingresso e di un?uscita per l?additivo, all?interno del quale ? accolto un elemento filtrante atto ad essere attraversato dall?additivo per trattenere le impurit? in esso eventualmente presenti. The filter includes an external casing equipped with an inlet and an outlet for the additive, inside which? received a filter element capable of being crossed by the additive to retain impurities possibly present in it.
L?elemento filtrate ? solitamente un setto di superficie plissettato e con geometria stellare, il quale ? realizzato con un materiale a base di cellulosa. The element filtered? usually a pleated surface septum with stellar geometry, which? made with a cellulose-based material.
Detto materiale a base di cellulosa tende tuttavia a rammollire e a deteriorarsi rapidamente quando viene bagnato con acqua o con soluzioni acquose, per cui la sua efficienza e la sua durata nella filtrazione dell?additivo utilizzato nel processo SCR risultano di fatto molto basse. However, said cellulose-based material tends to soften and deteriorate rapidly when wetted with water or aqueous solutions, so that its efficiency and duration in the filtration of the additive used in the SCR process are in fact very low.
In particolare, un setto a geometria stellare realizzato con detto materiale tende rapidamente a deformarsi, perdendo la pieghettatura imposta, ed assumendo una forma indefinita che limita fortemente la superficie filtrante disponibile. In particular, a stellar geometry septum made with said material tends to deform rapidly, losing the required pleating, and assuming an indefinite shape which strongly limits the available filtering surface.
Per fronteggiare questo inconveniente, il materiale di cellulosa del setto filtrante viene sovente trattato con delle sostanze atte ad aumentarne la compatibilit? con l?additivo, ossia ad aumentare la sua resistenza e la sua stabilit? nel tempo quando viene utilizzato con l?additivo in questione. To cope with this drawback, the cellulose material of the filtering septum is often treated with substances suitable for increasing its compatibility. with the additive, ie to increase its resistance and its stability? over time when used with the additive in question.
Siccome tuttavia la soluzione di acqua e urea ? corrosiva, la stabilit? nel tempo del setto filtrante non pu? essere garantita neppure se il materiale a base di cellulosa viene trattato con le suddette sostanze. As however the solution of water and urea? corrosive, the stability? in the time of the filtering septum can not? not be guaranteed even if the cellulose-based material is treated with the aforementioned substances.
Scopo della presente invenzione ? quello di risolvere questo inconveniente, nell?ambito di una soluzione semplice, razionale e dal costo contenuto. Purpose of the present invention? that of solving this drawback, in the context of a simple, rational and low-cost solution.
Tale scopo ? raggiunto dalle caratteristiche dell?invenzione riportate nelle rivendicazioni indipendenti. Le rivendicazioni dipendenti delineano aspetti preferiti e/o particolarmente vantaggiosi dell?invenzione. Such purpose? achieved by the features of the invention reported in the independent claims. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.
In particolare, l?invenzione rende disponibile un impianto per il trattamento dei gas di scarico prodotti da una combustione, comprendente un condotto di convogliamento per i gas di scarico in cui sfocia una linea di alimentazione di un additivo atto ad operare la riduzione degli ossidi di azoto contenuti nei gas di scarico stessi, ed almeno un elemento filtrante per filtrare detto additivo, il quale ? realizzato in materiale polimerico. In particular, the invention makes available a plant for the treatment of the exhaust gases produced by combustion, comprising a conveyance duct for the exhaust gases into which a supply line for an additive leads to reduce the oxides of nitrogen contained in the exhaust gases themselves, and at least one filter element to filter said additive, which? made of polymeric material.
Il materiale polimerico possiede una perfetta compatibilit? con l?additivo di acqua ed urea che si utilizza normalmente nel processo SCR, e non risente in modo significativo della sua corrosivit?, rendendo perci? l?elemento filtrante molto pi? resistente e stabile rispetto a quelli che vengono attualmente usati in questo tipo di applicazione. Does the polymeric material have perfect compatibility? with the additive of water and urea that is normally used in the SCR process, and is not significantly affected by its corrosivity, making it therefore? the filter element much more? resistant and stable compared to those currently used in this type of application.
Preferibilmente, il setto filtrante ? realizzato in polipropilene, che tra i polimeri disponibili ? uno di quelli che possiede in modo pi? spiccato le sopraccitate caratteristiche di compatibilit? con l?additivo. Preferably, the filter media? made of polypropylene, which of the polymers available? one of those who owns more? marked the aforementioned characteristics of compatibility? with the additive.
Secondo un preferito aspetto dell?invenzione, l?elemento filtrante ? un setto di profondit?, che oltre a garantire un?elevata efficienza filtrante, possiede anche una grande capacit? di accumulo che assicura al filtro una vita utile pi? lunga. According to a preferred aspect of the invention, the filter element? a depth septum, which in addition to ensuring a high filtering efficiency, also has a large capacity accumulation that ensures the filter a longer useful life? long.
In alternativa, l?elemento filtrante pu? essere un setto di superficie plissettato, eventualmente configurato secondo una geometria stellare. Alternatively, the filter element can? be a pleated surface septum, possibly configured according to a stellar geometry.
L?elemento filtrante pu? essere realizzato con fibre polimeriche tramite un procedimento di meltblown. The filter element can be made with polymeric fibers through a meltblown process.
Ulteriori caratteristiche e vantaggi dell?invenzione risulteranno evidenti dalla lettura della descrizione seguente fornita a titolo esemplificativo e non limitativo, con l?ausilio delle figure illustrate nelle tavole allegate. Further characteristics and advantages of the invention will become evident from reading the following description provided by way of non-limiting example, with the aid of the figures illustrated in the attached tables.
La figura 1 ? lo schema di un impianto per il trattamento dei gas di scarico di un motore a combustione interna di un veicolo, secondo la presente invenzione. Figure 1? the diagram of a plant for the treatment of the exhaust gases of an internal combustion engine of a vehicle, according to the present invention.
La figura 2 ? il filtro per l?additivo che ? installato nell?impianto di figura 1, sezionato secondo un piano verticale. Figure 2? the filter for the additive that? installed in the system of figure 1, sectioned according to a vertical plane.
In figura 1 ? illustrato lo schema di un impianto 1 per il trattamento dei gas di scarico prodotti da un motore a combustione interna 2, tipicamente ma non esclusivamente un motore Diesel, che ? montato a bordo di un veicolo, come un?automobile, un autocarro, un autobus o simili. In figure 1? illustrated the diagram of a plant 1 for the treatment of the exhaust gases produced by an internal combustion engine 2, typically but not exclusively a Diesel engine, which? mounted in a vehicle, such as a car, truck, bus or similar.
L?impianto 1 ? predisposto per sottoporre i gas di scarico ad un processo di Riduzione Selettiva Catalitica (SRC), durante il quale gli ossidi di azoto (NOx) contenuti nei gas di scarico subiscono una reazione chimica di riduzione, dando origine ad azoto molecolare ed acqua. Plant 1? designed to subject the exhaust gases to a Selective Catalytic Reduction (SRC) process, during which the nitrogen oxides (NOx) contained in the exhaust gas undergo a chemical reduction reaction, giving rise to molecular nitrogen and water.
L?impianto 1 comprende un condotto di convogliamento 3 per i gas di scarico, nella fattispecie un tubo di scappamento che collega il collettore di scarico del motore 2 con la marmitta, ed una linea di alimentazione 4 per un additivo atto ad operare la riduzione degli ossidi di azoto contenuti nei gas di scarico. The system 1 comprises a conveyance duct 3 for the exhaust gases, in this case an exhaust pipe that connects the exhaust manifold of the engine 2 with the muffler, and a supply line 4 for an additive suitable for reducing the nitrogen oxides contained in the exhaust gases.
Detto additivo ? un agente riducente, generalmente sotto forma di un liquido azotato che ? composto all?incirca per il 32,5% da urea e per il resto da acqua deionizzata, e che ? conosciuto con il nome di AdBlue. Said additive? a reducing agent, generally in the form of a nitrogenous liquid which? composed of approximately 32.5% of urea and the rest of deionized water, and what? known as AdBlue.
La linea di alimentazione 4 comprende un serbatoio 40, ed una pompa 41 atta ad aspirare l?additivo contenuto nel serbatoio 40 per alimentarlo ad una valvola dosatrice 42, la quale ? atta ad iniettare quantit? dosate di detto additivo direttamente nel condotto di convogliamento 3 dei gas di scarico. The supply line 4 comprises a tank 40, and a pump 41 adapted to suck the additive contained in the tank 40 to feed it to a metering valve 42, which? suitable for injecting quantity? metered of said additive directly into the duct 3 for conveying the exhaust gases.
In particolare, la valvola dosatrice 42 ? atta ad iniettare l?additivo nel flusso di gas di scarico a monte di un catalizzatore 30, incorporato nella marmitta, in cui sono presenti apposite sostanze catalizzanti atte ad accelerare la riduzione degli ossidi di azoto. In particular, the metering valve 42? adapted to inject the additive into the exhaust gas flow upstream of a catalyst 30, incorporated in the muffler, in which there are suitable catalysing substances suitable for accelerating the reduction of nitrogen oxides.
Dopo l?avviamento del motore 2, il flusso dei gas di scarico scalda rapidamente il catalizzatore 30, sino a raggiungere le temperature relativamente elevate (oltre 250?C) che sono necessarie per innescare la reazione di riduzione degli ossidi di azoto. In queste condizioni, quando l?additivo liquido entra nel tubo di scappamento 3, l?urea in esso contenuta in soluzione si decompone in ammoniaca ed anidride carbonica. Grazie alle temperature elevate ed alla presenza del catalizzatore 30, l?ammoniaca opera la riduzione degli NOx dando origine ad azoto molecolare ed acqua, che infine vengono scaricati in atmosfera attraverso la marmitta. After starting the engine 2, the flow of exhaust gases rapidly heats the catalyst 30, until it reaches the relatively high temperatures (over 250 ° C) which are necessary to trigger the nitrogen oxide reduction reaction. Under these conditions, when the liquid additive enters the exhaust pipe 3, the urea contained in it in solution decomposes into ammonia and carbon dioxide. Thanks to the high temperatures and the presence of the catalyst 30, the ammonia operates the reduction of NOx giving rise to molecular nitrogen and water, which are finally discharged into the atmosphere through the muffler.
Affinch? la reazione di riduzione avvenga correttamente, l?additivo deve essere iniettato in quantit? calibrate in base alla temperatura dei gas di scarico, ed alla percentuale di NOx in essi contenuta. Questa calibrazione ? effettuata automaticamente da una centralina elettronica 9, che controlla il funzionamento della pompa 41 e della valvola dosatrice 42, in risposta ai segnali che le pervengono da un sensore di temperatura 90 e da un sensore dei gas di scarico 91, che sono inseriti nel tubo di scappamento 3 preferibilmente a valle del catalizzatore 30. So that? the reduction reaction occurs correctly, the additive must be injected in quantity? calibrated on the basis of the temperature of the exhaust gases and the percentage of NOx contained in them. This calibration? carried out automatically by an electronic control unit 9, which controls the operation of the pump 41 and the metering valve 42, in response to the signals received by it from a temperature sensor 90 and an exhaust gas sensor 91, which are inserted in the discharge pipe escapement 3 preferably downstream of the catalyst 30.
La linea di alimentazione 4 comprende inoltre un filtro 5 per filtrare l?additivo, il quale ? preferibilmente interposto tra il serbatoio 40 e la pompa 41. The supply line 4 further comprises a filter 5 for filtering the additive, which? preferably interposed between the tank 40 and the pump 41.
Come illustrato in figura 2, il filtro 5 comprende un involucro esterno 50, preferibilmente realizzato in materiale polimerico, il cui volume interno ? diviso da una cartuccia 6 in due distinte camere, di cui una prima camera 7 comunicante con un condotto d?ingresso 51 per l?additivo da filtrare, ed una seconda camera 8 comunicante con un condotto d?uscita 52 per l?additivo filtrato. As illustrated in Figure 2, the filter 5 comprises an outer casing 50, preferably made of polymeric material, the internal volume of which? divided by a cartridge 6 into two distinct chambers, of which a first chamber 7 communicating with an inlet duct 51 for the additive to be filtered, and a second chamber 8 communicating with an outlet duct 52 for the filtered additive.
Pi? in particolare, l?involucro esterno 50 comprende un contenitore inferiore 53 a forma di bicchiere cilindrico, la cui imboccatura ? chiusa ermeticamente da un coperchio superiore apribile 54, al quale sono fissati sia il condotto d?ingresso 51 sia il condotto d?uscita 52, collocati rispettivamente in posizione centrale e periferica. La cartuccia 6 comprende una gabbia centrale cilindrica 60 interposta tra due piattelli coassiali di supporto, di cui un piattello inferiore 61 completamente chiuso, ed un piattello superiore 62 provvisto di un cannotto centrale cavo 63, che si infila in modo amovibile su una porzione interna del condotto d?ingresso 51, tramite l?interposizione di una guarnizione anulare 64 di tenuta. Pi? in particular, the outer casing 50 comprises a lower container 53 in the shape of a cylindrical cup, the mouth of which? hermetically closed by an openable upper cover 54, to which both the inlet duct 51 and the outlet duct 52 are fixed, located respectively in a central and peripheral position. The cartridge 6 comprises a cylindrical central cage 60 interposed between two coaxial support plates, of which a lower plate 61 completely closed, and an upper plate 62 provided with a central hollow tube 63, which slides in a removable way on an internal portion of the inlet duct 51, through the interposition of an annular sealing gasket 64.
La gabbia centrale 60 ed i piattelli di supporto 61,62 sono tutti realizzati in materiale polimerico, preferibilmente dello stesso tipo di quello utilizzato per l?involucro esterno 50. The central cage 60 and the support plates 61,62 are all made of polymeric material, preferably of the same type as that used for the outer casing 50.
Sulla gabbia centrale 60 della cartuccia 6 ? coassialmente infilato un elemento filtrante 65 di forma sostanzialmente cilindrica, il quale ? trattenuto tra i piattelli di supporto 61 e 62, ed ? atto ad essere attraversato dal flusso di additivo che passa dalla prima camera 7 alla seconda camera 8, in modo da trattenere le impurit? in esso contenute. On the center cage 60 of the cartridge 6? coaxially inserted a filter element 65 of substantially cylindrical shape, which? retained between the support plates 61 and 62, and d? able to be crossed by the flow of additive which passes from the first chamber 7 to the second chamber 8, in order to retain the impurities. contained therein.
L?elemento filtrante 65 ? realizzato con un materiale polimerico, preferibilmente polipropilene, che possiede un?ottima compatibilit? con l?additivo da filtrare, ossia non viene corroso, n? subisce danni o eccessivi rammollimenti, quando viene attraversato e bagnato da detto additivo. The filter element 65? made with a polymeric material, preferably polypropylene, which has an excellent compatibility? with the additive to be filtered, that is, it is not corroded, n? it undergoes damage or excessive softening when it is crossed and wetted by said additive.
In questo modo, l?elemento filtrante 65 manifesta una vita utile molto pi? lunga degli elementi filtranti notoriamente utilizzati in questo tipo di applicazioni, rispetto ai quali possiede anche una maggiore efficacia e stabilit? nel tempo. In this way, the filter element 65 exhibits a much longer useful life. long of the filter elements known to be used in this type of applications, with respect to which it also possesses greater efficacy and stability? in time.
Secondo un preferito aspetto dell?invenzione, l?elemento filtrante 65 ? realizzato con lo stesso materiale polimerico con cui sono realizzati l?involucro esterno 50, nonch? eventualmente la gabbia centrale 60 ed i piattelli di supporto 61 e 62. According to a preferred aspect of the invention, the filter element 65? made with the same polymeric material with which the outer casing 50 is made, as well as? possibly the central cage 60 and the support plates 61 and 62.
In questo modo, nonostante la fabbricazione dell?elemento filtrante 65 e degli altri componenti dell?involucro 50 e della cartuccia 6 richiedano procedimenti tra loro differenti, ? vantaggiosamente possibile sia ridurre i costi di approvvigionamento delle materie prime, sia i costi di smaltimento del filtro 5, giacch? quest?ultimo pu? essere interamente smaltito con le sole modalit? previste per i materiali polimerici, senza richiedere operazioni di smontaggio n? di differenziazione dei rifiuti. In this way, although the manufacturing of the filter element 65 and of the other components of the casing 50 and of the cartridge 6 require different processes,? advantageously it is possible to reduce both the costs of procurement of raw materials and the costs of disposal of the filter 5, since? the latter can be entirely disposed of with the only methods? provided for polymeric materials, without requiring disassembly operations n? of waste separation.
In particolare, l?elemento filtrante 65 pu? essere realizzato da un tessuto-non-tessuto di fibre polimeriche, ottenute ad esempio con un procedimento di meltblown. In particular, the filter element 65 can? be made from a non-woven fabric of polymeric fibers, obtained for example with a meltblown process.
Nell?esempio illustrato, l?elemento filtrante 65 ? un setto di profondit? che, oltre a garantire un?elevata efficienza filtrante, consente un grande accumulo di impurit? prima di raggiungere la saturazione, e che quindi permette di aumentare significativamente la vita utile del filtro 5. In the example shown, the filter element 65? a septum of depth? which, in addition to ensuring a? high filtering efficiency, allows a large accumulation of impurities? before reaching saturation, and which therefore allows to significantly increase the useful life of the filter 5.
L?invenzione non esclude tuttavia che l?elemento filtrante 65 possa essere conformato come un pi? sottile setto di superficie plissettato, eventualmente avvolto intorno ad un asse centrale in modo da acquisire una geometria stellare. However, the invention does not exclude that the filter element 65 can be shaped as a pi? thin pleated surface septum, possibly wrapped around a central axis in order to acquire a stellar geometry.
Ovviamente, all?impianto 1 sopra descritto un tecnico del settore potr? apportare numerose modifiche di natura tecnico applicativa, senza per questo uscire dall?ambito dell?invenzione come sotto rivendicata. Obviously, at the plant 1 described above, a person skilled in the art will be able? make numerous modifications of a technical and applicative nature, without thereby departing from the scope of the invention as claimed below.
Claims (14)
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT000068A ITRE20080068A1 (en) | 2008-07-18 | 2008-07-18 | '' PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES '' |
| EP09797492A EP2300120A1 (en) | 2008-07-18 | 2009-07-14 | A plant for reducing the nitrogen oxides in exhaust gases |
| PCT/EP2009/058971 WO2010007053A1 (en) | 2008-07-18 | 2009-07-14 | A plant for reducing the nitrogen oxides in exhaust gases |
| JP2011517901A JP2011528412A (en) | 2008-07-18 | 2009-07-14 | Plant for reducing nitrogen oxides in exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT000068A ITRE20080068A1 (en) | 2008-07-18 | 2008-07-18 | '' PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES '' |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| ITRE20080068A1 true ITRE20080068A1 (en) | 2010-01-18 |
Family
ID=40750865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IT000068A ITRE20080068A1 (en) | 2008-07-18 | 2008-07-18 | '' PLANT FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES '' |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP2300120A1 (en) |
| JP (1) | JP2011528412A (en) |
| IT (1) | ITRE20080068A1 (en) |
| WO (1) | WO2010007053A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1402892B1 (en) * | 2010-11-23 | 2013-09-27 | Gvs Spa | REFINED FILTERING DEVICE FOR UREA |
| DE102011003585A1 (en) * | 2011-02-03 | 2012-08-09 | Mahle International Gmbh | Urea filter material |
| CN102935331A (en) * | 2011-08-15 | 2013-02-20 | 上海索菲玛汽车滤清器有限公司 | Apparatus for reducing nitrogen oxides in exhaust gas |
| JP2016098698A (en) * | 2014-11-20 | 2016-05-30 | 株式会社デンソー | Exhaust emission control system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999010080A1 (en) * | 1997-08-25 | 1999-03-04 | Hydac Filtertechnik Gmbh | Filter element with plastic filter casing |
| DE102007000538A1 (en) * | 2006-10-20 | 2008-05-08 | Denso Corp., Kariya | Exhaust gas cleaning device for internal combustion engine, has reverse suction controller device which propels pump in reducing agent reverse suction mode and varies reducing agent pumping mode |
| DE102007047885A1 (en) * | 2006-11-29 | 2008-06-05 | Denso Corp., Kariya | Reductive pressure feed pump for use in reducing agent utility system, has drive section producing drive power for driving mechanical section to discharge pressure to reducing agent, which flows through flow path over drive section |
-
2008
- 2008-07-18 IT IT000068A patent/ITRE20080068A1/en unknown
-
2009
- 2009-07-14 EP EP09797492A patent/EP2300120A1/en not_active Withdrawn
- 2009-07-14 WO PCT/EP2009/058971 patent/WO2010007053A1/en active Application Filing
- 2009-07-14 JP JP2011517901A patent/JP2011528412A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999010080A1 (en) * | 1997-08-25 | 1999-03-04 | Hydac Filtertechnik Gmbh | Filter element with plastic filter casing |
| DE102007000538A1 (en) * | 2006-10-20 | 2008-05-08 | Denso Corp., Kariya | Exhaust gas cleaning device for internal combustion engine, has reverse suction controller device which propels pump in reducing agent reverse suction mode and varies reducing agent pumping mode |
| DE102007047885A1 (en) * | 2006-11-29 | 2008-06-05 | Denso Corp., Kariya | Reductive pressure feed pump for use in reducing agent utility system, has drive section producing drive power for driving mechanical section to discharge pressure to reducing agent, which flows through flow path over drive section |
Also Published As
| Publication number | Publication date |
|---|---|
| EP2300120A1 (en) | 2011-03-30 |
| JP2011528412A (en) | 2011-11-17 |
| WO2010007053A1 (en) | 2010-01-21 |
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