Title of Invention

"A METHOD AND DEVICE FOR IMPROVING THE COMBUSTION OF FUELS IN APPARATUSES"

Abstract

The invention concerns a method for improving fuel combustion in appliances wherein a fuel/oxidant mixture is burnt to supply energy whereby a solid organism is sublimed in an oxidant gas stream previous to being mixed with a fuel, die resulting mixture being then burnt to supply energy. The invention is characterised in mat die sublimed volume proportion of said organic compound relative to the oxidant gas volume fonning part of the mixture, ranges between 0.5 and 15 ppm. The invention is useful for improving combustion in an internal combustion engine, in particular of a motor vehicle, or in an industrial burner.

Full Text

The present invention relates to a method and device for improving the combustion of fuels in apparatuses. The present invention relates to a method and to a device for improving the combustion of fuels in apparatuses in which a mixture of a fuel and an oxidizer is burnt in order to provide energy. Document WO 98/01662 in the name of the Applicants describes a method and a* device of this type. More specifically, in that prior document, the oxidizer gas inlet of the apparatus is provided with means intended to hold therein naphthalene in solid form so that the oxidizer gas becomes charged with naphthalene by direct transformation of the latter from its solid phase into a gas phase, which process will be called "sublimation" in the present description. In a preferred version of the device described in the aforementioned document, the means for holding the naphthalene in the stream of gaseous oxidizer are formed by a cartridge placed in a filter located in the line for feeding the oxidizer gas into the apparatus. For example, if the apparatus is an internal combustion engine or a burner fed with an oxidizer formed from hydrocarbons, the means for holding the naphthalene are placed in the air filter of the apparatus in question. Moreover, the aforementioned document specifies that the amount of naphthalene is chosen to have a value which does not exceed 5 mg per liter of oxidizer gas sent into the apparatus. However, by means of many tests carried out by the Applicants it has turned out that the proportion of naphthlene indicated does not lead to the desired effect of improving combustion. The object of the present invention is to propose a method and a device for improving combustion, these being improved over those described in the prior art which have just been briefly summarized above, and especially to indicate the effective volume proportions of sublimable compound with respect to the volume of oxidizer gas to be used. The subject of the invention is therefore a method for improving the combustion of fuels in apparatuses in which a mixture of a fuel and an oxidizer is burnt in order to provide energy via which a solid organic compound is sublimed in a stream of oxidizer gas prior to it being mixed with a fuel, the resulting mixture then being burnt in order to provide energy, characterized in that the sublimed volume proportion of said organic compound with respect to the volume of oxidizer gas forming part of said mixture lies within a range going from 0.5 ppm to 15 ppm. According to the invention, the volume proportion of the sublimable organic compound may therefore be several orders of magnitude smaller than the proportion indicated in the prior art. Moreover, the tests have shown that there is no combustion improvement effect outside the range of values indicated. As a result, in fact, the amount of sublimable organic compound consumed by the method according to the invention is very markedly less than the consumption estimated previously. According to other characteristics of the method of the invention: • if it is carried out in an internal combustion engine, said range is from 0.5 ppm to 2.5 ppm, preferably from 1.2 ppm to 1.5 ppm; - if it is carried out in an industrial burner, said range is from 5 ppm to 15 ppm; - the tests performed by the Applicants have also shown that naphthalene is not the only sublimable substance which is suitable for carrying out the invention. Consequently, according to other characteristics of the method of the invention: - said organic compound is chosen from polycyclic aromatic compounds, polycyclic alicyclic compounds, functionalized aromatic compounds, functionalized alicyclic compounds, aromatic or aliphatic acids and/or mixtures of these compounds; - said sublimable compound is chosen from the group of compounds consisting of naphthalene, anthracene, cubane, adamantane, camphane, naphthols, anthraquinone, camphor or mixtures of these compounds; - said sublimable compound is naphthalene, adamantane and/or camphane; - the sublimable compound or compounds is/are used in the form of pills obtained by compacting their powders; - said pills comprise only a single compound chosen from said group of compounds; - said pills comprise at least two compounds chosen from said group of compounds. The subject of the invention is also an oxidizer filter for implementing the method as defined above, comprising a casing having an oxidizer gas inlet and an oxidizer gas outlet and, interposed between this inlet and this outlet, a filtering element, the filter also comprising a cartridge located downstream of said filtering element with respect to the stream of oxidizer gas passing through it, said cartridge comprising perforated tubes in which the sublimable organic compound is placed, said filter being characterized in that said cartridge comprises at least one support member in the form of a band having corrugations gripping said tubes, preferably with an elastic effect. By virtue of this particular characteristic of the filter according to the invention, the structure of the banded cartridge causes a minimum pressure drop with respect to the stream of oxidizer passing through the filter. According to other characteristics of this filter according to the invention: - when said filtering element has a cylindrical and annular overall shape, said support member in the form of a band is elastic and shaped as a C whose arms are pushed outward and in that this support member is held in said filtering element by said band being applied against its inner wall; - each arm of said band is extended toward the inside of the C by a corrugated portion to which a strip, also corrugated, is fastened so as to provide, with said band, passages for fastening said tubes; - when said filtering element has mainly a flat shape, said support member in the form of a band comprises two corrugated strips fastened to each other so as to define passages for said tubes, said cartridge being placed directly against said filtering element, preferably by resting on the latter by gravity; - each tube has no perforations over part of its length so as to contain a reserve of sublimable organic compound; - said pills may be stacked in said tubes and pressed by a spring placed at one of the ends of the stack of pills; - said support member in the form of a band has omega-shaped corrugations in which said tubes are held by snap-fastening. The particular characteristics of the filter that have just been defined especially provide the following advantages: - the fastening of the tubes containing the sublimable organic compound by corrugated bands allows the tubes to be mounted in the cartridge easily; - the amount of compound placed in the filter may be easily varied by choosing the number of tubes fastened in the corrugated bands. This represents an advantageous convenience for the user, even for a non-expert, since he himself will be able not only to replace the used filters but also, without any difficulty, to fit the cartridge into the apparatus with which the filter is associated. For example, if the filter is mounted in an automobile engine, it may thus be easily tailored to the cubic capacity of the engine, in particular if the cartridge is sold in the retail trade. Moreover, tailoring to the shape of the filter may be done without any problem by suitably placing the tubes with respect to the filter inlet and outlet. - The structure of the cartridge is such that the tubes are disengaged from the filtering element and, with regard to the cylindrical configuration envisioned, it places the tubes at the center of the oxidizer flow. Other characteristics and advantages of the invention will appear in the course of the description which follows, given solely by way of example and with reference to the appended drawings in which: - Figure 1 shows, in axial sectional view, an oxidizer filter used upstream of the inlet manifold of an internal combustion engine, the filter being provided with a charge of sublimable organic compound; - Figure 2 is a radial sectional view of the filter in Figure 1, on the line of section il-ll; - Figure 4 is a vertical sectional view of a fiat filter that can be used as the filter in Figure 1 and also charged with a sublimable organic compound; - Figure 5 is a plan view of the filter in Figure 4, its cover having been removed; - Figures 6 and 7 show two alternative embodiments allowing tubes filled with a sublimable organic compound to be fastened in a filter according to Figures 1 to 3 or 4 and 5. Figures 1 to 3 show a first embodiment of a filter for implementing the method according to the invention. This is an oxidizer filter 1 for an internal combustion engine, comprising a casing 2 closed by a cover 3, both being of cylindrical overall shape. The casing 1 has a side inlet orifice 4 intended to be connected to an oxidizer intake (not shown), for example an air intake. It also has an axial outlet orifice 5 intended to be connected to the inlet manifold (also not shown) of an internal combustion engine. An annular filtering element 6 of conventional shape and construction is placed axially in the filter, it being held in place by any suitable means. The filter 1 also contains a cartridge 7 containing a sublimable organic substance. This cartridge 7 comprises two supports 8a and 8b placed inside the filtering element 6 at a certain distance apart along the axis of the filter. Each of these supports comprises an elastic band 9 bent into the form of a C, the elasticity of which is such that the ends of the C have a tendency to move further apart. Consequently, in order to place such a support inside the filtering element 6, its ends need to be moved closer together for introducing the support into it, and then the ends need to be released so that the arms of the C press with an elastic stress against the filtering element 6. This results in very convenient mounting/removal of the cartridge 7, requiring no tool. This arrangement is particularly suitable for making convenient the replacement of a used cartridge with a full cartridge. Beyond the ends of the C-shaped part of the band 9, the latter is bent back inward and shaped, so as to have corrugated parts 10a, 10b and 10c, the peaks of which are oriented laterally outward. Each of these corrugated parts is duplicated by a corrugated part (11a, 11b and 11c respectively) of a second band 11, two of these bands being provided in the example described. The associated corrugated parts 10a, 11a, 10b, 11b and 10c, 11c define a passage 12 for a reservoir tube 13 intended to contain the sublimable compound. Each of these tubes is formed from a rolled portion of sheetmetal, the longitudinal edges of which are not contiguous, thus defining a longitudinal slit 14 (Figure 3). The rolled sheetmetal is closed at each end by a plug 15, preferably in a tamperproof manner. Moreover, it is perforated in order to form rows of holes 16 lying along generatrices which are 90° apart one with respect to another and with respect to the slit 14, respectively. However, it will be noted that these rows of holes do not extend over the entire length of the tubes, the portion corresponding to a distance d of each tube not having holes being, in the example described, in that part of the filter located on the far side of the inlet 4 with respect to the outlet 5. The reason for this will be explained below. Preferably, the apparent surface area of the slit 14 is equal to the cumulative apparent surface area of one row of holes 16. Before being sealed, each tube 13 is filled with solid balls 17 of the sublimable organic substance, each ball having a diameter slightly less than the inside diameter of the tube. The balls 17 are stacked in the tube 13 and pressed against one another by a spring 18 provided inside the tube at one of the ends of the latter. The reason for having a portion of each tube with no holes may thus be understood. This is because the said portion may serve as a reservoir of balls, those being present in the reservoir not being broached by the sublimation until they have descended toward the perforated portion of the tube after partial or complete consumption of the balls housed in this perforated portion. In this regard, it should be noted that the stream of oxidizer in the filter is predominantly established in a region lying between the inlet 4 and the outlet 5 of the filter (in the example, the lower 3/4 region), the rest of the volume of the filter being coursed by a stream of oxidizer having a lower flow rate. The location of the section of each tube having no holes therefore preferably coincides with this remaining volume swept by a small stream of oxidizer. The cumulative total surface area of the holes 16 and of the slit 14 for all the tubes 13 defines the rate of sublimation of the sublimable compound when it is swept by the stream of oxidizer penetrating each tube and leaving therefrom charged with a certain proportion of sublimed compound. This total surface area is chosen in such a way that, especially when taking into account the flow rate of oxidizer gas passing through the filter, the proportion of sublimed compound in the stream of gas leaving the filter via the outlet orifice 5 is between 0.5 ppm and 2.5 ppm, it being possible to achieve maximum effectiveness if this surface area fixes the proportion between 1.2 and 1.5 ppm. In the case of naphthalene, 1 ppm by volume of sublimed substance corresponds to 5.71 mg of naphthalene per m3 of oxidizer gas, such as air. According to the method for improving combustion carried out by using the oxidizer filter that has just been described, the organic compounds must sublime between -15°C and +80°C and they may be chosen from polycyclic aromatic compounds, polycyclic alicyclic compounds, functionalized aromatic compounds, functionalized alicyclic compounds, aromatic or aliphatic acids and/or mixtures of these compounds. It has turned out that the following compounds are particularly suitable: naphthalene, anthracene, cubane, adamantane, camphane, naphthols, anthraquinone and camphor. It is also possible to use a mixture of two or more of these substances. However, at the present time, naphthalene, adamantane and camphane are preferred substances. It is also advantageous to produce the sublimable organic compound or compounds in the form of pills obtained by compacting a powder of the compound or compounds in question. The shape of the pills will be tailored to the support intended to hold them in the stream of oxidizer gas. Ball-shaped pills, as shown above, fit very well in an oxidizer filter as described above. However, other shapes are possible, such as rods, disks, etc. The filter described above with regard to Figures 1 to 3 was mounted in a diesel engine on a test rig, the engine having firstly undergone tests, with the filter not having the cartridge 7, and then the same tests were performed with this cartridge in place as shown in Figures 1 to 3. During the two series of tests, the following parameters were measured in succession, at full throttle, at idle and during transient operating phases of the engine, for three different sublimable organic compounds, namely naphthalene, adamantane and camphane, respectively: torque delivered by the engine; specific fuel consumption; CO content of the exhaust gases; content of unburnt hydrocarbons in the exhaust gases; opacity of the exhaust gases; NOx content of the exhaust gases. The values of these parameters were measured and the percentage variation between the values recorded during the first test series and the equivalent values in the second series was noted. Furthermore, the transient phases were examined by taking averages of the measured values during successive increments in speed from idle to 4000 rpm, with hold periods every 500 rpm for one hour. The results of this comparative study are given in the following table: TABLE (Table Removed) In this table, the hyphens mean that the corresponding value was not measured or was not measurable. Thus, it may be seen that the use according to the invention of the sublimable organic compound results in reduced fuel consumption and considerable improvement in the parameters determining the pollution by the exhaust gases of the engine. Figures 4 and 5 show another oxidizer gas filter 1A having a parallelepipedal shape. The casing 2A of this filter comprises a cover 3A, a side inlet 4A for oxidizer gas and an outlet 5A provided in the cover 3A. The cartridge 7A for the sublimable organic compound is shaped in a similar way to that described with regard to Figures 1 to 3, except the band 9A is not elastic and is developed in a plane resting by gravity on the filtering element 6A. The cartridge comprises tubes 13 similar to those already described, only three of these tubes being shown. However, it will be noted that they have holes along their entire length and do not have a spring. Moreover, in a space close to the inlet 4A, there are no tubes, so as to guarantee as uniform a sublimation of the compound as possible. Figure 6 shows an alternative version of fastening the tubes 13 in the filter. These are held elastically between two corrugated bands 19 suitably fastened to the wall of the filter. Figure 7 shows another fastening version in which the tubes 13 are clipped into omega-shaped housings 20 in a band 21, the latter being suitably fastened in the casing of the filter. Tests performed on industrial burners, especially those that can be used in central heating plants, have also demonstrated the effectiveness of the method according to the invention. It has been demonstrated that, compared with a burner not equipped with an oxidizer filter according to the invention, a burner so equipped can reduce its consumption by up to 22% and the sulfur emanations were eliminated, the NOx decreasing by 50% and the opacity also being reduced by 50%. A filter is not customary in the case of industrial burners. It is therefore possible to place a cartridge of sublimable organic substance directly in the oxidizer gas feed line. In this case, the proportion of sublimable organic compound preferably lies within a range going from 5 ppm to 15 ppm, depending on the type of burner fitted. WE CLAIM : 1. A method for improving the combustion of fuels in apparatuses in which a mixture of a fuel and an oxidizer is burnt in order to provide energy via which a solid organic compound is sublimed in a stream of oxidizer gas prior to it being mixed with a fuel, the resulting mixture then being burnt in order to provide energy, characterized in that the sublimed volume proportion of said organic compound with respect to the volume of oxidizer gas forming part of said mixture lies within a range going from 0.5 ppm to 15 ppm. 2. The method as claimed in claim 1 wherein, if it is carried out in an internal combustion engine, said range is from 0.5 ppm to 2.5 ppm, preferably from 1.2 ppm to 1.5 ppm. 8 The method as claimed in claim 1, wherein if it is carried out in an industrial burner, said range is from 5 ppm to 15 ppm. 4. The method as claimed in any one of claims 1 to 3, wherein said organic compound is chosen from polycyclic aromatic compounds, polycyclic alicyclic compounds, functionalized aromatic compounds, functionalized alicyclic compounds, aromatic or aliphatic acids and/or mixtures of these compounds. 5. The method as claimed in claim 4, wherein said sublimable compound is chosen from the group of compounds consisting of naphthalene, anthracene, cubane, adamantane, camphene, naphthols, anthraquinone, camphor or mixtures of these compounds. 6. The method as claimed in any one of claims 1 to 5, wherein the sublimable compound or compounds is/are used in the form of pills obtained by compacting their powders 7. The method as claimed in claim 6, wherein said pills comprise only a single compound chosen from said group of compounds. 8. The method as claimed in claim 6, wherein said pills comprise at least two compounds chosen from said group of compounds. 9. An oxidizer filter for implementing the method as claimed in any one of the preceding claims, comprising a casing having an oxidizer gas inlet (4) and an oxidizer gas outlet (5) and, interposed between this inlet and this outlet, a filtering element (6), the filter also comprising a cartridge (17) located downstream of said filtering element (6) with respect to the stream of oxidizer gas passing through it, said cartridge (7) comprising perforated tubes in which the sublimable organic compound is placed, wherein said cartridge comprises at least one support member in the form of a band (9) having corrugations gripping said tubes, preferably with an elastic effect. 10. The filter as claimed in claim 9 wherein said filtering element has a cylindrical and annular overall shape, wherein said support member in the form of a band is elastic and shaped as a C whose arms are pushed outward and in that this support member is held in said filtering element by said band being applied against its inner wall. 11. The filter as claimed in claim 10 wherein each arm of said band is extended toward the inside of the C shaped support member by a corrugated portion to which a strip, also corrugated, is fastened so as to provide, with said band, passages for fastening said tubes. 12. The filter as claimed in claim 9 wherein said filtering element has mainly a flat shape, wherein said support member in the form of a band comprises two corrugated strips fastened to each other so as to define passages for said tubes, said cartridge being placed directly against said filtering element, preferably by resting on the latter by gravity. 13. The filter as claimed in any one of claims 9 to 12, wherein each tube has no perforations over at least part of its length so as to contain a reserve of sublimable organic compound. 14. The filter as claimed in claim 12 for carrying out the method as claimed in any one of claims 6 to 8, wherein said pills are stacked in said tubes and pressed by a spring placed at one of the ends of the stack of pills. 15. The filter as claimed in either of claims 9 and 10, wherein said support member in the form of a band has omega shaped corrugations which said tubes are held by snap-fastening.

Documents:

abstract.jpg

in-pct-2000-00341-del-abstract.pdf

in-pct-2000-00341-del-claims.pdf

in-pct-2000-00341-del-correspondence-others.pdf

in-pct-2000-00341-del-correspondence-po.pdf

in-pct-2000-00341-del-description (complete).pdf

in-pct-2000-00341-del-drawings.pdf

in-pct-2000-00341-del-form-1.pdf

in-pct-2000-00341-del-form-13.pdf

in-pct-2000-00341-del-form-2.pdf

in-pct-2000-00341-del-form-3.pdf

in-pct-2000-00341-del-form-5.pdf

in-pct-2000-00341-del-gpa.pdf