US 3781171 A
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United States Patent 1 Maccaferri Dec. 25, 1973  ADDITIVE COMPOSITION FOR THE 2,031,917 2/1936 Winning et al. 44/59 COMBUSTION AIR 1 INTERNAL 2,289,040 7/1942 Ringer 44/l R COMBUSTION ENGINES FOREIGN PATENTS OR APPLICATIONS  Inventor: Gino Maccaferri, Via Castiglione 6,514,289 5/1967 Netherlands 44/4 26, Bologna, Italy  Filed; Sept 24, 1971 Primary Examiner-C, F. Dees  A l N 183 677 Att0rneyGuido Modiano et al.
57 ABSTRACT  US. Cl. 44/1 R, 44/15 1 51 Int. Cl. C101 5/10, c101 5/40 addmve the cmbustln m  Field of Search 44 1 R, 4, 15 R, temal comprising fmm 80 44/59, 51 52 72 percent by weIght of an Inert support, from 5 to 10 percent by weight of diphenyl, from 5 to 10 percent  References Cited by weight of hexamethylenetetramine, and from 5 to 40 percent by weight of a binding agent chosen from 13 758 Z R I I PATENTS 44/l5 R either camphor or paradichlorobenzene.
ei y 1,936,881 11/1933 Rose et al. 44/1 R 4 Claims, No Drawings ADDITIVE COMPOSITION FOR THE COMBUSTION AIR IN INTERNAL COMBUSTION ENGINES BACKGROUND OF THE INVENTION The present invention relatesto an additive composition for the combustion air in internal combustion engines, and more precisely engines of the controlled ignition type, using fuel of the petrol class.
Not all, petrols or gasolines mixed with air can be brought to high pressure without abnormal combustion taking place known as knocking. The serious damage which knocking can cause to engines is well known. There are petrols which in themselves have a high resistance to knocking, or in other words have a high octane number. On the other hand it is well known that this resistance to knocking can be improved by adding to the petrol suitable so-called antiknock substances. One of the antiknock substances most commonly used is tetraethyl lead, which however suffers from the serious disadvantages of being very toxic and of forming lead deposits in the engine.
SUMMARY OF THE INVENTION An object of the present invention is to provide a composition which when added to the air-petrol mixture effectively checks the negative phenomenon of knocking to a point which permits the use of petrol of low octane number without negatively influencing the efficiency of the engine.
Another objectof this invention is to provide a composition which, in addition to considerably widening the range of petrols usable in internal combustion engines, said range including as stated petrols of low octane number, is able substantially to overcome the serious disadvantages of presently used antiknock substances of the tetraethyl lead class, i.e., a composition which guarantees the absence of formation of deposits or crusts in the explosion chamber of the engine and which does not leave polluting residues.
Another object of this invention is to provide a composition which in the explosion chamber of an internal combustion engine allows substantially complete combustion of the air-petrol mixture, consequently leading to an advantageous and desired lowering of the level of carbon monoxide in the exhaust gases.
According to the invention there is provided a composition comprising from 4.0 to 80 percent by weight of an inert support, from 5 to percent by weight of diphenyl, from 5 to IOpercent by weight of hexamethylenetetramine, and from 5 to 40 percent by weight of a binding agent chosen from either camphor or paradichlorobenzene.
Advantageously, in the practical carrying out of this invention, the preferred inert support consists of naphtalene.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be more evident from the following description of some examples of compositions and the preparation of said compositions.
EXAMPLE 1 Cold preparation Forty grams of napthalene in commercially available powder form previously purified of all impurities, 5
grams of diphenyl, and 5 grams of hexamethylenetetramine were introduced into a powder mixer. Thorough mixing was carried out until a uniform powdery mass was obtained, and towards the end of mixing 5 grams of synthetic camphor were added as a binding agent. The mixture thus obtained was subjected to a tablet forming process with pressing to the extent of 30 tons. The tablets thus obtained were left for about one hour for drying.
In using the tablets thus obtained, one is placed in a suitable container preferably arranged downstream of the air filter and upstream of the carburettor in an internal combustion engine. The air drawn in for burning the petrol of low octane number passes through said container. The air coming into contact with the tablet is at a temperature such that it takes up the easily volatile products from said tablet. These volatile products then pass into the air-petrol mixture which forms in the carburettor and successively enter the explosion chamber, and it was found in rigorously controlled tests that the presence in said mixture of quantities of diphenyl and hexamethylenetetramine effectly checked the phenomenon of knocking, this latter phenomenon to be exnected because petrol of low octane number was used. Deposits and incrustations in the engine were found to be absent, and because of the lower level of carbon monoxide in the exhaust gases with respect to that which would have been expected using said petrols of low octane number, more complete combustion of the air-petrol mixture was determined to have taken place.
' EXAMPLE n A composition according to the invention was prepared under cold conditions as described in Example I, with the exception that traces of acenaphthene were added to the inert naphtalene support in order to give a higher calorific value to the composition. Synthetic camphor was again used as the binding substance in the same quantity as heretofore stated, and in a like manner tablet formation was carried out using pressing to the order of 30 tons.
By using these tablets in an internal combustion engine, in a position downstream of the air filter and upstream of the carburettor, improved results were obtained.
EXAMPLE III A composition was prepared as described in example I, with the exception that in order to give a certain calorific value to-the inert naphtalene support, and hence improve the desired results, the naphtalene was pre- I. The tablets obtained by pressing gave results when used in an internal combustion engine which were surprising and improved with respect to those of Example 1.
EXAMPLE IV Hot preparation Forty kg. of naphtalene (inert support) previously purified of any impurity were initially introduced into an autoclave of the oscillating type. The temperature was raised to about 120 C causing the previously loaded naphtalene firstly to melt and then to boil, and this temperature was maintained for about 40 minutes. The temperature was successively lowered to 60-65 C and 40 kg. of a binding substance consisting of paradichlorobenzene were added to the autoclave. The temperature was then raised to about 100 C maintaining boiling for about minutes. Successively the contents of the autoclave were cooled to a temperature of 60-65 C and then 10 Kg. of diphenyl were added. Keeping the autoclave under agitation, the temperature was again raised to 100 C, maintaining it for 10 minutes. After successively cooling to 60 C 10 Kg. of hexamethylenetetramine were added. The temperature was again raised to 100 C and maintained for 10 minutes. At the end of this period the temperature was lowered to a value of 5055 C and 0.2 Kg. of safranine were added as a dye. Agitation of the autoclave was continued at this temperature and mixing was continued until a uniform mass was obtained. Successively the treated mass was cast into moulds and the blocks obtained were left to cool naturally. When solidified said blocks were thoroughly crushed and formed into tablets by pressing to about 60 tons. in this case tablets were also obtained which when used in an internal combustion engine allowed the objects of this invention to be attained, i.e., an effective annulling of that phenomenon of knocking which would have been expected using petrol of low octane number, the absence of deposits or incrustations in the engine and a lower level of carbon monoxide in the exhaust gases.
On using the tablets of the composition according to the invention it was found that about 30 grams of said composition were consumed for each 200 Km. of travel of the motor vehicle.
It was also found that the presence of a tablet downstream of the air filter and in the path of the air drawn in improved the filtering of said air, so diminishing the possibility of formation of deposits, incrustations and the like.
The invention so conceived is susceptible to modifications falling within the scope of the inventive idea as defined in the accompanying claims.
1. An additive composition for the combustion air in internal combustion engines, comprising from 40 to percent by weight of an inert support consisting of naphtalene from 5 to 10 percent by weight of diphenyl, from 5 to l0 percent by weight of hexamethylenetetramine and from 5 to 40 percent by weight of a binding agent selected from the group consisting of camphor and paradichlorobenzene.
2. A composition as claimed in claim 1, wherein said naphtalene is pretreated with butane.
3. A composition as claimed in claim 1, comprising, by weight, percent of naphtalene, 5 percent of diphenyl, 5 percent of camphor, and 5 percent of hexamethylenetetramine, said naphtalene being pretreated with butane gas.
4. A composition as claimed in claim 1, comprising, by weight, 40 percent of naphtalene, 10 percent of diphenyl, 40 percent of paradichlorobenzene, 10 percent of hexamethylenetetramine and safranine dye.