EP1421156A1

EP1421156A1 - Filter medium for liquid fuels and filter device utilizing same

Info

Publication number: EP1421156A1
Application number: EP02766699A
Authority: EP
Inventors: Nikolai Ivanovich Butenko
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-27
Filing date: 2002-04-08
Publication date: 2004-05-26
Also published as: EP1421156A4; WO2002088278A1

Abstract

A filter medium for liquid fuels and a filter device comprise at least one porous layer of a titanium-base component and at least one layer of a copper-base component having a higher normal electrode potential compared with that of titanium. To make the filterdevice able to activate the fuel fed for combustion, electron conduction is rendered to all components of the filter medium and accordingly to parts of the active zone of the filter device, while the layers are spaced apart but for a portion of the surface thereof to provide a galvanic coupling, the layer of the copper-base component being likewise porous and having a mean pore size and total porosity in excess of those of the layer of the titanium-base component. When fit in the filter case the layer of the copper-base component is upstream from the other layers. 2 indep. claims and 12 dependent claims; 1 drawing figure; 2 tables; 6 examples.

Description

FILTER MEDIUM FOR LIQUID FUELS AND FILTER DEVICE UTILIZING SAME

Technical Field

The present invention relates: to the qualitative and quantitative composition and physical characteristics of porous composite filter medium based on titanium and copper (having optional additives, such as zinc, lead, nickel, and some other metals) and/or compounds and alloys thereof that are electron conductors, and to a filter device comprising such filter medium.

These filter media and filter devices are designed for physical and chemical activation of liquid fuels, preferably hydrocarbon fuels (as for their chemical composition), with simultaneous removal of mechanical impurities directly in the fuel conveying system of gasoline engines, diesels and other internal-combustion engines (ICE hereinafter) or heat power systems, such as steam boilers or hot-water boilers, industrial furnaces and the like.

Background Art

Said heat engines and heat power systems are not sources of energy only but also of toxic effluents, of which CO, CH, NO_x, carbon black, and compounds of heavy metals being the most hazardous. For this reason, further requirements are imposed upon filter media and filter devices parallel with the obvious requirement of adequately removing fine particles from liquid fuels, which is easy now to comply with. Among such requirements the most important is that the filter media and filter devices be suitable for physical and chemical activation of fuels with the purpose of: reducing concentration of toxic components in combustion gases discharged to the atmosphere, improving efficiency of ICE and other heat power systems with correspondingly decreasing specific fuel consumption, and decreasing specific consumption of liquid fuel in terms of an arbitrary unit (for example 100 km) of a vehicle run or a unit of heating capacity.

It is common knowledge that attempts to solve these problems were made in a variety of ways and were distinct both in concept and result.

Thus, costly high-octane gasoline is used to reduce discharge of heavy metals and primarily lead for such antiknock additive as tetraethyl-lead is banned in a number of countries. To reduce toxic CO, CH, carbon black and, to only a small extent, NO_x in exhaust gases, use is made of expensive and cumbersome catalytic reactors installed in exhaust pipes for burning CO, CH and carbon black up to CO₂ and H₂O, platinum and/or palladium being commonly used as catalysts. The catalytic reactors are responsible for a noticeably higher resistance to exhaust flow with associated decrease in ICE power and increase in specific fuel consumption.

Clearly, attempts are being made to improve the composition of burnt gases in the course of combustion rather than prior to their escape from the exhaust pipe.

A customary approach to this problem consists in introducing, into the fuel-air charge, dispersible additives capable of distributively augmenting combustion to thus even up temperature over all combustion space with an attendant reduction in NO_X; CO, CH and carbon black.

Attempts to solve the problem of combustion efficiency and harmful emissions by this means are, more often than not, apt to bring about undesirable results.

One example of such attempts is known from WO 96/40844 (PCT/US 96/09653) where additives are disclosed to comprise: at least one organic or inorganic compound selected from a vast group or a mixture of compounds having a latent heat of evaporation no less than 21 kJ/mol and speed of laminar Bunsen flame not smaller than 40 cm/s; and non-lead metal or element (including organic or inorganic derivative compounds thereof) selected from the group consisting of alkali and alkaline-earth metals, aluminum, boron, bromine, bismuth, beryllium, chromium, cobalt, copper, gallium, germanium, iodine, iron, indium, molybdenum, nickel, niobium, phosphorus, palladium, tin, zinc, rhenium, silicon, vanadium, scandium, yttrium, elements of the lanthanide and the actinide series, titanium, zirconium, hafnium, tantalum, tungsten, ruthenium, osmium, rhodium, iridium, gadolinium, platinum, silver, gold, cadmium, mercury, thulium, arsenic, antimony, selenium, tellurium, polonium, and mixtures thereof.

Even a cursory examination of the listing will suffice to put in doubt the likelihood of reducing harmful components in exhaust gases by addition of compounds containing radio- elements of the actinide series or highly toxic cadmium and arsenic. Conventional tetraethyl- lead compared with such additives now seems to be environmentally innocent as an antiknock compound. As to the additives, such as irretrievably used up platinum, gold, rare elements of the lanthanide series and even palladium or iridium, they are unlikely to be available for widespread use because of high costs.

Hence, a practicable listing of environmentally acceptable combustion improvers for liquid fuel burning in combustion chambers of ICE and in furnaces of other heat power systems made with utilization of metals is usually limited to elements known to form brass or bronze, such as copper, zinc, tin, and some others, i.e. manganese (Russian Patent No. 1,838,656). It is to be noted that these immediately available and minimum toxicity metals have been mentioned in the cited International publication as well.

Consequently, in the search for improved combustion control, aimed at reduced toxicity of exhaust gases and at incidental offset in wear on the internal combustion engines with a resulting reduction in specific fuel consumption, the actual problem is not one of finding metallic additives suitable for reasons of availability and environmental safety to be introduced into the flow of liquid fuel supplied for combustion but of providing the most effective means for incorporating such additives.

To this end filter-reactor combinations were suggested to deliver liquid fuel for combustion via thermal catalytic chambers (Russian Pat. Nos. 1,799,429; 1,801,175; and 1,801,176) or magnetic chambers (Russian Pat. No. 2,028,491), the chambers being filled with smooth-surface, i.e. small surface area, pellets of copper, tin, and other metals that go to work as donors of combustion controlling ions.

Although many metals, being heated in the presence of catalysts or exposed to a magnetic field of a certain strength, can be ionized and become slightly soluble in a fuel after interacting with traces of water and acids contained therein, complicated and cumbersome filter-reactor combinations are not very useful for all practical, specifically power-saving, purposes, especially when mounted on automobiles.

It is also doubtful that sufficient ions of copper, tin, and other ingredients of the selected bronze could have been introduced into gasoline in so short a residence time of the gasoline in the carburetor having bronzed walls of the air-mixing chamber (US Pat. No. 4,715,326), not to mention introduction of ions by this way into kerosene, diesel fuel or black oil, all of which are known to be mixed with air without resort to carburetors.

Preferred therefore are filter media and filter devices utilizing such filter media, which provide liquid fuel activation without outside power supply and control, and, what is more, allow introduction at will of ions of combustion-control metals into the fuel flow that interacts with extended surfaces of the filter.

A filter medium and filter device bearing closely on the invention are both disclosed in USSR Inventor's Certificate No. 1,586,747.

The prior art filter medium for liquid fuels comprises a porous layer of a titanium-base component with electron conduction, having through pore clear sizes ranging from 100 to 200 μ m, and specifically being disclosed as a sintered plate or cup, and a component having ionic conduction based on a metal with a higher normal electrode potential compared with that of titanium. The basic metal of the latter component is copper in the form of microlayers of a suitable salt thereof made by saturating a sintered titanium bar with a solution of such salt and by drying the saturated bar to a constant weight.

The prior art filter device for liquid fuels comprises a case having an inlet and an outlet, and a replaceable active part (insert) made of the disclosed layered filter medium disposed inside said case.

In actual practice of utilizing such filter media and filter devices, the liquid fuel would wash away a copper salt from the pores and into cylinders of ICE or combustion chambers (furnaces) of other heat power systems. The CvX ions, dispersed in the fuel, would catalyze combustion and would serve to even up the temperature field over the cylinder space or combustion chambers to result only in a slight decrease in CO and NO_x contents of exhaust gases and in formation of minor deposits of copper on the surfaces of the cylinder liners, which deposits were noticeable only when the used filters were replaced by fresh ones prior to the complete washing of the copper salt and when such filters had been used for long time enough (usually longer than 2 to 3 months).

The service life of the prior art filter media and filter devices as regards dirt capacity proves to be longer than that regarding ionogenic capacity which would be exhausted in hours should there be used fuels containing appreciably high amounts of water. Also, due to copper salt micro-layers that cover and smooth off the pore surfaces of the titanium-base component, the titanium, as an element extremely capable of combining into hydrides, is practically deprived of mechano-chemical action on the molecules of liquid fuel as it is pressure forced through the filter device to activate, under different conditions, the molecules prior to air-fuel mixture preparation. And lastly, the prior art filter medium and the filter device utilizing such filter medium are not able to offset wear on the surfaces of cylinder and piston assemblies of gasoline or diesel ICE in the sense that persistent use of such filter medium and filter device would result in too thin a copper deposit to offset the wear.

Disclosure of the Invention

Therefore, the problem underlying the invention consists: firstly, in the creation of a filter medium for liquid fuels, specifically automotive fuels, wherein the fuel activation for improving combustion with toxicity-reduced exhaust would be provided by way of refinement upon the filter composition and structure, as well as reduced wear on the surfaces of cylinder and piston assemblies or combustion chambers in ICE would be promoted in a simplest possible way, and secondly, in the creation of a filter device wherein a wide variety of liquid fuels as to chemical composition and viscosity would be activated by way of improved rearrangement of components at least part of which consists of said filter medium.

According to the first aspect of the invention the above-stated problem is resolved by providing a filter medium for liquid fuels, comprising at least one porous layer of a titanium- base component and at least one layer of a copper-base component having a higher normal electrode potential compared with that of titanium, wherein all the components are characterized with electron conduction, and the layers thereof are spaced apart but for a portion of the surface thereof to provide a galvanic coupling, the layer of the copper-base component being likewise porous and having a mean pore size and total porosity in excess of those of the layer of the titanium-base component.

Arrangement of the layers of the components in spaced relation but for a portion forming the galvanic coupling and utilization of the porous body of an initially non-oxidized copper- base material make it possible, parallel with the expected enhancement of dirt capacity, to obtain non-obvious effect of galvanic corrosion of copper in liquid fuels containing water of condensation equal to "routine repair" of parts of cylinder and piston assemblies in ICE (especially cylinder liners) resulting from micro-layer deposition of atoms of copper and/or other metals reduced in the process of fuel combustion. It was unexpectedly found that leaded gasoline enables formation of a leaded brass micro-layer to make exhaust gases virtually free from lead. Also a noticeable decrease in toxicity of exhaust was observed on combustion of conventional fuels commonly used in ICE and heat power systems.

In one application of the invention the titanium-base component is embodied in a material having pore sizes ranging from 80 to 200μm and the total porosity of 35 to 60% and selected from the group consisting of titanium, titanium carbide, titanium nitride, and titanium carbonitride, while the copper-base component is a material having pore sizes ranging from 100 to 300μm and the total porosity of 50 to 80% and selected from the group consisting of copper, brass, and bronze.

The above-stated non-obvious effect, which is due to the novel components, may be heightened and can be optimized in some respects. In combustion of clear gasoline and, especially, diesel fuels, leaded brass is practical as the copper-base component, which forms deposits that make for a decrease in friction of piston rings on cylinder liners in high- compression ICE. Electrophysically acceptable metallics, such as titanium nitride, titanium carbide, and titanium carbonitride, are practicable to reduce titanium consumption in production of the filter media of the invention.

As an alternative, a filter medium of the invention may comprise a third porous layer consisting of zinc and having pore sizes ranging from 100 to 300 μm and the total porosity of 50 to 80%.

Preferably, said third porous layer is arranged between the layer of the titanium-base component and the layer of the copper-base component, and in contact therewith to provide a galvanic coupling.

According to the second aspect of the invention the above problem is resolved by providing a filter device for liquid fuels, comprising a filter case having an inlet and an outlet for the fuel to be filtered and an active zone in the form of an insert made of layered filter medium including at least one porous layer of a titanium-base component and at least one layer of a copper-base component having a higher normal electrode potential compared with that of titanium, wherein all components of the insert are electronic conductors, the layers thereof are spaced apart but for a portion of the surface to provide a galvanic coupling, the layer of the copper-base component being likewise porous, having a mean pore size and total porosity in excess of those of the layer of the titanium-base component and being arranged upstream from the layer of the titanium-base component.

Such filter device is expected to be of reasonable price and is acceptable in terms of quality, since, apart from removing fine particles, it is suitable for physical and chemical activation of liquid fuels to enhance combustion and reduce harmful emissions. It is also suitable for mounting and is easy to maintain (replacement included). Further, the filter device of the invention is capable of providing fuel with components that offset wear on the surfaces of cylinder and piston assemblies to extend service life of ICE and reduce toxicity of the combustion product and specific fuel consumption.

It is precisely the layer of the copper-base component, partially consumable (and individually replaceable), being more porous and arranged upstream from the layer of the titanium-base component that accumulates the major portion of mechanical impurities present in liquid fuels to thereby extend the service life of the layer of the titanium-base component. In one contemplated application of the invention, the layer of the titanium-base component is grounded or is in galvanic connection with the frame of a facility equipped with an ICE, and in doing so the potential difference to sustain galvanic corrosion in the layer of the copper-base component is provided continuously. This is a prerequisite for accumulation of ions of copper and associated metals in the fuel that remains in the filter device while the ICE is dead.

In one embodiment of the invention, the layer of the titanium-base component is an axially symmetric cup, while the layer of the copper-base component is a disk (generally flat) fitted in said cup to provide a galvanic coupling therewith along its circumference. This arrangement provides for ease of assembly and replacement of filter parts. It will be appreciated that for ease of production of the cup may be a solid of revolution, cylindrical or conical, a prism or a frustum of a pyramid with equal lateral faces.

In another embodiment a primary filter consisting of a porous layer of stainless steel having pore sizes ranging from 100 to 300 μm and the total porosity of at least 50% may be arranged upstream from the layer of the copper-base component on the side of the inlet. Such part is easily back purged to thus extend the service life of the filter device as a whole.

As an alternative, a porous layer consisting of zinc and having pore sizes ranging from 100 to 300 μm and the total porosity of 50 to 80 % may be arranged between the layer of the titanium-base component and the layer of the copper-base component.

As a further alternative, a discrete layer of pellets or tablets as a source of metals known to form brass is further arranged between the titanium-base layer and at least one other layer, the pellets or tablets of said discrete layer being comprised of a mixture of at least one ionic compound of copper and at least one ionic compound of zinc in a ratio of 0.03 to 0.70 mole of zinc per mole of copper, and at least one organic substance that promotes dissolution of salts of said metals in hydrocarbon fuels.

Such part of the filter device, consumable and readily replaceable, is able to dissolve in minor amounts of water, which are common in hydrocarbon fuels, let alone the alcohol fuels. This feature allows substantially greater amount of ions of brass-forming chemical elements to be introduced into each fresh fuel charge (typical consumption of salts being 0.5 to 5.0 g per metric ton of fuel) as compared to the galvanic corrosion of the copper-base component. Furthermore, interaction of liquid fuels with copper and zinc within cylinders upon each operating cycle of ICE produces a mixture of neutral atoms of copper and zinc due to reduction of metal ions. This mixture is attracted to cooled cylinder liners and readily forms (and keeps invariable as to thickness) a microfilm of brass over virtually all surface of contact with the pistons to thereby offset wear.

It is to be emphasized that in case of leaded gasoline much of lead is incorporated into the resulting brass to improve anti-friction properties of the latter. This controlled-to-advantage and so called 'routine maintenance' to the cylinder liners, while the ICE is running, has a beneficial effect on compression with an associated increase in specific power and decrease in specific fuel consumption, and the longer such "part" is in use, the more noticeable the effect.

Inasmuch as the salts enter the fuel immediately before it is mixed with air (and with fuel gas, if added), they are evenly distributed within the fresh charges. That is why, ions of said metals, before being reduced and deposited as atoms, have time to act as catalysts in combustion. In so doing they serve to even up temperature within the combustion chambers in a more effective way than by activating filtration only and thereby further suppress NO_x formation at peak temperatures and facilitate combustion of hydrocarbon fuels to produce harmless CO₂ and reduce harmful exhaust in general.

The term «mole» as applied to metals known to form brass is hereinafter used to mean a corresponding metal in kilograms numerically equal to its atomic weight, but when applied to the ingredients, such as oxyquinoline and the like, it is a corresponding substance in kilograms numerically equal to its molecular weight. In this instance, molar ratios are pre-assigned to mean pure metals without regard for anions, cations or oxides thereof, present in the filter of the invention, as well as for water of hydration, should it be present in metallic compounds.

According to a further embodiment of the invention said organic substance is selected from the group consisting of oxyquinoline, cupferron, neocupferron, and an unspecified chelate compound out of a multitude of aminopolycarboxylic acids attractive due to their efficiency as well as availability.

A still further embodiment of the invention consists in that the pellets or tablets of said discrete layer further comprise at least one ionic or covalent compound of tin in an amount of 0.16 to 0.40 mole of tin per mole of copper. Tin salts as well as salts of copper and zinc are soluble in water, while tin oxide easily converts into a soluble form in presence of water and traces of acids in the fuel and further controls composition and properties of brass that is forming deposits on the surfaces of cylinder and piston assemblies in ICE as they wear away.

According to the invention the pellets or tablets of said discrete layer may further comprise at least one ionic compound including a metal selected from the group consisting of lead, molybdenum, tungsten, vanadium, nickel, silver, and zirconium, in an amount of 0.008 to 0.010 mole of lead and/or 0.010 to 0.32 mole of molybdenum, and/or 0.010 to 0.22 mole of tungsten, and/or 0.020 to 0.50 mole of vanadium, and/or 0.004 to 0.40 mole of nickel, and/or 0.004 to 0.115 mole of silver, and/or 0.005 to 0.40 mole of zirconium. Such additives offer more precise selection of brass compositions to be deposited under specific conditions and (what particularly counts) selective catalysis in the process of combustion of various fuels as to composition and purpose.

It is preferred that the pellets or tablets of said discrete layer further comprise at least one organic substance capable of rendering metal salts (usually by complexing) soluble in hydrocarbon fuels.

Brief Description of the Drawings

The invention is illustrated in the drawing which is a schematic representation of the filter medium of the invention shown as a layered structure with an active zone of the filter device for liquid fuels, the case of the filter device being removed.

Best Mode for Carrying Out the Invention

The invention will now be described with reference to the accompanying drawing by way of presenting starting materials, method of producing and specific examples of filter media, advisable uses thereof and test results.

Referring to the drawing, the filter medium of the invention comprises components that are electronic conductors and are suitable for use in filter devices for separation of solids from liquid fuels while activating the latter. The components form the following structural parts: a rigid porous layer 1 of a titanium-base component, a rigid porous layer 2 of a copper-base component, a rigid porous layer 3 of zinc (optional), a rigid porous layer 4 of stainless steel (optional), and a discrete layer 5 of pellets or tablets a composite additive to liquid fuels (optional as well).

Also, there is shown a grounding electrode 6 connected to the layer 1 and forming part of the filter device only.

The layers 1 and 2 herewith are essential parts of the structure, while the layer 3 is an optional component of the filter medium of the invention. With regard to geometry and arrangement of the layers relative to the flow of fuel to be filtered the layers 1 through 5 can form part of an active zone of the filter device according to the invention.

Being a component of the filter medium, the layer 1 can consist either of pure titanium (e.g. powder of predetermined fineness that was sintered in vacuum or in an inert gas, such as argon, or premolded felt-like structure of a predetermined diameter titanium wire lengths) or of titanium nitride, titanium carbide, or titanium carbonitride that are electron conductors. This layer has pore sizes ranging from 80 to 200 μm at 35 to 60% total porosity.

The layer 2, being a component of the filter medium, is typically made of copper or of a suitable kind of brass, specifically leaded brass, or of a suitable kind of bronze, and it is to have pores of 100 to 300μm in size at total porosity ranging from 50 to 80%, which is more than in the layer 1.

The layer 2 is not only a means for the removal of particles from fuels, but an ion contributor as well, since it has a higher normal electrode potential than the titanium-base layer 1. Therefore, water and traces of acids, common in liquid fuels, induce partial galvanic corrosion in the layer 2. Pure copper as the layer 2 is preferably useful in filtering leaded gasoline because combustion of leaded gasoline in ICE results in leaded brass-like material which produces deposits on the walls of cylinder and piston assemblies. Brass and bronze are preferred in the layer 2 in case of clear gasoline or fuels for jet and diesel systems.

The layer 3, being a component of the filter medium, consists of porous zinc of 100 to 300 μm pore sizes at total porosity ranging from 50 to 80%. Zinc readily corrodes against a titanium background and in the presence of copper to thereby enhance deposition of brass micro-layers on the parts of cylinder and piston assemblies upon combustion of unspecified fuel mixtures in ICE.

Any combination of the layers (the layers 1 and 2 or 1, 2, and 3) with the proviso that part of their respective surfaces form a galvanic coupling, does contribute to a noticeable reduction in harmful exhaust, while wear on the parts of cylinder and piston assemblies or combustion chambers of unspecified ICE is offset to some extent, when filtered fuels are burnt.

In the structure of a filter device, the layer 1 as a cylindrical cup is preferred, though other preferably axially symmetric shapes are contemplated, such as a cone, pyramid, prism and so on. The layer 1 may be shaped as a disk fitted in a filter case (not shown) so as to provide a galvanic coupling with at least the layer 2 or the layers 2, 3.

In the structure of the filter device, the layers 2, 3, and 4 are specifically disks of constant thickness, each being in contact along its circumference with the side wall of the cylindrical cup, or the layer 1, to thereby provide a galvanic coupling therewith. It is to be understood that the layers 2, 3, and 4 are useful in other shapes as well, such as disks of variable thickness like biconvex, biconcave, planoconvex or planoconcave lenses; convex or concave disks of constant thickness; stepped preferably axially symmetric insert pieces and so on. The choice of shape will only be guided by mounting and replacement considerations. Also, all or some of the axially aligned layers 2, 3, and 4 can be axially spaced apart to accumulate filtered off particles in the thus provided spaces.

The layer 4, being a relatively self-contained part - primary filter, and having pore sizes ranging from 150 to 300 μm at total porosity of at least 50%, is preferred as a pre-molded feltlike structure of a predetermined diameter wire lengths and arranged so in the case of the filter device as to be the first in the stream of the fuel being filtered.

As a consumable part of the filter device the discrete layer 5 is preferably arranged either between the portion adjoining the bottom of the porous cup, being a shape of the titanium-base layer 1 of the filter device, and the copper-base porous layer 2 or between the layers 1 and 3, provided zinc is present in the filter. To pass liquid fuels containing minimal amounts of particulate admixtures the layer 5 can be arranged between the layers 4 and 2.

It is to be understood that, among the above-described active parts of the filter device, there may be used some inactive parts, e.g. inserts consisting of one or several layers of polyamide or basalt web to retain pellets as the layer 5.

Various compositions to prepare filter media and various designs of filter devices were tested to ascertain that the invention is practicable. The following data however relate to the simplest compositions and designs, for even so the 'routine maintenance' effect upon parts of cylinder and piston assemblies in ICE has been achieved together with a reduction in specific fuel consumption and harmful exhaust.

The filter devices further designated FI, F2, and F3 were constructed from materials having a composition (pore sizes and porosity included) and disposed in the layers arranged in a downstream order as shown in Table 1. Salt pellets for the layer 5 were prepared from active ingredients and in proportions that correspond to some volumes borrowed from Table 2 and in specific molar amounts presented by specific examples that follow.

Table 1

Composition of active parts, mean pore sizes (μm) and porosity (%) in the layers of filter devices tested

Table 2

Some concentrations of active and accessory ingredients in composite additives

Notes: (a) «copper/other ingredients» ratios are calculated for metals only, irrespective of whether they are introduced as cations, anions, or oxides;

(b) column 7 shows preferred mean amounts of ingredients in moles per mole of copper;

(c) salt additives may comprise the above-exemplified ingredients in any combination and may be used in whatever amounts desired.

In preparing porous layers of titanium, brass, copper, and zinc, use was made of conventional powder metallurgy methods of sintering respective powders in protective atmosphere. The titanium layer was shaped as a cup of 70 mm in diameter and 60 mm in height with the wall thickness of 6.0 mm, while the layers of brass, copper, and zinc were shaped as flat disks of 58 mm in diameter and 10 mm thick and were fitted in the porous titanium cup so that spaces of 5 to 6 mm between the layers and 20 mm between the last layer and the bottom of the cup were allowed. The latter spacing was filled with salt pellets of about 10 mm in diameter and about 5mm thick fixed with the help of inert substance in the form of polyamide fibers.

The pellets as consumable material of the layer 5 were prepared from formates, acetates, oxalates, and tartrates of copper, zinc, tin, and lead. Other salts of these metals with inorganic anions, such as nitrates or chlorides, and organic anions, such as propionates, butyrates, etc., can also be utilized. Molybdenum, tungsten, and vanadium are preferred as the MoO ^", WO ^", and VO ^" anions existing in commonly known salts of sodium, potassium or ammonium, which are to be understood as nonlimiting examples. Nickel and silver are preferably useful as nitrates, while nickel alone is acceptable as sulfates or water-soluble salts of lower monocarboxylic acid or lower bicarboxylic acid. Zirconium is preferred in additives as zirconium oxychloride hydrate. And finally 8-oxyquinoline (C₉H₇ON), cupferron (an ammonium salt of N- nitrosophenyl-hydroxylamine C₆H₉O₂N₃), neocupferron (an ammonium salt of N- nitrosonaphthyl-hydroxylamine) and an unspecified chelate compound out of a multitude of aminopolycarboxylic acids are useful either separately or in combination and in amounts sufficient to form complexes with corresponding ions of brass-forming metals and to become soluble in hydrocarbons.

It is to be understood that other readily available compounds useful in the filter device and suitable for producing filter media of the invention may be used along with those that have already been specified and which are capable of replacing some of them.

Consequently, zirconium oxychloride hydrate may be replaced by or used together with Seignette's salt (potassium sodium tartrate) or with alums, e.g. potash alum, ammonium vanadic alum, and so on, having 12 to 24 molecules of water of hydration, as inherent sources of moisture which, by interacting with the salts of brass-forming metals, assist in dispersing the latter throughout the dehydrated fuels.

And lastly, combustible binders that are soluble in water and/or liquid hydrocarbons, such as methyl- or carboxymethyl cellulose, polyvinyl alcohol, etc., may be used along with the specified active substances that are contributors of brass metals and optionally with auxiliary substances that assist in dispersing the active substances throughout the liquid fuels. The above mentioned substances are useful in preparing durable tablets or pellets from the active and auxiliary substances.

The material for the layer 5 was prepared as follows:

(a) specific formulations of the basic components of a composite source of brass-forming metals represented by a list of required ions were selected within the exemplary proportions of ingredients in Table 2, having regard, in particular, to the following factors and recommendations :

- presence of antinock agents in a liquid hydrocarbon fuel, e.g. no lead to be used in additives to leaded gasoline while it is desirable in additives to clear gasoline, especially to diesel fuels,

- ICE wear prior to the filter device being used (the greater the wear determined by comparing actual compression or power to the rating data of the engine, the more desirable multiple-component additives, while a simple combination of ionic compounds of copper and zinc, and, if desired, tin is sufficient for new engines).

- water content in the fuel (with at least one complexing agent and/or inherent source of water of hydration to be added to anhydrous fuels) and

-flash point t°_π and boil-off temperatures t°_\o, t°₅₀, t°ιoo of the respective 10%, 50%, and 100% of fuel (the thicker the fuel in the following order: gasoline, kerosene, diesel fuel, and fuel oil and the higher said temperatures, the greater amounts of metallics with their higher concentrations in the layer 5 are used);

(b) among commercially available compounds chosen were those having ions selected at stage (a), and required amounts of the chosen compounds (a complexing agent and hydrated compound included if required) were determined by the methods usually employed in the chemical arts with due regard to the selected molar ratios.

(c) the required amounts of the compounds determined at stages (a) and (b) were measured out;

(d) the measured out amounts of the chosen compounds were disintegrated and thoroughly mixed, then

(e) the mixture produced was shaped (with binders if required) as tablets or pellets.

The active zone of the filter device, defined by an assortment of the above-described filter medium layers, was assembled in the porous cup (the layer 1) of the titanium-base component. Such cups were fitted into filter cases provided with means for connecting the same into the fuel conveying system of ICE. Then, assembled filter devices were connected into the fuel conveying systems and tested.

Example la

The active zone of the filter devices tested was of the composition of FI as in Table 1. The brass in the layer 2 contained copper and zinc in the molar ratio of 1 Cu to 0.4 Zn. The filter devices were used for removing particles and activating leaded fuels inherently containing water, with an octane number of 76, in the fuel conveying systems of 4-cylinder gasoline engines of 6 economy cars that had already run 5,000 to 6,000 km each.

A 600 km run in the test showed compression in the ICE cylinders of all the cars level off and increase by an average of 3.0% compared with that at the beginning of the test, while fuel consumption per 100 km run under urban conditions was decreased by 3%, and CO, CH, and NO_x were decreased by 20, 45, and 16% respectively with lead in exhaust gases practically nonexistent.

Example lb

The cars as in Example la were used in further tests but the active zone of the filter device FI also contained tablets prepared from a mixture of copper acetate, tin dioxide, ammonium molybdate, ammonium tungstate and ammonium vanadate, nickel nitrate, hydrated zirconium oxychloride, and Trilon B, all present in the molar ratio of

[Cu]:[Sn]:[Mo]:[W]:[V]:[Ni]:[Zr]:[Trilon B]= -1:0.25:0.15:0.15:0.25:0.20:0.25:0.03.

A 150 km run in further tests was enough to observe compression in the ICE cylinders of all the cars further increase by an average of 4.0%, while fuel consumption per 100 km run under urban conditions decreased by 6% and CO, CH, and NO_x content decreased by 95, 70, and 35% respectively compared with those at the beginning of the test. Lead in exhaust gases was not observed.

Example 2a

The active zone of the filter devices tested was of the composition of F2 as in Table 1. The filter devices were used for removing particles and activating clear gasoline inherently containing water, with an octane number of 95, in the fuel conveying systems of gasoline engines of 4 VOLGA taxicabs that had already run about 25,000 km each.

A 400 km run in the test showed compression in the ICE cylinders of all the cars level off and increase by an average of 3.5% compared with that at the beginning of the test, while fuel consumption per 100 km run under urban conditions was decreased by 4% and CO, CH, and NO_x were decreased by 26, 48, and 17% respectively.

Example 2b

The cabs as in Example 2a were used in further tests but the active zone of the filter device F2 also contained tablets prepared from a mixture of copper sulfate pentahydrate (CuSO₄ ^•5H₂O), zinc acetate, lead acetate, ammonium molybdate, ammonium tungstate, ammonium vanadate, nickel nitrate, silver nitrate, and hydrated zirconium oxychloride with additioin of cupferron, all present in the molar ratio of

[Cu] : [Zn] : [Pb] : [Mo] : [ W] : [V] : [Ni] : [ Ag] : [Zr] : [cupferron]- = 1.0:0.70:0.100:0.32:0.22:0.50:0.40:0.115:0.40:0.70.

After a 150 km run in further tests, compression in the ICE cylinders of all the cabs further increased by an average of 2.50%>, while fuel consumption per 100 km run under urban conditions decreased by 6.5% and CO, CH, and NO_x decreased by 92, 72, and 32% respectively compared with those at the beginning of the test.

Example 3 a

The active zone of the filter devices tested was of the composition of F3 as in Table 1. The filter devices were used for removing particles and activating commercial grade winter diesel fuels inherently containing water, in the fuel conveying systems of 8-cylinder diesel engines of 2 trucks of load carrying capacity up to 8 metric tons, which had already run about 35,000 km each.

Prior to the tests, i. e. without the filter device of the invention, carbon black in the engine exhaust of both trucks was visible at each getaway, in uphill runs and full-load runs, while CO, CH, and NO_x in exhaust gases were on the average 15% in excess of allowable limits.

After a 900 km run in the test with the additive, compression in the engine cylinders of both trucks practically leveled off and increased by an average of 8.5% compared with that prior to the test, fuel consumption per 100 km run under urban conditions decreased by 6%, carbon black in the exhaust was faintly visible only in uphill runs at full loads, while CO, CH, and NO_x in the exhaust gases decreased by 45, 32, and 15% respectively compared with those prior to the test. Example 3b

The trucks of Example 3a were used in further tests but running on dehydrated winter diesel fuel, and the active zone of the filter device F3 contained tablets prepared from a mixture of copper sulfate pentahydrate, lead formate, ammonium molybdate, ammonium tungstate, ammonium vanadic alum, nickel nitrate, oxyquinoline, all present in the molar ratio

[Cu] : [Sn] : [Pb] : [Mo] : [ W] : [V] : [Ni] : [oxyquinoline] =

= 1.0:0.50:0.100:0.32:0.22:0.50:0.40:0.40:0.70.

After a 500 km run in further tests, compression in the engine cylinders of both trucks increased by an average of 15.5%, while fuel consumption per 100 km run under urban conditions decreased by 11%, carbon black was not observed, and CO, CH, and NO_x decreased by 59, 70, and 24%> respectively compared with those at the beginning of the test.

Industrial Applicability

Compared with catalytic reactors for use in exhaust pipes for burning exhaust gases, the filtering medium and the filter device for liquid fuels as hereinbefore described can be used as alternative means for reducing toxicity in exhaust gases of a major pollutant of the environment, such as automobiles. Also, the filtering medium and the filter device of the invention will produce the same effect if used in other heat power systems that burn liquid fuels and where such reactors are not utilized.

When used with piston engines, the present invention provides for a means of fundamental importance for offsetting wear on the surfaces of cylinder and piston assemblies while engines are running to thereby decrease specific fuel consumption and increase specific power of internal combustion engines.

Claims

C L A I M S

1. A filter medium for liquid fuels, comprising at least one porous layer of a titanium-base component and at least one layer of a copper-base component having a higher normal electrode potential compared with that of titanium, characterized in that all the components are electronic conductors, and the layers thereof are spaced apart but for a portion of the surface thereof to provide a galvanic coupling, the layer of the copper-base component being likewise porous and having a mean pore size and total porosity in excess of those of the layer of the titanium-base component.

2. A filter medium according to claim 1, characterized in that the titanium-base component is a material having pore sizes ranging from 80 to 200 μm and the total porosity of 35 to 60% and selected from the group consisting of titanium, titanium carbide, titanium nitride, and titanium carbonitride, while the copper-base component is a material having pore sizes ranging from 100 to 300 μm and the total porosity of 50 to 80% and selected from the group consisting of copper, brass, and bronze.

3. A filter medium according to claim 1, characterized in that a third porous layer is incorporated therein, said layer consisting of zinc and having pore sizes ranging from 100 to 300 μm and the total porosity of 50 to 80%>.

4. A filter medium according to claim 3, characterized in that said third layer consisting of zinc is arranged between the layer of the titanium-base component and the layer of a copper- base component in a galvanic coupling therewith.

5. A filter device for separating solids from liquid fuels while activating the latter, comprising a filter case having an inlet and an outlet for the fuel to be filtered and an active zone in the form of an insert made of a layered filter medium including at least one porous layer of a titanium-base component and at least one layer of a copper-base component having a higher normal electrode potential compared with that of titanium, characterized in that all components of the insert are electronic conductors, the layers are spaced apart but for a portion of the surface thereof to provide a galvanic coupling, the layer of the copper-base component being likewise porous, having a mean pore size and total porosity in excess of those of the layer of the titanium-base component and being arranged upstream from the layer of the titanium-base component.

6. A filter device according to claim 5, characterized in that the layer of the titanium-base component is grounded or is in galvanic coupling with the frame of a facility equipped with an internal combustion engine.

7. A filter device according to claim 5, characterized in that the layer of the titanium-base component is an axially symmetric cup, while the layer of the copper-base component is a disk fitted in said cup to provide a galvanic coupling therewith along its circumference.

8. A filter device according to claim 7, characterized in that a primary filter consisting of a porous layer of stainless steel having pore sizes ranging from 150 to 300 μm and the total porosity of at least 50%> is arranged upstream from the layer of the copper-base component on the side of the inlet.

9. A filter device according to claim 7, characterized in that a porous layer consisting of zinc and having pore sizes ranging from 100 to 300 μm and the total porosity of at least 50 to 80%) is arranged between the layer of the titanium-base component and the layer of the copper- base component.

10. A filter device according to claim 7, characterized in that a discrete layer of pellets or tablets as a source of metals known to form brass is further arranged between the layer of the titanium-base component and at least one other layer, the pellets or tablets constituting said discrete layer comprising a mixture of at least one compound of copper with ionic bonds and at least one compound of zinc with ionic bonds, taken in the ratio of 0.03 to 0.70 mole of zinc per mole of copper, and at least one organic substance to promote dissolution of said metal salts in hydrocarbons of the fuel being filtered.

11. A filter device according to claim 10, characterized in that said organic substance is selected from the group consisting of hydroxyquinoline, cupferron, neocupferron, and unspecified chelate compound out of a multitude of aminopolycarboxylic acids.

12. A filter device according to claim 11, characterized in that the pellets or tablets further comprise at least one compound of tin with ionic or covalent bonds, the ratio being 0.16 to 0.40 mole of tin per mole of copper.

13. A filter device according to claim 11, characterized in that the pellets or tablets further comprise at least one compound with ionic bonds, including a metal selected from the group consisting of lead, molybdenum, tungsten, vanadium, nickel, silver, and zirconium, the ratio being 0.008 to 0.010 mole of lead, and/or 0.010 to 0.32 mole of molybdenum, and/or 0.010 to 0.22 mole of tungsten, and/or 0.020 to 0.50 mole of vanadium, and/or 0.004 to 0.40 mole of nickel, and/or 0.004 to 0.115 mole of silver, and/or 0.005 to 0.40 mole of zirconium per mole of copper.