US2079475A - Fuel oil wlteb construction - Google Patents

Description

May 4, 1937.

F' WILLIAMS El AL FUEL OIL FILTER .CONSTRUCTION Filed June 5, 1936 2 Sheeis-Sheet 1 y- 1937- P. WILLIAMS ET AL I 2,079,475

FUEL OIL FILTER CONSTRUCTION Filed June 5. 1936 2 Sheets-Sheet 2 Patented May .4, 1937 nrs'r oFFicE FUEL OIL FILTER CONSTRUCTEGN Paul Williams and Frank W. Brazel, Detroit,

Mich, assignors to Skinner yurifier's ind, De-

troit,

Mich, a corporation of Delaware Application June 5, 1936, Serial No. 83,754

4 Claims.

During the past few years there has been active interest inmaking internal combustion engines in which the fuel is distributed to the cylinders by means of positive-pressure fuelpumps, this principle being imperative in Diesel engines which depend upon the high-pressure pumps to force a predetermined quantity of fuel into the individual cylinders at the proper time for combustion.

Positive-pressure pumps are also used with the Hesselman type of engines wherein the fuel-oil is forced into the cylinders and ignited by sparkof back pressure in order that it shall not open against the explosion of the mixture in the cylinder, but is opened by the pressure of fuel coming up to the valve.

These valves or injectors must have very close clearances, and the high-pressure pumps require minute clearance as the presures under which these pumps operate are about 5000 pounds to 7000 pounds liquid pressure, and if the moving parts had excessive clearances, the liquid would be forced through them.

It has been found that when using these units the greatest difficulty in proper operation of the high-speed Diesel engines, which necessitate the employment of these excessively fine mechanisms, is the wear which is encountered from the small particles of carbon and flake mixture present in'these fuels, such impurities being more prevalent in the heavier fuels, but, the lighter the fuel, the smaller the particles which would cause difficulty. 4

The present invention, therefore, relates to improved filter-means which will positively and mechanically filter these oils or fuels to a sufficient fineness to insure the high-pressure pumps and nozzle parts against excessive 'wear; or, stated somewhat differently, this invention concerns certain features of betterment and advantage in filters, more particularly, but not necessarily exclusively or restrictedly, those of the socalled streamline type which are especially adapted for the employment in the relation specified.

One of the leading aims of the invention is to provide a simple structure of this style which can (Ci. 2l0134) be easily andreadily cleaned or flushed without interrupting the filtering operation.

Another object of the invention is to supply a filter of this kind which is particularly adapted to filter the liquid fuel flowing to an internalcombustion engine, such character of filter being of particular advantage in cleaning the pumped fuel prior to its use in an internal-combustion engine of the fuel-injection design, using highpressure pumps for forcing the fuel into the engine, it being apparent that such pumps must be maintained free from injurious foreign mat-.

ter toavoid damage due to the necessary snug fits of their moving parts.

A further purpose of the invention is to provide a design of filter which can be flushed or cleaned without danger of admitting air into the fuelsystem, this being a highly important characteristic of the novel filter.

To enable those acquainted with this art to fully understand this invention and the benefits accruing from its employment, present preferred embodiments of the same have been illustrated in the accompanying drawings, forming a part of the specification, and to which reference should be had in connection with the following detailed description, like reference numerals being employed in these drawings to designate the same parts.

Referring to these drawings:-

Figure 1 is a central, vertical section through the improved filter construction;

Figure 2 is a horizontm section on line 2--2 of Figure 1;

Figure 3 is a partial end elevation and partial vertical section of the construction;

Figure 4 is a fragmentary, enlarged section through one ofthe filter chambers;

Figure 5 illustrates a modified construction partially in elevation and partially in section; and

Figure 6 is a detail section of one of the valves employed in the structure of Figure 5.

Referring first to the design or form of the filter presented in Figures 1 to 4, inclusive, it will be perceived that it comprises a. casing or housing ll divided into a number (in the present instance three) of compartments l0, ID by upright, transverse or cross walls or partitions l2, l2, each such compartment being covered at its top end by a centrally-apertured disc l3, all three of which are held down firmly on the top of the casing by an appropriate number of securing screws It, M.

Each such compartment or chamber accommodates one of the filter-packs If, each composed of a lower or bottom, metal disc IS with a large number of superposed, registered, centrally-apertured or washer-like filter-discs I1, for example, made of paper charged or impregnated with a material not soluble in the liquid to be filtered.

Internally each such filter-pack accommodates a long, coiled, contractile spring l8 secured in any approved manner at its lower end at i9 to the center of the corresponding end disc IS, the upper end of the spring having a terminal 100p 2| occupying a peripheral groove in a short rod or cross-pin 22 resting or bearing on the top of the correlated cover H on opposite sides of the central aperture of the latter, such end loop of the spring being in the cover aperture referred to.

Thus theseseveral springs hold the numerous discs ll of their respective packs in firm contact or engagement with one another, thefiltering action occurring between, rather than through, the paper discs.

Casing Ii is provided with a hollow cover 23 securely held thereon by a number of screws 24, 24, or in any other appropriate manner, a suitable gasket 25 being interposed between the two elements I I and 23 to make the joint pressure-tight, the casing in this manner being-provided with an upper chamber 26 having an outlet pipe 27 connected to a high-pressure pump or pumps, shown diagrammatically and supplied with the reference numeral Hill.

At its lower part casing H has a single, inlet manifold-passage 28 in the casting forming the casing, such passage being intersected for each of the three filter-stack compartments by a screwthreaded opening 29 communicating at its inner end with a small well 3| forming part of, or being directly connected to, the corresponding filterpack compartment l0. 7

Each such opening or passage 28 accommodates the threaded shank 32 of a hollow valve-screw having an external, angular head 33, such shank or stem having a central, longitudinal passage 3% closed at its outer end and open at its inner end, and having one or more lateral openings or ports 35 in register with, and communicating with, the manifold-passage 28 when the screw-valve is turned 'fully home as presented in Figure 3.

One end of the manifold-passage 28 is closed, 1 its companion opposite end being joined to a.

fuel-oil inlet-pipe connected to a low-pressure pump Hill, the delivery pipe 21 being joined, as

already explained above, to the high-pressure pump I06, which feeds the fuel for injection into the cylinders of the internal-combustion engine, not shown.

The filter operates practically as follows:

Assuming that all of the three screw-threaded valves 32--33-3-35 are screwed fully home in the position shown in Figure 3, so that the passage 28 is in direct connection with all three of the compartments l through the openings 35, 3%, 3i, the fuel-oil enters the manifold-passage 28, being delivered thereinto by the lowpres-- sure pump lQLfiows through the three valves into the chambers i8, i0, passes between the paper-discs of the filter packs into their interiors, from whence it flows into chamber 26 and then through the discharge-pipe 2'! to the high-pressure pumps which force it or inject it into the engine-cylinders at the proper moments.

In time, the exterior surfaces of the filterpacks become coated or overlaid with a stratum of filtered-out impurities which layer it is essential shall be removed from time to time without interrupting the operation of the filter as a whole and without permitting the entrance of any air into the system, which, if it occurred, would seriously interfere with the eflicient' and proper functioning of the associated engine.

This cleaning may be readily accomplished for the filter-packs individually one at a time by causing a reverse flow of some of the cleaned oil through the filter-pack under consideration.

The screw-threaded valve 3Z-33, associated with the filter-pack selected for cleaning, is turned by means of its head until its ports 85 have been shifted away from the passage 28 and are positioned outside of the casing or casting H for drainage purposes, as presented in Figure 4, the threaded stem 32 of the valve being suificiently long to maintain the passage 28 closed.

Accordingly, now none of the impure o-r unfi1-, tered oil can, enter that particular filter-pack chamber and the pressure already inside of the filter-pack, which is in direct connection with the chamber 26, forces oil out of the filter-pack between its discs into the chamber I!) from which it flows out through the connected passages 3|, 3 4i and 35 from which it discharges into' any sort of a container'or onto the ground or elsewhere. The cross-section of the passages of the valve through which the drained-off oil flows is such that they are maintained full of the liquid for all of the period of such drainage, thus preventing any entrance of air into the system, this being an important consideration.

This inverse oropposite oil-flow through the filter-pack washes off the impurities from its,

outer surface and carries them down and along with the oil which is discharged outside of the appliance in the manner'stated.

While this cleaning or reverse flushing of one of the filter-packs is taking place, the normal filtering operation is occurring continuously through the other packs, so that there is no interruption of proper, clean, fuel-oil feed to the engine.

. When such filter-member has been suficiently flushed to clean or recondition it adequately, its

valve is again screwed in until its ports 35 coincidewith the passage 28; whereupon the normal or ordinary operation of that particular section of the complete filtering-apparatus is again restored, drainage therefrom having been terminated just as soon as the ports 35 were inside of the casing.

As will be readily understood from what precedes and from the illustrations in the drawings, the valve-stem 32 is sufliciently long and the parts are so located and spaced, that the filterpack is either in operation, or undergoing washing and drainage, or blocked against either of such actions when the ports 35 are closed by the walls of holes 29, the distance between passage 28 and the outside of the casing being such as to keep the ports 35 closed, if desired, whereby that section of the filter-apparatus is inoperative, neither filtering nor cleaning then being accom' plished.

After any one of the filter-elementshas been thus flushed or purged and again restored into operation, the other packs may be treated in the same way individually.

From what'has been stated above it should be clear that this improved filter construction consists of two or more separate compartments with one or more filter-packs in each of these compartments, the fuel-oil entering the unit from the low-pressure pump through the bottom inletmanifold, passing up around the filter-packs, between the discs thereof; up throughthe center passages in the packs, and outof the top header, this operation leaving all of the solid impurities on the outer surfaces of the filter-elements.

capacity than the high-pressure pumps to which it is feeding the fuel, the only purpose of the low-pressure pump being to be certain that the high-pressure pumps fill full of fuel at each stroke, as otherwise the fuel charge would not be of the right quantity.

Accordingly, the liquid fuel flows up through the filter and into the high-pressure pumps, and as it does so the solid impurities gradually build up on the exteriors of the filter-packs until the resistance to the fuelrfiow becomes so great that the filter cannot furnish sufiicient fuel for the engine at high operating speeds.

Then, the operator idles the engine which causes the high pressure pumps to require less fuel, and the pressure in the head or top of the filtering apparatus builds higher if the fuel is not taken away from it as rapidly as the filter can perform its function.

, Thereupon the operator opens one of the valves at the bottom of the filter which closes off the low-pressure pump from that particular compartment of the apparatus and leaves the valve in the flushing position, so that the fuel can flow freely from such compartment.

The fuel pressure in the head or compartment 26 of the unit then washes the dirt oil the filter by back or reverse flow therethrough and the fuel used for that purpose passes out onto the ground or into any appropriate container.

When the discharging liquid starts to show clear the valve is closed and that filter-compartment has a clean filter-pack ready again for full production.

This operation is repeated for the various compartments of the filter unit, and in this manner the operator is afforded an appliance which does not require frequent changes of filter-packs, does not need to be opened up for cleaning purposes, and can be successfully handled by the average operator, the filter being capable of being cleaned on the road where operators have ordinarily heretofore been careless with respect to their preventative maintenance.

As has been stated, one outstanding distinct advantage of the new construction is that ,by making the holes or passages in the valve of such size that the fiowing'out of the liquid fills these passages/it is impossible for air to enter the system, and this is of paramount importance in the operation of fuel-pumps.

' A modified style of structure is shown in Eigures 5 and 6 and in this somewhat-different apparatus a plurality of casings or housings 36, 36 are used, two in this instance being shown, although a greater number may be availed of if desired.

Each of these casings contains a number of filter-packs l5, l5 of the same construction, and

. mounted in the same manner, as the packs alpassage 48 through it and a branch passage 41 connected therewith, which construction permits a connection between the pipes 43 and 31 for admitting the fuel-oil into the casing, or allows a connection between pipes 31 and M for cleaning and drainage purposes, depending upon the position of the valves which may be operated by their handles.

A portion of pipe 43 between the two valves is joined by piping 48 to a low-pressure pump 49 which feeds the liquid to be treated into and through the filter-apparatus, which at its top has a pipe 5| joining together the two delivery or discharge ports or openings of the pair of casings, such pipe 5| being united to a high-pressure pump 52 by a pipe 53.

As in the previous instance, the filtering elements or packs are arranged in parallel relation, that is to say. the two shells or housings 36, 35 and their filter-packs are in parallel relation as distinguished from a series arrangement.

Assuming that the two valves 39, 39 are in such positions that the contents of the pipe 43 enters the bottom of both casings, the incoming fuel-oil, fed by the low-pressure pump 49, is

filtered in both casings at the same time through their contained filter-packs and is delivered to the high-pressure pump or pumps.

When it is desired to clean or flush the pack or packs of either of the casings, its movable valveplug is turned 90, thereby connecting its pipe 31 to its drain-pipe 4|, the other half of the filterap'paratus remaining in normal operation.

Obviously such turning of the valve efiects a.

. When the cleaning of such set of filter-packs has been completed, its valve 39 is turned back to normal position, thus reestablishing the regular operation of that part of the appliance, and after such reinstatement, the other or companion filtering-means may be freed from accumulated foreign matter in the same manner.

Although only one high-pressure pump has been illustrated diagrammatically in each instance, it will, of course, be understood that such a pump and its injector-nozzle is ordinarily employed for each cylinder of the engine, although a single low-pressure pump of appropriate capacity may be used to supply the fuel to all of the high-pressure pumps.

The invention as defined by the appended claims is not necessarily limited and restricted to the precise and exact details of construction presented nor to these particular embodiments, and more or less radical or minor changes may be incorporated in the constructions without departure from the heart and essence of the invention and without the loss of any of its substantial advantages.

We claim:

1. In a filter-apparatus, the combination of an inlet-conduit for the liquid to be filtered, a discharge-conduitfor the filtered liquid, a plurality of chambers connected to said inlet and discharge conduits in parallel relation to one another, a filtering-means in each of said chambers, a normally-closed drain for each of said chambers on the unfiltered liquid side of its filtering-means, and means to suspend temporarily the feed of impure liquid from said inlet-conduit into any one of said chambers and to open the drain of said chamber, the drainage from said chamber effecting a reverse flow of filtered liquid through the filtering-means of said temporarily-inoperative chamber, whereby the impurities adhering to the surface of said inactive filtering-means are washed away and carried off with thedrained-oif liquid, said inlet-conduit comprising a manifold common to all of said chambers and in which tion it closes such connection with said manifold and drains said chamber through said longitudinal passage and said port.

2. In a filter-apparatus, the combination of an inlet-conduit for the liquid to be filtered, a discharge-conduit for the filtered liquid, a plurality of chambers connected to said inlet and discharge conduits in parallel relation to one another, a filtering-means in each of said chambers, a normally-closed drain for each of-said chambers on the unfiltered liquid side of its filteringmeans,'and means to suspend temporarily the feed of impure liquid from said inlet-conduit into any one of said chambers and to open the drain of said chamber, the drainage from said chamber effecting a reverse fiow of filtered liquid through the filtering-means of 'said temporarily-inoperative chamber, whereby the impurities adhering to the surface of said inactive filtering-means are washed away and carried off with the drained-oil liquid, and in which construction each of said drains is of such capacity that when it is in operation the discharge. of liquid therethrough pre- I vents air entering the system through such drain,

operable valve occupying and movable longitudinally in an opening in the chamber-wall which communicates with the chamber and intersects said inlet-manifold, said valve having a longitudinal passage therein open at one end and having a lateral port connecting with said passage, whereby when said valve is in one position said inlet-manifold is in communication with said chamber through said port and longitudinal passage and when said valve is in another position it closes such connection with said manifold and drains said chamber throughsaid longitudinal passage and said port.

3. In a filter-apparatus, the combination of an inlet-conduit for the liquid to be filtered, a discharge-conduit for the filtered liquid, a plurality of chambers connected to said inlet and discharge conduits in parallel relation to one another, a filtering-means in each of said chambers, a normally-closed drain for each of said chambers on the unfiltered liquid side of its filtering-means, and means to suspend temporarily the feed of impure liquid from said inlet-conduit into any one of said chambers and to open the drain of said chamber, the drainage from said chamber effecting a reverse flow of filtered. liquid through with a pump to feed the impure liquid through said inlet-conduit into said'chambers' and pumpmeans acting at a higher pressure than that of said pump operating on the purified liquid delivered to it through said discharge-conduit, and

'in which structure said inlet-conduit comprises a manifold common to all of said chambers and in which each of said means for suspending the feed of liquid to a chamber and for rendering the drain of said chamber operative comprises" a manually-operable valve occupying and movable longitudinally in an opening in the chamber-wall which communicates with the chamber and intersects said inlet-manifold, said valve having a longitudinal passage therein open at one end and having a lateral port connecting with said passage, whereby when said valve is in one position said inlet-manifold is in communication with said chamber through said port and longitudinal passage and when said valve is in another position it closes such connection with said manifold and drains said chamber through said longitudinal passage and said port.

4. In a filter-apparatus, the combinationof an inlet-conduit for the liquid to be filtered, a discharge-conduit for the filtered liquid, a plurality of chambers connected to said inlet and discharge conduits in parallel relationto one another,,a filtering-means in each of said chambers, a normally-closed drain for each of said chambers on the unfiltered liquid side of its filtering-means, and means to suspend temporarily the feed of impure liquid from said inletconduit into any one of said chambers and to open the drain of said chamber, the drainage from said chamber effecting a reverse flow of filtered liquid through the filtering-means of said temporarily-inoperative chamber, whereby the impurities adhering to the surface of said inactive filtering-means are washed away and carried off with the drained-off liquid, and in which construction each of said filtering-means comprises a series of centrally-apertured, superposed, registered discs substantially impervious to the liquid being filtered and held pressed together, whereby the filtering action occurs between the discs, the liquid undergoing the filtering in the chamber-wall which communicates with the chamber and intersects said inlet-manifold, said valve having a longitudinal passage therein open 'at one end and having a lateral port connected with said passage, whereby when said valve" is in one position said inlet-manifold is in communication with said chamber through said port and longitudinal passage and when said valve is in another position it closes such connection with said manifold and drains said chamber through said longitudinal passage and said port.

PAUL WILLIAMS. FRANK w. BRAZIL.

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