US3435845A - Sludge-eliminating,air-venting,flow-control device - Google Patents

Description

April 1, 1969 D. M. HEBNER 3,435,845

SLUDGE'ELIMINATING, AIR-VENTING, FLOW-CONTROL DEVICE Filed April 15, 1967 Sheet of 2 INVENTOR. 90

DAVID M. HEBNER ATT'Y.

SLUDGE-ELIMINATING, AIR-VENTING, FLOW-CONTROL DEVICE Filed April 13, 1967 D. M. HEBNER Sheetiof? INVENTOR DAVID M. HEBNER @24 Kibw' ATT'Y.

United States Patent ()flice Patented Apr. 1, 1969 3,435,845 SLUDGE-ELIMINATING, AIR-VENTING, FLOW-CONTROL DEVICE David M. Hebner, 1700 Lauderdale Road, Richmond, Va. 23229 Filed Apr. 13, 1967, Ser. No. 630,630 Int. Cl. F23n 1/00 US. Cl. 137563 5 Claims ABSTRACT OF THE DISCLOSURE tank between the connections of the main and return pipes.

This invention relates to fuel oil supply tanks and particularly to tanks of the standard type two-pipe supply and return circulatory systems for supplying fuel oil to a burner system which depends on operation of a pump or pumping system, feeding and delivering measured amounts of fuel oil in uninterrupted flow to a burner nozzle, or system of nozzles.

Since such supply tanks are commonly installed beneath the ground surface, as in the usual household heating systems, and in all such instances where the fuel oil supply tank or vessel is not capable of gravity feed to the burner system, such two-pipe circulatory system is necessary to render the suction through the. feed pipe or line operative in extreme vacuum, and also to return any air picked up and entrapped by the feed line or pipe back to the supply tank, together with the unconsumed fuel oil in the return line or pipe of such circulatory system.

In such two-pipe systems the fuel oil is sucked up from the supply tank through the feed pipe in measured amounts, which vary with the size and number of burners, and may have a wide variation. Assuming a hypothetical example, such as exists in the common household heating system, the ratio of oil supplied per unit of time of operation of the pumping system through the feed line to the burner system to the amount consumed by said burner system may be as high as 12-16 to 1; that is to say, that for every 12 to 16 gallons of fuel oil passing through the circulatory system in any unit of time of operation, only one gallon of fuel oil is consumed by the burner system, the rest being returned to the tank through the return pipe. Though the above hypothetical ratio of amount circulated to that consumed may vary widely according to requirements of service, it is apparent in any instance that the amount of unconsumed oil returned to the tank for recirculation is considerably greater than the amount consumed by the burner system during the same period of operation. Under existing conditions of operation it is evident that in any situation a predominantly greater amount of fuel oil is returned to the tank than that consumed by combustion in the burner system. This returned, filtered oil will become mixed and blended with the unfiltered oil in the supply tank unless some means is provided to prevent such uncontrolled mixing and to direct such previously circulated oil into the feed pipe for continuous circulation without any mixing with the outer contents of the supply tank except the relatively small amounts necessary to replenish the amount consumed by the burner system.

The instant invention has for its object to provide a sludge-eliminating, air-venting, flow-control device for installation in a fuel supply tank of the general type hereinabove mentioned and in cooperation. with the feed and return pipes connected therewith to prevent the mixing of the returned fuel oil with the mass of oil in the tank by providing an open through connection whereby such previously circulated fuel oil is returned to the circulatory system directly. The device also provides suitable ports or apertures above the stream of returning oil for the controlled intake of sufficient oil from the tank to replenish the amount consumed by the burner system, the same apertures serving as air vents for the escape of entrapped air to the outside tank. Since the amount of oil flowing from the tank into the flow-control device is relatively small :in comparison to the amount in circulation, and since the flow into the device is at a low velocity and the suction line will not appreciably disturb the adjacent oil in. the tank, the addition of sludge through the intake ports will be practically nil. The same intake ports also provide an expeditious means for venting any entrapped air in the circulatory return pipe as the returned oil flows through said device to the feed pipe. It is therefore found that the desired functions set forth are satisfactorily fulfilled and the object of the invention is satisfactorily obtained by said device.

This invention was conceived and developed through practical experience incident with the installation and servicing of such fuel oil supply tanks and operative apparatus in household and other commercial heating systems. In the usual or prevailing systems of the type of heating systems thus described, it is found that much dialiculty and annoyance is often experienced by household and other clients in maintaining proper uniform heating service, particularly when cruder or heavier grades of fuel oil is being used, also immediately after such supply tanks have been filled before the turbidity due to sludge has been abated by its settling to the bottom. This sludge when circulated through the filters soon clogs them up and also the pumping system as well as the pipes. Such frequent failures of the pumping system and other operative apparatus to function satisfactorily necessitate frequent service calls requiring the services of a skilled mechanic to clean out the system and repair any mechanical damage resulting from such malfunctioning of the heating system. Such service calls are not only an additional expense in maintenance of the system, but are also a source of fire hazards and even possible explosions endangering life and property, all due to failure or improper functioning of the supply system.

It is conservatively estimated that at least 50% of the entire maintenance costs and service cost of operation is due directly to the accumulation of sludge and other foreign matter from the fuel oil clogging up the pipes, filters, and pumping system, thus interrupting service to the burner system.

Thefinstant invention is designed to prevent such unnecessary trouble and expense to the householder or other industrial plant using fuel oil for its source of heat, simply by eliminating excessive mixtures of sludge and other impurities and contaminants from the circulatory system, while at the same time purging any entrapped air from the circulatory system as it is returned through the return pipe to said control device. By thus eliminating most of the sludge from the circulatory system, the remaining maintenance services required will belong mainly to a purely mechanical category.

It will be obvious that such novel invention serves many a useful and highly desirable purpose, such as freedom from unnecessary annoyance due to improper functioning or failure thereof, wasted time and discomfort, overheating and its accompanying excitement due to motor and pumping stoppage, and possible fire hazards, in addition to enormous and unnecessary expense in service and maintenance costs. The frequency of such malfunctioning and the resulting unnecessary expense in the maintenance of this common type two-pipe supply and return systems demands every effort to reduce to a minimum, and the instant invention is the answer and solution of such maintenance problems. The flow-control device forming the invention can be installed in such fuel supply tanks at a minimal cost and is found to satisfactorily perform the proper functioning of the fuel supply system contemplated and set forth in the objects sought.

The desired requirements are found to be satisfactorily fulfilled by slightly different variations in construction of th flow-control device and there is no doubt that other slight variations in construction could be adopted without affecting the basic principle of operation, which is to connect the device with the ends of the feed and return pipes so that it effects a continuous flow-control of the previously circulated and filtered oil in the circulatory system without any mixing with the unfiltered contents of the supply tank after the first supply for the circulatory system, by admitting to the system only sufficient amouns of uncirculated oil from the tank to supply that lost to the fuel burner system, while venting any air entrapped in the system to the tank as it passes through said control device. The construction and operation of the device and its several embodiments will become more obvious from the appended drawings and the detailed description that follows:

Three separate embodiments of the invention are disclosed, as well as one modification of one embodiment, as will appear in the appended drawings and described in detail below, wherein:

FIGURE 1 represents an overall schematic view of a standard type two-pipe supply and return fuel oil tank and pumping system in which one embodiment of the novel flow-control device of this invention is installed;

FIGURE 2 is an enlarged side sectional elevation taken on line 22 of FIGURE 1;

FIGURE 3 is a sectional elevation taken on line 3-3 of FIGURE 2;

FIGURE 4 represents an enlarged sectional elevation of a second embodiment of the invention for installation in a tank as indicated in FIGURE 1;

FIGURE 5 is an enlarged side elevation of a third embodiment of the invention equally suitable for installation in a tank as shown in FIGURE 1; and

FIGURE 6 represents a slight modification in side elevation of the embodiment shown in FIGURE 1.

In the detailed description which follows, similar reference characters indicate corresponding parts throughout the several figures of the drawings, wherein,

FIGURE 1 represents a fuel oil supply tank 8, installed beneath the ground surface 6, and provided with vent 7, said tank being provided with a standard two-pipe circulatory system, the supply or feed pipe indicated by reference 9 and the return pipe by reference 5; said feed pipe 9 carrying fuel oil through filter or strainer 4 by motor and pumping system 2, to a nozzle 3 in a combustion casing 1 to supply fuel oil to a burner system not shown. All the forementioned apparatus is conventional and is shown only to clarify and illustrate the novel flow-control device 10 in its assembled relation and operative association with such fuel oil supply tank and with the two-pipe feed and return system.

While the flow-control device shown in enlarged detail in FIGURES 2 and 3 represents the same as that shown installed in FIGURE 1 and indicated by the numeral 10, it is to be understood that each of the embodiments illustrated in FIGURES 4, 5, indicated by references 14 and 15, respectively, are equally adapted for similar installation in FIGURE 1 to replace that shown at 10. The modification shown in FIGURE 6 is of course the same as that shown in FIGURE 1 with the slight modification in the position of the feed pipe 9a emerging from the lowermost surface of cylinder 16a and flush therewith.

FIGURE 2 shows in detail certain novel features of device 10 of FIGURE 1, which consists of three hollow tubular or cylindrical members, indicated by references 16, 17 and 18, disposed in integral assembly and providing free flow connecting passages therethrough, the respective longitudinal axis of each cylindrical member being so disposed that their projected axes are at right angles to each other, the lower and upper horizontal cylindrical members being in parallel planes, the vertical cylindrical member intercepting each horizontal cylinder normally at its mid-section and in open flow communication with one another. A baffle member 12 bisects the lower horizontal member and extends upward axially of the vertical cylindrical member to a distance well below the upper end thereof, thereby forming a fluid-tight partition in the lower horizontal cylindrical member and for a considerable distance in the vertical cylindrical member, thus forming a barrier to the straight flow of fluid from the return pipe 5 to the feed pipe 9, thereby imposing on the returning fluid from the return pipe 5 an upward deflecting course to clear the uppermost edge of said bafiie member, and whereby such abrupt deviation in the current will expedite the escape of entrapped air upwardly and through vents or intake ports 11 to the tank, such ports or apertures shown at 11 in the ends of the upper cylinder 18. By such imposition of baffle 12 escape of air upwardly through venting apertures 11 is expedited thereby in its escape to the tank. At the same time these intake ports or apertures are of such size and shape as to admit suflicient fuel oil from the tank to flow gently, and without appreciable disturbance to the surrounding liquid in the tank, into the flow-control device in such amount as to constantly replenish the amount of fuel oil consumed by the burner system during operation. Since the amount of fuel oil admitted to the flow-control device is relatively small in comparison to the amount returned through pipe 5, and since its flow is at relatively low velocity, the surrounding oil in the vicinity of the intake ports is practically quiescent and not appreciably affected by suction through the feed pipe, the small amount of sludge or other foreign matter entering through these intake ports will be practically negligible. The extended shields 13 at the ends of the upper horizontal cylinder overlying ports or apertures 11, indicated in FIGURE 3, are designed to prevent any unsettled sludge or other foreign matter from being directly drawn into the flow-control device, thus further avoiding undue contamination of the circulating oil in the system. The bafl'le member is designed to provide slight momentum to the downwardly directed current as it cataracts over the baflie into the outlet end of the lower cylinder 16 thereby affording a selfcleaning effect to dislodge any possible sludge or other sediment lodged in said device.

FIGURE 4, shows a second'embodiment of the flowcontrol device, indicated by the reference 14, which consists of but a single cylindrical member whose horizontal axis is vertically disposed wherein the feed or supply line 9 emerges from the bottom end of the cylindrical member while the return pipe 5' enters the cylindrical wall considerably above the lower end and at an acute angular position relative to the major axis of said cylindrical member, thereby preventing interference between the flowing oil from the return pipe 5 and the intake supply entering through ports 11 to join the circulatory system while at the same time the return flow is given a retarded swirling motion as it impacts against the adjacent inner walls, thus imparting a self-cleansing effect, while such impeding of its velocity of flow expedites the escape of entrapped air outwardly through venting ports 11'.

FIGURE 5 represents still a third embodiment of the flow-control device, which consists of a single, vertically disposed cylindrical member indicated by reference 15, with both the feed and return pipes connected with outlets through the lower end of said cylindrical member, as indicated by reference 9" and 5", respectively. At the upper end of said cylindrical member the intake ports or vents are shown at 11" in the configuration of the gable end of familiar sloping roofs, but the form of port is not of such magnitude that one could not be replaced by other forms that would give equally satisfactory service. The important point is that they be made of suflicient sectional area to admit sufiicient oil from the tank to keep replenished the amount consumed by the burner system. Whether these ports or apertures be of circular contour, V-shaped or elongated slots or triangular is 'a matter of choice and experimentation, and are therefore of comparatively little weight in the evaluation of the invention. -It will be observed that both feed and return pipes emerge at equal levels from the bottom of the cylinder. This arrangement is found to give satisfaction under usual conditions, and serves the practical purpose of functioning equally well regardless of which pipe is connected to which outlet, avoiding a possibility of error through negligence in installing the device in an oil supply tank. An additional possible advantage besides its simplicity of construction and operation is the greater space in the cylinder above the returning circulating oil from pipe 5" to provide more space for the escape of entrapped air above the circulating liquid oil.

FIGURE 6 represents a slight modification of the device shown in FIGURES 1-3, in that the end of cylinder 16a has the opening connected with the feed pipe 9a in the end at the level of the lowermost surface of the inner wall of said cylinder and flush therewith, thereby avoiding the remote possibility of lodgement of sludge or other foreign matter entrapped in the space below the outlet level in FIGURE 1. Otherwise, the device is the same as that disclosed in FIGURES 1-3.

I claim:

1. For use with a fuel oil tank of the standard type two-pipe feed or supply and return pipes for a fuel oil burner system comprising a circulatory system which depends for its operation on a pumping system for taking up fuel oil in measured amounts from such tank and delivering such amount-s through a filter system to a fuel burner system, wherein only a relatively small portion of the circulating oil is consumed by said burner system in any unit of time while the remainder is returned through said return pipe to the tank: a sludgeeliminating, air-venting, flow-control device for installation in said fuel tank and operatively connected with the respective ends of the said feed and return pipes to effect a continuous open circulatory system without direct mixing of the returning pre-circulated oil with the entire contents of the tank, said flow-control device comprising a hollow, oblong body or casing of predtermined shape and size having a major axis disposed substantially vertically relative to the level of said tank, said hollow body being operatively connected through openings in the vicinity of its bottom or lowermost end with said feed and return pipes in open communication therewith, thereby effecting an open, continuous flow passage between said pipes without mingling with the entire contents of the tank, the outlet opening of said device connected with the feed pipe being positioned at least at as low a level as the opening through which the return pipe is connected, the uppermost end of said device being provided with relatively small openings or apertures of predetermined size and form as will admit such limited amounts of oil from said tank as will keep replenished the amount of oil consumed by the burner system during operation, said apertures also providing vent means for the escape of entrapped air returning through said return pipe to said device, whereby the device provides for the eliminating of practically all sludge and other impurities from the circulatory system except the small amount which might find its way through the intake apertures, while at the same time purging the system of any entrapped air therein.

2. The invention described in claim 1, wherein said oblong, vertically disposed hollow body comprising said flow-control device consists of a hollow, vertically disposed cylindrical body or member terminating at its lower and upper ends in, and rigidly connected in open flow relation with, a hollow, horizontally disposed cylindrical member at the mid-section thereof, each cylinder being disposed at right angles with the other two cylindrical members, the said feed and return pipes being operatively connected through openings through the top wall of said lower horizontal cylindrical member adjacent the respective ends thereof, thereby forming an open continuous passage through said flow-control device whereby fluid oil returning from the return pipe is directed to the feed pipe without mixing with the main body of oil in said tank, a vertically disposed baffle member bisecting said lower horizontally disposed cylindrical member transversely of its major axis and extending upwardly into and axially of said vertically disposed cylindrical member for a distance well below the opening into said upper horizontally disposed cylindrical member, said bafiie member thereby separating the lower cylindrical member and the vertically disposed member for some distance into separate chambers, whereby the oil entering from the return pipe is deflected upwardly to clear the upper edge of said baflie member on itsway to the feed pipe, the ends of said upper, horizontally disposed cylindrical member being provided with relatively small ports or apertures of predetermined size and shape which serve the double function of venting entrapped air from the return pipe to the outside tank, while admitting uncirculated oil from the tank in limited but sufiicient amounts to replenish the supply in "the circulatory system consumed by the burner system during operation.

3. The invention described in claim 1, wherein the vertically disposed hollow body comprising the flow-control device consists of a single cylindrical member, said cylindrical member provided through its lower end with two openings operatively connected with the feed and return pipes, respectively, and at the same level, thereby affording an uninterrupted straight flow connecting the two pipes without mixing with the mass of oil in said tank, said cylindrical, vertically disposed body being provided with openings or apertures of predetermined size and shape in its upper end, which openings serve the dual purpose of venting entrapped air entering through the return pipe to the outside, and at the same time serving as intake ports for the admission of oil from the tank in such limited amounts as to replenish the oil in the circulatory system consumed by the burner system during operation.

4. The invention described in claim 1, wherein the vertically disposed oblong body comprising the flow-control device consists of a single hollow cylindrical member, said member provided through its lower end with an outlet opening operatively connected with the feed pipe, and another opening through its lateral wall at a considerable distance above the said lower end, the axial line of the return pipe being oriented at an acute angle to the longitudinal axis of said vertical cylinder, whereby the inflowing oil through said return pipe is deflected in the direction of the side wall of said cylindrical member and given a sort of deflected swirling motion on its way downward to the outlet through the feed pipe, such swirling flow imposed on the stream of returning oil serving as a selfcleaner function for the inside wall of the device, while permitting and expediting the venting of entrapped air from the return pipe, the upper end of said cylindrical member being provided with openings or apertures of suflicient size and of predetermined shape to admit oil from the outside tank in limited but sufficient amounts to replenish the oil consumed by the burner system during operation, said apertures also serving at the same time as vents for the escape of entrapped air from the circulatory system.

5. The invention described in claim 1, wherein the oblong, vertically disposed hollow body comprising the flow-control device consists of a vertically disposed hollow cylindrical member, the opposite lower and upper ends thereof being rigidly connected in open flow relation to horizontally disposed open cylindrical members at their mid-sections, said horizontally disposed cylindrical members in parallel planes and their major axes being at right angles to each other, and the longitudinal axi of said vertically disposed cylindrical member being normally disposed to the axes of said horizontally disposed members, the upper wall of said lower horizontal cylindrical member near one end having an inlet opening operatively connecting the return pipe with said device, an opening through its opposite end through which the feed pipe is operatively connected, said opening for the feed pipe being through the end of said horizontal cylindrical member and flush with the lowermost Wall thereof, thereby eliminating the possibility of becoming a trap for the accumulation of sludge or other foreign matter lodging therein, the ends of said upper horizontally disposed cylindrical member being provided with openings or apertures of predetermined size and shape to admit limited amounts of fuel oil from the tank into the device in suflicient quantity to replenish the amount of oil consumed by the burner system during operation, and at the same time venting any entrapped air from the return pipe to the outside tank.

References Cited UNITED STATES PATENTS 11/1881 Shetter l76 7/1926 Kirchhan l37-247.27

US. Cl. X.R. 1375

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