US2254864A - Fuel burning heater - Google Patents

Description

p 1941- G.-L. WELSTE AD $254,864

FUEL BURNING HEATE Filed Oct. 13, 1939 Y WELSTEHD Patented Sept. 2, 1941 UNITED STATES mmcan;

FUEL BURNING HEATER Guy L. Welstead, Dixon, 111. Application October 18, 1939, Serial No. 299,257

2 Claims. (01. 126-360) The present invention relates to fuel burning heating apparatus, and more particularly to oil burning heaters for water tanks and the like.

It is an object of the invention to provide an improved oil burning heater, simple, yet compact in construction, eflloient and reliable in performance, and easy to operate and control.

Other objectsinclude the provision of an oil burner that starts easily, that induces its own draft, that generates its own blast in its flame,

that holds its flre in a strong wind and that resists the tendency of down currents near buildings, etc. vision of ,a burner that gives complete burning of cheap low grade fuel oils and wast engine oil, and yet is easy to start and simple to regulate.

Still another object is to make a highly efllcient heater so that it can be kept a small size, so as to take up little space in a water'tank, be light enough for easy handling and installation and to displace so little water in a tank as to submerge by its own weight.

These and other advantages will appear from the following description of one particular embodiment of the invention. The invention resides in certain features of construction, combination of elements and arrangements and proportions of parts, as will be hereinafter particularly pointed out. In the drawing:

Fig. 1 illustrates partly in side elevation and partly in section, a heater constructed according to my invention and particularly suitable for heating watering tanks for live stock;

from reversing its draft, and the pro-.

thereunder, and they are given a small section at 22 where they are welded to the flame pipe to minimize the conduction of heat through the bars2ll to the supporting surface. The particular supporting bars shown are proportioned to properly support the heater in a tank of water or to support it when the heater is used to dry out sand and-the like. But when the device is used to heat a building or similar space the flame pipe in should be supported much higher oil the floor. My heater is constructed of heavy gauge steel pipe and has sufficient weight to hold itself submerged in a water tank, but the supporting bars 20 provide convenient projections overwhlch rocks or other weights or fastenings may be placed for additional security against accidental upset.

An iron burner cup 24, only slightly smaller in diameter than the pipe I2, is welded to a rod 28 and suspended in the pipe thereby from a cross bar 28 laid loose across the top of the pipe l2. A wing nut 30 threaded on the upper end Fig. 2 is an end elevation partly in section of p the same heater; and, v

.F'ig. 3 is an enlarged perspective view partly cut away of the burner cup of the heater of Figs. 1 and 2.

of the rod 26 supports the cup 24 and permits an easy adjustment of its height with respect to the opening into the flame pipe Ill. The cross bar 28, being loose, can be shifted to space the suspended cup 24 from the walls of the pipe l2.

The burner. cup 24 itself is shown best in the enlarged and partially cut away view of Fig. 3. A. flat plate 32 is welded to the bottom of a cylindrical ring 84 and a series of holes 36 are provided below the rim of the cup to aid the burning of the fuel. A wick 38 of asbestos rope ls'laid in a spiral to cover the bottom of the cup, although. very little wick is actually required.

A shelf 40 welded to the exhaust stack supports a fuel tank 42. From this tank a fuel pipe 44 leads to the top of the feed pipe l2 and terminates The particular heating device shown in the drawing ismade of several lengths of heavy steel pipe welded together. A horizontal flame pipe ID has a vertical inlet pipe or feed pipe l2 opening into it at one end. The exhaust flues extending from the other end of the flamepipe it include vertical .and horizontal bame pipes l4 and I8 and avertical stack it. These pipes are all welded together as shown in the drawing to provide a single continuous flue extending down the feed pipe i2, through the flame pipel0, through baille pipes l4 and i6 and up the stack l8.

A pair of cross bars 20 welded to the bottom ofthe flame pipe it) provide a supporting base for the entire structure. These bars support the flame pipe ill just far enough of! the bottom of a water tank to permit good circulation of water in a downwardly bent portion near the center of pipe l2 to drip oil into the burner cup 24. A valve cook 46 regulates the flow.

To put the heater into operation, th burner cup 24 is lifted out. Its wick 38' is wet with oil and lighted. Then the flaming cup is reinserted in the feed pipe l2 and the wing nut 30 is turned up'to lower the cup 24 to the bottom of the pipe. The draft starts most easily when the burner cup 24 is thus lowered. A slight breeze-will often create sufllcient suction on the stack It to start a draft in the right direction to pull the flame through the flame pipe ill, but the operator can path down around on the cup 24.

.the burner builds up a strong blast-like flow of air down past the cup 24 that whips the flame and produces a roar that can be heard in some instances several hundred feet from the burner.

I do not understand the reason for the occurrence of the strong blast but I am confldent that the blast is responsible for the strong flame andthorough combustion of my burner and its resulting highly emclnt operation. Thus I have found that with the cup 24 in its lowermost position, little or no blast is produced and the flame burns yellow and smoky, but that with the cup 24 raised to somewhat constrict the entrance to the flame pipe III, the blast builds up quickly and produces a strong blue flame with a soot-less and practically colorless exhaust. The blast invariably accompanies the eflicient burning of the fuel and so conveniently serves as the criteria of a good operating adjustment of the position of the burner cup 24, and accordingly the best position for the burner cup can be determined quickly by trial. After the flame and the draft have been started (with the cup 24 in its lowermost position) the cup may be lifted by hand and adjusted by trial to the position giving the best draft. Then the wing nut 30 can be turned down to support the cup there. In such a case the cup 24 should be lowered to weaken the selfgenerated blast effect of the flame. The adjustment is not critical because the cup 24 will hold its flame in a much stronger blast than that required for thorough burning of the fuel. At times it is advantageous to move the cup 24- away from the center of the feed pipe I2 towards the flame pipe It, by moving the supporting cross bar 28, so as to slightly close the passageway on that side of the cup. Apparently the resulting restriction on the right hand side of the cup 24 as viewed in Fig. 1 tends to compensate for the longer flow the left side.

The intensity of the flame and the rate of heating are controlled by adjusting the opening of the fuel valve 46 to regulate the rate at which the oil drips into the cup 24. The heater develops a good blast and operates efliciently over a wide range of fuel feeding rates, but if the oil is fed too fast the flame begins to burn sooty although it continues to generate a blast. The presence of the soot, of course, indicates incomplete combustion resulting from overloading the burner. As long as this overloading is avoided, the blast and the flame apparently act to keep the cup 24 practically dry because then a change in the setting of the fuel valve 46 produces a prompt corresponding change in the intensity of the flame. Also the wick apparently is unnecessary except for starting. and in some cases I have found burners operating satisfactorily with no wick at all but with only a coating of soot A serious operating'difliculty with burners of I this general type has been the occurrence of back drafts or reversed drafts. Such a condition obtains when the draft becomes established in the wrong direction and carries the flame out the inlet or air-feeding passages. Such V drafts on the lee-sides of reverse drafts are commonly caused by sudden and temporary wind disturbances such as down buildings. In burner of Fig. is reversed draft not only dostroys the blast action and produces a smoky flame, but also directs the flame up the feed pipe I2 and carries most of the heat out into the atfnosphere.

I have found that the use of such as I4 and II,

obstruction pipes, providing abrupt corners in the flue passage tends to obstruct the flow of air through the flues and effectively prevents gusts of wind from reversing the draft. I have further found that this construction also reduces the effect of those other gusts that tend to increase the draft and so reduces-their tendency to produce a temporary excessive draft that might pull the flre out." And I have still further determined that the obstruction offered by the obstruction pipes I4 and I4 slows the normal draft of the burner and produces two additional eifects: first, the burner is more stable in operation because it is afl'ected less by changes in wind intensities; and second, the burned gases give up their heat more effectively as a result both ofthe slower flow of gases and of their impact against the walls of the obstruction pipes l4 and I8 and the stack l8.

Not only have I found that all these desirable eflects result from the use of these obstruction pipes, but I have found also that there is a best size and proportion for these pipes so that their effect may appear in the correct amount. Too muchobstruction to the draft makes the draft sluggish so that the burner is hard to start, and in extreme cases, it may even impair the blast effect and so cause incomplete combustion. A flue that is too open, that is, has too little obstruction, leaves a draft too sensitive to wind changes, and too likely to be blown out or reversed by sudden gusts and down drafts. I have experimented with a large number of sizes,

' shapes, and proportions of burners, and I have is twenty-five inches found that the shape and proportions shown in the drawing give the best balance between openness of flue and the bathing effect. These proportions are not extremely critical, but should be maintained substantially as shown if the best results are to be obtained. For example, the drawing is proportioned to show pipes with a flve inch external diameter. Thus the length of the flame pipe I ll measured along its center line and the obstruction pipes l4 and [6 measured along their center lines are nine and sixteen inches respectively. A reduction of these obstruction pipes l4 and II to half of these lengths would make the burner much more sensitive to gusts and sudden down drafts, and an increase to twice these lengths would make the draft more sluggish and the starting of the flame more diiflcult. A reduction of the pipe size to four inches, without any other change in dimensions would reduce the heating capacity of the burner and make starting a little less easy, but nevertheless would leave the burner with a good draft performance. A further reduction to a three inch diameter would make the draft slu'ggish and very diflicult to start. An increase in the diameter from flve to six inches would not materially change the draft characteristics. Of course, when it is desirable to use a small diameter pipe in a particular installation the other dimensions may also be reduced the proper amounts to give the device the desired balance between openness of flue and the baiiiing effect.

Natura1ly,"a long narrow passage tends to "pocke cold air and so make starting dimcult,

easy tostart and convenient tov operate. It is adjustable over a wide range to accommodate and in general either increasing the diameter or reducing the length will make starting easier.

I have found it best to use a burner of the proportions shown for practically all stock tank installations, and to provide extension stacks or other artiflces where down drafts have been unusually strong and troublesome, as by extending the stack above the roof of nearby buildings. In fact my construction has proven so eilfectivev that conventional "dampers of the butterfly valve type are never necessary, and actually when such dampers have been installed in ex-' tension stacks the users of my heaters have 7 always operated those dampers in fully open position. .The adiustment'of the position of the flame cup 24 not only provides all the'regulatlon necessary for obtaining the best operation of the heater, but apparently also provides, in cooperation with my flue construction, an adjustment of the flue obstruction et cetera, over a wide enough variation and within the proper.range of valves to meet the requirements of most wind conditions and the like.

The closely spaced abrupt turns in the flue of my burner are particularly eflective for protecting the flre against disturbing wind conditions (because they impose a greater check on disturbances from gusts and sudden wind changes than they impose on the starting of the draft and its normal steady flow. Thus a straight flue designed to provide the same ease of starting and normal draft would provide less protection against gusts and down drafts.

I have found that my oil burning heater is highly efllcient in operation and that itrequires less fuel than competing devices or other known diflerent wind conditions. It resists wind disturbances, and burns clean and heats effectively in spite of changing or gusty wind conditions.

It'is simple in construction and having nothing to get out of order, is dependable in operation. It will be apparent to those skilled in the art that my invention is not limited to the speciflc embodiment herein illustrated and described by way of example, but that it is capable of numerous modifications and variations and is to be limited only within the scope of the appended claims.

I claim:

lain combination, n down draft flue, opening I at its bottom into another flue extending laterally out the side thereof, a flame cup in said down draft flue, adjustable suspension means for supporting it therein near the opening and for ..adjusting it up and down between a position said down draft flue to reduce the obstruction,-

alongside said side opening and a point thereabove, said cup being of such size and construction that when raised above said outlet opening it offers considerable obstruction to flow of gas down said flue, but when lowered it uncovers at least a part of said opening out the side of and means for maintaining a flame on top of said flame cup.

2. In combination, a down-draft flue. a flame generator obstructing the flue but providing substantial down draft flame passages all around said flame generator, means for dripping. liquid fuel on the top of said flame generator, a flame chamber opening out the side of said down draft.

flue, means for adiustably supporting said flame generator centered in said flue near said opening,

generator.

whereby the flame generator maybe adjusted up and down to cover and uncover said opening out the side of said down draft flue and may be brought thereby to the position at which the flame burns with a strong blast and whereby also the spattered and atomized fuel rebounding from the top of said flame generator is caught by the down draft on all sides of said flame our r.

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