US2209649A

US2209649A - Oil burner

Info

Publication number: US2209649A
Application number: US210265A
Authority: US
Inventors: Frankland William Howard
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-05-26
Filing date: 1938-05-26
Publication date: 1940-07-30
Anticipated expiration: 1957-07-30

Description

July 30, 1940- w. H. FRANKLAND OIL BURNER Filed May 26, 1958 gwum vhw Wfi fiankland Patented July 30, 1940 UNITED STATES PATENT OFFICE- 4 Claims.

This invention relates to oil burners in general, and more particularly to oil burners installed in radiant heaters of a type used in the heating of. small homes and apartments.

One of the most efflcient types of these oil burning heaters includes a vertical heat radiating combustion chamber enclosed in a casing and in communication with an oil containing receptacleat its lower end. A down draft tube depending from the top of the chamber coaxial with said receptacle and terminating a short distance from the upper end thereof, serves to spread the flame resulting from the burning of the oil in said receptacle and to provide the air necessary to ensure complete combustion of gases generated by the burning oil. Even with this eiilcient type of burner, it has been found that the starting operation can be greatly accelerated by arranging a starting tube concentric with the down draft tube and extending through the opening in the oil receptacle to a short distance above the surface of the oil in the bottom of the oil receptacle.

It has been customary in starting these heaters,

without the use of a starting tube, to open the door with which the combustion chamber is provided and drop lighted matches, one after another, onto the oil in the oil receptacle until the oil becomes ignited and the flame spreads into the combustion chamber. This operation is time consuming and has a tendency to form carbon within the oil receptacle during the period required by the matches to heat the air and oil vapor within the receptacle to its flash point,

or to the temperature at which this mixture of air and oil vapor burns continuously.

It is the primary object of this invention to provide the type of heater just referred to with means whereby the oil in the receptacle may be caused to ignite a great deal more readily than has been possible heretofore; and thereby to eliminate practically all possibility i of forming carbon in the oil receptacle.

Other objects of the invention will become apparent as the detailed description thereof proceeds.

In the drawing:

Figure 1 is a central vertical section through a down draft oil-burning heater provided with the starting tube which forms an essential element of the present invention;

Figure 2 is a horizontal section, taken on the line 2-2 of Figure 1; and

Figure 3 is a fragmentary section showing a 5 modified form of the invention.

As shown in the drawing, the invention comprises a casing 4, which may be more or less ornamental, provided with a top 5 having apertures 6 through which heated air escapes into a room or apartment to be heated. The casing 4, 5 provided with a bottom I, is. mounted on a base 8, part of which is cut away to form a recess 9 through which air may be drawn for the purpose of ensuring combustion of the fuel oil in the heater. The casing 4 has one wall thereof 10 provided with a door in which may be swung about its hinges H to give access to a heat radiating combustion chamber I! mounted concentrically within the casing 4.

The heat radiating chamber l2, closed at its 15 lower end by a bottom l3 and at its upper end by a cover I4, is supported on the upper end of an outer receptacle l5, within which is mounted an oil-receiving receptacle it connected to a perforated cylindrical shell H. The bottom 1 of 20 the casing 4 and the bottom of the outer receptacle 15, are provided with registering apertures i8 and 69, respectively, to provide a passage for the air necessary to ensure combustion of oil in the receptacle IE. 5

The bottom i3 is provided with an upturned nozzle 20 for the oil vapor undergoing combustion. A down draft tube 2|, suspended from the top H of the combustion chamber l2 coaxial with the shell l1 and the nozzle 20, terminates 30 a short distance above the upper end of said nozzle 20, and has its lower end provided with a series of apertures 22 through which air may be drawn to spread the flame issuing from the nozzle 20. A flue 23, extending through a wall of 35 the combustion chamber i2 and the outer casing 4, conducts the exhaust products of comlligstion away from the heat radiating chamber The open upper end of the down draft tube 2| extends through the cover H. The starter tube 24 extends coaxially with the down draft tube 2! through the combustion chamber 12 and through the shell ll to a point slightly above the pool P of oil introduced into the receptacle for the purpose of starting the heater in operation. The starter tube 24 is adjustably supported, preferably by friction fit, in an apertured spider 25 suitably secured to the top H of the combustion chamber !2; and a cap 26 is detachably secured 50 to the upper end of the starter tube 24 to close the same after the burner has been properly set in operation.

It is not absolut ly necessary that this starter tube 24 should extend through the down draft tube 26. A substantial equivalent of the tube 24 comprises a tube 2? extending through the casings 4 and I2 and bent to form a branch 28 extending downwardly and concentrically through the nozzle 20 to a point close to the surface of the pool of oil introduced into the receptacle l6 for starting purposes through a valvecontrolled pipe 29. The outer end of the tube 2? may be provided with a suitable closure valve as to cut off the supply of air after the oil in the burner has been properly ignited. The wall of the chamber l2 opposite to the door it of the outer casing i is also provided with a door 38 through which matches or the like may be introduced or thrown through the nozzle 2@ for the purpose of igniting the oil within the oil'receptacle E6.

' Without the starter tube, it is usually necessary to throw four or five matches into the burner receptacle before the fuel oil vapor becomes ignited. Fuel oil, when admitted first to the bottom of the burner, forms a shallow layer, or pool. It is believed that the difficulty -of ignition is due to the fact that the atmosphere close to the surface of the oil is diluted by oil vapor and lacks suflicient oxygen to start ignition of the vapor. By providing a starter tube in communication at one end with the atmosphere and having its other end close to the surface of the fuel oil, it has been found that the first match thrown into the burner usually starts ignition of the fuel oil. This quick starting naturally prevents formation of carbon within theburner and adds to the effectiveness of the heater as a whole. Just as soon as ignition has begun, the cap on the outer end of the starter should be closed, because the down draft tube supplies all the air necessary to spread the flame and ensure complete combustion.

The burner, including the liquid oil receptacle l6 and the apertured shell iii, are of standard construction in many modern fuel oil heaters; and is a type of burner used to some degree in practically all fuel oil heaters manufactured and sold at the present time. This burner is very efficient and produces a clean and carbonless flame; but, as is the case with all such burners, it is very slow and diflicult to light. The air holes in the shell I! are designed to allow only sufllcient air to enter the burner and mix with the oil gases when the burner is hot and properly operating as a heater. However, these air holes are not sufiicient to permit the necessary amount of air to come in contact with the starting supply of liquid oil in the receptacle part of the burner to ensure quick starting. If these holes were sufficient in size and number to make the burner easy to light, they would keep the burner from operating effectively when the burner becomes hot, and would cause a very hard carbon due to excess of air in the burner.

It will be noted, from Figure 1 of the drawing, that the bottom row of holes in the shell I 'I is located above the top ofthe receptacle l6 and above the inlet end of the tube 2|. This arrangement is necessary because the underwriters require that the liquid fuel receptacle be of such depth as to provide a certain liquid level which is determined by the usual float valve control with which all fuel oil heaters are provided and which automatically cut off the flow of oil into the receptacle in case the heater is turned on and not lighted. In consequence of this construction' of the modern oil heater, the atmosphere close to the surface of the normal starting supply of liquid oil in the receptacle I6 becomes diluted with oil vapor and lacks sufficient oxygen to start ready ignition. By arranging the starter tube with its inner end below the lowermost row of apertures in the shell ll, oxygen from the atmosphere is brought down close to the surface of the normal starting supply of liquid fuel in the receptacle.

The draft of the flue to which the stove is attached causes a suction of air, whether the heater is lighted or not, and this suction draws the air down the starter tube, when opened at its outer end, onto the starting supply of liquid oil at the surface thereof. When the oil is lighted, this tube provides a sufficient amount of oxygen to ensure quick lighting at a point close to the surface of the normal starting supply of liquid fuel, which is not present in the modern type burners now used. The rush of air down the starter tube fans the flame, resulting from the throwing of a lighted match onto the liquid fuel, into a very hot flre which causes the burner to become hot enough within a period of a minute and one half to two minutes to effect theichange of the oil into gas, a process which ordinarily takes from :welve to twenty minutes in burners of the usual ype.

While the starter tube is shown in Figure 1 of the drawing as passing through the down draft tube of the heater, it has no effect whatever on the operation of this down draft tube. The sole purpose of the present invention is to provide a tube adapted to be suitably mounted on a standard radiant oil heater so as to decrease materially the time required for starting the heater into operation.

While I have illustrated the apparatus for carrying out this method as embodied in a par-' ticular form, it is to be understood that it is not to be considered as limited to that form or in any other manner except as indicated by the scope of the claims appended hereto.

What I claim is:

1. Radiant heater including in combination, a casing open to atmosphere, means within said casing and spaced therefrom forming a radiating chamber, a pot-type burner within said casing having an open top in communication with said radiating chamber, said burner being provided with lateral air passages communicating with said casing, and being provided with a liquid fuel inlet adjacent its bottom, a down draft pipe extending into said radiating chamber and opening within said casing, and having its lower open end terminating adjacent to but above the top of said burner, and a starting air tube having its upper end open to atmosphere, having its lower portion extending into said burner coaxially with said down draft pipe, and having its lower open end terminating below said lateral air passages and adjacent the bottom of said burner.

2. In combination, a liquid fuel heater having means forming a radiating chamber, and an oil burner below said radiating chamber with a partition therebetween having a narrow throat affording communication between said oil burner and said radiating chamber;- said oil burner including a receptacle adapted to contain a normal starting supply of fuel oil, and having a surrounding shield defining a precombustion space above said receptacle, a starting tube extending through said radiating chamber into said precombustion space and terminating slightly above the plane of the normal oil level in said receptacle, the other end of said starting tube being in communication with atmosphere. a closure for said last mentioned end, the starting tube having its inner end portion exposed to the precombustion space and the adjacent portion oi. said radiating chamber, and means within said radiating chamber shielding the upper portion of said starting tube.

3. Liquid fuel heater as claimed in claim 2, said shielding means comprising a tube terminating above said throat and open at its opposite end to atmosphere, constituting the air tube for supplying air for normal combustion after starting.

4. Liquid fuel heater as claimed in claim 2, 5 and including means for adjusting said starting tube toward and from the surface of thestarting supply 01' fuel oil.

WILLIAM HOWARD FRANKLAND.