US2039790A - Method and apparatus for burning oil - Google Patents

Description

May 5, 1936. 'c. A. FRENCH 2,039,790

METHOD AND APPARATUS FOR BURNING OIL Filed Oct. 14, 1929 E9 2. PM

IIHIIO Patented May 5, 1936 METHOD AND APPARATUS FOR BURNING OIL Charles A. French, Riverside, Ill.

Application October 14, 1929, Serial No. 399,685

6 Claims. (Cl. 158-53) This invention relates to a method of and apparatus for operating oil burning devices particularly designed for the utilization of heavy oils. More particularly the invention relates to a method of and an apparatus for initiating and continuing the vaporization and combustion of oil.

The principal object of the invention is to devise a method of and apparatus for initiating and 10 maintaining the combustion of oils, particularly the heavier grades.

Another object is to initially vaporize the oil by one method and to subsequently and automatically vaporize the oil by another method.

These objects and others, which will be apparent from the detailed description to follow, are obtained by initially vaporizing the oil by partial combustion and subsequently carrying on the vaporization by the utilization of sensible heat 30 from a portion of the gaseous products of complete combustion.

Inasmuch as hydro-carbons apparently burn only from the molecule, it is probably impossible for them to burn in any but the vapor or gaseous 25 state. It follows that, to produce the blue flame of complete combustion, it is necessary that the fuel shall bein the vapor or gas state and mixed with air in or very nearly in the combining ratio. However, the vaporization of so heavy hydro-carbons has presented many difficulties, the major one being the tendency of the oil to decompose, forming residues of tar and coke.

In the so called atmospheric type of burner, 35 such as the conventional plumbers torch, the fuel is boiled under pressure in a closed retort. This method of vaporization does not differ materially from the common method of cracking heavy hydro-carbons into light oils, tar and coke. 40 In practice. such a vaporizer becomes filled with tar and coke just as do the common oil stills. In the hot spot type of burner, the liquid fuel is spread upon a surface heated to a temperature high enough so that the liquid particles do not 45 wet it. The liquid particles assume spherical form and are kept from contact with the hot surface by the vapor formed underneath them. A vigorous current of air scrubs over the heated surface, removing the vapors as fast as they are 50 formed. This method provides a fairly satisfactory form of vaporization.

In the method and apparatus of my invention, I propose to vaporize the oil by sensible heat from portions of the oil undergoing combustion. 55 .In a process of this nature, it is obviously necessary to initiate the vaporization by some other method. In my invention this problem is taken care of in such a way that the starting means is automatically cut off when the burner becomes heated suillciently for complete combustion. This 5 is accomplished by distributing the oil in a vaporization chamber in a finely divided form, or a thin sheet, such as from a high pressure spray, or from a rotating disk, and igniting it by a spark or otherwise. 10

There will be a sufllcient amount of certain constituents of the oil vaporized by the spray to maintain partial combustion, for which a requisite amount of air is supplied. The partial combustion products and any liquid fuel vaporized by 15 the heat developed are mixed with air for complete combustion and supplied to the main burner. The source of air to the main combustion burner is adapted to draw a current of gases from the flame side of the burner through the vaporization chamber. It will thus be seen that as soon as ignition and complete combustion is brought about at the main burner, the gases which are drawn through the vaporization chamber are inert, thus stopping the partial combustion in said chamber. Thereafter, vaporization is carried on by direct contact with the portion of the hot combustion gases which is conducted through the vaporization chamber.

In the drawing:

Figure 1 is a diagrammatic view showing one form of apparatus embodying my invention; and,

Fi ure 2 is a similar view of a modification.

In the drawing, Figure l, a vaporization chamber l houses a rotating disk 2 for distributing oil in a finely divided form. The disk 2 is mounted on a hollow shaft 3 adapted to rotate the disk and to supply oil thereto. A plurality of small openings l at the bottom of the shaft 3 adjacent the disk serve to distribute oil thereto. The shaft 3 extends through the top of the vaporization chamber and is provided with an oil supply pipe 5 controlled by a valve 8. Means are also provided for driving the shaft, such as .the pulley I, diagrammatically indicated. A cylindrical intake throat 8 communicates with the flame side of a burner 9. The burner has a grating ID lying substantially in a horizontal plane and a. conical, upwardly extending grating H at the center thereof. Said gratings constitute discharging means for gases to be burned. The intake throat 8 communicates with the conical portion of the grating. At the upper end the intake throat 8 is provided with an outwardly extending cone-like shield I! which surrounds the disk 2 in close proximity thereto. The bottom of the vaporization chamber I has a downwardly depending, cylindrical baiile l3 spaced from the intake throat 3 to form an annular passage therebetween. A cylindrical casing member l4, concentric with respect to the baffle l3 and spaced therefrom. is attached to the vaporization chamber and Joins the intake throat at the bottom. A small opening i5 is provided adjacent the grating Ii as a firing opening, as will be hereinafter described. A pipe l6 communicates with the casing member i4 and with a Venturi-like throat I! in a fan intake pipe iii. The fan-intake i6 is provided with a valve IS. A fan 20, with which the intake i3 communicates, is adapted to draw gases through the pipe i6 and air from the atmosphere through the inlet l8 and deliver them to the burner gratings Ill and II. A spark plug 2i provided with a source of current, not shown, extends through the vaporization chamber into the path of the oil being distributed by the disk 2. It will be noted that said disk has a slight upwardly turned flange 22 at the edge and that the shield i2 extends upwardly above the path which will ordinarily be followed by oil being distributed from the disk at its normal rate of operation.

The modification shown in Figure 2 is similar in general design to that shown in Figure 1, which has been described in detail. but differs materially in the location of the component parts. In Figure 2, the burner grating 23 constituting discharging means for gases to be burned has a substantially horizontal portion and an inverted conical section 24. A casing member 26 joins the grating at the outer edge of the face of the horizontal portion and encloses all the other elements making up the burner.

A hollow shaft 26, connected at the top with a supply pipe 2! controlled by a valve 23, carries a distributing disk 29 at the lower end. Small openings 30 at the bottom of the shaft near the disk 29 serve to distribute the oil onto the disk. The shaft 26 also carries a centrifugal fan 3i attached to the shaft at a point spaced upwardly above the disk 23. v

A substantially horizontal bailie plate 32 fits around the shaft 26 in a fluid-tight manner and extends radially therefrom, being circular in shape. An inner casing member surrounding the baille 32 has a substantially horizontal upper portion 33 spaced above the baille 32 and terminating near the center thereof, and a lower, downwardly and inwardly extending portion 34 which joins the top of the conical section 24 of the burner grating. The top portion 33 of the inner casing lies adjacent to the lower edge of the fan blades. At the center of the upper horizontal portion 33, an annular opening 26' is formed concentric with the shaft 26. A conventional fire screen 33' extends from the edge of the opening 26' down to the baffle 32. This screen extinguishes any flames coming from the initial vaporization by partial combustion of oil sprayed from the disk 29.

from the disk 29 during normal operation of the device.

A small firing tube 36 communicates with the interior of the vaporization chamber formed by the baffle 32 and the casing 34 and with the burner grating 23.

In the operation of the device of this invention in the modification shown in Figure 1, the disk 2 is put into motion and oil is delivered thereto through the hollow shaft 3. The finely divided spray formed off the edges of the disk 22 is ignited by the spark plug 2i. It will be found that even in the heavy oils there will usually be enough of certain of the lighter constituents vaporized to such an extent that they will ignite under these conditions. If ignition cannot be brought about by a spark plug, other means, such as a torch, may be employed.

The fan 20 is put into operation. drawing air from the conduit i8 in amounts determined by the setting of the valve i9 and gaseous products from the vaporization chamber through the pipe IS. A circulatory motion is set up by the circulation of the fan, which draws gases from the vicinity of the grating ll, up the intake throat 8, through the vaporization chamber I, around the heme i3, and into the intake side of the fan. When the device is first put into operation, air will be drawn from the vicinity of the grating II, and combustion will be supported in the vaporization chamber.

As the vaporization chamber becomes heated, the incomplete combustion willincrease until substantially all of the oil will be vaporized, forming a rich combustible gas. The flames in the vaporizer will expand in proportion until they extend down around the baille l3. When this condition is reached, the flames will shoot out of the opening I! and ignite the gaseous mixture being delivered through the grating.

As soon as complete combustion has spread over the face of the grating ii and the grating ill, the gases being drawn therefrom up the intake throat 6 will be inert in the sense that they will not support combustion. The partial combustion which had been taking place in the vaporization chamber will be automatically stopped by the lack of combustion supporting gases and the vaporization thereafter willbe continued by the utilization of the sensible heat of burned products of complete combustion drawn from the flame side of the burner grating.

The operation of the modification shown in Figure 2 is substantially the same as that shown in Figure 1. The device is more compact, due to mounting of the fan and disk upon the same shaft, and is more easily insulated to.prevent radiation losses. The firing tube 38 differs somewhat from the firing openings IS in the device shown in Figure 1, but it functions in the same manner.

The drawing is merely illustrative of certain specific embodiments of my invention. It is understood that the claim to invention is limited only by the scope of the method and article claims following.

What I claim is:

1. An oil burner comprising a vaporization chamber, a burner grating, means for supplying air to said grating, means to supply fuel to said chamber, means to draw gases from the combustion side of said grating through the vaporization chamber and to discharge the resulting products through the grating, means for igniting the fuel in the vaporization chamber, means for thereafter igniting the gaseous products being delivered through the grating, the combustion at the grating automatically stopping combustion in the vaporization chamber by causing only inert gases to be delivered thereto.

2. An oil burner comprising a vaporization chamber, a burner grating, a fan for distributing air and gases to said grating, a duct positioned to draw gases from the vicinity of the grating on the flame side thereofthrough the vaporization chamber and to the fan, and means for distributing oil in said vaporization chamber.

3. An oil burner comprising a vaporization chamber, a burner grating, a fan for distributing air and gases to said grating, a duct positioned to draw gases from the vicinity of the grating on the flame side thereof through the vaporization chamber and to the fan, means for igniting the gases in the vaporization chamber, and means for igniting the air and gases being delivered through the burner grating from the combustion in said vaporization chamber.

4. An oil burner comprising a burner grating, a vaporization chamber, means for supplying fuel to said chamber, means for distributing said fuel in a finely divided form, means for drawing hot gases from the burner grating through said vaporization chamber, and means for supplying the products obtained therefrom to the burner gratplete combustion.

6. An oil burner comprising means for initially vaporizing fuel oil by partial burning of the oil, means for supplying air sufflcent for complete blue flame combustion, means for mixing the products of said partial burning and the oil so vaporized with said air, means for igniting said mixture, and means to thereafter vaporize the fuel oil by direct contact with a portion of the hot products of complete combustion.

CHARLES A. FRENCH.

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