US2113252A - Oil burning - Google Patents

Description

C. A. FRENCH Aprifi 5, 1938.

OIL BURNING Filed NOV. 8, 1934 Wm m X. e @WJ 4 mm wa FL lmmilsri m a Q m 6 Patented Apr. 5, 1938 OIL BURNING Charles A. French, Riverside, Ill., assignor to Mark C. Bates, Chicago, Ill.

Application November 8, 1934, Serial No. 751,974

4 Claims.

My invention relates in general to the burning of oil. It relates more in particular to special types of applications wherein either a radiant flame or a blue flame may be produced with the 5 same equipment.

The present invention has special application to the treatment of molds for metal casting. For convenience, it will be explained in connection with such use, although, as will appear, it may have other applications.

In .casting certain types of metal articles, steel molds are used and it is customary, in order to prevent sticking of the cast articles to the mold, to preliminarily smoke the inside of the mold is so as to deposit a layer consisting mostly of carbon entirely over the inside surface of the molds. If molds are handled by hand, it is possible to obtain fairly good results by the use of an ordinary smoking smudge wherein waste, for example, is saturated with oil to form a torch, and this torch burning with a yellow smoking flame can be manually applied against a surface to smoke it; It is common practice in the casting art, however, to mount molds on a large rotating support so that the molds travel in a circle and at stated positions are automatically closed and opened, either to discharge a casting or to prepare for pouring. In these installations, it has become customary to smoke the molds by means of an acetylene flame placed so as to be directed against the inside of the molds while they are open. Although fair results have been secured in this manner, there are many disadvantages to the system well known to those skilled in the art, not the least of which is the expense involved.

An ordinary radiant flame resulting from the burning of illuminating gas or fuel oil cannot be used because the character of the flame must be adjusted and in part a non-smoky or substantially blue flame is desired to preliminarily heat the molds before pouring operations are started.

The principal object of the present invention is the provision of improved means for treating molds of the character described.

Another object is the provision of simple means for producing either a radiant flame or a blue flame at the same burner.

5 Another object is the provision of a flame, the fuel content of which can be adjusted over a wide range. 4

Other problems, objects and features involved in the present invention will be apparent from a consideration of the following detailed description taken with the accompanying drawing, wherein Fig. 1 is a fragmentary sectional view showing one embodiment of the invention; I I

Fig, 2 is a sectional view taken on the line 2-4 of Fig. 1; and Fig. 3 is a sectional view taken on the line 3-4 of Fig. 1, a pair of mold sections being indicated in the figure.

According to the main features of the present invention, I provide a generator for converting a liquid hydrocarbon into combustible vapor, mix this combustible vapor with air of proportions for completely burning all hydrocarbon vapors, and conduct the combustible mixture through a manifold to a burner where it is adapted to burn with a blue flame. This burner is positioned so as to have its flame directed suitably, for example, against the inner surface of a pair of mold sections. Means is provided for enriching the mixture delivered to this burner by additional amounts of liquid hydrocarbon. In accordance with the preferred embodiment, a section of the line leading to the burner is utilized as a generator, a line burner being provided thereunder for the application of additional heat for vaporization, a liquid hydrocarbon being delivered in such a manner as to provide a constant feed, controllable as to amount and remaining uniform under substantially any operating conditions. By supplying additional liquid hydrocarbon fuel, the relatively lean mixture blue flame of the burner associated with the molds is converted into a luminous radiant flame, the mixture being of a reducing type with an excess of fuel capable of being deposited principally in the form of carbon black against the inside of the molds. controlled, the amount and character of the smoking can also be controlled.

Now referring to the drawing which I show, I utilize a vaporizing chamber I0 containing a supply of liquid hydrocarbon H, the liquid hydro- Since the mixture is capable of being carbon being delivered through a pipe i2 from a float chamber l3, whereby a substantially constant level is maintained. Liquid hydrocarbon is delivered to the float chamber l3 through a pipe it from a suitable source of supply, and a pipe I6 connected to the top of the float chamber and to the vaporizing chamber maintains a balanced pressure relation.

The top of the vaporizing chamber has a communication at H to a Venturi throat i8 into which a forcing nozzle i9 projects. Air is delivered through the forcing nozzle from a pipe 2| into a manifold 22. Vapors generated in the vaporizing chamber pass through the passageways I! and are entrained in the air passing through the forcing nozzle so as to mix with such air and be delivered to the manifold.

A robber casting 23 is placed between the manifold and the Venturi tube, and is connected to a pilot light assembly 24 having a nozzle 26. A combustible mixture is therefore delivered through the robber casting 23 to the pilot burner, where it is burned at the nozzle 23. The hot gases of combustion are delivered through a pipe 21 and an extension 23 to a point below the level of liquid in the vaporizing chamber. A bubble plate 29 secured to the bottom of the extension 23 breaks up the hot gases of combustion so as to cause them to rise up through the liquid hydrocarbon in more or less subdivided form, there- -by entraining vaporized hydrocarbon with them.

A valve 32 in the passageway or throat I! functions to control the amount of vapor delivered to the forcing nozzle, and an adjustable tapered rod 33 functions to control the amount of air delivered through the forcing nozzle.

A generator section 34 is connected to the manifold 22 and leads to a burner 36 adapted to burn the combustible mixture delivered by the generator with a blue flame. This burner has burner openings 31 positioned between guards 33, the function of which will be described more in detail hereinafter. The blue flame at the burner 36 can be used to preheat mold sections 33.

A Venturi tube 4| is provided between the manifold 22 and the generator section 34. A fuel pipe 42 terminates at the smallest section of the Venturi tube and leads to a float chamber 43 adapted to be supplied with liquid hydrocarbon through a pipe 44. A pipe 43-is provided substantially to control pressure conditions above and below the float, so as to deliver liquid oil to the pipe 42. A needle valve controlled by a thumb screw 41 is provided to control the admission of oil to the pipe 42. With this construction, a slight amount of oil is continuously delivered to the generator section 34 by being mixed with the combustible vapor passing through the Venturi tube from the manifold. Immediately below the generator section 34, I provide burner 48 adapted to be supplied with combustible mixture from the manifold 22. This burner being placed immediately under the generator, continues to deliver additional heat to the generator section to assist in convertingthe added liquid hydrocarbon to substantially vapor form. A trap 49 is provided in the generator section 34 for catching any liquid hydrocarbon which may fall to the bottom of the generator 34. This trap may be cleaned periodically by removing a plug 5|.

The burner 48 is of the type sometimes called a line burner in that it is relatively long and narrow so as to direct its flame along a substantial length of the generator section 34. It has guard sections 5 I a projecting upwardly therefrom and a plurality of burner openings 52 arranged in three rows, two of which project against the guards 5i. The rate of propagation of the blue flame is relatively slow, and this arrangement prevents any possibility of the flame being extinguished on account of the relatively high velocity of the gases passing through the burner openings, blowing it out. It also prevents dilution of gases before burning.

In operating the system, the main vaporizing chamber I0, having been cleaned, is preheated somewhat, and oil is then admitted thereto from the float chamber l3. The blower is started to force air through pipe 2| and through the forcing nozzle, and at the same time a source of heat is provided, sufllcient to vaporize some of the oil in the vaporizing chamber. A convenient method is to hold a torch at the opening of pipe 21 near the pilot light so that the hot gases of combustion thereof will be drawn to a point beneath the level of the liquid, or a gas line can be connected to the pilot burner so as to provide a gas flame which is then directed through the pipe 21 so as to generate the vapors. Whatever the method, the source of heat applied is gradually cut down as the vapors build up, and the ieanness of the mixture in the manifold is decreased. When the generator has been brought up to full operation, burner 38 is lighted and operated to raise the temperature of the molds preparatory to starting operations. When the molds have been heated sufficiently, the line burner 48 is lit and the set screw 4! turned to admit the proper amount of oil through the pipe 42. This increases the hydrocarbon content of the gas, and the flame burning at the burner 36 is changed from a blue flame to a radiant yellowish flame. It can be made as smoky" as desired by controlling the position of the needle valve. Molds will then be smoked in a desirable manner and the apparatus can berun indefinitely, barring usual survicing of the equipment. It will be noted that the burner 36 is of a type to burn a mixture producing a blue flame without being extinguished, and the radiant flame burns equally well without any adjustment.

Certain refinements and optional equipment usable with the invention are, of course, not shown, because they do not concern the present invention. Similarly, in actual practice shut-off means such as a valve is provided for the different burners, oil lines, air line, etc., without the exercise of invention. I also show the manifold 22 continuing on to indicate that additional burners of the burner type herein shown, or of other types, may be employed with the same main generator.

Although the invention is described as applied to the treatment of mold sections, those skilled in the art will understand that it has many other uses. There are many situations where a change in the character of the flame is desirable at difierent times, that is, not only a change in the amount or intensity'of the flame, but in the nature of the flame and the products of combustion resulting therefrom. By my invention, I may easily provide, for example, either a reducing flame, a substantially neutral flame, or an oxidizing flame. I may have a blue flame in which parts near the flame are heated only by contact with the hot gases of combustion; or I may have a flame in which the parts are heated by radiation from the flame itself.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. In oil burning apparatus, a vaporizing chamber, a Venturi tube, a connection between said vaporizing chamber and said Venturi tube, a forcing nozzle havi g its end positioned in alignment with said Venturi tube, means for delivering air through the forcing nozzle to withdraw vapors from said vaporizing chamber and mix the same with the air, a manifold connected to said Venturi tube to receive the mixtures of oil vapor and air, a burner, a passageway interconnecting said burner and manifold, and means 20 first-mentioned burner, and a Venturi opening for delivering additional oil to said passageway whereby to enrich the mixture delivered to sai burner.

2. Apparatus as defined in claim 1 including a second line burner positioned beneath said passageway and receiving combustible mixture from the manifold whereby to facilitate vaporization oi. the additional oil admitted to said passageway. 3. In oil burning apparatus, a generator for vaporizing oil and mixing the same with air, a manifold receiving the resulting mixture, a burner, a passageway connecting the burner and manifold whereby to supply said mixture to. the burner, a second burner disposed beneath said passageway and connected to said manifold whereby to receive a combustible mixture therefrom, means for delivering oil to said passageway above said second burner whereby to vaporize the same and enrich the mixture going to said between said manifold and said passageway, said oil being delivered to said Venturi opening whereby to facilitate vaporization thereof.

4. In oil burning apparatus, a generator for vaporizing oil and mixing the same with air, a manifold receiving the resulting mixture, a burner, a passageway connecting the burner and manifold whereby to supply said mixture to the burner, a second burner disposed beneath said passageway and connected to said manifold whereby to receive a combustible mixture therefrom, means for delivering oil to said passageway above said second burner whereby to vaporize the same and enrich the mixture going to said first-mentioned burner, a Venturi opening between said manifold and said passageway, said oil being delivered to said Venturi opening whereby to facilitate vaporization thereof, and means for adjusting the amount of oil delivered to said Venturi opening.

CHARLES A. FRENCH.

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