US2065264A - Burner - Google Patents

Description

0. L. BOCK Dec. 22, 1936.

BURNER Filed Nov. 2, 1932 VII A I W I ]i2 u nZ'0r: Oscar L. B00 in,

Patented Dec. 22, 1936 UNITED STATES PATENT OFFICE BURNER Oscar L. Bock, Madison, Wis. Application November 2, 1932, Serial No. 640,845

3 Claims.

This invention relates in general to a device for burning hydrocarbon, and particularly to a burner using oil as a fuel.

One of the important objects of the invention is to provide a newand improved burner embodying novel features and principles which are essential to the complete combustion of the fuel and the elimination of the carbon deposit or formation at the point of oil entrance into the chamber where the fuel is burned or consumed.

Another important object of the invention is the provision of a burner having a hearth over which temperatures higher than the end point of the hydrocarbon can be held and maintained throughout the vaporizing area, and the distributing of air unifomny over the entire hearth so as to unite at relatively high temperatures with the fuel and thereby cause complete combustion of the hydrocarbon.

A further object of the invention is the provision of a burner which has means for introducing oil onto the hearth in such a manner that the presence of the adjoining fuel feed pipe will not produce a cold section in the vaporizing area, and which is provided with means to control combustion so as to cause the flame to burn in suspension on the outer top lining of the burner.

A still further object of the invention is the method or process of combustion which consists in introducing a liquid hydrocarbon by gravity, onto the burner hearth at a relatively low temperature and then introducing the oil to a predetermined position onto the hearth which, during the normal operation of the burner, will have a temperature considerably greater than the end,

point of oil, and mixing air with the oil so delivered in such quantities so as to cause complete combustion of the hydrocarbon and cause the flame to burn in suspension above the outer peripheral rim of the burner hearth.

Other important objects of the invention are the provision of a new and improved oil burner having a vaporizing area which, during the normal operating cycle of the burner, is brought to temperatures not less than the end point of the fuel used; which has an air supply directly over the vaporizing area so as to eliminate pockets or cold spots; which directs the oil into the vaporizing zone and completely surrounds it with air; which is provided with means so that the flame will burn in suspension in any size of setting; which is so constructed and. arranged to insure the proper control and velocity and direction of the incoming air; and which insures the talging place of combustion in the presence of high heat reflecting media.

Numerous other objects and advantages will apparent throughout the progress of the following specification.

The accompanying drawing illustrates a selected embodiment of the invention and the views therein are as follows:

Fig. 1 is a detail vertical sectional view of one form of the improved burner.

Figs. 2, 3 and 4 are detail vertical sectional views of other forms of burners embodying the same or similar principles.

Referring to the drawing, each burner therein shown is provided with a unit (not shown) but which consists of a motor, blower housing, electric valve, float valve, burner frame, and other mechanism of the usual construction, all of which serve to bring a regulated amount of fuel and air in the proper proportion as desired to the combustion chamber. The above unit is an essential part of the burner and may be any con;- ventional unit just so draft is supplied proportionally to the amount of fuel consumed and the fuel delivered at a predetermined or definite pressure. Whether .the delivery of air and oil be accomplished by a power driven fan or by nat-' ural draft is not essential to the performance of the combustion chambers of the burners.

The particular types of burners herein shown for the purpose of explaining the invention each comprise a bowl or burner body 5 to which a draft tube 6 is operatively connected. particularly at the lower end of the body as shown in the various figures. Each body 5 may have relatively straight outer sidewalls 1 which may be in the form of a cylinder to conform with the normal shape of the fire box of the. heater or furnace into which the burner is set or applied. The exterior walls 1 of each burner, the bottom 8 and the flue 9, which is preferably centrally disposed, may be made of cast metal and lined or covered with refractory material in to provide a hearth H,

Each hearth H has a sloping or inclined portion I? which slopes downwardly and outwardly from the central flue 9 so that the liquid,-hydrocarbon or oil passing through the feed line it will flow directly upon the sloped or inclined surface i2 and then drain, by gravity, into the depressed groove Hi. Each hearth is also provided with an upstanding peripheral edge I5 which is located exteriorly of the groove l6 and extends a predetermined distance above the normal upper edge of the hearth A plurality of inwardly and radially extending fingers or arms 116 are spaced about the inner periphery of the upstanding edge l5 and extend over the outer edge of the fuel groove It as clearly shown in all the figures.

The fuel intake lines l3 are each disposed within or adjacent the central flue 9 and are each operatively connected to the line I! which is housed in the draft tube 6 and which lead to a suitable. source of liquid fuel supply. The flue 9 is in direct open communication with the draft tube 6 and therefore the incoming draft will always keep the fuel supply line at a relatively cool temperature and thereby prevent carbon deposits from occurring in the fuel line and at the outlet of the fuel line.

Each burner is also provided with a deflector l8 which may be arranged immediately above the flue 9 for the purpose of deflecting the air in a predetermined direction to cause the air to impinge against a portion of the hearth to cause proper mixing of the oil and air. thereby insuring complete combustion of the oil and causing the flame to burn in suspension.

From an examination of the drawing it is obvious that the fuel coming through the feed line will pass up through the feed lines and discharge from the ends of the feed lines and flow, as well as be blown by the air, outwardly along the sloping surface of the hearth and into the groove where it will become vaporized by the heat of combustion and mixed with the airv The arrows on the various drawings indicate the path of the air, the air striking a part of the hearth, turning a portion of the air downwardly and causing a rapid rotation with the fuel producing an intimate mixture which rises upwardly and [burns on top of the hearth at the outer peripheral edge thereof.

The burner construction shown in Fig. 2 is suitable or applicable to the larger types of burners and the air employed is delivered around the outer edge of the hearth to assist in supporting combustion on top of the hearth. In this later adaptation the fuel line I3 is provided with a plurality of fuel outlets I 9 which deposit the fuel onto the part of the hearth inwardly of the groove where it flows, by gravity, into the groove and is vaporized as previously mentioned. The outer walls 5 of the burner shown in Fig. 2 are spaced from a jacket 20 to provide an air pasage 2| communicating with the main air stream coming through the draft tube 6. A straight ledge 22 projects outwardly from the upper edge I5 of the hearth, and this ledge is provided with a plurality of spaced openings 23 through which the air in the passage 2| will pass to mix with the vaporized combustible fuel and assist in spreading the flame and burn in suspension.

In Fig. 3 the deflector i8 is made in two parts to provide a central air passage 24 which will cause the air to impinge against an inner side edge of the hearth, part of the air being deflected downwardly and then upwardly as denoted by the arrows in that figure.

In Fig. 4 the air is so directed that it first strikes the vertical portion 25 of the hearth where it will divide, part of it turning down. into the oil groove causing a rapid revolving gaseous mixture which will burn on top of the lining of the hearth as indicated at 26.

The principles involved in this invention deal with various grades of fuel 011 each of which may have a definite flash point, Distillation tests show point of fuel oil is usually between 550 degrees Fahrenheit and 600 degrees Fahrenheit. The process herein employed is characterized by the fact that the hearth be maintained at temperatures at least equal to those necessary to produce complete vaporization of the fuel burned. It has been found that if the air is not properly directed and the hearth properly shaped, the fuel will burn directly against the hearth and cause dirty, sooty combustion with considerable noise as well as cause carbon deposits. However, as in the present invention where the air has been directed in a particular manner and the shape of the hearth is of the kind herein shown. the flame will be lifted off the hearth and burn in suspension, causing highly efficient combustion, eliminating noise to a minimum. and leave the hearth clean without any trace of carbon. This latter accomplishment is caused by the shape and construction of the various distributing heads and by the shape and construction of the hearth.

The construction, herein shown, for the purpose of illustration only, show various burners having the entire vaporizing area supplied with a draft of air so as to eliminate carbon formation on the supply tubes as well as subjecting the entire hearth to the reflected heat of the flame and keep the hearth at a relatively high temperature.

In conventional oil burners the temperature of the vaporizing area is exceedingly low. This is particularly true around the point of oil entrance where the feed pipe is fastened directly into the lower portion of the pot. In some cases it has been found that the temperature will be as low as 250 degrees Fahrenheit with the end point of oil used being around 600 degrees. It is apparent, therefore, that a carbon formation of residual content will build up around these points. It is this low temperature which results in clogging the feed line of the conventional pot type burner. In some designs where higher temperatures exist, it was noted that the clogging or carbon deposit occurred inside of the end of the feed pipe due to the pipe becoming heated andthe oil vaporizing inside of the pipe without adequate air supply to completely burn the residue. It is, therefore, one of the preferred embodiments of this invention that the oil be projected or flowed onto the vaporizing area in such a manner that the feed pipe will remain cool whereas the vaporizing area will remain hot.

By locating the feed line itself in direct communication or in close contact with the main air stream, the feed line will be kept relatively cool, and the oil depositing onto the hearth, by gravity, or by being blown by the air passing around-it, there will be no contact whatever between the oil feed line and the vaporizing area. The present invention, therefore, provides a construction in which there will not be any stoppage or clogging of the fuel line because of the principle herein set forth.

Temperature tests performed on devices embodying the principles of this invention and as exemplified broadly in Fig. 1, show that during certain periods of operation, temperatures as high as 1100 degrees Fahrenheit will be maintained in the vaporizing area, while the feed pipe will only be slightly warmer than that of the incoming oil.

Attempts to establish similarly high temperatures in the vaporizing area of conventional pot burners resulted in the cracking of the oil as well as the leaving of carbon deposits. The oil cracking and carbon deposits occurring in pot burners were caused by insufficient air in the vaporizing area and because of the fact that the flame was not entirely in suspension. This condition was also enhanced by the fact that the side walls of the combustion chamber remained relatively cool.

The usual pot types of burners which usually employ the primary and secondary air principle, depend upon a relatively low temperature and a limited amount of air in the lower portion of the bowl for the operation of that type of burner results in a common weakness due to the low temperatures at which residual formation occurs around the feed entrance. The characteristics of the present invention and the employment of the process herein described calls fora relatively high temperature on the hearth suflicient to completely consume the residual content of the oil as-well as vaporize it completely through the end point.

The present invention provides for clean com bustion, complete combustion of the oil and for the burning of the flame in suspension about the peripheral edge of the burner similar to the rotary type of oil burner' without the employment of the expensive and intricate construction of the rotary type. The present invention produces burners which are highly eflicient and carbon free and which put into practice'the following principles which have been found to be essential and better by having the vaporizing area of the hearth maintained at a temperature not less than the end point of the oil used. The invention also supplies air and directs it over the entire vaporization area in such a manner as to eliminate pockets and cold spots as well as directing the oil into the vaporizing zone completely surrounded by air. The combustion takes place in the presence of a high heat reflecting medium and the resultant flame burns in suspension in any size and setting.

The burners herein shown and others constructed in accordance with the present teachings, may operate on the high-low" principle where a small fire is maintained during the socalled off-periods, and a high or large flame is maintained during the normal operating periods.

The invention is capable of being operated by a gas pilot by placing the pilot in such a manner as to .cause proper ignition. Or, electric ignition may be employed by the introduction of a jump spark or a heating element in the oil groove, or at some other point best determinecl to cause proper ignition.

When burners constructed in accordance with the present invention are operating on the highlow principle, and inthe event of flame failure, provision may be made to take care of the collected oil which will accumulate over the hearth. Means for taking care of the excess oil so accumulated may constitute a return line provided at some point in the hearth, or the accumulated oil may be allowed to flow through the central flue where it will flow to the bottom of the draft tube 30, Fig. 1, where it can be led into a trip bucket of some kind to shut off the machine upon the accumulation of a definite weight of oil.

The device, as herein shown, may also be constructed with a low oil head on the feed line by using a low point of entrance to the hearth so that the accumulation of oil will not be suflicient to cause overflow in the case of flame failure. When operating intermittently, this latter feature may be handled by controls which shut down the burner after a predetermined period of operation without establishing fire.

The invention provides a highly eflicient burner which can be very economically manufactured and causes a hot flame to burn in suspension. Furthermore, all danger or possibility of the clogging of the fuel line has been positively eliminated.

Changes may be made in the form, construction, and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its advantages, and the right is hereby reserved to make all such changes as fairly fall within the scope of the following claims.

The invention is hereby claimed as follows:

1. An oil burner comprising an upwardly extending receptacle open at the top, a hearth arranged in the receptacle, said hearth having an outwardly and downwardly sloping surface and an annular groove formed in a lower outer portion thereof and a wall above and outside of said groove, a fuel feed line arranged to convey fuel to said burner and to discharge fuel upon the sloping surface whereby oil gravitates to the groove, an air supply line leading to the interior of said receptacle substantially centrally thereof, and means cooperating with the air supply line and positioned to discharge air radially from said supply line above the surface of the fuel feed line and against said wall, whereby said air is divided into an upward and a downward stream.

2. A burner comprising a hearth having an air opening, an outwardly and downwardly sloping upper surface terminating in an oil retaining and vaporizing groove adjacent its outer edge and an upstanding marginal wall having an inwardly projecting portion overlying a material portion of said groove, means for flowing oil onto said sloping surface near said air opening, and an air distributor cooperating with said air opening and positioned to directly impinge a flat stream of air against the inner surface of said projecting portion so that said stream will divide into upwardly and downwardly directed streams.

3. A burner comprising a stationary hearth having an air opening, an outwardly and downwardly sloping upper surface on the hearth terminating in an oil retaining and vaporizing groove adjacent its outer edge and an upstanding marginal wall having an inwardly projecting portion overlying a portion of said groove, means for flowing oil onto the sloping surface, and an air distributor co-operating with the air opening and positioned to impinge a stream of air against the inner surface of the projecting portion so that the stream will be deflected downwardly and upwardly.

OSCAR L. BOCK.

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