US2064080A - Apparatus for burning liquid fuel - Google Patents

Description

Dec. l5; 1936. M. A. POWERS APPARATUS FOR BURNING LIQUID FUEL Filed Sept. 20,1934 3 Sheets-Sheet l IU/ s w Tm 3A n 0 W 6W 6M w 6 s A 0 6 Z v\\\\\\\\\\\\\\w\\\ M *0 C m l il! ml I l m llll A. ,u f o Dec. 15, 193e. M A POWERS 2,064,080

APPARATUS FOR BURNING LIQUID FUEL Filed Sept. 20, 1934 5 Sheets-Sheet 2 lll/[All 111/ f ai @o /f /aa o I I o INVENTOR M/zan A. Powe/1r Dec. 15, 1936. vM. A. POWERS 2,064,080

APPARATUS FOR BURNING LIQUID FUEL .E- gli INVENTOR //Vfo/z A. Powe/v 0 www #www ATTORNEYS' Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE:A

Timken-Silent Automatic Company,

Mich., a corporation Application September 3 Claims.

The present invention relates to apparatus for burning liquid fuel. More particularly my invention is concerned with apparatus for heating water by means of liquid fuel.

My invention intends to provide a boiler and oil burner assembly capable .of unusually high efficiency in operation as a consequence of. the particular relations, features of design and construction of the heat producing and heating exchanging or absorbing elements. It is a well known fact that boilers specially designed for use with oil burners are capable of operating at increased eiciencies over those into which the ordinary conversion type oil burner may be installed. This is conventionally accomplished by increasing the heat absorbing areas over which the hot gases are passed after leaving the combustion chamber. With my improved construe#` tion a greatly increased proportion ofthe total heat absorbed comes directly from the combustion chamber, resulting in a marked increase in efliciency, and greater output from a boiler of smaller dimensions. The use of a metallic hearth and a novel method of mounting the oil burner in the boiler assists greatly in producing these desired results.

In order to properly understand the functioning of my design it may be well todiscuss briefly the results ordinarily obtained by installing various types of oil burners in the conventional home heating boilers. Most heating boilers are designed for burning solid fuel, such as coal and the like, and when they are transformed into oil burning units, the short flue travel which has previously been satisfactory with theslower moving gases resulting from coal combustion is unable to absorb suicient heat generated to provide economical operation. The usual remedy is to increase the ue length and area, by the addition of extra boiler sections, thus giving the hot flue gases a better opportunity to cool before leaving the boiler. With the present increasing' demand most of the important boiler companies have announced the production of so called oil burning boilers, particularly suited for efliciently absorbing heat from oil combustion. Examination of the design of such boilers shows further attempts to build boilers with much elongated flue travela continuation in effect of the old field practice of adding flue sections to ineici-ent installations, in an effort to improve their operation.

It is only natural and logical for this to be the case, particularly as the resultant boiler may be called upon to operate with any one of several Detroit, of Michigan 20, 1934, Serial No. 744,833

types of burners, each type having a dliferent flame shape and varying Combustion chamber requirement. Hence any major change in the combustion chamber itself would not be practical, as some of the various burners likely to be used with the boiler would be seriously handicapped and others might be impossible to operate at all. For example, a large increase in the heating surface presented to the hot gases in the space normally occupied by free combustion chamber gases, so restricts the space otherwise available as to make it quite impossible to install many types ofv oil burners. A gun type domestic burner with its cone shaped flame could not operate effectively with the flame impinging at the back and top against projecting Water-backed portions. Carbon would be bound to collect interfering with combustion and themetal boiler parts subjected to the intense heat of flame impingement would deteriorate rapidly'. Likewise a wall flame burner in an extremely long and narrow boiler with corrugated Walls would prove inefficient while a gun type unit under the same circumstances might give fairly reasonable satisfaction. However it will be seen, as my inven tion is explained, that the integral design I have produced has inherent advantages and produces results far beyond thatv possible by any combination of conventional boiler and burner.

It is a major object of my invention to devise novel liquid-fuel-heated boilers that will operate with an extremely high degree of eliiciency, and yet which are of small dimensions and cheap of manufacture.

A further important object of the present invention is to devise liquid-fuel-heated boilers which are so constructedl that substantially al1 of the heat transmitted to the water is derived from the combustion chamber itself.

It is another object of my invention to provide a liquid fuel burner of the Wall flame type with a Water-cooled hearth; for the purpose of assisting in segregating the air flow from the fuel flow and thereby insuring improved combustion conditions.

It is another object of the present invention to devise a boiler especially designed for use with liquid fuel burners of the wall flame type which Vis so constructed as to present a maximum of water-backed heat-transmitting surface to the combustion region, and tovthereby substantially completely envelop the latter.

It is a further object of my invention to devise a boiler having a smooth heat transmitting surface in the region of the burning flame, and

a greatly increased area of heat transmitting surface immediately above the upper extremity of the burner flame, thereby insuring rapid heat transfer and yet avoiding spasmodic steam gen- 5 eration.

Another object is to devise a water heating apparatus having a combustion chamber unit surmounted by` a separate storage unit, the storage unit having a heat absorbing surface 10 over which ue gases issuing from the combustion chamber are adapted to pass.

It is still another object of my invention to devise a novel liquid fuel burning device particularly adapted for use with water heating ap- 15 paratus.

Further objects of the present invention will lbecome apparent, as the description thereof proceeds in connection with annexed drawings, and from the appended claims.

In the drawings:

Figure 1 is a vertical sectional view of a liquid fuel burning apparatus forming part of my invention and in the present instance it takes the form of a 'hot water heater, and the ignition 25 means and related accessories have not been shown as they form no part of the present invention.

Figure 2 is a fragmental sectional View of the flame ring assembly utilized in the heater shown 30 in Figure 1, and illustrates the method of securing it to the hearth.

Figure 3 is a perspective View of one of the brackets employed to hold the flame ring assembly in place.

35 Figure 4 is a fragmental sectional view of the flame ring and grill assembly of the mechanism shown in Figure 1, and illustrates the details of its construction.

Figure 5 is a vertical sectional view of a liquid 40 fuel burning apparatus of slightly modified construction, also forming part of the present invention.

Figure 6 is a sectional view taken on the line 6-6 of Figure 5.

Figure '7 is a vertical sectional view of a further modii-led form of liquid fuel burning apparavtus forming part of my invention, and

Figures 8, 9, l0, 11 and 12 are fragmental sectional views illustrating the configuration of 50 one of the Water cells shown in Figure 7, and

they are taken on the corresponding section lines of that figure.

Referring now to the drawings, wherein like reference characters have been employed to des- 55 ignate like parts throughout the several Views thereof, the device generally consists of a base section A, which supports a boiler or combustion chamber section B; a burner C; and a hot water storage section D.

Base A comprises an annular member I having an inwardly extending portion providing an annularseat I I. The inwardly extending portion of base member I 0 is reinforced by a plurality of triangular reinforcing webs I2. Boiler 65 B comprises a generally cylindrical, doublewalled body I3 having Aan inwardly extending lower portion I4 which not only supports the fuel burning apparatus but also constitutes the hearth of the furnace. Portion I4 of the boiler 70 defines a vertically extending cylindrical passage I through which the burner mechanism extends, as will be hereinafter explained. Boiler section I3 rests upon .seat II of base I Il and issecured thereto. `Any suitable securing means 5 may be utilized but I preferably provide member I3 with a plurality of lugs I6 through which bolts I'I extend and cooperate with nuts I8 to hold the parts in assembled relationship, y The inner cylindrical wall of member I3 is provided With a plurality of preferably radially .inwardly extending fins 2|, which operate to greatly accelerate the transfer of heat from the combustion chamber into the water contained in the boiler. .Fins 2I preferably extend from a region near the top of the boiler downwardly to a predetermined distance from the bottom of the boiler for a purpose that will presently be set forth. Fins 2|, intermediate their ends are each provided preferably with at least one notch 22 for the purpose of avoiding the development of severe internal stresses therein, due to the temperature gradient present throughout the longitudinal dimensions of the lns when the apparatus is in operation. Heat entering each n 2| is conducted radially outward towards the wall I9 through which it is released to the water, and in order to increase the rate of transfer from fins 2| to wall I9 they are preferably integrally formed therewith, when the boiler is cast.

It has been found that unless a large volume of conducting material is provided, heat ow will be restricted, the tips of the ns overheated and their general effectiveness quently, the proper form of the fin section is important and in general each fin 2I will be of gradually increasing thickness towards its base.

reduced. Conse- The number of fins used in the boiler will vary with the requirements of the particular installa-- tion, such as the combustion rate, and in most cases they will be present in greater numbers than that shown in the drawings, which have been reduced in number in order to simplify the disclosure.

- Boiler section I3 is provided with an inspection opening of ysuitable size which is closed by a door 23. Secured to door 23 in any suitable manner, is a plate 24 and a channel member 25 having a body of insulating material 26 disposed therebetween so as to minimize heat loss from the furnace in this region. If it is desired to inspect or service the burner or boiler, door 23 may be opened to give access to these parts.

Storage section D of the boiler is preferably constructed of pressed steel, and consists of a cylindrical part 32 which is preferably though not necessarily of the same diameter as the outer diameter of boiler B. Secured to the lower end of member 32, as by welding or a like operation, are a plurality of lug members 33. A plurality of lugs 34 are cast on the upper end of boiler B in alignment with the lugs on section 32, and a plurality of bolts 35 and nuts 36 cooperate with lugs 33 and 34 to hold the storage section in place on top of the boiler.

A lower head 31 having a central aperture'is welded in place within member 32. An upper head 38, having a central aperture therein, is secured to the upper end of section 32, as by a welding or like operation, and a central cylindrical member 39 extends through the apertures in members 3'I and 38, and is welded in place in Lower head 3l is provided with a pair of del pressed portions 4I, only one of which is shown. An aperture is provided in each o1' the depressed portions 4I, which align with apertures formed in the upper surface of boiler section I3, and a coupler member 42 extends therethrough, in order to establish fluid communication between the boiler and storage sections.

Central member 39 extends upwardly beyond the storage tank proper, and secured thereto by means of bolt and nut assemblies 43, is a flue member 44 having a horizontal portion 45 which is adapted to be connected to a flue gas exhaust pipe in any suitable known manner.

The entire device, including the sides and top of the boiler and storage units, are covered with any suitable form of insulating material designated generally at 48, in which are provided suitable recesses 49 to accommodate the various lug and bolt assemblies. The insulating material is then preferably covered by a sheet steel cylindrical member I, and a flanged cover 52.

Although other types of burners or fuel burning devices may be employed with the boiler and storage construction just described, I preferably employ a burner of the wall iiame type as it is this type of burner, with combustion initiated at the periphery of the hearth, and completed in close proximity to the boiler wall, which is suited for my purpose and renders the entire assembly capable of proper and extremely ecient operation.

The lower and upper inlet and outlet connections respectively for the heated water, irrespective of whether the apparatus employed as a hot water heateror a boiler are connected to the boiler and storage chamber in any wellknown manner and they have accordingly been omitted from the drawings.

The burner mechanism proper, designated as C, forms no part of the present invention as it is fully shown and claimed in my co-pending application Serial Number 729,928, filed June 9, 1934, and it will accordingly be only briefly described. Burner C is provided with a cylindrical portion which extends through aperture I5 in member I4 and is preferably secured in place therein by means of a plurality of cap screws 54, which are threaded into an enlarged boss on the inner portion of water leg I4.

The fuel and air supplying mechanism broadly consists of a motor 55, having a rotatable head 56 driven thereby. Head 56 comprises a plurality of fan blades 5'I and a plurality of slightly upwardly inclined fuel delivering nozzles 58.

Oil, in the form of unatomized droplets, is projected outwardly from head 56 toward a flame ring assembly comprising an annular ring 62 and a higher carbureting. ring 63. Rings 62 and 63 are positioned on the upper surface of fportion I4 of the boiler by means of bosses 6I and are secured in place thereon by means of brackets 64, spaced at intervals around the periphery of rings 62 and 63 and secured to bosses 6I by means of screws 65 or the like.

Disposed on top of ring 63 is a grill assembly which preferably consists of a plurality of plate members 66 having inner and outer flanges 61 and 68, respectively. Grill members 66 are secured togetxher in any suitable manner, (not shown)'/to form an annular grill, and they are provided with upturned Vanes 69, which serve to cooperate with the air currents and establish a partial vacuum on the upper sides of members 66, in a manner to be presently set forth. The grill assembly is preferably secured to member 63 by means lof a plurality of angle members 'II which are welded or otherwise suitably fastened to the grill members and to ring 63.

into the water contained in the storage tank The operation of my construction will now be described. The burner motor is started and the fuel is ignited in any well-known manner, and when steady combustion conditions are obtained, the conditions illustrated in Figure 1 exist. With reference to Figure 1, the oil is projected outwardly and slightly upwardly from head 56 as represented by the upper rows of arrows. The oil is preferably in a substantially unatomized state, and, therefore, the droplets do not ignite or atomize as they are passing from head 56 to ring 63. However, as the" drops strike ring 63, the impact causes them to be broken up into ne particles, and this action, when coupled with the high temperature of ring 63, establishes a region of nely divided fuel, adjacent ring 63, which is swept over and is mixed with air currents passing outwardly from head 56 as indicated by the lower rows of arrows, and which is suii'cient to estab- `lish an eiiiciently combustible mixture. The fuel mixture burns to some extent below the grill, but for the most part it passes upwardly through the openings in the grill assembly and burns above the grill.

As previously stated some combustion takes place below the grill, but most of it is confined to the upper side thereof, where intensely hot temperatures are produced, the fuel burning with a blue flame adjacent wall I9, with the result that a. large part of the heat developed is rapidly conducted to the water in and adjacent to this region. As is seen in Figure 1, the visible portion of the wall flame terminates adjacent-the lower ends of fins 2|, and it is highly desirable that this condition of combustion be maintained at all times, for the reason that if the fins extended downwardly through the visible flame region, carbon would not only collect `thereon, but spotty flame conditions would be established, and moreover, dangerous temperatures would be set up in the fins, and they would undoubtedly be seriously burned.

The hot gases of combustion, after leaving the visible flame zone, pass upwardly in surface engagement withns 2|, to whichA they communicate the greater part of their heat, thereby rapidly conducting heat to the water contained in the boiler. After leaving the boiler space, in

view of the ecient heat removing capabilities of the latter, the combustion gases have lost the greater part of their heat. They then pass upwardly in contact with lower head 31 of the storage space, and then into the cylindrical central member 39 of the storage space, where their upward travel is retarded by baille 40, with the result that the greater part of the remainder-of the utilizable heat of the flue gases is transmitted thereby keeping it up to the desired temperature. The iiue gases then pass outwardly through conduit 45 into the stack in a well-known manner.

It is therefore observed that the major portion of the heat generated by the burner is transmitted from the combustion chamber itself into the water, rather than depending upon extended flue passages beyond the combustion chamber to conduct the heat into water.

It should be particularly observed that as the' hearth of this boiler constitutes a water-backed.

.head 56.

deflection of the air currents emanating from This is desirable as previously explained, because separating the oil currents from the air currents tends to prevent initiation of combustion until the fuel actually impinges against ring 63, where it is desired that combustion take place.

The employment of the wall flame burner in the present boiler, results in a practical, leakproof and air-tight combination. rIfhis is in distinct contrast with the .refractory flame hearth, and refractory flame segments, which have been heretofore used in boilers and which absorb oil and frequently leak, and which in time crack, and allow entrance of excess air which would naturally result in improper combustion condition.

With reference now to Figures 5 and 6 of the drawings, I have illustrated a modified form of combustion chamber also having a slightly modi-- fied form of amering mounted therein. As many of the parts of this device are identical in structure and function to corresponding parts of the apparatus just described, certain parts have been omitted, and other parts have been given like reference characters.

With continued reference to Figures 5 and 6, burner C extends through and is secured to a metal plate 80 which is secured to a downwardly facing annular seat 8| formed on boiler |3a, by means of a plurality of cap screws 82. Plate 80 also functions to support the flame and grill rings and to this end a plurality of bracket members 84 are secured to the upper side thereof by means of screws 83. A hearth plate 85, which snugly embraces the stationary part of the burner head, rests upon the upper ends of bracket 84 and is secured thereto as` by means of a tack welding or like operation. Secured to the upper side of hearth plate 85, are a ring 86 and a carbureting Yring 81, the latter being lU-shaped in cross section. Rings 86 and 81 function in the same manner as the flame rings of the apparatus just described, and secured to the outer flange of ring 81 is a grill 88 having varies 89 struck out of the body thereof.

In this form of the invention, the upper end yof the boiler is brought inwardly to provide an upper water leg 13, having a generally cylindrical opening 14 at its center. This increases the heat absorbing area of the upper portion of the combustion chamber, and in order to increase the rate of heat transferred into the water, the lower side thereof is provided with fins15. Opening 14 is provided with fins 16, and the upper side of the water leg is provided with fins 11. Disposed above opening 14, and resting upon the boiler, is a baille member 18 which is employed to cause the hot flue gases to flow outwardly and then over the lower surface of storage tank 31, to increase the heat transfer and thereby prevent the ue gases from escaping directly into the stack.

It is observed that ns 15, 16, and 11 are not continuous but terminate adjacent their joinder with the walls of the boiler. 'I'his isdone in order to prevent the fins from burning. If the fins were continuous the metal of the ns adjacent the bends in the boiler wall would be compelled to i'mpose all of the heat transmitted thereto upon the corners ofthe upperwater leg 13, and it has been found that such corners should not be called upon to, and are incapable of dissipating the high temperatures to which a fin of this character is subjected in a boiler.

This device functions in very much the same manner as the apparatus just described. When the burner is operating, the oil and air emanating from head 56 take the paths indicated in Figure 5, and it is seen that the visible flame terminates adjacent the lowermost extremity of fins 2|, as in the previously described apparatus. In this construction, however, the hot gases of combustion, after passing upwardly along fins 2|, and over the vertical face |9 of base |3a, then pass inwardly over a lower surface of leg 13,-and in contact with fins 15, thence through aperture 14 in contact with ns 16. After the flue gases pass through aperture 14, the greater part of their heat has been abstracted, but they are then directed outwardly by baffle 18 into contact with fins 11, where further heat is abstracted therefrom. The flue gases then pass inwardly in contact with head 31 of the storage tank, and thence upwardly through the storage tank as described in connection with the first form of my invention.

With reference to Figures 7 to 12 of the drawings, I have illustrated a further modification of my invention, and the major change therein resides in the modified form of the combustion chamber utilized and the modied nature of the heat transmitting surfaces. In this form of the invention, the burner construction is the same as that utilized in the apparatus shown in Figures 5 and 6, and the lower end of the boiler is similar in form. Accordingly, similar reference characters have been'applied to these parts.

The inner wall of boiler |3b` extends upwardly above the flame ring 'and has a cylindrical configuration as illustratedin Figure 12, and it then branches inwardly in the form of a plurality of hollow ns or water cells 9|, which are preferably substantially radially disposed.

Cells 9| are observed to present considerable area to the furnace gases, and as they terminate ush with the flue gas exhaust passage 92, of the combustion chamber, they do not impede proper gas iiow from the combustion chamber.

It is moreover observed that cells 9| extend down- Y wardly and preferably terminate substantially the same distance from the flame as the fins employed in the previously described forms of my invention. If desired however, the cells in this form of the invention may be allowed to extend further downwardly for. the reason that they are of uniform thickness and are backed by a body of water and there is accordingly no danger of burning them. This provides a large area of exposed heat-absorbing area in the region of the hottest part of the flame, and/heat transfer in the apparatus is accordingly` extremely rapid. This boiler provides a large area of water contact and thereby reduces the-amount of heat to be absorbed per unit area, and thereby eliminates the likelihood of a blanketing layer of steam forming at a highly heated surface, which would not only reduce the speed of heat transfer, but would also undesirably agitate the water because of the spasmodic nature of the steam generated thereby. The large body of water with smooth passageways provided for the easy and orderly flow of convection current, makes the boiler extremely efcient in operation.

It is to be observed that in all of the forms of the invention disclosed, the amount of heat transferred from the combustion chamber itself is tremendously increased over that of boilers .heretofore proposed, with the result that it is sages beyond the combustion chamber for transferring the heat generated by the burner to the water or other medium. It is moreover seen that the particular type of burner utilized in the various forms of my invention forms an essential part of the combination, for the reason that it produces a flame that is in the nature of a wall, located in close proximity to the surfaces to be heated, with the result that the flame zone is not only placed in the proper position for most ecient operation of the unit, but also, as the flue gases naturally flow upwardly in contact with the fins and upper walls of the combustion chamber, they too are utilized to the best advantage. Further economies of operation resulting from the use of the wall type burner reside in the fact that the metal parts of the burner assembly reached their relatively high operating temperatures quickly and maintained their high temperatures during operation with resulting high cornbustion efficiency. In addition to the amount of heat transferred to the exposed heat absorbing areas by direct radiation from the flame, there is a marked amount of energy radiated from heated portions of the hearth (Figures 5 to 12), as the highly heated metal portions are maintained at a visible color heat during operation, and being largely surrounded by an absorbing heat surface, most of this radiant heat energy is effectively transferred.

It is to be understood that although I haveV illustrated a boiler 'and storage assembly having a cylindrical configuration, if desired an assembly of rectangular section having a flame ring assembly of similar shape may be employed without departing from the spirit of the present invention. It is to be moreover understood that the term boiler, as used in the present specithe meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a fuel burning apparatus, an upright boiler unit providing a substantially vertically extending combustion chamber, a centrally disposed liquid fuel burning device located adjacent the lower end of said combustion chamber for causing a flame to impinge on the sides of said chamber, and a substantially horizontally disposed watercooled hearth disposed ,between said fuel burning device and the sides of said combustion chamber, said fuel burning means comprising a flame ring seating upon the peripheral portion of said substantially horizontally disposed waterbacked surface and adjacent which combustion is adapted to take place.

2. The apparatus described in claim 1, wherein said liquid fuel burning device comprises a liquid fuel distributing device which is operable to project a layer of liquid fuel and a layer of air outwardly toward the sides of said combustion chamber in substantially segregated condition, and wherein said water-cooled hearth is operable to assist in segregating said fuel and air, in its travel from said fuel distributing device to said flame ring.

3. In a fuel burning apparatus, a substantially cylindrical upright boiler unit having hollow heatconducting walls defining a combustion chamber, said boiler unit at the lower end thereof having a hollow-Walled portion which extends inwardly and defines the floor of the combustion chamber and which is disposed in fluid communication with said first named hollow walls, and fuel .burning means disposed in said combustion chamber and operable to impart heat to said hollow walls and also to said hollow-walled portion of said boiler unit, said fuel burning means comprising a flame ring seating upon the peripheral portion of-said substantially horizontally disposed water backed surface adjacent which combustion is adapted to take place, said hollow- Walled portion of said boiler unit having a substantially centrally located aperture therein, and a liquid fuel and air proiecting mechanism extending through the aperture in said hollow Walled yportion of said boiler unit.

MILTON A. POWERS.

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