US2086885A - Liquid fuel burner - Google Patents

Description

July 13, 193'?.

R. M. SHERMAN 2,086,885

LIQUID FUEL BURNER Filed Jan. l5, 1933 2 Sheets-Sheet l July 13, 1937. R M SHERMAN I `2,086,885

LIQUID FUEL BURNER Filed Jan. 13, 1933 2 Sheecs--SheerI 2 Patented July 13, 1937 PATENT orifice LIQUID FUEL BURNER Itallston M. Sherman, signor to The Silent Glastonbury, Conn., as- Glow Oil Burner Corporation, Hartford, Conn., a corporation of Connecticut Application January 13,1933, serial No. 651,537

3 Claims.

This invention relates to liquid fuel burners 4and has for its object, among other things, the provision of vmeans for controlling the flame in such burners, such means being embodied ina 5 relatively simple arrangement of parts adapted to be so controlled that a number of burner units supplied from the same source of liquid fuel supply may be brought to full flame and may be operated either simultaneously or .at different times. This invention also contemplates improvements in the construction and operation of the burner itself.

These and other objects of the invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one specific em- ,bodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawingsr- Fig. 1 is a plan View in partial section of the base of a burner here employed to illustrate one embodiment of the invention, the parts above the base being broken away;

Fig. 2 is a central, longitudinal section of the burner shown in Fig. 1, taken on the line 2-2 in Fig. 1, showing the `combustion tubes or shells vand cover plate in place; 1

Fig. 3 is a vertical section on an enlarged scale of that portion of the burner coinciding with the point of liquid fuel delivery, such section showing the oil delivery conduit and pilot wick compartment;

Fig. 4 is a plan view on a reduced scale, partly broken away, showing two burner units with connections to the fuel supply receptacles; and

Fig. 5 is an elevation in partial section, also on a reduced scale, showing the fuel supply re-l ceptacles for the two burner units shown inv Fig. 4 and their immediate connections.

Referring to the drawings andto the embodiment of the invention which is here submitted for illustrative purposes, as regardsthe feature of automatic lighting the invention has application to a wide Variety of liquid fuel burners, but it is here shown as applied to a burner of the socalled combustion tube type comprising, as will be seen from Fig. 4, two separate burner units A and B mounted on the same support, each of which units is of substantially the construction 50 shown in Figs. 1 to 3 inclusive.

Referring rst to Figs. land 2, each unit comprises a cast iron base member II, the bases of `the two units being embodied in` one casting connected by webs I3 (Fig. 4) and supported on the licor in anysuitable manner, as. by a rod or pedestal connected to the central web. Each base (Figs. 1 and 2) comprises an outer, annular plate I5 and an inner, annular plate I1 connected one. to the other by a series of webs I9 (Fig. 1), herein 'four in number, and providing for annular air .admission spaces ZI between the plates, the spaces being interrupted only by the webs I9. The inner plate is provided with a central air admission opening 23 surrounded by an up-turned ring-like flange 25, the outer edge of said inner plate having also an up-turned ringlike flange 21 spaced from but concentric with the ange 25. The flanges 25 and 21 together with the bottom plate I1 form a relatively wide annular trough 29 in the form of a channel, presenting a fuel space or chamber to which liquid fuel (herein referred to as oil for purposes of description) is admitted through an opening 3| in the bottom of the channel. The top of the space defined by the channel is closed, except for the annular opening which permits direct escape of vapo-rized fuel to the combustion chamber, by a removable annular coverY plate 33 seated on the upper edge of the flange 25 and provided with a downwardly extending rim or sleeve 35 which ts within the flange and positions the cover plate thereon. The walls of vthe cover plate extend outwardly over the channel 29, its outer peripheral edge portion being directed downwardly but spaced vertically from the bottom of the channel and peripherally from the inner walls of the flange 21 to provide the said annular exit passage for the vaporized oil into the overhead combustion chamber. 'Ihe edge of the cover plate is formed to provide a seat for a perforated sheet metal cylinder or shell 31 constituting one of the combustion tubes of the burner. A similar but larger shell 39 is removably seated on the shouldered edge of the upright llange 21, the two shells forming between them a combustion chamber 4I. Preferably the outer edge 43 of the cover plate 33 extends slightly beyond the inner vertical limits of the combustion chamber so as to somewhat restrict the annular exit passage thereto of the oil vapor.

On the outer annular plate I5 there is also provided an annular fuel trough or channel 45 between the upright spaced, concentric flanges 41 and 49, and concentric, spaced, perforated, sheet metal cylinders 5I and 53 are removably seated on the shouldered edgesof such flanges to form between them a combustion chamber 55. The outer fuel channel 45 is connected with the inner, wider, fuel channel 29 by means `of supply ducts 51 (Fig. l) formed in the webs I9,

the oil supply opening 3| being positioned in the inner channel between two of such ducts. A removable cover plate 59 is provided with its outer periphery resting on the top of the sheet metal cylinders 31, 39 and 53, such cover plate closing the top of the intermediate, annular, air charnber 6l between the shells or tubes 39 and 53 and the top of the inner air space 63 within the inner tube 31. Such plate leaves an annular opening at the top of the outer combustion chamber and is provided with a series of openings 65 registering with the inner combustion chamber 4i to provide for the escape of the products of combustion.

In the operation of a burner of this type, the burner is started by a preliminary heating operation, in the course of which the burner partsA are raised to such a temperature that oil admitted to the base is vaporized through the heat "f generated by the burner, so that subsequently,

in the normal or established operation of the burner, the oil vapor circulates through the channels and interconnecting passages and enters the combustion chambers where it commingles and is burned with the air admitted thereto.

In the burner operation, the oil is fed to the burner usually by gravity from some source, such as a constant level supply receptacie, providing for a definite running or normal feed level which can be accurately xed and maintained. Such a level provides for the admission of oil to the bottom of the fuel channel in the base but limits the height to which liquid oil may rise the base to some xed point therein, such, for example, as is represented by the dotted line X-X in Fig. 3.

'Ihe preliminary heating of the burner may be accomplished by various means, but resort is commonly had to asbestos wicks permanently positioned in the fuel channels, these being first saturated by admitting oil to the burner base and then ignited manually by means of a lighted taper inserted from without through the tops of the combustion chambers. The oil supply is then checked until the wicks burn freely, after which the oil supply is increased until the burner develops its full heating capacity, when it burns through vaporization of the oil independently of the wick and may be regulated by controlling the rate of oil supply.

In the illustrated embodiment of the invention, an automatic lighting device is provided which comprises a constantly burning pilot light afforded by a pilot wick device, the latter supplied with liquid fuel from a level below the normal running feed level of the burner, so that it remains lighted during such period as the burner is out of oper'- ation. Such pilot light is so positioned that as soon as oil is supplied to the base at the normal operating level it will ignite the oil and create a pre-heating flame in each separate combustion chamber of the burner, but, on the interruption of the oil supply at its normal running level and extinguishment of the main ame in each combustion chamber, the pilot light will continue to burn.

Referring to Figs. 1, 2, and 3, where one form of the igniting device is illustrated as applied to each burner unit, the base is shown as supplied with the usual main or starting asbestos wicks 61. and 69 of annular form, the nrst of which is positioned in the outer part of the narrow channel 45 and the second in the outer part of the wide channel 2S, .the bottom of Ithe wick 69 being cut away at the mouths of the ducts 51 to permit free flow of liquid fuel to the outer channel. In the normal operation of the burner, oil is admitted to the base through the supply opening 3l from the tubular conduit or pipe length 1l threaded into the bottom of the base and depending vertically from the base, the bottom of the pipe being closed by the threaded cap 13 and a connection 15 for the main oil supply pipe being attached to the pipe 1| at a point preferably somewhat above the lower closed end thereof. The depending pipe length provides a fuel compartment or well in which is positioned the elongated pilot wick 11 extending preferably well toward the bottom of the compartment and in any event below the pilot light level, which, for illustration, may be represented by the line Y-Y (Fig. 3), which level is maintained by means later described.

The pilot wick 11 is in igniting relation to oil when entered into the channel, and for the purpose extends upwardly into the fuel channel 29, and herein into the annular space connecting such channel with the combustion chamber Al, being positioned closely adjacent the main wick 63, and herein pressed edge i3 of the cover plate 33 so that its flame is adapted to ignite the oil conducted into the wick B9 by saturation or capillary attraction.

rIhe covered portion of the wide channel 2S constitutes a vaporizing chamber which is sub- Ilect to the heat transmitted to the thin sheet metal cover plate 3,3 from the inner air chamber and the highly heated walls of the combustion tubes 31. To direct the liquid fuel entering the base through the supply opening 3l inwardly i" into the vaporizing chamber and thence around the same and beneath the vaporizing cover plate and before circulating through the inner and outer wick holding channels and the passages connecting the same, the bottom of the wide channel is provided with two arc-shaped, raised wall portions 19 (Fig. l)` intermediate the flanges 25 and 21, such wall portions extending part way around the channel to ja point opposite the oil supply opening 3 l, a gap 8l, the opposite ends of said wall portions terminating on opposite sides of the supply opening, whereat they are turned radially outward and connected to the flange 21 by the extensions 83. The extensions 83 lie between the opening 3l and the next adjacent ducts 51, so that any liquid fuel entering the channel, in being distributed to the various passages of the base, must first flow inwardly toward the inner wall 25 and thence around the same to the gap 8l, thence around the outer wall 21 of the channel and through the ducts 51 to the outer groove 45.

Referring to Figs. 4 and 5 the main running oil supply for the two burner units is derived from the same constant level feeding device. While the latter may be of any desired type, herein for illustrative purposes it comprises the chamber or receptacle 85 to which oil is fed by gravity through the pipe El from a supply reservoir 89, which is replenished from time to time as may be necessary from any suitable source, such as the supply pipe 98 connected to a main supply tank (not shown). The chamber 85 is provided with a float 9i carrying a valve 93 which controls the supply orice from the reservoir 89, the action of the vfloat controlled valve establishing and maintaining in the receptacle 85, through gravitation of oil from the reservoir, a level conforming to the desired running level X-X at the burners A and B.

against the same by the whereat they are separated by Oil is fed separately by gravity from the common constant level chamber 85 to the two burner units A and B through the supply pipes 95a and 95h, respectively, communicating with the bottom of the chamber 85 and connected to the pipe eX- tensions Silla` and S'lb, each of which connects with the depending compartment 'll of the corresponding burner unit through the pipe connection l5. A controlling valve S9@ is provided in the supply pipe 95a and a seperate controlling valve 99D in the supply pipe 95h, so that the supply of oil at the feed level X-X may be established in respect to or withdrawn from both units simultaneously or independently each of the o-ther.

To maintain a constant and uninterrupted oil supply for both burner units at the lower pilot light oil level Y-Y, there are provided separate sources of supply for lthe twofburner units comprising the constant level oil receptacles lilla and llllb. These consist of small chambers fed from the supply pipes a and 95h, respectively, at a point in each case between the cut-off valve 99 and the higher level chamber 35, the supply orifice in each small chamber llll being controlled by a float-actuated valve which establishes and maintains in each receptacle a level conforming to the desired level Y-Y. The bottom of the chamber lilla` opens directly into the supply pipe 97a and that of the chamber Illlb directly into the supply pipe B'lb, so that the closure of the valves 99a and 91) cannot interrupt the supply of oil to vthe pilot wick compartment at the level Y-Y.

With the described arrangement the pilot wick compartment in the depending pipe ll of each burner remains constantly filled with o-il supplied from the chamber (lilla and IUIb) up to the level Y-Y, and the pilot wicks for both burners continue to be wet or saturated with oil so that after being initially lighted such wicks continue to burn indefinitely. When it is desired to start in operation either one of the burner units, as, for example, unit A, the control valve 95a is opened admitting oil from the receptacle 85, the oil entering the base of the burner and rising to the level X-X, thereby wetting or saturating both main wicks. The admission of oil to the channels is followed immediately by the lighting of the main wicks by the pilot wick, the name traveling from the wick 69 through ducts 51 to the outer wick 6l, the burner thereafter reaching its full, normal operation in the usual manner. If the main oil supply is cut off by the valve 99a, the burner is cut out of operation but the pilot wick continues to burn. Since both units, though receiving their main running supply of oil from the same source of supply, receive their continuing pilot wick supply from separate constant level sour-ces, they may be started together or separately and each may be operated at full or partial capacity independently of the other.

While I have herein shown and described for the purposes of illustration one specific embodiment of the invention and one specic application thereof, it is to be understood that extensive changes may be made in the details, form, relative arrangement of parts and connections, and that various applications of the invention may be made other than that to the specific form of burner herein shown, all without departing from the spirit of the invention.

1. The combination with a plurality of liquid fuel-burners, of high and low fiame fuel feeding means comprising a first source of liquid fuel supply with means for maintaining it under a constant head, said source communicating with each of said burners, connections for supplying each of said burners from a secondary sourcev of liquid fuel supply maintained under a relatively lower head, there being a separate secondary source for each burner and the connections from each secondary source being independentV of the connections from the other secondary source, and means intermediate said first source and each of said burners for controlling the delivery of liquid fuel from said first source to the respective burners while leaving unimpaired the delivery of liquid fuel from said second source to said burners. Y

2. The combination with a plurality of liquid fuel burners, of yhigh and low name fuel feeding means comprising a first constant level fuel chamber communicating with a source of liquid fuel and with each of said burners, relatively lower constant level secondary fuel chambers fed from said source of liquid fuel, one secondary chamber communicating with one of said burners and the other communicating separately with another of said burners, and means intermediate said rst chamber and each of said burners for controlling the delivery of liquid fuel from said first chamber to the respective burners while leaving unimpaired the delivery of liquid fuel from said second chambers to their respective burners.

3. The combination with a plurality of liquid fuelburners having each a pilot light device, of a common main supply source of liquid fuel for eachl RALLSTON M. SlIl-llR/MANn

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