US2275395A - Fuel burner - Google Patents

Description

March 3, 1942. E. G. BAILEY FUEL BURNER 3 Sheets-Sheet l Original Filed Dec. 18, 1935 Numrw NvENToR Erw/7 @Baiiey .k-KKWTORNEY March 3, 1942. E. G. BAILEY 2,275,395

FUEL BURNER Original Filed Dec. 18, 1935 3 Sheets-Shee't2 l INVENTOR ffl/m Bai/ey March 3, V194:2. Eg 5, BAlLE-Y FUEL'BURNER original Filed Dec. 18, 1955 3 sheets-sheei :s

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mvEmoR1 ffl/Il? G Bcn/@ y ATTORNEY Patented Mar. 3, 1942 FUEL BURNER Ervin G, Bailey, Easton, Pa., assignor to The Babcock & Wilcox Company, Newark, N. J., a corporation of New Jersey Original application December 18, 1935, Serial No. 55,020. Divided and .this application June 10, 1938, Serial N0. 212,869

4.l claims.

This invention relates to improvements in fuel burners adapted for use in vapor pressure power generators of the drumless forced flow type suitable for service Where load conditions are of Wide range over a short time interval as, for instance, is characteristic in the mobile service to which power plants are subjected in locomotive and marine applications, and for which great flexibility is a requisite.

High eiciency of vapor generation from fuel heat requires not only that combustion be completed within the furnace space, and that the least possible excess air is present t all loads from zero to maximum, but, also, that the heating surfaceshall be properly disposed with reference to the furnace and the products of com- Y bustion tc promote heat absorption to the greatest degree through heating surface exposed within the .furnace area and beyond it. This requirement for least weight thus imposes a need for high rates of heat absorption per square foot of heating surface in order that the high degree of absorption ofheat for high efficiency is attained with a minimum of surface area. Smallest possible furnace size requires the highest possible heat liberation rate from combustion of fuel, B. t. u./hr./cu. ft., and for highest effiy ciency this must be accomplished with the least possible excess air and no unburned fuel.

One feature of the invention is the provision of improved fuel burner units having a supply of elements of combustion to insure wide range,

Fig. 4 is a sectional side elevation on the plane of line 4--4 of Fig. 3.

In detail- The forced flow vapor generator constituting this invention is diagrammatically illustrated in Fig. l to indicate gas flow, working fluid flow and sequence of contact with sections of the heat absorbing surface as contained within the enclosure represented by the clot and dash line indicative of the casing Walls. '.TfI'he flow path for the liquid and its vapor is vcomprised of several long small bore tubes connectecl` in parallel, ve being here shown, interruptedzpy an enlargement at the end of the vapor generating A'section which acts as a separator or collecto-rto divide vapor 'and liquid, the saturated vapor passing therefrom without liquid to a superheater, a portion of the entering liquid being carried through the tubes to the separator for the purpose of tube metal wetness and preventing solid deposits. This unvaporized liquid is finally diverted out of the flow path at the separator and withdrawn under regulated conditions.

The parts of the generator are arranged on two levels within vertical walls common to both. The lower level is occupied by the flat sided furnace, with horizontal bare tube walls on five sides, the sixth having the burner space with refractory arc-und it; at the rear end of the furnace there is a bank of horizontal tubes 228fdisposed across it. The hot gases of combustion pass from the lower to the upper level at the rear end 245 and return through a gas passage over the furnace roof to an air heater 282 above the burner before their exit. The upper level of the hot gas end is occupied by the superheater 242 which is screened from the radiant heat of the furnace partly by its position and partly by the lower level tube bank 228. The upper level is also occupied by an economizer 202 at the cooler gas end, by certain connections and by the separator-collector 232 located between the economizer 202 and the superheater Equalization of heat absorbed by the vapor generator tubes is assured by their position, and by providing for equalization or proportioning of liquid feedquantity and temperature to each of the five long small'bore tubes in parallel, lequalization of quality of Vapor or ratio of liquid "un# evaporized to vapor produced is assured, and each generating tube is kept wet internally by control of ratio of heat made available to quantity of feed, thereby overheating is prevented and this is accomplished with a minimum of excess liquid.

To assure equalization of heat absorbed by each of the several parallel connected generator tubes, each of one is so bent and so located as to be equally exposed to radiant lie'at of the furnace and equally swept by hot gases. Each tube occupies a portion of the height of each furnace side wall from end to end at a given level and a portion of the end wall at the same level, and each one makes one or more transverse passes across the gas stream in the furnace within the same level limit. Each tube also occupies a portion of the Width of the furnace .bottom and of the furnace roof from end to end of each. At the same time the burner is in one end of the furnace, the flame and the gases flowing longitudinally straight througth it, so there is thermal-symmetry all around the cross section of thefurnace, and any change in gas temperature or intensity of radiation longitudimechanical or steam, or combination oil atomizing and feeding head 265 movable along the support 264', Vas indicated, by loosening the thumb screw 26,6, this burner head having oil feed and atomizing steam supply 261 and 2'68, respectively, controlled by valves. A

'Ihe burner air chamber is 'entirely enclosed and insulated as indicated at 269. It has guide vanes and comprises a scroll shaped wall 210 to distribute air entering one side from the air heater 282 by way of a rectangular opening 21|. The vanes divide the chamber entrance area into air passage increments 212, 213, 214, 215, 216', and 211; and these increments extend around to the burner ring entrance so that there is an equalization of the air supply to the burner throughout the circumference of the burner ring. The sweep of these vanes, Iand the extended ones 218 in the windbox of the burner, are very carefully` shaped and stopped off at the right loca tions to insure a uniform delivery of air throughout the entire burner circumference, even if the air entering the burner air chamber is not equally distributed across the chamber entrance area.

In order to provide for ignition of the oil spray the burner entrance ring 258 has an opening 219 therein into which extends a suitable gas burner and automatic lighting device Openings 280 in the face plate 26|) equalize the air pressure in the main windbox with that in a secondary windbox 280 back of the face plate, the

secondary windbox communicating with the ringopening 219. Above the rect-angular opening 21| is the tubular air heater 282 through the tubes of which pass the spent combustion gases from the vapor generator and which they leave through the flue 283. This air heater, as will be evident, is at thefiring end of the vapor generator, and over it, and the air enters it at 254 and traverses the bank of tubes of the air heater directed to the burner air chamber or windbox so that the heat imparted to the air in its passage through the air heater 282 is not lost and the flow resistance is minimized by reason of the short travel of the air from the air heater to the burner.

To insure that the full capabilities of my vapor generator are realized in operation, auxiliary ap paratus of proper cooperative kind, and with appropriate controls', are provided, so that the combination has all of the use characteristics required for motive power service of the type previously described involving exlbility over the whole range from zero to maximum capacity per unit, high efliciency, light Weight and small space requirements for any size above that used in small automobiles.

This application' is a division-of my application. Serial No. 55,020, filed Dec. 18, 1935, now matured into Patent No. 2,170,342, dated Aug. 22, 1939.

While I have chosen to illustrate and describe a certain preferred embodiment of the invention, it is to be understood that this is by way of (not shown) .vanes terminating Within illustration only and that I am not to be limited thereby exceptvas to the claims in view oi' prior art.v

Iclaim:

1. The combination with a furnace having a circular burner port in one of the walls thereof,

a fluid fuel burner arranged axially of said burner port, means defining a wind box at the outer side of and surrounding said burner port, said Wind box having an air inlet at only one side thereof and arranged to effect an air ow through saidl wind .box in a plane at a substantial angle to the axis of said burner port, and means for distributing the air entering said air inlet substantially uniformly throughout the circumference of said burner port comprising a series of vanes in said wind box subdividing said air inlet and extendingv in spaced relation to'corresponding circumferential portions of said burner port, the burner port ends of said vanes being substantially equally spaced circumferentially.

2. The combination with a furnace having a circular burner'port in one of the walls thereof, a uld fuel burner arranged axially of said burner port, means defining a wind box at the outer side of and surrounding said burner port, said wind box having an air inlet at only one side thereof and arranged to effect an air flow through said wind box in a plane at a substantial angle to the axis of said burner port, and means for distributing the air entering said air inlet substantially uniformly throughout the circumference of said burner port comprising a series of vanes of different length and curvature in said wind box subdividing said air inlet and extending in spaced relation to corresponding circumferential por- 'tions of said burner port, the burner port ends of said vanes being substantially equally spaced circumferentially.

3. The combination with a furnace having a circular burner port in one ofthe walls thereof, means defining a wind box at the outer side of and surrounding said burner port, said wind box having an air inlet at only one side thereof and arranged to effect an air flow through said wind box in a plane at a substantial angle to the axis of said burner port, and means for distributing the air entering said air inlet substantially uniformly throughout the circumference of said burner port comprising a series of vanes of different length and curvature in said Wind box subdividing said air inlet and extending in spaced relation to corresponding circumferential portions of said burner port, said vanes having substantially equal circumferential spacing at their burner port end.

4. The combination with a furnace' having a circular burner port in one of the walls thereof, means dening a wind box at the outer side of and surrounding said burner port, said wind box having an air inlet at only one side thereof and arranged to effect an air flow through said wind box in a plane at a substantial angle to the axis of said burner port, and means for distributing the air entering said air inlet substantially uniforymly throughout the circumference of said burner port comprising a series of vanes in said Wind box subdividing said air inlet and extending in spaced relation towards corresponding circumferfntial portions of said burner port, said the circumference of said burner port and having substantially equal circumferential spacing at their burner port end.

ERVIN G. BAILEY.

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