US2077676A - Firebox construction - Google Patents

Description

April 20, 1937. s DARLING 2,077,676

FIREBOX CONSTRUCTION Fi led June 14, 1935 2 Sheets-Sheet l April 20, 1937. s. M. DARLING FIREBOX CONSTRUCTION Filed June 14,, 1933 2 Sheets-Sheet 2 Patented Apr. 20, 1937 NlTED STATES PATENT OFFICE.

FIREBOX CONSTRUCTION Application June 14, 1933, Serial No. 675,683

3 Claims.

The present invention is directed generally to boiler fireboxes, but more particular-l5 to locomotive fireboxes for securing a complete combustion of the fuel gases therein.

In the conventional locomotive firebox, the combustion space is so restricted and the time allowed for combustion is so short that it has been impossible, heretofore, to thoroughly mix.

the oxygen, carbon and hydrogen gases so as to secure a satisfactory percentage of the fuel energy heretofore wasted orto secure a complete combustion of the fuel, inasmuch as this combustion must take place before the gases reach the boiler tubes, because there is practi- -cally no further burning after this point in their travel is reached.

Heretofore, in order to lengthen this travel of the gases in a locomotive firebox, it has been the common practice to place in the firebox a solid bafile, supported by two or more water tubes, to compel all of the fuel gases to travel rearwardly and upwardly around the rear end of the bafile. The objection to this bafile is that it impedes the flow and constricts the'path of the gases and makes necessary the use of additional forced draft, which is secured by means of a large, multiple steam jet blower in the smoke box or stack at the front of the engine. This arrangement is further objectionable in that it involves a substantial waste of steam and accelerates the travel of the fuel gases out of the firebox to such an extent that a large portion of them pass out the stack unburned, in the form of smoke, resulting in great waste of fuel and the added nuisance of air pollution.

Another object of the invention is to provide a novel and improved form of locomotive firebox having a novel form of baffle mounted therein which is provided with a plurality of spaced perforations therethrough, so as to permit a substantial portion of the fuel gases to pass through these small channels, thus dividing the gases up into many fine streams, and thereby greatly facilitate their mixing together and compel them to contact a large area of refractory scrubbing surface, thus producing a large measure of surface combustion.

A still further object of the invention is to provide a novel arch construction for locomotive firebox which increases the area of path for and reduces the velocity of the fuel gases, thus easing up on the force required to draw them from the firebox into the boiler tubes, resulting in considerable economy of steam heretofore used by the stack blower.

A further object of the invention is to provide a novel steam jet nozzle which intimately mixes a hydrocarbon oil, steam under pressure and atmospheric air so as to augment the supply of oxygen and facilitate the mixing and combustion to the maximum extent of the gases distilled from the coal on the grate.

A still further object of the invention is to provide a novel form of nozzle located in the opposite sides of and extending through the waterlegs of the boiler so that they project far enough into the firebox to be maintained at a relatively high temperature in order to discharge the mixture therefrom at a high temperature.

A still further object of the invention is to provide a novel form of nozzle, actuated by high pressure steam carrying a regulated percentage of hydrocarbon oil, which entrains atmospheric air and also a portion of the hot gases already in the firebox, mixes them intimately within the nozzle, heats the mixture and projects it at high velocity across the firebox.

These and other objects are accomplished by providing a construction and an arrangement of the various parts in the manner hereinafter described and particularly pointed out in the appended claims.

Referring to the drawings:

Fig. l is a fragmentary vertical cross sectional view of a portion of a conventional locomotive engine embodying my improved firebox therein;

Fig. 2 is a cross sectional view taken on the line 22 in Fig. 1;

Fig. 3 is an enlarged detailed View taken on the line 3--3 in Fig. 1;

Fig. 4 is an enlarged vertical cross sectional view taken on the line 44 in Fig. 3;

Fig. 5 is an enlarged horizontal cross sectional view showing the construction of my improved nozzle;

Fig. 6 is a cross sectional view taken on the line 66 in Fig. 4;

Fig. 7 is a perspective view of my improved nozzle; and

Fig. 8 is a cross sectional view of the three way ejector-valve control, showing the same in closed position.

In one form of my invention, I have shown the same in connection with a conventional form. of locomotive, a fragmentary portion of which is shown in Fig. l of the drawings and generally indicated by the reference character 10. This portion of the locomotive engine comprises an outer wall or housing member H and an inner housing or firebox wall E2, the space between these walls forming the water circulating or waterleg of the locomotive. Extending across the forward end of the firebox is a vertical wall l3 to which are connected a plurality of spaced apart boiler tubes, generally indicated by the reference character it. These tubes are connected to this wall and extend forwardly in a manner well understood in the art. The rear end of the locomotive firebox is provided with the usual fire door l4 through which the fuel is discharged onto the grate generally indicated by the reference character i5. Extending around the locomotive firebox adjacent the rear side thereof is a convencharacter 5 8.

One of the essential features of the present invention includes this novel arch bafile which is provided with fire clay tile having perforations therethrough so as to permit a substantial portion of the fuel gases to pass upwardly through a multiplicity of relatively small channels, as well as around the rear end of the bafiie, thereby dividing the gases up into many fine streams, greatly facilitating their mixing together and compelling them to contact a large area of refractory fscrubbing surface, thus affording a large measure of surface combustion. With this type of arched perforated baffle, a greater area of path is afforded, thereby reducing the velocity of the fuel gases, and also reducing the force required to draw them out of the firebox into the boiler tubes, resulting in a considerable economy of steam used by the stack blower. The baflie in this instance, is preferably made of individual fire clay blocks, as shown i These refractory tile blocks extend from an inclined portion 28 of the vertical wall M in the forward end of the firebox upwardly and rearwardly on the tubes l! to a point substantially two-thirds of the distance of the entire longitudinal length of the firebox. Certain of these fire clay tile, particularly the intermediate ones thereof, are provided with spaced apart perforations, as shown at 22. Obviously from the above description, it will be readily seen that a substantial portion of the gases developed to the rear of the bafile will find their way through the perforations E2 in the baffle, thus dividing up the gases into many fine streams and intermingling them with the volume of gas coming around the rear end of the baffle.

In combination with this novel arrangement of bailie construction, I have provided a novel arrangement of steam jets which discharge fine jets of steam, in combination with a hydrocarbon oil and atmospheric air, through the side walls of the firebox, in a position fore and aft of the b aille, and transversely across it in opposite directions in the firebox. These nozzles are so constructed that the sharp jets of steam, under full boiler pressure,

draw a quantity of outside air into the firebox and further draw in and recirculate about an equal quantity of the extremely hot gases already in the firebox and, in the nozzle, mix them intimately with the incoming atmospheric air'and create a violent turbulence in the firebox which results in practically complete combustion. This arrangement includes a substantially U-shaped pipe or conduit extending around the rear and side walls outside the firebox, as shown in Fig. 2 of the drawings, and generally indicated by the reference character 25. Connected at spaced apart intervals along the U-shaped pipe 23 are T connections 24, to which are connected, by' means of reduced pipe connections, as shown at 25, nozzles 26. I-hese nozzles extend through spaced apart openings 2? located in the waterlegs on each side of the firebox, as clearly shown in Figs; 2 and 5 of the drawings. The particular construction and function of operation of these nozzles form an important feature of the present invention. These nozzles are provided with pointed nipples, as shown at 28, having small openings or apertures 29 on the inner ends thereof. Extending from a point below each of the nipples, and formed integrally therewith, are four oppositely arranged ribs 3%), which in turn, have their inner ends connected to a cylindrical portion 3| which has formed on its inner side a Venturi portion, as shown at 32. By examination of Fig. 5, it will be seen that these cylindrical or Venturi tube portions of the nozzles 26 extend into the firebox a considerable distance so that a portion of the gases within the firebox may be drawn inwardly between the ribs 38 to further heat the hot steam, hydrocarbon oil and atmospheric air mixture and commingling the same with the gases within the firebox. By referring to Fig. 4, the arrows indicate, the directions of travel of the gases within the firebox passing between the ribs 30 and into the discharge nozzle or Venturi of the nozzle. It will be further observed that atmospheric air is drawn in from outside the firebox through the openings 27 and passed between the ribs 30 of the nozzle in the manner indicated by the arrows in Fig. 5 of the drawings. The high pressure steam is supplied tothese nozzles and to the U-shaped pipe 23 by means of a connecting pipe 33, which in turn is connected to a supplemental connection or steam pressure box 34 connected to the upper end of the locomotive boiler as clearly shown in Fig. l of the drawings. Located in the pipe line 33, is a main shut-off valve 35 located above the oil supply for completely shutting off the system. Located below this shut-off valve 35' is a three Way ejector-valve, generally indicated by the reference character 37, which is of a special construction and on which a separate application is being filed to specifically cover the novel features thereof, but for the purpose of this application, suffice it to say that the three way ejector-valve 37 is manually controlled by lever 38 which actuates the valve member 39. The valve member 39 is provided with a normally vertically extend ing bore 30 which is adapted to register with the connecting ends of the pipe line 33, as clearly shown in Fig. 4 of. the drawings. Mounted in threaded engagement in a reduced portion of the bore 40 in the valve member 39, as shown at 4!, is a sleeve 42. The lower end of the bore 40 is slightly larger than the outside diameter of the sleeve 42 so as to form an annular channel 43 therearound, adjacent the longitudinal center of the valve member 39. Located at right angles with respect to the bore 4t and extending through one side of the member 39 is a third communicating passage of relatively smaller diameter, as shown at 44, through which the hydrocarbon oil is drawn and then discharged through the annular space 43 surrounding the sleeve 42, so as to evenly distribute and atomize the incoming oil into the steam in the pipe line 33. It will be observed from the above description that when the manual lever38 of the three way ejector-valve 3'! is actuated from the position shown in Fig. 4, to the dotted line position, shown in Fig. 8, the source of steam pressure is disconnected from the pipe line 33 and the associated nozzles and at the same time the oil supply hereinafter described is also disconnected.

In order to accelerate flame propagation through the gases put into a violent state of agitation by means of the jets of air previously described, I introduce into the line conveying the steam to the jets in the nozzles, a few drops per minute of light hydrocarbon oil, such as gasoline, kerosene, petroleum condensate, usually called distillate, or similar quickly flashing hydrocarbon oil. This hydrocarbon oil is supplied from a tank 45, fastened by means of brackets 46 to the rear outside wall of the firebox at a point adjacent the three way ejector-valve 31. The function and operation of this ejector valve is to draw and atomize the oil into the current of steam passing through the pipe 33. The fuel oil in the tank is normally kept under steam pressure by means of a tube connection or pipe generally indicated by the reference character 41, which has one end connected to the main pipe line 33 above the three way ejector-valve 31 and the other end extending into the tank to a point adjacent the bottom thereof, as shown at 48. The fuel tank is connected by means of a conduit or pipe 43 to a needle valve generally indicated by the reference character 50. This needle valve, briefly, comprises an adjustable needle 5!, for definitely measuring or controlling the amount of oil discharged into the steam line. The nozzle of this valve, as shown at 52, extends into a short horizontal cylindrical chamber 53 constituting a sight feed mechanism, which is filled with water, as shown at 5:1. Interposed between this chamber 53 and the connection to the three way ejector valve 31, is a supplemental shut-off valve, generally indicated by the reference character 55. From the above description, it will be readily seen that the Valve 55 constitutes a manually operable device, by means of which the locomotive fireman may close the oil conduit so that the system may be operated without oil if so desired.

The specific construction of the three way ejector valve, the needle valve and the cylindrical sight feed is preferably made as a unit and is the subject of a separate application covering the specific features therein.

Summarizing the operation of my improved locomotive firebox construction, let us assume that the steam pressure of the boiler is under normal full pressure and that the three way valve 31 is open to the position shown in Fig. 4, and that the needle valve 50 is open so as to permit a few drops of hydrocarbon oil per minute to be introduced into the steam line 33, from where it is conveyed to the U-shaped pipe connection 23 into the nozzles 26 located on the opposite sides of the boiler firebox. As previously pointed out, these nozzles are so constructed that the sharp jets of steam under full boiler pressure, draw a quantity of outside air into the firebox and, further, recirculate about an equal quantity of extremely hot gases already in the firebox, and in the nozzle, mix them intimately with the incoming atmospheric air. It will also be observed that by reason of the nozzles projecting far enough into the firebox, they are sufficiently heated so that they always maintain a relatively high temperature. At the same time, it will be observed that as the gases generate in the firebox and are moving rearwardly and upwardly around the rear end of the baflle l8, a substantial portion are passing through the perforations 22 in the baffie, dividing the gases into many fine streams which together with the sharp jets directed from the nozzles on the opposite sides of the firebox intimately mix the various fuel gases and create a violent turbulence therein which results in practically complete combustion by the time they reach the boiler tubes l8 of the locomotive boiler. This method of creating a violent turbulence and intermixing of the fuel gases within the firebox and supplying additional oxygen and atmospheric air, practically insures a complete combustion of all of the gases and reduces the amount of waste of fuel to a minimum.

While in the above specification I have described one embodiment which my invention may assume in practice, it will of course, be understood that modification may be made without departing from the spirit and scope of the invention as expressed in the following claims.

What I claim is my invention and desire to secure by Letters Patent is:

1. The combination with a locomotive boiler including a firebox adapted to burn solid fuel, of a baffle mounted in said firebox having a plurality of perforations therein for permitting a substantial portion of the gases from burning solid fuel to pass therethrough, a plurality of nozzles extending through the walls of said firebox projecting a substantial distance therein, certain of said nozzles located forwardly and certain other of said nozzles located rearwardly of said baffle, a steam pipe line connecting said boiler with said nozzles for furnishing steam under pressure thereto, a manually controlled ejector for introducing a predetermined amount of hydro-carbon oil into said steam pipe line, and means adjacent each of said nozzles for introducing atmospheric air around said nozzles and mixing it with the steam and atomized hydro-carbon oil and discharging the mixture through said nozzles so as to set up a violent turbulence of the gases on the opposite sides of said baffle.

2. The combination with a locomotive boiler including a firebox adapted to burn solid fuel, of an upwardly and rearwardly arched baffle mounted in said firebox having a plurality of apertures therein for permitting a substantial portion of the gases from burning solid fuel to pass therethrough, a plurality of spaced apart nozzles extending through the side walls of said firebox and extending thereinto, certain of said nozzles located above said baffle and certain other of said nozzles located below said baffle, a steam pipe line for furnishing steam under pressure from the boiler to said nozzles, a manually controlled ejector for delivering a regulated amount of hydro-carbon oil to said steam pipe line, means for introducing atmospheric air to the firebox around said nozzles, and means for drawing a certain portion of the gases within said firebox into said nozzles and mixing said last named gases with said steam, hydro-carbon oil and atmospheric air and discharging the mixture so as to set up a violent turbulence within said firebox.

3. The combination with a locomotive boiler including a firebox adapted to burn solid fuel, of a bafile mounted in said firebox having a plurality of perforations therein for permitting a substantial portion of the gases from burning solid fuel to pass therethroug h, a plurality of nozzles extending through the walls of said firebox and projecting a substantial distance therein, said nozzles located forwardly and rearwardly of said bafile, a steam pipe line connecting said boiler with said nozzles for furnishing steam under pressure thereto, a manually controlled three-way ejector valve for introducing a predetermined amount of hydro-carbon oil into said steam pipe line, and means for introducing atmospheric air around said nozzles and mixing it With the steam and. hydro-carbon oil discharged from said nozzles and discharging the mixture through said nozzles so as to set up a violent turbulence of the gases on the opposite sides of 10 said bafiie.

SAMUEL M. DARLING.

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