US1306017A - maynard and p - Google Patents

Description

E. A. MAYNARD AND P. STANFIELD.

FURNACE.

APPLICATION FILED SEPTA, 19m.

1 ,306,Ql7. Patented June 10, 1919.

2 SHEETS- SHEET I.

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E. A. MAYNARD AND'P. STANHELD,

I FURNACE.

APPLICATION FILED SEPT.4.191B.

1 306,0 1 7., Patented Julie 10, 1919.

2 SHEETS-SHEET 2.

0 pw Jfanf/e/d FEED STATES PATENT @FFEQE.

FURNACE.

Specification of Letters Patent.

Patented June 10, 1919.

Application filed September 4, 1918. Serial No. 252,544.

To all whom it may concern:

Be it known that we, ENNIS ARTHUR MAY- NARD and PERRY STANFIELD, citizens of the United States, both residing at Whittier, in the county of Los Angeles, State of California, have invented new and useful Improvements in Furnaces, of which the following is a specification.

This invention relates to furnaces particularly adapted to burning fluid, gaseous or other fuels. Our invention is particularly efficient as applied to fluid or gaseous fuels; and so, in the following described specific embodiment of the invention, we explain a specific form of gas furnace.

It is a primary object of the invention to provide a form of furnace in which eflicient combustion may be carried on, and by which the maximum amount of effective heat may be produced by the burning of a given amount of gaseous or other fuel; and to effectuate this object it is an object to provide an efficient means for heating the air which supports the gaseous or other combustion. This means involves primarily the use of heating tunnels through which the air passes under the floor of the furnace; the air being thus heated by heat which is otherwise conducted or radiated away from the furnace and usually lost. Means are provided to cause the air to be effectively heated by the gaseous flame; and the total result is that the flame and combustion are of much higher efiiciency than is usually possible.

In the drawings we have illustrated two typical forms of furnace, in accordance with our invention, being furnaces adapted to different types of boilers; but it will readily be understood that our furnace may be applied in any situation, by suitable modifications or variations. In these drawings Figure 1 is a longitudinal vertical section of one formof our furnace as applied to a water-tube boiler; Fig. 2 is a horizontal section on line 2-2 of Fig. 1; Fig. 3 is a cross-section on line 33 of Fig. 1; and Fig. 1 is a horizontal section similar to that of Fig. 2 showing a modification of the furnace applicable to tire-tube boilers.

Referring first to Figs. 1, 2 and 3: We show therein a furnace structure which embodies side walls 10; front wall 11 and rear wall 12, with an intermediate wall 13 which forms the forward wall of the smoke box at the rear end of the furnace. The boiler tubes 14 set over the front wall 11 and over the intermediate wall 13; and the furnace structure proper is located between these two walls 11 and 13. On the floor 15 of the furnace (such floor may be of any suitable material) we erect a number of longitudinal partition Walls 16 (say three in number) and on these walls there is supported an upper furnace floor 17 which is preferably made up of two courses of fire clay slabs or blocks laid clear across the furnace from side to side. This upper furnace fioor forms, with the longitudinal wall 16, a plurality of air passages 18. The floor 17 does not extend clear to the front wall 11 of the furnace,'but stops short of the front wall as do also walls 16; and blocks or slabs 19 may be laid on the forward edge of floor 17 and over the space between the forward edge of floor 17 and the front wall of the furnace, leaving openings 20 directly under the as burners 21; so that the heated air from the passages 16 will come up directly under the gas burners. The doors 22 and 23 on the furnacefront are made so as to be practically alr-tight, and the floor 17 is formed in such a manner as to be air-tight. The blocks of which the floor is formed may be set in or plastered over with a cementitious clay (a fire-resistant material); and the side walls 10 and walls 11 and 13 of the furnace are coated on the inside with a plastering of this clay so as to make the whole of the furnace structure practically air-tight and allow no ingress of air from below except through the openings 20. In order to allow for expansion and contraction, the floor 17 is not laid quite tight at its edges against the walls 13 and 10, but a small space is left which is filled with sand asis indicated at 25. This filling of sand makes an air-tight joint and at the same time allows for expanslon and contraction. Such filling need not neces sarily be used at the back edge at wall 13; the open space at the front providing for expanslon.

The description so far given is applicable to both the forms of furnace shown in the drawings; the major difference between these two forms being the method in which air is inducted to the passages 18. For the watertube boiler the air is taken in through side openings 30 in side wall 10. These openings communicate with passages 31 which, in the present construction, are preferably two in number, one passage 31 feeding the two passages 18 on the far side of the furnace, and

the other passage 81 feeding the two passages 18 on the near side of the furnace. At the entrance to each pamage 13 there may be a projecting wall part 32 which partially restricts the entrance to the passage 18; and the flow of air into the passages is controlled by damper doors 33 which may be.

raised to make any size opening desired.

Now in Fig. 4 (for the fire-tube boiler) the passages 18 extend clear to the rear wall 12 of the furnace; and in the rear wall there are inlet openings 80 controlled by damper doors 33 each door and each opening 80 serving two passages 18", as indicated.

On the upper furnace floor 13 we lay one or more baffle walls 40 composed of brick checker work. These walls are preferably laid on a curved line across the furnace and stand in about. the relation to each other which is illustrated in the drawings. They do not extend clear up to the tubes of the boiler; and their oflice is to break up and spread out the gaseous flame so as to keep it from shooting directly through the furnace, spreading it out in such a manner as to get most effective contact of the flame with the boiler. At the same time this brick checker Work has the effect of spreading the flame out over the floor 17 so as to obtain a more efficient application of the heat to the floor, and so as to most efficiently heat the air passing through the passages 18 under that floor. The size and capacity of the passages is such that the air necessary for the operation of the furnace may flow relatively slowly through the passages, so as to have asufiicient time in which .to be come heated. We have found in one installation that if air is admitted at the openings 30 at 95 F. it will, in such a construction as shown in Fig. 1, emerge at the openings 20 at about 150 F.; and we have found that the efficiency of combustion due to this preheating of the air in this manner is in creased by about ten to twelve per cent. The comparatively eool incoming air, under the false floor, acts as an insulating medium to keep the lower floor cool, because this air takes up the heat which would otherwise heat the floor. This is an important aspect of the invention as applied to marine boilers.

Having described a preferred form of our invention, we claim:

' 1. In a furnace construction, a furnace comprising side and front and rear walls and a floor, a false floor over the furnace floor, longitudinal walls supporting said false floor and forming beneath that floor a plurality of air passages, means to induct air to the rear ends of said passages, there being openings through the false floor near the front wall of the furnace, so that air flows forwardly through 'said passages to enter'the furnace, burnersprojecting through the front wall of the furnace over said openings, and brick checker work walls extending across the furnace above saidfalse floor at a point somewhat rearwardly removed from the front end of the furnace and adapted to spread the flame from the burners over the floor so as to efliciently heat the floor and the air passing through the passages beneath it.

2. In a furnace construction, a furnace comprising side and front and rear walls and a floor, a false floor over the furnace floor, longitudinal walls supporting said false floor and forming beneath that floor a plurality of air passages, means to induct air to the rear ends of said passages, there being openings through the false floor near the front Wall of the furnace, so that air flows forwardly through said passages to enter the furnace, burners projecting through the front Wall of the furnace over said openings, and brick checker work walls extending across the furnace above said false floor at a point somewhat rearwardly removed from the front end of the furnace and adapted to spread the flame from the burners over the floor so as to efficiently heat the floor and the air passing through the passages beneath it; said means for inductingair to the rear ends of said'passages embodying separate and independently controllable induction openings feeding the several air passages,

3Q In a furnace construction, a furnace comprising side and front and rear walls and a floor, a false floor over the furnace floor, longitudinal walls, supporting said false floor and forming beneath that floor a plurality of air passages, means to induct air to the rear ends of said passages, there being openings through the false floor near the front wall of the furnace, burners over said openings, said false floor ending at its edges a little short of the side walls of the furnace, and a filling of sand in the space between the edges of the floor and the side walls to make an air tight joint between the floor and the side Walls.

4. In a furnace construction, a furnace comprising side and front and rear walls115 and a floor, a false floor over the furnace floor, longitudinal walls supporting said false floor and forming beneath that floor a plurality of air passages, means to induct air to the rear ends of said passages, there being openings through the false floor near the front wall of the furnace over said openings, said false floor ending at its edges a little short of the side walls of the furnace, and a filling of sand in the space between the edges of the floor and the side walls, said furnace walls and upper floor being air tight so that no air may enter the furnace 5. In a furnace construction, a furnace comprising side and front and rear walls and a floor, a false floor over the furnace floor, said false floor being composed of a plurality of courses of floor slabs laid in staggered relation on one another so as to shut off passage of air through said floor, openings through said floor through which air may flow to the furnace chamber above, means to induct air into the space below said false floor, said false floor ending at its edges a little short of the side walls of the furnace, and a filling of a loose finely divided material in the space between the edge-s of the floor and the walls of the furnace; so that the false floor is air tight and its juncture with the furnace Walls is air tight.

6. In a furnace construction, a furnace comprising side and front and rear Walls and a floor, a false floor over the furnace floor, inclosing an air passage space over that floor, there being openings through the false floor near the front wall of the furnace, burners over said openings, means to induct air to the rear end of said air passage space so that air entering the furnace passes forwardly through the passage space, and a checkerwork wall extending across the furnace above the false floor at a point between said forward openings and the rear end of the false floor and adapted to spread the flame from the burners over the floor to heat it and the air passing beneath it.

In witness that we claim the foregoing we have hereunto subscribed our names this 26th day of August 1918.

ENNIS ARTHUR MAYNARD. PERRY STANFIELD.

Witness VIRGINIA I. BERINGER.

Copies of this patent maybe obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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