US1073039A - Boiler-furnace. - Google Patents

Description

G. DE GRAHL.

BOILER FURNACE. APPLIOATIQN FILED K0120, 1911.

1,073,039. Patented Sept. 9, 1913.

1 2 SHEBTS SHEBT l.

Patented Sept. 9, 1913.

2 SHEETS-SHEET 2.

Fig.5.

UNITED srATr.

S PATENT OFFICE.

GUSTAV DI GBAHL, OI ZEHL'RNDORF, NEAR BERLIN, GERMANY.

roman-rename.

Specification of Letters Patent.

. .Applieationmed November 20, 1911., Serial No. 661,352.

' PatentedSept.9,191-3 To all whom it may concern Be it known that I, GUSTAV on Grmrin, a subject of the German Emperor, and residing at Zehlendorf, near Berlin, Germany,

have invented a certain ncwand useful Improvement in Boiler-Furnaces, of Whichthe following is a specification. My invention relates to methods, of auto-. matically admitting overgrateblasts. into fire-boxes, and to apparatus for carrying the same into practice.

l/Vhen overgrate blast was admitted into the fire-box heretofore, it Wasfrequently diflicult for the under-grate blast to pass through the grate, this being due, for example, to the grate having been charged too thickly or to low-grade coal. In all cases when the passage of the undergrate blast through the grate is impeded, the admission of the overgra-te blast, on the-contrary, is accelerated while being drawn in, so that the conditions are such as to favor the cooling of the fuel on the grate and the formation of dead places, that is places where the fuel is not properlyburnt through.

A primary object of my invention is to obviate this defect. To this end I provide that the section of the passage admitting the overgrate blast is automatically reduced-both in proportion as the passage of the under grate blast through the grate is rendered difficult during the main blast and as the velocity of admission of the overgrate blast into the fire-box is conse uently increased. and, also according to the initial velocity of the overgrate blast.

By restricting the passage for the overgrate blast the conditions are renderedfavorable for drawing the undergrateblast through the grate. Consequently, the object of my method is automatically to restrict the admission of the overgrate blast or; to cut it off completely assoon asit detrimentally 'alfects the process of combustion and thus favorably to influence the passage of the undergrate blast through the grate.

The apparatus substantially consists in the conduit which not only admits the supplementary air or overgrate blast and opens into the fire-box, but is alsoprovided with a valve opening inward being so constructed, for example, by the addition of a projection, rib or the like, that the valve constricts the free section of the passage for the supplementary air as it opens beyond a certain amount and approaches the limit of its travel.

In order to vary the restriction of the passage to suit the coal burned at any time and, particularly, to prevent the passage for the overgrate blast being restricted too much when the coal develops a great deal-of smoke, I, provide an adjustable stop for the valve. The valve may, for example, be so adjusted that when using) steam coal the passage for the overgrate last is almost completely closed owing to the velocity at which said blast enters, whereas for coal developing much soot it is only slightly restricted or not at all. One for m of apparatus according tomy inventlon is represented by way of example in the accompanying drawings, wherein Figure 1 is a front elevation of a fire-door frame having an inwardly opening fire-door, Fig. 2 a front elevation, partly in section, enlarged, showing a portion of the fire-door frame, and Fig. 3 is a horizontalsection on the bent line AB in Fig. 2. Referring to the drawing, 1 designates the door frame provided with two lateral airconduits 2, 3. I Each of these has an enlargement 4, 5 respectively, which is separated by a projection or rib 6, 7 from the upper portion of the air-conduit. In each of said lateral air-conduits there is an air valve 8, 9 mounted on a pivot 10, 11, respectively. On the wall of each lateral air-conduit is fixed a segment 12, 13, connected by arms 14, 15 with a sleeve 16, 17. Each of the latter extends through the wall of. the lateral air- conduits 2, 3 above the valves and serves for the reception of a revoluble pivot 18 which carries on the end projectin into the lateral air-conduit a lever 19 actlngas a. stop for the valves, and on the other end a lever 20. Each lever 20 carries a handle 21 having a recess 22 (Fig. 3). Thespring 23 in each recess 22 acts against thehead 24 of the pointed pin 25. The pins are displaceably mounted in the handles 21 and are provided with nuts 26.

The segments 12, 13 each possess a series of notches or holes 27, 28 inwhich the pointedends of the heads 24 can rest. The levers 19, 19- are provided with springs 29, 30 which serve as resilient stops for the valves 8, 9. The position of each lever 20 with regard to the valves 8, 9 is such that as soon as the head 24 engages in the lower- 'a minimum amount,

most hole 27 or 2%,thc lever 19 formingthe stop for the valve allows the valve to open just sufficient to cool the furnace front. Atter steam has been shut ofi' from the engine and after the main blast has ceased, the resilient stops for the valves 8, 9 are adjusted according asthe auxiliary blast is set more oi iless in action,

' the arrangement being such that even when the valves. have opened awcomparatively small amount there is a comparatively large opening for the overgrate blast passing through the air-conduits. If, after the auxiliary blast is shut off the main blast is started, in case the passage of the undergrate blast through the grate is rendered difficult in consequence, for example, of the grate being too heavily charged and the velocity of the overgrate blast passing.

I to appear on the grate, their appearance being always a proof that insufficient undergrate air is passing through the grate into the space above the grate. In this case main, in consequence of the great velocity 0? the over-grate blast passing through the air- conduits 2, 3, the air-valves 8, 9 automatically adjust themselves in such manner that the admission of overgrate blast is impeded and consequently dergrate blast through the grate favored. Should the one side of the grate be more choked or stopped up than the other, so that overgrate blast is drawn'in to an increased extent at this choked up side and combustion consequently takes place more slowly at said side, the automatic regulating action described above will take place 'only in the case of that valve which is situated at said side of the furnace.

For short flaming coal which tends to develop smoke only slightly, it is preferable to set the levers 19 provided with the stops for the valves in such a manner that the valves occupy the upper position indicated in Figs 2 as soon as they bear against'the resilient stops. In this case the passage for the overgrate blastis materially restricted. In proportion as the coal tends to develop soot such a position should be given to the lever 19 that the restriction is less. The

the passage of un-.

above described device is ithus such? that,

each kind of coal, it enables the passage ror the oye'rgrate blast to be adjusted automatically.

I clai'm V after the levers 19 have been suitably set for 1. "Apparatus for automatically control-=- ling the fire box of the furnace, comprising in the admission of overgrate blast into combination, a suction copduit for the overgrate blast open at one nd tot-he'outer atniosphere and at the otherendto the'fii'e box rib extending through the suction and being said conduit being provided with an internal immovable 1n the same, thus narrowing the said conduit, and a. valve in said conduit opening toward the fire boxadapted to approach said rib and restrict the'passage for the overgrate for said valve.

2. Apparatus for automatically com r blast, and an adjustable stop ling the admission of over-grate blast into I the fire box of the furnace, comprising in combination, a suction conduit for'the overgrate blast open atone end to the outer atmosphere and at the other end to the fire box said conduit being provided with an internal rib extending through the suction conduit and being immovable in the same, thus narrowing the said conduit, and a valve in said conduit opening toward the fireq box adapted to approach said r ib and restrict the passage for the over-grate blast, and an adjustable resilient stop for said valve. N

8. Apparatus for automaticallyi'controlling the admission of overgrate blast into the fire bOXJPi a furnace, comprising in combination,,a'-'suction conduit for the overgrate blast open at one end 'to 'theouter atmosphere and vat the other end to the fire box, said conduit being provided with an inwardly projecting rib, a chamberbetween said rib and the atmosphere, a pivoted valve mounted in said conduit on the atmosphere side of said chamber, said valve being adapted to close said conduit when no air is passing therethrough andto swing through .7

said chamber toward said rib under the influence of an increasing suction whereby said condult 1s first opened and then restricted as the valve moves toward said rib, and an adjustable stop for limiting the movement of said .valve toward said rib.

In testimony whereof, I atfix signature.

in the presence of two witnessesia v U AY? be .GRVAHL: 1

Witnesses:

HENRY HASPER, WOLDEMAR HAUPT.

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