US156208A - Improvement in steam-generating furnaces - Google Patents

Description

UNITED STATES PATENT OFFICE.

GEORGE W. CUMMINGS, OF CLEVELAND, OHIO.

IMPROVEMENT IN STEAM-GENERATING FURNACES` Specification forming part of Letters Patent No. 156,208, dated October 27, 1874 application led i v September 16, 1874.

' ous products in the fire-boxes or furnaces connected with steam-boilers.

The nature of my invention consists in supplying the incandescent coals and the gases arising therefrom with oxygen from air and steam introduced into the lire-box above the furnace-door, and pure air introduced into the lower part of the dame-bed, back of the bridgewall, and vat one ,or more points between said bridge-wall, and alongthe dame-bed between the furnace and the rear end of the boiler, in such manner that the large quantity of air introduced and necessaryto complete combustion shall not operate as a cooling` medium, but shall rather augment the heat, andthereby increase the evaporation going on in the boiler with the same-or a lesser quantity of fuel and the suppression of smoke.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

rIhe boiler being constructed in any of the known forms, I introduce a current of air to the fuel and flames in the iirebox or furnace `iiue, and said pipe or flue extends laterally acrossthe name-bed and through both side walls of the easement, so that, the ends being open, the air from the outside of said re-box or easement may have free access to the gases as they pass the bridge-wall on their Way to the iiues of the boiler and the chimney. At one or more points between the first-described perforated tube or flue and the rear end of thel boiler I introduce one or more perforated pipes or iiues, extending laterally across the iiamebed and through the side walls of the casement, open at each end to admit the air freely from. without, as in the case of the iirst perforated pipe or flue behind or near the bridgewall. The object of this arrangement of the tubes, or pipes, or iiues is, thatthe :first pipe or ue over the furnace-doors or along or within the sides of the easement or fire-box may, by admitting air to the gases arising from the combustion of the fuel within said re-box or furnace, thoroughly mix said gases, and by supplying said gases at the same time with oxygen from the air so introduced initiate the combustion 4of said gases, and as the products of said combustion pass over the bridge-wall in a highly-heated state a further supply of oxygen is added, and as the flame progresses toward the rear of 'the boiler it receives still further supplies of oxygen to support the com-V bustion in'like manner through the perforated pipes or iues communicating with the atmosphere without said easement, and thus the combustion is continued until completed.

I perforate the flues or pipes IJ on top and one side for the following reason, viz., that when the draft from the chimney, which is always more or less variable, shall. cause the4 currents of air, gas, or vapors from the iirebox to pass over the top of said perforated pipes or flues so rapidly as to overcome the atmospheric pressure from without the easement or fire-box, thereby in effect corking up said top apertures, the side apertures will supply the requisite quantity of air, for the purpose heretofore stated.

Reference being had to the accompanying drawings, it will be seen that Figure 1 is a plan view of my invention applied to an ordi nary fire-box or furnace under a steam-boiler,

the boiler A being removed, in order that an unobstructed View may be had. C represents the grate-bars; E, perforated pipe or chamber over the fire-doors; f, perforated steam-pipe;

G and G,'perforated pipes or chambers in the sides of the fire-box or easement; I, pipe or 'flue behind the bridge-wall, perforated on top be several, at or near the rear end of the casement, and beneath the boiler.

Fig. 2 is a longitudinal Vertical section of the lire-box or furnace and boiler with my apparatus attached, A being the boiler; B, firebox; C, grate-bars; D, ash-pit; E, perforated pipe or chamber over fire-doors; G G', similar perforated pipes or chambers along the sides of the easement; f, perforated steam-pipe Within the chamber E and the side chambers G G H, bridge-wall; I, perforated pipe or flue behind bridge-wall J perforated pipe or flue in rear of easement, and at convenient distances between the bridge-wall and the rear end of the boiler.

I prefer to make the perforations in the air pipes or flues about half an inch in diameter, and to place them about one and one-half inch apart from center to center.

The steam -pipe j' passes from the boiler through the iiue or chamber E, and may also be made to extend down the side tlues or chambers G and G. That part of it inclosed in the .iues or chambers E and G and G is perforated along the inner side, and both ends of the ue or chamber E being open, the steam escaping through the perforations in the steampipe f into the said-air iue or flues, and thence through their perforar-ions intovthe fire-box, draws in a current of air, which passes into the flreboX with the steam.

' In lieu of the perforated pipes or flues I J, and as the equivalent thereof, a similarly perforated horizontal plate may` be ,introduced into the ame bed or chamber back of the bridge-wall, and extending from said bridgewall baclrto the rear end of the boiler, and from side to side of the easement, forming a perforated door under the flame-bed and a little below the bridge-wall, through which air will be introduced to the ame behind the bridge-wall from the chamber below said floor. In such case there must be sufficient openings in the sides of the easement to admit air under said perforated ioor; and these openings may be provided with regulating-Valves, to control the admission of air.

The perforations in the steam pipe f discharge through small nipples i, which coincide with the somewhat larger perforations in the inner wall ofthe chamber E, as shown on enlarged scale in Fig. 3.

I do not introduce steam into the fire-box under the supposition that the steam actually burns; but I employ the steam-pipe f simply as a blower, for forcing air into the fire-box, and disseminating and mixing it with the gaseous products of combustion arising from the burning fuel.

I deem it essential that the air introduced back of the bridge-wall be introduced below the top of said wall, in the lower part of the flame bed, at a point near said bridge, and also at one or more points between the point last mentioned and the rear end of the boiler.

I am aware that an attempt was long ago made to improve a furnace by introducing superheated steam mixed with hot air into the fire-box, and hot air unmixed with steam into the flame-flue, just back of the bridge-wall, immediately under the boiler, and above the Haine-bed, through perforated pipes, and that va patent was granted to one C. Buckhardt,

June 5, 1849, on a furnace constructed to effect said object. I do not therefore claim, broadly, introducing air and steam into the fire-box, and pure air into the flame-bed or iue back of the bridge-wall through perforated pipes; but

A perforated air-due above the furnacegrate inclosing a perforated steam pipe, provided with nipples, as described, for blowing air and steam into the ireboX, in combination with perforated air-fines below the top of the bridgewall, and between it and the rear end of the boiler, for introducing pure air to the lower portion of the flame-bed, all being constructed, combined, and arranged to operate substantially as described.

G. W. CUMMINGS.

' Witnesses J. J. CooMBs, J. L. GooMBs.

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