US1737003A - Sectional furnace - Google Patents

Description

Nov. 26, 1929. J. DOHERTY SECTIONAL FURNACE Filed March 21, 1923 ..mvlzxlllllllllllllllmllllIIIIII INVENTOR A TTORNEYS Patented Nov. 26, 1929 UNHTED STATES PATENT p, @FFEQE JAMES DOI'IERTY, OF CHICAGO, ILLINOIS; ELLA MAUI) DOHERTY AND JAMES RUSSELL DOI-IERTY EXECUTORS OF SAID JAMES DOHERTY, DECEASED SECTIONAL FURNACE Application filed March 21, 1923. Serial No. 626,486.

My invention relates to a sectional furnace of known type, which is made up of an assembled series of hollow water-containing sections and in which it is sought to procure a complete combustion reaction and to render the furnace smokeless by the introduction of heated auxiliary air, the structure and objects thus generally recited being'familiar in this art.

My invention consists in an improved and simplified construction for bringing about these results in the most effective manner and which can be incorporated in furnace design at low cost and without requiring complicated casting operations for any of the furnace sections. More particularly the invention consists in air delivery means situated at the throat, i. e. the firegas opening leading out of the firebox, and constructed in such fashion that it substantially encircles said opening and delivers the air crosswise into the fire gas flow therethrough. In the furnace in which my invention is embodied, the front sections form the firebox, the sections in rear thereof form the rear firebox wall and rear flue space and all of the sections provide overhead lines, as customary.

Referring to the drawings:

Fig. l is a side elevation of a furnace embodying my invention and in which the side walls of the assembled sections are in part broken away to show internal structure in section.

Fig. 2 is an elevation of the section forming the rear of the firebox, parts of the air delivery box being shown in section.

Fig. 3 is a section on the line III-III of Fig. 2 looking in the direction of the arrows, and

Fig. 4 is a detail perspective showing the interior of the air distributing and delivery box.

The furnace thus illustrated is made up of a series of cast, hollow, water-containing sections 1 bolted together in the usual way and supported by side base members 2 connected at the front and rear of the furnace by transverse plates 3 and 4t and by an intermediate divisional plate 5 constituting the rear wall of the ash pit, Usual doors and dampers are carried by the front plate 8. The several sections are provided with aligned spaces forming the firebox 6, rear flue space 7 overhead return side fiues 8 and central escape flue 9, the flow of gases being as indicated by the arrows.

The front section 1 is provided with the usualfuel feed door 10 and flue clean-out doors 11, which permit access to all the overhead fines. The throat section, designated as l". constitutes the vertical rear wall 12 of the firebox, which is hollow and water-containing, and extends downwardly to a unction with the base plate 5 or at least below the fuel bed. In this wall, preferably relatively near its top, is the throat or transverse fire gas opening 13 leading from the firebox 6 to to the rear flue space 7, and in association with which I locate the improved means for distributing and delivering auxiliary air to the firegas flow. This means forms a border for the throat and in its preferred form completely encircles the same, being constituted of an open sided metal box-like structure 14 having air-delivery openings 15 and attachment lugs 16. It is preferably formed in two similar or identical parts or halves, as shown, which may be either cast or pressed of sheet metal, and which when secured or bolted against the forward face of the water-containing bridge wall 12, as indicated in the drawings, form a loop-shaped air passage with its series of outlets 15 opening inwardly or toward the fire gas flow through the throat. As thus mounted the openings 17 at each end of the loop register with recesses or notches cast in the adjacent sides of the section 1*, constituting entrances for air to the box dimet from atmosphere. Preferably, these entrances are equipped with thimbles or bushings 18 which are provided with dampers 19 to control the air admission. It will be understood that the main supply of combustion supporting air is through the perforated grate and fuel bed thereon, and that the air entering by way of the means just described is auxiliary thereto, and is heated by its contact with the air box 14:, which has imperforate metal wall structure projecting forward from the bridge wall into the fire flow to the throat to present said imperforate wall structure thereto to be heated thereby, the air delivery means of the box being located beyond this imperforate wall structure in the direction of fire gas flow so that when the air is delivered and mixed with the firegases in the throat 13 it is at a proper temperature to combine with and burn the unconsumed fuel therein and thereby produce the; smokeless results desired. of the metal box 14 with the water cooled wall tends to keep it at a safe temperature. lhe most of the auxiliary air is delivered clownwards and upwards, and all of it crosswise to the fire gas flow, it being desirable, to restrict or graduate the exits 15 so that the distribution is substantially uniform from one side of the throat to the other. l Vhilc the structure of air box, above describedis pre ferred, because of its simplicity and effectiveness, itwill beunderstood that the advantages of the invention may be obtained by the use of other forms, similarly mounted or located.

The formation of the box l l in two parts is found to be of great convenience in assembling and in replacing, since in most cases the individual parts can be removed (through the fuel feed door when the entire structure, if made, in onepi'ece, could not be removed without disassembling the entire furnace, The box and the bushings 18 are made and mounted independent so'that the box halves, or either of them, may be installed or removed without disturbance of, or v restraint from, either busning. Of course, also, the two-part construction of the box lowers the cost of manufacture, since the parts are identical and can be madein, the same, dies or cast from the same patterns,

I claim;

1. A, sectional furnace made up of an as.- sembled series of cast hollow water-containing sections having aligneo openings which constitute a firebox and fine space in rear thereof and in communication therewith, a water-cooled bridge wall formingthe rear wall of the firebox andlhaving an opening constituting the water-cooled throat, through which the fire gases pass from the firebox to the flue space, and an air d livery box located in the firebox in front of the front water-cooled face of said bridge walhenclosing saidopening in the bridge wall and constructed to receive and 'to deliver air around said opening to the entering current of fire gases passing there through.

2. 'A sectional furnace made up of "an assembled series of cast hollow water-containing sections having aligned openings which'constitute a firebox and flue space inrear thereof and in communication therewith, a watercooled bridge wall formingthe rear WilllfO'f the firebox and having an opening constitutthe water-cooled throat through which the fire gases pass fromthe firebox to the flue At the same time the contact space, and an air delivery box adjacent said throat and exterior thereto and consisting of an air conduit having an otherwise open side closed by a vertical watencooled Wall of the bridge. wall section and means to deliver auxiliary air from said conduit to the fire gas flow.

3. A sectional furnace made up of an assembled series of east; hollow Water-con: taining sections having; aligned openings which constitute a firebox and flue space in rearmthereof and in communication therewith, a water-cooled bridge wall forming the rear wall of the firebox and having an opening constituting the water-cooled throat through which the fire gases pass from'thc fireboxto the flue space, and an air box made in two sections and having its rear side open, secured-tothe front of the bridge wall adj acent saidthroat with itsopen side against the water-cooled bridge wall, and each of which, sections, may be put in-place or removed independently of the other, said sec tions, each having in its fire-gas-contacted walls facing respectively the under side and the upper side of the fire gas flow air deliveryopenings and constituting together means for delivering air upward and downward athwart the current of fire gases passing through said box and. waterecooled throat;

4. In a sectional furnace, a metal air delivery box of loop form for enclosing a fire gas flow: space and having air delivery openings in its inner wall which is posi tioned tobe contactedby fire gases and to face the fire gas flow through i't, said box being provided with air inlet} openings and being also open atone side next said inner wall," and havingmeans f0r attachment to the wallof a furnace section withits open side against the same.

5. A sectional furnace made up of an assembled series of, cast, hollow watercontaining sections, having aligned openings which constitute a firebox andflue space in rear thereof 1 and in; communication therewith,-a water-cooled bridge wall forming the rear wall of the firebox and havinganopening constituting the water-cooled-- throat through-which thefire gases pass from the firebox to thefiue space and a separately made air delivery boxclamped to the bridge wall and having its fire-gas-contacted-inner Walls in substantial registry with the watercooled throat and havingone set of openings positioned to admit air from the atmosphere to the box and another set of openings positioned to deliver air throughsaid inner walls at intervals to said throat opening athwart the current of gases passing theret-hrough.

6.A sectional furnace made up of an assembled series of cast hollow water-containing transverse sections having-aligned openings constitutinga-firebox and fiue space in'rearthereof and in communication therewith, one of said sections being a transverse water-containing bridge wall section having in its upper part a flue opening and beneath the same a water-containing portion extending to a transverse water cooled firegas contacted throat through the section, and a separately made air delivery box extending transversely along the bridge Wall adjacent the throat and having imperforate metal wall structure projecting forward from the bridge wall into the fire gas flow to the throat to present said ilnperforate wall structure thereto, said air delivery box having beyond said imperforate wall structure in the direction of fire gas flow means for delivering air to the fire gas flow through the throat.

In testimony whereof, I have signed this specification.

JAMES DOHERTY.

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