US1888804A - Heating apparatus and method - Google Patents

Description

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HEATING APPARATUS AND METHOD File Mag" 8, 1929 2 Sheets-Sheet Nov, 22, 1932. NASH AL 1,888,804

HEATING APPARATUS AND METHOD Filed May 8, 1929 2 Sheets-Sheet 2 f fH'HHTfffffff/fff/ff 9 4, 4t 65 '.i. K 68 9 a5 I 4 1 aa6 i A 1 23% Fer-tented Nov 22,, 1932 ARTHUR E. NASH, 0F PHILADELPHIA, AND JAMES S. ALCORN, ()F CYNWYD, "FENBTSYTIQ VANIA, ASSIGNORS T0 ALCORN COMBUSTION COMPANY, OF JPMLADELFHIA, PENN- SYLVANIA, A CQRIPURATIQN 012" DELAWARE HEATING APPARATUS AND TIZJE'J'LE JOD Application filed May a 1929. Serial No. 3 1,290. I

Our invention relates to heating systems, and more particularly to asystem for generatin g heat by com ustion for furnaces, heating systems, and t e like, in general, and more particularly for oil stills, steam generators and the like.

In accordance with our invention fuel, in the form of gas, vapor, liquid or finely divided solids, is delivered under pressure from nozzle structure or equivalent to produce a jet or jets operating as a motive fluid for ontraining combustion-supporting air whose pressure is raised by injector or e]ector operation or aspiration and delivered with and by the fuel jet into a combustion zone or chamber comprising a nozzle passage in which the air and fuel are intimately mixed and the fuel largely burned; and preferably the gases soon after their discharge from the nozzle-like combustion chamber and before they impinge upon the heat absorption strucinduction of the combustion-supporting air is wholly or substantially wholly independent of orwithout reliance upon the stack draft Which is utilized only for carrying off products of combustion after they shall have completed their course through the heating system or furnace.

Further in accordance with our. invention the combustion-supporting air induced by the burner jet'action is drawn either directly from the atmosphere, or from the atmosphere through a preheating system.

Our invention resides in a system and in features of construction and arrangement of the character hereinafter described and claimed.

For an understanding of our invention and for an illustration of several of the various forms our structure may take, reference is to be had to the accompanying drawings, in which:

Fig. 1 is a vertical sectional view, parts in elevation, of structure embodying our invention. J

Fig. 2 is a horizontal sectional View, parts in plan, taken on the line 22, Fig. 1.

Fig. 3 is a vertical sectional view taken on the line 33 of Fig. 1.-

Fig. 4 is a vertical sectional View, parts in elevation, illustrating a modification of our structure.

Fig. 5 is a vertical sectional view, partly in elevation, taken on the line 5-5 of Fig. 4.

Fig. 6 is a fragmentary horizontal sectional view illustrating structure similar to a part of that illustrated by Figs. 4 and 5.

Referring to Figs. 1 to 3 inclusive, 1 illustrates a floor or foundation of a furnace or similar structure having the vertical wall 2 surmounting the foundation wall 3.

lln the wall 2 is formed an opening 4:, constitutingan air or suction chamber, covered (Fill at its front by a casting or plate 5 itself provided with an air inlet opening 6 with which co-acts the cover or damper 7 pivoted at 8 and carrying the toothed segment 9 engaging the lower edge of the opening 6 to hold the member 'Z -in any suitably adjusted position.

The inner or furnace-chamber end of the air chamber 4: is closed in part by the pier l0 and the Venturi block or nozzle block 11 convergent nozzle passage 12 communicating, in

the example illustrated, immediately with the divergent nozzle passage 13, with which latter communicates the chamber -14 having refractory or fire clay Walls. The bottom wall is formed of slabs 15 lying upon the support 10. The sidewalls are formed of slabs or superposed elements 16, and the top by slabs or elements 17. In the example illustrated the chamber 14 may be of any suitable length, and ordinarily will be of the order of three or four feet long.

While the nozzle block or Venturi element 11 is illustrated as havingthe convergent divergent nozzle passages 12 and 13 communicating. directly or immediately with each other, it will be understood that between these convergent divergent portions may be a cyllindrical portion of any suitable length, constitutlng the throat which in the example illustrated however, is at 18 at the junction of the passages 12 and 13.

It shall further be understood that the nozzle or Venturi element 11 may have only a convergent passage, generally similar to 12, delivering into the chamber 14.

lit shall further be understood that whatever the structure of the nozzle or Venturi element 11, it may, in lieu of discharging into the short Combustion chamber 14, discharge directly into the furnace chamber G which lies to the right of the wall 2, and in or be- .yond which is located any suitable heat absorption structure, of tubular or any other form, containing the material to be heated, such as fluid, and particularly oil or petroleum to be distilled or cracked, or water to be converted into steam. Suitably positioned with respect to the inlet of the nozzle passage 12 is any suitable burner structure to which fuel, in any suitable form, is delivered under pressure and discharged into the nozzle passage 12 in the form of a jet, which operates as motive fluid to entrain combustion-supporting air drawn from chamber 4 and forced through the nozzle member 11, causing intimate mixture at high temperature of fuel and air which is promptly and rapidly burned to a state of substantially complete combustion before the gases are discharged to any considerable distance beyond the right end of the combustion chamber 14, Figs. 1 and 2, into the furnace chamber C. Or, in the ab sence of the chamber 14, when the gases are discharged directly into the chamber C their combustion is substantially complete before the gases have passed to a considerable distance into the chamber C. In either case substantially no unburned fuel reaches heat absorption structure in the furnace chamber C. When the chamber 14 is utilized it in effect constitutes a part of the, entire nozzle or Venturi structure, which is similar to a combining chamber, combining cone or diffuser of injector or ejector apparatus.

Presented to thenozzle passage 12 is the burner or nozzle 19 upon the end of the conduit or pipe structure 20 through which is delivered fuel in suitable form, more particularly oil, preferably atomized by steam, and in any event delivered undersuch pressure as to cause the fuel to issue as a motive fluidjet from the burner or nozzle 19. The steam, under any suitable pressure, for example of the order of pounds per square inch gauge, is delivered to the structure 20 through the-pipe 21, and is controlled by the valve 22. The oil enters by pipe 23 controlled by valve 24. The jet of fuel, or of oil and steam, issuing from the burner or nozzle 19 forms a high velocity/motive fluid jet which entrains air from the chamber 4, forcing it eeaeoa into the nozzle structure 11 at suitably high velocity. The fuel from the nozzle 19 and the air become rapidly intimately mixed at high temperature within the nozzle structure 11 and combustion takes place rapidly and substantially completely before the gases travel a substantial distance into the furnace chamber C in case the chamber 14 is materially shorter than described, or omitted entirely. In this connection it will be understood that the nozzle memberllmay itself be prolonged and extend a suitably short distance into the chamber C, when the structure forming the chamber14 is absent. In any event the nozzle passages 12, 13 and the chamber 14, which may diverge in continuity of divergent passage 13, may be considered as those of a single nozzle structure, or combining tube or venturi.

The combustion within the nozzle structure, which includes in most cases the short chamber 14, is rapid, due to intimate mixture of air and fuel at high temperature, and

there is discharged into the heating cham-' ber C a dame in which the balance of the unburned fuel is rapidly consumed, whereby the gases impinging upon the walls of the chamber (1 or upon any heat absorption structure which may be therein disposed, is devoid of unburned fuel, thereby avoiding injury to the walls or heat absorption structure otherwise occurring because of presence of substantial amounts of unburned fuel.

In addition to the nozzle 19, or, and preferably, associated therewith, is the annular nozzle structure 25 comprising the annular or manifold chamber 26 surrounding the central air passage or open space 27 within which is disposed the nozzle 19, when employed. Fluid in suitable form is delivered into the annular chamber 26. For example fuel gas is delivered through either or both of the pipes 28 and 29, under any suitable pressure, for example of the order of 15 pounds per square inch gauge. The flow of gas through the pipe 28 is nicely con-. trolled by the valve 30, and the fuel delivered through the pipe 29 is controllable by the valve 31. At the forward end of the nozzle structure 25 is a circumferential series of small nozzles 32 delivering jets of fuel merging into an annular jet serving also as amotive fluid jet for entraining and forcing air from chamber 4 into the nozzle structure 11. The forward outer portion of the nozzle structure 25 is tapered inwardly and forwardly as indicated at 33 to form with the adjacent wall structure and/ or nozzle structure 11 an outer annular air passage 34 through which air is induced by jet action into nozzle member 11.

With either or both of the fuel jet systems in operation, air is entrained from the chamber 4 and induced or forced in a stream both through the passage 27 and around the messes exterior of the nozzle structure 25 into the nozzle or diffuser structure 11. Fuel from both nozzle structures, for example oil from. one and gas from the other, is intimately and rapidly mixed with the induced air and prompt y burned, whereby the products of combustion projected into the furnace chamber C contain little or substantially nounburned fuel.

When steam under pressure is utilized, as above indicated, it too serves to produce a motive fluid jet for ejection of air from the chamber 4 into intimate mixture with the fuel in the nozzle structure 11, or 11 and 14, this latter nozzle structure of whatever particular arrangement or form being in effect a so-called reverse nozzle or diffuser.

The furnace structure may have a singl chamber C, or there may be a plurality of chambers or zones traversed in succession by the products of combustion. Heat absorption structure of any type, tubular or otherwise, may be located in any one or more of the zones, and in such relation as to absorb heat delivered thereto either by radiation or convection, or both.

By recourse to an operation of the character described, involving ejector, injector, or aspirator action, the stack draft is not relied upon tocause a flow of air into the combustion system; on the contrary the jet action forces the air into the combustion system, at the same time causing intimate mixture thereof with the fuel for very rapid and substantially complete combustion within a short distance from the point of issue of the fuel from the burner or nozzle structure. Such draft as the stack is capable of producing is utilized, preferably, simply for withdrawing from the furnace the spent gases or products of combustion after they have performed their useful work within one or more furnace chambers.

While not essential, the side and/or mp walls 16 and 17 of the chamber 14 may comprise silicon carbide' or other highly refractory material of high heat conductivity, so that these side and top walls operate as sources of radiant heat to be absorbed by heat absorption structure within the chamber C suitably positioned with respect to these radiating walls.

Vl/hile the passage with n the nozzle member 11 will ordinarily be circular in cross section, it shall be understood that any other suitable c oss sect on as elliptical, oval, or polygona. nay be utilized; and that in genera] the nozzle structure 25 will be of at least generally sim lar configuration.

In Figs. 4 and 5 a structure, generally similar to that above described, is utilized, preferably in multiple unit array.

In the arrangement of Figs. 4 and 5 the combustion-supporting air is delivered into the chamber 4 through the ducts 35 and 36,

the former of cast iron pipe, for example, and the latter formed within the brick or masonry work and covered by sheet iron or cast iron plates 87 which are in turn covered with sheet asbestos 38 and fire brick 39. The [9 plates 37 may have the downwardly and inwardly extending integral heat conducting ribs 37a. T he neighboring and parallel ducts may be cross connected by one or more headers 40.

The air entering at the right of ducts 35, Fig. 4, from the outer atmosphere, is preheated within these ducts before reaching the chamber 4 from which the preheated air is then ejected by the jet operation of the burner structures into the nozzle type combustion chamber generally of the characterhereinbefore described. The air in the ducts 35 is first heated by the hot gases passing over the bridge wall 41 between it and the furnace wall 42 on their way to the outlet 43 which connects to the stack. The remainder of the ducts 35 is heated from the hot gases within the chamber C as is the case also with the air as it further progresses through the ducts 36.

The movement of air through the preheating ducts 35 and 36 is caused or induced by the ejector apparatus, drawing it into the suction chamber 4 and then forcing it into the nozzle type combustion chamber.

In this particular example the heat absorption structure is a shell or drum 44 which may be a steam generator, petroleum still, or the like.

Fig. 6 shows three nozzle type combustion chambers related to the furnace chamber C, it being understood however that any suitable number may be employed depending upon the size or capacity of the furnace or heating system which they serve. It will further be understood that the combustion units of the character described may be argaitilged in horizontal or vertical array, or

While in the foregoing description the fuel, or fuel and steam has or have constituted the motive fluid jet or jets, and the comhustion-supporting air has been the fluid operated upon by such jet or jets, the reverse 115 act on or arrangement is contemplated within our invention. That is to say the combustion-supporting medium, as air, may be utilized for producing the motive fluid jets, and the fuel, solely or in m xture with other 120 material, as steam, may be the fluid operated upon and injected or ejected by the jets.

What we claim is: y

l. The method of burning fluid fuel, which comprises delivering the fuel under pressure 128 to produce an annular jet, delivering fuel under pressure to produce a jet within said annular jet, cntraining combustion-supporting fluid by said jets and forcing it in streams within and without said annular jet and 1% around said second jet into and through a nozzle passage, and therein effecting intimate mixture of the fluids at high temperature and rapid combustion of the fuel.

2. Fuel burning structure comprising a nozzle member, an annular manifold, means for delivering fuel into said manifold, said manifold having outlet structure producing an annular jet of fuel discharging into said nozzle member, said nozzle member having a convergent inlet and said manifold having periphery converging in the same direction with said convergent inlet of said nozzle member, said fuel jet being so related to the inlet of said nozzle member that air is en trained and forced into said nozzle member through the annular jet and between the convergent Walls of said manifold and nozzle inlet passage 3. Fuel burning structure comprising a nozzle member, an annular manifold, means for delivering fuel into said manifold, said manifold having outlet structure producing an annular jet of fuel discharging into said nozzle member, means delivering into said nozzle member a fuel jet Within said annular jet, said jets so disposed with respect to the inlet of said nozzle member that air is entrained and forced into said nozzle member Within and Without said annular jet and around said second named jet,

l. Fuel burning structure com rising a nozzle member, an annular manifo d, means for delivering fuel into said manifold, said manifold having outlet structure producing an annular jet of fuel discharging into said nozzle member, said nozzle member having a convergent inlet and said manifold having a periphery converging in the same direotion'vvith said convergent inlet of said nozzle member, means for delivering a fuel jet Within said annular jet, said jets being so disposed With respect to the inlet of said nozzle member that air is entrained and forced into said nozzle member between said jets and through the passage formed by the convergent Walls of said manifold and the inlet passage of said nozzle member,

5, Fuel burning structure com rising a combustion chamber in the form of a nozzle passage convergent at its inlet, means for delivering fuel in the form of an annular jet discharging into said convergent inlet, and means for producing a jet of atomized liquid fuel Within said annular jet, said jets so related to said convergent inlet that air is en-= trained and forced into said nozzle passage to eiifect therein intimate mixture of the air and fuel and rapid combustionof the fuel.

ARTHUR E. NASH. JAMES S. lhLCQlltN.

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