US1860366A - Furnace and method of operating the same - Google Patents

Description

May 31, 1932. c. E. .LUCKE 1,860,366

FURNACE AND METHOD 'OF OPERATING THE SAME Filed March 11, 1927' .4 Sheets-Sheet i I V 1h )0 Ii /3 W IZ3 V ENTOR I C/MRL ELUC/(E.

fM ATTORNEYS May 31, 1932.

C. E. LUCKE FURNACE AND METHOD OF OPERATING THE SAME 4 Sheets-Sheet 2 Filed March 11. 1827 m P E INVENTOR CHARLES E. Ave/(E. X m/Y /M ATTORNEYS I May 31, 1932- c. El. LUCKE v I FUR NACE AND METHOD OF OPERATING THE SAME 4 Sheets-Sheet 5 Filed March 11, 1927 &

' INVENTORY C/IflPLES E. Lam E. ijw/ M ATTORNEYS May 31, 1932. cv E. LUCKE FURNACE AND METHOD OF OPERATING THE SAME Filed March 11. 1927 4 Sheets-Sheet 4 INVENTOR 5 CHARLES E. ZUCKE %%AM/fjm4@ ATTORNEY$- Patented May 31, 1932 jonaams n mam-gas New YoBx, if; 2.,

FULLER Lauren con irm, n, ooaronarronor nnnawaan I strainer: 21m) mEriuoD '01 orgasms j I Application filed llama 11, m1. serial n. 174,501;

My present invention "relates to furnaces and comprehends methods, applicable to various types of furnaces for burning )VRI'IOLIS fuels, whereby 'combustion is improved by.

the'use of jets of-steam or air or waste flue gases. entering the combustion chamber to .mix the furnace gases for amore thorough or complete combustion of the fuel and.f0r better utilization of air supplied for combuswith'the accompanying-drawings which show various practical applications of'myinventio1i;"-v 1 A high rate of combustion in furnaces is a .matter of importance tofinsure the highest possible-temperatureand a maximum heat output for-a furnace-of agiven size. .Tothis end,'-'the excess air necessary to. insure com ith the meansnow in use it is difficult: to avoid "highexcess airand ;yet have such in tima'cyof contact of fuel and air as will insure short flames and high combustion rates per'cubic foot of furnace volume with reasonablycomplete combustion of fuel. Heretofore there has been also a lack of uniformity in combustion conditions indifi'erent parts of air or steam or partially cooled furnace gases to mix the furnace gases and to protect the furnace lining. Further-objects and advantages will appear later. I

section through a water tube boiler'and-stoker fired furnace; Fig. 2shows a modification of the arrangement of Fig. 1 permitting the use of hotter mixing gases; Figs. 3 and 4 show modifications of the method of employing my show a structure usin tion. My invention will be best understood, from the following description in connection "mg a drum and banks ofhorizontally im .clined tubes 1 11 and 12 connected to -u take headers 13. and 14:: andto downta e lete combustion must be as small as possible.

. boiler tubes 11 an temperatures. Still another obj ect of my invention is the provision of means to utilize jets In the drawings, Fig. 1 is an elevationalinvention i'n'the furnace r of Fig.- 1; Fig. It I Assron'oa, aY. mamas, ro-

showsa. detail from Fig. 4;F1%s.d 6 and 7 this met nection withfurnaces. urning finely divided fuel issuing from. nozzles; and F1g.-8-is a plan in section showing the path of the gases incon from the mixing jets of Figs l, 6 and 7-and taken on the line 8-8 of Fig.- 1.

Like referencev characters indicate like parts in the several views I I show in Fig. 1 a water tube boiler hav-- headers Hand 18 are similarly 'connectedto'" one'another andthei boiler drum 10 b ples 19. and 20', respectively. Asuperlieater has'tubes-22 connecting the headers 23 and ni r p 70 24 and located between-the banks of tubes-' 11 and 12; The headers 23' and 24 form- 'part of an inclinedbaflle. wall. 25 which di 5 12 from adownward pass I over. the tubes "12. The superheater is con- 26 and -may be-connected to the steam. mam by consorestin upon the vides anupward (pass of flue gases overthe nected' to the boiler drum by a pipe nections, not shown.

A. bafile or partition 28 upper tubes of the lower bank of oiler tubes 11 oins the lowerextremity of the bafile 25 1 forming a chamber 29. -The waste or cooled gas for the mixing jets may be taken from the chamber 29 and returned to the combustion" chamber in the manner shown in Fig. 2. A

bafiie wall 30 extends downwardly from the boiler drum 10 to the boiler tubes 12. A baf 90 fie 31 hangs downwardly from the wall 30 and traverses the majority of the boiler-tubes 12 to divide a downward pass of gases from the final upward pass of the same into the fiue32. a g 1 Front and rear walls 33 and 34 and side walls 35 enclosea furnace chamber 36. A stoker 37- of any type feeds solid fuel from' V the front .ofthe furnace and discharges the a 7 way from a steel or other rigid framework.

The flue 32 of Fig. 1 is joined at any desired point by a pipe 40 to tap off and lead flue gases from the flue 32 to the center of, a centrifugal fan 41. The fan 41'delivers the flue gas under pressure tornozzles -42;and 42' through suitable connecting pipes 43. andz44, thus causing the j ets from the nozzles to enter the furnace at high velocity, and one which will cause the jets to pass completely across the furnace chamberandbe deflected fromthe opposite walls. The nozzles 42 and 42 enter the furnace chamber through its rear w'all 34 and discharge jets of gas near opposite side walls of the furnace chamber, at high velocity and at diflerent elevations to cause the fur-- nace gases to whirl oppositely atdiflerent levels; The jets carry the excess air normally present over the ash zone above'the rear of the grate or stocker 37 and forward to the.

part where normally carbon monoxide is rising over the feed end of the stoker. This mixing action will destroy thetendency for the front and rear ing and will there ore. improve'combustion conditions- In Fig. 2 the from the chamber 29 through and between nipples 46 extending between downtake headers 47 and 48.- A pipe 49 returns these hot gases to thev furnace through a steam dI8.-f l7-' I1OZZ18 50. Any number of the draft nozzles 50 may be used-and be located at convenient positions in the wall of the furnace chamber, to get any desired mixing effect.

In Figs. 3 and 4 mixing of the gases takes place as in Fig. 1, but with a slightly-different disposition. of. the nozzles and entering jetsag'aInFig; 3 one or more nozzles 52 are arranged to direct anupwardblast of flue gas approximately parallel with. the rear .wall.

within the furnace with less excess air. The

whirling action'inthe furnaces of FigsJB and 4 may take place in approximately vertical planes.

In F'g. 4 a pair-of parallel bafll'es 53 and 54 follow the lineof spaced boiler tubes 11 and form with an upwardly extending baflie 55 a blast chamber 56 placed above and at the rear ofthe furnacechamber. This chamber 56 is connectedwith a blower by a pipe 57 delivering the gasesii-ntonit, as afeeding cham-.

ber forzmixingino zzles'z ,Jets issuing from the orifices or nozzlesz59 in1the'bafiie-53 move the gases acrossithefurnace and downwardly ases to; rise without mix-r turbulent zone. hot'mixing gases are drawn to establish turbulence and mix the furnace gases. Jets from nozzles 60 in the battle '55 direct streams of hot gas forwardly in an approximately horizontal direction and for the same purpose. The nozzles 59 and 60 are furnished with tips 61 togive 'a :good jet or blast. .The tips 61 "of the nozzles '59 and 60 alsoprevent erosion of the refractory material of the baflie and are of a material suitable for the particular conditions {under which they operate."

In the case of fu nacesheated by finel agivided fuel issuingfrom nozzles, there is 'normally an excess of fuel along the center of the fuel stream and an excess of air forming an envelope surrounding the stream. "It is necessary to mix the center and the envelope to get high rates of combustion and complete combustion with least excess air'. complished by using gaseous jets entering This is acthe furnace at a velocity high enough to keep the furnace gases in a state of turbulence. so that the stream will be whirled about and the center part be mixed with the surroundinglayers, as the stream. enters and-crosses" the The velocity of the entering jets should be sufficient to insurethe required turbulence-and for this reason, it is preferable that the velocity should be sufficient to cause; i

the jets tocross the furnace chamber and strike the opposite walls.

v In' Fig. 6 the fuel nozzles=63 fonburning finely divided fuel are placedin the front wall 64 of the furnace and-the-nozzles 65 and 1 65 introduce flue gas through the rearwall 66 of the furnace in a manner similar to that of Fig. 1. The staggered arrangement ofthe nozzles and the resulting'method of mixing of the gases may be the same as inFig. 1 and as shown in plan in Fig. 8, or they may bev different in the object of maintaining a suit.-

t-ableturbulence in thefurnace. a

- Fig. 7 shows a furnacefor the burning of finely divided fuel. A nozzle 68 mounted above the furnace chamber directs a downwardly extending flame or fuel into the chamber. Nozzles 65 and 65 piercing the rear wall 69 discharge streams of gas into the furnace ,and'against the front wall 70. These streams of gas have sufiicientvelocity to mix the stream of burning fuel with the air surrounding it within the furnace by keeping the furnace in a turbulent state as the-fuel stream crosses the turbulent zone.

It will be obvious that the application of my method is not limited to the exact structure shown and that other mixing fluids, such conditions in the furnace chamber. By these means, the rate of combustion is raised with use of least excess air. The maximum heat generation is assured before the gases reach as airwor steam, may be used, and other jet arrangements may be used to improve mixing the boiler tubes and the maximum boiler capacity ismade available. without losses of ma am v 3 efliciency such as results when gases burn between tu The invention is particularly useful in connection with the type of apparatus in which the furnace is relatively large with respect to the area of the boiler pass through which gases from the furnace travel as they contact with the water tubes of the boiler. In that m type, the gases in the furnace are very apt to form laminations which prevent thorough mixing of the gases, and consequently, complete combustion is prevented, even with a possible excess of air. My invention overcomes this difiiculty by causing complete mixing of the gases in the furnace before they reach the pass through which they travel across the water tubes.

I claim: 7 1. In combination, a furnace having a burner therein, means for mechanically supplying fuel to said burner, a bank of boiler tubes disposed over the furnace, a roof bafile adjacent the bottom of said bank, a cross bafile extending upwardly from the room baffie to form a gas pass across the tubes, nozzles in said roof battle, and means to discharge waste gases that have passed over said tubes through said nozzles, the space in the furnace beneath the tubes being relatively large with respect to the gas pass across the tubes. 2. In combination, a furnace having a burner therein, means for mechanically suppl ing fuel to said burner, a bank of boiler tubes disposed over the furnace, a roof baffie adjacent the bottom of said bank, a cross baflle extending upwardly from the roof baffie to form a gas pass across the tubes, nozzles in said roof bafile and in said cross bafile, 40 and means to discharge waste gases that have passed over said tubes through said nozzles, the space in the furnace beneath the tubes being relatively large with respect to the gas pass across the tubes. 3. In combination, a furnace having a burner therein,'means for mechanically supplying fuel to said burner, heat-absorbing surfaces over which pass the hot gases from said burner, means forming a restricted pas- 50 sage over said surfaces for said gases, said furnace having a space between the burner and the surfaces which is relatively large compared to said passage, a fiue for conducting said gases away from said surfaces, and

55 means for returning part of said gases to said space and for discharging them thereinto at a high velocity to thereby agitate. the gases passing from the burner to the heat-absorbing surfaces.

, CHARLES E. LUCKE.

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