US3473793A

US3473793A - Hot blast stove

Info

Publication number: US3473793A
Application number: US638702A
Authority: US
Inventors: Wolfgang Cronert
Original assignee: Martin and Pagenstecher AG
Current assignee: Martin and Pagenstecher AG
Priority date: 1966-05-13
Filing date: 1967-05-10
Publication date: 1969-10-21
Anticipated expiration: 1986-10-21
Also published as: NL6706517A; BE698320A; DE1526029B1; AT274196B; LU53661A1

Description

Oct. 21, 1969 w. CRONERT 3,473,793

HOT BLAST STOVE Filed May 10, 1967 4 Sheets-Sheet 1 lave/liar: Wolfgang Cromert Fitter w ys Oct 21, 1969 w. CRONERT 3,473,793

HOT BLAST STOVE Filed May 10. 1967 4 Sheets-Sheet 2 Fig. 2

In venlor Wolfgang Cronert Get. 21, 1969 w. CRONERT 3,473,793

HOT BLAST STOVE Filed May 10. 1967 4 Sheets-Sheet 5 Fig.3

6 514 I I J lnvenlor: Wolfgang Cronert Hthorneys Oct. 21, 1969 w. CRONERT 3,473,793

HOT BLAST STOVE Filed May 10. 1967 4 Sheets-Sheet 4 Fl'g5 In ventur:

Httorneys 3,473,793 HOT BLAST STOVE Wolfgang Cronert, Eikamp, Germany, assignor to Martin & Pagenstecher Aktiengesellschaft, Cologne-Mullieim, Germany, and Rheinstahl Export Industriealagen GmbH, Essen, Germany, both corporations of Germany Filed May 10, 1967, Ser. No. 638,702 Claims priority, application Germany, May 13, 1966, s 103,773 Int. Cl. C21b 9/02 US. Cl. 263-19 7 Claims ABSTRACT OF THE DISCLOSURE This specification describes an improvement in hot blast stoves having no separate combustion chamber. Such furnace has a heat retaining latticework, a truncated conical member thereabove and a cupola atop this cone. The cupola has a generally hemispherical central member. The conical member is joined at the top thereof to a cylindrical section of lesser diameter than the cupola cylindrical section. The two cylindrical sections ar concentric over at least a portion of their length and have disposed therebetween an annular air channel and an annular fuel gas channel which are operatively associated with an annular mixing channel communicating with upwardly directed nozzles.

The invention relates to a combustion chamber-less hot blast stove having a burner disposed in the upper, lattucework-free portion of the furnace, whose exhaust gases are carried downward through the stove and flow through and heat the heat-storing latticework.

Burner arrangements of this kind have been disclosed, for example, in German Patents 318,068, 863,663, and 961,284, wherein combustion gas nozzles and combustion air nozzles are disposed in the cupola of the furnace.

Unless a relatively large number of nozzles are installed at great expense, the disadvantage occurs that irrigularities occur in the exhaust gas flow, which are produced by the position and aim of th nozzles, so that the heat storing latticework is overheated at some points and at others is insufiiciently utilized.

Various proposals have been made for improving the conditions of exhaust gas flow. According to German Patent 957,848, the combustion mixture is blown in through burners which discharge tangentially into a horizontal annular channel between the latticework and cupola, the said channel being open at the top, According to German Patent 483,824, separate gas and air nozzles which are directed upward are disposed between the latticework chamber and an overlapping stove cupola. In this manner, the flow of the gases is so conducted that the flames describe U-shaped paths and therefore have more time to burn themselves out; the mixing of gas and air, which in this arrangement first takes place in the latticework-free portion of the stove, is nevertheless very poor, so that complete combustion cannot be achieved.

It is therefore an object of this invention to provide a novel hot blast stove combustion system.

It is another object of this invention to provide a hot blast stove combustion system in which extremely uniform flow of combustion and exhaust gas in achieved.

It is a further object of this invention to provide such a hot blast stove wherein particularly intimate fuel and air mixing is accomplished, whereby substantially complete combustion is achieved.

Other and additional objects of this invention will become apparent from a consideration of this entire specification including the drawing and claims hereof.

In accord with and fulfilling these objects, one aspect of this invention resides in a combustion chamber-less hot nited States Patent Car blast stove, wherein the burner has annular channels disposed within the outer periphery of the furnace, at least one of which has at least one fuel gas inlet and at least one of which has at least one air inlet, and wherein the channels are provided with a plurality of orifices for discharging the combustion substances into the furnace.

Preferably, the hot blast stove has a section above the latticework which tapers inwardly towards the top where it joins a cylindrical section which is overlapped by the cupola and the annular channels are disposed between the cylindrical section and the overlapping cupola.

This arrangement not only permits an especially simple way of connecting the channels to the fuel gas and air lines, but also keeps the cost of the burner and its weight low, sinc the burner ha a smaller diameter than the portion of the furnace that is equipped with the heat-storing latticework.

It is advantageous if the channel orifices, from which the combustion substances emerge, are upwardly directed and if the furnace cupola consists of a generally hemispherical upper portion surrounding a generally downwardly directed cylindrical portion. The combustion gases are reflected downward by the hemispherical top portion and are thus additionally intermixed.

According to a preferred embodiment of the invention, the hot blast stove is encircled by an annular fuel gas manifold and an annular air manifold from which a plurality of pipes carry the gas and air respectively to the above-recited annular channels.

According to another preferred embodiment of the invention, one pipe carrying fuel gas and one carrying air open tangentially into the annular channels.

A blast discharge pipe is preferably connected to the cylindrical portion of the cupola or to the cylindrical section of the furnace directly beneath the burner.

Understanding of this invention will be facilitated by reference to the accompanying drawing, in which:

FIG. 1 shows a longitudinal section through the upper portion of a hot blast stove according to the invention (exemplary embodiment 1);

FIG. 2 shows a cross-section through the hot blast stove of FIG. 1, in which sector a corresponds to line HaIIa of FIG. 1, sector 11 to line IIb-Ilb of FIG. 1, and sector 0 to line IIc-IIc of FIG. 1, and in which the right half corresponds to line II-II of FIG. 1;

FIG. 3 is a longitudinal section through the upper portion of another hot blast stove according to the invention (exemplary embodiment 2); and

FIG. 4 is a cross-sectional through the hot blast stove of FIG. 3, the left half corresponding to line IVaIVa of FIG. 3, and the right half, which is rotated within the plane of the paper, corresponding to line IVb Nb of FIG. 3. FIG. 5 shows a longitudinal section through the upper portion of a further hot blast stove according to the invention (exemplary embodiment 3).

In each of the embodiments shown in FIGS. 1 and 3, a hot blast stove is depicted as containing a heat-storing latticework 2, joined by an inwardly directed upwardly tapering intermediate section 3 to a cylindrical section 4, which cylindrical section is overlapped by a cupola 6. A burner 5 having two

annular channels

7 and 8 is disposed between the cylindrical section 4 and the overlapping cupola 6. Annular channel 7 is equipped with fuel gas feed pipes 9 (only one in embodiment 2 of FIG. 3),

and annular channel 8 is equipped with combustion air feed pipes 10 (only one in embodiment 2). The annular channel 7 has upwardly directed orifices 11, and annular channel 8 likewise has upwardly directed orifices 12. Above

orifices

11 and 12, there is located an annular chamber 13 topped by a diffuser 14 which contains a series of slits 15.

The brickwork consists of the refractory materials customarily used. a

In embodiment 1 (FIGS. 1 and 2), the hot blast stove is encircled at the level of the

annular channels

7 and 8 by an annular fuel gas manifold 17 and an annular air manifold 18 respectively, from which fuel gas pipes 9 and air pipes 10 lead to the

annular channels

7 and 8.

Each

feed pipe

9 and 10 has a throttle valve and a slide valve by means of which gas and air can be uniformly distributed over the annular cross-section of the burner 5.

The cupola 6 consists of a hemispherical upper portion surmounting a cylindrical portion to which a blast dis charge pipe 16 is connected.

In the embodiment 2 of the invention (FIGS. 3 and 4), a fuel gas feed pipe 9 and an air feed pipe 10 lead tangentially into the

annular chanels

7 and 8, respectively. Just as in embodiment 1, the cupola 6 has a hemispherical upper portion surmounting a cylindrical portion; the latter, however, is very short. On the other hand, in this furnace, the cylindrical section 4 between the upwardly tapering portion 3 and the cupola 6 is longer than in embodiment 1, and the hot blast discharge pipe 16 is connected to it.

In embodiment 3 of the invention (FIG. 5) no inwardly directed upwardly tapering intermediate section is provided, cupola 6 and the burner being mounted directly on the wall of the latticework section, which wall extends a little beyond the upper end of the latticework 2. Except for this, all parts of this hot blast stove are the same like in embodiment 1 and are acting in the same manner.

During the heating period, gas and air flow into

channels

7 and 8, distribute themselves therein, pass through

orifices

11 and 12 into the annular chamber 13, and are mixed together in the latter. The mixture emerges from annular chamber 13 through the slits 15 in diffuser 14 and burns. Dividing the gas and air flow into many small individual currents makes possible an especially good intermixture of the two. The gases are deflected downward by the spherical shape of the cupola 6. On their further course through the cylindrical section 4 and the tapering portion 3, they have sufiicient time to burn out completely before they enter into the latticework. The hot exhaust gases then flow through the heat storing latticework, yield most of their caloric content to the latter, and emerge from the stove at the bottom end thereof. An especially uniform distribution of the hot exhaust gases through the latticework is achieved by this arrangement according to the invention. During the blast period, in which no heating takes place, cold air is blown in at the bottom end of the hot blast stove, is heated by the heat-storing latticework, and emerges from the stove 1 through the hot blast discharge pipe 16.

The upwardly and inwardly tapering intermediate portion 3 is mounted on the portion of the furnace 1 that contains the latticework z, and burner 5 is mounted on the cylindrical section 4, in such a manner that the walls of the adjoining parts of the stove can shift in relation to one another when they expand by different amounts due to heat.

What is claimed is:

1. In a hot blast stove containing a heat-retaining latticework section in the under portion thereof and a cupola as the top member thereof; the improvement which comprisesproviding a burner between said cupola and said latticework section wherein said burner comprises two annular channels adapted respectively for the receipt therein of fuel gas and air, an annular mixing chamber adapted to receive the efi lux from said annular channels and a multiplicity of orifices communicating between said channels and a combustion area.

2. An improved hot blast stove as claimed in claim 1 wherein said orifices are upwardly directed. i

3. An improved hot blast stove as claimedin claim 11 wherein an upwardly and inwardly tapering generally truncated conical member atop said latticework section is provided, wherein said cupola has a generally hemi spherical central portion attached to a generally cylindrical portion, wherein said conical portion has a cylindrical member of lesser diameter than said cupola cylinder atop thereof, and wherein said burner is disposed between said cylinders.

4. An improved hot blast stove as claimed in claim 1 wherein said channels are operatively associated with a multiplicity of feed pipes thereinto, and with an annular chamber adapted to receive the efilux of said channels, and wherein said chamber has a diffuser operatively associated with the exit end thereof.

5. An improved blast stove as claimed in claim I wherein one feed pipe leads tangentially into one of said channels, and one feed pipe leads tangentially into the other of said channels.

6. An improved blast furnace as claimed in claim 1 having a hot blast discharge duct in operative association with said cupola.

7. An improved hot blast stove as claimed in claim 5 having a hot blast discharge duct in operative association with said cylindrical member atop of said conical portion.

References Cited UNITED STATES PATENTS 8/1889 Williams 266-l4 FOREIGN PATENTS 43 8,824 10/ 1929 Germany. 1,087,076 8/1954 France.

U.S. Cl. X.R. 266-29 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,473 ,793 October 21 19' Wolfgang Cronert It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 50, "438,824" should read 483,824

Signed and sealed this 27th day of October 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, J r. Attesting Officer