US1217039A - Preheating of air for hot-blast stoves of blast-furnaces. - Google Patents

Description

. E. E. MARSHALL.

PREHEATING OF AIR FOR HOT BLAST STOVES 0F BLAST FURNACES.

v APPLICATION FILED APR.4,1916. 1,217,039.

Patented Feb. 20, 1917.

4 SHEET$-SHEET I.

E. E. MARSHALL.

PREHEATING OF AIR FOR HOT BLAST STOVES 0F BLAST FURNACES.

APPLICATION FILED APR. 4, 19H)- Patented Feb. 20,1917.

4 SHEETS-SHEET 2.

E. E. MARSHALL. PREHEATING OF AIR FOR HOT BLAST STOVES 0F BLAST FURNACES.

APPLICATION FILED APR.4, 1916. 11,217,039. Patented Feb. 20,1917.

4 SHEETS-SHEET 3.

E. E. MARSHALL. PREHEATING OF AIR FOR HOT BLA ST STOVES 0F BLAST FURNACES.

APPLICATION FILED APR. 4, 1916. 1,217,039. Patented Feb. 20,1917,

\ 4 SHEETS-SHEET 4.

ram sro w: are vs 670 v4: Jrovs To all whom it may concern:

Beit known that I, EDVFARD E. MARSHALL, a citizen of the United States, residing in enrich.

nnwann E. mansmm,;or PHILADELPHIA, rnnnsrtvaaim.

i PREEATING- OF'AIB FOR HGT-BLAST S TOVES 0F BLAST-iU-ENACES,

Philadelphia, Pennsylvania, have invented certain Improvements in the Preheating of Air for Hot-Blast Stoves of Blast-Furnaces, of which the following is a specification.

My invention rela to the pre-heating of air for blast furnace use, and consists more particularly of improved means for supplying the hot blast stoves of blast furwith pre-heated air, which air after further heating in such hot blast stoves is delivered to the blast furnace in a highly heated state. F or the best results, this air' must be at a relatively high and substantially uniform temperature, and, the usual practice heretofore has been to utilize the structures familiarly known as hot blast stoves, which stoves contain certain forms of heating devices whereby cold or relatively E cold air introduced into the same can be highly heated, and heated to the temperature desired before being introduced into the blad furnace.

Various forms of hot blast stoves are em.

ployed in practice but, asmay be readily understood, the introduction of relatively cold air or air at atmospherictemperature is highly destructive of the heating portions of such hot blast stoves; hence the necesity of comantly repairingportions destroyed by stir-was or breaks occasioned by the t difierence between the temperatures 0 the incoming and outgoing air. Moreover the use of hot blast stoves for supplying all of the heat necesary for the required amount of air passing therethrough to the blast fun naee necessitates the employment of a large number of stoves to maintain the desired or required supply of heated air, which stoves, however, are unable'to impart the really high heat desired to air entering at ordinary atmospheric temperature. When, however, as in my method of promure. the arsentering the hot blw stove has been raised approximately to 600? F'the- Work of the hot blast stove is materially lessened, withv a consequent reduction of ener necessary to raise it to the high heat deslred, and. by reason of supplying the blast furnace with the required amount of highly hwtwalr,

. the amount of fuel required therein for smelting purposes is materially le sened.

The object of my invention is to provide Specification of Letters Patent.

-' whereby air at atmospheric temperature may be heated to a relatively high temperature before introduction into. thelhot blast stove, wherein the temperature of such air.

Patented rep. 2e, tea a. Application filed April a,- 1916. Serial no; cases.

the inlet and outlet of the hot blast stove shall be materiallylessened. A further ob j ject of my invention is to economize the amount of fuel required-in the blast furnace for smelting purposes, and further to greatly reduce the time usually required to heat the air employed in the blast furnace in the hot blast stoves. While heating means for the pre-heater may beobtained from any suitable sourcefI preferably. employ the waste gases direct from the blast furnace which are delivered to suitable burner structures at the inlet end of the pre-heater.

These and other features of m invention are more fully described hereinafter, reference being had to the accompanying drawings, in which: a

Figure 1, isa sectional plan view of a pre-. heater structure embodying my invention;

Fig. :2. is a longitudinal section of the same on the line HH, Fig. 1;

Fig. 3, is a'front elevation of the preheater structure;

Fig. 4, is a vcross sectionaltview on the line IVIV, Fig. 1;

Fig. 5. is an enlarged view of a. portion of the tubular air-passages in the pre-heater in which the air is heated, and

Fi 6, is a diagrammatic view illustrating die layout of blast furnace, hot blast stoves and pro-heater;

My improved pre-heater structure ma eomprise a substantially rectangular buil ing 1 of suitable type, preferably of the usual furnace construction, with fire-brick lining &c., and the pre-heater proper preferably'embodieis a pair of units 1* and 1*, which may be worked alternately or simultaneously as may be necessary or desirable. for the requirements of the hot blast stove or stoves, or the blast furnace.

Within the chambers I and 1 of the pro-heater structure, I provide aplurahty of conductors 2 for the heated air, wh ch conductors are substantially of inverted U- shape-1n cross section, projecting vertitally into the chambers and having their.

free ends wnnectm to manifolds? so as to I make continuous channels ofa tortuous type providing for the heating of a'larw quanm of air. temperature is delivered to Air at 'or about atmospheric these conductors 2 through pipes a from a manifold 5 which in turn receives such air from a blast pipe 6 leading from a suitable-blowing engine ,7, and from said conductors the heated air is led by suitable conduits 8 to a manifold 9 from which it passes to a pipe 10,: thence to lamanifold receiver 11, and from thelatter it passes to the inlet ports 12 of the hot blast stove or stoves 13. The latter may receive heated air from the conductors 2 of both chambers 1 and 1", or from either chamber alternately.

The inlet end of the pre-heater isprovided with suitable burners 16 arranged to receive, via a conduit 17 the gas dischar ed direct from the blast furnace, which pro erably passes through a dust catcher 15 before entering said burners 16, where it is burned for the purpose of heating the air to be subsequently delivered to the blast fur nace; the'flame from such burners being delivered to or discharged into the chambers l and 1 of the pro-heater structure around I the conductors 2.

The quantity of the air to be heated which is introduced, into the manifolds 30f the conductors 2 from the pipes 4, is controlled by valves 19, and the conduits 8 are provided with valves 20 whereby delivery "of the heated air to the several pipes for passage to the hot blast stove or stoves may be controlled or regulated.

By my improved arrangement and con I struction of pre-heating means, I am enabled to use the waste gases direct from the,

blastfurnace to raise the temperature of the air no such pro-heater structure, which preheated air is delivered .to the checker brick hot blast stoves. In this way air at a very high temperature is delivered to the hot blast stoves wherein it is heated to a much higher and desired temperature with the consequent result that as the incoming air is hot, it'does'not have to be raised from a low temperature to a high temperature in the hot blast stoves but being at a relatively high temperature upon entrance into the hot blast stoves it may be quickly raised therein to the desired temperature before passing to the blast furnace. This extra heating can be effected in a much shorter time than the entire heating usually performed by the hot blast stoves, and as the "high temperature highly heated. As suchnecting the hot mimosa tionable cooling by theneception of" air at atmospherictemperature, their life isgreatly prolonged and their value as heating means is greatly increased.

Furthermore, T am enabled by. my particular arrangement to impart a higher and more uniform degree of heat for a longer period, with'the additional advantage of thereby reducing the consumption of fuel in' the blast furnace. The greater the temperature of the air delivered to the blast furnace, coupled with uniformity of such in the continuing volume delivered, the less fuel will be required to overcome the variation in temperature necessary to raise the heat in such furnace to the smelting point. A further feature of economy is that the pre-heating of the air according to my arrangement enables me to cut down the capacity or number of the hot blast stoves, and inasmuch as the number of stoves (or hot blast stove capacity) can be reduced, the cost of plant equipment is proportionately reduced.

ll claim:

1. The combination with a blast furnace and hot blast stoves employed therewith, of a pre-heating device for air, means for delivering heated air from said pre-heating device to said hot blast stoves, a connection between the furnace and the pre-heater for the passage of waste gas direct to said preheating device, burners for the latter discharging into said preheater, a conduit connecting-the hot blast stoves with the blast furnace, and valves controlling the passage of air to and from said hot blast stoves.

2. The combination with. a blast furnace and hot blast stoves employed therewith, of

device to sald hot blast stoves, a connection between the furnace and the ore-heater for k the passage of waste gas direct to said preheating device, burners for the latter discharging into said pro-heater, a conduit conblast stoves with the blast furnace, and valves controlling the passage of air to and from said hot blast stoves.

3. The combination with a blast furnace andhot blast stoves employed therewith, of an air pro-heater, furnace and the pre-heater for the passage a connection between the of waste gas direct to said pre-heater, con- 7 nections between the furnace and the hot blast stoves for delivering waste gas thereto independently of such delivery tothe preheater, burners-mounted in the pre-heater for the combustion of the waste gas de-' livered thereto from the blast furnace; said burners discharging their flame into the chambers of the pre-heater, means for delivering heated air from said pre-heater to (50 ter, burners or the combustion of thewaste 'gas dehvered to the ing located between the'hot blast stoves and,

the furnace, a plurality of air conductors ered to the pre-heating device from the blast the hot blast stoves including ipressilrej means, a conduit connecting the hot'blast stores with the blast furnace, and valves nace and hot blast stoves therefor, ofa pre heater in which air is heated by; the waste:

gases direct from the furnace,.- said "preheater being'located between the hot blast stoves andthe furnace, a plurality of air; conductors in saidpre-heater, and valves; controlling the inlet and discharge of air to and from said Dre-heater.

heater in which air is heated by the"was'te gases from the furnace, said 'pre-heaterbev in said pre-he'ater, valves controlling the inlet and discharge of air to and from said pre-heater, and a blower for delivering air to the pre-heater and continuously dischar'ging the air heated therein to the hot blast stoves. a

ends of said tubes, a ,valved conduit for, leading a1r to said tubes, a valved conduit for leading heated air from said tubes, burners for dlscharging flame into said heating chambers, and means for delivering waste gas direct from the blast furnace to said burners.

posed between the latter and a blastfur into-said chamber, manifolds for the lower ends of said tubes, a valved conduit for'lead-f ing air to said tubes, a valved conduit. for

leading heated air from said tubes, a blower waste gas from the blast furnace .to said burners. v a 8. Ina system for heating air forblast furnaces and passing the same thereto via hot blast stoves employed therewith, the combination ofta pres eating-device for air, means for delivering air under pressure to said pre-heating device, a connection between the furnace and the pre-hfe'ating device for the assage of waste gas-to the latpre-heating device from the blast furnace; said burners discharging their flame directly into said pre-heatin device and-the heated air, from said .pre-h the 5. The combinatiomiwith a smelting nace and hot blast stoves therefor, of a pm I "blast stoves for delivering waste gas therea to independently of the delivery of such waste gas to the pre-heating device, burners previouslyintroduced iti'to the pre-heater, 1

means afi'ording communication between the hot blast stoves and thelblast' furnace, and," means for controlling the passage of the heatedair to and from'said hot blast stoves. I I

' 9Q In a systemfor heating air for blast furnaces and passingthe same thereto via hot blast-stoves employed therewith, the

combination ofa preheating device for air,

means-for delivering air under pressure to said Ipixieaheating device, a connection between nace and the pre-heating device for the passage of, waste gas direct to the latter,

connections between the furnace and the hot for the combustion of the waste gas delivfurnacej; said burners, discharging their flame directly into said pre-heating device 1 and the heated air from said pre-heating de vice being delivered to" the hot blast stoves 955 v i r by the same pressure means which previ-r 6. In -a pre-heater for hotblast stoves disously'introduced ittothe pre-heater, means I I blaststovesand the blast furnace, and means for controlling the passage of the heated air into said chamber, manifolds for the lower 1 to and from said hot blast stoves.

affording Jcommunic'ation'between the hot 4 a --'i10. Ihe method of-v heating air for the blast of a smeltingor other furnace, which consists in delivering airunder pressure to a conduit disposed-within a combustion chamber-coincident with the delivery to, said chamber of waste gasidirect from said blast the air in said combustion chamber in sup- 1-.porting the combustion of the waste gas nace, the combmatlon ofa'chamber, a,p1urahty of heatlng' tubes projecting vertically whereby the air in the conduit within said combustion chamber is highly heated, delivering such heated air to a hot blast stove, raising the temperature of such heated air in the hot blast stove, and finally delivering said twice heated'air to the smelting furnace. i

11. The furnaces and passing the same thereto via; hot blast 'stoves employed therewith, which I furnace,-utilizing azpoi'tionof the oxygen of 7. In a pre-heater for hot blast stoves, dis

method of heating air-for blast 7 comprises the deliveryof air under pressure" direct fromthe furnace to said eating element, burning the waste gas delivered to the tion between the hot blast stoves and the to a heating element, deliverin wastegas blast furnace, and controlling the passage of the heated air to and from the hot blast stoves a .12; lhe method of heating ,air for blast furnaces and passing the same thereto via hot blast stoves employed therewith, which comprises the delivery of air under pressure .to a heating element, delivering waste gas gas to the hot blast stoves, burning the waste gas delivered to the heating element whereby, the flame from such combustion 1-) may discharge into the interiorthereof; the

so heated air being delivered to the hot blast stoves by the same pressure which previously introduced it to the heating chamber, pro

viding communication between the hot blast stoves and the blast furnace, and controlling the passage of the heated air f ing .elementto the hot blast sto es and from the latter to the blast furnace; I

EDWARD 'E. MARSHALL.

cm the heatp

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