US1531649A - Furnace - Google Patents

Description

' March 31, 1925.

W. DYRSSEN FURNACE Filed June 28, 1923 4 Sheets-Sheet 1 INVENTOR TWa/demar D r'ssen.

ATT RNEY March 31. 1925.

W. DY RSSEN FURNACE Filed June 28. 1923 4 Sheets-Sheet 2 INVENTOR Vl/aemarfl BY rlim March 31. 1925. 1,531,649

W. DYRSSE N FURNACE Filed June 28, 192.5 4 Sheets-Shet 4 INVENTOR ATTORNEY Patented Mar. 31, 1925.

UNITED STATES WALDEMAR DYRSSECN, OF NEW YORK, N. Y.

FURFTACE.

Application filed June 28, 1823. Serial No. 648,254.

T all whom it may concern:-

Be it known that I, VVALDEMAR DYRSSEN,

i a citizen of theUnited. States, and resident of the city, county, and State of New York,

have invented certain new and useful 1111- provements in Furnaces, of which the following is a specification.

This invention refers to open hearth and other furnaces having regenerators for preheating the combustion air and to the method and means for reversing the direction of flow of air through the regenerators, but with the flame flowing constantly in the same direction through the melting chamher. In an ordinary open hearth furnace the combustion air and sometimes thefuel, as for instance in the case of producer gas, is preheated in regenerators and at the reversal of the flow in the regenerator chainbers the flame is also reversed in the melting chamber, so that at one period the flame enters the melting chamber at the left hand end of the'furnace and the next period 1 at the right hand end.

It has been proposed before, to use unidirectional flame, that is, to have the combustion air and fuel enter the melting chamber from-oneend only at all times. The

flow of air through the regenerators as heretofore arranged 'Was reversed by manipulating valves in the passages between the regenerators and the ends of the furnace. Such valves .are necessarily located where the Waste gases from the furnace and the combustion air are hottest. These valves do not stand up in practice except with the use of extreme water-cooling which, however, cools down the gases and the combustion air to such an extent that the proper flame temperature cannot be maintained in thefurnace. On account of this disadvantage, the uni-directional flame .furnace has not been successfully used and is not used at the present time.

In my invention I haveno valves in the hot flue's between the regenerators and the melting chamber; either in the) waste gas passage orfin" the hot air passage. Instead of val-ves I provide means for creating the necessarygpressure difference by'the use of nozzles, according to theinduced draft method. These nozzles can either function in such a way that the flow of gases is obtained or they can function in such away that the openings in the gas passages are,

filled with the gas introduced through the nozzle, creating a pressure difference in the fines at this point, so thatno gases passthrough the flue. In other words, the induced draft acts as a shut off valve.

I have illustrated embodiments of the invention in the accompanying drawings in which Fig. 1 is a plan view of the furnace and associated parts;

Fig. 2 is avertical section on line 22 of Fig. 1 through the melting chamber and ends of the furnace;

Fig. 3 is a vertical section on line 3-3 of Fig. 1 through one of the regenerators of the same furnace;

Fig. 1 is a plan of a somewhat modified furnace; I Fig. 5 is a section on line 5-5 of Fig. 4.

Referring to Fig. 1 the furnace illustrated has the usual hearth 1, a front wall 2 with door openings 2 anda back wall 3 with the tapping spout 4.. The fuel and air are introduced at the right end 5 of the furnace, and products of combustion are withdrawn at the left end 6. In this furnace, only the air is preheated and therefore only two regenerators 7 and 8 are used. The 3 'upper' parts 9 of the regenerators 7 and 8 communicate through Venturi shaped openings 10 and 11 respectively with a common flue 12, having a port opening 13 at the end 6 of the melting chamber. At points in the wall opposite the openings 10 and '11 are nozzles 14 and 15 through which waste gases are supplied under pressure through pipes 16 and 17 by a fan 18 which-takes the gases directly from the stack 19. The upper part 9 ofeach of the regenerators also communicates through flues 20 and 21 respectively with Venturi-shap'ed openin s 22 a and 23 with; the vertical flue 24 at t: eilgburner end of the furnace. The air inlet flue to the melting chamber is inclined as indicated by 25 (Fig. 2'), at the point where the fuel is introduced through burner 26. The fuel used is either tar, coke oven gas, powdered coal, fuel oil, naturalfgas or producer gas.

At points in the walls opposite'the Venturi openings 22 and 23, nozzles 27 and 28 are mounted. 3 These nozzles are supplied with ease gases under pressure through pipes 29 and '30, from fan 18. The respective lower part 31. of the regenerator cha n ber communicates by fiues32 and '33 re spectively with the stack 19. v Shut-01f valves 32 and '33 are placed in-theee flues,

land-fan 35 supplies combustion air alter- 16, 17, 29 and 30" are provided in thefour pipes 16,- 17 29 and 30 as shown.

In operation for one period the stack valve 32 in 'flue32 is closed and air is supplied from fan 35 through the pip 32. and flue 32. The air enters at the bottom of regenerator 7 and flows upward through the checker bricks whichhave been previously heated and the air is thus heated when it reaches the upper part of the regenerator. From here the ,air flows 1 through -flue 20, to opening 22 and flue 24 where it meets the fuel introduced through the burner 26. -The'flame is introduced in the melting chamber above the hearth 1 and the waste gases are drawn through the port opening 13 into flue '12. From this flue the gases flow through the opening 11,=

into the upperpart of the regenerator 8 and the waste gases descend through the checker work, heating up same, and are finally withdrawn through flue 33 leading to the stack 19, the stack 'valve 33 being open at this time. There is, however, lower pressure in the waste gas flue 12, than in the upper part of regenerator 7 The air in this part would therefore have a tendencyto flow directly into flue 12 if there we're no means of preventing it from doing .so; In order to.prevent this flow, the valve 16 in pipe 16 is opened and waste gases in- 35. troduced through the nozzles '14 at. this point. .These waste gases create such a condition in the 'Venturiport 10 that a pressure difference will exist between the regenerator or right hand side and the 'waste'gas flue side or left hand of this opening. If the quantity and the pressure of the gases introduced at 14 is proper, there will be no flow of air or waste gases through tityof waste gases introducedthrough the nozzle 14 will pass off through flue 12, into regenerator 8, with the waste gases comingfrom the melting chamber;

In a similar ,way there exists a pressure difleren'ce between flues 24 and 21, and waste gases under pressure are introduced at 28, in order to prevent" flow of, air

through opening 23, in the same manner as described in opening 10. There is no need at this time of a flow of waste ases through the nozzles at 27 and 15. T e waste gas ets that are used as a means of shutting off openings 10 and 23, cool down the waste gases to'a certain extent before they enter the checker-work in regenerator 8. How i ever, the cooling down will not be sutficient r to interfere with the proper heating of the checker-work in the regenerators which pre- 7 heat the air to the desired temperature i When the flow of air and waste gas opening 10, and the relatively small quan through the regenerators: is rev sed, the stack valve 32 in flue 32 is. open d and the valve 33* in flue 33 closed and valve 36 is shifted to divert the air from the fan into flue 33. The valves 16 and 30 in pipes 16 and 30 respectively are closedand in the melting chamber thus it is clear,

that the flame and gases flow constantly 'in the same direction through the ,melting chamber.

Referring to the modified arrangement showlr rn Figs. 4 and 5, the outlet 39 from the melting chamber is Venturi-shaped and of oblong form as indicated. There. is an oblong nozzle 40 in the roof above the opening 39 through which waste gases under pressure are introduced. Opening 39 communicates with a flue 41 which communicates with the upper parts of regenerators 42 and 43. The other end of the upper part of each of the regenerators 42 and 43 communicates by a flue 44, with the burner end of the furnace. ed in Fig. 5 is suitable for producer'gas coming directly from the producers. The producer gas comes through pipe 45, provided with a regulating valve 46, and is introduced. into the burner through flue 47. The lower partslof the regenerato'rs communicate with the stack, not shown, by flues 48 and 49, in substantially the same way the flues 32 and 33 are connected as explained with reference to Fig. 1; and the combus tion air is supplied to either flue 48 or 49 in a similar way, as describedwith reference to that figure.

In operation of the arrangement shown in Figs. 4 and 5, the stack valve in flue 48 is closed and combustion air is introduced into this flue. The air is preheated in regenerator 42, and flows to the burner.

through flue 44. The waste gases are withdrawn through the opening 39 and flue41 The burner 50 indicat- I to regenerator 43, and pass alternately to the stack through flue 49. There is, however, a pressure difference between the upper parts of regenerator 42 and flife 41 so that the combustion air would tend to pass directly into flue 41 if this pressure diifen ence was not. eliminated. In the same way air would pass from the upper part of regenerator 42' through flue 44 to regenerator 43 and to the stack, if, the pressure 'diflerg ence was not eliminated. 'The elimination of this pressure difference is accomplished by blowing a jet of waste gas at a fairly high pressure from the nozzle 40 into the Venturi port 39.and the pressure difference is creat-- ed between the melting chamber and flue 41. If the pressureof the waste gases through nozzle 40 is properly regulated, the 1 pressure .in flue 41 and in the upper part of the checker chamber 42 willbe exactly the same and there will be no flow of air or gas through the opening 42 between 42 and 41. The opening 42 between'the regenerator 42 and flue 44 and the regenerator 43 and flue 41 respectively are of such area that the loss of pressure of the air and, gases passing through these openings is the same, hence there will be no pressure difi'erencebetween fiue 44 and re-.

generator 43 and no air will pass this way to the, regenerator 43. The desired flow of air and waste gas is therefore obtained by the use of a single nozzle which is pull-.

ing the waste gases from the melting chamber at all times. The reversal of flow of the gases through the regenerators is accomplished by simply reversing the stack valves and the flow of combustion air from the fan. I

Instead of using the waste gases under pressure to create the necessary pressure differences in the system, hot air can also be used and various other instrumentalities parting from the invention and combinations than those indicated in f the drawings and described herein can be used to perform the functions set forth without departing from the invention a defined in the appended claims' The gases used to create the necessary pressure differences can be introduced at other locations than those shown. andgases other than waste gas can be used. For example, either cold or hot air can be introduced in the flue 44 between the regenerators and the burners or fuel gas can be introduced under pressure through the burners themselves. I

In the foregoing description, I have referred to the furnace as an open hearth fur- I nace, and have described the method with certain references to passing the flame or gases through the'melting chamber. It is to be-under-stood, however,-that my invention is applicable to other furnaces in which nomelting takes place,'such as furnaces for heating blooms, billets and thelike. -Thc term open hearth furnace as used in the claims is intended to cover'such other furnaces,rand the term ,melti'ng chamber is 1n.-.

tended to cover also .a heating chamber-in which no melting necessarily takes place;

. Though I have described with great pan ticularity' the steps ofqmy improved-method aifd details-of the apparatus for embodying the invention,.it'- is not to be construed that I am limited thereby as changes maybe made by thoseskilled inthe art. without deas defined in the appended claims. 1 v

lVhat I claim is: 1. The method of controlling communication between the melting chamber of ametallurgicalfurnace and a regenerator through a port WhlCh is always open, which gmeltin g chamber consists in directing a jet of gas toward the open port to practically or substantially 3. In combination with a furnace, a pair of regenerators, means for supplying ai-r thereto, a flue connectmg the regenerators,.

normally openports connecting said flue with each of said regenera'tors, normally open ports connecting each regenerator with the furnace and means for introducing a jet of gas toward certain of said ports to alternately control the circulation of air through one of said regenerators to the fur nace and the passage of waste gases from the furnace. j

4. In I combination with an open hearth furnace, "a pair of regenerators, passages which are always open connecting the fur nace with said regenerators, and means for introducing jets of gas to control the circu lation of combustion air and waste gas through said passages, the regenerators and the furnace.

5. In combination with an open hearth furnace and: regenerators communicating therewith, means for causing the flame to pass constantly through the melting chamber of the furnace in the same direction comprisingmeans for alternately-supply ing air to each regenerator, flues connecting the regenerators with the furnace atone end, ports at the opposite end of the furnace communicating with said regenerators and means for directing jets of gas so as to permit the flow of the air and waste gases through certain of said ports and flues and prevent the flues. i

furnace, pair of air regenerators, a flue connecting said regenerators, aport leading from said fine tothe melting-chamber of v the furnace, ports connecting said flue with I each of said regenerator-s, other ports'conflow through other ports and -6. In combination with an" open hearthnecting the-regenerators with the fuel inletv end of the melting chamber, means for. alter- 'nately supplylngairjto each of said regenerators and means for directing jets ofwaste' gas toward certain of said ports soas to* a'lternatelyjpermit the I air to pass through oneof said regene'ratorsl to .the {melting erator. a 1

7. In combination with an openv hearth furnace, a'pa1r of regenerators' and :means,

chamber and the waste gas to passfron the through the other regennace in the same direction withoutthe use 1 of valves in the ports leading thereto, comprising flues for alternately supplying air and withdrawing waste gases from the regenerators, a flue connecting the regenerators, a vport at the outflow end of the melting chamber connected with said flue, Ve-nturi shaped ports connecting each of the regenerators with said flue, Ventu-ri shaped ports connecting the regenerators with the fuel inlet end of the melting chamber, nozzles opposite each of said Venturi shaped ports, means for discharging a fluid through said nozzles and Valves for cutting off the supply of fluid to certain of said nozzles.

8. In combination with an open hearth furnace, a pair of regenerators, a plurality of Venturi shaped ports through which the combustion air andwaste gases pass respectively to and from the furnace, and means associated with each of said ports for directing a jet of fluid toward certain selected ports so as to determine which portsthe air and waste gas will traverse.

9. The method of controlling communication between a chamber in a furnace and a regenerator through a port which is'always open, which consists in directing a jet of munication between the chamber and the regenerator through said port.

10; .In combination with a furnace and the 'regenerators thereof, means for utilizing fluid jets at diflerent locations to exert ust sufficient pressure to control the circulation of the combustion air and waste gas through.

the regenerators and the furnace without theuse of valves in the flues which said combustion air and waste gas traverse.

11. In combination with auni-diredtional furnace and the regenerators communicatmg therewith, means causing the combustion.

gases to pass constantly through the melting chamber of the furnace in the same 'direcmunicating with passages leading to said regenerators, and means for creating a' pressure difference between certain ports so ask to cause the flow of air and waste gas through certain of "said ports and'flues and preventthe flow through other ports and flues, without the use of valves located in the ports and flues which the gas and airtrav'erse. v 1 v p In witness whereof, I have hereunto signed my name.

WALDEMAR Dress-EN;

Images