US1769863A - Furnace - Google Patents

Description

July l, l930.\

H. E. SMYTHE FURNAC E Filed Jan. 9. 1922 5 Sheets-Sheet 2 July l, 1930, v H, E SMYTHE 1,769,863

' FURNAGE Filed Jan. 9, 1922 ssheetsheef 4 fsw' L755/14 BWM my 1, 1930. M v E, SMYfHE mamas FURNACE Filed Jan- 9' 1922 5 sheets-sheet 5 Patented July l, 1930 UNETED STTES Pari-:nr orifice y HORACE E. SMYTHE, 0F PITTSBURGH. PENNSYLVANIA. ASSIGNOR, BY MESNE ,ASSIGN- MENTS, TO OPEN HEARTH COMBUSTION COMPANY, A CORPORATION OF NEW JERSEY FURNACE Application filed January 9,1922. Serial No. 527,985.

My invention relates to open hearth melting furnaces of the regenerative type.

In the usual construction of such furnaces,

the two gas regenerators are placed at theopening directly into the. melting chamber.V

ByI my invention the gas is conveyed up through straight vertical passages directly in front of, and in the line of the travel of, one or more air passages which also come up through straight vertical passages at the very ends of the furnace, so that the air and gas are thoroughly mixed prior to their entrance into the melting chamber, the gas traveling from said vertical passages Without hoods or ports and preferably in open troughs to be explained fully hereinafter. Other objects of this invention will bebetter understood after the latter has been described.

Referring to the accozzipanyin'g drawings, Fig. 1 is a vertical section taken centrally and longitudinally through the v melting chamber; Fig. 2. a horizontal section taken 'on the line III- II of Fig. v1; Fig. 3', a horizontal section taken on the line IIL-III of Fig. '1, the upper portion of the figure being a plan view and parts being broken off and the section on the left side being moved toward the right and the gas-valve being omitted; Fig. 4, a vertical section on the line IV--IV of Figs. 1 and 3; Fig. 5, a vertical'section on the line V-V of Fig. 1, the section being continued only slightly into the air reOenerator; Fig. 6, a vertical section on the 2line VI-VI of Fig. 1; Fig. 7, a vertical section on the line VII--VII of Fi 4. 3; Fig. 8, a vertical section on the 'line VI-VIII of Fig. 3; Fig. 9, a vertical section on the line IX-IX'of Fig. 3, with thc gas-valve added; Fig. 10, a central vertical section through one end of a furnace having a modification of my invention; Fig.

11, a horizontal section through one end of a furnace showing a second modification of my invention; and Fig. 12, a vertical section through one end of a furnace showing a third modification of my furnace.

Referring first to Figs. 1 to 9, 1 designates the furnace chamber or melting hearth of a regenerative furnace. As the right and left portions of the structure about to be described are duplicates, I will designate the left-hand parts b numerals and the corresponding rightand parts by the same numeral followed by a letter. Except when deemed necessary or desirable the left side only of the furnace and its accessories will be described, it being understood that the two sides are transposed like the parts of a pair of gloves.

2 is a central air-flue extending up vertically from the air passage 3 to the charnbe-r 4, and 5is a central vertical gas-flue extending up from the gas-passage 6 to the chamber 4 directly in front of the flue 2. 7 and `8 are two auxiliary vertical air-dues, one being in front and the other at the rear of the air-flue 2. They extend down to the air-passage 3 and up to the chamber 4. The gas flue 5 is between the air-Hue 2 and the furnace chamber 1, and the gas-passage 6 is between the air-passage 3 and the center line of the furnace structure, that is, the airiues and passage are ai. the very end of the furnace structure and the gas-flue and passage are nearer the center thereof. The roof 9 of the chamber 4 is inclined down- Wardly toward the chamber 1 and the lateral walls 10 thereof converge toward the said chamber, the roof 9, the walls 10, and the floor 11 of the gas-trough 12 forming a contracted throat or inlet 13 to the melting chamber. At the sides of the trough-floor trough-sides extend only partially up in the chamber 4, forming lateral air-courses 16 between each trough-side and its adjacent side-Wall 10. The roof 9 is extended suilicient-ly toward the center of the furnace to direct fluid from Athe chamber 4 down toward the-bottom or floor of the chamberl.

The air passage 3 is connected to the airregenerator 17 by the 'Hue 13 and the gaspassage 6 is connected to the gas-regenerator 19 by the flue 20. VThe checlrerwork has not been shown in the regenerators as it is well known.

The regenerator 17 is connected by the passage 21 to the valve box 22 and the regenerator 19 is connected by the passage 23 to the port 24. The ports 25. 26, and 26a of the sliding valve 27, when slid to its righthand limit, as shown on Fig. 9, register respectively with the ports 24. 32, and 24, the port 32 communicating below with the stack flue 33. lVhen the valve is slid to its left-hand limit the ports 26, 26, and 25L of the valve register respectively with the ports 24, 32 and 24, the ports 26 and 26a )eing connected by the passage 34 in the valve. The valve has the end passage 28 leading from the port to the gas-inlet port 29 at the top of the valve. The ports 29 and 29a alternatel)Y register with the gasinlet port 30 in the fixed plate 31 covering the ports 29 and 29a and water-sealed in connection therewith.

The passage 21 has the port or valve-seat o ning into the valve-hor or casing 36 whic opens downwardly through the port or valve-seat 37 into the stackhue 33. The valve- seats 35 and 37 are controlled by the mushroom valves 38 and 39 having their stems 40 and 41 extending up through the valve-box 36 and operated by any suitable means.

42 is a blower which delivers a forced blast of air to the supply-pipe 43, the latter leading to the branch pipes and 45a having the dampers or valves 44 and 448. The pipes 45 and 45a lead to( the valve chambers 36 and 36. The valves 44 and 44a are opy erated by the lever 46 and are moved thereby in one direction to have the valve 44 cut off or regulate the air in the branch pi )e 45, and in the o posite direction to have the valve 44 cut o or regulate the air in the branch pipe 45.

The operation of the apparatus shown in Figs. 1 to 9 is as follows: Assuming that the mushroom valves are as in Figs. 7 and 8, and the sliding valve 27 is in the dotted position shown in Fig. 9, and the regenerators 17 and 19* are hot, and the lever 46 is swung as in Fig. 7, air from the blower 42 will be forced through the air-supply pipe 43, the branch pipe 45, the valve-chamber 36, the valve-seat 35, the aiepassage vand the flue 5 to the said chamber 4.

21, the air-regenerator 17a, the air-tine 13'. the air-passage 3fL and the air- lines 7 and 8, to the air and gas mixing chainlim' 4a. At the same time gas flows Jfrom a suitable. source of supply through the inlet portV4 and 29, the end passage 23, the por f and 26a and 24, the gas-passage 23. Vthe I. passage 6a, and the gas-line 5L to the trough o and the chamber 4 where it li been regenerated meets the regenei l whose course has just been traced. Ts A gled gas and air in the chamber 4a having been ignited pass through the trough, the courses 16a, and the throat 132L into the melt ing chamber 1. whence the waste gases pass through the throat 13. to 'the chai'nher fr where they divide. One portion ot the waste gases flows through the air tlues 2. 7. and the passage 3, the flue 13. the regenerator 17, the passage 21, the valve-seat 'the valvecasing 36 and the valveseat 37 to the stachflue 33; The other portion ot the waste, gases iloWs through the A[lue the passage 6. the flue 20, the gas-regenerator 19, the pas sage 23, the ports 24 and the valvepassage. 34. and the portsI 26n and 32 to the said stack-flue 33. rilhe waste gases reheat the regenerators 17 and .19 while the air and gases flowing to the chamber 1 are ahsorbing heat 'from the regenerators 1T* and 19,

In order to reheat the regenerators 17 and 19 and still regenerate the ingoing air and gas, the valve 39 is lowered to its seat 37. the valve 38 remains open. *he valve 39a is opened, the valve 33L remains open` the valve 27 is slid to the full-line position shown on Fig. 9 and the lever 46 is swung to its dot ted position. Air will flow from the blower 42 through the pipe 43, the brauch pipe, 45. the valve-chanlber 36, the valvesseat 35, the passage 21, the hot air-regenerator 17. 'the Hue 18, the passage 3. and the ilues 2. 7. and 8 to the mixer chamber 4. The gas llo-#vs through the ports 30 and 29, the passage r the ports 25 and 24, the passage 23. the gasregcnerator 19, the flue 20, the passage 6, lthe gas and air burn preliminarily in the chanaber 4 and enter the melting chamber l. trom which the waste gases travel to the passages 21a and 23 in the reverse direction to that which the air and Jfuel gas take while llowing to the furnace through the passages, fines and ports bearing the letter a after 'the reference numerals. From the passage 2l the waste gases pass through valve-seatV 55, the valve-chamber 36u, and the valveseat 37 to the stacl-fli1e 33. The waste gases in the passage 23 tion' through the ports 24 and 26a, the passage 34. andthe portsy 26 and 32 to the said stack-line.

Whenl the regcnerators 1T and i9 should be again heated, the several parts are shifted te the original position and the courses incassa first described. The valves are alternately` shifted as long as the furnace is in operation, the Huids flowing therein in a manner apparent from the foregoin description.

Itis seen that the gas ue 5 is directly ahead of the air ilues, being separated from the air before combustion only by the side walls 14 of the tapered trough and by the. low bridge-wall 15.` Thus the air is conveyed directly over and in close contact with the gas for a desirable distance, approxif mately from 3 to 6, before passing through the throat 13 and into the melting chamber where the combustion, begun in the chamber ,4 and particularly in the tapering trough Vor channel c, is completed. By the Aaid of suitable draftand induced pressure, the incoming air and gas are held in the chamber 4 within the confines of walls which converge to the throat 13. The mixed and burning gas and air are thus concentrated in the chamber 4 and forced therefrom at a great velocity which facilitates their mixing, and consequently their combustion, the burning gas and air being impinged directl u on the bath in the chamber 1 whereby t e rnace structure, particularly its limng is given longer life. 4

The end walls of the furnace chamber or hearth slope toward the` throat 13 at an angle of approximately 135 degrees, as shown in Figs. 2 and 11.v The air and gas passages entering at each end of the chamber 1 and at the adjacent portions of the chamber l are so related to the throat as to form approximately a Venturi section.

By locating the air-fines at the ends 'of the furnace and the gas ilues in advance of them, I may use the entire -width of the furnace for the airvflues, as shown inv Fig. 2, where the air- flues 2, 7, and 8 extend entirely across the width of the furnace.

The mushroom valves 38 and 38* may be used to regulate the flow of fluid through their seats.

In Fig. 10, the gas flue may be blocked up or omitted -or used for air, and the fuel gas is supplied through metal pipes 47 (only one shown) extending to the trou h or channel c. The fuel to be used with t 's type of furnace Ais coke-oven-gas, natural gas and gases of a similar nature. In new structures air regenerators only will be used.

` In F ig. 11, I show the end of the furnace contracted in width so that there is but one air ilue 278 having the combined width of the gas channel c and the courses 16, but the width of the air-flue may be varied. With the iue' 5 closed or not used, may be admitted through the pi es 47 s own in dotted lines, the same as in ig. 10.

In Fig. 12, I show how I a apt a furnace of usua construction to my invention. 'A In the said construction the gas-passage 6 leads directly up to the flue 2, which corresponds in osition to the centralair-lue 2 (Fig. 2), an the air-passage 3 leads upwardly and outwardly to air-dues corresponding to the positions of the flues 7 and 8 (Fig. 2). I arrange the gas-flue in front of the air-flue 2 and connect the gas-passage 6 to the flue 5 by the inclined flue-section 6, and I con- .K

nect the air-passage to the air fue 2 and the lues 7 and 8, if present, by an inclined pas sage 3, shown in dotted lines.

I claim 1. A furnace having a central melting chamber and at each end a preliminary com bustion chamber, a pair of air and gas regenerators for each end ofthe furnace, the gasregenerators being betweenl the air-regenerators, means connecting each preliminary combustion chamber toits air-regenerator, the said means extending upwardly at the extreme ends ofA the furnace forthe full width thereof, and an open-top channel in the preliminary combustion chamber leading from the gas inlet to the melting chamber.

2. A furnace having a central melting' chamber and at each end a preliminary combustion chamber, a pair of air and gas regenerators for each end of the furnace, the gasregenerators being between the air-regenerators, means connecting each f preliminary combustion chamber to its air-regenerator, the said -means extending upwardly at the extreme ends of the furnace for the full width thereof, and an open-top channel in the preliminary combustion chamber tapering from the gas inlet to the melting chamat the extreme ends of the furnace for the full width thereof, an open-top channel in the preliminary combustion chamber leading from the gas inlet to the melting chamber, and a bridge-wall across the channel back of the gas-flue.

4. A furnace having a central melting chamber and at each end a reliminary combustion chamber, a pair of) air and gas regenerators for each end of the furnace, the gas-regenerators being between the air-regenerators, means connecting each preliminary combustion chamber to its air-regenerator, the said means extending upwardly at the extreme ends of the furnace for the full width thereof,and an open-top channel in the preliminary combustion chamber leading from 'the gas inlet to the melting chamber, and the sides of the channel being separated from the sides of the pry chamber so as to form the lateral air-courses.

5. A furnace having a central melting chamber and at each end a preliminary combustion chamber, a pair of air and gas regenerators for each end of the furnace, the gas-regenerators being between the air-regenerators, means connecting each prelimi: nary combustion chamber to its air-regenerator, the said means extending upwardly at the extreme ends of the furnace for the full width thereof, and an open-top channel in the reliminary combustion chamber leading fiom the gas inlet to the melting chamber, the preliminary chambers being narrowed toward the melting chamber to form a contracted throat whereby the air and gas are intermingled and their velocity is increased. p

6. In a furnace, a melting chamber, a preliminary combustion chamber communieating withone end thereof, a vertical flue at the outer end of the second chamber to supply air thereto, a `vertical flue between the two chambers to supply gas to the second chamber, and an open-top channel in the second chamber into which channel the gas is delivered ldirectly1 from the gas-flue,

the said channel leadlng to the melting' chamber.

7, An'open hearth furnace comprising a central melting chamber having a relatively restricted port at each end, a mixing chamber at each end of the melting chamber and communicating therewith through "one .of said restricted rts, means for discharging air upwardly into the mixing chamber at the end thereof remote from the restricted port, the width of the air stream being substantially coextensive with the width of the mixin chamber, an open topped channel forme on the bottom of the mixing chamberand extending longitudinally from the point of air discharge to the restricted port, and means for discharging gas into said chanrel.

8. An open hearth furnace comprising a central meltin chamber, a mixing chamberat each eng of the melting chamber the wwidth of which is,-at the furnace end, substantially coextensive with the width of the melting chamber, a relatively restricted port by means of which the mixin chamber is brought into communication with the melting chamber, means for discharging a stream of air u wardly into the mixi chamber at a pomt'remote from the sali port, and means for discharging gas upwardly into said mixing chamber at a int intermediate the point of air deliveryy ereinto, and said port.

9.An o n hearth furnace comprising a central me ting chamber having a relatively restricted port at each end, a mixing cham- 1,7ee,ees

ber at each end of the melting chamber and communicatin therewith through one of said restricts ports, each mixing chamber having means for discharging an upwardly moving stream of air thereinto at a point remote from the restricted port, an open topped channel in the bottom of the mixing chamber and extending longitudinally from the point of air discharge to the restricted port, and means for discharging gas into said channel.

10. An open hearth furnace comprising a central melting chamber having a relatively restricted port at each end, a mixing chamber at each end of the melting chamber and communicating therewith through one of said restricted ports, means for discharging air upwardly into the mixing chamber at the end thereof remote from the restricted port, the width of the air stream being substantially coxtensive with the width of the mixing chamber, and means for discharging gas into the mixing chamber at a point intermediate the point of air discharge into said chamber and said restricted port.

11. In a furnace, a-melting chamber, a preliminary combustion chamber communieating with one end thereof, a vertical flue at the outer end of the second chamber to supply air thereto, a vertical flue between the two chambers to supply gas to the second chamber, and an open-topped channel in the second .chamber into which channel the gas is delivered directly from the gasflue, the said channel leading to the melting chamber and the roof of the second chamber being inclined downwardly toward the first chamber. c

HORACE E. SMYTHE.

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