US3380723A - Blast air heating stove in metallurgical furnaces and the like - Google Patents
Blast air heating stove in metallurgical furnaces and the like Download PDFInfo
- Publication number
- US3380723A US3380723A US504820A US50482065A US3380723A US 3380723 A US3380723 A US 3380723A US 504820 A US504820 A US 504820A US 50482065 A US50482065 A US 50482065A US 3380723 A US3380723 A US 3380723A
- Authority
- US
- United States
- Prior art keywords
- air
- chamber
- stove
- combustion
- heat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
- F28F21/04—Constructions of heat-exchange apparatus characterised by the selection of particular materials of ceramic; of concrete; of natural stone
Definitions
- a blast air heating stove is provided with a combustion chamber at the top of the stove which is of a conical configuration and includes a slide valve which determines the degree of mixing of the fuel and air within the combustion chamber, such mixing determining the rate of flame propagation and flame length.
- the blast air heating stove does not require preheat of air or gas for attaining the proper flame speed, flame propagation, and so forth.
- This invention relates to an improved blast air heating stove for metallurgical furnaces and the like, and to a combination of such a stove with a burner and combustion chamber which is capable of more efficiently heating air which is passed through the stove in conjunction with metal-producing operations.
- What the present invention proposes is to eliminate the vertical combustion chamber Within the stove and install additional checkers in its stead.
- the entire void above the checkers to the top of the refractory lined cone is made a part of a large burner.
- On the top of the cone is an especially designed gas/ air mixer to give a very rapid and thorough mixing of the two materials which will produce a stable flame retention despite the leanness of the gas even at high input rates. Such rates of burning are not possible in present vertical combustion chambers.
- the heat of the fully combusted products will give an absolutely uniform distribution as it enters the checkers. Also, due to the nature of the air/ fuel mixing mechanism of the burner the control of flame length is such that it can be lengthened or shortened as may be desired.
- novel regulating means for controlling the rate of burning as well as such parameters as intensity of burning and flame propagation to achieve the optimum generation of heat during the heat-up cycle of the refractory packing, which is then followed by a blast of air which is increased in temperature by sweeping over the previously heated refractory packing.
- An important object of the present invention is to produce a stove having a greater quantity of checkerwork by reason of eliminating the vertical heating chamber previously present and thereby adding heat capacity to the stove.
- An important feature of the present invention is utilizing an improved heating chamber which provides greater uniformity of heating, higher temperatures, faster recovery and yet is operable with leaner fuels and higher temperatures, all of this being accomplished without sacrifice of service life of the checkers or requiring any added maintenance.
- FIGURE 1 is an elevation view, showing in section the heat exchanger, including the packing and combustion chamber;
- FIGURE 2 is a section view taken on line 22 of FIGURE 1;
- FIGURE 3 is a top view of the structure shown in FIGURE 1, looking in the direction of the arrows 33;
- FIGURE 4 is a section view taken on line 4-4 of FIGURE 1;
- FIGURE 5 is a graph illustrating, in relative units, the temperature rise of air versus the height of the tower.
- a heat exchanger designated generally by reference numeral includes a tower 12 comprised of a shell 14 having a liner 1'6 of suitable heat resistant refractory composition. Within the shell is a packing designated gene-rally by reference numeral 18 and comprised of a plurality of ceramic heat-resistant refractory bodies referred to as checkerwork and which are capable of being heated up and storing heat and for thereafter imparting it to a blast of air which is introduced through the heat exchanger.
- the refractory mass 1-8 is supported on a plurality of pedestals 20, or the like, which vertically support the mass of refractory checkers which are spaced to provide flow paths for the gaseous combustion products which flow downwardly and the flow of air which passes through the stove in a manner to be described.
- the pedestals 20 not only support the refractory packing 18 but also define a chamber 22 having an inlet 24 for the updraft of air which is passed vertically upwardly through the mass of heated refractory to initiate the flow of air for preheating and an outlet opening 26 for the exhaust products gene-rated in combustion chamber 28 during heat-up of the refractory packing 18.
- the chamber 28 surmounts the tower 12 and is preferably of frusto-conical construction, being of brickwork or other suitable heat resistant refractory composition brick, or the like, 30.
- the burner chamber 28 is frusto-conically constructed and this is the configuration recommended for best results; however, other shapes, such as spherical,
- a combination of fuel which is injected from a conduit 36, having an outlet 34.
- the fuel being blast furnace gas, or the like, is at the time of being injected, in the proper physical form for burning.
- the combustion-supporting gas for burning the fuel is in the form of air and such combustionsupporting gases are introduced through an inlet line 32 having a control valve 75.
- the inlet 40 for the fuel is controlled by an arcuate gate 42 (FIGURE 4). Depending u-pon the position of the gate 42 there will be introduced a precise, controllable rate and direction of flow of fuel indicated by the arrows 44 and 46.
- the inflow of fuel tends to follow a swirling, vortexing movement and a sub-pressure zone is created at the central portion 48 of the inlet chamber 50.
- Such differential pressure action tends to draw the air material into it and creates flow paths indicated by reference numeral 52 (FIGURE 1) within chamber 28.
- the burning action is highly controllable and unlike other previously used for firing stoves will not scour or damage either the sidewalls of the upper chamber or the checkerwork.
- the cone shaped burner chamber is configured so that the gases are permitted to expand and completely burn but without such combustion occurring within the checkerwork to cause its damage.
- the fuel and the air which describes a downwardly spiraling or vortexing path from chamber 50 into chamber 28, produces a turbulence between the two materials, thoroughly mixing them and causing the two to ignite.
- the ignition is within chamber 28 and the interior walls 53 of the frusto-conically shaped chamber 30 promote such combustion and at a rapid and efficient rate. Flame which is propagated by the combustion is controllable by the gate 42. For example, under high inflow rate and high volume inflow the vacuum which is produced is of a higher degree and the combustibles are drawn vertically higher and burning occurs at a higher level within chamber 28. Conversely, by decreasing the flow rate and decreasing the volume, mixing and combustion occurs at a lower level within chamber 28.
- the tower Since the entire cross section of the tower is filled with refractory heat-absorbing media the tower is now more efiicient in imparting higher temperatures to a flow of air which is next passed upwardly through the tower from inlet 24 and following completion of the combustion within chamber 28. It was previously the practice to use a portion of the vertical cross section as a combustion chamber and to that extent there was unavailable the heat-absorbing refractory media which was capable of heating the air or other upblast material intended for use in the steel-making operations. Now such area is filled with checkerwork.
- the present invention it is possible to regulate the ratio of fuel to air both by means of controlling the valve 38 and by means of controlling the rate of injection of air from line 32 and, knowing the burning rate and rate of generation of heat, it is possible to regulate the position of the gate 42 to properly position the occurrence of burning within chamber 28 and prevent flame propagation below the level of the heat-absorbing media which, as previously described, is comprised of a plurality of heat-absorbing ceramic or checkerwork 18.
- the pellets absorb the heat and the products of combustion are dissipated vertically downwardly leaving the system through port 26 and are vented to atmosphere through a stack, or the like (not shown).
- the burning operation is terminated and this is followed by an air upblast and the air, as it passes through the heated refractory media which is formed as a packing within the tower, will become heated and elevated in temperature. Since the upper portion of the checkerwork performs the greatest heating function it is highly advantageous that in the present invention this is the portion which is directly heated by combustion and is therefore at a higher temperature and is therefore best capable of imparting higher degrees of heating temperature to the air as it progresses upwardly and becomes successively hotter.
- the described burner system is capable of use with leaner fuels and ones which require thorough and intimate mixing of the air and fuel.
- the invention is also useful in retrofitting existing stoves. It has been found that the capacity of stoves can be materially increased, and without expensive alteration, by merely removing the existing combustion chamber from within the confines or envelope of the tower and filling such voided space with checkerwork and then disposing the heating chamber at the top of the tower within a frusto-conical combustion chamber or spherical combustion chamber, according to the preference of the builder. The conditions of combustion are then accurately controlled by regulating the inflow of combustible material or fuel, the inflow of air according to rate and amount to properly complete the process of combustion and regulate the propagation of flame within precise bounds.
- the present invention is useful, of course, not only in the metal-producing industry but in many other industries as well where it is desired to supply substantial flows of heated gases in large amounts and rates and where such heating can be accomplished in an economical and safe manner.
- the composition of the ceramic packing is not, it should be understood, essential to the present invention; any particular refractory packing, which is heat absorbent, stable and is capable of supporting its vertical weight i satisfactory so long as such refractory packing will develop flow paths so that the products of combustion can flow downwardly and the air inblast can move upwardly through the packing to be heated thereby. It is also essential, of course, that such refractory material has sufficient heat resistivity that it will not disintegrate under exposure to high heat and will not fuse or become joined together to plug the flows upwardly and downwardly, respectively, within the tower.
- An improved stove for heating air in metal-producing operations and the like comprising a shell: a quantity of heat-absorbing refractory bodies contained in said shelland adapted to receive and store heat therein, means for selectively circulating a flow of hot, inert gases through said shell and which sweep over said refractory bodies to impart heat thereto, a conically shaped combustion chamber surmounting said shell and forming an upper chamber of said stove, a burner including an adjustable fuel/air mixer having means adapted to propagate a flame which is generated from a flow of fuel and air circulated spirally within said combustion chamber to effect the flame which substantially fills but is unimpinging against the refractory bodies contained in said shell, and means for circulating in a counterflow manner through said shell and refractory bodies a flow of air which is heated by sweeping over the mass of said r fractory bodies.
- An improved stove for heating air in metal-producing operations and the like comprising a shell: a quantity of heat-absorbing refractory bodies contained in said shell and adapted to receive and store heat therein, means for selectively circulating a flow of gases through said shell and which sweep over said refractory bodies to impart heat thereto, a conically shaped combustion chamber surmounting said shell and having an adjustable fuel/ air mixer having means adapted to propagate a flame which is generated from a flow of said fuel and air circulated spirally within said combustion chamber to effect a flame which substantially fills but is unimpinging against the refractory bodies contained in said shell, means for circulating upwardly through said shell and refractory bodies a flow of air which is heated by sweeping over the mass of said refractory bodies and means providing an outlet for the combustion gases which are circulated downwardly through said stove in countercurrent relation with the air which is circulated upwardly through the refractory bodies when the combustion operation has terminated.
- An improved stove for heating air in metal-producing operations and the like comprising a shell: a quantity of heat-absorbing refractory bodies contained in said shell and adapted to receive and store heat therein, means for selectively circulating a flow of gases through said shell and which sweep over said refractory bodies to impart heat thereto, a conically shaped combustion chamber surmounting said shell and having a burner adapted to propagate a flame which is generated from a flow of said fuel and air circulated spirally within said combustion chamber to effect a flame which substantially fills but is unimpinging against the refractory bodies contained in said shell, means for circulating upwardly through said shell and refractory bodies a flow of air which is heated by sweeping over the mass of said refractory bodies, said burner including means for injecting fuel vertically downwardly within the center of said combustion chamber, and means for providing a flow of combustion-supporting air which is caused to flow circularly around the interior surface of the said conical chamber along a spiral path therein, the flow rate and speed of said combustion
- a heating stove for providing a flow of air in heated condition for metal-producing operations, comprising in combination: support means defining a generally vertically extending heating chamber, a plurality of heat absorbing elements froming a relatively loose mass of such elements which provide flow paths therebetween, means defining an air inlet to provide a flow of air which is directed upwardly through the mass of heated articles and is heated thereby, a generally frusto-conically shaped combustion chamber at the upper end of said stove which provides a location of burning for generating heat for raising the temperature of said heat-absorbing elements, and a burner disposed in said chamber and having an inlet port which directs combustion-supporting gas tangentially relatively to the interior surface of said chamber and which spirally follows such interior chamber wall, fuel supply means adapted to inject fuel centrally in relation to said spiral inlet flow of combustion-supporting gas, and regulating means for controlling the rate of input flow of fuel and combustion-supporting gas to control the flame propagation and flame length within said combustion chamber.
- a heating stove for providing a flow of air in heated condition for metal-producing operations, comprising in combination: support means defining a generally vertically extending heating chamber, a plurality of heat absorbing elements forming a relatively loose mass of such elements which provide flow paths therebetween, means defining an air inlet to provide a flow of air which is directed upwardly through the mass of heated articles and is heated thereby, a combustion chamber disposed generally collinearly with the mass of heat-absorbing elements and located at the upper end of the stove to provide a location of burning which generates heat for raising the temperature of said heat-absorbing elements, and a burner disposed in said chamber and having an inlet port which directs combustion-supporting gas tangentially relatively to the interior surface of said chamber and which spirally follows such interior chamber wall, fuel supply means adapted to inject fuel centrally in relation to said spiral inlet flow of combustion-supporting gas to control the flame propagation and flame length within said combustion chamber, and regulating means for controlling the rate of input fiow.
- An improved heating chamber for use in combination with a stove adapted for heating air in metal-producing operations and the like, comprising means defining an internal combustion chamber adapted for surmounting a vertical heating stove and defining the upper portion of said stove, means for injecting fuel interiorly of said chamber in combustible form and extending substantially centrally of said chamber, means providing an inlet flow of combustion-supporting gases which are caused to move tangentially of the interior surface of said chamber, and regulating means for determining the rate of inflow of such combustion-supporting gases to control the extent of flame propagation within said chamber.
- An improved heating chamber for use in combination with a stove adapted for heating air in metal-producing operations and the like, comprising means defining an internal combustion chamber adapted for surmounting a vertical heating stove and defining the upper portion of said stove, means for injecting fuel interiorly of said chamber in combustible form and extending substantially centrally of said chamber, means providing an inlet flow of combustion-supporting gases which are caused to move tangentially of the interior surface of said chamber, regulating means for determining the rate of inflow of such combustion-supporting gases to control the extent of flame propagation within said chamber, and control means for regulating the inlet flow of injected fuel.
- An improved heating chamber for use in combination with a stove adapted for heating air in metal-producing operations and the like, comprising means defining an internal combustion chamber adapted for surmounting a vertical heating furnace and defining the upper portion of said furnace, means for injecting fuel interiorly of said chamber in combustible form and extending substantially centrally of said chamber, means providing an inlet flow of combustion-supporting gases which are caused to move tangentially of the interior surface of said chamber, and regulating means for determining the rate of inflow of such combustion-supporting gases to control the extent of flame propagation within said chamber, said flame propagation being controlled to be confined entirely within said chamber and unimpinging against the stove in proximity therewith.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Ceramic Engineering (AREA)
- Air Supply (AREA)
- Gas Burners (AREA)
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US504820A US3380723A (en) | 1965-10-24 | 1965-10-24 | Blast air heating stove in metallurgical furnaces and the like |
GB42832/66A GB1163142A (en) | 1965-10-24 | 1966-09-26 | Improvements in or relating to Air Heating Stoves. |
SE13123/66A SE316788B (xx) | 1965-10-24 | 1966-09-29 | |
NL6614027A NL6614027A (xx) | 1965-10-24 | 1966-10-05 | |
ES0332120A ES332120A1 (es) | 1965-10-24 | 1966-10-10 | Un dispositivo de estufa para calentar aire en operaciones de produccion de metal y similares. |
BE688273D BE688273A (xx) | 1965-10-24 | 1966-10-14 | |
LU52191D LU52191A1 (xx) | 1965-10-24 | 1966-10-18 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US504820A US3380723A (en) | 1965-10-24 | 1965-10-24 | Blast air heating stove in metallurgical furnaces and the like |
Publications (1)
Publication Number | Publication Date |
---|---|
US3380723A true US3380723A (en) | 1968-04-30 |
Family
ID=24007882
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US504820A Expired - Lifetime US3380723A (en) | 1965-10-24 | 1965-10-24 | Blast air heating stove in metallurgical furnaces and the like |
Country Status (7)
Country | Link |
---|---|
US (1) | US3380723A (xx) |
BE (1) | BE688273A (xx) |
ES (1) | ES332120A1 (xx) |
GB (1) | GB1163142A (xx) |
LU (1) | LU52191A1 (xx) |
NL (1) | NL6614027A (xx) |
SE (1) | SE316788B (xx) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1689042A (en) * | 1926-08-09 | 1928-10-23 | Frank R Mcgee | Hot-blast stove |
US1770277A (en) * | 1928-10-13 | 1930-07-08 | Frank R Mcgee | Control mechanism for hot-blast stoves |
US1942762A (en) * | 1932-03-14 | 1934-01-09 | Frank R Mcgee | Hot blast stove |
US3082995A (en) * | 1960-12-21 | 1963-03-26 | United States Steel Corp | Apparatus for heating blast furnace stoves |
-
1965
- 1965-10-24 US US504820A patent/US3380723A/en not_active Expired - Lifetime
-
1966
- 1966-09-26 GB GB42832/66A patent/GB1163142A/en not_active Expired
- 1966-09-29 SE SE13123/66A patent/SE316788B/xx unknown
- 1966-10-05 NL NL6614027A patent/NL6614027A/xx unknown
- 1966-10-10 ES ES0332120A patent/ES332120A1/es not_active Expired
- 1966-10-14 BE BE688273D patent/BE688273A/xx unknown
- 1966-10-18 LU LU52191D patent/LU52191A1/xx unknown
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1689042A (en) * | 1926-08-09 | 1928-10-23 | Frank R Mcgee | Hot-blast stove |
US1770277A (en) * | 1928-10-13 | 1930-07-08 | Frank R Mcgee | Control mechanism for hot-blast stoves |
US1942762A (en) * | 1932-03-14 | 1934-01-09 | Frank R Mcgee | Hot blast stove |
US3082995A (en) * | 1960-12-21 | 1963-03-26 | United States Steel Corp | Apparatus for heating blast furnace stoves |
Also Published As
Publication number | Publication date |
---|---|
ES332120A1 (es) | 1967-11-01 |
BE688273A (xx) | 1967-03-16 |
LU52191A1 (xx) | 1966-12-19 |
GB1163142A (en) | 1969-09-04 |
SE316788B (xx) | 1969-11-03 |
NL6614027A (xx) | 1967-04-25 |
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