US3752638A - Bottom of a shaft furnace, a shaft furnace provided with such a bottom and a method for cooling such a bottom - Google Patents

Bottom of a shaft furnace, a shaft furnace provided with such a bottom and a method for cooling such a bottom Download PDF

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Publication number
US3752638A
US3752638A US00209089A US3752638DA US3752638A US 3752638 A US3752638 A US 3752638A US 00209089 A US00209089 A US 00209089A US 3752638D A US3752638D A US 3752638DA US 3752638 A US3752638 A US 3752638A
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US
United States
Prior art keywords
layer
graphite
lambda
bottom construction
cooling
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Expired - Lifetime
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US00209089A
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English (en)
Inventor
K Etzel
B Hoogendoorn
Laar J Van
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KONINKLYKE NEDERLANDSCHE NL
KONINKLIJKE HOOGOVENS EN STAAL
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KONINKLIJKE HOOGOVENS EN STAAL
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B7/00—Blast furnaces
    • C21B7/10—Cooling; Devices therefor
    • C21B7/106—Cooling of the furnace bottom

Definitions

  • ABSTRACT A shaft furnace, e. g., blast fumace for iron manufacture, having liquid cooling of its periphery and air cooling of its bottom which contains a horizontal layer of refractory material with aheat conduction coefficient A (cal/m/h/C) which under operating conditions is higher than 20, includes the improvement that said layer is enclosed between upper and lower layers of re fractory of much lower heat conducting coefficient A.
  • the thicknesses of said upper and lower layers are preferably such that only to 60 percent, more preferably to 40 percent, of the heat discharge through the intermediate layer is transmitted to the lower layer; the periphery of the bottom being kept at about C.
  • the intermediate layer may consist of graphite with a A-value of to the lower, of refractory e. g., carbon bricks, of a )t-vslue of 2 to 5; and the upper layer of refractory, e. g., semi-graphite, may have a )t-value of 20 to 30.
  • liquid cooling in this specification and in the claims not only means spray cooling, but also evaporation cooling and cooling by convection.
  • the bottom In a blast furnace the bottom is subjected to a continuous heavy thermal load as a result of the quantity of liquid iron present immediately on top of this bottom.
  • the temperature in the zone of the tap hole is about l,400 to l,500 C.
  • the bottom should be resistant against such high temperatures, but moreover it has the function to support a considerable part of the blast furnace structure and the contents thereof.
  • a complication for blast furnace bottoms consists in that they are gradually attacked by the liquid iron. It may be said that for most refractory matrials used for the bottom this liquid iron has the tendency to penetrate into it to a depth where the temperature of this bottom material about corresponds to the solidification temperature of the iron, which is l,l20 to 1,140 C. The zone above this temperature limit will gradually be attacked and deteriorated, so that the said temperature limit is displaced downwardly until a situation of equilibrium has been reached.
  • the so-called salamander a temperature gradient is found over the height thereof.
  • This salamander is filled from above to its lower end with liquid iron and in part possibly with solidified iron, and often also in part with a coke matrix.
  • the present invention aims at giving a structure which does not show the disadvantages of such known structures and which nevertheless only forms a salamander of small dimensions and particulary of small height.
  • the invention is characterized in that the bottom contains a horizontal layer of refractory material in a manner known as such, with a heat conduction coefficient A under operating conditions meeting the requirement that it be higher than 20 kcal/m/h/C, and that this layer at: its upper and lower surface is enclosed by an upper layer and a lower layer of refractory material with a very much lower heat conduction coefficient A than the first said intermediary layer.
  • the refractory upper layer has primarily as its function to protect the intermediary layer positioned below it. This is so because said last layer is made from a material which usually is much more expensive than usual refractory materials.
  • this thermally high conductive intermediary layer it is according to the invention preferred to use graphite with a heat conduction coefficient of 60 to 100 kcal/m/h/C.
  • the temperature of the graphite layer is decreased to below the melting temperature of the iron, so that it is avoided that the salamander is able to penetrate into the graphite layer.
  • the lowermost layer which again consists of a less conductive material, restricts the heat flow to and through the steel bottom slab. The remainder of the heat is thereby discharged to the periphery of the graphite layer, where the temperature is kept low by liquid cooling.
  • An important advantage of the structure and the method according to the invention moreover consists in that even for very large furnaces a cooling by air of the lower side of the bottom is possible. The considerable risks of water cooling in that zone are thus avoided.
  • the invention not only relates to the bottom structure and the method as described above for cooling thereof, but in particular also to shaft furnaces and in particular to blast furnaces for iron production, which are provided with such novel bottoms. It has appeared that it is possible to design such furnaces with lighter weight and that the controllability of the bottom temperature is more simple than in other comparable furnaces.
  • the thermal resistance is higher (e.g., by a low A)
  • the bottom slab will be cooler, but the salamander will also be deeper.
  • the temperature of the bottom slab below the lower layer will increase, but the salamander will be less deep and more plane.
  • reference numeral 1 indicates a steel jacket around a refractory bottom structure. This jacket merges into a steel bottom slab 2, resting on a structure with supporting steel beams 3.
  • the bottom itself is built up of three layers 4, 5 and 6.
  • the upper layer 4 with a thickness of 60 cm consists of semigraphite. Of this semi-graphite the heat conduction coefficient )t is about 20 kcal/m/hlC.
  • Layer 5 has a thickness of 120 cm and consists of graphite with a k of about 90 kcal/m/h/C.
  • Layer 6 has thickness of 60 cm and consists of carbon bricks with a A of about 4 kcal/m/h/C.
  • the said values relate to the values under operating conditions and temperatures.
  • the furnace diameter in the furnace hearth is about 13 in.
  • a fan not shown with a power of 100 horse power serves to cool the steel bottom slab by air to keep its temperature below 100 C.
  • the total quantity of heat 0,, discharged through layer 5 is divided into two components.
  • Heat flow Q through the bottom slab 2 is about 200,000 kcal/h and the quantity of heat Q discharged through the jacket part of layer 5 is about 240,000 kcal/h.
  • the temperature within the furnace is about 1,400 to 1,500 C.
  • the isotherm for 1,100 C does not reach the upper side of layer 4, which is an indication that no salamander is able to form and that the bottom is not attacked.
  • a bottom construction of a blast furnace or the like which comprises, in combination:
  • said intermediate layer having a heat conduction coefficient A, which under operating conditions, is higher than kcal/m/h/C, and
  • said heat conduction coefficient of said intermediate layer being substantially higher than those of said upper and lower layers.
  • a bottom construction as claimed in claim 1, said upper, intermediate and lower layers having A values of about 2 5, 80 and 4 kcalIm/hPC, respectively, and thicknesses of about 60, and 60 centimeters, respectively.
  • a bottom construction as claimed in claim 8 said upper, intermediate and lower layers being semigraphite, graphite, and carbon-brick layers, respectively.
  • a bottom construction as claimed in claim 9 there being a fourth layer interimposed on said upper layer, said fourth layer being a magnesite layer and having a thickness of about 35 centimeters.
  • a bottom construction as claimed in claim 1 the A values and thicknesses of said upper, intermediate and lower layers being such that the ratio of heat flows from the intermediate layer to said metal jacket and to said metal bottom plate, respectively, lies in the range of 80:20 to 40:60. r

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Blast Furnaces (AREA)
US00209089A 1970-12-18 1971-12-17 Bottom of a shaft furnace, a shaft furnace provided with such a bottom and a method for cooling such a bottom Expired - Lifetime US3752638A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL707018539A NL148939B (nl) 1970-12-18 1970-12-18 Bodem van een schachtoven, in het bijzonder van een hoogoven voor ijzerproduktie.

Publications (1)

Publication Number Publication Date
US3752638A true US3752638A (en) 1973-08-14

Family

ID=19811845

Family Applications (1)

Application Number Title Priority Date Filing Date
US00209089A Expired - Lifetime US3752638A (en) 1970-12-18 1971-12-17 Bottom of a shaft furnace, a shaft furnace provided with such a bottom and a method for cooling such a bottom

Country Status (12)

Country Link
US (1) US3752638A (mo)
JP (1) JPS5113441B1 (mo)
BE (1) BE776848A (mo)
BR (1) BR7108396D0 (mo)
CA (1) CA952310A (mo)
DE (1) DE2162893C3 (mo)
FR (1) FR2118177B1 (mo)
GB (1) GB1349036A (mo)
IT (1) IT943292B (mo)
LU (1) LU64474A1 (mo)
NL (1) NL148939B (mo)
ZA (1) ZA718323B (mo)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0040440A3 (en) * 1980-03-21 1982-02-03 Hoogovens Groep B.V. A shaft furnace, particularly the refractory construction of the bottom thereof
US4565525A (en) * 1983-05-26 1986-01-21 Hoogovens Groep B.V. Taphole construction of a shaft furnace
US4960379A (en) * 1988-02-06 1990-10-02 Dango & Dienenthal Maschinenbau Gmbh Process and apparatus for opening furnace tapholes
US5020992A (en) * 1989-09-25 1991-06-04 Hoogovens Groep B.V. Shaft furnace
US5230617A (en) * 1991-09-25 1993-07-27 Klein Ernst G Furnace shell cooling system
US5601427A (en) * 1994-07-25 1997-02-11 Daidotokushuko Kabushikikaisha Waste melting furnace and a method of melting wastes
WO2014140901A3 (en) * 2013-03-14 2015-02-19 Abdallah Nouri Directional solidification system and method
US9352389B2 (en) 2011-09-16 2016-05-31 Silicor Materials, Inc. Directional solidification system and method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2673083A (en) * 1952-04-01 1954-03-23 Union Carbide & Carbon Corp Cooling apparatus for blast furnace hearths
US2859030A (en) * 1955-08-08 1958-11-04 Ernest B Snyder Blast furnace spray cooling means with disposal shed

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1937940A (en) * 1930-05-03 1933-12-05 Brassert & Co Bottom for boiler furnaces
US1940115A (en) * 1930-10-08 1933-12-19 Republic Carbon Company Bottom for slag tap furnaces
DE1281464B (de) * 1961-08-21 1968-10-31 Harbison Walker Refractories Feuerfeste Auskleidung fuer Sauerstoff-Stahlkonverter
DE1583198A1 (de) * 1967-10-27 1970-07-23 Thyssen Huette Ag Hochofenboden

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2673083A (en) * 1952-04-01 1954-03-23 Union Carbide & Carbon Corp Cooling apparatus for blast furnace hearths
US2859030A (en) * 1955-08-08 1958-11-04 Ernest B Snyder Blast furnace spray cooling means with disposal shed

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0040440A3 (en) * 1980-03-21 1982-02-03 Hoogovens Groep B.V. A shaft furnace, particularly the refractory construction of the bottom thereof
US4371334A (en) * 1980-03-21 1983-02-01 Estel Hoogovens Bv Shaft furnace, particularly the refractory construction of the bottom thereof
US4565525A (en) * 1983-05-26 1986-01-21 Hoogovens Groep B.V. Taphole construction of a shaft furnace
US4960379A (en) * 1988-02-06 1990-10-02 Dango & Dienenthal Maschinenbau Gmbh Process and apparatus for opening furnace tapholes
US5020992A (en) * 1989-09-25 1991-06-04 Hoogovens Groep B.V. Shaft furnace
US5230617A (en) * 1991-09-25 1993-07-27 Klein Ernst G Furnace shell cooling system
US5601427A (en) * 1994-07-25 1997-02-11 Daidotokushuko Kabushikikaisha Waste melting furnace and a method of melting wastes
US9352389B2 (en) 2011-09-16 2016-05-31 Silicor Materials, Inc. Directional solidification system and method
WO2014140901A3 (en) * 2013-03-14 2015-02-19 Abdallah Nouri Directional solidification system and method
CN105229206A (zh) * 2013-03-14 2016-01-06 希利柯尔材料股份有限公司 定向凝固系统和方法
US9663872B2 (en) 2013-03-14 2017-05-30 Silicor Materials, Inc. Directional solidification system and method
CN105229206B (zh) * 2013-03-14 2019-03-26 希利柯尔材料股份有限公司 定向凝固系统和方法

Also Published As

Publication number Publication date
GB1349036A (en) 1974-03-27
DE2162893A1 (de) 1972-07-13
DE2162893B2 (de) 1976-04-29
CA952310A (en) 1974-08-06
FR2118177A1 (mo) 1972-07-28
AU3704271A (en) 1973-06-21
LU64474A1 (mo) 1972-06-20
BR7108396D0 (pt) 1973-05-29
JPS5113441B1 (mo) 1976-04-28
NL148939B (nl) 1976-03-15
FR2118177B1 (mo) 1975-08-29
IT943292B (it) 1973-04-02
NL7018539A (mo) 1972-06-20
DE2162893C3 (de) 1981-04-30
BE776848A (fr) 1972-06-19
ZA718323B (en) 1972-09-27

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