CA2296516C - Method for monitoring the wear and extending the life of blast furnace refractory lining - Google Patents
Method for monitoring the wear and extending the life of blast furnace refractory lining Download PDFInfo
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- CA2296516C CA2296516C CA002296516A CA2296516A CA2296516C CA 2296516 C CA2296516 C CA 2296516C CA 002296516 A CA002296516 A CA 002296516A CA 2296516 A CA2296516 A CA 2296516A CA 2296516 C CA2296516 C CA 2296516C
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B7/00—Blast furnaces
- C21B7/04—Blast furnaces with special refractories
- C21B7/06—Linings for furnaces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/02—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness
- G01B21/08—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness for measuring thickness
- G01B21/085—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring length, width, or thickness for measuring thickness using thermal means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K17/00—Measuring quantity of heat
- G01K17/06—Measuring quantity of heat conveyed by flowing media, e.g. in heating systems e.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device
- G01K17/08—Measuring quantity of heat conveyed by flowing media, e.g. in heating systems e.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device based upon measurement of temperature difference or of a temperature
- G01K17/20—Measuring quantity of heat conveyed by flowing media, e.g. in heating systems e.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device based upon measurement of temperature difference or of a temperature across a radiating surface, combined with ascertainment of the heat transmission coefficient
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K3/00—Thermometers giving results other than momentary value of temperature
- G01K3/02—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values
- G01K3/04—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values in respect of time
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/02—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples
- G01K7/04—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using thermoelectric elements, e.g. thermocouples the object to be measured not forming one of the thermoelectric materials
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/72—Investigating presence of flaws
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- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
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- Immunology (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Combustion & Propulsion (AREA)
- Blast Furnaces (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
- Manufacture Of Iron (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
Abstract
A method is provided for on-line monitoring of the wear of a refractory lin- ing of a blast furnace. The method in- cludes determining the wear line of the lining from signals provided by tempera- ture probes located in groups, e.g., group (10, 12, 14), group (16, 18, 20), group (22, 24, 26), embedded at spaced loca- tions across the thickness of the refractory lining. Other methods disclosed include: a method of determining the thickness of a protective layer of solidified metal skull formed on the refractory hearth, a method of determining the conditions of heat trans- fer between a refractory lining and a metal shell of a blast furnace and between the metal shell and cooling water applied to the shell, and a method of extending the life of refractory lining.
Description
_.-METHOD FOR MONITORING THE WEAR AND EXTENDING THE LIFE
OF BLAST FURNACE REFRACTORY LINING
Technical Field The present invention relates to a method for extending the life of a blast furnace refractory lining and, particularly to a method which includes on-line monitoring of campaign maximum and current average signals from a plurality of thermocouples embedded at spaced locations in the refractory lining and from a plurality of thermocouples embedded at spaced locations in a metal shell of the furnace, calculating from those signals the wear line of the refractory lining and the thickness of a layer of solidified metal skull formed on an inner surface of the refractory, and then determining the conditions of heat transfer at the shell e.g. whether or not a gap has formed between the refractory and the shell and whether or not water cooling of the shell is sufficient.
Hackcround Apt The iron blast furnace typically is constructed of a metal shell with a refractory brick lining. The life of the refractory brick lining determines.the length of time that the furnace can be kept in operation before the furnace must be shut down for installation of a new refractory. Longer refractory life decreases refractory~cost and increases the productivity achieved from the furnace. More expensive refractory brick have been used to extend the length of a furnace "campaign". Grouting or gunning of refractory material between the refractory brick and the metal shell has also been used as a repair measure to close the gaps which sometimes form between the shell and the brick. Gaps between the brick and shell decrease heat transfer and cause increased wear of the refractory brick.
'.,...;
U. S. Patent 4,510793 discloses the use of a ceramic bar in a furnace wall which wears with the lining. The wear of the bar and tfie.lining is detected ultrasonically by generating ultrasonic pulses in the bar and detecting the reflection of the pulses from the worn inner end of the bar.
Japanese Published Application 1-290709 discloses thermocouples embedded in the refractory on the bottom and bottom side wall part of a blast furnace. From the temperatures measured by the thermocouples, calculations are made.to determine the state of packing of coke in the core of the furnace.
When the packing of coke is inadequate for preferential flow of molten iron in the central part of the furnace, changes are made in the amount, grain size or hot characteristics of the coke charged to the furnace:
U. S. Patent 4,358,953, Horiuchi et al, discloses a method of monitoring the wear of refractory lining blast furnace walls by sensing temperatures at different points across the thickness of the refractory and analyzing the time delay between trigger signals representing internal phenomena of the furnace and the temperature probe output signals. This patent also describes a prior art method of determining the degree of wear from one dimensional heat transfer analysis.
An apparatus for sensing temperature distribution in the refractory is also disclosed. A similar apparatus is disclosed in U. S. Patent 4,412,090, Kawate et al, and in U. S. Patent 4,442,706, Kawate, et al.
It is also known to use one-dimensional and two-dimensional heat transfer calculations to determine refractory temperature distributions and then later compare with measured temperatures to estimate remaining refractory and skull thickness. A method of this type is disclosed in a literature paper entitled "Evaluation of Mathematical Model for Estimating Refractory Wear and Solidified Layer in the Blast Furnace Hearth", by Suh Young-Keun.et al, ISIJ, 1994, Pages 223-228. However, no method previously existed for using measured temperatures to calculate the thickness of the brick and skull directly in a manner which considers interaction between measured temperatures at all locations in a vertical plane simultaneously. Also, no previous method existed that could be used on-line without human_intervention to signal problems with gap formation, inefficient cooling on the shell, and to discern the irregular "elephant-shaped" erosion profiles and "bowl-shaped" erosion profiles, so as to enable corrective measures to be taken during furnace operation in order to extend the life of the refractory.
Other patents related to the measurement of wall thickness and/or temperature include U. S.
2,264,968; 2,987,685; 2,994,219;3,018,663; 3,307,401;
OF BLAST FURNACE REFRACTORY LINING
Technical Field The present invention relates to a method for extending the life of a blast furnace refractory lining and, particularly to a method which includes on-line monitoring of campaign maximum and current average signals from a plurality of thermocouples embedded at spaced locations in the refractory lining and from a plurality of thermocouples embedded at spaced locations in a metal shell of the furnace, calculating from those signals the wear line of the refractory lining and the thickness of a layer of solidified metal skull formed on an inner surface of the refractory, and then determining the conditions of heat transfer at the shell e.g. whether or not a gap has formed between the refractory and the shell and whether or not water cooling of the shell is sufficient.
Hackcround Apt The iron blast furnace typically is constructed of a metal shell with a refractory brick lining. The life of the refractory brick lining determines.the length of time that the furnace can be kept in operation before the furnace must be shut down for installation of a new refractory. Longer refractory life decreases refractory~cost and increases the productivity achieved from the furnace. More expensive refractory brick have been used to extend the length of a furnace "campaign". Grouting or gunning of refractory material between the refractory brick and the metal shell has also been used as a repair measure to close the gaps which sometimes form between the shell and the brick. Gaps between the brick and shell decrease heat transfer and cause increased wear of the refractory brick.
'.,...;
U. S. Patent 4,510793 discloses the use of a ceramic bar in a furnace wall which wears with the lining. The wear of the bar and tfie.lining is detected ultrasonically by generating ultrasonic pulses in the bar and detecting the reflection of the pulses from the worn inner end of the bar.
Japanese Published Application 1-290709 discloses thermocouples embedded in the refractory on the bottom and bottom side wall part of a blast furnace. From the temperatures measured by the thermocouples, calculations are made.to determine the state of packing of coke in the core of the furnace.
When the packing of coke is inadequate for preferential flow of molten iron in the central part of the furnace, changes are made in the amount, grain size or hot characteristics of the coke charged to the furnace:
U. S. Patent 4,358,953, Horiuchi et al, discloses a method of monitoring the wear of refractory lining blast furnace walls by sensing temperatures at different points across the thickness of the refractory and analyzing the time delay between trigger signals representing internal phenomena of the furnace and the temperature probe output signals. This patent also describes a prior art method of determining the degree of wear from one dimensional heat transfer analysis.
An apparatus for sensing temperature distribution in the refractory is also disclosed. A similar apparatus is disclosed in U. S. Patent 4,412,090, Kawate et al, and in U. S. Patent 4,442,706, Kawate, et al.
It is also known to use one-dimensional and two-dimensional heat transfer calculations to determine refractory temperature distributions and then later compare with measured temperatures to estimate remaining refractory and skull thickness. A method of this type is disclosed in a literature paper entitled "Evaluation of Mathematical Model for Estimating Refractory Wear and Solidified Layer in the Blast Furnace Hearth", by Suh Young-Keun.et al, ISIJ, 1994, Pages 223-228. However, no method previously existed for using measured temperatures to calculate the thickness of the brick and skull directly in a manner which considers interaction between measured temperatures at all locations in a vertical plane simultaneously. Also, no previous method existed that could be used on-line without human_intervention to signal problems with gap formation, inefficient cooling on the shell, and to discern the irregular "elephant-shaped" erosion profiles and "bowl-shaped" erosion profiles, so as to enable corrective measures to be taken during furnace operation in order to extend the life of the refractory.
Other patents related to the measurement of wall thickness and/or temperature include U. S.
2,264,968; 2,987,685; 2,994,219;3,018,663; 3,307,401;
3,512,413; 4,217,544; 4,248,809; and 4,539,846.
Disclosure of the Invention This invention relates to a method for extending the life of refractory lining the interior of a metal shell of a blast furnace. The method includes placing thermocouples in the refractory at a plurality of spaced locations and monitoring the signals produced by the thermocouples during furnace operation. An average of the temperature readings at each thermocouple location is determined periodically and recorded. The maximum temperature reading since the beginning of a campaign of the furnace is also determined and recorded. From the current average and campaign ._.
maximum temperature readings from the thermocouple signals, a determination is made on-line, i.e. during furnace operation, as to whether a protective solidified layer of metal skull exists on the inner face of the refractory and the thickness of the skull.
If no protective layer of solidified metal skull exists, or if it is of insufficient thickness, a determination is made as to whether a gap exists between the refractory and a metal shell of the furnace and the location of the gap or whether cooling of the metal shell is insufficient. Steps are then taken during furnace operation, based 'on the results of such calculations, to fill such gaps with refractory, to re-establish sufficient cooling of the shell or to form a protective solidified layer of sufficient thickness on the inner surface of the refractory. The method of this invention also includes performing a moving boundary calculation directly from measured temperatures at all thermocouple locations in a vertical plane simultaneously to discern irregular erosion profiles, e.g. "elephant-shaped" and "bowl-shaped" erosion of the refractory.
H_rief Description of the Drav~incts Figure 1 is a cross-section of one-half of a blast furnace hearth showing the arrangement of thermocouples in the refractory and metal shell of the hearth area of the furnace.
Figure 2 is a scrematic side elevation view of the tap hole area of a blast furnace illustrating the placement of thermocouples in that area.
Figure 3 is a flow diagram of steps taken in accordance with the method of this invention.
Disclosure of the Invention This invention relates to a method for extending the life of refractory lining the interior of a metal shell of a blast furnace. The method includes placing thermocouples in the refractory at a plurality of spaced locations and monitoring the signals produced by the thermocouples during furnace operation. An average of the temperature readings at each thermocouple location is determined periodically and recorded. The maximum temperature reading since the beginning of a campaign of the furnace is also determined and recorded. From the current average and campaign ._.
maximum temperature readings from the thermocouple signals, a determination is made on-line, i.e. during furnace operation, as to whether a protective solidified layer of metal skull exists on the inner face of the refractory and the thickness of the skull.
If no protective layer of solidified metal skull exists, or if it is of insufficient thickness, a determination is made as to whether a gap exists between the refractory and a metal shell of the furnace and the location of the gap or whether cooling of the metal shell is insufficient. Steps are then taken during furnace operation, based 'on the results of such calculations, to fill such gaps with refractory, to re-establish sufficient cooling of the shell or to form a protective solidified layer of sufficient thickness on the inner surface of the refractory. The method of this invention also includes performing a moving boundary calculation directly from measured temperatures at all thermocouple locations in a vertical plane simultaneously to discern irregular erosion profiles, e.g. "elephant-shaped" and "bowl-shaped" erosion of the refractory.
H_rief Description of the Drav~incts Figure 1 is a cross-section of one-half of a blast furnace hearth showing the arrangement of thermocouples in the refractory and metal shell of the hearth area of the furnace.
Figure 2 is a scrematic side elevation view of the tap hole area of a blast furnace illustrating the placement of thermocouples in that area.
Figure 3 is a flow diagram of steps taken in accordance with the method of this invention.
Figure 4 is graphic representation of blast furnace hearth refractory lining wear and solidified metal skull formation determined according to the method of this invention.
Figure 5 is a schematic representation of two refractory-metal shell interface temperatures, TIR and TIS, determined by two different analyses, with TIR
substantially greater than TIS, indicating the presence of a gap between the refractory and metal shell.
Figure 6 is a schematic representation of the two refractory-metal shell interface temperatures, TIR
and TIS, with TIS substantially greater than TIR, indicating insufficient cooling of the metal shell.
Modes for Carrvina Out the Invention Referring to Figure 1, thermoprobes for measuring temperature, preferably thermocouples, are embedded in the refractory and the metal shell of a blast furnace in the hearth area. Thermocouples 10 and 12 are placed in the refractory sidewall of the hearth at two known positions across the thickness in a radial direction of the furnace. At least one thermocouple la is embedded at a known position in the metal shell in line with thermocouples 10 and 12 in the refractory.
This first group of thermocouples is preferably placed at the elevation of a tap hole of the furnace and in the vicinity of the tap hole. A second group of thermocouples 16, 18 and 20 is placed at substantially vertically aligned positions with the first group at an elevation above the top surface 21 of the hearth pad.
A third group of thermocouples 22, 24 and 26 is placed at substantially vertically aligned positions with respect to the first two groups at an elevation in the SUBSTITUTE SHEET (RULE 26) corner of the hearth sidewall where the sidewall meets Che hearth pad. Thermocouple groups are placed in the floor of the hearth i.e. in the hearth pad, at two knoam elevations with their hoC junctions vertically aligned.
One pair of thermocouples 28 and 30 is placed in the centerline of the furnace. A second pair of thermocouples 32 and 34 is placed one-third of the way to the inside of the metal shell at the hearth sidewall. A third pair, 36 and 38 is placed two-thirds of the distance to that location. It is preferred that thermocouples in this arrangement be placed at spaced locations around the periphery of the furnace, with Chermocouple coverage concentrated in the areas of the potentially highest wear such as around the tap hole.
Referring to Figure 2, the placement of thermocouples around the tap hole area of the furnace is illustrated more specifically. Two groups of thermocouples 40 and 42 are located on either side of the tap hole at about the tap hole elevation. These 2o thermocouples may be in-line in a horizontal direction normal to the plane of the drawing or spaced about four inches (10 cm) from each other in the vertical direction as shown in Figure 2. At an intermediate elevation above the top surface of the hearth pad, five groups of thermocouples 44, 45, 48, 50 and 52 are located in the tap hole area. Another five groups of thermocouples 54, 56, 58, 60 and 62 are located at about the elevation of the corner of the sidewall and the Cop surface of the hearth pad. The thermocouples in the latter two groups may be spaced about two feet (0.6096 meters) apart in a horizontal direction in the plane of Figure 2.
As shown in Figure 3, the readings taken from the plurality of thermocouples embedded in the WO 99!17106 PCTIUS98/19582 refractory and shell are used as input in a computer program to carry out a sequence of heat transfer calculations. The current average and campaign maximum temperatures from these thermocouples are fed into a heat transfer model that translates these inputs into a heat flux. From this information, a one-dimensional heat transfer model calculates the location of the hot metal solidification isotherm, for example 2100°F for blast furnace iron. The solidification isotherm which results from this calculation is used as the initial boundary in a two-dimensional heat transfer model. The two-dimensional heat transfer program iterates until a final boundary of the solidification isotherm is determined by minimizing the difference between the measured and predicted temperatures at each measuring point. The two-dimensional heat transfer calculations are made on the basis of the following two equations:
i CaxJ +~ ar~ dxdr aJ _ o aT
where T is the temperature at the location where the radius~co-ordinate from the centerline of the furnace is r, and the height co-ordinate is x. By using the average and the maximum temperatures, the sequence of heat transfer calculation provides two solidification isotherm interfaces, Ih and Ic, respectively, as shown in Figure 4. The interface Ih is closer to the hot side as compared with Ic. The isotherm interface Ic, which is closer to the cold side represents the wear profile of the refractory lining, SUBSTITUTE SHEET (RULE 26) ',,l- _.
while Ih represents the skull formation between hot metal and the lining. The distanee between Ih and Ic represents the thickness of the solidified skull. The presence of the skull prevents the lining from the direct attack by hot metal and enables extending the life of the blast furnace hearth. The beginning of an irregular erosion profile in the corner is illustrated in Figure 4, where an "elephant-shaped"
erosion is beginning to form as indicated by a greater ' erosion 62 in the corner than the erosion 64 in the adjacent sidewall. The method of this invention is able to determine "elephant-shaped" irregular erosion in an on-line calculation using a moving boundary calculation which considers the relationships between measured temperatures at all locations in a vertical plane simultaneously.
' The campaign maximum thermocouple readings represent the ultimate erosion profile of the refractory brick. Generally, the campaign maximum readings correspond to the highest heat flux and minimum calculated refractory thickness. These readings are then applicable to determine the critical isotherm corresponding to the actual erosion profile of the brick, Ic.
The average thermocouple readings represent the current condition within the hearth. The last hour's average temperatures recorded at each location is used to determine the current position of the critical isotherm and to calculate TIR and TIS, for purposes described hereinbelow, at all locations in the furnace hearth. The position of the current critical isotherm, Ih, relative to the isotherm corresponding to the maximum calculated refractory erosion profile, Ic, relates the presence and relative thickness of the protective skull on the inside surface of the refractory at each location. In general, when the current average thermocouple readings approach the campaign maximum temperatures, Ic -. Ih, this indicates that there is presently no protective skull layer on the inside surface of the brick.
After calculating the critical isotherms, at each location, calculated values of TIR and TIS are used to determine the presence of a gap between the shell and the hearth brickwork and the presence of a build-up on the furnace shell.
TIR = Ti - (Lr Li )kW T - Ti k,( T) L= - L, TIS=T,+ (Ls-L,)k,(T) T,-T=
k,( T) L= - L~
Where TIR - Calculated shell interface temperature as calculated from hot side TIS - Calculated shell interface temperature as calculated from water cooled side T1 - Measured temperature from location 1, see Figures 5 and 6 TZ - Measured temperature from location 2, see Figures 5 and 6 Ts = Measured shell temperature Li = Relative position of shell interface as referenced from the coordinate system SUBSTITUTE SHEET (RULE 26) Ll - Relative position of thermocouple 1 as referenced from coordinate system Lz - Relative position of thermocouple 2 as referenced from the coordinate system s - Relative position of shell thermocouple as referenced from the coordinate system kl(T) - Thermal conductivity as a function of temperature between locations 1 and 2 ki(T) - Thermal conductivity between shell l0 interface and location 2 k,(T) - Thermal conductivity of the shell Given these calculated values, the program then uses logical comparison statements to indicate 15 potential warning conditions and directs appropriate action to alleviate any problems indicated.
As shown in Figure 5, TIR and TIS are calculated and then compared to determine if a gap has 20 formed. TIR is calculated according to the formula above from temperatures T1 and T2 at thermocouple locations 1 and 2 in Figure 5 (which correspond, for example, to thermocouples 10 and 12 in Figure 1). TIS
is calculated using the formula above from temperatures 25 Ts, T1 and T2 temperatures (where Ts corresponds to thermocouple 14 in Figure 1). The following relation is used for that comparison:
If (TIR - TIS) > Preset limit (50°F in one 30 case), then a gap has formed between the refractory an3 the metal shell. The preset limit typically may be selected from within a range of from 20 to 120°F.
Corrective action may be taken to fill the gap e.g.
SUBSTITUTE SHEET (RULE 26) with a high conductivity grout material to re-establish contact with the cooled shell.
As shown in Figure 6, TIR and TIS are calculated and then compared to determine if a build-up on the shell has occurred. The following relation is used for that comparison:
If (TIS - TIR) > Preset limit (50 F in one l0 case), then the water cooling on the shell is insufficient. Again the preset limit typically may be selected from within a range of from 20 to 120°F.
Action may be taken to check for a problem in the water system or to determine if a potential build-up has formed on the outside surface of the shell which is interfering with proper heat transfer. After determining the cause of the problem, action may be taken to remove the build-up or to re-establish proper water flow in this area to improve heat removal efficiency. Conventional measures may be taken to correct these problems, for example, the shell surface may be sand blasted to remove any build-up or other measures may be taken to correct insufficient water flow or high temperature water.
Where there is no gap formed between the refractory and the shell and where cooling of the shell is sufficient and yet there is no solidified metal skull formed on the refractory lining of the furnace, or the thickness of the skull is insufficient to serve as protection for the refractory, measures may be taken to form a solidified metal skull of sufficient thickness to serve as protection for the refractory or to form additional refractory on the surface of the lining. Such measures may take the form of injecting SUBSTITUTE SHEET (RULE 26) or charging titanium-bearing materials into the furnace to protect the inner surface of the hearth, or reducing production and adjusting tuyere velocity to form a solidified metal skull of sufficient thickness.
Industrial A~plicabilitv The invention is applicable to blast furnaces for producing iron for the steel industry as well as in blast furnaces for producing non-ferrous metals.
SUBSTITUTE SHEET (RULE 26)
Figure 5 is a schematic representation of two refractory-metal shell interface temperatures, TIR and TIS, determined by two different analyses, with TIR
substantially greater than TIS, indicating the presence of a gap between the refractory and metal shell.
Figure 6 is a schematic representation of the two refractory-metal shell interface temperatures, TIR
and TIS, with TIS substantially greater than TIR, indicating insufficient cooling of the metal shell.
Modes for Carrvina Out the Invention Referring to Figure 1, thermoprobes for measuring temperature, preferably thermocouples, are embedded in the refractory and the metal shell of a blast furnace in the hearth area. Thermocouples 10 and 12 are placed in the refractory sidewall of the hearth at two known positions across the thickness in a radial direction of the furnace. At least one thermocouple la is embedded at a known position in the metal shell in line with thermocouples 10 and 12 in the refractory.
This first group of thermocouples is preferably placed at the elevation of a tap hole of the furnace and in the vicinity of the tap hole. A second group of thermocouples 16, 18 and 20 is placed at substantially vertically aligned positions with the first group at an elevation above the top surface 21 of the hearth pad.
A third group of thermocouples 22, 24 and 26 is placed at substantially vertically aligned positions with respect to the first two groups at an elevation in the SUBSTITUTE SHEET (RULE 26) corner of the hearth sidewall where the sidewall meets Che hearth pad. Thermocouple groups are placed in the floor of the hearth i.e. in the hearth pad, at two knoam elevations with their hoC junctions vertically aligned.
One pair of thermocouples 28 and 30 is placed in the centerline of the furnace. A second pair of thermocouples 32 and 34 is placed one-third of the way to the inside of the metal shell at the hearth sidewall. A third pair, 36 and 38 is placed two-thirds of the distance to that location. It is preferred that thermocouples in this arrangement be placed at spaced locations around the periphery of the furnace, with Chermocouple coverage concentrated in the areas of the potentially highest wear such as around the tap hole.
Referring to Figure 2, the placement of thermocouples around the tap hole area of the furnace is illustrated more specifically. Two groups of thermocouples 40 and 42 are located on either side of the tap hole at about the tap hole elevation. These 2o thermocouples may be in-line in a horizontal direction normal to the plane of the drawing or spaced about four inches (10 cm) from each other in the vertical direction as shown in Figure 2. At an intermediate elevation above the top surface of the hearth pad, five groups of thermocouples 44, 45, 48, 50 and 52 are located in the tap hole area. Another five groups of thermocouples 54, 56, 58, 60 and 62 are located at about the elevation of the corner of the sidewall and the Cop surface of the hearth pad. The thermocouples in the latter two groups may be spaced about two feet (0.6096 meters) apart in a horizontal direction in the plane of Figure 2.
As shown in Figure 3, the readings taken from the plurality of thermocouples embedded in the WO 99!17106 PCTIUS98/19582 refractory and shell are used as input in a computer program to carry out a sequence of heat transfer calculations. The current average and campaign maximum temperatures from these thermocouples are fed into a heat transfer model that translates these inputs into a heat flux. From this information, a one-dimensional heat transfer model calculates the location of the hot metal solidification isotherm, for example 2100°F for blast furnace iron. The solidification isotherm which results from this calculation is used as the initial boundary in a two-dimensional heat transfer model. The two-dimensional heat transfer program iterates until a final boundary of the solidification isotherm is determined by minimizing the difference between the measured and predicted temperatures at each measuring point. The two-dimensional heat transfer calculations are made on the basis of the following two equations:
i CaxJ +~ ar~ dxdr aJ _ o aT
where T is the temperature at the location where the radius~co-ordinate from the centerline of the furnace is r, and the height co-ordinate is x. By using the average and the maximum temperatures, the sequence of heat transfer calculation provides two solidification isotherm interfaces, Ih and Ic, respectively, as shown in Figure 4. The interface Ih is closer to the hot side as compared with Ic. The isotherm interface Ic, which is closer to the cold side represents the wear profile of the refractory lining, SUBSTITUTE SHEET (RULE 26) ',,l- _.
while Ih represents the skull formation between hot metal and the lining. The distanee between Ih and Ic represents the thickness of the solidified skull. The presence of the skull prevents the lining from the direct attack by hot metal and enables extending the life of the blast furnace hearth. The beginning of an irregular erosion profile in the corner is illustrated in Figure 4, where an "elephant-shaped"
erosion is beginning to form as indicated by a greater ' erosion 62 in the corner than the erosion 64 in the adjacent sidewall. The method of this invention is able to determine "elephant-shaped" irregular erosion in an on-line calculation using a moving boundary calculation which considers the relationships between measured temperatures at all locations in a vertical plane simultaneously.
' The campaign maximum thermocouple readings represent the ultimate erosion profile of the refractory brick. Generally, the campaign maximum readings correspond to the highest heat flux and minimum calculated refractory thickness. These readings are then applicable to determine the critical isotherm corresponding to the actual erosion profile of the brick, Ic.
The average thermocouple readings represent the current condition within the hearth. The last hour's average temperatures recorded at each location is used to determine the current position of the critical isotherm and to calculate TIR and TIS, for purposes described hereinbelow, at all locations in the furnace hearth. The position of the current critical isotherm, Ih, relative to the isotherm corresponding to the maximum calculated refractory erosion profile, Ic, relates the presence and relative thickness of the protective skull on the inside surface of the refractory at each location. In general, when the current average thermocouple readings approach the campaign maximum temperatures, Ic -. Ih, this indicates that there is presently no protective skull layer on the inside surface of the brick.
After calculating the critical isotherms, at each location, calculated values of TIR and TIS are used to determine the presence of a gap between the shell and the hearth brickwork and the presence of a build-up on the furnace shell.
TIR = Ti - (Lr Li )kW T - Ti k,( T) L= - L, TIS=T,+ (Ls-L,)k,(T) T,-T=
k,( T) L= - L~
Where TIR - Calculated shell interface temperature as calculated from hot side TIS - Calculated shell interface temperature as calculated from water cooled side T1 - Measured temperature from location 1, see Figures 5 and 6 TZ - Measured temperature from location 2, see Figures 5 and 6 Ts = Measured shell temperature Li = Relative position of shell interface as referenced from the coordinate system SUBSTITUTE SHEET (RULE 26) Ll - Relative position of thermocouple 1 as referenced from coordinate system Lz - Relative position of thermocouple 2 as referenced from the coordinate system s - Relative position of shell thermocouple as referenced from the coordinate system kl(T) - Thermal conductivity as a function of temperature between locations 1 and 2 ki(T) - Thermal conductivity between shell l0 interface and location 2 k,(T) - Thermal conductivity of the shell Given these calculated values, the program then uses logical comparison statements to indicate 15 potential warning conditions and directs appropriate action to alleviate any problems indicated.
As shown in Figure 5, TIR and TIS are calculated and then compared to determine if a gap has 20 formed. TIR is calculated according to the formula above from temperatures T1 and T2 at thermocouple locations 1 and 2 in Figure 5 (which correspond, for example, to thermocouples 10 and 12 in Figure 1). TIS
is calculated using the formula above from temperatures 25 Ts, T1 and T2 temperatures (where Ts corresponds to thermocouple 14 in Figure 1). The following relation is used for that comparison:
If (TIR - TIS) > Preset limit (50°F in one 30 case), then a gap has formed between the refractory an3 the metal shell. The preset limit typically may be selected from within a range of from 20 to 120°F.
Corrective action may be taken to fill the gap e.g.
SUBSTITUTE SHEET (RULE 26) with a high conductivity grout material to re-establish contact with the cooled shell.
As shown in Figure 6, TIR and TIS are calculated and then compared to determine if a build-up on the shell has occurred. The following relation is used for that comparison:
If (TIS - TIR) > Preset limit (50 F in one l0 case), then the water cooling on the shell is insufficient. Again the preset limit typically may be selected from within a range of from 20 to 120°F.
Action may be taken to check for a problem in the water system or to determine if a potential build-up has formed on the outside surface of the shell which is interfering with proper heat transfer. After determining the cause of the problem, action may be taken to remove the build-up or to re-establish proper water flow in this area to improve heat removal efficiency. Conventional measures may be taken to correct these problems, for example, the shell surface may be sand blasted to remove any build-up or other measures may be taken to correct insufficient water flow or high temperature water.
Where there is no gap formed between the refractory and the shell and where cooling of the shell is sufficient and yet there is no solidified metal skull formed on the refractory lining of the furnace, or the thickness of the skull is insufficient to serve as protection for the refractory, measures may be taken to form a solidified metal skull of sufficient thickness to serve as protection for the refractory or to form additional refractory on the surface of the lining. Such measures may take the form of injecting SUBSTITUTE SHEET (RULE 26) or charging titanium-bearing materials into the furnace to protect the inner surface of the hearth, or reducing production and adjusting tuyere velocity to form a solidified metal skull of sufficient thickness.
Industrial A~plicabilitv The invention is applicable to blast furnaces for producing iron for the steel industry as well as in blast furnaces for producing non-ferrous metals.
SUBSTITUTE SHEET (RULE 26)
Claims (10)
1. A method of monitoring the wear of a refractory lining of a blast furnace wherein the refractory lining has temperature probes embedded therein, comprising the steps of:
a. measuring temperatures at different points across the thickness of the refractory lining by the temperature probes embedded therein;
b. estimating the location of a solidification isotherm of the hot metal in said furnace using a one dimensional heat transfer approximation;
c. using the one dimensional heat transfer approximation as the initial boundary to begin a moving boundary calculation from a two dimensional heat transfer model; and d. continuing to iterate the two dimensional heat transfer model until a final boundary of said solidification isotherm is determined by minimizing the difference between the measured temperature and a temperature predicted by said two dimensional heat transfer model at each temperature measuring point; said final boundary of the solidification isotherm indicating the position of a wear surface of the refractory lining for purposes of monitoring the wear thereof.
a. measuring temperatures at different points across the thickness of the refractory lining by the temperature probes embedded therein;
b. estimating the location of a solidification isotherm of the hot metal in said furnace using a one dimensional heat transfer approximation;
c. using the one dimensional heat transfer approximation as the initial boundary to begin a moving boundary calculation from a two dimensional heat transfer model; and d. continuing to iterate the two dimensional heat transfer model until a final boundary of said solidification isotherm is determined by minimizing the difference between the measured temperature and a temperature predicted by said two dimensional heat transfer model at each temperature measuring point; said final boundary of the solidification isotherm indicating the position of a wear surface of the refractory lining for purposes of monitoring the wear thereof.
2. A method of determining the thickness of a protective layer of solidified metal skull formed on the refractory hearth of a blast furnace wherein the refractory hearth has temperature probes embedded at spaced locations in radial directions from the center of the furnace and at various elevations across the thickness of the floor and walls thereof, comprising the steps of:
a. periodically measuring temperatures at said spaced locations in said radial directions and across the thickness of the furnace hearth floor and walls by the temperature probes embedded therein;
b. determining the maximum temperature recorded by each temperature probe since the beginning of a campaign of the furnace and the average temperature recorded by each temperature probe during a current time period;
c. analyzing the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth walls correlated with the radial distance between the temperature probes and the center of the furnace and the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth floor correlated with the elevation distance between the location of the temperature probes in the hearth floor so as to predict the location of the wear line of the refractory hearth from the location of a solidification isotherm closest to a metal shell, and to predict the location of the inner surface of a solidified metal skull lining said refractory hearth from an isotherm closest to the hot side of the furnace remote from the metal shell, and d. determining the thickness of the protective layer of solidified metal skull from the distance between the predicted wear line of the refractory hearth and the predicted inner surface of the metal skull.
a. periodically measuring temperatures at said spaced locations in said radial directions and across the thickness of the furnace hearth floor and walls by the temperature probes embedded therein;
b. determining the maximum temperature recorded by each temperature probe since the beginning of a campaign of the furnace and the average temperature recorded by each temperature probe during a current time period;
c. analyzing the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth walls correlated with the radial distance between the temperature probes and the center of the furnace and the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth floor correlated with the elevation distance between the location of the temperature probes in the hearth floor so as to predict the location of the wear line of the refractory hearth from the location of a solidification isotherm closest to a metal shell, and to predict the location of the inner surface of a solidified metal skull lining said refractory hearth from an isotherm closest to the hot side of the furnace remote from the metal shell, and d. determining the thickness of the protective layer of solidified metal skull from the distance between the predicted wear line of the refractory hearth and the predicted inner surface of the metal skull.
3. A method according to claim 2 wherein said analysis is carried out by estimating the location of said solidification isotherms using a one dimensional heat transfer approximation, using this approximation as the initial boundary to begin a moving boundary calculation from a two dimensional heat transfer model, and continuing to iterate the two dimensional heat transfer model until a final boundary of each solidification isotherm is determined by minimizing the difference between the measured temperature at each temperature probe location and a predicted temperature at said location based on iterations of the two dimensional heat transfer model.
4. A method of determining the conditions of heat transfer between a refractory lining and a water cooled metal shell of a blast furnace wherein at least one group of temperature probes are embedded at spaced locations in a radial direction of the furnace, said group of temperature probes including at least two temperature probes located in the refractory lining and at least one temperature probe in the water cooled metal shell of the furnace, comprising the steps of:
a. from the temperature difference between temperature probes of said group aligned in a radial direction in the refractory lining, determining the temperature at the interface between the refractory lining and the metal shell, said interface temperature being designated TIR;
b. from the summation of the temperature of the temperature probe embedded in the metal shell and the temperature difference between temperature probes aligned in a radial direction in the refractory lining, determining a second temperature at said interface, said interface temperature being designated TIS; and c. comparing the values of TIR and TIS to determine the difference there between.
a. from the temperature difference between temperature probes of said group aligned in a radial direction in the refractory lining, determining the temperature at the interface between the refractory lining and the metal shell, said interface temperature being designated TIR;
b. from the summation of the temperature of the temperature probe embedded in the metal shell and the temperature difference between temperature probes aligned in a radial direction in the refractory lining, determining a second temperature at said interface, said interface temperature being designated TIS; and c. comparing the values of TIR and TIS to determine the difference there between.
5. A method according to claim 4 wherein a determination is made that a gap exists between the refractory lining and said metal shell when the temperature TIR is substantially greater than the temperature TIS.
6. A method according to claim 4 wherein a determination is made that cooling of the metal shell is insufficient when the temperature TIS is substantially greater than the temperature TIR.
7. A method of extending the life of a refractory lining of a blast furnace hearth, wherein the refractory lining of said hearth has temperature probes embedded at spaced locations in radial directions from the center of the furnace hearth and at various elevations across the thickness of the floor and walls of the furnace hearth, comprising the steps of:
a. periodically measuring temperatures at said spaced locations in said radial directions and across the thickness of the refractory lining of the hearth by the temperature probes embedded therein;
b. determining the maximum temperature recorded by each temperature probe since the beginning of a campaign of the furnace and the average temperature recorded by each temperature probe during a current time period;
c. analyzing the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth walls correlated with the radial distance between the temperature probes and the center of the furnace hearth and the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth floor correlated with the elevation distance between the temperature probes and the floor so as to predict the location of the wear line of the refractory lining from the location of a solidification isotherm closest to a metal shell, and to predict the location of the inner surface of a protective layer of solidified metal skull lining said refractory hearth from an isotherm closest to the hot side of the furnace remote from the metal shell, d. determining the thickness of the solidified metal skull during actual furnace operation from the distance between the wear line of the refractory lining and the inner surface of the metal skull, and e. maintaining sufficient thickness of said protective layer of solidified metal skull during operation of said furnace to extend the life of the refractory lining of said furnace hearth.
a. periodically measuring temperatures at said spaced locations in said radial directions and across the thickness of the refractory lining of the hearth by the temperature probes embedded therein;
b. determining the maximum temperature recorded by each temperature probe since the beginning of a campaign of the furnace and the average temperature recorded by each temperature probe during a current time period;
c. analyzing the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth walls correlated with the radial distance between the temperature probes and the center of the furnace hearth and the relation of said campaign maximum and current average temperatures of said temperature probes embedded in the hearth floor correlated with the elevation distance between the temperature probes and the floor so as to predict the location of the wear line of the refractory lining from the location of a solidification isotherm closest to a metal shell, and to predict the location of the inner surface of a protective layer of solidified metal skull lining said refractory hearth from an isotherm closest to the hot side of the furnace remote from the metal shell, d. determining the thickness of the solidified metal skull during actual furnace operation from the distance between the wear line of the refractory lining and the inner surface of the metal skull, and e. maintaining sufficient thickness of said protective layer of solidified metal skull during operation of said furnace to extend the life of the refractory lining of said furnace hearth.
8. A method according to claim 7 wherein said analysis is carried out by estimating the location of said solidification isotherms using a one dimensional heat transfer approximation, using this approximation as the initial boundary to begin a moving boundary calculation from a two dimensional heat transfer model, and continuing to iterate the two dimensional heat transfer model until a final boundary of each solidification isotherm is determined by minimizing the difference between the measured temperature at each temperature probe location and a predicted temperature at said location based on iterations of the two dimensional heat transfer model.
9. A method according to claim 7 further comprising temperature probes embedded in a water cooled metal shell of the furnace hearth aligned at the same elevation with the temperature probes in the furnace hearth walls, and wherein said step of maintaining a protective layer includes the step of maintaining adequate heat transfer from the refractory hearth walls to the metal shell of the furnace hearth and from the metal shell to cooling water applied to the metal shell; said step of maintaining adequate heat transfer including determining a first temperature at the interface between the refractory lining of the hearth and the metal shell from the temperature difference between at least two temperature probes aligned in a radial direction in the refractory hearth walls, said first interface temperature being designated TIR; determining a second temperature at said interface from the summation of the temperature of at least one of the temperature probes embedded in the metal shell and the temperature difference between said temperature probes aligned in the same radial direction as the temperature probe in said shell, said second interface temperature being designated TIS; comparing the values of TIR and TIS to determine the difference there between; and in the event of a substantial difference between TIR and TIS taking corrective action to minimize the difference .
10. A method for making on-line determinations of irregular erosion profiles of a refractory lining of a blast furnace wherein the refractory lining has temperature probes embedded therein, comprising the steps of:
a. measuring temperatures at different points across the thickness of the refractory lining at a plurality of elevations by the temperature probes embedded in the lining;
b. initially estimating the location of a solidification isotherm of the hot metal in the furnace;
and c. from the initial estimated isotherm location making a moving boundary calculation to determine the final boundary by minimizing the difference between the measured temperature and a temperature predicted by said moving boundary calculation at all temperature probe locations in a vertical plane simultaneously, in order to make on-line determinations of irregular erosion profiles of said refractory lining.
a. measuring temperatures at different points across the thickness of the refractory lining at a plurality of elevations by the temperature probes embedded in the lining;
b. initially estimating the location of a solidification isotherm of the hot metal in the furnace;
and c. from the initial estimated isotherm location making a moving boundary calculation to determine the final boundary by minimizing the difference between the measured temperature and a temperature predicted by said moving boundary calculation at all temperature probe locations in a vertical plane simultaneously, in order to make on-line determinations of irregular erosion profiles of said refractory lining.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/938,760 US5890805A (en) | 1997-09-26 | 1997-09-26 | Method for monitoring the wear and extending the life of blast furnace refractory lining |
| US08/938,760 | 1997-09-26 | ||
| PCT/US1998/019582 WO1999017106A1 (en) | 1997-09-26 | 1998-09-17 | Method for monitoring the wear and extending the life of blast furnace refractory lining |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2296516A1 CA2296516A1 (en) | 1999-04-08 |
| CA2296516C true CA2296516C (en) | 2004-02-17 |
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ID=25471917
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002296516A Expired - Fee Related CA2296516C (en) | 1997-09-26 | 1998-09-17 | Method for monitoring the wear and extending the life of blast furnace refractory lining |
Country Status (4)
| Country | Link |
|---|---|
| US (4) | US5890805A (en) |
| BR (1) | BR9811772A (en) |
| CA (1) | CA2296516C (en) |
| WO (1) | WO1999017106A1 (en) |
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| JP3938584B2 (en) * | 2005-04-08 | 2007-06-27 | 株式会社神戸製鋼所 | Blast treatment container remaining life prediction device, remaining life prediction method, and blast treatment facility |
| US6375346B1 (en) | 2000-02-07 | 2002-04-23 | Usx Corporation | Method for detecting the spalling of a layer of buildup of a refractory lining in a metallurgical furnace |
| US7174787B2 (en) * | 2003-03-13 | 2007-02-13 | Andec Manufacturing Ltd. | System and method for inspecting an industrial furnace or the like |
| PL1893972T3 (en) * | 2005-02-22 | 2017-10-31 | Hatch Ltd | Systems, methods and apparatus for non-disruptive and non-destructive inspection of metallurgical furnaces and similar vessels |
| US20060186585A1 (en) * | 2005-02-22 | 2006-08-24 | Afshin Sadri | Systems, methods and apparatus for non-disruptive and non-destructive inspection of metallurgical furnaces and similar vessels |
| EP1777505A1 (en) * | 2005-10-19 | 2007-04-25 | Siemens Aktiengesellschaft | Virtual temperature measuring point |
| EP1835279A3 (en) * | 2006-03-13 | 2011-07-13 | Betriebsforschungsinstitut VDEh Institut für angewandte Forschung GmbH | Method and measuring device for identifying the thermal conductivity of the fireproof material of an oven lining |
| EP2198229B1 (en) * | 2007-09-28 | 2014-06-18 | Hatch LTD. | Method for the acoustic monitoring of tapblocks and similar elements |
| WO2014030118A2 (en) * | 2012-08-20 | 2014-02-27 | Larsen & Toubro Limited | A method and a system for determination of refractory wear profile in a blast furnace |
| CN102965461A (en) * | 2012-12-24 | 2013-03-13 | 营口戴斯玛克科技发展有限公司 | Device for diagnosing blast-furnace hearth lining |
| US10935320B2 (en) | 2013-04-12 | 2021-03-02 | Refractory Intellectual Property Gmbh & Co. Kg | Method for determining the state of a refractory lining of a metallurgical vessel for molten metal in particular |
| CN105219905B (en) * | 2015-11-09 | 2017-04-26 | 马鞍山钢铁股份有限公司 | Device for monitoring upward hearth temperature change of blast furnace and application of device |
| US10444079B2 (en) * | 2016-10-13 | 2019-10-15 | Tata Consultancy Services Limited | System and method for accretion detection |
| US10018363B1 (en) * | 2016-12-23 | 2018-07-10 | Jade Range LLC | Hearth oven |
| US10604814B2 (en) | 2017-09-27 | 2020-03-31 | International Business Machines Coporation | Manufacturing process control with deep learning-based predictive model for hot metal temperature of blast furnace |
| CN110387450A (en) * | 2018-07-17 | 2019-10-29 | 柳州钢铁股份有限公司 | The device and method that blast furnace crucible corrosion is monitored |
| CA3114682C (en) * | 2018-10-22 | 2023-05-16 | Arcelormittal | Method for monitoring the wear of a refractory lining of a blast furnace |
| CN110938453B (en) * | 2019-12-16 | 2021-04-02 | 中冶南方工程技术有限公司 | Temperature control method for iron coke production shaft furnace for blast furnace |
| CN111854668B (en) * | 2020-08-25 | 2024-07-12 | 中冶赛迪工程技术股份有限公司 | Blast furnace lining thickness calculating device and method based on distributed optical fiber temperature measurement |
| CN112146774A (en) * | 2020-09-24 | 2020-12-29 | 广东电科院能源技术有限责任公司 | Method and system for measuring temperature of hearth in waste incineration power plant |
| CN113176295B (en) * | 2021-05-29 | 2024-04-09 | 郑州大学 | Method for testing optimal service temperature and thermal fatigue life of heat-insulating refractory material |
| CN114350889B (en) * | 2021-12-29 | 2023-08-08 | 金川集团股份有限公司 | Furnace lining thickness monitoring method and furnace lining thickness monitoring system for converter |
| CN114395651A (en) * | 2022-02-28 | 2022-04-26 | 中冶赛迪工程技术股份有限公司 | Intelligent management method and system for furnace hearth |
| WO2024063754A1 (en) * | 2022-09-19 | 2024-03-28 | Paneratech, Inc. | System and method for determining the thickness of a material in manufacturing vessels |
| CN116608802A (en) * | 2023-07-17 | 2023-08-18 | 中国空气动力研究与发展中心计算空气动力研究所 | Method, device, equipment and medium for synchronously measuring temperature and thickness during thickness variation |
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| GB1119110A (en) * | 1965-11-26 | 1968-07-10 | Gen Electric | Improvements in switch and terminal assembly for selectively controlling dynamoelectric machine winding circuits and the like |
| CA969776A (en) * | 1972-03-06 | 1975-06-24 | Jacques Antoine | Device for measuring the temperature in a furnace |
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-
1997
- 1997-09-26 US US08/938,760 patent/US5890805A/en not_active Expired - Lifetime
-
1998
- 1998-09-17 BR BR9811772-6A patent/BR9811772A/en not_active IP Right Cessation
- 1998-09-17 WO PCT/US1998/019582 patent/WO1999017106A1/en active Application Filing
- 1998-09-17 CA CA002296516A patent/CA2296516C/en not_active Expired - Fee Related
- 1998-12-24 US US09/220,899 patent/US5944421A/en not_active Expired - Fee Related
- 1998-12-24 US US09/220,708 patent/US5975754A/en not_active Expired - Fee Related
- 1998-12-24 US US09/002,208 patent/US5961214A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2296516A1 (en) | 1999-04-08 |
| BR9811772A (en) | 2000-08-29 |
| US5975754A (en) | 1999-11-02 |
| US5890805A (en) | 1999-04-06 |
| US5944421A (en) | 1999-08-31 |
| WO1999017106A1 (en) | 1999-04-08 |
| US5961214A (en) | 1999-10-05 |
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