Blast Furnace Stoves Research Articles

Overhaul of blast-furnace stoves

Overhaul of blast-furnace stoves

Increasing the reliability of measurement of the temperature of blast-furnace stove domes

Increasing the reliability of measurement of the temperature of blast-furnace stove domes

4492568 Process and apparatus for preheating the combustion mediums used for firing blast furnace stoves

4492568 Process and apparatus for preheating the combustion mediums used for firing blast furnace stoves

Thermomechanical properties of mullite-corundum refractories based on fused mullite

A study was made of the strength and deformation behavior of mullite-corundum refractories with various concentrations of fused mullite. Analysis of the range of properties, taking into account the demands placed on refractories for service in different components of the structure of high temperature blast furnace stoves, suggests that articles based on compositions Nos. 2–4 may be used in the lower parts of the combustion chambers, since they possess outstanding deformation properties; and articles based on compositions Nos. 1, 2, and 4 may be used in the hot blast connecting pipes and gas burners, where it is also necessary to provide a high thermal-shock resistance in the refractory.

Evaluation of Checker Bricks for Blast Furnace Stoves

Currently, the stoves of blast furnaces are operated at a higher temperature for increasing productivity. Consequently, the demand on the quality of checker bricks has increased. In TISCO, the blast furnaces are operated at a hot blast temperature of 900°C. An attempt has been made to evaluate the refractories available from indigenous sources. Various physical and chemical properties of the bricks have been analysed along with their mineralogical constituents. Compressive creep characteristics have also been evaluated.

Mechanization of stripping and lining operations in reconstructing blast-furnace stoves

Mechanization of stripping and lining operations in reconstructing blast-furnace stoves

Evaluation of coating systems for the internal protection of blast furnace stoves

Stress corrosion cracking at the weld areas in the interior of blast furnace stoves has become a world wide problem which has been accentuated by the higher operating temperatures and pressures now used. This paper describes the work carried out to evaluate various protective coatings proposed for application to the interior of the stove shell plates to prevent the stress corrosion. A heat and chemical resistant polyurethane primer‐pitch polyurethane top coat has given superior results to all coatings tested, particularly when applied over a hot sprayed ceramic.

Investigation of thermal operating conditions of shielded prechecker spaces in blast-furnace stoves

Investigation of thermal operating conditions of shielded prechecker spaces in blast-furnace stoves

Character of fracture of the shell metal of blast-furnace stoves

Character of fracture of the shell metal of blast-furnace stoves

Thermally insulating blast-furnace stoves with fibrous materials

Thermally insulating blast-furnace stoves with fibrous materials

Feedforward control of blast furnace stoves

This paper is concerned with the control of a system of blast furnace stoves when subject to changes in load and operated according to the ‘by-pass main’ principle. A limiting condition for stable cyclic equilibrium at maximum thermal efficiency is first developed for any given combination of the two load variables, blast temperature and flowrate, assuming, in the first part of the paper, zero changeover time. The condition may be used to predict whether a given load change will lead, for constant hot gas flow rate, to the establishment of a new cyclic equilibrium state or to an instability condition called ‘collapse’ by Zuidema. The gain of a feedforward compensator which manipulates hot gas flow rate may also be evaluated so that a wider range of load changes may be satisfied without collapse. Non-zero changeover time markedly reduces the maximum thermal efficiency attainable from a given stove installation and is predicted to lead to the existence of two possible states of cyclic equilibrium for a given hot gas flow rate. The most efficient operating state may be selected by combined feedforward/feedback control over average hot gas flow rate. A new method of digital simulation for regenerator systems is described which uses standard engineering simulation packages and which has a number of advantages when simulating transient stove operation.

Improving the performance of blast-furnace stoves

Improving the performance of blast-furnace stoves

Technology and production of dinas from Pervourals quartzites for blast furnace stoves

Using Pervourals quartzites a technology was developed for blast-furnace stove dinas, and an industrial batch was prepared for determining the properties of the products.

Wear of refractories in blast furnace stoves

The wear and slagging of the checkers in the stoves are due to the formation of fusible compounds under the action of iron oxides, alkalis, and other oxides brought into the unit with the charging and agglomeration dust and the dust from the blast furnace gas, which in the final account led to premature stoppage of the stove for repairs.

Service of nonpowderable dinas in high-temperature stoves of blast furnaces

Experience with the use of low-powdered (low embrittlement) dinas in the high-temperature zones (walls, cupolas, combustion chamber, and checkers) of blast furnace stoves showed that at subcupola temperatures of 1350–1450°C after 3 years service the original physicochemical properties of the product were not impaired, and the structure had preserved its satisfactory condition. A study of the properties of low-powdered dinas after service showed that despite the reduction in the density as a result of additional transition in the quartz, the structure of the dinas is not embrittled, but is densified. Considering the relatively good deformation properties of the low-embrittlement dinas, its use should be tested in the operation of stoves with subcupola temperatures of 1500–1550°C.

Study of the service of high-alumina and kaolin refractories in the checkers and structure of blast-furnace stoves

The structure of kaolin brick in the high-temperature zone of the stove after 6.7–7.2 years service at subcupola temperatures of 1300°C underwent substantive external and structural changes.

Non-stationary operation of a staggered parallel system of blast furnace stoves

A theoretical study is made of the optimal operation of staggered parallel blast furnace stoves under non-stationary conditions, caused by load changes. Two different types of load changes are considered. The first type consists of those changes that can be accommodated by the stove system at once. For this type of load changes the problem is studied how to return the system as quickly as possible to stationary operating conditions after step changes in the load. The second type of load changes consists of changes that are too large to be accommodated at once. Here a two-stage operation is envisaged: In the first stage the heat content of the stoves is built up to the point where the demanded load can be accommodated, and in the second stage the system is returned to stationary operating conditions. Numerical results are given for a particular stove system.

Refractory Problems Associated with High Temperature Blast Furnace Stoves

Eiffciency and productivity of Blast Furnace depends on the performance of Hot Blast Stoves. Recent trend is to operate the Blast Furnaces with a hot blast temperature of 1000°C and above. Various modifications are necessary in the design and the quality of refractories used in the stoves to obtain the hot blast temperature in that range. Problem is more aggravated when changing the existing stoves to high temperature operation which is designed originally for low temperature operation. Various refractory problems associated with the changing over to high temperature operation of stoves that are faced in Tisco have been discussed.

Fibrous insulating refractories for blast furnace stoves

A technology was developed for producing heat insulating fibrous materials based on kaolin wool and Chasov Yar clay for blast furnace stoves.

Temperature rise in the walls and crown of blast furnace stoves

During the heating of blast furnace stoves the structure shows an expansion. The actual magnitude of the thermal expansion of the refractory structure in the stoves relative to its housing across the height and radius is less than the calculated value. The discrepancy between the calculated and experimental data in terms of thermal expansion of these structures requires the carrying out of wider experiments.