SU1504255A1 - Method of drying and primary heating of blast-furnace air-heater lined with silica brick in high-temperature zone - Google Patents

Abstract

The invention relates to the field of heating to blow into a blast furnace in the ferrous metallurgy, in particular to the processes of drying and heating of blast furnace air heaters. The purpose of the invention is to increase the durability of the lining. To avoid premature destruction of the lining, drying and the first heating of the air heater lined in the high-temperature zone with a refractory refractory should be carried out according to the following schedule: the temperature rise of the inner surface of the dome lining from 20 to 100 ° C at a speed of 1.8-2.2 ° C / h, exposure at 100 ° С 82-86 h, rise from 100 to 300 ° С at a speed of 0.4-0.6 ° С / h, from 300 to 400 ° С at a speed of 1.4-1.6 ° С / h , from 400 to 700 ° С with a speed of 3.8-4.2 ° С / h, from 700 to 1300 ° С and higher with a speed of 6.8-7.2 ° С / h. The application of the invention increases the service life of the lining 2 times. 2 Il.

Description

The invention relates to heating blowing in a blast furnace in the ferrous metallurgy, in particular to the processes of drying and heating of blast furnace air heaters.

The purpose of the invention is to increase the durability of the lining.

FIG. 1 is a graph showing the drying and first warming up of the air heater; in fig. 2 - dependence of stresses in the refractory during drying and the first heating.

To avoid premature destruction of the lining, drying and the first heating of the air heater lined in the high-temperature zone with a refractory refractory should be carried out according to the following schedule: the temperature rise of the inner surface of the dome lining from 20 to 100 ° C at a speed of 1.8-2.2 ° C / h, holding at 100 ° C for 82-86 h, lifting from 100 to 300 ° C at a speed of 0.4-0, from 300 to 400 ° C at a speed of 1.4-1.6 ° C / h, from 400 up to 700 ° C at a speed of 3.5-4., 2 ° C / h, from 700 to 1300 ° C and higher at a speed of 6.8-7.2 ° C / h.

Heating with speeds above the upper limits of recommended permissible speeds is not permissible, since it leads to thermal destruction of the lining of the apparatus.

SP

N9 JV JV

3 15

Heating at speeds below the lower limits of the recommended allowable speeds is impractical from the point of view of increasing the duration of the process.

The method takes into account the modification transformations that occur in dynamics as well as thermal stresses that occur in a separate brick due to its uneven heating in length and brick as a structural element of the lining.

The method is illustrated by the following example.

Example. The first heating of the air heater lined in the high-temperature zone with a silica refractor is carried out according to the temperature of the inner surface of the cupboard lining according to the schedule: the temperature rises from 20 to 100 ° C at a rate of 2 ° C / h, and at 100 ° C for 84 hours.

temperature rise from 100 to 300 С

with a speed of 0.5 ° C / h, from 300 to 400 C 25 given temperature - with a speed

at a speed of 1.5 S / h, from 400 to

6.8-7.2 degrees / hour

700 С

at speeds from 700 to

and higher with speed. The use of the invention increases the service life of the air heater by about 2 times.

Claims (1)

Invention Formula 0 about five zone with a refractory lining, heating the lining to 100 ° C The method of drying and first warming up the air heater of a blast furnace lined in a high-temperature including at a speed of 1.8-2.2 degrees / hour, holding at this temperature for 84 hours, further heating it to a predetermined temperature, characterized in that, in order to increase the durability of the lining, it is heated from 100 to 0, 4-0.6 degrees / h, from 300 to - at a speed of 1.4-1.6 degrees / h, from 400 to 700 ° C - with a speed of 3.8-4.2 degrees / h, from 700 s to set tempera 6.8-7.2 degrees / hour 100 00 300 400 500 600 T hour fPat.l C. SO 300 300 500 600 T, ChiS Fi.1