SU1477745A1 - Arrangement for monitoring the wear of blast furnace lining - Google Patents

Abstract

This invention relates to a blast furnace and is intended to control the wear of a blast furnace lining. The aim of the invention is to improve the accuracy of monitoring the wear of the lining. The device consists of waveguides 1, mounted in the lining on different horizons along the height of the blast furnace. Thermocouples are placed along the waveguides in the upper and middle horizons, and pyrometers 11 are placed in the waveguides in the lower horizons. The essence of the invention is that the waveguides of the lower horizons are made of quartz, the middle ones are made of steel, while the upper ones are made of copper, and the thermocouples are made with the possibility of their longitudinal axial movement. Temperature measurement allows to take into account the effect of temperature on the speed of propagation of ultrasonic waves, and the implementation of waveguides from different materials takes into account the temperature regime of the blast furnace. 1CF files, 3 sludge.

Description

I

This invention relates to the field of blast furnace control.

The aim of the invention is to improve the accuracy of monitoring wear of the jacket.

FIG. 1 shows a diagram of the implementation of the device for controlling the wear of the lining; in fig. 2 shows section A-A in FIG. one; in fig. 3 — arrangement of thermocouples along the waveguides with the possibility of their longitudinal axial displacement, option.

The device for monitoring the wear of the lining contains waveguides 1 with a diameter of 0.010-0.040 m, mounted into the lining 2 at different levels along the height of the blast furnace. Outside the furnace, the waveguides are enclosed in an embrasure 3 with cooling fittings and gland seals. In the lower half of the mine, quartz waveguides are mounted, for example, on a furnace with a volume of 1033 m3, they are located on the three lower horizons; 1 / 10-1 / 20 of the height of the shaft below the protective plates of the furnace, for example, copper waveguides are placed on one upper horizon, and on average horizons, i.e. at a distance of 1 / 10-1 / 2 of the height of the shaft below the top of the protective plates of the furnace, - steel waveguides. 4-12 waveguides along the circumference of the mine are mounted on each horizontal - umbrella.

The arrangement of the four waveguides in the upper horizon is shown in FIG. 2. The increase in the number of waveguides on each horizon and the number of horizons contributes to an increase in the area of monitoring the wear of the lining of 2 blast furnaces and the delivery of more reliable information about the degree of wear at any point in time.

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50

five

In order to control the inner ends of the copper and steel waveguides, a through hole 4 is made inside each waveguide 1, which ends outside the furnace with pipe 5 with the packing device 6 and holes 7 for inert gas injection. A thermocouple is placed inside the guide tube 8 with a tip 9, which is connected to a secondary device 10, for example a potentiometer of the type PP-63.

The temperature of the inner ends of the quartz waveguides is controlled by a radiation pyrometer 11 connected to a secondary device (not shown).

Determining the thickness of the lining 2 according to the corrected speed of ultrasonic vibrations in waveguides 1 is carried out with an ultrasonic thickness gauge 12, for example, with an UT-92 P type device.

The process for monitoring liner wear is carried out in the following order. The waveguides 1 are mounted in the lining 2 after the completion of its temperature growth. To do this, 15-20 days after blowing, during the short-term stopping of the furnace, channels 2 are installed in the lining 2, the waveguides 1 are placed in them so that the inner ends of the waveguides 1 are flush with the working surface of the lining 2, and the outer ones are enclosed in the loophole 3 with gland seals and cooling.

Then, at any time, the temperature of the inner ends of the waveguides 1 is monitored. In this case, the pyrometer 11 of the radiation is used to control the quartz waveguides and the temperature control of the metal waveguides is performed in such a sequence

Through hole 4 in the waveguide rinsed with an inert gas, for example nitrogen, through the holes 7 in the nozzle 5 under a pressure of 230-300 kPa. Then, a hole 8 is inserted into the hole 7 until the contact of the tip 9 of the thermocouple with the charge materials is in contact. The thermocouple is kept in this working position for 5-10 minutes, after which device 10 records the temperature of the inner end of the waveguide.

The temperature control of the inner ends of the waveguides allows one to take into account the temperature error of measurements and to determine the residual thickness of the lining according to the corrected speed of ultrasonic vibrations in the waveguides. In this case, the corrected speed is determined by the following dependencies:

, 39-0,085-T-0.000034x

xT2 (20 ° С T 650 ° С); (1) Cst 5777 + 0.045-1-0,00042-T2 (20 ° (X

h

Ј T 900 ° C); (2)

CN 5724.379 + 0.131-T +0.000016 x x T2 (20 ° C T 1200 ° C), (3)

where CN, Cst, C is the speed of elastic oscillations, respectively, in copper, steel and quartz waveguides;

T is the temperature of the internal ends of these waveguides.

Then on the digital indicator of the thickness gauge 12 in the setting mode

oscillations increase the calculated value of the oscillation velocity, switch the thickness gauge 12 to the thickness measurement mode, place the transducer at the outer end of the waveguide 1 and, judging by the digital indicator, judge the thickness of the lining 2 at the installation site of the waveguide.

The device includes quartz waveguides, for example, made

with

Q 5

0 5

0

0

five

five

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five

Electro-fused quartz glass (content 99.99%), mounted in them not 1 / 2-3 / 4 of the height of the shaft. Quartz glass, along the light guide, provides the ability to control the temperature of the internal ends of the quartz waveguides using a radiation pyrometer. Moreover, this material retains elastic properties and the ability to conduct ultrasonic waves at temperatures up to 1200-1300 ° C, which necessitates its use as a waveguide in the lower part of the mine on those horizons where the temperature of peripheral gases varies between 900-1300 ° C i.e. at the bottom 1 / 2-3 / 4 of the height of the shaft.

On the middle horizons of the mine, i.e. at a distance of 1 / 10-1 / 2 of the height of the shaft below the top of the protective plates of the furnace, steel waveguides can be used due to their low cost compared to quartz ones and the ability to conduct ultrasonic waves at temperatures up to 900 ° C, i.e. the use of steel waveguides on medium horizons is more economically feasible than quartz ones.

Copper waveguides can be installed on the upper horizons, since on the horizons of the mine with a temperature of peripheral gases of 400-700 C (i.e. in the upper 1/10 of the height of the shaft) and an insufficiently intensive abrasive effect of the charge, the steel waveguides do not wear out simultaneously with the lining, which provides sufficient reliability of control.

The installation of copper waveguides below 1/10, and steel below 1/2 the height of the shaft from the top of the protective plates is impractical because, according to research, the speed of ultrasonic oscillations in copper and steel decreases with increasing temperature in accordance with equations 1 and 2 (for waveguide lengths 0.5-1.5 m and cooling of the outer ends), and these materials lose their elastic properties and the ability to conduct elastic wave oscillations when a certain temperature is reached (copper, 900QC — steel). The installation of waveguides in the upper 1/20 of the height of the shaft from the protective plates of the top is impractical, since the wear of the lining directly under the protective plates of the top (0.7-1.0 m below the plates) is insignificant and the control of this wear is impractical.

The measurement results indicate a fairly high accuracy of the proposed device.

Calculations show that the relative error does not exceed 0.005 m. The limit of the permissible absolute error of the thickness gauge is 0.01 of the measured thickness. Since the total length of the waveguide in the measurement process is 1E2-0.5 m, the error in measuring the thickness of the lining should be considered insignificant.

Monitoring the thickness of the refractory lining using the proposed device allows you to follow the dynamics of the working profile of the furnace when the technological parameters of the units change, prevent emergency shutdowns of furnaces due to the accelerated height of the refractories, purposefully use technological factors contributing to the increased service life of the refractory lining.

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Claims (1)

1. A device for monitoring the nose liner of a blast furnace, containing waveguides embedded in the liner, as well as the source and receiver of ultrasonic waves, characterized in that, in order to improve the accuracy of wear control of the liner, it is equipped with thermocouples and a pyrometer, connected to secondary devices, copper furnaces were installed in the upper horizons of the furnace shaft, steel ones in the middle, 15 and quartz waveguides in the lower horizons, and along the WOLNOROD there were placed termoromes on the upper and middle horizons, th axial 20 movements. 2 "Device according to claim. Characterized in that the copper waveguides are located at 1/10 - 1/20 hour  These are the heights of the shaft below the protective plates of the furnace top, the steel ones - at a distance of 1 / 10-1 / 2 parts of the height of the mine below the protective panels of the furnace top, and quartz ones in the lower 1 / 2-3 / 4 parts of the height 30 mines. CDtftl QiteJ