SU1330170A1 - Gas duct of metallurgical furnace - Google Patents

Abstract

The invention relates to ferrous metallurgy, and more specifically to the structures of smoke exhaust ducts of metallurgical furnaces, in particular double-welded steel-smelting units. The purpose of the invention is to increase the efficiency of removal and cooling of the exhaust gases from the furnace. The pipes 3 of the cooled flue panels 1 are wave-shaped in the direction of the flue gases. The axial line of each of them lies in the plane perpendicular to the adjacent wall of the gas duct, it forms a sinusoid of the form of 0.532 / CDsinajx, where X is the coordinate in the direction of the gas flow; y is the coordinate perpendicular to the direction of movement of the gas stream. w angular frequency. The wave crests of two adjacent tubes shift relative to each other. The planes in which the axial lines of the pipes are located, the opposite panels are shifted by half a step relative to each other. Due to the intensive cooling of gases along the path, the design of the flue duct allows to improve the conditions of gas withdrawal from the furnace working space, and to intensify the thermal operation of the furnace, increase its productivity by 0.5-0.8% and steam production by 5-6 thousand Gcal / year, 3 Il. sl with 00 with

Description

eleven

The invention relates to ferrous metallurgy, in particular to the design of a chimney. cich tracts metallurgical furnaces. B particular twin-steel furnaces,

The cell of the invention is designed to reduce the waste and cooling efficiency of waste P1 from the furnace gases. .

Figure 1 shows the vertical section 1 of the creep of a two-bath steel-smelting furnace, a longitudinal section; on .fig. 2 - section A-L in FIG. 1, in FIG. 3, the geometrical parameters of the pipe axial line.

A two-stage steel-smelting furnace is a shielded vertical flue 1 containing a casing 2 of refractory bricks whose inner surface is made of cooling pipes 3 combined in a panel with inlet 4 and branch pipe-1 5 with branch pipes. The pipes 3 are wave-like in length, the center line of the pipes is described by the equation

0.532.

W; .J Sin W X,

where X is the coordinate in the direction of the gas flow

y is the coordinate perpendicular to the direction of the gas flow;

and - angular frequency. The pipes in the panel are installed in such a way that the crest of one wave is opposite to the depression on the next one. The pitch between the pipe axes is chosen to be, for example, 2.5 of their diameter. Pipe axes of opposite sides are shifted by half a step.

The gases leaving the working space with a temperature of 1200–1600 ° C enter the vertical gas duct 1. Upon contact with the developed cold surface of the panels, an intensive heat removal from the flue gases occurs, which leads to a decrease in their physical volume, thereby improving their evacuation condition.

The pipes in the panels are wave-like along the length of the flue and having a sinusoidal shape allows a significant increase in the contact surface; r; h with double-bore gases (approximately 1.5-, 0 times) with minimum hydraulic i.) I .P1; h; ti (by movement in the pipes of the pipe 1 and the steam-water emulsion, and i-ifcopi-f.-j of the axial line of the pipe described by the angle

0.532.

yi-sinwx.

eliminates the overgrowth of melting dust between adjacent wave ridges by melting dust. The latter is due to the fact that in the proposed design of the flue duct, the most prominent place for deposition of smelting dust is the area on the pipe, where the depression passes into the protrusion.

The equation of the sinusoid, the x axis of which passes through the inflection point on this platform, and the y axis coincides with the direction of the protrusions and troughs of the wave, with the initial phase of the wave in general form

A sin O) X, where A is the amplitude

co-frequency

The angle between the tangent at the point of inflection on the pipe axis is determined from the expression

t tg o (AOJCOSUJX

When X 0 (or X n-2l) we have

tg 0 Aw, whence A

, tgo

and;

Proceeding from the conditions that the angle should be no more than the angle of repose of dust, i.e. 28 °

A - 2r532,

W

where the value 0.532 is the tangent of angle 28.

The sinusoid equation, which describes the center line of the pipe and allows you to choose its optimal shape, has

view

 Di532

with

sinwx

The displacement of the crests of the waves of two adjacent pipes in a pan.phi for half a period, as well as the displacement of the planes in which the axial lines of the pipes of the opposite sides of the duct are located by half a step, ensures the lowest possible hydraulic resistance to the movement of flue gases in the duct, since possible section of the flue when installing the cooled panels in it.

The choice of pitch between the planes in which the axial lines of adjacent pipes are located, is caused by the influence of this parameter on the heat removal, since it is largely determined by this parameter (determines

angular emissivity). With a pitch of less than two pipe diameters, a decrease in heat loss is observed due to the influence of adjacent pipes. At a pitch between the axes of pipes equal to more than 2.5 diameters, the effect on the tagshog is eliminated (5menu of the relative position of adjacent pipes, therefore, a further increase in this parameter is impractical.

Based on these considerations, the pitch between the pipe axes in the panel is assumed to be 2.0-2.5 pipe diameters.

I

The proposed design of the flue due to the intensive cooling of gases along the path allows to improve the conditions for removal of gas from the working space, to intensify the thermal operation of the furnace, to increase its productivity. It will also increase steam production by evaporative cooling.

The use of a gas flue of the proposed design, for example, in a steel-smelting twin-boiled unit allows an increase in productivity by 0.5-0.8%, and the production of additional steam by 5-6 thousand Gcal / year.

Claims (1)

Invention Formula A metallurgical furnace furnace duct containing a casing, on the inner surface of which tubular cooled panels are located, characterized in that, in order to improve the efficiency of removal and cooling of the gases flowing from the furnace, the tubes of the cooled panels are made wavy in the direction of flue gases, at this axial line each of them lies in the plane, the perpedical circular adjacent wall of the duct, and forms a sinusoid of the form 0 five Where x 0.532. ui X, U) 0 coordinate in the direction of flow ra3OBot o; y is the coordinate perpendicular to the direction of movement of the gas flow; y is the angular frequency, moreover, the wave crests of two adjacent pipes in the cooled panel are shifted by half a period relative to each other, and the planes in which the axial lines of the pipes of the opposite panels are located are shifted by half a step relative to each other. . (pual (fJu & .Z  fi.Z Editor N.Kishtulinets Compiled by L. Sharapova Tehred L. Serdyukova 3541/27 Circulation 549 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Corrector. In. Girn to Subscription