SU89866A1 - Gas span of the heads of open-hearth furnaces - Google Patents

Description

The invention relates to gas flow devices of the heads of open-hearth furnaces with a short caisson in the frontal part and a ramming reinforced lining in the rest.

Devices of gas spans with a long water-cooled caisson, lined with refractory bricks from the inside, are known. They have a number of disadvantages, of which the main ones are: the difficulty of making bulky metal caissons; high water consumption for their cooling and significant heat loss with water cooling and, as a result, a decrease in the efficiency of fuel use, especially significant in small capacity furnaces of the order of 10-20 tons.

The proposed device does not have these disadvantages.

FIG. I shows a gas span in longitudinal section along line A-A in FIG. 2; in fig. 2 is a cross-section along line BB in FIG. I, without refractory masonry; in fig. 3 shows a view of transverse reinforcement bars; in fig. 4-hem bands.

The gas span is performed with a short water-cooled caisson in the frontal (with respect to the direction of flow of the combustion products) part of the span and with an internal printed, reinforced metal mesh and carcass, chromo-magnesite lining in the rest of the span. The packed part of the span is arranged in the following manner r.

On a solid wooden formwork I lay an iron grid 2, curved in the form of formwork. Grid install transverse formwork curved iron strips 3 having radial slots 4. Longitudinal strips 5 having the same slots that fit into the slots of transverse strips 3 respectively are placed in said slots 4, which ensures the rigidity of the framework. Lanes 3 and 5 in separate places are welded to each other and to the iron grid 2. The metal structure from the grid is assembled in this way and

No. 89866

strips with cells of the order of 120 x 120 mm are reinforcement for gas-filled gasket lining. After assembling, the reinforcement cell is filled with a mass of 6 from ground chromite and magnesite mixed on the dewatered resin.

The mass is compacted with heated metal rammers. The mass consists of 75% magnesite powder by volume with a grain size up to 20 mm, from 5% ground chromic ore with a grain size up to 4 mm and from 10% dehydrated resin. The dry components of the mass are placed on an iron sheet heated from below, mixed by shoveling, and poured with a continuous resin while stirring. The mass is considered ready for use when the resin ceases to roll and is distributed evenly throughout the volume of the mass.

Alternatively, the composition of the mass for testing recommends a mass with the addition of iron shavings in an amount of 5-10% ((10 th volume).

The padded part of the span can be made both outside the furnace and in a place in the furnace. When running outside the oven, before installing it into the oven, the stuffed part is dried.

Short water-cooled frontal caisson 7 is installed in place after checking the installation of the stuffed part of the span. The caisson and the stuffed part of the span are firmly joined by a weld along the perimeter of the end of the caisson and the end transverse strip 4 of the stuffed part.

On the stuffed part of the span, one edge of one row of chrome-magnesite brick 8 is laid flush with the outer side surface of the caisson, and along this first row and along the outer side surface of the caisson, the second row of the same brick 9. Over the wall of chromo-magnesite brick, the well-printed chromite leshad air span.

The first row of chrome-magnesite brick is laid with iron spacers with a thickness of more than 1 mm.

Subject invention

The gas span of the heads of open-hearth furnaces, characterized in that, in order to reduce heat losses and increase the durability of the gas span, it is performed with a short water cooled caisson in the frontal part relative to the direction of flow of the combustion products and with an internal rammed reinforced metal mesh and chrome-magnesite frame lined in the rest of the.

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