DE588772C - Water-cooled discharge mines for pusher ovens - Google Patents

Description

Water-cooled ejector mines for pusher furnaces The modern rolling mill operation requires very high performance from the pusher furnaces necessary for heating the rolled material, which in turn require numerous special structural measures to be taken on the furnace itself.

This also includes. those introduced in a wide variety of training courses water-cooled discharge chutes.

These are generally heavy, channel-shaped, water-cooled, Cast-iron beams, which are level with the extension door of the pusher in the hearth floor of the pusher oven are built in. In this way, a resistant base is created, on which the removal or ejection of the hot goods can take place, foreseeing that essential Damage to the shock source can occur. Also form at this point no growths or depressions due to slagging of the hearth base.

While with these channels in narrow ovens through, .veg good 1? Experiences In the case of wide ovens, it was caused in numerous cases by throwing and warping the beam as well as cracking and leakage of the cooling tubes cast into the beam often to operational disruptions.

The causes of numerous failures are in the uneven Seek warming of the gutter.

For a better understanding of this, especially in the case of broad, heavy Malfunctions occurring in the rolling stock working furnace are indicated on the accompanying drawing referenced.

Fig. I shows a cross-section through the furnace at the level of the shock hearth with built-in discharge chute.

Fig. Z gives a cross-section through .the gutter again, from which it can be seen; how the gutter is embedded in the fire-resistant building material of the stove.

Since the refractory building material is a poor conductor of heat and the Cooling of the internal beam with a strong internal cross-section, uneven heating does not occur can occur when the stove is heated up as a result of the direct flame effect on the top of the beam a, b compressive stresses, as a result of which the beam becomes convex Seeks to bend the arch upwards.

Such tensions arise if the furnace is suddenly switched off in the underside of the beam, as the upper furnace chamber cools down faster than the Hearth, so that the beam experiences an opposite deflection. Since this is changing Bending forces working towards tearing the cooling tubes occur next to the Malfunctions resulting from the throwing of the bars, still often malfunctions by leaking the cooling tubes.

The channel design shown in Fig. 3 according to the present one The invention does not allow the thermal stresses described above to arise at all. As can be seen from the drawing, the new channel consists of numerous individual parts e, which have a small distance from each other and only through the cast Cooling pipes are connected to each other.

1) a thereby the surface tensions occurring in the short pieces, in relation to the entire channel, can never express itself as tensile or compressive stresses, the defects associated with the known channels do not occur.

To avoid disruptions caused by the rolling stock getting stuck Ejected get the 'upper abutting edges of the pieces e opposite to the abutment direction a bevel that prevents the rolling stock from getting stuck during ejection with certainty prevented.

Claims (1)

PATENT CLAIMS: i. Water-cooled discharge chute for pusher ovens, thereby characterized in that they are made up of several closely spaced apart, cast individual parts (e), their connection only through the cast thick-walled cooling tubes is given. z. Water-cooled gully according to claim i, characterized in that the upper abutting edges of the individual pieces are opposite are beveled to the direction of ejection of the rolling stock.