US1970186A - Melting furnace - Google Patents

Description

H, PONTZEN MELTING FURNACE Aug. 14, 1934.

Filed July 27. 1932 3 Sheets-Sheet l Aug. 14, 1934. H. PoNTzEN 1,970,186

MELTING FURNACE Filed July 27. 1932 3 Sheet's-Sheet 2 Rigid E *U d i vPatented iig. 14, 1934 UNITED STATES PATENT OFFICE IVIELTING FURNACE Application July 27, 1932, Serial No. 625,106 In Germany August 4, 1931 3 Claims.

It has already frequently been proposed to make use of the waste gases produced in smelting metals in reverberatory furnaces for pre-heating the new charge. For example two rotary furg; naces have been arranged side by side to serve alternately for smelting and pre-heating while leading thegases in alternating directions. Thus the smelting process was carried out in an intermittent manner.

The present invention relates to a tiltable reverberatory furnace in which several interconnected chambers are arranged perpendicularly around the tilting axle which in case two chambers are used, are connected at their lower ends to form a U. The essential advantage of this arrangement is that the utilization of the waste heat is achieved to a much higher extent because the flames are forced to pass through the material. This causes a diminution of the velocity of the fire gases and an increase of the transmission of the heat.

The pressure of the column of metal in the pre-heating chamber acts automatically upon the material and presses it downwards enabling a continuous charging of fresh material. Thus it is possible to work continuously and to smelt in one chamber and to pre-heat in the other for a long period. For this purpose the vertical position of the smelting chamber is of essential importance. The smelting zone is situated rather far away from the burner, in cthe connecting channel between the two chambers, and is hereby not exposed to the highest flame temperature, so that the loss by combustion is minimized. Only the liquid metal covered with slag reaches the zone of the burner and may be hereby heated, too, without danger of loss.

This over-heated material may then with the swinging movements of the furnace, transmit its im heat to the new charge. The invention is shown on the accompanying drawings, in which Figure 1 is a vertical section of the apparatus.

Figure 2 shows a section on the line A-B of Figure 1.

45 Figure 3 shows a section of the furnace in horizontal position tilted to right.

Figure 4 shows the same tilted to left. Figure 5 shows another embodiment of the apparatus in vertical section 'taken on the line 5o 5-5 of Figure 6.

Figure 6 is a horizontal section taken on the line 6-6 of Figure 5.

Figure 'I shows still another embodiment of the apparatus in vertical section taken on the line 55 TI-'l oi Figure 8.

(Cl. 26S-33) Figure 8 is a-horizontal section taken on the line 8-8 of Figure '7.

In the drawings, (a) represents the refractory wall of the furnace, (b) and (c) two smelting chambers connected in the lower part.

(d) represents the separating furnace wall which forces the burner gases to pass through the whole smelting chamber. The length of this separating wall (d) can be adapted according to requirements. The whole body of the furnace is rotatable by means of pivots (e) and the tilting arrangement (f) generally up to 90 in each direction, so that besides the vertical position shown in Figure l, the positions of Figures 3 and 4 can also be assumed. The two chambers are open at the outer end so that the burner (g) which is movable can be placed in front of either; if the burner is made to act through the chamber (b), the waste gases are withdrawn from the chamber (c) and vice versa. h1, h2, and ha are tap holes through which the liquid metal can be withdrawn from diiferent levels of the furnace as required.

The furnace makes it possible to collect the smelting charge in the sump of the connecting channel with a vertical position and in the lower chamber with a horizontal position of the furnace.

If desired, cooling of the bath of metal by contact with the material to be pre-heated in the upper chamber or over-heating of the melted metal may be effected.

If the furnace is turned into a Vertical position by means of the tilting arrangement, on the bottom of the U shaped compartment a bath is formed which comes into contact with the cold charge but which nevertheless leaves so much of the cross-section open that the fire gases can reach the pre-heating chamber between the separating wall and the surface of the bath. If the furnace is tilted still further the molten metal runs into the pre-heating zone, comes into contact with the pre-heated charge lying here and causes it to melt quickly. This operation can be carried out continuously until the melting chamber is empty. The method of carrying out this process may be illustrated by the following examplei-The furnace is heated up in a vertical position while simultaneously charging the metal to be smelted. If desired the furnace may then be' turned upon an angle of 90 according to Figure 3 and a certain quantity of the charge added. As soon as part of the metal on the hearth now lying in a horizontal position is molten, the iurnace may again be brought into a vertical position, whereby the charge accumulates in the lower part of the furnace. The charging of the pre-heating chamber is continued. By agitating movements of the furnace the molten bath is repeatedly mingled with the metal column in the pre-heating chamber. Without tilting the furnace any further one may discharge liquid metal continuously through the lower tap hole. In order to improve the heat exchange, it is advisable to tilt the furnace occasionally so that the bath runs over the heated hearth of the chamber provided with the burner, thereby absorbing the heat accumulated in the walls. This heat may be transferred to the lower sump by turning the furnace and used to facilitate the melting of the fresh charge in the pre-heating chamber.

The tilting of the furnace to a horizontal position comes also into question if for certain purposes, for example, when smelting cast-iron, it is intended to over-heat the charge. In this case the material is discharged through the tap-hole h1.

If for some time the heating has been carried out through chamber (b) as smelting chamber, the whole process is effected in an opposite direction so that chamber (c) is now used for smelting and chamber (b) for charging fresh material and for pre-heating the same. In this way the life of the lining is materially increased since the whole brick-work is uniformly worn out. The connecting channel (i) between the two chambers may, if desired, be used to withdraw part of the flue gases by the suction of the burner into the chamber just being heated and to increase the effect of heating. In this Way the relatively high oxygen content of the waste gases is utilized. This oxygen content is particularly advantageous for the combustion because the sensible heat of the waste gases is simultaneously re-utilized in part. The heat economy may be improved by constructing the pivots (e) and the separating wall in such a way that they act as air recuperators. In this way, on the one hand the air required for combustion is heated up and on the other hand, the part of the furnace which is most exposed to wear, is cooled.

While the form of apparatus herein described constitutes a preferred form of the invention, it is to be understood that the invention is not limited to this precise form of apparatus and that changes may be made without departing from the scope of the invention; for instance, it is not necessary to use only two chambers in the whole construction should it be advantageous for certain purposes, i. e. for the addition of further alloying components or purifying materials etc. to use two or more pre-heating chambers in addition. Such constructions are shown in Figures 5-8 inclusive. The furnace shown in Figures 5 and 6 consists of two pairs of chambers b1 and b2, each pair of chambers being separated by the wall di but all four chambers connect with one another at the bottom. The furnace shown in Figures 7 and 8 consists of three chambers c2, cz and bz, the two chambers cz being separated from each other by the wall dz and all three chambers connecting with one another at the bottom. The furnace may serve as a smelting furnace for all metals and besides this, as a converter for blowing metals or as a refining furnace. It may also be advantageously used for alloying different metals, since over-heating of the molten material is avoided by the contact of the charge to be preheated with the metal bath. Especially if metals are to be alloyed, such as copper with its high melting point and zinc with its low melting point, one may first introduce the zinc, melt it and then add the copper and alloy the two components in a rapid and simple way by tilting the furnace.

I claim:

1. A reverberatory furnace mounted so as to be tiltable through an angle of 90 on each side of the vertical, said furnace consisting of at least two substantially parallel normally vertical shafts, the axes of which lie in a plane which is perpendicular to the pivotal axis of the furnace, said shafts being interconnected at their lower ends and of substantially the same length and cross-section, and means for introducing heating gases into said shafts at their upper ends one at a time.

2. A reverberatory furnace mounted so as to be tiltable through an angle of 90 on each side of the vertical, said fuinace consisting of two substantially parallel normally vertical shafts, the axes of which lie in a plane which is perpendicular to the pivotal axis of the furnace, said shafts being interconnected at their lower ends and of substantially the same length and crosssection, and means for introducing heating gases into said shafts at their upper ends one at a time.

3. A reverberatory furnace mounted so as to be tiltable through an angle of 90 on each side of the vertical, said furnace consisting of two substantially parallel normally vertical shafts of substantially the same length and cross-section, said shafts being separated from each other by a wall, but interconnected at their lower ends so as to permit practically unobstructed passage of material from one shaft into the other, a passage in the upper portion of the separating wall communicating with the upper portions of the two shafts, the axes of the shafts lying in a plane which is at right-angles to the pivotal axis of the furnace and a burner movably arranged at the upper end of the furnace so as to permit introduction of heating gases into said shafts one at a time.

HERBERT PONTZEN.

Images