US2013486A - Rotary furnace - Google Patents

Description

Sept. 3, 1935. cs. 'BRUNKOW 2,013,435

ROTARY FURNACE Filed Jan. 27, 1954 s Sheets-Sheet 1 Fig.1

Sept. 3, 1935. G. BRUNKOW ROTARY FURNAC E Filed Jan. 27, 1934 3 Sheets-Sheet 2 a: x E I N v a.

N '6 ,2; on gm 0 p 1935' G. BRUNKOW 2,013,486

RO TARY FURNACE Filed Jan. 27, 1934 3 Sheets-Sheet 5 Fig.4

Patented Sept. 3, 1935 UNITED: STATES norsnr rumvscr:

Gerhard Brunkow, Magdeburg-Buckau,

assignor to firm Fri Germany,

ed. Krupp Grusonwerk Aktlengesellschait, Magd'eburg-Buckau, Germany Application January 27, 1934, Serial No. 108.645 In Germany February 14, 1933 The present invention relates to rotary'fur naces having a number of muilles for carrying out endothermic/processes, etc. In such furnaces it is known" to locate, parallel to the axis of rotation. muflles for carrying out endothermic processes of all'kinds, particularly for the distillation of metals, as zinc or cadmium, so that the charge in the muiiles is) during the rotation of the entire furnace system, constantly heated by being brought into contact with the heated muiile wall. This construction has the disadvantage that the muiiles areheated wholly or preponderantly only from one end of the furnace, so that at the end of the muflle that is remote from. the latter there exist temperatures that are considerably less than at the other end of the muiiie, which is within the range of the heating flame. The-main object of the invention is to produce as uniform a heating as possible of the muflles practically over their entire length.

According to the invention there is employed/ for the carrying out of such processes as the above amuiiie system in which the several muflies, which maybe formed of a generally cylindrical shape or approximately so, are supported by discs arranged at right angles to the muilies and in their turnccnnected together centrally by means of a shaft, which is advantageously insulated. The entire muiile system or shaft supporting discs and muiiles then rotates within a fixed furnace chamber. whilst the heating maybe effected-by means .of several burners which are arranged transversely to thedirection of rotation so that the heating may be very well regulated.

By way of illustration, various furnaces in accordance with the invention are represented diagrammatically in the accompanying drawings, wherein- Figure Us a longitudinal section of a furnace having a muille system, I

Figure 2 is a; section on the line A-B of Figure v Figure 3 represents in longitudinal section a, construction of furnace in which a condenser is rigidly connected with the mume system and Figures 4 and 5 are longitudinal sections of other constructions of furnace having condensers.

In all the figures of the drawings i represents the supporting shaft, which is formed by way of example as an air-cooled tube. 'and is mounted in bearings I and provided with an external insulating sleeve 3. On the tube i there are arranged supporting discs 4 and 5 which. are provided with linings 4' and I and receive the several muilles 6. For further supporting the muiiies, in the con- -8 Claims. (Cl. 266--18) structions shown in Figures 1 to 4, there are provided metallic supporting discs I, to which the. munles, in as far as they are metallic, may be attached possibly by welding. The mufile system is rotated, according to Figures 1 to 4, within a fixed furnace structure 8. According to Figure 5, instead of a metallic supporting ring 1, there is provided a supporting ring 9 built of bricks, so

'that two separate furnace chambers l0 and l I are produced for the heating of the muilles. "This division of the furnace block has for-its object to render accessible to the external air the metal ring I! necessary for supporting the ring 9, so as to prevent the latter from being over-heated. Referring more particularly to Figure 2, at It there is provided a burner the flame of which. after passing through an ante-chamber It, enters the furnace chamber 8 at l5. It is advisable to rotate the muflle system in the direction of the arrow :2: so that the surfaces of the charges in the several muflies are approximately parallel and inclined in the direction indicated at ll. The hot gases in passing through the furnace chamber It to the flue opening I8 therefore strike all the nuiilles preferably at the part at which they are covered by the material contained in them. In order that it may be possible to regulate the quantity of the gases that pass through over the supporting tube or under the supporting tube it is advisable to provide further flue openings ID. The regulation of the gas path may be effected according to circumstances by widening or narrowing the flue opening by means of the normally walled-up openings 20. When, in the case of carrying out the endothermic process it is a question of operations in which the access of air is to be prevented, it may be advisable to close the muflie at both ends by means of removable caps 2 I, the charging and emptying of the mumes bein effected by removing the caps.

When, in the endothermic process, gaseous products of the reaction occur and these are to be condensed immediately as-for example in the case of the distillation of zinc, it is advisable to arrange the necessary condenser also in the rotary portion of the furnace. This may be eftested, as shown in Figure 3, by connecting the supporting tube l rigidly with a condenser 22, the mounting of the system then advantageously being effected in such a manner that the tube itself is supported only at one end and the condenser is supported at theother end at 23. The driving of the entire system is effected by a pinion 26. In the construction shown in Figure 3 the feeding of the charge takes place from. a bunker 25 through branches 28 by means of a worm 26 and an annular conduit 21. When the bunker 25 is sufficiently full a good air-tight closure is ensured by the charge itself. In the case of this mode of feeding the caps 29 serve merely for the observation and cleaning of the muffles. Each individual mufile is connected by branches 30 with an annular conduit 3| into which the solid products of the reaction are discharged and in which, if required for the purpose of an air-tight closure, there may be built a shut-off device. The gaseous products pass through a retention ring 32 into branches 33 and thence into the condenser 22. The uncondensed portions of the gas are led away at 34.

In the construction of the mufile furnace according to Figure 4, in which also a large collecting condenser is connected with the supporting tube, the muflies do not extend through the end walls of the rotary portion of the furnace,.

but are connected in a gas-tight manner with two annular chambers 35 and 35. This construction has the advantage that only one branch is necessary in each case for feeding and delivering the products. Feeding is effected again by means of a worm 26 and through a spiral tube 31, whilst delivery is made through a branch 38 into an external helical pipe 39, in which, if required for the cutting-off of the material, there may be built two closure devices. The gaseous products of the reaction pass into the condenser 22 through the branch 40.

In the case of the construction according to Figure 5 charging is effected intermittently by means of caps 4|, whilst delivery is again made into a helical tube 39 through branches 42. For condensing the gaseous products there is provided for each mufiie a separate condenser 43, which is connected at 44 with the supporting tube l and rotates therewith.

The above-described muffle system is suited particularly for the distillation of metals, for example, of zinc, cadmium or mercury, but other endothermic processes may also be carried out in this form of apparatus. When gaseous materials co-operate in the reaction and must be fed into the mufiies they may be introduced in a simple manner by means of the worm 26, which is then provided with a hollow shaft. The mufiles may be made of heat-resistant metal sheets or of ceramic materials, particularly silicon carbide or fireclay.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:-

1. In a furnace for carrying out endothermic processes, such as the distillation of zinc, cadmium and mercury; in combination, a. furnace chamber comprising walls having opposed circular openings; means for heating said furnace chamber; a rotatable unit within said chamber consisting of a central supporting element extending through said furnace chamber coaxial with said openings, a group of muilies surrounding said supporting element, and disks closing said circular openings, said disks having sealing faces fitting closely against corresponding faces in said circular openings; said central supporting element comprising a cylindrical insulating member in the part exposed to the heat of said furnace chamber, to prevent elongation and warping of said supportingelement which would impair the sealing effect of said sealing faces.

2. In a furnace for carrying out endothermic processes, such as the distillation of zinc, cadmium and mercury; in combination, a furnace chamber, a rotatable shaft extending through said chamber, an insulating casing on the portion of said shaft within said chamber, the unit consisting of said shaft and insulating casing being provided with a plurality of disks, a plurality of mufiies carried by said disksand grouped around said shaft, the walls of said furnace chamber having circular openings which are tightly closed by said disks, and means for heating said furnace.

3. A furnace as described in claim 1 in combination with one or two annular chambers into which the ends of said muflies open, said chambers serving as common transfer means for material passing through all said mufiies.

4. A fm'nace as described in claim 1, in combination with condenser means rigidly connected to said rotatable unit and conducting means between said muflles and condenser means for the passage of gases to be condensed.

5. A furnace as described in claim 1, in combination with individual condensers communicating respectively with said muflles.

6. A furnace as described in claim 1, wherein at least one intermediate supporting disc is provided to subdivide the furnace chamber.

GERHARD B RUNKOW.

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