US2570572A - Cooling device and a method for transferring molten aluminum sulfate into solid pieces by using the device - Google Patents

Description

oer; 9, 1951 2,570,572 METHOD FOR TRANSFERRING MOLTEN AL UMINUM K. V. LENNSTRM COOLING DEVICE AND A SULFATE INTO SOLID PIECES BY USING THE DEVICE Filed Oct. 28, 1947 5 Sheets-Sheet l INVEN R.

N @2/ a v @ATTORNEY.

K. V. LENNSTRGM Oct. 9, 1951 METHOD FOR TRANSFERRING MOLTEN ALUMINUM SULFATE INTO SOLID PIECES BY USING THE DEVICE Filedoct. 28, 1947 COOLING DEVICE AND A 3 sheetseSheei 2 I II II JEE I EI -@HHHgwnwgi EMU E H H. E

INF/ENTER.

j lfg'rzgws W E I Oct. 9, 1951 K. v. LENNsTROM 2,570,572 COOLING DEVICE AND A METHOD FOR TRANSFERRING MOLTEN ALUMINUM SULFATE INTO SOLID PIECES BY USING THE DEVICE Filed Oct. 28, 1947 v 3 Sheets-Sheet 5 M 'INVfl TOR.

' ATTORNEY.

Patented Oct. 9, 1951 COOLING DEVICE AND A METHOD FOR TRANSFERRING MOLTEN ALUMINUM SULFATE INTO SOLID PIECES BY USING THE DEVICE Karl Valdemar Lennstriim, Halsingborg, Sweden, assignor to Reymersholms Gamla Industri Aktiebolag, Halsingborg, Sweden, a corporation of Sweden Application October 28, 1947-, Serial No. 782,630

In Sweden October 30, 1946 v 7 2 Claims.

. l V "The present invention relates to a new construction of a cool-ing device and a method for transforming molten aluminum sulphate into solid slabs or other pieces of handy size.

The cooling device according to the invention comprises an elongated trough with double walls and provided with inlet and outlet conduits for a cooling medium to the space between said walls,

bottom or by rounding the lower portion of said Wall's. Each end wall of the cooling trough'or box is preferably provided with a trunnion by means of whichthe box is mounted in suitable bearings so that it may be turned upside down when the content is to be discharged. These trunnions are arranged in such a way that their common axis is situated abov the centre of gravity of the emptied box and below the centre of gravity of the charged box. By arranging the mounting and tilting trunnions of the box in this way it is possible to tilt the. box and bring it back in it original position almost without using any energy for these operations. I

As mentioned above the invention also relates to a method for solidifying molten aluminum sulphate into pieces by using the device-described above. This method comprises the steps of charging the cooling box with aluminum sulphate molten in its crystal water and possibly remaining mother lye ata temperature of about 105- 115 C., cooling the charge or melt by means of circulating cooling medium until the melt is solidified as a coherent casting, and finally tilting the cooling box so that the solidified casting is tumbled out and-upon impact againsta suitablebed is broken up into pieces along the breaking sections caused by the bottom ridges of the cooling box.

In the following the invention is described more in detail, reference being had to the annexed drawings illustrating a preferred embodiment of the invention.

In the drawings:

- Fig. 1 is a longitudinal section of a cooling box according to the invention.

Fig. 2 is a section on the line IIII of Fig. 1.

Fig. 3 is a side view showing the cooling box mounted in a traverser.

Fig. 4 shows a plurality of cooling boxes mounted in traversers in connection witha storage room for making possible a full use of th storage room.

Fig. '5 shows an arrangement for stirring the solidifying material in the cooling box. I

In the drawings I refers to the cooling box, which is provided with double walls nd inlets and outlets 2 and 3 respectively for cooling fluid, preferably water. The inner bottom of the cooling box is provided with ridges 4 for producing the breaking sections in the casting solidified in the box. The inner side walls of the boxas well as the ridges A are made with draft to facilitate the loosening of the solidified product from the cooling box. In order to make the cooling more effective it is advantageous to insert guiding walls in the cooling jacket below the ridges for forc ing the cooling fluid through the space below the ridges as indicated with arrows 5 in Fig. 2.

The inlet and outlet conduits for the cooling fluid are preferably arranged in the trunnions by means of which the cooling box is suspended, for instance in a traverser. and on which the box is tiltabl'e. At least the outlet conduit for the cooling fluid is to be bent upwardly and terminate in an overflow outlet with the aim of securing the filling of the cooling jacket of the box with water and to avoid the risk of said chamber being emptied by siphon action. A suitable embodiment of the inlet and outlet conduits for cooling water is illustrated in Fig. 3. Cooling water is supplied through a conduit 6 which possibly may be connected to a plurality of cooling boxes and after cooling led through an upwardly bent con duit l discharging the water via an overflow 8 into adischarge channel 9 which may be arranged along thetraverser path.

When the cooling boxes are suspended as shown in Figs. 3 and 4 they are preferably provided with a locking device retaining them in their position during the charging and when charged with the material tobe treated. When the boxes are to be emptied the lock is released and the boxes are automatically tilted to a position with their openings directed downwardly due to the axis of the trunnions being situated on the bottom side of the centre of gravity of the charged box. As

this will automatically swing back into its proper position the centre of gravity of the emptied box being on the opposite side of the axis of the trunnions.

In order to make the cooling more effectiv the cooling box may preferably be provided with a stirring device. A simple device for this purpose is shown in Figs. 1 and and comprises cylindrical or spherical bodies 12 suspended by chains l3 which by means of an eccentric disk M or the like are given a vertically reciprocating movement. As the mass in the cooling box solidifies the stirring members will sink to a successively decreasing depth in the mass.

It has been found that the cooling of the molten aluminum sulphate results in forming an aqueous film on the walls of the mold due to the liberation of a certain amount of water from the aluminum sulphate. This aqueous film provides a lubricant which prevents sticking of the solidified aluminum sulphate to the mold and consequently upon inverting the mold th casting will fall therefrom under the action of gravity.

As mentioned above Fig. 4 shows an arrangement comprising a plurality of cooling boxes in connection with a storage room. Outside the storage room a series of evaporating pans may be arranged each being provided with a bottom discharge channel il, projecting into the traverser pathat a level suitable for charging the cooling boxes suspended in the traverser. The cooling boxes are easily carried to the evaporator pan to be emptied by means of the traverser. With the aim to more effectively utilize the space available two traversers may be provided, one at each end of the storage room as illustrated in the figure. It is of course suitable to provide each traverser with a number of cooling boxes appropriate for emptying one evaporator pan completely.

As is evident from the above description the arrangement according to the invention has proved to be of special value in the transforming of fiuid aluminum sulphate into solid pieces. It is, however, obvious that the invention is not limited to this application but may advantageously be used for substances of the same type or -generally for transforming into solid pieces any products which are in fluid form at elevated temperatures and which solidify upon cooling.

For instance upon evaporation of aluminum sulphate solutions it has universally been the practice to cool the molten product from the evaporators in large cooling basins and after the v product has become solidified to break into pieces the solidified slabs by using crowbars and sledges before the pieces may be transported from the cooling basins to the storage bin. It is obvious that the invention involves a substantial simplification and improvement of this old method and at the same time results in a considerable increase of eificiency with less manual work. Thus in a trial plant it was proved that the manual work may be reduced by at least 50 per cent. The work is changed from hard labour to simple supervision. The efiiciency per unit of space used is multiplied several times. The risks of accidents occurring are eliminated and at the same time the security of production is increased.

In spite of the mechanizing the costs of erection and maintenance will not exceed the corresponding costs for the hand work hitherto used and as mentioned above the working costs are reduced by at least per cent.

What is claimed is:

1. Casting apparatus for aluminum sulphate comprising a relatively long narrow mold, a jacket spaced from and surrounding the bottom and sides of said mold providing a space for receiving a cooling medium, a trunnion secured to each end of said mold for rotatably mounting the same, means for conducting said cooling medium to and from said'space, a plurality of transverse hollow partitions extending upwardly from the bottom of said mold and terminating below the top thereof, the interior of said partitions communicating with said space, baflies disposed in said space below said partitions to direct the flow of cooling medium through said space and the interior of said partitions whereby substantially the entire surface of said mold will be cooled, said trunnions being secured to said mold at such a position that the axis thereof will be above the center of gravity of said mold when empty and below the center of gravity of said mold when full whereby upon filling of said mold the same will automatically invert to discharge the contents thereof and upon discharge of the contents will automatically return to upright position.

2. The method of transforming melts of hydrated aluminum sulphates, which are molten in their hydrate water, into a solid block of predetermined size, which comprises providing a relatively long, narrow mold, pouring a mass of such material at a temperature of the order of -105- 115 C. into said mold, chilling the entire surface of said mold in contact with said mass to cause solidification of said mass, whereby to form an aqueous film between the interior surface of the mold and the solidifying mass due to water liberated from the mass upon solidification thereof, said aqueous film acting to minimize the tend- F ency of the mass to stick to the surface of the mold, and inverting said mold to discharge said mass therefrom by gravity.

KARL VALDEMAR LENNSTRM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,316,471 Acton et al Sept. 16, 1919 1,742,391 Hanson et al Jan. '7, 1930 1,803,886 Ausman May 5, 1931 2,204,498 Jung June 11, 1940 2,357,780 Mueller Sept. 5, 1944 FOREIGN PATENTS Number Country Date 3,812 Great Britain Sept. 20, 1880 114,431 Germany Oct. 23, 1900 117.144 Great Britain Juhl 11. 1918

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