US2515693A - Method of filling annealing pots - Google Patents

Description

5 Sheets-Sheet l July 18, 1950 Filed Aug. 9, 194e m W W M f July 18, 1950 E. BUHRER 2,515,693

Y v METHOD 0F"FILLING ANNEALING POTS Filed Aug. 9,l 1946" 3 Sheets-Sheet 2 1" v y 1 l TT 0154/5 yg y' METHOD OF FILLING ANNEALING POTS Filed Aug. 9, 1946 3 Sl'1ee1'.s-Shee'cI 5 Fig. 6

I Fig] /1 T TOKIVE YS Patented July 18, 1950 METHOD OF FILLING ANNEALING POTS Erwin Bhrer, Buchtalen, Switzerland, assigner v to SocitjAno'nyme des Aciries ci`devant Georges Fischer, Schaffhausen, a Swiss com- Dany Application August 9, 1946, Serial No. 689,542 In Switzerland April 3, 1946 For the annealing process'in the production of malleable iron castingsv it is usual t0 embed thev hard white iron castings in a packing material in the annealing pot. The ratiobetween the volume of the metal and the volume of the packing material is on an average 1 to16. It followsl thatfrom the economical point of view the available space in the annealing pot is not used ei-' ciently. Two factors mustkbe borne in mind if a change'is desired inthe ratio between the volume ofthe metal an the volume of the packing material. A i l. i

1. In the case of the production of European malleable iron castings the packing material must supply a quantity of oxygen corresponding to the weight of the castings.

2. The packing material must completely ll up all' the empty spaces in and between the castings in order to vprevent warpage of the castings at the high annealing' temperatures.

The present invention provides a considerable` improvement of the volume ratio in favour of the weight of the castings. This improvement is obtained by vibration of the annealing pot during the iilling` operation, the castings being lledrin" first andthen the packing material. In adding the packing material the pot must be submitted to the vibrations in any case, whereas the castings alone are vibrated only if necessary.

Practically the vibratory movement cannot be produced by knocking or by rocking the annealing pot. `Undampedvperiodic oscillations are best suited for the vibration, as they effect ay quick levelling downv of theadded packing material, the latter filling up all the cavities in and between the castings.

The hard white iron castings are very brittle and' must be handled carefully. In order' to prevent cracks in the hard iron castings the vibratory movement must not cause the castings t0 bump L against one another. The oscillations must assume the character of an undulatory curve in order to prevent the development of detrimental stresses when the direction of the oscillatory movement is reversed.

For the application of the present invention devices should be used which produce the vibratory movement mechanically as oscillations in a horizontal plane.

The drawings illustrate some practical forms of the said devices.

Fig. 1 shows a longitudinal section of a vibrating device.

Fig. 2 shows a plan View of the said vibrating device.

4 Claims. (Cl. 148-1) Fig. 3 shows a front view of the said vibrating device.

Fig. 4 shows a cross section nthrough the vibrat ing device.

Fig. shows a clamping fixture for the annealing pot.

. Figs. 6 and 7 show alternative vibrating equipments with different driving appliances.

The vibrating apparatus in Fig. 1 is supported on four spring bars I and consists of a frame 2 in which the annealing pot 3 is xed, and of the vibration generating mechanism.

The annealing pot 3 rests on three flat supports 4 within the frame 2; it is fixed both horizontally and vertically by the clamps 5 and 5. The vibratory movement is produced by two synchronized revolving eccentric flywheels 8, both driven by the samey motor l. These synchronized eccentric flywheels Ii impart a circular oscillation in a horizontal plane to the frame 2 and to the annealing pot 3 clamped therein, and further to the contents of the pot 3.

The annealing pot 3 is filled as follows: An empty annealing pot 3 is lowered into position into the frame `2 by means of a crane and allthe clamps 5 and 6 are tightened. The white iron castings 9 are then packed into the annealing'pot 3 as tightly as possible. When the castings 9 have reached a certain height they are shaken down. It is'quite immaterial whether they fill only one half or reach to the top of the annealing pot 3. Thisv causes the smaller castings to run into thev spaces between and vin the larger castingsto the greatest possible extent. Then the packing material I I is poured into Athe annealing pot 3 from a hopper, the outlet Ill of which is indicated in Fig. 4. The vibratory movement generated bythe eccentric flywheels 8 causes 'the packing material Il to fill up the spaces left in and between the white iron castings El.

As soon as the spaces between the castings have been lled with the packing material, the clamps 5 and 6 are loosened and the annealing pot 3 is lifted out of the frame 2 by means of a crane.

The clamps 5 and B must be very strong to be able to transmit the considerable stresses, due to the circular oscillations, from the frame 2 to the annealing pot 3. On account of the elasticity of the frame 2 and of the walls of the annealing pot 3, special attention must be given to the design of the clamps 5 which transmit the stresses horizontally.

In Fig. 5 the annealing pot is indicated by M, the frame by I5, while I6 is the spindle of a horizontal clamping screw. An adjustable Weight Il tightening, the lever Il must be pushed over the i square part I8 in such a way that the weight 22 will have a tendency to tighten the spindle under the eiect of the vibratory movement.

There are various methods of producing lthe vibratory movement and imparting it to the anf nealing pot. An example of a vibrating device is shown in Fig. 6, in which circular oscillations are generated by two separate eccentric iiywheels driven by two synchronized motors. Fig. 6 shows schematically a frame 24, resting on four-'spring bars 25, into which the annealing pot 26 is placed. Clamping devices to fix the pot 26 in position are indicated at 21. horizontally are not shown.l Fixed atboth ends of the frame 24 are two synchronized motors 128 with two eccentric ywheels 29. The switch gear is arranged in such a way that the two motors are synchronized and can only revolve together.

In order to prevent angle displacement in the` synchronization both motors can be coupled mechanically by means'of -the shaft 30.\

Fig. 7 illustrates a 4device in which thevibrating movement is produced by electromagnets. In this case the movements do not take the form of circular oscillations, as in Figs. 1 to 6, but of horizontal pendular oscillations of the ends of the spring bars 32 supporting the frame 33. The Eannealing pot 34 is set into the frame 33 andfixed in position by the clamps 35 and 36. The stationary parts 39 and 40 of two three-phase alter-r nating current electromagnets 3l and 38 are xed on a support rmly embedded in foundations. The moving armature parts 4I and 42 of the electromagnets are connected to the frame 33 and transmit the pull of both magnets 3'l.and 38 to the fra-me 33 and to the annealing pot 34, and therefore to the contents .of the latter. i

The shaking down of the white iron castings and the filling of the intermediate spaces with the packing material is obtained with either of the apparatus shown in Figs. 6 and 7 inexactly the same way as in the case of the device shownin Figs. 1 to 5. The Vuse of a vibratory movement gives a mechanical method of packing white ironcastings which is much better than a packing by hand. The only way of lling the spaces between and in the castings in such a way that a furtherv displacement of the castings is impossible is to apply a vibratory movement. Experiments yhave rIyhe clamping devices acting.

proved that practically no deformation of the castings occurs when using iron ore as a packing material for annealing. The method of packing used hitherto necessitated additional work for the straightening of the castings warped during annealing, the straightening operation being performed either on hot or on cold castings. With the packing method according to the present invention it is possible to make use of the iilling capacity of the pots to the greatest possible extent.

The main object of the present invention is to reduce production costs in general, and particularly thevcosts of annealing, without aifecting the quality of the nal product. Several items of the costs in the, production of malleable iron castings are favourably influenced, e. g. less heat per weight unit of castings is required for annealing,

the costs for annealing pots are lower, the costs of labour are reduced, less work is needed for straightening warped castings, etc. At the same time the total output of the annealing plant is increased.

I claim:

1.. A method of lling annealing pots for the purpose lof annealing white malleable iron castings in furnaces, comprising placing the hard iron castings into the pot, adding packing material and subjecting the contents of the pot, at least during the lling of the packing material, to a horizontal vibrating movement to cause leveling down of the packing material and to cause the packing material to -ll the spaces between, and in, the iron castings.

2. A method Iof filling annealing pots according to claim 1, wherein the annealing pot is filled in layers. l

3. A method of filling annealing pots according to claim 1 in which the pot is rst filled completely with castings, the packing material being added afterwards and made to ll any remaining spaces between and in the castings by the application of said horizontal vibratory m-ovement.

4.1 A method of filling annealing pots according to claim 1 wherein the vibratory movement is constituted of undamped periodic oscillations, the oscillations having the character of an undulatory curve and being in the horizontal direction.

ERWIN BHRER.

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

` UNITED STATES PATENTS l

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