US1536541A - Process and apparatus for magnetic separation - Google Patents

Description

May 5,1925. 1,535,541

' G. ULLRICH V PROCESS AND APPARATUS FOR MAGNETIC SEPARATION Fig Patented May 5, 1925.

UNITED STATES PATENT OFFICE.

GEORG ULLRICH, OF MAGDEBURG, GERMANY. ASSIGNOR TO THE FIRM FRIED.

KRUPP AKTIENG-ESELLSCHAFT, GRUSONWERK, 0F MAGDEBURGr-BUCKAU, GER- MANY.

PROCESS AND APPARATUS FOR MAGNETIC SEPABATION.

Application filed my 1, 1923. Serial No. 636,032.

To all whom it may concern:

Be it known that I, GEoRe ULLRIGH, engineer, citizen of. the German Empire, residing at Winterfeldstrasse 2, Magdeburg, Germany, have invented certain new and useful Improvements in Processes and Apparatus for Magnetic Separation, of which the following is a specification. The present invention relates to a process of magnetic'separation of materials of all kinds according to which the materials are delivered to the rotating surface of a drum separator. According to this process the separation is accomplished in such a way that the magnetic material in the effective magnetic field is retained on the separating surface and drops outside of the field. The non-magnetic material is previously thrown off while still in the magnetic field or falls from the rotating surface. In this process however, the disadvantage has arisen especially when the material is delivered in a thick layer that a portion of the magnetic material farthest from the ole'edges is not retained, but is discharged with the nonmagnetic material. This loss of magnetic materialcan be avoided or at least diminished by delivering the material tobe separated in a thin layer. Such an expedient however, diminishes greatly the'output of the separator. It has further been attempted to strengthen the magnetic influence on the material by fixing induced rings on the drum, but in spite of the increased magnetic attraction loss of magnetic. material is not avoided.

According to the present invention these disadvantages are avoided by passing the material to be separated through a plurality of annular zones of a magnetic field arranged concentrically or co-axially around a horizontal axis, the field. strength of said zones being substantially equal or increasin from the inner to the outer.- The materia to be separated is lead through the outer zone fields to the inmost field where the main separation takes place. The material not retained in the-inmost field is thrown outwardly from the rotating drum and durto the inmost zone field can be so affected, by means of a guide chute for instance, that it is not influenced during its passage through the outer zone fields and is subjected to a primary separation in the inmost field. On the other hand, the material tobe separated may be fed freely through the outer zone fields to the inmost in such a manner that a preliminary separation is effected in the outer-fields before the material reaches the inmost field.

The construction of a separator for car rying out the process according to the present invention allows various possibilities of design. For instance, the primary pair of poles which form the inmost field.

may be fixed within the drumor allowed 'to rotate with the latter, while the secondary pair or pairs of poles which form the outer nal section of a magnet field, designed for the new process, in three different forms.

Fig. 3 is a top plan View of Fig. 2.

Fig. 5 is a section on the line AB of Fig. 4.

Figs. 6 and 7 show details of'special construction. Fig. 6 being a longitudinal section of a pair, of secondary poles and Fig. 7 a partial view of the separating zone- Fig. 2 illustrates a cross section through I a'drum according to Fig. 1. on a small scale.

According to the construction illustrated in Figs. 1 to 5 a drum 2 rotates about a horizontal axis 1, a pair of poles 3 being fixed within the drum. These poles are provided with annular edges 4 which may be attached directly to the poles themselves or to pole pieces provided on the same. The magnets or poles 3 may be axially displaceable in known manner for the purpose of adjusting.

the field. The edges 4 form the primary poles, while the secondary pair of poles 5 is fixed on the outside of the drum 2. The attracting edges of the rings 5 are sharpened whereby an annular recess 6 is formed be-- tween the edges 5 and the drum 2 and this recess can be advantageously filled with a non-magnetic substance. Between the poles 4 and 5 two magnetic zones 7 and 8 respectively are formed and by means of an axial adjustment of the annular poles the zones 7 and 8 may be made of substantially equal strength or the' outer zone 8 may be made stronger than the inner zone 7. The introduction of the material to be separated can be accomplished for instance, by means of a channel 9 (see Figs. 1 and 2) in such a manner that the material must pass through the outer field 8 on its way to the inner field 7 so as to be primarily influenced by the former. In this manner in its passage through field 8 the material is subjected to a preliminary separation. On .the other hand, the material can be conducted to the inmost field in such a manner that it is not influenced by the outer field (see Figs. 4 and 5.) In this instance the guide channel 9 extends into the annular groove formed by the poles 5. In either instance however, the main separation is affected in the inner field, that is, on the drum 2 and the greatest portion of the magnetic material will be retained by the poles 4. The non-magnetic portion as well as that magnetic portion of the material which ,is not retained by the poles 4 will be thrown ofi', but before their escape both portions must pass through the outer field 8 whereby a supplemental separation is efiected.

In the constructional example according to Fig. 8 the primary poles 4 also rotate. The field gap between these poles is closed by means of an annular shell 10 which like wise rotates. The method of operation cor-- responds to that described above.

The formation of two or more concentric ring zones for carrying out the present invention may also be obtained by providing each annular pole with several co-axial edges 11 as shown in Fig. 6. Thus a supplemental magnetic field is formed between each pair of the edges 11. Moreover, several pairs of secondary poles may be provided in the same manner.

As stated above the strength of the fields can be regulated by providing for an axial displacement of the annular poles and two or more of such field systems can be arranged along the axis of a drum separator.

' The secondary pair of poles can likewise be formed 'by pairs of bands running from one or more guide rollers over the drums. The opposed edges of the bands form the fields for accomplishing the supplemental separation. Two or more of such bands can be placed one upon another and they may be made entirely or partly of magnetic substances.

The annular grooves formed between the pairs of secondary poles are also well adapted for wet magnetic separation.

' longitudinal The pole ed es formingthe ring fields may also be provi ed with teeth running in the direction of their circumference.

As will be seen by the example cited there are numerous possibilities of separator conand in what manner the same is to be performed, I declare that what I claim is:

1. A process of magnetic separation consisting in conducting the material to be separated through a plurality of annular zones of a magnetic field, said zones lying in radial succession relative to a central axis,

whereby. the material passes through the outer field, to the inner field, andagain through the outer field.

2. A process of magnetic separation consisting in conducting the material to be separated through a lurality of annular zones of a magnetic fie d, said zones lying in radial succession relative to a central axis, the strength of said fields increasin progressively from theinmost whereb t e material passes through the outer fie d, to the 215131 field, and again through the outer 3. A rocess of magnetic separation consisting in conducting the material to be separated through a lurality of annular zones of a magnetic fie (1, said zones lying in radial succession relative to a central axis whereby the material passes through the outer field, to the inner field, and again through the outer field, the material being first subjected to magnetic influence on reaching the inner field.

,4. A rocess of magnetic separation consisting in conducting the material to be separated through a plurality of annular zones of a magnetic field, said zones lying in radial succession relative to a central axis, the strength of said fields increasing progressively from the inmost whereby the material passes through the outer field, to the inner field, and again through the outer field, the material being first 'sub'ected to magnetic influence on reaching t e inner field.

5. In a drum separator of the kind as described a pair of primary magnetic oles y spaced relative to said rum and a'pair of secondary magnetic poles radially aligned with said primary magnetic poles.

6. In a drum separator of the kind as describ d, a plurality of annular pole pairs arranged in radial succession relative to a described, a plurality of annular pole pairs arranged in radial succession relative to a central axis, the respective oles of each oi said pole pairs being space longitudinally relative to said axis, the material to be treated being passed into the magnetic fields thus formed in a direction transverse to the axis, the fields of said pole pairs increasing in strength progressively from the inmost to the outer.

8. In a drum separatorof the kind as described, a plurality of annular pole pairs arranged in radial succession relative to a central axis, the respective oles of each of said pole pairs being space longitudinally relative to said axis, the material to be J treated being passed into the magnetic fields thus formed in adirection transverse to the axis, and means for subjecting the material to be separated first to the influence of. the

magnetic field of the inmost pole pair.

9. In a drum separator of the kind as described, a plurality of annular pole pairs arranged in radial succession relative to a central axis, the material to be treated bein passed into the magnetic fields thus form in a direction transverse to the axis, the opposed edges of said pole pairs being provided with circumferential serrations and said serrations being filled with a non-magnetic substance.

10. In a drum separator of the kind as dev scribed, an inn'er and an outer pole pair arranged in radial succession relative to the axis of the drum, the inner pole pair lying within the drum, the outer pole pair being external thereto. V

In testimony whereof the foregoinfg' specification' is signed in the presence 0 a witness.

GEORG ULLRICH. Witness:

E. H. Gram.

Images