US 1297159 A
Description (OCR text may contain errors)
C. W. J. HEDBEBG.
APPLICATION FILED FEB. 1. 1918.
1,297,159. Patented Mar. 11,1919.
Q auuantoz dummy the material to be "sists of a plurality tion reference structure for the CARL WM. J. HEDBERG, or NEW BRITAIN, CONNECTICUT, ASSIGNOR CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW TO RESEARCH YORK.
I ELECTRIC SEPARATOR.
Specification of Letters Patent.
Patented Mar. 11, 1919.
Application filed February 7, 1918. Serial No. 215,882.
To all whom it may concern:
Be it known that I, CARL WILLIAM JULIUS HEDBERG, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Electric Separators, of which the following is a specification. 1
The present invention relates to apparatus for separating particles of a mixture by the action of electrostatic charges.
It is the object of the invention to provide a device of the class referred to which makes it DOSSiblG to sift or separate particles on a commercial scale and in a simple manner.
With this object in view the invention comprises principally a t-reater chamber so constructed and arranged that a substantially uniform electric stress is produced transversely of the chamber, means for pass 'ing the material to be treated through the field of stress and'means for collecting the particles forced out of their normal path of travel by the electric action.
For a fuller understanding of the invenis had to the appended drawings in Which Figure 1 is a plan view of an arrangement showing one embodiment of the invention;
Fig. 2 a vertical section through the device shown in Fig. 1 and Fig. 3 a fragmentary horizontal section.
In the drawings 1, 2, 3 and 4 are upright beams representing .a simple supporting apparatus. The tubular portions 6 and 7 as well as the intermediate structure define a cylindrical passage for treated.
he intermediate structure referred to conchambers 8, 9, 10, 11 and 12. These chambers terminate in circular edges 130]? sub stantially the same diameter as-the tubulal portions 6 and 7 and concentric therewith. For the purpose of the invention it is not material whether the chambers extend entirely around the cylindrical passage or are made in a plurality of sections as indicated in the drawing by the numerals 8, 8, 8", 8", so long as they communicate with the cvlindrical passage along the whole periphery.
The chambers 8, 9, 10, 11 and 12 are down be protected by any suitable means,
of verticallv arranged Wardly inclined for a purpose that will be subsequently stated and terminate in chutes 14;, 15, 16, 17, 18, etc., controlled by gates 19 having handles 19.
The whole structure comprising the chambers and chutes is preferably supported from the uprights by means of braces 20, 21 and 22. 1
At the top of the uprights is mounted by means of insulators 24a frame 25 for sup porting the discharge electrode 26 which extends through a central insulator 27 into the cylindrical passage and is at the bottom spaced and held taut by strain insulators 28 in well known manner.
A chute 30 is advantageously used adjacent the upper end of deliver the material to be sifted into the cylindrical passage.
This chute is preferably made of electrical insulating material. The outlet 31 of the chute is centrally located to properly distribute the material, and may have a fun nel shaped portion 31' or other means for carrying the particles into close proximity to the electrode 26.
The discharge electrode 26, which passes through the lower portion of the chute, may as for instance by a sleeve 31, against mechanical injury. As an additional electrical protection this sleeve may be made of insulating material.
Below the cylindrical passage is placed a hopper 33 to collect material and a gate 36 may be used to control the collection of the material. a
The electrodes are charged in the well known manner from a high tension circuit supplying:unidirectional current, one pole being connected to the discharge electrode by wire 35 and the other to ground.
' The operation of the apparatus is as follows:
.The material to be sifted .is discharged uniformly into the chute 30 to deliver it in a continuous stream into the cylindrical passage. As it passes down the passage itcrosses the intense field of electric stress produced between the discharge electrode and the surrounding structure which acts charge electrode toward the other electrode which is of opposite sign and may be termed the collecting electrode.
Some of the particles are rapidly charged and are rapidly propagated toward the collecting electrode. @thers are charged less rapidly, others still less rapidly and others to such a small degree that their direction is not appreciably affected. in such cases where the difi'erent particles are differently afi'ected, as just indicated, some will be forced at once across the cylindrical passage and drop into the chamber 8, others will be forced across more gradually and be depos ited in the chamber 9 and so on. Others will pass down to the bottom without material deflection and fall into the hopper 33.
W here the material is more or less uniform in its susceptibility of being charged, but the difierent particles are not uniform in point of weight, the lighter particles will be forced more quickly toward the collecting electrode than others and will accordinglybe received in the difierent receiving or collecting chambers, while some will pass down into the hopper.
Due to the inclination of the chambers the material received therein passes down into the various chutes and is drawn ofi at inter vals by opening the gates 19. Similarly the material received in the hopper 33 may be drawn ofi by opening the gate 36.
It is thus seen that by the arrangement disclosed materials can be classified or graded in various ways. Since the electric action is substantially uniform, the classification is dependably uniform.
The present disclosure is merely intended as an embodiment of the invention for broadly illustrating the principles upon which the invention is based. lit is understood that the mechanical execution may be varied in numerous ways.
With some mixtures, if a close differentiation of the particles according to size and other properties is desired, it is necessary to impart to the particles a relatively high initial velocity. To impart to the particles a definite initial velocity, it is merely neces sary to dispose the outlet end 31 of the chute 30 a definite distance above the chamber 8 and vary the height of the section 6 accordingly. The electrode 26 is preferably surrounded, so far as it extends through the section 6 b an insulating medium to render it a zo relatively inactive.
if desired, a special perforated electrode or screen electrode may be placed immediately adjacent the edges 13 between the tubular portions 6 and 7. The particles charged are driven transversely of the cylin drical passage as before described and their velocity, together with the effect of electrical windage from the discharge electrode, is sufficient to cause them to pass through the plurality of openings or perforations in said electrode and to be collected in the various chambers.
While in the embodiment shown the movement of the particles through the electrical field is due to gravity alone, suitable means may be provided, as for instance pneumatic pressure, for forcing them through the field. For this purpose an air jet 3'? may be used as shown in Fig. 2.
it is also possible to change the form of electrode 26 without materially aifecting the operation of the device.
1 therefore do not want to be limited to the exact structure shown.
The apparatus may be used for classification or grading of various kinds of material, as is obvious.
1. An apparatus for sifting material comprising means for forming of the material a stream of freely suspended particles, means for producing an electric stress transversely of and continuously along said stream and means distributed along said stream for separately receiving particles forced laterally of the stream by the electric stress.
:2. An apparatus for sifting material comprising means for defining a passage, means for producing an electric stress along said passage transversely thereof and a plurality of receiving chambers contiguous to and communicating with said passage.
3. An apparatus for sifting material comprising means for defining a vertical passage, means for producing an electric stress in said passage and transversely vertically arranged receiving chambers contiguous to and communicating with the saidpassage.
a. An apparatus for sifting material comprising means of electrical conducting material for defining a vertical passage, a discharge electrode extending into said passage and a plurality of vertically arranged receiving chambers communicating with the said passage.
5. An apparatus for sifting material comthereof, and a prising electrode means constructed and arranged to define a vertical substantially cylindrical passage, a discharge'electrode extending into said passage and a plurality of vertically arranged receiving chambers communicating with the said passage.
6. Apparatus for sifting material comprising'electrode means constructed and arranged to define a vertical passage, a discharge electrode extending into and centrally of said passage, and a plurality of vertically arranged receiving chambers surrounding the passage and communicating therewith.
7. Apparatus for sifting material comprising electrode means constructed and arranged to define a vertical passage, a discharge electrode extending into and centrally of said passage, a plurality of vertically arranged receiving chambers surrounding the passage and means at the upper end of the passage for delivering material to be sifted thereto.
8. Apparatus for sifting material comprising electrode means constructed and arranged to define a Vertical passage, a discharge electrode extending into and cen- 10 trally of said passage, a plurality of verti- In testimony whereof I afiix my signature in presence of two Witnesses.
CARL WM. J. HEDBERG.
ROBERT B. OTT, MARGARET E. OTT.