US2258767A

US2258767A - Electrostatic separating apparatus

Info

Publication number: US2258767A
Application number: US292980A
Authority: US
Inventors: Herbert B Johnson
Original assignee: RITTER PRODUCTS CORP
Current assignee: RITTER PRODUCTS Corp
Priority date: 1939-09-01
Filing date: 1939-09-01
Publication date: 1941-10-14
Anticipated expiration: 1958-10-14

Description

Oct. 14, 1941. H, B, JQHNSQN 2,258,767

ELECTROSTATIC SEPARATING APPARATUS Filed Sept. l, 1939 ATTORNEYS. ai

Patented ocr. 14, 1941 UNITED STATE ELECTROSTATIVC SEPARATING APPARATUS t Herbert B. Johnson, Rochester, N. Y., assignor to Ritter Products Corporation, Rochester, N. Y., a corporation of New York Application September 1, 1939, Serial No.1292,980

3 Claims. (Cl. 209-127) My invention relates, generally, to electrostatic separating apparatus and it has particular relation to improvements in the electrode construction thereof.

In my Patent No. 2,135,716, issued November 8, 1938, I have shown a plurality of pairs of 'separating electrodes which are connected across a source of high direct'voltage as a result of which a high potential electrostatic field is maintained between each of the pairs of electrodes. The electrodes are generally cylindrical in shape and both of them are rotatable. The material to be separated falls onto one of them, called the material conveying electrode, and it is carried thereby into the electrostatic field where the separating action takes place. It is highly desirable that the high potential electrode have a smooth surface at all times in order to prevent the piling up of particles thereon thereby forming discharge points and causing arcing to take place between the electrodes. `In my patent I have provided a wiper that is stationarily mounted with respect to the high potential electrode and engages its surface as it rotates for the purpose of polishing it and removing therefrom any particles which might tend to form discharge points. While this construction is generally satisfactory, I have found that it is, likely to result in the wearing of A grooves in the high potential electrode due to the lodging of relatively hard particles in the wiper in such manner as to serve as cutting edges. This is undesirable since it results in a roughened surface on the high potential electrode and the formation of sharp corners or points from which arcing may take place.

Accordingly, it is to the solution of this problem that my present invention is addressed.

|lhe object of my invention, generally stated, is to provide for causing relative longitudinal movement between a rotatable cylindrical electrode of a pair of separating electrodes and a wiper associated therewith.

Another object of my invention is to provide for causing longitudinal movement of the wiper relative to the associated electrode.

Still another object of my invention is to cause longitudinal movement of an electrode relative to a wiper stationarily mounted with respect thereto.

Still another object of my invention is to provide'for translating the relative movement of an electrode into relative longitudinal movement of a wiper associated therewith.

A further object of my invention is to provide for repeatedly jarring one of the electrodes in order to'cause particles thereon to fall o. l

Otherobjects of my invention will, in part, be obvious and in part appear hereinafter.

more readily My invention, accordingly, is disclosed in the n embodiments thereof shown in the accompanying drawings, and it comprises the features of construction, combinationof elements and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature andv scope of my. invention, reference may be had to the following detailed description taken in connection lwith the accompanying drawing, in which:

Figure 1 is a view, in front elevation, of a high potential electrode and wiper therefor arranged to be osclllated with respect thereto;

Figure 2 is a detail sectional view, taken along the line 2-2 of Figure 1, showing, in addition, the material conveying electrode;

Figure 3 shows a modification of the construction illustrated in Figure 1; and

Figure 4 shows still another modification of the construction illustrated in Figure 1.

Referring now particularly to Figures 1 and 2 .t of the drawing, it will be observed that the refelectrode that is generally cylindrical in shape jonto which the particles of material to arated fall and by means of which they are conerence character Ill designates a high potential and may be of any desired length. The electrode I0 forms one of a pair of electrodes, the other electrode II being a material conveying electrode be Sepveyed into the electrostatic field that is maintainedabetween electrodes I0 and II under normal operating conditions by connection to a suitable source of high voltage direct current. An angle I2 is provided for guiding the material to be separated onto the material conveying electrode Il. between the electrode II and the angle I2 becomes filled with the material to be separated It will be understood that the space j l1 that are carried by uprights IB and I9, respectively. Any suitable means may be provided for rotating the high potential electrode III. For example, a gear wheel 20 may be provided on the shaft I5, as shown, and it may be driven through suitable driving means as will be readily understood.

The material conveying electrode II is arranged to be rotated in the direction indicated by the arrow 2|. The high potential electrode I may be rotated in either direction depending upon the operating conditions.

As set forth in my patent, referred to hereinbefore, it is desirable to maintain the surface of the high potential electrode III in a polished condition in order to prevent the building up of discharge points thereon as a result of the collection of particles on the surface of the material being separated. For this purpose a wiper 24 is provided which extends substantially the entire length of the high potential electrode I3 and covers about one quarter of its circumference. The wiper 24 may be formed of felt impregnated with a suitable abrasive material such as finely ground Carborundum, rouge, crocus,

, aluminum oxide or otherpolishing powder. The

wiper 24 is held in proper position by means of a support member 25 in the form of a metal strip to which the wiper may be cemented.

' Ears 25 are provided at the ends of the support member 25 and they are attached, as shown, to the ends of insulators 21 which are similar to the insulators I3. The insulators 21 are mounted on

short shafts

28 and 29 which are arranged'for endwise movement in bearings 30 and 3 I, respectively, that are suitably mounted on the uprights I8 and I9.

As previously indicated, it is desirable to provide for relative longitudinal movement between the high potential electrode I0 and the wiper 24 in order to prevent pitting of the surface of the electrode. For this purpose collars 34 and 35 are provided at the ends of the insulators I3 with

sinuous grooves

35 and 31 therein, as illustrated. Cooperating with these

grooves

35 and 31 are pins 38 and 39 which extend from end members 40 and 4I, respectively, of the insulators 21. If desired, the pins 38 and 33 may be provided with antifriction rollers in order to reduce the friction with the sides of the

grooves

36 and 31.

It will now be apparent that rotation of the electrode l0 relative to the wiper 24 causes, in addition, relative longitudinal movement between it and the wiper 24 because of the endwise movement thereof in the bearings 30 and 3I as the pins 38 and 39 follow the

grooves

35 and 31. In this wise the surface of the electrode I0 is 'maintained smooth and polished and there is no likelihood of the formation of grooves therein as a result of the presence of hard particles in the wiper 24.

The material conveying electrode I I may also be provided with a wiper 42 which is formed of material that is similar to the material of which the. wiper 24 is formed and impregnated as described. The wiper 42 may be held in place by any suitable means on the angle AI2 such as by bolts 43, as shown.

In Figure 3 of the drawing there is shown another embodiment of my invention. As in the construction as shown in Figure 1 of the drawing, the high potential electrode I0 is arranged for rotary motion only while the wiper 24 and its support member 25 are mounted for endwise movement in the bearings 30 and 3|. The support member 25 and associated parts are biased to the right as viewed in the drawing by a compression spring 45 which reacts against a suitable reaction member 45 that may be carried by the upright I5. In order to move the support 25 and the wiper 24 carried thereby longitudinally of the electrode I0, a cam 41 is mounted on a shaft 4l and isarranged to y'engage the right hand end of the short shaft 23, as shown. The cam 41 may be yrotated by any suitable means such as through a gear 43 mounted on. the shaft 43 and driven from any suitable driving means.

It willgbe apparent that the rotation of the cam 41 will cause Iendwise movement of the support 25 and the wiper 24 carried thereby relative to the electrode I0 in one direction and that movement in the opposite direction will be effected by the spring 45. This relative longi tudinal movement will take place while the electrode IU is being rotated as described. The desired polishing action of the surface of the electrode will then be effected because of the combined rotary and translatory movement of it with respect to the wiper 24.

In Figure 4 of the drawing there is shown another embodiment of my invention. In this embodiment the electrode I0 is mounted for endwise movement relative to bearings I5' and I1', while the wiper 24 and the support 25 therefore are arranged to be relatively stationary. Instead of moving thewiper 24 along the surface of the lzelectrode, the electrode is moved along the wiper As shown. the electrode I0 is biased to the right, as viewed in the drawing, by a compression spring 5I that is mounted within a suitable tubular housing 52 carried by the upright I5. An ad- Vjustable plug 53 is threaded into the end of the tubular housing, 5I and its position can be changed in order to vary the biasing force of the spring 5I.

In order to effect endwise movement of the electrode I0 in the opposite direction, the ratchet wheel 54 is mounted on the shaft I5 and it is arranged to engage a tooth or pawl 55 that may be carried by any suitable support, such as the support member that is mounted on the upright I3. As the electrode I0 is rotated through the gear 2li, it will bev moved endwise to the left as the teeth of the ratchet wheel 54 ride over the tooth or pawl 55. 'The spring 5I will return the electrode I0 to the right as each tooth of the ratchet wheel 54 is passed.

Because the electrode Ill is moved to the right sharply by the spring 5I as soon as each tooth of the ratchet wheel 54 is passed, a certain amount of jarring action takes place which tends to shake oif particles that might otherwise tend to cling to the surface of the electrode III. This action, in addition to the relative rotary and translatory movement between the wiper 24 and the electrode I 0 serves to keep the surface of the electrode free from any of the particles of the material being separated and at the same time prevents the formation of ridges or grooves in the electrode surface.

Obviously the positions of the ratchet wheel 54 and of the tooth or pawl 55 could be reversed without departing from the scope of this invention, SinceV further changes may also be made in the above constructions and different embodiments of the invention may be made without departing from its scope,-it is intended that all matters contained in the foregoing description or shown in the accompanying drawing shall be nterpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In an electrostatic separator for separating a product comprising mixed particles, in combination, a rotatable cylindrical electrode, wiper means containing abrasive material cooperating with said electrode for polishing the same and extending substantially the entire length thereof, and pin and cam means operatively interconnecting said electrode and said Wiper means whereby rotation of the former causes slight relative longitudinal movement between said electrode and wiper means 2. In an electrostatic separator for separating a product comprising mixed particles, in ccmbination, a rotatable cylindrical electrode, wiper means containing abrasive material cooperating with said electrode for polishing the same and extending substantially the entire length thereof,

insulator means mounting said electrode and wiperY means for relative longitudinal movement, and pin and cam means operatively intercon necting said vinsulator means remote from said electrode and wiper means whereby rotation of the former causes slight relative longitudinal movement between said electrode and wiper means.

3. In an electrostatic separator for separating a, product comprising mixed particles, in combination, a rotatable cylindrical electrode having rotatable therewith a. sinuous groove, wiper means containing abrasive material extending substantially the entire length of said electrode and engaging the same and movable longitudinally thereof for polishing the same, and a pin carried by said wiper means and extending into said sinuous groove whereby the Vrotary movement of said electrode is translated into longitudinal movement of said wiper means.

HERBERT B. JOHNSON.