US3501002A - Vibratory separator - Google Patents

Description

March 17, 1970 w. J- TALLEY, JR 0 3,501,002

VIBRATORY SEPARATOR Filed Nov. 28, 1966 3 Sheets-Sheet 2 INVENTOR. WALTER d. TALLEY J2.

A77Z72/VEY March 17, 1970 w, TA Y, JR 3,501,002

VIBRATORY SEPARATOR Filed NOV. 28, 1966 v 3 Sheets-Sheet 5 ill-Maw i ya) 1 Q IN VEN TOR.

A77'0ENE Y WALTER J. TAUEY JR.

United States Patent,

3,501,002 VIBRATORY SEPARATOR Walter J. Talley, Jr., Los Angeles, Calif., assignor to SWECO, Inc., a corporation of California Filed Nov. 28, 1966, Ser. No. 597,278 Int. Cl. B07!) 1/50, 1/28 US. Cl. 209-240 11 Claims ABSTRACT OF THE DISCLOSURE A vibratory separator, and screening structure therefor mounted in a housing, the screening structure including a first portion having a central discharge opening therein and a second portion upstanding at near the periphery of the first portion such that material which does not fiow through the second portion is delivered to the first portion near the periphery thereof. A material feed arrangement is provided adjacent the second portion of the screening structure for delivering material adjacent the inside surface of the second portion, preferably substantially tangential thereto. Means also are provided adjacent said portions of the screening structure for cleaning the same.

The present invention relates to improvements in separating devices such as vibratory screening apparatus and is particularly applicable to vibratory screen separators of high volume capacity.

Although a horizontal circular screen vibratory separating device of the type disclosed, for example, in US. Patents 3,035,700; 3,156,643; 3,029,946; 2,777,578; 2,- 753,999; 2,714,961; 2,696,302; 2,676,706 and 2,284,671 gives a great deal of flexibility in the separation of material by the selection of proper screen size and the appropriate adjustment of the vibrating device which drives it, there have been certain applications in which the vibratory screen apparatus has not been as successful as it might be.

For example, when using the conventional vibrating screen separator to remove a relatively small amount of solids from a large volume of liquid, the capacity of the separator is materially retarded by the limited surface area of the horizontal screen because there is a finite rate at which the liquid will pass through the screen, particularly in the presence of the solids, which tend to concentrate on the screen surface. In such instance, the capacity of the separator to remove the relatively small amount of solids is limited by the ability to move the solids across the screen and agglomerate the solids with larger particles so that a maximum open screen area is available. to the liquid. Further, when using the vibrating screen separator to remove a relatively small amount of solids from a large volume of liquid, particularly where solids are finely divided or are semi-solids, the. screen cloth also has a tendency to become bridged or clogged by the particulate 0r semi-solid material. This is particularly true in making a preliminary separation between water and finely divided solids in raw sewage where the sewage contains suspended grease often found in domestic household wastes. In these instances, the semi-solid grease tends to bridgeand adhere to the screen cloth and gradually reduces the capacity of the cloth to discharge water.

It is, therefore, an object of this invention to provide an improved vibratory separator which employs a horizontal screen.

It is another object of this invention to provide an improved vibratory separator, which separator employs a circular screen and, when subject to vibration, is particularly adapted to the separation of large quantities of liquid ma-- terial from a relatively small quantity of solid material.

It is a still further object of this invention to provide a circular screen vibratory separator having a novel arrange 3,501,002 Patented Mar. 17, 1970 ice ment which enables the separator to operate at increased capacities by increasing the screen area available with a given diameter unit.

Yet another object of the invention is to provide a vibratory separator unit which can be cleaned either while in operation or during short pauses in the operation without the necessity of dismantling the unit or removing the screen therefrom.

A further object of the invention is to provide a vibratory screening apparatus useful in the separation of mixtures of solids of different sizes as well as liquid-solid mixtures.

With the above objects in mind and other objects which may hereinafter appear, reference is directed to the drawings accompanying the specification in which:

FIGURE 1 is a vertical cross-section view of a vibratory screening apparatus of this invention having a circular configuration;

FIGURE 2 is a fragmentary plan view taken through 2-2 of FIGURE 1;

FIGURE 3 is an enlarged fragmentary, sectional view taken through 3-3 of FIGURE 4;

FIGURE 4 is an enlarged, fragmentary, sectional view of the peripheral screen mounting shown generally in FIGURE 1;

FIGURE 5 is an enlarged, fragmentary, sectional view of a portion of FIGURE 1 illustrating the center screen mounting detail;

FIGURE 6 is a fragmentary, sectional view of the upper, vertical screen mount shown in FIGURE 1;

FIGURE 7 is a detail of the rotating coupling shown in FIGURE 1 in conjunction with cleaning the screen; and

FIGURE 8 is an isolated side perspective of a cleaning means in accordance with the invention.

The above and other objects of the present invention are, in part, accomplished by a device which comprises a novel arrangement of screen, by which arrangement more. screen surface area is provided, and a process and device for improving a liquid-solid separation in a vibratory screening apparatus by operating the device for its intended purpose until its capacity begins to be reduced by virtue of screen clogging and intermittently applying hot vapors, such as steam, to the screen cloth.

The vibratory separator of this invention generally comprises a housing structure; a first planar screen having an outer periphery secured to the housing structure, and a central discharge opening; a second screen; means for delivering material to be separated to the second screen adjacent its surface; the second screen being positioned above the first screen such that no portion of the second screen is in a plane parallel to the first screen and such that any of the material which does not flow through the second screen is delivered to the first screen at near the periphery thereof; means for vibrating the housing structure and the first screen to cause movement of the material from the outer periphery of the first screen toward the discharge opening for discharge of the oversize component of the material; means under the first screen for receiving the component of the material passing through the first screen; means communicating with the second screen for receiving the components of the material passing through the first screen; and means communicating with the central opening of the first screen to receive the oversize component of the material. In addition to the basic vibratory separator with the second non-planer, non-parallel screen; the present invention, in one of its aspects, makes use of a mechanism for cleaning the screens either while in operation or intermittently between periods of operation.

In a preferred embodiment of the invention, the second screen is a cylindrical screen positioned so that the axis of the cylinder formed by the screen is perpendicular to the center of the first screen. However, any screen configuration in which the second screen is neither parallel to nor in the same plane as the first screen is within the purview of the invention so long as the discharge (i.e., material not passing through) of the second screen is the feed to the first screen. The cylindrical screen is pre ferred because it lends itself to inclusion in a cylindrical housing or frame and provides a maximum surface area per unit of height above the planar screen.

Another aspect of the present invention comprises means for feeding the non-planar second screen in a direction which is not perpendicular to the tangent at the surface of the screen. It has been found that a better separation of oversize and undersize material is obtained in this fashion. By undersize material, as used throughout this specification, is meant either relatively small solid particles either in a liquid or in a solid mixture and the liquid itself in a suspension.

The vibratory shaking or screening device, as shown in FIGURE 1, consists of a base frame on the upper portion of which is mounted a ring of springs 11 which supports the vibratory screening device and isolates the vibrations imparted upon such device from the base frame 10.

A vibratory unit comprising a motor 12 and upper and lower eccentric weights 13 and 14 respectively, is mounted by means of the mounting brackets 15 to a cylindrical extension 16 of the upper base 17 which is supported on the ring of springs 11 and is reinforced by gusset plates 18 which project between the springs 11.

The relationship of the vibratory unit and the base frame 10, as described above, may be varied by other arrangements. For example, a motor may be mounted upon the base frame 10. A belt drive from such motor extends to and rotates the eccentric weights which are mounted on the upper base 17.

On the upper base frame 17 is mounted a cylindrical housing structure or spacing frame 19 having a discharge duct 21 projecting therefrom and communicating with a cylindrical opening 20 in the approximate center through the sloping pan 54.

Secured to the interior of the spacing frame 19 is a sloping receiving pan 22 which is inclined and which is isolated from the interior of the discharge duct 21 by the walls of the opening 20. The pan 22 slopes upwardly from the lower portion of the frame 19 to a point diametrically opposite and adjacent to the upper edge of the frame 19.

At the bottom of the frame 19 is a clamp ring 23 which secures the lower edge of the frame 19 to the upper base 17.

The inner periphery and outer periphery of the horizontal screen 24 are secured to inner and outer tension rings 25 and 26 respectively, thus forming a rigid single unit. As best shown in FIGURE 5, the inner periphery of the horizontal screen 24 is aflixed to marginal tension ring 25 by spot welding, bonding or other suitable means. As shown, the screen 24 is sandwiched between the tension ring 25 and the upper securing ring 55 prior to spot welding at intervals long the inner periphery. Alternatively, if the screen 24 is bonded to the tension ring 25,, the ring 55 is of the bonding medium, such as epoxy cement.

The outer periphery of the horizontal screen 24 rests upon an outer marginal tension ring 26 and is bonded, spot welded or otherwise affixed thereto. The horizontal screen 24 may be tensioned by a number of methods in a simple manner. For example, a single piece of screen material is stretched completely over the outer tension ring 26 and, while stretched, aflixed in a suitable manner to the tension ring 26. The inner tension ring 25 is then secured in place and the screen is cut to provide the center discharge opening. Upon afiixing the screen 24 to tension rings 25 and 26, the screen 24 and tension rings 25 and 26 form a single, rigid and removable unit.

The screen 24, assembled in the tension rings 25 and 26, is placed onto the vibratory separator unit whereby the inner marginal tension ring 25 rests upon and is secured in a suitable manner (such as by bolting) to a flange or lip 33 which projects inwardly from the upper cylindrical opening 20 (see FIGURE 5).

As best shown in FIGURE 3, a flange or lip 33 projects outwardly from the outer margin of tension ring 26, the flange 33 being interposed between spacing frames 19 and 27 and resting upon a flange which projects outwardly from the upper periphery of the spacing frame 19. A clamp ring 28 secures the spacing frames 19 and 27 and the interposed flange 34 of the tension ring 26. In FIGURE 3, the outer tension ring 26 is provided with a series of openings 42, such openings permitting the undersize liquid or other materials which pass through the adjacent vertical collar screen 29 to fall onto the receiving pan 22 and utimately be discharged through the undersize discharge duct 43.

Before the collar screen 29 is assembled onto the unit, the lower periphery of the screen 29, as illustrated in FIGURES l and 3, is bonded, spot welded or otherwise secured to the outer side of the vertical projection of a circular flange 30. The horizontal projection of the circular flange 30, with the screen attached to the outer side of the vertical projection, is attached to the tension ring 26 by inserting bolts 31 through the corresponding holes in the horizontal projection of the flange 30 and tension ring 26, which holes are internally threaded to receive the bolts 36. Alternatively, the holes in the ten sion ring 26 may be drilled completely through the ring 26 and the bolts 36 held with lock nuts.

As shown in FIGURE 6, interposed between the housing sections or spacing frames 27 and 32 is a flange 56 projecting from a circular ring 34. Another ring clamp 35 secures the spacing frames 27 and 32 and cover 34. The upper periphery of the cylindrical collar screen 29 is aflixed by bonding, spot welding or other suitable means to the outer side of the vertical projection of a flange ring 36 in the same manner as was the lower periphery of the screen 29 as previously described. A series of bolts 37, at pre-determined locations circularly upon the horizontal projection of the flange 36, passes through the corresponding holes in the flange 36 and also through the circular ring 34. Tensioning of the collar screen 29 is accomplished by the bolts 37 and tensioning nut 38 at the upper end of the bolt.

The spacing frame 27 is equipped with a feed arrangement consisting of a feed pipe 39 which enters the periphery of the spacing frame 27 in a generally tangential fashion and is connected to and projects through the collar screen 29, the collar screen being provided with an opening at such connection corresponding to the opening of the feed pipe 39.

As best shown in FIGURE 2, the end of the feed pipe 39 consists of a flange 40 projecting outwardly from the feed pipe 39 at an angle which is complimentary to the curvature of the collar screen 29. The collar screen 29 overlies the projecting flange 40 of the feed pipe 39 and is covered by an overlying ring 41. The screen 29 and ring 41 are spot welded or otherwise secured by bonding to the flange 40 which projects from the feed pipe 39.

The vibratory separator functions to separate materials of two different sizes (or liquid from solid) through the screen 24 and the non-planar, nonaparallel collar screen 29, by virtue of the vibratory motion imparted by the vibratory unit, including upper and lower eccentric weights 13 and 14 and the tangential feed arrangement made by which the material to be separated is forcefully projected onto the horizontal screen 24 and against its adjacent collar screen 29. As the material to be separated is fed onto the screen 24 and against the adjacent screen 29 by reason of the initial force of the tangential feed, the vibratory motion causes the material to move along the screen 24, the oversize portion of the material being discharged through the discharge opening 20. The undersize material which passes through the collar screen 29 falls through the provided openings 42 in the tension ring 26, as best shown in FIGURE 5, onto the receiving pan 22 and is ultimately discharged through the discharge duct 43. Undersize material falling through the screen 24 falls onto the receiving pan 22 and is ultimately discharged through the discharge duct 43.

The collar screen 29, which provides a greater area over which the material to be separated may pass, thereby increasing the capacity of the separator, is particularly useful when a large volume of liquid is to be separated from a relatively small quantity of solids. In such instance, the tangential feed forcefully projects the liquid-solid material onto the screen 24, resulting in a cyclonic movement of the material which causes the material to be forced against the side screen 29. The major volume of liquid passes through the side screen 29 while the remaining volume passes through the horizontal screen 24 and the oversize materials being discharged through the center discharge opening 20.

Although in most instances the additional screen area as provided for by the collar screen 29 substantially increases the capacity of a separator to separate materials, there have been certain applications in which the vibratory screening apparatus has been relatively unsuccessful.

For example, when using the vibrating screen separator to remove a relatively small amount of finely divided solids from a large volume of liquid, the screen cloth has a tendency to become bridged or clogged by the particulate materials. This is particularly true in making a preliminary separation between water and finely divided solids in raw sewage where the sewage contains suspended grease or oil often found in domestic household wastes. In these instances, the semi-solid grease tends to bridge and adhere to the screen cloth and gradually reduces the capacity of the cloth to discharge water.

This problem can be solved by the present invention which comprises a process for improving the operation of a liquid-solid separation in a vibratory screening apparatus by intermittently operating the device for its intended purpose until its capacity begins to be reduced by virtue of screen clogging or bridging, discontinuing operation and removing the bridging or clogging by applying hot vapors such as steam to the screen cloth.

This may be accomplished as illustrated in FIGURE 1 by a rotating stream jet arrangement lying above the screen 24 and parallel to the side collar screen 29. As shown in FIGURE 9, the steam jet arrangement consists of a steam entry line 44 which feeds a rotary coupling 45 which is, in turn, attached to a vertical pipe 46 at the lower end of which are four adjacent extending arms 47. The four lower extending arms 47 are connected to four vertical pipes 48. The steam jets 49, located on the vertical pipes 48 which are connected to the lower extending arms 47, are canted in such a manner that when steam flows through the canted nozzles 49, the reaction pressure from the steam emitted from the canted nozzles 49 causes the assembly, consisting of the four vertical pipes 48, the vertical pipe 46 and the lower extending arms 47 to rotate in the coupling 45 so that the entire surface of the horizontal and vertical collar screen is treated with the steam during application. The fluid flowing in the lines to accomplish the cleaning need not be steam-but may be any suitable solvent which will melt or dissolve the material which causes the screen clogging or bridging. Thus, under certain circumstances, hot water may be employed to effect the desired cleaning.

FIGURE 8 represents a detailed view of the rotary coupling 45 and, by way of illustration, shows the pipe 46 threadably connected to the rotating nipple 51 which is set in the lubricated bearing assembly 52 which is located in the body of the rotary coupling 45 in a manner well known in the art.

It may be observed that the circular cover 34 is provided with a circular opening of sufiicient size to allow the vertical pipe 46 to pass. To assemble the rotary arm steam cleaning unit illustrated in FIGURE 1 onto separator unit, prior to placing the circular cover 34 onto the separator, the steam cleaning unit threadably detached from the rotary couple 45 must first be placed in its proper position, the circular cover subsequently placed in its proper position as previously described.

It is to be noted that the feed pipe 39 must be connected to a flexible connector (not shown) so that its vibrations are isolated from the feed system feeding material to be separated to the device. The feed pipe 39 may be located at any desired elevation along the frame 27. It is also be noted that a plurality of feed pipes positioned around the periphery at various regularly spaced locations can be and are preferably employed. Further, although four steam arms have been illustrated, the steam cleaning apparatus may consist of a single steam arm rotating adjacent to screen 29 or it may comprise two, three, or four individual steam arms so rotating.

It is also to be noted that the screen 29 and screen 24 may be, and in many applications are, of different mesh sizes. Thus for example, when using the upper cylindrical screen 29 to concentrate raw sewage effluent for a small amount of suspended solids, the solids tend to agglomerate while passing downwardly over screen 29 so that a coarser mesh screen may be employed on the horizontal screen 24 than is employed in the vertical collar screen 29.

It is preferred to feed material toward the upper periphery of the collar screen 29 at an angle other than perpendicular to the tangent line of the screen at the point of contact. Thus it is preferred that the material being fed to the collar screen tangentially, or as close to, tangentially as is possible. The feed means may comprise the illustrated feed pipe projecting through the annular frame, or it may be an internal mechanism not communicating with the separator screen itself which flows material against the screen 29.

To illustrate the results obtainable with the device of this invention, it was possible to increase the capacity of a vibratory screen of 48" outside diameter having 105 micron openings by approximately 100 percent by providing the planar screen with a collar screen having identical mesh size.

The device of this invention gave outstanding results when used in the initial or primary clarification of raw sewage containing grease and up to about 440 parts per million total suspended solids of which 70 to percent comprise volatiles.

A device of the character above described having both planar and collar screen receive about 390 gallons per minute of the raw sewage, the feed being through the spacing frame as described above. The apparatus was run intermittently for 15 minute periods, was then stopped for 5 minutes during which steam was applied to collar screen 29 for approximately 3 minutes. In an extended run, the average filtrate concentration (that portion passing through screens 24 and 29) was 194 parts per minute of total solids while the oversize material passing out through the discharge chute contained 56 percent of the initial total solids and had an actual solids concentration of about 5.0 percent with a volatile content of approximately 93 percent. The vibratory separator, according to this invention, operated for extended periods of time as a complete replacement for a primary clarifier in a sewage plant having an average input feed rate of about 390 gallons per minute.

I claim:

1. A vibratory separator comprising a housing structure,

a first planar screen having a central discharge opening and having an outer periphery secured to said housing structure,

a second upstanding screen,

feed means for delivering material to be separated to said second screen adjacent its surface, said feed means provided a tangential feed of material to the inner surface of said second screen,

said second screen being mounted substantially adjacent the periphery of said first screen and above said first screen such that no portion of said second screen is in a plane parallel to said first screen and such that any of said material which does not flow through said second screen is delivered to said first screen at near the periphery thereof,

means for vibrating said housing structure and at least said first screen to cause movement of said material from the outer periphery of said first screen toward said discharge opening for discharge of the oversize component of said material therethrough said means for vibrating including a rotary power source and at least an eccentrically mounted weight coupled therewith,

means under said first screen for receiving the component of said material passing through said first screen,

means communicating with said second screen for receiving the component of said material passing through said second screen, and

means communicating with the central opening of said first screen to receive the oversize component of said material.

2. A vibratory separator comprising a housing structure,

a first planar screen, secured to said housing structure and having a central discharge opening therein,

a second upstanding screen, said second screen being mounted substantially adjacent the periphery of said first screen and extending upwardly above said first screen to enable material fed to said separator which does not flow through said second screen to be delivered to said first screen near the periphery of said first screen,

feed means adjacent said second screen for delivering material to be separated to said second screen adjacent the inner surface thereof, said feed means providing a tangential feed of material to the inner surface of said second screen,

discharge means under said first screen for receiving a component of said material passing through said first screen,

means communicating with said second screen for receiving a component of material passing through said second screen,

discharge means communicating with the central opening in said first screen for receiving an oversize component of said material, and

vibratory means coupled with said housing structure for vibrating said housing structure and at least said first screen to cause movement of said material from the outer periphery of said first screen toward said discharge opening therein for discharge of said oversized component of said material, said vibratory means including a rotary power source and at least an eccentrically mounted weight coupled therewith.

3. A separator as in claim 2 wherein said feed means includes at least one feed pipe extending through said second screen.

4. A separator as in claim 2 wherein said first screen is substantially circular, and

said second screen is substantially cylindrical, said second screen being mounted at the periphery of said first screen.

5. A separator as in claim 4 wherein retaining means is provided for securing said first screen to said housing structure, said retaining means having openings therein for allowing a component of said material passing through said second screen to flow to said discharge means under said first screen.

6. A separator as in claim 4 wherein said feed means includes at least one feed pipe extending through said second screen.

7. A separator as in claim 2 wherein said first screen includes retaining means coupling said first screen to said housing structure,

said second screen is substantially cylindrical, the bottom of said second screen is joined to the first screen near the periphery of said first screen, and

retaining means are coupled between the top of said second screen and said housing structure.

8. A vibratory separator comprising a housing structure,

a screening structure mounted in said housing structure, said screening structure including a first portion which has a central discharge opening therein, and having a second portion upstanding at near the periphery of said first portion such that material fed to said screening structure which does not flow through said second portion is delivered to said first portion near the periphery of said first portion,

feed means extending through said second screen portion for delivering material to be separated tangentially to said second screen portion adjacent the inner surface thereof,

discharge means communicating with said screening structure for receiving components of said material passing through said first and second portions thereof,

discharge means communicating with the central opening in said first portion of said screening structure for receiving an oversize component of said material, and

vibratory means coupled with said housing structure for vibrating said housing structure and at least said first portion of said screening structure to cause movement of said material from the outer periphery of said first portion toward said discharge opening therein for discharge of said oversize component of said material, said means for vibrating including a rotary power source and at least an eccentrically mounted weight coupled therewith.

9. A separator as in claim 8 wherein said feed means includes a feed pipe disposed with respect to said second portion of said screening structure to cause material to be fed substantially tangentially to said second portion of said screening structure.

10. A vibratory separator comprising a housing structure,

a first substantially planar screen secured to said housing structure, said first screen having a central discharge opening therein,

discharge means communicating with said central opening in said first screen for receiving an oversize component of material being screened by said first screen,

vibratory means coupled with said housing structure for vibrating said housing structure and said first screen to cause movement of said material from the outer periphery of said first screen toward said discharge opening therein for discharge of said over size component of said material, said vibratory means including a rotary power source and at least one eccentrically mounted weight,

screen means for receiving material to be screened and for allowing material which does not flow through said screen means to be delivered to said first screen near the periphery of said first screen, said screen means comprising a substantially cylindrical screen coupled with said housing structure and mounted above said first screen, and

feed means adjacent said screen means for delivering said material to be screened to said substantially cylin drical screen adjacent the inner surface thereof, said feed means providing a substantialy tangential feed of material to the inner surface of said substantially cylindrical screen to cause a cyclonic movement of said material toward said substantially planar screen.

11. A separator as in claim 10 wherein said feed means includes at least one feed pipe extending through said substantially cylindrical References Cited UNITED STATES PATENTS Dick 209-273 X Barr 209--12 Mitchell 209-270 X Mjolsness 209-303 X Kowan 209-403 X Plaven 209-306 X Schlatter 209---380 X Carter 209 -370 X Nissen 209-405 X Koziol 209-332 X Simpson 209366.5 X Syluest 209380 X Goodes 209275 X Amon 209 -275 Bartholornai 209-17 X OToole 20 9-275 X La Fave 209-245 X FOREIGN PATENTS Great Britain.

US. Cl. X.R.

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