US3726510A

US3726510A - Agitator mounting for drum filters

Info

Publication number: US3726510A
Application number: US00120804A
Authority: US
Inventors: S Davis; M Durrant
Original assignee: Envirotech Corp
Current assignee: Envirotech Corp
Priority date: 1971-03-04
Filing date: 1971-03-04
Publication date: 1973-04-10
Anticipated expiration: 1990-04-10
Also published as: JPS5314997Y2; FI53928C; BR7201241D0; CA974511A; ZA721024B; FR2127662A5; DE2210098A1; JPS52131667U; IT955139B; DE7208048U; GB1331906A; ZM4072A1; FI53928B; ES400366A1

Abstract

An improved agitator mounting for drum filters having agitator pins located below the drum''s center axis has been developed. The improved agitator mounting provides means for driving a submerged, suspended rake-type agitator through a pin and bearing means mounted through the wall of the filter tank. The improved mounting means, which may be completely removed from outside the tank, comprises bearing means mounted externally, a pin seating in said bearing means, said pin secured to the agitator arm by bolts or other means fastened externally, and a drive arm attached to said pin by external means. A boot may also be attached between the agitator arm and the tank wall to house the agitator mounting and provide a liquid seal to prevent liquid contact with the agitator mounting.

Description

[451 Apr. 10, 1973 United States Patent [191 Davis et a].

m 5% mm Tm W mm Lm mm y Sm m We To y NW my w AGITATOR MOUNTING FOR DRUM FILTERS [75] Inventors: Steven S. Davis, Bountiful; Morris F.

Durrant, Centerville, both of Utah Primary Examiner-Robert W. Jenkins Al 73 Assignee: Envirotech Corporation, Salt Lake Ass'smmExamm canto Attorney-Robert R. Finch, Richard F. Bojanowski and William S. Britt City, Utah 221 Filed: Mar. 4, 1971 21 Appl.No.: 120,804

[57] ABSTRACT An improved agitator mounting for drum filters having agitator pins located below the drums center axis has [52] US. Cl. ..................259/l01, 210/383, 210/402,

been developed. The improved agitator mounting pro- 259/DlG- 16, 2 R vides means for driving a submerged, suspended rake- Bolf Bold 0 type agitator through a pin and bearing means [51] Int.

[58] Field of Search......................2l0/327, 331, 402, mounted through the wall of the filter tank. The im- DIG. 16; proved mounting means, which may be completely 287/5206, 53;70/l88, 189,218 removed from outside the tank, comprises bearing means mounted externally, a pin seating in said bearing means, said pin secured to the agitator arm by [56] References Cited bolts or other means fastened externally, and a drive arm attached to said pin by external means. A boot may also be attached between the agitator arm and UNITED STATES PATENTS the tank wall to house the agitator mounting and provide a liquid seal to prevent liquid contact with the agitator mounting.

14 Claims, 6 Drawing Figures xw 13 o 2 mm 1 ll, \u el l xefinaway$ m l /W|.\ W we 21 36 99 NH 96 PATENTE APR 1 0 ma SHEET 2 nr 2 w N E V m Steven 8. Da

ws BY Morris F Durranf FIGS Their Attorney AGITA'IOR MOUNTING FOR DRUM FILTERS BACKGROUND OF THE INVENTION Rake-type agitators have typically been driven in two ways: (1) Above the trunnion mounting with a reciprocating drive rod; and (2) Below the trunnion mounting with a pin drive through the filter wall. The

former system requires a larger tank since the agitator swings on a radius greater than the drum radius. Also, the former system is difficult to use with fully enclosed filters inasmuch as it is difficult to provide a seal about a reciprocating rod passing through the enclosure.

Swinging the agitator through a bin mounted in the tank wall has generally presented corrosion problems because the pin and associated bearing are located below the liquid level of the filter tank. Furthermore, assembly or disassembly of a pin-driven agitator was tedious because of limited internal working space in which to connect or disconnect the agitator arm from the pin.

DESCRIPTION OF THE INVENTION An improved agitator mounting and pin-drive assembly for driving drum filter agitators has been developed. The improved system comprises bearing means which mounts externally on the exterior wall of a filter tank and communicates with an opening in said tank wall, and pin means passing through said bearing means, said pin means engaging an agitator arm on one end and engaging a crank at the other end. Fastening means are provided which pass through the pin means to engage an agitator arm. Disengaging means are also provided which permits complete external disassembly of said improved agitator mounting. A boot-type seal may encompass the bearing means and pin means to seal the bearing surfaces from contact with liquid.

The agitator drive mounting assembly of this invention is advantageous inasmuch as the agitator pivot point is located below the filter drum trunnion thereby permitting use of a smaller filter tank and the whole filter may be enclosed. Furthermore, the pin drive bearing surfaces may be sealed and the whole agitator drive mechanism may be externally assembled or disassembled.

Further understanding of the invention may be facilitated by reference to the attached drawings.

FIG. 1 is a perspective view of a rotary drum filter having an agitator pin-drive mounted below the filter drum trunnion.

FIG. 2 is an expanded perspective view of the agitator drive mounting assembly of FIG. 1.

FIG. 3 is a cross-sectional, elevational view of a multicomponent agitator drive mounting having bolt-type disassembly means.

FIG. 4 is a cross-sectional, elevational view of a mu]- ticomponent agitator drive mounting assembly having a pin-type disassembly means.

FIG. 5 is a perspective view of a flexible boot-type seal for sealing pin-type agitator mounting assemblies.

FIG. 6 is a cross-sectional, elevational view of a boottype seal in sealing placement about a pin-type agitator or mounting assembly.

In FIG. 1 there is illustrated a drum filter of conventional type having a cylindrical drum 10 supported by trunnions 11 and immersed in a semi-cylindrical tank 12 holding a slurry or other liquid-solids media to be filtered. A rake-type agitator of curved cross-section and extending substantially the length of the tank is driven in an oscillating or reciprocating fashion by a pin 14 extending through an end wall of said tank below the filter trunnion. The pin 14 is rotated through an arc of less than 10 depending upon the length of the raketype filter by a crank 15 and drive arm 16 attached eccentrically to a rotary drive mechanism 17 driven by a motor 18.

The rake-type agitator 13 is supported by agitator arms 19 which depend from the pin 14. The rake-type agitator maintains solids in suspension by its pendulumlike motion. Because the drum filter occupies most of the tank volume, there is little space on the interior of the tank for working. Suspending the agitator arms at a point below the filter trunnion permits the agitator to circumscribe an arc of less radius than the radius of the filter drum thereby eliminating the need for a larger holding tank, such as is required when the agitator arms are suspended at a point above the trunnion.

The agitator drive assembly of FIG. 1 is illustrated in FIG. 2 in expanded fashion to facilitate understanding of the relationship and function of the components of the assembly. Bearing means 20 is shown mounted externally to the tank wall 21, said bearing means having a cylindrical sleeve bearing 22 to receive a pin 14 which engages agitator support 24 and crank 15 so as to transmit motion from the crank to the agitator support 24. The pin has a protrusion on each end to engage a recessed area in the agitator support 24 and the crank to provide positive drive means without placing any stress on the fastening means which holds the assembly together. Alternatively, the pin can be slotted with tongues protruding from the agitator support and crank.

' The protuberance or tongue 26 engages a slot or recess 27 in the face of the agitator support 24. The tongue 26 may be tapered slightly so that it is smaller at its extremity than it is at the base to facilitate mating of the tongue 26 with the recess 27 which may have similarly tapered surfaces. The mating surface 28 of the agitator arm which mates with the tongue 26 of the pin 14 is angled slightly away from the pin 14 to accommodate ease of insertion of the tongue 26. I

The pin 14 is joined with the agitator support by

bolts

29 and 30 which thread into the recess 27 on the agitator support. The crank 15 is secured to the pin 14 by

bolts

31 and 32 which thread into the pin 14. Bolt 33 is a jack screw which is tightened during assembly only with sufficient force to cause it merely to contact the base of recess 27 of the agitator support. Jack screw 34 threads through the crank 15 and butts against the head of bolt 33. Since pin 14 effects a tongue and groove fit with crank 15 by means of the protrusion 35 fitting into the slot or keyway 36 it is possible for the pin 14 and crank 15 to become wedged together even when

screws

31 and 32 are removed. The crank 15 is readily separated from pin 14 by tightening of jack screw 34 which forces the crank 15 away from the pin 14. In a similar fashion, the tightening of jack screw 33 separates the pin 14 and agitator support 24 once the

retaining bolts

29 and 30 are removed. The whole assembly may be disassembled externally inasmuch as the bearing assembly 20 is secured to the exterior of the tank by

stud bolts

37 and 38 and another pair of stud bolts not illustrated.

FIG. 3 illustrates in cross-section another arrangement for securing the crank to the agitator support 24 in a manner to enable the whole mechanism to be disassembled externally. A single holding bolt 41 extends through the crank 15 and the pin 42 into a threaded hole in the agitator support 24. In assembling the mechanism, the pin 42 is mated with the agitator support 24 so that the protrusion 43 of the pin fits into the slot 27 of the agitator support. The crank is then mated to the pin 42 in a similar fashion and the-single retaining bolt 41 fastened into the agitator support 24 to hold the assembly together. For disassembly, the single bolt 41 is removed and jack screw 45 is threaded through the pin 42 to butt against agitator support 24. Further tightening of the jack screw 45 separates the pin 42 from the agitator support 24. Jack screw 45 is 1 not threaded into crank 15 but is preferably removed prior to tightening of jack screw 46 which is used to separate the crank 15 and pin 42. The pin 42 of FIG. 3 differs from pin 15 of FIG. 2 in the number of bolt holes passing therethrough.

In FIG. 4 a slightly different arrangement than illustrated in FIG. 3 is presented. The assembly, shown-in cross-section, comprises a crank 15, a connecting pin 48, an agitator support 24 and a single, centrally located bolt 50 which threads into the crank 15 and the agitator support 24 to hold together the whole assembly. The mechanism is disassembled by removing bolt 50 and tightening jack screw 51 which, through rod 52, puts pressure on the agitator support. During this operation the crank 15 and pin 48 are held together by bolt. 53. The crank 15 and pin 48 are separated by removing bolt 53 and further tightening jack screw 51 which is threaded into the crank until the jack screw places pressure on the butt surface 54 of the pin to separate the crank and pin. The diameter of jack screw 51 is greater than that of rod 52 or the passageway containing rod 52. The pin 48 differs from the pins illustrated in FIG. 2 and 3 in the number and arrangement of bolt holes present.

A boot for sealing the bearing surfaces of the agitator drive assembly from liquid is illustrated in FIGS. 5 and 6. The boot 80 is cylindrical in shape with a lip 55 attached to cylinder 56 which has a base 57 with a slotlike hole 58 which accommodates the tongue or protrusion of a shaft for mating with a slot of an agitator arm. The boot is preferably of rubber or similar flexible material which will accept a twisting action of about less than ten degrees. The cooperation of the boot of FIG. 5 with a typical pin-drive assembly of this invention is illustrated in FIG. 6 wherein the boot 80 is illustrated in cross-section. The boot lip 55 is external to a tank wall 21 and placed between the flange portion of bearing means and the tank wall 21 so that when the flange is tightened against the tank wall 21 a sealing effect will be accomplished. A pin 14 having a protrusion or tongue 26 projecting through the slot 58 of the boot 80 mates with a keyway or slot 27 of the agitator support 24. Upon tightening of the bolts which secure the pin 14 to the agitatorsupport 24 a seal is effected about the boot 80 so that no liquid can seap into the bearing surfaces existing between pin 14 and cylindrical sleeve 22. A boot of this type is preferred in the instant invention inasmuch as the whole assembly may be disassembled externally and the boot itself may be removed from a position outside of the tank.

Other types of boots may be utilized, for example, a sleeve-type boot may be utilized wherein one end of an open cylindrical sleeve may be slipped over the cylindrical portion of the agitator arm protrusion and tightened thereto with a ring-clamp. The other open portion of the sleeve may be slipped over the cylindrical protrusion of the bearing and secured thereto with a ring-clamp.

Although the instant invention has been described hereinabove with reference to specific embodiments, it is to be understood that the invention is not to be limited solely thereto but to include all the variations and modifications falling within the scope of the appended claims.

We claim:

1 An agitator drive assembly for mounting below the trunnions of drum-type filters at least partially enclosed by a filter tank, said assembly comprising:

a. bearing means mounted against an exterior wall of said filter tank and communicating with an opening in said tank wall,

. removable pin means passing through said bearing means, said pin means adapted to engage an agitator support,

. removable fastening means extending through said pin means securing said pin means to said agitator support,

means for externally driving said pin means, and

external means for disengaging said pin means from said agitator support.

2. The agitator drive assembly of claim 1 wherein said bearing means has a cylindrical interior bearing surface.

3. The agitator drive assembly of claim 1 wherein said pin means engages the agitator support in driving fashion.

4. The agitator drive assembly of claim 1 wherein said fastening means comprises at least one bolt passing through said pin means to engage'a threaded opening in said agitator support.

5. The agitator drive assembly of claim 1 wherein said means for driving said pin means comprises a crank arm, the free end of said crank arm being reciprocally driven to describe an arc in its travel.

6. The agitator drive assembly of claim 5 wherein said crank arm is secured to said pin means by removable fastening means.

7. The agitator drive assembly of claim 6 wherein 'extemal disengaging means is adapted to disengage said crank arm from said pin means.

8. The agitator drive assembly of claim 6 wherein said fastening means comprises at least one bolt passing through said crank arm and said pin means to engage a threaded opening in said agitator support.

9. The agitator drive assembly of claim 6 wherein said fastening means includes a second bolt which secures said crank arm only to said pin means and a single disengaging means for disengaging said pin means from said agitator support and for disengaging said crank arm from said pin means.

10. The agitator drive assembly of claim 9 wherein said single disengaging means comprises at least one jack screw engaging threads only in said crank arm and engaging a rod which passes through a bore hole in said pin means and is slightly longer than said pin means and wherein said jack screw has a greater diameter than the bore hole of said pin means.

port and encompasses at least a portion of the bearing member protruding into said tank to prevent liquid from contacting the bearing surfaces of'said pin and bearing.

14. The agitator drive assembly of claim 13 wherein the flexible boot-like seal possesses a lip at its open end which is adapted to contact the exterior wall of said tank in a sealing fashion.

Claims

1. An agitator drive assembly for mounting below the trunnions of drum-type filters at least partially enclosed by a filter tank, said assembly comprising: a. bearing means mounted against an exterior wall of said filter tank and communicating with an opening in said tank wall, b. removable pin means passing through said bearing means, said pin means adapted to engage an agitator support, c. removable fastening means extending through said pin means securing said pin means to said agitator support, d. means for externally driving said pin means, and e. external means for disengaging said pin means from said agitator support.

4. The agitator drive assembly of claim 1 wherein said fastening means comprises at least one bolt passing through said pin means to engage a threaded opening in said agitator support.

7. The agitator drive assembly of claim 6 wherein external disengaging means is adapted to disengage said crank arm from said pin means.

11. The agitator drive assembly of claim 1 wherein said means for disengaging said pin means comprises at least one jack screw for engaging threads in said pin means and passing through said pin means to butt against said agitator support.

12. The agitator drive assembly of claim 1 wherein said bearing means protrudes through said opening in said tank wall.

13. The agitator drive assembly of claim 1 wherein a flexible boot-like seal is attached to the agitator support and encompasses at least a portion of the bearing member protruding into said tank to prevent liquid from contacting the bearing surfaces of said pin and bearing.