Screen basket having a removable and replaceable cylindrical mesh liner

• US 5,968,357 A
• Filed: 08/27/1998
• Issued: 10/19/1999
• Est. Priority Date: 08/27/1998
• Status: Expired due to Fees

• Current Assignee: Voith Sulzer Paper Technology North America, Inc.
• Original Assignee: Voith Sulzer Paper Technology North America, Inc.
• Inventors: Doelle, Klaus, Lorenz, Kurt W.
• Primary Examiner(s): Walker, W. L.
• Assistant Examiner(s): SCHWARTZ, AARON L
• Application Number:
  US09/141,247
• Time in Patent Office: 418 Days
• Field of Search: 210/232, 210/403, 210/483, 210/484, 210/485, 210/497.01, 210/402, 210/217, 210/499, 210/415, 209/270, 209/404, 209/406, 209/306, 55/510, 55/496, 162/251, 162/272, 162/274, 29/896.6, 29/896.62, 29/902
• US Class Current: 210/485
• CPC Class Codes: B01D 29/111 Making filtering elements
• CPC Class Codes: B01D 29/23 arranged for outward flow filtration
• CPC Class Codes: B01D 29/54 arranged concentrically or coaxially
• CPC Class Codes: B01D 29/96 in which the filtering elements are moved between filtering operations; Particular measures for removing or replacing the filtering elements; Transport systems for filters B01D29/09, B01D29/70 take precedence
• CPC Class Codes: D21D 5/16 Cylinders and plates for screens
• CPC Class Codes: Y10S 29/902 Filter making
• CPC Class Codes: Y10T 29/496 Multiperforated metal article making

Abstract

A screen basket for filtering an aqueous fiber suspension includes a cylindrical foraminous filter element, anchoring collars surrounding and fixed to opposite ends of the filter element, at least two support rings surrounding the filter element, and support rods for adjusting the support rings between axially contracted positions disengaged from the anchoring collars, and axially expanded positions engaging the anchoring collars and axially tensioning the filter element. In a first embodiment, the anchoring collars are relatively flexible. This allows the anchoring collars to be deformed for insertion of the cylindrical foraminous filter element within the support rings. Alternatively, the upper and lower support rings are divided into segments that are easily disassembled and reassembled to facilitate removal of a defective cylindrical foraminous filter element and installation of a new filter element. Advantageously, the screen basket includes a reusable rigid frame that cooperates with a replaceable and disposable cylindrical foraminous filter element.

Claims

1. A screen basket for filtering an aqueous fiber suspension, comprising:

an upper support ring having an upper circular anchor channel and a plurality of circumferentially spaced upper threaded apertures;

a lower support ring having a lower circular anchor channel and a plurality of circumferentially spaced lower threaded apertures each of which is aligned coaxially with an associated one of said upper threaded apertures;

a cylindrical mesh liner having an upper anchor engaged with said upper circular anchor channel and a lower anchor engaged with said lower circular anchor channel; and

a plurality of support rods extending between said support rings, each of said support rods having oppositely threaded ends engaged respectively in said upper and lower threaded apertures, said support rods extending between said support rings to engage said anchors to said channels upon rotation in one direction, and disengage said anchors from said anchor channels upon rotation in an opposite direction.

2. The screen basket of claim 1, wherein said upper and lower anchors are flexible.

3. The screen basket of claim 1, wherein said upper and lower support rings are divisible into semicircular segments.

4. The screen basket of claim 3, wherein said upper and lower anchors are rigid.

5. The screen basket of claim 3, further comprising a ring clamp that surrounds said upper support ring.

6. The screen basket of claim 3, wherein the locations at which said semicircular segments at which said upper and lower support rings are joined are annularly offset by 90°

.

7. The screen basket of claim 1, wherein said upper support ring includes a plurality of upper segments, and said lower support ring includes a plurality of lower segments.

8. The screen basket of claim 1, further comprising an intermediate support ring located between said upper and lower support rings and having a plurality of circumferentially arranged middle apertures each uniquely associated with one of said upper threaded apertures and one of said lower threaded apertures, such that each of said support rods passes through an associated one of said middle apertures.

9. The screen basket of claim 8, wherein said intermediate support ring includes a facing wall to which said cylindrical mesh is attached by welding.

10. The screen basket of claim 1, wherein said upper and lower anchors are U-shaped.

11. The screen basket of claim 1, wherein each of said support rods includes a wrench head which facilitates rod rotation.

12. The screen basket of claim 1, wherein said cylindrical mesh liner includes staggered rods interspersed within meshing of said cylindrical mesh liner.

13. The screen basket of claim 12, wherein said staggered rods are about several inches long and brazed to said meshing.

14. The screen basket of claim 1, further comprising a mounting flange attached to an axial outer surface of said upper support ring.

15. The screen basket of claim 1, further comprising a circular clamp which is attached to and abuts against an axial outer surface of said lower support ring.

16. A screen basket for removing contaminants from an aqueous papermaking stock, said screen basket comprising:

an upper support ring that includes an upper circular anchor channel and a plurality of circumferentially arranged longitudinal upper threaded apertures;

a lower support ring that includes a lower circular anchor channel and a plurality of circumferentially arranged longitudinal lower threaded apertures each of which is coaxial with an associated one of said plurality of longitudinal upper threaded apertures;

a support ring having a plurality of circumferentially arranged middle apertures each uniquely associated with one of said upper threaded apertures and one of said lower threaded apertures;

a removable and replaceable cylindrical mesh liner having an upper anchor that engageably seats in said upper circular anchor channel and a lower anchor that engageably seats in said lower circular anchor channel; and

a plurality of support rods each of which passes through an associated one of said longitudinal lower and upper threaded apertures and said middle apertures, wherein each rod includes first and second threaded ends that are oppositely threaded, said support rods extending between said support rings to engage said anchors to said channels upon rotation in one direction, and disengage said anchors from said anchor channels upon rotation in an opposite direction.