Separation disc for a centrifugal separator and a method for manufacturing the separation disc

Patent metadata

Field	Value
Publication number	US-9914138-B2
Application number	US-201214235422-A
Country	US
Kind code	B2
Filing date	Aug 7, 2012
Priority date	Aug 10, 2011
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A separation disc for a centrifugal separator and a method for manufacturing the separation disc are disclosed. The separation disc is of metal material and adapted to be compressed in a stack of separation discs inside a centrifugal rotor for separating a liquid mixture. The separation disc has a truncated conical shape with an inner surface and an outer surface and a plurality of spacing members extending a certain height above at least one of the inner surface and the outer surface for providing interspaces between mutually adjacent separation discs in the stack. The spacing members are of such small size that each one of them has a width which is less than 2 mm along the surface of the separation disc. The surface of the separation disc is configured with a distribution pattern of the small-sized spacing members, in such a way as to provide equidistant interspaces in the compressed disc stack.

First claim

The invention claimed is:

1. A stack of separation discs for a centrifugal separator, each separation disc being of metal material and adapted to be compressed in the stack of separation discs inside a centrifugal rotor for separating a liquid mixture, each separation disc comprising:
a truncated conical shape having an exterior surface, an outer perimeter and a central opening, the exterior surface having an inner surface and an outer surface; and
a plurality of spacing members extending a predetermined height above at least one of the inner surface and the outer surface for providing interspaces between mutually adjacent separation discs in the stack,
wherein at least some of the spacing members are small-sized spacing members having a width which is less than 1.5 mm along the exterior surface of the separation disc,
wherein the exterior surface of the separation disc is configured with a distribution pattern of the small-sized spacing members having a distance of less than 60 mm between the small-sized spacing members,
wherein a thickness of the separation disc is less than 0.6 mm,
wherein the predetermined height of the spacing members is equal to a space between the separation discs in the stack, and
wherein the plurality of spacing members includes:
a first ring of the small-sized spacing members around the outer perimeter of the separation disc;
a second ring having the small-sized spacing members and large-sized spacing members which are larger than the small-sized spacing members, the second ring spaced radially inwardly from the first ring; and
a plurality of the small-sized spacing members between the second ring and the central opening.

2. The stack of separation discs according to claim 1 , wherein the small-sized spacing members are spot-formed, and a width of the small-sized spacing members corresponds to a diameter of the small-sized spacing members.

3. The stack of separation discs according to claim 1 , wherein the small-sized spacing members are integrally formed in one piece with the metal material of the separation disc.

4. The stack of separation discs according to claim 3 , wherein a width of the large-sized spacing members is greater than a width of the small-sized spacing members.

5. The stack of separation discs according to claim 4 , wherein the large-sized spacing members are provided in the form of separate pieces of narrow strips or circular blanks of sheet metal, which are attached to the exterior surface of the separation disc.

6. The stack of separation discs according to claim 5 , wherein the large-sized spacing members are attached to the outer surface of the separation disc, and
wherein the small-sized spacing members are formed on the inner surface of the separation disc.

7. A method for manufacturing the stack of separation discs according to claim 3 , comprising the step of:
flow forming the separation disc from a metal sheet with a roller and a mandrel, the roller forming the separation disc over the mandrel comprising a truncated conical support surface with recesses corresponding to the small-sized spacing members, the mandrel having a distribution pattern of said recesses to form the small-sized spacing members in one piece with the separation disc in such a way as to provide equidistant interspaces in the compressed stack of separation discs.

8. The method according to claim 7 , wherein the large-sized spacing members are also flow formed by the roller forming the separation disc over the mandrel comprising recesses corresponding to the large-sized spacing members, whereby both the small-sized spacing members and the large-sized spacing members are integrally formed in one piece with the separation disc.

9. The method according to claim 7 , wherein the small-sized spacing members are flow formed on the inner surface of the separation disc, and the large-sized spacing members in the form of separate pieces of narrow strips or circular blanks of sheet metal are attached to the outer surface of the separation disc.

10. The stack of separation discs according to claim 1 , wherein an outer diameter of the separation disc is at least 120 mm.

11. The stack of separation discs according to claim 1 , wherein the width of the small-sized spacing members is between 0.5 mm and 1 mm.

12. The stack of separation discs according to claim 1 , wherein an outer diameter of the separation disc is at least 200 mm.

13. The stack of separation discs according to claim 1 , wherein the distance between the small-sized spacing members is greater than 10 mm.

14. The stack of separation discs according to claim 1 , wherein the predetermined height is 0.3 to 0.8 mm.

15. The stack of separation discs according to claim 1 , wherein the large sized spacing members are an elongate shape having a length greater than a width, and
wherein an elongate side extending in a direction of the length of the large-sized spacing members extends in a circumferential direction of the separation disc.

16. The stack of separation discs according to claim 1 , further comprising distribution holes between the second ring and the plurality of the small-sized spacing members.

17. The stack of separation discs according to claim 1 , wherein the small-sized spacing members and the large-sized spacing members alternate in the second ring.

18. The stack of separation discs according to claim 1 , wherein both the small-sized spacing members and the large-sized spacing members are integrally formed in one piece with the separation disc.

19. The stack of separation discs according to claim 1 , wherein both the small-sized spacing members and the large-sized spacing members are integrally formed in the inner surface of the separation disc.

20. A liquid separator, comprising:
a housing;
an inlet and an outlet in the housing;
a rotor in the housing; and
a stack of separation discs attached to the rotor, each separation disc comprising:
a truncated conical shape with an exterior surface, an outer perimeter and a central opening, the exterior surface having an inner surface and an outer surface; and
a plurality of spacing members extending a predetermined height above at least one of the inner surface and the outer surface for providing interspaces between mutually adjacent separation discs in the stack,
wherein at least some of the spacing members are small-sized spacing members having a width which is less than 1.5 mm along the exterior surface of the separation disc,
wherein the exterior surface of the separation disc is configured with a distribution pattern of the small-sized spacing members having a distance of less than 60 mm between the small-sized spacing members,
wherein a thickness of the separation disc is less than 0.6 mm,
wherein the predetermined height of the spacing members is equal to a space between the separation discs in the stack, and
wherein the plurality of spacing members includes:
a first ring of the small-sized spacing members around the outer perimeter of the separation disc;
a second ring having the small-sized spacing members and large-sized spacing members which are larger than the small-sized spacing members, the second ring spaced radially inwardly from the first ring; and
a plurality of the small-sized spacing members between the second ring and the central opening.

21. The liquid separator according to claim 20 , wherein the distance between the small-sized spacing members is greater than 10 mm.

22. The liquid separator accordin

Assignees

• Nilsson Sven Åke
• Thorwid Peter
• Alfa Laval Corp Ab

Inventors

• Nilsson Sven-Åke
• Thorwid Peter

Classifications

• B04B1/08

  of conical shape · CPC title

• B04B7/14 Primary

  for separating walls of conical shape · CPC title

• B21D22/16

  over shaping mandrels or formers · CPC title