WO2007031859A1

WO2007031859A1 - Distribution member

Info

Publication number: WO2007031859A1
Application number: PCT/IB2006/002552
Authority: WO
Inventors: Leon Smith
Original assignee: Tongaat Hulett Limited
Priority date: 2005-09-16
Filing date: 2006-09-15
Publication date: 2007-03-22

Abstract

A distribution member includes a plurality of distribution chambers located between a stator and a rotor, with sealing arrangements being provided between each distribution chamber, each sealing arrangement including a partition associated with the stator and having opposed sealing surfaces, a seal housing associated with the rotor and straddling the partition, the seal housing containing at least two ring seals each having a sealing surface abutting one of the opposed sealing surfaces of the partition so that when the rotor rotates about the stator, the ring seals rotate relative to the sealing surfaces of the partition and seal adjacent distribution chambers from one another.

Description

DISTRIBUTION MEMBER

FIELD OF THE INVENTION

This invention relates to a distribution member for a rotary distribution assembly.

BACKGROUND TO THE INVENTION

WO 2004/029490 describes a rotary distribution apparatus. This apparatus includes a distribution member. It is the object of this invention to provide an improved distribution member.

SUMMARY OF THE INVENTION

According to the invention a distribution member includes a plurality of distribution chambers located between a stator and a rotor, with sealing arrangements being provided between each distribution chamber, each sealing arrangement including a partition associated with the stator and having opposed sealing surfaces, a seal housing associated with the rotor and straddling the partition, the seal housing containing at least two ring seals each having a sealing surface abutting one of the opposed sealing surfaces of the partition so that when the rotor rotates about the stator, the ring seals rotate relative to the sealing surfaces of the partition and seal adjacent distribution chambers from one another.

The seal housing may include means for urging the ring seals into contact with respective sealing surfaces of the partition.

The means may comprise a pressure chamber associated with each sealing ring so that fluid under pressure in the pressure chamber can exert a force on the sealing ring to urge the sealing ring into sealing contact with its sealing surface. A pressure chamber seal may be provided on either side of each sealing ring.

An inlet to each pressure chamber is preferably provided in the rotor.

The seal housing may include an anti-leakage pressure chamber for preventing or at least reducing any leakage from the distribution chambers between the sealing rings and their respective sealing surfaces on the partition, the anti- leakage pressure chamber in use being pressurised with a fluid at a higher pressure than the pressure of the fluid in each of the adjacent distribution chambers so that if there is a leak between either of the seal rings and their sealing surfaces, fluid from the anti-leakage pressure chamber will leak into one or both of the adjacent distribution chambers.

An inlet to the anti-leakage pressure chamber is preferably provided in the rotor.

The anti-leakage pressure chamber preferably straddles the free end of the partition.

Securing means for securing the ring seals to the seal housing to ensure that in use the ring seals rotate in unison with the seal housing may be provided.

The securing means comprise elongate members extending from the seal housing into the respective seals.

The securing means may be pins.

Each ring seal may include a plurality of circumferentially spaced holes in its surface remote from its sealing surface into which holes the elongate members extend.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a plan view of a distribution member according to the invention; Figure 2 is a cross-sectional side view on line II - II of figure 1 ;

Figure 3 is a cross-sectional plan view on distribution line III - III of the distribution member;

Figure 4 is a cross-sectional side view on line IV - IV of figure 3;

Figure 5 is an enlarged view of the circled portion of figure 2 marked V;

Figure 6 is an enlarged view of the circled portion of figure 5 marked VI₁ and

Figure 7 is perspective view of figure 6.

DETAILED DESCRIPTION OF THE DRAWINGS

A distribution member 10 includes twelve distribution chambers 12.1 to 12.12 located between a stator 14 and a rotor 16. Sealing arrangements 18 are located between adjacent distribution chambers. Sealing arrangements 18 are also located between the bottom and top distribution chambers 12.1 and 12.12, and the bottom 20 and the top 22 respectively of the distribution member 10.

The stator 14 is hollow. Feed conduits 24 extend downwardly into the stator 14 and are respectively connected to the distribution chambers 12.1 to 12.12. Distribution conduits 26 are connected to the rotor 16 to distribute liquid from the respective distribution chambers 12.1 to 12.12.

The stator 14 and the rotor 16 are each made up of a series of segments 14.1 and 16.1. The segments are held together by draw bars or bolts 28.

The rotor 16 is connected to a rotor (not shown) of an indexing arrangement (also not shown). A motor (also not shown) rotates the rotor of the indexing arrangement which in turn rotates the rotor 16. Likewise the stator 14 is connected to a stator (also not shown) of the indexing arrangement.

Referring now to figures 3 to 6, each sealing arrangement 18 includes a partition 30 fixed to the stator 14. The partition 30 has opposed polished sealing surfaces 32. As can be seen from figure 3, the partition 30 is in the shape of a ring.

Referring particularly now to figure 6, a seal housing 34, which forms part of the rotor 16 straddles the sealing surfaces 32. The seal housing 34 consists of two seal housing sections 36.1 and 36.2. Each seal housing section 36.1 and 36.2 contains a ring seal 38. Each ring seal 38 has a face 40 which abuts a sealing surface 32 of the partition 30. Each ring seal 38 has circumferentially spaced holes 56 in its surface 58 for driving pins 60. The driving pins 60 extend through holes 62 in the seal housing sections 36.1 and 36.2 thereby to secure the ring seals 38 to the seal housing sections 36.1 and 36.2. This ensures that the ring seals rotate in unison with the seal housing 34.

Pressure chambers 42 have inlets 44. O-rings 46 seal against inner and outer sides 48 and 50 respectively of the seal rings 38 to seal the pressure chambers 42.

An anti-leakage pressure chamber 52 has an inlet 54. O-rings 46 seal against the outer side 50 of the seal rings 38, and an o-ring 64 forms a seal between the housing sections 36.1 and 36.2 to seal the anti-leakage pressure chamber 52.

In use, the rotor 16 is rotated about the stator 14 whilst air under pressure is introduced into the pressure chambers 42. The pressure of the air exerts a force on the seal rings 38. This force urges the faces 40 of the seal rings 38 into sealing contact with the sealing faces 32 of the partition 30 as the sealing rings 38 rotate relative to the partition 30. At the same time liquid is fed into the anti- leakage pressure chamber 52 through its inlet 54. This liquid is maintained at a pressure higher than that of the pressure of the process liquids in the adjacent distribution chambers 12.3 and 12.4. If there is not a good seal between the sealing rings 38 and the partition 30, then liquid from the anti-leakage pressure chamber 52 will leak into one or both of the distribution chambers 12.3 and 12.4. Because the pressure in the anti-leakage pressure chamber 52 is higher than the pressure of the process liquids in either of the distribution chambers 12.3 and 12.4, the process liquids cannot leak out of their distribution chambers 12.3 and 12.4 and contaminate one another. The liquid in the anti-leakage pressure chamber 52 is chosen to be non-hazardous and to be compatible with the process liquids.

It will be appreciated that many modifications or variations of the invention are possible without departing from the spirit or scope of the invention.

Claims

1. A distribution member including a plurality of distribution chambers located between a stator and a rotor, with sealing arrangements being provided between each distribution chamber, each sealing arrangement including a partition associated with the stator and having opposed sealing surfaces, a seal housing associated with the rotor and straddling the partition, the seal housing containing at least two ring seals each having a sealing surface abutting one of the opposed sealing surfaces of the partition so that when the rotor rotates about the stator, the ring seals rotate relative to the sealing surfaces of the partition and seal adjacent distribution chambers from one another.

2. The distribution member of claim 1 wherein the seal housing includes means for urging the ring seals into contact with respective sealing surfaces of the partition.

3. The distribution member of claim 2 wherein the means comprises a pressure chamber associated with each sealing ring so that fluid under pressure in the pressure chamber can exert a force on the sealing ring to urge the sealing ring into sealing contact with its sealing surface.

4. The distribution member of claim 3 wherein a pressure chamber seal is provided on either side of each sealing ring.

5. The distribution member of any one of claims 3 or 4 including an inlet to each pressure chamber is provided in the rotor.

6. The distribution member of any one of the above claims wherein the seal housing includes an anti-leakage pressure chamber for preventing or at least reducing any leakage from the distribution chambers between the sealing rings and their respective sealing surfaces on the partition, the anti-leakage pressure chamber in use being pressurised with a fluid at a higher pressure than the pressure of the fluid in each of the adjacent distribution chambers so that if there is a leak between either of the seal rings and their sealing surfaces, fluid from the anti-leakage pressure chamber will leak into one or both of the adjacent distribution chambers.

7. The distribution member of claim 6 wherein an inlet to the anti-leakage pressure chamber is provided in the rotor.

8. The distribution member of claim 6 or claim 7 wherein the anti-leakage pressure chamber straddles the free end of the partition.

9. The distribution member of any one of the above claims including securing means for securing the ring seals to the seal housing to ensure that in use the ring seals rotate in unison with the seal housing.

10. The distribution member of claim 9 wherein the securing means comprise elongate members extending from the seal housing into the respective seals.

11. The distribution member of claim 10 wherein the securing means are pins.

12. The distribution member of claim 10 or claim 11 wherein each ring seal includes a plurality of circumferentially spaced holes in its surface remote from its sealing surface into which holes the elongate members extend.