Sealing system for tank rotary shaft

Patent metadata

Field	Value
Publication number	US-10113645-B2
Application number	US-201415106035-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 19, 2013
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A seal arrangement allowing in-line maintenance and replacement of packing, seals and bushings of a rotary shaft driving a tool extending inside a fluid holding tank. The rotary shaft and associated seals are mounted in an extractable cartridge removably insertable in sealing engagement within a housing projecting outwardly from the tank. A secondary seal comprises an isolation valve mounted to the housing outside of the tank for temporarily providing sealing during servicing of the seals in the extracted cartridge. A tertiary seal is provided for protecting the secondary seal from the tank contents when used in scaling environments. Removable parts of said seal arrangement.

First claim

What is claimed is:

1. A seal arrangement for sealing a rotary shaft and a shaft opening defined in a wall of a tank configured for containing a flowable material, comprising a primary seal mounted with the rotary shaft in an extractable cartridge to provide sealing around the rotary shaft, the seal arrangement further comprising a secondary seal operational for closing the shaft opening when removing the primary seal for maintenance or replacement, characterized in that the extractable cartridge is removably insertable in sealing engagement within a housing projecting outwardly from the tank around the shaft opening, and in that the secondary seal comprises an isolation valve mounted to the housing outside of the tank.

2. The seal arrangement defined in claim 1 , characterized in that the seal arrangement further comprises a tertiary seal provided between the tank and the secondary seal for isolating the secondary seal from the flowable material in the tank during process operations.

3. The seal arrangement defined in claim 2 , characterized in that the tertiary seal is a compression/clamping type seal.

4. The seal arrangement defined in claim 3 , characterized in that the compression/clamping type seal is provided at least in part by a distal end of the extractable cartridge which is held axially in sealing contact against a corresponding sealing face inside the housing when the extractable cartridge is securely fastened to the housing in a fully inserted position therein.

5. The seal arrangement defined in claim 4 , characterized in that in the fully inserted position, the extractable cartridge extends through a passage defined in the isolation valve of the secondary seal, and to the sealing face.

6. The seal arrangement defined in claim 4 , characterized in that the extractable cartridge has a mounting flange at a proximal end thereof, the mounting flange being adapted to be bolted to a corresponding mounting flange of the housing, and wherein bolting of the extractable cartridge to the housing urges the distal end of the extractable cartridge in sealing contact against the sealing face.

7. The seal arrangement defined in claim 4 , characterized in that the distal end of the extractable cartridge includes at least one replaceable sealing member.

8. The seal arrangement defined in claim 1 , further comprising an injection valve operatively connectable to a source of pressurized fluid for selectively pressurizing a gap between the housing and the extractable cartridge.

9. The seal arrangement defined in claim 8 , characterized in that a drain valve is provided on the housing for selectively draining the gap.

10. The seal arrangement defined in claim 1 , characterized in that the isolation valve of the secondary seal is a gate valve including a valve body forming part of the housing and defining a passage extending axially in line with the shaft opening of the tank, a valve member movable in a direction transversal to an axial direction of the passage between a normally open position in which the valve member is retracted to allow the passage of the extractable cartridge through the valve body and a closed position in which the valve member closes the passage defined in the valve body once the extractable cartridge has been sufficiently extracted so as to no longer obstruct movement of the valve member.

11. The seal arrangement defined in claim 1 , characterized in that the rotary shaft has a distal end portion projecting out of the extractable cartridge, a first coupling member being fixedly mounted to the distal end portion for mating engagement with a second coupling member fixed to a tool extending into the tank, the first and second coupling members being axially disengageable.

12. The seal arrangement defined in claim 11 , characterized in that the first and second coupling members have axial splines.

13. The seal arrangement defined in claim 1 , characterized in that the primary seal comprises a pair of rotary seals, and in that the extractable cartridge has a shell defining internal seats for accommodating the rotary seals and bushings.

14. The seal arrangement defined in claim 13 , characterized in that the primary seal further comprises a stuffing box containing packing material compressed around the rotary shaft by a gland follower, the stuffing box being mounted at an outboard end of the extractable cartridge.

15. A set of removable parts of a seal arrangement comprising an extractable cartridge removably insertable in sealing engagement with a housing of a tank, the extractable cartridge comprising a rotary shaft configured for powering a rotary tool and a primary seal mounted with the rotary shaft and providing sealing around the rotary shaft and the extractable cartridge in which the rotary shaft and the primary seal are mounted, wherein the extractable cartridge further comprises a shell partially enclosing the rotary shaft and containing the primary seal, an end cap at a distal end of the extractable cartridge, with the rotary shaft projecting out of the extractable cartridge through the end cap, and a replaceable seal at the distal end of the extractable cartridge, wherein the replaceable seal is configured to be placed in sealing contact with a sealing face of the housing in which the extractable cartridge is received.

16. A seal arrangement for sealing a tank containing a flowable material, comprising:
a tank configured for containing a flowable material, the tank having a wall with an opening extending through the wall;
a housing projecting outwardly from the tank around the opening;
an extractable cartridge that is removably insertable in sealing engagement within the housing, the extractable cartridge comprising a rotary shaft configured for powering a rotary tool through the opening and a primary seal mounted with the rotary shaft to provide sealing around the rotary shaft; and
a secondary seal operational for closing the shaft opening when the extractable cartridge is removed from the sealing engagement within the housing, wherein the secondary seal comprises an isolation valve mounted to the housing outside of the tank.

17. The seal arrangement defined in claim 16 , wherein the isolation valve of the secondary seal is a gate valve including a valve body forming part of the housing and defining a passage extending axially in line with the shaft opening of the tank, a valve member movable in a direction transversal to an axial direction of the passage between a normally open position in which the valve member is retracted to allow the passage of the extractable cartridge through the valve body and a closed position in which the valve member closes the passage defined in the valve body once the extractable cartridge has been sufficiently extracted so as to no longer obstruct movement of the valve member.

18. The seal arrangement defined in claim 16 , wherein the rotary shaft has a distal end portion projecting out of the extractable cartridge, a first coupling member being fixedly mounted to the distal end portion in mating engagement with a second coupling member configured to be fixed to the rotary tool, the first and second coupling members being axially disengageable.

19. The seal arrangement defined in claim 16 , characterized in that the seal arrangement further comprises a tertiary seal provided between the tank and the secondary seal for isolating the secondary seal from the flowable material in the tank during process operations.

20. The seal arrangement defined in claim 16 , characterized in that the pr

Assignees

• Rio Tinto Alcan Int Ltd

Inventors

• Labrum Deane
• Beltrame Dean
• Peloquin Guy
• Boivin Alain

Classifications

• F16J15/008 Primary

  with provision to put out of action at least one sealing; One sealing sealing only on standstill; Emergency or servicing sealings (F16J15/164 takes precedence) · CPC title

• F16J15/3268

  Mounting of sealing rings · CPC title

• F16J15/3248

  provided with casings or supports · CPC title

• B65D90/02

  Wall construction · CPC title

• B65D88/74

  having means for heating, cooling, aerating or other conditioning of contents · CPC title