Rotary kinetic fluid motors or pumps – Bearing – seal – or liner between runner portion and static part – Dynamically created seal
Patent
1995-09-08
1997-03-11
Kwon, John T.
Rotary kinetic fluid motors or pumps
Bearing, seal, or liner between runner portion and static part
Dynamically created seal
416223B, 416DIG2, F01D 500
Patent
active
056094680
DESCRIPTION:
BRIEF SUMMARY
This invention relates to centrifugal seal assemblies suitable for use in centrifugal pumps and more particularly to a seal assembly for the pump shaft.
A typical pump assembly and associated seal assembly is shown in the drawings in which:
FIG. 1 is a schematic side elevation of a pump and centrifugal seal assembly, the centrifugal seal assembly being in accordance with a preferred embodiment of the invention;
FIG. 2 is a plan view of a seal device for use in the seal assembly; and
FIG. 3 is a sectional side elevation of the device shown in FIG. 2.
Referring to the drawings there is shown a pump generally indicated at 10 comprising a pump casing 12 with a pump chamber 14 therein. The pump 10 further includes a pump impeller 18 having an impeller passageway 20, the impeller 18 being mounted for rotation on pump shaft 16 and disposed within pump chamber 14.
To one side of the pump casing 12 is a centrifugal seal assembly 30 which includes a rotatable seal device 31. The seal device 31 comprises a main body 32 having an inner section 34 which is mounted to the pump shaft 16 and an outer section 36 which in the form shown is disc-like in structure. The device 31 is mounted to the pump shaft 16 for rotation therewith. The seal device 31 is disposed within a seal chamber 42 which is in communication with the pump chamber 14 via passageway 43.
The seal device 31 includes a plurality of vanes 38 which extend from the inner section 34 of the main body 31 and terminate at the outer peripheral edge of the outer section 36. The vanes 38 are spaced apart from one another in the circumferential direction and include a curved leading edge with respect to the direction of rotation of the device.
The centrifugal seal assembly 30 is used in conjunction with a main seal apparatus 46 which may be in the form of packings, as shown, or lip seals or other types of seals.
Shaft seal assemblies of this general type for centrifugal pumps are known. The rotating seal device generates a dynamic pressure at its periphery. During rotation liquid within the seal chamber is forced to rotate with the device. This pressure helps to counter balance the pressure generated from the pump impeller. The reduced pressure at the pump shaft permits the main seal apparatus to function as low pressure seal and thereby improve the seal life. The purpose of the main shaft seal is to prevent leakage when the pump has stopped.
Properly applied centrifugal seal assemblies can generate sufficient pressure to totally counter balance the pump pressure. In this situation the pumped fluid will remain clear of the pump shaft and the main shaft seal apparatus can run "dry" under these ideal conditions. To provide cooling and lubrication it is necessary to use some type of lubrication which may be in the form of grease or water from some external source.
In operation the rotating seal device generates a rotating fluid field in the seal chamber. To maximise the pressure generated various options are available. For example, by increasing the outer diameter of the device, the pressure can be increased according to the square of the speed of rotation.
Furthermore, it has been found that the width of the seal device has less of an influence on performance but generally should be relatively narrow. The shape of the seal device's vanes has been found to be particularly important in maximising pressure and minimising slip and turbulance. Slip will reduce the pressure generated while turbulance in a slurry containing particles will cause wear and reduce component life.
An object of the present invention is to provide an improved seal device and seal assembly incorporating such a device which improves the performance of the device and assembly.
Basically, the invention relates to a centrifugal seal device suitable for use with a pump which comprises a pump casing having a pump chamber therein and a pump impeller with an impeller passageway, the pump impeller being mounted on a rotatable shaft, the pump impeller being disposed within the pump chamber.
The seal device inclu
REFERENCES:
patent: 1932214 (1933-10-01), Hornschuch
patent: 2764945 (1956-10-01), Heep
patent: 4884945 (1989-12-01), Boutin et al.
patent: 4915579 (1990-04-01), Whittier et al.
patent: 5261786 (1993-11-01), Sidelko
patent: 5393199 (1995-02-01), Alizadeh
Kwon John T.
Warman International Limited
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