WO1993021444A1

WO1993021444A1 - Fluid intensifier

Info

Publication number: WO1993021444A1
Application number: PCT/AU1993/000169
Authority: WO
Inventors: Philip Andrew Cooke
Original assignee: Philip Andrew Cooke
Priority date: 1992-04-15
Filing date: 1993-04-15
Publication date: 1993-10-28

Abstract

A fluid intensifier (P) comprises a two stage piston (1) within a sleeve (2). Piston (1) provides, by pressure multiplication, a pressure increase to buffer fluid within the intensifier (P). Sleeve (2) is located within an outer sleeve (3) by end plates (4, 5) with the space therebetween serving as a fluid reservoir. A bleed hole (9) passes through sleeve (2) to the reservoir. A discharge pipe (17) of a pump (18) has a fitting (19) allowing fluid to enter the intensifier (P). Buffer fluid from the intensifier (P) flows through a pipe (21) attached to the seal chamber of pump (18). The fluid returns to the intensifier (P) via a pipe (22).

Description

FLUID INTENSIFIER

Technical Field

This invention relates to improvements for the mechanical sealing of shafts for; pumps, fans and compressors, through the use of a buffer fluid system.

Background Art

Leaking pump shaft seals cause problems for worker safety, the environment, plant and equipment, as well as the costs associated with lost production and the wastage of valuable fluids.

There are many buffer fluid systems available, but these rely on a source of external power, such as electricity or nitrogen gas. For example, one previous device connects the pump sealing chamber to a separate pump to supply the necessary pressure. These proposals have the disadvantage that they require constant maintenance, consume valuable power resources and are unable to respond instantly to pressure fluctuations.

SUBSTITUTE SHEET Disclosure of Invention

These problems are overcome by the present invention, which provides a pressurised buffer fluid to the mechanical seal that can automatically adjust to suit any pressure variances. This invention, comprises a two stage piston with a fixed ratio surface area, sliding axially within a sleeve having a stepped internal diameter, one end of which is pressurised by the pumped product, the other end providing a higher pressure to the mechanical seals. The sleeve is fitted into end plates at each end thereof, one end being being connected by fittings to the pump seal chamber and the other attached to the pump discharge pipe. An outer sleeve is fitted within the end plates.

In one form of the invention, the Pressure Multiplication System is attached to the discharge pipe of the pump and supported by means of a suitable bracket. Pipes are connected between the sealing chamber of the pump and the Pressure Multiplication System to enable the free flow of the buffer fluid.

Devices can be fitted to indicate low fluid level. and can also activate automatic refill units to replenish the supply of buffer fluid.

. SUBSTSTUTE SHEET In another form of the invention, the Pressure Multiplication System is fitted with a quick release bayonet fitting on one end plate via a special adaptor plate, seal and wave spring, for ease of mounting and adaptation to different pipe flange styles and sizes.

The piston may be made of any material compatible with the pumped product, such as teflon or stainless steel.

The other components of the Pressure Multiplication System may be made of any similarly suitable material.

To assist with understanding the invention, reference will now be made to the accompanying drawings which show one example of the invention.

Brief Description of Drawings

FIG. 1 shows an example of the Pressure Multiplication System according to this invention;

FIG. 2 shows the application of such a Pressure Multiplication System to a centrifugal pump;

j SUBSTITUTE SHEET

Claims

Best Mode for carrying Out the InventionReferring to FIG. 1 it can be seen that the PressureMultiplication System (P), according to this invention comprises of an inner sleeve (2) with two separate internal diameters (2a, 2b) and with a bleed hole (9) drilled perpendicular to it's vertical axis, an outer sleeve (3) incorporating threaded blind holes (10) for mounting screws fitted though the end plates (4, 5) which are attached at each end thereof. One end plate (5) has two tapped fittings (11, 12) for pipe connections and is sealed onto the outer sleeve (3) via an o-ring seal (13). The other end plate (4) has a similar o-ring (13) but also incorporates an o-ring seal (14) for the inner sleeve (2) which fits part way through an internal bore (15) located through the axis. Flange mounting studs (6) are fitted via drilled and tapped holes to suit the relevant pipe flange dimensions. Sealing to the flange is via a gasket or o-ring seal.A two stage piston (1) is fitted to the inner sleeve (2) and sealed on it's circumference by two dynamic seals (16).SUBSTITUTE SH HEEEETT FIG. 2 Shows the Pressure Multiplication System in operation. It can be seen that the discharge pipe (17) of the pump (18) has a fitting (19) that allows fluid to enter the Pressure Multiplication System (P), 85 which is supported by a bracket (20). Buffer fluid from the Pressure Multiplication System (P) flows through a pipe (21) which is attached to the pump (18) seal chamber. The fluid returns to the Pressure Multiplication System (P) via a pipe (22).90 It will be realised that the Pressure Multiplication System according to this invention is not restricted to the form of a single fixed area piston as shown in the example, but may use one or more variable ratio pistons and sleeves.95 Industrial ApplicabilityBy the use of the Pressure Multiplication System of this type, the mechanically sealed chamber of the pump will be positively sealed and the leakage of toxic or valuable products will be prevented.SUBSTITUTE SHEET 100 The claims defining the invention are as follows;

1. A Pressure Multiplication System comprising a two stage piston compressing fluid within a similarly sized sleeve and fitted at each end with end plates thereof, both of which are adapted to suit fittings

105 for pipe connections.

2. A Pressure Multiplication System of claim 1. wherein a fixed ratio piston with two different sized surface areas, and seals fitted thereon, slides axially within a sleeve, being fitted into end plates

110 at each end thereof, one end being attached to the pump discharge pipe, and the other to the pipes connecting the device to the pump seal chamber. An outer sleeve is also fitted to the end plates to provide a reservoir of buffer fluid.

115 3. A Pressure Multiplication System substantially as herein described with reference to the accompanying drawings.

SUBSTITUTE SHEET