Water Jet

Water jet intensifier pump having a piston arrangement with a ceramic liner

Water Jet Abstract
An intensifier pump for a water jet pump includes an exterior cylinder having a fluid inlet port and a fluid outlet port. A valve is disposed at the fluid outlet port. The intensifier pump includes a piston head and a plunger disposed within the exterior cylinder and which is driven by fluid entering the inlet port. An interior cylinder is disposed within the exterior cylinder. A piston having an anterior plunger is disposed within the interior cylinder and is driven by the plunger for compressing a fluid in a compression chamber to flow through the valve. A ceramic liner is disposed within the interior cylinder and circumferentially disposed around the compression chamber.

Water Jet Claims
What is claimed is:

1. An intensifier pump for a water jet pump comprising:

an exterior cylinder having a fluid inlet port and a fluid outlet port;

a valve disposed at said fluid outlet port;

a first piston having a first plunger disposed within said exterior cylinder and driven by fluid entering said inlet port;

an interior cylinder having a compression chamber disposed within said exterior cylinder, said interior cylinder having a first diameter;

a second piston having a second plunger disposed within said interior cylinder and driven by said first plunger for compressing a fluid in said compression chamber to flow through said valve; and

a ceramic liner disposed within said interior cylinder and circumferentially disposed around said compression chamber, said interior cylinder having a second diameter, less than said first diameter, with said ceramic liner disposed within said interior cylinder, said interior cylinder thereby compressing said ceramic liner, such that said ceramic

liner is continuously under compression during operation of said pistons and experiences no stress reversal during operation of the intensifier pump.

2. The intensifier pump of claim 1 and further including seals disposed on said second plunger for engaging said ceramic liner.

Water Jet Description
TECHNICAL FIELD OF THE INVENTION

The present invention relates to water jet pumps, and more particularly to an intensifier performing at increased operating pressures.

BACKGROUND OF THE INVENTION

A typical water jet pump operates in a pressure range of up to 60,000 psi. This limit is established by the availability of materials that will withstand pressure cycling without fatigue failures. A typical intensifier pump includes a cylinder pressed on by a fluid, normally oil. This cylinder drives a plunger which displaces a second fluid such as, water, in a compression chamber. The pressure of the fluid in the cylinder causes a force equal to the area of the cylinder multiplied by the pressure in the cylinder. The pressure in a compression chamber driven by a second plunger is raised to a ratio of the area of the cylinder divided by the area of the compression chamber. The output and input of the compressed fluid is regulated by intake and output check valves.

It is desirable that the cylinder within the compression chamber withstand high operating pressures. Cylinders are manufactured by imposing exterior compressive loads on an interior cylinder. This compression causes the interior wall to have a static compressive stress. Other techniques for achieving compressive stress include adding a hoop around the interior cylinder of smaller inside diameter than the outside diameter of the liner. This strain produces a compressive stress in the inner surface of the inside cylinder. Additionally, autofrettage is achieved by imposing a high pressure on the inner surface of a solid cylinder. A compressive stress is therefore applied on the inside of the cylinder wall.

A need has arisen for intensifier pump having an interior cylinder that can withstand increased pressures and cycling loads. Such a pump must be easy to manufacture and maintain.

SUMMARY OF THE INVENTION

In accordance with the present invention, an intensifier pump for a water jet pump includes an exterior cylinder having a fluid inlet port and a fluid outlet port. A valve is disposed at the fluid outlet port. The intensifier pump includes a piston head and a plunger disposed within the exterior cylinder and which is driven by fluid entering the inlet port. An interior cylinder is disposed within the exterior cylinder. A piston having an interior plunger is disposed within the interior cylinder and is driven by the plunger for compressing a fluid in a compression chamber to flow through the valve. A ceramic liner is disposed within the interior cylinder and circumferentially disposed around the compression chamber.