High Pressure Intensifier

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TABLE OF CONTENTS

CHAPTER 11

Design theory and design example of high pressure intensifier for high pressure water jet generation1

Variable flow2

REFERENCES7

CHAPTER 1

Design theory and design example of high pressure intensifier for high pressure water jet generation

The water jet cutters produced by KMT use high pressure water between 30,000 to 60,000-psi in conjunction with a robotic arm to manufacture a variety of items and are often used in the manufacture of automobile parts. KMT wants a flow monitoring system suitable for a high-pressure environment that can accurately detect if the flow-rate is within acceptable limits during a cutting operation and signals the computer system whenever the flow-rate is within the acceptable, user-defined range. During the cutting process, the high-pressure flow of water is turned on and off repeatedly and typically makes many cuts into a single part (Bachelor 2007, 25).

Currently, a water pressure monitor, in conjunction with an intensifier pump, ensures that the ideal pressure levels are maintained. However, on occasion, an insufficient amount of water will flow out of the orifice due to blockage of the nozzle or leakage in the high pressure line. This results in the water jet cutter occasionally missing a cut. This results in a lower quality level for parts shipments, which is not ideal. The introduction of a flow monitoring system on the water jet cutters would prevent this occurrence and increase the quality of parts manufactured using KMT's product. KMT believes that this flow monitoring system would be a very popular addition to their water jet cutters (Liu 2010, 8-18).

A magnetic flow measures flow-rate by measuring the voltage difference induced between set lengths of tubing when a magnetic field is applied to the fluid. The voltage difference induced when a conductor moves through a magnetic field is proportional to the velocity of the conductor, according to Faraday's Law. This allows the magnetic flow meter to be calibrated to measure the flow velocity of a conducting fluid. In our case, water jet cutters use tap water as the working fluid, which works as a conducting fluid for the magnetic flow meter. This method is non-invasive, does not create a significant drop in pressure, is not significantly affected by pressure, and can be placed close to the base of the machine (Begg 2011, 103). This method has potential problems, however. The flow-rates seen in water jet cutters are very small and pipe itself is relatively thick. Low flow magnetic flow meters can read down to 0.1-gpm, but it is not known if that accuracy can be achieved in the thick piping needed for our application. Additionally, the conductivity of tap water is likely to be variable which could affect the accuracy of the flow meter especially at such low flow rates. Overall, a magnetic type flow meter has good properties for our application, but it is questionable whether it will be accurate enough in our application (Liu 2008, 29).

Variable flow

A variable area flow meter measures the flow-rate by measuring the displacement of a flexibly attached ...