Scientific Systems 2 Active Pump Pulse Damper

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Scientific Systems 2Active Pump Pulse Damper

• Date December 12, 2006
• Jeff Domenick
• Bonnie Hanner
• Jacob Ricker
• John F. Waters

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Background

• Scientific Systems, Inc. designs and manufactures
  high pressure pumps for use in liquid
  chromatography
• HPLC requires a smooth flow of solvent to ensure
  accurate results.

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Old Design

• Previous system dampened pulsation passively via
  a small reservoir separated from the solvent by a
  flexible bladder
• Flow Systems has been asked to develop a new
  pulse dampening system that will actively respond
  to changes detected in flow pressure in order to
  maintain constant pressure more effectively than
  the current design

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Design Concept
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MR Fluid

• Magneto-rheological (MR) fluid is a fluid infused
  with iron particles in such a manner that
  exposure to a magnetic field alters the viscosity
  of the fluid

• Selected fluid is hydrocarbon-based, with a low
  viscosity

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Electromagnet Gate
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Linear Actuator

• The linear actuator will be utilized to create a
  control pressure that will be used as the working
  pressure of the MR fluid
• As the MR fluid is injected will iron particles,
  it will not be used in the piston, but we will
  use an intermediate fluid of isopropyl alcohol

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Assembly Layout
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Electronic Controls

• Electromagnet controlled by a system of
  Darling-ton transistors arranged as per the
  diagram at right

• Linear actuator control circuit consists of four
  solid state relays arranged in an H-bridge
  configuration

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Early Results

• Successful variable control of linear actuator
  via LabVIEW
• Successful variable control of electromagnet
• And then

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Oops
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Future Improvement

• Design remains plausible
• Further testing and proof of concept will
  hopefully occur in next day and a half
• Should concept prove successful, Scientific
  Systems could optimize and improve system
  considerably