Methodology for design of a vibration operated valve for abrasive viscous fluids

• A new ultrasonic operated valve that can meter flow of abrasive fluids is presented.
• This innovative valve concept is based on controlling the friction along the flow direction.
• Some important factors are pressure, size of friction blades, density, viscosity and amplitude.
• The ultrasonic valve was prototyped and tested for flow control of abrasive viscous fluid.
• Pulse width modulation was used to control the flow of the ultrasonic valve.

In this paper a new ultrasonic operated valve is presented. The ultrasonic valve design was analyzed and the valve was prototyped and tested for flow control of abrasive viscous fluid. This innovative valve concept is based on controlling the friction of material by employing several friction elements along the flow direction. Abrasive particles in the viscous fluid are stopped by the force of friction when coming into contact with the friction elements. Friction is neutralized by use of vibration to break away the abrasive particles from the friction element surfaces. Several factors were considered in designing the piezoelectric valve. Factor identification was done by conducting experiments and analyzing the resulting data. Some important factors that affect the valve design were recognized to be pumping pressure, size of friction blades along the direction of flow, density of material, viscosity, amplitude of vibration, frequency of vibration, and proportion of abrasive particles in the mix. First, a method was designed for measuring the friction coefficient of the given viscous materials. A design of experiment approach was pursued in order to identify the significant parameters. A piezoelectric transducer was used, which vibrated at the resonance frequency of 20 kHz. FEM modeling was used at that stage to ensure that the resonance frequency of the designed valve matched the resonance frequency of the transducer and booster assembly that provided vibration. In order to perform proportional flow control pulse width modulation was used to control the duty cycle of the ultrasonic power transferred to the valve. A study was performed to find the best vibration characteristics.