Spray Gun Sensing and Control for Consistent SPF Impingement Mixing
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Solution Overview
Problem
Existing Spray Polyurethane Foam (SPF) systems face issues with impingement mixing due to unknown and unequal pressures and temperatures of fluid streams at the spray gun, leading to poor foam quality, irregular deposition, and potential system occlusion, as well as inadequate independent pressure control and temperature management.
Innovation Solution
The implementation of a spray gun system with independent pressure and temperature sensing and control at the spray gun, using pressure and temperature sensors to adjust pump actuators and heating systems, ensuring equal pressures and optimized momentum of fluid streams for improved impingement mixing, along with an air capless design and ergonomic handle for comfort and ease of use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent pressure and temperature sensing and control systems are implemented at the spray gun, then impingement mixing consistency and foam quality are improved, but device complexity and cost increase
Solution Approach 1:
The control system is segmented into independent pressure sensors and temperature sensors located at the spray gun, with separate control loops for each parameter. This allows independent monitoring and adjustment of pressure and temperature without requiring a fully integrated complex control system, thereby improving mixing consistency while managing overall system complexity.
Solution Approach 2:
Pressure sensors and temperature sensors provide real-time feedback to the control system, which automatically adjusts pump actuators and heating elements to maintain optimal pressure and temperature levels. This closed-loop feedback mechanism ensures consistent impingement mixing and foam quality without requiring manual intervention or overly complex control logic.
2Manufacturing precision
If pressure sensors and temperature sensors are located at the spray gun with independent control, then foam quality and deposition uniformity are improved, but system cost increases
Solution Approach 1:
Pressure and temperature are measured and controlled at the spray gun before the materials are applied, ensuring that the fluids are at the correct conditions for optimal mixing and foam formation. This preliminary control of parameters at the point of application prevents quality issues rather than requiring expensive post-processing or rework.
Solution Approach 2:
The system uses automated control based on sensor feedback to self-regulate pressure and temperature, reducing the need for manual adjustment and expert intervention. This self-service capability maintains high foam quality while reducing operational costs and simplifying the requirement for highly trained operators.
3Measurement precision
If pump actuators are adjusted based on pressure sensor feedback, then pressure control precision is improved, but device complexity increases
Solution Approach 1:
Pressure sensors provide continuous feedback to the control system, which automatically adjusts the pump actuators to maintain precise pressure levels. This simple feedback loop achieves high pressure control precision without requiring complex control algorithms or multiple actuators, as each pressure sensor directly controls its corresponding pump actuator in a straightforward closed-loop manner.
4Temperature
If heating elements are controlled by temperature sensors, then temperature management is improved, but device complexity and energy consumption increase
Solution Approach 1:
Temperature sensors provide feedback to the control system, which activates heating elements only when temperature drops below the setpoint. This feedback-controlled heating approach maintains optimal temperature for material viscosity and reaction rate while minimizing energy consumption by heating only when necessary, rather than continuous heating.
Solution Approach 2:
The system dynamically adjusts heating power based on actual temperature measurements and environmental conditions, changing the heating parameter (power level) to match the actual thermal requirements. This prevents excessive energy consumption while maintaining the temperature parameters needed for optimal foam formation and material flow.
Data Source
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AI summary
A fluid delivery system includes a spray gun (28). The spray gun includes a mix chamber assembly (362) having at least two bores (400, 402) configured to receive a first fluid and a second fluid, and a chamber (404) fluidly coupled to the at least two bores (400, 402), the chamber (404) configured to mix the first and the second fluid. The spray gun further includes a handle (302), and a winged extension (304) disposed to contact at least a portion of an operator's back hand when the operator holds the spray gun (28) via the handle (302).