Powder Feed Pressure Control Using Differential Pressure Feedback
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Solution Overview
Problem
Current powder feed rate control systems rely on mechanical computing relay regulators, which are less accurate, prone to recalibration, and less reliable, and fail to maintain precise differential pressure in real-time without external input.
Innovation Solution
The system replaces mechanical components with an electro-pneumatic regulator and differential pressure transducer, directly coupled for precise control of powder feed rate, maintaining differential pressure between 0 and 1 bar regardless of process pressure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical computing relay regulator (CRR) is used to control hopper pressure, then the system can maintain pressure drop across the orifice, but the system requires frequent recalibration and has reduced accuracy
Solution Approach 1:
The patent replaces the mechanical computing relay regulator (CRR) with an electronic differential pressure transducer and control system. The mechanical pressure sensing and regulation mechanism is substituted with electronic sensors that measure differential pressure and electronic control elements that regulate hopper pressure, eliminating mechanical wear and calibration drift issues.
Solution Approach 2:
The patent implements a feedback control system where the differential pressure transducer continuously monitors the pressure difference across the carrier conduit orifice and feeds this information back to the pressure regulator. This closed-loop feedback enables automatic adjustment of hopper pressure to maintain precise control of powder feed rate without manual recalibration.
2Reliability
If a mechanical CRR system is used, then pressure control is achieved, but the system complexity increases and reliability decreases
Solution Approach 1:
The patent eliminates multiple mechanical components including the CRR's mechanical adding mechanism, manual adjustment screws, and mechanical linkages. These are replaced with an electronic differential pressure transducer and electronic pressure regulator, reducing mechanical wear points and simplifying the overall system architecture.
Solution Approach 2:
The patent extracts and removes the mechanical CRR component entirely from the system. By taking out this complex mechanical device that performed pressure addition and regulation, the system is simplified to use direct electronic differential pressure measurement and control, reducing component count and potential failure points.
3Manufacturing precision
If manual adjustment screw calibration is used, then factory setting can be established, but the system is prone to drift and requires recalibration
Solution Approach 1:
The patent replaces manual adjustment screw calibration with an electronic feedback control system. The differential pressure transducer provides continuous real-time measurement of pressure differential, and the electronic control system automatically maintains the setpoint pressure drop across the orifice, eliminating calibration drift associated with mechanical adjustment mechanisms.
Solution Approach 2:
The patent implements a self-regulating system where the electronic control continuously monitors and adjusts hopper pressure based on actual differential pressure measurements. The system serves itself by automatically compensating for any deviations from the target pressure drop without requiring external manual recalibration or adjustment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances sensitivity, accuracy, and reduces the need for recalibration, ensuring consistent powder delivery to spraying devices with improved product performance and cost reduction.
Implementation Method 1
The differential pressure transducer outputs a signal related to a differential pressure between the hopper pressure and the process pressure
Implementation Method 2
an electro pneumatic regulator which receives command voltage and receives the signal related to the differential pressure
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Powder feed rate control system that includes a hopper adapted to contain a powder and to maintain a hopper pressure. A carrier conduit delivers a carrier gas flow and having an orifice. The carrier gas flow conveys powder entering through the orifice at a powder feed rate. A differential pressure transducer includes a first pressure input associated with the hopper pressure and a second pressure input associated with the carrier gas flow downstream of the hopper. The differential pressure transducer (PT) outputs a signal related to a differential pressure between the first pressure input and the second pressure input. An electro pneumatic regulator (EP) is adapted to communicate with a control and receiving the signal related to the differential pressure.