Servo-Positioner for Micro-Regulating Valve High Pressure Control
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Solution Overview
Problem
Micro-regulating valves in high-pressure, low-flow systems face limitations in scalability and precision due to mechanical building constraints, leading to low rangeability and issues with pressure control, especially when dealing with low flow rates and high pressures, resulting in inefficiencies and inaccuracies in laboratory-scale reactors.
Innovation Solution
A servo-positioner system for micro-regulating valves using a high-resolution, high-speed servomotor connected to a potentiometer or encoder via a flexible coupler, allowing precise positioning with minimal dead volume and the ability to operate at high temperatures, which includes a micrometric screw mechanism for adjusting the valve opening and using materials like stainless steel and Teflon for durability and chemical compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical pressure controller with diaphragm-spring mechanism is used, then pressure control is achieved, but the system suffers from offset errors and inability to maintain precise pressure at varying flow rates
Solution Approach 1:
The patent replaces the mechanical diaphragm-spring pressure controller with an electronic servo-positioning system that uses a servomotor, encoder, and control algorithm to position the valve shutter. This substitution eliminates mechanical offset errors and enables precise pressure control through electronic feedback, directly resolving the contradiction between measurement precision and reliability.
2Quantity of substance
If micro-regulating valves with low Cv values are used for high-pressure low-flow systems, then the valve can handle the required flow rates, but the scalability and rangeability are severely limited
Solution Approach 1:
The patent implements a dynamic control system where the servomotor continuously adjusts the valve shutter position based on real-time feedback from the encoder and pressure sensor. This dynamic positioning capability enables the valve to maintain precise control across a wide range of flow rates and pressures, achieving high rangeability (ratio between maximum and minimum controllable flow) without being constrained by the fixed mechanical characteristics of traditional micro-valves.
Solution Approach 2:
The system incorporates a closed-loop feedback mechanism using an encoder to monitor shutter position and a pressure sensor to monitor system pressure. The control algorithm uses this feedback to continuously adjust the servomotor position, enabling the valve to adapt to varying flow rates and maintain precise control across a wide operating range, thereby resolving the rangeability limitation.
3Ease of manufacture
If conventional valve machining methods are used with cylindrical openings and shutters, then manufacturing is simplified, but the precision and control accuracy are compromised
Solution Approach 1:
The patent segments the valve control function into distinct components: the servomotor provides rotational motion, the transmission mechanism (gears or belt) converts and multiplies this motion, and the shutter executes the positioning. This segmentation allows each component to be optimized independently - the shutter can be a simple cylindrical component easy to manufacture, while the precision is achieved through the segmented transmission and control system rather than through complex shutter geometry.
4Stress or pressure
If the valve operates at high pressures up to 400 bar, then the system can handle extreme conditions, but fluid leakage and sealing challenges increase
Solution Approach 1:
The patent employs composite material construction for the valve body and shutter, combining materials with complementary properties such as stainless steel for structural strength and sealing surfaces, paired with appropriate sealing materials. This composite approach enables the valve to withstand extreme pressures up to 400 bar while maintaining effective sealing and preventing fluid leakage through the combination of material properties rather than relying on a single material.
Data Source
AI summary
The invention relates to a positioning system which is suitable for micrometric regulating valves. The invention comprises a micro-regulating valve which is connected to the shaft of a servomotor by a flexible coupler and which is fixed to the same using a support. The aforementioned motor is, in turn, coupled to a potentiometer which transmits the position of the shaft of the motor and, consequently, of the rod of the valve to a control system which compares a signal received from an external control system with the position of the value, the position of the valve being corrected with a movement of the motor. In this way, a quick and precise positioning system can operate at high pressures and with very low flow rates.