Adjustable Piston Stop Shut-off Valve for Paint Systems
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Solution Overview
Problem
In paint shops, significant paint losses occur during color changes due to the discharge of air and residual paint through shut-off valves with large channel cross-sections, leading to inefficiencies and increased waste, especially when refilling paint lines.
Innovation Solution
A pneumatically adjustable shut-off valve with a changeable piston stop allows for two operating modes: a large channel cross-section for flushing and a small cross-section for venting, minimizing paint losses by controlling the stroke of the piston stop to manage air and paint flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a shut-off valve with a large channel cross-section is used, then high flow rates during flushing are achieved, but excessive paint surge occurs during venting
Solution Approach 1:
The patent applies the dynamics principle by making the channel cross-section variable rather than fixed. The shut-off valve incorporates a movable shut-off body that can adjust the effective channel cross-section dynamically. During flushing operations, the valve maintains a large cross-section for high flow rates, while during venting operations, the cross-section is reduced to minimize paint surge and loss. This dynamic adjustment resolves the contradiction between needing high productivity during flushing and minimizing substance loss during venting.
2Productivity
If the piston stroke is increased to improve venting, then air discharge is enhanced, but paint surge increases
Solution Approach 1:
The patent applies the local quality principle by creating different flow conditions in different regions of the valve during the venting process. The movable shut-off body selectively opens or restricts specific portions of the channel cross-section. During air discharge, sufficient stroke is provided for efficient venting, but the channel geometry is locally modified to control paint flow characteristics, preventing excessive paint surge while maintaining air discharge efficiency.
3Device complexity
If a fixed channel cross-section is used, then device complexity is reduced, but adaptability to different operating modes is limited
Solution Approach 1:
The patent resolves the contradiction between device complexity and adaptability by implementing a dynamic adjustment mechanism controlled by a programmable controller. The movable shut-off body is actuated based on detected operating conditions (flushing vs. venting mode), allowing the valve to adapt its channel cross-section to different operating modes. While this adds some complexity, it enables the single valve to perform multiple functions optimally, rather than requiring separate fixed valves for each mode.
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 design reduces paint waste by allowing high flow rates during flushing while preventing excessive paint surge during venting, maintaining process speed and minimizing paint loss during color changes.
Implementation Method 1
a shut-off body (22) that can be moved pneumatically from a closed position into an open position via a pressure-actuated lifting piston (54)
Implementation Method 2
any residual paint that may still be in the paint-carrying line is usually pushed out of the respective paint-carrying line by means of a suitably selected pushing medium. Compressed air, for example, or preferably also a cleaning or rinsing liquid can be used as a pushing medium
Implementation Method 3
the working position of a piston stop (56) provided to limit the stroke of the reciprocating piston (54), viewed in its opening direction, can be adjusted
Data Source
AI summary
A shut-off valve (12), in particular for shutting off a paint-carrying channel in a painting system (1), with a shut-off element (22) that can be moved pneumatically from a closed to an open position via a pressure-actuated piston (54), is intended to be particularly suitable for use in a painting system designed for frequent color changes, whereby in particular the paint losses to be accepted during a color change are to be minimized as much as possible. For this purpose, according to the invention, the working position of a piston stop (56) provided to limit the stroke of the piston (54) in its opening direction is adjustable.