Perforated Valve Plug Helical Hole Layout for Uniform Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control valve designs with sleeve-shaped closure parts, or perforated cones, face challenges in achieving a uniform flow rate characteristic over a wide range, particularly when handling hazardous substances like oxygen, where a linear or equal percentage flow rate adjustment is desired, but often result in irregular flow characteristics and mechanical stability issues.
Innovation Solution
The design features a perforated cone with openings arranged on at least one helical line, where the ratio of maximum to minimum land width between adjacent openings is between 1 and 1.5, allowing for a uniform flow rate characteristic, and the number of helices is minimized to ensure mechanical stability and ease of manufacturing, with optional omission of openings to achieve an equal percentage flow characteristic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If openings are arranged in horizontal rows on the perforated cone, then the valve structure is simple to manufacture, but the flow rate increases unevenly and the flow characteristic is inconsistent
Solution Approach 1:
The patent applies a helical arrangement of openings on the conical surface instead of straight horizontal rows. The helical path wraps around the cone in a spiral pattern, creating a curved geometric configuration that transforms the linear row structure into a three-dimensional spiral pattern. This curvature allows openings to be distributed more uniformly around the cone, ensuring that as the cone retracts, openings are exposed progressively and evenly, resulting in a smooth and consistent flow characteristic while remaining manufacturable through standard drilling or punching processes.
2Stability of the object's composition
If openings are spaced far apart on the conical valve, then the valve structure is mechanically stable, but the maximum possible flow rate is not achieved
Solution Approach 1:
The patent implements variable spacing of openings along the helical path, where the distance between adjacent openings changes at different locations on the cone. Near the shut-off position, openings are spaced more closely to enable precise flow control and achieve higher maximum flow rates. As the cone moves toward the fully open position, the spacing increases to maintain mechanical stability of the cone structure. This local variation in opening density allows the valve to simultaneously achieve both high flow capacity and structural integrity.
3Reliability
If a regular hole pattern with touching holes is used, then the flow characteristic is nearly linear, but the web width between holes is insufficient for hazardous substances like oxygen
Solution Approach 1:
The patent employs an asymmetric helical arrangement of openings that breaks the symmetry of regular grid patterns. The helical path creates irregular spacing and angular relationships between adjacent openings, preventing the formation of continuous pathways that could compromise structural integrity. This asymmetric configuration ensures that the web material between openings maintains sufficient width and distribution to safely contain hazardous substances like oxygen, while still achieving the desired linear flow characteristic through the progressive exposure of openings during cone retraction.
4Ease of operation
If the same additional area is released when the valve is raised by one step, then the flow rate increases linearly, but a proportional relationship according to DIN EN 60534-2-4 is desirable
Solution Approach 1:
The patent creates a dynamic flow characteristic through the helical opening arrangement, where the effective flow area does not increase uniformly with valve position. Instead, the helical geometry causes the exposed opening area to change non-linearly during cone retraction, with different rates of area increase at different positions. This dynamic variation in flow area progression enables the valve to achieve a proportional flow characteristic that conforms to DIN EN 60534-2-4 standards, where equal changes in valve position produce equal percentage changes in flow rate, rather than a simple linear relationship.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Control valves find one of their most important applications in the control loops of process plants for controlling the flow rate of a gaseous or liquid medium. For this purpose, it is crucial that the flow rate can be reliably adjusted and safe operation, especially with hazardous substances, can be ensured. To solve this problem, a hole pattern for the conical holes (300) of control valves is proposed, which allows for the densest possible arrangement of openings (220) on helical lines, while minimizing the height of the helical lines and simultaneously taking into account advantageous technical specifications and safety requirements. This allows, firstly, the generation of a very uniform flow characteristic, enabling reliable control of the flow rate. Secondly, the flow rate can be optimized so that the size of the moving parts of the control valve can be reduced to a minimum.