Web Transfer Nozzle Device for High-Speed Edge Strip Guidance
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Solution Overview
Problem
Existing web transfer devices in web manufacturing or processing machines face issues at high speeds, including double stripe formation, inefficiency due to air nozzle reversals, and increased centrifugal forces, leading to turbulence and maintenance challenges.
Innovation Solution
A device utilizing a sequence of gas flows, including a first blowing effect, a suction effect, and a final blowing effect, to stabilize and guide the web edge strip, reducing pressure and volume of the gas flow, and minimizing flutter and maintenance needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If blown air is guided through air guide grooves to accelerate the web strip, then the web strip momentum is increased and it is sucked onto the guide surface, but at high web speeds the webs between the grooves act like a ski jump and guide the web strip away from the scraper
Solution Approach 1:
The air guide surface is segmented into multiple grooves that are arranged to create localized suction zones rather than a single continuous groove. This segmentation allows the air flow to be distributed in a way that maintains web contact across the entire guide surface, preventing the web from being lifted away at high speeds while still providing adequate acceleration.
Solution Approach 2:
Different regions of the air guide surface have different groove configurations optimized for their specific functions. The grooves are positioned and dimensioned to create varying air flow patterns - some areas emphasize acceleration while others emphasize web retention, allowing each local region to perform its specific function optimally.
2Loss of time
If the web strip is accelerated intensively to assume the desired path quickly, then the web tension is increased, but centrifugal forces become effective and increase, requiring higher web weight and higher web speed for compensation
Solution Approach 1:
The air guide grooves are positioned and configured to apply air flow forces in advance of where the web would naturally deviate at high speed. By creating suction zones before the web encounters significant centrifugal forces, the system prepares the web for the upcoming high-speed section, allowing it to maintain proper positioning without requiring excessive web weight or speed increases.
3Ease of operation
If the air flow strength is increased to compensate for reversal of direction, then the web is conveyed more effectively, but turbulence increases which is disadvantageous
Solution Approach 1:
Instead of using high-velocity air jets that create turbulence, the invention inverts the approach by using controlled suction through grooves. This creates a gentler, more uniform air flow pattern that effectively conveys the web while minimizing turbulence. The suction mechanism naturally dampens flow irregularities compared to forced high-speed jets.
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
The device ensures reliable web transfer at high speeds with reduced propellant consumption, improved contact with the guide device, and enhanced stability against centrifugal forces, resulting in a robust and low-maintenance solution.
Implementation Method 1
uses a gas flow, in particular blown air, as a driving medium, which accelerates the edge strip 7 by exchange of momentum
Implementation Method 2
A suction zone formed in this way acts on the edge strip, which is sucked in as a lead-in strip and rests against a guide device
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
The device has a controlling system extended along a travel path of a web, where a nozzle (16) of a nozzle device (15) is protruded into the mixing chambers (20). A fluid jet (21) forms a propulsion jet, which accelerates a suction medium in the respective mixing chambers. A suction flow (25) for controlling an air flow (26) is carried out by the suction medium an area between the gas flows (17,19). The former gas flow is generated by the nozzle opposite to a conveying direction (L) of the web material. A negative pressure is created at the top of the controlling system by the suction flow.