Staggered Nozzle Tubes for Stable Web Transfer
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Solution Overview
Problem
Existing web transfer devices in web manufacturing or processing machines face inefficiencies due to unstable air carpet formation and increased turbulence, leading to issues like double stripes, loss of efficiency, and increased centrifugal forces at high web speeds.
Innovation Solution
The device improves air carpet formation by arranging nozzle tubes with different hole spacings and angles, using Coanda nozzles to create a stable air flow, and reducing turbulence by connecting individual flows in a specific sequence, which enhances the guidance and tensioning of the web strip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple hole nozzles are arranged next to each other to form an air carpet, then the directivity and efficiency of individual nozzles is high, but negative pressure is generated between the jets causing unstable air carpet formation and vortex occurrence
Solution Approach 1:
The nozzle arrangement is changed from a symmetric parallel configuration to an asymmetric staggered configuration where nozzles are offset from each other in the flow direction. This asymmetric arrangement prevents the formation of negative pressure zones between adjacent jets while maintaining the directivity and efficiency of individual nozzles, resulting in stable air carpet formation without vortices
Solution Approach 2:
The nozzle arrangement transitions from a one-dimensional parallel alignment to a two-dimensional staggered pattern. By introducing offset in the flow direction (another dimension), the nozzles no longer align directly opposite each other, eliminating the negative pressure interaction between adjacent jets while preserving the overall air carpet structure
2Speed
If blown air is guided through air guide grooves to give the web strip higher momentum, then the web strip is accelerated and tensioned, but the webs between grooves act like a ski jump guiding the web strip away from the scraper at high speeds
Solution Approach 1:
The air guide grooves are removed from the system and replaced by direct nozzle jets. The air guiding function is extracted from the groove structure and performed instead by strategically positioned nozzles that deliver air momentum directly to the web strip without creating the ski jump effect associated with grooved surfaces
Solution Approach 2:
The mechanical groove structure is replaced by a pneumatic solution using multiple nozzles. Instead of relying on the physical geometry of grooves to guide air, the system uses directed pneumatic jets to provide the necessary air momentum to the web strip, eliminating the harmful ski jump effect while maintaining effective web acceleration and guidance
3Stability of the object's composition
If slot nozzles are used to improve air carpet formation downstream, then the web transfer is enhanced, but air consumption increases significantly reducing efficiency
Solution Approach 1:
The single slot nozzle is segmented into multiple individual hole nozzles arranged in a staggered pattern. This segmentation allows for more precise control of air flow distribution while reducing overall air consumption. Each individual nozzle contributes to the air carpet formation efficiently, and the staggered arrangement prevents energy-wasting vortex formation between adjacent jets
Solution Approach 2:
The nozzle geometry is changed from a slot configuration to multiple hole configurations. This parameter change in nozzle design, combined with the staggered arrangement, achieves stable air carpet formation with significantly reduced air consumption compared to slot nozzles, as the holes create more focused and efficient air 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
This configuration results in improved web guidance, reduced turbulence, lower air consumption, and increased efficiency, with better power transmission and reduced maintenance requirements.
Implementation Method 1
The nozzle tubes have, for example, a different hole spacing in pairs and are not arranged parallel to one another in pairs. Alternatively, a combination of the two principles can also be set.
Implementation Method 2
These additional nozzles are preferably designed as Coanda nozzles. The Coanda design has the advantage that the individual jets quickly become an even carpet of air.
Implementation Method 3
The individual nozzles 16 form a row of nozzles whose gas or air flows 17 combine to form an air carpet in which the threading strip 6 is carried along through the drying section 1.
Implementation Method 4
The suction flow 25 causes air to be sucked in at the top of the guide device 14. Consequently, a suction zone is created, which acts on the edge strip in that it is sucked in and rests against the guide device 14.
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
The device has a guide device (14) extending along a travel path of a material web. An inlet-side nozzle device (15) and an outlet-side nozzle device (18) have nozzles (16, 37) i.e. open jet nozzles, for two types of gas flow, where one of the gas flow runs against conveying direction of the material web, and the other gas flow runs along the conveying direction. One of the nozzles is formed as nozzle tubes, and generates flow fields that are partially aligned in different manner. The nozzles are externally arranged in an array line in angular manner. USE : Device for transferring an edge strip of a web e.g. material web (claimed) such as paper web, in a station of a web production or processing machine e.g. paper machine, paperboard machine and fabric- or fiber machine. ADVANTAGE : The nozzle is formed as the nozzle tubes, and generates the flow fields that are partially aligned in different manner, thus constructing the transferring device with improved efficiency in a simple manner, improving random behavior of the jets of nozzle series for formation of an air carpet, eliminating hazard of tear of the air carpet at the end of the air guide device, designing robust and maintenance-free device, and reducing consumption of foaming agent. DESCRIPTION OF DRAWINGS : The drawing shows a schematic sectional view of an air guide device for producing gas flow by a nozzle device. 14 : Guide device 15 : Inlet-side nozzle device 16, 37 : Nozzles 18 : Outlet-side nozzle device 36 : Supply tube.