Vortex Chamber Homogenizing Device for Fiber Web Streaks
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Solution Overview
Problem
Existing methods for producing nonwoven webs from aqueous fiber suspensions suffer from basis weight fluctuations due to local differences in fiber deposition, leading to uneven structures and streaks in the final product, which are difficult to prevent using conventional devices.
Innovation Solution
A device with a vortex chamber and a homogenizing system that introduces the fiber suspension through multiple equally long hoses or bores, creating a stagnation point flow and high shear forces to separate and mix fibers uniformly, preventing streak formation by generating large-scale transverse vortices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If tube bundles with diffusers are used to break up fiber flocs, then fiber separation is achieved through strong turbulence, but uneven basis weight distribution and streak formation occur
Solution Approach 1:
The invention divides the fiber suspension flow into multiple sub-streams using a perforated plate with multiple openings, rather than using a single tube bundle. This segmentation approach distributes the turbulence generation across multiple locations, preventing concentrated streak formation while achieving uniform fiber separation throughout the suspension
Solution Approach 2:
Instead of using tube bundles that create turbulence in a concentrated manner, the invention inverts the approach by using a perforated plate that distributes turbulence generation across many small openings. This reverses the concentration of shear forces from a few intense locations to many distributed locations, eliminating streaks while maintaining fiber separation effectiveness
2Manufacturing precision
If moving elements such as perforated rollers are used to break up fiber flocs, then fiber separation is improved, but device complexity and space requirements increase
Solution Approach 1:
The invention inverts the conventional approach by replacing moving perforated rollers with a stationary perforated plate. The plate remains fixed while the fiber suspension flows through it, generating the necessary turbulence and shear forces passively. This eliminates the need for moving parts, motors, and complex drive mechanisms while achieving the same fiber separation quality
Solution Approach 2:
The stationary perforated plate utilizes the kinetic energy of the flowing fiber suspension itself to generate turbulence and shear forces. The flowing suspension passesively breaks up fiber flocs as it moves through the plate openings, without requiring external power sources or active mechanical intervention. The system serves itself using the energy already present in the flowing material
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
Achieves a uniform fiber distribution across the transverse direction, eliminating streaks and improving the basis weight uniformity, while reducing the need for moving components and minimizing space and cost.
Implementation Method 1
Strong turbulence with high shear rates develops within the tube bundles, leading to the fibers in the fiber suspension being separated
Implementation Method 2
Strong turbulence with high shear rates develops within the tube bundles
Implementation Method 3
The inlets on the inlet side are arranged such that the flow is directed towards the guide side. This creates a stagnation point flow, dividing the flow into one sub-stream and another sub-stream
Implementation Method 4
The transition into the vortex chamber and from the stream to the sub-streams introduces a high degree of kinetic energy into the fiber suspension, allowing the fibers to be separated by sufficiently high shear forces and turbulence
Implementation Method 5
Typically, one or more laminar and non-laminar vortices form, which can extend dominantly across the entire width or length of the vortex chamber
Implementation Method 6
The fibrous suspension is introduced into the vortex chamber in a stream via a plurality of preferably equally long hoses, pipes and/or bores
Data Source
Figure 1~2
Figure 3~4
AI summary
A device (1) for producing a fibrous web is proposed, comprising a headbox (10) with a vortex chamber (3) and an equalizing device (11) for uniformly introducing a fibrous suspension into the vortex chamber (3), wherein the equalizing device (11) for introducing the fibrous suspension in a stream (A) has a plurality of hoses (9), pipes and/or bores of equal length, each with an inlet (8) on a feed side (4) of the vortex chamber (3), wherein a guide side (5) is arranged opposite the feed side (4) in such a way that a stagnation point flow of the stream (A) is created, wherein the stream (A) is divided into a partial stream (B) and a further partial stream (C). A method for producing a fibrous web is also proposed.