Cross-Flow Filtration Sieve with Reversible Particle Layer
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Solution Overview
Problem
Existing cross-flow filtration methods using fine polymer membranes face issues with chemical instability, susceptibility to abrasion, and sensitivity to temperature, leading to filtration resistance and reduced throughput due to filter cake formation and impurities, which conventional cleaning methods cannot effectively address.
Innovation Solution
Employing a sieve with larger pore sizes than the average particle size and forming a permeable target particle layer as the separation medium, which is periodically cleaned by reversing differential pressure and using a pulsed flow to remove deposited particles, while maintaining a controlled filtrate discharge to ensure high purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fine polymer membranes with small pore sizes are used for filtration, then filtrate purity is improved, but the membranes suffer from chemical instability, abrasion susceptibility, and temperature sensitivity leading to reduced reliability
Solution Approach 1:
The patent uses a composite structure consisting of a robust support screen combined with a permeable particle layer. The support screen provides mechanical strength and chemical stability, while the particle layer performs the actual filtration. This composite approach allows achieving fine filtration results without using fragile polymer membranes throughout the entire structure.
Solution Approach 2:
The support screen acts as an intermediary structure that carries the permeable particle layer. Instead of relying on the polymer membrane to provide both structural support and filtration function, the system separates these functions: the screen provides structural support while the particle layer provides filtration, resolving the contradiction between purity and reliability.
2Manufacturing precision
If fine polymer membranes are used for filtration, then filtrate purity is improved, but filtration resistance increases due to filter cake formation and particle deposition
Solution Approach 1:
Instead of trying to prevent particle deposition on the filtration surface, the patent inverts the approach by allowing particles to form a permeable layer that becomes part of the filtration system. The particle layer is designed to be permeable and is periodically removed, transforming the harmful filter cake into a functional component.
Solution Approach 2:
The system employs periodic backflushing to remove the permeable particle layer at intervals. This periodic cleaning prevents the buildup of excessive filtration resistance while maintaining the benefits of the particle layer during filtration operation, thus balancing purity and throughput over time.
3Device complexity
If conventional filtration methods are used without periodic cleaning, then device complexity is reduced, but filtration resistance increases and throughput decreases
Solution Approach 1:
The system incorporates a self-cleaning capability through backflushing, where the filtration system cleans itself by reversing the flow to remove accumulated particles. This automatic cleaning function is integrated into the existing filtration operation without requiring separate complex cleaning systems or manual intervention.
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 approach ensures consistent, high-quality filtrate production by preventing contamination and maintaining filtration efficiency through periodic cleaning and targeted particle retention, allowing for continuous operation with minimal clogging.
Implementation Method 1
a sieve is initially used as the separating element, which sieve has an average pore size that is larger than the average particle size of the solid in the suspension
Implementation Method 2
a permeable target particle layer is specifically filtered onto the sieve and is then formed as the actual separation medium for separating particles
Implementation Method 3
the target particle layer is removed from the sieve at specific cleaning times in a cleaning phase
Implementation Method 4
which is periodically cleaned by reversing differential pressure and using a pulsed flow to remove deposited particles
Implementation Method 5
Method for separation of a suspension by means of a cross-flow filtration into a concentrate and a filtrate
Data Source
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AI summary
The invention relates to a method and a device for separating a suspension into a concentrate and a filtrate by means of cross-flow filtration, wherein the suspension is fed into a suspension chamber with several chamber-like modules arranged in series, each of which contains at least one annular separation element with a separation surface, in each module at least one agitator with radially arranged stirring elements is moved in the suspension chamber at a small distance above the separation surface relative to it, so that a directed flow transverse to the separation surface is generated in a gap between the agitator and the separation surface, for filtration a differential pressure is set between the suspension chamber and a filtrate chamber located on a side of the separation element facing away from the suspension chamber, filtrate which penetrates the separation element due to the applied differential pressure is discharged via a filtrate line.The suspension remaining in the suspension chamber is concentrated into a concentrate, which is then discharged from the chamber via a drain. A sieve with a mean pore size larger than the mean particle size of the solids in the suspension is used as the separation element. A permeable, pre-filtered particle layer is selectively formed on the sieve to separate particles and produce a pure filtrate. At specific cleaning times, the pre-filtered particle layer is removed from the sieve during a cleaning phase. Subsequently, the pre-filtered particle layer is rebuilt by infiltrating particles during a build-up phase, and the filtrate is discharged separately as a turbid effluent via a turbid effluent line during the build-up phase.