Cyclic Filtration System With Oscillating Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filtration methods face challenges in maintaining high flux rates and preventing surface cake buildup and concentration polarization, leading to reduced membrane permeability over time.
Innovation Solution
The use of oscillating transmembrane pressures with varying volume and pressure to continuously lift and remove solids from the separation surface, combined with air or gas sparging to create pulsed flows that disrupt cake formation, allowing for continuous filtration and backwashing without interrupting the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional filtration methods are used to remove fluids from components, then separation is achieved, but particulate matter deposits on the separation surface forming a cake that reduces membrane permeability over time
Solution Approach 1:
The system implements periodic backwashing cycles where the filtration process is temporarily interrupted to reverse flow through the membrane, dislodging and removing accumulated cake layers. This periodic reversal restores membrane permeability without requiring full system shutdown, maintaining continuous operation while preventing flux rate degradation.
Solution Approach 2:
The system maintains continuous filtration operation by implementing rapid backwashing cycles that occur during normal operation rather than requiring system shutdown. The cross-flow mechanism continuously removes particulate matter from the membrane surface, ensuring uninterrupted productive action while preventing cake buildup that would otherwise reduce permeability over time.
2Productivity
If pressure is increased to maintain flux rates, then filtration efficiency is improved, but cake buildup and concentration polarization are exacerbated
Solution Approach 1:
The system employs hydraulic cross-flow across the membrane surface during filtration to prevent particulate deposition. By directing fluid flow parallel to the membrane surface, the hydraulic force continuously sweeps away accumulating cake layers, allowing high pressure operation to maintain flux rates without exacerbating cake buildup and concentration polarization.
Solution Approach 2:
Periodic backwashing cycles reverse the pressure gradient through the membrane, using the pressure differential to flush accumulated cake layers from the separation surface. This periodic pressure reversal eliminates cake buildup and concentration polarization that would otherwise be exacerbated by continuous high-pressure filtration, restoring membrane permeability while maintaining productivity.
3Reliability
If the filtration process is stopped to backwash the separation surface, then cake removal is achieved, but system productivity is reduced due to shutdowns
Solution Approach 1:
The system implements continuous cross-flow filtration where fluid continuously flows parallel to the membrane surface during operation, preventing cake accumulation and maintaining separation surface cleanliness without interrupting the filtration process. This eliminates the need for shutdowns while preserving productivity, as the useful action of filtration continues uninterrupted.
Solution Approach 2:
The system performs rapid backwashing cycles during normal operation rather than requiring complete system shutdown. These periodic backwash pulses occur inline with continuous filtration, allowing cake removal and surface cleaning without significant interruption to overall system productivity and continuous operation capability.
4Reliability
If sparging is used to clear solids from the membrane, then surface cleaning is improved, but normal flows and pressures are disrupted decreasing flux rates
Solution Approach 1:
The system employs hydraulic cross-flow instead of gas sparging to clear solids from the membrane surface. By directing high-velocity fluid flow parallel to the membrane surface, the hydraulic force effectively removes particulate matter and maintains surface cleanliness while preserving normal flow patterns and pressure gradients, avoiding the flux rate disruptions caused by sparging.
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 significantly increases continuous flux rates and solids concentrations by regularly cleaning the separation surface, reducing the need for frequent system shutdowns and maintaining high filtration efficiency.
Implementation Method 1
The moving component can create a positive pressure to force the influent through the separation surface to form a filtrate
Implementation Method 2
creating a negative pressure to draw the backwash fluid through the separation surface
Implementation Method 3
the combination of the hydrodynamic shear stresses, bubble-induced turbulent flow, and cross flows can clear solids from the membrane
Implementation Method 4
Air or gas sparging can also be an additional motive force. Sparging, in this context, forms pulsed flows across the filtration membrane
Data Source
AI summary
A method of filtering a fluid with components includes providing an alternating pressure. The alternating pressure yields an oscillating transmembrane pressure through volume and pressure variations within a filtration chamber while sealing the filtration chamber. A separation surface can be housed in the filtration chamber wherein an influent is introduced. Components can be concentrated on the separation surface, effectively removing some or all of them from the fluid. To flush the filtration chamber and separation surface, a backwash fluid and components can be introduced and removed from the filtration chamber. While both the components are being concentrated and backwashed, the system can maintain the oscillating transmembrane pressure and varying volume and pressure relative to the separation surface.