Grounded Detergent Air Filter for Low-Resistance Particle Capture
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Solution Overview
Problem
Existing air filters experience degradation in particle efficiency over time, leading to reduced performance, and methods like electrostatic attraction or fine fiber spacing increase airflow resistance, making them undesirable for certain applications.
Innovation Solution
An air filter impregnated with a liquidus solution containing a detergent, hygroscopic agent, and electrolyte, combined with a grounded metal grid, uses Coulombic forces to attract and neutralize dust particles, maintaining efficiency without significantly increasing airflow resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrostatic attraction is used to achieve MERV-12 level filtering, then particle efficiency is improved, but airflow resistance increases
Solution Approach 1:
The patent changes the electrical parameter by using a grounded metal grid that induces mirror charges in response to charged particles, rather than maintaining a fixed electrostatic charge. This dynamic parameter change allows the filter to attract particles through Coulombic forces without the energy loss associated with maintaining a permanent electrostatic charge, thereby improving particle efficiency while minimizing airflow resistance.
Solution Approach 2:
The patent replaces the mechanical/electrostatic charge maintenance system with an electrical induction system. Instead of mechanically or chemically charging the filter media, the grounded metal grid uses electrical induction to create mirror charges that attract particles. This substitution eliminates the need for continuous energy input to maintain electrostatic charges, reducing airflow resistance while maintaining high particle efficiency.
2Reliability
If microscopically spaced fine fibers are used to maintain high MERV performance, then particle efficiency is improved, but airflow resistance increases
Solution Approach 1:
The patent uses a composite structure combining a metal grid with filter media impregnated with liquidus solution. The metal grid provides the electrostatic induction capability while the liquidus solution-coated media provides particle capture. This composite approach allows the system to achieve high particle efficiency through Coulombic attraction without requiring the dense fiber spacing that would increase airflow resistance.
Solution Approach 2:
The liquidus solution acts as an intermediary between the metal grid and the particles. It provides a conductive path that enhances the Coulombic attraction while allowing air to flow through more easily than through tightly packed fibers. The liquidus solution mediates the interaction between the electrostatic field and particles, maintaining efficiency without the airflow penalty of fine fiber spacing.
3Reliability
If electrostatic charges are imposed on filter medium, then particle efficiency is improved when clean, but efficiency degrades during use cycle
Solution Approach 1:
The grounded metal grid system is self-regulating and does not require external charging or maintenance. As particles are captured, the grid automatically adjusts its mirror charge distribution to continue attracting particles. The system serves itself by using the ground as an infinite charge reservoir, eliminating the degradation problem of fixed electrostatic charges that are depleted during the use cycle.
Solution Approach 2:
The patent transitions from a static electrostatic charge system to a dynamic induction system. The mirror charges on the metal grid are not fixed but dynamically adjust in response to incoming charged particles. This dynamic behavior allows the system to maintain consistent particle efficiency throughout the use cycle, as the induction effect is continuously regenerated by the interaction between particle charges and the grounded grid.
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 filter maintains consistent MERV 12-level performance for three months while reducing airflow resistance, effectively capturing both strongly and weakly charged particles, including oil mist, without the need for high face velocities or complex structures.
Implementation Method 1
uses Coulombic forces to attract and neutralize dust particles
Implementation Method 2
The liquidus solution comprising, a detergent; a hygroscopic agent; and an electrolyte
Data Source
AI summary
An electrostatics-enhanced air filter that produces an electrostatic attraction for dust particles using an electrical ground or electrically charged filter is disclosed. The present invention takes advantage of the mirror-charge effect that spontaneously induces an opposite and attractive charge on the filter that pulls in dust particles. A fibrous filter medium pad is impregnated with a liquidus solution, which is a conductive aqueous electrolyte solution which would capture dust particles. Charges on dust particles would be drained off through the liquidus solution to the ground, preventing the effective electrical potential of the filter from changing. The liquidus solution also contains a detergent that keeps the filter clear of oily air contaminants to maintain conductivity through the filter service life. The liquidus solution contains a wetting agent for engulfing dust particles therein/thereon. The liquidus solution also contains a hygroscopic agent that prevents it from partially drying during its use.