Rotating Magnetic Drum for Continuous Mill Scale Filtration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The steel industry faces challenges in efficiently removing mill scale from industrial fluids during steel-working operations due to its poor magnetic susceptibility, high hardness, and small size, which leads to equipment damage and increased maintenance costs, as conventional filtration methods are either ineffective or economically unfeasible.
Innovation Solution
A system employing a rotating magnetic drum with a tailored magnetic field and bubble generation to attract and remove mill scale, using rare-earth magnets and non-magnetic materials to withstand abrasion, and a scraper to efficiently collect and dispose of the scale, allowing for continuous filtration and placement under steel-working equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional filtration methods are used to remove mill scale, then equipment damage is reduced, but the filtration is not economically feasible or effective
Solution Approach 1:
The patent replaces conventional mechanical filtration systems with a magnetic field-based separation system. The magnetic drum generates a magnetic field that attracts ferromagnetic mill scale particles from the coolant, eliminating the need for mechanical filters and enabling continuous removal without economic penalty
Solution Approach 2:
The patent changes the physical parameter used for separation from mechanical filtration to magnetic attraction. By exploiting the ferromagnetic properties of mill scale (Fe and Fe3O4), the system achieves effective removal through magnetic field interaction rather than mechanical filtering
2Productivity
If magnetic field strength is increased to attract mill scale, then scale removal efficiency is improved, but the magnetic circuit becomes too strong for scraper removal
Solution Approach 1:
The patent applies different magnetic field strengths to different regions of the drum. The magnetic circuit is designed with varying magnetic properties along the drum circumference: strong magnetic field in the collection region to attract scale, and weak magnetic field in the discharge region to allow scraper removal. This spatial variation in magnetic quality enables both efficient attraction and easy removal
Solution Approach 2:
The patent makes the magnetic field dynamic by rotating the magnetic drum. As the drum rotates, different segments of the drum surface experience different magnetic field conditions - the collection zone has strong magnetic attraction while the discharge zone has weak magnetic field, enabling continuous operation with periodic scraper removal
3Force
If magnetic drum size is increased to compensate for coolant flow rate, then scale attraction capability is improved, but the filter becomes too large for placement under equipment
Solution Approach 1:
The patent segments the magnetic field generation into discrete permanent magnets arranged around the drum circumference. This segmentation allows concentrated magnetic force at specific locations rather than requiring a large uniform magnetic field across the entire drum surface, reducing overall system size while maintaining attraction capability
Solution Approach 2:
The patent uses permanent magnets (composite magnetic materials) to generate intense localized magnetic fields. These composite magnetic components provide high magnetic lifting force in compact form, enabling small drum size while achieving the necessary magnetic attraction strength
4Productivity
If drum rotation rate is increased to match scale generation, then continuous filtration is achieved, but scale removal by scraper becomes more difficult
Solution Approach 1:
The patent creates local quality differences in the magnetic field along the drum rotation path. The magnetic circuit is designed so that the magnetic field strength varies with position: strong field during the collection phase and weak field during the discharge phase, enabling the drum to both capture scale at high rotation rates and release it to the scraper
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 solution enables continuous, efficient removal of mill scale, reducing downtime and maintenance costs, and allowing for the collection and recycling of scale as it is generated, while maintaining equipment integrity and improving tooling life.
Implementation Method 1
a magnetic drum rotating within a tank and having a magnetic field for attracting and retaining the mill scale on the drum
Implementation Method 2
both the iron and magnetite particles are ferromagnetic
Implementation Method 3
means for generating bubbles within the tank and adjacent the rotatable magnetic drum to attach the bubbles to the mill scale
Data Source
AI summary
A method and apparatus for continuous magnetic filtration of ferrous mill scale from liquid solution employs a tank for receipt of fluids laden with mill scale. A curvate trough within the tank receives a rotatable magnetic drum and establishes a channel therebetween. An air compressor and associated manifold generate bubbles within the tank and adjacent the rotatable magnetic drum. The mill scale attaches to the bubbles, which are attracted to the surface of the drum where the mill scale accumulates. The accumulation of mill scale particles is moved about the surface of the rotating drum by a scraper proximate the surface thereof. By moving the accumulated mill scale particles to regions of the rotating drum that are of a magnetic force insufficient to retain them upon the surface of the drum, the mill scale particles are removed and passed to a conveyor system.