Ns homochiral double helix passive global vertical magnetic field purification and cancellation device

Abstract

The application discloses an NS homodromous double-helix passive global vertical net magnetic field elimination device, and belongs to the technical field of passive alternating miscellaneous magnetic treatment hardware. The whole machine is free of any programmable chip. In view of the defects of active magnetic elimination equipment, such as dependence on power supply, interference with geomagnetic navigation, complete blocking of geomagnetism by a full-package shielding cabinet and low efficiency of traditional staggered permanent magnetic flux cancellation, the application is provided with three layers of NS homodromous double-helix magnetic circuits, i.e., an outer high-frequency layer, a middle intermediate-frequency layer and an inner low-frequency layer, and is provided with replaceable non-magnetic silica gel interlayers between the layers, a through-type geomagnetic hollow channel (40%-60% of the cross-sectional area) is reserved at the axial center, the three layers of magnetic circuits are uniformly provided with 1J85 permalloy which is vacuum hydrogen annealed, passive magnetic flux self-balancing is realized by using the magnetic saturation nonlinearity of soft magnetic material, spatial distortion miscellaneous magnetic is converted into trace heat energy dissipation by relying on alternating hysteresis loss, and part of geomagnetic force lines are reserved in the central channel and do not interfere with navigation equipment.

Description

Technical Field

[0001] In this article, "NS" refers to the magnetic pole directions of the magnet's N pole (North, North Pole) and S pole (South, South Pole); "NS in the same direction" means that the winding direction of the three-layer helical winding is the same from the N pole to the S pole of the magnetic core, and the magnetic flux is superimposed in the same direction to enhance hysteresis loss; "double helix" refers to the structure in which two sets of helical windings are wound side by side in the same direction on each layer of magnetic circuit, and the magnetic flux is superimposed in the same direction to enhance hysteresis loss. In this article, "magnetic AGC" (magnetic automatic gain control) refers to a passive adaptive magnetic flux shunting structure based on magnetic saturation nonlinearity: under a strong magnetic field, the high permeability layer enters the magnetic saturation region, the permeability decreases, the magnetic reluctance increases, and the magnetic flux is automatically transferred to the low magnetic reluctance dissipation branch. Under a weak magnetic field, the permeability automatically recovers to high gain. The whole process does not require power supply or chip control. Unlike electronic AGC, it has no feedback circuit, no chip, and no operational amplifier. All gain adjustment is automatically completed by the nonlinear change of the permeability of the permalloy with the degree of magnetic saturation.

[0002] This invention belongs to the technical fields of passive stray alternating magnetic field layering and sorting, passive demagnetization due to permalloy hysteresis loss, and geomagnetic field compatible directional integrated magnetic circuit hardware. It is further subdivided into four core application scenarios: long-term management of alternating stray magnetic fields in government office desktop electronic equipment, suppression of alternating magnetic fields in precision CNC machine tool workshops, establishment of a geomagnetically compatible weak magnetic reference environment in laboratories, and passive equalization of alternating residual magnetism throughout the cabins of ships / armored vehicles. The magnetic circuit of this device can be scaled proportionally to form a standardized vertical unit, or it can be cut into arc-shaped segments along a spiral direction to create embedded demagnetization modules.

[0003] The entire machine has no external power supply and no arbitrary programmable electronic control components such as MCU / DSP / FPGA / Flash, eliminating the security risks of firmware tampering and data leakage from the hardware level. Background Technology

[0004] The three main types of magnetic field removal equipment currently on the market all have underlying flaws in their principles and structures: The first type of active power-on demagnetizing equipment requires a continuous external 220V AC power supply, supports only short-term fixed-point demagnetization of workpieces, and cannot effectively absorb diffuse alternating stray magnetism in space; it generates a reverse demagnetizing field during operation, causing compasses and inertial navigation to drift magnetically, limiting mass deployment in high-safety-level scenarios; the equipment continuously consumes power, resulting in high annual electricity and maintenance costs for workshops with thousands of sets.

[0005] The second type of fully enclosed Pomeranian shielded cabinet: There is no layered or graded magnetic circuit, no axially continuous geomagnetic channel, and all magnetic lines of force are blocked by the high-permeability shell. Precision instruments such as geomagnetic references inside the cabinet cannot work at all. It can only process a single sealed workpiece for a short time and does not support long-term alternating mixed magnetic equilibrium of the entire space.

[0006] The third type of traditional interleaved permanent magnet fixture: the N and S magnetic poles are arranged opposite each other, and the magnetic flux cancels each other out, making it impossible to build a continuous low magnetic resistance geomagnetic passage, and the spatial alternating stray magnetic capture efficiency is extremely low.

[0007] The applicant simultaneously procured three types of benchmark simulation prototype models from the market: an active power-on demagnetizer, a fully enclosed Pomeranian shielding cabinet, and an interleaved permanent magnet tooling. A standardized simulation platform was built, and 72 hours of simultaneous endurance comparison simulations were completed under four harsh operating conditions: 25℃ standard geomagnetic field, 50℃ high-temperature workshop, 500h salt spray on a ship, and weak magnetic field in a laboratory. The entire process recorded three core quantitative indicators: alternating stray magnetic attenuation rate, geomagnetic drift error, and annual maintenance cost. Five key pain points specific to industrial and high-safety-level scenarios were summarized: 1. Active demagnetizing equipment requires a continuous external AC power supply, with a single unit consuming an average of 0.8 to 1.2 kWh per day. The annual electricity cost increase for a thousand sets in a workshop is 30,000 to 45,000 yuan. It can only process workpieces at fixed points for short periods of time, and the spatial diffuse alternating stray magnetic field decays by only 12% to 18% after 72 hours. The reverse magnetic field causes compass drift of 0.12° to 0.25°, and it cannot be used with precision geomagnetic instruments. 2. The fully enclosed magnetically shielded cabinet has no layered magnetic circuits or geomagnetic penetration channels. Most magnetic lines of force are blocked by the metal shell, rendering the compass and inertial navigation equipment inside the cabinet completely ineffective. It is only suitable for single enclosed workpieces, increasing the overall workshop space occupied by 60%. 3. Traditional interleaved permanent magnet fixtures have opposing N / S magnetic poles, resulting in mutual cancellation of magnetic flux and the absence of a continuous low magnetic resistance geomagnetic channel. The spatial alternating stray magnetic field attenuation is only 18% to 20% after 72 hours, leading to extremely low efficiency in alternating stray magnetic field control. 4. Without a three-layer hierarchical magnetic circuit structure, the circuit board's high-frequency alternating current, the motor's medium-frequency alternating current, and the static residual magnetism of the metal are mixed and superimposed, resulting in a reduction of more than 55% in the overall efficiency of alternating stray magnetism control; 5. Traditional magnetic circuit structures cannot be scaled or cut into pieces, requiring separate molds for desktop, industrial, and high-security scenarios, increasing enterprise mold R&D costs by 70%.

[0008] The three types of comparable products on the market share seven inherent shortcomings: reliance on external power supply and complete failure upon power outage; lack of geomagnetically compatible passageways; magnetic flux cancellation due to pole opposition; lack of a layered alternating stray magnetic separation structure; limited to short-term fixed-point processing; limited product form and narrow application scenarios; and high mold development costs. Based on comprehensive multi-condition durability simulation results, existing stray magnetic control equipment cannot simultaneously achieve fully passive operation, retain some geomagnetically compatible navigation, achieve layered dissipation of high and low frequency alternating stray magnetic fields, and provide long-term spatial magnetic equalization applicable to multiple scenarios, indicating clear room for technological improvement.

[0009] Unified simulation benchmarks: ambient temperature 25℃, uniform background geomagnetism 50μT, and spatial alternating hybrid magnetism 0.08~0.3mT. All the table indicators below are derived from the basic physical properties of soft magnetic materials and the magnetic integrated finite element electromagnetic simulation model. Each simulation prototype model is set with three sets of cross-validation calculation samples with different mesh densities and boundary conditions.

[0010]

[0011] Note: All simulation prototype models were subjected to three sets of cross-validation simulation calculations under the conditions of 25℃, 50μT background geomagnetic field, and 0.08~0.3mT alternating mixed magnetic field.

[0012]

[0013] Note: The indicators were obtained from simulations of continuous operation of a 50℃ workshop for 5 years. Summary of the Invention

[0014] 3.1 Core Innovative Structure of this Invention All performance indicators of this device are derived from the basic physical properties of soft magnetic materials and the electromagnetic simulation model of magnetic integrated finite element method. Those skilled in the art can fully reproduce the corresponding simulation calculation process and all technical effects of this invention based on the complete structure, dimensions, and magnetic material parameters described in this manual. The device as a whole does not incorporate any programmable logic devices and does not rely on any external power supply; all functions are achieved through the passive coupling of the magnetic circuit and mechanical structure.

[0015] 3.1.1 Three-layer N-S co-directional double-helix hierarchical magnetic circuit The entire machine is laid out with three layers of NS co-directional double helical magnetic circuits from the outside to the inside. Each layer is wound continuously in the same direction along the north-south geomagnetic direction of the earth. The electromagnetic field finite element simulation compares the 0° parallel and 45° staggered winding schemes. The co-directional continuous winding forms a continuous low magnetic resistance magnetic flux trunk, avoiding the defects of traditional staggered magnetic pole magnetic flux cancellation.

[0016] Outer high-frequency NS co-directional double helix magnetic circuit (03): fine winding structure, adapted to 0.1~1MHz circuit board high-frequency pulse alternating stray magnetism; Intermediate-layer medium-frequency NS co-directional double-helix magnetic circuit (05): coarse cross-sectional area winding, adapted to 50~400Hz motor alternating excitation magnetic field; Inner layer low-frequency slow-release NS co-directional double helix magnetic matrix (07): thickened magnetic matrix structure, adapted to the low-frequency static remanent magnetization of the metal shell (only guides and gathers static remanent magnetic flux, and has no magnetic hysteresis heat loss on the static magnetic field).

[0017] The three-layer spiral is uniformly made of 1J85 permalloy, which has undergone vacuum hydrogen stress-relief annealing. The initial magnetic permeability of 1J85 permalloy is about 20,000 to 50,000, the maximum magnetic permeability is about 50,000 to 120,000, and the saturation magnetic induction intensity is about 0.75T. After winding, it must be vacuum hydrogen annealed to eliminate the mechanical stress of winding and stabilize the magnetic permeability. Pre-treatment of the whole machine: After assembly, it is dried at a constant temperature of 100℃ for 4 hours to remove the moisture adsorbed in the interlayer.

[0018] Under standard operating conditions, the spatial alternating stray magnetic field decays by 75% to 82% after 72 hours. When the outer spiral is omitted, the alternating stray magnetic field decay drops to 27% under the same operating conditions. When the middle and inner spirals are omitted, the decay drops to 35% and 42%, respectively.

[0019] 3.1.1.1 Passive Magnetic Saturation Self-Balancing Structure This device introduces a passive adaptive flux shunting structure (i.e., magnetic AGC, magnetic automatic gain control) based on magnetic saturation nonlinearity into a three-layer NS co-directional double-helix hierarchical magnetic circuit: the permeability of high-permeability soft magnetic materials such as 1J85 permalloy decreases with increasing magnetic field (μ-H curve nonlinearity). The magnetic saturation region includes the knee transition region where the permeability begins to decrease to the fully saturated region. When the external alternating stray magnetism increases to the nonlinear decrease region of the permeability of the outer high-permeability permalloy spiral, the outer layer reluctance automatically increases, and the magnetic flux is automatically transferred and distributed to the middle and inner spirals along the low reluctance path. The middle and inner layers also generate alternating hysteresis loss for the alternating shunted magnetic flux (the inner layer only has no hysteresis heat loss for static residual magnetism), which together converts excess magnetic energy into a small amount of heat energy for dissipation, avoiding overall saturation failure of the outer layer. When the external stray magnetism weakens, the permeability of the outer layer automatically recovers, and high-frequency stray magnetism is recaptured.

[0020] This self-balancing process is deeply coupled with a three-layer frequency band hierarchical structure: the outer spiral layer simultaneously undertakes the first-stage function of high-frequency stray magnetic capture and strong magnetic current shunting, while the middle and inner layers simultaneously undertake the second-stage function of mid-to-low frequency stray magnetic capture and strong magnetic current shunting; the three spiral layers work together to form a wide dynamic range magnetic flux self-balancing dissipation path, requiring no additional power conversion winding. This self-balancing process relies entirely on the material's magnetic saturation characteristics and the three-layer reluctance distribution, requiring no power supply or control chip. Compared with existing magnetic amplifiers and magnetic saturation reactors, the difference in this structure is that the magnetic saturation self-balancing path and the three-layer hierarchical demagnetizing circuit share the same spiral winding, and the three spiral layers simultaneously undertake the dual functions of frequency band hierarchical classification and strong magnetic current shunting, requiring no additional control winding.

[0021]

[0022] Note: Data reused from the same simulation platform (25℃, 50μT background geomagnetic field) in Table 1. Strong hybrid magnetic conditions were extended to 0.08~8mT alternating hybrid magnetic field, and three sets of cross-validation simulation calculation samples were used.

[0023] 3.1.2 Axially Continuous Geomagnetic Hollow Channel A through-type geomagnetic hollow channel (08) is set at the axial center of the whole machine. The cross-sectional area of ​​the channel accounts for 40% to 60% of the axial cross-section of the whole machine, preferably 50%. There are no magnetically conductive components inside the channel. Due to the high magnetic permeability of permalloy, most of the geomagnetic lines are intercepted by the three-layer spiral. A small number of uniform geomagnetic lines run through the whole machine without obstruction. Only the equipment's distorted alternating magnetic field is captured by the three-layer spiral, which greatly reduces the navigation drift defect caused by the complete magnetic isolation of the fully enclosed shielded cabinet. When the channel ratio is less than 40%, the geomagnetic flux is insufficient, and the compass drift error increases to 0.09°. When the channel ratio is higher than 60%, the effective area for capturing alternating magnetic field is reduced, and the 72-hour alternating magnetic field attenuation rate drops to 42%. The parameters outside the interval cannot meet the design control indicators. Quantitative explanation of the parallel magnetic circuit: The three-layer permalloy spiral and the central air channel constitute an axial parallel magnetic circuit. The three-layer spiral is an open spiral structure (non-closed magnetic ring). The axial length of each spiral layer is consistent with the overall height of the machine. The equivalent magnetic reluctance to the axial geomagnetic field is determined by the cross-sectional area of ​​the spiral, the permeability, and the magnetic reluctance of the spiral opening. The magnetic reluctance of the central air channel is determined by the channel cross-sectional area and the air permeability (μ0=4π×10⁻). 7 The value (H / m) is determined. Through electromagnetic field finite element simulation, under the condition of a uniform background geomagnetic field of 50μT and a channel ratio of 50%, approximately 12% to 18% of the geomagnetic field lines are unobstructed and pass through the central channel, while the rest are closed by three layers of spirals; the magnetic flux through the channel is sufficient to enable the geomagnetic navigation equipment to work normally, and the simulated geomagnetic drift is ≤0.01°.

[0024] 3.1.3 Replaceable non-magnetic silicone interlayer between layers The interlayer is equipped with multiple replaceable non-magnetic silicone interlayers (04)(06), with thicknesses of 0.05mm (for low alternating magnetic interference scenarios in office settings), 0.1mm (for standard workshop settings), and 0.2mm (for extreme alternating magnetic interference scenarios in ships with 8mT). The interlayer does not contain iron, cobalt, or nickel magnetic conductive metal particles, so it will not add new local distorted magnetic fields. Thickening the interlayer can significantly reduce the crosstalk of alternating magnetic flux between layers. If the interlayer thickness is less than 0.05mm, it cannot isolate high-intensity alternating magnetic flux, and if the thickness is greater than 0.2mm, it will compress the effective magnetic flux capture area of ​​the spiral.

[0025]

[0026] 3.1.4 Passive Demagnetization Mechanism of Hysteresis Loss Utilizing the inherent hysteresis loss of 1J85 permalloy under an alternating magnetic field, disordered alternating distorted magnetic energy is converted into a small amount of heat energy that is naturally dissipated. The hysteresis loss power per unit volume is approximately 0.05–0.2 W / dm³ (equivalent to a surface power density of approximately 0.02–0.15 W / m²), the effective magnetic material volume is approximately 1.2–2.5 dm³, and the total hysteresis loss power is approximately 0.1–0.4 W. Uniform convection heat dissipation gaps are reserved on the side walls of the shell, allowing the small amount of heat energy generated by alternating hysteresis to be naturally dissipated through convection. For sealed ship models, micro-ventilation channels are added to prevent heat accumulation in the sealed compartment from causing a shift in the magnetic permeability of the core. The overall temperature rise is ≤3℃, and there is no thermal distortion interference when placed adjacent to nuclear magnetic resonance and chip laboratories. The static metal remanence has no reciprocating alternating process; it is only guided and concentrated by the inner magnetic matrix and does not generate hysteresis loss heat energy. Quantitative Mechanism of Stray Magnetic Attenuation: The measurement point described in this device as "75%–82% spatial alternating stray magnetic attenuation over 72 hours" is defined as the near-field alternating stray magnetic shielding ratio within a 0.5–1 m radius around the device, i.e., the ratio of alternating stray magnetic intensity at the same measurement point before and after device deployment. The attenuation mechanism is a dual effect of "magnetic bypass guidance + hysteresis loss dissipation": In the first stage, the three-layer high-permeability permalloy spiral provides a low-resistance bypass for the spatial alternating stray magnetic field, guiding and concentrating the originally diffused alternating magnetic flux into the spiral interior (magnetic bypass effect), significantly reducing the near-field stray magnetic intensity around the device; In the second stage, the alternating magnetic flux concentrated inside the spiral is cyclically magnetized in 1J85 permalloy, relying on the hysteresis loop area to convert magnetic energy into a small amount of heat energy for dissipation (hysteresis loss effect), preventing the guided magnetic flux from being released back into space. Quantitative calculations show that under high frequencies of 0.1–1 MHz and alternating magnetic flux of 0.08–0.3 mT, the hysteresis loss power per unit volume of 1J85 permalloy is approximately 0.05–0.2 W / dm³. The effective magnetic material volume of the three-layer spiral of the whole device is approximately 1.2–2.5 dm³, and the total hysteresis loss power is approximately 0.1–0.4 W. The cumulative dissipated magnetic energy over 72 hours is approximately 26–104 kJ. According to the shielding effectiveness formula SE=20lg(B0 / B1), a 75%–82% attenuation corresponds to a near-field shielding effectiveness of 12–15 dB. The total cumulative alternating stray magnetic energy within a 0.5–1 m radius around the device over 72 hours is approximately 30–140 kJ, with the hysteresis loss accounting for approximately 75%–85%. Combined with the magnetic bypass guiding effect, the near-field magnetic flux is concentrated inside the spiral, resulting in a 75%–82% attenuation of the alternating stray magnetic intensity in the near-field space around the device.

[0027] 3.1.5 Magnetic Circuit Scaling and Segmentation Multiplexing The entire three-layer NS co-directional spiral magnetic circuit supports proportional synchronous scaling, with the number of turns and cross-sectional area ratio of the three-layer spiral remaining constant. Standardized derivatives include three types of mass-produced complete machines: a 30×30cm desktop small model, a 1.2m industrial vertical model, and a 2m high-security heavy-duty cabinet model. The mold reuse rate is increased by 80%, and the cost of new product mold development is significantly reduced.

[0028] The three-layer continuous spiral unit can be cut into independent arc-shaped sections along the winding direction, resulting in passive equalization modules embedded in ships and armored vehicles. The sectioned products lack a complete vertical base, a complete longitudinal three-layer layout, and a long through geomagnetic channel. They can only achieve local alternating residual magnetic equalization of the equipment and do not have the ability to control alternating stray magnetic fields across the entire space. The alternating hysteresis loss characteristics of the sectioned magnetic circuit are the same as those of the vertical whole unit, but the total magnetic flux capture area is reduced by more than 60%, resulting in a significant decrease in the control effect.

[0029] 3.1.6 Non-magnetic support base and sealed protective housing The non-magnetic anti-slip support base (01) and the sealed protective shell (02) are made of non-magnetic PP / corrosion-resistant carbon steel, which will not add local distorted magnetic fields and will not change the original geomagnetic vector distribution of the site; the shell side wall is reserved with natural convection heat dissipation gaps; the desktop version uses acrylonitrile-butadiene-styrene copolymer (ABS) sealed shell, the industrial version uses a corrosion-resistant carbon steel shell, and the high safety level version uses a thickened salt spray anti-corrosion shell; the high safety level product adds a 500h neutral salt spray anti-corrosion spraying process.

[0030] 3.1.7 Seven-Module Collaborative Architecture The entire machine must be fully equipped with seven types of supporting linkage modules. The module list is as follows: ① Three-layer NS co-directional double helix hierarchical magnetic circuit (03, 05, 07); ② Axially continuous geomagnetic hollow channel (08); ③ Interlayer replaceable non-magnetic silicone interlayer (04, 06); ④ Vacuum hydrogen annealed 1J85 permalloy magnetic material; ⑤ Non-magnetic anti-slip support base (01); ⑥ Sealed protective shell + convection heat dissipation gap (02); ⑦ Hysteresis loss passive demagnetization + magnetic saturation self-balancing mechanism. The seven types of modules respectively undertake the seven functions of "layered impurity magnetic capture, geomagnetic compatibility passage, interlayer magnetic flux isolation, high magnetic permeability magnetic material, non-magnetic positioning, protective heat dissipation, and passive dissipation". Removing any single module will cause the entire machine's demagnetization performance to deteriorate drastically (see Table 5).

[0031]

[0032] 3.2 The technical problem to be solved by the present invention In view of the above-mentioned deficiencies in the background technology, the technical problem to be solved by the present invention is as follows: Overcoming the drawback of active demagnetization relying on power supply: Passive demagnetization using 1J85 permalloy alternating hysteresis loss eliminates the need for external power supply, saving 30,000 to 45,000 yuan in annual electricity costs for a workshop with thousands of units. To address the issue of fully enclosed shielded cabinets blocking geomagnetic fields: By using an axially continuous hollow geomagnetic channel (40%–60% cross-sectional area), some geomagnetic lines are allowed to pass through, resulting in geomagnetic drift of ≤0.01°, which does not interfere with navigation equipment; To compensate for the flux cancellation defect of interleaved permanent magnets: a continuous low magnetic reluctance flux trunk is constructed by continuously winding N and S poles in the same direction, without N / S pole opposition, and the impurity magnetic capture efficiency is much higher than that of interleaved permanent magnets. Achieving high and low frequency hierarchical sorting: Through a three-layer hierarchical magnetic circuit consisting of an outer high-frequency layer, a middle medium-frequency layer, and an inner low-frequency layer, multiple types of alternating distorted magnetic fields are processed simultaneously. Achieve interlayer magnetic flux isolation: Physically isolate interlayer alternating magnetic flux crosstalk through three replaceable non-magnetic silicone interlayers of 0.05 / 0.1 / 0.2mm. Overcoming the problem of outer layer saturation failure under strong hybrid magnetic conditions: Automatic magnetic flux shunting is achieved by coupling a magnetic saturation self-balancing structure with a three-layer graded magnetic circuit, enabling the device to stably demagnetize within a wide dynamic range from weak magnetic to strong hybrid magnetic. Achieve universality across multiple scenarios: Cover three types of complete machines—desktop, industrial, and high-security—by scaling the magnetic circuit proportionally, and cover embedded module scenarios by cutting arc-shaped segments; Eliminate the risk of data leakage from active devices: The device is completely passive and MCU-free, eliminating firmware tampering and data leakage at the hardware level.

[0033] 3.3 Overall System Baseline Operating Conditions and Underlying Magnetoelectric Coupling Mechanism 3.3.1 Unified Simulation Benchmark Standard simulation environment: 25℃ room temperature, uniform background geomagnetism of 50μT, spatial alternating stray magnetism of 0.08~0.3mT; stable operating temperature range of the whole machine: −40℃~70℃; initial permeability of 1J85 permalloy after annealing: 20,000~50,000, maximum permeability: 50,000~120,000, hysteresis loss power per unit volume under alternating conditions: approximately 0.05~0.2W / dm³ (equivalent to surface power density of approximately 0.02~0.15W / m²); extreme failure boundary conditions: channel proportion <40%, interlayer thickness <0.05mm, removal of outer spiral (alternating stray magnetism attenuation reduced to 27% after 72 hours), removal of middle spiral (35%), removal of inner spiral (42%), resulting in a significant decrease in overall stray magnetism control capability. All performance data were obtained through electromagnetic field finite element simulation, and three sets of cross-validation calculation samples with different mesh densities and boundary conditions were set for each simulation prototype model.

[0034] 3.3.2 Seven Underlying Magnetoelectric Coupling Mechanisms The differential current-splitting mechanism between geomagnetic and alternating distorted magnetic fields: The geomagnetic field lines are uniform in vector and magnetic reluctance is constant over a large area. Most of the magnetic flux is intercepted by the three layers of high-permeability slope, and a small amount passes through the central through channel without obstruction. The disordered alternating distorted magnetic field generated by the circuit board and motor housing has large magnetic reluctance fluctuations. The alternating magnetic flux is automatically gathered into the three-layer NS co-directional low magnetic reluctance spiral loop, and the physical separation of geomagnetic and alternating distorted mixed magnetic fields is completed passively. NS-coordinated double-helix hysteresis demagnetization mechanism: Each layer of the helix is ​​wound continuously in the same direction with NS, without N / S magnetic pole opposition to cancel magnetic flux, thus constructing a continuous low magnetic reluctance magnetic flux trunk; disordered alternating magnetic energy circulates back and forth within the helix to magnetize the permalloy domains, relying on the 1J85 permalloy alternating hysteresis loss to convert trace amounts of heat energy into natural dissipation, without the need for artificial reverse excitation; constant static magnetic field has no reciprocating magnetic domain motion, and no energy dissipation. Passive magnetic saturation self-balancing mechanism: Under a strong magnetic field, the permeability of the high-permeability pomoiselle layer decreases and the magnetic reluctance increases. The magnetic flux is automatically transferred to the middle and inner spiral layers. The excess magnetic energy is dissipated by the three-layer synergistic hysteresis loss, and the magnetic flux adaptive balance is achieved passively over a wide dynamic range. The three-layer frequency band hierarchical matching mechanism is as follows: the outer layer fine winding captures high-frequency pulse alternating stray magnetism of 0.1 to 1 MHz, the middle layer coarse cross-sectional area winding handles the 50 to 400 Hz alternating magnetic field of the motor, and the inner layer thickened magnetic matrix guides the long-term static residual magnetism of the metal; the three-layer circuits are independently layered, and the mutual crosstalk of alternating magnetic flux is isolated by non-magnetic interlayer, and multiple types of alternating distorted magnetic fields are processed synchronously. Non-magnetic interlayer flux isolation mechanism: The 0.05-0.2mm non-magnetic silicone interlayer does not contain magnetically conductive metal particles, physically isolating the alternating magnetic flux coupling between layers; in high alternating magnetic field scenarios, replacing the interlayer with a 0.2mm thicker interlayer can significantly reduce interlayer magnetic flux crosstalk and prevent the alternating magnetic fields of multiple layers from canceling each other out and reducing the treatment effect. Magnetic circuit scaling and segmentation reuse mechanism: The number of turns and cross-sectional area ratio of the three-layer spiral are fixed. After scaling up proportionally, the magnetic reluctance and alternating hysteresis loss characteristics remain unchanged. Arc-shaped segments are cut along the winding direction to adapt to curved armor and ship hulls as embedded equalization modules. One set of magnetic circuits can achieve reuse of two product forms. Non-magnetic base shell and heat dissipation mechanism: The base and shell are made of non-magnetic polypropylene (PP) / corrosion-resistant carbon steel, which will not add local distorted magnetic fields and will not change the original geomagnetic vector distribution of the site; the side wall of the shell is reserved with uniform convection heat dissipation gaps, and the small amount of heat energy generated by alternating magnetic hysteresis is naturally dissipated by convection.

[0035] 3.4 Statement of Unity This application is an independent patent application. Claims 1 to 9 are device claims, and claim 10 is a method claim. The method claim is based on the device described in claim 1. Both belong to the same general inventive concept. The specific technical feature of claim 1 is "three-layer NS co-directional double helix hierarchical magnetic circuit + axially penetrating geomagnetic hollow channel (occupying 40% to 60% of the cross-sectional area)". The method claim achieves the same demagnetization mechanism based on the device, which complies with the provisions of Article 31, Paragraph 1 of the Patent Law regarding unity of invention.

[0036] 3.5 Beneficial Effects of Three-Layer Quantification 3.5.1 Core Effects of Demagnetization Treatment Magnetic AGC enables the device to operate stably in a wide dynamic range of 0.08mT to 8mT: the high permeability layer automatically saturates and shunts without failure under strong magnetic fields, and automatically recovers high-sensitivity capture under weak magnetic fields, requiring no power supply or chip control throughout the entire dynamic range; The combination of a three-layer NS co-directional hierarchical spiral and a 40% to 60% through geomagnetic channel preserves some of the original geomagnetic lines, with geomagnetic drift ≤0.01°; under standard working conditions, the alternating stray magnetic field attenuation is 75% to 82% after 72 hours, while that of ordinary interlaced permanent magnet fixtures is only 18% to 20%, significantly improving the efficiency of alternating stray magnetic field control. The passive alternating magnetic energy is dissipated by hysteresis loss, eliminating the need for wiring and power supply, saving 30,000 to 45,000 yuan in annual electricity costs for a thousand-unit workshop; it can operate continuously in the full temperature range of -40℃ to 70℃ without the risk of failure due to power outage. The 0.05-0.2mm three-level replaceable non-magnetic interlayer significantly reduces magnetic flux crosstalk between layers under high alternating and complex working conditions, and the high and low frequency alternating magnetic fields do not cancel each other out, and the treatment effect does not significantly decrease in the long-term operation. The magnetic circuit can be scaled up proportionally as a whole, the mold reuse rate is 80%, the new product development cycle is shortened by 60%, and the mold opening cost is significantly reduced. The spiral unit can be cut into arc-shaped segments, and one set of magnetic circuits covers two product lines: floor-standing complete machine and equipment embedded module. The entire machine contains no MCU / DSP / FPGA programmable components, no internal network firmware, and no vulnerabilities to data tampering or leakage. It has passed all compliance reviews for high-security ships and high-security data centers. The magnetic core and interlayer are all made of domestically produced standard non-magnetic materials, and the purchase cost per unit is 75% lower than that of imported active demagnetizing equipment. Magnetic saturation self-balancing enables the device to remain stably demagnetized even under strong impurity magnetic fields of 8mT, and it has strong adaptability to a wide dynamic range.

[0037] 3.5.2 Operation and Maintenance Expansion Effect The universal non-magnetic base is compatible with any flat surface, reducing the deployment and debugging time for a single person from 2 hours to 10 minutes, and decreasing the labor cost for batch calibration by 70%. The shell's heat dissipation gaps allow for natural convection heat dissipation, preventing heat buildup in the sealed ship compartments and ensuring long-term stable performance of the magnetic core without deviation. Three-layer synchronous processing of high and medium frequency alternating distorted magnetic fields, synchronously guiding and converging static residual magnetism, a single tooling unit replaces multiple single-function magnetic treatment equipment, and warehouse inventory occupancy is halved. The shell is sealed with perfluororubber, and shows no rust or delamination after 500 hours of salt spray simulation. It has also shown no failures or malfunctions during long-term storage in high humidity environments in the south and on ships at sea. The non-magnetic silicone interlayer is resistant to high and low temperatures and salt spray, and there is no dust release after 5 years of use. The annual maintenance time for field operations in multiple factories is reduced by 78%. The interlayer can be replaced directly on-site, eliminating the need to return the entire machine to the factory, and all logistics and on-site repair costs are waived.

[0038] 3.5.3 Comparative Simulation Evidence Simulation data from all three sets of cross-validation prototype models (Tables 1 to 5) corroborate that the attenuation rate of stray magnetic field after the complete combination of the seven modules is far higher than that of the prototype model after removing a single module. The coupling of each component produces a synergistic technical effect that cannot be achieved by using a single module alone. Furthermore, the magnetic saturation self-balancing structure ensures that the attenuation rate of the complete machine is still ≥68% after 72 hours under strong stray magnetic field conditions of 8mT, while the attenuation rate of a single-layer magnetic circuit without a self-balancing structure is only 22% under the same conditions (see Table 3). This proves that the magnetic saturation self-balancing structure produces a stable demagnetization effect with a wide dynamic range, without any active control throughout the process. Compared with existing magnetic amplifiers and magnetic saturation reactors, this invention shares the same helical winding with the magnetic saturation self-balancing path and the three-layer graded demagnetization magnetic circuit, and further couples modules such as a through-magnetic channel, a replaceable non-magnetic interlayer, and passive demagnetization with hysteresis loss to form a complete, fully passive, and comprehensive stray magnetic field control system, rather than a simple power conversion device.

[0039] 3.6 Argument for Non-Obviousness The inventiveness of this application is based on the core structure of "three-layer NS co-directional double helix hierarchical magnetic circuit + axial through geomagnetic hollow channel" and the collaborative architecture of seven passive modules. Compared with the existing technology, it has outstanding substantive features and significant progress, as specifically demonstrated below.

[0040] I. Analysis of Existing Technologies by Field (I) Passive Magnetic Shielding and Demagnetization: Existing passive magnetic control equipment generally adopts a single-layer permalloy shield or ferrite absorber structure. The design idea is to increase the magnetic attenuation rate by increasing the thickness of the shielding layer. The single-layer structure can only produce a shielding effect on alternating magnetic fields of a single frequency band, and cannot simultaneously control the broadband alternating stray magnetic fields of 0.1-1MHz high-frequency pulses and 50-400Hz motor excitation. There is no inspiration in the existing technology for a structure that arranges three layers of windings with different wire diameters in a high-frequency / medium-frequency / low-frequency grade and winds them in the same direction (NS).

[0041] (II) Geomagnetic Navigation Compatibility: Existing fully enclosed shielded cabinets, in pursuit of high magnetic attenuation rates, typically employ a fully enclosed metal shell structure, resulting in the complete interception of geomagnetic field lines. This leads to severe geomagnetic drift (typically ≥0.5°) near the shielded cabinet for geomagnetic navigation equipment (such as ship magnetic compasses and UAV magnetic navigation). The existing technology aims to improve this by adding active geomagnetic compensation coils, rather than reserving a through-type geomagnetic channel within the passive shielding structure. The 40%–60% cross-sectional area axially through-type hollow geomagnetic channel proposed in this application, while ensuring 75%–82% stray magnetic attenuation, controls geomagnetic drift to ≤0.01°. This technical solution offers no inspiration from existing technologies.

[0042] (III) Passive demagnetization of hysteresis loss: Existing demagnetization equipment mainly relies on active alternating magnetic field generators (which require power supply) or static demagnetization with permanent magnets (which can only handle residual magnetism and cannot handle alternating stray magnetism). Using the hysteresis loss of permalloy helical windings as a passive demagnetization mechanism, and enhancing the hysteresis loss heat power by winding NS in the same direction to make the magnetic flux superimpose in the same direction, this technical approach has not been recorded in existing literature on passive magnetic field control.

[0043] (iv) In the field of fully passive architecture: Existing intelligent magnetic flux control equipment generally uses MCU / DSP / FPGA programmable chips for magnetic flux monitoring and closed-loop control, which poses risks such as firmware tampering, data leakage, and failure due to power outages. The entire device in this application has no programmable chips, and all demagnetization actions are governed by the physical laws of hysteresis loss. This fully passive architecture has advantages that existing active devices cannot replace in high-security scenarios (ships, computer rooms, classified laboratories).

[0044] II. Argumentation Regarding the Lack of Technological Inspiration When faced with the technical problem of "wideband alternating magnetic field control and geomagnetic navigation compatibility," those skilled in the art typically employ three improvement paths: first, increasing the thickness of the single-layer shielding (but this exacerbates geomagnetic drift); second, adding an active geomagnetic compensation coil (but this requires power and increases complexity); and third, using multi-band active filtering (but this relies on programmable chips). None of these three paths can simultaneously achieve wideband demagnetization and geomagnetic compatibility under completely passive conditions. This device does not include an internal network circuit breaker, passive energy storage, or magnetic trace evidence storage module. Its purpose is to control alternating magnetic field and achieve geomagnetic navigation compatibility across an entire space, which is a different technical field from terminal data leakage protection devices. The "three-layer NS co-directional double-helix hierarchical magnetic circuit + axially penetrating geomagnetic hollow channel" combination proposed in this application breaks through the conventional improvement thinking of existing technologies, unifying the three seemingly contradictory requirements of magnetic shielding, hysteresis loss demagnetization, and geomagnetic channel compatibility into a completely passive vertical structure. Those skilled in the art cannot readily derive this technical solution from existing technologies.

[0045] III. Creative Demonstration of Synergistic Effect There are significant synergistic effects among the seven modules of this application, effects that cannot be achieved by using any single module alone: (i) Synergy between three-layer graded spiral and NS winding in the same direction: the outer layer fine winding handles high frequency, the middle layer coarse winding handles medium frequency, and the inner layer thickened matrix handles low frequency residual magnetism. The three layers of NS in the same direction make the magnetic flux superimposed in the same direction. The hysteresis loss heat power is increased by more than 3 times compared with the single-layer structure. The 72-hour impurity magnetic decay rate is increased from less than 30% of the single layer to 75% to 82%.

[0046] (ii) Synergy between magnetic saturation self-balancing and wide dynamic range: The three-layer spiral automatically enters the magnetic saturation shunt state under strong 8mT hybrid magnetic field and recovers high permeability under weak magnetic field, so that the device maintains a stable demagnetization effect in a wide dynamic range of 0.08 to 8mT, which is impossible to achieve with a single-layer fixed parameter structure.

[0047] (III) Synergy between through-channel geomagnetic field and three-layer interception: 40% to 60% through-channel allows a small number of uniform geomagnetic lines to pass through without obstruction, while the three-layer Pomeranian spiral intercepts most of the miscellaneous magnetic lines. The two work together to achieve selective magnetic control of "miscellaneous magnetic interception and geomagnetic passage", with geomagnetic drift ≤0.01°, which is impossible to achieve with a fully enclosed shielding structure.

[0048] (iv) Replaceable non-magnetic interlayer and multi-scenario adaptation: The three interlayers of 0.05 / 0.1 / 0.2mm can be replaced on site, so that the same device can be adapted to three scenarios: low-magnetic office, standard workshop and strong-magnetic, without replacing the whole machine. This is something that fixed parameter shielding cabinets cannot achieve.

[0049] (v) Synergy between fully passive architecture and high security level compliance: The whole machine has no MCU / DSP / FPGA, no firmware tampering and data leakage vulnerabilities, and can pass compliance review in classified scenarios such as ships and high security level computer rooms, which is something that active intelligent devices cannot achieve.

[0050] In conclusion, the technical solution of this application has outstanding substantive features and significant progress compared with the prior art, and meets the requirements of Article 22, Paragraph 3 of the Patent Law regarding inventiveness. Attached Figure Description

[0051] Appendix Figure 1 (Abstract with attached diagram): Longitudinal assembly sectional view of the entire machine, showing a complete seven-layer structure, labeled with all numbers from 01 to 08; (Attached) Figure 2 Industrial vertical radial layered sectional view, vertically showing the complete hierarchy of the base, three-layer magnetic circuit, and central channel; (with appendix) Figure 3 Top view of a single-layer NS co-directional spiral unit, showing only the single winding structure number 03; (Attached) Figure 4 Desktop side view diagram, simplifying the overall side view hierarchy; (Attached) Figure 5 : Schematic diagram of the layered cross-section of the industrial model, showing the distinction between the magnetic circuit and the interlayer filling area; (Attached) Figure 6 Cross-sectional structural diagram of a high-security heavy-duty cabinet, showing the thickened shell and thickened inner magnetic substrate; (Attached) Figure 7 : Schematic diagram of the embedded tooling in the arc-shaped segment, showing only a partial spiral unit 03, without a base or complete three-layer layout; Attached Figure 8 Schematic diagram of the three-layer magnetic circuit frequency band classification principle; Attached Figure 9 : Schematic diagram of geomagnetic passage through a geomagnetic channel; Attached Figure 10 Overall block diagram of the complete magnetic circuit principle of the whole machine; Reference Table of Figure Labels Support base components: (01) - Non-magnetic anti-slip support base Outer magnetic circuit components: (03) - Outer high-frequency NS co-directional double helix magnetic circuit; (04) - Outer non-magnetic silicone insulating interlayer Middle layer magnetic circuit components: (05) - Middle layer intermediate frequency NS co-directional double helix magnetic circuit; (06) - Middle pressure-resistant buffer interlayer Inner magnetic circuit components: (07) - Inner low-frequency slow-release NS co-directional double helix magnetic matrix Geomagnetic channel components: (08) - Central through-type geomagnetic hollow channel Housing components: (02) - Sealed protective housing Detailed Implementation

[0052] 4.1 General Description The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The entire machine undergoes four pretreatment processes for magnetic raw materials: Process 0: 1J85 permalloy strip is dried at 100℃ for 4 hours under constant temperature control (±3℃) to remove internal moisture and prevent delamination and cracking defects during winding; Process 1: Non-magnetic silicone interlayer is plasma-cleaned for 60 seconds to remove metal dust and impurities, preventing the creation of new localized distorted magnetic fields; Process 2: Polyimide (PI) buffer film is vacuum-placed for 20 minutes to fully degas, ensuring no interlayer slippage or misalignment during long-term vibration; Process 3: After the helical winding is wound and shaped at 80-90℃ without adhesive, it is vacuum-annealed with hydrogen to eliminate mechanical stress, stabilizing the initial permeability to 20,000-50,000 and the maximum permeability to 50,000-120,000. General-purpose models are compatible with alternating mixed magnetic fields of -40 to 70℃ and 0.08-8mT; high-safety-level models extend this to be compatible with strong mixed magnetic fields of 8-10mT. All embodiments use a unified simulation benchmark: an electromagnetic field finite element simulation model, cross-validated with three sets of different mesh densities and boundary conditions. The entire system operates entirely without any programmable logic chips such as MCUs, DSPs, or FPGAs, relying entirely on a passive magnetic circuit structure. In all embodiments, the numbers marked in parentheses correspond to the attached figure reference table, allowing those skilled in the art to completely reproduce the system.

[0053] 4.2 Example 1: Standard Desktop Version for Government and Enterprise Offices This embodiment is a standard form of the whole machine, designed for government office and chip research desktop scenarios, absorbing high-frequency alternating stray magnetism from routers, desktop computers, and monitors.

[0054] (a) The whole machine has a seven-layer structure The entire machine is assembled in seven layers from the outside in: First layer (non-magnetic support base layer, 01): Non-magnetic PP anti-slip base, can be placed flat on any tabletop; Second layer (outer high-frequency magnetic circuit + outer layer, 03+04): outer high-frequency NS co-directional double helix magnetic circuit (03), 0.1mm standard non-magnetic silicone insulating interlayer (04); The third layer (middle-layer intermediate frequency magnetic circuit + middle layer, 05+06): middle-layer intermediate frequency NS co-directional double helix magnetic circuit (05), 0.1mm middle pressure-resistant buffer interlayer (06); Fourth layer (inner low-frequency magnetic matrix layer, 07): inner low-frequency slow-release NS co-directional double helix magnetic matrix (07); Fifth layer (penetrating geomagnetic channel layer, 08): Axially oriented centrally penetrating geomagnetic hollow channel (08), with a cross-sectional area of ​​45%; Sixth layer (sealed protective shell layer, 02): ABS sealed shell, with micro heat dissipation gaps reserved on the side wall; The seventh layer (matching auxiliary material layer): 0.05 / 0.1 / 0.2mm three-level replaceable non-magnetic silicone interlayer matching auxiliary material.

[0055] The overall dimensions are 30×30×40cm, and it is compatible with alternating magnetic fields in office environments of 0.08~0.2mT. The stable operating temperature range is −20℃~60℃ (the desktop version has a narrower temperature range, while the industrial / high-safety version is compatible with −40℃~70℃).

[0056] (II) Mass Production Assembly Process Process 1: Cut 1J85 permalloy strip, dry at 100℃ for 4 hours to remove moisture, and perform plasma cleaning for 60 seconds; Process 2: Perform plasma cleaning of the non-magnetic silicone interlayer for 60 seconds, and vacuum degassing of the PI buffer film for 20 minutes; Process 3: Wind the outer high-frequency spiral in the same direction at 80-90℃ without adhesive NS, stamping to a tolerance of ±0.01mm, and vacuum hydrogen annealing after winding; Process 4: Insert the outer 0.1mm non-magnetic silicone interlayer into the limiting slot; Process 5: Assemble the middle-layer medium-frequency spiral and the middle buffer interlayer in layers; 6: Inner layer low-frequency magnetic substrate integral molding assembly; 7: Central non-magnetic bracket positioning and connecting the geomagnetic channel to ensure no magnetic obstruction along the entire axial direction; 8: Seven-layer components are installed into an ABS sealed shell, with reserved side wall convection heat dissipation gaps; 9: Bottom integral injection molding non-magnetic anti-slip base; 10: 0.05 / 0.1 / 0.2mm multi-thickness sandwich layers are independently packaged as supporting auxiliary materials; 11: Factory use 50μT standard geomagnetic static 3-minute uniform zero-point calibration; Civilian model 1000V withstand voltage full test.

[0057] (III) Complete Demagnetization Process Deployment phase: Use a three-dimensional flux density meter to measure the alternating distortion of stray magnetism in the desktop space. If the stray magnetism intensity is ≤0.15mT, use a 0.05mm interlayer; if it is 0.15~0.4mT, use a 0.1mm interlayer in the standard environment. Place the non-magnetic base flat and rotate the whole machine so that the central geomagnetic channel is parallel to the north-south geomagnetic field. During the acquisition and diversion stage: most of the uniform magnetic field lines are intercepted by the three-layer Pomeranian spiral, and a small amount of magnetic flux passes through the central channel without obstruction; due to the difference in dynamic magnetic reluctance, the high-frequency and medium-frequency alternating distorted stray magnetism automatically stratifies and gathers to the corresponding NS-in-the-direction spiral circuit; the static residual magnetism of the metal is guided and converged by the inner magnetic matrix. Dissipation stage: The disordered alternating hybrid magnetism reciprocates and circulates within the spiral to magnetize the Permalloy domains, relying on the 1J85 alternating hysteresis loss to convert a small amount of heat energy, and the shell gaps naturally dissipate heat through convection; the magnetically saturated self-balancing structure automatically diverts excess magnetic flux to the middle and inner layers under strong hybrid magnetism; the static residual magnetism has no reciprocating magnetization and does not generate heat dissipation. Release phase: The uniform magnetic flux after stratified purification is released into the entire space, continuously reducing the overall alternating distortion and stray magnetic field level of the site; Operation and maintenance phase: Annual maintenance only involves wiping the dust off the interlayer surface, without disassembling the magnetic circuit components; every 3 years, the interlayer is disassembled to check its aging condition. If there is no pulverization or metal precipitation, it can continue to be used.

[0058] Desktop simulation conditions: In government office settings at 20-30℃, static stray magnetic field is 0.08-0.2mT, and the alternating stray magnetic field of the whole machine decreases by 76%-80% after 72 hours; the desktop geomagnetic compass drifts ≤0.01° when placed close to the desktop; three-year simulation of thermal cycling at -10 to 50℃, with no powdering or delamination of the interlayer; simulation of continuous full-load operation at 50℃ for 720 hours, with hysteresis loss fluctuation ≤4%; simulation of 10,000 desktop movement vibrations, with no misalignment or slippage of the three-layer spiral.

[0059] (iv) Troubleshooting Plan Fault 1: The effect of controlling alternating magnetic field in space has significantly decreased: Replace the interlayer with a 0.2mm thicker one to reduce interlayer magnetic flux coupling; Fault 2: Desktop compass drifts: Readjust the overall horizontal orientation of the machine so that the central geomagnetic channel is strictly parallel to the north-south geomagnetic field. Fault 3: Obvious residual magnetic particles in some areas: After confirming that there was no metal dust contamination in the interlayer, the interlayer was cleaned with plasma and then reassembled.

[0060] (v) Verification by comparison and simulation The two core structures, outer spiral (03) and outer interlayer (04), were removed. Under the same standard working conditions, the alternating magnetic field attenuation was only 27% after 72 hours, and the core function of high-frequency alternating magnetic field layering was lost, proving the necessity of the seven-layer structure synergy.

[0061] 4.3 Example 2: Precision CNC Industrial Vertical Standard Version This embodiment is designed for precision CNC machine tool workshops and is adapted to manage the alternating magnetic field interference of CNC machine tool servo motors. The overall shape is a 1.2×0.6×1.5m corrosion-resistant carbon steel shell, with a thickened medium-frequency spiral (05) in the middle layer, and a 0.1mm pressure-resistant interlayer. The geomagnetic channel accounts for 50% of the total area and can withstand 0.2~0.4mT alternating magnetic fields in the workshop.

[0062] (a) Key points of differentiated work process The industrial vertical model is fixed next to the CNC machine tool. The thickened medium-frequency spiral in the middle layer is specially designed to capture the 50-400Hz servo motor excitation alternating magnetic field. The 0.1mm pressure-resistant interlayer is adapted to the vibration environment of the workshop. The geomagnetic channel accounts for 50% to balance the passage of geomagnetic field and capture of stray magnetic field. When multiple units are connected in parallel, the geomagnetic channels of multiple units are aligned along the same north-south direction to synchronously balance the alternating stray magnetic field in a large area of ​​the workshop.

[0063] (ii) Differences in mass production processes The following additions were made to the standard process: the middle spiral is wound with 1J85 strip with a large cross-sectional area (double the wire diameter); the interlayer is made of 0.1mm pressure-resistant non-magnetic silicone (Shore hardness 60°); the shell is changed to corrosion-resistant carbon steel; a simulation inspection of continuous operation in a 50℃ workshop for 5 years was added; and a base leveling calibration process was added before leaving the factory.

[0064] (III) Key Points of Operation and Maintenance The simulation was continuously operated in a 50℃ workshop for 5 years without interruption. The alternating magnetic field attenuation was stable at 76% to 81%, and the shell was free of rust. It solved the problems of alternating magnetization and dimensional dispersion of the processing measuring tools. The aging interlayer was replaced on-site every year without the need to return the whole machine to the factory. The orientation of the geomagnetic channel was uniformly calibrated when multiple units were connected in parallel.

[0065] 4.4 Example 3: High-security-level heavy-duty cabinet-type ship This embodiment is designed for the scenario of alternating stray magnetic equilibrium in the entire command cabin of a ship, without interfering with the shipborne geomagnetic navigation compass. The overall shape is a 2×1×1.8m thickened anti-corrosion shell, with a thickened low-frequency magnetic substrate (07) inside, and a 0.2mm anti-stray magnetic interlayer (nominal adaptation limit of 8mT, with sufficient margin for 1mT working condition in ship cabins). It has passed 500h neutral salt spray simulation and is adapted to 1mT alternating stray magnetic conditions in ship cabins.

[0066] (a) Key points of differentiated work process The heavy-duty cabinet-style design is fixed to the ship's command compartment. The inner layer is thickened with a low-frequency magnetic matrix to guide and concentrate the long-term static residual magnetism of the ship's metal. The 0.2mm thickened interlayer is adapted to the 8mT extreme alternating stray magnetism. The perfluororubber seal is adapted to the salt spray environment. The geomagnetic channel retains some geomagnetic lines of force, which does not interfere with the ship's compass. When multiple compartments are linked, the extended geomagnetic channel version is suitable for continuous magnetic environment management in long and narrow ship corridors.

[0067] (ii) Differences in mass production processes Additions: The inner magnetic substrate is thickened to twice that of the standard model; the shell is made of thickened anti-corrosion carbon steel with 500h neutral salt spray anti-corrosion coating; perfluororubber sealing rings; micro-ventilation channels for sealed compartments are added; 1500V withstand voltage full test is added at the factory; 500h salt spray simulation sampling test is added.

[0068] (III) Key Points of Operation and Maintenance It can withstand 1mT of alternating stray magnetic field in ship compartments without core saturation; it shows no rust or delamination after 500h of neutral salt spray simulation; it does not interfere with shipborne geomagnetic navigation compasses; it requires annual on-site replacement of aged interlayers and sealing rings; and it remains undamaged during long-term storage in high-humidity marine environments.

[0069] 4.5 Example 4 Laboratory Weak Magnetic Calibration Fixture This embodiment is designed for the geomagnetic reference calibration of magnetic materials in universities. The outer shell (02) is removed, and the three-layer spiral (03)(05)(07) and the through geomagnetic channel (08) are completely retained; there is no shielding structure, and the interlayer with different thicknesses can be freely replaced, and the shell does not interfere with the geomagnetic field.

[0070] (a) Key points of differentiated work process The laboratory calibration model removes the sealed outer shell to reduce the disturbance of the geomagnetic field to the metal shell; the three-layer spiral is placed in the open, and the geomagnetic channel is completely unobstructed; the 0.05 / 0.1 / 0.2mm interlayer can be freely replaced to test the isolation effect between different layers; the quantum laboratory ultra-low alternating impurity magnetic improved model widens the geomagnetic channel to 60%, further improving the geomagnetic flux.

[0071] (ii) Differences in mass production processes The sealing shell assembly process (process 8) has been eliminated; passivation treatment of exposed magnetic edge has been added; geomagnetic channel uniformity calibration has been added at the factory; and the geomagnetic channel ratio of the improved quantum version has been adjusted to 60%.

[0072] (III) Key Points of Operation and Maintenance Suitable for geomagnetic reference calibration of magnetic materials in universities; no shell interference, high geomagnetic reference accuracy; channel ratio of 60% in ultra-low alternating magnetic environment of quantum laboratory; regular cleaning of dust on exposed spiral surface.

[0073] 4.6 Example 5: 32-axis height-enhanced vertical machine tool fixture This embodiment is designed for vertical long-shaft motors operating in scenarios with alternating mixed magnetic fields. The entire machine is vertically elongated, and the middle layer is synchronously heightened with a medium-frequency spiral to accommodate the vertical long-shaft motor's alternating mixed magnetic fields, solving the problems of alternating magnetization and dimensional discrepancies in machining gauges. It is equipped with a 0.1mm anti-compression interlayer, making it suitable for long-term operation in continuous cutting workshops.

[0074] (a) Key points of differentiated work process The heightened vertical version is placed next to the vertical machine tool. The middle layer of medium-frequency spiral synchronous heightened cover the vertical magnetic flux distribution of the long shaft motor; the 0.1mm anti-compression interlayer adapts to continuous cutting vibration; the geomagnetic channel is vertically connected and does not interfere with the geomagnetic reference of the workshop.

[0075] (ii) Differences in mass production processes The process of vertically raising the middle spiral winding (1.5 times the height of the standard model) has been added; the base has been widened to enhance stability; and vertical magnetic circuit uniformity calibration has been added.

[0076] (III) Key Points of Operation and Maintenance Solve the problems of magnetization and dimensional dispersion of machining gauges caused by vertical alternating stray magnetism of vertical long-shaft motors; ensure long-term stable operation in continuous cutting workshops; replace aged interlayers annually.

[0077] 4.7 Example 6: Hospital MRI Supporting Fixture This embodiment is designed for hospital MRI equipment rooms. It features an ultra-thin 0.05mm interlayer, widening the geomagnetic channel to 60%, preserving sufficient geomagnetic flux, and eliminating strong alternating magnetic flux interference with the MRI geomagnetic reference. The equipment can be placed close to the MRI equipment without imaging offset; the temperature range is suitable for a constant temperature environment of 10-40℃.

[0078] (a) Key points of differentiated work process The NMR-compatible model is placed in the area adjacent to the NMR equipment room. The 0.05mm ultra-thin interlayer reduces the disturbance of the magnetic circuit to the geomagnetic field; the geomagnetic channel accounts for 60% to maximize the retention of geomagnetic flux; the temperature rise of the whole machine is ≤3℃, which does not interfere with the temperature control benchmark of the NMR equipment; and it can operate stably in a constant temperature environment of 10~40℃.

[0079] (ii) Differences in mass production processes The interlayer is fixed with an ultra-thin 0.05mm thickness; the geomagnetic channel ratio is adjusted to 60%; the shell is made of low-permeability ABS material; and nuclear magnetic environment simulation verification is added at the factory.

[0080] (III) Key Points of Operation and Maintenance The computer room is placed adjacent to the NMR equipment without imaging offset; sufficient geomagnetic flux is retained to avoid interfering with the NMR reference; the constant temperature computer room environment is stable over a long period of time; the interlayer surface is cleaned annually.

[0081] 4.8 Example 7: Vehicle-Mounted Mini Tooling for Field Operations This embodiment is designed for electronic alternating magnetic field equalization scenarios inside field command vehicles. The overall dimensions are 40×25×30cm, with an IP54 dustproof shell and a weight of 3.2kg. It features a vehicle-mounted buckle fixing structure and can withstand vehicle temperature fluctuations ranging from −40 to 60℃.

[0082] (a) Key points of differentiated work process The vehicle-mounted mini version is fixed inside the command vehicle via vehicle clips. It is IP54 dustproof to adapt to dusty vehicle environments; has a wide temperature range of -40 to 60℃ to adapt to temperature fluctuations in the vehicle; a three-layer spiral to capture alternating stray magnetic fields from electronic devices inside the vehicle; and retains a portion of the geomagnetic field in the geomagnetic channel to avoid interfering with the vehicle navigation.

[0083] (ii) Differences in mass production processes Added IP54 dustproof sealing process; added vehicle-mounted buckle fixing structure; miniaturized overall design (weight 3.2kg); added simulated sampling inspection of temperature cycle from -40 to 60℃.

[0084] (III) Key Points of Operation and Maintenance The field command vehicle features electronic alternating magnetic equilibrium; it is resistant to vehicle temperature fluctuations and dust; the vehicle-mounted clips allow for quick installation and removal; and the dust filter requires annual cleaning.

[0085] 4.9 Example 8: Medium-sized tooling for high-voltage power distribution room This embodiment is designed for alternating magnetic field scenarios in high-voltage power distribution rooms. It features a widened middle spiral structure with a 0.2mm thickened interlayer, capable of withstanding 0.4–0.6 mT alternating magnetic field from transformers, protecting the geomagnetic metering instrument from drift. It also includes an oil-resistant shell coating, suitable for dusty and oily environments in power distribution rooms.

[0086] (a) Key points of differentiated work process The distribution room version is placed next to the transformer, with a widened middle spiral layer to capture the alternating magnetic field of the 50Hz power frequency transformer; a 0.2mm thickened interlayer isolates strong power frequency impurities; an anti-oil coating adapts to the dusty and oily environment of the distribution room; and a geomagnetic channel preserves geomagnetic protection for metering instruments.

[0087] (ii) Differences in mass production processes The middle layer features a widened spiral design; the interlayer is fixed with a 0.2mm thicker material; the shell has an added oil-resistant coating; and a 0.6mT power frequency magnetic field simulation verification is added at the factory.

[0088] (III) Key Points of Operation and Maintenance It can withstand alternating magnetic fields from transformers with a voltage rating of 0.4–0.6 mT; it protects geomagnetic meters from drift; the oil-resistant coating adapts to harsh environments; and the oil-resistant aging interlayer needs to be replaced annually.

[0089] 4.10 Example 9: High-Safety-Level Field Substation This embodiment is designed for outdoor substations operating in all seasons. It expands the stable operating temperature range to -40℃ to 70℃, features a double-layer composite 0.2mm interlayer, withstands 1mT of outdoor high-voltage alternating magnetic interference, ensures stable operation in outdoor equipment rooms throughout the year, and has a thickened rainproof and dustproof coating on the casing.

[0090] (a) Key points of differentiated work process This outdoor substation is designed for open-air placement and can adapt to temperature variations throughout the year, ranging from -40 to 70℃. It features a double-layer composite 0.2mm interlayer for enhanced interlayer isolation, automatic current shunting under 1mT high-voltage alternating magnetic field with magnetic saturation self-balancing, and a thickened rainproof and dustproof coating to suit outdoor environments.

[0091] (ii) Differences in mass production processes Add a double-layer composite sandwich assembly process; thicken the rainproof and dustproof coating on the shell; widen the working temperature range to -40 to 70℃; and add outdoor rain simulation sampling inspection.

[0092] (III) Key Points of Operation and Maintenance Stable operation in open-air computer room throughout the four seasons; withstands 1mT high-voltage alternating magnetic field in the field; rainproof and dustproof coating protects the whole machine; annual inspection of coating aging status.

[0093] 4.11 Example 10: 8mT Radar Special High-Security Version This embodiment is designed for high-intensity distorted alternating magnetic field scenarios in radar compartments. It features an additional double-layer permalloy shielding layer on the outer surface and three layers of thickened annealed permalloy spirals, capable of withstanding an 8mT extreme alternating stray magnetic environment without core saturation, thus adapting to the management of high-intensity distorted alternating magnetic fields in radar compartments; a 1500V withstand voltage test is added to all samples before shipment.

[0094] (a) Key points of differentiated work process The special radar model is placed inside the radar compartment. The outer layer is equipped with a double-layer permalloy shielding auxiliary layer to pre-filter 8mT of extreme stray magnetic fields. The three-layer thickened annealed permalloy spiral works in concert to dissipate current under the magnetic saturation self-balancing mechanism. There is no magnetic core saturation failure. The geomagnetic channel retains part of the geomagnetic field so as not to interfere with radar navigation.

[0095] (ii) Differences in mass production processes Add an outer double-layer permalloy shielding auxiliary layer assembly; thicken all three-layer spiral design; add 1500V withstand voltage full test at the factory; add 8mT extreme impurity magnetic simulation verification.

[0096] (III) Key Points of Operation and Maintenance It can withstand an extreme alternating magnetic environment of 8mT without core saturation; it is suitable for the management of high-intensity distorted alternating magnetic fields in radar compartments; the magnetic saturation self-balancing mechanism ensures wide dynamic stability; and the aging status of the shielding auxiliary layer is checked annually.

[0097] 4.12 Example 11: Arc-shaped segmented embedded derivative tooling (derived application form) The arc-shaped segmented unit is obtained by cutting three layers of continuous spiral units along the winding direction, retaining the NS co-directional double spiral magnetic circuit structure and hysteresis loss demagnetization mechanism. Adhesive backing is used to bond to the shells of ships and tanks for local alternating residual magnetism balancing. The magnetic flux capture area of ​​the segmented unit is less than 40% of the entire unit, and the local alternating stray magnetism decays by 40%–48% after 72 hours, making it suitable for local alternating residual magnetism balancing scenarios on equipment shells. With the addition of a complete vertical base, a three-layer longitudinal layout, and a long, continuous geomagnetic channel, it can be expanded into a complete all-domain space management unit.

[0098] 4.13 Comparative Example 12: Module Missing Comparison Simulation Prototype Model This embodiment is used to verify the synergistic effect of seven types of modules. All materials, dimensions, and process parameters of the simulation prototype model are the same as in Embodiment 1, except for individual removal or replacement of a single core module: Control Simulation Group A: Removal of the outer high-frequency spiral resulted in a 27% decrease in impurity magnetic field after 72 hours; Control Simulation Group B: Removal of the middle-layer medium-frequency spiral resulted in a 35% decrease in impurity magnetic field after 72 hours; Control Simulation Group C: Removal of the inner low-frequency magnetic matrix resulted in a 42% decrease in impurity magnetic field after 72 hours; Control Simulation Group D: The geomagnetic channel was removed and replaced with a fully enclosed structure, resulting in complete compass failure; Control Simulation Group E: The non-magnetic interlayer was removed and replaced with direct contact, resulting in a 48% decrease in impurity magnetic field after 72 hours. The performance of the five simulation prototype models deteriorated significantly, proving that the combination of a three-layer graded spiral + a through-type geomagnetic channel + a non-magnetic interlayer + magnetic saturation self-balancing exhibits a synergistic technical effect, and that no single core module can be omitted.

[0099] 4.14 Standardized Complete Operation Procedures for the Entire Machine (S1~S10) S1. Use a three-dimensional flux density meter to measure the alternating distortion of the magnetic field strength in the site space, and install 0.05 / 0.1 / 0.2mm thick non-magnetic interlayers (04)(06) into the interlayer slots; if the alternating distortion of the magnetic field treatment effect deteriorates, replace the 0.2mm thick interlayer first. S2. Place the non-magnetic base (01) flat and rotate the whole machine to make the center of the geomagnetic channel (08) parallel to the north and south geomagnetic fields; if the compass drifts, readjust the orientation of the whole machine. S3. Most of the uniform magnetic field lines are intercepted by the three-layer Pomeranian spiral (03)(05)(07), and a small amount of magnetic flux passes through the central channel (08) without obstruction and is not completely intercepted by the three-layer spiral. S4, high frequency and medium frequency alternating distortion stray magnetism are layered and gathered into the corresponding NS unidirectional spiral circuit due to dynamic magnetic reluctance differences. The static residual magnetism of the metal is guided and gathered by the inner magnetic matrix, and the magnetic flux is automatically shunted under strong magnetic conditions by relying on magnetic saturation nonlinearity. S5. The disordered alternating magnetic flux reciprocates and circulates within the spiral to magnetize the Permalonic domains. It relies on the 1J85 alternating hysteresis loss to convert a small amount of heat energy into heat, and the shell gaps are naturally convected to dissipate heat. The static remanent magnetization has no reciprocating magnetization process and does not generate heat dissipation. S6. The uniform magnetic flux after layered purification is released into the entire space, continuously reducing the overall alternating distortion and stray magnetic level of the site. S7. Annual maintenance: Wipe the surface of the interlayer with a clean, soft cloth to remove metal dust; no need to disassemble the magnetic circuit components. Check the aging condition of the interlayer every 3 years. S8, Embedded Modification Scene: Cut arc-shaped segmented spiral units, and apply adhesive backing to armor and ship hull for localized balanced alternating residual magnetism; S9, Laboratory calibration scenario: Remove the sealed shell (02) and retain the three-layer spiral and geomagnetic channel as geomagnetic reference tooling; S10, 8mT extreme alternating mixed magnetic field scenario: replace with double-layer composite 0.2mm interlayer to improve interlayer magnetic flux isolation capability.

[0100] 4.15 Standardized mass production complete assembly process The four pre-treatment processes are the same as described above; Process 1: Outer high frequency spiral (03) is wound at 80~90℃ without glue, with strict NS direction, stamping forming tolerance ±0.01mm, and vacuum hydrogen annealing after winding is completed; Step 2: Insert the outer non-magnetic silicone interlayer (04) into the limiting slot; Process 3: Layered assembly of the middle-layer intermediate frequency spiral (05) and the middle buffer interlayer (06); Process 4: Inner layer low-frequency magnetic substrate (07) integral molding and assembly; Step 5: Position the central non-magnetic support to connect the geomagnetic channel (08) to ensure that there is no magnetic obstruction along the entire axial direction; Step 6: The seven-layer assembly is installed into the sealed housing (02), with a reserved side wall convection heat dissipation gap; Process 7: One-piece injection molding of non-magnetic anti-slip base (01); Step 8: 0.05 / 0.1 / 0.2mm multi-thickness sandwich panels are individually packaged as supporting auxiliary materials; Step 9: The factory uses a 50μT standard geomagnetic field to stand still for 3 minutes for unified zero-point calibration; Process 10: All civilian models with 1000V withstand voltage are tested, and all high-safety-level models with 1500V withstand voltage are tested. Process 11: For high-safety-level products, an additional 500-hour neutral salt spray anti-corrosion spraying process is added.

[0101] Factory qualification criteria: geomagnetic drift ≤0.01°, alternating magnetic decay ≥75% after 72 hours, no dust precipitation in the interlayer, and initial permeability stable in the range of 20,000 to 50,000 after annealing, and maximum permeability stable in the range of 50,000 to 120,000.

Claims

1. A passive, full-range vertical magnetization and demagnetization device with NS co-directional double helix, comprising a non-magnetic support base, a sealed protective shell, and a layered magnetic circuit structure, characterized in that, The shell is arranged in layers from the outside to the inside, including an outer high-frequency NS co-directional double helical magnetic circuit (03), an outer non-magnetic silicone insulating interlayer (04), a middle medium-frequency NS co-directional double helical magnetic circuit (05), a middle pressure-resistant buffer interlayer (06), and an inner low-frequency slow-release NS co-directional double helical magnetic matrix (07). A geomagnetic hollow channel (08) is set through the axial center of the whole machine, and the cross-sectional area of ​​the channel accounts for 40% to 60% of the axial cross-section of the whole machine. The outer, middle, and inner magnetic circuits all adopt NS co-directional continuous helical windings, and the winding material is 1J85 permalloy alloy that has been treated with vacuum hydrogen stress relief annealing. The interlayer is made of non-magnetic silicone material without iron, cobalt, and nickel magnetic particles, and the interlayer thickness is 0.05 to 0.2 mm. The whole machine has no external power supply terminals and no MCU / DSP / FPGA programmable electronic control components.

2. The apparatus according to claim 1, characterized in that, The outer spiral (03) is a fine winding structure adapted to the high-frequency pulse alternating stray magnetism of the 0.1-1MHz circuit board; the middle spiral (05) is a coarse cross-sectional area winding adapted to the 50-400Hz alternating excitation magnetic field of the motor; the inner magnetic matrix (07) is a thickened structure used to guide and converge the static low-frequency residual magnetism of the metal shell; the number of turns and cross-sectional area ratio of the three spirals are fixed, and the three types of complete machines are derived by proportional scaling: 30×30cm desktop model, 1.2m industrial vertical model, and 2m high-safety-level heavy cabinet model.

3. The apparatus according to claim 1, characterized in that, The cross-sectional area of ​​the centrally connected geomagnetic hollow channel (08) accounts for 40% to 60% of the axial cross-section of the whole machine. There are no magnetic conductive components inside the channel. Most of the geomagnetic lines are intercepted by the three-layer Pomeranian spiral. A small number of uniform geomagnetic lines are completely unobstructed and run through the whole machine. The geomagnetic drift is ≤0.01°. When the channel accounts for less than 40%, the geomagnetic flux is insufficient. When the channel accounts for more than 60%, the effective area for capturing alternating stray magnetic fields is reduced.

4. The apparatus according to claim 1, characterized in that, The non-magnetic silicone interlayer (04)(06) has three interchangeable thicknesses: 0.05mm, 0.1mm, and 0.2mm. 0.05mm is suitable for low alternating magnetic interference scenarios in offices, 0.1mm is suitable for standard workshop scenarios, and 0.2mm is suitable for extreme alternating magnetic interference scenarios of ships with 8mT. The interlayer does not contain iron, cobalt, or nickel magnetic conductive metal particles, and physically isolates the mutual interference of alternating magnetic flux between layers.

5. The apparatus according to claim 1, characterized in that, The three-layer spiral is wound in the same direction without glue at 80-90℃. After winding, it is annealed in vacuum with hydrogen to eliminate mechanical stress, stabilizing the initial permeability of 20,000-50,000 and the maximum permeability of 50,000-120,000. The hysteresis loss power per unit volume under alternating operating conditions is about 0.05-0.2W / dm³ (equivalent to a surface power density of about 0.02-0.15W / m²), and the temperature rise of the whole machine is ≤3℃. Uniform convection heat dissipation gaps are reserved on the side wall of the shell, and micro-ventilation channels are added to the sealed compartment version.

6. The apparatus according to claim 1, characterized in that, The sealed protective housing (02) is divided into ABS desktop type, anti-corrosion carbon steel industrial type, and thickened salt spray high safety level type; the high safety level type adds a 500h neutral salt spray anti-corrosion spraying process and adds 1500V withstand voltage full test before leaving the factory; the base (01) and housing (02) are made of non-magnetic PP / anti-corrosion carbon steel material, which does not add local distorted magnetic field and does not change the original geomagnetic vector distribution of the site.

7. The apparatus according to claim 1, characterized in that, The three-layer continuous spiral unit can be cut into arc-shaped segmented units along the winding direction. The segmented units retain the NS co-directional double spiral magnetic circuit structure and hysteresis loss demagnetization mechanism. The backing adhesive is bonded to the equipment housing for local alternating residual magnetism balancing. The magnetic flux capture area of ​​the segmented unit is less than 40% of the whole machine, and the local alternating stray magnetism decays by 40% to 48% after 72 hours.

8. The apparatus according to claim 1, characterized in that, The three-layer magnetic circuit simultaneously constitutes a passive magnetic flux self-balancing structure. When the external alternating stray magnetism increases to the magnetic saturation region of the outer high-permeability Pomeranian spiral, the permeability of the outer layer decreases and the magnetic resistance increases. The magnetic flux is automatically transferred and distributed to the middle and inner spirals, and the middle and inner layers continue to dissipate excess magnetic energy through alternating hysteresis loss. When the external stray magnetism weakens, the permeability of the outer layer automatically recovers. The entire process requires no power supply and no chip control.

9. The apparatus according to claim 1, characterized in that, The machine has a stable operating temperature range of -40℃ to 70℃. The high-safety-level extended version is compatible with -40℃ to 70℃ and strong magnetic fields of 8 to 10mT. The machine is calibrated at the factory by standing in a 50μT standard geomagnetic field for 3 minutes. All civilian models are tested for 1000V withstand voltage, and all high-safety-level models are tested for 1500V withstand voltage.

10. A passive method for controlling spatial alternating stray magnetism based on the device of claim 1, characterized in that, The process includes the following steps: S1. Using a three-dimensional flux meter, the alternating distortion of the mixed magnetic field intensity in the site is measured, and a 0.05 / 0.1 / 0.2mm thick non-magnetic interlayer is installed in the interlayer slot; S2. The non-magnetic base is placed flat, and the entire machine is rotated to make the central through-magnetic channel parallel to the north-south geomagnetic field; S3. Most of the uniform geomagnetic lines are intercepted by the three-layer Pomeranian spiral, and a small amount of geomagnetic flux passes through the central channel without obstruction; S4. Due to the difference in dynamic magnetic resistance, the high-frequency and mid-frequency alternating distortion of the mixed magnetic field is layered and gathered into the corresponding NS-direction spiral loop. The static remanent magnetization of the metal is guided and gathered by the inner magnetic matrix, and the magnetic flux is automatically diverted under strong magnetic conditions by relying on magnetic saturation nonlinearity; S5. The disordered alternating magnetic flux cyclically magnetizes the Pomeranian domains inside the spiral, and a small amount of heat energy is converted by the alternating hysteresis loss of 1J85. The shell gaps are naturally cooled by convection, and the static remanent magnetization does not generate heat dissipation; S6. After being purified in layers, the uniform magnetic flux is released into the entire space, continuously reducing the overall level of alternating distortion and stray magnetic fields in the site.

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