Frequency switching circuit for increasing molten iron stirring force
By designing a parallel capacitor and linkage switch for the induction coil, frequency regulation is achieved, magnetic field penetration is enhanced, the problem of insufficient stirring force of molten iron is solved, uniform distribution of alloying elements and temperature uniformity are achieved, and casting defects are reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2026-04-07
AI Technical Summary
During the operation of a series power supply, the high frequency causes the magnetic field to concentrate on the surface, resulting in weak penetration. This leads to insufficient stirring force in the molten iron, preventing the alloying elements from being evenly distributed. The internal heat transfer of the molten iron is hindered, causing an increase in the temperature difference between the center and the surface, resulting in casting porosity or cracks.
Design a frequency-switching circuit to increase the stirring force of molten iron. By connecting an induction coil in parallel with a capacitor and a normally open switch, the switching between two operating frequencies can be achieved. The frequency can be adjusted by the change in capacitance, thereby reducing the skin effect, enhancing the magnetic field penetration, and improving the stirring force.
It achieves uniform distribution of alloying elements in molten iron, reduces casting porosity and cracks, improves the uniformity of molten iron temperature, and ensures the effectiveness of the smelting process and casting quality.
Smart Images
Figure CN224097415U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of smelting furnaces, specifically to a frequency cutting circuit that increases the stirring force of molten iron. Background Technology
[0002] If the designed frequency cannot be adjusted during the operation of a series power supply, due to the skin effect of the current, the magnetic field will be concentrated on the surface at a high frequency, resulting in weak penetration. This leads to insufficient stirring force in the molten iron after melting. Insufficient stirring force causes alloying elements in the molten iron to be unable to be evenly distributed, hindering heat transfer inside the molten iron and increasing the temperature difference between the center and the surface, resulting in casting porosity or cracks.
[0003] To address the aforementioned problems, this invention designs and manufactures a frequency-cutting circuit that increases the stirring force of molten iron, thereby overcoming the aforementioned deficiencies. Summary of the Invention
[0004] To address the problems existing in the prior art, this utility model provides a frequency switching circuit that increases the stirring force of molten iron, enabling the switching between two operating frequencies and ensuring both power during smelting and stirring force during melting.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a frequency-cutting circuit for increasing the stirring force of molten iron, comprising an induction coil, wherein two sets of capacitors are connected in parallel at one end of the induction coil, wherein capacitor CⅠ and capacitor CⅡ are connected in series in one set of capacitors, and capacitor CⅢ and capacitor CⅣ are connected in series in the other set of capacitors;
[0006] It also includes a set of normally open switches KⅠ and KⅡ that are linked together. The normally open switch KⅠ is connected in parallel with capacitor CⅠ, and the normally open switch KⅡ is connected in parallel with capacitor CⅢ.
[0007] Preferably, the capacitors CⅠ, CⅡ, CⅢ, and CⅣ have the same capacitance.
[0008] Preferably, a current transformer is connected to the output terminals of the two sets of capacitors.
[0009] Preferably, the other end of the induction coil is connected to several sets of parallel thyristors.
[0010] Preferably, it also includes a power source, the positive and negative terminals of which are respectively connected to the other ends of the two sets of capacitors.
[0011] The advantages of this utility model are:
[0012] During normal smelting, this invention connects two resonant capacitors in each capacitor group in series to ensure normal smelting power. After the molten iron has melted, a set of linked normally open switches KⅠ and KⅡ short-circuit capacitor CⅠ and capacitor CⅢ respectively. At this time, the capacitance of each capacitor group increases by half. According to the formula for capacitive reactance and frequency, the frequency decreases by half. The reduced frequency weakens the skin effect, enhances the penetration of the magnetic field, increases the stirring force, and better ensures the uniformity of the molten iron temperature. This not only makes the alloying elements in the molten iron more uniform but also reduces casting porosity, cracks, and other casting defects. Attached Figure Description
[0013] Figure 1 A circuit diagram of a frequency-cutting circuit for increasing the stirring force of molten iron;
[0014] Figure 2 This is a partial circuit diagram of the present invention.
[0015] In the diagram: 1. Induction coil; 2. Capacitor CI; 3. Capacitor CI; 4. Capacitor CI; 5. Capacitor CI; 6. Normally open switch K1; 7. Normally open switch KII; 8. Current transformer; 9. Thyristor. Detailed Implementation
[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.
[0017] like Figure 1 , Figure 2 As shown, a frequency-cutting circuit for increasing the stirring force of molten iron includes an induction coil 1. Two sets of capacitors are connected in parallel at one end of the induction coil 1. One set of capacitors has capacitors CⅠ2 and CⅡ3 connected in series, and the other set of capacitors has capacitors CⅢ4 and CⅣ5 connected in series. The capacitances of capacitors CⅠ2, CⅡ3, CⅢ4, and CⅣ5 are the same.
[0018] It also includes a set of normally open switches KⅠ and KⅡ that are linked together. Normally open switch KⅠ6 is connected in parallel with capacitor CⅠ2, and normally open switch KⅡ7 is connected in parallel with capacitor CⅢ4.
[0019] During normal smelting, this invention connects two resonant capacitors in each capacitor group in series to ensure normal smelting power. After the molten iron has melted, a set of linked normally open switches KⅠ and KⅡ short-circuit capacitor CⅠ2 and capacitor CⅢ4 respectively. At this time, the capacitance of each capacitor group increases by half. According to the formula for capacitive reactance and frequency, the frequency decreases by half. The reduced frequency weakens the skin effect, enhances the penetration of the magnetic field, increases the stirring force, and better ensures the uniformity of the molten iron temperature. This not only makes the alloying elements in the molten iron more uniform but also reduces casting porosity, cracks, and other casting defects.
[0020] Current transformers 8 are connected to the output terminals of the two sets of capacitors to detect the current.
[0021] The other end of the induction coil 1 is connected to several sets of parallel thyristors 9. It also includes a power supply, the positive and negative terminals of which are respectively connected to the other ends of two sets of capacitors.
[0022] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Furthermore, it should be understood that after reading the technical description of this utility model, those skilled in the art can make various alterations, modifications, and / or variations to this utility model, and all such equivalent forms also fall within the scope of protection defined by the appended claims.
Claims
1. A frequency-cutting circuit for increasing the stirring force of molten iron, characterized in that, It includes an induction coil (1), one end of which is connected in parallel with two sets of capacitors. One set of capacitors has capacitor CⅠ (2) and capacitor CⅡ (3) connected in series, and the other set of capacitors has capacitor CⅢ (4) and capacitor CⅣ (5) connected in series. It also includes a set of normally open switches KⅠ and KⅡ that are linked together. The normally open switch KⅠ (6) is connected in parallel with capacitor CⅠ (2), and the normally open switch KⅡ (7) is connected in parallel with capacitor CⅢ (4).
2. The frequency-changing circuit for increasing the stirring force of molten iron according to claim 1, characterized in that, The capacitors CⅠ(2), CⅡ(3), CⅢ(4), and CⅣ(5) have the same capacitance.
3. The frequency-changing circuit for increasing the stirring force of molten iron according to claim 1, characterized in that, Current transformers (8) are connected to the output terminals of the two sets of capacitors.
4. The frequency-changing circuit for increasing the stirring force of molten iron according to claim 1, characterized in that, The other end of the induction coil (1) is connected to several sets of parallel thyristors (9).
5. The frequency switching circuit for increasing the stirring force of molten iron according to claim 1, characterized in that, It also includes a power supply, the positive and negative terminals of which are respectively connected to the other ends of the two sets of capacitors.