Device for measuring contact resistance of spherical furnace charge

Abstract

The utility model relates to a device for measuring the contact resistance of a spherical furnace charge, which is suitable for testing the resistance of a low-resistance furnace charge in a metallurgical production process. The device comprises an insulating cylinder, a first adjusting plate and a second adjusting plate which are in sliding fit with the two ends of the insulating cylinder respectively. Four contact pins are arranged on the two adjusting plates, the first contact pin and the third contact pin are used for being connected with a voltmeter, the second contact pin and the fourth contact pin are used for being connected with an ampere meter, and a four-wire method testing loop is formed. The spherical furnace charge is placed between the two adjusting plates, and the contact pin is in stable contact with the surface of the furnace charge through sliding of the adjusting plates, so that the contact resistance of the spherical furnace charge is accurately measured. The device can reduce the influence of the lead resistance on the measurement precision, is suitable for measuring the contact resistance of spherical furnace charges with different particle sizes or different components, and is beneficial to improving the temperature uniformity and the energy utilization efficiency in the smelting process. The device is simple in structure, convenient to operate, high in adaptability and high in application value.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical production technology and relates to a device for measuring the contact resistance of spherical furnace charge. Background Technology

[0002] Electric arc furnace (EAF) smelting is a method of melting furnace charge by heating it with the thermal effect of an electric arc. Alternating current is input into the furnace through graphite electrodes, generating an electric arc between the lower end of the electrodes and the metal charge. The high temperature of the arc directly heats the charge, allowing the smelting process to proceed. The raw materials for EAF smelting mainly include scrap steel and direct reduced iron (DRI), with scrap steel typically accounting for over 50% and DRI generally comprising 30-50%. Resistance is a physical quantity that measures the electrical conductivity of a material. In EAF smelting, significant differences in the resistance of the furnace charge not only affect the uniformity of the furnace temperature but also lead to reduced product quality and production efficiency. Besides the resistance of the charge itself, changes in resistance caused by contact between charges also directly affect the efficiency of converting electrical energy into heat energy, which is crucial for EAF smelting.

[0003] Taking direct reduced iron (DRI) as an example, DRI has a high Fe content and low resistivity. To reduce errors caused by wire resistance during measurement, the four-wire method (four-terminal method) is suitable for measuring its resistance. The four-wire method is mainly used for accurate measurement of low-value resistors. Its principle is that a constant current power supply provides current to the low-value resistor under test, and the voltage is measured through two voltage leads to determine the potential difference formed on the low-value resistor under test by the current supplied by the constant current power supply. The resistance value is obtained from the ratio of voltage to current.

[0004] Existing four-wire method testing devices typically use clamps to fix the sample. However, it is difficult to directly measure the resistance when spherical furnace charge phases such as reduced iron come into contact with the sample using existing four-wire method testing devices. Therefore, a new testing device needs to be designed. Utility Model Content

[0005] In view of this, the purpose of this utility model is to solve the problem of measuring the contact resistance of spherical furnace charge, and to propose a device for measuring the contact resistance of spherical furnace charge.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An apparatus for measuring the contact resistance of spherical furnace charge includes an insulating cylinder with a charge placement cavity for holding the charge whose resistance is to be measured. A first adjusting plate and a second adjusting plate are respectively arranged opposite to each other at both ends of the charge placement cavity, and both the first and second adjusting plates are slidably engaged with the insulating cylinder. A first contact pin and a second contact pin are provided on the first adjusting plate; a third contact pin and a fourth contact pin are provided on the second adjusting plate.

[0008] The first and third contact pins are connected to a voltmeter via wires to form a voltage circuit; the second and fourth contact pins are connected to an ammeter via wires to form a current return; the furnace charge is placed between the first and second adjusting plates, and by moving the first and second adjusting plates, the first, second, third, and fourth contact pins simultaneously contact the surface of the furnace charge, thereby forming a four-wire method for measuring the contact resistance of the furnace charge.

[0009] Furthermore, both the first and second adjustment plates are provided with a fixing plate that protrudes into the furnace charge placement chamber, and the first, second, third, and fourth contact pins are respectively fixed on the fixing plate.

[0010] Furthermore, the insulating cylinder, the first adjusting plate, the second adjusting plate, and the fixing plate are all insulators.

[0011] Furthermore, the insulating cylinder is cylindrical, and both the first adjusting plate and the second adjusting plate are circular plates.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. This utility model adopts the "four-wire method (four-terminal method)" for resistance measurement, which effectively eliminates the influence of wire resistance and contact resistance on the measurement results and improves the accuracy of low resistance measurement. By arranging four contact pins on the first and second adjustment plates, which are independently connected to the voltmeter and ammeter respectively, the separation of constant current input and voltage measurement is ensured, avoiding the error superposition problem of the traditional two-wire measurement method.

[0014] 2. This device is suitable for measuring the contact resistance between spherical furnace charges of different particle sizes or compositions, covering a variety of metallurgical raw materials, such as scrap steel and direct reduced iron, to meet the needs of different production scenarios. For furnace charges with low resistivity, such as direct reduced iron, the four-wire method is used for precise measurement, overcoming the shortcomings of traditional devices in terms of insufficient testing accuracy in low-resistance environments.

[0015] 3. In this utility model, the first and second adjusting plates can slide and adjust along the insulating cylinder, making it easy to find the two ends of the diameter of the contacting spherical furnace charge. When repeating the test, the error can be reduced. By adjusting the position of the first and second adjusting plates, the stylus can quickly contact the surface of the spherical furnace charge, simplifying the complicated test preparation process and improving the operating efficiency.

[0016] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 This is a schematic diagram of the overall device for measuring the contact resistance of spherical furnace charge in this utility model.

[0019] Figure 2 This is a schematic diagram of the insulating cylinder in this utility model.

[0020] Figure 3 This is a schematic diagram of the installation of the stylus in this utility model.

[0021] Reference numerals in the attached diagram: 1-Wire; 2-Wire; 3-Wire; 4-Wire; 5-Insulating cylinder; 6-First adjusting plate; 7-Second adjusting plate; 8-Fixing plate; 9-Fixing plate. Detailed Implementation

[0022] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] Please see Figures 1-3 This is a device for measuring the contact resistance of spherical furnace charge, comprising an insulating cylinder 5, a charge placement cavity inside the insulating cylinder 5 for placing the charge whose resistance is to be measured; a first adjusting plate 6 and a second adjusting plate 7 are respectively installed at both ends of the charge placement cavity, and the first adjusting plate 6 and the second adjusting plate 7 are slidably engaged with the insulating cylinder 5; a first contact pin and a second contact pin are installed on the first adjusting plate 6; a third contact pin and a fourth contact pin are installed on the second adjusting plate 7.

[0026] The first contact pin is connected to the voltmeter via wire 4, and the third contact pin is connected to the voltmeter via wire 3, forming a voltage circuit. The second contact pin is connected to the ammeter via wire 1, and the fourth contact pin is connected to the ammeter via wire 2, forming a current return. The furnace charge is placed between the first adjusting plate 6 and the second adjusting plate 7. By moving the first adjusting plate 6 and the second adjusting plate 7, the first, second, third, and fourth contact pins simultaneously contact the surface of the furnace charge, thereby forming a four-wire method for measuring the contact resistance of the furnace charge.

[0027] In addition, a fixing plate 8 protruding into the furnace charge placement cavity is installed on the first adjusting plate 6, and a fixing plate 9 protruding into the furnace charge placement cavity is installed on the second adjusting plate 7. The first contact pin, the second contact pin, the third contact pin, and the fourth contact pin are respectively fixedly installed on the fixing plate 8 and the fixing plate 9.

[0028] In this embodiment, the insulating cylinder, the first adjusting plate, the second adjusting plate, and the fixing plate are all insulators. The insulating cylinder is cylindrical, and the first adjusting plate and the second adjusting plate are both circular plates.

[0029] The device for measuring the contact resistance of spherical furnace charge in this embodiment is used to measure the contact resistance of the spherical furnace charge, and includes the following steps:

[0030] (1) Place two spherical furnace charges in the furnace charge placement cavity of the insulating cylinder 5, so that the two spherical furnace charges are in contact;

[0031] (2) Adjust the positions of the first adjusting plate 6 and the second adjusting plate 7 so that the first and second contact pins are in contact with the horizontal diameter end on one side of the spherical furnace charge, and the third and fourth contact pins are in contact with the horizontal diameter ends on both sides of the spherical furnace charge.

[0032] (3) The first and third contact pins are connected to the voltmeter through wires, and the second and fourth contact pins are connected to the ammeter through wires. After the constant current power supply supplies current to the device, the values ​​of the ammeter and voltmeter are recorded as I and U, respectively.

[0033] (4) The resistance of the spherical furnace charge is obtained according to the formula R=U / I.

[0034] This device can be used to test the resistance of spherical furnace charge of different particle sizes when in contact. It can also be used to test the resistance of spherical furnace charge of the same particle size but different compositions when in contact.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A device for measuring the contact resistance of spherical furnace charge, characterized in that: The device includes an insulating cylinder with a charge placement cavity for holding the charge to be tested. A first adjusting plate and a second adjusting plate are respectively arranged opposite to each other at both ends of the charge placement cavity. Both the first and second adjusting plates are slidably engaged with the insulating cylinder. A first contact pin and a second contact pin are provided on the first adjusting plate. A third contact pin and a fourth contact pin are provided on the second adjusting plate. The first and third contact pins are connected to a voltmeter via wires to form a voltage circuit; the second and fourth contact pins are connected to an ammeter via wires to form a current return circuit. The furnace charge is placed between the first adjusting plate and the second adjusting plate. By moving the first adjusting plate and the second adjusting plate, the first contact pin, the second contact pin, the third contact pin and the fourth contact pin simultaneously come into contact with the surface of the furnace charge, thereby forming a four-wire method for measuring the contact resistance of the furnace charge.

2. The apparatus for measuring the contact resistance of spherical furnace charge according to claim 1, characterized in that: Both the first and second adjustment plates are provided with a fixing plate that protrudes into the furnace charge placement chamber, and the first, second, third, and fourth contact pins are respectively fixed on the fixing plate.

3. The apparatus for measuring the contact resistance of spherical furnace charge according to claim 2, characterized in that: The insulating cylinder, the first adjusting plate, the second adjusting plate, and the fixing plate are all insulators.

4. The apparatus for measuring the contact resistance of spherical furnace charge according to claim 1, characterized in that: The insulating cylinder is cylindrical, and both the first adjusting plate and the second adjusting plate are circular plates.

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