WO2022064280A1

WO2022064280A1 - An integrated hollow copper electrode in slag hole with thermal conductivity

Info

Publication number: WO2022064280A1
Application number: PCT/IB2021/050756
Authority: WO
Inventors: Majid RAHIMI
Original assignee: Danesh Parto Naghsh Jahan Co.
Priority date: 2020-09-26
Filing date: 2021-01-31
Publication date: 2022-03-31
Also published as: EP3994958A1; EP3994958A4

Abstract

In order to extend the service life of electrode in the slag hole, a single copper electrode has been used in this invention. The special design of this part in resistance to thermal stresses makes it safe as a protective part against temperature of 1200 C. The heat generated in the body of this part is expelled from the part through the circulating fluid through the designed ducts and the temperature of the part remains constant to the extent that it does not cause damage to the part. The heat generated in the body of this part is expelled from the part through the circulating fluid through the designed ducts and the temperature of the part remains constant to the extent that it does not cause the destruction of the part.

Description

Title of Invention : An Integrated hollow copper electrode in slag hole with thermal conductivity

Technical Field

[0001] The technical field of this invention relates to the equipment of steelmaking super-heavy electric arc is in which high purity copper electrode is used.

Background Art

[0002] The invention of the graphite electrode for electro-thermal furnaces (temperature reduction in electrically manner), the electrode column and the method of production of graphite electrodes has been registered in the Iranian Patent Office under registration number 33814, which reveals: A graphite electrode consisting of a graphite electrode body is made of anode type, which is graphitized at a temperature of less than 2700 C and has an iron content of less than 1 0.1 weight. Graphite electrode, which is an intermediate product, consists of anode-sized stitch particles with an average size of 5 to 10 mm and an ash content of less than 0.05% mixed with bitumen adhesive, which is in the form of a green electrode and must be cured to form a graphite electrode.

[0003] As it is clear from the text of the invention, the material of the electrode is graphite, while the material of the claimed electrode is copper, and on the other hand, in this invention, the method of producing graphite electrode is revealed, not the heat reduction method.

[0004] An invention called Blast furnace slag discharge trench with a built-in water cooling system has been published in China Patent Office No. 103468845, which is related to the slag electrode, whose main body is made of steel, which is different from the claimed invention. Also, as shown in the pictures of this invention, this piece is a semi-cylinder into which slag is poured, which differs from the appearance and function of the claimed invention. On the other hand, this device is not a single piece and consists of several separate pieces that are connected in parallel to each other and each has a separate cooling path. This method will have many problems in maintenance and operation. One of the problems is that if one part of this part does not work properly for any reason, it can damage other parts and the whole process.

[0005] Design, production, manufacture and operation of all types of copper parts undercooling (Kt Cooling Block, Contact Shoes, Cooling Element, Water Jacket, lounder, Kt Oxygen Lance, and double-walled form of the blast furnace) that despite the melting point of 1060 degrees, they bearing capacity of the temperature of 1850 ° C.

Technical Problem

[0006] A slag copper electrode is a special heat exchanger that has a key application in steel melting furnaces. This equipment is placed at the slag hole of furnaces of super heavy furnaces of 240 tons so that the slag exit from the kiln by side swiping with this part.

[0007] In steel production complexes, after several melting steps, slag hole slabs must be replaced, which will stop production for one hour. For example, in Mobarakeh Steel Complex, 38,000 molts are produced per year. After every 150 melts, the slag slab is replaced, causing 253 stops per year, resulting in a waste of 253 hours. 168 Melting can be performed at this lost time.

[0008] On the other hand, every slab replacement on the furnace stand can be very dangerous for the personnel, so if a solution is thought to solve this problem, it can have positive results in this industry.

[0009] If anyone has thought about using copper in the slag electrode, he/she have also faced the following problems:

[0010] 1 - High purity copper casting operation (99.99% cathode copper) with a weight of at least 5 tons without any porosity, air bubbles, and oxygen-free condition

[0011 ] 2- Taking appropriate heat treatment cycle to achieve recrystallization in order to ensure the homogeneity of the melt

[0012] 3- Taking appropriate heat treatment cycle to start hot forging operation

Solution to Problem [0013] In order to extend the life of the electrode in a slag hole, an integrated copper electrode has been used in this invention. In the design and construction of this equipment, high purity copper casting (cathode copper99/99) with a weight of 5 tons with a diameter of 670 mm and a length of 1600 mm is used, then heat treatment and recrystallization and then forging operation and reaching the desired dimensions are performed in the continuation of the stress relief operation and then rough machining operation is performed on the heavy lathe and then drilling operation in the longitudinal direction of the part (length of each duct is 2 meters and the total number of ducts 18) which is responsible for cooling and heat transfer operations. In the next step, creating water circulation as the best cooling by means of caps by an argon welding method and two iron- to-copper metals by Inconel welding wire and transfer pipes inside the part and after quality control test, the final machining operation is performed.

[0014] The special design of this part in resistance to thermal stresses makes it safe as a protective part against the heat of 1200 C. The heat generated in the body of this part is expelled from the part through the circulating fluid through the designed ducts and the temperature of the part remains constant to the extent that it does not cause damage to the part. The heat generated in the body of this part is expelled from the part through the circulating fluid through the designed ducts and the temperature of the part remains constant to the extent that it does not cause damage to the part.

Advantageous Effects of Invention

[0015] 1. Short melting time

[0016] 2. Non-adhesion of molten slag to this product due to the very low temperature of this product and the very high temperature of molten slag

[0017] 3. Easy passage of molten slag due to high -temperature difference

[0018] 4- Preventing the loss of electricity consumption of super heavy furnaces

[0019] 5. Long life of this product

Brief Description of Drawings

[0020] Figure 1 : Exploded view of the part [0021] Figure 2: Longitudinal section of part

[0022] Figure 3: Cross-sectional view of part

Description of Embodiments

[0023] Input water at 60 ° C (water fluid to transfer heat generated in the part) passes through the center of the lid (1 ) and enters the device. In order to prevent high thermal stress, the water should have a temperature of about 60 C. The material of the cover is technically selected in such a way that while tolerating high thermal stresses, it does not crack and has the ability to weld to copper, and in addition to all these properties, it does not rust.

[0024] The cap (2) separating the two parts of the flow from each other causes the flow of water inside the holes embedded in the copper body which is in direct contact with the heat source. The copper body (3) is an integrated intermediary between direct external heat on the one hand and heat-carrying water on the other. The outer surface (6) of this body will be in contact with slag.

[0025] The fluid separating tube (4) causes the water that enters from the holes of the copper piece (7) to move again towards the inlet near the copper wall to hit the cap (2) and is directed to the center of the same tube and from the other side of the piece. At the water outlet, a holder is installed in the cover (5) from which the water comes out.

[0026] The path of water movement inside the system is indicated in Figures 8, which is directed out of the innermost part of the piece (9).

Examples

[0027] This product is installed under the molten slag outlet of super heavy furnaces and its hydrogen inlet is taken from the outlet water of the panel and after circulating in this product and cooling it, it is transferred to the cooling towers.

Industrial Applicability

[0028] This product is used in super heavy steel furnaces and is used to guide molten slag into the pan. This equipment is placed at the exit of slag from melting super-heavy furnaces so that the slag exits the kiln and leaves the kiln after colliding with this part.

Claims

5 Claims

[Claim 1 ] An Integrated hollow copper electrode in the slag hole with thermal conductivity which consists of the following parts: a. Hollow copper body b. Water inlet and outlet cap c. Separating cap d. Fluid separator tube

[Claim 2] According to claim 1 , the inlet water enters the device with a temperature between 25 and 30 C from the center of the inlet cap and the cap separating the two flow sections from each other causes the water to flow into the holes embedded inside the integrated copper body with direct contact to the heat source.

[Claim 3] According to claims 1 and 2, the fluid separating tube causes the water that enters from the cavities of the copper body to move again towards the inlet near the wall, hitting the cap and being directed to the center of the tube and leaving the other side of the part and at the outlet of the water, a holder is installed in the outlet cap from which the water with a temperature between 30 to 35 C is exited.