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Functional Refractories
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Introduction

Together with Secondary Refining Process, Argon Injecting Technology is widely used these days. Purging Plug is a refractory used for Secondary Refining Equipment such as LF, AOD, VOD, etc. that plays a vital role in injecting Argon or Nitrogen gas into molten gas. The main functions are summarized below.

1. Accelerate the physical and chemical property of molten steel
2. Homogenization temperature and composition of molten steel
3. Enhance the purity of steel by floating non-metallic inclusion to the surface using gas

Ladle-tapping and stress induced by cold-gas blown into the Plug causes spalling and clogging problem in Purging Plug. We have strived to develop and improve the quality of Purging Plug for LF Ladle. As a result, we developed Al2O3-Spinel product with stable Slit, minimum hot-deformation and excellent spalling resistance. Our Plug is designed with optimal Slit structure to prevent backflow of molten steel and to ensure sufficient gas flow. It is excellent in argon stirring and high in resistance against erosion.

Layout

Purging Slit

Purging Slit plays a role of injecting Argon gas into molten gas. Shape of bubble and amount of gas injection can be adjusted depending on Slit shape and size.

Indicator

Indicator is made of porous material so Plug is visible with naked eyes, making it easy to identify during O2 Cleaning process that allows safer operation to be carried out.

Steel Cone

Steel Cone is tightly coupled with Plug body, so there is no leakage problem. It is made of excellent high temperature oxidation resistant material.

Castable

Castables are a High-Alumina Casting Refractories that is produced with excellent erosion-resistant and spalling-resistant materials.

Extraction Unit

Extraction Unit is applied when Hydraulic removal equipment is used to replace or remove the Plug. It can be mounted if requested by the user.

Porous Type

Porous Type Plug, produced by using pressers, have optimum pore distribution, so the pore distribution is uniform and purging rate is high.  This product not only has superior cleaning effect by O2 Cleaning, but has excellent performance at low-pressure as well.

PP-CONE (P) PP-72/90 PP-90/120

Size (mm)

150 230

Amount of Airflow  (Nl/min) at 1kg/cm2

 250 230

Round Slit Type

ound Slit Type Plug with cross-linked slit feature has a high purging rate, excellent permeability, and minimum steel infiltration.

PP-CONE (P) PP-ST375 PP-ST405 PP-ST470

Size (mm)

375 405 470

Amount of Airflow  (Nl/min) at 1kg/cm2

 215 210 200

Slot Type

Slot type Plug는 Slit이 각각 독립적으로 구성되어있어 통기특성이 우수하고 높은 내구특성을 가진다. 또한 슬릿 개수 조절에 의한 가스유량의 조절이 용이하다.

PP-CONE (P) PP-ST375 PP-ST405 PP-ST470

Size (mm)

375 405 470

Amount of Airflow  (Nl/min) at 1kg/cm2

 215 210 200

Specificcation

Purging Plug Seating Block
PP-CONE (P) PP-CONE (ST) PP-CONE (RD) Al2O3-Cr2O3 Al2O3-Spinel
Chemical Analysis (%) Al2O3 95 ≤ 92 ≤ 88≤ 90≤
CaO - 3 ≥ 3 ≥ 3 ≥
MgO 2 ≥ 5 ≥
Cr2O3 3 ≥ - 7≥ -
Bulk Density (g/cm3) 2.60 3.00 3.10 3.14
Apparent Porosity (%) 28 19 17 13
Cold Crushing Strength ( kg/cm2) 650 900 300 600
HMOR (kg/cm2) 1000℃ - 220 - -
1400℃ 32 230 - 160
Material Al2O3-Cr2O3 Al2O3-Spinel

THE INFORMATION STATED IN BASED ON THE BEST LABORATORY AND LITERATURE DATA AND IS NOT A WARRANTY OR A GUARANTEE. IT IS PRESENTED FOR CONSIDERATION ANDVERIFICATION ONLY,AND IS NOT TO BE USED FOR SPECIFICATION PURPOSE.

Flow Properties

Argon gas flowing through Purging Plug is directly proportional to pressure. However, this relation in hot condition can be affected by pressure of molten steel, thermal expansion of gas, and penetration of molten steel into Plug. During the operation in hot condition, gas flow is 1/3~1/5 times lower compared to operation in cold condition. Gas flow can be designed/adjusted to meet the customer needs.

at 1kgf/cm2

at 5kgf/cm2

< Flow Property for 100T Ladle (PP-RD375) >

Current status

Dongkuk Steel - Pohang Dongkuk Steel - Incheon KISCO KOSCO
140ton 100ton 120ton 70ton 120ton 100ton
Suppliers C DK DK DK DK DK DK
Material Al2O3-Cr2O3 Al2O3-Spinel Al2O3-Spinel Al2O3-Spinel Al2O3-Spinel Al2O3-Spinel Al2O3-Spinel
Type Slot type Round Slit
(Double Slit) 		Round Slit (Double Slit) Round Slit
(Double Slit) 		Round Slit
(Double Slit) 		Round Slit
(Double Slit)
 Round Slit (Double Slit)
Method Interpolation
Interpolation
Interpolation /Extrapolation
Interpolation
Interpolation
Interpolation Interpolation
Plug
Length (mm)		 470 375/520 375/470 470/520 470 470 470
Lifespan (ch) 40~45 60~65 55~60 60~65 15~20 50~55 30~35
Remarks 2 Sets Bubble Simultaneously