Application and Technology Research of HM-HRC Technology on Hot Stove Regeneration of BF One time investment. Takes back within half a year. Benefits for 30 years. Shandong Huimin Science & Technology Co,. Ltd. Jinan, Shandong, China Shandong Huimin Science & Technology Co,. Ltd. Jinan, Shandong, China

Brief Introduction of Inventor ： Huimin Zhou, lady, board chairwoman of Shandong Huimin Science and Technology CO., LTD. Postgraduate, engineering technology application researcher, senior engineer, subsidy beneficiary of the State Council Government. National 12th and 13th Antarctic Expedition Member. The foreign nationality expert member of American Iron & Steel Institute. She obtained the bachelor degree from Beijing Steel College in January 1982 and master degree of business administration from Southern Cross University of Australia in March She has always been engaged in the technique research of material and material surface, obtained more than 20 scientific achievements, 11 patents, published 15 academic papers both in China and abroad. She is committing herself to the High Radiative Coating Technology Research at present. The inventor of High Radiative Coating Technology ， a new inventive technology which integrates metallurgy, material and chemical to one subject, it is a breakthrough in iron making and energy saving technology which makes the technology keep the first level in the world.

HRC Tech ( High Radiative Coating Tech ） coats a high radiative rate material on the material surface which strengthen the heat radiation absorption and radiation ability, improve the radiation heat transfer efficiency. HRC Tech ( High Radiative Coating Tech ） coats a high radiative rate material on the material surface which strengthen the heat radiation absorption and radiation ability, improve the radiation heat transfer efficiency. What is HM-HRC Tech ? What is HM-HRC Tech ?

HM-HRC is a surface treatment tech. Surface treatment tech. is a system engineering: Surface coating, surface structure, stress state and chemical property reform in order to obtain a desire surface quality. The coating tech. consumes few coating material, obtains satisfactory results including the high economic benefit due to without operation cost etc.

Heat transfer models ： convection, radiation, conduction. The temperature of hot stove is 1300 ℃， radiative heat transfer account to 85% of the gross heat flux since the high temperature dissociative carbon which was generated during the gas combustion has strong radiative capability. Based on the law of Steifen-Bolzman: E=ε0 C0 （ T 100 ） 4 Principle of HM-HRC Tech.

Radiative rate ε Wavelength / μm ４ ３２１３２１ Fig.1 Spectrum radiative rates of diverse material 1. Clay castables 2. High-alumina bricks 3. Clay refractory bricks 4. Higher radiative rate coating ０ ２ ４ ６ ８ １０ １２ １ ~ 5 um wave range. For example, 76% and 85% of the radiation energy concentrate in the wave range when the temperature reach to 1000 ℃ and 1300 ℃ respectively. The radiative rate of common refractory is low in this wave range (fig 1), in contrast the high radiative rate coating has high emissivity in 1 ~ 15 μmwave range. Most of the high temperature radiation energy concentrate in 1 ~ 5 um wave range. For example, 76% and 85% of the radiation energy concentrate in the wave range when the temperature reach to 1000 ℃ and 1300 ℃ respectively. The radiative rate of common refractory is low in this wave range (fig 1), in contrast the high radiative rate coating has high emissivity in 1 ~ 15 μm wave range. Principle of HM-HRC Tech.

The radiative rate of common refractory is 0.6 ~0.8 under room temperature and decreases obviously as the temperature increase. But the radiative rate of high radiative coating is always keeping above 0.9. The radiative rate of common refractory is 0.6 ~0.8 under room temperature and decreases obviously as the temperature increase. But the radiative rate of high radiative coating is always keeping above 0.9. Principle of HM-HRC Tech. Radiative rate ε The effects of temperature on the radiative rate of materials Ceramic fibre Common refractory liner Higher radiative rate coating 1# Higher radiative rate coating 2# Temperature / ℃

Principle of HM-HRC Tech. According to the law of Geerhofu: the absorption rate ( the black degree ) is equal to the radiative rate. It means the absorptive ability is improved when the emissivity of material surface increased. According to the law of Geerhofu: the absorption rate ( the black degree ) is equal to the radiative rate. It means the absorptive ability is improved when the emissivity of material surface increased.

Three Application Models of HRC Application Mode I: to Use High Absorption and High radiation When the HRC is used on the lining of industrial furnaces, such as, reheating furnaces for rolling mills and glass furnaces, the heat absorption of linings is increased (about 60% of heat absorption of objective heated is from the lining radiation) and large amount of heat that cannot be transferred through the external wall of furnace will change into the heat with 1~5μm wave length radiating into the hearth. The heat with 1~5μm wave length When the HRC is used on the lining of industrial furnaces, such as, reheating furnaces for rolling mills and glass furnaces, the heat absorption of linings is increased (about 60% of heat absorption of objective heated is from the lining radiation) and large amount of heat that cannot be transferred through the external wall of furnace will change into the heat with 1~5μm wave length radiating into the hearth. The heat with 1~5μm wave length can be easily absorbed by the objectives heated, such as steel billet, so the heat efficiency of furnace can be improved.

Three Application Models of HRC Application Mode II: to Use the High Absorption When the HRC is used on the external wall of boiler pipes, vertical fire channel and insulation walls of coking chambers in coke oven, the heat absorption capacity of external wall of boiler pipes and insulation wall are improved, and so with the heat dynamics to the water and coking chamber. When the HRC is used on the external wall of boiler pipes, vertical fire channel and insulation walls of coking chambers in coke oven, the heat absorption capacity of external wall of boiler pipes and insulation wall are improved, and so with the heat dynamics to the water and coking chamber.

Three Application Models of HRC Application Mode III: To use the features of high absorption, high regeneration; high radiation and high heat emission. The HRC is used on the regenerator, such as surface of checker brick. Through the forced radiative heat exchange, the HRC improved the surface temperature of regenerative body, increased the temperature difference inside and outside of regenerative body, improved the heat absorption speed and volume of regenerative body during temperature increasing, and improved the heat emission speed and volume during temperature reducing, therefore, the blast temperature is improved.

Steel industry is a energy intensive industry and iron making process in BF takes over 60% of the gross energy consumption in steel company. High temperature blast has been used in BF since 1828 in America. The theoretic and experimental results indicated that high temperature blast not only plays a specific role in reducing coke rate, increasing yield and improving the quality of pig iron, but also increase the pulverized coal injection rate since high temperature blast improving coal combustion efficiency. That is to say, higher temperature blast lead to lower energy consumption and higher yield. So the BF researchers engaged in improving the blast temperature. Hot Stove of BF

Hot stove is a heat exchanger which can heat the air up to more than 1200 ℃ and provide blast for BF. Every BF is equipped with 3 ～ 4 hot stoves with regeneration (check brick or regenerative ball) inside it. Heat the regeneration by use of gas from BF, coke oven and converter furnace which was generated during the iron making process. Then the air to the BF was heated by the regeneration thermal storage which makes the air up to 1000 ℃. BF for iron making

The research on improving the blast temperature of hot stove mainly concentrated on material qualities of regeneration, construction design of hot stove, by use of high performance fuel both domestic and abroad.

HRC on the regeneration surface of hot stove of BF is a new technology which improves the blast temperature of hot stove of BF in iron making, and reduces the fuel consumption.

Blend the ultra fining technology treated powder with the prepared high temperature adhesive Preparation of HRC ( “ Jie Neng Wang ” Nanometer High Temperature Far-infrared Energy Saving Coating Add few surface active agent High-speed mechanical agitation Viscous fluid high radiativity energy saving coating

This picture is the TEM (transmission electron microscope) graph of high emissivity material, the particle is nm. The particle is grinded to nanometer grade （ maxmium 2μm ） by use of ultra fining technique which makes the coating infiltrate into the matrix and form the transitional layer thus to improve the adhesive capability. Micro image of coating powder

Cleaning the checker brick Spraying adhesives Coating by soaking (2 ～ 3 seconds) Drying or Solidifying while a stove drying The processes for the coating preparation on the (checker brick) regeneration of hot stove:

1.Interface theory ， using the pre-treatment technique in coating preparation. Pre-treatment adhesive reduced the surface tension, improved the adsorptive capacity of matrix. Technology for improving the adhesive force of coating ： 2. Ultra fining technique ， nanometer coating particles infiltrate into the cavity of matrix, form the infiltration combination between coating and matrix. Keeping the coating unshed

It could be seen that there is some change in color, which shows the coating material has infiltrated into the brick about 3 mm thickness.

Infiltrated depth is 3 mm The thickness of the coating is about 0.3 mm The small coating particles infiltrate into the matrix, form the coating gathering area and present black particle in micro structure. None chemical reaction with the matrix. Micro structure of the checker brick section

Coating and matrix formed the coating-transition layer-matrix construction, the formation of transition layer is due to the coating infiltrate into the matrix which guaranteed the fine adhesive capability between coating and matrix.

The surface of siliceous brick before coating (×25) brick after coating (×25) Fine surface coating prevent the brick to be break

The surface of high-alumina brick before coating (×25) brick after coating (×25) Fine surface coating prevent the brick to be break

The effects of HM-HRC on the physical property of the refractory The effects of the coating on alumina brickspecimenVolumeDensity(g/cm3) Pore rate (%) Compression strength （ MPa ） Break strength (MPa) Linear change rate (%) Without coating With coating

The effects of HM-HRC on siliceous brick 1300 ℃ ×3h VolumeDensity(g/cm3) Pore rate (%) The strength of compression （ MPa ） The break strength (MPa) Linear Linear Change rate (%) Without coating With coating

The softening temperature with loading and the distortion rate contrast between without coating and with coating silica brick Softening temperature with loading (0.2MPa, 0.6%), ℃ High temperature distortion rate (1430 ℃ ×50h), % Without coating With coating >

The nano/micro coating materials infiltrated in the cavity of the brick surface which decreased the pore rate and high temperature distortion rate, increased the volume density, compression strength, break strength and softening temperature with loading. All these above are good for prolonging the service life of the brick in hot stove of BF.

The influence of coating on the heating and cooling speed and thermal storage capacity of refractory with coating ——high summit temperature ， low heat remnant. Without coating——low summit temperature ， more heat remnant. blue shadow——heat release of refractory with coating during temperature increasing. Red shadow——heat release of refractory without coating during temperature increasing. 21

Measuring the influence of coating on the thermal storage volume and unit energy saving efficiency of checker brick at medium temperature （ 800 ℃ ) and high temperature （ 1200 ℃） by use of calorimeter method. Calorimeter method means measuring the heat quantity of water by use of calorimeter (Q water), the heat quantity of Q specimen is equal to Q water. The influence of coating on the thermal storage volume and unit energy saving efficiency of checker brick Fig 4 the energy saving effect of checker brick under different states. Water quenching Energy saving efficiency % 800 ℃ 1200 ℃ Unit energy saving efficiency τ=m τ=m without coating （ Q with coating/m with coating – Q without coating/m without coating ） /Q without coating×100% Reflect the improvement thermal storage capacity of coating of the matrix.

The energy saving efficiency of coating at medium temperature is less than that at high temperature which indicates that the mechanism of coating improving heat conduction ability of refractory is mainly concentrated on improving the absorption and radiation ability of refractory surface. Trialed by many times of water quenching, there is no obvious change in the improvement of thermal storage capacity which indicate that the application effect is basically tallies between short period and long period application.

HM-HRC has been used in 88 hot stoves of BF (300 ～ 3200m3) since the invention of High Radiation Energy Saving Coating on checker brick of hot stove in HM- HRC increased the blast temperature for more than 15 ℃, prolonged the air supply time for 10%, decrease the gas consumption for more than 7% and the temperature of flue gas average decreased for more than 10 %, or integrates all the benefits thus improved the condition of hot stove. Industrial application

Temperature distribution of checker brick in 1750 m 3 BF of Jinan Steel Company ( ) Without coating —— low wave, low thermal storage With coating —— high wave, high thermal storage 25

Temperature distribution of the brick in 1750 m 3 BF ( ) （ put into production for three years and seven months ） Without coating With coating

HM-HRC on checker brick in No.3 Hot Stove of No.6 BF in Changzhi Steel Co. HM-HRC on checker brick in No.3 Hot Stove of No.6 BF in Changzhi Steel Co. 3# low temperature of exhaust gas ( narrow wave summit) 26

Temperature distribution of checker brick in 1# and 2# hot stove with coating and the 3# without coating of hot stove in 1080 m3 BF built by Shandong Shiheng Steel Company Temperature distribution of checker brick in 1# and 2# hot stove with coating and the 3# without coating of hot stove in 1080 m3 BF built by Shandong Shiheng Steel Company

Shiheng1080m3 BF Hot Stove With coating higher temperature blast ， prolonging time blast Without coating lower temperature blast ， short time blast Without coating temperature of flue gas is higher With coating temperature of flue gas is lower 27

Improvement of thermal efficiency ① the noumenon thermal efficiency of hot stove 1#furnace ： = 3#furnace ： = ② thermal efficiency of hot stove 1# furnace ： = 3# furnace ： = =73.28% =81.26% =76.03% =78.32% Shiheng1080m3 BF Hot Stove

1 The blast temperature average of hot stove with coating is 25 ℃ higher than that without coating, the flue gas temperature average with coating is 13 ℃ less than the without coating. Reduce the energy consumption for 3%. 2 The gas combustion is more fully in the hot stove with coating which reduces the combustible components in flue gas, the heat loss of incomplete combustion reduced from 1.7% to 0.12% 。 3 The thermal efficiency of hot stove with coating is 5% higher than that without coating and the energy saving effect is obviously stable. Shiheng1080m3 BF Hot Stove

HM-HRC have been used in 88 hot stoves 序 号序 号序 号序 号 施工日 期 应 用 单 位 炉 型 Laiwu Steel Co. 2 # 1880M 3 BF2 # Hot Stove Jinan Steel Co. 2 # 1750M 3 BF2 # Hot Stove and 2 # 、 3 # Vault Shandong Tube Casting Co. 2 # 350M 3 BF 3 Hot Stoves Jinan Steel Co. 3 # 1750M 3 BF 3 Hot Stoves Laiwu Steel Co. 1 # 1080M 3 BF 2 # 、 3 # Hot Stoves Laiwu Steel Co. 2 # 1080 M 3 BF 3 Hot Stoves Laiwu Steel Co. 2 # 380 M 3 BF 3 Hot Stoves Yongfeng Steel Co. 1 # 、 2 # 450 M 3 BF 6 Hot Stoves Vault Handang Steel Co. 3 # 300 M 3 BF 3# Hot Stove Laiwu Steel Co. 2 # 750M 3 BF 3# Hot Stoves Jinan Steel Co. 1 # 350M 3 BF 2 # 、 3 # Hot Stoves Qingdao Steel Co. 1 # 380 M 3 BF 3 Hot Stoves Yongfeng Steel Co. 1080M 3 BF 2# Hot Stove Handang Steel Co. 3 # 300 M 3 BF 2# Hot Stove Handang Steel Co. 5 # 2000 M 3 BF 2# Hot Stove Tonghua Steel Co. 5 # 350M 3 BF3# Hot Stove Handang Steel Co. 1 # 300 M 3 BF2# Hot Stove Tonghua Steel Co. 3#350M3 B8# Hot Stove Changzhi Steel Co. 6#350M3 BF3# Hot Stove Tonghua Steel Co. 3#350M3 B8# Hot Stove Changzhi Steel Co. 6#350M3 BF3# Hot Stove

Ji Nan Steel Co. 2#350M3 BF2#,3#Hot Stoves Han dang Steel Co. 2#380M3 BF7# Hot Stove Shi Heng Steel Co. 1080M3 BF1#,2# Hot Stove Wei fang Steel Co. 4#1300M3 BF 3 Hot Stoves Tong hua Steel Co. 2560M3 BF 3 Hot Stoves Handan Steel Co. 6#380M3 BF 1#Hot Stove Handan Steel Co. （ Hanbao ） 3200M3 BF 3 Hot Stoves Xuan hua Steel Co. 2500M3 BF 1 Hot Stove Tong hua Steel Co. 1# 、 2#350 M3 BF 4 Hot Stoves Anyang Steel Co. 6#350M3 BF 4# Hot Stove Chang zhi Steel Co 6#350M3 BF 2# Hot Stove Shandong Fulun Steel Ld 1#1350M3BF 1# 、 2# Hot Stove Han dan Steel Co. （ Hanbao ） 3200M3 BF 3 Hot Stoves Tonghua Steel Co. 4# BF 3# Hot Stove Qingdao Steel Co 3# BF 3 Hot Stoves Anshan Steel Co N5#2580M3 BF 3 Hot Stoves Henan Hanyang Steel Co. 750m 3 Hot Stoves Vault Chang zhi Steel Co 1080M3 BF13 Hot Stove Tianjin Steel Co 2800m3 BF 3 Hot Stoves Handan Steel Co. 3200M3 2Hot Stove Chang zhi Steel Co 6#400M3 2#Hot Stove Chang zhi Steel Co 3#3500 M3 3Hot Stove Lianfeng Steel Co 2#450 M3 2Hot Stove

“ High Radiative Coating Technology ” has been listed in science and technology sustained technology of Science and Technology Ministry- System Technics Technology on Super-large-sized Blast Furnace. This technology obtained third prize of 2008 National Metallurgy Science and Technology Award, first prize of National Association of Industry and Commerce Science and Technology Progress Award, first prize of Jinan Science and Technology Innovation Award.

High radiative coating on hot stove of BF has passed the authentication of the Expert Committee in which Mr. Shi Chang-Xu, a senior academician, is in charge of it. Authentication results: a new inventive technology which integrates metallurgy material and chemical to one subject, it is a breakthrough in iron making and energy saving technology which makes the technology keep the first level in the world, it deserves highly generalization in the application on hot stove of BF.

4 Chinese patents have been obtained in the preparation method, construction technique and regenerator with coating. The patents application in the US, Japan, Germany, Russia, Korea and India are undergoing. The US, Japan and Germany have already officially announced. 4 Chinese patents have been obtained in the preparation method, construction technique and regenerator with coating. The patents application in the US, Japan, Germany, Russia, Korea and India are undergoing. The US, Japan and Germany have already officially announced. Property right of innovation

Nanometer High Radiative Coating on the regeneration of hot stove is a new technology with low investment and without operation cost which can increase yield and reduce energy consumption. One time investment, takes back within half a year, benefits for 30 years. This technology opened a simple and convenient way for further improving the blast temperature of hot stove of BF, and has broad prospect of application.