High thermal conductivity silica brick
PRODUCT SPECIFICATIONS
GB STANDARDS
Items | (YB/T2608-2012) Ordinary Silica Brick | High Thermal Conductivity Brick （Luqiao Standard） |
SiO2 % ≥ | 94.5 | 95 |
Al2O3 % ≤ | 1.2 | 1.0 |
Fe2O3 % ≤ | 1.2 | 0.8 |
CaO % ≤ | 3.0 | 2.5 |
Apparent porosity % ≤ | 24 | 20 |
Bulk density g/cm3 ≥ | 1.8 | 1.85 |
True density g/cm3 ≤ | 2.34 | 2.335 |
Cold crushing strength MPa ≥ | 28 | 60 |
Permanent liner change 1450℃, 2h | 0~+0.2 | 0~+0.2 |
Refractoriness under load 0.2 MPa ℃ | 1650 | 1660 |
Thermal expansion coefficient ambient ～ 1000 ℃ ≤ | 1.30 | 1.25 |
Residue Quartz % ≤ | 1.5 | 0.5 |
Thermal Conductivity 1100℃ W/m.k ≥ | 1.9 | 2.3 |
The benefits of COB heating walls by adopting the new brick mainly in 2 aspects.
Benefits of coking chamber heating wall using high thermal-conductivity silica brick in coke oven
ENERGY SAVING
The increase of thermal conductivity coefficient means the decrease of the temperature gradient needed when transferring the same thermal energy from the heating wall to the carbureting chamber. This also means that the temperature of heating wall (or flue) can be lowered, so with the consuming gas for heating, with the carburetion time (coke oven output) unchanged. Theoretically primary calculated, the temperature of flue can be lowered by 40℃ , and the gas consumed for heating saved 3% at least.
NOX
NOX Emission Reduction. The NOX content in the combustion exhaust gases can be reduced effectively when the temperature of heating wall flue falls. E.g. the temperature of flue drops 40 ℃ , the NOX in exhaust gases can be reduced about 80ppm according to the schematics of the generation of NOX and test results from German COB.
Therefore, it’s of a new technology by adopting high thermal-conductivity silica brick in COB heating walls for the sake of energy saving and emission reduction. However, the mass benefits still need the verification after put into production.
Economy value of COB heating walls by using high thermal conductivity bricks
Calculated with production cost, the price of high thermal conductivity bricks is CNY 600 higher than common silica bricks each ton. For example, if total quantity of 55 ovens heating wall bricks for one top in-charge COB of 6m is 2468 tons, the investment will be increased by CNY 1,480,000 if using high thermal conductivity bricks.
When adopted with high thermal conductivity bricks, if 3% fuel gas saved as estimated, it will save 2,900,000 m3 fuel gas or CNY 1,740,000 with unit price CNY 0.6/m3.
Obviously, it will bring great economic value by adopting high thermal conductivity brick in
COB heating walls.