The characteristics of ceramic fibres are a remarkable combination of the properties of refractories and traditional insulation material.
1. Lower Thermal Conductivity
The low thermal conductivity - 0.1 kCal/m hour deg C at 600 °C for 128 kg/m3 density blanket
- allows construction of thinner linings with the same thermal efficiency as that of conventi onal refractories. Hence, for the same outer envelope dimension the furnace volume is much
higher. It is 40 % more effective than good quality insulation brick and 2.5 times better than asbestos product. Insulating property of ceramic fibre is better than calcium silicate product.
2. Light Weight
Average density of ceramic fibre is 96 kg/m3. It is one tenth of the weight of insulating brick and one third that of asbestos / calcium silicate boards. For new furnaces structural supports can be reduced by 40%.
3. Lower Heat Storage
Ceramic fibre linings absorb less heat because of lower density. Furnace can be heated and cooled at faster rates. Typically the heat stored in a ceramic fibre lining system is in the range of 2700 - 4050 kCal/m2 (1000 - 1500 Btu/Ft2) as compared to 54200-493900 kCal/m2 (20000 - 250000 Btu/Ft2) for conventionally lined system.
4. Thermal Shock Resistant
Ceramic fibre lining resist thermal shock due to their resilient matrix. Also faster heat up and cool down cycles are possible thereby improving furnace availability and productivity.
5. Chemical Resistance
Ceramic fibre resist most of the chemical attack and is unaffected by hydrocarbons, water and steam present in flue gases.
6. Mechanical Resilience
This property permits fibre lined furnaces to be shop fabricated and shipped to site in assembled form without fear of damage.
7. Low Installation Cost
No special skills are required as application practices are standardised. Fibre linings require no dry out or curing times and can be heated to the capacity of the burners after installation is completed without concern for cracking or spalling.
8. Simple Maintenance
In case of physical damage the defective section can be quickly removed and a replacement piece added. Whole panel sections can be prefabricated for fast installation with minimal down time.
9. Ease of Handling
All product forms are easily handled and most can be quickly cut with a knife or scissors. Vacuum formed products may require cutting with a band saw.
10. Thermal Efficiency
The low thermal conductivity of ceramic fibre can be advantageously made use of by the lesser lining thickness and reduced furnace volume. The fast response of ceramic fibre lined furnace also allows for more accurate control and uniform temperature distribution within the furnace. The other advantages offered by ceramic fibre are summarized below:
· Light weight furnace
· Simple steel fabrication work
· Low down time
· Increased productivity
· Additional capacity
· Low maintenance cost
· Longer service life
· Higher thermal efficiency
· Faster response.
Fibre in concrete is used to control plastic shrinkage cracking and drying shrinkage cracking.
BalasHapus