Circulating Fluidized Bed Boiler Refractory
CFB boiler has strong adaption to different kinds of coals. In CFB boiler, coal powders recycling times is large, so its combustion rate can reach to 98%. CFB boiler also features in high thermal efficiency, good desulfurization effect, low air pollution and so on, so it is an ideal thermal equipment for steam supply equipment, heat supply and power generating.
CFB boiler refractories need to have high mechanical strength, excellent abrasion resistance, good corrosion resistance, good thermal shock resistance and so on.
High Alumina Castable
High strength high alumina castable has good permeation resistance, erosion resistance , impact resistance, abrasion resistance, good mechanical performance and so on. High alumina castable such as bauxite cement high alumina castable, phosphate castable and aluminate castable are widely used in CFB boiler furnace arch, air chamber, economizer protection plate, fire door and so on.
| Item |
Bauxite cement castable |
Phosphate castable |
Aluminate castable |
| Al2O3 % |
75 |
65 |
75 |
| Refractoriness ℃ |
1730 |
1750 |
1770 |
| Reheating linear change rate % |
-0.3 |
-0.02 |
-0.3 |
| Crushing strength Mpa (1100℃, 4h) |
50 |
60 |
65 |
| Modulus of rupture Mpa(1100℃, 4h) |
6 |
8 |
10 |
| Binding agent property |
Water setting |
air setting |
Water setting |
| Max. working temperature ℃ |
1300 |
1200 |
1400 |
Lightweight Insulating Bricks
Lightweight insulating bricks used in CFB boilers include cenosphere insulating bricks, cement perlite insulating bricks, diatomite insulating bricks. The have good creep resistance, relatively high modulus of rupture and small reheating linear change rate, low thermal conductivity and good insulating performance.
| Item |
Ultra light cenosphere insulating bricks |
Cement perlite insulating bricks |
Diatomite bricks |
| Al2O3 % |
35~40 |
35~40 |
10~15 |
10~15 |
25 |
25 |
| Bulk density g/cm3 |
0.4 |
0.6 |
0.4 |
0.6 |
0.4 |
0.6 |
| Cold crushing strength Mpa |
1 |
1.5 |
0.5 |
0.8 |
0.6 |
0.8 |
| 900℃ linear change rate % |
1 |
1 |
2 |
2 |
2 |
2 |
| Thermal conductivity W/(m·K) (350℃) |
0.15 |
0.20 |
0.06 |
0.08 |
0.13 |
0.17 |
| Working temperature ℃ |
500 |
600 |
200 |
200 |
300 |
300 |
Lightweight Insulating Castable
Lightweight insulating castable has low density, proper mechanical strength, good heat insulating property and good workability( casting, vibrating, ramming or pre-casting), good integrity and so on. Light insulating castable are widely used as insulating lining of boiler furnace top and furnace walls.
| Item |
Clay insulating castable |
Perlite insulating concrete |
Diatomite insulating concrete |
| Al2O3 % |
30 |
20 |
15 |
| Density g/cm3 |
0.5 |
0.4 |
0.4 |
| Modulus of rupture Mpa 500℃ |
0.6 |
1.0 |
0.5 |
| Thermal conductivity W/(m·K) |
≤0.20 |
≤0.10 |
≤0.06 |
| Max. working temperature ℃ |
900 |
600 |
600 |
Aluminum Silicate Fibre Insulating Materials
The application of different specifications of aluminum silicate fibre boards, aluminum silicate fiber wool, asbestos board, asbestos rope, asbestos board can greatly improve CFB boiler air-tightness, insulating property and so on. The are mainly used for boiler sealing and heat insulating parts, such as water wall, hot air pipes and industrial furnace wall surfaces.
Aluminum Silicate Fibre Insulating Material Physiochemical Indexes
| Item |
Aluminum silicate fibre felt -A |
Aluminum silicate fibre felt –B |
High alumina fiber felt |
Zirconia aluminum silicate fiber felt |
Aluminum silicate fiber board |
Composite silicate board |
| Al2O3 % |
46~50 |
50~54 |
60~64 |
≥38 |
/ |
/ |
| SiO2 % |
58~53 |
44~48 |
34~38 |
≥15(ZrO2) |
/ |
/ |
| Fe2O3 % |
≤1.2 |
≤1.0 |
≤1.0 |
≤1.0 |
/ |
/ |
| Fibre dia. μm |
1~4 |
1~4 |
1~4 |
2~4 |
/ |
/ |
| Density g/cm3 |
0.15~0.25 |
0.15~0.25 |
0.2~0.3 |
0.095~0.15 |
0.13 |
0.05 |
| Shot content % ≤ |
4 |
4 |
4 |
10 |
/ |
/ |
| Porosity % |
≥80 |
≥80 |
≥80 |
/ |
/ |
/ |
| Heating shrinkage % |
≤4 |
≤4 |
≤4 |
≤3 |
/ |
/ |
| Thermal conductivity W/(m·K) |
≤0.045 |
≤0.040 |
≤0.045 |
≤0.055 |
0.035 |
0.045 |
| Max. working temp. ℃ |
1100 |
1000 |
1000 |
1250 |
900 |
600 |
Expansile Perlite Insulating Products
The main composition of expansile perlite insulating products is expansile perlite. Expansile perlite products include boards, tube shells and so on, their working temperature is between 50~900℃. Expansile perlite insulating products have excellent heat insulating property, they are widely used for the sealing and heat preservation of CFB boilers.
Expansile Perlite Insulating Products Physiochemical Index
| Item |
Index |
| Bulk density g/cm3 |
0.2 |
0.25 |
0.3 |
0.35 |
| Thermal conductivity W/(m·K) (250℃) |
≤0.056 |
≤0.064 |
≤0.072 |
≤0.080 |
| Crushing strength Mpa |
≥4 |
≥5 |
≥5 |
5 |
| Water content |
≤2 |
≤2 |
≤3 |
≤4 |
| Working temperature |
50~900 |
Mortar & Slurry & Coating Materials
According to power plant boiler and chimney working condition, different kinds of refractory mortar, slurry and coating materials are used for the masonry of boiler and chimney. Refractory mortar should have strong adhesion force, good workability, no shrinkage after drying, good moisture and water proof performance, good sealing ability, etc.
Refractory Mortar, Slurry and Coating Materials Physiochemical Indexes
| Item |
Acid proof mortar |
Phosphate mortar |
Clay mortar |
Wear proof mortar |
Anti-corrosion coating material |
Silicate coating material |
| Al2O3 % |
≤25 |
≥65 |
≥65 |
≥80 |
/ |
/ |
| SiO2 % |
≥65 |
≤30 |
≤50 |
≤15 |
/ |
/ |
| Crushing strength Mpa |
25 |
40 |
15 |
60 |
20 |
20 |
| Bulk density g/cm3 |
1.7 |
2.4 |
1.8 |
2.8 |
1.6 |
1.8 |
| Modulus of rupture Mpa |
4 |
10 |
5 |
12 |
/ |
/ |
| Initial setting time |
4h |
8h |
4h |
/ |
/ |
/ |
| Max. working temperature ℃ |
1000 |
1300 |
1200 |
1600 |
600 |
200 |
CFB Boiler Slurry Physiochemical Indexes
| Item |
Clay slurry |
High alumina slurry |
Aluminum zirconia slurry |
Silicon carbide mullite slurry |
High alumina insulating slurry |
Magnesia slurry |
| Al2O3 % ≥ |
45 |
75 |
ZrO2≥6 |
Al2O3 +SiC ≥80 |
48 |
MgO ≥82 |
| Refractoriness ℃ ≥ |
1710 |
1790 |
1790 |
1790 |
/ |
1790 |
| Modulus of rupture Mpa(110℃,24h)≥ |
1 |
1 |
1 |
1 |
1 |
1 |
| High temperature Modulus of rupture Mpa |
≥3 |
≥4 |
≥4 |
≥2 |
≥3 |
≥3 |
| 1200℃ |
1400℃ |
1400℃ |
1000℃ |
1500℃ |
1500℃ |
| Setting time/ min |
1~3 |
