CFB Boiler Refractory
The working principle of CFB boiler is that: low calorific value fuels(coal gangue, inferior anthracite, etc) is crushed and charged into combustion chamber, the fuels is blew into fluidizing state by furnace bottom air blower, then fuel is combusted to supply heat. 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.
Fuel particles fluidizing speed is high, so they have strong washing abrasion to CFB boiler refractory lining. Besides, impurities in coal particles will react with lining refractory and have frequent thermal exchange, so the lining should suffer long term erosion, abrasion, stripping, impact, thermal stress and chemical corrosion, the service life of CFB boiler is greatly affected.
Therefore, CFB boiler refractories need to have high mechanical strength, excellent abrasion resistance, good corrosion resistance, good thermal shock resistance and so on. Low cement, ultra low cement abrasion resistant castable and no cement wear resistant castable are usually used in circulating fluidized bed boiler.
Refractory Bricks
CFB boiler refractory bricks mainly include:
high alumina bricks,
clay bricks and acid-proof bricks. High alumina bricks and clay bricks used in CFB boiler have good high temperature volume stability, good abrasion resistance, good molten slag erosion resistance, etc. The main applications parts of high alumina bricks and fireclay bricks are return feeder, economizer sidewalls, mixing chamber inner wall, etc. acid proof bricks are mainly used at flues, chimney inner lining and so on.
CFB Boiler Refractory Bricks Physiochemical Indexes
| Item |
High alumina bricks |
Clay bricks |
Acid proof bricks |
| Al2O3 % |
70 |
80 |
90 |
40 |
45 |
/ |
| SiO2 % |
25 |
15 |
5 |
/ |
/ |
≥65 |
| Cold crushing strength Mpa |
60 |
80 |
100 |
25 |
30 |
≥15 |
| Cold modulus of rupture Mpa |
10 |
12 |
14 |
/ |
/ |
/ |
| Refractoriness under load Ti ℃ |
1450 |
1550 |
1650 |
1350 |
1400 |
/ |
| Thermal shock resistance times(900℃, water cooling) |
15 |
20 |
30 |
/ |
/ |
/ |
| Abrasion resistance /cm3 |
≤10 |
≤8 |
≤6 |
/ |
/ |
/ |
| Thermal conductivity w.(m·K)-1 |
1.5 |
1.5 |
1.5 |
/ |
/ |
/ |
| Max. working temperature ℃ |
1400 |
1500 |
1600 |
/ |
/ |
1000 |
Steel Fibre Reinforced Castable
Steel fibre reinforced castable has good mechanical strength, good wear resistance, thermal shock resistance, low thermal conductivity, good molten slag permeation resistance, corrosion resistance and excellent workability. Steel fiber reinforced castable casted lining has good integrity, it is mainly used at high temperature wear resistant parts of CFB boiler, especially suitable for parts where have complex structure, for example, refractory belt, return feeder, mixing chamber top, etc.
Besides, DCB boiler cyclone separator, furnace hearth dense phase zone, furnace hearth outlet, water cooling air chamber, ash cooler, return feeder, kindling air channel and other severe abrasion parts can also select abrasion resistant castable.
Steel Fibre Reinforced Castable Physiochemical Indexes
| Item |
1 |
2 |
3 |
4 |
5 |
6 |
| Al2O3 % |
60 |
68 |
75 |
78 |
85 |
95 |
| SiO2% |
/ |
/ |
20 |
/ |
10 |
2 |
| CaO % |
/ |
/ |
2.5 |
/ |
1.5 |
2 |
| Bulk density g/cm3(110℃) |
2.4 |
2.5 |
2.6 |
2.7 |
2.85 |
2.95 |
| Crushing strength Mpa(1100℃) |
≥80 |
≥90 |
≥100 |
≥100 |
≥150 |
≥130 |
| Modulus of rupture Mpa(1100℃) |
≥10 |
≥11 |
≥12 |
≥14 |
≥21 |
≥22 |
| Thermal shock resistance(900℃, water cooling)/times |
/ |
/ |
/ |
20 |
20 |
20 |
Abrasion Resistant Castable Physiochemical Indexes
| Item |
J60 |
J65 |
J70 |
J75 |
J80 |
J85 |
| Al2O3 % ≥ |
60 |
65 |
70 |
75 |
80 |
85 |
| Bulk density g/cm3(110℃，24h) |
2.4 |
2.5 |
2.6 |
2.7 |
2.8 |
2.9 |
| Crushing strength Mpa(1000℃, 3h) |
≥80 |
≥90 |
≥100 |
≥100 |
≥100 |
≥110 |
| Modulus of rupture Mpa(1000℃, 3h) |
≥9 |
≥11 |
≥13 |
≥13 |
≥14 |
≥14 |
| Linear change rate %(1000℃, 3h) |
±0.3 |
±0.3 |
±0.3 |
±0.3 |
±0.3 |
±0.3 |
| Thermal shock resistance(1000℃, water cooling)/times |
≥20 |
≥20 |
≥20 |
≥18 |
≥18 |
≥18 |
| Cold abrasion resistance/cm3 |
≤9 |
≤8 |
≤7 |
≤7 |
≤7 |
≤7 |
| Max. working temperature ℃ |
1400 |
1450 |
1500 |
1550 |
1600 |
1650 |
Wear Proof Plastic Mix
Wear proof plastic mix main raw materials are high alumina bauxite, corundum and mullite, high temperature inorganic liquid binder. Through mixing and squeezing, wear resistant plastic mix is produced. Wear proof plastic mix has the advantages of good plasticity, good workability, quick patching, high strength and good abrasion resistance, excellent thermal shock resistance, cracking resistance, good air-tightness and so on. Wear proof plastic mix is main used for the patching and local ramming of CFB boiler, such as cyclone separator, inlet flue and outlet flue, etc.
Wear Proof Plastic Mix Physiochemical Index
| Item |
NK-48 |
NK-60 |
NK-70 |
NK-75 |
NK-75A |
NK-90 |
| Al2O3 % ≥ |
48 |
60 |
70 |
75 |
75 |
90 |
| Refractoriness ℃≥ |
1760 |
1780 |
1790 |
1790 |
1790 |
1790 |
| Modulus of rupture Mpa(110℃,24h) |
≥12 |
≥12 |
≥12 |
≥12 |
≥8 |
≥10 |
| Thermal shock resistance(900℃, water cooling)/times |
/ |
/ |
/ |
/ |
/ |
>40 |
| Plasticity index % |
15~40 |
15~40 |
15~40 |
15~40 |
20~40 |
20~30 |
| Cold abrasion resistance/cm3 |
/ |
/ |
/ |
/ |
≤8 |
≤7 |
Micro Expansion Plastic Refractory
Micro expansion plastic refractory has strong cold plasticity, large adhesion force, high strength after natural drying, micro expansion at high temperature, high refractoriness, good sealing performance, convenient application, etc.
Micro Expansion Plastic Refractory Physiochemical Index
| Item |
Test condition |
Value |
| Bulk density g/cm3 |
1000℃, 3h |
≤2.1 |
| Crushing strength Mpa |
1000℃, 3h |
≥20 |
| Modulus of rupture Mpa |
1000℃, 3h |
≥8 |
| Refractoriness ℃ |
/ |
≥1710 |
| Plasticity index % |
20~40℃ |
14~40 |
| Linear change rate % |
1400℃, 3h |
2~2.5 |
| Refractoriness under load temperature ℃ |
0.6% deformation |
≥900 |
| Thermal conductivity W/(m·K) |
350℃ |
1.08 |
Corrosion and Abrasion Resistant Ramming Mix
Corrosion resistant ramming mix main characteristics are : high rigidity, wear resistant to solid particles and liquid slag, good resistance to slag corrosions, can reduce weak alkali corrosion to furnace lining, good slag adhesion property, low linear expansion coefficient, good thermal shock resistance and high thermal conductivity. Corrosion and abrasion resistant ramming mix is mainly used at circulating fluidized bed boiler parts where suffers long term wearing and corrosion.
Corrosion and Abrasion Resistant Ramming Mix Physiochemical Indexes
| Item |
Test condition |
Value |
| SiC % |
/ |
65~80 |
| Fe2O3 % |
/ |
≤1.5 |
| Bulk density g/cm3 |
110℃, 24h |
2.4~2.7 |
| Crushing strength Mpa |
110℃, 24h |
≥28 |
| Modulus of rupture Mpa |
110℃, 24h |
≥12 |
| Refractoriness ℃ |
/ |
1730~1750 |
| Linear change rate % |
1200℃, 3h |
+2.0 |
