Fluidized Bed Garbage Incinerator Refractory
Fluidized bed garbage incinerator features in high thermal intensity, compatible to low calorific value and high water content garbage. As its heat regeneration quantity is large, almost auxiliary combustion is needed during incinerating. Garbage grains burn in suspension state, the burning process is similar to fluidized bed boiler. The incineration temperature of fluidized bed incinerator is about 750~870℃, the materials(carrier and waste residue) in the furnace appears boiling state, so incinerator lining material should be high temperature proof and abrasion resistant.
Fluidized bed garbage incinerator adopts particle shaped sand as high temperature heat resource carrier, large capacity air blower continuously blow high temperature air into incinerator to make the sand appear boiling state, meanwhile, the boiled sand is heated to 600~800℃ by heating burner. Crushed garbage is continuously loaded into high temperature boiling sand, dried, preheated and burned. As the boiling sand have large heat capacity, and boiling layer temperature is even, the whole process from loading to burning is finished in a flash, low calorific value garbage can totaled incinerated in fluidized bed garbage incinerator.
Fluidized bed incinerator is usually composed of garbage loading inlet, air box, air diffusion plate, sand bath, burner, melting chamber, dust collection nozzle, etc. waste gases is transported into air cooling chamber by connection tube. Generally speaking, fluidized bed garbage incinerator has relatively low process capacity, daily process quantity is below 100t, the max. is 200t/day. It is usually used as small and middle size citizen garbage incinerator, sewage sludge incinerator and ordinary industrial waste incinerator.
Incinerator Refractory Typical Performance
| Item |
High alumina plastic refractory |
Alumina SiC brick |
High alumina castable |
Fireclay castable |
| Al2O3% |
60 |
2 |
48 |
45 |
| SiO2% |
32 |
8 |
42 |
51 |
| SiC % |
/ |
89 |
/ |
/ |
| Max. water content |
/ |
/ |
14 |
5 |
| Bulk density g/cm3 |
2.50 |
2.65 |
2.00 |
2.40 |
| Apparent porosity % |
/ |
13.0 |
/ |
8.0 |
| Cold crushing strength Mpa |
92.0 |
150.0 |
50.0 |
60.0 |
| Modulus of rupture Mpa |
/ |
25.0 |
9.0 |
14.0 |
| Max. working temperature ℃ |
1600 |
/ |
1500 |
1500 |
The outer lining of fluidized bed garbage incinerator is casted by 250mm thick high temperature resistant & abrasion resistant concrete, middle layer(insulating lining) is casted by 150mm thick lightweight heat resistant concrete, working lining is casted by 100mm thick phosphate bauxite concrete(bauxite clinker: low calcium aluminate cement: aluminum hydroxide fine powder: aluminum phosphate solution=100:2.5:2.5:20~24), or the working lining is lined by lightweight insulating bricks and first grade
high alumina bricks.
Garbage Incinerator Water Wall Refractory Physiochemical Index
| Item |
Silicon carbide castable |
Low cement self flow castable |
Silicon carbide brick |
| SiC % |
85 |
83 |
87 |
| Al2O3 % |
3 |
9 |
2 |
| Apparent porosity % |
18.0 |
14.5 |
11.0 |
| Bulk density g/cm3 |
2.7 |
2.45 |
2.7 |
| Modulus of rupture Mpa |
5 |
7 |
20 |
| Thermal conductivity W/(m·K) |
10.5 |
6.9 |
13.4 |
Fluidized bed incinerator has wide adaption to garbage with different calorific value, it can also process rural garbage and high calorific value industrial plastic garbage. But fluidized bed garbage incinerator has high requirement on garbage granularity, the operation and maintenance cost is very high, garbage pretreatment equipment investment is also high, which constrain the application of fluidized bed incineration technique.
