How to improve refractory castable/refractory lining service life of CFB boilers
It’s quite important to know well the working conditions inside the CFB Boilers. The material density inside the CFB is dozens of times and even hundreds of times to coal boilers. Considering the high density granule and high speed wind running, the smoke flow rate is heavier, and these conditions cause refractory materials linings easily being roded and wearing down.
So it’s the key point to pay more attention on the refractory material abrasion resistance during refractory castable choosing, application and installation.
The installation of refractory castable is affected by various of factors. We talked about several key points during installation:
- Refractory castable option and storage
Refractory materials for CFB is with various kinds for different application areas. Please choose the right refractory castable not the cheaper one. And storage in dry environment to avoid humidity. Keep material valid in shelf life.
- Refractory material quality inspection
Check the material specification as per technical data, and arrange professional furnace wall technician to make castable test block. After checking material qualified, put into practice.
- Heat resistant steel/ Metal anchors installation
Check the anchors material quality. In order to make sure all anchors orderly in a row, drawing with ink lines as per design distance between each welding points. Before welding the anchors to metal shell, to polish, clean and remove rusts or painting, to make sure the welding fastness.
- Expansion joint installation
keep suitable expansion joint, to make sure available space for castable expansion at high temperature, and then to avoid the refractory castable cracks.
- Wooden frame installation
Casting result is depended on the wooden frames setting and installing. Because of CFB widely casting area and irregular shape, it’s a huge and difficult work to make and install wooden frames. It needs support of professional carpenters.
- Mixing and stiring
Refractory castable mixing, pouring and vibrating is a continuous process. It’s important to control the installation time.
- Demoulding and baking
After castable setting to be solid, to remove the wooden frames. At normal temperature, it can be removed after 12hours. Please test by hammering the lining surface with a crisp sound. And then baking as per the baking curve which is provided by related manufacturer.