When constructing circulating fluidized bed boiler lining refractory materials, the following points need to be noted to ensure the construction quality and safe operation of the boiler:
1. Material management
Material classification and storage:
Refractory materials should be classified and stacked neatly, with obvious signs to avoid confusion.
The materials should be stored in a moisture-proof and rain-proof place, the bottom should be raised by 20~30cm, and the top and surroundings should be covered with waterproof cloth.
Material inspection:
After the refractory materials enter the site, the materials must be checked for documents in time to confirm that all indicators meet the technical requirements.
Check the production time and validity period of the product. Materials that have exceeded the validity period are prohibited from use.
If necessary, conduct a secondary re-inspection to ensure that the material quality is qualified.
2. Preparation before construction
Drawings and design:
Be familiar with the construction drawings and design requirements to ensure that the construction meets the design standards.
Environmental control:
The water used for mixing must be clean tap water. It is strictly forbidden to use alkaline water and water containing organic suspended matter.
During winter construction, winter construction measures such as closure, windbreak, heating and insulation should be taken to ensure that the temperature of the lining after masonry is above 5°C.
3. Construction process control
Installation of heat-resistant steel bars and grab nails:
Heat-resistant steel bars and grab nails should be installed and welded according to design requirements to ensure firmness and reliability.
Before welding, the welding joints need to be polished to remove rust and paint.
Formwork configuration and installation:
The surface of the wooden formwork should be clean and smooth, without sticking or porosity.
The formwork splicing should be tight and the support should be firm to ensure the shape and quality of the castable.
Mixing and pouring:
The mixing equipment should use an appropriate stirrer to ensure good mixing of the adhesive.
The mixing time should be sufficient, generally 4 to 6 minutes, depending on the material requirements.
Pouring should be carried out in layers, and each layer should be vibrated and compacted to ensure that there are no cavities and bubbles.
Expansion joint treatment:
Leave expansion joints according to the design requirements of the drawings, and the width deviation should be controlled within ±3mm.
The expansion joint should be clean and free of debris, and can be filled with fillers such as ceramic fiber paper.
Special parts treatment:
For secondary air nozzles, coal nozzles and other parts, a 2mm thick layer of asphalt should be applied before pouring wear-resistant castables.
For the hood and air inlet pipe on the air distribution plate, protective measures should be taken to prevent the castables from clogging.
IV. Post-construction treatment
Mold removal and maintenance:
The formwork should be removed in time after the castable hardens, generally after 12 hours.
A hammer sound test should be carried out before demolding to confirm that the refractory material has been effectively hardened.
After removing the formwork, necessary maintenance is required to ensure that the castable reaches the design strength.
Quality inspection:
Quality inspection of the completed lining, including appearance inspection, size inspection and performance inspection, etc.
If problems are found, they should be handled in time and re-constructed.
V. Safety precautions
Personal protection:
Construction workers need to wear personal protective equipment, such as safety helmets, protective glasses, dust masks, etc.
Construction environment:
Ensure that the construction environment is well ventilated to avoid the accumulation of harmful gases.
Smoking and using open flames are strictly prohibited at the construction site.
Equipment operation:
Strictly abide by the equipment operation procedures to ensure the safe operation of the equipment.
In short, when constructing the lining refractory materials of the circulating fluidized bed boiler, attention should be paid to material management, pre-construction preparation, construction process control, post-construction processing, and safety precautions to ensure the construction quality and the safe operation of the boiler.
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