1) Control the quality of water distribution
Before the construction of CFB boiler castables, it is necessary to check the quality of construction water to ensure that the water quality can meet the CFB boiler castable construction standards. In addition, it is necessary to do a good job of water distribution. Specifically, special construction personnel need to use quantitative containers to complete the water distribution operation to control the amount of water used. If more water is added, the solidification time will be prolonged and the mechanical strength of the castable will decrease; if water is added Less, it will increase the difficulty of vibrating the castable, lack of fluidity, resulting in uneven texture of the castable and honeycomb surface phenomenon. The specific amount of water added should be determined by the temperature and distance control method at the construction site of the CFB boiler castable.
2) Do a good job in template production and inspection
Before the template is made, it is necessary to do a good job of inspection. Specifically, it is necessary to check whether the support, pins, hooks and other structures of the template meet the standards of the construction drawings. At the same time, check whether the template release agent meets the construction standards, and increase the number of pins in the corners of the template , The nozzle inside the furnace needs to be connected with pins through stainless steel ribs to improve the strength of the castable at the corners.
3) Control the quality of template production
The quality of the formwork is directly related to the quality of the CFB boiler castables. For this reason, it is necessary to do a good job in the quality control of the formwork production. The key is to control the firmness of the formwork, and at the same time, it is necessary to ensure the accuracy of the formwork size. The firmness of the formwork is high in order to prevent mold running. If there is a runaway phenomenon during the construction process, it is necessary to immediately stop the construction and remove the formwork, and re-make the formwork at the same time. This is because the running of the form will cause uneven casting materials. The template needs to be lofted and assembled in accordance with the construction requirements, while ensuring the tightness of the interface, and the surface of the template needs to be painted with a release agent.
4) Control the quality of mixing and vibrating
If you want to control the quality of mixing and vibrating, you need to pay attention to the mixing amount of each castable. 6~10 bags (25kg/bag) are appropriate. At the same time, it needs to be evenly mixed in the mixer before adding water, so as to ensure the quality of the castable. The degree of uniformity, if you need to add steel fibers during the mixing process, you need to pay attention to not adding them in agglomerates, and spread them evenly. After mixing, the storage time of the castable should not exceed 40 minutes. It is best to immediately introduce the castable into the template and vibrate in time. The vibrating operation is based on the appearance of bubbles in the castable. When removing the vibrator, pay attention to the slow movement. , It is advisable to tilt 45° to avoid leaving holes. At the same time, it is also necessary to ensure the compactness of vibrating, and there should be no dead corners that have not been vibrated. For corners in the template that cannot be shaken, a hammer can be used to slightly shake the template along the erection direction of the template. The pouring work needs to be completed at one time as much as possible, and the pouring material cannot be repeatedly applied. If the pouring surface is uneven, the pouring surface cannot be smoothed by the second construction method.
5) Reserve expansion joints
The expansion coefficient of the castable is different from that of the steel. For this reason, it is necessary to prepare expansion joints during the construction process to avoid cracks in the castable. At present, there are mainly the following ways to reserve expansion joints: paint bitumen paint on pins and metal surfaces, and control the paint thickness above 1mm; use the block interval method to complete the casting of the castable, and use 3mm thick plywood As an expansion joint; use ceramic fiber paper with a thickness of 2mm to wrap around the surface of metal wall-through fittings, hoods, and instrument pipe fittings as expansion joints; cut out expansion joints that are half the thickness of the construction material during plastic construction, preferably in a “Z” shape “Seal structure.
6) Reserve the measuring point hole
A large number of pressure measurement points and temperature measurement points are distributed in the furnace, circulation circuit, and slag discharge equipment of the CFB boiler. These measurement points are responsible for checking the installation data and can also reflect the operation of the CFB boiler. The operator can combine the pressure measurement Point and temperature measurement point to monitor the situation to adjust the boiler combustion status. It can be seen from this that it is necessary to do a good job of preserving measuring point holes, prohibiting the deviation in elevation and angle of the measuring point holes, especially the pressure measuring points in the lower layer of the boiler, and also need to avoid the difficulty of component installation caused by the angle deviation of the measuring points. Increase the problem.
