Circulating fluidized bed boiler (CFB boiler) has become a development direction of clean combustion technology due to its advantages of wide range of combustion adaptation, cheap desulfurization, low pollutant emission and high combustion rate.
However, in the actual operation process, the wear of CFB boiler has become a prominent problem that directly affects its economy and safety, in addition, the boiler furnace, ignition air duct, refeeder and other parts of the lining refractory falling off, but also seriously affect the normal operation of the boiler.
1 Construction Procedure
The site construction of wear-resistant refractory lining should be considered according to its lifting capacity, site size, schedule, climate and other conditions, and there can be no unified model. However, it is always possible to prefabricate the lining before the boiler assembly to reduce the amount of high-altitude work after the equipment is in place.
For example, the boiler's ignition air duct, steering flue, cyclone separator, refeeder, slag drainer, etc., the group handles the interface part after installation. For the convection tube bundle on the heating surface, due to the need to do the hydraulic test, it is not allowed to cover the pipe surface in advance, sometimes in order to catch up with the construction period, you can obtain the consent of the boiler inspection department, before doing the air tightness test, the part that needs to be lined with the anti-wear layer on the combined surface for kerosene leakage inspection, and confirm the qualified can be the first lining construction operation.
The lining construction on the bed cloth air plate is a more troublesome part, because there are many cowls, the size of the inner lining surface should be accurate, and the inner lining should be prevented from blocking the tuyole, so the cowl should be wrapped with tape before construction, and the lining thickness should be marked, and then carefully fill the material layer, and ramming with small tools.
2. Selection of materials
1) Castable
(1) The price of castable is cheaper, the construction quality is easier to control, and it is suitable for large-scale construction, but its wear resistance and repair conditions are not as good as ramming materials.
(2) The castable ramming construction should be as far as possible on the ground, so as to save the template, followed by the side, if it is a cylinder, it should be rolled. On-site prefabrication operations should consider the rotation of the components, which is restricted by the weight of the construction equipment, if only partial prefabrication, it should be left behind for later operations.
(3) The water-cement ratio of castable is crucial to the quality and should be strictly controlled.