Refractory plastics have a variety of materials: clay, high alumina, corundum, silica, magnesium, chromium, zircon and silicon carbide. It is made of graded refractory aggregates, powders, binders, water or other liquids through full mixing. It can be divided into water glass, phosphate, sulfate and organic binder refractory plastics according to the types of binders.
Before construction, the construction department should clean up the debris in and around the furnace and transport the air compressor, construction equipment and scaffolding to the site. The air compressor is connected to the power supply and the test run is normal. The following table shows the types and main technical indicators of tamping machines and air picks. It can be directly used in tamping material construction. When tamping plastic, the hammer head needs rubber pad. Construction tools include dressing knife, slotting knife, air permeable brazing, steel wire brush, film pressing and wood wedge for fixing anchoring bricks in the same shape as anchoring bricks.
The refractory plastic billet should be stored in a cool warehouse. Before construction, the plasticity of the billet should be checked to meet the requirements before construction. The simple judgment method is that the plastic can be grasped by hand, and it is easy to pinch into groups without dispersing, so it can be used.
When the furnace wall is not high, its insulation layer can be built at one time, otherwise it should be layered in different sections. The construction of the insulation layer on the top of the furnace can be done by ramming the plastic lining on the top of the furnace, or by ramming the plastic lining on the top of the furnace, centrally laying the insulation layer or pouring with insulating castables. The general principle is that when laying or watering the heat insulation layer on the top of the furnace, it is absolutely not allowed to bury the metal connector of the hanging brick in it, that is, to expose the piece in the air, so as to heat dissipation and improve its life.
In addition, the refractory plastics are constructed by tamping and compacting method. Before the construction, the plastics are laid on the required parts. The blank laying should be close to the wrong joint. After tamping, the blank joint should be tampered. Then the whole area should be tampered three times with pneumatic hammer or hand hammer to ensure the material density. Correct anchoring factor is very important for supporting sheet plastics. Using rigid anchoring pin tip, the distance between top and bottom of anchoring pin tip is about 150 mm ~ 250 mm. The thickness of material can be determined according to the design requirements of different furnace types.
1. After locating the damaged part, the edge of the tool is repaired into a right-angle sag of not less than 20 mm, that is, a repairing thickness of not less than 20 mm. After repairing, the plastics can be smoothed excessively in the original refractory, and the trapezoidal connection can not appear.
2. Clean up the repaired parts. If the original refractories have unstable size particles, they must be removed. There must be no floating dust to ensure that the repaired surface has a solid and clean working surface.
3. Slice the plastic with very clean cutter, stick the fresh side to the repairing part, and then tamp it with pneumatic hammer or hand hammer. The blank should be laid close to the wrong seam. After tamping, the blank should be tampered with the wrong seam, so that no seam can appear. After all the repairing surface is pasted, tamp it with hammer again and again until the blank is still on the surface. It's damp now. Pay attention to the edge when tamping, not tamping the original refractory, and finally make the whole repair surface into a smooth plane.
4. Repair of local depression in water wall. Weld heat-resistant steel nail tip on connecting plate or water-cooled pipe body at depression of water wall. The length of nail tip is 20mm~30mm, and the interval is 30mm~40mm. Then compact the billet.