Floats the bead

　　Floats the bead introduce:

　　1、Floats the bead formation mechanism: The coal-burning power plant many grinds to the coal the powdered coal, gushes in the electricity generation boiler chamber, lets its aerosol burning.Coal combustible constituent (coal and organic matter) majority of burning, but the clayey combustible constituent (silicon, aluminum, iron, magnesium and so on) start under the chamber 1300 degrees centigrade high temperatures to fuse, form the quartz glass and the mullite porous symbiont, in its fills the gas.When the furnace temperature achieved when 1400 degrees centigrade, the molten mass pellet surface tension can cause the surface energy to fall the minimum value, the edges and corners gets rid of the surface energy to contract, the fusing pellet can drift the trundle to form the spheroid.By now, in porous body gas like CO, CO 2, N2, H 2 and so on are wrapped in the ball. When the furnace temperature continues elevates, the bulb in vivo expansion of gas, causes the spheroid to increase, the outer covering changes thin, forms the spatial spheroid. Middle the spatial spheroid leaves the chamber, after cools rapidly, turned the hard outer covering glass micro bead.These glass micro bead, because wall thickness and the weight are different, may divide into two kinds. One kind is in the thin wall the spatial spheroid (wall thickness for diameter 1/10), because may float aquatic, is called “floats the bead”. Another kind is in wall thickness the spatial spheroid (wall thickness for diameter 1/3) and the solid spheroid, because of heavy sinks in under water, therefore the city “sinks the bead: Iron content high named “magnetism bead”.Floats the bead in the pulverized coal ash the content really micro, is only generally 0.2-0.5%, minority may reach 1%: Sinks the bead quantity to be very big, approximately for pulverized coal ash 30-70%. Floats the bead output and the quality, plants, factors and so on coal degree of fineness, boiler load, burning condition with the coal concerns. Between various power plants, between a power plant different boiler, boiler different time, has the enormous difference.General calorific capacity high, including sulfur quantity low bituminous coal, floats the bead quantity to be many: The anthracite floats the bead to be few, the lignite floats the bead to be extremely few even not floats the bead. In the chamber the temperature is lower than 1400 degrees centigrade, looks young for one's age Cheng Piaozhu very much: 1400-1500 degree centigrade, forms floats the bead to be many, above 1500 degrees centigrade, forms floats the bead to be able to explode the fragmentation. Therefore furnace temperature Gao Huo low has been able to affect floats the bead formation.

　　2、Floats the bead outstanding performance and the use

　　High refractoriness. Floats the bead main chemical composition for the silicon, the aluminum oxide compound, in which silicon dioxide is approximately 50-65%, the trioxide two aluminum are approximately 25-35%.

　　Because of silicon dioxide melting point reaching as high as 1725 degrees centigrade, trioxide two aluminum melting points for 2050 degrees centigrade, for high fireproof material. Therefore, floats the bead to have the extremely high refractoriness, amounts to 1600-1700 degree centigrade generally, causes it to become the outstanding high performance fire-proof material.

　　Nature light, heat preservation heat insulation. Floats the bead wall thinly spatial, in the cavity is half vacuum, only then the trace gas (N2, H2 and CO2 and so on), the heat conduction is extremely slow extremely micro. Not only therefore floats the bead the nature lightly (the bulk specific gravity 250-450 kilogram/m3), moreover heat preservation heat insulation outstanding (thermal conductivity normal temperature 0.08-0.1), this gave full play for it in the light quality heat preservation thermal insulation material domain has laid the foundation.

　　The granularity is thin, is bigger than the surface area. Floats the granularity which the bead forms naturally is 1-250 micron. Compared to surface area 300-360g/cm2, is similar with the cement. Therefore, floats the bead not to need the powder to rub, may use directly. Degree of fineness may satisfy each product the need, other light quality thermal insulation material general granularity very is all big (for example pearlite and so on), if the white powder on ripe apples or other fruit rubs can increase the capacity large scale, causes heat-insulated to reduce greatly. In this aspect, floats the bead to have the superiority.

　　The electric insulation is outstanding. After chooses the demagnetization bead to float the bead, is the performance outstanding insulation material, not electric conduction. The common insulator resistance reduces along with the temperature ascension, floats the bead then opposite, increases along with the temperature ascension resistance. This merit is other insulation material all does not have. Therefore, it may manufacture under the hot conditions the insulation product.