Materials for furnace devices

For the device furnaces used all sorts of materials with different physical properties, devices and accessories. Of the physical properties of the most important fire-resistance and thermal expansion, as some of the stoves in their furnaces are subjected to different temperature effects to the same material depending on the heat expands unequally. In the furnace work is particularly true for products made of metal, which leads to the destruction or breakdown of the furnace brickwork. For example, a steel rod 1000 mm long by heating it from room temperature to 100 ° C is extended by 1.2 mm. Under the stronger heating it expands even more. Taking into account the thermal expansion of the metal, its very limited use in the oven works, especially for vnutripechnoy masonry. In the furnace works can not use combustible materials or materials capable of melting at high temperatures, as well as material deformed by heating. The basic materials of stone materials. These include sandstone, limestone and quarry stone. Basically they are used for masonry hearth. Sandstone - a solid rock composed of sand grains, bonded together with clay or lime. Limestone - durable material, is slightly inferior in strength of sandstone. Quarry stone - the common name of rock, including those listed above. Quarry stone is divided into a ragged, uncertain shape, rounded cobblestones, smooth; postelisty - flat stones, rubble slab - flat stone slabs. To get an even better reason to use postelistye stones or rubble slab. They are more densely packed and safely grapple with the solution. Brick - artificial stone, obtained from well-selected clay, followed by plastic or dry pressing, drying and roasting. It serves as a basic material for masonry stoves. Manufactures several varieties of brick. Brick Clay Common, or red, after drying, fired at temperatures from 800 to 1000 ° C. In the firing process, individual clay particles melt and bind the whole mass of bricks in a single unit, giving it the necessary strength. Clay during firing varies in color and becomes red or brick red. Not all places kiln temperature during firing is the same. Where it exceeds 1000 ° C, the clay melts strongly, resulting in a dark and partially covered by the glassy film. As it turns out bleach, brick, or iron ore. He is very strong, bad tunic, weakly associated with the solution and is not suitable for baking masonry. It is used for the installation of foundations for the furnace and the building. If the temperature does not exceed the permissible limits, it works out fine annealed, or red brick appropriate porosity. When prostukivanii a brick produces pure metallic sound, well split, amenable tesaniyu, the fall did not crumble and break into large pieces. In places with inadequate temperature turns red, or nedozhzhenny, Brick (nedozheg) with a pale pink color. When he publishes prostukivanii muffled sound, falling, falling apart into small pieces, very porous and absorbs water. In the furnace works its use is limited, irresponsible in the field. Given the above, for furnace brick works recommended to take. Bricks are made in size 250 * 120 * 65 mm, with some tolerances, which depend on the molding. In the plastic extrusion can be Good quality plus or minus tolerances of up to 4 mm in length and up to 3 mm in width and thickness, with dry pressing - 3 and 2 mm respectively. Weight of bricks equals 3,5 - 3,8 kg. Mark on the compression - at least 300, 250, 200, 150, 125, 100 and 75 Kg/cm2. Brick, which in due course awarded the State Quality Mark has a brand no less than 125. Brick should be a cuboid, with straight edges and corners, with sharp edges and flat front surface, without through cracks, etc. Bulk weight of an ordinary brick - about 1800 kg/m3. In a cubic meter of solid masonry is laid about 380 bricks. If the brick kilns during disassembly did not lose their shape and strength, it is possible to use again, but with the mandatory clearance from the solution and sorting. Depending on the state, it is used for laying the foundations, pipe, and then plaster the past. Brick, obtained from dismantling the walls of buildings, stacked on the mortar, masonry stoves themselves unfit. It is used for laying the foundations and upper parts of the stack (above the roof). Not allowed to apply for masonry stoves and chimneys silicate, hollow and perforated bricks. In furnaces furnace flue and the first channel, where the temperature is very high, especially the burning of coal, common (red) brick oven quickly collapses and has to repair or move. Therefore, in such places should be used refractory bricks made from clay of high fire resistance and durability. They are referred to the area in which they are made. The greatest strength and improved fire resistance is white in color, smooth and Gzhel Borovichsky brick. It can withstand temperatures from 900 to 1000 ° C. It is used for lining the firebox stoves, which burn wood and peat. Refractory fireclay bricks can withstand temperatures up to 1200 ° C (class A). They veneer, or footer, the firebox stoves designed to burn coal. Produce it by mixing chamotte powder in baked and milled refractory clay. The dimensions of this brick 250 * 123 * 65 230 * 113 * 65 mm. Refractory and refractory bricks in all the figures in the shaded cell. Hearth brick is mainly used for lining the hearth in the bakery and Russian stoves. To get a smoother surface and reduce the number of seams, it manufactures in size 225 * 225 * 70 mm from the ordinary or fire clay. Clay Common (or red) represents the remnants of weathered rocks, consisting of tiny particles in the form of flakes. Usually it occurs in the form of soil in a dry or slightly damp mixed with sand, lime, mica, etc. Depending on the amount of impurities clay is divided into a fat, mean and lean. In the loam contained 2-3% of sand in the middle - about 15%, and lean - about 30%. Clay can absorb large amounts of water while increasing in volume (swell), forming a dough. After drying, the volume of its reduced and the surface cracks. When heated, the clay from 400 to 700 ° C, it first begins to release water. After the full value of water clay is porous, and then gradually melts or sinters. During freezing, ranging from 0 ° C, it swells and increases in volume. Dough clay is plastic, easily accepts and retains bodied. Plasticity of the clay depends on the size of the particles of clay substance, impurities, and other causes. Shrinkage of high plasticity clay - 8.6%, thin - less than 6%. Clean impurities from the clay used for the manufacture of refractory products. Ordinary (or red) clay is used as a solution for masonry stove arrays - furnace of an ordinary red brick. Gzhel and other refractory clay is used for the masonry firebox and the first (flame) channels, carried out Gzhel or refractory bricks. Of the refractory clay spread of the fire wall and a first uplink in furnaces operating on coal, coal or oil. Sand. Sand used as filler in clay mortar for masonry stoves. It should be clean and have no impurities sludge, lime, crop residues and other contaminants to substances. The best sand is mountainous with rough surfaces. River sand is less suitable because its grains are round, smooth shape and it is less adhesion to the clay. Contaminated sand washed. Sand is added to the common and refractory clay, and particularly in fat. The fatter the clay, the more sand is added, and vice versa. In refractory clay instead of sand added chamotte. Sand added to the solution should be small, with grain size less than 1 mm, which allows you to get the thin seams, thereby increasing the strength of masonry stoves. Water. Best water for masonry stoves is rain or river. The water should not be admixtures of salts, acids and alkalis. Hard water in the furnace actually undesirable. It is forbidden to use water from puddles. Building lime. Its manufactured by burning limestone in a special rotary or shaft kilns. It is calcium, magnesia and dolomite of the first, second and third grades. After firing, the obtained lump of lime - kipelka. Divided into bystrogasyaschuyusya - no more than 8 minutes, srednegasyaschuyusya - no more than 25 minutes and medlennogasyaschuyusya - more than 25 minutes extinguishing. Ably quenched from a high-quality lime and lime putty in large numbers, and vice versa. Store lump lime is necessary in dry sheds (places) on the plank floor. In damp places, it is gradually extinguished, becoming pushenku - a fine powder. It is best known kipelku repay the dough, which under appropriate conditions can be stored for decades, improving at the same time its astringent properties. Lime is used for the preparation of solutions that are used for laying foundations for the furnace and headroom pipes located above the roof. At this solution lay out the root tube height to two storeys. Cements - binders of high durability. Made five brands of cement with a tensile strength: 300, 400, 500, 550 and 600 kg/cm2. There are Portland cement and Portland cement with mineral additives, slag cement and portland cement and slag cement, quick. They quickly grasped as compared with clay and lime. Start of setting - no earlier than 45 minutes after mixing the dry mixture with water, the end of the setting - not later than 12 hours of them prepare cement mortars or added to the clay and mortar to give strength. Cements should be stored in dry places, preferably polyethylene, tightly tied bags. From contact with air cements are gradually reducing their quality. Cement mortars used in the same cases as lime. Substances binders, containing lime, hydraulic. Manufactures four brands with a tensile strength: 50, 100, 150 and 200 kg/cm2. Start of setting should occur no earlier than 25 minutes and final set - not later than 24 hours after the onset of solidification. Used for the same purposes as discussed above, lime and cement. Concrete - a very durable synthetic material. To obtain the concrete mass is prepared dry mixture of correct selection of cement, fine and coarse aggregates, and then closes it with water. Placed him within the hour. Possible to prepare concrete of different strength, but not higher grade of cement. Given the strength of concrete are selected specifically for laboratories and data is transmitted to the factories or construction sites. If the concrete pour a steel rebar or steel mesh, you get concrete. Are reinforced concrete on the calculation. Heat-resistant concrete can withstand temperatures up to 1200 ° C. Sometimes it is different compositions and materials for its preparation measure off in accordance with the recipe parts by weight. For blocks of concrete firebox prepared from Portland cement not less than 400 (1 part), rubble of refractory bricks (2 parts), sand from the refractory bricks (2 parts), finely dustable supplements chamotte (0.33 parts). Plaster - white powder, hardens quickly when mixed with water (grasped) and is used as an additive to mortar to accelerate their grasp. Is also part of the solution, used for plastering furnaces.