Heat treatment furnace is a metal workpiece for a variety of metal heating process industrial furnace collectively. The temperature is generally lower than the furnace. Heat treatment furnace can be used in a variety of furnace furnace, but the temperature of the furnace and the furnace more stringent. Most of the heat treatment furnace gas fuel heating, in order to accurately control the furnace temperature, and some heat treatment furnace with electric heating.
Heat treatment furnace often use a lot of furnace. Heat treatment furnace application temperature is low, the operating conditions are generally good with heat insulation refractory bricks or clay refractory brick masonry individual parts with high alumina refractory bricks, cordierite brick, silicon carbide brick and corundum brick can also be used for non-structured refractory material lining.
Heat treatment furnace is composed of furnace wall, roof and bottom three parts. Generally with refractory bricks, refractory castables and refractory fiber cotton and other materials as lining, due to furnace type, refractory varieties and heat treatment process conditions of its different service life is not the same.
1, refractory brick furnace body. The use of insulated refractory bricks and refractory masonry lining for a variety of heat treatment furnace. The thickness of the furnace wall is generally about 460 mm. Insulation layer thickness of 70 ~ 230mm with a bulk density of 0.8g / cm3 diatomite refractory bricks, clay or high-alumina insulation brick, floating beads or calcium silicate insulation board masonry. Working layer thickness of 230 ~ 348mm. Chain furnace and muffle furnace and other high-temperature annealing furnace working layer with clay refractory masonry continuous horizontal furnace, tower furnace and hood furnace furnace working layer available bulk density of 0.8 ~ 1.0g / cm3 clay Or high-aluminum insulation brick and floating beads brick masonry roll furnace on the upper side of the masonry roll masonry masonry to facilitate the replacement of the furnace roll, tower furnace and pit furnace furnace wall to prevent the whole Pour out every 2m high parts should be installed metal joists or tiles and connected with the furnace shell. The holes on the wall are surrounded by clay refractory masonry. The use of non-hood or muffle of the bright treatment of vertical furnace and tower furnace and other equipment when dealing with stainless steel and other senior metal materials need to pass high purity dry hydrogen or nitrogen and hydrogen and other protective gases so the furnace must be high purity Refractory material that is the lower part of the furnace wall and some special-shaped plate and the tube should be sintered or fused corundum material to build the remaining furnace wall with alumina hollow ball insulation brick masonry mud must also be used with the masonry. Such materials in the heating process does not precipitate any harmful gases and can resist the destruction of hydrogen so the furnace application life is longer.
The roof is divided into hanging flat top, fixed or removable vault and so on. The top of the furnace is a mobile roof. The thickness of the working and insulation layers of the furnace tops are 230 mm and 70 to 230 mm, respectively, and the refractory material used is basically the same as the furnace wall.
Heat treatment furnace bottom in addition to the chain furnace and some muffle furnace are load-bearing. The thickness of the working layer and the insulating layer are generally 230 mm and 70 to 230 mm, respectively. The former with clay refractory masonry the latter with clay or high-alumina insulation brick, floating beads or diatomite brick masonry use. Heat treatment furnace brick furnace body under proper operating conditions for the service life of 3 years to reach more than 4 years. During this period vulnerable parts of the lining to go through several minor repairs.
2, refractory castable furnace. Pouring with a refractory castable or working with a prefabricated block of a heat treatment furnace. Chamber furnaces and car-bottom furnaces Furnaces for high-alumina cement refractory castables Prefabricated blocks are not only fast construction and less heat dissipation in the furnace for up to 3 years When anchoring bricks and hanging bricks are used, Cement and clay refractory castable or high-strength light refractory castable on-site watering when the furnace body is good, less heat, thermal shock resistance and therefore its application life is generally 2 years.
3, refractory fiber furnace. With the fire-resistant fiber blanket, felt, plate, brick and its combination of pieces of products such as paving heat treatment furnace furnace or paste its working layer can save fuel economic effect is more significant but the application life to be improved.
Paste method is to use high-temperature adhesive to the fiber strip on the surface of the original lining work layer can be directly contact with the flames. First, the surface of the lining completely clean the brushing high-temperature adhesive and then the refractory fiber felt blanket cut into small strips attached to the surface and pressed its thickness is generally 30 ~ 60mm.
Layer method is to use fire-resistant fiber carpet directly to do lining. First in the furnace shell welding metal screw and the thickness of 480mm mineral wool or insulation board. After the refractory fiber mat or plate hanging on the screw and with a gasket and screw cap to form a working layer thickness is generally 80 ~ 120mm. When the furnace operating temperature is high when the screw should be added to the protective cap or with ceramic fasteners. Such as in the refractory fiber furnace surface coated with a thin layer of high temperature coating can protect the lining can also improve the furnace thermal efficiency. The working temperature of the plate-type furnace and the trolley type annealing furnace is 850 ~ 1000oC. The service life of the floor is over 3 years.
Stacking method is a good construction method for refractory fiber furnace. The refractory fiber felt is cut or folded into a length of 800 to 1000 mm in width at a distance of 80 to 100 mm between the furnace and the metal anchor rod parallel to the furnace shell. The binder forms a refractory fiber block over the upper layer of the anchor rod to form a furnace body. Its unique place is the metal anchor away from the face is conducive to the refractory fiber furnace body to adapt to higher temperature operation and extend the life but the fiber consumption of a large cost of building a high furnace.
Masonry method is made of refractory fibers made of fibrous bricks or Z-shaped folded fiber blocks after the masonry furnace. Fiber bricks generally used high-temperature binder wet fiber blocks because of their own with a fixed metal pieces of masonry when the metal out with a rivet gun can be fixed on the shell can be. The furnace body constructed by this method can be significantly improved in its life at higher temperatures.