Heat treatment furnace is a general designation of metal workpiece for various metal heating process industrial furnaces. The temperature is generally lower than the heating furnace. Heat treatment furnace can be used in a variety of furnace, but the control furnace mild furnace atmosphere is more stringent. Heat treatment furnaces mostly use gas fuel to heat, in order to control the furnace temperature accurately, some heat treatment furnace electric heating.
Heat treatment furnaces often use a lot of furnace. Heat treatment furnace application temperature is low, the operating conditions of the general use of insulating refractory brick or clay refractory brick masonry individual parts of the use of high alumina refractory bricks, cordierite bricks, silicon carbide bricks and corundum bricks, etc. can also be used for lining refractory materials.
Heat treatment furnace is composed of three parts, furnace wall, top and bottom of furnace. Generally, refractory bricks, refractory castable and refractory fiber cotton are used as lining, because of the different service life of the furnace, refractory materials and heat treatment conditions.
1, Refractory brick masonry furnace body. The lining of insulating refractory bricks and refractory brick is suitable for various heat treatment furnaces. The thickness of the furnace wall is generally about 460mm. The thickness of the insulating layer is 70~230mm with a volumetric density of 0.8g/cm3 diatomite Refractory bricks, clay or high alumina insulation bricks, floating bead bricks or calcium silicate insulation Board masonry. The thickness of the working layer is 230~348mm. Chain Furnace and muffle high-temperature annealing furnace working layer with clay refractory brick masonry continuous horizontal furnace, the working layer of the furnace such as the tower type stove and the cover furnace can be 0.8~1.0g/cm3 clay or high alumina insulation brick and floating bead brick masonry roller hearth furnace roll on the side of the masonry using roll-neck brick to facilitate the replacement of the Furnace roll, The furnace wall of the tower furnace and the well type furnace is higher to prevent all pouring out of the 2m high parts should be installed metal joists or tensile bricks and connected with the furnace shell. The holes around the furnace wall are all made of clay refractory bricks. The use of light treatment without hood or a horse bushing vertical furnace and tower furnace and other equipment when processing stainless steel and other high-grade metal materials need to pass into high-purity dry hydrogen or nitrogen one hydrogen and other protective gases so the furnace must be used high-purity refractory materials that are several layers of brick in the lower part of the furnace wall and some special shaped plates and tubes shall be sintered or fused corundum materials for the construction of the remaining furnace walls the slurry used in the masonry of alumina hollow ball insulated bricks must also be Adaptive。 This kind of material does not precipitate any harmful gas during the heating process and can resist the destruction of hydrogen, so the furnace has a long life.
The top is divided into hanging flat roof, stationary type or removable vault, etc. The roof of a well furnace is a movable furnace cover. The thickness of the top working layer and the insulating layer are the same as that of the furnace wall and the refractories used for 230mm and 70~230mm respectively.
The furnace bottom of the heat treatment furnace is load-bearing except the catenary furnace and some muffle. The thickness of the working layer and the insulating layer are generally 230mm and 70~230mm respectively. The former uses clay refractory bricks to masonry the latter, using clay or high alumina insulation bricks, floating bead bricks or diatomite bricks. The brick-masonry furnace of heat treatment furnace has a service life of 3 years and more than 4 years in proper operation condition. During this period the easily damaged parts of the lining need to undergo several minor repairs.
2, Refractory castable material furnace body. The working layer liner of the heat treatment furnace, which is poured with refractory castable or used in prefabricated blocks. The precast block of high alumina cement refractory castable for furnace body of chamber furnace and bottom furnace is not only the construction speed and the heat dissipation of the furnace body are less than 3 years when the use of anchoring bricks and hanging bricks, with high alumina cement and clay refractory castable or high strength lightweight refractory castable, the furnace body has good integrity, less heat dissipation, Its application life is generally 2 years because of its good thermal shock resistance.
3, Refractory fiber furnace body. The use of refractory fiber blanket, felt, plate, brick and its combination of products such as heat treatment furnace body or paste their working layer can save fuel economic effect is more significant but the application life needs to be improved.
The pasting method is to use the high temperature binder to attach the fiber strips to the surface of the original lining working layer to contact the flame directly. Thoroughly clean the surface of the lining of the furnace to brush the high-temperature binder and then cut the refractory fiber felt blanket into a small strip of vertical paste on its surface and pressure on its thickness is generally 30~60mm.