Car type annealing furnace fuel also follow resources development and the progress of fuel conversion technology, and by selecting coal, coke, coal and other solid fuel gradually convert producer gas, city gas, natural gas, gas and liquid fuels such as diesel oil, fuel oil, and developed and adapted to the fuel used in a variety of fire equipment.
The structure, heating technology, temperature control and atmosphere of the annealing furnace will directly affect the product quality after processing. In the casting furnace, improving the heating temperature of the metal can reduce the deformation resistance, but too high temperature will cause grain growth, oxidation or overburning, seriously affecting the quality of the workpiece. During heat treatment, the hardness and strength of steel can be improved if it is heated to a point above the critical temperature and then cooled suddenly. If heated to a point below the critical temperature and cooled slowly, the hardness of the steel can be reduced and the toughness improved.
In order to obtain accurate scale and clean appearance of the workpiece, or in order to reduce the metal oxidation to protect the mold, reduce the machining allowance and other purposes, can choose a variety of less oxidization-free heating furnace. In the open flame less oxidization-free heating furnace, the recovery gas is generated by the incomplete combustion of fuel, in which the workpiece is heated, the oxidation loss rate can be reduced to less than 0.3%.
Controlled atmosphere furnace is the use of artificial atmosphere, through the furnace can be gas carburizing, carbonitride, light quenching, normalizing, annealing and other heat treatment: to achieve the purpose of changing the metallographic arrangement, improve the mechanical properties of the workpiece. In the live particle furnace, the burning gas of fuel or other fluidized agent applied externally is used to force through the graphite particles or other lazy particles layer on the furnace bed. The workpiece buried in the particle layer can be enhanced heating, carburizing, nitriding and other non-oxidation heating. In the salt bath furnace, using molten salt as the heating medium can prevent the oxidation and decarburization of the workpiece. When cast iron is smelted in cupula, it is usually affected by coke quality, air supply method, charge condition and air temperature, etc., which makes it difficult to be stable and obtain high quality molten iron. The hot air cupola can effectively improve the temperature of molten iron, reduce the alloy burning loss and reduce the oxidation rate of molten iron, so as to produce high-grade cast iron.
With the appearance of coreless induction furnace, cupola tends to be replaced gradually. The induction furnace smelting operation is not restricted by any cast iron grade, and can be quickly converted from one grade of cast iron to another grade of cast iron, which is conducive to improving the quality of molten iron. Some special alloy steels, such as ultra-low carbon stainless steel and steel used in rollers and turbine rotors, require the molten steel smelted in open hearth furnace or general arc furnace to be further refined by vacuum degassing and argon stirring.
The fuel origin of the flame furnace is wide, the price is low, it is convenient to adopt different structure according to the suit, which is conducive to reduce the production cost, but the flame furnace is difficult to complete accurate control, severe environmental pollution, low thermal efficiency. The characteristics of electric furnace are uniform furnace temperature and easy to complete active control, good heating quality. According to the method of energy conversion, electric furnace can be divided into resistance furnace, induction furnace and arc furnace. The furnace heating capacity calculated per unit time per unit bottom area is called furnace yield. The faster the heating speed of the furnace and the larger the load of the furnace, the higher the yield of the furnace. In general, the higher the furnace yield, the lower the unit heat consumption per kilogram of material. Therefore, in order to reduce energy consumption, should be full load production, as far as possible to improve the furnace production rate, together with the burning equipment fuel and combustion air active share regulation, in order to prevent excess or lack of air. In addition, the loss of heat storage and heat dissipation of furnace wall, heat loss of water-cooled components, loss of radiant heat of all kinds of openings and heat loss of flue gas away from the furnace should also be reduced.
The ratio of the heat absorbed by the metal or material during heating and the heat supplied into the furnace is called furnace thermal efficiency. Continuous furnace than intermittent furnace thermal efficiency is high, because of the high yield rate of continuous furnace, and is continuous operation, the furnace thermal system is in stable condition, no periodic furnace wall heat loss, but also because of internal have a preheating furnace burden section, because some flue gas waste heat for the furnace internal have a preheating furnace charge of section, some flue gas waste heat is absorbed by cold artifacts into the furnace, fell from the furnace flue gas temperature.
On 2018-08-08 11:45:46
