Scrap Pre-Heating System

1.Long use life, competitive rate and service;
2.Customized design, ISO,DIN,GB,ASTM standard fabricate andmaterial;
3.SGS,INTERTEK inspection service provided;
4.Punctual delivery, high end quality, and attentive service aftersale;
5.CE,ISO certified;
Scrap Pre-Heating System
The use of scrap preheating technology can effectively shorten the smelting cycle and reduce smelting consumption;so far, the existing technology mainly uses electric furnace high-temperature flue gas to preheat scrap steel; there aretwo main ways to use electric furnace high-temperature flue gas to preheat scrap steel: direct Preheating method andindirect preheating method; the direct preheating method is characterized by connecting the flue gas extracted from theelectric furnace to preheat the scrap steel, while the indirect preheating method uses the extracted flue gas to first heatthe air and then use it to be heated Preheated steel scrap with the cooled air. Obviously, in terms of the effective
utilization of the heat contained in the flue gas of the electric furnace, the direct method is better than the indirect method.At present, the relatively advanced scrap preheating technology mainly has the following 6 methods:
①Basket preheating: This method introduces high-temperature exhaust gas from the furnace of the electric furnace intothe preheating tank, and then preheats the scrap in the basket. In order to extend the service life of the basket, the
temperature in the basket must be controlled, and the temperature cannot be too high.Generally, the inlet temperature is700°℃ to 800℃, and the outlet temperature is 200°℃ to 300°℃.The energy-saving effect of this preheating method is25kwhlt on average, but the disadvantage is that the preheating process is accompanied by smoke and odor.

One electric two furnace type: This method is characterized by using one power source and two furnaces, one ofwhich is used for steelmaking,and the exhaust gas generated by it is introduced into another furnace containing scrapsteel for preheating, and then cycle operation . This not only solves the pollution problem caused by the preheatingbasket method, but also enables the preheated steel scrap to reach a high temperature above 1000 °C, and thepreheating effect is more efficient, in addition, this technology also omits the tapping, furnace repair and the first timeNon-energized time such as furnace installation, thereby improving productivity. The energy saving effect of this processis obvious: when the preheating rate of scrap steel is 60%, the electric energy saving is 35-40kwh/t steel; when thepreheating rate reaches 100%, the electric energy saving can reach 65kwh/t steel.
Shaft furnace method: The structural characteristics of the shaftfurnace method preheating process are: the water-cooled shaft furnace and the electric furnace cover are connected as a whole, and scrap steel is loaded inside, and thehigh temperature exhaust gas rising in the electric furnace hearth is used for preheating.In order to achieve the purposeof continuously preheating the scrap of each heat, hooks are installed at the lower part of the shaftfurnace to supportand control the falling scrap; the disadvantage is that in order not to affect the position of the furnace top electrode in thecenter of the furnace, the shaft can only be biased toward the electric furnace On one side , the scrap steel in the furnaceis heated unevenly and the melting is not synchronized.The energy saving effect of this technology is about 30kwh/tsteel.
④Preheating in the continuous conveying layer. This process is referred to as the NSCF process, which aims to solvethe problem of uneven preheating of scrap steel on the conveyor belt in the CONSTEEL process. Therefore, an exhaustgas outlet is installed at the lower part of the enclosed conveyor belt, so that the exhaust gas preheats the scrap from topto bottom, so that the temperature of the scrap at a distance of 600mm ~700mm from the surface of the conveyor belt isincreased from <100℃ to >400C; the energy saving effect can be achieved. 65kwh/t steel.

⑤Shaft furnace continuous installation: The structural feature of this process is that the top of the device such as thereceiving hopper, exhaust pipe, preheating tank and pusher are allocated on the upper part of the furnace center, thescrap steel is preheated by high temperature exhaust gas. The feeder is pushed to the center of the top of the electricfurnace and then falls into the furnace; its energy saving effect can reach 138kwh/t steel, which has attracted wideattention.

⑥Filing layer electric furnace method: This technical feature is the scrap steel is continuously charged around the topelectrode of the electric furnace to form a filling layer in the furnace, and then it is preheated by the rising high
temperature exhaust gas. Specifically, the scrap steel transported by the conveyor belt is loaded into the surroundingdirection of the electric furnace furnace with a rotating magnet, in order to ensure that the exhaust gas can flow evenlyand preheat in the filling layer scrap steel, an annular pipe is installed on the upper part of the furnace. The disadvantageis that this process is easily restricted by the geometry of the scrap steel; another key point is to ensure the heat
resistance and reliability of the scrap steel loading equipment.