9481results about "Waste heat treatment" patented technology

The present invention provides a fuel feeding apparatus and method for improving the controllability of mixing process and mixing ratio of fuel and combustion air, and a combustion system and method for effecting new combustion properties. The fuel feeding apparatus of the combustion system has fuel feeding means, combustion gas extraction means, steam supply means, mixing means and fuel gas introduction means. The combustion gas extraction means extracts combustion gas of a combustion area therefrom. The mixing means mixes the fuel of fuel feeding means with at least one of combustion gas extracted from the furnace and steam of a steam generator. The fuel gas introduction means introduces a mixed fluid of combustion gas, steam and fuel to the combustion area as a fuel gas, and allows the fuel gas to be mixed with the combustion air. A step of mixing the fuel with the combustion gas after extracted from the furnace and a step of mixing the fuel gas with the combustion air are stepwisely carried out, so that the controllability of mixing process and ratio of the air and fuel is improved. Such a control of fuel gas flow enables control of characteristics of flame and production of flame with new properties in the combustion area.

The Portable Renewable Energy System for Enhanced Oil Recovery (“PRESEOR”) is a truck mobile system that reforms biomass into CO2 and hydrogen, following which the gases are separated, with the CO2 sequestered underground for enhanced oil recovery (EOR) and the hydrogen used to generate several megawatts of carbon-free electricity. In contrast to large central power plants that are generally not well-located to support EOR, the small PRESEOR can go directly to the oilfields where it is needed, and do so in a timely manner. The PRESEOR sequesters more biomass-derived carbon than is released by the burning of the oil it yields, thereby producing not only carbon-free electricity but carbon-free oil. Using PRESEOR, over 80 billion barrels of U.S. oil would be made recoverable, without the need to drill new wells in pristine areas.

An oxygen enrichment system is provided which uses the existing air / fuel burners of a regenerative furnace to distribute additional oxygen to the burners for increased efficiency, and reduced nitrous oxide emissions. The centrally positioned cooling air lances in the burners of a regenerative furnace are modified to deliver oxygen when the burners are firing for oxygen enrichment. During the burmer firing cycle, oxygen is delivered from an oxygen supply through the oxygen lance to provide a central oxygen jet. The fuel is delivered concentrically around the oxygen jet. During the non-firing cycle of the burner, cooling air or other cooling fluid is delivered from the cooling air supply through the oxygen jet for cooling the offside of the furnace.

A synthetic slag is produced by a high temperature combustion reaction between coal ash having a high carbon content, and a source of lime such as cement kiln dust. The carbon content of the coal ash is oxidized by oxygen gas, which typically is derived from air or an air / oxygen combination in an exothermic reaction and the heat generated is exploited in the melting process. In this way the gaseous products will typically comprise nitrogen, unreacted oxygen and carbon dioxide, and heat energy can be readily recovered from the hot off gas products evolving during the combustion reaction. The synthetic slag may be pelletized and employed as lightweight mineral aggregate or milled to cement fineness to provide slag cement.

A treatment system to efficiently remove lead from dust contained in extracted cement kiln combustion gas while reducing facility and running costs. A treatment system 1 comprising a probe 3 for extracting a part of combustion gas, while cooling it, from a kiln exhaust gas passage, which runs from an inlet end of a cement kiln to a bottom cyclone; a first classifier 5 for separating coarse powder from dust contained in the combustion gas extracted; a dust collector 7 for collecting dust from the extracted gas containing fine powder discharged from the first classifier 5; and a second classifier 8 for dividing dust discharged from the dust collector 7 into fine powder and coarse powder, and others. Since more lead is distributed on the fine powder side classified by the second classifier 8, lead can efficiently be removed without using chemicals and the like. The fine powder classified by the classifier 8 may be desalted by washing; high-lead-level cake obtained after the washing can be recycled; or salt water can be added to a cement mill. The coarse powder may be added to a cement grinding process or returned to cement material grinding process after the desaltation through washing.

The invention provides a melting furnace slag quenching dry type granulation and sensible heat recovery generating system and a method using the same and belongs to the technical field of steel metallurgy furnace slag treatment and complementary energy recovery. The melting furnace slag quenching dry type granulation and sensible heat recovery generating system provided by the invention comprisesa slag-receiving device, a high-pressure water-air pulverization furnace slag quenching and granulating device, a furnace slag slow-cooling device, a sensible heat recovery generating device and a waste gas purification treatment device. According to the invention, the melting furnace slag is quenched and granulated by utilizing the high-pressure water-air pulverization device, so that the melting furnace slag is rapidly cooled to be in a glassy state; and then through a water-cooled type vibration grid plate, the melting furnace slag in the glassy state is further subjected to heat exchange with cold air so as to facilitate the subsequent recovery of the sensible heat. By the system provided by the invention, the melting furnace slag is quenched and granulated, and the high-temperature sensible heat resource of the furnace slag is sufficiently recovered and is used for generation on the basis that the water activity quality of the furnace slag is not influenced.

The invention relates to a method for effectively recycling and utilizing residual heat resources in a sintering process and a device thereof. The invention has the main contents that a fiery sinter ore is filled in a vertical and sealed tank body, air is led from the tank body so as to cool the sinter ore, sensible heat of the sinter ore is almost totally carried by the air and is exhausted fromthe top of the tank body at the same time; and hot air is led into a residual heat boiler to generate steam to synchronously generate power. Compared with the prior sintering residual heat recycling and utilization technology, the invention has higher residual heat recycling utilization ratio, effectively reduces the energy consumption of the sintering procedure with reasonable and effective method, simple apparatus and easy operation, and is relatively favorable for popularization and application in the technical field of residual heat resource recycling and utilization in a metallurgy process.

A molten metal rotor receives and retains an end of a molten metal rotor shaft. The rotor shaft has one or more projections at the end received in the rotor. The rotor has an inner cavity, a top surface with an opening leading to the inner cavity, and at least one abutment. The opening includes one or more portions for allowing each projection to pass through the opening and into the inner cavity. The rotor and / or shaft are then rotated so at least one of the outwardly-extending projections is under the top surface of the rotor and is against an abutment. A molten metal pump, rotary degasser scrap melter or other device used in molten metal may utilize a rotor / shaft combination as disclosed herein.

The invention discloses a sintering flue gas desulfurization cycle enrichment methods and device, the described method from the sintering machine take part gas return to the top of sintering machine sealed enclosures within cycle, while complementing sintering machine burning need oxygen, the remaining part of the flue gas discharge after desulfurization. In devices, including dedusting device of flue gases between the chimney and flue, in the road before the desulfurization setup a branch pipeline to connect sintering machine sealed enclosures, in the branches of pipe setup cycle fan and supplement device. This invention due to sintered exhaust gas partly return to the seal trolley of sintering machine to reduce the displacement of gas, thereby reducing the total of dust and exhaust gas, while the SO2 of the sintering process play a enrichment role, to increase desulfurization efficiency, and reduce release total of burning exhaust gas, reducing the processing load of desulfurization device.

A coupling has an opening and a protrusion extending downward from the opening. The protrusion has threads that are preferably positioned outside of the opening. A rotor shaft that connects to the coupling has an internal bore with threads that receives and retains the protrusion, such as by a threaded connection between the two, so the protrusion applies driving force to the shaft.

PCT No. PCT / JP95 / 01916 Sec. 371 Date May 23, 1996 Sec. 102(e) Date May 23, 1996 PCT Filed Sep. 22, 1995 PCT Pub. No. WO96 / 09496 PCT Pub. Date Mar. 28, 1996With respect to a radiant tube burner to be used for heating a heating furnace or the like, to suppress the generation of NOx accompanying combustion, to make the structure thereof fit for a radiant tube burner equipment, to simplify the control of a fuel supply system and an air supply system, and to prevent the coking. Furthermore, to provide a combustion control scheme appropriate to a radiant tube burner. For these purposes, the present invention placed the respective tips of a fuel nozzle, e.g., pilot burner joint-use nozzle (11), and an air throat (13) in the end of a radiant tube (3) and moreover has a combustion air injection port (33) of the air throat (13) provided to be deviated in contact with or near to the inner circumferential wall surface of the radiant tube (3). In addition, a control device (307) for making a burner burn alternately.

The invention discloses a system and a method for using sintering waste heat to generate electricity and belongs to the technical field of sintering waste heat electricity generation of the steel works. The system comprises a sintering machine, a hot gas outlet pipe, a gas waste heat boiler, a main exhaust fan, a ring cooling machine, a first and second stage heat waste gas collecting pipe, a waste gas heat boiler, a draught fan, a circulating fan, a chimney, a low pressure steam drum, a middle pressure steam drum, a feed pump, a pressure reducing valve, a collecting header, a steam turbine, a generator, a condenser and a condensate pump. The invention realizes utilizing the waste heat of the non-desulfurization flue header of the sintering machine without arranging an inducing fan by reasonably designing the hot gas connecting mode of the air box at the tail part of the sintering machine and the gas resistance of the waste gas heat boiler. First and second stage sealing covers of the ring cooling machine are uniformly provided with a plurality of waste gas branch pipes so as to realize uniform distribution of the waste gas pressure in the sealing covers and reduce air leakage. Part of waste gas is adopted to circulate to improve the temperature of the waste gas. Compared with the existing system for using sintering waste heat to generate electricity, the system of the invention sufficiently uses the waste heat of the sintering system, improves the waste heat generated energy and reduces the operation cost.

The Portable Renewable Energy System for Enhanced Oil Recovery (“PRESEOR”) is a truck mobile system that reforms biomass into CO2 and hydrogen, following which the gases are separated, with the CO2 sequestered underground for enhanced oil recovery (EOR) and the hydrogen used to generate several megawatts of carbon-free electricity. In contrast to large central power plants that are generally not well-located to support EOR, the small PRESEOR can go directly to the oilfields where it is needed, and do so in a timely manner. The PRESEOR sequesters more biomass-derived carbon than is released by the burning of the oil it yields, thereby producing not only carbon-free electricity but carbon-free oil. Using PRESEOR, over 80 billion barrels of U.S. oil would be made recoverable, without the need to drill new wells in pristine areas.

The invention discloses a method and a system for recovering high-temperature sensible heat of molten blast furnace slag. The system comprises a blast furnace slag runner, a slag hopper, a slag hopper lifting mechanism, a quenching unit, a slow cooling unit, a cold slag particle circulation unit, a cyclone dust collector, a waste heat boiler, a condensing unit, a circulating fan, and a booster fan. The method for recovering waste heat comprises the following steps of: crushing and quickly cooling the molten blast furnace slag in the quenching unit in a composite way of a rotary crushing wheel, high-pressure cold air, a slag trap, cold slag particles and cooling water, and fully exchanging heat with solidified blast furnace slag in the slow cooling unit by using cooling air; and allowing high-temperature air which comes out of the quenching unit and the slow cooling unit to enter the waste heat boiler and performing heat exchange, transforming into steam or electric power and then outputting. The subsequent utilization of blast furnace slag and the waste heat recovery efficiency are synchronously considered, condensed water is recycled, finished slag does not contain water or only contains a small amount of water, the granulation effect of the slag is better, and the contradiction between intermittent slagging and continuous heat production of blast-furnace ironmaking is resolved.

A thermoelectric energy conversion unit includes: a thermoelectric conversion module having plural thermoelectric conversion elements disposed away from each other; a heat receiving member; a cooling member, the cooling member and the heat receiving member holding the thermoelectric conversion module; and a non-oxidizing gas charged in a space formed between the heat receiving member and the cooling member.

A method, and a system for reducing the internal temperature of an electrical solenoid or motor device involves placing a heat absorbing phase change material (PCM) in intimate contact with the device to reduce the internal temperature of the device. The PCM material reduces the internal operational temperature of the device by undergoing an endothermic phase transition in an operating temperature range of the device. The PCM material transitions between a solid phase and a liquid phase in the internal operational temperature range of the device, or between a liquid phase and a gaseous phase in the internal operational temperature range of the device. The PCM material can be affixed externally to the device. For example, the PCM material is affixed in the form of externally placed pads to the device. The PCM material can also be affixed inside of the device. For example, the PCM material is placed in a potted position around and inside of coil windings of the device, or within an outer structure of the device.

The invention discloses a vertical sinter ore cooling machine capable of efficiently recycling the sensible heat of sinter ores, which pertains to the technical field of sintering equipment and is used for preventing air leak in the cooling course of sinter ores and effectively recycling the sensible heat of the sinter ores. The technical proposal of the invention is that: the cooling machine consists of a feeding part, a cooling part and a conveying part; the cooling part comprises a vertical closed body, a hot wind pipeline, a blower, as well as a hopper, an upper sealing valve, a pre-storing chamber, a lower sealing valve, a heat exchanging chamber, a wind distributing board, an isopiestic wind chamber and a discharging channel which are in sequence arranged on the body from top to bottom; an annular wind chamber is arranged between the pre-storing chamber and the heat exchanging chamber; the annular wind chamber is communicated with the hot wind pipeline; the isopiestic wind chamber is communicated with the blower; and wind shields and ore falling openings are distributed evenly on the wind distributing board . The vertical sinter ore cooling machine has the following advantages of: 1. an air leak rate near to 0; 2. improved gas-solid heat exchange efficiency of the cooling machine; 3. raised quality of the recycled hot air; and 4. being beneficial to increasing the utilization rate of exhaust-heat boilers. Based on the advantages, the vertical sinter ore cooling machine is expected to be used commonly as an upgraded replacement of the existing sinter cooling machine.

The invention relates to a residual heat boiler of a steel ball dedusting type ore heat furnace. The residual heat boiler at least comprises a boiler heated surface, a seal boiler flue gas passage, a furnace top and a furnace bottom ash hopper, wherein the boiler heated surface comprises coil pipe groups; and the seal boiler flue gas passage is formed at the periphery of the boiler heated surface. The residual heat boiler is characterized in that the furnace top is provided with a steel ball spreading device, a steel ball separating and collecting device is arranged under the furnace bottom ash hopper; a circulating type steel ball mechanical transporting device is arranged between the steel ball spreading device and the steel ball separating and collecting device; the circulating type steel ball mechanical transporting device comprises at least one drive wheel, at least three driven wheels, a double-row chain, a horizontal guide rail, a steel ball transporting hopper and a mechanical discharge blocking wheel; the at least one drive wheel and the at least three driven wheels are fixed on a boiler frame, and the steel ball transporting hopper is hung on the double-row chain surrounded between the drive wheels and the driven wheels; and the furnace top is provided with the mechanical discharge blocking wheel capable of turning over the steel ball transporting hopper. The invention has simple mechanism, recycled steel ball, mechanical automation running, low investment and running cost and favorable dedusting effect, and the like, can effectively remove and collect accumulated ash and sticking dust on the residual heat boiler heated surface of the ore heat furnace and greatly develops the energy-conservation and emission-reduction technology of the ore heat furnace smelting industry.

The invention relates to the field of energy recovery utilization and in particular to a molten blast furnace slag sensible heat recovery method and a device; the method is characterized in that: themolten blast furnace slag carries out a first heat recovery in a granulator, and then a second heat recovery is carried out by a vibrated bed, and then a third heat recovery is carried out in a fluidized bed, and the reclaimed heat energy is reutilized or converted in a hot air or power generating way; the realization steps are that: 1) the molten blast furnace slag is arranged in the granulator for granulation; 2) the blast furnace slag granules carry out heat exchange in the vibrated bed; 3) the blast furnace slag granules carry out heat exchange in the fluidized bed; 4) after heat exchangeis carried out, the heat is used for power generation from air or is directly utilized in a hot wind way. The method has the beneficial effects that: the sensible heat of the molten blast furnace slagis utilized respectively in a way of waste heat stream power generation and in a way of blast furnace hot wind, compared with the existing water quenching method, 1.0-1.2t of fresh water can be savedwhen processing 1t of molten slag, and sulfides H2S and SO2 are not produced, and energy equivalent to 47kg of standard coal is saved.

The invention relates to a method and burner for injecting pulverized coal into a rotary kiln that uses pulverized coal as fuel in order to produce quick lime of excellent hydration level. The invention calcines lime stone charged into the rotary kiln, and uses pulverized coal as fuel of a heat source applied to the lime stone charged in the rotary kiln. The invention also provides a method and apparatus for producing quick lime by using the pulverized coal. The invention can use pulverized fossil fuel (hereinafter will be referred to as pulverized coal), which is created during coke manufacturing and cooling processes and collected by a dust collector, in order to produce quick lime of excellent hydration level while decreasing SOx (sulfide) and NOx (nitride) generation.

The invention discloses a system and control method for liquid slag dry type centrifugal pelletizing and waste heat recycling. The system comprises a liquid slag draining unit, a liquid slag temporary storage and flow control unit, a liquid slag pelletizing and waste heat recycling unit, and a waste heat utilizing unit. By the adoption of the system and the control method, the temperature and flow of liquid slag entering a pelletizing bin, the liquid slag pelletizing particle size and the moving bed slag discharging temperature can be strictly controlled, thus, the overall technological requirements of the technology are met, and the effect that the system for liquid slag dry type centrifugal pelletizing and waste heat recycling and utilizing operates safely and reliably is guaranteed. All high-quality waste heat resources contained in the high-temperature liquid slag are not wasted, no water resource is consumed, environment pollution is avoided, and the urgent requirements of the current iron and steel industry for energy saving and emission reduction can be met.

The invention discloses a method for reclaiming zinc oxide in treating zincky powder dust in a rotary hearth furnace. The zincky powder dust, coal and flux are mixed, then are subjected to briquetting and drying, are transported to the rotary hearth furnace and are subjected to direct reduction; zinc in the powder dust is reclaimed from exhaust gas; and a feed block of which zinc is removed is directly reduced through the rotary hearth furnace and is subjected to cooling or briquetting for use. The method has wide applicability to zincky materials, can farthest utilize resource reasonably, has low requirement on the thermal value of fuels, high temperature of flue gas and high zinc extraction rate; and the treated powder dust is changed into direct reduced iron for comprehensive utilization.

The invention provides a waste heat recycling system of an annealing furnace. The waste heat recycling system comprises the annealing furnace, an air heat exchanger, a steam boiler, a hot water boiler, an exhaust fan, a combustion fan and a combustion air pipe. The annealing furnace comprises a heating section and a preheating section, the air heat exchanger is connected with the preheating section, the steam boiler is connected with the air heat exchanger, the hot water boiler is connected with the steam boiler, the exhaust fan is connected with the hot water boiler, the steam boiler is connected with a steam pipeline, the hot water boiler is connected with a hot water pipeline, the combustion fan is connected with the air heat exchanger, the combustion air pipe comprises a main pipe and a plurality of branch pipes communicated with the main pipe, one end of the main pipe is connected with the air heat exchanger, the branch pipes are connected with the heating section, and the main pipe is provided with an exhaust pipe and a pipe explosion prevention device. According to the waste heat recycling system of the annealing furnace, waste heat produced in the annealing process can be made full use of, and safety performance of the waste heat recycling system can be fully guaranteed.

The invention relates to the physical heat recovery field of solid high temperature materials. The system can be applied in the waste heat recovery of extra-large high-temperature particles such as high-temperature sintering ore and the like and the process is as follows: the high-temperature sintering ore from a sintering machine falls into a cold sinter furnace through a feeding system, gradually falls with ore discharge and enters a cooling section to radiate heat. The cooled sintering ore enters a vibrator feeder discharging system through a blanking hopper and a regulating gate. The process can be adopted to cool the sintering ore from about 700-800 DEG C to about 100 DEG C. Cold air provided by an air blower enters the cold sinter furnace through an air inlet and a blast cap, absorbs heat in the cooling section and then enters an annular channel, the high-temperature gas from the annular channel enters a waste heat boiler through a dust remover, the heat is transferred to a working medium and then pumped by the draft fan through the dust remover, and the gas is discharged in a chimney when reaching the dedusting standard. The heat-absorbing working medium (usually water) is converted to superheated steam with a certain parameter in the waste heat boiler to do work in a turbine and drive a generator to generate power. Dead steam after doing work enters a condenser and is sent back to the waste heat boiler through a circulating water pump, thus, a thermal cycle is completed.

The invention discloses a method for recovering and utilizing waste heat from low-temperature flue gas. An air-water heat exchanger (4) is connected in series or in parallel in the flue at the rear of the induced draft fan or booster fan (3) of the existing boiler or kiln (1). The inlet port of the hot side of the air-water heat exchanger is connected with the induced draft fan or booster fan (3), the outlet port of the hot side is connected with the desulfurization absorption tower (8) or the chimney (9), and the inlet port of the cold side is circulated with the heat user The outlet pipe or condensate pipe of the water or boiler softened water system is connected, the cold side outlet is connected with the hot user circulating water supply or the boiler feed water pump, and a waterway is connected between the hot side outlet pipe and the cold side inlet pipe of the air-water heat exchanger A bypass pipe, and a waterway bypass regulating valve (5) is arranged on the pipe; a flue gas bypass pipe between the induced draft fan or booster fan and the desulfurization absorption tower (8), and a flue gas bypass pipe A flue bypass regulating valve (6) is arranged on it. By connecting a gas-water heat exchanger in series or in parallel in the flue behind the induced draft fan of the boiler or kiln, the purpose of saving heat energy can be achieved.

The invention provides a selective sintering-machine flue-gas heat exchange and denitration system and a method thereof. The selective sintering-machine flue-gas heat exchange and denitration system comprises a sintering machine (20), a primary heat exchanger (7), a second heat exchanger (8), a denitration device (9), a main dust remover (12) and a desulphurization device (13), wherein a high nitrogen oxide wind box (1) of the sintering machine (20) is sequentially communicated with the primary heat exchanger (7), the denitration device (9), the main dust remover (12) and the desulphurization device (13), and a high-temperature wind box (2) of the sintering machine (20) is communicated with the main dust remover (12) through the primary heat exchanger (7). According to the method, waste heat of high temperature flue gas of the sintering machine and sintered ore cooling equipment is utilized, and heating and temperature increasing of NOx flue gas can be achieved without any external heating source. By the adoption of the system and the method, denitration efficiency of the selected flue gas reaches up to 80%-90%, and therefore NOx emission of the flue gas in the whole sintering machine is superior to a national standard under low investment and operating costs.

The invention discloses a closed microwave high-temperature sintering roller kiln, in particular a tunnel roller kiln with length of 10 to 50meters, and hearth sectional area of 0.06 to 0.3m<2>. The kiln comprises a main kiln body, a microwave transmission system, a turning channel mechanism, a roller power system, and a kiln door interlocking opening and closing system; the main kiln body is formed by connecting a water draining section, a preheating section, a sintering section, a heat preservation section, a quick cooling section, and a slow cooling section in turn; the turning channel mechanism is mainly formed by a material loading and unloading section and a residual-heat utilization blank drying section and comprises a turning channel, a turning channel roller, and a power system; the power system can poke a pushing plate from the outlet of the main kiln body onto the turning channel and feed the pushing plate into the inlet of the main kiln body through the residual-heat utilization blank drying section; and an inner roller for transmitting the material pushing plate, which is driven by the roller power system, is arranged on the bottom of an inner cavity of the main kiln body. The closed microwave high-temperature sintering roller kiln saves energy and reduces consumption and is environmental-friendly, the shrinkage of the sintered products is consistent and the sintered products have high size consistency, the yield is high, the production efficiency is high and the production cost is low.

The invention relates to an emission reduction process by sintering flue gas sulfur dioxide; the flue gas is collected by sections depending on difference sintering zones; the sintering zones include a high SO2 zone and other zones; in the high SO2 zone, the emission of SO2 during sintering accounts for 60 percent to 80 percent of the emission of the SO2 in the whole sintering process, and the flue gas during sintering accounts for 50 percent to 70 percent of the flue gas in the whole sintering process; the flue gas produced in the high SO2 zone is collected, dedusted, desulfurized, denitrated and emitted from a chimney; in a sintering machine, after being collected, the flue gas in other zones is dedusted and emitted from the chimney, or circulated to the sintering machine to be sintered in hot air. The process can reduce the flue gas treatment in flue gas desulfurization, reduces the treated flue gas by 25 percent to 50 percent, so that the concentration of the SO2 in the treated flue gas is two to four times improved; compared with conventional processes, the process can keep the sintering mineral quality basically unchanged, but can improve the desulfurization rate of the flue gas desulfurizing device, and reduce the equipment investment and operation cost of the sintered flue gas desulfurizing device.

The invention relates to a sinter waste-heat utilization process based on the purification of a sintering flue gas. The process solves the problems that the sinter waste-heat utilization ratio is low, the operating cost and investment cost on purification of the sintering flue gas are high, and ammonia escape occurs in ammonia process of desulfurization and the like. The technical scheme provided by the invention comprises the steps of obtaining desulfurated flue gas at 50-60 DEG C led by a sintering machine after dust extraction and ammonia process of desulfurization; carrying out direct heat exchange for sintering at 800-900 DEG C led by the sintering machine with the desulfurated flue gas in a sinter cooling device; detecting the desulfurated flue gas which is heated to be higher than 380 DEG C after heat exchange; if the oxynitride content is lower than the emission standard, discharging the desulfurated flue gas as a purified flue gas; if not, discharging the purified flue gas after SCR denitration; and sending the sinter after heat exchange and temperature reduction in the sinter cooling device to the next step. The sinter waste-heat utilization process based on purification of the sintering flue gas provided by the invention is simple in process, low in device investment and operating cost, high in sinter waste-heat utilization ratio and good in purifying effect of sinter flue gas, and ammonia escape is thoroughly solved.

The invention provides a mehtod for recovering waste heat of steel slag and comprehensively processing and using the steel slag, and belongs to the technical field of steel slag treatment. The method comprises the following steps: a thermal state steel slag material discharging system discharges steel slag into a thermal state steel slag material receiving system for primary crushing; the crushed steel slag is subjected to secondary crushing by a thermal state steel slag velocity control system and quantificationally fed into a thermal state steel slag cooling granulating system for re-crushing and cooling, high-temperaure hot air generatd in the cooling process is collected by a thermal state steel slag waste heat recovery system and enters a heat exchange system to form vapor for power generation or heat supply; the cooled steel slag enters a steel slag stabilizing treatment system, and the steel slag after the stabilizing treatment is treated by a steel slag separation system to obtain steel slag tailing micropowder and metal slag steel respectively; and, the steel slag micropowder is mixed with other materials and used to prepare concrete products by a steel slag concrete product processing preparation system. The method has the advantages of adaptability to various types of steel slag to be processed, good operational environment and no secondary pollution.