Dry centrifugal granulation heat recovery system utilizing powder anti-slagging

Abstract

The application discloses a dry centrifugal granulation heat recovery system using powder anti-slagging, which comprises a powder distributor, a centrifugal granulation bin and a fixed fluidized bed; characterized in that: the top of the centrifugal granulation bin is provided with a slagging-off port and a hot air outlet, the bottom is provided with an air inlet, a granulator is arranged in the centrifugal granulation bin and is rotated by a driving motor; a gravity inclined plate is arranged below the granulator; the lower end of the gravity inclined plate is communicated with the fixed fluidized bed, and the fixed fluidized bed is used for secondary heat recovery of molten slag particles; a slagging-off port is arranged at the bottom of the fixed fluidized bed; a plurality of powder distributors are uniformly arranged on the top outer periphery of the centrifugal granulation bin, a screw feeder is arranged in the powder distributor, the lower part of the powder distributor is a discharging bin, and the discharging bin is communicated with the centrifugal granulation bin; a plurality of discharging grooves are uniformly arranged on the inner wall surface of the discharging bin; the powder entering the powder distributor is uniformly spread in the discharging grooves under the action of gravity and the screw feeder, so that the powder can uniformly enter the centrifugal granulation bin; and the application can be widely applied in the fields of energy, steel, chemical industry and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of molten slag centrifugal granulation heat recovery, in particular to a dry centrifugal granulation heat recovery system using powder to prevent molten slag adhesion. BACKGROUND

[0002] The temperature of high-temperature liquid molten slag exceeds 1400℃, such as blast furnace slag generated in the process of blast furnace ironmaking, molten slag generated in the process of solid waste melting treatment, and other slag discharged in the process of ore thermal production, which has a very high grade of waste heat. In industry, the treatment of molten slag mostly adopts water quenching process, specifically, molten slag is directly contacted with water for rapid cooling to form molten slag glass body which can be further utilized, such as used as a partial substitute for cement. However, this process wastes water resources and high-temperature waste heat, and water and molten slag can generate polluting gas which is discharged into the atmosphere with steam.

[0003] To solve the problems existing in the water quenching process, dry granulation technology is proposed and developed, which can break molten slag into small droplets, realizing the quality of waste heat recovery and material resource utilization. Among them, the centrifugal granulation technology has the advantages of compact structure, good granulation effect, low energy consumption, and no water consumption, which is recognized as the most promising technology in the industry. However, the problem of molten slag adhesion in the granulation process will lead to difficult slag discharge and affect the reliability of system operation, which becomes one of the key technical bottlenecks of this technology, and the industrial application of centrifugal granulation technology has not been realized. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a dry centrifugal granulation heat recovery system using powder to prevent molten slag adhesion.

[0005] The technical solution of the present application is a dry centrifugal granulation heat recovery system using powder to prevent molten slag adhesion, which comprises a powder distributor, a centrifugal granulation bin and a fixed fluidized bed; characterized in that: the top of the centrifugal granulation bin is provided with a slag discharge port and a hot air outlet, and the bottom is provided with an air inlet, a granulator is arranged in the centrifugal granulation bin, and the granulator is driven to rotate by a driving motor; a gravity inclined plate is arranged below the granulator; the lower end of the gravity inclined plate is communicated with the fixed fluidized bed, and the fixed fluidized bed is used for secondary heat recovery of molten slag particles; and a slag discharge port is arranged at the bottom of the fixed fluidized bed.

[0006] A plurality of powder distributors are uniformly arranged on the outer periphery of the top of the centrifugal granulation bin, a screw feeder is arranged in each powder distributor, the lower part of each powder distributor is an outlet bin, and the outlet bin is communicated with the centrifugal granulation bin; a plurality of outlet grooves are uniformly arranged on the inner wall surface of the outlet bin; and the powder entering the powder distributor is uniformly spread in the outlet grooves under the action of gravity and the screw feeder, so as to ensure that the powder uniformly enters the centrifugal granulation bin.

[0007] The molten slag is poured from a slag pouring opening at the top of the centrifugal granulation bin into a granulator driven by a driving motor, and is broken into small droplets in the internal space of the centrifugal granulation bin by the action of centrifugal force, exchanges heat with air, and is cooled and solidified into particles to obtain high-temperature air, and the cooled and solidified particles are wrapped by powder in the centrifugal granulation bin, thereby weakening the interaction between the molecules of the molten slag and reducing the viscosity, preventing the adhesion between the particles and the wall surface; then the particles roll down to a gravity inclined plate and are pushed into a fixed fluidized bed by gravity for secondary heat recovery, the fixed fluidized bed absorbs the heat of the wrapped powder particles according to a physical or chemical heat recovery method, and finally the particles are discharged from a slag outlet for subsequent processing and utilization.

[0008] According to the preferred scheme of the dry-type centrifugal granulation heat recovery system for preventing molten slag adhesion by using powder, an air inlet is arranged at the lower part of the fixed fluidized bed, an air outlet is arranged at the upper part, an air exhaust fan is arranged at the air outlet to exhaust the gas in the fixed fluidized bed, and a long and narrow channel is arranged at the connection between the centrifugal granulation bin and the fixed fluidized bed, and is matched with a screw feeder to fill the channel with particles and send the particles into the fixed fluidized bed, preventing the gas in the fixed fluidized bed from flowing back into the centrifugal granulation bin.

[0009] According to the preferred scheme of the dry-type centrifugal granulation heat recovery system for preventing molten slag adhesion by using powder, the air inlet is connected to mixed gas of biogas and flue gas, the powder entering the powder distributor is metal powder with strong magnetism and catalytic activity, the mixed gas is subjected to endothermic remanufacturing and synthesis of methane under the catalytic action of the catalytically active metal powder and the slag catalyst, and the gas exhausted from the air outlet is introduced into a Fischer-Tropsch synthesis reaction device to produce liquid hydrocarbon or hydrocarbon, thereby completing secondary heat recovery.

[0010] According to the preferred scheme of the dry-type centrifugal granulation heat recovery system for preventing molten slag adhesion by using powder, the powder is metal powder with magnetism, the slag outlet is connected to a ball mill, the molten slag particles wrapped by the powder discharged from the slag outlet are crushed and ground into slag-containing powder by the ball mill, the strong magnetism of the metal powder is utilized to complete physical separation of the metal powder from the slag powder by an electromagnetic suction disc during the conveying process, the slag powder is sent to subsequent processing and used as a cement admixture for producing Portland cement and concrete, and the metal powder is sent into the powder distributor again.

[0011] According to the preferred scheme of the dry-type centrifugal granulation heat recovery system for preventing molten slag adhesion by using powder, a heat exchanger is arranged in the fixed fluidized bed to recover the residual heat of the molten slag particles.

[0012] The dry-type centrifugal granulation heat recovery system for preventing molten slag adhesion by using powder has the following beneficial effects:

[0013] This dry centrifugal granulation heat recovery system for preventing slag adhesion uses a powder distributor to uniformly supply powder. Under centrifugal force, the liquid slag breaks down into tiny droplets, which exchange heat with the air, solidify, and fly to the powder-covered centrifugal granulation chamber wall. The powder encapsulates the droplets, increasing the surface roughness of the solidified particles and thus preventing adhesion during the centrifugal granulation process. The system then continues to perform secondary heat recovery in a fixed self-flowing bed, resulting in significant energy-saving and emission-reduction benefits. It can be widely used in energy, steel, chemical and other fields. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a dry centrifugal granulation heat recovery system for preventing powder slag adhesion as described in this invention.

[0015] Figure 2a This is a partial cross-sectional view of the powder distributor 1.

[0016] Figure 2b This is a schematic diagram of the discharge trough 13 in the powder distributor 1.

[0017] Figure 2c This is a schematic diagram of the powder distributor 1.

[0018] Figure 3 yes Figure 1 Top view.

[0019] Figure 4 Example 1 is a schematic diagram of a fixed self-flowing bed using a chemical heat recovery method.

[0020] Figure 5 Example 2 is a schematic diagram of a fixed self-flowing bed utilizing a physical heat recovery method. Detailed Implementation

[0021] The following is combined Figures 1 to 5 The present invention will be further described in detail below with reference to specific embodiments.

[0022] A dry centrifugal granulation heat recovery system utilizing powder to prevent molten slag adhesion includes a powder distributor 1, a centrifugal granulation chamber 2, and a fixed gravity-flow bed 4. The centrifugal granulation chamber 2 has a slag discharge port 23 and a hot air outlet 24 at its top, and an air inlet 25 at its bottom. A granulator 22 is installed inside the centrifugal granulation chamber 2, and the granulator 22 is driven to rotate by a drive motor 21. A gravity inclined plate 3 is located below the granulator 22. This gravity inclined plate 3 is inclined to ensure that particles rolling onto it automatically fall into the fixed gravity-flow bed 4 by gravity. The lower end of the gravity inclined plate 3 is connected to the fixed gravity-flow bed 4, which is used for secondary heat recovery of the molten slag particles. A slag outlet 41 is located at the bottom of the fixed gravity-flow bed 4.

[0023] The top periphery of the centrifugal granulation bin is uniformly provided with a plurality of powder distributors 1, the top of the powder distributor 1 is a feeding bin 11, and a screw feeder 12 is arranged inside; the lower part of the powder distributor 1 is a discharging bin, the discharging bin is arranged in an inclined manner, and the discharging bin is in communication with the centrifugal granulation bin 2; a plurality of discharging grooves 13 are uniformly arranged on the inner wall surface of the discharging bin, the discharging grooves 13 are spread in a scattered manner, and specific reference can be made to Figure 2a 、 Figure 2b , Figure 2c The width of the groove gradually increases in the direction of the powder outlet, the powder entering the powder distributor 1 is uniformly spread in the discharging groove 13 under the action of gravity and the screw feeder, so as to ensure that the powder uniformly enters the centrifugal granulation bin 2; the powder can be replaced in kind as needed, and the particle size of the powder is kept at the micron level; at the same time, a flow baffle 14 is arranged below the screw feeder to control the flow size of the supplied powder.

[0024] The molten slag is poured from the slag pouring port 23 at the top of the centrifugal granulation bin, falls onto the granulator 22 driven by the driving motor 21, and is broken into fine droplets in the internal space of the centrifugal granulation bin under the action of centrifugal force, exchanges heat with air, and is cooled and solidified into particles, obtaining high-temperature air; the cooled and solidified particles are wrapped by the powder entering the centrifugal granulation bin 2, thereby weakening the interaction between the molecules of the molten slag and reducing the viscosity, preventing the adhesion between particles and between particles and the wall surface; then the particles roll onto the gravity inclined plate 3 and are pushed into the fixed fluidized bed 4 by gravity for secondary heat recovery; the fixed fluidized bed absorbs the heat of the particles according to a physical or chemical heat recovery method, and finally the particles are discharged from the slag outlet 41 for subsequent processing and utilization.

[0025] In specific embodiments, an air inlet 42 is arranged at the lower part of the fixed fluidized bed, and an air outlet 43 is arranged at the upper part; an air extractor is arranged at the air outlet 43 to discharge the gas in the fixed fluidized bed; and the connection between the centrifugal granulation bin 2 and the fixed fluidized bed 4 is arranged as a long and narrow channel, which cooperates with the screw feeder 5 to make the particles fill the channel and enter the fixed fluidized bed, preventing the gas in the fixed fluidized bed from flowing back into the centrifugal granulation bin 2.

[0026] The air inlet 42 introduces mixed gas of biogas and flue gas, and the powder entering the powder distributor 1 is a metal powder with strong magnetism and catalytic activity, such as nickel powder; the mixed gas is subjected to endothermic reforming to synthesize gas in response to the catalytic action of the catalytically active metal powder and the slag catalyst, and the gas discharged from the air outlet 43 is introduced into a Fischer-Tropsch synthesis reaction device 10 to produce liquid hydrocarbons or hydrocarbons, thereby completing secondary heat recovery.

[0027] A heat exchanger is arranged in the fixed fluidized bed to recover the residual heat of the molten slag particles.

[0028] The slag outlet 41 is connected with the ball mill 6; the slag particles wrapped by the powder discharged from the slag outlet 41 are crushed and ground into the powder containing the slag by the ball mill 6, and the strong magnetism of the metal powder is facilitated, and the physical separation of the metal powder and the slag powder is completed by the electromagnetic chuck 8 during the conveying process of the conveying belt 7; the slag powder is sent to the subsequent treatment and used as the admixture for producing the Portland cement and the concrete; and the metal powder is sent into the powder diverter again.

[0029] Example 1: As a typical representative of renewable energy, biogas, mainly composed of methane and carbon dioxide, can be obtained by anaerobic fermentation or decomposition of organic matter, and the raw material can be any biodegradable substance, such as sewage sludge, animal manure and organic solid waste in household garbage. Decomposition of methane on a catalyst-loaded carbon dioxide is a method for alleviating "global warming" to produce hydrogen, which utilizes the dry reforming reaction of methane CH4+CO2→2CO+2H2 to synthesize high-value and widely used synthesis gas with a low H2 / CO ratio. The subsequent synthesis gas can be used for the production of liquid hydrocarbons or hydrocarbons through the Fischer-Tropsch synthesis reaction, which can be used as a chemical raw material. This technology has potential environmental benefits in energy conversion and energy storage.

[0030] Since the dry reforming of methane to produce hydrogen is a strong endothermic reaction, referring to Figure 4 , the supplied powder is a metal nickel powder, and the liquid slag is a blast furnace slag. The working principle and process of the powder and the granulation are not repeated. Nickel metal is a commonly used catalyst that helps the adsorption and dissociation of methane. The smaller the nickel metal particles, the more conducive to the reaction, and also prevent sticking during the granulation of the molten slag. In the fixed fluidized bed 4, biogas obtained by anaerobic fermentation or decomposition of organic matter and flue gas from complete combustion of fossil fuels are introduced at the same time, and the liquid blast furnace slag has a temperature of 700-1000℃ after one heat recovery through granulation. Under the catalytic action of the nickel-based-slag catalyst formed by the metal nickel powder wrapping the broken blast furnace slag, the endothermic reforming of methane to synthesis gas occurs when the gas contacts the surface of the molten slag. The gas discharged from the gas outlet 43 is introduced into the Fischer-Tropsch synthesis reaction device 10 to produce liquid hydrocarbons or hydrocarbons, thereby completing the secondary heat recovery. To avoid backflow of synthesis gas in the fixed fluidized bed and ensure the flow direction to the outlet, the connection between the centrifugal granulation bin 2 and the fixed fluidized bed 4 is set as a narrow channel, and cooperates with the screw feeder 5 to make the particles fill the channel and enter the fixed fluidized bed, preventing the gas in the fixed fluidized bed from flowing back into the centrifugal granulation bin 2.

[0031] The slag particles after chemical heat recovery are discharged from the slag discharge port 41 into the ball mill 6 for crushing and grinding into a powder containing slag glass and metal nickel. Since the nickel metal has strong magnetism, the physical separation of nickel powder from slag is completed by the electromagnetic chuck 8 during the conveying process of the conveying belt 7: the slag powder is sent to subsequent processing and used as a cement admixture for producing Portland cement, concrete; the nickel powder can be reused and continuously fed into the powder diverter 1.

[0032] The embodiment utilizes metal nickel powder to solve the slag bonding problem in the centrifugal granulation waste heat recovery technology, saves the energy consumption of methane dry reforming, improves the quality and storage convenience of biogas, and converts a large amount of CO2 gas generated by combustion of fossil fuels, thereby realizing the green energy-saving and emission-reducing environmental protection technology.

[0033] Embodiment 2

[0034] Referring to Figure 5 , the supplied powder is the powder after crushing of the cooled blast furnace slag, and the working principle and process of powder addition and granulation are the same as those of embodiment 1. Different from embodiment 1, no gas inlet and gas outlet are arranged at the lower part and the upper part of the fixed fluidized bed. Instead, a heat exchanger 10 is arranged in the fixed fluidized bed 4 by using a physical heat recovery method, water working medium is arranged in the heat exchanger, the waste heat of the granulated slag particles is recovered for the second time to obtain water vapor. The completely cooled slag particles are discharged from the slag discharge port 41 into the ball mill 6 for crushing and grinding into a powder containing slag glass for subsequent use as a cement admixture for producing Portland cement, concrete and other application scenarios.

[0035] The above only describes the preferred embodiments of the present application and is not used to limit the present application. Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacement of part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A dry centrifugal granulation heat recovery system with powder anti-slagging bonding, comprising a powder diverter (1), a centrifugal granulation bin (2) and a fixed fluidized bed (4); characterized in that: The top of the centrifugal granulation bin (2) is provided with a slag pouring port (23) and a hot air outlet (24), and the bottom is provided with an air inlet (25). A granulator (22) is arranged in the centrifugal granulation bin (2), and the granulator (22) is driven to rotate by a driving motor (21). A gravity inclined plate (3) is arranged below the granulator (22). The lower end of the gravity inclined plate (3) is connected with a fixed fluidized bed (4) in communication, and the fixed fluidized bed (4) is used for secondary heat recovery of molten slag particles. The bottom of the fixed fluidized bed (4) is provided with a slag discharge port (41). A plurality of powder distributors (1) are uniformly arranged on the top outer periphery of the centrifugal granulation bin. A screw feeder (12) is arranged in the powder distributor (1). The lower part of the powder distributor (1) is a discharge bin, which is connected with the centrifugal granulation bin (2) in communication. A plurality of discharge grooves (13) are uniformly arranged on the inner wall surface of the discharge bin. The powder entering the powder distributor (1) is uniformly spread in the discharge grooves (13) under the action of gravity and the screw feeder, so as to ensure that the powder uniformly enters the centrifugal granulation bin (2). The molten slag is poured from the slag pouring port (23) at the top of the centrifugal granulation bin, falls on the granulator (22) driven by the driving motor (21), and is broken into fine droplets in the internal space of the centrifugal granulation bin under the action of centrifugal force, exchanges heat with air, and is cooled and solidified into particles after heat exchange, so as to obtain high-temperature air. The cooled and solidified particles are wrapped by the powder entering the centrifugal granulation bin (2), thereby weakening the interaction between the molten slag molecules and reducing the viscosity, preventing the adhesion between the particles and the wall surface. Then the particles roll down to the gravity inclined plate (3) and are pushed into the fixed fluidized bed (4) by gravity for secondary heat recovery. The fixed fluidized bed absorbs the heat of the particles according to physical or chemical methods. Finally, the particles are discharged from the slag discharge port (41).

2. A dry centrifugal pelletizing heat recovery system utilizing powder anti-slag binding according to claim 1, characterized in that: An air inlet (42) is arranged at the lower part of the fixed fluidized bed, and an air outlet (43) is arranged at the upper part. An air extractor is arranged at the air outlet (43) to discharge the gas in the fixed fluidized bed. The connection between the centrifugal granulation bin (2) and the fixed fluidized bed (4) is arranged as a narrow channel, which cooperates with the screw feeder (5) to fill the channel with particles and send them into the fixed fluidized bed, preventing the gas in the fixed fluidized bed from flowing back into the centrifugal granulation bin (2).

3. A dry centrifugal pelletizing heat recovery system utilizing powder anti-slag binding according to claim 2, characterized in that: The air inlet (42) introduces a mixture of biogas and flue gas, and the powder entering the powder distributor (1) is a metal powder with strong magnetism and catalytic activity. The mixture undergoes endothermic reforming to synthesize gas under the catalytic action of the metal powder with catalytic activity and the slag catalyst. The gas discharged from the air outlet (43) is introduced into a Fischer-Tropsch synthesis reaction device (9) to produce liquid hydrocarbons or hydrocarbons, thereby completing the secondary heat recovery.

4. The dry centrifugal granulation heat recovery system utilizing powder anti-slagging bonding of claim 1, wherein: The slag outlet (41) is connected with the ball mill (6); the slag particles wrapped by the powder discharged from the slag outlet (41) are crushed and ground into the powder containing the slag by the ball mill (6), and the physical separation of the metal powder and the slag powder is completed by the electromagnetic chuck (8) during the conveying process of the conveying belt (7) by the strong magnetism of the metal powder; the slag powder is sent to the subsequent treatment and used as the admixture for producing the Portland cement and the concrete; and the metal powder is sent into the powder diverter again for recycling.

5. A dry centrifugal pelletizing heat recovery system utilizing powder anti-slagging bonding as claimed in claim 1, characterized in that: A heat exchanger is arranged in the fixed self-flow bed to recover the residual heat of the slag particles.

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