Method and device for rapidly converting biomass to recover blast furnace slag waste heat

Abstract

The invention discloses a method and device for rapidly converting biomass to recover blast furnace slag waste heat, and relates to the technical field of blast furnace slag waste heat recovery. The invention aims to solve the problem that the energy of the blast furnace slag cannot be fully utilized. The method provided by the invention comprises the following steps: mixing granulated slag particles with a biomass material in a revolving cup granulator, upwards supplying gas and blowing to enable the slag particles and the biomass material to be fully collided and contacted, and enabling the biomass material to absorb heat and be converted into synthesis gas.

Description

Technical Field

[0001] The present invention belongs to the technical field of slag waste heat recovery, and in particular relates to a method and a device for recovering blast furnace slag waste heat by rapid conversion of biomass. Background Art

[0002] At present, the treatment methods of blast furnace slag in the industry can be roughly divided into two categories: water quenching and dry treatment. The basic principle of the water quenching method is to use high-pressure water to directly impact the high-temperature slag. The slag is cooled rapidly when it contacts the water, and is broken into many porous fine particles with high glass content. After a certain dehydration step, the slag is separated from the water. The obtained slag has a high potential hydraulic activity and can be used as a cement admixture. The dry treatment method often uses physical crushing to process the slag into fine particles. The obtained fine particles are exchanged with air or water-cooled walls to generate high-temperature air or water vapor to achieve waste heat recovery. The water quenching method is currently the more mainstream blast furnace slag treatment method, but because it wastes energy and water resources and produces harmful gases, dry treatment methods have been developed in recent years. Dry treatment methods mainly include mechanical crushing, wind quenching, drum method and centrifugal granulation method, mainly represented by centrifugal granulation method. The advantage of the dry treatment method is that it can recover waste heat in the process, but the utilization of this part of energy is relatively single, usually used to prepare steam. The temperature of the steam produced is single, but smelting enterprises have different requirements for the use of steam at different temperatures, resulting in the waste of the steam produced, which is equivalent to wasting energy. In addition, the problem of adhesion is prone to occur during the granulation of blast furnace slag, which affects subsequent use. In summary, there is a problem in the prior art that the energy of blast furnace slag cannot be fully utilized.

[0003] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the energy of blast furnace slag cannot be fully utilized, and to provide a method and device for rapid conversion of biomass to recover waste heat from blast furnace slag.

[0005] The first aspect of the present invention provides a method for rapidly converting biomass to recover waste heat from blast furnace slag. Granulated slag particles are mixed with biomass material in a rotary cup granulator, and air is supplied upward to blow the slag particles and biomass material so that the two fully collide and contact, and the biomass material absorbs heat and converts to generate synthesis gas.

[0006] In one embodiment of the present invention, the gas supply is in a pulsed manner.

[0007] In one embodiment of the present invention, the pulse period is 1.5S, wherein the gas supply time is 0.5S and the rest time is 1S.

[0008] In one embodiment of the present invention, the air supply pressure is 1-3 Bar.

[0009] The second aspect of the present invention provides a device for rapidly converting biomass to recover waste heat from blast furnace slag, comprising a rotor granulator, wherein the rotor granulator comprises a cavity, a rotor, a slag feeding pipe, a base and a driving device.

[0010] The top of the cavity is provided with an air outlet; a plurality of layers of annular spouted beds are provided in the cavity, the spouted beds are located below the rotating cup, the spouted beds include a bottom wall, an outer wall and an inner wall, the bottom wall is provided with a plurality of groups of pores distributed at equal angles; the outer diameter of each of the spouted beds decreases layer by layer from top to bottom; the top of the outer wall of the spouted bed located in the lower layer abuts against the bottom of the spouted bed located in the upper layer, the outer wall of the spouted bed in the uppermost layer fits against the inner wall of the cavity, and the inner wall of the spouted bed in the lowermost layer fits against the base;

[0011] The cavity is penetrated by a plurality of biomass feeding pipes and particle discharging pipes; the biomass feeding pipe is located above the spouted bed at the uppermost layer and is used to add biomass materials; the particle discharging pipe is connected to the spouted bed at the lowermost layer;

[0012] A fan is arranged outside the cavity, and the fan is connected to a plurality of air ducts. The air ducts extend into the cavity and are used for blowing air upwards from the air holes.

[0013] In one embodiment of the present invention, a water-cooled heat exchanger is provided on the outer wall of the cavity to cool the inner wall of the cavity.

[0014] In one embodiment of the present invention, the water-cooled heat exchanger is located above the uppermost spouted bed.

[0015] In one embodiment of the present invention, a solenoid valve is provided on the air duct.

[0016] In one embodiment of the present invention, the solenoid valve realizes pulsed air supply by intermittent opening and closing.

[0017] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0018] 1. It not only realizes the waste heat recovery of slag particles, but also prepares synthesis gas, so that the waste heat can be fully utilized and higher economic value is obtained.

[0019] 2. Since the high temperature of the slag particles is utilized, no tar is produced in the process of preparing synthesis gas.

[0020] 3. The process of blowing the slag particles can effectively prevent the slag particles from sticking together, thereby not affecting the subsequent use of the slag particles as consumables.

[0021] 4. The process of blowing the slag particles and the biomass material can make the two fully contact and prolong the contact time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 2. It is a schematic structural diagram of a device for rapidly converting biomass to recover waste heat from blast furnace slag according to one embodiment of the present invention;

[0023] Figure 2 It is a three-dimensional half-section diagram of a spouted bed in a device for rapid conversion of biomass to recover waste heat from blast furnace slag according to one embodiment of the present invention.

[0024] Description of main reference numerals:

[0025] 1. Cavity; 2. Rotating cup; 3. Base; 4. Slag feeding pipe; 5. Biomass feeding pipe; 6. Particle discharge pipe; 7. Air duct; 8. Solenoid valve; 9. Spouted bed; 91. Bottom wall; 92. Outer wall; 93. Inner wall; 10. Water-cooled heat exchanger; 11. Air hole; 12. Air outlet; 13. Driving motor; 14. Transmission shaft. DETAILED DESCRIPTION

[0026] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0027] The technical solution of the present invention is described below by specific embodiments. It should be understood that one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combination step, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and does not limit the order of arrangement of each method or limit the scope of implementation of the present invention. The change or adjustment of the relative relationship thereof can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0028] According to a method for rapidly converting biomass to recover waste heat from blast furnace slag in a preferred embodiment of the present invention, granulated slag particles are mixed with biomass materials in a rotary cup granulator, and air is supplied upward to blow up the slag particles and biomass materials so that the two fully collide and contact, and the biomass materials absorb heat and convert to generate synthesis gas. The air supply method is pulsed. The pulse period is 1.5S, of which the air supply time is 0.5S and the intermittent time is 1S. The air supply pressure is 1-3Bar.

[0029] For the system or device used to implement the above method, reference may be made to one of the following implementations.

[0030] like Figure 1 to Figure 2 As shown, the device for rapidly converting biomass and recovering waste heat from blast furnace slag according to a preferred embodiment of the present invention includes a rotor 2 granulator.

[0031] The rotor 2 granulator is a prior art product, and its structure is briefly described as follows: it includes a cavity 1, a rotor 2, a slag feeding pipe 4, a base 3 and a driving device. The base 3 is arranged at the bottom center of the cavity 1, and is used to support the rotor 2. Usually, the base 3 has a cylindrical outer contour. The driving device includes a driving motor 13 and a transmission shaft 14. The driving motor 13 is arranged outside the cavity 1, and the transmission shaft 14 is penetrated in the base 3. The driving motor 13 drives the rotor 2 to rotate through the transmission shaft 14. The slag feeding pipe 4 runs through the cavity 1, and the pipe mouth located in the cavity 1 is aligned with the rotor 2, so that the slag can be poured onto the rotor 2. When the rotor 2 rotates, the slag will be thrown away and hit the inner wall of the cavity 1 under the action of centrifugal force, thereby cooling, solidifying and refining into numerous particles.

[0032] The improvement of this scheme is that: the top of the cavity 1 is provided with an air outlet 12. Multiple layers of annular spouted beds 9 are arranged in the cavity 1. The spouted bed 9 is located below the rotating cup 2. The spouted bed 9 includes a bottom wall 91, an outer wall 92 and an inner wall 93. A plurality of groups of pores 11 distributed at equal angles are arranged on the bottom wall 91. The setting requirement for the multiple layers of spouted beds 9 is that the outer diameter of each spouted bed 9 decreases layer by layer from top to bottom. The top of the outer wall 92 of the spouted bed 9 located in the lower layer abuts against the bottom of the spouted bed 9 located in the upper layer, the outer wall 92 of the spouted bed 9 in the uppermost layer is attached to and fixedly connected with the inner wall of the cavity 1, and the inner wall 93 of the spouted bed 9 in the lowermost layer is attached to and fixedly connected with the base 3. Preferably, the spouted bed 9 is arranged in two layers, and ten groups of pores 11 are arranged on the spouted bed 9, each group having six pores 11.

[0033] The cavity 1 is penetrated by a plurality of biomass feed pipes 5 and particle discharge pipes 6. The biomass feed pipes 5 are located above the uppermost spouted bed 9 and are used to add biomass materials. Biomass materials are organic matter produced by plants, animals, etc. through photosynthesis or other biological processes, and are considered to be a carbon-neutral renewable energy source.

[0034] The particle discharge pipe 6 is connected to the spouted bed 9 at the bottom. The particle discharge pipe 6 is tilted, with the outer side lower than the inner side, so that the material entering the particle discharge pipe 6 can slide out due to gravity.

[0035] A fan is provided outside the cavity 1, and the fan is connected to a plurality of air ducts 7, which are not shown in the attached drawings. The air ducts 7 extend into the cavity 1 and are used to blow air upward from the air holes 11. There are twenty groups of air holes 11, so twenty air ducts 7 are required. A solenoid valve 8 is provided on the air duct 7. The solenoid valve 8 realizes pulsed air supply by intermittent opening and closing. One pulse cycle is 1.5S. The air supply time is 0.5S, and the intermittent time is 1S. The air pressure of the air supply is 1-3Bar.

[0036] In addition, a water-cooled heat exchanger 10 is provided on the outer wall of the cavity 1. The water-cooled heat exchanger 10 is annular and covers the outer wall surface of the cavity 1, and is used to cool the inner wall of the cavity 1, thereby forming a water-cooled wall. The water-cooled heat exchanger 10 is located above the uppermost spouted bed 9, and the formed water-cooled wall can more effectively help cool the slag.

[0037] The specific implementation process is: first, molten slag is added to the rotor 2 through the slag feeding pipe 4, and then the rotor 2 rotates to throw the slag onto the inner wall of the cavity 1. When the slag hits the water-cooled wall, it will quickly cool down and be refined into many soybean-sized slag particles. The slag particles will fall into the spouted bed 9 on the top layer. At the same time, biomass materials are added through the biomass feeding pipe 5, and the biomass materials will also fall into the spouted bed 9 on the top layer. After the biomass materials come into contact with the high-temperature slag particles, they will quickly transform and generate synthesis gas. The synthesis gas is discharged from the gas outlet 12. Conversion is the process of pyrolysis and gasification of biomass materials. It is a thermochemical process of converting into combustible gas in a high-temperature, oxygen-deficient environment. Unlike combustion, this incomplete oxidation reaction can produce a gas mainly composed of carbon monoxide and hydrogen, namely synthesis gas. Synthesis gas is a valuable chemical raw material that can be used and produced by downstream enterprises in a variety of chemical products.

[0038] In order to make the slag particles and biomass materials fully contact, pulsed air supply is realized through the electromagnetic valve 8, so that the slag particles and biomass materials can be blown upward, and the blown slag particles and biomass materials collide with each other and fall, and then some of the slag particles and biomass materials will fall into the next layer of the spouted bed 9. The next layer of the spouted bed 9 will also supply air upward to blow the slag particles and biomass materials again, continue to contact and transform. In the process of blowing, the slag particles can be discharged after falling into the range of the nozzle of the particle discharge pipe 6. The temperature of the discharged slag particles can be lower than 200°C.

[0039] The process of supplying gas upward to blow the slag particles can effectively prevent the slag particles from sticking together. In this process, the slag particles are cooled and collided, so it does not affect the subsequent use of the slag particles as consumables. There are two other purposes for supplying gas in a pulsed manner. One is to prevent the slag particles from cooling too quickly so that the slag particles can transfer heat to the biomass material as much as possible; the other is to reduce the supply of oxygen in the cavity 1.

[0040] This solution uses a different approach to utilize the waste heat of the slag particles so that they can participate in the generation of synthesis gas. In addition, a significant advantage of this process is that almost no tar is produced. In the prior art, pyrolysis of biomass materials produces tar, but since the temperature of the slag particles when they contact the water-cooled wall and fall onto the spouted bed 9 can reach 1200-1300°C, this temperature will also complete the conversion of tar and integrate it into the synthesis gas, so almost no tar is produced. No tar production is a great advantage because tar can easily stick to the reactor.

[0041] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for rapidly converting biomass to recover waste heat from blast furnace slag, characterized in that: In the rotor granulator, the granulated slag particles are mixed with the biomass material, and air is supplied upward to blow the slag particles and the biomass material so that the two fully collide and contact, and the biomass material absorbs heat and is converted into synthesis gas.

2. The method for recovering blast furnace slag waste heat by rapid conversion of biomass according to claim 1 is characterized in that: The air supply method is pulse type.

3. The method for recovering blast furnace slag waste heat by rapid biomass conversion according to claim 2 is characterized in that: The pulse period is 1.5S, of which the air supply time is 0.5S and the intermittent time is 1S.

4. The method for recovering blast furnace slag waste heat by rapid biomass conversion according to claim 1 is characterized in that: The air supply pressure is 1-3Bar.

5. A device for rapidly converting biomass to recover waste heat from blast furnace slag, comprising a rotor granulator, the rotor granulator comprising a cavity, a rotor, a slag feeding pipe, a base and a driving device, characterized in that: The top of the cavity is provided with an air outlet; a plurality of layers of annular spouted beds are provided in the cavity, the spouted beds are located below the rotating cup, the spouted beds include a bottom wall, an outer wall and an inner wall, the bottom wall is provided with a plurality of groups of pores distributed at equal angles; the outer diameter of each of the spouted beds decreases layer by layer from top to bottom; the top of the outer wall of the spouted bed located in the lower layer abuts against the bottom of the spouted bed located in the upper layer, the outer wall of the spouted bed in the uppermost layer fits against the inner wall of the cavity, and the inner wall of the spouted bed in the lowermost layer fits against the base; The cavity is penetrated by a plurality of biomass feeding pipes and particle discharging pipes; the biomass feeding pipe is located above the spouted bed at the uppermost layer and is used to add biomass materials; the particle discharging pipe is connected to the spouted bed at the lowermost layer; A fan is arranged outside the cavity, and the fan is connected to a plurality of air ducts. The air ducts extend into the cavity and are used for blowing air upwards from the air holes.

6. The device for rapidly converting biomass to recover waste heat from blast furnace slag according to claim 5 is characterized in that: The outer wall of the cavity is provided with a water-cooled heat exchanger for cooling the inner wall of the cavity.

7. The device for rapidly converting biomass to recover waste heat from blast furnace slag according to claim 6 is characterized in that: The water-cooled heat exchanger is located above the uppermost spouted bed.

8. The device for rapidly converting biomass to recover waste heat from blast furnace slag according to claim 5 is characterized in that: The air duct is provided with a solenoid valve.

9. The device for rapidly converting biomass to recover waste heat from blast furnace slag according to claim 8, characterized in that: The solenoid valve realizes pulsed air supply by intermittent opening and closing.

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