CN116465219A - Device and method for producing pellets by adopting low-calorific-value gas - Google Patents
Device and method for producing pellets by adopting low-calorific-value gas Download PDFInfo
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- CN116465219A CN116465219A CN202310609071.0A CN202310609071A CN116465219A CN 116465219 A CN116465219 A CN 116465219A CN 202310609071 A CN202310609071 A CN 202310609071A CN 116465219 A CN116465219 A CN 116465219A
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- 239000008188 pellet Substances 0.000 title claims abstract description 60
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 238000001816 cooling Methods 0.000 claims abstract description 191
- 239000000446 fuel Substances 0.000 claims abstract description 77
- 238000001035 drying Methods 0.000 claims abstract description 58
- 238000002791 soaking Methods 0.000 claims abstract description 40
- 239000002737 fuel gas Substances 0.000 claims abstract description 25
- 239000002912 waste gas Substances 0.000 claims abstract description 19
- 239000007789 gas Substances 0.000 claims description 68
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 33
- 239000003546 flue gas Substances 0.000 claims description 33
- 238000002485 combustion reaction Methods 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 14
- 230000001172 regenerating effect Effects 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 238000006477 desulfuration reaction Methods 0.000 claims description 7
- 230000023556 desulfurization Effects 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 238000001354 calcination Methods 0.000 claims description 6
- 239000000428 dust Substances 0.000 claims description 3
- 206010010904 Convulsion Diseases 0.000 claims description 2
- 230000036461 convulsion Effects 0.000 claims description 2
- 238000011084 recovery Methods 0.000 claims 5
- 238000007596 consolidation process Methods 0.000 abstract description 4
- 238000012545 processing Methods 0.000 abstract description 4
- 239000003570 air Substances 0.000 description 134
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 8
- 230000001276 controlling effect Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000007605 air drying Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000000571 coke Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000003345 natural gas Substances 0.000 description 4
- 238000005192 partition Methods 0.000 description 3
- 239000012080 ambient air Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/16—Sintering; Agglomerating
- C22B1/212—Sintering; Agglomerating in tunnel furnaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/004—Nozzle assemblies; Air knives; Air distributors; Blow boxes
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Drying Of Solid Materials (AREA)
Abstract
The invention discloses a device for producing pellets by adopting low-heat-value fuel gas, which comprises an air blast drying section, an air draft drying section, a preheating section, a roasting section, a soaking section and a cooling section which are sequentially arranged in a separated mode, wherein the cooling section is divided into a cooling first section, a cooling second section and a cooling third section which are sequentially arranged, the cooling first section is arranged close to the soaking section, waste gas of the soaking section is communicated with a first air box of the cooling first section through a first pipeline, the first air box is communicated with a cooling pipeline, hot air of the cooling first section flows to the roasting section and the soaking section, a first low-heat-value fuel burner is arranged in the roasting section, and the air-fuel ratio of the first low-heat-value fuel burner is 4-7. The device for producing pellets by using low-heat-value fuel gas can realize high-temperature roasting and consolidation of pellets by using the low-heat-value fuel, and reduce the processing cost of pellets. The invention also provides a method for producing pellets by adopting the low-calorific-value fuel gas.
Description
Technical Field
The invention relates to the technical field of pellet production, in particular to a device and a method for producing pellets by adopting low-calorific-value fuel gas.
Background
Pellets are mainly applied to iron-making production as high-quality iron-containing raw materials, and are increasingly favored by iron and steel enterprises due to the characteristics of low energy consumption and environmental protection. In pellet production, the belt roasting machine has strong production capacity, so that the belt roasting machine is main stream equipment for producing pellets, and can efficiently prepare various green products such as acid pellets, fluxed pellets and the like with good technical and economic indexes. When pellets are produced in a belt roasting machine, the drying, preheating, roasting, soaking and cooling processes are sequentially completed, so that the belt roasting machine is subjected to process segmentation according to different functions, and the belt roasting machine is generally divided into seven process segments of an air blast drying segment, an air draft drying segment, a preheating segment, a roasting segment, a soaking segment, a cooling segment and a cooling segment in the prior art.
In the prior art, pellets produced by a belt type roasting machine are required to be dried, preheated, heated and roasted for heat supply by high-heat-value gas combustion, and coke oven gas or natural gas is usually adopted. The cooling section of the existing belt roasting machine is divided into a cooling section and a cooling section, wherein normal-temperature air is blown into the cooling section to cool the pellets, and generated high-temperature flue gas mainly passes through the preheating section and the roasting section to carry out heat circulation, the temperature is generally 800-950 ℃, and high-heat-value fuel gas, which is generally coke oven gas or natural gas, is mainly used for combustion. The air-fuel ratio of the coke oven gas or the natural gas combustion reaction is too high due to the excessive gas quantity of the cooling section and is generally in the range of 8-12, so that the heat generated by combustion heats excessive flue gas quantity to cause energy waste. Meanwhile, common metallurgical gas such as blast furnace gas, converter gas and other low-heat-value fuels cannot meet the requirements of roasting temperature due to low calorific value of the fuel, insufficient heat supply and failure to realize high-temperature roasting and consolidation of pellets. Thus, depending on high heating value natural gas or coke oven gas, the pellet processing cost increases.
Disclosure of Invention
In view of the above, the invention provides a device for producing pellets by using low-calorific-value fuel gas, which can realize high-temperature roasting and consolidation of pellets by using low-calorific-value fuel in a mode of cooling by hot air and reducing combustion air-fuel ratio, thereby reducing the processing cost of pellets.
The invention also provides a method for producing pellets by adopting the low-calorific-value fuel gas.
In order to achieve the above purpose, the present invention provides the following technical solutions:
the utility model provides an adopt device of low calorific value gas production pellet, includes the blast drying section, convulsions drying section, preheating section, calcination section, soaking section and the cooling section that separate in proper order and set up, its characterized in that, the cooling section separates into cooling one section, cooling two sections and the cooling three sections that set gradually, cooling one section is close to the soaking section sets up, the waste gas of soaking section with cooling one section's first bellows intercommunication through first pipeline, first bellows and cooling pipeline intercommunication, cooling pipeline is used for to cooling one section carries the normal atmospheric temperature air of setting quantity, cooling one section's hot-blast flow direction calcination section and soaking section, calcination section is provided with first low calorific value fuel nozzle, cooling one section's hot flue gas is first low calorific value fuel nozzle provides the oxygen that the burning needs, first low calorific value fuel nozzle's fuel is low calorific value gas, and first low calorific value fuel nozzle's air-fuel ratio is 4-7.
Optionally, the air inlet end of the cooling second section is provided with a second air box, the second air box is communicated with the cooling pipeline, the cooling pipeline is used for conveying normal-temperature air to the cooling second section, and the hot air heated by the cooling second section is communicated with one end, close to the roasting section, of the preheating section through the second pipeline;
the hot waste gas generated by the roasting section is communicated with one end of the preheating section, which is close to the air draft drying section, through a heat return pipeline;
a regenerative fan is arranged on the regenerative pipeline;
and a cooling fan is arranged on the cooling pipeline.
Optionally, one end of the heat return pipeline, which is far away from the roasting section, comprises a first heat return branch pipe and a second heat return branch pipe, wherein the first heat return branch pipe is communicated with the preheating section, and the second heat return branch pipe is communicated with the air draft drying section.
Optionally, the exhaust gas of the exhaust drying section and the preheating section is communicated with desulfurization and denitrification equipment through a third pipeline, and the exhaust gas of the third pipeline is discharged after being treated by the desulfurization and denitrification equipment;
and a main exhaust fan is arranged on the third pipeline.
Optionally, a fourth air box is arranged at the exhaust ends of the exhaust drying section and the preheating section, exhaust gas of the exhaust drying section and the preheating section is discharged to the fourth air box, and the third pipeline is communicated with the fourth air box;
the fourth air box is communicated with a fifth air box at the exhaust gas end of the roasting section through a fourth pipeline, and a first valve is arranged on the fourth pipeline.
Optionally, a second low-heating-value fuel burner is arranged at one end, close to the roasting section, of the preheating section;
and the hot air of the cooling second section provides oxygen required by combustion for the second low-heat-value fuel burner, and the fuel of the second low-heat-value fuel burner is low-heat-value fuel gas.
Optionally, the air outlet end of the cooling three sections is communicated with the air inlet of the forced air drying section through a fifth pipeline, and the flue gas at the outlet end of the forced air drying section is discharged after dust removal;
and a drum dryer is arranged on the fifth pipeline.
According to the device for producing pellets by using low-heat-value fuel gas, hot air in the soaking section is introduced into the first air box at the air inlet position of the cooling section, the hot air flowing into the soaking section is mixed with air flowing into the first air box through the cooling pipeline in the first air box, the cooling section is cooled by hot air after being mixed with waste gas and normal-temperature air of the soaking section, and the temperature of flue gas discharged from the cooling section is increased. The cooling section is divided into three sections, so that the cooling air quantity entering the cooling section is reduced, the air quantity required to be heated is reduced, and the temperature of the flue gas for cooling the section is further increased. Compared with the prior art that normal-temperature air cooling is directly adopted, the cooling section of the device for producing pellets by using low-heat-value fuel gas adopts high-temperature cooling, and the temperature of the air for cooling the cooling section is increased to 950-1150 ℃ from 800-950 ℃ in the prior art, so that the heat required to be supplemented for meeting the temperature of a roasting section is reduced, the requirement can be met by using the low-heat-value fuel gas as fuel, and the air-fuel ratio of the first low-heat-value fuel burner is set to 4-7, so that the requirement can be met.
The invention also provides a method for producing pellets by using the low-heat-value gas, which is applied to the device for producing pellets by using the low-heat-value gas, and comprises the steps of mixing waste gas of a soaking section with normal-temperature air with a set amount, then carrying out hot air cooling on a cooling section, controlling the temperature of hot flue gas of the cooling section to 950-1150 ℃, and providing high-temperature air required by combustion for the first low-heat-value fuel burner by the hot flue gas of the cooling section;
and controlling the quantity of the hot flue gas and the low-heat value gas entering the cooling section of the first low-heat value fuel burner according to the temperature requirement to enable the air-fuel ratio of the first low-heat value fuel burner to be 4-7.
Optionally, the hot exhaust gas generated by the roasting section is used for heating the induced draft drying section and the preheating section, and the hot air of the cooling two sections is used for heating the preheating section;
and heating and drying the blast drying section by using hot air for cooling the three sections.
Alternatively, the air temperature of the induced draft drying section and the preheating section is controlled by controlling the amount of hot exhaust gas generated by the roasting section entering the induced draft drying section and the preheating section.
The method for producing pellets by using low-heat-value gas is applied to the device for producing pellets by using low-heat-value gas, so that the device has the advantages of the structure and is not repeated here.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of an apparatus for producing pellets using low calorific value gas according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a roasting section, a soaking section and a cooling section according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a roasting section, a soaking section and a cooling section according to another embodiment of the present invention;
FIG. 4 is a schematic structural diagram of an induced draft drying section, a preheating section and a roasting section according to an embodiment of the present invention;
FIG. 5 is a schematic structural view of an apparatus for producing pellets using low calorific value gas according to another embodiment of the present invention;
fig. 6 is a schematic structural view of the induced draft drying section, the preheating section and the roasting section in fig. 5.
Wherein:
1. the device comprises a blast drying section, 2, an induced draft drying section, 3, a preheating section, 4, a roasting section, 5, a cooling first section, 6, a cooling second section, 7, a cooling third section, 8, a third air box, 9, a second air box, 10, a first air box, 11, a first pipeline, 12, a soaking section, 13, a cooling pipeline, 14, a second backheating branch pipe, 15, a first backheating branch pipe, 16, a backheating pipeline, 17, a secondary air main pipe, 18, a second pipeline, 19, a fifth pipeline, 20, a backheating fan, 21, a main exhaust fan, 22, a third pipeline, 23, a blast drying fan, 24, a distributing device, 25, a chimney, 26, a second valve, 27, a fourth pipeline, 28, a first valve, 29 and a cooling fan.
Detailed Description
The invention discloses a device for producing pellets by adopting low-heat-value fuel gas, which can realize high-temperature roasting and consolidation of pellets by adopting the low-heat-value fuel in a mode of adopting hot air for cooling and reducing the combustion air-fuel ratio, thereby reducing the processing cost of the pellets.
The invention also discloses a method for producing pellets by adopting the low-calorific-value fuel gas.
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1 to 6, the apparatus for producing pellets using low calorific value gas according to the present invention includes a blast drying section 1, an induced draft drying section 2, a preheating section 3, a roasting section 4, a soaking section 12, and a cooling section which are disposed to be spaced apart in sequence along a conveying direction. The cooling section is divided into a cooling first section 5, a cooling second section 6 and a cooling third section 7 which are sequentially arranged, the cooling first section 5 is arranged close to a soaking section 12, waste gas of the soaking section 12 is communicated with a first bellows 10 of the cooling first section 5 through a first pipeline 11, the first bellows 10 is communicated with a cooling pipeline 13, the cooling pipeline 13 is used for conveying normal-temperature air with a set quantity to the cooling first section 5, hot air of the cooling first section 5 flows to a roasting section 4 and the soaking section 12, the roasting section 4 is provided with a first low-heat-value fuel burner, hot flue gas of the cooling first section 5 is oxygen required by combustion provided for the first low-heat-value fuel burner, fuel of the first low-heat-value fuel burner is low-heat-value fuel, and the air-fuel ratio of the first low-heat-value fuel burner is 4-7.
The air-fuel ratio refers to the ratio of the actual combustion air amount to the air amount required for complete combustion of the fuel gas. The chambers of the forced air drying section 1, the induced draft drying section 2, the preheating section 3, the roasting section 4, the soaking section 12 and the cooling section are separated by partition walls. The total length of the cooling section is the same as that of the prior art belt roasting machine. The total length of the cooling first section 5 and the cooling second section 6 according to the invention is the same as the length of the cooling first section of the prior art belt calciner, whereas the total amount of cooling air fed into said cooling sections by the cooling circuit 13 is unchanged, whereby the amount of cooling air entering the first windbox 10 of the cooling first section 5 is reduced. The first air box 10 is communicated with the air inlet side of the cooling first section 5, the second air box 9 is communicated with the air inlet side of the cooling second section 6, the third air box 8 is communicated with the air inlet side of the cooling third section 7, and the first air box 10, the second air box 9 and the third air box 8 are all communicated with the cooling pipeline 13. The distributing device 24 conveys the pellets onto a conveyor of the belt roasting machine. In order to adjust the flame size of the first low-heat-value fuel burner, a combustion air inlet is further formed in the first low-heat-value fuel burner and used for supplementing a small amount of combustion air. Solid arrows in the figure represent the flow direction of the gas, and dashed arrows represent the direction of rotation of the conveyor.
According to the device for producing pellets by using low-calorific-value fuel gas, hot air in the soaking section 12 is introduced into the first air box 10 at the air inlet position of the cooling section 5, the hot air flowing into the soaking section 12 is mixed with air flowing into the first air box 10 through the cooling pipeline 13 in the first air box 10, the cooling section 5 is cooled by hot air after being mixed by waste gas of the soaking section 12 and normal-temperature air, and the temperature of flue gas discharged from the cooling section is increased. Dividing the cooling section into three sections reduces the amount of cooling air entering the cooling section 5, thereby reducing the amount of air to be heated and further increasing the temperature of the flue gas cooling section 5. Compared with the prior art that normal-temperature air cooling is directly adopted, the cooling first section 5 of the device for producing pellets by using low-heat-value fuel gas adopts high-temperature cooling, and the temperature of the air for cooling the first section 5 is increased to 950-1150 ℃ from 800-950 ℃ in the prior art, so that the heat value required to be supplemented for meeting the temperature of the roasting section 4 is reduced, the requirement can be met by using the low-heat-value fuel gas as fuel, and the air-fuel ratio of the first low-heat-value fuel burner is set to 4-7.
For supplying cooling air to the cooling section, a cooling fan 29 is arranged on the cooling line 13. The cooling fan 29 supplies cooling air at normal temperature to the cooling section as needed. The air inlet end of the cooling second section 6 is communicated with a cooling pipeline 13 through a second air box 9, the cooling pipeline 13 is used for conveying normal-temperature air to the cooling second section 6, and the hot air heated by the cooling second section 6 is communicated with one end, close to the roasting section 4, of the preheating section 3 through a second pipeline 18. The hot exhaust gas generated by the roasting section 4 is communicated with one end of the preheating section 3, which is close to the induced draft drying section 2, through a backheating pipeline 16. The flue gas temperature of the cooling second section 6 is between 500 and 850 ℃, and is introduced into the rear part of the preheating section 3, and part of the flue gas is mixed with the hot waste gas formed by the roasting section 4 and is introduced into the front part of the preheating section 3. The rear part here means the region that arrives after the conveyor of the belt roasting machine in the conveying direction, and the front part means the region that arrives first in the conveying direction of the conveyor of the belt roasting machine. In order to smoothly convey the hot exhaust gas generated in the roasting section 4 to the preheating section 3, a regenerative fan 20 is arranged on the regenerative pipeline 16.
In an embodiment, one end of the heat return pipeline 16 far away from the roasting section 4 comprises a first heat return branch pipe 15 and a second heat return branch pipe 14, the first heat return branch pipe 15 is communicated with the preheating section 3, and the second heat return branch pipe 14 is communicated with the induced draft drying section 2, so that a part of hot waste gas generated by the roasting section 4 flows to the inner cavity of the preheating section 3 through the first heat return branch pipe 15, and another part of generated waste gas flows to the inner cavity of the induced draft drying section 2 through the second heat return branch pipe 14 to serve as a medium for induced draft drying of pellets in the induced draft drying section 2.
In order to avoid pollution of exhaust gas to air, the exhaust gas of the exhaust drying section 2 and the preheating section 3 is collected in the fourth air box and then communicated with the desulfurization and denitrification equipment and the dust removal equipment through the third pipeline 22, and the exhaust gas of the third pipeline 22 is discharged after being treated by the desulfurization and denitrification equipment. It will be appreciated that the desulfurization and denitrification facility and the dedusting facility are disposed within the stack 25. In order to facilitate the discharge of the exhaust gases from the induced-draft drying section 2 and the preheating section 3, a main blower 21 is arranged on the third line 22.
The exhaust ends of the exhausting drying section 2 and the preheating section 3 are provided with a fourth air box, exhaust gases of the exhausting drying section 2 and the preheating section 3 are discharged to the fourth air box, and a third pipeline 22 is communicated with the fourth air box. In order to control the air temperature of the induced draft drying section 2 and the preheating section 3 to be in a reasonable range, the fourth air box is communicated with a fifth air box at the exhaust gas end of the roasting section 4 through a fourth pipeline 27, a first valve 28 is arranged on the fourth pipeline 27, and the opening degree of the first valve 28 is controlled to control the hot air quantity entering the fourth air box through the fourth pipeline 27, as shown in fig. 5 and 6.
In order to improve the temperature of the rear part of the preheating section 3, one end, close to the roasting section 4, of the preheating section 3 is provided with a second low-heat-value fuel burner, hot air of the cooling second section 6 is communicated with an air connection port of the second low-heat-value fuel burner, the hot air of the cooling second section provides oxygen required by combustion for the second low-heat-value fuel burner, the requirement on a heating range is reduced, the temperature requirement can be met by using low-heat-value fuel gas, and the fuel of the second low-heat-value fuel burner is the low-heat-value fuel gas. And the second low-heat-value fuel burner is arranged to burn the low-heat-value fuel gas, so that the rear temperature of the preheating section 3 is increased.
Further, the air outlet end of the cooling three section 7 is communicated with the air inlet of the forced air drying section 1 through a fifth pipeline 19, and the flue gas at the outlet end of the forced air drying section 1 is discharged after being dedusted by a dedusting device in a chimney 25. In order to make the hot waste gas in the cooling three section 7 smoothly enter the blast drying section 1 to dry the pellets, a blast drying fan 23 is arranged on the fifth pipeline 19. The cooling fan 29 blows ambient air into the belt roasting machine, passes through the material layer from bottom to top, and cools the pellets.
In order to facilitate the adjustment of the amount of cooling air introduced into the first windbox 10, a second valve 26 is provided in the line of the first windbox 10 communicating with the cooling line 13, as shown in FIG. 3.
The device for producing pellets by adopting low-calorific-value fuel gas is divided into three sections, partition walls are arranged between each two sections, hot air for cooling the first section 5 flows into the roasting section 4 and the soaking section 12 through a secondary air main pipe 17 and a descending pipe, hot air for cooling the second section 6 is fed into the preheating section 3, and hot air for cooling the third section 7 is fed into the blast drying section 2. The waste gas of the roasting section 4 is used as the back-heating air, and is fed into the front parts of the air draft drying section 2 and the preheating section 3 through the back-heating fan 20. The cooling section 5 is cooled by hot air after mixing the waste gas of the soaking section 12 and normal-temperature air, the temperature of the flue gas of the cooling section 5 is increased to 950-1150 ℃, and the air quantity of the normal-temperature air is controlled to be within 4-7. The temperature of the hot flue gas for cooling the second section 6 is 500-850 ℃.
The hot air at the front part of the preheating section 3 has two sources, the main source is the regenerative air exhausted by the regenerative fan 20, and then part of hot air of the partial cooling second section 6 is introduced, and the front area of the preheating section 3 is regulated to form a proper temperature gradient. The hot air source at the rear part of the preheating section 3 is mainly a cooling second section 6, and the second low-heat value fuel burner is arranged for burning and supplying heat according to production requirements.
The partition walls of the soaking section 12 and the cooling section 5 are provided with communication holes, so that the soaking section 12 and the cooling section 5 are communicated. The hot air of the roasting section 4 and the soaking section 12 comes from the cooling first section 5, and enters the roasting section 4 through the descending pipes after entering the secondary air main pipe 17, wherein the descending pipes are symmetrically distributed on two sides of the secondary air main pipe 17, and the first low-heat-value fuel burner is arranged on the descending pipes. The hot exhaust gas from the soaking section 12 is re-blown into the cooling section 5 for hot air cooling. The cold air for cooling the first section 5, the second section 6 and the third section 7 is all from the ambient air blown by the cooling fan 29.
In one embodiment, the low heating value gas is converter gas. The cooling section 5 is cooled by hot air after the hot waste gas of the soaking section 12 and normal-temperature air are mixed, the flue gas temperature of the cooling section is increased to 1050 ℃, the flue gas quantity is calculated according to the composition of converter gas and controlled to enable the air-fuel ratio to be 5, and under the operating condition, the flue gas temperature of the roasting section 4 can reach 1250 ℃, so that the magnetite production requirement is met.
The device for producing pellets by adopting the low-calorific-value fuel gas can adopt the low-calorific-value fuel to produce by adopting the hot air cooling and combustion air-fuel ratio reducing modes, and further reduces the energy consumption of working procedures.
The invention also provides a method for producing pellets by using the low-heat-value gas, which is applied to the device for producing pellets by using the low-heat-value gas, and the hot exhaust gas of the soaking section 12 is mixed with a set amount of normal-temperature air to cool the cooling section 5 by hot air, the temperature of the hot flue gas of the cooling section 5 is controlled to 950-1150 ℃, and the hot flue gas of the cooling section 5 provides high-temperature air required by combustion for the first low-heat-value fuel burner. And controlling the quantity of the hot flue gas and the low-heat value gas entering the cooling section of the first low-heat value fuel burner according to the temperature requirement to enable the air-fuel ratio of the first low-heat value fuel burner to be 4-7. And according to the temperature requirement of the process section, controlling and finely adjusting the consumption of the hot flue gas and the low-heat-value fuel gas entering the first low-heat-value fuel burner through a valve to enable the air-fuel ratio of the first low-heat-value fuel burner to be 4-7.
In order to fully utilize the heat of the production process, the hot waste gas generated by the roasting section 4 heats the induced draft drying section 2 and the preheating section 3, the hot air of the cooling second section 6 is utilized to heat the preheating section 3, and the hot air of the cooling third section 7 is utilized to heat and dry the blast drying section 1. In order to meet the heat requirements of the induced draft drying section 2 and the preheating section 3, the air temperature of the induced draft drying section 2 and the preheating section 3 is controlled by controlling the amount of hot exhaust gas generated by the roasting section 4 entering the induced draft drying section 2 and the preheating section 3.
The invention also provides a method for producing pellets by adopting low-calorific-value fuel gas, hot waste gas of the soaking section 12 flows into the cooling section 5 for hot air cooling, the temperature of flue gas of the cooling section 5 can be raised to 950-1150 ℃, and meanwhile, the cooling section in the prior art is subdivided into three sections, compared with the cooling section in the prior art, the cooling section is divided into two sections, and the length of the cooling section 5 is smaller than that of the cooling section in the prior art because the total length of the cooling section is unchanged, so that the air quantity entering the cooling section 5 in the invention is reduced relative to that of the cooling section in the prior art, and the air quantity to be heated is reduced. Because the flue gas temperature of the cooling first section 5 is already heated by the hot exhaust gas of the soaking section 12, the temperature of the flue gas flowing out of the cooling first section 5 is increased, so that the temperature of the hot flue gas flowing out of the cooling first section 5 is closer to the required temperature of the roasting section 4, that is, the required temperature of the roasting section 4 (1250 ℃), the required temperature to be increased is reduced, and the requirement can be met by using low-calorific-value fuel. The combustion air-fuel ratio is reduced from 8-12 to 4-7, thus being capable of meeting the application of low-calorific-value fuels such as converter gas and the like in the pellet process of the belt roasting machine. The hot air with the temperature of 500-850 ℃ formed by the cooling second section 6 is led to the preheating section 3, and the low-heating-value fuel can be used for supplying heat while the proper temperature is formed. The ideal temperature is regulated and controlled by the main hot air and the backheating air after the main hot air and the backheating air are mixed in the exhaust drying section 2 and the preheating section 3, and meanwhile, the circulation of the main hot air and the backheating air reduces the exhaust smoke quantity and the oxygen content of the smoke, so that the pollutant discharge load is reduced.
In the description of the present embodiment, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "vertical", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present embodiment.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present embodiment, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The utility model provides an adopt device of low calorific value gas production pellet, includes the blast drying section, convulsions drying section, preheating section, calcination section, soaking section and the cooling section that separate in proper order and set up, its characterized in that, the cooling section separates into cooling one section, cooling two sections and the cooling three sections that set gradually, cooling one section is close to the soaking section sets up, the waste gas of soaking section with cooling one section's first bellows intercommunication through first pipeline, first bellows and cooling pipeline intercommunication, cooling pipeline is used for to cooling one section carries the normal atmospheric temperature air of setting quantity, cooling one section's hot-blast flow direction calcination section and soaking section, calcination section is provided with first low calorific value fuel nozzle, cooling one section's hot flue gas is first low calorific value fuel nozzle provides the oxygen that the burning needs, first low calorific value fuel nozzle's fuel is low calorific value gas, and first low calorific value fuel nozzle's air-fuel ratio is 4-7.
2. The apparatus for producing pellets using low calorific value gas as claimed in claim 1, wherein an air inlet end of the cooling second section is provided with a second air box, the second air box is communicated with the cooling pipeline, the cooling pipeline is used for conveying normal temperature air to the cooling second section, and the hot air heated by the cooling second section is communicated with one end of the preheating section, which is close to the roasting section, through the second pipeline;
the hot waste gas generated by the roasting section is communicated with one end of the preheating section, which is close to the air draft drying section, through a heat return pipeline;
a regenerative fan is arranged on the regenerative pipeline;
and a cooling fan is arranged on the cooling pipeline.
3. The apparatus for producing pellets using low heating value gas as claimed in claim 2, wherein the end of the heat recovery line remote from the roasting section includes a first heat recovery branch pipe and a second heat recovery branch pipe, the first heat recovery branch pipe is communicated with the preheating section, and the second heat recovery branch pipe is communicated with the air draft drying section.
4. The apparatus for producing pellets using low heating value gas as claimed in claim 3, wherein the exhaust gas of the exhaust drying section and the preheating section is communicated with the desulfurization and denitrification device through a third pipeline, and the exhaust gas of the third pipeline is discharged after being treated by the desulfurization and denitrification device;
and a main exhaust fan is arranged on the third pipeline.
5. The apparatus for producing pellets using low calorific value gas as claimed in claim 4, wherein a fourth bellows is provided at exhaust gas ends of the suction drying section and the preheating section, exhaust gas of both is discharged to the fourth bellows, and the third pipeline is communicated with the fourth bellows;
the fourth air box is communicated with a fifth air box at the exhaust gas end of the roasting section through a fourth pipeline, and a first valve is arranged on the fourth pipeline.
6. The apparatus for producing pellets using low calorific value gas as claimed in claim 2, wherein a second low calorific value fuel burner is provided at one end of the preheating section near the roasting section;
and the hot air of the cooling second section provides oxygen required by combustion for the second low-heat-value fuel burner, and the fuel of the second low-heat-value fuel burner is low-heat-value fuel gas.
7. The apparatus for producing pellets using low calorific value gas as claimed in claim 1, wherein the gas outlet end of the cooling three section is communicated with the gas inlet of the blast drying section through a fifth pipeline, and the flue gas at the outlet end of the blast drying section is discharged after dust removal;
and a drum dryer is arranged on the fifth pipeline.
8. A method for producing pellets by using low-heat value gas, which is applied to the device for producing pellets by using low-heat value gas according to any one of claims 1-7, and is characterized in that the waste gas of a soaking section is mixed with a set amount of normal-temperature air to cool the cooling section by hot air, the temperature of hot flue gas of the cooling section is controlled to 950-1150 ℃, and the hot flue gas of the cooling section provides high-temperature air required by combustion for the first low-heat value fuel burner;
and controlling the quantity of the hot flue gas and the low-heat value gas entering the cooling section of the first low-heat value fuel burner according to the temperature requirement to enable the air-fuel ratio of the first low-heat value fuel burner to be 4-7.
9. The method for producing pellets using low calorific value gas according to claim 8, wherein the hot exhaust gas generated from the roasting section is used to heat the induced draft drying section and the preheating section, and the hot air of the cooling two sections is used to heat the preheating section;
and heating and drying the blast drying section by using hot air for cooling the three sections.
10. The method for producing pellets using low heating value gas according to claim 8, wherein the wind temperature of the induced draft drying section and the preheating section is controlled by controlling the amount of hot exhaust gas generated from the roasting section entering the induced draft drying section and the preheating section.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310609071.0A CN116465219A (en) | 2023-05-26 | 2023-05-26 | Device and method for producing pellets by adopting low-calorific-value gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310609071.0A CN116465219A (en) | 2023-05-26 | 2023-05-26 | Device and method for producing pellets by adopting low-calorific-value gas |
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| Publication Number | Publication Date |
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| CN116465219A true CN116465219A (en) | 2023-07-21 |
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| CN202310609071.0A Pending CN116465219A (en) | 2023-05-26 | 2023-05-26 | Device and method for producing pellets by adopting low-calorific-value gas |
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| Country | Link |
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| CN (1) | CN116465219A (en) |
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2023
- 2023-05-26 CN CN202310609071.0A patent/CN116465219A/en active Pending
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