CN112481438A - Blast furnace hot blast stove double-preheating system with low-temperature corrosion resistant core - Google Patents
Blast furnace hot blast stove double-preheating system with low-temperature corrosion resistant core Download PDFInfo
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- CN112481438A CN112481438A CN202011312971.1A CN202011312971A CN112481438A CN 112481438 A CN112481438 A CN 112481438A CN 202011312971 A CN202011312971 A CN 202011312971A CN 112481438 A CN112481438 A CN 112481438A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
- C21B9/14—Preheating the combustion air
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Abstract
The invention relates to a double preheating system of a blast furnace hot blast stove with a low-temperature corrosion resistant core, belonging to the technical field of blast furnace hot blast stoves; the low-temperature section heat exchange module comprises a frame and a low-temperature corrosion resistant core body; the low-temperature corrosion resistant core body comprises a plurality of superposed plate pairs, each plate pair comprises symmetrically superposed plates, and independent gas channels are formed between the plates; the static air shield is arranged in a triangular area of the low-temperature section heat exchange module; the static air shield is designed at the part of the heat exchange core body of the low-temperature section heat exchange module which is coldest and most easy to form dew point corrosion, so that the preheating system has the advantages of high heat exchange efficiency, compact structure, long service life, difficulty in dust accumulation, easiness in cleaning, free module combination and the like, and the low-temperature dew point corrosion is prevented under the condition of relatively low cost.
Description
Technical Field
The invention relates to a double-preheating system of a blast furnace hot blast stove with a low-temperature corrosion resistant core, belonging to the technical field of blast furnace hot blast stoves.
Background
With the development of blast furnace iron-making technology, the improvement of air temperature and coke saving and yield increase become important subjects. In order to solve the problem, the theoretical combustion temperature of the fuel of the hot blast stove is increased and the air temperature is increased by utilizing the air and gas double preheating technology, so that the aims of saving energy, reducing consumption and reducing iron-making cost are fulfilled. The plate heat exchanger has the advantages of high heat exchange efficiency, compact structure, long service life, difficult dust accumulation, easy cleaning, free module combination and the like, and is gradually applied to blast furnace ironmaking. The plate heat exchanger is applied to an air/gas double preheating system, and low-temperature corrosion is an important problem which needs to be considered.
The metal corrosion speed is mainly influenced by three factors of the acid amount of condensation, the concentration of acid dew and the wall temperature of metal. When the wall temperature is higher and is slightly lower than the dew point, the amount of acid condensed on the wall surface is small, and the corrosion speed is slow. As the wall temperature decreases, the amount of condensed acid increases and the corrosion rate increases significantly. Typically, the wall temperature of the maximum corrosion point is about 20-45 ℃ lower than the dew point. When the wall temperature is further lowered, the amount of condensed acid is sufficient, and the corrosion rate is almost independent of the acid concentration and depends only on the metal wall temperature. As the wall temperature decreases, the acid concentration in the acid distillate also decreases. Although the decrease in the acid concentration in the acid dew increases the etching rate, the wall temperature has a greater influence on the etching rate than the acid concentration, and therefore the etching rate decreases. After the temperature is reduced to a certain degree, the influence of the concentration exceeds the influence of the wall temperature, and the corrosion speed is accelerated along with the reduction of the wall temperature.
The measures for avoiding dew point corrosion by the above analysis can be realized by flue gas desulfurization, increasing the grade of corrosion-resistant materials of the plate, increasing the temperature of a flue gas outlet and increasing the temperature of a metal wall to be above the dew point temperature. However, the flue gas components of the iron works are complex and greatly changed, and the flue gas desulfurization cost is high and is not easy to realize. The improvement of the grade of the corrosion-resistant material of the plate is limited in the application range of the material on one hand and increased in the cost on the other hand. The increase of the temperature of the flue gas outlet is equivalent to the loss of energy, and the heat exchange efficiency is reduced.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the defects of the prior art are overcome, the double preheating system of the blast furnace hot blast stove with the low-temperature corrosion resistant core body is provided, and low-temperature dew point corrosion is prevented.
The invention relates to a blast furnace hot blast stove double preheating system with a low-temperature corrosion resistant core, which comprises a high-temperature section heat exchange module and a low-temperature section heat exchange module, wherein the low-temperature section heat exchange module comprises a frame and a low-temperature corrosion resistant core; the low-temperature corrosion resistant core body comprises a plurality of superposed plate pairs, each plate pair comprises symmetrically superposed plates, and independent gas channels are formed between the plates; the static air shield is arranged in a triangular area of the low-temperature section heat exchange module.
The static gas screen does not conduct heat or convect and has a heat preservation effect, so that the temperature of the plate is kept above the dew point temperature in the heat exchange process to avoid low-temperature dew point corrosion. A static air shield is arranged in a coldest triangular area which is most prone to low-temperature corrosion on the low-temperature section heat exchange module, and the heat preservation effect of the static air shield enables the temperature of the plate to be kept above the dew point temperature in the heat exchange process so as to avoid low-temperature dew point corrosion.
Preferably, the spacing of the static air curtains is 2-5 mm.
Further enhancing the heat preservation effect.
Preferably, the static air shield is formed by sealing a metal plate and the plate, the metal plate is triangular, and the metal plate is made of a corrosion-resistant material.
The low-temperature corrosion area is triangular, so that the metal plate is triangular and consistent with the low-temperature corrosion area, the low-temperature dew point corrosion of the low-temperature corrosion area is prevented, and materials are saved.
Preferably, distance posts or support bars are arranged between the metal plate and the plate.
For adjusting the spacing of the static air curtains.
Preferably, the plate is embossed with bumps.
For adjusting the spacing of the static air curtains.
Preferably, the corrosion resistant material comprises one or more of austenitic stainless steel, duplex stainless steel, ND steel.
Further enhancing the corrosion resistance.
Preferably, the sheet and the sheet metal edges are sealed by a self-fluxing weld or a sealing weld.
Prevent that the air from flowing along with the heat exchange main airflow and not reaching the heat preservation effect, and on the other hand, can also prevent that the static gas shield mixed with the gas from corroding the plate.
Preferably, the system further comprises a flue gas inlet reducing device, a purging system, an air/coal gas outlet reducing device, an air/coal gas inlet reducing device, a flue gas outlet reducing device, a cross-over air channel and an inspection manhole, wherein the flue gas inlet reducing device, the air/coal gas outlet reducing device, the air/coal gas inlet reducing device, the flue gas outlet reducing device and the cross-over air channel are arranged on the periphery of the high-temperature section heat exchange module and the low-temperature section heat exchange module, and the inspection manhole is arranged on the flue gas inlet reducing device, the air/coal gas outlet reducing device, the air/coal gas inlet reducing device, the flue gas outlet.
The plate heat exchanger keeps the advantages of high heat exchange efficiency, compact structure, long service life, difficult dust accumulation, easy cleaning and free module combination, and further prevents the low-temperature dew point corrosion through the heat preservation effect of the low-cost static gas screen.
Preferably, a flue gas channel is formed between adjacent plate pairs, an air/gas side channel is formed between the symmetrically stacked plate sheets, the static gas screen is arranged on the air/gas side channel, the flue gas channel adopts a single flow, and the air/gas side channel adopts double-flow cross-flow heat exchange.
The heat exchange and low-temperature corrosion resistant effects of the double preheating system of the blast furnace hot blast stove with the low-temperature corrosion resistant core are further enhanced.
Compared with the prior art, the invention has the following beneficial effects:
according to the blast furnace hot blast stove double preheating system with the low-temperature corrosion resistant core, the static air screen is designed at the position where the heat exchange core of the low-temperature section heat exchange module is coldest and most prone to dew point corrosion, so that the preheating system has the advantages of being high in heat exchange efficiency, compact in structure, long in service life, not prone to dust accumulation, easy to clean, free in module combination and the like, and low-temperature dew point corrosion is prevented under the condition of relatively low cost.
Drawings
FIG. 1 is a schematic structural view of a low temperature corrosion resistant core according to the present invention;
FIG. 2 is a schematic diagram of the static gas curtain of the present invention;
FIG. 3 is a schematic view of the structure of the metal plate of the present invention;
FIG. 4 is a schematic structural diagram of a dual preheating system of a blast furnace hot blast stove using a dual-flow cross-flow heat exchange band low temperature corrosion resistant core according to the present invention;
FIG. 5 is a comparative test chart of the presence or absence of a static gas shield in a dual preheating system of a blast furnace hot blast stove using a dual-flow cross-flow heat exchange band low temperature corrosion resistant core according to the present invention;
in the figure: 1. the flue gas inlet is variable in diameter; 2. a purging system; 3. the air/coal gas outlet is variable in diameter; 4. the air/gas inlet is variable in diameter; 5. the flue gas outlet is variable in diameter; 6. cross-connecting the air duct; 7. a high-temperature section heat exchange module; 8. a low-temperature section heat exchange module; 9. an inspection manhole; 10. a sheet; 11. a static air shield; 12. a metal plate; 13. spacing; 14. a triangular region; 15. a flue gas channel; 16. air/gas side channels.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
example 1
As shown in fig. 1-4, the dual preheating system of the blast furnace hot blast stove with the low temperature corrosion resistant core comprises a high temperature section heat exchange module 7 and a low temperature section heat exchange module 8, wherein the low temperature section heat exchange module 8 comprises a frame and the low temperature corrosion resistant core; the low-temperature corrosion resistant core body comprises a plurality of superposed plate pairs, each plate pair comprises symmetrically superposed plates 10, and independent gas channels are formed between the plates 10, and the low-temperature corrosion resistant core body is characterized in that a static gas screen 11 is arranged on each plate 10, and the plates 10 are made of corrosion resistant materials; the static air curtain 11 is arranged in a triangular area 14 of the low-temperature section heat exchange module 8.
The static gas screen 11 has heat insulation effect without heat conduction and convection, so that the temperature of the plate 10 is kept above the dew point temperature in the heat exchange process to avoid low-temperature dew point corrosion. A static air shield 11 is arranged in a coldest triangular area 14 which is most prone to low-temperature corrosion on the low-temperature section heat exchange module 8, and the temperature of the plate 10 is kept above the dew point temperature in the heat exchange process under the heat preservation effect of the static air shield 11, so that low-temperature dew point corrosion is avoided.
Wherein the spacing 13 of the static air curtains 11 is 2-5 mm.
Further enhancing the heat preservation effect.
The static air shield 11 is formed by sealing a metal plate 12 and the plate 10, the metal plate 12 is triangular, and the metal plate 12 is made of corrosion-resistant materials.
The low-temperature corrosion area is triangular, so that the metal plate 12 is triangular and is consistent with the low-temperature corrosion area, the low-temperature dew point corrosion of the low-temperature corrosion area is prevented, and meanwhile, materials are saved.
Wherein distance posts or support bars are arranged between the metal plate 12 and the plate 10.
For adjusting the spacing 13 of the static gas curtain 11.
Wherein the plate 10 is embossed with bulges.
For adjusting the spacing 13 of the static gas curtain 11.
Wherein the corrosion resistant material comprises one or more of austenitic stainless steel, duplex stainless steel and ND steel.
Further enhancing the corrosion resistance.
Wherein the sheet 10 and the metal plate 12 are sealed at their edges by a self-fluxing weld or a sealing weld.
The air is prevented from failing to achieve the heat preservation effect along with the flowing of the heat exchange main air flow, and on the other hand, the gas can be prevented from mixing into the static gas screen 11 to corrode the plate 10.
The device comprises a high-temperature section heat exchange module 7, a low-temperature section heat exchange module 8, a flue gas inlet reducing module 1, a purging system 2, an air/gas outlet reducing module 3, an air/gas inlet reducing module 4, a flue gas outlet reducing module 5, a cross-over air channel 6 and an overhaul manhole 9, wherein the flue gas inlet reducing module 1, the air/gas outlet reducing module 3, the air/gas inlet reducing module 4, the flue gas outlet reducing module 5 and the cross-over air channel 6 are arranged on the periphery of the high-temperature section heat exchange module 7 and the low-temperature section heat exchange module 8, and the overhaul manhole 9 is arranged on the flue gas inlet reducing module 1, the air/gas outlet reducing module 3, the air.
The plate heat exchanger keeps the advantages of high heat exchange efficiency, compact structure, long service life, difficult dust accumulation, easy cleaning and free module combination, and further prevents the low-temperature dew point corrosion through the heat preservation effect of the low-cost static gas screen 11.
Wherein, a flue gas channel 15 is formed between the adjacent plate pairs, an air/gas side channel 16 is formed between the symmetrically stacked plates 10, the static gas screen 11 is arranged on the air/gas side channel 16, the flue gas channel adopts a single flow, and the air/gas side channel adopts double-flow cross flow heat exchange.
Here, the static gas shield 11 is disposed in the air/gas side channel 16, and after the edges of the plate 10 and the metal plate 12 are sealed by self-fluxing welding or seal welding, the air is prevented from failing to achieve the heat preservation effect along with the flow of the heat exchange main gas, and the gas is prevented from mixing into the static gas shield 11 to corrode the plate 10. The high-temperature section heat exchange module 7 and the low-temperature section heat exchange module 8 can be formed by connecting an air plate preheater and a gas plate preheater in parallel and respectively form an independent preheating circulating system with the flue gas; the parallel air/gas side channel adopts double-flow cross flow heat exchange.
The heat exchange and low-temperature corrosion resistant effects of the double preheating system of the blast furnace hot blast stove with the low-temperature corrosion resistant core are further enhanced.
The blast furnace hot blast stove double preheating system with the low temperature corrosion resistant core body has the working process as follows:
flue gas enters the high-temperature section heat exchange module 7 and the low-temperature section heat exchange module 8 along the flue gas inlet reducing diameter 1 for heat exchange and then is discharged through the flue gas outlet reducing diameter 5, and air/coal gas enters the high-temperature section heat exchange module 7 and the low-temperature section heat exchange module 8 along the air/coal gas outlet reducing diameter 3 for heat exchange and then is discharged through the air/coal gas inlet reducing diameter 4. In the heat exchange process, the static gas screen 11 is arranged in the coldest triangular area 14 which is most prone to low-temperature corrosion, and the heat preservation effect of the static gas screen 11 enables the temperature of the plate 10 to be kept above the dew point temperature in the heat exchange process so as to avoid low-temperature dew point corrosion.
As shown in fig. 5, according to the test results, the lowest temperature of the plate 10 with the static gas shield 11 design is 20-40 degrees higher than that of the plate 10 without the static gas shield 11 design.
In summary, the double preheating system of the blast furnace hot blast stove with the low temperature corrosion resistant core of the invention designs the static air shield 11 at the coldest part of the heat exchange core of the low temperature section heat exchange module 8 which is most likely to form dew point corrosion, so that the preheating system not only has the advantages of high heat exchange efficiency, compact structure, long service life, difficult dust accumulation, easy cleaning, free module combination and the like, but also prevents the low temperature dew point corrosion from occurring under the condition of relatively low cost.
Claims (9)
1. The double-preheating system of the blast furnace hot blast stove with the low-temperature corrosion resistant core is characterized by comprising a high-temperature section heat exchange module (7) and a low-temperature section heat exchange module (8), wherein the low-temperature section heat exchange module (8) comprises a frame and the low-temperature corrosion resistant core; the low-temperature corrosion resistant core body comprises a plurality of superposed plate pairs, each plate pair comprises symmetrically superposed plates (10), and independent gas channels are formed between the plates (10), and the low-temperature corrosion resistant core body is characterized in that a static gas screen (11) is arranged on each plate (10), and the plates (10) are made of corrosion resistant materials; the static air shield (11) is arranged in a triangular area (14) of the low-temperature section heat exchange module (8).
2. A low temperature corrosion resistant heat exchange core according to claim 1, wherein the spacing (13) of the static gas shields (11) is 2-5 mm.
3. The heat exchange core resistant to low temperature corrosion according to claim 1, wherein the static gas shield (11) is formed by sealing a metal plate (12) and the plate (10), the metal plate (12) is triangular, and the metal plate (12) is made of a corrosion-resistant material.
4. A low temperature corrosion resistant heat exchange core according to claim 3, wherein distance posts or support bars are provided between the metal plates (12) and the plates (10).
5. A low temperature corrosion resistant heat exchange core according to claim 3 wherein the plates (10) are embossed with bulges.
6. The heat exchange core of claim 3, wherein the corrosion resistant material comprises one or more of austenitic stainless steel, duplex stainless steel, ND steel.
7. A low temperature corrosion resistant heat exchange core according to claim 3, wherein the plate (10) and the metal plate (12) edges are sealed by self-fluxing or sealing welding.
8. The blast furnace hot blast stove double preheating system with the low-temperature corrosion resistant core according to any one of claims 1 to 7, further comprising a flue gas inlet reducing diameter (1), a purging system (2), an air/gas outlet reducing diameter (3), an air/gas inlet reducing diameter (4), a flue gas outlet reducing diameter (5), a cross-over air duct (6) and an inspection manhole (9), wherein the flue gas inlet reducing diameter (1), the air/gas outlet reducing diameter (3), the air/gas inlet reducing diameter (4), the flue gas outlet reducing diameter (5) and the cross-over air duct (6) are arranged at the periphery of the high-temperature section heat exchange module (7) and the low-temperature section heat exchange module (8), and the inspection manhole (9) is arranged at the periphery of the flue gas inlet reducing diameter (1), the air/gas outlet reducing diameter (3), the air/gas inlet reducing diameter (4), The flue gas outlet is provided with a variable diameter (5) and is connected with the air duct (6) in a bridging way.
9. The blast furnace stove double preheating system with low temperature corrosion resistant core according to any of claims 1 to 7, wherein a flue gas channel (15) is formed between adjacent plate pairs, an air/gas side channel (16) is formed between the symmetrically stacked plates (10), the static air screen (11) is arranged on the air/gas side channel (16), the flue gas channel adopts a single flow path, and the air/gas side channel adopts a double flow path cross flow heat exchange.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011312971.1A CN112481438A (en) | 2020-11-20 | 2020-11-20 | Blast furnace hot blast stove double-preheating system with low-temperature corrosion resistant core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011312971.1A CN112481438A (en) | 2020-11-20 | 2020-11-20 | Blast furnace hot blast stove double-preheating system with low-temperature corrosion resistant core |
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| Publication Number | Publication Date |
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| CN112481438A true CN112481438A (en) | 2021-03-12 |
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| CN202011312971.1A Pending CN112481438A (en) | 2020-11-20 | 2020-11-20 | Blast furnace hot blast stove double-preheating system with low-temperature corrosion resistant core |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201355049Y (en) * | 2009-02-26 | 2009-12-02 | 厦门铭光机械制造有限公司 | Hot-air furnace air and gas double preheating all-welded plate-type heat exchanger |
| EP2169195A1 (en) * | 2008-09-25 | 2010-03-31 | Valeo Systemes Thermiques | Heat exchanging element of a heat exchange bundle in a heat exchanger |
| CN106839856A (en) * | 2017-03-16 | 2017-06-13 | 上海板换机械设备有限公司 | Heat exchanger, heat exchanger plates component and anticorrosion heat exchanger plates |
| CN206862184U (en) * | 2017-03-16 | 2018-01-09 | 上海板换机械设备有限公司 | Heat exchanger, heat exchanger plates components and anticorrosion heat exchanger plates |
| CN110982976A (en) * | 2020-01-06 | 2020-04-10 | 宝钢湛江钢铁有限公司 | Plate type gas-gas heat exchanger |
| CN210773588U (en) * | 2019-08-01 | 2020-06-16 | 上海齐耀热能工程有限公司 | Plate type air preheater |
-
2020
- 2020-11-20 CN CN202011312971.1A patent/CN112481438A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2169195A1 (en) * | 2008-09-25 | 2010-03-31 | Valeo Systemes Thermiques | Heat exchanging element of a heat exchange bundle in a heat exchanger |
| CN201355049Y (en) * | 2009-02-26 | 2009-12-02 | 厦门铭光机械制造有限公司 | Hot-air furnace air and gas double preheating all-welded plate-type heat exchanger |
| CN106839856A (en) * | 2017-03-16 | 2017-06-13 | 上海板换机械设备有限公司 | Heat exchanger, heat exchanger plates component and anticorrosion heat exchanger plates |
| CN206862184U (en) * | 2017-03-16 | 2018-01-09 | 上海板换机械设备有限公司 | Heat exchanger, heat exchanger plates components and anticorrosion heat exchanger plates |
| CN210773588U (en) * | 2019-08-01 | 2020-06-16 | 上海齐耀热能工程有限公司 | Plate type air preheater |
| CN110982976A (en) * | 2020-01-06 | 2020-04-10 | 宝钢湛江钢铁有限公司 | Plate type gas-gas heat exchanger |
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Application publication date: 20210312 |