Full-dry-method sensible heat recovery device and method for converter gas OG method transformation

Abstract

The invention discloses a total dry method sensible heat recovery device and method for converter gas OG method transformation. The total dry method sensible heat recovery device comprises a converter, an evaporation cooling flue, a gas cooler and a switching station. The inlet end of the evaporative cooling flue is connected with an outlet of the converter, an outlet of the evaporative cooling flue is connected with an inlet of the gas cooler, and a smoke outlet is formed in the position, close to the bottom, of the gas cooler and connected with an inlet of the switching station. Compared with a traditional boiler heat exchanger, the gas cooler is adopted, a forced convection efficient heat exchange mode is adopted, the temperature gradient isothermal body design is optimized, the heat efficiency is improved, meanwhile, the temperature of equipment does not change drastically, meanwhile, the equipment structure is reduced, and a transformation project can be conveniently installed in a converter workshop. According to the whole technological process, water is not sprayed to the converter gas, the converter gas is always kept dry, and compared with a traditional water spraying cooling mode, water resources are greatly saved, environmental pollution is reduced, heat is recycled, waste of gas heat is avoided, and the heat value of the gas is increased.

Description

Technical Field

[0001] The invention belongs to the field of converter gas treatment, and relates to a device and method for recovering sensible heat by a full dry method for converting a converter gas OG method. Background Art

[0002] The mature treatment method for converter gas is the OG method. The OG method (Oxygen Gas Recovery System) is a traditional converter gas recovery method, which was jointly developed by Nippon Steel and Kawasaki Corporation in Japan in the 1960s. Currently, about 90% of the converters in the world use the OG method. The OG method belongs to the full wet dust removal and gas recovery of converter flue gas. The flue gas volume is controlled by the micro-pressure difference at the furnace mouth. The smoke hood and the skirt adopt a high-temperature hot water closed circulation cooling system. The flue adopts vaporization cooling. In the entire dust removal system, water spraying is used to achieve the purpose of flue gas cooling and dust removal. The biggest disadvantages of this method are high energy consumption, large water consumption, complex sewage treatment, and high operating costs. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a fully dry sensible heat recovery device and method for the OG method of converter gas, which greatly saves water resources, reduces environmental pollution, recovers heat, avoids the waste of gas heat, and improves the calorific value of gas.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A fully dry sensible heat recovery device for converter gas OG process transformation, comprising a converter, a vaporization cooling flue, a gas cooler and a switching station; The inlet end of the vaporization cooling flue is connected to the outlet of the converter, and the outlet of the vaporization cooling flue is connected to the inlet of the gas cooler. The gas cooler is provided with a flue gas outlet near the bottom, and the flue gas outlet is connected to the inlet of the switching station.

[0005] Preferably, the coal gas cooler is provided with a deoxygenated water inlet pipe and a steam outlet pipe, the steam outlet pipe is connected to the drum inlet, and the drum outlet is connected to a pipe network.

[0006] Preferably, the cooling wall of the coal gas cooler adopts finned heat exchange tubes.

[0007] Preferably, an economizer is connected between the gas cooler and the switching station.

[0008] Preferably, the outlet of the switching station is divided into two routes, one route is connected to a gas storage cabinet, and the other route is connected to an automatic ignition and dispersion chimney.

[0009] Preferably, a cyclone gas-solid separator is connected between the vaporization cooling flue and the coal gas cooler, and a metal film dry dust collector is connected between the coal gas cooler and the switching station.

[0010] Furthermore, the metal film dry dust collector adopts a rigid high temperature resistant metal film filter cartridge.

[0011] Furthermore, nitrogen-sealed ash discharge devices are provided at the bottom of the cyclone gas-solid separator, the coal gas cooler and the metal film dry dust collector.

[0012] A fully dry sensible heat recovery method for converter gas OG method transformation, converter gas at about 1450-1600°C is generated at the converter top outlet, the converter gas first passes through a vaporization cooling flue for heat exchange, and is cooled to 800-1000°C after passing through the vaporization cooling flue, the cooled converter gas enters from the top of a gas cooler, and is discharged from the bottom after heat exchange, the temperature after heat exchange is 150-200°C, and the converter gas after heat exchange passes through a switching station for subsequent process treatment.

[0013] Preferably, the converter gas after cooling enters the cyclone gas-solid separator, which uses the inertia generated by centrifugal force to remove 70% of the coarse particles and dust in the converter gas. The converter gas after primary dust removal enters the gas cooler for heat exchange, and the converter gas after heat exchange enters the metal film dry dust collector for secondary dust removal. The dust content of the converter gas after dust removal is less than 10 mg / m 3 .

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a gas cooler with efficient waste heat recovery. Compared with the traditional boiler heat exchanger, it uses a forced convection efficient heat exchange mode, optimizes the temperature gradient isothermal body design, improves thermal efficiency while maintaining the equipment temperature without drastic changes, and reduces the equipment structure, which is convenient for the transformation project to be installed in the converter workshop. The entire process does not spray water on the converter gas, and the converter gas is always kept dry. Compared with the traditional form of water spraying and cooling, it greatly saves water resources, reduces environmental pollution, recovers heat, avoids the waste of gas heat, and improves the calorific value of gas.

[0015] Furthermore, the gas cooler reduces the converter flue gas temperature from about 1000°C to about 200°C, which can generate saturated steam for utilization, thereby improving the utilization efficiency of converter gas waste heat.

[0016] Furthermore, the converter gas is further cooled to 70°C in the economizer, and the economizer will recover this part of the low-temperature heat source.

[0017] Furthermore, when unqualified gas is produced, that is, when the oxygen content of the converter gas does not meet the standard, the switching valve in the switching station is quickly switched to guide the unqualified converter gas into the automatic ignition and dispersion chimney, and the unqualified gas is discharged after combustion. When the generated gas is qualified, the switching station switches and guides the gas into the gas storage cabinet.

[0018] Furthermore, by matching cyclone gas-solid separators and metal membrane dry dust collectors, the dust in the front stage is treated in two steps according to its high temperature, high concentration and large particle size. By matching appropriate dust removal processes, it can save investment and operating costs while meeting ultra-low emissions.

[0019] Furthermore, the nitrogen-sealed ash discharge device ensures that air is effectively prevented from entering the system during ash discharge, fully suppressing explosions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the fully dry sensible heat recovery device for converter gas OG process transformation according to the present invention.

[0021] Among them: 1-converter, 2-vaporization cooling flue, 3-three-way switching valve group, 4-cyclone gas-solid separator, 5-gas cooler, 6-steam drum, 7-metal film dry dust collector, 8-economizer, 9-fan unit, 10-switching station, 11-gas storage cabinet, 12-automatic ignition and dispersion chimney. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0027] like Figure 1 As shown, the fully dry sensible heat recovery device for the OG method transformation of converter gas according to the present invention includes a converter 1, a vaporization cooling flue 2, a three-way switching valve group 3, a cyclone gas-solid separator 4, a gas cooler 5, a steam drum 6, a metal film dry dust collector 7, an economizer 8, a fan unit 9, a switching station 10, a gas storage cabinet 11 and an automatic ignition and dispersion chimney 12.

[0028] The top outlet of the converter 1 produces converter gas at about 1450-1600°C, the inlet end of the vaporization and cooling flue 2 is connected to the outlet of the converter 1, the high-temperature converter gas first passes through the vaporization and cooling flue 2 for heat exchange, and is cooled to 800-1000°C after passing through the vaporization and cooling flue 2, the outlet of the vaporization and cooling flue 2 is connected to the three-way switching valve group 3, one end of the three-way switching valve group 3 is connected to the original OG method equipment, and the other end is connected to the cyclone gas-solid separator 4, to ensure that the original OG system can be used as a backup system, which can be switched at any time to ensure that the converter production is not interrupted. The vaporization and cooling flue 2 and the converter 1 are inherent to the original system and are not included in the process of the present invention.

[0029] The cyclone gas-solid separator 4 is a high-temperature pre-dust removal device, which adopts a cyclone structure. The cyclone gas-solid separator 4 uses the inertia generated by centrifugal force to remove 70% of the coarse particles and dust in the converter gas, achieving primary dust removal and preventing these coarse particles and dust from washing the cooling wall of the subsequent gas cooler. The bottom of the cyclone gas-solid separator 4 is equipped with a nitrogen sealed ash removal device.

[0030] The cyclone gas-solid separator 4 adopts a vertical structure, and a temporary ash storage bin and a nitrogen-sealed ash discharge valve are arranged at the lower part of the cyclone gas-solid separator 4 to timely clean the coarse particles and dust collected by the cyclone gas-solid separator 4.

[0031] The outlet of the cyclone gas-solid separator 4 is connected to the inlet of the gas cooler 5. The gas cooler 5 adopts a forced convection high-efficiency heat exchange mode and optimizes the temperature gradient isothermal body design. The converter gas enters from the top of the gas cooler 5 and is discharged from the bottom after heat exchange. The converter gas after heat exchange is 150°C to 200°C. The gas cooler 5 is provided with a deoxygenated water inlet pipe and a steam outlet pipe. The deoxygenated water enters the internal heat exchange pipe of the gas cooler 5 through the deoxygenated water inlet pipe. Steam is generated after heat exchange. The steam outlet pipe is connected to the inlet of the drum 6. The outlet of the drum 6 is connected to the pipe network. The drum 6 converts the intermittently generated steam into stable and continuous low-pressure saturated steam, which is then transported to the pipe network.

[0032] The cooling wall type of the gas cooler 5 is a finned heat exchange tube, which uses a forced convection high-efficiency heat exchange mode and optimizes the temperature gradient isothermal body design to improve thermal efficiency while maintaining no drastic changes in the equipment temperature, reducing the impact of thermal stress and thermal alternating stress; the heat exchange tubes inside the equipment are designed with expansion capacity, and will not leak due to stress fatigue damage.

[0033] After the converter gas passes through the gas cooler 5 for heat exchange, the flue gas temperature drops to ~200°C. A flue gas outlet is provided near the bottom of the gas cooler 5, and the flue gas outlet of the gas cooler 5 is connected to the inlet of the metal film dry dust collector 7. The converter gas at 150°C~200°C undergoes secondary dust removal in the metal film dry dust collector 7. The dust content of the converter gas after dust removal is less than 10mg / m 3 The metal film dry dust collector 7 is a complete set of equipment, equipped with a full set of dust removal, nitrogen sealing ash discharge, venting, explosion relief, and switching valve devices.

[0034] Metal film dry dust collector 7 uses a rigid high temperature resistant metal film filter cartridge, which can withstand temperatures up to 450°C and is fully adaptable to 200°C operating conditions and occasional over-temperature conditions of 300°C. The dust content at the outlet of the metal film dry dust collector 7 is less than 10mg / m 3 The metal film dry dust collector 7 is a complete set of equipment, equipped with complete dust removal equipment, inlet and outlet valves, venting device, and nitrogen system.

[0035] The cyclone gas-solid separator 4, the gas cooler 5 and the bottom of the metal film dry dust collector 7 are all provided with nitrogen sealed ash discharge devices to ensure that air is effectively prevented from entering the system during ash discharge and explosion is fully suppressed.

[0036] The outlet of the metal film dry dust collector 7 is connected to the economizer 8, and the converter gas is further cooled to 70°C in the economizer 8, and the economizer 8 will recover this part of the low-temperature heat source. The outlet of the economizer 8 is connected to the fan unit 9, and the fan is variable frequency speed regulation to adapt to the production process of the converter 1 and save energy and reduce consumption. A switching station 10 is set at the outlet end of the fan unit 9. The outlet end of the switching station 10 is divided into two paths, one leading to the gas storage cabinet 11, and the other leading to the automatic ignition and diffusion chimney 12. When unqualified gas is generated, that is, when the oxygen content of the converter gas does not meet the standard, the switching valve in the switching station 10 is quickly switched, and the unqualified converter gas is introduced into the automatic ignition and diffusion chimney 12, and the unqualified gas is discharged after combustion treatment. When the generated gas is qualified, the switching station 10 is switched to introduce the gas into the gas storage cabinet 11. The automatic ignition and dispersion chimney 12 includes equipment such as an igniter, a combustion-supporting fan, a low-nitrogen burner, and a chimney body.

[0037] The switching station 10 is equipped with an anti-leakage switching valve group to ensure that no gas leakage occurs during switching.

[0038] The present invention adopts full-dry waste heat recovery technology, which greatly increases the saturated steam volume of the converter, improves the calorific value of coal gas, reduces the volume of coal gas, optimizes the coal gas quality, and the original primary dust removal (OG) is no longer used, thereby saving a lot of water resources, and a lot of electricity for fans and water pumps. The national -30 kgce benchmark level of the converter process is fully achieved, and the converter gas dust removal outlet achieves ultra-low emissions. At the same time, the problems of explosiveness, high dust content and intermittency of converter gas are solved, ensuring that the heat recovery process is stable and continuous.

[0039] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0040] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A fully dry sensible heat recovery device for converter gas OG process transformation, characterized in that: It comprises a converter (1), a vaporization cooling flue (2), a coal gas cooler (5) and a switching station (10); The inlet end of the vaporization cooling flue (2) is connected to the outlet of the converter (1), and the outlet of the vaporization cooling flue (2) is connected to the inlet of the coal gas cooler (5). The coal gas cooler (5) is provided with a flue gas outlet near the bottom, and the flue gas outlet is connected to the inlet of the switching station (10).

2. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 1 is characterized in that: The coal gas cooler (5) is provided with a deoxygenated water inlet pipe and a steam outlet pipe, the steam outlet pipe is connected to the inlet of the steam drum (6), and the outlet of the steam drum (6) is connected to a pipe network.

3. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 1 is characterized in that: The cooling wall of the coal gas cooler (5) adopts finned heat exchange tubes.

4. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 1 is characterized in that: An economizer (8) is connected between the coal gas cooler (5) and the switching station (10).

5. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 1 is characterized in that: The outlet of the switching station (10) is divided into two paths, one of which is connected to a gas storage cabinet (11) and the other is connected to an automatic ignition and dispersion chimney (12).

6. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 1 is characterized in that: A cyclone gas-solid separator (4) is connected between the vaporization cooling flue (2) and the coal gas cooler (5), and a metal film dry dust collector (7) is connected between the coal gas cooler (5) and the switching station (10).

7. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 6 is characterized in that: The metal film dry dust collector (7) adopts a rigid high temperature resistant metal film filter cartridge.

8. The fully dry sensible heat recovery device for converter gas OG process transformation according to claim 6 is characterized in that: The cyclone gas-solid separator (4), the coal gas cooler (5) and the bottom of the metal film dry dust collector (7) are all provided with nitrogen sealed dust discharge devices.

9. A method for recovering sensible heat from a fully dry process for converter gas OG process transformation based on the device according to any one of claims 1 to 8, characterized in that: The converter gas at a temperature of about 1450 to 1600° C. is generated at the top outlet of the converter (1). The converter gas first undergoes heat exchange through the vaporization cooling flue (2). After passing through the vaporization cooling flue (2), the converter gas is cooled to a temperature of 800 to 1000° C. The cooled converter gas enters from the top of the gas cooler (5) and is discharged from the bottom after heat exchange. The temperature after heat exchange is 150 to 200° C. The converter gas after heat exchange passes through the switching station (10) for subsequent process treatment.

10. The method for recovering sensible heat by fully dry method for converter gas OG process transformation according to claim 9, characterized in that: The converter gas after cooling enters the cyclone gas-solid separator (4), which uses the inertia generated by centrifugal force to remove 70% of the coarse particles and dust in the converter gas. The converter gas after primary dust removal enters the gas cooler (5) for heat exchange, and the converter gas after heat exchange enters the metal film dry dust collector (7) for secondary dust removal. The dust content of the converter gas after dust removal is less than 10 mg / m 3 .

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