Converter flue gas full-dry-method full-energy recovery system

Abstract

The invention discloses a converter flue gas full-dry-method full-energy recovery system which comprises a converter and an evaporative cooling flue which are connected through a pipeline, and further comprises a high-temperature coal gas switching station, a dust remover, a waste heat boiler, a fan, a coal gas overtemperature cooling tower, a converter gas holder, a catalytic reactor, a waste heat diffusion boiler, a diffusion fan and a chimney. The high-temperature coal gas switching station is divided into two bypasses which are respectively a recovery bypass and a diffusion bypass, the recovery bypass and the diffusion bypass of the high-temperature coal gas switching station are respectively connected with an evaporative cooling flue pipeline, and the diffusion bypass of the high-temperature coal gas switching station is connected with a catalytic reactor pipeline. The catalytic reactor is in pipeline connection with the waste heat diffusing boiler, the waste heat diffusing boiler is in pipeline connection with the diffusing fan, the diffusing fan is in pipeline connection with the chimney, a recovery bypass of the high-temperature gas switching station is in pipeline connection with the dust remover, the dust remover is in pipeline connection with the waste heat boiler, and the waste heat boiler is in pipeline connection with the fan. The fan is connected with the gas overtemperature cooling tower through a pipeline, and the gas overtemperature cooling tower is connected with the converter gas holder through a pipeline.

Description

Technical Field

[0001] The invention belongs to the technical field of converter flue gas recovery, and in particular relates to a converter flue gas full-dry method full-energy recovery system. Background Art

[0002] The converter is an important part of the steel production process, and a large amount of waste heat is generated during the production process. In the pre-burning / post-burning section of the converter, the gas composition will have a CO concentration of <35% and an O2 concentration of >2%, which poses a risk of explosion.

[0003] At present, the wet method (OG method) and dry method (LT method) process systems are generally used for cooling and dust removal of converter gas at home and abroad. Their common characteristics are: using vaporization cooling flue (converter waste heat boiler) to recover the sensible heat of converter high temperature (initial temperature is about 1500℃) gas, and using water spraying / water mist spraying to cool and remove dust for gas cooled to about 850℃ to reduce the risk of explosion. 50% of the sensible heat of converter gas is wasted. The recovery of waste energy and waste heat of converter gas can greatly reduce the energy consumption of converter steelmaking process, but the medium and low temperature (<850℃) waste heat of converter gas has not yet been recovered and utilized.

[0004] Instructions attached Figure 2 This is the converter flue gas treatment process in the prior art: the furnace gas generated by the converter is mixed with a small amount of air leaked from the surrounding area and flows through the vaporized water-cooled flue gas, the temperature of which drops from 1500°C to ~850°C, and then enters the evaporative cooler to be cooled to about 200°C by steam / water, then enters the electrostatic precipitator, and is then led out through the fan. Because the CO content of the converter is less than 30% and the oxygen content is greater than 2% during the pre-burning and post-burning stages, there is an explosion risk or the calorific value is too low to be used, and the recycling conditions are not met, so a release treatment is required. A gas switching station is set up behind the fan. When the gas quality meets the recycling conditions, it is sent to the gas cooling tower to be cooled to below 70°C and sent to the converter gas cabinet for recycling. When the gas quality does not meet the recycling conditions, it is sent to the release torch for combustion treatment. The disadvantages of the above scheme are: 1. Evaporative coolers and gas cooling towers consume water and steam, which easily lead to waste of resources; 2. When the CO / O2 content of the gas reaches the recovery standard and there is no explosion risk, it is still cooled by the evaporative cooler, resulting in waste of sensible heat; 3. The thermal energy of the released gas is not utilized.

[0005] Therefore, this scheme provides a converter flue gas full dry method full energy recovery system for improving the utilization rate of converter gas waste heat. Summary of the invention

[0006] In view of the problems raised by the above background technology, the purpose of the present invention is to provide a converter flue gas full dry method full energy recovery system for improving the utilization rate of converter gas waste heat.

[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0008] A converter flue gas full dry method full energy recovery system, comprising a converter and a vaporization cooling flue, wherein the converter is connected to the vaporization cooling flue pipeline, and further comprising a high-temperature coal gas switching station, a dust collector, a waste heat boiler, a fan, a coal gas super-temperature cooling tower, a converter gas holder, a catalytic reactor, a dissipation waste heat boiler, a dissipation fan and a chimney, wherein the high-temperature coal gas switching station is divided into two bypasses, namely a recovery bypass and a dissipation bypass, wherein the recovery bypass and the dissipation bypass of the high-temperature coal gas switching station are respectively connected to the vaporization cooling flue pipeline The discharge bypass of the high-temperature coal gas switching station is connected to the catalytic reactor pipeline, the catalytic reactor is connected to the discharge waste heat boiler pipeline, the discharge waste heat boiler is connected to the discharge fan pipeline, the discharge fan is connected to the chimney pipeline, the recovery bypass of the high-temperature coal gas switching station is connected to the dust collector pipeline, the dust collector is connected to the waste heat boiler pipeline, the waste heat boiler is connected to the fan pipeline, the fan is connected to the coal gas over-temperature cooling tower pipeline, and the coal gas over-temperature cooling tower is connected to the converter gas holder pipeline.

[0009] It is further defined that the high temperature switching station can switch to a recovery bypass or a release bypass, and the switching condition is that when the CO and O2 contents meet the standards, it switches to the recovery bypass, and when the CO and O2 contents do not meet the standards, it switches to the release bypass.

[0010] It is further defined that the dust collector can be a ceramic particle dust collector or a ceramic fiber dust collector. Such a structural design makes the dust removal effect the best. The ceramic particle dust collector mainly uses ceramic particles as the filter medium to capture the dust through the gaps between the particles. This dust collector may belong to the category of granular bed filters, whose filter medium is composed of solid particles and has the characteristics of continuous operation and resistance to flow fluctuations; the ceramic fiber dust collector is a device that uses ceramic fiber filter materials to purify the gas. Ceramic fiber has excellent properties such as high temperature stability, acid and alkali corrosion resistance, and high mechanical strength. Therefore, it can effectively remove dust particles and tiny particles to meet environmental protection requirements; in addition to the aforementioned two types of dust collectors, other high temperature resistant dust collectors can also be selected according to user needs.

[0011] It is further defined that the waste heat boiler is provided with an economizer, and the economizer is used to reduce the flue gas temperature. Such a structural design can reduce the flue gas temperature to 70°C, avoiding the situation where the flue gas temperature is too high.

[0012] It is further defined that a water spray system is provided in the coal gas over-temperature cooling tower, and the water spray system is used to spray water to cool the waste heat boiler outlet when the outlet is over-temperature. Such a structural design can spray water through the water spray system when the outlet of the waste heat boiler is over-temperature, and cool its temperature to below 70°C.

[0013] It is further defined that the catalytic reactor is provided with a wide temperature catalyst, and the wide temperature catalyst is used for catalyzing and oxidizing CO within a temperature range of 300 to 800°C.

[0014] It is further defined that it also includes an explosion relief valve, one end of the third bypass pipeline is connected between the explosion relief valve and the catalytic reactor, and the other end of the third bypass is connected to the rear end of the exhaust fan. With such a structural design, the working principle of the explosion relief valve is based on the rupture of the bursting membrane to release pressure. When the internal pressure of the equipment rises to the set bursting pressure, the bursting membrane will rupture in time, and the valve cover will pop up, thereby quickly releasing the pressure. This process is automatic and does not require external power, so it can respond quickly and prevent the equipment from exploding.

[0015] It is further defined that it also includes a return air fan, a supplementary air regulating valve and a smoke return air regulating valve which are sequentially arranged on the third bypass.

[0016] Beneficial effects of the present invention:

[0017] 1. This solution provides a full-dry full-energy recovery system for converter flue gas. By setting up a high-temperature gas switching station and a waste heat boiler, such a setting can determine the diversion of gas in advance so that it does not have the risk of explosion. At the same time, the sensible heat of 70-850℃ generated in the gas recovery stage is utilized, thereby improving the utilization rate of converter gas waste heat;

[0018] 2. By setting up a high-temperature gas switching station, a catalytic reactor and a waste heat dissipation boiler, during the dissipation, the flue gas is mixed to reduce the CO concentration, and the low-temperature catalytic oxidation of CO is beneficial to reduce the CO concentration during the dissipation and reduce the risk of explosion. At the same time, the sensible heat and chemical heat of the gas generated in the dissipation stage are recycled, thereby improving the utilization rate of the converter gas waste heat;

[0019] 3. By setting up waste heat boilers and waste heat dissipation boilers to recover the gas and the heat during the dissipation, and also recover the low-grade heat source of the flue gas, no water is sprayed in the flue gas during the whole process or the water spraying is reduced. By setting up economizers instead of spraying steam / water for cooling, the use of water resources is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0021] Figure 1 It is a prior art converter flue gas treatment flow chart of an embodiment of a converter flue gas full dry method full energy recovery system of the present invention;

[0022] Figure 2 The present invention is a flow chart of converter flue gas treatment according to an embodiment of a converter flue gas full-dry method full-energy recovery system.

[0023] The symbols of the main components are explained as follows: converter 1, vaporization cooling smoke 2, high-temperature coal gas switching station 3, dust collector 4, waste heat boiler 5, fan 6, coal gas over-temperature cooling tower 7, converter gas holder 8, explosion relief valve 9, catalytic reactor 10, dissipation waste heat boiler 11, dissipation fan 12, chimney 13, flue gas return air regulating valve 14, make-up air regulating valve 15, return air fan 16. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] like Figure 1As shown, a converter flue gas full dry method full energy recovery system of the present invention comprises a converter 1 and a vaporization cooling flue 2, wherein the converter 1 is connected to the vaporization cooling flue 2 by a pipeline, and further comprises a high-temperature coal gas switching station 3, a dust collector 4, a waste heat boiler 5, a fan 6, a coal gas super-temperature cooling tower 7, a converter gas holder 8, a catalytic reactor 10, a dissipation waste heat boiler 11, a dissipation fan 12 and a chimney 13, wherein the high-temperature coal gas switching station 3 is divided into two bypasses, namely a recovery bypass and a dissipation bypass, wherein the recovery bypass and the dissipation bypass of the high-temperature coal gas switching station 3 are respectively connected to the vaporization cooling flue 2 by a pipeline. The discharge bypass of the high-temperature gas switching station 3 is connected to the catalytic reactor 10 through a pipeline, the catalytic reactor 10 is connected to the discharge waste heat boiler 11 through a pipeline, the discharge waste heat boiler 11 is connected to the discharge fan 12 through a pipeline, the discharge fan 12 is connected to the chimney 13 through a pipeline, the recovery bypass of the high-temperature gas switching station 3 is connected to the dust collector 4 through a pipeline, the dust collector 4 is connected to the waste heat boiler 5 through a pipeline, the waste heat boiler 5 is connected to the fan 6 through a pipeline, the fan 6 is connected to the gas over-temperature cooling tower 7 through a pipeline, and the gas over-temperature cooling tower 7 is connected to the converter gas holder 8 through a pipeline.

[0028] Preferably, the high temperature switching station 3 can switch to a recovery bypass or a release bypass, and the switching condition is to switch to the recovery bypass when the CO and O2 contents meet the standards, and to switch to the release bypass when the CO and O2 contents do not meet the standards.

[0029] Preferably, the dust collector can be a ceramic particle dust collector or a ceramic fiber dust collector. Such a structural design makes the dust removal effect the best. The ceramic particle dust collector mainly uses ceramic particles as the filter medium, and captures the dust through the gaps between the particles. This dust collector may belong to the category of granular bed filters, whose filter medium is composed of solid particles and has the characteristics of continuous operation and resistance to flow fluctuations; the ceramic fiber dust collector is a device that uses ceramic fiber filter materials to purify the gas. Ceramic fiber has excellent properties such as high temperature stability, acid and alkali corrosion resistance, and high mechanical strength. Therefore, it can effectively remove dust particles and tiny particles to meet environmental protection requirements; in addition to the aforementioned two types of dust collectors, other high temperature resistant dust collectors can also be selected according to user needs.

[0030] Preferably, an economizer is provided in the waste heat boiler 5, and the economizer is used to reduce the flue gas temperature. Such a structural design can reduce the flue gas temperature to 70°C, avoiding the situation where the flue gas temperature is too high.

[0031] Preferably, a water spray system is provided in the coal gas overtemperature cooling tower 7, and the water spray system is used to spray water to cool the outlet of the waste heat boiler 5 when the outlet is overtemperature. With such a structural design, water can be sprayed through the water spray system when the outlet of the waste heat boiler 5 is overtemperature, and its temperature can be cooled to below 70°C.

[0032] Preferably, the catalytic reactor 10 is provided with a wide temperature catalyst, and the wide temperature catalyst is used for catalyzing and oxidizing CO within a temperature range of 300 to 800°C.

[0033] Preferably, it further includes an explosion relief valve 9, one end of the third bypass pipeline is connected between the explosion relief valve 9 and the catalytic reactor 10, and the other end of the third bypass is connected to the rear end of the dispersion fan 12. With such a structural design, the working principle of the explosion relief valve is based on the rupture of the bursting membrane to release the pressure. When the internal pressure of the equipment rises to the set bursting pressure, the bursting membrane will rupture in time, and the valve cover will pop up, thereby quickly releasing the pressure. This process is automatic and does not require external power, so it can respond quickly and prevent the equipment from exploding.

[0034] Preferably, it also includes a return air fan, an air supply regulating valve and a smoke return air regulating valve which are sequentially arranged on the third bypass, one end of the third bypass pipeline is connected between the explosion relief valve and the catalytic reactor, and the other end of the third bypass is connected to the rear end of the dispersion fan.

[0035] The working principle of this embodiment is as follows:

[0036] In the gas recovery stage, the gas generated by the converter 1 enters the primary vaporization cooling flue 2, passes through the high-temperature gas switching station 3 and enters the dust collector 4 for dust removal, and then passes through the waste heat boiler 5 to cool down to 70°C and enter the fan 6 for pressurization and is sent to the gas over-temperature cooling tower 7 and the converter gas cabinet 8;

[0037] In the gas release stage, the gas coming out of the high-temperature gas switching station 3 enters the release bypass. After passing through the high-temperature gas switching station 3, the gas enters the inlet of the catalytic reactor 10, and is mixed with the flue gas after the return air fan 16 and enters the catalytic reactor 10. By adjusting the flue gas return air regulating valve 14 and the air supply regulating valve 15, and after being pressurized by the return air fan 16, the catalytic reactor 10 is provided with oxygen required for oxidation, and the CO concentration is diluted to outside the explosion range. The CO in the flue gas is catalytically burned in the catalytic reactor 10, the flue gas is heated, and the heat is recovered by the waste heat boiler 11 and then sent to the chimney 13 for discharge.

[0038] This solution sets a high-temperature gas switching station 3 to determine the concentration of CO and oxygen in advance, thereby diverting the gas to prevent explosion hazards; a waste heat boiler 5 is set to utilize the sensible heat of 70-850°C generated in the gas recovery stage, thereby improving the utilization rate of the converter gas waste heat;

[0039] By setting up the high-temperature coal gas switching station 3, the catalytic reactor 10 and the waste heat dissipation boiler 11, during the dissipation, the flue gas is mixed to reduce the CO concentration, and the low-temperature catalytic oxidation of CO is beneficial to reduce the CO concentration during the dissipation and reduce the risk of explosion. At the same time, the sensible heat and chemical heat of the coal gas generated in the dissipation stage are recycled, thereby improving the utilization rate of the waste heat of the converter coal gas;

[0040] By setting up a waste heat boiler 5 and a waste heat dissipation boiler 11, the coal gas and the heat during the dissipation are recovered, and the low-grade heat source of the flue gas is also recovered. No water is sprayed into the flue gas or the water spraying is reduced during the whole process. By setting up an economizer instead of spraying steam / water for cooling, the use of water resources is reduced.

[0041] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A converter flue gas full dry method full energy recovery system, comprising a converter (1) and a vaporization cooling flue (2), wherein the converter (1) is connected to the vaporization cooling flue (2) through a pipeline, and is characterized in that: The high-temperature coal gas switching station (3) further comprises a high-temperature coal gas switching station (3), a dust collector (4), a waste heat boiler (5), a fan (6), a coal gas over-temperature cooling tower (7), a converter gas holder (8), a catalytic reactor (10), a dissipation waste heat boiler (11), a dissipation fan (12) and a chimney (13). The high-temperature coal gas switching station (3) is divided into two bypasses, namely a recovery bypass and a dissipation bypass. The recovery bypass and the dissipation bypass of the high-temperature coal gas switching station (3) are respectively connected to the vaporization cooling flue (2) pipeline, and the dissipation bypass of the high-temperature coal gas switching station (3) is connected to the catalytic reactor (10) pipeline. The catalytic reactor (10) is connected to a waste heat dissipation boiler (11) via a pipeline, the waste heat dissipation boiler (11) is connected to a dissipation fan (12) via a pipeline, the dissipation fan (12) is connected to a chimney (13) via a pipeline, the recovery bypass of the high-temperature coal gas switching station (3) is connected to a dust collector (4) via a pipeline, the dust collector (4) is connected to a waste heat boiler (5) via a pipeline, the waste heat boiler (5) is connected to a fan (6) via a pipeline, the fan (6) is connected to a coal gas over-temperature cooling tower (7) via a pipeline, and the coal gas over-temperature cooling tower (7) is connected to a converter gas holder (8) via a pipeline.

2. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: The high temperature switching station (3) can switch to a recovery bypass or a release bypass, and the switching condition is that when the CO and O2 contents meet the standards, the system switches to the recovery bypass, and when the CO and O2 contents do not meet the standards, the system switches to the release bypass.

3. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: The dust collector (4) can be a ceramic particle dust collector or a ceramic fiber dust collector.

4. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: The waste heat boiler (5) is provided with an economizer, and the economizer is used to reduce the flue gas temperature.

5. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: The coal gas over-temperature cooling tower (7) is provided with a water spray system, and the water spray system is used to spray water to cool the outlet of the waste heat boiler (5) when the outlet is over-temperature.

6. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: The catalytic reactor (10) is provided with a wide temperature catalyst, and the wide temperature catalyst is used for catalyzing and oxidizing CO within a temperature range of 300 to 800°C.

7. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: It also comprises an explosion relief valve (9), which is arranged before the catalytic reactor (10), and the explosion relief valve (9) is connected to the catalytic reactor (10) through a pipeline.

8. The converter flue gas full dry method full energy recovery system according to claim 1, characterized in that: It also includes a return air fan (16), an air supply regulating valve (15) and a smoke return air regulating valve (14) which are sequentially arranged on a third bypass. One end of the third bypass pipeline is connected between the explosion relief valve (9) and the catalytic reactor (10), and the other end of the third bypass is connected to the rear end of the dispersion fan (12).

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