CN204752784U - Converter coal gas processing system - Google Patents

Abstract

The utility model relates to a converter gas treatment system, which comprises a high-temperature gas treatment section, a dust removal mechanism, an induced draft fan and a switching station connected in sequence through a gas pipeline, and the switching station is connected with a gas recovery section and a gas release section; the high-temperature gas treatment section includes The high-temperature gas waste heat recovery mechanism, the high-temperature gas waste heat recovery mechanism includes a saturated steam production structure and a steam accumulator for storing saturated steam; the gas release section includes a molten salt circulation mechanism for recovering and releasing the waste heat of the gas, and the molten salt circulation mechanism includes heat A molten salt production structure and a steam superheater that exchanges heat with the hot molten salt, and the steam accumulator communicates with the steam superheater through a steam pipeline. The treatment system can effectively recover the physical sensible heat of the vented converter gas, reduce the water consumption of the evaporative cooler, and continuously produce superheated steam.

Description

Converter gas treatment system

technical field

The utility model belongs to the technical field of the metallurgical industry, in particular to a converter gas treatment system.

Background technique

The converter gas dry dedusting system is a process of purifying gas widely used in the converter steelmaking process of the metallurgical industry.

Converter gas dry dedusting system mainly includes vaporization cooling flue, evaporative cooler, coarse and fine dedusting device, induced draft fan, switching station, etc. Converter gas first reduces the temperature of the gas to about 850°C through the vaporization cooling flue, and then cools it down to about 200°C through the evaporative cooler sprayed with water. The CO and _O2 content determines whether to recover or vent the gas.

In the above-mentioned dry dedusting process, although part of the physical waste heat is recovered, the CO content of the converter is low during the pre-firing and post-firing periods. When the CO content in the gas is <30% or O ₂ >2%, it will pass through The chimney let off the gas. The way to release is to use the ignition device on the top of the chimney to ignite the gas, and burn the unqualified gas. Generally, in order to ignite and completely burn the gas, an ever-burning torch is often set on the top of the chimney. The gas is burned in vain, generating heat exhaust. into the atmosphere, wasting a lot of energy, and also does not meet environmental protection requirements.

Therefore it is necessary to design a converter gas treatment system to overcome the above problems.

Utility model content

The purpose of the utility model is to overcome the defects of the prior art and provide a converter gas treatment system, which can recover more physical sensible heat in the converter gas and can continuously produce superheated steam at the same time.

The utility model is achieved in that:

The utility model provides a converter gas treatment system, which includes a high-temperature gas treatment section, a dust removal mechanism, an induced draft fan and a switching station connected sequentially through a gas pipeline, and the switching station is provided with a first gas outlet for switching on and off and a second Gas outlet, the first gas outlet is connected to a gas recovery section, the second gas outlet is connected to a gas release section; the high-temperature gas treatment section includes a high-temperature gas waste heat recovery mechanism, and the high-temperature gas waste heat recovery mechanism includes a saturated steam production structure and a steam accumulator for storing saturated steam; the gas release section includes a molten salt circulation mechanism for recovering and releasing waste heat of the gas, and the molten salt circulation mechanism includes a hot molten salt production structure and a hot molten salt exchange A hot steam superheater, the steam accumulator communicates with the steam superheater through a steam pipeline.

Further, the hot molten salt production structure includes a combustion heat release chamber, the combustion heat release chamber is provided with a release gas inlet, a combustion flue gas outlet and an air inlet, the release gas inlet communicates with the switching station, the The combustion flue gas outlet communicates with the chimney, and the air inlet is connected with a blower; the steam superheater includes a steam chamber, and the steam chamber communicates with the steam heat accumulator through a steam pipeline; the molten salt circulation mechanism also includes A molten salt circulation loop passing through the combustion heat release chamber and the steam chamber respectively.

Further, the molten salt circulation circuit includes a hot molten salt pipeline for circulating hot molten salt and a cold molten salt pipeline for circulating cold molten salt, a hot molten salt tank is arranged on the hot molten salt pipeline, and the A cold molten salt tank is arranged on the cold molten salt pipeline.

Further, a hot molten salt pump is provided on the hot molten salt pipeline between the hot molten salt tank and the steam chamber, and a hot molten salt pump is installed on the cold molten salt pipeline between the cold molten salt tank and the combustion heat release chamber Equipped with cold molten salt pump.

Further, the pipelines of the molten salt circulation circuit located in the combustion heat release chamber and the steam chamber are arranged in a serpentine shape.

Further, the temperature of the hot molten salt is 300-500°C, the steam superheater includes a superheated steam outlet, and the temperature of the superheated steam is 250-450°C.

Further, the saturated steam production structure includes a vaporization cooling flue and a steam drum, and the two ends of the vaporization cooling flue are respectively connected with the converter gas outlet and the dust removal mechanism; the wall of the vaporization cooling flue is provided with a cooling water pipe The cooling water pipeline is provided with a cooling water inlet and a gas outlet, and the steam drum is provided with a gas inlet, a cooling water outlet and a saturated steam outlet, the cooling water inlet communicates with the cooling water outlet, and the gas outlet It communicates with the gas inlet, and the saturated steam outlet communicates with the steam heat accumulator.

Further, a circulation pump is provided on the connecting water pipe between the cooling water outlet and the cooling water inlet.

Further, the high-temperature gas treatment section further includes an evaporative cooler, and the evaporative cooler is arranged between the evaporative cooling flue and the dust removal mechanism.

Further, the dust removal mechanism includes a coarse dust collector and a fine dust collector arranged in sequence along the gas flow direction, the coarse dust collector is a gravity dust collector, a centrifugal dust collector or an inertial dust collector, and the fine dust collector is a bag filter , electrostatic precipitator or ceramic precipitator.

The utility model has the following beneficial effects: the heat of the high-temperature converter gas is recovered through the vaporization cooling flue, the heat of the diffused converter gas is recovered through the molten salt circulation mechanism, the physical sensible heat of the diffused converter gas can be effectively recovered, and the waste heat utilization rate is high. In the steam superheater, hot molten salt heats saturated steam into superheated steam, and hot molten salt and saturated steam can be stored separately, so superheated steam can be produced continuously without being affected by intermittent oxygen blowing, which is convenient for subsequent steam users.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the present utility model, and those skilled in the art can also obtain other drawings according to these drawings without creative work.

Fig. 1 is a schematic structural diagram of a converter gas treatment system provided by an embodiment of the present invention.

Detailed ways

The technical solutions 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 them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

As shown in Figure 1, this embodiment provides a converter gas treatment system, including a high-temperature gas treatment section, a dust removal mechanism, an induced draft fan 7 and a switching station 8 connected in sequence through a gas pipeline, and the switching station 8 is provided with a switch for opening and closing The first gas outlet and the second gas outlet, the first gas outlet is connected with a gas recovery section, the second gas outlet is connected with a gas release section, and the gas can be recovered through the gas recovery section according to the _CO and O content in the gas Or release the gas through the gas release section. Wherein, the gas recovery section includes a gas cooler 9 and a gas cabinet 10 connected in sequence, and the gas cooler 9 is connected to the first gas outlet. The dust removal mechanism includes a primary dust removal mechanism and a secondary dust removal mechanism arranged in sequence along the gas flow direction, the primary dust removal mechanism includes a coarse dust collector 5 , and the secondary dust removal mechanism includes a fine dust collector 6 .

The high-temperature gas treatment section includes a high-temperature gas waste heat recovery mechanism, and the high-temperature gas waste heat recovery mechanism includes a saturated steam production structure and a steam heat accumulator 20 for storing saturated steam. Wherein, the saturated steam production structure includes a vaporization cooling flue 1 and a steam drum 3, and the two ends of the vaporization cooling flue 1 are respectively connected with the converter gas outlet and the primary dust removal mechanism; A cooling water pipeline is provided, the cooling water pipeline is provided with a cooling water inlet and a gas outlet, the steam drum 3 is provided with a gas inlet, a cooling water outlet and a saturated steam outlet, and the cooling water inlet communicates with the cooling water outlet , the gas outlet communicates with the gas inlet, and the saturated steam outlet communicates with the steam accumulator 20 . A circulation pump 4 may be provided on the connecting water pipe between the cooling water outlet of the steam drum 3 and the cooling water inlet of the cooling water pipeline as required to improve the circulation efficiency of the cooling water. The cooling water in the steam drum 3 enters the cooling water pipeline and is heated by the high-temperature gas in the vaporization cooling flue 1 to form a steam-water mixture. The steam-water mixture enters the steam drum 3, and the saturated steam in the steam drum 3 enters the steam heat accumulator through the pipeline Store within 20. The temperature of the saturated steam is 170-250° C., and the temperature of the high-temperature gas drops to 800-900° C. after passing through the vaporization cooling flue 1 .

Further, the high-temperature gas treatment section also includes an evaporative cooler 2, which is arranged between the evaporative cooling flue 1 and the primary dust removal mechanism. The coal gas cooled by the vaporization cooling flue 1 enters the evaporative cooler 2, sprays water in the evaporative cooler 2 to extinguish the fire in the gas, and further cools the gas to 400~600°C to form low-temperature gas. Spraying water in the evaporative cooler 2 extinguishes the fire in the gas, ensuring the safe operation of the system. Since the gas in the evaporative cooler 2 only needs to be cooled to 400-600° C., the amount of water sprayed in the evaporative cooler 2 is reduced.

As shown in Figure 1, the gas release section includes a molten salt circulation mechanism for recovering and releasing the waste heat of the gas, and the molten salt circulation mechanism includes a hot molten salt production structure and a steam superheater 19 for heat exchange with the hot molten salt, the steam The heat accumulator 20 communicates with the steam superheater 19 through a steam pipeline. The hot molten salt production structure includes a combustion heat release chamber 11, the combustion heat release chamber 11 is provided with a diffused gas inlet, a combustion flue gas outlet and an air inlet, and the diffused gas inlet is communicated with the switching station 8, the The combustion flue gas outlet communicates with the chimney 14 through the exhaust fan 13 , and the air inlet is connected with a blower 12 . The steam superheater 19 includes a steam chamber, and the steam chamber communicates with the steam accumulator 20 through a steam pipeline; the molten salt circulation mechanism also includes a molten salt circulation loop, and the molten salt circulation loop respectively passes through The combustion heat release chamber 11 and the steam chamber. That is, the combustion heat release chamber 11 is set on the gas release pipeline, absorbs the waste heat of the low-temperature gas through the heat transfer between the molten salt and the gas, and the heated hot molten salt is used to heat the saturated steam to generate superheated steam. Among them, the temperature of the hot molten salt produced is 300~500°C, the temperature of the gas coming out of the molten salt heater is below 200°C; the temperature of the superheated steam is 250~450°C. The molten salt pipelines located in the combustion heat release chamber 11 and the steam chamber are arranged in a serpentine shape, which can increase the contact area between the molten salt pipeline and gas or steam, and improve heat transfer efficiency. The steam superheater 19 includes a superheated steam outlet, which is connected to a steam user. The quality of the steam is high and the application range is wide. If the subsequent steam user is a turbo-generator unit, then the superheated steam with greatly increased temperature and pressure can greatly improve the thermal efficiency of the turbo-generator unit, and at the same time improve the steam-water condition inside the steam turbine and reduce the corrosion of the tail blades of the steam turbine.

Further, the molten salt circulation circuit includes a hot molten salt pipeline for hot molten salt circulation and a cold molten salt pipeline for cold molten salt circulation, and a hot molten salt tank 17 is arranged on the hot molten salt pipeline, so A cold molten salt tank 15 is provided on the cold molten salt pipeline. A hot molten salt pump 18 is provided on the hot molten salt pipeline between the hot molten salt tank 17 and the steam chamber, and a hot molten salt pump 18 is provided on the cold molten salt pipeline between the cold molten salt tank 15 and the gas chamber. Cold molten salt pump16. The hot molten salt tank 17 is set to store hot molten salt. During the intermittent oxygen blowing process, when not blowing oxygen, the hot molten salt stored in the hot molten salt tank 17 and the saturated steam stored in the steam accumulator 20 are introduced into the In the steam superheater 19, the continuous production of superheated steam can be realized without being affected by intermittent oxygen blowing.

In this embodiment, the coarse dust collector 5 can be a gravity dust collector, a centrifugal dust collector or an inertial dust collector, and the fine dust collector 6 can be a bag dust collector, an electrostatic dust collector or a ceramic dust collector. In addition, molten salt can also be replaced by other heat carriers.

The working process of the converter gas treatment system provided in this embodiment is:

The converter gas generated by the converter enters the vaporization cooling flue 1 for cooling, the cooling water in the steam drum 3 enters the cooling water pipeline in the vaporization cooling flue 1 through the circulation pump 4, and the cooling water exchanges heat with the converter gas to form a steam-water mixture and returns to the steam In the drum 3, the saturated steam in the steam drum 3 is sent to the steam accumulator 20 through pipelines to charge and store heat.

The converter gas (temperature about 850°C) coming out of the vaporization cooling flue 1 enters the evaporative cooler 2, and sprays water in the evaporative cooler 2 to cool down to 400~600°C to form low-temperature gas. The low-temperature gas passes through the coarse dust collector 5 and the fine dust collector 6 to remove dust in turn, and then enters the switching station 8 through the induced draft fan 7 .

The CO and _O2 content in the converter gas is detected by the online device in the switching station 8. When the CO and O2 in the converter gas are >30% and _O2 <2%, the converter gas enters the gas cooler 9 through the switching station 8 and cools down to about 70 ℃, and then enter the gas cabinet 10 for storage. When CO<30% or O ₂ >2% in the converter gas, the converter gas is switched to the combustion heat exchange chamber through the switching station 8 for combustion. Air is sent into the room; the radiant heat of combustion and the heat of flue gas are used to heat the cold molten salt to about 500°C, and the flue gas after heat exchange is cooled to about 200°C, and is discharged to the atmosphere through the exhaust fan 13 and the chimney 14.

The hot molten salt heated in the combustion heat exchange chamber enters the hot molten salt tank 17 for storage, and the hot molten salt pump 18 sucks the hot molten salt from the hot molten salt tank 17 and sends it to the steam superheater 19. After passing through the steam superheater 19, The molten salt temperature drops to about 250°C, and then enters the cold molten salt tank 15. The cold molten salt pump 16 draws the cold molten salt from the cold molten salt tank 15, and sends it into the combustion heat exchange chamber for heating, thus forming a cycle. The external saturated steam (170-250°C) in the steam heat accumulator 20 is sent to the steam superheater 19 through pipelines to exchange heat with hot molten salt, and is heated into superheated steam with a temperature of 250-450°C to steam users.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in the Within the protection scope of the present utility model.

Claims (10)

1. a coal gas of converter treatment system, it is characterized in that: comprise the coal gas of high temperature processing section, dedusting mechanism, induced draft fan and the switching station that are communicated with successively by gaspipe line, described switching station is provided with the first gas exit and the second gas exit that switch and open and close, described first gas exit is connected with coal-gas recovering section, and described second gas exit is connected with coal gas diffusion section; Described coal gas of high temperature processing section comprises coal gas of high temperature waste heat recovering mechanism, and described coal gas of high temperature waste heat recovering mechanism comprises saturation steam production structure and the steam accumulator for storing saturation steam; Described coal gas diffusion section comprises the fused salt cycling mechanism for reclaiming emission coal gas waste heat, described fused salt cycling mechanism comprises hot melt salt production structure and the vapor superheater with hot fused salt heat exchanging, and described steam accumulator is communicated with described vapor superheater by vapour line.

2. coal gas of converter treatment system according to claim 1, it is characterized in that: described hot melt salt production structure comprises combustion heat release room, described combustion heat release room is provided with emission coal gas entrance, combustion product gases outlet and gas inlet, described emission coal gas entrance is communicated with described switching station, described combustion product gases outlet is communicated with chimney, and described gas inlet is connected with gas blower; Described vapor superheater comprises sweating room, and described sweating room is communicated with described steam accumulator by vapour line; Described fused salt cycling mechanism also comprises fused salt circulation loop, and described fused salt circulation loop is each passed through described combustion heat release room and described sweating room.

3. coal gas of converter treatment system according to claim 2, it is characterized in that: described fused salt circulation loop comprises the hot molten salt pipeline of heat supply fused salt circulation and the cold molten salt pipeline of cooling fused salt circulation, described hot molten salt pipeline is provided with hot melt salt cellar, and described cold molten salt pipeline is provided with sloppy heat salt cellar.

4. coal gas of converter treatment system according to claim 3, it is characterized in that: the hot molten salt pipeline between described hot melt salt cellar and described sweating room is provided with hot melt salt pump, the cold molten salt pipeline between described sloppy heat salt cellar and described combustion heat release room is provided with sloppy heat salt pump.

5. coal gas of converter treatment system according to claim 2, is characterized in that: described fused salt circulation loop is positioned at all snakelike layout of pipeline of described combustion heat release indoor and described sweating room.

6. coal gas of converter treatment system according to any one of claim 1 to 5, is characterized in that: the temperature of described hot melt salt is 300 ~ 500 DEG C, and described vapor superheater comprises superheated vapour outlet, and the temperature of superheated vapour is 250 ~ 450 DEG C.

7. coal gas of converter treatment system according to any one of claim 1 to 5, it is characterized in that: described saturation steam production structure comprises gasification cooling flue and drum, described gasification cooling flue two ends export with coal gas of converter respectively and are communicated with described dedusting mechanism; Cooling water pipeline is provided with in described gasification cooling flue wall, described cooling water pipeline is provided with cooling water inlet and pneumatic outlet, described drum is provided with gas inlet, cooling water outlet and saturation steam outlet, described cooling water inlet is communicated with described cooling water outlet, described pneumatic outlet is communicated with described gas inlet, and described saturation steam outlet is communicated with described steam accumulator.

8. coal gas of converter treatment system according to claim 7, is characterized in that: the connecting water pipe between described cooling water outlet and described cooling water inlet is provided with recycle pump.

9. coal gas of converter treatment system according to claim 7, is characterized in that: described coal gas of high temperature processing section also comprises evaporative cooler, and described evaporative cooler is located between described gasification cooling flue and described dedusting mechanism.

10. coal gas of converter treatment system according to claim 1, it is characterized in that: described dedusting mechanism comprises the rough cleaner and smart fly-ash separator that set gradually along coal gas circulating direction, described rough cleaner is gravitational precipitator, centrifugal deduster or inertial dust separator, and described smart fly-ash separator is sack cleaner, electrostatic precipitator or Ceramic dust collector.