Combined device and method for desulfurization, decarbonization and on-line unblocking of blast furnace gas

Abstract

The invention provides a blast furnace gas desulfurization, decarburization and online unblocking combined device and method. The device comprises a heat exchange temperature control unit, a desulfurization purification unit and a decarburization regeneration unit which are sequentially connected from front to back, the desulfurization purification unit comprises a dechlorination pretreatment reaction tower, a hydrolysis reaction tower and an adsorption reaction tower which are sequentially communicated from front to back, and radial washing reaction towers are adopted as the dechlorination pretreatment reaction tower, the hydrolysis reaction tower and the adsorption reaction tower respectively; a discharge port of the decarburization and regeneration unit is connected with a feed port of the liquid carbon dioxide preparation unit, and a discharge port of the liquid carbon dioxide preparation unit is connected with a feed port of the dry ice preparation, storage and distribution unit; a discharge port of the dry ice preparation, storage and distribution unit is connected with a flushing port of the heat exchange temperature control unit; and the discharge port of the dry ice preparation, storage and distribution unit is also respectively connected with outer hole cylinder flushing ports and inner hole cylinder flushing ports of the dechlorination pretreatment reaction tower, the hydrolysis reaction tower and the adsorption reaction tower. The device provided by the invention realizes the goal of carbon emission reduction and resource utilization of carbon dioxide.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy saving and environmental protection, and relates to a blast furnace gas pollution reduction and carbon reduction equipment and method, in particular to a combined device and method for blast furnace gas desulfurization and decarburization and online blockage cleaning. BACKGROUND

[0002] The typical dry blast furnace gas mainly contains CO: 24.0-26.0%, CO2: 20.0-24.0%, H2: 2.0-3.0%, N2: 49.0-53.0%, and O2: 0.0-1.5%. The impurities and pollutants in the blast furnace gas after dust removal mainly include tar, dust, salt, organic sulfur (mainly COS), inorganic sulfur (mainly H2S), hydrogen chloride, etc. The content of these impurities and pollutants is generally 500 mg / Nm 3 Under the requirements of ultra-low emission and green development of pollution reduction and carbon reduction in the steel industry, the desulfurization and decarburization of blast furnace gas, which is the largest by-product gas of steel enterprises, is crucial.

[0003] At present, the low-temperature hydrolysis conversion and dry adsorption catalytic oxidation desulfurization technology of blast furnace gas after TRT has become mature, and many sets of devices have been constructed and operated nationwide. However, in the operation process, the dust, tar and crystalline salt in the gas frequently block the radial flushing reaction tower orifice plate and the heat exchanger tube bundle. The commonly used industrial steam purging method is not suitable for the blast furnace gas desulfurization purification device. At present, it mainly relies on offline flushing and cleaning, and lacks effective online blockage cleaning means, which affects the stable operation of the device. Therefore, there is an urgent need for a device and method integrating desulfurization and decarburization and online blockage cleaning functions to solve the above problems.

[0004] The method for blast furnace gas decarburization and simultaneous fine desulfurization disclosed in CN116478739A patent adopts a decarburization and then desulfurization process route. The acid impurities such as chlorides and sulfides contained in the gas will pollute the absorption liquid and cause the absorption efficiency to decrease, which has a significant adverse effect on the amine method for removing carbon dioxide. This process route has disadvantages in process setting, and the process is complex and requires repeated adjustment of the gas temperature, resulting in high energy consumption and large equipment investment.

[0005] The blast furnace gas desulfurization and decarburization system and process disclosed in CN115558529A patent uses an absorbent to simultaneously remove H2S and carbon dioxide, but the subsequent desorption of the absorbent and separation of sulfur are relatively complex, the overall process is relatively long, the system is complex, the operation and maintenance are difficult, and there are multiple temperature rising and falling and condensation gas-liquid separation operations, which have relatively high energy consumption.

[0006] CN113684068A patent discloses a CO2 capture and utilization device suitable for blast furnace gas, which adopts limestone-gypsum wet desulfurization before decarburization, and adopts alkali liquor spraying for fine desulfurization. Because the content of carbon dioxide in the gas is much higher than that of H2S, part of the carbon dioxide will be absorbed by the alkali liquor at the same time in the alkali liquor spraying desulfurization process, which weakens the selectivity of the absorption liquid to H2S and increases the solvent loss, causing waste of alkali liquor. This method has been proved to have poor effect in the past blast furnace gas desulfurization, and is rarely used now. SUMMARY

[0007] In view of the deficiencies in the prior art, the purpose of the present application is to provide a combined device and method for blast furnace gas desulfurization and decarburization and online cleaning, which solves the technical problem that the online cleaning of the device for blast furnace gas desulfurization and decarburization is difficult to achieve.

[0008] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0009] A combined device for blast furnace gas desulfurization and decarburization and online cleaning, comprising a heat exchange and temperature control unit, the discharge port of the heat exchange and temperature control unit being connected to the feed port of a desulfurization and purification unit, and the discharge port of the desulfurization and purification unit being connected to the feed port of a decarburization and regeneration unit.

[0010] The desulfurization and purification unit comprises a dechlorination pretreatment reaction tower, a hydrolysis reaction tower and an adsorption reaction tower connected in sequence from front to back.

[0011] The dechlorination pretreatment reaction tower, the hydrolysis reaction tower and the adsorption reaction tower each adopt a radial flushing reaction tower.

[0012] The discharge port of the decarburization and regeneration unit is connected to the feed port of a liquid carbon dioxide preparation unit, and the discharge port of the liquid carbon dioxide preparation unit is connected to the feed port of a dry ice preparation, storage and distribution unit.

[0013] The discharge port of the dry ice preparation, storage and distribution unit is also connected to the flushing port of the heat exchange and temperature control unit.

[0014] The discharge port of the dry ice preparation, storage and distribution unit is also connected to the outer hole cylinder flushing port of the dechlorination pretreatment reaction tower, the hydrolysis reaction tower and the adsorption reaction tower, respectively.

[0015] The discharge port of the dry ice preparation, storage and distribution unit is also connected to the inner hole cylinder flushing port of the dechlorination pretreatment reaction tower, the hydrolysis reaction tower and the adsorption reaction tower, respectively.

[0016] The present application also has the following technical features:

[0017] Specifically, the radial flushing reaction tower comprises a closed radial flushing reaction tower shell, an inner cavity of the radial flushing reaction tower shell is an installation cavity, a bottom plate is horizontally arranged near the bottom in the installation cavity, and an outer side wall of the bottom plate is fixedly connected with an inner side wall of the radial flushing reaction tower shell in a circumferential direction.

[0018] The axial upper segment installation cavity is coaxially sleeved with an outer hole cylinder which is cylindrical and open at both axial ends, the axial upper end of the outer hole cylinder is fixedly connected with the top inner wall of the radial flushing reaction tower shell, and the axial lower end of the outer hole cylinder is fixedly connected with the upper portion of the bottom plate.

[0019] The radial flushing reaction tower shell is further provided with a plurality of outer hole cylinder flushing openings which are uniformly arranged on the upper portion of the bottom plate in a circumferential direction.

[0020] The axial upper segment installation cavity is further provided with a plurality of outer hole cylinder flushing pipelines which are uniformly arranged between the inner side wall of the radial flushing reaction tower shell and the outer side wall of the outer hole cylinder in a circumferential direction, each outer hole cylinder flushing pipeline is arranged in an axial direction, and each outer hole cylinder flushing pipeline is connected with the outer hole cylinder flushing opening through a first introduction hose.

[0021] Each outer hole cylinder flushing pipeline is further provided with a plurality of outer hole cylinder nozzles which are arranged in an axial direction and arranged at the outer hole cylinder flushing openings.

[0022] The radial flushing reaction tower shell is further provided with an inner hole cylinder flushing opening which is arranged at the axial upper end of the inner hole cylinder.

[0023] The axial upper segment installation cavity is further provided with an inner hole cylinder flushing pipeline which is coaxially sleeved in the inner hole cylinder, and the axial upper end of the inner hole cylinder flushing pipeline is connected with the inner hole cylinder flushing opening through a second introduction hose.

[0024] The inner hole cylinder flushing pipeline is further provided with a plurality of inner hole cylinder nozzles which are arranged in an axial direction and arranged at the inner hole cylinder flushing openings.

[0025] Specifically, the axial two ends of the outer hole cylinder flushing pipeline are closed, the axial lower end of the outer hole cylinder flushing pipeline is provided with an outer pipe lower end buffer spring, the axial lower end of the outer pipe lower end buffer spring is fixedly connected with the upper part of the bottom plate; the axial upper end of the outer hole cylinder flushing pipeline is provided with an outer pipe upper end buffer spring, the axial upper end of the outer pipe upper end buffer spring is fixedly connected with the inner wall of the radial flushing reaction tower shell.

[0026] The side wall of the radial flushing reaction tower shell is also provided with a plurality of axial up-down reciprocating assemblies, and the axial up-down reciprocating assemblies can enable the outer hole cylinder flushing pipeline to reciprocate along the axial direction.

[0027] The inner side wall of the radial flushing reaction tower shell is also provided with a plurality of outer pipe support guides, and the plurality of outer pipe support guides are uniformly arranged along the axial direction and the circumferential direction respectively, each outer pipe support guide is connected with the outer hole cylinder flushing pipeline, and the plurality of outer pipe support guides can support and guide the outer hole cylinder flushing pipeline when the outer hole cylinder flushing pipeline reciprocates along the axial direction.

[0028] The radial flushing reaction tower shell is also provided with a driving motor, the output shaft of the driving motor is coaxially arranged with the inner hole cylinder flushing pipeline, the inner hole cylinder flushing pipeline can be driven by the output shaft of the driving motor to rotate around the central axis thereof.

[0029] The inner side wall of the inner hole cylinder is also provided with a plurality of inner pipe support guides, and the plurality of inner pipe support guides are uniformly arranged along the axial direction, and the plurality of inner pipe support guides can support and guide the inner hole cylinder flushing pipeline when the inner hole cylinder flushing pipeline rotates along the circumferential direction.

[0030] Specifically, the cavity between the inner side wall of the outer hole cylinder and the outer side wall of the inner hole cylinder is a filler filling cavity, and the filler filling cavity is filled with filler.

[0031] The side wall of the outer hole cylinder is also provided with a plurality of outer hole cylinder gas passages penetrating through the side wall in the radial direction, and the plurality of outer hole cylinder gas passages are uniformly arranged along the axial direction and the circumferential direction respectively.

[0032] The side wall of the inner hole cylinder is also provided with a plurality of inner hole cylinder gas passages penetrating through the side wall in the radial direction, and the plurality of inner hole cylinder gas passages are uniformly arranged along the axial direction and the circumferential direction respectively.

[0033] The axial lower end of the radial flushing reaction tower shell is also provided with a reaction gas first passage, and the axial upper end of the radial flushing reaction tower shell is also provided with a reaction gas second passage; the bottom plate is also provided with a plurality of reaction gas third passages, and the plurality of reaction gas third passages are arranged between the outer hole cylinder and the radial flushing reaction tower shell.

[0034] The output shaft of the driving motor is also coaxially sleeved with a protective sleeve, and the protective sleeve is arranged in the inside of the axial lower section installation cavity.

[0035] The bottom plate is also provided with a sealing element arranged at the connection between the output shaft of the driving motor and the inner hole cylinder flushing pipeline.

[0036] The connection between the inner hole cylinder flushing pipeline and the second introduction hose is also provided with a rotating joint.

[0037] Specifically, the feed inlet of the heat exchange temperature control unit is connected with the blast furnace gas conveying pipeline.

[0038] The heat exchange temperature control unit comprises a heat exchanger, and the heat exchanger comprises one or more combinations of a GGH heat exchanger, a heater and a cooler.

[0039] The reaction gas first passage of the dechlorination pretreatment reaction tower is connected with the discharge outlet of the heat exchange temperature control unit; calcium-based or alumina-based dechlorination agents are arranged in the dechlorination pretreatment reaction tower to adsorb hydrogen chloride impurities in the coal gas to remove Cl-; γ-Al2O3-based hydrolysis agents are arranged in the hydrolysis reaction tower to convert organic sulfur into inorganic sulfur; iron oxide-based or activated carbon-based adsorbents are arranged in the adsorption reaction tower to remove inorganic sulfur, so that the coal gas is desulfurized and purified, and the purified clean coal gas is obtained.

[0040] The decarburization and regeneration unit comprises an absorption tower, the feed inlet of the absorption tower is connected with the reaction gas second passage of the adsorption reaction tower, the discharge outlet of the absorption tower is connected with the feed inlets of the absorption tower and the desorption tower auxiliary equipment, the discharge outlets of the absorption tower and the desorption tower auxiliary equipment are connected with the feed inlet of the desorption tower, and the discharge outlet of the desorption tower is connected with the feed inlet of the liquid carbon dioxide preparation unit.

[0041] The absorption tower and the desorption tower auxiliary equipment comprise one or more combinations of a cooling tower, a lean-liquid and rich-liquid heat exchanger and a washing tower.

[0042] The liquid carbon dioxide preparation unit comprises one or more combinations of a compressor, an ice machine, a pre-cooler, a rectifying tower, a condenser, a super-cooler and a product storage tank.

[0043] The dry ice preparation, storage and distribution unit comprises one or more combinations of an expansion tank, a dry ice granulator, a dry ice insulation box and conveying equipment and pipelines.

[0044] The application also protects a combined method for desulfurization and decarburization and online blockage removal of blast furnace gas, which is realized by using the combined device for desulfurization and decarburization and online blockage removal of blast furnace gas.

[0045] Step one, temperature adjustment:

[0046] The GGH heat exchanger in the heat exchange temperature control unit is used to adjust the temperature of the blast furnace gas to 60-90 DEG C by using the blast furnace gas and the purified desulfurized clean gas as the medium on both sides of the GGH heat exchanger.

[0047] Step two, desulfurization:

[0048] The temperature-adjusted gas obtained in step one is introduced into the dechlorination pretreatment reaction tower in the desulfurization purification unit, and then passes through the hydrolysis reaction tower and the adsorption reaction tower to obtain the purified desulfurized clean gas.

[0049] Step three, decarburization:

[0050] The purified desulfurized clean gas obtained in step two is introduced into the absorption tower of the decarburization and regeneration unit, and the chemical absorption method is used to absorb the carbon dioxide in the purified desulfurized clean gas in the absorption tower by using alcohol amine solution or ammonia water as the absorbent; the rich liquid after absorbing the carbon dioxide is introduced into the desorption tower for desorption and regeneration to obtain regenerated carbon dioxide gas, and the decarburized purified clean gas is output and stored for standby use.

[0051] Step four, liquefaction:

[0052] The regenerated carbon dioxide gas obtained in step three is introduced into the liquid carbon dioxide preparation unit, and the liquefied rectification process is adopted to prepare the liquid carbon dioxide product of industrial grade or food grade from the regenerated carbon dioxide gas.

[0053] Step five, online blockage cleaning:

[0054] A part of the liquid carbon dioxide product obtained in step four is introduced into the dry ice preparation, storage and distribution unit to prepare dry ice particles, and the other part is output and stored as the liquid carbon dioxide product for standby use; the dry ice particles are sprayed to the orifice plate of the radial flushing reaction tower of the desulfurization purification unit and the tube bundle of the heat exchanger in the heat exchange temperature control unit which are prone to blockage through the dry ice preparation, storage and distribution unit to realize online blockage cleaning.

[0055] Specifically, in step one, the temperature of the blast furnace gas is adjusted to 60-90 DEG C from 30-60 DEG C or greater than or equal to 90 DEG C to obtain the temperature-adjusted gas.

[0056] Specifically, in step two, the removal of Cl- in the dechlorination pretreatment reaction tower is less than or equal to 1 mg / Nm 3 ; the conversion rate of COS in the hydrolysis reaction tower is greater than or equal to 95% when the inorganic sulfur is converted; and the removal of H2S in the adsorption reaction tower is less than or equal to 1 mg / Nm 3 .

[0057] Specifically, in step three, the absorption rate of carbon dioxide in the purified clean gas after desulfurization is ≥ 90%; and the concentration of regenerated carbon dioxide in the desorption tower is ≥ 95%.

[0058] Specifically, in step five, the particle size of the dry ice particles is 1-3 mm.

[0059] Compared with the prior art, the present application has the following technical effects:

[0060] (I) The device in the present application uses the by-product of decarburization and regeneration, i.e., high-concentration carbon dioxide gas, to prepare liquid carbon dioxide products and dry ice products, thereby reducing carbon dioxide emissions, achieving carbon emission reduction and carbon dioxide resource utilization, generating additional economic benefits, and reducing the overall cost of blast furnace gas purification treatment; at the same time, the dry ice products are used to clean the blockage of the tube bundle of the heat exchanger and the orifice plate of the radial flushing reaction tower online, ensuring the continuity of production and achieving the unity of economic benefits and environmental benefits of the enterprise.

[0061] (II) The device in the present application realizes deep removal of sulfur content and effective removal of carbon dioxide in blast furnace gas through combined desulfurization and decarburization, has high desulfurization efficiency, can control the total sulfur content in blast furnace gas at a very low level, meets the requirements of the steel industry for ultra-low emission of gas purification degree, and provides clean energy for subsequent gas utilization. The total sulfur in blast furnace gas is removed to 10 mg / Nm 3 After desulfurization and decarburization, the carbon dioxide content in the gas is reduced from 20-24% to 1-2%, which significantly reduces carbon emissions and effectively improves the purification efficiency.

[0062] (III) The device in the present application effectively solves the problem of equipment blockage through online cleaning with dry ice, does not need to be shut down for offline cleaning, greatly improves the running stability of the device, reduces the time and cost of frequent parking maintenance due to equipment blockage, prolongs the service life of the device, and improves the production efficiency. The dry ice particles low-temperature brittle deposition, the cleaning efficiency is improved, the desulfurization and purification unit operation cycle is prolonged by 3-5 times. Avoiding the production interruption caused by offline cleaning, the annual maintenance cost is reduced by 50%.

[0063] (IV) The device in the present application can improve the calorific value of blast furnace gas. The main combustible component in blast furnace gas is CO of more than 20%, and after removing carbon dioxide, the CO concentration is higher, and the calorific value of blast furnace gas is higher. The absorption rate of carbon dioxide is ≥ 90%, and the calorific value of blast furnace gas is increased by 5%-8%.

[0064] (V) The device in the application is simple and compact, the whole device integrates desulfurization, decarburization, carbon dioxide product preparation and online blockage cleaning and the like, optimizes the process flow, reduces the equipment floor area, and lowers the investment cost and operation energy consumption, and has good feasibility and popularization.

[0065] (VI) The method in the application solves the defects of the existing blast furnace gas desulfurization and decarburization technology, such as complex process flow, prominent equipment blockage problem and limited removal effect, realizes deep purification and resource utilization of the blast furnace gas, meets the needs of ultra-low emission and carbon emission reduction of the steel industry, realizes resource utilization of carbon dioxide, and forms a closed loop of pollution reduction and carbon reduction.

[0066] (VII) The method in the application realizes optimal decarburization effect while ensuring efficient desulfurization through coupling optimization of the desulfurization and decarburization process, and improves the gas purification efficiency and quality.

[0067] (VIII) The method in the application realizes effective cleaning of the blocked equipment by using dry ice for online blockage cleaning, and guarantees stable operation of the device. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 It is a schematic diagram of the overall structure of the device of the application.

[0069] Figure 2 It is a schematic diagram of the axial cross-sectional structure of the radial flushing reaction tower in the device of the application.

[0070] Figure 3 It is a schematic diagram of the lateral cross-sectional structure of the radial flushing reaction tower in the device of the application.

[0071] Fig. 4(a) is a partial enlarged actual photograph of the outer hole cylinder in the device of the application in a clean state.

[0072] Fig. 4(b) is a partial enlarged actual photograph of the outer hole cylinder in the device of the application in a completely blocked state.

[0073] Fig. 5(a) is an actual photograph of the tube bundle of the heat exchanger in the device of the application in a clean state.

[0074] Fig. 5(b) is an actual photograph of the tube bundle of the heat exchanger in the device of the application in a serious scaling state.

[0075] The meanings of the respective reference numerals in the drawings are as follows: 1 - heat exchange temperature control unit, 2 - desulfurization purification unit, 3 - decarburization and regeneration unit, 4 - liquid carbon dioxide preparation unit, 5 - dry ice preparation, storage and distribution unit, 6 - radial flushing reaction tower, 7 - filler.

[0076] 201 - dechlorination pretreatment reaction tower, 202 - hydrolysis reaction tower, 203 - adsorption reaction tower.

[0077] 301 - absorption tower, 302 - absorption tower and desorption tower auxiliary equipment, 303 - desorption tower.

[0078] 601 - radial flushing reaction tower shell, 602 - mounting cavity, 603 - bottom plate, 604 - outer hole cylinder, 605 - inner hole cylinder, 606 - outer hole cylinder flushing port, 607 - outer hole cylinder flushing pipeline, 608 - first introduction hose, 609 - outer hole cylinder nozzle, 610 - inner hole cylinder flushing port, 611 - inner hole cylinder flushing pipeline, 612 - second introduction hose, 613 - inner hole cylinder nozzle, 614 - outer tube lower end buffer spring, 615 - outer tube upper end buffer spring, 616 - axial up-down reciprocating assembly, 617 - outer tube support guide, 618 - driving motor, 619 - inner tube support guide, 620 - filler filling cavity, 621 - outer hole cylinder gas passage, 622 - inner hole cylinder gas passage, 623 - reaction gas first passage, 624 - reaction gas second passage, 625 - reaction gas third passage, 626 - sealing element, 627 - rotary joint, 628 - outer hole cylinder nozzle, 629 - inner hole cylinder nozzle, 630 - protective sleeve, 631 - outer hole cylinder flushing pipeline branch pipe.

[0079] 60201 - axial upper segment mounting cavity, 60202 - axial lower segment mounting cavity.

[0080] The specific content of the present application is further described in detail below in combination with the drawings and examples. DETAILED DESCRIPTION

[0081] It should be noted that all the devices, parts and materials in the present application, if not specially stated, all adopt the devices, parts and materials known in the prior art, for example, the absorption tower adopts the known absorption tower, the driving motor adopts the known driving motor, the compressor adopts the known compressor, the ice machine adopts the known ice machine, the pre-cooler adopts the known pre-cooler, the first introduction hose and the second introduction hose both adopt the known hose, the filler adopts the known filler, the calcium-based or alumina-based dechlorination agent adopts the known calcium-based or alumina-based dechlorination agent, the γ-Al2O3-based hydrolysis agent adopts the known γ-Al2O3-based hydrolysis agent, and the iron oxide-based or activated carbon-based adsorbent adopts the known iron oxide-based or activated carbon-based adsorbent.

[0082] The technical idea of the present application is: first, adjusting the temperature of the blast furnace dust and the blast furnace gas after the blast furnace gas pressure turbine generator, then using the "pretreatment + hydrolysis + dry adsorption desulfurization" technology, which can solve the problems of the traditional wet hydrogen sulfide removal process, such as large alkali consumption, wastewater discharge, equipment corrosion, complex reaction process, difficulty in forming elemental sulfur, complex operation, heat value drop caused by increased water content, and the need to set up a booster device due to high system resistance, etc. At the same time, this technology can protect the hydrolysis catalyst from being damaged by the high temperature bag dust and excessive impurities due to the setting of the pretreatment agent.

[0083] The technology has the following advantages:

[0084] First, it has mature and stable desulfurizing agent and hydrolysis agent for long-term reliable operation. Compared with existing catalysts with regeneration function on the market, it has higher reliability and stronger stability, avoiding problems such as low regeneration efficiency and short service life.

[0085] Second, the dechlorination pretreatment device can adapt to the complex working conditions of the blast furnace, and is simple and reliable, with low energy consumption and no wastewater generation, effectively improving the problems of complex system, high energy consumption and large amount of wastewater generation in other fine desulfurization pretreatment devices.

[0086] Third, the core equipment such as hydrolysis tower and desulfurization tower adopts advanced radial fixed bed structure, which has the advantages of uniform flow field, small bed pressure drop, low equipment energy consumption, high space velocity, high treatment capacity and easy large-scale production.

[0087] Fourth, the standardization and modularization design concept can greatly improve design efficiency, reduce construction difficulty and save material cost.

[0088] Chemical absorption method for decarburization technology (including alcohol amine method, ammonia method, etc.) has been demonstrated in power and coal chemical industry for flue gas decarburization of coal-fired boiler, and blast furnace gas decarburization has not been specially concerned. After desulfurization of blast furnace gas, it is relatively clean, and can be further treated by decarburization to completely realize pollution reduction and carbon reduction. The high-concentration carbon dioxide gas regenerated after decarburization of blast furnace gas can be used to prepare industrial or food-grade liquid carbon dioxide products and dry ice products, etc. The dry ice particles can be used to online clear the hole plate and heat exchanger tube bundle of the radial flushing reaction tower, ensuring the long-term stable operation of the desulfurization purification device.

[0089] In addition to the dry ice online cleaning facility, other online cleaning technologies such as ultrasonic cleaning, jet cleaning or vibration cleaning can also be considered. Ultrasonic cleaning is to use the vibration effect of ultrasonic waves to loosen and fall off the blockage; jet cleaning is to use high-speed fluid jet to impact the blockage site to wash away the blockage; vibration cleaning is to use mechanical vibration to produce relative displacement between the equipment parts and the blockage to remove the blockage. These cleaning methods have their own advantages and application scope, but they are not suitable for online cleaning of the blast furnace gas purification device at present due to the reasons of equipment structure, blockage properties, operating conditions or equipment operation stability.

[0090] In the present application, the full name of GGH heat exchanger is Gas-Gas Heater, and the GGH heat exchanger refers to a gas-gas heat exchanger. The gas-gas heat exchanger used in the present application is a commonly used gas-gas heat exchanger known in the art, which is used for heat exchange between high-temperature coal gas and low-temperature coal gas.

[0091] In the present application, the orifice plate includes an outer orifice cylinder 604 and an inner orifice cylinder 605, and the orifice plate uses an orifice plate known in the art.

[0092] In the present application, the working principle of dry ice cleaning is that when dry ice particles contact the surface to be cleaned, several key processes occur:

[0093] First, temperature effect: because the sublimation temperature of dry ice particles is extremely low (about -78.5℃), the dry ice particles will rapidly cool the dirt and coating on the surface to be cleaned, causing the dirt and coating on the surface to be cleaned to become weak and shrink, thereby being more easily removed.

[0094] Second, expansion effect: when the dry ice particles contact the surface to be cleaned, the dry ice particles rapidly sublimate into gaseous carbon dioxide, generating a gas impact that helps to blow away the impurities on the surface to be cleaned.

[0095] Third, impact effect: dry ice particles have high-speed impact capability, which can break the dirt, coating and deposits on the surface to be cleaned from the surface.

[0096] According to the above technical solution, the specific embodiments of the present application are given below. It should be noted that the present application is not limited to the following specific embodiments, and any equivalent transformation based on the technical solution of the present application falls within the protection scope of the present application.

[0097] Example 1:

[0098] The present embodiment gives a combined device for blast furnace gas desulfurization and decarburization and online cleaning, as shown in Figure 1 Figure 1, which includes a heat exchange temperature control unit 1, the discharge port of the heat exchange temperature control unit 1 is in communication with the feed port of a desulfurization and purification unit 2, and the discharge port of the desulfurization and purification unit 2 is in communication with the feed port of a decarburization and regeneration unit 3.

[0099] The desulfurization and purification unit 2 comprises a dechlorination pretreatment reaction tower 201, a hydrolysis reaction tower 202 and an adsorption reaction tower 203 connected in sequence from front to back.

[0100] The dechlorination pretreatment reaction tower 201, the hydrolysis reaction tower 202 and the adsorption reaction tower 203 are respectively a radial flushing reaction tower 6.

[0101] The discharge port of the decarburization and regeneration unit 3 is connected with the feed port of the liquid carbon dioxide preparation unit 4, and the discharge port of the liquid carbon dioxide preparation unit 4 is connected with the feed port of the dry ice preparation storage and distribution unit 5.

[0102] The discharge port of the dry ice preparation storage and distribution unit 5 is also connected with the flushing port of the heat exchange temperature control unit 1.

[0103] The discharge port of the dry ice preparation storage and distribution unit 5 is also connected with the outer hole barrel flushing port 606 of the dechlorination pretreatment reaction tower 201, the hydrolysis reaction tower 202 and the adsorption reaction tower 203 respectively.

[0104] The discharge port of the dry ice preparation storage and distribution unit 5 is also connected with the inner hole barrel flushing port 610 of the dechlorination pretreatment reaction tower 201, the hydrolysis reaction tower 202 and the adsorption reaction tower 203 respectively.

[0105] As a preferred scheme of the embodiment, as shown in Figures 2 to 3 The radial flushing reaction tower 6 comprises a closed radial flushing reaction tower shell 601, and the internal cavity of the radial flushing reaction tower shell 601 is an installation cavity 602. A bottom plate 603 is horizontally arranged near the bottom in the installation cavity 602, and the outer side wall of the bottom plate 603 is fixedly connected with the inner side wall of the radial flushing reaction tower shell 601 in the circumferential direction. The upper part of the installation cavity 602 of the bottom plate 603 is an axial upper segment installation cavity 60201, and the lower part of the installation cavity 602 of the bottom plate 603 is an axial lower segment installation cavity 60202.

[0106] An outer hole barrel 604 in a cylindrical shape and open at both axial ends is coaxially sleeved in the axial upper segment installation cavity 60201, and the axial upper end of the outer hole barrel 604 is fixedly connected with the top inner wall of the radial flushing reaction tower shell 601, and the axial lower end of the outer hole barrel 604 is fixedly connected with the upper part of the bottom plate 603. An inner hole barrel 605 in a cylindrical shape and open at both axial ends is coaxially sleeved in the outer hole barrel 604, and the axial upper end of the inner hole barrel 605 is fixedly connected with the top inner wall of the radial flushing reaction tower shell 601, and the axial lower end of the inner hole barrel 605 is fixedly connected with the upper part of the bottom plate 603.

[0107] A plurality of outer hole barrel flushing ports 606 are arranged on the radial flushing reaction tower shell 601, and the plurality of outer hole barrel flushing ports 606 are uniformly arranged on the upper part of the bottom plate 603 in the circumferential direction.

[0108] A plurality of outer nozzle flushing pipes 607 are arranged in the axial upper segment mounting cavity 60201, and are uniformly arranged circumferentially between the inner side wall of the radial flushing reaction tower shell 601 and the outer side wall of the outer nozzle 604. Each outer nozzle flushing pipe 607 is arranged along the axial direction, and each outer nozzle flushing pipe 607 is connected to the outer nozzle flushing port 606 through a first introduction hose 608.

[0109] A plurality of outer nozzle injection ports 609 are arranged on each outer nozzle flushing pipe 607 near the side of the outer nozzle 604, and are uniformly arranged along the axial direction. An outer nozzle nozzle 628 is arranged at each outer nozzle injection port 609.

[0110] The radial flushing reaction tower shell 601 is further provided with an inner nozzle flushing port 610 arranged at the axial upper end of the inner nozzle 605.

[0111] An inner nozzle flushing pipe 611 is further arranged in the axial direction in the axial upper segment mounting cavity 60201, and is coaxially sleeved inside the inner nozzle 605. The axial upper end of the inner nozzle flushing pipe 611 is connected to the inner nozzle flushing port 610 through a second introduction hose 612.

[0112] A plurality of inner nozzle injection ports 613 are arranged on the inner nozzle flushing pipe 611 and pass through the side wall in the radial direction. The plurality of inner nozzle injection ports 613 are uniformly arranged along the axial direction. An inner nozzle nozzle 629 is arranged at each inner nozzle injection port 613.

[0113] In this embodiment, the first introduction hose 608 and the second introduction hose 612 have sufficient expansion allowance.

[0114] In this embodiment, the two adjacent outer nozzle flushing pipes 607 are connected through an outer nozzle flushing pipe branch pipe 631 arranged along a circular arc. The outer nozzle flushing pipe branch pipe 631 and the first introduction hose 608 correspond one by one. One outer nozzle flushing port 606 is connected to the two adjacent outer nozzle flushing pipes 607 through the first introduction hose 608 and the outer nozzle flushing pipe branch pipe 631 in turn.

[0115] In this embodiment, the outer nozzle nozzle 628 is a flushing nozzle with an angle of 60-150°. A fan-shaped nozzle with a long strip-shaped flushing area is preferred under general working conditions. A conical nozzle with a circular flushing area can also be selected under better working conditions. The outer nozzle nozzle 628 selected in this embodiment is a fan-shaped nozzle. The fan-shaped nozzle is a commonly used fan-shaped nozzle known in the art.

[0116] In this embodiment, the inner nozzle nozzle 629 is also a fan-shaped nozzle.

[0117] In this embodiment, the axial direction of the radial flushing reaction tower shell 601 is the vertical direction.

[0118] In this embodiment, dry ice particles are sprayed onto the orifice plate and heat exchanger tube bundle surface of the radial flushing reaction tower 6 through the outer hole nozzle 628 and the inner hole nozzle 629. By using the impact force and sublimation characteristics of dry ice particles, the blockage is removed, and online unblocking is achieved. The impurities generated during cleaning are discharged with the coal gas flow, and there is no need to stop for maintenance.

[0119] As a preferred solution of this embodiment, the axial ends of the outer hole flushing pipe 607 are closed, the outer tube lower end buffer spring 614 is arranged at the axial lower end of the outer hole flushing pipe 607, and the axial lower end of the outer tube lower end buffer spring 614 is fixedly connected with the upper part of the bottom plate 603; the outer tube upper end buffer spring 615 is arranged at the axial upper end of the outer hole flushing pipe 607, and the axial upper end of the outer tube upper end buffer spring 615 is fixedly connected with the inner wall of the radial flushing reaction tower shell 601.

[0120] A plurality of axial up-down reciprocating assemblies 616 are also installed on the side wall of the radial flushing reaction tower shell 601, and the axial up-down reciprocating assemblies 616 can enable the outer hole flushing pipe 607 to move up and down along the axial direction.

[0121] A plurality of outer tube support guides 617 are also installed on the inner side wall of the radial flushing reaction tower shell 601, and the plurality of outer tube support guides 617 are uniformly arranged along the axial and circumferential directions, respectively. Each outer tube support guide 617 is connected with the outer hole flushing pipe 607, and the plurality of outer tube support guides 617 can support and guide the outer hole flushing pipe 607 when moving up and down along the axial direction.

[0122] A driving motor 618 is also installed on the radial flushing reaction tower shell 601, and the output shaft of the driving motor 618 is coaxially arranged with the inner hole flushing pipe 611. The inner hole flushing pipe 611 can be driven by the output shaft of the driving motor 618 to rotate around the central axis thereof.

[0123] A plurality of inner tube support guides 619 are also installed on the inner side wall of the inner hole 605, and the plurality of inner tube support guides 619 are uniformly arranged along the axial direction. The plurality of inner tube support guides 619 can support and guide the inner hole flushing pipe 611 when rotating along the circumferential direction.

[0124] In this embodiment, the axial up-down reciprocating assembly 616 is a motor-driven linear reciprocating mechanism, which adopts a commonly used motor-driven linear reciprocating mechanism known in the art.

[0125] In this embodiment, the axial reciprocating assembly 616 and the outer hole cylinder flushing pipe branch pipe 631 are one-to-one corresponding, the axial reciprocating assembly 616 and the outer hole cylinder flushing pipe branch pipe 631 are connected, that is, one axial reciprocating assembly 616 can drive two outer hole cylinder flushing pipes 607 at the same time.

[0126] In this embodiment, the plurality of outer tube supporting guides 617 enable the outer hole cylinder flushing pipe 607 and the outer hole cylinder nozzle 628 to move only along the axial direction; the outer tube supporting guide 617 adopts the commonly used outer tube supporting guide in the art.

[0127] In this embodiment, the outer tube lower end buffer spring 614 and the outer tube upper end buffer spring 615 play a buffering role when the outer hole cylinder flushing pipe 607 moves along the axial direction. At the same time, the outer tube lower end buffer spring 614 and the outer tube upper end buffer spring 615 can also be equivalently replaced by anti-collision blocks or buffer blocks.

[0128] In this embodiment, the plurality of inner tube supporting guides 619 enable the inner hole cylinder flushing pipe 611 to rotate only in the circumferential direction, and the central axis during circumferential rotation is the central axis of the inner hole cylinder flushing pipe 611; the inner tube supporting guide 619 adopts the commonly used inner tube supporting guide 619 in the art.

[0129] In this embodiment, each inner tube supporting guide 619 is connected to the inner side wall of the inner hole cylinder 605, and the connection points are three.

[0130] As a preferred scheme of this embodiment, the cavity between the inner side wall of the outer hole cylinder 604 and the outer side wall of the inner hole cylinder 605 is a filler filling cavity 620, and the filler filling cavity 620 is filled with filler 7.

[0131] The side wall of the outer hole cylinder 604 is also provided with a plurality of outer hole cylinder gas passages 621 that pass through the side wall in the radial direction, and the plurality of outer hole cylinder gas passages 621 are uniformly arranged in the axial direction and the circumferential direction, respectively.

[0132] The side wall of the inner hole cylinder 605 is also provided with a plurality of inner hole cylinder gas passages 622 that pass through the side wall in the radial direction, and the plurality of inner hole cylinder gas passages 622 are uniformly arranged in the axial direction and the circumferential direction, respectively.

[0133] The axial lower end of the radial flushing reaction tower shell 601 is also provided with a reaction gas first passage 623, and the axial upper end of the radial flushing reaction tower shell 601 is also provided with a reaction gas second passage 624; the bottom plate 603 is also provided with a plurality of reaction gas third passages 625, and the plurality of reaction gas third passages 625 are arranged between the outer hole cylinder 604 and the radial flushing reaction tower shell 601.

[0134] The output shaft of the driving motor 618 is also coaxially sleeved with a protective sleeve 630, which is arranged inside the axial lower section mounting cavity 60202.

[0135] The bottom plate 603 is also provided with a sealing member 626, which is arranged at the connection between the output shaft of the driving motor 618 and the inner hole cylinder flushing pipeline 611.

[0136] The connection between the inner hole cylinder flushing pipeline 611 and the second introduction hose 612 is also provided with a rotating joint 627.

[0137] By Figures 4(a) to 5(b) It can be seen that the dry ice particles have good cleaning effect, further ensuring the continuity of production work and realizing the online blockage removal of the device.

[0138] In this embodiment, the reaction gas first passage 623 is a reaction gas inlet, and the reaction gas second passage 624 is a reaction gas outlet. The reaction gas entering the dechlorination pretreatment reaction tower 201 refers to the blast furnace gas after temperature adjustment by the heat exchange temperature control unit 1, i.e., the blast furnace gas with a temperature of 60-90℃.

[0139] In this embodiment, the rotating joint 627 ensures that the second introduction hose 612 does not move, and the inner hole cylinder flushing pipeline 611 rotates around its central axis. The rotating joint 627 is a commonly used rotating joint 627 known in the art.

[0140] In this embodiment, the sealing member 626 not only ensures the circumferential rotation of the inner hole cylinder flushing pipeline 611 around its axis, but also ensures the sealing reliability of the connection between the inner hole cylinder flushing pipeline 611 and the output shaft of the driving motor 618 on the bottom plate 603. The sealing member 626 is a commonly used sealing member 626 known in the art.

[0141] In this embodiment, the protective sleeve 630 ensures that the output shaft of the driving motor 618 does not come into contact with the reaction gas.

[0142] As a preferred scheme of this embodiment, the feed inlet of the heat exchange temperature control unit 1 is in communication with the blast furnace gas delivery pipeline.

[0143] The heat exchange temperature control unit 1 comprises a heat exchanger; the heat exchanger comprises one or more combinations of a GGH heat exchanger, a heater and a cooler.

[0144] The reaction gas first passage 623 of the dechlorination pretreatment reaction tower 201 is connected with the discharge port of the heat exchange temperature control unit 1; the dechlorination pretreatment reaction tower 201 is internally provided with calcium-based or alumina-based dechlorination agents to adsorb hydrogen chloride impurities in the coal gas to remove Cl-; the hydrolysis reaction tower 202 is internally provided with γ-Al2O3-based hydrolysis agents to convert organic sulfur into inorganic sulfur; the adsorption reaction tower 203 is internally provided with iron oxide-based or activated carbon-based adsorbents to remove inorganic sulfur, so as to realize desulfurization and purification of the coal gas, and obtain purified coal gas after desulfurization and purification.

[0145] The decarburization and regeneration unit 3 comprises an absorption tower 301, the feed port of the absorption tower 301 is connected with the reaction gas second passage 624 of the adsorption reaction tower 203, the discharge port of the absorption tower 301 is connected with the feed port of the absorption tower and desorption tower auxiliary equipment 302, the discharge port of the absorption tower and desorption tower auxiliary equipment 302 is connected with the feed port of the desorption tower 303, and the discharge port of the desorption tower 303 is connected with the feed port of the liquid carbon dioxide preparation unit 4.

[0146] The absorption tower and desorption tower auxiliary equipment 302 comprises one or more combinations of a cooling tower, a lean-liquid and rich-liquid heat exchanger, and a washing tower.

[0147] The liquid carbon dioxide preparation unit 4 comprises one or more combinations of a compressor, an ice machine, a pre-cooler, a rectifying tower, a condenser, a super-cooler, and a product storage tank.

[0148] The dry ice preparation, storage and distribution unit 5 comprises one or more combinations of an expansion tank, a dry ice granulator, a dry ice insulation tank, and conveying equipment and pipelines.

[0149] In the embodiment, the blast furnace gas conveying pipeline is a commonly used blast furnace gas conveying pipeline known in the art, the blast furnace gas conveying pipeline conveys blast furnace gas, and the blast furnace gas is blast furnace gas generated during production and processing of a steel enterprise.

[0150] In the embodiment, the conveying equipment and pipelines are commonly used conveying equipment and pipelines known in the art.

[0151] In the embodiment, the heat exchange temperature control unit 1 is used to adjust the temperature of the blast furnace gas, the blast furnace gas temperature is controlled at 60-90°C by adjusting the steam or cooling medium flow, and suitable temperature conditions are provided for subsequent desulfurization reactions.

[0152] In the embodiment, the dechlorination pretreatment reaction tower 201, the hydrolysis reaction tower 202, and the adsorption reaction tower 203 are all dechlorination pretreatment reaction towers, hydrolysis reaction towers, and adsorption reaction towers known in the art.

[0153] In the embodiment, the decarburization and regeneration unit 3 realizes the purposes of decarburization and carbon dioxide regeneration. The calorific value of the coal gas after removal of carbon dioxide is increased, and the coal gas can be used as fuel for subsequent use.

[0154] In the embodiment, the liquid carbon dioxide preparation unit 4 is used to prepare industrial or food-grade liquid carbon dioxide products, so as to realize the resource utilization of carbon dioxide.

[0155] In the embodiment, the dry ice preparation storage and distribution unit 5, the pipeline and the nozzle are used to spray dry ice particles to the orifice plate of the radial flushing reaction tower 6 of the desulfurization and purification unit 2 and the pipe bundle of the heat exchanger in the heat exchange and temperature control unit 1, and the impurities such as dust, tar and crystalline salt attached to the surface of the equipment are brittle, shrunk, broken and blown away by the low temperature and impact of the dry ice, so as to realize online unblocking, solve the equipment blocking problem and guarantee the long-period stable operation of the desulfurization and purification device. The pipeline adopts the commonly used pipeline in the art, and the nozzle adopts the commonly used nozzle in the art.

[0156] In the embodiment, the discharge port of the desulfurization and purification unit 2 can also be connected to the shell inlet of the GGH heat exchanger in the heat exchange and temperature control unit 1, and the shell outlet of the GGH heat exchanger in the heat exchange and temperature control unit 1 can also be connected to the feed inlet of the absorption tower 301 in the decarburization and regeneration unit 3; the connection mode can not only cool the desulfurized and purified clean gas to below 40℃, so as to meet the temperature requirement of the desulfurized and purified clean gas entering the decarburization and regeneration unit 3, but also heat the blast furnace gas of the heat exchange and temperature control unit 1, so as to meet the temperature requirement of entering the desulfurization and purification unit 2, thereby realizing the full utilization of heat resources.

[0157] The working principle of the radial flushing reaction tower 6 in the embodiment is that the reaction gas enters the outer cavity composed of the radial flushing reaction tower shell 601 and the outer hole cylinder 604 from the reaction gas first passage 623 and the reaction gas third passage 625 in sequence from front to back, then passes through the outer hole cylinder gas passage 621 on the outer hole cylinder 604, the filler 7 and the inner hole cylinder gas passage 622 on the inner hole cylinder 605 in sequence horizontally, and finally the reaction gas flows to the next section from the reaction gas second passage 624.

[0158] The flushing principle of the outer hole cylinder 604 in the radial flushing reaction tower 6 is that the flushing gas or liquid flows to the outer hole cylinder flushing pipeline 607 from the outer hole cylinder flushing port 606 through the first introduction hose 608 and the outer hole cylinder flushing pipeline branch pipe 631, then is distributed to each outer hole cylinder nozzle 628 from the outer hole cylinder flushing pipeline 607, and is sprayed to the surface of the outer hole cylinder 604 from the outer hole cylinder nozzle 628 to perform cleaning, and the flushing gas or liquid forms a long strip-shaped flushing area on the surface of the outer hole cylinder 604 in the horizontal direction; after the up-down reciprocating assembly 616 is started, the outer hole cylinder flushing pipeline 607 can move up and down along the axial direction, and then the outer hole cylinder nozzle 628 moves up and down along the axial direction, so that the long strip-shaped flushing area forms a plane area, and the flushing area is improved.

[0159] The flushing principle of the inner hole cylinder 605 in the radial flushing reaction tower 6 is that the flushing gas or liquid flows from the inner hole cylinder flushing port 610 to the inner hole cylinder flushing pipeline 611 through the second introduction hose 612, and then is distributed to each inner hole cylinder nozzle 629 from the inner hole cylinder flushing pipeline 611, and then is sprayed to the surface of the inner hole cylinder 605 from the inner hole cylinder nozzle 629 to clean, and the flushing gas or liquid forms a long strip flushing area in the vertical direction on the surface of the inner hole cylinder 605; after the driving motor 618 is started, the rotation of the output shaft of the driving motor 618 drives the inner hole cylinder flushing pipeline 611 and the inner hole cylinder nozzle 629 to rotate circumferentially, so that the long strip flushing area in the vertical direction is flushed in a whole circle area.

[0160] Embodiment 2

[0161] The embodiment provides a combined method for desulfurization and decarburization and online blockage removal of blast furnace gas, and the combined method is realized by using the combined device for desulfurization and decarburization and online blockage removal of blast furnace gas in the embodiment 1; the method specifically comprises the following steps.

[0162] Step one, temperature adjustment

[0163] The GGH heat exchanger in the heat exchange temperature control unit 1 is used to adjust the temperature of the blast furnace gas to 60-90 DEG C, and the blast furnace gas after temperature adjustment is obtained.

[0164] In the embodiment, the blast furnace gas input into the heat exchange temperature control unit 1 in step one is the blast furnace gas after dust removal and blast furnace gas turbo generator, the temperature of the blast furnace gas is 30-60 DEG C or greater than or equal to 90 DEG C, and the pressure of the blast furnace gas is 10-20 kPa. The blast furnace gas turbo generator is a commonly used blast furnace gas turbo generator known in the art, which is referred to as TRT.

[0165] In step one, the temperature of the blast furnace gas is adjusted from 30-60 DEG C or greater than or equal to 90 DEG C to 60-90 DEG C, and the blast furnace gas after temperature adjustment is obtained. The temperature of the clean gas after desulfurization and purification in step two is 60-90 DEG C; when the temperature of the blast furnace gas input in step one is 30-60 DEG C, the clean gas after desulfurization and purification is used to heat the blast furnace gas to fully utilize the heat of the blast furnace gas, and the insufficient part is supplemented by the heater, the temperature of the blast furnace gas is adjusted to 60-90 DEG C, and the heat source of the heater is waste steam or waste heat water and other waste heat resources in the factory area; when the temperature of the blast furnace gas is greater than or equal to 90 DEG C, the cooler in the heat exchange temperature control unit 1 is used to adjust the temperature of the blast furnace gas to 60-90 DEG C, and the cold source of the cooler is the circulating cooling water in the factory area. Further, in the embodiment, the temperature of the blast furnace gas input in step one is greater than or equal to 90 DEG C, and the cooler is used for temperature reduction.

[0166] Step two, desulfurization:

[0167] The temperature-adjusted coal gas obtained in step one is introduced into a dechlorination pretreatment reaction tower 201 in a desulfurization purification unit 2, and then passes through a hydrolysis reaction tower 202 and an adsorption reaction tower 203 to obtain purified clean coal gas after desulfurization purification.

[0168] In step two, the removal of Cl- in the dechlorination pretreatment reaction tower 201 is ≤1 mg / Nm 3 ; the conversion rate of COS in the hydrolysis reaction tower 202 is ≥95% when inorganic sulfur is converted; and the removal of H2S in the adsorption reaction tower 203 is ≤1 mg / Nm 3 .

[0169] In this embodiment, the purified clean coal gas after desulfurization purification obtained in step two needs to be cooled to below 40°C before entering the decarburization and regeneration unit 3. There are two ways to cool down. The first way is to introduce the purified clean coal gas after desulfurization purification obtained in step two into a GGH heat exchanger in a heat exchange temperature control unit 1 to be cooled and then enter the decarburization and regeneration unit 3. The temperature of the purified clean coal gas after desulfurization purification is reduced to below 40°C in the GGH heat exchanger to adapt to the carbon dioxide chemical absorption reaction temperature. The second way is to set a cooler before the decarburization and regeneration unit 3. The cooling source of the cooler is the circulating cooling water in the plant area. The temperature of the purified clean coal gas after desulfurization purification obtained in step two is reduced to below 40°C. The cooler is a commonly used cooler known in the art. Further, the cooling method actually used in this embodiment is the second one, i.e., a cooler is set before the decarburization and regeneration unit 3.

[0170] Step three, decarburization:

[0171] The purified clean coal gas after desulfurization purification obtained in step two is introduced into an absorption tower 301 of a decarburization and regeneration unit 3. An alcohol amine solution or ammonia water is used as an absorbent to absorb carbon dioxide in the purified clean coal gas after desulfurization purification in the absorption tower 301 by using a chemical absorption method. The rich liquid after absorbing carbon dioxide is introduced into a desorption tower 303 to be regenerated by desorption to obtain regenerated carbon dioxide gas, and the purified clean coal gas after decarburization is output and stored for standby use.

[0172] In step three, when the carbon dioxide in the purified clean coal gas after desulfurization purification is absorbed, the carbon dioxide absorption rate is ≥90%; and when the desorption regeneration is carried out in the desorption tower 303, the regenerated carbon dioxide concentration is ≥95%.

[0173] Step four, liquefaction:

[0174] The regenerated carbon dioxide gas obtained in step three is introduced into a liquid carbon dioxide preparation unit 4. A liquefaction rectification process is used to prepare industrial-grade or food-grade liquid carbon dioxide products from the regenerated carbon dioxide gas.

[0175] In this embodiment, the liquefaction rectification process used in step four to make the liquid carbon dioxide product into industrial grade or food grade carbon dioxide product is the commonly used liquefaction rectification process known in the art.

[0176] Step five, online cleaning:

[0177] A part of the liquid carbon dioxide product obtained in step four is extracted and fed into the dry ice preparation, storage and distribution unit 5 to make dry ice particles, and the other part is output as a liquid carbon dioxide product for storage and standby; the dry ice particles are sprayed by the dry ice preparation, storage and distribution unit 5 to the orifice plate of the radial flushing reaction tower 6 of the desulfurization and purification unit 2 and the tube bundle of the heat exchanger in the heat exchange and temperature control unit 1, etc. which are easy to be blocked, to realize online cleaning.

[0178] In step five, the particle size of the dry ice particles is 1-3 mm.

[0179] In this embodiment, the liquid carbon dioxide product is made into dry ice particles by a dry ice forming machine in step five. The liquid carbon dioxide enters the dry ice forming machine through a pipeline, throttles, depressurizes and cools to form a powder-like solid, and then is extruded into granular dry ice by a grinding tool. The dry ice forming machine is the commonly used dry ice forming machine known in the art.

[0180] In this embodiment, the spraying pressure in step five is 1-2 MPa.

[0181] In this embodiment, the dry ice used to clean the orifice plate of the dechlorination pretreatment reaction tower 201, the hydrolysis reaction tower 202 and the adsorption reaction tower 203 in the desulfurization and purification unit 2 and the heat exchanger in the heat exchange and temperature control unit 1 is recycled in the entire combined device. The dry ice particles gasify during the cleaning process and then return to the purified coal gas after desulfurization, and finally enter the decarburization and regeneration unit 3 from the reaction gas second passage 624 of the adsorption reaction tower 203, are reabsorbed and captured in the decarburization and regeneration unit 3, and are used after being made into dry ice particles again in the liquid carbon dioxide preparation unit 4 and the dry ice preparation, storage and distribution unit 5.

Claims

1. A combined device for desulfurization, decarbonization and online unblocking of blast furnace gas, comprising a heat exchange and temperature control unit (1), wherein the outlet of the heat exchange and temperature control unit (1) is connected to the inlet of the desulfurization and purification unit (2), and the outlet of the desulfurization and purification unit (2) is connected to the inlet of the decarbonization and regeneration unit (3). The desulfurization purification unit (2) comprises a dechlorination pretreatment reaction tower (201), a hydrolysis reaction tower (202), and an adsorption reaction tower (203) connected sequentially from front to back; characterized in that: The dechlorination pretreatment reaction tower (201), hydrolysis reaction tower (202) and adsorption reaction tower (203) are respectively equipped with radial flushing reaction tower (6); The outlet of the decarbonization and regeneration unit (3) is connected to the inlet of the liquid carbon dioxide preparation unit (4), and the outlet of the liquid carbon dioxide preparation unit (4) is connected to the inlet of the dry ice preparation, storage and distribution unit (5). The outlet of the dry ice preparation, storage and distribution unit (5) is also connected to the flushing port of the heat exchange and temperature control unit (1); The outlet of the dry ice preparation, storage and distribution unit (5) is also connected to the outer tube flushing port (606) of the dechlorination pretreatment reaction tower (201), the hydrolysis reaction tower (202) and the adsorption reaction tower (203); The outlet of the dry ice preparation, storage and distribution unit (5) is also connected to the inner tube flushing port (610) of the dechlorination pretreatment reaction tower (201), the hydrolysis reaction tower (202) and the adsorption reaction tower (203).

2. The combined device for blast furnace gas desulfurization, decarbonization, and online unblocking as described in claim 1, characterized in that, The radial flushing reaction tower (6) includes a closed radial flushing reaction tower shell (601), the internal cavity of the radial flushing reaction tower shell (601) is a mounting cavity (602), a base plate (603) is horizontally arranged near the bottom in the mounting cavity (602), and the outer side wall of the base plate (603) is fixedly connected to the inner side wall of the radial flushing reaction tower shell (601) in the circumferential direction; the mounting cavity (602) at the upper part of the base plate (603) is an axial upper section mounting cavity (60201), and the mounting cavity (602) at the lower part of the base plate (603) is an axial lower section mounting cavity (60202); A cylindrical outer bore (604) with both axial ends open is coaxially fitted inside the axial upper section mounting cavity (60201). The upper axial end of the outer bore (604) is fixedly connected to the top inner wall of the radial flushing reaction tower shell (601), and the lower axial end of the outer bore (604) is fixedly connected to the upper part of the base plate (603). A cylindrical inner bore (605) with both axial ends open is also coaxially fitted inside the outer bore (604). The upper axial end of the inner bore (605) is fixedly connected to the top inner wall of the radial flushing reaction tower shell (601), and the lower axial end of the inner bore (605) is fixedly connected to the upper part of the base plate (603). The radial flushing reaction tower shell (601) is also provided with a plurality of external cylinder flushing ports (606), which are evenly distributed circumferentially on the upper part of the bottom plate (603); The axial upper section mounting cavity (60201) is also provided with a plurality of external cylinder flushing pipes (607). The plurality of external cylinder flushing pipes (607) are evenly arranged circumferentially between the inner side wall of the radial flushing reaction tower shell (601) and the outer side wall of the external cylinder (604). Each external cylinder flushing pipe (607) is arranged axially, and each external cylinder flushing pipe (607) is connected to the external cylinder flushing port (606) through the first inlet hose (608). Each of the external cylinder flushing pipes (607) is provided with a plurality of radially penetrating external cylinder nozzles (609) on the side near the external cylinder (604). The plurality of external cylinder nozzles (609) are evenly distributed along the axial direction, and an external cylinder nozzle (628) is installed at each external cylinder nozzle (609). The radial flushing reaction tower shell (601) is also provided with an inner tube flushing port (610), which is located at the upper axial end of the inner tube (605). An inner bore flushing pipe (611) is also provided axially in the upper section of the mounting cavity (60201). The inner bore flushing pipe (611) is coaxially fitted inside the inner bore (605). The upper axial end of the inner bore flushing pipe (611) is connected to the inner bore flushing port (610) through a second inlet hose (612). The inner tube flushing pipe (611) is also provided with multiple inner tube nozzles (613) that penetrate the side wall radially. The multiple inner tube nozzles (613) are evenly distributed along the axial direction, and an inner tube nozzle (629) is installed at each inner tube nozzle (613).

3. The combined device for blast furnace gas desulfurization, decarbonization, and online unblocking as described in claim 2, characterized in that, The axial ends of the external tube flushing pipe (607) are closed, and multiple axial reciprocating components (616) are installed on the side wall of the radial flushing reaction tower shell (601). The axial reciprocating components (616) enable the external tube flushing pipe (607) to move up and down along the axial direction. The inner wall of the radial flushing reaction tower shell (601) is also equipped with a plurality of outer tube support guides (617). The plurality of outer tube support guides (617) are evenly distributed along the axial and circumferential directions respectively. Each outer tube support guide (617) is connected to the outer tube flushing pipe (607). The plurality of outer tube support guides (617) can support and guide the outer tube flushing pipe (607) when it reciprocates up and down along the axial direction. The radial flushing reaction tower shell (601) is also equipped with a drive motor (618). The output shaft of the drive motor (618) is coaxially arranged with the inner cylinder flushing pipe (611). The inner cylinder flushing pipe (611) can be driven by the output shaft of the drive motor (618) to achieve circumferential rotation around its own central axis. The inner wall of the inner cylinder (605) is also equipped with a plurality of inner tube support guides (619). The plurality of inner tube support guides (619) are evenly arranged along the axial direction. The plurality of inner tube support guides (619) can support and guide the inner cylinder flushing pipe (611) when it rotates in the circumferential direction.

4. The combined device for blast furnace gas desulfurization, decarbonization, and online unblocking as described in claim 3, characterized in that, The cavity between the inner wall of the outer bore (604) and the outer wall of the inner bore (605) is a filler cavity (620), and the filler cavity (620) is filled with filler (7). The outer cylinder (604) is further provided with a plurality of radially penetrating outer cylinder gas channels (621) on its side wall, and the plurality of outer cylinder gas channels (621) are evenly distributed along the axial and circumferential directions respectively; The inner cylinder (605) is also provided with a plurality of radially penetrating gas channels (622) on its sidewall, and the plurality of gas channels (622) are evenly distributed along the axial and circumferential directions respectively. The radial flushing reaction tower shell (601) is provided with a first reaction gas channel (623) at its lower axial end and a second reaction gas channel (624) at its upper axial end; the bottom plate (603) is provided with a plurality of third reaction gas channels (625), which are arranged between the outer cylinder (604) and the radial flushing reaction tower shell (601); A swivel joint (627) is also installed at the connection between the inner tube flushing pipe (611) and the second inlet hose (612).

5. The combined device for blast furnace gas desulfurization, decarbonization, and online unblocking as described in claim 1, characterized in that, The inlet of the heat exchange temperature control unit (1) is connected to the blast furnace gas transmission pipeline; The heat exchange temperature control unit (1) includes a heat exchanger; the heat exchanger includes one or more combinations of a GGH heat exchanger, a heater, and a cooler; The first channel (623) of the dechlorination pretreatment reaction tower (201) is connected to the outlet of the heat exchange and temperature control unit (1); the dechlorination pretreatment reaction tower (201) is equipped with a calcium-based or alumina-based dechlorinating agent to adsorb hydrogen chloride impurities in the coal gas to remove Cl-; the hydrolysis reaction tower (202) is equipped with a γ-Al2O3-based hydrolysant to convert organic sulfur into inorganic sulfur; the adsorption reaction tower (203) is equipped with an iron oxide-based or activated carbon-based adsorbent to remove inorganic sulfur, thereby achieving desulfurization and purification of the coal gas and obtaining clean coal gas after desulfurization and purification. The decarbonization and regeneration unit (3) includes an absorption tower (301), the inlet of the absorption tower (301) is connected to the second reaction gas channel (624) of the adsorption reaction tower (203), the outlet of the absorption tower (301) is connected to the inlet of the absorption tower and desorption tower auxiliary equipment (302), the outlet of the absorption tower and desorption tower auxiliary equipment (302) is connected to the inlet of the desorption tower (303), and the outlet of the desorption tower (303) is connected to the inlet of the liquid carbon dioxide preparation unit (4). The absorption tower and desorption tower auxiliary equipment (302) include one or more combinations of cooling tower, lean and rich liquid heat exchanger and scrubbing tower; The liquid carbon dioxide preparation unit (4) includes one or more combinations of a compressor, an ice machine, a precooler, a distillation column, a condenser, a subcooler, and a product storage tank; The dry ice preparation, storage and distribution unit (5) includes one or more combinations of an expansion chamber, a dry ice pellet mill, a dry ice insulation box and conveying equipment and pipelines.

6. A combined method for desulfurization, decarbonization, and online unblocking of blast furnace gas, characterized in that, This method employs a combined device for blast furnace gas desulfurization, decarbonization, and online unblocking as described in any one of claims 1 to 5; the method specifically includes the following steps: Step 1, Adjust the temperature: Using the GGH heat exchanger in the heat exchange temperature control unit (1), the media on both sides of the GGH heat exchanger are blast furnace gas and desulfurized purified gas, respectively, to adjust the temperature of the blast furnace gas to 60℃~90℃, and obtain the gas after temperature adjustment. Step 2, Desulfurization: The coal gas obtained in step one after temperature adjustment is passed into the dechlorination pretreatment reaction tower (201) in the desulfurization purification unit (2), and then through the hydrolysis reaction tower (202) and the adsorption reaction tower (203) to obtain the desulfurized and purified coal gas. Step 3, Decarbonization: The desulfurized and purified coal gas obtained in step two is introduced into the absorption tower (301) of the decarbonization and regeneration unit (3). Using amine solution or ammonia water as absorbent, carbon dioxide in the desulfurized and purified coal gas is absorbed in the absorption tower (301) by chemical absorption. The rich liquid after carbon dioxide absorption enters the desorption tower (303) for desorption and regeneration to obtain regenerated carbon dioxide gas. The purified coal gas after decarbonization is output and stored for later use. Step 4, liquefaction: The regenerated carbon dioxide gas obtained in step three is introduced into the liquid carbon dioxide preparation unit (4), and the regenerated carbon dioxide gas is made into industrial-grade or food-grade liquid carbon dioxide products by using liquefaction distillation process. Step 5, online congestion clearing: A portion of the liquid carbon dioxide product obtained in step four is extracted and fed into the dry ice preparation, storage and distribution unit (5) to make dry ice particles, while the other portion is stored as liquid carbon dioxide product output for later use. The dry ice particles are then sprayed into the orifice plate of the radial flushing reaction tower (6) of the desulfurization purification unit (2) and the tube bundle of the heat exchanger in the heat exchange temperature control unit (1) and other easily clogged parts through the dry ice preparation, storage and distribution unit (5) to achieve online unblocking.

7. The online unblocking method of the blast furnace gas desulfurization, decarbonization, and online unblocking combined device as described in claim 6, characterized in that, In step one, the temperature of the blast furnace gas is adjusted from 30℃~60℃ or greater than or equal to 90℃ to 60℃~90℃ to obtain the gas with adjusted temperature.

8. The online unblocking method of the blast furnace gas desulfurization, decarbonization, and online unblocking combined device as described in claim 6, characterized in that, In step two, the removal of Cl- from the dechlorination pretreatment reaction tower (201) is reduced to ≤1 mg / Nm³. 3 The COS conversion rate during inorganic sulfur conversion in the hydrolysis reaction tower (202) is ≥95%; during desulfurization and purification in the adsorption reaction tower (203), H2S is removed to ≤1mg / Nm³. 3 .

9. The online unblocking method of the blast furnace gas desulfurization, decarbonization, and online unblocking combined device as described in claim 6, characterized in that, In step three, when absorbing carbon dioxide from the desulfurized and purified coal gas, the carbon dioxide absorption rate is ≥90%; when desorption and regeneration are carried out in the desorption tower (303), the regenerated carbon dioxide concentration is ≥95%.

10. The online unblocking method of the blast furnace gas desulfurization, decarbonization, and online unblocking combined device as described in claim 6, characterized in that, In step five, the dry ice particles have a particle size of 1–3 mm.

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