Flue gas treatment system for total oxygen kiln

Abstract

The utility model provides a flue gas treatment system for an all-oxygen kiln. The flue gas treatment system comprises a flue gas temperature regulating device, a powder spraying system, a ceramic tube reaction kettle, a reducing agent injection device, an SCR (Selective Catalytic Reduction) denitration reaction kettle, an induced draft fan and a chimney which are sequentially arranged on a main flue along the flow direction of flue gas, the flue gas treatment system further comprises a purified air flue extending from the flue at the rear end of the induced draft fan to the front end of the main flue, and the induced draft fan introduces part of purified flue gas into the main flue as purified air through the purified air flue. The flue gas temperature adjusting device comprises a vertical flue extending downwards from a smoke outlet of the total oxygen kiln and a horizontal flue connected with the vertical flue, and the front end of the horizontal flue is further provided with a sedimentation tank used for depositing flying material crystals in flue gas. And the heat exchanger is arranged on the main flue and behind the horizontal flue. According to the flue gas treatment system, multi-stage cooling is adopted, the flue gas treatment system is suitable for high-temperature flue gas treatment of an all-oxygen kiln, and desulfurization, denitrification, defluorination and dust removal treatment is also carried out on kiln flue gas, so that stable emission of the flue gas reaching the standard is realized.

Description

Technical Field

[0001] The utility model relates to the field of industrial waste gas treatment, in particular to a flue gas treatment system for an all-oxygen kiln. Background Art

[0002] Air pollution pollutants mainly come from substandard industrial waste gas emissions. In recent years, as energy conservation, emission reduction, and environmental protection have received more and more attention, oxyfuel combustion technology has been vigorously developed and is mainly used in glass fiber tank furnaces, cathode ray tube glass melting furnaces, and daily glass melting furnaces.

[0003] In traditional air combustion technology, the oxygen content is only 21%, and about 78% of the nitrogen is heated and discharged unnecessarily. This heat loss can account for more than 30% of energy consumption, causing great waste. Nitrogen and oxygen will generate nitrogen oxides NO at high temperatures. X , causing serious harm to the human body and the environment. At the same time, nitrogen-containing flue gas will also corrode the regenerator, chimney and other equipment, shortening the service life of the melting furnace and increasing costs. The nitrogen content in the oxyfuel combustion technology is very small, which reduces the heat carried away by the exhaust gas, and at the same time, the amount of nitrogen oxides produced is also significantly reduced, reducing environmental pollution.

[0004] In this combustion technology, oxygen plays a role in supporting combustion. So taking natural gas as fuel, for example, the combustion products of full oxygen combustion are mainly H2O and CO2, but the oxygen concentration cannot reach 100%, or a part of air will be mixed in the gas transmission process of the full oxygen kiln, and the flue gas after combustion will also contain a small amount of nitrogen oxides NO. X In addition, due to the high oxygen content in the all-oxygen kiln, the temperature of the flame in the all-oxygen kiln is significantly increased, and the temperature of the flue gas after combustion is much higher than that of other combustion kilns. Therefore, the significant characteristics of the combustion flue gas of the all-oxygen kiln are high temperature and high moisture content. The commonly used flue gas treatment processes and technologies in the prior art are not fully applicable to the treatment of oxygen kiln flue gas. Utility Model Content

[0005] In view of this, an embodiment of the utility model provides a flue gas treatment system for an oxygen kiln to eliminate or improve one or more defects existing in the prior art.

[0006] The technical solution of the utility model is as follows:

[0007] A flue gas treatment system for an oxygen kiln, the flue gas treatment system includes a flue gas temperature control device, a powder spraying system, a ceramic tube reactor, a reducing agent injection device, an SCR denitration reactor, an induced draft fan and a chimney arranged in sequence along the flue gas flow direction on the main flue; the flue gas treatment system also includes a purified air flue extending from the flue at the rear end of the induced draft fan to the front end of the main flue, and the induced draft fan introduces part of the purified flue gas as purified air into the main flue through the purified air flue. The flue gas temperature control device includes: a vertical flue extending downward from the exhaust port of the oxygen kiln and a horizontal flue connected to the vertical flue, the front end of the horizontal flue also having a sedimentation tank for depositing flying material crystals in the flue gas; a heat exchanger arranged on the main flue and located after the horizontal flue.

[0008] In some embodiments, a radiator is provided on the purified air duct from the induced draft fan to the vertical flue to reduce the temperature of the purified air.

[0009] In some embodiments, two heat exchangers are provided, which are connected in parallel and enter the main flue respectively, and the purified air of the diverted part of the induced draft fan is introduced into at least one of the heat exchangers through the bypass flue.

[0010] In some embodiments, the height of the vertical flue is 5m, the bottom end of the vertical flue is connected to the horizontal flue, the sedimentation tank is arranged at the front end of the horizontal flue, and the length of the sedimentation tank is 7.5m.

[0011] In some embodiments, the purified air flue includes a first branch flue introduced into the upper end of the vertical flue and a second branch flue introduced into the front end of the horizontal flue, and both the first branch flue and the second branch flue are provided with purification fans and regulating valves.

[0012] In some embodiments, the heat exchanger is an air-to-air heat exchanger, comprising a main heat exchange unit, a flue gas inlet and outlet, and an air inlet and outlet; the purified air flue introduces the purified air of the induced draft fan diversion part into the air inlet and outlet of the air-to-air heat exchanger through a bypass pipe.

[0013] In some embodiments, a flue conditioning system is arranged in the main flue between the powder spraying system and the ceramic tube reactor to evenly mix the flue gas and the lime powder; the flue conditioning system includes a static mixer and a guide plate unit.

[0014] In some embodiments, the ceramic reactor includes multiple chambers, each of which has multiple vertically arranged ceramic filter tubes, which are vacuum-formed using ceramic fibers and coated with a wear-resistant layer. A dust collection and silo pump conveying system is provided below the ceramic tube reactor, including an ash storage silo unit and a powder collector unit.

[0015] In some embodiments, two induced draft fans are provided and connected in parallel to enter the main flue.

[0016] In some embodiments, the flue gas treatment system is also provided with a flue gas online monitoring system on the main flue or equipment to monitor NO x concentration, SO2 concentration, and oxygen content; the flue gas treatment system also includes a control system.

[0017] According to the fume treatment system for the all-oxygen kiln in the utility model, the beneficial effects that can be obtained include at least:

[0018] 1) The flue gas treatment system adopts multi-stage cooling, which is suitable for the high-temperature flue gas treatment of all-oxygen kilns. It also desulfurizes, denitrates, defluorinates and removes dust from the kiln flue gas to achieve stable emission of flue gas in compliance with standards.

[0019] 2) The flue gas treatment system diverts the purified air from the rear end of the induced draft fan into the vertical flue as dilution air, performs primary air cooling and mixed dilution on the high-temperature flue gas of the oxygen kiln, and can also reduce the oxygen content in the flue gas.

[0020] 3) The flue gas treatment system can reduce the temperature of the purified air by implanting a radiator in the purified air flue. It can also introduce a pre-installed one-in-one-out heat exchanger to divert the purified air to reduce the flue gas temperature. This will be more conducive to the effective reduction of the dilution air temperature, which can not only reduce the use of dilution air, but also reduce the load of the entire system and reduce energy consumption.

[0021] 4) The flue gas treatment system sets up a sedimentation tank in the horizontal flue to ensure that all flying materials are crystallized and deposited in the sedimentation tank.

[0022] 5) The flue gas treatment system adopts a ceramic reactor to remove the residual HF and SO2 in the flue gas for the second time when they pass through the lime filter cake powder layer attached to the outer surface of the ceramic filter element, and at the same time, the dust and other complex components in the flue gas are efficiently removed.

[0023] Additional advantages, purposes, and features of the present invention will be partially described in the following description, and will become partially apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the written description and its claims and the drawings.

[0024] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific description, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for the purpose of illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present invention. In the drawings:

[0026] Figure 1 A schematic diagram of a flue gas treatment system for an oxygen kiln according to an embodiment of the utility model;

[0027] Figure 2 This is a schematic diagram of the structure of a vertical flue, a settling tank and a horizontal flue in one embodiment of the utility model;

[0028] Figure 3 The topological structure diagram of a control system according to an embodiment of the utility model is shown in FIG.

[0029] Among them: 1- all-oxygen kiln; 2- heat exchanger; 3- powder spraying system; 4- ceramic tube reactor; 5- SCR denitration reactor; 5- induced draft fan; 7- chimney; 8- dust collection and warehouse pump delivery system; 9- reducing agent injection device; 10- radiator; 11- purification fan; 12- regulating valve; 101- vertical flue; 102- sedimentation tank; 103- horizontal flue; 104- heat exchanger rear end flue; 105- reducing agent injection flue; 106- non-nitrate flue; 107- purification air flue; 108- bypass flue;

[0030] 109-first branch flue; 110-second branch flue DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in combination with the implementation mode and the accompanying drawings. Here, the schematic implementation mode of the utility model and its description are used to explain the utility model, but are not used as a limitation of the utility model.

[0032] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0033] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0034] The utility model provides a fume treatment system for an oxygen kiln, so as to solve the problems of high temperature and high water vapor of the combustion fume of an oxygen kiln such as a glass kiln in the prior art.

[0035] like Figure 1 As shown, the flue gas treatment system includes a flue gas temperature control device, a powder spraying system 3, a ceramic tube reactor 4, a reducing agent injection device 9, an SCR denitration reactor 5, an induced draft fan 6 and a chimney 7 which are arranged in sequence along the flue gas flow direction on the main flue.

[0036] The flue gas treatment system further includes a purified air flue 107 extending from the flue at the rear end of the induced draft fan 6 to the front end of the main flue, and the induced draft fan 6 introduces part of the purified flue gas as purified air into the main flue through the purified air flue 107;

[0037] The flue gas treatment system of the embodiment of the utility model adopts the process route of "flue gas temperature control device + ceramic high-temperature dust removal, desulfurization and defluorination + SC medium-temperature denitrification". Through multi-stage cooling, the flue gas of the full oxygen kiln is desulfurized, denitrated, defluorinated and dusted to meet the ideal operating temperature of equipment in different process sections, so as to achieve stable emission of flue gas that meets the standards.

[0038] The flue gas temperature control device of the embodiment of the utility model can be designed as a multi-stage cooling structure, for example, it can include two-stage cooling. It includes: a vertical flue 101 extending downward from the exhaust port of the full oxygen kiln 1 and horizontal flues 1-3 connected to the vertical flue 101, and the front end of the horizontal flue 103 also has a settling tank 102 for depositing flying material crystals in the flue gas; a heat exchanger 2 arranged on the main flue and located after the horizontal flue 103.

[0039] In one embodiment, the process flow of the flue gas treatment system is detailed as "full oxygen kiln → flue gas temperature adjustment → heat exchanger → adsorbent injection → ceramic tube reactor → reducing agent ammonia injection → SCR reactor → induced draft fan → chimney", which specifically includes the following steps:

[0040] The purified air from the induced draft fan diversion part is placed in the downward vertical flue as dilution air to perform primary cooling of the flue gas;

[0041] The flying material crystals in the flue gas are deposited in the settling tank;

[0042] The flue gas is subjected to secondary cooling through at least one heat exchanger to reach the process temperature required for conditioning;

[0043] Adsorbent is sprayed into flue gas through the powder spraying system to mix flue gas and adsorbent, thus achieving primary removal of fluorine and sulfur in the flue.

[0044] The ceramic reactor is used to remove fluorine and sulfur in the secondary stage and remove dust from the flue gas;

[0045] The reducing agent is sprayed into the flue between the ceramic tube reactor and the SCR denitration reactor;

[0046] Denitrification of flue gas through SCR denitrification reactor;

[0047] The partially purified flue gas is placed into the chimney through the induced draft fan.

[0048] In the embodiment of the utility model, according to the characteristics of the all-oxygen kiln, at the vertical flue at the outlet of the melting furnace, the flue gas temperature is above 1100°C, about 1200°C, to ensure that the flue gas temperature at the outlet B of the settling tank reaches 700°C. The flue gas temperature control device can adopt two-stage cooling, including: a vertical flue and a horizontal flue as the first stage of cooling by introducing purified air to dilute the flue gas, and a heat exchanger as the second stage of cooling. After the high-temperature flue gas of the kiln is discharged from the all-oxygen kiln 1, the original flue gas temperature is reduced from 1200°C to about 700°C through the purified dilution air in the vertical flue 101, and then the flue gas enters the heat exchanger 2. The flue gas temperature is controlled in the range of 370-400°C by heat exchange, and the temperature of the adsorbent injection point in the flue gas process section is controlled in the range of 330-360°C to ensure that the adsorbent maintains the best activity.

[0049] The utility model realizes efficient removal of flue gas pollutants such as sulfide, fluoride and dust through the ceramic tube reactor 4; after the flue gas is discharged from the ceramic tube reactor 4, it is sprayed with reducing agent ammonia water, and the flue gas-ammonia is effectively and evenly mixed through the static mixer, and after entering the SCR reactor 5, the nitrogen compound NOx is efficiently purified, thereby realizing efficient removal of multiple pollutants in the flue gas, and finally discharged to the chimney 7 through the induced draft fan 6.

[0050] In the above embodiment, the rear end of the induced draft fan 6 is divided into two flue gas discharge outlets, one of which is diverted directly into the chimney 7 for discharge; the other branch is diverted and led back to the vertical flue 101 and the horizontal flue 103 as dilution air or purification air to achieve the regulation of lowering the temperature of the original flue gas. A radiator 10 can also be added to the section of the purified air flue 107 to further reduce the temperature of the purified air, or the flue gas can be further cooled by a pre-installed heat exchanger 2, which not only effectively reduces the temperature of the original flue gas, but also greatly reduces the total amount of dilution air used, ensuring that the flue gas temperature meets the process requirements.

[0051] There is a purified air flue 107 between the pipeline at the rear end of the induced draft fan 6 and the vertical flue 101, and the induced draft fan 6 introduces part of the purified flue gas as purified air into the vertical flue 101 through the purified air flue 107. Figure 2As shown, the height of the vertical flue 101 is 5m, the bottom of the vertical flue 101 is a horizontal flue 103, the settling tank 102 is arranged in the horizontal flue 102, and the length of the settling tank 102 is 7.5m. The utility model creatively implants purified flue gas at the top A of the vertical flue 101 as dilution air or purification air, which not only mixes and dilutes the high-temperature flue gas at the exhaust port of the full oxygen kiln, and cools it with air, but also reduces the oxygen content in the flue gas.

[0052] In order to effectively control the flue gas temperature, purified air is inserted at the vertical flue 101A as dilution air to cool the flue gas. After calculation, the required dilution air is 4000Nm 3 / h or less. The dilution air of the flue gas treatment system adopts the purified air after the rear-end treatment of the induced draft fan 6, and its main purpose is to reduce the original flue gas temperature to meet the ideal operating temperature conditions of the rear-end equipment, and effectively control the increase of the oxygen content of the original flue gas to ensure the stable control of the concentration of flue gas pollutants.

[0053] In one embodiment, in order to effectively process the molten crystals of flying materials in the flue, the utility model sets a sedimentation tank 102 at the front end of the horizontal flue 103, and ensures that the flue gas temperature is reduced to between 650 and 750°C, preferably 700°C at the outlet B of the sedimentation tank 102, in order to ensure that all flying materials are crystallized and deposited in the sedimentation tank 102.

[0054] In one embodiment, the utility model selects the diverted purified air at the rear end of the induced draft fan 6 as the dilution air. Through on-site investigation and analysis of each flue, the flue gas temperature of the flue gas treatment system of the utility model at the rear end of the SCR reactor 5 is in the range of 300-320°C, and the flue gas after the rear end of the induced draft fan 6 is also around 280°C. In fact, the lower the dilution air temperature, the better the flue gas cooling effect in the front vertical flue 101; in order to obtain ideal low-temperature dilution air, the rear end of the induced draft fan 6 is generally not subjected to insulation treatment.

[0055] Preferably, a radiator 10 may be provided on the flue from the induced draft fan 6 to the vertical flue 101 to reduce the temperature of the purified air. For example, the temperature of the purified air may be reduced by implanting a WK-SRQ radiator.

[0056] Further preferably, the heat exchanger 2 is provided with two, namely the first heat exchanger 2A and the second heat exchanger 2B, which are connected in parallel and enter the flue, respectively, in a one-in-use and one-in-standby manner, and the purified air of the diverted part of the induced draft fan 6 is also introduced into at least one of the heat exchangers 2. In this embodiment, the flue gas temperature is reduced by introducing the front one-in-use and one-in-standby heat exchanger to divert the purified air in a bypass manner, which will be more conducive to the effective reduction of the dilution air temperature, which can not only reduce the dilution air usage, but also reduce the load of the flue gas treatment system, reduce energy consumption, etc.

[0057] In some embodiments, the heat exchanger 2 of the flue gas treatment system of the utility model adopts an air-to-air heat exchanger to cool the high-temperature flue gas of the all-oxygen kiln, ensuring that the rear-end ceramic tube reactor 4 is efficiently purified at the optimal temperature. The air-to-air heat exchanger system is mainly composed of a main heat exchange unit, a flue gas inlet and outlet, an air inlet and outlet, an air supply unit and other auxiliary parts. Among them, the purified air flue 107 introduces the purified air of the induced draft fan diversion part into the air inlet and outlet of the air-to-air heat exchanger through a bypass pipe 108. After the flue gas is cooled twice, the temperature is controlled at about 370-400°C.

[0058] In order to ensure that the flue gas temperature of the quenching and tempering device is within the range of 330-360℃, this system implants an air-to-air heat exchanger in the main flue as a secondary cooling device for the flue gas to prevent the pre-heated flue gas from being too hot and failing to reach the process temperature required for quenching and tempering. In order to avoid the problem of heat exchange tube plate hardening in the heat exchanger and ensure the normal operation of the system, the air-to-air heat exchanger is used in one standby mode, and a purified air bypass interface is set at the original flue gas inlet of the heat exchanger to prevent the flue gas temperature from being too high when entering the heat exchanger, and the temperature of the heat exchanger inlet and outlet is effectively controlled by bypassing the purified air.

[0059] In one embodiment, the purified air flue 107 includes a first branch flue 109 introduced into the upper end of the vertical flue 101 and a second branch flue 110 introduced into the front end of the horizontal flue, and the first branch flue and the second branch flue are both provided with a purification fan 11 and a regulating valve 12. The embodiment of the utility model makes the use of purified air more scientific and reasonable by classifying and optionally introducing the purified air into the main flue, which is also conducive to the smooth flow of smoke in the entire flue and the crystallization and deposition of flying materials.

[0060] In some embodiments, in order to remove water vapor in the flue gas and modulate desulfurization, the adsorbent injected by the powder spraying system 3 is lime powder with a mesh size of 500, a purity of more than 90%, and a moisture content of less than 0.5% for dry conditioning and desulfurization of the flue gas. The powder spraying system 3 also includes a lime feeding device, which is mainly composed of a lime silo, a lime silo top dust collector, a lime metering feeder, a silo heating system, fluidized compressed air, a vibrator, a backflush device, a discharger, a high and low level indicator, a metering cone, a weight sensor and other auxiliary parts.

[0061] The powder spraying system 3 can control the powder amount according to the changes in the fluoride and sulfur dioxide concentrations in the flue gas. A static mixer is provided at the rear end of the powder spraying to enable the flue gas and lime powder to be efficiently and evenly mixed, thereby achieving primary purification and removal of flue gas pollutants such as defluorination and desulfurization in the flue process. After that, the evenly mixed lime powder and flue gas enter the ceramic reactor again, so that the residual HF and SO2 in the flue gas are removed for the second time when passing through the lime filter cake powder layer attached to the outer surface of the ceramic filter element, and at the same time, the dust and other complex components in the flue gas are efficiently removed.

[0062] In some embodiments, a flue conditioning system is arranged in the flue 104 at the rear end of the heat exchanger between the powder spraying system 3 and the ceramic tube reactor 4 to evenly mix the flue gas with lime powder. The utility model pre-removes acidic substances such as HF, SO2 and viscous substances in the flue gas through an efficient flue conditioning system, in which an important design is the gas-solid mixing technology. The utility model adopts a static mixer design that conforms to the flow field homogenization theory in important sections after powder spraying, thereby effectively achieving the optimization of flue gas and lime powder uniform mixing and flue gas conditioning effect, ensuring efficient removal of acidic pollutants in the flue gas. In one embodiment, the flue conditioning system consists of a lime powder atomizing nozzle and a powder spraying fluidization unit, a flue material cone dispersion unit, a two-stage gas-solid static mixer, a guide plate unit and other auxiliary parts. Among them, the lime powder atomizing nozzle interface adopts DN100 or 150mm interface, the flue interface and the powder interface of the metering silo adopt DN100 or 150mm soft connection joint, the static mixer guide plate is made of stainless steel 304, and the powder spraying, static mixer and guide plate have reserved negative pressure gauge interface DN20, etc.

[0063] The dust removal device commonly used in the prior art generally adopts an electrostatic precipitator or a bag filter. The dust removal efficiency of the electrostatic precipitator is not high and the energy consumption is large. The bag filter cannot be used in scenes with high temperatures. Therefore, the dust removal device in the embodiment of the present application adopts a ceramic tube reactor 4. In some embodiments, the ceramic tube reactor 4 includes multiple chambers, each of which has multiple vertically arranged ceramic filter tubes. The ceramic filter tube is vacuum-formed with ceramic fiber and coated with a wear-resistant layer. Specifically, the ceramic tube reactor 4 can adopt a non-catalyst series ceramic filter tube, model φ150X3000mm. The ceramic filter tube has the characteristics of high strength, low breakage rate, porosity>80%, good dust collection effect, uniform tube wall thickness, and high acid component removal rate.

[0064] In order to ensure the high reliability of the flue gas treatment system and the effective back-blowing of the ceramic tube adsorbent layer, the utility model adopts the design concept of non-stop independent isolation back-blowing. The ceramic tube reactor 4 is composed of 4 chambers, each chamber is designed according to a 10×10 layout, and the installed number is 400 ceramic filter tubes. Acidic substances such as HF and SOx and dust are removed through the lime on the surface of the ceramic tube reactor 4.

[0065] In some embodiments, a dust collection and silo pump conveying system 8 is provided below the ceramic tube reactor 4. The dust collection and silo pump conveying system 8 centrally manages the ash discharge port of the ceramic tube reactor 4, and centrally collects dust from the four ash discharge ports and conveys them to the waste bin, etc., to ensure the cleanliness of the on-site environment and avoid personal injury to on-site operators; the dust collection control process can be based on the issuance of a high-limit alarm signal from the ash hopper of each group of reactors. The system starts the discharger and unloads ash according to the sequence of the alarm signals, and the time of each ash unloading cycle can be set in the reserved window on the interface; the present flue gas treatment system is designed with automatic dust collection, which mainly concentrates the ash slag in the four ash hoppers and conveys the dust to the ash storage bin by separate silo pump conveying methods.

[0066] In detail, the dust collection and silo pump conveying system 8 is mainly composed of an ash storage silo unit, a dust removal unit, a unloading unit, a powder collector unit (screw conveyor), a pneumatic conveying unit (including a gas-solid mixing chamber, pipelines, Roots blower and valve group, etc.), a backflush unit, instruments and meters, a control interface and auxiliary units.

[0067] In some embodiments, the flue gas treatment system of the utility model further includes a reducing agent injection device 9, which is mainly composed of an ammonia efficient atomization device, a spray gun distributor and a gas-gas homogenization device, a dust cleaning device and an automatic control component unit, wherein the efficient atomization and gas-gas homogenization devices are important parts for fully atomizing ammonia and mixing it evenly with the flue gas, which directly affects the subsequent denitration reaction effect. The reducing agent injection device 9 of the utility model injects ammonia gas or ammonia water into the reducing agent and sprays it into the flue 105, which can maximize the flue gas denitration effect.

[0068] In some embodiments, the SCR denitration reactor 5 uses a selective medium-temperature SCR catalytic reduction method for denitration treatment. The SCR denitration reactor 5 uses a compressed air soot blowing system. The soot blower is a pipe network soot blower, which is arranged above each catalyst layer. The soot in the kiln flue gas has a certain adhesion characteristic and is effectively blown to prevent blockage. The SCR denitration reactor 5 is composed of a honeycomb catalyst, a soot blowing unit, a reactor and auxiliary components.

[0069] The flue gas after efficient dust removal, desulfurization and defluorination enters the medium-temperature SCR denitrification reactor 5 to ensure that the flue gas denitrification temperature is not lower than 330°C. The reducing agent is sprayed into the flue 10 and the reducing agent injection device 9 is implanted. An appropriate amount of ammonia (or ammonia water) as a reducing agent is sprayed into the flue with the help of a uniquely designed high-efficiency atomization device. The atomized ammonia and the flue gas are fully and evenly mixed through a dedicated static mixer to improve the SCR denitrification reaction efficiency.

[0070] In some embodiments, a non-nitrate flue 106 is further provided on the main flue, the starting end of the non-nitrate flue 106 is connected to the front end of the SCR denitration reactor 5, and the terminal end is set at the rear end of the SCR denitration reactor 5. Under the premise that the nitrogen oxide content in the main flue is measured to be low and meets the emission standards, ammonia water or ammonia gas may not be injected into the flue gas, and the flue gas does not enter the SCR denitration reactor 5. The flue gas is directly introduced into the flue where the induced draft fan 6 is located through the non-nitrate flue 106 through valve control.

[0071] In some embodiments, to ensure stable operation of the flue gas treatment system, the induced draft fan 6 of the system is one in use and one in standby, including a first induced draft fan 6A and a second induced draft fan 6B respectively.

[0072] The clean flue gas after denitrification is discharged from the chimney 7 through the induced draft fan 6, and a part of the purified flue gas is used as dilution air to cool the front original flue gas. In order to ensure that the purified air has a good low-temperature effect, a WK-SRQ radiator can be added to cool the purified flue gas or introduced into the front-end heat exchanger 2 to cool the flue gas, thereby effectively controlling the efficient use of the purified lower temperature.

[0073] In some embodiments, the flue gas treatment system is further provided with a flue gas online monitoring system on the flue or equipment to monitor NO x concentration, SO2 concentration, and oxygen content.

[0074] In some embodiments, the flue design of the utility model minimizes the pressure drop of the system, and optimizes the layout, shape and internal components (such as guide plates and guide plates at bends). All flues within the scope of supply are equipped with sufficient number and size of manhole doors and ash cleaning holes at appropriate locations to facilitate the maintenance and inspection of the flue (including expansion joints and baffle doors) and the removal of accumulated ash. In addition, the manhole door is separated from the flue wall for insulation to facilitate opening.

[0075] In some embodiments, the flue gas treatment system also includes a control system, such as a DCS control system, which is responsible for processing the signals detected by various detection probes and directing the operation of the entire system according to established rules. The control system includes a monitoring part, which mainly displays online monitoring (CEMS) and instrument and instrument signal feedback, and is centrally controlled by a host computer. The control system is mainly composed of a UPS power cabinet, a DCS system control cabinet, a frequency conversion control cabinet, a field equipment control cabinet, field electrical instruments, etc. The topological schematic structure of the DCS control system is shown in the attached figure. Figure 3 shown.

[0076] The sensors of the monitoring part may include flow sensors, weight modules, HF probes, O2 probes, pollutant probes, temperature sensors, NH3 sensors and CEMS flue gas analyzers, etc. The sensors of the monitoring part transmit the collected signals directly or indirectly to the DCS system cabinet.

[0077] The host computer generally includes an engineer station OP50, an operator station OP51 and an operator station OP52 which are connected to the DCS system cabinet through switch A and switch B respectively, and their operation permissions can be set according to actual needs.

[0078] The executive instruments may generally include pneumatic control valves, regulator valves, dust collectors, etc. The DCS system cabinet may control the operation of the executive instruments automatically or through instructions issued by the host computer.

[0079] According to the fume treatment system for the all-oxygen kiln in the utility model, the beneficial effects that can be obtained include at least:

[0080] According to the fume treatment system for the all-oxygen kiln in the utility model, the beneficial effects that can be obtained include at least:

[0081] 1) The flue gas treatment system adopts multi-stage cooling, which is suitable for the high-temperature flue gas treatment of all-oxygen kilns. It also desulfurizes, denitrates, defluorinates and removes dust from the kiln flue gas to achieve stable emission of flue gas in compliance with standards.

[0082] 2) The flue gas treatment system diverts the purified air from the rear end of the induced draft fan into the vertical flue as dilution air, performs primary air cooling and mixed dilution on the high-temperature flue gas of the oxygen kiln, and can also reduce the oxygen content in the flue gas.

[0083] 3) The flue gas treatment system can reduce the temperature of the purified air by implanting a radiator in the purified air flue. It can also introduce a pre-installed one-in-one-out heat exchanger to divert the purified air to reduce the flue gas temperature. This will be more conducive to the effective reduction of the dilution air temperature, which can not only reduce the use of dilution air, but also reduce the load of the entire system and reduce energy consumption.

[0084] 4) The flue gas treatment system sets up a sedimentation tank in the horizontal flue to ensure that all flying materials are crystallized and deposited in the sedimentation tank.

[0085] 5) The flue gas treatment system adopts a ceramic reactor to remove the residual HF and SO2 in the flue gas for the second time when they pass through the lime filter cake powder layer attached to the outer surface of the ceramic filter element, and at the same time, the dust and other complex components in the flue gas are efficiently removed.

[0086] In the present invention, features described and / or illustrated for one embodiment may be used in the same manner or in a similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0087] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the embodiments of the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A flue gas treatment system for an oxygen kiln, characterized in that: The flue gas treatment system includes a flue gas temperature control device, a powder spraying system, a ceramic tube reactor, a reducing agent injection device, an SCR denitration reactor, an induced draft fan and a chimney which are arranged in sequence along the flue gas flow direction on the main flue; The flue gas treatment system further includes a purified air flue extending from the flue at the rear end of the induced draft fan to the front end of the main flue, and the induced draft fan introduces part of the purified flue gas as purified air into the main flue through the purified air flue; Wherein, the flue gas temperature regulating device comprises: A vertical flue extending downward from the exhaust port of the all-oxygen kiln and a horizontal flue connected to the vertical flue, wherein the front end of the horizontal flue is also provided with a settling tank for settling flying material crystals in the flue gas; A heat exchanger is arranged on the main flue and after the horizontal flue.

2. The flue gas treatment system for an oxygen kiln according to claim 1, characterized in that: A radiator is provided on the purified air flue from the induced draft fan to the vertical flue to reduce the temperature of the purified air.

3. The flue gas treatment system for an oxygen kiln according to claim 1 or 2, characterized in that: There are two heat exchangers, which are connected in parallel and enter the main flue respectively. The purified air of the diverted part of the induced draft fan is introduced into at least one of the heat exchangers through the bypass flue.

4. The flue gas treatment system for an oxygen kiln according to claim 1 or 2, characterized in that: The height of the vertical flue is 5m, the bottom end of the vertical flue is connected to the horizontal flue, the sedimentation tank is arranged at the front end of the horizontal flue, and the length of the sedimentation tank is 7.5m.

5. The flue gas treatment system for an oxygen kiln according to claim 1, characterized in that: The purified air flue comprises a first branch flow flue introduced into the upper end of the vertical flue and a second branch flow flue introduced into the front end of the horizontal flue, and both the first branch flow flue and the second branch flow flue are provided with a purified fan and a regulating valve.

6. The flue gas treatment system for an oxygen kiln according to claim 3, characterized in that: The heat exchanger is a gas-gas heat exchanger, comprising a main heat exchange unit, a smoke inlet and outlet, and an air inlet and outlet; The purified air flue introduces the purified air of the diverted part of the induced draft fan into the air inlet and outlet of the air-to-air heat exchanger through a bypass duct.

7. The flue gas treatment system for an oxygen kiln according to claim 6, characterized in that: A flue conditioning system is arranged in the main flue between the powder spraying system and the ceramic tube reactor to evenly mix the flue gas and the lime powder; the flue conditioning system includes a static mixer and a guide plate unit.

8. The flue gas treatment system for an oxygen kiln according to claim 1, characterized in that: The ceramic tube reactor comprises a plurality of chambers, each of which has a plurality of vertically arranged ceramic filter tubes, the ceramic filter tubes being vacuum-formed with ceramic fibers and coated with a wear-resistant layer; A dust collection and silo pump conveying system is provided below the ceramic tube reactor, including an ash storage silo unit and a powder collector unit.

9. The flue gas treatment system for an oxygen kiln according to claim 1, characterized in that: The induced draft fans are provided with two and are connected in parallel to enter the main flue.

10. The flue gas treatment system for an oxygen kiln according to claim 1, characterized in that: The flue gas treatment system is also equipped with a flue gas online monitoring system on the main flue or equipment to monitor NO x concentration, SO2 concentration, and oxygen content; the flue gas treatment system also includes a control system.

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