Carbon-rich lime kiln production system

Abstract

The utility model discloses a carbon-rich lime kiln production system which comprises a kiln body and a kiln cavity, the kiln cavity comprises a calcining chamber, a carbon cooling chamber, a water cooling chamber and an oxygen cooling chamber which are sequentially connected in series from top to bottom; a carbon dioxide injection mechanism is arranged at the lower part of the carbon cooling chamber; a water vapor injection mechanism is arranged at the lower part of the water cooling chamber; and an oxygen injection mechanism is arranged at the lower part of the oxygen cooling chamber. A single air or carbon dioxide cooling structure independently adopted by a traditional lime kiln cooling section is replaced with a multi-medium multi-stage cooling structure, CO2 enrichment is achieved, meanwhile, the lime cooling effect can be guaranteed and improved, and the quality of lime products is guaranteed; and the difficulty of capturing and recycling the carbon dioxide in the subsequent lime kiln flue gas can be greatly reduced. The device has the advantages of simple structure, easiness in operation, flexibility in adjustment, low investment cost and the like, and realizes effective compatibility of good carbon enrichment effect and good lime product quality.

Description

Technical Field

[0001] The utility model relates to lime production, in particular to a carbon-rich lime kiln production system, belonging to the technical field of lime production. Background Art

[0002] Lime is an important raw material for the iron and steel metallurgy and building materials industries, and its main component is CaO. The production of lime mainly comes from the calcination of limestone. Since the main component of limestone is CaCO3, it will decompose into CaO and CO2 at high temperature. The kiln used for calcination and production of lime is the lime kiln. In the lime production process, CO2 is not only a product of fuel combustion, but also a product of the decomposition of limestone itself. Therefore, compared with general industrial kilns, the CO2 concentration in the flue gas of the lime kiln is higher, reaching 20-30%. Taking a 600t / d gas-fired lime kiln as an example, its annual CO2 emissions are about 9 to 13 million standard cubic meters. In recent years, research on CO2 enrichment and capture in lime kilns has been increasingly popular.

[0003] Among the numerous lime kilns, the double-chamber lime kiln is the mainstream development direction of the current lime kiln due to its low energy consumption, long life and good product quality. Since the double-chamber lime kiln is composed of two symmetrical vertical kilns, when one of the chambers is calcining, the other chamber is the preheating chamber. The flue gas from the calcining chamber flows into the preheating chamber through the connecting channel to preheat the limestone in the preheating chamber, and the flue gas is finally discharged from the top of the preheating chamber. After the calcining chamber is completed, the double chamber is reversed through the valve, and the preheating chamber and calcining chamber in the previous production cycle are exchanged. Limestone is added from the top of the furnace and fills the furnace; fuel and air are added from the top of the furnace and calcined in the calcining chamber. The calcination temperature is 900-1050℃. At this temperature, the limestone decomposes and CO2 is precipitated. A large amount of flue gas generated by calcination enters the flue from top to bottom. The high-temperature lime generated by calcination continues to move downward under the action of gravity. The cooling air is introduced into the bottom of the furnace for cooling. The cooling air is the normal temperature air blown in by the blower, which flows countercurrently with the material and cools the material from bottom to top, and finally merges with the flue gas at the exhaust port and enters the flue together. After dust removal and other treatments, the flue gas is finally discharged into the atmosphere.

[0004] Since the traditional double-chamber lime kiln calcination uses air as a combustion-supporting agent, the N2 content in the flue gas is very high, and the CO2 in the flue gas will be greatly diluted by the cooling air, resulting in a low concentration of CO2 in the outlet flue gas, which is difficult to be effectively captured and recovered, and can only be discharged, resulting in a large carbon emission. In addition, although some scholars have proposed to recycle the dust-removed and dried lime oxygen-depleted flue gas back to the lime kiln, while introducing high-purity O2, controlling the ratio of O2 to circulating flue gas CO2 to 21:79, simulating the heat and mass transfer conditions of air, this production process reduces the intake of N2 in the combustion-supporting air, increases the concentration of CO2 in the calcination flue gas, and provides the possibility for the enrichment of CO2 in the lime kiln flue gas. However, the cooling problem of calcined lime has not been well solved. The temperature of the lime coming out of the calcining stage can reach up to 1000℃. If the traditional air cooling method is used, the introduction of a large amount of N2 in the air will greatly dilute the concentration of CO2 in the flue gas. If cooled circulating flue gas is used to cool the lime, the CO2 in the circulating flue gas will react with CaO under 600-750℃ to form CaCO3, which will cause the purity of the lime to decrease and affect the product quality. Utility Model Content

[0005] In view of the problem in the prior art that the existing lime kiln production system has a low exhaust CO2 concentration and is difficult to effectively capture and recycle, resulting in a large carbon emission, the utility model provides a carbon-rich lime kiln production system. By improving the structure of the existing lime kiln, the cooling process is optimized to a top-down multi-media step-by-step cooling structure, which can significantly increase the CO2 concentration in the calcination flue gas while cooling the lime to below the target temperature, thereby providing the possibility for low-cost capture of CO2, which is conducive to promoting low-carbon emissions.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present utility model are as follows:

[0007] A carbon-rich lime kiln production system comprises a kiln body and a kiln cavity; the kiln cavity comprises a calcining chamber, a carbon cooling chamber, a water cooling chamber and an oxygen cooling chamber which are sequentially connected in series from top to bottom; a material inlet, a fuel inlet, a smoke outlet and an combustion-supporting agent inlet are arranged on the kiln body corresponding to the calcining chamber; a carbon dioxide injection mechanism is arranged at the lower part of the carbon cooling chamber; a water vapor injection mechanism is arranged at the lower part of the water cooling chamber; and a material outlet and an oxygen injection mechanism are arranged at the lower part of the oxygen cooling chamber.

[0008] Preferably, the system also includes a flue gas treatment unit; the flue gas treatment unit includes a dust collector and a drying device; the flue gas outlet of the calcining chamber is connected in series with the dust collector and the drying device in sequence through a flue gas conveying pipeline; the exhaust port of the drying device is connected to the combustion-supporting agent inlet of the calcining chamber through a first flue gas circulation pipeline and / or the exhaust port of the drying device is connected to the gas inlet of the carbon dioxide injection mechanism through a second flue gas circulation pipeline.

[0009] Preferably, the system also includes a carbon dioxide distillation tower; the exhaust port of the drying device is connected to the gas inlet of the carbon dioxide distillation tower through an oxygen-rich and carbon-rich flue gas delivery pipeline; the carbon dioxide exhaust port of the carbon dioxide distillation tower is connected to the gas inlet of the carbon dioxide injection mechanism through a carbon dioxide delivery pipeline; preferably, the first flue gas circulation pipeline and the second flue gas circulation pipeline are both bypass pipelines of the oxygen-rich and carbon-rich flue gas delivery pipeline, and flow regulating control valves are independently provided on the first flue gas circulation pipeline, the second flue gas circulation pipeline and the oxygen-rich and carbon-rich flue gas delivery pipeline.

[0010] Preferably, the system also includes an oxygen-nitrogen air separation tower; the exhaust gas outlet of the carbon dioxide distillation tower is connected to the gas inlet of the oxygen-nitrogen air separation tower through a waste gas delivery pipeline; the oxygen outlet of the oxygen-nitrogen air separation tower is connected to the gas inlet of the oxygen injection mechanism through an oxygen delivery pipeline; the nitrogen outlet of the oxygen-nitrogen air separation tower is connected to the gas inlet of the nitrogen collection tank through a nitrogen delivery pipeline.

[0011] Preferably, the carbon dioxide injection mechanism comprises a carbon dioxide jet pipe row, a carbon dioxide nozzle and a carbon dioxide inlet pipe; the carbon dioxide jet pipe row is horizontally arranged at the lower part of the inner cavity of the carbon cooling chamber, and a plurality of carbon dioxide nozzles are evenly arranged on the carbon dioxide jet pipe row; the air inlet of the carbon dioxide jet pipe row is connected to an external air source through a carbon dioxide inlet pipe, and a flow regulating control valve is arranged on the carbon dioxide inlet pipe;

[0012] Preferably, a multi-layer carbon dioxide jet pipe row is arranged from top to bottom in the lower part of the inner cavity of the carbon cooling chamber, and a plurality of carbon dioxide nozzles are evenly arranged on each layer of the carbon dioxide jet pipe row; the air inlets of the multi-layer carbon dioxide jet pipe row are connected to an external air source through independent carbon dioxide air inlet pipes.

[0013] Preferably, the water vapor injection mechanism comprises a water vapor injection pipe row, a water vapor nozzle and a water vapor inlet pipe; the water vapor injection pipe row is horizontally arranged at the lower part of the inner cavity of the water cooling chamber, and a plurality of water vapor nozzles are evenly arranged on the water vapor injection pipe row; the steam inlet of the water vapor injection pipe row is connected to an external steam source through a water vapor inlet pipe, and a flow regulating control valve is arranged on the water vapor inlet pipe;

[0014] Preferably, a plurality of layers of water vapor spray pipe rows are arranged from top to bottom in the lower part of the inner cavity of the water cooling chamber, and a plurality of water vapor spray heads are evenly arranged on each layer of the water vapor spray pipe rows; the steam inlets of the plurality of layers of water vapor spray pipe rows are connected to an external steam source through independent water vapor inlet pipes.

[0015] Preferably, the oxygen injection mechanism comprises an oxygen jet pipe row, an oxygen nozzle and an oxygen inlet pipe; the oxygen jet pipe row is horizontally arranged at the lower part of the inner cavity of the oxygen cooling chamber, and a plurality of oxygen nozzles are evenly arranged on the oxygen jet pipe row; the air inlet of the oxygen jet pipe row is connected to an external air source through an oxygen inlet pipe, and a flow regulating control valve is arranged on the oxygen inlet pipe;

[0016] Preferably, multiple layers of oxygen jet pipe rows are arranged from top to bottom in the lower part of the inner cavity of the oxygen cooling chamber, and multiple oxygen nozzles are evenly arranged on each layer of oxygen jet pipe row; the air inlets of the multiple layers of oxygen jet pipe rows are connected to the external air source through independent oxygen inlet pipes.

[0017] It should be noted that, in the present invention, the oxygen injection mechanism may also be a plurality of oxygen inlet pipes evenly arranged around the bottom of the oxygen cooling chamber.

[0018] Preferably, the carbon dioxide nozzle, water vapor nozzle and oxygen nozzle have the same structure, and all include a vertical nozzle and a conical pipe head, a plurality of jet holes are evenly opened on the pipe wall of the vertical nozzle, and the conical pipe head is arranged at the top of the vertical nozzle; wherein: the bottom air inlet of the vertical nozzle of the carbon dioxide nozzle is connected to the carbon dioxide jet pipe row; the bottom air inlet of the vertical nozzle of the water vapor nozzle is connected to the water vapor jet pipe row; the bottom air inlet of the vertical nozzle of the oxygen nozzle is connected to the oxygen jet pipe row.

[0019] Preferably, a water-cooled wall is provided outside the oxygen cooling chamber, a cold water inlet is provided at the lower part of the water-cooled wall, and a steam outlet is provided at the upper part of the water-cooled wall; preferably, the steam outlet of the water-cooled wall is connected to the steam inlet of the water vapor injection mechanism through a steam conveying pipe; preferably, the water-cooled wall is a spiral water-cooled wall surrounding the outside of the oxygen cooling chamber from bottom to top.

[0020] Preferably, temperature detectors are independently provided in the calcining chamber, the carbon cooling chamber, the water cooling chamber and the oxygen cooling chamber; preferably, the temperature detectors are thermocouples.

[0021] In the present utility model, the height of the kiln body is 1 to 100 m, preferably 2 to 80 m, and more preferably 5 to 50 m. The thickness of the kiln wall is 0.5 to 80 cm, preferably 1 to 50 cm, and more preferably 2 to 30 cm. The kiln cavity is a chamber with a circular or square horizontal cross section, preferably a circular chamber, and the diameter of the circular chamber is 0.5 to 10 m, preferably 1 to 8 m, and more preferably 2 to 6 m.

[0022] In the prior art, the traditional double-chamber lime kiln calcination uses air as a combustion aid and cooling medium, which makes the N2 content in the flue gas very high, resulting in a large dilution of CO2 in the flue gas. Generally, the concentration of CO2 in the outlet flue gas is only 20% to 30%, and the cost of CO2 capture is still very high. Therefore, the utility model improves the structure of the lime kiln, mainly by improving its cooling section from the traditional single cooling structure of air or circulating flue gas to a multi-media step-by-step cooling structure, that is, according to the properties of each cooling medium, without affecting the quality of the lime product and the cooling effect, the lime kiln airflow is optimized, which not only greatly reduces the amount of nitrogen entering the calcination flue gas, but also increases the concentration of carbon dioxide in the calcination flue gas, greatly reduces the difficulty of capturing carbon dioxide in the flue gas, and is conducive to reducing carbon emissions.

[0023] In the utility model, the kiln cavity of the existing lime kiln is divided from top to bottom into a calcining chamber, a carbon cooling chamber, a water cooling chamber and an oxygen cooling chamber which are connected in series in sequence, and corresponding cooling medium injection mechanisms are arranged at the bottom of each cooling section for injecting different cooling gases. It should be noted that in actual engineering, the calcining chamber and the preheating chamber of the double-chamber lime kiln are designed with the same cooling mechanism. During the process of alternating cyclic calcination and preheating of the double chambers, the multi-gas graded cooling mechanism on the furnace acting as the calcining chamber is started, while the multi-gas graded cooling mechanism on the furnace acting as the preheating chamber is not started.

[0024] In the utility model, the preheated limestone enters the calcining chamber for high-temperature calcination and decomposition, and the heat required for calcination is obtained by introducing fuel and combustion-supporting agent into the calcining chamber for combustion. The combustion-supporting agent is a gas containing oxygen (in the utility model, it is preferred that the calcining flue gas is subjected to dust removal and drying to obtain oxygen-rich and carbon-rich flue gas). By using oxygen-rich and carbon-rich flue gas as a combustion-supporting agent, on the one hand, the oxygen from the oxygen cooling chamber can be circulated back to the calcining chamber for combustion-supporting, without the need to directly introduce air or oxygen from the calcining chamber, and the oxygen from the oxygen cooling chamber is preheated by heat exchange with the lime during the upward circulation process, and it is circulated into the calcining chamber together with the hot flue gas after calcination for combustion-supporting, which can greatly improve the utilization efficiency of heat compared to directly inputting cooling air or oxygen into the calcining chamber. In addition, the circulation of the calcining flue gas can also achieve the cyclic enrichment of carbon dioxide, which can greatly increase the concentration of carbon dioxide in the calcining flue gas, and provide the possibility for low-cost capture of CO2.

[0025] In the utility model, the carbon cooling chamber is located below the calcining chamber, and the lime is cooled once by spraying carbon dioxide into the carbon cooling chamber through a CO2 nozzle arranged at the bottom of the carbon cooling chamber. Generally, since the reverse reaction of CO2 and CaO to generate CaCO3 occurs at 600-750°C, the temperature of the lime in the carbon cooling chamber is detected (for example, a thermocouple is arranged in the carbon cooling chamber), and the injection amount of CO2 is controlled to cool the quicklime from about 1000°C to 750-800°C (preferably 750-770°C). It should be noted that the source of CO2 as a cooling medium can be high-purity CO2 purified by a CO2 distillation tower; it can also be oxygen-rich and carbon-rich flue gas obtained after dust removal and drying of the calcined flue gas, the main components of which are CO2 and O2. Under the target cooling temperature conditions controlled by the carbon cooling chamber, it will not react with CaO, and the lime can be cooled for the first time.

[0026] In the utility model, the water cooling chamber is located below the carbon cooling chamber, and the lime is secondary cooled by spraying high-temperature saturated water vapor into the water cooling chamber through a water vapor nozzle arranged at the bottom of the water cooling chamber. Since H2O and CaO will undergo a digestion reaction under certain conditions:

[0027] CaO+H2O=Ca(OH)2

[0028] The decomposition temperature of Ca(OH)2 is about 580°C, and CaO and H2O are regenerated. Therefore, in the utility model, the temperature of the lime in the water cooling chamber is detected in real time (for example, a thermocouple is arranged in the water cooling chamber), and the amount of water vapor introduced is controlled to cool the quicklime from the carbon cooling chamber to 585-630°C (preferably 590-620°C). The water vapor at the inlet of this section is saturated water vapor, and the temperature is 400-500°C (preferably 410-480°C). Through precise temperature control, the water vapor and CaO do not undergo a digestion reaction, and the secondary cooling of the lime is achieved.

[0029] In the utility model, the oxygen cooling chamber is the lowest cooling section, which is located at the bottom of the water cooling chamber. An O2 nozzle is arranged at the bottom of the oxygen cooling chamber to spray oxygen into the oxygen cooling chamber to cool the lime three times. Since O2 hardly reacts with CaO under any temperature conditions, it can be used to cool the lime at the bottom layer. Even if O2 flows upward to the water cooling chamber and the carbon cooling chamber, it will not affect the lime product. Furthermore, in order to improve the cooling effect and reduce the amount of O2 used, an indirect heat exchange water cooling wall (such as a spiral water cooling wall) can be arranged on the wall surface of the oxygen cooling chamber to cool the lime near the wall surface and improve the cooling effect. Liquid water enters from the bottom of the spiral water cooling wall, rises in the oxygen cooling chamber spirally and becomes saturated steam. The saturated steam comes out from the upper outlet of the spiral tube. This part of the water vapor can be circulated as the cooling medium of the water cooling chamber. The O2 in the oxygen cooling chamber is high-purity O2 from the air separation unit, which is cooled by direct contact with lime. After indirect cooling by the water-cooled wall and direct cooling by O2, the lime is cooled to 150-200°C (preferably 160-180°C).

[0030] In the utility model, in order to make the lime heated evenly inside and outside, the nozzles of each cooling medium are inserted into the cooling section and evenly distributed. The specific distribution method and the number of nozzles are calculated and determined according to the cooling heat load of the actual working condition. Since the lime and the cooling medium are countercurrently cooled, the lime flows from top to bottom under the action of gravity, and the cooling medium flows from bottom to top under the negative pressure formed by the tail induced draft fan. If the traditional upward direct spraying method is adopted, fine particles of lime will fall into the nozzle, causing pipeline blockage. Therefore, in the utility model, the carbon dioxide nozzle, the water vapor nozzle and the oxygen nozzle have the same structure, all of which include a vertical nozzle and a conical pipe head, and a plurality of jet holes are evenly opened on the pipe wall of the vertical nozzle, and the conical pipe head is arranged at the top of the vertical nozzle. The conical pipe head is a pointed head protruding upward, and the lime falling on the pointed head will slide down from the inclined surface of the pointed head to avoid deposition and reduce the impact of the lime on the nozzle. The vertical nozzle is surrounded by small jet holes, and the air flow is sprayed outward along the radial direction of the pipe from the jet holes on the surrounding areas, and continues to flow into the kiln under the action of pressure.

[0031] In the present invention, the cooling effect of the cooling medium on the lime can be adjusted by adjusting the flow rate of the cooling medium on the one hand, and can be adjusted by the injection position of the cooling medium on the other hand. Relatively speaking, the present invention is equipped with a flue gas circulation process for carbon enrichment, so the wind flow balance is crucial to the stability of the system. If the flow rate of the cooling medium is frequently changed, it is also necessary to frequently adjust the system induced draft fan frequency and the circulating flue gas circulation ratio to ensure that the pressure, gas flow, and atmosphere composition in the furnace do not fluctuate too much. The cooling effect can also be adjusted to a certain extent by adjusting the position without causing fluctuations in the airflow balance and pressure in the kiln, which makes the operation easier.

[0032] In the utility model, compared with the traditional lime kiln, the lime kiln of the utility model is provided with a multi-layer cooling medium injection nozzle structure in each cooling chamber, and the cooling medium can be controlled to be injected from different positions of the lime kiln through a valve, so as to adjust the cooling effect of the cooling medium on the lime. For example, in the carbon cooling chamber and the water cooling chamber, the respective jet pipe rows of CO2, water vapor and oxygen have three adjustable positions at the upper, middle and lower layers, respectively, and more layers of jet pipe rows can be provided under the conditions of the space distance of the lime kiln according to the actual needs, so that each cooling chamber has greater adjustment flexibility.

[0033] In the present invention, the quality requirements for lime products are generally CaO>98%, Ca(OH)2<0.5%, CaCO3<1.5, and the cooling requirements for lime are the cooling temperature T of the lime outlet. out Not higher than 200℃. Therefore, the cooling effect of lime by adjusting the cooling medium injection position is generally:

[0034] (1) When T out When the temperature is >200℃, it indicates that the cooling intensity is insufficient and the cooling effect needs to be enhanced. In this case, the injection position of CO2, water vapor and oxygen can be moved down one layer, that is, the valves of the upper and middle jet (steam) pipe rows can be closed, and the valves of the lower jet (steam) pipe row can be opened.

[0035] (2) When the CaCO3 content in lime is greater than 1.5%, it indicates that the cooling temperature of the carbon cooling chamber is too low, resulting in a reverse carbonation reaction between CO2 and CaO in this section, which affects the product quality. In this case, the CO2 injection position can be moved up one layer, that is, the valves of the middle and lower carbon dioxide injection pipe rows are closed, and the valve of the upper carbon dioxide injection pipe row is opened.

[0036] (3) When Ca(OH)2 in lime is greater than 0.5%, it indicates that the cooling temperature of the water-cooling chamber is too low, resulting in a digestion reaction between H2O and CaO in this section, which affects the product quality. In this case, the steam injection position can be moved up one layer, that is, the middle and lower steam injection pipe valves are closed, and the upper steam injection pipe valve is opened.

[0037] In the present utility model, after the O2 / H2O / CO2 sprayed into each cooling chamber (including the carbon cooling chamber, the water cooling chamber, and the oxygen cooling chamber) completes the cooling of lime, it converges with the calcination section flue gas from bottom to top in the lime kiln and finally discharges from the lime kiln flue. Among them, H2O will be removed in the drying unit to prevent H2O from freezing and blocking in the subsequent CO2 rectification tower, affecting CO2 removal. A part of CO2 is used for circulating flue gas and returns to the lime kiln again, and another part enters the CO2 rectification tower to produce high-purity CO2 products. A part of O2 returns to the lime kiln along with the circulating flue gas and serves as the combustion-supporting agent for fuel combustion in the lime kiln to provide the O2 required for combustion. Another part enters the CO2 rectification tower. Since the boiling point of CO2 is lower than that of N2 / O2, after CO2 is removed, the remaining N2 / O2 enters the air separation unit to produce high-purity N2 and O2. Compared with the existing flue gas circulation lime production process flow, the O2 required for calcination in the lime kiln of the present utility model is no longer added from the calcination section in the kiln, but from the cooling section and circulates back to the lime kiln along with the circulating flue gas.

[0038] In the present utility model, in the entire cooling and circulation system, the material and air flow balance is crucial for stable production. For a lime kiln with a determined production scale, the input limestone raw materials and fuel quantity are generally stable. If the air flow in the furnace is unstable, for example, too high oxygen supply will cause overheating and over-temperature in the furnace, affecting the lime activity; while insufficient oxygen supply will cause incomplete decomposition of the product and incomplete combustion of the fuel. Although CO2 basically does not react in the kiln, it also plays a very crucial role in the heat transfer of the furnace. Therefore, in the oxygen-rich and carbon-rich flue gas circulated into the furnace, the concentrations and masses of O2 and CO2 should be accurately controlled. Define the concentration ratio of O2 to CO2 fed into the lime kiln as R, and the preferred value range of R is: 21 / 79 < R < 32 / 68, preferably 25 / 75 < R < 30 / 70.

[0039] In the present utility model, if the flue gas generated in the calcination chamber discharges from the lime kiln and its total flow rate is recorded as Q, Nm 3 , which can be measured by a flow meter set on the main flue; the flow rate of the oxygen-rich and carbon-rich flue gas circulated back to the combustion area in the furnace is Q1, Nm 3 ; then the circulation ratio is K = Q1 / Q (1). Generally, the value of K is 0 to 1, preferably 0.4 to 0.7. The circulation ratio K is controlled by a variable-frequency induced draft fan set on the corresponding flue gas circulation channel.

[0040] In the present utility model, further, a flue gas composition analyzer can be set on the circulation pipeline of the oxygen-rich and carbon-rich flue gas. The measured volume contents of O2 and CO2 in the oxygen-rich and carbon-rich flue gas are respectively recorded as and The mass and calorific value of the fuel input into the lime kiln are respectively recorded as m r, kg and q r , MJ / kg; then the actual circulation rate K is:

[0041]

[0042] In formula (2), a is the conversion coefficient between fuel calorific value and oxygen, and its value is 0.03~0.07Nm 3 / MJ, preferably 0.04 to 0.06Nm 3 / MJ. Generally speaking, the higher the total calorific value released by the fuel, the higher the amount of oxygen required.

[0043] In the present invention, the O2 in the system is added from the bottom of the oxygen cooling chamber at the bottom of the lime kiln, first used to cool the lime, and then enter the flue gas to form oxygen-rich and carbon-rich flue gas, and then circulate back to the calcining chamber of the lime kiln for combustion in the kiln. Generally speaking, if the lime is to be cooled from about 600°C to below 200°C according to the predetermined target, the O2 required will greatly exceed the O2 required for combustion in the kiln. Therefore, the O2 / CO2 in the oxygen-rich and carbon-rich flue gas circulated to the calcining chamber is usually greater than 35 / 65. Therefore, the total amount of oxygen entering the calcining chamber in the kiln is generally controlled by the circulation ratio, and then high-purity CO2 is added to the oxygen-rich and carbon-rich flue gas to reduce the ratio of O2 to CO2 entering the kiln, so that the real-time R s The value is always within the set R value range. The supplementary CO2 generally comes from the high-purity CO2 separated by the distillation tower, and the supplementary amount is recorded as Q2, m 3 :Then we have:

[0044]

[0045] In formula (3), is the volume content of carbon dioxide in the oxygen-rich and carbon-rich flue gas before air replenishment, %.

[0046] Furthermore, when R s When <R, oxygen can be added to the oxygen-rich and carbon-rich flue gas. The added O2 generally comes from the high-purity O2 separated by the air separation unit. The amount of oxygen added is recorded as Q3, Nm 3 ; then:

[0047]

[0048] In formula (4), is the volume content of oxygen in the oxygen-rich and carbon-rich flue gas before air replenishment, %.

[0049] In the present utility model, as described above, the preferred value range of the set R value is 21 / 79 < R < 32 / 68 (preferably 25 / 75 < R < 30 / 70). Generally, for a coal-fired lime kiln using coal as fuel, the value of R is 27 / 73 < R < 30 / 70 (i.e., taking a higher value); for a gas-fired lime kiln using gas as fuel, the value of R is 25 / 75 < R < 27 / 73 (i.e., taking a lower value).

[0050] In the present utility model, for the flow rates of CO2 / H2O / O2 introduced into each cooling chamber, on the one hand, it is determined whether the flow rates are appropriate based on the component analysis of the product, and on the other hand, it is determined according to the thermocouples arranged on the kiln wall. Since the thermocouples on the kiln wall can only measure the lime temperature near the kiln wall and cannot reflect the lime temperature at the central position, the flow rate of the cooling medium is mainly adjusted according to the product quality. The overall control idea is that if the injection of CO2 into the carbon cooling chamber is excessive, the temperature of the lime in the carbon cooling chamber will drop beyond the predetermined range, and the temperature of the lime in the carbon cooling chamber will be lower than 750 °C, then CO2 and CaO may undergo a carbonation reaction in the carbon cooling chamber to form CaCO3, ultimately resulting in a high CaCO3 content in the product. If the injection of water vapor into the water cooling chamber is excessive, the temperature of the lime in the water cooling chamber will drop beyond the predetermined range, and the temperature of the lime in the water cooling chamber will be lower than 580 °C, then H2O and CaO may undergo a lime digestion reaction in the carbon cooling chamber to form Ca(OH)2, resulting in a high Ca(OH)2 content in the product. Therefore, by detecting the contents of impurities CaCO3 and Ca(OH)2 in the final product, it can be judged whether the injection of CO2 and H2O in the cooling section is excessive. Therefore, in order to avoid insufficient cooling caused by过少 injection of CO2 and H2O, the cooling medium should be injected as much as possible under the condition that the impurity content in the product meets the standard (for the specific adjustment and control idea, see Figure 2 and Figure 3 as shown).

[0051] In the present utility model, when adjusting the cooling effect of lime by adjusting the flow rate, specifically: detect the components of the product lime. If the CaCO3 content in the product lime is greater than 1.5%, it indicates that the injection of CO2 is excessive, then the injection amount of CO2 can be reduced in multiple times (the reduction amplitude for each time is 1 - 5% of the CO2 flow rate before this reduction), and after the working condition is stable, re-detect the components of the product lime; if the CaCO3 content in the product lime is less than 1%, it indicates that the carbonation in the kiln is not serious. In order to ensure the cooling effect, the injection amount of CO2 can be increased in multiple times (the increase amplitude for each time is 1 - 5% of the CO2 flow rate before this increase), and after the working condition is stable, re-detect the components of the product lime; if the CaCO3 content in the product lime is between 1% and 1.5%, it indicates that the injection amount of CO2 is just appropriate and no adjustment is made. The lime components are repeatedly detected within a certain period to maintain real-time monitoring of the product quality.

[0052] Similarly, the composition of the product lime is tested. If the Ca(OH)2 content in the product lime is greater than 1%, it indicates that too much H2O has been injected. The amount of water vapor injected can be reduced for several times (the amplitude of a single reduction is 1-5% of the amount of water vapor introduced before the reduction), and the composition of the product lime is retested when the operating conditions are stable. If the Ca(OH)2 content in the product lime is less than 0.5%, it indicates that the digestion reaction in the kiln is not serious. In order to ensure the cooling effect, the amount of water vapor injected can be increased for several times (the amplitude of a single increase is 1-5% of the amount of carbon dioxide introduced before the increase), and the composition of the product lime is retested when the operating conditions are stable. If the Ca(OH)2 content in the product lime is between 0.5% and 5%, it indicates that the amount of water vapor injected is just right, and no adjustment is made. The lime composition is repeatedly tested within a certain period to maintain real-time monitoring of product quality.

[0053] It should be noted that although both adjusting the flow rate and adjusting the injection position can adjust the cooling effect of lime, adjusting the flow rate has a greater impact on the cooling effect and is suitable for the cold start of the lime kiln to normal production conditions; the flow rate adjustment method is used to find the flow condition that is most suitable for normal lime production. This method has a greater impact on the system airflow balance and requires the coordination of the pressure and flow regulation of the entire system to ensure stable production. The injection position adjustment method has a relatively small adjustment sensitivity, but has a smaller impact on the system airflow and pressure balance, and has a smaller impact on the overall production. It is easy to operate, so it is suitable for normal production. When the lime production and temperature fluctuate due to fluctuations in raw materials and fuel, adaptive adjustments can be made.

[0054] In the present invention, the content limit of CaCO3 in the product lime analysis is higher than that of Ca(OH)2 because CaCO3 is the main component of limestone, and there may be some undecomposed raw materials in the product, so the content of CaCO3 will be slightly higher than Ca(OH)2. The overall requirement for the quality of the product lime is that the CaO content in the final product lime is not less than 98%, preferably not less than 99%.

[0055] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0056] 1: The utility model modifies the single cooling structure of the traditional lime kiln cooling section that uses air or carbon dioxide alone into a multi-media multi-stage cooling structure. While achieving CO2 enrichment, it can also ensure and improve the cooling effect on lime and ensure the quality of lime products; it can greatly reduce the difficulty of capturing and recovering carbon dioxide in the subsequent lime kiln flue gas.

[0057] 2: The utility model arranges a spiral water-cooled wall outside the water-cooled chamber to cool the lime near the wall while utilizing the waste heat to heat water vapor, thereby reducing the production cost of steam; at the same time, the setting of the oxygen cooling chamber changes the traditional method of adding oxygen from the kiln top, so that the O2 in the circulating flue gas is greatly increased, and there is no need to spray additional oxygen in the kiln, which increases the use of oxygen and also improves the heat utilization efficiency.

[0058] 3: The utility model also has the advantages of simple structure, easy operation, flexible adjustment, low investment cost, etc., and achieves effective compatibility of good carbon enrichment effect and good lime product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the overall structure of the carbon-rich lime kiln production system of the utility model.

[0060] Figure 2 The utility model is a schematic diagram of the cross-sectional plan structure of the lime kiln cavity.

[0061] Figure 3 It is a schematic diagram of the structure of each cooling medium nozzle of the utility model.

[0062] Figure 4 This is a schematic diagram of the distribution of cooling medium nozzles in the lime kiln cross section of the utility model.

[0063] Figure numerals: 1: calcining chamber; 101: material inlet; 102: fuel inlet; 103: flue gas outlet; 104: combustion aid inlet; 2: carbon cooling chamber; 3: water cooling chamber; 4: oxygen cooling chamber; 5: carbon dioxide injection mechanism; 501: carbon dioxide jet pipe row; 502: carbon dioxide nozzle; 503: carbon dioxide inlet pipe; 6: water vapor injection mechanism; 601: water vapor jet pipe row; 602: water vapor nozzle; 603: water vapor inlet pipe; 7: oxygen injection mechanism; 701: oxygen jet pipe row; 702: oxygen nozzle ;703: oxygen inlet pipe;8: flue gas treatment unit;801: dust collector;802: drying device;803: first flue gas circulation pipeline;804: second flue gas circulation pipeline;805: oxygen-rich and carbon-rich flue gas conveying pipeline;9: carbon dioxide distillation tower;901: carbon dioxide conveying pipeline;902: waste gas conveying pipeline;10: oxygen-nitrogen air separation tower;1001: oxygen conveying pipeline;1002: nitrogen conveying pipeline;1003: nitrogen collecting tank;11: water-cooled wall;1101: steam conveying pipeline;12: temperature detector. DETAILED DESCRIPTION

[0064] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.

[0065] A carbon-rich lime kiln production system, the system comprises a kiln body and a kiln cavity; the kiln cavity comprises a calcining chamber 1, a carbon cooling chamber 2, a water cooling chamber 3 and an oxygen cooling chamber 4 which are sequentially connected in series from top to bottom; a material inlet 101, a fuel inlet 102, a smoke outlet 103 and an oxidant inlet 104 are provided on the kiln body corresponding to the calcining chamber 1; a carbon dioxide injection mechanism 5 is provided at the lower part of the carbon cooling chamber 2; a water vapor injection mechanism 6 is provided at the lower part of the water cooling chamber 3; a material outlet 401 and an oxygen injection mechanism 7 are provided at the lower part of the oxygen cooling chamber 4.

[0066] Preferably, the system also includes a flue gas treatment unit 8; the flue gas treatment unit 8 includes a dust collector 801 and a drying device 802; the flue gas outlet 103 of the calcining chamber 1 is connected in series with the dust collector 801 and the drying device 802 in sequence through a flue gas conveying pipeline; the exhaust port of the drying device 802 is connected to the combustion-supporting agent inlet 104 of the calcining chamber 1 through a first flue gas circulation pipeline 803 and / or the exhaust port of the drying device 802 is connected to the gas inlet of the carbon dioxide injection mechanism 5 through a second flue gas circulation pipeline 804.

[0067] Preferably, the system also includes a carbon dioxide distillation tower 9; the exhaust port of the drying device 802 is connected to the gas inlet of the carbon dioxide distillation tower 9 through an oxygen-rich and carbon-rich flue gas conveying pipeline 805; the carbon dioxide exhaust port of the carbon dioxide distillation tower 9 is connected to the gas inlet of the carbon dioxide injection mechanism 5 through a carbon dioxide conveying pipeline 901; preferably, the first flue gas circulation pipeline 803 and the second flue gas circulation pipeline 804 are both bypass pipelines of the oxygen-rich and carbon-rich flue gas conveying pipeline 805, and flow regulating control valves are independently provided on the first flue gas circulation pipeline 803, the second flue gas circulation pipeline 804 and the oxygen-rich and carbon-rich flue gas conveying pipeline 805.

[0068] Preferably, the system also includes an oxygen-nitrogen air separation tower 10; the waste gas exhaust port of the carbon dioxide distillation tower 9 is connected to the gas inlet of the oxygen-nitrogen air separation tower 10 through a waste gas delivery pipe 902; the oxygen outlet of the oxygen-nitrogen air separation tower 10 is connected to the gas inlet of the oxygen injection mechanism 7 through an oxygen delivery pipe 1001; the nitrogen outlet of the oxygen-nitrogen air separation tower 10 is connected to the gas inlet of the nitrogen collection tank 1003 through a nitrogen delivery pipe 1002.

[0069] Preferably, the carbon dioxide injection mechanism 5 comprises a carbon dioxide jet pipe row 501, a carbon dioxide nozzle 502 and a carbon dioxide inlet pipe 503; the carbon dioxide jet pipe row 501 is horizontally arranged at the lower part of the inner cavity of the carbon cooling chamber 2, and a plurality of carbon dioxide nozzles 502 are evenly arranged on the carbon dioxide jet pipe row 501; the air inlet of the carbon dioxide jet pipe row 501 is connected to an external air source through the carbon dioxide inlet pipe 503, and a flow regulating control valve is arranged on the carbon dioxide inlet pipe 503;

[0070] Preferably, a multi-layer carbon dioxide jet pipe row 501 is arranged from top to bottom in the lower part of the inner cavity of the carbon cold chamber 2, and a plurality of carbon dioxide nozzles 502 are evenly arranged on each layer of the carbon dioxide jet pipe row 501; the air inlets of the multi-layer carbon dioxide jet pipe row 501 are connected to an external air source through independent carbon dioxide inlet pipes 503.

[0071] Preferably, the water vapor injection mechanism 6 comprises a water vapor injection pipe row 601, a water vapor nozzle 602 and a water vapor inlet pipe 603; the water vapor injection pipe row 601 is horizontally arranged at the lower part of the inner cavity of the water cooling chamber 3, and a plurality of water vapor nozzles 602 are evenly arranged on the water vapor injection pipe row 601; the steam inlet of the water vapor injection pipe row 601 is connected to an external steam source through a water vapor inlet pipe 603, and a flow regulating control valve is arranged on the water vapor inlet pipe 603;

[0072] Preferably, a multi-layer water vapor spray pipe row 601 is arranged from top to bottom in the lower part of the inner cavity of the water cooling chamber 3, and a plurality of water vapor spray heads 602 are evenly arranged on each layer of the water vapor spray pipe row 601; the steam inlets of the multi-layer water vapor spray pipe row 601 are connected to an external steam source through independent water vapor inlet pipes 603 respectively.

[0073] Preferably, the oxygen injection mechanism 7 comprises an oxygen injection pipe row 701, an oxygen nozzle 702 and an oxygen inlet pipe 703; the oxygen injection pipe row 701 is horizontally arranged at the lower part of the inner cavity of the oxygen cooling chamber 4, and a plurality of oxygen nozzles 702 are evenly arranged on the oxygen injection pipe row 701; the air inlet of the oxygen injection pipe row 701 is connected to an external air source through the oxygen inlet pipe 703, and a flow regulating control valve is arranged on the oxygen inlet pipe 703;

[0074] Preferably, a multi-layer oxygen jet pipe row 701 is arranged from top to bottom in the lower part of the inner cavity of the oxygen cooling chamber 4, and a plurality of oxygen nozzles 702 are evenly arranged on each layer of the oxygen jet pipe row 701; the air inlets of the multi-layer oxygen jet pipe row 701 are connected to an external air source through independent oxygen inlet pipes 703.

[0075] Preferably, the carbon dioxide nozzle 502, the water vapor nozzle 602 and the oxygen nozzle 702 have the same structure, and all include a vertical nozzle and a conical pipe head, a plurality of jet holes are evenly opened on the pipe wall of the vertical nozzle, and the conical pipe head is arranged at the top of the vertical nozzle; wherein: the bottom air inlet of the vertical nozzle of the carbon dioxide nozzle 502 is connected to the carbon dioxide jet pipe row 501; the bottom air inlet of the vertical nozzle of the water vapor nozzle 602 is connected to the water vapor jet pipe row 601; the bottom air inlet of the vertical nozzle of the oxygen nozzle 702 is connected to the oxygen jet pipe row 701.

[0076] Preferably, a water-cooled wall 11 is further provided outside the oxygen cooling chamber 4, a cold water inlet is provided at the lower portion of the water-cooled wall 11, and a steam outlet is provided at the upper portion of the water-cooled wall 11; preferably, the steam outlet of the water-cooled wall 11 is connected to the steam inlet of the water vapor injection mechanism 6 through a steam delivery pipe 1101; preferably, the water-cooled wall 11 is a spiral water-cooled wall surrounding the outside of the oxygen cooling chamber 4 from bottom to top.

[0077] Preferably, a temperature detector 12 is independently provided in the calcining chamber 1, the carbon cooling chamber 2, the water cooling chamber 3 and the oxygen cooling chamber 4; preferably, the temperature detector 12 is a thermocouple.

[0078] Example 1

[0079] like Figure 1-4 As shown, a carbon-rich lime kiln production system comprises a kiln body and a kiln cavity; the kiln cavity comprises a calcining chamber 1, a carbon cooling chamber 2, a water cooling chamber 3 and an oxygen cooling chamber 4 which are sequentially connected in series from top to bottom; a material inlet 101, a fuel inlet 102, a flue gas outlet 103 and an oxidation-supporting agent inlet 104 are provided on the kiln body corresponding to the calcining chamber 1; a carbon dioxide injection mechanism 5 is provided at the lower part of the carbon cooling chamber 2; a water vapor injection mechanism 6 is provided at the lower part of the water cooling chamber 3; a material outlet 401 and an oxygen injection mechanism 7 are provided at the lower part of the oxygen cooling chamber 4.

[0080] Example 2

[0081] Embodiment 1 is repeated, except that the system further includes a flue gas treatment unit 8; the flue gas treatment unit 8 includes a dust collector 801 and a drying device 802; the flue gas outlet 103 of the calcining chamber 1 is connected in series with the dust collector 801 and the drying device 802 in sequence through a flue gas conveying pipeline; the exhaust port of the drying device 802 is connected to the combustion-supporting agent inlet 104 of the calcining chamber 1 through a first flue gas circulation pipeline 803 and / or the exhaust port of the drying device 802 is connected to the gas inlet of the carbon dioxide injection mechanism 5 through a second flue gas circulation pipeline 804.

[0082] Example 3

[0083] Embodiment 2 is repeated, except that the system further includes a carbon dioxide distillation tower 9; the exhaust port of the drying device 802 is connected to the gas inlet of the carbon dioxide distillation tower 9 through an oxygen-rich and carbon-rich flue gas conveying pipeline 805; the carbon dioxide exhaust port of the carbon dioxide distillation tower 9 is connected to the gas inlet of the carbon dioxide injection mechanism 5 through a carbon dioxide conveying pipeline 901; the first flue gas circulation pipeline 803 and the second flue gas circulation pipeline 804 are both bypass pipelines of the oxygen-rich and carbon-rich flue gas conveying pipeline 805, and flow regulating control valves are independently provided on the first flue gas circulation pipeline 803, the second flue gas circulation pipeline 804 and the oxygen-rich and carbon-rich flue gas conveying pipeline 805.

[0084] Example 4

[0085] Embodiment 3 is repeated, except that the system further includes an oxygen-nitrogen air separation tower 10; the exhaust gas outlet of the carbon dioxide distillation tower 9 is connected to the gas inlet of the oxygen-nitrogen air separation tower 10 through the exhaust gas conveying pipeline 902; the oxygen outlet of the oxygen-nitrogen air separation tower 10 is connected to the gas inlet of the oxygen injection mechanism 7 through the oxygen conveying pipeline 1001; the nitrogen outlet of the oxygen-nitrogen air separation tower 10 is connected to the gas inlet of the nitrogen collection tank 1003 through the nitrogen conveying pipeline 1002.

[0086] Example 5

[0087] Embodiment 4 is repeated, except that the carbon dioxide injection mechanism 5 includes a carbon dioxide jet pipe row 501, a carbon dioxide nozzle 502 and a carbon dioxide inlet pipe 503; the carbon dioxide jet pipe row 501 is horizontally arranged at the lower part of the inner cavity of the carbon cooling chamber 2, and a plurality of carbon dioxide nozzles 502 are evenly arranged on the carbon dioxide jet pipe row 501; the air inlet of the carbon dioxide jet pipe row 501 is connected to an external air source through the carbon dioxide inlet pipe 503, and a flow regulating control valve is arranged on the carbon dioxide inlet pipe 503;

[0088] Example 6

[0089] Embodiment 5 is repeated, except that a multi-layer carbon dioxide jet pipe row 501 is arranged from top to bottom in the lower part of the inner cavity of the carbon cold chamber 2, and a plurality of carbon dioxide nozzles 502 are evenly arranged on each layer of the carbon dioxide jet pipe row 501; the air inlets of the multi-layer carbon dioxide jet pipe row 501 are connected to the external air source through independent carbon dioxide air inlet pipes 503.

[0090] Example 7

[0091] Embodiment 6 is repeated, except that the water vapor injection mechanism 6 includes a water vapor injection pipe row 601, a water vapor nozzle 602 and a water vapor inlet pipe 603; the water vapor injection pipe row 601 is horizontally arranged at the lower part of the inner cavity of the water cooling chamber 3, and a plurality of water vapor nozzles 602 are evenly arranged on the water vapor injection pipe row 601; the steam inlet of the water vapor injection pipe row 601 is connected to the external steam source through the water vapor inlet pipe 603, and a flow regulating control valve is arranged on the water vapor inlet pipe 603;

[0092] Example 8

[0093] Embodiment 7 is repeated, except that a plurality of layers of water vapor spray pipe rows 601 are arranged from top to bottom in the lower part of the inner cavity of the water cooling chamber 3, and a plurality of water vapor spray heads 602 are evenly arranged on each layer of the water vapor spray pipe rows 601; the steam inlets of the plurality of layers of the water vapor spray pipe rows 601 are connected to an external steam source through independent water vapor inlet pipes 603.

[0094] Example 9

[0095] Embodiment 8 is repeated, except that the oxygen injection mechanism 7 includes an oxygen injection pipe row 701, an oxygen nozzle 702 and an oxygen inlet pipe 703; the oxygen injection pipe row 701 is horizontally arranged at the lower part of the inner cavity of the oxygen cooling chamber 4, and a plurality of oxygen nozzles 702 are evenly arranged on the oxygen injection pipe row 701; the air inlet of the oxygen injection pipe row 701 is connected to the external air source through the oxygen inlet pipe 703, and a flow regulating control valve is arranged on the oxygen inlet pipe 703;

[0096] Example 10

[0097] Embodiment 9 is repeated, except that a multi-layer oxygen jet pipe row 701 is arranged from top to bottom in the lower part of the inner cavity of the oxygen cooling chamber 4, and a plurality of oxygen nozzles 702 are evenly arranged on each layer of the oxygen jet pipe row 701; the air inlets of the multi-layer oxygen jet pipe row 701 are connected to the external air source through independent oxygen inlet pipes 703.

[0098] Embodiment 11

[0099] Embodiment 10 is repeated, except that the carbon dioxide nozzle 502, the water vapor nozzle 602 and the oxygen nozzle 702 have the same structure, all of which include a vertical nozzle and a conical pipe head, a plurality of jet holes are evenly opened on the pipe wall of the vertical nozzle, and the conical pipe head is arranged at the top of the vertical nozzle; wherein: the bottom air inlet of the vertical nozzle of the carbon dioxide nozzle 502 is connected to the carbon dioxide jet pipe row 501; the bottom air inlet of the vertical nozzle of the water vapor nozzle 602 is connected to the water vapor jet pipe row 601; the bottom air inlet of the vertical nozzle of the oxygen nozzle 702 is connected to the oxygen jet pipe row 701.

[0100] Example 12

[0101] Embodiment 11 is repeated, except that a water-cooled wall 11 is further provided outside the oxygen cooling chamber 4, a cold water inlet is provided at the lower portion of the water-cooled wall 11, and a steam outlet is provided at the upper portion of the water-cooled wall 11; the steam outlet of the water-cooled wall 11 is connected to the steam inlet of the water steam injection mechanism 6 through a steam delivery pipe 1101; the water-cooled wall 11 is a spiral water-cooled wall surrounding the outside of the oxygen cooling chamber 4 from bottom to top.

[0102] Embodiment 13

[0103] Embodiment 12 is repeated, except that temperature detectors 12 are independently provided in the calcining chamber 1, the carbon cooling chamber 2, the water cooling chamber 3 and the oxygen cooling chamber 4; the temperature detectors 12 are thermocouples.

[0104] Test experiment: The same limestone was calcined to produce quicklime using the conventional lime kiln (air cooling), the existing flue gas circulation (referring to circulating the dried oxygen-poor flue gas to the calcination area for carbon dioxide enrichment) lime kiln (air cooling, the existing flue gas circulation lime kiln (carbon dioxide cooling), and the carbon-rich lime kiln production system of the utility model (including abnormal conditions of cooling medium fluctuations). The effects of various parameters are compared as shown in the following table:

[0105]

[0106]

[0107] It can be clearly seen that compared with several other working conditions, the carbon-rich lime kiln of the utility model (normal CO2, normal H2O) simultaneously achieves the improvement of CO2 and the guarantee of lime product quality. At the same time, the O2 in the circulating flue gas is greatly increased, and no additional oxygen is needed in the kiln, which greatly reduces the carbon capture cost of the lime kiln flue gas.

Claims

1. A carbon-rich lime kiln production system, characterized in that: The system comprises a kiln body and a kiln chamber; the kiln chamber comprises a calcining chamber (1), a carbon cooling chamber (2), a water cooling chamber (3) and an oxygen cooling chamber (4) which are sequentially connected in series from top to bottom; a material inlet (101), a fuel inlet (102), a smoke outlet (103) and an oxidant inlet (104) are provided on the kiln body corresponding to the calcining chamber (1); a carbon dioxide injection mechanism (5) is provided at the bottom of the carbon cooling chamber (2); a water vapor injection mechanism (6) is provided at the bottom of the water cooling chamber (3); and a material outlet (401) and an oxygen injection mechanism (7) are provided at the bottom of the oxygen cooling chamber (4).

2. The system according to claim 1, characterized in that: The system further comprises a flue gas treatment unit (8); the flue gas treatment unit (8) comprises a dust collector (801) and a drying device (802); the flue gas outlet (103) of the calcining chamber (1) is connected in series with the dust collector (801) and the drying device (802) in sequence through a flue gas conveying pipeline; the exhaust port of the drying device (802) is connected to the combustion-supporting agent inlet (104) of the calcining chamber (1) through a first flue gas circulation pipeline (803) and / or the exhaust port of the drying device (802) is connected to the gas inlet of the carbon dioxide injection mechanism (5) through a second flue gas circulation pipeline (804).

3. The system according to claim 2, characterized in that: The system also includes a carbon dioxide distillation tower (9); the exhaust port of the drying device (802) is connected to the gas inlet of the carbon dioxide distillation tower (9) through an oxygen-rich and carbon-rich flue gas delivery pipeline (805); the carbon dioxide exhaust port of the carbon dioxide distillation tower (9) is connected to the gas inlet of the carbon dioxide injection mechanism (5) through a carbon dioxide delivery pipeline (901).

4. The system according to claim 3, characterized in that: The first flue gas circulation duct (803) and the second flue gas circulation duct (804) are both bypass ducts of the oxygen-rich and carbon-rich flue gas delivery duct (805), and flow regulating control valves are independently arranged on the first flue gas circulation duct (803), the second flue gas circulation duct (804) and the oxygen-rich and carbon-rich flue gas delivery duct (805).

5. The system according to claim 3, characterized in that: The system also includes an oxygen-nitrogen air separation tower (10); the waste gas exhaust port of the carbon dioxide rectification tower (9) is connected to the gas inlet of the oxygen-nitrogen air separation tower (10) through a waste gas delivery pipeline (902); the oxygen outlet of the oxygen-nitrogen air separation tower (10) is connected to the gas inlet of the oxygen injection mechanism (7) through an oxygen delivery pipeline (1001); and the nitrogen outlet of the oxygen-nitrogen air separation tower (10) is connected to the gas inlet of a nitrogen collection tank (1003) through a nitrogen delivery pipeline (1002).

6. The system according to any one of claims 1 to 5, characterized in that: The carbon dioxide injection mechanism (5) comprises a carbon dioxide jet pipe row (501), a carbon dioxide nozzle (502) and a carbon dioxide air inlet pipe (503); the carbon dioxide jet pipe row (501) is horizontally arranged at the lower part of the inner cavity of the carbon cooling chamber (2), and a plurality of carbon dioxide nozzles (502) are evenly arranged on the carbon dioxide jet pipe row (501); the air inlet of the carbon dioxide jet pipe row (501) is connected to an external air source through the carbon dioxide air inlet pipe (503), and a flow regulating control valve is arranged on the carbon dioxide air inlet pipe (503).

7. The system according to claim 6, characterized in that: A plurality of carbon dioxide jet pipe rows (501) are arranged from top to bottom in the lower part of the inner cavity of the carbon cooling chamber (2), and a plurality of carbon dioxide nozzles (502) are evenly arranged on each layer of the carbon dioxide jet pipe row (501); the air inlets of the plurality of carbon dioxide jet pipe rows (501) are connected to an external air source through independent carbon dioxide air inlet pipes (503).

8. The system according to any one of claims 1 to 5 and 7, characterized in that: The water vapor injection mechanism (6) comprises a water vapor injection pipe row (601), a water vapor injection head (602) and a water vapor inlet pipe (603); the water vapor injection pipe row (601) is horizontally arranged at the lower part of the inner cavity of the water cooling chamber (3), and a plurality of water vapor injection heads (602) are evenly arranged on the water vapor injection pipe row (601); the steam inlet of the water vapor injection pipe row (601) is connected to an external steam source through the water vapor inlet pipe (603), and a flow regulating control valve is arranged on the water vapor inlet pipe (603).

9. The system according to claim 6, characterized in that: The water vapor injection mechanism (6) comprises a water vapor injection pipe row (601), a water vapor injection head (602) and a water vapor inlet pipe (603); the water vapor injection pipe row (601) is horizontally arranged at the lower part of the inner cavity of the water cooling chamber (3), and a plurality of water vapor injection heads (602) are evenly arranged on the water vapor injection pipe row (601); the steam inlet of the water vapor injection pipe row (601) is connected to an external steam source through the water vapor inlet pipe (603), and a flow regulating control valve is arranged on the water vapor inlet pipe (603).

10. The system according to claim 8, characterized in that: A plurality of water vapor spray pipe rows (601) are arranged from top to bottom in the lower part of the inner cavity of the water cooling chamber (3), and a plurality of water vapor spray heads (602) are evenly arranged on each layer of the water vapor spray pipe row (601); the steam inlets of the plurality of water vapor spray pipe rows (601) are connected to an external steam source through independent water vapor inlet pipes (603).

11. The system according to claim 9, characterized in that: A plurality of water vapor spray pipe rows (601) are arranged from top to bottom in the lower part of the inner cavity of the water cooling chamber (3), and a plurality of water vapor spray heads (602) are evenly arranged on each layer of the water vapor spray pipe row (601); the steam inlets of the plurality of water vapor spray pipe rows (601) are connected to an external steam source through independent water vapor inlet pipes (603).

12. The system according to any one of claims 1 to 5 and 7, characterized in that: The oxygen injection mechanism (7) comprises an oxygen injection pipe row (701), an oxygen nozzle (702) and an oxygen inlet pipe (703); the oxygen injection pipe row (701) is horizontally arranged at the lower part of the inner cavity of the oxygen cooling chamber (4), and a plurality of oxygen nozzles (702) are evenly arranged on the oxygen injection pipe row (701); the air inlet of the oxygen injection pipe row (701) is connected to an external air source through the oxygen inlet pipe (703), and a flow regulating control valve is arranged on the oxygen inlet pipe (703).

13. The system according to claim 9 or 11, characterized in that: The oxygen injection mechanism (7) comprises an oxygen injection pipe row (701), an oxygen nozzle (702) and an oxygen inlet pipe (703); the oxygen injection pipe row (701) is horizontally arranged at the lower part of the inner cavity of the oxygen cooling chamber (4), and a plurality of oxygen nozzles (702) are evenly arranged on the oxygen injection pipe row (701); the air inlet of the oxygen injection pipe row (701) is connected to an external air source through the oxygen inlet pipe (703), and a flow regulating control valve is arranged on the oxygen inlet pipe (703).

14. The system according to claim 12, characterized in that: A plurality of oxygen jet pipe rows (701) are arranged from top to bottom in the lower part of the inner cavity of the oxygen cooling chamber (4), and a plurality of oxygen nozzles (702) are evenly arranged on each layer of the oxygen jet pipe row (701); the air inlets of the plurality of oxygen jet pipe rows (701) are connected to an external air source through independent oxygen inlet pipes (703).

15. The system according to claim 13, characterized in that: A plurality of oxygen jet pipe rows (701) are arranged from top to bottom in the lower part of the inner cavity of the oxygen cooling chamber (4), and a plurality of oxygen nozzles (702) are evenly arranged on each layer of the oxygen jet pipe row (701); the air inlets of the plurality of oxygen jet pipe rows (701) are connected to an external air source through independent oxygen inlet pipes (703).

16. The system according to claim 13, characterized in that: The carbon dioxide nozzle (502), the water vapor nozzle (602) and the oxygen nozzle (702) have the same structure, and all include a vertical nozzle and a conical pipe head, wherein a plurality of jet holes are evenly opened on the pipe wall of the vertical nozzle, and the conical pipe head is arranged at the top of the vertical nozzle; wherein: the bottom air inlet of the vertical nozzle of the carbon dioxide nozzle (502) is connected to the carbon dioxide jet pipe row (501); the bottom air inlet of the vertical nozzle of the water vapor nozzle (602) is connected to the water vapor jet pipe row (601); and the bottom air inlet of the vertical nozzle of the oxygen nozzle (702) is connected to the oxygen jet pipe row (701).

17. The system according to any one of claims 1-5, 7, 9-11, 14-16, characterized in that: A water-cooled wall (11) is also provided outside the oxygen cooling chamber (4), a cold water inlet is provided at the lower part of the water-cooled wall (11), and a steam outlet is provided at the upper part of the water-cooled wall (11).

18. The system according to claim 17, characterized in that: The steam outlet of the water-cooled wall (11) is connected to the steam inlet of the water steam injection mechanism (6) through a steam delivery pipeline (1101).

19. The system according to claim 18, characterized in that: The water-cooled wall (11) is a spiral water-cooled wall that surrounds the outside of the oxygen cooling chamber (4) from bottom to top.

20. The system according to any one of claims 1-5, 7, 9-11, 14-16, 18-19, characterized in that: Temperature detectors (12) are independently arranged in the calcining chamber (1), the carbon cooling chamber (2), the water cooling chamber (3) and the oxygen cooling chamber (4).

21. The system according to claim 20, characterized in that: The temperature detector (12) is a thermocouple.

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