Lime calcining system for carbon dioxide enrichment

Abstract

The utility model relates to a carbon dioxide enriched lime calcining system, which is a lime shaft kiln. A calcining chamber is arranged in the lime shaft kiln, the calcining chamber is sequentially divided into a plurality of combustion areas which are connected in series from top to bottom, and fuel injection combustion mechanisms are respectively and independently arranged in the combustion areas. According to the lime calcining system enriched with carbon dioxide, the calcining chamber is sequentially divided into a plurality of combustion areas connected in series from top to bottom, fuel and combustion-supporting gas are introduced into the calcining chamber in a segmented mode, the concentration of CO2 is controlled to be in a distribution mode that the concentration of CO2 is gradually increased from top to bottom, the inhibition effect of high-concentration CO2 on decomposition of CaCO3 is reduced, and the decomposition efficiency of CaCO3 is improved. The oxygen concentration of the middle-upper part of the calcining chamber is improved, and the burn-off rate and the utilization rate of fuel are improved.

Description

Technical Field

[0001] The utility model relates to a lime calcination system, in particular to a lime calcination system for carbon dioxide enrichment, belonging to the technical field of lime production. Background Technique

[0002] Active lime is an important industrial raw material, which is widely used and in huge demand in industries such as the steel industry, the calcium carbide industry, and alumina. In the past decade, the lime production in China has been increasing continuously. In 2020, the domestic lime production reached 300 million tons, and the generated CO2 emissions reached more than 330 million tons, making it a key object for CO2 emission reduction and carbon capture in the industrial field.

[0003] At present, the CO2 concentration in the tail-end flue gas generated by the conventional lime production process is relatively low, generally below 20%. Since the carbon capture cost increases with the decrease in the carbon dioxide concentration in the capture source, its carbon capture cost is as high as more than 300 yuan per ton of carbon dioxide, resulting in most manufacturers directly discharging the tail gas into the atmosphere, causing great resource waste and environmental pollution. Therefore, the too low tail-end CO2 concentration greatly restricts the large-scale application of carbon capture technology in lime kiln equipment.

[0004] In view of the above problems, technical personnel in the industry have proposed a carbon front-end enrichment technology, that is, by reducing or eliminating other gas components in the flue gas to obtain high-concentration CO2 flue gas, thereby greatly reducing the tail-end carbon capture cost and achieving near-zero emissions in lime production. The main technical feature of this method is to use pure oxygen + recycled flue gas for calcination to obtain high-concentration CO2 flue gas, and at the same time use recycled flue gas to replace cooling air to cool high-temperature lime.

[0005] However, the recycled flue gas contains a high concentration of CO2, which enters the calcination chamber from the top together with pure oxygen, and will have an obvious inhibitory effect on the decomposition reaction of limestone. This is because the main component of limestone is CaCO3, and its decomposition reaction equation is as follows:

[0006]

[0007] It can be seen from the above reaction equation that the decomposition reaction of limestone produces CO2, so the concentration of CO2 in the calcination chamber affects the forward progress of the limestone decomposition reaction. The relationship between the limestone decomposition reaction rate and the concentration of CO2 is as Figure 4 shown in the figure: It can be seen from the figure that the limestone decomposition reaction rate has an exponential function relationship with the CO2 concentration and partial pressure.

[0008] The existing lime kiln's oxygen-enriched combustion and flue gas circulation process has a single feeding and air intake method for fuel and combustion-supporting gas, which is basically a one-time input of fuel, and pure oxygen and flue gas are first mixed and then input into the kiln chamber or are input into the kiln chamber one after another, resulting in the entire furnace being filled with high-concentration CO2 gas, thereby inhibiting the decomposition of CaCO3 and significantly reducing the production efficiency of the lime kiln. Utility Model Content

[0009] In response to the problem in the prior art that the fuel and combustion-supporting gas feeding and air intake methods in the lime shaft kiln calcination process are single and basically input at one time, resulting in the combustion chamber being filled with CO2 gas, the utility model proposes a carbon dioxide enriched lime calcination system, which divides the calcination chamber into three areas according to the calcination process, and introduces fuel and combustion-supporting gas in multiple stages, and changes the distribution pattern of high-concentration CO2 in the whole chamber to a distribution pattern in which the CO2 concentration gradually increases from top to bottom, thereby reducing the CO2 concentration and CO2 partial pressure in the upper and middle part of the calcination chamber, reducing the inhibitory effect of high-concentration CO2 on the decomposition of CaCO3, and improving the lime production efficiency, fuel burnout rate and utilization rate.

[0010] According to an embodiment of the present invention, a carbon dioxide-enriched lime calcining system is provided.

[0011] A carbon dioxide-enriched lime calcining system is a lime shaft kiln. The lime shaft kiln is provided with a calcining chamber, which is divided into multiple combustion zones connected in series from top to bottom. Fuel injection combustion mechanisms are independently provided in each of the multiple combustion zones.

[0012] Preferably, the vertical heights of the plurality of combustion zones are the same or different. Preferably, the vertical heights of the plurality of combustion zones gradually increase from top to bottom.

[0013] Preferably, the calcining chamber is divided into a series of combustion zones I, II, and III from top to bottom. The fuel injection combustion mechanism includes a fuel nozzle and a combustion-supporting gas nozzle. Fuel nozzles and combustion-supporting gas nozzles are independently provided above combustion zone I, combustion zone II, and combustion zone III. Each fuel nozzle and combustion-supporting gas nozzle is equipped with a regulating valve. Preferably, the combustion-supporting gas nozzle is located above the fuel nozzle.

[0014] Preferably, the air inlet end of the combustion-supporting gas nozzle arranged at the upper part of the combustion zone I extends to the outside of the combustion zone I and is connected to the oxygen source.

[0015] Preferably, the air inlet end of the combustion-supporting gas nozzle arranged at the upper part of the combustion zone II is extended to the outside of the combustion zone II and then connected to the circulating flue gas source.

[0016] Preferably, the intake end of the combustion-supporting gas nozzle disposed at the upper part of the third combustion zone extends to the outside of the third combustion zone and is connected to the recycled flue gas source.

[0017] Preferably, the vertical heights of the first combustion zone, the second combustion zone, and the third combustion zone gradually increase from top to bottom. Preferably, the vertical height of the first combustion zone accounts for 10-20% of the overall vertical height of the calcination chamber, the vertical height of the second combustion zone accounts for 30-40% of the overall vertical height of the calcination chamber, and the vertical height of the third combustion zone accounts for 40-60% of the overall vertical height of the calcination chamber.

[0018] Preferably, one end of the fuel nozzle is connected to the fuel source, and the other end extends into the calcination chamber. Multiple fuel branch pipes are connected to the end of the fuel nozzle extending into the calcination chamber.

[0019] Preferably, multiple combustion-supporting gas branch pipes are connected to the end of the combustion-supporting gas nozzle extending into the calcination chamber.

[0020] Preferably, the combustion-supporting gas branch pipes are arranged above the fuel branch pipes.

[0021] Preferably, the fuel branch pipes are in an inverted "Y" shape. Preferably, fuel spray holes are provided on the lower side wall of the fuel branch pipes.

[0022] Preferably, the combustion-supporting gas branch pipes are in an inverted "Y" shape. Preferably, combustion-supporting gas spray holes are provided on the lower side wall of the combustion-supporting gas branch pipes.

[0023] Preferably, the aperture of the fuel branch pipes disposed at the edge of the calcination chamber is larger than the aperture of the fuel branch pipes disposed at the center of the calcination chamber.

[0024] Preferably, the aperture of the combustion-supporting gas branch pipes disposed at the edge of the calcination chamber is larger than the aperture of the combustion-supporting gas branch pipes disposed at the center of the calcination chamber.

[0025] Preferably, the length of the fuel branch pipes disposed at the edge of the calcination chamber is greater than the length of the fuel branch pipes disposed at the center of the calcination chamber.

[0026] Preferably, the length of the combustion-supporting gas branch pipes disposed at the edge of the calcination chamber is greater than the length of the combustion-supporting gas branch pipes disposed at the center of the calcination chamber.

[0027] Preferably, temperature monitoring devices and CO2 concentration monitoring devices are provided at the lower ends of each combustion zone.

[0028] In the present utility model, the calcination chamber is divided into a plurality of serially connected combustion zones from top to bottom, and a fuel injection combustion mechanism is arranged inside each combustion zone. Fuel and combustion-supporting gas are fed into the calcination chamber in sections to control the temperature and CO2 concentration in each area of the calcination chamber, reduce the CO2 concentration and partial pressure in the upper part of the calcination chamber, reduce the inhibitory effect of CO2 on the decomposition of CaCO3, and reduce the increase in the decomposition reaction temperature of calcium carbonate caused by CO2 enrichment and the fuel consumption of CO2 enrichment. At the same time, the fuel and oxygen are in full contact in the upper part of the calcination chamber, improving the burnout rate and utilization rate of the fuel. Preferably, to adapt to the release law of CO2 during the decomposition process of CaCO3, the heights of the plurality of combustion zones from top to bottom are set to gradually increase.

[0029] In the present utility model, the calcination chamber is divided into Combustion Zone I, Combustion Zone II and Combustion Zone III from top to bottom. A fuel nozzle and a combustion-supporting gas nozzle are provided at the upper end of each area, and regulating valves are provided on the fuel nozzle and the combustion-supporting gas nozzle. Preferably, according to the characteristics of the lime calcination process, the heights of Combustion Zone I, Combustion Zone II and Combustion Zone III are controlled to be 10-20%, 30-40% and 40-60% of the overall vertical height of the calcination chamber respectively, so that the CO2 concentration in the calcination chamber gradually increases from top to bottom, reducing the CO2 concentration and partial pressure in Combustion Zone I and Combustion Zone II, and improving the decomposition efficiency of calcium carbonate in the upper part of the calcination chamber. Preferably, the combustion-supporting gas nozzle is arranged above the fuel nozzle, and the fuel is quickly diluted and dispersed by the combustion-supporting gas injected from above after entering the calcination chamber, reducing local overheating or incomplete calcination during the lime calcination process.

[0030] In the present utility model, the combustion-supporting gas nozzle is controlled to feed only oxygen into Combustion Zone I, and only recycle flue gas into Combustion Zone II and Combustion Zone III, further reducing the CO2 concentration in Combustion Zone I. By controlling the amount of oxygen and recycle flue gas fed through the valve, the CO2 concentration in the calcination chamber gradually increases from top to bottom, and the temperature in the calcination chamber can also be controlled. In addition, the amount of fuel input into Combustion Zone I, Combustion Zone II and Combustion Zone III can be controlled through the fuel nozzle, which are 10% - 20%, 30% - 45% and 45% - 60% respectively, further controlling the temperature in each combustion zone, enriching CO2 at the lower end of Combustion Zone III, increasing the CO2 concentration in the flue gas, and at the same time, since part of the combustion-supporting gas uses recycle flue gas, increasing the CO2 concentration in the flue gas at the lower end of Combustion Zone III, the subsequent carbon capture cost can be reduced.

[0031] In the present utility model, the fuel injection pipe and the combustion-supporting gas injection pipe extending into the calcination chamber are respectively connected to multiple fuel branch pipes and combustion-supporting gas branch pipes, which improves the uniformity of the distribution of fuel and combustion-supporting gas. Preferably, the fuel branch pipe and / or the combustion-supporting gas branch pipe is arranged in an inverted "Y" shape structure, changing the existing vertically downward jetting of gas to jetting obliquely downward, so that the overall atmosphere inside the calcination chamber is more uniform and prevents the local oxygen or carbon dioxide concentration from being too high. Preferably, fuel injection holes and / or combustion-supporting gas injection holes are arranged on the lower side wall of the fuel branch pipe and / or the combustion-supporting gas branch pipe, preventing the injection holes from being blocked by the falling lime, and at the same time increasing the diffusion rate of the combustion-supporting gas in the combustion chamber and accelerating the dispersion of the fuel.

[0032] In the present utility model, the aperture of the fuel branch pipe and / or the combustion-supporting gas branch pipe at the edge of the calcination chamber is set to be larger than that of the fuel branch pipe and / or the combustion-supporting gas branch pipe at the center of the calcination chamber. Preferably, the length of the fuel branch pipe and / or the combustion-supporting gas branch pipe at the edge of the calcination chamber is set to be longer than that of the fuel branch pipe and / or the combustion-supporting gas branch pipe at the center of the calcination chamber. By spraying more fuel and / or combustion-supporting gas at the edge of the calcination chamber, the temperature at the edge of the calcination chamber is increased, and the temperature difference and CO2 concentration difference inside the calcination chamber are reduced.

[0033] In the present utility model, temperature monitoring devices and CO2 concentration monitoring devices are arranged inside the combustion zone I, combustion zone II and combustion zone III. According to the real-time temperature and CO2 concentration in each area inside the combustion chamber, the valves of the fuel injection pipe and the combustion-supporting gas injection pipe, as well as the type of gas injected by the combustion-supporting gas injection pipe in the combustion zone II, are adjusted so that the temperature and CO2 concentration in each area meet the calcination requirements. Among them, the volume fraction of CO2 in the flue gas generated after fuel combustion in the combustion zone I is controlled to be 15% - 25%, and the volume fraction of oxygen is 75% - 85%; the volume fraction of CO2 in the flue gas generated after fuel combustion in the combustion zone II is 55% - 70%, and the volume fraction of oxygen is 30% - 45%; the volume fraction of CO2 in the flue gas generated after fuel combustion in the combustion zone III is 70% - 99%, and the volume fraction of oxygen is 1% - 30%.

[0034] In the present utility model, in the distribution mode where the CO2 concentration in the calcination chamber gradually increases from top to bottom, reducing the CO2 concentration in the upper and middle part of the flue gas in the calcination chamber can significantly reduce the inhibitory effect of high-concentration CO2 on the decomposition of CaCO3, reduce the slowdown of the calcium carbonate decomposition reaction caused by CO2 enrichment, the increase in the temperature required for the reaction, and the fuel consumption caused by CO2 enrichment. At the same time, increasing the oxygen concentration in the upper and middle part of the calcination chamber enables the fuel to be in full contact with oxygen, improving the burnout rate and utilization rate of the fuel.

[0035] In the present utility model, the multiple series-connected combustion zones described in the claims are generally 2 to 15, preferably 2 to 8. One end of the fuel nozzle extending into the calcination chamber is connected to multiple fuel branch pipes. The multiple fuel branch pipes are generally 2 to 10, preferably 3 to 8. One end of the combustion-supporting gas nozzle extending into the calcination chamber is connected to multiple combustion-supporting gas branch pipes. The multiple combustion-supporting gas branch pipes are generally 2 to 10, preferably 3 to 8.

[0036] Compared with the prior art, the present utility model has the following beneficial effects:

[0037] 1. A lime calcination system for carbon dioxide enrichment provided by the present utility model divides the calcination chamber into multiple series-connected combustion zones from top to bottom, and separately introduces fuel and combustion-supporting gas into the calcination chamber, controlling the CO2 concentration to be in a distribution pattern that gradually increases from top to bottom, reducing the inhibitory effect of high-concentration CO2 on the decomposition of CaCO3, increasing the oxygen concentration in the upper and middle parts of the calcination chamber, and improving the burnout rate and utilization rate of the fuel.

[0038] 2. A lime calcination system for carbon dioxide enrichment provided by the present utility model sets the ends of the fuel nozzle and the combustion-supporting gas nozzle extending into the calcination chamber as an inverted "Y" shape, and opens fuel injection holes and combustion-supporting gas injection holes, accelerating the diffusion rate of the combustion-supporting gas in the calcination chamber, enabling the fuel to be quickly dispersed and evenly burned, and improving the uniformity of limestone calcination and the average quality of lime. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of a lime calcination system for carbon dioxide enrichment provided by the present utility model.

[0040] Figure 2 It is a schematic structural diagram of the fuel branch pipe in a lime calcination system for carbon dioxide enrichment provided by the present utility model.

[0041] Figure 3 It is a schematic structural diagram of the combustion-supporting gas branch pipe in a lime calcination system for carbon dioxide enrichment provided by the present utility model.

[0042] Figure 4 It is a relationship diagram between the decomposition reaction rate of limestone and the concentration of CO2 in the prior art.

[0043] Reference numerals: A: lime shaft kiln; A1: combustion zone I; A2: combustion zone II; A3: combustion zone III; 1: fuel nozzle; 2: combustion-supporting gas nozzle; 3: oxygen source; 4: recycled flue gas source; 5: fuel branch pipe; 6: combustion-supporting gas branch pipe; 7: fuel injection hole; 8: combustion-supporting gas injection hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The technical solution of the present utility model will be illustrated by way of example below. The scope of protection claimed by the present utility model includes but is not limited to the following embodiments.

[0045] According to an embodiment of the present utility model, a lime calcination system for carbon dioxide enrichment is provided.

[0046] A lime calcination system for carbon dioxide enrichment, and the system is a lime shaft kiln A. A calcination chamber is provided inside the lime shaft kiln A, and the calcination chamber is sequentially divided into a plurality of series-connected combustion zones from top to bottom. Fuel injection combustion mechanisms are independently provided inside the plurality of combustion zones.

[0047] Preferably, the vertical heights of the plurality of combustion zones are the same or different. Preferably, the vertical heights of the plurality of combustion zones gradually increase from top to bottom.

[0048] Preferably, the calcination chamber is divided into a combustion zone I A1, a combustion zone II A2, and a combustion zone III A3 that are sequentially connected in series from top to bottom. The fuel injection combustion mechanism includes a fuel injection pipe 1 and a combustion-supporting gas injection pipe 2. A fuel injection pipe 1 and a combustion-supporting gas injection pipe 2 are independently provided above the upper part of the combustion zone I A1, above the upper part of the combustion zone II A2, and above the upper part of the combustion zone III A3. Adjusting valves are provided on all the fuel injection pipes 1 and the combustion-supporting gas injection pipes 2. Preferably, the combustion-supporting gas injection pipe 2 is provided above the fuel injection pipe 1.

[0049] Preferably, the intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone I A1 extends outside the combustion zone I A1 and is connected to an oxygen source 3.

[0050] Preferably, the intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone II A2 extends outside the combustion zone II A2 and is connected to a recycled flue gas source 4.

[0051] Preferably, the intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone III A3 extends outside the combustion zone III A3 and is connected to the recycled flue gas source 4.

[0052] Preferably, the vertical heights of the combustion zone I A1, the combustion zone II A2, and the combustion zone III A3 gradually increase from top to bottom. Preferably, the vertical height of the combustion zone I A1 accounts for 10-20% of the overall vertical height of the calcination chamber, the vertical height of the combustion zone II A2 accounts for 30-40% of the overall vertical height of the calcination chamber, and the vertical height of the combustion zone III A3 accounts for 40-60% of the overall vertical height of the calcination chamber.

[0053] Preferably, one end of the fuel injection pipe 1 is connected to a fuel source, and the other end extends into the calcination chamber. A plurality of fuel branch pipes 5 are connected to the end of the fuel injection pipe 1 that extends into the calcination chamber.

[0054] Preferably, one end of the combustion-supporting gas nozzle 2 extending into the calcination chamber is connected with a plurality of combustion-supporting gas branch pipes 6.

[0055] Preferably, the combustion-supporting gas branch pipes 6 are arranged above the fuel branch pipes 5.

[0056] Preferably, the fuel branch pipe 5 is in an inverted "Y" shape. Preferably, fuel injection holes 7 are arranged on the lower side wall of the fuel branch pipe 5.

[0057] Preferably, the combustion-supporting gas branch pipe 6 is in an inverted "Y" shape. Preferably, combustion-supporting gas injection holes 8 are arranged on the lower side wall of the combustion-supporting gas branch pipe 6.

[0058] Preferably, the aperture of the fuel branch pipe 5 arranged at the edge of the calcination chamber is larger than that of the fuel branch pipe 5 arranged at the center of the calcination chamber.

[0059] Preferably, the aperture of the combustion-supporting gas branch pipe 6 arranged at the edge of the calcination chamber is larger than that of the combustion-supporting gas branch pipe 6 arranged at the center of the calcination chamber.

[0060] Preferably, the length of the fuel branch pipe 5 arranged at the edge of the calcination chamber is greater than that of the fuel branch pipe 5 arranged at the center of the calcination chamber.

[0061] Preferably, the length of the combustion-supporting gas branch pipe 6 arranged at the edge of the calcination chamber is greater than that of the combustion-supporting gas branch pipe 6 arranged at the center of the calcination chamber.

[0062] Preferably, a temperature monitoring device and a CO2 concentration monitoring device are arranged at the lower end of each combustion zone.

[0063] Example 1

[0064] A lime calcination system for carbon dioxide enrichment, and this system is a lime shaft kiln A. A calcination chamber is arranged inside the lime shaft kiln A, and the calcination chamber is sequentially divided into 3 series-connected combustion zones from top to bottom, and fuel injection combustion mechanisms are independently arranged in the 3 combustion zones.

[0065] Example 2

[0066] Repeat Example 1, except that the vertical heights of the 3 combustion zones are different. The vertical heights of the 3 combustion zones gradually increase from top to bottom.

[0067] Example 3

[0068] Repeat Example 2, except that the calcination chamber is divided from top to bottom into a combustion zone I A1, a combustion zone II A2, and a combustion zone III A3 that are connected in series in sequence. The fuel injection combustion mechanism includes a fuel injection pipe 1 and a combustion-supporting gas injection pipe 2. Fuel injection pipes 1 and combustion-supporting gas injection pipes 2 are independently provided above the upper part of the combustion zone I A1, above the upper part of the combustion zone II A2, and above the upper part of the combustion zone III A3. Adjusting valves are provided on all the fuel injection pipes 1 and combustion-supporting gas injection pipes 2. The combustion-supporting gas injection pipe 2 is arranged above the fuel injection pipe 1.

[0069] Example 4

[0070] Repeat Example 3, except that the intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone I A1 extends outside the combustion zone I A1 and is connected to an oxygen source 3.

[0071] The intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone II A2 extends outside the combustion zone II A2 and is connected to a recycled flue gas source 4.

[0072] The intake end of the combustion-supporting gas injection pipe 2 provided above the upper part of the combustion zone III A3 extends outside the combustion zone III A3 and is connected to the recycled flue gas source 4.

[0073] Example 5

[0074] Repeat Example 4, except that the vertical heights of the combustion zone I A1, the combustion zone II A2, and the combustion zone III A3 gradually increase from top to bottom. The vertical height of the combustion zone I A1 accounts for 15% of the overall vertical height of the calcination chamber, the vertical height of the combustion zone II A2 accounts for 35% of the overall vertical height of the calcination chamber, and the vertical height of the combustion zone III A3 accounts for 50% of the overall vertical height of the calcination chamber.

[0075] Example 6

[0076] Repeat Example 5, except that one end of the fuel injection pipe 1 is connected to a fuel source, and the other end extends into the calcination chamber. Five fuel branch pipes 5 are connected to the end of the fuel injection pipe 1 that extends into the calcination chamber.

[0077] Example 7

[0078] Repeat Example 6, except that five combustion-supporting gas branch pipes 6 are connected to the end of the combustion-supporting gas injection pipe 2 that extends into the calcination chamber.

[0079] The combustion-supporting gas branch pipes 6 are arranged above the fuel branch pipes 5.

[0080] Example 8

[0081] Repeat Example 7, except that the fuel branch pipe 5 has an inverted "Y" shape. Fuel injection holes 7 are provided on the lower side wall of the fuel branch pipe 5.

[0082] The combustion-supporting gas branch pipe 6 has an inverted "Y" shape. Combustion-supporting gas spray holes 8 are provided on the lower side wall of the combustion-supporting gas branch pipe 6.

[0083] Example 9

[0084] Repeat Example 8, except that the aperture of the fuel branch pipe 5 provided at the edge of the calcination chamber is larger than the aperture of the fuel branch pipe 5 provided at the center of the calcination chamber.

[0085] The aperture of the combustion-supporting gas branch pipe 6 provided at the edge of the calcination chamber is larger than the aperture of the combustion-supporting gas branch pipe 6 provided at the center of the calcination chamber.

[0086] Example 10

[0087] Repeat Example 9, except that the length of the fuel branch pipe 5 provided at the edge of the calcination chamber is greater than the length of the fuel branch pipe 5 provided at the center of the calcination chamber.

[0088] The length of the combustion-supporting gas branch pipe 6 provided at the edge of the calcination chamber is greater than the length of the combustion-supporting gas branch pipe 6 provided at the center of the calcination chamber.

[0089] Example 11

[0090] Repeat Example 10, except that temperature monitoring devices and CO2 concentration monitoring devices are provided at the lower ends of each combustion zone.

Claims

1. A lime calcination system for carbon dioxide enrichment, characterized in that: The system is a lime shaft kiln (A); inside the lime shaft kiln (A), there is a calcination chamber, which is successively divided into multiple series-connected combustion zones from top to bottom, and fuel injection combustion mechanisms are independently arranged inside the multiple combustion zones.

2. The system according to claim 1, wherein: The vertical heights of the multiple combustion zones are the same or different.

3. The system according to claim 2, characterized in that: The vertical heights of the multiple combustion zones gradually increase from top to bottom.

4. The system according to any one of claims 1 to 3, characterized in that: The calcination chamber is divided into combustion zone I (A1), combustion zone II (A2), and combustion zone III (A3) connected in series from top to bottom; the fuel injection combustion mechanism includes a fuel injection pipe (1) and a combustion-supporting gas injection pipe (2); fuel injection pipes (1) and combustion-supporting gas injection pipes (2) are independently arranged above the upper part of combustion zone I (A1), above the upper part of combustion zone II (A2), and above the upper part of combustion zone III (A3); regulating valves are arranged on all the fuel injection pipes (1) and combustion-supporting gas injection pipes (2).

5. The system according to claim 4, wherein: The combustion-supporting gas injection pipe (2) is arranged above the fuel injection pipe (1).

6. The system according to claim 4, wherein: The intake end of the combustion-supporting gas injection pipe (2) arranged above the upper part of combustion zone I (A1) extends outside combustion zone I (A1) and is connected to an oxygen source (3); and / or The intake end of the combustion-supporting gas injection pipe (2) arranged above the upper part of combustion zone II (A2) extends outside combustion zone II (A2) and is connected to a recycled flue gas source (4); and / or The intake end of the combustion-supporting gas injection pipe (2) arranged above the upper part of combustion zone III (A3) extends outside combustion zone III (A3) and is connected to a recycled flue gas source (4).

7. The system according to claim 4, wherein: The vertical heights of combustion zone I (A1), combustion zone II (A2), and combustion zone III (A3) gradually increase from top to bottom.

8. The system according to claim 5 or 6, characterized in that: The vertical heights of combustion zone I (A1), combustion zone II (A2), and combustion zone III (A3) gradually increase from top to bottom.

9. The system according to claim 7, wherein: The vertical height of combustion zone I (A1) accounts for 10 - 20% of the overall vertical height of the calcination chamber, the vertical height of combustion zone II (A2) accounts for 30 - 40% of the overall vertical height of the calcination chamber, and the vertical height of combustion zone III (A3) accounts for 40 - 60% of the overall vertical height of the calcination chamber.

10. The system according to claim 8, wherein: The vertical height of combustion zone I (A1) accounts for 10 - 20% of the overall vertical height of the calcination chamber, the vertical height of combustion zone II (A2) accounts for 30 - 40% of the overall vertical height of the calcination chamber, and the vertical height of combustion zone III (A3) accounts for 40 - 60% of the overall vertical height of the calcination chamber.

11. The system according to claim 4, wherein: One end of the fuel injection pipe (1) is connected to a fuel source, and the other end extends into the calcination chamber; multiple fuel branch pipes (5) are connected to the end of the fuel injection pipe (1) extending into the calcination chamber; and / or Multiple combustion-supporting gas branch pipes (6) are connected to the end of the combustion-supporting gas injection pipe (2) extending into the calcination chamber.

12. The system according to any one of claims 5-7, 9-10, characterized in that: One end of the fuel injection pipe (1) is connected to a fuel source, and the other end extends into the calcination chamber; multiple fuel branch pipes (5) are connected to the end of the fuel injection pipe (1) extending into the calcination chamber; and / or Multiple combustion-supporting gas branch pipes (6) are connected to the end of the combustion-supporting gas injection pipe (2) extending into the calcination chamber.

13. The system according to claim 11, wherein: The combustion-supporting gas branch pipes (6) are arranged above the fuel branch pipes (5).

14. The system according to claim 12, characterized in that: The combustion-supporting gas branch pipe (6) is arranged above the fuel branch pipe (5).

15. The system according to claim 11, wherein: The fuel branch pipe (5) is of an inverted "Y" shape; and / or The combustion-supporting gas branch pipe (6) is of an inverted "Y" shape.

16. The system according to claim 12, wherein: The fuel branch pipe (5) is of an inverted "Y" shape; and / or The combustion-supporting gas branch pipe (6) is of an inverted "Y" shape.

17. The system according to claim 15 or 16, characterized in that: Fuel injection holes (7) are provided on the lower side wall of the fuel branch pipe (5); and / or Combustion-supporting gas injection holes (8) are provided on the lower side wall of the combustion-supporting gas branch pipe (6).

18. The system according to any one of claims 11, 13 - 16, characterized in that: The aperture of the fuel branch pipe (5) arranged at the edge of the calcination chamber is larger than the aperture of the fuel branch pipe (5) arranged at the center of the calcination chamber; and / or The aperture of the combustion-supporting gas branch pipe (6) arranged at the edge of the calcination chamber is larger than the aperture of the combustion-supporting gas branch pipe (6) arranged at the center of the calcination chamber.

19. The system according to claim 12, characterized in that: The aperture of the fuel branch pipe (5) arranged at the edge of the calcination chamber is larger than the aperture of the fuel branch pipe (5) arranged at the center of the calcination chamber; and / or The aperture of the combustion-supporting gas branch pipe (6) arranged at the edge of the calcination chamber is larger than the aperture of the combustion-supporting gas branch pipe (6) arranged at the center of the calcination chamber.

20. The system according to any one of claims 11, 13 - 16, 19, characterized in that: The length of the fuel branch pipe (5) arranged at the edge of the calcination chamber is greater than the length of the fuel branch pipe (5) arranged at the center of the calcination chamber; and / or The length of the combustion-supporting gas branch pipe (6) arranged at the edge of the calcination chamber is greater than the length of the combustion-supporting gas branch pipe (6) arranged at the center of the calcination chamber.

21. The system according to claim 12, wherein: The length of the fuel branch pipe (5) arranged at the edge of the calcination chamber is greater than the length of the fuel branch pipe (5) arranged at the center of the calcination chamber; and / or The length of the combustion-supporting gas branch pipe (6) arranged at the edge of the calcination chamber is greater than the length of the combustion-supporting gas branch pipe (6) arranged at the center of the calcination chamber.

22. The system according to any one of claims 1-3, 5-7, 9-11, 13-16, 19, 21, characterized in that: Temperature monitoring devices and CO2 concentration monitoring devices are provided at the lower end of each combustion zone.

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