Lime calcining device

Abstract

The utility model provides a lime calcining device, which belongs to the technical field of lime calcining and comprises a shaft kiln, a heating combustion system and a carbon dioxide recovery system. The shaft kiln sequentially comprises a preheating section, first sealing equipment, a calcining section, second sealing equipment, a cooling section and a combustion chamber arranged outside the calcining section in a surrounding mode from top to bottom. A carbon dioxide outlet is formed in the calcining section; a discharging opening is formed in the bottom of the cooling section; the heating combustion system comprises an A-side heat accumulating type burner and a B-side heat accumulating type burner which are arranged on the two sides of the combustion chamber respectively, air supply equipment and a gas pipeline. The carbon dioxide recovery system comprises a waste heat recovery device connected with the carbon dioxide outlet, a first dust removal device and a carbon dioxide recovery process system. According to the utility model, the problems of low CO2 gas concentration, low utilization value, easy resource waste and the like caused by mixing of pure carbon dioxide decomposed from calcium carbonate and tail gas generated by fuel combustion when limestone is calcined in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lime calcination, and more specifically, to a lime calcination device. Background Art

[0002] In the fields of metallurgy, chemical industry and many production fields, it is a common production process adopted by most production enterprises to widely use the calcium oxide products obtained by calcining limestone in a lime kiln. From the main popular lime kilns, whether it is a shaft kiln, a Maerz kiln, a rotary kiln, a double-beam kiln or a mechanized mixed firing kiln, no matter what kind of normal fuel (liquid, gas, solid) is selected, or what kind of calcination method is adopted, the raw fuel is mixed and the heat energy for the decomposition of limestone is provided by the fuel combustion. There are more or less defects in aspects such as heat energy utilization, product application, and resource utilization.

[0003] First, the temperature of the decomposition of limestone cannot be constant. CaCO 3 reaches complete decomposition at a temperature of 1150 °C Celsius and the decomposition rate reaches the fastest. If the temperature cannot be stabilized at the critical state, the phenomenon of "underburning and overburning" will occur during the calcination of limestone. Second, the pure carbon dioxide decomposed from calcium carbonate is not well recovered and utilized because it is mixed with the tail gas generated by fuel combustion. CaCO 3 The decomposed CO 2 is mixed with the tail gas of the fuel mixed firing and the combustion-supporting air. The concentration of the CO 2 gas is low, only about 30% or so, and its utilization value is not high. If gas separation or recovery and utilization are carried out, a lot of purification process equipment will be added, the investment is huge, and the production cost of the enterprise will be increased. Most enterprises have chosen to directly discharge after dust removal instead of utilization. Third, the limitation of the limestone particle size of different kilns fails to fully utilize the limestone resources. The limestone particle sizes utilized by different kilns are mainly concentrated in 30mm - 60mm; 40mm - 80mm; 60mm - 90mm. The limestone below 30mm cannot be basically utilized in the lime kiln, resulting in a large amount of waste of resources. Content of the Utility Model

[0004] In view of the above problems, the purpose of the utility model is to provide a lime calcination device to solve the problems in the prior art that during the calcination of limestone, the pure carbon dioxide decomposed from calcium carbonate is mixed with the tail gas generated by fuel combustion, resulting in a low concentration of CO 2 gas, low utilization value, and easy resource waste.

[0005] The utility model provides a lime calcination device, including a shaft kiln, a heating and combustion system, and a carbon dioxide recovery system; wherein,

[0006] The vertical kiln includes a preheating section, a first sealing device provided at the lower end of the preheating section, a calcination section provided at the lower end of the first sealing device, a second sealing device provided at the lower end of the calcination section, a combustion chamber surrounding the outside of the calcination section, and a cooling section provided at the lower end of the second sealing device;

[0007] A charging port is provided at the top of the preheating section; a preheating air inlet and a preheating waste gas outlet are provided on the preheating section; a carbon dioxide outlet is provided on the calcination section; a cooling air inlet and a preheating air outlet are provided on the cooling section, and a discharge port is provided at the bottom of the cooling section; a finished product belt conveyor is provided below the discharge port;

[0008] When the first sealing device is in an open state, a first material discharge port is formed between the preheating section and the calcination section; when the first sealing device is in a closed state, the preheating section and the calcination section are sealed and separated by the first sealing device;

[0009] When the second sealing device is in an open state, a second material discharge port is formed between the calcination section and the cooling section; when the second sealing device is in a closed state, the calcination section and the cooling section are sealed and separated by the second sealing device;

[0010] The heating combustion system includes an A-side regenerative burner and a B-side regenerative burner respectively provided on both sides of the combustion chamber, as well as an air supply device and a gas pipeline; a first reversing valve is provided on the air main pipe of the air supply device; a second reversing valve is provided at the outlet of the gas pipeline; the air inlets of the A-side regenerative burner and the B-side regenerative burner are respectively connected to two ports of the first reversing valve through air pipelines; the gas inlets of the A-side regenerative burner and the B-side regenerative burner are respectively connected to two ports of the second reversing valve through gas branch pipelines;

[0011] The carbon dioxide recovery system includes a waste heat recovery device connected to the carbon dioxide outlet through a pipeline, a first dust removal device connected to the waste heat recovery device, and a carbon dioxide recovery process system connected to the first dust removal device.

[0012] In addition, a preferred solution is that a feeding system is further included; wherein,

[0013] The feeding system includes: a kiln top bin provided above the preheating section, an inclined bridge provided on one side of the kiln top bin, and a trolley provided on the inclined bridge and capable of moving along the inclined bridge;

[0014] One end of the inclined bridge is provided on the ground, and the other end is provided above the kiln top bin.

[0015] In addition, a preferred solution is that a feeding position is provided on one side of the feeding port of the preheating section; a transport track is provided at the top of the preheating section; the transport track is arranged between the feeding position and the kiln top bin; and a feeding vehicle is arranged on the transport track.

[0016] In addition, a preferred solution is that a raw material discharge valve is provided at the bottom of the kiln top bin; a radar level gauge is provided on the kiln top bin; the radar level gauge is connected to a main control computer device; and the main control computer device is in signal connection with the raw material discharge valve.

[0017] In addition, a preferred solution is that a thermocouple is provided in the calcination section; the thermocouple is connected to the main control computer device; and the main control computer device is in signal connection with a switch provided on the gas pipeline.

[0018] In addition, a preferred solution is that a waste heat reuse system is further included; wherein,

[0019] The waste heat reuse system includes a preheating air conveying pipeline connected to the high-temperature cooling air outlet of the cooling section and a high-temperature fan arranged on the preheating air conveying pipeline;

[0020] The air outlet of the preheating air conveying pipeline is connected to the preheating air inlet on the preheating section.

[0021] In addition, a preferred solution is that a cooling fan is connected to the cooling air inlet of the cooling section.

[0022] In addition, a preferred solution is that an exhaust gas treatment system is further included; wherein,

[0023] The exhaust gas treatment system includes an exhaust gas main pipe, a second dust removal device connected to the exhaust gas outlet of the exhaust gas main pipe, an exhaust gas fan connected to the second dust removal device, and a chimney connected to the exhaust gas fan; a third reversing valve is provided at the exhaust gas collection end of the exhaust gas main pipe; two ports of the third reversing valve are respectively connected to the exhaust gas outlets of the A-side regenerative burner and the B-side regenerative burner; and the preheating exhaust gas outlet of the preheating section is connected to the exhaust gas main pipe.

[0024] In addition, a preferred solution is that the first dust removal device is a bag filter; and / or, the second dust removal device is a bag filter; and / or, the waste heat recovery device is a waste heat boiler; and / or, the air supply equipment is a combustion-supporting fan.

[0025] In addition, a preferred solution is that a first air cap is provided at the preheating air inlet; and / or, a second air cap is provided at the cooling air inlet.

[0026] As can be seen from the above technical solution, the lime calcination device provided by the present utility model separates the preheating, calcination, and cooling of the limestone raw material through the structural design of the shaft kiln and utilizes the first sealing device and the second sealing device to ensure that the waste gas generated by preheating and cooling is separated from the thermal decomposition of calcium carbonate, thereby obtaining high-purity carbon dioxide; combined with the internal and external structural arrangements of the calcination section and the combustion chamber, the limestone is thermally decomposed into CaO and CO 2 to further ensure the high purity of CaO and CO 2 . The concentration of the obtained carbon dioxide gas is as high as 99% (dry basis), and the value of the high-value-added carbon dioxide product is much higher than the value of the lime itself; the internal and external arrangements of the heating combustion system can also reduce the erosion of the refractory materials inside the calcination section by the high-temperature gas flow, and can extend the service life of the refractory materials; and by using the shaft kiln in the present utility model to calcine limestone, the limestone with a particle size of 5 mm - 20 mm abandoned in the limestone mine can be reused, effectively improving the resource utilization rate;

[0027] Through the structural design of the heating combustion system, the reversing valve can be used to make the regenerative burners on side A and side B work alternately. When the regenerative burner on one side is working, the regenerative burner on the opposite side stores heat, forming a cyclic operation in the heating process. While making full use of the combustion waste heat, it is also convenient to control the thermal decomposition temperature inside the calcination section to be in an approximate "constant" state, effectively preventing the occurrence of the "overburning and underburning" phenomenon, and the overburning rate of the calcium oxide product is ≤ 1%;

[0028] Through the design of the carbon dioxide recovery system, the high-temperature carbon dioxide gas (about 1000 °C) generated in the calcination section is first subjected to waste heat recovery by the waste heat recovery device and then dust removal by the first dust removal device. The clean and low-temperature carbon dioxide gas is purified, cooled, and pressurized through the carbon dioxide recovery process system to be transformed into liquid carbon dioxide and then canned for recycling, further making full use of the waste heat generated by the carbon dioxide gas, with remarkable energy-saving effect. The present utility model can achieve the maximum utilization of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By referring to the following description in conjunction with the drawings, and with a more comprehensive understanding of the present utility model, other objects and results of the present utility model will become clearer and easier to understand. In the drawings:

[0030] Figure 1 is a schematic structural diagram of a lime calcination device according to an embodiment of the present utility model;

[0031] Figure 2 is a schematic structural diagram of a shaft kiln according to an embodiment of the present utility model;

[0032] Figure 3Schematic structural diagram of a heating combustion system according to an embodiment of the present utility model;

[0033] Figure 4 Method flow chart for lime calcination using the lime calcination device according to an embodiment of the present utility model.

[0034] In the drawings, 11 - preheating section, 111 - first air cap, 112 - preheating waste gas pipeline, 12 - first sealing device, 13 - calcination section, 14 - second sealing device, 15 - combustion chamber, 16 - cooling section, 161 - cooling fan, 162 - second air cap, 163 - discharge valve, 17 - finished product belt conveyor, 21 - A - side regenerative burner, 22 - B - side regenerative burner, 23 - air supply device, 24 - gas pipeline, 25 - first reversing valve, 26 - second reversing valve, 31 - waste heat recovery device, 311 - steam drum, 312 - plant pipe network, 32 - first dust removal device, 33 - carbon dioxide recovery process system, 34 - process fan, 41 - kiln top bin, 411 - raw material discharge valve, 42 - inclined bridge, 43 - skip car, 44 - charging car, 51 - preheating air conveying pipeline, 52 - high - temperature fan, 61 - waste gas main pipe, 62 - second dust removal device, 63 - waste gas fan, 64 - chimney, 65 - third reversing valve.

[0035] In all the drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed description of the specific embodiment

[0036] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is obvious that these embodiments can also be implemented without these specific details.

[0037] Regarding the aforementioned prior art, in the process of limestone calcination, the pure carbon dioxide decomposed from calcium carbonate is mixed with the tail gas generated by fuel combustion, resulting in a low concentration of CO 2 gas, low utilization value, and easy resource waste and other problems, and a lime calcination device is proposed.

[0038] The following will describe in detail the specific embodiments of the present utility model with reference to the accompanying drawings.

[0039] In order to illustrate the lime calcination device provided by the present utility model, Figure 1 shows the structure of the lime calcination device according to an embodiment of the present utility model; Figure 2 shows the structure of the shaft kiln according to an embodiment of the present utility model; Figure 3 shows the structure of the heating combustion system according to an embodiment of the present utility model; Figure 4 shows the method flow for lime calcination using the lime calcination device according to an embodiment of the present utility model.

[0040] As Figures 1 to 4 Collectively shown, the lime calcination device provided by the present utility model includes a vertical kiln, a heating combustion system, and a carbon dioxide recovery system; among them,

[0041] The vertical kiln includes a preheating section 11, a first sealing device 12 provided at the lower end of the preheating section 11, a calcination section 13 provided at the lower end of the first sealing device 12, a second sealing device 14 provided at the lower end of the calcination section 13, a combustion chamber 15 surrounding the outside of the calcination section 14, and a cooling section 16 provided at the lower end of the second sealing device 14;

[0042] A feeding port is provided at the top of the preheating section 11; a preheating air inlet and a preheating waste gas outlet are provided on the preheating section 11; a carbon dioxide outlet is provided on the calcination section 13; a cooling air inlet and a preheating air outlet are provided on the cooling section 16, and a discharge port is provided at the bottom of the cooling section 16; a finished product belt conveyor 17 is provided below the discharge port;

[0043] When the first sealing device 12 is in the open state, a first blanking port is formed between the preheating section 11 and the calcination section 13; when the first sealing device 12 is in the closed state, the preheating section 11 and the calcination section 13 are sealed and separated by the first sealing device 12;

[0044] When the second sealing device 14 is in the open state, a second blanking port is formed between the calcination section 13 and the cooling section 16; when the second sealing device 14 is in the closed state, the calcination section 13 and the cooling section 16 are sealed and separated by the second sealing device 14;

[0045] The heating combustion system includes an A-side regenerative burner 21 and a B-side regenerative burner 22 respectively provided on both sides of the combustion chamber 15, an air supply device 23, and a gas pipeline 24; a first reversing valve 25 is provided on the air main pipe of the air supply device 23; a second reversing valve 26 is provided at the outlet of the gas pipeline 24; the air inlets of the A-side regenerative burner 21 and the B-side regenerative burner 22 are respectively connected to the two ports of the first reversing valve 25 through air pipelines; the gas inlets of the A-side regenerative burner 21 and the B-side regenerative burner 22 are respectively connected to the two ports of the second reversing valve 26 through gas branch pipelines;

[0046] The carbon dioxide recovery system includes a waste heat recovery device 31 connected to the carbon dioxide outlet through a pipeline, a first dust removal device 32 connected to the waste heat recovery device 31, and a carbon dioxide recovery process system 33 connected to the first dust removal device 32.

[0047] Specifically, in order to facilitate the feeding of the dedusted carbon dioxide into the carbon dioxide recovery process system 33, a process fan 34 is provided between the first dust removal device 32 and the carbon dioxide recovery process system 33.

[0048] The first sealing device 12 can be selected as a sealing gate valve resistant to medium temperature; the second sealing device 14 can be selected as a sealing gate valve resistant to high temperature; the medium temperature or high temperature resistance of the sealing gate valve can be made of corresponding refractory materials according to actual needs. When the first sealing device 12 and the second sealing device 14 are closed, the adjacent two sections of the adjacent shaft kiln are separated to form an independent closed working section. When opened, the two sections are connected to form a charging port. The opening and closing of the first sealing device 12 and the second sealing device 14 can be set to be hydraulic or electric control type, controlled by setting a control switch in the control room, or connected to the main control computer device to achieve automatic control through setting a time program.

[0049] Through the structural design of the shaft kiln, using the first sealing device 12 and the second sealing device 14, the preheating, calcination and cooling of the limestone raw material are separated, ensuring that the waste gas generated by preheating and cooling is separated from the thermal decomposition of calcium carbonate, so as to obtain high-purity carbon dioxide; combined with the internal and external structural layout of the calcination section 13 and the combustion chamber 15, the limestone is thermally decomposed into CaO and CO 2 to further ensure the high purity of CaO and CO 2 ; the concentration of the obtained carbon dioxide gas is as high as 99% (dry basis), and the value of the high-value carbon dioxide product is much higher than the value of lime itself; the internal and external layout of the heating combustion system can also reduce the erosion of the high-temperature gas flow on the internal refractory material of the calcination section 13 and can extend the service life of the refractory material; and by using the shaft kiln in the present utility model to calcine limestone, the limestone with a particle size of 5 mm - 20 mm abandoned in the limestone mine can be reused, effectively improving the resource utilization rate;

[0050] Through the structural design of the heating combustion system, the reversing valve can be used to make the A-side regenerative burner 21 and the B-side regenerative burner 22 work alternately. When one side of the regenerative burner works, the regenerative burner on the opposite side stores heat, forming a cyclic operation in the heating process. While making full use of the combustion waste heat, it is also convenient to control the thermal decomposition temperature in the calcination section 13 to be in an approximate "constant" state, effectively preventing the occurrence of the phenomenon of "underburning and overburning", and the underburning and overburning rate of the calcium oxide product is ≤ 1%;

[0051] Through the design of the carbon dioxide recovery system, the high-temperature carbon dioxide gas (about 1000 °C) generated in the calcination section 13 is first subjected to waste heat recovery by the waste heat recovery device 31 and then dust-removed by the first dust removal device 32. The clean and low-temperature carbon dioxide gas is purified, cooled, and pressurized through the carbon dioxide recovery process system 33 to be transformed into liquid carbon dioxide and then canned for recycling. The waste heat generated by the carbon dioxide gas is further fully utilized, and the energy-saving effect is remarkable. The utility model can achieve the maximum utilization of resources.

[0052] As a preferred embodiment of the utility model, it further includes a feeding system; wherein, the feeding system includes: a kiln top bin 41 arranged above the preheating section 11, a ramp 42 arranged on one side of the kiln top bin 41, and a trolley 43 arranged on the ramp 42 and capable of moving along the ramp 42; one end of the ramp 42 is arranged on the ground, and the other end is arranged above the kiln top bin 41.

[0053] Specifically, by arranging the kiln top bin 41 above the preheating section 11, the raw materials to be calcined and decomposed can be temporarily stored, which is convenient for the subsequent continuous operation of the device. Through the structural design of the trolley 43 and the ramp 42, it is convenient to transport the raw materials on the ground into the kiln top bin 41. Of course, this is a preferred embodiment of the utility model. The transportation of raw materials can adopt the method of transporting as needed or can be replaced by the method of hoisting by equipment. It can be seen that the technical solution provided in this embodiment is not the only technical solution of the utility model. Therefore, the utility model does not make special limitations on this.

[0054] As a preferred embodiment of the utility model, a feeding position is arranged on one side of the feeding port of the preheating section 11; a transportation track is arranged at the top of the preheating section; the transportation track is arranged between the feeding position and the kiln top bin 41; and a feeding trolley 44 is arranged on the transportation track.

[0055] Specifically, the qualified granularity limestone raw materials are transported by the trolley 43 through the ramp 42 to the kiln top bin 41 for storage. When there is no raw material on the feeding trolley 44, the feeding trolley 44 travels along the transportation track to the position of the kiln top bin 41, and the discharge valve of the kiln top bin 41 is opened to perform the feeding operation of the feeding trolley 44. When the shaft kiln needs to perform the feeding operation, the feeding trolley 44 travels to the feeding position, and the sealing device 1 is closed to perform the feeding operation into the kiln.

[0056] As a preferred embodiment of the utility model, a raw material discharge valve 411 is arranged at the bottom of the kiln top bin 41; a radar level gauge is arranged on the kiln top bin; the radar level gauge is connected to a main control computer device; and the main control computer device is in signal connection with the raw material discharge valve 411.

[0057] Specifically, by installing a radar level gauge on the kiln top bin 41, the level of the limestone raw material inside can be tracked in real time, and the monitored level data is fed back to the main control computer device. The main control computer device includes a data processing module and an execution control module. The data processing module analyzes the received level data to generate a level prompt message, indicating whether to add or stop adding materials to the kiln top bin 41, thus avoiding overfilling and underfilling. When it is necessary to add materials to the feeding truck 44, the feeding information can be input into the execution control module to control the opening of the raw material discharge valve 411. And when the information generated by the data processing module indicates that the level in the kiln top bin 41 is insufficient, the raw material discharge valve 411 is automatically controlled to close through the execution control module using a set program, thereby realizing automatic control of the material distribution. Among them, the main control computer device is arranged in the control room on the ground.

[0058] As a preferred embodiment of the present utility model, a discharge valve 163 is provided at the discharge port of the cooling section 16, and the discharge valve 163 is in signal connection with the main control computer device.

[0059] By the signal connection between the discharge valve 163 and the main control computer device, the automatic control of the discharge process can be realized by setting a cooling time program.

[0060] As a preferred embodiment of the present utility model, a thermocouple is provided in the calcination section 13; the thermocouple is connected to the main control computer device; the main control computer device is in signal connection with a switch provided on the gas pipeline 24.

[0061] Specifically, by providing a thermocouple in the calcination section 13, the temperature data inside the calcination section 13 can be collected in real time, and the opening and closing of the switch of the gas pipeline 24 can be automatically controlled through the program set in the main control computer device, so as to ensure that the wall temperature during the decomposition of limestone is always at 1150±30°C, approximately in a "constant temperature" state. In this temperature environment, heat is transferred to the limestone in the form of radiation and convection, and the limestone begins to absorb heat and decompose until it is completely decomposed by heat absorption, releasing carbon dioxide and obtaining calcium oxide (i.e., the finished lime).

[0062] As a preferred embodiment of the present utility model, it further includes a waste heat recycling system; among them, the waste heat recycling system includes a preheated air conveying pipeline 51 connected to the high-temperature cooling air outlet of the cooling section 16 and a high-temperature fan 52 provided on the preheated air conveying pipeline 51; the air outlet of the preheated air conveying pipeline 51 is connected to the preheated air inlet on the preheating section 11.

[0063] Specifically, after the calcium oxide decomposed from limestone (calcium carbonate) by endothermic decomposition, i.e., the finished lime, enters the cooling section 16, it is cooled by the cooling section 16. After the gas-solid heat exchange is completed, the hot waste gas is pressurized by the high-temperature blower and blown into the preheating section 11 to preheat the limestone. After the temperature of the finished lime is cooled to below 110°C, it is discharged to the finished product belt conveyor 17 through the discharge valve 163 to complete the ash discharging operation.

[0064] As a preferred embodiment of the present invention, a cooling fan 161 is connected to the cooling air inlet of the cooling section 16 for cooling the finished lime in the cooling section 16.

[0065] As a preferred embodiment of the present invention, an exhaust gas treatment system is further included. Among them, the exhaust gas treatment system includes an exhaust gas main pipe 61, a second dust removal device 62 connected to the exhaust gas outlet of the exhaust gas main pipe 61, an exhaust gas fan 63 connected to the second dust removal device 62, and a chimney 64 connected to the exhaust gas fan 63. A third reversing valve 65 is provided at the exhaust gas collection end of the exhaust gas main pipe 61. Two ports of the third reversing valve 65 are respectively connected to the exhaust gas outlets of the A-side regenerative burner 21 and the B-side regenerative burner 22. The preheating exhaust gas outlet of the preheating section 11 is connected to the exhaust gas main pipe 61.

[0066] Among them, the preheating exhaust gas outlet of the preheating section 11 is connected to the exhaust gas main pipe 61 through a preheating exhaust gas pipeline 112.

[0067] As a preferred embodiment of the present invention, the first dust removal device 32 is a bag filter; and / or, the second dust removal device 62 is a bag filter; and / or, the waste heat recovery device 31 is a waste heat boiler; and / or, the air supply device 23 is a combustion-supporting fan.

[0068] Among them, the steam drum 311 of the waste heat boiler is connected to the plant pipe network 312.

[0069] As a preferred embodiment of the present invention, a first air cap 111 is provided at the preheating air inlet; and / or, a second air cap 162 is provided at the cooling air inlet.

[0070] Using the lime calcination device provided by the present invention to calcine limestone and recover the carbon dioxide generated by the decomposition of limestone calcination includes the following steps:

[0071] Step S1: Keep the first sealing device 12 in a closed state, and add limestone raw materials into the preheating section 11 of the shaft kiln through the feeding port;

[0072] Step S2: Send preheating air into the preheating section 11 through the preheating air inlet to make the temperature of the limestone raw materials in the preheating section 11 reach the preset temperature;

[0073] Step S3: Keep the first sealing device 12 in the open state and the second sealing device 14 in the closed state, and feed the limestone raw materials that have reached the preset temperature in the preheating section 11 into the calcination section 13 from the first feeding port.

[0074] Step S4: Keep both the first sealing device 12 and the second sealing device 14 in the closed state, and make the A-side regenerative burner 21 and the B-side regenerative burner 22 work alternately. The high-temperature flue gas generated in the combustion chamber 15 transfers heat to the inside of the calcination section 13 through the side walls of the furnace wall of the calcination section 13 in the forms of thermal radiation and thermal convection, so that the wall temperature inside the calcination section 13 reaches and stabilizes at 1150 ± 30 °C, and the limestone raw materials inside the calcination section 13 are thermally decomposed.

[0075] Step S5: The thermal decomposition of the limestone raw materials in the calcination section 13 continues until the preset time. Keep the second sealing device 14 in the open state. The finished lime produced by the thermal decomposition of the limestone raw materials in the calcination section 13 enters the cooling section 16 for cooling and then is discharged from the discharge port. The carbon dioxide generated in the calcination section 13 is successively subjected to waste heat recovery through the waste heat recovery device 31, dust removal through the first dust removal device 32, and then enters the carbon dioxide recovery process system 33 for carbon dioxide process treatment to obtain high-purity carbon dioxide products.

[0076] Among them, the preset temperature is preferably 250 °C.

[0077] The preset time for the continuous thermal decomposition of the limestone raw materials in the calcination section 13 can be set through experiments or actual needs, and the present utility model does not make special limitations thereon.

[0078] It can be seen from the above specific embodiments that the lime calcination device provided by the present utility model separates the preheating, calcination, and cooling of the limestone raw materials through the structural design of the shaft kiln and uses the first sealing device and the second sealing device to ensure the separation of the waste gas generated by preheating and cooling from the thermal decomposition of calcium carbonate, thereby obtaining high-purity carbon dioxide; combined with the internal and external structural arrangements of the calcination section and the combustion chamber, the limestone is thermally decomposed into CaO and CO 2 , further ensuring the high purity of CaO and CO 2 ; the concentration of the obtained carbon dioxide gas is as high as 99% (dry basis), and the value of the high-value-added carbon dioxide product is much higher than the value of the lime itself; the internal and external arrangements of the heating combustion system can also reduce the erosion of the high-temperature gas flow on the refractory materials inside the calcination section and can extend the service life of the refractory materials; and by using the shaft kiln in the present utility model to calcine limestone, the limestone with a particle size of 5 mm - 20 mm abandoned in the limestone mine can be reused, effectively improving the resource utilization rate.

[0079] Through the structural design of the heating combustion system, the reversing valve can be used to make the regenerative burner on side A and the regenerative burner on side B work alternately. When the regenerative burner on one side is working, the regenerative burner on the opposite side stores heat, forming a cyclic operation in the heating process. While making full use of the combustion waste heat, it is also convenient to control the thermal decomposition temperature in the calcination section to be in an approximately "constant" state, effectively preventing the occurrence of the phenomenon of "overburning and underburning". The overburning rate of the calcium oxide product is ≤ 1%.

[0080] Through the design of the carbon dioxide recovery system, the high-temperature carbon dioxide gas (about 1000 °C) generated in the calcination section is first subjected to waste heat recovery using a waste heat recovery device and then dust removal through a first dust removal device. The clean and low-temperature carbon dioxide gas is purified, cooled, and pressurized through a carbon dioxide recovery process system to be transformed into liquid carbon dioxide and then recovered and utilized in cans, further making full use of the waste heat generated by the carbon dioxide gas, with remarkable energy-saving effects. The utility model can achieve the maximum utilization of resources.

[0081] As described above by way of example with reference to the drawings, the lime calcination device proposed according to the present utility model has been described. However, those skilled in the art should understand that various improvements can be made to the above-mentioned lime calcination device proposed by the present utility model without departing from the content of the present utility model. Therefore, the protection scope of the present utility model should be determined by the content of the appended claims.

Claims

1. A lime calcining device, characterized in that: It includes vertical kiln, heating and combustion system and carbon dioxide recovery system; among which, The vertical kiln comprises a preheating section, a first sealing device arranged at the lower end of the preheating section, a calcining section arranged at the lower end of the first sealing device, a second sealing device arranged at the lower end of the calcining section, a combustion chamber surrounded by the outside of the calcining section, and a cooling section arranged at the lower end of the second sealing device; A feeding port is provided at the top of the preheating section; a preheating air inlet and a preheating exhaust gas outlet are provided on the preheating section; a carbon dioxide outlet is provided on the calcining section; a cooling air inlet and a preheating air outlet are provided on the cooling section, and a discharge port is provided at the bottom of the cooling section; a finished product belt conveyor is provided below the discharge port; When the first sealing device is in an open state, a first material discharge port is formed between the preheating section and the calcining section; when the first sealing device is in a closed state, the preheating section and the calcining section are sealed and separated by the first sealing device; When the second sealing device is in an open state, a second feed opening is formed between the calcining section and the cooling section; when the second sealing device is in a closed state, the calcining section and the cooling section are sealed and separated by the second sealing device; The heating and combustion system comprises an A-side regenerative burner and a B-side regenerative burner respectively arranged on both sides of the combustion chamber, an air supply device and a gas pipeline; a first reversing valve is arranged on the air main pipe of the air supply device; a second reversing valve is arranged at the outlet of the gas pipeline; the air inlets of the A-side regenerative burner and the B-side regenerative burner are respectively connected to the two ports of the first reversing valve through the air pipeline; the gas inlets of the A-side regenerative burner and the B-side regenerative burner are respectively connected to the two ports of the second reversing valve through the gas branch pipeline; The carbon dioxide recovery system includes a waste heat recovery device connected to the carbon dioxide outlet through a pipeline, a first dust removal device connected to the waste heat recovery device, and a carbon dioxide recovery process system connected to the first dust removal device.

2. The lime calcining device according to claim 1, characterized in that: Also includes a cloth system; wherein, The material distribution system comprises: a kiln top material bin arranged above the preheating section, an inclined bridge arranged on one side of the kiln top material bin, and a material cart arranged on the inclined bridge and capable of moving along the inclined bridge; One end of the inclined bridge is arranged on the ground, and the other end is arranged above the kiln top silo.

3. The lime calcining device according to claim 2, characterized in that: A feeding position is provided on one side of the feeding port of the preheating section; A transport track is arranged on the top of the preheating section; the transport track is arranged between the feeding position and the kiln top silo; and a feeding vehicle is arranged on the transport track.

4. The lime calcining device according to claim 2, characterized in that: A raw material discharge valve is provided at the bottom of the kiln top silo; A radar level meter is arranged on the kiln top silo; The radar level meter is connected to a main control computer device; The main control computer device is connected to the raw material discharge valve signal.

5. The lime calcining device according to claim 4, characterized in that: A thermocouple is provided in the calcining section; The thermocouple is connected to the main control computer device; The main control computer device is connected to the switch signal arranged on the gas pipeline.

6. The lime calcining device according to claim 1, characterized in that: It also includes a waste heat recycling system; The waste heat recycling system comprises a preheated air delivery duct connected to the high-temperature cooling air outlet of the cooling section and a high-temperature fan arranged on the preheated air delivery duct; The air outlet of the preheated air delivery duct is connected to the preheated air inlet on the preheating section.

7. The lime calcining device according to claim 1, characterized in that: A cooling fan is connected to the cooling air inlet of the cooling section.

8. The lime calcining device according to claim 1, characterized in that: Also includes an exhaust gas treatment system; wherein, The exhaust gas treatment system comprises an exhaust gas main pipe, a second dust removal device connected to the exhaust gas outlet of the exhaust gas main pipe, an exhaust gas fan connected to the second dust removal device, and a chimney connected to the exhaust gas fan; A third reversing valve is provided at the exhaust gas collecting end of the exhaust gas main pipe; The two ports of the third reversing valve are respectively connected to the exhaust gas outlets of the A-side regenerative burner and the B-side regenerative burner; The preheating exhaust gas outlet of the preheating section is connected to the exhaust gas main pipe.

9. The lime calcining device according to claim 8, characterized in that: The first dust removal device is a bag dust collector; and / or, The second dust removal device is a bag dust collector; and / or, The waste heat recovery device is a waste heat boiler; and / or, The air supply device is a combustion-supporting fan.

10. The lime calcining device according to claim 1, characterized in that: A first hood is provided at the preheating air inlet; and / or, A second hood is provided at the cooling air inlet.

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