Limestone calcining equipment and process

Abstract

The invention relates to the technical field of limestone calcining, in particular to limestone calcining equipment and a limestone calcining process, comprising a feeding system, a kiln, a discharging system and a flue gas system; the feeding system is located above the kiln and used for conveying limestone and fire coal mixed materials to the kiln, and the kiln is used for conducting high-temperature calcination on the mixed materials to form quick lime. The discharging system is located at the bottom of the kiln and effectively discharges quick lime out of the kiln. And the flue gas system is connected with the kiln and is used for discharging sulfur-containing and nitrogen-containing gas generated in the kiln. Mixed materials can be conveyed for three or more kilns through the belt conveyor, the belt conveyor runs among the three or more kilns, production lines of a feeding system are reduced while the yield and quality are guaranteed, and the production efficiency is improved; 6-8 material guide grooves are formed in the outer wall of the conical head of the disc ash discharging machine of the discharging system, so that uniform descending of a material column can be realized, the continuity and the stability of production are ensured, and meanwhile, the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of limestone calcining, in particular to limestone calcining equipment and process. Background Art

[0002] The main component of limestone is calcium carbonate. Limestone is a raw material used in building materials and industry. Limestone with a high content of calcium carbonate (CaCO3) is obtained by calcining it at high temperature in a ventilated lime kiln. The main component of quicklime is calcium oxide (CaO), which is generally in block form. It is white when pure and light gray or light yellow when it contains impurities. Quicklime absorbs moisture or adds water to become slaked lime. The main component of slaked lime is calcium hydroxide (Ca(OH)2). Slaked lime is prepared into lime slurry, lime paste, etc., which are used as coating materials and brick and tile adhesives.

[0003] Limestone enters the lime kiln through the feeding system for high-temperature calcination. The finished product produced by calcination is discharged from the kiln through the ash discharger. The flue gas produced by calcination is discharged from the kiln through the flue gas duct to the flue gas treatment system. The entire calcination process is crucial to the calcination efficiency of limestone. In the prior art, the patent number "CN110526598A" and the name "A system and process for calcining active lime" discloses an active lime calcining system and process, including a raw material bin, a calcination powder preparation subsystem, an intermediate bin, a feeding subsystem, a calcination subsystem, a finished product bin and an exhaust gas emission subsystem; the feeding subsystem in the system is used to feed the calcination subsystem, and the product produced after calcination is Raw lime is transported to the finished product bin. Each feeding subsystem in the patent manages a calcining subsystem, which has low efficiency during feeding and requires multiple feeding subsystems to work. The temperature in the lime kiln directly affects the quality and output of lime. In order to ensure the quality and stability of lime, the temperature and gas flow in the kiln need to be monitored in real time. The patent lacks a module for monitoring the temperature and gas flow in the kiln. In the prior art, a disc ash discharger is generally used to discharge lime from the kiln. The cone head surface of the disc ash discharger is designed as a continuous curved surface. When the material column descends, the material column may descend unevenly, and production may be interrupted, affecting the continuity and stability of production. Summary of the invention

[0004] The object of the present invention is to provide a limestone calcining equipment and process, which can complete the limestone calcining process with high efficiency and high quality, while ensuring the output and quality during the feeding process, reducing the production line and improving the production efficiency; during the discharging process, the disc ash discharger is optimized to improve the ash discharge efficiency, and at the same time, an air supply monitoring module is added to monitor the production quality in real time.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a limestone calcining equipment, comprising a feeding system, a kiln, a discharging system and a flue gas system; the feeding system is located above the kiln, and is used to convey a mixture of limestone and coal to the kiln, and the kiln is used to calcine the mixture into quicklime at high temperature; the discharging system is located at the bottom of the kiln, and effectively discharges the quicklime out of the kiln; the flue gas system is connected to the kiln, and the flue gas system is used to discharge and treat the sulfur-containing and nitrogen-containing gases generated inside the kiln.

[0006] The feeding system includes a belt conveyor, a plough discharger, a first lower hopper, a first receiving hopper, a kiln gate, a second receiving hopper and a rotary distributor; the belt conveyor can convey mixed materials for three or more kilns, the belt conveyor runs between the kilns, a head wheel is arranged at one end of the belt conveyor, a tail wheel is arranged at the other end, and a redirecting wheel for guiding the belt conveyor to change direction smoothly is arranged below the head wheel; the plough discharger is located above the belt conveyor and arranged at the feed port of the kiln, the plough discharger executes the signal given by the central control and discharges the raw materials into the corresponding kilns respectively; the first lower hopper is connected to the left side of the plough discharger, the direction of the head wheel is set to the left side, a first receiving hopper is arranged below the first lower hopper, a kiln gate for controlling the in and out and flow of mixed materials is arranged below the first receiving hopper, a second receiving hopper is arranged below the kiln gate, and a rotary distributor is arranged below the second receiving hopper.

[0007] Preferably, the kiln is cylindrical in shape, and the ratio of the inner diameter to the height of the kiln is set in the range of 5.5-6. An upper kiln door is provided at the upper end of the kiln, and a lower kiln door is provided at the lower end of the kiln; the kiln has four layers of material, which are a working layer, a second ring, a third ring and an outer shell from the inside to the outside, the working layer is made of secondary high-alumina bricks, the second ring is made of clay refractory bricks, the third ring is made of lightweight insulation bricks, and the outer shell is made of steel; aluminum silicate insulation cotton is provided on the inner wall of the outer shell, and insulation filler is filled between the lightweight insulation bricks and the aluminum silicate insulation cotton, and the kiln is provided with a preheating zone, a calcination zone and a cooling zone from top to bottom.

[0008] Preferably, the discharging system includes a second lower hopper, a disc ash discharger is arranged below the second lower hopper, a two-stage valve box for discharging materials is arranged below the disc ash discharger, the disc ash discharger includes a disc, a cone head, a scraper and a driving device, the cone head is located above the disc, the scraper is located above the disc and is fixedly connected to the second lower hopper through a scraper support, and the driving device is used to drive the disc to rotate.

[0009] Preferably, 6-8 material guide grooves are evenly arranged on the outer wall of the cone head, and the material of the material guide grooves is steel.

[0010] Preferably, the flue gas system includes a Roots blower for supplying air and oxygen, the flue gas system includes a Roots blower for supplying air and oxygen, the Roots blower is arranged on the left side of the kiln, the Roots blower is connected to the kiln through an air supply duct, the flue gas system also includes a dust removal duct, the dust removal duct is connected to the interior of the kiln, and a dust removal hood is arranged above the dust removal duct.

[0011] Preferably, the size of the working layer secondary high-alumina brick is: width 110mm / width 150mm*thickness 75mm*length 345mm, the size of the two-ring clay refractory brick is: width 150mm / width 135mm*thickness 75mm*length 230mm, and the size of the three-ring lightweight insulation brick is: width 150mm / width 135mm*thickness 75mm*length 230mm.

[0012] Preferably, the nodes of the cooling zone and the calcining zone are provided with a buffer zone for centralized air and oxygen supply, and the height of the buffer zone is set to 3-5 meters.

[0013] Preferably, the discharging system also includes an air supply monitoring module, which includes a gas flow detector, an oxygen monitor and a thermocouple. The gas flow detector is arranged inside the air supply duct, and the oxygen detector and the thermocouple are arranged inside the dust removal duct.

[0014] A process for limestone calcining equipment comprises the following steps:

[0015] S1: The mixture of limestone and coal is unloaded onto the belt conveyor, and the plough-type unloader executes the signal given by the central control to unload the raw materials into the corresponding first lower hoppers;

[0016] S2: The first lower hopper discharges the mixed material into the first receiving hopper, and the mixed material in the first receiving hopper is discharged into the second receiving hopper by controlling the switch of the furnace gate, and the mixed material in the second receiving hopper is evenly distributed into the furnace through the rotating distributor;

[0017] S3: After the mixed material is preheated in the preheating zone, it is calcined in the calcining zone. During the calcining process, the Roots blower is used to supply air and oxygen to the kiln. Finally, it is cooled in the cooling zone to finally generate finished quicklime.

[0018] S4: The product quicklime is discharged from the disc ash discharger at the bottom of the kiln.

[0019] Preferably, the rotating speed of the rotary distributor is 7r / min, the distribution diameter is 3.4-4.0, and the distribution capacity is 500m 3 / d; the flow rate of the Roots blower is 264m 3 / min, the boost pressure is 101.3Kpa; the ash discharge capacity of the disc ash discharger is 84t / h, the speed is 2-3m 3 / min, the preheating temperature is set to 550-800°C, the calcination temperature is set to 1000-1300°C, the calcination time is 4-6 hours, and the cooling temperature is set to 40-60°C.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention can convey mixed materials to three or more kilns through a belt conveyor, and the belt conveyor runs between the three or more kilns; the plough type unloader is located above the belt conveyor and is arranged at the feed port of the kiln. The plough type unloader executes the signal given by the central control to unload the mixed materials into the corresponding kilns respectively, thereby reducing the production line of the feeding system while ensuring the output and quality, and improving the production efficiency.

[0022] 2. In the present invention, 6-8 material guide grooves are arranged on the outer wall of the cone head of the disc ash discharger, which can realize the uniform descent of the material column. The height of the material column in the kiln is always kept consistent, avoiding production interruption or equipment damage caused by uneven descent of the material column, thereby ensuring the continuity and stability of production and improving production efficiency.

[0023] 3. The present invention utilizes the air supply monitoring module to carry out real-time monitoring of the gas flow rate, flue gas temperature and oxygen content, and can timely adjust the air supply and oxygen supply flow rate of the Roots blower to ensure the stability and efficiency of the combustion process and improve the quality and efficiency of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the top view of the structure of the present invention;

[0026] Figure 3 For the present invention Figure 1 A schematic diagram of the enlarged structure at B;

[0027] Figure 4 For the present invention Figure 1 A schematic diagram of the enlarged structure at C;

[0028] Figure 5 For the present invention Figure 1 A schematic diagram of the structure at D of FIG.

[0029] Figure 6 It is a schematic diagram of the kiln structure of the present invention;

[0030] Figure 7 It is a schematic diagram of the AA cross-sectional structure of the present invention;

[0031] Figure 8 It is a schematic diagram of the structure of the discharging system of the present invention;

[0032] Fig. 9 For the present invention Figure 8 A schematic diagram of the structure at E of FIG.

[0033] Fig.10 It is a structural diagram of the workflow of the present invention.

[0034] In the figure: 1. kiln; 2. belt conveyor; 3. plow discharger; 4. first lower hopper; 5. first receiving hopper; 6. kiln gate; 7. second receiving hopper; 8. rotary distributor; 9. head wheel; 10. tail wheel; 11. redirecting wheel; 12. upper kiln door; 13. lower kiln door; 14. working layer; 15. second ring; 16. third ring; 17. outer shell; 18. preheating zone; 19. calcining zone; 20. cooling zone; 21. buffer zone; 22. second lower hopper; 23. two-stage valve box; 24. cone head; 25. disc; 26. scraper; 27. scraper support; 28. material guide trough; 29. ​​Roots blower; 30. air supply duct; 31. dust removal duct; 32. dust removal hood; 33. gas flow detector. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1-10 A limestone calcining equipment comprises a feeding system, a kiln 1, a discharging system and a flue gas system; the feeding system is located above the kiln 1, and is used to transport a mixture of limestone and coal to the kiln 1, and the kiln 1 is used to calcine the limestone into quicklime at high temperature; the discharging system is located at the bottom of the kiln 1, and is used to effectively discharge the quicklime from the kiln 1; the flue gas system is connected to the kiln 1, and the flue gas system is used to discharge and treat the sulfur-containing and nitrogen-containing gases generated inside the kiln 1.

[0037] The feeding system comprises a belt conveyor 2, a plow discharger 3, a first lower hopper 4, a first receiving hopper 5, a kiln gate 6, a second receiving hopper 7 and a rotary distributor 8; the belt conveyor 2 can convey mixed materials for three or more kilns 1. In this embodiment, the number of kilns 1 is set to three, and the belt conveyor 2 runs between the three kilns 1. A head wheel 9 is provided at one end of the belt conveyor 2, and the head wheel 9 is used to drive the belt to rotate. A tail wheel 10 is provided at the other end. A redirecting wheel 11 is provided below the head wheel 9 to guide the belt conveyor 2 to change direction smoothly; The plow discharger 3 is located above the belt conveyor 2 and is arranged at the feed port of the kiln 1. The plow discharger 3 executes the signal given by the central control to discharge the raw materials into the corresponding kiln 1 respectively; the left side of the plow discharger 3 is connected to the first lower hopper 4. In this embodiment, the plow discharger 3 discharges the raw materials into the first lower hopper 4, and the first lower hopper 4 realizes the storage and stacking of the raw materials. A first receiving hopper 5 is arranged below the first lower hopper 4. The first receiving hopper 5 receives the feed from the first lower hopper 4. The first receiving hopper 5 is a conical hopper. Such a setting is helpful The first receiving hopper 5 is provided with a kiln gate 6 for controlling the mixing in and out and the flow rate. The pressure inside the kiln 1 can be controlled by opening or closing the kiln gate 6. When the kiln 1 needs to be exhausted, the kiln gate 6 will be opened to allow the gas to be discharged smoothly. When it is necessary to maintain a certain pressure inside the kiln 1, the kiln gate 6 will be closed to prevent external gas from entering. The kiln gate 6 can ensure a stable environment inside the kiln 1 and ensure the stability of production. A second receiving hopper 7 is provided, and the second receiving hopper 7 has a cone on the top and a cylinder on the bottom. Such a configuration can not only receive the feeding from the first receiving hopper 5, but also prevent the splashing of materials during the feeding process. A rotary distributor 8 is provided below the second receiving hopper 7. The rotary distributor 8 can fully mix different types of raw materials through rotating motion. The rotary distributor 8 can also ensure the uniform distribution of materials in the entire kiln 1 by adjusting the rotation speed and angle, etc., to avoid raw material accumulation, ensure that the raw materials are fully burned in the kiln 1, and improve product quality.

[0038] The kiln 1 is in the shape of a cylinder. An upper kiln door 12 is provided at the upper end of the kiln 1. The upper kiln door 12 is used to observe the situation in the kiln and to facilitate the maintenance of equipment. A lower kiln door 13 is provided at the lower end of the kiln 1. The lower kiln door 13 is used for ignition. The kiln 1 has four layers of material, which are a working layer 14, a second ring 15, a third ring 16 and an outer shell 17 from the inside to the outside. The working layer 14 is made of secondary high-alumina bricks with the following model: alumina content ≥65, softness>1500℃, compressive strength>50, body density ≥2.4, and the dimensions are: width 110mm / width 150mm*thickness 75mm*length 345mm; the second ring 15 is made of clay refractory bricks with the following model: alumina content 32-35, softness 1400℃, compressive strength 30, body density ≥2.4, and the dimensions are: width 110mm / width 150mm*thickness 75mm*length 345mm; the second ring 15 is made of clay refractory bricks with the following model: alumina content 32-35, softness 1400℃, compressive strength 30, body density Density 2.1; size: width 150mm / width 135mm*thickness 75mm*length 230mm; the third ring 16 adopts lightweight insulation bricks, with the size of width 150mm / width 135mm*thickness 75mm*length 230mm; the working layer 14 and the second ring 15 adopt bricks of different thicknesses, which avoids the problem of fire and temperature transmission caused by parallel reunion of bricks of the same thickness, and at the same time avoids the waste of heat energy and improves the insulation effect. The use of thicker bricks in the working layer 14 and the second ring 15 also increases the strength and prolongs the service life; the inner wall of the steel shell 17 is provided with aluminum silicate insulation cotton, and the lightweight insulation bricks and the aluminum silicate insulation cotton are filled with insulation fillers to ensure that the refractory insulation effect is achieved in accordance with the production requirements of environmentally friendly vertical kilns.

[0039] The kiln 1 is provided with a preheating zone 18, a calcining zone 19 and a cooling zone 20 from top to bottom respectively; in the preheating zone 18, the material gradually heats up and removes surface moisture by contacting with the inner wall of the kiln 1 and the hot air in the kiln 1; in the calcining zone 19, the raw material is subjected to high temperature and gradually undergoes a transformation process from limestone to quicklime; in the cooling zone 20, air cooling is used to cool the quicklime; it is worth noting that a buffer zone 21 for centralized air and oxygen supply is provided at the node of the cooling zone 20 and the calcining zone 19, and the height of the buffer zone 21 is set to 3-5 meters. With this arrangement, the coal that is not fully burned in the calcining zone 19 is quickly burned in this area, which solves the problems of downward movement of the calcining zone 19, biased fire, and insufficient cooling of the finished ash during the production process of the kiln 1, thereby improving the quality and efficiency of production.

[0040] The ratio range of the inner diameter and height of the kiln 1 is set to 5.5-6. The unreasonable design of the ratio of the inner diameter and height of the kiln 1 will cause the top temperature in the kiln 1 to be often too high during preheating; during calcination, the calcination zone 19 is elongated, resulting in the reduction of the preheating zone 18 and the cooling zone 20, which makes it difficult to control the top temperature and cause overburning; during cooling, the cooling zone 20 is shortened, resulting in insufficient cooling time, which makes it difficult to control the overburning and ash discharge temperature; the preheating zone 18, calcining zone 19 and cooling zone 20 are unstable, resulting in the production output not meeting the standard and the production quality is difficult to guarantee. In this embodiment, the inner diameter of the kiln 1 is set to 4.28 meters, and the ratio range of the inner diameter and height of the kiln 1 is set to 5.5-6, which not only increases the volume of the kiln 1, but also avoids the problems of difficult control of the top temperature, raw overburning and ash discharge temperature in the preheating zone 18, calcining zone 19 and cooling zone 20.

[0041] The discharging system includes a second lower hopper 22, which is used to receive the finished product output. A disc ash discharging machine is arranged below the second lower hopper 22. The disc ash discharging machine is evenly distributed on the circumference of the kiln 1 to ensure that the quicklime in the kiln 1 is evenly discharged from multiple symmetrical directions, thereby avoiding the material surface deflection phenomenon. A two-stage valve box 23 for discharging is arranged below the disc ash discharging machine. The disc ash discharging machine includes a disc 25, a cone head 24, a scraper 26 and a driving device. The cone head 24 is located on the upper side of the disc 25. The scraper 26 is located above the disc 25 and is fixedly connected to the second lower hopper 22 through the scraper support 27. The driving device is used to drive the disc 25 to rotate. It is worth noting that 6-8 guide grooves 28 are evenly arranged on the outer wall of the cone head 24. In this embodiment, the number of guide grooves 28 is set to 8. The material of the guide groove 28 is steel. Such a setting ensures that the material column in the kiln 1 is uniformly lowered during ash discharge, ensures the continuity and stability of production, and improves the production efficiency. When the discharging system is working, the finished product falls from the second lower hopper 22 into the cone head 24, and the finished product falls evenly and smoothly onto the disc 25 through the guide groove 28. The disc 25 is driven to rotate by the driving device. After the finished lime falling from the upper part of the cone head 24 falls on the rotating disc 25, the finished product is evenly scattered on the disc 25 under the action of the scraper 26, ensuring that the material is evenly distributed on the disc 25, and then discharged from the kiln 1 through the two-stage valve box 23.

[0042] The flue gas system includes a Roots blower 29 for supplying air and oxygen. The Roots blower 29 can provide a stable airflow and compressed gas to ensure the combustion efficiency and production efficiency in the kiln 1. The Roots blower 29 is arranged on the left side of the kiln 1 and is connected to the kiln 1 through an air supply duct 30. The flue gas system also includes a dust removal duct 31. The dust removal duct 31 is connected to the inside of the kiln 1 and is used to discharge sulfur-containing and nitrogen-containing gases. A dust removal hood 32 is arranged above the dust removal duct 31 for flue gas discharge and cooling and heat dissipation.

[0043] The flue gas system also includes an air supply monitoring module, which includes a gas flow detector 33, an oxygen monitor and a thermocouple. The gas flow detector 33 is arranged inside the air supply duct 30, and can accurately measure the flow rate of air and oxygen supplied by the Roots blower 29, ensure the stable supply of gas and improve the stability and combustion efficiency of combustion; the oxygen detector and the thermocouple are arranged inside the dust removal duct 31, and the oxygen detector is used to measure the oxygen content in the kiln 1, and can accurately judge the combustion condition and flue gas emission condition of the kiln 1, and timely adjust the air supply flow rate of the Roots blower 29, so as to optimize the combustion process, improve the combustion efficiency and reduce the emission of harmful gases. The thermocouple is used to monitor and control the temperature inside the kiln 1 to ensure the stability of the production process and the quality of the product.

[0044] A process for limestone calcining equipment comprises the following steps:

[0045] S1: The mixture of limestone and coal is unloaded to the belt conveyor 2, and the plough discharger 3 executes the signal given by the central control to discharge the raw materials into the corresponding first lower hopper 4;

[0046] S2: The first lower hopper 4 discharges the mixed material into the first receiving hopper 5, and the mixed material in the first receiving hopper 5 is discharged into the second receiving hopper 7 by controlling the switch of the kiln gate 6. The mixed material in the second receiving hopper 7 is evenly distributed into the kiln 1 through the rotating distributor 8;

[0047] S3: After the mixed material is preheated in the preheating zone 18, it is calcined in the calcining zone 19. During the calcining process, the Roots blower 29 is used to supply air and oxygen to the kiln 1. Finally, it is cooled in the cooling zone 20 to finally generate finished quicklime.

[0048] S4: Discharging the product quicklime from the disc ash discharger at the bottom of the kiln 1.

[0049] The speed of the rotary distributor 8 is 7r / min, the diameter of the material is 3.4-4.0, and the material capacity is 500m 3 / d; the flow rate of the Roots blower 29 is 264m 3 / min, the boost pressure is 101.3Kpa; the ash discharge capacity of the disc ash discharger is 84t / h, the speed is 2-3m 3 / min.

[0050] When the present invention is working, the mixed material is evenly stepped into the kiln 1 through the rotating distributor 8, and the mixed material slowly moves downward by its own weight to overcome the buoyancy of the air flow, and successively passes through the preheating zone 18, the calcining zone 19 and the cooling zone 20. During the descent process, the material exchanges heat with the hot coal gas, and is accompanied by the decomposition of lime and the growth process of quicklime grains. During the whole process, the preheating temperature in the kiln 1 is set to 550-800°C, the combustion temperature is controlled at 1000-1300°C, and it is fully calcined for 4-6 hours. After the calcination is completed, the finished product is cooled to 40-60°C by the Roots blower 29 using air, and then discharged to the belt conveyor through the disc ash discharger and the two-stage valve box 23.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A limestone calcining equipment, characterized in that: The invention comprises a feeding system, a kiln (1), a discharging system and a flue gas system; the feeding system is located above the kiln (1) and is used to convey a mixture of limestone and coal to the kiln (1); the kiln (1) is used to calcine the mixture at high temperature into quicklime; the discharging system is located at the bottom of the kiln (1) and is used to effectively discharge the finished quicklime from the kiln (1); the flue gas system is connected to the kiln (1) and is used to discharge sulfur-containing and nitrogen-containing gases generated inside the kiln (1); The feeding system comprises a belt conveyor (2), a plough discharger (3), a first lower hopper (4), a first receiving hopper (5), a kiln gate (6), a second receiving hopper (7) and a rotary distributor (8); the belt conveyor (2) can convey mixed materials for three or more kilns (1), the belt conveyor (2) runs between the kilns (1), a head wheel (9) is arranged at one end of the belt conveyor (2), and a tail wheel (10) is arranged at the other end, and a redirecting wheel (11) is arranged below the head wheel (9) to guide the belt conveyor (2) to change direction smoothly; the plough discharger (3 ) is located above the belt conveyor (2) and is arranged at the feed port of the kiln (1); the plow type discharger (3) executes the signal given by the central control to discharge the raw materials into the corresponding kiln (1); the left side of the plow type discharger (3) is connected to a first lower hopper (4); a first receiving hopper (5) is arranged below the first lower hopper (4); a furnace gate (6) for controlling the mixing in and out and flow rate is arranged below the first receiving hopper (5); a second receiving hopper (7) is arranged below the furnace gate (6); and a rotary distributor (8) is arranged below the second receiving hopper (7).

2. A limestone calcining equipment according to claim 1, characterized in that: The kiln (1) is cylindrical in shape, the ratio of the inner diameter to the height of the kiln (1) is set in the range of 5.5-6, an upper kiln door (12) is arranged at the upper end of the kiln (1), and a lower kiln door (13) is arranged at the lower end of the kiln (1); the material of the kiln (1) has four layers, which are respectively a working layer (14), a second ring (15), a third ring (16) and an outer shell (17) from the inside to the outside, and the material used for the working layer (14) is a second-grade The material of the second ring (15) is clay refractory brick, the material of the third ring (16) is lightweight insulation brick, and the material of the outer shell (17) is steel; the inner wall of the outer shell (17) is provided with aluminum silicate insulation cotton, and the space between the third ring (16) and the aluminum silicate insulation cotton is filled with heat-insulating filler; the kiln (1) is provided with a preheating zone (18), a calcining zone (19) and a cooling zone (20) from top to bottom.

3. A limestone calcining equipment according to claim 1, characterized in that: The discharging system comprises a second lower hopper (22), a disc ash discharging machine is arranged below the second lower hopper (22), a two-stage valve box (23) for discharging is arranged below the disc ash discharging machine, the disc ash discharging machine comprises a cone head (24), a disc (25), a scraper (26) and a driving device, the cone head (24) is located above the disc (25), the scraper (26) is located above the disc (25) and is fixedly connected to the second lower hopper (22) through a scraper support (27), and the driving device is used to drive the disc (25) to rotate.

4. A limestone calcining equipment according to claim 4, characterized in that: 6 to 8 material guide grooves (28) are evenly arranged on the outer wall of the cone head (23), and the material of the material guide grooves (28) is steel.

5. A limestone calcining equipment according to claim 1, characterized in that: The flue gas system comprises a Roots blower (29) for supplying air and oxygen, the Roots blower (29) being arranged on the left side of the kiln (1), the Roots blower (29) being connected to the kiln (1) via an air supply duct (30), the flue gas system further comprising a dust removal duct (31), the dust removal duct (31) being connected to the interior of the kiln (1), and a dust removal hood (32) being arranged above the dust removal duct (31).

6. A limestone calcining equipment according to claim 2, characterized in that: The dimensions of the secondary high-alumina bricks of the working layer (14) are: width 110mm / width 150mm*thickness 75mm*length 345mm, the dimensions of the second ring (15) clay refractory bricks are: width 150mm / width 135mm*thickness 75mm*length 230mm, and the dimensions of the third ring (16) lightweight insulation bricks are: width 150mm / width 135mm*thickness 75mm*length 230mm.

7. A limestone calcining equipment according to claim 2, characterized in that: The nodes of the cooling zone (20) and the calcining zone (19) are provided with a buffer zone (21) for centralized air and oxygen supply, and the height of the buffer zone (21) is set to 3-5 meters.

8. A limestone calcining equipment according to claim 1, characterized in that: The flue gas system further comprises an air supply monitoring module, which comprises a gas flow detector (33), an oxygen monitor and a thermocouple, wherein the gas flow detector (33) is arranged inside the air supply duct (30), and the oxygen detector and the thermocouple are arranged inside the dust removal duct (31).

9. A process according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: The mixture of limestone and coal is unloaded onto the belt conveyor (2), and the plough-type unloader (3) executes the signal given by the central control to unload the raw materials into the corresponding first lower hopper (4); S2: the first lower hopper (4) discharges the mixed material into the first receiving hopper (5), and the mixed material in the first receiving hopper (5) is discharged into the second receiving hopper (7) by controlling the switch of the kiln gate (6), and the mixed material in the second receiving hopper (7) is evenly distributed into the kiln (1) through the rotating distributor (8); S3: After the mixed material is preheated in the preheating zone (18), it is calcined in the calcining zone (19). During the calcining process, the Roots blower (29) is used to supply air and oxygen to the kiln (1); finally, it is cooled in the cooling zone (20) to finally generate finished quicklime; S4: Discharging the product quicklime from the disc ash discharger at the bottom of the kiln (1).

10. The process of a limestone calcining equipment according to claim 9, characterized in that: The rotating speed of the rotary distributor (8) is 7 r / min, the diameter of the material is 3.4-4.0, and the material distribution capacity is 500m 3 / d; the flow rate of the Roots blower (29) is 264m 3 / min, the boost pressure is 101.3Kpa; the ash discharge capacity of the disc ash discharger is 84t / h, the speed is 2-3m 3 / min; the preheating temperature is set to 550-800°C, the calcination temperature is set to 1000-1300°C, the calcination time is 4-6 hours, and the cooling temperature is set to 40-60°C.

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