CN-121804193-B - Lime kiln with vacuum annular structure

CN121804193BCN 121804193 BCN121804193 BCN 121804193BCN-121804193-B

Abstract

The invention relates to the technical field of lime kilns, in particular to a lime kiln with a vacuum annular structure, which comprises a feeding section, a preheating section, a combustion section and a cooling section, wherein the preheating section, the combustion section and the cooling section are sequentially and hermetically connected below the feeding section, the preheating section, the combustion section and the cooling section are all annular in shape and are internally provided with a first heat transfer wall and a second heat transfer wall which are concentrically arranged, a material channel is formed between the first heat transfer wall and the second heat transfer wall, and the lime kiln with the vacuum annular structure realizes the indirect treatment of the whole flow of limestone heating, preheating and cooling through the independent cavity design of the annular material channel, a combustion chamber, a flue gas chamber and the like, and carbon dioxide generated by decomposition flows only in the airtight material channel, so that mixed dilution is avoided from the source, high-purity carbon dioxide can be obtained without complex separation and purification equipment, and recycling efficiency is improved.

Inventors

LI ZHENGFU
WANG ZHANSONG
YAN YONGPU
Gao Xianshen
WANG TIANQING
WEI FUAN
HUANG LIGANG
YU DELIANG
LI NINGYAN

Assignees

浙江源程冶金科技发展有限公司

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (9)

1. A lime kiln of vacuum annular structure comprising a feed section (10), characterized in that it further comprises: The preheating section (20), the combustion section (30) and the cooling section (40) are sequentially and hermetically connected below the feeding section (10), the preheating section (20), the combustion section (30) and the cooling section (40) are annular in shape and are internally provided with a first heat transfer wall (31) and a second heat transfer wall (32) which are concentrically arranged, the inner diameter of the first heat transfer wall (31) is larger than the outer diameter of the second heat transfer wall (32), a material channel (33) is formed between the first heat transfer wall (31) and the second heat transfer wall (32), the material channels (33) positioned inside the preheating section (20), the combustion section (30) and the cooling section (40) are mutually communicated, the combustion section (30) comprises an outer cylinder body (34), a heat preservation layer (35), a fire-resistant layer (36), a flue gas channel (39) and an inner cylinder body (310), the heat preservation layer (35) is connected with the inner wall of the outer cylinder body (34), the first heat transfer wall (31) arranged inside the combustion section (30) is positioned inside the fire-resistant layer (36), the first heat transfer layer (30) is arranged inside the fire-resistant layer (30) and the fire-resistant layer (30) is positioned inside the fire-resistant layer (30), the flue gas passage (39) is arranged between a first heat transfer wall (31) and a second heat transfer wall (32) which are arranged in the combustion section (30), and the inner cylinder body (310) is arranged in the flue gas chamber (38); the discharging section (50) is connected with the bottom of the cooling section (40), and the discharging section (50) and the feeding section (10) are connected with vacuumizing equipment.
2. The lime kiln with the vacuum ring structure according to claim 1, wherein an indirect heat exchange device I is arranged in the cooling section (40), the indirect heat exchange device I is communicated with the inner cylinder body (310), the indirect heat exchange device I is connected with an air supply device, the air supply device is used for generating combustion air, and the indirect heat exchange device I is used for conveying the preheated combustion air in the cooling section (40) to the inner cylinder body (310).
3. The lime kiln with the vacuum annular structure according to claim 1, wherein the interior of the preheating section (20) is provided with indirect heat exchange equipment II and direct heat exchange equipment, the indirect heat exchange equipment II is communicated with a flue gas chamber (38), the indirect heat exchange equipment II is externally connected with a flue gas pipeline (21), the flue gas pipeline (21) is connected with a flue gas purifying device, the direct heat exchange equipment is connected with a carbon dioxide recovery pipe (22), the carbon dioxide recovery pipe (22) is connected with a vacuum pump group, and the vacuum pump group is connected with a carbon dioxide recovery device.
4. The lime kiln with the vacuum annular structure according to claim 1, wherein at least four groups of burners (311) are uniformly arranged on the outer peripheral surface above the combustion section (30) along the circumferential direction, combustion air interfaces are arranged on each group of burners (311), each combustion air interface is communicated with the inner cylinder body (310) through a pipeline and is used for conveying combustion air in the inner cylinder body (310) to the inside of the burners (311), each group of burners (311) is connected with a fuel regulation control device, and each fuel regulation control device is connected with a fuel conveying pipeline.
5. A lime kiln with a vacuum ring structure according to claim 2, characterized in that the air supply device comprises a fan (51) and a combustion air duct (52), the fan (51) is arranged at one side of the discharge section (50), the combustion air duct (52) is connected with the fan (51), the combustion air duct (52) is arranged in a ring shape outside the cooling section (40), and the ring-shaped part of the combustion air duct (52) is connected with the indirect heat exchange equipment one through the duct.
6. The lime kiln with the vacuum ring structure according to claim 1, wherein the discharging section (50) and the feeding section (10) are vacuum tanks with sealed ends, and an upper sealing valve and a lower sealing valve are arranged on the discharging section (50) and the feeding section (10).
7. The lime kiln with the vacuum ring structure according to claim 1, wherein a plurality of observation windows (312) are arranged among the heat insulation layer (35), the fire-resistant layer (36) and the outer cylinder body (34), the observation windows (312) correspond to the number of flue gas passages (39), and the observation windows (312) correspond to the positions of the flue gas passages (39).
8. The lime kiln with the vacuum annular structure according to claim 1, wherein the first heat transfer wall (31) and the second heat transfer wall (32) are annular structures formed by one of silicon carbide bricks, silicon carbide plates or heat-resistant steel, the inner cylinder body (310) is one of silicon carbide pipes or heat-resistant steel pipes, the heat-insulating layer (35) is an annular structure formed by heat-insulating bricks, and the refractory layer (36) is an annular structure formed by refractory bricks.
9. The lime kiln with the vacuum ring structure according to claim 1, wherein the feeding section (10) is connected with a feeding bin (11), a feeding port of the feeding bin (11) is connected with an automatic feeding device (12), and a storage bin (13) is arranged at the bottom of the automatic feeding device (12).

Description

Lime kiln with vacuum annular structure Technical Field The invention relates to the technical field of lime kilns, in particular to a lime kiln with a vacuum annular structure. Background Lime is used as a key basic raw material in the fields of metallurgy, chemical industry, building materials and the like, the core production process is limestone calcination decomposition reaction, and a lime kiln is core equipment for realizing the reaction. At present, the main stream limestone calcining technology in industry mainly comprises direct calcining, including shaft kiln, rotary kiln, sleeve kiln and other traditional equipment, and the basic principle is that fuel and limestone are directly contacted and combusted, heat transfer is realized through flame radiation and smoke convection, and the limestone reaches decomposition temperature to complete calcining. In the traditional direct calcination process, carbon dioxide generated by limestone decomposition is directly mixed with fuel combustion flue gas and combustion air, so that the carbon dioxide is greatly diluted, the purity is obviously reduced, complicated separation and purification equipment is required to be input in the follow-up process if the carbon dioxide is to be recovered, the production cost is increased, the problems of low recovery efficiency, high energy consumption and the like are also solved, the traditional direct calcination equipment is mainly aimed at large-particle-size limestone, the specific surface area of the small-particle-size limestone is large, and the problems of excessively rapid surface sintering and undegraded sandwich inside are easily caused when the limestone is in direct contact with high-temperature flame, so that the calcination is uneven and the underburn rate is high. There is a need for a vacuum ring structure lime kiln to solve the above-mentioned problems. Disclosure of Invention The invention provides a lime kiln with a vacuum annular structure, and aims to solve the technical problems that direct calcination is inconvenient for recovering carbon dioxide and direct calcination is not suitable for small-particle-size limestone in the related art. The invention relates to a lime kiln with a vacuum ring structure, which comprises a feeding section and further comprises: The preheating section, the combustion section and the cooling section are sequentially and hermetically connected below the feeding section, the preheating section, the combustion section and the cooling section are annular in shape, a first heat transfer wall and a second heat transfer wall which are concentrically arranged are arranged inside the preheating section, a material channel is formed between the first heat transfer wall and the second heat transfer wall, the material channels inside the preheating section, the combustion section and the cooling section are mutually communicated, the combustion section comprises an outer cylinder body, a heat preservation layer, a fire-resistant layer, a flue gas chamber, a flue gas passage and an inner cylinder body, the heat preservation layer is connected with the inner wall of the outer cylinder body, the fire-resistant layer is connected with the inner wall of the heat preservation layer, the first heat transfer wall arranged inside the combustion section is positioned inside the fire-resistant layer, a combustion chamber is formed between the first heat transfer wall and the fire-resistant layer arranged inside the combustion section, the flue gas chamber is positioned inside the second heat transfer wall arranged inside the combustion section, the number of the flue gas passage is multiple groups, the flue gas passage is arranged between the first heat transfer wall and the second heat transfer wall arranged inside the combustion section, and the inner cylinder body is arranged inside the flue gas chamber; And the discharging section is connected with the bottom of the cooling section, and the discharging section and the feeding section are both connected with a vacuum pumping device which is used for enabling the whole material to be still in a vacuum state after entering the interior of the preheating section and after being discharged from the discharging section. Preferably, the cooling section is internally provided with an indirect heat exchange device I, the indirect heat exchange device I is communicated with the inner cylinder body, the indirect heat exchange device I is connected with an air supply device, the air supply device is used for generating combustion air, and the indirect heat exchange device I is used for conveying the preheated combustion air in the cooling section to the inner cylinder body. The indirect heat exchange device has the advantages that the indirect heat exchange between the combustion air and the calcium oxide is realized, the waste heat of the combustion air is recovered on the premise of not polluting the calcium oxide, the temperature of the combusti