A limestone calcining apparatus having three kiln chambers and a calcining method thereof

Abstract

The present application relates to a kind of limestone calcining equipment with three kiln and its calcining method, belong to metallurgical industry lime kiln calcining equipment technical field.The technical scheme is: including a rectangular hearth and two D-shaped hearth, two D-shaped hearth is symmetrically arranged in rectangular hearth two sides, constitute three kiln, adjacent two kiln is connected through connecting channel (8) intercommunication;The upper part of three kiln is preheating zone, middle part is calcining zone or regenerative zone, lower part is cooling zone, the upper part of each kiln is equipped with lance (7) and combustion air inlet, the beneficial effects of the present application are: three kiln function is transformed when calcining each other, three hearth lime kiln is based on double hearth lime kiln and increases a kiln, with single seat kiln high yield, low investment characteristics.It is the organic combination of double D-shaped kiln and double rectangular kiln, with the advantages of short channel of double D-shaped kiln double rectangular kiln, long service life.

Description

Technical Field

[0001] This invention relates to a limestone calcination device with three kiln chambers and its calcination method, belonging to the technical field of lime kiln calcination equipment in the metallurgical industry. Background Technology

[0002] A vertical kiln is a thermal equipment for continuously calcining clinker, with feeding from the top and discharging from the bottom. It consists of a kiln body, feeding and discharging devices, and ventilation equipment. Its advantages include lower infrastructure investment, smaller footprint, high calcination efficiency, low fuel consumption, and ease of mechanization and automation.

[0003] Currently, the widely used vertical lime kiln cross-sections include: circular, D-shaped, rectangular, C-shaped, and elliptical. Each kiln shape has its own advantages and disadvantages, with the circular cross-section having the fewest disadvantages and being the most commonly used kiln shape in operation. However, circular cross-section lime kilns also have their drawbacks. As the diameter of the kiln cross-section increases, the airflow deviation within the kiln also increases. Other kiln shapes exhibit the same problem, which explains the slow development of larger kiln shapes. Summary of the Invention

[0004] The purpose of this invention is to provide a limestone calcination device and calcination method with three kiln chambers, which has low investment, high output, and the airflow in the three kiln chambers can cancel each other out, thus solving the problems existing in the background technology.

[0005] The technical solution of this invention is: A limestone calcining device with three kiln chambers includes a rectangular chamber and two D-shaped chambers. The two D-shaped chambers are symmetrically arranged on both sides of the rectangular chamber to form three kiln chambers. Adjacent kiln chambers are connected by a connecting channel. The upper part of the three kiln chambers is a preheating zone, the middle part is a calcination zone or a heat storage zone, and the lower part is a cooling zone. Each kiln chamber is equipped with a spray gun and a combustion air inlet at the top.

[0006] The sum of the cross-sectional areas of the two D-shaped bores is equal to the area of ​​the rectangular bore.

[0007] The connecting channel between two adjacent kiln chambers is located in the cooling zone at the bottom of the kiln chamber.

[0008] A method for calcining limestone with three kiln chambers, employing the aforementioned limestone calcining equipment with three kiln chambers, and operating as follows: When the two D-shaped kiln chambers are used as calcining chambers and the rectangular chamber is used as a heat storage chamber, the combustion air enters the kiln chamber from the top of the two D-shaped kiln chambers. After exchanging heat with the limestone in the preheating zone of the D-shaped kiln, the combustion air mixes and burns with the fuel entering the kiln chamber through the spray gun in the calcining zone. The resulting hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel between the two chambers and then enters the heat storage zone of the rectangular chamber through the connecting channel. The cooling air from the two D-shaped kilns flows upward through the cooling zone of the D-shaped kiln. When it rises to the connecting channel between the two chambers, it enters the heat storage zone of the rectangular chamber through the connecting channel. The cooling air from the rectangular chamber flows upward through the cooling zone of the rectangular chamber and enters the heat storage zone of the rectangular chamber. The three cooling air streams and the two hot flue gas streams pass in parallel through the heat storage zone of the rectangular chamber and enter the preheating zone of the rectangular chamber. The mixed gas is discharged from the top of the rectangular chamber, completing one calcination cycle. When the rectangular kiln chamber is used as the calcining chamber and the two D-shaped chambers are used as regenerator chambers, the combustion air enters the kiln chamber from the top of the rectangular kiln chamber. After exchanging heat with the limestone in the preheating zone of the rectangular kiln chamber, the combustion air mixes and burns with the fuel entering the kiln chamber through the spray gun in the calcining zone. The resulting hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel between the two chambers and then enters the regenerator zone of the D-shaped chamber through the connecting channel, forming two flue gas streams. The cooling air in the rectangular kiln chamber flows upward through the cooling zone of the rectangular kiln chamber. When it rises to the connecting channel between the two chambers, it enters the regenerator zone of the two D-shaped chambers through the connecting channel, forming two air streams. The cooling air in the D-shaped chamber chamber flows upward through the cooling zone of the D-shaped chamber and enters the regenerator zone of the D-shaped chamber. The three cooling air streams and the two hot flue gas streams pass in parallel through the regenerator zones of the two D-shaped chambers and enter the preheating zones of the two D-shaped chambers. The mixed gas is discharged from the top of the two D-shaped chambers, completing one calcination cycle.

[0009] The rectangular kiln chamber and the two D-shaped kiln chambers switch functions every 12-15 minutes, and each switch completes one heating and decomposition of the limestone in the calcining chamber.

[0010] The beneficial effects of this invention are as follows: The three-chamber lime kiln of this invention adds a kiln chamber to the double-chamber lime kiln. It is not simply adding a kiln chamber of the same size, but rather adding a kiln chamber with twice the cross-sectional area, thus doubling its output. It features high output per kiln and low investment. It is an organic combination of a double D-shaped kiln and a double rectangular kiln. It possesses the advantages of short passages, less ash accumulation, and long service life of both double D-shaped and double rectangular kilns. Furthermore, the combination of D-shape and rectangle solves the problem of the long side dimension of the rectangular kiln not being able to be designed too large, and the organic combination of the uniform stress on the round (arc) side of the D-shape turns the disadvantages of the rectangle into advantages, maximizing the strengths of the D-shaped kiln. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the EE of the present invention; Figure 3 This is a schematic diagram of the BB cross-section structure of the present invention; Figure 4 This is a schematic diagram of the CC cross-section structure of the present invention; Figure 5 This is a schematic diagram of the DD cross-sectional structure of the present invention; Figure 6 The diagram shows the airflow direction with the combustion chamber in the middle and the heat storage chambers on both sides. Figure 7 The diagram shows the airflow direction of the heat storage chamber in the middle and the combustion chamber on both sides. Figure 8 This is a schematic diagram comparing the area and airflow of a rectangular bore and a D-shaped bore; Figure 9 These are schematic diagrams illustrating the force analysis of rectangular and D-shaped bores; In the diagram: 1. Rectangular preheating zone; 2. D-shaped preheating zone; 3. Rectangular calcination zone (heat storage zone); 4. D-shaped calcination zone (heat storage zone); 5. Rectangular cooling zone; 6. D-shaped cooling zone; 7. Spray gun; 8. Connecting channel; 9. Kiln wall; 10. Kiln channel arch support wall; 11. Material inside the kiln. Detailed Implementation

[0012] The invention will be further described below with reference to the accompanying drawings and examples.

[0013] See attached document Figure 1-9 A limestone calcination device with three kiln chambers is characterized in that: it includes a rectangular chamber and two D-shaped chambers, the two D-shaped chambers are symmetrically arranged on both sides of the rectangular chamber to form three kiln chambers, and the adjacent two kiln chambers are connected by a connecting channel (8); the upper part of the three kiln chambers is a preheating zone, the middle part is a calcination zone or a heat storage zone, and the lower part is a cooling zone, and each kiln chamber is provided with a spray gun (7) and a combustion air inlet at the upper part.

[0014] In this embodiment, see Figure 1-9This limestone calcination equipment is an organic combination of a double D-shaped kiln and a double rectangular kiln. The two D-shaped kiln chambers of the double D-shaped kiln are arranged on both sides, including a rectangular preheating zone 1, a D-shaped preheating zone 2, a rectangular calcination zone (storage zone) 3, a D-shaped calcination zone (storage zone) 4, a rectangular cooling zone 5, a D-shaped cooling zone 6, spray guns 7, a connecting channel between the two chambers 8, kiln walls 9, and a kiln channel arch support wall 10. The two rectangular kiln chambers of the double rectangular kiln are arranged side-by-side to form a large kiln chamber, the cross-sectional area of ​​which is equal to the cross-sectional area of ​​the two rectangular kiln chambers. The large rectangular kiln chamber has two fewer walls than the two rectangular kiln chambers, therefore the investment in this three-chamber kiln is lower than the combined investment of a single double D-shaped kiln and a double rectangular kiln. It is equivalent to two double-chamber kilns composed of one D-shaped kiln chamber and one rectangular kiln chamber. Its calcination principle is the same as all double-chamber kilns, and its calcination quality is the same as that of double D-shaped and double rectangular kilns. Multiple spray guns are installed within the preheating zone, with the nozzles located at the top of the calcination and storage zones.

[0015] Please refer to the attached diagram. Figure 7 When the two D-shaped kiln chambers are used as calcining chambers and the rectangular chamber is used as a heat storage chamber, the combustion air enters the kiln chamber from the top of the D-shaped kiln chamber. After exchanging heat with the limestone in the preheating zone 2 of the D-shaped kiln chamber, the combustion air mixes and burns with the fuel entering the kiln chamber through the spray gun 7 in the calcining zone 4. The generated hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel 8 between the two chambers and then enters the heat storage zone 3 of the rectangular chamber through the connecting channel 8. The lime cooling air enters the cooling zone from the bottom of the cooling zone. The D-shaped kiln cooling air flows upward through the D-shaped kiln cooling zone 6. When it rises to the connecting channel 8 between the two chambers, it enters the heat storage zone 3 of the rectangular chamber through the connecting channel 8. The rectangular kiln cooling air flows upward through the rectangular kiln cooling zone 5 and enters the heat storage zone 3 of the rectangular chamber. The three cooling airs and two hot flue gas enter the rectangular kiln preheating zone 1 of the rectangular kiln in parallel through the heat storage zone 3 of the rectangular chamber. The mixed gas is discharged from the top of the rectangular kiln, completing one calcination cycle.

[0016] See attached document Figure 6When one rectangular kiln chamber serves as the calcining chamber and two D-shaped chambers serve as the heat storage chambers, combustion air enters the kiln chamber from the top of the rectangular kiln chamber. After exchanging heat with limestone in the preheating zone 1 of the rectangular kiln chamber, the combustion air mixes and burns with the fuel entering the kiln chamber through the spray gun 7 in the calcining zone 3. The resulting hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel 8 between the two chambers and then enters the heat storage zone 4 of the D-shaped chamber through the connecting channel 8, forming two flue gas streams. Lime cooling air enters the cooling zone from the bottom of the cooling zone. The rectangular kiln cooling air flows upward through the rectangular kiln cooling zone 5. When it rises to the connecting channel 8 between the two chambers, it enters the heat storage zones 4 of the two D-shaped chambers through the connecting channel 8, forming two air streams. The D-shaped kiln cooling air flows upward through the D-shaped kiln cooling zone 6 and enters the heat storage zone 4 of the D-shaped chamber. The three cooling air streams (four air streams) and the two hot flue gas streams pass in parallel through the heat storage zone 3 of the D-shaped chamber and enter the preheating zone 2 of the D-shaped chamber. The mixed gas is discharged from the top of the D-shaped chamber, completing one calcination cycle.

[0017] The function of the kiln chamber is switched every 12-15 minutes between the D-shaped kiln chamber and the rectangular kiln chamber. Each switch completes the heating and decomposition of the limestone in the calcining chamber.

[0018] See attached document Figure 8 A rectangular kiln chamber has a smaller width for the same cross-sectional area, resulting in less airflow deviation, but weaker resistance to bending on a flat surface. A D-shaped kiln chamber has a larger width for the same cross-sectional area, resulting in greater airflow deviation, but stronger resistance to bending on a curved surface. The effects of the three kiln chambers cancel each other out, as shown in the attached diagram. Figure 9 As shown.

Claims

1. A limestone calcination device with three kiln chambers, characterized in that: It includes a rectangular chamber and two D-shaped chambers. The two D-shaped chambers are symmetrically arranged on both sides of the rectangular chamber to form three kiln chambers. The two adjacent kiln chambers are connected by a connecting channel (8). The upper part of the three kiln chambers is the preheating zone, the middle part is the calcination zone or heat storage zone, and the lower part is the cooling zone. Each kiln chamber is equipped with a spray gun (7) and a combustion air inlet at the top.

2. The limestone calcination equipment with three kiln chambers according to claim 1, characterized in that: The sum of the cross-sectional areas of the two D-shaped bores is equal to the area of ​​the rectangular bore.

3. A limestone calcination device with three kiln chambers according to claim 1, characterized in that: The connecting channel (8) between two adjacent kiln chambers is located in the cooling zone at the bottom of the kiln chamber.

4. A method for calcining limestone with three kiln chambers, characterized in that: The limestone calcining equipment with three kiln chambers as defined in any one of claims 1-3 is used and operated as follows: When the two D-shaped kiln chambers are calcining chambers and the rectangular chamber is a heat storage chamber, the combustion air enters the kiln chamber from the top of the two D-shaped kiln chambers. After the combustion air exchanges heat with the limestone in the preheating zone of the D-shaped kiln chamber, it mixes and burns with the fuel that enters the kiln chamber through the spray gun (7) in the calcining zone. The generated hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel (8) between the two chambers and then enters the heat storage zone of the rectangular chamber through the connecting channel (8). The cooling air of the two D-shaped kilns flows upward through the cooling zone of the D-shaped kiln chamber. When it rises to the connecting channel (8) between the two chambers, it enters the heat storage zone of the rectangular chamber through the connecting channel (8). The cooling air of the rectangular chamber flows upward through the cooling zone of the rectangular chamber and enters the heat storage zone of the rectangular chamber. The three cooling air and the two hot flue gas enter the preheating zone of the rectangular chamber through the heat storage zone of the rectangular chamber in parallel. The mixed gas is discharged from the top of the rectangular chamber, completing one calcination cycle. When the rectangular kiln chamber is the calcination chamber and the two D-shaped chambers are the heat storage chambers, the combustion air enters the kiln chamber from the top of the rectangular kiln chamber. After the combustion air exchanges heat with the limestone in the preheating zone of the rectangular kiln chamber, it mixes and burns with the fuel that enters the kiln chamber through the spray gun (7) in the calcination zone. The generated hot flue gas heats and decomposes the limestone. The flue gas descends to the connecting channel (8) between the two chambers and then enters the heat storage zone of the D-shaped chamber through the connecting channel (8) to form two streams of flue gas flow. The cooling air of the rectangular kiln flows upward through the cooling zone of the rectangular kiln chamber. When it rises to the connecting channel (8) between the two chambers, it enters the heat storage zone of the two D-shaped chambers through the connecting channel (8) to form two streams of air flow. The cooling air of the D-shaped chamber flows upward through the cooling zone of the D-shaped chamber and enters the heat storage zone of the D-shaped chamber. The three cooling air and the two hot flue gas flow in parallel through the heat storage zone of the two D-shaped chambers and enter the preheating zone of the two D-shaped chambers. The mixed gas is discharged from the top of the two D-shaped chambers, completing one calcination cycle.

5. A method for calcining limestone with three kiln chambers according to claim 4, characterized in that: The rectangular kiln chamber and the two D-shaped kiln chambers switch functions every 12-15 minutes, and each switch completes one heating and decomposition of the limestone in the calcining chamber.

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