Six-stage preheating and predecomposing cement kiln

Abstract

The utility model discloses a six-stage preheating predecomposition cement kiln which comprises an installation platform, a first preheating mechanism is arranged at the top end of the installation platform, a second preheating mechanism is arranged at the top end of the first preheating mechanism, a feeding mechanism is installed at the top end of the second preheating mechanism, and a material layer is arranged in the feeding mechanism. A third preheating mechanism is arranged at the bottom end of the first preheating mechanism, and a discharging mechanism is installed on one side of the third preheating mechanism. The four preheating mechanisms are additionally arranged at the top end of the first preheating mechanism, and the volutes in the first preheating mechanism, the second preheating mechanism and the third preheating mechanism are expanded, so that air resistance is reduced, and materials can be subjected to more sufficient heat exchange with high-temperature airflow in the preheating stage. Materials are gradually heated in the preheaters at all levels, the temperature is closer to the decomposition temperature, and after entering the decomposition furnace and the rotary kiln, the materials can absorb heat more quickly to react.

Description

Technical Field

[0001] This utility model relates to the field of cement kiln technology, specifically a six-stage preheating and pre-decomposition cement kiln. Background Technology

[0002] Cement kilns are core equipment in the cement industry, primarily used for high-temperature calcination of raw materials such as limestone and clay to produce cement clinker. Their working principle involves decomposing the carbonates in the raw materials at temperatures of 1300-1450℃ to form clinker minerals, mainly calcium silicate. Modern kilns integrate efficient combustion, waste heat recovery, and emission reduction technologies, possessing continuous operation, high capacity, and environmental protection characteristics, supporting the large-scale and green development of the cement industry.

[0003] However, conventional five-stage cement kilns require a higher combustion temperature in the rotary kiln to bring the material to the required reaction temperature. This requires more fuel, and due to insufficient heat exchange, some heat is discharged with the exhaust gas, resulting in energy waste. Utility Model Content

[0004] The purpose of this invention is to provide a six-stage preheating and pre-decomposition cement kiln to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a six-stage preheating and pre-decomposition cement kiln, comprising an installation platform, a first preheating mechanism at the top of the installation platform, a second preheating mechanism at the top of the first preheating mechanism, a feeding mechanism at the top of the second preheating mechanism, a material layer inside the feeding mechanism, a third preheating mechanism at the bottom of the first preheating mechanism, and a discharge mechanism on one side of the third preheating mechanism.

[0006] Preferably, the first preheating mechanism includes a first cyclone cylinder installed inside the top of the mounting platform, and a first volute is installed at the top of the first cyclone cylinder.

[0007] Preferably, the second preheating mechanism includes four sets of preheating cyclones evenly installed at equal intervals on the top of the installation platform, and the bottom end of the preheating cyclones is connected to the first volute.

[0008] Preferably, the feeding mechanism includes a second cyclone installed at the top of the preheating cyclone, a first feed inlet installed at the top of one side of the second cyclone, and a spiral channel provided on one side of the first feed inlet.

[0009] Preferably, the material layer includes a heat-resistant layer disposed inside the second cyclone, the heat-resistant layer being made of refractory brick, a strength layer disposed inside the heat-resistant layer being made of manganese steel, a thermal expansion layer disposed inside the strength layer being made of a ceramic and graphene composite material, and a corrosion-resistant layer disposed inside the thermal expansion layer being made of Hastelloy.

[0010] Preferably, the third preheating mechanism includes a third cyclone installed at the bottom of the first cyclone, a fourth cyclone installed at the bottom of the third cyclone, a fifth cyclone installed at the bottom of the fourth cyclone, and a sixth cyclone installed at the bottom of the fifth cyclone.

[0011] Preferably, the discharge mechanism includes a decomposition furnace installed at the middle position on one side of the installation platform, a second feed inlet installed at the bottom end of one side of the decomposition furnace, and a material discharge outlet installed at the bottom end of the decomposition furnace.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. This six-stage preheating and pre-decomposition cement kiln, by adding four sets of preheating units at the top of the first preheating unit and enlarging the volutes in the first, second, and third preheating units, reduces air resistance and allows for more thorough heat exchange between the material and the high-temperature airflow during the preheating stage. The material gradually heats up in each preheater, approaching its decomposition temperature, and then absorbs heat and reacts more quickly upon entering the decomposition furnace and rotary kiln.

[0014] 2. This type of six-stage preheating and pre-decomposition cement kiln incorporates a material layer within the second cyclone separator, which includes a heat-resistant layer, a strength layer, a thermal expansion layer, and a corrosion-resistant layer. The heat-resistant and strength layers significantly enhance the high-temperature resistance and wear resistance of the second cyclone separator. The thermal expansion layer within the strength layer provides excellent thermal expansion properties, effectively reducing thermal stress under high-temperature variations and preventing deformation or cracking of the volute. The innermost corrosion-resistant layer effectively prevents corrosion, maintaining the stability and lifespan of the volute. This not only extends the service life of the cement kiln cyclone separator but also reduces maintenance frequency, improving the overall reliability and energy efficiency of the equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This utility model Figure 1 Enlarged structural diagram at point A in the middle;

[0017] Figure 3 This is a schematic diagram of the overall structure of the feeding mechanism of this utility model;

[0018] Figure 4 This utility model Figure 3 Enlarged structural diagram at point B.

[0019] In the diagram: 1. Installation platform; 2. First preheating mechanism; 201. First cyclone; 202. First volute; 3. Second preheating mechanism; 301. Preheating cyclone; 4. Feeding mechanism; 401. Second cyclone; 402. First feed inlet; 403. Spiral channel; 5. Material layer; 501. Heat-resistant layer; 502. Strength layer; 503. Thermal expansion layer; 504. Corrosion-resistant layer; 6. Third preheating mechanism; 601. Third cyclone; 602. Fourth cyclone; 603. Fifth cyclone; 604. Sixth cyclone; 7. Discharge mechanism; 701. Decomposition furnace; 702. Second feed inlet; 703. Material discharge outlet. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-4 This utility model provides two technical solutions:

[0022] Example 1: A six-stage preheating and pre-decomposition cement kiln includes an installation platform 1, a first preheating mechanism 2 at the top of the installation platform 1, a second preheating mechanism 3 at the top of the first preheating mechanism 2, a feeding mechanism 4 at the top of the second preheating mechanism 3, a material layer 5 inside the feeding mechanism 4, a third preheating mechanism 6 at the bottom of the first preheating mechanism 2, and a discharge mechanism 7 on one side of the third preheating mechanism 6.

[0023] The first preheating mechanism 2 includes a first cyclone 201 installed inside the top of the installation platform 1. A first volute 202 is installed at the top of the first cyclone 201. After the raw material enters the first cyclone 201 through the first volute 202, it undergoes preliminary heat exchange and separation with the high-temperature airflow inside the first cyclone 201, and the material enters the next stage.

[0024] The second preheating mechanism 3 includes four sets of preheating cyclones 301 evenly installed at equal intervals on the top of the installation platform 1. The bottom end of the preheating cyclone 301 is connected to the first volute 202. It adopts a four-core large volute structure and an expanded diameter cone design to reasonably control the inlet wind speed and the wind speed of the column section, improve dust collection efficiency, and reduce resistance. After the raw material enters, it undergoes preliminary heat exchange and separation with the high-temperature airflow, and the material enters the first preheating mechanism 2.

[0025] The feeding mechanism 4 includes a second cyclone 401 installed at the top of the preheating cyclone 301. A first feed inlet 402 is installed at the top of one side of the second cyclone 401. A spiral channel 403 is provided on one side of the first feed inlet 402. The spiral channel 403 is provided inside the second cyclone 401. When the dust-laden airflow enters the second cyclone 401 tangentially, it rotates on the spiral channel 403 inside the cylinder. Solid particles are thrown towards the cylinder wall due to centrifugal force and then fall down along the cylinder wall, thus achieving gas-solid separation.

[0026] The third preheating mechanism 6 includes a third cyclone 601 installed at the bottom of the first cyclone 201, a fourth cyclone 602 installed at the bottom of the third cyclone 601, a fifth cyclone 603 installed at the bottom of the fourth cyclone 602, and a sixth cyclone 604 installed at the bottom of the fifth cyclone 603. By increasing the height of the volute to expand the inlet area, replacing the inner cylinder and increasing the insertion depth, the gas-solid separation efficiency is optimized and the wind resistance is reduced. The material falls step by step, exchanging heat with the rising hot airflow in the opposite direction, and the temperature gradually increases.

[0027] The discharge mechanism 7 includes a decomposition furnace 701 installed in the middle of one side of the installation platform 1. A second feed port 702 is installed at the bottom of one side of the decomposition furnace 701, and a material discharge port 703 is installed at the bottom of the decomposition furnace 701. One side of the material discharge port 703 is connected to an external rotary kiln. At the same time, the second feed port 702 on one side of the decomposition furnace 701 can introduce pulverized coal into the interior of the decomposition furnace 701. At this time, the decomposition furnace 701 provides combustion space for the pulverized coal, so that the fuel can be fully burned in the furnace.

[0028] Example 2 differs from Example 1 mainly in that:

[0029] A six-stage preheating and pre-decomposition cement kiln includes a heat-resistant layer 501 inside the second cyclone 401 in the material layer 5. The heat-resistant layer 501 is made of refractory brick and can withstand the high-temperature environment inside the cement kiln, effectively protecting the inner material from high-temperature damage.

[0030] The heat-resistant layer 501 has an internal strength layer 502 made of manganese steel, which greatly improves wear resistance and reduces damage to the equipment caused by friction.

[0031] The strength layer 502 has a thermal expansion layer 503 inside. The thermal expansion layer 503 is made of ceramic and graphene composite material, which has excellent thermal expansion performance. It can effectively reduce thermal stress under high temperature changes and avoid deformation or cracking of the volute.

[0032] The thermal expansion layer 503 is internally provided with a corrosion-resistant layer 504, which is made of Hastelloy alloy. This effectively reduces the corrosion caused by acidic gases and chemicals generated during cement production, maintaining the stability and lifespan of the volute. Meanwhile, all contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0033] In this embodiment, the main raw materials, such as limestone, clay, and iron ore, are crushed to meet the particle size requirements. They are then accurately proportioned and thoroughly mixed, ground into raw meal, and fed into the second preheating mechanism 3 from the top. The raw meal passes through various cyclones, exchanging heat with the high-temperature airflow rising from the decomposition furnace and kiln, thus gradually preheating. The preheated raw meal enters the decomposition furnace 701, where it reacts fully with the heat generated by the combustion of pulverized coal entering through the second feed inlet 702, completing carbonate decomposition and denitrification. Subsequently, the material falls into the material discharge outlet 703, passes through the smoke chamber, and enters the rotary kiln for calcination into clinker.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A six-stage preheater precalciner cement kiln comprising a mounting platform (1), characterised in that: The top end of the mounting platform (1) is provided with a first preheating mechanism (2), the top end of the first preheating mechanism (2) is provided with a second preheating mechanism (3), the top end of the second preheating mechanism (3) is provided with a feeding mechanism (4), the inside of the feeding mechanism (4) is provided with a material layer (5), the bottom end of the first preheating mechanism (2) is provided with a third preheating mechanism (6), one side of the third preheating mechanism (6) is provided with a discharging mechanism (7).

2. A six-stage preheater precalciner cement kiln according to claim 1, characterised in that: The first preheating mechanism (2) comprises a first cyclone (201) mounted at the top end of the mounting platform (1), and the top end of the first cyclone (201) is provided with a first volute (202).

3. A six-stage preheater precalciner cement kiln according to claim 2, characterised in that: The second preheating mechanism (3) comprises four groups of preheating cyclones (301) mounted at the top end of the mounting platform (1) in equal distance and uniformity, and the bottom end of the preheating cyclone (301) is communicated with the first volute (202).

4. A six-stage preheater precalcinator cement kiln as claimed in claim 3 wherein: The feeding mechanism (4) comprises a second cyclone (401) mounted at the top end of the preheating cyclone (301), a first feeding port (402) is mounted at the top end of one side of the second cyclone (401), and a spiral channel (403) is arranged on one side of the first feeding port (402).

5. A six-stage preheater precalcinator cement kiln as claimed in claim 4 wherein: The material layer (5) comprises a heat-resistant layer (501) arranged in the second cyclone (401), the heat-resistant layer (501) is made of refractory bricks, a strength layer (502) is arranged in the heat-resistant layer (501), the strength layer (502) is made of manganese steel, a thermal expansion layer (503) is arranged in the strength layer (502), the thermal expansion layer (503) is made of a composite material of ceramic and graphene, a corrosion-resistant layer (504) is arranged in the thermal expansion layer (503), and the corrosion-resistant layer (504) is made of hastelloy.

6. A six-stage preheater precalcinator cement kiln as claimed in claim 2, wherein: The third preheating mechanism (6) comprises a third cyclone (601) mounted at the bottom end of the first cyclone (201), a fourth cyclone (602) is mounted at the bottom end of the third cyclone (601), a fifth cyclone (603) is mounted at the bottom end of the fourth cyclone (602), and a sixth cyclone (604) is mounted at the bottom end of the fifth cyclone (603).

7. A six-stage preheater precalcinator cement kiln as claimed in claim 6 wherein: The discharging mechanism (7) comprises a decomposition furnace (701) mounted at the middle position of one side of the mounting platform (1), a second feeding port (702) is mounted at the bottom end of one side of the decomposition furnace (701), and a material discharge port (703) is mounted at the bottom end of the decomposition furnace (701).

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