Mechanical shaft kiln provided with arched girders

Abstract

The mechanical shaft kiln comprises a kiln body, an ejector and a heat exchanger, the arched beam is arranged in the kiln body in a crossing mode, the two ends of the arched beam are fixed to the inner wall of the kiln body, a main burner is arranged below the arched beam and fixed to the inner wall of the kiln body, a combustion chamber is formed between the arched beam and the inner wall of the kiln body, and the main burner is located in the combustion chamber; the interior of the kiln body is divided into a preheating zone, a countercurrent calcining zone, a parallel-flow calcining zone and a cooling zone from top to bottom; high-temperature flue gas generated in the preheating zone and countercurrent calcination enters the heat exchanger through a pipeline, combustion-supporting air heated by the heat exchanger is introduced into the combustion chamber through a central air opening of the ejector, and hot air and hot flue gas after material cooling are introduced into a bypass air opening of the ejector. According to the utility model, reasonable distribution and utilization of heat are realized, and the efficiency and the energy utilization rate of the whole calcining process are improved. The system disclosed by the utility model is more compact and efficient, and can better adapt to the calcining process requirements of different types of materials.

Description

Technical Field

[0001] The utility model relates to the field of vertical kilns, and more particularly to a mechanized vertical kiln provided with arch beams. Background Art

[0002] The telescopic shaft kiln, a lime roasting shaft kiln developed by Germans Karl and Johann Beckenbach in 1960, is also known as the Karl-Beckenbach kiln. Currently one of the most advanced lime roasting shaft kilns in the world, it consists of two concentric circular chambers, with the material contained within the sleeve, while the inner chamber carries cooling air and exhaust gases from fuel combustion. The roasting zone operates in a semi-countercurrent and semi-cocurrent mode, while the preheating zone operates in a countercurrent mode. Its main advantage is its low heat consumption, typically 950 x 4.3 kJ / kg, resulting in finished lime with an activity level exceeding 330 ml. However, the telescopic shaft kiln structure and operation are complex, requiring significant investment. In traditional shaft kilns, hot air and flue gases from the cooling zone are often discharged directly into the environment, resulting in significant energy losses. Summary of the Invention

[0003] The technical problem to be solved by the utility model is to provide a mechanized vertical kiln provided with an arch beam, which realizes the reasonable distribution and utilization of heat and improves the efficiency and energy utilization rate of the entire calcination process.

[0004] The technical solution adopted by the utility model to solve the technical problem is as follows: a mechanized vertical kiln provided with an arch beam is constructed, comprising a kiln body, an ejector and a heat exchanger; an arch beam is arranged across the interior of the kiln body, both ends of the arch beam are fixed to the inner wall of the kiln body, a main burner is arranged below the arch beam, the main burner is fixed to the inner wall of the kiln body, a combustion chamber is formed between the arch beam and the inner wall of the kiln body, and the main burner is located in the combustion chamber;

[0005] The interior of the kiln is divided from top to bottom into a preheating zone, a countercurrent calcining zone, a parallel-flow calcining zone, and a cooling zone. The preheating zone and the countercurrent calcining zone are located above the arch beam, while the parallel-flow calcining zone and the cooling zone are located below the arch beam. In the preheating zone, the material gradually heats up through heat exchange with the rising hot air flow. In the countercurrent calcining zone, the material comes into countercurrent contact with the hot flue gas generated by the main burner, achieving a preliminary calcination reaction. In the parallel-flow calcining zone, the material moves in parallel with the downward high-temperature air flow generated by the main burner, further completing the calcination process. In the cooling zone, the calcined material is cooled by cold air drawn in by a fan.

[0006] The high-temperature flue gas generated by preheating and countercurrent calcination enters the heat exchanger through the pipeline. The combustion air heated by the heat exchanger enters the combustion chamber through the central air port of the injector. The side air port of the injector introduces the hot air and hot flue gas after cooling the material.

[0007] According to the above solution, a plurality of auxiliary burners are provided above the arch beam, and the auxiliary burners are fixed on the inner wall of the kiln body.

[0008] According to the above solution, a central burner is provided below the center of the arch beam, a central support platform is provided at the lower part of the kiln body, and the central burner is arranged on the top of the central support platform.

[0009] According to the above solution, there are one, two or more arch beams, and two or more arch beams are cross-arranged.

[0010] According to the above scheme, the main burners are arranged in N layers, where N≥1.

[0011] The implementation of the mechanized vertical kiln provided with an arch beam of the utility model has the following beneficial effects:

[0012] 1. The utility model is provided with an arch beam, and a combustion chamber is formed under the arch beam, which can provide concentrated and high-intensity heat for the material, and promote the rapid heating and initial reaction of the center part of the material. The negative pressure suction scheme forms a specific airflow circulation pattern in the kiln. The hot flue gas is sucked out from the tropical zone for heat exchange and then participates in the combustion as the central wind. The hot air and hot flue gas in the cooling zone enter the lower burner as combustion-supporting air, making the airflow distribution in the kiln more reasonable and promoting the uniform transfer of heat and the exchange of substances. This airflow circulation pattern helps to form a relatively uniform temperature field in the kiln. From the preheating zone, countercurrent calcination zone, parallel calcination zone to the cooling zone, the temperature of each area can be more stably controlled within an appropriate range, providing good thermal conditions for different calcination stages of the material.

[0013] 2. Negative pressure suction is applied from the cooling zone to extract the hot air and hot flue gas after the material has cooled. This hot air and hot flue gas contain a large amount of waste heat, making them a valuable energy resource. Through rational piping design and suction system, this air is reused as combustion air for the lower burner, improving energy efficiency, reducing energy waste, and lowering production costs. Simultaneously, a portion of the hot flue gas entering the tropical zone is extracted at the upper suction point and exchanged with cold air through a heat exchanger. This cold air then serves as the central air for the ejector, further optimizing air supply and temperature control during the combustion process.

[0014] 3. This utility model can also be equipped with auxiliary burners and a central burner distributed around the kiln wall. The main burner, auxiliary burners, and central burner work together to form a localized high-temperature area near the kiln wall, compensating for the insufficient heat transfer at the edge of the central burner and ensuring uniform heating of the entire material in the kiln. Compared with the traditional single burner design, this combination can more effectively utilize the space in the kiln and improve the uniformity of heat distribution, thereby significantly improving the calcination quality and efficiency of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0016] Figure 1 This is a schematic structural diagram of a mechanized vertical kiln provided with an arch beam according to the present invention;

[0017] Figure 2 It is a structural schematic diagram of another embodiment of the utility model of a mechanized vertical kiln provided with an arch beam. DETAILED DESCRIPTION

[0018] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings.

[0019] like Figure 1 As shown, the mechanized vertical kiln of the present invention includes a kiln body 1, an ejector 5, and a heat exchanger 6. An arch beam 2 is disposed across the interior of the kiln body 1, with both ends of the arch beam 2 fixed to the inner wall of the kiln body 1. A main burner 3 is disposed beneath the arch beam 2, forming a combustion chamber between the arch beam 2 and the inner wall of the kiln body 1. The main burner 3 is fixed to the inner wall of the kiln body 1 and is located within the combustion chamber.

[0020] The interior of the kiln body 1 is divided into a preheating zone, a countercurrent calcining zone, a parallel flow calcining zone and a cooling zone from top to bottom; the preheating zone and the countercurrent calcining zone are located above the arch beam 2, and the parallel flow calcining zone and the cooling zone are located below the arch beam 2; in the preheating zone, the material is gradually heated up by heat exchange with the rising hot air flow; in the countercurrent calcining zone, the material is in countercurrent contact with the hot flue gas generated by the combustion of the main burner 3 to achieve a preliminary calcination reaction; in the parallel flow calcining zone, the material moves in parallel with the downward high-temperature air flow generated by the combustion of the main burner 3 to further complete the calcination process; in the cooling zone, the calcined material is cooled by cold air sucked in by the fan.

[0021] The high-temperature flue gas generated by the preheating zone and countercurrent calcination enters the heat exchanger 6 through the pipeline. The combustion air heated by the heat exchanger 6 enters the combustion chamber through the central air port of the injector 5. The bypass air port of the injector 5 introduces the hot air and hot flue gas after cooling the material.

[0022] like Figure 2 As shown, preferably, a central burner 8m' is provided below the center of the arch beam 2, a central support platform 7 is provided at the lower part of the kiln body 1, and the central burner is provided on the top of the central support platform 7.

[0023] Preferably, one, two or more arch beams 2 are provided, and two or more arch beams 2 are cross-arranged.

[0024] Preferably, the main burners are arranged in N layers, N≥1.

[0025] Preferably, a plurality of auxiliary burners 4 are provided above the arch beam 2, and the auxiliary burners 4 are fixed on the inner wall of the kiln body 1. Both the central burner and the auxiliary burners can independently control combustion parameters, such as fuel flow, air flow and injection speed. The working state of each burner can be flexibly adjusted according to the material state and temperature requirements at different stages in the kiln. In the material preheating stage, the power of the central burner and some auxiliary burners can be appropriately reduced to increase the material temperature in a gentle manner to prevent the material from breaking or having other adverse reactions due to a sudden temperature rise; in the material sintering stage, the power of the central burner and the auxiliary burners in key positions is increased to provide a sufficient high-temperature environment for the material and promote the chemical reaction; in the early stage of the cooling stage, the combustion state of the auxiliary burners can be adjusted to fine-tune the atmosphere and temperature in the kiln to assist the cooling process of the material. This flexible combustion control method is not available in traditional combustion methods, and can better adapt to the calcination process requirements of different materials, thereby improving the flexibility and controllability of production.

[0026] The mechanized vertical kiln of this utility model is constructed by combining a central burner with an auxiliary burner, with a negative pressure suction scheme and a unique thermal system in the kiln. It has significant advantages in improving energy utilization, enhancing product quality, and extending equipment life. It has important patent value and practical application prospects, and provides an innovative solution for the development of mechanized vertical kiln technology.

[0027] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A mechanized vertical kiln provided with an arch beam, characterized in that: The kiln comprises a kiln body, an ejector and a heat exchanger. An arch beam is arranged across the interior of the kiln body, and both ends of the arch beam are fixed to the inner wall of the kiln body. A main burner is arranged below the arch beam and fixed to the inner wall of the kiln body. A combustion chamber is formed between the arch beam and the inner wall of the kiln body, and the main burner is located in the combustion chamber. The interior of the kiln is divided from top to bottom into a preheating zone, a countercurrent calcining zone, a parallel-flow calcining zone, and a cooling zone. The preheating zone and the countercurrent calcining zone are located above the arch beam, while the parallel-flow calcining zone and the cooling zone are located below the arch beam. In the preheating zone, the material gradually heats up through heat exchange with the rising hot air flow. In the countercurrent calcining zone, the material comes into countercurrent contact with the hot flue gas generated by the main burner, achieving a preliminary calcination reaction. In the parallel-flow calcining zone, the material moves in parallel with the downward high-temperature air flow generated by the main burner, further completing the calcination process. In the cooling zone, the calcined material is cooled by cold air drawn in by a fan. The high-temperature flue gas generated by preheating and countercurrent calcination enters the heat exchanger through the pipeline. The combustion air heated by the heat exchanger enters the combustion chamber through the central air port of the injector. The side air port of the injector introduces the hot air and hot flue gas after cooling the material.

2. The mechanized vertical kiln with arch beams according to claim 1, characterized in that: A plurality of auxiliary burners are provided above the arch beam and are fixed on the inner wall of the kiln body.

3. The mechanized vertical kiln with arch beams according to claim 1, characterized in that: A central burner is provided below the center of the arch beam, a central support platform is provided at the lower part of the kiln body, and the central burner is arranged on the top of the central support platform.

4. The mechanized shaft kiln with arch beams according to claim 1, characterized in that: There are one, two or more arch beams, and two or more arch beams are cross-arranged.

5. The mechanized vertical kiln with arch beams according to claim 1, characterized in that: The main burners are arranged in N layers, where N≥1.

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