Totally-closed thermal insulation lime shaft kiln

Abstract

The utility model discloses a totally-enclosed thermal insulation lime shaft kiln which comprises a lime shaft kiln body formed by a refractory brick layer lining, an air cap is arranged on the lower portion of the lime shaft kiln body, a discharging device is arranged at the bottom of the lime shaft kiln body, the lower portion of the air cap is connected with an air supply outlet of an air blower air supply pipeline, and the air blower air supply pipeline is connected with an air blower to achieve air supply. The lime shaft kiln is characterized in that the lime shaft kiln is wrapped by a steel plate shell formed by rolling a fully-closed thick steel plate, and a composite heat preservation material is filled between the steel plate shell and the refractory brick layer to form a heat preservation and insulation layer; an umbrella-shaped distributor is arranged on the upper portion of the lime shaft kiln, an annular air inducing mechanism is arranged on an opening in the upper portion of the umbrella-shaped distributor and connected with an induced draft fan through an induced draft fan air draft pipeline, and a plurality of air inducing holes are symmetrically formed in the bottom face of the annular air inducing mechanism along the center. The lime shaft kiln can achieve the effects of reducing heat energy loss, saving energy, and being efficient in production and scientific and environment-friendly in production.

Description

Technical Field

[0001] The utility model belongs to the technical field of lime kiln design, relates to lime kiln design, and specifically relates to a fully enclosed heat-insulating lime vertical kiln. Background Art

[0002] The current limestone vertical kiln is a traditional limestone burning method, which has the advantages of simple kiln temperature control, high stability of limestone quality, long residence time of limestone in the kiln, high production efficiency, and easy operation, which only requires controlling the kiln mouth and the amount of feed. However, it has the advantages of high energy consumption, large amount of fuel needs to be burned in the production process, and high cost; the vertical kiln flue gas contains a large amount of hydrocarbons, SO2, etc., and a large amount of emissions will cause pollution to the environment.

[0003] The existing lime shaft kiln body basically adopts the structure of a cylinder plus a kiln lining with refractory bricks. This design structure will generate a large amount of heat energy dissipation, waste heat energy, and have high energy consumption costs. At the same time, there are also quality problems such as over-burning or under-burning of products due to uneven heating, as well as the occurrence of kiln agglomeration.

[0004] The existing lime shaft kiln has a height of about 30 meters. The type and quality of limestone, flue gas emission and heat recovery efficiency, and the material and structure of the kiln tube will affect the height of the kiln. The effective height of the kiln, that is, the vertical distance between the discharge port at the bottom of the kiln and the feeding port, is related to the inner diameter, but not in a linear relationship. As the diameter of the shaft kiln increases, the height of the corresponding shaft kiln also needs to be increased. If the height is too high, the fluid resistance is large, and the fan capacity is insufficient, the output and quality are low, and the energy consumption is relatively large. Summary of the invention

[0005] The utility model discloses a fully enclosed heat-insulating lime vertical kiln in view of the deficiencies in the prior art. The utility model aims to provide a lime vertical kiln with higher thermal efficiency and better environmental protection.

[0006] The utility model is realized by the following technical solutions:

[0007] A fully enclosed heat-insulating lime shaft kiln comprises a lime shaft kiln formed by a refractory brick lining, a hood is arranged at the bottom of the lime shaft kiln, a discharge device is arranged at the bottom, the hood is connected to the air outlet of the blower air supply pipeline, and the blower air supply pipeline is connected to the blower to realize air supply; the characteristics are: the lime shaft kiln is covered by a steel plate shell made of a fully enclosed thick steel plate roll, and a composite heat-insulating material is filled between the steel plate shell and the refractory brick layer to form a heat-insulating layer; an umbrella-shaped distributor is arranged at the top of the lime shaft kiln, an annular induced draft mechanism is arranged at the opening above the umbrella-shaped distributor, the annular induced draft mechanism is connected to the induced draft fan through the induced draft fan exhaust pipeline, and a plurality of induced draft holes are symmetrically arranged along the center of the bottom surface of the annular induced draft mechanism.

[0008] Furthermore, the height of the lime shaft kiln is preferably set to 45 meters and the inner diameter is 5.3 meters.

[0009] Aerogel composite insulation material is filled between the Q235 low carbon steel plate shell and the refractory brick layer.

[0010] The utility model is beneficial:

[0011] The utility model lime vertical kiln is covered by a steel plate shell made of fully enclosed thick steel plate rolls, and a composite heat-insulating material is filled between the steel plate shell and the refractory brick layer to form a heat-insulating layer to prevent heat dissipation and effectively utilize the heat energy in the kiln. In addition, the fully enclosed cylinder can effectively prevent the calcining flame from being deformed by the mixed material pressure of the stone and coal above, realize the integration of the kiln body and the fire mouth, and the combustion direction is always upward, ensuring that the flame cannot escape to the outside.

[0012] The utility model increases the height of the kiln body, preferably the kiln body height is 45m, sets the adjustable fan power, and combines with lime calcination to form a protective layer mainly composed of carbon dioxide in the preheating zone of the kiln body. The mixed material below the protective layer can be calcined to form a finished calcium oxide product. The mixed material temperature above the protective layer is relatively low and carbon dioxide participates in the reaction, which can effectively force out the moisture in the mixed material. At the same time, it will not cause the product to be overburned due to the premature formation of calcium oxide, which affects the product quality. The higher kiln body of the utility model lime vertical kiln allows the materials in the kiln to have enough time for material mixing and calcination reaction during the descent process. The main raw material is limestone with a particle size of 58mm. Due to the effect of gravity, it descends faster, avoiding the problem of under-burning of limestone and affecting product quality. The inner diameter of the vertical kiln is 5.3 meters. By increasing the volume of the kiln body, the output per unit cross-sectional area can be increased, thereby achieving the purpose of increasing production capacity.

[0013] The utility model adopts a fixed umbrella-shaped distributor for distributing materials. The distribution can be completed by opening the umbrella mouth by using the middle pull rod. The activity space is small and easy to close. In general, when a vertical kiln calcines raw materials, a cone-shaped raw material pile will appear in the calcination area, with large pieces of materials around and small pieces of materials in the middle. The material layer of the kiln wall is thickened, resulting in ring formation in the inner layer of the kiln wall. The umbrella-shaped distributor makes the limestone and coal ratio more uniform, reduces incomplete combustion, and thus reduces the occurrence of ring formation.

[0014] The utility model provides an annular induced draft mechanism at the opening above the umbrella-shaped distributor of the vertical lime kiln. The annular induced draft mechanism is connected to the induced draft fan through the induced draft fan exhaust pipe. The bottom surface of the annular induced draft mechanism is symmetrically provided with multiple induced draft holes along the center. This design can ensure uniform negative pressure production in the kiln body, and at the same time, the vertical kiln smoke can be extracted and processed through purification equipment, reducing the impact of large-scale emissions on the environment.

[0015] The utility model can realize the effects of reducing heat energy loss, saving energy, efficient production and scientific and environmentally friendly production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1The utility model is a schematic cross-sectional view of a fully enclosed heat-insulating lime vertical kiln.

[0017] In the figure, 1 represents a steel plate shell, 2 represents a thermal insulation layer, 3 represents a refractory brick layer, 4 represents a hood, 5 represents a blower air supply pipeline, 6 represents a blower, 7 represents a discharge device, 8 represents a discharge pipe, 9 represents an umbrella-shaped distributor, 10 represents an annular induced draft mechanism, 11 represents an induced draft fan exhaust pipeline, and 12 represents an induced draft fan. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with specific implementation methods. The specific implementation methods are further descriptions of the principles of the present invention and do not limit the present invention in any way. Technologies identical or similar to the present invention do not exceed the scope of protection of the present invention.

[0019] Combined with the attached pictures.

[0020] As shown in the figure, the fully enclosed heat-insulating lime shaft kiln of the utility model comprises a lime shaft kiln formed by lining a refractory brick layer 3, a hood 4 is arranged at the lower part of the lime shaft kiln, a discharging device 7 is arranged at the bottom, the lower part of the hood 4 is connected to the air outlet of the blower air supply pipeline 5, and the blower air supply pipeline 5 is connected to the blower 6 to realize air supply; the lime shaft kiln is covered by a steel plate shell 1 made of fully enclosed thick steel plate rolls, and a composite heat-insulating material is filled between the steel plate shell 1 and the refractory brick layer 3 to form a heat-insulating layer 2; an umbrella-shaped distributor 9 is arranged at the upper part of the lime shaft kiln, and an annular induced draft mechanism 10 is arranged at the opening above the umbrella-shaped distributor 9, and the annular induced draft mechanism 10 is connected to the induced draft fan 12 through the induced draft fan exhaust pipeline 11, and a plurality of induced draft holes are symmetrically arranged along the center of the bottom surface of the annular induced draft mechanism 10.

[0021] The utility model discloses a fully enclosed heat-insulating lime vertical kiln. The outer shell of the cylinder adopts a fully enclosed steel plate shell 1 with a tight structure, which is used to isolate the external air and ensure the strength of the kiln body. The middle heat-insulating layer 2 is filled with a composite heat-insulating material mainly composed of aerogel. This heat-insulating material is a solid material with the lowest thermal conductivity and the lowest density, which can effectively seal the temperature in the kiln body and achieve an outer wall temperature of about 25 degrees, which is one tenth of the outer wall temperature of a conventional lime kiln. At the same time, since the steel plate shell 1 effectively isolates the air, the flame can be prevented from burning through the heat-insulating layer 2.

[0022] The fully enclosed heat-insulating lime vertical kiln of the utility model can effectively prevent the calcining flame from being deformed by the mixed material pressure of stones and coal above through the fully enclosed steel cylinder structure, realizes the integration of the kiln body and the fire mouth, and the combustion direction is always upward, ensuring that the flame cannot escape to the outside.

[0023] When the fixed umbrella-type cloth distributing device 9 is used for distributing cloth, the cloth can be distributed by opening the umbrella mouth with the middle pull rod, and the movable space is small and easy to be closed.

[0024] In order to ensure sufficient combustion air, high-power fans are installed at the fire mouth and the kiln top. The fire mouth blower 6 blows in fresh air, and the kiln top draft fan 12 draws air to form a negative pressure to establish air circulation and ensure the direction of flame combustion.

[0025] An annular air duct 10 is arranged on the kiln top cover, and 8 holes are evenly and symmetrically opened in the annular air duct 10, leading to the kiln body, so as to ensure uniform negative pressure in the kiln body.

[0026] The utility model adopts a fully enclosed heat-insulating lime vertical kiln to achieve the following better design and operation effects by adopting a fully enclosed production mode.

[0027] The utility model uses Q235 steel plate for the outer wall of the limestone vertical kiln, which has good plasticity, toughness and welding performance. The middle thermal insulation layer selects high-temperature resistant aerogel to reduce heat loss and ensure that the limestone kiln can operate stably for a long time.

[0028] The utility model increases the height of the kiln body, and the kiln body height in this example is preferably 45m; combined with the optimized design of height and diameter, the limestone raw material of the lime vertical kiln of the utility model mainly uses limestone with a block size of 58mm. Due to the effect of gravity, it descends faster. Properly increasing the height of the kiln body can also ensure sufficient reaction time and sufficient material mixing, avoid the problem of under-burning of limestone and thus affecting product quality, ensure product quality, and increase production capacity under the same energy consumption.

[0029] Since the combustion of raw materials in the vertical kiln requires a large amount of air, the smoke generated also needs to be discharged in time. The use of high-power centrifugal fans for air blowing has large air volume, high flow rate, high heat exchange intensity, high output and quality. Increasing the air volume in the kiln is also very beneficial to the production of the vertical kiln.

[0030] The fixed umbrella-type distributor distributes the materials evenly, improves the reaction efficiency after mixing, and speeds up the production and discharge of lime.

Claims

1. A fully enclosed heat-insulating lime shaft kiln, comprising a lime shaft kiln lined with a refractory brick layer, a hood is arranged at the bottom of the lime shaft kiln, a discharge device is arranged at the bottom, the lower part of the hood is connected to the air outlet of the blower air supply pipeline, and the blower air supply pipeline is connected to the blower to realize air supply; characterized in that: The lime shaft kiln is covered by a steel plate shell made of fully enclosed thick steel plate rolls, and a composite thermal insulation material is filled between the steel plate shell and the refractory brick layer to form a thermal insulation layer; an umbrella-shaped distributor is arranged on the upper part of the lime shaft kiln, and an annular induced draft mechanism is arranged in the opening above the umbrella-shaped distributor. The annular induced draft mechanism is connected to the induced draft fan through an induced draft fan exhaust duct, and a plurality of induced draft holes are symmetrically arranged along the center of the bottom surface of the annular induced draft mechanism.

2. The fully enclosed heat-insulating lime shaft kiln according to claim 1 is characterized in that: The vertical lime kiln has a height of 45 meters and an inner diameter of 5.3 meters.

3. The fully enclosed heat-insulating lime shaft kiln according to claim 1 is characterized in that: Aerogel composite insulation material is filled between the Q235 low carbon steel plate shell and the refractory brick layer.

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