阅读说明：本技术 三膛竖窑及煅烧方法 (Three-chamber shaft kiln and calcination method ) 是由 田辉 段国建 刘畅 全强 孟凯彪 王艳民 王得刚 岳杰 李照麟 于 2019-12-13 设计创作，主要内容包括：本发明提供了一种三膛竖窑及煅烧方法,三膛竖窑包括三个结构相同的立式竖窑,三个立式竖窑呈中心对称分布,且相邻两个立式竖窑之间均设置有连接通道。设置三个立式竖窑,可以使多个立式竖窑同时燃烧,能够显著提高石灰窑的产量,同时将相邻两个立式竖窑之间设置连接通道,可以使每个立式竖窑均有两个连接通道,使连接通道的总面积增加,烟气通过畅通,窑内热能使用率大大提高,降低了石灰窑的能源耗能比。(The invention provides a three-chamber shaft kiln and a calcining method, wherein the three-chamber shaft kiln comprises three vertical shaft kilns with the same structure, the three vertical shaft kilns are distributed in a centrosymmetric manner, and a connecting channel is arranged between every two adjacent vertical shaft kilns. Set up three vertical shaft kiln, can make a plurality of vertical shaft kiln simultaneous combustion, can show the output that improves the lime kiln, will set up interface channel between two adjacent vertical shaft kilns simultaneously, can make every vertical shaft kiln all have two interface channel, make interface channel's total area increase, the flue gas passes through unblocked, the heat energy rate of utilization improves greatly in the kiln, has reduced the energy power consumption ratio of lime kiln.)

1. The three-chamber shaft kiln is characterized by comprising three vertical shaft kilns with the same structure, wherein the three vertical shaft kilns are distributed in a central symmetry manner, and a connecting channel (4) is arranged between every two adjacent vertical shaft kilns.

2. The shaft kiln according to claim 1, wherein a combustion air duct, a fuel duct and a material inlet are provided in the top of each of said vertical shaft kilns.

3. The shaft kiln as claimed in claim 1, wherein a material inlet is provided at the top of each of the vertical shaft kilns, and a combustion air duct and a fuel duct are provided at the bottom of the side wall of each of the vertical shaft kilns.

4. The three-bore shaft kiln of claim 1, wherein each of said vertical shaft kilns is circular in cross section.

5. Three-chamber shaft kiln according to claim 1, characterized in that the longitudinal section of the connecting channel (4) is of an isosceles trapezium structure, and the length of the top surface of the isosceles trapezium is greater than the length of the bottom surface of the isosceles trapezium.

6. Three shaft kiln according to claim 1, characterised in that three of said vertical shafts comprise a first shaft (1), a second shaft (2) and a third shaft (3),

the first shaft kiln (1) and the second shaft kiln (2) are both combustion kilns, and the third shaft kiln (3) is a heat storage kiln;

or the first shaft kiln (1) and the second shaft kiln (2) are heat-storage kilns, and the third shaft kiln (3) is a combustion kiln.

7. A three-chamber shaft kiln calcining method is characterized in that three vertical shaft kilns comprise a first shaft kiln (1), a second shaft kiln (2) and a third shaft kiln (3), and the three-chamber shaft kiln calcining method comprises the following steps:

step 1, taking the first shaft kiln (1) and the second shaft kiln (2) as combustion kilns, and taking the third shaft kiln (3) as a heat storage kiln;

and 2, enabling combustion waste gas in the first shaft kiln (1) and the second shaft kiln (2) to enter the third shaft kiln (3) through a connecting channel (4) and preheating materials.

8. A three-chamber shaft kiln calcining method is characterized in that three vertical shaft kilns comprise a first shaft kiln (1), a second shaft kiln (2) and a third shaft kiln (3), and the three-chamber shaft kiln calcining method comprises the following steps:

step 1, taking the first shaft kiln (1) and the second shaft kiln (2) as heat storage kilns, and taking the third shaft kiln (3) as a combustion kiln;

and 2, enabling combustion waste gas in the third shaft kiln (3) to enter the first shaft kiln (1) and the second shaft kiln (2) through a connecting channel (4) and preheating materials.

9. The three-chamber shaft kiln calcination method according to claim 7 or 8, wherein the top of the combustion kiln is provided with a combustion air pipeline, a fuel pipeline and a material inlet, and the step 1 comprises:

injecting combustion air from the top of the side wall of the combustion kiln through the combustion air pipeline;

injecting fuel from the top of the side wall of the combustion kiln through the fuel pipeline;

injecting material from the top of the combustion kiln through the material inlet.

10. The three-chamber shaft kiln calcination method according to claim 7 or 8, wherein the top of the combustion kiln is provided with a material inlet, the bottom of the side wall of the combustion kiln is provided with a combustion air pipeline and a fuel pipeline, and the step 1 comprises the following steps:

injecting combustion air from the bottom of the side wall of the combustion kiln through the combustion air pipeline;

injecting fuel from the bottom of the side wall of the combustion kiln through the fuel pipeline;

injecting material from the top of the combustion kiln through the material inlet.

Technical Field

The invention relates to the technical field of industrial kilns, in particular to a three-hearth shaft kiln and a calcination method.

Background

At present, the domestic popular kiln types of the main limekilns include a shaft kiln and a rotary kiln. Wherein, the rotary kiln is the kiln type which is most widely applied and has relatively mature technology at present. However, the rotary kiln occupies too large area, the heat energy loss is very serious, and the green economic policy advocated by the state is not facilitated, so the lime shaft kiln is gradually widely applied.

The double-chamber lime shaft kiln is characterized by that it possesses two parallel chambers, and is connected by means of connecting channel in the middle of lower portion of kiln body, and its calcining process possesses two main characteristics: parallel flow and heat accumulation. Co-current flow is the downward flow of combustion products in parallel with the limestone as the limestone is calcined. This facilitates the calcination of high quality active lime. The heat accumulation is that the high temperature waste gas which is the product of the combustion chamber enters the non-combustion chamber through a connecting channel at the lower part of the two kiln chambers. The high-temperature waste gas in the non-combustion chamber flows upwards to preheat limestone in the preheating zone to a higher temperature, and heat is accumulated. Meanwhile, the high-temperature waste gas is discharged out of the kiln chamber after being reduced to a very low temperature. The working principle fully utilizes the waste heat of the waste gas and has high heat efficiency. However, the double-chamber lime shaft kiln has the defect that the channel is easy to block, the yield is improved by enlarging the kiln chamber, the limestone calcination is not uniform, and the quality of lime cannot be ensured.

Disclosure of Invention

The invention provides a three-chamber shaft kiln and a calcining method, which aim to improve the yield of a lime shaft kiln.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a three thorax shaft kilns, includes the same vertical shaft kilns of three structure, and three vertical shaft kilns are central symmetry and distribute, and all are provided with between two adjacent vertical shaft kilns and connect the passageway.

Furthermore, a combustion-supporting air pipeline, a fuel pipeline and a material inlet are arranged at the top of each vertical shaft kiln.

Furthermore, the top of each vertical shaft kiln is provided with a material inlet, and the bottom of the side wall of each vertical shaft kiln is provided with a combustion air pipeline and a fuel pipeline.

Further, each vertical shaft kiln is circular in cross section.

Furthermore, the longitudinal section of the connecting channel is of an isosceles trapezoid structure, and the length of the top surface of the isosceles trapezoid is greater than that of the bottom surface of the isosceles trapezoid.

Further, the three vertical shaft kilns comprise a first shaft kiln, a second shaft kiln and a third shaft kiln, wherein the first shaft kiln and the second shaft kiln are both combustion kilns, and the third shaft kiln is a heat storage kiln; or the first shaft kiln and the second shaft kiln are both heat-storage kilns, and the third shaft kiln is a combustion kiln.

The invention also provides a three-chamber shaft kiln calcining method, wherein the three vertical shaft kilns comprise a first shaft kiln, a second shaft kiln and a third shaft kiln, and the three-chamber shaft kiln calcining method comprises the following steps: step 1, taking the first shaft kiln and the second shaft kiln as combustion kilns, and taking the third shaft kiln as a heat storage kiln; and 2, enabling combustion waste gas in the first shaft kiln and the second shaft kiln to enter a third shaft kiln through a connecting channel and preheating materials.

Further, the three-chamber shaft kiln calcining method comprises the following steps: step 1, taking the first shaft kiln and the second shaft kiln as heat storage kilns, and taking the third shaft kiln as a combustion kiln; and 2, enabling combustion waste gas in the third shaft kiln to enter the first shaft kiln and the second shaft kiln through the connecting channel and preheating materials.

Further, the top of the combustion kiln is provided with a combustion air pipeline, a fuel pipeline and a material inlet, and the step 1 comprises the following steps: injecting combustion-supporting air from the top of the side wall of the combustion kiln through a combustion-supporting air pipeline; injecting fuel from the top of the side wall of the combustion kiln through a fuel pipeline; injecting the material from the top of the combustion kiln through the material inlet.

Further, the top of burning kiln all is provided with the material entry, and the lateral wall bottom of burning kiln all is provided with combustion-supporting air pipeline and fuel conduit, and step 1 includes: injecting combustion-supporting air from the bottom of the side wall of the combustion kiln through a combustion-supporting air pipeline; injecting fuel from the bottom of the side wall of the combustion kiln through a fuel pipeline; injecting the material from the top of the combustion kiln through the material inlet.

The lime kiln has the advantages that the three vertical shaft kilns are arranged, so that a plurality of vertical shaft kilns can burn simultaneously, the yield of the lime kiln can be obviously improved, the connecting channel is arranged between every two adjacent vertical shaft kilns, each vertical shaft kiln can be provided with two connecting channels, the total area of the connecting channels is increased, the smoke gas passes smoothly, the utilization rate of heat energy in the kilns is greatly improved, and the energy consumption ratio of the lime kiln is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic top view of an embodiment of the present invention;

FIG. 2 is a schematic sectional view of two adjacent vertical shaft kilns in the embodiment of the invention.

Reference numbers in the figures: 1. a first shaft kiln; 2. a second shaft kiln; 3. a third shaft kiln; 4. a connecting channel.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 and 2, an embodiment of the present invention provides a three-chamber shaft kiln, which includes three vertical shaft kilns with the same structure, the three vertical shaft kilns are distributed in a central symmetry manner, and a connecting channel 4 is arranged between two adjacent vertical shaft kilns.

Set up three vertical shaft kiln, can make a plurality of vertical shaft kiln simultaneous combustion, can show the output that improves the limekiln, will set up interface channel between two adjacent vertical shaft kilns simultaneously, can make every vertical shaft kiln all have two interface channel 4, make interface channel 4's total area increase, the flue gas passes through unblocked, the heat energy rate of utilization improves greatly in the kiln, has reduced the energy power consumption ratio of limekiln.

It should be noted that the permeability of connecting channel 4 is an important factor affecting production. Two important factors affecting the permeability of the connecting channel 4 are the gas flow and the channel temperature. The more flue gas is allowed to pass through the connecting channel 4 connecting the two shaft kilns, the more ideal the operating conditions of the shaft kilns are. However, from the point of view of the lime kiln structure, when the shaft kiln is bigger and the wall is longer, the shaft kiln is in danger of deforming due to thermal expansion.

In the embodiment of the invention, each shaft kiln is provided with two connecting channels 4, the amount of smoke allowed to pass through the connecting channels 4 is increased, and the full utilization of heat can be realized to the maximum extent. As the ventilation area is increased, the oxygen supply is obviously improved, the fuel can be fully combusted, and the yield is improved. Obviously, the larger the area of the connecting channel 4 is, the higher the flue gas utilization rate is, the more the pre-decomposition amount is, and the lower the energy consumption is. In addition, the design of the multiple connecting channels 4 can enable the flue gas to enter the non-combustion chamber along the nearest connecting channel 4, and compared with a single channel, the air flow distribution is more uniform.

The top of each vertical shaft kiln is provided with a combustion-supporting air pipeline, a fuel pipeline and a material inlet. The combustion-supporting air, the fuel and the materials all flow downwards from the upper part of a calcining zone (a shaft kiln is divided into a preheating zone, a calcining zone and a cooling zone from top to bottom, the functions of the preheating zone, the calcining zone and the cooling zone are respectively to preheat limestone and to cool calcined lime), the flow directions of the three are the same, the materials realize gradient combustion, and therefore the overburning phenomenon is avoided, and the process is called parallel-flow calcining.

In a different embodiment, a material inlet is arranged at the top of each vertical shaft kiln, and a combustion air pipeline and a fuel pipeline are arranged at the bottom of the side wall of each vertical shaft kiln. The method is called counter-current calcination, and the counter-current calcination can save fuel and realize continuous production.

The cross section of each vertical shaft kiln is circular. Circular section kilns are best viewed in terms of uniformity of bulk material distribution, as they enable equal probability of material distribution in all directions. When the shaft kiln is of rectangular or oval cross-section, large lumps of batch material may always collect at the corners of the kiln remote from the centerline of the shaft kiln, and uneven distribution of lumps may cause a redistribution of gas flow.

The vertical section of the shaft kiln is in a straight cylinder shape. Its advantages are simple and stable structure, uniform sinking and smooth movement of material, no strengthening of kiln wall effect, convenient building, small surface area of kiln volume, less heat loss and less consumption of refractory material.

As shown in fig. 2, the longitudinal section of the connecting channel 4 is an isosceles trapezoid structure, and the length of the top surface of the isosceles trapezoid is greater than the length of the bottom surface of the isosceles trapezoid. Compared with an annular channel, the connecting channel 4 in the embodiment is short and straight, so that alkaline steam in the shaft kiln can rapidly and directly enter another shaft kiln from the short channel, the steam cannot be condensed on quicklime, and any incrustation phenomenon generated on the connecting channel 4 is avoided.

Preferably, the three vertical shaft kilns comprise a first shaft kiln 1, a second shaft kiln 2 and a third shaft kiln 3, the first shaft kiln 1 and the second shaft kiln 2 are combustion kilns, the third shaft kiln 3 is a heat accumulation kiln or the first shaft kiln 1 and the second shaft kiln 2 are heat accumulation kilns, and the third shaft kiln 3 is a combustion kiln.

Taking cocurrent calcination as an example, three shaft kilns are respectively used as a combustion chamber and a non-combustion chamber (one for two combustion or two for one combustion). The combustion air, the fuel and the materials all flow downwards from the upper part of the calcining zone, the flow directions of the three are the same, and the materials realize gradient combustion, so that the over-combustion phenomenon is avoided. The flue gas generated by calcination enters the non-combustion chamber through the connecting channel to preheat the materials in the preheating zone, so that the heat can be fully recovered.

The embodiment of the invention also has the following advantages: 1. the heat utilization rate is high: high-temperature waste gas is discharged from the combustion kiln, heat is transferred to limestone after long-time heat exchange, the temperature of the limestone is increased, the temperature of the waste gas is reduced, heat energy is effectively utilized, and therefore the purpose of energy conservation is achieved. 2. The environmental protection effect is good: the temperature and the dust content of the waste gas discharged by the three-chamber shaft kiln are lower, the waste gas purification treatment measures are easy to take, and the environmental pollution is favorably reduced.

The invention also provides a three-chamber shaft kiln calcining method, wherein the three vertical shaft kilns comprise a first shaft kiln 1, a second shaft kiln 2 and a third shaft kiln 3, and the three-chamber shaft kiln calcining method comprises the following steps:

step 1, taking a first shaft kiln 1 and a second shaft kiln 2 as combustion kilns, and taking a third shaft kiln 3 as a heat storage kiln;

and 2, enabling combustion waste gas in the first shaft kiln 1 and the second shaft kiln 2 to enter a third shaft kiln 3 through a connecting channel 4 and preheating materials.

Taking cocurrent calcination as an example, the top of a combustion kiln is provided with a combustion air pipeline, a fuel pipeline and a material inlet, and the step 1 comprises the following steps:

injecting combustion-supporting air from the top of the side wall of the combustion kiln through a combustion-supporting air pipeline;

injecting fuel from the top of the side wall of the combustion kiln through a fuel pipeline;

injecting the material from the top of the combustion kiln through the material inlet.

Taking countercurrent calcination as an example, the top of the combustion kiln is provided with a material inlet, the bottom of the side wall of the combustion kiln is provided with a combustion air pipeline and a fuel pipeline, and the step 1 comprises the following steps:

injecting combustion-supporting air from the bottom of the side wall of the combustion kiln through a combustion-supporting air pipeline;

injecting fuel from the bottom of the side wall of the combustion kiln through a fuel pipeline;

injecting the material from the top of the combustion kiln through the material inlet.

The embodiment of the invention also provides a three-chamber shaft kiln calcining method, wherein the three vertical shaft kilns comprise a first shaft kiln 1, a second shaft kiln 2 and a third shaft kiln 3, and the three-chamber shaft kiln calcining method comprises the following steps:

step 1, taking a first shaft kiln 1 and a second shaft kiln 2 as heat storage kilns, and taking a third shaft kiln 3 as a combustion kiln;

and 2, enabling combustion waste gas in the third shaft kiln 3 to enter the first shaft kiln 1 and the second shaft kiln 2 through the connecting channel 4 and preheating materials.

Except for the above distinguishing technical features, other technical features are the same as or similar to those of the previous embodiment, and are not repeated herein.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

1. in the embodiment, each shaft kiln is provided with two connecting channels, so that the total area of the channels is increased, the smoke gas passes through smoothly, the heat energy utilization rate in the kiln is greatly improved, and the energy consumption ratio of the lime kiln is reduced.

2. The gas flow bias flow is small, the heat transmission is uniform, no dead angle exists in the calcination process, the channel does not have a blocking phenomenon, and the calcination quality is improved.

3. The embodiment can greatly improve the yield and obviously improve the product quality.

4. The embodiment has the advantages of compact structure, simple and convenient operation, strong safety, high automation degree, low investment and the like.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, so that the invention is intended to cover all modifications and equivalents of the embodiments described herein. In addition, the technical features, the technical schemes and the technical schemes can be freely combined and used.