Flue gas treatment system for regeneration drying cylinder of asphalt mixing station

Abstract

The invention relates to a flue gas treatment system for a regeneration drying cylinder of an asphalt mixing station. The flue gas treatment system comprises the regeneration drying cylinder, a primary drying cylinder, a regeneration relay fan, a primary relay fan and a dust remover, regeneration flue gas at the tail end of the regeneration drying cylinder enters the dust remover through a pipeline, the regeneration flue gas subjected to dust removal through the dust remover is divided into two paths, one path of regeneration flue gas is guided into the front end of the regeneration drying cylinder through the regeneration relay fan, and the other path of regeneration flue gas is guided into the tail end of the regeneration drying cylinder through the regeneration relay fan. And the other path of regenerated flue gas is guided into the feeding end of the primary drying cylinder through the primary relay fan. Through the steps of multi-stage sedimentation, incineration and purification, harmful substances in the flue gas are effectively removed, the treatment efficiency is improved, the treated dust particles can be recycled in an asphalt formula, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas treatment, and in particular to a flue gas treatment system for a regenerated drying drum of an asphalt mixing plant. Background Art

[0002] In asphalt mixing plants, the regeneration dryer is used to heat the RAP milling material to restore its asphalt properties so that it can meet the quality standards for re-use. However, a large amount of flue gas containing harmful substances will be generated during the heating process of the RAP milling material, which will pollute the environment if directly discharged. Traditional flue gas treatment methods often have problems such as low treatment efficiency, high cost, and inability to effectively recycle. Summary of the invention

[0003] The purpose of the present invention is to provide a flue gas treatment system for a regenerated drying drum of an asphalt mixing plant in order to overcome at least one of the defects of the prior art.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A flue gas treatment system for a regeneration drying drum of an asphalt mixing plant, comprising a regeneration drying drum, a primary drying drum, a regeneration relay fan, a primary relay fan and a dust collector;

[0006] The regeneration flue gas at the end of the regeneration drying cylinder enters the dust collector through a pipeline. The regeneration flue gas after dust removal by the dust collector is divided into two paths. One path of regeneration flue gas is introduced into the front end of the regeneration drying cylinder through the regeneration relay fan, and the other path of regeneration flue gas is introduced into the feed end of the primary drying cylinder through the primary relay fan.

[0007] Furthermore, the regeneration flue gas introduced into the regeneration drying cylinder through the regeneration relay fan accounts for 60% to 70% of the regeneration flue gas dedusted by the dust collector.

[0008] Furthermore, the regeneration flue gas guided by the regeneration relay fan is introduced into the regeneration burner flame zone of the regeneration drying cylinder.

[0009] Furthermore, the regeneration flue gas introduced into the primary drying cylinder via the primary relay fan accounts for 30% to 40% of the regeneration flue gas dedusted by the dust collector.

[0010] Furthermore, the regenerated flue gas guided by the primary relay fan is introduced into the primary burner flame zone of the primary drying cylinder.

[0011] Furthermore, the dust collector is a gravity dust removal box. Preferably, the gravity dust removal box is a multi-stage gravity dust removal box.

[0012] Furthermore, the dust collector removes coarse particles having a particle size greater than 75 microns.

[0013] Furthermore, the temperature inside the regeneration drying cylinder is controlled at 800°C to 1200°C.

[0014] Furthermore, the flue gas at the end of the primary drying cylinder enters the dust collector through a pipeline.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] (1) Efficient treatment: The present invention effectively removes harmful substances in flue gas through multi-stage sedimentation, incineration and purification steps, thereby improving treatment efficiency.

[0017] (2) Cost saving: The present invention recycles the treated dust particles into the asphalt formulation, thereby reducing production costs.

[0018] (3) Environmental protection and energy saving: The present invention reduces the pollution of flue gas emissions to the environment and realizes the recycling of resources, which is in line with the concept of green and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the flue gas treatment system of the regeneration drying drum of the asphalt mixing plant in the embodiment;

[0020] The numbers in the figure are as follows: 1-regeneration drying cylinder; 2-dust collector; 3-primary drying cylinder; 4-primary relay fan; 5-regeneration relay fan. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0022] Example

[0023] This embodiment provides a flue gas treatment system for the regeneration drying drum of an asphalt mixing plant. The specific process is shown in Figure 1 , including a regeneration drying cylinder 1, a primary drying cylinder 3, a regeneration relay fan 5, a primary relay fan 4 and a dust collector 2;

[0024] The regenerated flue gas at the end of the regeneration drying cylinder 1 enters the dust collector 2 through a pipeline. The regenerated flue gas after dust removal by the dust collector 2 is divided into two paths. One path of regeneration flue gas is introduced into the front end of the regeneration drying cylinder 1 through the regeneration relay fan 5, and the other path of regeneration flue gas is introduced into the feed end of the primary drying cylinder 3 through the primary relay fan 4.

[0025] In this embodiment, the regeneration flue gas introduced into the regeneration drying cylinder 1 through the regeneration relay fan 5 accounts for 60% to 70% of the regeneration flue gas removed by the dust collector 2; the regeneration flue gas guided by the regeneration relay fan 5 is introduced into the regeneration burner flame zone of the regeneration drying cylinder 1.

[0026] In this embodiment, the regenerated flue gas introduced into the primary drying cylinder 3 through the primary relay fan 4 accounts for 30% to 40% of the regenerated flue gas removed by the dust collector 2; the regenerated flue gas guided by the primary relay fan 4 is introduced into the primary burner flame zone of the primary drying cylinder 3.

[0027] In this embodiment, the dust collector 2 is a gravity dust box. The dust collector 2 removes coarse particles with a particle size greater than 75 microns. These particles themselves come from RAP milling materials, and their composition has a certain correlation with the asphalt mixture. Adding them back into the formula can reduce the use of new raw materials and reduce production costs. At the same time, from an environmental protection perspective, this also reduces waste emissions and is in line with the concept of a circular economy. For example, these settled particles may contain a certain amount of mineral aggregates, which can enhance the stability and other properties of the mixture after being re-added to the asphalt mixture formula.

[0028] Preferably, the gravity dust box is a multi-stage gravity dust box, specifically a two-stage gravity dust box. For dust particles with a particle size greater than 100 μm, in the first-stage sedimentation box, when the gas flow rate is reduced to a certain level, they can settle down quickly. After the first-stage sedimentation, although most of the large dust particles have been removed, the gas still contains some smaller dust particles. These gases then enter the second-stage sedimentation box, further reducing the gas flow rate, so that the remaining smaller dust particles also have enough time and space to settle under the action of gravity. The second-stage sedimentation box can have a better sedimentation effect on dust with a particle size of about 50 to 100 μm.

[0029] In this embodiment, the temperature inside the regeneration drying cylinder 1 is controlled at 800° C. to 1200° C. to burn harmful substances in the flue gas at high temperature.

[0030] In this embodiment, the flue gas at the end of the primary drying cylinder 3 enters the dust collector 2 through a pipeline. On the one hand, after the flue gas is burned at high temperature, the harmful substances therein are effectively decomposed. On the other hand, the stone dust in the primary drying cylinder 3 generates flue gas that collides, intercepts, adsorbs and entrains the asphalt flue gas. The collision refers to the collision between the asphalt flue gas and the dust particles. The interception is used to collect small particles in the range of 1-3μm, and the Brownian diffusion principle is used to collect micron-sized particles to reduce harmful substances in the asphalt flue gas.

[0031] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An asphalt mixing plant regeneration drying drum flue gas treatment system, characterized in that: It comprises a regeneration drying cylinder (1), a primary drying cylinder (3), a regeneration relay fan (5), a primary relay fan (4) and a dust collector (2); The regeneration flue gas at the end of the regeneration drying cylinder (1) enters the dust collector (2) through a pipeline. The regeneration flue gas after dust removal by the dust collector (2) is divided into two paths. One path of the regeneration flue gas is introduced into the front end of the regeneration drying cylinder (1) through the regeneration relay fan (5), and the other path of the regeneration flue gas is introduced into the feed end of the primary drying cylinder (3) through the primary relay fan (4).

2. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1 is characterized in that: The regeneration flue gas introduced into the regeneration drying cylinder (1) via the regeneration relay fan (5) accounts for 60% to 70% of the regeneration flue gas dedusted by the dust collector (2).

3. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1 is characterized in that: The regeneration flue gas guided by the regeneration relay fan (5) is introduced into the regeneration burner flame zone of the regeneration drying cylinder (1).

4. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The regeneration flue gas introduced into the primary drying cylinder (3) via the primary relay fan (4) accounts for 30% to 40% of the regeneration flue gas dedusted by the dust collector (2).

5. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The regenerated flue gas guided by the primary relay fan (4) is introduced into the primary burner flame zone of the primary drying cylinder (3).

6. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The dust collector (2) is a gravity dust removal box.

7. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 6, characterized in that: The gravity dust removal box is a multi-stage gravity dust removal box.

8. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The dust collector (2) removes coarse particles with a particle size greater than 75 microns.

9. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The temperature inside the regeneration drying cylinder (1) is controlled at 800°C to 1200°C.

10. The asphalt mixing plant regeneration drying drum flue gas treatment system according to claim 1, characterized in that: The flue gas at the end of the primary drying cylinder (3) enters the dust collector (2) through a pipeline.

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