A reground material drying heating apparatus and method

Abstract

The present application relates to aggregate recycling equipment technical field, especially relates to a kind of regenerative material drying heating equipment and method.The equipment includes drying drum, hearth, burner, coarse material conveying device, fine material conveying device, the fine material conveying device includes fine material bin, vane feeder, gas material mixing pipe, fan, screw conveyor, the gas material mixing pipe is equipped with air inlet, gas material outlet, fine material inlet, the screw conveyor is arranged in hearth along hearth inner wall, screw conveyor import end is connected with the gas material outlet of gas material mixing pipe, export end extends to discharge ring inside.Only one drying drum is used to realize the separate heating of waste asphalt coarse material and fine material, reduce the equipment floor area, the dust generated by conveying fine material is mostly retained in drying drum and discharge ring, reduce the working load of dust removal device, while improve the utilization rate of fine powder in fine material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aggregate recycling equipment, and particularly relates to a recycled material drying and heating device and method. BACKGROUND

[0002] The asphalt mixture hot recycling technology is a technology for recycling waste asphalt mixture. The existing plant-mixed hot recycling technology generally sends cold waste asphalt mixture into a drying and heating system for treatment, and then mixes the treated waste asphalt mixture with a certain proportion of virgin aggregate and asphalt to finally produce qualified asphalt mixture products. Since the fine materials in the waste asphalt are more easily heated than the coarse materials under the same heating environment, and the fine materials contain more asphalt, over-heating of the fine materials will cause asphalt aging and reduce the quality of the waste asphalt mixture, thereby affecting the quality of the final product.

[0003] To solve the above problems, the existing technology generally adopts a method of separately heating the coarse materials and the fine materials of the waste asphalt. For example, a high-reference plant-mixed hot recycling device disclosed in a Chinese patent with the authorization announcement number CN 111851207U sets a first recycling drying drum and a second recycling drying drum to separately heat the coarse materials and the fine materials of the waste asphalt. Although this method can avoid over-heating of the fine materials, it needs to set two drying drums, which occupies a large area. When the fine materials are separately put into a drying drum, a large amount of dust will be generated during the feeding process. Although the dust can be absorbed by a dust removal system, the dust removal system is easily blocked and damaged due to the increased working load. SUMMARY

[0004] To overcome the deficiencies in the prior art, the present application provides a recycled material drying and heating device and method which separately dries and heats the fine materials and the coarse materials by using one drying drum.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows: a recycled material drying and heating device, comprising a drying drum, a hearth, a burner, a coarse material conveying device, wherein one end of the drying drum is provided with a coarse material inlet, and the other end is provided with a discharging ring; one end of the hearth is connected to the discharging ring, and the other end is provided with the burner; the coarse material conveying device is connected to the coarse material inlet of the drying drum; and the device is characterized in that it further comprises a fine material conveying device, wherein the fine material conveying device comprises a fine material bin, an impeller feeder, a gas-material mixing pipe, a fan and a spiral conveying pipe; the gas-material mixing pipe is horizontally arranged, and one end is provided with an air inlet and the other end is provided with a gas-material outlet; an upwardly opened fine material inlet is arranged on the outer wall of the gas-material mixing pipe between the air inlet and the gas-material outlet; the fan is connected to the air inlet; the lower end of the fine material bin is connected to the fine material inlet through the impeller feeder; and the spiral conveying pipe is arranged in the hearth along the inner wall of the hearth, the inlet end of the spiral conveying pipe is connected to the gas-material outlet of the gas-material mixing pipe, and the outlet end extends into the discharging ring.

[0006] Further, the outlet end of the spiral conveying pipe is bent downward, and the horizontal position of the outlet end is higher than the outlet position of the burner flame.

[0007] Further, the inner wall of the furnace is provided with a heat insulation cotton layer, and the spiral conveying pipe passes through the heat insulation cotton layer.

[0008] Further, the spiral conveying pipe is a seamless spiral steel pipe.

[0009] Further, the inner wall of the spiral conveying pipe is coated with an anti-sticking coating.

[0010] Further, the gas-material mixing pipe is a Venturi tube.

[0011] Further, the dust removal device is further provided, and the dust removal device comprises a negative pressure cover arranged at the coarse material inlet of the drying drum.

[0012] Further, the dust removal device comprises a first induced draft fan and a second induced draft fan, the suction ends of the first induced draft fan and the second induced draft fan are connected to the negative pressure cover, the gas outlet end of the first induced draft fan is connected to the dust collector, and the gas outlet end of the second induced draft fan is connected to one end of the furnace provided with the burner and enters the furnace.

[0013] A method for drying and heating regenerated materials, characterized in that the method comprises the following steps based on any one of the above-mentioned regenerated material drying and heating devices:

[0014] Step one, waste asphalt is classified into coarse materials and fine materials;

[0015] Step two, the coarse materials are sent into the drying drum through the coarse material inlet, and then reach the discharge ring at the other end of the drying drum, and the coarse materials are heated by the hot gas generated by the burner during the process of passing through the drying drum; the fine materials are sent into the gas-material mixing pipe through the impeller feeder at a set feeding speed through the fine material inlet, the high-pressure gas is sent into the gas-material mixing pipe through the gas inlet at one end of the gas-material mixing pipe, the high-pressure gas wraps the fine materials and sends the fine materials out of the gas-material outlet to the spiral conveying pipe, the spiral conveying pipe spirally surrounds the inner wall of the furnace, the flame and the hot gas of the burner heat the spiral conveying pipe, the fine materials are heated during the process of passing through the spiral conveying pipe, and the fine materials reach the discharge ring after being sent out of the spiral conveying pipe.

[0016] Step three, the fine materials and the coarse materials are mixed in the discharge ring and then sent out.

[0017] From the above description of the present application, compared with the prior art, the present application provides a regenerated material drying and heating equipment and method, which has the following advantages: only one drying drum is used to realize the separate heating of waste and old asphalt coarse material and fine material, reducing the equipment floor area; the coarse material is fed from one end of the drum, and the fine material is fed through the air-material mixing pipe and the spiral conveying pipe, the fine material is indirectly heated by the flame and hot air in the moving state in the spiral conveying pipe, the heating time of the fine material in the spiral conveying pipe and the heating temperature of the fine material can be controlled by controlling the feeding amount of the impeller feeder and the size of the fan; the fine material is directly fed into the discharge ring through the spiral conveying pipe, most of the dust generated in the conveying of the fine material is retained in the drying drum and the discharge ring, reducing the working load of the dust removal device, and improving the utilization rate of the fine powder in the fine material. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure shows a layout structure diagram of the regenerated material drying and heating equipment.

[0019] The corresponding identification in the figure is as follows: 1-drying drum, 11-coarse material inlet, 12-discharge ring, 2-furnace, 21-thermal insulation cotton layer, 3-burner, 4-coarse material conveying device, 5-fine material conveying device, 51-fine material bin, 52-impeller feeder, 53-air-material mixing pipe, 531-air inlet, 532-air-material outlet, 533-fine material inlet, 54-fan, 55-spiral conveying pipe, 6-dust removal device, 61-negative pressure cover, 62-first induced draft fan, 63-second induced draft fan. DETAILED DESCRIPTION

[0020] The present application will be further described through specific embodiments.

[0021] Referring to Figure 1 The figure shows a layout structure diagram of the regenerated material drying and heating equipment.

[0022] The drying drum 1 has a coarse material inlet 11 at one end and a discharge ring 12 at the other end. The furnace 2 is connected to the discharge ring 12 at one end and a burner 3 at the other end. The coarse material conveying device 4 is connected to the coarse material inlet 11 of the drying drum 1. The fine material conveying device 5 includes a fine material bin 51, an impeller feeder 52, an air-material mixing pipe 53, a blower 54, and a spiral conveying pipe 55. The air-material mixing pipe 53 is a Venturi tube, which is horizontally arranged with an air inlet 531 at one end and an air-material outlet 532 at the other end. An upward-opening fine material inlet 533 is provided on the outer wall between the air inlet 531 and the gas-material outlet 532. The blower 54 is connected to the air inlet 531. The lower end of the fine material bin 51 is connected to the fine material inlet 533 via an impeller feeder 52. The spiral conveying pipe 55 is arranged around the inner wall of the furnace 2. The inlet end of the spiral conveying pipe 55 is connected to the gas-material outlet 532 of the gas-material mixing pipe 53, and the outlet end extends into the discharge ring 12. The outlet end of the spiral conveying pipe 55 is bent so that the outlet faces downward, and the horizontal position of the outlet end is higher than the flame outlet position of the burner 3. The spiral conveying pipe 55 is a seamless spiral steel pipe. The inner wall of the spiral conveying pipe 55 is coated with an anti-stick coating. The inner wall of the furnace 2 is provided with a heat insulation cotton layer 21, and the spiral conveying pipe 55 passes through the heat insulation cotton layer 21.

[0023] The dust removal device 6 includes a negative pressure hood 61, which is located at the coarse material inlet 11 of the drying drum 1. The dust removal device 6 includes a first induced draft fan 62 and a second induced draft fan 63. The suction ends of the first induced draft fan 62 and the second induced draft fan 63 are connected to the inside of the negative pressure hood 61. The exhaust end of the first induced draft fan 62 is connected to the dust collector. The exhaust end of the second induced draft fan 63 is connected to the end of the furnace 2 where the burner 3 is located and enters the furnace 2.

[0024] A method for drying and heating recycled materials, comprising the following steps:

[0025] Step 1: Waste asphalt is screened into coarse and fine materials. The coarse material is conveyed by coarse material conveying device 4, and the fine material is conveyed by fine material conveying device 5.

[0026] Step 2: The coarse material is fed into the drying drum 1 through the coarse material inlet 11, passes through the drying drum 1 and reaches the discharge ring 12 at the other end. The coarse material is heated by the hot air generated by the burner 3 during the process of passing through the drying drum 1.

[0027] The fine material is stored in the fine material bin 51, and the fine material is sent into the gas-material mixing pipe 53 by the impeller feeder 52 at a set feeding speed through the fine material inlet 533. The impeller feeder 52 continuously feeds a small amount of the fine material into the gas-material mixing pipe 53. The gas inlet 531 at one end of the gas-material mixing pipe 53 is connected to the fan 54, and high-pressure gas is sent into the gas-material mixing pipe 53 by the fan 54. The high-pressure gas wraps the fine material and sends the fine material out of the gas-material outlet 532 to the spiral conveying pipe 55. The spiral conveying pipe 55 spirally surrounds the inner wall of the hearth 2. The flame and hot gas of the burner 3 heat the spiral conveying pipe 55. The spiral conveying pipe 55 is located in the heat insulation cotton layer 21. The heat insulation cotton layer 21 blocks the flame from directly heating the spiral conveying pipe 55, and uniformly heats the spiral conveying pipe 55 as a whole, avoiding local overheating of the spiral conveying pipe 55. The fine material is heated in the process of passing through the spiral conveying pipe 55. The fine material is kept in a moving state during the heating process to reduce the sticking of the fine material. By controlling the feeding speed of the impeller feeder 52 and the size of the fan, the heating time of the fine material in the spiral conveying pipe 55 can be controlled, so that the fine material is heated to 60-70°C when it is sent out, avoiding overheating. The fine material is sent out of the outlet end of the spiral conveying pipe 55. Since the outlet end is bent downward and the horizontal position of the outlet end is higher than the flame outlet position of the burner 3, the fine material is sent downward and falls a certain distance. The water vapor generated during the heating of the fine material is brought into the drying drum 1 by the hot gas of the burner 3. The fine material falls into the discharge ring 12.

[0028] Step three, the fine material is mixed with the coarse material in the discharge ring 12 and then sent out.

[0029] During the process of step two, the dust generated by the coarse material conveying device 4 when sending the coarse material into the drying drum 1 through the coarse material inlet 11 is absorbed by the negative pressure cover 61. The dust generated when the fine aggregate is sent out of the outlet end of the spiral conveying pipe 55 is brought into the drying drum 1 by the hot gas. Most of these dusts cannot pass through the entire drying drum 1 and will be mixed with the coarse material in the drying drum 1 and sent back to the discharge ring 12 with the coarse material. Only a small amount of dust generated by the fine material conveying is absorbed by the negative pressure cover 61, reducing the load on the dust removal device 6 and ensuring the utilization rate of fine powder in the fine material.

[0030] Part of the exhaust gas absorbed by the negative pressure cover is sent to the dust collector by the first induced draft fan, and part of the exhaust gas is sent to one end of the hearth 2 provided with the burner 3 and into the hearth 2 by the second induced draft fan. The burner 3 burns harmful substances such as smoke in the exhaust gas.

[0031] The above is only one specific embodiment of the present application, but the design concept of the present application is not limited to this. Any non-essential modification of the present application using this concept shall be deemed to infringe the protection scope of the present application.

Claims

1. A regenerative drying heating device, comprising a drying drum, a furnace, a burner, a coarse material conveying device, one end of the drying drum is provided with a coarse material inlet, the other end is provided with a discharge ring, one end of the furnace is connected to the discharge ring, the other end is provided with the burner, and the coarse material conveying device is connected to the coarse material inlet of the drying drum, characterized in that: The fine material conveying device comprises a fine material bin, an impeller feeder, a gas-material mixing pipe, a fan and a screw conveying pipe. The gas-material mixing pipe is horizontally arranged and has an air inlet at one end and a gas-material outlet at the other end. An upwardly-opening fine material inlet is formed in the outer wall of the gas-material mixing pipe between the air inlet and the gas-material outlet. The fan is connected to the air inlet. The lower end of the fine material bin is connected to the fine material inlet through the impeller feeder. The screw conveying pipe is arranged in the furnace along the inner wall of the furnace. The inlet end of the screw conveying pipe is connected to the gas-material outlet of the gas-material mixing pipe, and the outlet end extends into the discharge ring. ​ Based on the above device, a method for drying and heating reclaimed materials comprises the following steps: Step one: waste asphalt is screened into coarse materials and fine materials; Step two: the coarse materials are fed into the coarse material inlet of the drying drum and then reach the discharge ring at the other end of the drying drum through the drying drum. The coarse materials are heated by the hot gas generated by the burner during the process of passing through the drying drum. The fine materials are fed into the gas-material mixing pipe through the fine material inlet by the impeller feeder at a set feeding speed. The high-pressure gas is fed into the air inlet at one end of the gas-material mixing pipe. The high-pressure gas wraps the fine materials and feeds the fine materials out of the gas-material outlet to the screw conveying pipe. The screw conveying pipe spirally surrounds the inner wall of the furnace. The flame and hot gas of the burner heat the screw conveying pipe. The fine materials are heated during the process of passing through the screw conveying pipe. After the fine materials are fed out of the screw conveying pipe, they reach the discharge ring. Step three: the fine materials and the coarse materials are mixed in the discharge ring and then fed out. The inner wall of the furnace is provided with a heat preservation cotton layer, and the screw conveying pipe is wrapped in the heat preservation cotton layer.

2. The recycled material drying and heating apparatus according to claim 1, wherein: The outlet end of the screw conveying pipe is bent to the outlet downward, and the horizontal position of the outlet end is higher than the outlet position of the flame of the burner.

3. The recycled material drying and heating apparatus according to claim 1, wherein: The screw conveying pipe is a seamless spiral steel pipe.

4. The recycled material drying and heating apparatus according to claim 1, wherein: The inner wall of the screw conveying pipe is coated with an anti-sticking coating.

5. The recycled material drying and heating apparatus as claimed in claim 1, wherein: The gas-material mixing pipe is a Venturi tube.

6. The recycled material drying and heating apparatus as claimed in claim 1, wherein: The dust removal device comprises a negative pressure cover arranged at the coarse material inlet of the drying drum.

7. The reclaimed material drying and heating apparatus according to claim 6, wherein: The dust removal device comprises a first induced draft fan and a second induced draft fan. The suction ends of the first induced draft fan and the second induced draft fan are connected to the negative pressure cover. The air outlet end of the first induced draft fan is connected to a dust collector, and the air outlet end of the second induced draft fan is connected to one end of the furnace provided with the burner and extends into the furnace.

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