Precision heating thermal desorption rotary kiln to prevent wall sticking

Abstract

The present invention provides a precision heating thermal desorption rotary kiln that prevents soil from sticking to the wall, which relates to the technical field of contaminated soil treatment and solves the technical problems in the prior art that the thermal desorption rotary kiln is prone to soil sticking to the wall and the heat distribution is uneven. The precision heating thermal desorption rotary kiln device that prevents soil from sticking to the wall comprises a rotary kiln body, a clay removal device and a heating device; wherein the rotary kiln body comprises a kiln head, a kiln body and a kiln tail, the two ends of the kiln body are rotatably connected to the kiln head and the kiln tail respectively, the clay removal device is arranged in the upper area of ​​the kiln head and can peel off the soil adhered to the inner wall during the rotation of the kiln body; the heating device comprises at least two flue gas nozzles evenly distributed along the axis of the kiln body, and each of the flue gas nozzles can spray high-temperature flue gas into the kiln body. The present invention is used to provide a precision heating thermal desorption rotary kiln that can peel off the soil adhered to the wall of the kiln body and heat it evenly to prevent soil from sticking to the wall.

Description

Technical Field

[0001] The present invention relates to the technical field of contaminated soil treatment, and in particular to a precise heating thermal desorption rotary kiln capable of preventing wall sticking. Background Art

[0002] Ex situ thermal desorption technology heats the target pollutants in the contaminated soil to above their boiling point by direct or indirect heating, and selectively promotes the gasification and volatilization of pollutants by controlling the system temperature and material residence time, so that the target pollutants are separated and removed from the soil particles. Ex situ thermal desorption technology is mainly aimed at the removal of volatile and semi-volatile organic pollutants in the soil, such as (petroleum hydrocarbons, pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls) and mercury compounds.

[0003] Among them, the thermal desorption rotary kiln is the main device for separating pollutants from soil in ex situ thermal desorption. At present, the thermal desorption rotary kiln is divided into indirect thermal desorption rotary kiln and direct thermal desorption rotary kiln. Among them, the indirect thermal desorption rotary kiln is usually composed of an inner cylinder and an outer cylinder. The polluted soil moves from the feed port to the discharge port in the inner cylinder under the push of the spiral rod. High-temperature flue gas is passed between the inner and outer cylinders. The high-temperature flue gas and the soil are indirectly heated through the wall of the inner cylinder. The heat exchange efficiency is low. At the same time, high-humidity soil particles are prone to sticking to the wall when encountering the high-temperature cylinder wall, which needs to be treated regularly.

[0004] A direct thermal desorption rotary kiln usually has a combustion flame introduced into one end and soil fed into the other end. Under the action of gravity and a lifting plate, the soil directly exchanges heat with the high-temperature flue gas in reverse contact. The direct thermal desorption rotary kiln is usually divided into a feeding section, a desorption section, and a discharging section. The feeding section is the soil preheating stage, and the desorption section is the main location for soil thermal desorption. The feeding section and the desorption section require a large amount of heat, and the main function of the discharging section is to prevent the discharging soil from blocking the flame. Since the thermal desorption rotary kiln body is relatively long (10-20m) and the flame spray distance is 1-2m, the temperature of the discharging section that absorbs less heat is high, while the temperature of the feeding section and the desorption section that absorb more heat is low. The heat distribution inside the kiln body is unreasonable, and the soil inevitably contacts with the high-temperature flame, resulting in the burning of soil organic matter, and the reuse range of the treated soil is narrow. Summary of the invention

[0005] The purpose of the present invention is to provide a precise heating thermal desorption rotary kiln device that prevents soil from sticking to the wall, so as to solve the technical problems in the prior art that the thermal desorption rotary kiln is prone to soil sticking to the wall and the heat distribution is uneven. The preferred technical solutions among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The invention provides a precise heating thermal desorption rotary kiln device for preventing wall sticking, comprising a rotary kiln body, a clay removal device and a heating device; wherein:

[0008] The rotary kiln body comprises a kiln head, a kiln body and a kiln tail. The kiln body is a cylindrical structure. The two ends of the kiln body are rotatably connected to the kiln head and the kiln tail respectively so that the kiln body can rotate around its own axis. The clay removal device is arranged in the upper area of ​​the kiln head and can remove the soil adhered to the inner wall of the kiln body during the rotation of the kiln body. The heating device comprises at least two smoke nozzles evenly distributed along the axis of the kiln body, and each of the smoke nozzles can spray high-temperature smoke into the kiln body.

[0009] In a preferred or optional embodiment, the clay removal device includes a high-pressure nozzle, which is arranged in the upper area of ​​the kiln head, and the air outlet of the high-pressure nozzle is arranged parallel to the axis of the kiln body and is close to the inner wall surface of the kiln body in the radial direction.

[0010] In a preferred or optional embodiment, the clay removal device further comprises an air compressor, and an air outlet of the air compressor is connected to an air inlet of the high-pressure nozzle.

[0011] In a preferred or optional embodiment, it is characterized in that the heating device also includes a support tube and at least two smoke branch pipes, and the two ends of the support tube are respectively fixed to the kiln head and the kiln tail; each of the smoke branch pipes is connected to a smoke nozzle, each of the smoke branch pipes is fixed inside the support tube, and each of the smoke nozzles is fixed on the wall of the support tube so that its outlet is located inside the kiln body.

[0012] In a preferred or optional embodiment, the heating device further comprises a burner and an induced draft fan, the induced draft fan is connected to the burner, and each of the flue gas branch pipes is connected to an airflow outlet of the induced draft fan.

[0013] In a preferred or optional embodiment, a regulating valve is respectively provided at the connection point between each of the smoke branch pipes and the induced draft fan.

[0014] In a preferred or optional embodiment, the regulating valve is a flow valve.

[0015] In a preferred or optional embodiment, the distance between two adjacent smoke nozzles is 0.5 m to 1.5 m.

[0016] In a preferred or optional embodiment, the gas outlet of each of the smoke nozzles is arranged downward.

[0017] In a preferred or optional embodiment, the top of the support tube is set at a sharp angle, and at the sharp angle, the angle between the tube wall of the support tube and the vertical direction is smaller than the accumulation angle of the soil.

[0018] The invention provides a rotary kiln device for preventing wall adhesion by precise heating and thermal desorption, comprising a rotary kiln body, a clay removal device and a heating device. The rotary kiln body comprises a kiln head, a kiln tail and a rotatable kiln body. When the soil is subjected to thermal desorption treatment, the contaminated soil is located in the kiln body. Since the clay removal device is arranged on the kiln head, the adhered soil can be peeled off during the rotation of the kiln body, and regular treatment is not required, thereby improving the working efficiency of the equipment. At least two flue gas nozzles are evenly distributed on the axis of the kiln body, and high-temperature flue gas can be sprayed on the soil in the kiln body. Since the nozzles are evenly distributed, the soil in the kiln body can be evenly heated. Since the nozzles spray high-temperature flue gas, direct contact between the flame and the soil is avoided, and organic matter in the soil is prevented from being burned. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a precise heating and thermal desorption rotary kiln device for preventing wall sticking provided by the present invention;

[0021] Figure 2 for Figure 1 The schematic diagram of the structure of some sections of the heating device shown;

[0022] Figure 3 for Figure 1 The side view structural schematic diagram of the precision heating thermal desorption rotary kiln device for preventing wall sticking is shown.

[0023] In the figure, 1. rotary kiln body; 11. kiln head; 111. screw feeder; 12. kiln body; 121. feed end; 122. desorption section; 123. discharge section; 13. kiln tail; 131. smoke exhaust port; 132. discharge port; 2. clay removal device; 21. high-pressure nozzle; 3. heating device; 31. flue gas nozzle; 32. support pipe; 33. flue gas branch pipe; 34. burner; 35. induced draft fan; 36. regulating valve. DETAILED DESCRIPTION

[0024] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0025] The invention provides a precise heating thermal desorption rotary kiln which can peel off soil adhering to the wall surface of a kiln body and heat evenly to prevent soil from adhering to the wall.

[0026] Combine the following Figure 1 to Figure 3 The technical solution provided by the present invention is described in more detail.

[0027] like Figure 1 to Figure 3 As shown, the precise heating thermal desorption rotary kiln device for preventing wall sticking provided by the present invention comprises a rotary kiln body 1, a clay removal device 2 and a heating device 3; wherein,

[0028] The rotary kiln body 1 includes a kiln head 11, a kiln body 12 and a kiln tail 13. The kiln body 12 is a cylindrical structure. The two ends of the kiln body 12 are rotatably connected to the kiln head 11 and the kiln tail 13 respectively so that the kiln body 12 can rotate around its own axis. The clay removal device 2 is arranged in the upper area of ​​the kiln head 11 and can remove the soil adhered to the inner wall of the kiln body 12 during its rotation; the heating device 3 includes at least two smoke nozzles 31 evenly distributed along the axis of the kiln body 12, and each smoke nozzle 31 can spray high-temperature smoke into the kiln body 12.

[0029] Specifically, a screw feeder 111 is provided on the kiln head 11, and a smoke exhaust port 131 and a discharge port 132 are provided on the kiln tail 13. When thermal desorption is performed, the contaminated soil enters the kiln body 12 under the push of the screw feeder 111. The kiln body 12 includes a feed end 121, a desorption section 122 and a discharge section 123. The contaminated soil is evenly spread through the feed end 121, the desorption section 122 and the discharge section 123 under the action of the lifting plates, and gradually moves toward the discharge port 132. At the same time, under the action of the high-temperature flue gas of the heating device 3, the pollutants are desorbed from the soil and discharged through the smoke exhaust port 131 for centralized treatment and emission. The treated soil is discharged through the discharge port 132 for centralized collection. During this period, the clay removal device 2 can peel off the soil adhering to the wall of the kiln body 12.

[0030] The invention provides a rotary kiln device for preventing wall adhesion by precise heating and thermal desorption, comprising a rotary kiln body 1, a clay removal device 2 and a heating device 3. The rotary kiln body 1 comprises a kiln head 11, a kiln tail 13 and a rotatable kiln body 12. When the soil is subjected to thermal desorption treatment, the contaminated soil is located in the kiln body 12. Since the clay removal device 2 is arranged on the kiln head 11, the soil adhering to the kiln body 12 can be peeled off without regular treatment during the rotation of the kiln body 12, thereby improving the working efficiency of the equipment. At least two flue gas nozzles 31 are evenly distributed on the axis of the kiln body 12, and high-temperature flue gas can be sprayed on the soil in the kiln body 12. Since the flue gas nozzles 31 are evenly distributed, the soil in the kiln body 12 can be evenly heated. Since the high-temperature flue gas is sprayed, direct contact between the flame and the soil is avoided, and organic matter in the soil is prevented from being burned.

[0031] As a preferred or optional embodiment, the clay removal device 2 includes a high-pressure nozzle 21, which is arranged in the upper area of ​​the kiln head 11, and the air outlet of the high-pressure nozzle 21 is arranged parallel to the axis of the kiln body 12 and is close to the inner wall surface of the kiln body 12 in the radial direction.

[0032] Specifically, if it is assumed that the kiln body 12 rotates counterclockwise, the cylindrical kiln body 12 is divided into four quadrants, the high-pressure nozzle 21 is set in the second quadrant, and the high-pressure nozzle 21 is fixed on the kiln head 11 so that it does not rotate with the kiln body 12 and is close to the inner wall of the kiln body 12 in the radial direction. The soil is concentrated in the first, third and fourth quadrants as the kiln body 12 rotates, and only the soil adhered to the inner wall of the kiln body 12 can reach the second quadrant; when the soil adheres to the wall, the high-pressure nozzle 21 intermittently sprays high-pressure airflow, and the adhered soil falls off from the inner wall of the kiln body 12 under the impact of the high-pressure airflow and the action of gravity, thereby effectively solving the wall adhesion problem.

[0033] As a preferred or optional embodiment, the clay removal device 2 further includes an air compressor, and an air outlet of the air compressor is connected to an air inlet of the high-pressure nozzle 21 .

[0034] As a preferred or optional embodiment, the heating device 3 also includes a support tube 32 and at least two flue gas branches 33, the two ends of the support tube 32 are respectively fixedly connected to the kiln head 11 and the kiln tail 13; each flue gas branch 33 is connected to a flue gas nozzle 31, each flue gas branch 33 is fixed inside the support tube 32, and each flue gas nozzle 31 is fixed on the wall of the support tube 32 so that its outlet is located inside the kiln body.

[0035] As a preferred or optional embodiment, the heating device 3 further includes a burner 34 and an induced draft fan 35 . The induced draft fan 35 is connected to the burner 34 , and each flue gas branch pipe 33 is connected to the airflow outlet of the induced draft fan 35 .

[0036] Specifically, the high-temperature flue gas generated by the flame of the burner 34 is injected into the flue gas branch pipe 33 through the high-temperature resistant induced draft fan 35, and then sprayed out from each flue gas nozzle 31 to act on the soil.

[0037] As a preferred or optional implementation, a regulating valve 36 is provided at the connection point between each smoke branch pipe 33 and the induced draft fan 35 .

[0038] As a preferred or optional embodiment, the regulating valve 36 is a flow valve. The flow rate of high-temperature flue gas ejected from each flue gas nozzle 31 can be accurately controlled by adjusting the flow valve, thereby achieving accurate heating of the contaminated soil inside the kiln body 12 and improving the utilization rate of thermal energy.

[0039] As a preferred or optional embodiment, the distance between two adjacent smoke nozzles 31 is 0.5 m to 1.5 m.

[0040] As a preferred or optional embodiment, the gas outlet of each smoke nozzle 31 is arranged downward, so as to directly act on the soil and improve the utilization rate of heat energy.

[0041] As a preferred or optional embodiment, the top of the support tube 32 is set as a sharp angle, and the angle between the tube wall of the support tube 32 and the vertical direction at the sharp angle is smaller than the accumulation angle of the soil.

[0042] Specifically, since the support tube 32 does not rotate with the kiln body 12, the stripped soil easily falls on the top of the support tube 32. Setting the top of the support tube 32 as a sharp angle can prevent soil from piling up on the support tube 32, avoid excessive load on the support tube 32, and increase its service life.

[0043] In addition, the present invention reduces the length of the discharging section 123 and the overall length of the rotary kiln body 1, making it easier to install and transport the equipment, and making more reasonable use of the internal space of the kiln body 12.

[0044] Unless otherwise stated, any technical solution disclosed in the present invention disclosed above, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range, and any technician in the field should understand that the preferred numerical range is only a numerical value with a more obvious technical effect or representative value among many implementable numerical values. Since there are too many numerical values ​​to be exhaustive, the present invention discloses some numerical values ​​to illustrate the technical solution of the present invention, and the numerical values ​​listed above should not constitute a limitation on the scope of protection of the present invention.

[0045] If the words "first", "second" and so on are used in this article to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of description to distinguish the components. Unless otherwise stated, the above words have no special meaning.

[0046] Meanwhile, if the above invention discloses or involves mutually fixedly connected parts or structural parts, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), or as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutually fixed connection can also be an integrated structure (for example, one-piece manufacturing using a casting process) (except where it is obviously impossible to use an integrated molding process).

[0047] In addition, the terms used in any technical solution disclosed in the present invention to indicate positional relationships or shapes include states or shapes that are similar, similar or close to them unless otherwise stated. Any component provided by the present invention may be assembled from multiple separate components or may be a separate component manufactured by an integrated molding process.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A precision heating thermal desorption rotary kiln device to prevent wall sticking, characterized in that: It includes a rotary kiln body, a clay removal device and a heating device; wherein, The rotary kiln body comprises a kiln head, a kiln body and a kiln tail, the kiln body is a cylindrical structure, the two ends of the kiln body are respectively connected to the kiln head and the kiln tail so that the kiln body can rotate around its own axis, the clay removal device is arranged in the upper area of ​​the kiln head and can remove the soil adhering to the inner wall of the kiln body during the rotation of the kiln body; the heating device comprises at least two smoke nozzles evenly distributed along the axis of the kiln body, each of which can spray high-temperature smoke into the kiln body; The clay removal device comprises a high-pressure nozzle, which is arranged in the upper area of ​​the kiln head, and the air outlet of the high-pressure nozzle is arranged parallel to the axis of the kiln body and is close to the inner wall surface of the kiln body in the radial direction; The clay removal device further comprises an air compressor, wherein an air outlet of the air compressor is connected to an air inlet of the high-pressure nozzle; The heating device further comprises a support pipe and at least two smoke branch pipes, the two ends of the support pipe are respectively fixedly connected to the kiln head and the kiln tail; each of the smoke branch pipes is connected to a smoke nozzle, each of the smoke branch pipes is fixed inside the support pipe, and each of the smoke nozzles is fixed on the wall surface of the support pipe so that its gas outlet is located inside the kiln body; The heating device further comprises a burner and an induced draft fan, the induced draft fan is connected to the burner, and each of the smoke branch pipes is connected to an airflow outlet of the induced draft fan; A regulating valve is provided at the connection point between each of the smoke branch pipes and the induced draft fan; The regulating valve is a flow valve; The distance between two adjacent smoke nozzles is 0.5m to 1.5m.

2. The precise heating and thermal desorption rotary kiln device for preventing wall sticking according to claim 1 is characterized in that: The gas outlet of each of the smoke nozzles is arranged downward.

3. The precise heating and thermal desorption rotary kiln device for preventing wall sticking according to claim 1 is characterized in that: The top of the support pipe is set at a sharp angle, and at the sharp angle, the angle between the pipe wall of the support pipe and the vertical direction is smaller than the accumulation angle of the soil.

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