A rotary kiln head sealing structure

Abstract

This invention provides a rotary kiln head sealing structure, including a kiln head hood, a rotary kiln body, a cooling air jacket, and a sealing outer sleeve. The front end of the rotary kiln body passes through the kiln head hood. The cooling air jacket includes an inner sleeve and an outer sleeve, with an annular air inlet channel formed between the inner sleeve and the rotary kiln body, and an annular return air channel connected to the annular air inlet channel at its front end between the outer sleeve and the inner sleeve. The sealing outer sleeve is fitted over the cooling air jacket, with its front end connected to the kiln head hood. A first annular cooling air box is provided at the rear end of the sealing outer sleeve, and a cooling air nozzle aligned with the rear end of the cooling air jacket is provided on the first annular cooling air box. A first air source interface is provided outside the first annular cooling air box. A front annular cavity and a rear annular cavity are sequentially provided between the sealing outer sleeve and the cooling air jacket, with a discharge port connected to the bottom of the front annular cavity. A first nozzle connecting the annular return air channel and the rear annular cavity is provided on the outer sleeve. This invention not only prevents the cooling air jacket from clogging but also ensures the cooling effect of the kiln head body.

Description

Technical Field

[0001] This invention relates to the field of rotary kiln technology, and more specifically to a rotary kiln head sealing structure. Background Technology

[0002] A rotary kiln is a common material calcination equipment. During the calcination process, the rotary kiln cylinder rotates, and there will be a certain gap at the connection between the rotary kiln cylinder and the kiln head hood. It is necessary to install a rotary kiln head sealing structure to seal it.

[0003] During production, abnormalities in the rotary kiln or preheater system can cause short-term positive pressure at the kiln head. This is especially frequent and severe during the heating and feeding phase after the kiln system has been shut down for maintenance and is resuming production. If there is air leakage at the kiln head, it will lower the secondary air temperature of the rotary kiln, causing heat loss. When the above situation occurs, a large amount of high-temperature, dust-laden gas will be ejected from the air leakage point at the kiln head, polluting the on-site environment and posing a safety hazard.

[0004] Chinese patent CN204313638U discloses a novel kiln head sealing device, including an outer sealing jacket (sealing cover) and an inner cold air jacket. Two labyrinth sealing plates are provided between the sealing jacket and the cold air jacket. Cold air is introduced into the cold air jacket to cool the kiln head cylinder. When flying sand is sprayed out from the gap between the rotary kiln cylinder and the kiln head cover, it will be blocked by the two labyrinth sealing plates. However, a small amount of flying sand will pass through the labyrinth and be blown into the cold air jacket along with the cold air, which can easily cause blockage inside the cold air jacket.

[0005] Chinese patent CN204421589U discloses a rotary kiln labyrinth-type kiln head sealing device, including an outer sealing jacket (outer air duct) and an inner cold air jacket. Two labyrinth sealing plates (a first sector-shaped sealing plate and a second sector-shaped sealing plate) are provided between the sealing jacket and the cold air jacket. When flying sand is sprayed out from the gap between the rotary kiln cylinder and the kiln head cover, it will be blocked by the two labyrinth sealing plates. At the same time, when the cold air is blown out from the blower nozzle, part of it is blown into the cold air jacket to cool the kiln head cylinder, and part of it is blown into the space between the sealing jacket and the cold air jacket. After merging, they are discharged together to the grate cooler. It can not only cool the kiln head cylinder, but also prevent flying sand from passing through the labyrinth and prevent flying sand from being blown into the cold air jacket and causing blockage of the cold air jacket. However, the ratio of the amount of cold air blown out from the blower nozzle into the cold air jacket and between the cold air jacket and the sealing jacket is difficult to control. It is easy for the amount of air blown into the cold air jacket to be too small, which will affect the cooling effect of the kiln head cylinder. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a rotary kiln head sealing structure that can not only prevent the cold air jacket from being blocked, but also ensure the cooling effect of the kiln head cylinder.

[0007] This invention provides a rotary kiln head sealing structure, comprising:

[0008] Kiln head cover;

[0009] A rotary kiln shell, with a kiln inlet guard iron installed at the front end of the rotary kiln shell and inserted into the kiln head cover, and an annular gap between the rotary kiln shell and the kiln head cover;

[0010] The cold air jacket includes an inner sleeve fitted outside the rotary kiln shell and an outer sleeve fitted outside the inner sleeve. An annular air inlet channel is formed between the inner sleeve and the rotary kiln shell. The front end of the outer sleeve is connected to the kiln inlet guard. An annular air return channel is formed between the outer sleeve and the inner sleeve. The annular air inlet channel and the annular air return channel are connected at the kiln inlet guard.

[0011] A sealing jacket is fitted over the cold air jacket. The front end of the sealing jacket is connected to the kiln head hood, and the rear end of the sealing jacket is provided with a first annular cold air box. The first annular cold air box is provided with cold air nozzles aligned with the rear end of the cold air jacket along its circumference. A first air source interface is provided outside the first annular cold air box. A front annular cavity and a rear annular cavity are provided between the sealing jacket and the cold air jacket. The front and rear ends of the front annular cavity are respectively connected to the annular gap and the rear annular cavity. A discharge port is connected to the bottom of the front annular cavity. The outer jacket is provided with a first nozzle along its circumference, with both ends connected to the annular return air duct and the rear annular cavity respectively and facing obliquely forward.

[0012] Furthermore, the rear end of the cooling sleeve is provided with a flared opening.

[0013] Furthermore, the inner circumferential surface of the inner sleeve is provided with multiple longitudinally extending support bars that support the outside of the rotary kiln cylinder.

[0014] Furthermore, the kiln inlet guard has a first connecting part, a second connecting part, and a third connecting part connected between the first connecting part and the second connecting part. The first connecting part is fixed to the rotary kiln cylinder by bolts, and the rear side of the second connecting part is provided with a groove that engages with the front end of the outer sleeve.

[0015] Furthermore, a second annular cold air box is provided outside the rear annular cavity, a second air source interface is provided outside the second annular cold air box, and a second nozzle is provided on the inner wall of the second annular cold air box, with both ends communicating with the second annular cold air box and the rear annular cavity respectively and facing obliquely forward.

[0016] Furthermore, the rear annular cavity is formed into an annular conical cavity with a narrow rear end and a wide front end.

[0017] Furthermore, heat-resistant steel fish scales are fixed to the inner ring of the rear end of the first annular cold air box and pressed against the outer surface of the rotary kiln cylinder.

[0018] Furthermore, a conical ring is provided at the rear end of the first annular cold air box near the inner ring, and one end of the heat-resistant steel fish scale is fixed outside the conical ring.

[0019] The beneficial effects of this invention are reflected in:

[0020] During operation, an external fan is connected to the first air source interface. The fan introduces cold air into the first annular cold air box. The cold air entering the first annular cold air box is sprayed into the annular air inlet through the cold air nozzle and flows forward along the annular air inlet. After flowing to the kiln inlet guard, it enters the annular return air duct and flows backward. Then, it is sprayed diagonally forward into the rear annular cavity through the first nozzle on the outer casing. Finally, it enters the front annular cavity and is discharged from the discharge port together with the flying sand material sprayed from the annular gap between the rotary kiln cylinder and the kiln head hood.

[0021] As the airflow passes through the annular inlet and return air channels within the cold air jacket, it carries away heat, cooling the rotary kiln head cylinder and kiln inlet guard. The airflow from the cold air nozzles is directed towards the cold air jacket to ensure sufficient airflow to meet the cooling requirements of the kiln head cylinder, thus guaranteeing the cooling effect. The cooled airflow is then injected diagonally forward into the rear annular cavity, preventing flying sand from passing through and thus avoiding blockage caused by flying sand being blown into the cold air jacket. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0023] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0024] Figure 2 for Figure 1 AA section view;

[0025] Figure 3 for Figure 1 BB cross-sectional view;

[0026] Figure 4 for Figure 1 CC section view.

[0027] In the attached diagram, 100-kiln head hood; 200-rotary kiln cylinder; 210-kiln inlet guard; 211-first connecting part; 212-second connecting part; 2121-slot; 213-third connecting part; 214-bolt; 220-annular gap; 300-cold air jacket; 310-inner sleeve; 311-flare mouth; 312-support bar; 320-outer sleeve; 321-first nozzle; 330-annular air inlet duct; 340-annular air return duct; 400-sealing outer sleeve; 410-first annular cold air box; 411-cold air nozzle; 412-first air source interface; 413-conical ring; 420-front annular cavity; 421-discharge port; 430-rear annular cavity; 440-second annular cold air box; 441-second air source interface; 442-second nozzle; 500-heat resistant steel fish scales. Detailed Implementation

[0028] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0029] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by those skilled in the art to which this invention pertains.

[0030] Example 1

[0031] like Figures 1-4 As shown, an embodiment of the present invention provides a rotary kiln head sealing structure, including a kiln head cover 100, a rotary kiln body 200, a cold air jacket 300, and a sealing jacket 400.

[0032] A kiln inlet guard 210 is installed at the front end of the rotary kiln cylinder 200 and passes through the kiln head cover 100. There is an annular gap 220 between the rotary kiln cylinder 200 and the kiln head cover 100.

[0033] The cold air jacket 300 includes an inner sleeve 310 fitted outside the rotary kiln cylinder 200 and an outer sleeve 320 fitted outside the inner sleeve 310. An annular air inlet channel 330 is formed between the inner sleeve 310 and the rotary kiln cylinder 200. The front end of the outer sleeve 320 is connected to the kiln inlet guard 210. An annular air return channel 340 is formed between the outer sleeve 320 and the inner sleeve 310. The annular air inlet channel 330 and the annular air return channel 340 are connected at the kiln inlet guard 210.

[0034] A sealing jacket 400 is fitted over a cold air jacket 300. The front end of the sealing jacket 400 is connected to a kiln head hood 100. A first annular cold air box 410 is provided at the rear end of the sealing jacket 400. The first annular cold air box 410 is provided with cold air nozzles 411 aligned with the rear end of the cold air jacket 300 along its circumference. A first air source interface 412 is provided outside the first annular cold air box 410. A front annular cavity 420 and a rear annular cavity 430 are provided between the sealing jacket 400 and the cold air jacket 300. The front and rear ends of the front annular cavity 420 are respectively connected to the annular gap 220 and the rear annular cavity 430. A discharge port 421 is connected to the bottom of the front annular cavity 420. The jacket 320 is provided with a first nozzle 321 along its circumference, which is connected to the annular return air duct 340 and the rear annular cavity 430 respectively and faces obliquely forward.

[0035] Generally, the width of the annular air inlet 330 is relatively narrow. In order to ensure that the airflow ejected from the cold air nozzle 411 can be smoothly injected into the annular air inlet 330, the rear end of the cold air jacket 300 is provided with a flared mouth 311.

[0036] Furthermore, the inner circumferential surface of the inner sleeve 310 is provided with multiple longitudinally extending support bars 312 that support the rotary kiln cylinder 200. The support bars 312 not only support the cold air jacket 300 outside the rotary kiln cylinder 200, but also increase the heat exchange area and improve the cooling effect of the kiln head cylinder.

[0037] The specific connection method between the kiln inlet guard 210, the rotary kiln body 200, and the cooling air jacket 300 is as follows: Figure 1 As shown, the kiln inlet guard 210 has a first connecting part 211, a second connecting part 212, and a third connecting part 213 connected between the first connecting part 211 and the second connecting part 212. The first connecting part 211 is fixed inside the rotary kiln cylinder 200 by bolts 214. The rear side of the second connecting part 212 is provided with a slot 2121 that engages with the front end of the outer sleeve 320. During assembly, the first connecting part 211 of the kiln inlet guard 210 is first fixed inside the rotary kiln body 200 with bolts 214. Then, the cold air sleeve 300 is put on the outside of the rotary kiln body 200 and the front end of the outer sleeve 320 of the cold air sleeve 300 is inserted into the slot 2121 of the second connecting part 212 of the kiln inlet guard 210. This not only facilitates assembly, but also improves the sealing between the cold air sleeve 300 and the kiln inlet guard 210 by inserting the outer sleeve 320 of the cold air sleeve 300 into the slot 2121 of the second connecting part 212 of the kiln inlet guard 210, ensuring that there is basically no air leakage between the cold air sleeve 300 and the kiln inlet guard 210.

[0038] In addition, a heat-resistant steel fish-scale sheet 500 is fixed to the inner ring of the rear end of the first annular cold air box 410, pressing against the outer surface of the rotary kiln cylinder 200. By setting the fish-scale seal, airflow loss can be reduced and slight dust can be prevented, so as to achieve the best sealing effect. In order to facilitate the installation of the heat-resistant steel fish-scale sheet 500, a conical ring 413 is provided at the inner ring of the rear end of the first annular cold air box 410, and one end of the heat-resistant steel fish-scale sheet 500 is fixed to the outside of the conical ring 413.

[0039] In this embodiment, when the first air source interface 412 is connected to an external fan, the fan introduces cold air into the first annular cold air box 410, the cold air into the first annular cold air box 410 is sprayed into the annular air inlet 330 through the cold air nozzle 411 and flows forward along the annular air inlet 330. After flowing to the kiln mouth guard 210, it enters the annular return air duct 340 and flows backward. Then it is sprayed diagonally forward into the rear annular cavity 430 through the first nozzle 321 on the outer casing 320, and finally enters the front annular cavity 420. Together with the flying sand material sprayed from the annular gap 220 between the rotary kiln cylinder 200 and the kiln head cover 100, it is discharged from the discharge port 421.

[0040] As the airflow passes through the annular air inlet duct 330 and annular air return duct 340 within the cold air jacket 300, it carries away heat, which can cool the cylinder of the rotary kiln head and the kiln mouth guard 210. The airflow ejected from the cold air nozzle 411 is all directed towards the cold air jacket 300 to ensure that the airflow entering the cold air jacket 300 is sufficient to meet the cooling requirements of the kiln head cylinder, thus ensuring the cooling effect of the kiln head cylinder. The airflow after cooling the kiln head is injected into the rear annular cavity 430 at an angle to the front, which can block the flying sand material from passing through the rear annular cavity 430, thereby preventing the flying sand material from being blown into the cold air jacket 300 and causing blockage.

[0041] Example 2

[0042] Example 2 is a further improvement on Example 1, referring to... Figure 1 and Figure 3 A second annular cold air box 440 is provided outside the rear annular cavity 430. A second air source interface 441 is provided outside the second annular cold air box 440. A second nozzle 442 is provided on the inner wall of the second annular cold air box 440, with both ends communicating with the second annular cold air box 440 and the rear annular cavity 430 respectively and facing obliquely forward.

[0043] During operation, a fan can be connected to the second air source interface 441. The fan introduces cold air into the second annular cold air box 440. The cold air is then injected into the rear annular cavity 430 through the second nozzle 442 and mixed with the hot air ejected from the first nozzle 321. Then, they enter the front annular cavity 420 together. This not only regulates the air volume injected into the front annular cavity 420 to ensure the airflow's suppressive effect on the flying sand, but also reduces the temperature of the airflow by mixing the cold air ejected from the second nozzle 442 with the hot air ejected from the first nozzle 321, thereby reducing the temperature outside the sealing jacket 400.

[0044] Preferably, the rear annular cavity 430 is an annular conical cavity with a narrow rear end and a wide front end. This can reduce the amount of airflow flowing out of the rear annular cavity 430 and improve the utilization rate of airflow.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A rotary kiln head sealing structure, characterized in that, include: Kiln head cover; A rotary kiln shell, with a kiln inlet guard iron installed at the front end of the rotary kiln shell and inserted into the kiln head cover, and an annular gap between the rotary kiln shell and the kiln head cover; The cold air jacket includes an inner sleeve fitted outside the rotary kiln shell and an outer sleeve fitted outside the inner sleeve. An annular air inlet channel is formed between the inner sleeve and the rotary kiln shell. The front end of the outer sleeve is connected to the kiln inlet guard. An annular air return channel is formed between the outer sleeve and the inner sleeve. The annular air inlet channel and the annular air return channel are connected at the kiln inlet guard. A sealing jacket is fitted over the cold air jacket. The front end of the sealing jacket is connected to the kiln head hood, and the rear end of the sealing jacket is provided with a first annular cold air box. The first annular cold air box is provided with cold air nozzles aligned with the rear end of the cold air jacket along its circumference. A first air source interface is provided outside the first annular cold air box. A front annular cavity and a rear annular cavity are provided between the sealing jacket and the cold air jacket. The front and rear ends of the front annular cavity are respectively connected to the annular gap and the rear annular cavity. A discharge port is connected to the bottom of the front annular cavity. The outer jacket is provided with a first nozzle along its circumference, with both ends connected to the annular return air duct and the rear annular cavity respectively, and facing obliquely forward. The cold air flow entering the first annular cold air box is sprayed into the annular air inlet duct through the cold air nozzles and flows forward along the annular air inlet duct. After flowing to the kiln mouth guard, it enters the annular return air duct and flows backward. Then, it is sprayed obliquely forward into the rear annular cavity through the first nozzle on the outer jacket and finally enters the front annular cavity.

2. The rotary kiln head sealing structure according to claim 1, characterized in that, The rear end of the cooling sleeve is equipped with a flared opening.

3. The rotary kiln head sealing structure according to claim 1, characterized in that, The inner circumferential surface of the inner sleeve is provided with multiple longitudinally extending support bars that support the outside of the rotary kiln cylinder.

4. The rotary kiln head sealing structure according to claim 1, characterized in that, The kiln inlet guard has a first connecting part, a second connecting part, and a third connecting part connected between the first connecting part and the second connecting part. The first connecting part is fixed to the rotary kiln cylinder by bolts, and the rear side of the second connecting part is provided with a slot that engages with the front end of the outer sleeve.

5. The rotary kiln head sealing structure according to claim 1, characterized in that, The rear annular cavity is provided with a second annular cold air box, and the second annular cold air box is provided with a second air source interface. The inner wall of the second annular cold air box is provided with a second nozzle with two ends that are respectively connected to the second annular cold air box and the rear annular cavity and face obliquely forward.

6. The rotary kiln head sealing structure according to claim 5, characterized in that, The rear annular cavity is a conical cavity with a narrow rear end and a wide front end.

7. The rotary kiln head sealing structure according to claim 1, characterized in that, The rear end of the first annular cold air box is fixed with heat-resistant steel fish scales pressed against the outer surface of the rotary kiln cylinder.

8. The rotary kiln head sealing structure according to claim 7, characterized in that, The rear end of the first annular cold air box is provided with a conical ring near the inner circle, and one end of the heat-resistant steel fish scale is fixed outside the conical ring.

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