Rotary kiln combustion chamber and helical flue structure thereof

Abstract

The application provides a rotary kiln combustion chamber and a spiral flue structure thereof, and belongs to the technical field of rotary kiln combustion chamber structure; the spiral flue is installed in the rotary kiln combustion chamber and comprises an upper flue and a lower flue; the upper flue is installed on the upper part of the combustion chamber, and the lower flue is installed on the lower part of the combustion chamber; the upper flue and the lower flue are connected with each other and jointly form a complete spiral flue gas passage. The rotary kiln combustion chamber structure provided by the application is beneficial to the heat release of flue gas in the high-temperature zone and the heat release of flue gas in the subsequent low-temperature zone under the condition that the working temperatures of different sections of the rotary kiln are different, so that the flue gas energy utilization efficiency is fully improved, and the energy loss in the use process of the rotary kiln is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of rotary kiln combustion chamber structure, and more specifically, relates to a rotary kiln combustion chamber and its spiral flue structure based on the ejector principle. Background Technology

[0002] The activated carbon activation furnace is a rotary kiln structure with a relatively long furnace cylinder and a low rotational speed. In a single-stage activation process, the process is divided into three stages from the kiln head to the kiln tail, with the temperature increasing sequentially in each stage. Traditional activation furnaces have exhaust outlets on both sides of the upper wall behind the combustion chamber. The combustion gas in the high-temperature stage, even after heating, still maintains a high temperature and is directly discharged from the exhaust outlet closest to one side, wasting a significant amount of energy and resulting in low energy utilization efficiency. Furthermore, some of the medium-temperature exhaust gas from the medium-temperature stage also exits from the high-temperature stage exhaust outlet. This inevitably leads to it being heated by the high-temperature stage flue gas, consuming even more heat from the high-temperature stage flue gas, further reducing energy utilization efficiency and increasing incremental energy consumption. Summary of the Invention

[0003] The purpose of this invention is to provide a rotary kiln combustion chamber and its spiral flue structure, which aims to solve the problems of low energy utilization efficiency and high energy consumption in the activation process of existing activated carbon activation furnaces by utilizing the ejector principle.

[0004] To achieve this objective, the solution adopted by the present invention is as follows:

[0005] A spiral flue structure is installed in the combustion chamber of a rotary kiln, comprising an upper flue and a lower flue. The upper flue is installed in the upper part of the combustion chamber, and the lower flue is installed in the lower part of the combustion chamber. The upper and lower flues are connected to each other to form a complete swirling flue gas passage.

[0006] The upper part of the flue is a spiral shape, and the flues are arranged at equal intervals in the upper part of the combustion chamber. The upper edge of the upper part of the flue is arc-shaped, and the lower edge is composed of an outer upper straight edge and a middle upper arc-shaped edge. The upper edge of the upper part of the flue is in close contact with the inner side of the upper part of the combustion chamber, and the upper straight edge is flush with the lower edge of the upper part of the combustion chamber.

[0007] The lower part of the flue is arranged at equal intervals in the lower part of the combustion chamber, which is similar to a baffle and forms a 90° angle with the side wall of the lower part of the combustion chamber. The upper edge of the lower part of the flue is composed of a lower straight edge section and a middle lower arc-shaped section. The lower straight edge section is flush with the upper edge of the lower part of the combustion chamber. The lower edge and side edge of the lower part of the flue are straight and closely attached to the inner wall of the lower part of the combustion chamber.

[0008] Preferably, the spacing between the lower sections of the flue is equal to half the pitch of the upper spiral of the flue.

[0009] Preferably, the upper straight edge segment overlaps with the lower straight edge segment at the front and rear, and the lower straight edge segment overlaps with the upper straight edge segment at the front and rear, forming a swirling flue gas channel, and the upper arc segment and the lower arc segment form a cylindrical cavity.

[0010] The present invention also discloses a rotary kiln combustion chamber, wherein the aforementioned spiral flue is installed. The combustion chamber is divided into upper and lower parts, the upper part of the combustion chamber is an arched structure, the lower part of the combustion chamber is a square structure, and the middle part is a furnace cylinder. The top side of the upper part of the combustion chamber has a "T"-shaped exhaust gas outlet and an ejector gas inlet. The ejector gas inlet is connected to a blower, which, based on the ejector principle, can draw the exhaust gas from the exhaust gas outlet out of the combustion chamber during operation. The lower part of the combustion chamber has equally spaced and staggered gas inlets.

[0011] Preferably, the upper part of the combustion chamber and the lower part of the combustion chamber are connected by bolts.

[0012] Preferably, the cylindrical cavity formed by the upper and lower arc segments, when combined with the furnace cylinder, can form a spiral-forward flue gas passage.

[0013] The beneficial effects of this invention are as follows: Compared with the prior art, for rotary kilns with segmented temperature control, such as a single-stage activated carbon activation furnace, this invention uses a blower to induce heat at the low-temperature section exhaust gas outlet, forming a low-pressure zone at the exhaust gas outlet. Even after the high-temperature exhaust gas in the high-temperature zone releases heat, it still possesses considerable heat and a high temperature. Driven by the pressure difference between the gas inlet and the exhaust gas outlet, it spirals forward within the spiral flue, continuing to release heat in the medium-temperature and low-temperature zones, fully utilizing the heat of the exhaust gas and improving energy utilization. Furthermore, the flue structure, which is in full contact with the combustion chamber, can replace the reinforcing rib structure in the original combustion chamber, achieving improved energy utilization without complicating the original combustion chamber structure. The lower part of the flue is perpendicular to the side wall of the combustion chamber, avoiding the spiral structure common to the upper part of the flue, thus preventing direct heating of the lower flue structure by the gas flame and increasing its service life. Moreover, the vertical arrangement is more conducive to the placement of refractory bricks in the lower part of the combustion chamber. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of a rotary kiln combustion chamber with a spiral flue provided in an embodiment of the present invention;

[0016] Figure 2This is a schematic diagram of the upper part of the spiral flue structure provided in an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the lower part of the spiral flue structure provided in an embodiment of the present invention;

[0018] In the diagram: 1. Upper part of combustion chamber; 2. Lower part of combustion chamber; 3. Upper part of flue; 4. Lower part of flue; 5. Gas inlet; 6. Injector gas inlet; 7. Exhaust gas outlet; 8. Furnace shell; 9. Upper edge of flue; 10. Upper straight edge section; 11. Upper arc section; 12. Lower straight edge section; 13. Lower arc section. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0020] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0021] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "a," "an," "a kind," "the," and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms "comprising," "including," "having," and any variations thereof used in this application are intended to cover non-exclusive inclusion; the terms "connected," "linked," "coupled," and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Multiple" used in this application means two or more. "And / or" describes the relationship between related objects, indicating that three relationships may exist; for example, "A and / or B" can represent: A alone, A and B simultaneously, and B alone. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of objects.

[0022] A spiral flue structure is installed in the combustion chamber of a rotary kiln, including an upper flue 3 and a lower flue 4. The upper flue 3 is installed in the upper part 1 of the combustion chamber, and the lower flue 4 is installed in the lower part 2 of the combustion chamber. The upper flue 3 and the lower flue 4 are connected to each other to form a complete swirling flue gas passage.

[0023] In some preferred embodiments, the upper part 3 of the flue is a spiral semi-spiral shape, and is arranged at equal intervals in the upper part 1 of the combustion chamber. The upper edge 9 of the upper part of the flue is arc-shaped, and the lower edge is composed of an outer upper straight edge segment 10 and a middle upper arc-shaped segment 11. The upper edge 9 of the upper part of the flue is in close contact with the inner side of the upper part of the combustion chamber, and the upper straight edge segment 10 is flush with the lower edge of the upper part 1 of the combustion chamber.

[0024] In some preferred embodiments, the lower flue 4 is arranged at equal intervals within the lower combustion chamber 2, acting as a baffle, and forms a 90° angle with the side wall of the lower combustion chamber 2. The upper edge of the lower flue 4 is composed of a lower straight edge segment 12 and a middle lower arc segment 13, with the lower straight edge segment 12 flush with the upper edge of the lower combustion chamber 2. The lower edge and side edges of the lower flue 4 are straight and closely adhere to the inner wall of the lower combustion chamber 2.

[0025] In some preferred embodiments, the spacing between the lower 4 sections of the flue is equal to half the pitch of the upper 3 spiral section of the flue.

[0026] In some preferred embodiments, the upper straight edge segment 10 overlaps with the front and rear lower straight edge segments 12 respectively, and the lower straight edge segment 12 overlaps with the front and rear upper straight edge segments 10 respectively, forming a swirling flue gas channel, and the upper arc segment 11 and the lower arc segment 13 form a cylindrical cavity.

[0027] The present invention also discloses a rotary kiln combustion chamber, wherein the aforementioned spiral flue is installed. The combustion chamber is divided into upper and lower parts. The upper part 1 of the combustion chamber has an arched structure, and the lower part 2 of the combustion chamber has a square structure with a furnace cylinder 8 in the middle. The top side of the upper part 1 of the combustion chamber has a "T"-shaped exhaust gas outlet 7 and an ejector gas inlet 6. The ejector gas inlet 6 is connected to a blower. When it is working, it can draw the exhaust gas in the chamber out of the combustion chamber from the exhaust gas outlet 7 based on the ejector principle. The lower part 2 of the combustion chamber has equally spaced and staggered gas inlets 5.

[0028] In some preferred embodiments, the upper part 1 of the combustion chamber and the lower part 2 of the combustion chamber are connected by bolts.

[0029] In some preferred embodiments, the cylindrical cavity formed by the upper arc segment 11 and the lower arc segment 13, when combined with the furnace tube 8, can form a spiral-forward flue gas passage.

[0030] Specifically, when the combustion chamber is working, the gas enters from the gas inlet 5 and is ignited to form a flame, which raises the temperature of the atmosphere in the combustion chamber and heats the furnace drum 8. The part of the combustion chamber away from the exhaust gas outlet is the high-temperature zone, and the flue gas produced by the combustion of the gas is even hotter. Unlike the combustion chamber of a traditional activated carbon activation furnace, which also has an exhaust gas outlet at the top of the high-temperature zone, this invention only has an exhaust gas outlet 7 at the top of the low-temperature zone.

[0031] Even after releasing heat, the high-temperature flue gas in the high-temperature zone still retains a large amount of heat. Furthermore, due to the continuous entry of combustion gas from the gas inlet 5, a local high-pressure zone will be created near the gas inlet 5. After the ejector gas inlet 6 is connected to the blower, an ejector gas flow is formed. According to Bernoulli's principle, a low-pressure zone will be formed near the exhaust gas outlet 7 in the upper part of the combustion chamber 1. This pressure difference serves as the driving force for the high-temperature flue gas to spiral forward in the spiral flue, and it continuously releases heat through the medium-temperature zone and the low-temperature zone. The medium-temperature flue gas in the medium-temperature zone will also spiral forward under this pressure difference and release heat through the low-temperature zone. The design of the spiral flue ensures that the flue gas can only enter through the gas inlet 5, spiral forward in the flue to the exhaust gas outlet 7, and leave the rotary kiln combustion chamber under the carry of the ejector gas flow.

[0032] The flue structure is in full contact with the combustion chamber, replacing the original reinforcing ribs in the combustion chamber. This improves energy efficiency without complicating the original combustion chamber structure. The lower part 4 of the flue is perpendicular to the side wall of the combustion chamber at the lower part 2. The absence of a spiral structure avoids direct heating of the lower part 4 by the flame at the gas inlet 5, increasing its service life. Furthermore, the vertical arrangement is more conducive to the placement of refractory bricks in the lower part 2 of the combustion chamber.

[0033] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0034] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A spiral flue structure, installed in the combustion chamber of a rotary kiln, characterized in that: It includes an upper part (3) of the flue and a lower part (4) of the flue. The upper part (3) of the flue is installed in the upper part (1) of the combustion chamber, and the lower part (4) of the flue is installed in the lower part (2) of the combustion chamber. The upper part (3) of the flue and the lower part (4) of the flue are connected to each other and together form a complete swirling flue gas passage. The upper part (3) of the flue is a spiral semi-spiral shape, and is arranged at equal intervals in the upper part (1) of the combustion chamber. The upper part (3) of the flue includes the upper edge (9) of the upper part of the flue. The upper edge (9) of the upper part of the flue is arc-shaped, and the lower edge is composed of an outer upper straight edge segment (10) and a middle upper arc-shaped segment (11). The upper edge (9) of the upper part of the flue is in close contact with the inner side of the upper part (1) of the combustion chamber, and the upper straight edge segment (10) is flush with the lower edge of the upper part (1) of the combustion chamber. The lower part (4) of the flue is arranged at equal intervals in the lower part (2) of the combustion chamber, and forms an angle of 90° with the side wall of the lower part (2) of the combustion chamber. The upper edge of the lower part (4) of the flue is composed of a lower straight edge section (12) and a middle lower arc section (13). The lower straight edge section (12) is flush with the upper edge of the lower part (2) of the combustion chamber. The lower edge and side edge of the lower part (4) of the flue are straight and closely attached to the inner wall of the lower part (2) of the combustion chamber.

2. The spiral flue structure according to claim 1, characterized in that: The spacing between the sections of the lower part (4) of the flue is equal to half the pitch of the spiral of the upper part (3) of the flue.

3. The spiral flue structure according to claim 1, characterized in that: The upper straight edge segment (10) overlaps with the lower straight edge segment (12) at the front and rear, and the lower straight edge segment (12) overlaps with the upper straight edge segment (10) at the front and rear, forming a swirling flue gas channel.

4. The spiral flue structure according to claim 1, characterized in that: The upper arc segment (11) and the lower arc segment (13) form a cylindrical cavity.

5. A rotary kiln combustion chamber equipped with the spiral flue structure according to any one of claims 1-4, characterized in that: The upper part (1) of the combustion chamber is an arched structure, the lower part (2) of the combustion chamber is a square structure, and the middle part is a furnace tube (8); the top side of the upper part (1) of the combustion chamber has a "T"-shaped exhaust gas outlet (7) and an ejector gas inlet (6), and the ejector gas inlet (6) is connected to a blower; the lower part (2) of the combustion chamber has gas inlets (5) that are equally spaced and staggered.

6. The rotary kiln combustion chamber according to claim 5, characterized in that: The upper part (1) of the combustion chamber and the lower part (2) of the combustion chamber are connected by bolts.

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