A tunnel kiln structure with an external air duct

Abstract

This invention provides a tunnel kiln structure with an external air duct. The external air duct allows natural air to bypass the bricks in the reduction zone and directly enter the high-temperature firing zone, satisfying the oxygen requirements for sintering while avoiding disruption of the oxygen-deficient reduction environment in the cooling reduction section. The sealed box structure, consisting of a reduction zone made of a preferred high thermal conductivity metal and partition doors, forms a stable oxygen-deficient environment chamber from the reduction zone to the kiln outlet, ensuring that the brick blanks complete reduction cooling under oxygen-free conditions. This eliminates the need for a crane cover system, directly saving on equipment investment and maintenance costs. Preheating the natural air by the outer surface of the reduction zone effectively prevents irreversible damage to the finished product from cold air shocks. Furthermore, the absence of airflow within the reduction zone allows for pressure balance, creating a stable oxygen-deficient reduction cooling environment without the need for additional pressure regulating devices. Continuous feeding and discharging and chamber sealing can be maintained through at least one partition door, ultimately achieving the technical effects of reduced brick firing costs, increased production capacity, and no new pollution.

Description

Technical Field

[0001] This utility model relates to the field of blue brick firing technology, and in particular to a tunnel kiln structure with an external air duct. Background Technology

[0002] Blue bricks, as a traditional building material, are widely used in the restoration of ancient buildings and high-end construction due to their durability and aesthetic value. Traditional blue brick firing uses ancient kilns (such as horseshoe kilns), where a reducing atmosphere is created by high-temperature sintering followed by water seepage to produce the blue color. However, this method suffers from serious pollution emissions (coal / firewood combustion produces large amounts of sulfides and particulate matter), long production cycles (single kiln firing takes approximately 15-30 days), extremely low output (limited kiln capacity), and high costs, making blue bricks unable to meet the large-scale demands of modern construction.

[0003] To improve efficiency, existing technologies attempt to adopt continuous production using tunnel kilns. However, the traditional tunnel kiln design has a fundamental flaw: its air duct system forces cooling airflow through the fired brick blanks, causing the bricks to cool in an oxygen-rich environment to form red bricks. Although some improved solutions involve adding a movable sealed cover to the high-temperature section to isolate oxygen, and then using an overhead crane to move the cover to remove the bricks from the kiln, this solution requires heavy-duty overhead crane equipment, customized high-temperature resistant covers (which are costly and have a short lifespan), and frequent lifting operations (which are labor-intensive), and also results in thermal efficiency loss due to the kiln opening.

[0004] In addition, existing tunnel kiln brick technology is generally limited by small cross-section design (usually ≤3 meters) and relies on natural gas or coal-to-gas conversion (high energy costs and coal-to-gas pollution still exist), resulting in low production capacity, insufficient stability, and inability to achieve large-section continuous production.

[0005] In summary, existing brick-making techniques have four common defects:

[0006] Production capacity bottlenecks: low output from traditional kilns and limited cross-sectional area of ​​tunnel kilns;

[0007] High costs: reliance on expensive energy or heavy auxiliary equipment;

[0008] Environmental drawbacks: Traditional methods cause heavy pollution, and the cleanliness of coal-to-gas conversion is insufficient;

[0009] Unstable process: The operation of moving the enclosure is complicated and the control of the reducing atmosphere is difficult.

[0010] Therefore, there is an urgent need to develop a brick tunnel kiln firing technology that is compatible with large cross sections, continuous production, low cost, and environmentally friendly. Utility Model Content

[0011] The purpose of this invention is to provide a tunnel kiln structure with an external air duct to solve the problems existing in the prior art.

[0012] To achieve the above objectives, this utility model provides the following solution:

[0013] This utility model provides a tunnel kiln structure with an external air duct, comprising:

[0014] The tunnel kiln body has an inlet at one end and an outlet at the other end. Both the inlet and outlet are equipped with partition doors to prevent outside air from entering the kiln.

[0015] The reduction zone is located inside the tunnel kiln body, with one end close to the high-temperature annealing section and the other end at the kiln outlet. The reduction zone has at least one partition door.

[0016] An external air duct is provided on the side and / or top of the tunnel kiln body and communicates with the outside of the reduction zone.

[0017] Preferably, the tunnel kiln body is further provided with a preheating zone, and a roasting zone is provided at the rear end of the preheating zone.

[0018] Preferably, the reduction zone is made of a high thermal conductivity metal material.

[0019] Preferably, the external air duct is arranged along the length of the tunnel kiln body.

[0020] Preferably, the reduction zone is equipped with a water spray device or an air jet device to accelerate the cooling of the finished product.

[0021] Preferably, the reduction zone is provided with a combustible material inlet, which is used to use carbon monoxide gas generated in a high-temperature and oxygen-deficient environment to carry out a reduction reaction on the finished product to achieve the purpose of color adjustment.

[0022] The present invention achieves the following beneficial technical effects compared to the prior art:

[0023] This utility model provides a tunnel kiln structure with an external air duct. The external air duct allows natural air to bypass the bricks in the reduction zone and directly enter the high-temperature firing zone, satisfying the oxygen requirements for sintering while avoiding damage to the oxygen-deficient reduction environment of the cooling reduction section. The reduction zone, preferably made of a high thermal conductivity metal, and the sealed box structure composed of partition doors form a stable oxygen-deficient environment chamber from the reduction zone to the kiln outlet, ensuring that the brick blanks complete reduction and cooling under oxygen-free conditions. This eliminates the need for a crane cover system, directly saving equipment investment and maintenance costs. The natural air preheating of the reduction zone surface effectively prevents irreversible damage to the finished product caused by cold air shock. Furthermore, the absence of air circulation in the reduction zone allows for pressure balance operation, creating a stable oxygen-deficient reduction and cooling environment without the need for additional pressure regulating devices. Continuous feeding and discharging and chamber sealing can be maintained through at least one partition door, ultimately achieving the technical effects of reduced brick firing costs, increased production capacity, and no new pollution. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a tunnel kiln structure with an external air duct provided by this utility model. Detailed Implementation

[0026] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] The purpose of this invention is to provide a tunnel kiln structure with an external air duct to solve the problems existing in the prior art.

[0030] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1:

[0032] This embodiment provides a tunnel kiln structure with an external air duct, such as Figure 1 As shown, it includes:

[0033] The tunnel kiln body 1 has an inlet 2 at one end and an outlet 3 at the other end. Both ends of the kiln body are equipped with partition doors 4 to prevent outside air from entering the kiln.

[0034] The reduction zone 5 is located inside the tunnel kiln body 1, with one end close to the high-temperature annealing section and the other end at the kiln outlet 3. The reduction zone 5 has at least one partition door 4.

[0035] External air duct 6 is located on the side of the tunnel kiln body 1 and communicates with the outside of the reduction zone 5. Of course, in other embodiments, external air duct 6 can also be located on the top, side and top of the tunnel kiln body 1.

[0036] The tunnel kiln body 1 in this embodiment is basically the same as the existing tunnel kiln structure for firing blue bricks. It can burn solid waste, produce environmentally friendly solid waste mud, or produce high-quality clay blue bricks made from clay. The difference lies in the creative combination design of the reduction zone 5, the partition door 4, and the external air duct 6 proposed in this application. The external air duct allows natural air to bypass the blue bricks in the reduction zone and directly enter the high-temperature firing zone, which satisfies the oxygen requirement for sintering and avoids oxidation in the cooling section. The sealed box structure composed of the reduction zone and the partition door, made of high thermal conductivity metal, forms a stable oxygen-deficient environment chamber from the reduction zone to the kiln outlet, ensuring that the brick blanks complete the reduction and cooling under oxygen-free conditions.

[0037] As one implementation method, the tunnel kiln body 1 is also provided with a preheating zone 7, and a firing zone 8 is provided at the rear end of the preheating zone 7 for preheating and high-temperature sintering of the brick blanks.

[0038] In one implementation, the external air duct 6 is located between the roasting zone 8 and the reduction zone 5. In this way, natural air can cool the outside of the reduction zone 5, and the cooling process can also preheat the area to supply oxygen to the roasting zone 8, achieving a dual effect. Of course, other oxygen supply methods can be designed according to the actual needs of the manufacturer. In addition, in this embodiment, the external air duct 6 is located at the rear of the tunnel kiln body 1. Of course, in other embodiments, the external air duct 6 can also be located at the front. As long as it can play the role of cooling and oxygen supply, it is within the protection scope of this patent.

[0039] As one implementation method, the reduction zone 5 is preferably made of a metal with high thermal conductivity to achieve rapid heat dissipation. Of course, any other material can be used in other embodiments.

[0040] As one implementation method, the external air duct 6 is arranged parallel to the length of the tunnel kiln body 1, and its cross-section is a rectangular or annular pipe, thereby maximizing the heat exchange area without increasing the volume of the tunnel kiln body 1.

[0041] As one implementation, the reduction zone 5 is equipped with a water spray device or an air jet device to accelerate the cooling of the finished product, or it can be allowed to cool naturally without the water spray device or air jet device.

[0042] As one implementation method, the reduction zone 5 is equipped with a combustible material inlet. The carbon monoxide gas generated in the high-temperature and oxygen-deficient environment is used to reduce the finished product to achieve the purpose of color adjustment. When the color is good, there is no need to put combustible materials in. The inlet can be provided or not.

[0043] This utility model provides a tunnel kiln structure with an external air duct, which has the following four core advantages:

[0044] 1. Eliminating the overhead crane cover system directly saves on equipment investment and maintenance costs;

[0045] 2. Compatible with any cross-sectional size, the external air duct avoids occupying space inside the kiln; at the same time, it allows air to bypass the reduction zone and directly enter the roasting zone, ensuring a stable reduction atmosphere in the reduction zone;

[0046] 3. Utilize natural wind for preheating (heating up the metal casing by dissipating heat and then introducing air) to prevent cold air from damaging the billet;

[0047] 4. Self-balancing air pressure operation (no additional pressure regulating device required). Continuous material feeding and discharging, as well as chamber sealing, can be maintained by alternating opening and closing of the partition door and kiln door. Ultimately, this achieves the technical effect of reducing the cost of brick firing, increasing production capacity, and eliminating new pollution, completely overcoming the shortcomings of the previous technology.

[0048] 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 are 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.

[0049] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0050] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A tunnel kiln structure with an external air duct, characterized in that: include: The tunnel kiln body has an inlet at one end and an outlet at the other end. Both the inlet and outlet are equipped with partition doors to prevent outside air from entering the kiln. The reduction zone is located inside the tunnel kiln body, with one end near the high-temperature annealing section and the other end at the kiln outlet. The reduction zone has at least one partition door. An external air duct is provided on the side and / or top of the tunnel kiln body and communicates with the outside of the reduction zone.

2. The tunnel kiln structure with an external air duct according to claim 1, characterized in that: The tunnel kiln body is also provided with a preheating zone, and a roasting zone is provided at the rear end of the preheating zone.

3. The tunnel kiln structure with an external air duct according to claim 1, characterized in that: The reduction zone is made of a high thermal conductivity metal.

4. The tunnel kiln structure with an external air duct according to claim 1, characterized in that: The external air duct is arranged along the length of the tunnel kiln body.

5. The tunnel kiln structure with an external air duct according to claim 1, characterized in that: The reduction zone is equipped with a water spray device or an air jet device to accelerate the cooling of the finished product.

6. The tunnel kiln structure with an external air duct according to claim 1, characterized in that: The reduction zone is equipped with a combustible material inlet, which is used to utilize carbon monoxide gas generated in a high-temperature, oxygen-deficient environment to reduce the finished product and achieve the purpose of color adjustment.

Images