A large chamber covered ring type calcining furnace

Abstract

This invention relates to the field of high-temperature roasting, specifically a large-cavity, covered, ring-type roasting furnace. It includes a furnace chamber surrounded by a furnace shell and a furnace hood covering the top. The furnace chamber contains a furnace cavity, which is separated from the furnace shell by partition walls at its front and back, and from the furnace shell by side walls at its left and right. Each partition wall has a cavity within it, and both ends of the partition wall are connected to the side walls. A group of evenly spaced supports is distributed at the bottom of the furnace cavity, and a roasting surface is provided on top of the support groups. This invention enables the low-energy production of carbon products of different specifications using a covered roasting furnace. This furnace type offers high production flexibility, excellent thermal performance, stable and reliable structure, good insulation, high thermal energy utilization, and low operating and maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of high-temperature roasting technology, and in particular to a large-cavity covered ring roasting furnace. Background Technology

[0002] Currently, carbon roasting production removes volatiles from green materials through indirect heating with high-temperature flue gas, with roasting temperatures typically ranging from 900 to 1150°C. In existing technologies, most roasting equipment utilizes a roasting furnace, particularly the covered ring roasting furnace, which is widely used in the roasting of carbon products. Traditional covered ring roasting furnaces employ a fixed-size feed hopper, the dimensions of which must be determined during the initial construction phase based on the planned specifications of the green materials to be roasted. Due to the fixed feed hopper size, traditional covered ring roasting furnaces lack production flexibility. When market demand shifts to larger or more diverse products, the equipment struggles to adapt, hindering the market responsiveness of manufacturers and reducing the return on investment due to decreased utilization. Therefore, a covered ring roasting furnace that eliminates the intermediate feed hopper checker bricks has emerged, aiming to flexibly adapt to the production needs of products with different specifications.

[0003] The prior art has the following publication number: CN120062986A The "covered ring-type roasting furnace" comprises a furnace body and a furnace cover, the furnace cover being located on top of the furnace body, and also includes a peripheral wall, a first flue gas passage, and a second flue gas passage. Several furnace bodies are connected in a ring, and each furnace body has a material cavity, in which several saggers are stacked. The peripheral wall includes a partition wall and a side wall. Two horizontally adjacent material cavities are separated by a partition wall and a fire well wall. The first flue gas passage is located within the fire well wall, and the second flue gas passage is located at the bottom of the partition wall. Two horizontally adjacent material cavities are connected by the first flue gas passage and the second flue gas passage. This effectively solves the problem of high heat loss and high product energy consumption caused by the large amount of material at the bottom of the existing covered ring-type roasting furnace.

[0004] However, this type of covered ring-type roasting furnace only eliminates the checker bricks of the traditional covered ring-type roasting furnace in terms of structure, but fails to systematically solve the following problems: 1) For furnace types that eliminate both the bottom surface bricks and supports, the steel sagger is placed directly at the bottom of the furnace, resulting in uneven heating of the bottom of the sagger and affecting the product qualification rate; 2) For furnace types that retain the supports but eliminate the surface bricks, the damaged parts of the steel sagger after oxidation are prone to fall into the gaps between the supports, increasing the difficulty of cleaning the furnace chamber; 3) Because this type of furnace eliminates the checker bricks, its partition walls and side walls lack support in some areas, which can easily cause tilting during production. Summary of the Invention

[0005] The purpose of this invention is to provide a large-cavity covered ring-type roasting furnace to solve the problems mentioned in the background art: 1) For furnace types where the bottom surface bricks and supports are eliminated, the steel sagger is placed directly at the bottom of the furnace, resulting in uneven heating of the bottom of the sagger and affecting the product qualification rate; 2) For furnace types that retain supports but eliminate surface bricks, the damaged parts of the steel sagger after oxidation are prone to fall into the gaps between the supports, increasing the difficulty of cleaning the furnace chamber; 3) Because this type of furnace eliminates the checker bricks, its partition walls and side walls lack local support, which can easily cause tilting problems during production.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A large-cavity covered ring-type roasting furnace includes a furnace chamber surrounded by a furnace shell and a furnace hood covering the top. The furnace chamber is provided with a furnace cavity. The front and back of the furnace cavity are separated by partition walls, and the left and right sides of the furnace cavity are separated from the furnace shell by side walls. The partition walls have cavities inside, and the two ends of the partition walls are connected to the side walls. The bottom of the furnace cavity is evenly distributed with a group of supports, and the upper part of the support group is provided with a kang (roasting surface).

[0008] Preferably, expansion joints are provided between the two ends of the partition wall and the side wall.

[0009] Preferably, the partition wall is provided with partition wall supports composed of irregularly shaped refractory bricks at its lower part, and the partition wall supports are arranged longitudinally at intervals.

[0010] Preferably, two or more furnace cavities are connected in series longitudinally, and the furnace cavities are separated by the partition wall and the partition wall support. The front side of the first furnace cavity in series is provided with a connecting fire channel. The connecting fire channel is made of irregularly shaped refractory bricks in the shape of an arch, with one end built on the bottom of the furnace and the other end built on the partition wall support.

[0011] Preferably, an anchor is provided between the furnace shell and the side wall.

[0012] Preferably, the cavity includes a first cavity and a second cavity forming a closed double-loop structure, the first cavity is filled with heat-insulating and refractory material, and the second cavity is a hollow fire well.

[0013] Preferably, the support group is composed of irregularly shaped refractory bricks, which are evenly distributed at intervals on the bottom surface of the furnace.

[0014] Preferably, the kang surface includes a first layer, a second layer, and a third layer composed of irregularly shaped refractory bricks arranged from bottom to top. The first layer is disposed on the support group and arranged longitudinally at intervals. The second layer is arranged laterally at intervals and covers the gaps in the first layer. The third layer is arranged longitudinally at intervals and covers the gaps in the second layer.

[0015] Preferably, the sidewall is composed of alternating shaped refractory bricks, insulating bricks, and refractory fibers, or is composed of refractory fibers.

[0016] Preferably, the anchor consists of an expansion bolt and a hook, with the expansion bolt inserted into the furnace shell and the tail of the hook located on the side wall.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. Excellent thermal performance: The three-dimensional, uniformly distributed flue gas circulation system, consisting of "furnace inlet heating → flue gas at the bottom of the support group → uniformly distributed channel on the kang surface → fire pit in the partition wall → negative pressure vacuum at the furnace outlet", eliminates the fixed-size grid brick box and forms a large, continuous furnace cavity. It can flexibly accommodate saggers of different specifications, especially large-sized products, which greatly adapts to the changing market demand. The composite insulation design adopted on the non-fire pit side of the side wall and partition wall reduces heat loss from the furnace body and improves thermal efficiency. At the same time, the partition wall with a closed double-loop structure ensures that the high-temperature flue gas is evenly distributed in the furnace cavity, thereby improving the quality consistency of the roasted products and reducing energy consumption.

[0019] 2. Easy to clean the kang surface: The first, second, and third layers of the kang surface are arranged in a staggered pattern, and together with the evenly distributed support groups at the bottom, a flue gas circulation channel is formed, ensuring stable heat transfer. Because the vertical spacing of the third layer of the kang surface covers the gaps in the horizontal spacing of the second layer, and the horizontal spacing of the second layer covers the gaps in the vertical spacing of the first layer, the bottom of the sagger placed at the bottom of the furnace is heated evenly, and the shavings from the sagger firing fall onto the first layer of the kang surface, which is easier to clean than the shavings falling onto the bottom of the furnace.

[0020] 3. Stable and Reliable Structure: The integral furnace shell ensures the external stability of the entire furnace chamber, and the one-piece furnace shell reduces heat loss. The left and right inner sides of the furnace shell are constructed with high-temperature resistant and energy-saving environmentally friendly materials, while the front and rear inner sides of the furnace shell are constructed with partition walls made of irregularly shaped refractory bricks with vertical and horizontal tenon and mortise joints. The partition walls are located inside the furnace chamber, separating the front and rear series furnace chambers. Since the partition walls bear the heat transfer of the entire series of furnace chambers, a first cavity and a second cavity are set inside the partition walls. The first cavity is filled with heat-insulating refractory material, and the tenon and mortise structure of the irregularly shaped refractory bricks can maintain stability under high-temperature thermal expansion and contraction, and has a certain load-bearing capacity. Therefore, the furnace hood is supported on the top of the front and rear first cavities. The second cavity is hollow inside, and a gap is left between the top and the furnace hood to facilitate the heat transfer of flue gas. At the same time, the partition walls are embedded in the side walls, and expansion joints are left at the junction of the two to accommodate the thermal expansion and contraction of the irregularly shaped bricks. Anchors are provided between the side walls and the furnace chamber, which further enhances the stability of the entire furnace chamber and extends the service life of the furnace body. Attached Figure Description

[0021] Figure 1 This is a longitudinal cross-sectional view of the series furnace cavity of the present invention;

[0022] Figure 2 This is a multi-view cross-sectional view of the present invention;

[0023] Figure 3 This is an enlarged schematic diagram of the three-dimensional structure of the kang (heated brick bed) surface of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of the furnace shell, side walls, supports, kang surface and anchors of the present invention.

[0025] In the diagram: 1. Furnace shell, 1-1. Furnace chamber, 1-2. Furnace cavity, 2. Partition wall, 3. Side wall, 4. Support group, 5. kang surface, 5-1. First layer structure, 5-2. Second layer structure, 5-3. Third layer structure, 6. Connecting fire channel, 7. Anchor, 8. Partition wall support, 9. Furnace cover, 10. Cavity, 10-1. First cavity, 10-2. Second cavity. Detailed Implementation

[0026] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention.

[0027] Figure 1 The cross section cut at position AA shown is... Figure 2 The cross-section of AA corresponds to, Figure 1 The cross section at the position of BB shown is... Figure 2 Corresponding to the cross-section of BB, the irregular refractory bricks in this invention are existing brick types for making roasting furnaces. Different irregular refractory bricks can be selected according to different components and functions, such as partition walls, side walls, support groups, kang surfaces, connecting fire channels, and partition wall supports, etc.

[0028] Example 1, see Figures 1-4 As shown.

[0029] This embodiment describes a large-cavity covered ring-type roasting furnace, comprising a furnace chamber 1-1 surrounded by a furnace shell 1 and a furnace cover 9 covering the top. The furnace chamber 1-1 contains a furnace cavity 1-2, which is separated from the furnace shell 1 by a partition wall 2 at the front and back. The furnace cavity 1-2 is separated from the furnace shell 1 by side walls 3 at the left and right. The partition wall 2 contains a cavity 10, and the two ends of the partition wall 2 are connected to the side walls 3. The bottom of the furnace cavity 1-2 is evenly distributed with support groups 4, and the upper part of the support groups 4 is provided with a kang surface 5.

[0030] The intervals of the support group 4 form a flue gas circulation channel, which facilitates heat transfer, and the kang surface 5 makes it easy to clean up waste residue.

[0031] Expansion joints are left between the two ends of the partition wall 2 and the side wall 3. The partition wall 2 is provided with partition wall supports 8 composed of irregularly shaped refractory bricks with vertical and horizontal tenons at the bottom. The partition wall supports 8 are arranged longitudinally at intervals.

[0032] Two or more furnace chambers 1-2 are connected in series longitudinally. The furnace chambers 1-2 are separated by the partition wall 2 and the partition wall support 8. The front side of the first furnace chamber 1-2 in series is provided with a connecting fire channel 6. The connecting fire channel 6 is made of irregular refractory bricks in the shape of an arch, with one end built on the bottom of the furnace and the other end built on the partition wall support 8.

[0033] It also includes anchors 7, one end of which is located on the inner wall of the furnace shell 1, and the other end of which is connected to the corresponding position of the side wall 3; the cavity 10 includes a first cavity 10-1 and a second cavity 10-2 forming a closed double-loop structure, the first cavity 10-1 is filled with heat-insulating refractory material, and the second cavity 10-2 is a hollow fire pit; the support group 4 is composed of irregularly shaped refractory bricks, which are evenly distributed on the bottom surface of the furnace; the side wall 3 is composed of irregularly shaped refractory bricks with vertical and horizontal tenons, heat-insulating bricks and refractory fibers interlaced, or is composed of refractory fibers.

[0034] Several large furnace chambers 1-1 can be arranged in parallel according to production needs. Then, the furnace chambers 1-2 connected in series are connected to transfer heat energy through the connecting flue 6. The entire series furnace chamber group is externally connected to a negative pressure vacuum device to guide the direction of the flow of hot flue gas. The heat energy of the heat source of the series furnace chamber group enters from the connecting flue 6. The partition wall supports 8 are also made of irregular refractory bricks, which are evenly distributed at the bottom of the partition wall 2. They can support the partition wall 2 and connect the bottom flue and the hollow fire pit. Then, the gap formed by the longitudinal spacing of the partition wall supports 8 under the left partition wall 2 is used as a flue gas channel to transfer the hot flue gas to the second cavity 10-2 inside the partition wall 2. Then, through the gap formed by the top of the second cavity 10-2 and the furnace cover 9, the hot flue gas flows from top to bottom into the furnace chamber 1-2. Combined with the gap formed by the bottom support group 4, the top and bottom of the entire furnace chamber 1-2 are evenly distributed with flue gas and uniformly heated.

[0035] Then, guided by negative pressure, the hot flue gas flows through the gaps formed by the bottom support group 4 and the partition wall support 8 under the right partition wall 2 to the second cavity 10-2 of the right partition wall 2. It then rises along the wall and flows through the gap formed with the top furnace hood 9 to the furnace cavity 1-2 of the next furnace chamber 1-1 connected in series. This ultimately improves the thermal energy utilization rate of the hot flue gas, which can expand the production scale at a very low cost while achieving the goal of energy saving.

[0036] The entire furnace chamber 1-1 is enclosed and separated by an integrated furnace shell 1, which reduces heat loss. Each furnace chamber is separated from the furnace shell 1 by partition walls 2 at the front and back, and from the furnace shell 1 by side walls 3 on both sides. The bottom is supported by a group of evenly distributed supports 4. The support group 4 is composed of refractory bricks with vertical and horizontal tenons. Refractory bricks with vertical and horizontal tenons do not require cement reinforcement during construction and can adapt to thermal expansion and contraction under high temperature conditions, ensuring the stability of the overall structure. Each support in the support group 4 has the same structural shape and is evenly distributed on the bottom surface of the furnace, forming a flue gas flow channel at the bottom of the furnace. The partition walls 2 and side walls 3 are made of high-temperature resistant and energy-saving environmentally friendly materials. The partition walls 2 are also embedded in the side walls 3 and have expansion joints, which allows the entire furnace chamber 1-1 to maintain stability under high temperature conditions. The partition walls 2 have a closed double-loop structure. The first cavity 10-1 is filled with insulation material, and the second cavity 10-2 forms a uniformly sized fire pit as a vertical flame channel. The combination of the two can balance structural strength and insulation performance.

[0037] The side wall 3 can be composed of irregularly shaped refractory bricks, heat-insulating bricks and refractory fibers with vertical and horizontal tenons, or it can be composed of refractory fibers. The connection between the anchor 7 and the irregularly shaped refractory bricks or refractory fibers of the side wall 3 can enhance the integrity and stability of the furnace body masonry structure.

[0038] Example 2, see Figures 1-4 As shown.

[0039] This embodiment describes a large-cavity covered ring-type roasting furnace, comprising a furnace chamber 1-1 surrounded by a furnace shell 1. The furnace chamber 1-1 contains a furnace cavity 1-2. The front and rear of the furnace cavity 1-2 are separated by a partition wall 2, and the two sides of the furnace cavity 1-2 are separated from the furnace shell 1 by side walls 3. The two ends of the partition wall 2 are respectively embedded in the side walls 3. A group of supports 4 is evenly distributed at the bottom of the furnace cavity. A kang surface 5 is provided on the upper part of the support group 4. The kang surface 5 includes a first layer structure 5-1, a second layer structure 5-2, and a third layer structure 5-3 composed of irregularly shaped refractory bricks arranged from bottom to top. The first layer structure 5-1 is disposed on the support group 4 and arranged longitudinally at intervals. The second layer structure 5-2 is arranged laterally at intervals and covers the gaps in the first layer structure 5-1. The third layer structure 5-3 is arranged longitudinally at intervals and covers the gaps in the second layer structure 5-2.

[0040] The kang surface 5 above the support group 4 forms the bottom of the furnace chamber, used to support the saggers containing products and insulation materials. The kang surface 5 is made of irregularly shaped refractory bricks with vertical and horizontal tenons. The first layer structure 5-1, the second layer structure 5-2, and the third layer structure 5-3 of the kang surface are arranged in a staggered pattern, and together with the evenly distributed support group 4 at the bottom, a flue gas circulation channel is formed, ensuring stable heat transfer. Because the vertical spacing of the third layer structure 5-3 of the kang surface 5 covers the horizontal spacing of the second layer structure 5-2, and the horizontal spacing of the second layer structure 5-2 covers the vertical spacing of the first layer structure 5-1, the bottom of the sagger placed at the bottom of the furnace is heated evenly in the third layer structure 5-3, and the waste residue from the sagger firing will fall onto the first layer structure 5-1 of the kang surface 5, which is easier to clean than the waste residue falling at the bottom of the furnace.

[0041] The cross-section of the irregular refractory bricks used in the first layer structure 5-1 is Z-shaped, but the two ends of each column are flat. The brick joints are located on the supports of the support group 4. This layer is arranged longitudinally at intervals and serves as the bottom layer of the load-bearing benchmark for the entire kang surface. Its Z-shaped cross-section is specifically designed to bear the static heavy load of the material above, the reciprocating pressure of the firing equipment, and the high-temperature alternating mechanical impact load. It is suitable for large furnace cavities and large-span unsupported paving scenarios. At the same time, the Z-shaped tenon and groove structure is used to directionally divert and release the concentrated thermal stress throughout the entire area, blocking the transmission and diffusion of thermal stress to the upper layer. This avoids the failure of the entire kang surface to crack, sink, and collapse from the source, and builds a solid foundation for the long-term service of the entire structure, solving the shortcomings of the existing single-layer structure in terms of pressure resistance and crack resistance.

[0042] The longitudinal section of the irregularly shaped refractory bricks used in the second layer structure 5-2 is... Figure 3 The T-shaped structure is arranged laterally and sandwiched between the first layer structure 5-1, which bears the load at the bottom, and the third layer structure 5-3, which is the working structure at the top. The two ends of the T-shape of the second layer structure 5-2 are set on the two rows of irregularly shaped bricks arranged longitudinally in the first layer structure 5-1, and the lower end of the T-shape of the second layer structure 5-2 is set in the gap between the two rows of irregularly shaped bricks arranged longitudinally in the first layer structure 5-1. The size of the lower end of the T-shape of the second layer structure 5-2 should preferably be adapted to the size of the gap. Therefore, this layer structure is different from the disordered heat conduction defects of the existing single-layer kang surface. This layer can accurately block the direct leakage of local instantaneous high-temperature heat sources in the furnace cavity, balance the heat flow difference between the corners and the central area, and convert unidirectional concentrated high-temperature radiation heat into uniform heat dissipation energy in the whole area laterally. It completely solves the defects of over-burning and under-burning batches caused by the large span of the large furnace cavity and the uneven temperature field stratification. At the same time, it weakens the interlayer shear force of alternating hot and cold, and has the dual functions of heat uniformity and interlayer reinforcement.

[0043] The cross-section of the irregularly shaped refractory bricks used in the third layer structure 5-3 is also Z-shaped. The brick type and specifications should ideally be the same as those in the first layer structure 5-1, and both ends of each column should be flattened. This layer is arranged longitudinally on top of the second layer structure 5-2, following the gaps formed by the transverse arrangement of the bricks. The joints between the bricks are located on the irregularly shaped refractory bricks of the second layer structure 5-2, ensuring structural stability. Simultaneously, this layer covers the gaps formed by the transverse arrangement of the second layer structure 5-2, forming a flue gas flow channel with the gaps between the first and second layers structure 5-1. This ensures stable heat transfer while providing stable support for the sagger, guaranteeing stable and uniform heating of the sagger.

[0044] The fixed connection methods in the technical solution of this invention include detachable threaded connections, pin connections, chain connections, spline connections, etc.; it also includes non-detachable connections: welding, riveting, interference fit, etc.; the movable connection can be hinges, bearings, and slide rails, etc., which can be selected and adapted according to different working scenario requirements.

[0045] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A large-cavity, covered, ring-type roasting furnace, characterized in that: It includes a furnace chamber (1-1) surrounded by a furnace shell (1) and a furnace cover (9) covering the top. The furnace chamber (1-1) is provided with a furnace cavity (1-2). The front and back of the furnace cavity (1-2) are separated by a partition wall (2). The left and right sides of the furnace cavity (1-2) are separated from the furnace shell (1) by side walls (3). The partition wall (2) is provided with a cavity (10). The two ends of the partition wall (2) are connected to the side walls (3). The bottom of the furnace cavity (1-2) is evenly distributed with a group of supports (4). The upper part of the group of supports (4) is provided with a kang surface (5).

2. The large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: Expansion joints are left between the two ends of the partition wall (2) and the side wall (3).

3. The large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: Below the partition wall (2) is a partition wall support (8) composed of irregularly shaped refractory bricks, and the partition wall support (8) is arranged longitudinally at intervals.

4. A large-cavity covered ring-type roasting furnace according to claim 3, characterized in that: Two or more furnace chambers (1-2) are connected in series longitudinally. The furnace chambers (1-2) are separated by the partition wall (2) and the partition wall support (8). The front side of the first furnace chamber (1-2) in series is provided with a connecting fire channel (6). The connecting fire channel (6) is made of irregular refractory bricks in the shape of an arch, with one end built on the bottom of the furnace and the other end built on the partition wall support (8).

5. A large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: Anchors (7) are provided between the furnace shell (1) and the side wall (3).

6. A large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: The cavity (10) includes a first cavity (10-1) and a second cavity (10-2) forming a closed double-loop structure. The first cavity (10-1) is filled with heat-insulating and refractory material, and the second cavity (10-2) is a hollow fire well.

7. A large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: The support group (4) is composed of irregularly shaped refractory bricks, which are evenly distributed on the bottom surface of the furnace.

8. A large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: The kang surface (5) includes a first layer structure (5-1), a second layer structure (5-2), and a third layer structure (5-3) composed of irregularly shaped refractory bricks from bottom to top. The first layer structure (5-1) is set on the support group (4) and arranged longitudinally at intervals. The second layer structure (5-2) is arranged laterally at intervals and covers the gaps of the first layer structure (5-1). The third layer structure (5-3) is arranged longitudinally at intervals and covers the gaps of the second layer structure (5-2).

9. A large-cavity covered ring-type roasting furnace according to claim 1, characterized in that: The sidewall (3) is composed of irregularly shaped refractory bricks, heat-insulating bricks and refractory fibers interwoven, or is composed of refractory fibers.

10. A large-cavity covered ring-type roasting furnace according to claim 5, characterized in that: The anchor (7) consists of an expansion bolt and a hook. The expansion bolt is inserted into the furnace shell (1), and the tail of the hook is located on the side wall (3).

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