A twin kiln

Abstract

The present application relates to a double chamber kiln, including two kiln bodies, a feeding system, a waste gas discharge system, a fuel supply system, a discharging system and a control system. The kiln body is reconstructed from the kiln body of a beam lime kiln or a common shaft kiln. The kiln body includes a preheating zone, a calcining zone and a cooling zone, and the calcining zone is provided with at least one plug-in burner. A flue port is arranged between the calcining zone and the cooling zone of the kiln body, and the flue port is arranged on the corresponding outer wall of the two kiln bodies. The flue ports of the two kiln bodies are connected together through a flue channel. The flue channel is inserted into the interior of the two kiln bodies, and the upper part of the flue channel insertion part of the kiln body is provided with 2-10 support beams, and the upper part of the support beam is provided with a ridge structure, and the included angle of the ridge structure is 120-150°. The present application sets a flue channel in the beam lime kiln or the common shaft kiln, connects the two kiln bodies together through the flue channel, and adds support beams and ridge structures in the flue channel insertion part of the kiln body, thereby improving the safety of the connection part of the flue channel and the kiln body, and being beneficial to the long-period safe operation of the double chamber kiln reconstructed from the beam kiln.

Description

Technical Field

[0001] This invention belongs to the technical field of chemical building materials production equipment, and relates to a double-chamber kiln. Background Technology

[0002] A double-chamber kiln, also known as a double-chamber parallel-flow regenerative lime kiln, has fuel entering from the upper end of the calcination zone and flowing parallel to the raw material. Because the fuel is injected from the upper part of the calcination zone, the raw material absorbs most of the heat released by the fuel at this point, and the average temperature of the calcination zone is 950℃. Another important feature of the double-chamber kiln is its heat storage function, which preheats a portion of the combustion air. The thermal characteristics of parallel-flow calcination and counter-flow heat storage determine that the double-chamber kiln has very high thermal efficiency. Its heat consumption is the lowest among all types of lime kilns, including rotary kilns and sleeve kilns, with a total heat consumption of less than 3.8 GJ / ton of lime.

[0003] In existing beam-type lime kilns, the combustion beams, when using solid fuels to calcine lime, suffer from less than ideal calcification results due to technological limitations, and cannot fully meet the quality requirements for lime kiln flue gas emissions. Ordinary vertical kilns, due to their structural limitations, have limited adaptability to fuels, resulting in poorer product quality.

[0004] By connecting two beam-type lime kilns or ordinary vertical kilns through an external flue gas duct, a double-chamber kiln can be converted into a lime kiln. However, because the part of the flue gas duct inserted into the kiln body bears the impact of falling limestone, it often breaks or other malfunctions, affecting the safety of lime kiln production. Summary of the Invention

[0005] The purpose of this invention is to provide a double-chamber kiln that improves the safety of flue gas passage insertion into the kiln body in a double-chamber kiln converted from a beam kiln by optimizing the design structure of the connection between the kiln body and the flue gas passage. This is beneficial for expanding the production capacity of the equipment, reducing energy consumption, and improving product quality.

[0006] The technical solution of this invention is: a double-chamber kiln converted from a beam kiln, comprising two kiln bodies, a feeding system, a waste gas emission system, a fuel supply system, a discharge system, and a control system. The kiln bodies are converted from beam-type lime kilns or ordinary vertical kilns. Each kiln body has a feeding port at the top and a discharge port at the bottom. The kiln body includes a preheating zone, a calcining zone, and a cooling zone. The calcining zone is equipped with at least one insert burner. A flue gas / combustion vent is located at the top of the preheating zone, connected to the waste gas emission system of the combustion fan via a three-way valve. A cooling air inlet is located at the bottom of the cooling zone, connected to a cooling fan. A flue gas duct is located between the calcining zone and the cooling zone of the kiln body, situated on the corresponding outer walls of the two kiln bodies. The flue gas ducts of the two kiln bodies are connected together via a flue gas passage. The flue gas passage is inserted into the interior of two kiln bodies. The upper part of the part of the flue gas passage inserted into the kiln body is equipped with 2-10 support beams. The upper part of the support beams is equipped with a ridge structure with an included angle of 120-150°.

[0007] The support beams are arranged in the same direction as or perpendicular to the flue gas passage. The support beams are sleeve-type steel structures with channels for the flow of cooling medium, which can be heat transfer oil, water, or air. The ridge structure is made of carbon steel or stainless steel, and its surface is coated with a wear-resistant and high-temperature-resistant layer. The flue gas passage is installed between two kiln bodies via supports. The exhaust gas system includes a dust collector, an induced draft fan, and a chimney, which are connected sequentially. The insertion burners are gas fuel burners, liquid fuel burners, or solid fuel burners, or any combination of two of these. The outer shell of the flue gas passage is a steel structure, lined with an insulation layer and a wear-resistant layer; the internal annular channel is a steel structure, lined with an insulation layer and a wear-resistant layer.

[0008] This invention relates to a double-chamber kiln converted from a beam-type kiln. Through optimized design, a flue gas channel is incorporated into either a beam-type lime kiln or a conventional vertical kiln. This channel connects the two kiln bodies together. By adding supporting beams and a ridge structure to the portion of the flue gas channel inserted into the kiln body, the safety of the connection between the flue gas channel and the kiln body is improved. This facilitates the long-term safe operation of the double-chamber kiln converted from a beam-type kiln, expands the production capacity of the unit, reduces energy consumption, and improves product quality. It achieves the desired lime production effect from calcining limestone in a double-chamber kiln, and is particularly suitable for converting existing lime kilns. Converting existing kilns fully utilizes existing resources, saves on construction investment, and increases the economic benefits for enterprises. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the double-chamber kiln converted from a beam kiln according to the present invention;

[0010] Figure 2 for Figure 1 B-direction graph;

[0011] Figure 3 for Figure 1 AA diagram;

[0012] Figure 4 This is a schematic diagram of another embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of the mechanism of the third embodiment of the present invention;

[0014] Figure 6 This is a schematic diagram of the inner sleeve support structure;

[0015] Figure 7 A schematic diagram of an inner sleeve support structure with an inner ring structure;

[0016] Figure 8 This is a schematic diagram of a double-chamber kiln with a circular kiln body structure.

[0017] Wherein: 1—insertion burner, 2—kiln body, 3—ridge structure, 4—support beam, 5—flue gas passage inserted into the kiln body, 6—flue gas passage, 7—discharge port, 8—flue gas duct opening, 9—support, 10—inner sleeve support structure. Implementation

[0018] The present invention will now be described in detail with reference to the embodiments and accompanying drawings. The scope of protection of the present invention is not limited to the embodiments, and any modifications made by those skilled in the art within the scope defined by the claims also fall within the scope of protection of the present invention. Example 1

[0019] This invention relates to a double-chamber kiln converted from a beam-type kiln, such as... Figure 1 As shown, the system includes two kiln bodies, a feeding system, an exhaust gas emission system, a fuel supply system, a discharge system, and a control system. The exhaust gas emission system includes a dust collector, an induced draft fan, and a chimney, which are connected sequentially. Example 1 is applicable to the renovation of existing vertical kilns (including but not limited to beam kilns). The kiln body is renovated from the kiln body of a beam lime kiln. Each kiln body has a feeding port at the top and a discharge port 7 at the bottom. The kiln body includes a preheating zone, a calcination zone, and a cooling zone. The calcination zone has at least one insert burner 1, which is a gas fuel burner. The preheating zone has a flue gas / combustion air inlet at the top, which is connected to the combustion fan and the exhaust gas emission system via a three-way valve. The cooling zone has a cooling air inlet at the bottom, which is connected to a cooling fan. A flue gas duct 8 is provided between the calcination zone and the cooling zone of the kiln body, and the flue gas duct is located on the corresponding outer wall of the two kiln bodies. The flue gas inlets of the two kiln bodies are connected by flue gas channel 6, which is installed between the two kiln bodies via a bracket 9. The outer shell of the flue gas channel is a steel structure, lined with an insulation layer and a wear-resistant layer. Figure 2 and 3As shown, the flue gas passage is inserted into the interior of two kiln bodies. Four support beams 4 are located above the part of the flue gas passage inserted into the kiln body 5, and these support beams are arranged in the same direction as the flue gas passage. Alternatively, the support beams can be arranged perpendicular to the flue gas passage. The support beams are inner sleeve steel structures with channels for the flow of cooling medium, which is heat transfer oil. Water cooling or air cooling can also be used to cool the support beams. A ridge structure 3 is located above the support beams, with an included angle of 140°. The ridge structure is made of carbon steel and coated with a wear-resistant and high-temperature-resistant layer. The ridge structure 3, the support beams 4, and the part of the flue gas passage inserted into the kiln body 5 constitute the inner sleeve support structure 10.

[0020] The operation of the double-chamber kiln, converted from a beam kiln, is as follows: During calcination in kiln A, fuel is injected through the insert burner 1 in kiln A. Combustion air enters kiln A through a three-way valve from the flue gas / combustion air inlet for combustion, calcining the limestone material in kiln A. The flue gas generated during calcination passes through an external flue gas channel 6 to kiln B to preheat the material in the kiln, and then exits through the flue gas / combustion air inlet and the three-way valve in kiln B to the exhaust system. During calcination, the fuel is evenly distributed across the entire cross-section of the kiln, resulting in a uniform temperature field across each cross-section of the calcination zone, which is highly beneficial for the uniform calcination of limestone. After 12 minutes of operation, the flow is reversed. After the reversal, kiln B calcines while kiln A stores heat. The two kilns alternate between parallel-flow calcination and counter-flow heat storage, with automatic reversal achieved through valve operation. After calcination, the lime enters the cooling zone, where it exchanges heat with the cooling air entering from the cooling air inlet, lowering the lime temperature to 60-80℃. It then exits the kiln through outlet 7. The cooling air, after cooling the lime, increases in temperature and mixes with the combustion flue gas before entering the kiln chamber, which is currently storing heat, through flue gas passage 6. The mixed gas directly exchanges heat with the limestone, transferring heat energy to the limestone before its temperature drops to approximately 150℃ and is discharged through the exhaust system. Example 2

[0021] Another embodiment of the present invention is as follows: Figure 4As shown, it includes two kiln bodies, a feeding system, a waste gas emission system, a fuel supply system, a discharge system, and a control system. Example 2 is applicable to the renovation of existing vertical kilns (including but not limited to beam kilns). A flue gas inlet 8 is provided between the calcination zone and cooling zone of the kiln body, located on the corresponding outer walls of the two kiln bodies. The flue gas inlets of the two kiln bodies are connected together by a flue gas channel 6, which is installed between the two kiln bodies via a support frame. The outer shell of the flue gas channel is a steel structure, lined with an insulation layer and a wear-resistant layer. The internal annular channel is also a steel structure, lined with an insulation layer and a wear-resistant layer. The flue gas channel is inserted into the interior of the two kiln bodies. Four support beams 4 are provided at the upper part of the part of the flue gas channel inserted into the kiln body 5, arranged perpendicular to the flue gas channel. The support beams are sleeve-type steel structures with channels for the flow of cooling medium, which is water. A ridge structure 3 is provided at the upper part of the support beams, with an included angle of 150°. The ridge structure is made of stainless steel and coated with a wear-resistant and high-temperature resistant layer. The ridge structure 3, the support beam 4, and the flue gas passage inserted into the kiln body 5 constitute the inner sleeve support structure 10. Other structures are the same as in Example 1. In Example 2, the support beam is located on the side near the furnace wall, and the corresponding ridge structure is a single ridge for inward material flow.

[0022] During calcination in kiln A, fuel is injected through the insert burner in kiln A. Combustion air enters kiln A through a three-way valve from the flue gas / combustion air inlet for combustion, calcining the limestone material in kiln A. The flue gas generated during calcination passes through flue gas channel 6 to kiln B to preheat the material in the kiln, and then exits through the flue gas / combustion air inlet and three-way valve in kiln B to the exhaust system. During calcination, the fuel is evenly distributed across the entire cross-section of the kiln, resulting in a uniform temperature field across each cross-section of the calcination zone, which is highly beneficial for the uniform calcination of limestone. After 12 minutes of operation, the flow is reversed. After reversal, kiln B calcines while kiln A stores heat. The two kilns alternate between parallel-flow calcination and counter-flow heat storage, with automatic reversal achieved through valve operation. After calcination, the lime enters the cooling zone, where it exchanges heat with the cooling air entering from the cooling air inlet, reducing the lime temperature to 60–80°C, and then exits the kiln through discharge port 7. The cooling air temperature rises after the lime is cooled, and it mixes with the combustion flue gas as it rises. Then, it enters the kiln chamber where heat is being stored through the external connection channel 6. The mixed gas directly exchanges heat with the limestone, transferring heat energy to the limestone before its temperature drops to approximately 150°C and is discharged through the exhaust system. Only one pipe (with an internal insulation layer) is installed between the outer sides of the two kiln bodies as an external connection channel, ensuring that the flue gas generated during combustion in one cycle can evenly enter the other kiln chamber. Example 3

[0023] The third embodiment of the present invention is as follows Figure 5 , Figure 6As shown, the system includes two kiln bodies, a feeding system, an exhaust gas emission system, a fuel supply system, a discharge system, and a control system. The exhaust gas emission system includes a dust collector, an induced draft fan, and a chimney, which are connected sequentially. The two kiln bodies are built close together, with a feeding port at the top and a discharge port 7 at the bottom of each kiln body. A support beam 4 is provided between the calcination zone and cooling zone of the kiln bodies, and the two kiln bodies share one support beam 4. A flue gas duct is provided between the two kiln bodies (below the support beam). The support beam is a steel structure lined with an insulation layer and a wear-resistant layer. The support beam is an inner sleeve-type steel structure with channels for the flow of cooling medium, which is heat transfer oil. Alternatively, water cooling or air cooling can be used to cool the support beam. A ridge structure 3 is provided on the upper part of the support beam, with an included angle of 130°. The ridge structure is made of carbon steel and coated with a wear-resistant and high-temperature resistant layer. The ridge structure 3, the support beam 4, and the flue gas passage inserted into the kiln body 5 constitute the inner sleeve support structure 10.

[0024] like Figure 7 The image shows a double-chamber kiln with an internal annular channel structure. The internal annular channel is located inside the kiln body and is made of steel, lined with an insulation layer and a wear-resistant layer. The kiln structure above the calcination zone can also be supported by corbels or suspended cylinders. The kiln body cross-section can also be of any shape. Figure 8 It is a double-chamber kiln with a circular cross-section.

Claims

1. A double-chamber kiln, comprising two kiln bodies (2), a feeding system, a waste gas emission system, a fuel supply system, a discharge system, and a control system; wherein the kiln body is converted from a beam-type lime kiln or a conventional vertical kiln, and each kiln body is provided with a feeding port at the top and a discharge port (7) at the bottom; the kiln body includes a preheating zone, a calcination zone, and a cooling zone, wherein the calcination zone is provided with at least one insert burner (1); the preheating zone is provided with a flue gas / combustion air inlet at the top, which is connected to a combustion air fan and a waste gas emission system via a three-way valve; the cooling zone is provided with a cooling air inlet at the bottom, which is connected to a cooling air fan; characterized in that: A flue gas duct (8) is provided between the calcination zone and the cooling zone of the kiln body (2). The flue gas duct (8) is located on the outer wall of the two kiln bodies respectively. The flue gas ducts of the two kiln bodies are connected together by a flue gas channel (6). The flue gas channel is inserted into the interior of the two kiln bodies. The upper part of the part of the flue gas channel inserted into the kiln body (5) is provided with 2-10 support beams (4). The upper part of the support beams is provided with a ridge structure (3). The included angle of the ridge structure is 120-150°. The ridge structure (3), the support beams (4) and the part of the flue gas channel inserted into the kiln body (5) constitute the inner sleeve support structure (10).

2. The twin chamber kiln of claim 1 wherein, The support beam (4) is arranged in the same direction as the flue gas passage (6) or the support beam (4) is arranged perpendicular to the flue gas passage (6).

3. The dual chamber kiln of claim 1 wherein: The supporting beam (4) is a sleeve-type steel structure with a channel for the flow of cooling medium, which is heat transfer oil, water or air.

4. The dual chamber kiln of claim 1 wherein: The ridge structure is made of carbon steel or stainless steel, and the top of the ridge structure is coated with a wear-resistant and high-temperature resistant layer.

5. The double-chamber kiln according to claim 1, characterized in that: The flue gas passage (6) is installed between the two kiln bodies via a bracket (9).

6. The twin chamber kiln of claim 1 wherein: The exhaust gas emission system includes a dust collector, an induced draft fan, and a chimney, which are connected in sequence.

7. The twin chamber kiln of claim 1 wherein: The insertable burner (1) is a gas fuel burner, a liquid fuel burner, or a solid fuel burner, or a combination of any two of the above.

8. The twin chamber kiln of claim 1 wherein: The outer shell of the flue gas passage (6) is a steel structure, with an inner lining of a heat insulation layer and a wear-resistant layer.

Images