A flue gas introduction device of a temperature-raising preheating furnace
Patent Information
- Application Number
- CN202522004118.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-18
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2035-09-18
AI Technical Summary
该结构设计存在以下技术缺陷：其一，受限于单侧进气的流场分布特性，导致预热器内部形成非对称温度梯度，显著降低烟气热交换效率；其二，由于伯努利效应，在预热器入口段会产生局部压力集中现象，将引发金属疲劳损伤，严重影响设备运行稳定性及使用寿命
[0008]本实用新型的有益效果如下：通过改变换预热炉烟气入口与热风炉出气口之间的连接方式，摒弃传统膨胀节式单管轴向连接结构，在预热炉圆周方向集成设置环形分流腔体，该腔体与热风炉出气口形成径向耦合连接，此种连接方式能够均衡烟气压力，减小预热炉烟气入口压力，延长设备使用寿命；此种连接方式在分流腔体轴向对称布置双侧切向进气通道，使得烟气高效进入预热炉，能够提升烟气热交换效率。
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Figure CN224887661U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical acid preheating furnace technology, and more specifically to a flue gas introduction device for a preheating furnace. Background Technology
[0002] In the acid production process, the preheating furnace heats the cold gas or catalyst bed to the required reaction temperature during system startup, ensuring rapid catalyst activation. It also maintains the reaction temperature, improving conversion efficiency. By supplementing heat, the preheating furnace ensures the gas enters the converter at the optimal reaction temperature. Precise temperature control prevents stress cracking of materials inside the converter due to thermal shock and reduces low-temperature dew point corrosion (such as sulfuric acid condensation corrosion of pipes). The preheating furnace plays a crucial "temperature hub" role in the acid production process, ensuring efficient catalytic reactions and improving system energy efficiency through thermal management. It is a key support for process continuity, safety, and economy. Its design must consider thermodynamic optimization, material temperature resistance, and automated control to achieve efficient and stable operation of sulfuric acid production.
[0003] In existing technical solutions, an expansion joint-type single-pipe axial connection structure is used between the preheater flue gas inlet and the hot blast stove outlet. This structural design has the following technical defects: First, due to the limited flow field distribution characteristics of unilateral air intake, an asymmetric temperature gradient is formed inside the preheater, significantly reducing the flue gas heat exchange efficiency; Second, due to the Bernoulli effect, local pressure concentration will occur in the preheater inlet section, which will cause metal fatigue damage and seriously affect the operational stability and service life of the equipment. Utility Model Content
[0004] The purpose of this utility model is to provide a preheating furnace flue gas introduction device in order to solve the above-mentioned technical problems.
[0005] To achieve the above objectives, this utility model specifically adopts the following technical solution: a flue gas introduction device for a preheating furnace, comprising a hot air furnace, a heat exchanger, and a preheater. The top of the hot air furnace is provided with a flue gas outlet, which is coupled to the flue gas inlet of the heat exchanger. The heat exchanger is equipped with a preheater inside, and a heat exchange cavity is provided between the preheater and the heat exchanger. A flow divider block is fixedly connected to the outer wall of the preheater, and the flow divider block is located between the heat exchange cavity and the flue gas inlet.
[0006] To facilitate the diversion of flue gas entering the heat exchange cavity, in a preferred embodiment of the flue gas introduction device for a preheating furnace according to this utility model, the diameter of the diversion block is larger than the inner diameter of the flue gas inlet.
[0007] To facilitate the discharge of cooled flue gas, in a preferred embodiment of the flue gas introduction device for a preheating furnace according to this utility model, the heat exchange cavity is connected to a flue gas outlet, and the outlet end of the flue gas outlet extends through to the outside of the heat exchanger.
[0008] The beneficial effects of this utility model are as follows: By changing the connection method between the flue gas inlet of the preheating furnace and the gas outlet of the hot blast stove, the traditional expansion joint type single-pipe axial connection structure is abandoned. An annular diversion cavity is integrated in the circumferential direction of the preheating furnace. This cavity forms a radial coupling connection with the gas outlet of the hot blast stove. This connection method can balance the flue gas pressure, reduce the flue gas inlet pressure of the preheating furnace, and extend the service life of the equipment. In this connection method, the double-sided tangential air inlet channels are arranged symmetrically in the diversion cavity, so that the flue gas can enter the preheating furnace efficiently, which can improve the flue gas heat exchange efficiency. Attached Figure Description
[0009] Figure 1 This is a schematic diagram of the improved structure of this utility model; Figure 2 This is a schematic diagram of the structure before the improvement of this utility model.
[0010] Attached reference numerals: 1. Hot air furnace; 101. Flue gas outlet; 2. Expansion joint; 3. Heat exchanger; 301. Heat exchange chamber; 302. Flue gas outlet; 303. Diverting block; 304. Flue gas inlet; 305. Small flue gas inlet; 4. Preheater. Detailed Implementation
[0011] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.
[0012] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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.
[0013] Please see Figure 1The present invention provides the following improved technical solution: a preheating furnace flue gas introduction device, including a hot air furnace 1, a heat exchanger 3 and a preheater 4. The top of the hot air furnace 1 is provided with a flue gas outlet 101, which is coupled to the flue gas inlet 304 of the heat exchanger 3. The preheater 4 is installed inside the heat exchanger 3. A heat exchange cavity 301 is provided between the preheater 4 and the heat exchanger 3. A flow divider block 303 is fixedly connected to the outer wall of the preheater 4. The flow divider block 303 is located between the heat exchange cavity 301 and the flue gas inlet 304. The diameter of the flow divider block 303 is larger than the inner diameter of the flue gas inlet 304. The heat exchange cavity 301 is connected to a flue gas outlet 302, and the outlet end of the flue gas outlet 302 extends through to the outside of the heat exchanger 3.
[0014] In this embodiment: by changing the connection method between the flue gas inlet 304 of the heat exchanger 3 and the outlet of the hot blast furnace 1, the traditional expansion joint type single-pipe axial connection structure is abandoned. An annular diversion heat exchange cavity 301 is integrated in the circumferential direction of the preheater 4. This cavity forms a radial coupling connection with the outlet of the hot blast furnace 1. This connection method can balance the flue gas pressure, reduce the flue gas inlet pressure of the preheater furnace, and extend the service life of the equipment. By setting a diversion block 303 in the heat exchange cavity, and then symmetrically arranging double-sided tangential air inlet channels in the diversion cavity, the flue gas can enter the preheater furnace efficiently, which can improve the flue gas heat exchange efficiency.
[0015] Please see Figure 2 The technical solution before the improvement of this utility model: The device before the improvement includes a hot air furnace 1, a heat exchanger 3 and a preheater 4. The top of the hot air furnace 1 is provided with a flue gas outlet 101. The flue gas outlet 101 and the flue gas inlet 304 are installed through an expansion joint 2. Multiple small flue gas inlets 305 in the heat exchanger 3 are used for flue gas to enter the heat exchange cavity 301. The preheater 4 is installed inside the heat exchanger 3. The heat exchange cavity 301 is connected to a flue gas outlet 302. The outlet end of the flue gas outlet 302 extends through to the outside of the heat exchanger 3.
[0016] In the previous embodiment, the hot flue gas inlet 304 of the heat exchanger 3 and the flue gas outlet 101 of the hot blast furnace 1 were connected by an expansion joint type single pipe axial connection. This connection method is constrained by the single-sided air intake structure, and the flue gas cannot be fully heated in the preheater 3, which will cause a loss of effective heat exchange area and reduce heat exchange efficiency. Since the flue gas can only enter from one side, alternating thermal stress will be generated on the metal wall of the preheating furnace, which will cause metal fatigue damage. Due to the excessive pressure on one side, the possibility of cracks in the weld at this point will also be greatly increased, which will affect the stability of the system and reduce the service life of the equipment.
[0017] The technical solutions provided by the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of this utility model. The description of the above embodiments is only for helping to understand the principles of the embodiments 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 embodiments of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.
Claims
1. A flue gas introduction device for a preheating furnace, comprising a hot air furnace (1), a heat exchanger (3), and a preheater (4), characterized in that: The hot air furnace (1) is provided with a flue gas outlet (101) at the top. The flue gas outlet (101) is coupled to the flue gas inlet (304) of the heat exchanger (3). A preheater (4) is installed inside the heat exchanger (3). A heat exchange cavity (301) is provided between the preheater (4) and the heat exchanger (3). A flow divider block (303) is fixedly connected to the outer wall of the preheater (4). The flow divider block (303) is located between the heat exchange cavity (301) and the flue gas inlet (304).
2. The preheating furnace flue gas introduction device according to claim 1, characterized in that: The diameter of the flow divider block (303) is larger than the inner diameter of the flue gas inlet (304).
3. The preheating furnace flue gas introduction device according to claim 1, characterized in that: The heat exchange cavity (301) is connected to a flue gas outlet (302), and the outlet end of the flue gas outlet (302) extends through to the outside of the heat exchanger (3).