A molten casting mixing furnace flue gas waste heat recovery system
By connecting a dust collector to the air inlet of the tubular heat exchanger and using a baffle plate design to form a multi-stage vortex field, the problem of reduced heat exchange efficiency and shortened equipment life caused by dust accumulation is solved, achieving efficient dust removal and low-cost maintenance.
Patent Information
- Application Number
- CN202520967608.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-05-16
AI Technical Summary
When traditional tubular heat exchangers process high-temperature flue gas, dust tends to accumulate on the surface of the heat exchange tubes, leading to reduced heat exchange efficiency, increased pressure loss, shortened equipment lifespan, and high maintenance costs. Furthermore, the cost of replacing the structure is substantial.
A simple dust removal structure is connected to the air inlet of the tubular heat exchanger. A multi-stage vortex field is formed by using baffle design to achieve efficient dust separation. Dust is also cleaned regularly by a dust collection drawer to prevent dust accumulation inside the heat exchanger.
It significantly improves heat exchange efficiency, reduces pressure loss, extends equipment life, reduces maintenance frequency and cost, and does not require changes to the existing heat exchanger structure.
Smart Images
Figure CN224681279U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of flue gas treatment devices for melting and casting mixing furnaces, and specifically to a waste heat recovery system for flue gas from melting and casting mixing furnaces. Background Technology
[0002] Currently, in the waste heat recovery systems of flue gas from melting and casting workshops in domestic electrolytic aluminum plants or recycled aluminum plants, high-temperature flue gas carries a large amount of metal oxide dust (such as Al2O3, SiO2, etc.), with dust concentrations typically reaching 50-150 g / m³. When traditional tubular heat exchangers directly treat this type of flue gas, dust easily accumulates on the surface of the heat exchange tubes, leading to the following technical problems: 1. Decreased heat exchange efficiency: For every 1 mm increase in dust layer thickness, the heat transfer coefficient decreases by approximately 15%, and in severe cases, the heat efficiency loss can reach over 40%; 2. Significantly increased pressure loss: Dust accumulation causes uneven flue gas velocity, increasing system resistance by 20%-50% and fan energy consumption by 30%; 3. Shortened equipment lifespan: Dust corrosion combined with high-temperature oxidation results in a heat exchange tube corrosion rate of up to 0.2 mm / year, reducing the lifespan to less than 2 years; 4. High maintenance costs: Frequent shutdowns for manual dust removal are required, with annual maintenance costs accounting for 15%-20% of the equipment investment.
[0003] Traditional dust removal methods are either structurally complex or require modifications to the structure of the tubular heat exchanger. Since tubular heat exchangers are mature products with low direct purchase costs, they are also relatively large in size. Changing the structure of the tubular heat exchanger would inevitably lead to significant cost pressure. Users prefer to solve the technical problem of dust accumulation on the surface of the heat exchange tubes of the tubular heat exchanger in a simple and low-cost way without changing the existing mature structure of the tubular heat exchanger. Utility Model Content
[0004] The purpose of this utility model is to provide a pre-dust-removing tubular heat exchanger, which solves a series of technical problems caused by dust accumulation on the surface of the heat exchange tubes by connecting a simple dust removal structure to the air inlet of the tubular heat exchanger without changing the original structure of the tubular heat exchanger. The purpose of this utility model is also to provide a waste heat recovery system for the flue gas of the melting and casting mixing furnace using the above-mentioned pre-dust-removing tubular heat exchanger.
[0005] The technical solution of this utility model's pre-dust removal tubular heat exchanger is as follows: The pre-dust removal tubular heat exchanger includes: The housing has an air inlet and an air outlet at each end, and a first connecting flange is provided at the air inlet. There are two tubing boxes, located on opposite sides of the shell, including a liquid inlet and a liquid outlet; There are multiple heat exchange tubes arranged side by side inside the shell, with the openings at both ends located in two tube boxes respectively; The dust collector includes a housing, baffles, and a dust collection mechanism. The housing has a dust collection inlet and a dust collection outlet. A second connecting flange is provided at the dust collection outlet. The dust collector is connected to the first connecting flange through the second connecting flange. The upper part of the housing has a cuboid structure, and the lower part of the housing has a trapezoidal structure that is wider at the top and narrower at the bottom to collect dust. The baffles include multiple upper baffles and multiple lower baffles. The upper baffles are arranged parallel to each other at intervals on the upper part of the housing, and the lower baffles are arranged parallel to each other at intervals on the lower part of the housing. The upper and lower baffles are arranged alternately to divide the space inside the housing into tortuous airflow channels. Both the upper and lower baffles are inclined towards the dust collection inlet. The dust collection mechanism is located at the bottom of the housing and includes a dust collection drawer that can be pulled out horizontally.
[0006] Based on the above scheme, the following improvement is made: the length of the lower baffle is greater than the length of the upper baffle.
[0007] Based on the above scheme, the following improvements are made: the bottom of the box is a flat plate structure.
[0008] Based on the above solution, the following improvements are made: the bottom of the box has a dust collection port, and a tray is provided under the dust collection port. Three sides of the tray are connected to the bottom of the box, and the other side has an opening for the dust collection drawer to enter and exit.
[0009] Based on the above solution, the following improvements are made: a telescopic bracket is provided on the lower outer side of the box, and the bottom of the telescopic bracket is welded and fixed to the upper part of the shell.
[0010] The technical solution of the waste heat recovery system for the flue gas of the casting and mixing furnace of this utility model is as follows: The waste heat recovery system for the flue gas of the casting and mixing furnace includes a flue gas inlet pipe and a flue gas outlet pipe, and also includes a pre-dust removal tube heat exchanger, which includes: The housing has an air inlet and an air outlet at each end. The air inlet is provided with a first connecting flange, and the air outlet is connected to the flue gas pipeline. There are two tubing boxes, located on opposite sides of the shell, including a liquid inlet and a liquid outlet; There are multiple heat exchange tubes arranged side by side inside the shell, with the openings at both ends located in two tube boxes respectively; The dust collector includes a housing, baffles, and a dust collection mechanism. The housing has a dust collection inlet and a dust collection outlet. The dust collection inlet is connected to the flue gas duct before the dust collection outlet, and a second connecting flange is provided at the dust collection outlet. The dust collector is connected to the first connecting flange through the second connecting flange. The upper part of the housing has a cuboid structure, and the lower part of the housing has a trapezoidal structure that is wider at the top and narrower at the bottom to collect dust. The baffles include multiple upper baffles and multiple lower baffles. The upper baffles are arranged parallel to each other at intervals on the upper part of the housing, and the lower baffles are arranged parallel to each other at intervals on the lower part of the housing. The upper and lower baffles are arranged alternately to divide the space inside the housing into tortuous airflow channels. Both the upper and lower baffles are inclined towards the dust collection inlet. The dust collection mechanism is located at the bottom of the housing and includes a dust collection drawer that can be pulled out horizontally.
[0011] Based on the above scheme, the following improvement is made: the length of the lower baffle is greater than the length of the upper baffle.
[0012] Based on the above scheme, the following improvements are made: the bottom of the box is a flat plate structure.
[0013] Based on the above solution, the following improvements are made: the bottom of the box has a dust collection port, and a tray is provided under the dust collection port. Three sides of the tray are connected to the bottom of the box, and the other side has an opening for the dust collection drawer to enter and exit.
[0014] Based on the above solution, the following improvements are made: a telescopic bracket is provided on the lower outer side of the box, and the bottom of the telescopic bracket is welded and fixed to the upper part of the shell.
[0015] The beneficial effects of this utility model are as follows: In the operation of the waste heat recovery system for smelting and casting mixing furnaces, a dust collector is connected to the air inlet of the tubular heat exchanger shell. This allows the high-temperature flue gas, which would normally enter the tubular heat exchanger directly, to first enter the dust collector for dust removal. The working principle is as follows: After the high-temperature flue gas carrying dust enters the dust collector inlet of the box, it flows sequentially through a tortuous airflow channel formed by upper and lower baffles arranged in a staggered pattern, dividing the space within the box. Since both the upper and lower baffles are inclined towards the dust collector inlet, the airflow needs to be deflected more than 180° each time it is blocked by the baffles. The lower baffle has a particularly good obstruction effect. Multiple inclined baffles create a multi-stage vortex field in the airflow, significantly improving the inertial separation effect and forming a highly efficient dust-blocking and separation structure. Furthermore, the trapezoidal structure facilitates the convergence of dust within the box, allowing it to be collected in the dust collection drawer. The dust collection drawer allows for convenient and quick periodic dust cleaning, reducing downtime for maintenance. As can be seen from the above, the design of the dust collector aims to achieve a simple structure, easy maintenance and operation, quick cleaning, and low cost. It can remove dust in advance before the flue gas enters the tubular heat exchanger, avoiding a series of problems such as rapid accumulation of dust in the tubular heat exchanger, which would lead to decreased heat exchange efficiency, increased pressure loss, shortened equipment life, and high maintenance costs.
[0016] Furthermore, by making the length of the lower baffle plate greater than that of the upper baffle plate, the dust-blocking length of the inclined lower baffle plate for the flue gas is increased on the one hand, and the dust is more easily dropped when the flue gas rises, thereby further improving the dust removal effect. Attached Figure Description
[0017] Figure 1 This is a system schematic diagram of a specific embodiment of the waste heat recovery system for a melting and casting mixing furnace according to this utility model; Figure 2 for Figure 1 A schematic diagram of the internal structure and working principle of a pre-dust removal tubular heat exchanger; Figure 3 for Figure 2 A schematic diagram of the internal structure of the dust collector box in the diagram; Figure 4 for Figure 3 Sectional view at point AA; Figure 5 for Figure 4 A magnified view of a section at point B in the middle; In the diagram: 1-Dust collection hood, 2-Flue gas inlet duct, 3-Pre-dust removal tubular heat exchanger, 31-Shell, 311-Inlet, 312-Outlet, 313-First connecting flange, 32-Pipe box, 321-Liquid inlet, 322-Liquid outlet, 33-Heat exchange tube, 34-Baffle plate, 35-Dust collector box, 351-Box body, 3511-Dust collector inlet, 3512-Dust collector outlet, 3513-Second connecting flange. 3514-Connecting bolt, 3515-Trapezoidal structure, 352-Upper baffle, 353-Lower baffle, 354-Dust collection drawer, 355-Tray, 356-Telescopic bracket, 357-Airflow channel, 4-Flue gas after-pipe, 5-Fan, 6-Chimney, 7-First circulating water pump, 8-Plate heat exchanger, 9-Second circulating water pump, 10-Water tank, 11-Third circulating water pump, 12-Make-up water pipe, 13-Level gauge. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model; that is, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The components of the embodiments of the present utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0020] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0021] The features and performance of this utility model will be further described in detail below with reference to the embodiments.
[0022] A specific embodiment of the waste heat recovery system for flue gas from a melting and casting mixing furnace according to this utility model is as follows: Figure 1 As shown, the waste heat recovery system for smelting and casting mixing furnace is used to recover waste heat from the smelting and casting workshop of an electrolytic aluminum plant or a recycled aluminum plant. It mainly includes a dust collection hood 1, a flue gas inlet pipe 2, a pre-dust removal tubular heat exchanger 3, a flue gas outlet pipe 4, a fan 5, a chimney 6, a first circulating water pump 7, a plate heat exchanger 8, a second circulating water pump 9, a water tank 10, a third circulating water pump 11, a water supply pipe 12, a level gauge 13, etc.
[0023] like Figure 2 As shown, the pre-dust-removing tubular heat exchanger includes a shell 31, tube boxes 32, heat exchange tubes 33, baffle plates, and a dust removal box 35. The shell 31 is cylindrical, with an inlet 311 and an outlet 312 at each end. A first connecting flange 313 is located at the inlet 311, and a corresponding connecting flange is located at the outlet 312. There are two tube boxes 32, located on opposite sides of the shell 31, including a liquid inlet 321 and a liquid outlet 322. Connecting flanges are also provided at the liquid inlet 321 and liquid outlet 322 for easy connection to water pipes. Multiple heat exchange tubes 33 are arranged side-by-side within the shell 31, with openings at both ends located within the two tube boxes 32.
[0024] like Figure 2-3As shown, the dust collector 35 includes a housing 351, baffles, and a dust collection mechanism. The housing 351 has a dust collection inlet 3511 and a dust collection outlet 3512. A second connecting flange 3513 is provided at the dust collection outlet 3512. The dust collector 35 is connected to the first connecting flange 313 through the second connecting flange 3513. The upper part of the housing 351 has a cuboid structure, and the lower part of the housing 351 has a trapezoidal structure 3515 that is wider at the top and narrower at the bottom to collect dust. The baffles include multiple pieces. An upper baffle 352 and multiple lower baffles 353 are arranged in parallel at intervals on the upper part of the housing 351, and the lower baffles 353 are arranged in parallel at intervals on the lower part of the housing 351. The upper and lower baffles are arranged alternately to divide the space inside the housing 351 into tortuous airflow channels 357. Both the upper and lower baffles are inclined towards the dust inlet 3511. The dust collection mechanism is located at the bottom of the housing 351 and includes a horizontally retractable dust collection drawer 354. In this embodiment, the bottom of the housing 351 is a flat plate structure. The bottom of the housing 351 has a dust collection port, and a tray 355 is provided below the dust collection port. Three sides of the tray 355 are connected to the bottom of the housing 351, and the other side has an opening for the dust collection drawer 354 to enter and exit. A telescopic bracket 356 is provided on the lower outer side of the housing 351, and the bottom of the telescopic bracket 356 is welded and fixed to the upper part of the housing 31. The length of the lower baffle 353 is greater than the length of the upper baffle 352. By making the length of the lower baffle 353 greater than the length of the upper baffle 352, on the one hand, the length of the inclined lower baffle 353 blocking the dust of the flue gas is increased, and on the other hand, the dust is more likely to fall when the flue gas rises, thereby further improving the dust removal effect.
[0025] In the operation of this utility model's waste heat recovery system for smelting and casting mixing furnace flue gas, a dust collector 35 is connected to the air inlet 311 of the shell 31 of the tubular heat exchanger. This allows the high-temperature flue gas, which would normally enter the tubular heat exchanger directly, to first enter the dust collector 35 for dust removal. The working principle is as follows: After the high-temperature flue gas carrying dust enters from the dust collector inlet 3511 of the housing 351, it flows through the tortuous airflow channels 357 formed by the staggered arrangement of upper and lower baffles that divide the space inside the housing 351. Since both the upper and lower baffles are inclined towards the dust collector inlet 3511, the airflow needs to be deflected by more than 180° each time it is blocked by the baffles. The lower baffle 353 has a particularly good obstruction effect. The multiple inclined baffles create a multi-stage vortex field in the airflow, significantly improving the inertial separation effect and forming a highly efficient dust-blocking and separation structure. Furthermore, the trapezoidal structure 3515 facilitates the convergence of dust within the housing 351, allowing it to be collected in the dust collection drawer 354. The dust collection drawer 354 enables convenient and quick periodic dust removal, reducing downtime for maintenance. As can be seen, the dust collector 35 is designed to achieve a simple structure, easy maintenance and operation, rapid cleaning, and low cost. It allows for dust removal before the flue gas enters the tubular heat exchanger, preventing rapid dust accumulation within the heat exchanger and avoiding a series of problems such as decreased heat exchange efficiency, increased pressure loss, shortened equipment lifespan, and high maintenance costs.
[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.
Claims
1. A waste heat recovery system for flue gas from a melting and casting mixing furnace, including pre-flue gas piping and post-flue gas piping, and a pre-dust-removing tubular heat exchanger, which includes: The housing has an air inlet and an air outlet at each end. The air inlet is provided with a first connecting flange, and the air outlet is connected to the flue gas pipeline. There are two tubing boxes, located on opposite sides of the shell, including a liquid inlet and a liquid outlet; There are multiple heat exchange tubes arranged side by side inside the shell, with the openings at both ends located in two tube boxes respectively; Its characteristic is that it further includes: The dust collector includes a housing, baffles, and a dust collection mechanism. The housing has a dust collection inlet and a dust collection outlet. The dust collection inlet is connected to the flue gas duct before the dust collection outlet. A second connecting flange is provided at the dust collection outlet. The dust collector is connected to a first connecting flange through the second connecting flange. The upper part of the housing has a cuboid structure, and the lower part of the housing has a trapezoidal structure that is wider at the top and narrower at the bottom to collect dust. The baffles include multiple upper baffles and multiple lower baffles. The upper baffles are arranged parallel to each other at intervals on the upper part of the housing, and the lower baffles are arranged parallel to each other at intervals on the lower part of the housing. The upper and lower baffles are arranged alternately to divide the space inside the housing into tortuous airflow channels. Both the upper and lower baffles are inclined towards the dust collection inlet. The dust collection mechanism is located at the bottom of the housing and includes a dust collection drawer that can be pulled out horizontally.
2. The waste heat recovery system for flue gas from a melting and casting mixing furnace according to claim 1, characterized in that, The length of the lower baffle is greater than the length of the upper baffle.
3. The waste heat recovery system for flue gas from a melting and casting mixing furnace according to claim 1, characterized in that, The bottom of the box is a flat plate structure.
4. The waste heat recovery system for flue gas from a melting and casting mixing furnace according to claim 3, characterized in that, The bottom of the box has a dust inlet, and a tray is placed under the dust inlet. Three sides of the tray are connected to the bottom of the box, and the other side has an opening for the dust collection drawer to enter and exit.
5. The waste heat recovery system for flue gas from a melting and casting mixing furnace according to claim 1, characterized in that, The lower outer side of the box is provided with a telescopic bracket, and the bottom of the telescopic bracket is welded and fixed to the upper part of the shell.