Device for drying aluminum scrap by recovering and reusing waste heat

Abstract

The utility model relates to aluminum scrap drying technical field discloses the device of waste heat recovery and recycling drying aluminum scrap, including aluminum scrap stove, direct exhaust flue, drying kiln, tubular heat exchanger, air circulation pipe and fan, direct exhaust flue and tubular heat exchanger pipe inside flue gas passage intercommunication, tubular heat exchanger pipe outside air passage export is connected drying kiln through pipeline, drying kiln air outlet is connected back tubular heat exchanger pipe outside inlet through air circulation pipe, flue gas is in pipe, air is in pipe outside and carries out indirect heat exchange through pipe wall, direct exhaust flue installs first temperature measuring thermocouple, drying kiln intake pipe installs second temperature measuring thermocouple, and fan drives air circulation on air circulation pipe, in the utility model, realize flue gas and air indirect heat exchange through tubular heat exchanger, recover aluminum scrap stove flue gas waste heat, and the energy consumption is reduced significantly, avoid flue gas pollution aluminum scrap purity, air circulation reduces heat loss utilization rate, and cooperates temperature measurement and guarantees drying stability.

Description

TECHNICAL FIELD

[0001] The utility model relates to aluminum scrap drying technical field especially, it relates to a device for drying aluminum scrap by waste heat recovery and recycling. BACKGROUND

[0002] In the field of aluminum scrap processing, the aluminum scrap needs to be dried before recycling to remove moisture and oil stains, ensuring the smooth progress of subsequent processing. Traditional drying methods rely on burner combustion of fuel to heat air or direct heating of aluminum scrap. Such methods not only consume a large amount of natural gas and other energy sources, resulting in high operating costs, but also have the problem of insufficient energy utilization, which is inconsistent with the current industry development trend of energy saving and green production.

[0003] In the prior art, such as a device for drying aluminum scrap using flue gas waste heat (CN213273545U), the flue gas generated by the aluminum scrap furnace is directly introduced into the drying kiln to contact the aluminum scrap for drying. This direct contact method can cause dust and impurities in the flue gas to contaminate the aluminum scrap, affecting the purity of the aluminum scrap. At the same time, the flue gas is directly discharged after entering the drying kiln, which cannot realize the recycling of heat, resulting in low waste heat utilization rate and the need for more energy consumption. SUMMARY

[0004] To overcome the above shortcomings, the present utility model provides a device for drying aluminum scrap by waste heat recovery and recycling, aiming to improve the problem that the flue gas generated by the aluminum scrap furnace directly introduced into the drying kiln to contact the aluminum scrap for drying can cause dust and impurities in the flue gas to contaminate the aluminum scrap, affecting the purity of the aluminum scrap.

[0005] To achieve the above purpose, the present utility model adopts the following technical solution: a device for drying aluminum scrap by waste heat recovery and recycling, comprising an aluminum scrap furnace, a direct exhaust pipe, a drying kiln, a tubular heat exchanger, an air circulation pipe, and a fan. The direct exhaust pipe is in communication with the inner flue gas passage of the tubular heat exchanger, the outer air passage outlet of the tubular heat exchanger is connected to the drying kiln through a pipeline, and the air outlet of the drying kiln is connected back to the outer air passage inlet of the tubular heat exchanger through the air circulation pipe. The flue gas flows in the tube, and the air flows outside the tube in the tubular heat exchanger, separated by the tube wall and indirectly exchanges heat. The first temperature measuring thermocouple is installed on the direct exhaust pipe, the second temperature measuring thermocouple is installed on the air inlet pipe of the drying kiln, and the fan is installed on the air circulation pipe to drive the air to circulate between the air circulation pipe, the tubular heat exchanger, and the drying kiln.

[0006] Preferably, the tubular heat exchanger is a multi-group straight pipe structure, with flue gas flowing in the tube and air flowing outside the tube.

[0007] Preferably, the fan is a variable frequency fan, which can adjust the air volume according to the reading of the second temperature measuring thermocouple; the air circulation pipe is provided with a water vapor separation filter in series; and the water vapor separation filter separates the fine water droplets and water vapor in the air in the air circulation pipe through the built-in gas-liquid separation structure.

[0008] Preferably, the straight smoke pipe is provided with a flue check valve near the tubular heat exchanger, to prevent air from flowing back into the straight smoke pipe.

[0009] Preferably, the tubular heat exchanger is provided with a smoke exhaust pipe connected to the smoke outlet of the tubular heat exchanger, and the smoke exhaust pipe is provided with a manual valve.

[0010] Preferably, the tubular heat exchanger is made of ordinary boiler steel plate with a thickness of 3-4 mm, which has good heat conductivity and can guarantee the structural strength, so that the heat exchange efficiency and the equipment life are taken into account, and these effects are realized due to the material properties and thickness design.

[0011] Preferably, the air circulation pipe is wrapped with a rock wool insulation layer with a thickness of 30 mm, which can reduce the heat loss of the circulating air and enhance the energy saving effect, and this effect is realized due to the insulation properties and thickness design of the rock wool.

[0012] Preferably, the measuring range of the first temperature measuring thermocouple and the second temperature measuring thermocouple is 0-400 DEG C, which can cover the actual temperature of the flue gas and the hot air, and can accurately monitor the temperature, and this effect is realized due to the range adaptation to the actual demand.

[0013] Preferably, the tubular heat exchanger is provided with a metal mesh at the flue gas inlet, and the mesh size is 5-10 mm.

[0014] Preferably, the flue gas outlet of the aluminum scrap furnace and the straight smoke pipe are connected through flanges, and high-temperature-resistant asbestos gaskets are arranged between the flange contact surfaces to prevent flue gas leakage.

[0015] The utility model has the following beneficial effects:

[0016] 1. In the utility model, firstly, the device realizes indirect heat exchange between flue gas and air through the tubular heat exchanger, so that the waste heat of the flue gas generated by the aluminum scrap furnace is fully recovered and utilized, and the traditional drying burner is replaced, which significantly reduces energy consumption; at the same time, the design that the flue gas flows in the pipe and the air flows outside the pipe avoids direct contact between the flue gas and the aluminum scrap, prevents the aluminum scrap from being polluted by impurities in the flue gas, guarantees the purity of the aluminum scrap after drying, the circulating flow of the air between the air circulation pipe, the tubular heat exchanger and the drying kiln reduces heat loss and improves the waste heat utilization rate, and the monitoring of the first temperature measuring thermocouple and the second temperature measuring thermocouple can better guarantee the stability of the drying process.

[0017] 2、 The utility model discloses, tubular heat exchanger adopts multiple straight pipe structure, and the heat exchange area of flue gas and air is increased, and heat exchange efficiency is further improved, frequency conversion fan can adjust the air volume according to the reading of second temperature measuring thermocouple, realizes the accurate control of drying temperature, ensures drying effect, and air circulation pipe is in series with water vapor separation filter, and water vapor separation filter separates the tiny water droplet and water vapor of air circulation pipe in through its built-in gas-liquid separation structure, significantly reduces the moisture content in circulating air, and improves the drying effect of the device, flue check valve can effectively prevent air backflow into straight exhaust pipe, and guarantees the directional flow of flue gas, and the manual valve on exhaust pipe is convenient for controlling flue gas emission, improves the operational flexibility, and the pipe wall of tubular heat exchanger adopts ordinary boiler steel plate and the thickness is 3-4mm, and the heat conductivity and structural strength are considered, and the service life of equipment is prolonged, and the rock wool heat preservation layer outside air circulation pipe reduces heat loss in the circulation process, and enhances the energy-saving effect. The measurement range of first temperature measuring thermocouple and second temperature measuring thermocouple is 0-400 DEG C, can accurately adapt to the temperature monitoring demand of flue gas and hot air, and the metal net at the flue gas inlet of tubular heat exchanger can intercept large particle impurities and sparks, improves equipment operation safety, and the aluminum scrap furnace exhaust port is connected with straight exhaust pipe through flange and sets up high-temperature-resistant asbestos sealing pad, effectively prevents flue gas leakage, avoids heat waste, and reduces the influence on the environment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 It is the overall view of the device for recycling waste heat to dry aluminum scrap that the utility model provides;

[0019] Fig. 2 It is the tubular heat exchanger structure schematic view of the device for recycling waste heat to dry aluminum scrap that the utility model provides;

[0020] Fig. 3 It is the air circulation pipe, drying kiln and tubular heat exchanger cooperation schematic view of the device for recycling waste heat to dry aluminum scrap that the utility model provides.

[0021] Legend:

[0022] 1, aluminum scrap furnace;2, straight exhaust pipe;3, first temperature measuring thermocouple;4, fan;5, flue check valve;6, drying kiln;7, air circulation pipe;8, second temperature measuring thermocouple;9, exhaust pipe;10, manual valve;11, tubular heat exchanger;12, water vapor separation filter. DETAILED DESCRIPTION

[0023] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0024] Embodiment one, refer to Figs. 1-3 The device for recycling waste heat to dry aluminum scraps comprises an aluminum scrap furnace 1, a direct exhaust smoke pipe 2, a drying kiln 6, a tubular heat exchanger 11, an air circulation pipe 7 and a fan 4. The direct exhaust smoke pipe 2 is in communication with the pipe-in smoke passage of the tubular heat exchanger 11, the pipe-out air passage outlet of the tubular heat exchanger 11 is connected to the drying kiln 6 through a pipe, the air outlet of the drying kiln 6 is connected back to the pipe-out air passage inlet of the tubular heat exchanger 11 through the air circulation pipe 7. The smoke flows in the pipe and the air flows outside the pipe in the tubular heat exchanger 11, and they are separated by the pipe wall and exchange heat indirectly. The first temperature measuring thermocouple 3 is installed on the direct exhaust smoke pipe 2, the second temperature measuring thermocouple 8 is installed on the air inlet pipe of the drying kiln 6, and the fan 4 is installed on the air circulation pipe 7 to drive the air to circulate between the air circulation pipe 7, the tubular heat exchanger 11 and the drying kiln 6. The smoke from the aluminum scrap furnace 1 enters the tubular heat exchanger 11 through the direct exhaust smoke pipe 2, and the air circulates along the air circulation pipe 7, the pipe-out air passage of the tubular heat exchanger 11 and the drying kiln 6 under the driving of the fan 4, and exchanges heat indirectly through the pipe wall. The first temperature measuring thermocouple 3 and the second temperature measuring thermocouple 8 monitor the temperature. In this way, the waste heat of the smoke can be recycled to reduce energy consumption, the aluminum scraps can be prevented from being polluted by the smoke, and the heat loss can be reduced by the circulation. These effects are realized by the indirect heat exchange and the circulation design.

[0025] Embodiment two, refer to Figs. 1-3Based on Embodiment 1, the tubular heat exchanger 11 has a multi-straight-tube structure, with flue gas flowing inside the tubes and air flowing outside. This multi-row design increases the contact area between the flue gas and air, thereby improving heat exchange efficiency and achieving better heat transfer due to the increased contact area. The fan 4 is a variable-frequency fan, capable of adjusting the airflow based on the reading of the second thermocouple 8. By adapting to the hot air temperature requirements through airflow changes, the temperature of the drying kiln 6 can be precisely controlled. The flexibility of variable-frequency adjustment enables precise temperature control. A water vapor separator 12 is connected in series on the air circulation pipe 7. The water vapor separator 12 separates fine water droplets and water vapor from the air in the air circulation pipe 7 through its built-in gas-liquid separation structure. A flue gas check valve 5 is installed on the straight exhaust pipe 2 near the tubular heat exchanger 11 to prevent backflow of air into the straight exhaust pipe 2, ensuring that the flue gas flows directionally towards the tubular heat exchanger 11. The one-way conduction characteristic of the check valve enables... This effect is achieved through the following: the flue gas outlet of the tubular heat exchanger 11 is connected to a flue pipe 9, which is equipped with a manual valve 10. The manual valve 10 can control the opening and closing of the flue pipe 9, allowing for convenient and flexible adjustment of flue gas emissions. The opening and closing function of the valve achieves this effect. The tube wall of the tubular heat exchanger 11 is made of ordinary boiler steel plate with a thickness of 3mm. The air circulation pipe 7 is wrapped with a rock wool insulation layer with a thickness of 30mm. The first temperature measuring thermocouple 3 and the second temperature measuring thermocouple 8 have a measurement range of 0-400℃. A metal mesh with a mesh size of 5-10mm is installed at the flue gas inlet of the tubular heat exchanger 11. The flue gas outlet of the aluminum scrap furnace 1 is connected to the straight flue pipe 2 through a flange. A high-temperature resistant asbestos gasket is installed between the flange contact surfaces. The high-temperature resistant asbestos gasket is used to prevent flue gas leakage, avoid heat waste and environmental impact, and achieves this effect due to the high temperature resistance and sealing characteristics of the gasket.

[0026] Working principle: The high-temperature flue gas generated by the aluminum scrap furnace 1 enters the direct exhaust pipe 2 through its exhaust port. The direct exhaust pipe 2 transports the flue gas to the flue gas channel inside the tubular heat exchanger 11. Before entering the tubular heat exchanger 11, the flue gas passes through the metal mesh at its flue gas inlet. The mesh size is 5-10mm, which can intercept large particles and sparks in the flue gas. Inside the tubular heat exchanger 11, the flue gas flows along the inside of the pipe. At the same time, the flue gas check valve 5 on the direct exhaust pipe 2 near the tubular heat exchanger 11 prevents air from flowing back into the direct exhaust pipe 2, ensuring the directional flow of the flue gas. After heat exchange, the flue gas enters the exhaust pipe 9 through the flue gas outlet of the tubular heat exchanger 11. The manual valve 10 on the exhaust pipe 9 can control the emission of the flue gas. Finally, the flue gas is discharged through the exhaust pipe 9.

[0027] Fan 4 drives air to circulate between air circulation pipe 7, the external air passage of tubular heat exchanger 11, and drying kiln 6. As the air flows through the external air passage of tubular heat exchanger 11, it indirectly exchanges heat with the flue gas inside the pipes through the pipe walls. The pipe walls are made of ordinary boiler steel plates with a thickness of 3-4 mm, effectively transferring heat. The heated air then enters drying kiln 6 through pipes to dry the aluminum shavings. A second thermocouple 8 is installed on the inlet pipe of drying kiln 6. Both the second and first thermocouples (installed on the direct exhaust pipe 2) have a measurement range of 0-400℃, allowing for monitoring of the temperature of the hot air entering drying kiln 6. The temperature of the flue gas in the direct exhaust pipe 2 is measured. The fan 4 is a variable frequency fan, which can adjust the air volume according to the reading of the second temperature measuring thermocouple 8 to ensure stable drying effect. After drying, the air enters the air circulation pipe 7 through the air outlet of the drying kiln 6. The air circulation pipe 7 is wrapped with a 30mm thick rock wool insulation layer to reduce heat loss. Finally, the air flows back to the external air channel of the tubular heat exchanger 11 to re-participate in heat exchange, forming a closed loop. A water vapor separation filter 12 is connected in series on the air circulation pipe 7. The water vapor separation filter 12 separates the fine water droplets and water vapor in the air in the air circulation pipe 7 through the built-in gas-liquid separation structure.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for waste heat recovery and reuse in drying aluminum scrap, comprising an aluminum scrap furnace (1), a direct exhaust pipe (2), and a drying kiln (6), characterized in that: It also includes a tubular heat exchanger (11), an air circulation pipe (7), and a fan (4); the direct exhaust pipe (2) is connected to the flue gas channel inside the tubular heat exchanger (11), the outlet of the external air channel of the tubular heat exchanger (11) is connected to the drying kiln (6) through a pipe, and the air outlet of the drying kiln (6) is connected back to the inlet of the external air channel of the tubular heat exchanger (11) through the air circulation pipe (7); the flue gas inside the tubular heat exchanger (11) flows inside the pipe and the air flows outside the pipe, separated by the pipe wall and indirectly exchanging heat; the direct exhaust pipe (2) is equipped with a first temperature measuring thermocouple (3), the air inlet pipe of the drying kiln (6) is equipped with a second temperature measuring thermocouple (8), and the fan (4) is installed on the air circulation pipe (7) to drive the air to circulate between the air circulation pipe (7), the tubular heat exchanger (11), and the drying kiln (6).

2. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The tubular heat exchanger (11) has a multi-straight-tube structure, with flue gas flowing inside the tubes and air flowing outside.

3. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The fan (4) is a variable frequency fan, which can adjust the air volume according to the reading of the second temperature measuring thermocouple (8). A water vapor separation filter (12) is connected in series on the air circulation pipe (7). The water vapor separation filter (12) separates the fine water droplets and water vapor in the air circulation pipe (7) through the built-in gas-liquid separation structure.

4. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: A flue check valve (5) is installed on the direct exhaust pipe (2) near the tubular heat exchanger (11) to prevent air from flowing back into the direct exhaust pipe (2).

5. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The flue gas outlet of the tubular heat exchanger (11) is connected to a flue pipe (9), and a manual valve (10) is installed on the flue pipe (9).

6. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The tube wall of the tubular heat exchanger (11) is made of ordinary boiler steel plate with a thickness of 3-4 mm.

7. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The air circulation pipe (7) is wrapped with a rock wool insulation layer with a thickness of 30mm.

8. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The measurement range of the first temperature measuring thermocouple (3) and the second temperature measuring thermocouple (8) is 0-400℃.

9. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The flue gas inlet of the tubular heat exchanger (11) is equipped with a metal mesh with a mesh size of 5-10 mm.

10. The apparatus for waste heat recovery and reuse in drying aluminum scraps according to claim 1, characterized in that: The exhaust port of the aluminum scrap furnace (1) is connected to the straight exhaust pipe (2) by a flange, and a high-temperature resistant asbestos gasket is provided between the flange contact surfaces to prevent flue gas leakage.

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