Heat storage device and aluminum melting furnace heat storage system

Abstract

The utility model discloses a heat storage device and an aluminum melting furnace heat storage system, the heat storage device comprises a heat storage box, and the heat storage box is filled with a plurality of heat storage balls; a plurality of nozzles are arranged on at least one side wall of the heat storage tank, and the outer end parts of the nozzles are communicated with an external air source during working; a communicated ash deposition hopper is arranged below the heat storage box, a first air opening is formed in the upper portion of the side wall of the heat storage box, and a second air opening is formed in the ash deposition hopper. The technical problem that the heat storage box is blocked by accumulated ash is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas waste heat recovery, and in particular relates to a heat storage device and a heat storage system for an aluminum melting furnace. Background Art

[0002] In the 1990s, the birth of regenerative high-temperature air combustion technology broke people's traditional concept of smelting. This technology combines the traditional combustion system with the waste heat recovery process. It has the characteristics of extreme recovery of flue gas heat during the smelting process. The combustion air can be preheated to 80%-90% of the flue gas temperature, that is, the temperature reaches about 1000℃, and the exhaust temperature drops to about 200℃. The recovery rate of flue gas waste heat is increased to 60%-80%, thus greatly reducing the smelting fuel consumption. Among them, the key equipment heat storage box is widely used.

[0003] After several years of development, existing aluminum melting furnaces basically adopt regenerative combustion, and the furnace body is usually equipped with one or more regenerative boxes. In order to further save energy, some companies have cancelled the auxiliary exhaust pipes of the furnace body, and the flue gas in the furnace is discharged through the regenerative box. Therefore, it is necessary to increase the volume of the regenerative box to fully recover the waste heat resources of the flue gas. However, due to the complex composition of aluminum smelting flue gas and the large flue gas flow rate, the regenerative box generally has problems such as easy ash accumulation and blockage, rapid decline in heat storage capacity, short ball replacement cycle, and inconvenient ball replacement operation. At the same time, the ball replacement and daily operation and maintenance of the regenerative box require a lot of economic costs, and are accompanied by the risk of high-temperature operation. Utility Model Content

[0004] In view of the current technical problems, the utility model aims to provide a heat storage device and a heat storage system for an aluminum melting furnace. The heat storage device can effectively solve the technical problem of ash blockage in the heat storage box.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A heat storage device comprises a heat storage box filled with a plurality of heat storage balls; the structure is characterized in that: a plurality of nozzles are arranged on at least one side wall of the heat storage box, and the outer ends of the nozzles are connected to an external air source during operation; a connected ash hopper is arranged below the heat storage box, a first air outlet is arranged on the upper part of the side wall of the heat storage box, and a second air outlet is arranged on the ash hopper.

[0007] When the heat storage device is in the heat storage state, the high-temperature flue gas in the aluminum melting furnace enters the heat storage box through the first air port, and is discharged to the chimney through the second air port after heat exchange with the internal heat storage balls. When the heat storage device is in the heat release state, the air sent by the blower enters the heat storage box through the second air port, and is sent into the aluminum melting furnace through the first air port after heat exchange with the internal heat storage balls. When there is a lot of dust on the heat storage balls and they need to be cleaned, compressed air is filled into the nozzle through an external air source, and the compressed air is used to disturb the heat storage balls inside the heat storage box at a high speed to flush the dust on the surface of the balls and avoid the balls from sticking, thereby effectively solving the problem of dust blockage in the heat storage box, effectively improving the heat storage capacity of the heat storage balls within a certain period, and extending the service life of the balls and the single ball replacement cycle.

[0008] Preferably, the nozzle is arranged at one end in the heat storage tank to be tilted upwards, with a tilt angle of 28° to 38°. Setting a certain tilt angle allows compressed air to be blown into the tank at a certain angle and speed, thereby improving the blowing efficiency.

[0009] Preferably, the nozzle is of a Venturi tube type.

[0010] Preferably, a grille is provided at the bottom of the heat storage box, and the heat storage balls are placed on the grille; the grille is tilted, and a second door connected to the heat storage box side wall is provided, and the second door is located at the slope foot of the grille. The grille can effectively separate the heat storage balls and dust. When the heat storage box reaches the single operation limit and needs to replace the heat storage balls, the second door is opened, and the external air source fills the nozzle with compressed air to purge the heat storage balls in the box, and the balls slide out naturally from the second door, thereby shortening the ball replacement time and improving the convenience of ball replacement.

[0011] Preferably, the inclination angle of the grille mesh is 25° to 40°.

[0012] Specifically, a plurality of nozzles are provided on the four side walls of the heat storage tank, and the plurality of nozzles are arranged along the height direction of the heat storage tank.

[0013] Preferably, the top of the heat storage box is an open structure, and a detachably connected cover is provided at the opening structure, and a rotatably connected third door is provided on the cover. The detachably connected cover can facilitate opening the heat storage box for inspection and maintenance. When it is necessary to add heat storage balls into the heat storage box, the third door can be opened.

[0014] Preferably, the ash hopper is provided with a first door, which is rotatably connected to the side wall of the ash hopper. The dust on the surface of the heat storage ball is blown down into the ash hopper below, and the dust in the ash hopper can be cleaned by opening the first door.

[0015] Preferably, the side wall of the heat storage tank is provided with a first pressure probe and a first temperature probe, and the ash hopper is provided with a second pressure probe and a second temperature probe; the outer end of the nozzle is connected to the external gas source through an air charging pipe, and the air charging pipe is provided with a solenoid valve, and the solenoid valve, the first pressure probe, the first temperature probe, the second pressure probe and the second temperature probe are all electrically connected to the PLC control module. The first pressure probe, the first temperature probe, the second pressure probe and the second temperature probe can monitor the real-time data of the temperature and pressure of the upper and lower parts of the heat storage tank, and the PLC control module analyzes the data to determine the operating state of the heat storage tank, thereby controlling the opening and closing of the solenoid valve.

[0016] Based on the same inventive concept, the utility model also provides an aluminum melting furnace heat storage system, including an aluminum melting furnace, a chimney and the heat storage device as described above, the first air outlet is connected to the aluminum melting furnace, and the second air outlet is connected to the chimney or the blower through a pipeline.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows: the heat storage device and the heat storage system of the aluminum melting furnace of the utility model collect the temperature and pressure parameters inside the box and perform data analysis, so as to grasp the operation status of the box, use compressed air to perform high-speed disturbance on the heat storage balls inside the heat storage box, flush the dust on the surface of the balls, avoid the adhesion of the balls, effectively improve the heat storage capacity of the heat storage balls within a certain period, and extend the service life of the balls. At the same time, the inclined grid mesh design is adopted to separate the balls from dust, increase the inertial force of the balls sliding during the ball changing stage, reduce the difficulty of manual operation, and optimize the production and operation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the heat storage device of the utility model;

[0019] Figure 2 for Figure 1 Schematic diagram of the left view structure;

[0020] Figure 3 for Figure 1 A rear view structural diagram of ;

[0021] Figure 4 for Figure 1 A schematic diagram of a top view structure;

[0022] Figure 5 for Figure 1 Schematic diagram of the middle grid structure.

[0023] In the figure:

[0024] 1-inflating pipe, 2-solenoid valve, 3-first door, 4-second door, 5-nozzle, 6-first air outlet, 7-heat storage box, 8-fixing bolt, 9-third door, 10-grid, 11-second air outlet, 12-PLC control module, 13-first pressure probe, 14-first temperature probe, 15-second temperature probe, 16-second pressure probe, 17-heat storage ball, 18-ash hopper, 19-cover. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following text, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0026] like Figure 1 As shown, this embodiment provides a heat storage device, including a heat storage tank 7 and a PLC control module 12. The heat storage tank 7 is filled with a plurality of heat storage balls 17, and the diameter of the heat storage balls 17 is 22-28 mm. The top of the heat storage tank 7 is an open structure, and a cover 19 is provided at the opening structure. The cover 19 is detachably fixed to the heat storage tank 7 by fixing bolts 8. A third door 9 is rotatably connected to the cover 19. When it is necessary to add heat storage balls 17 to the heat storage tank 7, the third door 9 can be opened. Figure 1 and Figure 2 As shown, a plurality of nozzles 5 are provided on the four side walls of the heat storage tank 7, and the plurality of nozzles 5 are arranged along the height direction of the heat storage tank 1. The outer end of the nozzle 5 is connected to the external air source through the inflation pipe 1, and the inflation pipe 1 is provided with a solenoid valve 2. The nozzle 5 is a venturi tube, and one end of the nozzle 5 located in the heat storage tank 7 is tilted upward, and the tilt angle is 35°. An ash hopper 18 is provided under the heat storage tank 1, and a first door 3 is provided on the ash hopper 18, and the first door 3 is rotatably connected to the side wall of the ash hopper 18. When the ash hopper 18 needs to be cleaned, the first door 3 is opened to carry out the cleaning operation, and the first door 3 is closed after the cleaning operation is completed. As shown Figure 1 and Figure 4 As shown, the upper part of the side wall of the heat storage tank 7 is provided with a first air port 6, and the ash hopper 18 is provided with a second air port 11. Figure 1 and Figure 5 As shown, a grille 10 is provided at the bottom of the heat storage tank 7, and the heat storage balls 17 are placed on the grille 10. The grille 10 is tilted at an angle of 30°. A second door 4 is rotatably connected to the side wall of the heat storage tank 7, and the second door 4 is located at the foot of the grille 10. When the ball replacement operation is required, the second door 4 is opened, and the second door 4 is closed after the ball replacement operation is completed. Figure 3As shown, a first pressure probe 13 and a first temperature probe 14 are provided on the side wall of the heat storage tank 7, a second pressure probe 16 and a second temperature probe 15 are provided on the ash hopper 18, and the first pressure probe 13, the first temperature probe 14, the second pressure probe 16 and the second temperature probe 15 are all electrically connected to the PLC control module 12. The pressure probe and the temperature probe provided at the inlet and outlet of the heat storage device are used to monitor the temperature and pressure parameters of the heat storage tank in real time, and the data is analyzed through the PLC control module 12, so as to grasp the operating status of the heat storage tank 7 and realize refined management.

[0027] A heat storage system for an aluminum melting furnace comprises an aluminum melting furnace, a chimney and a heat storage device, wherein a first air port 6 is connected to the aluminum melting furnace, and a second air port 11 is connected to the chimney or a blower through a pipeline.

[0028] When the heat storage device is in the heat storage state, the high-temperature flue gas in the aluminum melting furnace enters the heat storage box 7 through the first air port 6, and is discharged to the chimney through the second air port 11 after heat exchange with the internal heat storage ball 17. When the heat storage device is in the heat release state, the air sent by the blower enters through the second air port 11, and is sent into the aluminum melting furnace through the first air port 6 after heat exchange with the internal heat storage ball 17.

[0029] The PLC control module 12 is used to associate the system operation status. When the pressure difference between the inlet and outlet of the heat storage box exceeds the set value, the solenoid valve 2 is opened, and the external air source fills the heat storage box 7 with compressed air through the air charging pipe 1. The recoil purge is performed at 20 seconds per time. The four sides of the box are divided into four groups for alternating purge, thereby reducing the dust on the surface of the ball and the adhesion between the balls, and extending the single ball replacement cycle of the heat storage device. Every 10-15 smelting furnaces, open the first door 3 at the bottom to clean the dust accumulated in the dust hopper 18.

[0030] After the heat storage device has been running for a period of time, when the pressure difference and temperature difference at the inlet and outlet of the heat storage box reach the set critical values, the system prompts that the heat storage ball 17 has reached the replacement cycle. At this time, when the furnace is shut down, the solenoid valve 2 is opened, and the external air source fills the heat storage box 7 with compressed air through the charging pipe 1. At the same time, the second door 4 is opened, so that the heat storage ball 17 inside the box is agitated by the compressed air and slides out of the box from the second door 4, which increases the convenience of changing the ball.

[0031] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A heat storage device, comprising a heat storage box (7), wherein a plurality of heat storage balls (17) are filled in the heat storage box (7); characterized in that: A plurality of nozzles (5) are provided on at least one side wall of the heat storage tank (7), and the outer ends of the nozzles (5) are connected to an external air source during operation; A connected ash hopper (18) is provided below the heat storage box (7), a first air port (6) is provided on the upper part of the side wall of the heat storage box (7), and a second air port (11) is provided on the ash hopper (18).

2. The heat storage device according to claim 1, characterized in that: One end of the nozzle (5) located in the heat storage tank (7) is arranged to be tilted upward, with an inclination angle of 28° to 38°.

3. The heat storage device according to claim 2, characterized in that: The nozzle (5) is of a venturi type.

4. The heat storage device according to claim 1, characterized in that: A grille (10) is provided at the bottom of the heat storage box (7), and the heat storage ball (17) is placed on the grille (10); the grille (10) is arranged obliquely, and a second door (4) which is rotatably connected is provided on the side wall of the heat storage box (7), and the second door (4) is located at the foot of the slope of the grille (10).

5. The heat storage device according to claim 4, characterized in that: The inclination angle of the grille mesh (10) is 25° to 40°.

6. The heat storage device according to claim 1, characterized in that: A plurality of nozzles (5) are provided on each of the four side walls of the heat storage box (7), and the plurality of nozzles (5) are arranged along the height direction of the heat storage box (7).

7. The heat storage device according to claim 1, characterized in that: The top of the heat storage box (7) is an open structure, and a detachably connected cover body (19) is provided at the opening structure, and a rotatably connected third door (9) is provided on the cover body (19).

8. The heat storage device according to claim 1, characterized in that: The ash hopper (18) is provided with a first door (3), and the first door (3) is rotatably connected to the side wall of the ash hopper (18).

9. The heat storage device according to any one of claims 1 to 8, characterized in that: A first pressure probe (13) and a first temperature probe (14) are provided on the side wall of the heat storage tank (7), and a second pressure probe (16) and a second temperature probe (15) are provided on the ash hopper (18); the outer end of the nozzle (5) is connected to an external air source through an air charging pipe (1), and an electromagnetic valve (2) is provided on the air charging pipe (1); the electromagnetic valve (2), the first pressure probe (13), the first temperature probe (14), the second pressure probe (16) and the second temperature probe (15) are all electrically connected to a PLC control module (12).

10. A heat storage system for an aluminum melting furnace, comprising an aluminum melting furnace and a chimney, characterized in that: It also includes the heat storage device as claimed in any one of claims 1 to 9, wherein the first tuyere (6) is connected to the aluminum melting furnace, and the second tuyere (11) is connected to the chimney or the blower through a pipeline.

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