Annealing furnace top heating device

Abstract

The application discloses an annealing furnace top heating device, which comprises a top cover, a cavity arranged in the middle of the top cover, a plurality of spray pipes arranged at the bottom of the cavity and communicated with the outside of the lower side of the top cover, a gas pipe arranged at the top of the cavity and communicated with the outside of the upper side of the top cover, an oxygen pipe communicated with the side wall of the gas pipe, an auxiliary gas pipe assembly composed of branch pipes, a ring-shaped gas collecting pipe and a main pipe, the branch pipes being a plurality of, the lower end of each branch pipe being communicated with the outside of the lower side of the top cover and the upper end of each branch pipe being communicated with the gas collecting pipe, the gas collecting pipe being arranged in the cavity and the side wall of the gas collecting pipe being communicated with one end of the main pipe, the other end of the main pipe being arranged outside the top cover and provided with a gas source interface, and the lower ends of the plurality of spray pipes and the plurality of branch pipes being uniformly distributed on the lower surface of the top cover. The application uses the gas heating mode, sprays the flame downward, and can ensure the stability of the flame, thereby having the advantages of low cost and reliable work.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrolytic aluminum production, and particularly relates to an annealing furnace top heating device. BACKGROUND

[0002] In the electrolytic aluminum industry, according to the current cathode pouring development trend, the annealing furnace can be used to replace the large carbon block heating pouring. However, the existing annealing furnace only has bottom heating and side heating, is usually used for casting tempering annealing, lacks top heating, and cannot meet the cathode heating requirements. In order to avoid repeated investment and save costs, it is expected to upgrade and transform the existing annealing furnace to have the function of top heating and adapt to the needs of cathode carbon block heating. Therefore, the commonly used technical means includes installing electric heating wires on the furnace top cover, but the carbon block is a poor conductor of heat, which leads to a long heating time and high power consumption and cost. In the prior art, the gas heating method is also used. However, the gas heating needs to face the problem that in order to avoid oxidation of the carbon block, the ratio of gas to oxygen needs to be accurately controlled to enable the oxygen to be fully consumed. Further, the gas is usually in a state of oxygen-deficient combustion, especially in the combustion stage after the gas enters the furnace body, it is difficult to control the combustion flame state, the flame is unstable, and the flameout phenomenon is prone to occur. SUMMARY

[0003] In order to overcome the deficiencies in the background art, the application provides an annealing furnace top heating device, which aims to use the gas heating method to set a spraying mechanism on the lower surface of the top cover, spray the flame downward from the top of the furnace body, and ensure the stability of the flame.

[0004] To achieve the above-mentioned purpose, the application provides the following technical scheme:

[0005] An annealing furnace top heating device comprises a top cover used for buckling on the upper end of a furnace body; a cavity is arranged in the middle of the top cover, a plurality of spray pipes are arranged on the bottom of the cavity and communicate with the outside of the lower side of the top cover, and a gas pipe is arranged on the top of the cavity and communicates with the outside of the upper side of the top cover; an oxygen pipe is communicated with the side wall of the gas pipe;

[0006] The device further comprises an auxiliary gas pipe assembly; the auxiliary gas pipe assembly comprises a branch pipe, an annular gas collecting pipe and a main pipe; the branch pipe is provided in plurality; the lower end of each branch pipe is communicated with the outside of the lower side of the top cover, and the upper end of each branch pipe is communicated with the gas collecting pipe; the gas collecting pipe is arranged in the cavity, and the side wall of the gas collecting pipe is communicated with one end of the main pipe; the other end of the main pipe is located outside the top cover and is provided with a gas source interface;

[0007] The lower ends of the plurality of spray pipes and the plurality of branch pipes are uniformly distributed on the lower surface of the top cover.

[0008] As a further optimization, a cooling water channel is provided at the lower part of the top cover; the top cover is also provided with an inlet and an outlet that connect to the cooling water channel.

[0009] As a further optimization, both the nozzle and the branch pipe extend through the cooling water channel.

[0010] As a further optimization, an exhaust pipe is also included; the exhaust pipe runs through the top cover from bottom to top, and its upper end is connected to a flue gas collection pipe; a valve is provided on the exhaust pipe located on the upper outside of the top cover.

[0011] As a further optimization, an ignition mechanism is also included; the ignition mechanism is detachably inserted into a pre-set hole in the top cover, with its lower end extending outside the lower side of the top cover, for igniting the gas ejected from the lower end of the nozzle.

[0012] As a further optimization, a clip is provided around the lower surface of the top cover, and the clip can be inserted into a pre-set slot at the upper end of the furnace body of the annealing furnace.

[0013] As a further optimization, the top cover is provided with lifting lugs for connecting lifting equipment.

[0014] As a further optimization, the gas source interface is connected to oxygen; the gas source interface is also equipped with a control valve to control the input amount of oxygen.

[0015] The beneficial effects of this invention are as follows:

[0016] (1) Gas heating is fast, efficient and low cost.

[0017] (2) Simply replace the top cover on the furnace body to give it a top heating function, which is suitable for upgrading and transforming old furnace bodies.

[0018] (3) The gas burns completely, the flame is stable and not easy to go out, and there is less unconsumed oxygen, which reduces the oxidation of the heated items in the furnace.

[0019] In summary, this device uses gas heating to spray flames downwards and ensures a stable flame, thus offering advantages such as low cost and reliable operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0021] Figure 2 for Figure 1 A magnified view of part A.

[0022] In the diagram: 1 Top cover, 11 Clip head, 12 Lifting lug, 2 Cavity, 21 Nozzle, 22 Gas pipe, 23 Oxygen pipe, 31 Branch pipe, 32 Gas collection pipe, 33 Main pipe, 331 Gas source interface, 4 Cooling water channel, 41 Water inlet, 41 Water outlet, 5 Exhaust pipe, 51 Flue gas collection pipe, 52 Valve, 6 Ignition mechanism, 7 Furnace body, 71 Slot, 72 Electric heating wire, 8 Cathode carbon block. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some preferred embodiments of the present invention, and not all embodiments. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] Example 1: Please refer to Figures 1-2 ;

[0025] This invention provides the following technical solution: a top heating device for an annealing furnace, used to upgrade and modify an annealing furnace to enable it to have top heating functionality, adapting to the heating needs of the cathode carbon block 8. Electric heating wires 72 are provided on the inner wall and bottom surface of the furnace body 7 for heating.

[0026] The top heating device of the annealing furnace includes a top cover 1 for attaching to the upper end of the furnace body 7; thus, the top cover 1 can be used to inject gas into the furnace body 7 to heat the cathode carbon block 8 inside the furnace body 7, wherein the gas can be purified natural gas, coal gas, methane, acetylene, etc. The top cover 1 has a lifting lug 12 at its upper end for connecting lifting equipment. It is evident that the top cover 1 and the furnace body 7 are detachable. A locking head 11 is provided around the lower surface of the top cover 1, which can be inserted into a pre-set locking groove 71 at the upper end of the furnace body 7, facilitating alignment during lifting of the top cover 1.

[0027] The top cover 1 has a cavity 2 in the middle. Multiple nozzles 21 communicating with the lower exterior of the top cover 1 are located at the bottom of the cavity 2. A gas pipe 22 communicating with the upper exterior of the top cover 1 is located at the top of the cavity 2. An oxygen pipe 23 is connected to the side wall of the gas pipe 22. An auxiliary gas pipe assembly is also included. The auxiliary gas pipe assembly includes branch pipes 31, an annular gas collecting pipe 32, and a main pipe 33. Multiple branch pipes 31 are included. The lower end of each branch pipe 31 communicates with the lower exterior of the top cover 1, and its upper end communicates with the gas collecting pipe 32. The gas collecting pipe 32 is located in the cavity 2, and its side wall communicates with one end of the main pipe 33. The other end of the main pipe 33 is located outside the top cover 1 and has a gas source interface 331. The lower ends of the multiple nozzles 21 and the multiple branch pipes 31 are evenly distributed on the lower surface of the top cover 1. This results in a flattened flame and uniform heating.

[0028] Therefore, oxygen is injected into the high-pressure gas pipe 22 through the oxygen pipe 23 to form a high-pressure combustible gas mixture; the combustible gas enters the cavity 2 for further homogenization; then it is ejected through the nozzle 21 and burned, forming a jet flame on the lower surface of the top cover 1 to heat the furnace body 7. At this time, the oxygen content is not abundant, that is, the oxygen content in the combustible gas is less than or equal to the amount of oxygen required for combustion, so that the oxygen can be fully consumed. However, in order to ensure flame stability, the auxiliary gas pipe assembly blows a small amount of combustion-supporting gas into the flame through the branch pipe 31 during the combustion stage, thereby maintaining the flame stability and preventing flameout. At this time, the combustion-supporting gas can be purified oxygen or air. It can be seen that the oxygen reacts with the gas in two stages, especially in the second stage when the oxygen is ejected from the branch pipe 31, because the temperature of the already burned gas is high at this time, and the gas molecules are already in an active state. The oxygen added at this time has also been heated by the flame, so it is easier to react with the gas and thus the amount of oxygen injected can be reduced.

[0029] At this point, the top cover 1 experiences a high temperature, reaching 500-800℃. To ensure the reliability of the top cover 1, a cooling water channel 4 is provided at the lower part of the top cover 1. The top cover 1 is also provided with an inlet 41 and an outlet 42 connecting the cooling water channel 4. The cooling water channel 4 can optionally bypass the nozzle 21 and the branch pipe 31, thus the cooling water channel 4 is naturally completely closed, cooling the lower end of the top cover 1 through heat conduction. However, a more preferred embodiment is that both the nozzle 21 and the branch pipe 31 penetrate the cooling water channel 4. This allows the cooling water in the cooling water channel 4 to surround the side walls of the nozzle 21 and the branch pipe 31, resulting in better cooling effect and ensuring that the high temperature is not transferred to the combustible gas in the cavity 2, thus avoiding deflagration.

[0030] As the temperature of the furnace body 7 rises, the exhaust gas from the combustion of the gas and the flue gas generated after heating the charcoal blocks 8 will increase the pressure inside the furnace body 7, requiring pressure reduction and exhaust. Exhaust facilities can generally be connected to the side wall of the furnace body 7. However, a better option is to install exhaust facilities on the top cover 1 to allow the small amount of oxygen that has not yet participated in combustion to be discharged early, avoiding contact with the charcoal blocks 8. The top cover 1 also includes an exhaust pipe 5; the exhaust pipe 5 runs through the top cover 1 from bottom to top, and its upper end is connected to a flue gas collection pipe 51; the flue gas collection pipe 51 is connected to a purification device, and the exhaust gas is discharged after purification. A valve 52 is provided on the exhaust pipe 5 located on the upper outer side of the top cover 1 to control the discharge of excessive high-temperature gas in the initial stage of heating, thus preventing a reduction in heating efficiency.

[0031] To further improve reliability, an ignition mechanism 6 is also included; the ignition mechanism 6 is detachably inserted into a pre-set hole in the top cover 1, with its lower end extending outside the lower side of the top cover 1, for igniting the gas ejected from the lower end of the nozzle 21. Thus, in the event of flameout, re-ignition can be achieved through the ignition mechanism 6 without opening the top cover 1 at the upper end of the furnace body 7.

[0032] To more precisely control the oxygen input, a control valve is provided on the gas source interface 331 to control the oxygen input. Preferably, the control valve is an electrically controlled valve, which allows for precise control of the injection quantity of the combustion-supporting gas according to the flame size at different combustion stages.

[0033] In one usage method, connect the oxygen pipe 23, gas pipe 22, and auxiliary gas pipe assembly to the gas source and start supplying gas. Connect the water inlet 41 and outlet 42 to supply water to the cooling water channel 4 for cooling. Then, the lifting equipment lifts the top cover 1, and manual ignition is performed at the lower end of the top cover 1, causing the nozzle 21 to spray flames. The ignited top cover 1 is then hoisted onto the furnace body 7. Initially, the temperature inside the furnace body 7 is low, so the gas supply of the gas pipe 22 and oxygen pipe 23 can be increased for rapid heating. When the furnace body 7 temperature rises to approximately 500℃, the gas supply of the gas pipe 22 and oxygen pipe 23 is reduced to a low flame to save costs. The flame at the lower end of the nozzle 21 is short; at this time, auxiliary oxygen supply is provided through the auxiliary gas pipe assembly to prevent flameout. In the event of accidental flameout, it can be relit by the ignition mechanism 6 without needing to re-lift the top cover 1, thus maintaining continuous operation.

[0034] The advantages of this embodiment are:

[0035] (1) Gas heating is fast, efficient and low cost.

[0036] (2) Simply replace the top cover 1 on the furnace body 7 to give it a top heating function, which is suitable for upgrading and transforming old furnace bodies.

[0037] (3) The gas burns completely, the flame is stable and not easy to go out, and there is less unconsumed oxygen, which reduces the oxidation of the heated items in the furnace body 7.

[0038] In summary, this device uses gas heating to spray flames downwards and ensures a stable flame, thus offering advantages such as low cost and reliable operation.

[0039] The parts of this invention not described in detail are prior art; for those skilled in the art, the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A top heating device for an annealing furnace, comprising a top cover (1); characterized in that: The top cover (1) has a cavity (2) in the middle. At the bottom of the cavity (2) are multiple nozzles (21) that communicate with the lower side of the top cover (1). At the top of the cavity (2) are a gas pipe (22) that communicates with the upper side of the top cover (1). An oxygen pipe (23) is connected to the side wall of the gas pipe (22). It also includes an auxiliary airway assembly; the auxiliary airway assembly includes a branch pipe (31), an annular gas collecting pipe (32) and a main pipe (33); there are multiple branch pipes (31); the lower end of each branch pipe (31) is connected to the lower outside of the top cover (1), and its upper end is connected to the gas collecting pipe (32); the gas collecting pipe (32) is disposed in the cavity (2), and its side wall is connected to one end of the main pipe (33); the other end of the main pipe (33) is located outside the top cover (1) and is provided with an air source interface (331); The lower ends of the plurality of nozzles (21) and the plurality of branch pipes (31) are evenly distributed on the lower surface of the top cover (1).

2. The annealing furnace top heating device according to claim 1, characterized in that: A cooling water channel (4) is also provided at the lower part of the top cover (1); an inlet (41) and an outlet (42) connecting the cooling water channel (4) are also provided on the top cover (1).

3. The annealing furnace top heating device according to claim 2, characterized in that: Both the nozzle (21) and the branch pipe (31) pass through the cooling water channel (4).

4. The annealing furnace top heating device according to claim 3, characterized in that: It also includes an exhaust pipe (5); the exhaust pipe (5) runs through the top cover (1) from bottom to top, and its upper end is connected to the flue gas collection pipe (51); a valve (52) is provided on the exhaust pipe (5) located on the upper outside of the top cover (1).

5. The annealing furnace top heating device according to claim 4, characterized in that: It also includes an ignition mechanism (6); the ignition mechanism (6) is detachably inserted into a pre-set hole in the top cover (1), and its lower end extends out of the lower side of the top cover (1) to ignite the gas ejected from the lower end of the nozzle (21).

6. The annealing furnace top heating device according to claim 5, characterized in that: The lower surface of the top cover (1) is provided with a clip (11) around the periphery, and the clip (11) can be inserted into a pre-set slot at the upper end of the furnace body (7) of the annealing furnace.

7. The annealing furnace top heating device according to claim 6, characterized in that: The top cover (1) is provided with a lifting lug (12) at the upper end for connecting lifting equipment.

8. The annealing furnace top heating device according to any one of claims 1-7, characterized in that: The gas source interface (331) is connected to oxygen; the gas source interface (331) is also equipped with a control valve to control the input amount of oxygen.

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