Anode scrap waste heat recovery device

Abstract

The utility model discloses a residual anode waste heat recovery device, which comprises a box body for accommodating residual anodes and new anodes, and a sealing door arranged at one end of the box body, and is characterized in that the upper part of the box body is provided with a moving channel for guide rods of the residual anodes and the new anodes, and the left side and the right side of the moving channel are provided with steel brushes for automatically sealing the moving channel; a supporting plate is arranged at the bottom in the box body, and a phase change energy storage layer is arranged below the supporting plate; the anode scrap recycling device can recycle the anode scrap, preheat and heat a new anode, reduces a large amount of energy waste in the aluminum electrolysis process, improves the production stability of an electrolytic bath, increases the energy efficiency, reduces the energy consumption, improves the economical efficiency, and reduces the influence of harmful gas and dust released by the open anode scrap in a workshop on the environment to a certain extent.

Description

Technical Field

[0001] The utility model relates to a residual anode waste heat recovery device, belonging to the field of residual anode waste heat recovery tools. Background Art

[0002] During the aluminum electrolysis production process, the anode is continuously consumed as the electrochemical reaction proceeds, and the carbon anode needs to be replaced regularly. The anode replacement work has become an important operation content in the aluminum smelting process. Currently, for the anode replacement process, the following problems exist:

[0003] First, the residual anode takes away a large amount of heat from the electrolytic cell; the temperature of the replaced hot residual anode is generally about 800 degrees Celsius, taking away a large amount of heat from the electrolytic cell. If it is placed in the electrolysis workshop for natural cooling, the heat will be released into the environment. At the same time, the fluorides contained in the residual anode will react with water vapor in the air to generate HF gas, which is highly toxic. Research shows that the fluorides generated by the residual anodes in the electrolysis workshop account for about 1 / 3 of the fluorides discharged from the electrolysis workshop, and the weight converted is about 0.2 kgF / t-Al. Preliminary calculations show that the heat taken away by the residual anode per unit of primary aluminum is equivalent to about 6 kg of standard coal.

[0004] Second, the heating time of the new anode is long, affecting the cell condition; after the cold new anode is placed in the electrolytic cell, it needs to be heated to a sufficient temperature by the heat in the cell to conduct electricity, which requires additional energy consumption. However, during the anode replacement process, after the anode enters the electrolytic cell, it needs to absorb a large amount of heat from the electrolytic cell to gradually rise from room temperature to the normal production temperature of electrolysis, which has a serious negative impact on the stability, heat balance, current efficiency, anode current distribution, etc. of the electrolytic cell, and greatly interferes with the normal production of the electrolytic cell.

[0005] That is, there is a need for a residual anode waste heat recovery device that can recover the waste heat of the residual anode and preheat and heat the new anode, reduce a large amount of energy waste in the aluminum electrolysis process, improve the production stability of the electrolytic cell and increase the energy efficiency, reduce energy consumption and improve the economy, and to a certain extent reduce the impact of harmful gases and dust released by the open residual anodes in the workshop on the environment. Summary of the Invention

[0006] In view of this, the purpose of the utility model is to provide a residual anode waste heat recovery device that can recover the waste heat of the residual anode and preheat and heat the new anode, reduce a large amount of energy waste in the aluminum electrolysis process, improve the production stability of the electrolytic cell and increase the energy efficiency, reduce energy consumption and improve the economy, and to a certain extent reduce the impact of harmful gases and dust released by the open residual anodes in the workshop on the environment; it can overcome the deficiencies of the prior art.

[0007] The purpose of the utility model is achieved through the following technical solutions:

[0008] The utility model discloses a residual anode waste heat recovery device, which comprises a box body for accommodating residual anodes and new anodes. A sealing door is arranged at one end of the box body. It is characterized in that a moving channel for residual anodes and new anode guide rods is arranged at the upper part of the box body. Steel brushes for automatically closing the moving channel are arranged on the left and right sides of the moving channel. A support plate is arranged at the bottom inside the box body, and a phase change energy storage layer is arranged under the support plate.

[0009] The above-mentioned device further comprises a temperature measuring hole arranged on the side wall of the box body.

[0010] The above-mentioned device has an asbestos heat insulation layer arranged on the inner wall of the box body.

[0011] The aforementioned device has a moving base arranged at the lower part of the box body.

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0013] 1. The utility model can simultaneously accommodate residual anodes and new anodes through the box body. Through the heat dissipation of the residual anodes and the heat absorption of the new anodes, the preheating of the new anodes is realized. Compared with the prior art of putting new anodes in the normal temperature state into the electrolytic cell, the preheated new anodes can reduce a large amount of energy waste in the aluminum electrolysis process, improve the production stability of the electrolytic cell and increase the energy efficiency, reduce the energy consumption and improve the economy, and to a certain extent reduce the impact of harmful gases and dust released by the open residual anodes in the workshop on the environment. Specifically, by setting the moving channel, it is convenient to load and unload the residual anodes and new anodes into the box body by hoisting. Moreover, after the guide rods of the residual anodes and new anodes pass through, the steel brushes can automatically close and close the moving channel to minimize the overflow of hot air. At the same time, because the heat conductivity of the support plate is poor, after the residual anodes and new anodes are placed on the support plate, the waste heat of the residual anodes is recovered and stored by using the phase change energy storage material. With the characteristics of large heat storage density and stable performance, the new anodes are stably preheated, the problem of spatio-temporal mismatch between energy supply and demand is alleviated, the comprehensive energy utilization rate is improved, and the stability and working efficiency of the aluminum electrolytic cell are improved. The phase change energy storage layer is conducive to heat conduction and can uniformly preheat the middle part of the bottom side of the new anodes.

[0014] 2. The device includes a temperature measuring hole arranged on the side wall of the box body. With such a structure, the temperature of the residual anodes and new anodes during the preheating process can be measured through the temperature measuring hole, and the conditions of the residual anodes and new anodes during the heat exchange process can be grasped.

[0015] 3. An asbestos heat insulation layer is arranged on the inner wall of the box body. In this way, the asbestos heat insulation layer can insulate the cavity inside the box body and improve the heat exchange effect.

[0016] 4. A moving base is arranged at the lower part of the box body. In this way, the moving base is conducive to the movement of the device.

[0017] 5. The waste heat recovery device is an enclosed box where the residual anodes are placed, which can reduce the heat radiation to the outside. When both the residual anodes and the new anodes are placed inside the device, there will also be heat radiation between the residual anodes and the new anodes, and the preheating effect of the new anodes will be better.

[0018] 6. In most workshops, the residual anodes are transported to the cooling workshop for natural cooling. The heat recovery rate of the residual anodes is almost zero, and the fluorides generated during the cooling period have an impact on the environment. By using a sealed heat preservation box, the fluorides and dust released by the residual anodes can be reduced, the working environment of the electrolysis workshop can be improved, and the pollutant emissions can be reduced. The feasibility of step-by-step utilization of the waste heat of the residual anodes is high. According to the characteristics of step-by-step utilization of the waste heat temperature, after the heat of the anode rods is used to preheat the anode rods, steam can be prepared for use in the alumina workshop or for refrigeration air conditioners, reducing the electricity consumption of the air conditioners.

[0019] Other advantages, objectives, and features of the present utility model will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the objectives, technical solutions, and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings, where:

[0021] Figure 1 is a schematic diagram of the three-dimensional connection structure of the present utility model.

[0022] Figure 2 is a side view of the present utility model.

[0023] Figure 3 is Figure 1 a partial enlarged structural schematic diagram of part A in

[0024] Among them, the box body 1; the sealing door 2; the moving channel 3; the steel brush 4; the asbestos heat preservation layer 5; the moving base 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will refer to the accompanying drawings to describe the preferred embodiments of the present utility model in detail. It should be understood that the preferred embodiments are only for illustrating the present utility model, rather than for limiting the protection scope of the present utility model.

[0026] As Figures 1 - 3As shown in the figure, a residual anode waste heat recovery device disclosed by the utility model includes a box body 1 for accommodating residual anodes and new anodes. A sealing door 2 is provided at one end of the box body 1. A moving channel 3 for residual anode and new anode guide rods is provided at the upper part of the box body 1. Steel brushes 4 for automatically closing the moving channel 3 are provided on the left and right sides of the moving channel 3. A pallet is provided at the bottom inside the box body 1, and a phase change energy storage layer is provided under the pallet. With such a structure, the box body 1 can accommodate residual anodes and new anodes at the same time. Through the heat dissipation of the residual anodes and the heat absorption of the new anodes, the preheating of the new anodes can be realized. Compared with the existing method of putting new anodes in the normal temperature state into the electrolytic cell, the preheated new anodes can reduce a large amount of energy waste in the aluminum electrolysis process, improve the production stability of the electrolytic cell and increase the energy efficiency, reduce energy consumption and improve the economy, and to a certain extent, reduce the impact of harmful gases and dust released by the open residual anodes in the workshop on the environment; specifically, by setting the moving channel 3, it is convenient to load and unload the residual anodes and new anodes into the box body 1 by hoisting. Moreover, after the guide rods of the residual anodes and new anodes pass through, the steel brushes 4 can automatically close and close the moving channel 3 to minimize the overflow of hot air. At the same time, because the pallet has poor thermal conductivity, after the residual anodes and new anodes are placed on the pallet, the waste heat of the residual anodes is recovered and stored by using the phase change energy storage material. With the characteristics of large heat storage density and stable performance, the new anodes are preheated stably, the problem of the mismatch between energy supply and demand in time and space is alleviated, the comprehensive energy utilization rate is improved, and the stability and working efficiency of the aluminum electrolytic cell are improved. The phase change energy storage layer is beneficial to heat conduction and can uniformly preheat the middle part of the bottom side of the new anodes.

[0027] The device includes a temperature measuring hole provided on the side wall of the box body 1. With such a structure, through the temperature measuring hole, the temperatures of the residual anodes and new anodes during the preheating process can be measured, and the conditions of the residual anodes and new anodes during the heat exchange process can be grasped.

[0028] Furthermore, an asbestos heat insulation layer 5 is provided on the inner wall of the box body 1. In this way, the asbestos heat insulation layer 5 can insulate the cavity inside the box body 1 and improve the heat exchange effect.

[0029] Furthermore, a moving base 6 is provided at the lower part of the box body 1. In this way, it is beneficial for the device to move through the moving base 6.

[0030] The method for recovering the waste heat of the residual anodes is characterized in that the method uses the box body 1 to accommodate the residual anodes to reduce the heat radiation in the working environment and avoid the reaction of fluorides contained in the residual anodes with water vapor in the air to generate harmful gases; through the box body 1, the waste heat of the residual anodes is used to preheat the new anodes, reduce the disturbance caused after the new anodes are put into the electrolytic cell and save energy, and the phase change energy storage layer is used to improve the stability and uniformity of the preheating of the new anodes.

[0031] Specifically, the method includes the measurement of the temperature of the new anodes and the measurement of the temperature of the residual anodes together with the temperature of the energy storage material.

[0032] The measurement of the temperature of the new anodes includes the following steps:

[0033] Step s1: Measure the temperature of the new anode before it is placed into the box 1. Step s2: After the new anode is placed into the box 1, measure a set of data every half an hour. The measurement includes measuring the temperature of the new anode by directly contacting the anode through the temperature measurement holes provided on the box 1, and measuring the ambient temperature inside the box 1 without contacting the anode and the box 1. Step s3: Record the data of the new anode in the box 1, and take out the new anode when the turning point of the new anode temperature appears or the new anode temperature changes slowly. Step s4: Measure the temperature of the new anode after it is taken out of the box 1.

[0034] The measurement of the spent anode temperature together with the energy storage material temperature includes the following steps:

[0035] Step s1: Measure the temperature of the spent anode before it is placed into the box 1. Step s2: After the spent anode is placed into the box 1, measure a set of data every half an hour. The measurement includes measuring the temperature of the spent anode and the energy storage material by directly contacting the anode through the temperature measurement holes provided on the box 1. Step s3: Record the data of the spent anode in the box 1, and take out the spent anode when the turning point of the spent anode temperature appears or the new anode temperature changes slowly. Step s4: Measure the temperature of the spent anode after it is taken out of the box 1.

[0036] When measuring the new anode or the spent anode, the measurement points of the new anode or the spent anode include three points at the bottom of the anode palm, one point in the middle of the anode, one point at the upper part of the anode, one point on the steel claw, and one point on the bus bar.

[0037] In production, waste heat recovery brings two aspects of benefits: heat saving and production efficiency improvement.

[0038] A: Saving part. 48 anode rods are arranged in each cell, each anode weighs about 1.3 tons, the reaction takes 36 days, including 1 day of preheating, and the temperature in the cell is about 940 °C. After 36 days of reaction, the spent anode rods at 940 °C are taken out and transported to the workshop by a special transport vehicle for natural cooling for 2 days, and then the remaining anode materials on the spent anode rods are recovered, crushed and reassembled into new anode rods. The waste heat transformation point is the heat on the high-temperature spent anode rods. After calculation, the waste heat that can be recovered from each anode rod is 188907.9 KJ, equivalent to 52.5 KWh. The total heat required for preheating the new anode rods is 1099045.8, equivalent to 305.3 KWh, and the waste heat recovery ratio is 17.2%.

[0039] B: Efficiency improvement part. After waste heat recovery, the preheating time is shortened, the electrolytic cell runs more smoothly, and the current efficiency is improved. The benefits of the efficiency improvement part need to be measured after the batch application of the spent anode waste heat recovery device is stable.

[0040] The temperature of the new anode is 10°C to 25°C, and the preheating target range of the new anode is 80°C to 100°C. Taking the example of preheating a 15°C new anode to 90°C, it can save 1.03*10^8 J of heat absorbed from the electrolytic cell, which is equivalent to reducing the power consumption of each new anode by 28.6 kwh. If calculated based on the electricity price of 0.5 yuan / kWh and 75,600 anodes being preheated, insulated, and replaced annually, the annual economic benefit of power saving can be created: 1.0811 million yuan / year.

[0041] Secondly, through the residual anode waste heat utilization technology of this project, the temperature of the new anode can be effectively increased, the moisture in the anode can be removed, the gas film resistance generated by the gasification of moisture after the wet anode is put into the cell can be avoided, the anode voltage drop can be reduced, the energy utilization efficiency can be improved, the production cost can be reduced, the competitive advantage can be enhanced. At the same time, the full-current conduction time of the anode can be greatly shortened, the stability of the electrolytic cell can be enhanced, the fluorides and dust released by the residual anode can be reduced through the sealed heat preservation box, the working environment of the electrolytic workshop can be improved, and the pollutant emissions can be reduced. See the detailed list of energy conservation of the residual anode rod in Table 1 and the total heat required for preheating the new anode rod in Table 2 below for details.

[0042] Table 1 Detailed list of energy conservation of the residual anode rod

[0043]

[0044]

[0045] Table 2 Total heat required for preheating the new anode rod

[0046]

[0047] The above description is only a preferred embodiment of the present invention, and does not impose any form of confidentiality restriction on the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical content of the present invention and the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A residual heat recovery device for residual anodes, comprising a box (1) for storing residual anodes and new anodes, a sealing door (2) being provided at one end of the box (1), characterized in that: A moving channel (3) for residual poles and new pole guide rods is provided on the upper part of the box body (1), steel brushes (4) for automatically closing the moving channel (3) are provided on the left and right sides of the moving channel (3), a support plate is provided at the bottom of the box body (1), and a phase change energy storage layer is provided under the support plate.

2. The residual heat recovery device according to claim 1, characterized in that: It also includes a temperature measuring hole provided on the side wall of the box body (1).

3. The residual heat recovery device according to claim 1, characterized in that: An asbestos insulation layer (5) is provided on the inner wall of the box body (1).

4. The residual anode waste heat recovery device according to any one of claims 1 to 3, characterized in that: A movable base (6) is provided at the lower part of the box body (1).

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