Anode roasting energy-saving furnace moving method

Abstract

The invention provides an energy-saving furnace moving method for anode roasting, which comprises the following steps of: closing a combustion frame of a furnace chamber positioned in the last flame direction in a high-temperature sintering section, and keeping other combustion frames open; a sealing baffle of the furnace chamber where the main smoke exhaust frame is located is rapidly detached and taken out; gradually opening an auxiliary smoke exhaust frame main valve and each flame path valve, and gradually closing a main smoke exhaust frame main valve until the main smoke exhaust frame main valve is completely closed; closing combustion frames of other high-temperature sintering section furnace chambers in the first step; the main smoke exhaust frame is hoisted forwards in the flame direction; starting of the combustion frames of other high-temperature sintering section furnace chambers is recovered; all flame path valves in the new main smoke exhaust frame are adjusted again, and the negative pressure of all flame paths is controlled to be the normal value; the operation of the air blowing frame and the cooling frame is stopped, after the combustion frame closed in the first step is detached, the combustion frame is hoisted and installed in the furnace chamber, located at the rearmost portion of the flame direction, of the preheating section, and combustion is recovered; the zero-pressure frame is moved forwards by one furnace chamber; and the blast frame and the cooling frame respectively move forwards by one furnace chamber. The furnace moving operation time is greatly shortened, and energy consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum smelting, and in particular to an energy-saving furnace moving method for anode roasting. Background Art

[0002] Prebaked anodes are made from petroleum coke as the aggregate and coal tar pitch as the binder. They are used as anode materials in prebaked aluminum electrolytic cells. These carbon blocks have been calcined to achieve a stable geometric shape, hence the name prebaked anode carbon blocks. They are also commonly referred to as carbon anodes for aluminum electrolysis. Aluminum electrolytic cells using prebaked anode carbon blocks as anodes are called prebaked anode electrolytic cells, or simply prebaked cells. These are modern, large-scale aluminum electrolytic cells. Prebaked anodes are manufactured using petroleum coke as the raw material and coal tar pitch as the binder. The process includes petroleum coke calcination, secondary crushing, screening, fine crushing, pitch melting, batching, kneading, molding, and calcining.

[0003] The open ring anode baking furnace is the most commonly used heat treatment kiln in the production process of pre-baked anodes. It consists of several furnace chambers with the same structure arranged in double rows. The two rows of furnace chambers at the end are connected by a connecting flue, forming a head-to-end connection. It operates according to a moving flame system to perform baking heat treatment on pressed raw products.

[0004] During the anode baking process, each component of the flame system must be moved after each baking cycle. Open-ring baking furnaces generally utilize an intermittent negative pressure method for moving the furnace, which involves moving the exhaust rack, combustion rack, and temperature and pressure measurement racks. The entire moving process takes 40 to 50 minutes. During this time, the system loses negative pressure, allowing a large amount of volatiles to escape, polluting the operating environment and absorbing a significant amount of heat. Furthermore, the combustion rack remains idle for a long time during the move, significantly reducing the temperature of the fire channel and increasing energy consumption. Summary of the Invention

[0005] The present invention aims to provide an energy-saving furnace moving method for anode roasting. During the furnace moving process, the method has uninterrupted negative pressure, simple operation, greatly shortens the furnace moving operation time, and effectively reduces the temperature drop of the fire channel.

[0006] The technical solutions of the present invention are as follows: The anode baking furnace targeted by the present invention generally consists of 18 or more furnace chambers with the same structure. Each furnace chamber is divided into a sealing section, a preheating section, a high-temperature sintering section, and a cooling section according to the production stage. The sealing section, preheating section, high-temperature sintering section, and cooling section are connected in sequence. Among them, the furnace chamber where the main smoke exhaust rack is located is the first furnace chamber of the preheating section, and a temperature and pressure measuring rack is provided in the furnace chamber; the furnace chamber where the auxiliary smoke exhaust rack is located is the last furnace chamber of the sealing section; the furnace chamber where the combustion rack is located is the furnace chamber of the high-temperature sintering section; the furnace chamber after the furnace chamber where the last combustion rack is located is the cooling section, the zero pressure rack is provided on the first furnace chamber of the cooling section, the blast rack is provided on the furnace chamber in the middle of the cooling section, and the cooling rack is provided on the furnace chamber at the rear of the cooling section. The energy-saving anode baking furnace moving method comprises the following steps: A. Close the combustion rack of the last furnace chamber in the high-temperature sintering section in the direction of flame movement, and keep the combustion racks of the other high-temperature sintering section furnace chambers open normally; B. Quickly disassemble and remove the sealing baffle of the furnace chamber where the main exhaust rack is located; C. Open the auxiliary smoke exhaust rack main valve to the maximum at a uniform speed, then open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, and at the same time close the main smoke exhaust rack main valve to half at a uniform speed. During the operation, keep the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section above -100Pa; D. Further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so that the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section reaches -120Pa±5Pa; close the main valve of the main smoke exhaust rack at a uniform speed until it is completely closed. At the same time, further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so that the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section is maintained at -125Pa±5Pa; E. Remove the signal line of the main smoke exhaust rack, take out the thermocouple of the temperature and pressure measuring rack, and cover the fire channel cover corresponding to the thermocouple; F. Close the combustion racks of the other high-temperature sintering furnace chambers in step A, then hoist the main exhaust rack forward along the flame direction to the adjacent furnace chamber before the auxiliary exhaust rack, quickly close the fire channel cover of the corresponding furnace chamber of the main exhaust rack, and then immediately resume the operation of the combustion racks of the other high-temperature sintering furnace chambers; move the temperature and pressure measuring racks and install them to the furnace chamber where the auxiliary exhaust rack was originally located; at this time, the original main exhaust rack becomes the auxiliary exhaust rack, and the original auxiliary exhaust rack becomes the main exhaust rack; G. Quickly install the sealing baffle taken out in operation B to the furnace room where the new auxiliary exhaust rack is located; H. Install the signal line of the new main smoke exhaust rack, readjust the valves of each fire channel in the new main smoke exhaust rack, and control the negative pressure of each fire channel on the temperature and pressure measuring rack to the normal value; I. Stop the operation of the blast rack and cooling rack, dismantle the combustion rack and zero pressure rack closed in step A, then hoist the combustion rack and install it in the furnace chamber at the rear of the flame direction in the preheating section, and quickly resume combustion on the combustion rack; J. Move the zero pressure rack forward one furnace chamber and install it; K. Lift the blast rack and cooling rack and move them forward one furnace chamber respectively, install them and restore them to work.

[0007] Before carrying out step A, open the agricultural film on the furnace chamber at the rear of the flame in the preheating section and lay the filling coke covering material.

[0008] In the step E, while taking out the thermocouple of the temperature and pressure measuring frame, quickly cover the fire channel cover corresponding to the thermocouple; In the step I, after the combustion rack is hoisted, the thermocouples and natural gas burners of each fire channel are placed in the corresponding fire channel openings, the natural gas, power supply, and signal lines are connected, and the work of the combustion rack can be started after confirming that the negative pressure of the temperature and pressure measuring rack is above -100 Pa.

[0009] The present invention has the following beneficial effects: During the furnace moving process, the method of the present invention maintains uninterrupted negative pressure, the natural gas is stopped for a very short time, and standardized furnace moving operation steps are formed, thereby reducing the overflow of volatiles, the drop in fire channel temperature and the consumption of natural gas during the furnace moving process, shortening the furnace moving time by more than 20 minutes, and having good application prospects. DETAILED DESCRIPTION

[0010] The present invention is described in detail below with reference to the embodiments. Example 1

[0011] Energy-saving furnace transfer method for anode baking; The large-scale prebaked anode production is carried out using an anode baking furnace. The furnace chambers of the anode baking furnace are divided into a preheating section, a high-temperature sintering section, and a cooling section according to the production stage. The preheating section is provided with X sequentially connected heating stage furnace chambers, the high-temperature sintering section is provided with Y sequentially connected high-temperature sintering stage furnace chambers, and the cooling section is provided with Z sequentially connected cooling furnace chambers; X=3, Y=3, Z=7; A combustion rack is installed in each high-temperature sintering stage furnace chamber; a main exhaust rack is installed in the first furnace chamber of the preheating section, namely the 1p furnace chamber; an auxiliary exhaust rack is added in the sealed furnace chamber adjacent to the 1p furnace chamber. At the initial operation of the equipment, the main valve of the auxiliary exhaust rack and the valves corresponding to each fire channel are closed; A blast rack is provided in the cooling furnace chamber in the middle of the cooling section for blasting air.

[0012] Take an open ring anode baking furnace composed of 54 furnace chambers of the same structure as an example. Every 18 furnace chambers form a flame system. Each furnace chamber of each flame system is divided into a sealing section, a preheating section, a high-temperature sintering section, and a cooling section according to the production stage. The sealing section, preheating section, high-temperature sintering section, and cooling section are connected in sequence. The sealing section is located in chambers 1P and 2P, the preheating section is located in chambers 3-5P, the high-temperature sintering section is located in chambers 6-8P, the cooling section is located in chambers 9-15P, and chambers 16-18P are the working chambers. The main exhaust system is located in chamber 3P, where a temperature and pressure measuring system is installed. The auxiliary exhaust system is located in chamber 2P; the combustion system is located in chambers 6-8P, and the zero-pressure system is located in chamber 9P; the blast system is located in chamber 12P, and the cooling systems are located in chambers 14P and 15P.

[0013] The energy-saving anode baking furnace moving method comprises the following steps: A. Remove the plastic film on the furnace chamber 5P at the rear of the flame in the preheating section and lay the filling coke covering material; close the combustion rack of the furnace chamber 8P at the rear of the flame in the high-temperature sintering section, and keep the combustion racks of the furnace chambers 6P and 7P open normally; B. Quickly disassemble and remove the sealing baffle of the furnace chamber 2P where the main smoke exhaust rack is located; C. Open the auxiliary smoke exhaust rack main valve to the maximum at a uniform speed, then open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, and at the same time close the main smoke exhaust rack main valve to half at a uniform speed. During the operation, keep the negative pressure value of each fire channel on the 3P temperature and pressure measuring rack in the furnace room above -100Pa; D. Further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so that the negative pressure value of each fire channel on the 3P temperature and pressure measuring rack in the furnace room reaches -120Pa±5Pa; close the main valve of the main smoke exhaust rack at a uniform speed until it is completely closed. At the same time, further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so as to maintain the negative pressure value of each fire channel on the 3P temperature and pressure measuring rack in the furnace room at -125Pa±5Pa; E. Remove the signal line of the main smoke exhaust rack, and at the same time remove the thermocouple of the temperature and pressure measuring rack, and cover the fire channel cover corresponding to the thermocouple; F. Close the combustion racks of other high-temperature sintering furnace chambers in step A, namely furnace chambers 6P and 7P, and then hoist the main exhaust rack forward along the flame direction and install it in the adjacent furnace chamber before the auxiliary exhaust rack, namely 1P. Quickly close the fire outlet cover corresponding to the main exhaust rack and immediately restore <h2 style=";text-align:left;direction:ltr">6P, 7P Then move the temperature and pressure measuring frame to the furnace room where the original main exhaust frame is located, that is, 2P, and quickly install the thermocouple; at this time, the original main exhaust frame becomes the auxiliary exhaust frame, and the original auxiliary exhaust frame becomes the main exhaust frame; G. Quickly place the sealing baffle taken out in operation B into the furnace chamber where the new auxiliary smoke exhaust rack is located; H. Install the signal line of the new main smoke exhaust rack, readjust the valves of each fire channel in the new main smoke exhaust rack, and control the negative pressure of each fire channel of the temperature and pressure measuring rack to the normal value; I. Stop the blast rack and cooling rack, dismantle the combustion rack and zero-pressure rack that were shut down in step A, then hoist the combustion rack and install it in the furnace chamber 5P at the rear of the preheating section in the direction of the flame. Place the thermocouples and natural gas burners of each fire channel into the corresponding fire channel, connect the natural gas, power, and signal lines, confirm that the negative pressure of the temperature and pressure measuring racks is above -100Pa, and quickly resume combustion on the combustion rack. J. Move the zero pressure rack forward one furnace chamber and install it; K. Lift the blast rack and cooling rack and move them forward one furnace chamber respectively, install them and restore them to work. Example 2

[0014] Using the method of Example 1 for continuous negative pressure furnace shifting effectively reduces the problem of flue temperature drop during the shifting process, reducing the shifting time from 40 minutes to 20 minutes. Operating on a 28-hour combustion cycle, the furnace is shifted 938 times per year, saving 30 cubic meters of natural gas per shift. Based on the current natural gas price of 2.8 yuan, the calculation is: 938 * 30 * 2.8 = 78,792 yuan.

Claims

1. An energy-saving furnace transfer method for anode baking, characterized in that: The following steps are involved: A. Close the combustion rack of the last furnace chamber in the high-temperature sintering section in the direction of flame movement, and keep the combustion racks of the other high-temperature sintering section furnace chambers open normally; B. Quickly disassemble and remove the sealing baffle of the furnace chamber where the main exhaust rack is located; C. Open the auxiliary smoke exhaust rack main valve to the maximum at a uniform speed, then open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, and at the same time close the main smoke exhaust rack main valve to half at a uniform speed. During the operation, keep the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section above -100Pa; D. Further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so that the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section reaches -120Pa±5Pa; close the main valve of the main smoke exhaust rack at a uniform speed until it is completely closed. At the same time, further open the valves of each fire channel of the auxiliary smoke exhaust rack at a uniform speed, so that the negative pressure value of each fire channel on the temperature and pressure measuring rack of the first furnace chamber of the preheating section is maintained at -125Pa±5Pa; E. Remove the signal line of the main smoke exhaust rack, take out the thermocouple of the temperature and pressure measuring rack, and cover the fire channel cover corresponding to the thermocouple; F. Close the combustion racks of the other high-temperature sintering furnace chambers in step A, then hoist the main exhaust rack forward along the flame direction to the adjacent furnace chamber before the auxiliary exhaust rack, quickly close the fire channel cover of the furnace chamber corresponding to the main exhaust rack, reinstall the signal line, and immediately resume the operation of the combustion racks of the other high-temperature sintering furnace chambers; move the temperature and pressure measuring racks and install them to the furnace chamber where the auxiliary exhaust rack was originally located; at this time, the original main exhaust rack becomes the auxiliary exhaust rack, and the original auxiliary exhaust rack becomes the main exhaust rack; G. Quickly install the sealing baffle taken out in operation B to the furnace room where the new auxiliary exhaust rack is located; H. Re-adjust the valves of each fire channel in the new main smoke exhaust rack to control the negative pressure of each fire channel to the normal value; I. Stop the operation of the blast rack and the cooling rack, dismantle the combustion rack and the zero-pressure rack closed in step A, hoist the combustion rack and install it in the furnace chamber at the rear of the flame direction in the preheating section, and quickly resume combustion on the combustion rack; J. Move the zero pressure rack forward one furnace chamber and install it; K. Lift the blast rack and cooling rack and move them forward one furnace chamber respectively, install them and restore them to work.

2. The energy-saving anode baking furnace transfer method according to claim 1, characterized in that: Before carrying out step A, open the agricultural film on the furnace chamber at the rear of the flame in the preheating section and lay the filling coke covering material.

3. The energy-saving anode baking furnace transfer method according to claim 1, wherein: In the step E, the thermocouple of the temperature and pressure measuring frame is taken out while the fire channel cover corresponding to the thermocouple is quickly covered.

4. The energy-saving anode baking furnace transfer method according to claim 1, wherein: In the step I, after the combustion rack is hoisted, the thermocouples and natural gas burners of each fire channel are placed in the corresponding fire channel openings, the natural gas, power supply, and signal lines are connected, and the work of the combustion rack can be started after confirming that the negative pressure of the temperature and pressure measuring rack is above -100 Pa.