A method for shortening the time for stabilizing the carbon potential of a salt bath wire point furnace

Abstract

The application discloses a method for shortening the time for stabilizing carbon potential of a salt bath line point furnace, and belongs to the technical field of metallurgical methods.The method comprises the following steps: S1, before the furnace is started, the front and rear furnace doors of the salt bath furnace are blocked, and six of the eight manholes on the top of the furnace are blocked, and only two manholes are not blocked; S2, after the furnace is started, the temperature is raised to 200-250 DEG C and the temperature is kept for 4-5 hours; S3, the temperature is continuously raised to 400-450 DEG C, and nitrogen is introduced; the temperature is continuously raised to 700-750 DEG C, and carbon source gas is introduced; S4, the temperature is continuously raised to 900-910 DEG C and the temperature is kept for 24-36 hours, and the stable carbon potential is reached.The method can greatly accelerate the time for reaching the stable carbon potential, thereby improving the production efficiency and reducing the cost.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical method technology, specifically relating to a method for shortening the time required to stabilize carbon potential in a salt bath furnace. Background Technology

[0002] The salt bath heating furnace is an atmosphere-controlled furnace, with nitrogen and carbon source gas as protective gases. By adjusting the atmosphere inside the furnace, the oxygen content can be reduced, thus ensuring that the wire surface does not decarburize. During production operation, the furnace door and manhole of the salt bath heating furnace must be completely sealed before starting production, and production can begin after the carbon potential has stabilized. This process is relatively long, taking approximately 4 days (the air inside the furnace is slowly consumed only through heating and combustion, resulting in a long carbon potential stabilization period), which affects the production line running time.

[0003] Furthermore, the carbon source gas is continuously consumed during the ignition and carbon potential stabilization process. Therefore, to save on carbon source costs, it is also necessary to shorten the ignition and carbon potential stabilization time in the salt bath line as quickly as possible. Summary of the Invention

[0004] Technical problem solved: To address the above-mentioned technical problem, the present invention provides a method for shortening the time to stabilize carbon potential in a salt bath furnace, which can greatly accelerate the time to reach a stable carbon potential, thereby improving production efficiency and reducing costs.

[0005] Technical solution: A method for shortening the time for stabilizing carbon potential in a salt bath furnace, comprising the following steps: S1. Before ignition, seal the front and rear doors of the salt bath furnace, and seal 6 of the 8 manholes on its top, leaving only 2 unsealed; S2. After ignition, raise the temperature to 200~250℃ and hold for 4~5 hours; S3. Continue heating to 400~450℃ and introduce nitrogen gas; continue heating to 700~750℃ and introduce carbon source gas; S4. Continue heating to 900~910℃ and hold for 24~36 hours to achieve stable carbon potential.

[0006] Preferably, the sealing material is mineral wool.

[0007] Preferably, the carbon source gas is methanol and natural gas.

[0008] Furthermore, the salt bath furnace is equipped with three methanol inlets, with methanol flow rates of 0.9 L / h, 0.9 L / h, and 0.9 L / h, respectively.

[0009] Furthermore, the salt bath furnace is equipped with two natural gas inlets, with natural gas flow rates of 1.8 m³ / s and 1.8 m³ / s respectively. 3 / h and 1.8m 3 / h.

[0010] Preferably, the salt bath furnace has four nitrogen inlets, with nitrogen flow rates of 22m³ / h and 22m³ / h respectively. 3 / h、48m 3 / h、21m 3 / h and 21m 3 / h.

[0011] Beneficial effects: During the initial ignition of the salt bath furnace, the front and rear furnace doors are tightly sealed with mineral wool. Simultaneously, six of the eight manholes at the top are sealed, leaving two unsealed. After the furnace temperature reaches approximately 200℃ and is held for about four hours, the remaining manholes are sealed. Normal production is then initiated after the sealing is complete. By combining combustion with exhaust through the reserved manholes, the oxygen content inside the furnace is reduced, shortening the time it takes for the carbon potential to stabilize.

[0012] Specifically, the furnace door and its six manholes are sealed. This serves two purposes: firstly, the oxygen content inside the furnace is reduced through combustion; secondly, the air inside the furnace expands under heating conditions and escapes through the two pre-existing manholes. The temperature is set at around 200℃, primarily considering the coefficient of thermal expansion and safety: too high a temperature increases the safety risk; too low a temperature results in insufficient gas expansion and slows down gas escape. Sealing is performed after approximately 4 hours of continuous holding. This ensures that as much oxygen as possible is released from the furnace; excessively long holding times disrupt the process. Experiments show that holding for four hours followed by continuous heating ensures that the carbon potential stabilizes simultaneously when the process temperature is reached. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments. Example 1

[0014] A method for shortening the time required to stabilize carbon potential in a salt bath furnace includes the following steps: S1. Before ignition, mineral wool is used to seal the front and rear doors of the salt bath furnace, and 6 of the 8 manholes on the top are sealed, leaving only 2 unsealed. Sealing the furnace doors and 6 manholes reduces the oxygen content in the furnace through combustion. On the other hand, the air in the furnace expands under heating conditions and will be discharged through the 2 reserved manholes.

[0015] S2. After ignition, the temperature is raised to 200℃ and held for 4 hours. The temperature is set at around 200℃ primarily for consideration of thermal expansion coefficient and safety: too high a temperature increases the safety risk; too low a temperature results in insufficient gas expansion and slower gas discharge. The furnace is sealed after approximately 4 hours of holding to ensure maximum oxygen discharge. Prolonged holding time disrupts the process rhythm. Experiments have shown that holding for four hours followed by further heating ensures stable carbon potential upon reaching the process temperature.

[0016] S3. Continue heating to 400℃ and introduce nitrogen gas; continue heating to 700℃ (mainly for safety reasons) and introduce methanol and natural gas; wherein the methanol ratio is 0.9:0.9:0.9, with a flow rate in L / h; the natural gas ratio is 1.8:1.8, with a flow rate in m³ / h. 3 / h; the nitrogen gas ratio is 22:48:21:21, and the flow rate is measured in m³ / h. 3 / h.

[0017] S4. Continue heating to 900℃ (process temperature) and hold for about 30 hours. At this time, the carbon potential in the furnace will be basically stable at the production value, and normal production can be arranged. The total time is about 2 days.

[0018] This invention reduces the oxygen content in the furnace and shortens the time it takes for the carbon potential in the furnace to stabilize (from about 4 days to about 2 days, a reduction of about half the time) by combining combustion with pre-reserved manhole exhaust.

Claims

1. A method for shortening the time required to stabilize carbon potential in a salt bath furnace, characterized in that, The steps include the following: S1. Before ignition, seal the front and rear doors of the salt bath furnace, and seal 6 of the 8 manholes on its top, leaving only 2 unsealed; S2. After ignition, raise the temperature to 200~250℃ and hold for 4~5 hours; S3. Continue heating to 400~450℃ and introduce nitrogen gas; Continue heating to 700~750℃ and introduce carbon source gas; S4. Continue heating to 900~910℃ and hold for 24~36 hours to achieve stable carbon potential.

2. The method for shortening the time for stabilizing carbon potential in a salt bath furnace according to claim 1, characterized in that, The sealing material used is mineral wool.

3. The method for shortening the time for stabilizing carbon potential in a salt bath furnace according to claim 1, characterized in that, The carbon source gases are methanol and natural gas.

4. The method for shortening the time for stabilizing carbon potential in a salt bath furnace according to claim 3, characterized in that, The salt bath furnace has three methanol inlets with methanol flow rates of 0.9 L / h, 0.9 L / h, and 0.9 L / h, respectively.

5. The method for shortening the time for stabilizing carbon potential in a salt bath furnace according to claim 3, characterized in that, The salt bath furnace has two natural gas inlets, with natural gas flow rates of 1.8 m³ / s and 1.8 m³ / s respectively. 3 / h and 1.8m 3 / h.

6. The method for shortening the time for stabilizing carbon potential in a salt bath furnace according to claim 1, characterized in that, The salt bath furnace has four nitrogen inlets, with nitrogen flow rates of 22 m³ / s and 22 m³ / s respectively. 3 / h、48m 3 / h、21m 3 / h and 21m 3 / h.