A baking furnace method for solving the problem of gushing and splashing at the cast iron notch
By scientifically setting the oven time, temperature and temperature increase speed algorithm, combined with casing design and thermocouple monitoring, the problem of iron mouth splashing when the blast furnace is opened is solved, and the water vapor in the iron mouth area is completely dried, ensuring the safety of blast furnace opening.
Patent Information
- Application Number
- CN202210402489.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-04-18
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2042-04-18
AI Technical Summary
Iron mouth splash often occurs after the blast furnace is opened, mainly because the castable water vapor in the iron mouth area cannot be effectively dried during the oven, resulting in water vapor splashing during the iron discharge process, affecting safe production.
A specific oven time, temperature and heating speed algorithm is used, combined with the design of the upper and lower sleeves, and the iron mouth hole channel is baked and dried through the sleeve using high-temperature hot air. The oven status is monitored using internal and external thermocouples, and a reasonable insulation time period is set to ensure that the water vapor in the iron mouth is completely dried during the oven.
It effectively solves the problem of iron mouth splashing, ensures the safety of the blast furnace opening process, avoids water vapor splashing, and ensures normal production.
Smart Images
Figure CN114756802B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of blast furnace drying, and particularly relates to a drying method for solving the splash of the cast iron notch. Background Art
[0002] At present, the phenomenon of iron notch splash often occurs after the blast furnace is started, which brings a lot of troubles to normal safe production. The iron notch splash in the early stage of starting the furnace is mainly because the water vapor in the castable in the iron notch area is not dried during the drying process. During the tapping process, the water vapor enters the iron notch channel, and the volume increases rapidly, thus causing splash. Conventional drying methods are difficult to dry the water vapor in the iron notch area. In order to solve the baking problem in the iron notch area, a drying method for solving the splash of the cast iron notch is invented herein. Summary of the Invention
[0003] The purpose of the present invention is to provide a drying method for solving the splash of the cast iron notch, so that the water vapor in the iron notch area is dried during the drying process and no splash will occur.
[0004] The adopted technical solution is as follows:
[0005] A drying method for solving the splash of the cast iron notch, characterized by including the following steps:
[0006] Algorithm for drying time:
[0007] t = 40l + 48, where t is the drying time in hours and l is the thickness of the iron notch castable in meters.
[0008] Algorithm for drying temperature:
[0009] T = 2222AB + 450, where T is the drying temperature in °C, A is the water content of the silica sol binder in %, and B is the addition amount of the silica sol binder in the castable in %.
[0010] The iron notch drying device and equipment used include: an upper sleeve, a lower sleeve, an internal thermocouple, and an external thermocouple.
[0011] The air inlet of the lower sleeve is located inside the furnace. The air outlet of the upper sleeve is located outside the furnace.
[0012] A valve is installed at the end of the air outlet of the upper sleeve.
[0013] The upper sleeve and the lower sleeve communicate with both ends of the iron notch channel in the castable layer.
[0014] Algorithm for the heating rate before reaching the drying temperature:
[0015] s = 25 - 5L / 7, where s is the heating rate in °C / h and L is the diameter of the hearth in m.
[0016] Set the heat preservation time period as needed when heating up.
[0017] Its advantages are as follows:
[0018] Using this method can solve the problem of tuyere spattering and eliminate the previous trouble in normal safe production. The water vapor in the tuyere area is dried during the oven drying process and will not cause spattering. Description of the Drawings
[0019] Figure 1 It is a schematic diagram of the oven drying device for the tuyere area.
[0020] Figure 2 It is an oven drying curve in one case.
[0021] Upper casing 1, valve 2, tuyere frame 3, internal thermocouple 4, lower casing 5, air inlet 6, external thermocouple 7, air inlet hole 8, castable layer 9. Detailed Implementation Manner
[0022] An oven drying method for solving the spattering of cast tuyere, and the equipment of the tuyere oven drying device used includes: upper casing 1, lower casing 5, internal thermocouple 4 and external thermocouple 7.
[0023] The upper casing 1 and the lower casing 5 are cast together with the castable layer 9 during casting.
[0024] The air inlet 6 of the lower casing 5 is located inside the furnace.
[0025] The air outlet of the upper casing 1 is located outside the furnace.
[0026] A valve 2 (manual) is installed at the end of the air outlet of the upper casing 1, which remains open during oven drying to facilitate the discharge of high-temperature gas and is closed during the pressure test for air leakage in the blast furnace.
[0027] The upper casing 1 and the lower casing 5 are connected to both ends of the tuyere hole passage in the castable layer 9.
[0028] The external thermocouple 7 is installed inside the furnace body outside the air inlet 6, and the internal thermocouple 4 is installed in the middle part of the tuyere hole passage. The compensation wire of the internal thermocouple 4 is led out from the upper casing 1. The oven drying temperature is based on the displayed value of the external thermocouple 7, and the internal thermocouple 4 is used as a parameter to measure the baking state of the tuyere hole passage.
[0029] Furthermore, the air inlet 6 is an outward-expanded horn shape.
[0030] Furthermore, a plurality of air inlet holes 8 are provided on the outer side of the lower casing 5.
[0031] The function of the air inlet holes 8 is to increase the air inlet area. When the blast furnace is put into production, the furnace is filled with ore and coke, and sometimes the air inlet 6 will be partially blocked.
[0032] Algorithm for the baking time:
[0033] The length of the baking time is directly related to the thickness of the taphole casting in the tuyere area (taphole depth), and it requires at least 48 hours. The thicker the taphole casting thickness, the longer the baking time required. The relationship between the two is t = 40*(l - 1.5) + 48, where t is the baking time in hours, l is the taphole casting thickness in meters, and * is the multiplication sign.
[0034] Algorithm for the baking temperature:
[0035] The baking temperature is also an important parameter in the baking operation and is related to the water content in the castable. The water in the castable comes from the silica sol binder. The castable includes dry powder and silica sol binder. The silica sol binder includes silica sol and water.
[0036] The water content of the silica sol binder is generally 60 - 70% (by weight), and the addition amount of the silica sol binder in the castable is generally 6.5 - 8.5% (by weight). The more the water content, the higher the baking temperature required. Because the water in such materials is all physically free water and does not require a specific temperature range like traditional refractory materials. The relationship algorithm between the two is: T = 2222*A*B + 450, where T is the baking temperature in °C, A is the water content of the silica sol binder in % (by weight), and B is the addition amount of the silica sol binder in the castable in % (by weight).
[0037] This baking temperature is the maximum temperature for baking. The previous temperature segments are for step - by - step heating to avoid the castable bursting due to the temperature reaching the set value all at once.
[0038] Adopt the following algorithm for the heating rate:
[0039] The heating rate is related to the diameter of the blast furnace hearth. Because all materials have the property of thermal expansion and contraction, for a blast furnace with a larger hearth diameter, the expansion amount is larger and the heating rate should be slower. The relationship between the two is: s = 25 - 5*L / 7, where s is the heating rate in °C / hour and L is the hearth diameter in m. In order to alleviate the rapid release rate of moisture during the heating process and reduce the generation of cracks, heat preservation time periods are set at 125°C, 250°C, and 350°C.
[0040] Before the start of baking, according to the specific situation of the blast furnace, determine all the control index parameters for baking and determine the baking curve. See Figure 2 For a specific situation. The horizontal axis is time (hours), and the vertical axis is temperature in °C
[0041] t = 40*(l - 1.5) + 48 = 40*(3.3 - 1.5) + 48 = 120 hours.
[0042] T = 2222 * A * B + 450 = 2222 * 60% * 7.5% + 450 = 550 °C.
[0043] After the tuyere baking furnace device is installed in place, the furnace is baked according to the above curve, and the effect of solving tuyere splashing can be achieved.
[0044] The outer side of the upper sleeve 1 passes through the tuyere frame 3 fixed outside the furnace body.
[0045] By scientifically setting the algorithms for the baking time and the thickness of the tuyere casting, the baking temperature and the water content of the castable, and the baking heating rate and the hearth diameter, the best baking effect is achieved, and the problem of tuyere splashing in the opening stage of the castable blast furnace tuyere can be solved.
[0046] High-temperature hot air is blown into the furnace. The hot air enters the upper sleeve 1 from the lower sleeve 5 through the tuyere passage and is blown out of the furnace, baking the tuyere passage dry.
Claims
1. A baking furnace method for solving the splash of the casting iron notch, characterized in that It includes the following steps: Algorithm for baking furnace time: t = 40*(l - 1.5) + 48, where t is the baking furnace time in hours and l is the thickness of the taphole casting in meters; Algorithm for baking furnace temperature: T = 2222*A*B + 450, where T is the baking furnace temperature in °C, A is the water content of the silica sol binder in % (by weight), and B is the addition amount of the silica sol binder in the casting material in % (by weight); The taphole baking furnace device and equipment used include: upper casing (1), lower casing (5), internal thermocouple (4), and external thermocouple (7); The air inlet (6) of the lower casing (5) is located inside the furnace; the air outlet of the upper casing (1) is located outside the furnace; A valve (2) is installed at the end of the air outlet of the upper casing (1); The upper casing (1) and the lower casing (5) are connected to both ends of the taphole passage in the casting material layer (9).
2. The oven drying method for solving the splash of the cast iron notch according to claim 1, characterized in that It includes the following steps: Algorithm for the heating rate before reaching the baking furnace temperature: s = 25 - 5*L / 7, where s is the heating rate in °C / hour and L is the furnace hearth diameter in m.
3. A baking furnace method for solving the splash of the casting iron notch according to claim 2, characterized in that It includes the following steps: Set heat preservation time periods at 125°C, 250°C, and 350°C during heating.
4. A baking furnace method for solving the splash of the cast iron notch according to claim 1, characterized in that It includes the following steps: The external thermocouple (7) is installed outside the air inlet (6), and the internal thermocouple (4) is installed inside the taphole passage.
5. A baking furnace method for solving the splash of the casting-type iron notch according to claim 1, characterized in that It includes the following steps: The air inlet (6) is in the shape of an outward-expanded horn.
6. The oven drying method for solving the gushing of the cast iron notch according to claim 1, characterized in that It includes the following steps: Furthermore, a plurality of air inlets (8) are added outside the lower casing (5).