CN115323301A - High-precision automatic humidifying system for furnace nose of cold-rolling hot-galvanizing unit - Google Patents

High-precision automatic humidifying system for furnace nose of cold-rolling hot-galvanizing unit Download PDF

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CN115323301A
CN115323301A CN202210854696.9A CN202210854696A CN115323301A CN 115323301 A CN115323301 A CN 115323301A CN 202210854696 A CN202210854696 A CN 202210854696A CN 115323301 A CN115323301 A CN 115323301A
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nitrogen
closed tank
branch
valve
water
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彭起
熊俊伟
王森
甄雅曼
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Wisdri Engineering and Research Incorporation Ltd
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/003—Apparatus
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; Strips

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  • Engineering & Computer Science (AREA)
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  • Organic Chemistry (AREA)
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Abstract

The invention relates to a high-precision automatic humidifying system for a furnace nose of a cold rolling hot galvanizing unit, which comprises a closed tank and a nitrogen access pipeline, wherein water is filled in the closed tank, an electric heating device is arranged in the closed tank, the nitrogen access pipeline is divided into a first branch and a second branch, the first branch is led into the closed tank, and the opening end of the first branch is submerged below the liquid level of the water in the closed tank; after nitrogen is introduced, the nitrogen naturally floats upwards to be in full contact with water in the closed tank, the temperature is consistent with the water temperature and the state is saturated, the nitrogen floating above the liquid level is saturated wet nitrogen, and the saturated wet nitrogen is discharged along the outlet of the closed tank; the nitrogen in the second branch is dry nitrogen, the dry nitrogen is mixed with saturated wet nitrogen at the outlet of the closed tank, and the outlet of the closed tank is provided with a mixed wet nitrogen pipeline. The invention can realize high-precision automatic humidification of the furnace nose of the cold rolling hot galvanizing unit and realize stable control of nitrogen humidity, thereby effectively reducing the zinc ash defect of strip steel and improving the surface quality of products.

Description

High-precision automatic humidifying system for furnace nose of cold-rolling hot-galvanizing unit
Technical Field
The invention relates to the field of cold rolling in the metallurgical industry, in particular to a high-precision automatic humidifying system for a furnace nose of a cold rolling hot galvanizing unit.
Background
A hot-dip galvanized sheet produced by a cold-rolling hot-dip galvanizing unit in the metallurgical industry has the main product quality defect of a coating zinc slag defect. The reason for the defect of the generated coating zinc dross is that the special coating process of hot galvanizing comprises the following steps: the strip steel enters a zinc pot filled with zinc liquid through a sealed furnace nose area, and the strip steel after being discharged out of the zinc pot is coated by a series of measures such as thickness control of a zinc layer of an air knife, cooling and the like. The temperature of the zinc liquid in the zinc pot is higher than the melting point of zinc, part of zinc steam can be gasified and enters the furnace nose, and the zinc steam can be rapidly cooled in the furnace nose to form zinc slag because the temperature in the furnace nose is far lower than the temperature of the zinc pot. The zinc dross can fall on the surface of the cold-rolled steel plate, so that the surface of the galvanized plate after coating is uneven, and the zinc dross defect is formed.
The zinc liquid purification system is used for solving the problem of zinc slag defect, and mainly comprises: a furnace nose humidifying device and a furnace nose deslagging device. The humidifying device is used for introducing nitrogen with certain humidity into the interface between the furnace nose and the zinc pot, so that zinc vapor evaporated from the zinc pot reacts with wet nitrogen before entering the furnace nose to generate ZnO which falls on the surface of zinc liquid in the zinc pot to form a film, and further evaporation of the zinc vapor is prevented from entering the furnace nose to form zinc ash.
Because the speed, size, temperature and other unit operation parameters of a steel plate entering a zinc pot fluctuate, a film formed on the surface of zinc liquid in the zinc pot is easy to break, and in order to keep the complete shape of the film, the humidity (dew point temperature) and flow rate of wet nitrogen gas must be quickly adjusted according to different unit operation parameters, and the stability of the humidity (dew point temperature) and the flow rate is maintained as much as possible after the adjustment.
The zinc dross accumulated in the furnace nose is difficult to remove manually, and the existence of the zinc dross not only affects the product quality, but also affects the productivity of a unit. With the development of high-end automobile plates, the requirements of the market on the surface quality are stricter and stricter, and more automobile plate production enterprises begin to increase a zinc liquid purification system for keeping the cleanness of zinc liquid in the nose area of a furnace and improving the product grade.
Disclosure of Invention
The invention aims to solve the technical problem of providing a high-precision automatic humidifying system for a furnace nose of a cold rolling hot galvanizing unit, which can effectively reduce the zinc ash defect of strip steel and improve the surface quality of products.
The technical scheme adopted by the invention for solving the technical problems is as follows: the high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit comprises a closed tank and a nitrogen gas access pipeline, wherein water is filled in the closed tank, an electric heating device is arranged in the closed tank, the nitrogen gas access pipeline is divided into a first branch and a second branch, the first branch is communicated into the closed tank, and the opening end of the first branch is submerged below the liquid level of the water in the closed tank; after the nitrogen is introduced, naturally floating to fully contact with water in the closed tank, enabling the nitrogen to reach the temperature consistent with the water temperature and be saturated, taking the nitrogen floating above the liquid level as saturated wet nitrogen, and discharging the saturated wet nitrogen along an outlet of the closed tank; the nitrogen in the second branch is dry nitrogen, the dry nitrogen is mixed with saturated wet nitrogen at the outlet of the closed tank, and a mixed wet nitrogen pipeline is arranged at the outlet of the closed tank.
According to the scheme, the first branch is provided with the first pressure reducing valve, and the second branch is provided with the second pressure reducing valve.
According to the scheme, a first flow detection device, a first automatic regulating valve and a first airflow speed control valve are arranged on the first branch; and a second flow detection device, a second automatic regulating valve and a second air flow speed control valve are arranged on the second branch.
According to the scheme, a mixed wet nitrogen moisture content detection device is arranged on the mixed wet nitrogen pipeline.
According to the scheme, the electric heating device is connected with the silicon controlled temperature control device.
According to the scheme, the water temperature detection device and the liquid level detection device are arranged in the closed tank.
According to the scheme, the nitrogen gas access pipeline is provided with the first automatic cut-off valve.
According to the above scheme, airtight jar still is connected with the desalination water pipeline, be equipped with the second automatic cutout valve, check valve and the third automatic cutout valve that connect gradually on the desalination water pipeline.
The high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit has the following beneficial effects:
the nitrogen in the high-precision automatic humidification system for the furnace nose of the cold rolling hot galvanizing unit is divided into two branches, one branch is introduced into a closed container, and the opening end of the branch is submerged below the liquid level of water in the container; after the nitrogen is introduced, the nitrogen naturally floats upwards to fully contact with the water in the container, and the temperature reaches the same temperature as the water and is saturated. The nitrogen floating above the liquid level is called saturated wet nitrogen, which will be discharged along the outlet of the vessel. The nitrogen in the other branch is called dry nitrogen, the dry nitrogen and the saturated wet nitrogen are mixed after the outlet of the closed container, and the moisture content of the mixed nitrogen meets the requirement. The invention can realize high-precision automatic humidification of the furnace nose of the cold rolling hot galvanizing unit and realize stable control of nitrogen humidity, thereby effectively reducing the zinc ash defect of strip steel and improving the surface quality of products.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a schematic diagram of a high-precision automatic humidifying system for a furnace nose of a cold-rolling hot-galvanizing unit;
FIG.2 is a graph of saturated nitrogen moisture content at different temperatures;
fig. 3 is a graph of valve characteristics.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in figure 1, the high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit comprises a closed tank 18 and a nitrogen gas access pipeline 1, wherein water is filled in the closed tank 18, an electric heating device 19 is arranged in the closed tank, the nitrogen gas access pipeline 1 is divided into a first branch and a second branch, the first branch is communicated with the closed tank 18, and the opening end of the first branch is submerged below the liquid level of the water in the closed tank 18. After the nitrogen is introduced, the nitrogen naturally floats upwards to be fully contacted with the water in the closed tank 18, the temperature is consistent with the water temperature and the state is saturated, the nitrogen floating above the liquid level is saturated wet nitrogen, and the saturated wet nitrogen is discharged along an outlet 15 of the closed tank 18. The nitrogen in the second branch is dry nitrogen, the dry nitrogen is mixed with saturated wet nitrogen at the outlet of the closed tank 18, and a mixed wet nitrogen pipeline 16 is arranged at the outlet 15 of the closed tank 18.
The first branch is provided with a first pressure reducing valve 9, and the second branch is provided with a second pressure reducing valve 10. The first branch is provided with a first flow detection device 3, a first automatic regulating valve 4 and a first airflow speed control valve 5. And a second branch is provided with a second flow detection device 6, a second automatic regulating valve 7 and a second airflow speed control valve 8.
And a mixed wet nitrogen moisture content detection device 17 is arranged on the mixed wet nitrogen pipeline 16. The electric heating device 19 is connected with the silicon controlled temperature control device 23. A water temperature detector 20 and a liquid level detector 21 are provided in the closed tank 18. The nitrogen gas access pipeline 1 is provided with a first automatic cut-off valve 2. The closed tank 18 is also connected to a desalination water line 14, and the desalination water line 14 is provided with a second automatic shut-off valve 11, a check valve 12, and a third automatic shut-off valve 13, which are connected in this order.
The high-precision automatic humidifying system for the furnace nose of the cold rolling and hot galvanizing unit further comprises a PLC control system 26, wherein the PLC control system is connected with a first pressure reducing valve 9, a second pressure reducing valve 10, a first flow detection device 3, a first automatic regulating valve 4, a first air flow speed control valve 5, a second flow detection device 6, a second automatic regulating valve 7, a second air flow speed control valve 8, a mixed wet nitrogen moisture content detection device 17, an electric heating device 19, a silicon controlled temperature control device 23, a water temperature detection device 20, a liquid level detection device 21, a first automatic cut-off valve 2, a second automatic cut-off valve 11, a check valve 12 and a third automatic cut-off valve 13, so that automatic control is realized.
The working principle of the invention is as follows:
the nitrogen from the plant itself has a low moisture content and can be considered dry nitrogen, requiring the nitrogen to be humidified. A closed container is arranged, water is contained in the container, and a heater is arranged to heat the water to a specified temperature. The nitrogen is divided into two branches, one branch is introduced into the closed container, and the opening end of the branch is submerged below the liquid level of the water in the container; after nitrogen is introduced, the nitrogen naturally floats upwards to fully contact with water in the container, and the temperature is consistent with the water temperature and is saturated. The nitrogen floating above the liquid level is called saturated wet nitrogen, and the saturated wet nitrogen is discharged along the outlet of the container. The nitrogen in the other branch is called dry nitrogen, the dry nitrogen and the saturated wet nitrogen are mixed after the outlet of the closed container, and the moisture content of the mixed nitrogen meets the requirement.
According to the production process requirement, the flow of wet nitrogen introduced into the furnace nose of the humidifying device system device is required to be controlled at a certain value (V), and the fluctuation of the wet nitrogen is allowed to be 10 percent; the moisture content of the wet nitrogen gas needs to be controlled at a certain value (d), which requires the more stable the better. The target value of the production process requirements may vary according to variations in production conditions.
The invention can stably control the nitrogen humidity, and several important factors influencing the mixed nitrogen humidity are as follows:
1. water temperature of the closed container: the water temperature determines the moisture content of the nitrogen gas which is introduced into the closed container at a unit flow rate and reaches a saturated state after the nitrogen gas is fully contacted with the water, and the corresponding curve of the water temperature (within the range of 10-70 ℃) and the moisture content (g/kg) of the saturated wet nitrogen gas obtained after the nitrogen gas at the unit flow rate is humidified is obtained through research and calculation, as shown in figure 2, the influence of the temperature change on the moisture content is large.
2. The flow rate of nitrogen introduced into the closed container determines the total moisture content of the saturated wet nitrogen according to the flow rate;
3. the flow rate of the dry nitrogen gas is that the dry nitrogen gas with a certain flow rate is mixed with the saturated wet nitrogen gas, and the moisture content of the mixed gas is reduced to a target value.
Firstly, the calculation formula of the moisture content of saturated wet nitrogen at a certain temperature is deduced as follows:
Figure BDA0003749913470000051
wherein:
d is the moisture content of saturated wet nitrogen gas, g/kg;
n is the ratio of the amount of the water vapor substance to the amount of the dry nitrogen substance, and the value is 0.643;
p is the total static pressure of the saturated wet nitrogen, namely the atmospheric pressure plus the gauge pressure of the saturated wet nitrogen pipeline;
P s to saturate the water vapor partial pressure of the wet nitrogen, according to the Anthon equation:
Figure BDA0003749913470000052
t is the saturated wet nitrogen temperature, i.e. the closed container water temperature.
The target value V of the humidifying flow rate set by the process is continued t And a target moisture content value d t Deriving a dry nitrogen and wet nitrogen flow formula:
the mass of the dry nitrogen in unit time is set as M d At a flow rate of V d (ii) a The dry nitrogen mass per unit time of saturated wet nitrogen is M w At a flow rate of V w ；V t Is equal to V w +V d )；
M w ×d＝(M w +M d )×d t →
V w ×d＝(V w +V d )×d t →
Figure BDA0003749913470000053
V d ＝V t －V w Equation 3
According to the formula 2 and the formula 3, after the target value of the production process is set, the automatic control valves of the two branches are accurately controlled to the corresponding opening degrees; in order to ensure the control accuracy of the automatic control valve, it is necessary to keep the valve opening within a certain range, which depends on the characteristics of the valve itself. The system device is characterized in that a pressure reducing valve is added at the inlets of the two branches and used for reducing the pressure of nitrogen at the inlet of the automatic control valve at proper time, so that the opening degree of the valve can work in a high-precision control range; meanwhile, a bypass is added to a branch of the automatic control valve, and a proper air flow speed control valve is selected through calculation and used as flow compensation of the automatic control valve, so that the valve opening degree can be ensured to be within a high-precision control range.
And a moisture content detection device is arranged on the mixed wet nitrogen pipeline, and the detection value is used for adjusting the flow of dry nitrogen to ensure that the final air supply moisture content is stabilized at a target value.
In the aspect of water temperature control, an electric heating device and a temperature sensor are arranged in the closed tank, and the current voltage of the electric heater is adjusted by an external silicon controlled temperature control device according to the comparison between the actual temperature detected by the temperature sensor and the set temperature, so that the temperature fluctuation is controlled within 1 ℃.
The invention also provides a liquid level maintaining system of the closed tank, wherein the closed tank is provided with a liquid level sensor, and the liquid level value in the monitoring tank is in a certain range. Setting at least 4 interlocking trigger values HH \ H \ L \ LL in the monitoring process, and starting to alarm and cut off nitrogen supply when the liquid level reaches HH or is lower than LL; when the liquid level monitoring value is lower than L, the desalted water replenishing cut-off valve is opened, and when the liquid level monitoring value reaches L, the desalted water replenishing cut-off valve is closed. The liquid level maintaining system fully considers the safety of the system, a double-cut-off valve and a check valve are arranged on a desalted water supply pipeline, and the check valve is arranged between the double-cut-off valves, so that the maintenance is convenient; the arrangement ensures that when one cut-off valve goes wrong, the pipeline can be cut off in time, and accidents caused by the reverse flow of nitrogen through the desalination water pipeline in an accident state are prevented.
The high-precision automatic humidification system for the furnace nose of the cold-rolling hot-galvanizing unit is implemented by three relatively independent processes:
1. a humidifying process:
after the system is started, a first automatic cut-off valve 2 on the nitrogen access pipeline 1 is opened when the conditions are met; nitrogen is accessed into the system device through a nitrogen access pipeline 1; opening degree and flow rate curves and formulas of the first automatic regulating valve 4 and the second automatic regulating valve 7 are introduced into the PLC control system 22 in advance.
For example, a valve characteristic is shown in fig. 3.
The flow characteristic values corresponding to the opening degrees are dispersed according to the characteristic curve, and the corresponding table is shown as table 1:
table 1 flow characteristic value dispersion table corresponding to opening degree
Figure BDA0003749913470000071
Setting dry and wet nitrogen flow calculation formulas (formula 2 and formula 3) in the PLC control system 22 in advance; inputting a humidification flow Vt and a moisture content dt target value in a PLC control system 22 according to a production process; the PLC control system 22 calculates the dry nitrogen and saturated wet nitrogen flow Vd and Vw according to the input value and the current water temperature ta of the closed tank 18; the PLC control system 22 calculates the opening degrees of the first automatic regulating valve 4 and the second automatic regulating valve 7 based on the Vd and Vw calculation results and the correspondence table of the valve opening degrees and the flow rates, and quickly opens the two valves to the changed opening degrees, and the flow rates not in the table are calculated according to an interpolation method.
Saturated wet nitrogen enters the closed tank 18 through the first automatic regulating valve 4 for humidification, and is discharged through the closed tank outlet 15. The dry nitrogen passes through the second automatic regulating valve 7, is mixed with the saturated wet nitrogen, and is led to the furnace nose through a mixed wet nitrogen pipeline 16. The wet nitrogen pipeline 16 is provided with a mixed wet nitrogen moisture content detection device 17, and the detected actual moisture content value da is compared with the moisture content target value dt; and the PLC control system 22 adjusts the opening degree of the second automatic regulating valve 7 according to the difference value of da and dt.
An operator manually adjusts the second reducing valve 10 or the second gas flow rate control valve 8 according to the opening degree of the second automatic regulating valve 7, if the opening degree of the second automatic regulating valve 7 is smaller than the lower limit of the opening degree of the high-precision control range, the operator adjusts the second reducing valve 10 to reduce the pressure of the branch nitrogen until the opening degree of the second automatic regulating valve 7 is automatically adjusted to be within the high-precision control range; if the opening degree of the second automatic regulating valve 7 is larger than the upper limit of the opening degree of the high-precision control range, the second airflow rate control valve 8 is adjusted, and the valve opening degree is slowly increased until the opening degree of the second automatic regulating valve 7 is automatically adjusted to be within the high-precision control range.
An operator manually adjusts the first pressure reducing valve 9 or the saturated first airflow speed control valve 5 according to the opening degree of the saturated first automatic regulating valve 4, if the opening degree of the saturated first automatic regulating valve 4 is smaller than the lower limit of the opening degree of the high-precision control range, the first pressure reducing valve 9 is adjusted, the pressure of branch nitrogen is reduced, and the opening degree of the saturated first automatic regulating valve 4 is automatically adjusted to be within the high-precision control range; if the opening of the saturated first automatic regulating valve 4 is larger than the upper limit of the opening of the high-precision control range, the saturated first airflow speed control valve 5 is adjusted, and the opening of the saturated first automatic regulating valve 4 is slowly increased until the opening of the saturated first automatic regulating valve is automatically adjusted to be within the high-precision control range.
After the above adjustment, the operator checks whether the mixed wet nitrogen flow rate (Vda + Vwa) is within the allowable fluctuation range (Vt ± 5%) of the production process, based on the dry nitrogen actual flow rate Vda detected by the second flow rate detection device 6 and the saturated wet nitrogen actual flow rate Vwa detected by the first flow rate detection device 3. If the adjusted mixed wet nitrogen flow rate (Vda + Vwa) is higher than (Vt + 5%) because the saturated wet nitrogen flow rate is too large, the operator should reduce the opening degree of the first air flow rate control valve 5 and adjust the opening degree of the first pressure reducing valve 9 to ensure that the opening degree of the saturated first self-regulating valve 4 is maintained within the high-precision control range.
If the adjusted mixed wet nitrogen flow rate (Vda + Vwa) is lower than (Vt-5%) because the saturated wet nitrogen flow rate is too low, the operator should increase the opening degree of the first air flow rate control valve 5 and adjust the opening degree of the first pressure reducing valve 9 to ensure that the opening degree of the saturated first self-regulating valve 4 is maintained within the high-precision control range. If the adjusted flow rate of the mixed wet nitrogen cannot meet the requirement, the water temperature of the closed tank 18 is lowered or raised, and the adjustment is calculated again.
The flow of dry and wet nitrogen is calculated through a dry and wet nitrogen flow calculation formula, so that the opening of the automatic regulating valve is controlled, and the opening of the automatic regulating valve is kept in a high-precision control range through the reducing valve and the airflow speed control valve, which is the core for maintaining the high-precision control of the system on the moisture content.
2. The temperature control process of the closed tank comprises the following steps:
according to the production process, a water temperature target temperature tt of the closed tank 18 is set in the silicon controlled temperature control device 23. After the system is started, when the liquid level of the closed tank 18 is higher than L, the electric heating device 19 is automatically started and heats the water in the closed tank. The closed tank water temperature detection device 20 detects the actual water temperature ta, the silicon controlled temperature control device 23 controls the voltage of the electric heating device 19 according to the difference value between the actual water temperature ta and the target water temperature tt, and the water temperature is controlled to be stable after the water temperature reaches the target water temperature tt.
3. The liquid level control process of the closed tank comprises the following steps:
according to the production process, a liquid level interlocking trigger value of the closed tank 18 is set in a PLC control system 22 and is HH \ H \ L \ LL from high to low. After the system is started, the second automatic cutoff valve 11 and the third automatic cutoff valve 13 are automatically opened at the same time. Desalted water enters the closed tank 18 through the desalted water pipeline 14, and a closed tank liquid level detection device (FIG. 21) continuously detects the liquid level. When the liquid level reaches H, the PLC control system 22 controls the second automatic cut-off valve 11 and the third automatic cut-off valve 13 to be automatically closed at the same time, and the desalted water is stopped from entering; when the liquid level is reduced to L, the PLC control system 22 controls the second automatic cut-off valve 11 and the third automatic cut-off valve 13 to be automatically opened at the same time, and the desalted water is started to enter water. When the liquid level is higher than HH or lower than LL, the PLC control system 22 controls the second automatic cut-off valve 11 and the third automatic cut-off valve 13 to be automatically closed at the same time, and at the moment, the system is in an accident state and needs an operator to check. The arrangement of the double-cut-off valve can ensure that the system is safer.
While the present invention has been described with reference to the particular illustrative embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications, equivalent arrangements, and equivalents thereof, which may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

1. The high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit is characterized by comprising a closed tank and a nitrogen access pipeline, wherein water is filled in the closed tank, the closed tank is provided with an electric heating device, the nitrogen access pipeline is divided into a first branch and a second branch, the first branch is introduced into the closed tank, and the opening end of the first branch is submerged below the liquid level of the water in the closed tank; after nitrogen is introduced, the nitrogen naturally floats upwards to be in full contact with water in the closed tank, the temperature is consistent with the water temperature and the state is saturated, the nitrogen floating above the liquid level is saturated wet nitrogen, and the saturated wet nitrogen is discharged along the outlet of the closed tank; the nitrogen in the second branch is dry nitrogen, the dry nitrogen is mixed with saturated wet nitrogen at the outlet of the closed tank, and the outlet of the closed tank is provided with a mixed wet nitrogen pipeline.
2. The high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit according to claim 1, wherein a first pressure reducing valve is arranged on the first branch, and a second pressure reducing valve is arranged on the second branch.
3. The furnace nose high-precision automatic humidifying system of the cold rolling hot galvanizing unit according to claim 1, wherein a first flow detection device, a first automatic regulating valve and a first airflow speed control valve are arranged on the first branch; and a second flow detection device, a second automatic regulating valve and a second airflow speed control valve are arranged on the second branch.
4. The high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit according to claim 1, wherein a mixed wet nitrogen moisture content detection device is arranged on the mixed wet nitrogen pipeline.
5. The high-precision automatic humidifying system for the furnace nose of the cold rolling hot galvanizing unit according to claim 1, wherein the electric heating device is connected with a silicon controlled temperature control device.
6. The high-precision automatic humidifying system for the furnace nose of the cold rolling and hot galvanizing unit according to claim 1, wherein a water temperature detection device and a liquid level detection device are arranged in the closed tank.
7. The high-precision automatic humidifying system for the furnace nose of the cold-rolling hot-galvanizing machine set according to claim 1, wherein a first automatic cut-off valve is arranged on the nitrogen gas access pipeline.
8. The high-precision automatic humidification system for the furnace nose of the cold rolling hot galvanizing unit according to claim 1, wherein the closed tank is further connected with a desalination water pipeline, and a second automatic cut-off valve, a check valve and a third automatic cut-off valve which are sequentially connected are arranged on the desalination water pipeline.
CN202210854696.9A 2022-07-18 2022-07-18 High-precision automatic humidifying system for furnace nose of cold-rolling hot-galvanizing unit Pending CN115323301A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN209260142U (en) * 2018-12-18 2019-08-16 北京京诚凤凰工业炉工程技术有限公司 A kind of hot galvanizing annealing furnace nose humidifier
CN215328320U (en) * 2021-03-10 2021-12-28 唐山钢铁集团有限责任公司 Furnace nose nitrogen gas jet air supply device for cold rolling galvanization

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN209260142U (en) * 2018-12-18 2019-08-16 北京京诚凤凰工业炉工程技术有限公司 A kind of hot galvanizing annealing furnace nose humidifier
CN215328320U (en) * 2021-03-10 2021-12-28 唐山钢铁集团有限责任公司 Furnace nose nitrogen gas jet air supply device for cold rolling galvanization

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