Method for cleaning cold-rolled strip and cleaning unit

Abstract

The application provides a cold-rolled strip cleaning method, which feeds back and adjusts the electrolytic cleaning tank current data of a cleaning section according to the surface roughness of the strip entering the cleaning section and the surface cleanliness of the strip leading out of the cleaning section, and the greater the surface roughness value of the strip at the inlet side of the cleaning section, the higher the surface cleanliness value of the strip at the outlet side, and the higher the electrolytic cleaning tank current value; and the application also provides a cleaning unit, which comprises a cleaning section, a roughness detector and a cleanliness detector, feeds back and adjusts the electrolytic cleaning tank current data of the cleaning section according to the surface roughness of the strip entering the cleaning section and the surface cleanliness of the strip leading out of the cleaning section. In the application, the roughness of the strip before entering the cleaning section and the cleanliness of the strip after leading out of the cleaning section are obtained, the current value of the electrolytic cleaning tank can be adjusted according to the cleanliness and the roughness, and then the power consumption can be reduced under the premise of ensuring the cleaning effect of the strip.

Description

Technical Field

[0001] This invention relates to cold rolling, and more particularly to a method for cleaning cold-rolled strip steel and a cleaning unit. Background Technology

[0002] During cold rolling of strip steel, emulsions are typically used for cooling and lubrication, and the rolling process generates a large amount of iron powder. Therefore, the surface of the rolled strip steel is usually covered with a significant amount of rolling oil and dust, with total contaminants reaching 300-600 mg / (m³). 2 Therefore, before post-processing, cold-rolled strip steel needs to be degreased and cleaned to remove dirt from the surface of the strip steel and prevent adverse effects on post-processing.

[0003] The cleaning of cold-rolled strip steel generally uses an alkaline solution with a certain concentration as the cleaning medium, employing a combination of physical, chemical, and electrochemical methods. This is followed by brushing and spraying with a large amount of fresh water. During this process, electrochemical cleaning consumes electricity. Excessive current increases production costs, while insufficient current can lead to poor surface cleanliness. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a method and cleaning unit for cleaning cold-rolled strip steel to ensure the pickling effect of the strip steel.

[0005] This invention is implemented as follows:

[0006] This invention provides a method for cleaning cold-rolled strip steel. The current data of the electrolytic cleaning tank in the cleaning section is adjusted based on the surface roughness of the strip steel entering the cleaning section and the surface cleanliness of the strip steel exiting the cleaning section. The larger the surface roughness value of the strip steel at the inlet side of the cleaning section and the higher the surface cleanliness value of the strip steel at the outlet side, the higher the current value of the electrolytic cleaning tank.

[0007] Furthermore, the current value of the electrolytic cleaning tank is:

[0008] I = I min +[(RR min ) / (R max -R min )+(CC min ) / (C max -C min )+(VV min ) / (V max -V min )]×

[0009] (I max -I min ) / 3;

[0010] Where: I—current value of the electrolytic cleaning tank; I min —Minimum current value; I max —Maximum current value; R—Measured roughness value; R min —Minimum roughness value; R max —Maximum roughness value; C—Measured cleanliness value; C min —Minimum cleanliness value; C max —Maximum cleanliness value; V—Actual running speed of the strip; V min —Minimum strip running speed; V max —Maximum strip running speed.

[0011] Furthermore, the roughness of the upper and lower surfaces of the strip is tested, and the higher roughness value is taken as the measured roughness value of the strip; the cleanliness of the upper and lower surfaces of the strip is tested, and the higher cleanliness value is taken as the measured cleanliness value of the strip.

[0012] Furthermore, the process parameters of the electrolytic cleaning tank also include electrolytic current density, alkali concentration, alkali temperature, and electrolysis time, with the electrolytic current density ranging from 5 to 30 A / dm³. 2 The alkaline solution concentration ranges from 0.4% to 5.0%, the alkaline solution temperature ranges from 35% to 60% ℃, and the electrolysis time ranges from 0.5% to 5.0% s.

[0013] Furthermore, the cleaning section also includes an alkaline spray washing tank, an alkaline brush washing tank, a water brush washing tank, and a hot water spray washing tank. Each of the alkaline spray washing tank, alkaline brush washing tank, water brush washing tank, and hot water spray washing tank is equipped with a squeeze roller, and the alkaline spray washing tank, alkaline brush washing tank, electrolytic cleaning tank, water brush washing tank, and hot water spray washing tank are arranged sequentially along the moving direction of the strip.

[0014] Furthermore, the process parameters of the alkaline spray washing tank include alkaline concentration, alkaline temperature, and cleaning time, with the alkaline concentration ranging from 0.5% to 6.0%, the alkaline temperature ranging from 35% to 60% and the cleaning time ranging from 0.5% to 10.0 seconds.

[0015] Furthermore, the process parameters of the alkaline washing tank include the number of washing cycles, brush roller current, alkaline concentration, and alkaline temperature. The number of washing cycles ranges from 2 to 6 times, the brush roller current ranges from 10 to 30A, the alkaline concentration ranges from 0.5% to 5.0%, and the alkaline temperature ranges from 35 to 60℃.

[0016] Furthermore, the process parameters of the water washing tank include the number of washing cycles, the brush roller current, and the washing water temperature. The number of washing cycles ranges from 2 to 6, the brush roller current ranges from 8 to 20A, and the washing water temperature ranges from 25 to 50℃.

[0017] Furthermore, the process parameters of the hot water spray tank include the number of rinsing cycles, water temperature, and fresh water replenishment flow rate. The number of rinsing cycles ranges from 1 to 3, the water temperature ranges from 25 to 50°C, and the fresh water replenishment flow rate ranges from 0.8 to 3.0 m³ / h. 3 / h.

[0018] This invention also provides a cleaning unit, including a cleaning section, a strip surface roughness detector is provided at the inlet side of the cleaning section, and a strip surface cleanliness detector is provided at the outlet side of the cleaning section, and the current data of the electrolytic cleaning tank of the cleaning section is adjusted based on the surface roughness of the strip entering the cleaning section and the surface cleanliness of the strip exiting the cleaning section.

[0019] The present invention has the following beneficial effects:

[0020] In this invention, the roughness of the strip steel before cleaning and the cleanliness after cleaning are obtained. The roughness and cleanliness can be used to adjust the current value during the electrolytic cleaning process to reduce power consumption while ensuring the cleaning effect. In the actual cleaning process, the higher the detected roughness value and the higher the cleanliness value, the higher the current value in the electrolytic cleaning tank should be. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the cleaning unit process provided in an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] See Figure 1This invention provides a method for cleaning cold-rolled strip steel 1, specifically for cleaning the surface of the cold-rolled strip steel 1. In this method, before entering the cleaning section 2, the surface roughness of the strip steel 1 is measured. Similarly, when the strip steel 1 exits the cleaning section 2 after cleaning, its surface cleanliness is measured. The current value of the electrolytic cleaning tank 21 in the cleaning section 2 is adjusted based on the measured roughness and cleanliness. A higher surface roughness value on the inlet side of the cleaning section 2 and a higher surface cleanliness value on the outlet side result in a higher current value in the electrolytic cleaning tank 21. This invention correlates the current value of the electrolytic cleaning tank 21 with the surface roughness and cleanliness of the strip steel 1, adjusting the current value based on the measured results of both. This reduces the energy consumption of the electrolytic cleaning tank 21 while ensuring the cleaning effect of the strip steel 1. Since the cleanliness test of strip steel 1 is carried out after the electrolytic cleaning tank 21, the cleanliness test has a certain lag. However, the surface cleanliness of strip steel 1 is usually stable after being cleaned by the cleaning section 2. Therefore, the lag cleanliness value can also guide the adjustment of the current value in the electrolytic cleaning tank 21. On the one hand, it will not reduce the cleaning effect of strip steel 1, and on the other hand, it can optimize the power consumption of the electrolytic cleaning tank 21.

[0025] In a preferred embodiment, the current value in the electrolytic cleaning tank 21 is adjusted according to the following calculation method:

[0026] I = I min +[(RR min ) / (R max -R min )+(CC min ) / (C max -C min )+(VV min ) / (V max -V min )]×

[0027] (I max -I min ) / 3;

[0028] Where: I—current value of electrolytic cleaning tank 21; I min —Minimum current value; I max —Maximum current value; R—Measured roughness value; R min —Minimum roughness value; R max —Maximum roughness value; C—Measured cleanliness value; C min —Minimum cleanliness value; C max —Maximum cleanliness value; V—Actual operating speed of strip 1; V min —Minimum strip running speed; V max —Maximum strip running speed.

[0029] In the above calculation formula, the current value of the electrolytic cleaning tank 21 is related to the roughness, cleanliness, and running speed of the strip 1, and all three are preset within a range, i.e., they have maximum and minimum values, such as minimum roughness value, maximum roughness value, minimum cleanliness value, maximum cleanliness value, minimum running speed of the strip 1, and maximum running speed of the strip 1. Furthermore, the current of the electrolytic cleaning tank 21 is also limited within a working range, having minimum and maximum current values. During the cleaning process, the measured roughness, measured cleanliness, and actual running speed of the strip 1 are obtained, and the current value of the electrolytic cleaning tank 21 at the corresponding time can be calculated.

[0030] In an optimized embodiment, a roughness detector 3 is installed at the inlet side of the cleaning section 2. This detector can be used to detect the roughness of one or both surfaces of the strip 1. When only one surface is tested, that roughness is taken as the measured roughness value. When both surfaces are tested, the higher roughness value is taken as the measured roughness value of the strip 1. Therefore, there can be one set or two sets of roughness detectors 3. Similarly, a cleanliness detector 4 is installed at the outlet side of the cleaning section 2. This detector can be used to detect the cleanliness of one or both surfaces of the strip 1. When only one surface is tested, that cleanliness is taken as the measured roughness value. When both surfaces are tested, the higher cleanliness value is taken as the measured cleanliness value of the strip 1. Therefore, there can be one set or two sets of cleanliness detectors 4.

[0031] For the electrolytic cleaning tank 21, its process parameters also include electrolytic current density, alkali concentration, alkali temperature, and electrolysis time, and the electrolytic current density ranges from 5 to 30 A / dm³. 2 The alkaline solution concentration ranges from 0.4% to 5.0%, the alkaline solution temperature ranges from 35% to 60% ℃, and the electrolysis time ranges from 0.5% to 5.0 seconds. The electrolytic cleaning tank 21 is equipped with two sets of guiding rollers 211 and two sets of submerged rollers 212. Between the two sets of submerged rollers 212 is an electrode plate 213 for electrolyzing the strip steel 1. The strip steel 1 passes sequentially through one set of guiding rollers 211, one set of submerged rollers 212, the electrode plate 213, the other set of submerged rollers 212, and the other set of guiding rollers 211. Both sets of guiding rollers 211 are located at a higher position and above the liquid in the electrolytic cleaning tank 21, while both sets of submerged rollers 212 and the electrode plate 213 are located at a lower position and within the liquid in the electrolytic cleaning tank 21.

[0032] Furthermore, the other cleaning structures of cleaning section 2 are further refined, including an alkaline spray washing tank 22, an alkaline brush washing tank 23, a water brush washing tank 24, and a hot water spray washing tank 25. Each of these tanks is equipped with a squeeze roller 26, and they are arranged sequentially along the moving direction of the strip 1. Thus, the strip 1, after its roughness has been tested, first enters the alkaline spray washing tank 22, is sprayed with alkaline solution, then brushed in the alkaline brush washing tank 23, and after brushing, enters the electrolytic cleaning tank 21 for electrolysis. Finally, it sequentially enters the water brush washing tank 24 and the hot water spray washing tank 25 for room temperature water brushing and hot water spray washing. The arrangement of the squeeze rollers 26 varies in each washing tank. For example, in the alkaline spray washing tank 22, a set of squeeze rollers 26 can be installed inside its inlet, along with several sets of alkaline spray pipes 221. Each set of alkaline spray pipes 221 sprays and washes the upper and lower surfaces of the strip 1. In the alkaline brush washing tank 23, a set of squeeze rollers 26 is installed inside both the inlet and outlet. Alkaline brush rollers 231 are spaced apart between the two sets of squeeze rollers 26. Each alkaline brush roller 231 corresponds to an alkaline support roller 232. The strip 1 passes between the alkaline brush rollers 231 and the alkaline support rollers 232. Specifically, above the strip 1, the alkaline brush rollers 231 and the alkaline support rollers 232 are staggered. Similarly, below the strip 1... The alkali brush roller 231 and the alkali support roller 232 are also arranged alternately. For the water washing tank 24, a set of squeeze rollers 26 are also provided inside, located inside the inlet of the water washing tank 24, and water brush rollers 241 and water support rollers 242 are also provided. The arrangement of the two is the same as that of the alkali brush roller 231 and alkali support roller 232 in the alkali washing tank 23. The hot water spray washing tank 25 is provided with multiple sets of squeeze rollers 26. Between two adjacent sets of squeeze rollers 26, one or more sets of hot water spray pipes 251 are provided. Each set of hot water spray pipes 251 includes two hot water spray pipes 251, which are used to spray hot water onto the upper and lower surfaces of the strip steel 1 respectively. In addition, a set of squeeze rollers 26 is added inside the outlet of the hot water spray washing tank 25.

[0033] In a preferred embodiment, the process parameters of each of the washing tanks in the cleaning section 2 are controlled. The process parameters of the alkaline spray washing tank 22 include alkaline concentration, alkaline temperature, and cleaning time, with the alkaline concentration ranging from 0.5% to 6.0%, the alkaline temperature ranging from 35% to 60% and the cleaning time ranging from 0.5% to 10.0s. The process parameters of the alkaline brush washing tank 23 include the number of brushing cycles, brush roller current, alkaline concentration, and alkaline temperature, with the number of brushing cycles ranging from 2% to 6%, the brush roller current ranging from 10% to 30A, and the alkaline concentration... The process parameters for the water washing tank 24 include the number of washing cycles, brush roller current, and washing water temperature, with the number of washing cycles ranging from 2 to 6, the brush roller current ranging from 8 to 20A, and the washing water temperature ranging from 25 to 50℃. The process parameters for the hot water spray washing tank 25 include the number of rinsing cycles, water temperature, and fresh water replenishment flow rate, with the number of rinsing cycles ranging from 1 to 3, the water temperature ranging from 25 to 50℃, and the fresh water replenishment flow rate ranging from 0.8 to 3.0 m³ / h. 3 / h. By controlling the process parameters of each washing tank in the cleaning section 2 to be within the above range, the cleaning effect of the strip steel 1 can be guaranteed.

[0034] Of course, since the strip steel 1 passes through each washing tank of the washing section 2 in sequence, the strip steel 1 exiting from the washing section 2 needs to be dried. That is, a dryer 5 should be installed outside the outlet of the hot water spray washing tank 25 to dry the strip steel 1. After the strip steel 1 is dried by the dryer 5, its surface cleanliness is detected by the cleanliness detector 4.

[0035] The following are three sets of embodiments based on the above cleaning method, specifically:

[0036] Example 1: One roughness tester 3 is installed on the upper outer surface of the inlet of cleaning section 2, and one cleanliness tester 4 is installed on the upper outer surface of the outlet of cleaning section 2. The roughness to be tested is 0.80 μm, and the required surface contaminant removal rate of strip steel 1 after cleaning is 90%.

[0037] Example 2: A roughness detector 3, one set, is installed on the upper outer surface of the inlet of cleaning section 2; a cleanliness detector 4, one set, is installed on the upper outer surface of the outlet of cleaning section 2. The roughness to be measured is 0.60 μm, and the required surface contaminant removal rate of strip steel 1 after cleaning is 90%.

[0038] Example 3: A roughness detector 3, one set, is installed on the upper outer surface of the inlet of cleaning section 2; a cleanliness detector 4, one set, is installed on the upper outer surface of the outlet of cleaning section 2. The roughness to be measured is 0.60 μm, and the required surface contaminant removal rate of strip steel 1 after cleaning is 95%.

[0039]

[0040]

[0041] In the above three embodiments, the surface cleanliness of the strip steel 1 meets the production control requirements, the pollutant removal rate reaches more than 90%, the cleaning effect is very good, and based on this, the power consumption of the electrolytic cleaning tank 21 can be minimized.

[0042] This invention also provides a cleaning unit, including a cleaning section 2. A surface roughness detector 3 for strip steel 1 is installed at the inlet side of the cleaning section 2, and a surface cleanliness detector 4 for strip steel 1 is installed at the outlet side of the cleaning section 2. When the strip steel 1 enters the cleaning section 2 for cleaning, the roughness detector 3 detects the surface roughness of the strip steel 1, and the cleanliness detector 4 detects the cleanliness after cleaning. The current value of the electrolytic cleaning tank 21 is calculated based on the roughness and cleanliness, and the electrolytic cleaning tank 21 operates according to the current value. The cleaning unit provided in this embodiment uses the above-mentioned cleaning method to clean the strip steel 1, thereby not only ensuring the cleaning effect of the strip steel 1, but also minimizing the power consumption of the electrolytic cleaning tank 21 and reducing the cleaning cost of the strip steel 1.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for cleaning cold-rolled strip steel, characterized in that: The current data of the electrolytic cleaning tank in the cleaning section is adjusted by feedback based on the surface roughness of the strip entering the cleaning section and the surface cleanliness of the strip exiting the cleaning section. The larger the surface roughness value of the strip at the inlet side of the cleaning section and the higher the surface cleanliness value of the strip at the outlet side, the higher the current value of the electrolytic cleaning tank. Specifically, the current value of the electrolytic cleaning tank is: I=I min +[(R-R min ) / (R max- R min )+(C-C min ) / (C max -C min )+(V-V min ) / (V max- V min )]×(I max- I min ) / 3; Where: I—current value of the electrolytic cleaning tank; I min —Minimum current value; I max —Maximum current value; R—Measured roughness value; R min —Minimum roughness value; R max —Maximum roughness value; C—Measured cleanliness value; C min —Minimum cleanliness value; C max —Maximum cleanliness value; V—Actual running speed of the strip; V min —Minimum strip running speed; V max —Maximum strip running speed.

2. The method for cleaning cold-rolled strip steel as described in claim 1, characterized in that: The roughness of the upper and lower surfaces of the strip is tested, and the higher roughness value is taken as the measured roughness value of the strip; the cleanliness of the upper and lower surfaces of the strip is tested, and the higher cleanliness value is taken as the measured cleanliness value of the strip.

3. The method for cleaning cold-rolled strip steel as described in claim 1, characterized in that: The process parameters for the electrolytic cleaning tank also include electrolytic current density, alkali concentration, alkali temperature, and electrolysis time, with the electrolytic current density ranging from 5 to 30 A / dm³. 2 The alkaline solution concentration ranges from 0.4% to 5.0%, the alkaline solution temperature ranges from 35% to 60% ℃, and the electrolysis time ranges from 0.5% to 5.0% s.

4. The method for cleaning cold-rolled strip steel as described in claim 1, characterized in that: The cleaning section also includes an alkaline spray washing tank, an alkaline brush washing tank, a water brush washing tank, and a hot water spray washing tank. Each of the alkaline spray washing tank, alkaline brush washing tank, water brush washing tank, and hot water spray washing tank is equipped with a squeeze roller, and the alkaline spray washing tank, alkaline brush washing tank, electrolytic cleaning tank, water brush washing tank, and hot water spray washing tank are arranged sequentially along the moving direction of the strip.

5. The method for cleaning cold-rolled strip steel as described in claim 4, characterized in that: The process parameters of the alkaline spray washing tank include alkaline concentration, alkaline temperature, and cleaning time. The alkaline concentration ranges from 0.5% to 6.0%, the alkaline temperature ranges from 35% to 60% and the cleaning time ranges from 0.5% to 10.0 seconds.

6. The method for cleaning cold-rolled strip steel as described in claim 5, characterized in that: The process parameters of the alkaline washing tank include the number of washing cycles, brush roller current, alkaline concentration, and alkaline temperature. The number of washing cycles ranges from 2 to 6, the brush roller current ranges from 10 to 30A, the alkaline concentration ranges from 0.5% to 5.0%, and the alkaline temperature ranges from 35 to 60℃.

7. The method for cleaning cold-rolled strip steel as described in claim 5, characterized in that: The process parameters of the water washing tank include the number of washing cycles, the brush roller current, and the washing water temperature. The number of washing cycles ranges from 2 to 6, the brush roller current ranges from 8 to 20A, and the washing water temperature ranges from 25 to 50℃.

8. The method for cleaning cold-rolled strip steel as described in claim 5, characterized in that: The process parameters for the hot water spray tank include the number of rinses, water temperature, and fresh water replenishment flow rate. The number of rinses ranges from 1 to 3, the water temperature ranges from 25 to 50°C, and the fresh water replenishment flow rate ranges from 0.8 to 3.0 m³ / h. 3 / h.

9. A cleaning unit, comprising a cleaning section, characterized in that: A strip surface roughness detector is installed at the inlet side of the cleaning section, and a strip surface cleanliness detector is installed at the outlet side of the cleaning section. The current data of the electrolytic cleaning tank in the cleaning section is adjusted based on the surface roughness of the strip entering the cleaning section and the surface cleanliness of the strip exiting the cleaning section. Specifically, the current value of the electrolytic cleaning tank is: I=I min +[(R-R min ) / (R max- R min )+(C-C min ) / (C max -C min )+(V-V min ) / (V max- V min )]×(I max- I min ) / 3; Where: I—current value of the electrolytic cleaning tank; I min —Minimum current value; I max —Maximum current value; R—Measured roughness value; R min —Minimum roughness value; R max —Maximum roughness value; C—Measured cleanliness value; C min —Minimum cleanliness value; C max —Maximum cleanliness value; V—Actual running speed of the strip; V min —Minimum strip running speed; V max —Maximum strip running speed.

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