Method for detecting cleanliness of non-oriented silicon steel cleaning solution

Abstract

The application discloses a cleanliness detection and analysis method for non-oriented silicon steel cleaning solution, which comprises the following steps: step 1: taking the cleaning solution sample containing dirt from the cleaning solution circulating tank, and carrying out dehydration, drying and grinding to obtain the dirt powder sample; step 2: calculating the cleanliness of the cleaning solution in the cleaning solution circulating tank according to the cleaning solution sample containing dirt and the dirt powder sample; step 3: establishing the cleaning solution cleanliness evaluation standard according to the cleanliness of the cleaning solution sample containing dirt; and step 4: controlling the discharge and liquid change of the cleaning solution containing dirt according to the cleaning solution cleanliness evaluation standard. The application can simply and intuitively understand the state of the cleaning solution in the current cleaning section circulating tank, and can make timely online adjustment on the use and discharge of the cleaning solution according to the cleanliness rating of the cleaning solution.

Description

TECHNICAL FIELD

[0001] The present application relates to a cleaning control method of a metallurgical process, in particular to a cleanliness detection and analysis method for cleaning solution of non-oriented silicon steel. BACKGROUND

[0002] Non-oriented silicon steel is a low-carbon ferrosilicon alloy, and the grains in the silicon steel plate are randomly oriented after deformation and annealing. The continuous annealing coating production line process of non-oriented silicon steel mainly includes: unwinding → pre-cleaning → annealing → post-cleaning → coating baking → quality inspection → winding.

[0003] The pre-cleaning section of the prior art is horizontal cleaning, and the online cleaning tank is divided into an immersion tank, a 1st brushing tank, an electrolytic cleaning tank, a 2nd brushing tank, and a hot water spraying tank. During online cleaning, the immersion tank and the 1st brushing tank share a 1st cleaning circulating tank with a volume of 35m 3 , and the cleaning solution is a lye with a concentration of 1.5±0.3wt%; the electrolytic cleaning tank independently uses a 2nd cleaning circulating tank with a volume of 35m 3 , and the cleaning solution is a lye with a concentration of 1.5±0.3wt%; the 2nd brushing tank independently uses a brushing circulating tank with a volume of 10m 3 , and the cleaning solution is pure water; the hot water spraying tank independently uses a circulating tank with a volume of 10m 3 ; through the above cleaning process, the dirt on the surface of the non-oriented silicon steel is thoroughly cleaned.

[0004] The pre-cleaning process of the prior art has the following problems:

[0005] 1. Because the cleaning capacity and cleaning load of the immersion tank, the 1st brushing tank, and the electrolytic cleaning tank are in a saturated state for a long time, a large amount of dirt is suspended in the cleaning solution of the 1st and 2nd cleaning circulating tanks, and the main components of the dirt are a mixture of silicon mud and iron powder. At present, there is no effective detection method for the content of dirt in the cleaning solution, and there is no unified measurement standard for the cleanliness of the cleaning solution, which reduces the cleaning capacity in the cleaning circulating tank and affects the quality of the non-oriented silicon steel surface and the coating performance in the subsequent cleaning.

[0006] 2. The content of dirt in the two cleaning circulating tanks cannot be determined, and the dirt cannot be discharged in time, which easily blocks the circulating pipelines and nozzles in the tank body, further reduces the cleaning capacity, and affects the cleaning effect.

[0007] 3. In order to ensure the effectiveness of the cleaning capacity, the cleaning solution is usually discharged once every two days according to the experience of cleaning operation, and the cleaning solution is re-prepared, so that the cleaning solution cannot be fully utilized, and the lye and pure water are wasted.

[0008] The Chinese invention patent application CN202011598538.9 discloses a cleanliness detection system of an immersion control unit and a cleanliness detection method thereof. The cleanliness detection method is as follows: connecting a liquid source, an immersion control unit and a particle detection device, and setting the immersion control unit on the outside of an objective lens and above a substrate; the liquid source provides liquid to the particle detection device through a calibration flow path bypassing the immersion control unit, and the particle detection device detects the content of particulate matters in the liquid as the background content of particulate matters of the cleanliness detection system; the liquid source is used to provide liquid to the immersion control unit, and the liquid fills the space between the objective lens and the substrate; the liquid is pumped through the immersion control unit and introduced into the particle detection device for detection of the content of particulate matters, and the experimental content of particulate matters obtained by subtraction of the background content of particulate matters is taken as the cleanliness evaluation index of the immersion control unit. The method is mainly applied to the detection of immersion liquid of a photolithography machine in the field of photolithography. Since the refractive index of the strip steel cleaning liquid is low, and the dirt in the cleaning liquid is easy to contaminate the probe, the detection effect is affected, and the method cannot be applied to the cleaning process of the strip steel in the metallurgical industry. SUMMARY

[0009] The purpose of the present application is to provide a cleanliness detection and analysis method for cleaning liquid of non-oriented silicon steel, which can conveniently and intuitively understand the state of the cleaning liquid in the current cleaning section circulating tank, and can make timely online adjustment of the use and discharge of the cleaning liquid according to the cleanliness rating of the cleaning liquid.

[0010] The present application is implemented as follows:

[0011] A cleanliness detection and analysis method for cleaning liquid of non-oriented silicon steel, comprising the following steps:

[0012] Step 1: taking a cleaning liquid sample containing dirt from the cleaning liquid circulating tank, the volume of the cleaning liquid sample containing dirt is V 取1 , and performing dehydration, drying and grinding to obtain a dirt powder sample;

[0013] Step 2: calculating the cleanliness of the cleaning liquid in the cleaning liquid circulating tank according to the cleaning liquid sample containing dirt and the dirt powder sample;

[0014] Step 2.1: taking a cleaning liquid sample not containing dirt, the volume of the cleaning liquid sample not containing dirt is also V 取1 , calculating the theoretical density p 理论 of the cleaning liquid sample not containing dirt, and the calculation formula is:

[0015]

[0016] , wherein V 循 is the volume of the cleaning liquid circulating tank;

[0017] C 循The concentration of the cleaning solution sample that is free of contaminants;

[0018] C 原 This refers to the concentration of the original cleaning solution.

[0019] P 原 This refers to the density of the original cleaning solution.

[0020] 1.0 is the density of pure water used to prepare the cleaning solution in the cleaning solution circulation tank, which is free of contaminants;

[0021] Step 2.2: Based on the theoretical density ρ 理论 Calculate the theoretical weight m of the cleaning fluid sample free of contaminants. 理论 The calculation formula is:

[0022] m 理论 =V 取1 ×ρ 理论 Formula (2);

[0023] Step 2.3: Calculate the density ρ of the contaminant powder sample. 污物 The calculation formula is:

[0024] ρ 污物 =m 污物 / V 取2 Formula (3)

[0025] Where, m 污物 This is the actual weight of the dirt powder sample;

[0026] V 取2 This represents the volume of the dirt powder sample.

[0027] Step 2.4: Based on the theoretical weight m 理论 and the density ρ of dirt powder 污物 Calculate the volume V of contaminants in the cleaning fluid sample containing contaminants. 污物 The calculation formula is:

[0028]

[0029] Where, m 实际 This is the actual weight of the cleaning solution sample containing contaminants.

[0030] Step 2.4: Calculate the cleanliness of the cleaning solution sample containing contaminants. The calculation formula is as follows:

[0031] Cleanliness = (1-V) 污物 / V 取1 )×100% formula (5);

[0032] Step 3: Establish a cleanliness assessment standard for cleaning solutions based on the cleanliness of the cleaning solution samples containing contaminants;

[0033] Step 4: Discharge and replace the cleaning solution containing dirt according to the cleaning solution cleanliness evaluation standard.

[0034] The cleaning solution cleanliness evaluation standard is:

[0035] When 85% < cleanliness ≤ 100%, the cleaning solution cleanliness is rated as I level;

[0036] When 70% < cleanliness ≤ 85%, the cleaning solution cleanliness is rated as II level;

[0037] When 55% < cleanliness ≤ 70%, the cleaning solution cleanliness is rated as III level;

[0038] When 40% < cleanliness ≤ 55%, the cleaning solution cleanliness is rated as IV level;

[0039] When cleanliness ≤ 40%, the cleaning solution cleanliness is rated as V level.

[0040] In the step 4,

[0041] When the cleaning solution cleanliness is rated as I level or II level, the cleaning solution is not discharged, i.e. the cleaning solution continues to be used;

[0042] When the cleaning solution cleanliness is rated as III level, half of the cleaning solution in the cleaning solution circulating tank is discharged, and new cleaning solution is supplemented;

[0043] When the cleaning solution cleanliness is rated as IV level, half of the cleaning solution in the cleaning solution circulating tank is discharged for the first time, and new cleaning solution is supplemented for the first time; after the first time of supplementing the cleaning solution, half of the cleaning solution in the cleaning solution circulating tank is discharged for the second time, and new cleaning solution is supplemented for the second time;

[0044] When the cleaning solution cleanliness is rated as V level, the cleaning solution in the cleaning solution circulating tank is discharged, the cleaning solution circulating tank is washed with pure water, the spray nozzles are dredged, and new cleaning solution is supplemented.

[0045] When the cleaning solution cleanliness is rated as III level, the liquid level and the concentration of the supplemented cleaning solution reach the liquid level and the concentration of the cleaning solution when sampling in the step 1.

[0046] When the cleaning solution cleanliness is rated as IV level, the liquid level and the concentration of the cleaning solution after the first time of supplementing reach the liquid level and the concentration of the cleaning solution when sampling in the step 1; the liquid level and the concentration of the cleaning solution after the second time of supplementing reach the liquid level and the concentration of the cleaning solution when sampling in the step 1.

[0047] Compared with the prior art, the present application has the following beneficial effects:

[0048] 1、The present application can quickly and accurately calculate the content of dirt in the cleaning liquid by sampling the cleaning liquid containing dirt, thereby directly reflecting the cleanliness of the cleaning liquid in the cleaning liquid circulating tank of the current cleaning section, having good guiding significance for the use, discharge and replenishment of the cleaning liquid, being beneficial to the full use of the cleaning liquid and avoiding the waste of cleaning liquid caused by discharging the cleaning liquid according to experience.

[0049] 2、The present application grades the use state of the cleaning liquid based on the cleanliness of the cleaning liquid, which is beneficial to accurately assessing the use state of the cleaning liquid and taking corresponding measures on the cleaning liquid, ensuring the recycling use of the cleaning liquid, guaranteeing the normal and effective operation of the cleaning process of non-oriented silicon steel, improving the working efficiency of the cleaning section and making up for the deficiency of periodically discharging and replacing the cleaning liquid relying on manual experience.

[0050] 3、The present application can timely, accurately and directly understand the cleanliness state of the cleaning liquid, can ensure the cleaning effect of the cleaning liquid on non-oriented silicon steel, is beneficial to realizing the accurate control of coating quality and thick coating film thickness, improving the film thickness control uniformity of non-oriented silicon steel, guaranteeing the product quality and especially solving the production restriction caused by unstable coating quality of extremely thick coating silicon steel sheet, meeting the demand of electrical steel for domestic large generators.

[0051] 4、The present application can complete sampling, calculation and liquid replacement when the cleaning liquid circulating tank is not in maintenance shutdown, which is convenient and efficient and does not affect the process of the cleaning section, and guarantees the cleaning effect of subsequent non-oriented silicon steel through accurate control of the cleanliness of the cleaning liquid.

[0052] The present application can quantify the content of dirt in the cleaning liquid sample through data, can simply and directly understand the state of the cleaning liquid in the current cleaning section circulating tank, grade the cleanliness of the cleaning liquid, establish the standard of cleanliness grading and liquid replacement, thereby making timely online adjustment on the use and discharge of the cleaning liquid according to the cleanliness grading, effectively stabilizing the cleaning effect and eliminating the quality defects of non-oriented silicon steel caused by the blockage of the spray nozzle of the cleaning section. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 is the flow chart of the cleanliness detection and analysis method for the cleaning liquid of non-oriented silicon steel. DETAILED DESCRIPTION

[0054] The present application will be further described below in combination with the drawings and specific embodiments.

[0055] Please refer to the accompanying Figure 1 A cleanliness detection and analysis method for the cleaning liquid of non-oriented silicon steel, comprising the following steps:

[0056] Step 1: Take the sample of the cleaning solution containing dirt from the cleaning solution circulating tank, the volume of the sample of the cleaning solution containing dirt is V 取1 , and then dehydrate, dry, grind and so on to obtain the sample of dirt powder. The sampling of the sample of the cleaning solution containing dirt can be performed at any time during the operation of the cleaning process, and the volume V 取1 can be measured by a measuring cup, without waiting for the maintenance shutdown to be performed, so as to reduce the influence on the operation of the cleaning section, and to make appropriate adjustment to the cleaning solution in the cleaning solution circulating tank during the maintenance shutdown, which is beneficial to ensure the cleaning effect of the non-oriented silicon steel after the maintenance.

[0057] Step 2: Calculate the cleanliness of the cleaning solution in the cleaning solution circulating tank according to the sample of the cleaning solution containing dirt and the sample of dirt powder.

[0058] Step 2.1: Take the sample of the cleaning solution not containing dirt, and the volume of the sample of the cleaning solution not containing dirt is also V 取 1. The sample of the cleaning solution not containing dirt can be obtained when the initial proportioning of the cleaning solution is completed, and the theoretical density p 理论 of the cleaning solution not containing dirt is calculated, and the calculation formula is as follows:

[0059]

[0060] , wherein V 循 is the volume of the cleaning solution circulating tank (m 3 );

[0061] C 循 is the concentration of the sample of the cleaning solution not containing dirt (wt%), which is determined by the requirement of the cleaning process;

[0062] C 原 is the concentration of the cleaning solution (wt%);

[0063] P 原 is the density of the cleaning solution;

[0064] 1.0 is the density of pure water used for proportioning the cleaning solution not containing dirt in the cleaning solution circulating tank.

[0065] Step 2.2: Calculate the theoretical weight m 理论 of the sample of the cleaning solution not containing dirt according to the theoretical density p 理论 , and the calculation formula is as follows:

[0066] m 理论 = V 取1 × p 理论 Equation (2).

[0067] Step 2.3: Calculate the dirt powder density p 污物 of the sample of dirt powder, and the calculation formula is as follows:

[0068] p 污物 = m 污物 V 取2 Equation (3)

[0069] wherein m 污物 is the actual weight of the dirt powder sample, which can be measured by a balance;

[0070] V 取2 is the volume of the dirt powder sample, which can be measured by a measuring cup.

[0071] Step 2.4: calculate the dirt volume V 理论 in the cleaning liquid sample containing dirt according to the theoretical weight m 污物 and the dirt powder density p 污物 , and the calculation formula is:

[0072]

[0073] wherein m 实际 is the actual weight of the cleaning liquid sample containing dirt, which can be measured by a balance after sampling.

[0074] Step 2.4: calculate the cleanliness of the cleaning liquid sample containing dirt, and the calculation formula is:

[0075] Cleanliness = (1-V 污物 / V 取1 ) x 100% Equation (5).

[0076] The cleanliness of the cleaning liquid containing dirt can be quickly calculated through the cleaning liquid sample containing dirt, the cleaning liquid sample not containing dirt and the dirt powder sample, so as to guide the replacement of the cleaning liquid and the replacement amount, thereby reducing unnecessary waste of the cleaning liquid on the basis of ensuring the cleaning effect of the non-oriented silicon steel.

[0077] Step 3: establish a cleaning liquid cleanliness evaluation standard according to the cleanliness of the cleaning liquid sample containing dirt. The cleanliness evaluation standard can be established according to the cleaning process requirements to meet the cleaning needs of different non-oriented silicon steels and ensure the cleaning effect of the non-oriented silicon steel.

[0078] When 85% < cleanliness < 100%, the cleaning liquid cleanliness is rated as I (excellent);

[0079] When 70% < cleanliness < 85%, the cleaning liquid cleanliness is rated as II (good);

[0080] When 55% < cleanliness < 70%, the cleaning liquid cleanliness is rated as III (medium);

[0081] When 40% < cleanliness ≤ 55%, the cleaning liquid cleanliness is rated as level IV (poor);

[0082] When the cleanliness ≤ 40%, the cleaning liquid cleanliness is rated as level V (very poor).

[0083] The cleaning liquid cleanliness rating standard is clear and detailed, which can effectively guide the operator to operate whether to replace the cleaning liquid containing dirt and the amount of replacement, and takes into account the cleaning effect of the cleaning liquid and the full use of the cleaning liquid stock solution.

[0084] Step 4: According to the cleaning liquid cleanliness rating standard, the discharge and replacement of the cleaning liquid containing dirt are controlled. By using different replacement methods for cleaning liquids of different ratings, it can ensure that the cleanliness of the cleaning liquid meets the cleaning requirements, the spray nozzle is unobstructed, and the inefficient operation of replacing all the cleaning liquid containing dirt and the waste of the cleaning liquid stock solution are avoided.

[0085] When the cleaning liquid cleanliness is rated as level I (excellent) or level II (good), the cleaning liquid is not discharged, i.e., the cleaning liquid can continue to be used. At this time, although the cleaning liquid contains dirt, the cleanliness is good, the spray is smooth, and the cleaning effect can meet the cleaning process requirements of non-oriented silicon steel.

[0086] When the cleaning liquid cleanliness is rated as level III (medium), half of the cleaning liquid in the cleaning liquid circulating tank is discharged, and new cleaning liquid is supplemented, so that the liquid level and concentration of the supplemented new cleaning liquid reach the liquid level and concentration of the cleaning liquid when sampling in step 1. At this time, the cleanliness of the cleaning liquid is general, i.e., the cleaning effect is general, and a small part of the spray nozzles may be blocked. Replacing half of the cleaning liquid can reduce the dirt content and improve the cleanliness of the cleaning liquid, without the need to replace all the cleaning liquid, which can reduce the production cost and improve the efficiency of the replacement operation while ensuring the subsequent strip cleaning effect.

[0087] When the cleaning liquid cleanliness is rated as level IV (poor), half of the cleaning liquid in the cleaning liquid circulating tank is discharged for the first time, and new cleaning liquid is supplemented for the first time, so that the liquid level and concentration of the supplemented new cleaning liquid reach the liquid level and concentration of the cleaning liquid when sampling in step 1. After completing the first supplement of the cleaning liquid, half of the cleaning liquid in the cleaning liquid circulating tank is discharged for the second time, and new cleaning liquid is supplemented for the second time, so that the liquid level and concentration of the supplemented new cleaning liquid reach the liquid level and concentration of the cleaning liquid when sampling in step 1. At this time, the cleanliness of the cleaning liquid is poor, i.e., the cleaning effect is poor, and most of the spray nozzles may be blocked. Replacing half of the cleaning liquid twice can reduce the dirt content and improve the cleanliness of the cleaning liquid, without the need to replace all the cleaning liquid, which can reduce the production cost and improve the efficiency of the replacement operation while ensuring the subsequent strip cleaning effect.

[0088] When the cleaning liquid cleanliness is rated as V (very poor), the cleaning liquid in the cleaning liquid circulating tank is emptied, and the cleaning liquid circulating tank is washed with pure water, the spray nozzles are dredged, and then new cleaning liquid is prepared. The parameters of the new cleaning liquid are determined according to the cleaning process requirements of the next piece of non-oriented silicon steel. At this time, the cleaning liquid is very dirty, that is, the cleaning effect is very poor, the spray nozzles are interrupted, and the liquid needs to be replaced to ensure the cleaning effect of the subsequent non-oriented silicon steel.

[0089] Example 1:

[0090] In the pre-cleaning process of a certain non-oriented silicon steel, a cleaning liquid sample containing dirt was taken from the cleaning liquid circulating tank during maintenance shutdown. In this embodiment, the cleaning liquid stock solution concentration C 原 of the cleaning liquid used for preparation is 28wt%, the cleaning liquid stock solution density P 原 is 1.3g / ml, the volume V 循 of the cleaning liquid circulating tank is 35m 3 , and the concentration C 循 of the cleaning liquid after preparation is 1.5wt%.

[0091] Step 1: Take a cleaning liquid sample containing dirt from the cleaning liquid circulating tank, and measure the volume V 取1 of the cleaning liquid sample containing dirt by a measuring cup to be 250ml, and measure the actual weight m 实际 of the cleaning liquid sample by a balance to be 325g.

[0092] The cleaning liquid sample containing dirt is subjected to dehydration, drying, grinding and other processes to obtain a dirt powder sample.

[0093] Step 2: Calculate the cleaning liquid cleanliness of the cleaning liquid sample containing dirt.

[0094] Step 2.1: Take a cleaning liquid sample without dirt with a volume V 取1 of 250ml before the cleaning process starts, and calculate the theoretical density p 理论 of the cleaning liquid sample without dirt according to formula (1) to be 1.016g / ml.

[0095] Step 2.2: Calculate the theoretical weight m 理论 of the cleaning liquid sample without dirt according to formula (2) to be V 取1 * p 理论 = 250*1.016 = 254g.

[0096] Step 2.3: Measure the volume V 取2 of the dirt powder sample by a measuring cup to be 250ml, and measure the actual weight m 污物 of the dirt powder sample by a balance to be 305g.

[0097] The dirt powder density p of the dirt powder sample is calculated according to formula (3) 污物 = m 污物 / V 取2 = 305 / 250 = 1.22 g / ml.

[0098] Step 2.4: The dirt volume V in the cleaning liquid sample containing dirt is calculated according to formula (4) 污物 = (m actual - m theoretical) / p dirt = (325 - 254) / 1.22 = 58.20 ml.

[0099] Step 2.4: The cleanliness of the cleaning liquid sample containing dirt is calculated according to formula (5) = (1 - V 污物 / V 取1 ) x 100% = (1 - 58.20 / 250) x 100% = 76.72%.

[0100] Step 3: 70% < 76.72% < 85%, the cleanliness is rated as level II (good).

[0101] Step 4: The cleanliness is rated as level II (good), and the cleaning liquid is not discharged, i.e. although the cleaning liquid contains dirt, the cleanliness of the cleaning liquid is good, and the cleaning liquid can still be used, the spraying is smooth, and the cleaning effect can meet the cleaning process requirements of non-oriented silicon steel.

[0102] The above merely describes the preferred embodiments of the present application, but not for limiting the protection scope of the present application, thus, any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for detecting cleanliness of a non-oriented silicon steel cleaning solution, characterized by: The method comprises the following steps: Step 1: take the soiled cleaning solution sample from the cleaning solution circulating tank, the volume of the soiled cleaning solution sample is V 取1 and dehydrate, dry and grind to obtain the soiled powder sample; Step 2: Calculate the cleanliness of the cleaning liquid containing the dirt according to the cleaning liquid sample containing the dirt and the dirt powder sample; Step 2.1: Take the sample of the clean washing liquid, the volume of the sample of the clean washing liquid is also V 取1 , calculate the theoretical density p of the sample of the clean washing liquid 理论 , the calculation formula is: wherein V 循 is the volume of the cleaning liquid circulation tank; C 循 Concentration for clean cleaning fluid sample; C 原 For cleaning liquid stock concentration; P 原 Density of the cleaning solution stock solution; 1.0 is the density of pure water used to prepare the cleaning liquid in the cleaning liquid circulating tank without the dirt; Step 2.2: Calculate the theoretical weight m of the cleaning fluid sample without dirt 理论 Calculate the theoretical weight m of the cleaning fluid sample without dirt 理论 , the calculation formula is: m 理论 = V 取1 x p 理论 Equation (2); Step 2.3: Calculate the soil powder density p of the soil powder sample 污物 The calculation formula is: p 污物 = m 污物 / V 取2 Equation (3) wherein m 污物 is the actual weight of the soil powder sample; V 取2 V is the volume of the dirt powder sample; Step 2.4: Calculate the theoretical weight m 理论 and the dirt powder density p 污物 Calculate the volume of dirt V in the sample of cleaning fluid containing dirt 污物 with the formula: wherein m 实际 is the actual weight of the sample of cleaning fluid containing soil; Step 2.5: Calculate the cleanliness of the cleaning liquid sample containing the dirt according to the following formula: Cleanliness = (1 - V 污物 / V 取1 ) x 100% Equation (5); Step 3: Establish the cleaning liquid cleanliness evaluation standard according to the cleanliness of the cleaning liquid sample containing the dirt; Step 4: Control the discharge and replacement of the cleaning liquid containing the dirt according to the cleaning liquid cleanliness evaluation standard.

2. The method for detecting cleanliness of a cleaning solution for non-oriented silicon steel according to claim 1, characterized by: The cleaning liquid cleanliness evaluation standard is as follows: When 85% < cleanliness ≤ 100%, the cleaning liquid cleanliness is evaluated as Grade I; When 70% < cleanliness ≤ 85%, the cleaning liquid cleanliness is evaluated as Grade II; When 55% < cleanliness ≤ 70%, the cleaning liquid cleanliness is evaluated as Grade III; When 40% < cleanliness ≤ 55%, the cleaning liquid cleanliness is evaluated as Grade IV; When cleanliness ≤ 40%, the cleaning liquid cleanliness is evaluated as Grade V.

3. The method for detecting cleanliness of a cleaning solution for non-oriented silicon steel according to claim 2, characterized by: In the step 4, When the cleaning liquid cleanliness is evaluated as Grade I or Grade II, the cleaning liquid is not discharged, i.e. the cleaning liquid continues to be used; When the cleaning liquid cleanliness is evaluated as Grade III, half of the cleaning liquid in the cleaning liquid circulating tank is discharged, and new cleaning liquid is prepared; When the cleaning liquid cleanliness is evaluated as Grade IV, half of the cleaning liquid in the cleaning liquid circulating tank is discharged for the first time, and new cleaning liquid is prepared for the first time; after the first replacement of the cleaning liquid, half of the cleaning liquid in the cleaning liquid circulating tank is discharged for the second time, and new cleaning liquid is prepared for the second time; When the cleaning liquid cleanliness is evaluated as Grade V, the cleaning liquid in the cleaning liquid circulating tank is discharged, the cleaning liquid circulating tank is washed with pure water, and new cleaning liquid is prepared after the spray nozzles are dredged.

4. The method for detecting cleanliness of a cleaning solution for non-oriented silicon steel according to claim 3, characterized by: When the cleaning liquid cleanliness is evaluated as Grade III, the liquid level and the concentration of the prepared cleaning liquid reach the liquid level and the concentration of the cleaning liquid when the sample is taken in the step 1.

5. The method for detecting cleanliness of a cleaning solution for non-oriented silicon steel according to claim 3, characterized by: When the cleaning liquid cleanliness is evaluated as Grade IV, the liquid level and the concentration of the prepared cleaning liquid for the first time reach the liquid level and the concentration of the cleaning liquid when the sample is taken in the step 1; the liquid level and the concentration of the prepared cleaning liquid for the second time reach the liquid level and the concentration of the cleaning liquid when the sample is taken in the step 1.

Images