A method for improving strip spray drip marks

Abstract

The present invention provides a method for improving the spray dripping marks of strips, comprising a spray bar beam array formed by arranging more than one spray bar beam in parallel, wherein the spray bar beam in a spraying state forms a liquid spraying section to output liquid to the surface of the strip; the starting end of the liquid spraying section is located at the spray bar beam N1 closest to the spray outlet of the spray bar beam array, and the end is located at the spray bar beam Nn in the spraying state closest to the spray inlet; the length of the liquid spraying section is proportional to the maximum speed V of the strip passing through the spraying process max , actual speed V act Matching; when the strip passes through the spraying process section, the strip part that needs to be sprayed receives the liquid medicine spraying time to reach the specified liquid medicine reaction time, and the liquid medicine spraying section of the spraying process is closest to the entrance of the spraying process, so as to reduce the probability of the strip being contaminated by dripping liquid before receiving the spraying; the present invention can effectively improve the problem of strip spray drip marks and can greatly improve product quality.

Description

Technical Field

[0001] The invention relates to the technical field of spraying process, in particular to a method for improving spray drip marks of strips. Background Art

[0002] Normal continuous production lines with spray cleaning functions have multiple groups of spray beams. The number of rows of open spray beams is related to the speed of the process section. If the process section runs at normal startup speed, the system controls the opening of the spray beams from the outlet of the process section in sequence according to the relationship between the set flow rate and speed and the reaction time after the set strip contacts the liquid medicine. When the speeds of the front and rear roll process sections of the strip are inconsistent, especially when the speed of the front roll process section is higher than that of the rear roll, the spray beam area that is not sprayed near the entrance area (such as the cover plate and the nozzle of the spray beam) has residual liquid dripping irregularly onto the surface of the strip due to acid mist condensation or leakage. The strip then enters the normal spray area, which is equivalent to over-cleaning of part of the strip. This phenomenon is called spray drip marks, which causes product quality defects. Summary of the invention

[0003] The present invention provides a method for improving strip spray drip marks, which can effectively improve the strip spray drip mark problem and greatly improve product quality.

[0004] The present invention adopts the following technical solutions.

[0005] A method for improving strip spray drip marks, used for treating strips with liquid medicine in a spraying process, wherein the spraying process includes a spray bar beam array formed by arranging more than one spray bar beam in parallel, and a spray bar beam in a spraying condition in the spray bar beam array forms a liquid medicine spraying section in the process to output liquid medicine to the surface of the strip; the starting end of the liquid medicine spraying section is located at the spray bar beam N1 closest to the spray outlet of the spray bar beam array, and the end is located at the spray bar beam Nn closest to the spray inlet and in the spraying condition; the length of the liquid medicine spraying section is related to the actual speed V of the strip passing through the spraying process act Matching; when the strip passes through the spraying process section, the strip part that needs to be sprayed receives the liquid spraying time reaching the specified liquid reaction time, and the liquid spraying section of the spraying process is closest to the entrance of the spraying process, so that the strip sent to the spraying process later can be sprayed as soon as possible to reduce the probability of being contaminated by dripping liquid before being sprayed.

[0006] In the spray bar beam array, the number of spray bar beams is n; the number of spray bar beams in the spraying state is m,

[0007] That is, the number of rows of spray bar beams opened in the spraying process;

[0008] Assume the length of the boom beam array is L, in meters;

[0009] The actual speed of the strip through the spraying process is V act , the unit is meter / min;

[0010] The specified liquid reaction time is Tref, in seconds;

[0011] The length of the strip part to be sprayed is Lref, in millimeters;

[0012] The relationship between the above parameters is expressed as follows in Formula 1:

[0013]

[0014] According to L ref The value of is compared with the cumulative distance from the spray process outlet to a single boom beam, and then the number of rows of open boom beams is inferred using Formula 2:

[0015]

[0016] Each spray bar beam is controlled by a pneumatic valve connected to it to determine whether the spray bar beam is in the spraying condition; the spray bar beam array works in the normal spraying mode or the interval spraying mode; in the spraying process, the strip conveying path outside the liquid spraying section is a risk area where there is no working spray bar beam above and there is a risk of liquid dripping, and the strip is prone to dripping defects due to liquid dripping contamination;

[0017] When the spray bar array operates in a normal spraying mode, the pneumatic valves are sequentially controlled in the order of N1, N2, N3...Nn-1, Nn from the outlet to the inlet of the spraying process to put the required number m of spray bar arrays in the spraying condition;

[0018] When the spray boom beam array operates in the interval spraying mode and n is an even number, the spray boom beams with odd numbers N1, N3, N5...Nn-1 are opened first, and then the spray boom beams with even numbers N2, N4, L6...Nn-2, Nn are opened in the order of opening, and the pneumatic valves are controlled in sequence from the outlet to the inlet of the spraying process to ensure that no less than the required number m of spray boom beams are in the spraying condition.

[0019] The interval spray mode is an optimization method of the normal spray mode. The optimization effect of the interval spray mode on reducing the probability of spray drip risk is calculated as follows:

[0020] Method A1: When m≤n / 2 and ≠1, if the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is

[0021]

[0022] The length of the risk area of ​​the spraying process in normal spraying mode is L act2 =LLact1 Formula 4:

[0023] Risk length ratio in normal spray mode

[0024]

[0025] If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is

[0026]

[0027] The length of the risk area of ​​the spraying process in the interval spraying mode is L act4 =LL act3 Formula 7;

[0028] Risk length ratio in interval spray mode

[0029]

[0030] The reduction in the probability of spray drop risk due to the interval spray mode is:

[0031]

[0032] From formula 4, we can know that ΔP1>0;

[0033] Method A2: When n / 2<m<n, if the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is

[0034]

[0035] The length of the risk area of ​​the spraying process in normal spraying mode is Lact6 = LL act5 Formula 11,

[0036] Risk length ratio in normal spray mode

[0037]

[0038] If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is

[0039]

[0040] The length of the risk area of ​​the spraying process in the interval spraying mode is

[0041] Lact8=LL act7 Formula 14;

[0042] Risk length ratio in interval spray mode

[0043]

[0044] The reduction in the probability of spray drop risk due to the interval spray mode is:

[0045]

[0046] From formula 16, we can know that ΔP2>0;

[0047] Method A3, when m = n; the length of the liquid spray section in the normal spray mode and the interval spray mode is

[0048] L act9 =∑Li=L1+L2+L3+....+Ln=L Formula 17;

[0049] When m=1: the length of the liquid spray section in the normal spray mode and the interval spray mode is

[0050] L act10 =L1 Formula 18;

[0051] Therefore, when m=n or m=1, the effect of the interval spraying mode is the same as that of the normal spraying mode, that is, the length of the risk area is the same.

[0052] In method A2, the boom beam N n-1 The location is close to the entrance of the spraying process, and the risk length ratio of the interval spraying mode is adopted

[0053] The calculation result of Formula 19 approaches zero, so it can be regarded as risk-free, that is, the strip surface can achieve an effect close to no spray drop marks.

[0054] In the spraying process, it is derived from formula 1 that

[0055]

[0056] The actual reaction time T after the strip contacts the liquid is calculated by formula 20. act , and use this value as the setting value to match the process parameters of subsequent processes.

[0057] The spraying process is a pickling process; squeeze rollers are provided at the outlet and inlet of the spraying process; the equipment of the spraying process includes a spray bar beam, a tension roller, a pinch roller, a pneumatic valve, a pipeline, a pressure transmitter, a flow transmitter, a centrifugal pump, a raw liquid tank, a PLC control device, and a transmission device;

[0058] The spray boom beam is provided with a plurality of nozzles for spraying liquid medicine medium onto the surface of the strip.

[0059] The tension roller is used to control the conveying speed of the strip during the spraying process.

[0060] The pinch roller is used to pinch and convey the strip and to squeeze out the residual liquid on the surface of the strip;

[0061] Pneumatic valves are used to control the on and off of the main pipeline or selected spray boom beam in the spray process.

[0062] The present invention can effectively improve the problem of strip spray drip marks and greatly improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0064] Attached Figure 1 It is a schematic diagram of the spraying process of the present invention;

[0065] In the figure: 1-spray beam; 2-pneumatic valve; 3-strip material. DETAILED DESCRIPTION

[0066] As shown in the figure, a method for improving the spray drip marks of strips is used for spraying liquid on strips in a spraying process, wherein the spraying process includes a spray bar beam array formed by more than one spray bar beam arranged in parallel, and the spray bar beam in the spray bar beam array in a spraying condition forms a liquid spraying section in the process to output liquid to the surface of the strip; the starting end of the liquid spraying section is located at the spray bar beam N1 closest to the spray outlet of the spray bar beam array, and the end is located at the spray bar beam Nn in the spraying condition closest to the spray inlet; the length of the liquid spraying section is related to the actual speed V of the strip passing through the spraying process act Matching; when the strip passes through the spraying process section, the strip part that needs to be sprayed receives the liquid spraying time reaching the specified liquid reaction time, and the liquid spraying section of the spraying process is closest to the entrance of the spraying process, so that the strip sent to the spraying process later can be sprayed as soon as possible to reduce the probability of being contaminated by dripping liquid before being sprayed.

[0067] In the spray bar beam array, the number of spray bar beams is n; the number of spray bar beams in the spraying working state is m, that is, the number of rows of spray bar beams opened in the spraying process;

[0068] Assume the length of the boom beam array is L, in meters;

[0069] The actual speed of the strip through the spraying process is V act , the unit is meter / min;

[0070] The specified liquid reaction time is Tref, in seconds;

[0071] The length of the strip part to be sprayed is Lref, in millimeters;

[0072] The relationship between the above parameters is expressed as follows in Formula 1:

[0073]

[0074] According to L ref The value of is compared with the cumulative distance from the spray process outlet to a single boom beam, and then the number of rows of open boom beams is inferred using Formula 2:

[0075]

[0076] Each spray bar beam is controlled by a pneumatic valve connected to it to determine whether the spray bar beam is in the spraying condition; the spray bar beam array works in the normal spraying mode or the interval spraying mode; in the spraying process, the strip conveying path outside the liquid spraying section is a risk area where there is no working spray bar beam above and there is a risk of liquid dripping, and the strip is prone to dripping defects due to liquid dripping contamination;

[0077] When the spray bar array operates in a normal spraying mode, the pneumatic valves are sequentially controlled in the order of N1, N2, N3...Nn-1, Nn from the outlet to the inlet of the spraying process to put the required number m of spray bar arrays in the spraying condition;

[0078] When the spray boom beam array operates in the interval spraying mode and n is an even number, the spray boom beams with odd numbers N1, N3, N5...Nn-1 are opened first, and then the spray boom beams with even numbers N2, N4, L6...Nn-2, Nn are opened in the order of opening, and the pneumatic valves are controlled in sequence from the outlet to the inlet of the spraying process to ensure that no less than the required number m of spray boom beams are in the spraying condition.

[0079] The interval spray mode is an optimization method of the normal spray mode. The optimization effect of the interval spray mode on reducing the probability of spray drip risk is calculated as follows:

[0080] Method A1: When m≤n / 2 and ≠1, if the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is

[0081]

[0082] The length of the risk area of ​​the spraying process in normal spraying mode is L act2 =LL act1 Formula 4: Risk length ratio in normal spray mode

[0083]

[0084] If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is

[0085]

[0086] The length of the risk area of ​​the spraying process in the interval spraying mode is L act4 =LL act3 Formula 7;

[0087] Risk length ratio in interval spray mode

[0088]

[0089] The reduction in the probability of spray drop risk due to the interval spray mode is:

[0090]

[0091] From formula 4, we can know that ΔP1>0;

[0092] Method A2: When n / 2<m<n, if the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is

[0093]

[0094] The length of the risk area of ​​the spraying process in normal spraying mode is Lact6 = LL act5 Formula 11,

[0095] Risk length ratio in normal spray mode

[0096]

[0097] If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is

[0098]

[0099] The length of the risk area of ​​the spraying process in the interval spraying mode is

[0100] Lact8=LL act7 Formula 14;

[0101] Risk length ratio in interval spray mode

[0102]

[0103] The reduction in the probability of spray drop risk due to the interval spray mode is:

[0104]

[0105] From formula 16, we can know that αP2>0;

[0106] Method A3, when m = n; the length of the liquid spray section in the normal spray mode and the interval spray mode is

[0107] L act9 =∑Li=L1+L2+L3+....+Ln=L Formula 17;

[0108] When m=1: the length of the liquid spray section in the normal spray mode and the interval spray mode is

[0109] L act10 =L1 Formula 18;

[0110] Therefore, when m=n or m=1, the effect of the interval spraying mode is the same as that of the normal spraying mode, that is, the length of the risk area is the same.

[0111] In method A2, the boom beam N n-1 The location is close to the entrance of the spraying process, and the risk length ratio of the interval spraying mode is adopted

[0112] The calculation result of Formula 19 approaches zero, so it can be regarded as risk-free, that is, the strip surface can achieve an effect close to no spray drop marks.

[0113] In the spraying process, it is derived from formula 1 that

[0114]

[0115] The actual reaction time T after the strip contacts the liquid is calculated by formula 20. act , and use this value as the setting value to match the process parameters of subsequent processes.

[0116] The spraying process is a pickling process; squeeze rollers are provided at the outlet and inlet of the spraying process; the equipment of the spraying process includes a spray bar beam, a tension roller, a pinch roller, a pneumatic valve, a pipeline, a pressure transmitter, a flow transmitter, a centrifugal pump, a raw liquid tank, a PLC control device, and a transmission device;

[0117] The spray boom beam is provided with a plurality of nozzles for spraying liquid medicine medium onto the surface of the strip.

[0118] The tension roller is used to control the conveying speed of the strip during the spraying process.

[0119] The pinch roller is used to pinch and convey the strip and to squeeze out the residual liquid on the surface of the strip;

[0120] Pneumatic valves are used to control the on and off of the main pipeline or selected spray boom beam in the spray process.

[0121] In this example, the PLC control device adopts Siemens 400 series or similar, which is used for logic calculation and control of the operation of the equipment, and the transmission device adopts Siemens S120 or G120 series to control the rotation of the motor;

[0122] In this example, the direction of each spray bar beam is perpendicular to the conveying direction of the strip, and the strip pickling liquid is sprayed vertically onto the surface of the strip.

[0123] From the calculation formula of this example, it can be known that since △P1 and △P2 are both greater than zero, the interval spray mode can reduce the risk length ratio compared with the normal spray mode. Therefore, after using the interval spray mode, the process parameters of the reaction time after the strip contacts the liquid can be met, and the surface quality of the strip can be guaranteed.

Claims

1. A method for improving the spray drip marks of a strip, which is used for the liquid spraying treatment of the strip in the spraying process, and is characterized by: The spraying process includes a spray bar beam array formed by arranging more than one spray bar beam in parallel, and the spray bar beam in the spray bar beam array in the spraying state forms a liquid spraying section in the process to output liquid to the surface of the strip; The start of the liquid spray section is located at the spray bar beam N1 closest to the spray outlet in the spray bar beam array, and the end is located at the spray bar beam Nn closest to the spray inlet and in the spray working condition; the length of the liquid spray section is related to the actual speed V of the strip passing through the spray process act Matching; when the strip passes through the spraying process section, the strip part that needs to be sprayed receives the liquid spraying time to reach the specified liquid reaction time, and the liquid spraying section of the spraying process is closest to the entrance of the spraying process, so that the strip sent to the spraying process later can receive the spraying as soon as possible, so as to reduce the probability of being contaminated by dripping liquid before receiving the spraying; In the spray bar beam array, the number of spray bar beams is n; the number of spray bar beams in the spraying working state is m, that is, the number of rows of spray bar beams opened in the spraying process; Assume the length of the boom beam array is L, in meters; The actual speed of the strip through the spraying process is V act , the unit is meter / min; The prescribed reaction time of the drug solution is Tref , unit is s; The length of the strip to be sprayed is Lref , in millimeters; The relationship between the above parameters is expressed as follows in Formula 1: Formula 1; according to The value of is compared with the cumulative distance from the spray process outlet to a single boom beam, and then the number of rows of open boom beams is inferred using Formula 2: Formula 2: Each spray bar beam is controlled by a pneumatic valve connected to it to determine whether the spray bar beam is in the spraying condition; the spray bar beam array works in the normal spraying mode or the interval spraying mode; in the spraying process, the strip conveying path outside the liquid spraying section is a risk area where there is no working spray bar beam above and there is a risk of liquid dripping, and the strip is prone to dripping defects due to liquid dripping contamination; When the spray bar array operates in a normal spraying mode, the pneumatic valves are sequentially controlled in the order of N1, N2, N3...Nn-1, Nn from the outlet to the inlet of the spraying process to put the required number m of spray bar arrays in the spraying condition; When the spray bar array operates in the interval spray mode and n is an even number, the spray bar beams with odd numbers N1, N3, N5...Nn-1 are opened first, and then the spray bar beams with even numbers N2, N4, L6...Nn-2, Nn are opened, and the pneumatic valves are controlled in sequence from the outlet to the inlet of the spraying process to put not less than the required number m of spray bar beams in the spraying condition; The interval spray mode is an optimization method of the normal spray mode. The optimization effect of the interval spray mode on reducing the probability of spray drip risk is calculated as follows: Method A1: When m≤n / 2 and ≠1, if the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is Formula 3: The length of the risk area of ​​the spraying process under normal spraying mode is L act2 =LL act1 Formula 4: Risk length ratio in normal spray mode Formula 5; If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is Formula 6; The length of the risk area of ​​the spraying process in the interval spraying mode is L act4 =LL act 3 Formula 7; Risk length ratio in interval spray mode Formula 8; The reduction in the probability of spray drop risk due to the interval spray mode is: Formula 9; From formula 4, we can know ; Method A2: n / 2<m<n When the spray bar beam array works in the normal spray mode, the length of the liquid spray section in the spray process is Formula 10, The length of the risk area of ​​the spraying process under normal spraying mode is Lact 6 =LL act5 Formula 11, Risk length ratio in normal spray mode Formula twelve; If the spray bar array works in the interval spray mode, the length of the liquid spray section in the spray process is L act7 = Formula XIII; The length of the risk area of ​​the spraying process in the interval spraying mode is Lact 8 =LL act7 Formula 14; Risk length ratio in interval spray mode Formula 15; The reduction in the probability of spray drop risk due to the interval spray mode is: Formula 16; From formula 16, we know ; Method A3: m=n The length of the liquid spray section in the normal spray mode and the interval spray mode is Formula XVII; when m=1 hour ： The length of the liquid spray section in the normal spray mode and the interval spray mode is L act10 =L1 Formula XVIII; Therefore, when m=n or m=1 When the interval spraying mode is used, the effect of the normal spraying mode is the same, that is, the length of the risk area is the same.

2. A method for improving strip spray drip marks according to claim 1, characterized in that: In method A2, the boom beam N n-1 The location is close to the entrance of the spraying process, and the risk length ratio of the interval spraying mode is adopted Formula 19; The calculation result of Formula 19 approaches zero, so it can be regarded as risk-free, that is, the strip surface can achieve an effect close to no spray drop marks.

3. A method for improving strip spray drip marks according to claim 1, characterized in that: In the spraying process, it is derived from formula 1 that Formula 20; The actual reaction time after the strip contacts the liquid is calculated by formula 20. T act , and use this value as the setting value to match the process parameters of subsequent processes.

4. A method for improving strip spray drip marks according to claim 1, characterized in that: The spraying process is a pickling process; squeeze rollers are provided at the outlet and inlet of the spraying process; the equipment of the spraying process includes a spray bar beam, a tension roller, a pinch roller, a pneumatic valve, a pipeline, a pressure transmitter, a flow transmitter, a centrifugal pump, a raw liquid tank, a PLC control device, and a transmission device; The spray bar beam is provided with a plurality of nozzles for spraying liquid medicine medium onto the surface of the strip; The tension roller is used to control the conveying speed of the strip during the spraying process; The pinch roller is used to pinch and convey the strip and to squeeze out the residual liquid on the surface of the strip; Pneumatic valves are used to control the on and off of the main pipeline or selected spray boom beam in the spray process.

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