Full-automatic nitrocotton drying method

Abstract

The full-automatic nitrocotton drying method comprises the following steps that S1, a sliding table is installed on an anti-explosion drying oven, nitrocotton and test paper are placed on the sliding table, and the sliding table is used for pushing the nitrocotton out of the anti-explosion drying oven and feeding the nitrocotton into the anti-explosion drying oven; s2, arranging a polarization camera system at the upper part of the inner side of the explosion-proof oven, wherein the polarization camera system shoots and identifies the color of the test paper; s3, a temperature sensor and an electric heating pipe are arranged on the inner wall of the anti-explosion drying oven; s4, an air blast system is arranged on the anti-explosion drying oven, and the air blast system adjusts the air volume according to the temperature distribution condition in the anti-explosion drying oven; and S5, arranging an early warning indication module on the explosion-proof oven, wherein the early warning indication module is used for sending out an alarm signal. The internal temperature of the explosion-proof drying oven can be accurately adjusted, the strict requirement of nitrocotton drying for the temperature is met, and the situation that the product quality is affected by temperature fluctuation is avoided.

Description

Technical Field

[0001] The invention relates to a drying method, in particular to a full-automatic drying method for nitrocellulose. Background Art

[0002] In the modern industrial system, nitrocellulose has become a vital chemical raw material due to its unique chemical and physical properties, playing an irreplaceable role in many fields. In the field of gunpowder manufacturing, nitrocellulose is a key ingredient, and its quality and degree of dryness directly determine the performance and safety of gunpowder. Nitrocellulose that has been precisely dried can make gunpowder have a stable burning rate and reliable explosion performance, providing a solid material foundation for national defense, military industry, civilian blasting and other industries. In coating production, the addition of nitrocellulose can significantly improve the film-forming property, glossiness and durability of the coating, allowing the coating to show excellent decorative and protective effects in architectural decoration, automotive painting and other fields. The drying treatment and quality inspection of nitrocellulose are key links in the production process.

[0003] The prior art also has the following problems:

[0004] 1. The temperature control accuracy of traditional ovens is limited, making it difficult to achieve precise temperature control during the drying process of nitrocellulose. In actual production, nitrocellulose is extremely sensitive to drying temperature. Excessive temperature may cause safety hazards, and excessive temperature fluctuations will affect the stability of product quality, resulting in significant quality differences between batches, making it difficult to meet the production requirements of nitrocellulose.

[0005] 2. In the process of nitrocellulose quality inspection, judging product quality by the color change of test paper is a common method. However, the traditional method of manual observation of the test paper color is highly subjective, and the judgment standards of different operators vary, resulting in a lack of accuracy and consistency in the test results. In addition, manual inspection is inefficient and cannot meet the inspection needs of large-scale production, which easily causes delays in production progress. Summary of the Invention

[0006] The main purpose of the present invention is to provide a fully automatic drying method for nitrocellulose, which can effectively solve the above-mentioned problems.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A fully automatic drying method for nitrocellulose comprises the following steps: S1, installing a slide on an explosion-proof oven, placing the nitrocellulose and a test paper on the slide, wherein the slide is used to push the nitrocellulose out of the explosion-proof oven and to put the nitrocellulose into the explosion-proof oven; S2, arranging a polarization camera system on the upper inner side of the explosion-proof oven, wherein the polarization camera system is used to photograph and identify the color of the test paper; S3, arranging a temperature sensor and an electric heating tube on the inner wall of the explosion-proof oven; S4, arranging an air blowing system on the explosion-proof oven, wherein the air blowing system adjusts the air volume according to the temperature distribution in the explosion-proof oven; and S5, arranging an early warning indicator module on the explosion-proof oven, wherein the early warning indicator module is used to issue an alarm signal.

[0009] Preferably, the internal temperature of the explosion-proof oven is controlled by a control system, and the specific control of the control system is precisely adjusted in the following manner:

[0010] First, set the temperature change function of the explosion-proof oven as T(t), and the temperature setting value as T set , the heating power is P(t), the heat dissipation coefficient of the explosion-proof oven is k (k>0), according to the law of conservation of heat, the temperature change calculation formula is as follows:

[0011]

[0012] Among them, m is the equivalent mass of air and materials in the explosion-proof oven, C is the specific heat capacity of the material in the explosion-proof oven, T env is the ambient temperature;

[0013] In order to achieve precise temperature control, the following control method is adopted: when T(t) <T set -ΔT, where ΔT is the lower limit of the allowable temperature fluctuation, ΔT>0, P(t)=P max , P max is the maximum power of the electric heating tube;

[0014] When T set -ΔT≤T(t)≤T set +ΔT, by solving the formula ax 2 +bx+c=0, where x=P(t), to determine the heating power P(t), the values of a, b, and c are based on the current temperature T(t), the temperature change rate And the deviation from the set temperature and other factors;

[0015] when b=β(T(t)-T set ), c=γ, α, β, γ are coefficients adjusted according to actual conditions. By solving this formula, the appropriate heating power P(t) is obtained to fine-tune the temperature in the explosion-proof oven; when T(t)>T setWhen +ΔT, P(t)=0;

[0016] The calculation steps are as follows:

[0017] Step 1: The temperature T(t) inside the explosion-proof oven is collected in real time by a temperature sensor, and samples are taken at a certain time interval Δt;

[0018] Step 2: Calculate the temperature change rate

[0019] Step 3: Determine T(t) and T set -ΔT, T set The magnitude relationship of +ΔT;

[0020] Step 4: If T(t) <T set -ΔT, let P(t)=P max ;

[0021] Step 5: If T set -ΔT≤T(t)≤T set +ΔT, according to the current T(t), Calculate the values of a, b, and c and substitute them into the formula ax 2 +bx+c=0, use the root-finding formula Solve and take the root that conforms to the actual physical meaning as the value of heating power P(t);

[0022] Step 6: T(t)>T set +ΔT, let P(t)=0;

[0023] Step 7: The calculated heating power P(t) value is transmitted to the control system to adjust the heating power of the electric heating tube to achieve precise control of the internal temperature of the explosion-proof oven.

[0024] Preferably, the polarization camera system calculates the color of the test paper as follows:

[0025] Convert the captured test paper image from RGB color space to HSV color space to obtain the hue H, saturation S and lightness V of the test paper color. Set the parameter of standard red in HSV space to H std 、S std 、V std , use the following formula to calculate the color difference value D:

[0026]

[0027] Among them, w1, w2, w3, and w4 are weight coefficients, and w1+w2+w3+w4=1. The weights are set according to the importance of color judgment.

[0028] The calculation steps are as follows:

[0029] Step 1: After the polarization camera system captures the test strip image, the software system converts the image from RGB color space to HSV color space to obtain the H, S, and V values of the test strip color.

[0030] Step 2: Compare the obtained H, S, and V values with the H of the standard red std 、S std 、V std Substitute the value into the above formula;

[0031] Step 3: Calculate (H+H std ) 2 、(S+S std ) 2 、(V+V std ) 2 as well as

[0032]

[0033] Step 4: Multiply the above calculation results by the corresponding weight coefficients w1, w2, w3, and w4 respectively;

[0034] Step 5: Add the product results;

[0035] Step 6: Take the square root of the sum to get the color difference value D;

[0036] Step 7: Use the software system to compare the calculated D value with the set threshold D th For comparison, when D <D th When the test paper color reaches the red color required by the process, a signal is sent to the control system to trigger subsequent operations.

[0037] Preferably, the blast system includes a high-temperature resistant blower and an air duct, both ends of the air duct are connected to the interior of the explosion-proof oven; the air volume control of the blast system adopts the following calculation formula:

[0038] Assume that the speed of the high-temperature blower is n(t), the air volume is Q(t), and the wind resistance coefficient of the air duct is R. According to the principles of fluid mechanics, the relationship between air volume and speed satisfies the calculation formula: Where K is the conversion coefficient between the speed and air volume of the high temperature resistant blower, C f is the flow coefficient of the air duct; in order to make the temperature in the explosion-proof oven uniform, the air volume is adjusted according to the temperature distribution in the explosion-proof oven. When the temperature distribution in the explosion-proof oven is uneven, the appropriate motor speed n(t) is determined by solving the formula, and the temperature unevenness is set to ΔT dist , define the calculation formula An 2 (t) + Bn(t) + C = 0, where C=γ1α1, β1, γ1 are coefficients adjusted according to actual conditions;

[0039] The calculation steps are as follows:

[0040] Step 1: Use temperature sensors to collect the temperature at different locations in the explosion-proof oven and calculate the temperature unevenness, ΔT dist =max(T i )-min(T i ), where T i is the temperature at each location;

[0041] Step 2: Calculate the coefficients A, B, and C of the formula;

[0042] Step 3: Use the root-finding formula Solve and take the root that conforms to the actual physical meaning as the appropriate speed n(t);

[0043] Step 4: Convert the speed n(t) into a control signal and send it to the high-temperature resistant blower to adjust the motor speed of the high-temperature resistant blower, thereby adjusting the air volume.

[0044] Preferably, the slide includes a cylinder, a telescopic rail, a position sensor and a material mesh plate, wherein two telescopic rails are symmetrically fixedly connected on both sides of the explosion-proof oven, the material mesh plate is fixedly connected between the two telescopic rails, one side of the material mesh plate is fixedly connected to the door wall of the oven door, and the position sensor is installed on the material mesh plate; the lens of the polarization camera system faces the material mesh plate, and is used to photograph the test paper on the material mesh plate; the polarization camera system transmits the photographed image information to the computer, photographs the test paper placed on the material mesh plate inside the explosion-proof oven every 1 minute, and transmits the image information to the software system; the software system receives the image data from the polarization camera system, converts the image from the RGB color space to the HSV color space, and uses a formula to calculate the difference between the test paper color and the standard color to determine whether the material is qualified, and feeds back the result to the control system.

[0045] Preferably, the motion control of the material screen in the slide adopts the following calculation formula:

[0046] Assume that the displacement of the material screen is x(t), the velocity is v(t), the acceleration is a(t), the driving force is F(t), and the mass of the material screen is m s , the friction coefficient is μ, according to Newton's second law, m s a(t)=F(t)-μm s g, where g is the acceleration due to gravity; the relationship between velocity and displacement satisfies The relationship between acceleration and velocity satisfies

[0047] In the process of material screen movement, in order to achieve accurate positioning, according to the target position x target Adjust the driving force F(t) with the current position x(t). When approaching the target position, adjust the driving force and set Where L is the maximum stroke of the material screen, then F(t) = F0cos(θ), and F0 is the initial driving force;

[0048] The calculation steps are as follows:

[0049] Step 1: The position sensor collects the current position x(t) of the material screen in real time;

[0050] Step 2: Calculation

[0051] Step 3: Calculate the driving force F(t) = F0cos(θ) based on θ;

[0052] Step 4: Convert the driving force F(t) into a control signal and send it to the control system. The control system controls the extension and contraction of the cylinder, thereby driving the material screen to move.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. The present invention adopts a temperature control algorithm based on the law of conservation of heat, collects temperature in real time through a temperature sensor, and determines the heating power in combination with a corresponding calculation method. It can achieve precise adjustment of the internal temperature of the explosion-proof oven, meet the strict temperature requirements of nitrocellulose drying, and avoid the impact of temperature fluctuations on product quality. The electric heating tube is arranged on the inner wall of the explosion-proof oven, and the blast system cooperates with the air duct to circulate the hot air evenly, so that the hot air in the explosion-proof oven is evenly distributed, ensuring that the nitrocellulose is heated evenly and improving the drying effect.

[0055] 2. In the present invention, the polarization camera system takes a photo of the test strip every 1 minute, and the software system converts the image from the RGB color space to the HSV color space for color recognition. The recognition accuracy is high, and it can quickly and accurately determine whether the material is qualified, discover quality problems in time, and greatly improve the efficiency of detection, which can meet the detection needs of large-scale production.

[0056] 3. During the detection process, the software system of the present invention can automatically send signals to the control system according to the color change of the test paper to control the heating of the explosion-proof oven and the opening and closing of the oven door, thereby realizing an automated detection process, improving production efficiency and reducing manual intervention.

[0057] 4. Issue an alarm through the early warning indication module to ensure the safety of equipment and personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1A schematic diagram of the overall structure of the oven used in the present invention;

[0059] Figure 2 A schematic structural diagram of the oven used in the present invention from another perspective;

[0060] Figure 3 A connection block diagram of the control system in the oven used in the present invention;

[0061] Figure 4 The figure is a flow chart of the fully automatic drying of nitrocellulose of the present invention.

[0062] As shown in the figure: 1. Explosion-proof oven; 101. Channel steel load-bearing feet; 2. Oven door; 3. Slide; 31. Cylinder; 32. Telescopic rail; 33. Position sensor; 34. Material screen; 4. Polarization camera system; 5. Control system; 6. Computer; 7. Printer; 8. Software system; 13. Temperature sensor; 14. Electric heating tube; 15. Safety protection system; 16. Mobile control panel; 17. Blowing system; 171. High-temperature resistant blower; 172. Air duct; 18. Early warning indication module; 19. Wireless communication module; 20. Insulation layer. DETAILED DESCRIPTION

[0063] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0064] Example 1

[0065] like Figure 1 、 Figure 2 and Figure 3 As shown, the oven used in the present invention includes an explosion-proof oven 1, a control system 5, a computer 6, a printer 7 and a software system 8. An opening is provided on one side of the explosion-proof oven 1, and an oven door 2 is provided on the explosion-proof oven 1 corresponding to the opening; a slide 3 is installed on the explosion-proof oven 1, and the oven door 2 is installed on the slide 3. The slide 3 is used to place nitrocellulose and test paper, and the slide 3 is used to push the nitrocellulose out of the explosion-proof oven 1 and to put the nitrocellulose into the explosion-proof oven 1; a polarization camera system 4 is provided on the upper inner side of the explosion-proof oven 1, and the polarization camera system 4 is used to photograph and identify the color of the test paper; a temperature sensor 13 is installed on the inner wall of the explosion-proof oven 1, and an electric heating tube 14 is installed on the inner wall of the explosion-proof oven 1; an air blowing system 17 is installed on the explosion-proof oven 1, and the air blowing system 17 adjusts the air volume according to the temperature distribution in the explosion-proof oven 1; an early warning indication module 18 is installed on the explosion-proof oven 1, and the early warning indication module 18 is used to issue an alarm signal.

[0066] Please continue to see Figure 4 The fully automatic drying method of nitrocellulose of the present invention comprises the following steps:

[0067] S1. Install a slide 3 on the explosion-proof oven 1, place the nitrocellulose and test paper on the slide 3, and the slide 3 is used to push the nitrocellulose out of the explosion-proof oven 1 and put the nitrocellulose into the explosion-proof oven 1;

[0068] S2, setting a polarization camera system 4 on the upper inner side of the explosion-proof oven 1, and the polarization camera system 4 is used to capture the color of the identification test paper;

[0069] S3, setting a temperature sensor 13 and an electric heating tube 14 on the inner wall of the explosion-proof oven 1;

[0070] S4, setting an air blowing system 17 on the explosion-proof oven 1, and adjusting the air volume according to the temperature distribution in the explosion-proof oven 1;

[0071] S5. An early warning indicator module 18 is provided on the explosion-proof oven 1. The early warning indicator module 18 is used to send out an alarm signal.

[0072] Furthermore, the slide 3 includes a cylinder 31, a telescopic rail 32, a position sensor 33 and a material mesh plate 34. The telescopic rail 32 is located on both sides of the explosion-proof oven 1 and is symmetrically fixedly connected. The material mesh plate 34 is fixedly connected between the two telescopic rails 32. One side of the material mesh plate 34 is fixedly connected to the door wall of the oven door 2. The position sensor 33 is installed on the material mesh plate 34. The four corners of the bottom of the explosion-proof oven 1 are fixedly connected with channel steel bearing feet 101.

[0073] Furthermore, the lens of the polarization camera system 4 is directed toward the material mesh plate 34, and is used to photograph the test paper on the material mesh plate 34. The polarization camera system 4 is used to transmit the photographed image information to the computer 6, and photograph the test paper placed on the material mesh plate 34 inside the explosion-proof oven 1 every 1 minute, and transmit the image information to the software system 8. The software system 8 is installed in the computer 6. The software system 8 receives the image data from the polarization camera system 4, processes and analyzes it, and the software system 8 converts the image from the RGB color space to the HSV color space, and uses the formula to calculate the difference between the test paper color and the standard color to determine whether the material is qualified, and feeds the result back to the control system 5.

[0074] Furthermore, the computer 6 is used for data processing, analysis and storage, and the software system 8 is used to record product information and production process data, including temperature change curves, heating time, and test paper color change time. When these data need to be output, the software system 8 sends instructions to the computer 6, and the computer 6 is connected to the printer 7 via a data cable. The relevant data and reports are printed out by the printer 7 to facilitate production records and management.

[0075] Furthermore, the blowing system 17 includes a high-temperature resistant blower 171 and an air duct 172. Both ends of the air duct 172 are connected to the interior of the explosion-proof oven 1. The high-temperature resistant blower 171 is installed on the outer box wall of the explosion-proof oven 1. The air inlet and outlet ends of the high-temperature resistant blower 171 are respectively connected to the air duct 172, and the high-temperature resistant blower 171 is used to circulate air into the explosion-proof oven 1.

[0076] Furthermore, it includes a mobile control panel 16, on which a wireless communication module 19 is provided. The mobile control panel 16 is connected to the control system 5 via the wireless communication module 19, so that remote operation and monitoring can be achieved.

[0077] Furthermore, the electric heating tubes 14 are evenly distributed around the inner side of the explosion-proof oven 1, and the blowing system 17 cooperates with the air duct 172 to evenly circulate the hot air into the interior of the explosion-proof oven 1, so that the hot air in the explosion-proof oven 1 is evenly distributed, thereby improving the heating efficiency and temperature uniformity; the inner and outer walls of the explosion-proof oven 1 are filled with a layer of insulation layer 20, and the insulation layer 20 is made of high-temperature resistant aluminum silicate fiber. The thickness of the insulation layer 20 is 100 mm, which effectively reduces heat loss and reduces energy consumption.

[0078] Furthermore, the working modes of the oven of the present invention include system automatic mode, system teaching programming mode and equipment system manual mode; in automatic mode, the equipment automatically operates according to the preset program to complete the material drying and testing process; the teaching programming mode is used for process debugging of new products, and the operator records the actions and parameters by manually operating the equipment to generate the corresponding operating program; in manual mode, the operator manually inputs product process information through the mobile control panel 16 or local operation buttons to control the operation of each component of the equipment.

[0079] As a preferred embodiment, the software system 8 is designed based on the SQLSERVER database for web page design, adopts a modular design, and has data recording, storage, analysis and visual display functions; it can automatically record product information and process data during product processing, including temperature change curves, heating time, and test paper color change time; it is connected to the factory database through the network to achieve data sharing; production information is displayed on the workshop display screen in the form of charts, reports, etc., which is convenient for management personnel to monitor and arrange production.

[0080] As a preferred embodiment, the mobile control panel 16 is provided with a touch screen and operation buttons, and the touch screen is used to view the operating status of the fully automatic oven in real time, including the temperature inside the explosion-proof oven 1, the position of the slide 3 and the status of the oven door 2; at the same time, the system parameters can be set, including the internal temperature setting value of the explosion-proof oven 1, the insulation time, and the heating power limit; the operation buttons can be used to start, stop, and manually control the operation of the slide 3 and the oven door 2 of the equipment. An external emergency stop button is provided on the mobile control panel 16 for immediately stopping the operation of the fully automatic oven in an emergency.

[0081] As a preferred embodiment, the software system 8 is installed in the computer 6 and is used to record product information and production process data, such as temperature change curve, heating time, test paper color change time, etc. The software system 8 is based on the SQLSERVER database for web design and adopts a modular design. It has data recording, storage, analysis and visualization functions. It can be connected to the factory database through the network to realize data sharing, and the production information can be displayed on the workshop display screen in the form of charts, reports, etc., which is convenient for management personnel to monitor and arrange production. When data needs to be output, the software system 8 sends an instruction to the computer 6, and the computer 6 connects to the printer 7 to print relevant data and reports.

[0082] As a preferred embodiment, the slide 3, polarization camera system 4, computer 6, temperature sensor 13, electric heating tube 14, safety protection system 15 and blowing system 17 are all electrically connected to the control system 5, the early warning indication module 18 is electrically connected to the safety protection system 15, the mobile control panel 16 is electrically connected to the wireless communication module 19, the wireless communication module 19 is wirelessly connected to the computer 6, and the printer 7 is electrically connected to the computer 6.

[0083] As a preferred embodiment, the nitrocellulose and test paper to be dried are placed on the material mesh plate 34 of the slide 3. Driven by the cylinder 31, the slide 3 sends the material mesh plate 34 into the explosion-proof oven 1. The oven door 2 is closed. At this time, the electric heater 14 starts to work, the blowing system 17 is started, and the high-temperature resistant blower 171 drives the air to circulate through the air duct 172 into the explosion-proof oven 1, so that the hot air circulates evenly in the explosion-proof oven 1 to dry the nitrocellulose.

[0084] As a preferred embodiment, the polarization camera system 4 takes a photo of the test paper every 1 minute, and the software system 8 processes and analyzes the image to determine whether the material is qualified. If qualified, the software system 8 sends a signal to the control system 5 to control the electric heating tube 14 in the explosion-proof oven 1 to stop heating, and open the oven door 2, and the cylinder 31 pushes the material screen 34 out of the explosion-proof oven 1; if unqualified, continue drying and testing.

[0085] As a preferred embodiment, the computer 6 processes, analyzes and stores the data of the entire production process (such as temperature change curve, heating time, test paper color change time, etc.), and the software system 8 displays these data in the form of charts, reports, etc. on the workshop display screen to facilitate management personnel to monitor production. When data needs to be output, the software system 8 sends instructions to the computer 6, and the computer 6 controls the printer 7 to print relevant data and reports.

[0086] Example 2

[0087] Further, based on the first embodiment, in order to realize the purpose of accurately controlling the internal temperature of the explosion-proof oven 1 by the control system 5, refer to Figure 1 、 Figure 2 and Figure 3 The internal temperature of the explosion-proof oven 1 is controlled by the control system 5. The specific control of the control system 5 is precisely adjusted in the following manner:

[0088] First, set the temperature change function of the explosion-proof oven 1 over time as T(t), and the temperature setting value is T set , the heating power is P(t), the heat dissipation coefficient of the explosion-proof oven 1 is k, k>0, according to the law of conservation of heat, the temperature change is calculated as follows:

[0089]

[0090] Wherein, m is the equivalent mass of air and material in the explosion-proof oven 1, C is the specific heat capacity of the material in the explosion-proof oven 1, T env is the ambient temperature;

[0091] In order to achieve precise temperature control, the following control method is adopted: when T(t) <T set -ΔT, where ΔT is the lower limit of the allowable temperature fluctuation, ΔT>0, P(t)=P max , P max is the maximum power of the electric heating tube 14;

[0092] When T set -ΔT≤T(t)≤T set +ΔT, by solving the formula ax 2 +bx+c=0, where x=P(t), to determine the heating power P(t), the values of a, b, and c are based on the current temperature T(t), the temperature change rate And the deviation from the set temperature and other factors;

[0093] when b=β(T(t)-T set), c=γ, α, β, γ are coefficients adjusted according to actual conditions. By solving this formula, the appropriate heating power P(t) is obtained to fine-tune the temperature in the explosion-proof oven 1; when T(t)>T set When +ΔT, P(t)=0;

[0094] The calculation steps are as follows:

[0095] Step 1: The temperature T(t) inside the explosion-proof oven 1 is collected in real time by the temperature sensor 13 and sampled at a certain time interval Δt;

[0096] Step 2: Calculate the temperature change rate

[0097] Step 3: Determine T(t) and T set -ΔT, T set The magnitude relationship of +ΔT;

[0098] Step 4: If T(t) <T set -ΔT, let P(t)=P max ;

[0099] Step 5: If T set -ΔT≤T(t)≤T set +ΔT, according to the current T(t), Calculate the values of a, b, and c and substitute them into the formula ax 2 +bx+c=0, use the root-finding formula Solve, take the root that conforms to the actual physical meaning as the value of the heating power P(t). For example, the power cannot be negative. If there is a negative root between the two roots, discard it.

[0100] Step 6: T(t)>T set +ΔT, let P(t)=0;

[0101] Step 7: The calculated heating power P(t) value is transmitted to the control system 5 , and the heating power of the electric heating tube 14 is adjusted to achieve precise control of the internal temperature of the explosion-proof oven 1 .

[0102] Example 3

[0103] Further, based on the second embodiment, in order to achieve the purpose of accurately obtaining and identifying the color of the test paper by the polarization camera system 4, refer to Figure 1 、 Figure 2 and Figure 3 The calculation method of the polarization camera system 4 for identifying the color of the test paper is as follows:

[0104] Convert the captured test paper image from RGB color space to HSV color space to obtain the hue H, saturation S and lightness V of the test paper color. Set the parameter of standard red in HSV space to Hstd 、S std 、V std , use the following formula to calculate the color difference value D:

[0105]

[0106] Among them, w1, w2, w3, and w4 are weight coefficients, and w1+w2+w3+w4=1. The weights are set according to the importance of color judgment, for example, w1=0.4, w1=0.2, w1=0.2, w1=0.2;

[0107] The calculation steps are as follows:

[0108] Step 1: After the polarization camera system 4 captures the test paper image, the software system 8 converts the image from the RGB color space to the HSV color space to obtain the H, S, and V values of the test paper color.

[0109] Step 2: Compare the obtained H, S, and V values with the H of the standard red std 、S std 、V std Substitute the value into the above formula;

[0110] Step 3: Calculate (H+H std ) 2 、(S+S std ) 2 、(V+V std ) 2 as well as

[0111]

[0112] Step 4: Multiply the above calculation results by the corresponding weight coefficients w1, w2, w3, and w4 respectively;

[0113] Step 5: Add the product results;

[0114] Step 6: Take the square root of the sum to get the color difference value D;

[0115] Step 7: Compare the calculated D value with the set threshold D through the software system 8 th For comparison, when D <D th When the test paper color reaches the red color required by the process, a signal is sent to the control system 5 to trigger subsequent operations, including controlling the explosion-proof oven 1 to stop heating and opening the oven door 2.

[0116] Example 4

[0117] Further, based on the third embodiment, in order to achieve the purpose of accurately controlling the air volume of the blowing system 17, refer to Figure 1 、 Figure 2and Figure 3 , the air volume control of the blast system 17 adopts the following calculation formula:

[0118] Assuming the speed of the high-temperature resistant blower 171 to be n(t), the air volume to be Q(t), and the drag coefficient of the air duct 172 to be R, according to the principles of fluid mechanics, the relationship between the air volume and the speed satisfies the calculation formula: Where K is the conversion coefficient between the speed and air volume of the high temperature resistant blower 171, C f is the flow coefficient of the air duct 172; in order to make the temperature in the explosion-proof oven 1 uniform, the air volume is adjusted according to the temperature distribution in the explosion-proof oven 1. When the temperature distribution in the explosion-proof oven 1 is uneven, the appropriate motor speed n(t) is determined by solving the formula, and the temperature unevenness is set to ΔT dist , define the calculation formula An 2 (t) + Bn(t) + C = 0, where C=γ1α1, β1, γ1 are coefficients adjusted according to actual conditions;

[0119] The calculation steps are as follows:

[0120] Step 1: Use the temperature sensor 13 to collect the temperature at different locations in the explosion-proof oven 1 and calculate the temperature unevenness, ΔT dist =max(T i )-min(T i ), where T i is the temperature at each location;

[0121] Step 2: Calculate the coefficients A, B, and C of the formula;

[0122] Step 3: Use the root-finding formula Solve and take the root that conforms to the actual physical meaning (the speed of the high temperature resistant blower 171 cannot be negative) as the appropriate speed n(t);

[0123] Step 4: Convert the rotation speed n(t) into a control signal and send it to the high temperature resistant blower 171 to adjust the motor speed of the high temperature resistant blower 171, thereby adjusting the air volume.

[0124] Example 5

[0125] Further, based on the fourth embodiment, in order to achieve the purpose of accurately controlling the movement displacement of the material screen 34 in the slide 3, refer to Figure 1 、 Figure 2 and Figure 3 The motion control of the material screen 34 in the slide 3 adopts the following calculation formula:

[0126] Assume that the displacement of the material screen 34 is x(t), the velocity is v(t), the acceleration is a(t), the driving force is F(t), and the mass of the material screen 34 is ms , the friction coefficient is μ, according to Newton's second law, m s a(t)=F(t)-μm s g, where g is the acceleration due to gravity; the relationship between velocity and displacement satisfies The relationship between acceleration and velocity satisfies

[0127] During the movement of the material screen 34, in order to achieve accurate positioning, it is necessary to target Adjust the driving force F(t) with the current position x(t). When approaching the target position, adjust the driving force and set Where L is the maximum stroke of the material screen 34, then F(t) = F0cos(θ), and F0 is the initial driving force;

[0128] The calculation steps are as follows:

[0129] Step 1: The position sensor 33 collects the current position x(t) of the material screen 34 in real time;

[0130] Step 2: Calculation

[0131] Step 3: Calculate the driving force F(t) = F0cos(θ) based on θ;

[0132] Step 4: Convert the driving force F(t) into a control signal and send it to the control system 5 . The control system 5 controls the cylinder 31 to extend and retract, thereby driving the material screen 34 to move.

[0133] Example 6

[0134] Further, on the basis of Example 5, in order to realize the purpose of leakage protection, line protection, short circuit protection, overload protection and over-temperature protection of the circuit of the full-automatic oven, refer to Figure 1 、 Figure 2 and Figure 3 The explosion-proof oven 1 is provided with a safety protection system 15, which includes leakage protection, line protection, short circuit protection, overload protection and over-temperature protection. When the safety protection system 15 detects an abnormality, leakage, short circuit, overload or temperature exceeding the set safety threshold, the safety protection system 15 immediately operates to cut off the relevant circuit, and at the same time the early warning indication module 18 sends a corresponding alarm signal to notify the operator to handle it;

[0135] The response time of the security protection system 15 is predicted using the following calculation formula:

[0136] Set the abnormal signal strength to S and the response time to t r , the response characteristic calculation formula of the safety protection system 15 is: Where a, b, and c are coefficients related to the hardware characteristics of the security protection system 15;

[0137] The calculation steps are as follows:

[0138] Step 1: Real-time monitoring of abnormal signal strength S;

[0139] Step 2: Determine coefficients a, b, and c based on the hardware characteristics of the security protection system 15;

[0140] Step 3: Use the formula Solve and take the root response time that conforms to the actual physical meaning and cannot be negative as the predicted response time t r ;

[0141] Step 4: If the predicted response time t r Exceeds the set maximum allowable response time t max , the software system 8 issues a further alarm to remind the operator to take emergency measures.

[0142] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fully automatic drying method for nitrocellulose, characterized in that: The steps include: S1. Installing a slide (3) on the explosion-proof oven (1), placing nitrocellulose and test paper on the slide (3), wherein the slide (3) is used to push the nitrocellulose out of the explosion-proof oven (1) and to put the nitrocellulose into the explosion-proof oven (1); S2, arranging a polarization camera system (4) on the upper inner side of the explosion-proof oven (1), wherein the polarization camera system (4) is used to photograph and identify the color of the test paper; S3, arranging a temperature sensor (13) and an electric heating tube (14) on the inner wall of the explosion-proof oven (1); S4, arranging an air blast system (17) on the explosion-proof oven (1), wherein the air blast system (17) adjusts the air volume according to the temperature distribution in the explosion-proof oven (1); S5. An early warning indication module (18) is provided on the explosion-proof oven (1), wherein the early warning indication module (18) is used to issue an alarm signal.

2. The fully automatic drying method for nitrocellulose according to claim 1, characterized in that: The internal temperature of the explosion-proof oven (1) is controlled by a control system (5), and the specific control of the control system (5) is precisely regulated in the following manner: First, the temperature variation function of the explosion-proof oven (1) over time is set to T(t), and the temperature setting value is T set , the heating power is P(t), the heat dissipation coefficient of the explosion-proof oven (1) is k (k>0), and according to the law of conservation of heat, the temperature change is calculated as follows: Wherein, m is the equivalent mass of air and material in the explosion-proof oven (1), C is the specific heat capacity of the material in the explosion-proof oven (1), T env is the ambient temperature; In order to achieve precise temperature control, the following control method is adopted: when T(t) <T set -ΔT, where ΔT is the lower limit of the allowable temperature fluctuation, ΔT>0, P(t)=P max , P max is the maximum power of the electric heating tube (14); When T set -ΔT≤T(t)≤T set +ΔT, by solving the formula ax 2 +bx+c=0, where x=P(t), to determine the heating power P(t), the values of a, b, and c are based on the current temperature T(t), the temperature change rate And the deviation from the set temperature and other factors; when b=β(T(t)-T set ), c=γ, α, β, γ are coefficients adjusted according to actual conditions. By solving this formula, the appropriate heating power P(t) is obtained to fine-tune the temperature in the explosion-proof oven (1); when T(t)>T set When +ΔT, P(t)=0; The calculation steps are as follows: Step 1: The temperature T(t) in the explosion-proof oven (1) is collected in real time by a temperature sensor (13), and sampling is performed at a certain time interval Δt; Step 2: Calculate the temperature change rate Step 3: Determine T(t) and T set -ΔT, T set The magnitude relationship of +ΔT; Step 4: If T(t) <T set -ΔT, let P(t)=P max ; Step 5: If T set -ΔT≤T(t)≤T set +ΔT, according to the current T(t), Calculate the values of a, b, and c and substitute them into the formula ax 2 +bx+c=0, use the root-finding formula Solve and take the root that conforms to the actual physical meaning as the value of heating power P(t); Step 6: T(t)>T set +ΔT, let P(t)=0; Step 7: The calculated heating power P(t) value is transmitted to the control system (5), and the heating power of the electric heating tube (14) is adjusted to achieve precise control of the internal temperature of the explosion-proof oven (1).

3. The fully automatic drying method for nitrocellulose according to claim 1, characterized in that: The calculation method of the polarization camera system (4) for identifying the color of the test paper is as follows: Convert the captured test paper image from RGB color space to HSV color space to obtain the hue H, saturation S and lightness V of the test paper color. Set the parameter of standard red in HSV space to H std 、S std 、V std , use the following formula to calculate the color difference value D: Among them, w1, w2, w3, and w4 are weight coefficients, and w1+w2+w3+w4=1. The weights are set according to the importance of color judgment. The calculation steps are as follows: Step 1: The polarization camera system (4) captures the test paper image and sends it to the software system (8). The software system (8) converts the image from the RGB color space to the HSV color space to obtain the H, S, and V values of the test paper color. Step 2: Compare the obtained H, S, and V values with the H of the standard red std 、S std 、V std Substitute the value into the above formula; Step 3: Calculate (H+H std ) 2 、(S+S std ) 2 、(V+V std ) 2 as well as Step 4: Multiply the above calculation results by the corresponding weight coefficients w1, w2, w3, and w4 respectively; Step 5: Add the product results; Step 6: Take the square root of the sum to get the color difference value D; Step 7: Compare the calculated D value with the set threshold D through the software system (8) th For comparison, when D <D th When the color of the test paper reaches the red color required by the process, a signal is sent to the control system (5) to trigger subsequent operations.

4. The fully automatic drying method for nitrocellulose according to claim 1, characterized in that: The blast system (17) includes a high-temperature resistant blower (171) and an air duct (172), both ends of the air duct (172) being connected to the interior of the explosion-proof oven (1); the air volume of the blast system (17) is controlled by the following calculation formula: Assuming the rotation speed of the high temperature resistant blower (171) to be n(t), the air volume to be Q(t), and the wind resistance coefficient of the air duct (172) to be R, according to the principles of fluid mechanics, the relationship between the air volume and the rotation speed satisfies the calculation formula: Where K is the conversion coefficient between the rotation speed and air volume of the high temperature resistant blower (171), C f is the flow coefficient of the air duct (172); in order to make the temperature in the explosion-proof oven (1) uniform, the air volume is adjusted according to the temperature distribution in the explosion-proof oven (1); when the temperature distribution in the explosion-proof oven (1) is uneven, the appropriate motor speed n(t) is determined by solving the formula, and the temperature unevenness is set to ΔT dist , define the calculation formula An 2 (t) + Bn(t) + C = 0, where C = γ1 (α1, β1, γ1 are coefficients adjusted according to actual conditions); The calculation steps are as follows: Step 1: Use the temperature sensor (13) to collect the temperature at different locations in the explosion-proof oven (1) and calculate the temperature unevenness, ΔT dist =max(T i )-min(T i ), where T i is the temperature at each location; Step 2: Calculate the coefficients A, B, and C of the formula; Step 3: Use the root-finding formula Solve and take the root that conforms to the actual physical meaning as the appropriate speed n(t); Step 4: Convert the rotation speed n(t) into a control signal and send it to the high temperature resistant blower (171), adjust the motor speed of the high temperature resistant blower (171), and thus adjust the air volume.

5. The fully automatic drying method for nitrocellulose according to claim 1, characterized in that: The slide (3) comprises a cylinder (31), a telescopic rail (32), a position sensor (33) and a material mesh plate (34); the telescopic rail (32) is located on both sides of the explosion-proof oven (1) and is symmetrically fixedly connected; the material mesh plate (34) is fixedly connected between the two telescopic rails (32); one side of the material mesh plate (34) is fixedly connected to the door wall of the oven door (2); and the position sensor (33) is mounted on the material mesh plate (34); The lens of the polarization camera system (4) is directed toward the material screen (34) and is used to photograph the test paper on the material screen (34). The polarization camera system (4) transmits the photographed image information to a computer (6), photographs the test paper placed on the material screen (34) inside the explosion-proof oven (1) every 1 minute, and transmits the image information to a software system (8). The software system (8) receives the image data from the polarization camera system (4), converts the image from the RGB color space to the HSV color space, calculates the difference between the color of the test paper and the standard color using a formula, thereby judging whether the material is qualified, and feeds the result back to the control system (5).

6. The fully automatic drying method for nitrocellulose according to claim 5, characterized in that: The motion control of the material screen (34) in the slide (3) adopts the following calculation formula: Assume that the displacement of the material screen (34) is x(t), the velocity is v(t), the acceleration is a(t), the driving force is F(t), and the mass of the material screen (34) is m s , the friction coefficient is μ, according to Newton's second law, m s a(t)=F(t)-μm s g, where g is the acceleration due to gravity; the relationship between velocity and displacement satisfies The relationship between acceleration and velocity satisfies During the movement of the material screen (34), in order to achieve accurate positioning, according to the target position x target Adjust the driving force F(t) with the current position x(t). When approaching the target position, adjust the driving force and set Where L is the maximum stroke of the material screen (34), then F(t) = F0cos(θ), F0 is the initial driving force; The calculation steps are as follows: Step 1: The position sensor (33) collects the current position x(t) of the material screen (34) in real time; Step 2: Calculation Step 3: Calculate the driving force F(t) = F0cos(θ) based on θ; Step 4: Convert the driving force F(t) into a control signal and send it to the control system (5). The control system (5) controls the cylinder (31) to extend and retract, thereby driving the material screen (34) to move.

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