Automatic cleaning method and system based on compressed air timing purging and used for thin-winding photoelectric sensor

Abstract

The invention relates to an automatic cleaning method and system for a thin-complex photoelectric sensor based on compressed air timing purging. The method comprises the steps that the compressed air injection period T is set, wherein T is larger than or equal to 1 min and smaller than or equal to 60 min; the light transmittance of the sensor is monitored in real time, and a trigger signal is generated when a decline value delta phi is larger than or equal to 10%; the opening time t (0.3 s < = t < = 0.5 s) of the electromagnetic valve is controlled in response to timing or triggering signals; compressed air is accelerated to be larger than or equal to 120 m / s through a Venturi structure nozzle and then is directionally jetted at an inclination angle of 15 degrees; a cleaning event is recorded and a light transmittance recovery status is verified. The system comprises an air source unit, a control unit, an execution unit and a safety interlocking unit, non-stop automatic cleaning is achieved, the failure rate of a sensor is reduced by 62%, and the nep misjudgment rate is reduced to 2.1%.

Description

Technical Field

[0001] This invention relates to the field of textile machinery maintenance, and in particular to an automatic cleaning method and system for fine-network photoelectric sensors based on timed compressed air blowing. Background Technology

[0002] In textile industry fine-tuning equipment, photoelectric sensors (such as yarn speed meters and yarn break detectors) are easily contaminated by cotton dust, leading to decreased light transmittance and malfunctions. Existing cleaning technologies have three major drawbacks:

[0003] 1. Manual cleaning requires machine downtime, resulting in a loss of 15 minutes of production capacity per shift; it also involves physical contact damage, with wiping causing scratches on the optical surface, leading to a monthly failure rate as high as 18%.

[0004] 2. Fixed-cycle blowing lacks condition awareness, and the fixed cycle can lead to over-cleaning or under-cleaning. In addition, the direct blowing design can cause damage, and vertical spraying accelerates lens aging (experimental data shows that direct blowing has a wear rate 3.2 times higher than 15° tilt angle).

[0005] 3. The negative pressure adsorption scheme results in excessive energy consumption, with a single unit consuming more than 5 kWh per day; and the removal rate of adhesive dust is low: the removal efficiency for <5 μm cotton dust is less than 60%.

[0006] In particular, the dust concentration in the fine-textured workshop can reach 20 mg / m³. 3 (Four times the limit of GBZ 2.1 standard), existing technologies cannot balance cleaning efficiency and equipment safety. Therefore, there is an urgent need for an automated cleaning solution that can respond to pollution status in real time, is contactless, and energy-efficient.

[0007] Therefore, it is evident that the existing automatic cleaning methods and systems for fine-grained photoelectric sensors based on timed compressed air purging still have inconveniences and shortcomings in terms of method and use, and urgently require further improvement. To address the problems existing in the automatic cleaning methods and systems for fine-grained photoelectric sensors based on timed compressed air purging, relevant manufacturers have spared no effort in seeking solutions, but for a long time, no suitable design has been developed, and general methods lack appropriate methods and systems to solve the aforementioned problems. This is clearly a problem that relevant industries urgently need to solve.

[0008] In view of the shortcomings of existing automatic cleaning methods and systems for fine-grained photoelectric sensors based on timed compressed air purging, the inventor, based on years of rich practical experience and professional knowledge in the design and manufacture of such products, and in conjunction with theoretical application, actively researched and innovated to create a new automatic cleaning method and system for fine-grained photoelectric sensors based on timed compressed air purging. This new method and system can improve upon existing methods and systems based on timed compressed air purging, making them more practical. After continuous research, design, and repeated trials and improvements, this invention, which has real practical value, has finally been created. Summary of the Invention

[0009] The main objective of this invention is to overcome the shortcomings of existing automatic cleaning methods and systems for fine-network photoelectric sensors based on timed compressed air blowing, and to provide a new cleaning method and system. The technical problem to be solved is to improve its cleaning efficiency and accuracy, thereby making it more suitable for practical use and having industrial application value.

[0010] Another objective of this invention is to provide an automatic cleaning method and system for fine-grained photoelectric sensors based on timed compressed air blowing. The technical problem to be solved is to ensure the reliability and safety of the system, thereby making it more suitable for practical use.

[0011] Another objective of this invention is to provide an automatic cleaning method and system for fine-grained photoelectric sensors based on timed compressed air blowing. The technical problem to be solved is to enable intelligent operation and maintenance and fault prediction, thereby making it more suitable for practical use.

[0012] Another objective of this invention is to provide an automatic cleaning method and system for fine-network photoelectric sensors based on timed compressed air blowing. The technical problem to be solved is to optimize the system's compatibility and ease of maintenance, thereby making it more suitable for practical use.

[0013] The objective of this invention and the technical problem it solves are achieved through the following technical solution. Based on the closed-loop safety control proposed in this invention, an interlock is formed between a pressure sensor and a PLC, automatically cutting off the gas supply when the gas pressure exceeds the range of 0.3–0.7 MPa.

[0014] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0015] The aforementioned automatic cleaning method and system for fine-linked photoelectric sensors based on compressed air timed blowing, wherein the dual-mode triggering mechanism sets a fixed cleaning cycle T of 1min≤T≤60min through the real-time clock of the PLC, and synchronously obtains light transmittance data in real time by the dust monitoring module, and generates an instant trigger signal when ΔΦ≥10%.

[0016] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0017] The aforementioned automatic cleaning method and system for fine-linked photoelectric sensors based on timed compressed air blowing, wherein the intelligent diagnostic module calculates the rate of change of light transmittance before and after cleaning δ=(Φ1-Φ0) / Φ0×100%, and outputs a blockage / dust accumulation alarm based on the δ value and the maintenance time (e.g., δ<80%→nozzle blockage).

[0018] The objective of this invention and the technical problem it solves are also achieved by the following technical solution. According to the directional high-speed cleaning proposed in this invention, by controlling the opening time t of the explosion-proof solenoid valve (0.3s≤t≤0.5s±10ms), compressed air is accelerated to ≥120m / s through the Venturi nozzle and then directionally sprayed onto the optical surface at a 15° tilt angle.

[0019] Compared with the prior art, the present invention has significant advantages and beneficial effects. As can be seen from the above technical solution, in order to achieve the aforementioned objectives, the main technical contents of the present invention are as follows:

[0020] This invention proposes an automatic cleaning method for fine-grained photoelectric sensors using timed compressed air purging, characterized by comprising:

[0021] Set a fixed cycle T for compressed air injection, where 1 min ≤ T ≤ 60 min;

[0022] The transmittance data of the photoelectric sensor is acquired in real time, and a trigger signal is generated when the transmittance decreases by ΔΦ≥10%.

[0023] In response to a timing signal or the trigger signal, the solenoid valve is controlled to open for a duration t, where 0.3s ≤ t ≤ 0.5s;

[0024] Compressed air is accelerated to ≥120m / s through a Venturi nozzle and then directed at a 15° angle to the optical surface of the sensor.

[0025] Record cleaning events and verify the light transmittance recovery status. If ΔΦ remains ≥10% after cleaning, output a fault alarm.

[0026] Preferably, the compressed air is treated by a pre-filter of 5μm and a post-filter of 0.1μm precision, and the air dew point is ≤-20℃.

[0027] Preferably, the opening duration t of the solenoid valve is controlled by the pulse width modulation module of the PLC, and the time control accuracy is ±10ms.

[0028] This invention also provides an automatic cleaning system for finely interconnected photoelectric sensors that implements a cleaning method, characterized by comprising:

[0029] Air source unit: an oil-free air compressor, an air tank, and a two-stage filter connected in sequence;

[0030] Control unit: PLC with built-in real-time clock, communication connection to dust monitoring module;

[0031] Actuation unit: an explosion-proof solenoid valve connected to the gas source unit, and a nozzle with a venturi structure, wherein the outlet axis of the nozzle forms a 15° angle with the optical surface of the sensor;

[0032] The airflow direction at the nozzle outlet forms a 15° angle with the normal to the optical surface of the sensor.

[0033] Safety interlock unit: The pressure sensor and PLC form a closed-loop control, configured to cut off the gas supply when the gas pressure is >0.7MPa or <0.3MPa.

[0034] Preferably, the venturi structure nozzle includes:

[0035] The contraction angle α of the tapering section is 12° ± 1°.

[0036] The throat diameter d = 0.8 mm ± 0.05 mm.

[0037] The diffusion angle β of the gradually expanding segment is 8° ± 1°.

[0038] The outer surface is covered with stainless steel protective mesh with an aperture of ≤0.5mm.

[0039] Preferably, the control unit is equipped with an energy consumption optimization module, which performs the following:

[0040] The single gas consumption is calculated using the formula Q = 0.25 × P × t, where P is the real-time pressure value and t is the injection time.

[0041] When the cumulative gas consumption reaches the set threshold, the cleaning cycle T will be extended to 1.2-1.5 times the original value.

[0042] Preferably, the explosion-proof solenoid valve meets the Ex dIIC T4 explosion-proof rating, has an operating voltage of DC24V±10%, and a response time of ≤10ms.

[0043] Preferably, it also includes a diagnostic module, configured as follows:

[0044] Calculate the rate of change of light transmittance before and after cleaning: δ = (Φ1 - Φ0) / Φ0 × 100% (Φ0 is the value before cleaning, and Φ1 is the value after cleaning);

[0045] A nozzle blockage alarm is generated when δ < 80%.

[0046] When δ > 95% but the duration is < 5 min, an alarm for abnormal dust accumulation is generated.

[0047] Preferably, the two-stage filter comprises a cyclone separator and a sintered metal microporous filter connected in series.

[0048] Preferably, the nozzle is connected to the air supply line via a quick-release connector, and the quick-release connector has an embedded O-ring seal.

[0049] As described above, this invention relates to an automatic cleaning method and system for a fine-grained photoelectric sensor based on timed compressed air purging. The method includes: setting a compressed air injection cycle T (1 min ≤ T ≤ 60 min); real-time monitoring of the sensor transmittance, generating a trigger signal when the decrease value ΔΦ ≥ 10%; controlling the opening time t of the solenoid valve in response to the timed or trigger signal (0.3 s ≤ t ≤ 0.5 s); accelerating the compressed air to ≥ 120 m / s through a Venturi nozzle and then directionally injecting it at a 15° tilt angle; recording cleaning events and verifying the transmittance recovery status. The system includes an air source unit, a control unit, an execution unit, and a safety interlock unit to achieve automatic cleaning without stopping the system, reducing the sensor failure rate by 62% and the cotton knot misjudgment rate to 2.1%.

[0050] By employing the above technical solution, the automatic cleaning method and system for fine-networked photoelectric sensors based on timed compressed air purging of the present invention has at least the following advantages:

[0051] By employing a precisely designed Venturi nozzle (contraction angle 12°±1°, throat diameter 0.8mm±0.05mm, diffusion angle 8°±1°), combined with directional spraying at a 15° tilt angle and an airflow velocity ≥120m / s, highly efficient peel-and-strip cleaning of the sensor's optical surface is achieved using compressed air. Simultaneously, real-time transmittance monitoring (ΔΦ≥10% triggers cleaning) and high-precision PLC timing control (spray time t=0.3~0.5s±10ms) ensure accurate removal of contaminants while avoiding over-cleaning that could damage the device.

[0052] Build multiple protection mechanisms:

[0053] The gas source undergoes two-stage filtration (5μm pre-filter + 0.1μm precision post-filter, dew point ≤ -20℃) to prevent oil and water contamination;

[0054] The safety interlock unit monitors the air pressure in real time (0.3~0.7MPa safe range), and automatically cuts off the air supply if the pressure exceeds the limit;

[0055] Explosion-proof solenoid valves (Ex d IIC T4 grade) and stainless steel protective mesh (aperture ≤0.5mm) protect against the risks of flammable dust environments and ensure safe operation in industrial sites.

[0056] Dynamic diagnosis based on transmittance recovery status:

[0057] Calculate the change rate before and after cleaning δ=(Φ1-Φ0) / Φ0×100%, and intelligently judge abnormalities based on the δ value (δ<80%→nozzle blockage; δ>95% but maintained for <5min→abnormal dust accumulation);

[0058] Modular design enhances applicability:

[0059] The quick-release connector (with embedded O-ring seal) enables rapid nozzle replacement, adapting to different working conditions;

[0060] The dust monitoring module and PLC real-time clock support both timed cleaning (T = 1~60min) and on-demand triggering modes.

[0061] The combination of cyclone separator and sintered metal microporous filter can cope with high humidity and high dust environments and extend the life of core components.

[0062] By combining the cumulative gas consumption optimization algorithm (Q=0.25×P×t), the cleaning cycle is automatically extended (T→1.2~1.5 times the original value) when the gas consumption exceeds the threshold, thereby reducing operation and maintenance costs.

[0063] In summary, the present invention provides a unique automatic cleaning method and system for fine-grained photoelectric sensors based on timed compressed air purging, achieving precise and efficient cleaning, multiple safety protections, and intelligent operation and maintenance with reduced energy consumption. It possesses numerous advantages and practical value, and is truly innovative as no similar designs have been publicly disclosed or used in similar methods. It represents a significant improvement in both method and function, a substantial technological advancement, and produces user-friendly and practical results. Compared to existing automatic cleaning methods and systems for fine-grained photoelectric sensors based on timed compressed air purging, it offers several enhanced functions, making it more suitable for practical application and possessing broad industrial value. It is indeed a novel, progressive, and practical new design.

[0064] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0065] The specific methods and structures of the present invention are given in detail in the following embodiments and accompanying drawings. Attached Figure Description

[0066] Figure 1 : Workflow diagram of an automatic cleaning method for fine-grained photoelectric sensors based on timed compressed air blowing;

[0067] Figure 2 Schematic diagram of the automatic cleaning system based on compressed air timed blowing using fine-linked photoelectric sensors.

[0068] The above figures include the following reference numerals:

[0069] Air source unit 1, oil-free air compressor 101, air tank 102, two-stage filter 103, control unit 2, PLC 201, dust monitoring module 202, execution unit 3, explosion-proof solenoid valve 301, nozzle 302, converging section 3021, throat 3022, diverging section 3023, safety interlock unit 4, pressure sensor 401, stainless steel protective mesh 3024, O-ring seal 3031, diagnostic module 5 Detailed Implementation

[0070] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation methods, steps, structure, features, and effects of the automatic cleaning method and system for fine-network photoelectric sensors based on timed compressed air blowing proposed in accordance with the present invention.

[0071] Please see Figure 1 , Figure 2 As shown, the preferred embodiment of the present invention, an automatic cleaning method and system for fine-grained photoelectric sensors based on timed compressed air blowing, mainly includes the following steps:

[0072] Example 1:

[0073] In the sintering workshop of a steel plant, the concentration of this type of dust is extremely high (≥20g / m³). 3 In this environment, the automatic cleaning method is implemented as follows: A fixed cleaning cycle T = 1 minute is set for compressed air injection, and the transmittance of the photoelectric sensor is monitored in real time. When dust accumulation is detected, causing a decrease in transmittance of ΔΦ = 15%, the system immediately generates a trigger signal. In response to this trigger signal, the PLC's pulse width modulation module precisely controls the explosion-proof solenoid valve, with an opening duration t = 0.30 s. Compressed air is processed through a pre-filter (5 μm) and a post-filter (0.1 μm precision filter), and the resulting airflow flows through a Venturi nozzle. This nozzle design includes: a contraction angle α = 11° in the converging section, a throat diameter d = 0.85 mm, a diffusion angle β = 9° in the expanding section, and an outer surface covered with a stainless steel protective mesh with an aperture ≤ 0.5 mm. The compressed air is accelerated to ≥ 125 m / s under this structure and then directionally injected at a 15° tilt angle onto the sensor's optical surface. The system automatically records this cleaning event. The safety interlock unit continuously monitors the pressure; when the real-time air pressure rises to > 0.72 MPa, the PLC immediately cuts off the air supply. After cleaning, the light transmittance was verified to have recovered to δ = 96% of its original value. Based on the diagnostic module logic, the system determined that although it was greater than the 80% blockage threshold, the recovery maintenance time was less than 5 minutes, so it output an "abnormal dust accumulation alarm".

[0074] Example 2:

[0075] In environments with relatively low dust levels but requiring stable maintenance, such as food packaging workshops, this method focuses on energy-saving optimization. A fixed cleaning cycle T = 60 minutes is set for compressed air injection. A transmittance reduction threshold ΔΦ ≥ 10% is used as a backup trigger condition. When the 60-minute timer signal is triggered, the PLC controls the solenoid valve to open for a duration t = 0.50 seconds. The compressed air source undergoes two-stage filtration, and the pressure is set near the system's stable operating point. In the execution unit, compressed air drives an explosion-proof solenoid valve that meets Exd IIC T4 rating and is powered by DC24V±10%, flowing through a Venturi nozzle. The nozzle throat diameter d = 0.75mm ensures efficient accelerated airflow, with a measured flow velocity greater than or equal to 128m / s. The nozzle is connected to the air supply line via a quick-release connector. The airflow is precisely sprayed onto the sensor surface at a 15° tilt angle. The energy consumption optimization module operates in real time: It calculates the gas consumption per cycle based on the formula Q = 0.25 × P × t. For example, when the measured P is 0.31 MPa and t = 0.50 s, Q = 0.25 × 0.31 × 0.5 = 0.03875 m³ / s. 3 When the cumulative gas consumption reaches a preset threshold, the module dynamically extends the cleaning cycle T to 1.5 times the original value, i.e., 90 minutes. The safety interlock unit cuts off the gas supply when it detects an unexpected pressure drop to less than 0.29 MPa. The diagnostic module operates after cleaning: it calculates the light transmittance recovery rate δ. If δ = 77%, it immediately generates a "nozzle blockage alarm" and notifies maintenance.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the methods and techniques disclosed above without departing from the scope of the present invention to create equivalent embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for automatic cleaning of a fine-structured photoelectric sensor by timed compressed air blowing, characterized in that... include: Set a fixed cycle T for compressed air injection, where 1 min ≤ T ≤ 60 min; The transmittance data of the photoelectric sensor is acquired in real time, and a trigger signal is generated when the transmittance decreases by ΔΦ≥10%. In response to a timing signal or the trigger signal, the solenoid valve is controlled to open for a duration t, where 0.3s ≤ t ≤ 0.5s; Compressed air is accelerated to ≥120m / s through a Venturi nozzle and then directed at a 15° angle to the optical surface of the sensor. Record cleaning events and verify the light transmittance recovery status. If ΔΦ remains ≥10% after cleaning, output a fault alarm.

2. The automatic cleaning method for compressed air timed purging of fine-structured photoelectric sensors according to claim 1, characterized in that: The compressed air is processed by a pre-filter of 5μm and a post-filter of 0.1μm precision, and the air dew point is ≤-20℃.

3. The automatic cleaning method for compressed air timed purging of fine-structured photoelectric sensors according to claim 1, characterized in that: The opening duration t of the solenoid valve is controlled by the pulse width modulation module of the PLC, with a time control accuracy of ±10ms.

4. An automatic cleaning system for a finely interconnected photoelectric sensor that implements any one of claims 1-3, characterized in that... include: Air source unit (1): an oil-free air compressor (101), an air tank (102), and a two-stage filter (103) connected in sequence; Control unit (2): PLC (201) with built-in real-time clock, and communication connection to dust monitoring module (202); Execution unit (3): Explosion-proof solenoid valve (301) connected to the gas source unit, and nozzle (302) with venturi structure, wherein the outlet axis of the nozzle forms a 15° angle with the optical surface of the sensor; Safety interlock unit (4): The pressure sensor (401) and PLC form a closed-loop control, configured to cut off the gas supply when the gas pressure is >0.7MPa or <0.3MPa.

5. The automatic cleaning system for fine-grained photoelectric sensors according to claim 4, characterized in that: The Venturi structure nozzle (302) includes: The contraction angle α of the tapering segment (3021) is 12° ± 1°. The diameter of the throat (3022) is d = 0.8 mm ± 0.05 mm. The diffusion angle β of the gradually expanding segment (3023) is 8° ± 1°. The outer surface is covered with stainless steel protective mesh (3024) with an aperture of ≤0.5mm.

6. The automatic cleaning system for fine-grained photoelectric sensors according to claim 4, characterized in that: The control unit (2) is equipped with an energy consumption optimization module, which executes: The single gas consumption is calculated using the formula Q = 0.25 × P × t, where P is the real-time pressure value and t is the injection time. When the cumulative gas consumption reaches the set threshold, the cleaning cycle T will be extended to 1.2-1.5 times the original value.

7. The system according to claim 4, characterized in that: The explosion-proof solenoid valve (301) meets the Ex d IIC T4 explosion-proof rating, has a working voltage of DC24V±10%, and a response time of ≤10ms.

8. The automatic cleaning system for fine-grained photoelectric sensors according to claim 4, characterized in that: It also includes a diagnostic module (5), which is configured as follows: Calculate the rate of change of light transmittance before and after cleaning: δ = (Φ1 - Φ0) / Φ0 × 100% (Φ0 is the value before cleaning, and Φ1 is the value after cleaning); A nozzle blockage alarm is generated when δ < 80%. When δ > 95% but the duration is < 5 min, an alarm for abnormal dust accumulation is generated.

9. The automatic cleaning system for fine-grained photoelectric sensors according to claim 4, characterized in that: The two-stage filter (103) includes a cyclone separator and a sintered metal microporous filter connected in series.

10. The automatic cleaning system for fine-grained photoelectric sensors according to claim 4, characterized in that: The nozzle (302) is connected to the air supply line via a quick-release connector (303), and the quick-release connector is embedded with an O-ring seal (3031).

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