A positive and negative pressure centralized air supply system for a printing and binding plant

Abstract

This invention discloses a centralized positive and negative pressure gas supply system for printing and binding workshops, belonging to the field of printing gas supply technology. The invention aims to solve the problems of low integration, high energy consumption, and poor gas quality in existing gas supply systems. The system includes: a positive pressure subsystem, a negative pressure subsystem, a purification unit, an intelligent control unit, and an energy recovery unit. The energy recovery unit recovers the compression heat generated by the positive pressure subsystem for preheating the negative pressure subsystem or for workshop heating. The purification unit employs multi-stage precision filtration and self-cleaning pulse backflushing technology to ensure gas supply quality. The intelligent control unit incorporates a dual-mode control strategy and a predictive maintenance module to achieve optimized system operation and intelligent management. Through high integration and energy cascade utilization, this invention significantly reduces system energy consumption and workshop noise, improves gas supply quality and equipment operational reliability, and provides an energy-saving, environmentally friendly, and efficient centralized gas supply solution for printing and binding workshops.

Description

Technical Field

[0001] This invention relates to the field of printing and binding equipment technology, and in particular to a centralized positive and negative pressure air supply system for a printing and binding workshop. Specifically, it relates to a centralized air supply system for providing stable and clean positive and negative pressure air sources for multiple air-consuming devices in a printing and binding workshop. Background Technology

[0002] In the printing and binding production process, a large number of devices rely on compressed air and vacuum negative pressure to complete their operations. For example, printing press feeders require positive pressure air for paper separation and blowing, while paper receiving devices, staplers, and perfect binding machines require negative pressure to absorb and transport paper. The traditional air supply method involves configuring a small air compressor and vacuum pump for each piece of equipment. This decentralized air supply model has many drawbacks: Harsh workshop environment: Multiple small air compressors and vacuum pumps are scattered throughout the workshop, and the heat, noise, and vibration generated during their operation severely deteriorate the working environment, affecting the physical and mental health of workers. Low energy efficiency: The energy efficiency ratio of a single piece of equipment is usually low, and energy complementarity and synergistic optimization between equipment cannot be achieved, resulting in high overall energy consumption. Difficult maintenance and management: The large number and scattered distribution of equipment lead to a heavy maintenance workload, complex spare parts management, and difficulty in unified monitoring and management. Unstable air source quality: Small equipment has limited air handling capacity (drying and filtering), large fluctuations in supply pressure, and high oil and water content, which can easily damage precision pneumatic components, affecting production efficiency and product quality.

[0003] To address the aforementioned issues, centralized air supply systems have emerged in the prior art, placing air compressors, vacuum pumps, and other components in a dedicated machine room and supplying gas to the workshop via pipelines. For example, patent CN207416284U discloses a centralized air supply device for a packaging and printing production line, placing air compressors and air tanks inside the machine room and supplementing them with sound-absorbing cotton to reduce noise. Patent CN208886376U further places the air compressor outside the workshop to reduce the impact of heat and noise. However, these solutions still have room for improvement: Insufficient system integration: Most solutions only focus on a single positive or negative pressure system, without designing and controlling the two as an organic whole, resulting in equipment redundancy and a large computer room footprint.

[0004] Significant energy waste: Air compressors generate a large amount of heat during air compression, which is typically released directly into the environment, resulting in substantial energy waste. While some technologies, such as CN115164103B, attempt to utilize waste heat to dry desiccants, their utilization efficiency and scope are limited, failing to achieve system-level heat recovery and reuse. More importantly, no existing technology recognizes that the recovered heat of compression can be used in a cascade manner to preheat negative pressure systems (especially vacuum pumps), thereby reducing energy consumption in positive pressure systems while improving the operating efficiency and stability of negative pressure systems.

[0005] The purification process is often limited: the purification stage of the air supply system typically only includes simple filtration and drying, which is insufficient to effectively remove oil mist, fine dust, and other contaminants from compressed air. This is inadequate for printing and binding equipment that requires high-quality air supply. Especially in negative pressure systems, gas containing large amounts of paper fibers and dust is directly drawn into the vacuum pump, causing not only pipe blockage but also severe wear on the pump's internal rotor, coating, and seals, significantly shortening its lifespan. Current technologies generally do not adequately address the purification of the intake air on the negative pressure side, lacking effective and targeted solutions.

[0006] Low level of intelligence: The system relies heavily on manual monitoring and adjustment, unable to automatically adjust equipment operation based on changes in workshop gas load, and lacking predictive maintenance. This results in the system operating under suboptimal conditions, leading to high energy consumption and a high failure rate. Traditional control methods only achieve "reactive response," adjusting only after pressure fluctuations occur, resulting in unstable gas supply quality. The lack of real-time monitoring and prediction of equipment health status forces maintenance to rely on "periodic inspections" or "reactive repairs," leading to high maintenance costs and severe disruptions to production due to sudden shutdowns.

[0007] Therefore, developing a highly integrated, energy-efficient, high-quality gas supply system with intelligent control capabilities for printing and binding workshops is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a positive and negative pressure centralized air supply system for printing and binding workshops. This system achieves intensive, high-quality and energy-saving positive and negative pressure air supply through integrated design and intelligent collaborative control.

[0009] The above-mentioned objective of this invention is achieved through the following technical solutions: This invention provides a centralized positive and negative pressure air supply system for a printing and binding workshop, comprising: a positive pressure subsystem for generating and outputting compressed air; a negative pressure subsystem for generating and outputting vacuum negative pressure; a purification unit connected to the positive pressure subsystem and the negative pressure subsystem respectively, for performing multi-stage purification treatment on the compressed air and vacuum negative pressure gas; an intelligent control unit electrically connected to the positive pressure subsystem, the negative pressure subsystem and the purification unit, for realizing automated operation and optimized control of the system; and an energy recovery unit connected to the positive pressure subsystem and the negative pressure subsystem, for recovering the compression heat generated during the operation of the positive pressure subsystem, and at least partially using the recovered heat energy for preheating the negative pressure subsystem or for environmental heating of the workshop.

[0010] As one of the core technical concepts of this invention, the energy recovery unit breaks the inherent pattern of independent positive and negative pressure subsystems and unidirectional energy flow in traditional air supply systems. By constructing a closed-loop thermal energy circulation system, this invention achieves for the first time in the field of printing and binding air supply the conversion of "waste heat" from the positive pressure subsystem to "effective energy" from the negative pressure subsystem. This "positive-to-negative" energy cascade utilization mode is not a simple superposition of the functions of the positive and negative pressure subsystems, but rather produces a profound synergistic effect: on the one hand, the positive pressure subsystem (air compressor) reduces the load on the cooling system due to efficient waste heat recovery, enabling it to operate in a more optimal temperature range and extending the life of lubricating oil and the main unit; on the other hand, the negative pressure subsystem (vacuum pump) significantly reduces the mechanical resistance during startup and operation due to preheating, especially in low-temperature environments or during startup after long-term shutdown. The preheated pump body can enter the optimal working state more quickly, reducing the additional wear and energy consumption caused by cold starts. This deep coupling of positive and negative pressure subsystems at the thermodynamic level achieves a leap in overall system energy efficiency, with its comprehensive energy-saving effect far exceeding the arithmetic sum of energy-saving improvements made to each subsystem separately.

[0011] According to one embodiment of the present invention, the energy recovery unit includes: a heat exchanger, the high-temperature side inlet of which is connected to the oil-gas separator outlet of the positive pressure subsystem; a circulating pump connected to the low-temperature side of the heat exchanger; and an energy distribution module, the inlet of which is connected to the low-temperature side outlet of the heat exchanger, and the outlet of which includes at least a first branch and a second branch; wherein the first branch is connected to a preheating jacket disposed on the negative pressure subsystem, and the second branch is connected to a radiator disposed in the workshop.

[0012] The preheating jacket is preferably a high-efficiency thermally conductive jacket wrapped around the outside of the dry screw vacuum pump body. Its interior features a labyrinthine flow channel to increase the heat exchange area and turbulence, thereby improving heat exchange efficiency. The design of the preheating jacket ensures that heat is transferred evenly and quickly to the core components of the pump body, preventing localized overheating. The energy distribution module integrates an electric proportional control valve, a temperature sensor, and a flow meter. Based on instructions from the intelligent control unit, it dynamically adjusts the flow ratio of the heat transfer medium to the first and second branches. For example, in winter when the workshop temperature is low, priority is given to the second branch for workshop heating; while during the cold start phase of the vacuum pump, priority is given to the first branch for rapid preheating, ensuring that the vacuum pump reaches its optimal operating temperature within 3-5 minutes. This intelligent energy distribution mechanism ensures that the recovered heat energy is always allocated to the most needed components, maximizing energy utilization efficiency.

[0013] According to one embodiment of the present invention, the purification unit includes: a refrigerated air dryer and a multi-stage precision filter assembly disposed on the outlet pipeline of the positive pressure subsystem; and a self-cleaning pulse backflush filter disposed on the inlet pipeline of the negative pressure subsystem.

[0014] The self-cleaning pulse backflush filter is another key technological innovation of this invention. Addressing the industry challenge of adhesive impurities such as paper fibers, dust, and fibers in the negative pressure return air of printing and binding workshops, this invention abandons the traditional method of using disposable filter cartridges or simple metal mesh filtration, and introduces a self-cleaning pulse backflush filter with automatic cleaning function. The filter works as follows: dust-laden gas passes through the filter cartridge from the outside in, impurities are trapped on the outer surface of the cartridge, and clean gas enters the clean air chamber. When the pressure difference between the filter inlet and outlet reaches a set threshold (e.g., 1.2 kPa) or reaches a preset time period (e.g., every 4 hours), the intelligent control unit triggers a pulse backflush command, instantly opening the pulse valve and injecting 0.5-0.8 MPa compressed air in a pulsed manner (pulse width approximately 0.1 seconds) into the filter cartridge in the reverse direction, generating a strong shock wave and reverse airflow, causing the paper fibers, dust, and other impurities adhering to the outer surface of the filter cartridge to instantly fall into the dust collection hopper below. This process enables the filter to "self-clean," avoiding frequent manual replacement of the filter element, ensuring the long-term smooth flow of the negative pressure system pipeline, and significantly reducing the risk of vacuum level drop and vacuum pump overload caused by pipeline blockage.

[0015] According to one embodiment of the present invention, the multi-stage precision filtration assembly includes a cyclone separator, a condenser filter, an activated carbon filter, and a high-efficiency oil removal filter connected in sequence.

[0016] This four-stage cascaded filter chain constitutes a deep purification system for compressed air. The cyclone separator utilizes centrifugal force to efficiently separate and remove over 90% of liquid water and solid particles larger than 10μm from the compressed air. The condensing filter, through its internal borosilicate glass fiber media, condenses tiny oil mist and solid particles of 0.01μm to 1μm into larger droplets and separates them, reducing the residual oil content in the compressed air to below 0.1mg / m³. The activated carbon filter, with its large specific surface area and adsorption capacity, effectively adsorbs and removes oil vapor, volatile organic compounds (VOCs), and odors from the compressed air, ensuring that downstream pneumatic components are not chemically contaminated. The high-efficiency oil removal filter, as the final barrier, further intercepts any remaining trace amounts of oil mist, controlling the residual oil content to below 0.01mg / m³, meeting the ISO 8573-1 Class 0 (oil-free) standard. Through the synergistic effect of these four-stage filtration components, the compressed air output by this invention is of a quality far exceeding the general requirements of the printing and binding industry for air source quality, providing a fundamental guarantee for the long-term stable operation of precision pneumatic actuators (such as high-frequency solenoid valves and precision cylinders).

[0017] According to one embodiment of the present invention, the intelligent control unit includes: a data acquisition module for acquiring real-time data from various sensors; a main control PLC with a built-in dual-mode control strategy, the dual-mode control strategy including a feedforward control model based on gas demand prediction and a PID control model based on real-time pressure feedback; a human-machine interface; and a remote communication module.

[0018] The feedforward control model based on gas demand forecasting is one of the core intelligent features of this invention. This model interacts with the workshop's Manufacturing Execution System (MES) to obtain the printing and binding production plan for a future period (e.g., the next 4 hours, 8 hours, or one shift), including the planned paper type, weight, quantity, and start / stop times of each gas-consuming device. Combining historical gas consumption data, the model uses deep learning algorithms (such as Long Short-Term Memory networks, LSTM) to establish a gas load forecasting model, enabling it to predict positive and negative pressure demands in advance. Based on this prediction, the main control PLC can adjust the number of operating screw air compressors and dry screw vacuum pumps, the target frequency of the frequency converter, and the energy allocation ratio of the energy recovery unit in advance, ensuring the system is always in a proactive "predictive-prepared-response" operating state, rather than a lagging "fluctuation-detection-adjustment" state.

[0019] The PID control model based on real-time pressure feedback, serving as a supplement and fine-tuning mechanism to feedforward control, ensures highly stable gas supply pressure. When minor fluctuations in gas supply pressure occur due to temporary changes in production plans or unforeseen gas consumption surges, the PID control model responds in milliseconds to fine-tune the frequency converters of the air compressor and vacuum pump in real time, quickly eliminating deviations. This dual-mode control strategy combining feedforward and feedback offers the dual advantages of "predictability" and "real-time performance." It avoids the deviations that may result from inaccurate predictions in pure feedforward control, and overcomes the inherent lag of pure feedback control. This achieves precise and stable control of the gas supply pressure, with fluctuations controlled within ±0.5 kPa, far superior to traditional control methods.

[0020] According to one embodiment of the present invention, the main control PLC also has a built-in predictive maintenance module, which is used to perform equipment health assessment and fault early warning based on the historical data trends of vibration sensors, temperature sensors and current sensors installed on the positive pressure subsystem and the negative pressure subsystem.

[0021] This predictive maintenance module continuously collects and analyzes historical data from vibration sensors (collecting vibration characteristic values ​​such as displacement, velocity, and acceleration), temperature sensors (monitoring motor winding temperature, bearing temperature, exhaust temperature, etc.), and current sensors (monitoring three-phase current balance, current harmonics, etc.) installed on critical equipment to construct a "health baseline" model for the equipment. The module employs machine learning algorithms based on Gaussian process regression or support vector machines to compare and analyze real-time monitoring data with the health baseline. When the monitoring data deviates from the baseline to a preset threshold (e.g., vibration amplitude exceeding the baseline by 50%, or current energy consumption efficiency falling below the historical average by 15%), the system can automatically identify potential fault types (e.g., bearing wear, rotor imbalance, inter-turn short circuits in the motor), and issue warning information through the human-machine interface, prompting maintenance personnel to "maintain as needed." This shift from "reactive maintenance" to "condition-based maintenance" not only significantly reduces the risk of unplanned equipment downtime but also extends the service life of critical components and reduces overall maintenance costs through precise maintenance timing.

[0022] According to one embodiment of the present invention, it further includes a soundproof and noise-reducing cabin for accommodating the positive pressure subsystem and the negative pressure subsystem; the inner wall of the soundproof and noise-reducing cabin is sequentially provided with a damping sound insulation layer, a sound-absorbing cotton layer and a microporous aluminum plate layer.

[0023] This multi-layered composite structure is optimized for noise at different frequencies. The outermost damping and sound-insulating layer (composed of high-density damping rubber and galvanized steel plate) primarily isolates and dampens low-frequency, high-intensity structural vibration noise. The middle sound-absorbing cotton layer (such as high-density centrifugal glass wool) efficiently absorbs mid-to-high frequency airborne noise. The innermost microporous aluminum plate layer serves as a protective layer for the sound-absorbing cotton, and its microporous structure further enhances the sound absorption effect. Through this multi-layered, multi-mechanism composite noise reduction design, the noise generated by equipment operating inside the cabin (typically as high as 90-100 decibels) can be effectively reduced to below 75 decibels when it propagates outside the cabin, fully meeting the noise control requirements of the workshop environment and significantly improving the working environment for workshop workers.

[0024] According to one embodiment of the present invention, a forced exhaust duct is provided on the soundproof and noise-reducing cabin, and the forced exhaust duct is connected to the heat sink of the energy recovery unit.

[0025] This design embodies the synergistic effect of the energy recovery unit and the soundproof and noise-reducing cabin. Typically, the operation of equipment within the cabin generates a significant amount of unrecovered heat. If this heat is not dissipated promptly, it can cause the cabin temperature to rise, affecting the equipment's heat dissipation efficiency and lifespan. This invention connects the forced exhaust duct to the workshop radiators. On one hand, exhaust fans actively extract hot air from the cabin, maintaining a suitable operating temperature. On the other hand, this hot air, originally considered "waste heat," is directly guided to the workshop radiators, serving as a supplementary heat source for workshop heating. This is equivalent to reusing the waste heat from the positive pressure subsystem that was not recovered by the heat exchanger, further improving the overall thermal efficiency of the system and extending the concept of energy cascade utilization.

[0026] According to one embodiment of the present invention, an emergency backup unit is further included, the emergency backup unit comprising a backup air compressor connected in parallel with the positive pressure subsystem and a backup vacuum pump connected in parallel with the negative pressure subsystem.

[0027] The inclusion of an emergency backup unit significantly enhances the reliability of the system's air supply. In the event of a malfunction in the main air compressor or vacuum pump, during routine maintenance, or when a surge in peak demand leads to insufficient air supply, the intelligent control unit can seamlessly switch between systems within milliseconds or seconds, automatically activating backup equipment and adjusting to the required frequency to ensure that air supply interruptions are imperceptible to the end users in the workshop. This high redundancy design is particularly important for printing and binding companies operating 24 / 7, effectively preventing production line downtime and order delays due to air supply interruptions, demonstrating its high practical value.

[0028] According to one embodiment of the present invention, the positive pressure subsystem includes a permanent magnet variable frequency screw air compressor and a pressure-stabilized air storage tank; the negative pressure subsystem includes a permanent magnet variable frequency dry screw vacuum pump and a vacuum buffer tank.

[0029] The application of permanent magnet variable frequency technology enables air compressors and vacuum pumps to achieve stepless speed regulation within a range of 20%-100% according to changes in air demand. This avoids the current surges and energy waste caused by frequent start-stop cycles of traditional power frequency equipment, and forms the physical basis for the dual-mode control strategy of the intelligent control unit. The selection of dry screw vacuum pumps ensures oil-free operation within the pump chamber, eliminating pollution to the vacuum system and workshop environment caused by lubricating oil emulsification and backflow at the source. Together with the negative pressure purification branch of the purification unit, it forms a double guarantee of cleanliness.

[0030] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: High integration improves the environment: The positive and negative pressure air supply equipment is integrated into the soundproof and noise-reducing cabin and placed outside or in a partition of the printing and binding workshop, which completely isolates the noise, heat and vibration generated by the operation of the equipment, creating a quiet and comfortable working environment for the workshop.

[0031] Energy-efficient and highly effective, with cascaded energy utilization: By setting up an energy recovery unit, the compression heat generated by the air compressor is efficiently recovered and cascaded for use in vacuum pump preheating and workshop heating, greatly reducing the total system energy consumption and workshop heating energy consumption. Statistics show that after adopting this invention, the overall system energy saving rate can reach 25%-35%. More importantly, this invention creatively achieves deep coupling and synergistic effect of positive and negative pressure subsystems at the thermodynamic level. This "positive-to-negative" energy utilization mode transforms the "waste heat" of the positive pressure subsystem into "effective energy" that improves the efficiency and stability of the negative pressure subsystem, resulting in energy savings far exceeding the simple sum of the energy savings of the two systems.

[0032] High-quality air supply ensures equipment lifespan: Utilizing multi-stage precision filtration and deep drying technology, combined with a self-cleaning pulse backflush filter, it effectively removes oil, moisture, dust, and harmful gases from compressed air, and prevents paper lint blockage in negative pressure pipelines. This significantly improves air supply quality, extends the service life of air-using equipment, and reduces equipment failure rates. In particular, the introduction of the self-cleaning pulse backflush filter provides a long-term, stable, and maintenance-free air purification solution for negative pressure systems, solving the long-standing problems of negative pressure pipeline blockage and vacuum pump wear in the printing and binding industry, resulting in unexpected technical benefits.

[0033] Intelligent control and optimized operation: Through intelligent control units and a dual-mode control strategy, the gas supply system dynamically tracks and predictively adjusts its gas load, ensuring that the system always operates within its high-efficiency range and avoiding energy waste caused by over-engineering. Simultaneously, the predictive maintenance module transforms "reactive maintenance" into "condition-based maintenance," improving system reliability and maintenance efficiency. The dual-mode control strategy combining feedforward and feedback control, along with the predictive maintenance module based on machine learning algorithms, together construct an intelligent gas supply system with "self-sensing, self-learning, self-decision-making, and self-execution" capabilities. Its level of intelligence far surpasses existing technologies, providing crucial underlying support for intelligent manufacturing in printing and binding workshops.

[0034] Compact structure and easy deployment: The system adopts a modular design, and each unit (positive pressure, negative pressure, purification, energy recovery, control) can be pre-installed in a standard container or cabin. On-site, only water, electricity and gas supply pipelines need to be connected for quick use, which greatly shortens the construction cycle.

[0035] The various technical features of this invention do not exist in isolation, but are integrated and mutually supportive through careful design, resulting in unexpected synergistic effects. Specifically, the compression heat recovered by the energy recovery unit not only heats the workshop but, more importantly, preheats the dry screw vacuum pump. This design allows the vacuum pump to quickly enter its high-efficiency operating range in low-temperature environments, reducing cold-start wear and extending equipment life—an effect that cannot be achieved by a standalone energy recovery unit or a standalone variable frequency vacuum pump. Simultaneously, the intelligent control unit, through production plan prediction, not only optimizes the operation of the air compressor and vacuum pump but also proactively adjusts the heat distribution of the energy recovery unit, ensuring that vacuum pump preheating and workshop heating receive the most sufficient heat when most needed, achieving "spatiotemporal optimization" of energy management. Furthermore, the soundproof and noise-reducing cabin centrally isolates the equipment, improving the environment. Its forced exhaust duct, connected to the workshop radiators, also utilizes the "secondary waste heat" within the cabin that was not recovered by the heat exchanger, achieving complete utilization of all heat emissions from the system. The synergistic effect between these features has led to a qualitative leap in the energy efficiency, stability, reliability, and intelligence of the entire system, resulting in a system-level, non-linear performance improvement. Attached Figure Description

[0036] Figure 1 This is a structural block diagram of a positive and negative pressure centralized air supply system for a printing and binding workshop according to the present invention.

[0037] Figure 2 This is a schematic diagram of the system control principle of the present invention.

[0038] Reference numerals: 100, Positive pressure subsystem; 110, Screw air compressor; 120, Pressure-stabilizing air tank; 130, Pre-filter; 200, Negative pressure subsystem; 210, Dry screw vacuum pump; 220, Vacuum buffer tank; 300, Purification unit; 310, Refrigerated air dryer; 320, Multi-stage precision filter assembly; 321, Cyclone separator; 322, Coagulating filter; 323, Activated carbon filter; 324, High-efficiency oil removal filter; 330, Self-cleaning filter. 340. Pulse backflush filter; 400. High-efficiency vacuum filter; 410. Intelligent control unit; 420. Data acquisition module; 430. Main control PLC; 440. Human-machine interface; 440. Remote communication module; 500. Energy recovery unit; 510. Plate heat exchanger; 520. Circulation pump; 530. Energy distribution module; 540. Preheating jacket; 550. Workshop radiator; 600. Soundproof and noise-reducing machine room; 610. Forced air intake duct; 620. Forced exhaust duct. Detailed Implementation

[0039] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] This invention discloses a positive and negative pressure centralized air supply system for a printing and binding workshop, comprising: Positive pressure subsystem 100 is used to generate and output clean compressed air; The negative pressure subsystem 200 is used to generate and output a stable vacuum negative pressure; The purification unit 300 is connected to the positive pressure subsystem 100 and the negative pressure subsystem 200 respectively, and is used to perform multi-stage purification treatment on compressed air and vacuum negative pressure gas. The intelligent control unit 400 is electrically connected to the positive pressure subsystem 100, the negative pressure subsystem 200, and the purification treatment unit 300, and is used to realize the automated operation and optimized control of the system; The energy recovery unit 500 is connected to the positive pressure subsystem 100 and the negative pressure subsystem 200. It is used to recover the compression heat generated during the operation of the positive pressure subsystem 100 and to use at least part of the recovered heat energy for preheating of the negative pressure subsystem 200 or for ambient heating of the workshop.

[0043] In a preferred embodiment, the energy recovery unit 500 is configured to form a closed-loop control loop with the intelligent control unit 400. The intelligent control unit 400 monitors the inlet temperature of the negative pressure subsystem 200 and the ambient temperature of the workshop in real time. When the temperature of the negative pressure subsystem 200 is detected to be lower than a preset start-up threshold (e.g., 10°C), the control energy distribution module 530 prioritizes directing the high-temperature heat transfer medium to the first branch to heat the preheating jacket 540 until the pump body temperature rises to the optimal operating temperature range (e.g., 40-50°C). Simultaneously, the intelligent control unit 400 also monitors the ambient temperature of the workshop. When the workshop temperature is lower than a preset heating temperature (e.g., 18°C), the control energy distribution module 530 directs some or all of the heat transfer medium to the workshop radiator 550 in the second branch. This dynamic, priority-based energy distribution strategy ensures that the recovered heat energy is always used where it generates the greatest value, achieving graded utilization of energy based on quality.

[0044] As a further improvement of the present invention, the positive pressure subsystem 100 includes: At least one screw air compressor 110; A pressure-stabilizing air storage tank 120 is connected to the outlet of a screw air compressor 110; The screw air compressor 110 is equipped with vibration sensors, temperature sensors and current sensors for monitoring its operating status, all of which are connected in communication with the intelligent control unit 400.

[0045] As a further improvement of the present invention, the negative pressure subsystem 200 includes: At least one dry screw vacuum pump 210; Vacuum buffer tank 220 connected to the inlet of dry screw vacuum pump 210; The dry screw vacuum pump 210 is also equipped with a vibration sensor, a temperature sensor, and a current sensor that communicate with the intelligent control unit 400.

[0046] As a further improvement of the present invention, the purification unit 300 includes: A pre-filter 130 is installed at the air inlet of the screw air compressor 110 and the exhaust port of the dry screw vacuum pump 210 to pre-filter large particulate impurities in the air. The multi-stage precision filter assembly 320 is respectively installed on the outlet pipeline of the pressure-stabilizing gas storage tank 120 and the inlet pipeline of the vacuum buffer tank 220. The multi-stage precision filter assembly 320 includes a cyclone separator 321, a coagulating filter 322, an activated carbon filter 323 and a high-efficiency oil removal filter 324 connected in sequence. The refrigerated air dryer 310 is installed on the outlet pipe of the pressure-stabilizing air tank 120 and is located before the multi-stage precision filter assembly 320 to remove moisture from the compressed air. The self-cleaning pulse backflush filter 330 is installed on the inlet pipe of the vacuum buffer tank 220. It is used to filter out impurities such as paper fibers and dust in the intake gas and has a timed automatic backflush cleaning function, which is controlled by the intelligent control unit 400.

[0047] In one specific embodiment, the self-cleaning pulse backflush filter 330 includes a cylindrical housing with 6-12 pleated filter cartridges vertically installed inside. The filter cartridges are made of oil- and water-resistant, anti-static polyester fiber, with a filtration accuracy of 3μm. The housing is divided into a dust-containing chamber and a clean air chamber. The dust-containing chamber is connected to the workshop's negative pressure return air main, and the clean air chamber is connected to the vacuum buffer tank 220. The pulse backflush system includes a compressed air storage tank, a pulse valve, and a blowpipe. The nozzle of the blowpipe is directly facing the center of each filter cartridge. The intelligent control unit 400 sends a high-level pulse signal to the pulse valve according to a preset time period (e.g., every 4 hours of operation) or according to a signal fed back from the differential pressure transmitter installed on the filter (e.g., when the differential pressure reaches 1.2kPa). The pulse valve opens instantaneously, releasing 0.6MPa of compressed air, completing the reverse blowing of the filter cartridges within 0.1-0.2 seconds. During the pulse-jet cleaning process, the filter cartridge expands instantaneously and generates high-frequency vibrations, shaking off the dust adhering to its surface into the dust collection hopper below. The dust collection hopper can be manually or automatically discharged periodically. This structure and operating method ensure that the filter can maintain low differential pressure operation for a long time, eliminating the need for frequent manual replacement of the filter element. The maintenance cycle can be extended from the traditional 1-2 weeks to 6 months or even longer.

[0048] As a further improvement of the present invention, the energy recovery unit 500 includes: The heat exchanger has its high-temperature side inlet connected to the oil-gas separator outlet of the screw air compressor 110 via a pipeline, and its high-temperature side outlet connected to the cooling system inlet of the screw air compressor 110. The circulating pump 520 is connected to the low-temperature side inlet of the heat exchanger and is used to drive the flow of the circulating medium (such as water or heat transfer oil). The energy distribution module 530 has its inlet connected to the low-temperature side outlet of the heat exchanger, and its outlet includes at least a first branch and a second branch. The first branch is connected to the preheating jacket 540 installed on the dry screw vacuum pump 210 via a pipeline, and is used to preheat the pump body of the vacuum pump. The second branch line connects to radiators installed in the workshop via pipes for workshop heating. Temperature sensors and flow control valves are respectively installed on the first and second branches and electrically connected to the intelligent control unit 400. They are used to dynamically adjust the flow distribution of the circulating medium according to the inlet temperature of the dry screw vacuum pump 210 and the ambient temperature of the workshop.

[0049] The preheating jacket 540 is preferably a detachable structure for easy on-site installation and disassembly. Its interior features spiral or honeycomb flow channels to increase the contact area and turbulence between the heat transfer medium and the pump body surface, achieving a heat transfer coefficient of 500-1000 W / (m²·K). The preheating jacket 540 is externally wrapped with an insulation layer to reduce heat loss and improve heat utilization efficiency. The core of the energy distribution module 530 is a high-precision electric three-way proportional control valve. It receives a 4-20mA analog control signal from the intelligent control unit 400 and can steplessly adjust its opening within the 0-100% range, thereby achieving precise distribution of flow between the two branches. The temperature sensor and flow meter work in conjunction with it, feeding real-time data back to the intelligent control unit 400, forming a closed-loop control circuit to ensure accurate and controllable preheating temperature.

[0050] As a further improvement of the present invention, the system also includes a soundproof and noise-reducing cabin 600 for accommodating the positive pressure subsystem 100 and the negative pressure subsystem 200; the inner wall of the soundproof and noise-reducing cabin 600 is sequentially provided with a damping sound insulation layer, a sound-absorbing cotton layer and a microporous aluminum plate layer; the cabin is provided with a forced air intake channel 610 and a forced air exhaust channel 620, the forced air exhaust channel 620 being connected to the radiator on the second branch of the energy recovery unit 500 to exhaust the hot air in the cabin to the workshop for heating.

[0051] In one specific embodiment, the soundproof and noise-reducing cabin 600 is converted from a standard 20-foot or 40-foot shipping container, with its structure reinforced to meet load-bearing and sound insulation requirements. The damping sound insulation layer consists of a 2mm thick self-adhesive butyl rubber damping board and a 2mm thick galvanized steel plate, forming a constrained damping structure that effectively suppresses structural vibration and low-frequency noise radiation from the steel plate. The sound-absorbing cotton layer uses 80mm thick centrifugal glass wool board with a density of 48kg / m³, exhibiting an extremely high absorption coefficient (α≥0.8) for mid-to-high frequency noise. The microporous aluminum plate layer uses perforated aluminum plates with a thickness of 0.8mm, a pore diameter of 2mm, and a pore spacing of 5mm. This not only serves to decorate and protect the sound-absorbing cotton, but its microporous structure itself also constitutes a Helmholtz resonator, capable of absorbing noise at specific frequencies. The forced air intake duct 610 is located at the bottom of the cabin and is equipped with a G4-grade pre-filter to prevent external dust from entering. The forced exhaust duct 620 is located at the top of the nacelle and is equipped with a low-noise axial flow fan. The air volume is calculated based on the heat dissipation of the equipment in the nacelle, typically ranging from 2000 to 5000 m³ / h. The exhaust duct outlet is connected to the radiator 550 in the workshop via an insulated duct, allowing the exhausted hot air to be used as an auxiliary heat source in winter.

[0052] As a further improvement of the present invention, the intelligent control unit 400 includes: The data acquisition module 410 is used to collect data from various sensors on the positive pressure subsystem 100, negative pressure subsystem 200, purification unit 300 and energy recovery unit 500 in real time, as well as data from pressure sensors, flow sensors, dew point sensors and dust concentration sensors on the workshop air supply main pipe. The main control PLC420 (Programmable Logic Controller) is used to receive data from the data acquisition module 410 and send control commands to each actuator according to the preset control strategy. The human-machine interface 430 (HMI) communicates with the main control PLC 420 to display the system operating status, parameters and alarm information, and provides parameter setting and manual control interfaces; The remote communication module 440 is used to upload system operation data to a cloud server or factory management system and to receive remote control commands.

[0053] The data acquisition module 410 supports multiple industrial fieldbus protocols, such as Modbus RTU, Profibus-DP, Profinet, and EtherNet / IP, and is compatible with sensors and actuators of different brands and models. The acquisition frequency is configurable; for rapidly changing signals (such as pressure and current), it can be set to millisecond-level sampling, while for slowly changing signals (such as temperature), it can be set to second-level or minute-level sampling, to achieve a balance between data accuracy and system load.

[0054] The main control PLC420 adopts a dual-CPU redundant architecture, with one CPU serving as the main controller and the other as a hot standby. When the main controller fails, the standby controller can seamlessly take over within milliseconds, ensuring the continuity of system control. In addition to running dual-mode control strategies and predictive maintenance modules, the PLC also integrates an energy management module. This module can calculate the system's specific power (energy consumption per unit of gas production) and overall energy efficiency ratio in real time, and generate energy consumption reports and energy-saving suggestions, providing decision support for the plant's energy management.

[0055] As a further improvement of the present invention, the main control PLC420 has a preset dual-mode control strategy, including: Feedforward control model: Based on the workshop production plan or historical gas consumption data, predict the gas demand in the future period and adjust the number and speed of the screw air compressor 110 and the dry screw vacuum pump 210 in advance. Feedback control model: Based on real-time data from pressure and flow sensors on the main air supply pipe in the workshop, a PID (proportional-integral-derivative) algorithm is used to adjust the screw air compressor 110 and dry screw vacuum pump 210 in real time to stabilize the air supply pressure and flow.

[0056] In a preferred embodiment, the feedforward control model interacts with the workshop's MES system via the OPC UA (OPC Unified Architecture) interface to automatically acquire production work order information for the next 4, 8, and 24 hours. The model integrates an offline-trained Long Short-Term Memory (LSTM) network model, which considers not only production plans but also multiple characteristic variables such as ambient temperature, humidity, production shifts, and historical gas load patterns to predict future temporal changes in gas load. The prediction results are sent to the feedback control model in the form of a setpoint curve as its adjustment benchmark. The feedback control model employs a variable-gain PID algorithm, automatically adjusting the PID parameters based on the deviation between the actual pressure and the predicted setpoint. When the deviation is large, parameters with a fast response are used; when the deviation is small, parameters with fine-tuning are used, thus achieving an optimal balance between response speed and stability.

[0057] As a further improvement of the present invention, the main control PLC420 also has a built-in predictive maintenance module. This module establishes a health model of the equipment by analyzing the historical data trends of vibration sensors, temperature sensors and current sensors. When the monitored data deviates from the normal range or reaches the preset warning threshold, it automatically generates a maintenance work order and issues an alarm through the human-machine interface 430 or the remote communication module 440.

[0058] The core of the predictive maintenance module is an anomaly detection model based on Isolation Forest or One-Class SVM, and a health assessment model based on Multivariate State Estimation Technique (MSET) or Long Short-Term Memory Network (LSTM). The models are trained using sensor data collected during normal system operation to establish a multi-dimensional "health state space." During real-time monitoring, the module compares continuously collected real-time data points with the health state space, calculates the degree of deviation, and obtains a health score from 0-100%. When the health score continuously declines or falls below a preset threshold (e.g., 80%), the system determines that the equipment has a potential failure risk and uses a rule-based expert system or a decision tree-based classifier to preliminarily determine the failure type (e.g., imbalance, misalignment, bearing failure, poor lubrication, etc.) and suggest maintenance measures (e.g., adding grease, checking alignment, planning bearing replacement, etc.). Maintenance work orders are displayed on the HMI 430 and simultaneously sent to the designated maintenance engineer via SMS, app push, or email through the remote communication module 440. This predictive maintenance function, which covers the entire chain of "early warning-diagnosis-suggestion-notification," greatly improves the efficiency and accuracy of equipment maintenance.

[0059] As a further improvement of the present invention, the system also includes an emergency backup unit, which includes a backup air compressor connected in parallel with the positive pressure subsystem 100 and a backup vacuum pump connected in parallel with the negative pressure subsystem 200. The emergency backup unit is controlled by the intelligent control unit 400 and automatically starts when the main equipment fails or the air supply pressure is insufficient.

[0060] The control logic of the emergency backup unit is designed to be multi-layered and highly reliable. First, when the primary equipment starts, the intelligent control unit 400 performs a self-check to ensure the backup equipment is in a "hot standby" state, meaning it is powered on, in an unloaded or low-speed standby state, and its outlet valve is closed. When the primary equipment shuts down due to a fault, or the main gas supply pressure remains below the set lower limit (e.g., positive pressure below 0.55MPa for 3 seconds, negative pressure above -0.06MPa for 3 seconds), the main control PLC 420 immediately issues a command to complete the following actions within one second: 1) Open the outlet valve of the backup equipment; 2) Quickly increase the frequency of the backup equipment's inverter to the target frequency matching the current demand; 3) Close the outlet valve of the faulty primary equipment and shut it down. The entire process is completed within seconds, with virtually no pressure fluctuation felt at the workshop's gas terminals, achieving seamless switching. Simultaneously, the system will issue an audible and visual alarm on the HMI 430, prompting maintenance personnel to inspect the faulty equipment. Example

[0061] Please see Figure 1 and Figure 2This embodiment provides a positive and negative pressure centralized air supply system for a printing and binding workshop. The system mainly includes: a positive pressure subsystem 100, a negative pressure subsystem 200, a purification unit 300, an intelligent control unit 400, an energy recovery unit 500, a sound insulation and noise reduction cabin 600, and an emergency backup unit.

[0062] The soundproof and noise-reducing cabin 600 is a steel structure enclosure used to house the positive pressure subsystem 100, the negative pressure subsystem 200, and some auxiliary equipment. The inner wall structure of the cabin 600, from the outside in, consists of: a 2mm thick galvanized steel outer shell, a 50mm thick damping sound insulation layer (composed of high-density damping rubber and EPDM foam), an 80mm thick centrifugal glass sound-absorbing cotton layer, and a 1mm thick microporous aluminum plate layer as the interior surface. This multi-layered composite structure effectively absorbs and isolates the mid-to-high frequency noise generated during equipment operation. A forced air intake duct 610 is located on the lower side wall of the cabin 600, with an insect screen and a primary filter installed at its inlet; a forced exhaust duct 620 is located at the top, containing a low-noise axial flow fan to expel hot air from the cabin 600. The exhaust outlet of the forced exhaust duct 620 is connected to the radiator of the energy recovery unit 500, drawing waste heat into the workshop.

[0063] The positive pressure subsystem 100 includes two screw air compressors 110 (one primary and one backup) and a 10-cubic-meter pressure-stabilized air receiver 120. The screw air compressors 110 employ permanent magnet variable frequency drive technology, automatically adjusting their speed according to air consumption. Each air compressor 110 is equipped with a high-sensitivity vibration sensor (piezoelectric accelerometer), a PT100 temperature sensor, and a Hall current sensor for real-time monitoring of its operating status. The air compressor 110's inlet is equipped with a pre-filter 130 (G4 grade plate filter) to filter large particles of dust and insects from the air. The air compressor 110's outlet is connected to the inlet of the pressure-stabilized air receiver 120 via piping. The receiver 120 is equipped with a pressure sensor and a safety valve to stabilize and buffer compressed air pressure fluctuations. An automatic drain valve is located at the bottom of the receiver 120 to drain condensate.

[0064] The negative pressure subsystem 200 includes two dry screw vacuum pumps 210 (one main and one standby) and a 5-cubic-meter vacuum buffer tank 220. The dry screw vacuum pumps 210 also employ permanent magnet variable frequency drives and operate without oil in their pump chambers, ensuring that the generated negative pressure gas is clean and oil-free. Each vacuum pump 210 is also equipped with a vibration sensor, a temperature sensor, and a current sensor. The inlet of the vacuum buffer tank 220 is connected to the purification unit 300 via a pipeline, and its outlet is connected to the negative pressure gas-using equipment in the workshop via a main pipe. The vacuum buffer tank 220 is also equipped with a pressure sensor and an automatic drain valve.

[0065] The purification unit 300 is divided into a positive pressure purification branch and a negative pressure purification branch.

[0066] Positive pressure purification branch: Connected between the outlet of the pressure-stabilizing air storage tank 120 and the workshop's positive pressure air supply main. Its processing flow is as follows: First, the compressed air passes through a refrigerated air dryer 310, cooling it to 2-5℃, causing most of the water vapor to condense into liquid water and be discharged, reducing the pressure dew point to below 3℃. Then, it passes through a multi-stage precision filtration assembly 320, which includes: a first stage cyclone separator 321 for separating larger droplets and particles; a second stage condenser filter 322 (filtration accuracy 1μm) for condensing and separating oil mist and fine water mist; a third stage activated carbon filter 323 (filtration accuracy 0.01μm) for adsorbing oil vapor and odors; and a fourth stage high-efficiency oil removal filter 324 (filtration accuracy 0.01μm, residual oil content ≤0.01mg / m³), ensuring that the final output compressed air meets the Class 0 oil-free standard.

[0067] Negative pressure purification branch: Connected between the workshop's negative pressure return main pipe and the inlet of the vacuum buffer tank 220. Its core component is a self-cleaning pulse backflushing filter 330. The filter 330's housing contains multiple filter cartridges made of oil- and water-resistant polyester fiber, with a filtration accuracy of 3μm. The clean air chamber of the filter 330 is connected to the vacuum buffer tank 220; dust-laden gas enters from the outside, and dust is trapped on the outer surface of the filter cartridges. A differential pressure sensor is installed on the filter 330. When the differential pressure reaches a set value (e.g., 1000Pa), the intelligent control unit 400 activates the pulse backflushing system, using compressed air to instantly backflush the filter cartridges, blowing off paper fibers, dust, and other impurities adhering to the surface into the dust collection hopper, achieving automatic cleaning. Furthermore, after the self-cleaning filter 330, a primary high-efficiency vacuum filter 340 (filtration accuracy 0.1μm) is connected in series to further protect the vacuum pump.

[0068] The energy recovery unit 500 is one of the core innovations of this invention. It mainly includes a plate heat exchanger 510, a circulating pump 520, an energy distribution module 530, and related pipelines and control valves.

[0069] Heat exchanger 510: Its high-temperature side inlet is connected to the oil-gas separator outlet of screw air compressor 110 via a pipeline (the compressor oil temperature here is usually 80-95℃), and its high-temperature side outlet is connected to the original cooling system inlet of air compressor 110, forming a closed loop. The low-temperature side is an independent closed water circulation system, driven by circulation pump 520.

[0070] Energy distribution module 530: Its inlet is connected to the low-temperature side outlet of heat exchanger 510. The module contains an electrically operated three-way regulating valve that divides the hot water into two branches. The first branch connects to the preheating jacket 540 wrapped around the pump body of the dry screw vacuum pump 210. In winter or during cold starts of the vacuum pump, preheating the vacuum pump 210 with hot water allows it to quickly reach its optimal operating temperature, reducing start-up wear and operating viscosity resistance. The second branch connects to fan coil units or radiators 550 installed in the workshop for heating the workshop environment. In addition, hot air discharged from the forced exhaust duct 620 of the engine compartment 600 is also introduced into the workshop for further utilization of waste heat. Temperature sensors and flow control valves feed real-time data back to the intelligent control unit 400, which dynamically adjusts the hot water distribution based on the vacuum pump inlet temperature and the workshop temperature requirements.

[0071] In this embodiment, the energy recovery unit 500 and the intelligent control unit 400 work together to form an intelligent thermal energy management system. When the intelligent control unit 400 obtains the production plan from the MES system and predicts an upcoming high-volume production task, it calculates the optimal preheating temperature that the vacuum pump 210 needs to reach in advance using a feedforward control model. Subsequently, it controls the electric three-way valve of the energy distribution module 530 to preferentially guide the heat transfer medium to the preheating jacket 540. At the same time, it controls the flow rate of the heat transfer medium by adjusting the speed of the circulating pump 520, so that the vacuum pump 210 reaches and stabilizes at the preset optimal operating temperature (e.g., 45±2℃) 10 minutes before the start of the production task. This "predictive preheating" strategy ensures that the vacuum pump is in its most efficient operating state when put into high-load production, avoiding energy consumption and wear during the cold start phase. When the workshop ambient temperature sensor detects that the workshop temperature is below 18℃, the system will, through the energy distribution module 530, guide all the remaining heat to the workshop radiator 550 while ensuring the basic preheating requirements of the vacuum pump, maintaining the comfort of the workshop environment. If the workshop temperature has reached the target, excess heat can be dissipated through a bypass or cooling tower (not shown in the figure). This energy allocation strategy, based on global optimization rather than local optimization, is another manifestation of the synergistic effect of this invention.

[0072] The intelligent control unit 400 is the brain of the system, including a data acquisition module 410, a main control PLC 420, a human-machine interface (HMI) 430, and a remote communication module 440.

[0073] Data acquisition module 410: Collects data from all sensors (pressure, flow, temperature, vibration, current, dew point, dust concentration) via Modbus RTU / TCP protocol.

[0074] Main control PLC 420: Utilizes a Siemens S7-1500 series high-performance PLC. It has advanced internal control algorithms. Dual-mode control strategy: On the one hand, by reading data from the workshop's MES system or manually inputting printing and binding production plans, a feedforward control model is used to predict the gas demand for the next 1-4 hours, and the number of air compressors 110 and vacuum pumps 210 and the operating frequency of the frequency converter are adjusted in advance. On the other hand, by collecting data from pressure sensors (positive pressure accuracy ±0.5kPa, negative pressure accuracy ±0.2kPa) and flow sensors on the main gas supply line, a feedback control model (PID algorithm) is used for real-time fine-tuning to ensure a high degree of stability in gas supply pressure and flow.

[0075] Predictive maintenance module: Continuously records and analyzes data such as vibration, temperature, and current. For example, when the energy of a vibration sensor continuously rises in a specific frequency band, or when the current energy efficiency of a device is less than 15% of its historical average, the system will automatically identify a potential fault and generate a maintenance work order on the HMI 430 that includes the fault type, possible causes, and handling suggestions. At the same time, it will send an SMS or APP notification to the maintenance engineer via the remote communication module 440.

[0076] Human-Machine Interface 430: A 15-inch industrial-grade touch screen that displays system flowcharts, operating parameters of various devices, energy consumption statistics reports, alarm records, etc. in real time, and supports operations such as parameter setting, manual start and stop, and maintenance mode switching.

[0077] Remote communication module 440: Uploads system operation data to the cloud server via 4G / 5G or industrial Ethernet to achieve remote monitoring, data analysis and fault diagnosis.

[0078] In a specific application scenario, the intelligent control unit 400 demonstrates its powerful collaborative control capabilities. Suppose the MES system has just updated its production plan, moving a batch of high-grammage, thick paper printing tasks originally scheduled to start at 2 PM to 10 AM. After detecting this change through its feedforward control model, the intelligent control unit 400 immediately recalculates the gas load curve for the next four hours. It discovers that printing high-grammage paper requires stronger negative pressure adsorption. Therefore, it executes the following series of collaborative operations: 1) Adjusting the predicted operating frequency of vacuum pump 210 and starting the backup vacuum pump in advance to a low-speed standby state to cope with the upcoming peak load. 2) Sending instructions to the energy recovery unit 500 to distribute more high-temperature heat transfer medium to the preheating jacket 540 of vacuum pump 210, ensuring that the pump body temperature of vacuum pump 210 is raised to its optimal operating point before 10 AM to achieve maximum efficiency during peak loads. 3) Adjust the operating configuration of air compressor 110 to pre-charge the pressure of pressure-stabilizing air storage tank 120 to a slightly higher level than usual to cope with the potential increase in positive pressure air demand. 4) Update the predicted energy consumption curve on HMI 430 and automatically send the updated data to the energy management module. Through this series of proactive and coordinated automatic adjustments, the system was fully prepared for the 10:00 AM peak, with stable air supply pressure and no fluctuations. All equipment operated within its high-efficiency range, fully demonstrating the advanced nature of the intelligent control unit and the excellent performance brought by synergistic efficiency.

[0079] The emergency backup unit includes a backup air compressor connected in parallel with the main air compressor and a backup vacuum pump connected in parallel with the main vacuum pump. When the main equipment fails, the air supply pressure falls below the lower limit, or the main equipment is under maintenance, the intelligent control unit 400 will automatically or manually (via HMI) activate the corresponding backup equipment to ensure uninterrupted air supply to the workshop and achieve seamless switching.

[0080] A brief description of the system's working process: After the system starts, the intelligent control unit 400 first predicts the air load based on the production plan and ambient temperature using a feedforward control model, and then determines the number of air compressors 110 and vacuum pumps 210 to start. Air compressor 110 begins operation, generating a high-temperature, high-pressure oil-air mixture. After passing through an oil-air separator, the high-temperature oil enters the heat exchanger 510 of the energy recovery unit 500 to heat the circulating water. The cooled lubricating oil returns to the air compressor to continue cooling the compression chamber. Simultaneously, compressed air enters the air storage tank 120 for pressure stabilization, and then passes through a refrigerated dryer 310 and a multi-stage precision filter assembly 320 to become high-quality clean compressed air, which is then delivered to the positive pressure air consumption terminal in the workshop.

[0081] Vacuum pump 210 operates, generating a stable negative vacuum at the workshop's negative pressure gas terminal via vacuum buffer tank 220 and negative pressure purification branch (self-cleaning filter 330, high-efficiency vacuum filter 340). The drawn-in dust-laden gas first passes through self-cleaning filter 330 to remove paper dust, then undergoes further purification through high-efficiency filter 340, and finally enters vacuum pump 210 before being discharged. The discharged gas may contain trace amounts of heat.

[0082] The energy recovery unit 500 recovers hot water from the air compressor 110. Part of this water is used to heat the vacuum pump 210 via the preheating jacket 540, improving its operating efficiency; the other part is used to heat the workshop via the workshop radiator 550 and the engine room exhaust fan 620. The intelligent control unit 400 dynamically adjusts the operating frequency, start / stop status, and energy distribution ratio of the equipment based on real-time data and predictive models, ensuring that the entire system operates in the most economical, stable, and efficient manner.

[0083] Through the aforementioned systematic technical solution, this invention not only achieves the physical integration of various functional units, but more importantly, it achieves deep coupling and synergistic optimization of them at the levels of energy flow, material flow, and information flow. The synergy between the energy recovery unit and the intelligent control unit transforms waste heat utilization from passive and extensive to proactive and precise; the synergy between the purification treatment unit and the negative pressure subsystem fundamentally solves the industry-wide problem of paper lint clogging; and the synergy between the dual-mode control strategy and the predictive maintenance module transforms equipment operation and maintenance from passive response to proactive prediction.

[0084] In summary, the positive and negative pressure centralized gas supply system for printing and binding workshops provided by this invention effectively solves the problems of poor workshop environment, high energy consumption, low gas quality, and difficult maintenance and management in the prior art through highly integrated structural design, multi-stage purification quality assurance, tiered energy recovery, and intelligent collaborative control.

[0085] The implementation principle of this invention is as follows: This invention discloses a centralized positive and negative pressure gas supply system for printing and binding workshops, belonging to the field of printing gas supply technology. This invention aims to solve the problems of low integration, high energy consumption, and poor gas quality in existing gas supply systems. The system includes: a positive pressure subsystem 100, a negative pressure subsystem 200, a purification unit 300, an intelligent control unit 400, and an energy recovery unit 500. The energy recovery unit 500 recovers the compression heat generated by the positive pressure subsystem 100 for preheating the negative pressure subsystem 200 or for workshop heating. The purification unit 300 employs multi-stage precision filtration and self-cleaning pulse backflushing technology to ensure gas supply quality. The intelligent control unit 400 incorporates a dual-mode control strategy and a predictive maintenance module to achieve optimized system operation and intelligent management. Through high integration and energy cascade utilization, this invention significantly reduces system energy consumption and workshop noise, improves gas supply quality and equipment operational reliability, and provides an energy-saving, environmentally friendly, and efficient centralized gas supply solution for printing and binding workshops.

[0086] In summary, the technical solutions claimed in this application are not isolated in their various technical features. Instead, they are organically integrated into a whole through technologies such as energy cascade utilization, multi-stage deep purification, and intelligent predictive control, collectively solving long-standing technical problems in the prior art. In particular, the combination of the energy recovery unit and the preheating function of the negative pressure subsystem, the targeted design of the self-cleaning pulse backflush filter for negative pressure purification, and the synergy between the feedforward-feedback dual-mode control strategy and the predictive maintenance module are all features that cannot be achieved through simple combinations of existing technologies. Their interaction and mutual support produce a synergistic effect of "1+1>2," bringing unexpected technical benefits and resulting in a qualitative leap in the energy efficiency, stability, reliability, and intelligence of this system.

[0087] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A centralized positive and negative pressure air supply system for a printing and binding workshop, characterized in that, include: Positive pressure subsystem (100) is used to generate and output compressed air; The negative pressure subsystem (200) is used to generate and output a vacuum negative pressure; The purification unit (300) is connected to the positive pressure subsystem (100) and the negative pressure subsystem (200) respectively, and is used to perform multi-stage purification treatment on compressed air and vacuum negative pressure gas; The intelligent control unit (400) is electrically connected to the positive pressure subsystem (100), the negative pressure subsystem (200) and the purification treatment unit (300) to realize the automated operation and optimized control of the system; as well as An energy recovery unit (500) is connected to the positive pressure subsystem (100) and the negative pressure subsystem (200) for recovering the compression heat generated during the operation of the positive pressure subsystem (100) and using at least a portion of the recovered heat energy for preheating the negative pressure subsystem (200) or for environmental heating of the workshop.

2. The positive and negative pressure centralized air supply system for a printing and binding workshop according to claim 1, characterized in that, The energy recovery unit (500) includes: A heat exchanger (510) has its high-temperature side inlet connected to the oil-gas separator outlet of the positive pressure subsystem (100); A circulating pump (520) is connected to the low-temperature side of the heat exchanger (510); An energy distribution module (530) has its inlet connected to the low-temperature side outlet of the heat exchanger (510), and its outlet includes at least a first branch and a second branch. The first branch is connected to the preheating jacket (540) installed on the negative pressure subsystem (200), and the second branch is connected to the workshop radiator (550) installed in the workshop.

3. The positive and negative pressure centralized air supply system for a printing and binding workshop according to claim 1, characterized in that, The purification unit (300) includes: A refrigerated air dryer (310) and a multi-stage precision filter assembly (320) are installed on the outlet pipe of the positive pressure subsystem (100); and A self-cleaning pulse backflush filter (330) is installed on the inlet pipe of the negative pressure subsystem (200).

4. The positive and negative pressure centralized air supply system for a printing and binding workshop according to claim 3, characterized in that, The multi-stage precision filtration assembly (320) includes a cyclone separator (321), a coagulating filter (322), an activated carbon filter (323), and a high-efficiency oil removal filter (324) connected in sequence.

5. A centralized positive and negative pressure air supply system for a printing and binding workshop according to claim 1, characterized in that, The intelligent control unit (400) includes: The data acquisition module (410) is used to acquire real-time data from each sensor; The main control PLC (420) has a built-in dual-mode control strategy, which includes a feedforward control model based on gas demand prediction and a PID control model based on real-time pressure feedback. Human-computer interaction interface (430); and Remote communication module (440).

6. A centralized positive and negative pressure air supply system for a printing and binding workshop according to claim 5, characterized in that, The main control PLC (420) also has a built-in predictive maintenance module, which is used to perform equipment health assessment and fault warning based on the historical data trends of vibration sensors, temperature sensors and current sensors installed on the positive pressure subsystem (100) and negative pressure subsystem (200).

7. The positive and negative pressure centralized air supply system for a printing and binding workshop according to claim 1, characterized in that, It also includes a soundproof and noise-reducing cabin (600) for accommodating the positive pressure subsystem (100) and the negative pressure subsystem (200); the inner wall of the soundproof and noise-reducing cabin (600) is provided with a damping sound insulation layer, a sound-absorbing cotton layer and a microporous aluminum plate layer in sequence.

8. A centralized positive and negative pressure air supply system for a printing and binding workshop according to claim 7, characterized in that, The soundproof and noise-reducing cabin (600) is provided with a forced ventilation duct (620), which is connected to the workshop radiator (550) of the energy recovery unit (500).

9. A centralized positive and negative pressure air supply system for a printing and binding workshop according to claim 1, characterized in that, It also includes an emergency backup unit, which includes a backup air compressor connected in parallel with the positive pressure subsystem (100) and a backup vacuum pump connected in parallel with the negative pressure subsystem (200).

10. A centralized positive and negative pressure air supply system for a printing and binding workshop according to claim 1, characterized in that, The positive pressure subsystem (100) includes a permanent magnet variable frequency screw air compressor (110) and a pressure-stabilized air storage tank (120); the negative pressure subsystem (200) includes a permanent magnet variable frequency dry screw vacuum pump (210) and a vacuum buffer tank (220).

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