Daily Maintenance Guide for Laminar Flow Transfer Windows: Ensuring a Clean Environment and Stable Operation of Equipment Laminar flow transfer Windows, as the core “isolation transfer equipment” between cleanrooms and non-clean areas as well as regions of different cleanliness levels, their sealing performance, filtration efficiency and air flow organization directly affect the overall cleanliness of the cleanroom. Proper daily maintenance not only extends the service life of equipment but also avoids the risk of cross-contamination. It is suitable for scenarios with strict cleanliness requirements such as pharmaceutical, electronic, food, and biological laboratories. The following are detailed key points for daily maintenance: I. Daily Inspection: Basic status Confirmation (Every 10 minutes, at least once per shift) Appearance and seal inspection Check whether the transfer window box and door body are deformed, scratched or damaged, and whether the glass window is clean without stains or cracks to ensure a clear view. Verify the double-door interlock function: After closing one side door, try to open the other side door to confirm that they cannot be opened simultaneously (when the interlock fails, it should be immediately deactivated to avoid pressure difference imbalance in the clean area). Check the door sealing strip: Touch the sealing

I. Daily Basic Maintenance (Daily Mandatory) 1. Cleaning and disinfection standards Cleaning scope: Interior of the cavity (countertop, four walls, corners), contact surfaces of the door body, door handles, gaps of the sealing strips, and external surfaces can be wiped as needed. ​ Cleaning process First, use a lint-free cloth dipped in 75% medical alcohol to wipe and remove microorganisms and stains (high-risk scenarios such as biological laboratories need to be cleaned every shift). ​ Use a soft-bristled brush and neutral detergent to scrub the dust in the gaps of the sealing strip, then dry it with a dry cloth to prevent moisture and aging. ​ Dust in the interlock sensing area should be blown off with compressed air at a pressure of 0.3 to 0.5MPa to prevent signal obstruction. ​ Precautions: Do not rinse with water, do not use chlorine-containing disinfectants (corrosive to metals), and do not use hard objects such as steel wool balls (to avoid scratches on stainless steel). ​ 2. Function check before startup Power supply status: Confirm that the power supply is stable and the voltage meets the equipment requirements (to avoid F06 failure); ​ Door interlock test: Verify that both doors cannot be opened

Horizontal Flow Workbench Core Component Replacement Judgment Guide: From Inspection Standards to Practical Operation Methods The core components of the horizontal flow workbench (HEPA/ULPA filters, fans, control panels, workbenches and seals) directly determine the purification effect and operational stability. Their replacement should be comprehensively judged based on performance test data, aging performance and industry standards, rather than simply relying on the service life. The following are the specific judgment methods, testing standards and replacement thresholds for each core component, taking into account both professionalism and practicality: I. Judgment Criteria for Core Component Replacement (Sorted by Priority) HEPA/ULPA filter (purification core, highest priority) As a key component for ensuring cleanliness, the failure of the filter directly leads to the equipment’s inability to meet the usage requirements. The following judgment criteria should be given special attention: (1) Performance testing and judgment (quantitative standards Wind speed detection: Use a hot sphere anemometer to evenly take 5 to 9 measurement points on the working surface of the workbench (in accordance with ISO 14644-3 standard). If the average wind speed is ≤0.25m/s (the normal working wind speed range is 0.3-0.5m/s), and it still cannot be restored after cleaning the pre-filter and adjusting the fan speed,

I. Reference for the core service life of the entire Machine The reasonable service life of the horizontal flow workbench (including the ultra-clean type) as a whole is 5 to 10 years. This range is based on regular usage scenarios (4 to 8 hours of operation per day, placement in a clean environment, and standardized maintenance), and can be specifically divided into: Laboratory-grade equipment (intermittent use) : Its lifespan is mostly 8 to 10 years, and can be extended to over 10 years if properly maintained. ​ Industrial-grade equipment (24-hour continuous operation, high-pollution scenarios) : Its lifespan is typically 5 to 8 years, and it requires more frequent maintenance to prevent premature aging of components. ​ High-demand scenarios (pharmaceutical GMP workshops, microelectronics clean areas) : It is recommended to conduct a comprehensive performance assessment every five years to ensure compliance with clean standards before continuing to use. ​ Ii. Service Life of Core Components (Determining the service Cycle of the Entire Machine) The lifespan of the entire machine is essentially determined by the wear and tear of key components. The replacement cycles and influencing factors of each core component are as follows: Component type Theoretical service life Actual influencing factors

I. Core Working Logic: Four major links operate in a closed loop The essence of the automatic double-door goods shower is an “intelligent air lock purification system”. Through a closed-loop process of induction control → air flow purging → interlock isolation → air circulation, it efficiently removes contaminants from the surface of goods and simultaneously blocks the air convection between the clean area and the non-clean area. The specific process is as follows: Induction trigger stage: Contactless automatic start Trigger mechanism: The door bodies on both sides of the equipment are equipped with 2 sets of infrared sensing probes (with a detection distance of up to 1.5 meters). When forklifts, AGVs, or goods approach the entrance by about 1 meter, the probes respond quickly (triggered within 0.5 seconds), and the sliding door is driven to open to both sides through the PLC control system. ​ Adaptive design: The sensing range can cover large-sized goods (width ≤3 meters, height ≤4 meters). Some models support the adjustment of sensing sensitivity to prevent false triggering of small auxiliary material vehicles or missed triggering of large goods. ​ Interlocking isolation stage: Blocking cross-contamination Double-door interlock logic: It adopts an electronic electromagnetic lock interlocking design,

I. Food and Beverage Industry: The “First Line of Defense” for Food Safety As one of the most widely applied fields, the core adaptation needs to meet the scenarios of the GB 14881 food safety standard, focusing on solving the contamination problems of raw materials, semi-finished products, and packaging materials: Typical scenarios: entrance of baking food processing area, buffer channel of dairy filling line, raw material transfer port of candy and chocolate workshop, storage connection point of can packaging area, drinking water bottle preform conveying line. ​ Application core: Through high-speed clean air flow of 25-35m/s, it removes floating dust and fibers from the surface of raw materials (such as flour, sugar grains, nuts), reduces the growth of microorganisms (total bacterial count, mold), and prevents cross-contamination. For instance, at the entrance of the filling mixing room in a certain biscuit factory, an ISO 7-level material spray room is adopted to ensure that the cream and nut raw materials are not contaminated during the transmission process. ​ Special adaptation: For foods that are prone to moisture absorption, some product showers are equipped with dehumidification functions to prevent condensation during the air shower process, which could affect product quality. ​ Ii. Pharmaceutical

Maintenance and replacement cycle of nuclear power plant air purification system: Scientific control plan under safety orientation The maintenance and replacement cycle of the air purification system in nuclear power plants is mainly formulated around three dimensions: “nuclear safety priority, pollutant load, and equipment operating conditions”. It is necessary to strictly follow international nuclear safety standards (such as ASME AG-1, ISO 16890) and domestic norms (GB/T 25898, HAF series), and ensure the filtration efficiency. It is also necessary to avoid the risk of radioactive leakage. The following are the maintenance contents, replacement cycles and core control principles of system disassembly, which take into account both professionalism and practicality, and are suitable for content creation scenarios: I. Core filter replacement cycle: Hierarchical control, mainly based on parameter early warning The filter replacement cycle is not a fixed value and needs to be dynamically adjusted in combination with “differential pressure monitoring, radiation dose, and operating condition type”. The following is a common industry benchmark (specifically subject to the nuclear power plant operation and maintenance manual) : Filter type Replacement cycle under normal working conditions Special working conditions (accidents/high pollution) Core determination index Coarse filter (G1-G4) Three to six months 1 to 3

Analysis of Core Equipment for Air Purification in Nuclear Power Plants: Selection and Application of Air Filters As a high-safety-level energy facility, the air purification system of a nuclear power plant is directly related to nuclear safety, the stable operation of equipment, and the health of personnel. It is necessary to adopt a combined solution of “multi-stage filtration + functional segmentation” to address complex pollutants, including radioactive aerosols, harmful gases, and dust particles. The following are the types, functions, and application scenarios of core air filters in nuclear power plant air purification, which are explained in combination with industry standards and technical characteristics: I. Pre-treatment filters: Coarse/medium efficiency filtration, the first line of defense Coarse filter (G1-G4 grade, EN 779 standard) Core function: Intercept large particles of dust (≥5μm), hair, fibers, and other impurities in the air, prevent premature clogging of subsequent high-precision filters, extend their service life, and reduce system operating costs. Filter materials: Commonly used are polyester fibers, non-woven fabrics, metal meshes, etc. In some working conditions, flame-retardant materials are selected (to meet the fire protection requirements of nuclear power plants). Application scenarios Pre-treatment of intake air for the ventilation system in conventional areas of nuclear power plants

As the “core power source” of the cleanroom air purification system, the FFU (Fan Filter Unit) directly determines the stability of the clean environment, the service life of the equipment, and the energy consumption during operation by the degree of refinement in its daily operation and maintenance. Based on Bailun Purification’s practical experience in the new energy, medical, food, and other industries, this paper sorts out the key details of the daily operation and maintenance of FFUs from four dimensions: inspection and monitoring, cleaning and maintenance, safety control, and industry adaptation, to help enterprises achieve long-term and efficient operation of equipment. I. Inspection and Monitoring: Precise Control of Operating Status (Core of Data-driven Management) Check the details every day. Visual monitoring of operation status: Observe whether the indicator lights on the control panel (power, operation, and fault lights) are normal. The sound of the fan should be stable without any abnormal noise (normal noise ≤65dB (A)). If abnormal noise or excessive vibration (amplitude > 0.1mm) occurs, stop the machine immediately for inspection (focus on checking dust accumulation on the impeller and wear of the motor bearings). Key parameter record: Accurately record the pressure difference before and after the filter (the

I. Preparations Before Operation (Safety Prerequisites) Environmental inspection Confirm that the FFU installation area is free of obstacles, flammable materials, and corrosive gases. The ground/installation surface should be flat and stable, and there should be no personnel or irrelevant equipment left around. Check that the working environment is well-ventilated. The clean area must be cleaned in advance to prevent dust from entering the FFU air duct and compromising the filtration effect. Equipment inspection Appearance: Check that the FFU housing is not deformed or damaged, the connecting bolts are tight, the pre-filter is installed in place without looseness, and the air outlet is not blocked. Circuit: Check that the insulation layer of the power cord is not damaged or aged, that the plug/terminal block is firmly connected, that the grounding (PE line) is reliable, and that there are no exposed wires. Functional components: Confirm that the fan impeller is not stuck (manually gently turning the impeller should ensure smooth rotation), the buttons and indicator lights on the control panel are in good condition, and the speed control knob (if any) has a clear position. Personnel preparation Operators must be familiar with the working principle of FFU and this guide, and wear

1. Daily maintenance Regular inspection: Check the operating status of the filter every day, observe the reading of the differential pressure gauge, and record the trend of differential pressure changes. Clean the surrounding environment: Keep the installation area of the filter and the interior of the air duct clean to avoid dust accumulation that may affect the filtration effect. Leak detection test: Conduct a PAO leak detection test on the filter every quarter to check for any leakage. If leakage is found, it should be repaired or replaced in a timely manner. 2. Replacement cycle Regular replacement: When the pressure difference of the filter reaches twice the initial pressure difference or exceeds 500Pa, it needs to be replaced in a timely manner. Regular replacement: Even if the pressure difference has not reached the upper limit, it is necessary to replace it regularly according to the usage conditions (usually 6-12 months, and 3-6 months under harsh conditions). Special circumstances replacement: When the filter is damaged, deformed or fails the leak test, it must be replaced immediately. 3. Replacement precautions When replacing, the relevant air supply system should be turned off, and clean gloves, masks and other protective equipment should be worn

The industrial coating workshop plays a vital role in both protecting and beautifying product surfaces. The quality of coating directly affects corrosion resistance, appearance accuracy, and product longevity. Throughout the coating process, dust and particulate pollutants are critical hidden dangers that jeopardize coating quality. When particles in the air attach to the workpiece surface or mix into the coating, defects such as pinholes, particles, and sagging can occur, thereby increasing rework rates and production costs. Moreover, certain coating methods—such as electrostatic spraying and electrophoretic coating—demand extremely high environmental cleanliness: for example, no more than 1000 particles larger than 0.5μm per cubic meter of air (Class 7 standard). To create this controlled environment, pleated high-efficiency filters (H13-H14 grade, ≥99.97% efficiency for 0.3μm particles) are used in the clean air system due to their stable airflow resistance and large dust holding capacity. I. Core Function and Filtration Principle 1. Core function Purify the intake air: Filter the fresh air and recirculated air entering the painting workshop to remove contaminants such as dust, fibers, and oil particles, preventing contamination of the workpieces to be coated and the paint. Ensure process stability: Provide a consistent, clean air environment for key processes, such as spraying