Medium-efficiency bag filters are devices that use high-efficiency filter materials (such as synthetic fibers or glass fibers) to create filter bags for medium-level air filtration. Their working principle is based on inertial impaction, diffusion adsorption, and electrostatic effects.

01 Core Definition and Working Principle

Inertial Impaction: Large dust particles, due to changes in airflow direction, collide with and are trapped by the filter bag fibers.

Diffusion Adsorption: Tiny particles (<0.1μm) come into contact with the fibers due to Brownian motion and are adsorbed.

Electrostatic Effect: The electrostatic charge on the filter material enhances its ability to adsorb dust, improving filtration efficiency.

This filter can capture dust particles of 1-5μm, with a filtration efficiency of 60%-95% (colorimetric method), suitable for medium-level filtration needs in central air conditioning systems, clean rooms, hospitals, and other applications.

02 Structural Characteristics and Advantages

Multi-bag design: Typically configured with 4-10 filter bags, the dust holding capacity is significantly higher than plate filters, suitable for environments with high dust concentrations.

8-10 bag structures offer lower resistance, with initial resistance controllable below 50Pa, extending system lifespan.

Material Selection: Filter media: Composite non-woven fabric, imported synthetic fiber, or glass fiber, balancing filtration efficiency and breathability.

Frame: Aluminum alloy, galvanized sheet, or cold-rolled steel with powder coating, strong corrosion resistance, suitable for humid environments.

Convenient Maintenance: Filter bags can be replaced individually, resulting in low maintenance costs; washable filter media (such as glass fiber) can be cleaned up to twice, extending service life.

During installation, ensure the filter bag opening is perpendicular to the ground to prevent filter media deformation from affecting filtration performance.

03 Application Scenarios and Industry Adaptability

Industrial Sector:

Electronics Manufacturing: Filtering clean room air to prevent micro-dust contamination of precision components such as chips and displays.

Pharmaceutical and Food: As a pre-filter for high-efficiency filters, reducing the load on subsequent equipment and ensuring the production environment meets GMP standards.

Chemical Industry: Used in conjunction with other purification equipment to remove large dust particles and reduce the difficulty of treating harmful gases.

Commercial and Public Sector: Office Buildings and Shopping Malls: Improving indoor air quality, reducing dust and odors, and enhancing customer comfort. Hospital Operating Rooms: Filters remove airborne pathogens (such as dust particles), reducing the risk of cross-infection and protecting the health of patients and medical staff.

Adaptation to Special Environments: Humid Environments: The filter bag structure effectively prevents moisture penetration, avoiding mold growth on the filter material. High

Airflow Scenarios: The multi-bag design disperses airflow impact, maintaining filtration stability.

04 Selection and Maintenance Guide

Selection Key Points:

Filtration Efficiency: Select F5 (40-50%) to F9 (99%) grades according to scene requirements.

Airflow Matching: Ensure that the resistance is ≤400Pa at the rated airflow to avoid excessive system energy consumption.

Size Customization: Standard sizes include 592mm×592mm×600mm (6 bags), 290mm×592mm×600mm (3 bags), etc., which can be adjusted according to the unit space.

Maintenance Cycle:

Use for 3-4 months under rated airflow.

Replace immediately when the resistance reaches above 400Pa.

In high dust environments, shorten the replacement cycle (e.g., every 1-2 months).

Regular Inspection: Check the surface of the filter bag every 2-4 weeks for blockage or damage, and clean up debris promptly.

Operating Precautions:

Avoid heavy objects impacting the filter bag surface to prevent damage to the filter material.

Ensure airtightness during installation to prevent airflow leakage affecting the filtration effect.