The structural design of dust removal filter bags directly impacts their filtration efficiency and applicability. Based on cross-sectional shape, they can be categorized as:
- Round filter bags: The most common type, cylindrical in shape, specified by diameter × length (D×L). Their simple structure ensures uniform airflow distribution, suitable for most standard dust collectors.
- Flat filter bags: Including rectangular and trapezoidal shapes, specified by perimeter × length (P×L). Flat bags maximize filtration area in limited spaces, improving efficiency in compact dust removal systems.
- Special-shaped filter bags: Unconventional forms like star or polygonal shapes, designed for unique operational needs, with specifications based on specific structural parameters.
In terms of filtration modes, filter bags can be internally filtered or externally filtered:
- Internally filtered bags: Dusty gas enters from the inside, and dust is trapped on the inner surface. This design facilitates cleaning but requires regular maintenance to prevent internal dust accumulation.
- Externally filtered bags: Dusty gas enters from the outside, with dust adhering to the outer surface. Often paired with pulse-jet cleaning systems, external filtration offers more thorough dust removal, ideal for high-concentration dust environments.
Moreover, material and structural design must work in tandem. For instance, needle-punched felt or flocked filter fabrics, with their dense pore structures, can initiate sieving early in the filtration process without relying solely on dust layer formation. This design enhances efficiency, particularly for capturing fine, dry, non-fibrous dust.
Each structural type and filtration mode has its advantages and limitations. Selection should consider factors such as dust characteristics, equipment space, and cleaning methods to ensure the efficient and stable operation of dust removal systems.