Filter bag cages, also known as dust collector cages or bag keels, are the structural support framework inside filter bags and one of the most important components of a baghouse dust collection system. Their primary function is to maintain the filter bag in its correct shape during filtration and pulse-jet cleaning, preventing bag collapse, excessive movement, and abrasion. A precisely manufactured cage not only extends filter bag service life but also ensures consistent airflow, low pressure drop, and stable dust collection efficiency.
Description
Filmedia® Customized Filter Bag Cages
The cage structure is optimized to provide uniform support, helping to maintain the filter bag’s shape and extend its service life.
- Manufactured using high-strength steel wire and fully automated resistance welding technology, the cages offer excellent straightness, dimensional accuracy, and mechanical strength.
- A variety of cage materials are available to suit different operating conditions.
- Each cage features a smooth surface free of burrs, sharp edges, or defective welds.
- Longitudinal wires are evenly distributed, with spacing tolerances controlled within ±2 mm.
Specifications
| Item | Typical Range |
|---|---|
| Cage Diameter | 80–300 mm |
| Cage Length | Customized |
| Vertical Wires | 5–24 |
| Ring Spacing | Customized |
| Shape | Round, Pleated, Oval, Flat, Trapezoidal |
| Material | Galvanized Steel, Carbon Steel, Stainless Steel, Titanium Alloy |
| Surface Finish | Epoxy Powder Coating, Organic Silicone Coating, Silicone Impregnation |
| Connection Type | One-piece, Two-piece, Multi-section |
| Applicable Temperature | Up to 500°C (depending on material and coating) |
Common Shapes of Filter Bag Cages
Round Filter Bag Cage
Designed for cylindrical filter bags, the most common type used in pulse jet baghouses. The support rings are available in both round and star-shaped designs. Star-shaped cages reduce the contact area between the cage and the filter bag, minimizing friction and extending bag life.
Pleated Filter Bag Cage
The pleated bag cage is a specialized type of cylindrical bag cage; it features support rings with a star-shaped (polygonal) design rather than the traditional circular ones, and is primarily used in pulse-jet bag dust collectors.
Oval Filter Bag Cage
Designed for oval filter bags used in compact baghouses where higher filtration area is required within limited space.
Flat Filter Bag Cage
Used for flat, envelope, panel, and rectangular filter bags. Common in specialized dust collection equipment with limited installation space.
Trapezoidal Filter Bag Cage
Suitable for trapezoidal filter bags commonly used in reverse air dust collectors and large industrial filtration systems.
Common Structural Designs
Number of Vertical Wires (Round Cage)
Number of Vertical Wires (Value Cage)
Bag Cage Tops
Bag Cage Bottoms
Split/Multi-Section Cages (For Long-Bag Filter Systems)
In large-scale long-bag pulse jet baghouses, filter bag lengths often exceed 6 meters or even 10 meters. To overcome shipping barriers, low overhead clearance in factories, and maintenance difficulties associated with excessively long single-section cages, a multi-section interlocking structure is deployed.
Guide Plate Join
The guide plate join uses precisely formed guide plates to align adjacent cage sections during assembly. This design provides accurate positioning, smooth insertion, and high concentricity, reducing installation time while maintaining excellent overall rigidity.、
Claw Join
The claw join features interlocking claws that securely connect cage sections without additional fasteners. The self-locking structure offers quick assembly, strong mechanical strength, and excellent vibration resistance, making it ideal for pulse-jet baghouses operating under frequent cleaning cycles.
Clamp Join
The clamp join connects cage sections using an external clamp or locking sleeve that tightly secures the joint. It provides high connection strength, easy maintenance, and convenient disassembly when replacement is required. This connection method is commonly used for large-diameter or heavy-duty filter bag cages.
Chuck Join
The chuck join employs a precision-machined locking mechanism that firmly fixes adjacent cage sections together while maintaining excellent alignment. The design offers outstanding stability, reliable load distribution, and secure operation under demanding working conditions.
Materials & Surface Treatments
01. Materials
Carbon steel offers high strength, good toughness, and cost-effective manufacturing. It is suitable for most industrial dust collection systems when combined with appropriate surface treatment.
Stainless steel cages provide outstanding corrosion resistance, oxidation resistance, and high-temperature performance. SUS316L is especially recommended for chemical processing, waste incineration, marine environments, and high-humidity applications.
Titanium alloy cages offer exceptional corrosion resistance, high strength-to-weight ratio, and outstanding durability in aggressive chemical and high-humidity environments. They maintain excellent mechanical properties at elevated temperatures while resisting acids, chlorides, seawater, and other highly corrosive media.
Electro-galvanizing forms a protective zinc layer that effectively prevents rust under normal operating conditions. It is an economical solution for dry and low-corrosion environments.
02. Surface Treatments
Electrostatic epoxy powder coating provides excellent resistance to acids and alkalis. It is suitable for many industrial applications but is less resistant to prolonged high temperatures and humid conditions.
Organic silicone coating offers excellent resistance to high temperatures, acids, and alkalis. It is widely used in high-temperature dust collection systems, although coating quality and adhesion are critical to long-term performance.
Silicone-impregnated cages provide additional protection against corrosion and moisture while maintaining smooth cage surfaces that reduce wear on filter bags.
Venturi Tubes
Filmedia® optimizes venturi tube structural design and combines high-performance materials to achieve a balance between filtration efficiency and energy consumption, delivering a highly efficient, energy-saving, and reliable solution for industrial dust control systems.
Application Industries
Filter bag cages are widely used in industrial dust collection systems across numerous industries.
- Power Generation: Coal-fired boilers and biomass boilers
- Cement Industry: Kilns, clinker coolers, and raw mills
- Iron & Steel: Blast furnaces, sintering plants, electric arc furnaces
- Chemical Processing: Powder handling, reactors, dryers, and conveying systems
- Mining & Non-Ferrous Metallurgy: Crushing, screening, smelting, and mineral processing
- Waste Incineration: High-temperature flue gas filtration
- Asphalt Mixing Plants: Aggregate drying and dust collection
- Carbon Black Production: Fine powder recovery
- Food Processing: Grain handling, flour milling, and bulk material transfer