Basic Properties and Core Functions
Core Function: As the "rib" of the filter bag, it supports the filter bag to maintain a stable shape during filtration and ash cleaning processes, prevents the filter bag from
collapsing and deforming, avoids damage to the filter bag caused by air flow impact, and disperses the mechanical stress of ash cleaning at the same time,
so as to extend the service life of the filter bag.Mainstream Materials: It is formed by welding high-quality low-carbon steel wire, galvanized steel wire or stainless steel
wirewith the commonly used steel wire diameter ranging from 2.7mm to 4.5mm.
Surface Treatment Processes:
Galvanizing: Suitable for normal-temperature dry working conditions, with low cost but weak acid and alkali resistance
Powder coating: Its comprehensive performance is between that of galvanizing and silicone coating, and it imposes higher requirements on the welding process
Silicone spraying: Resistant to high temperature and high humidity, suitable for highly corrosive working conditions such as coal-fired boilers and waste incineration
Application Fields: Widely used in industrial dust removal scenarios including metallurgy, building materials, power generation, chemical industry, steel
cement, mines and other sectors.
Structural Parameters and Specification Standards
Geometric Dimensions: The conventional diameter range of the cage is Φ70mm ~ Φ200mm, with a length covering 0.5m to 10m. The mainstream Φ133 series has a
length of 1~4m, and the Φ160 series has a length of 2~6m.
Rib Configuration: The number of longitudinal ribs can be customized from 6 to 24. The conventional spacing of transverse rings is 150mm ~ 200mm, which can be
encrypted to 100mm according to specific working conditions.
Geometric Tolerance Requirements: The verticality error of a 6-meter-long cage shall be controlled within ±1mm, and cages with a length exceeding 3m shall be
equipped with an integrally formed steel Venturi tube.
Structural Types: Common shapes include round, oval, trapezoidal and envelope-shaped, supporting multiple assembly structures such as one-piece type,
two-section/three-section split type, bottom-discharging type and plug-in type.
Core Selection Criteria
The selection should not only focus on the material thickness, but also match the working conditions from multiple dimensions:
Dimension Matching Principle: The outer diameter of the cage is 5~8mm smaller than the inner diameter of the filter bag, and the total length of the cage is 10~20mm
shorter than the filter bag, which not only facilitates installation and disassembly, but also reserves allowance for thermal shrinkage of the filter bag.
Working Condition Adaptation Logic:
Normal-temperature dry dust: Ordinary galvanized cages can meet the requirements
High-temperature, high-humidity and corrosive scenarios: Silicone-coated cages are preferred
Working conditions with highly abrasive dust: 304 stainless steel cages are selected, and the number of longitudinal ribs is properly increased
Cleaning Method Adaptation: Pulse-jet dust removers shall be equipped with cages with Venturi tubes to optimize air flow distribution, while mechanical rapping dust
removers preferentially adopt trapezoidal high-strength cages.
Common Faults and Operation & Maintenance Points
Typical Fault Causes:
Residual burrs at welding spots: Continuously scratches the inner wall of the filter bag during operation, forming long-strip-shaped bag breakage
Excessive verticality deviation: Causes uneven local stress on the filter bag, which greatly accelerates the wear rate of the bottom
Mismatched dimensions: Excessive gap between the cage and the filter bag leads to excessive swinging of the filter bag during ash cleaning, resulting in fatigue damage
Installation and Maintenance Specifications:
Inspect the surface of each cage one by one before installation to ensure there is no unwelded joint, virtual weld or sharp protrusion
Lower the cage vertically and slowly during installation. It is strictly forbidden to force it against the filter bag to avoid scratching the fiber layer of the filter material
Every 2000 hours of operation, use an endoscope to focus on checking the wear of the filter bag in the area corresponding to the welding seam of the cage, and replace
rusted and deformed cages in time.
