The LCMD pulse jet bag filters manufactured by DARKO are key components of industrial air pollution control systems and improve environmental protection.

Causes and Solutions for Dust Filter Bag Detachment

Industrial dust collection systems widely use baghouse filters for their high filtration efficiency. However, many companies face problems with filter bags detaching during operation. Users often blame the bag manufacturers, but most detachment issues actually stem from improper dust collector design or installation. This article analyzes the root causes and provides practical solutions.

How Tube Sheet Holes Affect Bag Detachment

Key Functions of Tube Sheets

The tube sheet (or hole plate) is a critical component in baghouse filters. It serves two main purposes:

Separates the dirty gas chamber from the clean air chamber
Provides precise positioning for filter bag installation

Ideally, the bag’s snap ring should seal tightly in the tube sheet hole, ensuring all dirty air passes through filtration.

Impact of Hole Manufacturing Precision

Manufacturing Method	Edge Quality	Roundness Tolerance	Effect on Snap Ring	Detachment Risk
CNC Punching	Smooth	±0.5mm	Even force, full expansion	Low
Manual Cutting	Rough edges	±2mm+	Uneven expansion, stress points	High

Case Study: A cement plant had frequent bag detachment. Inspection revealed tube sheet holes were flame-cut with only basic grinding, showing up to 3mm roundness deviation. This caused oval snap ring expansion and poor sealing.

Two Main Causes of Bag Detachment

1. Tube Sheet Hole Precision Issues

Manufacturing Differences:
- Reputable manufacturers use CNC plasma cutting or precision dies
- Smaller shops may use manual cutting (torch/plasma cutting without finishing)
Edge Quality Problems:
- Burrs and uneven edges prevent full snap ring expansion
- Sharp edges can damage rubber snap rings
Roundness Deviation Effects:
- Snap rings expand into ovals instead of circles
- Creates uneven stress, leading to deformation over time

2. Incorrect Snap Ring Sizing (Less Common but Critical)

Though rare (~5% of cases), wrong sizing causes systemic detachment:

Snap ring too small → Won’t grip the hole
Snap ring too large → Hard to install or won’t expand fully

Expert Tip: Always test sample bags before mass production to verify fit.

Solutions: Full Process Control from Design to Installation

Design Phase Prevention

Precise Measurements:

Use digital calipers to measure hole diameters (minimum 4 points)
Record max/min values to calculate roundness error

Material Selection:

Choose elastic, aging-resistant rubber snap rings
For high temperatures, use silicone or fluororubber

Installation Quality Control

Pre-Installation Checklist:

Remove all burrs from hole edges (use fine sandpaper)
Check hole roundness (use roundness gauge)
Clean tube sheet surface (remove weld slag and dust)

Proper Tools:

Use specialized snap ring installation tools (no screwdrivers)
Apply even force (two-person installation recommended)

Post-Installation Tests:

Pull test: Apply 500N vertical force – displacement should be <2mm
Light test: Check for light leaks from clean air side

Optimizing Pulse-Jet Cleaning Systems

Modern Cleaning Technology

Pulse-jet baghouses use “dynamic filtration-cleaning”:

Compressed air (0.4-0.6MPa) creates shock waves
Venturi effect induces secondary airflow (5-8× primary flow)
Microsecond bag expansion (200-300g acceleration)
Inertial cleaning: Dust layer dislodges from reverse acceleration

Optimized Cleaning Parameters

Parameter	Standard Setting	Optimized Setting	Benefit
Air Pressure	0.5MPa	Adjust by filter material (0.3-0.7MPa)	Longer bag life
Pulse Width	0.1s	0.08-0.15s (shorter for thin media)	20% energy saving
Cleaning Interval	Fixed cycle	Differential pressure control (ΔP=1200-1500Pa)	Stable operation

Case Data: A steel mill switched to pressure-based cleaning, extending bag life from 18 to 30 months while cutting air use by 35%.

Key Design Principles for Baghouse Filters

1.Meet Emission Standards:

- Comply with GB16297 (China) or local regulations
- Special industries (welding, asbestos) need stricter controls

2.Dust Characteristics:

- Sticky dust: Use PTFE-coated filter media
- Fine dust: Choose gradient structure media

3.Gas Conditions:

- High temperature (>260°C): Fiberglass media + cooling
- High humidity: Insulation + anti-condensation design

4.Fluid Dynamics:

- Maintain 0.8-1.2m/s internal velocity
- Keep inlet/outlet ΔP <500Pa

5.Modular Design:

- Large units should have compartmentalized structure (e.g., 8 chambers × 128 bags)
- Online maintenance capability (isolate individual chambers)

6.Lifecycle Costs:

- Calculate energy use (fans, compressed air)
- Estimate maintenance (bag replacement cycles)

Performance Data by Industry

Based on 500+ installations, optimized systems achieve:

Parameter	Industry Standard	Optimized System	Requirements
Efficiency	>99%	>99.9%	Proper maintenance
Emissions	<30mg/m³	<10mg/m³	Membrane filter media
Bag Life	2 years	3-5 years	Correct selection + operation
Pressure Drop	<1500Pa	<1200Pa	Optimized cleaning

Typical Applications:

Steel: Converter gas treatment (<5mg/m³ emissions)
Cement: Kiln exhaust (4-year bag life)
Food: Flour collection (>99.99% efficiency)

Conclusion: A Systematic Approach

Filter bag detachment is fundamentally a system engineering challenge requiring solutions at three levels:

Equipment: Precise tube sheet machining (preferably CNC)
Components: Strict bag size control (±0.3mm tolerance)
Interface: Optimal snap ring/hole fit (0.5-1mm interference)

With full-process quality control and scientific cleaning design, dust collection systems can achieve reliable, long-term operation with “zero failures, zero exceedances.” Companies should pay close attention to these technical details and work closely with professional manufacturers for optimal performance and environmental compliance.

Final Tip: Bag detachment isn’t a product quality issue – it’s an installation or tube sheet precision problem! Choosing the right supplier and following proper procedures ensures stable operation.