Views: 0 Author: Site Editor Publish Time: 2025-12-11 10:35:24
In the field of industrial dust removal, standardized filter bags can meet the needs of conventional working conditions. However, for special scenarios such as high temperature, strong corrosion, and high-viscosity dust, non-standard custom filter bags are the "core key" to adapting to dust removal systems.
Yet many enterprises only focus on material and size during customization, ignoring critical issues such as working condition matching and process details. This leads to premature filter bag damage, a sharp drop in dust removal efficiency, and even impacts the operation of the entire production line. Today, combining actual working conditions, we will discuss the details that must be closely monitored for non-standard custom filter bags to help everyone avoid detours.
The core of non-standard customization is "adapting to working conditions". If the working condition parameters are not clearly confirmed, subsequent customization will be nothing but castles in the air.
First, temperature parameters must be clarified. It is not only necessary to know the long-term operating temperature, but also to figure out the instantaneous maximum temperature and temperature fluctuation range. For example, the instantaneous temperature of flue gas in the foundry industry may surge to 180°C. If polyester material is selected only based on the long-term temperature of 130°C, the filter bag will be easily melted by high temperature; for the high-temperature working conditions at the cement kiln tail, high-temperature resistant materials such as PPS and Fluomix should be prioritized.
Second is the physical and chemical properties of dust, which directly determine the "durability" of the filter bag. If the dust pH value is < 5 (strongly acidic) or > 9 (strongly alkaline), ordinary polyester filter bags will be quickly corroded and embrittled, and PTFE material must be used; high-hardness ore dust will continuously wear the filter bag, so a wear-resistant layer thickening treatment is required; for flammable and explosive dust such as flour and aluminum powder, anti-static polyester filter bags with conductive fibers added should be selected to avoid electrostatic accumulation and explosion.
In addition, flue gas humidity and filtration wind speed cannot be ignored. When high-humidity flue gas is close to the dew point, it is prone to condensation and bagging, so the filter bag should be treated with water and oil repellency; excessive filtration wind speed will intensify filter bag wear and blockage, while excessively low wind speed will cause equipment waste, which must be accurately calculated based on the processing air volume and filtration area.
Dimensional errors of non-standard filter bags are a high-frequency cause of air leakage and falling off after installation, especially the matching degree with the dust collector's tube sheet and bag cage, which must be seamless.
Before customization, the aperture, thickness of the tube sheet and the effective installation height of the filter bag, as well as the size parameters of the bag cage (diameter, length, number of longitudinal bars) must be accurately measured. The diameter tolerance of the filter bag is recommended to be controlled within ±1mm, and the length tolerance ≤ ±2mm. Otherwise, it may either not fit into the tube sheet or have excessive gaps with the tube sheet, resulting in air leakage. For special-shaped dust collectors such as flat-bag type and elliptical type, detailed installation space drawings must be provided to prevent the filter bag from failing to stretch normally due to insufficient space.
The sealing structure must also be selected according to the working conditions. For negative pressure working conditions, the sealing of the bag mouth elastic expansion ring should be strengthened to prevent air leakage; for flange-sealed ones, the flange size and gasket material should be confirmed to ensure a perfect fit with the equipment interface.
There is also the end structure. The design of the filter bag end should be determined according to the dust cleaning method (pulse jet, reverse air, mechanical vibration). For example, the bottom of the filter bag under pulse jet working conditions should be reinforced to prevent damage from the impact of jet airflow.
The material and process of the filter bag are the core factors determining its service life, and the adaptation schemes for different working conditions vary greatly.
First, let’s talk about the selection of base materials:
Then look at the surface treatment process. For viscous dust (such as cohesive dust in the chemical industry), PTFE membrane coating must be applied to greatly improve dust cleaning effect and reduce the probability of bagging; water and oil repellency treatment is required for high-humidity working conditions; wear-resistant layer thickening on the dust-facing surface of the filter bag is a key operation to extend service life for high-wear working conditions.
Here, we need to focus on the sewing process. Many people overlook the material of the sewing thread—the thread must be consistent with the temperature and corrosion resistance of the filter bag itself, otherwise the thread will fail before the filter bag; the stitch density is recommended to be ≥12 stitches per inch. Key parts such as the bag mouth and bottom should be double-threaded or patched to prevent thread breakage during operation.
For customized filter bags, the installation and acceptance links must be strictly checked. During installation, the matching gap between the filter bag and the bag cage should be confirmed—too large a gap will cause the filter bag to shake and wear, while too small a gap will affect the expansion and contraction of the filter bag; for special-shaped filter bags, it is best to simulate the installation process in advance to avoid on-site rework.
During acceptance, in addition to checking the size and appearance, the manufacturer can be required to provide a material inspection report to confirm that the material is not "shoddy". If conditions permit, a static air tightness test can be conducted to identify potential air leakage points.
In addition, operation and maintenance planning should be done in advance. Spare parts should be prepared according to the wear rate of the working conditions, and the spare parts must be completely consistent with the specifications of the customized filter bags; at the same time, the warranty period (usually 6-18 months, depending on the working conditions) and after-sales technical support should be agreed with the manufacturer, such as working condition analysis and adaptation adjustment after filter bag damage.
Non-standard custom filter bags are not simply "making bags according to size", but a full-process adaptation from working condition research to installation and operation and maintenance. By closely monitoring the above details, the filter bag can truly become a "reliable line of defense" for the dust removal system, ensuring both dust removal efficiency and reducing later replacement costs.
If you have any experiences of pitfalls in non-standard filter bag customization, welcome to share and exchange in the comment area!
