Customer Profile
One of the largest steel manufacturers in China was facing growing pressure from environmental authorities to address its high levels of particulate emissions.
Operating a large-scale facility equipped with 1408 traditional filter bags, the company struggled to maintain emissions within the acceptable regulatory limit since it consistently exceeded 20 mg/m³, posing both compliance risks and operational inefficiencies.
Location: China
Dust type: Material for smelt iron
Key Results
97% decrease in emissions
57% increased filtration surface
Optimized dust release and suction
3,9m shorter filter resulted in a larger Dropbox and less abrasion
High emissions and short filter service life
The plant used 1408 conventional polyester filter bags with an ePTFE membrane, each 6 m long. The aim was to reduce emissions to below 8 mg/m³, which corresponded to a reduction of at least 60%.
In addition to the regulatory requirements, the existing filter system had reached its technical limits. There was an urgent need for a highly efficient, durable and energy-saving solution. Therefore, the company decided to partner with Hengst Filtration and replaced the 6 m long conventional filter bags with 2 m long pleated bag filters.
The challenges
- High dust and emission levels
- Poor filter quality leading to rapid deterioration and shorter service life
- High differential pressure
- High energy consumption
Replacement of filters with high performance pleated bags
The filtration system was upgraded with:
Type of Product: CPB - Top Loader Pleated Bag
Number of filters: 1408 pleated bag
Filter media: Spun bond pleatable polyester
Filter media area: 3,8m²
Significantly lower emissions, lower pressure drop and better cleaning of the filter
Five months after the installation of the new pleated bag filters and after the systems had been in operation for 24 hours, an inspection of the filtration system was carried out. Our customer achieved impressive results that exceeded their expectations:
General system information
| System parameters | System data |
| Air flow in the system | 210,000 m³/h |
| Dust type | Material for iron smelting |
| Operating hours of the system | 8000 hours/year (full year) |
Technical Specifications
| Before | After | |
| Filter model | Conventional bag filter | Top Loader CPB Pleated bag filter |
| Filter media | Polyester with ePTFE membrane | Spunbonded pleated polyester |
| Length [mm] | 6000 | 2070 |
| Number of bag filters/filter cartridges | 1408 | 1408 |
| Filtration area in each pleated bag filter / filter cartridges [m²] | 2,45 | 3,84 |
| Filtration area in the entire system [m²] | 3450 | 5406 |
| Emissions mg/Nm³ | > 20 | 0.6 (after 5 months of operation) |
From high emissions to high efficiency
97 % reduction in emissions
The target of reducing emissions from over 20 mg/m³ to less than 8 mg/m³ was far exceeded with the actual result of 0.6 mg/m³.
Lower pressure drop and lower energy consumption
By using pleated bag filters, the customer was able to reduce the continuous pressure drop across the entire collector system, as the filter area is significantly larger compared to conventional bag filters. The filter area was increased from 3,450 m² to 5,406 m².
Better cleanability of the filters
By using shorter pleated bags, the customer achieved a significantly larger separation area, allowing gravity to take over most of the coarse particle separation. This reduced the pressure on the filter cartridges, making them more resistant to wear on the filter media.
Get in touch
Contact our team for any questions and support regarding Filter Cartridges, Pleated Bags & Flat Cells
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