Customer profile
While preserving production capacity was in itself a challenge, our client was also tasked with reducing emission levels at a cement grinding mill.
The emission levels were 28 mg/m³, and the life cycle of the filter bags was only 6 months. After installing pleated bag filter cartridges, the emission levels were reduced by 88% and the operation time for the same production capacity was reduced by 20%.
Location: China
Key results
88% decrease in emissions
58% decrease in pressure drop
Improved durability and maintenance
High emissions and short filter lifetime
The cement industry is under increasing pressure to reduce emissions and comply with stringent environmental standards. This case study focuses on a specific cement group striving to lower its emissions, which currently exceed regulatory limits.
Challenges
Excessive Emissions: The emission level is approximately 28 mg/m³, surpassing the established emission standards.
Filter Bag Failures: The filter bags used in the emission control systems frequently develop holes due to harsh airflow conditions.
Short-Service Life of Filter Bags: The filter bags have a significantly short lifespan, lasting only about six months.
High-Pressure Drop: The system experiences a high-pressure drop of approximately 2900 Pa, which impacts its overall operational efficiency.
Replacement of filters with high performance pleated bags
The filtration system was upgraded, replacing 3584 filter bags with 1820 pleated bags, each equipped with 5m² media 100% synthetic with ePTFE membrane.
Emission reduction and longer filter lifetime
Together with the customer, we have implemented the new pleated bags and compared the system's performance over time.
General System Information
| Parameter | Data |
| Air flow in unit | 310.000 m³/hour |
| Dust Type | Cement Dust |
| Collector running hours | 3.500 hours/year |
Technical Data
| Before | After | |
| Filter model | Conventional Filter Bags | Top Loader CPB pleated bag |
| Filter media | Synthetic | 100% synthetic media with ePTFE membrane |
| Length [mm] | 3.500 | 2.200 |
| Number of filter bags / cartridges | 3584 | 1820 |
| Filration surface in each filter bag / cartridge [m²] | 1,42 | 5 |
| Filtration surface in entire system [m²] | 5090 | 9100 |
| Emission mg/Nm³ | 28 | 3,4 |
| Differential pressure Pa | 2900 | 1200 |
| Production capacity | 20% reduction in operating time with the same production capacity |
Hengst Filters deliver a gain in productivity, emission reduction and longer filter lifetime
With the upgrade to pleated bags featuring 100% synthetic media with an ePTFE membrane, the filtration surface area increased by 79%, while reducing the number of pleated bags by half compared to traditional bags, from 3,584 filter bags to 1,820 pleated bags. This means that the client was able to purchase 1764 fewer units than with the conventional system.
This results in productivity gains and significant reductions in emissions:
88% decrease in emissions
By switching to pleated bags, the emissions were drastically reduced from 28 mg/m³ to 3.4 mg/m³. This lower emission rate results in less dust discharging, contributing to a cleaner environment and ensuring compliance with stringent emission standards.
58% decreased pressure drop
After six months, the pleated bags maintained a pressure drop of 1200 Pa, whereas conventional filter bags measured 2900 Pa and would typically require replacement.
Improved Durability and Maintenance
The Spunbound media used in pleated bags is less susceptible to abrasion from harsh airstreams, reducing wear and tear. The larger dropout box and "gravity-filtration" mechanism effectively separate larger dust particles, minimizing wear on the filter media. This design leads to less frequent maintenance and replacement needs, ensuring more consistent operation and reducing downtime.
The prolonged filter lifetime enabled the client to reduce operation time by 20% for the same production capacity, resulting in a considerable daily energy savings.
Get in touch
Contact our team for any questions and support regarding Filter Cartridges, Pleated Bags & Flat Cells
sales.nakskov[at]hengst.com