Case Study:

Pleated bags installed in cement grinding mill

Location: 

  • CHINA

Operation:

Cement grinding mill

Dust type:

Cement dust

Problem:

  • The overall cement group is focusing on lowering emission
  • Emission was about 28mg/m3, which is above the emission standard
  • The filter bags are always broken with holes, caused by the harsh airflow
  • The bags service life is short with only about 6 months
  • The pressure drop is high, approx. 2900pa

Solution:

Replacing 3584 bags with 1820 pleated bags

 

TECHNICAL FACTS

    
  BEFORE AFTER
  Bag filter Pleated bag solution
Airflow in unit  310.000 m³/hour
Dusttype  Cement, grinding mill
Collector running hours/year  3.500
Filter model Filter bag CPBS
Media/cloth type  Polyester  Polyester w. PTFE membrane
Length  3.500 2.200
Number of bags/cartridges  3.584 1.820
M² in each bag/cartridge  1,42 5
M² in unit  5.090 9.100

Advantages:

By replacing the existing filter bags with Pleated Bags from Nordic Air Filtration the following results were obtained:

  • The Spunbound media is less susceptible to harsh airstream than the filterbag = less abrasions
  • Less wear of the filter media due to larger dropout box (3,9m shorter filter) = "Gravity-filtration" separates the larger dust particles
  • Surface filtration increases lifetime due to a lower dp, pleated bags after 6 months, 1200pa
  • Lower emission than with conventional filter bags.
  • The PTFE-coating of the media provides optimal dust release capacity during pulse cleaning = prolonged life cycle of the cartridges
  • Further more increasing of the media surface will also add to the longer lifetime due to decrease of air-to-cloth ratio

Solution after: 

Advantages – confirmed by customer:

  • Less dust discharging and lower emssion, 3.4 mg/m3
  • dp is about 1200pa (after) vs 2900pa (before)
  • 20% reduction in operation time for the same production capacity

Sales Representative:

BB