Case Study:

Bag abrasion issues in Cement Finish Mill solved with pleated bag with ePTFE membrane

Location: 

  • USA: Pennsylvania - Harrisburg

Operation:

Cement Finish Mill

Dust type:

Finish Mill Ventilation Cement Dust

Problem:

The Customer often needed to shut down its 6,000 ACFM / 10.200m3/h dust collector for the finish mill due to abrasion issues occurring approx. 18”/450mm from the bottom of the bags. The abrasion issues involved a risk of violating permits and the frequent shut downs decreased production capacity. After evaluating the system, 2 major problems was found that needed to be solved:

  • The cleaning system was inefficient. 
  • The filter design was inadequate causing frequent shutdowns.

Solution:

Using Pleated bags with a high efficiency ePTFE membrane was recommended:

  • The shorter pleated bag design (from 120”/3.050mm down to 40”/1000mm) increased the drop out box by 80”/2.000mm and removed the filter from the abrasion zone
  • The ePTFE membrane media provided optimal dust release capacity to counterweigh the undersized cleaning system
  • A new cleaning package which optimized pulse valves and controller was installed

TECHNICAL FACTS

    
  BEFORE AFTER
  Bag solution Pleated bag solution
Dusttype  Finish mill ventilation cement dust
Bag/Pleated bag model Filter bag Pleated bag
Media/cloth type  Polyester felt Spun bond with ePTFE membrane
Length  120”/3050mm 40”/1000mm
Number of elements 143 143
Sqft in each element (Total) 15sf/1,4m2 (2,145sf/200m2) 23sf/2,1m2 (3,289sf/305m2)
Filter life 6-9 months 2+ years

Advantages:

  • Longer filter life due to elimination of abrasion
  • Lower emissions
  • Reduced down time and maintainance cost
  • Lower operating dp
  • Cost savings