About the Client
DuPont de Nemours Inc., a global leader in specialty chemicals and advanced materials, operates multiple manufacturing facilities in the USA that process polymer-based products using pigments and other fine powders. These operations demand precise material handling, high-performance dispersion, and strict control over product quality and consistency. In the pigment industry, DuPont is known for its technical innovation and process expertise, enabling the development of advanced coatings, colorants, and polymer composites used in automotive, industrial, and consumer applications.
Challenge
A major challenge faced at DuPont USA site was managing the significant levels of fine pigment dust generated during feeding, extrusion, and material handling, without excessive product loss or operational risk. Key concerns included environmental, operator, and equipment safety, as well as minimizing economic loss by preventing valuable pigment particles from being over-extracted and lost to the filtration system.
Product Yield: Product (pigment) losses through uncontrolled or excessive extraction (overextraction*) led to direct financial loss (~$300,000/year).
Explosion Safety: Product (pigment) losses through uncontrolled or excessive extraction led to direct financial loss (~$300,000/year).
Unbalanced System: Unbalanced extraction led to unstable processes, loss of yield, increased downtime, and maintenance.
Inside Emissions: Excessive dust emissions compromised air quality and increased fouling and cleaning efforts.
What is Overextraction?
Overextraction refers to the unintended removal of valuable pigment particles or fine powders from a production environment due to excessive airflow or suction within the extraction system. In pigment manufacturing and processing, this occurs when high-velocity air streams from hoods, ducts, or filtration units draw product away from the intended process flow, leading to measurable product loss, reduced yield, and increased operational costs. Overextraction is often caused by poorly balanced ventilation design or overly aggressive dust control settings, and it can negatively impact both efficiency and product quality.
Approach
When a standard dust collection system is chosen, manufacturers gamble with securing performance. As the existing extraction system at DuPont was underperforming, they faced unstable processes, unpredicted downtime, higher maintenance costs and loss of yield. That’s why they contacted JOA, which came with their proven approach:
Pre-engineering study:
To start, JOA conducted a Pre-Engineering Study, in close collaboration with the DuPont USA team, to assess dust emission challenges on-site. The goal was to identify root causes, evaluate technology options, and define the project scope.
- Modeling each potential extraction point across two production lines using JOA’s in-house Air Technical Model, specifically tuned for fine pigment behavior.
- Simulating airflow requirements to ensure effective dust capture without triggering overextraction.
- Extensive validation and iteration during pre-engineering (or FEED) and commissioning ensured that minimal valuable pigment resources was lost to the dedusting system, feeding directly into calculable annual resource savings.
Design & Engineering:
The system was engineered from pre-engineering data to balance dust control, process continuity, and product retention, with precise airflow and safety design ensuring performance without sacrificing yield.
- The Pre-engineering study identified high-risk overextraction points. These were addressed through a combination of:
- Hood geometry
- Restrictor tuning
- Intelligent automation control
- Combined extraction points, such as those near vibratory trays and hoppers, to prevent concentrated airflow from pulling pigment out of the process.
- Custom-designed Deflector Extraction Hoods at critical process steps like feeding and weighing. These hoods provided high-efficiency dust containment with minimal entrainment of pigment material.
- ATEX safety through optional explosion protection features:
- Conductive, grounded ductwork using galvanized or uncoated steel
- Anti-static filter cartridges
- ATEX-certified rotary valves, burst disks, and flameless venting
- Grounding and anti-static measures
System Realization:
In the realization phase, JOA installed and balanced a tailored extraction system, fine-tuned to support DuPont’s process needs under varying operational conditions.
- A balanced system of 21 extraction points, with 20 restrictors installed to tune airflow precisely at each location, achieving a pressure balance within 1 Pascal.
- Automated valves and VFD (Variable Frequency Drive) controls on the main extraction fans allowed real-time adjustment of airflow based on line operation (e.g., switching between single-line and dual-line modes).
- This ensured energy-efficient operation while avoiding excessive suction that could lead to pigment overextraction.
- Integrated air bleeds and deflector bleeds to fine-tune local airflow and reduce overextraction risk.
*Verified: conveying velocities remained within the safe V₀Crit™ range, allowing airborne dust to be extracted while preventing unintentional pigment removal.
Outcome
Safety, Efficiency, and Major Product Savings.
- The new central dedusting system enabled DuPont to meet their stringent workplace dust exposure limits (<5 mg/m³, 8 h TWA) with dramatically reduced manual cleaning.
- Eliminated overextraction of fine pigment powder, previously costing up to $300,000/year. The design’s air technical balance, deflector hoods, and controllable extraction rate meant dust and pigment emissions were captured only where necessary, not where it carried off valuable product.
- Operator productivity and equipment uptime increased due to improved working environment and less frequent stoppages and fouling.
- The system is futureproofed for explosion safety compliance, process changes, and operational flexibility, with easy adjustment of extraction rates and fan speed as required.
- System balancing and VFD-fan automation reduced energy use and noise to the minimum required for process safety and dust handling.
- Housekeeping and routine dust residue cleaning requirements dropped substantially, further improving OPEX and safety.
Key Technical Highlights
- 21 extraction points, 20 restrictors for 1 Pa balance.
- Precise Air Technical Modelling for all dust sources (especially pigment).
- Deflector hoods and bleeds, custom-designed for each application.
- Dual-header system allows each line to operate with tailored extraction rates and independent shutdowns.
- Automated valves and VFD fan enable dynamic, optimized control.
- Explosion Safety optimized materials and equipment selection.
- Built-in flexibility for further process capacity or safety upgrades.
- Supported by validated Air Technical Modeling models
Conclusion
Through an integrated approach and combining airflow modelling to validate the design JOA was able to provide an optimized solution including: Hood and restrictor design, Fan automation and rigorous explosion safety engineering. Herewith, DuPont’s pigment dust extraction challenges were solved at their USA facility.
The well thought-through solution balanced air velocities precisely, protected operators, controlled combustible dust risks, and enabled annual cost savings of up to $300,000 by preventing loss of over-extracted valuable pigment. System flexibility ensures DuPont can quickly adapt to production changes or future regulatory requirements, and the project stands as a benchmark for high performance, safety-first industrial dedusting in the chemical industry and especially in the pigment and polymer sector.
