If you’re a dryer maintenance manager, you’re goal is to keep the dryer online and doing its job. Among other things, this means keeping the burner going. But, having a source of combustion means there will be emissions. The majority of dryers now have some sort of secondary cleanup, such as a thermal oxidizer to take care of those emissions.  However, there are ways to reduce the load on secondary cleanup, or reduce emissions in the absence of such.

Annual tuning of your burner system is essential to its proper operation as well as to the safety of your team and equipment. By checking the main burner for proper combustion from high to low fire, excess fuel usage is minimized. This decreases the risk of fires and explosions by reducing the generation of volatile organic compounds (VOCs). Routine maintenance will increase the likelihood that the burner will start and shut down appropriately. Inspection of the burner system gives you peace of mind that your system complies with current safety standards or indicates where upgrades and modifications are necessary.


Problems commonly seen in industry


  • CO + NOx + VOC creation
  • Purge timer length
  • Won’t stay lit
  • Flame too hot
  • Flame not hot enough
  • Excessive fuel use

Combustion Chamber

  • CO + NOx + VOC creation
  • Buildup in ductwork
  • Black goo dripping from ductwork, outlet hopper (drop box), fans, etc.
  • Frequent fires or explosions


  • High oxygen content in drum and ductwork
  • High gas velocity
  • Inefficient separation by outlet hopper (drop box) and cyclones
  • Decreased capacity in Thermal oxidizer or other secondary cleanup device

Thermal Oxidizer

  • Decreased throughput/capacity
  • Excessive plugging
  • Excessive burning out (more than 1x per week)
  • Frequent burning out (more than 2x per month)

Cyclones & Airlocks

  • Excess particulate in the EGR and/or Secondary cleanup
  • Flame not hot enough — particulate getting into combustion air/recycle gases
  • TO decreased throughput/capacity
  • Excessive plugging in TO & ducts
  • TO: Excessive burning out (more than 1x per week)
  • TO: Frequent burning out (more than 1x per month)


  • Poor gas flow rate
  • Increased amperage for same flow
  • Buildup on blades

Instrumentation & controls

  • Bad/Inconsistent readings
  • No readings
  • Wrong settings


  • Secondary clean-up (thermal oxidizer, scrubbers, baghouse, cyclones) issues — plugging, fires, inefficiency, overloading
  • Out of compliance
  • Excess particulate
  • Thermal damage to product (less product throughput than expected, black specs)

Thompson’s Remedies

Burners: Keeping the flame alive

  • Tuning
  • Combustion air conditioning/directing
  • Recycle gas conditioning/directing

Combustion Chamber: ensuring proper combustion/recycle gas mixing for uniform drying gases

  • Replace or repair burner skirts
  • Redesigned recycle gas inlet
  • Redesigned combustion chambers
  • Refractory elimination
  • Combustion chamber replacement
  • Mechanical inspection of combustion air source and EGR introduction

Seals: Keeping what’s supposed to be in, in. Keeping what’s supposed to be out, out.

  • Replacement seals
  • Seal designs
  • Heat shield installation
  • Seal ring resurfacing

Thermal Oxidizer: Keep the EPA, I mean environment happy

  • Emissions testing before and after TO

Cyclones: Recovering as much product as possible

  • Cyclone inspections
  • Cyclone modifications
  • Replacement cyclones

Airlocks: Aiding cyclones one rotation at a time

  • Airlock inspections
  • Replacement/refurbishment airlocks

Fans: A usual suspect for reduced capacity or

  • Fan inspections
  • Flow testing
  • RPM testing

Instrumentation & Controls

  • Replacement instrumentation
  • Additional instrumentation
  • PLC programing
  • Control narrative development
  • Automatic shutdowns for upset conditions


  • Replacement and new VFDs
  • Adding VFDs to control loops


  • Emissions testing
  • Reduce VOC creation
  • Reduce CO and NOx creation
  • Mechanical inspections of cyclones, baghouses, airlocks
  • Seal inspection

Help you stay in compliance

  • Keep your neighbors happy
  • Keep the earth happy

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