HTS Eclipse – Minnox Ultra-Low Emissions Line Burner

Overview

The Honeywell Minnox is a premix, ultra-low emissions (ULE) line-style burner engineered for direct-fired process air heating in duct and air handling applications. Its patented design uses a premixed gas/air mixture with excess air, producing a cooler flame (approximately 2,200°F / 1,200°C) that achieves emissions levels below 5 ppm NOx and below 30 ppm CO at 3% O&sub2; — meeting or exceeding all state, regional, national, and international emission standards. All Minnox systems are custom-engineered to meet specific production and installation requirements and are typically supplied with the burner, mixer, and supply manifold pre-assembled into a duct section or as a side plate for insertion into existing process ductwork.

The Minnox features a recirculating flame geometry that significantly reduces CO emissions while enabling safe, efficient direct-fired heating. This eliminates the inefficiency of indirect heating methods and removes the risk of product discoloration or taste contamination associated with traditional direct-fired systems — making it well-suited for food processing, malt drying, auto finishing, and other sensitive process heating applications.

Features & Benefits

• Patented premix burner design — utilizes a premixed gas/air mixture with excess air for a cooler, cleaner flame and exceptional NOx reduction
• Ultra-low emissions — NOx < 5 ppm and CO < 30 ppm at 3% O&sub2;, meeting or exceeding all international emission standards
• Recirculating flame geometry — acts to significantly reduce CO emissions without combustion performance penalty
• 10:1 turndown ratio — wide modulation range for flexible process control across varying load conditions
• Direct-fired efficiency — enables efficient direct air heating without the losses associated with indirect heating systems
• Safe for sensitive products — eliminates discoloration and taste contamination risks associated with traditional direct-fired systems
• Improves workplace air quality — reduces combustion byproducts inside the facility for a safer, healthier work environment
• Custom-engineered systems — every Minnox installation is designed to meet specific production, duct geometry, and installation requirements
• Packaged convenience — burner, mixer, and supply manifold supplied pre-mounted in a duct section or as a side plate for existing ductwork
• Multiple mounting orientations — supports vertical (up/down), horizontal (left/right), and slot firing configurations

Technical Specifications

• Burner Design: Ultra-Low Emissions (ULE) premix nozzle-mix burner with integrated mixer
• Emissions: NOx < 5 ppm; CO < 30 ppm; HCHO < 0.17 ppm (at 3% O&sub2;, estimated; process-dependent)
• Turndown Ratio: 10:1
• Heat Input Range (per section):
  • Straight section: 135 kW (460,000 Btu/h)
  • T-section: 540 kW (1,844,000 Btu/h)
  • Cross section: 675 kW (2,305,000 Btu/h)
• Burner Start Input: 20% of nominal input
• Fuel Types: Natural Gas (H); Propane (<10% unsaturated); Butane (<10% unsaturated)
• Proportionator Gas Pressure: 100–300 mbar (40–120 in w.c.)
• Pilot Type: Integral, nozzle-mixing, spark-ignited; interrupted pilot
• Pilot Input: ≈15 kW (≈51,000 Btu/h)
• Pilot Gas Pressure: 16–28 mbar (6.5–11 in w.c.)
• Combustion Air Pressure: 48 mbar at mixer inlet (19.3 in w.c.), neutral chamber pressure
• Combustion Air Volume: 205 Nm³/h per 135 kW (120 scfm per 460,000 Btu/h)
• Combustion Air Temperature: ≤ 40°C (104°F)
• Process Air Velocity: Min ≈2 m/s (≈390 ft/min); Recommended ≈12 m/s (≈2,400 ft/min); Max ≈20 m/s (≈3,900 ft/min)
• Process Air Differential Pressure: ≈0.5 mbar at 10 m/s (≈0.2 in w.c.); ≈2.0 mbar at 20 m/s (≈0.8 in w.c., estimated)
• Process Inlet Temperature: ≤ 300°C (570°F)
• Process Outlet Temperature: ≤ 500°C (930°F)
• Process Pressure Limits: Negative ≤ 6 mbar (2.4 in w.c.); Positive ≤ 10 mbar (4 in w.c.)
• Visible Flame Length: 300 mm (12 in) from whirl plate; protected by 400 mm (16 in) combustion chamber
• Flame Detection: UV Scanner
• Ignition: Spark-ignited integral pilot, nozzle-mix type
• Mounting Options: Vertical (up/down), Horizontal (left/right), or Slot Firing

Applications

• Direct-fired process air heating in ducts and air handling systems
• Food processing — where clean combustion and product safety are critical requirements
• Malt drying and grain processing
• Automotive paint finishing and coating ovens
• Lumber drying and wood products processing
• Paper and pulp drying processes
• Dairy product processing (see technical worksheet)
• Any process requiring ultra-low NOx direct-fired air heating with strict emissions compliance

Minnox Accessories

• Mixer & Supply Manifold – Integral mixer assembly supplied pre-mounted with burner for complete packaged installation
• Duct Section / Side Plate – Burner assembly supplied in a duct section or as a side plate for insertion into existing process ductwork
• UV Scanner – Flame detection device for burner supervision; required for system operation

Documentation