Staged Combustion Low NOx Burners
Selas ULNx Staged Combustion Burners Meet Low NOx Requirements For Petrochemical Applications.
Strict low NOx emission requirements for petrochemical furnaces have created a demand for low NOx burners. Selas K900 ULNx Inspirator Burners meet this demand while providing other advantages such as lower initial cost, lower installation cost and easy maintenance. These burners are designed for new installations or for retrofitting existing furnaces. They can be used in brick or fiber-walled furnaces and do not require a burner tile.
FEATURES & BENEFITS
- Low NOx emmission satisfies the most stringent regulations
- Flat-flame design provides more uniform heating and extends tube life
- Constructed for fiber or brick walls, with or without burner blocks
- Easy installation in new furnaces, conversions or retrofits
OPERATING PRINCIPLES
Selas ULNx Staged Combustion Burners Feature Low NOx Emission
Remarkably low emission, less than 25 ppmv (50 mg/Nm3). Varies with excess air, furnace temperature and other variables.
Superior Heating Uniformity
The flat-flame tip produces a wall-hugging flame of minimum thickness and confines the flames to the immediate vicinity of the hot-face, protecting the alloy tubes in front from flame impingement. This lowers maintenance costs since uniform tube temperature increases process life and decreases coking.
Selas ULNx Staged Combustion Burners Need No Burner Block
The burner is installed by cutting a hole through the furnace wall from outside. The burner assembly is then inserted into the hole and bolted to the casing. The burner is designed to be self-supporting and does not require a burner block. If, however, a burner block is desired, Selas supplies a fired, flat block which, in a fiber wall, requires a support bracket.
Easy To Retrofit
The ULNx burner can replace existing burners either one-for-one, one-for-two, or more, depending on the capacity of the installed burners. Certain installations use burner cups while others use a burner tile. For best results the burner tile, or block, should have at least a 5-inch throat and a flat hot-face. At lower temperatures, however, a cup block also offers satisfactory results.
Easy To Maintain
Fuel to an individual burner can be shut off without shutting down the rest of the furnace. The burner can then be loosened and removed from outside the furnace. A spare burner can be inserted and put into use while the removed burner is serviced.
Selas ULNx Staged Combustion Burners Are Made For Easy Lighting
The burner operates stably with a better than 3:1 turndown even during a cold startup.
Optional Silencer Is Available
The silencer controls burner noise and meets domestic OSHA standards.
Series K900 Staged Combustion Inspirator Wall Burner Technical Features
Capacity - The nominal firing rate of the K985-501 L ULNx Burner is 1,350,000 BTU/h, LHV (396 KIN) with primary and secondary air and a furnace draft of at least 0.2" W.C. (50 PA). Typical operating fuel pressure is 20 psig (1.4 bar gauge) and turndown is 3:1. The burner can be customized to fit special application requirements.
Construction - The ULNx burner features an inspirating venturi which also includes a specialized fuel nozzle and tip. The completed assembly is bolted to the casing wall. Control is achieved with only 2 valves; an air shutter supplied by Selas and a fuel-valve supplied by the end-user to fit a 3/4" NPT gas inlet. Wall thickness is an option which is incorporated into the venturi design; however, it is not adjustable in the field. The optional silencer can be attached to the venturi and a mounting plate.