Surface combustion is a gas burning technique in which premixed gas and air burns on a surface layer of a permeable and/or perforated medium. Depending on the intensity, the combustion can occur in two modes; radiant and blue flame.

Combustion inside a permeable medium produces generate heats to incandescent which a portion of the energy input can be released as thermal radiation. The flame colour is red/orange, and it produces extremely low emissions of NOx, CO and non-burnt fuel components. This mode occurs at low intensities of 200-500 kW/m2.

The major part of the convective energy released when using blue flame mode on high porous metal fiber produces a distant, spear-shaped flame. PP Systems' special design, with an infrared ring surrounding the base achieves wider turn-down ratio and allow for better resistance in high wind operation. 

Blue flame mode combustion can still produce very low NOx and CO emissions when using MFB. In this mode, higher excess air ratios are suggested. This mode occurs at intensities higher than 1,000  kW/m2 and can
support intensities over 5,000 kW/m2.

​

The high velocity blue flame hovers perforate surface allows rapidly heat conduction when the flame directly contact the object, heat highly recommend for external tank heating.

This perforation leads to a more homogeneous combustion for both radiant and high-intensity blue flame modes and allows for a smooth-transition between both modes with an extended turn-down ratio.