Lean gas burner

A gas burner for burning a gas having a low calorific value, the gas burner comprising:

• a cylindrical body having:
• a first annular zone formed between an external wall thereof and an internal wall thereof, and which extends substantially parallel to the external wall,
• a second annular zone formed downstream of the first zone between the external wall and the internal wall;
• a first opening to supply the gas, and which extends substantially parallel to a longitudinal axis of the body;
• a second opening to supply primary air, and which is formed in the external wall in fluidic communication with the first annular zone;
• a third opening to supply secondary air, and which is formed in the external wall in fluidic communication with the second annular zone;
• an annular slot to introduce the primary air from the first annular zone into a combustion zone, the annular slot being formed between the external wall and an upstream end of the internal wall, and formed such that the primary air is supplied to the combustion zone in the form of a conical sheet of air, and creates a compression zone;
• and
• orifices formed in the internal wall to introduce the secondary air from the second annular zone into the combustion zone, and are disposed so as to allow swirling of the secondary air.

A system, comprising:

• a biomass gasifier;
• and
• a gas burner for burning a gas having a low calorific value, the gas burner including a cylindrical body having:
• a first annular zone formed between an external wall thereof and an internal wall thereof, and which extends substantially parallel to the external wall,
• a second annular zone formed downstream of the first zone between the external wall and the internal wall;
• a first opening to supply the gas, and which extends substantially parallel to a longitudinal axis of the body;
• a second opening to supply primary air, and which is formed in the external wall in fluidic communication with the first annular zone;
• a third opening to supply secondary air, and which is formed in the external wall in fluidic communication with the second annular zone;
• an annular slot to introduce the primary air from the first annular zone into a combustion zone, the annular slot being formed between the external wall and an upstream end of the internal wall, and formed such that the primary air is supplied to the combustion zone in the form of a conical sheet of air, and creates a compression zone;
• and
• orifices formed in the internal wall to introduce the secondary air from the second annular zone into the combustion zone, and are disposed so as to allow swirling of the secondary air.