An apparatus (having at least one burner having a plurality of co-axial channels and a control system for regulating a length of a flame for partial oxidation of hydrocarbon feed in a reactor is provided. The at least one burner has a first channel to inject a stream of oxidizer, a second channel to inject a stream of the hydrocarbon feed and a third channel to inject a stream of swirl gas at a first velocity into the hydrocarbon feed stream. The control system regulates the length of the flame to have a constant flame shape and position by regulating the first velocity of the swirl gas that generates the swirl motion within the hydrocarbon feed stream.

A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

A combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.