What is the difference between single stage, two stage, and proportional adjustment burners?

What is the difference between single stage, two stage, and proportional adjustment burners?
According to the operation mode, burners are divided into three types: single stage burner, two (dual) stage burner, and proportional adjustment burner. The differences between them are as follows:
1. Single stage burner:
A single stage burner is as large as a fire. The size of firepower and flame will not change, only in two states: start and stop. Single stage burner is used in heating industries where temperature or pressure control requirements are not high and temperature or pressure errors are allowed to be significant.
Most burners with a power of less than 600KW (500000 kcal) use single stage burners.
2. Two (dual) stage burner:
The working mode of the two-stage burner is low fire and high fire. First light the small fire and wait for the small fire to stabilize before igniting the large fire. That is to say, the burner has two working points, which can work under first level fire (low fire) or second level fire (high fire). There are three states: high fire, low fire, and stop. Insulate with low heat; Use a large fire to keep warm. Double stage fire is used in heating industries with high requirements for temperature or pressure control, with a permissible temperature error of 10 ° -20 °.
Burners with a power greater than 600KW (500000 kcal) are mostly two-stage burners.
3. Proportional adjustment burner:
The proportional adjustment burner also starts from a low fire and then operates according to the required ratio. The working points of this burner are not limited, and the firepower and flame size can be switched at any point within the power range, equivalent to an infinite number of gears. The proportional adjustment burner controls temperature and pressure extremely accurately and is almost in a stable state. For example, if the temperature is set to 100 °, the proportional adjustment burner will always be at 100 ° plus or minus 1 ° (99 ° or 101 °). Range, adjust the firepower of the burner.
Proportional adjustment burners are divided into two types: mechanical proportional adjustment and electronic proportional adjustment. The mechanical proportional adjustment burner adopts a servo motor to drive the mechanical linkage control of fuel and air flow rate; The electronic proportional adjustment burner has two dedicated motors, with independent servo motors controlling the flow of fuel and air. The low nitrogen 30mg burners currently required by the country are all electronic proportional adjustable burners.