How to maintain the combustion temperature of a dual-purpose oil and gas burner - self recycling burner

How to maintain the combustion temperature of a dual-purpose oil and gas burner

The dual-purpose oil and gas burner is a manifestation of modern combustion technology in the industrial combustion equipment industry. The injection speed of high-temperature combustion products at the outlet can reach 100m/s to 300m/s, and it has technological advantages such as energy conservation and controllable flame momentum. It has been widely used in various heating furnaces in industries such as steel, chemical, and light industry in developed countries.

The dual-purpose oil and gas burner consists of an oil nozzle and an air regulator. The oil nozzle is placed on the axis of the air conditioner, atomizing the oil into fine droplets and spraying them into the combustion chamber at a certain diffusion angle (also known as atomization angle). After mixing with the air sent by the air conditioner, it ignites and burns. There are two main types of oil nozzles: pressure atomization and dual fluid atomization. The pressure atomization oil nozzle consists of a splitter, a swirl plate, and an atomization plate. The oil pressure is generally 2-3 megapascals.

The oil generates high-speed rotational motion inside the swirl plate, is sprayed out through the central hole, and is broken into fine droplets under the action of centrifugal force. The average diameter of the atomized oil droplets is below 100 microns. The dual flow atomizing oil nozzle uses steam or compressed air as the atomizing medium to accelerate the oil and break it into atomization. The Y-shaped oil nozzle, which uses steam as the atomizing medium, is named after the oblique intersection of the steam and oil channels in a Y-shape. The dual-purpose oil and gas burner has the advantages of a large load adjustment range and low steam consumption.

In order to achieve combustion, a dual-purpose burner for oil and gas allows gas and air to enter the combustion chamber through numerous nozzles. The gas jet and air jet collide one by one and mix evenly. The vector direction of the synthesized jet should be parallel to the main axis of the combustion chamber to avoid one jet penetrating the other jet and causing uneven mixing. In order to reduce the generation of NOx, zone combustion is adopted. The combustion temperature in the front zone is lower than that in the back zone, and the combustion temperature at the outlet of the combustion chamber is higher.

The front zone is for lean oxygen combustion, while the rear zone increases oxygen supply, achieving an excess air coefficient of α=1 at the outlet of the combustion chamber. This design can not only reasonably distribute air, ensure full combustion, prevent CO generation, but also maintain a lower combustion temperature and reduce the generation of harmful gas NOx. The combustion chamber wall cooling chamber is filled with high-temperature combustion products, and the metal chamber wall must have sufficient cooling in order to work safely.

In the design, air is utilized to flow through the combustion chamber and absorb the heat conducted by the chamber wall, ensuring that the chamber wall operates within a safe temperature range. Simultaneously preheating the air can promote full combustion and increase the theoretical combustion temperature. In the local high-temperature area of the combustion chamber nozzle, an air film is specially designed to protect the metal wall. Due to the adoption of the above design, the service life of the dual-purpose oil and gas burner can reach 3 years.