Fuel injector

Mechanical centrifugal fuel injector

With the pressure of the oil fed into the burner (2～3.9 MPa), the oil flows into the atomizing plate with tangential grooves from many small channels, and enters the vortex chamber in the center of the atomizing plate at a high speed. It rotates at high speed to spray out and form a hollow cone-shaped atomizing torch. This type of fuel injector has two forms: simple mechanical type and oil return type. The former has a simple structure, but poor fuel injection adjustability. When the boiler load changes, the oil pressure must be changed to change the fuel injection volume. However, if the oil pressure is lowered, the atomization quality is poor, so it is only suitable for boilers with basic load or without frequent load adjustment. The latter is to allow a part of the oil flowing into the vortex chamber from the tangential groove to flow through the oil hole to the oil return line before exiting the injection hole, and adjust the injection amount by changing the oil return amount (that is, oil return adjustment). Since the oil pressure entering the vortex chamber is basically unchanged, the atomization quality of the oil is not affected, so it can adapt to larger load changes. Oil return is divided into single hole oil return and porous oil return.

Steam atomization Y-type injector

The injection of high-speed steam flow is used to atomize the oil. The nozzle head consists of oil holes, steam holes and mixing holes to form a Y-shaped arrangement. The oil pressure is 0.5-2 MPa, and the steam pressure is 0.6-1 MPa. The oil and steam enter the mixing hole and collide with each other to form an emulsified oil-steam mixture, and then spray into the furnace through the mixing hole to form an atomizing torch. In terms of adjustment, maintain the vapor pressure unchanged and adjust the oil pressure to change the fuel injection volume. The oil burner is composed of a fuel injector and an air regulator. The former is used to form an atomizing torch into the fuel oil injected into the furnace; the latter is to supply the oil droplets in the atomizing torch with an appropriate amount of air. In order to prevent the oil and gas vaporized by the atomized oil droplets from cracking in the absence of oxygen above 700°C and producing carbon black particles that are difficult to burn, part of the air and oil mist must be mixed in advance to oxidize the oil and gas Without cracking. Therefore, the air regulator can be designed into a volute shape or equipped with guide vanes with adjustable opening to rotate the air, and then the rotating airflow from the circular pipe in the center of the volute is well mixed with the atomizing oil torch, as shown in the figure 1 shown. Oil burners, like pulverized coal burners, can be arranged on the front wall, front and rear walls, roof or corners of the furnace. According to the capacity of the boiler, each furnace can be equipped with 8-40 oil burners.