Types of Burners
In the marine industry, gas and oil-fired marine boilers both utilise the controlled combustion of fuel to heat water. The burners in the boilers are involved in this combustion, along with the other components in the boilers such as the combustion chamber, heat exchanger, and controls.
To understand how burners work, we must first understand how the boiler works. In the boiler, the burner will first mix the fuel and oxygen together evenly for combustion to take place. Combustion is a chemical process whereby the fuel reacts rapidly with oxygen in the air to produce heat energy. The process will take place in the combustion chamber, where the heat generated is channelled to the water through the heat exchanger. The hot water produced will be distributed via pipe channels to the required equipment throughout the vessel.
There are 4 different types of gas burners, namely the atmospheric, power, forced & induced draft and premix & pressure power. They differ purely based on design. Atmospheric gas burners use air at atmospheric pressure to be mixed evenly with the gas before combustion. Power burners, on the other hand, require a blower to provide air for combustion and are commonly used for commercial or industrial application. This is good where variation is necessary to meet requirements for port loading, number of ports, length of mixing tube, height of burner head or air shutter design. It is also easy to troubleshoot or maintain, and it allows flexibility for a variety of gases.
In general, fuel oil burners can be classified as atomizing burners, vaporising burners and rotary-type fuel oil burners.
Atomisation is done in oil burners to assist the homogenous blending of oil and air to stimulate full combustion. With steam injection, the oil is reduced to a fine spray that mixes with the air and burns easily. There are 3 different types of atomisation that can be done, namely:
1. High Pressure atomisation / Spray
Gun-type Atomising Burners
A gun-type burner atomises the fuel oil by forcing the oil through a nozzle and spraying it onto a gun-like airflow atomic nozzle. The liquid forms microscopic particles which become well-mixed and partially evaporated before being ignited in the combustion chamber.
The atomising burner is very versatile and can be used for an array of applications, ranging from small residential heaters to larger industrial heating applications.
2. Low Pressure atomisation / Rotary
Rotary fuel burners
Rotary fuel burners use the principle of centrifugal force and operates with low-pressure gravity. The fuel oil is placed on the rotary disc and the centrifugal force converts it into a fine spray. The nozzle assembly rotates at high speed and the oil is supplied from the shaft. Various types of rotary oil burners are available on the market, such as vertical rotary burners, horizontal rotary burners and wall-flame rotary burner. It has tremendous advantages in industrial applications.
3. Steam and Air atomisation / Dispersed
Pot-type Vaporising Burners
In vaporising burners such as natural draft burners, forced draft burners and sleeve burners, the fuel evaporates into the combustion air. These vaporising burners differ in the way air supply is received. The natural draft burner relies on the draft in the chimney for air supply, whereas forced draft relies on mechanical fan or a combination of both for air supply.
This type of burner is the most affordable and inexpensive of all the mentioned fuel oil burners with the lowest operating cost. However, due to the limited capacity of the burner, it is most suited for smaller applications.
Ultimately, the types of burners that you use should fit the purpose that it is intended for. You should always consider factors such as the design, cost, type of application before selecting the burner or boiler.
This article is brought to you by Giantech Engineering Pte Ltd. Find out how Giantech may help meet your vessel’s burner needs: https://www.igiantech.com/services/boilers-burners/