Hava Isıtıcılar (Luvo)

In air heaters, the combustion air is heated by smoke gases. Fuel savings and better combustion are achieved. Heating the air every 50 degrees provides 2.5% savings in fuel. Air heaters are used in heat, steam, power generation plants to recover the heat in the flue gas in steam power plants. This recovered heat can be given to the fresh air used as boiler combustion air. In addition, heating, cooking, drying and so on. can also be used in processes. In the air heater, depending on the type of fuel burned, flue gas temperatures greater than 200 degrees can be used economically.

Benefits of using an air heater in heat, steam or power generation facilities;

• Depending on the flue gas outlet temperature and fuel type, an efficiency increase between 3% and 7% is achieved in the plant efficiency.
• Less fuel consumption for the same capacity, more heat generation for the same amount of fuel consumption.
• The use of preheated air especially in medium and large capacity boilers increases the furnace temperature, combustion efficiency, and the radiation efficiency of smoke gases.In addition, air heaters are recommended for solid fuel burning boilers with a simple structure, easy cleaning, low investment costs.

Air heater application areas (areas of use of recovered heat)

Air heater application areas (areas of use of recovered heat)

• Preheating of combustion air
• Heating an area close to the boiler room,
• Heating of the air used for heating, cooking, drying etc. in the facility. The excess of heat recovered in an air heater depends on the boiler flue gas outlet temperature and the exit temperature of the flue gas from the air heater.

The greater the difference in gas temperatures entering and leaving the air heater, the greater the heat and efficiency recovered. The flue gas outlet temperature varies depending on the boiler's operating regime, boiler efficiency, boiler-burner compatibility, and fuel type. The type of fuel used and the operating conditions of the fluid to which the heat will be transferred determine the exit temperature of the air heater.

As in the economizer, the smoke gases are cooled a little more in the air heaters, providing fuel economy and a better combustion. Heating the air approximately 50 degrees more provides 2.5% economy in fuel. The air should be heated between 150 and 320 degrees for a better burning in coal fired furnaces.

Because the heat transfer coefficient in air is worse than water, more ash is formed on the surfaces of air heaters than economizer. Sometimes these ash formations are a disadvantage for the air heater. Flammable dusts that can mix with hot air can cause damage. Therefore, it is more important to eliminate the ash density in air heaters. In case sonic soot blowers operate frequently, it is quite easy to eliminate the ash density.

Past İnstallation:

The Gorgas Steam Power Plant has a Ljungstrom air heater equipped with Sonic horns.

Ash accumulation problems caused the differential pressure on the air preheater to rise higher and faster than normal. Installing 2 sonic horns on both gas and air inlets solved the problem of increasing differential pressure.

Installation of air preheater

Rotary air preheaters have a speed of 1 rpm. The picture below shows the estimated cleaning area of the air preheater with a diameter of 9 meters. The graph shows that the differential pressure in the air heater is kept at an acceptable level using sonic horns. When the air inlet of the sonic horns was closed, the differential pressure increased rapidly.