Types of air preheaters and its advantages

1. Types of air preheaters and its advantages?

2. Index • What is Air preheater • Types of air preheaters • Regenerative or Tubular type • What do you mean? Regenerating or feeding, giving water • Advantages of Air Preheater

3. Air Preheater

4. What is air preheater • An air preheater (APH) is a General term to describe any device, the air before another process is heated (e.g., combustion in a boiler) with the main objective to improve the thermal efficiency of the process.

5. Air pre-heating can increase boiler efficiency and reduce chimney loss. They can be used alone or replace a heat recovery system or replace the Steam coil. • An air preheater (APH) is a device used in steam boilers to transfer heat from the flue gases to the combustion air before it enters the oven. • Air preheater recovers the heat from the boiler flue gas and increases the thermal efficiency of the boiler . • The flue gases are fed into the combustion gas stack at a lower temperature to control the temperature of the gases.

6. The combustion air preheaters are used in large boilers in thermal power plants to generate electricity from such fossil fuels, biomass or waste. • The purpose of the air preheater heat recovered from boiler flue gases that increase the boiler thermal efficiency by reducing the useful heat lost in flue gases. • As a result, the flue gas is also sent to the stack flue gas(or chimney) at lower temperatures, making simplified construction of duct and exhaust stack. • It also allows control over the temperature of the gas leaving the stack (to meet emissions regulations, for example,)

7. Types of air preheaters • There are two basic types Of air preheaters • Rec recuperative or tubular typert

8. 1. Regenerative or Tubular type • Recuperative type of air Preheaters is preferably used in small and medium boilers. In this type, the heat energy exchange is carried out through the walls of the heating surface, which separate the heat energy carrier and the air to be heated. • The ambient air is pressed by a fan through the conduit at one end of the preheater tube and at the other end, the heated air from the interior of the tubes into another set of conductive tube Preheaters out of straight bundles of tubes passing through the exit line of the boiler and open at each end outside the conduit.

9. The hot furnace gases go around the preheater pipes inside the pipe, which transfers that it carries into the furnace of a boiler for combustion. • http://www.maniks.com/manufacturer/air-preheater/

10. 2. What do you mean? Regenerating or feeding, giving water • In feed water preheaters, the exchange of heat energy is effected by alternating heating and cooling of metallic or ceramic nozzles of the solid or rotating heating surfaces. Regenerative air Preheaters are compact and can have a stationary Rotary hood. • Combined use of recuperative and regenerative type • The applications of very high capacity boilers used a combination of tubular and regenerative type of air preheater.

11. For such applications, the primary air heating is carried out by tubular type and the secondary air heating is carried out by regenerative type. • If the boiler designers do not want to use the combination of recuperative and regenerative air preheater, they can go for the tri-sector regenerative air heater.

12. Advantages of Air Preheater • For heating the air it uses heat energy of flue gases hence there are many more advantages of Air preheaters over the normal preheaters such as • Increases thermal efficiency of the system • Payback period is very short and increase combustion rate • Improve and strengthen the combustion • Reduces the loss of furnace and the exhaust gas temperature, improve the boiler thermal efficiency.

13. Air preheater is suitable for all standard fuels • They are easy for retrofit into existing systems • These air preheaters are suitable for all waste heat boiler / flue gas boiler / boiler types. • They strengthen the heat transfer • Visit us: • http://www.maniks.com