Air Preheater Manufacturers

EEI has designed, manufactured and supplied air preheaters with the heating value from 4000 kcal/hr to 80,90,000 kcal/hr.

An Air pre-heater is designed to preheat air before another process with the primary objective of increasing the thermal efficiency of the process.

The Air pre-heating helps in Igniting the fuel, Improving combustion, Reducing the stack gas temperature and increasing the boiler efficiency. Stability of Combustion is improved by the use of hot air through the Air Preheater. Due to High heat transfer rate in the furnace and lesser heat transfer area required. There will be lesser un-burnt fuel particle in flue gas so the combustion efficiency is improved.

To maximize the boiler efficiency the useful heat has to be removed from the gas from the APH. However certain minimum temperature has to be maintained in the flue gas to prevent cold end corrosion. An air preheater heats the combustion air where it is economically feasible.

Air preheaters can be classified as Recuperative Air Preheaters and Regenerative Air Preheaters types based on their operating principle.

In recuperative Air preheaters, the heating medium is on one side and the air is on the other side of the tube or plate and the heat transfer is by conduction through the material which separates the media. In regenerative Air preheaters type the heating medium flows through a closely packed matrix to raise its temperature and then air is passed through the matrix to maximize the heat.

Steam Coil Air Preheater (SCAPH)

EEI has supplied Steam Coil Air Pre-heater (SCAPH) having heating value from 15500 Kcal/hr to 35,45,900 Kcal/hr.

Steam coil air preheaters (SCAPH) are used to heat air entering the air heater recuperative or regenerative type, in order to raise the average cold end temperature to prevent acid dew point corrosion.

Finned types SCAPH are widely used to increase the air temperature from ambient to the requisite temperature level by means of saturated steam as heating medium. Steam flows inside the tube while air passes over the finned tubes.

SCAPH is used with High Capacity Boilers, Recovery Boilers, and Dryers for heating process-air in Sugar Manufacturing, Chemical & Allied Industries

SCAPH is normally incorporated into the design of a boiler unit for low load operation and startup operation particularly in those areas with low ambient air temperatures. They are desirable in that the main air heaters, recuperative or regenerative, have corrosion sections that are more readily maintained.  Finned type SCAPH type of air heater uses extended surface, normally referred to as fins, to reduce the overall size of the air preheater. It is generally located in the duct between the FD fan and the main air heater; it is common to have this ahead of the FD fan that could preheat cold winter air up to about 40 degrees F.

Recuperative Tubular Air Preheater

EEI has designed and manufactured Tubular Air Preheater with heat duty ranging from 4000 kcal/hr to 80,90,000 kcal/hr.

The heat is recovered by the air from the hot gas flowing across the air preheater. These type of air preheaters are is enclosed rectangular type construction consisting of several large number of steel tubes of 40 to 65 mm dia. connected or expanded into the tube plates. Flue gas which is the heating medium passes through inside of the tubes and the air passes though the outside of the tubes. The heat transfer surface is large due to low heat transfer coefficient between flue gas and air. Vertical flow is suggested to avoid fouling.

Tubular air preheaters and Tubular Air Preheater with baffles are designed, manufactured and supplied to various boiler industries as heat recovery units and also to supply hot combustion air to the furnace. with the following details for techno- commercial offer
Type of Air-preheater required; plain tube/ finned tube
Heating medium- steam/ flue gas/ hot water/ gas, quantity, pressure and flow of the medium
Heated fluid Air- quantity, pressure and flow