Rotary Air Preheater Pdf

It was observed that gas side efficiency gradually increased as the area between air to the gas side between the rotor and the air preheater housing decreases. The velocity of cold air is measured for a range of Reynolds number based on which the fanning friction factor, pressure drop and heat transfer coefficient of the plate profiles are calculated.

The flue gas coming out of the furnace is dust-laden containing contaminants such as chlorides, sulphates etc. Regenerative heat exchanger. Further, due to dust-laden abrasive flue gases, the tubes outside the ducting wear out faster on the side facing the gas current. An electrical heating coil made of resistance wires may be applied for this purpose.

The challenge

As the flue gas attains the acid saturation temperature, i. Toggle navigation contact us. Ljungstrom heat exchangers for waste heat recovery.

Hence frequent replacements are called for and new baskets are always kept ready. The diffuser takes the flow from the test section and discharges it into the atmosphere at a relatively high pressure. Let us know you agree to cookie.

It is the time taken by air to travel from one side of the element to another. Low pressure drop is preferred for better performance of an air-preheater. This allows the axial seals to run the full length of the rotor, and so helps to minimise leakage.


Using specially developed software, we can precisely model the conditions under which the air preheater will be working. The plates or heating elements are kept in the middle test section. As the rotary air-preheater operates at a relatively high temperature, the matrix wall will expand on coming in contact with the flue gas and shrink on contact with cold fluid. To minimise leakage over the whole lifetime of the units, we equipped them with fixed sector plates and triple sealing. Published by Magnolithe GmbH.


The driving unit consists of a Fan, Blower or a Compressor connected to an electric motor. You can change country below.

Analysis on Thermal stress deformation of Rotary Air-preheater in a thermal power plant. The testing of heat transfer surfaces of various profiles is done so as to find out the profile which optimizes the heat transfer characteristics and efficiency of an air- preheater. Inside the ducting, the hot furnace gases pass around the preheater tubes, transferring heat from the exhaust gas to the air inside the preheater. The coal particles inside the furnace require minimum ignition temperature to catch fire and stoichiometrically required quantity of air with proper inter- mixing. It indicates maximum heat is recovered in the air pre heater.

So here leakage is by virtue of pressure difference. This reduced the overall downtime.

Safety protected inspection windows are provided for viewing the preheater's internal operation under all operating conditions. These features mainly depend upon the profile of heating elements used.

In other projects Wikimedia Commons. The rotor is built up on the vertical shaft with radial supports and cages for holding the baskets in position. In particular, this article describes the combustion air preheaters used in large boilers found in thermal power stations producing electric power from e. Evaporators and Condensers. Your local Howden contact The below contact s are the representatives for your country.

Local instrumentation of the gear drive completed. At the request of the Itabo plant operators, the units were pre-assembled at our factory and securely shrink-wrapped before transit, to prevent damage. The changes this brought about in the composition of the flue gas led to increased fouling and a serious risk of fire. This greatly reduces the cost of the project and the time taken for installation and commissioning. After the heating, cold air passes through, heat gets transferred from the plates to the air hence a temperature rise of cold air is noticed.

You can, of course, opt out of these communications at any time! The wear of the baskets therefore is generally more than other, cleaner-burning fuels. When such a wire is introduced into the flow of a gas it cools down the hot wire to a lower temperature due to convective heat transfer from the wire element to the gas. The idea is that as hot exhaust gases flow through the checkerwork, they give up heat to the bricks. Dew Point Corrosion is a problem generally seen in all kinds of air-pre heaters.

It is installed between the economizer and chimney. This chamber supplies the flow to the converging section located downstream. For on line cleaning of the deposits from the baskets steam jets are provided such that the blown out dust and ash are collected at the bottom ash hopper of the air preheater.

Corrosion and viscous ash deposition of a rotary air preheater in a coal-fired power plant. Instead, convertir page html en pdf en ligne the ducting system of inlet air and outlet air is made rotary so that all the plates are exposed to both hot and cold air.

Our solutionThe challengeItabo I - Replacement of primary plate heaters

In addition, the velocity of gas flow through the matrix should be also measured. Path A and B represents circumferential leakage. Tri-sector types are the most common in modern power generation facilities. Please let us know if you agree to all of these cookies. Please complete the fields below to get your copy.

Leakage drift refers to the increase in leakage of air to flue gas due to the deteriorating condition of the sealing system used. In this way we ensured the air preheaters had the right balance of characteristics to overcome the problems that the plate heater had encountered. Semi-retractable soot blowers were fitted to both the hot and cold sides for effective, efficient cleaning. Application to air-preheater. Many advances have been made to eliminate this problem such as the use of ceramic and hardened steel.