Howden Air Preheaters Quadsector

Quadsector air preheaters Power boiler applications require highly efficient and reliable air preheaters to ensure optimum boiler performance. An air preheater with one gas duct , one primary air and two secondary air ducts is called a quad-sector design. Read more about quad-sector air-preheaters below. The quad-sector design is available with the primary (high pressure) system fitted between two normal secondary air sections. This gives a reduction in leakage but at a higher initial cost for both the heater and the air ducting. Key benefits Low capital investment Rotary regenerative air preheaters have a much reduced size and cost relative to recuperative tubular or plate heat exchangers. Low leakage level without drift Most new air preheaters can achieve leakage levels that are close to their design values after initial commissioning or when set up correctly after an outage. However, after a period of operation of up to 2 or 3 years, the leakage can increase dramatically, typically from 5% - 12% on secondary preheaters and to between 12% - 25% (and frequently higher) on high pressure mill preheaters. Extensive choice of heat transfer elements Howden have designed and developed an extensive range of heat transfer elements over the years. Combinations of elements are selected to optimise performance, pressure drop and cleanability for the given fuels Low maintenance Conceptual and detailed design targets the achievement of simplicity and minimal maintenance. Fixed sealing surfaces and centre drive greatly reduces maintenance by removing actuators and pin racks. High availability The major cause of reduced availability in air preheaters is due to element fouling. Careful element selection to suit the application, cold end temperature control and the application of the correct cleaning system maintains very high availability. Centre column or bottom girder support Custom designed and optimised to suit arrangement and client preference. Standard features All air preheater types can have a vertical shaft and horizontal rotor arrangement and are termed vertical air preheaters as the rotor shaft is vertical.