Elements
Howden supplies replacement element baskets for rotary regenerative heat exchangers, (rotating or stationary matrix types), irrespective of original manufacturer. Over the past decade Howden has won more than 2000 contracts to supply replacement elements for boiler air preheaters and FGD gas reheaters.
With a range of over 45 different profiles, we supply direct replacements of all element types commonly used in rotary heat exchangers.
Our expertise enables us to recommend alternative profiles or arrangements. This can improve the performance of the regenerative heat exchanger, particularly if the operating conditions have been changed since the original elements were specified.
The elements range from those with simple "open" profiles that avoid fouling but have less effective heat transfer, to more compact, complex profiles that induce turbulence in the gas flow to improve heat transfer.
Elements are available in a number of materials including carbon steel and Corten. Enamelled elements are provided when firing high sulphur / low ash fuels, where sited downstream of an SCR
DeNOx plant, or for FGD gas reheaters.
Corrosion can occur in enameled elements as a result of enamel porosity, enamel cracking, incomplete edge coverage and poor acid resistance. Our enameling processes have been specifically developed for rotary regenerative heating elements to ensure maximum element life. They provide lower porosity, high acid resistance and superior edge coverage for FGD gas-gas heater applications and finer tolerances on coating thickness with smoother enamel surface for air preheater applications downstream of SCR plant.
Elements can be supplied in a variety of baskets including those of our own design. We manufacture baskets so that the elements remain tightly packed. This avoids damage that could be caused by vibration while the air heater or gas-gas heater is operating.
We pay particular attention to this in the case of enameled elements, as the extra excitation during cleaning can cause significant damage. Our advanced SurePack Elements® basket packing system controls the packing pressure within tight limits to prevent excessive vibration and increase life.
We offer a range of element cleaning devices, specifically selected for each application, that maintain full performance throughout the life of the elements.