These raw materials along with other products are chemically synthesized in manufacturing units to produce fertilizer compounds like ammonia, urea, ammonium phosphate, ammonium sulphate etc. The chemical processes also produce several by-products which in turn are used as the feedstock for other fertilizer plants. For instance the gaseous carbon dioxide (CO2) produced in the manufacture of ammonia is used in the making of urea. Hence the centrifugal fans and blowers used in the chemical & fertilizer plants need to be resilient handling products in several physical states like fluids, dry granular and gaseous forms. Several process fans are employed in de-dusting and fumes extraction, granulating and blending, pressurization and circulation of air, pneumatic conveying of chemicals or additives etc.
Scrubber Exhaust fans
Chemical and fertilizer plants face many challenges in the form of ammonia vapour emissions and urea dust from granulation plants and prilling towers. Scrubber exhaust fans are fitted at the top or alongside of the prilling tower to remove the urea dust emissions. Sometimes, dust scrubbers are also combined with acid washers to collect gaseous pollutants of ammonia emissions.
Fluidization Air fan
To produce fertilizer in the most usable form, different compounds are made into pieces such as dry granules and are blended together to make it as a fertilizer compound. In fluid bed granulation technology, large volume of airflow is required to supply the fluidization air. Here centrifugal fans are used to deliver air at a required velocity that is sufficient to carry the granulated particles to the fluid bed chamber for cooling. In fluid bed coolers, large centrifugal fans are used to circulate the air for cooling the granules.
The recirculation blowers of centrifugal type are mainly used in formaldehyde industry to increase the volumetric flow rate of process gas and supply air for oxidation processing. To overcome the pressure losses across the reactors, fresh air is pressurized, mixed with recirculation gas and is pushed through the process by recirculation blowers. This process gas is mixed with methanol and is passed into methanol vaporizer where the oxidation takes place in the presence of catalyst forming formaldehyde.