Material selection method of centrifugal fan
For centrifugal induced draft fan conveying high temperature gas, the change of material under high temperature is mainly considered, and general materials can not be selected.The mechanical properties of ordinary carbon steel decrease rapidly when the temperature exceeds 300 degrees.Therefore, when the medium temperature is greater than 300 degrees should choose heat-resistant materials, and when the medium is greater than 700 degrees, should choose high temperature resistant alloy steel, that is, pay attention to the selection of nickel, chromium steel.
In order to avoid accidents, when the fan conveying flammable and explosive gas medium of low grade, the fan casing can be made of steel plate, the impeller is made of aluminum material, so that when the aluminum impeller and steel casing collision or friction, can not spark and cause accidents.However, when the fan conveys flammable and explosive gas medium with high grade, the impeller and casing of the fan must choose aluminum material.
If the centrifugal induced draft fan in its transmission medium, contains a certain amount of dust, sand or granular material, such as coal, sand and similar substances, at this time if the general fan is selected, it is necessary to install dust removal device before the fan inlet, so that the dust content in the gas is less than 150g/m3.If the dust removal effect is not up to the requirements, or the dust directly passes through the fan due to the system design requirements, wear-resistant fan should be considered.
Corrosion resistant centrifugal fan main conveying medium contains corrosive substances, such as acid, alkali, salt and other corrosive chemical gases.The fan should consider the main problem is the corrosion resistance of materials, generally can choose ferrosilicon alloy or aluminum alloy and nodular cast iron, also can use spray technology.