Housing of centrifugal fan, centrifugal fan and clothes dryer

A housing of a centrifugal fan, comprising:

• an air duct of the housing is-provided with a layering structure,
• wherein the layering structure is arranged to be able to divide at least a part of the air duct into at least two wind layers, and a width of the wind layer close to a strong wind end is larger than a width of the wind layer close to a weak wind end:
• wherein the layering structure is arranged close to an outlet end of the air duct;
• wherein the layering structure is a layering platform attached to or formed on an inner wall of the housing, and the layering platform divides the air duct into a first wind layer and a second wind layer, and wherein the first wind layer is close to the strong wind end, and the second wind layer is close to the weak wind end;
• wherein a windward end of the layering platform has a smooth transition with the inner wall of the housing;
• and
• wherein a cross-sectional width of the layering platform gradually increases in a direction in which a gas flows from the windward end toward an outlet end of the air duct.