Volute assembly and induced draft fan comprising the same

A volute assembly, comprising:

• a volute body, the volute body comprising a top plate, a side plate protruding axially from an edge of the top plate, a cavity formed by the top plate and the side plate, and an exhaust duct disposed on the side plate and communicating with the cavity;
• a cover plate, the cover plate comprising a bottom plate and an annular sleeve surrounding the bottom plate;
• and
• a seal;
• wherein:
• the side plate comprises a first bottom edge and a plurality of clamping blocks disposed at intervals on the first bottom edge;
• the annular sleeve comprises a second bottom edge and a flange protruding from the second bottom edge;
• the flange comprises a plurality of buckles disposed at intervals;
• the seal is disposed around the annular sleeve and is supported by the flange;
• the side plate is matched with the annular sleeve in shape;
• when the cover plate is disposed on the volute body, the annular sleeve is nested in the side plate and the plurality of clamping blocks is secured to the plurality of buckles, respectively, to fasten the cover plate to the volute body, whereby the seal abuts against the side plate and the flange, achieving a sealing effect.