Structure Analysis of the Collector and Impeller in Stainless Steel Insulated Fans

Structure Analysis of the Collector and Impeller in Stainless Steel Insulated Fans

In stainless steel insulated fan assemblies, the collector assembly and impeller are critical components. Their function is to uniformly introduce gas into the impeller with minimal loss. Currently, stainless steel insulated fans typically employ four collector types: cylindrical, conical, circular, and nozzle-shaped. Compared to others, the cylindrical collector's primary advantage is ease of fabrication, but it suffers from significant losses and poor rotational flow into the impeller. The conical collector is slightly better than the cylindrical type but still suboptimal. The arc collector outperforms both initial types and is widely adopted in practice. The hyperbolic collector exhibits lower losses and provides excellent rotational flow to the impeller. Its drawbacks include complex processing and high manufacturing demands, making it prevalent in high-efficiency centrifugal fans. For stainless steel insulated fans, the impeller is a critical component. Simultaneously, the propeller's dimensions and collector shape directly impact the machine's performance. Typically, the impeller consists of a front cover, rear cover, blades, and hub, usually welded and then secured with rivets. The impeller front cover includes flat plates, Konica front plates, and curved front plates. Flat front plates are easier to manufacture but adversely affect airflow, reducing efficiency. Conversely, while Konica front plates and curved front propellers involve complex manufacturing and machining requirements, they deliver excellent operational efficiency and impeller strength. Blades constitute the primary component of the impeller. Their exit angle, shape, and quantity significantly influence the operation of stainless steel insulated fans. Based on blade outlet angles, stainless steel insulated fans can be categorized into three types: forward-curved (bending forward), radial, and backward-curved (bending backward). At identical peripheral speeds, larger blade outlet angles generate higher pressure. Consequently, for two centrifugal fans of identical size and speed, the forward-curved propeller achieves higher pressure than the backward-curved propeller.