The fan and cyclone were supplied to the mill by a major dust collector company as an exhaust system for a grinding mill. Fine particles were getting past the cyclone and building up on the fan wheel. This caused excessive vibration resulting in wheel and bearing failures as well as cracks in the fan housing and attached duct ork. The exhaust fan utilized a backward incline (BI) wheel. The grain mill contacted AEC to quote a replacement exhaust fan for one that had experienced repeated failures. The customer did not have the required fan performance data and was unable to get the original information from the fan supplier.
AEC was able to estimate an air volume and static pressure based on the general dimensions of the fan, the fan motor size (40 HP), the fan wheel type (BI) and the diameter of the cyclone. AEC’s original offering was for a fan sized for 10,000 – 11,000 CFM at 10”-12” w.c. static pressure. The local representative for the original dust collector provided a quote for a fan rated at 7,000 ACFM at 22” w.c.
AEC went to the job site to measure the air flow via a pivot tube to ensure we were offering the proper equipment. The fan was only accessible by climbing two flights of stairs and two 20’ vertical maintenance ladders. The measured flow was 11,500 ACFM at 10” w.c.
