A typical supply fan or impeller (wheel) can be described by the blade constructions. The distinguishing characteristic is the shape of the individual fan blades and their orientation relative to wheel rotation. The airfoil (AF) fan has contour blades that curve away from the direction of rotation. The backward incline (BI) fan is slightly less …
A centrifugal blower impeller have backward swept blades, radial tipped blades or forward swept blades as shown in figure: 1.1 below. The inlet and outlet velocity triangles are also shown accordingly in the figure. Under ideal conditions, the directions of the relative velocity vectors Vr1 and Vr2 are same as the blade angles at the …
Blower is power consuming machine, where large volumes of gas or air at low pressure are required. According to the “Compressed Air Institute”, it is a machine to compress air or gas by centrifugal force to a final pressure not exceeding 2.4 bar. It is not water cooled, as the added expense of the cooling …
Blowers and compressors these are actually air handling devices or machinery which one will come across in many plants and industries. So the working fluid in blowers and compressors is air or gas see this fluid handling devices are very similar in they are out say principle or in philosophy in comparison with electrical machines …
Compressors, Blowers, Vacuum Pumps and Their Performance Characteristics Read More »
Basic Principle Like most other rotating machinery, fans experience wear and require periodic maintenance and repairs. Dynamic surfaces in bearings and belt drives degrade over time. Fan blade surfaces may erode from abrasive particles in the airstream, and motors eventually require replacement or rewinding. Although some degree of wear is unavoidable, operating the system at …
The requirements for attaining a minimum level of fan energy efficiency and keeping the fan selection with an operating point close to the fan peak energy efficiency are being addressed in a recommendation for continuous maintenance proposal for ASHRAE/IES Standard 90.1. The proposal for this recommendation was made by ASHRAE Technical Committee 5.1, Fan Design …
Select Fans Using Fan Total Pressure to Save Energy Read More »
A centrifugal impeller with forward-curved blades produces more cfm and more static pressure at a given rpm than either radial or backward-curved impellers. Consequently, forward-curved centrifugal fans are popular in domestic equipment, where space is often at a premium and noise must be kept to a minimum. Forward-curved centrifugal fans display a typical “dip” in …
Maintenance Items Common maintenance tasks on fan systems include: Periodic inspection of all system components Bearing lubrication and replacement Belt tightening and replacement Motor repair or replacement Fan cleaning The most costly consequence of improper maintenance is unscheduled downtime. Causes of this downtime vary according to the demands of the application. Because each system places …