Surgeless Centrifugal Blowers


In many heavy-duty equipment applications, centrifugal blowers must perform consistently and reliably over a range of flow at or near constant pressure. Unfortunately, in this situation, conventional centrifugal blowers consistently fall short of reliable performance as a result of surge, which is an instability that develops between the blower and duct system during reduced flows and is generally characterized by periodic pressure fluctuations of 25 percent or more of the blower static pressure.

Surge is responsible for a host of problems, including:

  • Reduced controllability
  • Housing, wheel and foundation cracks
  • Failure of inlet and outlet connections
  • Unstable system airflow affecting burner pilots, process operations, flow measuring equipment and vibration detectors
  • High, irregular fan noise

The Robinson Surgeless Blower

Engineers have wrestled with the problem of surge for decades, trying to find a method or a device to prevent it or counteract its effects. More recent attempts to reduce surge by recirculating air internally or redirecting excess air to an external vent have not been completely successful, as they waste valuable energy.

But Robinson Fans has developed a new centrifugal blower that eliminates surge and its damaging effects. Pressure fluctuations will be reduced to 10 percent or less of the blower static pressure. While most conventional blowers perform well at normal ratings, they experience surge during the “turndown” many applications require. Unlike conventional blowers, the Surgeless Blower offers stability over a broad range of operation cycles.

For Demanding Applications in Diverse Industries

The Surgeless Centrifugal Blower will minimize the problem of surge in all types of industries, for a wide range of applications. The Surgeless Blower can be built to stand tough in corrosive, abrasive and high-temperature environments. In forced draft service, the blower performs reliably in heat recovery, incineration, air pollution and waste-to-energy systems, as well as in boiler, fluidized bed, combustion air and process air operations.

Standard and Optional Features

Robinson blower housings are manufactured from high-grade steel material. Cast aluminum wheels with taper lock hub construction are standard with the Surgeless Blower, as are afixed inlet screen, outlet flange and fixed housing. Inlet or outlet dampers and silencers are optional items. All blowers are statically and dynamically balanced.

For high-temperature conditions or applications requiring extra corrosion resistance, housings and wheels fabricated from special alloys are available.

Other options include:

  • Shaft seals
  • Silencer
  • Inlet filter
  • Inlet damper
  • Flexible connector
  • Inlet flange

How to select the right surgeless blower for your application

1. Find the required static pressure and volume in the shaded area on the upper section of the selection chart

2. Follow up from this point along the corresponding system resistance curve until it intersects a fan curve. Several arbitrary system resistance curves are shown dotted for reference.

3. The intersected curve represents the performance of the blower size required. The point of intersection will be the actual operating performance of the blower in your system.

4. Read straight down from this point to the corresponding BHP curve on the lower section of the selection chart. The point of intersection shows the actual BHP that the blower will require in operating your system.


1. Required 225 cfm and 17″ Ps at 70 degrees F.

2. Follow up system resistance curve to SB-A-172 curve.

3. Actual operation will be 240 cfm and 19.4″ Ps.

4. The required power of the SB-A-172 blower at 240 cfm is 1.38 BHP.

Note: Due to variations in system resistance, inlet density and other operating conditions, Robinson recommends that a motor be selected with at least 10 percent more HP capacity than the required blower BHP.

Primary Industries Served

  • Steel
  • Mining
  • Cement
  • Ceramic
  • Chemical
  • Woodworking

Typical Air-Moving Applications

  • Building ventilation
  • Fume removal
  • Dust removal
  • Dust collection
  • Pneumatic conveying
  • Oven and dryer exhaust
  • Combustion air
  • Incinerators
  • Heat recovery