Venturi Blowers – A Comprehensive Guide

Venturi blowers, also known as Venturi vacuum or Venturi ejectors, are air-moving devices that operate based on the Venturi effect. They have a narrowed passage (venturi tube) to induce air acceleration.

Basically, these blowers extract dust, fumes, smoke and hazardous gases from tanks, manholes, tunnels and confined structures. Moreover, they find wide applications in refineries, utility & power facilities, shipyards and paper & pulp plants.

How Does A Venturi Blower Work?

  • At first, the air velocity increases while passing through the converging nozzle, causing a drop in pressure.
  • Later, the low-pressure area within the blower’s neck draws in the surrounding air.
  • The combined air stream then passes through the diverging portion.
  • Finally, it decreases speed and increases pressure, producing a high-pressure exit flow.

How to Choose a Venturi Blower?

Raptor Supplies offers venturi blowers from a range of manufacturers such as Air Systems International, Texas Pneumatic Tools and Allegro Safety. Additionally, we have created a comparison guide to help you select the product that precisely matches your specific requirements.

Based on the Material of Construction

  • Are your workers regularly exposed to ammonia, chlorine and hydrogen chloride / bromide? If yes, then we highly recommend Air Systems International galvanised steel corrosion-resistant venturi blowers.

  • Allegro, on the other hand, focuses on both metallic and plastic venturi blowers. While the metallic variants (galvanised construction) are beneficial for corrosion resistance (similar to ASI venturi blowers), the plastic units, are made of LLDPE and can withstand heat up to 220 degrees F. So, if you need corrosion-proof blowers, you can explore Allegro’s corrosion-proof venturi blowers. Or, if you require high-temperature tolerance, then their heat-resilient venturi blowers are worth considering.

Based on Performance

AirFlow (CFM)Allegro Safety
(Galvanised Steel)
Allegro Safety
Air Systems International
< 20009518-03 & 9518-03S 9518-13 & 9518-13SASI-1000 & ASI-1200
2000 – 40009518-069518-16ASI-2900
4000 – 60009518-089518-18ASI-4100
> 60009518-10

Based on Price

Allegro venturi blowers range in price from roughly $300 (Allegro 9518-13S) for the 1200 CFM model to around $1000 (Allegro 9518-10) for the powerful versions that create 8220 CFM.

Air Systems, on the other hand, manufactures devices with similar setups but at a lower cost. Their base model (with 1400 CFM) starts at around $270 (ASI-1000). Furthermore, their premium variant which delivers 5000 CFM, costs roughly $730 (ASI-4100).

How to Calculate What Size Venturi Blower You Need?

  • Firstly, calculate the volume of the container you wish to ventilate
  • Then, determine the ASHRAE recommended outdoor ventilation rate with the table on the right.
  • Finally, use the formula below to calculate the required CFM.

So, whether you’re an engineer, a facility manager or an aspiring enthusiast, we are here to help you select the perfect venturi blower for your specific requirement. Raptor Supplies Limited, a trusted international distributor of Allegro Safety and Air Systems International, offers these venturi blowers to customers in the UK, Europe, the Middle East, as well as Asia.
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