Positive Displacement Aeration Blower Packages

Our innovative positive displacement blower packages (PD blowers) are state-of-the-art and best suited to maximize productivity and minimize energy costs for environmental applications such as municipal wastewater treatment. Discover more by clicking the product cards below. 


Our PD blower is an integrated package designed to convey gas at low pressure. It is based on a positive displacement rotary air blower, operated by an electric motor through a belt drive, including all accessories and a noise enclosure.

Our HOFFMAN DEFENDER series of PD Lobe and Screw blower packages means reliability, extreme sturdiness, and compactness. In a competitive global market, our long history of supplying blower solutions to suit our customers' unique requirements sets us apart from the rest. Using modern machining systems and state-of-the-art production processes, our product range is constantly evolving. We offer local service capability, ensuring our advanced technology is backed by technical support.


HOFFMAN Rotary Lobe positive displacement blower packages convey a relatively constant volume of gas from the inlet to the discharge point. It follows the isochoric compression principle also known as external compression. 

In this medium like gas or air is forced from an atmospheric condition into a system with a given resistance, such as back pressure to achieve the relevant pressure increase. For this reason, Rotary Lobe PD blowers are not considered compressors. The amount of gas the machine handles is fixed by the configuration of its casing and rotating parts. 

Our Lobe PD blower has a capacity of up to 6,121 cfm to meet the various needs of our customers and their range of municipal wastewater applications. This is an excellent solution for the oil-free conveyance of air and neutral gases. It is equipped with a low-pulse system that reduces the residual pressure pulsation of the conveyed gas.


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HOFFMAN DEFENDER Lobe Positive Displacement Blower


Our Screw PD blower packages have rotors that turn in opposite directions to maintain precise alignment by means of timing. When the rotors mesh, they form a series of working chambers between the rotors and the casing wall. 

The gas is sucked from the intake side and trapped between the rotors and the casing and the cover. Then, it is transported to the compression side, or discharge, where the working chamber shrinks and the air or gas is compressed. The internal compression leads to a supply of steady, non-pulsating air flow. This minimizes vibration and maintenance; thus, maximizing the PD blower's lifespan. 

HOFFMAN DEFENDER Screw Positive Displacement Blower

Our DEFENDER Screw PD blower has a capacity of up to 6,180 cfm to meet the needs of our customers and their wide range of municipal wastewater treatment applications. 

In wastewater treatment plants, energy consumption accounts for over 50% of annual costs. The DEFENDER Screw blower range meets all cost reduction requirements, allowing customers to save between 15% and 30% on energy consumption when compared with other technologies.


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Superior PD Blower Lobe & Screw Packages

Our HOFFMAN DEFENDER™ PD Blower Lobe and Screw packages are innovatively designed to operate as follows:

  • Efficient thanks to patented rotors, which reduce the number of revolutions and enhance the capacity-pressure ratio
  • Silent as a result of high-efficiency internal compression, silencers, and a noise-reducing enclosure
  • Simple installation and configuration 
  • Flexible to ensure efficient operation 
  • Ease of Maintenance thanks to its simple and robust construction   

The Ideal Solution for Municipal Wastewater

Our team of highly skilled and experienced engineers are focused on developing bowers that offer maximum benefits to our customers. 

H&L WWT Energy Audits

With flexible configurations and enhanced technical features, our HOFFMAN DEFENDER PD blower packages are the perfect solution for a broad range of environmental applications like municipal wastewater treatment including

  • Aeration Process
  • Aerobic Activated Sludge Systems 
  • Backwashing Sand Filtration
  • Desalination
  • Nitrification-Dentrification
  • Primary Sedimentation
  • Sequencing Batch Reactors (SBR)
  • Silent Membrane Systems (MBR)

As the wastewater center of excellence, we have delivered robust, reliable, and efficient solutions for over 150 years.


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Total Peace Of Mind

For over a century, our customers have trusted the quality performance our blowers provide. That is why our blower portfolio remains the most comprehensive offering. 

Equipment is tested before reaching the customer or end-user, ensuring top quality, and avoiding issues or operational downtime. That is why Hoffman & Lamson has a strong reputation as the global leader of engineered solutions, providing premier quality products efficiently and economically. 


Downloads For Positive Displacement Blowers

HOFFMAN DEFENDER Lobe Positive Displacement Blower

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