Wastewater Aeration Blowers & Process Air Solutions
The 60 Percent Problem Plant Facility’s Energy Bill Is Too High
Aeration is the single most expensive process in your plant. It typically accounts for 50 percent to 70 percent of your total electrical consumption.
Most plants are burning cash because they are running the wrong machine for the wrong curve. We see it constantly.
- The SBR Problem Using a centrifugal blower that surges every time the water level drops
- The DO Hunting Problem Turbo blowers with control gaps that constantly cycle on and off, trying to hit a Dissolved Oxygen setpoint they cannot reach
- The Heat Problem Air cooled motors that lose efficiency and lifespan the moment the ambient temperature hits 95°F
The Solution Knape Associates engineers Independent Blower Packages. We are not tied to a single factory catalog. We mix and match the best bare shaft air ends, whether Turbo, Screw, or Multistage, to build a system that matches your specific hydraulic profile.
Have questions? Not sure what you need? Call us & speak with an engineer today.
Choosing the Right Technology
We categorize technology by physics, not by brand. Here is how we select the right machine for your retrofit or new build.
1 High Speed Turbo Packages The Base Load Workhorse
Best For Municipal Plants (greater than 5 MGD), 24/7 base load.
The Tootsie Pop Warning Not all Turbos are equal. Many low cost options use Air Foil Bearings. These rely on a cushion of air to float the shaft. The problem? Every time the blower starts or stops, the shaft drags on the bearing until lift is achieved. It is like the old Tootsie Pop commercial asking how many licks until you get to the center. Eventually, the friction welds the shaft to the housing.
Our Approach We specify Magnetic Bearing Turbo packages. The shaft is levitated before it spins, meaning unlimited starts and stops with zero wear. We integrate these with Liquid Cooled VFDs to maintain tighter motor tolerances and higher efficiency, even on the hottest days of the year.
2 Rotary Screw Blower Skids The Deep Tank Specialist
Best For Deep tanks (greater than 20 ft), SBRs, high pressure applications.
The Squeeze Advantage Standard Lobe blowers use external compression and simply push air against the backpressure of the tank. It is inefficient. Rotary Screw Blowers use internal compression. They squeeze the air between the rotors before it leaves the machine. As we like to say The more you squeeze, the more you save.
- At 7 PSI a Screw Blower saves approximately 20 percent energy over a Lobe
- At 11 PSI deep tanks a Screw Blower saves 50 percent energy
3 The Hybrid Retrofit Strategy
Best For Plants needing efficiency without a total rebuild.
You do not have to remove every blower in your building. The smartest ROI often comes from a Blended System.
- The Base Keep your existing Multistage Centrifugal blowers to handle the steady 24/7 base load. They are reliable and efficient at their design point
- The Trim Retrofit a single Rotary Screw or Turbo unit to handle the diurnal swings
This gives you the reliability of big iron with the precision of modern VFD control, often for half the capital cost of a total replacement.
Air and Gas Applications for Water & Wastewater Treatment
Comprehensive blower solutions for municipal and industrial water treatment processes requiring precise air flow control and energy efficiency.
| Application | Purpose |
|---|---|
| Basin Aeration | Provides oxygen for biological treatment processes |
| Air Scouring | Cleans filter media and prevents clogging |
| Grit Chamber Aeration | Separates organic matter from inorganic grit |
| SBR Systems | Sequential batch reactor oxygen supply |
| MBR Systems | Membrane bioreactor aeration and scouring |
| Lagoon Aeration | Large-scale pond and lagoon treatment |
| Gas Boosters | Anaerobic digester gas circulation and mixing |
What causes rotten egg smell in wastewater treatment and how do blowers help control odors?
What causes rotten egg smell in wastewater treatment and how do blowers help control odors? The rotten egg smell comes from hydrogen sulfide gas produced when oxygen levels drop in aeration tanks, creating anaerobic conditions. Blowers control odors by maintaining proper aeration to prevent anaerobic conditions and by delivering air to scrubbers that neutralize odorous compounds.
Blower Fan Manufactures
Reliability Case Study Lessons from the Texas Heat
Knape Associates is based in the Gulf Coast, where ambient mechanical room temperatures routinely exceed 110°F. This is our proving ground.
If you install an air cooled motor here, you have to de rate it, meaning you lose efficiency just to keep it from overheating. This is why we prioritize Liquid Cooled Motors and External Control Enclosures for our packages.
The National Takeaway If our systems can hold tight tolerances and peak efficiency in a Houston summer, they will deliver decades of reliability in a Pennsylvania winter or an Arizona drought. We engineer for the extreme so you can run in the green.
Blower Selection Guide
| Application | Pressure Challenge | Recommended Tech | Why |
|---|---|---|---|
| Deep Tank Aeration | High (greater than 10 PSI) | Rotary Screw | Internal compression handles high pressure efficiently |
| SBR or Variable Level | Fluctuating | Positive Displacement | Delivers constant volume regardless of pressure swings |
| Base Load Aeration | Constant | Mag Bearing Turbo | Highest wire to air efficiency for continuous operation |
| Digester Gas | Hazardous | Northern Blower | Gas tight construction for safe methane handling |
Need custom blowers?
Contact us now for a fast quote on the right model for your specific application. Just let us know the application and we can help!
Stop Guessing Your System Curve
Most plants operate on safety factors stacked on top of old data. You are likely over aerating and overspending.
We do not offer generic audits. We offer a Capital Equipment Assessment. We analyze your piping head loss, measure your actual discharge pressure, and model a Retrofit Strategy that pays for itself in energy savings.
FAQ
What's the difference between wastewater treatment aeration blowers and standard industrial blowers?
Wastewater treatment aeration blowers are specifically designed for continuous 24/7 operation in corrosive environments with hydrogen sulfide and high moisture. They feature corrosion-resistant materials like stainless steel 316L or specialized coatings, oil-free operation to prevent biological contamination, and precise pressure control for dissolved oxygen requirements. Standard industrial blowers typically fail within 6-18 months in wastewater environments, while properly specified wastewater blowers operate reliably for 15-20 years.
How much pressure do air blowers for wastewater treatment need?
Pressure requirements vary by application: activated sludge systems typically operate at 7-8 psig, while membrane bioreactor systems require 0.3-10.0 psi depending on membrane type (hollow fiber, flat plate, or tubular). Fine bubble diffuser systems need higher pressures due to depth and orifice size requirements. Proper sizing includes a 50% safety factor above calculated oxygen requirements to handle peak biological loads and system variations.
What size aeration blower does my wastewater treatment plant need?
Blower sizing depends on biological oxygen demand, treatment process type, and system turndown requirements. Most systems need minimum 80% turndown capability to handle diurnal flow variations. Individual blowers should provide 40-60% turndown (2:1 ratio), with N+1 redundancy minimum for reliability. Sizing calculations must account for alpha factors (0.4-0.55 for fine bubble diffusers), oxygen transfer efficiency, and future capacity needs.
How much energy do wastewater treatment blowers consume?
Aeration blowers consume 55-60% of total plant electrical load in conventional activated sludge systems, and 70-80% in membrane bioreactor systems due to additional membrane scouring requirements. Modern centrifugal blowers achieve 70-80% efficiency, while older equipment may operate at significantly lower efficiency. Variable frequency drives can reduce energy consumption by 10-40%, with payback periods typically 2-5 years.
When should regenerative blowers be used for wastewater treatment plants?
Regenerative blowers work best for smaller wastewater treatment facilities (0.1-5 MGD), package plants, and applications requiring oil-free operation to prevent biological contamination. They offer compact design ideal for retrofit installations, simplified maintenance with fewer mechanical components, and reliable performance for sequential batch reactors. However, they’re limited to lower flow applications compared to centrifugal blowers used in large municipal facilities.