How to Select the Right Capacity Roots Blower for Your Industry?

Roots blowers are essential in industries ranging from wastewater treatment to pneumatic conveying and power generation. However, selecting the right capacity Roots blower—one that matches your specific operational needs—can be a daunting task. Choosing a blower with too little capacity risks underperformance, while an oversized unit wastes energy and increases costs. With over companies trusting Akash Blowers for their industrial solutions, this guide will walk you through the key factors to consider, step-by-step calculations, and practical examples to ensure you pick the perfect blower for your industry.

Understanding Roots Blower Capacity

Roots blower capacity refers to the volume of air or gas it can move per unit of time, typically measured in cubic meters per hour (m³/hr) or cubic feet per minute (CFM). Capacity is influenced by the blower’s size, speed (RPM), and pressure rating (bar or kPa). Selecting the right capacity ensures efficient performance, minimal downtime, and optimal energy use. Whether you’re aerating a wastewater tank or conveying cement powder, the process starts with understanding your application’s demands.

Step 1: Define Your Application Requirements

The first step is to identify what your Roots blower will do. Different industries have unique airflow and pressure needs:

• Wastewater Treatment: Requires consistent airflow for aeration, typically 50– m³/hr at 0.3–0.8 bar.
• Pneumatic Conveying: Needs higher pressure (0.5–1.0 bar) and variable flow (100–10,000 m³/hr) based on material type and distance.
• Power Generation: Demands moderate flow (500– m³/hr) for combustion or biogas circulation, often at 0.2–0.6 bar.
• Aquaculture: Calls for low-pressure aeration (0.1–0.3 bar) with flows of 10–500 m³/hr.

For example, a shrimp farm in Tamil Nadu might need 200 m³/hr at 0.2 bar to oxygenate ponds, while a cement plant in Rajasthan could require m³/hr at 0.8 bar to move powder. Define your application’s flow rate (volume) and pressure (force) to narrow down capacity options.

Step 2: Calculate Required Airflow

To select the right capacity, calculate the exact airflow your process needs. This depends on factors like tank volume, material load, or combustion requirements. Here’s a simplified approach:

• Wastewater Treatment Example: For aeration, airflow is based on oxygen demand. A typical rule is 0.5–1.0 m³/hr per cubic meter of tank volume. For a m³ tank, you’d need 500– m³/hr.
• Pneumatic Conveying Example: Airflow depends on material weight and pipeline length. A rough estimate is 1–2 m³/hr per kg of material conveyed per minute. For 500 kg/min over 50 meters, aim for 500– m³/hr.
• Biogas Application: Flow is tied to gas production rates, often 1–2 times the hourly biogas yield. A m³/day plant (42 m³/hr) might need 42–84 m³/hr.

Use manufacturer data or consult an expert to refine these estimates. Akash Blowers, for instance, offers tailored guidance through their team—more on that later.

Step 3: Determine Pressure Requirements

Pressure is the force needed to push air through your system, measured in bars or kPa. Too little pressure fails to meet demand; too much wastes energy. Assess your system’s resistance:

• Pipe Length and Diameter: Longer, narrower pipes increase pressure needs (e.g., 0.01 bar per 10 meters).
• Elevation: Higher altitudes reduce air density, requiring slight capacity adjustments.
• Backpressure: Filters, diffusers, or material density add resistance (e.g., 0.1–0.3 bar).

For a wastewater plant with 5-meter pipes and diffusers, you might need 0.5 bar total. A conveying system with 100-meter pipes and dense material could demand 0.9 bar. Match this to the blower’s pressure rating.

Step 4: Consider Operating Conditions

Environmental factors affect capacity selection:

• Temperature: High ambient temperatures (e.g., 40°C in summer) reduce air density, requiring a 5–10% capacity buffer.
• Altitude: At meters above sea level, air density drops by ~10%, so increase capacity accordingly.
• Duty Cycle: Continuous operation (24/7) needs durable, higher-capacity units versus intermittent use.

A blower in a hot, high-altitude cement plant might need m³/hr instead of m³/hr to compensate.

Step 5: Choose Between Twin Lobe and Tri-Lobe Designs

Roots blowers come in Twin Lobe (two rotors) and Tri-Lobe (three rotors) configurations, impacting capacity and efficiency:

• Twin Lobe: Higher capacity (up to 10,000 m³/hr), simpler design, but noisier and less efficient at high pressures.
• Tri-Lobe: Lower noise, better efficiency, and smoother airflow, ideal for 50– m³/hr ranges.

A food processing unit might prefer a Tri-Lobe for quiet operation, while a heavy-duty conveying system opts for Twin Lobe capacity. Akash Blowers offers both, customizable to your needs.

Step 6: Factor in Energy Efficiency

Energy costs can account for 60–80% of a blower’s lifetime expense. Select a capacity that balances performance with efficiency:

• Variable Frequency Drives (VFDs): Adjust speed to match demand, saving 20–30% on power.
• Motor Size: A 15 kW motor might suffice for m³/hr, while 50 kW handles m³/hr.
• Sizing: Oversized blowers waste energy (e.g., a m³/hr unit for a m³/hr need uses 50% excess power).

A wastewater plant choosing a m³/hr blower with VFD over a m³/hr fixed-speed unit could save thousands annually. Step 7: Consult Manufacturer Data and Experts Manufacturers provide performance curves and tables linking capacity, pressure, and power. For example, Akash Blowers’ Tri-Lobe models range from 5– m³/hr at 0.1–1.0 bar. Their website, Akash Blowers, offers detailed specs and expert consultation to match your needs. Shri Ram Industries, a Gujarat wastewater client, used Akash’s guidance to select a m³/hr blower, cutting energy costs by 40%. Practical Example: Selecting a Blower Imagine a biogas plant producing m³/day (83 m³/hr) of methane, needing circulation at 0.4 bar:

1. Airflow: Double the gas rate for efficiency = 166 m³/hr.
2. Pressure: 0.4 bar plus 0.1 bar for piping = 0.5 bar.
3. Conditions: 35°C ambient temperature adds a 5% buffer = 175 m³/hr.
4. Design: Tri-Lobe for efficiency.
5. Result: A 200 m³/hr, 0.5 bar blower with a 7.5 kW motor fits perfectly.

Capacity Selection Table Industry Flow Range (m³/hr) Pressure (bar) Typical Motor (kW) Recommended Type Wastewater Treatment 50– 0.3–0.8 5–75 Tri-Lobe Pneumatic Conveying 100–10,000 0.5–1.0 15–150 Twin Lobe Power Generation 500– 0.2–0.6 10–50 Tri-Lobe Aquaculture 10–500 0.1–0.3 1–15 Tri-Lobe Chemical Processing 200– 0.4–0.9 10–100 Twin/Tri-Lobe

Why Trust Akash Blowers?

With over 15 years of experience, Akash Blowers has helped + companies select the right capacity. Their ISO-certified blowers, rapid delivery (24-48 hours), and PAN-India service (24-72 hours) ensure you’re supported every step of the way. Visit Akash Blowers to explore their range and get personalized advice. Conclusion Selecting the right capacity Roots blower involves understanding your application, calculating airflow and pressure, and factoring in efficiency and conditions. Whether it’s a 50 m³/hr unit for aquaculture or a m³/hr beast for conveying, the right choice boosts performance and cuts costs. For expert help and reliable options, check out Akash Blowers—your partner in powering industry success.

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A thorough analysis of your installation and application is key to selecting the right technology, and there will undoubtedly be one or more aspects might take precedence over others. For example, a smaller space for the blower might dictate choosing a technology with a smaller footprint and lower noise levels, while an application that requires lower energy costs may be best suited for an energy-efficient technology that has a higher initial cost. Key factors that should be taken into consideration include:

A correctly sized blower installation will help to achieve a more energy-efficient process. For instance, in a situation where compressor turndown is employed as the low-pressure source, replacing the compressor with an air blower to deliver 0.3 and 1.5 bar(g) air will result in significant savings. For every 1 bar(g) the air is compressed above the actual demand, 7% of energy is wasted.

Site conditions have a bearing on blower choice. For example, dusty environment or hot humid site for a blower installation might dictate the choice of a technology offering a reliable positive displacement screw, lobe blower or multi stage centrifugal to provide a reliable source of low pressure air with no much of sensitivity to dust or high ambient temperatures. On the other hand, the application criterion of lower energy costs may be best met by a more energy-efficient technology that comes with a higher capital cost.

Are you interested in learning more about Roots Blower Supplier? Contact us today to secure an expert consultation!

The cheapest solution to purchase does not automatically result in the lowest operating costs. It is therefore advisable not only to consider the investment costs in the design phase, but also to keep an eye on the necessary expenses over the entire life cycle of the machines to get the maximum ROI.

When it comes to routine maintenance and service support, some older blower technologies may require units to be serviced, repaired or re-furbished offsite. Advanced design developments in the latest oil-free, low-pressure blowers now sees the inclusion of low maintenance components, extended on-site service intervals, each blower technology need to have routine services and checkups , however the each technology design and mechanism differs on the number of consumables and service periods  and the benefits of lifetime customer support plans.

It pays to check the vital statistics. As an example, the tri-lobe rotors incorporated into the latest generation of low-noise, low-vibration, low-pulsation blowers are capable of sweeping nearly six times the volume of air in a single revolution compared to their belt-driven, twin-lobe predecessors. On average, this older technology experiences 5% - 7% more transmission losses.  

An important advantage of the direct-drive, oil-free, rotary screw blowers is wide turndown, especially on models with integrated inverter drives. This allows the units to match the airflows to the daily and seasonal variations in the effluent inflow, resulting in additional energy savings. In order to cope with fluctuations in air demand, screw blower technology can operate from 100% capacity to 25% with very little change in specific power requirement.

There are multiple compression technologies that are used for generating low pressure air. The three main technologies that are popular today are lobe, screw and centrifugal; and within the centrifugal technology there is multistage, high speed turbo or integrally geared centrifugal blowers. So, this takes us to five types of blower technologies that are used extensively within the low pressure market.

Each technology has its own space like lobe typically is the best when it comes to pressure below 0.3 barg and flow less than 500 m3/hr, while screw works better at higher pressure and flow between 500-5,000 m3/hr and then centrifugal technology takes over for larger volumes.

However, the decision on a compression technology is steered by energy efficiency which is also linked to the specific application of low pressure air.

Atlas Copco is one of the very few global manufacturer that has expertise in all the technologies and could offer the most suitable and reliable system that can deliver the best energy efficiency of a low pressure compressed air installation by combining different compression technologies available to handle the compressed air demand.

Whatever your low-pressure needs, the ultimate aim is for a blower system that provides total reliability, guaranteed continuity of process operations, and combines optimum performance with protection of the process, the environment and operational energy costs. We recommend reaching out to an established low-pressure expert who understands your application’s unique needs and provide you with guidance about the best-fitting technologies. Contact our expert today to get more product information!

Contact us to discuss your requirements of Buy Roots Blower. Our experienced sales team can help you identify the options that best suit your needs.