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Air Blower Manufacturer & Supplier from China
Air Blower Manufacturer & Supplier from China
Roots Blowers & Roots Vacuum Pumps
A roots blower is a roots-type positive-displacement blower — a machine that uses interlocking three-lobe rotors to move a fixed volume of air with every revolution. Unlike centrifugal fans, roots rotary lobe blowers deliver steady airflow even when discharge pressure changes. Flip the plumbing around, and the same rotor platform becomes a roots vacuum pump — pulling oil-free vacuum instead of pushing pressurized air. That makes roots technology the standard choice for wastewater aeration, pneumatic conveying, vacuum packaging, and any process where airflow or vacuum reliability is non-negotiable.
Generation 2 Classic Longtech Roots Blower
Classic Three-Lobe Roots Blower (SL) — our cost-first positive-displacement blower for pressure duty (aeration, combustion air, conveying). Same proven tri-lobe build as the SLV, but it pushes air out at positive pressure. No VFD, so lower upfront cost than the LC series, but higher running power.
Classic Three-Lobe Roots Vacuum Pump (SLV) — the SL's suction twin. Same rugged tri-lobe platform, but it pulls a vacuum (negative pressure) for packaging, holding, and extraction. Like the SL, it runs on a standard motor without VFD: the budget pick, not the energy-saving LC option.
Energy-Saving Roots Blower & Roots Vacuum Pump (LC) — the upgraded, efficient sibling of the SL/SLV range. A PMSM motor + VFD cuts power 30–65%, and one dual-mode host works as either blower or vacuum pump. Pick it when power cost and flexible duty beat the lowest price.
Energy-saving roots blower and roots vacuum pump share the same platform, much lower noise, help to save 30-65% electricity comsumption. Highly Recommended from Slovdson!
SL series three-lobe roots blower: 0.15–362 m³/min airflow, up to 8000 mmAq. CNC-machined rotors, ISO 9001, 12 models for wastewater…
Table of Contents
Slovdson Roots Type Blowers & Vacuum Pumps
Slovdson is a reliable roots blower manufacturer in China, mainly supplying four product lines of roots blowers and roots vacuum pumps at our ISO 9001-certified factory in Ganzhou, Jiangxi — both classic Longtech roots blowers and energy-saving roots blower vacuum pumps on the same rotor platform:
Series
Type
Drive
Best For
SL Series
Pressure Blower
Fixed-speed induction motor
Standard aeration, conveying, combustion air
SLV Series
Vacuum Pump
Fixed-speed induction motor
Standard vacuum conveying, packaging, tissue
LC Series (Pressure)
Energy-Saving Pressure Blower
PMSM motor + VFD
24/7 aeration — 30–65% energy savings
LC Series (Vacuum)
Energy-Saving Roots Vacuum Pump
PMSM motor + VFD
24/7 vacuum — 30–65% energy savings
All four share the same three-lobe rotor geometry, splash-lubricated gearcase, and oil-free gas path. The LC series adds a permanent magnet synchronous motor (PMSM) and variable frequency drive (VFD) that matches motor speed to actual demand — cutting electricity consumption by 30 to 65 percent.
Not sure which one you need? Start here.
SL Series — Three-Lobe Roots Blower (Pressure)
The SL Series Longtech roots blower is a three-lobe roots blower; it is the conventional roots blower built for continuous industrial duty. It delivers pressurized air at 1000–8000 mmAq — the pressure range that covers almost every aeration, conveying, and combustion air application.
Classic Roots Rotary Lobe Blower
Specifications
Parameters
Flow range
0.15–362 m³/min
Pressure range
1000–8000 mmAq
Models
SL-040 through SL-400 (12 frame sizes)
Rotor type
Three-lobe, CNC-machined matched pairs
Materials
FC250 cast iron casing, SCM415 alloy steel gears, SUJ2 bearings
Discharge
100% oil-free — gas path isolated from lubrication system by labyrinth seals
Lubrication
Wet-sump splash — no external oil pump, no cooling water required
The SLV Series is the other Longtech roots blower, which is the vacuum-configured version of the same three-lobe rotor platform. Instead of pushing air out the discharge port, it pulls air in through the inlet port — creating oil-free vacuum down to −5000 mmAq. Same castings, same gears, same bearings as the SL. Same spare parts.
Classic Roots Vacuum Pump
Specifications
Parameters
Suction flow range
0.15–362 m³/min (at inlet conditions)
Vacuum range
Up to −5000 mmAq
Models
SLV-040 through SLV-400 (12 frame sizes)
Rotor type
Three-lobe, CNC-machined — identical to SL pressure series
Gas path
100% oil-free — labyrinth-sealed, no contamination
LC Series — Energy-Saving Industrial Roots Blower (Pressure)
The LC Series pressure blower takes the proven SL three-lobe rotor platform. It replaces the fixed-speed induction motor with a permanent magnet synchronous motor (PMSM) driven by a tuned variable frequency drive (VFD). The rotors, gearcase, and oil-free gas path stay the same. What changes is how the machine consumes electricity. It is the newly developed high-efficiency roots blower.
Variable frequency drive (VFD) — soft start, demand-matched speed
Energy savings
30–65% vs. conventional fixed-speed roots blower
Models
5 frame sizes — LC-080 through LC-250
Rotor type
Three-lobe, CNC-machined matched pairs — same platform as SL
Transmission
Belt drive + dual gearbox, 18-year design life
Discharge
100% oil-free — labyrinth-sealed gas path
Noise
4-chamber resonant silencer with acoustic insulation
Why it saves energy: A fixed-speed roots blower draws near-full current regardless of actual demand — at 3 AM when the aeration basin needs half the airflow, the motor still pulls roughly full power. The LC's VFD matches motor speed to real-time demand. This enables the energy-saving roots blower to draw ~50% of the power at 50% load. For plants running multiple blowers around the clock, the payback on the upfront price difference is typically 18 to 30 months. Everything after that is margin.
Top applications:
🏭 Municipal & industrial wastewater — MBR systems, activated sludge aeration, 24/7 operation with variable load
🐟 Large-scale aquaculture — RAS, biofloc systems where electricity is the #1 operating cost
🏗️ Cement & power — combustion air, material fluidization with fluctuating demand
The LC Series energy-saving roots vacuum pump is the vacuum-configured version of the LC energy-saving blower platform — same PMSM motor, same VFD drive, same dual-gearbox host, configured for vacuum duty. It delivers oil-free vacuum with the same 30–65% energy reduction as the LC pressure blower.
Energy Saving Roots Blower Vacuum Pump
Specifications
Parameters
Power range
15–45 kW
Motor type
Permanent magnet synchronous motor (PMSM) — same as LC pressure
Drive
Variable frequency drive (VFD) — vacuum-specific drive curves, soft start
Energy savings
30–65% vs. conventional fixed-speed roots vacuum pump
Models
5 frame sizes — LCV-080 through LCV-250
Rotor type
Three-lobe, CNC-machined matched pairs — same platform as SL/SLV
Transmission
Belt drive + dual gearbox, 18-year design life
Gas path
100% oil-free — labyrinth-sealed, no contamination
Noise
4-chamber resonant silencer with acoustic insulation
Spare parts
Interchangeable with LC pressure series of same frame size
💡 One machine, two jobs. If your process needs both pressure and vacuum at different stages, the same platform handles both — and your spare parts inventory covers both sides.
Classic vs Energy-Saving: Which Drive System?
Specifications
SL / SLV (Classic)
LC Series (Energy-Saving)
Motor
Fixed-speed induction motor
PMSM — permanent magnet synchronous motor
Speed control
Single speed — always runs at full output
VFD — variable frequency drive, demand-matched
Energy at 50% load
~90–95% of full power
~50% of full power
Energy savings
Baseline
30–65% vs. classic
Upfront cost
Lower
Higher — payback in 18–30 months
Best when
Intermittent use, stable load, budget-constrained
24/7 operation, variable load, high electricity rates
💡 The rule of thumb: If your blower runs more than 3,000 hours per year with variable load, the LC series usually pays for itself within 2–3 years through electricity savings alone. If it runs intermittently or at steady full load, the SL series is the more cost-effective choice.
Roots Blower Vacuum Pump Applications
Roots blowers and roots vacuum pumps earn their keep in environments where airflow or vacuum has to be steady, oil-free, and reliable enough to run 24/7 for years.
Application
Typical Blower
Why Roots
Wastewater aeration
SL-080 to SL-300 / LC-100 to LC-250
Steady airflow as diffusers age and back-pressure shifts; LC cuts energy 30–65%
Aquaculture pond aeration
SL-040 to SL-100 / LC-080 to LC-125
Oil-free air — oil mist kills fish and disrupts biofilters
Pneumatic pressure conveying
SL-100 to SL-300
Constant volume delivery handles fluctuating material loads
Pneumatic vacuum conveying
SLV-080 to SLV-250 / LCV-100 to LCV-200
Leaks pull air in rather than blowing product out; VFD matches variable throughput
Vacuum packaging
SLV-050 to SLV-125 / LCV-080 to LCV-150
Oil-free vacuum — no contamination of food-contact surfaces
Tissue paper converting
SLV-040 to SLV-100 / LCV-080 to LCV-125
Steady vacuum — fluctuation means misfed sheets and line stops
Cement & power plants
SL-200 to SL-400 / LC-200 to LC-250
Large-flow air supply for material handling and combustion
How to Choose the Right Roots Air Blower?
Step 0: Classic or energy-saving? If your air blower runs 24/7 with variable load (typical for wastewater aeration), the LC series pays back the upfront difference in 18–30 months through electricity savings. If it runs intermittently or at steady full load, go with the classic SL/SLV series. See the Classic vs Energy-Saving comparison above.
Step 1: Decide pressure or vacuum. Are you pushing air into something (→ SL or LC pressure series) or pulling air out of something (→ SLV or LCV vacuum series)?
Step 2: Determine your flow and pressure/vacuum. How many m³/min? At what back-pressure or vacuum level? If you're unsure, our default recommendation is 10–20% headroom above your calculated requirement.
Step 3: Check site conditions. Temperature, altitude, and humidity shift performance. Our STP-based tables assume 20°C at sea level. If your site differs significantly, our engineers do the conversion for you.
Step 4: Pick your accessories. Bare blower, or a packaged system on a common baseplate with pre-installed silencers, valves, and flexible joints? If you want to set it down, bolt it, and wire it — ask about the package.
Why Slovdson for Roots Blowers & Roots Vacuum Pumps
Manufacturer-direct, not a trading company. Our factory in Ganzhou, Jiangxi, handles casting, machining, assembly, and testing under one roof. You're buying from the source.
ISO 9001 certified—same processes, same quality, every machine — classic SL or energy-saving LC.
4 product lines, 0.15–362 m³/min. One supplier covers your full roots blower and roots vacuum pump range — classic fixed-speed and energy-saving VFD, pressure and vacuum. No need to qualify multiple vendors.
English-speaking engineers. They size blowers, read P&IDs, calculate ROI for energy-saving upgrades, and flag issues before you order. Not just order-takers.
Spare parts ship within 48 hours. Bearings, seals, gaskets, filters — stocked and ready. SL and SLV share parts; LC pressure and LC vacuum share parts.
OEM and private labeling available. Your brand, our hardware.
Frequently Asked Questions
What is a roots-type blower?
A roots-type blower is a positive-displacement rotary lobe blower that uses interlocking lobed rotors to move a fixed volume of air per revolution. Flow stays nearly constant as discharge pressure changes — unlike centrifugal fans. The design was invented by Philander and Francis Roots in the 1850s and remains the standard for industrial aeration and conveying applications.
What's the difference between SL (pressure) and SLV (vacuum)?
Mechanically, they're identical — same rotors, gears, bearings, and oil system. The difference is which port you connect to your process. Connect the discharge port → pressure blower (SL). Connect the inlet port → vacuum pump (SLV). Spare parts are interchangeable between the two series.
Two-lobe or three-lobe — which should I choose?
Three-lobe is the current industry standard. It produces 6 air pulses per revolution (vs. 4 for twin-lobe roots blowers), resulting in smoother discharge flow, lower vibration, and 3–5 dB(A) less noise. Two-lobe designs are still available for legacy replacement but are not recommended for new installations.
What does the LC energy-saving series actually save?
The LC series replaces the fixed-speed induction motor with a PMSM motor and VFD that matches motor speed to your actual demand. At 50% load, it draws ~50% of the power — while a conventional blower still draws ~90–95%. Result: 30–65% less electricity. For a wastewater plant running multiple blowers 24/7, the payback on the upfront price difference is typically 18–30 months. After that, it's pure savings.
Can I retrofit my existing SL/SLV blower with a VFD?
Not as a field conversion — the LC series uses a purpose-built PMSM motor, dual gearbox, and tuned VFD with blower-specific drive curves that are engineered into the machine at the factory. However, if you're replacing an aging blower or adding capacity, upgrading to LC for your next unit is straightforward.
How much does a roots blower cost?
Roots blower price depends on frame size, operating pressure/vacuum, motor specification, and accessory package. A small aquaculture unit (SL-040/SL-050) is at the entry level; a fully accessorized LC-250 for municipal wastewater is a capital equipment investment. LC series carries a higher upfront cost than the SL but recovers it through energy savings. We quote within one working day — send your flow, pressure, and power supply for an exact price.
Can a roots blower run 24/7?
Yes. The wet-sump splash lubrication system has no external oil pump to fail, rotors never touch (no wear in the gas path), and bearings are sized for 40,000+ hours L10 life. Many of our units have been running continuously in wastewater plants since 2019 with only scheduled oil changes. The LC series is specifically designed for 24/7 variable-load operation.
Do you ship to my country?
We ship to wastewater plants, aquaculture operations, and industrial facilities across Asia, Africa, the Middle East, and South America. Contact us with your location, and we'll confirm shipping options and lead time.
Have a question? Choose or customise an air blower for yourself. Customer support is here for you!
Whether you have a question about our products, want to schedule a demo, or need more information about our air blowers, please let us know your requirements for airflow, pressure, and specific applications below!
