Roots blower
Tri-lobe Roots blower - from 1.05 to 362.5 m³/min inlet flow at 98 mbar, up to 785 mbar, no oil in the compression chamber, belt drive. For wastewater treatment aeration, pneumatic conveying and agitation.
16 models in the catalogue, flow 1.05 - 363 m³/min, pressure 98 - 785 mbar.
How it works ↓
What is a Roots blower?
Two three-lobe rotors turn without touching inside a casing and push the air from inlet to outlet. The machine is positive displacement: its flow follows its speed and changes little when the back pressure varies. No oil in the chamber; gears and bearings are lubricated separately. Belt-driven, it blows up to 785 mbar.
Made for
- Aeration of wastewater treatment basins and channels
- Pneumatic conveying, agitation, filter backwashing
- A flow that must hold when the water depth or the pressure drop changes
Not made for
- Above 785 mbar, up to 2 barAir-bearing turbo blower
- A compressed air network at 7 bar and aboveOil-free compressor
| Reference | Flow by pressure (m³/min) | Outlet |
|---|---|---|
| CZ-LT-040 | 98 mbar0.6-1.05196 mbar0.57-1.01294 mbar0.54-0.98392 mbar0.51-0.96490 mbar0.49-0.94588 mbar0.48-0.92 | PT1-1/2 |
| CZ-LT-050 | 98 mbar0.99-2.92196 mbar0.79-2.72294 mbar0.64-2.57392 mbar0.5-2.43490 mbar0.38-2.31588 mbar0.29-2.22686 mbar0.21-2.14785 mbar0.15-2.08 | DN50 |
| CZ-LT-065 | 98 mbar2.07-5.17196 mbar1.89-5294 mbar1.71-4.81392 mbar1.55-4.65490 mbar1.41-4.51588 mbar1.29-4.39686 mbar1.19-4.29785 mbar1.09-4.19 | DN65 |
| CZ-LT-080 | 98 mbar3.24-8.64196 mbar2.87-8.27294 mbar2.54-7.94392 mbar2.23-7.63490 mbar1.95-7.35588 mbar1.7-7.1686 mbar1.48-6.88785 mbar1.28-6.68 | DN80 |
| CZ-LT-100 | 98 mbar5.8-13.36196 mbar5.19-12.75294 mbar4.65-12.21392 mbar4.16-11.72490 mbar3.74-11.3588 mbar3.36-10.92686 mbar3.03-10.59785 mbar2.74-10.3 | DN100 |
| CZ-LT-125S | 98 mbar8.13-19.47196 mbar7.43-18.77294 mbar6.8-18.14392 mbar6.22-17.56490 mbar5.72-17.06588 mbar5.25-16.59686 mbar4.83-16.17785 mbar4.46-15.8 | DN125 |
| CZ-LT-125 | 98 mbar10.29-24.66196 mbar9.42-23.78294 mbar8.62-22.98392 mbar7.88-22.25490 mbar7.25-21.61588 mbar6.66-21.02686 mbar6.11-20.48785 mbar5.65-20.01 | DN125 |
| CZ-LT-150 | 98 mbar13.32-31.84196 mbar12.62-31.14294 mbar11.98-30.5392 mbar11.4-29.92490 mbar10.87-29.39588 mbar10.39-28.91686 mbar10-28.52785 mbar9.61-28.13 | DN150 |
| CZ-LT-200 | 98 mbar17.01-51.03196 mbar15.95-49.97294 mbar15.04-49.06392 mbar14.21-48.23490 mbar13.53-47.55588 mbar12.93-46.95686 mbar12.4-46.42785 mbar11.98-46 | DN200 |
| CZ-LT-200A | 98 mbar27.72-79.7196 mbar26.22-78.19294 mbar24.89-76.87392 mbar23.68-75.65490 mbar22.58-74.56588 mbar21.6-73.57686 mbar20.73-72.71785 mbar19.98-71.96 | DN200 |
| CZ-LT-250 | 98 mbar27.72-79.7196 mbar26.22-78.19294 mbar24.89-76.87392 mbar23.68-75.65490 mbar22.58-74.56588 mbar21.6-73.57686 mbar20.73-72.71785 mbar19.98-71.96 | DN250 |
| CZ-LT-250A | 98 mbar39.45-108.3196 mbar37.54-106.3294 mbar35.93-104.7392 mbar34.56-103.4490 mbar33.33-102.1588 mbar32.19-101686 mbar31.19-100785 mbar30.35-99.16 | DN250 |
| CZ-LT-300 | 98 mbar58.94-159196 mbar55.49-155.6294 mbar53.71-153.8392 mbar52.04-152.1490 mbar50.48-150.6588 mbar49.26-149.3686 mbar47.59-147.7785 mbar46.7-146.8 | DN300 |
| CZ-LT-300A | 98 mbar88.3-186.7196 mbar85-183.4294 mbar82.3-180.7392 mbar80-178.4490 mbar78.1-176.5588 mbar76.1-174.5686 mbar74.5-172.9785 mbar72.5-170.9 | DN300 |
| CZ-LT-350 | 98 mbar138.3-291.3196 mbar133.1-286.1294 mbar129-282392 mbar125.2-278.2490 mbar121.9-274.9588 mbar119.1-272.1686 mbar116.3-269.3785 mbar113.5-266.5 | DN350 |
| CZ-LT-400 | 98 mbar236.3-362.5196 mbar230.3-356.5294 mbar225.5-351.6392 mbar221.3-347.4490 mbar217.6-343.7588 mbar214.1-340.3686 mbar211.3-337.5785 mbar208.8-335 | DN400 |
Flows, pressures, noise levels and dimensions recorded model by model on the catalogue sheets.
How it works
The Roots blower is positive displacement: sixteen sizes, from DN40 to DN400, up to 785 mbar, and a flow that follows the speed set by the pulleys. It holds its flow when the water depth or the network pressure drop changes.
Above 785 mbar, and up to 2 bar, or for a very large flow set continuously by speed, the turbo blower takes over.
A Roots blower is a positive displacement machine: two identical rotors turn in opposite directions inside a casing, touching neither each other nor the casing, kept in step by a pair of timing gears. On each turn, the pockets of air trapped between the lobes and the casing travel from the inlet to the outlet, where the network pressure builds up.
Our rotors have three lobes. Compared with the two-lobe profile, the discharge is split into more, smaller pulses, which reduces the pressure surges, hence the noise and the vibration passed on to the bearings. No oil enters the chamber: the gears and bearings are splash-lubricated in separate housings, sealed off from the chamber.
The motor drives the blower through belts and pulleys; the pulley ratio sets the speed, hence the flow. Each sheet gives the inlet flow at each pressure, from 1,000 to 8,000 mmH2O, at the lowest and the highest speed of the catalogue, with the absorbed power.
Aeration of wastewater treatment plants, pneumatic conveying, tank agitation and filter backwashing. Being positive displacement, it keeps its flow when the water depth above the diffusers or the network pressure drop changes, whereas the flow of a centrifugal machine at a given speed falls as the pressure rises.
Three lobes
A smoother discharge than with two lobes, hence less noise and less vibration on the bearings.
No oil in the chamber
The rotors do not touch; gears and bearings are lubricated in separate housings.
From DN40 to DN400
Sixteen sizes, JIS 10K flanges from DN50, up to 8,000 mmH2O (785 mbar); the smallest, threaded, stops at 6,000 mmH2O.
A flow that holds
Positive displacement: the flow follows the speed, and changes little when the back pressure varies.