Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Related Articles


Blowers for Aerobic tank

Blowers for Aerobic tank

Blowers for Aerobic tank

In an integrated ETP facility ( refinery+ petchem), for an aerobic tank, the contractor is suggesting to go for a Tri-lobe blower ( capacity around 2200 Nm3/hr with a discharge pressure of around 0.7barg. The temperature at the discharge of the blower is said to be around 125 deg C.

Is it ok to go for a Tri-lobe blower for such a huge capacity? i understand from various articles that above 450 Nm3/hr , centrifugal type blowers are preferable. Also will there be such a huge temperature rise across the blower having the suction temperature of around 35 deg C? Will this hot air will have any problem while it is diffused inside the aerobic tank or the diffuser pipe ( CPVC) or the diffusers ( EPDM)?

Thanks to advise

RE: Blowers for Aerobic tank


There are plenty of trilobes on the market for that size and larger. The "recommendation" regarding the centrifugal goes more the other way in that you probably would not choose(perhaps not even be able to buy) one below 450Nm3/hr. You have not really provided enough information to know which is best but each type has its pros and cons.

To have an operating temperature that high means that the specifier must have the blower running very fast to do the duty with a lot of internal compression. If i was doing it i would specify a larger blower and run it a little a little easier. The heat is a concern for downstream equipment but more so for the blower itself and the equipment around it such as motors , belt drives , acoustic covers etc.

"Any water can be made potable if you filter it through enough money"

RE: Blowers for Aerobic tank

Thank you very much ashtree. I thought i have provided all the information. My query was that for a capacity of 2200 Nm3/hr whether we can go for Centrifugal blower or we need to choose only Positive disp blower? Yes you are right that higher temperatures will have serious implications on its downstream equipment and also for the blower, motor drive belt etc.

Please do ask me what other additional information is required from me on the above subject and i will provide.

Thanks once again for your valuable information.

RE: Blowers for Aerobic tank

There is a newer rotary model out called a rotary screw. The rotary screw blowers use less energy than conventional rotary blowers and even achieve significant energy savings compared to currently available screw blowers. Plus the rotary screw blowers are quieter.


The downstream components are generally under water and will not be affected by heat.

The downside of centrifugal blowers is that the turndown is limited and complicated.

RE: Blowers for Aerobic tank


To decide if a PD blower is required or whether or not a centrifugal blower could do the job here are a couple of things that need to be determined:

1) Does the level of the aerobic tank vary much when it is being aerated. For example is the tank decanted at times or is it the same level all the time?
2) How much turn down or control of air volumes do you require and what controls this?
3) Is noise an issue?

"Any water can be made potable if you filter it through enough money"

RE: Blowers for Aerobic tank


I am collecting the informations from Operations team. I will get back with the details shortly

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close