10 replies to this topic

[bmicky]

Hi,

For a pH control application, we recieved a quotations for the 16" Hastelloy C static mixer. The purpose of the mixer is to mix the 1% diluted sulfuric acid with the
geothermal brine in order to achieve the targeted brine's pH level.
The quotations have been recieved from Sulzer and Chemineer (Kenics).
Sulzer proposed the SMI type static mixer with 2 mixing elements and Chemineer recommended the 4 element HEV mixer.
The both mixers present almost the same characteristics such as a mixing quality, length and a pressure drop.
I would like to ask you, which type of the static mixer would be preferable ?

Thanks, Mike

[ankur2061]

Mike,

As long as the mix viscosity at the outlet of the static mixer is guaranteed and achieved, which here should be well defined and specified, it really doesn't matter what make of static mixer is being used, unless there are certain other considerations such as:
a. First cost (CAPEX)
b. Pressure drop across the static mixer (any limitations on max delta P as specified in datasheet)
c. Layout or installation constraints
d. Requirement of removable mixing elements.

I think you should have a critical look at your static mixer specification/datasheet and perform a 'Technical Bid Analysis' for all the quotes you have received from various vendors. This exercise will help you evaluate which manufacturer/vendor/supplier fits your requirement to the 'Tee'.

Hope this helps.

Regards,
Ankur.

[kalpesh_iitm]

Mr. Ankur Sir,

I have task to design static mixer for washing impurities of methylene dichloride with DI water...
will u suggest me some literature related to this topic so that i can design static mixer?
and what point should be considered while designing static mixer?

thank you...

[ankur2061]

kalpesh,

You don't design a static mixer. You provide the process data for the static mixer to a reputed manufacturer and the manufacturer designs it.

Some process data that you need to provide including the various components that need to be mixed:

Flow rate (total and for individual components), Operating Pressure, Operating temperature, Design Pressure / Temperature, Density / Viscsoity @operating temperature for the components entering the static mixer, mixing efficiency, maximum allowable pressure drop for the static mixer, flow regime - laminar / turbulent, purpose of the static mixer such as dispersion, mixing / blending, heat transfer etc.

There is a blog entry posted by me on static mixers along with an excel attachement at the link provided below:

http://www.cheresour...s-need-to-know/

Hope this helps.

Regards,
Ankur.

Edited by ankur2061, 14 July 2012 - 04:51 AM.

[kalpesh_iitm]

dear Sir,
Thank you for your help. I appreciate your work. It is really helpful.

But in my project I have to calculate length of static mixer and length of pipe required for homogeneous mixing.

So will you please tell where shall i get information abt this.

Thank You..

[ankur2061]

kalpesh,

I have never done the exercise of calculating the static mixer length which essentially means defining the number of mixing elements and their pitch, leaving this exercise for the static mixer manufacturer.

However, you may find some useful information to help you in Section 7.7, Static or motionless mixing equipment, Chapter 7- Mixing in Pipelines in the book "Handbook Of Industrial Mixing Science & Practice"

Regards,
Ankur

[breizh]

http://books.google.... design&f=false

Take a look !
It may help.

note : I've added some technical bulletins from Kenics :
http://www.chemineer.../Literature.php

Breizh

Edited by breizh, 17 July 2012 - 07:44 PM.

[kkala]

Some design data on the subject can be found in the attached "mixers.xls", in addition to data supplied by breizh (post 7).
Taken from book by G Ulrich mentioned there, it is worth while getting it at hand, since it contains more info and references.

Attached Files

•  mixers.xls   27KB   94 downloads

[kalpesh_iitm]

Dear All..

I have managed to calculate required length of static mixer element with all of your help...
Material you provided was really useful..

Thank You everyone for your kind help..

[samsu]

I am working in desalination plant, we are facing problem in the potabilization plant static mixer where we dose ClO2, CO2 & lime water in flow direction.The problem is the huge lumps of lime deposited inside the static mixers caused hinderence in flow.
Provide the possible ways to avoid future failure, is it required to change the dosing points.

[breizh]

Samsu ,

Consider to install a second unit  in // with the existing one and periodically perform the cleaning . 

 

My 2 cents

Breizh