3 replies to this topic

[P.R.Naren]

Design of cyclone separators

I wish to design a cyclone separator for a cold flow laboratory riser setup for specifications given as follows

Superficial gas velocity 10m/s
Solid circulation flux 100 to 400 kg/m2s
Particle density 1500 - 2500 kg/m3
particle mean size range 70 to 200 microns

Can anyone suggest me how to go about with cyclone design for an riser setup, which will be operating in fast fluidized mode. The problem is face is there is lot of literature available concerning cyclone design - like stairmaid design etc but all these designs are based on experiments done with air only and/or are valid for low particle loading. But in case of risers, at high solid flux operating conditions, particle loading will be around 30.
So I would like to know is there any specific design procedures for such high mass loading typical of high solid flux risers.

[siretb]

THis does not seem a very difficult problem. Your particle size is large. You may use any approach of the litterature, and the data you provide does not enable a design, because the actual flow is missing. Keep in mind that the cut size (d50) of a cyclone is proportional to the square root of the diameter. And the diameter is linked to the flow.For a Laboratory design a single unit is likely to be enough

As for the influence of the particle loading, increasing the dust concentration if beneficial. You will find correction factors in Hoffmann and Stein's book (gas cyclones and swirl tubes, principles, design & operation, Springer.
I have an empirical relation (Svarovskyi 1981)
Eff(c2)=1-(1-eff(c1))*(c1/c2)**0.18 where c1 and C2 are two concentrations. If you do not want to use more complicated approach, I would suggest you do a design using the method you have available, using a concentration of 1g/m3 and use the above correction factor. Again, since your separation is easy, I would not care much and would just overdesign a bit.

If you need further help please supply the actual gas flowrate, solids loading and required efficiency.
I hope this will help

[P.R.Naren]

Thank you 'siretb' for ur reply

My problem is that i have to setup a circulating fluidized bed setup in our laboratory, which i can operate over the range as given below

superficial gas velocity: 5 - 10m/s
Solid circulation flux: 50 - 400 kg/m2s
Particle density: Two types of particles to be studied 1500 kg/m3 and 2500 kg/m3
Particle size: again two size range are to be used: mean do of 75 microns , 150 microns

Now the riser idameter that we have is of 5cm, means

taking 10m/s and 300kg/m2s solid flux as basis
we get
air flow rate to be 0.019 m3/s
particle laoding to be: 25kg/kg of air == 30 kg/m3 of air
efficiency required for cyclone = 80%
No of cyclones : 2 can be used in series

Now whether to follow standard stairmaid cyclone design procedures for sizing these cyclone ?? or how far is that employing the correction factor as you have specified will hold good at high particle holding??

Design of cyclone separators

I wish to design a cyclone separator for a cold flow laboratory riser setup for specifications given as follows

Superficial gas velocity 10m/s
Solid circulation flux 100 to 400 kg/m2s
Particle density 1500 - 2500 kg/m3
particle mean size range 70 to 200 microns

Can anyone suggest me how to go about with cyclone design for an riser setup, which will be operating in fast fluidized mode. The problem is face is there is lot of literature available concerning cyclone design - like stairmaid design etc but all these designs are based on experiments done with air only and/or are valid for low particle loading. But in case of risers, at high solid flux operating conditions, particle loading will be around 30.
So I would like to know is there any specific design procedures for such high mass loading typical of high solid flux risers.

hello naren,
plz let me know how to desing cyclone separator for small size partical with 40 micron size and other specification may vary