Re: Pneumatic Conveying For Pvc Powder
First system with 175 will work fine. According to my calcs you will have system pressure drop of about 455 mbar and 2655 m3/hr of air this will include 200 m3/hr of RV air leakage. Your calculation is not far off if you take 2655 m3/hr without RV air leakage. Putting up some filter losses and safety factor you are looking you at a 75 kw blower with power absorbed at about 50- 55 kw giving a specific power consumption of 2.5 / 2.75 kw/t. typical for this kind of lean phase system
The velocity range you have selected on the 209 id system is very high. This will increase the power installed to 110 kw & specific power consumption will also go up. If you want a system in 209 id line to run the system at lower pressures you should be looking at a pick up velocity of about 20-22 m/s and not 28 m/s. This will also reduce the total system pressure drop and you might get away with a 90 kw blower. ■
Re: Pneumatic Conveying For Pvc Powder
Dear mantoo
fist of all,thanks for your consideration .
i saw a net-friend's thread,there is a pvc conveying system,which conveying capacity is approx.13t/h,verticle length is 50m.the blower of this system air displacement is 49.3m^3/min£¬pressue is 73.5kPa,but this sytem does not work very well,the current of the motor usually be over the rated current.and the max.pressure can reach to 120kPa.
he change the blower to air displacement is 67m^3/min£¬pressue is 73.5kPa,the system only work well for about a week.
can anyone give your presious viewpoint
BR ■
Re: Pneumatic Conveying For Pvc Powder
What size was the conveying pipe? ■
Re: Pneumatic Conveying For Pvc Powder
Dear Jim Lee,
Attached my calculations of the PVC powder.
Whether our calculations are true for the product you have is uncertain, because we do not have the actual pneumatic conveying properties of the material in question.
Certain is that the chosen velocities are too high
Have a nice day
teus
Attachments
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Teus
Re: Pneumatic Conveying For Pvc Powder
the system diameter that net-frient talked about is DN200
i also know high velocity is to have adverse effect on pvc conveying.more high the conveying velocity,more high the temperature.and the conveying air temperature must be below 45¡æ,because higher temperature make pvc softed,more stickiness,those will made conveying more difficult.
but by testing the two different actual pvc conveying systerms,the velocitys are all about 34m/s.
how to explain this phenomenon.
BR ■
Re: Pneumatic Conveying For Pvc Powder
The difference is between pick up velocities initially the system was running at 13-14 m/s pick up velocity which is too low for this size pipe. Material dose not get fully suspended in he conveying pipe and ultimately chokes the pipe.
The increased flow rate increased the pick up velocity above 18 m/s. which is just about right. Always remember larger pipe size need higher pick up velocity due to pipe wall effect!!
If you want to keep temp of conveying air below 45C you can go for an air blast after cooler or a chiller package installed after the blower. ■
Re: Pneumatic Conveying For Pvc Powder
Dear mantoo
fist thinks for you reply
yes ,the system dose have a cooler device after the blower to cool the high temperature outlet air!i agree with you what you said!
Vinlet of the Fist system=[4*49.3/(3.14*60*0.2^2)]/(1.013+0.735)=15m/s below 18m/s
Vinlet of the Second system=[4*67/(3.14*60*0.2^2)]/(1.013+0.735)=20m/s above 18m/s
but i don't know how to get the value 18,what is the relation between this pick up value with pipeline diameter? does this velocity value is the bulk economic conveying velocity? Is it equal to (2~2.5) times minimum conveying velocity ?
BR ■
Re: Pneumatic Conveying For Pvc Powder
Do not take 18m/s as the magic number it will varry with material properties. Where this number comes from is an acadamic debate and this is not a place for it but some researchers think it is to do with froude number. i am sure some will disagree!!!!! ■
Re: Pneumatic Conveying For Pvc Powder
We will establish a 1:1 scale test laboratory,there will be several pipelines to conveying various materials,including food service industry¡¢chemical industry¡¢metallurgy industry¡¢medical industry etc.It will provide a good platform for pneumatic conveying expert,and Every expert will be welcomed with our open arms.
We can do many tests here like the properties of conveyed material,and make inpact evaluation of those properties,measured economic velocity of various materials.the relation between pipeline (layout,diameter,the value of bend R/D),material(density,repose angle,Carr number,average paricle size ets) and so on.
With testing method of some factor, I think there will many qustions to ask experts here.and we welcome every insterested and seasoned expert come here to guide us or work with us.I give my thanks in advace.
BR ■
Pneumatic conveying for pvc powder
hello everyone
i designed two pneumatic conveying systems for pvc powder ,they have the same pipeline layout:
horizontal length:70m
verticle length:30m
bends number:4 (R/D=10)
pvc bulk density:560kg/m^3
pvc particle density:1400kg/m^3
conveying air temperature must be below 45¡æ
the design results of one system capacity:20t/h is presented below:
pressure drop:55kPa
air displacement:44.25m^3/min
pipeline inner diameter:175
the design results of another system capacity:23t/h is presented below:
pressure drop:35kPa
air displacement:88.28m^3/min
pipeline inner diameter:209
i am not firmly sure the caculation results i made,so can you give me your evaluation about those two system.
BR ■