Also for fly ash? ■

hello teus,

these works good for fly ash, as I do not have data of working installations for PET or PP, I have not tested for them ■

Dear tathadream,

I tried to figure out the pipeline geometry and other conveying parameters s.a airflow etc.

The dense phase installation, is that a 3 pipe diameter pipeline (10” 12” 14”) with a total length of 802 meter?

In the vacuum installation, I found f.i.:

Pick-up velocity = 16 m/sec

Pipe 8” = Area = 3.141593/4 * 0.2^2 = 0.03141 m2

Resulting in a pick-up airflow of:

16 * 0.03141593 = 0.5 m3/sec (# 1060 SCFM)

In cell B66, the Airflow is given as 699 SCFM

In cell B61, the required vacuum = 14.6 “Hg

In cell B72, the required vacuum = 11.2 “Hg

At this moment, I give up.

If you can supply a clear description of the installation, it would be much easier for me to calculate and preferably in SI units.

Have a nice day

Teus ■

Originally Posted by yury.bogdanov

href="showthread.php?p=57450#post57450" rel="nofollow">

Dear tathadream,

I have one question about your spearsheet. The product coefficient of friction how I can calculate for PET or PP?

Now I was calculate my system in your spearsheet and the motor power I have any 7,4kW... can you said me where I have error.

Thanks

Dear Yury,

For PET or PP, you can take a friction factor of 1.35.

Then the power comes as 37.9 kw

Regards

Tathagata

Attachments

dense phase polymer (ZIP)

■

Originally Posted by Teus Tuinenburg

href="showthread.php?p=57449#post57449" rel="nofollow">

Dear tathadream,

I tried to figure out the pipeline geometry and other conveying parameters s.a airflow etc.

The dense phase installation, is that a 3 pipe diameter pipeline (10” 12” 14”) with a total length of 802 meter?

In the vacuum installation, I found f.i.:

Pick-up velocity = 16 m/sec

Pipe 8” = Area = 3.141593/4 * 0.2^2 = 0.03141 m2

Resulting in a pick-up airflow of:

16 * 0.03141593 = 0.5 m3/sec (# 1060 SCFM)

In cell B66, the Airflow is given as 699 SCFM

In cell B61, the required vacuum = 14.6 “Hg

In cell B72, the required vacuum = 11.2 “Hg

At this moment, I give up.

If you can supply a clear description of the installation, it would be much easier for me to calculate and preferably in SI units.

Have a nice day

Teus

Hi Teus,

The air flow is calculated considering pipe diameter, pick up temperature and pick up velocity. Thus it is not so simple.

Regarding the mismatch is pressure drop I have corrected it, the formula somehow got disturbed.

The corrected one is attached

Regards

Tathagata

Attachments

vacuum conveying (ZIP)

■

Dear tathadream,

Have I understood the spreadsheet correctly?

See attachment.

BR

Teus

Attachments

vacuumrecalc (PDF)

■

Yes Teus,

but from your program the capacity is almost half the the capacity which I understand is possible to acheive in actual installations. I think there might be some problems in solid friction factor taken ■

Dear tathadream,

If I calculate solid friction factor of the vacuum system for the double capacity at the same vacuum, I get a negative value.

Conclusion: the 2 calculation algorithms do not match.

All for now

Teus ■

Originally Posted by Teus Tuinenburg

Dear tathadream,

If I calculate solid friction factor of the vacuum system for the double capacity at the same vacuum, I get a negative value.

Conclusion: the 2 calculation algorithms do not match.

All for now

Teus

true enough, but my calculation agrees with the working vacuum conveying plants for fly ash, but for other products it may not be correct ■

Originally Posted by Teus Tuinenburg

Dear tathadream,

If I calculate solid friction factor of the vacuum system for the double capacity at the same vacuum, I get a negative value.

Conclusion: the 2 calculation algorithms do not match.

All for now

Teus

but my calculations agree with the existing fly ash conveying plants, but for other products and is based on those data only, but for other products it might not work, it they are to be used for other products then extensive data from the existing plants for that product is required to calculate the friction factor ■

Originally Posted by tathadream

Dear Yury,

For PET or PP, you can take a friction factor of 1.35.

Then the power comes as 37.9 kw

Regards

Tathagata

The best thing is to put data of existing installations in it and change the friction factor till you achieve the flow rate and pressure drop data for existing systems. Try this for 5-10 existing installations, then you will find the frange within which the friction factor varies and can select suitably from there ■

Helo Yury,

Best option is to put the data for existing systems and find the friction factor for which the existing system matches. ■

Originally Posted by tathadream

Helo Yury,

Best option is to put the data for existing systems and find the friction factor for which the existing system matches.

But this list you can use

ABS/SAN1.9 to 2.1

amor PET1.15 to 1.35

LLDPE no slip2.3 to 2.6

LLDPE with slip1.05 to 1.25

roasted beans1.15 to 1.25

HMLS1.15 to 1.45

nylon1.1 to 1.3

25%glass-filld nylon1.3 to 1.5

PP w/30% PE2.1 to 2.4

LDPE w/28% EVA2.9 to 3.1

HDPE1.1 to 1.3

ground starch(Cargill)0,35

BPA flake(1000FPM).85 to .95

portland cement.3 to .35

LDPE1.5 to 1.7

HDPE1.0 to 1.2

carbon black1.0 - 1.3

fine starch0,35

fly ash (precipitator)0.1 - 0.4

lt. soda ash (115 µm)0.8 - 0.9

soda ash (80 µm)0.3 - 0.5

But use the list as a guide only, best thing is to find the actual friction factor by the method I told, I did the same for fly ash ■