It is unlikely that you will be able to convey 8 tonne/h through such a pipeline with a vacuum conveying system. You will need a pressure drop of about one bar with a 50 mm bore pipeline.

You are also using far too much air. Solids loading ratios of well over 200 are possible with barite in such a short pipeline, if you use a positive pressure conveying system.

It should be possible with exactly the same amount of air in an 80 mm bore pipeline with a vacuum conveying system. ■

dear kevinjcg

Baryte (BaSO4) has a material density of 4500 kg/m3

Compared to cement this gives a suspension velocity of approx. 1,25 m/sec

I figured a suction pipeline of 10m vertical and 20m horizontal.

A initial pressure drop at the intake of 1500 mmWC

This resulted in the following table (capacity in tons/hr = function (vacuum in bar))

kevinjcg bar s 11-07-2005

Vacuum discharge of Baryte

Convey length = 30 m

Number of bends = 8

Pump vol = 0.07 m^3/sec - # 4,05 m^3/min

Dia begin = 75 mm

Dia end = 100 mm

Vacuum Capacity Max interrupt.

bar - tons/hr-vs/hr - cap.tons/hr-vs/hr - v-begin - v-end - kWh/ton - res.time

0.650 - 9 / 1 - 8 / 1 - 6.7 - 8.9 - 0.48 - 5.24

0.600 - 9 / 1 - 8 / 1 - 7.6 - 8.9 - 0.47 - 5.10

0.550 - 8 / 1 - 8 / 1 - 8.5 - 8.8 - 0.46 - 4.97

0.500 - 8 / 1 - 8 / 1 - 9.5 - 8.8 - 0.46 - 4.87

0.450 - 8 / 1 - 8 / 1 - 10.4 - 8.8 - 0.47 - 4.77

0.400 - 7 / 1 - 7 / 1 - 11.3 - 8.7 - 0.47 - 4.52

0.350 - 6 / 1 - 6 / 1 - 12.1 - 8.7 - 0.53 - 4.34

0.300 - 5 / 1 - 5 / 1 - 13.0 - 8.6 - 0.64 - 4.16

0.250 - 3 / 0 - 3 / 0 - 13.8 - 8.6 - 0.90 - 4.02

PS. I have some experience in the past and barite is rather easy to convey pneumatically, as

it is often applied on offshore supply vessels.

In case you need more info, use this forum

best regards ■

dear kevinjcg

vs/hr means vessels or blowtanks per hour (I assumed a vessel of 9 tons content)

(not really an important figure, but this program is made for double blowtank systems and therefore I have to fill in something to prevent a calculation overflow)

I recalculated the installation according your specifications :

pipebore = 50 mm

5 bends

3m vertical upwards

27 m horizontal

This results in :

kevinjcg bar s 11-08-2005

Vacuum discharge of Baryte

Convey length = 30 m

Number of bends = 5

Pump vol = 0.0675 m^3/sec # 4,05 m3/min

Dia begin = 50 mm

Dia end = 50 mm (single diameter pipeline)

Shipsize in dwt.= 11020

Vacuum Capacity Max interrupt.

bar - tons/hr-vs/hr - cap.tons/hr-vs/hr v-begin v-end kWh/ton res.time - loading ratio

0.650 - 3,9 / 0 - 3,9 / 0 - 15.0 - 34.7 - 1.13 - 2.04 - 40,6

0.600 - 3,7 / 0 - 3,7 / 0 - 17.2 - 34.6 - 1.17 - 1.80 - 33,3

0.550 - 3,4 / 0 - 3,4 / 0 - 19.3 - 34.4 - 1.22 - 1.62 - 27,4

0.500 - 3,1 / 0 - 3,1 / 0 - 21.4 - 34.3 - 1.31 - 1.49 - 22,3

0.450 - 2,7 / 0 - 2,7 / 0 - 23.5 - 34.2 - 1.44 - 1.36 - 17,7

0.400 - 2,2 / 0 - 2,2 / 0 - 25.5 - 34.2 - 1.70 - 1.30 - 13,2

0.350 - 1,6 / 0 - 1,6 / 0 - 27.3 - 34.1 - 2.22 - 1.23 - 8,9

The capacity is now much less, because of the much higher air velocities.

Note that I compared this product baryte with cement in relation to the behavior in pneumatic conveying.

(see also the thread of Mr debashide "System design calculation for pneumatic conveying")

all for now ■

dear kevinjcg

First of all, do not take these figures as 100% accuracy

(see also my note in the preveous reply)

Although I have no extensive experimental field data of baryte conveying installations, the calculation shows rather realistic and acceptable values.

Of course, it is no problem at all to do another calculation.

Please let me know how much air displacement you want to use.

My program is based on the fysical events that occur with the material itself and therefore I cannot use such a figure as equivalent length.

My problem with equivalent length is ; how to chose the pipe with the specific conditions as local loading ratio, air velocities, material velocities, absolute local pressure in comparison with which bend.

My program avoids this difficult decision.

Waiting for your reply ■

dear kevinjcg

Some of the letters in your reply are mixed up.

I cannot read the “bore” value

Forget about the equivalent length, I do not use that concept.

Which installation do you wish me to calculate ?

Take care that the mass air flow in a vacuum system varies with the under pressure.

mass flow of air = 1,293 * 273/(t+273) * (1-vacuum) * pumpdisplacement

success ■