8/11/2019 Pneumatic Conveying Design.doc

1/7

Pneumatic Conveying Design

One of the most popular methods of moving solids in the chemical industry is pneumatic conveying. Pnconveying refers to the

moving of solids suspended in or forced by a gas stream through horizontal

and/or vertical pipes. Pneumatic conveying can be used for particles ranging

from fine powders to pellets and bulk densities of 1 to !"## kg/m !$1 to "##lb/ft!%.

Dilute phase vs. Dense phase conveying

&he specifying engineer typically has four choice in specifying a pneumatic conveying system.

1. Dilute phase vacuum operation

". Dilute phase pressure operation!. Dilute phase pressure'vacuum operation

(. Dense phase pressure operation

)acuum systems allow multiple product inlets through the use of simple diverter valves. *owever+ it be

costly to have multiple destinations because each must have its own filter receiver with partial vacuum capa)acuum systems are also more ,distance sensitive, than pressure systems due to the ma-imum pressure diff

of . to .# psi. Dilute phase pressure systems can easily achieve pressure differentials of 1" psi. Pressur

vacuum operation $utilizing both methods% are sometimes ideal for a given conveying setup. very commo

application is the unloading of a standard railcar. 0ince the cars cannot be pressurized+ air is pulled from thoutside+ through the car $carrying solids with it% to a filter. &hen after the filter+ a blower can be used to forw

solids to the final receiver.

&he choice between dilute and dense phase operation is typically dependent on the solids properties. oe-ample+ the lower velocity bulk phase operation is popular ofr highly abrasive products or for those that de

easily. or e-ample+ this method is popular in transporting kaolin clay.

8/11/2019 Pneumatic Conveying Design.doc

2/7

8/11/2019 Pneumatic Conveying Design.doc

3/7

Designing a system for Dilute Phase Operation

2ssume a system with the following parameters3

"## feet of straight pipe

" 4# degree elbows5ulk density of # lb/ft!$4# kg/m!%

0ystem capacity of "+### lb/h $about 11!(# kg/h%

22&he design information used here assumes that air is the carrier gas+ but for preliminary design+ these cha

be sufficient for other gases such as nitrogen. Please be aware that using air as a carrier gas should be

investigated thoroughly. When some powders are mixed with oxygen, they form an explosive mixture

&he use of nomographs shown herein along with the additional tables can be used for an initial design.

Step #1: Determine the equivalent length of pipe for the system

or this type of calculation+ 4# degree elbows have an e6uivalent length of " feet $7. m% while ( degr

elbows have an e6uivalent length of 1 ft $(. m%. &hus for our e-ample3

86. 9ength : "## ft ; " $" ft% : "# ft

Step #2: Choose an initial gas velocity to move the particles

8/11/2019 Pneumatic Conveying Design.doc

4/7

Print )ersion *ere

or our system+ we have an initial gas velocity of 71# ft/min $"174 m/min%.

Step #3: Assume a pipe diameter and read the required air volume

rom Chart 1 $Print version%+ draw a straight line from the initial velocity to the assumed pipe diameter a

continue the line to the air volume. or our system+ we=ll start with a common ( inch pipe diameter. &his

procedure yields an initial air volume of 1# ft!/min.

http://www.cheresources.com/pnuconvey1.shtmlhttp://www.cheresources.com/pnuconvey2.shtmlhttp://www.cheresources.com/pnuconvey1.shtmlhttp://www.cheresources.com/pnuconvey2.shtml

8/11/2019 Pneumatic Conveying Design.doc

5/7

Step #4: ind the solids ratio

http://www.cheresources.com/pnuconvey3.shtml

8/11/2019 Pneumatic Conveying Design.doc

6/7

8/11/2019 Pneumatic Conveying Design.doc

7/7

$ther (esources *ree #oftware " Physical Properties " #ubmit an +ritlce " in'ing to Us "

areer (esearch " Why h%/ " #taff " 0 1 +2s

in' -irectoriesh% in's Technical -irectory " heresources Partner -irectory

*ree Publications

*ree Trade Publications from heresources

+dvertise with Us+dvertise 3our ompany, Products, or #ervices

ontact Us#end Us 3our *eedbac'

&he Chemical 8ngineers= >esource Page+ 1((" ?oswick >idge >oad+ @idlothian+ ) "!11(+ 8mailll material is Copyright A "##(+ www.cheresources.com

http://www.cheresources.com/other_resources.shtmlhttp://www.cheresources.com/sheetszz.shtmlhttp://www.cheresources.com/physinternetzz.shtmlhttp://www.cheresources.com/submit.shtmlhttp://www.cheresources.com/link.shtmlhttp://www.cheresources.com/interview.pdfhttp://www.cheresources.com/whyzz.shtmlhttp://www.cheresources.com/staff.shtmlhttp://www.cheresources.com/questions/index.phphttp://www.cheresources.com/link_directory.shtmlhttp://www.cheresources.com/chelinks/index.shtmlhttp://www.cheresources.com/other/chepartners.shtmlhttp://cheresources.tradepub.com/http://cheresources.tradepub.com/http://www.cheresources.com/adzz.shtmlhttp://www.cheresources.com/adzz.shtmlhttp://www.cheresources.com/suggestzz.shtmlhttp://www.cheresources.com/suggestzz.shtmlhttp://www.cheresources.com/suggestzz.shtmlhttp://www.cheresources.com/pnuconvey5.shtmlhttp://www.cheresources.com/other_resources.shtmlhttp://www.cheresources.com/sheetszz.shtmlhttp://www.cheresources.com/physinternetzz.shtmlhttp://www.cheresources.com/submit.shtmlhttp://www.cheresources.com/link.shtmlhttp://www.cheresources.com/interview.pdfhttp://www.cheresources.com/whyzz.shtmlhttp://www.cheresources.com/staff.shtmlhttp://www.cheresources.com/questions/index.phphttp://www.cheresources.com/link_directory.shtmlhttp://www.cheresources.com/chelinks/index.shtmlhttp://www.cheresources.com/other/chepartners.shtmlhttp://cheresources.tradepub.com/http://cheresources.tradepub.com/http://www.cheresources.com/adzz.shtmlhttp://www.cheresources.com/adzz.shtmlhttp://www.cheresources.com/suggestzz.shtmlhttp://www.cheresources.com/suggestzz.shtmlhttp://www.cheresources.com/suggestzz.shtml