Pipe equivalent length in pneumatic transportPipe equivalent length for calculation of pressure drop in conveying pipesDo you have a question, a remark ? Please contact the author at powder.process@protonmail.com 

Pneumatic
Transport
# Types of pneumatic transport # Conveying phases # Dilute Phase transport # Dense Phase transport # Air mover # Roots Blower #
Roots Blower performance curve
# After Cooler # Airlock Rotary Valve # Product inlet / Injector # Piping #
Filters
#
Choking velocity
# Conveying speed / velocity # Air volumetric and mass flowrate # Pipe Equivalent Length # Solids particle velocity in pipe # Bends # Solids Breakage #Pipe Diameter or Bore
# Selecting dilute or dense
phase

1. DefinitionSeveral methods to calculate the pressure drop expected in a pneumatic conveying pipe and design it is using the notion of equivalent pipe length. This notion is actually quite convenient to simplify the calculation of pressure drop. It converts the singularities of the pipe layout (vertical sections, bends, valves...etc...) into an equivalent length of straight horizontal pipe which is representing the same pressure drop as the singularity. This page is explaining different ways to calculate the pipe equivalent length. 2. Calculation of pipe equivalent length  simplified methodA very simple way to calculate the equivalent length is to count on the pipe layout the length of horizontal pipe, vertical pipes and the number of bends. The pipe equivalent length can be estimated in this shortcut method by L_{e} = L_{h}+2*L_{v}+5*NB With :  Le = equivalent length of the pipe (m) Lh = length of horizontal pipe in the whole pipe layout (m)  Lv = length of vertical pipe in the whole pipe layout (m)  NB = number of bends Do not use this method for detail design. But it can be useful for a preproject or quite troubleshooting on a production line. The method above assimilates
any 90 degrees bends to a pipe length of 5 m. Note that
Rhodes in Principles of Powder Technology recommends a
value of 7.5 m. 3. Calculation of pipe equivalent length  detailed methodTo get more precision, it is required to consider pipe singularities according to their type. Some recommendations are given by Agarwal [1] in an article published in 2005.
Source [1] Theory and design of dilute phase pneumatic conveying systems, Agarwal, Powder Handling and Processing, 2005 
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