Pneumatic Conveying Pipe Bends
Do you have a question, a remark ? Please contact the author at firstname.lastname@example.org
# Types of pneumatic transport
# Conveying phases
# Dilute Phase transport
# Dense Phase transport
# Air mover
# Roots Blower
# Roots Blower performance curve# Filters
# After Cooler
# Airlock Rotary Valve
# Product inlet / Injector
# Choking velocity
# Conveying speed / velocity
# Air volumetric and mass flowrate
# Pipe Equivalent Length
# Solids particle velocity in pipe
# Solids Breakage
#Pipe Diameter or Bore
# Selecting dilute or dense phase# Vertical Conveying
Bends in Pneumatic Conveying lines are necessary, it is indeed very seldom to have just a straight pipe in between the pick-up point and the receiving point. However, bends can be a source of issues not always well understood by the manufacturer.
Shortly after installing a new conveying line, the following observations may be done, if problem actually arise from bends in a conveying line :
- The line is choking (blockages)
Those issues may be avoided (experience shows that problems have sometimes several root causes) if the Conveying Pipe routing had been designed differently, with less or different bends.
2. Bend Design
Bends can take several shape, from the sharpest (simple 90 degree tee) to long radius, or with more complicated and patented design. The table below gives an overview of each design available, with some remarks on design pros and cons.
Figure 1 : Regular bend designs
Table 1 : Different types of piping connections and their advantages and drawbacks
Figure 2 : Proprietary bend designs
3. Bends effects
have mainly the following process consequences :
Flexible hoses should be used with care as they are most of the time not straight, can even be very tortuous for a truck discharge for example, while they can actually be assimilated to several bends in series, thus a very unfavorable case for pressure drop.
4. Solving Problems linked to bends
Figure 3 : Product flow within a bend
Note : the drawing above is showing a flow pattern with several impact, but it may also happen, depending on the material and solids loading that the material slides on the outer part of the bend. This is what can happen in long radius bends with polymers for example and create smearing leading to angel hair when the layer of product accumulated peals off.
 Principles of Powder Technology, M.J. Rhodes, 1990, page 152
|Do you want to
know more ?
www.powderprocess.net is covering all aspects of solids and powder processing and handling
The pages below will probably interest you !
Answers ALL your questions on solids and powder mixing
of MIX / MEASURING DEGREE OF MIXING
All you need to know about measuring the degree of mixing (Coefficient of Variation) of a dry mix
OF POWDERS / DEMIXING
All on the physical phenomena causing segregation of particles and how to avoid them
All on main size reduction processes, key equipement, design consideration..etc..
All on powder key physical characteristics, among others : flowability, density...etc..
All equipment found in bulk solids handling industries, explained, with design tips...
|You can find much more through the menus at the top of the page !|