This is a comprehensive presentation on particle density. A fundamental property in bulk solids handling.
Link to file : https://drive.google.com/open?id=1nXy3um5XY0HtGkOWlUdvXjbR6Gwk3eOR
1. What is particle density ?
For non-porous
particlesParticle density is the ratio of mass of
particle and the volume of the particle.
solid material
volume
closed pore
volume
external
void volume
interparticle
void volume
open pore
volume
For porous particles
Particle density or True density of
a particulate solid or powder, is the density
of the particles that make up the powder.
Density definitions
Volumes included in definition
Solid
material
volume
Open
pore
volume
Closed
pore
volume
Inter-
particle
void
volume
External
void
volume
Absolute powder density (BSI)
Theoretical density (ASTM)
True density (BSI)
Apparent particle density (BSI)
Skeletal density (ASTM D3766)
Effective particle density (BSI)
Envelope density (BSI)
Envelope density (ASTM D3766)
illustration of different volume types
๐๐๐๐ก๐๐๐๐ ๐๐๐๐ ๐๐ก๐ฆ(ฯp) =
๐๐๐ ๐ ๐๐ ๐๐๐๐ก๐๐๐๐
โ๐ฆ๐๐๐๐๐ฆ๐๐๐๐๐ ๐ฃ๐๐๐ข๐๐
Hydrodynamic volume is the volume โseenโ
by the ๏ฌuid in its ๏ฌuid dynamic interaction
with the particle and includes the volume of
all the open and closed pores
Particle density is the ratio of mass of
particle and the hydrodynamic volume of
the particle
Introduction to Particle Technology
by Martin Rhodes
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2. What is itโs significance ?
1. Used in modelling of solid friction factor
2. Causes increase in pressure difference in
fluidized bed
3. Effects terminal velocity of particle
4. Effects minimum fluidization velocity
5. Effects the choking velocity in pneumatic
conveying
6. For a fixed particle size the fluidization
characteristics depend on the particle density
of the bulk solid.
Geldart (1973) classification diagram
How to measure it ?
Water displacement method :
๐ ๐ =
๐๐ โ ๐๐
๐๐ โ ๐๐
๐โ๐๐๐,
๐๐ โถ ๐๐๐ ๐ ๐๐ ๐๐๐๐ ๐ข๐๐๐๐ ๐๐ฆ๐๐๐๐๐๐ ๐๐๐๐๐๐ ๐ค๐๐กโ ๐ค๐๐ก๐๐ + ๐๐๐ค๐๐๐
๐๐ โถ ๐๐๐ ๐ ๐๐ ๐๐๐๐ ๐ข๐๐๐๐ ๐๐ฆ๐๐๐๐๐๐ ๐๐๐๐๐๐ ๐ค๐๐กโ ๐ค๐๐ก๐๐
๐๐ โถ ๐๐๐๐ข๐๐ ๐๐ ๐๐๐๐ ๐ข๐๐๐๐ ๐๐ฆ๐๐๐๐๐๐ ๐๐๐๐๐๐ ๐ค๐๐กโ ๐ค๐๐ก๐๐ + ๐๐๐ค๐๐๐
๐๐ โถ ๐๐๐๐ข๐๐ ๐๐ ๐๐๐๐ ๐ข๐๐๐๐ ๐๐ฆ๐๐๐๐๐๐ ๐๐๐๐๐๐ ๐ค๐๐กโ ๐ค๐๐ก๐๐
Standard : ASTM C 693
particle density measurement in lab
3. Measuring Principle :
It is a manual method in which the density is
determined by calculating finding the volume occupied
by a sample of known weight. After placing the sample
in the pycnometer, it is filled with distilled water and
then closed by a stopper with a capillary hole in it
which allows the spare liquid to leave. Thus providing
an accurate volume and density.
water pycnometer
Standard : ASTM D854 โ 14, DIN EN 725-7
How to measure it ? Contdโฆ
๐ ๐ =
๐๐(๐ด ๐ โ ๐ด ๐)
๐ด ๐ โ ๐ด ๐ โ (๐ด ๐ โ ๐ด ๐)
๐/๐๐ ๐
Where,
๐ ๐ฌ = ๐ฉ๐๐ซ๐ญ๐ข๐๐ฅ๐ ๐๐๐ง๐ฌ๐ข๐ญ๐ฒ ๐ /๐๐ฆ ๐
๐๐ฅ = ๐ฅ๐ข๐ช๐ฎ๐ข๐ ๐๐๐ง๐ฌ๐ข๐ญ๐ฒ (๐ /๐๐ฆ ๐
)
๐ ๐ = ๐๐๐ฌ๐ฌ ๐จ๐ ๐๐ฆ๐ฉ๐ญ๐ฒ ๐ฉ๐ฒ๐๐ง๐จ๐ฆ๐๐ญ๐๐ซ ๐
๐ ๐ = ๐๐๐ฌ๐ฌ ๐จ๐ ๐ฉ๐ฒ๐๐ง๐จ๐ฆ๐๐ญ๐๐ซ + ๐ฉ๐จ๐ฐ๐๐๐ซ (๐ )
๐ ๐ = ๐๐๐ฌ๐ฌ ๐จ๐ ๐ฉ๐ฒ๐๐ง๐จ๐ฆ๐๐ญ๐๐ซ + ๐ฉ๐จ๐ฐ๐๐๐ซ + ๐ฐ๐๐ญ๐๐ซ (๐ )
๐ ๐ = ๐๐๐ฌ๐ฌ ๐จ๐ ๐ฉ๐ฒ๐๐ง๐จ๐ฆ๐๐ญ๐ + ๐ฐ๐๐ญ๐๐ซ (๐ )
Measuring Principle :
The true volume of a solid is calculated from the measured drop in pressure
when a known amount of gas is allowed to expand into a chamber containing
sample. Thus including any pore volume accessible to the gas.
Standard : ASTM D5550-06 Make/Model : Micrometrics : Accupyc II 1340
๐๐ฅ โถ ๐ ๐๐๐๐๐ก๐๐ ๐๐๐๐ก๐๐๐๐ ๐ฃ๐๐๐ข๐๐
๐๐ โถ ๐ฃ๐๐๐ข๐๐ ๐๐ ๐ ๐๐๐๐๐ ๐โ๐๐๐๐๐
๐๐ฅ โถ ๐ ๐๐๐๐๐๐ ๐๐๐๐ ๐ ๐ข๐๐ ๐๐ ๐ ๐๐๐๐๐ ๐โ๐๐๐๐๐
๐๐ โถ ๐ฃ๐๐๐ข๐๐ ๐๐ ๐๐๐๐๐๐๐๐๐ ๐โ๐๐๐๐๐
๐๐ฅ โถ ๐๐๐๐ ๐ ๐ข๐๐ ๐๐ ๐๐๐๐๐๐๐๐๐ ๐โ๐๐๐๐๐ (๐๐ > ๐๐ )
๐๐ ๐ฆ๐ โถ ๐๐๐๐ ๐ ๐ข๐๐ ๐๐ ๐ ๐ฆ๐ ๐ก๐๐ ๐คโ๐๐ ๐ฃ๐๐๐ฃ๐ ๐๐ ๐๐๐๐
๐ โถ ๐๐๐ ๐๐๐๐ ๐ก๐๐๐ก ๐ผ๐๐๐ก๐๐๐ ๐๐๐๐๐
๐ โถ ๐๐๐ ๐๐๐ข๐ก๐ ๐ก๐๐๐๐๐๐๐ก๐ข๐๐
๐ผ๐๐๐ก๐๐๐ ๐๐๐๐๐ โถ ๐๐ ( ๐๐ โ ๐๐ฅ)+ ๐๐ ๐๐=nRT ----------------------- (1)
๐ด๐๐ก๐๐ ๐ฃ๐๐๐ฃ๐ ๐๐ ๐๐๐๐๐๐ โถ ๐๐ ๐ฆ๐ ( ๐๐ + ๐๐ โ ๐๐ฅ)=nRT ----------(2)
๐๐๐๐ 1 & 2
๐๐ฅ =
(๐๐ ๐ฆ๐ ๐๐ + ๐๐ ๐ฆ๐ ๐๐ โ ๐๐ ๐๐ โ ๐๐ ๐๐)
(๐๐ ๐ฆ๐ โ ๐๐ )
gas pycnometer
4. mercury porosimeter
Measuring Principle :
The mercury porosimetry analysis technique is based on the intrusion of mercury into a porous
structure under stringently controlled pressures. Besides offering speed, accuracy, and a wide
measurement range, mercury porosimetry permits you to calculate numerous sample properties
such as pore size distributions, total pore volume, total pore surface area, median pore diameter
and sample densities (bulk and skeletal).
Standard : ISO 1183-1:2004,ASTM D854 Make/Model : Micrometrics : AutoPore V
How to measure it ? Contdโฆ
mercury intrusion into pore
space as pressure increasesintrusion volume vs pressure Summary of AutoPore V Report
Envelope volume
interparticle
void volume
skeletal volume