UNCLASSIFIEL
orces
the welocity is the vector sum of the velocities given bv (7) and.
For particles subjected to elsctrostatic and gravitational
(3) corrected by equation (Ll).
[fe Laws Governing the Charging of Particles
Particles may acquire charges by passing rough a region containing ions
of a given sign either ty diffusion or field charging. In the
fbrwer,
the mechanism is one of impingement of the particles with the
due
to the kinetic energy of the gas, whereas in the latter the imp
4s assisted by the energy imparted by the electrostatic field.
(a)
ent
For diffusion charging, the equation given by white
a xt
“+ (5 a} *
(+
Tacwo
xt
)
b
gives the number of electronic charges which will be acquiled by
@ particle of diameter d.
(>)
For field charging, Peuthenier has given the following
as modified by Dallavale for a cylindrical electrostatic
cipitator.
.
ky <1
a? g
——j
Wet
|
(
1
Pauthenier has shown that the potential distribution in
cylinder
fanction as the corona current increases from sero, exc
small region around the wire. Under these conditions thq@
for &
field
Pa
with central co-axial wire changes fron logarithmic to a Pinssr
intensity will be given by
=
-.,
a
v
eee AEE aes od*
the
(¢) Sleetrical considerstions of the charger.
ver
24
Es
ky
;
s
.
a
~
)
sum of the charges given by both methods, it is felt that! considering the mechanisms involwed, the particle charge will
be
given by the greater of the two effects. In any case, this
gives a mre conservative result.
+
at
, +
aw
-
1 Me]
ti
Although othershave asgumed that the particle will ecquifte
i?
tion
-78~
UNCLASSIFIED
o
1051099
imei
00131986.070
ee
|
AILS