U.S. patent application number 17/837187 was filed with the patent office on 2022-09-22 for demulsification-dehydration method by using chaotic-frequency pulse group electric field.
The applicant listed for this patent is CHONGQING TECHNOLOGY AND BUSINESS UNIVERSITY. Invention is credited to Haifeng GONG, Zhixiang LIAO, Ye PENG.
Application Number | 20220298429 17/837187 |
Document ID | / |
Family ID | 1000006450963 |
Filed Date | 2022-09-22 |
United States Patent
Application |
20220298429 |
Kind Code |
A1 |
GONG; Haifeng ; et
al. |
September 22, 2022 |
DEMULSIFICATION-DEHYDRATION METHOD BY USING CHAOTIC-FREQUENCY PULSE
GROUP ELECTRIC FIELD
Abstract
A demulsification-dehydration method by using a
chaotic-frequency pulse group electric field, including: subjecting
a waste oil emulsion to the chaotic-frequency pulse group electric
field for demulsification and dehydration. The chaotic-frequency
pulse group electric field includes a plurality of pulse electric
field groups varying in pulse frequency. The pulse frequency of
each pulse electric field group varies chaotically within a preset
range. Each pulse electric field group includes a plurality of
pulses of equal frequency, duty cycle and electric field
intensity.
Inventors: |
GONG; Haifeng; (Chongqing,
CN) ; LIAO; Zhixiang; (Chongqing, CN) ; PENG;
Ye; (Chongqing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHONGQING TECHNOLOGY AND BUSINESS UNIVERSITY |
CHONGQING |
|
CN |
|
|
Family ID: |
1000006450963 |
Appl. No.: |
17/837187 |
Filed: |
June 10, 2022 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 33/02 20130101 |
International
Class: |
C10G 33/02 20060101
C10G033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 16, 2021 |
CN |
202110665685.1 |
Claims
1. A demulsification-dehydration method by using a
chaotic-frequency pulse group electric field, comprising: applying
the chaotic-frequency pulse group electric field to a waste oil
emulsion for demulsification and dehydration; wherein the
chaotic-frequency pulse group electric field comprises a plurality
of pulse electric field groups varying in pulse frequency; a pulse
frequency of each of the plurality of pulse electric field groups
experiences a chaotic change within a preset range; and each of the
plurality of pulse electric field groups comprises a plurality of
pulses of equal frequency, duty cycle and electric field
intensity.
2. The demulsification-dehydration method of claim 1, wherein a
variation of the pulse frequency of each of the plurality of pulse
electric field groups is determined by equations expressed as:
.omega. m .times. ax = 3.4152 .gamma. R m .times. i .times. n 3
.times. .rho. ##EQU00012## .omega. m .times. i .times. n = 3.4152
.gamma. R m .times. ax 3 .times. .rho. ##EQU00012.2## .omega. n =
.omega. m .times. ax .times. .omega. m .times. i .times. n ( c n +
1 ) .times. ( .omega. m .times. ax - .omega. m .times. i .times. n
) / 2 + .omega. m .times. i .times. n , n = 1 , 2 , .times. and
##EQU00012.3## c n + 1 = 1 - 2 .times. c n 2 , n = 1 , 2 , .times.
( - 1 < c 1 < 1 ) ; ##EQU00012.4## wherein .omega..sub.max is
a maximum pulse angular frequency; .omega..sub.min is a minimum
pulse angular frequency; .rho. is droplet density; R.sub.max is a
particle size of a largest droplet in the waste oil emulsion;
R.sub.min is a particle size of a smallest droplet in the waste oil
emulsion; .gamma. is an oil-water interfacial tension;
.omega..sub.n is a pulse angular frequency of a n.sup.th pulse
electric field group; and c.sub.n is a value of n.sup.th iteration
of logistic map.
3. The demulsification-dehydration method of claim 1, wherein the
number of the plurality of pulses in each of the plurality of pulse
electric field groups is determined by equations expressed as: d 2
.times. .chi. dt 2 + A .times. .phi. .function. ( .chi. ) .times. d
.times. .chi. dt + Bf .function. ( .chi. ) = Gq .function. ( t )
.times. e .function. ( .chi. ) ##EQU00013## A = 4 .times. .mu. R 2
.times. .rho. ##EQU00013.2## B = 8 .times. .gamma. R 3 .times.
.rho. .times. and ##EQU00013.3## G = 4 .times. .epsilon. 0 .times.
.epsilon. 2 .times. E 2 R 2 .times. .rho. ; ##EQU00013.4## wherein
A is a resistance constant; B is an interfacial restoring force
constant; G is an electric field excitation force constant; .mu. is
a dynamic viscosity; .sub.0 is a vacuum dielectric constant; .sub.2
is a relative dielectric constant; E is an electric field
intensity; .gamma. is an oil-water interfacial tension; R is an
initial droplet radius; .rho. is a droplet density; .chi. is a
droplet amplitude; q(t) is an electric field signal function, and
expressed as q .function. ( t ) = 1 2 + 2 .pi. .times. ( sin
.times. .omega. .times. t + 1 3 .times. sin .times. 3 .times.
.omega. .times. t + 1 5 .times. sin .times. 5 .times. .omega.
.times. t + ) ; ##EQU00014## .phi.(.chi.) is a resistance nonlinear
function; f (.chi.) is an interfacial restoring force nonlinear
function; e(.chi.) is an electric field excitation force nonlinear
function; .phi.(.chi.)=0.92-2.1.chi.+1.17.chi..sup.2;
f(.chi.)=0.25.chi.-0.06.chi..sup.2 ;
e(.chi.)=1.47-0.83.chi.+0.2.chi..sup.2 ; .omega. is an electric
field angular frequency; and t is an electric field action
time.
4. The demulsification-dehydration method of claim 1, wherein an
electric field output sequence of the chaotic-frequency pulse group
electric field is determined by an equation expressed as: E
.function. ( t ) = E ( 1 2 + 2 .pi. .times. ( sin ( .omega. i ( t -
i = 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + 1 3 .times.
sin ( 3 .times. .omega. i ( t - i = 1 n - 1 k .times. 2 .times.
.pi. .omega. i ) ) + 1 5 .times. sin ( 5 .times. .omega. i ( t - i
= 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + ) ) , n = 1 , 2
, 3 , ; ##EQU00015## wherein .omega..sub.i is an electric field
angular frequency of an i.sup.th pulse electric field group; and t
is an electric field action time.
5. The demulsification-dehydration method of claim 1, wherein in
each of the plurality of pulse electric field groups, the plurality
of pulses have a duty cycle of 0.5 and an electric field intensity
of 100-500 kV/m.
6. The demulsification-dehydration method of claim 1, further
comprising: before the chaotic-frequency pulse group electric field
is applied to the waste oil emulsion, controlling the waste oil
emulsion to 40-50.degree. C.; wherein the waste oil emulsion
comprises 10-30% by weight of water, and has a kinematic viscosity
of less than 65 mm.sup.2/s at 40.degree. C.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from Chinese
Patent Application No. 202110665685.1, filed on Jun. 16, 2021. The
content of the aforementioned applications, including any
intervening amendments thereto, is incorporated herein by reference
in its entirety.
TECHNICAL FIELD
[0002] The present application relates to a physical or chemical
method for electrically separating droplets, and more particularly
to a demulsification-dehydration method by using a
chaotic-frequency pulse group electric field.
BACKGROUND
[0003] The waste lubricating oil, known as industrial waste oil, is
an industrial hazardous waste formed by gradual aging and
deterioration of lubricating oil in use caused by solid impurity
and water pollution under the exposure to physical, chemical or
human factors. The waste lubricating oil has complex chemical
composition, and contains a large number of harmful heavy metals
and sulfur, phosphorus and chlorine-containing toxic compounds. The
waste lubricating oil should be treated properly, otherwise, it
will threaten the ecological environment. Purifying the waste
lubricating oil to restore its base oil properties can achieve the
recycle of lubricating oil, which not only protects the
environment, but also facilitates alleviating the energy resource
shortage.
[0004] At present, the demulsification and dehydration of the waste
lubricating oil is performed commonly by sedimentation, chemical,
centrifugal, electric field and vacuum methods, but these
approaches fail to achieve the high efficiency and low energy
consumption at the same time. The emerging pulse electric field
demulsification method has simple device structure, high efficiency
and low energy consumption, which is suitable for the treatment of
waste lubricating oil. It has been demonstrated that under the
action of the pulse electric field, droplets in oil undergo
vibration and deformation, and thus the strength of an oil-water
interfacial film is greatly weakened and the droplets are more
prone to agglomeration. Additionally, under the optimal electric
field frequency, the droplets will resonate, namely the deformation
amplitude reaches the maximum without breaking, which increases the
collision probability between droplets and realizes the efficient
agglomeration and demulsification of the waste lubricating oil.
[0005] Nevertheless, the pulse electric field used for
demulsification and dehydration of the waste lubricating oil is
usually a constant-frequency periodic pulse, which can only make
droplets of single particle size in the oil resonate. For an
oil-water system with constantly-changing particle size under the
action an electric field, it fails to reach an optimal resonance
frequency for all droplets, lowering the demulsification and
dehydration efficiency. Chinese patent application publication No.
111773769 A discloses a demulsification method using a
chaotic-frequency pulse electric field, in which the waste oil
emulsion is subjected to a pulse electric field with
constantly-changing frequency. This method enables the full
coverage of resonant frequencies of emulsified droplets, and the
chaotic-frequency pulse electric field with constant amplitude and
equal pulse width can also prevent adverse effects brought by the
uncertainty of the electric field amplitude and pulse width.
Notwithstanding, this common chaotic-frequency pulse may cause the
droplets to produce unsteady vibration, and the stable response
under the resonant frequency is insufficient, failing to achieve
the desired resonance state and make full use of the pulse electric
field.
SUMMARY
[0006] In order to overcome the problems in prior art, the present
disclosure provides a demulsification-dehydration method by using a
chaotic-frequency pulse group electric field to enable the
sufficient stable response of droplets at a resonant frequency
during the demulsification. A pulse frequency of the electric field
provided herein can cover resonance frequencies of all droplets in
the waste oil, and also ensure the steady-state response of
droplets, allowing for improved demulsification and dehydration
efficiency.
[0007] Technical solutions of the disclosure are described as
follows.
[0008] A demulsification-dehydration method by using a
chaotic-frequency pulse group electric field, comprising:
[0009] applying the chaotic-frequency pulse group electric field to
a waste oil emulsion for demulsification and dehydration;
[0010] wherein the chaotic-frequency pulse group electric field
comprises a plurality of pulse electric field groups varying in
pulse frequency; a pulse frequency of each of the plurality of
pulse electric field groups experiences a chaotic change within a
preset range; and each of the plurality of pulse electric field
groups comprises a plurality of pulses of equal frequency, duty
cycle and electric field intensity.
[0011] In some embodiments, a variation of the pulse frequency of
each of the plurality of pulse electric field groups is determined
by equations expressed as:
.omega. m .times. ax = 3.4152 .gamma. R m .times. i .times. n 3
.times. .rho. ##EQU00001## .omega. m .times. i .times. n = 3.4152
.gamma. R m .times. ax 3 .times. .rho. ##EQU00001.2## .omega. n =
.omega. m .times. ax .times. .omega. m .times. i .times. n ( c n +
1 ) .times. ( .omega. m .times. ax - .omega. m .times. i .times. n
) / 2 + .omega. m .times. i .times. n , n = 1 , 2 , .times. and
##EQU00001.3## c n + 1 = 1 - 2 .times. c n 2 , n = 1 , 2 , .times.
( - 1 < c 1 < 1 ) ; ##EQU00001.4##
[0012] wherein .omega..sub.max is a maximum pulse angular
frequency; .omega..sub.min is a minimum pulse angular frequency;
.rho. is droplet density; R.sub.max is a particle size of a largest
droplet in the waste oil emulsion; R.sub.min is a particle size of
a smallest droplet in the waste oil emulsion; .gamma. is an
oil-water interfacial tension; .omega..sub.n is a pulse angular
frequency of a n.sup.th pulse electric field group; and c.sub.n, is
a value of n.sup.th iteration of logistic map.
[0013] In some embodiments, the number of the plurality of pulses
in each of the plurality of pulse electric field groups is
determined by equations expressed as:
d 2 .times. .chi. dt 2 + A .times. .phi. .function. ( .chi. )
.times. d .times. .chi. dt + Bf .function. ( .chi. ) = Gq
.function. ( t ) .times. e .function. ( .chi. ) ##EQU00002## A = 4
.times. .mu. R 2 .times. .rho. ##EQU00002.2## B = 8 .times. .gamma.
R 3 .times. .rho. .times. and ##EQU00002.3## G = 4 .times.
.epsilon. 0 .times. .epsilon. 2 .times. E 2 R 2 .times. .rho. ;
##EQU00002.4##
[0014] wherein A is a resistance constant; B is an interfacial
restoring force constant; G is an electric field excitation force
constant; .mu. is a dynamic viscosity; .sub.0 is a vacuum
dielectric constant; .sub.2 is a relative dielectric constant; E is
an electric field intensity; .gamma. is an oil-water interfacial
tension; R is an initial droplet radius; .rho. is a droplet
density; .chi. is a droplet amplitude; q(t) is an electric field
signal function, and expressed as
q .function. ( t ) = 1 2 + 2 .pi. .times. ( sin .times. .omega.
.times. t + 1 3 .times. sin .times. 3 .times. .omega. .times. t + 1
5 .times. sin .times. 5 .times. .omega. .times. t + ) ;
##EQU00003##
.phi.(.chi.) is a resistance nonlinear function; f (.chi.) is an
interfacial restoring force nonlinear function; e(.chi.) is an
electric field excitation force nonlinear function;
.phi.(.chi.)=0.92-2.1.chi.+1.17.chi..sup.2;
f(.chi.)=0.25.chi.-0.06.chi..sup.2 ;
e(.chi.)=1.47-0.83.chi.+0.2.chi..sup.2; .omega. is an electric
field angular frequency; and t is an electric field action
time.
[0015] In some embodiments, wherein an electric field output
sequence of the chaotic-frequency pulse group electric field is
determined by an equation expressed as:
E .function. ( t ) = E ( 1 2 + 2 .pi. .times. ( sin ( .omega. i ( t
- i = 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + 1 3 .times.
sin ( 3 .times. .omega. i ( t - i = 1 n - 1 k .times. 2 .times.
.pi. .omega. i ) ) + 1 5 .times. sin ( 5 .times. .omega. i ( t - i
= 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + ) ) , n = 1 , 2
, 3 , ; ##EQU00004##
[0016] wherein .omega..sub.i, is an electric field angular
frequency of an i.sup.th pulse electric field group; and t is an
electric field action time.
[0017] In some embodiments, in each of the plurality of pulse
electric field groups, the plurality of pulses have a duty cycle of
0.5 and an electric field intensity of 100-500 kV/m.
[0018] In some embodiments, the demulsification-dehydration method
further comprises:
[0019] before the chaotic-frequency pulse group electric field is
applied to the waste oil emulsion, controlling the waste oil
emulsion to 40-50.degree. C.;
[0020] wherein the waste oil emulsion comprises 10-30% by weight of
water, and has a kinematic viscosity of less than 65 mm.sup.2/s at
40.degree. C.
[0021] Compared to the prior art, this application has the
following beneficial effects.
[0022] (1) Regarding the demulsification-dehydration method
provided herein, the chaotic-frequency pulse group electric field
excites a droplet vibration in waste oil. Compared with the
existing method using frequency pulse electric field, the
chaotic-frequency pulse group electric field has the following
characteristics. (a) Each pulse electric field group includes
multiple pulses of equal frequency, duty cycle and electric field
intensity. (b) The pulse frequency varies chaotically between the
pulse electric field groups, i.e., the pulse frequency varies
within the preset range but never repeats. The pulse frequency of
the chaotic-frequency pulse group electric field is chaotic between
the pulse electric field groups but constant within each pulse
electric field group, with both chaotic and periodic
characteristics, which can full cover a resonant frequency of a
droplet electric field, and can make droplets vibrate at each pulse
frequency to reach a steady state. Therefore, all droplets in the
waste oil can respond effectively at their own resonant frequency
and reach the resonant amplitude, effectively enhancing an
agglomeration and demulsification ability of the chaotic-frequency
pulse group electric field.
[0023] (2) Regarding the demulsification-dehydration method
provided herein, the duty cycle is 0.5, which can avoid too small a
duty cycle leading to insufficient droplet deformation and
affecting a demulsification efficiency, and prevent unnecessary
energy consumption caused by too large a duty cycle.
[0024] (3) Regarding the demulsification-dehydration method
provided herein, each pulse electric field group consists of
multiple pulses with equal frequency, duty cycle and electric field
intensity to ensure the steady-state response of the droplet. The
duty cycle and a frequency determination algorithm are adjusted. A
pulse width is controlled by the frequency. An electric field
confirmation function is adjusted. The frequency is subjected to
reciprocating iteration between the resonant frequencies of each
droplet, varying constantly, and generally responding to an optimal
demulsification frequency for all droplets. Compared with the
existing method using frequency pulse electric field, the
demulsification-dehydration method provided herein has better
effect and efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 schematically depicts a chaotic-frequency pulse group
electric field according to an embodiment of the present
disclosure;
[0026] FIG. 2 is a frequency spectrum of a chaotic-frequency pulse
group according to an embodiment of the present disclosure;
[0027] FIG. 3 schematically depicts a vibration response of a
droplet at different initial values of vibration according to an
embodiment of the present disclosure;
[0028] FIG. 4 schematically depicts a signal of the
chaotic-frequency pulse group electric field according to an
embodiment of the present disclosure;
[0029] FIG. 5 schematically depicts a vibration response of a
droplet in the chaotic-frequency pulse group electric field
according to an embodiment of the present disclosure; and
[0030] FIG. 6 shows comparison of vibration amplitudes of the
droplet in different electric fields.
DETAILED DESCRIPTION OF EMBODIMENTS
[0031] The disclosure will be described in detail below with
reference to the accompanying drawings and embodiments.
[0032] In an embodiment of a demulsification-dehydration method by
using a chaotic-frequency pulse group electric field, a waste oil
emulsion is subjected to pretreatment, where the waste oil emulsion
includes 10-30% by weight of water, and has a kinematic viscosity
of less than 65 mm.sup.2/s at 40.degree. C. The waste oil emulsion
is filtered to remove mechanical impurities, and then enters a heat
exchanger to control the waste oil emulsion to 40-50.degree. C.
Further, the waste oil emulsion is subjected to demulsification and
dehydration after entering an electric field demulsifier followed
by an oil storage device.
[0033] Referring to FIG. 1, the electric field demulsifier applies
the chaotic-frequency pulse group electric field to the waste oil
emulsion for demulsification and dehydration. The chaotic-frequency
pulse group electric field includes multiple pulse electric field
groups varying in pulse frequency. The pulse electric field groups
are applied to the waste oil emulsion in time sequence. A pulse
frequency of each pulse electric field group experiences a chaotic
change within a preset range and never repeat. Each pulse electric
field group includes multiple pulses of equal frequency, duty cycle
and electric field intensity. The pulses are applied to the waste
oil emulsion in time sequence.
[0034] A variation of the pulse frequency of each pulse electric
field group is determined by equations expressed as:
.omega. m .times. ax = 3.4152 .gamma. R m .times. i .times. n 3
.times. .rho. ##EQU00005## .omega. m .times. i .times. n = 3.4152
.gamma. R m .times. ax 3 .times. .rho. ##EQU00005.2## .omega. n =
.omega. m .times. ax .times. .omega. m .times. i .times. n ( c n +
1 ) .times. ( .omega. m .times. ax - .omega. m .times. i .times. n
) / 2 + .omega. m .times. i .times. n , n = 1 , 2 , ##EQU00005.3##
c n + 1 = 1 - 2 .times. c n 2 , n = 1 , 2 , .times. ( - 1 < c 1
< 1 ) ; ##EQU00005.4##
[0035] where .omega..sub.max is a maximum pulse angular frequency;
.omega..sub.min is a minimum pulse angular frequency; .rho. is
droplet density; R.sub.max is a particle size of a largest droplet
in the waste oil emulsion; R.sub.min is a particle size of a
smallest droplet in the waste oil emulsion; .gamma. is an oil-water
interfacial tension; .omega..sub.n is a pulse angular frequency of
a n.sup.th pulse electric field group; and c.sub.n is a value of
n.sup.th iteration of logistic map.
[0036] The number of the multiple pulses in each pulse electric
field group is determined by equations expressed as:
d 2 .times. .chi. dt 2 + A .times. .phi. .function. ( .chi. )
.times. d .times. .chi. dt + Bf .function. ( .chi. ) = Gq
.function. ( t ) .times. e .function. ( .chi. ) ##EQU00006## A = 4
.times. .mu. R 2 .times. .rho. ##EQU00006.2## B = 8 .times. .gamma.
R 3 .times. .rho. ##EQU00006.3## G = 4 .times. .epsilon. 0 .times.
.epsilon. 2 .times. E 2 R 2 .times. .rho. ; ##EQU00006.4##
[0037] where A is a resistance constant; B is an interfacial
restoring force constant; G is an electric field excitation force
constant; .mu. is a dynamic viscosity; .sub.0 is a vacuum
dielectric constant; .sub.2 is a relative dielectric constant; E is
an electric field intensity; .gamma. is an oil-water interfacial
tension; R is an initial droplet radius; .rho. is a droplet
density; .chi. is a droplet amplitude; q(t) is an electric field
signal function, and expressed as
q .function. ( t ) = 1 2 + 2 .pi. .times. ( sin .times. .omega.
.times. t + 1 3 .times. sin .times. 3 .times. .omega. .times. t + 1
5 .times. sin .times. 5 .times. .omega. .times. t + ) ;
##EQU00007##
.phi.(.chi.) is a resistance nonlinear function; f (.chi.) is an
interfacial restoring force nonlinear function; e(.chi.) is an
electric field excitation force nonlinear function;
.phi.(.chi.)=0.92-2.1.chi.+1.17.chi..sup.2;
f(.chi.)=0.25.chi.-0.06.chi..sup.2 ;
e(.chi.)=1.47-0.83.chi.+0.2.chi..sup.2; .omega. is an electric
field angular frequency; and t is an electric field action
time.
[0038] An electric field output sequence of the chaotic-frequency
pulse group electric field is determined by an equation expressed
as:
E .function. ( t ) = E ( 1 2 + 2 .pi. .times. ( sin ( .omega. i ( t
- i = 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + 1 3 .times.
sin ( 3 .times. .omega. i ( t - i = 1 n - 1 k .times. 2 .times.
.pi. .omega. i ) ) + 1 5 .times. sin ( 5 .times. .omega. i ( t - i
= 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + ) ) , n = 1 , 2
, 3 , ; ##EQU00008##
[0039] where .omega..sub.i, is an electric field angular frequency
of an pulse electric field group; and t is an electric field action
time.
[0040] In each pulse electric field group, the pulses have a duty
cycle of 0.5 and an electric field intensity of 100-500 kV/m.
[0041] Provide below is an example.
[0042] Physical parameters of a oil-water system measured by test
instruments are shown in Table 1.
TABLE-US-00001 TABLE 1 Physical parameters of waste oil emulsion
Density Dynamic Relative Interfacial Particle Vacuum .rho.
viscosity .mu. dielectric tension .gamma. size R dielectric
(kg/m.sup.3) (Pa s) constant .di-elect cons..sub.2 (N/m) (m)
constant .di-elect cons..sub.0 Droplet 998 0.98 .times. 10.sup.-3
80 19 .times. 10.sup.-3 R.sub.max = 2 .times. 10.sup.-3 8.854
.times. 10.sup.-12 Oil 922 60.3 .times. 10.sup.-3 4.6 R.sub.min =
0.3 .times. 10.sup.-3
[0043] (1) For determining a frequency range .omega..sub.max and
.omega..sub.min, the above-mentioned physical parameters are input
into a frequency calculation equation, expressed as follows:
[0043] .omega. m .times. ax = 3.4152 .gamma. R m .times. i .times.
n 2 .times. .rho. = 1187.53 rad / s , ##EQU00009## .omega. m
.times. i .times. n = 3.4152 .gamma. R m .times. ax 3 .times. .rho.
= 68.99 rad / s . ##EQU00009.2##
[0044] Therefore, the frequency range of the chaotic-frequency
pulse group electric field
.omega..epsilon.(.omega..sub.min,.omega..sub.max)=(68.99,1187.53)rad/s
[0045] (2) For determining a chaos iteration of the pulse frequency
between the pulse pulse frequency groups, an initial iteration
value is set to c.sub.1=0.35. The .omega..sub.max and
.omega..sub.min are plugged into a frequency chaos iteration
equation, expressed as follows:
.omega. n = .omega. m .times. ax .times. .omega. m .times. i
.times. n ( c n + 1 ) .times. ( .omega. m .times. ax - .omega. m
.times. i .times. n ) / 2 + .omega. m .times. i .times. n , n = 1 ,
2 , . ##EQU00010##
[0046] A frequency spectrum of the chaotic-frequency pulse group is
shown in FIG. 2. (3) For determining the number of the pulses in
each electric field groups, an electric field intensity is set as
E=2.times.10.sup.5 V/m, initial values of vibration are 0.001, 0.1
and 0.2. A nonlinear vibration equation of the droplet is solved to
obtain a vibration response of a droplet having the particle size
of R.sub.max, shown in FIG. 3.
[0047] The number of vibration periods where the droplet is
stabilized by periodic vibration is the number of the pulses.
According to the vibration response, droplet completely stabilizes
after the third vibration period, such that the number of the
pulses k is 3.
[0048] (4) Since the variation and the number of pulses are
determined, an electric field output sequence of the
chaotic-frequency pulse group electric field is determined by an
equation expressed as:
E .function. ( t ) = E ( 1 2 + 2 .pi. .times. ( sin ( .omega. i ( t
- i = 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + 1 3 .times.
sin ( 3 .times. .omega. i ( t - i = 1 n - 1 k .times. 2 .times.
.pi. .omega. i ) ) + 1 5 .times. sin ( 5 .times. .omega. i ( t - i
= 1 n - 1 k .times. 2 .times. .pi. .omega. i ) ) + ) ) , n = 1 , 2
, 3 , , ##EQU00011##
results are shown in FIG. 4.
[0049] (5) The electric field output sequence is stored in a pulse
power supply by programming. A positive pole of the pulse power
supply is connected to a positive interface of an electric
dehydration device, and a negative pole of the pulse power supply
is grounded, such that the waste oil emulsion can be demulsified
and dehydrated through an electric field method.
[0050] In this example, the chaotic-frequency pulse group electric
field has chaotic and periodic characteristics, which overcomes
problems that a constant-frequency pulse electric field fails to
cover all droplet resonance frequencies in oil emulsion and a pulse
electric field with variable frequency fails to satisfy a steady
state response, maximizing a demulsification and dehydration
efficiency of pulse electric field.
[0051] Referring to FIG. 5, the vibration response of a droplet
with particle size R=1.8.times.10.sup.-3 m at the chaotic-frequency
pulse group electric field is shown. Obviously, there are a chaotic
vibration response and a periodic vibration response of the
droplet, which have a high vibration amplitude, satisfying an
expected vibration result.
[0052] Referring to FIG. 6, the constant-frequency pulse electric
field plays a good resonance effect only for droplets in a very
small particle size range, and a vibration amplitude of the
constant-frequency pulse electric field is slightly higher than a
chaotic-frequency pulse electric field and the chaotic-frequency
pulse group electric field. Nevertheless, the chaotic-frequency
pulse electric field and the chaotic-frequency pulse group electric
field enable all droplets having a high vibration amplitude, which
is better than the constant-frequency pulse electric field. In
addition, the vibration amplitude of the droplet in the
chaotic-frequency pulse group electric field is higher than that in
the chaotic-frequency pulse electric field. In consequence, the
chaotic-frequency pulse group electric field has a better vibratory
agglomeration effect.
[0053] Described above are only some embodiments of the present
disclosure, which are not intended to limit the disclosure. Any
modifications and replacement made by those of ordinary skilled in
the art without departing from the spirit of the disclosure should
fall within the scope of the disclosure defined by the appended
claims.
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