The following sequence of analysis can be proposed for mixing equipment [1–6]:

• determination of the required technico-economic effect;

• selection of the type of mixing and the design of the mixer, with the use of which the required technico-econom-

ic effect can be achieved;

• selection of the dimensions and calculation of the capacity of the mixing equipment, which are required to achieve

the required technico-economic effect;

• comparison of specified mixer designs and selection of the design that makes it possible to achieve the required

technico-economic effect at minimum cost; and

• strength analyses.

The sequence of analysis of a electrohydrodynamic emulsifier [7] is similar. Moreover, the diameter of the water

drop (10–50 µm) is a required technico-economic parameter for the production of fuel emulsions. Having selected the inter-

electrode distance and supply voltage, and the geometry of the electrodes, it is possible to determine the specific energy out-

lays to achieve the required effect. Longitudinal and successive sectioning should then be performed, having determined the

number of parallel cells needed to achieve the required output, and the number of successive cells ensuring the required tech-

nico-economic effect.

Basic stage of analysis – determination of power consumed in emulsifying process.

In analyzing, for example, electrostatic precipitators [8], it is first recommended to determine the critical strength of

the electric field for which a discharge will develop, and then, based on this value, the critical voltage between the corona-form-

ing and receiving electrodes at the corona discharge. Having determined the ionic mobility and the linear current density, the

power (kW) required by the electrostatic precipitator is calculated:

where Um is the peak voltage,Iavg is the average strength of the current,Rs = 1.2–1.5 is the current-shape factor,ηe = 0.8 is

the efficiency of the electric unit, and 1.41 is the factor of conversion from the peak to the effective voltage.

The sequence of analysis in question can also be used in analyzing an electrohydrodynamic emulsifier. Having

selected the intensity in the interval between the critical voltage at the start of dispersion and the break-down voltage for the

operating system in question, it is possible to calculate the strength of the current in accordance with Ohm’s law, using the

conductivities of the system and the area of the electrode, and then calculate the required power of the transformer [8, 9].

In calculating the dispersion voltage, it is possible to proceed from the fact that in cylindrical horizontal housings

(diameter of 3400 mm, but of different lengths) of ÉG63-18K-92, ÉG63-18K-92-01, ÉG100-18U, ÉG100-18U-01, and 2ÉG160-

2 electric desiccators manufactured on industrial scales, the electrodes are installed at distances of 200–300 mm (a supply volt-

PU I Rm= avg s

e

cos

.,

ϕη1 41

Chemical and Petroleum Engineering, Vol. 37, Nos. 11–12, 2001

ALGORITHM FOR ANALYSIS OF ELECTROHYDRODYNAMIC

EMULSIFIERS

K. V. Tarantsev and K. R. Tarantseva UDC 66.063.61:537.84

Penza Institute of Technology. Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 11, pp. 7–8,

November, 2001.

0009-2355/01/1112-0556$25.00 ©2001 Plenum Publishing Corporation556

age ranging from 22 to 44 kV in five levels,installed capacity 50 kW). The upper voltage limit is determined by the critical field

strength [10,11] Ecr = A√ 2σ/εdh. Above this field strength,large drops of emulsion are dispersed rather rapidly.

The break-down voltages are determined with consideration given to relationships for the electric analysis of insu-

lated intervals with a length l for transformer oil [9].

For the design voltage (frequency of 50 Hz),the length of the insulated interval, or what is the same thing, the design

voltage for a known length of interval is determined from the empirical formulas

l = 0.00876Ud1.428, Ud = 27.6l 0.7

for theneedle–needleinterval when Ud = 50–920 kV (or when l = 3–150 cm),

l = 0.01276Ud1.428, Ud = 21.2l 0.7

for theneedle–plane interval when Ud = 50–725 kV(or when l = 3–150 cm),and

for the interval between the two coaxial cylinders.

Coating of the outer surface of the inner cylinder with a layer of insulation (for example, paper) with a thickness of

5–15 mm raises the discharge voltage by 20–30%.

The following algorithm is proposed for analysis of electrohydrodynamic emulsifiers.

1. Determine the required saving.

2. Select the dimensions and shape of the electrodes.

3. Determine the conductivity and break-down voltage of the working medium.

4. Calculate (determine experimentally) the critical voltage of the start of emulsification.

5. Determine the working voltage and current strength.

6. Calculate the power to achieve the required technico-economic effect.

7. Determine the optimum rate of the process and correct the dimensions and shape of the electrodes to achieve min-

imum power.

REFERENCES

1. G. L. Vikhman and S. A. Kruglov, Fundamentals of the Design and Analysis of Vessels and Machinery for Oil

Refineries [in Russian],Mashinostroenie, Moscow (1987).

2. Yu. I. Gusev et al., Design and Analysis of Machinery for Chemical Processes[in Russian],Mashinostroenie,

Moscow (1985).

3. A. A. Lashchinskii, Design of Welded Chemical Vessels:Handbook[in Russian],Mashinostroenie, Leningrad

(1981).

4. M. F. Mikhalev et al.,Analysis and Design of Machinery and Vessels for Chemical Processes: Examples and

Problems[in Russian],Mashinostroenie, Leningrad (1984).

5. V. I. Sokolov, Fundamentals of the Analysis and Design of Machinery and Vessels for the Foodstuff Industry [in Rus-

sian],Kolos,Moscow (1992).

6. Z. A. Vasil’tsev and V. G. Ushakov, Vessels for Mixing Liquid Media:Reference Manual [in Russian],Mashinos-

troenie, Leningrad (1979).

U r rR

rd = +( )

7 1 11 7. . ln

557

7. Russian Federation Patent No. 1780822,MKI B 01 F 13/06,“Electrodynamic disperser,” Byull. Izobr., No. 46

(1993).

8. G. M. Aliev, Feed Systems for Electrostatic Precipitators [in Russian],Énergoizdat, Moscow (1981).

9. Manual on High-Voltage Electrical Equipment[in Russian],edited by V. V. Afanas’ev, Énergoizdat, Leningrad

(1987).

10. V. V. Papko, “Study of the breakdown of “water-in-oil” emulsions in electrical fields and development of recom-

mendations for rational use of electric fields for electrodemulsification,” Dissertation for Candidate of Technical Sci-

ences, Moscow (1979).

11. G. M. Panchenkov and L. K. Tsabek,Emulsion Behavior in External Electric Fields[in Russian],Khimiya,Moscow

(1969).

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