Hydrodynamic cavitation and its applications in food

1. HYDRODYNAMIC
CAVITATION
Presented by
Sadhana.T
M. Tech in Food Science and Technology

3. What is Cavitatvion
 Rapid formation and collapse of vapour bubbles within a liquid
 Cavitation mainly occurs when the static pressure becomes smaller than
the liquids vapour pressure

4.  The cavitation occurs by pressure variation in the flowing liquid due
to the presence of throttling devices such as venturi, orifice etc., it is
called as hydrodynamic cavitation.

5. Reasons for cavitation
 Static pressure decreases below the vapour pressure
 Other factors such as fluid contamination and dissolved gas in the
fluid are neglected
Formation of vapour bubbles

6.  Bernoulli’s Principle describes the hydrodynamic cavitation .
Pstatic + Pdynamic=Constant=Pstatic + ½ ρν2

7. why only in certain areas
of fluid cavitation is
formed?
Higher pressure
exposed to the flow
Lower pressure regions
Collapse above vapour
pressure region

8. Acoustic Hydrodynamic
1. The pressure variations in the
liquid are affected by sound
waves, usually ultrasound
(> 20 kHz)
1. Compression and Rarefaction
cycles
2. Transient cavitation
1. The variation of pressure through
a constriction channel such as
venturi, orifice, etc., with different
geometries
2. Static and dynamic pressure
3. Stable and Transient cavitation

9. S.No Reactants Productcs Cavitational yield
in hydrodynamic
cavitation reactor
(gm/J)
Cavitational
yield in
acoustic
cavitation
reactor (gm/J)
1. Mesitylene Trimesic acid 7*10 -6 1*10 -6
2. o-
Nitrotoluene
o-Nitrobenzoic acid 1.9*10 -6 1*10 -6
3. Toluene Benzoic acid 3.3*10 -6 5.6*10 -6
•Comparative results - Oxidation of toluene, mesitylene, (o-/m)-nitrotoluene
Parag R. Gogate, Aniruddha B. Pandit(2004)

10. Schematic representation of
Hydrodynamic Cavitation (HC ) reactor
1. Reservoir
2. Cooling water jacket
3. Centrifugal Pump
4. Orifice plate or venturi tube
5.Bypass line (for controlling
the inlet pressure and the
flow rate into the cavitation
chamber)
P1, P2 = Pressure Gauges; V1, V2, V3 = Control Valves

11. Principle:
Cavity Expansion Max-radius Collapse Bang
•High magnitude pressure pulse- 100 to 500 atm
•Extremly high temperature 1000-1200 K
•Velocity 2-3 times more than sound
•Free radicals production

12. Hydrodynamic Cavitation Reactor
 HC is usually generated by providing a suitable constriction in a
liquid flow.
 Venturi
 Orifice
 High-speed homogenizer,
 High-pressure homogenizer
 High-speed rotor

13. Configuration of orifice-based cavitating device
with single- and multiple-hole orifices
Configuration of venturi. (A) Slit venturi,
(B) circular venturi, and (C) elliptical venturi

14. The effect of selected parameters on the cavitation
intensity in liquid flow for two different flow geometries
Venturi tube Multi perforated orifice plate
Because of a higher contribution of the transient cavitation
the cavitation intensity of an orifice system will be higher
compared to a classical venturi
Moholkar and Pandit(2001)

15. HIGH-SPEED ROTOR

16. High-pressure homogenizer

17. Physicochemical effects produced during the cavitation
process

18. APPLICATIONS
Waste water treatment
Microbial cell disruption
Synthesis of Nano particles
Chemical reactions
Food processing

19. Food Processing
HC was found to be a more effective technique as compared with
AC and other high-pressure methods in the fluid food processing
 Ambient conditions
 No external heating
 lower operating pressures

20. Review of literature
Titile Research outcome Reference
Inactivation of food
spoilage microorganisms by
hydrodynamic cavitation to
achieve pasteurization and
sterilization of fluid foods.
Sterilization of apple juice
• Inactivation of various M.O present in apple
juice such as Lactobacillus plantarum,
Lactobacillus sakei, and ascospores, 3000 and
3600 rpm rotor speeds with exit temperatures of
65.6°C and 76.7°C.
Milly et al.
(2007))
Improvement of rheological
and functional properties of
Milk Protein Concentrate by
hydrodynamic cavitation
Improvement of rheological and functional
properties of Milk Protein Concentrate by HDC.
•Viscosity - 20 % and 56%,solubility- 97.5 %
Krystel Li,
Meng Wai
Woo et
al.,(2017)

21. Chemical reactions
The formation of highly
reactive hydroxyl radicals
(˙OH) because of the
dissociation of water molecules
under cavitating conditions.
(Saharan et al. 2013)
H2 O •OH + •H

22. Review of literature
Titile Research outcome Reference
Quantification of chemical
effects of hydrodynamic
cavitation.
Measured the efficiency of orifice-based
HC devices and optimized the geometry
based on the reaction yield of iodine.
•They had observed that iodide ion (I−)
oxidizes into iodine by the attack of ˙OH
radicals.
Senthilkum
ar et al.
(2016)
Oxidation of alkylarenes
using aqueous potassium
permanganate under
cavitation: comparison of
acoustic and HD.
produced aryl carboxylic acid by the
oxidation of alkyl arenes in the presence of
aqueous KMnO4 using HC
•maximum yield of 53%
Ambulgekar
et al. (2004,
2005)

23. The degradation of persistent organic
pollutants – ‘waste water treatment’
The two key mechanisms responsible for the degradation of organic
pollutants
 The thermal decomposition/pyrolysis
 The reaction of free radicals with the organic pollutant
.OH+.OH H2O2
H2 O •OH + •H

24. Review of literature
Title Research outcome Reference
Effect of process intensifying
parameters on the
hydrodynamic cavitation
based degradation of
commercial pesticide
(methomyl) in the aqueous
solution.
Investigated the degradation of Methomyl in a
hydrodynamic cavitation reactor
•Intensifying agents such as H2O2, fenton reagent
and ozone
•Most effective process was HC + Ozone process
Raut-Jadhav
et al.(2016)
Ozone and cavitation for
water disinfection
Examined the viability of ozonation and cavitation
for the disinfection of the Bacteria in well water.
46%disinfection -15 min of ozone treatment
66%disinfection-15 min of ozone + hd treatment
Jyoti and
Pandit
(2004)

25. Synthesis of Nano particles

26. Review of literature
Titile Research outcome Reference
Novel technique for making
stable nano-suspensions.
Studied the size reduction of styrene
butadiene rubber (SBR)
•33 holes of 1 mm -4.2 atm 275 μm to 129
nm in 3 h
•1 hole of 0.6 mm-11 atm,20 nm,4 run
Patil and
Pandit (2007)
Cavitation milling of natural
cellulose to nanofibrils.
Processed natural cellulose material with
an initial size of 63 μm
•33 holes of 1 mm diameter,7.8atm
the cellulose size was reduced from 63 μm
to 136 nm in 6 h.
Pinjari and
Pandit (2010)

27. Microbial cell disruption
 The stress provided by the cavity collapse should be higher than the
cell wall strength of the microbes to break the cell wall
 Large-scale disruption of microorganisms-high speed agitator bead
mills and high-pressure homogenisers are commonly employed
(Sawant et al. 2008)

28. Review of literature
Titile Research outcome Reference
A parametrical study of
disinfection with
hydrodynamic cavitation.
Three orifice plates - (0.8, 2, and 4)mm
•The rate of E. coli inactivation increased from
0.001 to 0.004 min
•This higher flow rate and thereby generated
more cavities resulting in the higher
inactivation of E. coli..
Arrojo et al.
(2008)
Sonochemistry:
environmental science and
engineering applications.
Three different orifice plates of throat diameter
5, 10, and 12 mm.
• For removal of blue green algae, the orifice
plates were placed in the suction line, a
maximum 20% removal of algae was obtained.
Adewuyi
(2001)

29. Equipment

30. Scaled up-HyCator® Reactor

31. Conclusion
 Hydrodynamic cavitation is a new, advanced technology for the
decomposition of complex compounds and an alternative to
ultrasound-induced cavitation
 Hydrodynamic cavitation has the possible to become energy
efficient technique
 a very effective technique for the intensification of various chemical
and physical processes

32. REFERENCES
S.No
References
1 Dindar E,2016,An Overview of the Application of Hydrodinamic Cavitation for
the Intensification of Wastewater Treatment Applications,Innov Ener Res , Vol
5(1)
2. Krystel Li, Meng Wai Woo Improvement of rheological and functional
properties of Milk Protein Concentrate by hydrodynamic cavitation, Journal of
Food Engineering (2017)
3. Pandit AB, Joshi JB. Hydrolysis of fatty oils: effect of cavitation.
Chem Eng Sci 1993; 48: 3440–3442.
4. Patil MN, Pandit AB. Cavitation – a novel technique for making stable
nano-suspensions. Ultrason Sonochem 2007; 14: 519–530.

33. S.No
References
5 Pinjari DV, Pandit AB. Cavitation milling of natural cellulose to nanofibrils.
Ultrason Sonochem 2010; 17: 845–852.
6 Gogate PR. Application of cavitational reactors for water disinfection: current
status and path forward. J Environ Manage 2007; 85: 801–815.
8. Mohammadi V, Varnamkhasti MG, Ebrahimi R, Abbasvali M. Ultrasonic
techniques for the milk production industry. Measurement 2014; 58: 93–102.
9 Milly PJ, Toledo RT, Kerr WL, Armstead D. Inactivation of food spoilage
microorganisms by hydrodynamic cavitation to achieve pasteurization and
sterilization of fluid foods. J Food Sci 2007; 72: M414–M422.