Dinamika strujanja tečnosti i čestica u reaktorima sa oscilatornim tokom i primena na biohemijsku reakciju uz upotrebu imobilisanih enzima
Dynamics of liquid and solids flow in oscillatory flow reactors and application to biochemical reaction with immobilized enzymes
Author
Slavnić, Danijela S.Mentor
Nikačević, NikolaCommittee members
Bezbradica, DejanBugarski, Branko
Đuriš, Mihal
Metadata
Show full item recordAbstract
Disertacija obuhvata eksperimentalno i teorijsko istraţivanje osnovnih fluido –
dinamiĉkih karakteristika kontinualnih jednofaznih i višefaznih reaktora sa oscilatornim
tokom fluida (ROT). Pored ispitivanja dinamike strujanja teĉnosti i ĉestica, u okviru ove
teze ispitivana je i mogućnost primene ROT na reakciju sinteze galaktooligosaharida
(GOS) pomoću slobodnih i imobilisanih enzima.
U prvom poglavlju dat je detaljan pregled dosadašnjih istraţivanja koja se
odnose na reaktore sa oscilatornim tokom fluida. Prikazane su karakteristike, prednosti i
nedostaci ROT predstavljeni u literaturi. Posebno su prikazani i rezultati istraţivanja
potencijalne industrijske primene ovog tipa ureĊaja.
U drugom poglavlju „Dinamika strujanja teĉnosti u ROT“ prikazani su rezultati
eksperimentalnog ispitivanja strujanja, tj. raspodele starosti teĉnosti na izlazu, u dva
geometrijski sliĉna reaktora sa oscilatornim tokom fluida duţine 2 m i unutrašnjeg
preĉnika 44 i 26 mm. Primenjena je metoda praćenja odzi...va sistema na impulsnu
promenu obeleţene supstance ĉija koncentracija je merena u vremenu pomoću
spektrofotometra. Na osnovu eksperimentalnih rezultata utvrĊen je uticaj operativnih
parametara (frekvencija, amplituda i protok peristaltiĉke pumpe) na raspodelu starosti
teĉnosti na izlazu iz ispitivanih reaktora sa oscilatornim tokom fluida. Primenom
modela klipnog strujanja sa aksijalnom disperzijom, a na osnovu eksperimentalnih
rezultata razvijena je matematiĉka korelacija koja povezuje bezdimenzioni Pekleov broj
sa bezdimenzionim brojevima koji opisuju oscilatorni tok teĉnosti u reaktorima:
oscilatorni Rejnoldsov broj, Strauhalov broj i odnos oscilatornog i Rejnoldsovog broja
neto protoka. Razvijena korelacija je pored eksperimentalnih vrednosti ove disertacije
verifikovana i uz pomoć eksperimentalnih rezultata dostupnih u literaturi.
U trećem poglavlju „Dinamika strujanja ĉestica“ prikazani su rezultati
eksperimentalnog i teorijskog istraţivanja naĉina proticanja ĉestica u kontinualnom
reaktoru sa oscilatornim tokom fluida (unutrašnjeg preĉnika 26 mm) u koji se ĉestice
uvode kontinualno. Primenom metode praćenja odziva sistema na stepenastu promenu
obeleţenih ĉestica utvrĊen je uticaj operativnih parametara – frekvencije, amplitude ikoncentracije ĉestica na ulazu u reaktor, na kumulativnu krivu vremena zadrţavanja
ĉestica u reaktoru. Kako bi se odredila koncentracija obeleţenih (obojenih) ĉestica,
fotografije uzoraka su analizirane u programskom paketu ImageJ. Pored toga, ispitan je
i kvantifikovan uticaj operativnih parametara na naĉin proticanja ĉestica i stešnjeno
taloţenje, srednje vreme zadrţavanja kao i na udeo (zadrţanih) ĉestica u reaktoru.
Teorijski i eksperimentalno su utvrĊeni kriterijumi za odreĊivanje 4 reţima proticanja
ĉestica: puzajući reţim strujanja ĉestica, zgušnjeno strujanje ĉestica, razblaţeni tok
ĉestica i odnošenje ĉestica...
The dissertation presents experimental and theoretical investigation of the main
fluid dynamic characteristics of continuous single – phase and multiphase fluid flow in
continuous oscillatory flow reactors (COFR). In addition, the possibility of COFR
application to reaction of galactooligosaccharides (GOS) synthesis with free – flow and
immobilized enzymes was studied within this thesis.
The first chapter provides a detailed overview of the research related to
oscillatory flow reactors (OFR). Further, the characteristics, advantages and
disadvantages of OFR presented in the literature are discussed. In addition, the
possibilities of industrial application for this type of device are presented.
In the second chapter "Dynamics of fluid flow in the OFR", the results of
experimental investigation of the liquid residence time distribution (RTD) in two
geometrically similar reactors with oscillatory flow of liquid are presented.. Reactors
were 2 m in length and with internal diameter of 44 a...nd 26 mm. The impulse response
method with a tracer was applied. The concentration of the tracer in the samples was
determined by measuring the absorbance using a spectrophotometer. The influence of
operating parameters (frequency, amplitude and flow rate of the peristaltic pump) on the
RTD in the reactors was determined. Using a plug flow with axial dispersion model and
experimental results, an empirical correlation was derived. Developed correlation
relates the dimensionless Peclet number to dimensionless numbers describing the
oscillatory fluid flow in the reactors: oscillatory Reynolds number, Strauhal number and
ratio of oscillatory and net Reynolds number. In addition to the experimental results of
this dissertation, the correlation was verified using experimental results from the
literature.
The third chapter "Dynamics of solids flow in the OFR" presents the results of
experimental and theoretical investigation of the liquid – solids flow in continuous
oscillatory flow reactor (internal diameter of 26 mm) into which the solids are
introduced continuously. The influence of operating parameters – frequency, amplitude
and concentration of solids at the inlet of the reactor, on solids cumulative residencetime curve (F) in the reactor was determined using the step response method with a
tracer (solids of a different color). In order to determine concentration of tracer, the
photos of samples were analysed using the ImageJ software. In addition, the influence
of operating parameters on the solids flow regime, hindered particle settling, mean
residence time as well as solids holdup in the reactor was examined and quantified. Four
solids flow regimes were identified theoretically and experimentally: creeping solids
flow, dense solids flow, dilute solids flow and solids washout...