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## Starch gelatinization in helicoidal reactor - influence of apparatuses geometry

### Piotr Sławomir Kurek

#### Abstract

Couette - Taylor flow reactor is composed of two coaxial cylinders, where the inner cylinder (rotor) rotates. The fluid flows in the annular gap between cylinders. The nature of the flow depends mainly on the apparatus geometry and the fluid properties. Laminar flow can be observed for a small value of rotor speed and is called Couette flow. When flow speed exceeds a certain critical value, stability is lost. At this point the centrifugal forces overcome the viscous forces and the Taylor vortices appear. The objective of presented here research was an analysis of the influence of apparatus geometry on the process of stretch gelatinization in Couette - Taylor flow apparatus. The apparatus geometry was adapted by modification of rotor geometry when the size and the shape of outer cylinder was kept constant. In the studies 3 types of rotor were used: • circular rotor with radius R1 = 0.016 [m], • circular rotor with radius R1 = 0.021 [m], • triangular rotor. In order to study the effect of rotor geometry on the process of gelatinization, following operating parameters were adopted:  thermostat temperature: 60 [° C], 65 [° C], 85 [° C];  rotational frequency: 5.78 [1 / s] and 19.27 [1 / s];  linear velocity along the reactor: ≈ 0,00033 [m/s] and ≈ 0,00098 [m/s]. The study was conducted by measuring degree of conversion and degree of swelling. To measure degree of conversion iodometric method has been used with spectrophotometer equipment. Additionally the apparent viscosity of gelatinization starch was measured assuming. Based on the test results the following conclusions can be set: a) The greatest value of gelatinization and swelling degree was always obtained for the circular rotor with a radius R1=0.021 [m]. Application of the circular rotor with a radius R1=0.016 [m] gave always the smallest gelatinization and swelling degree. b) For the circular rotor with radius 0.021 [m] and for triangular rotor at thermostat temperature equal to 65 [° C] and 85 [° C] (with the same values of other operating parameters) degree of gelatinization and degree of swelling were similar. Therefore, to increase productivity round rotor with radius R1=0.021 [m] can be replaced by a triangular rotor. c) The gruel obtained in the apparatus assembled with the triangular rotor and the large circular rotor had similar values of apparent viscosity. For smaller circular rotor values of the viscosity have been always much smaller. d) The values of starch gelatinization and swelling degrees, as well as, apparent viscosity of gelatinized starch were mostly affected by axial velocity and the thermostat temperature. The rotor rotation effect can be observed only for the small rotor (R1=0.016[m]) when the gap size was the biggest. In case of other studied apparatus geometries the influence of the rotor rotation on the properties of gelatinized starch seems to be negligible.
Record ID
WUTd3bc536e5cd04d7c85792ac4813bbc3c
Diploma type
Master of Science
Author
Piotr Sławomir Kurek (FCPE) Piotr Sławomir Kurek,, Faculty of Chemical and Process Engineering (FCPE)
Title in Polish
Kleikowanie skrobi w reaktorze z przepływem helikoidalnym - wpływ geometrii aparatu
Supervisor
Robert Hubacz (FCPE/DPKT) Robert Hubacz,, Department of Process Kinetics and Thermodynamics (FCPE/DPKT)Faculty of Chemical and Process Engineering (FCPE)
Certifying unit
Faculty of Chemical and Process Engineering (FCPE)
Affiliation unit
Department of Process Kinetics and Thermodynamics (FCPE/DPKT)
Study subject / specialization
, Inżynieria Chemiczna i Procesowa
Language
(pl) Polish
Status
Finished
Defense Date
17-01-2012
Issue date (year)
2012
Pages
66
Internal identifier
DICHP-2063
Reviewers
Antoni Rożeń (FCPE/DCRED) Antoni Rożeń,, Department of Chemical Reactor Engineering and Dynamics (FCPE/DCRED)Faculty of Chemical and Process Engineering (FCPE) Robert Hubacz (FCPE/DPKT) Robert Hubacz,, Department of Process Kinetics and Thermodynamics (FCPE/DPKT)Faculty of Chemical and Process Engineering (FCPE)
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
File
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Piotr_Kurek.pdf
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Identyfikator pracy APD: 2909

Uniform Resource Identifier
https://repo.pw.edu.pl/info/master/WUTd3bc536e5cd04d7c85792ac4813bbc3c/
URN
urn:pw-repo:WUTd3bc536e5cd04d7c85792ac4813bbc3c

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