Measuring and modelling of residence time distributions in mixer-settler reactors
Sipilä, Valtteri (2022)
Diplomityö
Sipilä, Valtteri
2022
School of Engineering Science, Kemiantekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2022121270604
https://urn.fi/URN:NBN:fi-fe2022121270604
Tiivistelmä
Process optimization through residence time distribution provides impactful information about flow mechanics inside of a reactor without heavy computational modelling. Mixer-settler, containing a stirred tank reactor and two phases would lead to an incredibly complex system computationally, and information this detailed is often unnecessary. Therefore mixer-settler performance through hydrodynamics can be analysed from a pilot scale model by calculating residence time distribution using tracer tests, as was done in this Thesis.
Previous studies on the same topic conducted on mixer-settler systems are scarce and they have not been conducted in a scale this small, but aqueous phase residence time distributions were formed through conductivity measurements over time. No studies were found that analysed organic phase residence time distribution (RTD) from a mixer settler system, and best method to measure organic phase RTD is by using radioactive tracers.
Aqueous phase tracer tests were carefully planned out, and pulse tests experimented with various volume flows. Exit time curves were successfully formed that were used to estimate performance of the reactor and to fit ideal and nonideal models that would describe the data.
Operating conditions were found where mixer closely followed a model of an ideal CSTR, while phases still completely separate at settler side. Prosessin optimointi viipymäaikajakauman kautta antaa hyödyllistä tietoa reaktorin sisäisistä virtauksista ilman monimutkaista laskennallista mallintamista. Mixer-settler, joka sisältää sekoitussäiliöreaktorin ja kaksi faasia, johtaisi laskennallisesti kohtuuttoman monimutkaiseen järjestelmään, ja näin yksityiskohtaiset tiedot ovat usein tarpeettomia. Siksi mixer-settlerin suorituskykyä voidaan analysoida hydrodynamiikan avulla pilottimallin avulla laskemalla viipymäaikajakauma merkkiainekokeiden avulla, kuten tässä opinnäytetyössä tehtiin.
Aiempia samasta aiheesta tehtyjä mixer-settler-järjestelmiä koskevia tutkimuksia on vähän, eikä niitä ole tehty näin pienessä mittakaavassa, mutta vesifaasin viipymäaikajakaumat muodostettiin johtokykymittauksilla avulla ajan kuluessa. Aiempia tutkimuksia, joissa analysoidaan orgaanisen faasin viipymäaikajakaumaa sekoitin erottaja järjestelmästä ei löytynyt, ja paras menetelmä orgaanisen faasin viipymäaikajakauman mittaamiseen olisi radioaktiivisten merkkiaineiden käyttö.
Previous studies on the same topic conducted on mixer-settler systems are scarce and they have not been conducted in a scale this small, but aqueous phase residence time distributions were formed through conductivity measurements over time. No studies were found that analysed organic phase residence time distribution (RTD) from a mixer settler system, and best method to measure organic phase RTD is by using radioactive tracers.
Aqueous phase tracer tests were carefully planned out, and pulse tests experimented with various volume flows. Exit time curves were successfully formed that were used to estimate performance of the reactor and to fit ideal and nonideal models that would describe the data.
Operating conditions were found where mixer closely followed a model of an ideal CSTR, while phases still completely separate at settler side.
Aiempia samasta aiheesta tehtyjä mixer-settler-järjestelmiä koskevia tutkimuksia on vähän, eikä niitä ole tehty näin pienessä mittakaavassa, mutta vesifaasin viipymäaikajakaumat muodostettiin johtokykymittauksilla avulla ajan kuluessa. Aiempia tutkimuksia, joissa analysoidaan orgaanisen faasin viipymäaikajakaumaa sekoitin erottaja järjestelmästä ei löytynyt, ja paras menetelmä orgaanisen faasin viipymäaikajakauman mittaamiseen olisi radioaktiivisten merkkiaineiden käyttö.