A. THERMAL PROCESSING IN GENERAL Thermal processing implies application of thermal energy at suitable thermal potential, namely temperature to a reacting system. Thermal effects on chemicals, biochemicals and biological materials have long been recognised. Existence of these effects has been used to the advantages of many industries. Thermal activation of chemical reactions and biochemical reaction constitutes a very fundamental process in chemical and biochemical technology. Polymerisation reactions, hydrolysing reactions, oxidation and reduction reactions are few examples of many important processing reactions which may involve thermal processing. In active living tissue, many metabolic reactions can proceed appreciably at room temperature, causing undesirable alteration in the tissue. Low temperature storage has the basic objective of arresting the various reactions which may cause spoilage and which proceed at higher temperatures. With active proteins like enzymes and living tissue, denaturation and functional inactivation can occur rapidly at processing temperatures. Sterilization of microorganisms, pasteurisation of milk are specific examples of this type of thermal processing

Navankasattusas, Surapong

English

Massey Research Online

Copyright is owned by the Author of the thesis.  Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only.  The thesis may not be reproduced elsewhere without the permission of the Author.  A DEVELOPMENT OF AN ELECTRICAL ANALOGUE FOR THERMAL PROCESSING A thesis presented in partial fulfilment of the requirement for the degree MASTER OF TECHNOLOGY i n Biote chnology At Massey University Palmerston Nor th New Ze a land SURAPONG NAVANKASATTUSAS 1973 ACKNOWLEDGEMENTS The writer ~ish e s to express his gr a titude for the generous assist a nce a nd guida nce whic h h e rec e ived throughout this work, wit ho~ t whi ch t h i s study woul d h Rv e bee n i mpos s ible . The writer would lik0 to tha nk Professor R. L. Earle for his continua l teaching a nd guidanc e throughout this study" To Mr. R.E. He ndtl a s s , Ch emistry, Biochemistr y and Biophysics Depa rtme nt, whos e suggestions a n d contribution of th e e l e c t ric a l circuits is d e e ply appr e ci a t ed . Than~s a re al s o due to the sta ff of t he Food Sci e nce and Biotechnology Faculty, Ma ssey University, for their a i d . i TABLE OF CONTENTS I . SUMfvl ARY o •••••••••••• • • o Cl •••••••• • ••••• • o • •••••••• Page 1 II. I NTRODUCTION A. THERMAL PROCESSING IN GENERAL •••••••••••••••• 3 B. PROBLEM S I N FORM ULATING t.ND MANIPULATING PROCESSING CONDITION ......................... 4 C. THE OBJ ECTIVE OF THI S STUDY •••••••••••• • ••••• 5 III . LITERATURE SUR VEY A, KI NETICS OF THERNAL PROCESSING ............... 6 1 • Reacti o n Rate Equati on • ••••••••••••••• • 0 • 6 2 . Temperature Dependency of Reaction Ra t e Constant ••••••••• • • • • • • ••• ••••••• • •• 8 B. THERMAL PROCESSI NG EVALUATION • • • • • • • • • • . • • • • • 13 C, ANALOGUE SYSTEM FOR THERi,iAL PROCESSING • • • • • • • 15 IV . THEORY A, GENERATION OF REACTION RATE FOLLmJING THE ARRHENIUS EQUATION ···~············ ········· ·· 17 1. Thermistor Sensor o•W••········ ·········· · 17 2 . Gene r n tion of a Primary Re a c tion Ra te Following t he Arrheniu s Equat ion ... ........ 18 3. Mo difica tio n o f th e Primary Reaction Rate Constant •••••••••••••••••••••••••••• 19 B. I NTEGRATION OF THE GENERATED REACTION RATE 20 C-. CORRELt.TION OF ANALOGUE OUTPUT VOLTAGE v 0 WITH PROGRESS OF IEREVERSIBLE REACTION I N THERMAL PROCESSING ···~··••••••• ·••••• · ··~~~~·· 22 1. Irreversible Unimolecula r First-order Reac tions ·•·'• ·• ... • ........... ~ . .. .. . •. · -· . . . . • • 22 2. Irreversibl e Bimolecula r Second-order Reactions -. . ...... . .. -.. -. .... . ...... ... ,. ...... 24 3. Irreversible Trimolecular Third-order Reactions ... ... ... ~ .. -... . .. ..... . . . . .. .. .. . .. . . . . . . .. . . 27 ii 4. Irreversible Re a ction ~ith Empirical Rate Equ a tion of the n th Order 5 . The R8l~tionsht p of th e Rati o of Frequi::ncy li'ac to1· and the Rat io of Reaction Rate Constants at a Constant '.i.'emperature Page 30 31 V" AP:OARATUS B, REGUL~T~D FO~SR surPLY FOR THE ANALOGUE SYSTEM • ELECTRICAL A!'JALuGUl~ SYSTEJvi 1 . Primary R0action Ra t e Gene r ator . • ••.•.••• • . Analogue Mult i pli er Analogue Litegr:itor 33 33 33 34 C . THERhAL PROCESSING REACTOR • • •. , . . . • . . • • • . • • . • . • : 35 D. MEhSURING EQUIPMENT. . . .. .. ... ... .. ... . . .. . ..... 36 1 ,, v 01 t rn et e r () ,.., ti c 0 ( 0 0 0 0 t) ') • 0 & ... , " a 0 • " 0 0 0 0 0 0 • 0 0 0 • 0 36 2 . Potentiometer and ~hPrmocoupl e ••••••••••••• 36 3 . Potentiornet1·i.c Recorders • • • • • • . . • • • . • . • . • . • 36 VI . ?ROCEDURE VII. VIII., A. ARRANGD!ENT OF APPARATUS FOR EXP~RIMENTAL TESTING OF 'I'HE ANALOGUE SYSTEM • • • • • • • • • • • • • • • • • 4 3 B. DETERMINATION OF GENERATED PRIMARY REACTI ON "RATE v 1 A'l' V.1-\RIOU S TEMPERATURE T •• , • • • • • • • • • •• • 11-3 C. ~ETERMINATION OF GENERATED SECONDARY REACTI ON RA':::'E v 2 AT VARIOUS TEMPERP'I'URE T , • • • ••• • o . . c. .. 44 D. TESTI NG OF THE ANALOGUE INTEGRATOR. ...... . . . ... 44 E. APPLI CATION OF THE ELECTRICAL ANALOGUE IN THZRMhL PROCESSING O • ~ t'l" • ••• • • •oo:o o•• ,. • • • ••••••• RESULTS " • e 0 c 0 u • Q • 1 0 0 0 0 ,. " 0 0 ') 0 • (\ •••• 0 (t " e • .• " •••••••• 0 • 50 DISCUSSION OF RESULTS A 0 TES TI NG OF THE ANALOGUE SY STEM o • • •• , " • n • • • • • • • • 64 1. Generation of the Prima ry Reaction Rate v 1 . 64 2. Generation of the Reac t ion Rate v2 with Application of the Analogue Multipli er •••• • 64 j. The Analogue Integrator •••• • •• • •••••••••••• 65 iii B. THE ANALOGU E .SYSTEM I N THERMAL PROCESSI NG IX. CONCLUSIONS .., •• 0000000•.;••••••••••->••············· APP EI'ID IX . .................... ,, ......•...........•.. BI BLI OG RAP HY .......... ., •••• ~ ............... ., ••••••••• Page 67 88 90 10 1 iv Table VII . 1 Table VII.2 Tab le VII . 3 Table VII.4 Table VII . 5 Table VII . 6 Table VII . 7 Table VII . 8 Table VIII . 1 LIST OF TABLES Page Results of Prim a ry Reaction Ra te v 1 Generated by the Analogue •••• •• • •••.•• • 51 Results of Reaction Rate v2 Genera t ed by Lppl ic ation of Analogu e Multiplier (n=2) • • • . •• • •••. •••• • • •• • ••• 52 Results of Reaction Rate v2 Generated by Application of Analogue Multiplier (n=4) •e•••••••••••• o • • •• • ••• 53 Results of Reaction Rate v2 Generated by Application of hnalogue Multipli e r (n=6) •• •• •••••• • • • • •••• ••••• 54 Results of Reaction Rate v2 Generated by Application of Analogue Multipl i er (n=8) • n• • • • •••oo •• • • ••• •••• • 55 Results of Reaction Rate v2 Gener a ted by Applic a tion of hnalogue Multiplier (n=10) •• •• • • • •• •• • • • • •••••• • 56 Results of Reaction Rate v2 Generated by Application of Analogue Multiplier (n=12) •••••• • •••• •• • • • •••• •• 57 Results of Reaction Rate v2 Generated by Applic a tion of Analogue Multiplier (n=16) •• •••• • • •• •••• ••• • • •• • 58 Summary of Results in Reaction Rate Genera tion by the Analogue ••••••••••••• 70 v Table VIII . 2 Table VIII . 3 Tab l e VIII . 4 Table A. 1 Table A. 2 Table C.1 Measured Output Voltage Cha n ge s of Integr a tor a t Various I nput Voltages Compa riso n of Progr ess of th e The r mal St eril i za t i on De t e c ted by the Anal o gue a n d t hat by t he Temper a tu r e - time Page 71 Profi l e •• o••••••o•••••••o••• • • •o ••••••• 72 Compari son of Progress of th e Thermal Destructi o n o f the Chemical Species Detec ted by the Analogue and t ha t b y t he Temper a tur e -time Profil e Cha rac t er i sti cso f Copper -c onstant nn 73 Ther mocouple • • •••••••••••••• •• ••••••••• 9 1 Rel a tionship of Inve rs e Absol ute Tempe ra ture a t Hot Junction a nd Electric a l Pot enti n l of the Copper-c onst a ntan Thermo c oupl e 0 Cl •••••••••••••• Per tinent Va l ues Assoc i a t e d with Analys i s o f Exper i mental Reaction Ra tes Ge ner a ted 92 by the Analogue e•••••••• •· ·· ·· · · · ··· · · · 98 vi Figure V . 1 Fi gure V. 2 Figure V. 3 Fifjllre V . 4 Fi gu r e Vo5 Figu r e VI.1 Figure VII . 1 F i gure VII . 2 Figure VII . 3 Figur e VII . 4 LL3T OF FIGURES Circuit Diagran of the Voltage Regul~ted Power Supply ••• • ••• • •••• • • ..• Circuit Ding~am of the Primary Page 38 Reaction R~te v 1 Generator ~ ·····••••••• 39 Circuit Di ·tgram of an Analogue Multiplier. . .... .. . ........ . . .. . ... .... 40 Circuit Diagram of the Analogue Integrator • .. ,, .. . o..... . .... .. . .. . .. ... 41 Dingr am o f Wiring Through the Door of the Autoclave •n•• •• •·• • •••• •••• ••• •• 42 Ar r angement of Apparatus for Testing the Analogue •n•••• ·· ··· ········ · · ····· · 49 Results of 11nalogue Integrator Testing • •• :=» ••• ••• 0 . ... ...... ...... .. ... . Ou tput Voltage from the An~logue System in Following the Progress cf the Steriliza tion of a Microorganism Temperature and Time Profile in the Vicinity of the Sensor of the An~locue 59 60 in a Microbial Sterilization ........... 61 Output Voltage fr om the Ana logu e System in Following the Progress of the The rmal Destruction of the Chemical Spec ies •••••• • •••••••• •••••••• 62 vii Figure VIIo5 Figure VIII . 1 Figure VIII e2 Figure VIII .,3 Figure VIII . 4 Figure VIII o5 Figure VII . 6 Figure VIII.7 Figure VIII.8 Temperature and Time Profile in the Vicinity of the Sensor of the hnalogue in a Chemica l Destruction Reaction OO¥ o• • • e g ee o•oe ••• •• ••• •• •••••• • Plot of the Prima ry Rea ction Rate Generated by t h e Analogue According Page to the Arrhenius Equation (n=1) ~ · · ·· ···· 74 Plot of the Reaction Rate Generated by the Analogue According to the Arrhenius Equation (n=2) •••.•• • • • •.•• • • • 75 Plot of the Reaction Rate Genern ted by the Analogue hCcording to the Arrhenius Equa tion (n=4) ••. • • • • •• •••.•• • 76 Plot of the Reaction Rate Generated by the Analogue According to the Arrhenius Equa tion (n=6) • • • • ••••• •.• . .• •• •.••••••• 77 Plot of the ReA ction Rate Generated by the Analogue According to the Arrhenius Equation (n=8) • •. •• •. •• • .•••.••• •• • •••. • 78 Plot of the Reaction Rate Generated by the Analogue According to the Arrhenius Equ~tion (n=10) n•••• •··· · · ··· .... . ... .. 79 Plot of the Reaction Rate Generated by the Analogue According to the Arrhenius Equation (n=12) •o•••• • •••• • •••••••• • •• • • 80 Plot of the Reaction Rate Generated by the Analogue According to the Arrhenius Equation (n=16) ~ oonc~ • •••• •• •• •• •n•• • • • • 8 1 viii Figure VIII.9 Figure VIII e 10 Fi gure VIII . 11 Fi gure VIII. 12 Figure VIII.13 Figure VIII .14 Figure A~1 Figure A. 2 Relationship between Temperature Coefficient of Generated Re a ction Page Rate and Integer Multiple n •• •• • •• ••• ••• 82 Measur ed Output Voltage Changes of Integ r at or a t Va rious Input Voltage s ••••o••ti e ••oo • ., o• • •••• • ••• o ••••• 83 Reaction Ra te and Ti me Profile in the Vicinity of th e Sensor of the Analogue in a Thermal Sterilization 84 Progress of the Thermal Steril iza tion Detected by th e Analogue a nd th ~ t by Temperature a nd Time Measurem ent ••• • ••• • 85 Reaction Rnte and Time Profile in the Vicinity of the Sensor of the Analogue in a The r mal Destruction of a Chem ic a l Species f'l oo •••• t> • oo • .. • ••• • o•••••o,,•o•o •• • 86 Progr ess o f the The rm a l Destruction of th e Chemical Species De tect ed by th e Analogu e a nd tha t by Temperature a nd Time Me a surement '· •• • •• o. . ..... ... ... 87 Cha r a cteri s tics of Copper-constanta n The rmocouple • • ••••••• • •••• • ••• o• ••••• • • 93 Relationship of Inverse Absol ute Temper a tur e a t Hot J u nc t ion and El ec t ri c al Potential of the Copper-c ons tant an Therm oc ou pl e o e o • $ • • • • • • • • o • • 94 ix I. SUMMARY The objective of thi s study was to investiga te some genera l principles in thermal processing and some methods for following this processing experimenta lly. The emphasis of the investigat-ion wa s to develop a simple el e ctric a l a na logue system for follo winB th e progress of a single stage irre versible thermal processing re a ction. Documented data a nd principles of the kinetics of thermal processing of biological ma teri a l showed that such process reaction could be approxim a ted by the kinetic model of a single st a ge irreversible reaction. Temper a ture dependency of the thermal processing rate could also be approxim ~ted by the Arrhenius equation. Functional principles of electrica l analogue computers were appli e d to develop the electric a l analogue system. The structure and mode of operation of this syst em is described. The relationship between the output voltage of the analogue system and the progress of the therm a l processing are derived for different known thermal processing reactions, following the kinetic model of a single stage irreversibl e reaction. The performance of the electrical analogue system in this study was tested. The results indicated that the electrical analogue system so constructed could approximate the function described in theory. Non-ideality of the electrical circuitory, however, restricted the application of the electrical analogue system for its qualitative value only. The parameter governing 1 the t em p e r a ture dependence of an irreve rsible re a ction r a t e could be generated with e rror of approxi ma t e ly ~ 4.55%. The error a ssociat e d with a pplica tion of th e ~ nalogue integrator for integrating the ge nerat e d r eaction rate w&s a pproxim a tely ~ 7 . 25%. The overall e rror in a pplicat ion of the a na logue system for detecting th e rmal processing varied with the time span of proces s -ing cycl e 1 and processing effect achieved at temperatures other than the set temperature of processing . 2 

A development of an electrical analogue for thermal processing : a thesis presented in partial fulfillment of the requirements for the degree Master of Technology in Biochemistry at Massey University

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A development of an electrical analogue for thermal processing : a thesis presented in partial fulfillment of the requirements for the degree Master of Technology in Biochemistry at Massey University

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