Prediction of batch heat transfer coefficients for pseudoplastic fluids ...
Prediction of batch heat transfer coefficients for pseudoplastic fluids ... Prediction of batch heat transfer coefficients for pseudoplastic fluids ...
72 (3-77 Substituting these terms in equations 3-75 ru~d 3-73 ~nd placing the Prandtl number in the nu..merator, as for Ne1oJtonian (3-78 or C YRe" -;;;;;; -; A?~ (~- ( ~ nv K"J1I Dei ( / -2~ I- cZ ) / K) J? /[J ) C d (3-79 Equation 3-79 then characterizes heat transfer to pmver law fluids being agitated by geometrically similar marine propellers. This characterization is based on a model which is believed to represent the flo1.J patterns fairly accurately. If the impeller geometry changes; that is, if the vertical "VJill increase and thus a higher Nusselt number will result. Equation 3-79 may be expanded to correct for geometrically unsimilar impellers by adding a sixth di!l1ensionless term, WalDa' where \-1 a is the impeller 1rddth .. AI. - c NJ~:;: f~/" iI.(f)i~V CjNjci e AI U - Re /Vp-1. K'w (Ii (;;- -1V (3-80 at Other geometry effects could be taken into account by adding more dimensionless groups such as found in the dimensional analysis for Newtonian fluids as presented in equation 2-35. 4i
73 Semi-Empirical Correlation i .., .. ' in Metzner has show~ that the shear rate in an agitated vessel is related to the agitation rate of the bnpeller v a = (11 .. 5 N) (2-20 as discussed in Chapter 2 and thus the apparent viscosity could be defined. (2-25 It was felt that using this apparent viscosity in place of the Nelvtonian viscosity in the Reynolds and Prandtl ntunbers of the l'lfeHtonian fluid correlation would yield a correlation suitable fol'" power-law fluids.. The Reynolds and Prandtl nurabers evaluated using this apparent viscosity are designated as NR~ and Np~ respectively_ The correlation Has expressed as (3-81
- Page 33 and 34: 21 complicated by a variable viscos
- Page 35 and 36: 2J Schultz-GrQnow (174) used a dime
- Page 37 and 38: 2S The results shm-red that equatio
- Page 39 and 40: Su.bstituti011 of equati 2-22 gives
- Page 41 and 42: 29 In both Newtonian and non-Newton
- Page 43 and 44: 31 for viscous pseudoplas tics at 1
- Page 45 and 46: 33 (2-29 when both the distances ar
- Page 47 and 48: JS Thermometers or thermocouples ar
- Page 49 and 50: .37 2: a in in heat cQ@tent of the
- Page 51 and 52: J9 cooling mediu..:m side, the heat
- Page 53 and 54: 41 ports a value of 3/4-.. He then
- Page 55 and 56: 43 find the effects of one or two o
- Page 57 and 58: 45 The group to the left of the equ
- Page 59 and 60: 47 the highest heat tra...nsfer coe
- Page 61 and 62: 49 A pitched blade turbine gave coe
- Page 63 and 64: SI done on the correlation of heat
- Page 65 and 66: 5J evaluated at the wall temperatur
- Page 67 and 68: ss to (2-46 where ill is the consis
- Page 69 and 70: CHAPTER .2 DEVELOPMENT OF CORRELATI
- Page 71 and 72: momentum" mass" and energy may be ~
- Page 73 and 74: 61 Vr;> Jt.- ,,"Ii'\... ..", ::: (V
- Page 75 and 76: 63 Substitution of these dimensionl
- Page 77 and 78: l/(R + 1) and was able t@ elim.iE.a
- Page 79 and 80: 67 All of the variables and differe
- Page 81 and 82: 69 The average heat transfer coeffi
- Page 83: N"v = C Iv''' (;';~-"')&'i'~ (%t-n,
- Page 87 and 88: 75 7I1C1?/lfOCOUPLc .JuNe T/ON IMBE
- Page 89 and 90: 77 _I"---- / SCALE I ~~, .5 j t /Z.
- Page 91 and 92: also cop~ected to the pipes leading
- Page 93 and 94: 81 Ve8sel :J all th:l c]me 8 8 .) '
- Page 95 and 96: 83 potentiometer for varing the mot
- Page 97 and 98: 85 MATERIAL 7:0 STAIIJLESS STEEL /
- Page 99 and 100: 11 Wa.ll (Mi€1dl~) Same as #5 81
- Page 101 and 102: 89 shea.r ra.tes, tl?1ey a.re unaff
- Page 103: and if' lO"V'l$' a sm.all amount of
- Page 106 and 107: 94- was about 40-45 ndmutes .. Tke
- Page 108 and 109: 96 vThere N is in rev./sec .. and S
- Page 110 and 111: 88 ql\fETI A = 6 T \--T -s L/kw (1+
- Page 112 and 113: I {)D The generalized Reynolds n~mb
- Page 114 and 115: 02. CHAPTER !2. RESUI,TS Many heat
- Page 116 and 117: 01 TABLE 5-2 sutn~U{Y OF ADDITIONAL
- Page 118 and 119: 108 the batch than the other ticJO
- Page 120 and 121: 108 optimum impeller heights were u
- Page 122 and 123: 10 I r "'" , •• ,'., "",' """",
- Page 124 and 125: 112 correlations for the prediction
- Page 126 and 127: TABLE 5 - 4 Correlation Constants A
- Page 128 and 129: 1/6 Table 5-5 and 5-6. A measure of
- Page 130 and 131: TABLE S - 6 IMPELLER Correlation Co
- Page 132 and 133: 120 greater than 2.0. In this case
73<br />
Semi-Empirical Correlation<br />
i .., .. ' in<br />
Metzner has show~<br />
that the shear rate in an agitated<br />
vessel is related to the agitation rate <strong>of</strong> the bnpeller<br />
v a =<br />
(11 .. 5 N) (2-20<br />
as discussed in Chapter 2 and thus the apparent viscosity<br />
could be defined.<br />
(2-25<br />
It was felt that using this apparent viscosity in place <strong>of</strong><br />
the Nelvtonian viscosity in the Reynolds and Prandtl ntunbers<br />
<strong>of</strong> the l'lfeHtonian fluid correlation would yield a correlation<br />
suitable fol'" power-law <strong>fluids</strong>..<br />
The Reynolds and Prandtl<br />
nurabers evaluated using this apparent viscosity are designated<br />
as NR~ and Np~ respectively_ The correlation Has<br />
expressed as<br />
(3-81
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