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 ...
108 optimum impeller heights were used in all the subsequent 1.Jork; hO'IJ.!6ver, '.Ihen the more viscous fluids ,.rere in the vessel the wall temperature differences could not be eliminated .. Impeller fIeight In addition to af:fecting the uniformity of \-1all tem£) ex'ature, the impeller height also influenced the heat trans:fer rate. In general, the greater the impeller distance from the vessel bottom" the greater the heat trans:fer rate (1r-Jithin the limits tested, up to 1/2 the vessel height) .. This phenomenon is pl""obably closely related to the large wall temperature variations which are present Hhen the Lmpeller is very close to the bottom of the vessel, (ie. as the impeller is raised, the agitation of the batch is more uni:form and thus the wall temperature variations are reduced and the heat transfer rates increased). Since the amount of data measuring these effects is limited the results are only qualitative. They are shown graphically for the anchor, propeller" and turbine in Figures 5-1, 2 and 3. As can be seen on these curves, a two inch vertical displacement of the impeller changes the heat transfer coefficient by almost ten percent .. There 1.
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- 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 and 84: N"v = C Iv''' (;';~-"')&'i'~ (%t-n,
- Page 85 and 86: 73 Semi-Empirical Correlation i ..,
- 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 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
- Page 134 and 135: 12.2
- Page 136 and 137: TABLE 5 - 9 CORRELATION E t (a/n +1
- Page 138 and 139: TABLE 5 - 10 IMPELLER Correlation C
- Page 140 and 141: TABLE 5 - 11 CORRELATION G (1.30/61
- Page 142 and 143: 1.30 of the substantial improvement
- Page 144 and 145: 1.3 2. The probable error in the ca
- Page 146 and 147: 134 .,;' : :: :::: : ~ !~. , " . .'
- Page 148 and 149: T." ••••••• ,_ .....
- Page 150 and 151: 38 the cooling of nitration liquors
- Page 152 and 153: 140 The average deviation of the me
- Page 154 and 155: 42 tween 0.25 and 0.58. L~~l had re
- Page 156 and 157: 144 transfer coefficients to non-Ne
- Page 158 and 159: 16 of fit and it may t...herefore b
- Page 160 and 161: 148 'tvas insufficient data to eval
- Page 162 and 163: 50 A ::: Apr ... B ::: C p ::: CPr
- Page 164 and 165: 52. Q ::. Average heat transfer rat
- Page 166 and 167: Xc = Function of Reynolds nL:l.m.be
- Page 168 and 169: IS6 G REE:>{ ALPHABET 0 ::: Value o
108<br />
optimum impeller heights were used in all the subsequent<br />
1.Jork; hO'IJ.!6ver, '.Ihen the more viscous <strong>fluids</strong> ,.rere in the<br />
vessel the wall temperature differences could not be<br />
eliminated ..<br />
Impeller fIeight<br />
In addition to af:fecting the uni<strong>for</strong>mity <strong>of</strong> \-1all tem£)<br />
ex'ature, the impeller height also influenced the <strong>heat</strong><br />
trans:fer rate. In general, the greater the impeller distance<br />
from the vessel bottom" the greater the <strong>heat</strong> trans:fer rate<br />
(1r-Jithin the limits tested, up to 1/2 the vessel height) ..<br />
This phenomenon is pl""obably closely related to the large<br />
wall temperature variations which are present Hhen the<br />
Lmpeller is very close to the bottom <strong>of</strong> the vessel, (ie. as<br />
the impeller is raised, the agitation <strong>of</strong> the <strong>batch</strong> is more<br />
uni:<strong>for</strong>m and thus the wall temperature variations are reduced<br />
and the <strong>heat</strong> <strong>transfer</strong> rates increased).<br />
Since the amount <strong>of</strong> data measuring these effects is<br />
limited the results are only qualitative. They are shown<br />
graphically <strong>for</strong> the anchor, propeller" and turbine in<br />
Figures 5-1, 2 and 3.<br />
As can be seen on these curves, a<br />
two inch vertical displacement <strong>of</strong> the impeller changes the<br />
<strong>heat</strong> <strong>transfer</strong> coefficient by almost ten percent ..<br />
There 1.