CANNING SARDINES 201 
TABLE 37.—Effect of change in air temperature upon the drying rate of raw and 
steamed California pilchards—Continued 
STEAMED FISH 



Vapor Per cent loss in weight (time in minutes) 
pressure | Temper- Ss ee eet ate 
Experiment No. tn Tones oe 
of mer- : 
cury 10 15 20 30 60 120 
(NEC pence ee eS 0. 45 OOh Boe eaasa 2 G58) | seen tone 9.5 LS: OH|.2 ses a 
TIN WP) teres = renee em eee a . 60 LOO} Besse sass. (AUG eee eee 9.3 SPAY fl ee See 
MiG eee ee As 1.10 120 REE ae kor ss 830: |Ea eens LG ACR Ee el eee 
Ite ee ee Te Pe . 62 I Se) ER Sees el Pee ene eerie Sere 14.5 UC a eee ee 
UIST et a oe Set 45 03; Paces tee Ein eee 9.8 TSNON | Saas see 
11013) 0) = ee en ee 1.10 120 | Sekece ieee S45) leo = 2 EES NZ 1653) ooo ees 
NBenC sot Aea eth e4 2. 44 166) buen 2 93:0) |2sSh 22 12.8 D(e2ia) see ae 
1G eae a 44 O2h Ih ones ON Seo ee oes 12.3 ay oy eee eee 
nly G5) oe Cage Soe eee 74 D102| Sic 3 el eset LON | 22 aot sees 13.7 bo a ers 
1 ee oe 1, 29 De eee eee Ue ee ee ae 12, 2 WG, 4 | eos oe 








Effect of change in air velocity upon the drying rate of raw and steamed fish.— Data 
indicating the nature of the change in the drying rate of the fish, due to increased 
air velocity, are givenin Table 38. It will be seen that increasing the air velocity 
brings about only a small increase in the moisture loss. Lewis, and also Carrier, 
in the Journal of Industrial and Engineering Chemistry (see footnote, p. 120), 
show that where the rate of diffusion of moisture within an object, to the surface, 
is slow increased air velocity has little effect in increasing moisture removal other 
than that increase that is brought about by greater heat transfer from the air 
to the object at the higher velocity. This undoubtedly explains the experimental 
results. 
Change in drying rate of raw and steamed fish with respect to iime.—In Table 39 
an analysis is made of the data from various experiments, indicating the nature 
of the change in the drying rate with respect to time. It will be seen that the 
rate of moisture removal at first is relatively rapid, after which it slows down to a 
more or less uniform rate. This, of course, covers only the range of time investi- 
gated. During the first interval of time the free moisture on the surface of the 
fish and the most accessible combined moisture is removed. Following this 
the only water removed is that which reaches the surface by the relatively slow 
process of diffusion. 
TABLE 38.—Effect of change in air velocity wpon the drying rate of raw California 






pilchards 
L Per cent loss in weight : Per cent loss in weight 
: Velocity (time in minutes) : Velocity (time in minutes) 
Experiment in feet Experiment in feet 
number per a number per 
minute 30 60 90 minute 30 60 90 
a CU eee 8 Paid Berean Les Se 638 5.9 9.1 11.6 
Li ee ADO NE mF. a QAP es oe ae WM CLS ee Ree 2 952 5.3 8.3 10.7 
ies ee 6674 2=Sase 409) Bete es LS eee ean 575 6.1 CA ae 
Ot) ae 308 4.2 eh aoe LISc== ewe e~ : 575 6.1 Oy 2alcat eee 
GCs eo ee 656 5.5 OF OM Esse PL Semeseew Ser 968 6.7 11 sg ee 
Ga nes eel oe 1,075 6.5 LON 2a. == 2% nik %s eee eee 968 6.7 LORS ial a ae ee 
Lit oa ee ee 255 4.1 6.7 9.0 





