INDUSTRIAL AND ENGINEERING CHEMISTRY
January, 1926
serious. For this reason the process of evaporation is carried on in shallow, open-top pans out in the open except for shed roof protection. Possible explosions due to the presence of carbonaceous materials are most likely to occur in the evaporating process, as this is the first exposure to relatively high temperatures. When preparing a product from chemically controlled ammonia liquor and using acid that is known to be free from nitro bodies, there should be no cause for serious accidents. However, when the reverse condition is true i t is better to cease operations until the ingredients can be brought up to a proper standard. If i t is desired to rework material that might contain foreign carbonaceous materials,. great care and forethought must be exercised. If the foreign material is such that a positive separation can be made by dissolving in water and decanting or skimming, this should be done in special apparatus installed for the purpose. The resultant liquor should then be sampled and analyzed a t the laboratory before it is introduced into the evaporating pans.
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During the process of evaporation most of the carbonaceous materials present form in a scum on top of the charge and can to some extent be removed by skimming-that is, if any have been allowed to get that far in the process. If any should remain and reach the steam coils as the charge is drawn down, the greatest point of possible danger is reached. It is therefore important that the steam be shut off prior to the drawing down operation and that a bleeder valve be opened to insure against high temperatures a t the coils due to leakage past the valves. Temperature control throughout the process is important and, to enable this, easily read dial type or recording thermometers should be provided at each evaporating pan and their accuracy checked from time to time. It is ordinarily a wise precaution to carry on such processes in buildings well isolated from other structures and to provide barricade protection around the evaporating pans in order that the minimum of damage will be done if a t any time extraordinary conditions should occur in the process.
Characteristics of Fish and Allied Oils‘ By A. R. Lange SWAN-FINCE OIL CORP.,New YORK,N. Y.
HE tests submitted are an average of a season’s production. They should not be interpreted as literal specifications, as they vary to some extent. However, they are dependable indexes of average results. The colors quoted are color equivalents as recorded on the Kational Petroleum Association colorimeter for mineral oils. The flash and fire tests are taken by the A.S.T.M. method in the Cleveland open cup with a thermometer scaled for one-inch immersion. The viscosities are taken with the Saybolt Universal viscometer. The cloud test (first indication of cloudiness) and the cold test (solid point) are taken with A. S. T. M. apparatus. The free fatty acid is calculated to per cent oleic acid. The iodine number is taken according to the Wijs method with a saturation period of 1 hour and 1.5 minutes. Extensive tests run in the author’s laboratory indicate that the
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Received October 1. 1925.
Hanus method when run for 30 minutes’ saturation will give results approximately ten points lower when the iodine Wijs is 180 per cent. In other words, 180 iodine number according to Wijs will run approximately 170 Hanus method for 30 minutes. Frequent attempts have been made to determine the reason for the fluctuation of the iodine number of fish oils, so far with no real success, although the universal demand for a high drying oil would welcome such information. As a rule fish oils made from fish caught in northern waters yield less stearin than oils made from southern-water fish. But both northern and southern fish oils are met with varying iodine numbers. I n these tests crude menhaden oil is first separated into winter-pressed menhaden oil and soft foots or soft stearin. These soft foots are further processed to remove more oil and a dry hard cake, called “hard foots” or “fish stearin,” remains. The bleaching is carried on by fuller’s earth filtration, or by an alkali treatment when a low acid product is desired.
P h y s i c a l a n d C h e m i c a l C h a r a c t e r i s t i c s on a S e a s o n ’ s P r o d u c t i o n of F i s h a n d Allied Oils F. F. A. Be. Cloud Cold as Color gravity Sp. gr. Lbs./gal. Flash Fire Viscosity test test oleic Sapon. Titer PRODUCT N. P. A. a t 6 0 ° F . a t 6 0 ° F . at 60 F. OF. F. 10OOF. 210’F. F. F. % No. ’ F. 36 2.49 192.0 Crude menhaden (low acid) 33/4 20.6 0.9296 49 53 7 . 7 4 2 515 630 127 Winter-pressed menhaden 197.0 4 20.4 50 30 24 3.58 0.9309 7.752 520 635 129 24 3.21 196.0 Yellow bleached menhaden fishoil 3I/z 20.2 0.9321 7 . 7 6 2 520 50 38 640 137.5 196.5 White bleached menhaden fish oil 21/* 20.1 0.9327 51 40 24 3.05 7.767 530 645 141 Menhaden soft foots 196.0 ... 20.8 0.9234 7.731 ... 70 2.84 Hard unbleached foots (menhaden) .. 21.7 0.9229 7.685 445 620 1.94 200.2 96 Hard bleached foots (menhaden)O 21/r 21.7 0.9929 7.685 .. . . _ . N o n e 2 04.5 101 . .. -. .. .. .. ... . . . . .. Newfoundland cod oii 6’21.1 0.9iS5 14 11.55 iss.0 7.716 460 530 150 50 26 Whale oil 5.56 194.0 41/4 20.9 40 0.9278 22 7 . 7 2 6 480 590 156 53.5 Herring oil 2.30 186.5 2’/a 21.0 36 0.9279 32 7.729 Crude sardine oil 0.66 197.5 31/4 20.5 50 0.9302 32 50 7.747 595 660 149 Refined sardine oil 0.88 194.5 3’/r 20.3 32 0.9315 26 7 . 7 5 7 595 665 150 50 Light oxidized fish oil 5 . 0 3 208.0 0.9929 5I/a 11.0 38 8.269 530 600 199 Heavy oxidized fish oil Dk.Red 10.63 4.54 212.8 25 0.9950 8.291 470 690 1012 Analysis of Fish Sfeorin Glycerides Unsaponifiable by difF. F. F. A. % % % Hard bleached footso 1.00 99 .oo Hard unbleached foots 3.06 95.00 1:94 Soft unbleached foots 2.30 94.86 2.84 Hard bleached foots shpw no free acid as they were bleached with caustic soda; they would show some if earth instead of alkali had been used particular batch.
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Iodine No. Wijs 187 187.5 188.5 189.0 163.4 118.2 101.5 173.0 152.0 143.0 178.5 184.2 116.0 106.3
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