US1829571A - Production of cod-liver oil - Google Patents

Description

Oct, 27, 1931. F. w. NITARDY PRODUCTION OF GOD LIVER OIL Filed March 30, 1926 3 Sheets-Sheet l CONDENSER I STEAM LINE CENTRIFUGAL 2 INVENTOR E 920M 0- Z;

I BY

ATTORNEYS 0d. 27, 1931. w, n- 1,829,571

PRODUCTION OF GOD LIVER OIL Filed Mafch 50, 1926 s Sheets-Sheet 2 SUPPL 5m VACUUM TANK JETTLING TANKS CENTRIFUGAL INVENTOR ?&W 41-1 BY W 9 m; M AIM ATTORNEYS Oct. 27, 1931.

F. W. NITARDY PRODUCTION OF GOD LIVER OIL Filed March 30, 1926 3 Sheets-Sheet 3 INVENTOR ATTORNEYS Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE FERDINAND W. NITARDY, OF BROOKLYN, NEW YORK, ASSIGNOR TO E. R. SQUIBB AND SONS, OF NEW YORK, N. Y A CORPORATION OF NEW YORK PRODUCTION OF COD-LIVER OIL.

Application filed March 30, 1926.

This invention relates to the rendering of cod-liver oil and particularly to a method of producing an improved cod-liver oil which is especially adapted for medicinal use.

Cod-liver oil has been produced heretofore by cooking the whole livers with steam. The oil separates in a layer above the solid material resulting from the cooking operation when the mixture is permitted to cool and it can be withdrawn therefrom. The separation is not complete and much ofthe oil is lost. The oil recovered by the simple cooking operation, if no special precautions are taken, is of relatively poor quality and is subject to rapid deterioration particularly with respect to. the development of a disagreeable odor and taste. It is usually permitted to contact with the atmosphere with the result that oxygen is absorbed. The

oxygen attacks the vitamin content of the oil and reduces the amount of this important factor to a considerable extent. Much of the therapeutic value of the oil is thereby lost.

I have discovered, furthermore, that codliver oil absorbs or dissolves a certain amount of water and that the water contains albuminous material which is derived from the livers. The absorbed water and the albuminous material appear to have a deteriorating effect upon the oil so that the most carefully rendered oil develops an odorand taste if it is permitted to retain the normal moisture content. The oil, which when freshly rendered is comparatively odorless and tasteless, becomes thus unsuitable or at least unsatisfactory for human consumption after a relatively short time.

It is the object of the present invention to provide a method of rendering cod-liver oil which ensures maximum recovery of the oil and protects it at the same time against deteriorating influences from the first separation of the oil to the ultimate packaging thereof,

Another object of the invention is to prevent deterioration of the oil by reason of the unavoidable presence of materials therein which'are derived from the livers and particularly to eliminate water from the oil and thus to provide a condition which favors the Serial No. 98,410.

indefinite preservation of the oil and the avoidance of the development of odor and taste therein.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and the accompanying drawings, in which Fig. 1 is a flow sheet indicating the preferred arrangement of the apparatus employed in carrying out the invention;

Fig. 2 is a plan view of a plant indicating the desirable arrangement of the apparatus;

Fig. 3 is a vertical section through one of the cookers;

Fig. 4 is a vertical section through a settling tank;

Fig. 5 is a sectional view chamber; and

Fig. 6 is a similar view of a trap in which water is separated from the oil before it is delivered to the drying chamber.

In order to produce cod-liver oil of high qualityit is essential to maintain absolute cleanliness of the apparatus employed. The apparatus hereinafter described is designed particularly to permit access to the interior in order that it may be cleaned periodically and thus maintained in a sanitary condition.

The livers which are generally delivered in barrels are carefully selected. They are dumped from the barrels into a storage bin from which they flow to sorting tables. At the tables the operators sort the livers and free them from all foreign material. Any 85 diseased or unsound livers are withdrawn. The good livers are placed in suitable receptacles and transferred to the washing appa ratus where they are subjected to a thorou h washing to remove any adhering foreign su stances. When they have been washed the livers are ready for utilization in the process.

The livers are first chopped in a suitable apparatus provided for that purpose into relatively small pieces and these are transferred to the cooker. The latter is a jacketed kettle capable of holding, for example, about six barrels of the chopped livers and provided with a jacket and a steam coil through which steam may be passed to raise the temof the drying I regulated. Too short a cooking perature of the contents. The coil is provided preferably with small orifices through which the steam can be blown directly into the mass to be cooked. A suitable agitator is likewise provided so that the contents of the cooker can be stirred during the operation.

The cooking of the livers must be closely eriod results in a failure to completely li rate the oil whereas extended cooking lowers the quality of the oil. The total time required to cook a mass of livers containing about six barrels of raw material with the apparatus hereinafter described is about twenty-five minutes. As soon as the chopped livers are placed in the cooker the steam is turned on and passes through the orifices in the-coil directly into the mass. This raises the mass to the boiling point in approximately seven to eight minutes. Some-of the steam is condensed and additional water is derived from the livers so that as the boiling proceeds the amount of water in the cooker increases. As soon as the boiling temperature is reached the introduction of steam is regulated so as to 'maintain the boiling temperature and the operation is 'continued for approximately fi een to seventeen mlnutes. The mass is constantly agitated during the boiling operof the oil, however, does not separate and riseation by the mechanical agitator. A suitable agitator is a propeller having a driving motor directly connected thereto. Such an agitator canbe employed with a plurality of cookers. The cooking accomplishes the coagulation of albuminous material which has a tendency to emulsify the oil and permits the oil to be liberated quite completely from the chum or waste material.

During the boiling the fat cells in the livers are broken down and the oil is released. All

to the surface of the mass. Consequently there is no danger of injury to the oil by contact of the atmosphere therewith. Furthermore, the steam rising from the mass efl'ectually excludes air from the surface thereof and the oilis thus protected.

As soon as the cooking is completed the mass is transferred by means of a sludge pump to a separating tank which is provided with heat insulated walls so. that the mass of material may remain therein for a considerable period without substantial reduction of the temperature thereof. This avoids the necessity of heating the material in the separating tank and ensures the maintenance of the mass at a temperature above 140 F. So long as this or a higher temperature is maintained there is no tendency for putrefaction or fermentation of the mass. At lower temperatures the, liver tissue is extremely sensitive and decomposes rapidly owing to the presence of bacteria and enzymes therein. The avoidance of these undesirable reactions separating tank the latter is blown out with steam to remove all of the air therefrom and when the material has been introduced to the tank, steam is again blown over the surface to remove any air which may be present and an inert gas such as carbon dioxide is introduced to the space above the mass to ensure the absence of air in the atmosphere above the oil which quickly separates. .The mass settles into three layers, the oil being at the top and overlyinga layer of cooked liver tissue. The bottom layer consists of water carrying some fragments of liver tissue. About one-third of the contents of the tank will normallybe oil and this represents the greater portion of the oil recovered from the livers. There is, however, a certain amount of oil trapped in the fragments of liver tissue.

At the end of about thirty minutes the overlying layer of oil is withdrawn as hereinafter described and a screen is then introduced in the tank above the level of the layer of liver tissue therein. The screen should be of relatively fine mesh adapted to prevent the passage of the fragments of liver tissue and it is firmly clamped in place by means provided for that purpose. Hot water is then introduced at the bottom of the tank in regulated quantity. The addition of water causes the layer of liver tissue to rise until it strikes the screen and the continued introduction of hot water under pressure results'in the passage of water through the liver tissue andthe separation therefrom of the oil which is mechanically held by the fragments. A considerable additional recovery of oil is thus possible. The oil floats upon the water and can be withdrawn and mixed with the oil recovered in the first separation.

Throughout the period of settling and the separation of the oil from the material in the settling tank a non-oxidizing atmosphere is maintained in contact with the oil. The oil is removed by suction applied through suitable connections to a funnel having a screened inlet which permits the oil to pass from the tank. Some water may escape with ing decomposition reactions with the resulting development of odor and taste in the oil. Furthermore, the dissolved water contains albuminous matter which likewise facilitates decomposition.

The removal ofthe water is accomplished by spraying the warm oil into a chamber which is maintained under a suitable vacuum. The vacuum or drying chamber is jacketed for steam or other heating media and is thereby maintained at a suitable temperature, for example, 150 F. As the oil is drawn through the spray head it is atomized and at the temperature maintained the moisture content is evaporated and withdrawn from the chamber. The oil is separately collected and is delivered from the drying chamber to a filter press which serves to remove albuminous material which coagulates upon the withdrawal of moisture from the oil. The removal of the albuminous material reduces the possibility of subsequent decomposition of the oil. Provision is made in the apparatus to permit the introduction of an inert gas such as carbon dioxide as may be necessary to prevent the entrance of air and contact thereof with the oil and especially to permit flooding of the system with the inert gas when the operation is temporarily discontinued.

It is possible to employ other methods of drying the extracted oil. The vacuum centrifugal method may be used. This method consists of running the oil through a centrifuge, the head 01' top of which is so inclosed in a chamber that it can be operated under vacuum. The oil fiows into the bottom of a centrifuge basket which is of relatively small diameter and quite tall, and in traveling upward dispersed water is separated from it as are also dispersed solids. The dispersed solids form a layer in the centrifuge bowl, whereas the water and oil flow upward in two separate layers from which the oil over flows. As the bowl is spinning at very high speed the overflowing oil is thrown out in the form of a spray, and as the head is kept under vacuum you really get the effect of a spray dryer from this machine. The oil collects in the head and runs out by gravity. The use of such a centrifuge, of course, does not eliminate the necessity of a filter press, for some material is coagulated by the evaporation of dissolved moisture, but much less material needs to be removed after running the oil through such a centrifuge than is the case when spray drying is used, because none of the solids, which usually represent fragments of liver tissue, are removed in the spray drying process.

After the oil has been filtered it may be delivered to suitable containers. These may be evacuated before the oil is permitted to i enter or preferably they may be filled with an inert gas such as carbon dioxide which is displaced by the oil. The oil is introduced to the receptacles without contact with the air and a suflicient amount of the inert gas remains in the receptacles above the level of the oil therein to prevent contact of the air and consequent destruction of the vitamin content of the oil.

' The maintenance of the oil out of contact with the air throughout the several operations from the cooking of the livers to the final packaging of the oil is essential to the production of a high grade product containing the maximum vitamin content. Codliver oil has a marked afiinity for oxygen so that if a quantity thereof is shaken in a bottle containing air a partial vacuum will be created if the bottle is closed and an analysis of the gas above the oil will show that it is free from oxygen. It is probable that while a brief exposure of the oil to the atmosphere has little immediate effect upon the vitamin content of the oil, the oxidation products which are readily formed in the cod-liver oil attack the vitamins and thus eventually cause deterioration of the oil. While the explanation noted is notnecessarily acorrect statement of the effect of oxygen, t is nevertheless true that the oil derived 'by the process herein described is markedly superior to ordinary cod-liver oil in its vitamin content, its freedom from odor and taste and its lack of susceptibility to deteriorating influences.

The process and its application may be more readily understood by reference to the accompanying drawings, in which 5 indicates a suitable platform upon which the barrels containing the livers are received. The livers are dumped into a bin 6 having a plurality of outlets 7 which discharge upon sorting tables 8. Each of these tables is in charge of an operator who selects the livers to be used in the process and places them in barrels 9. The barrels are conveyed to a washing trough 10 where the livers are subjected to a thorough washing with Water. They are then discharged upon a screen 11 which permits the draining of the water therefrom and passed thence to a chopping machine 12. The latter may be of any suitable form and construction, the well known Enterprise power chopper being adapted for the purpose. The chopped livers are delivered into receptacles 13 which may be lifted, for example, by a crane 1 1 to permit delivery of the material to one of the cookers 15.

The cooker is a vessel preferably cylindrical in form and having a jacket 16 of heatinsulating material such as ground cork. This prevents loss of heat during the cooking operation and permits greater economy in the handling of the material. The cooker is adapted, moreover, for use as a settling tank when the other tanks of the system are filled with material. A perforated pipe 17 is disposed in the bottom of the cooker and is connected by a pipe 18 to a source of steam under pressure. The steam can be delivered through the perforated pipe directly to the contents of the cooker. An outlet 19 is provided in the bottom of the cooker and is controlled by a valve 20 having a stem 21 and an operating handle 22 adjacent the top of the cooker. A cover 23 having a depending edge 24 is provided so that the cooker may be closed when it is used as a settling tank. The depending edge 24 rests in a water seal 25 which effectually prevents the entrance of air when the cover is in place. A relief vent 26 is provided to permit escape of steam from the space above the material in the cooker and connections 27 and 28 are provided for the introduction of steam and an inert gas such as carbon dioxide.

When the material has been delivered to the cooker the steam is turned on and permitted to flow through the perforated pipe into contact with the material. The cooker is open at the top during this period of the operation and an agitator having, for example, a propeller 28' driven by a motor 29 can be hung on the side of the cooker and operated to cause the proper mingling of the contents of the cooker. Steam is introduced actively until boiling commences and the introduction of steam is regulated thereafter until the cooking is completed Which should be approximately twenty-five minutes after the commencement thereof in a cooker of the capacity mentioned.

a As soon as the cooking is completed the mass is discharged through a pipe 29 and a sludge pump 30 to a settling tank 31. The settling tank is preferably cyllndrical in form and is provided with a jacket 32 filled with heat-insulating material such as ground cork for the purpose of preventing loss of heat from the mass in the settling tank when the mass is permitted to remain therein for a considerable period. The tank is provided with a cover 33 having a depending edge 34 which is adapted to fit a water seal 35 at the top of the tank. Inlets 36 and 37 permitthe introduction of steam or of inert gas such asv carbon dioxide through the cover when the latter is inv place. A vent 38 permits the escape of gas from the tank and prevents the building up of a pressure therein. An outlet 38'- is provided at the bottom of the tank and is closed by a valve39 having a stem 40 and an operating handle 41. A shoulder 42 is provided within the tank to receive a screen 43 which may be held in place on-the shoulder by any suitable clamping means.

As soon as the material has been delivered to the settling tank the oil commences to rise to the surface. After a period of approximately thirty minutes the major portion of the oil will have separated and the two remaining layers in the tank will consist atthe bottom of water containing small particles of the liver tissue and a layer of liver tissue above that and beneath the oil. The layer of oil is withdrawn through a funnel 43' which is connected to a hose 44 and is provided with a screened inlet .to prevent the entrance of liver tissue. Substantially all of the oil on the surface of the mass is thus separated and treated as hereinafter described. The screen 43 is then inserted and fitted in position above the layer of liver tissue, the surface of which should be below the shoulder 42. Thereafter hot water is introduced at the bottom of the tank through an inlet 45. The water which is under a sllght pressure forces the layer of liver tissue to rise against the screen. The hot water percolates through this layer and carries with it'the oil which is mechanically held by, the particles of liver tissue. The oil rises with the water above the screen but the liver tissue is retained thereby. This operation is continued for a period of hours so as to permit maximum recovery of the oil. Meanwhile the mass is maintained at a temperature above 140 F. by the surrounding insulation or is otherwise heated so as to prevent a reduction in the temperature to a point where putrefaction may occur. The layer of oil is withdrawn through the funnel 43 and mixed with the oil first separated. The balance of the material in the settling tank is then discharged and treated as hereinafter described.

The oil passes through a pipe 46 which is connected with the hose 44 and into a Water separator 47. Any water which passes over with the oil from the settling tank drops to the bottom of the separator and the oil is withdrawn from the top thereof and is delivered through a pipe 48 to a drying chamber 49. The pipe 48 terminates in a nozzle 50 in the drying chamber.

The drying chamber is preferably cylindrical in form and is provided with a jacket 51: through which steam or hot water may be circulated to maintain the required temperature therein. The warm oil entering through the pipe 48 is discharged through the nozzle 50 into the chamber in the form of fine oil particles. The exposure of these particles at the temperature maintained results in the vaporization of the moisture content of the oil. The vapor is withdrawn through an outlet 52 which is connected to a suitable vacuum pump. Abaflie 53 prevents the passage of oil particles into the outlet. The oil accumulates in the bottom of the chamber and a gauge 54 is provided to indicate the amount of oil thereincontained. The accumulated oil is withdrawn through an outlet 55 at the bottom of the chamber which connects through a pipe 56 to a puinp 57 which forces the oil through a filter press The filter press 58 of the ordinary type. separates coagulated albuminous material and any other solid material which may remain in the oil. The clear oil is delivered through a pipe 59 to a receptacle 60 which is adapted for the transportation and storage of the oil. Preferably the receptacle is flushed with an inert gas such as carbon dioxide before it is connected to the filter press, the inert gas being displaced as the receptacle is filled.

A. container 61 for an inert gas, for example, carbon dioxide under pressure is connected to the pipe 56'so that the inert gas can be delivered to the drying chamber, to the filter press and elsewhere through the system either to maintain a non-oxidizing atmosphere in contact with the product during the operation or to force air from the system. The pressure equalizer may conveniently be a flexible gas-tight bag Which expands and contracts according to the pressure in the gas line, so that the surges and pressure variations of the gas will be absorbed and a substantially steady flow of gas produced. It is an important feature of the invention that air is prevented from coming in contact with the oil through-out the operation from the cooking of the livers to the final packaging of the product. In the cooking operation it is not necessary to use an inert gas because of the presence of steam above the mass. Thereafter tne inert gas is introduced wherever there is a possibility of the presence otherwise of oxygen in contact with the oil; A pipe 62 is connected to the vapor outlet line 52 of the drying chamber and to a coil 63 which is disposed in a suitable receptacle 64 adapted to be supplied with cooling water. The coil causes the condensation of the moisture recovered from the oil and this can be discharged through an outlet pipe 65 to the sewer or elsewhere. A vacuum pipe 66 which may be connected to anysuitable exhausting device forms a branch of the pipe 65 and maintains the necessary reduced pressure in the drying chamber;

The liver tissue from the settling tank still contains some oil after the second separation thereof. It is delivered consequently to a centrifugal 67 of the usual type in which a large proportion of the water and oil present is separated by centrifugal force. The oil, being thereby subjected to a certain amount of contact with the atmosphere, is inferior to the oil recovered by skimming from the settling tank. The oil is therefore separated from the water and sold as No. 2,0il. The remaining solid material may be removed from the centrifugal and treated further for the production of desired by-products. A further amount of oil may be obtained, for example, by pressing, or the mass maybe dried under vacuum for the purpose of obtaining anhydrous liver tissue which will consist approximately of 50% protein and from 30 to 35% of fat, the balance being fibre, mineral matter, etc. This material is suitable for various uses such as the production of cattle feed and fertilizers in which the nitrogenous content of the material is valua le.

It is to be understood that in the operation of the plant as described a plurality of cookers are preferably employed and a sufficient number of settling tanks are provided to permit the handling of the product of the cookers. The settling tanks and cookers are conveniently arranged to facilitate the handling of the material and particularly the discharge of the solid materials to the centrifugal. Since it may be necessary at times to hold the cooked product in the cookers the latter are designed as settling tanks and the operations described with respect to the settling and removal of the oil may be conducted in the cookers. In fact, the settling tanks can be omitted and the operation can be conducted up to the point of discharging the solid material to the centrifugal solely in the cooker. In this case the cooker will remain open during the cooking operation since the steam excludes air and the cover provided for the purpose will be applied before settling commences so that all of the air can be evacuated from the cooker and contact of oxygen with the oil prevented thereby.

The dehydration of the oil results in a marked improvement in the quality thereof, particularly with respect to the inhibiting of the development of odor and taste therein. Since the development 'of odor and taste is apparently the result of decomposition of some constituent of the oil, it is apparent that the removal of the water results either in the removal of this constituent or produces a, condition in which decomposition is no lon er possible. It is quite probable that the improved quality of the 011 results from the separation of albuminous matter which, as hereinbefore noted, coagulates when the oil is dehydrated. I have discovered, however, that the presence of odor and taste in the oil can be inhibited also by the addition of a suitable salt to the livers during the cooking operation or subsequently to the oil. Common salt (sodium chloride) is well adapted for this use. From 5 to 10% of common salt can be added to the livers when they are cooked. The presence of salt in the liquor with which the oil is in contact has the eifect apparently of wholly or partially dehydrating the oil. Because of the limited amount of water in the separated oil as little as one-half pound of common salt per barrel of oil will secure the desired result. The albuminous matter which is detectable in the oil only when it contains absorbed water is prevented apparently from entering the oil when it is in contact with the saline solution or is preserved by the salt. Consequently an oil of improved quality is recovered when salt is added.

Whether or not a salt is added I prefer to dehydrate the'oil in the drying chamber as hereinbefore indicated. The two operations can be combined with advantage to produce an oil of the highest quality which, ifstored and transported out of contact with the atmosphere, will retain its valuable vitamin content at substantially the initial stren h and will remain free from disagreeable 0 or and taste for an indefinite period. I am enabled thereby to produce an' improved and valuable cod-liver oil product by the application of the principles hereinbefore described.

Various changes may be made in the details of the operation as described and in. the construction and arrangement of the apparatus employed therein without departing from the invention or sacrificing anypf the advantages thereof.

I claim In the process of producing a medicinal cod liver oil, the step of atomizing the oil and simultaneously heating it under reduced pressure to remove moisture therefrom, filtering the heated oil to remove solid impurities therefrom, and delivering the filtered oil to storage receptacles, all of the said steps being carried out in the absence of air and in the presence of an inert as.

In testimony whereof I a m si FERDINAND W. NIX

ature. DY.

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