US3443959A - Process for the treatment of powdered products - Google Patents

Process for the treatment of powdered products Download PDF

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US3443959A
US3443959A US438991A US43899165A US3443959A US 3443959 A US3443959 A US 3443959A US 438991 A US438991 A US 438991A US 43899165 A US43899165 A US 43899165A US 3443959 A US3443959 A US 3443959A
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powder
powders
stream
drying
air
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Jacques Jean Ciboit
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Laguilharre Ets
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Laguilharre Ets
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    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
    • A23C9/00—Milk preparations; Milk powder or milk powder preparations
    • A23C9/16—Agglomerating or granulating milk powder; Making instant milk powder; Products obtained thereby

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  • PROCESS FOR THE TREATMENT OF POWDERED PRODUCTS Filed Maron 11. 1965 sheet 3 or 4 /YTTOPA/f/J PROCESS FOR THE TREATMENT OF POWDERED PRODUCTS 30021050240 289 iw/901600930150 [l0 130 120 Il@ [00 95 JIM 7 4' TTOPA/[KS United States Patent O 3,443,959 PROCESS FOR THE TREATMENT OF POWDERED PRODUCTS Jacques Jean Ciboit, Paris, France, assignor to Etablismes Laguilharre, Courbevoie, Hauts-de-Seine, France, a corporation of France Filed Mar. 11, 1965, Ser. No. 438,991 Claims priority, application France, Mar.
  • the present invention has for its object a process for the treatment of powdered products which are derived especially from a spray-drying process and which are intended to be redispersed either in solution or in suspension for subsequent utilization as is the case, in particular, with milk-product powders.
  • the invention also includes within its scope the devices for the practical applicatio-n of said process and, by way of novel industrial products, the powders which are obtained by means of said process.
  • the processes of the first group make use of a finelydivided storage powder which is rehumidified in order to obtain agglomerates of substantial size which are subjected to a subsequent drying process.
  • These processes have a disadvantage in that they are in practice only applicable to powders which have a high initial density and result in the production of instantaneous powders which have a low density (substantially of the order of one-half the initial density) and a heterogeneous particle-size distribution as well as high fragility.
  • the apparatus employed for the treatment must in addition be kept under constant supervision by reason of the dangers of clogging which arise from excessive moisture content.
  • the processes of the second group are intended to obtain a powder which has a high moisture content directly at the delivery end of the spray-drying chamber and the grains of which are agglomerated and dried without any further introduction of moisture.
  • the processes of this group have a disadvantage in that they also call for continuous supervision of the spray-drying apparatus by reason of the sticky nature of the powder which is prod-uced in this latter and which has a high moisture content.
  • Such processes do result in the production of powders of relatively high density, the wettability of said powders is nevertheless substantially lower than that of powders obtained by the processes of the first group.
  • the treatment process in accordance with the invention makes it possible to obtain powders which are endowed with excellent wettability as well as a uniform particle-size distribution and the small-size agglomerates of which are not fragile and can readily be stored in bags, while the density of said powders is generally higher than that of powders which are obtained in conventional rehumidfying apparatus. Moreover, this process effects in a very short time perfectly uniform humidilflcation of the treated powder, thus subsequently calling only Ifor a relatively small addition of moisture which is compatible with stable industrial operation, which in turn eliminates the functional disadvantages of the known processes hereinabove referred-to.
  • the process in accordance with the invention essentially consists in producing a stream of powder to be processed and at least one stream of a humidifying fluid which are substantially in parallel and coaxial relation, and a stream of drying air which is substantially parallel and coaxial with the first two streams and surrounding said first two streams, and in rapidly contacting these different streams with a View to effecting instantaneously the humidification of the powder and immediate subsequent drying thereof, then in separating the processed powder from the air.
  • a stream of conditioned air which is substantially parallel and coaxial with the streams referred-to above can additionally be generated between the streams of powder and humidifying fluid and the stream of drying air and can also be rapidly contacted with all of the other streams.
  • the stream of powder can be produced either by means of a mechanical feed process of known type or preferably by putting the powder in suspension in a carrying airstream which is accordingly charged with a high proportion of powder.
  • a humidifying fluid is understood to mean any fluid which is charged with moisture and which is capable of imparting its moisture to the powder by being contacted with this latter.
  • Said fluid can either be a gas or else can consist of a finely atomized aqueous liquid.
  • a gaseous humidifying fluid this latter can be, for example, steam, hot moisture-laden air, or a mixture of air and steam.
  • said fluid can either be water or a solution or aqueous suspension of the same product as the powder to be processed, or alternatively a solution or aqueous suspension of another product which it may be found ⁇ desirable to mix with the powder to be processed.
  • the ⁇ stream of powder to be processed is preferably located inside the ⁇ stream of humidifying fluid and this latter surrounds the stream of powder in coaxial relation therewith, ⁇ although this arrangement is not an essential feature.
  • the humidifying fluid is an atomized or vaporized liquid
  • this fluid will be located inside the -stream 4of powder and this latter will accordingly surround the humidifying lluid in coaxial relation therewith. Provision can also be made for two streams of gaseous lhumidifying fluid, one stream being located in the axis of the stream of powder and the other stream being located around this latter.
  • the stream of drying air which flows externally of and coaxially with the streams of powder and of humidifying fluid will preferably consist of hot air. If a lstream of conditioned air is additionally provided, said conditioned air can 'be at a temperature and possibly also have a degree of humidity which are variable according to the powders to be processed and the said stream of conditioned air can also be circulated at a velocity which is different from that of the humidifying fluid and/ or the drying air. In order that the humidilication of the powder should be uniform and be accompanied by a certain readhesion of the powder grains by collision, it is necessary to impart high iiow velocities to the humidifying iiuid and/or the powder stream.
  • the flow velocity thereof can be of the order of 50 to 200 meters per second, whilst lthe powdercarrying airstream which is charged in a proportion of kilograms of powder 4per cubic meter -of air, for eX- ample, will have a flow velocity of the order of 30 to 60 meters per second, for example. If the hum-idifying fluid -is an -atomized Iliquid, the powder-carrying airstream will have a high flow velocity, for example 50 to 250 meters per second.
  • the powder-carrying airstream will preferably be cold and a rotational Iflow motion will preferably be imparted to said powder-carrying airstream in order to obtain a uniform distribution of the powder and to ensure that this latter is immediately and intimately contacted with the humidifying -uid as soon as the powder is in the presence of said iluid. It is intended in this manner to give greater effectiveness to the process -of uniform humidication of the powder grains and of adhesion of said grains to each other.
  • the processed powder can be a normal storage powder in a finely divided state and having an initial moisture content which is lower than 4% or alternatively a powder which is supplied directly and continuously from a spray-drying plant.
  • the powder to be processed can in that case advantageously be a powder which is collected at the delivery end lof a spray-drier with a moisture content within the range -of 4.5 to 7% and preferably with-in the range of 4.5 to 6% in accordance with the process described in my U.S. patent application Ser. No. 434,617 tiled on Feb. 23, i965, now Patent No. 3,410,701, ⁇ and entitled Process for the Production of Milk-Product Powders, and Powders Made by This Process.
  • This last-mentioned process consists in subjecting to a spray-drying process a concentrate containing a proportion of dry material which is higher than 45% and preferably -between 50 and 55% and having a temperature which is higher than 45 C. and preferably in the vicinity of 70 C., lby effecting the drying in the spraydrier until a powder is obtained having a moisture content as hereinabove indicated.
  • the process in accordance with the invention can also advantageously 'be applied to a powder which has been subjected to the double-drying operation described in the aforesaid U.S. patent application, that is to say a powder which has lbeen collected at the out-let of the spraydrier as has just been indicated and having a moisture (water) content within the range of 4.5 to 7% and preferably between 4.5 and 6%, and which has Athen been subjected to a secondary drying operation so as to reduce its moisture content to approximately 3.5%.
  • the powder which is processed -in accordance with lthe invention can be subjected to a complement-ary drying and/or cooling process in ⁇ such a manner as to obtain an end product having a moisture content which is lower than 4% and a suiciently low temperature to permit of storage.
  • the processed powder can also be subjected to a screening or grading operation for the purpose of separating therefrom the fraction which has a particle size above a predetermined value and for the purpose of removing the finest particles therefrom so as to reintroduce them if necessary at a -suitable stage of ⁇ the processing cycle.
  • the screening or grading operation can if necessary be combined with the drying and/or cooling operation.
  • the fraction thus obtained which has the llargest particle size constitutes a high grade instantaneous powder.
  • the device which is provided 'by the invention for the practical application of the process described above essentially consists of Ia kind of combining-tube comprising two coaxial nozzles -through which are canalized respectively the stream ⁇ of powder and the stream of humidifying air and a third nozzle which is located outside said lirst two nozzles in coaxial relation thereto and through which the drying air Iis conveyed, said ythird nozzle Vbeing extended by a pipe which is connected to a separator of the cyclone type, for example, ⁇ in which the processed powder is separated from the air.
  • the device When provision is made for a conditioned air stream, the device comprises a Vfourth nozzle which is placed between the first two nozzles and the third nozzle for the purpose of canalizing said conditioned airstream.
  • the different nozzles which constitute the device are preferably given a tapering frustoconical shape at the outlet extremities thereof so as to have at this point a minimum cross sectional area and thus to increase the discharge velocities of the streams which are fed into said nozzles respectively.
  • the pipe for connecting the outer nozzle which is supplied with drying air to the separator which serves to separate the powder from the air can be cylindrical or slightly divergent.
  • the inlet of the nozzle which serves to canalize said stream can be coupled to a cylindro-conical chamber provided with a tangential inlet through which the powder is introduced, thereby imparting thereto the vortical ilow motion referred-to above.
  • the humidifcation and drying device which 1s constructed in one of the forms indicated above can be coupled or combined with a spray-drying plant for the purpose of processing the powder as this latter is delivered from said plant.
  • ADMI American Dry Milk Institute
  • FIG. 1 is a diagrammatic cross section of a simple form of construction of a humidication and drying combiningtube in accordance with the invention
  • FIG. 2 is a diagram of the complete installation for the execution of the treatment process in accordance with the invention.
  • FIG. 3 is a diagrammatic cross section of a humidication and drying combining-tube which is provided with a fourth nozzle for the admission of conditioned air;
  • FIGS. 4 and 5 are diagrammatic cross sections of two alternative forms of construction of the combining tube of FIG. 1;
  • FIG. 6 is a diagrammatic cross section of the test-tube which is employed for measuring the porosity of a powder as a function of the bulk density of said powder;
  • FIG. 7 is a diagram representing the results of actual measurements taken on a number of different powders of instantaneous skimmed milk
  • FIG. 8 is a diagrammatic cross section of the equipment employed for the purpose of carrying out wettability and self-dispersion tests
  • FIG. 9 is a diagram representing the results of comparative tests performed on .powders of instantaneous skimmed milk available on the market and on skimmed milk powders according to the invention, in regard to the variations in wettability and in self-dispersion of the powders as a function of their porosity.
  • the humidiiication and drying combining-tube which is designed for the execution of the process in accordance with the invention consists of two coaxial nozzles 1 and 2 for the canalization of streams of powder and humidifying fluid and a single peripheral nozzle 3 for the canalization of the drying air.
  • the powder is preferably conveyed by a stream of carrying air and fed through the central nozzle 1 whilst the humidifying fluid which is gaseous in this case and which consists, for example, of steam, is introduced at 2a into the nozzle 2.
  • Said nozzle 2 advantageously has a frustoconical portion which terminates in a discharge end of smaller diameter and the humidifying fluid is introduced therein at a certain pressure so as to be endowed with a high discharge velocity which is preferably comprised between 50 meters per second and 200 meters per second.
  • the central nozzle 1 which conveys the powder has in this case a cylindrical shape but can also comprise a frustoconical portion which forms a discharge outlet of smaller diameter; the discharge velocity of the powder stream can vary between 30 and 60 meters per second.
  • the drying air which is admitted at 3a is in principle hot air, for example at a temperature of approximately 140 C.
  • the nozzle 3 which canalizes said hot air has in this case a convergent rustoconical shape and is extended -by a conduit 4 which terminates in a separator for separating the powder from the air (not shown in FIG. 1).
  • the conduit 4 consists in this example of a portion of divergent frustoconical shape followed by a cylindrical portion 4a but could also be cylindrical over its full length.
  • the powder and humidifying fluid which pass out of the nozzles 1 and 2 are contacted with each other and with the drying air canalized by the nozzle 3 and are intimately mixed therein, and in said conduit also that the instantaneous humidication of the powder and subsequent drying thereof consequently take place.
  • the rate of mixing within said conduit is preferably within the range of 10 to 2O meters per second.
  • the length of the conduit can be as desired but is preferably between 1 and 3 meters.
  • the nozzle 1 which serves to inject the stream of powder is connected at the upstream end thereof to a cylindro-conical chamber 5 to which the powder supply duct 6 is connected tangentially in order to impart a vortical flow motion to the powder-charged airstream.
  • the duct 6 starts, for example, from a device 7 in which the powder to be processed is discharged from a hopper 8 and is put in suspension in a stream of compressed air which is fed in at 9.
  • the powder can be, for example, a storage skimmed-milk powder having a moisture (water) content which is less than 4%.
  • the supply of powder to the hopper 8 and the delivery of compressed air which is admitted at 9 can be regulated, for example, in such a manner that the proportion of powder with which the air stream is charged is of the order of 10 kilograms per cubic meter of air.
  • the humidifying fluid which is introduced at 2a into the nozzle 2 of the combining-tube consists, for example, of steam derived from a suitable source or of a mixture of steam and air, for example a mixture of steam and air in equal proportions by weight.
  • This fluid is admitted within the nozzle 2 under a pressure such that its velocity at the outlet of said nozzle is preferably comprised within the above-mentioned limits of 50 to 200 meters per second, whilst the velocity of the powder at the outlet of the nozzle 1 is preferably comprised within the limits also given above of 30 to 60 meters per second.
  • the drying air is admitted at 10 in the form of cold air and is directed by a fan 11 into a heating battery 12 in which its temperature is brought, for example, to C. and is admitted at 3a into the peripheral nozzle 3 of the combining-tube A.
  • the flow rate of the drying air can be, for example, between 1500 and 2000 cubic meters per hour for the purpose of processing 500 kilograms per hour approximately of powder.
  • a separator of the cyclone type in which the gaseous mixture together with the powder delivered by the combining-tube A is conveyed through the conduit 4 which, in this example, is cylindrical throughout its length.
  • the air which is separated from the powder is discharged from the top of the separator 13 by means of a fan 14 and the processed powder is withdrawn from the bottom of the separator by means of a drum 15 and discharged, for example, onto a vibratory refrigerating table 16 on which the powder is cooled by a flow of cold air which is driven by a fan 17 and subjected to a classifying or grading process.
  • the fraction having the largest particle size is collected at 18 and accordingly constitutes an excellent instantaneous powder which has a relatively ner particle size and higher density than the instantaneous powders which are at present known.
  • the fines are sucked out and directed through a pipe 19 into a cyclone separator 20 which is coupled to a fan 21.
  • the air which is separated from the nes is discharged at the top of the separator 20 and the iines are extracted at the bottom of this latter and discharged through a drum 22 into the hopper 8 so as to be reincorporated in the powder to be processed.
  • the table 16 could comprise a rst section which is supplied with hot air so as to produce a complementary drying of the powder as contemplated above.
  • FIG. 3 illustrates a processing combining-tube which is similar to the tube of FIG. 1 but which, apart from the nozzles 1, 2 and 3 which serve to canalize the streams of powder, humidifying Huid and hot drying air, is also provided with a fourth nozzle 23 for the admission of conditioned air which is fed in at 23a and which, depending on the powders to be processed, can ybe either hot or cold.
  • the four nozzles which are disposed in coaxial relation are endowed at the discharge end thereof with a convergent frustoconical shape for the purpose previously stated.
  • FIG. 3 illustrates a processing combining-tube which is similar to the tube of FIG. 1 but which, apart from the nozzles 1, 2 and 3 which serve to canalize the streams of powder, humidifying Huid and hot drying air, is also provided with a fourth nozzle 23 for the admission of conditioned air which is fed in at 23a and which, depending on the powders to be processed, can ybe either hot or cold.
  • the nozzle 1 through which the powder in suspension in an airstream is canalized is connected at its upstream end to a cylindro-conical chamber fitted with a tangential intake 6 for the purpose of imparting a vortical flow motion to said airstream.
  • this latter is canalized through the central nozzle 1.
  • the discharge end of the nozzle 1 could be fitted with a spraying nozzle to which the liquid could be brought under pressure.
  • the mixture of air and powder which is conveyed through the nozzle 2 will be brought into this latter under a certain pressure in such a manner as to obtain at the outlet of said nozzle a high rate of expansion permitting the atomization of the liquid as this latter is discharged from the nozzle 1.
  • the velocity of the powder-carrying gas-flow will thus be high and preferably between 100 and 250 meters per second, which will accordingly assist collisions between the powder grains and droplets of liquid.
  • the spray atomization of the liquid could be produced by means of an auxiliary jet of compressed air which is brought to the outlet of the nozzle 1 in a manner which is known per se.
  • FIG. 5 represents another alternative form of embodiment of the humidiication and drying combining-tube in which the nozzle 1 which conveys the powder-carrying gas-flow is disposed coaxially between two concentric nozzles 2 and 2 for receiving the humidifying fluid which, in this case, consists of a gaseous fluid.
  • the drying air nozzle 3 is disposed, as in the previous examples, at the periphery of the assembly.
  • the nozzle 1' to which the powder is supplied is connected, as previously stated, to a cylindro-conical chamber 5 which is provided with a tangential intake 6 for the admission of powder.
  • the humidification and drying device as designed in one of the forms which have been described or in an equivalent form can be coupled with a spray-drying installation for the purpose of processing the powder as this latter is produced in said installation.
  • This application proves to be particularly effective for the direct and continuous processing of a powder which is collected at the delivery end of a spray-drier and has a moisture content in the range of 4.5 to ⁇ 6% in accordance with the process described in the aforesaid U.S. patent application, but can also be utilized for the direct and continuous processing of a normal finely-divided powder which is collected at the delivery end of the spray-drier and having a moisture content below 4%.
  • the hot drying air and/or conditioned air which is fed to the humidiication and drying combining-tube can be taken directly from the spray-drying plant.
  • the air which carries the powder to be processed can be drying air or conveying air which is derived at the same ltime as the powder from the separator of the spray-drying plant or from one of the separators if provision is made for a number of these latter.
  • the delivery of the fan located at the outlet of the separator of the humidiication plant (for example the separator 13 of FIG. 2) can be returned to any suitable point of the Spray-drying plant upstream of the spray-drying plant separators (either into the spray chamber or 1nto the pipes upstream of the separators) so as to effect a recovery of the fines.
  • the application of the process and devices in accordance kwith the invention iS. not limited to a direct and continuous treatment of a finely divided powder which is collected at the delivery end of a spray-drier but, as has also been indicated above, said process and device can also be applied to the treatment of finely-divided storage powders which have a moisture content below 4% and more especially of powders which have undergone the double-drying process contemplated in the aforesaid U.S. patent application.
  • test-tube was dropped three times from a height of 2.5 centimeters at two-second intervals while avoiding any jerks when lifting the test-tube.
  • the test-tube was dropped onto a hard wood surface. This falling motion must be uniform and accurately timed.
  • test-tube was then allowed to rest for a period of thirty seconds, whereupon the volume taken up by the ptowder within the test-tube was then read, the testtube containing the sample was weighed and the exact weight of the test sample was then determined.
  • the bulk density of the powder is expressed by the ratio:
  • the porosity of a milk powder defined earlier as the volume of open spaces between the powder grains, could be calculated on the basis of the bulk density of the powder, the density of the solids constituting the powder and the volume of occluded air within the grains.
  • the present applicant has adopted a similar method which consists in measuring the volumes of the open spaces between the grains of powder which is immersed in petroleum ether. This method has been adopted on account of the good reproducibility of measurements.
  • the equipment employed consists of a cylindrical glass test-tube having an internal diameter of 25 millimeters and graduated in cc. up to cc.
  • the teso-tube is shown diagrammatically at 24 in FIG. 6. There were poured into said test-tube 85 cm.3 of petroleum ether of the class 40-65" at a temperature of 20 C. The level reached by the petroleum ether within the test-tube is shown in the ligure at a.
  • a quantity of 25 grams of powder to be analyzed was placed on a sheet of smooth paper which was perfectly dry and the powder was slowly introduced into the testtube 24 by causing said powder to slide (without pouring) down the sheet into the test-tube.
  • the time of introduction must be of the order of two minutes, the introduction being continuous and uniform and all precautions being necessarily taken to avoid any shaking or compression of the powder while this operation is in progress.
  • the outer surface of the test-tube can in that case be tapped lightly.
  • the level b attained by the powder in the bottom of the test-tube and the level c attained by the petroleum ether were noted.
  • the volume which is comprised between the level c and the initial level a of the petroleum ether corresponds to the volume of the powder grains whilst the lower volume which is defined by the level b corresponds to the sum of the volume of the grains and the volume of free spaces between the grains within the petroleum ether.
  • Wettability and self-dispersion It is ⁇ known that the quality of instantaneization f a milk powder is characterized especially by the values of wettability and self-dispersion of said powder, these properties having been dened earlier.
  • the equipment employed for these tests consisted (as shown in FIG. 8) of a stationary screen 25 having a mesh size of 6 millimeters and placed above a Buchner funnel 26 having a diameter of 85 millimeters and fitted at the bottom end with a rubber tube 27 closed by means of a clip 28 and containing 100 cc. of distilled water at 40 C., the screen 25 being placed at a distance of 80 millimeters above the level of the water.
  • a wire-mesh filter 29 having a mesh size of 200 microns and xed within an ordinary funnel 30, the stem of which was placed within a graduated glass test-tube 31 having a capacity of 120 cc.
  • the screen 25 was carefully dried by lightly heating so as to prevent any sticking of the powder to the surface of the meshes. Then, cubic centimeters of distilled water at 40 C. (in the case of skimmed milk powders) were poured into the Buchner funnel 26 and the temperature was balanced when necessary by heating the funnel 26 with a Bunsen burner, l0 grams of powder to be analyzed being then poured onto the screen 25. The time taken by the powder to disappear by immersion and/ or dissolving in the water contained in the Buchner funnel 26 constitutes the test for determining the wettability of said powder. Said time is measured from the moment when the powder is initially poured onto the screen 25 (this pouring operation being performed very rapidly) up to the moment when the powder has completely disappeared from the surface of the water.
  • the ⁇ clip 28 was opened and the product was allowed to flow out into the filter 29 and into the test-tube 31 located underneath the funnel 30.
  • the outflow time must not exceed one minute.
  • test-tube 31 The filling of the test-tube 31 was then completed with distilled water up to its full capacity of cc.; the testtube was turned upside down so as to homogenize its contents and the weight of dry extract of the filtered liquid was then measured. This weight of dry extract makes it possible to determine the percentage of weight of powder which has passed into solution. It is this percentage which expresses the self-dispersion of the powder.
  • Curve C represents the maximum values of self-dispersion of commercially available instantaneous skimmed milk powders which have been subjected to the tests and curve D represents the minimum wetting times of the same powders. It is observed that the values indicated by these curves in respect of a porosity P ranging between 350 cubic centimeters and 100 cubic centimeters correspond to the values given by the following empirical formulae:
  • the instantantous skimmed milk powders which are available on the market have a very low bulk density.
  • This bulk density which is measured according to the method described above, is usually lower than 0.35.
  • these powders have at the same time a porosity which is distinctly higher than 200 cubic centimeters in respect of 100 grams of powder.
  • Their self-dispersion in distilled water at 40 C. which is usually lower than the maximum Values indicated by the top portion C1Cx of curve C of the diagram of FIG. 9 is comprised within the range of 85 to 92% and their wetting time, also in distilled water at 40 C., is higher than the values indicated by the bottom portion DlDx of curve D and ranges from 8 to 30 seconds.
  • the powders in accordance with the invention also have high characteristics from the point of view of self-disper- Sion and wetting time in the case of porosity values below cubic centimeters per 100 grams of powder; these porosity values are not met with in instantaneous skimmed milk powders which are available on the market.
  • the powders according to the invention have wetting times of less than two minutes and self-dispersion values which are higher than 35%.
  • the present applicant has observed that, in the case of a porosity below 200 cubic centimeters per 100 grams of powder, the products in accordance with the invention have a degree of fragility during manufac ture, handling, transportation and storage which is considerably lower than that of instantaneous s-kimmed milk powders which are sold on the market.
  • the products manufactured in accordance with the invention can even be delivered in bags without any appreciable reduction in their properties. It would appear that the lower degree of fragility mentioned above is not due to a difference in individual fragility of the aggregates which constitute the powder but to the fact that the product which is processed according to the invention has a more uniform particle size distribtuion and, consequently, a lesser tendency to self-grading.
  • a process for the treat-ment of powdered material, particularly milk product powders which comprises the steps of:
  • the powdered material to be processed is a normal storage powdered material in a nely divided state and having an initial moisture content which is lower than 4%.
  • the powdered -material to be processed is obtained by subjecting to a spray-drying process a concentrate containing a proportion of dry material which is higher than 45% and preferably between 50 and 55% and having a temperature which is higher than 45 C. and preferably in the vicinity of 70 C., and which has been collected at the delivery end of the spray-drier, with a moisture content ranging from 4.5 to 7% and preferably from 4.5 to 6%.
  • the humidifying iluid is a moisture-charged gaseous uid which is capable of imparting its moisture to the powdered material by being contacted with said powdered material.

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  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Dairy Products (AREA)
  • Formation And Processing Of Food Products (AREA)
  • Medicinal Preparation (AREA)
US438991A 1964-03-13 1965-03-11 Process for the treatment of powdered products Expired - Lifetime US3443959A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR967330A FR1403677A (fr) 1964-03-13 1964-03-13 Procédé et dispositifs pour le traitement de produits en poudre, et en particulier de poudres de produits laitiers, et poudres obtenues par ce procédé
FR7459A FR91307E (fr) 1964-03-13 1965-03-01 Procédé et dispositifs pour le traitement de produits en poudre, et en particulier de poudres de produits laitiers, et poudres obtenues par ce procédé

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BE (1) BE660826A (de)
CH (1) CH447791A (de)
DE (1) DE1492781A1 (de)
ES (1) ES310457A1 (de)
FR (1) FR91307E (de)
GB (1) GB1071850A (de)
LU (1) LU48172A1 (de)
NL (1) NL6503265A (de)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3649291A (en) * 1966-06-24 1972-03-14 Welvo Nv Tromplaan Process for the preparation of granular, water-soluble, livestock forage
US4597970A (en) * 1984-10-05 1986-07-01 Warner-Lambert Company Chewing gum compositions containing novel sweetener delivery systems and method of preparation
US4752485A (en) * 1984-10-05 1988-06-21 Warner-Lambert Company Novel sweetener delivery systems
US4797288A (en) * 1984-10-05 1989-01-10 Warner-Lambert Company Novel drug delivery system
US4804548A (en) * 1984-10-05 1989-02-14 Warner-Lambert Company Novel sweetener delivery systems
US4828857A (en) * 1984-10-05 1989-05-09 Warner-Lambert Company Novel sweetener delivery systems
US4894233A (en) * 1984-10-05 1990-01-16 Sharma Shri C Novel drug delivery system for decongestants
US4894234A (en) * 1984-10-05 1990-01-16 Sharma Shri C Novel drug delivery system for antiarrhythmics
US4933183A (en) * 1984-10-05 1990-06-12 Warner-Lambert Company Novel drug delivery system for mineral supplements
US4935242A (en) * 1984-10-05 1990-06-19 Warner-Lambert Company Novel drug delivery system for expectorants
US5400972A (en) * 1990-05-18 1995-03-28 Nestec S.A. Agglomeration nozzle
US5620643A (en) * 1995-10-26 1997-04-15 Minnesota Mining And Manufacturing Company Process for producing fused particle agglomerates
US20040234665A1 (en) * 2001-07-03 2004-11-25 Harjit Singh Powdered natural dairy additive for a consumable beverage and method of manufacturing same

Families Citing this family (3)

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US3622081A (en) * 1969-06-20 1971-11-23 Nestle Sa Nozzle
FR2257326B1 (de) * 1973-06-19 1976-05-28 Rhone Progil
US5069118A (en) * 1990-01-16 1991-12-03 Henningsen Foods, Inc. Mechanism and method for agglomerating food powders

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US2832686A (en) * 1954-09-07 1958-04-29 Pet Milk Company Instantly soluble milk powder and process for making same
US2835586A (en) * 1953-07-27 1958-05-20 Instant Milk Company Dried milk product and method of making same
US3065076A (en) * 1959-04-04 1962-11-20 Afico A G Whole milk powder

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US2835586A (en) * 1953-07-27 1958-05-20 Instant Milk Company Dried milk product and method of making same
US2832686A (en) * 1954-09-07 1958-04-29 Pet Milk Company Instantly soluble milk powder and process for making same
US3065076A (en) * 1959-04-04 1962-11-20 Afico A G Whole milk powder

Cited By (17)

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Publication number Priority date Publication date Assignee Title
US3649291A (en) * 1966-06-24 1972-03-14 Welvo Nv Tromplaan Process for the preparation of granular, water-soluble, livestock forage
US4597970A (en) * 1984-10-05 1986-07-01 Warner-Lambert Company Chewing gum compositions containing novel sweetener delivery systems and method of preparation
US4752485A (en) * 1984-10-05 1988-06-21 Warner-Lambert Company Novel sweetener delivery systems
US4797288A (en) * 1984-10-05 1989-01-10 Warner-Lambert Company Novel drug delivery system
US4804548A (en) * 1984-10-05 1989-02-14 Warner-Lambert Company Novel sweetener delivery systems
US4828857A (en) * 1984-10-05 1989-05-09 Warner-Lambert Company Novel sweetener delivery systems
US4894233A (en) * 1984-10-05 1990-01-16 Sharma Shri C Novel drug delivery system for decongestants
US4894234A (en) * 1984-10-05 1990-01-16 Sharma Shri C Novel drug delivery system for antiarrhythmics
US4933183A (en) * 1984-10-05 1990-06-12 Warner-Lambert Company Novel drug delivery system for mineral supplements
US4935242A (en) * 1984-10-05 1990-06-19 Warner-Lambert Company Novel drug delivery system for expectorants
US5400972A (en) * 1990-05-18 1995-03-28 Nestec S.A. Agglomeration nozzle
US5569479A (en) * 1990-05-18 1996-10-29 Nestec S.A. Process for agglomerating powder-form materials
US5620643A (en) * 1995-10-26 1997-04-15 Minnesota Mining And Manufacturing Company Process for producing fused particle agglomerates
US20040234665A1 (en) * 2001-07-03 2004-11-25 Harjit Singh Powdered natural dairy additive for a consumable beverage and method of manufacturing same
US20050287271A1 (en) * 2001-07-03 2005-12-29 Harjit Singh Method and apparatus for preparing a consumable beverage
US7651718B2 (en) 2001-07-03 2010-01-26 Nature's First, Inc. Method for preparing consumable vending machine beverage
US20100021613A1 (en) * 2001-07-03 2010-01-28 Nature's First, Inc. Powdered Dairy Additive and Mixture Designed for Use in a Vending Machine and Vended Consumable Beverage Made Therewith

Also Published As

Publication number Publication date
FR91307E (fr) 1968-05-24
DE1492781A1 (de) 1969-09-11
CH447791A (fr) 1967-11-30
NL6503265A (de) 1965-09-14
LU48172A1 (de) 1966-09-12
ES310457A1 (es) 1966-01-01
BE660826A (de) 1965-09-09
GB1071850A (en) 1967-06-14

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