US3143428A

US3143428A - Method and apparatus for agglomeration

Info

Publication number: US3143428A
Application number: US229713A
Authority: US
Inventors: Frederick E Reimers; Marvin D Miller; Naborney Erwin
Original assignee: American Sugar Co
Current assignee: American Sugar Co
Priority date: 1962-10-10
Filing date: 1962-10-10
Publication date: 1964-08-04
Anticipated expiration: 1981-08-04

Description

g- 1964 F. E. REIMERS ETAL 3,143,423

METHOD AND APPARATUS FoR AGGLOMERATION Filed Oct. 10, 1962 4 Sheets-Sheet 1 w 0004 22/5 16QO0M TEMP) DRY/N6 H07 4m" 2/0 325 a F INVENTORS fRfDfP/CK 5 ka/Mms ATI'Of/VEV 1964 F. E. REIMERS ETAL 3,143,428

METHOD AND APPARATUS FOR AGGLOMERATION Filed Oct. 10, 1962 4 Sheets-Sheet 2 ZE IEPF R I NVE N TOR-S fiQEDM/M Pam/Em 147 7' ORA/EV Aug. 1964 F. E. REIMERS ETAL 3,143,428

METHOD AND APPARATUS FOR AGGLOMERATION Filed Oct. 10, 1962 4 Sheets-Sheet z INVENTORS fkmm/ck E ADE/M593 BY M kv/A/ 0 M/LZER few/M NABORA/Ey zwwiay ATTORNEY g- 1964 F. E. REIMERS ETAL 3,143,428

7 METHOD AND APPARATUS FOR AGGLOMERATION Filed Oct. 10. 1962 4 Sheets-Sheet 4 Tic E Tia. l U I NZ); BY

United states 1 mm: Office This invention relates to improvements in the agglomeration of fine powdered materials, including at least a major portion of sugar, so as to produce agglomerates of relatively low bulk density, and includes an improved agglomeration process and an improved apparatus by which this process may be carried on.

-As such, this application is a continuation-in-part and consolidation of our copending applications, Serial Nos. 132,962 and 132,963, both filed on August 21, 1961, now abandoned.

The invention is applicable to the agglomeration of powdered materials containing at least a major proportion of sugar and in some instances including various other materials, and is particularly advantageous for the agglomeration of various powdered food materials, including not only white or brown sugar per se respectively, but also mixtures of sugars with various other ingredients.

Various processes have been proposed heretofore for the agglomeration of powdered materials by moistening such materials and by agitation of the moistened particles to convert them into agglomerates. Such prior processes have in most instances involved a single step moistening and agglomeration operation or action, wherein a moistening fluid, whether it be atomized water, wet steam or even very humid air, was used not only for moistening, but also for agitating the moistened particles, so as to cause them to contact one another in a way such that the particles agglomerated together. In contrast with these prior processes, the present invention relates to a two-step process in which the moistening of the materials is effected as a first step and the agitation of the particles, such as putting them into a turbulent movement in space, is effective as a second step. In this way, in accordance with the present invention, each step may be carried on under conditions best suited to that step without the inherent limitation of trying to compromise these conditions in order simultaneously to accomplish the other step of the process.

In some of the prior art disclosures, wherein the purpose was to agglomerate food products, such as dry milk, starch, and the like, where the requirements for moisture to agglomerate are many times as great as that of sugar, resort was had to an atomized water spray for the moistening operation. Such operation, when attempted with material which is predominantly sugar, has been found to be impracticable to say the least, and in some instances has resulted in no successful operation whatsoever, in that the requirements for moisture in agglomerating sugar are very much less than those for material such as starch, milk powder and the like.

These principles are exemplified by comparing one of the previously proposed methods as set out in the US patent to ,Grifiin, No. 2,893,871, with the present invention. In this Griflin patent, the powdered material to be agglomerated (milk powders, powdered cocoa, powdered food mixtures, etc.) was supplied downwardly in a sheetlike body into the apex of a trough formed by downwardly directed and convergingjets of moistening fluid (wet steam), which was the sole means for effecting both moistening and agglomeration.

.It is found in accordance with the present invention that improved results can be and are obtainable by sepa- Patented Aug. 4, 1964 rating the agglomeration into two different and successive steps. In the first step a downwardly flowing curtain of the powdered material is subjected to balanced downwardly directed and converging jets of steam or, alternatively, to horizontally directed and balanced opposing jets of steam, in either case solely to efiect moistening of the powdered material. Thereafter, the powdered material is subjected, in a separate agitation stage, to the action of downwardly directed or horizontally directed and opposed jets of either substantially dry steam or air to act on the powder after it has been moistened and to cause it to move in a turbulent manner within an agglomerating zone, so that there will be a sufficient number of collisionsbetween the particles in order that agglomerates thereof will be built up therefrom.

It has been found advantageous in accordance with the present invention to accomplish the moistening of the fine particles of the solid material by the use of upper jets of substantially dry steam with a regulated relatively gentle fiow or velocity, so as to effect moistening without a such turbulent movement of the particles or with only a limited amount of such turbulent movements, that relatively little or no agglomeration shall take place as a result of this moistening step alone. Shortly thereafter, and as a practical matter, a short distance below the zone where the curtain of falling powdered particles is impinged by the upper jets, the particles of this curtain are impinged by a set of lower jets that set up a turbulent motion of the particles so as to cause the agglomeration thereof. The fluid used in the lower jets is supplied into contact with the falling particles of the curtain at a relatively higher velocity than that of the steam in the upper jets, so as to cause the particles to move in a turbulent manner. In accordance with this invention, either substantially dry steam or air may be used in the lower jets;

and further, in the event that steam is used in the lower jets, it may be supplied from the same source as the steam in the upper jets and at the same or some different pressure. In the event that the same pressure steam is supplied, the relative different desired velocities of the upper and lower jets may be attained by the use of appropriate jet nozzles giving relatively lower velocities to the upper jets than to the lower jets.

It is also contemplated in accordance with the present invention that steam at two different pressures, whether from the same or two different sources, may be supplied to the upper and lower jets, with the higher pressure steam applied to the lower jets when steam is used for such jets. It is further contemplated that either the upper or the lower jets or both may be either downwardly inclined or horizontally directed and opposed, it being unnecessary that both be (a) downwardly directed on the one hand; or (b) horizontally directed on the other hand. It is recognized that in the event that steam is used in the lower jets as well as in the upper jets, some additional moistening may and will probably be eifected by the steam from the lower jets. This expedient is particularly useful when the material being handled requires a relatively large amount of moistening but may be used also in other instances as hereinafter set out.

The improved apparatus for carrying out the process of the present invention is one which provides for the supply of the powdered material in the form of a curtain of material of about two inches in thickness and of a width corresponding to the width of the jets, i.e., the steam or air jets which act successively upon both sides of this curtain to effect first, moistening; and second, agglomeration of the particles.

The thickness of the curtain can be varied quite widely. The optimum thickness will depend on a number of variables, such as the rate of feed of the powdered both upper and lower, being of such number and so disposed with respect to the spread of each of the jets and the distances from the jet nozzles to the curtain that the entire width of the curtain was contacted by the several jets collectively on each side of the curtain. A similar arrangement was provided for the lower agitating jets.

In a larger apparatus the curtain of falling powdered material may be several feet in width, with the use of a sutficient number of upper moistening nozzles directed against opposite sides of the curtain to provide jets of steam corresponding to or preferably slightly greater in overall width than the width of the curtain of powdered material, thus providing moistening of the powdered material by the upper jets, and with a number of the lower nozzlesproviding jets of fluid, i.e., air or steam, striking opposite sides of the curtain over the entire width thereof on each side so as to effect a desired agglomeration.

The improved process and apparatus of the present invention enables agglomerates to be prepared from sugar I and mixtures of sugar with other materials as hereinafter set out in greater detail and with a minimum of fine or dust-like particles or overly large aggregates present in the product.

The process enables the production of agglomerates which dissolve or disperse rapidly in water, milk or other dilute aqueous solutions from powdered, water-soluble materials or mixtures of those materials with dispersible 7 materials such as cocoa.

The materials to be treated in accordance with the present invention are predomi-' nantly sugar, either white sugar (sucrose) or brown sugar, as that term is commonly used, or mixtures of sugar (white or brown) with one or more other materials such as cocoa, starch, milk solids and the like.

The invention will be described in detail in connection with the accompanying drawings, which illustrate two forms thereof, but which are to be understood as illustrative and not limiting in character. In the drawings:

FIG. 1 is a view in elevation with parts in section, showing an apparatus according to the invention in 'a somewhat diagrammatic manner;

FIG. 2 is a fragmentary plan view on an enlarged scale, taken on the line 2-2 of FIG. 1;

FIG. 3 is a view in elevation of the nozzlesand their operation similar to, but on a larger scale than that shown in'FIG. 1;

FIGS. 4 and 5 are diagrammatic views showing crosssections of the individual jets taken on the lines 4-4 and 55 respectively of FIG. 3; i

FIG. 6 is a view similar to form of the invention;

FIG. 7 is a view in horizontal section and on an enlarged scale taken on the line 7- -7 of FIG. 6;

FIG. 8 is a view similar to a portion of FIG. 6, but on a substantially enlarged scale, showing the operation and action of the jets; and

FIGS. 9 and 10 are diagrammatic sectional views showing the shape of the jets, taken on the lines 9-9 and 1010 respectively of FIG. 8.

Turningfirst to the form of the invention shown in FIGS. l-5 inclusive, there is illustrated in FIG. 1 an agglomerating chamber 15, which may be either cylindrical or rectangular in cross-section and which is provided with a hopper bottom 16 having an outlet at its lower end from which a discharge chute 17 leads. 7 Steam heating or tracing lines 18 are provided in the walls of FIG. 1 showing a modified the chamber 15 to prevent condensation of steam on the walls by maintaining these walls at a desired elevated temperature. The walls may further be provided with suitable insulation 19 to assist in maintaining them at a desired temperature. Any suitable means may be used for heating the chamber walls, the steam lines 18 being merely one example of means effective for this purpose. One or more suitable vibrators 20, fastened to the wall of the chamber 15 or the hopper bottom portion 16 as particularly shown, may be employed to assist in preventing the accumulation of material on these walls.

In the form of the invention shown in FIGS. 1-3 inclusive, steam pipes 21 and'22 are extended through the vided will therefore depend upon the width of the curtain and the spread afforded by each nozzle in conjunction with the distance between the respective nozzles and the curtain. As shown, the

steam pipes

21 and 22 are connected to vertically-extending branch pipes 23 which in turn connect to horizontally disposed headers 24, FIG. 2, the latter being connected to and carrying a plurality of upper nozzles 25, two such nozzles being shown on each side of the curtain in FIGS. l-3.

Also connected to and carried by the

steam supply pipes

21 and 22 are pipes and fittings 26, which in turn I carry and supply steam to lower nozzles 27, one of which is shown on each side of the curtain. The arrangement shown provides for the moistening of the curtain of solid material particles shown at 28 in FIG. 3, which falls free- .ly by gravity into the apex of the trough formed by

upper steam jets

29 and 30 on one side of the curtain and 31 and 32 on the other side thereof.

A rotary feeder having a supply bin 33, FIGS. 1 and 6, for powdered material is provided with a device 34 for feeding a regular thin sheet of powdered solid material to a rectangular open-top wire basket 35, constructed, for example, of A" mesh screen, and with a width of 2 /2", a height of 2", and a length varying with the width of the curtain of material fed into the agglomerating chamber 15. With a set of nozzles as shown at 25 and 27, the length of such a wire basket may be about 11 inches to discharge a curtain 28 of powdered material .therethrough of around 2 inches in thickness and about 12 inches in width. The basket 35 is vibrated by vibrator 36 to aid in the regular and uniform feeding of the powtop of the chamber 15 and of a size suflicient to permit the curtain 23 of powdered material to pass freely down therethrough. The opening 37 is advantgeously in the form of a sleeve extending partly through the chamber 15 as shown in the drawings, FIGS. 1 and 6, to aid in the directing of the curtain into the desired areas between the nozzles.

After agglomeration, the material being treated passes downwardly through the chute 17 to a combined dryercooler unit consisting of a drying section 38 and a cooling section 39 of a conventional vibrating type. A suitable screen 40 on a supporting frame 41 is vibrated by suitable mechanism 42 and supported by flexible supports 43 in a manner such as to enable the screen to be vibrated to cause the agglomerated material thereon to pass substantially continuously from the inlet at the left as shown in FIGS. 1 and 6 to the outlet at the right as seen in ently believed to be correct.

air after passing through the material being dried being discharged through a pipe 46.

The cooler section 39 has an air supply 47 for cool air or air at ambient temperature with the cooling air discharged from the chamber 15 through a pipe 48. Conveniently, the

pipes

46 and 48 may be adjoined to a common pipe 49 leading to an exhaust fan or the like (not shown). I

The downwardly falling curtain 28 of powdered solid material passes into the apex of a trough formed by the upper jets 29, 3t), 31 and 32, these jets being of sufficient spread so as slightly to overlap one another and also to overlap the horizontal dimensions of the curtain 28 as shown in FIG. 2. Below the point where these jets impinge thereon as illustrated in FIGS. 2 and 3, the cur tain may increase in width somewhat prior to being impinged by the lower jets from the nozzles 27, which are shown at 50 and 51, FIGS. 2 and 3.

The primary function of the upper jets 29-32 inclusive is to moisten the finely divided particles of solid material of the curtain 28. This action is believed to be accomplished by a partial condensation of the steam, of which the upper jets are composed, with the relatively cooler solid material. The solid material is substantially at ambient or room temperature when supplied to the agglomerating chamber. The steam is preferably a substantially dry steam which has been dried by being passed through a suitable liquid-steam separator (not shown), which is interposed between the initial steam supply and the nozzles 25. In addition to this, all steam lines which are shown diagrammatically in the accompanying drawings are preferably insulated in practice.

It is found, however, that a substantial temperature difference must exist between the steam and the solid material, which supports the theory that the moistening action is effected by a partial condensation of the steam. This theory is further supported by the fact thatwhen the solid material is at a relatively high temperature, for example, at about 85 F., the apparatus requires a greater steam supply. This is consistent with the theory above which, when the solid material is at a higher temperature, would indicate that more steam should be supplied in order to get substantially the same amount of moistening. It was also found that when the same apparatus was operated with a solid material feed supply at about 70 F., a relatively smaller amount of steam had to be supplied.

The shape of the jets supplied by the nozzles 25 on the one hand and 27 on the other is best illustrated in FIGS. 4 and 5. As shown, and as it has been found in practice, the amount of steam supplied through the upper nozzles 25,.even when the same steam at the same pressure is supplied to both

nozzles

25 and 27 as in FIGS. 1-3, is such that there will be a lower velocity for the jets of steam supplied through the upper nozzles 25 than through the lower nozzles 27. This is due to the fact that the nozzles are of different types, although both types are commercially available.

As best shown in FIG. 3, the action of the upper jets 29-32 effects a relatively small amount of disruption of the curtain of solid material, so that their action is primarily for moistening and to a very minor extent for causing turbulence in the flow of the solid particles in the curtain 28 under the influence of gravity. When, however, the particles forming the curtain are impinged by the

lower jets

50 and 51, which are at a relatively higher velocity than the upper jets, the premoistened solid particles are caused to move in a turbulent flow within the agglomerating chamber or zone and. thereby there will be created a condition such that a large number of collisions between the particles will occur, which in turn causes agglomeration in accordance with the theory pres- In one example of the apparatus which has been deused substantially as shown in FIG. 1 and which had a diameter of about four feet, the nozzles being arranged symmetrically as shown in FIGS. 2 and 3 and the chute 17 and the inlet opening 37 being of such size that a gentle current of warm at from the drying section could pass upwardly through the agglomeration chamber or zone 15 and out at the upper end of the chamber below the platform shown at 52 and between it and the upper end 53 of the chamber 15.

Following the completion of the drying and cooling of the material, it may be screened to remove oversize and fines if desired.

In the tests aforesaid, measurements of temperature at various points within the agglomeration chamber were made using a thermocouple and with the following results: when steam was supplied at 15 p.s.i.g. to the

pipes

21 and 22 in the form of the invention shown in FIGS. 1-3 inclusive, the temperature measured at the tips of the nozzles 25 was 185 F. and at the point of impingement of the

jets

29, 30, 31 and 32 with at F. With steam at 30 p.s.i.g., the corresponding temperatures at the nozzles 25 was 192 F. and at the point of impingement of the several jets 29-32 with the curtain 28 at F.

With the same apparatus and the same measuring equipment, with 15 p.s.i.g. steam, the temperatures at the lower nozzles 27 was 172 F., and at the point of impingement of the

jets

50 and 51 with the curtain 28, at 147 F. These same measurements for the lower jets with 30 p.s.i.g. steam were respectively 175 F. at the tips of the nozzles 27 and 155 F. at the point of impingement of the

jets

50 and 51 with the curtain 28.

Turning now to the form of the invention shown at FIGS. 6-8 inclusive, it will be seen that there are two essential differences from the form of FIG. 1, first that both the upper and lower jets are horizontally directed and in opposition to one another on both sides of the curtain; and also that there is provided separate supplies for the fluids for the upper and lower jets. These two differences may be employed individually or collectively as variants of the subject matter of the form of FIGS. 1-3; that is, jets may be directed as shown, for example, in FIGS. 1-3 and provided with separate fluid supplies for the upper and lower jets respectively by using the piping illustrated in FIGS. 6-8 and presently to be described; and on the other hand, and as a separate variation, either the upper or the lower or both the upper and lower jets may be horizontally directed as shown for the form of FIGS. 6-8 and the others, if any, inclined as in FIGS. 1-3, in any case, using the same or dilferent supplies of fluids for the upper and lower jets. In both forms of the invention, however, it is contemplated that steam will always be supplied to the upper jets, so that these jets are always used for moistening.

On the other hand, the lower jets which are used for the primary purpose of causing the solid material of the curtain 28 to flow in a turbulent manner in the agglomerating chamber for agglomeration purposes may be supplied with either steam or air; and that steam, if used, may be at a different pressure than the steam supplied to the upper jets and may, for example, be superheated, so as to minimize the amount of additional moistening if the upper jets supply substantially all the moisture desired.

It is found further that when the upper jets at least are directed horizontally at the curtain of falling powdered particles as shown in FIGS. 6-8, there will be a greater dwell of the particles in the area impinged by the jets, so

that lower steam pressures are feasible than in the form of the invention shown in FIGS. 1-3 where inclined jets are used. This has resulted in the consumption of less steam and in further limiting the amount of moistening of the particles of the curtain 28, such limitation being found desirable, for example, where a material consisting "of or high in sucrose is agglomerated. The use of less steam further results in a reduction in the loss of fine the curtain 28,"

nozzles are supplied with particles as dust and reduces the danger-of excess moistening and adherence of the material to the chamber walls.

As shown in FIGS. 6-8, the upper nozzles, again numbered 25, are supplied with steam through headers 54 from

steam supply pipes

55 and 56. It will be understood that the

pipes

55 and 56 are supplied with steam in the same manner as the

pipes

21 and 22 aforesaid, the steam being preferably substantially dry due to having been conducted through a liquid-steam separator (not shown) and further, due to the use of insulation around the steam linesin a conventional manner (not shown).

The lower jet nozzles 27 are also preferably directed horizontally in. this form of the invention, although it is contemplated that inclined upper nozzles with horizontal lower nozzles or vice versa may be used as a combination of the forms of FIGS. 1-3 on the one hand and FIGS. 6-8 onthe other. As shown in FIGS. 6-8, the lower a fluid, which may be either steam or air, through

pipes

57 and 58, which are adapted to be connected to suitable sources of steam or air in accordance with what fluid it is desired to use in these agglomerating nozzles. In the event that steam is to be used, the pipes 57and 58 may be connected respectively to the

pipes

55 and 56; or alternatively, they may be connected to'a source of steam at a different pressure from that supplied to the

pipes

55 and 56, either from a separate source or from the same source and through suitable pressure-reducing valves used in a manner which will be obvious to those skilled in the art from this disclosure in order that the steam pressure through the nozzles 25 shall be the same or less than that through to the nozzles 27 as may be desired.

In the event air is used as the fluid supply for the nozzles 27, it is contemplated that air at any desired temperature may be used, including both air at ambient (room) temperature or air at some elevated temperature incident to passing it through a heater or the like. In this instance alsoyi-t is noted that air is merely one example of a substantially inert gas which may be'used as a supply of fluid to the lower nozzles, other types of inert gases when desired and available being usable in lieu of air. The only requirement in this respect is that the gaseous fluid used must be such that it will not undesirably contami nate the material being handled, which are food products intended for human consumption.

In the form of the invention of FIGS. 6-8 the dispersal of the steam by the upper nozzles 25, so as to insure that it impinges on all the material of the curtain 28, is substantially the same as is the first form of the invention, in

that the nozzles 25 are sufliciently spaced from the curtain and the spread thereof is suificient, as illustrated in FIG. 7, that all the material forming the curtain 28 will be impinged by steam by the upper nozzles 25. As shown, these nozzles provide jets 59, 60 on the left and 61 and 62 on the right, the nozzles 25 lying in substantially the'same horizontal plane and directing their jets horizontally. A cross-section of one of these jets is shown in FIG. 9; The lower nozzles 27 are both in a lower horizontal plane and are directed horizontally so as to provide the

jets

63 and 64, which are also disposed essentially horizontally and in opposition to one another as shown.

It will further be understood that as in the previous form of the invention, all the jets are symmetrically disposed on'both sides of the curtain, so that the effect will be balanced and, in the form of FIGS. 6-8, will be in balanced opposition to one another. This causes a relatively longer dwell of the particles within the moistening area where they are impinged by the jets 59-62 inclusive and in fact some of the particles may tend to move upwardly above the jets to some small extent. However, this action, contrary to the teaching of the Grifiin patent aforesaid, has been found to be very efficient'in moistening the particles and further, to require substantially lower steam pressures and infac't less total steam than is a plane of the curtain.

required in the form of the invention shown in FIGS.

l-5. The lower jets may be either steam or air as stated; and if steam, may be supplied at a different pressure than is supplied to the upper jets. The jet nozzles themselves are of such types as previously set forth, that even if the same steam at the same pressure were supplied to both the upper and

lower jets

25 and 27 respectively, the shape of the jets as shown in FIGS. 9 and 10 incident to the differences in the jet nozzle construction per se would be such as to give a relatively higher velocity for the

lower jets

63 and 64 than for the jets 59-62. Furthermore, as contrasted with some of the expedients used in the prior art, particularly that specifically disclosed in the Griffin Patent No. 2,893,871 aforesaid, the nozzles are sufficiently spaced away from the curtain of solid material particles therebetween that the steam, when it impinges upon the particles forming the curtain 28, is traveling at a relatively low velocity. This is particularly important with respect to the upper jets as it is desired not to cause the curtain 28 to be disrupted and the particles thereof to move in a substantially turbulent manner until after the moistening has been completed and then under the influence of the energy supplied by the lower jet nozzles 27.

The following examples illustrate the carrying out of the process, in the apparatus described, with different materials, but it will be understood that the invention is not limited to the specific materials or apparatus described therein.

In the practice of this invention, the amount of steam employed during agglomeration is such that the moistened articles undergoing agglomeration collectively will not contain more than that amount of water set out in the following table:

Sucrose About 1%. Brown sugar About 2 /z%. Fondant mixture, i.e., 88% sucrose, 12% corn sugar solids having 42% dextrose equivalent Mixtures of sugars with one or more other edible materials selected from a group consisting of cocoa, starch, milk solids, citric acid, gelatin, gum arabic, egg albumin and soluble coffee Pro rata as above as to sugars, plus pro rata for the materials other than s u g a r s based on their respective requirements and p r o p o rtions in the mixture.

Example 1.-P0wdered Sugar (Cane Sugar) About 2%.

Powdered sugar (97.5% minus 200 mesh) at ambient temperature and having an initial moisture content of 0.02 to 0.05%, was fed continuously at the rate of 35Q lbs/hr. from the rotary feeder into the vibrating basket from whence it was dropped in a curtain about 12 inches wide by about 2 inches thick into a moistening zone of steam as shown in FIGS. l-3 inclusive and supplied by two nozzles on each side of the curtain, 6 inches apart horizontally in a direction parallel to the central vertical The nozzles, placed at 6 inches from the central plane of the curtain, were pointed downward at a 45 angle and were fed dry steam at 20 p.s.i.g.

The moistened sugar passed downward into the agglomeration zone created by the lower nozzle on each side. These nozzles delivered flat jets of steam having a agglomeration.

n addition of water, fruit juices through the outlet opening of the chamber cone and into the inclined chute leading to the drying section of the combined dryer-cooler unit. After drying and cooling, the agglomerates were screened to yield a fraction of minus 8 mesh and plus 48 mesh amounting to about 85% of the agglomerates. The oversize fraction, plus 8 mesh, amounted to about 2% and the fines fraction, minus 48 mesh, amounted to 13%. As the oversize and fines fractions were as dry as the product fraction (about 0.05% moisture), they could be ground and recycled to re- The product fraction (8 mesh; +48 mesh) had a bulk density of 21 lbs/ft. and consisted of firm agglomerates that were uniform in hardness and did not break down into a powder when subjected to packaging in boxes or bags followed by handling such as palletizing and shipping. The agglomerates dissolved rapidly in water without forming floating sticky masses.

Example 2.Fondant Sugar (Cane Sugar and Corn Syrup Solids) whence it was dropped in a curtain about 12 inches wide by about 2 inches thick into the moistening and agglomerating zones wherein the apparatus was arranged as described in Example 1. At a pressure of 9 p.s.i.g. of dry steam at the entrance of the nozzles, the steam emitted was in sufiicient quantity from the nozzles 25 for moistening and at suflicient velocity from the nozzles 27 for agglomeration. The moistened and agglomerated material passing from the agglomeration zone through the chute 17 had a moisture content of about 2%.

The agglomerated material, after passing through the dryer-cooler (320 F. hot air, 72 F. cooling air) was screened into thefollowing fractions: plus 8 mesh, 1% by weight; minus 8, plus 48 mesh, 91% by weight; minus 48 mesh, 8% by weight. 1

Both the unscreened and the screened (-8 mesh; +48 mesh) materials were completely free of grittiness. A mixture of 500 grams of the resulting agglomerates with 70 grams of water was converted in a small Hobart mixer into a smooth icing base or fondant in 3 minutes. This fondant or icing base was comparable in quality to cooked commercial fondant preparations.

This material has the following advantages: it can be prepared rapidly by mixing with water (cold or hot) either by hand or by machine; it can be made into fruit I fondants and fruit icing bases by mixing with fruit juices or pulped fruits; the fondant can be used directly in confectionery and baking processes without the necessity of aging or tempering as is true with cooked fondants; it is possible to readjust the consistency of the fondants by etc., or additional agglomerated materials; the icing or fondant material processes better aging properties and increased resistance to impairment in quality resulting from adverse temperature and humidity. conditions; and it can be made into bakery glazes by usingup to 25% water and stabilizing materials.

Example 3.Sugar-Gelat in Mixture gelatin commonly used in fruit flavored gelatin des air, 77 F. cooling air) was divided into the The powder, having an initial moisture content of about 0.8%, was fed at a rate of 350 lbs/hr. in a curtain about 12 inches wide by about 2 inches thick.

The apparatus used was as described in Example 1, except that the nozzles were pointed downward at about and the steam supplied to the nozzles was at 35 p.s.1.g.

The moist agglomerates containing about 1.5% water were dried with air at about 275-280 F., cooled, and screened to obtain fractions of 4.0% on 8 mesh, 80.0% through 8, on 48 mesh, and 16.0% through 48 mesh. The dry material had a moisture content of 0.5% and a bulk density of 17.0 lbs./ft.

This material has excellent dispersion and anti-caking 'qualities. It also increases the strength of the gel obtained with a given bloom strength gelatin, especially in preparations using temperatures of water ranging from 100 F. to 160 F.

Example 4.-Br0 wn Sugar The starting material was a brown sugar dried to about 0.4% initial moisture and of the following composition: sucose, 92.0%; invert, 3.8%; moisture, 0.4%; ash, 1.90%; and undetermined, 1.9%. This material was ground to a fineness of 97% minus 200 mesh and agglomerated in the manner decribed in Example 1. The steam was sup- 'plied to the nozzles at 20 p.s.i.g. and the agglomerates 30 l leaving the zone of turbulence had a moisture content of 1.7%. In other tests run on different samples of brown sugar, moisture contents of agglomerates leaving the zone of turbulence ranged from about 1.7% to about 2.5%.

The material leaving the dryer-cooler (310 F. drying following plus 8 mesh, 9.0% by weight; by weight; minus 48 mesh, 6.0%

three screen fractions: --8, +48 mesh, 85.0% by weight.

The final dry material had a moisture content of 0.3%, a uniform light brown color, a bulk density of 21.5 lbs/ft. and consisted of. crisp agglomerates quite free of dust. This product, when subjected to a humid atmosphere of 85 F. dry bulb and 63% relative humidity followed by drying in a desiccator containing anhydrous calcium chloride, exhibited good resistance to caking. This is a great improvement over the caking tendencies of the powdered feed sugar and the original dried brown sugar from which the powdered feed had been prepared by grinding.

' ing followed by The agglomerated sugar dissolves rapidly in cold water and lends itself well to dry handling (conveying) or dry proportioning.

grinding to a fineness of 100% minus 325 mesh. The composition of the mixture was as follows, the percentages being by weight: cane sugar 82.0%;

corn syrup solids (42% dextrose equivalent) 12.0%; salt 0.2%; gelatin 1.2%; gum arabic 1.1%; egg albumin 3.5%.

The mixture was fed to the agglomeration unit as described in Example 1 and as shown in FIGS. 1-5 at the rate of 300 lbs. per hour and the general procedure described in Example 1 was followed with the steam supplied to the nozzles at 23 p.s.i.g. The moisture content of this material as agglomerated and when it was leaving the agglomeration zone was about 2.4%. In certain 7 other tests made on similar compositions the results were as follows: (a) when the corn styrup solids of the above composition were replaced by dextrose, the moisture content of the aggregates were found to vary between about 2.1% and about 2.4%; (b) when the gelatin of the above composition was replaced by pectin, moisture contents of the agglomerates in several tests were found to range between about 2.3% and 2.9%. After drying the moist agglomerates with hot air at 275 F. and cooling with ambient air at 73 F., the material had a moisture content of 0.15%. Others of the icing mixtures hereinabove referred to which were tested had final moisture contents ranging from about 0.3% to about 0.6% and averaged about 0.5%. Screening separated the material into the following fractions by weight: plus 8 mesh 5.0%; minus 8 mesh, plus-48 mesh 81.0%; minus 48 mesh 14.0%.

The bulk density was 24.0 lbs./ft. On subjecting the material to humid warm air of 85 vF. dry bulb and 63% relative humidity followed by drying, excellent resistance to caking was exhibited when compared to the unagglomerated feed mixture.

With this agglomerated product, it is possible to prepare smooth, whipped icings using lukewarm water (130-140 F.). This represents a marked advantage over present commercial icing materials, which require the use of boiling water. With this material it is possible to prepare flavored icings using fruit juices to hydrate the agglomerated materials.

Example 6Q-Sugar-Citric Acid Mixture erated material into the following fractions, by weight:

plus 8 mesh 22.0%; minus 8 mesh, plus 48 mesh 70.0%; minus 48 mesh 8.0%. Because of its free-flowing properties, this agglomerated product can be advantageously used in dried gelatin dessert mixtures and dry flavored I drink preparations.

Example 7.-Sluble Cofiee and Sugar Mixture A mixture of 80% by weight of sugar and 20% by weight of soluble coifee was ground to a fineness of 97.5 %v minus 200 mesh and was agglomerated in apparatus as shown in FIGS. 1-5 and in the manner described in Example 1 with a feed rate of about 280 lbs/hr. and with a steam pressure of 20 p.s.i.g.

The agglomerated material after drying and screening gave the following fractions: 71% minus 8 mesh, plus 48 mesh; 23% minus 48 mesh; and 6% plus 8 mesh.

Example 8.Sugar-C0c0a Mixture A mixture of 60% sugar, 20% cocoa and 20% whole dry milk having an initial moisture content of about 2.1% was ground to a particle size approximating 97 /2 minus 200 mesh (equivalent to the particle size of so-called 10X sugar). This mixture was supplied to an agglomerating apparatus substantially as shown and described with respect to FIGS. 1-5 and as set out in some detail in Example 1 above. Steam was supplied to both the upper and lower nozzles at a pressure of 42 p.s.i.g.,resulting in the moistening and agglomeration of this material. The agglomerated material passing from the agglomeration zone to the drying zone had a moisture content of about 4% to about 5%, these values being obtained from a number of samples taken from time to time during the course of the tests. The aggregates after drying had a moisture content of about 2.6% and were tested and found satisfactory for rapid mixing in the making of cocoa drinks. This material was successfully and rapidly dispersed even i in cold water.

Further tests were made using downwardly inclined nozzles as in FIGS. 1 and 3, but with separate supplies of fluids to the upper and lower nozzles as in FIGS.

6-8. With this construction and using steam in the upper nozzles and air in the lower nozzles, successful agglomerations were made using fondant sugars as in Example 2 hereinabove and sugar-citric acid mixtures as in Example 6. The results were considered completely successful.

In the above examples, steam was supplied to the lower agglomerating nozzles and the use of steam has the advantage of preventing the moistened surfaces of the particles from drying during agglomeration and adds somewhat to the moisture on the surface of the particles. Instead of using steam, air can be supplied to the lower nozzles to produce turbulence for agglomeration and this prevents excessive moistening and is advantageous in the treatment of certain materials, such as highly hygroscopic materials.

Inthe above examples the same pressure was applied to both upper and lower nozzles but, for certain applications, it is advantageous to use different pressures, since the steam pressure required for moistening may not be that required for optimum agglomerating conditions.

The above examples describe the carrying out of the process with various materials and mixtures, but other materials can also be agglomerated by the process and apparatus of the invention to produce products of low bulk density. The materials susceptible to agglomeration as described are those rendered adhesive by the application of moisture, or mixtures containing such materials.

The bulk density of the products can be somewhat varied but, in general, it will be around one-half, more or less, of that of the unground starting material. Agglomerated products can readily be produced with a bulk density varying with the particular material and ranging from 16 to 28 pounds per cubic foot and the bulk density of specific materials can be somewhat increased or decreased, as desired.

Example 9.F0ndant Sugar (Cane Sugar and Corn Syrup Solids) A mixture of 88% by weight of cane sugar and 12% of corn syrup solids (42% dextrose equivalent) was ground to less than 44 microns minus 325 mesh). This powder was fed from the rotary feeder 33 at the rate of 325 lbs. per hour into the vibrating basket 35 from whence it was dropped as shown in FIGS. 6-8 inclusive in a curtain about 12 inches wide by about 2 inches thick into a moistening zone of steam supplied by two nozzles on each side of the curtain, 6 inches apart in a horizontal plane measured parallel to the plane of the curtain and at a horizontal distance of approximately 9% inches from the central plane of the falling curtain of sugar. These nozzles were pointed horizontally and caused the steam issuing therefrom to have exactly opposing and impinging patterns.

The moistened sugar passed downward into an agglomeration zone created by steam emerging from two directly opposing horizontal nozzles 27, FIGS. 6-8 and discharged at suificiently high velocity to create turbulence effecting agglomeration. Each of the nozzles 27 was placed 6 inches below the midpoint between the upper nozzles and about 10% inches from the central plane of the curtain of solid material. All nozzles were fed dry steam from a common source.

At a pressure of from 4-5 p.s.i.g. of dry steam at the I entrance of the upper and lower nozzles, excellent agglomeration was obtained.

The agglomerated material having a moisture content of about 2%, after passing through the vibrating dryercooler (320 F. hot air, 72 F. cooling air), was screened into the following fractions, by Weight: plus.8 mesh 9%; minus 8, plus 48 mesh 82%; minus 48 mesh 9%.

Both the unscreened and the screened (8; +48 mesh) materials were completely free of grittiness. A mixture of 500 grams of the minus 8 plus 48 mesh fraction of the agglomerates with 70 grams of water was converted in a small Hobart mixer into a smooth icing base or fondant qualities.

in 3 minutes. This fondant or icing base was comparable in quality to cooked commercial fondant preparations.

This material has the following advantages: it can be prepared rapidly by mixing with water (cold or hot) either by hand or by machine; it can be made into fruit .fondants and fruit icing bases by mixing with fruit juices .or pulped fruits; the fondant can be used directly in con-' fectionery and baking processes without the necessity of aging or tempering as is true with cooked fondants; it is possible to readjust the consistency of the fondants by addition of water, fruit juices, etc., or additional agglomerated material; the icing or fond-ant material possesses excellent aging properties and good resistance to impairment in quality resulting from adverse temperature and .humidity conditions; and it can be made into bakery glazes by using up to 25% water and stabilizing materials. Example 10.Pwdered Sugar (Cane Sugar) Powdered sugar (97.5% minus 200 mesh) was treated as in Example9, with steam supplied at 9 p.s.i.g. to the upper nozzles 25, FIGS. 6-8 and at 12 p.s.i.g. to the lower nozzles 27, FIGS. 6-8. Good agglomeration was achieved with little or no evidence of grittiness (crystallizing) of sugar, and the agglomerator walls remained free of adher- Example 11.'Sugar-'Gelatin Mixture A mixture of 93% by weight cane sugarand 7% of 170 bloom bone gelatin, the approximate concentration of gelatin commonly used in fruit flavored gelatin desserts, was ground and agglomerated as described in Example 9 p with steam supplied to apparatus as shown in FIGS. 6-8

at a pressure of 13 p.s.i.g. to both the upper and lower nozzles. Product yields of 85% were obtained of the fraction minus 8 mesh and plus 48 mesh.

This material has excellent dispersion and anti-caking It also increases the strength of gel obtained With a given bloom strength gelatin especially in preparations using temperatures of water ranging from 100 F. to 160 F.

Example 12.'Brown Sugar The starting material was a brown sugardried to about 0.4% moisture and of the following composition: sucrose, 92.0%; invert, 3.8%; moisture, 0.4%; ash, 1.9%; and undetermined, 1.9% The material was ground to a fineness of 97% minus 200 mesh and agglomerated in the manner described in Example 9. The steam was supplied to both the upper and

lower nozzles

25 and 27, FIGS. 6-8, at 15 p.s.i.g. The agglomerates passing from the agglomerating zone to the drying zone had a moisture content of about 2.3%. The material was thereafter dried to a moisture content of about 0.5%. A product yield, through 8 mesh and on a 48 mesh, of 35% was obtained.

This product, when subjected to a humid atmosphere of 85 F. dry bulb and 63% relative humidity followed by drying in a desiccator containing anhydrous calcium chloride, exhibited good resistance to caking. This is a great improvement over the caking tendencies of the powdered feed sugar and the original dried brownsugar from which the powdered feed had been prepared by grinding.

The agglomerated sugar dissolves rapidly in cold water and lends itself well to dry handling (conveying) or dry proportioning.

Example 13.Sugar-Citric Acid Mixture A mixture of 90% cane sugar-% citric acid' previpreviously blended in a ribbon mixer ously blended in a ribbon mixer and ground to a fineness of 97% minus 200 mesh was agglomerated as described in Example 9 supplying steam at 15 p.s.i.g. to both the upper and lower sets of nozzles.

After drying with 270 F. air and cooling with F. air, screening produced the following fractions of agglomerated material, by weight: plus 8 mesh 0.5%; minus 8 mesh, plus 48 mesh minus 48 mesh 45%.

Because of its free-flowing properties, this agglomerated product can be advantageously used in dried gelatin dessert mixtures and dry flavored drink preparations.

Example 14.-Sugar-C0c0a Mix had a total moisture content as it passed from the agglomerate zone to the drying zone of about 2 /23% (samples at dilferent times during the run varying in this range). After subsequent drying with 300 F. air and cooling with 85 F. air, screen analysis showed the following fractions of agglomerated materials: plus 8 mesh 1%; minus 8 mesh, plus 48 mesh 92% minus 48 mesh 7%.

properties and remains in suspension for a much longer This agglomerated mixture has excellent dispersing time than the unagglomerated feed material.

The agglomerated material dispersed in 20 C. water in 25 seconds as against two minutes for the unagglomerated material. A suspension of 20 grams of agglomerated and unagglomerated materials in cubic centimeters of 27 C. water was prepared and allowed to settle in 250 cc. beakers and the sediment measured at 5 minute intervals. After 5 minutes the unagglomerated material showed 7 millimeters depth of settled material on the bottom of the beaker versus none for the agglomerated material. After 15 minutes the unagglomerated material showed 8 millimeters of settled material versus 2 millimeters for the agglomerated material.

Example l5.-Sugar-C0c0a-Starch Mixture A sugar, cocoa, starch mixture as used in commercial chocolate pudding and containing about 66 /2% sugar, 22% starch, 11% cocoa, /2% salt and minor amount flavoring was ground to a fineness of 98% through a 200 mesh screen and agglomerated in apparatus as shown in FIGS. 68 using a feed rate of 275 lbs. per hour as described in Example 9.

Supplying steam at 40 p.s.i.g. to both upper and lower nozzles, a good quality, firm agglomerate was obtained. After drying with 300 F. air and cooling with 85 F. air, this material had screen fraetions as follows: on 8 mesh, 0.6%; through 8 mesh and on 48 mesh, 96.0%; minus 48 mesh, 3.4%.

As compared with the unground unagglomerated mixture, the agglomerated material exhibited improved dispersibility in aqueous liquid and had a bulk density of about 20.5 lbs/ft. versus a bulk density of about 40 lbs./ ft. for the unground, unagglomerated mixture.

Example 16.-Sugar-Skim Milk Powder Mixture A mixture of 50% sucrose and 50% skim milk powder and ground to a fineness of 97% through a 200 mesh screen was fed at the rate of 300 lbs. per hour between the upper and lower banks of nozzles supplied With dry steam at 45 p.s.i.g.

The starting material had a moisture content of about This material, due to its relatively high content of skim milk powder, takes up a very substantial amount of moisture and, therefore, requires substantial steam pressure when using substantially dry steam in accordance with I ample 10, different the present invention. The moistened material passing from the agglomerating zone to the drying zone had a moisture content in the range of about 5.1 to 7.2%, these figures being the results of a number of tests throughout the run. Good agglomeration was achieved and after drying with 305 F. air and cooling with 85 F. air, screening produced the following fractions: on 8 mesh, 10%; tlgough 8 mesh and plus 48 mesh, 70%; minus 48 mesh, 2

The agglomerated product showed excellent wetting and dispersing qualities whereas the original mixture was diflicult to wet and disperse.

Example 17.-Fondant Sugar (Cane Sugar and Corn Syrup Solids) A mixture of 88% sucrose and 12% corn syrup solids ground to a fineness of 100% through a 325 mesh screen was fed at the rate of 325 lbs. per hour between the horizontallyopposed nozzles delivering a pattern as illustrated in FIGS. 6-8. At a nozzle pressure of 11 p.s.i.g. of dry steam, good agglomeration was achieved.

After drying with 315 F. air and cooling with 85 F. air, screening produced the following fractions: on 8 mesh, 3.5%; through -8 mesh and minus 48 mesh, 88.0%; minus 48 mesh, 8.5%.

The product was comparable in quality to that produced in Example 9.

In Examples 9 to 17, steam was supplied to both sets of nozzles. Supplying steam to the agglomerating nozzles affords the advantage of adding moisture to particles not sufliciently moistened by the moistening jets and of preventing the moistened surfaces of the particles from drying before agglomeration is complete.

Instead of using steam, air may be supplied to the lower agglomerating nozzles 27 in the treatment of certain materials, such as those which are highly hygroscopic. The use of air prevents excessive moistening of the particles, which would interfere with the production of satisfactory agglomerates and cause adhesion of the particles to the chamber walls.

The following example illustrates the use of air through the lower nozzles for agitation and agglomeration.

Example 18.Crn Syrup Solids variance from horizontal is permissible. For example, we

have also used nozzles tilted upwardly at around 45 above the horizontal, and have found that satisfactory moistening and agglomeration can be accomplished; The following example illustrates the process carried out with the nozzles tilted upwardly at 4-5.

Example 19.-F0ndant Sugar-Sugar and Corn Syrup Solids Using the mixture referred to in Example 9 and with the steam supplied to both the upper and lower nozzles at 8 p.s.i.g., a good quality product was produced with 83% minus 8 plus 48 mesh,'with 14% fines and 3% oversize.

In some of the examples described the same pressures were applied to both upper and lower nozzles, but in the agglomeration of certain materials, as described in Expressures are employed, since the steam pressure required for moistening is not that required for optimum agglomerating conditions.

The bulk density of the products can be somewhat varied, but in general it will be around one-half, more or less, of that of the original starting material. Agglomerated products can be readily produced with bulk densities pulverized sugar, which comprises 15 varying with the particular material and ranging from 16 to 28 pounds per cubic foot and the bulk density of specific materials can be somewhat increased or decreased as desired.

While there has been herein shown and described two dilferent examples of apparatus embodying the present invention and various methods using these or some combination of this apparatus, other variations both of apparatus and of method, and all within or similar to the teachings given hereinabove will occur to those skilled in the art from the foregoing disclosure. We do not wish to be limited, therefore, except by the scope of the appended claims, which are to be construed validly as broadly as the state of the art permits.

What is claimed:

1. The method of producing a dry, free-flowing agglomerated edible material from fine particles of solid edible material including at least a major proportion of fine the steps of dropping the fine solid material to be agglomerated at substantially ambient temperature in the form of a substantially continuous curtain of fine particles falling freely and uninterruptedly through an agglomerating zone,

directing a plurality of jets of substantially dry steam at said curtain of fine particles in suflicient number and spread of the respective jets so as to cover the entire area of said curtain with steam, and thereby moistening the particles of material making up said curtain, said steam being at a temperature substantially higher than that of said curtain of fine particles against which said steam is directed,

almost immediately thereafter subjecting the thus moistened particles of material of said curtain, while such particles are still falling freely in said zone, to the action of a second set of jets of at least one fluid, selected from the class consisting of air and substantially dry steam, said fluid being delivered at a sufficient velocity to impart turbulence to said moistened particles in said zone and thereby cause them to agglomerate while still unsupported except by the turbulent fluid in said zone, so as to form agglomerates, said jets being symmetrically disposed on both sides of said curtain of fine particles and the amount of steam supplied by said jets to said curtain of fine particles being suflicient to moisten said fine particles whereby the moistened particles are agglomerable on contact with said second set of jets,

and thereafter drying said agglomerates to form a dry,

free-flowing material. 2. The method of producing a dry, free-flowing agglomerated edible material from fine particles of solid edible material including at least a major proportion of fine pulverized sugar, which comprises the steps of dropping the fine solid material to be agglomerated at substantially ambient temperatures in the form of a substantially continuous curtain of fine particles falling freely and uninterruptedly through an agglomerating zone, 7

directing a plurality of jets of substantially dry steam at said curtain of fine particles in sufficient number and spread of the respective jets so as to cover the entire area of said curtain with steam, and thereby moistening the particles of material making up said curtain, said steam being at a temperature substantially higher than that of said curtain of fine particles against which said steam is directed,

almost immediately thereafter subjecting the'thus moistened particles of material of said curtain, while such particles are still falling freely in said zone, to the action of a second set of jets of at least one fluid, selected from the class consisting of air and substantially dry steam, said fluid being delivered at a sufficient velocity to impart turbulence to said moistened particles in said zone and thereby cause them to agglomerate while still unsupported except by the turbulent fluid in said zone, so as to form agglom erates, said jets being symmetrically disposed on both sides of said curtain of fine particles,

controlling the amount of moistening of the solid particles as aforesaid so that the moistened particles collectively will contain not more than that amount of water set out in the following table:

Sucrose About 1% Brown sugar About 2 /z% Fondant mixture, i.e., 88%

sucrose, 12% corn sugar solids ,having, 42%. dextrose equivalent Mixtures of sugars with materials selected from a group consisting of cocoa, starch, milk solids, citric acid, gelatin, gum arabic, egg albumin and soluble coffee a Pro rata as above as to sugars, plus pro rata for materials other than sugars based on their respective requirements and proportions in the mixture About 2% the controlling of the amount of moisture added to V the solid material being effected by controlling the rate of steam supply to the agglomerating zone in view of the temperature difference between the solid material and the steam as they are supplied respec tively to the agglomerating zone,

and thereafter drying said agglomerates to form a dry,

free-flowing material.

3. The method of producing a dry, free-flowing agglomerated edible material from fine particles of solid edible material including at least a major proportion of fine pulverized sugar, which comprises the steps ofdropping the fine solid material to be agglomerated at substantially ambient temperatures in the form of a substantially continuous curtain of fine particles falling freely and uninterruptedly through an agglomcrating zone,"

directing a plurality of jets of substantially dry steam at'said curtain'of fine particles in sufiicient number and spread of the respective jets so as to cover the entire area of said curtain with steam, and thereby moistening the particles of material making up said curtain, said steam being at a temperature substantially higher than that of said curtain of fine particles against which said steam is directed, almost immediately thereafter, subjecting the thus moistened particles of material of said curtain, While such particles are still falling freely in said zone, to the action of a second set of jets of at least one fluid selected from the class consisting of air and substantially dry steam, said fluid being delivered at a sufficient velocity to impart turbulence to said moistened particles in said zone and thereby cause them to agglomerate while still unsupported except by the tubulent fluid in said zone so as to form agglomerates, said jets being symmetrically disposed on both sides of said curtain of fine particles, controlling the amount of moistcning of the solid particles as aforesaid so that the moistened particles collectively will contain not more than that amount of water set out in the following table:

Sucrose About 1% Brown sugars About 2 /z% Fondant mixture, i.e., 80%

sucrose, 12% corn sugar solids having 42% dextrose equivalent About 2% Mixtures of sugars with ma-l .terial selected from the group consisting of cocoa,

starch, milk solids, citric acid, gelatin, gum arabic, egg albumin and soluble coffee Pro rata as above as to sugars, plus pro rata for materials other than sugars based on their respective requirements and proportions in the mixture and thereafter drying said agglomerates to form a dry,

free-flowing material.

4. The method according to claim 3, in which the fluid of said second set of jets is substantially dry steam.

' 5. The method according to claim 3, in which said second set of jets supplied substantially dry steam from a source which is common with the supply of steam to the first-named set of jets, the steam being supplied to both jets at the same pressure, but being supplied by those jets into contact with the solid material of said curtain at a relatively lower velocity by the first-named set of jets and at a relatively higher velocity by the second set of jets as determined by different types of jet-forming nozzles.

'6. The method in accordance with claim 3, in which the fluid of said second set of jets is air.

7. The method in accordance with claim 3, in which said curtain of fine solid material falls in and adjacent. to a substantially vertical plane;

and in which the first-named plurality of jets is di- 'rected downwardly from opposite sides of and toward said curtain from points equi-distant from said plane and at corresponding angles to the vertical, so that the material in said cutain falls into the apex of a trough formed between the two balanced, con{ 7 verging and colliding jets of steam.

8. The method in accordance with claim 7, in which the second set of jets are directed from points uniformly spaced on opposite sides of said curtain and are directed downwardly toward said plane in a similar manner, so that the falling solid material moistened by the jets of the first set falls into the apex of a V-trough formed by the second set of jets.

9. The method in accordance with claim 3, in which the solid particles of said curtain fall downwardly by gravity through said agglomerating zone and are engaged in said zone by the first-named plurality of jets, which are symmetrically disposed as to said curtain and directed substantially horizontally at said curtain from opposite sides thereof.

10. The method in accordance with claim 9, in which the jets of said second set are directed horizontally at the material of said curtain a short distance below the place where such material is engaged by the jets of the first set and symmetrically from both sides thereof, the jets of said second set being substantially balanced and in direct opposition to one another on opposite sides of said curtain.

11. Apparatus for producing a dry free-flowing agglomerated, edible material from fine particles of solid material, including at least a major proportion of fine pulverized sugar,

comprising means providing an agglomerating chamber which is substantially closed except for openings in the top and bottom thereof,

means for substantially continuously supplying said fine particles of solid material through the opening in the top of said chamber-providing means in the form of a freely falling curtain, which is uninterrupted by any solid parts during its passage through said chamber,

E9 means including a plurality of jet nozzles symmetrically disposed with respect to and on oppositeisides of said curtain for supplying substantially dry steam to said chamber in such directions and in jets of such spread as to impinge on the entire'width of both sides of said curtain, so as to moisten the particles of solid material thereof, other means including a second plurality of jet nozzles symmetrically disposed with respect to and on opposite sides of said curtain and directed at the falling material of said curtain at a level lower than the place where the jets from the first-named plurality of nozzles impinge on said curtain and again of such nu'mbendisposition and spread of jets as to engage the entire area of both sides of said curtain, said second plurality of jet nozzles acting to direct at least one fluid, which is selected from the group consisting of substantially dry steam and air, at a velocity suflicient to impart turbulence to theparticles of solid material of said curtain, so as to cause'said particles to agglomerate together prior to their leaving said chamber, said agglomerated particles thereafter passing out of said chamber through the opening at the bottom thereof,

the first-named jet nozzles being of such type as con-: trasted with said second plurality of jet nozzles that when both are supplied with the same fluid from a common source and at a single predetermined pressure, the velocity of the fluid from said first-namedjet nozzles at the time it contacts said particles of solid material of said curtainwill be substantially less than the velocity of the fluid from the secondnamed-jet nozzles upon contact with said solid material of said curtain, t and means for thereafter drying the agglomerated particles passing out of said chamber to form a'dry, freeflowing material. 12..Apparatus in accordance with claim 11, further comprising separate means for supplying steam to the first-named plurality of jet nozzles, and for supplying a fluid as aforesaid to; said second plurality of jet nozzles, whereby said second; plurality of jet nozzles may be selectively provided with steam or air and in either case, at a pressure predetermined in a manner independent of the pressure of steam supplied to the first-named plurality of jet nozzles.

13. Apparatus in accordance with claim 11, in which the nozzles of the first-named plurality of jetnozzles arev inclined'downwardly to direct steam therefrom at said freely-falling curtain of solid material atacute angles to the first-named plurality of jet nozzles are directed-herb 210 the horizontal, so that the solid material falls into the apex of a trough provided by the downwardly directed jets from said first-named pluralityofjet nozzles.

14. Apparatus in accordance with claim 13, wherein said second plurality of-jet nozzles are also disposed so that the jets therefrom are directed in downwardly-inclined paths'to engage the falling material below'the point where said material is impinged by the jets from the first-named plurality of jet nozzles.

15. Apparatus in accordance with claim 11, in which zontally, so as to direct jets of steam therefrom horizontally in opposition to one another at the curtain ofsolid material falling therebetween. I

16. Apparatus in accordance with claim 15, in which said second plurality of jet nozzles are also directedhori zontally, so that the jets of fluid therefrom will impinge upon the falling particles of solid material of said curtain at a point below that where such particles were impinged by the steam from the first-named plurality of jet nozzles.

17. Apparatus in accordance with claim 11, further comprising means for maintaining the walls of said agglomerating chamber at a predetermined elevated temperature, so as to minimize the tendency for the condensation of steam on said walls and to minimize the tendency forsolid particles to adhere thereto.

18; Apparatus in accordance with claim 17, in which said means for thereafter drying the agglomerated particles comprises means by which warm air is blown through a bed of such particles;

and in which the lower end of said chamber is tapered to form a passage leading from said chamber to said drying means and providing the outlet from said chamber for solid particles, said outlet further providing a conduit through which some warm air from saiddrying means can pass through said chamber, said warm air thereafter passing out of said'chamber through said opening in the top thereof.

References Cited in the file of this patent UNITED STATES PATENTS 1,185,623 Boss June 6, 1 916 2,097,914 Cooper et al. Nov. 2, 1937 2,576,952 Lowe et al. Dec. 4,- 1951 2,707,690 Pearson May 3,195 2,856,290 Peebles Oct. 14, 1958 2,900,256 Scott- Aug. 18, 1959 FOREIGN PATENTS 926,072 1955

Claims

1. THE METHOD OF PRODUCING A DRY, FREE-FLOWING AGGLOMERATED EDIBLE MATERIAL FROM FINE PARTILCES OF SOLID EDIBLE MATERIAL INCLUDING AT LEAST A MAJOR PROPORTION OF FINE PULVERIZED, SHICH COMPRISES THE STEPS OF DROPPING THE FINE SOLID MATERIAL TO BE AGGLOMERATED AT SUBSTANTIALLY AMBIENT TEMPERATURE IN THE FORM OF A SUBSTANTIALLY CONTINUOUS CURTAIN OF FINE PARTICLES FALLING FREELY AND UNINTERRUPTEDLY THROUGH AN AGGLOMERATING ZONE, DIRECTING A PLURALITY OF JETS OF SUBSTANTIALLY DRY STEAM AT SIAD CURTAIN OF FINE PARTICLES IN SUFFICIENT NUMBER AND SPREAD OF THE RESPECTIVE JETS SO AS TO COVER THE ENTIRE AREA OF SAID CURTAIN WITH STEAM, AND THEREBY MOISTENING THE PARTICLES OF MATERIAL MAKING UP SAID CURTAIN SAID STEAM BEING AT A TEMPERATURE SUBSTANTIALLY HIGHER THAN THAT OF SAID CURTAIN OF FINE PARTICLES AGAINST WHICH SAID STEAM IS DIRECTED, ALMOST IMMEDIATELY THEREAFTER SUBJECTING THE THUS MOISTENED PARTICLES OF MATERIAL OF SAID CURTAIN WHILE SUCH PARTICLES ARE STILL FALLING FEELY IN SAID ZONE, TO THE ACTION FROM THE CLASS CONSISTING OF AIR AND SUBSTANTIALLY DRY STEAM, SAID FLUID BEING DELIVERED AT A SUFFICIENT VELOCITY TO IMPART TURBULENCE TO SAID MOISTENED PARTICLES IN SAID ZONE AND THEREBY CAUSE THEM TO AGGLOMERATE WHILE STILL UNSUPPORTED EXCEPT BY THE TURBULENT FLUID IN SAID ZONE, SO AS TO FORM AGGLOMERATES, SAID JETS BEING SYMMETRICALLY DISPOSED ON BOTH SIDES OF SAID CURTAIN OF FINE PARTICLES AND THE AMOUNT OF STEAM SUPPLIED BY SAID JETS TO SAID CURTAIN OF FINE PARTICLES BEING SUFFICIENT TO MOISTEN SAID FINE PARTICLES WHEREBY THE MOISTENED PARTICLES ARE AGGLOMERABLE ON CONTACT WITH SAID SECOND SET OF JETS, AND THEREAFTER DRYING SAID AGGLOMERATES TO FORM A DRY, FREE-FLOWING MATERIAL.