EP0221999A1 - Method and apparatus for removing volatiles from or dehydrating liquid products - Google Patents

Abstract

Methods and devices are used in particular for dehydrating products such as corn syrups, fruit and vegetable extracts, dairy products or other products sensitive to temperature or difficult to process. The methods and apparatus include using a pulse burner (24) to generate a high temperature, acoustically resonant atmosphere in a dewatering chamber (22), and vaporizing the raw materials in the chamber (22). The droplets of the raw materials dehydrate as they pass through the chamber (22) and are then collected by suitable devices (68, 84, 92). The temperature and the residence time of the raw materials in the chamber (22) are adjusted to prevent the product from degrading. When the dehydrated product is hygroscopic, processing aids can be added to reduce its hygroscopic tendency.

Description

METHOD AND APPARATUS FOR REMOVING VOLATILES FROM OR

DEHYDRATING LIQUID PRODUCTS

Cross-Reference to Related Application

This application is a Continuation-in-Part application of application Serial Number 732,444, filed May 9, 1985 and entitled "Method and Apparatus for Dehydrating High- Fructose Corn Syrup".

Field of the Invention

This invention relates to methods and devices for removing volatile components from less volatile components in a fluid. More particularly, it relates to methods and devices for drying or dehydrating products. Still more particularly, itrelatestomethodsanddevices fordehydrating temperature sensitive relatively non-volatile products such as food products, including corn syrups, high-fructose corn syrups, corn syrup blends, citrus and vegetable juices and extracts and concentrations thereof, proteins and the like, and for handling such products. It also relates to the dry products produced pursuant to the methods.

Background of the Invention

Techniques have been devised and equipment has been used to remove, in a liquid solution, the volatile components from a less volatile components. For example, processing. disposal or handling parameters may require that solvents (volatile components) be removed from those less volatile components in a chemical composition. Where the volatile component to be removed is water from the less volatile solid components, the process is referred to as drying or dehydrating. With specific reference to drying, it has been known to use spray drying where the water is flash evaporated or to use mechanical dryers such as evaporators. While these techniques are satisfactory in some applications, it is believed that for certain products or applications, these methods are not economical, result in degradation of the product or simply cannot be used. A specific group of products which has evaded efforts for economical dehydration are corn sweeteners, including high-fructose corn sweeteners (HFCS) , citrus and vegetable products and the like. With specific reference to corn sweeteners, a detailed background will now be provided.

Caloric sweeteners are typically either sucrose, derived from sugar cane and beets, or dextrose or fructose sweeteners derived from fruit and corn. When the starch present in corn is subjected to hydrolysis, dextrose and higher saccharides are produced. Such corn sweeteners are often refered to by their DE (dextrose equivalent) and usually fall in the range of between 36 DE and 95 DE corn syrups. If the dextrose and higher saccharides are subjected to isomerization via a process including certain enzymes, dextrose, fructose and higher saccharides are produced. A typical example after isomerization of the product may be represented by 42% fructose based upon dry solids content. This product can further be refined via chromatographic separation to yield a 90-95% or higher percentage fructose product. These high fructose corn syrups (HFCS) may be used as sweeteners or blended with corn sweeteners (dextrose sweeteners) for whatever purposes. With specific reference to HFCS, its use has grown, on a per capita basis, from 0.7 lbs. in 1970 to 29.8 lbs. in 1983. This rise in the use of HFCS is based to a great extent on the almost complete switch over to HFCS from sugar by the carbonated beverages industry. Since HFCS is sweeter, less is used and accordingly cost savings can be realized. However, the use of HFCS, it is believed, has peaked and leveled off recently indicating a mature market. It is further believed that if HFCS producers are going to obtain increased, new demand for their products, and compete with sugar, that HFCS be made available in a dry, amorphous, powder form.

As stated above, HFCS is derived from corn and is typically available between 42% and 90% fructose (dry weight basis) . The syrups can vary from 71% to 80% dry solids as an example. Sweetness of these HFCS products closely approximate that of sucrose. One processor has also produced crystalline fructose (100% fructose dry basis) from HFCS for specialty markets. However, due to the processing required, the crystalline fructose is many times more expensive that cane or beet sugar and hence has failed to overtake sugar in many ^•markets. It is believed that if a dry, flowable 42%, 55% and/or 90% HFCS corn syrup solids, orblendsthereofwithdextrosecornsyrup solids could be economically produced, that many markets heretofore occupied by sugar could be supplanted. For example, for baked foods such as cake mixes, dry powdered HFCS or blends thereof could provide sweeteness, and because HFCS is hygroscopic, would desirably retain moistness for the prepared cake. Of course, this is by way of example only, since a dry, flowable, amorphous (non-crystal) HFCS sweetener or blend could enter many other markets.

Attempts have been made to dry corn syrups and HFCS; however, to date, such attempts have failed or have for whatever reason, including economics, been discontinued. For example, Lundquist, Jr. et al. Patent No. 3,956,009, discloses a method for drying fructose solutions using a spray-drying technique in which solid crystalline fructose particles are interjected as seedstock into the product. HFCS is a particularly troublesome product since it is highly temperature sensitive in that subjection to high temperatures can degrade the fructose and caramelize the product and due to its hygroscopic nature it is difficult to handle.

Summary of the Invention

There is, therefore, provided according to the present invention methods and apparatus for removing volatiles from or dehydrating a feedstock which does not result in degradation of the product and for handling the resulting product. Also set forth are certain-products produced by the method.

Toward this end, the broad aspects of the present inventionincludethecreationofahot, acoustical environment and subjecting the feedstock to the environment for a period of time necessary for removal of volatiles or fordehydration. While the description hereinafter set forth refers to the methods, apparatus and products as being related to or the result of dehydration, i.e., removal of water, it is to be understood that the methods, apparatus and the products produced thereby may be directed toward or the result of removal of other volatiles such as solvents or the like. Theproduct tobedehydrated is introduced intotheenvironment as small droplets to maximize the surface area, the water moving to the surface of each particle and evaporating therefrom by virtue of the hot, acoustical environment. More specifically, the invention relates to a method for removing volatile components present in the liquid feedstock, the method including: providing a chamber having at one end an orifice and at the other end an outlet; particulating the liquid feedstock as droplets into the chamber; directing a high temperature gas through the orifice and chamber, the gas discharging at the outlet; generating acoustical waves in the chamber to agitate the droplets, said droplets moving co-directionally with the gas to the outlet, the high temperature gas and acoustical waves creating an environment to remove the volatile components from the droplets to reduce the droplets to less volatile components; and collecting the droplets of less volatile components at the outlet.

With specific reference to dehydrating high D.E. corn syrups, HFCS and blends thereof, the method includes: providing a chamber at one end an orifice and at the other end an outlet; particulating the corn syrup as droplets having a mean diameter of about 2-50 microns into the chamber; directing hot gas through the orifice into the chamber, the hot gas moving through the chamber to the outlet; generating acoustical waves in the chamber to agitate the droplets, said droplets moving co-directionally with the gas to the outlet, said hot gas and acoustical waves agitating the droplets for dehydration thereof; and collecting the droplets as an anhydrous melt at the outlet.

Continuing with specific reference to dehydration of corn sweeteners, the methods and devices for drying the corn sweeteners preferably includes a pulse combustor having an inlet directed to discharge through the orifice into the chamber and an outlet arranged to discharge into flow directing means. The pulse combustor exhausts cyclicly at both the inlet and outlet to produce high temperature gas on the order of 2000^βF and the following frequencies (octave bands) and sound pressures;

63 Hz - 103 decibels (db) 125 Hz - 144 db 500 Hz - 140 db 1000 Hz - 131 db 2000 Hz - 124 db

The combustor is contained within a closed housing and accordingly the exhaust gases from the discharge encounter the flow directing means and circulate through the housing to the orifice to pass therethrough with the discharge fromthe combustorinlet. Tocontrolthetemperature of the gases entering the chamber, primary tempering air is brought in at the housing to mix with the exhaust gases at the orifice to produce gas temperatures in the range of 300"F at the chamber adjacent the orifice. The corn syrup product is sprayed into the 300^βF, acoustical environment in droplets having a mean diameter of about 20 microns to thereby maximize the surface area for evaporation of moisture. The dispersed droplets move downwardly from the one end through the chamber due to gravity and the stream of pulsating exhaust gases from the combustor. When the droplets first encounter the high temperature, pulsating acoustical environment flash drying of at least the outer surface of the droplets occurs. The pulsating exhaust gases and acoustical waves agitate and scrub the droplets to enhance drying thereof. To prevent burning and discoloration of the corn syrup or insufficient drying of the droplets, the chamber is selected such that for a selected gas temperature, a suitable residence time, e.g., 0.4 - 10 seconds for the droplets is obtained. It is to be noted that to obtain the desired, anhydrous corn syrup solids without appreciable discoloration, degradation or burning, that the time-temperature relationship for the droplets is crucial. Too long of an exposure to the hot gases can cause discoloration, burning or degradation of the product while too little time results in insufficient drying.

According to one embodiment, the drying chamber may be open throughout its length. In another embodiment, a coalescer is positioned at the chamber outlet to collect the liquid anhydrous droplets and the product which has impinged upon and flows down the sides of the chamber to collect the anhydrous, corn syrup melt. In still another embodiment, multiple stage separation via a series of coalescers and demisters may be employed for complete removal of the liquid anhydrous products from the gases.

To control the temperature at the chamber outlet, secondary cooling air may be admitted to the chamber. The secondarycoolingairshouldbeselectedtoobtaintemperatures on the order of 200°F at which the anhydrous, corn syrup melt is still flowablewhilepreventingburning, discoloration or degradation of the product. In still a further embodiment, to prevent or reduce wall impingement of product which affects the residence time, various techniques can be employed including a wiper to clear the impinged product from the wall or a slotted membrane through which the secondary air can be brought in as an air curtain to direct the product downwardly to the coalescer while, if desired, favorably cooling the anhydrous melt to prevent degradation and discoloration. Still further, the wall temperature of the chambermaybecontrolledormultipledrippointsprovided.

As collected, the melt is cooled by suitable means to a temperature of about or below 60°C which hardens the melt and defines a dry solid corn syrup product. This product can be granulated either with or without the use of food grade processing aids to control the hygroscopicity and agglomeration of the granulated product. To further control the tendency of the products to agglomerate into an unmanageable mass, due to its hygrosσopicity, food grade, viscosity increasing processing aids such as gums, may be added to the feedstock to increase the sticky temperature of the product. According to an article authored by Galen Downton, Jose L. Flores Luna and C. Judson King and entitled "Mechanism of Stickiness in Hygroscopic, Amorphous Powders, Ind. Eng. Chem. Fundom. Vol. 21, No. 4, 1982, temperature, moisture and viscosity are interrelated for amorphous, hygroscopic powders and by increasing viscosity for a given percent moisture, a higher sticky temperature or temperature at which the granules stick together can be obtained. The processing aids to control hygroscopiσity may include tricalcium phosphate, dicalcium phosphate, dehydrated silicon dioxide, sodium aluminosilicate, calcium or magnesium stearate, maltodextrin or the like. Granulation preferably takes place in a dehumidified atmosphere or in the presence of inert gases such as nitrogen or carbon dioxide to prevent the dry solid corn syrup from acquiring moisture from the air. The product may be collected and stored in non-permeable bags or other containers to prevent the product from obtaining moisture from the environment. It has also been found that by blending sucrose (sugar) with the corn syrup feedstock that hygroscopicity canbe reduced if not controlled. The foregoing is significant since sucrose is largely an imported product and hence may be subject to higher costs and restrictions on imports. By blending sucrose with domestically derived fructose, a sweetener can be obtained which is less hygroscopic than pure corn syrup solids and the sweetener industry is not tied to imported sucrose.

In a further embodiment of the method and apparatus where the anhydrous product is presented as a dry solid and not a melt, the product can be separated from the air stream by various techniques including cyclone separators, bag filters or the like. For example, condensed milk has been dehydrated by the methods and apparatus according to the present invention, the condensed milk being presented as dry solids at about 200^βF at the chamber outlet. This product can be diverted to cyclone separators or bag houses for removal as desired. Other products which are believed to be when dried and at 200°F dry solids and hence would be susceptible to collection by cyclone separators or bag filters are lecithin, biosurfactants, orange juice, tomatoes, lemon concentrate, sweetened condensed milk, sweetened condensed milk with cocoa solids, condensed milk, condensed milk with cocoa solids, soy protein isolate, apple solids (puree) , egg whites, egg yolks, whole eggs, vegetable protein hydrolysate, whey protein concentrate, whole blood, soy polysaccharides, aluminum hydroxide and other products;

As can be appreciated, the method according to the present invention is capable of dehydrating or removing volatiles from temperature sensitive or hard to handle products. With specific reference to corn syrup, a dry, amorphous corn syrup product can expand the use of corn syrup into other heretofore unavailable markets increasing the use of corn syrups such as HFCS or other corn sweeteners. Accordingly, the dry corn syrup product can be made inexpensively thereby enhancing the entry of corn sweeteners into markets heretofore occupied by sugar or other caloric sweeteners. Further, by the equipment and methods set forth according to the present invention, it is believed that the process efficiently dries corn syrup and other products, such as orange juice, orange juice concentrate and lemon juice concentrate without deleteriously affecting flavors since dehydration takes place at relative low temperatures. Product degradation for other sensitive products is also avoided. Brief Description of the Drawings

These and other features and advantage of the present invention will become appreciated as the same becomes better understood with reference to the specification, claims and drawings wherein:

FIG. 1 is a schematic section view of an apparatus and method according to the present invention;

FIG.2 is a schematic illustration of another embodiment ofthe apparatus andmethodaccordingtothepresent invention; FIG. 3 is a schematic illustration of still another embodiment of the present invention;

FIG. 4 illustrates the derivation of dextrose and HFCS products from corn;

FIG.5 graphicallyillustratestheviscosity-temperature profile for HFCS products;

FIG. 6 illustrates a method according to the present invention for dehydrating and handling a corn sweetener product;

FIG. 7 illustrates a further embodiment for dehydration and collection of particularly corn sweetener products;

FIG. 8 illustrates still another embodiment of a method for dehydrating and handling a corn sweetener product;

FIG. 9A illustrates a pulse combustor adapted to generatetheenvironmentforremovingvolatiles ordehydration; and

FIG. 9B illustrates a spray nozzle adapted to spray the feedstock as small droplets. Detailed Description

The present invention is broadly directed to methods and apparatus for reducing liquids either by removing volatiles such as solvents from the less volatile components in a liquid chemical composition or for dehydrating a composition by removing water. The methods and apparatus operatebycreatingahightemperature, acoustical atmosphere, atomizing the composition in small droplets to increase the surface area into the atmosphere and to controlling the temperature-composition residence time relationship to provide for suitably reduction without degrading, burning or otherwise damaging the product. It is believed that the acoustically resonating atmosphere enables dehydration or concentration to take place at low temperatures and in an atmosphere which prevents degradation of a product. The invention also includes means for collecting and handling the reduced, e.g., dehydrated product.

The methods and apparatus according to the present invention as hereinafter described have successfully been utilized to dehydrate food products such as corn syrups including high fructose corn syrup (HFCS) , citrus juices, including lemon, concentrate orange juice, proteins, dairy products, egg products and others. This dehydration is accomplished without affecting flavor, burning the product or otherwise chemically degrading the product.

Corn Syrups

A feedstock which has been successfully processed according to the methods and apparatus of the present invention is corn syrup. Corn syrup as hereinafterunderstood means both regular, dextrose based corn syrups, high fructose corn syrups (HFCS) or various blends thereof. While the description hereinafter set forth is with reference to dehydration of corn syrups, it is to be understood that many products can be dehydrated or reduced according to the present invention.

Turning to FIG. 4, the derivation of corn syrups and high fructose corn syrup (HFCS) from corn as presently practiced in the industry is shown. The corn is processed at a wet mill by known means to separate the corn oil, protein and corn starch. The corn starch is therafter hydrolyzed producing dextrose, an aldose, plus higher saccharides. The extent of hydrolysis can yield low dextrose equivalent (DE) syrups or high DE (95-97 DE) syrups. The dextrose can thereafter be sent through an isomerizationcolumncontainingimmobilizedglucoseisomerize (an enzyme) . From the isomerization column, the output is approximately 42% fructose, 50% dextrose and 8% higher polysaccharides as measured on a dryweight basis. If desired to obtain higher fructose content, fructose and glucose must be separated by -a chromatographic separation column.

The separation column consists of an ion exchange resin causing the dextrose and fructose to vary in residence times. Depending upon which resin is used, either fructose or dextrose will emerge from the column first. A small fraction of the feedstock will emerge from the column as 90% fructose, 7% dextrose and 3% saccharides product as measured on a dry weight basis. It has been found that relative to sucrose, the 90% fructose (HFCS) can have a relative sweetness up to 1.8 times that of sugar. If practicable, the 90% fructose (HFCS) can be a desirable and usable end product in view of the fact that to obtain the desired sweetness, less product need be added. Accordingly, it may be desirable as an ultimate end product to dehydrate the 90% HFCS commercially for designated applications. If sweetness comparable to sucrose is desired, the 90% HFCS can be blended with 42% HFCS obtained pursuant to the isomerization step to obtain a 55% HFCS having a sweetness comparable to sugar. For applications such as table sweeteners, a dry, flowable 55% HFCS would be desirable. Further, since the 55% HFCS would be less expensive than 90% HFCS, economic considerations may point to a 55% HFCS as being a desired product if obtainable in a dry, pourable form. Typically, the 42% HFCS, 55% HFCS and 90% HFCS have a solids content of between 55%-80% the remainder to be represented by water. Accordingly, to produce a dry HFCS product, the water must be evaporated from the HFCS and preferably the evaporation would occur without significant discoloration, deterioration or caramelization of the product while maintaining the carbohydrate composition.

The dextrose corn syrup produced in a dehydrated state may also be usable as an ingredient. Further, the dextrose corn syrup and HFCS may be blended as desired and thereafter dehydrated to produce preferably a dry, flowable product.

With reference to corn syrups, the several properties thereof have, it is believed, contributed to the inability to produce these products in a dry, amorphous form. A first characteristic of most corn syrups is that at 200°F, the anhydrous (dehydrated) corn syrups take form as a viscous melt. This is particularly true of the HFCS corn syrups; however, for low percentage DE dextrose base corn syrups, they are solid when anhydrous at a 200^βF. With reference to HFCS specifically, FIG. 5 illustrates the relationship between temperature and viscosity. The graphic illustration presented in FIG. 5 is merely by a way of illustration and is not intended to present a quantitativerepresentationbetweentemperature andviscosity for high fructose corn syrups. Line C represents the relationship between temperature and viscosity for a 42% HFCS at about 0.5% moisture. As can be appreciated, the viscosity of this product above about 190^βF is rather low and hence as an anhydrous melt it flows rather freely. However, below about 190^βF, the viscosity radically increases rendering the product less flowable. Line A represents the relationship between temperature and viscosity for a 90% HFCS product at again about 0.5% moisture. Line B illustrates a 90% HFCS anhydrous product and about 2% moisture. As can be understood, this viscosity-temperature relationship for HFCS must be taken into account in any dehydration process and product handling.

Another characteristic of HFCS is that it is extremely temperature sensitive. At about 250^βF or above, the fructose tends to degrade into, for example, fructose dianhydrides. This fructose loss or degradation results in a discoloration of the product into a caramel light color and it results in loss of quality.

Still another consideration for dehydrated HFCS is that it is hygroscopic. Even should a technique be successfully used to dehydrate a high fructose corn syrup product, steps -must be taken during handling and storage to prevent moisture pickup.

Another consideration related to the hygroscopicity of HFCS and other corn syrups is the tendency of the particles of granulated HFCS to over time stick together to form an unmanageable mass. It is believed that the tendency of such particles to stick together is related to the viscosity at the surface of the particles which is, in turn, as stated above, related to temperature. If product viscosity at its surface can be increased then a higher temperature hereinafter referred to as the "sticky temperature", would be required to lower the viscosity to a point at which the particles would stick together. As for corn syrups, particularly HFCS, the foregoing characteristics of hygroscopicity, viscosity, temperature sensitivity and sticky temperature are related, and hence the dehydration of corn syrups have heretofore baffled those skilled in the art. With reference to the dehydration of corn syrups, the apparatus and methods according to the present invention will now be described.

Apparatus

Turning to FIG. 1, one embodiment of an apparatus according to the present invention adapted to function as a dehydrator 10 is shown. The dehydrator 10 has proven satisfactory in drying products such as corn syrups, including HFCS, concentrated milk, citrus juices, to name but a few. The dehydrator 10 includes a generally closed vessel 12 preferably defined by an upright cylinder having an inlet end 14 and a lower outlet end 16. As shown in FIG. 1, the outlet end 16 may be embodied as a closed base 17 having at a location thereof a discharge opening 18. Opposite the outlet end 16, the inlet end 14 may be conically tapered from an inlet opening defined by an orifice 20; While the orifice 20 may be a simple opening or the entire inlet end 14 may be open, it has been found that for purposes which will be hereinafter become evident, a somewhat tubular configuration for the orifice as illustrated in FIG. 1 is preferred. Between the orifice 20 and base 17, a dehydration chamber 22 is defined for the dehydrator 10.

To dehydrate the feedstock, such as corn syrup, means are provided for generating a hot, acoustical environment in the dehydration chamber 22. The environment heats and agitates the feedstock to liberate the moisture therefrom which is carried away from the product through the discharge opening 18. While these means may be embodied as means for supplying hot, desiccating gas to the dehydration chamber 22, and as a acoustic horn for generating the aforesaid acoustical waves, preferably as shown in FIG. 1, these means are embodied to include a pulse combustor 24 of the type described in Lockwood, U.S. Patent 3,462,955, the disclosure of which is hereby incorporated by reference. While the characteristics of the combustor 24 may vary, the following characteristics are given by way of example:

Capacity: 1,000,000 BTU/hr. Pulse Rate: 125 cycles per second

Temperature at combustor discharge withpropane as fuel: 1600"F - 2300^βF .

While described in the aforementioned patent, a brief discussion of the combustor 24 will be set forth herein with reference to FIG. 9. The combustor 24 is essentially comprised of an elongate hollow tube open at its ends and turned upon itself in generally a U-shaped configuration. The combustor 24 includes a combustion chamber 26 into which the fuel, such as propane is introduced via a conduit 28 as is combustion ignition air by a conduit 30. The fuel and compressed air mix within the combustion chamber 26 are then ignited with a sparking device shown as spark plug 32. Ignition of the fuel-air mixture within the combustion chamber 26 causes the pressure and temperature of the gases within the combustion chamber 26 to rapidly increase and expand for discharge through the open ends of the combustor 24 defined as the inlet 34 and discharge 36. As the gases expand, the pressure within the combustion chamber 26 drops such that ambient air is brought into the combustion chamber 26 from the inlet 34 for mixture with fuel. After the initial ignition, the high temperature gases remaining in the combustor 24 provide for self- co bustion and accordingly the spark plug 32 need not be operated. Eventually, equilibrium is reached with the combustor 24 operating in pulses of gas expulsion and expansion and intake of new combustion air and fuel. The frequency of the pulses is determined by the configuration of the combustor 24 but may be about 125 pulses (cycles) per second. Accordingly, the combustor 24 issues from both its inlet 34 and discharge 36 hot combustion exhaust gases at temperatures of between 1600^βF and 2300^βF and pulsating at or about 125 pulses per second.

Due to the nature of the combustor, sound waves are also issued from the combustor. The sound waves are generated pursuant to the rapid expansion of the products of combustion and the shock waves developed thereby. It has been found that the sound waves are generated in about six octave bands each having its sound pressures. These octave bands and corresponding sound pressures are set forth above under the heading "Summary of the Invention". As can be appreciated, the combustor 28 conveniently provides not only a high temperature gas but also an environment including pulses of hot gases and sound waves. To contain the combustor 24, dehydrator 10 includes a generally closed housing 38 disposed to upstand from the inlet end .14 of the vessel 12. The housing 38 may be connected at its lower extremity to the inlet end 14 and may include a medially disposed partition 40 for supporting the orifice 20. As can be seen from FIG. 1, the combustor 24 is suitably supported within the housing 38 such that the inlet 34 is directed downwardly to exhaust into the orifice 20. To direct the exhaust from the inlet 34 and the other gases as hereinafter set forth into the orifice 20, the orifice 20 may be provided with a conical collar 42 at its upper end. It has been found that to prevent unwanted turbulents and hot spots within dehydration chamber 24 that the orifice 20 and combustor inlet 34 should be arranged axially with respect to the vessel 12 and its dehydration chamber 22.

As stated above, pulsing, acoustic high temperature gases are emitted from both the inlet 34 and discharge 36 for the combustor 24. To fully utilize the production of these pulsating hot gases, the dehydrator 10 includes a flow directing trough 44 disposed on the partition 40 spaced from the discharge 36 and arranged to divert the pulsating hot gases in an upwardly direction into the housing 38 as indicated by arrows 46. These hot gases from the discharge 36 circulate through the housing 38 in a mixing chamber 48 defined by the generally closed housing 38 and above the partition 40. These pulsating hot gases are drawn by a venturi effect through the orifice 20 with those gases emitted from the inlet 34 for the combustor 24. To provide for temperature control for the gases received into the dehydration chamber 22, means are provided for admitting primary, tempering air into the housing 38 to mix with the high temperature gases and to provide air for combustion within the combustor 24. As shown in FIG. 1, these means include a primary air duct 50 which directs ambient, heated or chilled air into the mixing chamber 48. To control the flow through the primary airdμct 50, a suitable control such as a butterfly valve 52 may be provided. Depending upon the product to be concentrated or dehydrated, the flow through the primary air duct 50 is controlled to achieve a desired temperature at zone A defined at the upper reaches of the combustion chamber 26 and at the outlet of the orifice 20. The primary air could be filtered and preheated as desired. For dehydrating corn syrups such as HFCS, it is believed that a desired temperature at zone A is about 300^βF. Again, however, this temperature can be adjusted by increasing or decreasing the volume of primary air admitted through the primary air duct 50. The air is mixed with the combustion gas exhausted from the discharge 36 and is further mixed with the discharge from the inlet 34 at the mixing orifice 20.

While the combustor 24 may be arranged as indicated to direct the inlet 34 into the orifice 20,^' it is to be understood that the combustor could be arranged to instead direct the discharge 36 into the orifice or to direct both the inlet and discharge into the orifice. It is believed that greater mass flow is achieved from the inlet 34 of combustor 24 and hence the arrangement as indicated in FIG. 1 may be preferred.

To deliver the corn syrup feedstock to the dehydrator 10, and more particularly the dehydration chamber 22, means are provided for dispersing (particulating) the syrup feed as preferably a fine aerosol spray into the chamber at the inlet end 14 and in a direction which is co-current or co-directional with the direction of the gases received into the dehydration chamber 22 through the orifice 20. While co-directional spraying may be preferred, countercurrent spraying can also be employed. With countercurrent spray, the sprayed product quickly reversed direction to flow co-directionally with the gas. With reference to FIGS. 1 and 9, the delivering means includes at least one spray nozzle 54 which receives the feedstock corn syrup'under pressure as from a pump or the like. The nozzle 54 is adapted to disperse the liquid corn syrup into droplets having a mean diameter of about 20 microns. It has been found that nozzles of the type manufactured by Sonic Development Corporation, Mahawh, New Jersey, and available to handle a variety of flow rates disperses corn syrup such as HFCS into droplets the diameter of which falls in the range of 2-50 microns. The partiσulation of the feedstock into small droplets maximizes the surface area available for removal of moisture and dehydration of the product. With regard to the nozzle, it has been found that sonic atomizing spray nozzles are well adapted for this purpose in that they can produce the desired fine mist from viscous corn syrups and are not sensitive to flow rate variations which occur in the feed rate.

In operation, the nozzle 54 is suppliedwith an atomizing gas which may be steam or air, however, dry air is preferred in that does not add moisture to the process. The atomizing air is supplied to the nozzle from a suitable source such as a compressor through a conduit 56 attached to the spray nozzle by a coupling 58. The nozzle 54 has an axial passageway 60 communicating at one end with the conduit 56_. and at the other end reducing down to define a smaller diameter axial bore 62. By virtue of the small diameter bore 62, a restriction is provided which accelerates the atomizing air flow to a desired outlet velocity. Spaced from the bore 62 by supports 64 is a cup-shaped resonator 66. The high velocity atomizing air issued from the bore 62 impinges against the resonator 66 to generate standing shock waves upstream of the resonator 66 which are adapted to break up, atomize and disperse the syrup feed into the desired droplet size.

Feedstock, e.g., corn syrup, is fed through a conduit 67 to an annular duct 69 arranged about the passageway 60 and generally closed at both ends. Openings 71 deliver the feedstock from duct 69 to the axial bore 62 where it is carried by the atomizing air to the standing shock waves for atomization thereof. The nozzle 54 is arranged downstream of the combustor 24 and orifice 20 as shown in FIG. 1. The nozzle 54 may be surroundedby thermo-insulatingmaterial or may be determined that the flow rate of the corn syrup and atomizing air is sufficient enough to cool the nozzle during operation thereof. During start-up, water may be passed through the nozzle for cooling.

The feedstock is accordingly via the nozzle 54 sprayed into the dehydration chamber 22 as a fine mist. A pattern of spray typically produced by the nozzle 54 is as a cone, the apex of which is at the nozzle 54. To provide an even spray, it is preferred that the nozzle 54 be arranged axially within the vessel 12 and coaxially with the orifice 20 and combustor inlet 24.

The corn syrup feedstock sprayed from the nozzle 24 initially flash dries under the influence of the high temperature gas and acoustical atmosphere within the dehydration chamber 24. Due to evaporative cooling, the temperature at zones B and C where the feedstock spray encounters the hot resonating - atmosphere, may be about 250^βF or less. Moisture under the driving force of the high temperature gas and acoustic agitation migrates to the surface of each droplet and quickly evaporates therefrom as the droplet falls by the force of gravity and of the impetus of the gases issuing from the orifice 20 toward the vessel end 60. At the outlet end 16, the dehydrated product is collected and processed as described below. The gases having removed the moisture from the product exit from the dehydration chamber 22 at the discharge opening 18 and are disposed of in an efficient manner which may include removing the latent heat from the gases for further use in the process.

If desired, a blower (not shown) can be provided to forceably draw the gases from the dehydration chamber 22 through the outlet opening 18. The vessel 12 is sized to provide a sufficient residence time for the droplet given the temperature of gases in the dehydration.

As stated above, certain corn syrups such as HFCS when anhydrous or substantially anhydrous, e.g. 1% moisture, and at 200°F are characterized as a dry melt. Therefore, the dehydrated droplets of product approaching the outlet 16 are liquid and flowable. To provide a means for collecting these droplets, the dehydrator 10 may include a coalescer 68. The coalescer 68 includes a multiplicity of impingement points forthe droplets, the droplets impinging and coalescing on the surfaces into one or a plurality of melt streams which are combined and the dehydrated product is ultimately recovered at product outlet 73. The gases from the coalescer 68 enter the base 17 and pass to the outlet opening 18. As stated above with certain products notably high fructose corn syrups orhigh D.E. corn syrups, thetemperature must be maintained sufficiently high to keep the product flowable for collection and removal from the coalescer 68. In addition to the consideration of viscosity, many products such as HFCS are temperature sensitive and if overexposed to the high temperature may tend to degrade and damage the product.

To further control the temperature of the dehydrated melt, various secondary control means may be employed. As shown in FIG. 1, one method may be to provide secondary air through a secondary air duct 70 arranged proximate the coalescer 68, flow through the secondary air duct 70 being controlled by a valve 72. The secondary air supplied through duct 70 may be scavenged from the gases emitted from the discharge opening, may be ambient air or may be filtered and preheated ambient air. With a suitable blower (not shown) , the secondary air is provided through the duct 70 into the dehydration chamber 22 proximate the coalescer 68 to control the temperature of the anhydrous melt collected thereat. For HFCS, it is preferred that the temperature be controlled at the coalescer to about 200^βF ± 20^βF. At 200^βF, the dehydrated HFCS collected at the coalescer is flowable providing for the collection at and removable from the coalescer 68. Furthermore, at these temperatures, and the time of exposure during collection and removal from the coalescer 68, the corn syrup composition is maintained and the product is not degraded or otherwise seriously affected. During dehydration of corn syrups such as HFCS, it has been found that some of the droplets impinge upon the wall of the vessel residing there, or moving downwardly toward the bottom end 16. In certain circumstances, impingement does not present a problem; however, for certain corn syrups, such as HFCS, impingement may result in overexposure of the product to the high temperature atmosphere within the dehydration chamber 22 causing discoloration and degradation of the product. Unlike the free falling droplets which rapidly exit the chamber 22, those droplets which impinge upon the wall of the vessel 12 require additional time to run down the wall to the coalescer 68 or product outlet 73 for removal from the dehydrator 10. The mechanism for wall impingement is not clearly understood; however, it is believed that the larger sized droplets having increased momentum due to their mass may be those that impinge the wall of the vessel 12 while the smaller droplets free fall to the discharge end 16. Another mechanism operating apart from or in cooperation with droplet size is turbulence of the desiccating gas set up within the vessel 12. This turburlence may tend to create eddies urging the product to impinge the wall. Whatever the mechanism for certain products which are particularlytemperature sensitivewall impingement can affect product quality and yield. To control wall impingement, the dehydrator 10 may be provided with a wiper mechanism (not shown) which continually wipes the inside surface of the vessel to urge the wall impinging product downwardly to the coalescer 68 for collection thereof. Hence, these mechanical means acting like a wiped film evaporator can be utilized to quickly remove the sensitive product impinging on the wall to prevent degradation thereof. Another solution may be to provide temperature control for the wall of the vessel 12 to control the temperature of the product impinging thereon, and prevent degradation thereof. Also multiple drip points may be provided such that the products flowing down thewall encounters the drippoints and falls to the coalescer.

Still another approach to reduce or minimize wall impingement is as illustrated in FIG. 1, including means for developing an air curtain 75 down the wall of the vessel 12. According to this embodiment, the dehydrator 10 includes a cylindrical membrane 74 coaxially disposed within the dehydration chamber 22, the membrane 74 including a plurality of perforations or apertures 76. For food grade products, the membrane 74 would preferably be constructed from stainless steel to facilitate cleaning anddisinfection. The apertures 76 may be provided in selective patterns over the membrane 74 or may be continuous. Cooperating with the membrane 74 to develop the air curtain, the dehydrator 10 includes a tertiary air duct 78 the flow of air through which is controlled by a valve 80. The source of air through the tertiary air duct 78 may be from a blower and the air passage through the duct may be preheated and/or filtered similarly to that described above with reference to the secondary air duct 70. The membrane 74 has a smaller diameter than that of the vessel 12 and accordingly an annulus 77 is defined between the membrane 74 and vessel 12 along the length of the membrane. The tertiary air supplied through the duct 78 enters the annulus 77 and flows into the dehydration chamber 22 through the apertures 76. Upon entering the dehydration chamber 22, the tertiary air is urged by the exhaust gases from the combustor 24 to turn downwardly toward the outlet end 16. To enhance the turning of the tertiary air downwardly, the apertures 76 may be contoured to deflect the tertiary air in the aforesaid downwardly direction to define the air curtain along the inside surface of the membrane 74. To enhance the even generation of the air curtain along the length of the membrane 76, the tertiary air duct 78 may be arranged tangentially with respect to the vessel 12 whereupon the tertiary air enters and swirls downwardly within the annulus 77 feeding the apertures 76 which, in turn, define the air curtain. With the air curtain thusly created along the inside surface of the membrane, droplets which would normally have a tendency to impinge upon the wall of the vessel 12, are instead turned downwardly carried by the air curtain toward the coalescer 68. Hence, impingement is prevented or reduced. Advantageously, the air supplied through the tertiary air duct 78 and aperture 76 can be employed to control product temperature in lieu of supplying air through the secondary air duct 70. By controlling the supply of air to the tertiary air duct 78 with valve 80, temperature of the product at the coalescer 68 can be controlled to prevent degradation of the product collected thereat.

It is to be understood that the membrane and/or coalescer 68 may not be required depending upon the characteristics of the feedstock. The embodiment of the dehydrator 10 for dehydrating and handling products which are solid when anhydrous at a temperature or temperatures within the dehydrator need not include the coalescer membrane. For example, the dehydrator and handling equipment illustrated in FIG. 2 would be suitable for dehydrating products such as condensed milk, tomatoes, orange juice concentrate, lemon concentrate and apple puree to name a few. According to FIG. 2, the dehydrator 10 includes^* the vessel 12 having an outlet end 16 and inlet end 14. The housing 38 contains the combustor 24, the inlet 34 which discharges through an orifice 20 mixing with the primary mixing air brought in through primary air duct 50 into the housing producing temperatures at the outlet of the orifice 20 in the range of 300^βF. The combustor 24 also generates acoustical waves within the dehydration chamber 22 defined by the vessel 12. The product, for example condensed milk, is pumped to the nozzle 54 where it is atomized in the manner described above. By virtue of the hot, acoustical atmosphere and the residence time necessary for the droplets to fall through the vessel 12 to the outlet end 16, the droplets are dehydrated defining at the outlet end 16 powdered, dehydrated condensed milk. The dehydrated powdered condensed milk is swept from the vessel 12 through the discharge opening 18 into a discharge duct 82 and to, for example, one or more cyclone separators 84. The cyclone separator 84 efficiency is related to the velocity of the gas and particles passing through and accordingly, if desired, to provide for a force draft through the cyclone separator 84, a force draft fan 86 may be provided. The dehydrated powdered condensed milk is separate from the desiccating gas at the cyclone 84, the powdered milk falling to a port 88 for removal from the cyclone 84. To increase the efficiency of the overall dehydration process, the discharge from the fan 86 may be used to preheat the primary air or for other purposes.

In lieu of using the cyclone 84, the discharge 82 may be connected to a bag filter 90 containing filtering surfaces 92 which trap the powdered condensed milk but pass the gases. Again, if desired, a fan 86 may be employed to create a forced draft through the bag filter 90. At intervals, the materials are shaken from the filtering services 92 to be collected at a port 88'.

With reference to FIG. 3, still another embodiment of a dehydrator 10 is shown. This embodiment is particularly adapted for dehydrating products which, at temperatures of about 200^βF appear as an anhydrous melt. As shown, the dehydrator 10 includes the vessel 12, having an inlet end 14 and defining a dehydration chamber 22 as set forth above. A closed combustion chamber 26 houses the combustor 24, the inlet 34 of which discharges through an orifice 20 into the dehydration chamber 22. To control the temperature of the gases admitted into the dehydration chamber 22, the primary duct 50 is provided to supply cooling and mixing air to the housing 38. If desired, a cylindrical wall 94 may define an annular space 96 within the housing 38, the tempering air flowing into the space 96 and over the wall 94 for mixing with the high temperature gases emitted from the discharge 36 for the combustor 24.

As described, the dehydrator 10 may include the membrane 74 and either or both of the secondary or tertiary air ducts 70 and 78 for admitting cooling air and/or air for forming the air curtain.

To collect the anhydrous, melt product, the coalescer 68 is disposed at and defines the bottom of the dehydration chamber 22. The product and gases pass through the coalescer 68 which coalesces the anhydrous melt product into larger streams whereupon it drops into a Y-shaped collection channel 98 and is removed from an opening 100. The gases are directed by the channel 98 to a second coalescer 102 which removes further anhydrous, melt product which may be airborne in the gas stream. The cross sectional areas of the coalescer 68 and second coalescer 102 are sized to provide gas velocities for efficient separation of product. The product removed at the second coalescer 102 falls downwardly into the channel 98 for collection from the opening 100. The gases from the channel 98 enter an exhaust duct 104 and are directed through a demister 106 disposed therein. At the demister 106, any remaining product in the gas stream is removed. From the demister 106, the gases having a temperature of about 190°F may be directed through a heat exchanger 108 adapted for heating one or more of the primary air, secondary and/or tertiary air. To control velocities through the coalescer 68, second coalescer 102 and demister 106, a force draft fan 110 may be adapted to draw the gas through the exhaust duct 104. The discharge of the fan 110 may be returned to the dehydrator 10 in the form of primary, secondary or tertiary air. It is believed that the efficiency of product removal according to the embodiment of FIG. 3 is enhanced by the addition of a second coalescer and demister. With reference to FIG. 6, an overall embodiment of the apparatus and methods for dehydration and granulation of the product, such as high fructose corn syrup or other corn syrup is illustrated. As shown, the process in FIG. 6, includes a dehydration portion, shown generally as 112, a post-treatment portion shown generally as 114, and a pretreatment portion shown as 116. The pretreatment portion 116 may or may not be provided depending upon the state, i.e., pressure, temperature, presence of solids and flow rate of the feedstock which may be 42% - 90% fructose,

36 - 97 D.E. corn syrup and/or blends thereof, or for that matter, any other suitable product. The supply from, for example, a processing plant is shown as syrup supply 118.

The pretreatment portion 116 may, as alluded to above, not be required if supply 118 is at a desired state. In its most rudimentary embodiment, the pretreatment portion 116 may include a tank 120a adapted to receive the syrup supply 118 and hold an amount of syrup in readiness for dehydration. Tank 120a may be sized to provide a surgecapacitysothatdehydrationcantakeplaceuninterrupted at a rate which may be different from the rate of supply 118. Tank 120a may also provide a convenient point at which processing aids, if desired, may be incorporated into the syrup to condition the dehydration and subsequent handling. Means for agitating the syrups such as an agitator 122a are provided on tank 120a to ensure uniform product feed composition.

Depending upon the percent solids and temperature of the syrup, the viscosity thereof may be such that pumping of the syrup is difficult. To reduce viscosity, for the syrup, it may be advantageous to heat the product prior to delivery to the dehydration portion 112. Heating may also be desired for the syrup feed regardless of solids content to enhance spray atomization for dehydration. For heating the syrup feed, tank 120b is provided to receive the syrup supply 118. Tank 120b has a steam jacket 124 for heating the feed to a temperature to suitably reduce the viscosity for pumping and to enhance spray ato ization. A temperature of 98"F may be appropriate. An agitator 122b may be provided to ensure uniform product feed and for blending of process aids as is needed.

The syrup retained in either or both of the tanks 120a, 120b is supplied to the dehydration portion 112 by a pump 126. The pump is selected to provide the syrup to the dehydration portion 112 at the desired pressure and flow rate as determined by the components of the dehydration portion 112.

The dehydration portion 112 includes the apparatus set forth above for dehydrating a syrup feed which may have a solids content of, for example, 71%. To dry the syrup feed, the dehydration portion 112 includes the dehydrator 10 described above with reference to FIG. 1, including the vessel 12, inlet and outlet ends 14 and 16, and the other components set forth above. The dehydrated product which appears as an anhydrous melt is collected at the coalescer 68 wherefrom it drops through the product outlet 73 into a collection vat 128. The vat 128 may include a jacket 130 for hot fluid to maintain the anhydrous product as a liquid. The hot gases discharge from the dehydrator 10 may be disposed of as by ducting them to the atmosphere or may be further utilized for heating primary, secondary or tertiary air. From the vat 128, the anhydrous melt is transferred by a pump 132 or by gravity to the post-treatment portion 114. To prevent the melt from hardening in the transfer line, the line may be insulated or jacketed.

The post-treatment portion 114 of the process is adapted to cool, solidify, granulate and protect the near anhydrous melt from moisture pickup. According to one embodiment, the post-treatment portion 114 includes a rotary former 134 which may be interσooled with water or the like. The liquid melt is fed to the former 134 which forms the melt into buttons, ingots, sheets or strips or pastilles 136 and then dispenses the melt on to a traveling belt 138. The belt 138, which may be of the type used in the candy industry, is stainless steel and is driven to transport the sheets, strips or pastilles deposited thereon for further processing. After the melt has been deposited on the belt 138, it may or may not be heated by a heater 140 to remove any less vestiges of the water from the melt. Quite often, the dehydrator 10, reduces the moisture to the area of about 1% and hence further moisture removal is not required. On the belt, the melt is cooled as by circulating water in contact with the underside of the belt 138. The partially cooled melt is further cooled by secondary cooling means which may consist of circulating a chilled brine in contact with the belt 138 cooling the anhydrous melt to a temperature of approximately 16^βC whereupon the melt becomes an amorphous solid. The speed of the belt 138 is selected such that suitable heat transfer can be obtained to harden the melt. At the end of the belt, the hardened melt is scraped from the belt with a doctor blade 142 and is collected in a bin 144 for packaging or for subsequent granulation. Alternatively or additionally,, the melt from the vat 128 may be sent to a casting head 146 which casts the melt in long strips onto a belt 138' similar to that described above. Along the belt, the strips cool into rods 148 which are broken off fromthe belt 138^» for further processing as required.

To granulate the anhydrous, solid corn syrup, it is fed to a grinder 150. To purge any moisture from the grinder 150 prior to introduction of the solid, anhydrous product, the grinding space may be flushed with a dry inert gas such as nitrogen, carbon dioxide or the like. Upon introduction of the product into the grinder, which may be an auger-type grinder, dry inert gas continually flushes the grinding chamber for cooling and for maintaining the inert atmosphere. If desired, liquid nitrogen or the like may be admitted contemporaneously with the anhydrous, solid product for grinding to remove heat and maintain the inert atmosphere. It has been found that the heat of grinding and friction if not removed will cause the solid products to liquify and plug the grinder. The ground product may be thereafter sent through a sieve to remove the fines which are believed to contribute to lumping and agglomeration of the ground product. Sieving should also take place in an inert atmosphere to prevent moisture pickup of the product.

As stated above, dehydrated corn syrups are extremely hygroscopic and hence care must be taken in packaging and handling of the material to prevent moisture pickup. If desired, food grade processing aids may be added during or after grinding to the product to limit or prevent moisture pickup. Suggested processing aids would be tricalcium phosphate, dicalcium phosphate, silicon dioxide, sodium aluminosilicate, calcium or magnesium stearate, maltodextrin or the like. Of course, it is to be understood that other processing aids could also be added to the product to limit or reduce moisture pickup. With reference to FIGS. 7 and 8, further embodiments of the apparatus and methods according to the present invention are shown. According to FIG. 7, the collected anhydrous melt product from the dehydrator 10 is deposited directly upon the belt 84' whereupon it is cooled and removed for subsequent granulation. According to the embodiment of FIG. 8, the anhydrous melt collected in the vat 128 may be sent to a vacuum evaporator 152 to remove any further moisture and, from the vacuum evaporator deposited on either belt 138' where it is cooled or to the drop former 134 which deposits the anhydrous melt onto belt 138 for cooling andremoval inthemannerdescribedabove.

While the foregoing description has been set forth with regard to a particular embodiment of the dehydrator

10, it is to be understood that it can be modified without departing from the spirit and scope of the invention. For example, the outlet end 16 for the dehydrator 10 may be entirely open, the material collected at the coalescer coalescing and dropping in a random fashion into the collection vat 128 or directly onto a cooling media such as the belt as described above.

Method

Generally speaking, with reference to the apparatus discussed above, the method according to the present invention is directed to a process for removing volatile components from less volatile components present in a liquid feedstock. The method includes- providing the chamber 22 which has at one end the orifice 20 and at the other end a discharge 18. The liquid feedstock is atomized or sprayed into the chamber 22 as small droplets and a high temperature gas is directed through the orifice 20 into the chamber 22, passes through the chamber 22 and is removed therefrom at an outlet. In conjunction with a high temperature gas, acoustical waves are generated in the chamber 22 to agitate the droplets, the droplets moving codirectionally with the gas to the outlet 18. The hightemperaturegasandacousticalwaves createanenvironment to remove the volatile components from the droplets to reduce the droplets to less volatile components. Finally, the process includes collecting the less volatile components so reduced.

With the broad concepts of the method according to the present invention set forth above, more specific details would be hereinafter set forth with reference to particular products which have been dried pursuant to the method and with the apparatus set forth below.

HFCS HFCS has been dehydrated with a 1,000,000 BTU/hr combustor operating at about 45 percent capacity and using a dehydration vessel 12 having a 3 foot diameter and an axial length of about 8 feet from the bottom of the orifice 20 to the coalescer 68. The size of the orifice was 7-3/8 inches in diameter with an axial length of 10 inches.

Tempering air was admitted through the primary duct 50 to achieve a temperature at Zone A of about 400^βF. Spraying the HFCS into the chamber at about one pound per minute and into droplets, the mean diameter of which is about 20 microns, the following temperature profile at the various zones within the dehydration chamber have been obtained.

PERCENT TEMPERATURE TEMPERATURE TEMPERATURE MOISTUREIN % SOLIDS/ ZONE C ZONE D DISCHARGE 18 DEHYDRATED PRODUCT ADDITIVES "F "F "F - 20 PRODUCT

90 HFCS¹ 50 260 - 280 220 - 230 210 0.5 90 HFCS¹ 70 260 - 280 220 - 230 210 1.3

^•'^•coalescer collection.

Thelength, diameterandgasthroughputofthedehydration chamber 22 defines a residence time which under these conditions should be about 6 seconds or less. At a one- pound-per-minute feed, the product removed at the product outlet 73 after analysis was found to contain 0.5% moisture and hence was almost entirely dehydrated. After drying, the product was cooled to solidify and was thereafter ground and sieved and, if desired, mixed with food grade processing aids to control the hygroscopicity. 1 The same process was followed for dehydration of HFCS and dextrose corn syrup blends and for 62 - 95 D.E. dextrose base corn syrups themselves.

5 Corn Syrups/Sucrose Blends

As stated above, it has been found that mixing sucrose with HFCS and perhaps other corn syrups or blends thereof, controls or at least reduces the hygroscopicity of the dehydrated product. Accordingly, blends of 42 HFCS and

10 10%, 15%, 20%, 25% and 50% sucrose have been dehydrated according to the methods and apparatus of the present invention. It is believed that to date no others have produced amorphous blends of corn syrups and sucrose as sweeteners. According to test results, the following

15 conditions in the dehydrator identified above were found.

. PERCENT TEMPERATURE TEMPERATURE TEMPERATURE MOISTUREIN % SOLIDS/ ZONE C ZONE D DISCHARGE 18 DEHYDRATED PRODUCT ADDITIVES "F "F "F - 20 PRODUCT

__ 42 HFCS¹ 10% sucrose 260 - 280 220 - 230 210 1.8 ²⁰ 42 HFCS¹ 15% sucrose 260 - 280 220 - 230 210 0.5

42 HFCS¹ 20% sucrose 260 - 280 220 - 230 210 1.3

42 HFCS¹ 25% sucrose 260 - 280 220 - 230 210 0.6

42 HFCS¹ 50% sucrose 260 - 280 220 - 230 210 1.0

^■^-coalescer collection.

25 It has been found that dilution of the product with water to reduce the percent solids enhances drying in many instances. This observation was particularly striking since the addition of water to a product to be dehydrated would appear to be inconsistent. While the mechanism for

30 enhancing dehydration to lower percentages of moisture is not completely understood, it is believed that diluting the feedstock may reduce viscosity and enhance particulation and thereby promote dehydration.

35 Other Products

Other products which have been dried in the 1,000,000 BTU/hr. combustor test unit are set forth below in the Table along with pertinent temperatures, percent solids and the percent moisture found to exist in the dehydrated product. It is to be understood that these products are set forth by way of example only since as discussed above, the dehydrator 10 according to the present invention could be used to dry many other products.

PERCENT

TEMPERATURE TEMPERATURE TEMPERATURE MOISTUREIN

% SOLIDS/ ZONE C ZONE D DISCHARGE 18 DEHYDRATED

PRODUCT Al .DITIVES "F ^•F ^•F ^•* 20 PRODUCT

80 HFCS¹ 50 260 - 280 220 - 230 210 1.2

55 HFCS¹ 50 260 - 280 220 - 230 210 0.7

55 HFCS¹ 70 260 - 280 220 - 230 210 1.5

42 HFCS¹ 50^' 260 - 280 220 - 230 210 0.5

42 HFCS¹ 70 260 - 280 220 - 230 210 1.5

63/43 D.E.² 50 200 180 165 3.0

42/43 D.E.² 50 200 180 165 5.0

36/43 D.E.² 50 200 180 165 5.0

Protein Hydrolysate² 51 240 210 200 3.5

Sweet & Cond. Milk² 60 175 160 145 5.0

Sweet & Cond. Milk² 50 175 160 145 5.0

Condensed Milk² 50 175 160 145 5.0

Sweet Condensed Milk w/Cocoa Liquor² 50 175 160 145 5.0

Condensed Milk w/

Cocoa Liquor² 50 175 160 145 5.0

Tomato² 20 165 160 145 6.5

Tomato² 14 165 160 145 6.5

Orange Concentrate² 65 175 180 165 3.0

Orange Concentrate² 50 165 170 160 5.0

Lemon Concentrate² 50 200 210 190 3.0

Apple Puree² 25 225 200 190 5.0

^•'^•coalescer collection.

² eye lone or baghouse collection.

Of particular interest is the ability of the apparatus and methods according to the present invention to dehydrate vegetable and fruit extracts such as orange juice and lemon juice concentrates to name but a few. Due to the low temperature dehydration obtained within the chamber and believed to be attributable to the environment created, the dehydrated product was not degraded and did not loose flavor.

Other Considerations

While stated above and illustrated in the drawings, co-directional introduction of the itemized feedstock into the dehydrator 10, i.e., in the same direction of the gases entering from the orifice 20, has proven to provide satisfactory results. It is to be understood however that orienting the nozzle to spray in other directions may also prove successful. For example, co-directional spraying, due to the turbulence and eddies set up within the dehydration chamber 22, may result in product being carried back and collecting and clogging the nozzle 54. Countercurrent spraying may avoid this problem.

Due to the time-temperature conditions within the combustor, the production of carbon monoxides and nitrogen oxides is minimized.

Residence time from 5 to 7 seconds at 200°F appears to provide sufficient drying of the HFCS products to moisture levels at or below 1%. As far as HFCS is concerned, experience has shown that a final moisture of less than 1% is preferred if not required.

While we have shown and described certain embodiments ofthe apparatus, methods andproducts, includingadehydrated, amorphous corn syrup product, blends and a corn syrup/sucrose blend, it is to be understood that the invention is subject to many modifications without departing from the spirit and scope of the claims set forth herein. For example, multiple spray nozzles may be required for higher product throughput and various other configurations of product collection and processing can be used.

Claims

WHAT IS CLAIMED IS:

1. A method for removing volatile components from less volatile components present in a liquid feedstock comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; particulating ^• the liquid feestock as droplets into the chamber (22) ; directing a high temperature gas through the orifice (20) into the chamber (22) through the chamber (22) and out the outlet (18) ; generating acoustical waves in the chamber (22) to agitatethedroplets, saiddropletsmovingco-directionally with said gas to the outlet (18) , said high temperature gas and acoustical waves creating an environment to remove the volatile components from the dro -_plets to reduce the droplets to less volatile components; and collecting the less volatile components.

2. The method of claim 1 wherein the particulating step includes spraying the feedstock as droplets into the chamber (22) .

3. The method of claim 2 wherein the spraying step includes spraying the feedstock as droplets in a co-current direction with the high temperature gas.

4. The method of claim 1 wherein the particulating step includes spraying the feedstock into the chamber (22) as droplets the mean diameter of which is 20 microns.

5. The method of claim 1 wherein the chamber (22) is cylindrical having an axially arranged orifice (20) , said directing step including directing the high temperature gas through the orifice (20) axially into the chamber (22).

6. The method of claim 1 wherein the directing step includes directing a gas at a temperature of about 300"F through said orifice (20) .

7. The method of claim 1 wherein the acoustical wave generating step includes operating a horn to generate said acoustical waves.

8. The method of claim 7 wherein the generating step includes operating the horn to generate acoustical waves at a frequency of between 125-10,000 Hz between 100- 200 decibels.

9. The method of claim 1 wherein the gas directing and acoustical wave generating steps includes operating a pulse combustor (24) to direct its high temperature pulsating exhaust gases through said orifice (20) .

10. The method of claim 9 further including augmenting the combustor high temperature exhaust gases with primary mixing air, the exhaust gases and primary air mixing at said orifice (20) .

11. The method of claim 10 wherein the method further includes controlling the flow primary mixing air to obtain a temperature of about 300"F through said orifice (20) .

12. The method of claim 1 wherein the less volatile components are liquid droplets, the collecting step including separating the reduced droplets from the gases passing from the chamber (22) .

13. The method of claim 12 wherein the collecting step includes providing a droplet impingement surface (68) in the path of the gases passing through the chamber (22) .

14. The method of claim 1 wherein the less volatile components aresolid, thecollecting step includingseparating (84, 90) the solid components from the gases passing through the chamber (22) .

15. The method of claim 1 further including providing auxiliary^' air to the chamber (22) to cool the reduced feedstock and prevent degradation thereof.

16. A method for dehydrating a liquid feedstock comprising: providing a dehydrator (10) having a vessel (12) having at one end (14) an orifice (20) and at an opposite end (16) a discharge (18) , the vessel (12) defining a dehydration chamber (22) ; directing high temperature desiccating gas through the orifice (20) , the gases passing through the chamber (22) and exiting at said opposite end (16) ; generating acoustical waves in the chamber (22) ; particulating the feedstock as small droplets into the chamber (22) , the high temperature gas and acoustical waves creating an environment to agitate and dehydrate the droplets in the chamber (22) ; and collecting the dehydrated product from the environment.

17. The method of claim 16 wherein the steps of directing high temperature gas and generating acoustical waves includes operating a pulse combustion device (24) and directing its high temperature gas exhaust and pulsed acoustical waves through the orifice (20) into the chamber (22).

18. Themethodofclaim17 furtherincludingcontrolling the temperature of the exhaust gases admitted into the chamber (22) .

19. The method of claim 18 wherein the controlling step includes mixing cooler air with said gases.

20. The method of claim 19 wherein the mixing step includes mixing the cooling air at the orifice (20) .

21. The method of claim 17 further including enclosing the combustion device (24) in a housing (38) and arranging the combustor (24) to exhaust from its inlet end (34) into the orifice (20) and to exhaust from its discharge end (36) into the housing to be drawn through the orifice (20) with the exhaust from the inlet end (34) .

22. Themethodofclaim21 furtherincludingcontrolling the temperature of the gases admitted into the chamber (22) by mixing cooler air in the housing (38) with the exhaust gases from the combustor discharge (36) , the mixture drawn through the orifice (20) with the exhaust gases from the combustor inlet (34) .

23. Themethodofclaim18 furtherincludingcontrolling the temperature within the chamber (22) at a location (68) where theproduct is collectedtopreventproductdegradation.

24. A method for dehydrating a corn syrup product comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; directing a high temperature gas through the orifice (20) into the chamber (22) , the gas passing through the chamber (22) and exiting at the outlet (18) ; generating acoustical waves in the chamber (22) ; the high temperature gas and acoustical waves defining a dehydrating environment in the chamber (22) ; sprayingthecornsyrupintochamber (22) downstream of the orifice (20) and into the dehydrating environment, said droplets dehydrating in said environment; and removing the dehydrated corn syrup from the environment.

25. Themethodofclaim24 furtherincludingcontrolling the temperature of the environment.

26. The method of claim 24 wherein the steps of directing a high temperature gas and generating acoustical waves includes operating a pulse combustion device (24) and directing its high temperature, acoustical exhaust gases through the orifice (20) into the chamber (22) .

27. Themethodofclaim26 furtherincludingcontrolling the temperature of gases entering the chamber (22) to about 300°F (149^βC) .

28. The method of claim 27 further including removing the corn syrup from the environment after an exposure of between 3 and 10 seconds.

29. Themethodofclaim27 furtherincludingcontrolling the temperature of the environment at the outlet (18) to about 200^βF (93^βC) .

30. A dehydrated corn syrup product produced according to the method of claim 24.

31. The method of claim 24 wherein the corn syrup is a blend of dextrose based and fructose based corn syrups.

32. The dehydrated product producted by the method of claim 31.

33. The method of claim 24 wherein the corn syrup is high fructose corn syrup.

34. The dehydrated high fructose corn syrup produced by the method of claim 33.

35. The method of claim 24 further including the step of pretreating the corn syrup product prior to spraying.

36. The method of claim 35 wherein the pretreating step includes preheating the corn syrup product.

37. The method of- claim 35 wherein the pretreating step includes blending with the corn syrup a food grade processing aid to increase the viscosity of the dehydrated product.

38. A dehydrated product produced according to method of claim 37.

39. The method of claim 35 wherein the pretreating step includes blending sucrose with the corn syrup product.

40. A product produced according to the method of claim 39.

41. A method for dehydrating a high fructose corn syrup product comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; directing a high temperature gas through the orifice (20) into the chamber (22) , the gas passing through the chamber (22) and exiting the chamber (22) at the outlet (18) ; generating acoustical waves in the chamber (22) , the high temperature gas and acoustical waves defining a dehydrating environment in the chamber (22) ; spraying the high fructose corn syrup into the chamber (22) downstream of the orifice (20) and into the dehydrating environment, said droplets dehydrating in the environment; and removingthedehydratedproduct fromtheenvironment.

42. The method of claim 41 wherein the steps of directing high temperature gases and generating acoustical waves includes operating a pulse combustor (24) and directing its high temperature acoustically resonating exhaust gases through the orifice (20) into the chamber (22) .

43. Themethodofclaim42 furtherincludingcontrolling the temperature of the environment.

44. The method of claim 43 including controlling the temperature of the gases entering the chamber (22) at the orifice (20) .

45. The method of claim 44 including controlling the temperature of the gases entering the chamber (22) at the orifice (20) to about 300°F (149^βC).

46. The method of claim 45 including supplying (70) secondary cooling at the location where the product is removed to prevent product degradation.

47. The method of claim 46 wherein the secondary cooling maintains the dehydrated product temperature at about 200^βF (93^βC) .

48. The method of claim 45 including providing the chamber (22) such that the sprayed product remains in the environment for between 3-10 seconds.

49. A dehydrated high fructose corn syrup product produced according to the method of claim 41.

50. A method for dehydrating and handling a corn syrup product comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; directing a high temperature gas through the orifice (20) into the chamber (22) , the gas passing through the chamber (22) and exiting at the outlet (18) ; generating acoustical waves in the chamber (22) ; the high temperature gas and acoustical waves defining a dehydrating environment in the chamber (22) ; sprayingthecornsyrup intochamber (22) downstream of the orifice (20) and into the dehydrating environment, said droplets dehydrating in said environment; and removing the dehydrated corn syrup from the environment; cooling the dehydrated product into a solid state; and granulating the solid, dehydrated product in a dehumidified atmosphere.

51. The method of claim 50 further including cooling of the product during the granulation step.

52. The method of claim 50 further including mixing food grade processing aids with the corn syrup prior to spraying.

53. The method of claim 51 wherein the cooling steps include providing a chilled inert gas atmosphere during grinding.

54. The method of claim 50 further including adding food grade processing aids to the product to control hygroscopicity.

55. A dehydrated, product produced according to the method of claim 50.

56. A dehydrated, granulated product including food grade processing aids according to claim 54.

57. A method for dehydrating fluids extracted from fruits and vegetables comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; directing a high temperature gas through the orifice (20) into the chamber (22) , the gas passing through the chamber (22) and exiting at the outlet (18) ; generating acoustical waves in the chamber (22) ; the high temperature gas and acoustical waves defining a dehydrating environment in the chamber (22) ; spraying the fluid into chamber (22) downstream of the orifice (20) and into the dehydrating environment, said droplets dehydrating in said environment; and removing the dehydrated fluid fromthe environment.

58. Themethodofclaim57 further includingcontrolling the temperature of the environment.

59. Themethod of claim24whereinthe steps ofdirecting a high temperature gas and generating acoustical waves includes operating a pulse combustion device (24) and directing its high temperature, acoustically resonating exhaust gases through the orifice (20) into the chamber (22) .

60. Themethodofclaim26 furtherincludingcontrolling the temperature of gases entering the chamber (22) to about 300^βF (149°C) .

61. The method of claim 27 further including removing the corn syrup from the environment after an exposure of between 3 and 10 seconds.

62. The methodof claim27 further including controlling the temperature of the environment at the outlet (18) to about 200^βF (93^βC) .

63. A dehydrated extract produced according to claim 57.

64. A method of dehydrating and collecting a product which when dehydrated and at about 200°F (93^βC) is solid, the method comprising: providing a chamber (22) having at one end (14) an orifice (20) and at the other end an outlet (18) ; directing a high temperature gas through the orifice (20) into the chamber (22) , the gas passing through the chamber (22) and exiting at the outlet (18) ; generating acoustical waves in the chamber (22) , the high temperature gas and acoustical waves defining a dehydrating environment in the chamber (22) ; spraying the product as small droplets into the chamber (22) and dehydrating environment, said droplets dehydrating to a solid particles carried by said gas; and separating the particles from the gas.

65. Themethodofclaim64 furtherincludingcontrolling the temperature of the environment.

66. The method of claim 64 wherein the separating step includes separating the particles from the gas with at least one cyclone separator (84) .

67. A dehydrator (10) comprising: an upright vessel (12) having an inlet end (14) and anoutlet end (16) , saidvessel (12) defining a dehydration chamber (22) ; an orifice (20) at said inlet end (14) ; a discharge opening (18) at said outlet end (16) ; means forgenerating anddirectinghightemperature gases through the orifice (20) , said gases passing through the chamber (22) and exiting from the discharge opening

(18); means for generating acoustical waves in said chamber (22) , said high temperature gases and acoustical waves defining a dehydrating environment in the chamber (22) ; means (54) for spraying a liquid product to be dehydrated into the chamber (22) downstream of the orifice

(20) as droplets, said droplets encountering the dehydrating environment and dehydrating; and means for separating the dehydrated product from the environment.

68. The dehydrator of claim 67 wherein the high temperature gas and acoustical wave generating means is a pulse combustor (24) having an inlet (34) and a discharge (36) , said high temperature gases and acoustical waves issuing from both of said inlet (34) and discharge (36) .

69. The dehydrator of claim 68 wherein the combustor (24) is arranged to direct its inlet exhaust through said orifice (20) .

70. The dehydrator of claim 69 further including means (50) for controlling the temperature of the gases entering the chamber (22) .

71. The dehydrator of claim 70 further including a housing (38) to enclose the combustor (24), the exhaust gases from the combustor discharge (36) circulating within the housing (38) , the temperature control means including means (50) for providing cool tempering air into the housing (38) to mix with the discharge (36) exhaust, said mixture drawn through the orifice (20) with the exhaust from the combustor inlet (34) .

72. The dehydrator of claim 70 wherein the controlling means are adapted to control the temperature of the gases entering the chamber (22) to about 300^βF (149°C).

73. The dehydrator of claim 69 wherein the chamber (22) is cylindrical, said combustor (24) arranged such that the inlet (34) is coaxial with said chamber (22) .

74. The dehydrator of. claim 73 wherein the orifice (20) is embodied as a cylindrical tube and is arranged coaxial with said chamber (22) .

75. The dehydrator of claim 67 further including means for controlling impingement of the product with the wall of the chamber (22) .

76. The dehydrator of claim 75 wherein the impingement controlling means includes means (74) for defining an air curtain (75) along the wall of the chamber (22) to direct the product downwardly.

77. The dehydrator of claim 76 wherein the wall curtain defining means includes a perforated membrane (74) disposed in the chamber (22) and means (78) for supplying air to the membrane (74) , the air passing through the perforations (76) to define said air curtain (75) .

78. The dehydrator of claim 77 wherein theperforations (76) are configured to direct the air downwardly.

79. The dehydrator of claim 75 wherein the impingement controlling means includes wall wiping means.

80. The dehydrator of claim 67 wherein the spraying means (54) is adapted to produce droplets having a mean diameter of about 20 microns.

81. The dehydrator of claim 67 wherein the chamber (22) has a height to provide a droplet residence time in the environment of about 3-8 seconds.

82. The dehydrator of claim 67 wherein the separating means includes a coalescer (68) disposed at the bottom of the chamber (22) .

83. The dehydrator of claim 67 wherein the separation means includes a cyclone separator (84) .

84. The dehydrator of claim 67 wherein the separation means includes filter means (92) .

85. A dehydrator and product handling assembly comprising: an upright vessel (12) having an inlet end (14) and anoutlet end (16) , saidvessel (12) defining a dehydration chamber (22) ; an orifice (20) at said inlet end (14) ; a discharge opening (18) at said outlet end (16) ; means forgenerating anddirectinghightemperature gases through the orifice (20) , said gases passing through the chamber (22) and exiting from the discharge opening (18) ; means for generating acoustical waves in said chamber (22) , said high temperature gases and acoustical waves defining a dehydrating environment in the chamber (22) ; means (54) for spraying a liquid product to be dehydrated into the chamber (22) downstream of the orifice (20) as droplets, said droplets encountering the dehydrating environment and dehydrating; and means for separating the dehydrated product from the environment; means for solidifying the separated dehydrated product; and means for granulating said product.

86. The assembly of claim 85 wherein the dehydrated product is hygroscopic, said granulating means including dehumidifying means.

87. The dehydratorofclaim86whereinthedehumidifying means includes an inert gas environment.

88. The dehydrator of claim 86 further including means for removing the heat generated during granulation.