Mass storage and dispensing system for liquids such as citrus products

A system in which mass quantities of liquids may be stored in a substantially frozen state, portions thawed for dispensing, and any undispensed thawed portions rechilled for further storage is disclosed. The system includes a tank with a substantially bell-shaped, or flared, interior, the flaring of the tank surface combining with force of gravity to detach frozen material for dispensing. Separate temperature control sections allow selected areas of the tank to be heated or cooled as necessary, moreover, and distinct reservoirs of heat-transfer liquid (such as glycol) may be used for heating versus cooling the tank.

FIELD OF THE INVENTION 
This invention relates to equipment for storing and dispensing substantial 
masses (quantities) of liquids and more particularly to systems for 
storing and, as appropriate, indirectly cooling and heating such liquids, 
which may (but need not) be citrus juices. 
BACKGROUND OF THE INVENTION 
In an existing system used to store and dispense "not-from-concentrate" 
citrus juices, juice initially is pumped from a processing facility into 
holding tanks where it may be tested and, if desired, blended with other 
juices. If a tanker truck is available to transport the juice from the 
processing facility to its next destination, the juice may be transferred 
promptly from the holding tanks to the truck for travel. If, however, a 
truck is not immediately available, the juice typically is drawn from the 
holding tanks into fifty-five gallon drums and stored temporarily in 
freezers. 
Once the juice has been frozen in drums, it must thereafter be prepared for 
transport when a truck becomes available. In such cases the drums are 
brought through a steam tunnel, which defrosts the juice, and then 
emptied. The slushy juice is then passed through equipment which 
mechanically chops the ice crystals formed therein into finer particles so 
that the juice can be returned to the holding tanks. From the holding 
tanks, the juice can be pumped into the waiting tanker truck for transport 
as described in the preceding paragraph. 
Although this system is suitable for storing and dispensing masses of 
liquids, it is, in some respects, both expensive and cumbersome to 
operate. Purchasing and maintaining thousands of drums require substantial 
expenditures, and the drums themselves, although reusable, often must be 
replaced either annually or biannually. Transferring juice from holding 
tanks to drums and back to holding tanks further complicates the storage 
process, introducing additional activities into the process that ideally 
need not occur. Significant energy is expended, moreover, in both 
defrosting the juice and mechanically chopping its crystals into finer 
particles. 
U.S. Pat. No. 5,000,008 to Heath ("the Heath patent"), incorporated herein 
in its entirety by this reference, describes another storage system for 
fruit juices. As disclosed in the Heath patent, the system includes a tank 
for storing liquid (i.e. juice) on which an ice cap floats. Liquid is 
pumped from the bottom of the tank through a pipe assembly to the top of 
the tank, whereupon it "is directed into the upper opening . . . of a 
substantially vertically oriented communicating tube . . . located within 
the storage tank." See col. 6, lines 26-29. It then flows through the 
communicating tube to the bottom of the tank, effectively being 
recirculated within the tank without contacting the ice cap. According to 
the Heath patent, the communicating tube thereby provides a vent 
"functioning as a means of relieving pressure at critical times such as 
when ice is being formed." See id., lines 39-41. 
To thaw the ice cap and empty the tank, the Heath patent discloses raising 
the temperature of a glycol tracer line forming part of the storage system 
and using a fan to blow warm air against the sides of the tank. Doing so 
warms both the liquid circulating through the pipe assembly and the ice 
cap, purportedly "releasing the attached ice cap . . . from the side 
walls" of the tank. See col. 7, lines 25-27. Alternatively, "coils which 
are installed in the side walls" of the tank "are used to supply heat." 
See id., lines 43-45. 
Because primarily directed to avoiding rupture of the storage tank when ice 
forms in liquids, the Heath patent neither discloses nor contemplates 
"releasing" the ice cap in other ways. The tank illustrated therein is 
thus in most respects conventional, having a single wall and formed 
generally in the shape of a cylinder. The system utilizes an agitator to 
maintain substantially uniform liquid temperature within the tank, 
moreover, and employs glycol tracer lines solely to thaw liquid and 
prevent it from freezing in the pipe assembly. Furthermore, no mechanism 
for refreezing the liquid after it is thawed is disclosed in the Heath 
patent, as thawing is described only in conjunction with emptying (the 
entirety of) the tank. 
SUMMARY OF THE INVENTION 
The present invention, by contrast, comprises a system in which mass 
quantities of liquids may be stored in a substantially frozen state, 
portions thawed for dispensing, and any undispensed thawed portions 
rechilled for further storage. Including an unconventional tank with a 
substantially bell-shaped interior, the invention combines the flaring of 
the tank surface with force of gravity to detach frozen material for 
dispensing. Separate temperature control sections allow selected areas of 
the tank to be heated or cooled as necessary, moreover, reducing energy 
waste that otherwise would occur were such controls not present. In some 
embodiments distinct reservoirs of glycol (or other heat-transfer 
material) are used for heating and cooling the tank, and the tank itself 
may be double-walled. 
The invention thus avoids entirely the need for freezing liquid in 
fifty-five gallon drums when tanker trucks are unavailable to convey it to 
another destination. Similarly, by maintaining the particular quantity of 
juice in a single storage tank, the invention omits the steam tunnels and 
mechanical chopping equipment previously used to warm frozen liquid for 
removal from the drums. The double walls of the tank additionally insulate 
the inner shell from the ambient environment, preventing it from 
interfering with the glycol-based heating and cooling processes. 
In one embodiment of the invention, the system includes a holding tank, a 
liquid chiller, and the substantially bell-shaped storage tank. Juice or 
similar liquid from the processing facility may, if desired, be routed 
initially to the holding tank (as in the existing system) for testing and 
blending with other juices. The so-tested or -mixed juice then travels to 
the liquid chiller, where it changes into a frozen, slushy state at a 
temperature of approximately 23.degree.-26.degree. F. An exemplary 
indirect liquid chiller is the model VS-400 Freezer made by Cherry-Burrell 
Corporation, in which ammonia circulates within tubing inside the freezer 
to absorb heat from the juice. The slushy material may then be pumped to 
the storage tank until ready to be dispensed. 
Additionally included in this embodiment are dual glycol reservoirs, a 
glycol chiller, and a heat exchanger functioning as a glycol heater. 
Although those skilled in the art will recognize that a single glycol 
reservoir could be used instead, in many circumstances greater 
heat-transfer efficiency may be achieved by not having both to heat and to 
cool the same volume of glycol. Thus, at least this one embodiment of the 
invention contemplates employing the dual reservoirs, one connected to a 
chiller and the other to a heating mechanism. After heating or cooling, as 
the situation warrants, the glycol too may be pumped to the storage tank. 
Unlike the juice, however, which resides within the inner shell of the 
storage tank, any glycol pumped to the tank is normally confined between 
the inner and outer shells. As a consequence, no heating or cooling liquid 
is intended ever to contact the juice itself. Food-grade glycol 
nonetheless is a suitable choice for such liquid because not deemed 
harmful to humans should it inadvertently contact the juice and ultimately 
be consumed. 
To assist the dispensing process, at least the inner shell of the storage 
tank may be flared from top to bottom. As noted earlier, configuring the 
shell in this manner facilitates detaching frozen material from the sides 
of its interior. When the shell is heated and juice is dispensed from the 
bottom of the tank, frozen juice above the bottom begins to melt and slide 
under force of gravity along the surface of the shell. Because that 
surface continually flares, however, the melting juice will at some point 
fall from the wall surface rather than remaining adhered to it. 
Embodiments of the present invention use baffles to achieve separate 
temperature control of various sections of the inner shell. Angle irons 
(or similar material) welded or otherwise attached to the outer surface of 
the inner shell channel the glycol flowing thereagainst and isolate 
sections of the shell from other sections. In one embodiment, for example, 
the inner shell is divided into sections approximately three feet high. If 
the volume of juice within the inner shell does not extend more than three 
feet above the bottom, glycol need only be supplied to the lowermost three 
foot section of the tank. Alternatively or additionally, the area between 
the inner and outer shells may be divided radially. 
Finally, the invention also encompasses use of multiple storage tanks of 
the type described above in a single facility. Such a tank "farm" may be 
necessary when volumes of liquid substantially greater than the volume of 
a single tank have been processed for storage. To the extent the multiple 
tanks are present in the same general location, the building or other 
structure within which they are housed may be divided into sections and 
separately cooled. 
It is thus an object of the present invention to provide a system for 
storing quantities of liquids in a substantially frozen state. 
It is also an object of the present invention to provide a system for 
storing liquids that avoids use of multiple drums, steam tunnels, and 
mechanical chopping and agitating equipment. 
It is another object of the present invention to provide a system for 
storing liquids in which a tank (or shell of a tank) has a flared interior 
surface to facilitate detaching frozen liquid from the surface. 
It is a further object of the present invention to provide a system for 
storing liquids in which separate temperature control sections allow 
selected areas of the tank to be heated or cooled as appropriate. 
It is yet another object of the present invention to provide a system for 
storing liquids in which distinct reservoirs of heat-transfer liquid are 
used for heating and cooling the tank. 
It is additionally an object of the present invention to provide a system 
for storing liquids employing a double-walled tank, with the heat-transfer 
liquid confined to the space between the outer surface of the inner shell 
and the inner surface of the outer shell. 
Other objects, features, and advantages of the present invention will 
become apparent with reference to the remainder of the text and the 
drawings of this application.

DETAILED DESCRIPTION 
FIG. 1 schematically illustrates system 10 of the present invention. As 
shown in the embodiment of FIG. 1, system 10 includes holding tank 14, 
liquid chiller 18, and storage tank 22. Also comprising system 10 of this 
embodiment are dual (glycol) reservoirs 26 and 30, (glycol) chiller 34, 
and heat exchanger 38. Juice (or other liquid) J exiting a processing 
facility enters piping 42 for transport to holding tank 14, where it may 
be mixed or blended with other juices or liquids if necessary or desired. 
In one embodiment of the invention, holding tank 14 is a three hundred 
fifty gallon structure of stainless steel. While in holding tank 14, 
characteristics (e.g. composition, quality) of juice J may also be tested 
if appropriate to do so. 
Although juice J from holding tank 14 may be transferred directly to a 
tanker truck or other object in some circumstances, FIG. 1 illustrates 
such juice J exiting to liquid chiller 18 via piping 42. As noted above, 
liquid chiller 18 may be a model VS-400 Freezer made by Cherry-Burrell 
Corporation, in which liquid ammonia A circulates within tubing inside the 
liquid chiller 18 to absorb heat from juice J. Those skilled in the art 
will recognize that the model VS-400 Freezer exemplifies the equipment 
suitable for absorbing heat from juice J and that other mechanisms for so 
absorbing heat may be used instead. 
Juice J, by then comprising a slushy material at a temperature of 
approximately 23.degree.-26.degree. F., is conveyed through piping 42 to 
storage tank 22. Unlike some existing systems, embodiments of system 10 
consistent with FIG. 1 contemplate retaining juice J in storage tank 22 
until dispensed to a tanker truck. Thus, storage tank 22 obviates the need 
for the fifty-five gallon drums, steam tunnels, and mechanical chopping 
equipment previously employed. For improved performance of system 10, the 
air surrounding storage tank 22 preferably should be maintained at a 
temperature between 18.degree.-20.degree. F. 
Once resident in storage tank 22, juice J must be thawed for dispensing. 
Accordingly, system 10 contemplates pumping glycol from reservoir 30 to 
heat exchanger 38 to warm it to a temperature of approximately 
175.degree.-200.degree. F. Heat exchanger 38 may be a conventional device 
that uses steam (or any other suitable medium) for heating. After exiting 
heat exchanger 38, the glycol or other heat-transfer fluid is transferred, 
again via piping 42, to storage tank 22 to warm juice J indirectly. 
Following dispensing of juice J, any remaining juice within storage tank 22 
may be rechilled for further storage. Such rechilling is accomplished by 
passing glycol from reservoir 26 through chiller 34 to cool it to a 
temperature of approximately zero to -5.degree. F. and then pumping the 
cooled glycol to storage tank 22. The glycol indirectly absorbs heat from 
the remaining juice, typically returning the temperature of the juice to 
between 23.degree.-26.degree. F. Nitrogen may also be injected into or 
otherwise supplied to storage tank 22 to inhibit formation of bacteria 
therein. 
Glycol chiller 34 is shown in FIG. 1 as being separate from liquid chiller 
18. Dividing the cooling functions in this manner obviously decreases the 
possibility of any glycol mixing with juice J in system 10. Chillers 34 
and 18 need not be separate devices, however, and instead may be parts of 
the same equipment, particularly if the identical cooling mechanism (e.g. 
ammonia A) is employed. FIG. 1 additionally illustrates various of the 
many pumps 46 and valves 50 that those skilled in the art will recognize 
may be used in connection with system 10 to transfer materials to desired 
locations. 
Storage tank 22 (FIGS. 2-8) includes inlet 54, outlet 58, and walls 62 and 
66. Together with top 70 and bottom 74 of storage tank 22, wall 62 forms 
inner shell 78. When pumped to storage tank 22, juice J enters inlet 54 at 
the top 70 of the tank 22 and is distributed, under force of gravity, to 
the bottom 74 of inner shell 78. Additional quantities of juice J entering 
tank 22 likewise fall toward bottom 74, increasingly filling tank 22 until 
a selected mass of the juice J is stored. 
In at least one embodiment of tank 22, wall 66 and top 70 are formed of ten 
gauge stainless steel, with wall 66 being approximately twenty feet (20 
ft.) high. Walls 62 and 66 consistent with the present invention 
additionally may be generally cylindrical in shape. At least wall 62, 
however, flares between top 70 and bottom 74, thus having a greater 
diameter adjacent bottom 74 than near top 70. Such flaring need not be 
extensive: certain embodiments of tank 22, for example, include a wall 62 
whose diameter adjacent top 70 is twenty feet (20 ft.) and whose diameter 
adjacent bottom 74 is twenty feet, two inches (20 ft., 2 in.). Greater or 
lesser flaring of wall 62 may, of course, be useful in different 
circumstances. Wall 66 similarly may be flared if desired, although doing 
so is not necessary in the context of the present invention. 
Flaring wall 62 results in a configuration of inner shell 78 that 
facilitates detaching frozen juice J from the wall 62. In general, 
substantially frozen liquid tends to adhere to the side walls of 
cylindrical and other storage tanks, making detachment of the liquid for 
dispensing difficult. The Heath patent appears to recognize this problem, 
describing use of various heating mechanisms to "release" an attached "ice 
cap." In my experience merely heating a tank is often inadequate to detach 
substantially all of the liquid from the side walls, however, and thus 
additional means--such as flaring wall 62--are required. Hence, when inner 
shell 78 is heated and juice J is dispensed from outlet 58, frozen juice J 
above bottom 74 begins to melt and slides under force of gravity along the 
surface of continually-flaring wall 62, at some point falling from wall 62 
rather than remaining adhered to it. 
Between walls 62 and 66 are baffles 82. Angle irons or similar objects may 
be used as baffles 82, operating to channel flow of liquid glycol or other 
thermal transfer material to wall 62. Baffles 82, if metal, may be welded 
to the exterior of wall 62, although those skilled in the art will 
recognize that other means of attaching baffles 82 to either or both of 
walls 62 and 66 may be employed. 
FIGS. 3-4 illustrate alternate methods of employing baffles 82. In FIG. 3, 
for example, baffles 82 channel glycol G in paths (shown by arrows) 
through relatively small vertical sections 84 of storage tank 22. 
Horizontal plates 86 divide the area between walls 62 and 66 into these 
sections 84, which in certain embodiments consistent with FIG. 3 are 
approximately three feet high. Because each section 84 may be valved 
independently of other sections 84, glycol G may be permitted to pass 
through some sections 84 while not through others at any particular time. 
Independent temperature control of each such section 84 may thus be 
obtained simply by appropriately setting the valve (or other mechanism) 
that allows flow of glycol G into the section 84 of interest. This 
independence is especially useful when juice J does not fill tank 22. For 
example, if juice J is not present in the uppermost portion of tank 22, 
glycol G need not be circulated through sections 84A of FIG. 3 to cool or 
heat the juice J. Vertically-oriented plates 90 may be used if desired to 
subdivide further the area between walls 62 and 66 for even greater 
temperature control of juice J. In the alternate paths of FIG. 4, baffles 
82 channel glycol G essentially vertically through the area of tank 22 
between walls 62 and 66 to achieve this purpose. 
FIGS. 5-8 detail baffles 94 present between bottom 74 and base 98 of tank 
22. Together with plates 102, baffles 94 channel glycol G as shown in the 
paths printed in FIGS. 5-6, with plates 102 dividing the area between 
bottom 74 and base 98 into quadrants to enhance temperature control of 
juice J. FIG. 6 illustrates one such quadrant, or zone 106, in which 
glycol G enters through inlet 110, circulates through the zone 106, and 
exits via outlet 114 to piping 42. Providing such zoned temperature 
control is useful both in dispensing and storing juice J, and it 
eliminates the need for an agitator such as that included in the system of 
the Heath patent. FIG. 8 additionally illustrates the sloping nature of 
bottom 74 facilitating flow of juice J to outlet 58. 
The foregoing is provided for purposes of illustrating, explaining, and 
describing embodiments of the present invention. Modifications and 
adaptations to these embodiments will be apparent to those of skill in the 
art and may be made without departing from the scope or spirit of the 
invention. For example, although various dimensions, shapes, and other 
characteristics of tank 22 and its components have been illustrated or 
described, the invention is, of course, not necessarily limited to tanks 
having identical characteristics, but may include other tanks or analogous 
equipment designed to accomplish results similar to those of the present 
invention.