COPYRIGHT RIGHTS IN THE DRAWING
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The applicant has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
1. Technical Field
This invention relates to heat transfer apparatus, especially as may be employed for concentrating and drying operations. Such apparatus is particularly well suited to sanitary applications, such as processing and packaging of foods.
2. Background
Methods and apparatus for the transfer of heat through a thin, infrared transparent film between a flowable product such as sludge, slurry, extract, juice, or other like product, and a heated or chilled liquid, have been taught in previous patents used in earlier development of our equipment, namely U.S. Pat. No. 4,631,837, issued Dec. 30, 1986 for a Method and Apparatus for Drying Fruit Pulp and the Like, and U.S. Pat. No. 6,047,484, issued Apr. 11, 2000, for a Method and Apparatus for Evaporating Liquid from a Product, and the disclosures of each of these U.S. patents is incorporated herein in their entirety by this reference. However, the challenge of providing a clean, sanitary environment for evaporation of liquid from a product, or for chilling a product, especially as practiced using a thin flexible film material, has continued to require development of new apparatus and methods, especially to take advantage of such apparatus when applied to food preparation. And concurrently, the need for sanitary systems that can be easily cleaned to a high level of purity, i.e., freedom from biological contamination, has continued to be of utmost importance to food processors. Thus, the ability to provide an improved, easily cleanable and easily maintainable evaporation or chilling apparatus for sanitary, cleanable applications, such as drying of fruits or other foods, has become increasingly important. This is especially true at locations which are making foods such as fruit leathers from a pulp or fruit juice mass, which, after drying, must remain viable for long storage periods. Also, in order to pass governmental inspections in most, if not all locales, easily cleaned sanitary equipment is mandatory. Thus, there has been an increasing demand for high performance drying and evaporation systems, including for designs such as those taught in the prior art patents that were just noted above, but that demand has been coupled with a further requirement to provide an easily replaceable heat transfer element useful when drying a food product. Consequently, this disclosure provides description of a novel heat transfer apparatus, and of the novel equipment in which such heat transfer apparatus can be employed.
BRIEF DESCRIPTION OF THE DRAWING
In order to enable the reader to attain a more complete appreciation of the invention, and of the novel features and the advantages thereof, attention is directed to the following detailed description when considered in connection with the accompanying figures of the drawing, wherein:
FIG. 1 side cross-sectional view of one embodiment of the replaceable heat transfer apparatus taught herein, showing in the sectioned illustrations the inlet flood box, the pair of flexible planar polyester sheets, an outlet manifold, as well as the adjustably inclined support tray, and a retractable hood, and a working product being distributed to the upper flexible planar sheet and flowing down to a working product collection pan.
FIG. 2 provides a perspective photograph of one embodiment for an inlet floodbox (at the top) and an outlet manifold (at the bottom), showing the vacuum outlet on the upper edge of the outlet manifold, as well as a pair of sanitary quick disconnect type outlets for discharging a heat transfer fluid from the outlet manifold.
FIG. 3 provides a photograph of an inlet floodbox.
FIG. 4 provides a perspective view of one embodiment for an inlet floodbox (at the top) and an outlet manifold (at the bottom), showing the vacuum outlet on the upper edge of the outlet manifold, as well as a pair of sanitary quick disconnect type inlets in the inlet floodbox, as well as a pair of sanitary quick disconnect type outlets for discharging a heat transfer fluid from the outlet manifold.
FIG. 5 provides a perspective view of one embodiment for an inlet floodbox (at the top) and an outlet manifold (at the bottom), showing the liquid distribution passageways in the inlet floodbox, and the liquid collection passageways in the outlet manifold, as well as mounting locations for bolts which are used to affix, via suitable clamps, upper and lower flexible planar sheets to the apparatus, as further described herein.
FIG. 6 is a perspective view of one embodiment of an inlet floodbox, showing the upper mounting clamp used to secure the upper flexible planar sheet to the inlet floodbox, as well as some of the fasteners (here, bolts) used to space the upper flexible planar sheet outward from the liquid distribution passageways.
FIG. 7 shows a heat transfer apparatus as taught herein, with the support structure, adjustably inclinable support tray, a replaceable heat transfer module in operable location on the support tray, and the retractable air hood in an up, normally non-operating position wherein it is distanced away from the replaceable heat transfer module.
FIG. 8 is a view similar to the view first shown in FIG. 7, but now showing additional details of the orientation of the retractable hood, and a safety latch used to secure the retractable hood in an open condition without dependence on an telescoping cylinder; also shown is an air actuated cylinder, such as a Bimba® brand (or equivalent) which can be utilized to increase or decrease the angle at which the support tray is inclined.
FIG. 9 is a photograph of the lower end portion of the replaceable heat transfer module, showing the use of a tail collection sheet, where the tail collection sheet extends past the outlet manifold for a preselected distance in order to carry the working product to a working product collection pan; also visible in this view are the upwardly and outwardly sloping sidewall portions of the support tray, which cradle the evaporator envelope marginal portions to provide a flat bottomed V-shape area to contain the working product during evaporation.
FIG. 10 is a close up photograph of a small part of the lower end portion of the replaceable heat transfer module first shown in FIG. 9, now showing in additional detail the use of a tail collection sheet, where the tail collection sheet extends past the outlet manifold for a preselected distance in order to carry the working product to a working product collection pan.
FIG. 11 is a close up photograph of a portion of the inlet floodbox, showing the use of a lower inlet clamp to secure the lower flexible planar sheet to the inlet floodbox.
In FIG. 12, both the lower flexible planar sheet and the upper flexible planar sheet are shown affixed in a fluidly sealed condition to the inlet floodbox; also seen at a first end of the inlet floodbox is a marginal area of the evaporator envelope which extends transversely beyond the first end of the inlet floodbox.
FIG. 13 illustrates the flexible nature of the upper and lower flexible planar sheets, and provides an indication that the replaceable heat transfer module, including the inlet floodbox, and outlet manifold may be folded or rolled into a compact package for shipment as a replacement kit.
FIG. 14 further illustrates the flexible nature of the upper and lower flexible planar sheets, and provides confirmation that the replaceable heat transfer module, including the inlet floodbox, and outlet manifold may be folded or rolled into a compact package for shipment as a replacement kit.
FIG. 15 shows a heat transfer apparatus utilizing a replaceable heat transfer module, showing the adjustably inclinable support tray, and a retractable hood.
In FIG. 16, a sight window provided in the retractable hood portion; several of such windows may be provided (see FIG. 15, for example) to allow an operator to view the working product located on the evaporator envelope during evaporation or product chilling operations.
One embodiment for a pivot joint between the support tray and the retractable hood is illustrated in FIG. 17, which also shows the working product supply line, through which working product is sent to the working product distributor.
In FIG. 18, the closed, working position of the retractable hood is illustrated, showing how the sweep air plenum portion of the retractable hood is brought into close mating relationship with the lateral edges of the support tray, so that sweep air is substantially prevented from escape during countercurrent movement of sweep air from the inlet air plenum to the outlet air plenum of the retractable hood.
FIG. 19 is similar to FIG. 18, also showing the retractable hood in the closed, working position, but now showing the inlet air ducts which provide air to the inlet air plenum, the sweep air plenum wherein sweep air is brought into contact with the working product, the outlet plenum from which the outlet air ducts emerge, and a plurality of drain lines from which condensate or entrained moisture is collected from the outlet air ducts.
In FIG. 20, the inlet end of the support tray is shown, including the inlet floodbox support, as well as a pair of hoses which are connected to a pair of inlets to the inlet floodbox via quick disconnect sanitary fittings.
FIG. 21 provides a perspective photograph of the replaceable heat transfer module in working position on a support tray, and further illustrates the use of a plurality of removable, cleanable tray units, which in this embodiment are each rectangular stainless steel tray units.
FIG. 22 shows the outlet manifold support at the lower end of the support tray, with the outlet manifold supported therein in a working position, with a plurality of outlet hoses affixed to outlets via quick disconnect fittings, and with a vacuum line connected to a vacuum outlet on the upper side portion of the outlet manifold.
FIG. 23 is similar to FIG. 22, but now shows the outlet trough and the outlet nozzle from the product collection trough, and the product outlet hose.
In FIG. 24, additional operating equipment is shown, including a product tank for receiving working product from the product outlet hose just seen in FIG. 23, and a positive displacement pump suitable for pumping a working product through the product supply hose up to the working product distributor.
FIG. 25 shows the use of a toothed latch for a support tray lock, as well as the use of an actuation cylinder to move a retractable locking pin from an engaged, locked position to a retracted, unlocked position.
FIG. 26 illustrates a telescoping safety latch for securing the retractable hood independently of actuators which raise and lower the retractable hood; a nested extensible arm is extended and retracted via a small actuating cylinder to place the safety latch in an extended, locking position, or retract the safety latch into an unlocked position wherein the retractable hood is moveable.
FIG. 27 illustrates the details of portions of one embodiment for a replaceable heat transfer module, specifically illustrating the lower flexible planar sheet and the upper flexible planar sheet and construction details which provide a fluid chamber.
FIG. 28 illustrates the details of yet another embodiment for a replaceable heat transfer module, wherein instead of an overlapping seam as shown in FIG. 1, the outlet ends of the upper flexible planar sheet and the lower flexible planer sheet are spaced apart by a face block on the outlet manifold, and through which face block the heat transfer fluid exits, and against which face block the outlet ends of the upper and lower flexible planar sheets are secured.
FIG. 29 illustrates, in partial view, a downstream view of the face block for an outlet manifold as just depicted in FIG. 28, now showing the individual fluid outlets and the upper and lower flexible planar sheets.
The foregoing figures, being merely exemplary, contain various elements that may be present or omitted from actual implementations and process configurations of the replaceable heat transfer module and the heat transfer module in which the module may be used for heating, evaporation, or cooling, depending upon the circumstances. An attempt has been made to draw the figures in a way that illustrates at least those elements that are significant for an understanding of the various embodiments and aspects of the invention. However, various other elements of the unique replaceable heat transfer module are also shown and briefly described to enable the reader to understand how various features, including optional or alternate features, may be utilized in order to provide a simple, cleanable, sanitary heat transfer module apparatus that can be manufactured in a desired size and configuration for providing a long lasting and superbly performing heating, cooling, or evaporation system.
DETAILED DESCRIPTION
The improvements described and claimed herein relate to methods and apparatus for providing a modular, replaceable, cleanable, sanitary heat transfer module for heating, concentrating or cooling products. More specifically, the improvement described herein is to provide a unique cleanable and replaceable heat transfer module 30, and an improved heat transfer apparatus in which the heat transfer module can be advantageously employed for chilling, heating, or evaporation of a selected working product.
As seen in FIG. 1, the heat transfer module 30 includes an inlet flood box 32, an outlet manifold 34, and an evaporator envelope 36 in a fluid tight relationship therebetween. The heat transfer module 30 is advantageously employed in an adjustably inclinable platform base support tray 40. To assist in achieving the desired heating, cooling, or evaporation result, a retractable hood 42 may be provided for the supply of sweep air 44. As illustrated in this embodiment, sweep air 44 may be configured to move countercurrently to the gravity flow of working product 50 downward across the upper side 51 of an upper sheet 52 of flexible planar material. A lower sheet of flexible planar material 54 is also provided. Each of the upper 52 and lower 54 flexible planar sheets may be provided in a suitable flexible substance. Suitable embodiments include infrared permeable materials, and more preferably, infrared transparent materials. In the embodiment illustrated, the use of a thin polyester, for example, Mylar® brand polyester film, formerly sold by E.I. du Pont de Nemours and Company, and now available from the DuPont joint venture, DuPont Teijin Films, has been taught, since such films are practically transparent to far infrared radiation and thus are advantageous especially for heat transfer applications. Also, such films are suitable for food grade service, and in heating or cooling service, with a variety of working product substances, for example, (a) liquids, or (b) slurries, (c) pumpable high viscosity materials, or (d) any substance or product material where particulates are included in (i) a liquid, (ii) a slurry, or (iii) a pumpable high viscosity material. As a further example, common working products which may be advantageously concentrated may include foods such as fruit or berry mixtures, such as raspberry puree.
The replaceable heat transfer module 30 is useful for providing thermal contact between a first heat transfer fluid 60 such as water, and a working product 50. The first heat transfer fluid 60 and the working product 50 are provided at differing temperatures.
At the upper end 56 of the heat transfer module 30, an inlet floodbox 32 includes at least one inlet 62 for entry (see reference arrow 63 in FIG. 1) of the first heat transfer fluid 60 into the heat transfer module 30. The inlet floodbox 32 includes a plurality of fluid distribution passageways 62 for discharge of the first heat transfer fluid 60.
At the lower end 66 of the heat transfer module 30, an outlet manifold 34 is provided. The outlet manifold includes a plurality of fluid collection passageways 64 for collection of the first heat transfer fluid 60 after the first heat transfer fluid 60 passes through the evaporator envelope 36. The outlet manifold 34 includes at least one outlet 68 through which the first heat transfer fluid 60 is discharged (see reference arrow 69 in FIG. 1). Two outlets 68 can be provided spaced equidistant from first 134 and second 138 ends of outlet manifold 34.
Extending in a fluid tight relationship between the plurality of fluid distribution passageways 62 and the plurality of fluid collection passageways 64, a thin, elongate evaporator envelope 36 is provided. The evaporator envelope has a lower flexible planar sheet 54 and an upper flexible planar sheet 52. The upper flexible planar sheet 52 and said lower flexible planar sheet 54 each having inner surfaces, 72 and 74, respectively, located in a back-to-back spaced apart relationship. In other words, two sheets of Mylar polyester are laid flat one over the other. The evaporator envelope 36 has an upper end 75 wherein the lower 54 and said upper 52 flexible planar sheets are fluidly sealed to the inlet floodbox 32. The evaporator envelope 36 has a lower end 76 wherein the lower 54 and upper 52 planar sheets are fluidly sealed to the outlet manifold 34. As seen in FIG. 27, at a first edge portion 80 and at a second edge portion 82, a narrow strip of the lower flexible planar sheet 54 and a narrow strip of the upper flexible planar sheet 52 are fluidly sealed together. As illustrated in FIG. 27, at the fluid seal along first edge portion 80, a first joint 84 is provided between lower flexible planar sheet 54 and upper flexible planar sheet 52, which is bonded or sealed by use of an adhesive, such as a suitable pressure sensitive adhesive 86, shown slightly extended for purposes of illustration only in FIG. 27. Similarly, at the fluid seal along second edge portion 82, a second joint 88 is provided between lower flexible planar sheet 54 and upper flexible planar sheet 52. The second joint 88 is bonded or sealed by use of an adhesive, such as by using a suitable two sided adhesive tape 86, again shown slightly extended for purposes of illustration only in FIG. 27.
In one embodiment, as shown in FIG. 1, and FIGS. 7–10, and FIG. 27, a tail collection sheet 90 is provided. The tail collection sheet 90 extends, in a downstream direction, past the outlet manifold 34 for a preselected distance D in order to carry a working product 50 to a working product collection pan 94. As illustrated in the embodiment shown in FIGS. 1 and 27, the tail collection sheet 90 is an integral extension of the upper flexible planar sheet 52. In such a situation, the upper flexible planar sheet 52 has an upstream or top end portion 100, and a downstream or bottom end portion 102, and in such a case, the bottom end portion 102 comprises an upstream edge fluidly sealed at a third joint 104 to the top end portion 100. Thus, in this embodiment, the bottom end portion 102 of the upper flexible planar sheet 52 is the component which provides the downstream edge fluidly sealed to the outlet manifold 34. This configuration is illustrated in FIGS. 1 and 27. As shown in FIG. 1, the third joint 104 between the bottom end portion 102 and the top end portion 100 is spaced upstream a preselected distance from the outlet manifold 34. In one embodiment, the preselected distance E is in the range from about 20 centimeters to about one meter.
As see in FIGS. 2 and 3, the fluid distribution passageways 62 in the inlet floodbox 32 are arranged to distribute the first heat transfer fluid 60 substantially uniformly along the upper end 75 of FIG. 1 of the evaporator envelope so that the first heat transfer fluid 60 descends in a continuous film between the inner surfaces 74 and 72 of the lower and upper flexible planar sheets, respectively. The first heat transfer fluid 60 is provided to inlet floodbox 32 via an upflow configuration to at least one inlet 110, and thence through the inlet floodbox 32 past internal baffles 112 (see FIG. 1), and thence to the liquid distribution passageways 62. The internal baffles 112 are oriented to break the force of the first heat transfer fluid 60 entering through each one of the inlets 110 provided, so as to evenly distribute the first heat transfer fluid 60. A pair of inlets 110 can be provided, spaced apart equidistant between first 132 and second 136 ends of the inlet floodbox 32, which is oriented transversely with respect to the flow of the first heat transfer fluid 60, and thus to the length of evaporator envelope 36. As illustrated in FIG. 1, and as perhaps best visualized from FIG. 3, the inlet floodbox 32 has an upper internal headspace 120 which is configured to contain a trapped air bubble, so as to provide for a free weir action of water exiting through the liquid distribution passageways 62. A trough portion 122 provides a liquid reservoir within inlet floodbox 32.
Overall, in one embodiment, the replaceable heat transfer module may be provided in a configuration wherein the lower 54 and said upper 52 flexible planar sheets have a thickness on the order of millimeters or fractions thereof (for example, a polyester sheet with a thickness of about 3 to 8 mils may be useful in some applications). The internal working space for carriage of the first heat transfer fluid 60, between the inner surface 74 of the lower flexible planar member 54 and the inner surface 72 of the upper flexible planar member 52 is of a size on the order of centimeters. The overall evaporator envelope has a length L in FIG. 27, between the inlet floodbox 32 and the outlet manifold 34, on the order of meters, such as in the 4 to 10 meter range, though it may be shorter or longer than this range, depending on the application.
To help secure the working product and avoid loss, in one embodiment as illustrated in FIG. 27, the evaporator envelope 36 has a first marginal width area M1 extending transversely beyond a first end 132 of the inlet floodbox 32 and a first end 134 of the outlet manifold 34, to edge 80. Likewise, on the other side, evaporator envelope 36 has a second marginal width M2 extending transversely beyond a second end 136 of the inlet floodbox 32 and a second end 138 of the outlet manifold 32, out to edge 82. For clarity, in such a case, the evaporator envelope 36 is considered to also include a base 140 of width B1 and which runs, lengthwise substantially between the inlet floodbox and said outlet manifold. In such a situation, as better illustrated in FIGS. 7, 9, and 15, the first marginal width M1 and second marginal width M2 are sized and shaped for sloping outwardly and upwardly from the base width B1 to provide a generally flat bottomed V-shaped trough running from the inlet floodbox 32 to the outlet manifold 34 for containment of a selected working product 50.
As indicated in FIG. 1, the inlet floodbox 32 has inlet upper clamp or clamp plate 150, which secures the upper flexible planar sheet 52 to the inlet floodbox 32. Also, the inlet floodbox 32 has an inlet lower clamp 152, which secures the lower flexible planar sheet 54 to the inlet floodbox 32. As seen in FIG. 6, for example, the inlet lower clamp 152 is secured to the inlet floodbox 32 with a plurality of upwardly protruding fasteners 160. The upwardly protruding fasteners 160 support the upper flexible planar sheet 52 a spaced apart distance from the upper surface 162 of cover plate portion 164, and thus from the plurality of fluid distribution passageways 62, so that the first heat transfer fluid 60 can freely flow from the fluid distribution passageways 62 to the evaporator envelope 36. In one embodiment illustrated, suitable fasteners 160 may be bolts with heads.
In a similar fashion, as shown in FIG. 1, to the inlet floodbox construction, at the outlet manifold 34, an outlet lower clamp 170 is provided which secures the lower flexible planar sheet 54 to the outlet manifold 34. Also provided at the outlet manifold 34 is an outlet upper clamp plate 172 which secures said downstream edge 174 of the bottom end portion 102 of the upper flexible planar sheet to the outlet manifold 34. In one embodiment, the outlet lower clamp 170 is secured to the outlet manifold 34 with a plurality of upwardly protruding fasteners 180. The upwardly protruding fasteners 180 support the lower end portion 102 of the upper flexible planar sheet 52 a spaced apart distance from the upper surface 181 of outlet lower clamp 170 (and thus even further from upper surface 182 of cover plate portion 184 of the outlet manifold 34), and thus from the plurality of fluid collection passageways 64, so that the first heat transfer fluid 60 can freely flow from the evaporator envelope 36 and into the fluid collection passageways 64. Outlets 68 from the outlet manifold 34 can include a quick connect sanitary fitting. Such fittings are useful generally for the inlets 110 also, as well as joints in the working product flow circuit.
Turning now to FIG. 27, the inlet face (plate) cover portion 164 has an upper end 190 and lower end 192, flow-wise, and the liquid distribution passageways 62 are provided closer to the lower end 192 than to said upper end of the inlet face cover portion 164. In one embodiment, this split may be located at roughly one-third of the distance between lower end 192 and upper end 190. Likewise, in the outlet manifold 34, the outlet manifold outlet face (plate) cover portion 184, the liquid collection passageways 64 are provided in the outlet face (plate) cover portion 184. The outlet face cover portion 184 has an upstream 200 end and a downstream end 202, and the liquid collection passageways 64 are provided in the inlet face cover portion 184 closer to the upstream end 200 than to the downstream end 202. Again, in one embodiment, the location of the passageways 64 can be about one third of the way along the inlet face cover portion 184, flow-wise, or on the upstream end.
Although a variety of shapes may be utilized for fluid distribution and collection structures, in one embodiment illustrated for example in FIG. 5, each one of the plurality of fluid distribution passageways 62 and each one of the plurality of fluid collection passageways 64 are configured in a substantially parallelepiped orientation with smooth, rounded corner portions, and wherein the long portion of parallelepiped passageways extends in a side to side orientation with respect to the evaporator envelope 36.
As shown in FIG. 4, the outlet manifold 34 is shaped as an elongate trough having upper edge portions 210 and 212. As indicated in FIGS. 2, 4, and 23, the outlet manifold further includes at least one fluid outlet 214 passageway adjacent at least one of the upper edge 212 which is adapted for vacuum service, so that vacuum may be applied to remove air from the outlet manifold 34 when the outlet manifold is filled with a heat transfer fluid such as hot or chilled water.
When the replaceable heat transfer module 30 is filled with a heat transfer fluid, the evaporator envelope 36 is strong, monocoque structure. However, as seen in FIGS. 13 and 14, the lower 54 and upper 52 flexible planar sheets are sufficiently flexible and resilient that the replaceable heat transfer module 30, when not containing a heat transfer fluid, can be folded or rolled into a compact, shippable package including the evaporator envelope 36, the inlet floodbox 32, and the outlet manifold 34.
Attention is now directed to FIGS. 15 though 26, where further details are shown of an exemplary heat transfer apparatus 300 designed for utilization of the replaceable heat transfer module 30 disclosed above. The heat transfer apparatus 300 has a structural base 302 and an adjustably inclinable support tray 40 that is adjustably affixed to the structural base 302. The adjustably inclinable support tray 40 is sized, shaped, and configured to support in an operational position the replaceable heat transfer module 30 just described. Thus, the inclinable support tray 40 has an inlet floodbox support 310, an outlet manifold support 312, and extending substantially between the inlet floodbox support 310 and the outlet manifold support 312, a generally flat support pan 320 having a length and a width. The replaceable heat transfer module 30 is adjustably affixed to the support tray 40, and tension between the inlet flood box 32 and the outlet manifold 34 may be adjusted as operation begins and or continues.
A retractable hood 42 is provided. The retractable hood 42 includes an air inlet plenum 322, an air outlet plenum 324, and extending between the air inlet plenum 322 and the air outlet plenum 324, a sweep air plenum 326. The sweep air plenum 326 is configured to substantially match the length and width of the inclinable support tray 40. The hood, including the sweep air plenum 326, is retractably affixed to the structural base 302. As illustrated in FIGS. 15, 18, 19, and 21, the sweep air plenum 326 has first 328 and second 330 side portions configured for close fitting mating engagement with the support pan 320, so that air passing through the sweep air plenum 326 is substantially prevented from escaping outward between the sweep air plenum 326 and the support pan 320. Usually (but not necessarily) the inlet air duct 340 and the outlet air duct 342 are arranged for counter-current flow of air with respect to flow of the first heat transfer fluid 60 and the working product 50, which flow co-currently, by gravity. As seen in FIG. 18, the outlet air ducts may include a drain outlet 350, which is configured to trap for discharge any liquids arriving at or condensing in the air outlet duct 342.
As seen in FIG. 1 and FIG. 17, the adjustably inclinable support tray 40 and the retractable hood 42 are pivotally joined at pivot pin 360. As indicated, the support tray 40 and the retractable hood 42 are pivotally joined adjacent the inlet floodbox 32 support. As indicated in FIG. 1, the support tray 40 is adjustable to a selected downwardly sloping angle alpha (a), with respect to a horizontal reference plane 362. In various embodiments, the selected downwardly sloping angle alpha (α) can be established between about 30 degrees and about 45 degrees. However, for a particular application, the selected downwardly sloping angle alpha (α) may be larger than about 45 degrees. Or for other heat transfer situations, the selected downwardly sloping angle alpha (α) may be less than about 30 degrees. For movement of the support tray 40, at least one adjustable support tray actuator 370 is provided. The support tray 40 is adjustably raised and lowered to said preselected angle alpha (α) by movement of the at least one support tray actuator 370. In the embodiment shown in FIG. 18, the at least one adjustable support tray actuator 370 is a telescopic cylinder, which may be provided in a pneumatic or hydraulic actuator. One convenient design is to use air actuated cylinders.
To enhance safety, a support tray lock 366 may be provided. As seen in FIG. 25, one embodiment for such a lock includes a toothed latch 367 and a retractable pin 368. The retractable pin 368 is sized and shaped for movement between (1) a locking position in which the pin rests in the toothed latch 367 to lock the support tray 40 at a selected first position, and (2) a retracted position, in which the support tray 40 can be moved to another desired angle alpha (α). For convenience, the retractable pin 368 is moved by a hydraulic or pneumatic actuator 369.
With respect to the hood 42, as indicated in FIG. 1, the retractable hood 42 is pivotable (at pivot pin 360) to a selected upwardly sloping angle beta (β), with respect to the support tray 40. To raise the hood 42, at least one retractable hood actuator 372 is provided. Thus, the retractable hood actuator 372 is adjustably raised and lowered to a preselected angle beta (β) by movement of the retractable hood actuator(s) 372. Such actuators may be a telescopic cylinder, such as a pneumatic or hydraulic actuator. As seen in FIG. 26, to enhance safety, on structural base 302, a retractable hood safety catch 376 can be provided. The safety catch 376 is movable into a hood 42 support position to secure the retractable hood 42 in an open position independently of the actuators 372. Safety catch actuators 378 can be provided for hydraulically or pneumatically moving the safety catch 376. To see inside of the hood 42 during operation, one or more sight windows 379 can be provided. The sight windows 379 can be sized and shaped to allow viewing of flow of working product along the evaporator envelope 36.
For operation, to distribute working product on the evaporator envelope 36, adjacent the inlet floodbox 32 and in close proximity to the upper flexible planar sheet 52, a working product distributor 380 is provided. The working product distributor 380 configured to distribute a working product 50 on to the upper flexible planar sheet 52, so that the working product 50 may flow by gravity downward along the upper flexible planar sheet 52. At the lower end, a working product collection pan 94 is provided to pick up working product as it leaves the tail collection sheet 90.
Turning now to FIG. 24, details of the method of use are seen. A product tank 400 is fluidly connected to receive working product 50 collected by the working product collection pan 94. A positive displacement pump 402 is provided, wherein the pump 402 has an inlet 404 configured to receive working product 50 from the product tank 400, and an outlet 406 configured to discharge working product 50 to the working product distributor 380.
As seen in FIG. 21, and noted schematically in FIG. 27, the evaporator envelope 36 has a first marginal width M1 extending transversely beyond the first end of the inlet floodbox and the first end of the outlet manifold, and lengthwise from the inlet floodbox to the outlet manifold. Also, a second marginal width M2 is provided between the second end of the inlet floodbox and the second end of the outlet manifold, and lengthwise between the inlet floodbox and the outlet manifold. Since the support tray 40 has, transversely, upwardly and outwardly extending sidewall portions 410 and 412 that extend from lateral edges of the support pan 320, the sidewall portions 410 and 412 are configured to provide a generally flat trough with sloping sides to carry working product. Thus, the evaporator envelope 36 conforms to such shape, since the marginal width M1 and M2 of the evaporator envelope are sized and shaped to generally match the sidewall portions 410 and 412 and thus the evaporator envelope slopes outwardly and upwardly from the support pan 320. As seen in FIG. 21, the support pan portion 320 of the support tray 40 can be provided with a plurality of removable, cleanable tray portions 420.
Turning now to FIG. 28, the details of yet another embodiment for a replaceable heat transfer module 30′ are shown, Here, a face block 422, is provided for outlet module 34′. Instead of an overlapping seam for the bottom of the heat transfer envelope, as shown in FIG. 1, the outlet end 52O of the upper flexible planar sheet and the outlet end 54O of the lower flexible planer sheet are spaced apart by a face block 422 on the outlet manifold 34′. The heat transfer fluid 60 passes through and exits outward via orifices 423, defined by edge walls 424. Heat transfer fluid 60 thence flows into the interior of outlet manifold 34′. In this embodiment, the outlet end 54O of the lower flexible planar sheet 54′ is secured against seal face 425 by a lip 426 of face block 422 and fasteners such as bolts 180′ and accompanying nuts 181′. The orifices 423 and their edge walls 424 are better seen in FIG. 29. Also seen in FIG. 29 is how fasteners 180′ secure lip 426 against lower planar sheet 54′. Likewise, the lower end 52O of the upper flexible planar sheet 52′ is secured against sealing face 428 on face block by outlet upper clamp 172′, which has a lower side 430 which presses against lower end 52O of the upper flexible planar sheet 52′, and thence into the sealing face 428 of block 422. Thus, in this fashion,
The heat transfer apparatus 300 provides a tool for practice of a process for evaporation of liquid from a working product 50. The working product can be a liquid, or a slurry, or pumpable high viscosity material, or any substance or product material where particulates are included in a liquid, a slurry, or a pumpable high viscosity material. The process involves providing a heat transfer apparatus as described herein, including a retractable hood as set forth herein, and placing the hood in a working location in close proximity to the support tray, configured to substantially preclude sweep air from escaping. A first heat transfer fluid, such as hot water, is introduced into the inlet floodbox. A flow of the first heat transfer fluid at a preselected inlet temperature is established. A working product is distributed on the evaporator envelope. The working product is allowed to flow by gravity to a working product collection pan. Solvent removed from the working product is captured in a sweep air stream running countercurrent to the flow of the working product. The angle alpha of the support tray 40 can be adjusted to maintain desired throughput and concentration or dryness of the working product. In one embodiment the process may be utilized on a food material. Food materials especially suited for processing in the apparatus include fruit mixtures, or berry mixtures, or juices. As a further enhancement, the sweep air stream may be conditioned to a desired temperature and humidity level to assist removal of solvent from the working product. Or, the sweep air stream may be simply ambient air, if suitable.
In yet another embodiment, a working product may be chilled in the heat transfer apparatus 300. In such a case, the first heat transfer fluid may be chilled water or a suitable brine composition. As when the heat transfer apparatus is utilized for heating or drying, when chilling is desired, the sweep air stream may be conditioned to a desired temperature and humidity level to assist I in chilling of the selected working product.
Although various aspects and elements of the invention are herein disclosed for illustrative purposes, it is to be understood that the replaceable heat transfer module, and the method of use of the replaceable heat transfer module in thin film heating, drying, evaporation, and chilling systems, are important improvements in the state of the art of devices and methods for handling materials in thin film heat transfer systems with cleanable, sanitary, replaceable heat transfer components. Although only a few exemplary aspects have been described in detail, various details are sufficiently set forth in the figures of the drawing and in the specification provided herein to enable one of ordinary skill in the art to make and use the invention(s), which need not be further described by additional writing in this detailed description. Importantly, the aspects and embodiments described and claimed herein may be modified from those shown without materially departing from the novel teachings and advantages provided as described herein, and may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is especially pointed out that the size, and extent of a desirable heat transfer module, and especially the shapes for liquid distributors and liquid collectors, or the length and width of an evaporation envelope, and the amount of material handled thereby, will vary widely based on the nature of the working products provided, and based on the chilling, heating, or evaporation conditions used, especially when a residual solvent (such as water) is removed. Therefore, the embodiments presented herein are to be considered in all respects as illustrative and not restrictive. As such, this disclosure is intended to cover the structures described herein and not only structural equivalents thereof, but also equivalent structures. Numerous modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention(s) may be practiced otherwise than as specifically described herein. Thus, the scope of the invention(s) is as described herein and as set forth in the appended claims, and as indicated by the drawing and by the foregoing description, is intended to include variations from the embodiments provided which are nevertheless described by the broad interpretation and range properly afforded to the plain meaning of the language of the claims set forth below.
Patent Grant
6990748
