The present invention relates to a dryer apparatus and method and, more specifically, an apparatus and method for drying harvested and processed pistachio nuts to achieve suitable dryness for storage of the nuts while maintaining optimal conditions throughout the drying process for preferred flavor of the processed and dried pistachio nuts.
Pistachio nuts, once harvested, must be processed and dried in a very short period of time in order to preserve freshness and to derive an end result of nuts with desirable organoleptic properties to potential consumers. The drying process for pistachio nuts varies greatly with the type of equipment used, which may range from sun-drying methods to batch drying nuts when subject to heated air. One type of apparatus for drying nuts and grains with heated air is a device that is referenced as a continuous feed vertical dryer, which utilizes large forced-air heaters that push dry air through the dryer device to achieve a desired moisture level of the material being dried. Such dryer devices are typically used for drying gains such as field corn, and are often utilized for drying nuts, including pistachio nuts, without significant modification with concern for specific properties or needs for pistachio nuts being dried and processes. Also, such dryer devices typically have a large internal capacity for drying sizable volume of material in a batch, usually filled in a continuous fill operation in which the entire dryer inner chamber must be filled before it is operational for drying. This construction and fill operation is depicted in
Also, typically, continuous feed vertical dryers are constructed of sheet stock, such as joined pieces of perforated metal sheets, are joined together such that small spaces and joint-seams are exposed as the material passes down through the dryer. This results in the material, or debris associated with the material (such as small twigs mixed with pistachio nuts being dried), being sometimes caught within the spaces/seams and causing a back-up that disrupts flow and/or causes a risk of fire. Finally, typical prior art dryer assemblies are constructed in a ways that mike it difficult to clean or repair the assembly or parts. For example, typical prior art dryers are equaled with bottom rollers that assist with control of the flow of nuts through the dryer. Such rollers, usually constructed of a single elongated paddle style roller, are inserted as a single length of roller seated in wooden yokes. This construction has the disadvantage of being difficult to service in the event the roller breaks or a supporting yoke needs replacing. Typically, such repair is done by removing the roller from the entire apparatus, which requires much time and multiple workers to complete.
There are numerous other deficiencies relating to typical dryer assemblies in relation to drying pistachio nuts. These include difficulties with controlling the flow rate of nuts being introduced into and migrating through the dryer, as well as lack of a way to put out a fire if one occurs in the dryer, resulting in significant financial loss due to damage of a dryer full of nuts. Thus, there is a need for improved structure and processes for drying pistachio nuts. The present invention solves these and other deficiencies that exist with the typical dryer assemblies.
The present invention includes a dryer apparatus for drying pistachio nuts that has a bulkhead with an inner compartment defined by at least an outer wall and an inner wall formed of material that allows forced air through the walls, such as perforated sheet steel. The walls at least partially define an inner compartment that has at least one generally vertical passageway positioned below an infeed chamber. The infeed chamber includes an elongated auger and a batch hopper positioned adjacent the auger, wherein the batch hopper is configured such that at least a portion of the hopper is movable such that the contents of the hopper is equally distributed into the inner passageways along the length of the assembly. IN an embodiment of this invention, the hopper assembly comprises a plurality of hopper gates covering bottom openings of the infeed assembly and positioned above the passageways along the length of the assembly. The hopper gates are moveable to expose the bottom opening to permit the nuts form the hopper to fill the respective passageways substantially equally along the assembly length. The present invention further provides a structure configured to operate in a selectable mode of operation of the infeed assembly, including a batch fill mode and a continuous fill mode. In the batch fill mode, the batch hopper gates are operated between positions below the bottom openings and adjacent the openings so the inner passageways of the dryer are filled evenly along the length of the dryer. In the batch hopper operational mode the assembly may be partially filled in a drying operation because the hopper assembly is configured to evenly fill the dryer chamber from the proximal to the distal end. In the continuous fill mode, the batch hopper is positioned away from the auger such that the dryer is filled with nuts in a sequential sequence beginning at the end nearest the input of nuts. The present invention also provides a structure and operation of a pistachio nut dryer that has a bulkhead constructed as a seamless sidewall of perforated sheet stock such that the nuts freely pass through the inner passageway of the dryer and are not exposed to seams that may catch the nuts or build up debris. This construction also provides ridge guards of a tent structure to cover any seams or exposed edges of the vertical walls of the inner compartment of the dryer.
To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:
While this invention is susceptible of embodiments in many different forms, there are shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
The dryer apparatus improvements according to the preferred embodiment of the present invention apply to a type of dryer that may be referenced as a continuous feed vertical dryer apparatus 10. The apparatus includes an inner compartment assembly 12 formed as a generally vertically-extending passageway 14 that is filled with the materials to be subject to drying, preferably pistachio nuts 16, and a continuous flow of heated dry air is forced through the apparatus and flows through the nuts 16 slowly passing through the vertically-extending passageway 14. The pistachio nuts 16 are processed through the dryer to remove the free and internal water/moisture that resides on the surfaces of the nuts and within the meat and shell of the nuts.
In the preferred form of the present invention, the nuts 16 are continuously supplied into the inner compartment 12 by an infeed assembly 18 located above the generally vertically-extending passageway 14, and the flow of the nuts 16 through the passageway 14 is regulated by a flow mechanism 28 for adjusting the rate of nuts allowed to exit the compartment 12 at the end or bottom of the passageway 14, while large burner assemblies 28 force air, such that heated dry air flows through the inner compartment 12, thus resulting in a drying process of the pistachio nuts 16. The flow mechanism 28 for adjusting the flow rate through the compartment 12 utilizes multiple possible mechanical arrangements to provide an adjustable opening of a gate structure 30 located at the bottom of the compartment 12. In the preferred embodiment, the gate structure 30 includes a gated opening 32 that allows only a limited flow of nuts in a given period of time. In the embodiment shown in the Figures, the gate 30 is primarily made up of a large plate structure 34 that is positioned over an open end 36 of the passageway 14, thus forming a slide gate assembly 38 associated with each passageway 14 of the compartment 12 (see
In the preferred form of the invention, the flow mechanism 28 includes, in addition to adjustable gates 30 with gate openings 32, an outfeed roller 39 to mechanically control the rate of nuts 16 that move through and exit the inner compartment 12. In the preferred embodiment, the outfeed roller 39, as is described further herein and shown in FIGS. 3 and 10-11, includes a compartmentalized roller assembly that rotates on an arrangement of split saddle bearing 40 mounted to the inner compartment 12 adjacent the gate assemblies 38.
In a preferred embodiment, the parts of the flow mechanism 28, including the gated opening 32 and the outfeed rollers 39, are independently adjusted to achieve an optimal and desired flow rate of nuts 16 passing through the passageway 14, preferably at an optimal flow rate in the range of approximately 4,000 to 6,000 pounds of nuts per hour, and most preferably approximately 5,000 pounds of nuts per hour with the dyer size and arrangement show in the Figures, which is referenced as a “single stack” dryer arrangement. Other flow rates may also be acceptable, depending on the volume of nuts to be processed, the speed of nuts being delivered at the infeed assembly 18, the moisture content of the nuts located at the bottom of the passageway 14 and/or expelled from the gated opening 32, the moisture level of the nuts at the infeed assembly 18, and the temperature in the passageway 14. In a preferred form of the invention, the flow rate of nuts 16 achieved by adjustment of the flow mechanism 39 is established by measurement of the moisture content of the nuts at the bottom of the inner compartment and/or the nuts exiting the assembly 10. The processed nuts at the end of the passageway 14 are allowed to exit the dryer 10 for subsequent storage, must be in the range of less than 6% moisture, to prevent spoiling while in storage. Further, in the preferred form of the invention, the nuts 16 are not subject to temperatures in excess of 140 degrees Fahrenheit, as it is known that exposure to such elevated temperatures may negatively impact qualities of a pistachio nut, such as the preferred taste perceived by a consumer. As is described herein, to achieve optimal drying conditions and desired flow rate, the present invention provides an optimal combination of an assembly with proportioned infeed of nuts 16, a smooth flow of nuts 16 within the inner compartment 12, adjustable and reliable control of the flow of nuts 16 through the apparatus, and adjustable drying functions for smaller batches of nuts 16 being processes.
The vertical-extending passageways 14 of the apparatus 10 are preferably formed as separate compartments along the length of the apparatus 10, and each formed from bulkhead walls 20 of perforated sheet stock 22 formed in an arrangement of a plurality of chambers 24 that are joined by a vertically-extending seam 26. Each passageway compartment 14 has an inner space 41 extending between bulkhead walls 20, formed of four bulkhead walls 20 of perforated sheet stock—namely, an outer wall 42 and inner wall 44 and a pair of generally-opposed end walls, either as a dividing wall 46 or, such as the case with the passageway at each end of the dryer 10, an end wall 48. In this arrangement, the row of vertically-extending passageways 14 collectively form the inner compartment 12 of the dryer as separately-defined inner spaces 40 for passage of the pistachio nuts 16 between perforated sheet stock 22 of the bulkhead walls 42, 44, 46, 48. In the preferred embodiment, there are two generally-opposed groupings of passageways 14, such as shown in
In the preferred form of the invention, the plenum 52 includes an upper plenum chamber 56 and a lower plenum chamber 58, thus dividing the inner plenum 52 into two portions. In one embodiment, such as is shown in the Figures, the upper plenum chamber 56 and the lower plenum chamber 58 are substantially the same size, and are divided into two entirely separate chambers by a dividing wall 59, with the lower plenum chamber 58 being in fluid communication with a lower half of the inner compartment 12.
Each portion of the plenum 52 is in fluid communication with a burner apparatus 60, which is generally comprised of at least one gas burner and a blower associated with each burner. In the preferred embodiment shown in the Figures, an upper burner apparatus 66 is aligned with, and supplies heated dry air directed into, the upper plenum chamber 56. Similarly, a lower burner apparatus 58 is aligned with, and supplies heated dry air directed into, the lower plenum chamber 58. This arrangement of a plenum 52 divided into an upper chamber 56 and lower 58 chamber, with a separate burner apparatus 66, 68 associated with each plenum chamber, provides an advantage of versatility of the dryer apparatus 10. This structure is especially important for operation of the dryer to process a volume of nuts 16 that is less than the full capacity of the inner compartment 12 of the dryer 10—i.e., when the dryer compartment 12 is filled with substantially the same volume of nuts in each portion along the length of the dryer compartment, the lower blower apparatus 68 may be run without the upper burner apparatus 66, thus forcing heated dry air through the lower plenum chamber 58 and through the nuts 16 passing through the lower portion 70 of the vertically-extending passageways 14. In the preferred embodiment of this mode of operation of the dryer 10, the flow of nuts 16 into the dryer compartment 12 is regulated such that the lower portion 70 of each passageway 16, adjacent the lower plenum chamber 58, is filled, and the warm air forced into the lower plenum 58 is forced through the perforated sheet 22 into the inner space 41 of the lower portion 70 of the vertically-extending passageways 14. Further, in this mode of operation of the dryer assembly, the nuts 16 are disbursed across the length of the dryer such that the nuts 16 fill the inner passageways 14 in substantially equal amounts in each passageway 14 along the length of the dryer apparatus.
In a preferred embodiment, the infeed assembly 18 includes an infeed chamber 80 preferably located above the passageways 14. As shown in
Rotation of the helical blade structure of the auger 102 is used to move the nuts 16 from the infeed supply 88 down the span of the infeed chamber 80, thus moving the nuts 16 from the proximal end 92 toward the distal end 96 of the infeed chamber 80. Rotation of the auger 102 is driven by a motor assembly 110 having a motor 112, a drive linkage 114 to transfer rotational torque to the rotor 102, and a gear mechanism 116 which is used to optimize the rotational torque of the motor 112 to achieve the appropriate speed of rotation and resulting torque or force exerted on the auger 102. In an example of a preferred embodiment, a 2-5 horsepower electric motor, which has a typical rotation speed in the range of 1750 revolutions per minute, is fitted with a gear mechanism 116 to reduce the revolution speed, such that the drive output of the motor assembly 110 is in the range of about 30 to 90 revolutions per minute, and preferably in the range of approximately 60 revolutions per minute. This arrangement, utilizing a gear mechanism 116 as part of the motor assembly 110, provides increased power relative the rotational movement of the auger, as compared to an auger directly driven by a motor such as was typical in the prior art use of grain dryers for nut drying applications, which typically have a drive output in the range of 300 to 400 revolutions per minute.
The auger 102 preferably resides in a middle region of the infeed chamber 80, such that the auger 102 is in contact with the nuts 16 entering the chamber 80 at the proximal end 92, and the auger 102 is then rotated to move the nuts 16 along the elongated length 94 of the chamber 80, toward the distal end 96 of the chamber 80. In a preferred embodiment as shown in
The batch hopper 120 of this embodiment is preferably an elongated tray that is mounted within the chamber 80 on a rotational axis 126 along the length of the hopper 120. The hopper tray 120 is moveable between a first position 128 generally located below the auger 102, and a second position 130 located away from the first position, preferably located to a side of the auger 102. In other words, the hopper 120 is moveable between a first position 128 whereby the side walls receive and contain nuts 16 above the passageways 14 of the heater, to a second position 130 whereby the side walls 122 of the hopper are tilted to dispense or pour the nuts 16 into the passageways 14 of the dryer. This structure provides a batch hopper tray 10 that may be deployed to the first position 118 such that the nuts 16 are loaded into the chamber 80 and transferred down the auger 102 toward the distal end 96 of the chamber 80, and the hopper tray 120 subsequently may be rotated to the second position 130 to fill all of the vertical passageways 14 with nuts 16 generally at the same time and fill rate. This batch-fill operation of the assembly may be continuously repeated to fill the inner passageways 14 along the length of the dryer 10 to a substantially equal level, such as when it is desired to only fill the lower portion 70 of the passageways 14 and utilize the lower burner apparatus 68 to force heated dry air into the lower plenum chamber 58. Such use of the batch hopper tray 120 to fill just the lower portion 70 of the dryer 10 is very beneficial when processing nuts for drying. For example, during early or late parts of the growing/harvesting season, a limited supply of nuts may be processed for drying using the batch hopper 120 to generally evenly fill the dryer, and the optional mode of operation is used wherein only the lower portion 70 of the dryer is filled and subjected to heated dry air from the lower blower 68.
The dryer assembly 10 of this embodiment has alternative modes of operation utilizing the construction of the infeed chamber 80 and the batch hopper 120. In a first mode of filling operation, shown in
In an alternate mode of operation, as shown in
An alternate embodiment is shown in
The hopper tray assembly 252 includes a hopper gate assembly 264 with at least one pivotal gate 266. IN the preferred embodiment, the assembly includes a plurality of gates 266, each having opposed sides 268 and a bottom wall 270. Each gate 266 is configured to pivot about an axis 272 at a pivot pin connection 274. In the embodiment shown in
In the embodiment shown in
In the preferred embodiment of this arrangement, the pivotal gates 266 are moved between positions by a pivot drive assembly 280 comprised of a drive mechanism 282 and an elongated linkage arm 284 secured to the gates 266, with each gate 266 being secured to the linkage arm 284 at a rotatable connection 286. In the embodiment shown in the Figures, the pivot drive assembly 280 includes an opposed (second) drive mechanism 288 (opposed to the first mechanism 282), providing opposed piston drive mechanisms that cooperate to extend and contract in unison. This embodiment provides a positive driving force to move the gates 266 from to alternate sides of the openings 260, when each of the opposed drive mechanisms 282, 288 alternate between extending the linkage arm. Alternatively, this mechanism may provide a positive pulling force to move the gates to respective positions. For example, when the first drive mechanism 282 extends the linkage arm, the gates 266 move to the left of the openings 266 and when the second drive mechanism 288 extends the linkage arm the gates 266 move to the right of the openings 266. Alternatively, the first drive mechanism 282 may be configured to apply a pulling force to draw the linkage arm, such that the gates 266 move to the right of the openings 266.
In a preferred form of this embodiment, the drive assembly 280 includes two sets of opposed drive mechanisms 282, 288, each pair of oppose drive mechanisms located on each side of the gates 266 and secured to a respective one of the gate sides 268 by a rotatable connection 286 to a respective linkage arm 284. This arrangement is shown in the exploded view of
In this embodiment shown in
The controller 140 of the dryer assembly includes the electrical connections to various parts of the dryer 10, such as burner igniters (not shown), burner sensors (not shown), the fill indicator 134, the hopper indicator 138, plenum thermometers (not shown), the infeed motor assembly 110, the outfeed motor assembly 144, and similar electrometrical devises and sensors. The controller 140 preferably includes a computer processing device and a controller interface that are housed within a controller cabinet 146, which has a readable display interface 148 providing information regarding the operation of the dryer 10. In a preferred embodiment, the controller cabinet 146 is in electrical connection with various parts of the dryer by a series of wires or electrical conduit 150 passing from the cabinet 146 to the dryer 10. In an embodiment, the controller cabinet 145 is positioned at a location adjacent, yet separate from, the dryer frame assembly 152. This arrangement of the controller being a distance away from the dryer frame may be preferable to keep the controller at a suitable distance to avoid damage or disruption to the drying operation resulting from vibration, debris or other potentially-adverse conditions at the location of the controller.
A fire suppression system 160 is preferably included at least partially within portions of the dryer 10. In an embodiment of this structure, the fire suppression system includes an upper supply pipe 162 passing along at least an extent of the length of the dryer, preferably two parallel upper pipes 162, located within the infeed chamber 80 and extending along the length of the chamber 80. In an embodiment shown in
In the preferred embodiment of this feature, the fire suppression pipe (with the nozzles 168) is located an upper region of the lower plenum chamber 58 and the upper plenum chamber 56. When activated, such as by detection of a fire and a signal at the computer control located at the control device 140 for the fire suppression feature to be activated, water sprays from the nozzles 168 and is directed toward the nuts 16 that are subject to the detected fire or overheated area.
The bulkhead walls 42, 44, 46 and 48 which form the inner passageway 14 have a unique and beneficial construction of being substantially free of any seams that may potentially catch or snag debris or nuts passing through the passageway 14. This is a significant feature of the present dryer apparatus 10 that is superior over prior art devices which had been formed of segments of sheet stock, linked together and having the top edge of a lower segment exposed within the chamber to potentially catch debris, which leads to risk of fire and other damage to the operation, equipment and the nuts being processed. As is shown in
As shown in FIGS. 3 and 10-11, the outfeed roller 39 includes a roller assembly 200 that includes the roller 39 and an arrangement of split saddle bearings 40 that are mounted in fixed array at the lower portion of the inner compartment 12 of the dryer, adjacent the gate assemblies 38. Thus, the outfeed roller 39 is preferably an elongated roller with a general paddlewheel construction having a plurality of paddle surfaces 202 about a central axis 204. In the preferred form, the roller 39 is comprised of a series of roller length segments that are joined together along the length of the dryer at roller hubs 208, each roller length segment 206 is generally equal to the respective width of the inner passageway 14 in the specific region of the dryer 10, such that each such length segment 206 fits between two vertical walls that define the passageway 14. At least a portion of the length of the roller 39 includes a plurality of hubs 208 that are aligned with saddle bearings 40 to support the roller 39 in position, wherein each hub 208 is allowed to freely rotate to the side of an adjacent saddle bearing 40 such that the roller 39 is maintained in position yet free to rotate along its axis. A central linkage pin 207 is removably secured within an opening 209 along the central axis of the roller. Each central linkage pin 207 includes a roller hub connection 220 for securing the pin to a roller segment 206, and a bearing engagement region 222 configured to mate with a saddle bearing 40 as explained herein and shown in the exploded view of
Significantly, the structure of the present invention allows one to remove the entire roller 39 by simply removing the saddle bearings 40, then sliding the roller out of its position. Openings 224 in the walls of the dryer are dimensioned such that the roller 40 may be freely removed from the dryer 10, once the saddle bearings 40 are removed. Described another way, the present invention provides a dryer apparatus structure that includes openings 224 in the lower portion of the dryer that permits the diameter of the roller 40 (including the diameter of the hubs 208) to be freely inserted into the openings 224, and the saddle bearings 40 are then attached to the dryer to hold the roller 39 in position and allow rotational movement of the roller 39 by the bearing regions 222 rotating on an inner surface 226 of a respective saddle bearing 40
Also, in the preferred embodiment, an access panel 210 is provided in a lower portion of the lower plenum 58 at locations that allow for access to the saddle bearings 40 when the access panel 210 is moved, such as lifting an access panel 210 in
This application is a continuation-in-part of U.S. Non-provisional patent application Ser. No. 12/688,556, filed on Jan. 15, 2010, entitled “Pistachio/Nut Dryer—Assembly and Method,” which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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Parent | 12688556 | Jan 2010 | US |
Child | 14177065 | US |