Patent Description:
In preparing foods or other items in bulk, the items may be conveyed through a processing chamber using a conveyor belt. A process, such as heating, cooling or steaming of the articles may be performed. For example, it may be desirable to pasteurize nuts, such as almonds, in bulk using a conveyor belt. Pasteurization may involve heating and -or cooling the nuts using heated or cooled air circulated over the conveyed nuts. It may be desirable to enhance the flow of air in certain processing chambers to make the processing of articles more efficient.

<CIT> discloses a conveyer oven. Foods are carried into a heating chamber by a conveyer and conveyed to the upper portion of the heating chamber. While the foods are conveyed at the upper portion of the heating chamber, an eject nozzle blows hot air to the foods and simultaneously foods are surrounded with remaining hot air. When cooking is finished, the foods are conveyed downward to be carried out from the heating chamber. Therefore, heat from a heating means is used for cooking.

In a first aspect of the present invention there is provided a bulk processor for an item, comprising a processing chamber having a product inlet and a product outlet; a conveyor for conveying product through the processing chamber from the product inlet to the product outlet; and an axial flow fan for circulating air around the product, the axial flow fan having a curved back wall forming an air flow chamber for directing air from below the conveyor to a high-pressure region above the conveyor.

These features and aspects of the invention, as well as its advantages, are described in more detail in the following description, appended claims, and accompanying drawings, in which:.

A processor <NUM> that operates according to and embodies features of the invention is shown in <FIG>. The processor <NUM> changes the temperature of an item conveyed through the processor. For example, the processor can be used to raise the temperature of nuts being pasteurized, pasteurize nuts using steam, dry pasteurized nuts, cool pasteurized nuts or perform any suitable process on any suitable article, not limited to nuts.

The illustrative processor <NUM> comprises a chamber <NUM> with an entrance <NUM> for items to be processed at one end and an exit <NUM> for the processed items at an opposite end. A conveyor belt <NUM> receives items at the infeed <NUM> of the conveyor belt and conveys the items along a processing path, where a process, such as heating, cooling or steam pasteurizing, is performed on the items. The processed product exits the chamber at exit <NUM> and the conveyor belt reverses at outfeed <NUM> to return to the infeed via a returnway path. In one embodiment, the belt is a foraminous belt with sufficient opening to allow airflow therethrough. The conveyor belt <NUM> is trained around drive <NUM> and idle sprockets <NUM> at opposite ends of an upper carryway that traverses the processor, and driven by a motor or other suitable drive. Diverting rollers or drums <NUM> or other guides guide the endless conveyor belt <NUM> along a returnway below the carryway. The illustrative returnway is outside of and below the chamber <NUM>, but the invention is not so limited. The conveyor belt may include repositioning flips formed by repositioning rollers (not shown) along the upper carryway, as described in <CIT> and <CIT>.

The invention is not limited to the illustrative conveyor belt and any suitable means can be used to convey articles through the processor, even conveyors without endless conveyor belts.

The processing chamber <NUM> includes a plurality of air circulators, shown as axial flow fans <NUM>, for circulating air along an air flow path that intersects items being conveyed atop the conveyor belt <NUM> along the carryway. The illustrative conveyor belt <NUM> is foraminous to allow the air to pass through. Other features of such a processor as described thus far are given in <CIT>, and <CIT>, entitled "Low-Temperature, Forced-Convection, Steam-Heating of Nuts", and <CIT> entitled "Bulk Food Processor with Angled Fan".

One example of such a cooker is the CoolSteam® cooker manufactured and sold by Laitram Machinery, Inc. , of Harahan, Louisiana, U.

The axial flow fan <NUM>, driven by a motor <NUM>, pulls air from a lower region <NUM> below the conveyor belt <NUM>, and pushes air up into an air flow chamber <NUM> on the side of the processing chamber <NUM>. As used herein, an axial flow fan, or an axial fan, as opposed to a radial or centrifugal fan, refers to an air circulator that causes air to move in a direction parallel to the shaft about which the fan blades rotate. However, the processor is not limited to an axial fan, and any suitable air circulator, including, but not limited to, radial or centrifugal fans, may be used to circulate air or another fluid through the illustrative processing chamber <NUM>.

The illustrative air flow chamber <NUM> extends up the side of the processing chamber <NUM>, forming a portion of the side wall of the processing chamber <NUM>. The illustrative axial flow chamber <NUM> includes portions within the processing chamber <NUM> and portions that extend beyond the side wall of the processing chamber.

The top of the processing chamber <NUM> can shaped to direct the airflow over the product on the conveyor belt <NUM>. The region <NUM> above the conveyor belt forms a high pressure region, while the region below the conveyor belt <NUM> forms a lower pressure region <NUM>. Air is pushed through the foraminous conveyor belt <NUM> into the low-pressure region <NUM> below the conveyor belt and continues to circulate to process conveyed product. The processing chamber <NUM> also includes an exhaust <NUM> for releasing air to the ambient, if necessary.

In one embodiment, the exhaust <NUM> pulls air from the bottom chamber <NUM>, i.e., the low-pressure region of the chamber <NUM>. The illustrative inlet to the exhaust pipe is below the conveyor belt, so that lower-pressure air is exhausted. The exhaust <NUM> can be a powered exhaust that pulls air from the low-pressure chamber and releases it to the environment using a fan or other suitable device, though the invention is not so limited.

The air circulated by the axial flow fan <NUM> may be heated, cooled, or at ambient temperature. In the illustrative embodiment, the processing chamber <NUM> includes heaters <NUM> for heating the circulated air, the details of which are described below.

The upper, high pressure chamber <NUM> above the conveyor belt includes baffles <NUM>, <NUM> for mixing the circulated air and directing an even flow of air over the conveyor belt <NUM>. In one embodiment, the baffles <NUM>, <NUM> comprise offset sheets of metal connected to and hanging from the top of the chamber <NUM> and extending in a longitudinal direction above the conveyor. Each baffle <NUM>, <NUM> has a wavy shape, with the crests of a first baffle <NUM> offset from the crests of a second baffle <NUM>. In this manner, some of the air blown by the fan <NUM> is deflected by the first baffle and over the product, some of the air passing through the baffle <NUM> is deflected down by the second baffle <NUM> and the remaining air passing through the second baffle <NUM> is deflected down over the product by the side wall of the chamber <NUM>. While the illustrative baffles <NUM>, <NUM> have a sinusoidal shape, the invention is not so limited. For example, the baffles <NUM>, <NUM> could be perforated sheet metal with offset openings, a number of smaller sheets arranged and spaced apart to direct air flow or have any other suitable configuration for providing an evenly mixed flow of air over a product. The baffles <NUM>, <NUM> may have any suitable location, size and shape and be mounted to any suitable component in the chamber <NUM>.

The illustrative axial flow fan <NUM>, shown in detail in <FIG>, may be mounted in a door <NUM> of the processing chamber <NUM> to facilitate access to the axial flow fan <NUM> for cleaning, replacement, repair, testing or any other reason. The illustrative axial flow fan is mounted obliquely in the door <NUM>, with the fan motor <NUM> extending obliquely through the door <NUM> and into the lower portion of the processing chamber. The axial flow fan <NUM> and motor <NUM> may be mounted at any suitable angle to facilitate airflow through the air flow chamber <NUM> extending from the fan inlet <NUM> below the conveyor belt <NUM> to the fan outlet <NUM> above the conveyor belt. The illustrative door <NUM>, comprising a planar base member designed to fit in an opening in the processing chamber and having an opening for mounting the axial flow fan <NUM>, may be hingedly or otherwise movably connected to the side wall of the chamber <NUM> and a latch <NUM> may be used to latch the door in a closed position during operation. The door may have any suitable size, shape, configuration and location, and is not limited to the illustrative embodiment.

In one embodiment, the axial flow fan <NUM> and motor <NUM> are tilted inward at an angle between about <NUM>° and about <NUM>° and preferably about <NUM>°, though the invention is not so limited. The axial flow fan <NUM> has a shroud <NUM> that extends to and interfaces with the lower portion <NUM> of the processing chamber <NUM> at an angle, so that the bottom of the fan inlet 59b is closer to the door <NUM> than the top of the fan inlet 59a. The propeller portion <NUM> of the axial flow fan <NUM> is mounted at the inlet to the shroud <NUM> at the oblique angle.

The air flow chamber <NUM> includes a curved back wall <NUM> to facilitate air flow. The curved back wall <NUM> extends beyond the outside wall of the planar member defining the base of the door <NUM>. The illustrative back wall <NUM> curves about <NUM>° from the bottom of the door <NUM> to the top of the door. On the inside of the door <NUM>, the top portion of the axial flow chamber <NUM> extends up and inward at an angle and includes a rectangular outlet <NUM> pointing into the high pressure region <NUM> at an angle. The outlet <NUM> may include flow straighteners. The interior portion of the air flow chamber <NUM> includes triangular side walls <NUM> extending from an interior wall of the door planar member and an angled front wall <NUM> having a lower curved edge intersecting the shroud <NUM> and an upper edge forming a wall of the outlet <NUM>.

The portion of the air flow chamber that extends outside of the door <NUM> is formed by the curved back wall <NUM> and shaped side walls <NUM> connecting the curved back wall to the door. A cut out in the air flow chamber <NUM> is formed by shaped walls <NUM> and accommodates the axial fan motor <NUM>. The illustrative cut out has the shape of an upside down, truncated tear drop, but the invention is not so limited. The resulting air flow chamber <NUM> produces enhanced, well-mixed, even air flow into the upper portion of the processing chamber <NUM>.

<FIG> show an embodiment of a propeller portion of the axial fan <NUM>. The illustrative propeller portion <NUM> of the axial fan <NUM> comprises a front hub plate <NUM> facing the lower chamber <NUM>, a rear hub plate <NUM> facing the air flow chamber <NUM> and a plurality of blades <NUM> mounted to and extending between front and rear hub plates <NUM> and <NUM>.

Each hub plate <NUM>, <NUM> comprises a central opening <NUM> for receiving and clamping onto an axle from the motor <NUM>. A plurality of petals <NUM> extend radially and are distributed about the periphery of each hub plate. As shown in <FIG>, each petal <NUM> comprises a narrow neck <NUM> and a wider body defined by a flat side edge <NUM> including a plurality of openings <NUM> for receiving fasteners, such as rivets, to fasten a blade <NUM> to the hub plate. A radially outer flat edge <NUM> transitions to a curved side edge <NUM>. The curved side edge <NUM> includes an inner indent <NUM> for accommodating a radially inner corner of an adjacent petal flat side edge.

Each blade <NUM> comprises a bent rectangular sheet having a flat first side edge <NUM> with a radially inner portion fastened to the flat side edge <NUM> of a petal <NUM> of the front hub plate <NUM> using fasteners, such as rivets. A second flat side edge <NUM> of the blade <NUM> is fastened to the rear hub plate <NUM> so that the blade extends at an angle between the two hub plates. The front and rear hub plates <NUM>, <NUM> are arranged relative to each other, so that a first side edge <NUM> of a first blade <NUM> can be mounted to a flat side edge <NUM> of a petal on the front hub plate <NUM>, while the second side edge <NUM> of the blade <NUM> is mounted to a flat side edge <NUM> of a petal <NUM> on the rear hub plate <NUM>. The propeller portion of the axial fan <NUM> is not limited to the propeller <NUM> shown in <FIG> and any suitable fan, including a non-axial fan, may be used to circulate air in the processor <NUM>.

The axial fan <NUM> can also include flow straighteners <NUM>, as shown in <FIG>. The illustrative flow straighteners <NUM> are formed of bent sheet metal, but the invention is not so limited. <FIG> also shows the axle <NUM> extending from the motor through the shroud <NUM> for driving the propeller <NUM>.

As described above, the illustrative processor <NUM> includes a heater <NUM> for heating the circulated air to process a product. <FIG> show an embodiment of a suitable heater <NUM> for heating circulated air, though the invention is not limited to the illustrative heater <NUM>. The illustrative heater <NUM> comprises a natural gas burner with flow distributers mounted in the side wall <NUM> of the chamber <NUM> opposite the axial fan inlet <NUM>, below the conveyor belt. The heater <NUM> includes a housing <NUM> mounted outside the chamber <NUM> that houses motors, valves, fuel supply and other components required to combust a fuel to generate heat. A flame tube <NUM>, where combustion occurs, extends from the housing <NUM>, through the side wall <NUM> of the processing chamber <NUM> and into the interior of the lower portion <NUM> of the chamber <NUM>. Alternatively, the heater can be mounted in a different location, and is not limited to a location below the conveyor <NUM>.

The heater <NUM> further includes an inner shroud <NUM> for the flame tube <NUM>. An outer shroud <NUM> surrounds the inner shroud <NUM>, and is longer than the inner shroud, so that the exit of the outer shroud extends farther into the chamber <NUM>. The shrouds may increase the pressure in the combustion region of the heater to facilitate combustion. The inner shroud <NUM> is a cylindrical tube forming an inner heat chamber. The inner shroud <NUM> extends inwards from the side wall <NUM> and has a plurality of peripheral openings <NUM> for directing heat into the space between the inner shroud and the outer shroud <NUM>. A heat barrier plate <NUM> surrounds the flame tube and blocks heat from passing back towards the side wall <NUM>. A series of baffle plates <NUM>, <NUM>, <NUM>, <NUM> are arranged between the interior facing end of the inner shroud <NUM> and the interior facing end of the outer shroud <NUM>. The baffle plates include openings to fully mix heated air from the flame tube <NUM>. Spacing pins <NUM> connect the baffle plates <NUM>, <NUM>, <NUM>, <NUM> together, as described below.

The processing chamber side wall <NUM> includes an opening <NUM> sized and configured to mount the outer shroud <NUM>. An air flow plate <NUM> surrounds the opening <NUM> on the exterior of the wall <NUM> and is mounted to the wall <NUM> using fasteners <NUM>. An embodiment of the air flow plate <NUM> is shown in <FIG>. An outer mounting plate <NUM> receives the heater housing <NUM> and connects the heater housing <NUM> to the air flow plate <NUM>. The outer mounting plate <NUM> is connected to spacers <NUM> via fasteners <NUM>, and the spacers <NUM> connect to the air flow plate fasteners <NUM> to create openings <NUM> for air intake into the interior space within the outer shroud <NUM>. Any suitable means for forming intake openings may be used, and the invention is not limited to the illustrative means. As described above, the processor includes an exhaust <NUM> to balance for the air pulled into the chamber via the heater <NUM>.

In one embodiment, the housing <NUM> and components therein and flame tube <NUM> comprise a compact burner unit available from Max Weishaupt GmbH of Schwendi, Germany, a burner available from Honeywell Eclipse™ or another burner known in the art, though the invention is not so limited. The heater could comprise any heat source, including, but not limited to, an electric heat source, a natural gas heat source, a propane heat source, an oil heat source or other available heat source.

Referring to <FIG>, the air flow plate <NUM> comprises a central hub <NUM> having a central opening <NUM> for receiving the flame tube <NUM>. The central hub <NUM> includes peripheral slots <NUM> for receiving mounting tabs of the inner shroud <NUM>. The central hub <NUM> further includes radial slots <NUM> for receiving spacing pins <NUM> (shown in <FIG>) to connect and space the heat barrier plate <NUM> and the air flow plate <NUM>. Flexible spokes <NUM> connect the central hub <NUM> to an outer rim <NUM>, which includes openings <NUM> for receiving the fasteners <NUM> to mount the air flow plate <NUM> to the processing chamber side wall <NUM> and spacers <NUM>. While the illustrative air flow plate <NUM>, outer mounting plate <NUM> and heat barrier plate <NUM> are disc-shaped, the invention is not limited to the illustrative shape, and the shape can vary, depending in particular on the size and shape of the side wall opening <NUM>.

Referring to <FIG>, the baffle plates <NUM>, <NUM>, <NUM>, <NUM> promote air mixing while protecting the flame tube from contamination. The baffle plates <NUM>, <NUM>, <NUM>, <NUM> overlap each other and are configured to prevent a straight path through the series of baffle plates. Each plate comprises a basic disc shape with openings to allow air flow. The openings of each baffle plate preferably align with a solid portion of another baffle plate, so that heated air passing through an opening is redirected by a subsequent baffle plate.

A first baffle plate <NUM>, shown in <FIG>, has an inner rim <NUM> with peripheral slots <NUM> for receiving mounting tabs on the inner shroud <NUM> to mount the first baffle plate <NUM> to the inner shroud. Outer spokes <NUM> radiate from the inner rim <NUM> to the inner surface of the outer shroud <NUM> to provide baffling between the inner shroud and outer shroud. Inner spokes <NUM> extend between the inner rim <NUM> and center disc <NUM>, forming openings <NUM> for airflow. Two of the inner spokes 193a, 193b connect to the center disc <NUM>, with an arc-shaped space <NUM> formed between the inner tips of the other inner spokes <NUM>. In one embodiment, the remaining inner spokes <NUM> are not connected near the center to allow the material to expand when exposed to the high temperature from the flame tube <NUM>, but the invention is not so limited. The illustrative center disc portion <NUM> includes an opening holding two thin discs to reduce vibration caused by air flow. Radial slots <NUM> are provided in certain spokes to receive mounting and spacing pins <NUM> to connect the baffle plates <NUM>, <NUM>, <NUM>, <NUM> together.

Referring to <FIG>, a second baffle plate <NUM> includes a substantially solid hub <NUM>, with radial slots <NUM> for receiving pins <NUM> and spokes <NUM> radiating from the solid hub <NUM>. The spokes <NUM> are offset from the spokes <NUM> of the first baffle plate <NUM>, so that air flowing between the spokes <NUM> hits the spokes <NUM>, causing mixing of the air.

Referring to <FIG>, a third baffle plate <NUM> comprises a disc having a pattern of openings <NUM> that align with the solid portions of the second baffle plate. The open areas of the second baffle plate <NUM> align with the solid portions of third baffle plate <NUM>. The third baffle plate also includes radial slots <NUM> for receiving pins <NUM> to connect the third baffle plate <NUM> to the second baffle plate <NUM>.

Referring to <FIG>, a fourth baffle plate <NUM> comprises a central hub <NUM>, radiating spokes <NUM>, radial slots <NUM> and openings <NUM> in the hub <NUM>. The openings <NUM> are arranged to overlap the solid portions of the third baffle plate <NUM>.

The radial slots <NUM>, <NUM>, <NUM>, <NUM> are aligned and sized progressively smaller to accommodate connecting pins <NUM>. <FIG> shows an embodiment of a connecting pin <NUM> suitable for joining a plurality of heater components together. The pin <NUM> comprises a base <NUM> and a first connecting section <NUM> extending from the base. The first connecting section <NUM> is narrower than the base, so as to fit through radial slots <NUM> while the base <NUM> is larger than the radial slots. A second connecting section <NUM> extends from the first connecting section and is narrower than the first connecting section <NUM> so as to fit through the radial slots <NUM> of the second baffle plate <NUM>. A third connecting section <NUM> extends from the second connecting section <NUM> and is narrower than the second connecting section so as to fit through the radial slots <NUM> of the third baffle plate <NUM>. A tip <NUM> extends from the third connecting section <NUM> and is narrower than the third connecting section so as to fit through the radial slots <NUM> of the fourth baffle plate <NUM>. Each connecting section includes upper and lower slits <NUM> forming locking tabs <NUM> near the step formed between each section.

Referring back to <FIG>, the connecting pins <NUM> hold the baffle plates <NUM>, <NUM>, <NUM>, <NUM> in position relative to each other. After insertion through a baffle plate, the associated locking tabs <NUM> are bent in opposite directions to lock the connecting pin relative to the baffle plate.

The other connecting pins <NUM> for connecting and spacing the heat barrier plate <NUM> and the air flow plate <NUM> also each includes a base, movable tabs and stepped down connecting sections to lock the air flow plate <NUM> to the heat barrier plate <NUM>.

In one embodiment, the connecting pins <NUM>, <NUM> and other components of the processor that are exposed to high temperatures may comprise a high-temperature metal, such as INCONEL®, available from Special Metals Corporation of New Hartford, NY. The connecting pins <NUM>, <NUM> may be laser cut to form the desired shapes and configurations.

In one embodiment, a plurality of processors may be used together to pasteurize a product, such as almonds or other nuts. A first processor with an angled axial fan may receive raw almonds from an input, such as a hopper, and circulate warm air over the raw almonds as they are conveyed through the first processor, to pre-heat the almonds. The first processor passes the pre-heated almonds to a second processor having an angled axial fan, which uses steam and air combined and blown by the angled axial fan, to pasteurize the almonds as they are conveyed through the second processor. Then, the second processor can pass the pasteurized almonds to a third processor, which can used heated air circulated using an angled axial fan to dry the pasteurized nuts as they are conveyed through the third processor. Finally, a fourth processor, which can used cooled air circulated through a cooling chamber by an angled axial fan, cools the pasteurized, dried nuts as they pass through the cooling chamber.

Claim 1:
A bulk processor (<NUM>) for an item, comprising:
a processing chamber (<NUM>) having a product inlet (<NUM>) and a product outlet (<NUM>);
a conveyor (<NUM>) for conveying product through the processing chamber (<NUM>) from the product inlet (<NUM>) to the product outlet (<NUM>); and
an axial flow fan (<NUM>) for circulating air around the product, the axial flow fan (<NUM>) having a curved back wall (<NUM>) forming an air flow chamber (<NUM>) for directing air from below the conveyor (<NUM>) to a high-pressure region (<NUM>) above the conveyor (<NUM>).