Patent Description:
Foodstuffs, such as meat carcasses, require effective cooling to preserve the foodstuffs for safe consumption. For example, carcasses typically have a core temperature of about <NUM>-degees C (about <NUM>-degrees F) immediately after slaughtering. The carcass is quickly cooled to a temperature of about <NUM>-<NUM>-degrees C (about <NUM>-<NUM>-degrees F) for biochemical, bacteriological, and physical reasons. Typically, the carcass is placed in a cold environment to effect a heat transfer between the warm carcass and cold air to cool the carcass to the desired temperature.

The carcasses can experience significant weight loss due to evaporation during the chilling process. Forced air movement blows the cold air over the carcasses to accelerate the cooling process and reduce weight loss. Spraying water droplets onto the carcasses can also accelerate the cooling process and reduce weight loss. However, introducing water to the cooling process can delay cooling because freezing of the water on the carcass, floor, walls, ceiling, and other constructions is undesirable, so temperatures above freezing are typically used. In addition, condensation can be formed in the cooling area and drip onto the carcasses, which can lead to bacteriological contamination. Also, the effectiveness of spraying is relatively low as only a small portion (typically about <NUM>%) of the sprayed water is actually effective in reducing weight loss of the carcass.

<CIT> discloses slaughtered poultry conveyed through a chilling room and exposure to a stream of chilling air. During chilling the skin of the poultry is moistened by spraying with water in a spray area that is separated from the stream of chilling air.

<CIT> discloses a method and equipment for processing food products by spraying with water in an electrical field, particularly for scalding and/or chilling of poultry.

<CIT> discloses a method for cooling carcasses and carcass parts of slaughtered animals by applying a liquid mist to the object for cooling and carrying the mist covered object into a gas flow.

According to one aspect of the present invention, there is provided a method of spray chilling according to claim <NUM>.

Said method of spray chilling comprises: generating a chilled primary airflow and blowing the primary airflow into a chilling tunnel;traversing, via a conveyor line, an electrically grounded foodstuff through the chilling tunnel; generating a charged fluid spray;applying the charged fluid spray to the foodstuff; and orienting, via an air guiding baffle, the primary airflow along a first spray axis of a first electrostatic sprayer such that the primary airflow flows generally parallel to the first spray of charged fluid generated by the first electrostatic sprayer.

According to another aspect of the present invention, there is provide a spray chilling system according to claim <NUM>.

Said spray chilling system comprises: a primary blower configured to generate a chilled primary airflow;a conveyor line configured to traverse electrically grounded foodstuff within a chilling tunnel;a plurality of spray modules disposed along the conveyor line and configured to spray charged fluid onto the foodstuff, wherein a first spray module of the plurality of spray modules comprises:a first electrostatic sprayer configured to spray a first charged fluid spray onto the foodstuff; and a first secondary fan disposed between the first electrostatic sprayer and the primary blower, the first secondary fan configured to generate a first subflow of the chilled primary airflow and blow the first subflow towards the first electrostatic sprayer.

<FIG> is a side schematic diagram of spray chilling system <NUM>. <FIG> is a top schematic diagram of spray chilling system <NUM>. <FIG> and <FIG> will be discussed together. Spray chilling system <NUM> includes chilling tunnel <NUM>, primary blower <NUM>, spray modules <NUM>, and conveyor <NUM>. Primary blower <NUM> includes cooling elements <NUM> and primary fans <NUM>. Each spray module <NUM> includes electrostatic sprayers 24a, 24b; secondary fans 26a, 26b (<FIG>); air baffles 28a, 28b (<FIG>); reservoir <NUM> (<FIG>); and hook detector <NUM> (<FIG>). Fluid lines <NUM> (<FIG>) extend between reservoirs <NUM> and electrostatic sprayers 24a, 24b. Conveyor <NUM> includes conveyor slide rail <NUM> and hook <NUM>.

Spray chilling system <NUM> is configured to rapidly cool foodstuff C during processing. For example, spray chilling system <NUM> can rapidly cool a meat carcass after the animal is harvested/slaughtered. Spray chilling system <NUM> conveys foodstuff C through chilling tunnel in direction D and reduces the core temperature of foodstuff C via a chilled air flow and charged fluid sprays. The fluid can be of any type suitable for spraying onto foodstuffs during processing, such as water or water-based solutions such as a solution of sodium chloride or other allowed additives in water. While one foodstuff C is illustrated in <FIG>, it is understood that spray chilling system <NUM> is configured to simultaneously chill multiple foodstuffs.

Chilling tunnel <NUM> is a space configured to chill foodstuffs after harvesting or slaughtering. One or more of conveyor <NUM> extends through chilling tunnel <NUM>. Conveyor is configured to convey foodstuff C through chilling tunnel <NUM>. Hook <NUM> is secured to conveyor slide rail <NUM> and traversed through chilling tunnel <NUM>. Foodstuff C is mounted on hook <NUM>. In the example shown, conveyor <NUM> is an overhead conveyor, but it is understood that conveyor <NUM> can be of any configuration suitable for supporting and conveying one or more meat carcasses C within and through chilling tunnel <NUM>. While conveyor <NUM> is shown as extending straight through chilling tunnel <NUM>, it is understood that conveyor <NUM> can be disposed in any configuration suitable for conveying meat carcasses C within spray chilling system <NUM>.

Primary blower <NUM> is disposed at one end of chilling tunnel <NUM>. In some examples, primary blower <NUM> is disposed proximate the ceiling of chilling tunnel <NUM>. Primary blower <NUM> is configured to generate a chilled primary airflow F1 and to blow that chilled primary airflow F1 into chilling tunnel <NUM>. Chilled primary airflow F1 circulates within chilling tunnel <NUM>. In some examples, the chilled primary air flows the length of cooling tunnel <NUM> along the ceiling of chilling tunnel <NUM> to the wall disposed opposite primary blower <NUM>. The chilled primary air then flows back towards primary blower <NUM> along the floor of chilling tunnel <NUM>, where the chilling primary air is recirculated by primary blower <NUM>.

Cooling elements <NUM> reduce the temperature of the primary airflow. In some examples, cooling elements <NUM> are configured to reduce the temperature of the primary airflow to about <NUM>-degrees C (about <NUM>-degrees F). In some examples, cooling elements <NUM> are configured to chill the primary airflow to a temperature below about <NUM>-degrees C. As such, cooling elements <NUM> can, in some examples, chill the primary airflow to a temperature at or below the freezing point of water. Cooling elements <NUM> can be of any type suitable for reducing the temperature of the primary air to a suitably low temperature for chilling foodstuffs.

Primary fans <NUM> blow the primary airflow chilled by cooling elements <NUM> into chilling tunnel <NUM>. Primary fans <NUM> can be of any type suitably configured for blowing chilled primary airflow F1 through chilling tunnel <NUM>. In some examples, primary fans <NUM> can be configured to generate an airflow having a speed of between about <NUM>-<NUM>/s (about <NUM>-<NUM> ft/s). The velocity of the primary airflow generated by primary fans <NUM> can be altered to any desired velocity based on the requirements of the foodstuff being chilled.

Spray modules <NUM> are disposed at least partially within chilling tunnel <NUM> along the length of conveyor <NUM>. In some examples, the fluid supply, including reservoir <NUM>, is disposed outside of chilling tunnel <NUM> and fluid line <NUM> extends into chilling tunnel <NUM> to electrostatic sprayers 24a, 24b. Spray chilling system <NUM> can include as many or as few spray modules <NUM> as desired. In some example, spray chilling system <NUM> can include more than twenty spray modules <NUM>. In one example, spray chilling system <NUM> includes twenty-four spray modules <NUM>. In another example, spray chilling system <NUM> includes forty-eight spray modules <NUM>. Each spray module <NUM> is configured to generate and apply a spray of charged fluid to foodstuff C as foodstuff C proceeds through a spray area associated with that spray module <NUM>. The spray area is the area within which spray module <NUM> is activated to spray charged fluid droplets onto foodstuff C. For each spray module <NUM>, reservoir <NUM> provides the fluid that is going to be sprayed onto foodstuff C. While each spray module <NUM> is shown as including a dedicated reservoir <NUM>, it is understood that each reservoir <NUM> can be connected to supply fluid to one or more than one spray module <NUM>. Spray module <NUM> is configured to continuously eject charged fluid sprays into the chilled primary airflow F1 so long as foodstuff C is present in the spray area of that spray module <NUM>. Spray module <NUM> can be configured to stop spraying when no foodstuff C is present in the spray area. Each spray module <NUM> is individually controllable.

Fluid supplies provide charged fluid for spraying by electrostatic sprayer 24a, 24b. Reservoirs <NUM> store fluid for spraying by electrostatic sprayers 24a, 24b and the fluid is pumped to electrostatic sprayers 24a, 24b. In some examples, the fluid supply can draw fluid from a grounded source, such as the water grid, supply tank, etc. Reservoir <NUM> can be considered as storing charged fluid for supplying electrostatic sprayers 24a, 24b. Electrostatic sprayers 24a, 24b are fluidly connected to reservoir <NUM> by fluid lines <NUM> to receive fluid from reservoir <NUM>. The fluid is charged to a desired spray voltage and sprayed onto and towards foodstuff C. In some example, the fluid is charged to a potential of at least about <NUM> kilovolts (kV). Charging the fluid to at least 10kV causes the fluid to break apart into extremely small droplets, such as droplets having an average diameter of about <NUM>-<NUM> micrometers, which droplets enhance cooling due to intense evaporation. In some examples, the droplets have an average diameter of about <NUM> micrometers. In some examples, the fluid is charged to a potential of about 10kV-60kV, and more specifically to a potential of about 20kV-50kV. The fluid can be charged in any desired manner, such as by an electrode (not shown) of electrostatic sprayer 24a, 24b, among other options. The fluid is conductive such that the charge can be provided at any desired location along the fluid supply path between the fluid supply and the electrostatic sprayer. For example, the charge can be provided at the fluid supply, along fluid lines <NUM>, or at the electrostatic sprayers 24a, 24b, among other options. Foodstuff C is grounded as it traverses chilling tunnel <NUM>. As such, the charged fluid droplets are attracted to foodstuff C and wrap around and evenly coat foodstuff C.

Electrostatic sprayer 24a is mounted on a first side of conveyor <NUM> and electrostatic sprayer 24b is mounted on a second side of conveyor <NUM>. Electrostatic sprayers 24a, 24b atomize the fluid and eject the fluid in a spray fan, though it is understood that other spray configurations are possible. While each spray module <NUM> is described as including two electrostatic sprayers (electrostatic sprayers 24a, 24b), it is understood that each spray module <NUM> can include as few or as many electrostatic sprayers as desired. For example, each spray module <NUM> can include one, two, three, four, or more electrostatic sprayers. Each of the electrostatic sprayers can be mounted at similar or different angles relative to vertical. In one example, spray module <NUM> includes one or more of electrostatic sprayers 24a, 24b mounted above the foodstuff C and includes one or more of electrostatic sprayers 24a, 24b mounted below or beside foodstuff C. The electrostatic sprayers mounted above foodstuff C can be oriented to spray generally downward and the electrostatic sprayers mounted below foodstuff C can be oriented to spray generally upward.

Electrostatic sprayers 24a, 24b are configured to eject compressed air as secondary airflows to atomize the fluid and generate the sprays. The compressed air is ejected from electrostatic sprayers 24a, 24b as secondary airflows F2. The secondary airflow F2 is configured to break up the charged fluid stream ejected from electrostatic sprayer 24a, 24b and to carry the charged fluid spray away from electrostatic sprayer 24a, 24b. The pressure of the compressed air flowing to each electrostatic sprayer 24a, 24b can be controlled to control the droplet size and the shape and width of the spray pattern generated by electrostatic sprayer 24a, 24b. In some examples, the compressed air is pressurized to at least about <NUM> kilopascal (kPa) (about <NUM> pounds per square inch (psi)), for example, about <NUM>-<NUM> kPa (about <NUM>-43psi). The combination of charged fluid and atomized spray is configured to generate extremely small droplets, such as droplets having a size of about <NUM> micrometers.

As discussed in more detail below, the compressed air can be heated prior to being ejected by electrostatic sprayer 24a, 24b such that the secondary airflow F2 is warmer than the primary airflow F1 to thereby prevent freezing of the fluid when it is sprayed into the colder primary airflow F1. In some examples, the compressed air can be heated to a temperature of about <NUM>-degrees C (about <NUM>-degrees F) or higher. In other examples, the compressed air can be heated to a temperature of about <NUM>-degrees C (about <NUM>-degrees F) or higher.

Electrostatic sprayer 24a is configured to spray the charged fluid along spray axis A-A, and electrostatic sprayer 24b is configured to spray the charged fluid along spray axis B-B. Electrostatic sprayers 24a, 24b are configured to spray generally parallel to the vertical axis on which foodstuff C is hanging. Spray axis A-A is disposed at angle α relative to vertical such that electrostatic sprayer 24a ejects the charged fluid spray along and towards foodstuff C. Similarly, spray axis B-B is disposed at angle θ relative to a vertical axis such that electrostatic sprayer 24b ejects the charged fluid spray along and towards foodstuff C. It is understood that electrostatic sprayers 24a, 24b can be disposed at any desired angle suitable for coating foodstuff C with the charged fluid. In some examples, one or both of angles α and θ can be <NUM> degrees relative to vertical, such that electrostatic sprayers 24a, 24b spray vertically and the electrostatic attraction pulls the charged droplets onto foodstuff C. In other examples, angles α and θ are between about <NUM>-<NUM> degrees, and more specifically between about <NUM>-<NUM> degrees. It is understood, however, that angles α and θ can be of any desired angle depending on a variety of factors, such as the distance of electrostatic sprayers 24a, 24b from foodstuff C, the distance of spray module <NUM> from primary blower <NUM>, and the type of foodstuff being chilled, among other factors.

The chilled primary airflow F1 is relatively turbulent and circulates within chilling tunnel <NUM>. The chilled primary airflow F1 flows transverse to the secondary airflow F2 from electrostatic sprayers 24a, 24b. Secondary fans 26a, 26b and air baffles 28a, 28b are configured to orient the chilled primary airflow F1 at spray module <NUM> to be generally longitudinally along spray axis A-A at electrostatic sprayer 24a and generally longitudinally along spray axis B-B at electrostatic sprayer 24b.

Secondary fans 26a, 26b are mounted above electrostatic sprayers 24a, 24b. As such, electrostatic sprayers 24a, 24b are disposed between secondary fans 26a, 26b and foodstuff C. Secondary fans 26a, 26b are respectively configured to generate first and second subflows of the chilled primary airflow F1. Secondary fans 26a, 26b are configured to redirect the chilled primary airflow F1 and to blow the first and second subflows substantially longitudinally along the vertical hanging axis of the foodstuff C. It is understood, however, that secondary fans 26a, 26b can be disposed at any desired orientation suitable for redirecting primary chilled airflow F1. For example, each of secondary fans 26a, 26b can be canted relative to a horizontal plane such that secondary fans 26a, 26b are aligned to blow the first and second subflows along spray axes A-A and B-B, respectively. Secondary fans 26a, 26b can be of any type suitably configured to generate an airflow, such as axial fans.

Secondary fan 26a can generate the first subflow such that the first subflow has a velocity substantially similar to the velocity of the secondary airflow F2 from electrostatic sprayer 24a. Secondary fan 26b can generate the second subflow such that the second subflow has a velocity substantially similar to the secondary airflow F2 from electrostatic sprayer 24b. As such, the chilled primary airflow F1, which has been redirected into the first and second subflows, and the secondary airflows F2 can have substantially the same air velocities. Matching the air velocities prevents undesired turbulence and enhances the flow of the charged fluid spray towards foodstuff C.

Air baffles 28a, 28b are disposed proximate secondary fans 26a, 26b and electrostatic sprayers 24a, 24b. Air baffles 28a, 28b are disposed downstream of secondary fans 26a, 26b, respectively, to orient and guide the subflows generated by secondary fans 26a, 26b towards and along electrostatic sprayers 24a, 24b, respectively. Air baffles 28a, 28b further prevent diffusion of the subflows. Each air baffle 28a, 28b includes multiple baffles disposed on the inboard and outboard sides of electrostatic sprayers 24a, 24b relative to conveyor <NUM>. Air baffles 28a, 28b can be of any type suitably configured to orient and guide the subflows. Air baffles 28a, 28b can also be disposed at any desired angle relative to spray axes A-A and B-B, respectively, to direct the first and second subflows.

Air baffle 28a orients the first subflow, generated by secondary fan 26a, to flow substantially along spray axis A-A. Air baffle 28b orients the second subflow, generated by secondary fan 26b, to flow substantially along spray axis B-B. Orienting and guiding the subflows ensures that the chilled primary airflow F1 flows generally longitudinally relative to electrostatic sprayers 24a, 24b, thereby ensuring that the charged fluid sprays are sprayed towards foodstuff C.

Hook detectors <NUM> are configured to sense when foodstuff C enters the spray area associated with the spray modules <NUM> associated with that hook detector <NUM>. Spray modules <NUM> are configured to activate and begin spraying based on hook detector <NUM> sensing foodstuff C entering the spray area associated with that spray module <NUM>. For example, hook detector <NUM> can be a Hall Effect sensor, a mechanical sensor actuated by hook <NUM>, or of any other type suitably configured for sensing foodstuff C entering the spray area. Spray chilling system <NUM> can include one or more controllers (not shown) configured to activate and deactivate spray modules <NUM> throughout the spray process. For example, the controller can activate a spray module <NUM> based on a signal from an associated hook detector <NUM> and can deactivate the spray module <NUM> based on a set time period passing, based on a signal from a sensor at the end of the spray area, or based on any other desired factor.

During operation, a foodstuff C is placed on conveyor <NUM> for chilling. For example, foodstuff C can be a meat carcass of a freshly harvested animal can be hung from hook <NUM>. Conveyor slide rail <NUM> pulls hook <NUM>, and thus foodstuff C, through chilling tunnel <NUM>. Primary blower <NUM> generates and blows the chilled primary airflow F1 into chilling tunnel <NUM>.

Hook detector <NUM> senses when foodstuff C enters the spray area associated with spray module <NUM>. Spray module <NUM> is activated based on foodstuff C entering the spray area. Fluid is drawn from a fluid source and pumped to each of electrostatic sprayers 24a, 24b. Electrostatic sprayer 24a ejects a first charged fluid spray along spray axis A-A. Electrostatic sprayer 24b ejects a second charged fluid spray along spray axis B-B. The droplets in each of the first and second charged fluid sprays are attracted to the grounded foodstuff C such that the droplets wrap around and evenly coat the surface of foodstuff C. The small fluid droplets generated by electrostatic sprayers 24a, 24b accelerate the cooling process by evaporating relatively quickly from the surface of foodstuff C. The very small charged droplets generated by electrostatic sprayers 24a, 24b wrap around foodstuff C and crate a thin, homogeneous fluid layer on the surface of foodstuff C. That thin, homogeneous fluid layer also prevents fluid channels from forming on the surface of foodstuff C, which fluid channels can cause discoloration of the foodstuff C.

The intense evaporation and accelerated cooling process reduce weight loss of foodstuff C during the spray chilling process. Electrostatic sprayers 24a, 24b are configured to continuously generate the first and second charged fluid sprays as foodstuff C traverses through the spray area. As such, each spray module <NUM> is configured to continuously eject charged fluid sprays into the chilled primary airflow F1 so long as foodstuff C is present in the spray area of that spray module <NUM>. Spray modules <NUM> can be configured to stop spraying when no foodstuff C is present in the spray area.

Secondary fans 26a, 26b redirect the chilled primary airflow F1 by respectively generating the first and second subflows of chilled primary air. Secondary fans 26a, 26b blow the first and second subflows towards electrostatic sprayers 24a, 24b. Air baffles 28a, 28b orient and guide the first and second subflows towards foodstuff C. Electrostatic sprayers 24a, 24b eject secondary airflows F2 of as part of the charged fluid sprays. The first and second subflows flow generally longitudinally with the secondary airflows F2, such that the first and second subflows further guide the charged fluid sprays towards foodstuff C. As discussed above, secondary fans 26a, 26b can be configured to generate first and second subflows having velocities substantially similar to the secondary airflows F2 generated by electrostatic sprayers 24a, 24b.

Spray module <NUM> stops spraying once foodstuff C passes out of the spray area associated with spray module <NUM>. Conveyor <NUM> continues to traverse foodstuff C through chilling tunnel <NUM> where foodstuff C is intermittently dosed with charged fluid from the multiple spray modules <NUM> in chilling tunnel <NUM>. The relative positioning between spray modules <NUM> and/or speed of conveyor <NUM> can be based on when foodstuff C dries from the previous dosing. As such, foodstuff C is recoated with fluid droplets as soon as foodstuff C becomes dry, thereby further inhibiting weight loss during the chilling process. Foodstuff C continues to traverse chilling tunnel <NUM> until the core temperature has dropped to a desired level.

Spray chilling system <NUM> provides significant advantages. The charged fluid is electrically attracted to the grounded foodstuff, thereby increasing the transfer efficiency of the fluid onto the foodstuff. The charged fluid wraps around and evenly coats the surface of the grounded foodstuff. In some examples, the transfer yield (e.g., the savings on weight loss/total amount of fluid sprayed) increased from about <NUM>% with uncharged fluid to about <NUM>% with charged fluid. For example, a foodstuff C would lose <NUM> (about <NUM> lbs) during the chilling process without spraying but keeps the <NUM> with spraying, as such the savings on weight loss would be <NUM>. If the total liquid sprayed is <NUM> (about <NUM> fl oz), then the transfer yield would be <NUM>%. The transfer efficiency (e.g., the percentage of fluid discharged from electrostatic sprayers 24a, 24b that contributes directly to the reduction of weight loss of the foodstuff C) also increased relative to uncharged water. Increasing the transfer efficiency reduces the amount of condensation depositing in chilling tunnel <NUM> and the amount of fluid droplets floating in the air, thereby producing a more sanitary chilling environment. The increased transfer efficiency also reduces waste, thereby reducing cost. The charged fluid also provides benefits in that the highly charged fluid (charge of 10kV or greater) breaks into extremely small droplets that deposit on the foodstuff. The extremely small droplets evaporate quickly, which accelerates the chilling process. The accelerated cooling process reduces weight loss of the foodstuff that can occur during the chilling process. Spray chilling system <NUM> can effectively chill foodstuff C, including meat carcasses, with weight losses of about <NUM>-<NUM>% compared with weight losses of about <NUM>% with forced air movement and weight loss of about <NUM>-<NUM>% with forced air movement and uncharged water sprays. In addition, the rate of cooling increased about <NUM>-<NUM>% relative to cooling utilizing uncharged fluid. As such, spray chilling system <NUM> quickly cools foodstuff, thereby increasing the amount of foodstuff that can be processed, while limiting any weight losses, thereby increasing the yield of foodstuff during processing.

<FIG> is an isometric view of electrostatic sprayer 24a. <FIG> is a schematic diagram of pneumatic supply system <NUM> for electrostatic sprayer 24a. <FIG> and <FIG> will be discussed together. Electrostatic sprayer <NUM> includes sprayer body <NUM>, power inlet <NUM>, fluid inlet <NUM>, air inlets 48a-48c, and air cap <NUM>. Pneumatic supply system <NUM> includes air source <NUM>, air lines 54a-54c, and heater <NUM>.

Electrostatic sprayer 24a is configured to emit a charged fluid spray during operation of spray chilling system <NUM> (<FIG> and <FIG>). Sprayer body <NUM> can be mounted at any desired location for automatic operation of electrostatic sprayer <NUM>. It is understood, however, that electrostatic sprayer 24a can be of any desired configuration suitable for applying a charged fluid spray to foodstuff C.

Electrostatic sprayer 24a is substantially similar to electrostatic sprayer 24b and it is understood that the discussion of electrostatic sprayer 24a applies equally to electrostatic sprayer 24b. Fluid line <NUM> extends to fluid inlet <NUM> of electrostatic sprayer 24a. Fluid line <NUM> is configured to provide fluid from reservoir <NUM> (<FIG>) to electrostatic sprayer 24a. The fluid is ejected through air cap <NUM>. Power inlet <NUM> of electrostatic sprayer 24a is configured to receive a power cable to provide power to charge an electrode (not shown) of electrostatic sprayer 24a. The electrode projects through air cap <NUM> and is configured to charge the fluid spray. In some examples, electrostatic sprayer 24a does not include a power inlet <NUM> as the charge is applied to the fluid at a location upstream of electrostatic sprayer 24a. Air inlets 48a-48c are connected to pneumatic supply system <NUM> to receive compressed air from pneumatic supply system <NUM>.

Pneumatic supply system <NUM> is configured to provide compressed air to electrostatic sprayer 24a to generate the secondary airflow F2 (<FIG>). Air source <NUM> is configured to compress air and provide the compressed air to electrostatic sprayer 24a. Air source <NUM> can be of any type suitably configured to compress air. Air line 54a extends from air source <NUM> to air inlet 48a to provide a first portion of compressed air to electrostatic sprayer 24a. Air line 54b extends from air source <NUM> to air inlet 48b to provide a second portion of compressed air to electrostatic sprayer 24a. Air line 54c extends from air source <NUM> to air inlet 48c to provide a third portion of compressed air to electrostatic sprayer 24a. In the example shown, the first portion of compressed air is atomizing air that is ejected from air cap <NUM> and breaks up the charged fluid stream and controls droplet size. The second portion of compressed air is fan air that is ejected from air cap <NUM> and controls the shape and width of the spray pattern. The third portion of compressed air is trigger air that controls activation of electrostatic sprayer <NUM>. The first portion of compressed air and the second portion of compressed air form the secondary airflow F2 ejected from electrostatic sprayer 24a.

Heater <NUM> is disposed on air line 54a between air source <NUM> and air inlet 48a. Heater <NUM> is configured to heat the first portion of air prior to the first portion or air being ejected from air cap <NUM>. In some examples, the compressed air can be heated to a temperature of about <NUM>-degrees C or higher. In other examples, the compressed air can be heated to a temperature of about <NUM>-degrees C or higher. The first portion of air, which breaks up and atomizes the charged fluid, is heated to prevent the charged fluid from freezing at air cap <NUM> and/or after ejection from electrostatic sprayer 24a. While heater <NUM> is described as disposed on air line 54a, it is understood that heater <NUM> can, in some examples, be integrated into electrostatic sprayer 24a and/or be configured to additionally and/or alternatively heat air line 54b.

<FIG> is a flowchart illustrating method <NUM> of spray chilling. In step <NUM>, a chilled primary airflow is generated and provided to a chilling tunnel, such as chilling tunnel <NUM> (<FIG> and <FIG>). A primary blower, such as primary blower <NUM> (<FIG> and <FIG>), chills the air and blows the air into the chilling tunnel. The primary blower can chill the primary airflow to any temperature suitable for chilling the foodstuffs being processed. In some examples, the primary blower is configured to chill the primary airflow to a temperature of about <NUM>-degrees C (about <NUM>-degrees F). In some examples, the primary blower is configured to chill the primary airflow to a temperature below about <NUM>-degrees C. As such, the primary blower can, in some examples, generate a primary airflow that is chilled to at or below the freezing point of water.

In step <NUM>, a foodstuff, such as foodstuff C (<FIG> and <FIG>), is traversed through the chilling tunnel. The foodstuff can be mounted on a conveyor, such as conveyor (<FIG> and <FIG>) that extends through the chilling tunnel. The conveyor carries the foodstuff through the chilling tunnel where the chilled primary airflow conducts heat from the foodstuff, thereby reducing the core temperature of the foodstuff and chilling the foodstuff.

In step <NUM>, a charged fluid spray is generated and sprayed onto the foodstuff. In some examples, the fluid is charged to about <NUM>-60kV. In some examples, the fluid is charged to <NUM>-50kV. The charged fluid is attracted to the nearest grounded object, which is the foodstuff suspended by the conveyor. The charged fluid wraps around and evenly coats the surface of the foodstuff. Charged fluid droplets having a charge of greater than about 10kV disintegrate into extremely small droplets that go into a process of accelerated evaporation. In some examples, the charged fluid droplets have an average diameter of about <NUM>-<NUM> micrometers. In some examples, the droplets have an average diameter of about <NUM> micrometers. The extremely small droplets deposit on the surface of the foodstuff and accelerate the cooling process, thereby reducing the weight lost from the foodstuff throughout the cooling process.

The electrostatic sprayer can eject a secondary airflow to generate the charged fluid spray. For example, a pneumatic line can extend to the electrostatic sprayer to provide compressed air to the electrostatic sprayer. The compressed air can be split into multiple feeds, such as atomizing air and fan air. The atomizing air breaks up the charged fluid stream and controls droplet size. The fan air controls the shape and width of the spray pattern. The compressed air can be heated prior to being ejected from electrostatic sprayer to avoid freezing of the spray droplets due to the chilled primary airflow. For example, a heater can be disposed on the pneumatic line providing the atomizing air to the electrostatic sprayer. In some examples, the compressed air can be heated to a temperature of about <NUM>-degrees C (about <NUM>-degrees F) or higher. In other examples, the compressed air can be heated to a temperature of about <NUM>-degrees C (about <NUM>-degrees F) or higher.

The secondary airflow carries the charged fluid spray into the chilling tunnel and towards the foodstuff. In some examples, secondary fans, such as secondary fans 26a, 26b (<FIG>), and air baffles, such as air baffles 28a, 28b (<FIG>), orient and guide the primary airflow along the spray axis of the electrostatic sprayer. Orienting and guiding the primary airflow parallel to the secondary airflow from the electrostatic sprayer protects the integrity of the charged fluid spray generated by the electrostatic sprayer. Protecting the integrity of the charged fluid spray ensures that the droplets are directed towards and/or parallel to the foodstuff.

Claim 1:
A method of spray chilling, the method comprising:
generating a chilled primary airflow and blowing the primary airflow into a chilling tunnel;
traversing, via a conveyor line, an electrically grounded foodstuff through the chilling tunnel;
generating a charged fluid spray;
applying the charged fluid spray to the foodstuff; and
orienting, via an air guiding baffle, the primary airflow along a first spray axis of a first electrostatic sprayer such that the primary airflow flows generally parallel to the first spray of charged fluid generated by the first electrostatic sprayer.