Appartus and methods of providing uniform surface freezing to food products

Abstract

A method and apparatus for cryogenic freezing of a first food product using a freezer (100), the freezer including a chamber (200). The method includes receiving the first food product on a conveyor through a first sidewall of the freezer when a first door (101) positioned on the first sidewall is in an open or in a partially open position; and circulating a cooling gas inside the chamber when the first door is in a partially closed position or in a closed position, wherein the cooling gas circulates inside the chamber flowing around the first food product.

Description

2281-15 (P23D019-US) APPARATUS AND METHODS OF PROVIDING UNIFORM SURFACE FREEZING TO FOOD PRODUCTS PRIORITY

[0001] This application claims priority under 35 U.S.C. §119 to Provisional Application No. 63 / 509,435, filed in the U.S. Patent and Trademark Office on June 21, 2023, the entire content of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION

[0002] The present disclosure relates generally to cryogenic freezers used to freeze food products. BACKGROUND OF THE INVENTION

[0003] Cryogenic freezers play a vital role in the food production industry by rapidly freezing food products. These freezers come in various types, including tunnel freezers, spiral freezers, continuous freezers, and cabinet freezers. A cryogen such as liquid nitrogen or carbon dioxide is injected into the cryogenic freezer to provide the cooling medium coming in contact with the food product and circulated inside the cryogenic freezer.

[0004] Continuous freezers may encompass tunnel freezers and spiral freezers as subsets within their design. These types of freezers, including tunnel freezers and spiral freezers, are characterized by accessible entry and exit points that facilitate the smooth movement of food products in and out of the freezing process. In the case of tunnel freezers, the food product is transported through the freezer via a conveyor belt, which can be positioned either horizontally or inclined at an angle. The temperature within the tunnel freezer usually ranges from -30° Fahrenheit (F) to -150° F (-34° Celsius (C) to -101° C), enabling the freezing process to be completed in typically no more than 30 minutes.

[0005] Spiral freezers operate similarly to tunnel freezers, but the conveyor belt follows a helical path inside the freezer. This configuration typically ensures more uniform freezing of the food product and provides potentially longer dwell times for the food product compared to tunnel freezers. Spiral freezers are particularly suitable for delicate or high-water content food products or higher production rates.

[0006] Other types of continuous freezers may employ double, triple, or multi-pass conveyor belts,2281-15 (P23D019-US) enabling better footprint utilization than tunnel freezers or spiral freezers for the same freezing need. These types of continuous freezers are commonly used for freezing large food products or items with a high volume. In contrast, cabinet freezers, a relatively small type of cryogenic freezer, do not have open entry and exit points. The food product is placed on a rack or shelf inside a cabinet freezer, a door is closed, and freezing takes place.

[0007] Crust freezing, which is essential for efficient food production, reduces the deformation of food items, allowing slicers to operate consistently, resulting in higher yield and increased productivity. Existing freezers face challenges when it comes to optimal crust freezing, require significant space, and struggle to seamlessly integrate with slicers for slicing operations.

[0008] General-use cryogenic freezers such as tunnel freezers, continuous freezers or cabinet freezers may be used to crust freeze food products. However, these freezers have several limitations. They require a large footprint, have a slow rate of heat transfer, and use a product handling scheme that is not optimized for crust freezing prior to slicing. This can lead to increased labor costs and increased cryogen usage. In addition, the airflow pattern (e.g., the direction of the flow of air or gas) of general-use freezers often leads to uneven crust freezing on the product surface. This can result in inconsistent slice quality and waste.

[0009] Specialized cryogenic freezers may be used to crust freeze food products, but these freezers typically have a large size footprint and are mechanically complex. The use of such specialized cryogenic freezers leads to higher capital costs and makes it more difficult to integrate the freezer with neighboring unit operations. As a result, these freezers have not been widely adopted commercially. Achieving consistent crust freezing over multiple slicing cycles is crucial to improve performance of a downstream slicer. Thus, a solution is needed to ensure uniform and reliable crust freezing for improved food preparation and slicing processes.

[0010] As described herein, a solution is provided that overcomes the limitations of conventional crust freezers by achieving a small size footprint, a fast rate of heat transfer, and an optimized product handling scheme for slicing operation. This results in lower labor costs, reduced amount of wasted cryogen, and a consistent quality of freezing. The solution disclosed herein is also relatively easy to integrate with neighboring unit operations, making it an attractive commercial option. SUMMARY OF THE INVENTION2281-15 (P23D019-US)

[0011] The present disclosure has been made to address the above-mentioned problems and disadvantages, and to provide at least the advantages described below.

[0012] The present application provides a new type of freezing apparatus and methods that overcome the aforementioned disadvantages. The freezer features in-line operation, automated lengthwise product transfer, uniform crust freezing, the ability to process a wide variety of product sizes and configurations, and a novel door design for optimal performance and convenience.

[0013] According to an aspect of the disclosure, a method for cryogenic freezing of a first food product using a freezer, the freezer including a chamber. The method includes receiving the first food product on a conveyor through a first sidewall of the freezer when a first door positioned on the first sidewall is in an open or in a partially open position; and circulating a cooling gas inside the chamber when the first door is in a partially closed position or in a closed position, wherein the cooling gas circulates inside the chamber flowing around the first food product.

[0014] According to another aspect of the disclosure, a cryogenic freezing apparatus including a chamber for cooling a first product is provided. The cryogenic freezing apparatus includes a first door positioned on a first sidewall of the chamber and configured to be in an open position, a partially closed position, or in a closed position; a conveyor configured to receive the first food product through the first sidewall when the first door is in a partially open position or in the open position; and a means for circulating a cooling gas inside the chamber when the first door is in a partially closed position or in the closed position, wherein the cooling gas circulates inside the chamber flowing around the first food product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following detailed description, when taken in conjunction with the accompanying drawings, in which:

[0016] FIG. 1A illustrates a front perspective view of a cryogenic freezer, according to an embodiment;

[0017] FIG. 1B illustrates a rear perspective view of a cryogenic freezer, according to an embodiment;

[0018] FIG. 2A illustrates an intended gas circulation path within the chamber of the freezer, according to an embodiment;2281-15 (P23D019-US)

[0019] FIG.2B illustrates a velocity map of an intended gas circulation path within the chamber of the freezer, according to an embodiment;

[0020] FIG.3 illustrates an adjustable feature of the plate included in the chamber of the freezer, according to an embodiment;

[0021] FIG.4 illustrates a plate capable of attaching to a space filler, according to an embodiment;

[0022] FIG. 5A illustrates a top perspective view of the conveyor with a bypass restrictor mechanism, according to an embodiment;

[0023] FIG. 5B illustrates a bottom perspective view of the conveyor with a bypass restrictor mechanism, according to an embodiment;

[0024] FIG.5C illustrates a velocity map of a gas circulation path within the chamber of the freezer with a bypass restrictor mechanism, according to an embodiment;

[0025] FIG. 5D illustrates a velocity map of a gas circulation path within the chamber of the freezer without a bypass restrictor mechanism, according to an embodiment;

[0026] FIG. 6 illustrates a freezer with a vertical door in the open position, according to an embodiment;

[0027] FIG.7 illustrates a front two-dimensional view of the door, according to an embodiment;

[0028] FIG. 8 illustrates a frontal view of the freezer showing a first opening, according to an embodiment; and

[0029] FIG.9 illustrates an operational sequence of the freezer, according to an embodiment. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It should be noted that the same elements will be designated by the same reference numerals although they are shown in different drawings. In the following description, specific details such as detailed configurations and components are merely provided to assist with the overall understanding of the embodiments of the present disclosure. Therefore, it should be apparent to those skilled in the art that various changes and modifications of the embodiments described herein may be made without departing from the scope of the present disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. The terms described below are terms defined in consideration of the functions in the present disclosure, and may be different according to users, intentions of the users,2281-15 (P23D019-US) or customs. Therefore, the definitions of the terms should be determined based on the contents throughout this specification.

[0031] The present disclosure may have various modifications and various embodiments, among which embodiments are described below in detail with reference to the accompanying drawings. However, it should be understood that the present disclosure is not limited to the embodiments, but includes all modifications, equivalents, and alternatives within the scope of the present disclosure.

[0032] Although the terms including an ordinal number such as first, second, etc. may be used for describing various elements, the structural elements are not restricted by the terms. The terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first structural element may be referred to as a second structural element. Similarly, the second structural element may also be referred to as the first structural element. As used herein, the term “and / or” includes any and all combinations of one or more associated items.

[0033] The terms used herein are merely used to describe various embodiments of the present disclosure but are not intended to limit the present disclosure. Singular forms are intended to include plural forms unless the context clearly indicates otherwise. In the present disclosure, it should be understood that the terms “include” or “have” indicate the existence of a feature, a number, a step, an operation, a structural element, parts, or a combination thereof, and do not exclude the existence or probability of the addition of one or more other features, numerals, steps, operations, structural elements, parts, or combinations thereof.

[0034] Unless defined differently, all terms used herein have the same meanings as those understood by a person skilled in the art to which the present disclosure belongs. Terms such as those defined in a generally used dictionary are to be interpreted to have the same meanings as the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.

[0035] FIG. 1A illustrates a front perspective view of a cryogenic freezer, according to an embodiment. FIG. 1B illustrates a rear perspective view of a cryogenic freezer, according to an embodiment.

[0036] FIGS.1A-1B illustrate a unique design of the freezer 100 with a front door 101 entry visible in the open position in FIG.1A and a back door 102 entry visible in the open position in FIG.1B.2281-15 (P23D019-US) The doors in this design of the freezer 100 provide a distinct approach for product entry and exit, eliminating the need for continuously open entrances and exits within the dedicated freezing space. As described herein, the terms “open” and “closed” are used to describe instances of each of the doors’ positioning, however each of the terms may be considered to encompass instances in which a door is “partially” open or “partially” closed. That is, because the present freezer device features a unique arrangement of doors and components which facilitate for semi-continuous or continuous entry of food products for freezing and exit of food products after freezing, situations may occur in which, for example, the front door is partially open when a food product enters the freezer, since the front door may only be required to open to create an opening in a sidewall having a cross- sectional area (or profile) large enough for the food product to pass and enter the freezer. Similarly, when exiting from the back door, the opening may only need to be large enough for the food product to pass. Thus, “open” may mean “partially open”. Also, in some situations, freezing may begin to occur while one or more of the doors are partially closed. Although embodiments of the present Application generally envision circulating gas when the doors on the freezer have been closed, other embodiments covered by this Application may include instances in which the doors have yet to be fully closed, or remain partially closed when, for example, freezing is set to begin prior to fully closing one or more of the doors. In other words, liquid nitrogen, cryogenic gas, or any other freezing agent can begin to be circulated (or injected) into the chamber while one or more of the doors are closing. Thus, “closed” may mean “partially closed”.

[0037] The freezer 100 employs one or more continuous conveyors to facilitate the movement of products (e.g., food items) in and out, subsequently ensuring their stationary or near-stationary positioning during the desired freezing cycle. The freezer 100 may be equipped with doors 101 and 102 that permit the ingress and egress of products on a conveyor. Products may enter the freezer on a conveyor through an opening of the front door 101. However, during the actual freezing process, these doors 101 and 102 close to prevent the entry of the warmer atmosphere surrounding the freezer through the entrance and exit sides, and to confine the cold atmosphere inside the freezer, thereby maintaining operational efficiency. At the conclusion of the freezing process, the back door 102 may open, allowing the transfer of chilled products out of the freezer 100 on a conveyor belt, and the introduction of products for the subsequent batch chilling cycle may enter through an opening of the front door 101. Furthermore, the incorporation of these specialized doors 101 and 102, along with strategically positioned fans, baffles, and conveyors in2281-15 (P23D019-US) this innovative freezer 100, facilitates the generation of a high-velocity cold gas flow parallel to a product. This gas flow is capable of enveloping the product uniformly, ensuring consistent chilling and crust freezing of the product within the enclosed freezer 100. Moreover, this unique freezer design allows for the product to begin to encounter the cold gas while either or both of the doors 101 or 102 are in the open position or closed position. Also, the freezer design enables for the product to begin to encounter the cold gas while the product is stationary (e.g., at a velocity of zero) or while the product is moving (e.g., at a velocity greater than zero). As used herein, the term “product” may be used interchangeably with the term “food product”. A “food product” may refer to one or more individual products, such as, for example, a prepared food product or a raw food product. Moreover, a “food product” may include an individual item of food (e.g., an item of food that is long in length and conducive for slicing) or multiple items of food positioned in a particular orientation that is conducive for freezing and / or crusting (e.g., in a row). In other words, a “food product” may include a plurality of rows of items of food with each row including multiple items of food. Additionally or alternatively, the “food product” may be determined by (or based on) a freezing area inside of the chamber. That is, a number of items of food positioned inside of a freezing area inside of the chamber may constitute a “food product”. As used herein, the term “velocity” may refer to the rate at which an object changes its position. “Velocity” may be a vector quantity, having both magnitude (speed) and direction components. Alternatively, “velocity” may be a scalar quantity, having only a magnitude (speed) component.

[0038] Crust freezing involves the initial freezing of an outer layer or surface of the product. During crust freezing, the temperature of the food product is lowered rapidly, forming a thin layer of ice and frozen product on its surface. This rapid freezing creates a protective barrier that helps retain the product’s moisture, texture, and overall quality. The crust serves as insulation for the inner part of the product, preventing excessive moisture loss and preserving its integrity. Particularly for a slicing operation, the crust serves as a structural enhancement to the food product. Food products, such deli meats, are often deformable upon impact with a blade during high-speed slicing operations. The deformation degrades the uniformity of the slices, which reduces the product yield and the overall profitability of the food processing operation. On the other hand, a food product with properly frozen crust is less deformable because of the less flexible outer crust. Therefore, a food product with a frozen crust is able to retain its shape during slicing and provide better slice yield and / or increased slicing speed, improving the overall profitability of the food2281-15 (P23D019-US) processing operation.

[0039] FIG. 2A illustrates an intended gas circulation path within the chamber of the freezer, according to an embodiment. The chamber may be positioned inside the freezer and may be bounded by nonporous material including but not limited to one or more internal walls, sidewalls, doors, roofs, floors or other substantially equivalent materials. Furthermore, when the doors are fully closed, then the chamber is enclosed (sealed). Conversely, when one or more doors are open, then the chamber is not enclosed (or not sealed). Various materials can be used to construct the chamber, depending on factors such as temperature requirements, insulation properties, compatibility with cryogenic fluids, and structural integrity. For example, the chamber may include one or more of stainless steel, aluminum, insulated panels, fiberglass reinforced plastic, polycarbonate, acrylic, and / or other specialty materials.

[0040] Referring to FIG. 2A, a gas circulation path is depicted by arrows shown in the counterclockwise direction within the chamber 200 of the freezer, extending along the length of the conveyor 201. The conveyor 201 may include any type of conveyor belt capable of transporting the product 203. For example, the conveyor 201 may be a mesh-less metal belt, where the mesh is removed from a wire mesh belt. Additionally or alternatively, the conveyor 201 may also include a wire mesh belt, a plastic modular belt, a solid plastic belt, a metal belt, a fabric belt, and / or a hybrid belt. A centrifugal fan 202 located at one end of the chamber 200 generates the gas flow, which then reverses direction on the opposite side of the chamber 200. The gas flow runs parallel to both the product 203 and the conveyor 201 before returning to the centrifugal fan 202. The gas circulation path provides an evenly distributed flow throughout the length of the product 203, thereby providing uniform heat transfer across exposed surfaces of the product 203. Throughout this process, the freezer’s front door 204 (corresponding to the front door 101) and back door 205 (corresponding to the back door 102) are closed, sealing the chamber 200, creating an enclosed gas path within the freezer.

[0041] Included in the chamber 200 of the freezer is a plate 206 (e.g., a plenum plate), solid or nonporous in construction, effectively segregating an upper region 207 and a lower region 208 of the chamber 200 to enable the circular flow of the gas. Although the upper region 207 and the lower region 208 are separated by the plate 206, the two regions 207 and 208 are not completely sealed off from each other. The length of the plate 206 is less than the length of each of the regions, allowing for each end of each of the regions 207 and 208 to come into contact with each other,2281-15 (P23D019-US) which enables the gas to circulate from one region to the next. The gas may be a cryogen gas, such as carbon dioxide, nitrogen, or their combinations. As the gas exits the centrifugal fan 202 and enters the upper region 207, the plenum plate 206 prevents the gas exiting the centrifugal fan 202 from directly contacting the food products, thereby establishing a circulation path within the chamber 200. After flowing through the upper region 207, the cryogen gas airflow is directed along the inner surface of the sidewall to reach and interact with the product 203 in the lower region 208. The conveyor 201 ensures that the cryogen airflow comes into contact with all surfaces of the product 203. The gas flow spans the entire length of the conveyor 201 within the lower region 208 of the chamber 200. The gas flow is then redirected back to the centrifugal fan 202 along the lower region 208 of the chamber 200, and is recycled for subsequent chilling. The positioning of the plate 206 within the chamber allows the proximal end to be located near the centrifugal fan 202, while the distal end extends towards the sidewall that includes the front door 204.

[0042] Both a bypass restrictor (shown below with reference to 501a of FIGS. 5A-5B) and a bottom support 209 are used to help form the gas flow path in the lower region 208. The bottom support 209 is a horizontal sheet located below the conveyor 201. If the bottom support 209 wasn’t present, then the gas would pass through and around the product with less velocity, and thus cooling and freezing would be less uniform. Accordingly, the bypass restrictor and the bottom support 209 are necessary for the chamber 200 to uniformly freeze the product with the intended gas flow path.

[0043] The conveyor 201 contacts one or more gliding strips 210, which are installed on top of the bottom support 209. Therefore, the conveyor 201 may have a 25-40 millimeter vertical distance from the bottom support 209, which exposes the product 203 to gas flow beneath the product, through a space between the conveyor 201 and the bottom support 209. One or more belt rods 211 may be used to move the conveyor 201 in the forward or backward direction, thus positioning the product 203 to a preferred area for freezing. The one or more belt rods may move between the space below the conveyor 201 and above the one or more gliding strips 210.

[0044] The front door 204 of the freezer is positioned along the inner and / or outer wall of one side of the freezer (e.g., a sidewall), and the back door 205 is positioned along an inner and / or outer wall of an opposite side of the freezer. This orientation of doors 204 and 205 allows for the product 203 to enter the freezer through an opening of the front door 204, become frozen, and exit the freezer through an opening of the back door 205 without changing directions. Therefore, the frozen2281-15 (P23D019-US) food products can be sliced without having to be reoriented after being frozen. Additionally, a food product that exits the freezer may be considered to be in a different state than a food product that enters the freezer. Food products exiting the freezer may be frozen, chilled, or crusted, because they have undergone exposure to cryogenic gas (or another similar cooling agent) inside the freezer. Food products entering the freezer have yet to have been exposed to the cryogenic gas (or another similar cooling agent) inside of the freezer.

[0045] The terms “front door” and “back door” are merely used to describe a first door and a second door, and are not intended to be limiting; meaning that the “front door” may be a door in which the product 203 exits the freezer, and the “back door” may be a door in which the product 203 enters the freezer. Moreover, depending on the orientation of the freezer, the “front door” may be located at the back of the freezer, and the “back door” may be located at the front of the freezer.

[0046] Furthermore, although FIG. 2A illustrates the centrifugal fan 202 to be positioned at one end of the chamber 200, the centrifugal fan 202 may also be located at other areas inside of the chamber 200. For instance, the centrifugal fan 202 may be located in the middle of the upper region 207, and still be capable of forming the gas circulation path necessary for uniform freezing.

[0047] In another embodiment, the centrifugal fan 202 may be located in the middle of the upper region 207, and generate a gas flow in more than one direction in the upper region 207. For example, when the centrifugal fan 202 is located in the middle of the upper region 207, the gas may flow in a first direction in the upper region 207 away from the centrifugal fan 202 and towards the sidewall having the front door 204, and in a second direction in the upper region 207 away from the centrifugal fan 202 and towards the sidewall having the second door 205, wherein the first direction is opposite to the second direction. Furthermore, the gas may then change directions along each of the sidewalls and enter the lower region 208 from each end of the chamber 200. The gas that was flowing in the first direction in the upper region 207 may now be flowing in the second direction in the lower region 208, and the gas that was flowing the second direction in the upper region 207 may now be flowing in the first direction in the lower region 208. The gas may approach and enter a fan inlet in the middle of the lower region 208 and pass through the plate 206, to return to the centrifugal fan 202 for continued circulation.

[0048] The design of centrifugal fan 202 may include a housing or casing, an impeller with curved blades, and an inlet and outlet for gas. The impeller, which is mounted on a rotating shaft, may draw in gas axially and then direct it radially outward. As the impeller spins, the centrifugal force2281-15 (P23D019-US) may cause the gas to move away from the center and accelerate in a curved path due to the shape of the blades. This may result in the generation of a high-pressure airflow perpendicular to the fan’s axis. Moreover, although the term “centrifugal fan” is used to denote reference numeral 202, the present Application encompasses embodiments in which reference numeral 202 may be a gas moving device or a means for circulating gas. Thus, as used herein, the term “fan” or “centrifugal fan” may be interchangeable with gas moving device or a means for circulating gas. The gas moving device may encompass various devices capable of moving gas, such as, but not limited to, a fan, blower, compressor, pump, or substantially equivalent devices. These devices can be designed to move gas in different manners, including axial, radial, or mixed flow. For example, a blower may move gas using a high-speed rotor to increase pressure and velocity, while a compressor may increase the pressure of the gas by reducing its volume. A pump, although typically used for liquids, can be adapted for gases in certain configurations to create a pressure differential and induce flow. Additionally, the means for circulating gas may refer to any mechanism or device that facilitates the movement and circulation of gas within a system (and in particular, inside the chamber), including ducts, vents, valves, other components that direct and control gas flow, as well as any of the aforementioned possible gas moving devices. Furthermore, the gas moving device and / or means for circulating gas may be positioned inside the freezer (as shown in FIG.2A) or outside the freezer.

[0049] FIG.2B illustrates a velocity map of the intended gas circulation path within the chamber of the freezer, according to an embodiment.

[0050] Referring to FIG. 2B, a computational fluid dynamic velocity map is provided in which red equates to a high velocity of gas and blue equates to a low velocity of gas. The gas circulates around the plate 206. Gas exits the centrifugal fan 202 at a relatively slow velocity and travels toward the front door 204 in the upper region 207 above the plate 206. Then, the gas changes direction along the sidewall with the front door 204, and enters the lower region 208 including the product 203. Ideally, the product 203 forms a narrow passageway in the lower region 208 for the gas to pass through, causing the gas to pass at a high velocity, thereby uniformly freezing the product 203 and / or its crust. As the gas passes through the lower region 208, it gathers heat from the product 203 and changes directions along the sidewall with the back door 205, and returns to the centrifugal fan 202.

[0051] According to an embodiment, the gas flow can be adjusted in terms of height and cross-2281-15 (P23D019-US) sectional width to facilitate fluid flow. Additionally, space-fillers can be employed to create channels of various lengths and widths suitable for accommodating products with varying dimensions. In order to achieve a uniform crust formation both around and along the product, cold gas should pass through narrow channels at a high velocity, enabling efficient heat transfer. To establish narrow channels, a rectangular cross-section inside the freezer may be obstructed. If the channel is not sufficiently narrow, leading to a larger cross-sectional area, a significant portion of the gas flow may bypass the product and instead flow through the open cross-sectional area. Considering the freezer’s intended usage for products with diverse widths, heights, and quantities per batch, one or more parameters related to the gas flow within the product zone should be adjustable.

[0052] FIG.3 illustrates an adjustable feature of the plate included in the chamber of the freezer, according to an embodiment.

[0053] Referring to FIG.3, within the chamber 300 (corresponding to the chamber 200), a height adjustment mechanism 301 for the gas flow is illustrated. To accommodate products with different heights while forming a preferred narrow channel, the position of plate 302 (corresponding to the plate 206) is vertically adjustable, as shown in (A) and (B) of FIG.3. That is, the position of plate 302 may be raised towards the upper region 303 (corresponding to the upper region 207) of the freezer ((A) of FIG.3) or lowered towards the lower region 304 (corresponding to the lower region 208) of the freezer ((B) of FIG. 3). More specifically, as the plate 302 is raised, a ratio of the distance from the ceiling of the freezer to the plate 302 is decreased relative to the distance from the plate 302 to the top of the conveyor belt. In other words, as the plate 302 is raised, the volume of the upper region is decreased relative to the volume of the lower region. The plate 302 is adjusted based on the product’s height and, ideally, the plate is positioned slightly above the product, leaving only a small amount of space between the product and the plate 302, so that the gas may flow evenly along the surface of the product.

[0054] For example, the plate 302 may be vertically adjustable between a predetermined distance, such as 40 millimeters (mm) to 250 mm, from the conveyor 305 (corresponding to the conveyor 201) without requiring external tools. Accordingly, the freezer provides improved versatility towards physical variations of the product by incorporating a vertical adjustment mechanism.

[0055] As discussed above, the design of a channel formed in the lower region 304 may be adjusted to enhance the gas flow velocity generated by fan blades that may have a smaller diameter.2281-15 (P23D019-US) Additionally, a portion of the gas flow path can be further restricted (e.g., narrowed) using space- filling mechanisms. It is noted that not all food producers utilize the entire available width of the volume of the freezer; thus, a method to reduce the cross-sectional area used during freezing may be particularly useful.

[0056] To reduce the cross-sectional area of the channel formed in the lower region 304, the plate may be capable of temporarily attaching to one or more space fillers. A space filler may be any solid object capable of restricting a cross-sectional area of the channel (e.g., tubes, cylinders, solid panels, boards, insulated curtains, removable inserts, foam blocks, and / or sealed partitions).

[0057] FIG.4 illustrates a plate capable of attaching a space filler, according to an embodiment.

[0058] Referring to FIG.4, a plate 400 (corresponding to the plate 206 and the plate 302) is located above one or more space fillers 401. The plate 400 includes one or more engagement mechanisms 402 provided thereon. The engagement mechanisms 402 may be a “J” hook or any other type of latching device (e.g., spring clips, latches or locking mechanisms, screw fasteners, snap-fit connectors, and / or magnetic attachments) capable of engaging with one or more attaching mechanisms 403 positioned on the one or more space fillers 401 so that the one or more space fillers 401 are physically moved and positioned to reduce a cross sectional area of the channel. The attaching mechanism 403 may be an “O” ring or any other type of mechanism capable of attaching to the engagement mechanism 402 (e.g., spring clips, latches or locking mechanisms, crew fasteners, snap-fit connectors, and / or magnetic attachments). When connected, the attaching mechanism 403 and the engagement mechanism 402 may be configured to remain securely attached to each other while gas is passed through the channel. The direction in which the engagement mechanism 402 engages with and attaches to the attaching mechanism 403 may be in a direction facing the flow of the gas, thereby minimizing the possibility of detachment.

[0059] By securely attaching the space filler 401 to the plate 400, the space filler 401 can remain in position even during belt operation. As discussed above, the space filler 401 may further narrow a cross sectional area of the channel to enhance precise freezing. Consequently, a food producer may be relieved from the need to circulate one or more space fillers 401 with every batch, streamlining the overall process.

[0060] Accordingly, as described above, two independent mechanisms for adjusting the cross sectional area of the channel are disclosed herein. The first mechanism is adjusting the vertical height of the plate, and the second mechanism is introducing a space filler to occupy an area inside2281-15 (P23D019-US) of the channel.

[0061] Referring again to FIG.3, a bypass restrictor mechanism 306 is illustrated at a front area of the conveyor 305. The bypass restrictor mechanism 306 prevents the cold gas from entering the space below the conveyor 305. If the cold gas were to enter the space below the conveyor 305, then less gas would pass through the narrow passageway in the lower region 304, and uniform freezing would be impeded.

[0062] FIG. 5A illustrates a top perspective view of the conveyor with a bypass restrictor mechanism, according to an embodiment. FIG. 5B illustrates a bottom perspective view of the conveyor with a bypass restrictor mechanism, according to an embodiment.

[0063] Referring to FIGS. 5A-5B, a conveyor 500 (corresponding to the conveyor 201 and the conveyor 305) is illustrated with a first bypass restrictor 501a (corresponding to the bypass restrictor mechanism 306). The first bypass restrictor 501a may be any object (e.g., a metal plate) used to restrict or control the flow of the cooling gas in a specific area or path within the chamber. For example, the first bypass restrictor 501a may form a wall below a front side of the conveyor 500 to restrict gas from entering below the conveyor 500. The first bypass restrictor 501a may include multiple portions (e.g., a vertical portion and / or a horizontal portion), and may form a seal from the bottom of the chamber to the bottom of the conveyor 500.

[0064] The purpose of the first bypass restrictor 501a may be to prevent or limit the entry of the cooling gas into an area beneath the bottom support 209. By restricting the flow of the cooling gas in that specific region, the bypass restrictor may help ensure that the product 203 on the conveyor 500 is exposed to the desired cooling conditions.

[0065] The first bypass restrictor 501a can take different forms depending on the design and configuration of the cryogenic freezer. It may involve the use of physical barriers, adjustable valves, or other mechanisms that regulate the flow of the cooling gas. The specific design and placement of the bypass restrictor may be determined based on the freezer’s requirements, the type of product being frozen, and the desired freezing process parameters.

[0066] In order to achieve the desired high-velocity flow of gas along the intended pathway during the freezing process, both openings of the freezer should be blocked. Considering the expected disparity in pressure between the interior of the freezer and the atmospheric pressure, these two ends of the freezer should be effectively sealed to minimize any air infiltration and gas exfiltration. Furthermore, the sealing mechanism employed should facilitate the repeated transfer of food2281-15 (P23D019-US) products through numerous cycles of seal openings and closings. In addition, the sealing mechanism may enable efficient sanitation procedures to be carried out effectively.

[0067] FIG.5C illustrates a velocity map of a gas circulation path within the chamber of the freezer with a bypass restrictor mechanism, according to an embodiment. FIG. 5D illustrates a velocity map of a gas circulation path within the chamber of the freezer without a bypass restrictor mechanism, according to an embodiment.

[0068] Referring to FIG. 5C, a computational fluid dynamic velocity map is provided in which red equates to a high velocity of gas and blue equates to a low velocity of gas. In FIG. 5C, the bypass restrictor mechanism includes two vertical sections, a first bypass restrictor 501a and a second bypass restrictor 501b. In various embodiments, the bypass restrictor mechanism may include more or less vertical sections. For example, the bypass restrictor mechanism may only include the first bypass restrictor 501a and not the second bypass restrictor 501b. On the other hand, the bypass restrictor mechanism may only include the second bypass restrictor 501b and not the first bypass restrictor 501a. In addition, the bypass restrictor mechanism may include other portions having different orientations. The bypass restrictor mechanism may include any object used to restrict or control the flow of the cooling gas in a specific area or path within the chamber.

[0069] The first bypass restrictor 501a of the bypass restrictor mechanism is positioned below the channel 502 (comprising the lower region) and towards the front of the chamber 503 (corresponding to the chamber 200 and the chamber 300). The second bypass restrictor 501b of the bypass restrictor mechanism is positioned below the channel 502 and towards the back of the chamber 503. The conveyor is positioned on the bottom of the channel 502, and the product is positioned inside of the channel 502 for freezing. The channel 502 is the area of the chamber 503 in which freezing of the product occurs. When the bypass restrictor mechanism is operating properly, the gas flow is diverted into the channel 502, and a surface of the product may be uniformly frozen.

[0070] In FIG.5D, the bypass restrictor mechanism including the first bypass restrictor 501a and the second bypass restrictor 501b are removed. Other structural features of FIG.5D are similar to FIG.5C.

[0071] Referring to FIG. 5D, a computational fluid dynamic velocity map is provided in which red equates to a high velocity of gas and blue equates to a low velocity of gas. In FIG.5D, with the bypass restrictor mechanism being absent, gas flow “leaks” below the channel 502 and around2281-15 (P23D019-US) the chamber 503, thereby not entering the channel 502 with as much velocity and pressure as compared to when the bypass restrictor mechanism is present (e.g., FIG. 5C). Thus, without the bypass restrictor mechanism, less gas enters the channel 502 and the temperature and / or velocity in the channel 502 isn’t uniform, leading to an inconsistent and poor quality of freezing of the product.

[0072] Many different variations of doors providing the sealing mechanism may be incorporated into embodiments of the present disclosure to achieve the desired freezing results. For example, vertically moving sealing doors may be used that effectively seal the two ends of the tunnel freezer. These vertical sealing doors can be implemented as sliding polymer plates.

[0073] FIG. 6 illustrates a freezer with a vertical door in the open position, according to an embodiment.

[0074] Referring to FIG. 6, a freezer 600 is provided. The freezer 600 features a door 601. Although the door 601 shown in FIG.6 technically corresponds to a “front” door (corresponding to 101 and 204), the door 601 may also be a “back” door (corresponding to 102 and 205), as the intent of the illustration is to show the manner in which the vertical sliding ability of the door 601 functions while it is in the open position.

[0075] As seen in FIG.6, an actuator 602 (e.g., a piston) is attached to a section of the door 601 and pulls the door 601 upwards to reveal an opening into the freezer 600. The actuator 602 is mounted at an angle and may push (or release) the door 601 to close the door 601 and cover the opening into the freezer 600. An external pneumatic piston may supply the actuation force for opening and closing the door 601. Additionally, the piston may be mounted at an angle so that a horizontal force is applied to the door, which helps seal the door in the closed position by pushing the door toward the freezer body. Furthermore, the edges of the door may be positioned inside of ridges, a track, along bearings, or other similar techniques in order to ensure that the door is raised (opened) or lowered (closed) in a vertical direction.

[0076] Sensors may be used to determine whether or not the door 601 is in an open or closed position. That is, sensors embedded in the door 601, the actuator 602 and / or the sidewall of the freezer 600 may detect whether the door 601 is in the open position or the closed position.

[0077] Although the door 601 is shown on the exterior of the freezer 600, the door 601 may also be included on the interior of the freezer 600 and operate similarly. In addition, the door 601 may be comprised of two doors, one on the exterior of the freezer 600, and another on the interior of2281-15 (P23D019-US) the freezer 600. In addition, other types of doors can be used, such as horizontally sliding doors, hinged doors, roll-up doors, vacuum insulated doors, or airlock doors.

[0078] Additionally, an injected coolant (or cooling gas) may be removed from the chamber at different rates according to whether the door is in the open or closed position. This can be accomplished, for example, by a pressure differential between the inside of the freezer and outside environment (for example, a pressure outside of the freezer may be less than a pressure inside of the freezer). This can also be accomplished by using an exhaust fan driven by variable speed motor (not shown in the figures), which may be internal to the freezer or external to the freezer. For example, the cooling gas may be removed from the chamber at a first rate substantially proportional to an amount of cooling gas injected when the cooling gas circulates when the first door is in the closed position. Also, the cooling gas may be removed at a second rate (e.g., less than the first rate) when the first door is in the open position.

[0079] FIG.7 illustrates a two-dimensional front view of the door, according to an embodiment.

[0080] Referring to FIG. 7, a door 700 is illustrated and may correspond to the front door (corresponding to the front door 101, the front door 204, and the front door 601) and / or the back door (corresponding to the back door 102, the back door 205). The door 700 includes embedded magnets 701 along a perimeter of the door 700 to enable the door 700 to self-orient and seal an opening by interacting with ferromagnetic material positioned beneath the wall of the freezer. The front door and the back door may be positioned on the exterior or interior of the freezer body, or both. In other words, two front doors (one interior front door and one exterior front door) and / or two back doors (one interior back door and one exterior back door) may be used. Additionally, heating may be applied to the perimeter of the door or the contact point between the door and freezer to enhance sealing capabilities.

[0081] FIG. 8 illustrates a frontal view of the freezer showing a first opening, according to an embodiment.

[0082] Referring to FIG.8, an opening 800 is provided on a front side of the freezer. The opening may be closed by covering it with a door. A product may enter (or exit) the freezer through the opening. A perimeter 801 of the opening may include a means of pulling the door towards the freezer by magnetic force to establish a seal. For example, a carbon steel inlay may be provided to magnetically attract the magnets embedded into the perimeter of the door (as explained, with reference to FIG.7).2281-15 (P23D019-US)

[0083] Accordingly, the door, opening, and sealing mechanisms provide a reliable seal over multiple cycles, and also allow for automated operation. Conventionally, doors may be positioned on lateral sides of cryogenic tunnel freezers, serving primarily for sanitation purposes by granting access to the freezer’s internal components and the conveyor belt during cleaning and sanitation procedures. In contrast, the present application provides for installing doors at one or both ends of the tunnel freezer, perpendicular to the lateral side, and utilizing the one or more doors to regulate airflow during the freezer’s operational phase, not solely during cleaning.

[0084] Conventional doors for cryogenic freezing apparatuses may not be designed to undergo more than 10 open-seal cycles per hour due to their low usage. Thus, conventional doors may use flexible materials for sealing the door to an opening, like spring steel or silicon, which can be pressed against the freezer with mechanical or pneumatic forces to achieve a seal. Moreover, automatic actuation of the doors is unnecessary in typical cases. However, according to one or more embodiments, the doors may undergo up to 60 open-seal cycles per hour, necessitating a robust sealing mechanism capable of maintaining effectiveness under various conditions. Thus, the solution of magnets embedded into the polymer door, as disclosed herein, provides a mechanism that seamlessly allows the doors to be opened and closed at a much higher rate and for a longer duration than conventional technologies.

[0085] In addition, a challenge encountered during the freezing process of a sizable food product is the diminished heat transfer experienced on its lower surface. This limitation arises from the direct contact between the bottom surface of the food item and the supporting or conveying surface, such as a tray or belt, which restricts convective heat transfer. Consequently, due to this non- uniform heat transfer, the food product may require an extended dwell time to ensure that crust freezing occurs on all surfaces, resulting in time lost, and excessive freezing beyond what is actually required.

[0086] To address this challenge, the present disclosure incorporates a novel conveying mechanism that offers several advantages to achieve uniform freezing of the product. First, the conveying mechanism may include a sufficient open area underneath the product, ensuring that the bottom surface of the product is extensively exposed to a high-speed gas flow. This configuration is particularly advantageous as it enhances heat transfer and accelerates the freezing process. Additionally, an opening of the bottom support is designed to be greater than or equal to a predetermined height or width, allowing for a substantial portion of the product surface to be in2281-15 (P23D019-US) direct contact with the gas flow. This increased contact area facilitates efficient heat exchange and promotes rapid and uniform freezing of the entire surface area of the product. Furthermore, a strategically positioned plate beneath the bottom surface serves to guide the gas flow, effectively creating a parallel pathway under the product. This design element further enhances the uniformity of freezing along the length of the product, preventing uneven freezing and ensuring consistent quality throughout. Thus, the conveying mechanism optimizes heat transfer, maximizes exposure of the product’s bottom surface to high-speed gas flow, and facilitates uniform freezing, resulting in improved efficiency and product quality.

[0087] In addition to ensuring uniform freezing, the utilization of a sufficient open area in the conveying mechanism offers an additional advantage in terms of sanitation. This is particularly beneficial for ready-to-eat products like pre-sliced ham and cooked poultry, where no additional cooking step is required before consumption. In such cases, it is crucial to minimize the presence of pathogens and foreign materials on the product’s surface. By minimizing the contact surface area, the freezer design, disclosed herein, enhances cleanability and reduces the risk of cross- contamination. This feature contributes to maintaining the product’s hygienic standards and further ensures the safety and quality of the ready-to-eat food items.

[0088] In addition, while a continuous freezer enables an in-line process, it often introduces larger inconsistencies, particularly when production halts due to an error. During such instances, a continuous freezer experiences significant loss of cold gas, resulting in product warming. In contrast, when production is halted, the freezer disclosed herein may retain the product within its confines, keeping the doors closed. This ensures more efficient utilization of cryogen and improves the ability of the freezer to obtain the desired crust freezing of the product.

[0089] FIG.9 illustrates an operational sequence of the freezer, according to an embodiment.

[0090] Referring to FIG. 9, three time intervals are shown. The duration of each of the time intervals may be the same or may be different. The time intervals occur in succession. That is, the first time interval occurs prior to the second time interval, which occurs prior to the third time interval.

[0091] During the first time interval, the freezer fan stops, thereby reducing the rate of recirculation of gas velocity (e.g., cryogen). At the beginning of the first time interval, one or more front doors (e.g., freezer doors) may be opened. After the freezer doors are opened, a product may be moved into the freezer at a first velocity. For example, the product may be moved into the2281-15 (P23D019-US) freezer on a movable conveyor belt.

[0092] During the second time interval, the freezer fan operates, thereby increasing cryogen flow. At the beginning of the second time interval, the freezer doors are closed, and the product stops moving or the product may move at a second velocity during the second time interval that is less than the first velocity. The product may remain stationary or move at the second velocity for a predetermined amount of time or until a desired state of freezing is achieved.

[0093] During the third time interval, the freezer fan stops, thereby reducing the cryogen flow. At the beginning of the third time interval, one or more back doors (e.g., discharge doors) open. After the discharge doors are opened, the product may be moved out of the freezer at a third velocity. The first velocity may be more than, less than, or equal to the third velocity. The second velocity may be less than the first velocity and / or the third velocity. For example, the second velocity may be zero and the first and / or third velocity may be greater than zero. On the other hand, the second velocity may be as low as 1 foot per minute (fpm) (0.3 meters per minute) and the first and / or third velocity may be greater than 1 fpm (0.3 meters per minute). The third time interval may partially or entirely overlap with the first time interval, allowing the product to be transferred in and out of the freezer simultaneously.

[0094] Accordingly, when the product is being transferred in and / or out of the freezer (e.g., during the first time interval and / or third time interval, respectively), the conveyor may move faster (than during the second time interval) to match an upstream and / or downstream belt velocity for receiving and / or exiting the product from / to an upstream or downstream piece of food processing equipment (e.g., a slicer). Additionally, the fast movement of the conveyor may advantageously minimize a time in which the front door and / or the back door is open. Furthermore, during the second time interval, when the gas is circulating to freeze the product, the conveyor may substantially slow down or stop.

[0095] The discharge doors may be the same as or may be different from the freezer doors opened during the first time interval. That is, the freezer may be designed so that the product enters through an opening on one end of the freezer and discharges through an opening on an opposite end of the freezer. On the other hand, the freezer may also be designed such that the product enters and discharges through an opening of the freezer on the same end.

[0096] Accordingly, the conveyor varies the velocity at which the product moves during the first, second, and third time intervals, and the freezer is configured to function intermittently in a semi-2281-15 (P23D019-US) batch manner. In essence, the freezer’s fan and cryogen injection are diminished or halted when the product is in motion during the first and third time intervals. Conversely, when the product is positioned and comes to a stop (or moves slowly at the second velocity) within the freezer, the fan and cryogen injection resume their operation at a predetermined duty cycle. Some aspects of this operational scheme bear resemblance to that of a cabinet freezer, with the distinction that product transfer occurs automatically, without the need for any product receptacles like racks or trays.

[0097] Although many benefits of the disclosed freezer design and method of freezing have been described herein, some of the benefits of the freezer design and method of freezing may be that the freezer enables in-line operation by using a high rate of heat transfer; allows for a product to automatically be transferred in a lengthwise direction (short edge leading) from product entrance to the exit; allows for gas flow to occur parallel to the product’s length, including along the bottom of the product; can account for a wide variety of different sized products; and features a novel door design.

[0098] Regarding enabling in-line operation by using a high rate of heat transfer, the freezer is capable of allowing for fast heat transfer, enabling the freezer to operate in-line with other processing equipment. This results in a smaller footprint and greater flexibility in choosing where to place the freezer. It also allows food processors to optimize the crust for different products, which can be cumbersome, with a central freezer serving multiple slicers.

[0099] Regarding allowing for a product to automatically be transferred in the lengthwise direction, unlike existing methods that require manual transfer or changing the product’s flow direction (e.g., changing the direction of the conveyor), the freezer is capable of transferring the product in a lengthwise direction. Thus, the product may be transferred to a slicer immediately after freezing in a continuous manner and flow. This natural feeding into the slicer eliminates the need for direction changes or manual transfers between crust freezing and slicing. The freezer’s small footprint and signal-exchange capability minimize manual intervention.

[0100] Regarding allowing for gas flow to occur parallel to the product’s length, including along the bottom of the product, the freezer is capable of enabling uniform gas flow, allowing the crust to freeze evenly around the entire product’s perimeter. On the other hand, if the gas flow were perpendicular to the product’s length, preferential crust freezing may occur on one side. Additionally, parallel processing of multiple product pieces may ensure consistent crust formation.

[0101] Regarding accounting for a wide variety of different sized products, the freezer is capable2281-15 (P23D019-US) of accommodating products of various shapes, widths, and heights for crust freezing through a simple product transfer mechanism. Unlike other designs limited to specific product types, this freezer may be capable of handling a wide range of products.

[0102] Regarding the novel door design, although many different types of doors may be used in accordance with the freezer, the doors are an important feature for the freezer’s operation, establishing the desired gas flow path. This disclosure introduces a novel door design utilizing magnetic seals. This design allows the doors to seal against static pressure while facilitating repeated actuation. The interaction between embedded magnets and inlaid ferromagnetic material ensures proper sealing and enables easy detachment for cleaning and sanitation purposes. This design outperforms other door designs in terms of functionality, sanitation, and durability.

[0103] Although certain embodiments of the present disclosure have been described in the detailed description of the present disclosure, the present disclosure may be modified in various forms without departing from the scope of the present disclosure. Thus, the scope of the present disclosure shall not be determined merely based on the described embodiments, but rather determined based on the accompanying claims and equivalents thereto.

Claims

2281-15 (P23D019-US) WHAT IS CLAIMED IS:

1. A method for cryogenic freezing of a first food product using a freezer, the freezer including a chamber, the method comprising: receiving the first food product on a conveyor through a first sidewall of the freezer when a first door positioned on the first sidewall is in an open or in a partially open position; and circulating a cooling gas inside the chamber when the first door is in a partially closed position or in a closed position, wherein the cooling gas circulates inside the chamber flowing around the first food product.

2. The method for cryogenic freezing of Claim 1, further comprising: exiting the first food product from the chamber on the conveyor through a second sidewall of the chamber when a second door positioned on the second sidewall is in an open or in a partially open position, wherein the second sidewall is located at an opposite end of the chamber from the first sidewall.

3. The method for cryogenic freezing of Claim 1, further comprising: receiving a second food product on the conveyor through the first sidewall when the first door is in a partially open or in an open position as the first food product is exiting the chamber through the second door or after the first food product has exited the chamber through the second door.

4. The method for cryogenic freezing of Claim 1, further comprising: circulating the cooling gas inside the chamber around the first food product when the first door is in a partially closed or in a closed position and a second door positioned on a second sidewall located at an opposite end of the chamber from the first sidewall is in a partially closed or in a closed position.2281-15 (P23D019-US) 5. The method for cryogenic freezing of Claim 1, wherein the freezer includes a plate in the chamber separating the chamber into a first region and a second region, and wherein the cooling gas circulates inside of the chamber in a first direction through the first region, and in a second direction through the second region opposite to the first direction.

6. The method for cryogenic freezing of Claim 5, further comprising: raising the plate in the chamber in a direction away from the conveyor or lowering the plate in a direction towards the conveyor.

7. The method for cryogenic freezing of Claim 1, further comprising: pulling the first door towards a ferromagnetic material positioned beneath the first sidewall using a magnetic force to close the first door and seal the first sidewall.

8. The method for cryogenic freezing of Claim 1, further comprising: opening the first door by raising the first door in a first vertical direction or closing the first door by lowering the first door in a second vertical direction, wherein the first vertical direction is an opposite direction to the second vertical direction.

9. The method for cryogenic freezing of Claim 1, wherein circulating the cooling gas inside the chamber when the first door is in a partially closed or in a closed position comprises causing a portion of the cooling gas to flow into an area beneath the conveyor and above a bottom support positioned below the conveyor, to circulate the gas around a bottom outer surface of the first food product.

10. The method for cryogenic freezing of Claim 1, further comprising: attaching one or more engagement mechanisms arranged on a plate in the chamber to one or more attachment mechanisms arranged on a space filler, thereby reducing a cross sectional area in a region below the plate.2281-15 (P23D019-US) 11. The method for cryogenic freezing of Claim 1, wherein a velocity of the first food product is a first velocity when the first food product is received on the conveyor when the first door is in a partially open or in an open position, wherein the velocity of the first food product is a second velocity when the cooling gas circulates inside the chamber when the first door is in a partially closed or in a closed position, and wherein the first velocity is greater than the second velocity.

12. The method for cryogenic freezing of Claim 1, further comprising: removing the cooling gas from the chamber at a first rate when the first door is in a partially closed or in a closed position, and removing the cooling gas from the chamber at a second rate that is less than the first rate when the first door is in a partially open or in an open position.

13. The method for cryogenic freezing of Claim 1, wherein the cooling gas is circulated inside the chamber using at least one gas moving device.

14. A cryogenic freezing apparatus comprising a chamber for cooling a first food product, the apparatus comprising: a first door positioned on a first sidewall of the chamber and configured to be in a partially open position, an open position, a partially closed position, or in a closed position; a conveyor configured to receive the first food product through the first sidewall when the first door is in a partially open position or in an open position; and a means for circulating a cooling gas inside the chamber when the first door is in a partially closed position or in a closed position, wherein the cooling gas circulates inside the chamber flowing around the first food product.

15. The cryogenic freezing apparatus of Claim 14, further comprising: a second door positioned on a second sidewall of the chamber and configured to be in a partially open position, an open position, a partially closed position, or in a closed position, wherein the first food product exits the chamber on the conveyor through the second sidewall when the second door is in a partially open or in an open position, and2281-15 (P23D019-US) wherein the second sidewall is located at an opposite end of the chamber from the first sidewall.

16. The cryogenic freezing apparatus of Claim 14, wherein a second food product is received on the conveyor when the first door is in a partially open position or in an open position as the first food product is exiting the chamber through the second door or after the first food product has exited the chamber through the second door.

17. The cryogenic freezing apparatus of Claim 14, wherein the cooling gas is circulated inside the chamber around the first food product when the first door is in a partially closed position or in a closed position and a second door positioned on a second sidewall located at an opposite end of the chamber from the first sidewall is in a partially closed position or in a closed position.

18. The cryogenic freezing apparatus of Claim 14, further comprising: a plate separating the chamber into a first region and a second region, wherein the cooling gas circulates inside of the chamber in a first direction through the first region, and in a second direction through the second region opposite to the first direction 19. The cryogenic freezing apparatus of Claim 18, further comprising: a height adjustment mechanism configured to raise the plate in a direction away from the conveyor or lower the plate in a direction towards the conveyor.

20. The cryogenic freezing apparatus of Claim 14, further comprising: one or more magnets embedded in the first door; and a ferromagnetic material positioned beneath the first sidewall, wherein the one or more magnets are configured to pull the first door towards the ferromagnetic material using a magnetic force to close the first door.

21. The cryogenic freezing apparatus of Claim 14, further comprising:2281-15 (P23D019-US) an actuator configured to open the first door by raising the first door in a first vertical direction or close the first door by lowering the first door in a second vertical direction, wherein the first vertical direction is an opposite direction to the second vertical direction.

22. The cryogenic freezing apparatus of Claim 14, further comprising: a bottom support positioned beneath the conveyor; and a bypass restrictor positioned beneath the conveyor towards the front sidewall of the chamber and configured to restrict the cooling gas from flowing into a space beneath the bottom support to promote circulating the cooling gas around an outer surface of the first food product.

23. The cryogenic freezing apparatus of Claim 14, further comprising: one or more engagement mechanisms arranged on a plate in the chamber; and one or more attachment mechanisms arranged on a space filler, wherein the one or more engagement mechanisms are configured to attach to the one or more attachment mechanisms, thereby reducing a cross sectional area in a region below the plate.

24. The cryogenic freezing apparatus of Claim 14, wherein a velocity of the first food product is a first velocity when the first food product is received on the conveyor when the first door is in a partially open position or in an open position, wherein the velocity of the first food product is a second velocity when the first door is in a partially closed position or in a closed position, and wherein the first velocity is greater than the second velocity.

25. The cryogenic freezing apparatus of Claim 14, wherein the cooling gas is removed from the chamber at a first rate when the first door is in a partially closed position or in a closed position, and removed at a second rate that is less than the first rate when the first door is in a partially open position or in an open position.

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