Low-temperature combined drying device and method for rehydration type prefabricated vegetables

Abstract

The invention belongs to the technical field of intelligent preparation of prefabricated dishes, and particularly relates to a low-temperature combined drying device and method for rehydration type prefabricated dishes, and the low-temperature combined drying device comprises a shaping unit, a transfer unit and a freeze-drying unit; the shaping unit is arranged at the upper end of the transfer unit and used for low-temperature freezing and drying shaping of the food materials; the freeze-drying unit is arranged at the lower end of the transfer unit and used for low-temperature vacuum dehydration of the food materials; the upper end of the transfer unit is communicated with the shaping unit, the lower end of the transfer unit is communicated with the freeze-drying unit, and a movable partition plate assembly is arranged in the middle of the transfer unit; and the transfer unit is used for forming a channel for transferring the food materials from the shaping unit to the freeze-drying unit in the combined drying device. The invention aims to solve the problems of storage conditions, nutrition ingredients, eating taste, nutrition loss in the preparation process, high energy consumption, difficulty in forming, sanitation, safety and the like of the prefabricated dish.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent preparation of pre-prepared dishes, and in particular relates to a low-temperature combined drying device and method for rehydrating pre-prepared dishes. Background Art

[0002] Pre-prepared meals are the product of food industrialization, also known as pre-prepared conditioned foods. They generally refer to semi-finished or finished dishes that are made from various agricultural, livestock, poultry, and aquatic products as raw materials, with seasonings and other auxiliary materials (including food additives), and are processed through pre-selection, preparation, and cooking.

[0003] According to the classification of storage conditions, the common pre-prepared dishes on the market include quick-frozen pre-prepared dishes and room temperature pre-prepared dishes. Among them, quick-frozen pre-prepared dishes require low-temperature quick freezing of semi-finished ingredients during preparation to keep the nutritional components of the ingredients intact, but they also require a low-temperature environment during transportation and storage, which undoubtedly increases the cost and is not easy to preserve under field conditions; room temperature pre-prepared dishes require high-temperature sterilization of semi-finished ingredients during preparation to extend the shelf life, but high temperature will not only destroy the nutrients in the ingredients, but also cause the ingredients to lose their original taste, thereby reducing the quality of the pre-prepared dishes; in addition, whether it is quick freezing or high-temperature sterilization, it is not friendly to fruit and vegetable ingredients; fruit and vegetable ingredients, after quick freezing and thawing, the internal structure is destroyed and it is more likely to deteriorate and affect the taste, and under high temperature, fruit and vegetable ingredients will become soft and even melt, so fruit and vegetable ingredients are rarely added to existing pre-prepared dishes, and the nutrition is relatively simple.

[0004] In practice, it is found that vacuum drying pre-prepared dishes under low temperature can retain the nutritional components of the ingredients to the greatest extent without destroying the internal structure of the ingredients; the moisture content of the dried pre-prepared dishes is less than 5%, and it is difficult for microorganisms to survive, so they have a long shelf life; since they do not need to be sterilized at high temperature or simply quick-frozen, the internal structure of the fruit and vegetable ingredients in the pre-prepared dishes will not be affected; the dried pre-prepared dishes are small in size and light in weight, and can be stored at room temperature, saving a lot of transportation costs; when eating, you only need to rehydrate the dried pre-prepared dishes, which is convenient and fast, and suitable for environments where low-temperature storage conditions cannot be guaranteed in the wild. Therefore, preparing the ingredients into this type of rehydrated pre-prepared dishes can solve the problems existing in the above-mentioned quick-frozen pre-prepared dishes and room-temperature pre-prepared dishes.

[0005] Existing food freeze drying equipment is usually used for low-temperature vacuum drying of fresh fruits and vegetables, which quickly freezes the fruits and vegetables, and uses a vacuum pump to form a high vacuum inside the equipment. The water in the food is directly sublimated from solid ice to gaseous water vapor and discharged. The advantage of the freeze dryer is that it can directly sublimate the water in the food into gas under low temperature and vacuum environment, thereby retaining the original structure and properties of the food, avoiding side effects such as concentration, foaming and oxidation, and ensuring the purity and high quality of the food; in addition, the freeze dryer can maintain its nutrients by quickly and effectively removing the water in the food, reducing the growth environment and biological activity of bacteria and mold, thereby extending the shelf life of the food.

[0006] However, there are still many problems with using a freeze dryer to directly perform low-temperature drying on rehydrated pre-prepared dishes. First, the pre-prepared dishes are in a solid-liquid mixed state before drying. If they are directly put into a freeze dryer for drying, the outside will dry faster and the inside will dry slower, resulting in a long time and high energy consumption. Secondly, the finished products of rehydrated pre-prepared dishes need to be packaged in blocks, and it is difficult to cut the pre-prepared dishes into blocks after overall drying. Third, pre-prepared dishes in a solid-liquid mixed state are in contact with the external environment for a long time, which is prone to the growth of microorganisms, affecting the shelf life and food safety of the rehydrated pre-prepared dishes. Summary of the invention

[0007] The present invention provides a low-temperature combined drying device and method for rehydration-type pre-prepared dishes, which can solve the problems of storage conditions, nutritional ingredients, edible taste, nutritional loss during the preparation process, high energy consumption, difficulty in forming, and sanitation and safety of the pre-prepared dishes mentioned above. The specific contents are as follows:

[0008] A low-temperature combined drying device for rehydration-type pre-prepared dishes, comprising a shaping unit, a transport unit and a freeze-drying unit;

[0009] The shaping unit is arranged at the upper end of the transfer unit, and comprises a shaping portion having a plurality of vertically penetrating grids; the shaping unit is used for low-temperature freezing and dry shaping of food materials;

[0010] The freeze-drying unit is disposed at the lower end of the transport unit and is used for low-temperature vacuum dehydration of food materials;

[0011] The transfer unit is connected to the shaping unit at the upper end and the freeze-drying unit at the lower end, and a movable partition assembly is arranged in the middle; the transfer unit is used to form a channel inside the combined drying device for transferring food from the shaping unit to the freeze-drying unit.

[0012] Furthermore, the shaping unit comprises an upper cover, an upper box body and a refrigeration and drying system;

[0013] The upper cover has an edge that is hingedly connected to an edge of the upper end surface of the upper box body, and a sealing ring is formed on the edges around the lower end surface; a locking mechanism is provided between the upper cover and the upper box body;

[0014] The refrigeration and drying system is arranged outside the upper box body and communicated with the interior of the upper box body, and is used to provide cold energy and wind energy for the shaping unit;

[0015] The shaping portion is arranged inside the upper box body.

[0016] Furthermore, the refrigeration and drying system includes an exhaust device arranged on the side wall of the upper box body.

[0017] Furthermore, the transfer unit includes a middle box body with a groove hole on the side end face; the partition assembly is arranged in the middle box body so that it can move horizontally inward and outward through the groove hole; the upper and lower end faces of the partition assembly are provided with corresponding sealing gaskets that fit tightly with the lower end face of the molding part and the upper end face of the freeze-drying unit.

[0018] Furthermore, the transfer unit further comprises a translation transmission part and a translation drive part; the translation transmission part is arranged between the middle box body and the partition assembly; the translation drive part is arranged inside the middle box body;

[0019] The output end of the translation driving part cooperates with the input end of the translation transmission part to drive the partition assembly to move horizontally.

[0020] Further, the freeze-drying unit includes a refrigeration system, a vacuum system and a lower box;

[0021] The refrigeration system is arranged outside the lower box and communicated with the inside of the lower box, and is used to provide cold energy for the freeze-drying unit;

[0022] The vacuum system is arranged outside the lower box and communicated with the inside of the lower box, and is used to form a vacuum environment inside the freeze-drying unit.

[0023] Furthermore, a rotating driving part and a stirring part are provided inside the lower box;

[0024] The output end of the rotary driving part is connected to the stirring part and drives the stirring part to rotate;

[0025] The stirring part is made of a flexible elastically deformable material.

[0026] Furthermore, the freeze-drying unit also includes a flip door; the flip door has one edge hingedly connected to the edge of the side end surface of the lower box body, and a sealing ring is provided on the edges around the inner end surface; a locking mechanism is provided between the flip door and the lower box body.

[0027] Furthermore, the combined drying device further comprises a control system; the control system comprises an integrated setting panel, a display screen and a PLC, which are arranged on the outer end surface of the upper box body;

[0028] The control system is electrically connected to the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit;

[0029] The setting panel is used by the operator to set the start, stop, operation time, refrigeration temperature, vacuum degree, and start and stop of the translation drive unit and the rotation drive unit of the combined drying device;

[0030] The display screen is used to display the operating time, refrigeration temperature, vacuum degree and operating status of the combined drying device;

[0031] The PLC is used to control the start and stop of the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit according to the settings of the operator.

[0032] A method for using a rehydration type pre-prepared food low-temperature combined drying device, comprising:

[0033] S1. Ensure that the channel is in a closed state; evenly place the food to be processed into each grid of the shaping part; the food liquid level does not exceed two-thirds of the height of the grid;

[0034] S2, setting the operation time, refrigeration temperature and vacuum degree through the setting panel, and starting the combined drying device;

[0035] S3, after all the food is frozen, condensed and dried into a solid state, the PLC controls the refrigeration and drying system to stop working, and controls the translation drive unit to drive the partition assembly to move to the outside of the middle box through the translation transmission unit, and the channel is opened;

[0036] S4, pressing the food in the grid into the lower box one by one; the PLC controls the translation drive unit to drive the partition assembly to move into the middle box through the translation transmission unit, and the channel is closed;

[0037] S5, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit to start, and stirs and dehydrates the shaped food;

[0038] S6. After the freeze-drying of the food is completed, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit to stop; the food is taken out and packaged, and the preparation of the rehydrated pre-prepared dish is completed.

[0039] The beneficial effects of the present invention are:

[0040] 1. A shaping unit is provided to pre-treat the food before freeze-drying, preliminarily dry the food to remove surface moisture, and freeze it into divisible blocks, which is beneficial to save time and energy consumption during freeze-drying, and can be shaped for easy packaging;

[0041] 2. The transfer unit can form a channel inside the combined drying device for transferring food from the shaping unit to the freeze-drying unit, which reduces the chance of food contact with the outside world and is beneficial to food hygiene and safety;

[0042] 3. A freeze-drying unit is provided to dehydrate the ingredients by vacuuming them while they are frozen. The processed ingredients are formed into dry and repackable pre-prepared vegetable blocks. This type of rehydrated pre-prepared vegetable is beneficial for maintaining the nutrition and taste of the ingredients and reducing transportation and storage costs. Since the freeze-drying process will not affect fruits and vegetables, fruits and vegetables can be placed in the pre-prepared vegetable dishes, which increases the taste and dietary fiber. The rehydrated pre-prepared vegetable dishes only need to be soaked in water to be eaten, which is convenient and quick, and meets the food security needs in the wild environment where low-temperature preservation is not possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative work.

[0044] Figure 1 It is a schematic diagram of the overall structure of a low-temperature combined drying device for rehydration-type pre-prepared dishes;

[0045] Figure 2 It is a schematic diagram of the internal structure of a low-temperature combined drying device for rehydration-type pre-prepared dishes;

[0046] Figure 3 It is a schematic diagram of the overall structure of an embodiment of a low-temperature combined drying device for rehydrating pre-prepared dishes;

[0047] Figure 4 It is a schematic diagram of the internal structure of an embodiment of a low-temperature combined drying device for rehydrating pre-prepared dishes;

[0048] Figure 5 It is a schematic diagram of the overall structure of another embodiment of a rehydration type pre-prepared food low-temperature combined drying device;

[0049] Figure 6 This is a schematic diagram of the structure of the partition assembly of the low-temperature combined drying device for rehydration-type pre-prepared dishes;

[0050] Figure 7 It is a structural schematic diagram of the rotary drive unit and the stirring unit of the low-temperature combined drying device for rehydration-type pre-prepared dishes;

[0051] In the figure: 1. shaping unit; 101. shaping part; 102. upper cover; 103. upper box; 104. propulsion mechanism; 105. propulsion block; 106. propulsion platform; 107. elastic part; 108. propulsion drive part; 109. propulsion transmission part; 110. shell; 2. transfer unit; 201. partition assembly; 202. slot hole; 203. middle box; 204. sealing pad; 205. translation transmission part; 3. freeze-drying unit; 301. lower box; 302. rotation drive part; 303. stirring part; 304. flip door; 4. control system. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0054] It should be noted that when an element is referred to as being "fixed to", "placed on", "disposed with", "provided with", "set to", "arranged to" or "connected to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0055] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] Please refer to the attached Figures 1 to 7In order to better understand the specific structure and working principle of the present invention. A low-temperature combined drying device for rehydrating pre-prepared dishes, such as Figure 1 As shown, it includes a shaping unit 1, a transport unit 2 and a freeze-drying unit 3;

[0057] The shaping unit 1 is disposed at the upper end of the transfer unit 2, and includes a shaping portion 101 having a plurality of vertically penetrating grids; the shaping unit 1 is used for low-temperature freezing and dry shaping of food materials;

[0058] The freeze-drying unit 3 is disposed at the lower end of the transport unit 2 and is used for low-temperature vacuum dehydration of food materials;

[0059] The transport unit 2 is connected to the shaping unit 1 at the upper end and to the freeze-drying unit 3 at the lower end, and a movable partition assembly 201 is provided in the middle. Figure 2 As shown; the transfer unit 2 is used to form a channel inside the combined drying device for transferring food from the shaping unit 1 to the freeze-drying unit 3.

[0060] It should be noted that the shaping portion 101 is preferably made of several metal plates, such as stainless steel, which are welded or integrally formed to form a grid structure; the number of grids is not limited and can be determined according to specific needs in implementation; the grid cross-sectional shape can be rectangular or square, and the grid height and cross-sectional shape can be determined according to the shape and mass of the finished rehydrated pre-prepared dish.

[0061] In a specific implementation, the present invention is provided with a shaping unit 1, which can perform pretreatment on food materials before freeze-drying, preliminarily dry the food materials to remove surface moisture, and freeze them into divisible blocks, which is beneficial to saving time and energy consumption during freeze-drying, and can be shaped for easy packaging; the present invention is provided with a transfer unit 2, which can form a channel for transferring food materials from the shaping unit 1 to the freeze-drying unit 3 inside the combined drying device, reducing the probability of food materials contacting the outside world, which is beneficial to the hygiene and safety of food; the present invention is provided with a freeze-drying unit 3, which can dehydrate the food materials by vacuuming while freezing, and the processed food materials can be formed into dry and divisible pre-prepared vegetable blocks; this rehydrated pre-prepared dish is beneficial to maintaining the nutrition and taste of the food materials, and reduces the transportation and storage costs; since the freeze-drying process will not affect fruits and vegetables, it is possible to place fruit and vegetable ingredients in the pre-prepared dish, thereby increasing the taste and dietary fiber; and the rehydrated pre-prepared dish only needs to be soaked in water to be eaten, which is convenient and quick, and meets the food security needs in the wild environment where low-temperature storage is not possible.

[0062] In one embodiment provided by the present invention, Figure 2 As shown, the shaping unit 1 includes an upper cover 102, an upper box body 103, a refrigeration and drying system and a shaping part 101;

[0063] The upper cover 102 has one edge hingedly connected to one edge of the upper end surface of the upper box body 103, and a sealing ring is formed around the edges of the lower end surface; a locking mechanism is provided between the upper cover 102 and the upper box body 103;

[0064] The refrigeration and drying system is arranged outside the upper box 103 and communicated with the interior of the upper box 103, and is used to provide cold energy and wind energy for the shaping unit 1;

[0065] The shaping portion 101 is disposed inside the upper box body 103 .

[0066] The refrigeration and drying system includes an exhaust device arranged on the side wall of the upper box body 103 .

[0067] It should be noted that the upper cover 102 preferably adopts an upward flip-up opening method; the locking mechanism between the upper cover 102 and the upper box body 103 (not shown in the figure) preferably adopts a lock structure, and other commonly used similar structures can also be used as long as it can play the role of locking and unlocking the upper cover 102 and the upper box body 103.

[0068] It should be noted that sealing rings are formed around the edges of the lower end surface of the upper cover 102, and the sealing rings are preferably fixed to the upper cover 102 by gluing; the sealing rings are preferably made of silicone material, which can better seal the gap formed after the upper cover 102 and the upper box body 103 are buckled together.

[0069] It should be noted that the refrigeration and drying system can be fixed by separately installing a box body outside the upper box body 103 and communicated with the interior of the upper box body 103 through a pipeline.

[0070] It should be noted that the refrigeration drying system is an existing technology, which uses refrigeration equipment to provide a low-temperature environment, and then uses a blower to blow cold air to the food. It can dry the surface moisture while freezing the food, and finally form frozen blocks of food in each grid.

[0071] It should be noted that the shaping portion 101 is preferably fixed to the upper box body 103 by welding or a supporting structure at the bottom of the upper box body 103 .

[0072] It should be noted that the exhaust device is preferably installed on the through hole opened on the side wall of the upper box body 103, and a one-way check valve is installed to discharge the dried water vapor to the outside.

[0073] In specific implementation, the refrigeration and drying system can provide pre-treatment for food before freeze-drying and shape the food for subsequent packaging; freezing the food into ice in advance and air-drying to remove surface moisture can help reduce energy consumption and shorten the time of the freeze-drying process.

[0074] In one embodiment, if Figure 4 , Figure 6 The transfer unit 2 includes a middle box body 203 with a slot 202 formed on the side end surface; the partition assembly 201 is arranged in the middle box body 203 so as to be horizontally movable inward and outward through the slot 202; the upper and lower end surfaces of the partition assembly 201 are provided with corresponding sealing gaskets 204 that are tightly fitted with the lower end surface of the shaping portion 101 and the upper end surface of the freeze-drying unit 3.

[0075] The transfer unit 2 further includes a translation transmission part 205 and a translation driving part; the translation transmission part 205 is arranged between the middle box body 203 and the partition assembly 201; the translation driving part is arranged inside the middle box body 203;

[0076] The output end of the translation driving unit cooperates with the input end of the translation transmission unit 205 to drive the partition assembly 201 to move horizontally.

[0077] It should be noted that platforms are fixed on both sides of the middle box body 203, and the partition assembly 201 can move under the support of the platforms.

[0078] It should be noted that the sealing gasket 204 is preferably made of silica gel material, which can completely seal the passages between the shaping unit 1, the freeze-drying unit 3 and the transport unit 2 to form a better sealing environment.

[0079] It should be noted that the translation transmission part 205 is preferably a gear rack transmission mechanism; the translation drive part is preferably a stepper motor; the rack is fixed on one side or both sides of the partition assembly 201; the gear is fixed to the output shaft of the stepper motor; the stepper motor is fixed on one side or both sides of the middle box 203; the gear and the rack are meshed; the stepper motor is started to drive the gear to rotate, and then drive the rack and the partition assembly 201 to move horizontally inside and outside the middle box 203.

[0080] It should be noted that, in order to prevent the partition assembly 201 from tilting downward when it is moved out of the middle box 203 , a horizontal bracket can be fixed at the lower outer side of the slot hole 202 of the middle box 203 to support the partition assembly 201 .

[0081] In a specific implementation, the transfer unit 2 can form a channel inside the combined drying device for transferring food from the shaping unit 1 to the freeze-drying unit 3, thereby reducing the probability of food contact with the outside world during preparation and increasing food safety.

[0082] In one embodiment, if Figure 3 As shown, the freeze-drying unit 3 includes a refrigeration system, a vacuum system and a lower box 301;

[0083] The refrigeration system is arranged outside the lower box 301 and communicated with the inside of the lower box 301, and is used to provide cold energy for the freeze-drying unit 3;

[0084] The vacuum system is disposed outside the lower box 301 and communicated with the interior of the lower box 301 , and is used to form a vacuum environment inside the freeze-drying unit 3 .

[0085] It should be noted that the refrigeration system is preferably a refrigeration device commonly used in the prior art, which can achieve a refrigeration environment of -30°.

[0086] It should be noted that the vacuum system is preferably a vacuum pumping device commonly used in the prior art. The vacuum system may also include a vacuum gauge disposed in the lower box 301 to monitor the vacuum degree.

[0087] It should be noted that the refrigeration system and the vacuum system are preferably installed in a fixed box outside the lower box 301.

[0088] In specific implementation, the refrigeration system and the vacuum system can achieve low-temperature vacuum drying of food materials. This method retains the nutritional components and taste of the food materials to the greatest extent, extends the shelf life, and facilitates transportation and storage.

[0089] In one embodiment provided by the present invention, Figure 7 As shown, a rotating driving part 302 and a stirring part 303 are provided inside the lower box 301;

[0090] The output end of the rotation driving part 302 is connected to the stirring part 303 and drives the stirring part 303 to rotate;

[0091] The stirring portion 303 is made of a flexible and elastically deformable material.

[0092] It should be noted that the rotation driving part 302 is preferably a stepping motor; the stirring part 303 is preferably a fan blade structure; the output shaft of the stepping motor is connected to the transmission shaft of the fan blade, and drives the fan blade to rotate.

[0093] It should be noted that the stirring portion 303 is made of a flexible and elastically deformable material, preferably a rubber or silicone material, which can prevent the food blocks from being crushed during the stirring process.

[0094] In a specific implementation, a stirring portion 303 is provided in the lower box body 301, so that all surfaces of the formed food can be fully exposed to the environment during the freeze-vacuum drying process, which is beneficial to speed up the drying speed and save time and energy consumption.

[0095] In one embodiment, if Figure 4 As shown, the freeze-drying unit 3 also includes a flip door 304; the flip door 304 has an edge hingedly connected to the edge of the side end face of the lower box body 301, and a sealing ring is provided on the edges around the inner end face; a locking mechanism is provided between the flip door 304 and the lower box body 301.

[0096] It should be noted that the sealing ring is preferably made of silicone material; the sealing ring is preferably fixed to the edges of the flip door 304 by gluing.

[0097] It should be noted that the locking mechanism (not shown in the figure) preferably adopts a lock structure, and other commonly used similar structures can also be used as long as it can lock and unlock the flip door 304 and the lower box body 301.

[0098] In an embodiment provided by the present invention, the combined drying device further comprises a control system 4; the control system 4 comprises an integrated setting panel, a display screen and a PLC, which are arranged on the outer end surface of the upper box body 103;

[0099] The control system 4 is electrically connected to the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit 302;

[0100] The setting panel is used by the operator to set the start, stop, operation time, cooling temperature, vacuum degree, and start and stop of the translation drive unit and the rotation drive unit 302 of the combined drying device;

[0101] The display screen is used to display the operating time, refrigeration temperature, vacuum degree and operating status of the combined drying device;

[0102] The PLC is used to control the start and stop of the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit 302 according to the settings of the operator.

[0103] It should be noted that the control system 4 is embedded in the front side wall of the upper box body 103; PLC (Programmable Logic Controller) can also be a circuit including at least one processor, or a circuit including at least one single-chip microcomputer, or a combination of multiple circuits or chips, as long as the corresponding functions can be achieved; it is understandable that for those skilled in the art, the control circuit can also be a common circuit composed of amplifiers, comparators, triodes, MOS tubes, etc. to achieve the corresponding functions in a purely hardware manner.

[0104] In a specific implementation, the control system 4 can realize the automatic control of the combined drying device, which is beneficial to the preparation of rehydration type pre-prepared dishes.

[0105] In one embodiment, Figure 3 , Figure 4As shown, the shaping unit 1 can add a propulsion mechanism 104; the propulsion mechanism 104 is arranged on the upper cover 102, preferably installed in the form of an opening in the upper cover 102, and can move up and down relative to the upper cover 102, and includes propulsion blocks 105, a propulsion platform 106 and an elastic part 107, which are equal in number and shape to the grid; the upper end of each propulsion block 105 is fixedly connected to the propulsion platform 106, and can be fixed by welding; the elastic part 107 is preferably a helical cylindrical spring structure, fixed between the propulsion platform 106 and the upper cover 102, and plays a role in returning the propulsion unit.

[0106] It should be noted that after the shaping unit 1 completes the food preprocessing, the pushing platform 106 can be pressed down, and the shaped food in each grid can be pushed into the freeze-drying unit 3 through the pushing block 105; the pushing platform 106 and the pushing block 105 return to the initial position under the action of the elastic part 107.

[0107] In one embodiment, Figure 5 As shown, the propulsion mechanism 104 can add a propulsion drive unit 108 and a propulsion transmission unit 109; the propulsion transmission unit 109 is arranged between the upper cover 102 and the propulsion platform 106; the propulsion drive unit 108 is arranged on the propulsion platform 106, and the output end cooperates with the input end of the propulsion transmission unit 109.

[0108] It should be noted that the propulsion drive unit 108 is preferably a stepper motor; the propulsion transmission unit 109 is preferably a gear rack and a bevel gear transmission mechanism; the rack, the lower end of which is welded or fixed to both sides of the upper cover 102 by a threaded structure, the middle part passes through the through hole of the propulsion platform 106, and extends to the upper end of the propulsion platform 106, and the propulsion platform 106 can move up and down relative to the rack; the two racks are connected by a connecting shaft, and gears meshing with the racks are welded on both sides of the connecting shaft; a first bevel gear is welded or keyed in the middle of the connecting shaft; the connecting shaft, gears, and bevel gears are all installed in the shell 110 for protection; the propulsion drive unit 108 is fixed on the shell 110, and the output shaft is fixed with a second bevel gear, which is electrically connected to the control system 4; the second bevel gear passes through the hole opened in the shell 110 and meshes with the first bevel gear.

[0109] After the shaping unit 1 completes the pretreatment of the food, the PLC can control the start of the propulsion drive unit 108; the second bevel gear drives the first bevel gear to rotate, and transmits the power to both sides, and changes 90°; the gears on both sides are meshed with the racks on both sides, driving the propulsion mechanism 104 to move downward as a whole, and the shaped food in each grid is pushed to the freeze-drying unit 3 through the propulsion block 105; the PLC controls the propulsion drive unit 108 to reverse, and the propulsion platform 106 and the propulsion block 105 return to the initial position.

[0110] In a specific implementation, setting up a propulsion mechanism 104 can replace the manual pressing down of the ingredients in the grid one by one, saving time, and there is no need to open the upper cover 102 to further ensure food hygiene and safety; adding a propulsion drive unit 108 and a propulsion transmission unit 109 can realize automatic control, save personnel strength, and optimize the preparation process.

[0111] In one embodiment, the lower box 301 is provided with a temperature sensor, a vacuum pressure sensor, a rotation speed sensor and a moisture sensor which are all electrically connected to the PLC, and are respectively used to obtain the temperature value and vacuum value in the lower box 301, the rotation speed value of the stirring part 303 and the dryness value of the food in real time;

[0112] The PLC obtains the temperature value, vacuum value, speed value and dryness value, processes the temperature value, vacuum value, speed value and dryness value using a dynamic programming energy consumption control model, obtains a temperature change value, a vacuum change value and a speed change value under a minimized objective function, and continuously adjusts the temperature value T, vacuum value P and speed value v by controlling the operating states of a refrigeration system, a vacuum system and a rotary drive unit. stir , so that the current dryness value reaches the target dryness value; the expression of the dynamic programming energy consumption control model is:

[0113]

[0114] Where: J is the objective function; N is the number of steps; e(i) is the error value, η target is the target dryness value, is the first predicted dryness value, when i=1 is the dryness value measured by the moisture sensor; λ1, λ2 and λ3 are weight coefficients; ΔT, ΔP and Δv stir The corresponding values ​​are the temperature change value, vacuum change value and speed change value;

[0115] The constraints of the dynamic programming energy consumption control model are:

[0116] T min ≤T≤T max ,P min ≤P≤P max ,

[0117] T min is the minimum temperature, T max is the maximum temperature, P min is the minimum vacuum degree, P max

[0118] is the maximum vacuum degree, is the minimum speed, The maximum speed.

[0119] It should be noted that the dynamic programming energy consumption control model can be applied to the energy consumption control of freeze-drying of different ingredients. By continuously adjusting the temperature, vacuum and rotation speed values, the internal environment of the lower box can be optimized in real time, thereby achieving the lowest energy consumption.

[0120] It should be noted that the constraint on temperature T can prevent the material from melting (temperature is too high) or incomplete freezing (temperature is too low); the constraint on pressure P can ensure that the vacuum degree is sufficient to maintain sublimation and desorption (two important stages in the freeze-drying process, the dryness of the food in the sublimation stage η<0.8, and the dryness of the food in the desorption stage η≥0.8), while avoiding excessive vacuuming and increasing energy consumption; the speed v of the stirring part 303 can be set to the same value. stir to prevent uneven heating of ingredients due to material breakage or uneven stirring; N is the number of steps, which can be understood as the prediction time domain, and N=5 is optional, indicating the prediction of dryness in the next five control cycles (each cycle can be optionally set to 30 seconds, which can also be understood as the sampling cycle); the weight coefficients of λ1, λ2 and λ3 are preferably obtained through experimental tests, and the optimal values ​​in this system are 0.8, 0.8 and 0.5.

[0121] In one embodiment, the PLC obtains the temperature change value, vacuum change value and speed change value, and calculates the dryness change value of the food using a drying kinetics model. The expression of the drying kinetics model when the moisture in the food is in the sublimation stage is:

[0122]

[0123] The expression of the drying kinetic model when the moisture in the food is in the desorption stage is:

[0124]

[0125] Where: η is the dryness value; k1 is the mass transfer coefficient; k2 is the bound water desorption coefficient; T opt is the optimal desorption temperature; T max and T min The corresponding maximum and minimum allowable temperature values; P min is the minimum allowable vacuum value; the PLC obtains the dryness change value to obtain the second predicted dryness value η at time t next The expression is:

[0126]

[0127] The PLC obtains and processes the second predicted dryness value to obtain a total error value e total (i), the expression is: etotal (i) = e(i) + δ(η target -η next ), δ is the weight coefficient;

[0128] The PLC obtains the total error value, and uses the dynamic programming energy consumption control model to obtain the corrected temperature change value, vacuum change value and speed change value, and the expression is:

[0129]

[0130] It should be noted that is the drying rate; the optimal desorption temperature T opt , which is 1.1 to 1.2 times the glass transition temperature of the food, and -25°C is preferred in this system; the mass transfer coefficient k1 is related to the porosity of the material, and 0.05 is preferred in this system; the bound water desorption coefficient k2 is related to the energy barrier for bound water molecules to detach from the surface or internal structure of the material, and 0.005 is preferred in this system; the food will experience a sublimation stage and a desorption stage during the freeze-drying process, and the dryness values ​​of the two stages are η<0.8 and η≥0.8 respectively; during the control process, the drying rate calculation formulas of the two states can be switched according to the collected dryness values.

[0131] It should be noted that the dynamic programming energy consumption control model is a feedforward-feedback control strategy based on a dynamic model, which achieves the control target through rolling optimization and feedback correction; its core steps are as follows:

[0132] Prediction model: Use the drying dynamics model to predict the change of dryness in the future (prediction time domain);

[0133] Objective function: Minimize the deviation of the predicted dryness from the target value while limiting the energy consumption of parameter adjustment.

[0134] Rolling optimization: recalculate the optimal parameters in each control cycle, execute only the control instructions of the first step, and iterate in a loop. That is, in each sampling period t, re-solve the objective function based on the current state to obtain the optimal control sequence {T(t), P(t), v stir (t)}, but only the control amount of the first step is executed, and the subsequent steps are recalculated in the next cycle.

[0135] In one embodiment, the PLC uses a concrete logic algorithm to compensate and adjust the temperature value T and vacuum value P output by the dynamic programming energy consumption control model when the drying device is in a nonlinear response and external interference state; the concrete logic algorithm includes:

[0136] Concrete, dryness deviation Δη and dryness deviation change rate Converted into a set of dryness deviation language values: {"negative large", "negative small", "zero", "positive small", "positive large"}, and dryness change rate language values: {"rapidly decreasing", "slowly decreasing", "unchanged", "slowly increasing", "rapidly increasing"};

[0137] The concrete rule base combines the dryness deviation language value and the dryness change rate language value according to the expert experience and converts them into the pre-adjusted temperature correction value δT stored in the concrete rule base. i And pre-adjusted vacuum correction value δP j Form a trigger rule, where i and j are both positive integers ≥ 1;

[0138] Specifically, when the drying device reaches the trigger rule condition, the discrete centroid method is used to obtain the final temperature correction value δT and vacuum correction value δP.

[0139] It should be noted that According to the language value set and expert experience, 20 pre-adjusted temperature correction values ​​δT can be obtained. i and 20 pre-adjusted vacuum correction values ​​δP j , forming a concrete rule base; the discrete centroid method is a conventional algorithm, in which the rule triggering degree selection value can be determined based on expert experience.

[0140] In a specific implementation, the present invention combines a dynamic programming energy consumption control model with a concrete logic algorithm, wherein the dynamic programming energy consumption control model is used as a main controller to provide global optimization parameters (T, P, vstir), and the concrete logic algorithm is used as a compensator to fine-tune the output of the dynamic programming energy consumption control model to obtain (δT, δP), thereby forming a dynamic priority: for example, when the dryness deviation is large (such as Δη>10%), the correction amount of the concrete logic is dominant; when it is close to the target value (such as Δη<2%), the optimization weight of the dynamic programming energy consumption control model is higher; thereby achieving the accuracy and robustness of the drying process; the dynamic programming energy consumption control model ensures efficient approach to the target within the model prediction range, while the concrete logic algorithm dynamically responds to the uncertainty and nonlinear interference in actual production, and the two work together to significantly improve the control performance of the freeze-drying unit.

[0141] Furthermore, the relationship between the dynamic programming energy consumption control model and the drying kinetics model is reflected in a closed-loop system of prediction, optimization and dynamic adjustment: the drying kinetics model provides a theoretical framework for the drying process, which is the basis for prediction and optimization of the dynamic programming energy consumption control model. The kinetic model predicts the change law of the next step of dryness, and the predicted dryness value for the next step can be obtained; the predicted dryness value is weighted and calculated with the actual measured dryness value to obtain the overall dryness error; the operation of the system can be controlled more accurately; the dynamic programming energy consumption control model optimizes the control input in real time, and uses the predicted value provided by the drying kinetics model to correct the total error, so that the system can adapt to the actual production process. The uncertainty in production; the synergy of the two realizes the high efficiency (shortening time and reducing energy consumption) and robustness (responding to interference and parameter changes) of the drying process; by reasonably simplifying the model, designing adaptive strategies and optimizing the time domain selection, the drying dynamics model can play an important role in complex drying scenarios; through practical tests: the overall drying time of ingredients can be reduced by 15% to 20%; the total energy consumption is reduced by about 25%; and the local overheating or undried areas of ingredients are reduced through the coordinated control of stirring speed and vacuum degree; through model predictive control and concrete logic compensation, the precise dynamic optimization of the freeze-drying process is achieved, taking into account both drying efficiency and energy consumption, which can significantly improve the quality and production economy of rehydrated pre-prepared dishes.

[0142] A method for using a rehydration type pre-prepared food low-temperature combined drying device, comprising:

[0143] S1, ensuring that the channel is in a closed state; evenly placing the food to be processed into each grid of the shaping portion 101; the food liquid level does not exceed two-thirds of the height of the grid;

[0144] S2, setting the operation time, refrigeration temperature and vacuum degree through the setting panel, and starting the combined drying device;

[0145] S3, after all the food is frozen, condensed and dried into a solid state, the PLC controls the refrigeration and drying system to stop working, and controls the translation drive unit to drive the partition assembly 201 to move to the outside of the middle box 203 through the translation transmission unit 205, and the channel is opened;

[0146] S4, pressing the food in the grid into the lower box 301 one by one; the PLC controls the translation drive unit to drive the partition assembly 201 to move into the middle box 203 through the translation transmission unit 205, and the channel is closed;

[0147] S5, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit 302 to start, and stir and dehydrate the shaped food;

[0148] S6. After the freeze-drying of the food is completed, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit 302 to stop; the food is taken out and packaged, and the preparation of the rehydrated pre-prepared dish is completed.

[0149] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0150] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A low-temperature combined drying device for rehydrating pre-prepared dishes, characterized in that: It includes a shaping unit, a transport unit and a freeze-drying unit; The shaping unit is arranged at the upper end of the transfer unit, and comprises a shaping portion having a plurality of vertically penetrating grids; the shaping unit is used for low-temperature freezing and dry shaping of food materials; The transfer unit is connected to the shaping unit at the upper end and the freeze-drying unit at the lower end, and a movable partition assembly is provided in the middle; the transfer unit is used to form a channel inside the combined drying device for transferring food from the shaping unit to the freeze-drying unit; The freeze-drying unit is arranged at the lower end of the transfer unit and is used for low-temperature vacuum dehydration of food materials.

2. The low-temperature combined drying device for rehydrated pre-prepared dishes according to claim 1, characterized in that: The shaping unit comprises an upper cover, an upper box body and a refrigeration and drying system; The upper cover has an edge that is hingedly connected to an edge of the upper end surface of the upper box body, and a sealing ring is formed on the edges around the lower end surface; a locking mechanism is provided between the upper cover and the upper box body; The refrigeration and drying system is arranged outside the upper box body and communicated with the interior of the upper box body, and is used to provide cold energy and wind energy for the shaping unit; The shaping portion is arranged inside the upper box body.

3. The low-temperature combined drying device for rehydrated pre-prepared dishes according to claim 2, characterized in that: The refrigeration and drying system comprises an exhaust device arranged on the side wall of the upper box body.

4. The low-temperature combined drying device for rehydrated pre-prepared dishes according to claim 3, characterized in that: The transfer unit includes a middle box body with a slot hole formed on the side end surface; the partition assembly is arranged in the middle box body and can be horizontally moved inward and outward through the slot hole; the upper and lower end surfaces of the partition assembly are provided with corresponding sealing gaskets that are tightly fitted with the lower end surface of the shaping part and the upper end surface of the freeze-drying unit.

5. The low-temperature combined drying device for rehydrated prepared dishes according to claim 4, characterized in that: The transfer unit further comprises a translation transmission part and a translation driving part; the translation transmission part is arranged between the middle box and the partition assembly; the translation driving part is arranged inside the middle box; The output end of the translation driving part cooperates with the input end of the translation transmission part to drive the partition assembly to move horizontally.

6. The low-temperature combined drying device for rehydrating prepared dishes according to claim 1, characterized in that: The freeze-drying unit comprises a refrigeration system, a vacuum system and a lower box; The refrigeration system is arranged outside the lower box and communicated with the inside of the lower box, and is used to provide cold energy for the freeze-drying unit; The vacuum system is arranged outside the lower box and communicated with the inside of the lower box, and is used to form a vacuum environment inside the freeze-drying unit.

7. The low-temperature combined drying device for rehydrated prepared dishes according to claim 6, characterized in that: The lower box is provided with a rotating driving part and a stirring part; The output end of the rotary driving part is connected to the stirring part and drives the stirring part to rotate; The stirring part is made of a flexible elastically deformable material.

8. The low-temperature combined drying device for rehydrating prepared dishes according to claim 7, characterized in that: The freeze-drying unit also includes a flip door; one edge of the flip door is hingedly connected to the edge of the side end surface of the lower box body, and a sealing ring is arranged around the edges of the inner end surface; a locking mechanism is formed between the flip door and the lower box body.

9. The low-temperature combined drying device for rehydrated prepared dishes according to any one of claims 1 to 8, characterized in that: The combined drying device further comprises a control system; the control system comprises a setting panel, a display screen and a PLC integrated into one body, and is arranged on the outer end surface of the upper box body; The control system is electrically connected to the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit; The setting panel is used by the operator to set the start, stop, operation time, refrigeration temperature, vacuum degree, and start and stop of the translation drive unit and the rotation drive unit of the combined drying device; The display screen is used to display the operating time, refrigeration temperature, vacuum degree and operating status of the combined drying device; The PLC is used to control the start and stop of the refrigeration and drying system, the refrigeration system, the vacuum system, the translation drive unit and the rotation drive unit according to the settings of the operator.

10. A method for using a rehydration type pre-prepared food low-temperature combined drying device, applied to the rehydration type pre-prepared food low-temperature combined drying device according to any one of claims 1 to 8, characterized in that: include: S1. Ensure that the channel is in a closed state; evenly place the food to be processed into each grid of the shaping part; the food liquid level does not exceed two-thirds of the height of the grid; S2, setting the operation time, refrigeration temperature and vacuum degree through the setting panel, and starting the combined drying device; S3, after all the food is frozen, condensed and dried into a solid state, the PLC controls the refrigeration and drying system to stop working, and controls the translation drive unit to drive the partition assembly to move to the outside of the middle box through the translation transmission unit, and the channel is opened; S4, pressing the food in the grid into the lower box one by one; the PLC controls the translation drive unit to drive the partition assembly to move into the middle box through the translation transmission unit, and the channel is closed; S5, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit to start, and stirs and dehydrates the shaped food; S6. After the freeze-drying of the food is completed, the PLC controls the refrigeration system, the vacuum system and the rotary drive unit to stop; the food is taken out and packaged, and the preparation of the rehydrated pre-prepared dish is completed.

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