A low temperature bubble thawing delivery system and thawing method

Abstract

The present application relates to food frozen raw material thawing processing technical field, disclose a kind of low-temperature bubble thawing conveying system and thawing method, the system includes air compressor, thawing pool, aeration unit, temperature regulating unit, conveying unit and impurity removal mechanism;Aeration coil is along the width direction of thawing pool and the gradient of opening rate decreases, can drive liquid surface scum directional migration aggregation, pool bottom is set to concentrate residue gap corresponding aeration coil to enrich sediment, residue valve, liquid discharge control valve are linked with liquid supplement control valve, and impurity removal process is synchronized with liquid supplement to stabilize liquid level.The present application method includes liquid level preparation, feeding soaking, bubble constant-temperature thawing, linkage impurity removal, continuous discharging steps, and the thawing liquid temperature can be stably maintained in the preset low-temperature thawing environment.The present application can remove thawing impurities on line, without stopping emptying cleaning, with low-temperature preservation and production continuity, suitable for frozen meat food material scale continuous thawing production.

Description

Technical Field

[0001] This invention relates to the field of food frozen raw material thawing and processing technology, specifically to a low-temperature bubble thawing and conveying system and thawing method. Background Technology

[0002] In large-scale food processing systems, frozen storage is the primary method for preserving raw materials such as livestock and poultry meat and aquatic products. Thawing, as a core pre-processing step, directly determines the efficiency, uniformity, and hygiene of subsequent processing and the quality of the final product. Currently, the thawing technologies used in the industry include various types such as natural static thawing, water bath thawing, microwave thawing, and high-voltage electrostatic thawing. Among them, water bath bubble thawing has become the mainstream batch thawing solution for large and medium-sized food enterprises due to its advantages such as high heat exchange efficiency, low equipment cost, and ease of continuous production.

[0003] Existing continuous bubble thawing equipment generally adopts a basic architecture combining a thawing tank, a bottom aeration system, and a conveying and lifting mechanism. For example, Chinese utility model patent CN211960779U discloses a continuous bubble thawing machine. Its thawing tank is a top-opening trough structure, with multiple aeration coils arranged parallel to each other along the length of the tank bottom. Air outlets are evenly distributed on the sidewalls of the coils and connected to an external compressed air source. The lifting conveyor belt adopts a mesh chain plate structure, erected at a fixed inclination angle, with its lower end extending into the thawing tank and its upper end extending to the outside of the discharge side of the thawing tank. It is driven by a drive mechanism to circulate. During operation, the frozen meat to be thawed is placed into the water bath environment of the thawing tank. Compressed air is continuously blown into the water through the aeration coils, forming rising bubbles. This creates turbulence in the water, washing over the surface of the frozen meat and enhancing heat exchange to accelerate the thawing rate. The material gradually moves with the water flow to the lower end of the lifting conveyor belt, where it is supported and lifted before sliding down from the upper end for discharge, achieving continuous thawing and output of the frozen meat.

[0004] This type of continuous bubble thawing equipment still has shortcomings in actual industrial production applications: During the water bath thawing process of frozen meat, soluble proteins, fats, and other substances precipitated on the surface form foam that floats on the liquid surface, while solid impurities such as detached meat scraps and bone fragments settle at the bottom of the tank, forming sediment. Existing equipment lacks a matching online impurity removal structure, making it impossible to effectively collect and continuously discharge the foam on the liquid surface and the sediment at the bottom of the tank. The thawing liquid is continuously contaminated by impurities, accelerating microbial growth and increasing the risk of food safety management. At the same time, the cleaning of impurities in the tank requires stopping the machine and emptying the entire tank of thawing liquid, and then manually cleaning it. The cleaning cycle is long, the operation is cumbersome, and it disrupts the continuous production rhythm, which is not conducive to improving production efficiency. Summary of the Invention

[0005] The present invention aims to provide a low-temperature bubble thawing conveying system and thawing method to solve the problems of existing continuous bubble thawing equipment being unable to remove surface foam and bottom sediment online, the thawing liquid being prone to continuous pollution, and the need to shut down and drain the equipment for cleaning, thus interrupting production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a low-temperature bubble thawing and conveying system and thawing method, comprising a thawing tank, an aeration unit, a temperature regulating unit, and a conveying unit; further comprising a purification mechanism, wherein the purification mechanism includes: A filtration tank is located adjacent to the thawing tank on one side and contains a filter assembly. A foam removal component is installed on the thawing tank. The foam removal component includes a strip-shaped overflow port on the upper part of the side wall of the thawing tank, a drain pipe connecting the strip-shaped overflow port and the impurity removal tank, and a drain control valve installed on the drain pipe. When the drain control valve is closed, the drain pipe is cut off. When it is open, the surface thawing liquid with a liquid level higher than the bottom edge of the strip-shaped overflow port is discharged into the impurity removal tank through the strip-shaped overflow port and the drain pipe. The aeration unit includes an air compressor and multiple aeration coils. The opening ratio of the aeration coils along the width direction of the thawing tank gradually decreases from the side away from the strip-shaped overflow port to the side closer to the strip-shaped overflow port to form a liquid surface fluctuation gradient, driving the surface foam to migrate and accumulate directionally towards the side of the strip-shaped overflow port. A sludge removal component is installed at the bottom of the thawing tank. The component includes a sludge collection ditch located at the bottom of the thawing tank, corresponding to the gaps in the aeration coils, and a sludge discharge valve located at the lowest point of the sludge collection ditch. The bottom circulation formed by aeration can flush and enrich the sludge in the sludge collection ditch. The outlet of the sludge discharge valve is connected to a debris removal tank. A replenishment tank is installed on the thawing pool and connected to the thawing pool through a replenishment pipeline with a replenishment control valve. The slag discharge valve and the liquid discharge control valve are both linked to the replenishment control valve so as to replenish the thawing pool with thawing fluid simultaneously when discharging slag or foam.

[0007] The principle and advantages of this solution are as follows: In practical application, the air compressor continuously blows compressed air into the thawing tank through the aeration coil, forming a large number of rising bubbles that drive water turbulence, enhance heat exchange on the surface of frozen meat, and accelerate the melting rate of the ice layer. The gradient opening layout of the aeration coil creates a liquid surface undulation gradient in the tank, driving the surface foam to automatically migrate and accumulate towards the strip overflow outlet. At the same time, the bottom circulation formed by aeration washes and enriches the sediment in the sludge collection ditch. During the impurity removal operation, opening the drain control valve can discharge the enriched foam and surface thawing liquid, and opening the sludge discharge valve can discharge the sediment in the sludge collection ditch, realizing online removal of foam and sediment without stopping the machine to empty the entire tank of thawing liquid, thus avoiding interruption of continuous production. During the impurity removal process, the liquid replenishment control valve opens simultaneously to replenish the thawing tank with thawing fluid to maintain a stable liquid level and reduce the disturbance of the temperature field in the tank caused by liquid level fluctuations. In conjunction with the temperature regulation unit, it can stably maintain a low-temperature thawing environment, effectively improving production continuity and thawing quality stability while continuously ensuring the cleanliness of the thawing fluid and reducing food safety risks.

[0008] Preferably, as an improvement, the sludge collection ditch includes a longitudinal main sludge collection ditch arranged along the length of the thawing pool and several transverse branch sludge collection ditches arranged along the width. Each transverse branch sludge collection ditch is connected to the longitudinal main sludge collection ditch, and the bottom of the thawing pool is inclined at 1°~2° towards the sludge collection ditch. The inclined slope of the pool bottom helps the sludge to converge into the sludge collection ditch, improving the sludge enrichment efficiency and facilitating centralized collection and discharge.

[0009] Preferably, as an improvement, an integrated grid baffle matching the shape of the ditch is provided directly above the slag collection ditch, and a telescopic drive component linked to the slag discharge valve is provided on the thawing tank. Under normal slag collection conditions, the grid baffle is raised, leaving a gap with the bottom of the tank for bottom flow to enter, preventing the aeration turbulence from stirring up the sludge in the ditch. During slag discharge, the grid baffle is lowered to cover the ditch inlet, and an open water inlet section is left at the end of the transverse branch slag collection ditch away from the main ditch, which can form a directional flushing water flow along the ditch. Through the dual-position switching of the grid baffle, it is possible to prevent the back-mixing of deposited sludge into the main water body during normal operation, and to form a directional water flow to thoroughly flush the ditch sediment during the slag discharge stage, improving the thoroughness of slag discharge and avoiding the formation of dead corners for siltation in the ditch.

[0010] Preferably, as an improvement, a foam collecting baffle is provided along the length of the thawing tank. The foam collecting baffle is located inside and parallel to the strip overflow port, forming a foam collecting zone between them. The top of the foam collecting baffle is 2mm to 5mm higher than the static working liquid surface, and the bottom has a communication gap with the bottom of the tank. The opening ratio of the aeration coil corresponding to the foam collecting zone is lower than that of the main thawing zone. By utilizing the liquid level fluctuation difference between the main thawing zone and the foam collecting zone, the foam flows unidirectionally over the foam collecting baffle with the wave crest and enters the foam collecting zone for enrichment, further improving the concentration of foam collection and increasing the amount of impurities removed in a single foam removal operation.

[0011] Preferably, as an improvement, two impurity removal tanks are provided, respectively located adjacent to each other on both sides of the thawing tank in the width direction. Each impurity removal tank is equipped with a strip-shaped overflow port and a drainage control valve. The opening ratio of the aeration coil gradually decreases from the middle to both sides along the width direction. The double-sided impurity removal layout can expand the foam collection coverage area, improve the overall impurity removal efficiency, and adapt to the configuration of large thawing tanks with wide specifications.

[0012] Preferably, as an improvement, the conveying unit includes a support frame that can slide vertically along the inner wall of the thawing tank, a mesh conveyor belt mounted on the support frame, and a lifting drive mechanism that drives the support frame to rise and fall. The side wall of the support frame has a first through-hole for liquid and air bubbles to pass through, and the surface of the mesh conveyor belt has a second through-hole for liquid and small particulate impurities to pass through. The lifting drive mechanism allows for flexible adjustment of the immersion depth of the mesh conveyor belt, adapting to the thawing process requirements of frozen meat of different thicknesses and types, avoiding incomplete thawing or over-soaking leading to nutrient loss, and improving the equipment's process adaptability.

[0013] Preferably, as an improvement, the temperature control unit includes a heat exchange component located within the thawing tank. This heat exchange component can be a heat exchange coil or an electric heating rod that circulates a high-temperature medium, used to stably maintain the thawing liquid temperature within a preset temperature range. This can compensate in real time for the temperature drop caused by the heat absorbed during the melting of frozen meat, ensuring a low-temperature preservation environment, inhibiting microbial growth, preserving the freshness and nutrients of the meat, while maintaining a stable thawing rate and ensuring controllable production rhythm.

[0014] This invention adopts the following technical solution: a low-temperature bubble thawing method, implemented based on the low-temperature bubble thawing conveying system described above, comprising the following steps: S1 Liquid level preparation: injecting thawing liquid into the thawing tank to the set static working liquid level, and replenishing the liquid replenishment tank with thawing liquid for later use; S2 Feeding and immersion: placing the frozen meat to be thawed on the mesh conveyor belt, adjusting the vertical height of the support frame to ensure the frozen meat is completely immersed in the thawing liquid; S3 Bubble thawing: starting the air compressor and continuously blowing compressed air into the bottom of the thawing tank through the aeration coil, utilizing rising bubbles to enhance heat exchange on the surface of the frozen meat. Simultaneously, the temperature of the thawing solution is maintained within a preset low-temperature range by the temperature regulation unit; S4 linkage impurity removal and reuse: the liquid surface ripple gradient formed by aeration is used to directionally enrich the liquid surface foam, and the bottom circulation is used to flush and enrich the bottom sediment; the slag discharge valve and liquid discharge control valve are opened at set intervals to discharge the enriched impurities, and the liquid replenishment control valve is opened simultaneously during the impurity removal process to replenish the thawing solution and maintain the stability of the liquid level in the tank; the impurity-containing thawing solution discharged into the impurity removal tank is filtered and recycled for reuse; S5 continuous discharge: the frozen meat is moved forward along the conveying direction by the mesh conveyor belt, and after completing the water bath thawing, it is lifted and output to the downstream processing process.

[0015] The principle and advantages of this solution are as follows: In practical applications, this thawing method achieves efficient low-temperature thawing by enhancing heat exchange through bubble turbulence. Combined with an online linkage impurity removal and synchronous liquid replenishment mechanism, it can continuously maintain the cleanliness of the thawing solution and the stability of the liquid level and temperature in the tank without stopping the machine. This enables continuous and standardized thawing production of frozen meat, effectively improving production efficiency and reducing equipment operation and maintenance costs while ensuring the freshness and food safety of the meat. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the low-temperature bubble defrosting conveyor system according to an embodiment of the present invention. The second through hole on the mesh conveyor belt is not shown. Figure 2 This is a schematic diagram of the impurity removal mechanism according to an embodiment of the present invention; Figure 3 for Figure 2 A cross-sectional schematic diagram of AA in the middle; Figure 4 for Figure 3 A cross-sectional view of BB, showing the grid baffle located at the bottom; Figure 5 for Figure 4 Enlarged schematic diagram of section C.

[0017] The reference numerals in the accompanying drawings of the instruction manual include: 1. Thawing tank; 2. Aeration unit; 21. Aeration coil; 22. Air supply pipeline; 3. Conveying unit; 31. Support frame; 32. Mesh conveyor belt; 33. Lifting drive mechanism; 4. Temperature regulation unit; 5. Impurity removal mechanism; 51. Impurity removal tank; 52. Liquid replenishment tank; 6. Foam removal component; 61. Strip overflow port; 62. Drain pipe; 63. Drain control valve; 64. Foam collection baffle; 641. Foam collection area; 7. Sludge removal component; 71. Sludge collection ditch; 711. Main sludge collection ditch; 712. Branch sludge collection ditch; 72. Sludge discharge valve; 8. Grid baffle; 81. Telescopic drive component; 82. Water inlet section. Detailed Implementation

[0018] The following detailed description illustrates the specific implementation method: The basic implementation examples are as follows: Figure 1 As shown: A low-temperature bubble thawing and conveying system is mainly used for continuous low-temperature thawing of frozen meat and frozen food. The whole system includes a thawing tank 1, an aeration unit 2, a temperature regulation unit 4, a conveying unit 3, and a cleaning mechanism 5.

[0019] Reference Figure 2The thawing tank 1 is a long, open-topped trough, typically made of food-grade stainless steel, used to hold the thawing liquid and provide space for thawing operations. The aeration unit 2 includes the aforementioned air compressor and multiple aeration coils 21. These coils are arranged parallel to each other along the width of the thawing tank 1 at the bottom of the tank. The air inlet of each coil is connected to the air supply pipe 22, which in turn connects to the air outlet of the air compressor. During operation, compressed air generated by the air compressor is delivered to each aeration coil 21 via the air supply pipe 22. The air then blows upwards through the air outlet holes on the side wall of the coil, creating numerous fine, rising bubbles. This creates turbulent water flow that washes over the surface of the frozen meat, accelerating the melting of the ice.

[0020] Reference Figure 2 The temperature control unit 4 includes heat exchange components installed in the thawing tank 1 and supporting temperature detection and control elements. The heat exchange components can adopt a heat exchange coil structure, which exchanges heat with the thawing liquid by introducing a high-temperature medium to supplement the liquid with heat; or they can adopt an electric heating rod structure to directly heat the thawing liquid. The temperature detection element monitors the temperature of the thawing liquid in the tank in real time. When the temperature reaches the preset thawing temperature range, the control unit adjusts the heat exchange power of the heat exchange components to stably maintain the temperature of the thawing liquid within the specified thawing temperature range. The preset thawing temperature in this application is 15-18℃. This temperature range can ensure that the frozen meat is in a low-temperature preservation environment during the thawing process, inhibiting the growth of microorganisms and better preserving the freshness and nutritional quality of the meat. It can also avoid the thawing rate from decreasing and the thawing cycle from being too low, thus ensuring the stability of the overall thawing effect and production efficiency.

[0021] Reference Figure 1 The conveying unit 3 is used to carry frozen meat and realize continuous conveying and lifting discharge. It mainly includes a support frame 31, a mesh conveyor belt 32, and a lifting drive mechanism 33. The support frame 31 is erected in the thawing tank 1 and can slide vertically along the inner wall of the tank. The side wall of the support frame 31 has multiple first through holes. The size of the first through holes allows thawing liquid, air bubbles, and foam to pass through, but can block large-volume frozen meat from passing through, preventing material from falling from the side of the frame. The mesh conveyor belt 32 is installed on the support frame 31 and is driven by an independent drive motor through a sprocket and chain mechanism to circulate. The belt surface of the mesh conveyor belt 32 has multiple second through holes. The size of the second through holes allows thawing liquid, air bubbles, and small particle sediment to pass through, but can block the frozen meat to be thawed from passing through. This ensures that air bubbles and thawing liquid fully contact the surface of the frozen meat, and also allows small particle impurities that fall off to pass through the belt surface and settle to the bottom of the tank. The mesh conveyor belt 32 consists of a horizontal section and an lifting section. The horizontal section ensures that the frozen meat is in the thawing tank 1, while the lifting section facilitates the transportation of the thawed meat out of the thawing tank 1. The outlet of the lifting section is higher and extends to the outside of the discharge side of the thawing tank 1. During operation, the frozen meat is placed at the inlet end of the mesh conveyor belt 32 and gradually moves towards the lifting end as the mesh conveyor belt 32 runs. After completing the water bath thawing, it is lifted from the lifting section and falls to the downstream conveying equipment to enter the next process.

[0022] Reference Figure 1 The lifting drive mechanism 33 is installed on the upper frame of the thawing tank 1. Its output end is connected to the support frame 31, which drives the support frame 31 to move vertically up and down, thereby adjusting the overall height of the mesh conveyor belt 32 and changing the depth of the frozen meat immersed in the thawing liquid. Through lifting adjustment, the immersion depth of the frozen meat can be flexibly adjusted according to the thickness, type, and thawing process requirements of the frozen meat to be thawed. This ensures that the frozen meat is completely immersed in the thawing liquid, ensuring uniform thawing, while avoiding over-soaking that causes nutrient loss in the meat, thus improving the equipment's adaptability to materials of different specifications. In practical applications, the lifting drive mechanism 33 can adopt a variety of mature drive configurations, such as multiple sets of screw synchronous lifting mechanisms or multiple sets of chain lifting mechanisms.

[0023] Reference Figure 2 and Figure 3 The impurity removal mechanism 5 is used to remove some of the surface foam and bottom sediment generated during the thawing process online, maintaining the cleanliness of the thawing liquid. It mainly includes an impurity removal tank 51, a foam removal component 6, a sediment removal component 7, and a replenishment tank 52. The impurity removal tank 51 is located adjacent to one side of the thawing tank 1. The tank is equipped with a filter component for filtering and recovering the discharged thawing liquid containing impurities.

[0024] Reference Figure 2 and Figure 4 The foam removal component 6 is located on the upper part of the side wall of the thawing tank 1 near the impurity removal tank 51, and includes a strip-shaped overflow port 61, a drain pipe 62, and a drain control valve 63. The strip-shaped overflow port 61 is an elongated opening extending along the length of the thawing tank 1, located on the upper part of the side wall of the thawing tank 1. Its bottom edge is lower than the static working liquid level of the thawing tank 1, and its top edge is not lower than the static working liquid level. One end of the drain pipe 62 is connected to the outside of the strip-shaped overflow port 61, and the other end enters the impurity removal tank 51. The drain control valve 63 is installed on the drain pipe 62 to control the opening and closing of the pipeline. When the drain control valve 63 is closed, the drain pipe 62 is cut off, and the liquid in the thawing tank 1 cannot flow out, and the liquid level remains at the static working liquid level. When the drain control valve 63 is opened, the surface thawing liquid with the liquid level above the bottom edge of the strip overflow port 61, together with the accumulated foam, is discharged into the impurity removal tank 51 through the overflow port and drain pipe 62. When the liquid level drops below the bottom edge of the overflow port, the surface liquid no longer flows out, completing one foam discharge cycle. In order to improve the foam removal effect, when the drain control valve 63 is opened, its replenishment control valve is opened by 20% to increase the foam removal time.

[0025] Reference Figure 4To improve the foam accumulation effect, a foam collecting baffle 64 is installed in the thawing tank 1. The length direction of the foam collecting baffle 64 is parallel to the length direction of the thawing tank 1. The foam collecting baffle 64 is located inside the strip overflow port 61 and is arranged parallel to the overflow port, forming an independent foam collecting area 641 between the two. The top of the foam collecting baffle 64 is 2-5mm higher than the static working liquid surface, and a gap is left between the bottom of the baffle 64 and the bottom of the tank to keep the foam collecting area 641 in communication with the lower water of the main thawing area.

[0026] Reference Figure 4 Based on the layout of the foam collection zone 641 and the strip overflow port 61, the opening ratio of the air outlet of the aeration coil 21 along the width direction of the thawing tank 1 is distributed in a gradient, gradually decreasing from the side away from the strip overflow port 61 to the side closer to the strip overflow port 61, and the opening ratio of the aeration coil 21 below the foam collection zone 641 is lower than the opening ratio of the coil below the main thawing zone. The open area design results in differences in aeration intensity in different areas along the width of the pool. The surface fluctuation amplitude in the main thawing zone is greater than that in the foam collection zone 641, creating a surface fluctuation difference between the two zones. During normal aeration, the surface peaks in the main thawing zone can continuously overflow the top of the foam collection baffle 64 and enter the foam collection zone 641. After the foam enters the foam collection zone 641 with the surface liquid, it is difficult for the foam to flow back due to the gentle surface fluctuation in this zone, thus achieving continuous foam accumulation. At the same time, the overall surface fluctuation gradient can drive the foam to migrate and gather directionally towards one side of the strip overflow port 61, achieving directional foam aggregation without the need for additional foam scraping devices.

[0027] Reference Figure 4 Furthermore, when the thawing tank 1 is wide and adopts a double-sided impurity removal tank 51 structure, the opening rate of the air outlet in the aeration pipe along the width direction of the thawing tank 1 is symmetrically gradient distributed, gradually decreasing from the middle of the thawing tank 1 towards the side closer to the two sets of strip overflow ports 61; this causes the liquid surface fluctuations generated by aeration to gradually decrease from the middle to both sides, and the foam migrates and accumulates synchronously towards the strip overflow ports 61 on both sides; during the impurity removal operation, the liquid discharge control valves 63 on both sides open synchronously, respectively discharging foam and removing impurities into the corresponding impurity removal tank 51. The slag discharge and liquid replenishment logic is consistent with the single-sided structure, which can further improve the impurity removal efficiency of large equipment.

[0028] Reference Figure 2 and Figure 3The sludge removal component 7 is located at the bottom of the thawing tank 1 and includes a sludge collection ditch 71 and a sludge discharge valve 72. The sludge collection ditch 71 is positioned in the gap between adjacent aeration coils 21 to collect sludge collected by the circulating flow at the bottom of the tank. The sludge discharge valve 72 is installed at the lowest point of the sludge collection ditch 71, and its outlet is connected to the impurity removal tank 51 via a pipeline. During aeration, the air bubbles drive the water to form a continuous circulating flow at the bottom of the tank, gradually flushing and enriching the scattered meat scraps, bone fragments, and other sludge into the sludge collection ditch 71. When the sludge accumulates to a certain amount, the sludge discharge valve 72 is opened, and the sludge in the ditch, along with some thawing liquid, is discharged into the impurity removal tank 51 through the sludge discharge valve 72, achieving online discharge of the sludge.

[0029] Reference Figure 3 Furthermore, the slag collection ditch 71 includes a longitudinal main slag collection ditch 711 and multiple transverse branch slag collection ditches 712. The longitudinal main slag collection ditch 711 is arranged along the length of the thawing tank 1 in the middle of the tank bottom, and each transverse branch slag collection ditch 712 is arranged along the width of the thawing tank 1, corresponding to each other below the gap between adjacent aeration coils 21, and each transverse branch slag collection ditch 712 is connected to the longitudinal main slag collection ditch 711. The bottom of the thawing tank 1 is inclined towards the slag collection ditch 71 by an angle of 1° to 2°, so that the water and sediment at the bottom of the tank tend to flow towards the slag collection ditch 71, assisting in the sediment collection. In order to improve the collection effect, the multiple transverse branch slag collection ditches 712 are inclined towards the longitudinal main slag collection ditch 711, while the longitudinal main slag collection ditch 711 is inclined towards the slag discharge valve 72, so that the sediment in the slag collection ditch 71 tends to flow towards the slag discharge valve 72; at the same time, the slag collection ditch 71 has a structure with a small opening and a large interior.

[0030] Reference Figure 3 and Figure 5 Above the longitudinal main slag collection ditch 711 and the transverse branch slag collection ditch 712, there is an integrated grid baffle 8 that matches the shape of the ditch. A telescopic drive component 81 is installed on the side wall of the thawing tank 1. The output end of the telescopic drive component 81 is connected to the grid baffle 8, and the telescopic drive component 81 is linked to the slag discharge valve 72. Under normal slag collection conditions, the telescopic drive component 81 drives the grid baffle 8 to lift up. A gap is left between the grid baffle 8 and the bottom of the tank for the bottom flow to enter. This allows the bottom water carrying sediment to enter the slag collection ditch 71, while preventing the aeration turbulence from directly rushing into the ditch and stirring up the deposited sediment, thus preventing the sediment from being redispersed in the main thawing zone. When the slag discharge valve 72 is opened to discharge slag, the telescopic drive component 81 simultaneously drives the grid baffle 8 to descend, so that the grid baffle 8 is in the lower position, covering the upper inlet of the slag collection ditch 71. At the same time, each transverse branch slag collection ditch 712 has an open water inlet section 82 at the end away from the longitudinal main slag collection ditch 711. At this time, the thawing liquid in the pool rushes into the ditch from the open water inlet section 82, forming a directional flushing water flow along the transverse branch slag collection ditch 712 to the main slag collection ditch 711 and then to the slag discharge valve 72, thoroughly flushing out the sediment deposited in the ditch, improving the thoroughness of slag discharge and avoiding siltation in the ditch.

[0031] Reference Figure 4 The filter assembly within the impurity removal tank 51 employs a detachable, multi-stage stainless steel filter structure, consisting of a coarse filter layer and a fine filter layer from top to bottom. The coarse filter layer has larger pore sizes to intercept large particles such as meat scraps and bone fragments, while the fine filter layer has smaller pore sizes to intercept smaller impurities such as protein particles and fat particles. The impurity-laden thawing fluid discharged into the impurity removal tank 51 is filtered through these two stages to remove solid impurities. The filtered clean thawing fluid can be recycled and reused, reducing thawing fluid consumption. The detachable filter assembly facilitates periodic removal and cleaning of trapped impurities, making maintenance convenient.

[0032] Reference Figure 1 The replenishment tank 52 is located on the side of the thawing pool 1 and is used to store clean, ready-to-use thawing solution. The replenishment tank 52 is connected to the thawing pool 1 via a replenishment pipeline with a replenishment control valve. The aforementioned slag discharge valve 72 and liquid discharge control valve 63 are both linked to the replenishment control valve. When the slag discharge valve 72 is opened to discharge slag or the liquid discharge control valve 63 is opened to discharge foam, the replenishment control valve opens simultaneously. The ready-to-use thawing solution in the replenishment tank 52 is replenished into the thawing pool 1 through the replenishment pipeline to compensate for the volume of liquid discharged during the impurity removal process, so as to keep the liquid level in the pool stable and avoid the frozen meat being exposed on the surface due to the drop in liquid level, which would affect the uniformity of thawing. At the same time, it reduces the disturbance of the temperature field in the pool caused by liquid level fluctuations and ensures the stability of the low-temperature constant-temperature thawing environment. When the liquid discharge control valve 63 is opened, its replenishment control valve replenishes the thawing solution at a small flow rate for a long time, which facilitates the discharge of foam on the surface of the thawing pool 1.

[0033] Reference Figures 1-5 Based on the above-mentioned low-temperature bubble defrosting and conveying system, this embodiment also provides a low-temperature bubble defrosting method, the specific steps of which are as follows: S1 Preliminary Preparations and Liquid Level Adjustment Inject clean thawing fluid into thawing tank 1; simultaneously replenish sufficient standby thawing fluid into replenishment tank 52. The standby thawing fluid should be pre-adjusted to a temperature close to the working fluid level to reduce disturbance to the temperature field within the tank during replenishment. Check that the multi-stage filter assembly in the impurity removal tank 51 is installed in place, and that all control valves, aeration coils 21, and conveying units 3 are in their initial standby state. The temperature adjustment unit 4 can be pre-activated according to process requirements to pre-adjust the thawing fluid in the tank to the set low-temperature range, preparing for the thawing of incoming materials.

[0034] S2 Feeding and Immersion Depth Adjustment The frozen meat to be thawed is evenly spread on the feed end of the mesh conveyor belt 32 to avoid stacking, which would affect the uniformity of thawing. Based on the thickness, type, and corresponding process requirements of the frozen meat, the lifting drive mechanism 33 is activated, causing the support frame 31 to slide vertically along the inner wall of the tank. This adjusts the depth of the liquid level in the horizontal section of the mesh conveyor belt 32, ensuring the frozen meat is completely immersed in the thawing liquid while preventing excessive immersion and loss of nutrients. The liquid level is then adjusted until it reaches the preset static working liquid level. During adjustment, the first through-hole on the side wall of the support frame 31 ensures free flow of the thawing liquid within the tank, preventing significant surface fluctuations as the frame rises and falls, and also preventing the frozen meat from slipping off the side of the frame.

[0035] S3 Bubble Thawing and Constant Temperature Control The air compressor is started, and compressed air is sent to each aeration coil 21 through the air supply line 22. The defrosting liquid is continuously blown upward through the air outlet on the side wall of the aeration coil 21, forming a large number of fine rising bubbles. The bubbles drive the water to generate turbulence, continuously washing the surface of the frozen meat, enhancing the heat exchange between the frozen meat and the defrosting liquid, and accelerating the melting rate of the ice layer. Because the aeration coil 21 has a gradient of openings along its width, a undulating gradient is formed on the liquid surface in the pool, which gradually decreases from the strong aeration zone to the weak aeration zone. At the same time, a bottom flow circulation is formed at the bottom of the pool along the lateral direction.

[0036] During the thawing process, the melting of the ice layer on the frozen meat continuously absorbs heat, causing the temperature of the thawing solution to gradually decrease. Temperature detection elements monitor the liquid temperature in the tank in real time. When the temperature falls below the lower limit of the set range, the control unit activates the heat exchange components, using heat exchange coils or electric heating rods to compensate for the thawing solution's temperature, maintaining it stably within a preset range below 18°C. This temperature range maintains a low-temperature preservation environment, inhibiting microbial growth and maximizing the preservation of the meat's freshness and nutrients. Furthermore, it prevents excessively low temperatures from drastically reducing the thawing rate, ensuring a stable production cycle.

[0037] During this stage, the floating foam on the liquid surface gradually migrates towards the strip overflow outlet 61 with the liquid surface fluctuation gradient, and through the liquid surface fluctuation difference between the main thawing zone and the foam collection zone 641, it flows over the foam collection baffle 64 with the wave crest and enters the foam collection zone 641 for enrichment; the sludge such as meat scraps and bone fragments that fall off the bottom of the pool are gradually washed into the horizontal branch sludge collection ditches 71 by the bottom flow circulation, and then flow into the longitudinal main sludge collection ditches 71 for storage along the inclined channels. Under normal sludge collection conditions, the grid baffle 8 is in the raised position, which allows the bottom flow carrying sludge to flow into the channel, and also prevents the aeration turbulence from stirring up the sludge that has been deposited in the ditch, thus avoiding the redispersal of impurities.

[0038] S4 linkage impurity removal and liquid level compensation After the equipment has been running continuously for a set period of time, the impurity removal program is automatically triggered, and the foam removal and slag removal operations are performed in sequence. When foam removal is performed, the control system opens the drain control valve 63, and the foam accumulated in the foam collection area 641, together with the surface thawing liquid, flows into the drain pipe 62 through the strip overflow port 61, and is finally discharged into the impurity removal tank 51; when the liquid level in the tank drops to the bottom edge of the strip overflow port 61, the surface liquid no longer flows out, and the drain control valve 63 automatically closes after being opened for a specified period of time, completing one foam removal operation. During sludge discharge, the telescopic drive 81 and the sludge discharge valve 72 operate in conjunction: the telescopic drive 81 first lowers the grid baffle 8, covering the upper inlets of the transverse branch sludge collection ditch 71 and the longitudinal main sludge collection ditch 71, leaving only the open water inlet section 82 of each transverse branch sludge collection ditch 71 away from the main ditch; then the sludge discharge valve 72 opens, and the thawing liquid rushes into the ditch from the open water inlet section 82, forming a directional flushing water flow along the transverse branch sludge collection ditch 71 to the longitudinal main sludge collection ditch 71, and then to the sludge discharge valve 72, thoroughly flushing out the sludge deposited in the ditch, which is then discharged into the impurity removal tank 51 along with the thawing liquid. After sludge discharge is completed, the sludge discharge valve 72 closes, and the grid baffle 8 simultaneously resets and rises, restoring normal sludge collection. Throughout the foam and slag removal process, the replenishment control valve can be opened, and the standby thawing fluid in the replenishment tank 52 is continuously replenished into the thawing pool 1 through the replenishment pipeline. This compensates for the volume of liquid discharged during the impurity removal process, keeping the liquid level in the pool within a stable range. This prevents frozen meat from being exposed above the liquid surface, which would affect the thawing effect, and also reduces temperature field disturbances caused by liquid level fluctuations. The impurity-laden thawing fluid discharged into the impurity removal tank 51 passes through a multi-stage filtration assembly from top to bottom. First, it passes through a coarse filter layer to intercept large particles such as meat scraps and bone fragments, and then through a fine filter layer to intercept fine impurities such as protein particles and fat particles. The filtered clean thawing fluid can be recycled back to the replenishment system for reuse, reducing production water and energy costs. The filter assembly can be removed and cleaned periodically, making maintenance simple.

[0039] S5 continuously improves discharge After the thawing process is completed, the mesh conveyor belt 32 maintains a low-speed continuous operation. The frozen meat first passes through the horizontal section, where it undergoes full thawing in a water bath environment. It then enters the upward-sloping lifting section, gradually rising and detaching from the thawing liquid surface. Finally, it slides down from the end of the lifting section to the downstream output conveyor, continuously feeding it into the next processing step. This entire process enables continuous production with simultaneous feeding, thawing, impurity removal, and discharge. Impurity removal does not require stopping the machine to drain the entire thawing liquid tank, thus maintaining the production cycle. While ensuring thawing quality and food hygiene, this significantly improves production continuity and operational efficiency.

[0040] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A low-temperature bubble thawing and conveying system, comprising a thawing tank (1), an aeration unit (2), a temperature regulating unit (4), and a conveying unit (3); characterized in that: It also includes a cleaning mechanism (5), which includes: A cleaning tank (51) is located adjacent to the thawing tank (1) on one side, and a filter assembly is provided therein; A foam removal component (6) is installed on the thawing tank (1). The foam removal component (6) includes a strip-shaped overflow port (61) opened on the upper side wall of the thawing tank (1), a drain pipe (62) connecting the strip-shaped overflow port (61) and the impurity removal tank (51), and a drain control valve (63) installed on the drain pipe (62). When the drain control valve (63) is closed, it cuts off the drain pipe (62). When it is open, it makes the liquid level higher than the bottom edge of the strip-shaped overflow port (61). The surface thawing liquid is discharged into the impurity removal tank (51) through the strip overflow port (61) and the drain pipe (62); the aeration unit (2) includes an air compressor and multiple aeration coils (21). The opening ratio of the aeration coils (21) along the width direction of the thawing tank (1) decreases gradually from the side away from the strip overflow port (61) to the side closer to the strip overflow port (61) to form a liquid surface fluctuation gradient, driving the surface foam to migrate and gather in a directional manner towards the side of the strip overflow port (61); The sludge removal component (7) is installed at the bottom of the thawing tank (1). The sludge removal component (7) includes a sludge collection ditch (71) located at the bottom of the thawing tank (1) and corresponding to the gap of the aeration coil (21), and a sludge discharge valve (72) located at the lowest point of the sludge collection ditch (71). The bottom circulation formed by aeration can wash and enrich the sludge in the sludge collection ditch (71). The outlet of the sludge discharge valve (72) is connected to the impurity removal tank (51). The replenishment tank (52) is set on the thawing pool (1) and connected to the thawing pool (1) through a replenishment pipeline with a replenishment control valve. The slag discharge valve (72) and the liquid discharge control valve (63) are both linked with the replenishment control valve so as to replenish the thawing liquid into the thawing pool (1) simultaneously when discharging slag or foam.

2. The low-temperature bubble defrosting and conveying system according to claim 1, characterized in that: The slag collection ditch (71) includes a longitudinal main slag collection ditch (711) and several transverse branch slag collection ditches (712); the longitudinal main slag collection ditch (711) is arranged along the length of the thawing pool (1) on the side of the pool bottom near the impurity removal trough (51), and the transverse branch slag collection ditches (712) are arranged one-to-one in the width of the thawing pool (1) below the gap between two adjacent aeration coils (21), and each transverse branch slag collection ditch (712) is connected to the longitudinal main slag collection ditch (711); the bottom of the thawing pool (1) is inclined towards the slag collection ditch (71) at an angle of 1°~2°.

3. The low-temperature bubble defrosting and conveying system according to claim 2, characterized in that: Above the longitudinal main slag collection ditch (71) and the transverse branch slag collection ditch (71), an integrated grid baffle (8) matching the shape of the ditch is provided. The thawing tank (1) is equipped with a telescopic drive (81), which is linked to the slag discharge valve (72). Under normal slag collection conditions, the telescopic drive (81) drives the grid baffle (8) to lift, leaving a gap between the grid baffle (8) and the bottom of the tank for horizontal bottom flow to converge. The turbulent flow of air bubbles can be blocked, which can cause sediment to be stirred up in the ditch. When the slag discharge valve (72) is opened, the telescopic drive (81) drives the grid baffle (8) to descend and cover the inlet of the slag collection ditch (71). Each horizontal branch slag collection ditch (71) has an open water inlet section (82) at the end away from the longitudinal main slag collection ditch (71). The thawing liquid in the tank is flushed into the ditch from the open water inlet section (82), forming a directional flushing water flow that flows along the branch ditch to the main slag collection ditch (71) and then to the slag discharge valve (72).

4. The low-temperature bubble defrosting and conveying system according to claim 1, characterized in that: A foam collecting baffle (64) is provided along the length of the thawing tank (1). The foam collecting baffle (64) is located inside the strip overflow port (61) and is parallel to the strip overflow port (61), forming a foam collecting area (641) between the two. The top of the foam collecting baffle (64) is 2mm to 5mm higher than the static working liquid surface, and the bottom is connected to the bottom of the thawing tank (1). The opening rate of the aeration coil (21) corresponding to the foam collecting area (641) is lower than that of the aeration coil (21) corresponding to the main thawing area, so that the two areas form a liquid surface fluctuation difference. The foam in the main thawing area can flow unidirectionally over the foam collecting baffle (64) with the wave crest and enter the foam collecting area (641) for enrichment.

5. A low-temperature bubble defrosting and conveying system according to claim 4, characterized in that: The strip-shaped overflow port (61) is a long strip-shaped opening extending along the length of the thawing tank (1). Its bottom edge is lower than the static working liquid level of the thawing tank (1), and its top edge is not lower than the static working liquid level of the thawing tank (1). When the drain control valve (63) is closed, the drain pipe (62) is cut off. When the drain control valve (63) is opened, the foam accumulated in the foam collection area (641) along with the surface thawing liquid is discharged into the impurity removal tank (51) through the strip-shaped overflow port (61) and the drain pipe (62) until the liquid level drops below the bottom edge of the strip-shaped overflow port (61) and the drain stops.

6. The low-temperature bubble defrosting and conveying system according to claim 1, characterized in that: There are two impurity removal tanks (51), which are respectively located on both sides of the width direction of the thawing tank (1); The thawing tank (1) has strip-shaped overflow ports (61) on both opposite sides of the wall. Each strip-shaped overflow port (61) is connected to the corresponding impurity removal tank (51) through the drain pipe (62). Each drain pipe (62) is equipped with a drain control valve (63). The opening ratio of the aeration coil (21) along the width direction of the thawing tank (1) gradually decreases from the middle to the two sides of the strip overflow port (61), so that the fluctuation amplitude of the liquid surface gradually decreases from the middle to the two sides, driving the surface foam to migrate and accumulate in a directional manner from the middle to the two sides of the strip overflow port (61).

7. A low-temperature bubble defrosting and conveying system according to claim 1, characterized in that: The conveying unit (3) includes: The support frame (31) is vertically slidably disposed in the thawing pool (1), and its side wall is provided with a first through hole for the thawing liquid, air bubbles and foam to pass through; The mesh conveyor belt (32) is installed on the support frame (31) to carry frozen meat and realize the continuous conveying and lifting of frozen meat. The belt surface is provided with a second through hole for thawing liquid, air bubbles and small particle sediment to pass through. A lifting drive mechanism (33) is installed on the thawing pool (1) and connected to the support frame (31) to drive the support frame (31) to lift and lower, so as to adjust the depth of the frozen meat immersed in the thawing liquid; The first through-hole allows thawing fluid, air bubbles, and foam to pass through while preventing large volumes of meat from passing through, while the second through-hole allows thawing fluid, air bubbles, and small particles of sediment to pass through while preventing frozen meat from passing through.

8. A low-temperature bubble defrosting and conveying system according to claim 1, characterized in that: The temperature regulation unit (4) includes a heat exchange component installed in the thawing tank (1) for maintaining the temperature of the thawing liquid in the thawing tank (1) within a preset thawing temperature range.

9. A method for cryogenic bubble defrosting, implemented based on a cryogenic bubble defrosting conveying system according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1 Liquid level preparation: Inject thawing fluid into the thawing tank (1) to the set static working liquid level, and replenish the thawing fluid to be used into the replenishment tank (52); S2 Feeding and Soaking: Place the frozen meat to be thawed on the mesh conveyor belt (32), and drive the support frame (31) to rise and fall through the lifting drive mechanism (33). Adjust the height of the mesh conveyor belt (32) so that the frozen meat is completely immersed in the thawing liquid. S3 Bubble thawing: Start the air compressor and continuously blow compressed air into the bottom of the thawing tank (1) through the aeration coil (21) to form rising bubbles to enhance the heat exchange on the surface of the frozen meat. At the same time, the temperature of the thawing liquid in the thawing tank (1) is maintained within the preset thawing temperature range through the temperature regulation unit (4). S4 linkage impurity removal and reuse: Under normal operating conditions, the periodic fluctuation of the liquid surface generated by aeration drives the surface foam to flow over the foam collection baffle (64) and enter the foam collection area (641) with the thawing liquid. The bottom circulation formed by aeration washes and enriches the sediment in the sludge collection ditch (71). The sludge discharge valve (72) is opened at set intervals to discharge the sediment enriched in the sludge collection ditch (71) into the impurity removal tank (51). The liquid discharge control valve (63) is opened so that the foam enriched in the foam collection area (641) along with the surface thawing liquid is discharged into the impurity removal tank (51) through the strip overflow port (61) and the liquid discharge pipe (62). During the sludge discharge or foam discharge process, the liquid replenishment control valve is opened simultaneously to replenish the thawing tank (1) from the liquid replenishment tank (52) to compensate for the liquid level in the thawing tank (1). S5 Continuous discharge: After thawing, the mesh conveyor belt (32) continues to run, driving the frozen meat forward along the conveying direction and finally conveying it to the downstream processing process.

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