A high-pressure pickling-energy-saving quick-freezing device and method below the freezing point of aquatic products

Abstract

The present invention discloses a high-pressure, energy-saving, quick-freezing device and method for aquatic products, which is below their freezing point. The device comprises a barrier ring plate, a high-pressure curing tank, an ice crystal generation positioning rod, a curing basket, a curing liquid storage tank, a pressure relief pipe, a feed pump, a curing liquid inspection pipe, a feed pipe, and a heating coil. By regulating the freezing point of the curing liquid and separating it, the device controls ice crystal formation in the curing liquid and the aquatic product. Furthermore, the device utilizes the pressure generated by the expansion of ice crystals in the curing liquid to achieve high-pressure, efficient curing of aquatic products below their freezing point at ambient pressure, while also enabling rapid freezing of the aquatic products after high-pressure curing.

Description

Technical Field

[0001] The present invention relates to the technical field of pickling and quick-freezing of aquatic products, and in particular to a high-pressure pickling-energy-saving quick-freezing method at a temperature lower than the freezing point of aquatic products. Background Art

[0002] Fish is rich in nutrients such as protein, unsaturated fatty acids, and various trace elements. However, fish has a high water content. If not processed promptly, it can easily undergo chemical reactions such as protein decomposition and fat oxidation under the action of microorganisms and enzymes, ultimately causing the fish to spoil.

[0003] Curing is a common method for processing and preserving aquatic products, extending their shelf life, improving flavor, and enhancing their quality. Dry curing and wet curing are common methods. Dry curing can easily lead to protein and fat oxidation and microbial growth, while wet curing can be uneven and slow. While tumbling can accelerate curing, the external forces applied during tumbling can easily disrupt the original shape of the food, making it unsuitable for curing aquatic products.

[0004] To prevent quality degradation during cold chain transportation, storage, and sales, frozen aquatic products are often used to inhibit microbial growth and slow chemical reactions, thereby extending their shelf life. Freezing can be categorized as slow freezing or rapid freezing, depending on the freezing rate. Slow freezing causes ice crystals to form within the cells, causing varying degrees of damage to the fish. However, rapid freezing prevents the water within the cells from osmosis, allowing them to form tiny ice crystals within the cells, minimizing damage. Summary of the Invention

[0005] The purpose of the present invention is to solve the above-mentioned technical problems and provide a high-pressure, high-efficiency, and energy-saving quick-freezing method for aquatic products at a temperature below the freezing point. The present invention controls the formation of ice crystals in the pickling liquid and the aquatic products by adjusting the freezing point of the pickling liquid and separating the pickling liquid, and then utilizes the pressure generated by the expansion of ice crystals formed by the pickling liquid. On the one hand, it realizes high-pressure and high-efficiency pickling of aquatic products at a temperature below their freezing point at normal pressure, and on the other hand, it can realize rapid freezing of aquatic products after high-pressure pickling.

[0006] The present invention is achieved through the following technical solutions.

[0007] In one aspect, the present invention provides a high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products, characterized by comprising:

[0008] A high-pressure pickling tank, wherein the peripheral side tank wall of the high-pressure pickling tank is provided with a refrigerant delivery cavity for circulating refrigerant liquid from bottom to top, and a tank opening is provided at the center of the top tank wall of the high-pressure pickling tank, and a detachable sealing cover on the tank opening is closed with a tank cover;

[0009] A pickling basket, which is detachably arranged in a high-pressure pickling tank;

[0010] A barrier ring plate, which surrounds the pickling basket and is disposed in the high-pressure pickling tank, with an upper end of the barrier ring plate engaging with the tank opening and a lower end of the barrier ring plate being sealed to the bottom of the high-pressure pickling tank. A plurality of flow holes are provided in an annular direction on the upper end of the barrier ring plate;

[0011] A heating coil is spirally arranged between the inner wall of the barrier ring plate and the pickling basket, and is used to input heating medium from bottom to top into the heating coil to heat the pickling liquid in the barrier ring plate;

[0012] An ice crystal formation positioning rod is disposed between the outer wall of the barrier ring plate and the inner wall of the high-pressure pickling tank and is located at the bottom of the high-pressure pickling tank. When the pickling liquid drops below the freezing point, the pickling liquid first forms crystal nuclei near the ice crystal formation positioning rod and grows into ice crystals.

[0013] pickling liquid storage tank;

[0014] A feeding pipe, wherein the discharge port of the feeding pipe is connected to the top of the high-pressure pickling tank, the feed port is connected to the bottom of the pickling liquid storage tank, and a feeding valve is provided at one end of the feeding pipe near the discharge port;

[0015] A feeding pump, the feeding pump is arranged on one end of the feeding pipe close to the feeding port;

[0016] A pickling liquid inspection pipe is provided on the top wall of the high-pressure pickling tank and is in communication with the interior of the high-pressure pickling tank to monitor whether the high-pressure pickling tank is full of pickling liquid, and a water stop valve is provided on the pickling liquid inspection pipe;

[0017] A pressure relief pipe, one end of which is connected to the bottom of the high-pressure pickling tank inside the barrier ring plate, and the other end is connected to the top of the pickling liquid storage tank, and a pressure relief valve is provided on the pressure relief pipe.

[0018] Preferably, the pickling basket can be placed in or taken out of the high-pressure pickling tank through the tank opening.

[0019] Preferably, an inner ring temperature sensor is provided on the tank cover, and an outer ring temperature sensor is provided on the side wall of the high-pressure pickling tank close to the ice crystal formation positioning rod.

[0020] Preferably, the ice crystal formation promoting component is a metal rod in the shape of a dendrite.

[0021] Preferably, the pickling basket includes a basket frame, a mesh surface covering the sides and bottom of the basket frame, and a plurality of partition plates detachably arranged in the basket frame.

[0022] Preferably, a safety valve and a pressure gauge for monitoring the internal pressure of the high-pressure pickling tank are provided on the top wall of the high-pressure pickling tank.

[0023] Preferably, a stirring assembly is provided in the pickling liquid storage tank, and a breathing valve is provided on the top of the pickling liquid storage tank.

[0024] Preferably, the lower end pipe mouth of the heating coil is connected to the feed pipe through a heating medium input pipe that passes through the bottom of the high-pressure pickling tank, and the upper end pipe mouth of the heating coil is connected to the top of the pickling liquid storage tank through a heating medium return pipe, and a heating medium input valve is provided on the heating medium input pipe.

[0025] Preferably, the tank wall of the high-pressure pickling tank is made of alloy steel and can withstand high pressure higher than 100 MPa.

[0026] In another aspect, the present invention provides a high-pressure pickling and energy-saving quick-freezing method at a temperature below the freezing point of aquatic products, characterized by comprising the following steps:

[0027] S1. Prepare the pickling liquid: Prepare the pickling liquid in a pickling liquid storage tank. The pickling liquid is composed of sodium chloride, glycerol, trehalose, a flavor adjustment component, and water. The freezing point of the pickling liquid at atmospheric pressure is controlled to be 2 to 3°C lower than the freezing point of the aquatic product at atmospheric pressure.

[0028] S2. Filling: The aquatic product to be pickled is placed in a pickling basket and transferred to a high-pressure pickling tank. Then, pickling liquid is added to the high-pressure pickling tank until the high-pressure pickling tank is filled with the pickling liquid, so that the pickling liquid and the aquatic product are contained in the high-pressure pickling tank in a sealed state with a constant volume.

[0029] S3. Low-temperature, high-pressure curing: A low-temperature refrigerant 3-5°C below the freezing point of the curing liquid at normal pressure is continuously circulated into the refrigerant circulation and delivery chamber to cool the material in the high-pressure curing tank. Crystal nuclei form in the curing liquid near the positioning rod in the high-pressure curing tank and grow into ice crystals. The ice crystals expand, increasing the pressure in the high-pressure curing tank, thereby lowering the freezing point of the aquatic product and the curing liquid. Ultimately, the curing liquid temperature reaches the same or close to that of the low-temperature refrigerant. The curing liquid in the high-pressure curing tank is in a state of equilibrium where solid and liquid coexist. At this point, the aquatic product is unfrozen and is cured in a high-pressure environment below its normal freezing point. In this step, the curing pressure and curing temperature can be adjusted by setting the refrigerant temperature, and the curing time can be controlled by the duration of the continuous refrigerant flow.

[0030] S4. Pressure relief and quick freezing: The temperature of the pickling liquid in the barrier ring plate is continuously and rapidly increased. When the temperature of the pickling liquid in the barrier ring plate reaches the freezing point of the pickling liquid at normal pressure, the temperature increase is stopped and the pressure relief valve is immediately opened. The pressure in the high-pressure pickling tank is released instantly. At this time, the temperature of the aquatic product is lower than its freezing point at normal pressure, and the aquatic product will freeze quickly. After that, the tank lid is opened to take out the frozen aquatic product.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] 1) During the low-temperature pickling process, the present invention utilizes the pickling liquid and the aquatic product in a cavity of constant volume. The pressure generated by the expansion of ice crystals in the pickling liquid is used to lower the freezing point of the aquatic product and the remaining pickling liquid, thereby achieving high-pressure pickling of the aquatic product below the normal freezing point. This improves pickling efficiency and maintains quality characteristics while inhibiting ice crystal growth.

[0033] 2) After the pickling is completed, the present invention uses the pickling liquid to discharge the cavity, so that the pressure in the cavity is rapidly reduced, and small and evenly distributed ice crystals can be quickly formed in the aquatic product, reducing the damage of the ice crystals to the pickled aquatic product tissue, thereby achieving rapid freezing and improving the freezing quality of the pickled aquatic product; moreover, during the pressure relief quick-freezing process, the pickling liquid in the barrier ring plate will not freeze, thereby preventing the pickling liquid in direct contact with the aquatic product from freezing and damaging the aquatic product, further improving the freezing quality of the pickled aquatic product.

[0034] 3) The present invention utilizes the pickling liquid in the pickling liquid storage tank as a heating medium and can simultaneously pre-cool the pickling liquid in the pickling liquid storage tank to achieve recycling of cold energy. At the same time, the instantaneous release of system pressure is utilized to achieve rapid freezing of aquatic products, thereby reducing energy consumption during the freezing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions of the present invention, the following briefly introduces the drawings required for use in some embodiments of the present invention. Obviously, the drawings described below are only drawings of some embodiments of the present invention, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below should be viewed as schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present invention.

[0036] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0037] Figure 2 It is a schematic diagram of the partial structure of the device of the present invention;

[0038] Figure 3 for Figure 1 Cross-section at AA in the middle;

[0039] Figure 4 A state diagram of the device of the present invention when in use;

[0040] The meanings of the symbols in the above figure are: barrier ring plate 1, flow hole 101, high-pressure pickling tank 2, tank mouth 201, tank cover 202, ring inner temperature sensor 203, ring outer temperature sensor 204, safety valve 205, pressure gauge 206, refrigerant delivery chamber 3, ice crystal generation positioning rod 4, pickling basket 5, basket frame 501, mesh surface 502, partition plate 503, pickling liquid storage tank 6, stirring assembly 601, breathing valve 602, pressure relief pipe 7, pressure relief valve 701, feeding pump 8, pickling liquid inspection pipe 9, water stop valve 901, feeding pipe 10, feeding valve 1001, heating coil 11, heating medium input pipe 1101, heating medium return pipe 1102, heating medium input valve 1103, ice crystal 12, pickling liquid 13, aquatic product 14. DETAILED DESCRIPTION

[0041] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments provided by the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0042] Example 1

[0043] A high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products, please refer to Figures 1 to 4 , which includes: a barrier ring plate 1, a high-pressure pickling tank 2, an ice crystal generation positioning rod 4, a pickling basket 5, a pickling liquid storage tank 6, a pressure relief pipe 7, a feed pump 8, a pickling liquid inspection pipe 9, a feed pipe 10, and a heating coil 11;

[0044] The high-pressure pickling tank 2 is a cylindrical tank body. The side wall of the high-pressure pickling tank 2 is provided with a refrigerant delivery chamber 3 for circulating the refrigerant from bottom to top. The refrigerant is cooled by a refrigerant circulation mechanism. The refrigerant temperature control range is -25 to -5 ° C. The refrigerant is delivered from the liquid inlet below the refrigerant delivery chamber 3 to the refrigerant delivery chamber 3 and then flows back from the liquid outlet above the refrigerant delivery chamber 3. A tank opening 201 is provided at the center of the top tank wall of the high-pressure pickling tank 2. A detachable sealing cover on the tank opening 201 is provided. The pickling basket 5 is detachably mounted in the high-pressure pickling tank 2. The barrier ring plate 1 surrounds the pickling basket 5 and is mounted in the high-pressure pickling tank 2. The upper end of the barrier ring plate 1 is connected to the tank opening 201, and the lower end is sealed to the bottom of the high-pressure pickling tank 2. The upper end of the barrier ring plate 1 is provided with a plurality of flow holes 101 along the annular direction. The heating coil 11 is spirally mounted between the inner wall of the barrier ring plate 11 and the pickling basket 5 to input the heating medium from the bottom to the top of the barrier ring plate 1. The pickling liquid in the ring is heated; the ice crystal generation positioning rod 4 is arranged between the outer wall of the barrier ring plate 1 and the inner wall of the high-pressure pickling tank 2 and is located at the bottom of the high-pressure pickling tank 2, so that when the pickling liquid drops below the freezing point, the pickling liquid first forms crystal nuclei near the position of the ice crystal generation positioning rod 4 and grows into ice crystals. In addition, the ice crystal generation positioning rod 4; the discharge port of the feed pipe 10 is connected to the top of the high-pressure pickling tank 2, the feed port is connected to the bottom of the pickling liquid storage tank 6, and the feed pipe 10 is set at one end near the discharge port. There is a feed valve 1001; the feed pump 8 is installed on the feed pipe 601 at one end near the feed inlet; the pickling liquid inspection pipe 9 is installed on the top tank wall of the high-pressure pickling tank 2 and is connected to the interior of the high-pressure pickling tank 2 to monitor whether the high-pressure pickling tank 2 is full of pickling liquid, and the pickling liquid inspection pipe 9 is provided with a water stop valve 901; one end of the pressure relief pipe 7 is connected to the bottom of the high-pressure pickling tank 2 inside the barrier ring plate 1, and the other end is connected to the top of the pickling liquid storage tank 6, and the pressure relief pipe 7 is provided with a pressure relief valve 701;

[0045] In the above structure, the pickling liquid and aquatic products in the high-pressure pickling tank 2 can be cooled by circulating the low-temperature refrigerant into the refrigerant delivery chamber 3; the pickling liquid and aquatic products in the barrier ring plate 1 can be heated by circulating the heating medium into the heating coil 11; since the barrier ring plate 1 is arranged around the pickling basket 5 and is arranged in the high-pressure pickling tank 2, the heat transfer efficiency of the pickling liquid between the inside and outside of the barrier ring plate 1 can be limited or reduced; when the pickling liquid and aquatic products in the high-pressure pickling tank 2 are cooled, the aquatic products are in the high-pressure pickling tank 2. The center position of the high-pressure pickling tank 2 is formed by the blocking effect of the blocking ring plate 1. Even if the freezing point of the pickling liquid at normal pressure is lower than the freezing point of the aquatic product at normal pressure, the pickling liquid outside the blocking ring plate 1 will reach the freezing point of normal pressure before the aquatic product inside the blocking ring plate 1. Therefore, the pickling liquid outside the blocking ring plate 1 will form ice crystals and freeze first. In addition, since the refrigerant delivery cavity 3 circulates the refrigerant from bottom to top, the temperature of the pickling liquid at the bottom of the high-pressure pickling tank 2 is lower. Then, at the position outside the blocking ring plate 1, the ice crystal generation positioning rod 4 will promote the pickling liquid to freeze in the ice crystals. Crystal nuclei are formed near the positioning rod 4 and grow into ice crystals, thereby increasing the pressure in the high-pressure chamber, lowering the freezing point of the marinade and the aquatic product, and thus inhibiting the formation of ice crystals in the remaining marinade and the aquatic product; when the marinade in the barrier ring plate 1 is heated, the temperature of the marinade outside the barrier ring plate 1 will slowly increase or increase slightly due to the barrier effect of the barrier ring plate 1, while the marinade in the barrier ring plate 1 can be quickly heated to the required temperature; the flow hole 101 can keep the inside and outside of the barrier ring plate 1 in communication The barrier ring plate 1 is kept in a state such that the pressure inside and outside the barrier ring plate 1 is the same. Furthermore, since the flow hole 101 is located at the top of the barrier ring plate 1, when the pressure relief valve 701 is opened to relieve pressure, the pickling liquid outside the ring cannot be replenished into the ring, thereby facilitating the drainage of residual pickling liquid on the aquatic products inside the ring. To limit or reduce the heat transfer efficiency of the pickling liquid between the inside and outside of the barrier ring plate 1, the barrier ring plate 1 can be reasonably selected in terms of its manufacturing material (e.g., using a heat-insulating material), dimensions (e.g., thickness of the barrier ring plate), and structure (e.g., providing a sealed cavity inside the barrier ring plate).

[0046] Based on the above structure, the method or principle of pickling and quick-freezing aquatic products using the device of the present invention is as follows:

[0047] S1. Prepare the pickling liquid: Prepare the pickling liquid in the pickling liquid storage tank 6 first, and control the freezing point temperature of the pickling liquid at normal pressure to be 2-3°C lower than the freezing point temperature of the aquatic product at normal pressure;

[0048] S2. Filling: Place the aquatic product to be pickled in the pickling basket 5, controlling the height of the aquatic product to be filled to 1 / 2 to 2 / 3 of the height of the high-pressure pickling tank 2. Then, place the pickling basket 5 into the high-pressure pickling tank 2 through the tank opening 201 and close the tank lid 202. First, check whether the pressure relief valve 701 is closed. Then, deliver the prepared pickling liquid into the high-pressure pickling tank 2 through the feed pump 8 and feed pipe 10. Monitor the high-pressure pickling tank 2 in real time using the pickling liquid inspection pipe 9 to see whether the high-pressure pickling tank 2 is full of pickling liquid. When the pickling liquid fills the high-pressure pickling tank 2, close the feed valve 1001, feed pump 8, and water stop valve 901 in sequence, so that the pickling liquid and the aquatic product are contained in the high-pressure pickling tank 2 in a sealed state with a constant volume.

[0049] S3. Low-temperature, high-pressure pickling: A low-temperature refrigerant 3-5°C below the freezing point of the pickling liquid at atmospheric pressure is continuously circulated into the refrigerant circulation and delivery chamber 3 to cool the pickling liquid and the aquatic product in the high-pressure pickling tank 2. Since the aquatic product is located at the center of the tank and is immersed in the pickling liquid, and under the blocking effect of the blocking ring plate 1, the pickling liquid reaches the freezing point at atmospheric pressure before the aquatic product. In addition, crystal nuclei are first formed and grow into ice crystals in the pickling liquid near the ice crystal formation positioning rod 4. The expansion of the ice crystals increases the pressure in the high-pressure pickling tank 2, thereby reducing the freezing point of the aquatic product and the pickling liquid to a temperature far below that of the low-temperature refrigerant. The pressure in the high-pressure pickling tank 2 remains stable. Eventually, the temperature of the pickling liquid and the aquatic product is the same as or close to that of the low-temperature refrigerant. Ice crystals no longer form, and the pickling liquid in the high-pressure pickling tank 2 is in a state of equilibrium where solid and liquid coexist. The aquatic product is pickled in a high-pressure environment with a temperature below its freezing point at atmospheric pressure, while remaining unfrozen.

[0050] S4. Pressure relief and quick freezing: When the marinating is completed, a heating medium with a temperature of 15-30°C can be input into the heating coil 11. The heating coil 11 continuously and rapidly heats the marinating liquid in the barrier ring plate 1. Due to the barrier effect of the barrier ring plate 1, the temperature of the marinating liquid outside the barrier ring plate 1 will rise slowly or with a small temperature increase. Therefore, the marinating liquid will still be in a state of equilibrium between solid and liquid coexistence, so that the pressure in the high-pressure marinating tank 2 remains basically unchanged; while the temperature of the marinating liquid and the aquatic product in the barrier ring plate 1 will rise rapidly. When the temperature of the marinating liquid in the barrier ring plate 1 rises to the freezing point of the marinating liquid at normal pressure, the input of the heating medium is stopped. The pressure relief valve 701 is immediately opened, and part of the pickling liquid in the barrier ring plate 1 is quickly discharged into the pickling liquid storage tank 6 through the pressure relief pipe 7, thereby achieving the following purposes: first, the pressure in the high-pressure pickling tank 2 is instantly released. Since the temperature of the aquatic product is lower than its freezing point at normal pressure at this time, the aquatic product will freeze quickly; second, the temperature of the pickling liquid in the barrier ring plate 1 is higher than its freezing point at normal pressure, and the pickling liquid in the barrier ring plate 1 will not freeze. A part of it will be discharged into the pickling liquid storage tank 6, thereby achieving the purpose of draining the residual pickling liquid in the aquatic product; after the pressure in the tank returns to normal pressure, the tank cover 202 is opened to take out the frozen aquatic product.

[0051] In order to facilitate the loading and unloading of aquatic products, further, in a preferred embodiment, the pickling basket 5 can be placed in or taken out of the high-pressure pickling tank 2 through the tank opening 201.

[0052] In order to monitor the temperature of the pickling liquid inside and outside the barrier ring plate in real time, further, in a preferred embodiment, an inner-ring temperature sensor 203 is provided on the tank cover 202, and an outer-ring temperature sensor 204 is provided on the side wall of the high-pressure pickling tank 2 near the ice crystal formation positioning rod 4; specifically, the inner-ring temperature sensor 203 and the outer-ring temperature sensor 204 are both T-type temperature sensors with a minimum temperature sensor range of -50°C. They are connected to a thermometer to measure the temperature of the pickling liquid and aquatic products inside the barrier ring plate 1, and the temperature of the pickling liquid outside the barrier ring plate 1, respectively.

[0053] Furthermore, in a preferred embodiment, the ice crystal formation promoting component 4 is a metal rod in a dendritic shape. The metal rod in a dendritic shape can form more sites for ice crystal formation, and the metal rod can be used for heat transfer.

[0054] Furthermore, in a preferred embodiment, the pickling basket 5 includes a basket frame 501, a mesh surface 502 covering the sides and bottom of the basket frame 501, and a plurality of partitions 503 detachably arranged in the basket frame 501; based on this arrangement, the basket frame can be divided into multiple pickling areas by the partitions, thereby facilitating the separate pickling of different aquatic products and preventing the aquatic products from being stacked or squeezed from top to bottom.

[0055] In order to facilitate real-time observation of the pressure of the high-pressure pickling tank 2 and the safe operation of the high-pressure pickling tank 2, further, in a preferred embodiment, a safety valve 205 and a pressure gauge 206 for monitoring the internal pressure of the high-pressure pickling tank 2 are provided on the top wall of the high-pressure pickling tank 2; specifically, the range of the pressure gauge 206 is 0 to 100 MPa.

[0056] In order to facilitate the configuration of the pickling liquid, further, in a preferred embodiment, a stirring component 601 is provided in the pickling liquid storage tank 6 , and a breathing valve 602 is provided on the top of the pickling liquid storage tank 6 .

[0057] Furthermore, in a preferred embodiment, the lower end of the heating coil 11 is connected to the feed pipe 10 through a heating medium input pipe 1101 that passes through the bottom of the high-pressure pickling tank 2, and the upper end of the heating coil 11 is connected to the top of the pickling liquid storage tank 6 through a heating medium return pipe 1102, and a heating medium input valve 1103 is provided on the heating medium input pipe 1101; based on the above structure, the normal temperature pickling liquid stored in the pickling liquid storage tank 6 with a temperature of about 25°C can be transported to the heating coil 11 as a heating medium, so as to achieve the purpose of preventing the pickling liquid and aquatic products in the ring plate 1 from heating up, and at the same time, the purpose of pre-cooling the pickling liquid in the pickling liquid storage tank 6 can be achieved.

[0058] Furthermore, in a preferred embodiment, the tank wall of the high-pressure pickling tank 2 is made of alloy steel and the outer surface is wrapped with an insulation layer, and the high-pressure pickling tank 2 can withstand a high pressure higher than 100 MPa.

[0059] Example 2

[0060] A high-pressure pickling and energy-saving quick-freezing method at a temperature below the freezing point of aquatic products comprises the following steps:

[0061] S1. Prepare the pickling liquid: Prepare the pickling liquid in the pickling liquid storage tank 6. The pickling liquid is composed of sodium chloride, glycerol, trehalose, a flavor regulating component, and water. The freezing point of the pickling liquid at atmospheric pressure is controlled to be 2 to 3°C lower than the freezing point of aquatic products at atmospheric pressure. Generally, the freezing point of aquatic products is about -2 to -1°C. Preferably, the freezing point of the pickling liquid at atmospheric pressure is controlled to be -5 to -4°C.

[0062] S2. Filling: The aquatic product to be pickled is placed in the pickling basket 5 and transferred to the high-pressure pickling tank 2. Then, pickling liquid is added to the high-pressure pickling tank 2 until the pickling liquid fills the high-pressure pickling tank 2, so that the pickling liquid and the aquatic product are contained in the high-pressure pickling tank 2 in a sealed state with a constant volume.

[0063] S3. Low-temperature, high-pressure pickling: A low-temperature refrigerant 3-5°C below the freezing point of the pickling liquid at atmospheric pressure is continuously circulated into the refrigerant circulation and delivery chamber 3 to cool the material in the high-pressure pickling tank 2. Crystal nuclei are formed in the pickling liquid near the positioning rod 4 in the high-pressure pickling tank 2 and grow into ice crystals. The expansion of the ice crystals increases the pressure in the high-pressure pickling tank 2, thereby lowering the freezing point of the aquatic product and the pickling liquid. Eventually, the temperature of the pickling liquid reaches the same or close to that of the low-temperature refrigerant, and the pickling liquid in the high-pressure pickling tank 2 is in a state of equilibrium where solid and liquid coexist. At this time, the aquatic product will be pickled in a high-pressure environment with a temperature lower than its normal freezing point in an unfrozen state; in this step, the pickling pressure and pickling temperature can be adjusted by setting the temperature of the refrigerant, and the pickling time can be controlled by setting the continuous time of the refrigerant introduction. In fact, the pickling temperature is the temperature of the refrigerant introduced into the refrigerant circulation conveying chamber 3; preferably, the pickling time is controlled to be 3 to 4 hours to ensure that the salt diffusion and temperature in the aquatic product reach a balanced state; the pickling temperature is controlled to be -10 to -6°C, and the pickling pressure is controlled to be 20 to 60 MPa;

[0064] S4, pressure relief and quick freezing: The pickling liquid in the barrier ring plate 1 is continuously and rapidly heated. When the temperature of the pickling liquid in the barrier ring plate 1 reaches the freezing point of the pickling liquid at normal pressure, the heating of the pickling liquid in the barrier ring plate 1 is stopped, and the pressure relief valve 701 is immediately opened. The pressure in the high-pressure pickling tank 2 is instantly released. At this time, the temperature of the aquatic product is lower than its freezing point at normal pressure, and the aquatic product will freeze quickly. Then, the tank cover 202 is opened to take out the frozen aquatic product.

Claims

1. A high-pressure pickling and energy-saving quick-freezing device with a temperature below the freezing point of aquatic products, characterized in that include: A high-pressure pickling tank (2), wherein the peripheral tank wall of the high-pressure pickling tank (2) is provided with a refrigerant delivery cavity (3) for circulating refrigerant from bottom to top, a tank opening (201) is provided at the center of the top tank wall of the high-pressure pickling tank (2), and a detachable sealing cover on the tank opening (201) is closed with a tank cover (202); A pickling net basket (5), wherein the pickling net basket (5) is detachably arranged in the high-pressure pickling tank (2); A barrier ring plate (1), the barrier ring plate (1) being arranged around the periphery of the pickling net basket (5) in the high-pressure pickling tank (2), with the upper end of the barrier ring plate (1) being connected to the tank opening (201), and the lower end being sealedly connected to the bottom of the high-pressure pickling tank (2), and the upper end of the barrier ring plate (1) being provided with a plurality of flow holes (101) along the circumferential direction; A heating coil (11), the heating coil (11) being spirally arranged between the inner wall of the barrier ring plate (1) and the pickling basket (5), and being used to input a heating medium from bottom to top into the heating coil (11) to heat the pickling liquid in the barrier ring plate (1); An ice crystal formation positioning rod (4), the ice crystal formation positioning rod (4) being arranged between the outer wall of the barrier ring plate (1) and the inner wall of the high-pressure pickling tank (2) and located at the bottom of the high-pressure pickling tank (2), so as to enable the pickling liquid to first form crystal nuclei at positions near the ice crystal formation positioning rod (4) and grow into ice crystals when the pickling liquid drops below the freezing point; Pickling liquid storage tank (6); A feeding pipe (10), wherein the discharge port of the feeding pipe (10) is connected to the top of the high-pressure pickling tank (2), the feed port is connected to the bottom of the pickling liquid storage tank (6), and the feeding pipe (10) is provided with a feeding valve (1001) at one end close to the discharge port; A feeding pump (8), the feeding pump (8) being arranged on one end of the feeding pipe (10) close to the feeding port; a pickling liquid inspection pipe (9), the pickling liquid inspection pipe (9) being arranged on the top tank wall of the high-pressure pickling tank (2) and being in communication with the interior of the high-pressure pickling tank (2) for monitoring whether the high-pressure pickling tank (2) is full of pickling liquid, and a water stop valve (901) being arranged on the pickling liquid inspection pipe (9); and, A pressure relief pipe (7), one end of which is in communication with the bottom of the high-pressure pickling tank (2) within the barrier ring plate (1), and the other end of which is in communication with the top of the pickling liquid storage tank (6), and a pressure relief valve (701) is provided on the pressure relief pipe (7).

2. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: An inner ring temperature sensor (203) is provided on the tank cover (202), and an outer ring temperature sensor (204) is provided on the side wall of the high-pressure pickling tank (2) near the ice crystal generation positioning rod (4).

3. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: The ice crystal formation positioning rod (4) is a metal rod in the shape of a tree branch.

4. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: The pickling net basket (5) comprises a net basket frame (501), a mesh surface (502) covering the sides and bottom of the net basket frame (501), and a plurality of partition plates (503) detachably arranged in the net basket frame (501).

5. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: A safety valve (205) and a pressure gauge (206) for monitoring the internal pressure of the high-pressure pickling tank (2) are provided on the top wall of the high-pressure pickling tank (2).

6. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: A stirring assembly (601) is provided in the pickling liquid storage tank (6), and a breathing valve (602) is provided on the top of the pickling liquid storage tank (6).

7. The high-pressure pickling and energy-saving quick-freezing device below the freezing point of aquatic products according to claim 1, characterized in that: The lower end of the heating coil (11) is connected to the feed pipe (10) via a heating medium input pipe (1101) penetrating the bottom of the high-pressure pickling tank (2); the upper end of the heating coil (11) is connected to the top of the pickling liquid storage tank (6) via a heating medium return pipe (1102), and a heating medium input valve (1103) is provided on the heating medium input pipe (1101).

8. A high-pressure pickling and energy-saving quick-freezing method below the freezing point of aquatic products, characterized in that: The high-pressure pickling and energy-saving quick freezing process using the device described in claim 1 specifically comprises the following steps: S1. Prepare the pickling liquid: prepare the pickling liquid in the pickling liquid storage tank (6), wherein the pickling liquid is composed of sodium chloride, glycerol, trehalose, flavor regulating components and water, and the freezing point temperature of the pickling liquid at atmospheric pressure is controlled to be 2 to 3°C lower than the freezing point temperature of the aquatic product at atmospheric pressure; S2. Filling the material: The aquatic product to be pickled is placed in the pickling net basket (5) and transferred to the high-pressure pickling tank (2), and then the pickling liquid is added to the high-pressure pickling tank (2) until the pickling liquid fills the high-pressure pickling tank (2), so that the pickling liquid and the aquatic product are contained in the high-pressure pickling tank (2) in a sealed state with a constant volume; S3. Low-temperature and high-pressure pickling: A low-temperature refrigerant 3 to 5°C lower than the freezing point of the pickling liquid at atmospheric pressure is continuously circulated into the refrigerant circulation conveying chamber (3) to cool the material in the high-pressure pickling tank (2). The pickling liquid near the ice crystal generation positioning rod (4) in the high-pressure pickling tank (2) forms crystal nuclei and grows into ice crystals. The expansion of the ice crystals increases the pressure in the high-pressure pickling tank (2), thereby reducing the freezing point of the aquatic product and the pickling liquid. Finally, the temperature of the pickling liquid is the same as or close to that of the low-temperature refrigerant. The pickling liquid in the high-pressure pickling tank (2) is in an equilibrium state where solid and liquid coexist. At this time, the aquatic product is pickled in a high-pressure environment with a temperature lower than its freezing point at atmospheric pressure in an unfrozen state. S4, pressure relief and quick freezing: the pickling liquid in the barrier ring plate (1) is continuously and rapidly heated. When the temperature of the pickling liquid in the barrier ring plate (1) reaches the freezing point of the pickling liquid at normal pressure, the heating of the pickling liquid in the barrier ring plate (1) is stopped, and the pressure relief valve (701) is immediately opened. The pressure in the high-pressure pickling tank (2) is released instantly. At this time, the temperature of the aquatic product is lower than its freezing point at normal pressure, and the aquatic product will freeze quickly. After that, the tank cover (202) is opened to take out the frozen aquatic product.

9. The high-pressure pickling and energy-saving quick-freezing method below the freezing point of aquatic products according to claim 8, characterized in that: In step S3, the pickling pressure and the pickling temperature are adjusted by setting the temperature of the refrigerant, and the pickling time is controlled by setting the time for continuously introducing the refrigerant.

10. The high-pressure pickling and energy-saving quick-freezing method below the freezing point of aquatic products according to claim 9, characterized in that: The pickling time is controlled to be 3 to 4 hours, the pickling temperature is controlled to be -10 to -6°C, and the pickling pressure is controlled to be 20 to 60 MPa.

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