Vertical continuous cooling crystallizer and manufacturing method thereof

Abstract

The invention relates to a vertical continuous cooling crystallizer. The vertical continuous cooling crystallizer comprises a shell, a cooling coil and a fixing piece, wherein the cooling coil and the fixing piece are arranged in the shell; the fixed part is fixedly arranged in the shell; the cooling coil pipe comprises a steel pipe and a fixing plate, and the steel pipe is fixed on the fixing plate through a hoop; the steel pipe is arranged according to the shape of the mosquito coil and is formed by rolling from inside to outside at a time, and the whole coiled pipe formed by rolling is not provided with a secondary welding joint; and the fixed plate is fixedly connected with the fixed part in the vertical continuous cooling crystallizer through a bolt.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling crystallization, and in particular to a vertical continuous cooling crystallizer suitable for various materials in the biochemical industry and a manufacturing method thereof. Background Art

[0002] In the production of sugar alcohols (such as glucose, sorbitol, and mannitol) derived from corn, rice, or other raw materials, as well as in the amino acid industry (such as monosodium glutamate and citric acid), and the pharmaceutical industry, medium- and small-sized horizontal cooling crystallizers are currently the majority. Due to their technical structure, cooling and heat exchange are inadequate, materials are prone to leakage, and their intermittent operation makes continuous crystallization impossible. A vertical continuous cooling crystallizer is a vertical cylindrical container with multiple cooling plates arranged from bottom to top within the shell. These plates are connected to cooling medium pipelines outside the shell, enabling continuous crystallization, improving production efficiency, and maintaining stable product quality. Its rational cooling crystallization structure facilitates control and adjustment of crystallization process parameters, enabling multi-level temperature gradient control. The equipment can be equipped with a computer system for automatic control, saving energy. Existing cooling plates in vertical continuous cooling crystallizers are divided into tubular cooling plates and circular cooling plates. Existing tubular cooling plates come in two types: polygonal coils and annular rings. 1. Polygonal coil: This coil is formed into a polygonal shape by winding multiple straight coils or elbows in a certain order. The lower end of the coil is connected to the cooling medium inlet, and the upper end is connected to the cooling medium outlet. The cooling medium flows in a certain order in the tube, and the material flows from top to bottom outside the tube, and is stirred to form heat exchange.

[0003] 2. Annular cooling coils are composed of multiple layers and rings of steel pipes. Each layer of cooling coils is made up of multiple concentric rings. The diameter of each ring of cooling coils increases gradually from the center outward, and each ring of cooling coils is connected to form a passageway through elbows. The cooling module is divided into layers and blocks according to the needs of the cooling process. The layers are connected to form passageways with corresponding pipe fittings as needed. The lower end of the tube is connected to the cooling medium inlet, and the upper end is connected to the cooling medium outlet. The cooling medium flows in a certain order within the tube, and the material flows from top to bottom outside the tube, combined with stirring to form a heat exchange.

[0004] For polygonal cooling coils, since the coils are welded together into polygonal shapes by straight pipes or elbows, and the coils are grouped into four layers, with elbows welded between the layers, the coils have the following disadvantages: (1) There are many welded joints. The number of welded joints in each circle is equal to the number of sides of the polygon. The number of welded joints in each layer is the product of the number of circles of the coil and the number of sides of the polygon. Taking the hexagonal coil currently in service as an example, there are 5 circles per layer and each group of coils has 4 layers. Therefore, the number of welded joints (excluding the welded joints between elbows) is 6*5*4=120, which is labor-intensive and time-consuming.

[0005] (2) The joints between the coils are sharp-angle welded, which easily generates sharp-angle stress, unreliable welding quality, and a high risk of leakage.

[0006] (3) Difficulty in maintenance. Since the cooling coil is composed of four layers, each layer is connected by welding. After welding, if the middle two layers fail (leak), they cannot be repaired.

[0007] (4) The connection between each set of coils and the shell is welded, which is labor-intensive, inconvenient to operate, and time-consuming.

[0008] The annular cooling coil is composed of multiple layers of steel pipe. Each layer consists of multiple concentric rings, with the diameter of each ring increasing from the center and outward. Each ring of cooling coils is connected to form a passageway by elbows. The coil is grouped into four layers, and each layer is connected by welded elbows. This coil has the following disadvantages: (1) Compared with polygonal cooling coils, the number of welded joints in this cooling coil is relatively reduced, but a small number of welded joints still exist. Since these welded joints are welded manually, the quality of the welded joints varies.

[0009] (2) Difficulty in maintenance. Since the cooling coil is composed of four layers, each layer is connected by welding. After welding, if the middle two layers fail (leak), they cannot be repaired.

[0010] (3) The connection between each set of coils and the shell is welded, which is labor-intensive, inconvenient to operate, and time-consuming.

[0011] (4) The coil is spot-welded and fixed on the orifice plate. The orifice plate spacing is set according to the theoretical spacing. However, the actual coil has a certain error from the theoretical size during the bending process and cannot be accurately positioned. As a result, the vacancy needs to be modified during the manufacturing process, which causes a lot of modification work and generates some extra workload.

[0012] In addition, in the prior art, the fixing parts in the vertical continuous cooling crystallizer are fixed to the cooling coil by welding. This structure cannot be disassembled, and maintenance is inconvenient or even impossible. Summary of the Invention

[0013] The present invention aims to provide a vertical continuous cooling crystallizer, and the technical problem to be solved at least includes how to reduce a large amount of welding work and make the vertical continuous cooling crystallizer easy to maintain.

[0014] In order to achieve the above-mentioned object, the present invention provides a vertical continuous cooling crystallizer, comprising a shell and a cooling coil and a fixing member arranged inside the shell; the fixing member is fixedly installed inside the shell; the cooling coil comprises a steel pipe and a fixing plate, and the steel pipe is fixed to the fixing plate by a clamp; the steel pipe is arranged in the shape of a mosquito coil and is rolled from the inside out in one go, and the entire rolled coil has no secondary welding joints; the fixing plate and the fixing member in the vertical continuous cooling crystallizer are fixedly connected by bolts.

[0015] Preferably, the steel pipes are spliced ​​in advance using a steel pipe automatic laser welder to ensure the quality of the welded joints.

[0016] Preferably, after the steel pipes are spliced, they are rolled into shape in one go using a pipe bending mold.

[0017] Preferably, before splicing the steel pipes, the heat exchange area required for cooling crystallization is first calculated according to the process requirements, then converted into the total length of the coil according to the outer diameter specification of the coil, and then evenly divided into each layer of coils. After calculating the length of each layer of coils, the steel pipes are spliced ​​using an automatic laser welder.

[0018] Preferably, the steel pipe includes a first steel pipe and a second steel pipe, the first steel pipe is fixed on the upper surface of the fixing plate; the second steel pipe is fixed on the lower surface of the fixing plate.

[0019] Preferably, the first steel pipe and the second steel pipe are connected by a detachable movable connection structure.

[0020] Preferably, the detachable movable connection structure includes a connecting elbow and a quick connector.

[0021] Preferably, the quick connector includes a ferrule-type welding joint body, a connecting nut for a ferrule-type pipe joint and a cone-sealed welding pipe for a ferrule-type pipe joint. The ferrule-type welding joint body is used to be welded together with the first steel pipe or the second steel pipe; the cone-sealed welding pipe for a ferrule-type pipe joint is used to be welded together with the connecting elbow; the connecting nut for a ferrule-type pipe joint is used to connect the ferrule-type welding joint body and the cone-sealed welding pipe for a ferrule-type pipe joint together.

[0022] Preferably, the ferrule-type pipe joint is provided with an O-ring inside the cone-sealed welding pipe.

[0023] Preferably, the calculation formula for the heat exchange area required for the cooling crystallization is: A=Q / K*(t2-t1); Where: A is the heat exchange area required for cooling crystallization, and the calculation unit is: m2; Q is the heat transfer per unit time, calculated in W; K is the heat transfer coefficient, which indicates the amount of heat transferred per unit area per unit time when the temperature difference between the hot and cold fluids is 1°C. The calculation unit is: W / ㎡•℃; t2 is the average temperature of the material, calculated in ℃; t1 is the average temperature of the heat exchange medium, calculated in ℃.

[0024] Preferably, the total length of the coil is calculated as follows: L=A / π*d; Where: L is the total length of the coil, calculated in m; A is the heat exchange area required for cooling crystallization, and the calculation unit is: m2; d is the outer diameter of the coil, calculated in m.

[0025] Preferably, the steel pipe includes a cooling fluid inlet provided at the center of the mosquito coil and a cooling fluid outlet provided at the periphery of the mosquito coil, and the wall thickness of the steel pipe conforms to a heat transfer enhancement correction function, which is: Where: x is the distance along the central axis between any point on the central axis of the steel pipe and the cooling fluid inlet, calculated in meters; 0≤x≤L, where L is the total length of the coil; σ is the curvature of the steel pipe corresponding to the distance x along the central axis from the cooling fluid inlet; h0 is the wall thickness of the steel pipe at the inlet of the cooling fluid, calculated in m.

[0026] The present application also provides a method for manufacturing a vertical continuous cooling crystallizer, comprising the following steps: S1. Calculate the heat exchange area required for cooling crystallization according to the process requirements, then convert it into the total length of the coil according to the outer diameter of the coil, and then divide it evenly into each layer of coils, and calculate the length of each layer of coils; S2. After calculating the length of each layer of coiled pipe, the steel pipes are spliced ​​in advance using a dedicated steel pipe laser automatic welder to ensure the quality of the welded joints; S3. After the steel pipes are spliced, they are rolled into shape in one go using a pipe bending mold. The entire coiled pipe has no secondary welding joints. S4, fixing the rolled coil on the fixing plate through a clamp; S5. Fix the fixing plate to the fixing member in the vertical continuous cooling crystallizer by means of bolts.

[0027] Compared with the prior art, the present invention has the following beneficial effects: The vertical continuous cooling crystallizer described in the present invention is mainly used in the domestic production technology of sugar alcohols (such as glucose, sorbitol, mannitol, etc.) using corn, rice or other raw materials, amino acid industry (such as sodium glutamate, citric acid, etc.), pharmaceutical industry, etc., wherein the cooling plate and the fixing part are fixedly connected by bolts and are detachable for easy maintenance.

[0028] The cooling coil in this invention is a type of tubular cooling coil. It's structured like a mosquito coil. This coil is laid out in the shape of a mosquito coil, rolled from the inside out in a single process. The entire coil has no secondary welds, ensuring reliable quality and eliminating any risk of leakage.

[0029] The steel pipe and the fixing plate in the cooling coil of the present invention are fixed by a clamp type, which is not affected by the manufacturing error of the coil and can be fixed anywhere according to the actual position of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the specific embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0031] Figure 1 1 is a top view of the cooling coil according to the present invention.

[0032] Figure 2 It is a side view of the cooling coil described in the present invention.

[0033] Figure 3 It is a schematic diagram of the connection of cooling coils at different layers.

[0034] Figure 4 It is a schematic diagram of the connection between the fixing parts and the fixed plate in the vertical continuous cooling crystallizer.

[0035] Figure 5 It is a schematic diagram of the overall structure of the quick connector.

[0036] Figure 6 1 is an exploded schematic diagram of the quick connector. DETAILED DESCRIPTION

[0037] The present invention is described in more detail below to facilitate understanding of the present invention.

[0038] like Figures 1 to 6As shown, the vertical continuous cooling crystallizer described in the present invention includes a shell (not shown) and a cooling coil and a fixing member 15 arranged inside the shell; the fixing member is fixedly installed inside the shell; the cooling coil includes a steel pipe 1 and a fixing plate 4, and the steel pipe 1 is fixed to the fixing plate 4 by a clamp 5; the steel pipe 1 is arranged in the shape of a mosquito coil and is rolled from the inside out in one go, and the entire rolled coil has no secondary welding joints; the fixing plate 4 and the fixing member 15 in the vertical continuous cooling crystallizer are fixedly connected by bolts 16.

[0039] In the prior art, the steel pipe is fixed on the orifice plate by spot welding, which is inconvenient to adjust. The present application adopts a clamp-type fixation, which is not affected by the manufacturing error of the coil and can be fixed anywhere according to the actual position of the coil.

[0040] Preferably, the steel pipes are spliced ​​in advance using a steel pipe automatic laser welder to ensure the quality of the welded joints.

[0041] Preferably, after the steel pipes are spliced, they are rolled into shape in one go using a pipe bending mold.

[0042] Preferably, before splicing the steel pipes, the heat exchange area required for cooling crystallization is first calculated according to the process requirements, then converted into the total length of the coil according to the outer diameter specification of the coil, and then evenly divided into each layer of coils. After calculating the length of each layer of coils, the steel pipes are spliced ​​using an automatic laser welder.

[0043] The calculation formula for the heat exchange area required for cooling crystallization is: A=Q / K*(t2-t1); Where: A is the heat exchange area required for cooling crystallization, and the calculation unit is: m2; Q is the heat transfer per unit time, calculated in W; K is the heat transfer coefficient, which indicates the amount of heat transferred per unit area per unit time when the temperature difference between the hot and cold fluids is 1°C. The calculation unit is: W / ㎡•℃; t2 is the average temperature of the material, calculated in ℃; t1 is the average temperature of the heat exchange medium, calculated in ℃.

[0044] The total length of the coil is calculated as: L=A / π*d; Where: L is the total length of the coil, calculated in m; A is the heat exchange area required for cooling crystallization, and the calculation unit is: m2; d is the outer diameter of the coil, calculated in m.

[0045] In a preferred embodiment, the steel pipe 1 includes a cooling fluid inlet 2 provided at the center of the mosquito coil and a cooling fluid outlet 3 provided at the periphery of the mosquito coil. The wall thickness of the steel pipe 1 conforms to a heat transfer enhancement correction function, which is: Where: x is the distance along the central axis between any point on the central axis of the steel pipe 1 and the cooling fluid inlet 2, calculated in meters; 0≤x≤L, where L is the total length of the coil; σ is the curvature of the steel pipe corresponding to the distance x from the cooling fluid inlet 2 along the central axis; h0 is the wall thickness of the steel pipe 1 at the cooling fluid inlet 2, and the calculation unit is: m.

[0046] Because the heat exchange conditions of the cooling coils in a vertical continuous cooling crystallizer are relatively complex, and heat exchange efficiency is affected by multiple factors, including the temperature variation of the cooling fluid along the length of the coils, the wall thickness of the steel tube, and the crystallization state of the outer surface of the steel tube, to maximize the heat exchange efficiency of the cooling coils, the applicant fitted the above-mentioned heat exchange enhancement correction function based on a large amount of experimental data. Actual application results show that the heat exchange efficiency of cooling coils that conform to this heat exchange enhancement correction function is effectively improved. Compared with a control example in which the entire steel tube uses the same wall thickness, the heat exchange efficiency of cooling coils that conform to this heat exchange enhancement correction function is increased by at least 27.3%.

[0047] For the processing of steel pipes, by inputting the above-mentioned heat transfer enhancement correction function into the CNC machine tool, the required wall thickness can be obtained by grinding inside the steel pipe before splicing it using the steel pipe automatic laser welding machine.

[0048] It should be noted that the units (m, i.e., meters) of the physical quantities in the heat exchange enhancement correction function (such as the distance x along the central axis from the cooling fluid inlet 2 and the wall thickness h0 of the steel pipe 1 at the cooling fluid inlet 2) are used solely to indicate the magnitude of the values ​​and do not participate in the calculations within the formula. This is because the heat exchange enhancement correction function is a fitting function derived by fitting experimental data using SCILAB software, rather than a physical or mathematical formula derived through rigorous mathematical derivation. For example, assuming h0 is 10 meters, if the unit is changed to centimeters, h becomes 100 centimeters. The unit "meter" is simply used to indicate the magnitude of the value "10" and does not participate in the calculations within the function. If the unit "meter" is not limited to the formula, those skilled in the art may substitute the value "100 centimeters" into the formula, resulting in confusing calculation results.

[0049] Preferably, the steel pipe 1 includes a first steel pipe 11 and a second steel pipe 12 , the first steel pipe 11 is fixed on the upper surface of the fixing plate 4 ; the second steel pipe 12 is fixed on the lower surface of the fixing plate 4 .

[0050] Preferably, the first steel pipe 11 and the second steel pipe 12 are connected by a detachable movable connection structure.

[0051] Preferably, the detachable movable connection structure includes a connecting elbow 13 and a quick connector 14 .

[0052] Preferably, the fixing plate 4 is fixedly connected to the fixing member 15 in the vertical continuous cooling crystallizer by bolts 16 .

[0053] In the prior art, the cooling plate and the fixing member are fixed by welding, which is not detachable and inconvenient to repair or even impossible. The present invention adopts bolt fixing connection, which is detachable and convenient for repair.

[0054] like Figure 5 and Figure 6 As shown, in a preferred embodiment, the quick connector 14 includes a ferrule-type welding joint body 141, a connecting nut 142 for a ferrule-type pipe joint and a cone-sealed welding pipe 143 for a ferrule-type pipe joint. The ferrule-type welding joint body 141 is used to be welded together with the first steel pipe 11 or the second steel pipe 12; the cone-sealed welding pipe 143 for a ferrule-type pipe joint is used to be welded together with the connecting elbow 13; the connecting nut 142 for a ferrule-type pipe joint is used to connect the ferrule-type welding joint body 141 and the cone-sealed welding pipe 143 for a ferrule-type pipe joint together.

[0055] Preferably, an O-ring is provided inside the cone-sealed welding pipe 143 of the ferrule-type pipe joint.

[0056] The present application also provides a method for manufacturing a vertical continuous cooling crystallizer, comprising the following steps: S1. Calculate the heat exchange area required for cooling crystallization according to the process requirements, then convert it into the total length of the coil according to the outer diameter of the coil, and then divide it evenly into each layer of coils, and calculate the length of each layer of coils; S2. After calculating the length of each layer of coiled pipe, the steel pipes are spliced ​​in advance using a dedicated steel pipe laser automatic welder to ensure the quality of the welded joints; After the steel pipes are spliced, they are rolled into shape in one go using a pipe bending mold. The entire coiled pipe has no secondary welded joints. This ensures reliable coil quality and eliminates any risk of leakage.

[0057] S4, fixing the rolled coil on the fixing plate through a clamp; S5. Fix the fixing plate to the fixing member in the vertical continuous cooling crystallizer by means of bolts.

[0058] The coils in this application are secured with clamps, which are unaffected by coil manufacturing errors and can be fixed anywhere according to the actual coil location. If multiple layers of coils are required, removable flexible connections are used between each layer to ensure that each layer has no blind spots for maintenance. Furthermore, each set of coils is secured to the connecting components with a removable flexible connection, reducing welding work, eliminating welding deformation, and facilitating maintenance.

[0059] The preferred embodiments of the present invention are described above, but they are not intended to limit the present invention. Those skilled in the art may make improvements and changes to the embodiments disclosed herein without departing from the scope and spirit of the present invention.

Claims

1. A vertical continuous cooling crystallizer, characterized in that: The vertical continuous cooling crystallizer comprises a shell, a cooling coil and a fixing member arranged inside the shell; the fixing member is fixedly installed inside the shell; the cooling coil comprises a steel pipe and a fixing plate, and the steel pipe is fixed to the fixing plate by a clamp; the steel pipe is arranged in the shape of a mosquito coil and is rolled from the inside to the outside at one time, and the entire rolled coil has no secondary welding joints; the fixing plate and the fixing member in the vertical continuous cooling crystallizer are fixedly connected by bolts.

2. The vertical continuous cooling crystallizer according to claim 1, characterized in that: The steel pipes are spliced ​​in advance using a steel pipe laser automatic welding machine to ensure the quality of the welded joints.

3. The vertical continuous cooling crystallizer according to claim 2, characterized in that: After the steel pipes are spliced, they are rolled into shape in one go using a pipe bending mold.

4. The vertical continuous cooling crystallizer according to claim 2, characterized in that: Before splicing the steel pipes, the heat exchange area required for cooling and crystallization is first calculated according to the process requirements, then converted into the total length of the coil according to the outer diameter specification of the coil, and then evenly divided into each layer of coils. After calculating the length of each layer of coils, they are spliced ​​using a steel pipe automatic laser welding machine.

5. The vertical continuous cooling crystallizer according to claim 1, characterized in that: The steel pipe comprises a first steel pipe and a second steel pipe, wherein the first steel pipe is fixed on the upper surface of the fixing plate; and the second steel pipe is fixed on the lower surface of the fixing plate.

6. The vertical continuous cooling crystallizer according to claim 1, characterized in that: The first steel pipe and the second steel pipe are connected by a detachable movable connection structure.

7. The vertical continuous cooling crystallizer according to claim 6, characterized in that: The detachable live connection structure comprises a connecting elbow and a quick connector.

8. The vertical continuous cooling crystallizer according to claim 7, characterized in that: The quick connector includes a ferrule-type welding joint body, a connecting nut for a ferrule-type pipe joint and a cone-sealed welding pipe for a ferrule-type pipe joint. The ferrule-type welding joint body is used to be welded together with a first steel pipe or a second steel pipe; the cone-sealed welding pipe for a ferrule-type pipe joint is used to be welded together with a connecting elbow; the connecting nut for a ferrule-type pipe joint is used to connect the ferrule-type welding joint body and the cone-sealed welding pipe for a ferrule-type pipe joint together.

9. The vertical continuous cooling crystallizer according to claim 8, characterized in that: The cone sealing welding pipe of the ferrule type pipe joint is provided with an O-type sealing ring inside.

10. The vertical continuous cooling crystallizer according to claim 4, characterized in that: The calculation formula for the heat exchange area required for the cooling crystallization is: A=Q / K*(t2-t1); Where: A is the heat exchange area required for cooling crystallization, calculated in square meters; Q is the heat transfer per unit time, calculated in W; K is the heat transfer coefficient, which indicates the amount of heat transferred through a unit area in a unit time when the temperature difference between the cold and hot fluids is 1°C; the calculation unit is: W / ㎡•℃; t2 is the average temperature of the material, calculated in ℃; t1 is the average temperature of the heat exchange medium, calculated in units of ℃.

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