Horizontal sugar cooling crystallizer

Abstract

The utility model discloses a horizontal sugar cooling crystallizer which is characterized in that a front end cover and a rear end cover respectively cover a front port and a rear port of a horizontal cylinder, a feed port is arranged at the top of the front end of the cylinder, a discharge port is arranged at the lower part of the rear end cover, a central rotating cylinder is arranged along the axis of the cylinder, two ends of the central rotating cylinder are closed and are connected with rotating shafts, and the rotating shafts respectively extend out from the centers of the front end cover and the rear end cover; the shaft end of the front side rotating shaft is provided with a front rotating joint for leading in cooling water, and the shaft end of the rear side rotating shaft is provided with a rear rotating joint for leading out the cooling water; a plurality of groups of double-layer cooling coils are wound on the periphery of the central rotary drum, the double-layer cooling coils are alternately and continuously wound along the large-diameter circumference and the small-diameter circumference along the axial direction of the central rotary drum, inlets of the double-layer cooling coils are respectively connected with a water supply port on the central rotary drum, and outlets of the double-layer cooling coils are respectively connected with a water outlet on the central rotary drum. According to the horizontal sugar cooling crystallizer, the crystallization efficiency can be improved, the crystallization time can be shortened, the single productivity can be improved, meanwhile, the equipment structure is optimized, and the equipment operation failure rate is reduced.

Description

Technical Field

[0001] The utility model relates to a cooling crystallizer, in particular to a horizontal sugar cooling crystallizer, and belongs to the technical field of cooling equipment. Background Art

[0002] Currently, the domestic sugar crystallization industry is rapidly developing, and demand for large-scale vertical continuous cooling crystallizers is skyrocketing. While attention is focused on vertical continuous cooling crystallizers' space-saving and intelligent features, insufficient attention is paid to the quality stability and yield of the products produced by these machines. Similar products currently on the market commonly suffer from defects such as medium fluidity, heat balance, and unreasonable structural design.

[0003] The horizontal crystallizer is a long, horizontal cylinder structure primarily composed of a machine body, a machine jacket, heat exchange coils, a central shaft, a transmission mechanism, a bearing block, a saddle, and a scraper. The machine body, the main component of the crystallizer, serves as a trough for the liquid feed and forms the crystallizer's internal circulation system. Parts that come into contact with the material are constructed of stainless steel and polished after welding to achieve a high finish, ensuring product hygiene. The machine jacket serves as the crystallizer's external circulation system, circulating water through the jacket. Adjusting the amount of circulating water regulates the temperature of the liquid feed within the machine body to meet crystallization requirements.

[0004] The heat exchange coil, central shaft, and scraper plates are welded together to form an integrated unit, forming the crystallizer's internal cooling and stirring system. The heat exchange coil is directly immersed in the liquid feed. Circulating water flows through the heat exchange coil, regulating the liquid feed's temperature from within. As the central shaft rotates, the heat exchange coil and scraper plates rotate together, stirring the liquid feed, ensuring uniform mixing of all components. This effectively increases the crystallization rate and ensures uniform crystal size, significantly improving product quality. Furthermore, the minimal clearance between the scraper plates and the interior of the crystallizer allows them to scrape the crystals, preventing the liquid feed from crystallizing on the crystallizer due to low temperatures. This would hinder heat transfer between the circulating water and the liquid feed, reducing circulating water utilization. Under normal circumstances, both the central shaft and scraper plates are made of polished stainless steel, ensuring high heat transfer efficiency and high circulating water utilization. Adjusting the circulating water flow rate adjusts the cooling rate, ensuring a controlled crystallization process. Normally, the circulating water pressure in the central shaft and heat exchange coil does not exceed 0.2 MPa.

[0005] The saddle is the supporting structure of the entire equipment. The entire weight of the crystallizer and the liquid falls on the saddles distributed at both ends of the machine body. During installation, the saddle is connected to the foundation with anchor bolts or the saddle is directly welded to the embedded steel beam of the concrete foundation.

[0006] The existing horizontal crystallizer has a relatively simple structure. The cooling device mainly consists of an external jacket and an intermediate cooling coil. The intermediate coil is a single-layer structure and is located close to the outer wall. In actual use, due to the high viscosity and poor fluidity of the sugar solution, the external sugar solution temperature is prone to overcooling and the center temperature is undercooled, which affects the crystallization effect. The scraper is a continuous spiral structure, and the gap between it and the shell cannot be adjusted. Due to a certain degree of bending deflection caused by the deadweight of the shaft and the coil, the gap in some areas is too large, and the crystals adhere to the shell and cannot be removed. Due to the fluctuation of the cooling water pressure in the external jacket, the internal cylinder sinks inward, causing the equipment to fail to operate normally.

[0007] As a traditional and mature glucose cooling crystallization equipment, the horizontal crystallizer has a lot of public literature, papers, patents and other information in the industry. However, although there are some local improvements to the above pain points, there is no good overall system solution.

[0008] For example, Chinese utility model patent publication number CN 207024684U discloses a horizontal crystallizer. Its cooling structure, with the external jacket and cooling coils primarily located on the outside of the device, includes a stirring mechanism, but its low speed results in ineffective stirring. Consequently, the temperature of the sugar solution outside the device drops rapidly during operation, while the temperature of the sugar solution in the central rotating shaft drops more slowly. This results in uneven crystallization speed and compromises the overall crystallization efficiency. Furthermore, the external scraper, a continuous spiral ribbon structure, is welded to the cooling coils. Due to the deflection caused by the weight of the shaft and coils, the gap between the blades is excessive, allowing crystals to adhere to the housing and impairing the scraping efficiency. Fluctuations in cooling water pressure can cause the internal barrel of the external jacket to concave, disrupting normal operation. Due to the deflection caused by the weight of the shaft and cooling coils, as well as the impact of machining accuracy, the shaft seal of the horizontal crystallizer must be adaptable to shaft misalignment and deflection. However, this technical proposal does not describe the shaft seal design. Utility Model Content

[0009] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and utility model title of this application, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0010] In view of the above problems and / or the problems existing in the prior art, the present utility model is proposed.

[0011] The purpose of the utility model is to overcome the problems existing in the prior art and provide a horizontal sugar cooling crystallizer, which can improve crystallization efficiency, shorten crystallization time, increase single-unit production capacity, and optimize the equipment structure to reduce equipment operation failure rate.

[0012] In order to solve the above technical problems, the utility model provides a horizontal sugar cooling crystallizer, including a horizontal cylinder, the front end of the cylinder is covered with a front end cover, the rear end of the cylinder is covered with a rear end cover, the top of the front end of the cylinder is provided with a feed port, the lower part of the rear end cover is provided with a discharge port, and a central rotating cylinder is provided along the axis of the cylinder, the two ends of the central rotating cylinder are closed and are respectively connected to the rotating shaft, and the rotating shafts extend from the center of the front end cover and the rear end cover respectively, the shaft end of the front rotating shaft is provided with a front rotating joint for introducing cooling water, and the shaft end of the rear rotating shaft is provided with a rear rotating joint for draining cooling water; the outer side of the central rotating cylinder has multiple groups of double-layer cooling coils wrapped around, each double-layer cooling coil is continuously coiled along the large diameter circumference and the small diameter circumference alternately along the axial direction of the central rotating cylinder, the inlet of each double-layer cooling coil is respectively connected to the water supply port on the central rotating cylinder, and the outlet of each double-layer cooling coil is respectively connected to the water outlet on the central rotating cylinder.

[0013] As an improvement of the present invention, the inner cavity of the central rotating cylinder is provided with a cooling water inlet distribution pipe and a cooling water outlet distribution pipe. The inlet of the cooling water inlet distribution pipe is connected to the center hole outlet of the front rotating shaft, and the outlet of the cooling water inlet distribution pipe is respectively connected to the water supply ports on the central rotating cylinder; the inlet of the cooling water outlet distribution pipe is respectively connected to the water outlets on the central rotating cylinder, and the outlet of the cooling water outlet distribution pipe is connected to the center hole inlet of the rear rotating shaft.

[0014] As a further improvement of the present invention, a plurality of scraping plates for scraping the inner wall of the cylinder are provided along the axial direction of the cylinder, and the scraping plates are distributed along a spiral line. The middle of each scraping plate is fixed to one end of the support handle, and the other end of each support handle is fixed to the double-layer cooling coil.

[0015] As a further improvement of the present invention, the lifting direction of the spiral line is opposite to the lifting direction of the double-layer cooling coil.

[0016] As a further improvement of the present invention, the outer wall of the cylinder is provided with a honeycomb panel jacket, and a plurality of protrusions are evenly stamped on the honeycomb panel jacket, and each protrusion is close to the outer wall of the cylinder.

[0017] As a further improvement of the present invention, the honeycomb panel jacket is axially divided into multiple jacket cooling cavities, the bottom of each jacket cooling cavity is provided with a jacket cooling water inlet, and the top of each jacket cooling cavity is provided with a jacket cooling water outlet.

[0018] As a further improvement of the present invention, the centers of the front end cover and the rear end cover are sealed with the rotating shaft through flexible mechanical seals respectively.

[0019] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. The heat exchange area between the syrup and the cooling coil is larger, and the contact and heat exchange are more uniform and sufficient, so that the temperature difference of the syrup in the entire inner cavity of the cylinder is small, the heat exchange efficiency is high, and the sugar paste can be prevented from sticking to the outer wall of the cooling coil under the premise of rapid crystallization;

[0020] 2. To prevent the phenomenon of lumps on the inner wall of the cylinder due to the inability to renew the syrup, multiple scrapers are distributed along the spiral belt to replace the continuous spiral belt, avoiding scraping with the cylinder wall. This can keep a smaller gap with the cylinder wall, and is easy to replace and can more reliably scrape off the inner wall lumps.

[0021] 3. The convex points of the honeycomb panel jacket are fitted or connected to the outer wall of the cylinder. On the one hand, the strength of the cylinder is greatly improved. The cylinder can maintain high strength and rigidity with a thinner wall thickness, avoiding deformation during pressure fluctuations. On the other hand, the blocking effect of the convex points of the honeycomb panel jacket changes the cooling water from a laminar state to a turbulent state, greatly improving the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. The drawings are only provided for reference and explanation, and are not intended to limit the present invention. Among them:

[0023] Figure 1 This is a cross-sectional view of the horizontal sugar cooling crystallizer of the utility model;

[0024] Figure 2 It is a three-dimensional diagram of the double-layer cooling coil in the present utility model;

[0025] In the figure: 1. Cylinder; 1a. Feed inlet; 1b. Inspection hole;

[0026] 2. Front cover; 2a. Front shaft seal; 2b. Front bearing seat;

[0027] 3. Rear end cover; 3a. Rear end shaft seal; 3b. Rear end bearing seat; 3c. Discharge port;

[0028] 4. Central drum; 4a. Cooling water inlet distribution pipe; 4b. Cooling water outlet distribution pipe;

[0029] 5. Rotating shaft; 6. Front rotary joint; 6a. Rotating shaft cooling water inlet; 7. Rear rotary joint; 7a. Rotating shaft cooling water outlet;

[0030] 8. Double-layer cooling coil;

[0031] 9. Scraper; 9a. Handle;

[0032] 10. Honeycomb panel jacket; 10a. Jacket cooling water inlet; 10b. Jacket cooling water outlet. DETAILED DESCRIPTION

[0033] In the following description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific direction.

[0034] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific figures. Obviously, the embodiments described are only a part of the present invention, not all of the embodiments.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] like Figure 1 、 Figure 2 As shown, the horizontal sugar cooling crystallizer of the present invention comprises a horizontal cylinder 1, the front end of the cylinder being covered by a front cover 2, the rear end of the cylinder being covered by a rear cover, a feed port 1a being provided at the top of the front end of the cylinder 1, and an inspection hole 1b being provided at the top of the rear end of the cylinder 1. A discharge port 3c is provided at the lower portion of the rear cover, and a central rotating cylinder 4 is provided along the axis of the cylinder. Both ends of the central rotating cylinder 4 are closed and connected to a rotating shaft 5, which extends from the center of the front cover 2 and the rear cover, respectively.

[0037] The front end cover 2 is provided with a front shaft seal 2a in the center to seal with the rotating shaft 5, which is supported on the front bearing seat 2b. The rear end cover is provided with a rear shaft seal 3a in the center to seal with the rotating shaft 5, and the rear shaft is supported on the rear bearing seat 3b.

[0038] The shaft end of the front shaft is equipped with a front rotary joint 6 for introducing cooling water, and the front rotary joint 6 is provided with a shaft cooling water inlet 6a; the shaft end of the rear shaft is equipped with a rear rotary joint 7 for discharging cooling water, and the rear rotary joint 7 is provided with a shaft cooling water outlet 7a.

[0039] Multiple groups of double-layer cooling coils 8 are wound around the outside of the central rotating drum 4. Each double-layer cooling coil 8 is continuously coiled along the large diameter circumference and the small diameter circumference along the axial direction of the central rotating drum 4, and the inlet of each double-layer cooling coil 8 is respectively connected to the water supply port on the central rotating drum 4, and the outlet of each double-layer cooling coil 8 is respectively connected to the water outlet on the central rotating drum 4.

[0040] The inner cavity of the central rotating cylinder 4 is provided with a cooling water inlet distribution pipe 4a and a cooling water outlet distribution pipe 4b. The inlet of the cooling water inlet distribution pipe 4a is connected to the outlet of the center hole of the front rotating shaft, and the outlet of the cooling water inlet distribution pipe 4a is respectively connected to the water supply ports on the central rotating cylinder 4; the inlet of the cooling water outlet distribution pipe 4b is respectively connected to the outlets on the central rotating cylinder, and the outlet of the cooling water outlet distribution pipe 4b is connected to the inlet of the center hole of the rear rotating shaft.

[0041] A plurality of scrapers 9 are provided axially along the barrel 1 to scrape the inner wall of the barrel. Each scraper 9 is arranged along a spiral line, and the lifting direction of the spiral line is opposite to the lifting direction of the double-layer cooling coil 8. The middle of each scraper 9 is fixed to one end of a support handle 9a, and the other end of each support handle 9a is fixed to the double-layer cooling coil 8.

[0042] The cooling coil device, which rotates with the shaft, utilizes multiple groups of double-layer cooling coils. Cooling water enters the shaft cooling water inlet at one end of the shaft, passes through multiple groups of cooling coils, and then flows out of the shaft cooling water outlet at the other end of the shaft. The cooling water distribution between the multiple groups is in parallel, while the cooling water distribution for the inner and outer coils of each individual group is in series. The double-layer coils increase the heat exchange area per unit volume, improve crystallization efficiency, and provide a more uniform spatial distribution across the cylindrical cross-section. Due to the high viscosity and poor flow properties of the syrup during crystallization, the double-layer structure ensures more uniform and sufficient contact between the syrup and the cooling tubes, avoiding local overcooling and partial undercooling, and preventing uneven heat exchange from affecting the crystal formation rate. Compared to the parallel arrangement, the inner and outer coils in series do not cause differences in the cooling water flow path due to the different lengths of the inner and outer coils.

[0043] The temperature difference between the cooling water and the syrup is a crucial process parameter during the syrup crystallization process. Excessive temperature differences can cause the surface of the cooling coil to become firmly adhered to the massecuite and form agglomerates, hindering heat transfer and leading to large crystal size variations and subsequent separation difficulties. Too little temperature difference reduces heat transfer efficiency and slows the crystallization process. Therefore, the temperature difference between the cooling water and the syrup must be strictly controlled at around 3°C during production. The inner and outer coils are connected in series to avoid variations in cooling water flow distribution due to varying lengths. Furthermore, too many parallel branches, while maintaining a constant total cooling water flow, can result in insufficient flow within a single branch cooling tube, leading to low flow rates and impacting the convective heat transfer coefficient.

[0044] Arranging multiple groups of cooling coils in parallel along the axial direction of the rotating shaft can ensure that the temperature of the cooling coils of the entire tank body does not change much, there is no large temperature gradient from the front end to the rear end, and the overall temperature difference between the cooling water and the syrup in the tank is not much, the crystallization conditions are basically the same, the crystal formation, growth, and final forming size are relatively more stable, thereby improving production efficiency.

[0045] The outer cooling jacket of the tank body adopts a honeycomb panel jacket 10, on which a plurality of protrusions are evenly stamped, and each protrusion is close to the outer wall of the cylinder; the cooling water flows along the flow channel between the protrusions. Due to the blocking effect of each protrusion, the flow state of the cooling water is improved, the boundary stagnation layer is broken, the thermal resistance is reduced, turbulence can be generated even at a low cooling water flow rate, the convective heat transfer coefficient is improved, and the crystallization process is strengthened.

[0046] Similarly, the outer cooling jacket is also divided axially into multiple independent jacket cooling chambers. Each jacket cooling chamber has a jacket cooling water inlet 10a at its bottom and a jacket cooling water outlet 10b at its top. Cooling water distribution within each independent jacket is also parallel. Furthermore, the honeycomb panel jacket 10 structure improves the stress distribution of the inner cylinder. Through the connection point between the inner and outer cylinders, the inner and outer cylinders form a rigid whole, greatly enhancing their ability to withstand static pressure. This avoids the current industry-wide issues of inner cylinder concavity and equipment malfunction caused by cooling water pressure fluctuations. This structure also reduces material usage in manufacturing equipment, resulting in better economic benefits.

[0047] To address the problem of syrup sticking and agglomerating on the inner wall of the shell cylinder during crystallization, which results in reduced heat transfer performance and scraping and jamming of the rotating shaft, a scraper plate 9 is arranged spirally on the outside of the double-layer cooling coil 8, with an adjustable gap between the scraper plate and the cylinder wall. The scraper plate 9 is made of a wear-resistant plastic plate at the end to protect the inner cylinder wall from scraping. It is also easy to replace and can achieve a smaller gap, better scraping away the inner wall agglomerates. Currently, the industry generally uses rigid, integral spiral scrapers. Due to the certain bending deflection caused by the weight of the shaft and coil, the gap between the most deformed part and the cylinder wall is large, resulting in poor scraping effect. A small gap between the scraper plate and the cylinder wall can easily cause the scraper plate to scrape against the inner wall, resulting in mechanical jamming and wear of the cylinder wall or the scraper plate. Wear makes it difficult to replace the scraper plate, reducing the service life of the equipment.

[0048] This horizontal sugar crystallizer utilizes flexible mechanical seals at both ends of the shaft seal, capable of compensating for minor misalignment of the shaft ends. This provides a superior solution for the large-diameter, heavy, and long coil shafts. This effectively avoids material leakage, poor hygiene, and air leakage into the material, which can affect quality and can be a problem in existing industry-standard structures.

[0049] The above description is only a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may have other implementation methods without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. Technical features not described in the present invention can be achieved by or using existing technologies, and will not be described here.

Claims

1. A horizontal sugar cooling crystallizer, comprising a horizontal cylinder, a front end of the cylinder covered with a front cover, a rear end of the cylinder covered with a rear cover, a feed port provided at the top of the front end of the cylinder, and a discharge port provided at the bottom of the rear cover, characterized in that: A central rotating drum is provided along the axis of the cylinder, and both ends of the central rotating drum are closed and respectively connected to a rotating shaft, and the rotating shafts extend from the center of the front end cover and the rear end cover respectively. The shaft end of the front rotating shaft is equipped with a front rotating joint for introducing cooling water, and the shaft end of the rear rotating shaft is equipped with a rear rotating joint for draining cooling water; multiple groups of double-layer cooling coils are wrapped around the outside of the central rotating drum, and each double-layer cooling coil is continuously coiled along the large diameter circumference and the small diameter circumference alternately along the axial direction of the central rotating drum, the inlet of each double-layer cooling coil is respectively connected to the water supply port on the central rotating drum, and the outlet of each double-layer cooling coil is respectively connected to the water outlet on the central rotating drum.

2. The horizontal sugar cooling crystallizer according to claim 1, characterized in that: The inner cavity of the central rotating cylinder is provided with a cooling water inlet distribution pipe and a cooling water outlet distribution pipe. The inlet of the cooling water inlet distribution pipe is connected to the center hole outlet of the front rotating shaft, and the outlet of the cooling water inlet distribution pipe is respectively connected to the water supply ports on the central rotating cylinder; the inlet of the cooling water outlet distribution pipe is respectively connected to the water outlets on the central rotating cylinder, and the outlet of the cooling water outlet distribution pipe is connected to the center hole inlet of the rear rotating shaft.

3. The horizontal sugar cooling crystallizer according to claim 1, characterized in that: A plurality of scraping plates for scraping the inner wall of the cylinder are arranged along the axial direction of the cylinder. The scraping plates are distributed along a spiral line. The middle of each scraping plate is fixed to one end of a support handle, and the other end of each support handle is fixed to a double-layer cooling coil.

4. The horizontal sugar cooling crystallizer according to claim 3, characterized in that: The lifting direction of the spiral line is opposite to the lifting direction of the double-layer cooling coil.

5. The horizontal sugar cooling crystallizer according to any one of claims 1 to 4, characterized in that: The outer wall of the cylinder is provided with a honeycomb panel jacket, and a plurality of protrusions are evenly punched on the honeycomb panel jacket, and each protrusion is close to the outer wall of the cylinder.

6. The horizontal sugar cooling crystallizer according to claim 5, characterized in that: The honeycomb panel jacket is divided into a plurality of jacket cooling cavities along the axial direction. The bottom of each jacket cooling cavity is provided with a jacket cooling water inlet, and the top of each jacket cooling cavity is provided with a jacket cooling water outlet.

7. The horizontal sugar cooling crystallizer according to any one of claims 1 to 4, characterized in that: The centers of the front end cover and the rear end cover are sealed with the rotating shaft through flexible mechanical seals respectively.

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