Rotary evaporation system with improved circulating water type vacuum pump

Abstract

The utility model relates to a rotary evaporation system with an improved circulating water type vacuum pump, belongs to the field of distillation equipment, and solves the problem that when the temperature of a water ring pump is controlled by the existing rotary evaporation equipment, the comprehensive performance optimization of economy, practicability, environmental protection and resource conservation is difficult to realize at the same time. The utility model discloses a rotary evaporation system with an improved circulating water type vacuum pump. The rotary evaporation system comprises the circulating water type vacuum pump, low-temperature circulating equipment and a rotary evaporator, according to the rotary evaporation system provided by the utility model, the temperature of the water ring pump is effectively controlled so as to ensure the rotary evaporation efficiency, and the optimization of the comprehensive performance of economy, practicability, environmental protection and resource conservation is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to distillation equipment technical field especially relates to a kind of rotary evaporation system with improved circulating water type vacuum pump. BACKGROUND

[0002] The working principle of rotary evaporator is based on reduced pressure distillation and rotary thin film evaporation. Rotary evaporator is usually used with water circulating type vacuum pump (referred to as water ring pump) to maintain the vacuum degree inside rotary evaporator, and refrigeration equipment is used to provide cooling medium for the condenser of rotary evaporator. However, as the water ring pump operates, the temperature of working water in the water ring pump gradually rises, and the vacuum degree decreases, affecting the efficiency of rotary evaporation. The current practice is to continuously supplement circulating water to the water ring pump, which not only causes great waste of water, but also makes it difficult to reduce the water temperature during long-term use, affecting the efficiency of rotary evaporation, and when some low-boiling-point solvents are evaporated, gas is easily volatilized, and part of the solvent is drawn into the water tank of the water ring pump, causing air pollution due to the high temperature of the water tank.

[0003] To solve the above problems, although some improvements and researches have been made on rotary evaporation system, these improved rotary evaporation systems are often complex in structure or require a lot of structural improvements to existing devices, which is not cost-effective and has poor practicality, hindering its practical industrial application. INVENTION CONTENTS

[0004] In view of the above analysis, the utility model aims to provide a rotary evaporation system with improved circulating water type vacuum pump to solve the problem that the existing rotary evaporation equipment is difficult to achieve economic, practical, environmental and resource-saving comprehensive performance optimization when controlling the temperature of water ring pump.

[0005] The purpose of the utility model is achieved by the following technical solutions:

[0006] The utility model provides a rotary evaporation system with improved circulating water type vacuum pump, which comprises a circulating water type vacuum pump, a low-temperature circulating device and a rotary evaporator.

[0007] The circulating water type vacuum pump comprises a water tank, a cooling device is arranged in the water tank, the main body of the cooling device is fixed and installed in the water tank by a support, the main body of the cooling device extends out a liquid inlet end part comprising a first liquid inlet and a liquid outlet end part comprising a first liquid outlet, and the liquid inlet end part and the liquid outlet end part are sealingly installed on the tank wall of the water tank by a connecting piece.

[0008] The low-temperature circulating device comprises a second liquid inlet and a second liquid outlet.

[0009] The rotary evaporator comprises a condenser, and the condenser is provided with a third liquid inlet and a third liquid outlet at both ends.

[0010] The second liquid outlet of the low-temperature circulating device is connected with the third liquid inlet of the rotary evaporator, the third liquid outlet of the rotary evaporator is connected with the first liquid inlet of the circulating water vacuum pump, and the first liquid outlet of the circulating water vacuum pump is connected with the second liquid inlet of the low-temperature circulating device.

[0011] Further, the main body of the cooling device comprises at least one of a cooling coil or a cooling disc, the cooling disc having an internal flow channel; the number of the cooling coil or the cooling disc is one or more.

[0012] Further, the support comprises a fixed column, one end of the fixed column being connected to a fixed base mounted on the inner surface of the bottom of the water tank, the other end extending upward away from the bottom of the water tank, the top and / or the peripheral side of the fixed column being fixedly connected with the cooling device; the fixed column is one or more.

[0013] Further, the connecting piece comprises two flanges, which are respectively sealingly mounted at different positions of the wall of the water tank; the inner hole of each flange is sealingly connected with the outer wall of the liquid inlet end or the liquid outlet end of the cooling device through a sealing piece or a thread.

[0014] Further, the circulating water vacuum pump further comprises a pump body, the part of the pump body immersed in the water tank being referred to as an immersion assembly; the cooling device is mounted in the accommodation space formed between the water tank and the immersion assembly.

[0015] Further, the cooling coil is a spiral coil or a serpentine coil, the spiral coil or the serpentine coil being arranged below and / or on one side of and / or around the immersion assembly; and / or,

[0016] The cooling disc is a disc-shaped plate, which is a disc-shaped plate with or without a through hole; wherein the through hole is used to accommodate the immersion assembly so that the disc-shaped plate with a through hole is arranged around the immersion assembly; the disc-shaped plate without a through hole is arranged below or on one side of the immersion assembly.

[0017] Further, the serpentine coil or the disc-shaped plate is arranged horizontally parallel to the bottom of the water tank; and / or,

[0018] The cooling coil is a finned tube.

[0019] Further, the main body of the cooling device is formed by the parallel connection of a main cooler and an auxiliary cooler, the main cooler and the auxiliary cooler sharing one liquid inlet end and one liquid outlet end, one three-way valve being arranged at the branch of the main cooler and the auxiliary cooler respectively, and one flow control valve being arranged at the water inlet end.

[0020] Further, when the cooling coil is a spiral coil, the pitch p of the spiral coil is (1 / 45-1 / 35)H, and the coiled diameter D is (3 / 5-4 / 5)×W; wherein H is the height of the water tank, and W is the minimum lateral dimension of the water tank in the plane perpendicular to the height of the water tank; and / or,

[0021] When the cooling coil is a serpentine coil, or when the cooling coil has an internal flow channel that is a serpentine flow channel, the bending radius R of the serpentine coil or the serpentine flow channel is greater than or equal to 1.5d eq , and the maximum pitch S max =(1 / 2-3 / 4)W.

[0022] where d eq is the equivalent inner diameter of the coil or flow channel, which is defined as the inner diameter of a circular pipe or flow channel having the same cross-sectional area, S max is the distance between the farthest two flow channel center lines in the serpentine coil or serpentine flow channel, and W is the minimum lateral dimension of the water tank in a plane perpendicular to its height.

[0023] Further, when the main body of the cooling device is an equal-diameter cooling coil, the internal volume V2 of the cooling coil satisfies V2=(1 / 55-1 / 45)V1, V2=S2*L2, where S2 is the cross-sectional area of the cooling coil, L2 is the total length of the cooling coil, and V1 is the volume of the accommodation space formed between the water tank and the immersion assembly; or,

[0024] When the main body of the cooling device is a cooling disc, the cooling disc has an internal flow channel and the internal flow channel is equal-diameter, the total volume V3 of the internal flow channel satisfies V3=(1 / 150-1 / 200)V1, V3=S3*L3, where S3 is the cross-sectional area of the internal flow channel, L3 is the total length of the internal flow channel, and V1 is the volume of the accommodation space formed between the water tank and the immersion assembly.

[0025] Compared with the prior art, the utility model can realize at least one of the following beneficial effects:

[0026] The rotary evaporation system can effectively control the temperature of the water ring pump to ensure the rotary evaporation efficiency with less structural improvement, and realizes the optimization of the comprehensive performance of economy, practicality, environmental protection and resource saving.

[0027] (a) By embedding a cooling device in the water tank of the circulating water type vacuum pump, and by improving the connection mode of the main components in the system, the secondary use of the low-temperature cooling liquid provided by the low-temperature circulating equipment is realized, that is, the low-temperature cooling liquid flows in the cooling device embedded in the water tank, avoiding the temperature of the working water in the water tank being too high and causing the vacuum degree to drop. The rotary evaporation system can effectively ensure the efficiency of rotary evaporation during long-term use.

[0028] (b) Since the cooling device is embedded in the water tank of the circulating water type vacuum pump, the temperature control of the water tank no longer relies on the continuous supply of cooling water, thereby saving a large amount of water resources. The rotary evaporation system has the advantage of resource saving.

[0029] (c) In the evaporation of some low boiling point harmful solvents, due to the built-in cooling device in the water tank, even if some harmful solvents enter the water tank, the water tank will not be volatilized into the air due to the high temperature of the water tank, the rotary evaporation system has more environmentally friendly advantages.

[0030] (d) Compared with some existing rotary evaporation systems, the utility model has the ingenuity of not needing to make too many and / or complex structural modifications to the existing device, and by improving the connection relationship in the water tank of the water ring pump to realize the secondary utilization of the low-temperature cooling liquid, the above-mentioned beneficial effects of ensuring rotary evaporation, resource conservation and environmental protection can be achieved with such a small structural improvement, and the advantages of better economy and practicality are obtained.

[0031] In the utility model, the above-mentioned technical solutions can also be combined with each other to realize more preferred combination schemes. Other features and advantages of the utility model will be described in the subsequent specification, and some advantages can become apparent from the specification, or can be understood by implementing the utility model. The purpose and other advantages of the utility model can be realized and obtained from the contents specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0032] The drawings are only for the purpose of illustrating specific embodiments and are not considered to be a limitation of the utility model, and in the entire drawings, the same reference signs represent the same parts.

[0033] Figure 1 The structure schematic view of the rotary evaporation system with the improved circulating water type vacuum pump provided by the embodiment of the utility model is shown in the figure.

[0034] Figure 2 The structure schematic view of the water tank in the improved circulating water type vacuum pump provided by the embodiment of the utility model is shown in the figure. Figure 1 The structure schematic view of the water tank in the improved circulating water type vacuum pump provided by the embodiment of the utility model is shown in the figure.

[0035] Figure 3 The structure schematic view of the cooling disc provided by the embodiment of the utility model is shown in the figure (top view direction); wherein (a) and (b) are two layout modes of the internal flow channel.

[0036] Figure 4 The structure schematic view of the cooling disc provided by the embodiment of the utility model is shown in the figure (top view direction); wherein (a) and (b) are two layout modes of the internal flow channel. Figure 1 The structure schematic view of the cooling disc provided by the embodiment of the utility model is shown in the figure (top view direction); wherein (a) and (b) are two layout modes of the internal flow channel.

[0037] Figure 5 The structure schematic view of the cooling disc provided by the embodiment of the utility model is shown in the figure (top view direction); wherein (a) and (b) are two layout modes of the internal flow channel.

[0038] Figure 6 The structure schematic view of the cooling disc provided by the embodiment of the utility model is shown in the figure (top view direction); wherein (a) and (b) are two layout modes of the internal flow channel.

[0039] Reference signs:

[0040] 1 - circulating water vacuum pump; 11 - water tank; 12 - cooling device; 12A - main cooler; 12B - auxiliary cooler; 121 - liquid inlet end; 121a - first liquid inlet; 122 - liquid outlet end; 122b - first liquid outlet; 123 - internal flow channel; 13 - fixed column; 13a - first fixed column; 13b - second fixed column; 13c - third fixed column; 13d - fourth fixed column; 14 - fixed base; 15 - flange; 16 - immersion assembly; 17 - three-way valve; 18 - flow control valve; 19 - vacuum gauge; 2 - low-temperature circulating device; 2a - second liquid inlet; 2b - second liquid outlet; 3 - rotary evaporator; 31 - condenser; 31a - third liquid inlet; 31b - third liquid outlet. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present application will be described in detail below with reference to the drawings, wherein the drawings constitute a part of the present application and serve to explain the principles of the present application together with the embodiments of the present application, but are not intended to limit the scope of the present application.

[0042] When the rotary evaporator is working, the low-temperature circulating device provides low-temperature coolant to cool the evaporated gas. After the task of cooling the evaporated gas is completed, the coolant still has a certain amount of refrigeration surplus. The inventor considers using this part of the refrigeration surplus to control the temperature of the working water in the water ring pump to avoid the temperature of the water from rising too high to affect the vacuum degree or the low-boiling-point solvent from evaporating into the air and polluting the environment after entering the water tank due to the excessively high temperature of the water. However, how to still achieve temperature control of the water ring pump with relatively small structural improvements to the rotary evaporation system while taking into account the comprehensive performance optimization of economy, practicality, environmental protection, and resource conservation is a challenge. After research, the inventor proposes a rotary evaporation system with an improved circulating water vacuum pump, and the specific embodiments and some possible embodiments are as follows, see Figures 1-6 .

[0043] The embodiment of the present application provides a rotary evaporation system with an improved circulating water vacuum pump, which comprises a circulating water vacuum pump 1, a low-temperature circulating device 2 and a rotary evaporator 3.

[0044] The circulating water vacuum pump 1 comprises a water tank 11, and a cooling device 12 is arranged in the water tank 11. The main body of the cooling device 12 is fixed and installed in the water tank through a support. The main body of the cooling device 12 extends out of a liquid inlet end 121 comprising a first liquid inlet 121a and a liquid outlet end 122 comprising a first liquid outlet 122b. The liquid inlet end 121 and the liquid outlet end 122 are sealingly installed on the tank wall of the water tank through a connecting piece.

[0045] The low-temperature circulating device 2 comprises a second liquid inlet 2a and a second liquid outlet 2b;

[0046] The rotary evaporator 3 comprises a condenser 31, and the condenser 31 is respectively provided with a third liquid inlet 31a and a third liquid outlet 31b at two ends;

[0047] The second liquid outlet 2b of the low-temperature circulating device 2 is connected with the third liquid inlet 31a of the rotary evaporator 3, the third liquid outlet 31b of the rotary evaporator is connected with the first liquid inlet 121a of the circulating water vacuum pump 1, and the first liquid outlet 122b of the circulating water vacuum pump 1 is connected with the second liquid inlet 2a of the low-temperature circulating device 2.

[0048] Compared with the prior art, the rotary evaporation system can effectively control the temperature of the water ring pump to ensure the rotary evaporation efficiency with less structural improvement, and realizes the optimization of the comprehensive performance of economy, practicality, environmental protection and resource saving.

[0049] (a) By embedding the cooling device in the water tank of the circulating water vacuum pump, and by improving the connection mode of the main components in the system, the secondary utilization of the low-temperature cooling liquid provided by the low-temperature circulating device is realized, that is, the low-temperature cooling liquid flows in the cooling device embedded in the water tank, so as to avoid the temperature of the working water in the water tank being too high and causing the vacuum degree to decrease.

[0050] (b) Since the cooling device is embedded in the water tank of the circulating water vacuum pump, the water tank temperature control no longer relies on continuous cooling water supply, thereby saving a large amount of water resources, and the rotary evaporation system has the advantage of resource saving.

[0051] (c) When some low-boiling-point harmful solvents are evaporated, since the cooling device is embedded in the water tank, even if some harmful solvents enter the water tank, they will not be volatilized into the air due to the high temperature of the water tank.

[0052] (d) Compared with some existing rotary evaporation systems, the rotary evaporation system has the advantages of better economy and practicality.

[0053] It can be understood that the circulating water vacuum pump for the rotary evaporation system comprises other necessary components in addition to the water tank 11 to provide negative pressure, for example, the circulating water vacuum pump 1 further comprises a pump body, the part of the pump body that extends into the water tank 11 is referred to as an immersion assembly 16; and the cooling device 12 is installed in the accommodation space formed between the water tank 11 and the immersion assembly 16.

[0054] In most cases, due to the need to accommodate the immersion assembly 16 inside the water tank 11, the space remaining for placing the cooling device is relatively limited. In order to enable the cooling device to provide better cooling effect in the limited space of the water tank, the main body of the cooling device 12 is composed of one or more coolers.

[0055] In some preferred embodiments, the main body of the cooling device 12 comprises at least one of a cooling coil or a cooling disc with an internal flow channel. The number of cooling coils or cooling discs is one or more.

[0056] In some embodiments, the support comprises a fixed column 13, one end of which is connected to a fixed base 14 installed on the inner surface of the bottom of the water tank 11, and the other end extends upward away from the bottom of the water tank 11, and the top and / or the peripheral side of the fixed column 13 is fixedly connected to the cooling device 12; the number of fixed columns 13 is one or more.

[0057] In order to achieve more stable support effect, the number and position relationship of the fixed columns satisfy at least one of the following characteristics:

[0058] (1) The fixed columns 13 are evenly distributed around the cooling device 12;

[0059] (2) The number of fixed columns is at least 3;

[0060] (3) The plurality of fixed columns are centrally symmetrically distributed about the center of gravity of the cooling device 12.

[0061] Exemplarily, when the main body of the cooling device 12 is a cooling coil, the peripheral side of the fixed column 13 is fixedly connected to the outer pipe wall of the cooling coil.

[0062] Exemplarily, when the main body of the cooling device 12 is a cooling disc, the top of the fixed column 13 is fixedly connected to the lower surface of the cooling disc; and / or, the peripheral side of the fixed column 13 is fixedly connected to the outer side wall or the inner side wall of the cooling disc.

[0063] The "outer side wall" refers to the outer peripheral side surface of the disc, which is the curved or planar part extending vertically downward from the outer edge of the upper surface to the outer edge of the lower surface. The "inner side wall" refers to the inner peripheral side surface of the hole in the middle of the disc, which is the curved or planar part extending vertically downward from the inner edge of the upper surface to the inner edge of the lower surface.

[0064] In view of the limited accommodation space inside the water tank 11, in order to minimize the influence of the cooling device on the flow of working water in the water tank while ensuring stable support, preferably, the number of fixed columns 13 is four, i.e., the first fixed column 13a, the second fixed column 13b, the third fixed column 13c, and the fourth fixed column 13d, which are arranged in a four-symmetrical manner around the cooling device 12, meaning that the four fixed columns are respectively located on the four corners of a rectangle, square or rhombus, such a layout can provide stable support and ensure balanced distribution of the weight of the cooling device 12.

[0065] Exemplarily, the stable combination between the fixed column 13 and the cooling device 12, between the fixed column 13 and the fixed base 14, and between the fixed base 14 and the inner surface of the bottom of the water tank 11 is achieved by fixed connection, which includes but is not limited to welding, gluing, and mechanical fastening.

[0066] In view of the fact that the working water is stored in the water tank 11, it is crucial to ensure the sealing performance when the water inlet end and the water outlet end of the cooling device are connected to the tank wall of the water tank 11. Specifically, the sealing connection between the water inlet end 121 and the water outlet end 122 of the cooling device and the tank wall of the water tank is achieved by a connecting piece.

[0067] Exemplarily, the connecting piece includes two flanges 15, which are respectively sealingly installed on different positions of the tank wall of the water tank 11; the inner hole of each flange 15 is sealingly connected to the outer wall of the liquid inlet end 121 or the liquid outlet end 122 of the cooling device by a sealing piece or a thread, see Figure 4 For example, the flange 15 is sealingly installed on the tank wall of the water tank 11 by a hot melting method.

[0068] In order to achieve better cooling effect in the limited accommodation space of the water tank, the layout of the cooling coil and the cooling disc in the water tank can be optimized in combination with different structural forms of the cooling coil and the cooling disc, for example, at least one of the following characteristics is met:

[0069] (a) The cooling coil is a spiral coil or a serpentine coil, which is located below and / or on one side of and / or around the immersion assembly 16; the cooling coil is one or more;

[0070] (b) The cooling disc is a disc-shaped plate, which is a disc-shaped plate without through holes or a disc-shaped plate with through holes; wherein the through holes are used to accommodate the immersion assembly 16 so that the disc-shaped plate with through holes is arranged around the immersion assembly 16; the disc-shaped plate without through holes is located below or on one side of the immersion assembly 16.

[0071] It can be understood that the placement of the serpentine coil or the disc-shaped plate relative to the bottom of the water tank 11 includes but is not limited to horizontal placement and vertical placement. Considering the flow direction of the working water in the water tank, in order to make the cooling device have higher heat exchange efficiency, better stability and smaller resistance to the working water, preferably, the serpentine coil or the disc-shaped plate is arranged horizontally along the bottom of the water tank.

[0072] In an embodiment, the cooling coil is a finned tube. The finned tube effectively improves the heat transfer efficiency by increasing the surface area, so that it has a smaller overall volume under the same cooling demand, and is particularly suitable for the case where the installation space in the water tank is limited. In addition, the smaller overall volume of the finned tube can reduce the flow resistance to the working water while the working water is in the cooling water tank.

[0073] Considering that the rotary evaporator has higher requirements for the control of the water temperature in the water tank under the working condition of long-time operation, therefore, it is an effective solution to arrange the cooling device as a main and auxiliary cooler with a parallel structure. Under normal working conditions, the main cooler is sufficient to meet the cooling demand and keep the water temperature in the water tank stable. When the main cooler is insufficient in cooling capacity to maintain the water temperature in the ideal range under special long-time working conditions, the auxiliary cooler can be enabled. The addition of the auxiliary cooler can provide additional cooling capacity to ensure that the temperature in the water tank does not rise excessively, thereby ensuring the long-time efficient operation of the rotary evaporator.

[0074] In an embodiment, the main body of the cooling device 12 is formed by the main cooler 12A and the auxiliary cooler 12B in parallel, the main cooler and the auxiliary cooler share one liquid inlet end 121 and one liquid outlet end 122, one three-way valve 17 is arranged at the branch of the main cooler and the auxiliary cooler, and one flow control valve 18 is arranged at the liquid inlet end 121. A switch is arranged on the circulating water type vacuum pump, which controls the communication path of the three-way valve through a control line. When the rotary evaporator 3 is running, the vacuum table 19 of the circulating water type vacuum pump 1 is observed, and when the vacuum degree of the reading decreases, the three-way valve 17 is adjusted so that the low-temperature cooling liquid flows into the internal flow channel 123 of the main cooler and the auxiliary cooler at the same time; the flow control valve 18 is adjusted to control the flow of the low-temperature cooling liquid flowing into the liquid inlet end 121; see Figure 6 .

[0075] The air suction port of the circulating water type vacuum pump 1 is connected to the vacuum air suction interface of the rotary evaporator through a vacuum pipe. The condenser 31 is a condensing pipe.

[0076] Specifically, the main cooler and the auxiliary cooler can select at least one of a cooling coil and a cooling disc.

[0077] In order to achieve better cooling effect in the limited accommodation space of the water tank, the shape of the cooling coil and the cooling disc can be optimized in combination with different structural forms, for example, at least one of the following characteristics is met:

[0078] (a) When the cooling coil is a spiral coil, the pitch p of the spiral coil is (1 / 45-1 / 35)H, and the winding diameter D is (3 / 5-4 / 5)×W; wherein H is the height of the water tank, and W is the minimum lateral dimension of the water tank in the plane perpendicular to the height thereof.

[0079] (b) When the cooling coil is a serpentine coil, or when the internal flow channel of the cooling disc has a serpentine flow channel, the bending radius R of the serpentine coil or the serpentine flow channel is ≥1.5d eq , and the maximum pitch S max =(1 / 2-3 / 4)W;

[0080] wherein d eq is the equivalent inner diameter of the coil or flow channel, and the equivalent inner diameter is defined as the inner diameter of a circular pipe or flow channel having the same cross-sectional area, and the maximum pitch S max is the distance between the most distant two flow channel center lines in the serpentine coil or serpentine flow channel, and W is the minimum lateral dimension of the water tank in the plane perpendicular to the height thereof.

[0081] (c) When the main body of the cooling device 12 is an equal-diameter cooling coil, the internal volume V2 of the cooling coil satisfies: V2=(1 / 55-1 / 45)V1, V2=S2×L2; wherein S2 is the inner cross-sectional area of the cooling coil, L2 is the total length of the cooling coil, and V1 is the volume of the accommodation space formed between the water tank 11 and the immersion assembly 16.

[0082] (d) When the main body of the cooling device 12 is a cooling coil, the aspect ratio of the cooling coil is in the range of: d eq / L=(1 / 600-1 / 400), and d eq is the equivalent inner diameter of the coil, and the equivalent inner diameter is defined as the inner diameter of a circular coil having the same cross-sectional area.

[0083] (e) When the main body of the cooling device 12 is a cooling disc, the cooling disc has an internal flow channel and the internal flow channel is equal-diameter, and the total volume V3 of the internal flow channel is (1 / 150-1 / 200)V1, V3=S3×L3, S3 is the cross-sectional area of the internal flow channel, L3 is the total length of the internal flow channel, and V1 is the volume of the accommodation space formed between the water tank 11 and the immersion assembly 16.

[0084] (f) When the main body of the cooling device 12 is a cooling disc with an internal flow channel, the ratio of S3 to L3 is 1 / 30-1 / 20, S3 is the cross-sectional area of the internal flow channel, and L3 is the total length of the internal flow channel.

[0085] (g) When the main body of the cooling device 12 is a cooling disc with an internal flow channel, the ratio of h to H is (3 / 5-4 / 5), h is the height of the internal flow channel (in the direction of the thickness of the disc), and H is the thickness of the cooling disc; the above ratio ensures the mechanical strength of the cooling disc while obtaining better heat exchange effect, so that the cooling disc has higher cooling capacity per unit volume.

[0086] In some embodiments, referring to Figure 5 , the length and the width of the cooling disc are not equal, and in this case, when the internal flow channel 123 is a serpentine, the arrangement of the serpentine flow channel in the cooling disc 12 includes but is not limited to one of the following two arrangements: (a) the serpentine flow channel is mainly arranged in the width direction of the cooling disc, and the flow channel is folded back multiple times in the width direction; (b) the serpentine flow channel is mainly arranged in the length direction of the cooling disc, and the flow channel is folded back multiple times in the length direction.

[0087] Exemplarily, the cooling disc tube is a copper disc tube. The cooling disc is a stainless steel disc. The cooling disc is arranged parallel to the bottom of the water tank, and the circumferential side of the cooling disc is parallel to the inner wall of the water tank, i.e., the cooling disc is designed to follow the shape of the water tank, so as to improve the space utilization and obtain better cooling effect.

[0088] The above description is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A rotary evaporation system with an improved circulating water vacuum pump, characterized in that, The circulating water vacuum pump (1), the low-temperature circulating device (2) and the rotary evaporator (3) are connected in series. The circulating water vacuum pump (1) comprises a water tank (11), wherein a cooling device (12) is arranged in the water tank (11), the main body of the cooling device (12) is fixed and installed in the water tank by a support, the main body of the cooling device (12) extends out a liquid inlet end (121) comprising a first liquid inlet (121a) and a liquid outlet end (122) comprising a first liquid outlet (122b), and the liquid inlet end (121) and the liquid outlet end (122) are sealingly installed on the tank wall of the water tank by a connecting piece. The low-temperature circulating device (2) comprises a second liquid inlet (2a) and a second liquid outlet (2b). The rotary evaporator (3) comprises a condenser (31), and the two ends of the condenser are respectively provided with a third liquid inlet (31a) and a third liquid outlet (31b). The second liquid outlet (2b) of the low-temperature circulating device (2) is connected with the third liquid inlet (31a) of the rotary evaporator (3), the third liquid outlet (31b) of the rotary evaporator is connected with the first liquid inlet (121a) of the circulating water vacuum pump (1), and the first liquid outlet (122b) of the circulating water vacuum pump (1) is connected with the second liquid inlet (2a) of the low-temperature circulating device (2).

2. The rotary evaporation system of claim 1, wherein, The main body of the cooling device (12) comprises at least one of a cooling coil or a cooling disc, and the cooling disc is provided with an internal flow channel.

3. The rotary evaporation system of claim 2, wherein, The support comprises a fixed column (13), one end of the fixed column (13) is connected to a fixed base (14) installed on the inner surface of the bottom of the water tank (11), the other end extends upward away from the bottom of the water tank (11), and the top and / or the peripheral side of the fixed column (13) is fixedly connected with the cooling device (12); and the fixed column (13) is one or more.

4. The rotary evaporation system of claim 2, wherein, The connecting piece comprises two flanges (15) sealingly installed at different positions of the tank wall of the water tank (11); and the inner hole of each flange (15) is sealingly connected with the outer wall of the liquid inlet end (121) or the liquid outlet end (122) of the cooling device by a sealing piece or a thread.

5. The rotary evaporation system of claim 2, wherein, The circulating water vacuum pump (1) further comprises a pump body, and the part of the pump body immersed in the water tank (11) is referred to as an immersion assembly (16); and the cooling device (12) is installed in the accommodation space formed between the water tank (11) and the immersion assembly (16).

6. The rotary evaporation system of claim 5, wherein, The cooling coil is a spiral coil or a serpentine coil, which is arranged below and / or on one side of and / or around the immersion assembly (16); and / or The cooling disc is a disc-shaped plate, which is a disc-shaped plate without a through hole or a disc-shaped plate with a through hole; wherein the through hole is used to accommodate the immersion assembly (16) so that the disc-shaped plate with the through hole is arranged around the immersion assembly (16); and the disc-shaped plate without the through hole is arranged below or on one side of the immersion assembly (16).

7. The rotary evaporation system of claim 6, wherein, The serpentine coil or the disc-shaped plate is arranged horizontally parallel to the bottom of the water tank; and / or The cooling coil is a finned tube.

8. The rotary evaporation system of claim 1, wherein, The main body of the cooling device is formed by the main cooler and the auxiliary cooler in parallel, the main cooler and the auxiliary cooler share one liquid inlet end and one liquid outlet end, one three-way valve (17) is arranged at the flow separation of the main cooler and the auxiliary cooler, and one flow control valve (18) is arranged at the liquid inlet end.

9. The rotary evaporation system of claim 7, wherein, When the cooling coil is a spiral coil, the pitch p of the spiral coil is (1 / 45-1 / 35)H, and the winding diameter D is (3 / 5-4 / 5)W; wherein H is the height of the water tank, and W is the minimum lateral dimension of the water tank in the plane perpendicular to the height of the water tank; and / or, When the cooling coil is a serpentine coil, or when the cooling coil has an internal flow channel that is a serpentine flow channel, the bending radius R of the serpentine coil or the serpentine flow channel is ≥ 1.5d eq , the maximum pitch S max = (1 / 2 - 3 / 4)W; where d eq is the equivalent inner diameter of the coil or flow channel, defined as the inner diameter of a circular pipe or flow channel having the same cross-sectional area, the maximum pitch S max is the distance between the farthest two flow channel centerlines in a serpentine coil or serpentine flow channel, and W is the minimum lateral dimension of the water tank in a plane perpendicular to its height.

10. The rotary evaporation system of claim 5, wherein, When the main body of the cooling device (12) is a cooling coil with equal diameter, the internal volume V2 of the cooling coil satisfies: V2=(1 / 55-1 / 45)V1, V2=S2*L2; Wherein, S2 is the cross-sectional area of the cooling coil, L2 is the total length of the cooling coil, and V1 is the volume of the accommodation space formed between the water tank and the immersion assembly; or, When the main body of the cooling device (12) is a cooling disc, the cooling disc has an internal flow channel, the internal flow channel is of equal diameter, the total volume V3 of the internal flow channel satisfies: V3=(1 / 150-1 / 200)V1, V3=S3*L3, S3 is the cross-sectional area of the internal flow channel, L3 is the total length of the internal flow channel, and V1 is the volume of the accommodation space formed between the water tank and the immersion assembly.

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