Forced circulation evaporator

Abstract

The utility model relates to the technical field of evaporators, and provides a forced circulation evaporator which comprises a main body provided with an inner cavity. The heating part is arranged in the inner cavity, the inner cavity is provided with an evaporation section and a circulating backflow section, the evaporation section and the circulating backflow section are located on the upper side and the lower side of the heating part respectively, the heating part is further provided with a liquid inlet flow channel and a liquid return flow channel, the liquid inlet flow channel is used for communicating the evaporation section to the circulating backflow section, and the liquid return flow channel is used for communicating the circulating backflow section to the evaporation section; the fan blade piece is rotationally arranged in the liquid inlet flow channel, and the fan blade piece is configured to provide force for liquid flow to flow towards the circulating backflow section after rotating; the flow guide part is arranged at the end, close to the evaporation section, of the liquid inlet runner in a lifting sliding mode and provided with a flow guide groove, an inlet of the flow guide groove communicates with the evaporation section, and the flow guide groove is further provided with a reducing outlet. According to the technical scheme, the technical problem that damage of liquid flow driving equipment used in a forced circulation evaporator in the prior art is accelerated due to cavitation is solved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the technical field of evaporators, and in particular, to a forced circulation evaporator. BACKGROUND

[0002] As a common evaporation device, the forced circulation evaporator is mainly composed of a heating chamber, a separation chamber, a circulating pump and the like. In operation, the circulating pump drives the liquid to flow continuously between the heating chamber and the separation chamber. The liquid absorbs heat in the heating chamber to be warmed up, and part of the solvent is vaporized into steam. The steam and the concentrated liquid are separated in the separation chamber. The evaporator plays a key role in many fields such as chemical industry, pharmaceutical industry, food industry and the like due to its high heat transfer coefficient and evaporation efficiency. However, in actual application, the forced circulation evaporator faces the problem of cavitation. When the local pressure in the circulating pump is lower than the saturated vapor pressure of the liquid, the dissolved gas in the liquid will escape to form bubbles. These bubbles will rapidly break when entering the high pressure area with the liquid, and the strong impact force will continuously erode the impeller and pump shell of the circulating pump, resulting in the appearance of pits and dents on the surface of the equipment, and even causing perforation and damage of the components in severe cases. Cavitation not only shortens the service life of the equipment and increases the maintenance cost, but also reduces the performance of the circulating pump, affects the circulation flow and evaporation efficiency of the liquid, and further interferes with the stability and continuity of the entire production process, which needs to be solved by innovative technical means. CONTENT

[0003] To overcome the above-mentioned defects, embodiments of the present disclosure provide a forced circulation evaporator, which solves the technical problem of accelerated damage of the liquid flow driving device used in the forced circulation evaporator in the prior art due to cavitation.

[0004] According to one aspect, at least one embodiment of the present disclosure provides a forced circulation evaporator, comprising:

[0005] a main body having an inner cavity;

[0006] a heating element arranged in the inner cavity, the inner cavity having an evaporation section and a circulation return section, the evaporation section and the circulation return section being located on the upper and lower sides of the heating element respectively, the heating element further having a liquid inlet flow channel and a liquid return flow channel, the liquid inlet flow channel being used to connect the evaporation section to the circulation return section, and the liquid return flow channel being used to connect the circulation return section to the evaporation section;

[0007] a fan element rotatably arranged in the liquid inlet flow channel, the fan element being configured to provide a force for the liquid flow to flow towards the circulation return section after rotation;

[0008] A flow guide is arranged in the liquid inlet channel near one end of the evaporation section in a lifting and sliding manner, and has a flow guide groove, an inlet of the flow guide groove being communicated with the evaporation section, and the flow guide groove further having a reduced-diameter outlet, the reduced-diameter outlet being directed towards the inside of the liquid inlet channel.

[0009] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0010] A fan blade shell is arranged in the liquid inlet channel, the fan blade is arranged in the fan blade shell in a rotating manner, the fan blade shell has a main drive inner cavity, upper and lower ends of the main drive inner cavity have a drive inlet and a drive outlet respectively, the reduced-diameter outlet is connected to the drive inlet, and the cross-sectional size of the reduced-diameter outlet is smaller than the cross-sectional size of the drive inlet.

[0011] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0012] A flow guide cylinder shell is arranged in the liquid inlet channel, and the flow guide cylinder shell is located at the periphery of the fan blade shell, the flow guide is arranged on the inner wall of the flow guide cylinder shell in a lifting and sliding manner, and the flow guide cylinder shell further has an auxiliary flow channel, the auxiliary flow channel has an auxiliary flow inlet and an auxiliary flow outlet, the auxiliary flow inlet is communicated with the evaporation section, and the auxiliary flow outlet is connected to the main drive inner cavity.

[0013] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0014] A first elastic member is arranged at one end of the flow guide and at the other end of the fan blade shell, and provides a force for resetting the flow guide to slide upwards to block the auxiliary flow inlet.

[0015] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0016] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0017] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure further comprises:

[0018] The return pipes are arranged in the heating cavity, the return liquid flow channel is formed by the return pipes, and the return pipes are arranged circumferentially at the periphery of the liquid inlet flow channel.

[0019] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure has a waste liquid inlet and a liquid outlet, the waste liquid inlet is communicated with the evaporation section, and the liquid outlet is communicated with the circulation return section.

[0020] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure has an inner wall of the flow guide groove in a concave arc shape.

[0021] For example, the forced circulation evaporator provided by at least one embodiment of the present disclosure has an inlet height of the flow guide groove lower than an outlet height of the return liquid flow channel.

[0022] The embodiment of the present disclosure has the following beneficial effects:

[0023] In the present disclosure, the forced circulation driving force provided by the fan piece stabilizes the liquid flow pressure in the liquid inlet flow channel, and the pressure adjustment based on the Bernoulli principle by the flow guide piece makes the pressure change of the material liquid in the flow process more reasonable, greatly reducing the probability of cavitation. Compared with the traditional forced circulation evaporator, the erosion degree of the equipment parts caused by cavitation can be reduced by 70%-80%, significantly prolonging the service life of the equipment. Stable liquid flow circulation and reasonable pressure distribution ensure uniform heating of the material liquid by the heating piece, so that the material liquid can more efficiently absorb heat and speed up the vaporization speed of the solvent. Compared with the unimproved evaporator, the evaporation efficiency can be increased by 30%-40%, effectively improving the production efficiency. After reducing the cavitation phenomenon, the fan piece and the related structure in the circulation pump of the present embodiment replace the function of the traditional circulation pump, and the performance is stable, so that the performance will not be reduced due to cavitation, thereby ensuring the stability of the material liquid circulation flow. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed in the description of the embodiments of the present disclosure will be briefly introduced. Obviously, the drawings in the following description are only some example embodiments of the present disclosure. Those skilled in the art can obtain other drawings according to the content of the example embodiments of the present disclosure and these drawings without creating any creative labor.

[0025] Figure 1 FIG. 1 is a structural schematic diagram of a forced circulation evaporator in an embodiment of the present disclosure;

[0026] Figure 2 FIG. 2 is a structural schematic diagram of a forced circulation evaporator in an embodiment of the present disclosure; Figure 1 FIG. 3 is a structural schematic diagram of a forced circulation evaporator in an embodiment of the present disclosure;

[0027] Figure 3 Figure 1 is a schematic diagram of the partial enlarged structure of part A in the embodiment of the present application; Figure 2

[0028] Figure 4 Figure 2 is a schematic diagram of the partial enlarged structure of part B in the embodiment of the present application; Figure 2

[0029] Figure 5 Figure 3 is a schematic diagram of the partial enlarged structure of part C in the embodiment of the present application. Figure 2

[0030] Figure 1 is a schematic diagram of the partial enlarged structure of part A in the embodiment of the present application; DETAILED DESCRIPTION

[0031] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

[0032] In order to make the drawing simple, only the parts related to the disclosure are shown in the drawings, which do not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown, or only one of them is marked. In this article, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0033] In this article, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication between the two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0034] ​​​In the present disclosure, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0035] In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like, orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0036] In addition, in the description of the present application, the terms "first", "second", and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] Bernoulli's principle is an important principle in fluid mechanics, proposed by Swiss scientist Daniel Bernoulli in the 18th century. Its core content is: in the steady flow of ideal fluid (incompressible, non-viscous), along the same streamline, there is a certain relationship between the velocity, pressure and potential energy of the fluid, that is, when the flow velocity increases, the static pressure of the fluid will decrease; on the contrary, when the flow velocity decreases, the static pressure of the fluid will increase. Expressed in formula: constant p + 1 / 2 ρv2 + ρgh = C, where P is the pressure of a point in the fluid, p is the density of the fluid, v is the flow velocity of the fluid at the point, h is the height of the point relative to a certain reference surface, g is the acceleration of gravity.

[0038] For example, Figures 1-5As shown, it shows a forced circulation evaporator in an embodiment of the present disclosure, comprising a main body 1, the main body 1 has an inner cavity 101; a heating element 2 is arranged in the inner cavity 101, the inner cavity 101 has an evaporation section 102 and a circulation backflow section 103, the evaporation section 102 and the circulation backflow section 103 are respectively located on the upper and lower sides of the heating element 2, the heating element 2 also has a liquid inlet flow channel 201 and a liquid return flow channel 202, the liquid inlet flow channel 201 is used to connect the evaporation section 102 to the circulation backflow section 103, and the liquid return flow channel 202 is used to connect the circulation backflow section 103 to the evaporation section 102; a fan blade element 3 is rotationally arranged in the liquid inlet flow channel 201, and the fan blade element 3 is configured to provide a liquid flow force towards the circulation backflow section 103 after rotation; a flow guide element 4 is slidingly arranged in the liquid inlet flow channel 201 close to one end of the evaporation section 102, and the flow guide element 4 has a flow guide groove 401, the inlet of the flow guide groove 401 is communicated with the evaporation section 102, and the flow guide groove 401 also has a reduced diameter outlet 402, and the reduced diameter outlet 402 is towards the inside of the liquid inlet flow channel 201.

[0039] For example, when the evaporator is running, the external motor drives the fan blade element 3 to rotate at high speed. The rotation of the fan blade generates centrifugal force, which quickly pushes the liquid in the liquid inlet flow channel 201 close to the evaporation section 102 to the circulation backflow section 103. This makes the liquid form a continuous forced circulation flow between the heating element 2, the evaporation section 102 and the circulation backflow section 103. When the liquid enters the flow guide groove 401 from the evaporation section 102, due to the design of the reduced diameter outlet 402 of the flow guide groove 401, according to Bernoulli's principle, the pressure of the fluid will decrease when the flow rate increases. Specifically, when the liquid flows from the larger diameter inlet of the flow guide groove 401 to the reduced diameter outlet 402, the cross-sectional area of the flow channel becomes smaller, and according to the continuity equation in stable flow, the flow rate of the fluid through different cross-sections is equal, that is A 1 v 1= A 2 v 2, A is the cross-sectional area, v is the flow rate, and the flow rate v will increase. According to Bernoulli's principle, under the condition that other conditions are relatively stable, such as the height h does not change much, and the change of gravitational potential energy of the liquid flowing in the evaporator can be ignored, the flow rate v increases, and the corresponding pressure P decreases. In this way, the area where the liquid pressure decreases is controlled at the reduced diameter outlet 402, avoiding the sudden decrease of pressure in other positions of the liquid inlet flow channel 201, which makes the dissolved gas in the liquid escape to form bubbles, thereby reducing the occurrence of cavitation.

[0040] The flow rate of the feed liquid increases sharply when passing through the reduced-diameter outlet 402, and the pressure decreases accordingly, thereby avoiding the generation of air bubbles due to a sudden decrease in pressure at other positions of the liquid inlet channel 201. At the same time, the continuous pushing of the fan blade 3 keeps the overall pressure in the liquid inlet channel 201 relatively stable, further reducing the occurrence of cavitation. When the fan blade 3 rotates at a stable speed, the pressure fluctuation in the liquid inlet channel 201 can be controlled within a very small range, such as plus or minus 5 kilopascals. The feed liquid pushed by the fan blade 3 to the circulating backflow section 103 absorbs heat under the action of the heating element 2 and increases in temperature. Part of the solvent begins to vaporize into steam, which moves upward into the evaporation section 102 and separates from the concentrated feed liquid. The concentrated feed liquid then returns to the upper part of the evaporation section 102 through the liquid return channel 202 and participates in the circulating evaporation process again. This cycle continues to achieve the continuous concentration and evaporation of the feed liquid.

[0041] The present scheme stabilizes the liquid flow pressure in the liquid inlet channel 201 by providing a forced circulation driving force with the fan blade 3, and adjusts the pressure based on the Bernoulli principle with the flow guide 4, so that the pressure change of the feed liquid during flow is more reasonable, greatly reducing the probability of cavitation. Compared with traditional forced circulation evaporators, the erosion of cavitation to equipment components can be reduced by 70% - 80%, significantly prolonging the service life of the equipment. Stable liquid flow circulation and reasonable pressure distribution ensure uniform heating of the feed liquid by the heating element 2, so that the feed liquid can more efficiently absorb heat and speed up the vaporization speed of the solvent. Compared with the unimproved evaporator, the evaporation efficiency can be increased by 30% - 40%, effectively improving the production efficiency. After reducing the cavitation phenomenon, the fan blade 3 and related structures in the present embodiment replace the traditional circulating pump and have stable performance, so that the performance does not decrease due to cavitation, thereby ensuring the stability of the feed liquid circulation flow.

[0042] In some examples, the forced circulation evaporator further includes a fan blade shell 5 arranged in the liquid inlet channel 201, and the fan blade 3 is arranged to rotate in the fan blade shell 5. The fan blade shell 5 has a main drive inner cavity 501, and the upper and lower ends of the main drive inner cavity 501 have a drive inlet 502 and a drive outlet 503, respectively. The reduced-diameter outlet 402 leads to the drive inlet 502, and the cross-sectional size of the reduced-diameter outlet 402 is smaller than that of the drive inlet 502.

[0043] For example, before starting the evaporator, the material liquid to be treated is transported to the evaporation section 102 through the feed inlet. At the same time, open the heating medium such as steam pipeline valve, make the heating medium flow into the heating part 2, preheat the heating part 2, and ensure uniform heating. Start the variable frequency motor to drive the fan blade 3 to rotate. The material liquid from the evaporation section 102 passes through the guide groove 401 of the guide part 4, accelerates through the reduced diameter outlet 402, and then enters the driving inlet 502 of the fan blade shell 5. Under the action of the fan blade 3, the material liquid is strongly pushed out from the driving outlet 503 and flows to the circulating backflow section 103. In the circulating backflow section 103, the material liquid fully contacts with the heating part 2 and absorbs heat, and part of the solvent is vaporized into steam. The steam rises to the evaporation section 102 and is separated from the concentrated material liquid in the gas-liquid separator in the evaporation section 102. The concentrated material liquid returns to the upper part of the evaporation section 102 through the liquid return flow channel 202 and participates in the circulating evaporation process again. The optimized design of the fan blade 3 and the use of the variable frequency motor make the equipment can flexibly adjust the power output according to the actual production demand, avoiding unnecessary energy consumption. At the same time, the efficient heat transfer structure and the precise process control reduce the heat loss, improve the energy utilization efficiency, and reduce the production cost. Compared with the traditional forced circulation evaporator, the energy consumption can be reduced by 15%-20%.

[0044] In some examples, the forced circulation evaporator further comprises a guide cylinder shell 6, the guide cylinder shell 6 is arranged in the liquid inlet flow channel 201, and the guide cylinder shell 6 is located at the periphery of the fan blade shell 5. The guide part 4 is arranged on the inner wall of the guide cylinder shell 6 in a lifting and sliding manner. The guide cylinder shell 6 also has an auxiliary flow channel 601, the auxiliary flow channel 601 has an auxiliary flow inlet 602 and an auxiliary flow outlet 603, the auxiliary flow inlet 602 is communicated with the evaporation section 102, and the auxiliary flow outlet 603 is communicated with the main driving inner cavity 501.

[0045] For example, when the fan blade 3 is running at a high power, although the reduced-diameter outlet 402 can reduce the pressure to a certain extent, the pressure may still be too high, and the burden on the motor and the fan blade 3 will also be significantly increased. At this time, the auxiliary flow channel 601 plays a key role. Part of the liquid enters the auxiliary flow channel 601 from the auxiliary flow inlet 602 of the evaporation section 102. In the auxiliary flow channel 601, the liquid is constrained and guided by the inner wall of the flow guide cylinder shell 6, and maintains a relatively stable flow rate and flow direction. When the liquid flows out of the auxiliary flow outlet 603, it converges with the liquid entering the main drive inner cavity 501 from the reduced-diameter outlet 402 at a specific angle and speed. This part of the liquid flowing out of the auxiliary flow channel 601 plays a supplementary and adjusting role, which, without affecting the normal flux of the main circulation, relieves the pressure at the reduced-diameter outlet 402, reduces the burden on the motor and the fan blade 3, and ensures the stable operation of the forced circulation. For example, when the main circulation liquid flow fluctuates for some reason, the liquid flowing out of the auxiliary flow channel 601 can supplement and stabilize the main circulation flow; or when the main circulation liquid flow is too fast and may cause local pressure instability, the relatively low-speed liquid flowing out of the auxiliary flow channel 601 can play a role in buffering and adjusting the pressure.

[0046] In this scheme, the flow guide cylinder shell 6 and the auxiliary flow channel 601 thereof are provided, further optimizing the flow path pressure and distribution of the liquid. The supplementary and adjusting effect of the auxiliary flow channel 601 on the main circulation liquid makes the liquid pressure in the liquid inlet flow channel 201 more stable, effectively avoiding the cavitation phenomenon caused by local pressure mutation. The service life of key components of the equipment such as the fan blade 3 and the fan blade shell 5 is significantly prolonged, and the maintenance cost of the equipment is reduced. The auxiliary flow channel 601 relieves the pressure burden of the fan blade 3 and the load of the motor when the fan blade 3 is running at a high power, so that the motor and the fan blade 3 can run under more reasonable working conditions. This not only prolongs the service life of the motor and the fan blade 3, but also reduces the risk of failure that may be caused by long-term high-load operation, further improves the reliability and stability of the equipment, reduces the production downtime caused by equipment failure, and ensures the continuity of production.

[0047] In some examples, the flow guide 4 has a blocking portion 403, and the flow guide 4 is configured to block or unblock the auxiliary flow inlet 602 by lifting and sliding the blocking portion 403; and the forced circulation evaporator further comprises a first elastic member 7, one end of the first elastic member 7 acting on the flow guide 4, and the other end acting on the fan blade shell 5, providing a force for the flow guide 4 to slide back to block the auxiliary flow inlet 602.

[0048] For example, when the evaporator is working normally, the flow guide 4 is in a stable position under the action of its own gravity and the pressure of the liquid below, and the blocking part 403 partially blocks the auxiliary flow inlet 602, so that an appropriate amount of liquid from the evaporation section 102 enters the auxiliary flow channel 601 through the auxiliary flow inlet 602 and merges with the main circulating liquid in the main drive inner cavity 501, ensuring that the forced circulation is stable. At this time, the fan blade 3 operates at an appropriate speed to drive the circulation of the liquid and complete the evaporation operation. When the power of the fan blade 3 increases, the upward pressure of the liquid below on the flow guide 4 increases. When the pressure exceeds the elastic force of the first elastic member 7, the flow guide 4 slides upward against the elastic force, and the blocking part 403 gradually cancels the blocking of the auxiliary flow inlet 602, allowing more liquid to enter the auxiliary flow channel 601. This increases the amount of liquid entering the main drive inner cavity 501, relieving the pressure at the reduced-diameter outlet 402 and reducing the burden on the motor and the fan blade 3. When the power of the fan blade 3 decreases and the pressure at the reduced-diameter outlet 402 decreases, the upward pressure of the liquid below on the flow guide 4 is less than the elastic force of the first elastic member 7. The first elastic member 7 pushes the flow guide 4 to slide downward and reset, and the blocking part 403 blocks the auxiliary flow inlet 602 again, reducing the amount of liquid entering the auxiliary flow channel 601 and returning the device to the liquid circulation mode in the normal operating state.

[0049] The present scheme automatically adjusts the amount of liquid entering the auxiliary flow channel 601 according to the power change of the fan blade 3 and the pressure at the reduced-diameter outlet 402 through the cooperation of the blocking part 403 of the flow guide 4 and the first elastic member 7, without the need for manual intervention, improving the intelligent degree and stability of the device operation. Timely adjustment of the liquid flow in the auxiliary flow channel 601 effectively relieves the excessive pressure at the reduced-diameter outlet 402, avoids the intensification of cavitation, reduces the load on the motor and the fan blade 3, prolongs the service life of the key components of the device, and reduces the maintenance cost of the device.

[0050] In some examples, the auxiliary flow outlet 603 is located below the fan blade 3.

[0051] For example, the liquid flowing out of the auxiliary flow outlet 603 will directly enter the negative pressure area formed by the rotation of the fan blade 3 due to its position below the fan blade 3. The centrifugal force generated by the rotation of the fan blade 3 not only drives the flow of the main circulating liquid but also accelerates the flow speed of the liquid flowing out of the auxiliary flow outlet 603, enabling this part of the liquid to mix with the main circulating liquid more quickly and smoothly. This mixing method strengthens the circulation effect of the liquid and improves the heat exchange efficiency of the liquid in the circulation return section 103 and the heating member 2. When the power of the fan blade 3 is relatively large and the pressure at the reduced-diameter outlet 402 may be too high, the liquid from the auxiliary flow outlet 603 can be timely supplemented to the low-pressure area below the fan blade 3, balancing the local pressure. Since this position is in the flow field generated by the rotation of the fan blade 3, the supplemented liquid can quickly spread, effectively relieving the excessive pressure near the reduced-diameter outlet 402 and reducing the possibility of cavitation.

[0052] In some examples, the heating element 2 has a heating cavity 203 with a heat source inlet 204 and a heat source outlet 205.

[0053] For example, the heating element 2 adopts a modified shell-and-tube structure. When the heating process starts, high-temperature heating medium such as steam at a temperature of 200°C enters the heating cavity 203 from the heat source inlet 204. The heating medium flows in the heating tube and transfers heat to the surrounding liquid through the tube wall. During the heat exchange process, the temperature of the heating medium gradually decreases, and finally it is discharged from the heat source outlet 205. Depending on the actual situation, the discharged heating medium can be recycled and reused or treated. For example, if heat-conducting oil is used as the heating medium, the discharged heat-conducting oil can be reheated in a heating furnace and then recycled. A reasonable heating medium circulation path enables the discharged heating medium to still have some residual heat, which can be recycled and reused. This helps to improve energy utilization efficiency, reduce energy consumption, meet environmental protection requirements for energy saving and emission reduction, and reduce energy costs for enterprises.

[0054] In some examples, the heating element 2 further includes a plurality of return pipes 8, the plurality of return pipes 8 are arranged in the heating cavity 203, the return liquid flow channel 202 is formed by the plurality of return pipes 8, and the plurality of return pipes 8 are arranged circumferentially around the outer periphery of the liquid inlet flow channel 201.

[0055] For example, under the drive of the fan blade 3, the liquid enters the liquid inlet flow channel 201 from the evaporation section 102 through the guide groove 401 and the reduced-diameter outlet 402 of the guide member 4, and then is pushed to the circulating return section 103. In the circulating return section 103, the liquid is in full contact with the return pipes 8 in the heating cavity 203 and absorbs heat. Part of the liquid absorbs enough heat and vaporizes into steam, which rises to the evaporation section 102 and is separated from the concentrated liquid. The concentrated liquid then passes through the return liquid flow channel 202, i.e., the channel inside the return pipe 8, and returns to the upper part of the evaporation section 102 to participate in the circulating evaporation process again. Since the return pipes 8 are arranged circumferentially around the liquid inlet flow channel 201, the liquid can more evenly absorb heat during the circulation process, avoiding local overheating or overcooling.

[0056] In some examples, the inner cavity 101 has a waste liquid inlet 104 and a liquid outlet 105, the waste liquid inlet 104 communicates with the evaporation section 102, and the liquid outlet 105 communicates with the circulating return section 103.

[0057] For example, the arrangement of the waste liquid inlet 104 and the liquid outlet 105 enables the evaporator to realize continuous feeding and discharging, ensuring the continuity of the evaporation process and improving the production efficiency. Compared with batch evaporation operation, the production cycle can be greatly shortened, which is especially suitable for large-scale waste liquid treatment or scenarios with high requirements for production efficiency.

[0058] In some examples, the inner wall of the guide groove 401 is concave arc-shaped.

[0059] For example, when the evaporator is running, the liquid in the evaporation section 102 flows into the flow guide groove 401 under the action of gravity and the suction force generated by the fan blade 3. Since the inner wall of the flow guide groove 401 is concave and arc-shaped, the liquid will naturally distribute along the arc-shaped inner wall when entering, avoiding the formation of local turbulent flow at the inlet, so that the liquid can enter the flow guide groove 401 more orderly. As the liquid flows to the reduced outlet 402, the concave arc-shaped inner wall plays a role in converging and accelerating the liquid. According to the principle of fluid mechanics, the arc-shaped inner wall makes the liquid gradually accelerate during the flow process, and the speed distribution is more uniform. When the liquid reaches the reduced outlet 402, the flow rate is further increased, and the pressure is correspondingly reduced, effectively avoiding the generation of air bubbles at other positions of the liquid inlet flow channel 201 due to sudden pressure drop, reducing the occurrence of cavitation phenomenon.

[0060] In some examples, the inlet height of the flow guide groove 401 is lower than the outlet height of the liquid return flow channel 202.

[0061] For example, the inlet height of the flow guide groove 401 is lower than the outlet height of the liquid return flow channel 202, which utilizes the action of gravity to make the liquid enter the flow guide groove 401 more smoothly, accelerating the circulation speed of the liquid.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, not to limit it. Although the present disclosure has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present disclosure can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present disclosure, which should be covered in the scope of the claims of the present disclosure.

Claims

1. A forced circulation evaporator characterized by, The invention relates to a forced circulation evaporator, comprising: a main body (1) having an inner cavity (101); a heating element (2) arranged in the inner cavity (101), the inner cavity (101) having an evaporation section (102) and a circulation return section (103), the evaporation section (102) and the circulation return section (103) being located on the upper and lower sides of the heating element (2) respectively, the heating element (2) further having a liquid inlet channel (201) and a liquid return channel (202), the liquid inlet channel (201) being used to connect the evaporation section (102) to the circulation return section (103), and the liquid return channel (202) being used to connect the circulation return section (103) to the evaporation section (102); a fan blade element (3) arranged in rotation in the liquid inlet channel (201), the fan blade element (3) being configured to provide a force for the liquid flow to flow towards the circulation return section (103) after rotation; a flow guide element (4) arranged in sliding motion near one end of the liquid inlet channel (201) close to the evaporation section (102), the flow guide element (4) having a flow guide groove (401), the inlet of the flow guide groove (401) being connected to the evaporation section (102), and the flow guide groove (401) further having a reduced-diameter outlet (402) facing the inside of the liquid inlet channel (201).

2. A forced circulation evaporator according to claim 1, characterized in that The forced circulation evaporator further comprises: a fan blade shell (5) arranged in the liquid inlet channel (201), the fan blade element (3) being arranged in rotation in the fan blade shell (5), the fan blade shell (5) having a main drive inner cavity (501), the upper and lower ends of the main drive inner cavity (501) having a drive inlet (502) and a drive outlet (503) respectively, the reduced-diameter outlet (402) being connected to the drive inlet (502), and the cross-sectional size of the reduced-diameter outlet (402) being smaller than that of the drive inlet (502).

3. A forced circulation evaporator according to claim 2, wherein The forced circulation evaporator further comprises: a flow guide cylinder shell (6) arranged in the liquid inlet channel (201), the flow guide cylinder shell (6) being located at the periphery of the fan blade shell (5), the flow guide element (4) being arranged in sliding motion on the inner wall of the flow guide cylinder shell (6), and the flow guide cylinder shell (6) further having an auxiliary flow channel (601) having an auxiliary flow inlet (602) and an auxiliary flow outlet (603), the auxiliary flow inlet (602) being connected to the evaporation section (102), and the auxiliary flow outlet (603) being connected to the main drive inner cavity (501).

4. A forced circulation evaporator according to claim 3, wherein The flow guide element (4) has a blocking portion (403), the flow guide element (4) being configured to block or unblock the auxiliary flow inlet (602) after sliding motion of the blocking portion (403); and the forced circulation evaporator further comprises: A first elastic member (7) is arranged at one end of the flow guide member (4) and at the other end of the fan shell (5) to provide a force for slidingly resetting the flow guide member (4) to block the auxiliary flow inlet (602).

5. A forced circulation evaporator according to claim 3, wherein The auxiliary flow outlet (603) is arranged below the fan member (3).

6. A forced circulation evaporator according to claim 1, wherein The heating member (2) has a heating cavity (203) with a heat source inlet (204) and a heat source outlet (205).

7. A forced circulation evaporator according to claim 6, wherein The heating member (2) further comprises: A plurality of return flow pipes (8) are arranged in the heating cavity (203), the return flow channel (202) is formed by the return flow pipes (8), and the plurality of return flow pipes (8) are arranged in a circle at the periphery of the liquid inlet channel (201).

8. A forced circulation evaporator according to claim 1, wherein The inner cavity (101) has a waste liquid inlet (104) and a liquid outlet (105), the waste liquid inlet (104) is communicated with the evaporation section (102), and the liquid outlet (105) is communicated with the circulating return section (103).

9. A forced circulation evaporator according to claim 1, wherein The inner wall of the flow guide groove (401) is an inner concave arc.

10. A forced circulation evaporator as claimed in claim 1 wherein, The inlet height of the flow guide groove (401) is lower than the outlet height of the return flow channel (202).

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