A urea production plant

Abstract

The present application relates to the technical field of urea production, in particular to a urea production device. The device comprises a mixing tank, a feeding hopper, a stirring device, a liquid inlet pipe and a liquid outlet pipe. An inner cylinder is arranged in the mixing tank. The inner cylinder divides the mixing tank into an inner mixing chamber for storing pre-mixed liquid and an outer mixing chamber for storing raw materials to be mixed. A filter screen is arranged above the inner cylinder. The filter screen uniformly disperses small-particle raw materials in the inner mixing chamber and guides large-particle raw materials into the outer mixing chamber. During the liquid separation stage, water waves generated by vortex rotation drive the floating plate to move up and down in the pre-mixed liquid, and the guide plate is driven to move up and down as well. The vortex outer ring solution at different depths is guided to the axis, thereby enhancing the mixing degree of the solution in the horizontal direction. During the liquid combination stage, the floating plate jumps up and lifts the vortex outer ring solution to a certain height by tilting, so as to impact the rear of the guide plate by using the gravitational potential energy, thereby further breaking the local concentration difference and promoting the solution to reach a more uniform mixing state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of urea production, in particular, to a urea production device. BACKGROUND

[0002] The mixing device for producing vehicle urea solution is a device for mixing high-purity urea and deionized water in a certain proportion, which is widely used in the production of vehicle urea solution used in SCR (selective catalytic reduction) system, which helps to reduce nitrogen oxides emitted by vehicles and meets environmental protection requirements.

[0003] The patent CN120079302A discloses a mixing device for producing vehicle urea solution, which belongs to the technical field of vehicle urea solution processing. The mixing device includes a mixing tank, a raw material barrel fixed on the top of the mixing tank through a support, a liquid input pipe fixed on the side wall of the raw material barrel, a conical inner wall bottom of the raw material barrel, and two feed pipes fixed between the top of the mixing tank and the bottom of the raw material barrel. The pretreatment device is provided to screen the urea raw material with the cooperation of the stirring blade rod, the flower disc, the arc block ring, and the contact rod driving the conical mesh cylinder. The smaller particles of urea will directly fall into the soft water, and the grinding teeth of the grinding roller and the conical mesh cylinder will grind and crush the larger particles of urea. The ground and crushed urea will fall into the soft water. By directly feeding the smaller particles of urea into the soft water and feeding the larger particles of urea after grinding and crushing, the crushing time is reduced.

[0004] Due to the vortex formed in the solution during the stirring process of the stirring plate, the urea particles are collected to the outer circle, resulting in differences in urea concentration in different areas of the solution. The urea concentration in the central area is lower, while the urea concentration in the outer circle area is too high, which cannot form a uniform mixed solution. Moreover, in the prior art, when filling urea particles, a hole is usually cut on the urea packaging bag, and urea particles are dropped into the solution while stirring, which will cause a large amount of urea particles to fall into the same area, cannot uniformly cover the solution, and reduces the mixing efficiency. SUMMARY

[0005] The present application provides a urea production device, which utilizes the water waves generated by vortex rotation to drive the floating plate to drive the drainage plate to float up and down in the pre-mixed liquid, and to guide the vortex outer circle solution at different depths to the axis, thereby enhancing the mixing degree of the solution in the horizontal direction. In the mixing stage, the floating plate jumps up and raises the height of the vortex outer circle solution by tilting, so as to utilize the gravitational potential energy to impact the rear of the drainage plate, thereby solving the problems raised in the above background technology, i.e.:

[0006] To achieve the above object, the urea production device comprises a mixing tank, a feeding hopper, a stirring device, a liquid inlet pipe and a liquid outlet pipe, an inner cylinder is arranged inside the mixing tank, the inner cylinder divides the mixing tank into an inner mixing chamber for storing pre-mixed liquid and an outer mixing chamber for storing raw materials to be mixed from inside to outside, a filter screen is arranged above the inner cylinder, the filter screen uniformly disperses small-particle raw materials in the inner mixing chamber, and large-particle raw materials are guided into the outer mixing chamber;

[0007] A flow limiting mechanism is arranged at the bottom of the inner mixing chamber, and a flow disturbing mechanism is symmetrically arranged on the inner side, in the liquid separation stage, the flow limiting mechanism releases the liquid in the inner mixing chamber, and the liquid pressure in the inner mixing chamber forms an impact on the raw materials to be mixed in the outer mixing chamber, so as to realize solid-liquid mixing, and the flow disturbing mechanism moves the solution at the inner wall of the inner cylinder to the axis by floating up and down; in the liquid mixing stage, the flow limiting mechanism separates the inner mixing chamber from the outer mixing chamber, and the flow disturbing mechanism forces the solution at the inner wall of the inner cylinder to jump and hit the rear solution in an inclined manner.

[0008] An outer flow port is symmetrically arranged below the inner wall of the inner cylinder and communicates the inner mixing chamber with the outer mixing chamber, and the outer flow port guides the pre-mixed liquid into the outer mixing chamber.

[0009] The flow limiting mechanism comprises a flow limiting plate arranged on the inner wall of the inner cylinder and corresponding to the outer flow port, in a normal state, the flow limiting plate is in a coincident state with the outer flow port, the flow limiting plate is used for plugging the outer flow port and limiting the pre-mixed liquid from flowing out, and in the liquid separation stage, the flow limiting plate is in a dislocation state with the outer flow port.

[0010] Further, the flow disturbing mechanism comprises a floating plate floating on the liquid surface of the pre-mixed liquid, and a flow guide plate rotationally connected to the bottom of the floating plate, the floating plate uses the waves formed by the liquid surface of the pre-mixed liquid as power to drive the flow guide plate to move up and down in the pre-mixed liquid, so as to disturb the pre-mixed liquid at different depths.

[0011] One side of the flow guide plate is slidingly connected with a guide rail fixed to the inner wall of the inner cylinder, the other side extends to the axis, and the end portion is inclined outward to form an outwardly inclined end, the outwardly inclined end is used for guiding the solution at the inner wall of the inner cylinder to the inner side, so that the solution at the outer circle of the vortex is mixed with the solution in the middle of the vortex.

[0012] The flow limiting mechanism further comprises a lever fixedly arranged on the inner side of the flow limiting plate, and the floating plate is located on the rotation path of the lever, the lever is used for rotating the floating plate and blocking the floating plate, so that one end of the floating plate is lifted from the liquid surface of the pre-mixed liquid, and the other end is immersed in the pre-mixed liquid.

[0013] Compared with the prior art, the urea production device has the following beneficial effects:

[0014] 1. In the separation stage, the water waves generated by the vortex rotation drive the floating plate to move up and down in the premixed liquid, allowing the solution in the outer ring of the vortex at different depths to be guided towards the axis, thus enhancing the mixing degree of the solution in the horizontal direction. Furthermore, in the mixing stage, the floating plate tilts to raise the solution in the outer ring of the vortex to a higher height, using gravitational potential energy to impact the back of the guide plate, further breaking down local concentration differences and promoting a more uniform mixing state of the solution.

[0015] 2. During feeding, the filter screen moves up and down to control the amount of material fed, achieving precise feeding and avoiding large-scale feeding at one time. At the same time, the raw materials are sorted by the filter screen. Small particles slide along the filter screen and are evenly dispersed in the solution, while large particles are guided to the external mixing chamber for storage, thereby preventing uneven mixing caused by agglomeration of raw materials. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a front view of the internal structure of the mixing tank and inner cylinder of the present invention (cut section).

[0018] Figure 3 This is a right-hand view of the cross-sectional internal structure of the mixing tank and inner cylinder of the present invention.

[0019] Figure 4 This is a schematic diagram of the exploded structure of the feed hopper and inner cylinder of the present invention;

[0020] Figure 5 This is a schematic diagram of the filter plate of the present invention blocking the feed hopper;

[0021] Figure 6 This is a left view of a partial cross-sectional structure of the mixing tank and inner cylinder of the present invention;

[0022] Figure 7 This is a top view of the inner cylinder, floating plate, and diversion plate structure of the present invention;

[0023] Figure 8 This is a schematic diagram of the connection structure between the lever and the flow limiting plate of the present invention;

[0024] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point A in the diagram;

[0025] Figure 10 This is a schematic diagram illustrating the principle of how the lever drives the floating plate to rotate in this invention.

[0026] Figure 11 This is a schematic diagram of the tilting structure of the floating plate of the present invention.

[0027] The meanings of the labels in the diagram are as follows:

[0028] 100, mixing tank; 101, feeding hopper; 102, stirring device; 103, liquid inlet pipe; 104, liquid outlet pipe; 105, hydraulic rod;

[0029] 110, inner cylinder; 111, inner mixing bin; 112, outer mixing bin; 113, outer flow port; 114, circulating pump;

[0030] 120, flow limiting mechanism; 121, flow limiting plate; 122, shifting rod; 123, cross plate; 124, motor;

[0031] 130, floating plate; 131, flow guiding plate; 132, guide rail; 133, first stop block; 134, second stop block;

[0032] 140, filter screen plate. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0034] Due to the vortex formed in the solution during stirring of the stirring plate, the vortex causes the urea particles to gather towards the outer circle, resulting in differences in urea concentration in different regions of the solution. The urea concentration is lower in the central region, while the urea concentration is too high in the outer circle region, and a uniform mixed solution cannot be formed. Moreover, in the prior art, when urea particles are added, a hole is usually cut on a urea packaging bag, and urea particles are dropped into the solution while stirring, which causes a large amount of urea particles to fall into the same region and cannot be uniformly covered on the solution, thereby reducing the mixing efficiency.

[0035] In view of the above problems, the present application provides a urea production device, as shown in Figures 1-3 The urea production device comprises a mixing tank 100, a feeding hopper 101, a stirring device 102, a liquid inlet pipe 103 and a liquid outlet pipe 104. An inner cylinder 110 is arranged in the mixing tank 100. The mixing tank 100 is divided into an inner mixing bin 111 for storing a pre-mixed solution and an outer mixing bin 112 for storing raw materials to be mixed from the inside to the outside by the inner cylinder 110. Before urea production, raw solution is first delivered into the inner cylinder 110 through the liquid inlet pipe 103, and the liquid outlet pipe 104 is in a closed state at this time. Then, as the raw solution is injected into the inner cylinder 110, the liquid level rises, and when the raw solution in the inner cylinder 110 reaches a set liquid level, the injection is stopped, and urea particles are then added to the raw solution for mixing.

[0036] It should be understood that when the small particles are mixed with the original solution in the inner cylinder 110, the formed solution is the premix, and the large particles falling into the outer mixing bin 112 are the raw materials to be mixed.

[0037] Wherein, the urea particles are added into the mixing tank 100 through the feeding hopper 101, and the filter screen plate 140 is arranged above the inner cylinder 110, between the inner cylinder 110 and the feeding hopper 101. The filter screen plate 140 uniformly disperses the small particle raw materials in the inner mixing bin 111, and guides the large particle raw materials into the outer mixing bin 112. In this way, for some urea particles that can pass through the filter screen plate 140, they are dispersed from the top of the filter screen plate 140 along the slope to the end, and the small particles passing through the filter screen plate 140 can be uniformly dispersed onto the original solution inside the inner cylinder 110 for mixing.

[0038] Secondly, the caked urea particles or single large particles cannot pass through the filter screen plate 140, and are guided into the outer mixing bin 112 for storage through the filter screen plate 140. Since the end of the filter screen plate 140 is a certain height away from the bottom wall of the outer mixing bin 112, the caked urea particles rolling off the filter screen plate 140 have kinetic energy and potential energy, and form an impact when contacting the bottom wall of the outer mixing bin 112, which is beneficial to break up the caked urea particles, thereby improving the mixing effect with the premix later.

[0039] Combining Figure 4 and Figure 5 As shown, when the raw materials are added into the feeding hopper 101, the top of the feeding hopper 101 is wide-mouthed, which is convenient for adding raw materials. The top of the filter screen plate 140 is fixedly provided with a hydraulic rod 105, which is responsible for controlling the height of the filter screen plate 140. In the stop material stage, the hydraulic rod 105 drives the filter screen plate 140 to move upwards, and the filter screen plate 140 is attached to the bottom of the feeding hopper 101 to limit the discharge of raw materials. In the material injection stage, the hydraulic rod 105 pushes the filter screen plate 140 downwards, and the filter screen plate 140 is away from the bottom of the feeding hopper 101. There is a discharging channel between the bottom of the feeding hopper 101 and the filter screen plate 140 for the flow of raw materials. In this way, the raw materials stored in the feeding hopper 101 roll down to the filter screen plate 140 through the discharging channel, and are screened through the filter screen plate 140, so that the large and small particle urea falls into the corresponding area, thereby realizing the purpose of quantitative feeding, avoiding the phenomenon of mixing too much urea particles at one time, and causing the local solution concentration to be too high.

[0040] Returning to Figure 2 and Figure 3As shown, the inner mixing bin 111 is provided with a flow limiting mechanism 120 at the bottom, and a flow disturbing mechanism is symmetrically arranged on the inner side. In the liquid separation stage, the flow limiting mechanism 120 is responsible for releasing the raw liquid in the inner mixing bin 111, and the impact of the raw liquid pressure in the inner mixing bin 111 on the to-be-mixed raw material in the outer mixing bin 112 is used to realize solid-liquid mixing, and the flow disturbing mechanism moves the solution at the inner wall of the inner cylinder 110 to the axis by floating up and down; in the liquid combination stage, the flow limiting mechanism 120 separates the inner mixing bin 111 from the outer mixing bin 112, and the flow disturbing mechanism forces the solution at the inner wall of the inner cylinder 110 to jump and hit the rear solution in an inclined manner. The specific principle is as follows:

[0041] Firstly, when the pre-mixed liquid in the inner cylinder 110 is mixed, the next liquid separation stage is carried out, that is, a part of the pre-mixed liquid in the inner cylinder 110 is separated and flows into the outer mixing bin 112, so that the separated pre-mixed liquid is mixed with the to-be-mixed raw material. When mixing, the outer flow port 113 is symmetrically opened below the inner wall of the inner cylinder 110 to communicate the inner mixing bin 111 with the outer mixing bin 112, the outer flow port 113 guides the pre-mixed liquid into the outer mixing bin 112, and finally the liquid levels in the inner mixing bin 111 and the outer mixing bin 112 maintain the same height; in this process, since the liquid level height of the pre-mixed liquid in the initial state is D1, the liquid level in this state has a corresponding gravitational potential energy. When the liquid separation is carried out, the gravitational potential energy of the pre-mixed liquid is converted into kinetic energy to impact the to-be-mixed raw material, so that the pre-mixed liquid is dispersed twice to the to-be-mixed raw material, and the mixing effect of the pre-mixed liquid and the to-be-mixed raw material is improved.

[0042] Further, the principle that the pre-mixed liquid in the inner mixing bin 111 flows into the outer mixing bin 112 is as follows: the specific structure of the flow limiting mechanism 120 is described below. The flow limiting mechanism 120 includes a flow limiting plate 121 which is arranged on the inner wall of the inner cylinder 110 and corresponds to the outer flow port 113. In the normal state, the flow limiting plate 121 is in coincidence with the outer flow port 113, and the flow limiting plate 121 is used to block the outer flow port 113 to limit the flow of the pre-mixed liquid. In the liquid separation stage, the flow limiting plate 121 is in a misaligned state with the outer flow port 113.

[0043] On the other hand, the two side flow limiting plates 121 are fixedly connected with a horizontal plate 123, the output shaft of a motor 124 is fixedly connected to the middle part of the horizontal plate 123, and the motor 124 is located at the bottom of the mixing tank 100. In this way, the raw liquid and small particle urea are mixed by the stirring device 102 to form a pre-mixed liquid after a period of time, the motor 124 is started to drive the horizontal plate 123 to rotate, the flow limiting plate 121 is misaligned with the outer flow port 113, the outer flow port 113 is turned on, the pre-mixed liquid flows into the outer mixing bin 112 to mix with the to-be-mixed raw material, and the liquid levels in the inner mixing bin 111 and the outer mixing bin 112 maintain a stable state (referring to the middle liquid level depth D2). Figure 6

[0044] ​When the pre-mixed liquid in the inner mixing bin 111 is reduced, the stirring paddle can play a more full role in the pre-mixed liquid. The shear force, circulating flow and the like generated by the rotation of the stirring paddle can cover all parts of the pre-mixed liquid, so that the particles, molecules and the like in the pre-mixed liquid can collide and mix with each other more frequently, and the probability of occurrence of stirring dead angles is reduced.

[0045] That is, when feeding, the filter screen plate 140 controls the amount of discharging by moving up and down to realize precise discharging and avoid one-time large feeding. At the same time, the raw materials are sorted by passing through the filter screen plate 140, the small particle raw materials slide along the filter screen plate 140 and are evenly scattered in the solution, and the large particle raw materials are guided into the outer mixing bin 112 for storage, thereby preventing the problem of uneven mixing caused by agglomeration of the caked raw materials.

[0046] In addition, during the process of the pre-mixed liquid level falling, the flow disturbing mechanism also moves downward synchronously, so that, in combination with the fact that the stirring mechanism 102 is also rotating, the pre-mixed liquid in the inner cylinder 110 is stirred and disturbed in a vortex manner. Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 As shown in the drawings, the flow disturbing mechanism is disclosed below and includes a floating plate 130 floating on the surface of the pre-mixed liquid and a flow guide plate 131 rotationally connected to the bottom of the floating plate 130. During the process of the pre-mixed liquid level falling and the stirring of the stirring device 102, a vortex is formed in the inner cylinder 110. Since the solution outside the vortex is unstable, it is easy to form waves. Therefore, the floating plate 130 uses the waves formed by the surface of the pre-mixed liquid as power to drive the flow guide plate 131 to move up and down in the pre-mixed liquid to disturb the pre-mixed liquid at different depths.

[0047] Next, the flow guide plate 131 is slidingly connected on one side to a guide rail 132 fixed to the inner wall of the inner cylinder 110 and extends to the axis on the other side and is outwardly inclined at the end to form an outwardly inclined end. During the counterclockwise rotation of the pre-mixed liquid, the rotating pre-mixed liquid collides with the flow guide plate 131, breaking the original state of the rotating pre-mixed liquid, realizing the interception and disturbance of the pre-mixed liquid, and at the same time, the outwardly inclined end is used to guide the solution at the wall of the inner cylinder 110 inward, so that the solution at the outer circle of the vortex is mixed with the solution in the middle of the vortex, improving the mixing effect. In combination with Figure 10 、 Figure 11 As shown in the drawings, the flow disturbing mechanism is disclosed below and includes a floating plate 130 floating on the surface of the pre-mixed liquid and a flow guide plate 131 rotationally connected to the bottom of the floating plate 130. During the process of the pre-mixed liquid level falling and the stirring of the stirring device 102, a vortex is formed in the inner cylinder 110. Since the solution outside the vortex is unstable, it is easy to form waves. Therefore, the floating plate 130 uses the waves formed by the surface of the pre-mixed liquid as power to drive the flow guide plate 131 to move up and down in the pre-mixed liquid to disturb the pre-mixed liquid at different depths. Figure 6As shown in the figure, the liquid suction pipe of the circulating pump 114 extends into the bottom of the outer mixing tank 112, and the liquid delivery pipe is connected with the inner mixing tank 111. Then, the flow limiting plate 121 is rotated to the state of coinciding with the outer flow port 113. In this way, when the mixed liquid in the outer mixing tank 112 is pumped into the inner mixing tank 111, the backflow of the solution in the inner mixing tank 111 to the outer mixing tank 112 is avoided.

[0048] Therefore, the circulating pump 114 is responsible for pumping the mixed liquid in the outer mixing tank 112 into the inner mixing tank 111. The liquid level in the inner mixing tank 111 is gradually raised, the drainage plate 131 moves upward along the guide rail 132, the mixed liquid pumped into the inner mixing tank 111 is mixed with the pre-mixed liquid in the inner mixing tank 111, and the stirring effect of the stirring device 102 enables the two kinds of mixed liquids to be fully and uniformly mixed.

[0049] Moreover, since the circulating pump 114 injects from the top of the liquid surface of D2, the liquid level of the mixed liquid in the inner mixing tank 111 gradually rises, and then the solution in the outer mixing tank 112 is mixed into the inner mixing tank 111 under the stirring action of the stirring device 102. In this way, the two solutions can be more uniformly mixed, and the mixing effect is improved.

[0050] Secondly, when the outer flow port 113 is blocked, the lever 122 drives the floating plate 130 to rotate clockwise, so that the right end of the floating plate 130 is immersed in the solution, and the left end is raised upward. In order to avoid the reverse rotation of the floating plate 130 driven by the lever 122, first and second stoppers 133 and 134 are respectively arranged on both sides of the rotating connection between the floating plate 130 and the drainage plate 131. The first and second stoppers 133 and 134 are fixed with the floating plate 130, and the first stopper 133 is close to the rotating connection, and the second stopper 134 is away from the rotating connection.

[0051] When the lever 122 drives the floating plate 130 to rotate clockwise, the length of the second stopper 134 is greater than that of the first stopper 133. When the lever 122 is close to the floating plate 130, the lever 122 drives the floating plate 130. At this time, the second stopper 134 is used to abut against the water-facing surface of the drainage plate 131 to limit the excessive rotation of the floating plate 130, and the first stopper 133 is used to abut against the water-back surface of the drainage plate 131 to limit the reverse rotation of the floating plate 130, preventing the liquid surface from driving the floating plate 130 to rotate counterclockwise. With the increase of the rotation amplitude of the lever 122, when the flow limiting plate 121 blocks the outer flow port 113, the second stopper 134 is in contact with the water-facing surface of the drainage plate 131, the water-facing side of the floating plate 130 (the right side in the figure) sinks, and the water-back side rises. With the rotating action of the pre-mixed liquid, the pre-mixed liquid slides from the sinking end and separates from the rising end, so as to use the jumping water flow to impact the solution behind, improve the mixing effect of the solution, and make the concentration of the solution uniform. Figure 11

[0052] ​In summary, in the liquid separation stage, the water waves generated by the vortex rotation drive the floating plate 130 to move up and down in the pre-mixed liquid, and the floating plate 130 drives the guide plate 131 to move up and down in the pre-mixed liquid, so that the vortex outer ring solution at different depths is guided to the axis, thereby enhancing the mixing degree of the solution in the horizontal direction. In the liquid mixing stage, the floating plate 130 tilts to jump the vortex outer ring solution to a high position, so as to impact the rear of the guide plate 131 by using the gravitational potential energy, further break the local concentration difference, and promote the solution to reach a more uniform mixing state.

[0053] Finally, after the solution in the inner cylinder 110 is mixed, the solution is discharged from the liquid discharge pipe 104.

[0054] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A urea production apparatus, comprising a mixing tank (100), a feeding hopper (101), a stirring device (102), a liquid inlet pipe (103), and a liquid outlet pipe (104), characterized in that: An inner cylinder (110) is provided inside the mixing tank (100). The inner cylinder (110) divides the mixing tank (100) from the inside to the outside into an inner mixing chamber (111) for storing premixed liquid and an outer mixing chamber (112) for storing raw materials to be mixed. A filter plate (140) is provided above the inner cylinder (110). The filter plate (140) evenly disperses small particles of raw materials in the inner mixing chamber (111) and guides large particles of raw materials to the outer mixing chamber (112). The bottom of the inner mixing chamber (111) is provided with a flow limiting mechanism (120), and a flow turbulence mechanism is symmetrically arranged on the inner side. During the liquid separation stage, the flow limiting mechanism (120) is responsible for releasing the original liquid in the inner mixing chamber (111). The pressure of the original liquid in the inner mixing chamber (111) is used to impact the raw materials to be mixed in the outer mixing chamber (112) to achieve solid-liquid mixing. The flow turbulence mechanism moves the solution attached to the wall of the inner cylinder (110) towards the axis by floating up and down. During the liquid mixing stage, the flow limiting mechanism (120) separates the inner mixing chamber (111) from the outer mixing chamber (112). The flow turbulence mechanism forces the solution attached to the wall of the inner cylinder (110) to jump up and smash the solution behind it in an inclined manner. A circulation pump (114) is installed in the outer mixing chamber (112). The pumping pipe of the circulation pump (114) extends into the bottom of the outer mixing chamber (112), and the delivery pipe is connected to the inner mixing chamber (111). The mixture pumped into the inner mixing chamber (111) is mixed with the premixed liquid in the inner mixing chamber (111), and with the stirring action of the stirring device (102), the two mixtures can be fully and evenly mixed. After the solution in the inner cylinder (110) has been mixed, the solution is discharged from the drain pipe (104).

2. The urea production apparatus according to claim 1, characterized in that: A hydraulic rod (105) is fixedly installed on the top of the filter screen plate (140). The hydraulic rod (105) is responsible for controlling the height of the filter screen plate (140). During the material stop stage, the filter screen plate (140) is attached to the bottom of the feed hopper (101) to restrict the discharge of raw materials. During the material injection stage, the filter screen plate (140) is away from the bottom of the feed hopper (101). There is a material discharge channel between the bottom of the feed hopper (101) and the filter screen plate (140) for the flow of raw materials.

3. The urea production apparatus according to claim 1, characterized in that: An outflow port (113) is symmetrically provided below the inner wall of the inner cylinder (110) to connect the inner mixing chamber (111) and the outer mixing chamber (112). The outflow port (113) guides the premixed liquid into the outer mixing chamber (112).

4. The urea production apparatus according to claim 3, characterized in that: The flow limiting mechanism (120) includes a flow limiting plate (121) that is fitted to the inner wall of the inner cylinder (110) and corresponds to the outflow port (113). Under normal conditions, the flow limiting plate (121) and the outflow port (113) are in an overlapping state. The flow limiting plate (121) is used to block the outflow port (113) and restrict the flow of the premixed liquid. During the liquid separation stage, the flow limiting plate (121) and the outflow port (113) are in a misaligned state.

5. The urea production apparatus according to claim 4, characterized in that: A horizontal plate (123) is fixedly connected between the two flow restricting plates (121). The output shaft of the motor (124) is fixedly connected in the middle of the horizontal plate (123). The motor (124) is located at the bottom of the mixing tank (100).

6. The urea production apparatus according to claim 4, characterized in that: The turbulence mechanism includes a floating plate (130) floating on the surface of the premixed liquid and a diversion plate (131) rotatably connected to the bottom of the floating plate (130). The floating plate (130) uses the waves formed on the surface of the premixed liquid as power to drive the diversion plate (131) to move up and down in the premixed liquid to turbulent the premixed liquid at different depths.

7. The urea production apparatus according to claim 6, characterized in that: The guide plate (131) is slidably connected to a guide rail (132) fixed to the inner wall of the inner cylinder (110) on one side, and extends towards the axis on the other side, with the end inclined outward to form an outward end. The outward end is used to guide the solution at the wall of the inner cylinder (110) to the inward side, so that the solution at the outer ring of the vortex is mixed with the solution in the middle of the vortex.

8. The urea production apparatus according to claim 6, characterized in that: The flow limiting mechanism (120) also includes a lever (122) fixedly installed inside the flow limiting plate (121). The floating plate (130) is located on the rotation path of the lever (122). The lever (122) is used to rotate the floating plate (130) and block the floating plate (130), so that one end of the floating plate (130) is raised from the surface of the premixed liquid and the other end is submerged in the premixed liquid.

9. The urea production apparatus according to claim 6, characterized in that: A first stop (133) and a second stop (134) are respectively provided on both sides of the rotatable connection between the floating plate (130) and the diversion plate (131). The first stop (133) and the second stop (134) are both fixed to the floating plate (130), and the first stop (133) is close to the rotatable connection, while the second stop (134) is far away from the rotatable connection.

10. The urea production apparatus according to claim 9, characterized in that: The second stop (134) is longer than the first stop (133). The second stop (134) is used to abut against the water-facing surface of the diversion plate (131) to limit the excessive rotation of the floating plate (130). The first stop (133) is used to abut against the water-reverse surface of the diversion plate (131) to limit the reverse rotation of the floating plate (130).

Images