Liquid fertilizer production system and mixing method

Abstract

The present invention relates to the technical field of liquid mixing, and specifically to a liquid fertilizer production system and a mixing method, comprising at least two stirring tanks for material mixing, the stirring tank comprising a tank body and a stirring mechanism, the side wall of the tank body being provided with an interlayer; and also comprising an internal steam heating mechanism; the internal steam heating mechanism comprising: a steam introduction disk fixed on a stirring shaft of the stirring mechanism, the interior of the steam introduction disk having a cavity; a steam introduction pipe for introducing steam into the steam introduction disk, one end of the steam introduction pipe being connected to the steam introduction disk, and the other end being connected to a steam supply device; a steam dispersion pipe, the top of which is connected to the steam introduction disk, the steam introduction disk being connected to a plurality of steam dispersion pipes, and the side wall of the steam dispersion pipe being provided with a plurality of exhaust holes. The present invention can prevent the interlayer of the stirring tank from being introduced with excessively high temperature steam, resulting in the decomposition of urea to form corrosive methylammonium, and can make the overall temperature in the stirring tank greater than 70°C, and will not cause urea crystallization.

Description

Technical Field

[0001] The invention relates to the technical field of liquid mixing, and in particular to a liquid fertilizer production system and a mixing method. Background Art

[0002] Liquid fertilizer refers to fertilizer that has no fixed shape and is in a flowing state; it includes clear liquid type and suspended type. Adding nitrogen fertilizer, potassium chloride and trace elements to the clear liquid can produce multi-component liquid compound fertilizer. Among them, the source of nitrogen in nitrogen fertilizer is mainly urea. For example, the production process of one multi-component liquid compound fertilizer containing urea is: prepare urea-ammonium nitrate solution and ammonium polyphosphate solution separately; then mix the urea-ammonium nitrate solution and ammonium polyphosphate solution and add potassium chloride and trace elements to make the product.

[0003] In the process of producing liquid fertilizer, the raw materials need to be dissolved and mixed. The dissolution and mixing are achieved in a mixing tank. For the mixing of urea-containing solutions, in addition to designing a stirring mechanism for uniform mixing, the crystallization and corrosion of urea also need to be considered. Urea will crystallize at temperatures below 70°C, which can cause pipeline blockage; and at temperatures above 120°C, urea will produce a byproduct of ammonium carbamate (methylammonium) due to high-temperature decomposition. Methylammonium will corrode metal equipment and pipelines. Long-term corrosion will cause the walls of metal equipment and pipelines to become thinner, and serious perforation problems may occur.

[0004] Therefore, in the process of producing liquid fertilizer, it is necessary to control the temperature of the liquid in the stirring tank. The prior art is to set up an interlayer and pass high-temperature steam into the interlayer to achieve temperature control of the stirring tank. However, in industrial production, the production volume of liquid fertilizer is large and the volume of the stirring tank used is large. If the temperature is controlled only by the interlayer, in order to avoid urea crystallization, it is necessary to pass higher temperature steam to ensure that the temperature of the liquid in the center of the stirring tank is not lower than 70°C. However, the higher temperature steam will cause the temperature of the liquid near the inner wall of the stirring tank to be too high, causing the urea to decompose and form corrosive methylammonium. Summary of the invention

[0005] The object of the present invention is to provide a liquid fertilizer production system and a mixing method, which can avoid the decomposition of urea to form corrosive methylammonium due to the introduction of excessively high temperature steam into the interlayer of the stirring tank, and can make the overall temperature in the stirring tank greater than 70°C without the occurrence of urea crystallization.

[0006] The present invention is achieved through the following technical solutions:

[0007] A liquid fertilizer production system includes at least two stirring tanks for mixing materials, wherein the stirring tanks include a tank body and a stirring mechanism arranged in the tank body, and the side wall of the tank body is provided with an interlayer for heating the materials in the tank body; and further includes an internal steam heating mechanism; the internal steam heating mechanism includes:

[0008] The steam introduction plate is fixed on the stirring shaft of the stirring mechanism, and the interior of the steam introduction plate has a cavity;

[0009] A steam introduction pipe is used to introduce steam into the steam introduction plate, one end of the steam introduction pipe is connected to the steam introduction plate, and the other end is connected to the steam supply equipment;

[0010] The top of the steam dispersion pipe is connected to the steam introduction plate, the steam introduction plate is connected to multiple steam dispersion pipes, and the side wall of the steam dispersion pipe is provided with a plurality of exhaust holes, which are used to introduce steam into the tank body.

[0011] The internal steam heating mechanism of the present invention is arranged in the tank body. When materials for preparing liquid fertilizer are mixed in the tank body, steam can be introduced into the tank body through the internal steam heating mechanism, and the materials are heated by dispersing the steam in the liquid, that is, the internal steam heating mechanism and the interlayer heat the liquid materials in the tank body at the same time, and heat transfer can be carried out from the radial inside and outside of the tank body at the same time, which can ensure that the liquid materials in the tank body can be heated. By introducing 70-120°C steam into the interlayer and the internal steam heating mechanism, the temperature of the liquid materials in the tank body can be always greater than 70°C during mixing, and the problem of urea crystallization will not occur. Compared with heating through the interlayer alone, it can avoid using too high a temperature to heat the liquid materials in the tank body.

[0012] Furthermore, the steam introduction plate of the present invention is arranged in the tank body by being fixed on the stirring shaft of the stirring mechanism, so that the steam dispersion pipe rotates with the stirring shaft, which is beneficial for the steam derived from the steam dispersion pipe to be evenly mixed in the liquid material, thereby improving the uniformity of heating the liquid material in the tank body.

[0013] In summary, the present invention can avoid the decomposition of urea to form corrosive methylammonium due to excessively high temperature entering the interlayer of the stirring tank by arranging an internal steam heating mechanism in the tank body, and can keep the overall temperature in the stirring tank greater than 70°C without the occurrence of urea crystallization.

[0014] In a preferred embodiment, the steam dispersion pipe includes an outer pipe, a connector, an inner pipe and a gas-liquid separation mechanism;

[0015] The outer tube is coaxially arranged with the inner tube, and a plurality of rows of air-permeable units are arranged on the side wall of the outer tube, and each row of air-permeable units is provided with a plurality of first air outlet holes along the axial direction of the outer tube;

[0016] The inner wall of the connector is connected to the outer wall of the inner tube, and the outer wall of the connector is detachably connected to the inner wall of the outer tube through a gas-liquid separation mechanism. The side wall of the connector is provided with a plurality of gas outlet channels, and each column of first gas outlet holes corresponds to an gas outlet channel, and the top of the gas outlet channel is a closed end;

[0017] The top of the inner tube protrudes from the outer tube, the inner tube is connected to the steam inlet disk, and a second air outlet hole is provided on the side wall of the inner tube. The steam in the steam inlet disk enters the tank body through the second air outlet hole, the air outlet channel, the gas-liquid separation mechanism and the first air outlet hole in sequence.

[0018] The steam dispersion pipe of the present invention adopts a special structural design, which can be connected to the steam introduction disk to introduce the steam in the steam introduction disk into the steam dispersion pipe, and a gas-liquid separation mechanism can be embedded in the steam dispersion pipe. The gas-liquid separation mechanism contains a gas-liquid separation membrane. The gas-liquid separation membrane is a prior art, also known as a hydrophobic filter membrane. The gas-liquid separation membrane can pass steam but cannot pass liquid. That is, by setting the gas-liquid separation mechanism, it is possible to introduce steam into the tank body and prevent the liquid in the tank body from entering the steam dispersion pipe and causing urea crystallization on the inner wall of the steam dispersion pipe. If the liquid in the tank body enters the steam dispersion pipe, when the tank body stops steam heating, the liquid in the steam dispersion pipe will cause the problem of urea crystallization.

[0019] The gas-liquid separation mechanism of the present invention is detachably arranged, so that the gas-liquid separation mechanism can be replaced. In addition, the gas-liquid separation mechanism is easy to process and install. The connector and the inner tube are processed into an integral shape. During installation, the gas-liquid separation mechanism is first fixed to the outer wall of the connector, and then the gas-liquid separation mechanism is connected to the outer tube, and finally the inner tube is connected to the steam inlet disk.

[0020] In a preferred embodiment, the gas-liquid separation mechanism includes an arc-shaped positioning plate, an outer sealing strip, an inner sealing strip and a gas-liquid separation component;

[0021] A through groove is provided on the arc-shaped positioning plate, and a gas-liquid separation component is filled in the through groove;

[0022] At least two inner sealing strips are provided, and the plurality of inner sealing strips are provided on both sides of the gas-liquid separation component. A first groove is provided on the outer wall of the connector, and the inner sealing strip is embedded in the first groove.

[0023] At least two outer sealing strips are provided, and the plurality of outer sealing strips are provided on both sides of the gas-liquid separation component. A second groove is provided on the inner wall of the outer tube, and the outer sealing strip is embedded in the second groove.

[0024] The inner and outer sealing strips of the present invention can not only realize the detachable connection between the gas-liquid separation mechanism and the connector and the outer tube, but also realize the sealing of the annular gap between the connector and the outer tube, and seal steam from entering the annular gap between the connector and the outer tube.

[0025] In a preferred embodiment, the inner sealing strip and the outer sealing strip are staggered in the circumferential direction of the arc-shaped positioning plate. In this case, the side sealing strip and the outer sealing strip are equivalent to two sealing rings arranged on the same side of the through groove, which can improve the sealing effect, and the forces exerted by the inner sealing strip and the outer sealing strip on the connector and the outer tube are not in the same radial direction, which is conducive to improving the structural stability of the steam dispersion tube.

[0026] In a preferred embodiment, the gas-liquid separation component includes a frame and a gas-liquid separation membrane;

[0027] The gas-liquid separation membrane is fixed in the frame;

[0028] The inner opening end of the through groove forms an annular step, and the gas-liquid separation component is pressed against the inner wall of the arc-shaped positioning plate through the pressure strip.

[0029] The above arrangement can realize a detachable arrangement of the gas-liquid separation membrane, making it easy to replace the gas-liquid separation membrane.

[0030] In a preferred embodiment, the gas-liquid separation component also includes a plurality of reinforcing ribs; the plurality of reinforcing ribs are arranged axially along the arc-shaped positioning plate, the gas-liquid separation membrane is arranged between two adjacent reinforcing ribs, and the reinforcing ribs and the first gas outlet hole are staggered in the axial direction of the outer tube.

[0031] Since the axial length of the steam dispersion pipe is relatively long and the gas-liquid separation membrane is made of flexible material, the provision of the reinforcing ribs can reduce the problem of deformation of the gas-liquid separation membrane caused by steam or liquid material scouring.

[0032] In a preferred embodiment, the air outlet channel includes an equal-diameter channel and a variable-diameter channel that are interconnected, the variable-diameter channel is connected to the second air outlet hole at one end away from the equal-diameter channel, and the circumferential width of the variable-diameter channel tends to gradually decrease from the end connected to the second air outlet hole to the end connected to the equal-diameter channel; the minimum circumferential width of the variable-diameter channel is equal to the circumferential width of the equal-diameter channel.

[0033] The above-mentioned shape of the air outlet channel can increase the pressure of steam entering the first air outlet hole, increase the speed of steam entering the tank body, and make the steam quickly and evenly dispersed in the liquid material in the tank body.

[0034] In a preferred embodiment, the distance between the steam dispersion pipe and the inner wall of the tank body is less than or equal to the distance between the steam dispersion pipe and the stirring shaft of the stirring mechanism.

[0035] Since the present invention adopts the interlayer and the internal steam heating mechanism to heat the liquid material in the tank body at the same time, and the interlayer transfers heat outward and inward, the internal steam heating mechanism can transfer heat on both sides, which is mainly used to heat the liquid material located at the axial center of the tank body. Therefore, the steam dispersion pipe is arranged close to the stirring shaft of the stirring mechanism, which is more conducive to heat transfer between the interlayer and the internal steam heating mechanism and reduces heat waste.

[0036] In a preferred embodiment, the tank body is provided with an air inlet pipe and an air outlet pipe communicating with the interlayer;

[0037] The air inlet pipe is provided with a steam mixing chamber, and the steam mixing chamber is provided with a first steam introduction pipe, a second steam introduction pipe and a third steam introduction pipe; the first steam introduction pipe, the second steam introduction pipe and the third steam introduction pipe are used to introduce medium-temperature steam, high-temperature steam and low-temperature steam into the steam mixing chamber respectively;

[0038] A temperature sensor is provided in the steam mixing chamber;

[0039] The liquid fertilizer production system also includes a control unit, which includes a controller and a motor, an air intake main valve, a first air intake valve, a second air intake valve, a third air intake valve and an exhaust valve that are communicatively connected to the controller;

[0040] The main air intake valve is arranged on the steam inlet pipe, the motor is used to drive the stirring mechanism to rotate, the first air intake valve, the second air intake valve and the third air intake valve are arranged on the first steam inlet pipe, the second steam inlet pipe and the third steam inlet pipe respectively, and the exhaust valve is arranged on the exhaust pipe.

[0041] The medium-temperature steam of the present invention refers to steam with a temperature of 80-120°C, the low-temperature steam refers to steam with a temperature of 50-70°C, and the high-temperature steam refers to steam with a temperature of 130-150°C.

[0042] Since the steam delivery pipeline has a certain length, when the delivery environment temperature is too low, the steam will experience temperature loss during the delivery process, causing the temperature entering the interlayer to be lower than 70°C, resulting in urea crystallization. Therefore, higher temperature steam is usually delivered to reduce steam loss caused by delivery. Delivery of steam at too high a temperature may cause the temperature entering the interlayer to be too high, but urea decomposes into methylammonium, which corrodes the inner wall of the tank and accessories such as the stirring mechanism. Therefore, the steam mixing chamber provided in the present invention can adjust the temperature before the steam enters the interlayer, so that the steam temperature entering the interlayer is controlled at about 100°C, which can not only achieve heating of the liquid material in the tank, but also avoid the problem of urea crystallization caused by the liquid material near the inner wall of the tank due to excessive temperature.

[0043] The mixing method based on the above liquid fertilizer production system comprises the following steps:

[0044] S1, introducing steam into the interlayer through the steam mixing chamber to preheat the tank body;

[0045] S2, adding the material to be mixed into the tank, and then the controller controls the motor and the main air inlet valve to start, and the stirring mechanism rotates to mix the material. At the same time, steam is introduced into the liquid material in the tank through the internal steam heating mechanism to heat it;

[0046] During the mixing process, the temperature sensor collects the temperature of the steam in the steam mixing chamber in real time, and the controller controls the opening and closing of the second air intake valve or the third air intake valve according to the collected temperature to adjust the temperature of the steam in the steam mixing chamber.

[0047] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0048] 1. The present invention provides an internal steam heating mechanism in the tank body. The internal steam heating mechanism and the interlayer heat the liquid material in the tank body at the same time, and can simultaneously transfer heat from the radial inner side and the outer side of the tank body, so as to ensure that the liquid material in the tank body can be heated. By introducing 70-120°C steam into the interlayer and the internal steam heating mechanism, the temperature of the liquid material in the tank body can be always greater than 70°C during mixing, and there is no need to use steam higher than 130°C. It can be avoided that the interlayer of the stirring tank is introduced with excessively high temperature steam, which causes urea to decompose and form corrosive methylammonium, and the overall temperature in the stirring tank can be greater than 70°C, and urea crystallization will not occur.

[0049] 2. The present invention designs the structure of the steam dispersion pipe, which can be connected to the steam introduction disk to introduce the steam in the steam introduction disk into the steam dispersion pipe, and a gas-liquid separation mechanism can be embedded in the steam dispersion pipe to avoid the problem of urea crystallization in the steam dispersion pipe.

[0050] 3. The present invention provides a steam mixing chamber on the exhaust pipe, and the steam mixing chamber is provided with a first steam inlet pipe, a second steam inlet pipe and a third steam inlet pipe, and a control unit is provided in combination, so that the temperature of the steam entering the interlayer can be adjusted to avoid the steam temperature entering the interlayer being too high or too low. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0052] Figure 1 It is a structural schematic diagram of the stirring tank of the present invention;

[0053] Figure 2 is a radial cross-sectional view of the steam dispersion pipe of the present invention;

[0054] Figure 3 for Figure 2 A partial enlarged view of point A;

[0055] Figure 4 It is a structural schematic diagram of the gas-liquid separation mechanism of the present invention;

[0056] Figure 5 It is a schematic diagram of the structure of the gas-liquid separation component of the present invention;

[0057] Figure 6 It is a top view of the steam introduction plate of the present invention.

[0058] Marks and corresponding parts names in the attached drawings:

[0059] 1-tank body; 2-stirring mechanism; 3-steam dispersion pipe; 4-steam introduction plate; 5-steam introduction pipe; 6-motor; 7-steam mixing chamber; 8-gas-liquid separation mechanism; 11-interlayer; 12-inlet pipe; 13-exhaust pipe; 14-liquid discharge port; 31-outer pipe; 32-connector; 33-inner pipe; 41-annular baffle; 71-first steam introduction pipe; 72-second steam introduction pipe; 73-third steam introduction pipe; 81-arc positioning plate; 82-outer sealing strip; 83-inner sealing strip; 84-annular step; 85-gas-liquid separation component; 86-pressing strip; 311-first air outlet hole; 321-air outlet channel; 331-second air outlet hole; 851-frame; 852-gas-liquid separation membrane; 853-reinforcement rib. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. The schematic implementation mode of the present invention and its description are only used to explain the present invention and are not intended to limit the present invention. The embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0061] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those of ordinary skill in the art that these specific details do not have to be employed to practice the present invention. In other embodiments, in order to avoid confusing the present invention, known structures, materials or methods are not specifically described. The materials, instruments and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. The technical means used in the examples, unless otherwise specified, are conventional means well known to those skilled in the art.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0063] Embodiment 1:

[0064] like Figure 1-Figure 6 As shown, a liquid fertilizer production system includes at least two stirring tanks for material mixing, the stirring tank includes a tank body 1 and a stirring mechanism 2 arranged in the tank body 1, the stirring mechanism 2 includes a stirring shaft and stirring blades arranged on the stirring shaft, the side wall of the tank body 1 is provided with an interlayer 11 for heating the material in the tank body 1, the tank body 1 is provided with an air inlet pipe 12 and an exhaust pipe 13 connected with the interlayer 11, the top of the tank body 1 is provided with a feed port, the bottom of the tank body 1 is provided with a drain port 14, and the drain port 14 is used to guide the evenly mixed liquid material in the tank body 1 out of the tank body 1. Multiple stirring tanks are used for different processes of preparing liquid fertilizers. For example, in a specific case, there are three stirring tanks, one for dissolving urea and ammonium nitrate with water to prepare urea-ammonium nitrate solution, one for preparing ammonium polyphosphate solution, and another for mixing urea-ammonium nitrate solution and ammonium polyphosphate solution to prepare liquid fertilizer. During the mixing process, the stirring tank for preparing urea-ammonium nitrate solution and the stirring tank for preparing liquid fertilizer both have the problem of low-temperature urea crystallization and high-temperature urea decomposing into methylammonium due to the presence of urea in the liquid. In order to solve the problem of low-temperature urea crystallization and high-temperature urea decomposing into methylammonium, this embodiment improves the existing stirring tank, and the main improvement is that an internal steam heating mechanism is set in the tank body; the internal steam heating mechanism includes:

[0065] The steam introduction plate 4 is fixed on the stirring shaft of the stirring mechanism 2, and the interior of the steam introduction plate 4 has a cavity.

[0066] The steam introduction pipe 5 is used to introduce steam into the steam introduction disc 4. One end of the steam introduction pipe 5 is connected to the steam introduction disc 4, and the other end is connected to the steam supply device. The steam supply device is a prior art, and can be a steam generator. Since the steam introduction disc 4 of this embodiment rotates during the mixing process, in order to ensure that the steam introduction pipe 5 does not move relative to the steam introduction disc 4, as shown in FIG. Figure 6 As shown, an annular groove is provided on the top of the steam inlet disk 4, and the annular groove is coaxially arranged with the steam inlet disk 4, and also includes an annular baffle 41 for sealing the annular groove, and the annular baffle 41 is connected to the annular groove by a movable sealing ring, and the movable sealing ring is a prior art, which can not only realize the sealing at the connection between the annular baffle 41 and the annular groove, but also realize that the annular baffle 41 is immovable relative to the steam inlet disk 4, and one end of the steam inlet pipe 5 is connected to the annular baffle 41 and extends into the steam inlet disk 4, so that the steam inlet pipe 5 remains stationary when the steam inlet disk 4 rotates.

[0067] The top of the steam dispersion pipe 3 is connected to the steam introduction plate 4, and the steam introduction plate 4 is connected to multiple steam dispersion pipes 3. The side wall of the steam dispersion pipe 3 is provided with a plurality of exhaust holes, and the exhaust holes are used to introduce steam into the tank body 1, that is, the steam in the steam dispersion pipe 3 enters the tank body 1 through the exhaust holes. Preferably, multiple steam dispersion pipes 3 are evenly arranged around the steam introduction plate 4, and can be specifically as follows Figure 1 The number of the steam dispersion pipes as shown may be 4, or 6, 8, etc.; preferably, the top of the steam dispersion pipe 3 is connected to the bottom of the steam introduction plate 4.

[0068] The steam introduction plate 4 of this embodiment can rotate along with the rotation of the stirring mechanism 2, that is, in the process of stirring and mixing materials, the steam dispersion pipe 3 rotates together with the stirring shaft. The steam dispersion pipe 3 can not only play the role of introducing steam into the liquid material in the tank body 1 for heating, but also play the role of stirring and mixing, thereby improving the stirring effect of the stirring mechanism 2.

[0069] In a preferred case, the steam dispersion pipe 3 includes an outer pipe 31, a connector 32, an inner pipe 33 and a gas-liquid separation mechanism 8;

[0070] The outer tube 31 is coaxially arranged with the inner tube 33. The side wall of the outer tube 31 is provided with a plurality of rows of air permeable units. Each row of air permeable units is provided with a plurality of first air outlet holes 311 along the axial direction of the outer tube 31. Preferably, the plurality of first air outlet holes 311 are evenly spaced and arranged. The first air outlet holes 311 penetrate the side wall of the outer tube 31 and are used to connect the radial ends of the outer tube 31. In a specific case, Figure 2 As shown, the side wall of the outer tube 31 is provided with four rows of air permeable units.

[0071] The inner wall of the connecting body 32 is connected to the outer wall of the inner tube 33. Preferably, the connecting body 32 and the inner tube 33 are integrally formed. The outer wall of the connecting body 32 is detachably connected to the inner wall of the outer tube 31 through the gas-liquid separation mechanism 8. The side wall of the connecting body 32 is provided with a plurality of gas outlet channels 321. Each column of first gas outlet holes 311 is provided with a corresponding gas outlet channel 321. The top of the gas outlet channel 321 is a closed end. Specifically, the gas-liquid separation mechanism 8 includes an arc-shaped positioning plate 81, an outer sealing strip 82, an inner sealing strip 83 and a gas-liquid separation component 85;

[0072] The arc-shaped positioning plate 81 is provided with a through groove, and the through groove is filled with a gas-liquid separation component 85;

[0073] At least two inner sealing strips 83 are provided, and the plurality of inner sealing strips 83 are provided on both sides of the gas-liquid separation component 85. A first groove is provided on the outer wall of the connector 32, and the inner sealing strips 83 are embedded in the first groove.

[0074] At least two outer sealing strips 82 are provided, and the plurality of outer sealing strips 82 are provided on both sides of the gas-liquid separation component 85. A second groove is provided on the inner wall of the outer tube 31, and the outer sealing strip 82 is embedded in the second groove.

[0075] The inner sealing strip 83 is disposed on the inner wall of the arc-shaped positioning plate 81 , and the length direction of the inner sealing strip 83 is the axial direction of the arc-shaped positioning plate 81 , and the length of the inner sealing strip 83 is greater than the axial length of the air outlet channel 321 .

[0076] The outer sealing strip 82 is disposed on the outer wall of the arc-shaped positioning plate 81 , and the length direction of the outer sealing strip 82 is the axial direction of the arc-shaped positioning plate 81 , and the length of the outer sealing strip 82 is greater than the axial length of the air outlet channel 321 .

[0077] Specifically, the gas-liquid separation component 85 includes a frame 851 and a gas-liquid separation membrane 852;

[0078] The gas-liquid separation membrane 852 is fixed in the frame 851;

[0079] An annular step 84 is formed at the inner open end of the through groove, and the gas-liquid separation component 85 is pressed against the inner wall of the arc-shaped positioning plate 81 through a pressure strip 86 .

[0080] Preferably, the gas-liquid separation component 85 also includes a plurality of reinforcing ribs 853 ; the plurality of reinforcing ribs 853 are arranged axially along the arc-shaped positioning plate 81 , the gas-liquid separation membrane 852 is arranged between two adjacent reinforcing ribs 853 , and the reinforcing ribs 853 and the first gas outlet hole 311 are staggered in the axial direction of the outer tube 31 .

[0081] This embodiment provides an inner sealing strip 83 and an outer sealing strip 82, and correspondingly provides a first card groove and a second card groove, so that not only can the gas-liquid separation mechanism 8 be detachably arranged between the connecting body 32 and the outer tube 31, but also the annular gap between the connecting body 32 and the outer tube 31 can be sealed.

[0082] Preferably, the inner sealing strip 83 and the outer sealing strip 82 are staggered in the circumferential direction of the arc-shaped positioning plate 81; the inner sealing strip 83 and the outer sealing strip 82 are equivalent to providing two sealing rings on the same side of the through groove, which can improve the sealing effect, and the forces exerted by the inner sealing strip 83 and the outer sealing strip 82 on the connector 32 and the outer tube 31 are not in the same radial direction, which is beneficial to improving the structural stability of the steam dispersion tube 3.

[0083] Preferably, the air outlet channel 321 includes an equal-diameter channel and a variable-diameter channel that are interconnected, and the end of the variable-diameter channel away from the equal-diameter channel is connected to the second air outlet hole 331, and the circumferential width of the variable-diameter channel tends to gradually decrease from the end connected to the second air outlet hole 331 to the end connected to the equal-diameter channel; the minimum circumferential width of the variable-diameter channel is equal to the circumferential width of the equal-diameter channel.

[0084] The top of the inner tube 33 protrudes from the outer tube 31, and the inner tube 33 is connected to the steam inlet disk 4. Specifically, the connection between the two can be achieved by means of threaded connection or the like. A second air outlet hole 331 is provided on the side wall of the inner tube 33. The steam in the steam inlet disk 4 enters the tank body 1 through the second air outlet hole 331, the air outlet channel 321, the gas-liquid separation mechanism 8 and the first air outlet hole 311 in turn, that is, the second air outlet hole 331, the air outlet channel 321 and the first air outlet hole 311 constitute the exhaust hole of the steam dispersion pipe 3.

[0085] The first air outlet holes 311 of the present embodiment are arranged at even intervals rather than directly providing a through groove structure. On the one hand, this can reduce the scouring of the gas-liquid separation mechanism 8 by the liquid material in the tank body 1. On the other hand, it can increase the speed at which the steam enters the tank body 1 and improve the mixing effect of the steam in the liquid material in the tank body 1.

[0086] In a preferred case, the distance between the steam dispersion pipe 3 and the inner wall of the tank body 1 is less than or equal to the distance between the steam dispersion pipe 3 and the stirring shaft of the stirring mechanism 2 .

[0087] In a preferred case, the tank body 1 is provided with an air inlet pipe 12 and an air outlet pipe 13 communicating with the interlayer 11;

[0088] The air inlet pipe 12 is provided with a steam mixing chamber 7, and the steam mixing chamber 7 is provided with a first steam introduction pipe 71, a second steam introduction pipe 72 and a third steam introduction pipe 73; the first steam introduction pipe 71, the second steam introduction pipe 72 and the third steam introduction pipe 73 are used to introduce medium-temperature steam, high-temperature steam and low-temperature steam into the steam mixing chamber 7 respectively;

[0089] A temperature sensor is provided in the steam mixing chamber 7;

[0090] The liquid fertilizer production system further includes a control unit, which includes a controller and a motor 6, an air intake main valve, a first air intake valve, a second air intake valve, a third air intake valve and an exhaust valve, which are communicatively connected to the controller;

[0091] The main air intake valve is arranged on the steam inlet pipe 5, the motor 6 is used to drive the stirring mechanism 2 to rotate, the first air intake valve, the second air intake valve and the third air intake valve are respectively arranged on the first steam inlet pipe 71, the second steam inlet pipe 72 and the third steam inlet pipe 73, and the exhaust valve is arranged on the exhaust pipe 13.

[0092] The mixing method based on the above liquid fertilizer production system comprises the following steps:

[0093] S1, passing steam at about 100° C. into the interlayer 11 through the steam mixing chamber 7 to preheat the tank body 1;

[0094] S2, adding materials to be mixed into the tank body 1. For example, when the tank body 1 is used to prepare a urea-ammonium nitrate solution, urea, ammonium nitrate and water are put into the tank body 1 in proportion, and then the controller controls the motor 6 and the main air inlet valve to start, and the stirring mechanism 2 is rotated to achieve mixing of the materials. At the same time, steam at about 100° C. is introduced into the liquid material in the tank body 1 through the internal steam heating mechanism for heating. The steam introduced into the liquid material by the internal steam heating mechanism and the steam in the interlayer 11 heat the liquid material at the same time;

[0095] During the mixing process, the temperature sensor collects the temperature of the steam in the steam mixing chamber 7 in real time, and the controller controls the opening and closing of the second air intake valve or the third air intake valve according to the collected temperature to adjust the temperature of the steam in the steam mixing chamber 7.

[0096] The medium-temperature steam in this embodiment refers to steam with a temperature of 80-120°C, the low-temperature steam refers to steam with a temperature of 50-70°C, and the high-temperature steam refers to steam with a temperature of 130-150°C.

[0097] Specifically, when the temperature sensor detects that the steam temperature in the steam mixing chamber 7 is lower than 80°C, the controller controls the second air inlet valve to open, keeps the third air inlet valve closed, and introduces high-temperature steam into the steam mixing chamber 7 to maintain the temperature of the steam in the steam mixing chamber 7 at around 100°C. When the temperature sensor detects that the steam temperature in the steam mixing chamber 7 is higher than 110°C, the controller controls the third air inlet valve to open, keeps the second air inlet valve closed, and introduces low-temperature steam into the steam mixing chamber 7 to maintain the temperature of the steam in the steam mixing chamber 7 at around 100°C.

[0098] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0099] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like cited in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

Claims

1. A liquid fertilizer production system, comprising at least two stirring tanks for mixing materials, the stirring tanks comprising a tank body (1) and a stirring mechanism (2) arranged in the tank body (1), and a side wall of the tank body (1) is provided with an interlayer (11) for heating the material in the tank body (1); characterized in that: Also included is an internal steam heating mechanism; the internal steam heating mechanism comprises: A steam introduction plate (4) is fixed on the stirring shaft of the stirring mechanism (2), and the interior of the steam introduction plate (4) has a cavity; a steam introduction pipe (5) for introducing steam into the steam introduction disk (4), one end of which is connected to the steam introduction disk (4) and the other end of which is connected to a steam supply device; A steam dispersion pipe (3), the top of which is connected to a steam introduction plate (4), the steam introduction plate (4) being connected to a plurality of steam dispersion pipes (3), a plurality of exhaust holes being provided on the side wall of the steam dispersion pipe (3), the exhaust holes being used to introduce steam into the tank body (1); the steam dispersion pipe (3) comprising an outer pipe (31) and an inner pipe (33) which are coaxially arranged, a connector (32) and a gas-liquid separation mechanism (8); The side wall of the outer tube (31) is provided with a plurality of rows of air permeable units, and each row of air permeable units is provided with a plurality of first air outlet holes (311) along the axial direction of the outer tube (31); The connecting body (32) is arranged on the outer wall of the inner tube (33); the connecting body (32) and the outer tube (31) are connected via a gas-liquid separation mechanism (8); a plurality of gas outlet channels (321) are arranged on the side wall of the connecting body (32); and one gas outlet channel (321) is arranged corresponding to each column of first gas outlet holes (311); The top of the inner tube (33) protrudes from the outer tube (31); the inner tube (33) is connected to the steam introduction plate (4); a second gas outlet hole (331) is provided on the side wall of the inner tube (33); the steam in the steam introduction plate (4) sequentially passes through the second gas outlet hole (331), the gas outlet channel (321), the gas-liquid separation mechanism (8) and the first gas outlet hole (311) to enter the tank body (1); The gas-liquid separation mechanism (8) comprises a gas-liquid separation component (85), and the gas-liquid separation component (85) comprises a gas-liquid separation membrane (852).

2. A liquid fertilizer production system according to claim 1, characterized in that: The inner wall of the connecting body (32) is connected to the outer wall of the inner tube (33), and the outer wall of the connecting body (32) and the inner wall of the outer tube (31) are detachably connected via a gas-liquid separation mechanism (8); The top of the air outlet channel (321) is a closed end.

3. A liquid fertilizer production system according to claim 1, characterized in that: The gas-liquid separation mechanism (8) comprises an arc-shaped positioning plate (81), an outer sealing strip (82), an inner sealing strip (83) and a gas-liquid separation component (85); A through groove is provided on the arc-shaped positioning plate (81), and a gas-liquid separation component (85) is filled in the through groove; At least two inner sealing strips (83) are provided, and the plurality of inner sealing strips (83) are provided on both sides of the gas-liquid separation component (85); a first groove is provided on the outer wall of the connecting body (32), and the inner sealing strip (83) is embedded in the first groove; At least two outer sealing strips (82) are provided, and the plurality of outer sealing strips (82) are provided on both sides of the gas-liquid separation component (85). A second groove is provided on the inner wall of the outer tube (31), and the outer sealing strip (82) is embedded in the second groove.

4. A liquid fertilizer production system according to claim 3, characterized in that: The inner sealing strip (83) and the outer sealing strip (82) are staggered in the circumferential direction of the arc-shaped positioning plate (81).

5. A liquid fertilizer production system according to claim 3, characterized in that: The gas-liquid separation component (85) comprises a frame (851) and a gas-liquid separation membrane (852); The gas-liquid separation membrane (852) is fixed in the frame (851); An annular step (84) is formed at the inner open end of the through groove, and the gas-liquid separation component (85) is pressed against the inner wall of the arc-shaped positioning plate (81) via a pressure strip (86).

6. A liquid fertilizer production system according to claim 5, characterized in that: The gas-liquid separation component (85) further comprises a plurality of reinforcing ribs (853); the plurality of reinforcing ribs (853) are arranged along the axial direction of the arc-shaped positioning plate (81); the gas-liquid separation membrane (852) is arranged between two adjacent reinforcing ribs (853); and the reinforcing ribs (853) and the first gas outlet through holes (311) are arranged staggered in the axial direction of the outer tube (31).

7. A liquid fertilizer production system according to claim 1, characterized in that: The air outlet channel (321) comprises a constant diameter channel and a variable diameter channel which are connected to each other; an end of the variable diameter channel away from the constant diameter channel is connected to the second air outlet through hole (331); the circumferential width of the variable diameter channel gradually decreases from the end connected to the second air outlet through hole (331) to the end connected to the constant diameter channel; and the minimum circumferential width of the variable diameter channel is equal to the circumferential width of the constant diameter channel.

8. A liquid fertilizer production system according to claim 1, characterized in that: The distance between the steam dispersion pipe (3) and the inner wall of the tank body (1) is less than or equal to the distance between the steam dispersion pipe (3) and the stirring shaft of the stirring mechanism (2).

9. A liquid fertilizer production system according to any one of claims 1 to 8, characterized in that: An air inlet pipe (12) and an air outlet pipe (13) which are in communication with the interlayer (11) are provided on the tank body (1); A steam mixing chamber (7) is provided on the air inlet pipe (12), and a first steam introduction pipe (71), a second steam introduction pipe (72) and a third steam introduction pipe (73) are provided on the steam mixing chamber (7); the first steam introduction pipe (71), the second steam introduction pipe (72) and the third steam introduction pipe (73) are used to introduce medium-temperature steam, high-temperature steam and low-temperature steam into the steam mixing chamber (7), respectively; A temperature sensor is provided in the steam mixing chamber (7); The liquid fertilizer production system also includes a control unit, which includes a controller and a motor (6) communicatively connected to the controller, an air intake main valve, a first air intake valve, a second air intake valve, a third air intake valve, and an exhaust valve; The main air intake valve is arranged on the steam introduction pipe (5), the motor (6) is used to drive the stirring mechanism (2) to rotate, the first air intake valve, the second air intake valve and the third air intake valve are arranged on the first steam introduction pipe (71), the second steam introduction pipe (72) and the third steam introduction pipe (73) respectively, and the exhaust valve is arranged on the exhaust pipe (13).

10. A mixing method for a liquid fertilizer production system according to claim 9, characterized in that: The steps include: S1, introducing steam into the interlayer (11) through the steam mixing chamber (7) to preheat the tank body (1); S2, adding the material to be mixed into the tank body (1), then the controller controls the motor (6) and the main air inlet valve to start, and the stirring mechanism (2) rotates to mix the material. At the same time, steam is introduced into the liquid material in the tank body (1) through the internal steam heating mechanism to heat it; During the mixing process, the temperature sensor collects the temperature of the steam in the steam mixing chamber (7) in real time, and the controller controls the opening and closing of the second air intake valve or the third air intake valve according to the collected temperature, thereby adjusting the temperature of the steam in the steam mixing chamber (7).

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