Melamine production crystallizer

Abstract

The utility model discloses a melamine production crystallizer which comprises a crystallization lower end chamber, a crystallization upper end chamber is arranged above the crystallization lower end chamber in a penetrating mode, an air inlet is formed in the upper end of the crystallization upper end chamber, a discharging port is formed in the bottom of the crystallization lower end chamber in a penetrating mode, and a fixing shell is arranged at the lower end of the discharging port. A supporting frame is fixedly connected to the outer end of the crystallization lower end chamber, second flow dividing pipes are arranged at the two ends of the outer side of the crystallization lower end chamber, and high-temperature carrier gas of 400 DEG C is led out from an outlet pipe of a carrier gas preheater to conduct heat preservation on the structure part of the crystallization lower end chamber, so that the temperature of the equipment wall of the annular structure part in the crystallization lower end chamber is increased; and the whole device reduces the melamine wall-hanging speed of the reducing section of the crystallizer, reduces the frequency of material collapse of the crystallizer, reduces the blocking speed of the outlet pipe of the crystallizer, reduces the temperature of the outlet pipe of the crystallizer, and prolongs the operation cycle of the device.

Description

Technical Field

[0001] The utility model relates to the field of crystallizers, in particular to a melamine production crystallizer. Background Art

[0002] At present, the world's melamine production generally adopts the urea raw material route, which can usually be divided into three types: high-pressure liquid-phase quenching method, low-pressure liquid-phase quenching method, and low-pressure gas-phase quenching method. Among them, the high-pressure liquid-phase quenching method does not require a catalyst, the process equipment has high efficiency, a small volume, stable long-term operation, and stable product quality. However, the disadvantage is that a large amount of process wastewater will be generated during the production process, and the energy consumption and investment are relatively high. The low-pressure liquid-phase quenching method has relatively mild operating conditions, and the investment is lower than that of the high-pressure method. However, the disadvantage is that the refining process is complex, and the utilization ways and value of the high-water-content tail gas are limited. The low-pressure gas-phase quenching method has a simple process, small floor area, relatively low investment, does not generate process wastewater, and the tail gas is easy to recycle. However, its disadvantages are low efficiency, not easy to operate stably in the long term, and unstable product quality;

[0003] At present, most melamine devices adopt the low-pressure gas-phase quenching method, with low device efficiency, not easy to operate stably in the long term, and unstable product quality. How to reduce costs and increase efficiency, improve the operation cycle of the device and product quality to enhance the competitiveness of the enterprise itself is an urgent way for the low-pressure gas-phase quenching method melamine device;

[0004] At the large and small head of the middle part of the crystallizer, due to its structure being different from that of the upper and lower parts, the external jacket insulation cannot keep the temperature of the inner wall, resulting in melamine sticking to the wall and hanging materials at the large and small head. After reaching a certain thickness, it will fall off. This cycle occurs, resulting in unqualified product quality and blocking the outlet pipe of the crystallizer, affecting the operation days of the device. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a melamine production crystallizer, which solves the problem that at the large and small head of the middle part of the existing crystallizer, due to its structure being different from that of the upper and lower parts, the external jacket insulation cannot keep the temperature of the inner wall, resulting in melamine sticking to the wall and hanging materials at the large and small head.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme: a melamine production crystallizer, including a lower crystallization chamber, a upper crystallization chamber is penetrated through above the lower crystallization chamber, an air inlet is opened at the upper end of the upper crystallization chamber, a discharge port is penetrated through the bottom of the lower crystallization chamber, a fixed shell is arranged at the lower end of the discharge port, and a support frame is fixedly connected to the outer end of the lower crystallization chamber;

[0007] The outer sides of both ends of the lower crystallization chamber are provided with second shunt pipes, the other ends of the second shunt pipes are provided with intake pipes, the other two ends of the lower crystallization chamber are provided with first shunt pipes, and the other ends of the first shunt pipes are provided with outlet pipes.

[0008] As a further description of the above technical solution: A sealing plate is correspondingly installed inside the fixed shell, and a driving motor is fixedly connected to the outer end of the sealing plate.

[0009] As a further description of the above technical solution: The output end of the driving motor penetrates through the sealing plate and is provided with a rotating roller inward, and a plurality of stirring rods are fixedly connected to the outer end of the rotating roller.

[0010] As a further description of the above technical solution: Sliders are fixedly connected to both ends of the sealing plate, chutes are opened at both inner ends of the fixed shell, and the sliders are slidably connected inside the chutes.

[0011] As a further description of the above technical solution: Limit blocks are fixedly connected to the upper and lower ends of the sealing plate, limit grooves are opened at both ends of the fixed shell, and the limit blocks and the limit grooves correspond to each other.

[0012] As a further description of the above technical solution: A slot is opened on the fixed shell, a spring is fixedly connected to one inner end of the slot, a limiting plate is fixedly connected to the other end of the spring, a positioning block is fixedly connected to the other end of the limiting plate, a positioning groove is opened inside the limiting block, and the positioning block and the positioning groove correspond to each other.

[0013] The utility model has the following beneficial effects:

[0014] 1. Compared with the prior art, this melamine production crystallizer improves the temperature of the equipment wall of the circular structure part inside the lower crystallization chamber by introducing 400°C high-temperature carrier gas from the outlet pipe of the carrier gas preheater to heat the lower crystallization chamber structure part, so that it does not stick to the wall and hang materials like the upper part, reducing the rate of melamine wall hanging in the variable diameter section of the crystallizer, reducing the frequency of material collapse in the crystallizer, reducing the rate of blockage of the outlet pipe of the crystallizer, reducing the temperature of the outlet pipe of the crystallizer, and extending the operation cycle of the device;

[0015] 2. Compared with the prior art, this melamine production crystallizer solves the blockage problem that occurs when crystal particles are exported from the crystallization bin by arranging a stirring component below the discharge port. It mainly relies on the stirring effect to reduce the density of the discharged material, increase the gaps between particles, make the discharged material more orderly, and the stirring rod itself is made of silica gel material, which is relatively soft. Therefore, when it comes into contact with crystal particles, it will not damage the crystals, ensuring the integrity and quality of the crystal particles.

[0016] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present utility model. Description of the Drawings

[0017] The present utility model will be further described below in conjunction with the drawings and embodiments;

[0018] Figure 1 is a schematic diagram of the overall structure of the present utility model.

[0019] Figure 2 is a schematic diagram of the structure of the stirring assembly of the present utility model.

[0020] Figure 3 is the present utility model Figure 2 schematic diagram of the structure of B therein.

[0021] Figure 4 is a schematic diagram of the internal structure of the fixed shell of the present utility model;

[0022] Figure 5 is a schematic diagram of the pipeline connection structure of the present utility model.

[0023] Legend Explanation:

[0024] 1. Air inlet; 2. Upper crystallization chamber; 3. Lower crystallization chamber; 4. Support frame; 5. Fixed shell; 6. Discharge port; 7. Slide groove; 8. Slide block; 9. Limit block; 10. Sealing plate; 11. Positioning groove; 12. Limit groove; 13. Positioning block; 14. Groove; 15. Spring; 16. Limit plate; 17. Driving motor; 18. Stirring rod; 19. Rotating roller; 20. Exhaust pipe; 21. First shunt pipe; 22. Inlet pipe; 23. Second shunt pipe. Detailed Embodiment

[0025] This part will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the drawings. The role of the drawings is to supplement the description of the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but it cannot be understood as a limitation on the protection scope of the present utility model.

[0026] Referring to Figures 1-5 , an embodiment provided by the present utility model, a melamine production crystallizer, includes a lower crystallization chamber 3. An upper crystallization chamber 2 is penetrated through above the lower crystallization chamber 3. An air inlet 1 is opened at the upper end of the upper crystallization chamber 2. A discharge port 6 is penetrated through the bottom of the lower crystallization chamber 3. A fixed shell 5 is arranged at the lower end of the discharge port 6. A support frame 4 is fixedly connected to the outer end of the lower crystallization chamber 3. The crystallized material can be directly discharged through the discharge port 6;

[0027] On both outer ends of the lower crystallization chamber 3, second shunt pipes 23 are provided. The other end of each second shunt pipe 23 is provided with an intake pipe 22. On the other two ends of the lower crystallization chamber 3, first shunt pipes 21 are provided. The other end of each first shunt pipe 21 is provided with an outlet pipe 20. A sealing plate 10 is correspondingly installed inside the fixed housing 5. The outer end of the sealing plate 10 is fixedly connected to a driving motor 17. Finally, the steam generated by the four internal coolers of the urine washing tower is cooled again to reduce the temperature at the bottom of the urine washing tower, thereby reducing the crystallization temperature of the crystallizer, moving up its crystallization point, reducing the blockage rate of the outlet pipe of the crystallizer, controlling the rising rate of the temperature of the outlet pipe of the crystallizer at the same time, and prolonging the operation days of the device;

[0028] The output end of the driving motor 17 penetrates through the sealing plate 10 and is provided with a rotating roller 19 inside. A plurality of stirring rods 18 are fixedly connected to the outer end of the rotating roller 19. Starting the driving motor 17 can drive the rotating roller 19 and the stirring rods 18 to rotate, solving the blockage situation that occurs when the crystal particles are exported from the crystallization bin. It mainly relies on the stirring effect to reduce the density of the discharged material, increase the gaps between particles, make the discharged material more orderly, and the stirring rods 18 are made of silica gel material, and the texture is relatively soft. Therefore, when contacting the crystal particles, they will not damage the crystals, ensuring the integrity and quality of the crystal particles;

[0029] Both ends of the sealing plate 10 are fixedly connected with sliders 8. Both inner ends of the fixed housing 5 are provided with chutes 7. The sliders 8 are slidably connected inside the chutes 7. Through the chutes 7 and the sliders 8, it is convenient for the staff to align the stirring assembly with the fixed housing 5, thus facilitating its installation;

[0030] Both the upper and lower ends of the sealing plate 10 are fixedly connected with limit blocks 9. Limit grooves 12 are provided at both ends of the fixed housing 5. The limit blocks 9 and the limit grooves 12 correspond to each other. An opening groove 14 is provided on the fixed housing 5. One inner end of the opening groove 14 is fixedly connected with a spring 15. The other end of the spring 15 is fixedly connected with a limit plate 16. The other end of the limit plate 16 is fixedly connected with a positioning block 13. A positioning groove 11 is provided inside the limit block 9. The positioning block 13 and the positioning groove 11 correspond to each other. When the staff needs to disassemble and replace it, pull the limit plate 16 outwards. Under the action of the spring 15, the limit plate 16 can drive the positioning block 13 to contract inwards. At this time, the positioning block 13 leaves the inside of the positioning groove 11. The staff can pull the sealing plate 10 outwards to take out the entire stirring assembly and replace it, achieving the effect of stirring different doses of crystals and replacing different stirring rollers.

[0031] Working principle: When the device is in use, first, high-temperature carrier gas at 400°C is led out from the outlet pipe of the carrier gas preheater to heat-insulate the lower part of the crystallizer 3, thereby increasing the temperature of the equipment wall of the annular structure part inside the lower part of the crystallizer 3, so that it does not stick to the wall and accumulate materials like the upper part. The 400°C high-temperature carrier gas after heat insulation returns to the inlet of the hot gas cooler, and then enters through the inlet pipe 22 led out from the outlet pipe of the carrier gas preheater to the variable-diameter section of the crystallizer. The inlet pipe 22 is divided into four first shunt pipes 21 to enter the annular cavity of the variable-diameter section, and a thermometer is configured to introduce 400°C carrier gas. Two outlet pipes 20 are opened at a place 90 degrees away from the horizontal plane of the inlet pipe 22. After the outlet pipes 20 are aggregated, they are connected to the HC503 purge gas inlet for utilization, thereby reducing the rate of melamine wall sticking in the variable-diameter section of the crystallizer, reducing the frequency of material collapse in the crystallizer, reducing the rate of blockage of the outlet pipe of the crystallizer, reducing the temperature of the outlet pipe of the crystallizer, extending the operation cycle of the device, and after the materials inside the crystallizer are discharged after crystallization, they enter the inside of the fixed shell 5 through the discharge port 6. At this time, starting the drive motor 17 can drive the internal rotating roller 19 and the stirring rod 18 to rotate, solving the blockage situation that occurs when the crystal particles are exported from the crystallization bin, mainly relying on the stirring effect to reduce the density of the discharged materials, increasing the gaps between particles, making the discharged materials more orderly, and the stirring rod itself is made of silica gel material, with a relatively soft texture. Therefore, when it comes into contact with the crystal particles, it will not damage the crystals, ensuring the integrity and quality of the crystal particles.

[0032] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art in the said technical field, various changes can be made without departing from the gist of the present invention.

Claims

1. A melamine production crystallizer, comprising a lower crystallization chamber (3), characterized in that, Above the lower crystallization chamber (3), an upper crystallization chamber (2) is provided through it. An air inlet (1) is opened at the upper end of the upper crystallization chamber (2). At the bottom of the lower crystallization chamber (3), a discharge port (6) is provided through it. At the lower end of the discharge port (6), a fixed housing (5) is provided. The outer end of the lower crystallization chamber (3) is fixedly connected with a support frame (4). At both outer ends of the lower crystallization chamber (3), second shunt pipes (23) are opened. The other end of the second shunt pipe (23) is provided with an intake pipe (22). At the other two ends of the lower crystallization chamber (3), first shunt pipes (21) are opened. The other end of the first shunt pipe (21) is provided with an outlet pipe (20).

2. The melamine production crystallizer according to claim 1, characterized in that, Inside the fixed housing (5), a sealing plate (10) is correspondingly installed. The outer end of the sealing plate (10) is fixedly connected with a driving motor (17).

3. The melamine production crystallizer according to claim 2, characterized in that, The output end of the driving motor (17) penetrates the sealing plate (10) and is provided with a rotating roller (19) inward. A plurality of stirring rods (18) are fixedly connected to the outer end of the rotating roller (19).

4. A melamine production crystallizer according to claim 2, characterized in that, Both ends of the sealing plate (10) are fixedly connected with sliders (8). Inside both ends of the fixed housing (5), sliding grooves (7) are opened. The sliders (8) are slidably connected inside the sliding grooves (7).

5. The melamine production crystallizer according to claim 2, characterized in that, Both the upper and lower ends of the sealing plate (10) are fixedly connected with limiting blocks (9). Limiting grooves (12) are opened at both ends of the fixed housing (5). The limiting blocks (9) and the limiting grooves (12) correspond to each other.

6. The melamine production crystallizer according to claim 5, wherein, An opening groove (14) is opened on the fixed housing (5). At one inner end of the opening groove (14), a spring (15) is fixedly connected. The other end of the spring (15) is fixedly connected with a limiting plate (16). The other end of the limiting plate (16) is fixedly connected with a positioning block (13). A positioning groove (11) is opened inside the limiting block (9). The positioning block (13) and the positioning groove (11) correspond to each other.

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