Waste heat recovery and cyclic utilization device in methylamine production

Abstract

In order to overcome the defects in the prior art, the waste heat recycling device in methylamine production comprises a kettle liquid waste heat drying box and a kettle liquid waste heat utilization barrel, a first cavity is formed in the kettle liquid waste heat drying box, and a second cavity is formed in the kettle liquid waste heat utilization barrel. The first cavity and the second cavity are isolated from each other. And a dry copper pipe and a plurality of protective net cages are arranged in the first cavity. Pipe bodies of the drying copper pipes are arranged around the outer surface of the protective net cage, and the outlet ends of the drying copper pipes are communicated with the connecting pipe. And a grid type drawer is slidably mounted in the protective net cage. A snakelike copper pipe is arranged in the second cavity, and a water injection pipe and a water drainage pipe which are communicated with the second cavity are arranged in the second cavity. The primary utilization of waste heat is realized through the kettle liquid waste heat drying box, and the secondary utilization of the waste heat is realized through the kettle liquid waste heat utilization cylinder.

Description

Technical Field

[0001] The utility model relates to the technical field of methylamine production, in particular to a waste heat recovery and recycling device in methylamine production. Background Technique

[0002] Methylamine is a basic organic chemical raw material and is widely used in pesticides, rubber, synthetic fuels, etc. When methylamine is produced by the prior art, a mixture of monomethylamine, dimethylamine, trimethylamine and some raw materials is often obtained. Therefore, a rectification tower needs to be used for rectification separation to obtain various types of methylamine products with purity meeting the product requirements.

[0003] Since the monomethylamine, dimethylamine, and trimethylamine products are collected as gas-phase components after rectification, a large amount of liquid-phase substances that need to be discharged will remain at the bottom of the rectification tower after the rectification tower rectifies the rectification raw material liquid. For the liquid-phase substances that need to be rectified again, they can be directly connected to the next-stage rectification tower through a heat preservation pipe. However, for the liquid-phase substances that need to be recycled, after being rectified and heated into high-temperature liquids and directly discharged to the next-stage treatment system, not only the heat energy in the liquid-phase substances is wasted, but sometimes additional cooling treatment is required, further wasting heat energy.

[0004] The prior art, such as the Chinese patent with the application number "202220876686.0", discloses a device for waste heat recovery and utilization of rectification tower bottom liquid in the methylamine rectification process, including a first heat collection box. A liquid inlet hopper is fixedly connected to the middle position at the top of the first heat collection box. This device can recover the heat in the bottom liquid twice by setting the first heat collection box and the second heat collection box, and can make full use of the heat in the bottom liquid. In addition, the buffer plate arranged in the heat conduction ball and the spiral blades in the heat transfer pipe can both increase the contact time between the bottom liquid and the coolant, and thus more heat can be recovered. The dispersion assembly can drive the impeller to rotate by using the impact force when the bottom liquid falls, providing power for the liquid distribution plate to rotate. The bottom liquid falling on the liquid distribution plate can be evenly sprayed on the inner wall of the heat conduction ball due to the centrifugal force, thereby increasing the contact area between the bottom liquid and the coolant in the liquid storage cavity and enabling full recovery of the heat in the bottom liquid.

[0005] When the existing rectification tower bottom liquid waste heat recovery and utilization device is in use, it guides the rectification tower bottom liquid through the spiral blades, so that the rectification tower bottom liquid flows along the surface of the spiral blades, and then the bottom liquid can exchange heat with the cold water in the second heat collection box through the spiral channel. However, when the rectification tower bottom liquid flows on the surface of the spiral blades, the contact area between the liquid and the spiral blades is large, but the contact area with the inner wall of the side heat transfer pipe is small, which results in poor heat exchange effect between the rectification tower bottom liquid and the heat transfer pipe and cannot achieve effective heat exchange.

[0006] In the prior art, the bottom liquid is splashed on the inner wall of the heat-conducting ball, and the cooling liquid in the liquid storage cavity can absorb the heat in the bottom liquid, and the heat is further transferred to the drying box through the heat transfer medium to dry the objects in the drying box. However, its heat export effect is poor, and the drying effect is not good. At the same time, in the prior art, it is impossible to effectively and intuitively judge the temperature of the heat exchange water and the bottom liquid, resulting in inconvenience in use. Summary of the Invention

[0007] To solve the deficiencies of the prior art, the present invention provides a waste heat recovery and recycling device in methylamine production, including: a bottom liquid waste heat drying box and a bottom liquid waste heat utilization cylinder arranged in sequence. A first cavity is provided in the bottom liquid waste heat drying box, and a second cavity is provided in the bottom liquid waste heat utilization cylinder. The first cavity and the second cavity are isolated from each other.

[0008] A drying copper tube and several protective net boxes arranged in a row are provided in the first cavity. The tube bodies of the drying copper tubes are respectively arranged around the outer surfaces of the protective net boxes. The inlet end of the drying copper tube is communicated with the bottom discharge pipe of the rectification tower through a water inlet pipe, and the outlet end is communicated with the inlet end of a connecting pipe. The connecting pipe penetrates and communicates the first cavity and the second cavity. A grid-type drawer is slidably installed inside the protective net box.

[0009] A serpentine copper tube is provided in the second cavity. The inlet end of the serpentine copper tube and the outlet end of the connecting pipe are communicated with subsequent devices through a discharge pipe. A water injection pipe and a drain pipe communicating with the second cavity are provided on the side wall of the second cavity in a way that the far ends are opposite to each other.

[0010] Further, the protective net box penetrates the first cavity along the cross-sectional direction of the first cavity. A grid-type drawer is provided at each of the two openings of the protective net box, and the opening and closing directions of the two grid-type drawers are opposite to each other.

[0011] Further, a handle is provided on the side wall of the grid-type drawer on the side of the outer wall of the first cavity.

[0012] Further, a second temperature sensor is provided in the grid-type drawer. A display mechanism is provided on the side wall of the grid-type drawer on the side of the outer wall of the first cavity. The second temperature sensor is signal-connected to the display mechanism.

[0013] Further, a first temperature sensor is provided in the second cavity. Flow control valves are respectively provided at positions close to the second cavity on the water injection pipe and the drain pipe. The first temperature sensor is signal-connected to the control signal end of the flow control valve through a PCL system.

[0014] Further, the tube bodies of the drying copper tubes are arranged in a swirling pattern on the upper and lower sides of the protective net box.

[0015] Furthermore, heat dissipation fins are provided on the outer side of the tube body of the drying copper tube close to the protective wire mesh box.

[0016] Furthermore, a flow blocking block is fixedly connected inside the serpentine copper tube.

[0017] Furthermore, heat insulation layers are covered on the outer walls of both the kettle liquid waste heat drying box and the kettle liquid waste heat utilization cylinder.

[0018] The beneficial effects of the present utility model are as follows:

[0019] 1. The present utility model heats the grid-type drawer through the drying copper tube, so as to realize the high-temperature treatment or high-temperature drying of the objects in the grid-type drawer, and realize the first utilization of the waste heat. In addition, heat exchange can also be carried out between the serpentine copper tube and the refrigerant in the kettle liquid waste heat utilization cylinder, so that the waste heat is transferred to other heat-requiring mechanisms through the refrigerant, realizing the secondary utilization of the waste heat.

[0020] 2. The tube body of the drying copper tube of the present utility model is arranged around the outer surface of the protective wire mesh box, so that the heat of the high-temperature kettle liquid flowing through the drying copper tube can be transferred to the grid-type drawer in the protective wire mesh box as much as possible, thereby improving the utilization rate of the first waste heat.

[0021] 3. The present utility model uses the serpentine copper tube to carry out heat exchange with the refrigerant, and the heat exchange area is relatively large, which can effectively improve the utilization rate of the second waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present utility model;

[0023] Figure 2 is a sectional view of the kettle liquid waste heat utilization cylinder of the present utility model;

[0024] Figure 3 is a sectional view of the waste heat utilization box of the present utility model;

[0025] Figure 4 is a schematic structural diagram of the grid-type drawer of the present utility model;

[0026] Figure 5 is a schematic structural diagram of the protective wire mesh box of the present utility model;

[0027] Figure 6 is a partial sectional view of the serpentine copper tube of the present utility model;

[0028] Figure 7 is a top view structural diagram of the drying copper tube of the present utility model;

[0029] Figure 8 is a side view structural diagram of the drying copper tube of the present utility model;

[0030] In the figure: 1. Residual heat drying oven for kettle liquid; 2. Residual heat utilization cylinder for kettle liquid; 3. Protective net box; 4. First temperature sensor; 5. Water inlet pipe; 6. Water injection pipe; 7. Drain pipe; 8. Discharge pipe; 9. Connecting pipe; 10. Serpentine copper pipe; 11. Flow baffle; 12. Heat insulation layer; 15. Drying copper pipe; 16. Heat dissipation fin; 17. Grid-type drawer. Detailed implementation mode

[0031] Now, the present utility model will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present utility model in a schematic manner, so they only show the components related to the present utility model.

[0032] Please note that the "upper", "lower", "left", "right", "top", "top end", "bottom end", "bottom" and other terms used in the present utility model to describe the positional relationship do not represent the absolute positional relationship between each module / component / assembly / part / element, but the relative positional relationship between each module / component / assembly / part / element.

[0033] Embodiment 1

[0034] A device for recycling residual heat in methylamine production, as Figures 1 to 5 , includes: a residual heat drying oven 1 for kettle liquid and a residual heat utilization cylinder 2 for kettle liquid arranged in sequence. A first cavity is provided in the residual heat drying oven 1 for kettle liquid, and a second cavity is provided in the residual heat utilization cylinder 2 for kettle liquid. The first cavity and the second cavity are isolated from each other.

[0035] A drying copper pipe 15 and several protective net boxes 3 arranged in a row are provided in the first cavity. The pipe body of the drying copper pipe 15 is respectively arranged around the outer surface of the protective net box 3. The inlet end of the drying copper pipe 15 is communicated with the bottom discharge pipe of the rectifying tower through a water inlet pipe 5, and the outlet end is communicated with the inlet end of a connecting pipe 9. The connecting pipe 9 penetrates and communicates the first cavity and the second cavity. A grid-type drawer 17 is slidably installed inside the protective net box 3.

[0036] A serpentine copper pipe 10 is provided in the second cavity. The inlet end of the serpentine copper pipe 10 is communicated with the outlet end of the connecting pipe 9 through a discharge pipe 8 and is communicated with a subsequent device. A water injection pipe 6 and a drain pipe 7 communicating with the second cavity are provided on the side wall of the second cavity in a way of being opposite to the far end.

[0037] The usage mode of this device is as follows: First, pull out the grid-type drawer 17, put the material to be dried in it, and then close the grid-type drawer 17. A low-temperature refrigerant, such as water, is injected into the second cavity from the water injection pipe 6. The heated refrigerant in the second cavity is discharged from the drain pipe 7 to a heat-requiring mechanism, such as a steam boiler.

[0038] At this time, the high-temperature kettle liquid continuously or intermittently flows through the drying copper pipe 15. The heat of the high-temperature kettle liquid radiates outward from the drying copper pipe 15, thereby heating the ambient temperature of the grid-type drawer 17 in the protective net box 3, and thus heating and drying the material to be dried in the grid-type drawer 17. After drying for a certain period of time, the grid-type drawer 17 is pulled out, the dried material to be dried is taken out, and a new material to be dried is replaced. The first utilization of the waste heat of the high-temperature kettle liquid is realized through the above method.

[0039] After the high-temperature kettle liquid passes through the end of the drying copper pipe 15, it enters the serpentine copper pipe 10 through the connecting pipe 9, and exchanges heat with the refrigerant in the second cavity, exchanging as much waste heat of the high-temperature kettle liquid as possible into the refrigerant, so that the refrigerant is heated. The second utilization of the waste heat of the high-temperature kettle liquid is realized through the above method.

[0040] Through the two-time utilization of waste heat, the waste heat of the high-temperature kettle liquid can be utilized as much as possible.

[0041] Embodiment 2

[0042] Based on the waste heat recovery and recycling device in methylamine production of Embodiment 1, as Figure 1 and Figure 3 shown, the protective net box 3 penetrates through the first cavity along the cross-sectional direction of the first cavity. One grid-type drawer 17 is respectively provided at the two openings of the protective net box 3, and the opening and closing directions of the two grid-type drawers 17 are opposite to each other.

[0043] This setting can make the grid-type drawer 17 occupy as much space in the first cavity as possible, so that the heated thermal environment can be fully utilized.

[0044] Embodiment 3

[0045] Based on the waste heat recovery and recycling device in methylamine production of Embodiment 1, as Figure 1 and Figure 3 shown, the grid-type drawer 17 is provided with a handle on the side wall on one side of the outer wall of the first cavity.

[0046] This setting can facilitate the user to pull out the grid-type drawer 17.

[0047] Embodiment 4

[0048] Based on the waste heat recovery and recycling device in methylamine production of Embodiment 1, a second temperature sensor is provided in the grid-type drawer 17, and a display mechanism is provided on the side wall on one side of the outer wall of the first cavity of the grid-type drawer 17. The second temperature sensor is in signal connection with the display mechanism.

[0049] This setting can detect the ambient temperature inside the grid-type drawer 17 through the second temperature sensor and display it on the display mechanism, enabling the user to relatively clearly know the ambient temperature inside the grid-type drawer 17, so as to select suitable materials to be dried and preliminarily judge the drying time based on the ambient temperature and the quantity of the materials to be dried.

[0050] Embodiment 5

[0051] Based on the waste heat recovery and recycling device in methylamine production of Embodiment 1, as Figure 2 shown, a first temperature sensor 4 is provided inside the second cavity, and flow control valves are respectively provided at positions of the water injection pipe 6 and the drain pipe 7 close to the second cavity. The first temperature sensor 4 is in signal connection with the control signal end of the flow control valve through the PCL system.

[0052] This setting obtains the temperature of the refrigerant inside the second cavity through the first temperature sensor 4, and thus controls the opening degree of the flow control valve through the PCL system. For example, if the refrigerant temperature is relatively high, it controls the opening degree of the flow control valve to increase, so that the flow rate of the refrigerant is accelerated, and more low-temperature refrigerant is replenished to absorb the heat energy of the high-temperature kettle liquid in the serpentine copper pipe 10. If the refrigerant temperature is relatively low, it controls the opening degree of the flow control valve to decrease, so that the flow rate of the refrigerant is slowed down, and the low-temperature main flow lasts longer so that the refrigerant can absorb the heat energy of the high-temperature kettle liquid in the serpentine copper pipe 10 for a longer time. Through this setting, the refrigerant can absorb the heat energy of the high-temperature kettle liquid in the serpentine copper pipe 10 as much as possible.

[0053] According to an embodiment of the present invention, as Figure 3 、 Figure 7 、 Figure 8 shown, the pipe bodies of the drying copper pipes 15 are arranged in a swirling pattern on the upper and lower sides of the protective net box 3 respectively. This setting can increase the heat dissipation area of the drying copper pipes 15 at the same protective net box 3, so that each protective net box 3 can have a relatively stable temperature environment.

[0054] According to an embodiment of the present invention, as Figure 7 shown, heat dissipation fins 16 are provided on the outer sides of the pipe bodies of the drying copper pipes 15 close to the protective net box 3. This setting can make the heat dissipation effect of the drying copper pipes 15 better.

[0055] According to an embodiment of the present invention, as Figure 6 shown, a baffle block 11 is fixedly connected inside the serpentine copper pipe 10. This setting can make the high-temperature kettle liquid inside the serpentine copper pipe 10 in a turbulent state, so that the contact time between the high-temperature kettle liquid and the pipe wall of the serpentine copper pipe 10 is increased, thereby improving the heat exchange effect between the pipe wall of the serpentine copper pipe 10 and the refrigerant.

[0056] According to an embodiment of the present utility model, as Figure 1 and Figure 2 shown, heat insulation layers 12 are covered on the outer walls of both the bottom liquid waste heat drying box 1 and the bottom liquid waste heat utilization cylinder 2. This setting can reduce the heat loss caused by the heat dissipation from the first cavity and the second cavity to the external environment.

[0057] Inspired by the above ideal embodiment based on the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A waste heat recovery and recycling device in methylamine production, characterized in that: include: A kettle liquid waste heat drying box (1) and a kettle liquid waste heat utilization cylinder (2) are arranged in sequence, wherein a first cavity is provided in the kettle liquid waste heat drying box (1), and a second cavity is provided in the kettle liquid waste heat utilization cylinder (2); the first cavity and the second cavity are isolated from each other; A drying copper tube (15) and a plurality of protective mesh boxes (3) are arranged in the first cavity; the tube bodies of the drying copper tubes (15) are arranged around the outer surfaces of the protective mesh boxes (3); the inlet end of the drying copper tube (15) is connected to the bottom liquid discharge pipe of the distillation tower through the water inlet pipe (5), and the outlet end is connected to the inlet end of the connecting pipe (9); the connecting pipe (9) penetrates and connects the first cavity and the second cavity; a grid-type drawer (17) is slidably installed inside the protective mesh box (3); A serpentine copper tube (10) is provided in the second cavity, and the inlet end of the serpentine copper tube (10) and the outlet end of the connecting tube (9) are connected to a subsequent device via a discharge pipe (8); a water injection pipe (6) and a drainage pipe (7) connected to the second cavity are provided on the side wall of the second cavity in a far-opposite manner.

2. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: The protective net box (3) penetrates the first cavity along the cross-sectional direction of the first cavity, and two openings of the protective net box (3) are respectively provided with a grid-type drawer (17), and the opening and closing directions of the two grid-type drawers (17) are opposite to each other.

3. The waste heat recovery and recycling device in methylamine production according to any one of claims 1 or 2, characterized in that: The grid-type drawer (17) is provided with a handle on a side wall located on one side of the outer wall of the first cavity.

4. The waste heat recovery and recycling device in methylamine production according to any one of claims 1 or 2, characterized in that: A second temperature sensor is provided in the grid-type drawer (17), a display mechanism is provided on a side wall of the grid-type drawer (17) located on one side of the outer wall of the first cavity, and the second temperature sensor is signal-connected to the display mechanism.

5. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: A first temperature sensor (4) is provided in the second cavity, and flow control valves are provided respectively at positions of the water injection pipe (6) and the drainage pipe (7) close to the second cavity; the first temperature sensor (4) is connected to a control signal end of the flow control valve via a PCL system.

6. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: The tube bodies of the drying copper tubes (15) are arranged in a spiral pattern on the upper and lower sides of the protective mesh box (3).

7. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: The tube body of the drying copper tube (15) is provided with heat dissipation fins (16) on the outer side of the tube body close to the protective mesh box (3).

8. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: A flow blocking block (11) is fixedly connected inside the serpentine copper tube (10).

9. The waste heat recovery and recycling device in methylamine production according to claim 1, characterized in that: The outer walls of the kettle liquid waste heat drying box (1) and the kettle liquid waste heat utilization cylinder (2) are both covered with a heat insulation layer (12).

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