Device convenient for evaporation and circulation of fuming sulfuric acid

Abstract

The utility model relates to the field of sulfur trioxide production equipment, in particular to a device convenient for evaporation and circulation of fuming sulfuric acid, which comprises a nicotinic acid preheater, a nicotinic acid evaporator, a nicotinic acid circulating pump, a nicotinic acid circulating tank and pipelines for sequentially connecting the devices, the low-concentration smoke acid is fed into the nicotinic acid evaporator, sulfur trioxide gas obtained through evaporation is discharged, the low-concentration smoke acid returns to the nicotinic acid preheater, the nicotinic acid preheater is connected with the nicotinic acid circulating pump, the nicotinic acid circulating pump is connected with the nicotinic acid circulating tank, and the nicotinic acid circulating tank is connected with the nicotinic acid evaporator. Or a pipeline for connecting the nicotinic acid preheater and the nicotinic acid circulating pump is connected with a nicotinic acid circulating tank through a branch pipeline, so that the recycling of the low-concentration flue gas acid is realized, the heat energy consumption of the nicotinic acid preheater is effectively reduced through the subsequent conveying process of the low-concentration flue gas acid, and the low-concentration flue gas acid is conveyed into the nicotinic acid circulating tank for recycling. And the energy consumption management in the conveying process is greatly optimized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of fuming sulfuric acid production equipment, especially to a device convenient for fuming sulfuric acid evaporation circulation. BACKGROUND

[0002] Sulfur trioxide is an important chemical raw material, widely used in chemical fertilizer, petroleum, chemical industry, textile, metallurgy and other industries, especially in the production process of sulfuric acid, sulfur trioxide as the key intermediate product of preparing sulfuric acid, the efficient preparation and recovery of sulfur trioxide not only concerns the quality of the product, but also directly affects the control of production cost.

[0003] The traditional sulfur trioxide preparation process mainly depends on the evaporation of fuming sulfuric acid, the fuming sulfuric acid is evaporated through the evaporation of fuming sulfuric acid, the sulfur trioxide gas in the fuming sulfuric acid is evaporated, and the pure sulfur trioxide product is produced after condensation treatment.

[0004] In this preparation process, the problem of low energy utilization efficiency is gradually highlighted, especially in the treatment link of low-concentration fuming sulfuric acid after evaporation. The low-concentration fuming sulfuric acid after evaporation has high temperature and rich heat energy, and if the heat energy is directly discharged or treated, a large amount of energy will be wasted, so the technical scheme of sending the low-concentration fuming sulfuric acid into the fuming sulfuric acid preheater through the pipeline to exchange heat with the acid is adopted, which not only provides the necessary heat source for the preheater, but also improves the energy utilization efficiency to a certain extent.

[0005] The low-concentration fuming sulfuric acid can be sent back to the fuming sulfuric acid circulation tank for continuous absorption and utilization after heat exchange, but the viscosity of the low-concentration fuming sulfuric acid is high, which increases the resistance of the liquid flowing in the pipeline, so additional pump power is needed to send it back to the fuming sulfuric acid circulation tank for continuous circulation and absorption. If the low-concentration fuming sulfuric acid conveying speed is slow, it will not only affect the conveying efficiency of high-concentration fuming sulfuric acid, but also reduce the production rate of sulfur trioxide product. In this process, not only does the operation of the pump consume a large amount of electric energy, increasing the production cost, but also the energy efficiency and stability of the whole preparation system are negatively affected to a certain extent.

[0006] In summary, in order to further optimize the treatment process of fuming sulfuric acid, reduce energy consumption and improve energy utilization efficiency, a more convenient and efficient fuming sulfuric acid evaporation circulation production equipment is needed, which can significantly improve the conveying efficiency of low-concentration fuming sulfuric acid, reduce the operation consumption of the pump, and realize effective control of production cost while ensuring product quality. UTILITY MODEL CONTENT

[0007] In order to solve the problems mentioned in the background art and overcome the above shortcomings, the utility model provides the following technical scheme:

[0008] The device for facilitating the evaporation cycle of fuming sulfuric acid comprises a nicotinic acid preheater, a nicotinic acid evaporator, a nicotinic acid circulating pump, a nicotinic acid circulating tank, and pipelines connecting the above devices in sequence.

[0009] In the device for facilitating the evaporation cycle of fuming sulfuric acid, high-concentration nicotinic acid enters the nicotinic acid circulating tank through the inlet, the outlet of the nicotinic acid circulating tank is connected to the inlet of the nicotinic acid preheater through a pipeline, the outlet of the nicotinic acid preheater is connected to the bottom inlet of the nicotinic acid evaporator through a pipeline, the top of the nicotinic acid evaporator is provided with a sulfur trioxide gas outlet, the side of the top of the nicotinic acid evaporator is provided with a low-concentration nicotinic acid outlet, the low-concentration nicotinic acid outlet is connected to the low-concentration nicotinic acid inlet of the nicotinic acid preheater through a pipeline, the nicotinic acid preheater is also provided with a low-concentration nicotinic acid outlet, the low-concentration nicotinic acid outlet is connected to one end of the pipeline of the nicotinic acid circulating pump through a pipeline, the other end of the pipeline of the nicotinic acid circulating pump is connected to the inlet of the nicotinic acid circulating tank through a pipeline, and the pipeline connecting the low-concentration nicotinic acid outlet and the nicotinic acid circulating pump is also provided with another branch pipeline, which connects the low-concentration nicotinic acid outlet and the inlet of the nicotinic acid circulating tank.

[0010] Such a design provides two paths for the low-concentration nicotinic acid to circulate back from the nicotinic acid evaporator to the nicotinic acid circulating tank, which can be selected according to different situations. If the low-concentration nicotinic acid can flow to the nicotinic acid circulating tank from the low-concentration nicotinic acid outlet, it can directly flow back to the nicotinic acid circulating tank through the branch pipeline. If the flow rate of the low-concentration nicotinic acid is too slow to affect the transportation of high-concentration nicotinic acid, the pipeline provided with the nicotinic acid circulating pump can be selected to accelerate the flow of low-concentration nicotinic acid back to the nicotinic acid circulating tank. Both paths can also be opened at the same time to transport low-concentration nicotinic acid and improve the circulation efficiency of low-concentration nicotinic acid.

[0011] Further, the bottoms of all devices are considered to be arranged on the same horizontal plane, which is defined as a reference plane, and the bottom of the nicotinic acid evaporator is higher than the reference plane, i.e., the bottom of the nicotinic acid evaporator is higher than the bottoms of other devices in the device for facilitating the evaporation cycle of fuming sulfuric acid.

[0012] Further, the bottom of the nicotinic acid evaporator is 2 meters higher than the reference plane, i.e., the bottom of the nicotinic acid evaporator is 2 meters higher than the bottoms of other devices in the device for facilitating the evaporation cycle of fuming sulfuric acid.

[0013] By raising the bottom of the nicotinic acid evaporator, a natural liquid level difference is formed between the nicotinic acid evaporator and the subsequent connected devices, which can improve the flow rate of low-concentration nicotinic acid flowing to the nicotinic acid circulating tank through the branch pipeline, replace the use of the nicotinic acid circulating pump, save the power consumption of the nicotinic acid circulating pump, and be more conducive to energy saving.

[0014] Further, the nicotinic acid evaporator is provided with a high-concentration nicotinic acid conveying pipe connected with the bottom feeding port of the nicotinic acid evaporator, and the top of the high-concentration nicotinic acid conveying pipe is lower than the top of the nicotinic acid evaporator.

[0015] Further, the sulfur trioxide gas outlet is arranged at the top of the nicotinic acid evaporator, and the low-concentration nicotinic acid outlet is arranged at a region between the top of the high-concentration nicotinic acid conveying pipe and the top of the nicotinic acid evaporator.

[0016] Further, the nicotinic acid evaporator is further provided with a furnace gas inlet and a furnace gas outlet, and the furnace gas inlet and the furnace gas outlet are arranged at a position lower than the positions of the sulfur trioxide gas outlet and the low-concentration nicotinic acid outlet.

[0017] Further, the furnace gas inlet and the furnace gas outlet are arranged at the region provided with the high-concentration nicotinic acid conveying pipe.

[0018] Further, the device for facilitating the evaporation circulation of fuming sulfuric acid is provided with an adjusting valve arranged on each pipe.

[0019] Compared with the prior art, the device has the following beneficial effects:

[0020] 1. The device for facilitating the evaporation circulation of fuming sulfuric acid realizes the recycling of low-concentration nicotinic acid after the evaporation of high-concentration nicotinic acid, and the low-concentration nicotinic acid discharged from the nicotinic acid evaporator is sent into a nicotinic acid preheater, so that the heat energy of the low-concentration nicotinic acid is exchanged with the high-concentration nicotinic acid entering the nicotinic acid preheater, thereby effectively reducing the energy consumption of the nicotinic acid preheater, promoting the high-concentration nicotinic acid to enter the nicotinic acid evaporator for heating and evaporation, and further reducing the energy consumption of the evaporator.

[0021] 2. In order to optimize the recycling efficiency of low-concentration nicotinic acid, the bottom of the nicotinic acid evaporator is lifted by 2 meters compared with the reference surface, which is higher than the height of the bottom surfaces of other devices, and the height difference between the devices naturally forms a liquid level difference.

[0022] 3. The nicotinic acid evaporator uses furnace gas as a heat source to efficiently heat and evaporate high-concentration nicotinic acid. The furnace gas inlet and outlet are located in the area where the high-concentration nicotinic acid conveying pipe is installed, ensuring that the high-concentration nicotinic acid is fully heated during the conveying process, promoting the precipitation of sulfur trioxide gas. At the same time, the high-concentration nicotinic acid conveying pipe is designed to be lower than the top of the nicotinic acid evaporator, leaving a certain space between them to facilitate the smooth discharge of sulfur trioxide gas from the top of the evaporator. The outlet for low-concentration nicotinic acid is located between the high-concentration nicotinic acid conveying pipe and the top of the nicotinic acid evaporator, which does not affect the output of sulfur trioxide gas and ensures the smooth discharge of low-concentration nicotinic acid, achieving high efficiency and coordination in the entire evaporation cycle. Attached Figure Description

[0023] Figure 1 This is a production flow chart of Embodiment 1 of this utility model;

[0024] 1-Nicotinic acid circulation tank, 2-Nicotinic acid preheater, 3-Nicotinic acid evaporator, 4-Nicotinic acid circulation pump, 5-Pipeline, 6-Regulating valve, 7-Low concentration nicotinic acid outlet, 8-Sulfur trioxide gas outlet, 9-Furnace gas inlet, 10-Furnace gas outlet, 11-High concentration nicotinic acid conveying pipe, 12-Low concentration nicotinic acid feed inlet, 13-Low concentration nicotinic acid outlet, 14-Branch pipeline. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0027] Example 1

[0028] like Figure 1 The diagram shown is a flow chart of an apparatus for facilitating the evaporation and circulation of fuming sulfuric acid according to this application.

[0029] Initially, high-concentration nicotinic acid is input from the feed inlet of the nicotinic acid circulation tank 1. A pump is installed at the nicotinic acid circulation tank 1 to send the high-concentration nicotinic acid into the nicotinic acid preheater 2 for preheating. The preheated high-concentration nicotinic acid is sent from the pipeline into the nicotinic acid evaporator 3. The high-concentration nicotinic acid conveying pipe 11 in the nicotinic acid evaporator 3 is heated by the furnace gas. The furnace gas inlet 9 and the furnace gas outlet 10 are located at the same positions as the high-concentration nicotinic acid conveying pipe 11.

[0030] The sulfur trioxide gas evaporated in the nicotinic acid evaporator 3 is sent out from the sulfur trioxide gas discharge port 8 arranged at the top of the nicotinic acid evaporator 3, and the remaining low-concentration nicotinic acid is discharged from the low-concentration nicotinic acid discharge port 7 arranged at the side of the nicotinic acid evaporator 3. The low-concentration nicotinic acid is sent into the nicotinic acid preheater 2 through the low-concentration nicotinic acid feed port 12, and exchanges heat with the high-concentration nicotinic acid in the nicotinic acid preheater 2. After the heat exchange is completed, the high-concentration nicotinic acid is sent into the nicotinic acid evaporator 3, and the low-concentration nicotinic acid is discharged from the low-concentration nicotinic acid discharge port 13 into the conveying pipeline and is sent back into the nicotinic acid circulating tank 1.

[0031] Two transmission paths are arranged between the low-concentration nicotinic acid discharge port 13 and the nicotinic acid circulating tank 1. One of the two transmission paths is that the low-concentration nicotinic acid discharge port 13 is connected with the nicotinic acid circulating pump 4 through a pipeline, and the nicotinic acid circulating pump 4 is connected with the nicotinic acid circulating tank 1 through a pipeline, so as to complete the transmission of the low-concentration nicotinic acid. The other transmission path is that a branch pipeline 14 is arranged on the pipeline connecting the low-concentration nicotinic acid discharge port 13 with the nicotinic acid circulating pump 4, and the branch pipeline 14 is directly connected with the nicotinic acid circulating tank 1. The two pipelines can be flexibly selected to use any one of the pipelines or simultaneously open the two pipelines according to the needs.

[0032] The flexible design provides more ways for the transmission of the low-concentration nicotinic acid, reduces the use frequency of the nicotinic acid circulating pump 4, and reduces the energy consumption of the nicotinic acid circulating pump 4.

[0033] Example 2

[0034] On the basis of example 1, the branch pipeline 14 arranged on the pipeline connecting the low-concentration nicotinic acid discharge port 13 with the nicotinic acid circulating pump 4 is used to transmit the low-concentration nicotinic acid. However, due to the large viscosity of the low-concentration nicotinic acid, the natural flow speed of the low-concentration nicotinic acid is slow.

[0035] Generally, in the design of a factory building, in order to reasonably utilize the space of the factory building and meet the design aesthetics, the pipelines are generally arranged in a horizontal direction or a combination of a horizontal direction and a vertical direction. Therefore, the bottom surfaces of the connected devices are generally arranged on the same plane, and the plane is defined as a reference surface.

[0036] Therefore, in order to compensate for the slow natural flow speed of the low-concentration nicotinic acid, the bottom of the nicotinic acid evaporator 3 is lifted by 2 meters relative to the reference surface. The height difference between the nicotinic acid evaporator 3 and other devices naturally forms a liquid level difference, which provides power for the flow of the low-concentration nicotinic acid, improves the natural flow rate of the low-concentration nicotinic acid in the branch pipeline 14, and further reduces the dependence on the nicotinic acid circulating pump 4 in the circulation of the low-concentration nicotinic acid on the basis of example 1, which is more conducive to reducing or even avoiding the electric energy consumption of the nicotinic acid circulating pump 4.

[0037] Example 3

[0038] On the basis of embodiment 1 and embodiment 2, the high-concentration nicotinic acid conveying pipe 11 is arranged in the nicotinic acid evaporator 3, and a certain distance exists between the top of the high-concentration nicotinic acid conveying pipe 11 and the top of the nicotinic acid evaporator 3, and the low-concentration nicotinic acid discharge port 7 is arranged in the area.

[0039] The evaporation cycle production of sulfur trioxide is a continuous production line, and new high-concentration nicotinic acid continuously enters the nicotinic acid preheater 2 from the nicotinic acid circulating tank 1 and then enters the nicotinic acid evaporator 3. Such a design can first avoid that, when the amount of high-concentration nicotinic acid entering the nicotinic acid evaporator 3 is too large, the top sulfur trioxide gas discharge port 8 is blocked, and sulfur trioxide gas cannot be discharged. When the high-concentration nicotinic acid overflows to the area between the top of the high-concentration nicotinic acid conveying pipe 11 and the top of the nicotinic acid evaporator 3, the solution can be discharged through the low-concentration nicotinic acid discharge port 7 for recycling, thereby avoiding waste of raw materials.

[0040] The above only describes the preferred embodiments of the present application, and it should be noted that, for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A device for facilitating the evaporation and circulation of fuming sulfuric acid, the fuming sulfuric acid evaporation and circulation device comprising a nicotinic acid preheater (2), a nicotinic acid evaporator (3), a nicotinic acid circulation pump (4), a nicotinic acid circulation tank (1), and pipelines connecting the above devices in sequence, characterized in that: The outlet of the nicotinic acid circulation tank (1) is connected to the inlet of the nicotinic acid preheater (2) via a pipe. The outlet of the nicotinic acid preheater (2) is connected to the bottom feed port of the nicotinic acid evaporator (3) via a pipe. The top of the nicotinic acid evaporator (3) is provided with a sulfur trioxide gas outlet (8). The side of the top of the nicotinic acid evaporator is provided with a low-concentration nicotinic acid outlet (7). The low-concentration nicotinic acid outlet (7) is connected to the low-concentration nicotinic acid inlet (12) on the nicotinic acid preheater (2) via a pipe. Furthermore, a low-concentration nicotinic acid outlet (13) is provided on the nicotinic acid preheater (2). The low-concentration nicotinic acid outlet (13) is connected to one end of the nicotinic acid circulation pump (4) via a pipe. The other end of the nicotinic acid circulation pump (4) is connected to the inlet of the nicotinic acid circulation tank (1) via a pipe. Additionally, another branch pipe (14) is provided on the pipe connecting the low-concentration nicotinic acid outlet (13) and the nicotinic acid circulation pump (4), which is connected to the inlet of the nicotinic acid circulation tank (1).

2. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 1, characterized in that: The bottom surface of the nicotinic acid evaporator (3) is higher than the reference surface.

3. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 2, characterized in that: The bottom surface of the nicotinic acid evaporator (3) is 2 meters higher than the reference surface.

4. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 1, characterized in that: The nicotinic acid evaporator (3) is provided with a high-concentration nicotinic acid conveying pipe (11), which is connected to the bottom feed port of the nicotinic acid evaporator (3). The top of the high-concentration nicotinic acid conveying pipe (11) is lower than the top of the nicotinic acid evaporator (3).

5. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 4, characterized in that: The sulfur trioxide gas outlet (8) is located at the top of the nicotinic acid evaporator (3), and the low-concentration nicotinic acid outlet (7) is located in the area between the top of the high-concentration nicotinic acid conveying pipe (11) and the top of the nicotinic acid evaporator (3).

6. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 1, characterized in that: The nicotine evaporator (3) is also provided with a furnace gas inlet (9) and a furnace gas outlet (10). The furnace gas inlet (9) and the furnace gas outlet (10) are located at a lower position than the sulfur trioxide gas outlet (12) and the low-concentration nicotine discharge outlet (7).

7. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 6, characterized in that: The furnace gas inlet (9) and the furnace gas outlet (10) are located in the area where a high-concentration nicotine conveying pipe (11) is provided.

8. The apparatus for facilitating the evaporation and circulation of fuming sulfuric acid as described in claim 1, characterized in that: Each pipeline in the device is equipped with a separate regulating valve (6).

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