Polyisobutylene water washing process waste heat utilization system

Abstract

The utility model belongs to polyisobutylene production application field especially relates to a kind of waste heat utilization systems for polyisobutylene washing process. Including washing device, waste water pool and hot water tank, there is waste water pipe in communication between washing device and waste water pool, there is hot water pipe in communication between hot water tank and washing device, there is also a first heat exchanger in communication on waste water pipe, there is also soft water inlet pipe and soft water outlet pipe on the first heat exchanger, the soft water outlet pipe is in communication with second heat exchanger, the second heat exchanger is in communication with hot water tank, there is also steam inlet pipe and condensate outlet pipe on the second heat exchanger. The utility model is implemented through the implementation of first heat exchanger, realizes the effective heat exchange of waste water heat energy, to achieve the purpose of reducing waste water temperature while improving the water inlet problem of soft water reentering second heat exchanger, simultaneously, through the implementation of second heat exchanger, the soft water after first heat exchange is continuously heated, to ensure that its temperature meets washing demand.

Description

Technical Field

[0001] This utility model belongs to the field of polyisobutylene production and application, and particularly relates to a waste heat utilization system for the polyisobutylene water washing process. Background Technology

[0002] Polyisobutylene is a high molecular weight polymer formed by the polymerization of isobutylene. Based on its molecular weight, it can be classified into low molecular weight, medium molecular weight, and high molecular weight products, and is widely used in lubricant additives, adhesives, and sealing materials. Its production process is mainly based on the principle of cationic polymerization.

[0003] After the polymerization of polyisobutylene (PIB) is completed, water washing is usually required to remove residual catalysts, co-catalysts, and water-soluble impurities from the product, which is a crucial step in PIB purification. The washing process uses hot soft water at approximately 80°C, resulting in wastewater with a temperature of about 50°C to 60°C. Traditionally, this wastewater is directly discharged into a wastewater tank, which not only wastes a significant amount of energy but also damages the tank due to the high temperature. Furthermore, the washing process requires a large amount of hot water, which reaches approximately 40°C after preheating in other processes. However, because the washing process requires pure water, the wastewater cannot be recycled. Therefore, effectively utilizing this wastewater is a problem that needs to be addressed. Utility Model Content

[0004] This invention addresses the technical problem of wastewater waste generated in existing polyisobutylene washing processes by proposing a waste heat utilization system for polyisobutylene washing processes that is reasonably designed, simple in structure, and can effectively achieve wastewater reuse.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a waste heat utilization system for a polyisobutylene water washing process, including a water washing device, a wastewater tank, and a hot water tank. A wastewater pipe connects the water washing device to the wastewater tank, and a hot water pipe connects the hot water tank to the water washing device. A primary heat exchanger is also connected to the wastewater pipe. The primary heat exchanger is also equipped with a soft water inlet pipe and a soft water outlet pipe. The soft water outlet pipe is connected to a secondary heat exchanger. The secondary heat exchanger is connected to the hot water tank, and a steam inlet pipe and a condensate outlet pipe are also provided on the secondary heat exchanger.

[0006] Preferably, the condensate outlet pipe is connected to the wastewater pipe, and the connection point between the condensate outlet pipe and the wastewater pipe is located between the water washing device and the primary heat exchanger.

[0007] Preferably, a water vapor separator is also provided between the condensate outlet pipe and the wastewater pipe.

[0008] Preferably, the water vapor separator includes a bucket-shaped device body, which is hollow, with a steam outlet pipe at the top, a condensate outlet pipe connected to one side of the device body, and a wastewater pipe connected to the bottom of the device body.

[0009] Preferably, the device body is also provided with a water distribution plate, which is located above the condensate outlet pipe, and the water distribution plate has air outlet holes evenly distributed on it.

[0010] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0011] This invention provides a waste heat recovery system for polyisobutylene washing processes. By implementing a primary heat exchanger, it achieves effective heat exchange of wastewater heat energy, thereby reducing the wastewater temperature. It also improves the water intake of soft water before it enters the secondary heat exchanger. Furthermore, the secondary heat exchanger allows for continued heating of the soft water after the primary heat exchange, ensuring that its temperature meets the washing requirements. Moreover, the implementation of the primary heat exchanger reduces the amount of steam used, achieving energy saving and emission reduction. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the waste heat recovery system for the polyisobutylene water washing process provided in Example 1;

[0014] Figure 2 A half-sectional view of the water vapor separator provided in Example 1;

[0015] In the above figures, 1 is the washing device; 2 is the wastewater tank; 3 is the hot water tank; 4 is the wastewater pipe; 5 is the primary heat exchanger; 51 is the soft water inlet pipe; 52 is the soft water outlet pipe; 6 is the secondary heat exchanger; 61 is the steam inlet pipe; 62 is the condensate outlet pipe; 7 is the water-vapor separator; 71 is the main body of the device; 72 is the steam outlet pipe; 73 is the water distribution plate; and 731 is the vent. Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0018] Example 1, such as Figure 1 , Figure 2 As shown, this embodiment aims to solve the technical problems of waste heat energy in the polyisobutylene washing process and its impact on flocculation in wastewater tank 2, thus affecting the treatment of wastewater tank 2. To this end, the waste heat utilization system for the polyisobutylene washing process provided in this embodiment includes a washing device 1, a wastewater tank 2, and a hot water tank 3. The washing device 1 is connected to the wastewater tank 2 by a wastewater pipe 4, and the hot water tank 3 is connected to the washing device 1 by a hot water pipe. The above structure is a common existing structure, and therefore, it will not be described in detail in this embodiment.

[0019] Considering that both the waste of heat and the flocculation effect in wastewater tank 2 boil down to one reason—the excessively high temperature of the wastewater—in this embodiment, to effectively utilize the heat of the wastewater, a primary heat exchanger 5 is connected to the wastewater pipe 4. The primary heat exchanger 5 is equipped with a soft water inlet pipe 51 and a soft water outlet pipe 52. This allows for the initial heating of the soft water using the primary heat exchanger 5. However, considering that the temperature of the wastewater after washing is approximately between 50°C and 60°C, the temperature of the soft water after heat exchange is insufficient to meet the washing requirements, a secondary heat exchanger 6 is connected to the soft water outlet pipe 52. The secondary heat exchanger 6 is connected to the hot water tank 3 and is equipped with a steam inlet pipe 61 and a condensate outlet pipe 62. The secondary heat exchanger 6 heats the soft water to 80°C using steam to meet the washing requirements.

[0020] With the above setup, the temperature of the wastewater after heat exchange is insufficient to affect the use of the flocculant, thus ensuring the normal treatment of wastewater in wastewater tank 2. Furthermore, it should be noted that the primary heat exchanger 5 and secondary heat exchanger 6 used in this embodiment are commonly available plate heat exchangers; of course, tubular heat exchangers can also be used. Unlike existing methods, since the wastewater contains a certain amount of acid, which is corrosive, the material of the primary heat exchanger 5 is preferably 304 or 316L stainless steel.

[0021] To reduce the corrosiveness of the wastewater, extend the service life of the primary heat exchanger 5, and prevent the wastewater temperature from dropping, in this embodiment, the condensate outlet pipe 62 is connected to the wastewater pipe 4, and the connection point between the condensate outlet pipe 62 and the wastewater pipe 4 is located between the water washing device 1 and the primary heat exchanger 5. Since steam heat exchange produces condensate, and the condensate itself has a higher temperature than the wastewater, mixing with the wastewater not only dilutes the acidity of the wastewater but also raises the temperature of the wastewater, thereby increasing the heat exchange capacity of the primary heat exchanger 5.

[0022] Considering that the product obtained after steam heat exchange is a mixture of condensate and steam, a water-vapor separator 7 is also provided between the condensate outlet pipe 62 and the wastewater pipe 4 in this embodiment. The water-vapor separator 7 is used to achieve steam-water separation. In this embodiment, the water-vapor separator 7 includes a device body 71 arranged in a bucket shape. The device body 71 is hollow, that is, the device body 71 is arranged in an inverted cone shape. This is to facilitate the reduction of steam velocity and achieve better water-vapor separation. A steam outlet pipe 72 is provided at the top of the device body 71, a condensate outlet pipe 62 is connected to one side of the device body 71, and the bottom of the device body 71 is connected to the wastewater pipe 4.

[0023] Considering that in addition to the condensate formed directly after passing through the secondary heat exchanger 6, the steam also carries a large amount of water vapor, a water distribution plate 73 is also provided inside the device body 71. The water distribution plate 73 is located above the condensate outlet pipe 62, and air outlet holes 731 are evenly distributed on the water distribution plate 73. In this way, when the steam passes through the water distribution plate 73, the water in the steam will adhere to the water distribution plate 73, and after a large amount has adhered, it will condense into water droplets and fall down.

[0024] The above setup effectively enables the reuse of wastewater heat while reducing the heating cost of soft water for washing.

[0025] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A polyisobutylene water washing process waste heat utilization system comprising a water washing device, a wastewater pool, and a hot water tank, a wastewater pipe being communicated between the water washing device and the wastewater pool, and a hot water pipe being communicated between the hot water tank and the water washing device, characterized in that, The wastewater pipe is also connected to a primary heat exchanger, which is equipped with a soft water inlet pipe and a soft water outlet pipe. The soft water outlet pipe is connected to a secondary heat exchanger, which is connected to a hot water tank. The secondary heat exchanger is also equipped with a steam inlet pipe and a condensate outlet pipe.

2. The polyisobutylene water wash process waste heat utilization system according to claim 1, characterized by, The condensate outlet pipe is connected to the wastewater pipe, and the connection point between the condensate outlet pipe and the wastewater pipe is located between the water washing device and the primary heat exchanger.

3. The waste heat recovery system for the polyisobutylene water washing process according to claim 2, characterized in that, A water vapor separator is also installed between the condensate outlet pipe and the wastewater pipe.

4. The waste heat recovery system for the polyisobutylene water washing process according to claim 3, characterized in that, The water vapor separator includes a bucket-shaped device body, which is hollow. A steam outlet pipe is provided at the top of the device body, a condensate outlet pipe is connected to one side of the device body, and a wastewater pipe is connected to the bottom of the device body.

5. The waste heat recovery system for the polyisobutylene water washing process according to claim 4, characterized in that, The device body is also provided with a water distribution plate, which is located above the condensate outlet pipe, and the water distribution plate has air outlet holes evenly distributed on it.

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