Coking wastewater evaporation device based on coke oven flue equipment system

Abstract

The invention relates to a coking wastewater evaporation device based on a coke oven flue equipment system, which comprises a flue gas heating pipe section, a wastewater heating tank, a plurality of groups of working medium heat exchange pipe assemblies, a wastewater storage tank and a flash evaporation device, a waste water outlet of the waste water heating tank is connected with an atomization spraying device of the flash evaporation device, and the flue gas heating pipe section and the waste water heating tank are connected through a plurality of working medium heat exchange pipe assemblies to form a heat exchange unit. Waste water is heated through heat exchange of the working medium heat exchange pipe assembly and the waste water heating tank to form a high-pressure saturated solution, the high-pressure saturated solution enters the spraying pipeline located in the flash evaporation device and is sprayed out through the atomizing nozzle, the specific surface area of the waste water in the state at the moment is increased, the pressure is reduced, flash evaporation is conducted, and then the purpose of waste water concentration is achieved. And the defects of a traditional flue gas waste heat wastewater concentration mode are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of coking wastewater treatment equipment, and in particular to a coking wastewater evaporation device based on a coke oven flue equipment system. Background Art

[0002] Coking wastewater is produced in the process of coking, gas purification and chemical product recovery in the coking plant. It has a complex composition, high concentration of harmful substances, high toxicity and is difficult to treat. There are three main sources of coking wastewater: one is residual ammonia water, which accounts for more than half of the total wastewater; the second is wastewater generated in the gas purification process; and the third is wastewater generated in the refining process of chemical products such as tar and crude benzene. During the gas purification and chemical product refining process, various high-concentration process wastewaters separated from the process medium need to be mixed with residual ammonia water, discharged in the form of ammonia wastewater after ammonia evaporation, and then sent to the phenol-cyanide wastewater treatment station.

[0003] At present, the chemical industry generally uses the high-temperature waste heat of flue gas in the corresponding process system to concentrate the salt-containing wastewater for evaporation and concentration. This not only makes rational use of preheating resources, but also can achieve concentrated evaporation of wastewater. In view of the shortcomings of the traditional flue gas waste heat wastewater concentration method, in recent years, the emerging falling film evaporation technology has been widely used in the evaporation and concentration process of salt-containing wastewater, such as the fluoroplastic falling film evaporator disclosed in the publication number CN107986365A that uses flue gas waste heat to concentrate desulfurization wastewater, and uses flue gas to form a thin film of flowing water on the wall of the falling film tube for heating and evaporation. This technology provides a new idea for the use of flue gas waste heat to concentrate wastewater, avoiding the defects of traditional technology. However, the principle of flash evaporation is also used for liquid evaporation, and it has a wider applicability than the falling film evaporation technology. At present, it has not been further applied in the flue gas waste heat wastewater concentration process. Summary of the invention

[0004] In view of the above problems, the present invention proposes a coking wastewater evaporation device based on a coke oven flue equipment system, which utilizes the waste heat of flue gas to heat the wastewater heating tank to form a high-pressure saturated liquid, and then uses atomization spray technology to reduce the pressure to produce a flash evaporation effect to evaporate and concentrate the wastewater.

[0005] To achieve the above objectives, the following technical scheme is adopted: a coking wastewater evaporation device based on a coke oven flue equipment system, comprising a flue gas heating pipe section, a wastewater heating tank, several groups of working medium heat exchange pipe assemblies, a wastewater storage tank and a flash evaporation device, wherein:

[0006] The flue gas heating pipe section includes a heating pipe section main pipe and pipe interfaces at both ends;

[0007] The flash evaporation device comprises an evaporation tank body, and the steam tank body comprises an atomizing spray device, a steam outlet, a concentrated wastewater outlet and a mist collector. The steam outlet is located at the top, and the concentrated wastewater outlet is located at the bottom. The atomizing spray device and the mist collector are arranged on the transverse section of the evaporation tank body, and the mist collector is located above the atomizing spray device.

[0008] The wastewater storage tank is connected to the wastewater inlet of the wastewater heating tank through a delivery pump, the wastewater outlet of the wastewater heating tank is connected to the atomizing spray device of the flash evaporation device, and the flue gas heating pipe section and the wastewater heating tank are connected through several groups of working fluid heat exchange pipe assemblies to form a heat exchange unit.

[0009] The working fluid heat exchange tube assembly includes a heated tube section, a heat releasing tube section, an ascending tube, and a downcomer. The heated tube sections of the several groups of working fluid heat exchange tube assemblies are arranged in the flue gas heating tube section, and the heat releasing tube sections of the several groups of working fluid heat exchange tube assemblies are arranged in the wastewater heating tank. The heated tube section and the heat releasing tube section are connected through the ascending tube and the downcomer to form a circulation pipeline for the flow of the working fluid. The ascending tube allows the working fluid located in the heated tube section to flow to the heat releasing tube section after being heated, and the downcomer allows the working fluid located in the heat releasing tube section to flow to the heated tube section after heat exchange.

[0010] Furthermore, the heated pipe section is arranged on the longitudinal cross section of the flue gas heating pipe section in the flue gas flow direction.

[0011] Furthermore, the heat release pipe section is arranged on the longitudinal section of the wastewater heating tank in the wastewater flow direction.

[0012] Furthermore, the heated pipe section and the heat releasing pipe section have the same structure, both including a first flow direction transverse tube, a second flow direction transverse tube and a plurality of longitudinal tubes. The plurality of longitudinal tubes are evenly arranged between the first flow direction transverse tube and the second flow direction transverse tube. The first flow direction transverse tube is connected to the upper ends of the plurality of longitudinal tubes, and the second flow direction transverse tube is connected to the lower ends of the plurality of longitudinal tubes. The three form a connecting pipeline. The ascending tube is respectively connected to the first flow direction transverse tube of the heated pipe section and the heat releasing pipe section, and the descending tube is respectively connected to the second flow direction transverse tube of the heated pipe section and the heat releasing pipe section. The first flow direction transverse tube and the second flow direction transverse tube of the heated pipe section and the heat releasing pipe section are fixed on the pipe walls of their respective corresponding pipe sections.

[0013] Furthermore, a working medium control valve is arranged on the first flow direction transverse pipe of the heat release pipe section.

[0014] Furthermore, the longitudinal tubes of the heated tube section are finned tubes.

[0015] Furthermore, the atomizing spray device includes a spray pipe and a plurality of atomizing nozzles. The spray pipe is arranged on the transverse section of the evaporation tank body and fixed on the inner wall of the steam tank body. The plurality of atomizing nozzles are installed on the spray pipe. The wastewater outlet of the wastewater heating tank is connected to the spray pipe.

[0016] Furthermore, the pipe interfaces at both ends of the flue gas heating pipe section are variable diameter pipe interfaces, which are used to increase the flow rate of high-temperature flue gas in the flue gas heating pipe section.

[0017] Beneficial effects of the present invention: The present invention is designed to introduce a flue gas heating pipe section for introducing high-temperature flue gas in the flue gas main pipe, and a wastewater heating tank for forming a high-pressure saturated liquid container. A heat exchange unit is formed by arranging several groups of working fluid heat exchange tube assemblies between the two. The high-temperature flue gas is heated in the wastewater heating tank through the working fluid heat exchange tube assembly to form a high-pressure saturated solution, which is atomized by an atomizing spray device to increase its specific surface area and reduce its pressure, and flash vaporizes, thereby achieving the purpose of wastewater concentration and solving the drawbacks of the traditional flue gas waste heat wastewater concentration method. The working fluid heat exchange tube assembly of the present invention forms a circulation pipeline between the flue gas heating pipe section and the wastewater heating tank, so that the high-temperature flue gas circulates and heats the wastewater through the working fluid in the pipe, and the heating efficiency and evaporation efficiency are higher than those of the falling film evaporation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 for Figure 1 Middle AA view;

[0020] Figure 3 for Figure 2 Middle BB view;

[0021] Figure 4 It is a structural schematic diagram of a flash evaporation device;

[0022] Figure 5 This is a schematic diagram of the application of the present invention.

[0023] As shown in the figure: 1. Flue gas heating pipe; 2. Wastewater heating tank; 3. Working fluid heat exchange pipe assembly; 4. Wastewater storage tank; 5. Flash evaporation device; 6. Delivery pump; 30. Heating pipe section; 31. Heat release pipe section; 32. Rising pipe; 33. Downcomer; 34. Working fluid control valve; 100. Main pipe of heating pipe section; 101. Pipeline interface; 102. Fixed support; 200. Heating tank body; 201. Heating tank head; 202. Wastewater inlet; 203. Wastewater outlet; 204. Connecting support; 300. First flow direction transverse pipe; 301, second flow direction transverse pipe; 302, longitudinal tubes; 500, evaporator body; 501, tank body head; 502, conical head; 503, steam outlet; 504, concentrated wastewater outlet; 505, mist collector; 506, spray pipe; 507, atomizing nozzle; 508, mounting support; 900, flue gas main pipe; 901, flue gas branch pipe; 902, main pipe valve; 903, flue gas branch pipe inlet valve; 904, flue gas branch pipe outlet valve; 905, fan. DETAILED DESCRIPTION

[0024] Example 1

[0025] The following is further described with reference to the accompanying drawings: Figure 1-4 The schematic diagram of this example is shown in the figure. In this example, a coking wastewater evaporation device based on a coke oven flue equipment system includes a flue gas heating pipe section 1, a wastewater heating tank 2, several groups of working medium heat exchange tube assemblies 3, a wastewater storage tank 4 and a flash evaporation device 5.

[0026] The design of the flue gas heating pipe section 1 includes a heating pipe section main pipe 100 and pipe interfaces 101 at both ends. The heating pipe section main pipe 100 is designed as a cylindrical body, and a manhole is provided on the heating pipe section main pipe 100. The pipe interface 101 is a variable diameter pipe interface, which is used to increase the flow of high-temperature flue gas in the flue gas heating pipe section 1 in the coke oven flue equipment system. The heating pipe section main pipe 100 and the pipe interface 101 are connected with a flange structure, and a fixed support 102 is provided on the outer shell of the heating pipe section main pipe 100;

[0027] The design of the wastewater heating tank 2 is a cylindrical structure, including a heating tank body 200 and heating tank heads 201 at both ends. The heating tank body 200 and the heating tank heads 201 at both ends are connected by flanges. A manhole is provided on the heating tank body 200. The wastewater inlet 202 and the wastewater outlet 203 are respectively arranged on the heating tank heads 201 at both ends. A connecting support 204 is provided on the outer shell of the heating tank body 200.

[0028] The flash evaporation device 5 is designed as follows: the flash evaporation device 5 comprises an evaporation tank body 500, the upper end of the evaporation tank body 500 is a tank body head 501, the lower end is a conical head 502, a steam outlet 503 is arranged at the top of the tank body head 501, and a concentrated wastewater outlet 504 is arranged at the lower end of the conical head 502. An atomizing spray device and a mist catcher 505 are arranged inside the evaporation tank body 500. The atomizing spray device comprises a spray pipe 506 and a plurality of atomizing nozzles 507. The spray pipe 506 is arranged on the transverse section of the evaporation tank body 500 and fixed on the inner wall of the steam tank body 500. A plurality of atomizing nozzles 507 are installed on the spray pipe 506. The mist catcher 505 is also arranged on the transverse section of the evaporation tank body 500, located above the atomizing spray device, and fixed on the inner wall of the steam tank body 500. A mounting support 508 is provided on the outer shell of the evaporation tank body 500.

[0029] The design of the working fluid heat exchange tube assembly 3 includes a heated tube section 30, a heat releasing tube section 31, an ascending tube 32, and a downcomer 33. Several groups of heated tube sections 30 of the working fluid heat exchange tube assembly 3 are arranged in the flue gas heating tube section 1, and several groups of heat releasing tube sections 31 of the working fluid heat exchange tube assembly 3 are arranged in the wastewater heating tank 2. The heated tube section 30 and the heat releasing tube section 31 are connected through the ascending tube 32 and the downcomer 33 to form a circulation pipeline for the flow of the working fluid. The ascending tube 32 allows the working fluid in the heated tube section 30 to flow to the heat releasing tube section 31 after being heated, and the downcomer 33 allows the working fluid in the heat releasing tube section 31 to flow to the channel of the heated tube section 30 after heat exchange.

[0030] The heat receiving pipe section 30 and the heat releasing pipe section 31 have the same structure, both including a first flow direction transverse tube 300, a second flow direction transverse tube 301 and a plurality of longitudinal tubes 302. The plurality of longitudinal tubes 302 are evenly arranged between the first flow direction transverse tube 300 and the second flow direction transverse tube 301. The first flow direction transverse tube 300 is connected to the upper ends of the plurality of longitudinal tubes 302, and the second flow direction transverse tube 301 is connected to the lower ends of the plurality of longitudinal tubes 302. The three form a connecting pipeline. The longitudinal tubes 302 of the heat receiving pipe section 30 are finned tubes.

[0031] The wastewater storage tank 4 is connected to the wastewater inlet 202 of the wastewater heating tank 2 through the delivery pump 6, and the wastewater outlet 203 of the wastewater heating tank 2 is connected to the spray pipe 506 of the flash evaporation device 5. The flue gas heating pipe section 1 and the wastewater heating tank 2 are connected through a plurality of groups of working fluid heat exchange pipe assemblies 3 to form a heat exchange unit. The wastewater heating tank 2 is connected to the flue gas heating pipe section 1 through the connecting support 204. The specific arrangement scheme of the working fluid heat exchange pipe assembly 3 is to arrange the heated pipe sections 30 of the plurality of working fluid heat exchange pipe assemblies 3 in the flue gas flow direction of the flue gas heating pipe section 1. In the longitudinal cross section, the heat-releasing pipe section 31 is arranged on the longitudinal cross section of the wastewater flow direction of the wastewater heating tank 2, the ascending pipe 32 is respectively connected to the first flow direction transverse pipe 300 of the heating pipe section 30 and the heat-releasing pipe section 31, the downcomer 33 is respectively connected to the second flow direction transverse pipe 301 of the heating pipe section 30 and the heat-releasing pipe section 31, the first flow direction transverse pipe 300 and the second flow direction transverse pipe 302 of the heating pipe section 30 and the heat-releasing pipe 31 are fixed on the pipe walls of their respective corresponding pipe sections, and a working medium control valve 34 is set on the first flow direction transverse pipe 300 of the heat-releasing pipe section 31.

[0032] like Figure 5As shown, the present invention is applied in a coke oven flue equipment system, a section of flue gas branch pipe 901 is arranged on the pipe course of the flue gas main pipe 900, a main pipe valve 902 is arranged on the flue gas main pipe 900, which is used to control the passage of the flue gas main pipe 900 and control the high-temperature flue gas to flow into the flue gas branch pipe 901, a flue gas branch pipe inlet valve 903 and a flue gas branch pipe outlet valve 904 are arranged at the inlet and outlet of the flue gas branch pipe 901, respectively, the flue gas heating pipe section 1 of the present invention is connected to the flue gas branch pipe 901, and a fan 905 is arranged between the flue gas heating pipe section 1 and the outlet of the flue gas branch pipe 901. In this example, the flue gas branch pipe 901 is led out from the flue gas main pipe 900, and when the waste water is evaporated, the delivery pump 6 is started to introduce the waste water in the waste water storage tank 4 into the waste water heating tank 2, and the working medium is filled by controlling the working medium control valve 34, and the working medium is water. Adjust the main pipeline valve 902, open the flue gas branch pipe inlet valve 903 and the flue gas branch pipe outlet valve 904, start the fan 905, and introduce the high-temperature flue gas into the flue gas heating pipe section 1. The heated pipe section 30 located in the flue gas heating pipe section 1 vaporizes the working medium after being heated, and enters the heat release pipe section 31 located in the wastewater heating tank 2 through the ascending pipe 32. The working medium condenses after heat exchange and returns to the heated pipe section 30 along the descending pipe 33 to continue heating. This process forms a circulation loop, and the wastewater in the wastewater heating tank 2 is heated to form a high-pressure saturated solution. The high-pressure saturated solution enters the spray pipe 506 located in the flash evaporation device 5 and is sprayed through the atomizing nozzle 507, so that the specific surface area of ​​the wastewater in this state is increased, the pressure is reduced, and flash vaporization is performed. The steam is discharged upward from the steam outlet 503, passes through the mist collector 505, removes liquid droplets, and is used as a heating medium for heating. The concentrated wastewater is located at the bottom of the flash evaporation device 5 and is discharged through the concentrated wastewater outlet 504 for further treatment.

[0033] The present invention is not limited to this embodiment, and any equivalent concepts or changes within the technical scope disclosed by the present invention are included in the protection scope of the present invention.

Claims

1. A coking wastewater evaporation device based on a coke oven flue equipment system, characterized in that: It comprises a flue gas heating pipe section (1), a wastewater heating tank (2), a plurality of groups of working fluid heat exchange pipe assemblies (3), a wastewater storage tank (4) and a flash evaporation device (5), wherein: The flue gas heating pipe section (1) comprises a heating pipe section main pipe (100) and pipe interfaces (101) at both ends; The flash evaporation device (5) comprises an evaporation tank body (500), the evaporation tank body (500) comprises an atomizing spray device, a steam outlet (503), a concentrated wastewater outlet (504) and a mist collector (505), the steam outlet (503) is located at the top, the concentrated wastewater outlet (504) is located at the bottom, the atomizing spray device and the mist collector (505) are both arranged on the transverse section of the evaporation tank body (500), and the mist collector (505) is located above the atomizing spray device. The wastewater storage tank (4) is connected to the wastewater inlet (202) of the wastewater heating tank (2) via a delivery pump (6); the wastewater outlet (203) of the wastewater heating tank (2) is connected to the atomizing spray device of the flash evaporation device (5); the flue gas heating pipe section (1) and the wastewater heating tank (2) are connected via a plurality of groups of working medium heat exchange pipe assemblies (3) to form a heat exchange unit. The working medium heat exchange tube assembly (3) comprises a heat receiving tube section (30), a heat releasing tube section (31), an ascending tube (32), and a descending tube (33). The heat receiving tube sections (30) of the plurality of groups of working medium heat exchange tube assemblies (3) are arranged in the flue gas heating tube section (1), and the heat releasing tube sections (31) of the plurality of groups of working medium heat exchange tube assemblies (3) are arranged in the waste water heating tank (2). The heat receiving tube section (30) and the heat releasing tube section (31) are connected via the ascending tube (32) and the descending tube (33) to form a circulation pipeline for the flow of the working medium. The ascending tube (32) allows the working medium located in the heat receiving tube section (30) to flow to the heat releasing tube section (31) after being heated, and the descending tube (33) allows the working medium located in the heat releasing tube section (31) to flow to the channel of the heat receiving tube section (30) after heat exchange.

2. The coking wastewater evaporation device according to claim 1, characterized in that: The heated pipe section (30) is arranged on the longitudinal cross section of the flue gas heating pipe section (1) in the direction of the flue gas flow.

3. The coking wastewater evaporation device according to claim 2, characterized in that: The heat release pipe section (31) is arranged on the longitudinal cross section of the wastewater heating tank (2) in the wastewater flow direction.

4. The coking wastewater evaporation device according to claim 3, characterized in that: The heat receiving pipe section (30) and the heat releasing pipe section (31) have the same structure, and both include a first flow direction transverse pipe (300), a second flow direction transverse pipe (301) and a plurality of longitudinal tubes (302). The plurality of longitudinal tubes (302) are evenly arranged between the first flow direction transverse pipe (300) and the second flow direction transverse pipe (301). The first flow direction transverse pipe (300) is connected to the upper end of the plurality of longitudinal tubes (302). The second flow direction transverse pipe (301) is connected to the plurality of longitudinal tubes (302). 2) are connected at the lower ends, and the three form a communicating pipeline, the ascending pipe (32) is respectively connected to the first flow direction transverse pipe (300) of the heat receiving pipe section (30) and the heat releasing pipe section (31), and the descending pipe (33) is respectively connected to the second flow direction transverse pipe (301) of the heat receiving pipe section (30) and the heat releasing pipe section (31), and the first flow direction transverse pipe (300) and the second flow direction transverse pipe (301) of the heat receiving pipe section (30) and the heat releasing pipe section (31) are both fixed on the pipe wall of the corresponding pipe section.

5. The coking wastewater evaporation device according to claim 4, characterized in that: A working medium control valve (34) is provided on the first flow direction transverse pipe (300) of the heat release pipe section (31).

6. The coking wastewater evaporation device according to claim 5, characterized in that: The longitudinal tubes (302) of the heated tube section (30) are finned tubes.

7. The coking wastewater evaporation device according to any one of claims 1 to 6, characterized in that: The atomizing spray device comprises a spray pipe (506) and a plurality of atomizing nozzles (507); the spray pipe (506) is arranged on the transverse section of the evaporation tank body (500) and fixed on the inner wall of the evaporation tank body (500); the plurality of atomizing nozzles (507) are installed on the spray pipe (506); and the wastewater outlet (203) of the wastewater heating tank (2) is connected to the spray pipe (506).

8. The coking wastewater evaporation device according to claim 7, characterized in that: The pipe interfaces (101) at both ends of the flue gas heating pipe section (1) are variable diameter pipe interfaces, which are used to increase the flow rate of high-temperature flue gas in the flue gas heating pipe section (1).

Images