Device for recycling PTA (pure terephthalic acid) process wastewater for boiler flue gas desulfurization

Abstract

The utility model relates to the technical field of three-waste treatment, in particular to a device for recycling PTA (pure terephthalic acid) process wastewater for boiler flue gas desulfurization, which comprises a wastewater desulfurization tower, a desulfurization tower and a chimney, an upper inlet of the wastewater desulfurization tower is fixedly communicated with a process wastewater inlet pipeline, and a lower inlet of the wastewater desulfurization tower is fixedly communicated with a flue gas inlet pipeline. The device is reasonable and compact in structure and convenient to use, in order to reduce the usage amount of hydrochloric acid and sulfuric acid in a process wastewater treatment process, the process wastewater is combined with coal-fired boiler flue gas containing sulfur dioxide, so that the pH value alkalinity of the process wastewater containing sodium carbonate and sodium bicarbonate is reduced, meanwhile, the flue gas can be effectively desulfurized, and the environmental pollution is reduced. The use amount of calcium hydroxide used by the original flue gas desulfurization device is reduced, and the purposes of recycling waste resources and reducing the energy consumption of the device are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of three wastes treatment, and is a device for resource utilization of PTA process wastewater in boiler flue gas desulfurization. Background Technique

[0002] The existing PTA (purified terephthalic acid) main unit process wastewater contains two streams. One stream comes from the oxidation tail gas scrubbing tower, and its main components are sodium carbonate, sodium bicarbonate, sodium bromide, etc.; the other stream comes from the catalyst recovery unit after the extraction of the oxidation mother liquor, and its main components are sodium salts of organic acids, sodium carbonate, and sodium bicarbonate. In these two streams of wastewater, both contain sodium carbonate, sodium bicarbonate, and a large amount of sodium salts of organic acids, which is a liquid with high COD and great pH buffering capacity.

[0003] In the existing mainstream sewage process flow, these two streams of wastewater are introduced into sewage biochemical treatment. After anaerobic and aerobic biochemical treatment of COD, and then reverse osmosis to produce reclaimed water, and the reclaimed water is recycled to each water-using section of the device. The concentrated water of the reverse osmosis device evaporates into water vapor through multi-effect evaporation, and after salting out, it is treated as solid waste.

[0004] In order to balance the change of the system pH value in the sewage treatment process, in the sewage treatment section, in order to adjust the system pH value, a large amount of acidic materials such as hydrochloric acid and sulfuric acid need to be added before anaerobic, aerobic, and reverse osmosis to adjust the pH value to meet the normal operation requirements of the system.

[0005] At the same time, the flue gas of coal-fired boilers contains sulfur dioxide, and a large amount of calcium hydroxide is required for desulfurization treatment, resulting in high treatment costs. Summary of the Invention

[0006] The utility model provides a device for resource utilization of PTA process wastewater in boiler flue gas desulfurization, which overcomes the above-mentioned deficiencies of the prior art and can effectively solve the problems of high treatment costs existing in the need to add a large amount of acidic materials such as hydrochloric acid and sulfuric acid to the existing process wastewater and the need for desulfurization treatment of coal-fired boiler flue gas.

[0007] The technical solution of the utility model is realized by the following measures: A device for resource utilization of PTA process wastewater in boiler flue gas desulfurization includes a wastewater desulfurization tower, a desulfurization tower, and a chimney. The upper inlet of the wastewater desulfurization tower is fixedly connected to a process wastewater inlet pipeline, the lower inlet of the wastewater desulfurization tower is fixedly connected to a flue gas inlet pipeline, the top outlet of the wastewater desulfurization tower is fixedly connected to the inlet of the chimney through a first gas outlet pipeline, a first treatment pipeline is fixedly connected between the first gas outlet pipeline and the lower inlet of the desulfurization tower, a second gas outlet pipeline is fixedly connected between the top outlet of the desulfurization tower and the chimney, a spraying device is arranged inside the upper part of the wastewater desulfurization tower, and a spraying circulation pipeline is fixedly connected between the lower outlet of the wastewater desulfurization tower and the inlet of the spraying device.

[0008] The following is a further optimization and / or improvement of the above-mentioned utility model technical solution:

[0009] The above-mentioned spraying device includes an upper spraying component, a middle spraying component, and a lower spraying component that are arranged at intervals from top to bottom. The upper spraying component includes a first annular spray pipe, a first spray branch pipe, and a first spray pipeline. At least two horizontally arranged first spray branch pipes are fixedly connected at intervals inside the first annular spray pipe. A first spray pipeline is fixedly connected between the first annular spray pipe and the spray circulation pipeline. The middle spraying component includes a second annular spray pipe, a second spray branch pipe, and a second spray pipeline. At least two second spray branch pipes that are inclined to the right are fixedly connected at intervals up and down inside the second annular spray pipe. A second spray pipeline is fixedly connected between the second annular spray pipe and the spray circulation pipeline. The lower spraying component includes a third annular spray pipe, a third spray branch pipe, and a third spray pipeline. At least two third spray branch pipes that are inclined to the left are fixedly connected at intervals up and down inside the third annular spray pipe. A third spray pipeline is fixedly connected between the third annular spray pipe and the spray circulation pipeline.

[0010] A number of spray holes are provided at intervals on the above-mentioned first spray branch pipe, second spray branch pipe, and third spray branch pipe.

[0011] The above-mentioned spraying device further includes spray heads, and spray heads are fixedly installed on each spray hole.

[0012] A waste water outlet pipeline is fixedly connected to the spray circulation pipeline between the above-mentioned waste water desulfurization tower and the lower spraying component. A water inlet pipeline is fixedly connected to the upper inlet of the desulfurization tower, and a drainage pipeline is fixedly connected to the lower outlet of the desulfurization tower.

[0013] A circulation pump is provided on the spray circulation pipeline between the above-mentioned waste water desulfurization tower and the waste water outlet pipeline, and an induced draft fan is provided on the flue gas inlet pipeline.

[0014] A waste water alkali content detector is provided on the spray circulation pipeline between the above-mentioned waste water outlet pipeline and the waste water desulfurization tower, and a flue gas sulfur content detector is provided on the first gas outlet pipeline between the waste water desulfurization tower and the first treatment pipeline.

[0015] A filler layer is provided on the inner side of the middle part of the waste water desulfurization tower between the above-mentioned process waste water inlet pipeline and the flue gas inlet pipeline, and a filler layer is provided on the inner side of the middle part of the desulfurization tower between the water inlet pipeline and the first treatment pipeline. The filler layer is a staggered filler.

[0016] The utility model has a reasonable and compact structure and is convenient to use. In order to reduce the usage amounts of hydrochloric acid and sulfuric acid in the process waste water treatment process, the process waste water is combined with the coal-fired boiler flue gas containing sulfur dioxide, so that the pH alkalinity of the process waste water containing sodium carbonate and sodium bicarbonate is reduced. At the same time, it can effectively desulfurize the flue gas, reduce the usage amount of calcium hydroxide used in the original flue gas desulfurization device, achieve the reuse of waste resources, and achieve the purpose of reducing the energy consumption of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG Figure 1 is a schematic process flow diagram of the present utility model.

[0018] FIG Figure 2 is a bottom view structural schematic diagram of the upper spray assembly of the spray device in FIG Figure 1

[0019] FIG Figure 3 is a bottom view structural schematic diagram of the middle spray assembly of the spray device in FIG Figure 1

[0020] FIG Figure 4 is a bottom view structural schematic diagram of the lower spray assembly of the spray device in FIG Figure 1

[0021] FIG Figure 1 The codes in FIG are respectively: 1 is the waste water desulfurization tower, 2 is the desulfurization tower, 3 is the chimney, 4 is the process waste water inlet pipeline, 5 is the flue gas inlet pipeline, 6 is the first outlet pipeline, 7 is the first treatment pipeline, 8 is the second outlet pipeline, 9 is the spray circulation pipeline, 10 is the waste water alkali content detector, 11 is the flue gas sulfur content detector, 12 is the induced draft fan, 13 is the first annular spray pipe, 14 is the first spray branch pipe, 15 is the first spray pipeline, 16 is the second annular spray pipe, 17 is the second spray branch pipe, 18 is the second spray pipeline, 19 is the third annular spray pipe, 20 is the third spray branch pipe, 21 is the third spray pipeline, 22 is the spray hole, 23 is the waste water outlet pipeline, 24 is the inlet pipeline, 25 is the drainage pipeline, 26 is the circulation pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present utility model is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical solutions of the present utility model and the actual situation.

[0023] In the present utility model, unless otherwise specified, the used equipment and devices are all the existing well-known and commonly used equipment and devices in the art. For example, the waste water alkali content detector and the flue gas sulfur content detector can be existing well-known and commonly used detection equipment.

[0024] In the present utility model, for the convenience of description, the description of the relative position relationship of each component is carried out according to the layout mode of the attached drawings of the specification, such as: the position relationships of front, back, up, down, left, right, etc. are determined according to the layout direction of the attached drawings of the specification. Figure 1 of the specification. Figure 1

[0025] The present utility model will be further described below in conjunction with the embodiments and the attached drawings:

[0026] Embodiment 1: As shown in FIG Figure 1 ​​​​As shown in the figure, the device for recycling PTA process wastewater for flue gas desulfurization of boilers includes a wastewater desulfurization tower 1, a desulfurization tower 2, and a chimney 3. The upper inlet of the wastewater desulfurization tower 1 is fixedly connected to a process wastewater inlet pipeline 4, the lower inlet of the wastewater desulfurization tower 1 is fixedly connected to a flue gas inlet pipeline 5, the top outlet of the wastewater desulfurization tower 1 is fixedly connected to the inlet of the chimney 3 through a first gas outlet pipeline 6, a first treatment pipeline 7 is fixedly connected between the first gas outlet pipeline 6 and the lower inlet of the desulfurization tower 2, the top outlet of the desulfurization tower 2 is fixedly connected to the chimney 3 through a second gas outlet pipeline 8, a spraying device is arranged inside the upper part of the wastewater desulfurization tower 1, and a spraying circulation pipeline 9 is fixedly connected between the lower outlet of the wastewater desulfurization tower 1 and the inlet of the spraying device.

[0027] In the present utility model, the process wastewater is sent to the wastewater desulfurization tower 1, and then sent to the spraying device through the spraying circulation pipeline 9. The process wastewater is evenly sprayed by the spraying device. At the same time, the flue gas sent from the coal-fired boiler is sent to the wastewater desulfurization tower 1. The flue gas contacts the process wastewater countercurrently from bottom to top. Sulfur dioxide in the flue gas reacts with sodium carbonate and sodium bicarbonate in the process wastewater to be absorbed and converted into sodium sulfite. Then, sodium sulfite reacts with oxygen in the flue gas to produce sodium sulfate, effectively desulfurizing the flue gas. After the desulfurized flue gas meets the emission standards, it can be directly discharged to the chimney 3 or sent to the desulfurization tower 2 for secondary desulfurization. On the other hand, the usage amount of acidic materials such as hydrochloric acid and sulfuric acid used for treating the process wastewater is reduced, saving the sewage treatment cost of the process wastewater.

[0028] According to actual needs, the above device for recycling PTA process wastewater for flue gas desulfurization of boilers can be further optimized and / or improved:

[0029] Embodiment 2: The difference from Embodiment 1 is that as shown in Figs. Figure 1 、 2 3 and 4, the spraying device includes an upper spraying component, a middle spraying component, and a lower spraying component arranged at intervals from top to bottom. The upper spraying component includes a first annular spray pipe 13, a first spray branch pipe 14, and a first spray pipeline 15. At least two horizontally arranged first spray branch pipes 14 are fixedly connected at intervals inside the first annular spray pipe 13. A first spray pipeline 15 is fixedly connected between the first annular spray pipe 13 and the spraying circulation pipeline 9. The middle spraying component includes a second annular spray pipe 16, a second spray branch pipe 17, and a second spray pipeline 18. At least two second spray branch pipes 17 inclined to the right are fixedly connected at intervals up and down inside the second annular spray pipe 16. A second spray pipeline 18 is fixedly connected between the second annular spray pipe 16 and the spraying circulation pipeline 9. The lower spraying component includes a third annular spray pipe 19, a third spray branch pipe 20, and a third spray pipeline 21. At least two third spray branch pipes 20 inclined to the left are fixedly connected at intervals up and down inside the third annular spray pipe 19. A third spray pipeline 21 is fixedly connected between the third annular spray pipe 19 and the spraying circulation pipeline 9.

[0030] During use, by staggering the upper and lower positions of the first spray branch pipe 14, the second spray branch pipe 15, and the third spray branch pipe 17, the process wastewater can be sprayed in a staggered and uniform manner, effectively contacting the flue gas.

[0031] Example 3: The difference from Example 2 is that as shown in the appendix Figure 1 , 2 a number of spray holes 22 are provided at intervals on the first spray branch pipe 14, the second spray branch pipe 17, and the third spray branch pipe 20.

[0032] Example 4: The difference from Example 3 is that as required, the spray device further includes spray heads, and spray heads are fixedly installed on each spray hole 22.

[0033] Example 5: The difference from Example 4 is that as shown in the appendix Figure 1 a wastewater outlet pipeline 23 is fixedly connected to the spray circulation pipeline 9 between the wastewater desulfurization tower 1 and the lower spray assembly, a water inlet pipeline 24 is fixedly connected to the upper inlet of the desulfurization tower 2, and a drainage pipeline 25 is fixedly connected to the lower outlet of the desulfurization tower 2.

[0034] During use, when the alkali content in the process wastewater is higher than the set value, the process wastewater is sent to the spray device for circulation through the spray circulation pipeline 9. When the alkali content in the process wastewater is lower than the set value, the process wastewater is sent for post-treatment after passing through the spray circulation pipeline 9 and the wastewater outlet pipeline 23; when the sulfur content in the flue gas after being treated by the wastewater desulfurization tower 1 is higher than the set value, it is sent to the desulfurization tower 2 for secondary desulfurization, and the alkali solution (calcium hydroxide solution) is sent to the desulfurization tower 2 through the water inlet pipeline 24 for secondary treatment. When the sulfur content in the flue gas after being treated by the wastewater desulfurization tower 1 is lower than the set value, the treated flue gas is sent to the chimney 3 through the first gas outlet pipeline 6.

[0035] Example 6: The difference from Example 5 is that as shown in the appendix Figure 1 a circulation pump 26 is provided on the spray circulation pipeline 9 between the wastewater desulfurization tower 1 and the wastewater outlet pipeline 23, and a draft fan 12 is provided on the flue gas inlet pipeline 5.

[0036] Example 7: The difference from Example 5 and Example 6 is that as shown in the appendix Figure 1 a wastewater alkali content detector 10 is provided on the spray circulation pipeline 9 between the wastewater outlet pipeline 23 and the wastewater desulfurization tower 1, and a flue gas sulfur content detector 11 is provided on the first gas outlet pipeline 6 between the wastewater desulfurization tower 1 and the first treatment pipeline 7.

[0037] During use, the alkali content in the process wastewater is detected by the wastewater alkali content detector 10, and the sulfur content in the flue gas is detected by the flue gas sulfur content detector 11.

[0038] Example 8: The difference between Example 5 and Example 7 is that as required, a packing layer is provided inside the middle part of the waste water desulfurization tower 1 between the process waste water inlet pipeline 4 and the flue gas inlet pipeline 5, and a packing layer is provided inside the middle part of the desulfurization tower 2 between the inlet pipeline 24 and the first treatment pipeline 7. The packing layer is a staggered packing. As required, the packing material is PTFE, PP or other corrosion-resistant plastics.

[0039] During use, due to the provided staggered packing, it has the effects of small ventilation resistance, strong hydrophilicity and large contact area, thereby improving the desulfurization effect.

[0040] As required, on each pipeline and equipment of the device for resource utilization of PTA process waste water for boiler flue gas desulfurization, conventional valves, thermometers, pressure gauges, etc. well-known and commonly used in the art can also be provided according to production needs.

[0041] The above technical features constitute the embodiments of the present utility model, which have strong adaptability and implementation effects. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0042] The usage process of the embodiment of the present utility model: First, the process waste water is sent to the waste water desulfurization tower 1 through the process waste water inlet pipeline 4, and then sent to the spraying device through the spraying circulation pipeline 9. The process waste water is evenly sprayed through the first spraying branch pipe 14, the second spraying branch pipe 15 and the third spraying branch pipe 17. At the same time, the flue gas sent from the coal-fired boiler is sent to the waste water desulfurization tower 1 through the flue gas inlet pipeline 5. The flue gas contacts the process waste water countercurrently from bottom to top. After the desulfurized flue gas is detected by the flue gas sulfur content detector 11, when the sulfur content in the flue gas is lower than the set value, it is directly sent out through the first outlet pipeline 6. When the sulfur content in the flue gas is higher than the set value, the flue gas is sent to the desulfurization tower 2 through the first outlet pipeline 6 and the first treatment pipeline 7 for secondary desulfurization, and then the flue gas after secondary desulfurization is sent to the chimney 3 through the second outlet pipeline 8. In addition, the process waste water on the circulating spraying pipeline is detected by the waste water alkali content detector 10. When the alkali content in the process waste water is higher than the set value, the process waste water is sent to the spraying device for circulation. When the alkali content in the process waste water is lower than the set value, the process waste water is sent out through the waste water outlet pipeline 23 for post-treatment.

Claims

1. A device for recycling PTA process wastewater for boiler flue gas desulfurization, characterized in that It includes a wastewater desulfurization tower, a desulfurization tower and a chimney. The upper inlet of the wastewater desulfurization tower is fixedly connected with a process wastewater inlet pipeline, the lower inlet of the wastewater desulfurization tower is fixedly connected with a flue gas inlet pipeline, a first air outlet pipeline is fixedly connected between the top outlet of the wastewater desulfurization tower and the chimney inlet, a first treatment pipeline is fixedly connected between the first air outlet pipeline and the lower inlet of the desulfurization tower, a second air outlet pipeline is fixedly connected between the top outlet of the desulfurization tower and the chimney, a spray device is provided on the inner side of the upper part of the wastewater desulfurization tower, and a spray circulation pipeline is fixedly connected between the lower outlet of the wastewater desulfurization tower and the inlet of the spray device.

2. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 1, characterized in that The spray device includes an upper spray assembly, a middle spray assembly and a lower spray assembly which are spaced apart from top to bottom. The upper spray assembly includes a first annular nozzle, a first spray branch and a first spray pipeline. At least two first horizontally arranged first spray branches are fixedly connected at intervals in the first annular nozzle, and the first spray pipeline is fixedly connected between the first annular nozzle and the spray circulation pipeline. The middle spray assembly includes a second annular nozzle, a second spray branch and a second spray pipeline. At least two right-inclined second spray branches are fixedly connected in the second annular nozzle at intervals from top to bottom, and the second annular nozzle is fixedly connected to the spray circulation pipeline. The lower spray assembly includes a third annular nozzle, a third spray branch and a third spray pipeline. At least two left-inclined third spray branches are fixedly connected in the third annular nozzle at intervals from top to bottom, and the third spray pipeline is fixedly connected between the third annular nozzle and the spray circulation pipeline.

3. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 2, characterized in that The first spray branch pipe, the second spray branch pipe and the third spray branch pipe are all provided with a plurality of spray holes at intervals.

4. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 3, characterized in that The spray device also includes a spray head, and each spray hole is fixedly mounted with a spray head.

5. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 2, 3 or 4, characterized in that The spray circulation pipeline between the wastewater desulfurization tower and the lower spray assembly is fixedly connected with a wastewater outlet pipeline, the upper inlet of the desulfurization tower is fixedly connected with a water inlet pipeline, and the lower outlet of the desulfurization tower is fixedly connected with a drainage pipeline.

6. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 5, characterized in that A circulation pump is provided on the spray circulation pipeline between the wastewater desulfurization tower and the wastewater outlet pipeline, and an induced draft fan is provided on the flue gas inlet pipeline.

7. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 5, characterized in that A wastewater alkali content detector is provided on the spray circulation pipeline between the wastewater outlet pipeline and the wastewater desulfurization tower, and a flue gas sulfur content detector is provided on the first gas outlet pipeline between the wastewater desulfurization tower and the first treatment pipeline.

8. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 6, characterized in that A wastewater alkali content detector is provided on the spray circulation pipeline between the wastewater outlet pipeline and the wastewater desulfurization tower, and a flue gas sulfur content detector is provided on the first gas outlet pipeline between the wastewater desulfurization tower and the first treatment pipeline.

9. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 6, 7 or 8, characterized in that A packing layer is provided on the inner side of the middle of the wastewater desulfurization tower between the process wastewater inlet pipeline and the flue gas inlet pipeline, and a packing layer is provided on the inner side of the middle of the desulfurization tower between the inlet pipeline and the first treatment pipeline. The packing layer is an oblique staggered packing.

10. The device for utilizing PTA process wastewater for boiler flue gas desulfurization according to claim 5, characterized in that A packing layer is provided on the inner side of the middle of the wastewater desulfurization tower between the process wastewater inlet pipeline and the flue gas inlet pipeline, and a packing layer is provided on the inner side of the middle of the desulfurization tower between the inlet pipeline and the first treatment pipeline. The packing layer is an oblique staggered packing.

Images