PTA (pure terephthalic acid) sewage pretreatment device

Abstract

The utility model relates to the technical field of sewage treatment, in particular to a PTA (pure terephthalic acid) sewage pretreatment device, which is characterized in that condensate conveying pipes are arranged at the bottoms of a No.1 condensate collecting tank and a No.2 condensate collecting tank and are connected to a wastewater header pipe, a process wastewater collecting pipe is connected onto the wastewater header pipe, the wastewater header pipe extends into a wastewater collecting pool, and the wastewater collecting pool is connected with a wastewater collecting tank. The wastewater header pipe is connected to a wastewater pretreatment constant-temperature tank, the wastewater pretreatment constant-temperature tank is connected to a wastewater homogeneous regulation tank through a constant-temperature wastewater delivery pipe, the wastewater homogeneous regulation tank is connected with a heat exchanger through a homogeneous wastewater delivery pipe, and a wastewater outlet end of the heat exchanger is connected to an anaerobic system. According to the PTA sewage pretreatment device disclosed by the utility model, condensate, process wastewater and PTA wastewater are reasonably mixed and are mixed in the constant-temperature tank and the homogeneous adjusting tank, and finally, the PTA wastewater entering an anaerobic system can be in a required temperature range through heat exchange, so that the stability of wastewater treatment is improved, and the PTA sewage pretreatment device is low in energy consumption and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a PTA sewage pretreatment device. Background Art

[0002] At present, the various process wastewaters discharged during the operation of modern large-scale PTA (2.5 million tons / year) plants and the production of auxiliary systems have high organic matter concentration and high COD (chemical oxygen demand). In order to achieve good COD removal effect, a small-footprint and highly efficient anaerobic and aerobic combined biological treatment technology is adopted in PTA wastewater treatment.

[0003] In the anaerobic reactor, the organic pollutants in the process wastewater are fully in contact with the anaerobic activated sludge and are biodegraded to produce a large amount of biogas. The biogas is collected and recycled as a clean energy source. At the same time, the wastewater is purified and sent to the downstream aerobic process for further deep conversion and treatment. Finally, it is recycled and discharged after meeting the standards.

[0004] Currently, medium-temperature (33°C-38°C) anaerobic reactors are commonly used in actual production.

[0005] The medium-temperature anaerobic reactor has special requirements for the wastewater temperature. The suitable temperature for sludge bacteria in the reactor is 33℃-38℃. At this temperature, the bacteria are active, the conversion rate is high, and the gas production is large. The anaerobic digestion system is very sensitive to sudden changes in temperature. The temperature fluctuation has a great influence on the removal rate. If the temperature changes too much, the system will stop producing gas and the granular sludge will be inactivated. Therefore, ensuring the uniform and constant temperature of the anaerobic reactor material has become the top priority for the anaerobic reaction conversion efficiency.

[0006] In addition to high organic matter concentration, wastewater in PTA production has a large temperature gradient, ranging from room temperature to over 100°C, and is affected by seasonal ambient temperature and suddenness. To control the temperature of pretreated wastewater entering the anaerobic reactor within a suitable temperature range, additional heat or cooling is required, which consumes a lot of energy and energy consumption, resulting in a significant increase in wastewater treatment costs.

[0007] The steam generator in the PTA unit discharges condensate and low-grade steam condensate wastewater, and the high-temperature process wastewater is directly discharged into the on-site ditch system without effective recycling, resulting in huge waste.

[0008] In summary, keeping the wastewater temperature feeding the anaerobic reactor constant within the optimal range, avoiding sudden temperature changes that lead to a decrease in anaerobic reaction conversion efficiency, efficiently recycling the wastewater heat in the PTA device, and reducing the energy consumption cost of PTA wastewater pretreatment are important technical issues that people in the wastewater pretreatment field currently need to solve. Utility Model Content

[0009] In order to solve the above technical deficiencies, the utility model provides a PTA wastewater pretreatment device, which can perform constant temperature treatment on PTA wastewater to ensure that the wastewater temperature is within a reasonable range when entering the anaerobic system, thereby improving the stability of PTA wastewater treatment.

[0010] The utility model discloses a PTA sewage pretreatment device, comprising a No. 1 condensate collection tank, a No. 2 condensate collection tank, a wastewater collection pool, a wastewater main pipe, a wastewater pretreatment constant temperature tank, a wastewater homogenization regulating tank and a heat exchanger, a condensate delivery pipe is arranged at the bottom of the No. 1 condensate collection tank and the No. 2 condensate collection tank, a condensate delivery pump is arranged on the condensate delivery pipe, a condensate delivery control valve is arranged after the condensate delivery pipes are merged, and the condensate delivery pipes are connected to the wastewater main pipe, a process wastewater collection pipe is connected to the wastewater main pipe, a temperature sensor is arranged on the process wastewater collection pipe, the wastewater main pipe extends into the wastewater collection pool, and a wastewater delivery pump, a filter, a pressure transmitter, a mixer are arranged on the wastewater main pipe in sequence. The process wastewater collecting pipe and the condensate delivery pipe are connected to the wastewater main pipe between the pressure transmitter and the mixer, the wastewater main pipe is connected to the wastewater pretreatment constant temperature tank, a mixing ejector is arranged on the wastewater main pipe in the wastewater pretreatment constant temperature tank, the wastewater pretreatment constant temperature tank is connected to the wastewater homogenization adjustment tank through a constant temperature wastewater delivery pipe, a constant temperature wastewater delivery pump is arranged on the constant temperature wastewater delivery pipe, the wastewater homogenization adjustment tank is connected to the heat exchanger through a homogenous wastewater delivery pipe, a homogenous wastewater delivery pump is arranged on the homogenous wastewater delivery pipe, the wastewater outlet end of the heat exchanger is connected to the anaerobic system, a cooling water and steam inlet pipe is arranged on the heat exchanger, and a cooling water and steam outlet pipe is arranged on the heat exchanger.

[0011] There are two wastewater pretreatment thermostatic tanks, and the wastewater main pipes are connected to the two wastewater pretreatment thermostatic tanks respectively. Mixing ejectors are arranged on the wastewater main pipes in the wastewater pretreatment thermostatic tanks, and temperature sensors and liquid level sensors are arranged on the wastewater pretreatment thermostatic tanks.

[0012] It also includes an accident pool, which is connected to a wastewater homogenization regulating tank through a pipeline, and the wastewater homogenization regulating tank is connected to a wastewater pretreatment constant temperature tank through a reflux pipe. A temperature sensor and a liquid level sensor are arranged on the wastewater homogenization regulating tank.

[0013] A gas back-blowing bubbling system is provided in the wastewater collection tank to pass air into the wastewater to generate bubbles.

[0014] A wastewater collection open channel is arranged on the upper part of the wastewater collection pool, and a metal filter is arranged in the wastewater collection open channel.

[0015] There are two metal filters, which are arranged at intervals in the wastewater collection open channel. The metal filter includes a filter body and a filter frame. The filter body is arranged on the filter frame. A handle is arranged at the top of the filter frame, and a storage groove is arranged at the bottom of the filter frame. The opening of the storage groove is vertically upward, and the filter body is inclined, forming an obtuse angle with the bottom wall of the storage groove.

[0016] The utility model provides a PTA wastewater pretreatment device, which reasonably mixes condensate, process wastewater and PTA wastewater, and mixes them in a constant temperature tank and a homogenization adjustment tank, and finally achieves that the PTA wastewater entering the anaerobic system is within the required temperature range through heat exchange, so as to improve the stability of wastewater treatment, while having low energy consumption and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a structural schematic diagram of the metal filter screen of the utility model;

[0019] Figure 3 It is a cross-sectional schematic diagram of the metal filter screen of the present utility model;

[0020] Figure 4 It is a structural schematic diagram of a mixer on a wastewater main pipe of the utility model;

[0021] Figure 5 It is a schematic structural diagram of the mixing ejector of the utility model. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0023] Embodiment 1:

[0024] like Figure 1As shown, the utility model discloses a PTA wastewater pretreatment device, including a No. 1 condensate collection tank 1, a No. 2 condensate collection tank 2, a wastewater collection pool 7, a wastewater main pipe 12, a wastewater pretreatment constant temperature tank 13, a wastewater homogenization adjustment tank 17 and a heat exchanger 19, a condensate delivery pipe is arranged at the bottom of the No. 1 condensate collection tank 1 and the No. 2 condensate collection tank 2, a condensate delivery pump 4 is arranged on the condensate delivery pipe, and a condensate delivery control valve 5 is arranged after the condensate delivery pipes are merged, and connected to the wastewater main pipe 12, and an emptying collection pipe 101 is arranged at the top of the No. 1 condensate collection tank 1 and the No. 2 condensate collection tank 2, and the emptying collection pipe 101 is used to maintain the air pressure balance in the No. 1 condensate collection tank 1 and the No. 2 condensate collection tank 2. A condensate collection pipe 102 is arranged on the No. 1 condensate collection tank 1 and the No. 2 condensate collection tank 2, and the condensate collection pipe 102 is used to collect condensate generated during the production process of the PTA device. A liquid level sensor 3 is provided on the condensate delivery pipe, which is used to detect the condensate level in the corresponding No. 1 condensate collection tank 1 and No. 2 condensate collection tank 2. A process wastewater collection pipe 9 is connected to the wastewater main pipe 12, and a temperature sensor 91 is provided on the process wastewater collection pipe 9. The wastewater main pipe 12 extends into the wastewater collection tank 7. A filter screen 81 is provided on the wastewater main pipe 12 in the wastewater collection tank 7 to prevent impurities from entering the wastewater main pipe 12. A wastewater delivery pump 8, a filter 82, a pressure transmitter 83, a wastewater delivery control valve 10, and a mixer 11 are sequentially provided on the wastewater main pipe 12. The process wastewater collection pipe 9 and the condensate delivery pipe are connected to the wastewater main pipe 12 between the pressure transmitter 83 and the mixer 11. The wastewater main pipe 12 is connected to the wastewater pretreatment constant temperature tank 13. A mixing ejector 14 is provided on the wastewater main pipe 12 in the wastewater pretreatment constant temperature tank 13. The condensate, process wastewater and PTA wastewater in the wastewater pool are all transported to the wastewater main pipe 12 through the condensate delivery pump 5, the process wastewater collection pipe 9 and the wastewater delivery pump 8, enter the mixer 11 for mixing, and then are input into the wastewater pretreatment constant temperature tank 13 through the mixing ejector 14.

[0025] The wastewater pretreatment constant temperature tank 13 is connected to the wastewater homogenization adjustment tank 17 through a constant temperature wastewater delivery pipe, and a constant temperature wastewater delivery pump 16 is arranged on the constant temperature wastewater delivery pipe. The wastewater homogenization adjustment tank 17 is connected to the heat exchanger 19 through a homogenous wastewater delivery pipe, and a homogenous wastewater delivery pump 18 is arranged on the homogenous wastewater delivery pipe. The wastewater outlet end of the heat exchanger 19 is connected to the anaerobic system 24, and cooling water 22 and steam 20 inlet pipes are arranged on the heat exchanger 19, and cooling water and steam outlet pipes are arranged on the heat exchanger 19.

[0026] An electromagnetic flow meter and a flow control valve are arranged on the homogeneous wastewater conveying pipe.

[0027] A stainless steel cover 71 may be provided on the wastewater collection tank 7 .

[0028] The wastewater in the wastewater pretreatment constant temperature tank 13 is sent to the wastewater homogenization adjustment tank 17 through the constant temperature wastewater delivery pump 16, and then sent to the heat exchanger 19 after adjustment. The heat exchanger 19 adjusts the temperature according to the actual temperature of the constant temperature wastewater. It can use cooling water 22 for cooling, or steam 20 for heating. The steam is 4.7 Barg steam produced by the PTA device. The temperature-adjusted PTA wastewater is sent to the anaerobic system 24, so that the PTA wastewater reaches a suitable temperature range to adapt to the anaerobic system and improve the treatment effect and stability of the anaerobic system on wastewater.

[0029] There are two wastewater pretreatment thermostatic tanks 13, and the wastewater main pipe 12 is connected to the two wastewater pretreatment thermostatic tanks 13 respectively. A mixing ejector 14 is provided on the wastewater main pipe 12 in the wastewater pretreatment thermostatic tank 13, and a temperature sensor 131 and a liquid level sensor 132 are provided on the wastewater pretreatment thermostatic tank 13. The use of two wastewater pretreatment thermostatic tanks 13 in parallel can effectively increase the temporary storage capacity of wastewater to ensure the continuous and stable operation of the anaerobic system 24.

[0030] It also includes an accident pool 15, which is connected to a wastewater homogenization regulating tank 17 through a pipeline, and the wastewater homogenization regulating tank 17 is connected to the wastewater pretreatment constant temperature tank 13 through a reflux pipe, and a temperature sensor 173 and a liquid level sensor 172 are provided on the wastewater homogenization regulating tank 17. The accident pool 15 is used for buffer storage of planned and unplanned shutdown of production equipment and special operation drainage.

[0031] A gas back-blowing bubbling system 72 is provided in the wastewater collection tank 7 to pass air into the wastewater to generate bubbles. The gas back-blowing bubbling system 72 includes a main pipe and a plurality of branch pipes, and the branch pipes are distributed in the wastewater collection tank 7.

[0032] like Figure 2 As shown, a wastewater collection open channel 6 is arranged on the upper part of the wastewater collection pool 7, and a metal filter screen 61 is arranged in the wastewater collection open channel 6.

[0033] There are two metal filters 61, which are arranged at intervals in the wastewater collection open channel 6. The metal filter 61 includes a filter body 612 and a filter frame 611. The filter body 612 is arranged on the filter frame 611. A handle 614 is arranged at the top of the filter frame 611, and a receiving groove 613 is arranged at the bottom of the filter frame 611. The opening of the receiving groove 613 is vertically upward, and the filter body 612 is inclined, forming an obtuse angle with the bottom wall of the receiving groove 613.

[0034] The filter frame 611 of the metal filter 61 fits the side wall of the wastewater collection open channel 6, and the filter frame 611 can prevent the filter body 612 from being damaged. The filter body 612 is tilted in the wastewater collection open channel 6. Preferably, the filter body 612 and the bottom wall of the storage tank 613 form an angle of 120°, so that when impurities accumulate in the filter body 612, they will sink into the storage tank 613. After a certain period of time, the metal filter 61 can be lifted up to clean the impurities in the storage tank 613, which makes it more convenient to clean the impurities. The two metal filters 61 are arranged at intervals, and one of them is being cleaned while the other metal filter 61 can filter the impurities in the wastewater.

[0035] like Figure 3 As shown, the structure of the mixer 11 on the wastewater main pipe 12 includes a shell, which is provided with a condensate injection connection port 112, a process wastewater injection connection port 113, and a wastewater main pipe connection inlet and outlet 111, and the shell is provided with a cross-flow mixing internal 114. The specific structure of the cross-flow mixing internal 114 is not limited, and it is only used to mix the wastewater entering the shell.

[0036] like Figure 4 As shown, the structure of the mixing ejector 14 is: a wastewater inlet 142, a conical low-pressure zone 143, a mixing zone 141 and a diffusion outlet 144. It is an existing commercially available product, and the specific structure is not repeated. The mixing ejector 14 is installed at the end of the wastewater main pipe 12 entering the wastewater pretreatment thermostatic tank 13. There are 4 groups of pipelines entering the wastewater pretreatment thermostatic tank 13, which are evenly distributed around the wastewater pretreatment thermostatic tank 13 at intervals of 90°. The high-powered jet provided by the wastewater delivery pump 8 forms a low pressure in its conical inlet, thereby absorbing and driving a stream of liquid, accelerating it, and highly vortexing in the ejector, producing an internally mixed mixed liquid. At the diffusion outlet of the mixing ejector, this mixing speed is partially converted into pressure, so that the mixed liquid ejected from the ejector is diffused in a cone shape, and the liquid around it is driven to achieve sufficient stirring and mixing of the wastewater to maintain a constant temperature uniformity.

[0037] The condensate collection tank collects all the low-grade steam condensate, steam generator kettle condensate, flushing, heating condensate and other clean high-temperature wastewater in the device, and sends them to the wastewater main pipe 12 through the condensate delivery pump 4 together with other process wastewater generated in the production process of the device and wastewater in the wastewater collection pool through the control valve to control the flow rate. The wastewater main pipe 12 is equipped with a pressure transmitter 83, a mixer 11 on the wastewater main pipe 12, and a temperature sensor. The wastewater temperature is raised to a temperature above 42-43°C through three-stream water flow control and regulation, and is delivered to the wastewater pretreatment constant temperature tank 13. The wastewater pretreatment constant temperature tank 13 is equipped with a mixing ejector 14 and a temperature sensor 131. Through mixing and flipping, the water temperature is kept constant and evenly distributed. The wastewater is delivered to the wastewater homogenization adjustment tank 17 through the constant temperature wastewater delivery pump 16 at the bottom of the wastewater pretreatment constant temperature tank 13 to adjust the PH, COD and other indicators, and finally compensated by the heat exchanger to reach a suitable temperature and delivered to the anaerobic system 24 for biochemical treatment. The wastewater temperature entering the anaerobic system 24 is ensured to be uniform and constant at about 38°C, the heat of the wastewater of the device is fully recovered, and the steam consumption is saved by more than 85%.

[0038] In summary, the utility model can effectively prevent the wastewater pretreatment system and anaerobic system equipment and pipelines of the PTA device from being blocked, ensure the long-term stable operation of the wastewater pretreatment device, and can effectively recover the heat of condensate discharged from the PTA device, low-grade steam, flushing, heated condensed wastewater and high-temperature process wastewater, increase the temperature of the device pretreatment wastewater, improve the wastewater heating efficiency in spring, autumn and winter, save a lot of energy consumption, greatly reduce the cost of wastewater treatment, increase the amount of recycled water, and reduce the labor intensity of on-site technicians.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0040] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be an interactive relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simplified modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A PTA sewage pretreatment device, characterized in that: It includes a No. 1 condensate collection tank, a No. 2 condensate collection tank, a wastewater collection pool, a wastewater main pipe, a wastewater pretreatment constant temperature tank, a wastewater homogenization adjustment tank and a heat exchanger. Condensate delivery pipes are arranged at the bottom of the No. 1 condensate collection tank and the No. 2 condensate collection tank. Condensate delivery pumps are arranged on the condensate delivery pipes respectively. Condensate delivery control valves are arranged after the condensate delivery pipes are merged and connected to the wastewater main pipe. A process wastewater collection pipe is connected to the wastewater main pipe. A temperature sensor is arranged on the process wastewater collection pipe. The wastewater main pipe extends into the wastewater collection pool. A wastewater delivery pump, a filter, a pressure transmitter and a mixer are arranged on the wastewater main pipe in sequence. The process wastewater collection pipe , the condensate delivery pipe is connected to the wastewater main pipe between the pressure transmitter and the mixer, the wastewater main pipe is connected to the wastewater pretreatment constant temperature tank, a mixing ejector is arranged on the wastewater main pipe in the wastewater pretreatment constant temperature tank, the wastewater pretreatment constant temperature tank is connected to the wastewater homogenization adjustment tank through the constant temperature wastewater delivery pipe, a constant temperature wastewater delivery pump is arranged on the constant temperature wastewater delivery pipe, the wastewater homogenization adjustment tank is connected to the heat exchanger through the homogenous wastewater delivery pipe, a homogenous wastewater delivery pump is arranged on the homogenous wastewater delivery pipe, the wastewater outlet end of the heat exchanger is connected to the anaerobic system, cooling water and steam inlet pipes are arranged on the heat exchanger, and cooling water and steam outlet pipes are arranged on the heat exchanger.

2. A PTA sewage pretreatment device according to claim 1, characterized in that: There are two wastewater pretreatment thermostatic tanks, and the wastewater main pipes are connected to the two wastewater pretreatment thermostatic tanks respectively. Mixing ejectors are arranged on the wastewater main pipes in the wastewater pretreatment thermostatic tanks, and temperature sensors and liquid level sensors are arranged on the wastewater pretreatment thermostatic tanks.

3. A PTA sewage pretreatment device according to claim 1 or 2, characterized in that: It also includes an accident pool, which is connected to a wastewater homogenization regulating tank through a pipeline, and the wastewater homogenization regulating tank is connected to a wastewater pretreatment constant temperature tank through a reflux pipe. A temperature sensor and a liquid level sensor are arranged on the wastewater homogenization regulating tank.

4. A PTA sewage pretreatment device according to claim 3, characterized in that: A gas back-blowing bubbling system is provided in the wastewater collection tank to pass air into the wastewater to generate bubbles.

5. A PTA wastewater pretreatment device according to claim 1, characterized in that: A wastewater collection open channel is arranged on the upper part of the wastewater collection pool, and a metal filter is arranged in the wastewater collection open channel.

6. A PTA wastewater pretreatment device according to claim 5, characterized in that: There are two metal filters, which are arranged at intervals in the wastewater collection open channel. The metal filter includes a filter body and a filter frame. The filter body is arranged on the filter frame. A handle is arranged at the top of the filter frame, and a storage groove is arranged at the bottom of the filter frame. The opening of the storage groove is vertically upward, and the filter body is inclined, forming an obtuse angle with the bottom wall of the storage groove.

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