A waste heat recycling device for esterification wastewater

Abstract

The utility model discloses a kind of waste heat recycling devices of esterification wastewater, the water outlet of esterification wastewater tank is connected with the first end of first three-way pipe;First heat exchange device has the first wastewater flow channel and ethylene glycol flow channel of mutual heat exchange;The inlet end of first wastewater flow channel is connected with the second end of first three-way pipe, outlet end is connected with the second end of second three-way pipe;The inlet end of ethylene glycol flow channel is connected with ethylene glycol conveying pipeline, outlet end is connected with the inlet end of catalyst configuration tank;Second heat exchange device has the second wastewater flow channel and cooling water flow channel of mutual heat exchange;The inlet end of second wastewater flow channel is connected with the third end of second three-way pipe;The third end of first three-way pipe is connected with the first end of second three-way pipe.The utility model can make full use of waste heat contained in esterification wastewater to heat catalyst solution, effectively save the heat required when catalyst solution is configured.

Description

Technical Field

[0001] This utility model relates to the technical field of esterification wastewater treatment equipment, and in particular to a waste heat recovery device for esterification wastewater. Background Technology

[0002] Currently, in the polyester production process, wastewater and ethylene glycol mixed vapor generated during the esterification reaction are separated in a process tower based on their different boiling points. The separated water vapor is liquefied by cooling and then enters a wastewater collection tank. The wastewater in this collection tank is at a high temperature and contains a large amount of usable waste heat. Before entering the stripping tower in the furnace area, the wastewater needs to undergo heat exchange cooling, and the water temperature needs to be reduced to about 40°C to meet the temperature requirements for entering the stripping tower. This heat exchange process wastes a large amount of usable heat energy and increases cooling costs.

[0003] In the polycondensation reaction, the required catalyst solution is prepared by mixing ethylene glycol and antimony glycol at room temperature. It must be heated from room temperature to above 110°C before it can be used in the system. A large amount of heat energy needs to be absorbed during the heating process. Utility Model Content

[0004] To address the aforementioned technical problems, the purpose of this utility model is to propose a waste heat recovery device for esterification wastewater, which can fully utilize the waste heat contained in the esterification wastewater to heat the catalyst solution, effectively saving the heat required for catalyst solution preparation, and is highly practical.

[0005] The technical solution of this utility model is achieved as follows: a waste heat recovery device for esterification wastewater, comprising an esterification wastewater tank, a first heat exchange device, a second heat exchange device, a first three-way pipe, a second three-way pipe, and a catalyst preparation tank;

[0006] The outlet of the esterification wastewater tank is connected to the first end of the first tee pipe;

[0007] The first heat exchange device has a first wastewater flow channel and an ethylene glycol flow channel that exchange heat with each other; the inlet end of the first wastewater flow channel is connected to the second end of the first tee pipe, and the outlet end is connected to the second end of the second tee pipe; the inlet end of the ethylene glycol flow channel is connected to the ethylene glycol conveying pipeline, and the outlet end is connected to the inlet end of the catalyst preparation tank.

[0008] The second heat exchange device has a second wastewater flow channel and a cooling water flow channel that exchange heat with each other; the inlet end of the second wastewater flow channel is connected to the third end of the second tee pipe.

[0009] The third end of the first tee pipe is connected to the first end of the second tee pipe;

[0010] Each of the second end of the first tee pipe, the third end of the first tee pipe, and the second end of the second tee pipe is provided with a switch valve for controlling the independent opening and closing of that end.

[0011] Furthermore, the first heat exchange device includes a tank, a delivery pipe, and a return pipe;

[0012] The tank has a heat exchange chamber and inlet / outlet chambers and reflux chambers independently arranged at both ends of the heat exchange chamber; the inlet / outlet chambers are divided into an independent inlet chamber and an outlet chamber; the tank has a first connecting port and a second connecting port communicating with the heat exchange chamber; the first wastewater flow channel is formed inside the tank between the first connecting port and the second connecting port; and the tank has a third connecting port communicating with the inlet chamber and a fourth connecting port communicating with the outlet chamber.

[0013] Several sets of the conveying pipes are arranged side by side in the heat exchange chamber, and each has a first end extending into the inlet chamber and a second end extending into the reflux chamber.

[0014] Several sets of the reflux pipes are arranged side by side in the heat exchange chamber, each having a first end extending to the outlet chamber and a second end extending to the reflux chamber.

[0015] The ethylene glycol flow channel is formed between the inlet cavity, the delivery pipe, the return cavity, the return pipe, and the outlet cavity.

[0016] Furthermore, the first and second connecting ports are located on opposite sides of the tank along its length.

[0017] Furthermore, a plurality of baffles are arranged at intervals between the first and second connecting ports within the heat exchange chamber; a flow gap is formed between the baffles and the inner wall of the tank; the projections of any two baffles along the length of the tank have an overlapping portion.

[0018] Furthermore, the second heat exchange device is a plate heat exchanger.

[0019] Furthermore, the outlet end of the second wastewater channel is connected to the stripping tower in the furnace area.

[0020] Furthermore, a first thermometer for detecting the wastewater temperature is installed on the pipeline between the outlet end of the first wastewater channel and the second end of the second tee pipe.

[0021] Furthermore, a second thermometer for detecting the temperature of ethylene glycol is provided on the pipeline between the outlet end of the ethylene glycol flow channel and the inlet end of the catalyst preparation tank.

[0022] Furthermore, each of the first end of the first tee pipe, the second end of the second tee pipe, and the third end of the second tee pipe is provided with a switch valve for controlling the independent opening and closing of that end.

[0023] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0024] 1. This utility model, through the use of a first heat exchange device, allows esterification wastewater to be transported via a first wastewater channel and ethylene glycol via an ethylene glycol channel, enabling heat exchange between the esterification wastewater and room-temperature ethylene glycol. The heat-exchanged ethylene glycol then enters a catalyst preparation tank to prepare a catalyst solution. By using a first three-way pipe and a second three-way pipe in combination, the flow of esterification wastewater into either the first or second heat exchange device can be selectively controlled. This combination fully utilizes the waste heat contained in the esterification wastewater to heat the catalyst solution, effectively saving the heat required for catalyst solution preparation. Furthermore, the heat exchange method can be selected according to actual production and processing needs, making it highly practical.

[0025] 2. By using the first heat exchange device in conjunction with the baffle inside the tank, the turbulence of the esterification wastewater flowing in the tank can be increased through the obstruction of the baffle, so that the ethylene glycol in the ethylene glycol channel can fully exchange heat with the esterification wastewater, effectively improving the heat exchange effect. Attached Figure Description

[0026] The technical solution of this utility model will be further described below with reference to the accompanying drawings:

[0027] Figure 1 This is a flowchart of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the first heat exchange device of this utility model;

[0029] Figure 3 This is a layout diagram of the delivery pipe and return pipe of this utility model;

[0030] The components include: 1. Esterification wastewater tank; 2. First heat exchanger; 21. Tank body; 22. Heat exchange chamber; 221. Conveying pipe; 222. Return pipe; 23. Inlet / outlet chamber; 231. Inlet chamber; 232. Outlet chamber; 24. Return chamber; 25. First connecting port; 26. Second connecting port; 27. Third connecting port; 28. Fourth connecting port; 29. ​​Baffle; 3. Second heat exchanger; 4. First tee pipe; 5. Second tee pipe; 6. Switch valve; 7. Ethylene glycol conveying pipeline; 71. First thermometer; 72. Second thermometer; 8. Furnace stripping tower; 9. Catalyst preparation tank. Detailed Implementation

[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0032] like Figure 1-3 The diagram shows a waste heat recovery device for esterification wastewater according to this embodiment. The waste heat recovery device includes an esterification wastewater tank 1, a first heat exchanger 2, a second heat exchanger 3, a first three-way pipe 4, a second three-way pipe 5, and a catalyst preparation tank 9. The esterification wastewater tank 1 is used to store the esterification wastewater after separation in the process tower.

[0033] The aforementioned first tee pipe 4 and second tee pipe 5 are conventional components of the prior art, both having three interconnected channels. The first tee pipe 4 and second tee pipe 5 can be T-shaped or Y-shaped.

[0034] The aforementioned first heat exchange device 2 has a first wastewater channel and an ethylene glycol channel for mutual heat exchange. The first wastewater channel is used to transport esterification wastewater, while the ethylene glycol channel is used to transport ethylene glycol. During the transport process, the aforementioned esterification wastewater and ethylene glycol can exchange heat through the first heat exchange device 2.

[0035] The aforementioned second heat exchange device 3 has a second wastewater channel and a cooling water channel that exchange heat with each other. The second wastewater channel is used to transport esterification wastewater, while the cooling water channel is used to transport cooling water. During the transport process, the esterification wastewater and cooling water can exchange heat through the second heat exchange device 3.

[0036] In the specific pipeline layout, the outlet of the esterification wastewater tank 1 is connected to the first end of the first tee pipe 4 via a pipeline. The inlet of the first wastewater channel is connected to the second end of the first tee pipe 4 via a pipeline, and the outlet is connected to the second end of the second tee pipe 5 via a pipeline. The inlet of the ethylene glycol channel is connected to the ethylene glycol delivery pipeline 7 via a pipeline, and the outlet is connected to the inlet of the catalyst preparation tank 9 via a pipeline. The inlet of the second wastewater channel is connected to the third end of the second tee pipe 5 via a pipeline. The third end of the first tee pipe 4 is connected to the first end of the second tee pipe 5 via a pipeline. A switch valve 6 is installed at each of the second ends of the first tee pipe 4, the third end of the first tee pipe 4, and the second end of the second tee pipe 5 to control the independent opening and closing of that end. This switch valve 6 is designed for manual or automatic operation. The installation position of the switch valve 6 is determined according to actual needs.

[0037] Each of the first end of the first three-way pipe 4, the second end of the second three-way pipe 5, and the third end of the second three-way pipe 5 is equipped with a switch valve 6 for controlling the independent opening and closing of that end.

[0038] In this embodiment, the aforementioned first heat exchange device 2 includes a tank 21, a delivery pipe 221, and a return pipe 222. The tank 21 has a heat exchange chamber 22, and inlet / outlet chambers 23 and a return chamber 24, which are independently arranged at both ends of the heat exchange chamber 22. The heat exchange chamber 22, inlet / outlet chamber 23, and return chamber 24 are all closed chamber structures. The heat exchange chamber 22 extends along the length of the tank 21. The inlet / outlet chamber 23 is divided into an inlet chamber 231 and an outlet chamber 232 by a partition. The tank 21 has a first connecting port 25 communicating with the heat exchange chamber 22 and a second connecting port 26 communicating with the heat exchange chamber 22. A first wastewater flow channel is formed inside the tank 21 between the first connecting port 25 and the second connecting port 26. The first connecting port 25 and the second connecting port 26 are located on both sides of the tank 21 along its length to extend the path of the first wastewater flow channel. The tank body 21 is provided with a third connecting port 27 communicating with the inlet chamber 231 and a fourth connecting port 28 communicating with the outlet chamber 232. Several sets of the aforementioned conveying pipes 221 are arranged side-by-side in the heat exchange chamber 22. Each conveying pipe 221 extends along the length of the tank body 21 and has a first end extending to the inlet chamber 231 and a second end extending to the reflux chamber 24, so that the reflux chamber 24 and the inlet chamber 231 are connected via the conveying pipes 221. Several sets of the aforementioned reflux pipes 222 are arranged side-by-side in the heat exchange chamber 22, each having a first end extending to the outlet chamber 232 and a second end extending to the reflux chamber 24, so that the reflux chamber 24 and the outlet chamber 232 are connected via the reflux pipes 222. Through the above structural design, an ethylene glycol flow channel is formed between the aforementioned inlet chamber 231, delivery pipe 221, return chamber 24, return pipe 222, and outlet chamber 232, which can increase the length of the ethylene glycol flow channel in the tank 21 and increase the delivery time of ethylene glycol in the tank 21, thereby improving the heat exchange effect.

[0039] In this embodiment, a plurality of baffles 29 are arranged at intervals between the first connecting port 25 and the second connecting port 26 within the heat exchange chamber 22. A flow gap is formed between each baffle 29 and the inner wall of the tank 21. Esterification wastewater can pass through this flow gap. The projections of any two baffles 29 along the length of the tank 21 overlap. The baffles 29 are arranged in an alternating pattern. Through this structural design, the turbulence of the esterification wastewater flowing within the tank 21 is increased due to the obstruction of the baffles 29, allowing the ethylene glycol in the ethylene glycol channel to fully exchange heat with the esterification wastewater, effectively improving the heat exchange effect.

[0040] The aforementioned second heat exchange device 3 is preferably a plate heat exchanger, a conventional device in the prior art. The plate heat exchanger is a conventional device in the prior art, and its specific heat exchange principle and effect are also existing technologies. The outlet end of the aforementioned second wastewater channel is connected to the stripping tower 8 in the furnace area. The inlet end of the aforementioned cooling water channel is connected to a water supply device to supply cooling water to the cooling water channel, and the outlet end of the cooling water channel can be connected to a water storage tank.

[0041] In this embodiment, a first thermometer 71 for detecting the wastewater temperature is installed on the pipeline between the outlet end of the first wastewater channel and the second end of the second tee pipe 5. A second thermometer 72 for detecting the ethylene glycol temperature is installed on the pipeline between the outlet end of the ethylene glycol channel and the inlet end of the catalyst preparation tank 9. Both the first thermometer 71 and the second thermometer 72 are sheathed thermometers.

[0042] In practical use, when the switch valve 6 at the second end of the first three-way pipe 4 is closed (other switch valves 6 are switched on and off according to operational requirements), the esterification wastewater is transported from the esterification wastewater tank 1 to the first heat exchange device 2, then through the first wastewater channel to the second heat exchange device 3, and finally through the second wastewater channel to the furnace stripping tower 8. Meanwhile, room-temperature ethylene glycol is transported through the ethylene glycol pipeline to the first heat exchange device 2, and after heat exchange in the ethylene glycol channel, it is transported to the catalyst preparation tank 9. Cooling water is also selectively supplied to the cooling water channel based on the temperature of the esterification wastewater. During this process, the esterification wastewater undergoes heat exchange and cooling in the first heat exchange device 2 and the second heat exchange device 3 to meet the temperature requirements for entering the furnace stripping tower 8. When the valve 6 at the second end of the first three-way pipe 4 is opened and the valve 6 at the third end of the first three-way pipe 4 is closed (other valves 6 are switched on and off according to operational requirements), the esterification wastewater is transported from the esterification wastewater tank 1 to the second heat exchange device 3, and then to the furnace stripping tower 8 via the second wastewater channel. Cooling water is transported into the cooling water channel to exchange heat with the esterification wastewater. In the above method, the esterification wastewater can be transported via the first wastewater channel and ethylene glycol via the ethylene glycol channel to exchange heat between the esterification wastewater and room-temperature ethylene glycol. The heat-exchanged ethylene glycol enters the catalyst preparation tank 9 to prepare a catalyst solution. By using the first three-way pipe 4 and the second three-way pipe 5 in combination, the esterification wastewater can be selectively controlled to enter the first heat exchange device 2 or the second heat exchange device 3 for heat exchange. The combination of the above methods can make full use of the waste heat contained in the esterification wastewater to heat the catalyst solution, effectively saving the heat required for catalyst solution preparation, and the heat exchange method can be selected according to the actual production and processing requirements, making it highly practical.

[0043] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A waste heat recovery device for esterification wastewater, comprising an esterification wastewater tank, a first heat exchanger, a second heat exchanger, a first three-way pipe, a second three-way pipe, and a catalyst preparation tank; characterized in that: The outlet of the esterification wastewater tank is connected to the first end of the first tee pipe; The first heat exchange device has a first wastewater flow channel and an ethylene glycol flow channel that exchange heat with each other; the inlet end of the first wastewater flow channel is connected to the second end of the first tee pipe, and the outlet end is connected to the second end of the second tee pipe; the inlet end of the ethylene glycol flow channel is connected to the ethylene glycol conveying pipeline, and the outlet end is connected to the inlet end of the catalyst preparation tank. The second heat exchange device has a second wastewater flow channel and a cooling water flow channel that exchange heat with each other; the inlet end of the second wastewater flow channel is connected to the third end of the second tee pipe. The third end of the first tee pipe is connected to the first end of the second tee pipe; Each of the second end of the first tee pipe, the third end of the first tee pipe, and the second end of the second tee pipe is provided with a switch valve for controlling the independent opening and closing of that end.

2. The waste heat recovery device for esterification wastewater according to claim 1, characterized in that: The first heat exchange device includes a tank, a delivery pipe, and a return pipe; The tank has a heat exchange chamber and inlet / outlet chambers and reflux chambers independently arranged at both ends of the heat exchange chamber; the inlet / outlet chambers are divided into an independent inlet chamber and an outlet chamber; the tank has a first connecting port and a second connecting port communicating with the heat exchange chamber; the first wastewater flow channel is formed inside the tank between the first connecting port and the second connecting port; and the tank has a third connecting port communicating with the inlet chamber and a fourth connecting port communicating with the outlet chamber. Several sets of the conveying pipes are arranged side by side in the heat exchange chamber, and each has a first end extending into the inlet chamber and a second end extending into the reflux chamber. Several sets of the reflux pipes are arranged side by side in the heat exchange chamber, each having a first end extending to the outlet chamber and a second end extending to the reflux chamber. The ethylene glycol flow channel is formed between the inlet cavity, the delivery pipe, the return cavity, the return pipe, and the outlet cavity.

3. The waste heat recovery device for esterification wastewater according to claim 2, characterized in that: The first and second connecting ports are located on opposite sides of the length of the tank.

4. The waste heat recovery device for esterification wastewater according to claim 3, characterized in that: Several baffles are arranged at intervals between the first and second connecting ports in the heat exchange chamber; a flow gap is formed between the baffles and the inner wall of the tank; the projections of any two baffles in the length direction of the tank have an overlapping portion.

5. The waste heat reutilization device for esterification wastewater according to claim 1, characterized in that: The second heat exchange device is a plate heat exchanger.

6. The waste heat reutilization device for esterification wastewater according to claim 1, characterized in that: The outlet end of the second wastewater channel is connected to the stripping tower in the furnace area.

7. The waste heat recovery device for esterification wastewater according to claim 1, characterized in that: A first thermometer for detecting wastewater temperature is installed on the pipeline between the outlet end of the first wastewater flow channel and the second end of the second tee pipe.

8. The waste heat reutilization device for esterification wastewater according to claim 1, characterized in that: A second thermometer for detecting the temperature of ethylene glycol is installed on the pipeline between the outlet end of the ethylene glycol flow channel and the inlet end of the catalyst preparation tank.

9. The waste heat recovery device for esterification wastewater according to claim 1, characterized in that: Each of the first end of the first tee pipe, the second end of the second tee pipe, and the third end of the second tee pipe is provided with a switch valve for controlling the independent opening and closing of that end.

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