Device and method for co-preheating of flue gas washing wastewater and leachate

Abstract

The present invention provides a device and method for preheating tobacco-washing wastewater and leachate in a coordinated manner, comprising a heat exchange device, a steam mixing device and a control device; the heat exchange device comprises a first heat exchanger and a second heat exchanger; a leachate pipeline is connected to the refrigerant inlet of the first heat exchanger, a heat medium inlet is connected to the tobacco-washing wastewater pipeline through the first pipeline, and a refrigerant outlet is connected to the steam mixing device through the second pipeline; the second heat exchanger is connected to the tobacco-washing wastewater pipeline through the third pipeline; a steam delivery pipeline is arranged at the steam outlet of the steam mixing device; a branch pipeline is arranged between the second pipeline and the steam delivery pipeline; the control device comprises a temperature detection and control device, a first valve, a second valve, a third valve and a fourth valve respectively interlocked with the signal of the temperature detection and control device. The present invention can solve the problems that the heat of high-temperature tobacco-washing wastewater in the existing technology cannot be effectively utilized, but a large amount of circulating water is required for cooling treatment, resulting in energy waste.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and more specifically, to a device and method for collaboratively preheating cigarette washing wastewater and leachate. Background Art

[0002] With the increasing environmental protection standards, when building waste incineration plants, when the traditional dry, semi-dry and combined flue gas treatment processes cannot fully meet the higher emission standards, the flue gas wet deacidification process can meet the increasingly stringent environmental standards. The flue gas wet deacidification process is the inevitable trend and mainstream process for flue gas purification in waste incineration power generation projects. After the bag filter and before the SCR denitrification system, a wet deacidification process is set up to further remove acidic pollutants in the flue gas. The wet deacidification process adopts a scrubbing tower. After the flue gas enters the scrubbing tower, it is fully contacted with the alkaline solution to obtain an efficient deacidification effect.

[0003] The scrubber consists of two parts, the lower part is the spray scrubbing process, and the upper part is the dehumidification process. In the scrubber process, the spray scrubbing liquid is a caustic soda (NaOH) solution. In the reaction process, the caustic soda reacts with hydrogen chloride, sulfur dioxide, etc. to generate salt. The scrubbing liquid is recycled before reaching the set salt concentration. When the scrubbing liquid reaches a certain salt concentration, a part of the scrubbing liquid should be discharged and a new caustic soda solution should be added. The wastewater discharged at this stage is called tobacco washing wastewater. The discharge of wastewater is mainly based on the salt content index of the scrubbing liquid as a reference. When designing, it is usually discharged at a salt content of 3%, and there are also cases where the salt content is controlled at 5-6%.

[0004] The outlet temperature of tobacco washing wastewater is around 75℃~80℃, and the tobacco washing wastewater treatment process requires the wastewater temperature to drop below 35℃, so a pretreatment process is required for cooling. The current pretreatment process requires circulating water heat exchange to cool the tobacco washing wastewater. As high-temperature wastewater, the heat of tobacco washing wastewater cannot be effectively utilized, but requires a large amount of circulating water for cooling, resulting in energy waste. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a device and method for co-heating tobacco washing wastewater and leachate, so as to solve the problem that tobacco washing wastewater is high-temperature wastewater in the prior art, its heat cannot be effectively utilized, but requires a large amount of circulating water for cooling treatment, resulting in energy waste.

[0006] The present invention provides a device for collaborative preheating of tobacco washing wastewater and leachate, comprising a heat exchange device, a steam mixing device and a control device; wherein the heat exchange device comprises a first heat exchanger and a second heat exchanger; a leachate pipeline is connected to the refrigerant inlet of the first heat exchanger, the heat medium inlet of the first heat exchanger is connected to the tobacco washing wastewater pipeline through a first pipeline, and the refrigerant outlet of the first heat exchanger is connected to the steam mixing device through a second pipeline; the second heat exchanger is connected to the tobacco washing wastewater pipeline through a third pipeline; a steam delivery pipeline is arranged at the steam outlet of the steam mixing device; a branch pipeline is arranged between the second pipeline and the steam delivery pipeline; the control device comprises a temperature detection and control device arranged on the second pipeline, a first valve arranged on the first pipeline and interlocked with the signal of the temperature detection and control device, a second valve arranged at the inlet of the steam mixing device, a third valve arranged on the third pipeline and a fourth valve arranged on the branch pipeline.

[0007] In addition, a preferred solution is that the first heat exchanger is a plate heat exchanger; and / or the second heat exchanger is a plate heat exchanger.

[0008] In addition, a preferred solution is to further include a tobacco washing wastewater regulating tank; the tobacco washing wastewater regulating tank is connected to the heat medium outlets of the first heat exchanger and the second heat exchanger respectively.

[0009] In addition, a preferred solution is that the steam mixing device includes a steam mixer; and the steam mixer is connected to the anaerobic reactor via the steam conveying pipeline.

[0010] In addition, a preferred solution is that the temperature detection and control device includes a temperature detection instrument and a control unit connected to the temperature detection instrument, and the control unit is electrically connected to the first valve, the second valve, the third valve and the fourth valve respectively.

[0011] In addition, a preferred solution is that the first valve, the second valve, the third valve and the fourth valve are all electromagnetic valves.

[0012] In addition, a preferred solution is that the control unit includes a single chip microcomputer.

[0013] The present invention also provides a method for collaboratively preheating tobacco washing wastewater and leachate, which uses the above-mentioned collaborative preheating device for tobacco washing wastewater and leachate to collaboratively preheat tobacco washing wastewater and leachate, comprising the following steps:

[0014] Open the first valve and close the third valve, so that the leachate and the tobacco washing wastewater enter the first heat exchanger for heat exchange, and the leachate after heat exchange in the first heat exchanger enters the second pipeline;

[0015] The temperature of the leachate in the second pipeline is detected by the temperature detection and control device to obtain a detected temperature;

[0016] When the detected temperature is lower than the preset temperature, the fourth valve is closed, and the second valve is opened, so that the leachate in the second pipeline enters the steam mixing device, and the leachate is kept warm and heated by the steam mixing device until the leachate reaches the preset temperature, and then is transported through the steam transport pipeline;

[0017] When the detected temperature is equal to the preset temperature, the fourth valve is opened, and the second valve is closed, so that the leachate in the second pipeline is transported to the steam delivery pipeline through the branch pipeline, and then transported by the steam delivery pipeline;

[0018] When the detected temperature is higher than the preset temperature, the first valve is closed, the third valve is opened, and the flow of the tobacco washing waste water in the first heat exchanger is adjusted to cool the leachate entering the first heat exchanger. The cooled leachate enters the second pipeline, and the fourth valve and the second valve are controlled based on the comparison between the detected temperature of the leachate in the second pipeline and the preset temperature.

[0019] In addition, a preferred solution is that the preset temperature is 35°C-40°C.

[0020] It can be seen from the above technical scheme that the device and method for collaborative preheating of tobacco washing wastewater and leachate provided by the present invention, through the first heat exchanger, the refrigerant inlet of the first heat exchanger is connected to the leachate pipeline, the hot medium inlet of the first heat exchanger is connected to the tobacco washing wastewater pipeline through the first pipeline, and the refrigerant outlet of the first heat exchanger is connected to the steam mixing device through the second pipeline, and the high heat of the tobacco washing wastewater is used to exchange heat with the leachate anaerobic system inlet water, so as to make full use of the high heat of the tobacco washing wastewater, avoid waste of resources, and save cooling water resources; through the second heat exchanger, the second heat exchanger is connected to the tobacco washing wastewater pipeline through the third pipeline, when the leachate temperature is too high and no heat exchange is needed, the tobacco washing wastewater in the tobacco washing wastewater pipeline can be treated in time, and the heat exchange can be automatically adjusted according to the leachate anaerobic system inlet temperature through the control device, which is convenient for control and improves work efficiency.

[0021] In order to achieve the above and related purposes, one or more aspects of the present invention include the features that will be described in detail later. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more clear and easy to understand. In the accompanying drawings:

[0023] Figure 1 2 is a schematic diagram of the structure of a device for coordinating preheating of tobacco washing wastewater and leachate according to an embodiment of the present invention;

[0024] Figure 2 The present invention is a flow chart of a method for co-heating tobacco washing wastewater and leachate according to an embodiment of the present invention.

[0025] In the attached drawings, 11-first heat exchanger, 12-second heat exchanger, 2-leachate pipeline, 31-first pipeline, 32-second pipeline, 33-third pipeline, 4-tobacco washing wastewater pipeline, 5-steam mixing device, 51-steam delivery pipeline, 6-branch pipeline, 71-temperature detection and control device, 72-first valve, 73-second valve, 74-third valve, 75-fourth valve, 8-tobacco washing wastewater regulating tank, 9-anaerobic reactor.

[0026] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0027] In the following description, for the purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. However, it is apparent that these embodiments may also be implemented without these specific details.

[0028] In response to the above-mentioned problem that in the prior art, tobacco washing wastewater is high-temperature wastewater and its heat cannot be effectively utilized. Instead, a large amount of circulating water is required for cooling, resulting in energy waste. A device and method for collaborative preheating of tobacco washing wastewater and leachate are proposed.

[0029] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] In order to illustrate the tobacco washing wastewater and leachate coordinated preheating device provided by the present invention, Figure 1 The structure of the device for co-heating tobacco washing wastewater and leachate according to an embodiment of the present invention is shown.

[0031] like Figure 1As shown, the tobacco washing wastewater and leachate coordinated preheating device provided by the present invention comprises a heat exchange device, a steam mixing device and a control device; wherein the heat exchange device comprises a first heat exchanger 11 and a second heat exchanger 12; a leachate pipeline 2 is connected to the refrigerant inlet of the first heat exchanger 11, the heat medium inlet of the first heat exchanger 11 is connected to the tobacco washing wastewater pipeline 4 through a first pipeline 31, and the refrigerant outlet of the first heat exchanger 11 is connected to the steam mixing device 5 through a second pipeline 32; the second heat exchanger 12 is connected to the tobacco washing wastewater through a third pipeline 33. The steam mixing device 5 is connected to the steam conveying pipeline 4; a steam conveying pipeline 51 is arranged at the steam outlet of the steam mixing device 5; a branch pipeline 6 is arranged between the second pipeline 32 and the steam conveying pipeline 51; the control device includes a temperature detection and control device 71 arranged on the second pipeline 32, a first valve 72 arranged on the first pipeline 31 and interlocked with the signal of the temperature detection and control device 71, a second valve 73 arranged at the inlet of the steam mixing device 5, a third valve 74 arranged on the third pipeline 33 and a fourth valve 75 arranged on the branch pipeline 6.

[0032] Through the first heat exchanger 11, the refrigerant inlet of the first heat exchanger 11 is connected to the leachate pipeline 2, the hot medium inlet of the first heat exchanger 11 is connected to the tobacco washing wastewater pipeline 4 through the first pipeline 31, and the refrigerant outlet of the first heat exchanger 11 is connected to the steam mixing device 5 through the second pipeline 32, so that the high heat of the tobacco washing wastewater is used to exchange heat with the leachate anaerobic system inlet water, so as to make full use of the high heat of the tobacco washing wastewater, avoid waste of resources, and save cooling water resources; through the second heat exchanger 12, the second heat exchanger 12 is connected to the tobacco washing wastewater pipeline 4 through the third pipeline 31, when the leachate temperature is too high and no heat exchange is needed, the tobacco washing wastewater in the tobacco washing wastewater pipeline can be treated in time, and the heat exchange can be automatically adjusted according to the leachate anaerobic system inlet water temperature through the control device, so as to facilitate control and improve work efficiency.

[0033] As a preferred embodiment of the present invention, the first heat exchanger 11 is a plate heat exchanger; and / or, the second heat exchanger 12 is a plate heat exchanger. The plate heat exchanger is one of the commonly used heat exchangers, and has the advantages of high heat transfer coefficient, large adaptability, compact structure, small volume, etc. Of course, other types of heat exchangers can also be used, as long as they can perform heat exchange between two liquids with a temperature difference, and are not particularly limited here.

[0034] As a preferred embodiment of the present invention, a wastewater regulating tank 8 is further included; the wastewater regulating tank 8 is respectively connected to the heat medium outlets of the first heat exchanger 11 and the second heat exchanger 12. The wastewater after heat exchange is regulated by the wastewater regulating tank 8 to facilitate subsequent discharge.

[0035] As a preferred embodiment of the present invention, the steam mixing device 5 includes a steam mixer; the steam mixer is connected to the anaerobic reactor 9 through a steam delivery pipeline 51. When the leachate after heat exchange in the first heat exchanger 11 does not reach the required temperature, the leachate is further heated by the steam mixing device 5 to ensure the smooth progress of the anaerobic process.

[0036] As a preferred solution of the present invention, the temperature detection and control device 71 includes a temperature detection instrument and a control unit connected to the temperature detection instrument, and the control unit is electrically connected to the first valve 72, the second valve 73, the third valve 74 and the fourth valve 75. The temperature of the leachate in the second pipeline 32 is detected by the temperature detection instrument, and the detected temperature is sent to the control unit, and the control unit compares the detected temperature with the preset temperature, thereby controlling the opening and closing of the first valve 72, the second valve 73, the third valve 74 and the fourth valve 75, and adjusting the temperature of the leachate entering the steam delivery pipeline 51.

[0037] As a preferred solution of the present invention, the first valve 72, the second valve 73, the third valve 74 and the fourth valve 75 are all electromagnetic valves. Electromagnetic doors are easy to control by signals.

[0038] As a preferred solution of the present invention, the control unit includes a single chip microcomputer. A single chip microcomputer is an integrated circuit chip that uses ultra-large-scale integrated circuit technology to integrate a central processing unit CPU with data processing capabilities, a random access memory RAM, a read-only memory ROM, multiple I / O ports and an interrupt system, a timer / counter and other functions. The single chip microcomputer can compare and analyze the detected temperature with the preset temperature, and then control each valve according to the comparison and analysis results.

[0039] Figure 2 The flowchart of the method for collaboratively preheating tobacco washing wastewater and leachate according to an embodiment of the present invention is shown.

[0040] like Figure 2 As shown, the method for collaborative preheating of tobacco washing wastewater and leachate provided by the present invention utilizes the collaborative preheating device for tobacco washing wastewater and leachate as described above to perform collaborative preheating treatment on tobacco washing wastewater and leachate, comprising the following steps:

[0041] S1, open the first valve 72, close the third valve 74, so that the leachate and the tobacco washing wastewater enter the first heat exchanger 11 for heat exchange, and the leachate after heat exchange in the first heat exchanger 11 enters the second pipeline 32;

[0042] S2, detecting the temperature of the leachate in the second pipeline 32 by the temperature detection and control device 71 to obtain the detected temperature;

[0043] S3, when the detected temperature is lower than the preset temperature, the fourth valve 75 is closed, and the second valve 73 is opened, so that the leachate in the second pipeline 32 enters the steam mixing device 5, and the leachate is kept warm and heated by the steam mixing device 5, and after the leachate reaches the preset temperature, it is transported through the steam transport pipeline 51;

[0044] S4, when the detected temperature is equal to the preset temperature, the fourth valve 75 is opened, and the second valve 73 is closed, so that the leachate in the second pipeline 32 is transported to the steam delivery pipeline 51 through the branch pipeline 6, and then transported by the steam delivery pipeline 51;

[0045] S5. When the detected temperature is higher than the preset temperature, the first valve 72 is closed, and the third valve 74 is opened to adjust the flow of the tobacco washing wastewater in the first heat exchanger 11 so that the leachate entering the first heat exchanger 11 is cooled down. The cooled leachate enters the second pipeline 32, and the fourth valve 75 and the second valve 73 are controlled based on the comparison between the detected temperature of the leachate in the second pipeline 32 and the preset temperature.

[0046] By opening the first valve 72 and closing the third valve 74, the high-temperature tobacco washing wastewater enters the first heat exchanger 11 from the heat medium inlet of the first heat exchanger 11, and exchanges heat with the leachate entering from the refrigerant inlet of the first heat exchanger 11. The leachate after heat exchange flows out from the refrigerant outlet of the first heat exchanger 11 and enters the second pipeline 32. The tobacco washing wastewater after heat exchange flows out from the heat medium outlet of the first heat exchanger 11 and enters the tobacco washing wastewater regulating tank 8, and is discharged after wastewater regulation treatment. In the above manner, the high heat of the tobacco washing wastewater is used to exchange heat with the water inlet of the leachate anaerobic system, so as to make full use of the high heat of the tobacco washing wastewater, avoid resource waste, and save cooling water resources.

[0047] The temperature of the leachate in the second pipeline 32 is detected by the temperature detection device 71. The temperature detection instrument detects the temperature of the leachate in the second pipeline 32, and sends the detected temperature to the control unit. The control unit compares the detected temperature with the preset temperature. When the detected temperature is lower than the preset temperature, the fourth valve 75 is closed and the second valve 73 is opened to allow the leachate in the second pipeline 32 to enter the steam mixing device 5. The leachate is kept warm and heated by the steam mixing device 5. After the leachate reaches the preset temperature, it is transported through the steam transport pipeline 51 to the anaerobic reactor 9 for anaerobic process.

[0048] When the detected temperature is equal to the preset temperature, the fourth valve 75 is opened and the second valve 73 is closed, so that the leachate in the second pipeline 32 is transported to the steam delivery pipeline 51 through the branch pipeline 6, and then transported by the steam delivery pipeline 51 to the anaerobic reactor 9 for anaerobic process;

[0049] When the detected temperature is higher than the preset temperature, the first valve 72 is closed and the third valve 74 is opened to adjust the flow of the tobacco washing wastewater in the first heat exchanger 11 so that the leachate entering the first heat exchanger 11 is cooled down, and the cooled leachate enters the second pipeline 32. The fourth valve 75 and the second valve 73 are controlled in the above manner based on the comparison between the detected temperature of the leachate in the second pipeline 32 and the preset temperature, and the tobacco washing wastewater enters the second heat exchanger 12 for heat exchange treatment, and after heat exchange, enters the tobacco washing wastewater regulating tank 8 for wastewater regulation treatment and then discharge.

[0050] As a preferred solution of the present invention, the preset temperature is 35° C.-40° C., which is conducive to the smooth progress of the anaerobic process.

[0051] It can be seen from the above specific embodiments that the device and method for collaborative preheating of tobacco washing wastewater and leachate provided by the present invention, through the first heat exchanger, the refrigerant inlet of the first heat exchanger is connected to the leachate pipeline, the hot medium inlet of the first heat exchanger is connected to the tobacco washing wastewater pipeline through the first pipeline, and the refrigerant outlet of the first heat exchanger is connected to the steam mixing device through the second pipeline, and the high heat of the tobacco washing wastewater is used to exchange heat with the inlet water of the leachate anaerobic system, so as to make full use of the high heat of the tobacco washing wastewater, avoid waste of resources, and save cooling water resources; through the second heat exchanger, the second heat exchanger is connected to the tobacco washing wastewater pipeline through the third pipeline, when the leachate temperature is too high and no heat exchange is needed, the tobacco washing wastewater in the tobacco washing wastewater pipeline can be treated in time, and the heat exchange can be automatically adjusted according to the inlet water temperature of the leachate anaerobic system through the control device, which is convenient for control and improves work efficiency.

[0052] As described above, the device and method for co-heating tobacco washing wastewater and leachate according to the present invention are described by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various improvements can be made to the device and method for co-heating tobacco washing wastewater and leachate according to the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A device for preheating tobacco washing wastewater and leachate, characterized in that: It includes a heat exchange device, a steam mixing device and a control device; wherein, The heat exchange device comprises a first heat exchanger and a second heat exchanger; A leachate pipeline is connected to the refrigerant inlet of the first heat exchanger, the heat medium inlet of the first heat exchanger is connected to the tobacco washing wastewater pipeline through a first pipeline, and the refrigerant outlet of the first heat exchanger is connected to the steam mixing device through a second pipeline; the second heat exchanger is connected to the tobacco washing wastewater pipeline through a third pipeline; A steam delivery pipeline is provided at the steam outlet of the steam mixing device; a branch pipeline is provided between the second pipeline and the steam delivery pipeline; The control device comprises a temperature detection and control device arranged on the second pipeline, a first valve arranged on the first pipeline and interlocked with the signal of the temperature detection and control device, a second valve arranged at the inlet of the steam mixing device, a third valve arranged on the third pipeline and a fourth valve arranged on the branch pipeline; It also includes a tobacco washing wastewater regulating tank; The tobacco washing wastewater regulating tank is connected to the heat medium outlets of the first heat exchanger and the second heat exchanger respectively; The steam mixing device comprises a steam mixer; The steam mixer is connected to the anaerobic reactor through the steam delivery pipeline.

2. The device for co-heating tobacco washing wastewater and leachate according to claim 1 is characterized in that: The first heat exchanger is a plate heat exchanger; and / or, The second heat exchanger is a plate heat exchanger.

3. The device for co-heating tobacco washing wastewater and leachate according to claim 1, characterized in that: The temperature detection and control device includes a temperature detection instrument and a control unit connected to the temperature detection instrument, and the control unit is electrically connected to the first valve, the second valve, the third valve and the fourth valve respectively.

4. The device for co-heating tobacco washing wastewater and leachate according to claim 3 is characterized in that: The first valve, the second valve, the third valve and the fourth valve are all electromagnetic valves.

5. The device for co-heating tobacco washing wastewater and leachate according to claim 3 is characterized in that: The control unit includes a single chip microcomputer.

6. A method for synergistically preheating tobacco washing wastewater and leachate, characterized in that: The method of using the tobacco washing wastewater and leachate collaborative preheating device as claimed in any one of claims 1 to 5 to collaboratively preheat the tobacco washing wastewater and leachate comprises the following steps: Open the first valve and close the third valve, so that the leachate and the tobacco washing wastewater enter the first heat exchanger for heat exchange, and the leachate after heat exchange in the first heat exchanger enters the second pipeline; The temperature of the leachate in the second pipeline is detected by the temperature detection and control device to obtain a detected temperature; When the detected temperature is lower than the preset temperature, the fourth valve is closed, and the second valve is opened, so that the leachate in the second pipeline enters the steam mixing device, and the leachate is kept warm and heated by the steam mixing device until the leachate reaches the preset temperature, and then is transported through the steam transport pipeline; When the detected temperature is equal to the preset temperature, the fourth valve is opened, and the second valve is closed, so that the leachate in the second pipeline is transported to the steam delivery pipeline through the branch pipeline, and then transported by the steam delivery pipeline; When the detected temperature is higher than the preset temperature, the first valve is closed, the third valve is opened, and the flow of the tobacco washing waste water in the first heat exchanger is adjusted to cool the leachate entering the first heat exchanger. The cooled leachate enters the second pipeline, and the fourth valve and the second valve are controlled based on the comparison between the detected temperature of the leachate in the second pipeline and the preset temperature.

7. The method for synergistically preheating tobacco washing wastewater and leachate according to claim 6, characterized in that: The preset temperature is 35°C-40°C.

Images