VOCs waste gas treatment system for semi-coke production

Abstract

The utility model provides a VOCs waste gas treatment system for semi-coke production. The VOCs waste gas treatment system comprises a washing tower, a dust removal drying box and a semi-coke furnace which are sequentially communicated through pipelines, the upper section of the washing tower is communicated with a cooling water pipeline, the lower section of the washing tower is communicated with a first VOCs source through a first pipeline, and a fan is arranged on the pipeline between the dust removal drying box and the semi-coke furnace; a partition plate used for dividing the waste liquid box into a precipitation cavity and a circulating water cavity is arranged in the waste liquid box, and an overflow hole is formed in the partition plate; the precipitation cavity is respectively communicated with the bottom of the washing tower and the side wall of the lower section through a second pipeline and a third pipeline and is communicated with a second VOCs source through a fourth pipeline, the fourth pipeline is communicated with the circulating water cavity through a fifth pipeline, and a spraying pump is arranged on the fifth pipeline. According to the method, the washed VOCs waste gas is introduced into the semi-coke furnace to replace air for combustion-supporting incineration, so that secondary utilization of the VOCs waste gas is realized.

Description

Technical Field

[0001] This application relates to the field of semi-coke technology, and in particular to a VOCs waste gas treatment system for semi-coke production. Background Technology

[0002] Semi-coke, produced by burning refined coal lumps, is a new type of carbon material. With its high fixed carbon content, high resistivity, high chemical activity, and low ash, aluminum, sulfur, and phosphorus content, it is gradually replacing metallurgical coke and is widely used in the production of calcium carbide, ferroalloys, ferrosilicon, silicon carbide, and other products, becoming an irreplaceable carbon material. Semi-coke can replace coke (metallurgical coke) and is widely used in chemical, metallurgical, and gasification industries.

[0003] However, the production of semi-coke inevitably generates a large amount of VOCs (mainly tar gas, hydrogen, carbon monoxide, carbon dioxide, methane, nitrogen, oxygen, etc.). For example, during the carbonization and coking process of semi-coke, the furnace top, coke outlet tunnel, coke transfer chute, tar tank, ammonia tank, and tar loading all generate a large amount of VOCs, which carry a large amount of tar. Therefore, to avoid the waste of tar, hydrogen, carbon monoxide, methane, etc., and the environmental pollution caused by carbon dioxide and other gases due to the emission of VOCs generated during the carbonization and coking process of semi-coke, this application proposes a VOCs waste gas treatment system for semi-coke production. Utility Model Content

[0004] This application provides a VOCs waste gas treatment system for semi-coke production to solve the technical problems described in the background art.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0006] This application provides a VOCs waste gas treatment system for semi-coke production, comprising: a scrubbing tower, a dust removal and drying box, and a semi-coke furnace connected in sequence by pipelines;

[0007] The upper section of the washing tower is connected to a cooling water pipe, and its lower section is connected to a first VOCs source through a first pipe. A fan is installed on the pipe between the dust removal drying box and the semi-coke furnace. A waste liquid tank is provided, and a partition is provided inside the waste liquid tank to divide it into a sedimentation chamber and a circulating water chamber. An overflow hole is provided on the partition. The sedimentation chamber is connected to the bottom and the side wall of the lower section of the washing tower through a second pipe and a third pipe, respectively. It is connected to a second VOCs source through a fourth pipe. The fourth pipe is connected to the circulating water chamber through a fifth pipe. A spray pump is installed on the fifth pipe.

[0008] Optionally, a first water pump is installed on the cooling water pipeline;

[0009] One end of the cooling water pipe that connects to the washing tower extends through and into the washing tower, and multiple spray heads are installed on the pipe body located inside the washing tower.

[0010] Optionally, one end of the second pipe away from the washing tower is connected to the top of the sedimentation chamber;

[0011] The second pipeline is equipped with a first flow regulating valve.

[0012] Optionally, the sedimentation chamber is provided with a visual observation window and its bottom is connected to a tar recovery pipe.

[0013] Optionally, a liquid level sensor is installed in the circulating water chamber, the circulating water chamber is connected to a cooler through a sixth pipe, and the outlet of the cooler is connected to the cooling water pipe through a seventh pipe.

[0014] A second water pump, electrically connected to the liquid level sensor, is installed on the seventh pipeline.

[0015] Optionally, the sixth pipe is provided with a second flow regulating valve that is electrically connected to the liquid level sensor.

[0016] Optionally, a third flow regulating valve may be provided on both the first pipe and the fourth pipe.

[0017] Optionally, the end of the cooling water pipe away from the washing tower is connected to a cooling water source that supplies cooling water to the washing tower.

[0018] The VOCs waste gas treatment system for semi-coke production provided in this application introduces cooling water into a scrubbing tower via a cooling water pipe. VOCs waste gas from a first VOCs source is fed into the scrubbing tower through the first pipe for washing, removing tar from the waste gas. The waste water is then discharged into a sedimentation chamber through a second pipe connected to the bottom of the scrubbing tower. After sedimentation in the sedimentation chamber (tar at the bottom, water at the top), the water at the top flows into a circulating water chamber through overflow holes on a baffle plate. A spray pump then pumps the water from the circulating water chamber through a fifth pipe to a fourth pipe, cooling and washing the high-temperature VOCs waste gas from the second VOCs source that enters the fourth pipe (removing tar from the VOCs waste gas from the second VOCs source). The wastewater after the first washing flows into the sedimentation chamber. The VOCs waste gas from the second VOCs source, after cooling treatment, enters the scrubbing tower through the sedimentation chamber and a third pipe connected to the sedimentation chamber for secondary scrubbing. Both the scrubbed VOCs waste gas from the first VOCs source and the scrubbed VOCs waste gas from the second VOCs source enter the dust removal and drying chamber from the scrubbing tower. The dust removal and drying chamber removes dust from the VOCs waste gas entering it. The dust-removed and dried VOCs waste gas is then fed into the semi-coke furnace by a fan. The combustible gases such as hydrogen, carbon monoxide, and methane in the VOCs waste gas can be used as fuel for combustion in the semi-coke furnace, while the oxygen in the VOCs waste gas can be used as the oxygen required for combustion. In other words, the scrubbed VOCs waste gas can replace air for combustion in the semi-coke furnace, thus achieving the secondary utilization of VOCs waste gas. Furthermore, this application improves the recovery efficiency and utilization rate of tar by recovering and utilizing the tar precipitated in the lower layer of the sedimentation chamber (e.g., tar can be used as a waterproofing material and asphalt material). Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a VOCs waste gas treatment system for semi-coke production provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the structure of a VOCs waste gas treatment system for semi-coke production provided in an embodiment of this application;

[0022] Figure 3A schematic diagram of a structure in which multiple spray heads are installed on the cooling water pipes inside a washing tower according to an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of the internal structure of a waste liquid tank provided in an embodiment of this application.

[0024] In the diagram: 101, Pipeline; 1011, Fan; 102, Cooling water pipeline; 1021, First water pump; 1022, Spray head; 103, First pipeline; 1031, Third flow control valve; 104, Second pipeline; 1041, First flow control valve; 105, Third pipeline; 106, Fourth pipeline; 107, Fifth pipeline; 1071, Spray pump; 108, Sixth pipeline; 1081, Second flow control valve; 109. 7th Pipeline; 1091, Second Water Pump; 200, Scrubber; 300, Dust Removal and Drying Box; 400, Semi-coke Furnace; 500, First VOCs Source; 600, Waste Liquid Tank; 601, Sedimentation Chamber; 6011, Visual Observation Window; 6012, Tar Recovery Pipe; 6013, Shut-off Valve; 602, Circulating Water Chamber; 603, Baffle Plate; 6031, Overflow Hole; 700, Second VOCs Source; 800, Cooler; 900, Cooling Water Source. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0026] refer to Figures 1 to 4This application provides a VOCs waste gas treatment system for semi-coke production, including: a scrubbing tower 200, a dust removal and drying box 300, and a semi-coke furnace 400 connected in sequence by a pipe 101; wherein, the end of the pipe 101 between the dust removal and drying box 300 and the semi-coke furnace 400 away from the dust removal and drying box 300 is connected to the air inlet of the semi-coke furnace 400, so as to introduce the VOCs waste gas for semi-coke production after being washed by the scrubbing tower 200 and dust removed and dried by the dust removal and drying box 300 into the semi-coke furnace 400. The purpose of this is that a large amount of VOCs waste gas is inevitably generated during the semi-coke production process. The VOCs waste gas mainly contains tar gas, hydrogen, carbon monoxide, carbon dioxide, methane, nitrogen, oxygen and other substances. If the VOCs waste gas is directly discharged, it will waste the combustible gases (tar gas, hydrogen, carbon monoxide, methane, etc.) and the combustion-supporting gases (oxygen) in the VOCs waste gas, and carbon monoxide and other substances will also pollute the environment. Therefore, in order to avoid the above situation, this application introduces the VOCs waste gas generated during the semi-coke production process into the operating semi-coke furnace 400 after washing, dust removal and drying. The combustion-supporting gas (oxygen) entering the semi-coke furnace 400 can make the original combustion of the semi-coke furnace 400 more vigorous. At the same time, the combustible gases (tar gas, hydrogen, carbon monoxide, methane, etc.) entering the semi-coke furnace 400 can be burned in the semi-coke furnace 400 and provide fuel for the semi-coke furnace 400, thereby improving the combustion efficiency of the semi-coke furnace 400.

[0027] It is important to note that the semi-coke furnace 400 is in a combustion state during its normal operation, and the fuel it burns is semi-coke that has undergone dry distillation. Specifically, the semi-coke is transported to the combustion chamber of the semi-coke furnace 400 via a dedicated conveying system, and air (as a combustion aid) is introduced into the combustion chamber to preheat the mixture of semi-coke and air until its temperature reaches the combustion temperature of the semi-coke, thus initiating combustion. Therefore, the oxygen in the VOCs waste gas generated during the semi-coke production process is not a combustion aid supporting the combustion of the semi-coke furnace itself. Rather, because the VOCs waste gas contains oxygen and combustible gases, introducing it into the burning semi-coke furnace 400 utilizes the VOCs waste gas generated during the semi-coke production process, avoiding pollution caused by direct discharge of VOCs waste gas and the waste of combustible gases and combustion aids.

[0028] The upper section of the washing tower 200 is connected to a cooling water pipe 102, and its lower section is connected to a first VOCs source 500 through a first pipe 103. A fan 1011 is installed on the pipe 101 between the dust removal drying box 300 and the semi-coke furnace 400. The first VOCs source 500 can be VOCs waste gas generated during the coke conveying process of the coke belt.

[0029] The waste liquid tank 600 is equipped with a partition 603 that divides it into a sedimentation chamber 601 and a circulating water chamber 602. The partition 603 has an overflow hole 6031. The sedimentation chamber 601 is connected to the bottom and lower side wall of the scrubbing tower 200 via a second pipe 104 and a third pipe 105, respectively. It is also connected to a second VOCs source 700 via a fourth pipe 106. The fourth pipe 106 is connected to the circulating water chamber 602 via a fifth pipe 107, on which a spray pump 1071 is installed. The overflow hole 6031 is located near the top of the partition 603, allowing the tar in the wastewater entering the sedimentation chamber 601 to settle sufficiently, thus achieving tar and water separation. The second VOCs source 700 can be the VOCs waste gas generated from the top of the semi-coke furnace 400, tar tank, ammonia tank, tar loading, etc. The temperature of its VOCs waste gas is higher than that of the VOCs waste gas generated by the first VOCs source 500. In this application, water in the circulating water chamber 602 is pumped through the fifth pipe 107 to the VOCs waste gas of the second VOCs source 700 entering the fourth pipe 106 by the spray pump 1071. In this way, the VOCs waste gas of the second VOCs source 700 is flushed and cooled by water, avoiding the high temperature of the second VOCs source VOCs waste gas from directly entering the scrubbing tower 200, which would cause the temperature in the scrubbing tower 200 to be too high and cause some of the cooling water entering the scrubbing tower 200 to vaporize. This ensures the scrubbing efficiency of the cooling water on the VOCs waste gas entering the scrubbing tower 200. Furthermore, the bottom end of the fourth pipe 106 is lower than the height of the overflow hole 6031 (this is to prevent the washing wastewater flowing from the bottom end of the fourth pipe 106 from flowing into the circulating water chamber 602 through the overflow hole 6031, thereby ensuring the purity of the water in the circulating water chamber 602). This allows the wastewater after washing in the fourth pipe 106 to flow into the sedimentation chamber 601, while the VOCs waste gas, after being washed and cooled once, enters the scrubbing tower 200 through the space above the liquid surface in the sedimentation chamber 601 and through the third pipe 105, ensuring the flow efficiency of the VOCs waste gas. This application improves the tar recovery efficiency and utilization rate by recovering and utilizing the tar settled in the lower layer of the sedimentation chamber 601 (for example, tar can be used as a waterproof material and asphalt material).

[0030] In practical application, the VOCs waste gas treatment system for semi-coke production provided in this application introduces cooling water into the scrubbing tower 200 through the cooling water pipe 102. The VOCs waste gas generated by the first VOCs source 500 is then introduced into the scrubbing tower 200 through the first pipe 103 for scrubbing. This washes away the tar contained in the VOCs waste gas, and the wastewater is discharged into the sedimentation chamber 601 through the second pipe 104 connected to the bottom of the scrubbing tower 200 along with the scrubbing wastewater. The scrubbing wastewater then settles in the sedimentation chamber 601. Afterwards (the lower layer is tar, the upper layer is water), the water in the upper layer flows into the circulating water chamber 602 through the overflow hole 6031 on the partition 603. Then, the water in the circulating water chamber 602 is pumped into the fourth pipe 106 through the fifth pipe 107 by the spray pump 1071. This cools down and performs a primary washing treatment on the high-temperature VOCs waste gas generated from the second VOCs source 700 and entering the fourth pipe 106 (washing away the tar in the VOCs waste gas from the second VOCs source 700). The waste gas after the primary washing... Water flows into the sedimentation chamber 601, while the VOCs exhaust gas from the second VOCs source 700, after cooling treatment, enters the scrubbing tower 200 through the sedimentation chamber 601 and the third pipe 105 connected to the sedimentation chamber 601 for secondary scrubbing. The VOCs exhaust gas from the first VOCs source 500 after scrubbing, and the VOCs exhaust gas from the second VOCs source 700 after secondary scrubbing, both enter the dust removal and drying box 300 from the scrubbing tower 200. The dust removal and drying box 300 then processes the VOCs exhaust gas. The VOCs waste gas entering the furnace is dusted and dried. The dust-treated and dried VOCs waste gas is then fed back into the semi-coke furnace 400 by the fan 1011. The combustible gases such as hydrogen, carbon monoxide and methane in the VOCs waste gas are used as fuel for combustion in the semi-coke furnace 400, while the oxygen in the VOCs waste gas can be used as the oxygen required for combustion in the semi-coke furnace 400. In other words, the washed VOCs waste gas can be fed into the semi-coke furnace 400 to replace air for combustion, thus realizing the secondary utilization of VOCs waste gas.

[0031] In some embodiments, reference Figure 2 and Figure 3 In this application, a first water pump 1021 is provided on the cooling water pipe 102; wherein, the first water pump 1021 provides the power to transport cooling water through the cooling water pipe 102 into the washing tower 200.

[0032] One end of the cooling water pipe 102, which connects to the scrubbing tower 200, extends into the scrubbing tower 200, and multiple spray heads 1022 are installed on the pipe inside the scrubbing tower 200. The water outlet of the spray head 1022 faces the bottom of the scrubbing tower 200. The multiple spray heads 1022 spray cooling water into the scrubbing tower 200, so that the cooling water is evenly distributed in the scrubbing tower 200, thereby improving the cooling and scrubbing efficiency of the cooling water flowing from top to bottom of the scrubbing tower 200 on the VOCs waste gas diffusing from bottom to top in the scrubbing tower 200.

[0033] In some embodiments, reference Figure 2 In this application, the end of the second pipe 104 away from the washing tower 200 is connected to the top of the sedimentation chamber 601; wherein, the washing wastewater in the washing tower 200 flows into the sedimentation chamber 601 through the second pipe 104 and settles in the sedimentation chamber 601, thereby realizing the separation of tar and water in the washing wastewater.

[0034] The second pipeline 104 is equipped with a first flow regulating valve 1041, which regulates the flow rate of washing wastewater from the washing tower 200 into the sedimentation chamber 601.

[0035] In some embodiments, reference Figure 2 In this application, the sedimentation chamber 601 is provided with a visual observation window 6011 and its bottom is connected to a tar recovery pipe 6012, and a shut-off valve 6013 is provided on the tar recovery pipe 6012.

[0036] In the above embodiment, when the height of the tar deposited in the sedimentation chamber 601 is high as observed through the visual observation window 6011, the first flow regulating valve 1041 is closed, and the shut-off valve 6013 on the tar recovery pipe 6012 is opened to release the tar in the sedimentation chamber 601, so that the sedimentation chamber 601 has enough space to hold the washing wastewater flowing into it from the washing tower 200.

[0037] In some embodiments, reference Figure 2 The circulating water chamber 602 in this application is equipped with a liquid level sensor. The circulating water chamber 602 is connected to a cooler 800 through a sixth pipe 108. The outlet of the cooler 800 is connected to the cooling water pipe 102 through a seventh pipe 109. The liquid level in the circulating water chamber 602 is detected by the liquid level sensor.

[0038] In addition, a second water pump 1091 electrically connected to the liquid level sensor is installed on the seventh pipe 109.

[0039] In the above embodiment, when the liquid level sensor detects that the liquid level in the circulating water chamber 602 is higher than the preset threshold (which can be set according to actual needs, and this application does not specifically limit it here), the second water pump 1091, which is electrically connected to the liquid level sensor, is turned on. The water in the circulating water chamber 602 enters the cooler 800 through the sixth pipe 108. After being cooled by the cooler 800, the water flows into the cooling water pipe 102 through the seventh pipe 109, and is used again as cooling water to wash and cool the VOCs waste gas entering the scrubbing tower 200, thereby realizing the recycling of cooling water.

[0040] It should be noted that since the cooler 800 contains a filter screen, even if the circulating water chamber 602 contains some tar, the tar in the water flowing from the circulating water chamber 602 to the cooler can be filtered by setting the mesh diameter of the filter screen of the cooler 800 to be smaller than the particle size of the tar. At the same time, in order to ensure the cooling effect of the cooler 800, the filter screen in the cooler 800 can be replaced periodically.

[0041] In some embodiments, reference Figure 2 The sixth pipe 108 in this application is provided with a second flow regulating valve 1081 that is electrically connected to the liquid level sensor.

[0042] In the above embodiment, the opening and closing of the second flow regulating valve 1081 and the opening degree are adjusted according to the liquid level detected by the liquid level sensor in the circulating water chamber 602. Under the premise of ensuring that there is enough water in the circulating water chamber 602 to enter the fifth pipe 107 to flush and cool the VOCs exhaust gas of the second VOCs source 700 entering the fourth pipe 106, the water level in the circulating water chamber 602 is prevented from being too high, causing the water in the chamber to flow back into the sedimentation chamber 601 through the overflow hole 6031 on the partition 603.

[0043] In some embodiments, reference Figure 2 In this application, a third flow regulating valve 1031 is provided on both the first pipe 103 and the fourth pipe 106.

[0044] In the above embodiment, the flow rate of VOCs waste gas entering the first VOCs source 500 is adjusted by the third flow regulating valve 1031 on the first pipe 103, so that the VOCs waste gas entering the first VOCs source 500 in the scrubbing tower 200 can be fully scrubbed and cooled. Additionally, the flow rate of VOCs waste gas entering the second VOCs source 700 is adjusted by the third flow regulating valve 1031 on the fourth pipe 106, so that the VOCs waste gas in the fourth pipe 106 can be fully scrubbed and cooled by water from the fifth pipe 107.

[0045] In some embodiments, reference Figure 2In this application, the end of the cooling water pipe 102 away from the scrubbing tower 200 is connected to a cooling water source 900 that supplies cooling water to the scrubbing tower 200.

[0046] In the above embodiment, cooling water is supplied to the scrubbing tower 200 through the cooling water source 900 to ensure the continuity of the cooling water. The VOCs waste gas entering the scrubbing tower 200 is then cooled and scrubbed by the cooling water, thereby improving the scrubbing and cooling efficiency of the VOCs waste gas in the scrubbing tower 200.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A VOCs exhaust gas treatment system for production of blue water, characterized by, include: The washing tower (200), the dust removal and drying box (300) and the semi-coke furnace (400) are connected in sequence through the pipeline (101). The upper section of the washing tower (200) is connected to a cooling water pipe (102), and its lower section is connected to a first VOCs source (500) through a first pipe (103). A fan (1011) is installed on the pipe (101) between the dust removal drying box (300) and the semi-coke furnace (400). Waste liquid tank (600), the waste liquid tank (600) is provided with a partition (603) for dividing it into a sedimentation chamber (601) and a circulating water chamber (602), the partition (603) is provided with an overflow hole (6031); the sedimentation chamber (601) is connected to the bottom and the lower side wall of the scrubbing tower (200) through a second pipe (104) and a third pipe (105) respectively, and is connected to a second VOCs source (700) through a fourth pipe (106), the fourth pipe (106) is connected to the circulating water chamber (602) through a fifth pipe (107), and a spray pump (1071) is provided on the fifth pipe (107).

2. The VOCs off-gas treatment system for producing blue water according to claim 1, characterized by, A first water pump (1021) is installed on the cooling water pipe (102); One end of the cooling water pipe (102) that is connected to the washing tower (200) passes through and extends into the washing tower (200), and multiple spray heads (1022) are provided on the pipe body located in the washing tower (200).

3. The VOCs off-gas treatment system for producing blue water according to claim 1, characterized by, The end of the second pipe (104) away from the washing tower (200) is connected to the top of the sedimentation chamber (601); The second pipe (104) is equipped with a first flow regulating valve (1041).

4. The VOCs off-gas treatment system for producing blue water according to claim 3, characterized by, The sedimentation chamber (601) is provided with a visual observation window (6011) and its bottom is connected to a tar recovery pipe (6012).

5. The VOCs waste gas treatment system for semi-coke production according to claim 1, characterized in that, A liquid level sensor is installed in the circulating water chamber (602). The circulating water chamber (602) is connected to a cooler (800) through a sixth pipe (108). The outlet of the cooler (800) is connected to the cooling water pipe (102) through a seventh pipe (109). The seventh pipeline (109) is equipped with a second water pump (1091) that is electrically connected to the liquid level sensor.

6. The VOCs off-gas treatment system for producing blue water according to claim 5, characterized by, The sixth pipe (108) is equipped with a second flow regulating valve (1081) that is electrically connected to the liquid level sensor.

7. The VOCs off-gas treatment system for producing blue water according to any one of claims 1 to 6, characterized by, Both the first pipe (103) and the fourth pipe (106) are equipped with a third flow regulating valve (1031).

8. The VOCs off-gas treatment system for producing blue water according to any one of claims 1 to 6, characterized by, The end of the cooling water pipe (102) away from the scrubbing tower (200) is connected to a cooling water source (900) that supplies cooling water to the scrubbing tower (200).

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