Carbide slag slurry waste heat recovery system

Abstract

A carbide slag slurry waste heat recovery system belongs to the technical field of energy conservation and environmental protection. The carbide slag slurry waste heat recovery device solves the problems that waste heat of carbide slag slurry is wasted due to the fact that existing conventional heat exchange equipment is difficult to achieve waste heat recovery, and the utilization rate of raw material calcium carbide is low due to the fact that acetylene gas wrapped in the carbide slag slurry cannot be effectively recovered. A liquid outlet of the desorption tower is respectively communicated with a liquid inlet of the flash-tank and the clarification tank through pipelines, an electric valve is arranged on a connecting pipeline between the desorption tower and the clarification tank, the bottom of the flash-tank is connected to the clarification tank through a water return pipeline, a flash steam outlet of the flash-tank is communicated with a steam inlet of the condenser, and a steam outlet of the condenser is communicated with a steam outlet of the condenser. The two ends of a heat exchange pipe in the condenser are connected to a heat user through a water supply pipe and a water return pipe respectively, the lower portion of the condenser is connected with a condensate water tank through a pipeline, and the acetylene gas buffer tank is communicated with the condenser through a vacuum pump. The waste heat recovery system can effectively recover heat in the carbide slag slurry for building heating.

Description

Technical Field

[0001] The utility model relates to a carbide slag slurry waste heat recovery system, belonging to the technical field of energy conservation and environmental protection. Background Art

[0002] Polyvinyl chloride (PVC) is a widely used chemical product. More than 80% of PVC in China is produced by the coal-based carbide method. During the process, a large amount of carbide slag slurry is discharged when carbide is hydrolyzed to prepare acetylene gas. The temperature of the carbide slurry is about 60-70°C. After entering the clarifier, it needs to be cooled to 40°C by a cooling tower. In the process of using the carbide method for polyvinyl chloride, carbide particles and water will react to generate raw acetylene gas. However, due to the incomplete reaction of large carbide particles, dissolved acetylene gas, oversaturation of slurry or entrainment of carbide slag, 0.7%-1.5% of acetylene gas flows out of the generator along with the carbide slurry.

[0003] Most chlor-alkali enterprises process acetylene gas by means of external discharge and filtration of carbide slag slurry. In this way, the acetylene gas will be lost and volatilized. On the one hand, this method reduces the utilization rate of raw material carbide, and on the other hand, the production cost of the enterprise increases accordingly, and it also causes pollution to the surrounding environment.

[0004] Calcium carbide slag slurry is a three-phase heterogeneous fluid, which is a solid particle or powder that entrains acetylene gas and then is mixed in water. Calcium carbide slag slurry has physical properties including high viscosity, high hardness, high solid content, and easy deposition. Therefore, it is very easy to cause problems such as blockage, scaling, and corrosion of heat exchange equipment during the heat exchange process. Conventional heat exchange equipment is difficult to achieve waste heat recovery, resulting in a waste of waste heat resources of calcium carbide slag slurry. At the same time, the acetylene gas entrained in the calcium carbide slag slurry cannot be effectively recovered, resulting in a low utilization rate of the raw material calcium carbide, high production costs, and environmental pollution. Utility Model Content

[0005] The utility model is to solve the above technical problems and further provides a carbide slag slurry waste heat recovery system.

[0006] The technical solution adopted by the utility model to solve the above technical problems is:

[0007] A carbide slag waste heat recovery system comprises a desorption tower, a flash generator, a condenser, a vacuum pump, an acetylene gas buffer tank and a clarifier, wherein the liquid outlet of the desorption tower is connected to the liquid inlet of the flash generator and the clarifier through pipelines, and an electric valve is arranged on the connecting pipeline between the desorption tower and the clarifier, and the bottom of the flash generator is connected to the clarifier through a water withdrawal pipeline.

[0008] The flash steam outlet of the flasher is connected to the steam inlet of the condenser.

[0009] Both ends of the heat exchange tube in the condenser are connected to the heat user through the water supply pipe and the water return pipe.

[0010] The lower part of the condenser is connected to a condensed water tank through a pipeline.

[0011] The acetylene gas buffer tank is communicated with the condenser through a vacuum pump.

[0012] Furthermore, the flasher and the condenser are communicated with each other through a steam channel.

[0013] Furthermore, the flasher is a multi-effect flasher, and the condenser is a multi-effect condenser and is connected to the multi-effect flasher in a one-to-one correspondence.

[0014] Furthermore, the flasher is a triple-effect flasher.

[0015] Further, the vacuum pump is connected to the bottom of the condenser.

[0016] Furthermore, a water withdrawal pump is provided on the water withdrawal pipeline.

[0017] Furthermore, a heating water circulation pump is provided on the return water pipe.

[0018] Furthermore, the liquid outlet of the separation tower is arranged at the upper part thereof, and the liquid inlet of the separation tower is arranged at the lower part thereof.

[0019] Compared with the prior art, the utility model has the following effects:

[0020] Due to the high consistency, high hardness, high solid content and easy deposition of calcium carbide slag slurry, the use of conventional partition-type heat exchangers is prone to pollution, blockage, corrosion and other problems. Through the waste heat recovery system of the utility model, the steam flashed by the flasher is clean steam, which transfers heat to the heating water, and the calcium carbide slag slurry does not contact the heat transfer wall surface, which effectively solves the problems existing in the prior art when recovering the waste heat of calcium carbide slag slurry through a partition-type heat exchanger; and through the waste heat recovery system of the utility model, the heat in the calcium carbide slag slurry can be effectively recovered for building heating;

[0021] By connecting a condensate tank at the bottom of the condenser, the flash condensate can be recovered to effectively save water resources;

[0022] By setting up a vacuum pump, not only can flash evaporation conditions be provided for the carbide slag slurry in the flasher, but the acetylene gas in the carbide slag slurry can also be effectively recovered for reuse in the production process, thus saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the system composition of the utility model.

[0024] In the figure:

[0025] 100, separation tower; 200, flasher; 300, steam channel; 400, condenser; 500, vacuum pump; 600, acetylene gas buffer tank; 700, heat user;

[0026] 102, electric valve; 104, clarification tank; 202, return water pipeline; 203, return water pump; 302, condensate tank; 401, water supply pipe; 402, return water pipe; 403, heating water circulation pump; 501, suction pipeline; 502, exhaust pipeline. DETAILED DESCRIPTION

[0027] Specific implementation method 1: Combination Figure 1 This implementation mode is explained by clearly and completely describing the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0028] It should be noted that the descriptions of the present invention regarding directions such as "left", "right", "left side", "right side", "upper", "lower", "top", "bottom", etc. are all defined based on the relationship between the orientations or positions shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure described must be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention. In the description of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0029] In the description of the present invention, 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] A carbide slag waste heat recovery system includes a desorption tower 100, a flasher 200, a condenser 400, a vacuum pump 500, an acetylene gas buffer tank 600 and a clarifier 104, wherein the liquid outlet of the desorption tower 100 is connected to the liquid inlet of the flasher 200 and the clarifier 104 through pipelines, and an electric valve 102 is provided on the connecting pipeline between the desorption tower 100 and the clarifier 104, and the bottom of the flasher 200 is connected to the clarifier 104 through a water withdrawal pipeline 202.

[0031] The flash steam outlet of the flash generator 200 is connected to the steam inlet of the condenser 400.

[0032] Both ends of the heat exchange tube in the condenser 400 are connected to the heat user 700 through the water supply pipe 401 and the water return pipe 402 respectively.

[0033] The lower part of the condenser 400 is connected to a condensed water tank 302 through a pipeline.

[0034] The acetylene gas buffer tank 600 is connected to the condenser 400 via the vacuum pump 500 .

[0035] The vacuum pump 500 is connected to the condenser 400 via an air intake pipeline 501 , and the vacuum pump 500 is connected to the acetylene gas buffer tank 600 via an air exhaust pipeline 502 .

[0036] Due to the high consistency, high hardness, high solid content and easy sedimentation of carbide slag slurry, the use of conventional partition-type heat exchangers is prone to pollution, blockage, corrosion and other problems. The waste heat recovery system of the utility model effectively solves the problems existing in the prior art when recovering the waste heat of carbide slag slurry through partition-type heat exchangers; and the waste heat recovery system of the utility model can effectively recover the heat in the carbide slag slurry for building heating;

[0037] By connecting a condensed water tank 302 to the lower part of the condenser 400, the flash condensed water is recovered, thereby effectively saving water resources;

[0038] By providing the vacuum pump 500, not only can flash evaporation conditions be provided for the carbide slag slurry in the flasher 200, but the acetylene gas in the carbide slag slurry can also be effectively recovered for reuse in the production process, thereby saving production costs.

[0039] Working principle:

[0040] The carbide slag slurry enters the separation tower 100 from the liquid inlet of the separation tower 100 and flows out from the liquid outlet at the upper part of the separation tower 100.

[0041] In a conventional production process, the electric valve 102 is opened, and the carbide slag slurry flowing out from the upper liquid outlet of the desorption tower 100 enters the clarification tank 104 through the connecting pipeline between the desorption tower 100 and the clarification tank 104 .

[0042] When taking heat, close the electric valve 102, and the carbide slag slurry enters the flasher 200 through the connecting pipeline between the desorption tower 100 and the flasher 200. Start the vacuum pump 500 to make the internal pressure of the flasher 200 reach the flash pressure corresponding to the temperature of the carbide slag slurry. At this time, the carbide slag slurry flashes, and the negative pressure steam enters the condenser 400 through the steam channel 300 to condense and release heat to become condensed water. The condensed water enters the condensed water tank 302 through the condensed water pipeline to be collected and reused. The carbide slag slurry after flash evaporation in the flasher 200 enters the clarification tank 104 through the water withdrawal pipeline 202. The carbide slag slurry only circulates in the flasher 200. The salts precipitated by cooling and crystallizing enter the clarification tank 104 through the water withdrawal pipeline 202 together with the slurry, and do not contact the heat exchange wall surface, and will not block the heat exchange wall surface.

[0043] The heating water enters the condenser 400 through the return pipe 402, absorbs the heat released by the condensation of the negative pressure steam, enters the heat user 700 through the water supply pipe 401 to release heat, and the heating water after heat release returns to the condenser 400 through the return pipe 402 to be heated, and this process is repeated.

[0044] After the carbide slag slurry is flashed, the temperature is lowered, and non-condensable gases such as acetylene gas overflow. The non-condensable gas is extracted by the vacuum pump 500 and discharged into the acetylene buffer tank, and the acetylene gas is recovered after cooling.

[0045] The flasher 200 is connected to the condenser 400 through the steam channel 300. With such a design, the cross-sectional area of ​​the steam channel 300 is much larger than the steam pipe, which effectively increases the circulation speed of the flash steam and thus effectively increases the heat exchange efficiency of the condenser 400.

[0046] The flasher 200 is a multi-effect flasher, and the condenser 400 is a multi-effect condenser and is connected to the multi-effect flasher in a one-to-one correspondence. This design reduces the heat transfer end difference to ensure that the heating water has the maximum temperature rise in the condenser 400.

[0047] The flasher 200 is a triple-effect flasher.

[0048] The vacuum pump 500 is connected to the bottom of the condenser 400. This design ensures the maximum heat exchange efficiency of the condenser 400.

[0049] The water withdrawal pipeline 202 is provided with a water withdrawal pump 203 .

[0050] A heating water circulation pump 403 is provided on the return water pipe 402. With such a design, the heating water circulation pump 403 is used to pressurize the heating water, so that the heating water can enter the condenser 400.

[0051] The liquid outlet of the separation tower 100 is arranged at the upper part thereof, and the liquid inlet of the separation tower 100 is arranged at the lower part thereof. The liquid inlet of the separation tower 100 is connected to an inlet pipeline.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A carbide slag waste heat recovery system, characterized in that: The invention comprises a desorption tower (100), a flash generator (200), a condenser (400), a vacuum pump (500), an acetylene gas buffer tank (600) and a clarifier (104), wherein the liquid outlet of the desorption tower (100) is connected to the liquid inlet of the flash generator (200) and the clarifier (104) through pipelines, respectively, and an electric valve (102) is arranged on the connecting pipeline between the desorption tower (100) and the clarifier (104), and the bottom of the flash generator (200) is connected to the clarifier (104) through a water withdrawal pipeline (202). The flash steam outlet of the flash generator (200) is connected to the steam inlet of the condenser (400). Both ends of the heat exchange tube in the condenser (400) are connected to the heat user (700) through a water supply pipe (401) and a water return pipe (402). The lower part of the condenser (400) is connected to a condensed water tank (302) via a pipeline. The acetylene gas buffer tank (600) is connected to the condenser (400) via a vacuum pump (500).

2. A carbide slag waste heat recovery system according to claim 1, characterized in that: The flasher (200) and the condenser (400) are communicated with each other through a steam channel (300).

3. A carbide slag waste heat recovery system according to claim 1 or 2, characterized in that: The flasher (200) is a multi-effect flasher, and the condenser (400) is a multi-effect condenser and is connected to the multi-effect flasher in a one-to-one correspondence.

4. A carbide slag waste heat recovery system according to claim 3, characterized in that: The flasher (200) is a triple-effect flasher.

5. The carbide slag waste heat recovery system according to claim 1, characterized in that: The vacuum pump (500) is connected to the bottom of the condenser (400).

6. The carbide slag waste heat recovery system according to claim 1, characterized in that: The water withdrawal pipeline (202) is provided with a water withdrawal pump (203).

7. The carbide slag waste heat recovery system according to claim 1, characterized in that: The return water pipe (402) is provided with a heating water circulation pump (403).

8. The carbide slag waste heat recovery system according to claim 1, characterized in that: The liquid outlet of the separation tower (100) is arranged at the upper part thereof, and the liquid inlet of the separation tower (100) is arranged at the lower part thereof.

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