A comprehensive gas recycling system in flake caustic soda production

Abstract

The application relates to the technical field of flake caustic soda production, and discloses a comprehensive gas recycling system in flake caustic soda production. The coal gas generating device is arranged, and the coal gas is introduced into each furnace table. The flue gas and alkali steam generated in the multiple digestion groups are comprehensively recycled through the main pipeline. Therefore, only one negative pressure fan needs to be arranged at the end of the main pipeline to perform air induction. The heat exchanger is arranged, so that the high-temperature flue gas and alkali steam in the main pipeline and the low-temperature alkali liquor in the feeding pipe are subjected to heat exchange, and the heating time can be saved. After the flue gas and alkali steam in the main pipeline are cooled in the heat exchanger, the liquefied alkali-containing water can be introduced into the collecting pool for recycling. On one hand, the environmental pollution is avoided, and on the other hand, the alkali-containing water in the collecting pool can be used to replace cooling water to perform cooling and spraying operations in the whole production system, so that water consumption is saved.

Description

Technical Field

[0001] This application relates to the field of caustic soda production technology, specifically to a comprehensive gas recovery and utilization system in caustic soda production. Background Technology

[0002] Sodium hydroxide flakes are a white, semi-transparent, flaky solid. They are a basic chemical raw material widely used in the papermaking, synthetic detergent and soap, viscose fiber, rayon and cotton textile industries.

[0003] In the production of caustic soda flakes, liquid caustic soda needs to be added to a cooking pot for evaporation. After the water evaporates, the liquid caustic soda becomes caustic soda flakes. In the traditional large-pot method of caustic soda flake manufacturing, coal is burned directly in a furnace to provide heat. A cooking pot is set up on top of the furnace to cook the caustic soda flake raw material. Each production line has a small chimney for exhaust, which discharges the flue gas generated by the combustion of coal in the furnace. The caustic gas from the top of the cooking pot is directly released into the air.

[0004] It is evident that the existing technology has the following problems;

[0005] 1. Burning coal directly in the furnace will produce slag, coal ash, etc., which will make cleaning difficult, resulting in a dirty and messy production environment and additional cleaning costs.

[0006] 2. Each furnace and cooking pot is independent of the others, requiring separate coal addition and flue gas extraction, which makes operation cumbersome and increases the workload.

[0007] 3. The alkaline vapors generated during the cooking process were released outdoors and were not recycled.

[0008] 4. The smoke emitted by the small chimney contains a large amount of heat energy, which is not effectively utilized. Summary of the Invention

[0009] In view of the above problems, this application provides a comprehensive gas recovery and utilization system for caustic soda production, which can achieve convenient operation, reduce labor costs, and be environmentally friendly and energy-saving in the caustic soda production process.

[0010] According to one aspect of the embodiments of this application, a comprehensive gas recovery and utilization system for caustic soda production is provided. The comprehensive gas recovery and utilization system for caustic soda production includes multiple cooking groups, a heat exchanger, a gas generator, and an alkali solution tank. The heat exchanger includes a first connecting pipe and a second connecting pipe. Each cooking group includes at least one furnace platform, with a cooking pot mounted on top of the furnace platform. Evaporation pipes are connected to the top of the cooking pot, and multiple evaporation pipes are connected to a main pipe. The gas generator is connected to the air inlets of the multiple furnace platforms via pipes, and the air outlets of the furnace platforms are connected to the main pipe via pipes. The end of the main pipe is connected to the first connecting pipe of the heat exchanger. The end of the first connecting pipe branches into a water outlet pipe and a gas outlet pipe. The gas outlet pipe is connected to a chimney, and the water outlet pipe is connected to a collection tank. The alkali solution tank is connected to at least one preheating tank via a feeding pipe. The middle part of the feeding pipe is connected to the second connecting pipe, and the liquid outlet of the preheating tank is connected to the cooking pot.

[0011] In some embodiments, an air supply duct is included, the first end of which is connected to an air intake fan, and the second end of which is connected to the air inlets of a plurality of the furnace platforms.

[0012] In some embodiments, a negative pressure fan is connected to the air outlet pipe, and the air outlet of the negative pressure fan is connected to the chimney.

[0013] In some embodiments, a cooking group includes multiple stoves connected in series. The stove at the first end is connected to the gas generator via a pipe, and the stove at the last end is connected to the main pipeline via a pipe. Correspondingly, multiple cooking pots in the same cooking group are connected in series. The cooking pot at the first end is connected to the preheating tank, and the cooking pot at the last end is connected to the main pipeline via a pipe.

[0014] In some embodiments, the cooking pots at the ends of the plurality of cooking units are connected to a discharge pipe, the other end of which is connected to a sheet-making machine. The sheet-making machine is connected to a packaging machine via a auger, and the auger is connected to the main pipeline via a pipe.

[0015] In some embodiments, multiple cooking pots located in the same cooking group are connected in series via submersible pumps and pipelines.

[0016] In some embodiments, a first spray device is provided inside the cavity of the main pipe. The first spray device includes a plurality of spray nozzles and is connected to a water injection pipe that extends to the outside of the main pipe.

[0017] In some embodiments, the collection pool is connected to the water injection pipe via a pump and a pipe.

[0018] In some embodiments, a second spraying device is provided inside the winch, and the second spraying device is connected to the interior of the collection tank via a pump and a pipeline.

[0019] In some embodiments, a spray cleaning device is provided at the furnace platform, and the collection tank is connected to the spray cleaning device via a pump and pipeline.

[0020] The beneficial effects of this application are as follows: In this embodiment, by setting up a gas generator and introducing gas into each furnace, and by setting up a main pipeline to mix and recover the flue gas and alkaline vapor generated in multiple cooking groups, only a negative pressure fan needs to be set up at the end of the main pipeline to "induce air" so that the gas in each furnace can be burned and the alkaline vapor distilled from the cooking pot can be extracted. Therefore, it is not necessary to independently monitor each furnace for operations such as coal feeding. Furthermore, by setting up a heat exchanger, the high-temperature flue gas and alkaline vapor in the main pipeline exchange heat with the low-temperature alkaline solution in the feeding pipe, thereby increasing the initial heat of the alkaline solution. When the alkaline solution is added to the cooking pot from the preheating tank, the higher initial temperature saves heating time. After the flue gas and alkaline vapor in the main pipeline are cooled at the heat exchanger, the liquefied alkaline water can be introduced into a collection tank for recovery. This avoids environmental pollution and allows the alkaline water in the recovery tank to replace cooling water for cooling spraying and other operations in the entire production system, saving water consumption.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0023] Figure 1 A schematic diagram of the overall structure of the integrated gas recovery and utilization system in caustic soda production provided in this application embodiment;

[0024] Figure 2 This is a schematic diagram of an embodiment of the present application with a spray device, omitting some structures and pipes.

[0025] The reference numerals in the detailed embodiments are as follows:

[0026] The caustic soda flake production process includes a comprehensive gas recovery and utilization system 1000, a cooking group 100, a furnace platform 110, a spray cleaning device 111, a cooking pot 120, an evaporation tube 121, a heat exchanger 200, a first connecting pipe 210, a second connecting pipe 220, a gas generator 300, an alkali solution tank 400, a feeding pipe 410, a preheating tank 420, a main pipeline 500, a water outlet pipe 510, a collection tank 511, a gas outlet pipe 520, a chimney 521, a negative pressure fan 522, a first spray device 530, a spray nozzle 531, a water injection pipe 532, an air supply pipe 600, an air inlet fan 610, a discharge pipe 700, a flake making machine 800, a winch 850, a second spray device 851, and a packaging machine 900. Detailed Implementation

[0027] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and the foregoing description of the accompanying drawings are intended to cover non-exclusive inclusion.

[0028] For details, please refer to Figure 1 , Figure 1This is a schematic diagram of the overall structure of the integrated gas recovery and utilization system in caustic soda production provided in this application embodiment. The integrated gas recovery and utilization system 1000 in caustic soda production includes multiple cooking groups 100, a heat exchanger 200, a gas generator 300, and an alkali solution tank 400. Specifically, the number of cooking groups 100 can be increased or decreased according to actual production conditions. The gas generator 300 is used to generate coal gas, which is then supplied to the furnace 110 for combustion. The alkali solution tank 400 is used to store alkali solution; this alkali solution tank 400 includes, but is not limited to, tanks, boxes, and pools created during excavation. The heat exchanger 200 includes a first connecting pipe 210 and a second connecting pipe 220. The fluids in the first connecting pipe 210 and the second connecting pipe 220 are independent of each other during flow and do not come into direct contact; heat exchange occurs only through the first connecting pipe 210 and the second connecting pipe 220. The cooking unit 100 includes at least one furnace platform 110. A cooking pot 120 is mounted on top of the furnace platform 110. An evaporation pipe 121 is connected to the top of the cooking pot 120. Multiple evaporation pipes 121 are connected to a main pipe 500, which can simultaneously collect alkaline vapor and water vapor evaporated from multiple cooking pots 120. A gas generator 300 is connected to the air inlets of multiple furnace platforms 110 through pipes. The gas generated by the gas generator 300 enters the furnace platform 110 through the air inlets and is burned inside the furnace platform 110, generating heat energy to heat the cooking pots 120. The air outlet of the furnace platform 110 is connected to the main pipe 500 through pipes, and the flue gas formed after the gas combustion enters the main pipe 500 for collection. The main pipe 500 is connected at its end to the first connecting pipe 210 of the heat exchanger 200. The first connecting pipe 210 branches into a water outlet pipe 510 and a gas outlet pipe 520. The main pipe 500 contains flue gas from coal gas combustion and alkaline vapor evaporated from the cooking pot 120. These flue gas and alkaline vapors are cooled after heat exchange in the heat exchanger 200. The gas outlet pipe 520 is connected to a chimney 521. After the coal gas and alkaline vapors are liquefied at the heat exchanger 200, the remaining dust and gas enter the chimney 521 through the gas outlet pipe 520 and are treated at the chimney 521 before being discharged into the atmosphere. The water outlet pipe 510 is connected to a collection tank 511, where the liquefied alkaline water is collected. It should be noted that the alkaline content in the alkaline water is low, therefore its corrosive effect on the pipes is limited, and general anti-corrosion treatment is sufficient. The alkali solution tank 400 is connected to at least one preheating tank 420 via a feed pipe 410. The middle part of the feed pipe 410 is connected to a second connecting pipe 220. The outlet of the preheating tank 420 is connected to the cooking pot 120. Before entering the preheating tank 420, the alkali solution preferentially passes through the heat exchanger 200. The alkali solution temperature is relatively low, while the flue gas and alkali vapor in the main pipeline 500 have higher temperatures. Therefore, during the heat exchange process at the heat exchanger 200, the temperature of the alkali solution rises. After entering the preheating tank 420, the liquid alkali can be replenished to the cooking pot 120 through the pipeline.

[0029] As can be seen from the above, in this embodiment, by setting up a gas generator 300 and introducing gas into each furnace 110, and by setting up a main pipeline 500 to comprehensively recover the flue gas, alkaline vapor, and water vapor generated in multiple cooking groups 100, only a negative pressure fan 522 needs to be set up at the end of the main pipeline 500 to "induce air" so that the gas in each furnace 110 can be burned, and at the same time, the alkaline vapor distilled from the cooking pot 120 can be extracted. This method of mixing various gases in the main pipeline 500 and then recovering them simultaneously greatly simplifies the operation process, eliminating the need for independent monitoring of each furnace 110 for operations such as coal feeding. In this embodiment, a heat exchanger 200 is also set up to exchange heat between the high-temperature flue gas and alkaline vapor in the main pipeline 500 and the low-temperature alkaline solution in the feeding pipe 410, thereby increasing the initial heat of the alkaline solution. When the alkaline solution is added to the cooking pot 120 from the preheating tank 420, the heating time can be saved due to the higher initial temperature. After the flue gas and alkaline vapor in the main pipeline 500 are cooled at the heat exchanger 200, the liquefied alkaline water can be introduced into the collection tank 511 for recycling. On the one hand, this avoids environmental pollution, and on the other hand, the alkaline water in the recycling tank can be used to replace cooling water for cooling spraying and other operations in the entire production system, saving water consumption.

[0030] In some embodiments, an air supply duct 600 is included, with its first end connected to an air intake fan 610, and its ends connected to air inlets of multiple furnace platforms 110. In this embodiment, by providing the air supply duct 600 and the air intake fan 610 to introduce air into the furnace platform 110 and conduct gas combustion in the furnace platform 110, the combustion efficiency is enhanced.

[0031] In some embodiments, a negative pressure fan 522 is connected to the exhaust pipe 520, and the exhaust end of the negative pressure fan 522 is connected to the chimney 521. In this embodiment, by setting the negative pressure fan 522 to provide a negative pressure to the main pipe 500, it is convenient to quickly extract the alkaline vapor in the cooking pot 120 and the flue gas generated by combustion in the furnace 110.

[0032] In some embodiments, a cooking group 100 includes multiple furnaces 110 connected in series. The furnace 110 at the first end is connected to a gas generator 300 via a pipe, and the furnace 110 at the last end is connected to a main pipeline 500 via a pipe. Correspondingly, multiple cooking pots 120 located in the same cooking group 100 are connected in series. The cooking pot 120 at the first end is connected to a preheating tank 420, and the cooking pot 120 at the last end is connected to the main pipeline 500 via a pipe. In this embodiment, multiple furnaces 110 and cooking pots 120 are provided on a cooking group 100, which increases the cooking efficiency of liquid alkali. Furthermore, since the multiple furnaces 110 and multiple cooking pots 120 are connected in series, independent supervision is not required, making operation simple and reducing labor.

[0033] In some embodiments, the cooking pots 120 at the end of the plurality of cooking groups 100 are connected to a discharge pipe 700, the other end of which is connected to a sheet-making machine 800. The sheet-making machine 800 is connected to a packaging machine 900 via a auger 850, and the auger 850 is connected to a main pipeline 500 via a pipe. In this embodiment, with the above configuration, the cooked liquid alkali is fed into the sheet-making machine 800 through the discharge pipe 700 for sheet making. After sheet making, it is fed into the packaging machine 900 by the auger 850 for packaging, thus effectively improving the automation level of this application.

[0034] In some embodiments, multiple cooking pots 120 located in the same cooking group 100 are connected in series via submersible pumps and pipelines. This application provides a method for connecting multiple cooking pots 120 within the same cooking group 100 in series, allowing liquid alkali in two adjacent cooking pots 120 to be conveniently pumped to another cooking pot 120 via submersible pumps and pipelines.

[0035] In some embodiments, please refer to Figure 1 And further combine Figure 2 , Figure 2 This is a schematic diagram of an embodiment of the present application with a spray device, omitting some structures and pipes. The diagram is for clarity. Figure 2 Some pipes and structures were removed. A first spray device 530 is installed inside the main pipe 500. The first spray device 530 includes multiple spray nozzles 531. A water injection pipe 532 is connected to the outside of the spray device and extends to the outside of the main pipe 500.

[0036] In this embodiment of the application, by means of the above-mentioned arrangement, a first spraying device 530 is provided in the main pipeline 500, which can spray liquid water or alkaline water condensed and recovered in the collection tank 511 to spray the main pipeline 500, thereby removing impurities in the main pipeline 500 and cooling it down.

[0037] In some embodiments, please refer to Figure 2 The collection tank 511 is connected to the water injection pipe 532 via a pump and a pipeline. In this embodiment, through the above-mentioned arrangement, the alkaline water in the collection tank 511 enters the water injection pipe 532 through the pipeline and is further sprayed out through the spray nozzle 531. Thus, the recovered alkaline water can be used to replace the cooling water, thereby achieving the purpose of saving water resources.

[0038] In some embodiments, please refer to Figure 2 A second spraying device 851 is installed inside the auger 850. Both the auger 850 and the second spraying device 851 are existing technologies. The second spraying device 851 is connected to the inside of the collection tank 511 via a pump and pipeline. The auger 850 consists of two sleeves, an inner and an outer one. The material is transferred in the inner sleeve. The second spraying device 851 is located in the outer sleeve of the auger 850 and faces the outer wall of the inner sleeve. Since the caustic soda flakes still have a high temperature after the tableting machine 800 finishes making the tablets, the above-mentioned setting is made in this application to spray the recovered alkali-containing water into the auger 850 to cool it down. After spraying, the alkali-containing water can be reintroduced into the collection tank 511 through an external pipeline.

[0039] In some embodiments, please refer to Figure 2 A spray cleaning device 111 is installed at the furnace platform 110, and the collection tank 511 is connected to the spray cleaning device 111 via a pump and pipeline. In this embodiment, the recovered alkaline water can be sprayed onto the furnace platform 110 for cleaning and cooling, which also achieves the purpose of saving water resources.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although the foregoing embodiments have provided a detailed description of this application, 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. These 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, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A comprehensive gas recovery and utilization system for caustic soda flake production, characterized in that, It includes multiple cooking groups, heat exchangers, gas generators and alkali tanks. The heat exchangers include a first connecting pipe and a second connecting pipe. The cooking groups include multiple furnaces. A cooking pot is mounted on the top of the furnace. An evaporation pipe is connected to the top of the cooking pot. Multiple evaporation pipes are connected to a main pipe. The gas generator is connected to the air inlets of multiple furnace platforms via pipelines. The air outlets of the furnace platforms are connected to the main pipeline via pipelines. The end of the main pipeline is connected to the first connecting pipeline of the heat exchanger. The end of the first connecting pipeline branches into a water outlet pipe and a gas outlet pipe. A negative pressure fan is connected to the gas outlet pipe. The air outlet of the negative pressure fan is connected to a chimney. The water outlet pipe is connected to a collection tank. The alkali tank is connected to at least one preheating tank via a feeding pipe. The middle part of the feeding pipe is connected to the second connecting pipe, and the outlet of the preheating tank is connected to the cooking pot. Multiple furnaces located in the same cooking group are connected in series. The furnace at the first end is connected to the gas generating device through a pipe, and the furnace at the end is connected to the main pipeline through a pipe. Correspondingly, multiple cooking pots located in the same cooking group are connected in series. The cooking pot at the first end is connected to the preheating tank, and the cooking pot at the end is connected to the main pipeline through a pipe.

2. The integrated gas recovery and utilization system for caustic soda flake production according to claim 1, characterized in that, It includes an air supply duct, the first end of which is connected to an air intake fan, and the second end of which is connected to the air inlets of multiple furnace platforms.

3. The integrated gas recovery and utilization system for caustic soda flake production according to claim 1, characterized in that, The cooking pots at the ends of the plurality of cooking units are connected to discharge pipes, and the other end of the discharge pipes is connected to a sheet-making machine. The sheet-making machine is connected to a packaging machine via a auger, and the auger is connected to the main pipeline via a pipe.

4. The integrated gas recovery and utilization system for caustic soda flake production according to claim 1, characterized in that, Multiple cooking pots located in the same cooking group are connected in series via submersible pumps and pipelines.

5. The integrated gas recovery and utilization system for caustic soda flake production according to claim 1, characterized in that, A first spray device is installed inside the main pipeline. The first spray device includes multiple spray nozzles. A water injection pipe is connected to the outside of the spray device and extends to the outside of the main pipeline.

6. The integrated gas recovery and utilization system for caustic soda flake production according to claim 5, characterized in that, The collection pool is connected to the water injection pipe via a pump and a pipeline.

7. The integrated gas recovery and utilization system for caustic soda flake production according to claim 3, characterized in that, The winch is equipped with a second spraying device, which is connected to the inside of the collection tank via a pump and pipes.

8. The integrated gas recovery and utilization system for caustic soda flake production according to claim 1, characterized in that, A spray cleaning device is installed at the furnace platform, and the collection tank is connected to the spray cleaning device through a pump and pipeline.

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