Furnace gas waste heat recycling system of calcium carbide furnace

Abstract

The utility model discloses a furnace gas waste heat recycling system of a calcium carbide furnace. The furnace gas waste heat recycling system comprises a vaporization flue, a first steam pocket, a waste heat boiler, a dust remover, a first economizer, a softened water tank and a deaerator, an exhaust port of the calcium carbide furnace is communicated with an air inlet of the waste heat boiler through a vaporization flue, an exhaust port of the waste heat boiler is communicated with an air inlet of the dust remover through a first pipeline, an exhaust port of the dust remover is communicated with an air inlet of the first economizer, and an exhaust pipeline is communicated to an exhaust port of the first economizer; an outlet of the softened water tank is communicated with an inlet of a deaerator, an outlet of the deaerator is communicated with a water inlet of a first steam pocket through a second pipeline, the middle of the second pipeline is communicated with a water inlet of a first economizer, and a water outlet of the first economizer is communicated with a water inlet of a second economizer of the waste heat boiler; a water outlet of the first steam pocket is communicated with a water inlet of the vaporization flue through a third pipeline, a circulating water pump is arranged on the third pipeline, and a steam outlet of the vaporization flue is communicated with a gas inlet of the first steam pocket.

Description

Technical field:

[0001] The utility model relates to the technical field of high-temperature furnace gas waste heat recovery, and in particular to a furnace gas waste heat recovery and utilization system of a calcium carbide furnace. Background technology:

[0002] Calcium carbide is one of the basic raw materials for the organic synthetic chemical industry. It is generally produced by electrothermal method, that is, quicklime and carbon-containing raw materials are melted by electric arc in a closed calcium carbide furnace to generate calcium carbide. In the process of calcium carbide production, a large amount of high-temperature furnace gas is produced as a by-product. Under normal working conditions, the furnace gas volume is about 4500-5500Nm 3 / h, the furnace gas temperature is about 1000℃, and the dust content in the furnace gas is relatively high, about 100g / Nm 3 The above, the dust particles are fine, the structure is loose, and it has a certain degree of adhesion; in addition, there is a certain amount of tar in the furnace gas.

[0003] At present, the method for treating a large amount of high-temperature furnace gas is: the high-temperature furnace gas passes through a water-cooled flue, a cyclone dust collector, a bag dust collector, and an induced draft fan in sequence and is discharged from the chimney; the existing problem is: when using a traditional water-cooled flue to cool the high-temperature furnace gas, about 50% of the heat of the furnace gas is not recycled, there is a problem of energy waste, and it will cause thermal pollution to the environment, which is not conducive to environmental protection. Utility model content:

[0004] The utility model aims to provide a system for recovering waste heat from furnace gas of a calcium carbide furnace.

[0005] The purpose of the utility model is implemented by the following technical scheme: a furnace gas waste heat recovery and utilization system of calcium carbide furnace, which includes a vaporization flue, a first steam drum, a waste heat boiler, a dust collector, a first economizer, a soft water tank and a deaerator;

[0006] The exhaust port of the calcium carbide furnace is connected to the air inlet of the waste heat boiler through the vaporization flue, the exhaust port of the waste heat boiler is connected to the air inlet of the dust collector through a first pipeline, a rough air fan is provided on the first pipeline, the exhaust port of the dust collector is connected to the air inlet of the first economizer, the exhaust port of the first economizer is connected to an exhaust pipeline, and a clean air fan is provided on the exhaust pipeline;

[0007] The outlet of the soft water tank is connected to the inlet of the deaerator, the outlet of the deaerator is connected to the water inlet of the first steam drum through a second pipeline, the water outlet of the first steam drum is connected to the water inlet of the vaporization flue through a third pipeline, a circulating water pump is provided on the third pipeline, the steam outlet of the vaporization flue is connected to the air inlet of the first steam drum; the middle part of the second pipeline is connected to the water inlet of the first economizer, and the water outlet of the first economizer is connected to the water inlet of the second economizer of the waste heat boiler.

[0008] Preferably, the waste heat boiler comprises a first flue, a second flue, a transition flue and a second steam drum; the first flue and the second flue are arranged vertically in parallel, and the top of the first flue is connected to the top of the second flue through the transition flue; ash discharge ports are respectively provided at the bottom of the first flue and the bottom of the second flue, an air inlet is provided on the bottom side wall of the first flue, a first evaporator is provided in the first flue, the second economizer and the second evaporator are provided from bottom to top in the second flue, and an exhaust port is provided on the bottom side wall of the second flue;

[0009] The water outlet of the second economizer is connected to the water inlet of the second steam drum through a water inlet pipe, the water outlet of the second steam drum is connected to the water inlets of the first evaporator and the second evaporator through a downcomer respectively, the steam outlets of the first evaporator and the second evaporator are connected to the air inlet of the second steam drum through a riser respectively; the exhaust port of the second steam drum is connected to a steam exhaust pipeline.

[0010] Preferably, a plurality of shock wave soot blowers are respectively provided at intervals on the first flue and the second flue of the waste heat boiler.

[0011] Preferably, star-shaped ash discharge valves are installed on the ash discharge ports of the first flue and the second flue of the waste heat boiler and the dust collector, respectively, and the outlet of each star-shaped ash discharge valve is connected to the ash conveying pipeline, and the outlet of the ash conveying pipeline is connected to the inlet of the ash bin.

[0012] The utility model has the advantages that: the utility model conveys the deoxygenated soft water to the first steam drum and the first economizer through a water pump, the soft water in the first steam drum enters the vaporization flue, exchanges heat with the high-temperature furnace gas, and the soft water cools the high-temperature furnace gas in the vaporization flue in a vaporized manner and absorbs heat, thus completing the first waste heat absorption of the high-temperature furnace gas; the soft water in the first economizer enters the second steam drum through the second economizer, enters the first evaporator and the second evaporator through the downcomer, and at the same time, the furnace gas discharged from the vaporization flue enters the first flue from the air inlet of the waste heat boiler, contacts with the first evaporator for heat exchange, and after the furnace gas completes the heat exchange with the first evaporator, passes through the transition flue The furnace gas enters the second flue in the form of a swirl flow, contacts and exchanges heat with the second evaporator and the second economizer in turn, and then is discharged from the exhaust port of the waste heat boiler through the second flue, thus completing the second waste heat absorption of the high-temperature furnace gas; the furnace gas discharged from the waste heat boiler enters the dust collector for dust removal, and then enters the shell side of the first economizer, contacts and exchanges heat with the soft water in the tube side of the first economizer, and then is discharged through the exhaust pipeline, thus completing the third waste heat absorption of the high-temperature furnace gas; through the above three absorptions of the heat of the high-temperature furnace gas, more than 90% of the waste heat of the furnace gas is recycled, which greatly reduces energy waste and reduces the thermal pollution to the environment. Description of the drawings:

[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creativity and labor.

[0014] Figure 1 It is a structural schematic diagram of the utility model.

[0015] Figure 2 It is a schematic diagram of the internal structure of the waste heat boiler.

[0016] The components in the accompanying drawings are marked as follows: calcium carbide furnace 1, vaporization flue 2, waste heat boiler 3, first flue 3.1, second flue 3.2, transition flue 3.3, second steam drum 3.4, first evaporator 3.5, second economizer 3.6, second evaporator 3.7, first steam drum 4, dust collector 5, first economizer 6, soft water tank 7, deaerator 8, first pipeline 9, rough air fan 10, clean air fan 11, second pipeline 12, third pipeline 13, circulating water pump 14, shock wave soot blower 15, star-shaped ash unloading valve 16, ash conveying pipeline 17, ash bin 18. Specific implementation method:

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] like Figure 1-Figure 2 As shown, a system for recovering waste heat from furnace gas of a calcium carbide furnace comprises a vaporization flue 2, a waste heat boiler 3, a first steam drum 4, a dust collector 5, a first economizer 6, a soft water tank 7 and a deaerator 8;

[0019] The exhaust port of the calcium carbide furnace 1 is connected with the air inlet of the waste heat boiler 3 through the vaporization flue 2. The vaporization flue 2 and the first steam drum 4 are used together to absorb the high-temperature furnace gas overflowing from the exhaust port of the calcium carbide furnace 1. The waste heat boiler 3 can further absorb the waste heat of the furnace gas of the calcium carbide furnace 1 to produce steam for production, life and power generation. The waste heat boiler 3 includes a first flue 3.1, a second flue 3.2, a transition flue 3.3 and a second steam drum 3.4; the first flue 3.1 and the second flue 3.2 are arranged vertically in parallel, and the top of the first flue 3.1 is connected with the top of the second flue 3.2 through the transition flue 3.3; the first flue An air inlet is provided on the bottom side wall of 3.1, a first evaporator 3.5 is provided in the first flue 3.1, a second economizer 3.6 and a second evaporator 3.7 are provided from bottom to top in the second flue 3.2, and an exhaust port is provided on the bottom side wall of the second flue 3.2. The furnace gas discharged from the vaporization flue 2 enters the first flue 3.1 from the air inlet of the waste heat boiler 3, first contacts and exchanges heat with the first evaporator 3.5, then enters the second flue 3.2 through the transition flue 3.3, and then contacts and exchanges heat with the second evaporator 3.7 and the second economizer 3.6 in sequence, and then the furnace gas is discharged from the exhaust port of the waste heat boiler 3 through the second flue 3.2;

[0020] The exhaust port of the waste heat boiler 3 is connected with the air inlet of the dust collector 5 through the first pipeline 9, and a rough air fan 10 is arranged on the first pipeline 9. The exhaust port of the dust collector 5 is connected with the air inlet of the first economizer 6 through a pipeline. The first economizer 6 continues to absorb the heat of the high-temperature furnace gas through soft water, reduces the temperature of the furnace gas, and saves energy. The exhaust port of the first economizer 6 is connected with an exhaust pipeline, and a clean air fan 11 is arranged on the exhaust pipeline. Under the action of the rough air fan 10, the furnace gas discharged from the waste heat boiler 3 enters the dust collector 5 through the first pipeline 9 for dust removal. The furnace gas after dust removal enters the shell side of the first economizer 6 through the pipeline. The soft water in the tube side of the first economizer 6 absorbs the waste heat of the furnace gas. The furnace gas after cooling is discharged through the exhaust pipeline under the action of the clean air fan 11.

[0021] The outlet of the soft water tank 7 is connected to the inlet of the deaerator 8 through a pipeline, and the outlet of the deaerator 8 is connected to the water inlet of the first steam drum 4 through a second pipeline 12. A water pump is provided on the second pipeline 12. The water in the soft water tank 7 enters the deaerator 8 through the pipeline for deoxygenation. After deoxygenation, under the action of the water pump, the soft water enters the first steam drum 4 through the second pipeline 12 to complete the water replenishment of the first steam drum 4. The water outlet of the first steam drum 4 is connected to the water inlet of the vaporization flue 2 through a third pipeline 13. A circulating water pump 14 is provided on the third pipeline 13. The steam outlet of the vaporization flue 2 is connected to the air inlet of the first steam drum 4 through a pipeline. The vaporization flue 2 is used in conjunction with the first steam drum 4. The soft water cools the high-temperature furnace gas in the vaporization flue 2 in a vaporized manner and absorbs heat, thereby generating steam. In principle, it can be regarded as a specific boiler that can recover a large amount of heat energy from the high-temperature furnace gas.

[0022] The middle part of the second pipeline 12 is connected to the water inlet of the first economizer 6 through a pipeline, and the water outlet of the first economizer 6 is connected to the water inlet of the second economizer 3.6 through a fourth pipeline. A water pump is provided on the fourth pipeline. The water outlet of the second economizer 3.6 is connected to the water inlet of the second steam drum 3.4 through a water inlet pipe. Under the action of the water pump, soft water enters the first economizer 6 through the pipeline, absorbs the waste heat of the furnace gas, and finally enters the second steam drum 3.4 to complete the water replenishment of the second steam drum 3.4. The water outlet of the second steam drum 3.4 is connected to the water inlet of the second evaporator 3.7 and the first evaporator 3.5 through a downcomer respectively. The steam outlets of the second evaporator 3.7 and the first evaporator 3.5 are connected to the air inlet of the second steam drum 3.4 through a riser respectively. The exhaust port of the second steam drum 3.4 is connected to a steam discharge pipeline;

[0023] A plurality of shock wave soot blowers 15 are arranged at intervals on the first flue 3.1 and the second flue 3.2. When the furnace gas enters the first flue 3.1, the transition flue 3.3 and the second flue 3.2, the shock wave soot blowers 15 are used for soot blowing. The furnace gas flows in a rotating manner after the soot blowing, and contacts and exchanges heat with the first evaporator 3.5, the second evaporator 3.7 and the second economizer 3.6. The contact between the furnace gas and the heating surface is not horizontal flushing, but contacts the heating surface in the form of swirl, which can ensure a certain heat exchange intensity and prevent dust from being easily accumulated in the first evaporator 3.5, the second evaporator 3.7 and the second economizer 3.6. On the surface, ash discharge ports are respectively provided at the bottom of the first flue 3.1 and the bottom of the second flue 3.2. Star-shaped ash discharge valves 16 are respectively installed on the ash discharge ports of the first flue 3.1 and the second flue 3.2 of the waste heat boiler 3 and the ash discharge port of the dust collector 5. The outlets of each star-shaped ash discharge valve 16 are connected with the ash conveying pipeline 17. The outlet of the ash conveying pipeline 17 is connected with the inlet of the ash bin 18. During the soot blowing process of the shock wave soot blower 15, dust separation can be achieved. The ash is discharged through the ash discharge ports of the first flue 3.1 and the second flue 3.2, enters the ash conveying pipeline 17 through the star-shaped ash discharge valve 16, and finally enters the ash bin 18 through the ash conveying pipeline 17.

[0024] Working process: the water in the soft water tank 7 enters the deaerator 8 through the pipeline for deoxygenation. After deoxygenation, the soft water enters the first steam drum 4 through the second pipeline 12 under the action of the water pump, and completes the water replenishment of the first steam drum 4. At the same time, the soft water enters the first economizer 6 through the pipeline, and then enters the second steam drum 3.4 through the second economizer 3.6, and completes the water replenishment of the second steam drum 3.4.

[0025] During the water replenishment process, the high-temperature furnace gas of the calcium carbide furnace 1 enters the vaporization flue 2, and the water in the first steam drum 4 enters the vaporization flue 2 to exchange heat with the high-temperature furnace gas. The soft water cools the high-temperature furnace gas in the vaporization flue 2 and absorbs heat in a vaporized manner. At this point, the first waste heat absorption of the high-temperature furnace gas is completed;

[0026] The furnace gas discharged from the vaporization flue 2 enters the first flue 3.1 from the air inlet of the waste heat boiler 3, and contacts with the first evaporator 3.5 for heat exchange. After the furnace gas completes the heat exchange with the first evaporator 3.5, it enters the second flue 3.2 in the form of a swirl through the transition flue 3.3, contacts with the second evaporator 3.7 and the second economizer 3.6 in turn, and is discharged from the exhaust port of the waste heat boiler 3 through the second flue 3.2; and the soft water in the second steam drum 3.4 enters the first evaporator 3.5 and the second evaporator 3.7 through the downcomer, and contacts with the high-temperature furnace gas for heat exchange. The soft water in the first evaporator 3.5 and the second evaporator 3.7 absorbs heat and becomes steam, which is transported to the application site through the steam discharge pipeline of the second steam drum 3.4. At this point, the second waste heat absorption of the high-temperature furnace gas is completed;

[0027] Under the action of the rough air blower 10, the furnace gas discharged from the waste heat boiler 3 enters the dust collector 5 through the first pipeline 9 for dust removal. The dust-removed furnace gas enters the shell side of the first economizer 6 through the pipeline, and after heat exchange with the soft water in the tube side of the first economizer 6, it is discharged through the exhaust pipeline under the action of the clean air blower 11. At this point, the third waste heat absorption of the high-temperature furnace gas is completed;

[0028] After the furnace gas enters the first flue 3.1, the transition flue 3.3 and the second flue 3.2 from the air inlet of the waste heat boiler 3, it is blown by the shock wave soot blower 15. During the soot blowing process of the shock wave soot blower 15, dust separation can be achieved, and the ash is discharged through the ash discharge ports of the first flue 3.1 and the second flue 3.2, enters the ash conveying pipeline 17 through the star-shaped ash discharge valve 16, and finally enters the ash bin 18 through the ash conveying pipeline 17.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for recovering waste heat from furnace gas of a calcium carbide furnace, characterized in that: It includes a vaporization flue, a first steam drum, a waste heat boiler, a dust collector, a first economizer, a soft water tank and a deaerator; The exhaust port of the calcium carbide furnace is connected to the air inlet of the waste heat boiler through the vaporization flue, the exhaust port of the waste heat boiler is connected to the air inlet of the dust collector through a first pipeline, a rough air fan is provided on the first pipeline, the exhaust port of the dust collector is connected to the air inlet of the first economizer, the exhaust port of the first economizer is connected to an exhaust pipeline, and a clean air fan is provided on the exhaust pipeline; The outlet of the soft water tank is connected to the inlet of the deaerator, the outlet of the deaerator is connected to the water inlet of the first steam drum through a second pipeline, the water outlet of the first steam drum is connected to the water inlet of the vaporization flue through a third pipeline, a circulating water pump is provided on the third pipeline, the steam outlet of the vaporization flue is connected to the air inlet of the first steam drum; the middle part of the second pipeline is connected to the water inlet of the first economizer, and the water outlet of the first economizer is connected to the water inlet of the second economizer of the waste heat boiler.

2. The system for recovering waste heat from furnace gas of a calcium carbide furnace according to claim 1, characterized in that: The waste heat boiler comprises a first flue, a second flue, a transition flue and a second steam drum; the first flue and the second flue are arranged vertically in parallel, and the top of the first flue is connected with the top of the second flue through the transition flue; the bottom of the first flue and the bottom of the second flue are respectively provided with ash discharge ports, the bottom side wall of the first flue is provided with an air inlet, a first evaporator is provided in the first flue, the second economizer and the second evaporator are provided from bottom to top in the second flue, and an exhaust port is provided on the bottom side wall of the second flue; The water outlet of the second economizer is connected to the water inlet of the second steam drum through a water inlet pipe, the water outlet of the second steam drum is connected to the water inlets of the first evaporator and the second evaporator through a downcomer respectively, the steam outlets of the first evaporator and the second evaporator are connected to the air inlet of the second steam drum through a riser respectively; the exhaust port of the second steam drum is connected to a steam exhaust pipeline.

3. The system for recovering waste heat from furnace gas of a calcium carbide furnace according to claim 2, characterized in that: A plurality of shock wave soot blowers are respectively arranged at intervals on the first flue and the second flue of the waste heat boiler.

4. A system for recovering waste heat from furnace gas of a calcium carbide furnace according to claim 2 or 3, characterized in that: The ash discharge ports of the first flue and the second flue of the waste heat boiler and the dust collector are respectively installed with star-shaped ash discharge valves, and the outlets of the star-shaped ash discharge valves are connected to the ash conveying pipeline, and the outlets of the ash conveying pipelines are connected to the inlet of the ash bin.

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