Coal-fired boiler ash slag waste heat recovery device

Abstract

The utility model discloses a coal-fired boiler ash residue waste heat recovery device which comprises a vertical cooling furnace and a heat exchanger which are arranged at an ash residue outlet of a coal-fired boiler, and the high-temperature air outlet end of the vertical cooling furnace is connected with the high-temperature air inlet end of the heat exchanger through a high-temperature pipeline. A low-temperature air outlet end of the heat exchanger is connected with an air inlet end of the vertical cooling furnace through a low-temperature pipeline; a steam output pipe of the heat exchanger is connected with a steam inlet end of the sulfuric acid recovery system; a high-temperature bucket elevator conveyor is arranged between a filtered ash outlet of the coal-fired boiler and the vertical cooling furnace, and a circulating fan is arranged on a low-temperature pipeline at the air inlet end of the vertical cooling furnace. Hot air of hot ash slag discharged by the boiler is recycled, hot water at about 110-130 DEG C after distillation of the sulfuric acid recovery system exchanges heat with hot flue gas to produce saturated steam at about 160 DEG C, and the saturated steam is circularly used for the distillation system of the sulfuric acid recovery system, so that energy consumption is saved, and energy consumption is reduced. Meanwhile, the operation cost of a technology for recovering sulfur resources by using the ionic liquid is also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of sulfur resource recovery by using ionic liquid, and more specifically to a coal-fired boiler ash waste heat recovery device. Background Art

[0002] Ionic liquids, also known as ionic liquids or room temperature ionic liquids, are salts composed of organic cations and organic or inorganic anions that are liquid at or near room temperature. They have many unique physical and chemical properties, such as extremely low volatility, good thermal stability, wide liquid temperature range, high electrical conductivity, and high gas solubility.

[0003] The principle of ionic liquid recovery of sulfur resources is mainly based on the efficient absorption and desorption ability of ionic liquids for sulfur-containing gases such as sulfur dioxide (SO2). During the absorption process, SO2 can react chemically with certain components in the ionic liquid to generate stable compounds. Subsequently, these compounds can be decomposed by heating or reducing pressure to release high-purity SO2 gas or other sulfur-containing compounds, thereby realizing the recovery of sulfur resources.

[0004] The technology of recovering sulfur resources by using ionic liquid consumes a large amount of saturated steam at about 160°C during operation, and the price of steam is about 180 yuan per cubic meter, which greatly increases the operating cost of recovering sulfur resources. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a coal-fired boiler ash waste heat recovery device, which reduces the operating cost of the ion liquid sulfur resource recovery technology by recovering the hot air temperature of the hot ash discharged from the coal-fired boiler.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows.

[0007] The device for recovering waste heat from ash of a coal-fired boiler comprises a vertical cooling furnace arranged at the ash outlet of the coal-fired boiler for recovering heat from high-temperature slag, and a heat exchanger for exchanging heat between high-temperature air after heat exchange and distilled hot water discharged from a sulfuric acid recovery system. The high-temperature air outlet of the vertical cooling furnace is connected to the high-temperature air inlet of the heat exchanger through a high-temperature pipeline, the low-temperature air outlet of the heat exchanger is connected to the air inlet of the vertical cooling furnace through a low-temperature pipeline, and the steam output pipe of the heat exchanger is connected to the steam inlet of the sulfuric acid recovery system; a high-temperature bucket conveyor for transporting high-temperature ash to the top of the vertical cooling furnace is arranged between the ash outlet filtered by the coal-fired boiler and the vertical cooling furnace, and a circulating fan for transporting low-temperature air after heat exchange in the heat exchanger into the vertical cooling furnace is arranged on the low-temperature pipeline at the air inlet of the vertical cooling furnace.

[0008] To further optimize the technical solution, a high-temperature dust collector for removing dust from the high-temperature air is provided on the high-temperature pipeline at the outlet end of the vertical cooling furnace.

[0009] To further optimize the technical solution, a water replenishment pipe for replenishing water is provided on the heat exchanger.

[0010] To further optimize the technical solution, a buffer ore bin is provided inside the vertical cooling furnace for the slow falling of high-temperature slag, and low-temperature air passes through the buffer ore bin for heat exchange with the high-temperature slag. A discharge port is provided at the bottom of the vertical cooling furnace for discharging the slag after heat exchange, and an electric vibrating feeder is provided at the discharge port for orderly and quantitatively discharging the slag in the furnace.

[0011] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0012] The utility model provides a coal-fired boiler ash waste heat recovery device, which recycles the hot air temperature of the hot ash discharged from the boiler, and produces saturated steam of about 160°C through heat exchange with hot flue gas at about 110°C-130°C after distillation in the sulfuric acid recovery system, which is circulated and used in the distillation system of the sulfuric acid recovery system, thereby not only saving energy consumption, but also reducing the operating cost of the ionic liquid sulfur resource recovery technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Among them: 1. Coal-fired boiler, 2. High-temperature bucket conveyor, 3. Vertical cooling furnace, 4. Circulating fan, 5. High-temperature dust collector, 6. Distilled hot water, 7. Heat exchanger, 8. Steam output pipe, 9. Water supply pipe. DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] A coal-fired boiler ash waste heat recovery device, combined with Figure 1 As shown, it includes a coal-fired boiler 1, a high-temperature bucket conveyor 2, a vertical cooling furnace 3 and a heat exchanger 7. The high-temperature bucket conveyor 2 is used to convey the high-temperature ash discharged from the coal-fired boiler 1 to the vertical cooling furnace 3. The vertical cooling furnace 3 is used to recover the heat of the high-temperature slag. The heat exchanger 7 is used to exchange the high-temperature air after heat exchange with the distilled hot water 6 discharged from the sulfuric acid recovery system, and output high-temperature steam for use by the sulfuric acid recovery system.

[0017] The high-temperature air outlet end of the vertical cooling furnace 3 is connected to the high-temperature air inlet end of the heat exchanger 7 through a high-temperature pipe, and the low-temperature air outlet end of the heat exchanger 7 is connected to the air inlet end of the vertical cooling furnace 3 through a low-temperature pipe. The steam output pipe 8 of the heat exchanger 7 is connected to the steam inlet end of the sulfuric acid recovery system. A water supply pipe 9 is provided on the heat exchanger 7 for water supply.

[0018] The high-temperature bucket conveyor 2 is arranged at the ash outlet end of the coal-fired boiler 1. The high-temperature ash discharged from the coal-fired boiler is discharged into the high-temperature bucket conveyor 2 through the chute. The high-temperature bucket conveyor 2 lifts the hot material to the top of the vertical cooling furnace 3 and enters the vertical cooling furnace 3 from the top.

[0019] A circulating fan 4 is provided on the low-temperature pipe at the air inlet end of the vertical cooling furnace 3 for conveying the low-temperature air after heat exchange in the heat exchanger 7 into the vertical cooling furnace 3 .

[0020] A buffer ore bin is provided inside the vertical cooling furnace 3 for allowing the high-temperature slag to fall slowly. The low-temperature air passes through the buffer ore bin to exchange heat with the falling high-temperature slag. A plurality of discharge ports are provided at the bottom of the vertical cooling furnace 3. An electric vibrating feeder is provided at the discharge port. The slag after heat exchange and cooling is discharged in an orderly and quantitative manner through the electric vibrating feeder at the discharge port. The discharged material is merged into the discharge bin at the lower part and then transported out through the conveyor below.

[0021] The vertical cooler 3 adopts the air medium circulation cooling method. The circulating fan sends the low-temperature air discharged from the heat exchanger through the air duct in the middle of the vertical cooler to the inner and outer rings of the cooling section of the vertical cooling furnace. The air flows from bottom to top through the buffer ore layer under the action of positive pressure, and then is discharged from the air outlet on the upper side of the vertical cooling furnace. The discharged hot air temperature is about 700°C. The material is cooled to below 160°C and discharged from the discharge port at the bottom.

[0022] A high-temperature dust collector 5 is provided on the high-temperature pipe at the outlet of the vertical cooling furnace 3 to remove dust from the high-temperature air. The high-temperature flue gas after dust removal enters the heat exchanger to heat the circulating hot water discharged from the sulfuric acid recovery system. The air temperature after heat exchange is reduced to about 130°C. The cooled air returns to the circulating fan and enters the vertical cooler to repeatedly cool the high-temperature slag.

[0023] The circulating hot water after distillation through the sulfuric acid recovery system is about 110℃--130℃. The discharged hot air temperature is about 700℃, which heats the circulating distillation hot water to produce saturated steam at about 160℃, which is used for recycling in the sulfuric acid recovery distillation system.

Claims

1. A coal-fired boiler ash waste heat recovery device, characterized in that: The invention comprises a vertical cooling furnace (3) arranged at the ash outlet of a coal-fired boiler (1) for recovering heat from high-temperature slag, and a heat exchanger (7) for exchanging heat between high-temperature air after heat exchange and distilled hot water (6) discharged from a sulfuric acid recovery system. The high-temperature air outlet of the vertical cooling furnace (3) is connected to the high-temperature air inlet of the heat exchanger (7) through a high-temperature pipeline, the low-temperature air outlet of the heat exchanger (7) is connected to the air inlet of the vertical cooling furnace (3) through a low-temperature pipeline, and the steam output pipe (8) of the heat exchanger (7) is connected to the steam inlet of the sulfuric acid recovery system. A high-temperature bucket conveyor (2) for transporting high-temperature ash to the top of the vertical cooling furnace (3) is arranged between the ash outlet of the coal-fired boiler (1) and the vertical cooling furnace (3), and a circulating fan (4) for transporting low-temperature air after heat exchange in the heat exchanger (7) into the vertical cooling furnace (3) is arranged on the low-temperature pipeline at the air inlet of the vertical cooling furnace (3).

2. The coal-fired boiler ash waste heat recovery device according to claim 1, characterized in that: A high-temperature dust collector (5) for removing dust from the high-temperature air is provided on the high-temperature pipeline at the air outlet end of the vertical cooling furnace (3).

3. The coal-fired boiler ash waste heat recovery device according to claim 1, characterized in that: The heat exchanger (7) is provided with a water replenishment pipe (9) for replenishing water.

4. The coal-fired boiler ash waste heat recovery device according to claim 1, characterized in that: The vertical cooling furnace (3) is provided with a buffer ore bin for the slow fall of high-temperature slag inside, and low-temperature air passes through the buffer ore bin to exchange heat with the high-temperature slag. The bottom of the vertical cooling furnace (3) is provided with a discharge port for discharging the slag after the heat exchange, and an electric vibrating feeder is provided at the discharge port for discharging the slag in the furnace in an orderly and quantitative manner.

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