Cooling and cleaning system

Abstract

This cooling and cleaning system comprises: a cooling and cleaning device for cooling and cleaning a reformed gas discharged from a high-temperature reaction furnace by spraying cooling water onto the reformed gas; and a water seal tank comprising a hollow cylindrical body, a tapered part inclining downward from the inner surface of the body toward the center and having a hole at the center, and a hollow cylindrical internal pipe which is connected to the tapered part, has a hollow portion continuous with the hole of the tapered part, and is disposed inside the body, wherein the reformed gas that has flowed out of the cooling and cleaning device and the cooling water flow to the upper side of the tapered part. The cooling water flows spirally at the tapered part and then flows into the internal pipe.

Description

Cooling and Cleaning System

[0001] The present invention relates to a cooling wash system.

[0002] In gasification and reforming systems, which gasify waste and then reform the resulting gas to recover the reformed gas, the waste is gasified and melted in a high-temperature reactor, and the resulting gas is reformed in the freeboard section of the high-temperature reactor to produce the reformed gas. This reformed gas is cooled and washed with cooling water in a quenching and washing device, where water-soluble components, carbon particles, etc. are removed. The reformed gas from which the water-soluble components and carbon particles have been removed is purified in a gas purification device and recovered as purified gas.

[0003] In this quenching and scrubbing apparatus, the cooling water falls, containing carbon particles and other contaminants. When the cooling water reaches the surface of the cooling water stored in the quenching and scrubbing apparatus, the reformed gas is drawn into the water, generating bubbles of reformed gas. The carbon particles contained in the cooling water adhere to the surface of the bubbles, and the bubbles with the attached carbon particles rise to the surface and collect. These bubbles with attached carbon particles are called scum. If a large amount of scum is generated, it can clog the piping from the quenching and scrubbing apparatus to the downstream process, hindering the continuous operation of the equipment.

[0004] Therefore, one example of an invention for suppressing the generation of scum is the device disclosed in Patent Document 1. In the device disclosed in Patent Document 1, the gas temperature at the outlet of the freeboard section is set to 1000°C or higher, the moisture content in the reformed gas is set to 33% by volume or higher, and the residence time of the reformed gas in the freeboard section is set to 1.5 seconds or longer. By increasing the moisture content in the reformed gas, the solids concentration in the cooling water is reduced. Also, by setting the gas temperature at the outlet of the freeboard section to 1000°C or higher and the residence time of the reformed gas in the freeboard section to 1.5 seconds or longer, carbon particulates are converted to carbon monoxide, reducing the content of carbon particulates in the reformed gas. As a result, fewer carbon particulates are contained in the water in the quenching and scrubbing device, and the generation of scum is suppressed.

[0005] Japanese Patent Application Laid-Open No. 2008-106117

[0006] In the device disclosed in Patent Document 1, in order to achieve predetermined conditions for the gas temperature, moisture content of the gas, and gas residence time in the freeboard section, the plastic content in the waste is set to a predetermined ratio, a predetermined ratio of water is added to the waste, and the amount of oxygen in the freeboard section is adjusted to adjust the gas temperature and moisture content, and therefore a process for adjusting the ratio of plastic in the waste and the moisture content in the waste is required during operation.

[0007] The present invention has been made in view of the above, and has as its object to suppress the accumulation of scum without adjusting waste materials.

[0008] A cooling and cleaning system according to one aspect of the present invention comprises: a cooling and cleaning device that injects cooling water onto reformed gas discharged from a high-temperature reactor to cool and clean the reformed gas; a hollow, cylindrical main body; a tapered section that slopes downward from the inner surface of the main body toward the center and has a hole in the center; a hollow, cylindrical internal piping that is connected to the tapered section and communicates with the hole in the tapered section and is disposed inside the main body; and a water-sealed tank into which the reformed gas and the cooling water flowing out of the cooling and cleaning device flow above the tapered section, and the cooling water flows in a spiral shape in the tapered section and into the internal piping.

[0009] In the present invention, the reformed gas that flows into the upper side of the tapered portion together with the cooling water from the high-temperature reactor may flow from the space above the tapered portion to an acid washing device that washes the reformed gas with acid.

[0010] In addition, in the present invention, the cooling water that flows into the internal pipe may be configured to flow out from the lower end of the internal pipe, rise between the main body and the internal pipe, and flow into a settling tank that separates solids contained in the cooling water.

[0011] In addition, in the present invention, the cooling and washing device may have a nozzle for spraying the cooling water, and the distance from the water surface of the cooling water stored inside the cooling and washing device to the nozzle may be a distance that cools the reformed gas to 100°C or less.

[0012] In the present invention, the inner diameter of the internal pipe may be equal to or greater than half the inner diameter of the main body.

[0013] According to the present invention, it is possible to suppress the accumulation of scum without adjusting the waste.

[0014] Fig. 1 is a diagram showing the configuration of a waste treatment device according to an embodiment. Fig. 2 is a schematic diagram showing the inside of a cooling washing device and a gas-water sealed tank according to an embodiment. Fig. 3 is a cross-sectional view taken along line AA in Fig. 2.

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. It should be noted that the drawings are schematic and that the dimensional relationships between elements may differ from the actual ones.

[0016] 1 is a diagram showing the configuration of a waste treatment device 1 according to an embodiment of the present invention. The waste treatment device 1 is an incineration facility that uses a gasification and reforming method in which waste W is combusted and pyrolyzed to gasify it, and this gas is then reformed at high temperatures to recover it as fuel gas or chemical raw material gas.

[0017] The pit 10 is a facility for storing waste W dumped from a vehicle (not shown). The crane 11 is a crane that stirs and moves the waste W stored in the pit 10. The waste W stored in the pit 10 is grabbed by the crane 11 and dumped into the dump section 13.

[0018] The input section 13 has an opening / closing door 15. The opening / closing door 15 opens and closes an input port 201a (described later) by a drive device (not shown). When the opening / closing door 15 is open, the waste W is dropped from the crane 11 and passes downward, and when closed, the waste W is blocked.

[0019] The compression device 20 is a device that compresses the waste W and is provided below the input section 13. The compression device 20 has a cylindrical casing 201. The compression device 20 also has a piston 202 that reciprocates inside the casing 201 and a plate-shaped opening / closing section 203 that moves up and down to open and close the cylindrical opening of the casing 201. The casing 201 is provided with an input port 201a through which the waste W is input. The waste W input into the input section 13 by the crane 11 enters the inside of the casing 201 through the input port 201a. In the compression device 20, the piston 202 moves toward the opening / closing section 203 while the opening / closing section 203 is lowered to block the opening of the casing 201. The waste W is sandwiched between the piston 202 and the opening / closing section 203 as it moves toward the opening / closing section 203, compressed, and molded into a waste block P.

[0020] A heating furnace 70 is provided between the compression device 20 and the high-temperature reactor 30. One end of the heating furnace 70 is connected to the compression device 20 and the other end is connected to the high-temperature reactor 30. The heating furnace 70 is heated externally and heats the waste blocks P supplied from the compression device 20 internally. The heated waste blocks P are thermally decomposed by the heat, which causes moisture to evaporate and degass the waste blocks P, generating volatile matter. The heated waste blocks P are further thermally decomposed by radiant heat from the high-temperature reactor 30. The waste blocks P heated in the heating furnace 70 are pushed by the waste blocks P sent from the compression device 20 and sent to the high-temperature reactor 30. The upper wall of the heating furnace 70 is inclined upward toward the high-temperature reactor 30, creating a wide internal space. Because the internal space widens toward the high-temperature reactor 30, a space is formed above the waste blocks P, allowing moisture evaporated from the waste blocks P to be released.

[0021] The high-temperature reactor 30 is a positive-pressure furnace and includes a vertically disposed reaction section 31 and a horizontally disposed homogenization section 32. The waste W supplied to the high-temperature reactor 30 is deposited in the lower part of the reaction section 31. High-concentration oxygen is blown into the lower part of the reaction section 31 from an oxygen supply section 40 that generates oxygen. This high-concentration oxygen reacts with carbon in the pyrolyzed waste W, melting the metal and inorganic components in the waste W. This melt flows from the reaction section 31 to the homogenization section 32, where trace amounts of carbon are gasified. In the homogenization section 32, the metal melt (metal) accumulates below the inorganic melt (slag) due to its high density. The metal melt and inorganic melt continuously flow down to the water granulation section 60, where they are cooled and solidified. The cooled and solidified mixture is separated into slag and metal by a magnetic separator.

[0022] The gas generated in the high-temperature reactor 30 and the gas generated in the heating furnace 70 are retained in the upper part of the reaction section 31 at approximately 1200°C for 2 seconds or more. Under these conditions, the tar components and dioxins and their precursors in the gas are completely decomposed, and H ２ , CO, CO ２ , H ２ The reformed gas is reformed to a reformed gas containing O as the main component.

[0023] One end of a gas duct 33 that discharges the reformed gas generated in the reaction section 31 to the outside of the high-temperature reaction furnace 30 is connected to the upper end of the reaction section 31. The other end of the gas duct 33 is connected to a cooling and cleaning device 50 that cools and cleans the reformed gas, and the reformed gas that has passed through the gas duct 33 flows to the cooling and cleaning system 2.

[0024] The cooling and washing system 2 includes a cooling and washing device 50 and a gas-water seal tank 59. FIG. 2 is a schematic diagram of the interior of the cooling and washing device 50 and the gas-water seal tank 59. The cooling and washing device 50 has an injection nozzle 501 that injects cooling and washing water 80. The shorter the distance from the water surface of the cooling and washing water 80 stored inside the cooling and washing device 50 to the injection nozzle 501, the better, as long as the reformed gas can be cooled to 100°C or less. The cooling and washing device 50 injects the cooling and washing water 80 supplied from the heat exchanger 53 from the injection nozzle 501 to cool the reformed gas. The cooling and washing device 50 also removes and cleans water-soluble components, dust, carbon particles, and the like from the reformed gas using the cooling and washing water 80. The cooling and washing water 80 used to cool and wash the reformed gas in the cooling and washing device 50 and the cleaned reformed gas flow into the gas-water seal tank 59.

[0025] The gas-water sealed vessel 59 includes a hollow cylindrical main body 591, a tapered section 593 that slopes downward toward the center at the upper part of the inner surface of the main body 591 and has a central hole, and a hollow cylindrical internal pipe 594 whose upper end is connected to the lower end of the tapered section 593 and whose hollow section is connected to the hole in the tapered section 593. The inner diameter of the internal pipe 594 is preferably larger than half the inner diameter of the main body 591. Inside the main body 591, an inlet chamber 592 is provided above the tapered section 593. A pipe 597 connected to the cooling and cleaning device 50 is connected to this inlet chamber 592, and the reformed gas and cooling and cleaning water 80 flow in from the cooling and cleaning device 50 through the pipe 597. A gas duct 595 connected to the acid cleaning device 51 is connected above the inlet chamber 592. The reformed gas that has flowed into the inlet chamber 592 flows to the acid washing device 51 through a gas duct 595 as shown by the dashed arrow in FIG.

[0026] FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. In FIGS. 2 and 3, the flow of cooling cleaning water 80 is indicated by solid arrows. Pipe 597 is connected to main body 591 along a tangent to main body 591 when viewed from above. The cooling cleaning water 80 that flows into inlet chamber 592 from pipe 597 flows in a spiral shape in tapered section 593 as shown by the arrow in FIG. 3 and flows into internal pipe 594. Pipe 596, which is connected to settling tank 52, is also connected to main body 591. The cooling cleaning water 80 that flows into internal pipe 594 flows down internal pipe 594 and is discharged from the lower end of internal pipe 594 as shown in FIG. 2. The cooling cleaning water 80 discharged from internal pipe 594 rises between the inner surface of main body 591 and the outer surface of internal pipe 594 and flows through pipe 596 to settling tank 52.

[0027] The settling tank 52 stores the cooling cleaning water 80 flowing in from the pipe 596 and separates solids contained in the cooling cleaning water 80 by settling. The cooling cleaning water 80 from which the solids have been separated in the settling tank 52 is sent to the heat exchanger 53. The heat exchanger 53 cools the cooling cleaning water 80 sent from the settling tank 52 and supplies the cooled cooling cleaning water 80 to the cooling cleaning device 50. In addition, a portion of the cooling cleaning water 80 from which the solids have been separated in the settling tank 52 is sent to the water treatment device 57.

[0028] The water treatment device 57 removes heavy metal ions and calcium as metal hydroxides and calcium carbonate from the cooling and washing water 80 sent thereto. The cooling and washing water 80 treated by the water treatment device 57 is sent to the salt production device 58. The salt production device 58 removes mixed salts from the cooling and washing water 80 sent thereto from the water treatment device 57. The water from which the mixed salts have been removed is reused as the cooling and washing water 80, for example.

[0029] The acid washing device 51 washes the reformed gas flowing from the gas-water sealed tank 59 with acid to dissolve and remove heavy metals. The reformed gas washed in the acid washing device 51 is sent to the alkali washing device .

[0030] The alkaline washing device 54 washes the reformed gas washed in the acid washing device 51 with alkaline washing water to remove hydrogen chloride and hydrogen fluoride. The reformed gas washed in the alkaline washing device 54 is sent to the desulfurization device 55. The desulfurization device 55 removes hydrogen sulfide from the reformed gas sent from the alkaline washing device 54. The reformed gas from which hydrogen sulfide has been removed in the desulfurization device 55 is sent to the dehumidification device 56. The dehumidification device 56 removes moisture from the reformed gas sent from the desulfurization device 55.

[0031] In this embodiment, by shortening the distance from the water surface of the cooling wash water 80 stored inside the cooling wash device 50 to the spray nozzle 501 inside the cooling wash device 50, the momentum of the sprayed cooling wash water 80 weakens when it reaches the water surface of the stored cooling wash water 80, thereby making it possible to suppress the generation of reformed gas bubbles inside the cooling wash device 50 and ultimately suppress the generation of scum. Also, in this embodiment, the portion of the cooling wash water 80 stored in the cooling wash device 50 that is close to the water surface flows through the pipe 597 to the gas-water seal tank 59. Here, the cooling wash water 80 flowing through the pipe 597 contains scum and reformed gas bubbles generated inside the cooling wash device 50, making it possible to prevent scum from accumulating in the cooling wash device 50. Furthermore, in this embodiment, when the cooling cleaning water 80 containing scum and reformed gas bubbles flows in a spiral shape in the tapered portion 593 in the inflow chamber 592 of the gas-water sealed tank 59, the reformed gas bubbles are separated from the cooling cleaning water 80, thereby suppressing the generation of scum. Furthermore, in this embodiment, the inner diameter of the internal pipe 594 is larger than half the inner diameter of the main body 591, so the flow rate of the cooling cleaning water 80 flowing through the internal pipe 594 is slow. When this flow rate is slowed, the scum and reformed gas bubbles are less likely to be drawn downward, and the reformed gas bubbles are separated from the cooling cleaning water 80, thereby suppressing the generation of scum.

[0032] 1 Waste treatment device 20 Compression device 30 High-temperature reactor 50 Cooling and cleaning device 51 Acid cleaning device 52 Settling tank 53 Heat exchanger 59 Gas-water sealing tank 80 Cooling and cleaning water 501 Spray nozzle 592 Inlet chamber 593 Tapered portion 594 Internal piping 595 Gas duct 596, 597 Piping

Claims

1. A cooling and washing device that sprays cooling water onto the reformed gas discharged from a high-temperature reactor to cool and wash the reformed gas, comprising a hollow cylindrical main body, a tapered portion that is inclined downward from the inner surface of the main body toward the center and has a hole in the center, and a hollow cylindrical internal pipe that is connected to the tapered portion, the hollow portion of which is continuous with the hole of the tapered portion and is disposed inside the main body. The reformed gas and the cooling water flowing out of the cooling and washing device flow into a water seal tank on the upper side of the tapered portion. The cooling water flows in a spiral shape in the tapered portion and flows into the internal pipe. A cooling and washing system.

2. The reformed gas that has flowed into the upper side of the tapered portion together with the cooling water from the high-temperature reactor flows from the space on the upper side of the tapered portion to an acid washing device that acid-washes the reformed gas. The cooling and washing system according to claim 1.

3. The cooling water that has flowed into the internal pipe flows out from the lower end of the internal pipe, rises between the main body and the internal pipe, and flows into a sedimentation tank that separates solids contained in the cooling water. The cooling and washing system according to claim 1.

4. The cooling and washing device has a nozzle for spraying the cooling water, and the distance from the water surface of the cooling water stored inside the cooling and washing device to the nozzle is a distance for cooling the reformed gas to 100°C or less. The cooling and washing system according to claim 1.

5. The inner diameter of the internal pipe is at least half of the inner diameter of the main body. The cooling and washing system according to claim 1.