JP2005040662A - Wastewater evaporation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wastewater evaporation apparatus wherein a mist collection filter is prevented from being clogged by suppressing sedimentation of sludge on the mist collection filter. <P>SOLUTION: The wastewater evaporation apparatus is equipped with a hot air producing furnace, an evaporation column communicating with the hot air producing furnace through a hot air passage, a drain passage extending from the bottom part of the evaporation column to the upper part of the evaporation column and the upper part of the hot air producing furnace, a pump arranged on the way of the drain passage, a spray nozzle attached to the end part on the side of the hot air producing furnace of the drain passage and the mist collection filter arranged above the end part on the side of the hot air producing furnace of the drain passage within the evaporation column. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an evaporation device for drainage discharged from a surface treatment facility or a coating facility.
[0002]
[Prior art]
An apparatus for evaporating wastewater from a surface treatment facility is disclosed in Patent Document 1 and the like. As shown in FIG. 1, the conventional evaporator includes an evaporation tower 1 that also serves as a hot-air generating furnace. On the side wall of the evaporation tower 1, a waste heat intake port 1a and an outside air intake port 1b of the coating equipment drying furnace are formed, and a burner 2 is attached. An exhaust fan 3 and an exhaust duct 4 are attached to the ceiling wall of the evaporation tower 1. A drain pipe 5 extends from the bottom of the evaporation tower 1 to the top of the evaporation tower 1. A pump 6 is disposed in the middle of the drain pipe 5. A spray nozzle 7 is attached to the upper end of the drainage pipe 5 on the evaporation tower. A mist collecting filter 8 is disposed in the evaporation tower 1 and above the spray nozzle 7. At the bottom of the evaporation tower 1, wastewater that flows from a surface treatment facility and a painting facility (not shown) is stored.
In the conventional evaporation apparatus having the above configuration, the outside air sucked from the outside air inlet is heated by the drying furnace waste heat or the burner combustion heat, and hot air is generated in the evaporation tower 1. The hot air rises in the evaporation tower 1, heats the waste water mist sprayed from the spray nozzle 7, and evaporates the water in the waste water mist. The precipitated sludge falls into the wastewater stored at the bottom of the evaporation tower 1. A portion of the drainage mist does not evaporate and is entrained by hot air and rises, but is collected by the mist collection filter 8. The water vapor separated from the waste water is sucked together with the exhaust gas by the exhaust fan 3 and discharged from the evaporator through the exhaust duct 4.
[0003]
[Patent Document 1] JP-A-8-218189
[0004]
[Problems to be solved by the invention]
The conventional evaporator shown in FIG. 1 has the following problems.
(1) Since all the precipitated sludge returns to the wastewater stored at the bottom of the evaporation tower 1, the sludge concentration in the wastewater in the evaporation tower is high, and the mist collection filter 8 tends to precipitate the mist collection filter. Is prone to clogging.
(2) Since a large amount of waste water mist is collected by the mist collecting filter, sludge is likely to be deposited by the mist collecting filter 8, and the mist collecting filter is likely to be clogged.
This invention is made | formed in view of the said problem, and it aims at providing the evaporation apparatus of the waste_water | drain which the sludge precipitation by the mist collection filter was suppressed and the clogging of the mist collection filter was suppressed.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a hot air generating furnace, an evaporation tower communicating with the hot air generating furnace via a hot air passage, and drainage extending from the bottom of the evaporation tower to the upper part of the evaporation tower and the upper part of the hot air generating furnace. A passage, a pump disposed in the middle of the drainage passage, a spray nozzle attached to the upper end of the hot air generating furnace of the drainage passage, and the upper part of the drainage passage above the upper end of the evaporation tower. Provided is a wastewater evaporation apparatus comprising a mist collecting filter disposed.
In the present invention, the hot air generated in the hot air generating furnace flows into the evaporation tower through the hot air passage, and evaporates the water in the wastewater discharged from the upper end of the evaporation passage in the drainage passage. The deposited sludge returns to the wastewater stored at the bottom of the evaporation tower. Part of the wastewater stored at the bottom of the evaporation tower is misted in a hot air generator. The sludge deposited by the evaporation of water in the waste water mist falls and accumulates at the bottom of the hot air generator, and does not return to the waste water stored at the bottom of the evaporation tower. As a result, an increase in the sludge concentration in the wastewater stored at the bottom of the evaporation tower is suppressed, sludge precipitation on the mist collection filter is suppressed, and clogging of the mist collection filter is suppressed.
[0006]
In a preferred aspect of the present invention, the evaporation apparatus includes a perforated plate disposed in the evaporation tower and below the upper end of the drainage passage on the upper side of the evaporation tower.
By dripping the wastewater from the perforated plate, the generation of wastewater mist in the evaporation tower is suppressed while ensuring a sufficient contact area between the wastewater and hot air, and sludge precipitation in the mist collection filter is suppressed, and mist trapping is achieved. Clogging of the collecting filter is suppressed.
[0007]
In a preferred aspect of the present invention, the evaporation apparatus includes a plurality of perforated plates that are spaced apart from each other in the vertical direction.
By disposing a plurality of perforated plates in the vertical direction at intervals, the contact area between the hot air and the drainage increases, and the drainage evaporation efficiency improves.
[0008]
In a preferred aspect of the present invention, the evaporation apparatus includes a meandering passage formed by a plurality of perforated plates.
When hot air flows through the meandering passage, the residence time of the hot air in the evaporation tower increases, the temperature of the evaporation tower rises, and the efficiency of drainage evaporation improves.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A drainage evaporation apparatus according to an embodiment of the present invention will be described.
As shown in FIG. 2, the wastewater evaporation apparatus according to the present embodiment includes a hot air generating furnace 11. On the surrounding wall of the hot air generating furnace 11, a waste heat intake port 11 a and an outside air intake port 11 b of a painting facility drying furnace (not shown) are formed, and a burner 12 is attached. The hot air generating furnace 11 communicates with the evaporation tower 14 via the hot air passage 13.
An exhaust fan 15 and an exhaust duct 16 are attached to the ceiling wall of the evaporation tower 14. A drain pipe 17 extends from the bottom of the evaporation tower 14 to the top of the evaporation tower 14. A pump 18 is disposed in the middle of the drain pipe 17. A drain pipe 19 that branches from the drain pipe 17 downstream of the pump 18 extends to the upper part of the hot air generating furnace 11. A spray nozzle 20 is attached to the upper end of the hot air generating furnace of the drain pipe 19.
[0010]
A plurality of perforated plates 21 are arranged in the evaporation tower 14 and below the upper end portion of the drainage pipe 17 on the upper side of the evaporation tower, spaced apart from each other in the vertical direction. One side of the perforated plate 21 is fixed to the side wall of the evaporation tower 14. A dam plate 21 a is fixed to the remaining three sides of the porous plate 21. A serpentine hot air passage 22 is formed by the plurality of perforated plates 21. A mist collection filter 23 is disposed in the evaporation tower 14 and above the upper end portion of the drain pipe 17 on the upper side of the evaporation tower.
At the bottom of the evaporation tower 14, waste water flowing from a surface treatment facility and a painting facility (not shown) is stored.
[0011]
In the wastewater evaporation apparatus having the above configuration, the outside air sucked from the outside air inlet 11 b is heated by the drying furnace waste heat or the burner combustion heat, and hot air is generated in the hot air generating furnace 11. The hot air heats the waste water mist sprayed from the spray nozzle 20 and evaporates the water in the waste water mist. The precipitated sludge accumulates at the bottom of the hot air generator 11. Sludge accumulated at the bottom of the hot air generator 11 does not return to the evaporation tower 14. Sludge accumulated at the bottom of the hot air generator 11 is periodically removed.
The steam flows together with the hot air into the evaporation tower 14 through the hot air passage 13 and rises through the meandering hot air passage 22.
[0012]
The drainage discharged from the upper end of the evaporation pipe 17 of the drainage pipe 17 collects on the uppermost porous plate 21 and drops into the meandering hot air passage 22 below from a large number of small holes formed in the porous plate 21. The dropped drainage is successively accumulated on the lower porous plate 21, dropped in the meandering hot air passage 221 and finally returned to the drainage stored in the bottom of the evaporation tower 14. The water droplets of the waste water falling in the meandering hot air passage 22 are heated in contact with the hot air rising in the meandering hot air passage 22 and the water in the waste water evaporates. The deposited sludge falls into the wastewater accumulated on the lower porous plate 21 and finally returns to the wastewater stored at the bottom of the evaporation tower 14.
[0013]
A part of the waste water discharged from the upper end of the evaporation tower 17 of the drain pipe 17 becomes mist and is raised by hot air rising in the evaporation tower 14, but is collected by the mist collecting filter 23.
The water vapor separated from the waste water is sucked into the exhaust fan 15 together with the exhaust gas, and is discharged from the waste water evaporator through the exhaust duct 16.
[0014]
Part of the wastewater stored at the bottom of the evaporation tower 14 is misted in the hot air generating furnace 11, and sludge deposited as a result of evaporation of water in the wastewater mist falls to the bottom of the hot air generating furnace 11. By accumulating and not returning to the wastewater stored at the bottom of the evaporation tower 14, an increase in the sludge concentration in the wastewater stored at the bottom of the evaporation tower 14 is suppressed, and sludge precipitation on the mist collecting filter 23 is prevented. The clogging of the mist collecting filter 23 is suppressed.
[0015]
By dripping the waste water from the perforated plate 21, generation of waste water mist in the evaporation tower 14 is suppressed while ensuring a sufficient contact area between the waste water and hot air, and sludge precipitation in the mist collecting filter 23 is suppressed. The clogging of the mist collecting filter 23 is suppressed.
By disposing the plurality of perforated plates 21 in the vertical direction at intervals, the contact area between the hot air and the drainage increases, and the drainage evaporation efficiency improves.
When hot air flows through the meandering hot air passage 22, the residence time of the hot air in the evaporation tower 14 increases, the temperature of the evaporation tower 14 rises, and the evaporation efficiency of waste water improves.
[0016]
【The invention's effect】
As described above, in the present invention, a portion of the wastewater stored at the bottom of the evaporation tower is misted in the hot air generating furnace, and the sludge precipitated by the evaporation of water in the wastewater mist is the hot air generating furnace. By not returning to the wastewater accumulated at the bottom of the evaporation tower and stored at the bottom of the evaporation tower, the increase in sludge concentration in the wastewater stored at the bottom of the evaporation tower is suppressed, and sludge precipitation on the mist collecting filter is suppressed. Thus, clogging of the mist collecting filter is suppressed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a conventional waste water evaporator.
FIG. 2 is a cross-sectional view of a wastewater evaporation apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,14 Evaporation tower 5,17,19 Drain pipe 7,20 Spray nozzle 8,23 Mist collection filter 11 Hot-air generation furnace 13 Hot-air channel | path 21 Porous board 22 Meandering hot-air channel | path

Claims (4)

Hot air generating furnace, an evaporation tower communicating with the hot air generating furnace via the hot air passage, a drainage passage extending from the bottom of the evaporation tower to the upper part of the evaporation tower and the upper part of the hot air generating furnace, and a pump disposed in the middle of the drainage passage A spray nozzle attached to the upper end of the hot air generating furnace of the drainage passage, and a mist collecting filter disposed in the evaporation tower and above the upper end of the upper side of the drainage passage of the drainage passage. A wastewater evaporation device. The wastewater evaporation apparatus according to claim 1, further comprising a perforated plate disposed in the evaporation tower and below the upper end of the drainage passage on the upper side of the evaporation tower. The waste water evaporation apparatus according to claim 2, comprising a plurality of perforated plates arranged at intervals in the vertical direction. The drainage evaporator according to claim 3, further comprising a meandering passage formed by a plurality of perforated plates.

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