KR20150084462A - Apparatus for drying and recycling industrial sludge by using waste vapour - Google Patents

Abstract

The present invention provides an apparatus for drying and recycling wastewater sludge using waste vapor, which comprises: a supply unit for supplying as generating a vapor by a boiler; a storage unit for temporarily storing the vapor; a sludge drying unit arranged with a vapor circulation unit for drying as applying heat on wastewater sludge; a sludge transporting unit for transporting the wastewater sludge from one side to the other side of the inside of the sludge drying unit; a waste vapor collection unit for collecting waste vapor; a waste vapor compression unit for compressing the collected waste vapor; a radiating unit for drying the wastewater sludge as applying heat of the waste vapor to the wastewater sludge; a sludge melting unit for melting the wastewater sludge; a first circulation pipe for circulating the compressed water generated by the waste vapor to the vapor supply unit; a second circulation pipe for circulating combustion gas discharged from the sludge melting unit to the vapor supply unit; and a compressed water discharging unit for discharging as separating the compressed water and offensive odor gas generated by waste vapor discharged from the radiating unit. The present invention is capable of saving energy as recycling as heat energy in the drying process after collecting and compressing the waste vapor generated in the drying process of the waste water sludge.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for drying and recycling wastewater sludge,

The present invention relates to an apparatus for drying and recycling wastewater sludge using wastewater vapor, more particularly, to a wastewater sludge dryer that can recycle wastewater vapors discharged from the drying process of wastewater sludge, and the dried wastewater sludge is melted in a melting furnace, And the combustion gas generated from the melting furnace is related to a drying and recycling apparatus for wastewater sludge utilizing wastewater steam which can be utilized for the production of water vapor.

Wastewater sludge discharged from various industries contains several tens ppm or more of heavy metals such as chromium, nickel, arsenic and mercury harmful to the human body as shown in the following Table 1, and it is necessary to treat them safely.

[Table 1] shows examples of heavy metals contained in wastewater sludge generated in various industrial complexes in Korea.

Item A industrial complex
(mg / kg) B industrial complex
(mg / kg) C industrial complex
(mg / kg) Hg ND ND ND As ND ND ND CD 5 0.4 ND Cr 67 341 5,384 Al 163,448 64,022 8,994 Cu 255 1,160 1,764 Pb 1058 153 591 Zn 1,408 1,100 12,177

However, since waste water sludge contains heavy metals, additional air pollutant discharging facilities must be provided to prevent heavy metals from being contained in exhaust gas when directly burned. Therefore, There is an increasing problem.

In addition, since the wastewater sludge contains about 80% of water, when the water is dried by using the conventional combustion apparatus, it requires about 750 ~ 850 kcal of heat to evaporate 1 kg of water contained in the wastewater sludge, There is a problem that consumption is large.

In order to solve the above problems, Patent Document 10-0864529 is disclosed. The prior art described above is configured to remove heavy metals using microorganisms and to perform drying using water vapor.

However, in the case of the prior art described above, there is a limit in removal of heavy metals by microorganisms, and since water vapor used for drying is discharged after use, much energy is used for generating steam.

The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a wastewater treatment apparatus capable of collecting and compressing wastewater vapor generated in the drying process of wastewater sludge, And to provide a device for drying and recycling wastewater sludge utilizing the same.

It is another object of the present invention to provide an apparatus for drying and recycling wastewater sludge using wastewater steam which can be reused as building materials by melting in a melting furnace dried wastewater sludge in a drying apparatus.

It is another object of the present invention to provide an apparatus for drying and recycling wastewater sludge which utilizes wastewater vapor which can be recycled in the production of water vapor.

According to an aspect of the present invention, there is provided a steam generator comprising: a water vapor supply unit for generating and supplying water vapor by a boiler; A water vapor storage unit for temporarily storing the water vapor supplied from the water vapor supply unit; A sludge drying unit for supplying a space for receiving wastewater sludge to the inside, a steam circulation unit for circulating steam generated from the steam supply unit on the inner side, and drying the wastewater sludge by applying heat to the wastewater sludge; A sludge moving unit for moving the wastewater sludge from one side of the sludge drying unit to the other side; A wastewater vapor collecting unit for collecting wastewater generated in the drying process of the wastewater sludge; A waste water vapor compression unit for compressing the waste water vapor collected by the waste water vapor collection unit; A heat dissipation unit disposed inside the sludge drying unit to allow the wastewater vapor compressed in the steam compression unit to pass inward and to apply the heat of the wastewater vapor to the wastewater sludge to dry the wastewater sludge; A sludge melting unit for melting the wastewater sludge dried and discharged; A first circulation pipe for circulating the condensed water generated by the waste water vapor circulated in the water circulation unit and then discharged to the steam supply unit; A second circulation pipe for circulating the combustion gas discharged from the sludge fused portion to the steam supply portion; And a condensed water discharge unit for separating and discharging condensed water and odorous gas generated by the waste water vapor discharged from the heat dissipating unit. The present invention also provides an apparatus for drying and recycling wastewater sludge utilizing wastewater vapor.

The steam supply unit may supply steam at a pressure of 5 to 10 bar and a temperature of 150 to 200 ° C.

The wastewater vapor collecting unit may collect the wastewater vapor at a pressure of 1 to 2 bar (bar-absolute pressure) and a temperature of 100 to 130 ° C.

The wastewater vapor compression unit may compress the wastewater vapor to a pressure of 5 to 10 bar and a temperature of 150 to 200 ° C.

The wastewater vapor compression unit may be a positive type screw type compressor.

The condensed water discharge unit may expand the condensed water to a pressure of 1 bar or less.

The present invention can reduce the energy by collecting and compressing the wastewater vapor generated in the drying process of the wastewater sludge, and recycling it as thermal energy in the drying process.

Further, in the present invention, the wastewater sludge dried in the drying apparatus can be melted in a melting furnace and recycled as a building material or the like.

Further, the present invention can recycle the combustion gas generated in the melting furnace to the production of steam.

1 is a view showing the construction of an apparatus for drying and recycling wastewater sludge utilizing wastewater vapor according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

 1 is a view showing the construction of an apparatus for drying and recycling wastewater sludge utilizing wastewater vapor according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus 100 for drying and recycling wastewater sludge utilizing wastewater vapor according to an embodiment of the present invention includes a water vapor supply unit 110, a water vapor storage unit 120, a sludge drying unit 130, The sludge moving part 140, the waste water vapor collecting part 150, the waste water vapor compression part 160, the heat dissipating part 170, the sludge melting part 180, the first circulation pipe 134, the second circulation pipe 162 And a condensed water discharging portion 190.

The present invention will be described with reference to Fig.

The water vapor supply unit 110 produces and supplies water vapor required by operation of a boiler for burning fuel such as gas or oil. The water vapor supply unit 110 can supply and supply water vapor of high temperature and high pressure necessary for a water vapor consumer. The water vapor supply part 110 can supply water vapor having a pressure of 5 to 10 bar and a temperature of 150 to 200 ° C.

Since the water vapor supply unit 110 using a boiler is well known in the art, a detailed description thereof will be omitted. Accordingly, the boiler of the steam supply unit 110 is not separately shown in the drawing.

The water vapor storage unit 120 temporarily stores water vapor supplied from the water vapor supply unit 110. The water vapor storage unit 120 stores water vapor and then supplies the water vapor uniformly to the sludge drying unit 130, which will be described later.

The steam storage unit 120 temporarily stores the steam supplied from the steam supply unit 110, and then supplies the steam to the sludge drying unit 130, which will be described later. The steam storage part 120 can maintain a constant pressure of steam supplied.

The sludge drying unit 130 receives external wastewater sludge and high-temperature, high-pressure steam, and performs a predetermined drying process on the wastewater sludge using the supplied steam. Here, the drying treatment includes all of the drying processes for removing water from the wastewater sludge by using the heat of steam as one of various processes such as food processing, medicine production, and semiconductor processing.

In order to perform the above drying process, the sludge drying unit 130 provides a predetermined space for drying to the inside, steam is circulated through the steam storage unit 120 on the inner side, heat is generated to the waste water sludge A water vapor circulating unit 132 is disposed.

In the present invention, the steam circulation unit 132 is disposed on the inner side of the sludge drying unit 130, and heat of steam is applied to the wastewater sludge. However, if necessary, the sludge drying unit 130 As shown in Fig. In addition, although the outlet end of the wastewater vapor discharged after circulating the water circulation unit 132 is shown as being disposed in the middle of the water circulation unit 132, this is for the sake of simplicity of illustration, It is preferable to be disposed opposite to the opposite side of the inlet.

The wastewater vapor discharged from the water circulation unit 132 after the heat is applied to the wastewater sludge is discharged in the form of condensed water due to a decrease in temperature and pressure and is discharged to the water vapor supply unit 110 through the first circulation pipe 134 Can be circulated. The condensed water circulated to the steam supply unit 110 is again supplied to the sludge drying unit 130 after being vaporized by steam, and can be reused.

Since water vapor may be lost during operation of the apparatus, it is preferable that a water supply valve is disposed on the water vapor supply unit 110.

A supply port for receiving wastewater sludge may be disposed on one side of the upper portion of the sludge drying unit 130 and a connection pipe for supplying dried sludge to the sludge melting unit described later may be connected to the lower side.

The object to be treated in the sludge drying unit 130 may be a material having a water content of 30% or more, but the water content may be variously changed according to the needs of the user.

The sludge moving unit 140 is disposed inside the sludge drying unit 130 and is configured to rotate about a central axis. The sludge drier unit 140 is configured to rotate the wastewater sludge supplied as a drying object from one side of the sludge dryer 130 to the other side That is, it is moved from the supply port to the connection pipe connected to the melting portion.

For this purpose, the sludge moving unit 140 may have a body having a length corresponding to the inner width of the sludge drying unit 130 and a moving vane disposed on the outer circumferential surface thereof. However, the wastewater sludge The present invention is not limited thereto and can be manufactured in various forms according to the needs of the user.

At this time, the wastewater vapor generated from the wastewater sludge during the drying process of the sludge drying unit 130 can be collected by the wastewater vapor collecting unit 150 described later.

The wastewater vapor collecting unit 150 is connected to the sludge drying unit 130 to collect wastewater vapor generated during drying in the sludge drying unit 130 and discharged to the outside.

In the drying process, besides the wastewater vapor, other wastewater vapors (including odor gas, air, hydrocarbons, etc.) other than the wastewater vapor used for drying may be generated. The wastewater vapor collecting unit may collect such other gaseous substances have.

The wastewater vapor collection unit 150 adjusts the collected wastewater vapor to a pressure of 1 to 2 bar and a temperature of 100 to 130 degrees. Drying / Concentration If the internal pressure of the device generating steam is below about atmospheric pressure, the steam pressure is 1 bar (absolute pressure) and the temperature is 100 ℃ or less. When the water vapor in this state is directly supplied to the capacity type screw type compression apparatus of the wastewater vapor compression unit 160 to be described later, the performance of the capacity type screw type compression apparatus may be deteriorated or the introduction of the water vapor may be impossible. Accordingly, the wastewater vapor collecting unit 150 adjusts the trapped wastewater vapor to 1 to 2 bar and 100 ° C to 130 ° C to supply it to the wastewater vapor compression unit.

The wastewater vapor compression unit 160 may compress the wastewater vapor collected by the wastewater vapor collection unit 150 into a predetermined pressure state and then supply the wastewater vapor to the water vapor storage unit 120 through the second circulation pipe 162.

The wastewater vapor compression unit 160 compresses the collected wastewater vapor at a pressure of 5 to 10 bar and a temperature of 160 to 200 ° C which is a water vapor state used in the drying and concentration processing unit, ).

Here, the latent heat of the wastewater vapor compressed by the wastewater vapor compression unit 160 can be recycled in the sludge drying unit 130. This will be described later.

Here, the wastewater vapor compression unit 160 may be a positive type screw type compressor which is driven by a motor. In the volumetric screw type compressor, since the cooling water is sprayed directly from the outside to the water vapor in order to maintain the temperature of the water vapor properly during the compression process, the amount of water vapor at the outlet may be larger than the water vapor amount at the inlet.

The positive displacement screw type compressor of the wastewater vapor compression unit 160 has a strong suction force so that it is easy to use even when the pressure of the wastewater vapor entering the inlet is low and the pressure at the outlet side is lower than the pressure of the boiler It is high and easy to use.

Table 2 is a table showing the state of water vapor compression by the waste water vapor compression unit and the power and efficiency to be used.

division Water vapor compression device inlet
Wastewater steam specification Water vapor compression device outlet
Wastewater steam specification Water vapor compression device driven Total consumption power (a)
(kW) Motor consumption power /
Fuel calorific value for boiler
(%) Water vapor input
(Ton / hour) Steam absolute pressure
(bar) Water vapor temperature
(° C) Water vapor emission
(Ton / hour) Steam absolute pressure
(bar) Water vapor temperature
(° C) Screw type compressor 1.032 0.8 100 1.291 8 170 178 18.2 Turbo molecular type compressor 1.032 0.5 100 1.2 8 170 160 17.6

The energy efficiency of the wastewater vapor compression section can be converted as follows.

[Equation 1]

The energy efficiency of this embodiment is calculated by the following formula (1), which is 18.2%.

The water vapor compressed by the waste water vapor compression unit 160 may be supplied to the sludge drying unit 130 through the water vapor storage unit 120 and may be recycled. The drying and concentration apparatus of this embodiment compresses and recycles waste water vapor generated from the high-function material, so that the energy consumption of the entire apparatus can be reduced.

The process of recycling steam from the waste water vapor compression unit 160 to the sludge drying unit 130 is as follows.

A heat dissipating unit 170 is disposed inside the sludge drying unit 130.

The heat dissipating unit 170 may be formed of a coil-shaped tube having a predetermined length and diameter. The waste water vapor compressed in the waste water vapor compression unit 160 passes through the inside of the heat dissipating unit 170 and is heat-exchanged with the waste water sludge to dry the waste water sludge.

A heat exchange pin may be disposed on the outer circumferential surface of the heat dissipation unit 170 to facilitate heat exchange.

On the other hand, the water vapor supplied from the water vapor storage unit 120 to the sludge drying unit 130 is used as a heat source, and a part of the water vapor is totally consumed by the latent heat and is discharged as condensed water. . The discharged condensed water and odor gas are transferred to the condensed water discharge unit 190.

The condensed water discharge unit 190 separates the condensed water and the malodorous gas, and the separated condensed water is discharged to the outside.

The condensed water discharge unit 190 has a low pressure of 1 bar or less. When the condensed water and odorous gas discharged from the sludge drying unit 130 flow into the interior of the condensed water discharge unit 190, the condensed water discharge unit 190 expands due to a low pressure inside.

The density change of the condensed water due to the expansion in the condensed water discharge portion 190 is small, but the density of the odorous gas is reduced to 1/5 or less and separated from the condensed water.

The condensate can be treated by an external separate processing device. Further, the separated odor gas can be discharged into the atmosphere, but can be incinerated and removed through the boiler of the water vapor supply unit 110 through a separate supply unit.

The sludge melting unit 180 melts the wastewater sludge dried and discharged in the sludge drying unit 130, and discharges the sludge in a vitrified state.

Table 3 shows the components of the wastewater sludge described in [Table 1] above.

division Sludge type A B C Ash
(wt.%) SiO ₂ 36.2 50.58 49.60 Al ₂ O ₃ 16.3 31.38 18.37 Fe ₂ O ₃ 26.6 8.64 6.71 CaO 12.4 4.28 5.43 MgO - 2.50 1.30 MnO 0.7 - - Na ₂ O - - 1.15 K ₂ O 6.1 1.65 2.14 TiO ₂ 1.73 0.78 0.84 P ₂ O ₅ - - 14.30

When the wastewater sludge is melted by applying a high temperature of 1300 ° C or higher, the heavy metals and minerals of the wastewater sludge are melted and discharged in a vitrified state.

[Table 4] shows the melting temperature of the components contained in the wastewater sludge.

heavy metal
Dry sludge (mg / kg) Melting point (캜) Ash
(wt%) Melting point (캜) Arsenic, As (10) 817 SiO ₂ (30-50%) 1600 Cadmium, Cd (10) 321.07 Al ₂ O ₃ (20-30%) 2050 Chromium, Cr (500) 1907 Fe ₂ O ₃ (10-70%) 1550 Cobalt, Co (30) 1495 CaO (5-15%) 2570 Copper, Cu (800) 1084.62 MgO (1%) 2826 Iron, Fe (17,000) 1538 MnO (1%) 1650 Lead, Pb (500) 327.46 Na ₂ O (1%) 400 < Manganese, Mn (260) 1246 K ₂ O (1-6%) 100 (boiling point) Mercury, Hg (6) -38.83 TiO ₂ (1-2%) 1843 Molybdenum, Mo (4) 2617 P ₂ O ₅ (0-5%) 350 Nickel, Ni (80) 1455 Selenium, Se (5) 217 Tin, Sn (14) 231.93 Zinc, Zn (1,700) 419.53 Aluminum, Al 660

Wastewater sludge, which is melted and discharged, can be used in a wide variety of materials such as aggregates, soil reinforcements, and soil materials because the release of heavy metals is below the environmental standard.

In addition, the combustion gas generated during the melting process in the melting furnace can be used for various purposes such as being supplied to the steam supply part 110 and used for producing steam.

The present invention can reduce energy by collecting and compressing wastewater vapor generated during the drying process of the wastewater sludge and recycling it as thermal energy in the drying process described above, and the wastewater sludge dried in the drying device is melted in the melting furnace, Can be recycled. Further, the present invention can recycle the combustion gas generated in the melting furnace to the production of steam.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: Drying and concentration apparatus
110: Water vapor supply part
120: Water vapor storage part
130: drying and concentration processing unit
134: first circulation pipe
140: Wastewater vapor collection section
150: Wastewater vapor compression section
160: Condensate discharge part
162: second circulation pipe
170: Odor gas discharge line

Claims (6)

A water vapor supply unit for generating and supplying water vapor by the boiler;
A water vapor storage unit for temporarily storing the water vapor supplied from the water vapor supply unit;
A sludge drying unit for supplying a space for receiving wastewater sludge to the inside, a steam circulation unit for circulating steam generated from the steam supply unit on the inner side, and drying the wastewater sludge by applying heat to the wastewater sludge;
A sludge moving unit for moving the wastewater sludge from one side of the sludge drying unit to the other side;
A wastewater vapor collecting unit for collecting wastewater generated in the drying process of the wastewater sludge;
A waste water vapor compression unit for compressing the waste water vapor collected by the waste water vapor collection unit;
A heat dissipation unit disposed inside the sludge drying unit to allow the wastewater vapor compressed in the steam compression unit to pass inward and to apply the heat of the wastewater vapor to the wastewater sludge to dry the wastewater sludge;
A sludge melting unit for melting the wastewater sludge dried and discharged;
A first circulation pipe for circulating the condensed water generated by the waste water vapor circulated in the water circulation unit and then discharged to the steam supply unit;
A second circulation pipe for circulating the combustion gas discharged from the sludge fused portion to the steam supply portion; And
A condensed water discharge unit for separating and discharging condensed water and odorous gas generated by the waste water vapor discharged from the heat dissipating unit; And a drying and recycling device for the wastewater sludge utilizing the wastewater vapor. The method according to claim 1,
The water vapor supply portion,
An apparatus for drying and recycling wastewater sludge which supplies water vapor at a pressure of 5 to 10 bar (bar-absolute pressure) and a temperature of 150 to 200 ° C. The method according to claim 1,
Wherein the wastewater vapor collecting unit collects the wastewater vapor at a pressure of 1 to 2 bar (bar-absolute pressure) and a temperature of 100 to 130 ° C. The method of claim 3,
The wastewater vapor compression unit may comprise:
Wherein the wastewater vapor is compressed to a pressure of 5 to 10 bar (bar-absolute pressure) and a temperature of 150 to 200 ° C. 5. The method according to any one of claims 1 to 4,
The wastewater vapor compression unit may comprise:
Drying and recycling apparatus for wastewater sludge as a volumetric screw type compressor. The method according to claim 1,
The condensed-
Wherein the condensate is expanded to a pressure of 1 bar or less.

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