KR100508410B1 - Sewage and wastewater sludge dryer including microwave - Google Patents

Abstract

The present invention relates to drying wastewater sludge by using a combination of microwave, hot air and steam. More specifically, in addition to the microwave heating method having excellent drying and sterilization functions, convection heat and hot air conduction by hot air are conducted. The present invention relates to a sewage sludge drying apparatus including microwaves that allow sludge to be dried quickly and completely through synergistic effects of organically operated heat transfer, as well as energy saving and environmental pollution.

The present invention includes a primary dryer for primary drying by applying a combination of microwave and hot air to the sludge discharged to the outside while passing through the inside of the plurality of cavities continuously connected to the conveyor;

After passing through the first dryer and supplied to the internal drying chamber of the steam jacket connected continuously, by applying the microwave, hot air, and steam to the sludge discharged to the outside through the steam jacket sequentially through the inside of the steam jacket, the secondary A secondary dryer for drying;

It is made by providing a tertiary dryer to completely dry the sludge by applying hot air and steam or microwave at the same time to the sludge which passed through the first and second dryers continuously.

Description

Sewage and wastewater sludge dryer including microwave}

The present invention relates to drying wastewater sludge by using a combination of microwave, hot air and steam. More specifically, in addition to the microwave heating method having excellent drying and sterilization functions, convection heat and hot air conduction by hot air are conducted. The present invention relates to a sewage sludge drying apparatus including microwaves that allow sludge to be dried quickly and completely through synergistic effects of organically operated heat transfer, as well as energy saving and environmental pollution.

In general, the treatment of sludge from sewage treatment plants depends mainly on dumping at sea and landfill, but the dumping of sludge from the domestic and overseas is planned to be banned from 2005 in accordance with the London Convention Amendment adopted in 1996. The problem is a serious problem.

As a method for treating sludge, various methods such as ocean dumping, landfilling, fertilization, fueling, solidification, incineration, melting, and pyrolysis have been proposed, but although the methods are different, they generally reduce water content and reduce environmental pollution to a certain level. It has a common purpose of preventing (propagation of pathogenic bacteria).

However, the techniques to achieve the above common purpose have been a significant problem to date, and most of them rely on the simple incineration method, but due to the strong resistance and high water content (70 ~ 85%) of local residents to incinerator construction. As a result, problems such as enormous driving costs are required.

Therefore, in recent years, a drying apparatus for drying sludge by using various energy such as microwaves and hot air is avoided by incineration.

The drying apparatus is the most commonly used convection heat or conduction heat in the industry in this case, in which case the situation is using the hot air or steam as a heat source for drying or the drying time is long and the drying does not evenly dry the uniformity of the product Not to be learned, of course, was accompanied by the problem of generating fine dust or dust by hot air.

In addition, a drying apparatus using a microwave, which is a new concept of dielectric heating, has been proposed, which deviates from the limitation of the conventional heating method.

The microwave drying apparatus is a very high drying capacity by heating the dried material in a short time, the heating is made uniform, it was very effective in the sterilization of pathogenic microorganisms.

Among the various drying methods described above, most conventional drying apparatuses do not have to be used in combination with each other, and thus, individual problems are pointed out as a result of the poor drying ability.

In other words, the conduction heat or convection heat type drying device causes a problem that the drying time is delayed and cannot be uniformly heated. A drying device using only pure microwave alone requires a high cost and a huge power cost. Due to the economic deterioration, most of the continuous conveyor method occupies a very large installation space was difficult to apply to the site.

As a result, there is an urgent need for a complex drying apparatus that can solve the problems caused by individual methods by combining the various methods in a complex and organic manner.

The present invention is to combine the convection heat conduction and conduction heat transfer method and the dielectric heating method by microwave in combination to achieve the purpose of reducing the water content of the sludge to a certain level and to reduce the environmental pollution at the same time.

The present invention allows the sludge to be supplied quantitatively to be changed to semi-dry state while passing through the primary dryer using microwave alone or using hot air, and the secondary dryer using microwave, hot air and steam sequentially. In order to be dried again while passing through, the sludge passed through the first and second dryers are finally passed through a tertiary dryer using a combination of hot air and steam or microwave, and the technology to change to a completely dry state is devised. .

The configuration of the preferred embodiment for effectively achieving the object of the present invention will be described.

The present invention adopts the microwave heating method as a basic method, but operates by combining the convective heat method by hot air and the conductive heat method by steam, and saves energy and shortens the drying time compared to the conventional method. And a dominant feature of the invention that the effect of reducing environmental pollution can be achieved.

The overall configuration of the present invention to achieve the above-mentioned characteristic gist is a discharge sludge hopper 10 for supplying the stored sludge to the primary dryer 100 in a quantitative manner, and the conveyor after being supplied from the discharge sludge hopper 10 105 through the primary dryer 100 and the primary dryer 100 to dry first by applying the microwave and hot air to the sludge discharged to the outside via the plurality of cavities 101 to the outside through the primary dryer 100 After being supplied to the internal drying chamber 204 of the steam jacket 201 continuously connected, the microwaves and the hot air in the sludge discharged to the outside through the interior of the steam jacket 201 sequentially by the transfer force of the rotary carrier 210 , The secondary dryer 200 to dry the secondary by adding steam in combination, and the sludge by finally applying hot air and steam or microwave to the sludge that passed continuously through the first and second dryers 100 and 200 It can be seen that constituted by any combination of the configuration of the third dryer 300 to dry.

Hereinafter, the present invention having the schematic configuration will be described in more detail.

First, the discharge sludge hopper 10 for supplying the sludge which is a drying object to the drying apparatus of the present invention may utilize a hopper installed and operated in an existing wastewater treatment plant, and the discharge sludge hopper 10 may be fixed through a dehydrator. Sludge having a reduced partial moisture content is transported, supplied and stored by a conveyor, and the sludge is quantitatively supplied to the primary dryer 100 by a quantitative feeding device formed at an outlet of the discharge sludge hopper 10.

Here, the sludge that passed through the dehydrator, which is a process before being introduced into the primary dryer 100, has a general adhesiveness, and when it is adsorbed inside a general dryer, a scale is generated and a drastic reduction in drying efficiency occurs. This corresponds to most drying apparatuses using conventional conductive heat or convection heat.

In view of the above-mentioned problems, the present invention uses a high-efficiency microwave alone in the primary dryer 100, which is a primary drying process, or simultaneously combines the microwave and hot air to evaporate a large amount of moisture in a short time, and at the same time, has no adhesiveness. It can be changed to dry sludge.

The configuration of the primary dryer 100 for this is a plurality of cavities 101 are continuously installed via a communication tube 102 as shown in Figure 2 to 3, the cavity disposed on both sides of the cavity 101 ( Each of the inlet 103 and the outlet 104 is formed in each of the 101 is discharged or discharged, the conveyor 105 is a conveying means through the inlet 103, a plurality of cavities 101, outlet 104 ) Is installed so that the first drying operation can be performed while the sludge passes through the inside of the cavity 101 by the conveyor 105.

In this case, the cavity 101 may be a single-mode type having a very high heating efficiency. In this case, the cavity 101 may be formed as a traveling waveguide type.

A microwave generator 106 is installed at one side of the upper surface of the cavity 101 to generate microwaves having excellent drying ability and irradiate the microwaves to sludge passing through the cavity 101. The microwave generator 106 may be a magnetron of a general type.

The hot air of a high temperature may be supplied to the inside of the cavity 101 to generate a synergy effect due to the irradiation of the microwave, and for this purpose, the upper and lower surfaces of the cavity 101 may supply and exhaust the hot air. Since the perforated net 107 of the micro holes is formed, as the hot air is supplied into the cavity 101 through the perforated net 107, the drying effect of the sludge can be doubled.

Here, the hot air is more preferably supplied from the bottom to the top, unlike the microwave irradiated downward by the microwave generator 106 so that the drying capacity can be further doubled.

In other words, the hot air is supplied in a counter-current direction opposite to the direction of microwave irradiation, whereby the thermal efficiency can be further enhanced.

On the other hand, when the microwave is irradiated inside the cavity 101, since a peak point is generated every 1/4 position of the wavelength in the tube, there is a problem that the microwave does not uniformly heat the dried material (sludge). Therefore, in the present invention, the microwave transducer 108 is installed at the tip of the cavity 101 at the position where the microwave generator 106 is installed, and the microwave transducer 108 is different inside the plurality of cavities 101. By adjusting the position to form top dead center at the position, the sludge is uniformly heated.

Furthermore, the microwave generator 106 and the microwave generator 106 installed in the cavity 101 are directed to both sides of the cavity 101 so that the microwaves can be irradiated more uniformly to the sludge passing through each of the continuously installed cavity 101. As it is installed alternately, left and right balances are maintained to obtain a more uniform heating effect, thereby improving drying quality.

The sludge in the primary dried state while passing through the primary dryer 100 can be dried in a more complete form while continuously passing the secondary dryer 200 that applies microwaves, hot air, and steam in combination. .

The secondary dryer 200 has a shape in which a plurality of steam jackets 201 formed in a circle are continuously arranged to maximize the heat transfer area within a limited space.

The steam jacket 201 has a dual structure of inner and outer walls 202 and 203, and forms a drying chamber 204 in which sludge is dried, and a space between the inner and outer walls 202 and 203. Hot steam may be injected into the sludge passing through the drying chamber 204 to supply additional heat energy, and the steam jackets 201 may be continuously installed such that the drying chambers 204 communicate with each other.

Here, the reason for supplying steam to the steam jacket 201 is to use drying only in consideration of the problem of low economical efficiency as the general industrial power cost according to the operation of the microwave generator 106 is used alone. In order to significantly reduce the steam, the steam does not need to be supplied to the space between the inner and outer walls 202 and 203 as a whole, but may be supplied only to the lower part of the steam jacket 201, which is a path for transporting the sludge. As the diaphragm is installed in the center between the inner and outer walls 202 and 203 to isolate the upper and lower parts, unnecessary steam supply to the upper portion of the steam jacket 201 is not performed.

In addition, a waveguide 206 for irradiating microwaves downward is installed at an inner center of the steam jacket 201, and the waveguide 206 can uniformly irradiate microwaves to sludge transported along the bottom of the drying chamber 204. The plurality of irradiation holes 207 are repeatedly formed in a zigzag form on both sides of the bottom surface.

Here, a pair of reflecting plates for matching to both sides of the waveguide 206 so that the microwaves irradiated downward through the irradiation hole 207 can be scattered to the outside to maximize the drying effect while concentrating on the sludge at the bottom ( 208 is installed to be inclined toward the lower outward.

The outside of the waveguide 206 is transported to and discharged from the outlet 104 on the other side while sequentially passing through the inside of each steam jacket 201 in order to quantitatively measure the sludge in the first dry state through the one side inlet 103. Rotating conveying body 210 is installed.

The rotary transfer member 210 is rotatably installed in the drying chamber 204 by a separate drive motor, a plurality of transfer wings for rotating the sludge to the outside of the cylindrical rotating body 211 to the maximum amount ( 212 is radially installed, and a sludge transport path 215 is naturally formed between the rotary body 211 and the inner wall 202 of the steam jacket 201.

The rotational transfer member 210 is more preferably made of a material having a material that allows microwaves to be transmitted to the sludge conveyed along the sludge transport path 215 smoothly.

In addition, the conveyance force of the sludge by the rotary transfer member 210 is improved, as well as the diameter of the inner wall 202 serving as a heat transfer plate so that the conductive heat source by steam is more smoothly conducted to the sludge or the rotary transfer member By forming a larger diameter of the 210, the adhesion of the sludge in close contact with the inner wall 202 can be increased.

This serves to offset the decrease in volume as the water content of the sludge is lowered as the drying proceeds.

Meanwhile, the sludge is combined with microwaves radiated from the waveguide 206 and high temperature steam supplied to the space between the inner and outer walls 202 and 203 to drastically improve the drying efficiency, as well as to add the sludge transport path 215. ), The hot air is directly applied, which further doubles the drying efficiency.

The hot air is supplied to the inside through an air supply unit 217 formed on one outer wall of the sludge transport path 215 to dry the sludge and then to the outside through the exhaust unit 218 formed on the other side as shown in FIGS. 5 to 6. It is made of a configuration that is exhausted.

The tertiary dryer 300 which finally processes the sludge that has passed sequentially through the primary and secondary dryers 100 and 200 is made of a well-known configuration formed of a ribbon jacket-type steam jacket, and the primary and secondary drying. Hot air and steam or microwave are added to the processed sludge to achieve a more complete drying condition.

On the other hand, all the hot air and steam used in the drying apparatus of the present invention by using a high temperature exhaust gas and steam generated by operating the steam boiler using the biogas (methane) generated in the sewage sludge treatment plant to dramatically reduce the operating cost You can save.

The drying process of the sludge according to the present invention having such a configuration will be described.

The sludge supplied from the discharge sludge hopper 10 may be discharged to the outside via the interior of the cavity 101 continuously installed through the conveyor 105 of the primary dryer 100.

During this movement, the microwaves by the microwave generator 106 are irradiated to the sludge inside the cavity 101, and at the same time, the sludge is rapidly supplied as hot air is supplied in the form of microwaves and countercurrent through the perforated network 107 of the bottom surface. And it can be dried uniformly.

The improvement of the drying efficiency is the data analysis table of the drying experiment according to the conventional case of applying only hot air alone, as in the embodiment of the following experimental conditions, and the case of simultaneously using the microwave together with the hot air as in the present invention. You can easily check through.

Example 1

Experimental conditions: ① Microwave output: 600Ｗ (actual output) --- Power consumption: 1.200Ｗ / hr

          ② Hot air: 120 ℃, 8㎥ / min --- Power consumption: 4,200Ｗ / hr

③ Sludge: Initial moisture content 80% → dry to 10% (300g → 70g)

The sludge of the first dried state through the primary dryer 100 is sequentially supplied to the sludge transport path 215 of the steam jacket 201 through the inlet 103 of the secondary dryer 200, The sludge may be discharged to the outside through the discharge port 104 via the steam jacket 201 sequentially rotated by the conveying blade 212 of the rotary carrier (210).

In this case, microwaves radiated from the waveguide 206 are applied to the sludge conveyed along the sludge conveying path 215, and at the same time, the heat of conduction by steam injected between the inner and outer walls 202 and 203 and the sludge conveying path ( The hot air supplied directly to 215 allows for a faster and more complete drying operation.

Therefore, the sludge that is not dried while passing through the primary dryer 100 may be dried in a perfect form as it passes through the secondary dryer 200.

Furthermore, the sludge coarsely passed through the primary and secondary dryers 100 and 200 may further double the drying state while passing through the tertiary dryer 300.

On the other hand, the present invention can be configured as a single type to install one or two secondary dryers (100, 200) each, as well as a multi-stage type to be installed in two or more places in consideration of the working environment and conditions. The drying operation can be performed.

In addition, the present invention is illustrated as a sludge, but is not necessarily limited thereto, and may be used for the purpose of drying a variety of dry items such as food, ceramics, powdery particles, and the like. It will not be able to escape the scope of the present invention alone.

According to the present invention, the sludge having a high water content passes sequentially through a primary dryer using microwaves and hot air and a secondary dryer using microwave, hot air and steam in sequence, and finally passing through a tertiary dryer using hot air and steam together. The synergy effect is achieved through the complex drying process, so that the sludge can be dried quickly and completely, and energy saving and environmental pollution reduction can be provided.

In addition, the sterilization effect by the microwave can be obtained without a separate process, thereby providing a side effect of recycling the sludge by fertilizing and composting.

1 is a block diagram showing the drying flow of the sludge according to the present invention

Figure 2 is a front view of the primary dryer of the present invention

3 is a plan view of the primary dryer of the present invention

Figure 4 is a side view of the primary dryer of the present invention

Figure 5 is a longitudinal sectional view showing the internal structure of the secondary dryer of the present invention

Figure 6 is a simultaneous supply state of microwaves and hot air of the secondary dryer of the present invention

7 is an enlarged view of the present invention the rotary carrier

8 is a bottom view of the waveguide of the present invention.

[Explanation of symbols on the main parts of the drawings]

10: discharge sludge hopper 100: primary dryer

101: cavity 105: conveyor

106: microwave generator 108: microwave transducer

107: perforated network 200: secondary dryer

201: steam jacket 206: waveguide

208: reflector 210: rotating carrier

212: feed wing 300: tertiary dryer

Claims (11)

delete delete A plurality of cavities 101 are continuously connected via a communication tube 102, the sludge through the inlet 103 of the one cavity 101 to the other outlet 104 via the interior of the cavity 101. Conveyor 105 is provided to be transported to be discharged, the upper one side of the cavity 101, the primary dryer 100 for drying by adding a microwave and hot air to the sludge in which the microwave generator 106 is installed; And After being supplied to the drying chamber 204 of the steam jacket 201 continuously connected through the primary dryer 100, the steam is discharged to the outside via the inside of the steam jacket 201 by the rotary transfer member 210 in sequence. It is configured to include; secondary dryer 200 for drying by adding a microwave, hot air, steam to the sludge to be combined The upper and lower surfaces of the cavity 101 of the primary dryer 100 are formed as perforated nets 107 for supplying hot air, and the hot air supplied through the perforated nets 107 is opposite to the direction of microwave irradiation. Wastewater sludge drying apparatus comprising a microwave, characterized in that the supply method. A plurality of cavities 101 are continuously connected via a communication tube 102, the sludge through the inlet 103 of the one cavity 101 to the other outlet 104 via the interior of the cavity 101. Conveyor 105 is provided to be transported to be discharged, the upper one side of the cavity 101, the primary dryer 100 for drying by adding a microwave and hot air to the sludge in which the microwave generator 106 is installed; And After being supplied to the drying chamber 204 of the steam jacket 201 continuously connected through the primary dryer 100, the steam is discharged to the outside via the inside of the steam jacket 201 by the rotary transfer member 210 in sequence. It is configured to include; secondary dryer 200 for drying by adding a microwave, hot air, steam to the sludge to be combined Microwave that changes the shape of the microwave to be irradiated at the tip of the cavity 101 on the side of the microwave generator 106 of the primary dryer 100 so that the microwave can be uniformly irradiated to the sludge without being concentrated anywhere Wastewater sludge drying apparatus comprising a microwave, characterized in that the transducer 108 is installed. The method according to claim 3 or 4, The microwave generator 106 and the microwave transducer 108 installed in the cavity 101 are alternately installed on both sides of the cavity 101 continuously installed so that microwaves are uniformly irradiated to the sludge. Sewage sludge drying apparatus comprising. A primary dryer (100) mounted on the conveyor (105) to dry by adding microwaves and hot air to the sludge discharged to the outside while passing through the plurality of cavities (101) connected continuously; And A plurality of steam jackets 201 are continuously installed in communication with each other, and a waveguide 206 for irradiating microwaves downward is installed at an inner center of the steam jacket 201, and one side is disposed outside the waveguide 206. Rotating carrier 210 for transporting and discharging the sludge supplied to the drying chamber 204 of the steam jacket 201 through the inlet 103 to the other outlet 104 via the inside of each steam jacket 201 to the maximum amount. ) Is installed, the secondary dryer (200) for drying by applying a combination of microwave, hot air, steam to the sludge; Sewage water sludge drying apparatus comprising a microwave, characterized in that it comprises a. The method according to claim 6, Steam jacket 201 includes a microwave, characterized in that the hot steam is supplied to the heat transfer to the sludge via the drying chamber 204 to the lower side of the space between the inner, outer wall 202, 203 of the dual structure Sewage sludge drying equipment. The method according to claim 6, The waveguide 206 is formed with a plurality of irradiation holes 207 in a zigzag form on both sides of the bottom to uniformly irradiate microwaves to the sludge transported along the bottom of the drying chamber 204, and is radiated through the irradiation holes 207. Microwave is a wastewater sludge drying apparatus comprising a microwave, characterized in that concentrated in the lower sludge by a reflecting plate 208 installed for registration on both sides of the waveguide (206). The method according to claim 6, Rotating carrier 210 has a plurality of transfer blades 212 radially installed on the outside of the rotating body 211 to rotate the sludge in a quantitative manner, the inner wall of the rotating body 211 and the steam jacket (201) ( Sewage sludge drying apparatus comprising a microwave, characterized in that for forming a sludge transport path (215) between the 202. The method according to claim 9, The sludge transport path 215, which is a transport path of the sludge, includes microwaves which are discharged to the outside through the exhaust part 218 on the other side after high temperature hot air is supplied through the air supply unit 217 formed on one outer wall. Sewage sludge drying equipment. The method according to claim 6, And a ribbon mixer-type tertiary dryer (300) for finally drying the sludge that has passed continuously through the first and second dryers (100, 200) in combination with hot air, steam, and microwaves. Sewage water sludge drying apparatus comprising a microwave.