KR20180107435A - Double pipe type heat exchanging system for heating anaerobic digester - Google Patents

Abstract

Disclosed is a dual pipe heat exchange device. According to an aspect of the present invention, provided is a dual pipe heat exchange device which comprises: a first pipe unit having a dual pipe structure including an outer pipe and an inner pipe disposed in the outer pipe, and having a structure in which a heat transfer material is transferred through a space between the outer pipe and the inner pipe by being connected to each other in plural while sludge is transferred through the inside of the inner pipe; and a second pipe unit connected between the plurality of first pipe units for transferring the sludge transferred through the inner pipe of the first pipe unit at the top to the inner pipe of another first pipe unit at the bottom. The first pipe unit further comprises a gap maintaining part interposed between the outer pipe and the inner pipe.

Description

TECHNICAL FIELD [0001] The present invention relates to a double pipe type heat exchanging system for heating an anaerobic digester.

The present invention relates to a special double tube type heat exchange system for warming an anaerobic digestion tank, and more particularly, to a high strength ultrasound sludge destruction device and a hybrid anaerobic digestion and solubilization system of a double tube type heat exchanger which breaks organic substances contained in sludge and heat- .

Industrial development has led to an explosion of urban population. As a result, there is a steady increase in proportion to the number of household sewage in the city. As a result, new and expanded sewage treatment plants for treating domestic wastewater are being continuously carried out in urban and suburban areas.

There are many sewage treatment methods applied to domestic sewage treatment plants, but there are activated sludge methods mainly applied.

The activated sludge process is a biological sewage treatment method and has advantages of relatively simple processes, and it is one of the sewage treatment methods most commonly applied to domestic sewage treatment plants due to accumulated experience.

However, the activated sludge method has been constantly addressing how to treat the excess sludge generated during the sewage treatment process. In particular, according to the industry demand for the treatment of the excess sludge in the sewage treatment process, Research and development is urgent.

Further, the microorganisms used in the activated sludge process can attain a sufficient reproductive rate and digestion efficiency when the proper temperature is maintained, but when the temperature of the outside air is low as in winter, the reproductive rate of the microorganisms is drastically lowered, there was. In particular, in countries where four seasons are clear, such as Korea, it is necessary to change the operation of sewage treatment plants according to seasons. For example, when the temperature of the outside air is low, nitrification is not sufficiently performed in the sludge reaction tank, and NH ₄ - N concentration in the treated water is increased. As a result, the T - N is increased, There was a problem that I could not satisfy. Furthermore, when treated water is used as a heat source such as a heat pump, there is a problem that it is difficult to satisfy such a water quality standard even though a better water quality is required. In addition, the sludge contained in sewage or treated water not only lowers the heat transfer rate of the heat exchanger but also causes corrosion of the pipe constituting the heat exchanger, thereby shortening the life cycle of the heat exchanger.

Korean Patent Registration No. 10-0745201 (Aug. 1, 2007, Sludge Reduction Apparatus of Anaerobic Digester) Korean Patent Publication No. 10-2010-0026643 (2010.03.10, digested tank for sludge reduction)

The embodiments of the present invention can provide a hybrid anaerobic digestion and solubilization system of a high strength ultrasonic sludge destruction apparatus and a double pipe type heat exchanger which can generate cavitation by irradiating ultrasonic waves to sludge to destroy organic matter contained in the sludge.

According to one aspect of the present invention, there is provided a double tube type structure including an inner tube disposed inside an outer tube and an outer tube, a plurality of tubes connected to each other, a heat transfer material is transferred through a space between the outer tube and the inner tube, And the sludge conveyed through the inner pipe of the upstream first pipe unit is conveyed to the inner pipe of another downstream first pipe unit connected between the plurality of first pipe units to convey the sludge through the inner pipe of the upstream first pipe unit Wherein the first pipe unit further comprises a gap retaining portion interposed between the outer pipe and the inner pipe.

According to another aspect of the present invention, there is provided a sludge treatment apparatus comprising: a sludge reaction tank for introducing sewage from the outside and decomposing organic substances contained in sewage using microorganisms; a sedimentation tank for sedimenting sewage having passed through a sludge reaction tank, A sludge processing line for transferring the sludge discharged from the settling tank, a digester for decomposing the sludge transferred through the sludge processing line using anaerobic microorganisms, a digester for generating biogas, and a digester A dehydrator for dehydrating and discharging coarse sludge, a conveying sludge circulation line branched from the sludge processing line and connected to the sludge reaction tank, an excess sludge circulation line branched from the sludge processing line and connected to the sludge reaction tank, and an excess sludge circulation line, The organic material contained in the sludge is destroyed and the sludge And a first sludge solubilizing device for supplying a carbon source to the sludge reaction tank by heating the solubilized sludge to be solubilized. The first sludge solubilizing apparatus includes a high strength ultrasonic sludge destruction apparatus for destroying organic substances contained in the sludge by using ultrasonic waves and a double tube according to the first claim for heating the sludge through the high strength ultrasonic sludge destruction apparatus by heat exchange. Type heat exchanger.

According to the embodiments of the present invention, by operating the ultrasonic sludge destruction device and the double pipe type heat exchange device in conjunction with each other, it is possible to reduce the influence on the temperature in the process design and to shorten the hydraulic retention time. As a result, It is possible to reduce the initial investment cost of the sewage treatment plant.

1 is a view showing a hybrid anaerobic digestion and solubilization system according to an embodiment of the present invention.
FIG. 2 is a schematic view of a double-tube heat exchanger according to an embodiment of the present invention.
3 is a cross-sectional view of a double-tube heat exchanger according to an embodiment of the present invention.
FIG. 4 is a view showing a part of a dual pipe type first pipe unit according to an embodiment of the present invention.
5 is a reference view for explaining a method of obtaining a volume of a double pipe type first pipe unit in a double pipe type heat exchange apparatus according to an embodiment of the present invention.
FIG. 6 is an operation example showing heat transfer performance using a double-tube heat exchanger according to an embodiment of the present invention.
7 is a view showing a part of a first pipe unit in a double pipe type heat exchange apparatus according to another embodiment of the present invention.
8 is a cross-sectional view of a first pipe unit in a double pipe type heat exchanger according to another embodiment of the present invention.
9 is a photograph illustrating a cross-sectional shape of a first pipe unit in a dual-pipe heat exchanger according to another embodiment of the present invention.
10 is a view showing a high strength ultrasonic wave sludge destruction apparatus according to an embodiment of the present invention.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, when a component is referred to as "comprising ", it means that it can include other components as well, without excluding other components unless specifically stated otherwise. Also, throughout the specification, the term "on" means to be located above or below the object portion, and does not necessarily mean that the object is located on the upper side with respect to the gravitational direction.

Furthermore, the term " coupled " does not mean that only a physical contact is made between the respective components in the contact relation between the respective constituent elements, but the other components are interposed between the respective constituent elements, It should be used as a concept to cover until the components are in contact with each other.

The sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a preferred embodiment of an escape direction guiding device according to the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals designate corresponding or corresponding components, A duplicate description will be omitted.

1 is a view showing a hybrid anaerobic digestion and solubilization system according to an embodiment of the present invention.

1, the hybrid anaerobic digestion and solubilization system according to an embodiment of the present invention may include a sludge reaction tank 10, a settling tank 20, a concentration tank 30, a digester 40, and a dehydrator 50 .

The sludge reaction tank 10 can receive the sewage introduced from the outside, and can decompose organic substances contained in the sewage using microorganisms.

The settling tank 20 can receive the sewage that has passed through the sludge reaction tank 10, and the sewage can be settled and separated into treated water and sludge.

The treated water separated and discharged from the sedimentation tank 20 can be transferred or discharged through the treated water treatment line L1 and the sludge separated and discharged from the sedimentation tank 20 is discharged to the digester 40 through the sludge treatment line L2 Lt; / RTI >

The high-strength ultrasonic wave sludge destruction apparatus 100 and the first waste heat recovery apparatus 300a may be installed in the treated water treatment line L1.

The high strength ultrasonic wave sludge destruction apparatus 100 installed in the treated water treatment line L1 not only improves the treated water quality by reducing the amount of sludge in the treated water, but also raises the temperature so that the first waste heat recovery apparatus 300a is provided with a stable heat source Can be provided. The first waste heat recovery apparatus 300a can recover the waste heat of the treated water by heat exchange. To this end, the first waste heat recovery apparatus 300a may include a heat pump using a heat exchanger and waste heat.

In the sludge treatment line (L2), the conveying sludge circulation line (L3) may branch and be connected to the sludge reaction tank (10). The sludge transferred to the sludge reaction tank 10 through the return sludge circulation line L3 can maintain the microbial concentration in the sludge reaction tank 10 at an appropriate level.

In the sludge treatment line (L2), an excess sludge circulation line (L4) may be additionally branched in addition to the conveyance sludge circulation line (L3) and connected to the sludge reaction tank (10). The excess sludge circulation line L4 differs from the transport sludge circulation line L3 in that the first sludge solubilizer 60a is installed.

The first sludge solubilizer 60a can supply the carbon source to the sludge reactor 10 by destroying the organic substances contained in the sludge transferred through the excess sludge circulation line L4 and heating and solubilizing the sludge, The microbial activity in the sludge reaction tank 10 can be enhanced by keeping the microbial cell 10 at an appropriate temperature even in the winter when the outdoor air temperature is low.

The concentration tank 30 may be installed in the sludge treatment line L2. That is, the sludge transferred through the sludge processing line (L2) can be transferred to the digester (40) after being concentrated to a high concentration in the concentration tank (30).

In the sludge processing line L2, in addition to the conveying sludge circulation line L3 and the surplus sludge circulation line L4, a concentrated sludge circulation line L5 may be branched and connected to the sludge reaction tank 10. The concentrated sludge circulation line L5 conveys the concentrated sludge to the high concentration while passing through the thickener 30 and the return sludge circulation line L3 and the excess sludge circulation line L4).

The second sludge solubilizer 60b can supply the carbon source to the sludge reactor 10 by destroying the organic substances contained in the sludge transferred through the concentrated sludge circulation line L5 and heating and solubilizing the sludge, The microbial activity in the sludge reaction tank 10 can be enhanced by keeping the microbial cell 10 at an appropriate temperature even in the winter when the outdoor air temperature is low.

The digester 40 can decompose the sludge transferred through the sludge processing line L2 using anaerobic microorganisms and generate biogas. The biogas generated in the digester 40 may be supplied to a heat energy consumer and utilized as an energy source.

A digester sludge circulation line L6 may be formed in the digester 40 to transfer the sludge stored in the lower portion of the digester 40 to the upper portion of the digester 40.

A third sludge solubilizer 60c may be installed in the digester sludge circulation line L6.

The third sludge solubilizer 60c not only can supply the carbon source to the digester 40 by destroying the organic material contained in the sludge transferred through the digester sludge circulation line L6 and heating and solubilizing the sludge, Can be maintained at an appropriate temperature even in the winter when the outdoor air temperature is low, so that the microbial activity in the digestion tank 40 can be enhanced. As a result, the digestion efficiency can be improved by promoting the nitrification action by the organic action of the microorganisms whose activity is increased, and the temperature of the digestion tank 40 can be kept constant, thereby reducing the overall operation cost including the digester 40 have.

The sludge that has passed through the digester 40 can be transferred to the dehydrator 50 via the digester sludge discharge line L7.

The digester sludge discharge line L7 may include an internal circulation line and the high-strength ultrasound sludge destruction apparatus 100 and the second waste heat recovery apparatus 300b may be installed in the internal circulation line of the digester sludge discharge line L7 have.

The high strength ultrasonic sludge destruction apparatus 100 installed in the digester sludge discharge line L7 not only can reduce the amount of sludge but also can raise the temperature to provide a stable heat source to the second waste heat recovery apparatus 300b. The second waste heat recovery apparatus 300b not only recovers the waste heat of the sludge by heat exchange but also reduces the temperature of the sludge and supplies it to the dehydrator 50 thereby reducing the volume of the sludge due to the temperature drop, The dehydration efficiency can be improved. The second waste heat recovery apparatus 300b may include a heat pump using a heat exchanger and waste heat.

The digested sludge discharge line L7 may be connected to a concentrated sludge discharge line L8 branched from the sludge processing line L2. That is, some of the sludge that has passed through the thickening tank 30 can be transferred to the dehydrator 50 through the concentrated sludge discharge line L8 without passing through the digestion tank 40.

The concentrated sludge discharge line L8 may be provided with a high-strength ultrasonic sludge destruction apparatus 100 and a third waste heat recovery apparatus 300c.

The high strength ultrasonic sludge destruction apparatus 100 installed in the concentrated sludge discharge line L8 not only can reduce the amount of sludge but also raise the temperature to provide a stable heat source to the third waste heat recovery apparatus 300c. The third waste heat recovery apparatus 300c not only can recover the waste heat of the sludge by heat exchange but also reduces the temperature of the sludge and supplies it to the dehydrator 50 to reduce the volume of the sludge due to the temperature drop, The dehydration efficiency can be improved. The third waste heat recovery apparatus 300c may include a heat pump using a heat exchanger and waste heat.

The dehydrator 50 can dehydrate the sludge transferred through the digester sludge discharge line L7 and discharge it to the outside. The sludge discharged from the dehydrator 50 may be discharged to the outside in the form of a dehydrated cake to be incinerated or buried, or utilized for land improvement.

The first to third sludge solubilizers 60a, 60b and 60c may include a high-strength ultrasonic sludge destruction apparatus 100 and a double-tube heat exchanger 200, which will be described in detail later.

Meanwhile, a valve, for example, a three way valve (not shown) is installed at a branch point of all or some of the lines L1 to L8 constituting the hybrid anaerobic digestion and solubilization system according to an embodiment of the present invention And a pump (not shown) may be installed in each of all or some of the lines L1 to L8 to generate a pressure necessary for transferring treatment water or sludge. In addition, the hybrid anaerobic digestion and solubilization system according to an embodiment of the present invention is a control device for automatically controlling components such as a valve, a pump, etc. constituting the system according to operating conditions such as sludge characteristics, microbial activity, (Not shown).

FIG. 2 is a schematic view of a dual-pipe heat exchanger according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view of a dual-pipe heat exchanger according to an embodiment of the present invention.

2 and 3, a dual pipe heat exchanger 200 according to an embodiment of the present invention includes a first pipe unit 210 and a second pipe unit 220, and the first pipe unit 210 May include an outer tube 211, an inner tube 212, and a gap retaining portion 213.

The first pipe unit 210 is a double pipe structure including an outer pipe 211 and an inner pipe 212 disposed inside the outer pipe 211. Accordingly, a plurality of different fluids can flow in the same or opposite directions through the space between the outer tube 211 and the inner tube 212 and the space inside the inner tube 212, respectively.

Referring to FIGS. 2 and 3, the first pipe unit 210 has a U-shaped structure and can be divided into a straight section S and a curved section C as a whole. The straight section S of the first pipe unit 210 may be constructed by assembling an intuitive pipe mainly and the curved section C may be formed by assembling a curved pipe such as an elbow type or a C type, These pipes are manufactured separately and assembled according to design conditions. Therefore, the dual tube type heat exchanger of the present embodiment is very excellent in expandability of heat exchange capacity. In addition, the plurality of U-shaped first pipe units 210 can be connected to each other through a coupling structure such as a flange, thereby allowing the length of the flow path through which the sludge passes to be actively expanded. In this case, the heat transfer material can be transferred through the empty space between the outer tube 211 and the inner tube 212, and the sludge can be transferred through the inner space of the inner tube 212.

The second pipe unit 220 is a medium structure for connecting the plurality of first pipe units 210 to each other. The second pipe unit 220 is a single pipe 221 structure connected to the inner pipe 212 of the first pipe unit 210.

The second pipe unit 220 is disposed between the plurality of first pipe units 210 so that the sludge conveyed through the inner pipe of the first pipe unit 210 on the upstream side flows into the second pipe unit 210 on the downstream side of the first pipe unit 210 It can have a linking function to transfer it to the inner pipe. 3, the second pipe unit 220 has a coupling relationship (for example, a coupling structure using a flange) that can be easily coupled to or separated from the first pipe unit 210, The inner pipe 212 of the first pipe unit 210 can be visually confirmed by separating the second pipe unit 220 when necessary. Also, sludge of high concentration is conveyed through the inner pipe 212 of the first pipe unit 210, and since such sludge is a highly viscous substance, there is a high possibility of sticking to the inside of the inner pipe 212. Accordingly, if necessary, the inside of the first pipe unit 210 can be identified by separating the second pipe unit 220, so that it is very easy to maintain and manage the pipe units 210 and 220.

The first pipe unit 210 is provided with an inflow flange 216 and a discharge flange 217 to inject or discharge the heat transfer material into the space between the outer pipe 211 and the inner pipe 212 of the first pipe unit 210. [ May be provided. The inlet flange 216 may be arranged in the circumferential direction at the outer periphery of the outer tube 211 to allow the external heat transfer material to flow into the space between the outer tube 211 and the inner tube 212 of the first pipe unit 210 . The discharge flange 217 is disposed in the circumferential direction at the outer periphery of the outer tube 211 and is disposed in the space between the outer tube 211 and the inner tube 212 of the first pipe unit 210, And discharges the heat transfer material to the outside. 3, the inlet flange 216 may be installed at one end of the outer tube 211 and the outlet flange 217 may be installed at the other end of the outer tube 211. [

Each of the inlet flange 216 and the outlet flange 217 can be coupled to the corresponding outlet flange 217 of the adjacent first pipe unit 210 and the inlet flange 216 via fastening means such as bolts and nuts . Thus, the heat transfer material flowing within one first pipe unit 210 can flow through the discharge flange 217 and the inlet flange 216 to another adjacent first pipe unit.

A first connection flange 218 is formed at both ends of the inner pipe 212 so that the inner pipe 212 of the first pipe unit 210 communicates with the single pipe 221 of the second pipe unit 220 And a second connection flange 228 may be provided at each end of the single pipe 221. [ Since the double pipe type first pipe unit 210 and the single pipe type second pipe unit 220 both have a C-shaped or U-shaped tubular shape, each corresponding first connecting flange 218 and the second connecting flange 218, (228), it is possible to carry out the continuous transfer of the sludge. Also in this case, the first connection flange 218 and the second connection flange 228 can be coupled through fastening means such as bolts and nuts.

FIG. 4 is a view showing a part of a dual pipe type first pipe unit according to an embodiment of the present invention. 4, a spacing portion 213 is additionally provided to keep the distance between the outer pipe 211 and the inner pipe 212 of the first pipe unit 210 constant.

The gap holding portion 213 may be a bar-shaped member protruding in the circumferential direction from the outer periphery of the inner pipe 212 toward the inner periphery of the outer pipe 211, for example. At least two spacers 213 may be provided in the center of the inner tube 212 in the direction of 360 degrees.

In particular, the interval maintaining portion 213 is mainly provided in a region where the straight section S and the curved section C of the first pipe unit 210 are in contact with each other. The reason why the gap holding portion 213 is disposed in the region where the straight section S and the curved section C of the first pipe unit 210 are in contact with each other is that the gap between the outer tube 211 and the inner tube 212 The volume of the space between the outer tube 211 and the inner tube 212 (the volume at this time is the outer diameter of the inner tube in the volume v2 calculated based on the inner diameter D2 of the outer tube as described later Which is substantially the same as the volume difference (v2-v1) obtained by subtracting the volume (v1) calculated on the basis of the interval holding section 213 (D1). That is, the interval between the outer tube 211 and the inner tube 212 is maintained while the number of the spacing portions 213 is minimized. As shown in Fig. 3, in the present embodiment, the interval maintaining section 213 is provided with one on the upper region of a pair of straight line sections S extending in parallel in the horizontal direction at both ends of the curved section C There is an advantage that the above-mentioned effect can be expected merely by being installed.

In addition, it is very difficult in actual practice to provide the space maintaining portion 213 in a very narrow space between the outer tube 211 and the inner tube 212. This is because the space holding portion 213 is divided into the straight section S The interval holding portion 213 can be more easily provided in a very narrow space between the outer tube 211 and the inner tube 212 by disposing it in the region where the curved portion C is in contact. Particularly, in the double pipe type heat exchanger of the present embodiment, the gap between the outer tube 211 and the inner tube 212 is formed within a range of 1.5 mm to 2.5 mm. In order to maintain such a narrow gap, Assembly process is required. In this case, when the interval maintaining section 213 is disposed in an area where the straight section S and the curved section C are in contact with each other, the pipe of the straight section S and the pipe of the curve section C are pre- When the pipe of the straight section S and the pipe of the curved section C are integrated with each other, it is possible to complete the installation by interposing the gap holding section 213 therebetween, The fabrication of the first electrode 210 can be greatly facilitated.

In order to increase the easiness of assembly between the inner pipe 212 and the outer pipe 211, in the course of manufacturing the pipe of the straight section S or the pipe of the curved section C, To the end of the pipe of the section S or the end of the pipe of the section C of the curved section. Accordingly, when the interval maintaining portion 213 is provided in the region where the straight section S and the curved section C are in contact with each other, an additional welding process or the like can be omitted.

The first pipe unit 210 of this embodiment is manufactured such that the interval between the outer pipe 211 and the inner pipe 212 is formed within a range of 1.5 mm to 2.5 mm. As described above, the distance between the outer pipe 211 and the inner pipe 212 in the first pipe unit 210 is in the range of 1.5 mm to 2.5 mm (in this specification, the embodiment of the product manufactured to keep the gap at 2 mm) So that the volume of the double pipe type can be minimized. As a result, the double pipe type heat exchange device of the present embodiment can be manufactured to be compact as about 1/2 of the conventional one. In particular, heat transfer materials such as hydrothermal fluids are much less viscous than highly viscous sludge, so they can deliver more heat at the same time compared to the same amount of sludge. Therefore, in the embodiments of the present invention, the volume D2 between the inner diameter D2 of the outer tube 211 and the outer diameter D2 of the inner tube 212 is maintained at the same level as the inner diameter of the inner tube 212 for transferring the sludge, D1) is minimized, it is possible to manufacture the product compact in size while maintaining the conventional heat transfer (heat exchange) performance.

5 is a reference view for explaining a method of obtaining a volume of a double pipe type first pipe unit in a double pipe type heat exchange apparatus according to an embodiment of the present invention.

5, the volume of the space between the outer tube 211 and the inner tube 212 is calculated by taking the volume v2 calculated on the basis of the inner diameter D2 of the outer tube as the volume calculated on the basis of the outer diameter D1 of the inner tube (v2-v1), which is a value obtained by subtracting (v1), that is, the volume difference (v2-v1). The volume difference v2-v1 which is the difference between the volume of the outer tube 211 and the volume of the inner tube 212 can be calculated as the volume of the heat transfer material flowing in the space between the outer tube 211 and the inner tube 212 have.

The volume of the cylindrical inner pipe 212 and the volume of the cylindrical outer pipe 211 can be calculated by using the following equation 1 and the volume difference v2-v1 ) Can be calculated.

[Equation 1]

Where v is the volume of the cylinder, Π is the circularity, r is the radius of the cylinder, and h is the length of the cylinder.

The volume of the inner pipe 212 is calculated by referring to Equation (1).

&Quot; (2) "

Where D1 is the radius of the inner tube 212 and H is the inner diameter of the inner tube 212 and the inner diameter of the inner tube 212 is the inner diameter of the inner tube 212. [ Lt; / RTI >

Next, referring to Equation 1, the volume of the appearance 211 is expressed by Equation 3 below.

&Quot; (3) "

V2 is the radius of the outer tube 211 and H is the inner diameter of the outer tube 211 and the inner diameter of the outer tube 211 is D2 / Lt; / RTI >

Accordingly, the volume, that is, the volume difference (v2-v1) of the heat transfer material flowing in the space between the outer tube 211 and the inner tube 212 can be calculated. In this embodiment, the volume difference (v2-v1) calculated through Equations 1 to 3, that is, the volume of the heat transfer material is the volume of the inner tube 212 calculated based on the inner diameter of the inner tube 212, The diameter of the outer tube 211 may be reduced to 20% to 100% in relation to the volume. For reference, when the calculated volume difference (v2-v1) is 100% of the volume of the inner tube 212 calculated on the basis of the inner diameter of the inner tube 212, it means that the volume of the heat transfer material and the volume of the sludge are the same .

The diameter of the outer tube 211 is reduced and the distance between the outer tube 211 and the inner tube 212 is in the range of 1.5 mm to 2.5 mm in such a state that the inner diameter of the inner tube 212 remains unchanged. 1 pipe unit 210, since the viscosity of the liquid phase heat transfer material is very low compared to the high viscosity sludge, the heat transfer performance of the heat transfer material can be maintained through the circulation of the heat transfer material more rapidly. It is also possible to determine to what extent the temperature of the sludge is raised or lowered according to the field conditions by controlling the circulation rate of the heat transfer material circulating through the space between the outer tube 211 and the inner tube 212.

FIG. 6 is an operation example showing heat transfer performance using a double-tube heat exchanger according to an embodiment of the present invention. Referring to FIG. 6, it can be confirmed that the temperature of the sludge conveyed to the anaerobic digestion tank is efficiently heated by using the dual-pipe heat exchanger of the present embodiment. That is, in a state where the final heating temperature (38 ° C) of the sludge entering the inside of the anaerobic digestion tank and the hot water supply temperature (70 ° C) of the boiler introduced into the double-tube heat exchanger 200 of this embodiment are kept constant , It can be confirmed that the temperature of the sludge can be adjusted only by the double pipe type heat exchanger 200.

FIG. 7 is a view showing a part of a first pipe unit in a dual pipe heat exchanger according to another embodiment of the present invention, and FIG. 8 is a cross-sectional view of a double pipe heat exchanger according to another embodiment of the present invention, FIG. 9 is a photograph illustrating a cross-sectional shape of the first pipe unit in the dual pipe heat exchanger according to another embodiment of the present invention. FIG.

7 to 9, the same or corresponding portions as those of the double-tube heat exchanger according to the above-described embodiment will not be described in detail. In the embodiment of the present invention, We will focus on the different parts from the configuration.

7 through 9, a dual pipe heat exchanger 201 according to another embodiment of the present invention includes a first pipe unit 210 and a second pipe unit 220, and the first pipe unit 210 May further include a plurality of protrusions 214 formed along the surface of the inner tube 212 including the outer tube 211 and the inner tube 212 and the gap retaining portion 213.

The protrusion 214 may have a circular groove structure protruding toward the inside or outside of the inner tube 212. In the case of the drawing, the protrusion 214 is shown as a structure protruding (recessed in the drawing) toward the inside of the inner tube 212. 7, a plurality of protrusions 214 are formed radially so as to be spaced apart from each other along the circumferential surface of the inner tube 212, and the remainder are spaced from each other along the longitudinal direction of the inner tube 212 Can be confirmed.

8, a plurality of protrusions 214 are formed to protrude from the surface of the inner tube 212, thereby causing a flow phenomenon similar to that of the intestinal tract to the sludge transferred through the inner space of the inner tube 212 . This flow has the advantage that the solidified sludge, which is likely to stick to the inner surface of the inner tube 212, can be cleaned cleanly.

Particularly, by projecting protrusions 214 repeatedly at regular intervals along the surface of the inner tube 212, the inner cross-sectional shape of the inner tube 212 has a repetitive pattern of circular and triangular shapes as shown in Fig. 8 . Therefore, when the sludge is transported through the inner space of the inner pipe 212, the protrusion 214 is omitted and the sludge flows relatively slowly in the section where the inner diameter of the inner tube 212 is widened And the protrusion 214 is provided so that the sludge flows in the inner tube 212 by repeating the shape in which the inner diameter of the inner tube 212 is narrowed (that is, the section having a triangular cross section) It is possible to expect an effect of cleaning the inner side wall of the case.

The center distance I between the protrusions 214 formed to be spaced along the longitudinal direction of the inner tube 212 is larger than the diameter D3 of the protrusion 214 and smaller than the outer diameter D1 of the inner tube 212 .

Although the inner tube 212 has a substantially triangular shape due to the protrusion 214 in FIGS. 7 to 9, this is merely one example. As another example, the inner tube 212 may have a cross-sectional shape Can be deformed into various shapes such as the shape of a naked clover.

10 is a view showing a high strength ultrasonic wave sludge destruction apparatus according to an embodiment of the present invention.

Referring to FIG. 10, a high-strength ultrasonic wave sludge destruction apparatus 100 according to an embodiment of the present invention may include a plurality of pipes 110 and an ultrasonic generator 120.

The plurality of pipes 110 may be connected to each other in series. For example, the sludge or process water may be introduced first through the front end of the pipe 110, and the rear end of the first disposed pipe 110 may be connected to the front end of the second disposed pipe 110 And the rear end of the second disposed pipe 110 may be connected to the tip of the third disposed pipe 110. [ The ultrasonic treated sludge or treated water may be discharged through the rear end of the pipe 110 disposed last and supplied to the double pipe type heat exchange apparatus 200 or waste heat recovery apparatuses 300a, 300b and 300c.

The plurality of pipes 110 may alternately extend in an upward sloping direction with respect to the horizontal direction and the horizontal direction. In this case, the tip of the pipe 110 extending in the upward inclined direction among the plurality of pipes 110 may be disposed at the lower end of the pipe 110. That is, the sludge or treated water can form a rising flow in the pipe 110 extending in the upward sloping direction among the plurality of pipes 110. As another example, the plurality of pipes 110 may be horizontally spaced apart from each other in the vertical direction. In this case, the plurality of pipes 110 can be arranged so that sludge or process water can be transported in opposite directions in two adjacent pipes 110. As another example, the plurality of pipes 110 may be vertically spaced apart from each other in the horizontal direction. In this case, the tip of the pipe 110 may be disposed at the lower end of the pipe 110. That is, the sludge or treated water can form a rising stream in the plurality of pipes 110. Compared with the conventional case in which a plurality of pipes 110 are arranged as described above, it can be confirmed through experimental data that the sludge treatment efficiency is improved.

An inlet 130 which is a passage through which sludge or process water flows can be connected to the tip of the pipe 110 disposed first in the plurality of pipes 110. At the rear end of the pipe 110 disposed at the end, Or a discharge unit 140, which is a path through which treated water is discharged. In addition, a drain portion 150, which is a passage for discharging sludge or process water filled in a plurality of pipes 110, may be coupled to a rear end of the pipe 110 disposed first in the plurality of pipes 110. The drain part 150 may be provided with an on-off valve (not shown) for opening and closing the drain part 150.

The ultrasonic generator 120 is installed in each of the plurality of pipes 110 and can irradiate ultrasonic waves to sludge or treated water transferred through the pipe 110. Specifically, the ultrasonic generator 120 may be installed at a rear end of the pipe 110 to irradiate ultrasound waves in the longitudinal direction of the pipe 110 toward the tip of the pipe 110 into which the sludge or the process water flows. That is, the ultrasonic waves can be irradiated in the direction opposite to the conveying direction of the sludge or the treated water.

Ultrasonic waves irradiated from the ultrasonic generator 120 may cause cavitation in the sludge to destroy the organic substances contained in the sludge. The sludge is able to generate micro-bubbles while repeating compression and expansion by cavitation, and the micro-bubbles thus generated gradually grow by repeating compression and expansion by cavitation. The fine bubbles grown to a certain size can no longer grow and explode, and the high heat energy and pressure that are emitted can destroy the cell membrane of the organic material contained in the sludge. Therefore, the sludge can be reduced by solubilizing the refractory organic material, and the intracellular material flowing out from the organic material can increase the proliferation and activity of the microorganism. In particular, the sludge treatment efficiency can be improved by irradiating ultrasonic waves to the sludge which has passed through the thickener 30.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

L1: treated water treatment line L2: sludge treatment line
L3: conveying sludge circulation line L4: surplus sludge circulation line
L5: Concentrated sludge circulation line L6: Digested sludge circulation line
L7: Digested sludge discharge line L8: Concentrated sludge discharge line
10: sludge reaction tank 20: settling tank
30: Enrichment tank 40: Digester
50: Dehydrator 60a, 60b, 60c: Sludge solubilizer
200, 201: Double pipe type heat exchanger 210: First pipe unit
211: Appearance 212: Inner pipe
213: spacing portion 214:
220: second pipe unit 221: single pipe

Claims (13)

And a plurality of heat transfer materials are transferred through the space between the outer tube and the inner tube and the sludge is introduced into the inner tube through the inner tube, A first pipe unit of a structure to be conveyed; And
And a second pipe unit connected between the plurality of first pipe units to transfer the sludge conveyed through the inner pipe of the first upstream pipe unit to the downstream inner pipe of the first pipe unit,
The first pipe unit includes:
Further comprising a gap retaining portion interposed between the outer tube and the inner tube.
The method according to claim 1,
Wherein the first pipe unit has a U-shaped structure that is divided into a straight section and a curved section,
Wherein the gap maintaining portion is provided in an area where the straight section and the curved section are in contact with each other.
The method according to claim 1,
The distance between the outer tube and the inner tube is 1.5 mm to 2.5 mm,
Wherein the volume of the heat transfer material flowing through the space between the outer tube and the inner tube is 20% to 100% of the volume of the inner tube calculated based on the inner diameter of the inner tube.
The method according to claim 1,
The first pipe unit includes:
An inlet flange disposed in a circumferential direction at an outer periphery of the outer tube to introduce an external heat transfer material therein;
A discharge flange disposed in the circumferential direction at the outer periphery of the outer tube to discharge the heat transfer material to the outside; And
And a first connection flange disposed at both ends of the inner tube,
The second pipe unit includes:
Single tube; And
And a second connection flange disposed at both ends of the single pipe and connected to the first connection flange.
5. The method according to any one of claims 1 to 4,
Wherein the inner tube includes a plurality of protrusions formed along a surface thereof,
Wherein the protruding portion is protruded toward the inside or outside of the inner tube.
6. The method of claim 5,
Wherein a part of the plurality of protrusions are spaced apart from each other along a circumferential surface of the inner tube and the rest are spaced apart from each other along a longitudinal direction of the inner tube,
Wherein a center distance between protrusions spaced along the longitudinal direction of the inner tube is larger than a diameter of the protrusion and smaller than an outer diameter of the inner tube.
A sludge reaction tank for introducing sewage from the outside and decomposing the organic substances contained in the sewage using microorganisms;
A sedimentation tank for sedimenting the sewage having passed through the sludge reaction tank and separating and discharging the treated water and the sludge;
A treatment water treatment line for transferring treatment water discharged from the settling tank;
A sludge processing line for transferring the sludge discharged from the settling tank;
A digester capable of decomposing sludge transferred through the sludge processing line using anaerobic microorganisms and generating biogas;
A dehydrator for discharging dehydrated sludge through the digester;
A conveying sludge circulation line branched from the sludge processing line and connected to the sludge reaction tank;
An excess sludge circulation line branched from the sludge processing line and connected to the sludge reaction tank; And
And a first sludge solubilizer installed in the excess sludge circulation line for supplying a carbon source to the sludge reaction tank by destroying organic substances contained in the sludge and heating and solubilizing the sludge,
The first sludge solubilizing apparatus includes:
A high strength ultrasonic wave sludge destruction apparatus for destroying organic substances contained in sludge by using ultrasonic waves; And
The hybrid anaerobic digestion and solubilization system according to claim 1, further comprising a double pipe type heat exchanger according to claim 1 for heating the sludge having passed through the high strength ultrasonic wave sludge disruptor by heat exchange.
8. The method of claim 7,
A concentration tank installed in the sludge treatment line and concentrating the sludge;
A concentrated sludge circulation line for transferring sludge through the thickener to the sludge reaction tank; And
Further comprising a second sludge solubilizer installed in the concentrated sludge circulation line and having the same structure as the first sludge solubilizer.
8. The method of claim 7,
A digester sludge circulation line for transferring sludge stored in a lower portion of the digester to an upper portion of the digester; And
Further comprising a third sludge solubilizer installed in the digester sludge circulation line and having the same structure as the first sludge solubilizer.
8. The method of claim 7,
The high strength ultrasonic wave sludge destruction apparatus comprises:
A plurality of pipes connected in series with each other; And
And an ultrasonic generator installed in each of the plurality of pipes and irradiating ultrasonic waves to the sludge conveyed through the pipe,
Wherein the ultrasonic wave irradiated from the ultrasonic generator generates cavitation in the sludge to destroy the organic material contained in the sludge.
11. The method of claim 10,
Wherein the ultrasonic generator is installed at a rear end of the pipe and irradiates the ultrasonic wave in the longitudinal direction of the pipe toward the tip of the pipe into which the sludge flows.
11. The method of claim 10,
The plurality of pipes alternately extending in an upward sloping direction with respect to the horizontal direction and the horizontal direction,
Wherein a tip of the pipe extending in an upward sloping direction of the plurality of pipes is disposed at a lower end of the pipe.
11. The method of claim 10,
A first waste heat recovering device installed in the treated water treatment line and recovering waste heat of the treated water by heat exchange;
A digester sludge discharge line for transferring sludge through the digester to the dehydrator and having an internal circulation line;
A second waste heat recovery device installed in an internal circulation line of the extinguished sludge discharge line for recovering waste heat of extinguished sludge by heat exchange;
A concentrated sludge discharge line branched from the sludge treatment line and connected to the digested sludge discharge line; And
And a third waste heat recovery device installed in the concentrated sludge discharge line for recovering waste heat of the concentrated sludge by heat exchange,
Wherein the high strength ultrasonic wave sludge destruction apparatus is additionally installed in the treated water treatment line, the internal circulation line of the extinguished sludge discharge line, and the concentrated sludge discharge line, respectively.

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