KR100996951B1 - Apparatus for drying sludge - Google Patents

Abstract

PURPOSE: A sludge drying machine is provided to reduce energy for processing sludge. CONSTITUTION: A sludge drying machine comprises a mixing tank, a mixing screw, a mixer(100) consisting of transfer screw, an air supplier(200) feeding air to the mixing sludge, a conical shape chamber, a throttle inlet formed in the chamber floor, a caliber pipe located in the center of the chamber, a cyclone drier(300) which dries the mixing sludge sprayed to inside, a cyclone separator(400) discharging air and dry sludge to the bottom, a conveyor(500) transferring the dry sludge flowing in and re-dry, a distributor(600) outputting two kinds of dry sludge depending on the size of particles. The dry sludge with smaller particle is resupplied to the mixer.

Description

Apparatus for drying sludge

The present invention relates to a sludge drying apparatus, and more particularly, to a drying apparatus for drying the dehydrated dewatered sludge in a mechanical manner to reduce the water content.

The technology to remove moisture from waste material, that is, waste water sludge, is a process technology using a dehydrator, but it is very difficult to reduce the ratio of water contained in the sludge (hereinafter referred to as 'water content') to 80% or less by weight with conventional dehydration technology. it's difficult.

The total amount of sewage sludge produced annually in domestic sewage treatment plants operated by local governments is 2.4 million tons, discharging more than 70% to the sea. Due to marine pollution, marine dumping is expected to be totally banned.

In addition, the total amount of industrial wastewater sludge generated in factories is about 4.8 million tons per year, and the production of livestock and manure sludge is similar. Most of the wastewater sludge is discharged to the ocean like sewage sludge, 90% of the livestock manure is recycled from land to liquids, and the rest is discharged to the ocean.

Therefore, in order to solve such various sludge treatment problems, it is necessary to first reduce the total amount of generation. Above all, the reduction of water, which accounts for most of the sludge weight, is very important. It can be usefully used.

Most sewage treatment process including sewage consists of dewatering process, which is the final process technology.The mechanical dehydration device separates some of the free water in the water in the sludge by centrifugation or filter pressing, and the water content of about 80 ~ 85% is achieved. Eggplant drained into cake. That is, most of the final sludge weight occupies the residual water, which causes many environmental and economic difficulties in the treatment of the final sludge.

When the dewatered sludge is directly put into the drying facility, the sludge is not easily separated from each other due to the moisture and organic matter contained in the sludge. In addition, the sludge has high adhesiveness in the high water content range, resulting in low moisture reduction and low drying performance.

In particular, in the case of sewage, organic wastewater sludge, and livestock or human waste sludge classified as organic sludges, that is, the share of organic solids (Volatile solid) to total solids, that is, VS / TS ratio of 60% or more, The test results showed that the reduction performance was lowered. This is because, when the organic component is high, it is determined that the higher the water content is, the lower the water separability is due to the interaction with the contained moisture.

Therefore, in order to change the material state of the organic sludge, it is necessary to lower the inflow water or lower the organic component ratio, and the method may artificially adjust the component ratio of the material in the inflow sludge or apply thermal input such as combustion.

Here, the combustion of organic components due to thermal input causes high energy consumption and causes secondary environmental pollution such as VOC generation due to combustion.

Alternatively, in order to reduce energy, there is a method of adding a material containing a large amount of separate inorganic components (such as slaked lime) in the inflow stage of the one sludge, but there is an additional cost for these additives.

In order to solve such an overall problem, the present applicant has previously used the sludge drying apparatus using air transfer in Korean Patent Registration No. 10-0485223 (2005.4.15), without using a separate heat source. The device for drying has been applied for and registered.

Briefly, a sludge injector for supplying finely divided sludge by rotating the rotary wheel in the body frame; An air blower is connected to the lower part of the sludge injector and the upstream end of the sludge injector is connected to the upstream end, and the diameter of the urban type shortening tube, the air flow amplifier housing and the air flow amplifier housing, and the reduction of the diameter gradually decrease downstream thereof. An air transfer device to which an air flow amplifier including a first air inlet for supplying air to a space between the pipes is spoken; A plurality of vertical bars connected to the air conveying apparatus, the upper surface of which is inverted throttle inlet at the bottom of the cyclone chamber, an inner tube at the center of the cyclone chamber, and a second air inlet for supplying air to the side of the throttle inlet; Multistage cyclone dryer; An air supply header receiving air from the air blower and supplying air to the first air inlet and the second air inlet; A cyclone separator connected to a transfer pipe connected to the cyclone dryer and connected to an air discharge device for discharging residual air at an upper portion thereof, wherein sludge solids are collected at a bottom of a cyclone chamber; And an automatic discharge device connected to the lower portion of the cyclone separator to discharge dry solids.

However, there is a limit in reducing the moisture content of the final dry sludge because the moisture content of the original sludge is high even if dried in the air flow using a conventional cyclone dryer.

The present invention has been made to improve the problems of the prior art as described above, an object of the present invention is to recover the portion of the dry sludge discharged by drying the raw sludge, and mixed with the initial raw sludge to the mixed sludge put into the drying apparatus It is to provide a sludge drying apparatus which can lower the water content in advance and increase the weight of the dry solid to achieve effective water removal.

The present invention for achieving the above object, a dry sludge inlet and a raw sludge inlet is formed on the top and the mixed sludge discharge port is formed in the bottom, and a pair of dry sludge and the raw sludge is added while rotating inside the mixing tank A mixer consisting of a mixing screw for mixing sludge and a conveying screw disposed below the mixing screw to convey the mixed and mixed sludge to one side and discharged to the mixed sludge outlet; An air feeder to which the mixed sludge discharged from the mixer flows and injects the mixed sludge to inject the mixed sludge; A mixed sludge and air injected into the chamber including a conical chamber connected to the air supply unit, a throttle inlet formed at a bottom of the chamber, and an inner diameter tube located at the center of the chamber. A cyclone dryer for swirling flow to dry the mixed sludge; A cyclone separator connected to the cyclone dryer and configured to have a conical shape, wherein the air introduced into the cyclone separator is discharged to an upper portion and separated into a dry sludge at a lower portion; A near-infrared conveyor connected to the lower part of the cyclone separator and heated and re-dried while transporting the introduced dry sludge; A classifier for classifying the dry sludge flowing out of the near-infrared conveyor into two types according to the size of the particles and discharging each of the dry sludge, wherein the mixer is configured to recover dry sludge having relatively small particles from the dry sludge discharged to the classifier. It is characterized in that the resupply to.

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And the impeller of the mixing screw is characterized in that a plurality of stirring spatula radially coupled.

In addition, one side of the transfer screw is provided with a disk-shaped perforated plate having a plurality of perforated holes to be transported to the mixed sludge to be discharged into a plurality of strands through the perforated hole, one side of the perforated plate is provided with a rotary cutter It characterized in that the discharged by cutting the mixed sludge at a predetermined interval.

In addition, the near-infrared conveyor includes a conveyor body having an inlet and an outlet in which dry sludge separated from the cyclone separator is introduced, a screw conveyor for transporting dry sludge built into the conveyor body, and an upper side of the screw conveyor. A near-infrared lamp for irradiating near-infrared to dry sludge disposed and transported in the air, a reflector installed above the near-infrared lamp to reflect near-infrared light, and an exhaust gas coupled to an upper portion of the conveyor body to discharge water vapor generated from the dry sludge to the outside It is characterized by consisting of a duct.

The classifier may include an injection port into which dry sludge heated by the near-infrared conveyor is injected, a classification body having a first discharge port and a second discharge port formed to classify and discharge the injected dry sludge, and a flow path connecting the injection port and the first discharge port. It is characterized in that consisting of a classification plate for passing through only the dry sludge having a particle of a relatively small size.

Preferably, the one side of the mixer is characterized in that the dry sludge storage tank which is further controlled to collect and store a portion of the dry sludge discharged through the classifier and to put the amount into the mixer.

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Effects of the present invention by the above configuration is as follows.

Dry sludge which is finally recycled is significantly reduced in weight and water content is remarkably reduced compared with the conventional one, and the throughput is expanded under the same energy supply conditions, which is superior to the energy saving effect per sludge capacity.

1 is a flow chart of a sludge drying process according to an embodiment of the present invention.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a sludge drying apparatus.
Figure 3 is a structural diagram showing the internal structure of the dry sludge storage tank and the mixer of the present invention.
FIG. 4 is a partial sectional view taken along line AA ′ of the mixer shown in FIG. 3. FIG.
5 is a partial detail view of the transfer screw of the mixer shown in FIG.
Figure 6 is a structural diagram showing the structure of the near-infrared conveyor and classifier of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. The following description and the accompanying drawings are presented for the overall understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. And a detailed description of known configurations and functions that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a flow diagram of a sludge drying process according to a preferred embodiment of the present invention, Figure 2 is a block diagram showing the configuration of a sludge drying apparatus according to a preferred embodiment of the present invention.

Hereinafter, 'one sludge' refers to sludge before drying, where water content is about 80 to 85% by dehydration only, and 'dry sludge' refers to sludge dried through a dryer, and 'mixed sludge' refers to sludge and dry sludge. It means to mix. Also, 'Dry solid (DS)' means solid material except water in components such as raw sludge, dry sludge and mixed sludge, so that the weight of dry solid increases when the moisture content decreases in the total weight of sludge. .

The sludge drying apparatus of the present invention is a mixer 100, air blower 200, cyclone dryer 300, cyclone separator 400, near infrared conveyor 500, classifier 600, dry sludge storage It may be configured to include a tank 700, by mixing the raw (dewatered) sludge and dry sludge introduced from the dry sludge storage tank 700 in the mixer 100, by the air feeder 200 The mixed mixed sludge is sprayed on the cyclone dryer 300 to be dried mechanically, and the dried dry sludge is collected separately from the air in the cyclone separator 400, and the collected dry sludge is heated in the near infrared conveyor 500. And, it is sorted by the particle size in the classifier 600 is recovered and stored in the dry sludge storage tank 700 and a predetermined amount is added to the mixer 100 with the original sludge again to repeat do.

First, the mixer will be described with reference to FIGS. 3, 4, and 5 together. FIG. 3 is a structural view showing the internal structure of the dry sludge storage tank and the mixer of the present invention, FIG. 4 is a sectional view of a portion AA 'of the mixer shown in FIG. 3, It is also.

The mixer 100 is a device for mixing dry sludge with primary sludge, which is primarily dried to reduce water content, and may be composed of a mixing tank 120, a mixing screw 140, and a conveying screw 160.

The mixing tank 120 is a space in which mixing is performed, and a dry sludge inlet 124 into which dry sludge is injected is formed at one upper portion thereof, and one sludge inlet 122 into which one sludge is introduced is formed at the other side. In addition, a mixed sludge outlet 126 through which the mixed sludge mixed inside is discharged is formed at the bottom.

In addition, a pair of mixing screws 140 are provided in the mixing tank 120. The mixing screw 140 is disposed in parallel and horizontally and evenly mixed with the dry sludge and the original sludge.

The impeller 142 of the mixing screw 140 is provided with a flat stirring spatula 144, preferably a plurality of radially as shown in FIG. Each stirring spatula 144 is disposed so as not to collide with each other and is coupled to form a constant inclination on a right angle surface of the shaft in the same manner as the inclination angle of the impeller 142.

Therefore, while the mixing screw 140 rotates in different directions, the stirring spatula 144 mixes the dry sludge and the original sludge. In particular, the stirring spatula 144 rotates with an inclination, thereby applying a blow to the sludge. Each sludge is transported and blends well.

In addition, the conveying screw 160 is disposed below the mixing screw 140 and rotates to convey the mixed sludge to one side. The conveyed mixed sludge may be controlled by using an inverter in order to supply a fixed amount to the cyclone dryer 300 to be described later.

Power transmission connects the lower transfer screw 160 from one motor reducer to the chain sprocket, installs a double chain sprocket on the motor shaft, connects to the chain sprocket installed on any one of the upper mixing screws 140, and mixes each. The same spur gears can be installed in the screw to rotate in the opposite direction at the same rotational speed.

Preferably, the one end of the transfer screw 160 is provided with a disk-shaped perforated plate 162, as shown in Figure 5, the outer side of the perforated plate 162 may be provided with a rotary cutter 164.

A plurality of perforation holes 162a are formed in the perforated plate 162, and the rotary cutter 164 has a cutting edge. Therefore, the mixed sludge conveyed by the conveying screw 160 is discharged into long strands through the perforation hole 162a and simultaneously cut by the rotary cutter 164 at regular intervals to form pellets. Of course, pelletized mixed sludge size can be adjusted according to the rotation speed.

Next, the air blower 200, the cyclone dryer 300, and the cyclone separator 400 will be described. However, since the air blower 200, the cyclone dryer 300, the cyclone separator 400 is a known technique known by the present applicant will be briefly described.

The air blower 200 blows the air largely in a configuration in which the mixed sludge discharged from the mixer 100 is introduced to blow and supply air strongly to inject the mixed sludge into the cyclone dryer 300. ) And a flow rate amplifier 240 that amplifies the flow rate of air generated by the blower 220.

And the cyclone dryer 300 is a conical chamber connected to the air and mixed sludge from the air feeder 200 as shown in Figure 2, a plurality of vertical bars coupled to the upper portion of the chamber, A throttle inlet provided in a reverse conical shape at the bottom of the chamber, and an inner diameter tube disposed perpendicular to the center of the chamber on the upper side of the throttle inlet. Therefore, the introduced air and the mixed sludge collide with the vertical bar inside the chamber to turn spirally, and have turbulent flow (Vortex flow), and the velocity decreases as the sludge gradually decreases, so that the mixed sludge particles are reduced in size by collision and frictional heat is reduced. Generated and dried.

Preferably, the cyclone dryer 300 may be provided in multiple stages are arranged in plurality.

In addition, the cyclone separator 400 is connected to the cyclone dryer 300 and is formed in a conical shape, and an air outlet through which residual air is discharged is formed at the top, and dried sludge is collected at the bottom, which is the same principle as a dust collector. .

Next, the near-infrared conveyor will be described with reference to FIG. 6. 6 is a structural diagram showing the structure of the near-infrared conveyor and classifier of the present invention.

The near-infrared conveyor 500 is to further lower the moisture content of the dry sludge and is connected to the lower portion of the cyclone separator 400, and the conveyor body 510, screw conveyor 520, near-infrared lamp 530, reflector plate 540, The exhaust duct 550 may be configured.

Referring to FIG. 6, the conveyor body 510 has an elongated housing shape having a 'U' cross section, and has an inlet 512 and an outlet 514 through which dry sludge flows in and out, and the conveyor body 510. Inside the screw conveyor 520 is installed along the longitudinal direction and rotates to transport the dry sludge introduced into the inlet 512.

In addition, a plurality of near-infrared lamps 530 for irradiating near-infrared rays to dry sludge to be transported are installed inside the conveyor body 510 and above the screw conveyor 520, that is, above the near-infrared lamps 530. A stainless reflector 540 is provided on an upper surface of the conveyor body 510 to reflect near infrared rays. A heat sink may be provided on the outside of the reflective plate 540 to prevent heat from being emitted.

In addition, an exhaust duct 550 may be provided to communicate with the upper portion of the conveyor body 510 through which an exhaust duct generated by heating in the conveyor body 510 may escape, and the exhaust duct 550 may be an exhaust fan. (Not shown).

For reference, the steam sucked by the exhaust fan includes some odor components and is connected to the cleaning tower 800 shown in FIG. 2 to remove odors.

The classifier 600 will be described with reference to FIG.

The classifier 600 is a dry sludge injected by the dry infrared in the near-infrared conveyor 500 by lowering the moisture content is injected to classify by the size of the particles, the classification body 620 and the classification plate 640 Can be configured.

The classification body 620 has a shape similar to that of the 'Y' is arranged upside down, forming a hollow tube shape, the injection hole 622 is formed therein is injected into the drying sludge heated in the near infrared conveyor 500, the lower portion, The first discharge port 624 and the second discharge port 626 are formed to discharge the classified dry sludge to both sides.

And as shown on the flow path connecting the inlet 622 and the first outlet 624 is provided with a classification plate 640, the classification plate 640 is a mesh formed to filter in a sieve method It can be or sieve.

When the size of the mesh is adjusted, dry sludge having particles of a predetermined size or less is discharged to the first outlet 624 and recovered to the mixer 100, and the second having the relatively large particles is the second outlet 626. To be discharged. This is the result of analyzing the particle size of the dry sludge finally passed through the cyclone separator 400 has a variety of sizes up to 0.1 ~ 4mm, the moisture content measured by the particle size is different and the smaller the particle size was lower the moisture content.

Therefore, since the dry sludge having a smaller size has a low water content and a relatively large amount of dry solids, the dry sludge is classified and recovered to the first outlet 624 and sent to the mixer 100. Thus, when the drying sludge and the raw sludge are mixed in the mixer 100, the water content of the mixed sludge can be lowered and the amount of the dry solid can be increased on an average by a relatively small amount of the dried sludge.

For reference, it may be desirable to install the air nozzle 660 to remove the sludge periodically deposited on the classification plate 640 to eliminate the accumulation of sludge.

In the present invention, a drying sludge storage tank 700 may be separately provided at one side of the mixer 100. The dry sludge storage tank 700 is provided with an inlet through which the dry sludge discharged and recovered from the classifier 600 may be re-injected, and the supply screw 760 may transfer a fixed amount to the lower portion. Is installed and the load cell 720 is installed on the lower surface to detect the amount of dry sludge and receive the detected value from the pre-programmed PLC 740 to calculate the mixing ratio electronically to put the quantitative quantity into the mixer 100. Controlled.

Hereinafter, a sludge drying method using the above-described sludge drying apparatus according to another embodiment of the present invention will be described.

First, the first step is to generate the mixed sludge in the mixer 100.

The dry sludge discharged in a predetermined amount from the drying sludge storage tank 700 is introduced into the drying sludge inlet 124 and the raw sludge is introduced into the original sludge inlet 122.

In the present invention, when the water content of the raw sludge is 80%, the dry solids (DS) is about 20% and the dry solids (DS) weight of the dry sludge is about 40 to 50% and mixed together, dry sludge dry solids The amount of (DS) is mixed on average more than the amount of dry solids (DS) of the raw sludge. Here, the mixed sludge is relatively low water content (less than 75%) and the weight of the dry solid (DS) is about 25% of the total amount.

Dry sludge is mixed on the particles in the cake-shaped dewatered one sludge, so that voids are generated in the sludge, and a mixed sludge having a low water content of 75% or less than the conventional one meets the dry air supplied from the air feeder 200. Since it is easily crushed and the water enters the cyclone dryer 300 in a good separability state, the drying efficiency is improved.

The second step is a step in which the mixed sludge mixed in the first step is introduced while the moving speed is increased by the air blower 200 and injected into the cyclone dryer 300.

In the third step, the mixed sludge and the air introduced into the cyclone dryer 300 are rotated in a spiral while forming a descending turbulent flow, dried, and then passed through the cyclone dryer 300 provided in multiple stages to raise the cyclone separator 400. ) Is entering the step.

In the fourth step, the dry sludge separated from the wet air in the cyclone separator 400 is introduced into the near-infrared conveyor 500. The dampers separated from the cyclone separator 400 are discharged to the washing tower 800 and the dry sludge having a relatively large amount of dried solids collects in the lower portion of the cyclone separator 400. At this time, the water content is about 60%.

In the fifth step, the dried sludge introduced into the near-infrared ray conveyor 500 is heated by the near-infrared rays, further reduced in moisture content, re-dried, and injected into the classifier 600.

The near infrared conveyor 500 further lowers the moisture content of about 3%.

In the sixth step, the dry sludge injected into the classifier 600 is separated and recovered separately from the dry sludge having relatively small particles, and is resupplyed to the mixer 100 of the first step. The remainder can be packed and discharged into dry sludge that has completed drying.

In the present invention, the drying efficiency is improved while these steps are repeated, and the effect of energy saving is great. As a result of the experiment, the moisture content of the dry sludge discharged by the present invention compared to the water content of 80% of the first sludge to be obtained was 50% or less, and the sludge weight reduction rate was 60% to the initial weight.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art, various modifications of the present invention within the scope of the claims without departing from the spirit and scope of the present invention And can be changed.

100: mixer 120: mixing tank
122: one sludge inlet 124: dry sludge inlet
126: mixed sludge outlet 140: mixed screw
142: impeller 144: stirring spatula
160: transfer screw 162: punched plate
162a: drilling hole 164: rotary cutter
200: air blower 220: blower
240: flow rate amplifier
300: cyclone dryer 400: cyclone separator
500: near infrared conveyor 510: conveyor body
512: inlet 514: outlet
520: screw conveyor 530: near infrared lamp
540: reflector 550: exhaust duct
600: classifier 620: classification body
622: inlet 624: first outlet
626: second outlet 640: classification plate
660: air nozzle
700: dry sludge storage tank 720: load cell
740: PLC 760: supply screw
800: washing tower 900, 900 ': controller

Claims (8)

delete Drying sludge inlet 124 and the first sludge inlet 122 is formed in the upper and the mixed sludge discharge port 126 is formed in the lower, and a pair is provided inside the mixing tank 120 while rotating Mixing screw 140 for mixing the dry sludge and the original sludge, and transfer screw 160 for discharging to the mixing sludge outlet 126 by transporting the mixed sludge disposed on the lower side of the mixing screw 140 to one side Mixer 100 consisting of;
An air feeder 200 injecting mixed sludge discharged from the mixer 100 and supplying air to the introduced mixed sludge to inject mixed sludge;
The sludge is connected to the air supply 200 and comprises a conical chamber, a reverse conical throttle inlet provided on the bottom of the chamber, and an inner diameter pipe located in the center of the chamber is made of mixed sludge injected into the interior A cyclone dryer (300) for swirling air and drying the mixed sludge;
A cyclone separator 400 connected to the cyclone dryer 300 and configured to have a conical shape, and the air introduced into the cyclone separator is discharged to an upper side and separated into a dry sludge bottom;
A near-infrared conveyor (500) connected to the lower portion of the cyclone separator (400) for heating and re-drying with near-infrared rays while transferring the introduced sludge;
A classifier 600 for classifying the dry sludge flowing out from the near-infrared conveyor 500 into two types according to the size of the particles and discharging them respectively;
Sludge drying apparatus, characterized in that for recovering the dry sludge having a relatively small particles in the dry sludge discharged to the classifier 600 and re-supply to the mixer (100). The method of claim 2,
Sludge drying device, characterized in that a plurality of stirring spatula 144 is radially coupled to the impeller 142 of the mixing screw 140. The method of claim 2,
One side of the transfer screw 160 is provided with a disk-shaped perforated plate 162 formed with a plurality of perforated holes 162a to be discharged into a plurality of strands through the perforated holes 162a, One side of the perforated plate 162 is provided with a rotary cutter 164, the sludge drying apparatus, characterized in that for discharging the discharged mixed sludge at a predetermined interval. The method of claim 2,
The near infrared conveyor 500,
Conveyor body 510 is provided with an inlet 512 for inflow of the dry sludge separated from the cyclone separator 400 and an outlet 514 for outflow, and conveys the dry sludge built into the conveyor body 510. The near-infrared lamp 530 for irradiating near-infrared rays to the screw conveyor 520, the dry sludge disposed on the upper side of the screw conveyor 520, and installed above the near-infrared lamp 530 to reflect near-infrared rays. Sludge drying apparatus, characterized in that consisting of a reflecting plate 540 and an exhaust duct 550 coupled to the conveyor body 510 to discharge water vapor generated from the dry sludge to the outside. The method of claim 2,
The classifier 600,
An injection hole 622 into which the dry sludge heated in the near-infrared conveyor 500 is injected, and a classification body 620 in which a first discharge port 624 and a second discharge port 626 are formed so that the injected dry sludge is discharged. Sludge drying apparatus, characterized in that consisting of a classification plate 640 is provided on the flow path connecting the injection port 622 and the first discharge port 624, but passing only the dry sludge having a relatively small particle size. The method according to any one of claims 2 to 6,
On one side of the mixer 100,
Sludge drying, characterized in that the sludge drying tank 700 is further provided to recover and store a portion of the dry sludge discharged through the classifier 600 and controlled to inject a fixed amount into the mixer 100. Device. delete

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