JP6100084B2 - Evaporative concentration apparatus and cleaning method thereof - Google Patents

Description

  The present invention relates to an evaporation concentration apparatus for evaporating and concentrating a liquid and a cleaning method thereof, and more particularly to an evaporation concentration apparatus suitable for concentrating a liquid for food and a cleaning method thereof.

As an evaporative concentration apparatus for evaporating and concentrating a liquid, for example, in Patent Document 1, a plurality of heat transfer tubes are provided in an upper part of a hermetic evaporator in which a liquid to be treated such as a waste liquid to be concentrated is stored in a lower part. The liquid to be treated supplied by a circulation pump is sprayed on the outer surface of each heat transfer tube by a spray nozzle, and the generated steam is heated by compressing it with a steam ejector. An evaporative concentration apparatus is disclosed in which the liquid to be treated sprayed on the outer surface of each heat transfer tube is heated and evaporated by supplying the heat transfer tube through the duct.

Japanese Patent Laid-Open No. 7-24202

  When the liquid to be processed to be concentrated by the evaporative concentration apparatus is a waste liquid, the waste liquid may contain various metal components, and gradually scales on the outer surface of the heat transfer tube as time passes. As a result, the heat transfer efficiency decreases.

  For this reason, conventionally, the apparatus is periodically opened manually and the high-pressure cleaning liquid from the jet nozzle is sprayed onto the outer surface of the heat transfer tube inside the apparatus for cleaning.

  If the liquid to be treated is not a waste liquid but a liquid for food such as tea, coffee, soup extract, etc. It is necessary to wash frequently in order to prevent deterioration or deterioration of taste due to. Furthermore, it is preferable that not only the outer surface of the heat transfer tube for heating the liquid to be treated but also the inside thereof can be cleaned.

  However, as described above, in the conventional evaporative concentration apparatus in which the apparatus is periodically opened manually and the high pressure cleaning liquid is sprayed for cleaning, it is difficult to perform such frequent cleaning or cleaning of the inside of the heat transfer tube.

  The present invention has been made in view of the above points, and it is an object of the present invention to allow the inside of a heat transfer tube to be cleaned, and to easily clean each part.

  In order to achieve the above object, the present invention is configured as follows.

(1) An evaporation concentrating apparatus of the present invention is an evaporation concentrating apparatus including an evaporator that evaporates a liquid to be processed in a reduced pressure state equal to or lower than an atmospheric pressure, and includes a plurality of heating liquids in the evaporator. Circulating means in which a heat transfer tube is disposed and the liquid to be treated stored in the bottom of the evaporator is returned to the top of the evaporator and supplied to the outer surface of the heat transfer tube, and the heat transfer to which steam is supplied A condensed water pump that discharges condensed water generated in the pipe, a cleaning liquid supply pipe that supplies cleaning liquid into the heat transfer pipe, and a discharge path on the discharge side of the condensed water pump are branched and connected to the heat transfer pipe. A branch path, and when the condensed water is discharged from the condensed water pump, the discharged condensed water is discharged through the discharge path, and when the cleaning liquid is discharged from the condensed water pump, The cleaning liquid to be discharged is By introducing into the heat transfer tube through, the washing solution, in which is circulated between the heat transfer tube and the condensed water pump.

  According to the evaporative concentration apparatus of the present invention, the discharge path on the discharge side of the condensed water pump that discharges the condensed water generated in the plurality of heat transfer tubes is branched, and the water from the condensed water pump is introduced into the heat transfer tubes. Therefore, the water from the heat transfer tube can be returned to the heat transfer tube again through the branch route by the condensed water pump. Accordingly, the cleaning liquid can be circulated between the heat transfer tube and the condensing pump to clean the inside of the heat transfer tube.

  (2) In a preferred embodiment of the evaporation concentrator of the present invention, an injector for injecting a cleaning liquid onto the inner surface of the evaporator and the outer surface of the heat transfer tube is provided in the evaporator.

  According to this embodiment, since the injector is provided in the evaporator, the cleaning liquid can be easily sprayed from the injector to the inner surface of the evaporator and the outer surface of the heat transfer tube.

(3) evaporation equipment of the present invention is an evaporative concentration apparatus comprising an evaporator for evaporating the liquid to be treated in the following reduced pressure atmosphere, inside the evaporator, a plurality of heating the liquid to be treated The heat transfer tube is disposed, circulating means for returning the liquid to be treated stored at the bottom of the evaporator to the top of the evaporator and supplying it to the outer surface of the heat transfer tube, and the heat transfer supplied to the steam. A discharge path on the discharge side of the condensed water pump, comprising: a condensed water pump that discharges condensed water generated in the heat pipe; and a compressor that compresses steam generated in the evaporator and supplies the compressed steam to the heat transfer pipe. And a branch path for introducing water discharged from the condensate pump into the heat transfer pipe is provided, and cleaning liquid is injected into the pipe from the evaporator to the compressor. In the middle of the pipe line from the compressor to the heat transfer pipe Off valve is provided.

According to the present invention , the on-off valve in the middle of the pipe line from the compressor to the heat transfer pipe is closed, and the cleaning liquid is injected from the injector in the pipe line from the evaporator to the compressor, so that the evaporator changes from the evaporator to the on-off valve. The entire pipeline and the compressor can be cleaned.

  (4) In still another embodiment of the evaporative concentration apparatus of the present invention, the liquid to be treated is a liquid for food.

  According to this embodiment, the inside of the heat transfer tube can be washed, and the inside of the evaporator and the pipe line can be easily washed by the injector. Therefore, for foods that require frequent washing in order to keep it hygienic all the time. Suitable for liquid concentration.

(5) cleaning method of evaporation apparatus of the present invention is a cleaning method of evaporation apparatus according to the present invention, the discharge side of the condensed water pump, switching from the discharge route to the branch path, the washing liquid Is circulated between the condensate pump and the heat transfer tube.

  According to the cleaning method of the evaporative concentration apparatus of the present invention, the inside of the heat transfer tube can be cleaned with the cleaning liquid.

  According to the present invention, the inside of the heat transfer tube can be cleaned by circulating the cleaning liquid between the heat transfer tube and the condensation pump.

FIG. 1 is a configuration diagram of an evaporative concentration apparatus according to an embodiment of the present invention. FIG. 2 is a configuration diagram of an evaporative concentration apparatus according to another embodiment of the present invention.

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

  FIG. 1 is a configuration diagram of an evaporative concentration apparatus according to an embodiment of the present invention.

  The evaporative concentration apparatus of this embodiment is a device for evaporating and concentrating a liquid for food such as tea, coffee, fruit juice, milk, jam or soup as a liquid to be treated, and includes a sealed evaporator 1. .

  The evaporator 1 has a vertically long rectangular parallelepiped shape as a whole, and the bottom portion has a quadrangular pyramid shape.

  The bottom portion of the square pyramid of the evaporator 1 is a liquid reservoir 18 for storing the liquid to be treated. A pair of left and right headers 2 and 3 are provided on the top, and both the headers 2 and 3 are provided. A plurality of heat transfer tubes 4 connecting them are provided in the horizontal direction. In addition, a partition plate 2c that partitions the inlet chamber 2a and the folding chamber 2b is provided in the header 2 on one inlet side of the headers 2 and 3, and in the header 3 on the other outlet side, A partition plate 3c that partitions the folding chamber 3a and the outlet chamber 3b is provided.

  A discharge pipe 27 serving as a discharge path for discharging the condensate accumulated by flowing down the heat transfer pipe 4 is connected to the lower part of the folding chamber 3 a of the header 3 on the outlet side. A condensate pump 11 is provided. A discharge opening 27 between the return chamber 3a of the header 3 on the outlet side and the condensed water pump 27 is provided with a first on-off valve 28 that is opened during a concentration process other than the cleaning described later. The discharge pipe 27 on the discharge side of the condensed water pump 11 is provided with a third on-off valve 37 that is opened when condensed water is drained.

  A vacuum pump 10 for reducing the inside of the evaporator 1 to atmospheric pressure or less is connected to the outlet chamber 3b above the header 3 on the outlet side.

  The liquid to be treated in the liquid reservoir 18 is supplied to the spray nozzle 7 provided in the upper part of the evaporator 1 by the circulation pump 5 through the circulation pipe 6, and the outer surface of each heat transfer tube 4 from the spray nozzle 7. Then, the liquid is circulated to the liquid reservoir 18 in the evaporator 1 after being sprayed. In the middle of the circulation line 6, a discharge line 8 for discharging the concentrated liquid to be processed is connected. The evaporator 1 is connected to a stock solution supply line 23 for supplying a liquid to be treated as a stock solution.

  Circulation by which the liquid to be treated stored in the liquid reservoir 18 is circulated by the circulation pump 5, the circulation pipe 6 and the spray nozzle 7 so as to be supplied from the spray nozzle 7 above the evaporator 1 to the outer surface of the heat transfer pipe 4. Means are configured.

  The upper part of the evaporator 1 is connected to a compressor 9 such as a blower via a steam line 19, and the steam from the evaporator 1 is compressed by the compressor 9 and is input to the inlet side via a steam line 20. To the header 2. The steam line 20 is provided with a gate valve 26 as an on-off valve that is opened except during the later-described cleaning. In addition, it may replace with the compressor 9 and may compress with a steam ejector.

  The evaporative concentration apparatus of this embodiment concentrates a liquid for food as described above, and has a sanitary specification. That is, in this embodiment, the evaporator 1 is made of stainless steel, and in order to enhance the cleaning effect, the corners of the inner surface of the evaporator 1 are rounded and curved, and further, Buffing is applied. The main pipeline is composed of sanitary piping made of stainless steel.

  Next, the concentration process of the liquid to be processed by the above evaporative concentration apparatus excluding the configuration for cleaning described later will be described.

  In the concentration process of the liquid to be processed, the inside of the evaporator 1 is decompressed by the vacuum pump 10 and the liquid to be processed is supplied from the stock solution supply line 23 to the liquid reservoir 18 in the evaporator 1. Further, high-pressure steam is supplied to the header 2 on the inlet side as driving steam through the steam supply line 25, and the circulating pump 5 is driven so that the liquid to be processed in the liquid reservoir 18 is fed into the evaporator 1. Is supplied to the spray nozzle 7 at the top of the heat transfer tube 4 and sprayed on the outer surface of each heat transfer tube 4.

  The sprayed liquid to be treated flows down to the lower liquid reservoir 18 in the evaporator 1, and is heated and evaporated on the outer surface of each heat transfer tube 4. The generated steam is sent from the steam line 19 to the compressor. In order to heat the liquid to be treated which is sucked and compressed into 9 and then introduced into each heat transfer tube 4 in the evaporator 1 through the header 2 on the inlet side and sprayed on the outer surface of each heat transfer tube 4. Used as a heat source. Condensate produced in each heat transfer tube 4 and accumulated in the lower portion of the folding chamber 3a of the header 3 on the outlet side is discharged out of the system by the condensed water pump 11 through the discharge pipe 27. The liquid reservoir 18 is supplied with a reduced amount of stock solution by evaporation and concentration.

  In this embodiment, a liquid for food, for example, a liquid to be treated such as tea or coffee is concentrated, so that each part can be easily washed as follows.

  First, in order to be able to clean the inside of the plurality of heat transfer tubes 4, the discharge side discharge pipe 27 of the condensed water pump 11 is branched and connected to the outlet chamber 3b of the header 3 on the outlet side. A branch pipe 29 is provided so that water from the condensed water pump 11 can be introduced into the upper heat transfer pipe 4 connected to the outlet chamber 3b. The branch pipe 29 is provided with a fourth on-off valve 36 that is closed during the concentration process and opened during cleaning of the heat transfer pipe 4.

  In addition, a bypass line 30 is provided to connect the suction side discharge line 27 of the condensed water pump 11 and the inlet chamber 2a of the header 2 on the inlet side, and this bypass line 30 is closed during the concentration process, A second on-off valve 31 is provided that is opened when the inside of the heat transfer tube 4 is cleaned.

  When cleaning the inside of the heat transfer pipe 4, the first on-off valve 28 opened at the time of the concentration process is closed, while the second on-off valve 31 of the bypass pipe line 30 is opened. Further, the fourth on-off valve 36 of the branch pipe 29 on the discharge side of the condensed water pump 11 is opened. At this time, the third on-off valve 37 of the discharge pipe 27 on the discharge side of the condensed water pump 11 is closed.

  Furthermore, the gate valve 26 provided in the steam line 20 for supplying steam from the compressor 9 to the header 2 on the inlet side is closed.

  Thereby, at the time of cleaning the inside of the heat transfer pipe 4, the discharge side of the condensed water pump 11 reaches the outlet chamber 3 b of the header 3 on the outlet side via the branch pipe 29, and the upper direction is opposite to the steam supply direction. A circulation path is formed from the heat transfer tube 4 to the lower heat transfer tube 4 and returning to the suction side of the condensed water pump 11 through the inlet chamber 2a of the header 2 on the inlet side.

  When cleaning the inside of the heat transfer tube 4, first, the inside of the circulation path is filled with a cleaning liquid. In this embodiment, for example, a level switch is provided in the outlet chamber 3b of the header 3b on the outlet side as detection means for detecting the supply amount of the cleaning liquid supplied into the circulation path. Until this level switch detects that the circulation path including the heat transfer pipe 4 is substantially full and reaches a predetermined liquid level, the cleaning liquid supply pipe (not shown) is connected to the inlet chamber 2a of the header 2 on the inlet side. Supply the cleaning liquid.

  After filling the circulation path with the cleaning liquid in this way, the condensate pump 11 is driven, and the cleaning liquid is circulated through the circulation path including the heat transfer tubes 4, thereby the inside of the headers 2 and 3 and the heat transfer tubes 4. Clean inside.

  The bypass pipe 30 that connects the inlet chamber 2a of the header 2 on the inlet side and the suction side of the condensate pump 11 to provide a circulation path for cleaning is the folding chamber of the header 3 on the outlet side. When a circulation path for cleaning is configured using the discharge pipe 27 that connects 3a and the suction side of the condensed water pump 11, the cleaning liquid is placed in the lower heat transfer pipe 4 that connects the folding chamber 3a and the inlet chamber 2a. It is because it cannot supply.

  For cleaning the inside of the heat transfer tube 4 as described above, the above-described on-off valves 26, 28, 31, 36, etc. may be constituted by automatic valves and automatically controlled by a control device (not shown) as follows. .

  That is, after the concentration process is completed, when the heat transfer pipe 4 is cleaned, the control device closes the first on-off valve 28 on the suction side of the condensed water pump 11 and opens the second on-off valve 31 of the bypass pipe 30. To do. Further, the control device opens the fourth on-off valve 36 of the branch pipe 29 on the discharge side of the condensed water pump 11, and further supplies the steam from the compressor 9 to the header 2 on the inlet side. The gate valve 26 is closed.

  Next, an opening / closing valve of a cleaning liquid supply pipe (not shown) is opened to the inlet chamber 2a of the header 2 on the inlet side to start supplying the cleaning liquid. By the above-described level switch, the circulation path including the heat transfer pipe 4 is substantially full. The cleaning solution is supplied until it is detected that this has occurred. Thereafter, the control device starts driving the condensed water pump 11 and cleans the inside of both headers 2 and 3 and the inside of the heat transfer tube 4 over a certain period.

  In this embodiment, in order to be able to clean the inside of the evaporator 1, the inside of the evaporator 1 includes a plurality of first surfaces for cleaning each inner surface including tube plates and the like that support both ends of each heat transfer tube 4. A cleaning nozzle 32 is provided, and a plurality of second cleaning nozzles 33 for cleaning the outer surface of each heat transfer tube 4 are provided. The second cleaning nozzle 33 for cleaning the outer surface of the heat transfer tube 4 is not limited to the position above the heat transfer tube 4, and is provided at a side position of the heat transfer tube 4 so that the cleaning liquid can be injected between the upper and lower heat transfer tubes 4. May be.

  At the time of cleaning, the cleaning liquid is supplied from the cleaning pump 35 to the cleaning nozzles 32 and 33 as the injectors via the first cleaning liquid supply pipe 34, and the cleaning liquid is sprayed to the respective parts in the evaporator 1 for cleaning.

  The cleaning liquid can be supplied to the evaporator 1 through a cleaning liquid supply pipe 45 branched from the suction side of the cleaning pump 35. At the time of cleaning, the cleaning liquid is supplied to the liquid reservoir 18 of the evaporator 1 instead of the liquid to be treated, and this cleaning liquid is sprayed from the spray nozzle 7 above the evaporator 1 onto the outer surface of the heat transfer tube 4 by the circulation pump 5. The outer surface of the heat transfer tube 4 can be cleaned.

  Further, in this embodiment, a plurality of third cleaning nozzles 36 for injecting a cleaning liquid into the steam pipe 19 are arranged at appropriate intervals in the steam pipe 19 connecting the upper part of the evaporator 1 and the compressor 9. Is provided. The steam pipe 20 between the compressor 9 and the inlet chamber 2a of the header 2 on the inlet side is provided with the gate valve 26 as described above, and the gate valve 26 is closed during cleaning.

  In this state, the cleaning liquid is supplied from the cleaning pump 35 to the third cleaning nozzles 36 as the injectors via the second cleaning liquid supply pipes 40, and the cleaning liquid is supplied from the third cleaning nozzles 36 into the steam pipes 19. Is sprayed and washed. At this time, the cleaning liquid in the steam line 19 is filled in the steam line 20 up to the gate valve 26, and the cleaning liquid is accumulated in the compressor 9 and cleaned.

  The number, the spray angle, or the arrangement of each of the cleaning nozzles 32, 33, and 36 can be selected as appropriate so that each part can be cleaned effectively.

  The cleaning liquid may be a cleaning liquid containing a cleaning agent or a bactericidal agent, or may be clean water for rinsing.

  As described above, in the evaporative concentration apparatus of this embodiment, at the time of cleaning, the cleaning liquid can be circulated in the circulation path between the heat transfer tube 4 and the condensed water pump 11 to clean the inside of the heat transfer tube 4, Cleaning can be performed by spraying the cleaning liquid from the first and second cleaning nozzles 32, 33 onto the inner surface of the evaporator 1 and the outer surface of the heat transfer tube 4, and further, the steam tube from the upper portion of the evaporator 1 to the gate valve 26. The cleaning liquid can be sprayed from the third cleaning nozzle 36 into the passages 19 and 20 to clean the inside of the steam pipes 19 and 20 and the compressor 9.

  Thus, each part of the evaporative concentration apparatus including the inside of the heat transfer tube 4 can be easily washed, which is suitable for the concentration of food liquids that are required to be kept clean for hygiene purposes.

  Evaporation and concentration of food liquids involves heating and evaporation of food liquids, so increasing the residence time in the evaporative concentration device affects the quality such as color, taste, and aroma. Is required.

  Further, in this embodiment, a positive displacement pump is used as the circulation pump 5, and this positive displacement pump has a smaller NPSH (net suction head) than a conventional vortex pump. The water level of the liquid to be treated stored in the liquid reservoir 18 can be set low, that is, the amount of liquid retained can be reduced, so that the residence time of the liquid to be treated in the evaporative concentration apparatus is shorter than that of the prior art. can do.

  Moreover, the bottom of the evaporator 1 has a cone shape in which the horizontal cross-sectional area decreases downward, and in this embodiment is a quadrangular pyramid, so that the liquid to be treated is stored in the bottom of the evaporator 1. The amount can be further reduced, and the residence time of the liquid to be treated in the evaporation concentration process can be further shortened.

  Moreover, the evaporation concentrator of this embodiment is used as a heat source for heating and evaporating the liquid to be processed by the heat transfer tube 4 by compressing and raising the temperature of the vapor generated from the liquid to be processed by the compressor 9. That is, since the heat of the steam generated from the liquid to be treated is recovered and used as a heat source, the energy efficiency is higher than that of a concentration apparatus that is not a vapor compression type.

  In the above embodiment, the cleaning liquid is supplied to each part by the cleaning pump 35 and cleaning is performed. However, as another embodiment of the present invention, the cleaning pump 35 is omitted as shown in FIG. May be supplied.

  In FIG. 2, a stock solution supply line 23a for supplying a stock solution to be treated is connected to the evaporator 1, and this stock solution supply line 23a also serves as a cleaning solution supply line for supplying a cleaning solution, or is indicated by a broken line. As shown, it merges with the cleaning liquid supply conduit.

  A circulation pipe 6a from the circulation pump 5 to the spray nozzle 7 provided in the upper part in the evaporator 1 is provided with a first cleaning liquid supply pipe for supplying a cleaning liquid to the cleaning nozzles 32 and 33 in the evaporator 1 in the middle. The passage 34a is branched into a second cleaning liquid supply pipe 40a for supplying a cleaning liquid to each cleaning nozzle 36 in the steam pipe 19 from the evaporator 1 to the compressor 9. The cleaning liquid supply pipes 34a and 40a are provided with fifth and sixth on-off valves 42 and 43 that are opened during cleaning. Other configurations are the same as those of the above-described embodiment.

  In this embodiment, when the evaporator 1 or the like is cleaned, the on-off valves 42 and 43 of the first and second cleaning liquid supply lines 34a and 40a are opened, and the cleaning liquid is supplied from the raw liquid supply line 23a that also serves as the supply of the cleaning liquid. At the same time, the circulation pump 5 is driven. Accordingly, the cleaning liquid is supplied to the spray nozzle 7 and the cleaning nozzles 32 and 33 in the evaporator 1 through the circulation line 6a and the first cleaning liquid supply line 34a, and the inside of the evaporator 1 is cleaned. Then, the gas is supplied to each cleaning nozzle 36 in the steam line 19 through the circulation line 6a and the second cleaning liquid supply line 40a, and the inside of the steam line 19 and the compressor 9 are cleaned.

  Thus, without providing the cleaning pump 35, the circulation pump 5 can supply the cleaning liquid to the nozzles 7, 32, 33, and 36 to clean each part.

  In the above-described embodiment, the present invention is applied to the concentration of a liquid for food. However, the present invention is not limited to a liquid for food. Applicable.

DESCRIPTION OF SYMBOLS 1 Evaporator 2, 3 Header 4 Heat transfer pipe 5 Circulation pump 6, 6a Circulation pipe line 7 Spray nozzle 9 Compressor 18 Liquid storage part 29 Branch pipe lines 32, 33, 36 Cleaning nozzle (injector)
35 Washing pump

Claims (5)

An evaporative concentration apparatus comprising an evaporator for evaporating a liquid to be treated in a reduced pressure state below atmospheric pressure,
In the evaporator, a plurality of heat transfer tubes for heating the liquid to be processed are arranged,
Circulation means for returning the liquid to be treated stored at the bottom of the evaporator to the top of the evaporator and supplying it to the outer surface of the heat transfer tube;
A condensed water pump for discharging condensed water generated in the heat transfer pipe to which steam is supplied ;
A cleaning liquid supply pipe for supplying a cleaning liquid into the heat transfer pipe;
A branch path for branching a discharge path on the discharge side of the condensed water pump and connecting to the heat transfer pipe,
When the condensed water is discharged from the condensed water pump, the discharged condensed water is discharged through the discharge path, and when the cleaning liquid is discharged from the condensed water pump, the discharged cleaning liquid is discharged. The cleaning liquid is circulated between the condensate pump and the heat transfer pipe by introducing it into the heat transfer pipe through the branch path .
An evaporative concentration apparatus characterized by that. In the evaporator, an injector for injecting a cleaning liquid onto the inner surface of the evaporator and the outer surface of the heat transfer tube is provided.
The evaporative concentration apparatus according to claim 1. An evaporative concentration apparatus comprising an evaporator for evaporating a liquid to be treated in a reduced pressure state below atmospheric pressure,
In the evaporator, a plurality of heat transfer tubes for heating the liquid to be processed are arranged,
Circulation means for returning the liquid to be treated stored at the bottom of the evaporator to the top of the evaporator and supplying it to the outer surface of the heat transfer tube;
A condensed water pump for discharging condensed water generated in the heat transfer pipe to which steam is supplied;
A compressor that compresses the steam generated in the evaporator and supplies the steam into the heat transfer tube,
Branching the discharge path on the discharge side of the condensed water pump, providing a branch path for introducing water discharged from the condensed water pump into the heat transfer pipe,
Wherein the evaporator conduit leading to the compressor from the injector for injecting cleaning liquid into the conduit is provided,
In the middle of the pipeline from the compressor to the heat transfer tube, an on-off valve is provided.
An evaporative concentration apparatus characterized by that . The liquid to be treated is a liquid for food.
The evaporative concentration apparatus according to any one of claims 1 to 3. A method for cleaning an evaporation concentrator according to claim 1,
Wherein the discharge side of the condensate pump, switching from the discharge route to the branch path, the cleaning liquid is circulated between the heat transfer tube and the condensed water pump,
A method for cleaning an evaporative concentration apparatus.

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