JPS61141986A - Evaporation apparatus - Google Patents

Abstract

PURPOSE:To make sludge hard to precipitate, by providing partition floors for patitioning the interior of an evaporator into up-and-down multistage evaporation chambers and providing nozzles comunicated with the evaporation chamber to the floors while providing a pump for evacuating each evaporation chamber. CONSTITUTION:Sewage, which was heated by a sewage heater 12 and subsequently supplied to the uppermost stage evaporation chamber 3a of an evaporator 1, is flowed down to each lower stage evaporation chamber 3 through the nozzles 4 provided to the floor 2 of the evaporation chamber 3a and receives flash evaporation in the lower stage evaporation chamber 3. Generated steam is guided to a water feed heating chamber 7 through a mist separator 10 and condensed by a heat transfer tube 11 to be converted to water. The sewage increased in its concn. is guided to the evaporation chamber 3 from the nozzles 4 of the floor to be subjected to flash evaporation. Sewage repeatedly increased in its concn. is discharged through a pump 17 and a valve 18. Water generated in the water feed heating chamber 7 is recovered to be used in various uses.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an evaporation device for recovering clean water from wastewater, and more specifically, industrial wastewater, particularly highly concentrated wastewater or corrosive wastewater from the food industry, etc. Of these, it relates to evaporation equipment that recovers clean water from sewage.

Conventional technology Conventionally, in evaporation equipment used in equipment for desalinating seawater using the multi-stage flood method or multiple-effect method, and equipment for concentrating pulp waste liquid using the multiple-effect method, the inside of the condensing heat transfer tube is directly connected. Seawater and highly concentrated black liquor were passed through it.

Problems to be Solved by the Invention When it comes to the above-mentioned conventional configuration, it is impossible to avoid the fact that scale and sludge deposited on the walls of the heat exchanger tubes increase the heat transfer resistance of the walls of the heat exchanger tubes. , it is necessary to increase the heat transfer area in advance, which poses a problem in that the overall size of the device increases.

The present invention solves the above-mentioned conventional problems.
In order to perform flash evaporation of wastewater such as industrial wastewater, where sludge and the like tend to adhere to the inside of heat transfer tubes, and to recover water for use from this flash steam, a medium that does not easily deposit scale and sludge is introduced into the heat transfer tubes and removed from the flash steam. By recovering heat and submerging water from the flash steam, it is possible to prevent scale, sludge, etc. from adhering to the heat transfer tubes, and to reduce the heat transfer area. The upper neck can be made smaller and even longer! An object of the present invention is to provide an evaporator that enables continuous operation.

Means for Solving the Problems In order to solve the above problems, the evaporator of the present invention is provided with a floor that partitions the interior of the evaporator into which sewage is supplied from above into a multi-tiered evaporation chamber. A feed water heater is provided in which a nozzle communicating with the adjacent evaporation chambers is provided, a pump is provided to reduce the pressure in each of the evaporation chambers, and feed water heating chambers are formed in multiple stages to which steam from each of the evaporation chambers is respectively guided. A condensing heat exchanger tube is disposed within the feed water heater, and a medium that does not easily deposit scale and sludge is introduced into the heat exchanger tube.

Due to the working structure, industrial wastewater, which is supplied to the evaporator and where scale, sludge, etc. tend to adhere to the inside of the heat transfer tubes, is passed through the nozzle into the evaporation chamber under reduced pressure, where it flash evaporates and is generated. The steam is guided to the feed water heating chamber and condensed by the heat transfer tube through which a medium that does not easily deposit scale, sludge, etc. flows, so water can be recovered from the wastewater without any scale, sludge, etc. adhering to the heat transfer tube. DeA
Ru.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. Figure 1 is an overall configuration diagram of the evaporator, and in the drawing, 1
is an evaporator, and the inside of the evaporator 1 is divided into upper and lower multi-tiered evaporation chambers 3 by a bed 2, and each bed 2 has a nozzle 4 that passes through each of the adjacent evaporation chambers 3. is installed.

5 is a feed water heater, and the inside of the feed water heater 5 is connected to each floor 2.
The upper and lower multistage feed water heating chambers 7 are partitioned by each floor 6 on the same plane, and the uppermost feed water heating chamber 7a and the uppermost evaporation chamber 3a are adjacent to each other with a partition wall 8 in between. There is.

Reference numeral 9 denotes a partition wall having a mist separator 10 attached thereto to allow steam to pass through, and the partition wall 9 is a partition wall interposed between each of the feed water heating chambers 7 at the lower stage than the first stage and each evaporation chamber 3 adjacent thereto. equipped.

11 is a condensing heat exchanger tube, and this heat exchanger tube 11 is connected to the feed water heater 5.
The medium is arranged vertically through each floor 6 of the feed water heater 5, and the medium supplied from below the feed water heater 5 flows upward in the heat transfer tube 11. As the medium, for example, pure water, which does not easily precipitate scale or sludge, is used.

Reference numeral 12 denotes a waste water heater, which is used to preheat the waste water to be supplied to the evaporator 1 using the thermal energy of pure water led from the upper part of the feed water heater 5. The water is led to the lower part of the feed water heater 5. As the waste water heater 12, a heat exchanger that can be easily heated is used, such as a plate heat exchanger or a tubular heat exchanger equipped with a cleaning device using sponge balls. 13 is a pump for circulating pure water.

14 is a pump connected to the lower part of the uppermost water supply heating chamber 7a, and is a pump that is supplied with i! from a boiler or the like. ! The steam of i is up to 2
Pure water flowing through the heat exchanger tubes 11 is heated in the L-stage feed water heating chamber 7a, and the condensed water is returned to a steam supply source such as a boiler by the pump 14.

Reference numeral 15 denotes a conduit that connects the feed water heating chambers 7 adjacent to each other in the lower tier than the first tier. They are connected to each other at the top.

A valve 16 has one end connected to each water supply heating chamber 7 and a narrow end connected to a vacuum bong, and the pressure in each water supply heating chamber 7 is lowered by the valve 16 as it is lower.

Next, the effect on the steam configuration will be explained.

The wastewater heated by the wastewater heater 12 and supplied to the tenth stage evaporation chamber 3a of the first condenser generator 1 flows down to the lower stage evaporation chamber 3 through the nozzle 4 provided on the floor 2 of the evaporation chamber 3a. , flash evaporation is performed in the lower evaporation chamber 3. The generated steam is guided to the adjacent feed water heating chamber 7 via the mist separator 10, and is condensed into water by the heat transfer tube 11 in the feed water heating chamber 7. The concentration of sewage has increased by the amount of water that has evaporated,
The vapor is led from the nozzle 4 on the floor 2 to the evaporation chamber 3 on the lower stage side and undergoes flash evaporation again, and the generated vapor is passed through the mist separator 10.
Adjacent water supply heating through? 7 and is condensed into water by the heat transfer tube 11. Sewage whose concentration has increased due to repeated flash evaporation is discharged as concentrated wastewater via pump 17 and valve 18. If water recovery is not sufficient, valve 1
) is again led to the evaporator 1. Each water supply heating chamber 7
The water generated is transferred to the lower water supply heating chamber 7 through the pipe 15, and is recovered from the lowermost water supply heating chamber 7 via the pump 20 and used for various purposes.

The pure water flowing in one direction inside the heat exchanger tube 11 is self-heated by the condensed water flowing down the outer surface of the wire tube 11, and after being sequentially inspected, it is supplied from an external heat source such as a boiler to the uppermost feedwater heating chamber 7a. The purified water heated by high temperature steam is sewage heater 1? heat the wastewater.

In this way, in the steam embodiment, the pure water flowing through the heat exchanger tube 11 is heated by the heat generated when flash evaporation condenses and the high-temperature steam supplied from an external heat source such as a boiler, and the purified water becomes heated. Since wastewater is heated by the wastewater heater 12, wastewater with a high concentration of α can be supplied to the evaporator 1, so that the wastewater can be flash-evaporated efficiently.

FIG. 2 shows an embodiment of the present invention, in which 21 is an evaporator and the interior of the evaporator 21 is a floor 2? There are two evaporation chambers 23, upper and lower.
The evaporation chambers 23a, 23h, and 23c are partitioned into evaporation chambers 23a, 23h, and 23c, and the pressure in the lower evaporation chambers 23a, 23b, and 23c is reduced. Each bed 22 is equipped with a nozzle 24 that communicates with the evaporation chambers 23a, 23b, 23 (2) of the upper and lower adjacent η filters.

25 is a feed water heater, and the inside of the feed water heater 25 is a floor 26.
The feed water heating chamber 27a and 27b are divided into two upper and lower stages, and the upper stage water supply heating chamber 27a and the lowest stage evaporation chamber 23a are in close contact with each other via a partition wall 28.

Reference numeral 29 denotes a partition wall to which a mist separator 30 is attached to allow steam to pass through the soil, and the partition wall 29 is interposed between the lower-stage feed water heating chamber 27b and the middle-stage evaporation chamber 23h.

31 is a condensing heat exchanger tube, and this heat exchanger tube 31 is connected to the feed water heater 2.
The pure water supplied from below the feed water heater 25 flows upward in the heat transfer tube 31 .

32 is a sewage heater, which uses the heat T energy of pure water led from the -1 part of the feed water heater 25 to evaporate IP.
: This is for preheating the waste water to be supplied to the i21, and the pure water that has been heated from the waste water is led to the lower part of the feed water heater 25. As the wastewater heater 32, a heat exchanger that is easy to clean is used, such as a plate heat exchanger or a tubular heat exchanger equipped with a cleaning device using sponge balls. 33 is a pump for circulating pure water.

34 is middle r-1? The intermediate chamber 34 and the lowest evaporation chamber 2
3c is completed by a wall 36 fitted with a mist separator 35 allowing the passage of steam.

37 is a steam ejector, and the steam led from the intermediate chamber 34 to the steam ejector 37 is heated and pressurized by high-temperature steam supplied from an external heat source such as a boiler, and then heated with the high-temperature steam to feed water on the upper stage side. It is supplied to the chamber 27a.

38 is a pipe, one end of which is connected to the lower part of the upper feed water heating chamber 27a, and the other end to the lower feed water heating chamber 27b.
Some are connected to each other.

Next, the operation of the above configuration will be explained.

The wastewater heated by the wastewater heater 32 and supplied to the uppermost evaporation chamber 23a of the post-evaporator 21 passes through the nozzle 24 provided on the floor 22 of the evaporation chamber 23a to the middle evaporation chamber 23.
b, and undergoes flash evaporation in the middle evaporation chamber 23b. The generated steam is guided to the adjacent feed water heating chamber 27b via the mis-separator 30, and is condensed into water by the heat transfer tube 31 in the feed water heating chamber 27h. The sewage whose concentration has increased by the amount of water that has evaporated is led from the nozzle 24 on the floor 22 to the evaporation chamber 23c on the lower stage side, where it flash-evaporates again. The generated steam passes through the mist separator 35 and the intermediate chamber 34 and enters the suction section of the steam JI tanker 37.
In the ejector 37, the steam IF is condensed by high-temperature steam discharged from a boiler, etc., and the pressure is raised.The high-temperature steam is led to the upper stage side feed water heating chamber 27a and condensed, and is transferred by the heat of the condensation of the child. The pure water flowing inside the heat tube 31 is heated. The water generated in the feed water heating chamber 27a is led to the lower feed water heating chamber 27b via a pipe line 38, and is recovered together with the water generated in the feed water heating chamber 27b via a pump 41 and supplied for various uses. be done.

The water in the middle and lower evaporation chambers 23b and 23c is flash-evaporated and the sewage has an increased concentration, which is pumped to a pump 38,
It is discharged as condensed waste water through the valve 39, and when the moisture recovery is not sufficient, it is returned to the evaporator 21 through the valve 40.
It will be destroyed.

The pure water flowing upward inside the heat transfer tube 31 is countercurrently heated by the condensed water flowing down the outer surface of the wire tube 31 and gradually warmed to the stomach temperature.
”] 0 stage feed water heating? The pure water heated in 27a and raised in temperature heats wastewater in the wastewater heater 32.

In this way, in the heat exchanger tube 11, the pure water flowing through the heat exchanger tubes 11 is depleted by the heat generated when the flashco steam condenses, the high-temperature steam supplied from an external heat source such as a boiler, and the high-temperature furnace air. The heated purified water is heated using gastrically pressurized flashco steam and garlic, and the wastewater is heated in the wastewater heater 32, so that high-temperature wastewater can be supplied to the evaporator 21, resulting in efficient flash evaporation of the wastewater. can be done.

In addition, although the flash steam was compressed using the steam J Zector-37 in the above-mentioned Example T, a mechanical steam compressor such as a steam compressor can also be used.

Effects of the Invention As explained above, according to the present invention, wastewater is evaporated in the evaporation chamber for 7 hours, and the generated steam is condensed by the heat exchanger tube through which a medium that does not easily cause scale and sludge precipitation flows. Therefore, it is possible to prevent an increase in the heat transfer resistance of the tube wall due to the adhesion of precipitated scale and sludge on the wall surface of the heat transfer tube, thereby making it possible to downsize the device and enable long-term continuous operation. Further, since a double grooved tube with good heat transfer characteristics can be used as the heat transfer tube disposed in the feed water heater, the KN can also be made smaller.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, and FIG. 2 is an overall configuration diagram of another embodiment. 1... Evaporator, 2... Floor, 3... Evaporation chamber, 4...
・Nozzle, 5... Feed water heater, 7... Feed water heating chamber,
11... Heat exchanger tube agent Yoshihiro Morimoto procedural amendment (voluntary) 1. Incident display ゛′-Showa 59
Patent Application No. 264725 2, Name of the invention Evaporation device 3, Relationship with the case of the person making the amendment Name of patent applicant (511) Name of Hitachi Zosen Corporation (6808) Patent attorney Yoshihiro Morimoto 5,
date (shipment date) Showa year, month, day 6, number of inventions increased by the amendment 7, part of the drawings in the full text of the specification subject to the amendment 8, contents of the amendment - The entire text of the specification is corrected as shown in the attached sheet. Of the part number "38" in the second drawing of 0, the lower "38" is replaced with "42".
I am corrected. Description 1, Name of the invention Evaporation device 2, Claim 1, A partition wall is provided to partition the inside of the evaporator into which heated wastewater is supplied into multi-stage evaporation chambers, and the adjacent evaporation chambers are connected to the wall. A feed water heater is provided in which a pump is provided to reduce the pressure in each of the evaporation chambers, and a feed water heating chamber is formed in multiple stages to which steam from each of the evaporation chambers is guided, and the feed water heater is provided with a nozzle communicating with the evaporation chamber. An evaporator characterized in that a heat transfer tube for condensation is provided, a medium that is difficult to deposit scale and sludge is introduced into the heat transfer tube, and waste water is heated by the medium. 3. Detailed Description of the Invention 111 Industrial Application Field The present invention relates to an evaporation device for recovering clean water from wastewater, and more particularly, it relates to an evaporation device for recovering clean water from wastewater, and more particularly, to industrial wastewater, particularly highly concentrated wastewater or corrosive wastewater from the food industry. This relates to an evaporation device that recovers clean water from sewage. Conventional technology Conventionally, there have been devices for desalinating seawater using the multi-stage fludge method or the multiple-effect method, and pulp vF desalination using the multiple-effect method.
In the evaporator used in devices for concentrating liquids, seawater or highly concentrated black liquor is passed directly through the condensing heat transfer tube. Problems to be Solved by the Invention According to the conventional structure described above, it is impossible to prevent scale and sludge from precipitating and adhering to the wall surface of the heat transfer tube, increasing the heat transfer resistance of the heat transfer tube wall. It was necessary to increase the thermal area, which caused the problem of increasing the size of the entire assembly. The present invention solves the conventional problems mentioned above.In order to flash-evaporate polluted water such as industrial wastewater in which scale, sludge, etc. tend to adhere to the inside of heat transfer tubes, and recover water for use from this flash steam, scale, sludge, etc. By guiding a medium in which sludge does not easily precipitate into the heat exchanger tubes, recovering heat from the flash steam, and obtaining water from the flash steam, it is possible to prevent scale, sludge, etc. from adhering to the heat exchanger tubes. Therefore, it is an object of the present invention to provide an evaporator that can miniaturize the device by making it possible to reduce the heat transfer area and further enable long-term continuous operation. Means for Solving the Problems In order to solve the above problems, the evaporator of the present invention is provided with a partition wall that divides the interior of the evaporator into which waste water is supplied into multi-stage evaporation chambers, and the partition wall is provided with a partition wall that divides the interior of the evaporator into which waste water is supplied, and the adjacent evaporator A nozzle communicating with the chamber is provided, a pump is provided to reduce the pressure in each of the evaporation chambers, a feed water heater is provided in which a multi-stage feed water heating chamber is formed into which the steam from each of the evaporation chambers is guided, and the feed water heater is provided with A heat exchanger tube for condensation is provided, a medium that does not easily deposit scale and sludge is introduced into the heat exchanger tube, and the waste water is heated by the medium. Effect With the above configuration, wastewater such as industrial wastewater that is supplied to the evaporator and where scale and sludge tend to adhere to the inside of the heat transfer tube is led from the nozzle to the evaporation chamber in a reduced pressure state and undergoes flash evaporation, resulting in the generated steam. When the water is guided into the feed water heating chamber, scale and sludge precipitate inside the tubes, and because the medium that is difficult to adhere to is condensed by the flowing heat transfer tubes, scale and sludge are deposited inside the tubes.
Water can be recovered from the wastewater without any sludge or the like attached. EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. Figure 1 is an overall configuration diagram of the evaporator. In the drawing, 1 is an evaporator, and the inside of the evaporator 1 is divided into upper and lower multistage evaporation chambers 3 by beds 2. Each bed 2 has an upper and lower RTG. A nozzle 4 is attached that communicates with each of the evaporation chambers 3 in contact with each other. 5 is a feed water heater, and the inside of the feed water heater 5 is connected to each floor 2.
A multi-tiered upper and lower water supply heating chamber 7 is formed by partitioning each floor 6 on the same plane as the uppermost one. There is. Reference numeral 9 denotes a partition wall having a mist separator 10 attached thereto to allow passage of steam, and the partition wall 9 is provided between each of the lower stage feed water heating chambers 7 below the second stage and each evaporation chamber 3 adjacent thereto. It has been intervened. 11 is a condensing heat exchanger tube, and this heat exchanger tube 11 is connected to the feed water heater 5.
The medium is arranged in the vertical direction through each of the four beds 6, and the medium supplied from below the feed water heater 5 flows upward in the heat exchanger tubes 11. As the medium, for example, pure water, which does not easily precipitate scale or sludge, is used. Reference numeral 12 denotes a waste water heater, which is used to preheat the waste water to be supplied to the evaporator 1 using the thermal energy of pure water led from the upper part of the feed water heater 5. is led to the lower part of the feed water heater 5. Sewage heater 1
As the heat exchanger 2, a heat exchanger that is easy to clean is used, such as a plate heat exchanger or a tubular heat exchanger equipped with a sponge ball cleaning mechanism. 13 is a pump for circulating pure water. Reference numeral 14 denotes a pump connected to the condensate reservoir at the bottom of the uppermost feedwater heating chamber 7a, and external steam supplied from a boiler or the like heats the pure water flowing through the heat exchanger tubes 11 in the uppermost feedwater heating chamber 7a. The condensed water is returned by this bomb 14 to a steam supply source such as a boiler. Reference numeral 15 denotes a pipe line that communicates the upper and lower adjacent feed water heating chambers 7 with each other, and the pipe line 15 is connected to the lower part of the upper feed water heating chamber 7 and the upper part of the lower feed water heating chamber 7. 16 is a valve whose one end is connected to each feed water heating chamber 7 and the other end is connected to a vacuum bong, and the pressure in each feed water heating chamber 7 is lowered by the valve 10.Next, the operation of the above structure will be explained. After being heated by the sewage heater 12, the sewage supplied to the uppermost water chamber 3a of the evaporator 1 flows down into the lower evaporation chamber 3 through the nozzle 4 provided on the floor 2 of the water chamber 3a. , flash evaporates in the lower evaporation chamber 3. The generated steam is guided to the adjacent feed water heating chamber 7 via the mist separator 10, and is condensed by the heat exchanger tube 11 in the feed water heating chamber 7 to become water. The sewage whose moisture level has increased by the amount of water that has evaporated is led from the nozzle 4 on the floor 2 to the evaporation chamber 3 on the lower stage, where it flash-evaporates again, and the generated steam passes through the mist separator 10 to the adjacent water supply heating chamber. 7, condenses in the heat transfer tube 11 and becomes water.The wastewater, which has increased in volume due to repeated flash evaporation, is discharged as concentrated wastewater via the pump 17 and valve 18, and the water can be recovered. If there is not enough water, the water is led back to the evaporator 1 via the valve 19.The water generated in each feed water heating chamber 7 is led to the lower feed water heating chamber 7 through the pipe 15, and It is recovered from the heating chamber 7 via the pump 20 and used for various purposes.The pure water flowing upward in the heat transfer tube 11 is heated by the flash on the outer surface of the wire tube 11, and the steam loses latent heat. The pure water is discharged and becomes condensed water.After being self-heated to the high-temperature stage and gradually raised in temperature, it is heated in the feed water heating chamber 7a of the top stage with steam supplied from an external heat source such as a boiler, and the temperature rises roughly. The heated pure water heats the waste water in the waste water heater 12. In this way, in the above embodiment, the pure water flowing inside the heat transfer tube 11 is preheated by the heat generated by the condensation of the flash steam, and is finally sent to the boiler, etc. The heated purified water is heated by steam supplied from an external heat source, and heated by the sewage heater 12, so that the sewage with a high temperature of 7 degrees can be supplied to the evaporator 1, so that the sewage can be efficiently processed. Flash evaporation can be carried out. Fig. 2 shows another embodiment of the present invention, in which 21 is an evaporator, and the inside of the evaporator 21 has a floor 22 and three levels of water chambers 23a, upper and lower.
, evaporation chambers 23b and 23c, and each of the evaporation chambers 23b and 23c is evacuated to a lower pressure. Each floor 22 has respective evaporation chambers 23h adjacent to each other above and below. A nozzle 24 communicating with 23c is attached. 25 is a feed water heater, and the inside of the feed water heater 25 is a floor 26.
The water supply heating chamber 27a and 27b are divided into three upper and lower stages, and the upper water supply heating chamber 27a and the water 23a at the top stage are adjacent to each other with a partition wall 28 in between. Reference numeral 29 denotes a partition wall having a mist separator 30 attached thereto with a size that allows passage of steam, and the partition wall 29 is interposed between the lower-stage feed water heating chamber 27b and the middle-stage evaporation chamber 23h. 31 is a condensing heat exchanger tube, and this heat exchanger tube 31 is connected to the feed water heater 2.
The deionized water supplied from below the feed water heater 25 flows upward through the heat transfer tubes 31 . Reference numeral 32 denotes a wastewater heater, which is used to preheat the wastewater to be supplied to the evaporator 21 using the thermal energy of pure water led from the upper part of the feedwater heater 25. is fed 59 to the bottom of the feed water heater 25. As the sewage heater 32, a heat exchanger that is easy to clean is used, such as a plate heat exchanger or a tubular heat exchanger with a cleaning attachment attached to a sponge ball. 33 is a pump for circulating pure water. 34 is a steam chamber, and this steam chamber 34 and the lowest evaporation chamber 23c
are partitioned by a wall 3G equipped with a mist separator 35 that allows passage of steam. Reference numeral 31 denotes a steam ejector, and the steam led from the steam chamber 34 to the steam ejector 37 is heated and pressurized by steam supplied from an external heat source such as a boiler, and then is sent together with the steam to the upper feedwater heating chamber 27a. supplied to 38 is a pipe, one end of which is connected to the lower part of the upper feed water heating chamber 27a, and the other end to the lower feed water heating chamber 27b.
Some are connected to each other. Next, the operation in the ":" configuration will be explained. After being heated by the wastewater heater 32, the wastewater supplied to the ice chamber 23a at the top of the evaporator 21 flows down to the evaporation chamber 23tl through the nozzle 24 provided on the floor 22 of the water chamber 23a, and flows into the evaporation chamber 23b. evaporate with flash. The generated steam passes through the mist separator 30 to the adjacent feed water heating chamber 2.
7b, and is condensed into water by the heat transfer tube 31 in the water supply heating chamber 27b. The sewage, whose concentration has increased by the amount of water that has evaporated, flows from the nozzle 24 on the floor 22 to the evaporation chamber 2 on the lower side.
3c and flash evaporates again. The generated steam passes through the mist separator 35 and the steam chamber 34, enters the suction section of the steam ejector 37, and is compressed in the ejector 37 by the steam led from the boiler, etc., and is heated and pressurized. The purified water is guided to the upper water supply heating chamber 27a and condensed, and the heat from the condensation heats the pure water flowing inside the heat exchanger tubes 31. The water generated in the feed water heating chamber 27a is led to the lower feed water heating chamber 27b via a pipe line 38, and is recovered together with the water generated in the feed water heating chamber 27b via a pump 41 and supplied for various uses. be done. The wastewater with an increased waterfall 1α due to flash evaporation of water in the middle and lower evaporation chambers 23b and 23c is pumped to a pump 42.
, and is discharged as concentrated waste water via valve 39, and is led back to evaporator 21 via valve 40 when the moisture recovery is not sufficient. The pure water flowing upward inside the heat exchanger tube 31 is heated by the steam on the outer surface of the wire tube 31 to raise its temperature, and then the upper stage side feed water is heated?
The pure water heated in 27a and heated to an armpit temperature is used to heat wastewater in a wastewater heater 32. In this way, in the embodiment mentioned above, the pure water flowing through the heat exchanger tube 11 is compressed by the heat generated when the flash steam condenses, the steam supplied from an external heat source such as a boiler, and the vapor compressed by the ejector. The heated pure water is heated by the heated and pressurized flash steam, and the heated waste water is heated in the waste water heater 32, so that highly warm and intoxicating waste water can be supplied to the evaporator 21, so that the waste water can be flash-evaporated efficiently. be able to. In addition, in the example described in "-", the flash steam was compressed by a vapor compressor with an ejector set using a steam ejector 37.
Mechanical vapor compressors can also be used. As described in detail, according to the present invention, wastewater is flash-evaporated in the evaporation chamber, and the generated steam is condensed by the heat transfer tube through which a medium that is difficult to deposit scale and sludge flows. It is possible to prevent an increase in the heat transfer resistance of the tube wall due to the adhesion of deposited scale and sludge on the wall surface of the heat tube, thereby making it possible to downsize the device and enable long-term continuous operation. Furthermore, a double grooved tube or the like having good heat transfer characteristics can be used as the heat transfer tube disposed in the feed water heater, so that the device can be downsized. In the embodiment, a stacked structure of the feed water heater and the evaporation chamber has been described, but the feed water heater and the evaporation chamber may be arranged horizontally to perform flash evaporation. 4. Brief Description of the Drawings FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, and FIG. 2 is an overall configuration diagram of another embodiment.

Claims (1)

[Claims] 1. A floor is provided to partition the inside of the evaporator into which wastewater is supplied from above into upper and lower multistage evaporation chambers, a nozzle communicating with the adjacent evaporator is provided on the floor, and a pump is provided to reduce the pressure in each of the evaporation chambers. , a feed water heater is provided in which feed water heating chambers are formed in upper and lower multi-stages to which the steam from each evaporation chamber is guided, a condensing heat exchanger tube is disposed in the feed water heater, and scale and An evaporator characterized by introducing a medium in which sludge does not easily precipitate.