JP2001047032A - Vertical multi-stage flash distilling plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical multi-stage flash distilling plant which can reduce its installation area by arranging independent modules vertically in multi-stages to be compact in structure. SOLUTION: A plate type heat exchanger 3 and a demister 4 are installed in a shell 1, and seawater is supplied from a cooled seawater inlet pipe 5 to the heat exchanger 3, heat-exchanged with steam in the heat exchanger 3, condensed, and discharged from a cooled seawater outlet pipe 6. Seawater is introduced from a flash seawater inlet pipe 7 into an evaporation chamber 10 in the bottom part of the shell 1 and sprayed from a spray nozzle 9.A part of the sprayed seawater is evaporated, salt components are removed by the demister 4, the steam is condensed by the heat exchanger 3, the water is retained in a produced water retention part 11 and discharged from a produced water outlet pipe 12. The unevaporated seawater is discharged from a flash seawater outlet pipe 8. The shells are arranged vertically in multi-stages and connected to constitute a distilling plant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical multi-stage flash fresh water generator, in which modules for producing water by evaporating sea water are vertically arranged in multiple stages to reduce the installation space, improve the pressure resistance of the module, and improve efficiency. This is a desalination device that enables good desalination.

[0002]

2. Description of the Related Art In a conventional seawater desalination (desalination) apparatus, a seawater evaporation chamber and a condensing condenser are incorporated in a cubic casing to constitute one stage, and a plurality of stages are connected in series. And are arranged on a plane. FIG. 4 is a configuration diagram of a typical conventional multi-stage flash fresh water generator.

In the figure, an evaporator body 60 of a multi-stage flash fresh water generator has a heat recovery section (Heat Recovery Sectio).
n) (A) and Heat Rejection Section
(B), and a box 61 is connected to each part in multiple stages in a horizontal direction. 50 is seawater (brine)
It is a pump that sends seawater into the heat transfer tube 51 and circulates it between the boxes 61 at the last stage of the heat release part (B). 5
Reference numeral 2 denotes a seawater pump, which sends seawater from the tube 58 into each box 61 of the heat release section (B) to condense the internal steam. 53 is a deaerator for removing air in seawater, and 54 is a pipe for discharging gas from the deaerator 53 to the ejector 5.
Send to 6. A pipe 55 also sends gas from each box 61 to an ejector 56. Reference numeral 57 denotes a pipe, which is a channel for supplying seawater.

Reference numeral 62 denotes a brine heater for heating brine (seawater) circulated by a heating steam source 63;
Reference numeral denotes a flash box into which seawater (brine) flows, reference numeral 65 denotes an evaporation chamber, and reference numeral 66 denotes a retention portion of condensed water.
Reference numeral 67 denotes a demister for removing salt in the steam. 68 is a pipe for taking out condensed water, 69
Is a pump for taking out the production water to the outside, and 70 is a blowdown pump for adjusting the amount of brine (seawater).

In the above configuration, seawater is taken in from seawater by a pump, and the heat transfer tube 5 is fed by a seawater pump 50.
1, passes through the heat transfer tubes in the box 61 at the last stage of the heat recovery section (A), flows through the heat transfer tubes 51 in the sequentially connected boxes, and flows out of the box 61 in the first stage.
The heat recovery unit (A) is composed of several tens of stages of boxes 61 connected horizontally, and the seawater (brine) absorbs the heat of the steam in the boxes 61 while passing through each box 61, and the temperature rises. Then, they sequentially flow to the next stage. Seawater (brine) that exited the first-stage box 61 of the heat recovery unit (A)
Flows into the brine heater 62, is heated by the steam from the heating steam source 63 in the brine heater 62, and is returned to the flash box 64 in the first-stage box 61 of the heat recovery unit (A) again.

Seawater heated by the brine heater 62 is
The flash is flashed in the first-stage flash box 64 of the heat recovery section (A), and a part of the flash box 64 evaporates in the box 61 as steam, and flows into the flash box 64 of the next stage. Evaporates inside.
The box 61 of each stage is a flash box 64
, An evaporating chamber 65, a water retaining section 66, and a demister 67, and a heat transfer tube 51 passes through the inside. The incoming seawater enters the flash box 64, a part of which evaporates, and the rest flows to the flash box 64 of the adjacent box 61. The evaporated steam is separated in salt content by the demister 67, gives latent heat to the seawater in the tube 51 on the surface of the heat transfer tube 51, condenses and becomes water, and accumulates in the water retaining portion 66.
Similarly, at each stage, the inflowing seawater evaporates and condenses, and water accumulates in the water retaining portion 66. The water is collected by a pipe 68, taken out by a pump 69, and desalted water can be obtained.

Seawater is supplied from a seawater pump 52 to a tube 58.
Is sent to the box 61 at the last stage of the heat rejection section (B), and after a part of the steam in the box is condensed, an agent for preventing the generation of scale is added, and guided to the deaerator 53 to be degassed. The seawater discharged from the pipe 57 is supplied to the box 61 at the last stage of the heat rejection section (B).
It is supplied to the inside and circulated by the pump 50. The gas from the deaerator 53 is guided from the pipe 54 to the ejector 56 and discharged to the outside.

[0008]

In the above-mentioned conventional seawater desalination apparatus, the heat recovery section (A) and the heat release section (B) are used.
Since the boxes 61 are arranged in series on a plane, the apparatus requires a flat and large installation area. Further, the box 61 is a box type, requires a large amount of reinforcing material in terms of pressure resistance design, increases the weight, and has room for improvement.
Further, since the heat transfer tube is used, the efficiency of heat exchange is poor, the required heat transfer area is increased, the apparatus main body is large, the number of manufacturing steps is increased, and some improvement has been desired.

In view of the above, the present invention employs a single module having a common independent structure, reduces the required installation area by stacking the modules in a plurality of stages in the height direction, and uses a plate-type heat exchanger. An object of the present invention is to provide a vertical multi-stage flash fresh water generator that employs a heat exchanger and increases the heat transfer efficiency to make the apparatus compact.

[0010]

The present invention provides the following means (1) to (6) to solve the above-mentioned problems.

(1) A plurality of desalination units having a heat exchanger for condensing steam condensed in the evaporating chamber with seawater for cooling and condensing steam with cooling seawater, and connecting the evaporating units for guiding and evaporating seawater, In a multi-stage flash fresh water generator in which the remaining seawater that does not evaporate in the fresh water generating section is sequentially flowed into the next-stage fresh water generating section, the fresh water generating section is composed of independent modules, and a plurality of the same modules are sequentially connected by piping. Characteristic vertical multi-stage flash fresh water generator.

(2) The vertical multistage flash fresh water generator according to (1), wherein the plurality of modules are arranged in a vertical direction.

(3) The vertical multi-stage flash fresh water generator according to (1), wherein the heat exchanger is a plate heat exchanger.

(4) The vertical multistage flash fresh water generator according to (1), wherein the module has a cylindrical shape.

(5) The vertical multi-stage flash fresh water generator according to (1), wherein the seawater guided to the evaporating section is sprayed from a spray nozzle.

(6) The cooling seawater flows in from the lowermost module, is sequentially sent to the upper module, flows out from the uppermost module, and the seawater flowing out from the uppermost module flows to the lower module and flows therefrom. (1) to (6), wherein seawater which does not evaporate is sprayed into the module and evaporated, and seawater which does not evaporate is sequentially sent to the lower stage to be sprayed and evaporated.
The vertical multistage flash fresh water generator according to any one of the above.

The vertical type multi-stage flash fresh water generator of the present invention is based on the invention of (1). The fresh water producing unit is an independent module. The module has an evaporation chamber and a heat exchanger. Are arranged independently of each other, and each module is connected by a pipe to form a multistage fresh water generator. Therefore, unlike the conventional case, it is not necessary to adopt a configuration in which the units are continuously integrated in multiple stages in the horizontal direction, and a stand or the like can be assembled and arranged in the space, so that the installation area can be reduced.

In (2) of the present invention, since the modules are arranged vertically, the installation area can be further reduced. In (3) of the present invention, the heat exchanger can be replaced by a plate type from the conventional tube heat transfer system. Since the heat exchanger is used, the heat transfer efficiency of the heat exchanger is improved, and in the invention of (4), since the module is formed in a cylindrical shape, the reinforcement of the pressure-resistant structure may be reduced as compared with the conventional box type. Further, in the invention of (5),
In the evaporating section, the seawater is sprayed by the spray nozzle, so that the evaporation of the seawater is good and the fresh water producing efficiency is improved.

Further, in (6) of the present invention, the cooling seawater flows in from the lowermost stage, flows to the uppermost stage, and the seawater from the uppermost stage is sequentially dropped by gravity into the lower module as seawater for flashing. The seawater evaporated in the module and the non-evaporated seawater flows to the lower stage, so that a spray pump is not required and the equipment is simplified.

[0020]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a perspective view showing a basic module of a vertical multi-stage flash fresh water generator according to the first and second embodiments of the present invention. In the figure, 1 is a cylindrical shell, and 2 is its reinforcing material. Reference numeral 3 denotes a plate heat exchanger provided inside the shell 1, and reference numeral 4 denotes a plate for separating steam generated by the demister into seawater. Reference numeral 5 denotes a cooling seawater inlet pipe, which flows into the plate heat exchanger 3 and cools a plurality of plates in the plate heat exchanger 3 with seawater to condense steam. Reference numeral 6 denotes a cooling seawater outlet pipe, which is an outlet for seawater that is cooled by the plate heat exchanger 3 to condense the steam and is heated by the absorbed heat.

Numeral 7 denotes a flush seawater inlet pipe, two of which are arranged in an evaporation chamber 10 at the bottom of the shell 1, provided with a number of nozzles 9, and seawater for flash is sprayed into the evaporation chamber 10 from the nozzles 9. Is done. Numeral 8 denotes a flush seawater outlet pipe, which is similarly provided in two pipes and out of the seawater sprayed from the nozzle 9, the seawater collected on the bottom surface of the evaporation chamber 10 without evaporating flows out.

In the module having the above structure, the cooling seawater is introduced into the shell 1 from the cooling seawater inlet pipe 5, and a large number of plates are cooled in the plate heat exchanger 3 and then out of the cooling seawater outlet pipe 6 to the outside of the shell 1. leak. The seawater flowing out from the cooling seawater outlet pipe 6 is used as cooling seawater for a shell to be connected next. On the other hand, the seawater for evaporation flows to the two flush seawater inlet pipes 7 and the shell 1 from many nozzles 9.
Is sprayed into the evaporating chamber 10 at the bottom.

Part of the sprayed seawater evaporates in the evaporation chamber 10, and the rest accumulates at the bottom of the evaporation chamber 10. The evaporated vapor is desalted by the demister 4, passes upward through the demister 4, is cooled by the surface of the plate heat exchanger 3, condenses and condenses, and the condensed water is cooled by the plate heat exchange It falls and accumulates in the production water retaining section 11 immediately below the vessel 3. on the other hand,
The seawater that has not evaporated and has accumulated on the bottom of the evaporation chamber 10 flows out of the shell 1 through the two flush seawater outlet pipes 8,
It is used as seawater for flushing the next module.
The water accumulated in the production water retaining section 11 becomes desalted water and is taken out of the shell 1 through the production water outlet pipe 12.

FIG. 2 is a perspective view showing the entire configuration of a vertical multi-stage flash fresh water generator according to a second embodiment of the present invention. In the figure, up to the third stage from the upper right side in the figure corresponds to the conventional heat rejecting section (B) shown in FIG. 3, and the lower and left 5 stages of the shell correspond to the heat recovery section (A). . As shown in the figure, in the present embodiment, a module comprising a shell 1 is vertically connected in multiple stages.

In FIG. 2, the cooling seawater flows from the cooling seawater inlet pipe 5 of the uppermost shell 1a from the upper line (2) on the left side in the figure, enters the plate heat exchanger 3, and after the heat exchange. Seawater flows out of the shell 1a from the cooling seawater outlet pipe 6, flows into the cooling seawater inlet pipe 5 of the lower shell 1b, flows out of the outlet pipe 6 of the shell 1b, and thereafter flows into the shells 1c and 1d in the same manner. To exchange heat with the plate heat exchanger 3 between the shells. Cooling seawater outlet pipe 6 of shell 1d
The seawater that has flowed out flows into the cooling seawater inlet pipe 5 of the shell 1e.

The seawater flowing out of the cooling seawater outlet pipe 6 of the shell 1e is heated by steam in each plate type heat exchanger 3 and its temperature is increased. The seawater is pressurized by the spray pump 20 and is supplied to the upper shell 1d. It flows into the evaporation chamber 10 of the shell 1d from the flash seawater inlet pipe 7 and is sprayed from the nozzle 9. In the evaporation chamber 10 of the shell 1d, a part thereof evaporates, the salt is removed by the demister 4, cooled by the plate heat exchanger 3 and condensed, and water is taken out from the production water outlet pipe 12.
The seawater that has not evaporated flows out of the shell 1d from the flush seawater outlet pipe 8, and is supplied to the spray pump 2 for the next 1d.
0 is used as seawater for flushing the upper shell 1c.

Similarly, the spray pump 20 of the shell 1d
From the flash seawater inlet pipe 7 of the shell 1c flows into the shell 1c, where water is produced, and the remaining seawater flows out of the flash seawater outlet pipe 8,
In the same manner, the remaining flush seawater flowing from the shell 1c to the shell 1b, further flowing into the shell 1a, and flowing out from the flash seawater outlet pipe 8 of the shell 1a is supplied to the flash seawater inlet of the next shell 1i by the spray pump 20 of the shell 1a. Flow into tube 7. Hereinafter, similarly, the shell 1i of the heat emitting portion (B)
Flows through the shell 1f through 1h and 1g from the shell 1f.
Out of the shell 1f from the cooling seawater outlet pipe 8 of the shell 1f, and a part of the seawater is supplied to the cooling seawater inlet pipe 5 of the shell 1i to be blowdown seawater.

In the heat release section (B), the shell 1
f, the seawater flows in from the cooling seawater inlet pipe 5 and heat is exchanged in the plate heat exchanger 3 to condense the steam. After flowing into the shell 1g, similarly, it flows into the shell 1h from the shell 1g, and flows out from the cooling seawater outlet pipe 6 of the shell 1h.

As described above, in the first embodiment of the present invention, by arranging the shells 1 vertically in multiple stages,
In the illustrated example, the water obtained from the shells 1a, 1b, and 1c was combined with the water of the shell 1d, taken out, and obtained from the shells 1f, 1g, and 1h. The water merges with the shell 1i and is taken out. According to the desalination apparatus of the first embodiment, the shells 1 of the independent modules are vertically arranged in multiple stages and connected by piping, so that the installation area is significantly reduced, and the plate type heat exchanger is provided. 3 can be incorporated into the shell 1 to form a compact independent module. Further, since the shell 1 is made cylindrical from the conventional box type, there is an advantage that reinforcement in the pressure resistance design can be reduced.

FIG. 3 is a perspective view showing the overall configuration of a vertical multi-stage flash freshwater generator according to a second embodiment of the present invention.
A feature of the second embodiment is that, compared to the first embodiment shown in FIG. 2, the flow of the cooling seawater is inverted, and the cooling seawater flows from the lowermost stage of the multi-staged shell 1 and flows sequentially to the upper stage. Further, the cooling seawater flowing out of the uppermost shell is caused to flow down to the lower stage by gravity to evaporate, and the seawater that does not evaporate is sequentially dropped to the lower stage to evaporate. Hereinafter, the second embodiment of the present invention will be described with reference to FIG. 3 while referring to a detailed view of the shell 1 in FIG.

In FIG. 3, first, in the heat recovery section,
The seawater sent from the cooling seawater supply pump 30 flows into the cooling seawater inlet pipe 5 of the lowermost shell STG 19, enters the plate heat exchanger 3, cools the inside, and cools the inside of the cooling seawater outlet pipe 6
It then flows out and flows into the cooling seawater outlet pipe 5 of the upper shell STG 18, where it similarly enters the plate heat exchanger 3 to cool the inside.

The seawater flowing out of the outlet pipe 6 of the STG 18 enters the cooling seawater inlet pipe 6 of the upper STG 17, similarly cools the plate heat exchanger 3 and flows out of the cooling seawater outlet pipe 6 to the deaerator 32. The seawater heated by the deaerator 32 is sent to the cooling seawater inlet pipe 6 of the shell STG16 of the heat recovery unit by the brine circulation pump 31.
The flow from 17 to STG10 to STG1 cools the plate heat exchanger 3 inside each shell.

The seawater flowing out of the cooling seawater outlet pipe 6 of the shell STG1 flows into the upper brine heater 34, where it is heated by steam, and the seawater flowing out of the cooling seawater outlet pipe 6 of the brine heater 34 is supplied to the lower stage. It flows into the two flash seawater inlet pipes 7 of the STG 1 and is sprayed from the nozzle 9. In the evaporation chamber 10 of the shell STG1, a part is evaporated and the salt is removed by the demister 4, and the plate heat exchanger 3
The water is cooled and condensed, and is taken out from the production water outlet pipe 12 as water.

The seawater which has not evaporated flows out of the flash seawater outlet pipe 8 through the shell STG1 and falls by gravity into the two flash seawater inlet pipes 7 of the lower shell STG2. More sprayed. In the same manner, the seawater that has not evaporated is successively replaced with the lower shell STG3.
ＳＴSTG9, STG10, 〜STG19 to sequentially evaporate seawater and flow out from the production water outlet pipe 12 of the shell of each STG.

The remaining non-evaporated seawater flowing out of the flush seawater outlet pipe 8 of the lowermost shell STG 19 flows from the brine circulation pump 31 into the cooling seawater inlet pipe 6 of the shell STG 16 as described above, and is cooled. It flows sequentially to the upper stage as seawater and circulates.

Production water flowing out of the production water outlet pipe 12 of each of the shells STG1 to STG19 is collected by a blowdown water pump 33 and guided to a production water outlet (not shown).

As described above, according to the second embodiment of the present invention, STG1 to STG3 are provided in the heat releasing section, and STG is provided in the heat recovery section.
4 to STG 19 are arranged in a plurality of stages, and cooling seawater flows in from the lowermost shell STG19, flows sequentially to the upper stage, and heats the seawater flowing out from the uppermost stage of the STG1 by the brine heater 34, and sequentially cools the lower flashing stage. It is made to flow into the seawater inlet pipe 7, spray from the nozzle 9 and evaporate, and the seawater which does not evaporate is sequentially dropped to the lower stage by gravity and evaporated. With such a configuration, a plurality of spray pumps 20 in each stage, which are required in the first embodiment shown in FIG. 2, are not required, and the cost of the equipment can be significantly reduced.

[0038]

According to the vertical multistage flash fresh water generator of the present invention, (1) an evaporator for guiding and evaporating seawater and a heat exchanger for condensing steam evaporated in the evaporation chamber with seawater for cooling and condensing water. In a multi-stage flash fresh water generator in which a plurality of fresh water generating units are connected and configured, and the remaining seawater that does not evaporate in each of the fresh water generating units is successively flowed to the next-stage fresh water generating unit, the fresh water generating unit is an independent common water generating unit. It is made up of modules, and a plurality of the modules are sequentially connected by piping.
According to such a configuration, it is not necessary to adopt a configuration in which the frames are continuously integrated in the horizontal direction as in the related art, and it is possible to arrange the gantry or the like in the space, and thus to reduce the installation area.

In (2) of the present invention, since the modules are arranged vertically, the installation area can be further reduced. In (3) of the present invention, the heat exchanger can be replaced by a plate type from the conventional tube heat transfer system. Since the heat exchanger is used, the heat transfer efficiency of the heat exchanger is improved, and in the invention of (4), since the module is formed in a cylindrical shape, the reinforcement of the pressure-resistant structure may be reduced as compared with the conventional box type. Further, in the invention of (5), since seawater is sprayed by the spray nozzle in the evaporating section, the evaporation of seawater is good and the fresh water producing efficiency is improved.

Further, in (6) of the present invention, the cooling seawater flows in from the lowermost stage, flows to the uppermost stage, and the seawater from the uppermost stage is sequentially dropped by gravity into the lower-level module as flashing seawater. Evaporated in the module,
Since the non-evaporated seawater flows to the lower stage, a spray pump is not required, and the equipment is simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shell used in a vertical multi-stage flash fresh water generator according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the overall arrangement of the vertical multi-stage flash fresh water generator according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing the overall arrangement of a vertical multi-stage flash fresh water generator according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional multi-stage fresh water generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shell 2 Reinforcement material 3 Plate heat exchanger 4 Demister 5 Cooling seawater inlet pipe 6 Cooling seawater outlet pipe 7 Flash seawater inlet pipe 8 Flash seawater outlet pipe 9 Spray nozzle 10 Evaporation room 11 Production water retention part 12 Production water outlet pipe 20 Spray pump 30 Cooling seawater supply pump 31 Brine circulation pump 32 Dealator 33 Blowdown pump 34 Brine heater

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenji Tanaka 1-1, Akunouramachi, Nagasaki-shi F-term in Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. 4D034 AA01 BA03 CA13 4D076 BB19 BB20 CD21 CD25 DA12 FA34 HA02 JA03

Claims (6)

[Claims] 1. A plurality of desalination units having a heat exchanger for condensing steam condensed in said evaporating chamber with seawater for cooling and condensing the water with an evaporating unit for guiding and evaporating seawater;
In the multi-stage flash fresh water generator in which the remaining seawater that does not evaporate in each of the fresh water generating units is successively flown into the next-stage fresh water generating unit, the fresh water generating unit includes an independent module, and a plurality of the modules are sequentially connected by piping. A vertical multi-stage flash fresh water generator characterized by the above-mentioned. 2. The vertical multistage flash fresh water generator according to claim 1, wherein the plurality of modules are arranged in a vertical direction. 3. The vertical multistage flash fresh water generator according to claim 1, wherein said heat exchanger is a plate heat exchanger. 4. The vertical multi-stage flash fresh water generator according to claim 1, wherein the module has a cylindrical shape. 5. The vertical multi-stage flash fresh water generator according to claim 1, wherein the seawater guided to the evaporator is sprayed from a spray nozzle. 6. The cooling seawater flows in from the lowermost module, is sequentially sent to the upper stage, flows out from the uppermost module, and the seawater flowing out from the uppermost module flows into the lower module and is sent to the lower module. The vertical multi-stage flash fresh water generator according to any one of claims 1 to 5, wherein the sea water is sprayed and evaporated inside, and seawater that does not evaporate is sequentially sent to a lower stage to spray and evaporate.