JP2001070701A - Multistage flash evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multistage flash evaporator dispensing with the labor for attaching a ring to each condensing pipe and the production cost of the ring, ensuring airtightness, simple in structure and easy to produce. SOLUTION: A multistage flash evaporator has the condensing pipe bundle piercing the partition 7 between two condensing chambers different in pressure and is equipped with two vertical plates 21 having a large number of through- holes 21a through which the respective condensing pipes 5a of the condensing pipe group are inserted and the granular packing material 26 charged in the gap between both vertical plates 21. As the granular packing material 26, silica sand or gypsum having a particle size smaller than the gap between each condensing pipe 5a and the peripheral edge of each through-hole 21a. In the case of silica sand, silica sand is easily injected in the gap between both vertical plates and can be taken out of the gap between them if necessary. In the case of gypsum, gypsum is reacted with water to be solidified and the gaps between particles are eliminated to enhance sealability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-stage flash evaporator used for desalination of seawater and the like.

[0002]

2. Description of the Related Art In recent years, as a multi-stage flash evaporator for seawater desalination, one in which two evaporation stages and a condensing chamber are formed in one housing to improve the efficiency has been widely used. In such a multi-stage flash evaporator, the condensing tube bundle of each housing passes through a partition plate provided at the center, and two condensation chambers having different pressures are formed in each housing by the partition plate.

[0003] The seal between the peripheral surface of the through hole of the partition plate into which each condenser tube is inserted and the outer peripheral surface of the condenser tube is provided with a fiber expansion ring that expands in a steam atmosphere. Fitting is performed by expanding the ring to fill the gap between the peripheral surface of the through hole of the partition plate and the outer peripheral surface of the condenser tube.

[0004]

In the above-mentioned conventional multi-stage flash evaporator, not only the number of condenser tubes provided in one housing is large, but also the number of housings is about 20, and these housings are arranged in a plurality of rows. Since it is sometimes installed, it is necessary to fit an enormous number of rings into the condenser tube, and there has been a problem that the time required to attach the ring to each condenser tube and the ring manufacturing cost are increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-stage flash evaporator which has a simple structure and is easy to manufacture by eliminating the trouble of attaching a ring to each condenser tube and the cost of manufacturing the ring, and ensuring airtightness. It is in.

[0006]

SUMMARY OF THE INVENTION A multi-stage flash evaporator according to the present invention is a multi-stage flash evaporator having a condenser tube bundle penetrating a partition between two condensing chambers having different pressures. It is characterized by comprising two vertical plates having a large number of through holes into which the respective condensation tubes are inserted, and a granular filler filled between the vertical plates.

As the particulate filler, silica sand or gypsum having a particle size smaller than the gap between the condensation tube and the periphery of the through hole is preferable. In the case of silica sand, it has the advantage that it can be easily poured between the two vertical plates and can be taken out as needed.In the case of gypsum, it reacts with moisture and solidifies, thereby reducing This has the advantage that the gap is eliminated and the sealing property is improved.

When the granular filler fills the space between the two vertical plates, the steam flowing into the space between the two vertical plates from between the periphery of the through hole of the vertical plate on the high pressure side and the condenser pipe penetrates the vertical plates on the low pressure side. Outflow from the periphery of the hole and the condensing tube is prevented, and sufficient airtightness is ensured.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In this specification, the front, rear, left and right are shown in FIG.
, The front side of the drawing is referred to as front, the back side is referred to as rear, and the left and right of FIG. Note that the front, rear, left, and right are for convenience, and the front, rear, left, and right may be used in reverse.

FIGS. 1 to 5 show a part of a multi-stage flash evaporator according to the present invention.

The illustrated multi-stage flash evaporator is used for desalination of seawater, and has a large number of long housings (1) arranged front and rear, which are arranged side by side on the left and right, and a lower part of the housing (1). Is an evaporation chamber (2), and the upper part is a condensation chamber (3).

The evaporating chamber (2) includes a condensed liquid receiver (6), an evaporating chamber extending back and forth between the left and right central portions of the bottom wall (6c) and the housing (1) right and left central portions of the bottom wall (1c). The middle stage (4) allows the left (hot side) evaporation stage (2a) and the right (low temperature side) evaporation stage (2b)
It is divided into and. At the lower edge of the left side wall (1a) of the housing (1) and the lower edge of the center partition (4) of the evaporating chamber, a number of orifices through which seawater (heated brine) flows are provided.
(10) is provided. Although not shown, the right end housing (1) is suctioned by a vacuum pump, and the seawater introduced into the left end housing (1) is caused to flow downstream through the orifice (10), whereby each housing (1) is sucked. Each of the evaporation stages (2a) and (2b) in (1) is maintained at a low pressure gradually (at a temperature of 2 ° C.) from left to right.

Downstream of the orifice (10), submerging weirs (13) having a horizontal wall (14) at the upper edge are provided.
Above this, a brine splash prevention plate (15) is provided horizontally. Seawater flowing into the housing (1)
The vaporization is promoted by getting over the dive weir (13), and the penetration of the bumped water droplets into the condensation chamber (3) is prevented by the brine splash prevention plate (15).

The condensing chamber (3) includes a bundle of condensing tubes having a circular vertical cross section which extends back and forth over the upper part of the left and right central portions of each housing (1).
(5) is provided, and a gutter-shaped condensed liquid receiver (6) for receiving liquid condensed on the outer peripheral surface of each condensing tube is provided below the condensing tube bundle (5). Between the upper edge of the left side wall (6a) of the condensate receiver (6) and the left side wall (1a) of the housing (1) and the upper edge of the right side wall (6b) of the condensate receiver (6) and the right side of the housing (1). A demister (mesh) (8) for capturing water droplets accompanying the steam is provided horizontally between the wall and the wall (1b).

The condensing chamber (3) is provided at the center before and after the condensing pipe bundle (5), and has a condensing chamber center partition (7) through which each condensing pipe (5a) passes. 6a) A cross section 4 extending between the upper edge and the left and right central portions of the housing top wall (1d) along the outer surface of the front half of the condenser tube bundle (5) and covering the outer periphery of the left front half of the condenser tube bundle (5). 1 / arc shaped condensation chamber left half partition
(11), the upper edge of the condensate receiving right side wall (6b) and the housing top wall (1
d) extending along the outer surface of the rear half of the condenser bundle (5) between the left and right central parts, and covering the outer periphery of the right rear half of the condenser bundle (5); It is partitioned by the second half partition (12). These three partitions (7) (11) (12)
The condensing tube bundle (5) of the vapor evaporated in the left evaporation stage (2a)
Inflow into the inside is limited only from the latter half, and the right evaporation stage
The flow of the vapor evaporated in (2b) into the condenser tube bundle (5) is limited only from the first half. Thus, the condensation chamber (3)
Is divided into a high pressure side condensation chamber (3a) in the second half having a small pressure difference and a low pressure side condensation chamber (3b) in the first half.

The condensing chamber (3) also has a vertical central baffle (1) provided over the entire length of the upper center in the condensing tube bundle (5).
6), a horizontal left front half baffle (17) provided in the front half of the center left portion in the condenser tube bundle (5), and a horizontal right baffle plate (17) provided in the middle right portion of the condensation tube bundle (5). Horizontal right back half baffle
(18) is provided. The upper edge of the vertical central baffle (16) is joined to the housing top wall (1d), and the left edge of the horizontal left front half baffle (17) is the left side wall (6a) of the condensate receiver.
It is joined to the upper edge and a horizontal right rear half baffle (18)
Is joined to the upper edge of the right side wall (6b) of the condensate receiver. Then, the condensation chamber left front half partition (11) is sandwiched between near the upper edge of the central baffle (16) and near the left edge of the left front half baffle (17), and the condensation chamber right rear half partition (11). 12) is sandwiched near the upper edge of the central baffle (16) and near the right edge of the right rear half baffle (18).

The condensing chamber center partition (7) is provided with two vertical plates (21) having a large number of through holes (21a) through which the condensing tubes (5a) of the condensing tube bundle (5) are inserted. , These vertical plates (21)
By filling the gap with the particulate filler (26), airtightness between the high pressure side condensation chamber (3a) in the second half and the low pressure side condensation chamber (3b) in the first half is ensured. The distance between the two vertical plates (21) is
It is about 50mm, the upper part is semicircular, and the lower part is square.

As shown in detail in FIG. 4, the condensing chamber center partition (7) further includes a semi-arc-shaped lid (22) connecting the upper parts of both vertical plates (21). (22) is provided with an inlet cap (23) for injecting the granular filler (26) between the two vertical plates (21). The lower portions of the vertical plates (21) are connected to each other by a condensate receiver (6).
The bottom wall (6c) of the condensate receiver (6) connecting the lower parts of 1)
In the part, a drain (24) for removing water droplets collected between the two vertical plates (21), and an outlet cap (25) for removing the particulate filler (26) from between the two vertical plates (21). Is provided.

As the granular filler (26), silica sand or gypsum is preferable, and as shown in FIG.
The gap (G) between the periphery of the through hole (21a) and the condenser tube (5a) in (1) is smaller than the gap (G). Here, the outer diameter of the condensation tube (5a) varies depending on the order of the stage in one multi-stage flash evaporator, but the basic condensation tube (5a) is, for example, 25.2 mm. The tolerance is -0.11 to +0.11 mm, whereas the diameter of the through hole (21a) of the vertical plate (21) is 2
At 5.4mm, its tolerance is -0.02 ~ + 0.12mm. Therefore, the gap (G) between the periphery of the through hole (21a) and the condenser tube (5a) has a minimum value of 25.38-25.31 = 0.07 mm and a maximum value of 25.52-25.0
9 = 0.43 mm. That is, the particle size of the particulate filler (26) is 0.
If it is not less than 07 mm, the particulate filler (26) does not flow out of the gap (G) between the periphery of the through hole (21a) and the condensation pipe (5a). Thereby, the steam flowing into the space between the two vertical plates (21) from between the periphery of the through-hole (21a) of the high-pressure side vertical plate (21) and the condensation pipe (5a) is transferred to the low-pressure side vertical plate (21). Through hole (21a) and condensing tube (5a)
Is prevented from flowing out of the space. Compared to the conventional case where one ring is fitted into each condenser tube, even if the variation of the through hole (21a) is large, the effect on the sealing performance is small, so the processing accuracy of the through hole (21a) is small. Does not need to be particularly strict, and the manufacture of the multi-stage flash evaporator becomes easy.

In the above-mentioned multi-stage flash evaporator, the seawater introduced into the leftmost housing (1) is sequentially supplied to the orifice (1).
When the water flows into all the housings (1) via the (0), the seawater that has flowed over the submerging weir (13) is flash-evaporated in each of the evaporation stages (2a) and (2b) of each housing (1). The generated water vapor is accompanied by minute water droplets containing salt, and the demister (8)
, During which minute water droplets containing salt are separated from water vapor. Then, the water vapor of the left evaporation stage (2a) flows into the condenser tube bundle (5) of the second half condensation chamber (3a), where it is cooled to condensed water, and the water vapor of the right evaporation stage (2b) Flows into the condensing tube bundle (5) of the condensing chamber (3b) in the first half, where it is cooled to condensed water. Thus one housing
In (2), two-stage flash evaporation is performed, and the seawater is desalinated.

[0022]

According to the multi-stage flash evaporator of the present invention, sufficient airtightness can be obtained by filling the granular filler between the two vertical plates, and no special processing for manufacturing a partition is required. In addition, since it is not necessary to make the processing accuracy of the through-hole strict, the structure is simple and the production becomes easy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a multi-stage flash evaporator according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the first half of the multi-stage flash evaporator of FIG.

FIG. 3 is an enlarged cross-sectional view of the first half.

FIG. 4 is an enlarged cross-sectional view showing a main part of the multi-stage flash evaporator according to the present invention.

FIG. 5 is an enlarged vertical sectional view of the same.

[Explanation of symbols]

 (1) Housing (3a) (3b) Condenser (5) Condenser tube bundle (5a) Condenser tube (7) Partition (21) Vertical plate (21a) Through hole (26) Granular filler

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Imabayashi 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi Inside Tachibana Shipbuilding Co., Ltd. (72) Inventor Kiichi Nagaya 1-chome 7 Minami-Kohita, Suminoe-ku, Osaka-shi No. 89 Inside Nippon Shipbuilding Co., Ltd. (72) Masaharu Furuji, 1-7-7 Minami Kohoku, Suminoe-ku, Osaka City 89 Inside Nippon Shipbuilding Co., Ltd. Hiroyuki Otsuka 1-7-7 Minami Kohoku, Suminoe-ku, Osaka City No. 89 T-Shipbuilding Co., Ltd. F-term (reference) 4D034 AA01 BA03 CA13 4D076 BB19 BB20 HA02 JA03

Claims (3)

[Claims] A multi-stage flash evaporator having a condenser tube bundle (5) penetrating a partition (7) between two condensation chambers (3a) (3b) having different pressures, wherein the partition (7) Two vertical plates (21) having a large number of through-holes (21a) through which each condensation tube (5a) of the tube bundle (5) is inserted;
A multi-stage flash evaporator comprising a granular filler (26) filled between both vertical plates (21). 2. A filler (26) is provided between the condenser tube (5a) and the through hole (21).
The multi-stage flash evaporator according to claim 1, wherein a) silica sand having a particle size smaller than a gap with the periphery. 3. A filler (26) is provided between the condenser tube (5a) and the through hole (21).
The multi-stage flash evaporator according to claim 1, wherein a) is gypsum having a particle size smaller than a gap with the periphery.