JPS59208391A - Liquid dispersing apparatus - Google Patents

Abstract

PURPOSE:To contrive to make a uniform film when liquid drips along the outer wall of a heat transfer pipe in a heat exchanger which is a stand pipe type and a film is formed by the liquid dripping along the outer wall of a pipe, by controlling the depth of liquid in the upper part of weirs and the rate of liquid dripping along the outer wall of a heat transfer pipe in a liquid rate controlling part, and by uniformly dispersing liquid by a filmy liquid-flow forming part, regardless of the depth of liquid and the liquid rate. CONSTITUTION:In order to branch off and deviate the flow of liquid injected from the opening 15 of a liquid rate controlling part 13, the width and the shape of a dispersing weir 17 are determined by the speed of liquid flow injected from the opening 15, that is the depth of liquid in the upper part of a liquid disperser 10. The width of a weir 17 is desirable, however, to be wider than the width of an opening 15. The thickness of the protrudent part 14 of a liquid rate controlling part 13 and that of the weir 17 of a filmy liquid-flow forming part 16 are arbitrarily selective if the thickness is strong enough not to be broken when a heat transfer pipe is oscillated. The length of a branched-off flow deviation chamber 19 is selective if the liquid dripping from the opening 15 of a liquid rate controlling part 13 can flow smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid disperser, and more particularly to a liquid disperser installed in a vertical thin film falling heat exchanger having vertically mounted heat transfer tubes.

Conventionally, this type of heat exchanger uses an outside-tube heating method in which the liquid to be heated flows down into a heat transfer tube installed vertically, forming a thin film of the liquid to be heated on the inner wall of the heat transfer tube, and heating from the outer wall of the heat transfer tube. there were. For this reason, if the heating source is a dirty or corrosive fluid, not only the outer surface of the heat exchanger tube but also the heat exchanger body will corrode, making it difficult to select the external material and take structural considerations into account. This has the disadvantage that the selection range of sources is limited.

However, for such a heat exchanger, if a heating source of corrosive fluid is passed through the heat transfer tube and a thin film of the heated liquid for cooling is made to flow down the outer wall of the tube, the problem of sloping can be solved. On the other hand, it is relatively easy to deal with this problem because only the heat exchanger tubes need to be made of a corrosion-resistant material. Such a heat exchanger is
It is already known as a vertical type external thin film falling type heat exchanger.

This vertical external thin film falling type heat exchanger allows the liquid to be heated to flow down in a thin film form from the top of the heat transfer tube along the outer wall of the tube, and exchanges heat with the heating source flowing inside the heat transfer tube. but,
When considering its heat exchange efficiency.

The thin film of the heated liquid flowing down along the outer wall of the heat exchanger tube is required to be uniform. However, in conventional vertical external thin film falling type heat exchangers, the thin film of the flowing liquid to be heated formed on the outer wall of the heat transfer tube is greatly affected by the depth of the heated liquid to be supplied, resulting in non-uniformity. It was believed that it would be extremely difficult to improve the uniformity.

Therefore, an object of the present invention is to provide a liquid disperser that makes the thin film flowing on the outer wall of a heat transfer tube uniform in a vertical thin film falling type heat exchanger.

To summarize the liquid disperser of the present invention, it is a liquid disperser disposed on the outer surface side of the heat transfer tube of a partition portion that partitions an internal chamber into upper and lower parts of a vertical thin film falling type heat exchanger having heat transfer tubes installed vertically. The liquid distributor includes a liquid volume control section formed along and near the outer circumferential surface of the heat exchanger tube and including all openings for controlling the amount of liquid flowing down the outer surface of the heat exchanger tube and the liquid depth at the upper part of the liquid distributor; a branching deflection chamber formed at the lower part of the liquid volume control section; and a dispersion shelf arranged opposite to the opening in order to uniformly disperse the liquid flowing down after the liquid quantity control section is fully valved into the branching deflection chamber. and a thin film liquid flow forming part formed by an opening that forms a thin film liquid flow along the outer surface of the heat transfer tube from the liquid which is uniformly dispersed into the flow deflection chamber by the dispersion shelf part.

Hereinafter, the liquid disperser of the present invention will be explained in more detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 shows a liquid disperser 10 according to an embodiment of the present invention together with a vertical thin film falling type heat exchanger 1. As shown in FIG.

This vertical thin film falling type heat exchanger 1 has a plurality of heat exchanger tubes 3 arranged vertically in a cylindrical body 2, and the upper and lower ends of the heat exchanger tubes 3 are an upper plate 4a and a lower part that partition the cylindrical body 2, respectively. Board 4
The mounting is fixed in a sealed manner to b. These heat transfer tubes 3
The respective ends of the upper plate 4a and the lower plate 4b hardly protrude from the surfaces of the upper plate 4a and the lower plate 4b, and the surfaces of the upper plate 4a and the lower plate 4b are substantially flat. An inlet portion 5 for supplying a heating source into the heat transfer tube 3 and an outlet portion 6 for discharging the heat source are formed at the upper and lower ends of the cylindrical body 2, respectively.

A plurality of liquid supply lowers are formed on the peripheral wall of the cylindrical body 2 slightly below the upper plate 4a, and one liquid drain port is formed on the peripheral wall of the cylindrical body 2 slightly above the lower plate 4b. 8 is formed. Furthermore, a weir plate 11 is arranged and fixed in the cylindrical body 2 below the liquid supply lower part so as to partition the internal chamber of the cylindrical body 2 into upper and lower parts. A distributor 10 is integrally formed.

In addition, in FIG.
This is a weir for regulating the waves of the heated liquid that is supplied upward.

As shown in FIGS. 2 to 5, the liquid distributor 10 is formed in the insertion hole 12 of the weir plate 11 through which the heat exchanger tube 3 is inserted. The cross section, which is enlarged in diameter at the middle part in the height direction, has a hollow shape,
Moreover, the liquid volume control section 13 is controlled by a plurality of protrusions 13 that protrude radially inward at predetermined intervals in the circumferential direction at the upper part of the inner surface. The thin film liquid flow forming portion 16 is formed by forming a plurality of dispersion shelf portions 17 which are protruding portions projecting radially inward at intervals.

The above-mentioned liquid amount control section 13 includes a trapezoidal notch 15 appearing between the above-described protrusions 14, and the notch 1
5 (functions as an opening for controlling the flow rate on the outer surface of the heat transfer tube and the depth of the liquid at the top of the liquid fraction).

On the other hand, in the thin film liquid flow forming section 16, as is clear from FIGS.
It is formed at a position opposite to the opening of No. 3, that is, the notch 15, and its cross-sectional shape and thickness are almost the same as that of the notch 15, only by reversing the direction of the trapezoid. There is. The notches 18 appearing between the dispersion shelves 17 function as openings for forming a thin film liquid flow.

The inner diameter enlarged portion of the insertion hole 12 between the liquid volume control section 13 and the thin film liquid flow forming section 16 is connected to the flow deflection chamber 19.
It acts as. Furthermore, the notch 15 of the liquid volume control section 13
The notch portion 18 of the thin film liquid flow forming portion 16 is formed with a depth such that its depth surface is continuous with the inner wall surface of the flow deflection chamber 19.

Therefore, in other words, as shown in FIG. 5, the insertion hole 1 has an inner diameter larger than the outer diameter of the heat exchanger tube 3.
A protrusion 14 and a dispersion shelf 17 are formed on the upper and lower inner surfaces of the inner surface 2 and radially inward at a predetermined interval in the circumferential direction, respectively. It is located at a position shifted in phase from that of the protrusion 14, and faces the trapezoidal notch 15 appearing between the protrusions 14, and is formed in a shape that substantially coincides with the notch 15, although the direction is opposite to that of the moon. It's been done.

Liquid dispersion D according to an embodiment of the present invention configured as described above
The function of IO will be explained.

For example, the liquid to be heated (hereinafter simply referred to as liquid) supplied from the liquid supply lower to the upper chamber of the weir plate 11 of the cylindrical body 2 passes through the weir 9 and is wave-formed, and the waves of each of the heat exchanger tubes 3 are adjusted. The liquid is supplied to the liquid disperser 10 while maintaining the liquid at an appropriate depth. Here, since the liquid is supplied from the periphery of the heat transfer tube group, the liquid on the weir plate 11 has a gradient. For example, if 1000 heat exchanger tubes 3 with a diameter of 254 are arranged in a square arrangement with a pitch of 32 threshold, the liquid supply amount per unit width of the heat exchanger tubes is 2700 φhr and the liquid depth is 100.
In the case of Chi, the liquid gradient is approximately 10 Chi. Therefore, the liquid depth must be determined based on the number of pipes and the amount of liquid supplied, taking into account the liquid gradient.

In the liquid disperser 10, the opening 15 of the liquid volume control unit 13 determines the amount of liquid flowing down, and the protrusion 14 serves as a support (a steady rest for the heat exchanger tube) that holds the heat exchanger tube 3 at the center of the liquid distributor 10.
It also acts as

Also, the depth from the heat exchanger tube at the opening 15 of the liquid volume control section 13, the gap between the inner wall and the heat exchanger tube 3 in the branch deflection chamber 19, and the depth from the heat exchanger tube at the opening 18 of the thin film liquid flow forming section 16. As is clear from the above-mentioned configuration, they are equal, and if their dimension is now t, this t varies from about 1.0 to 3.0 mm depending on the degree of contamination of the liquid on the outside of the tube and the degree of susceptibility to clogging.
determined within the range of In addition, the number and opening area of the openings 15 in the liquid volume control unit 13 are determined by the liquid volume and liquid depth, and in particular, the number is determined by the size of the heat transfer tube 3 and the openings 18 of the thin film liquid flow forming unit 16. It is determined by the flow rate of the liquid and the surface tension of the liquid. However, even in that case, it is preferable that the number of openings 15 be at least six or more. Note that since the number and area of the openings 18 of the thin film liquid flow forming section 16 correspond to the protrusions 14 of the liquid volume control section 13 as described above, the number and area of the openings 15 are determined. is inevitably determined by

That is, once the upper liquid depth of the liquid distributor 10 is determined, the dimensions and number of the openings 15 of the liquid volume control section 13 are determined, and the outflow velocity of the liquid spouted from the openings 15 is expressed as vo=coηF. . Here, VO is the liquid flow rate through the 15 openings,
g is the gravitational acceleration, h is the upper liquid depth of the liquid disperser 10, and Co is the outflow coefficient.

As shown in FIG. 6, the jet flowing out from the opening 15 into the dividing flow deflection chamber 19 collides with the dispersion shelf 17 of the thin film liquid flow forming section 16 and is deflected in two directions, thereby changing the movement of the fluid flow. The direction is partially deflected from the axial direction of the heat transfer tube to the horizontal direction. The jet thus deflected collides with the adjacent deflected jet, the horizontal component disappears, and the jet flows down through the opening 18. At this time, the velocity of the liquid flowing out from the opening 18 is expressed as follows. Here, vt is the liquid flow rate passing through the opening 18, A1 is the opening area s of the opening 15, A2 is the opening area of the opening 18, and K is a correction coefficient based on the size of the dispersion shelf 17.
．． A value greater than 0, Cm, is the composite runoff coefficient.

In order to divide and deflect the jet flow from the opening 15 of the liquid volume control section 13, the width and shape of the dispersion shelf 17 are determined according to the jet flow velocity from the opening 15, in other words, the upper liquid depth of the liquid distributor 10. Selected by.

However, it is desirable that the width of this distribution shelf 17 is greater than or equal to the opening width of the opening 15. Furthermore, the thickness of the protruding part 14 of the liquid volume control part 13 and the thickness of the dispersion shelf part 17 of the thin film liquid flow forming part 16 can be appropriately selected as long as they are such that they are likely to be damaged when the heat exchanger tube shakes. The length of the branch deflection chamber 19 may be such that the liquid flowing down from the opening 15 of the liquid amount control section 13 flows smoothly. In FIG. 7, the distributed shelf section 17
A modification of the surface shape is shown. The dispersion shelf 17 shown in FIG. 7 has a slightly concave surface 20.

- gaps M and N between the end surfaces of the protrusion 14 of the liquid volume control section 13 and the dispersion shelf section 17 of the thin film liquid flow forming section 16 and the heat transfer tube 3;
Since these protrusions and dispersion shelves have the function of holding the heat exchanger tube in the center of the insertion hole 12, it is better to be as small as possible, but from the viewpoint of thin film formation, it is recommended that the Desirably, in this case, a thin film can be formed even if one side is in contact with the outer wall of the heat exchanger tube.

In this way, the liquid from the opening 18 of the thin film liquid flow forming section 16 flows out in the form of a small rise, and the flowing liquid quickly spreads along the outer wall of the heat transfer tube 3 all around the tube due to its surface tension. Spread to form a uniform thin film flow.

Next, an example of the use of the heat exchanger will be explained.

An inclined vertical thin film falling type heat exchanger was used to recover the heat from the acetone release column. At that time, the released steam is highly corrosive because it contains chlorine ions (cz"'), and in the case of conventional external heating, due to the material as described above. However, this problem can be solved by flowing the discharged steam into the pipe and making it the heating side. For a heat exchanger tube with an outer diameter of 25.4wn, an inner diameter of 230mm, and a length of 6m, the opening 150 of the liquid volume control section 13 has a thickness of 3 x
4 x 2 mm (3 short sides, 4 ttrm long sides)
, a trapezoid with a height of 2), the number of openings 15 is 8, the thickness of the weir plate 11 is 20 mm, and the amount of liquid supplied per unit width of the heat exchanger tube is 600 to 27.
At 00h/mhr, the overall heat transfer coefficient is 11
00-1300 Kdz temperature was obtained.

In addition, in the example above, a heating source is passed inside the heat transfer tube and the liquid to be heated flows down outside the heat transfer tube. may be allowed to flow down.

As explained above, according to the liquid disperser of the present invention, the liquid depth above the weir plate and the amount of liquid flowing outside the heat transfer tube are controlled by the liquid amount control unit, and the uniform dispersion of the liquid is related to the liquid depth and the amount of liquid. Since the thin film liquid flow is directed directly to the thin film liquid flow forming section without any problems, a very uniform thin film liquid flow is formed on the outer wall of the heat transfer tube, which improves the heat exchange efficiency in the vertical thin film falling type heat exchanger. can.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a vertical external thin film falling type heat exchanger equipped with a liquid disperser according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the liquid disperser, and FIG. Fig. 2 is a top view of the liquid disperser showing the liquid volume control section of the disperser, Fig. 4 is a bottom view of the liquid disperser in Fig. Figure 5 is a 1° perspective view with a part of the liquid disperser cut away, Figure 6 is an explanatory diagram showing the state of liquid flowing down in the liquid disperser, and Figure 7 is a diagram showing the flow of liquid in another modification of the liquid disperser. FIG. ■... Vertical thin film falling type heat exchanger, 3... Heat exchanger tube, 1
0...Liquid disperser, 11...Weir plate, 12...Insertion hole, 13...Liquid amount control section, 14...Protrusion part, 15...
・Notch part or opening part, 16... Thin film liquid flow forming part, 1
7...Dispersion shelf part, 18...Notch part or opening part, 1
9...Diversion deflection chamber.

Claims (1)

[Claims] (1) A liquid disperser disposed on the outer surface side of the heat exchanger tube of a partition portion that partitions an internal chamber into upper and lower parts of a vertical thin film falling type heat exchanger having heat exchanger tubes installed vertically, a liquid volume control part formed near the outer circumferential surface and having an opening for controlling the liquid volume flowing down on the outer surface of the heat transfer tube and the liquid depth at the upper part of the liquid distributor; and a flow dividing deflection formed at the lower part of the liquid volume control part. a dispersion shelf disposed opposite to the opening in order to uniformly disperse the liquid flowing down through the liquid volume control section into the diversion deflection chamber; and a thin film liquid flow forming section having an opening that forms a uniformly dispersed liquid into a thin film liquid flow along the outer surface of the heat transfer tube. (2. In the liquid disperser according to claim 1, the liquid volume control section moves radially inward at a predetermined interval in the circumferential direction at the upper inner surface of the insertion hole through which the heat transfer tube is inserted. The protrusion has an overhanging protrusion, and the protrusion forms a notch serving as the opening for controlling the downstream flow rate on the outer surface of the heat exchanger tube and the liquid depth of the liquid dispersion type upper liquid, and the dispersion of the thin film liquid flow forming section is provided. A protruding part having a shelf protruding radially inward at a predetermined interval in the circumferential direction at a lower part of the inner surface of the insertion hole and located opposite to the opening of the liquid volume control part, the protruding part extending between the openings of the liquid volume control part. A notch is formed as the opening for forming a thin film liquid flow, and the flow deflection chamber is formed by a space between the liquid volume control part and the thin film liquid flow forming part on the inner surface of the insertion hole. A liquid disperser characterized by: