JPH11304379A - Glass lining type multipipe exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the glass lining of a heat transfer tube from being peeled without decreasing treatment capacity by forming a part including the inner diameter side part of an end part where a heat transfer pipe is welded and a welding part in a sculptured surface shape and setting the pitch between the centers of adjacent heat transfer pipes to a specific range. SOLUTION: Both the ends of a number of heat transfer pipes 11 are mounted to a metal pipe plate 10 with a constant interval, and the part of the metal pipe plate 10 where end parts 16 are mounted and a welding part 15 are formed in an R part in a sculptured surface shape where rounding is executed with a constant radius of curvature. Considering the minimum value that the radius of curvature of the R part should take and the fact that it is desirable to provide a part with a constant dimension as a flat end part 25, the lower and upper limits of a pitch (p) are (d1+8) and (d1+25) mm, respectively, where d1 and p indicates the inner diameter and the pitch of the heat transfer pipe, thus preventing a glass lining from being peeled off and preventing the throughput as a heat exchanger from decreasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass-lined heat exchanger in which heat-transfer tubes whose inner surfaces are lined with glass are arranged at regular intervals, wherein the arrangement of the heat-transfer tubes is optimized. About things.

[0002]

2. Description of the Related Art In a glass-lined heat exchanger, a large number of heat transfer tubes are integrally mounted on a metal tube plate at both ends thereof at regular intervals in an inner shell and a vitreous lining head which cover the outside. The structure is made.

In this heat exchanger made of glass lining, since the heat exchange fluid supplied to the inside of the heat exchange tube includes a corrosive fluid, the inner surface of the heat exchange tube that comes into contact with the heat exchange fluid and the metal The entire outer surface of the tubesheet is glass-lined to prevent corrosion.
The glass-lined heat transfer tube is attached to the metal tube plate by welding the end of the heat transfer tube to the metal tube plate.

In order to facilitate the application of the glass lining to this portion and to prevent the glass lining from being peeled off after the application, a corner portion including the inner diameter side portion of the end portion of the welded heat transfer tube and the welded portion. Means that an R portion having a curved surface with a constant radius of curvature is formed.

[0005]

Here, from the viewpoint of preventing the glass lining from peeling, it is desirable to form the radius of curvature of the R portion larger, but in order to increase the radius of curvature of the R portion, The spacing between adjacent heat transfer tubes must be larger.

In order to perform heat exchange of a predetermined amount of heat exchange fluid at a required heat exchange rate, the planned number of heat transfer tubes of the heat exchanger cannot be reduced.

Accordingly, in order to prevent the glass lining from peeling, the radius of curvature of the R portion must be large, and the heat exchanger itself must be enlarged in order to prevent a decrease in the processing capacity of the heat exchanger.

[0008] However, increasing the size of the heat exchanger increases the cost thereof, and disadvantageously increases the plant construction cost due to the increased installation area.

Accordingly, an object of the present invention is to provide a heat exchanger made of glass lining which can prevent the separation of the glass lining of the heat transfer tube and prevent the heat exchanger from being enlarged without reducing the processing capacity. And

[0010]

In order to solve the above-mentioned problems, a glass-lined heat exchanger of the present invention has a large number of heat transfer tubes arranged at regular intervals, and the ends thereof are welded to a metal tube plate. A portion including an inner diameter side portion of the end to be welded of the heat transfer tube and a welded portion are formed in a curved R portion, and a pitch between centers of adjacent heat transfer tubes is
It is characterized by being in a range of not less than a value obtained by adding 8 mm to the inner diameter of the heat transfer tube and not more than a value obtained by adding 25 mm to the inner diameter of the heat transfer tube (claim 1).

When the pitch at which the heat transfer tubes are arranged is within the above range, a fixed number or more of the heat transfer tubes are attached to a metal tube plate having a limited size, thereby preventing a reduction in the processing capacity of the heat exchanger while preventing the heat exchanger from deteriorating. It is also possible to prevent peeling of the glass lining in the part.

That is, the maximum value of the pitch between the centers of the heat transfer tubes is set to a value obtained by adding 25 mm to the inner diameter of the heat transfer tubes. The heat transfer tubes can be attached to a metal tube plate of a certain size at appropriate intervals. On the other hand, since the minimum value of the pitch between the centers of the heat transfer tubes is a value obtained by adding 8 mm to the inner diameter of the heat transfer tubes, the radius of curvature of the size required to prevent the glass lining from peeling off at the R portion. Can be formed.

Thus, it is possible to prevent a decrease in the processing capacity of the heat exchanger without increasing the size of the heat exchanger.
The peeling of the glass lining can also be prevented.

It is preferable that the radius of curvature of the R portion is 4 mm or more (claim 2) in order to prevent the glass lining from peeling off at the R portion. That is, due to the property that a compressive strain is left in the glass lining layer after the lining, a synthetic force acting outward in the thickness direction acts on the R portion glass, and if the radius of curvature is not sufficiently taken, R
The glass lining surface of the part may crack, peel off or break. Further, when the portion between the R portions of the adjacent heat transfer tubes of the metal tube plate is formed as a flat portion having a flat shape (claim 3), the R portion and the glass lining in the flat portion can be hardly peeled off. preferable. That is, when the flat portion is not formed, the R portions mutually influence the internal stress of each other, so that the glass lining between the R portions is easily peeled off. However, when the flat portion is formed, the influence of the stress between the R portions is reduced by the flat portion, so that peeling of the glass lining between the R portions can be suppressed.

Here, the dimension of the flat portion is set to 17 mm or less (claim 3). Accordingly, by providing a flat portion having a length equal to or more than a certain value that can remove the influence of the stress between the R portions within a range where the pitch does not become more than a certain value,
Separation of the glass lining in the R portion and the flat portion can be made harder to occur.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a side view including a partial cross section of a glass-lined heat exchanger 1 according to an embodiment of the present invention.

A heat exchanger 1 made of glass lining is provided with a shell 2 on its outside and a vitreous lining head 3 on both sides thereof.
a, 3b.

A nozzle 5 provided in the shell 2 is an inlet for a heat medium or a refrigerant communicating with the inside of the shell 2.
Is an outlet of the heat medium or the refrigerant.

Inside the heat exchanger 1, II-
As shown also in FIG.
A large number of heat transfer tubes 11 arranged along the longitudinal direction are attached at both ends to the metal tube plate 10 at regular intervals.

The inner surface of the heat transfer tube 11 has a glass lining 2
1 is formed. The glass lining 21 can be formed by lining a glass tube on the inner surface of the heat transfer tube 11 or by a glaze method.

The metal tube sheet 10 and the vitreous lining heads 3a, 3b are hermetically connected by these flange portions.

The fluid to be heat-exchanged by the heat exchanger 1 is guided into the interior of the heat exchanger 1 by an intake port 7 provided in one of the vitreous lining heads 3a, and passes through the heat transfer tube 11. It is discharged from an outlet 8 provided in the other vitreous lining head 3b. In this way, the heat exchange fluid guided into the heat exchanger 1 is heated or cooled by heat exchange with the heat medium or the refrigerant via the heat transfer tube 11.

Next, the portion of the metal tube plate 10 to which the heat transfer tubes 11 are attached will be described with reference to FIG.

FIG. 3 is a partial sectional view showing, on an enlarged scale, the periphery of the end of the heat transfer tube 11 attached to the metal tube plate 10.

The outer diameter of the metal tube sheet 10 is selected according to the shell 2, and the shell 2 is made of a carbon steel tube of 200A or more.

As the heat transfer tube 11, a carbon steel tube having a nominal diameter of 25A and a schedule 40 defined in JIS G 3454 is used. The inner diameter d1 is 26.2 mm, the wall thickness t is 3.4 mm, and the outer diameter is 3.4 mm. d2 is formed to be 34 mm.

A glass lining 22 is formed on the outer surface of the metal tube sheet 10. Then, after the heat transfer tube 11 having the inner surface provided with the glass lining 21 is welded to the metal tube sheet 10, the vicinity including the welded portion is again subjected to the glass lining.

The glass lining of the portion extending from the inner diameter side portion of the welded end portion 16 of the heat transfer tube 11 to the outer surface of the metal tube sheet 10 can be applied by a glaze method.

In this manner, a continuous glass lining covering from the inner surface of the heat transfer tube 11 to the outer surface of the metal tube plate 10 can be formed, so that the heat exchange fluid in contact with these portions becomes corrosive fluid. However, the heat exchanger 1 does not suffer from corrosion.

The heat transfer tubes 11 are attached to the metal tube plate 10 by welding the end portions 16 of the heat transfer tubes 11 to the metal tube plate 10.

The end portion 16, the portion of the metal tube sheet 10 to which the end portion 16 is attached, and the welded portions 15 are rounded with a constant radius of curvature as shown in FIG. It is formed in a curved R-shaped portion.

This R portion can be formed by welding the end portion 16 to the metal tube sheet 10 and then chamfering the welded portion with a grinder or the like.

When the radius of curvature of the R portion is increased, the glass lining can be easily applied to this portion.
Even if the R portion is exposed to a high temperature, the thermal stress acting on the glass lining in such a portion can be reduced, and peeling of the glass lining can be prevented.

The radius of curvature of the R portion is at least 4 mm
Desirably, the thickness is less than 4 mm, and the glass lining is easily peeled off at the R portion.

When the surface of the R portion is finished smoothly,
The construction of the glass lining can be made easier, and the quality of the glass lining can be improved.

For the heat exchanger 1 shown here, R
The portion has a radius of curvature of 5 mm.

Further, in the heat exchanger 1, a flat portion 25 having a flat shape is formed on the outer surface of the metal tube plate 10 between the R portions of the adjacent heat transfer tubes 11, 11. ing.

A flat portion 2 is formed on the outer surface of the metal tube sheet 10.
By providing 5, the glass lining in the flat portion 25 can be hardly peeled off.

That is, when the flat portion 25 is not formed, when the R portion is exposed to a high temperature, the adjacent heat transfer tubes 11, 1
Since the two R portions between 1 exert the influence of the internal stress on each other, the glass lining between the R portions is easily peeled off. However, by forming the flat portion 25, the influence of stress between the R portions can be reduced by the flat portion 25, and peeling of the glass lining between the R portions can be suppressed. When the flat portion 25 having a length equal to or more than a certain value is provided, the influence of the stress between the R portions can be removed, so that the glass lining in the flat portion 25 is less likely to be peeled off.

In the heat exchanger 1, the flat portion 25
Is set to 6.8 mm.

In the heat exchanger 1, the heat transfer tubes 11 are arranged on the metal tube plate 10 so that the pitch p, which is the dimension between the centers of the adjacent heat transfer tubes 11, is 43 mm.

When the size of the pitch p is increased, the number of heat transfer tubes that can be arranged on the metal tube plate of a limited size is reduced, and the heat exchanger 1 is capable of exchanging heat for a certain period of time. The amount of fluid is reduced and the heat exchanger throughput is reduced. Alternatively, in order not to reduce the processing capacity, it is necessary to prevent the number of heat transfer tubes to be attached from being reduced by enlarging the body shell and the metal tube plate itself.

Increasing the size of the shell shell and the metal tube sheet increases the number of heat exchangers, which leads to disadvantages such as an increase in the installation area and an increase in plant construction costs.

On the other hand, if the pitch p is suppressed to a certain value or less, it becomes impossible to secure a required curvature for the R portion, so that it is difficult to apply a glass lining to the R portion or to form the glass lining once. There is a possibility that the glass lining of the R portion may be peeled off.

Therefore, considering the minimum value of the radius of curvature of the R portion and the fact that it is preferable to provide a portion having a certain dimension as the flat portion 25, the relationship between the inner diameter d1 of the heat transfer tube and the pitch p is The lower limit of p is (d1 + 8) mm, and the upper limit of pitch p is (d1 + 25) mm.

The dimension of the flat portion 25 needs to be 17 mm or less in relation to the range of the pitch p.

Further, by setting the pitch p in the above range, a heat transfer tube satisfying a generally used JIS schedule can be used as the heat transfer tube 11, and the properties, manufacture and economics of the heat exchanger can be improved. In view of the above, it is preferable to use a steel pipe of 15A to 40A.

In FIG. 2, the heat transfer tubes 11 are arranged such that all the pitches p between the centers of the heat transfer tubes 11 are equal.
Has been described, but the pitch p may be different for each adjacent heat transfer tube if the pitch p is within the above range.

The arrangement of the heat transfer tubes with respect to the metal tube plate is as follows.
A staggered arrangement can also be used.

If the arrangement of the heat transfer tubes is arranged in a staggered arrangement, more heat transfer tubes can be arranged on a metal tube plate of the same size, so that the processing capacity of the heat exchanger can be further increased.

In this embodiment, an example has been described in which the inner diameter d1 is formed to be 26.2 mm as the heat transfer tube 11. However, the relationship between the range of the pitch p and the inner diameter d1 of the heat transfer tube is as follows. The same holds for the case where the inner diameter d1 of the heat transfer tube is different.

[0053]

As described above, the first aspect of the present invention has the effect of preventing the glass lining from peeling off and not reducing the processing capacity of the heat exchanger.

The inventions according to the second and third aspects have the effect that the peeling of the glass lining can be prevented.

[Brief description of the drawings]

FIG. 1 is a view showing a heat exchanger made of glass lining.

FIG. 2 is a view taken along line II-II.

FIG. 3 is an enlarged sectional view of the vicinity of an end of a heat transfer tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat exchanger 2 ... Body shell 3a ... Vitreous lining head 3b ... Vitreous lining head 5 ... Nozzle 6 ... Nozzle 7 ... Inlet 8 ... Outlet 10 ・ ・ ・ Metal tube plate 11 ・ ・ ・ Heat transfer tube 15 ・ ・ ・ Welded part 16 ・ ・ ・ End (of heat transfer tube) 21 ・ ・ ・ Glass lining 22 ・ ・ ・ Glass lining 25 ・ ・ ・ Flat portion

Claims (3)

[Claims] 1. A number of heat transfer tubes are arranged at regular intervals,
A glass-lined heat exchanger having its ends welded to a metal tube sheet, wherein a portion including an inner diameter side portion and a welded portion of the welded end of the heat transfer tube has a curved surface. The pitch between the centers of the adjacent heat transfer tubes is equal to or more than the value obtained by adding 8 mm to the inner diameter of the heat transfer tubes and is equal to or less than the value obtained by adding 25 mm to the inner diameter of the heat transfer tubes. A multi-tube heat exchanger made of glass lining, characterized in that: 2. The glass-lined heat exchanger according to claim 1, wherein the radius of curvature of the R portion is 4 mm or more. 3. The heat transfer tube according to claim 1, wherein said heat transfer tube is adjacent to said metal tube plate.
3. The glass-lined heat exchanger according to claim 1, wherein a portion between the portions is formed as a flat portion having a flat shape, and the dimension of the flat portion is 17 mm or less. 4.