JPH0443749Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a vertical multi-tubular heat exchanger, and more specifically, to a heat exchanger in which a bundle of tubes inside a cylinder can be easily exposed. It is related to. This is used in the field of cleaning a large number of heat transfer tubes that make up a tube bundle after condensing steam generated in a distillation column.

[Conventional technology]

Vertical condensers, which are connected to distillation towers installed in chemical factories and steel factories to process generated steam, are ideal for fluid flow and heat transfer performance, and also have a small footprint. A shell-and-tube heat exchanger is used. Some of these are larger, with a distance of, for example, 6 meters between the upper floating head and the lower partition.

In such a heat exchanger, for example, steam at about 50°C flows through multiple heat transfer tubes as the fluid to be cooled.
Some types allow water at a temperature of about 20 to 30°C to flow through the cylinder to cool the heat transfer tubes and condense the steam. Normally, the amount of cooling water used is enormous, so cheap and abundant seawater is used to reduce operating costs. on the other hand,
Seawater is corrosive to metals, and also contains dust and microorganisms, which pass through the strainer and adhere to the surface of the tube bundle together with salt.
Heat transfer performance is impaired. Therefore, it is necessary to clean the outer surface of the heat exchanger tubes about once every six months.

For example, in a fixed tube sheet type heat exchanger 1 as shown in FIG. 5, prior to cleaning, a tower is assembled around the heat exchanger 1, and covers 2 of a plurality of cleaning windows are removed.
Workers clean the tube bundle inside the barrel with a high-pressure water jet through the window. As a result, it is not easy to remove deposits in deep locations other than the heat exchanger tubes near the window, and the heat transfer performance of each heat exchanger tube cannot be sufficiently restored.
There is a problem in that the condensing capacity of the heat exchanger 1 is reduced.

[The problem that the idea aims to solve]

By the way, the floating head type heat exchanger 3 shown in FIG.
Now, after removing the gland section 4 and the flange sections 5 and 6 and removing the upper connecting pipe 7, the section forming the tube bundle 9 shown by hatching can be pulled upward using a crane or the like using the lifting section 8. be exposed. The weight of the extracted part can be as much as 20 tons, for example, and it requires the equipment of a large crane, which increases factory construction and maintenance costs.
The drawback is that it takes time and effort to pull out the tube bundle and restore the pipes necessary for cleaning.

For salvage by such a crane,
Various preparations are required prior to cleaning work. For example, as described in Japanese Unexamined Patent Publication No. 49-61746, consideration is given to avoiding the complexity of such operations. that time,
As in the above-described example, it is necessary to expose the tube bundle from the outer shell for maintenance and inspection, and techniques for such procedures are well known.
That is, the conventional concept is to fix the outer shell to the floor or the like and then remove the tube bundle from the outer shell. Various efforts have been made to simplify such removal work, but this results in a more complex structure.

Additionally, as mentioned above, when removing the tube bundle from the outer shell while keeping the outer shell fixed, the removed tube bundle must be moved to another location in order to inspect or replace the heat transfer tubes. Must be. Incidentally, in the heat exchanger having the above configuration, the heated secondary fluid is collected in the upper part of the tube plate and is sent out from the secondary fluid outlet. When the secondary fluid is a mixture of gas and liquid, the secondary fluid is discharged as a mixture of gas and liquid, which may result in an undesirable heat exchanger. Therefore, there is a problem in that a gas-liquid separator must be installed downstream of the heat exchanger, which increases the manufacturing cost of the device.

The present invention was developed in view of the above-mentioned points, and its purpose is to maintain the position of the tube bundle and remove only the tube body when exposing the inner tube bundle from the cylinder body. Therefore, maintenance work can be performed without moving the tube bundle to another location, that is, the exposure of the tube bundle can be achieved with a minimum amount of movement, and the movement of the cylinder body for that purpose can be facilitated. , it is possible to avoid the time and effort required for maintenance and inspection of the heat exchanger, and furthermore, when performing gas-liquid separation based on the difference in specific gravity in the lower partition chamber of the heat exchanger, it is possible to avoid the need for a gas-liquid separator that was previously required. It is an object of the present invention to provide a vertical multi-tube heat exchanger that eliminates the need for equipment production costs and maintenance costs.

By the way, in this invention, we focused on the fact that when the pressure on the cylinder side is low, the weight of the cylinder is lighter than the weight of the tube bundle, and based on the knowledge that maintenance costs can be significantly reduced by removing the lighter cylinder. The idea is to break away from the preconceived notion that the cylindrical body is something that should be fixed.

[Means to solve the problem]

In the present invention, the upper part of a tube bundle consisting of a number of heat transfer tubes extending vertically and through which the fluid to be cooled flows is attached to the upper tube sheet, while the lower part of the tube bundle is attached to the lower tube sheet, and the lower part of the tube bundle is attached to the lower tube sheet. An upper floating head having a space for allowing the fluid to be cooled to flow through each heat transfer tube is integrated at the top, and a lower partition chamber having a space for accommodating condensate is integrated below the lower tube plate. The present invention is applied to a vertical multitubular heat exchanger in which a cylindrical body forming a peripheral wall for circulating cooling water around a tube bundle is disposed between an upper floating head and a lower partition.

Its characteristics are as shown in Figure 1.
The cylinder body 12 is mounted on the lower tube plate 14,
The inner diameter of the lower end of the barrel 12 is smaller than the diameter of the lower tube plate 14. The inner diameter of the barrel 12 is larger than the outer diameter of the upper floating head 13, and the barrel 12 is removably fitted onto the tube bundle 17 upwards. The lower partition chamber 11 is provided with an outlet 11a in its lower part for discharging the condensed liquid, and an outlet 11b in its upper part for taking out the steam separated from the condensed liquid due to the difference in specific gravity. Then, the upper floating head 13, the tube bundle 17, and the lower partition chamber 1
By lifting the cylinder body 12 and moving it up to at least the upper floating head 13 while the tube bundle 17 is integrally fixed with the tube bundle 17, the tube bundle 17 can be exposed outside the cylinder body 12.

〔Example〕

The present invention will be described in detail below based on examples thereof.

The condenser, which is an example of the vertical multi-tubular heat exchanger 10 shown in FIG.
It consists of an upper floating head 13 connected to. Below the condenser 10, a lower partition 11 is provided which is integrated with a lower tube plate 14 and is fixed to the floor of the factory. In the lower partition chamber 11, a space 11A for accommodating the condensate is formed, and a discharge port 11a for the condensate is opened at the lower part thereof, and an outlet 11b for releasing steam is provided at the upper part. There is. The lower ends of a plurality of heat exchanger tubes 15 are fixed to the lower tube plate 14, and the steam is condensed while flowing through the plurality of heat exchanger tubes 15 constituting the tube bundle 17.

On the edge of the lower tube plate 14, the barrel 12 is removably mounted upwards. Therefore, the inner diameter of the lower end of the barrel 12 is smaller than the diameter of the lower tube plate 14. And this barrel 1
The inner diameter of the upper floating head 13 is larger than the outer diameter of the upper floating head 13, and the cylinder body 12 is removable upward.
It is fitted onto the outside so as to cover the tube bundle 17.

The cylinder body 12 has a space 12A formed therein.
A cylinder-side inlet nozzle 12a that introduces seawater, which is cooling water, and a cylinder-side outlet nozzle 12b that discharges seawater.
is installed. Further, the upper floating head 13 integrated with the upper tube plate 16 is formed with a space 13A necessary for allowing steam from the distillation tower, which is a fluid to be cooled, to flow through the heat transfer tubes 15. Its upper tube plate 1
The upper ends of heat transfer tubes 15 are fixed to 6, and the upper floating head 13 and lower partition chamber 11 are integrated via a tube bundle 17. Furthermore, in order to enhance the heat transfer effect by alternately reversing the flow of cooling water in the direction of the arrow 18 in the above-mentioned space 12A, a plurality of buttful plates 19 are arranged vertically so as to hold a large number of heat transfer tubes 15. are placed at approximately regular intervals. Note that these buff-full plates 19 are fixed by fixing rods 20 fixed to the upper tube plate 16.

The cylinder body 12 described above is provided with a lifting portion 21 for lifting the cylinder body 12 upward when it is removed from the condenser 10, and a drain hole 22 for discharging seawater. In addition, the upper floating head 1
3 is removably connected to the steam inlet pipe 23 as described above, and the inlet pipe 23 is attached to a factory steel frame or the like (not shown) via a support member. Incidentally, the cooling water level in the cylinder body 12 is designed to be located slightly below the upper tube plate 16. Therefore, it is possible to prevent water pressure from acting on the cylinder body 12, and the plate thickness of the cylinder body 12 can be reduced and the weight can be reduced, and its removal becomes easy, which is extremely convenient.

Note that a gap 12c shown in FIG. 2 is created between the upper tube plate 16 and the inner surface of the upper end of the barrel 12, so if a removable cover 24 as shown in the figure is attached to the upper floating head 13, dust and sand can be removed. can be prevented from entering the barrel 12. However, the present invention is not limited to this.
5 as shown in FIG. 3, it is also possible to use cooling water having an internal pressure of, for example, 10 kg/cm ² .

According to the vertical multitubular heat exchanger 10 configured as described above, it can be easily cleaned as described below, and the heat exchange performance can be maintained at a high level.

Prior to cleaning, the steam source valve (not shown) of the distillation tower is closed to cut off the supply of steam to the heat exchanger. connection pipe 23, upper floating head 13, heat exchanger tube 15,
When the residual steam in the lower partition chamber 11 condenses, the seawater cylinder side inlet nozzle 12a is closed and the drain hole 22 is closed.
Drain the cooling water from the Then, remove the pipes connected to the barrel-side inlet nozzle 12a and the barrel-side outlet nozzle 12b, and the coupling between the connecting pipe 23 and the upper floating head 13, and remove the elbow pipes shown by broken lines in the vicinity of the pipes connected to the barrel-side inlet nozzle 12a and the barrel-side outlet nozzle 12b. Remove the members that obstruct the removal of 12.

The weight of the connecting pipe 23 is placed on the factory steel frame, while the integrated upper floating head 13 and tube bundle 17
It is received in the lower partition 11. After removing the connection between the lower partition 11 and the barrel 12, the worker lifts the barrel 12 via the lifting section 21 using a factory crane (not shown) and moves it to at least the upper floating head 13, as shown in FIG. Hold it in place or remove it. As the cylinder body 12 rises, the tube bundle 1
7 is exposed. Therefore, the operator uses high-pressure cleaning water to clean the heat transfer tubes 15, the buttful plate 19,
It is possible to clean limescale and the like that have adhered to the surface of the fixing rod 20 or the like, or to fill in the gaps therebetween.

In the example shown in FIG. 2, the cover 24 may be cleaned before lifting the barrel 12, and after the gasket 25 is removed in the example shown in FIG. 3, the cleaning may be performed in the manner described above.

By the way, some of the cooled steam is condensed and liquefied, and some of it is guided into the lower compartment 11 as a vapor, and the liquid condensed due to the difference in specific gravity is at the bottom of the lower compartment, and the steam is placed above the lower compartment. are collected in. The condensed liquid is discharged from the outlet 11 installed at the bottom of the lower partition 11.
Steam separated from the condensate from the condensate due to the difference in specific gravity is sent out from the outlet 11b in the upper part. In general, gas-liquid mixtures are rarely extracted, and only gas or liquid is normally required, and a gas-liquid separator may be installed downstream of the heat exchanger. many. However, in the present invention, gas-liquid separation is performed in the lower partition chamber of the heat exchanger based on the difference in specific gravity, so the gas-liquid separator that was required in the past is not required, and the manufacturing and maintenance costs for the equipment are reduced. This has the advantage of not being necessary.

By the way, when the pressure on the cylinder side is low, the weight of the cylinder is extremely lighter than the weight of the tube bundle, but this invention focuses on this and makes it possible to significantly reduce maintenance costs by removing the lighter cylinder. In other words, the idea is to break through preconceived notions by lifting the barrel, which was conventionally thought to be fixed. In other words, if the tube bundle weight is approximately 14 tons, the barrel weight is approximately 3.5 tons.
About a ton. It is very convenient to move the lighter barrel because it significantly reduces maintenance costs for lifting and moving. Furthermore, in cases where inspections and cleaning are frequently performed, such as in the case of condensers using seawater, which are carried out once every six months, it is extremely important to reduce maintenance costs.

[Effect of idea]

As can be seen from the detailed description of the embodiments above, the present invention is such that the barrel is removably provided above, the tube bundle is integrated with the upper floating head and the lower partition, and the inner diameter of the barrel is lower than the upper floating head. Since it is made larger, the barrel can be easily lifted upwards. As a result, the tube bundle can be easily exposed in its entirety, and the labor involved in dismantling and assembling for cleaning is significantly reduced, and the working time is shortened, improving efficiency. In addition, since the tube bundle is maintained in a state where it is easy to clean, cleaning work becomes easy and sufficient cleaning is performed, and heat exchange performance can be maintained after restoration. Furthermore, since the cylinder body of the heat exchanger is lighter than the tube bundle, only a small crane device is required for preparation for cleaning, and the construction cost of the plant can be reduced. In addition, the condensate is discharged from the outlet located at the bottom of the lower partition.
Steam separated from the condensate due to the difference in specific gravity can be taken out from the outlet located in the lower part, and the installation of an accompanying gas-liquid separator for this purpose can be omitted.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the vertical multi-tubular heat exchanger of the present invention, Fig. 2 is a sectional view of a modified example of the upper floating head, and Fig. 3 is a sectional view of another example of the same part. Figure 4 is a sectional view showing the raised state of the barrel, Figure 5 is an external view of a conventional fixed tube sheet type vertical multi-tube heat exchanger, and Figure 6 is a floating head type vertical multi-tube heat exchanger. It is a sectional view of a heat exchanger. 10... Vertical multi-tubular heat exchanger, 11... Lower partition, 11A... Space, 11a... Discharge port, 11
b...Outlet port, 12...Cylinder body, 13...Upper floating head, 13A...Space, 14...Lower tube plate, 15...
...Heat transfer tube, 16... Upper tube sheet, 17... Tube bundle.

Claims (1)

[Claims for Utility Model Registration] The upper part of a tube bundle consisting of a number of heat transfer tubes extending vertically and through which the fluid to be cooled flows is attached to the upper tube plate, while the lower part of the tube bundle is attached to the lower tube plate, and the lower part of the tube bundle is attached to the lower tube plate. An upper floating head having a space for allowing the fluid to be cooled to flow through each of the heat transfer tubes is integrated above the upper tube plate, and a lower partition having a space for accommodating condensate below the lower tube plate. The rooms are integrated,
In a vertical multi-tubular heat exchanger, a cylinder body forming a peripheral wall for circulating cooling water around the tube bundle is disposed between the upper floating head and a lower partition, In order to be able to ride on the tube plate, the inner diameter of the lower end of the barrel is smaller than the diameter of the lower tube plate, the inner diameter of the barrel is larger than the outer diameter of the upper floating head, and the barrel is The lower partition is removably fitted onto the tube bundle, and the lower partition has a discharge port for discharging the condensate in the lower part thereof, and a discharge port in the upper part for taking out the steam separated from the condensate due to the difference in specific gravity. by lifting the cylinder and moving it to at least the upper floating head with the upper floating head, the tube bundle, and the lower partition chamber fixed together,
A vertical multi-tubular heat exchanger, characterized in that the tube bundle can be exposed outside the cylinder body.