JPS59155690A - Preheating heat-insulating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Control Field of the Invention] The present invention relates to a preheating and warming device suitable for preheating and keeping warm equipment and piping using a liquid metal sodium gold heat medium.

[Prior art]

2. Description of the Related Art Preheating and insulating devices for equipment and piping that use liquid metal sodium as a heat medium, such as fast breeder reactors, have conventionally had the structure shown in FIG. 1 or 2.

In FIG. 1, a pipe 10, which is an object to be heated, has a structure in which a plurality of pipes are connected at a welded portion 12. Since it is necessary to periodically inspect the welded portion 12 for defects such as scratches, a first heat insulating material 14 provided around the welded portion 12 is removable. On both sides of the first heat insulating material 14, second heat insulating materials 16 and 18 are combined with stepped portions to increase the heat insulating effect.
is arranged and covers the piping 10. Heaters 20, 22.2 are installed on the inner peripheral surfaces of the first heat insulating material 14 and the second heat insulating material 16.18 along the longitudinal direction of the pipe 10, respectively.
4 is a provision. In a preheating and heat retaining device having such a structure, the length of the piping that does not face the heater is 1. is small, and the pipe 10 can be preheated relatively uniformly. However, when inspecting the welded part 12, the first. Since the first heat insulating material 14 has the heater 20, there is a drawback that the work of taking out the first heat insulating material 14 is complicated.

Therefore, as shown in FIG. 2, a preheating and heat-retaining device having a structure in which the first heat-insulating material 14 is not provided with a heater has been considered. In this preheating and heat retention device, the first anchor material 14
Since no heater is provided in the first heat insulating material 14, the work of removing and attaching the first heat insulating material 14 can be completely simplified. However, there is a drawback that the length to of the piping that does not face the heater is not large, and the piping 10 cannot be uniformly preheated.

However, in the preheating device shown in Figs. 1 and 2, each heater attached to the heat insulating material has a mounting section that penetrates the heat insulating material in order to eliminate thermal distortion. The size of the heater itself is so large that it is inserted into a hole that is much larger. For this reason, this installation has the disadvantage that heat escapes from the part to the outside, reducing the preheating and heat retention effect of the plumber.

[Purpose of the invention]

The present invention has been made in order to eliminate the drawbacks of the prior art, and is a preheating/warming method that can reduce the difference in preheating temperature of a heated object and make it easier to inspect the inspection part of the heated object. The goal is to provide equipment.

[Summary of the invention]

In the present invention, the heater is formed in a substantially U-shape along the axial direction of the heated object, and the tip part is shaped along the circumferential direction of the heated object, and the heater is attached to the side of the first heat insulating material. The above object is achieved by attaching the heater to the disposed second heat insulating material such that the tip of the heater faces the inspection section of the heated object.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the preheating and warming device according to the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals are given to the parts corresponding to the parts explained in the prior art, and the explanation thereof will be omitted.

FIG. 3 is a longitudinal cross-sectional view of an embodiment of the preheating and heat-retaining device according to the present invention. In FIG. 3, around the pipe 10 there is an inner pipe 2
6 is arranged, and the spacer 28 connects the pipe 10 and the inner pipe 26.
A certain distance can be maintained between the two. The space defined by the inner tube 26 and the outer sheath 30 is filled with the first heat insulating material 14 and the second heat insulating material 16,18.

Preheaters 32 and 34 are fixed to the second heat insulators 16 and 18, respectively. These preheating heaters 32.34
consists of a mounting section 36.38 that penetrates the exterior, the second heat insulating material, and the circular pipe, and a heating section 40.42 that runs along the pipe 10. It is formed into a substantially U-shape along the inner pipe 26 via a fitting 43, and the tip portion is completely arcuate along the circumferential direction of the pipe 10, as shown in FIG.

The first heat insulating material 14 and the second heat insulating material 16°18 are connected by bands 44, 46 shown in FIG. .15 are interconnected by bands 48.50 to form a cylindrical overall shape. Furthermore, the preheaters 32 and 34 are arranged such that the arcuate tips along the circumferential direction of the pipe 10 face the welded portion 12 of the pipe 10 that needs to be inspected. And these preheat bees. Distance between the tips of 32.34 pm 12
As shown in Fig. 6, the first heat insulating material 14 is completely removed,
When the inspection device 50 is attached to the piping 10, the inspection device 5
It has a size that allows the sensor section 52 of 0 to pass through.

By configuring as described above, the first heat insulating material 14 can be easily removed and installed, and the welded portion 1 of the pipe 1.0 can be easily removed.
Test 2 can be easily performed. Moreover, the preheating heaters 32 and 34 are formed in a substantially U-shape along the axial direction of the pipe 10, and have distal ends having an arc shape along the circumferential direction of the pipe 10, and are arranged so that these distal ends face each other. Therefore, the pipe 10 can be preheated uniformly.

That is, as shown in FIG. 7, the preheating temperature difference Δt of the pipe 10 with respect to the change in distance t from the end of the heater changes as shown by straight line A in the conventional device shown in FIG.
In the conventional device shown in the figure, the temperature changes as shown by straight line B, whereas on the actual flow side, the temperature changes as shown by straight line C, and the temperature change is extremely small compared to the conventional device.

FIG. 8 shows a comparison of all changes in preheating temperature along the longitudinal direction of the pipe 10 between this embodiment and the device described above. , in the conventional device shown in No. 21a, the heater 2
In the middle of February 2 and 24, the temperature at the welded part 12 was lower than that of the part facing the heater by Δto. Further, in the conventional device shown in FIG. 1, the preheating temperature of the pipe 10 is lowered by Δt at the intermediate portion between the heater 20 and the heaters 22 and 24. On the other hand, in this embodiment, the difference in the preheating temperature of the pipe 10 is Δt2 and the first
It is extremely small, about 1/4 of the device shown in the figure.

FIG. 9 and FIG. 10 show other embodiments of the preheating and heat-retaining device according to the present invention. In the embodiment shown in FIG. 9, the first insulation material 14 and the second insulation material 16.1
8, a multistage labyrinth 54 is formed to enhance the preheating effect and heat retention effect 'k-N. In this way, the first heat insulating material 14 and the heat insulating material 16.18 of ν÷2
Even if the 71 part is large, the preheating heaters 32, 34
Since it is formed in a U-shape along the axial direction of the pipe 10, there is no need to worry about the deterioration of the preheating and heat retention effect.

FIG. 10 shows an example in which the first heat insulator 14 is divided into an outer heat insulator 56 and an inner heat insulator 58. By doing this, the outer diameter of the piping 10 is not large.If the first heat insulating material 112 is divided into two parts, it will be difficult to remove or attach the first heat insulating material 112. The outer insulation material 56
and an inner heat insulating material 58, so that removal and attachment can be easily performed.

〔Effect of the invention〕

As explained above, according to the present invention, the heater is formed into a substantially U-shape along the axial direction of the heated object, and its tip is shaped along the circumferential direction of the heated object, so that the heater By attaching it to the second heat insulating material placed on the side of the first heat insulating material that covers the periphery of the inspection part of the heated object, the inspection part of the heated object can be easily inspected. , the preheating temperature difference can be reduced.

[Brief explanation of drawings]

1 and 2 are vertical cross-sectional views showing examples of conventional preheating and heat retention devices, FIG. 3 is a longitudinal sectional view of an embodiment of the preheating and heat retention device according to the present invention, and the fourth figure is a longitudinal sectional view of an example of a conventional preheating and heat retention device. Fig. 5 is a sectional view taken along the line ■-■ of Fig. 3, and Fig. 6 is a cross-sectional view taken along the line ■-■. Fig. 7 shows the relationship between the distance from the heater and the preheating temperature difference of the pipes, Fig. 8 shows the preheating temperature distribution of the pipes, and Figs. 9 and 10 show the preheating temperature distribution of the pipes. It is a figure which shows another example of the preheating heat retention effect based on this invention. 10... Piping, 12... Welding part, 14, 15...
First heat insulating material, 16.18... Second heat insulating material, 32.
34... Preheating heater, 40.42... Heating section. Agent Patent Attorney Takanobuo and Yu 4-Figure 5 Figure 6 Figure 7 Rabbit Figure 8

Claims (1)

[Claims] 1. A first heat insulating material that can be attached and detached around the inspection part of the heated object, a second heat insulating material that covers the heated object and arranged on the side of the first heat insulating material, and the heated object In a preheating heat retention device having a plurality of heaters provided along the outer surface of the
The heater is formed in a substantially U-shape along the axial direction of the object to be heated, and has a tip portion shaped along the circumferential direction of the object to be heated, and the tip portion is shaped so as to extend along the circumferential direction of the object to be heated. A preheating and heat-retaining device, characterized in that the preheating and heat-retaining device is attached to the second heat-insulating material so as to face the second heat-insulating material.