JPH03638Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a heat insulated pipe.

(Prior art and its problems) When transporting fluids that require heating and heat retention, such as high viscosity fluids such as heavy oil, and caking fluids such as benzene and phthalic anhydride, A heat insulating pipe is used in which a heating pipe for heating the fluid is attached along the axial direction of the supply pipe for flowing the fluid, and these are surrounded by a heat insulating layer.

In this type of insulated pipe, there is a temperature difference of 40 to 70°C between the temperature of the supply pipe and the temperature of the heating pipe, so a mechanism is required for the heating pipe to absorb expansion and contraction due to thermal expansion, separate from the supply pipe. Ru.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 57-154585, the present applicant formed a heating tube with a curved tube section that curves in the circumferential direction along the outer periphery of the supply tube and whose end reaches near the end of the supply tube. We proposed a unit heat-insulated pipe.

When installing the unit insulated pipes mentioned above in the pipe axis direction,
The expansion and contraction absorbing tube section was formed in the heating tube simply by connecting the bent tube sections of the supply tube and the heating tube, which was advantageous because it could absorb the sliding movement caused by thermal expansion and contraction of the heating tube.
On the other hand, a spiral bent tube portion must be formed at the tube end of the heating tube. Such heating tubes are cumbersome not only to process but also to store and transport due to their bulk. Furthermore, when attaching the heating tube to the supply tube, it is necessary to insert the heating tube into the supply tube from the axial direction of the tube due to the bent tube portion, and it is also troublesome to manufacture unit heat-insulating tubes.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a heat insulating pipe that is easy to manufacture and can absorb the sliding movement caused by thermal expansion and contraction of heating pipes when the unit heat-insulated pipes are connected.

(Means for Solving the Problems) The insulated pipe of the present invention, which has been made to achieve the above-mentioned object, has linear heating pipes 3a and 3b sliding along the pipe axis direction on the outer surface of the supply pipe 2. A heat insulating pipe in which unit heat insulating pipes are movably attached, a heat insulating layer is formed surrounding the supply pipe 2 and the heating pipes 3a and 3b, and an outer pipe 5 is attached to the heat insulating layer 4 are connected in the pipe axial direction. One supply pipe 2 of mutually adjacent unit insulation pipes
and the other supply pipe 2 are connected, and the connecting pipe 10 is formed by bending the connected supply pipes 2, 2 into a coil shape.
a, 10b are loosely fitted, and the connecting pipes 10a,
One heating tube 3a, 3b and the other heating tube 3a, 3b are connected by the connecting tube 10b.
a, 10b, the insulating fiber layer 12 is connected to the supply pipe 2,
It is formed around 2.

(Function) According to the above means, since one heating tube and the other heating tube are connected by the coiled connecting tube loosely fitted into the connected supply tube, the tube axis direction generated in the heating tube is can easily absorb thermal expansion and contraction. Therefore, there is no need to form a bent tube part for absorbing thermal expansion and contraction at the tube end of the heating tube, and a straight heating tube that does not require special processing can be used. Therefore, even when the heating tube is attached to the outer surface of the supply tube along the tube axis direction, it can be attached from the radial direction of the supply tube, and the attachment operation is extremely easy. Furthermore, since the insulating fiber layer including the connecting pipe is formed around the supply pipe, it is possible to easily ensure the heat insulation properties of the connecting part while ensuring the deformation of the connecting pipe due to thermal expansion and contraction of the heating pipe. I can do it.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and shows a heat-insulating pipe in which unit heat-insulating pipes 1, 1 are connected in the axial direction of the pipe.

The unit heat insulation pipe 1 is a supply pipe 2 which becomes a fluid transport pipe.
and a pair of linear heating tubes 3 extending in the tube axis direction while being in slidable contact with the outer surface of the supply tube.
a, 3b, a heat insulating layer 4 formed around the supply pipe 2 including the heating pipes 3a, 3b, and an exterior pipe 5 fitted around the outer periphery of the heat insulating layer 4 to protect it. It's on.

The heat insulating layer 4 is formed between a first heat insulating layer 6 attached to the supply pipe 2 with an inorganic adhesive, and an outer layer pipe 5 formed of a spiral duct or the like and the first heat insulating layer 6. It consists of a filled second heat insulating material layer 7. The first heat insulating layer 6 is made of an inorganic material with excellent heat resistance and fire resistance, such as calcium silicate or water-repellent perlite, and the second heat insulating layer 7 is made of an inorganic foam material such as foamed alumina. There is. In this embodiment, since such an inorganic material is used as the heat insulating layer 4, it has a high heat resistance and is also excellent in fire resistance.

As shown in FIG. 3, the heating tubes 3a and 3b are housed in a space that is opened across a part of the first heat insulating material layer 6 on the supply tube side in the tube axis direction, and the space is filled. Insulating fibers 8, such as rock wool, are biased toward the supply pipe 2 and are slidably attached to the supply pipe 2 with metal fittings at predetermined intervals in the pipe axis direction. They are in slidable contact.

The heating tubes 3a and 3b are linear,
It is economical because it is easy to transport and store, and no special processing is required. Moreover, even when attaching along the axial direction of the supply pipe 2, it can be attached from the radial direction, and the attaching work is extremely simple.

Furthermore, at the tube end of the unit heat-insulated tube 1, the supply tube 2 and the pair of heating tubes 3a and 3b protrude from the end surface of the heat-insulating layer 4, and the protruding portion of the supply tube 2 is connected to the heating tube 3.
It is formed to be longer than those of a and 3b.

Next, a connection structure between the unit heat insulation pipes 1 having such a structure will be explained.

One supply pipe 2 and the other supply pipe 2 are connected by welding, and the heating pipes 3a and 3b are connected by connecting pipes 10a and 10b bent into coil shapes. The connecting pipes 10a, 10b
The twist directions are opposite to each other, and one connecting tube 10a and the other connecting tube 10b are wound alternately and attached to the connected supply tube. Further, the connecting pipes 10a, 10b and the heating pipes 3a, 3b are connected by welding through sockets 11.

The number of turns of the coils of the connecting pipes 10a and 10b is the first
In the figure, it is one turn, but it is of course not limited to this, and the unit length of the unit insulation pipe 1 and the heating pipe 3
It can be determined as appropriate depending on the type of heat medium flowing through a and 3b.

A heat insulating fiber layer 12 surrounded by rock wool or the like is formed around the supply pipes 2, 2 in which the connecting pipes 10a, 10b are arranged.
A protective tube 13 made of thin metal is fitted onto the outside. Since the connecting pipes 10a and 10b are embedded in the heat insulating fiber layer 12, they can be freely deformed in response to thermal expansion and contraction of the heating pipes 3a and 3b, and can effectively prevent heat loss. Construction is also easy. Further, the protection tube 13 is partially fitted onto the ends of the exterior tubes 5, 5, and is secured by a band 14 to the exterior tubes 5, 5.
This prevents water droplets and the like from flowing in from the connecting portion of the exterior pipes 5, 5.

FIG. 2 shows a second embodiment of the present invention, in which one heating tube 3a, 3b and the other heating tube 3a, 3b are
They are connected by connecting tubes 10'a and 10'b each having a 1/2 turn coil shape. If the left and right heating tubes 3a and 3b are connected alternately in this way, the transport fluid in the supply tube 2 can be heated more uniformly, which is preferable.
This is effective in environments where wind is constantly blowing into the insulated pipes from one direction. In this case, the number of turns of the coil is not limited to the illustrated example, but may be an integral number + 1/2 turns depending on the pipe length, etc.

Although FIGS. 1 and 2 show a pair of left and right heating pipes attached to the supply pipe,
The present invention is not limited to this, and it goes without saying that the heating tube may be one.

(Effect of the invention) As explained above, according to the invention, one heating pipe and the other heating pipe are connected at the connection part of the heat-insulating pipe in which the heating pipe is provided along the pipe axis direction. Since it is connected to the supply pipe through a coiled connecting pipe that is loosely fitted, construction is easy and thermal expansion and contraction occurring in the heating pipe can be easily absorbed. Therefore, there is no need to form a bent tube part for absorbing thermal expansion and contraction at the tube end of the heating tube, and a straight heating tube that does not require special processing can be used. Therefore, the heating tube according to the present invention is economical and easy to transport and store. Furthermore, when attaching the heating tube along the axial direction of the supply pipe, it can be attached from the radial direction of the supply pipe, making the attachment work extremely easy.
Therefore, unlike the conventional method, the troublesome work of inserting the heating tube into the supply tube from the tube axis direction is no longer necessary, and the unit heat-insulating tube can be manufactured easily. Furthermore, the length of the insulated tube can easily accommodate the magnitude of thermal expansion and contraction by simply adjusting the number of coil turns of the connecting tube depending on the type of heat medium flowing into the heating tube, so the structure of the unit insulated tube itself can be adjusted. Can be standardized. In addition, since the insulating fiber layer is formed around the supply pipe, including the connecting pipe, it is possible to easily ensure the heat insulation of the connecting part while ensuring that the connecting pipe does not deform due to thermal expansion and contraction of the heating pipe. can.

[Brief explanation of the drawing]

FIG. 1 is a first embodiment of the present invention, and is a partially cutaway sectional view showing a connection structure for heat-insulating pipes, and FIG. 2 is a partially cutaway sectional view showing a connection structure of a second embodiment of the present invention. FIG. 3 is a sectional view showing the structure of a unit heat-insulated pipe according to the present invention in an embodiment. 1...Unit heat insulation pipe, 2...Supply pipe, 3a, 3b
... Heating tube, 4 ... Heat insulation layer, 5 ... Exterior pipe, 10
a, 10b, 10'a, 10'b...Connecting pipe, 12
...Insulating fiber layer.

Claims (1)

[Claims for Utility Model Registration] Straight heating pipes 3a and 3b are slidably attached to the outer surface of the supply pipe 2 along the pipe axis direction, and a heat insulating layer is provided on the supply pipe 2 and the heating pipes 3a and 3b. A heat insulating pipe in which unit heat insulating pipes are formed in a surrounding manner and the outer pipe 5 is attached to the heat insulating layer 4 are connected in the tube axis direction, and one supply pipe 2 and the other of the mutually adjacent unit heat insulating pipes are insulated pipes. A connecting pipe 10 is connected to the supply pipe 2 and is bent into a coil shape between the connected supply pipes 2, 2.
a, 10b are loosely fitted, and the connecting pipes 10a,
One heating tube 3a, 3b and the other heating tube 3a, 3b are connected by the connecting tube 10b.
a, 10b, the insulating fiber layer 12 is connected to the supply pipe 2,
An insulated pipe characterized by being formed around 2.