JPH0458872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for constructing an inner cylinder of a double-tube chimney.

(Prior Art) Figures 8 and 9 show a conventional construction method for repairing and replacing the inner cylinder in a multi-legged, double-tube type chimney, where a is the multi-legged chimney and b is the outer cylinder. The material c is the inner cylinder material to be replaced, and the prefabricated inner cylinder part d is carried into the outer cylinder material through the carrying opening e provided in the outer cylinder material, and the inside of the outer cylinder material is replaced by the gondola f. It is transported to a predetermined position and joined to the lower inner cylinder part.

(Problems to be Solved by the Invention) In the conventional method described above, when transporting the inner cylinder material to a predetermined position, the size of the carry-in opening provided in the outer cylinder material is limited, and the outer cylinder has bends. Due to such reasons, it was necessary for the inner cylinder material to be carried in to be a partially arcuate member rather than a completely arcuate member.

Therefore, it is necessary to perform multiple rows of vertical seams and circumferential welding at installation locations that are shielded from the outside world at high places and have a poor work environment.In addition, gondolas must be frequently moved inside the outer cylinder to transport the inner cylinder material. Another problem was that it needed to be moved and the construction period was long.

(Means for Solving the Problems) The present invention relates to a method for constructing an inner cylinder of a double-tube type chimney, which has been proposed in order to solve the above-mentioned problems. The partially polymerized and reduced diameter rolled steel pipe is carried into the outer cylinder from the upper end of the chimney and moved to a predetermined position, and then the inner pipe made of the rolled steel pipe is expanded to a predetermined diameter and placed in the lower part. The above problem is solved by attaching it to the upper part of the inner cylinder.

(Function) As described above, in the present invention, the inner cylinder material to be carried into the chimney outer cylinder is made into a rolled steel pipe whose diameter is reduced so that both ends in the circumferential direction are partially overlapped. By carrying the steel pipe into the outer cylinder from the upper end of the chimney, it can be easily moved to a predetermined position within the outer cylinder.

When the inner cylinder material whose diameter has been reduced in this way is moved to a predetermined position within the outer cylinder, the inner cylinder material is expanded to a predetermined diameter and attached to the upper part of the existing lower inner cylinder, and the same steps as described above are carried out. The inner cylinder of the double-tube chimney is constructed by repeating the process.

(Example) The present invention will be described below with reference to the illustrated embodiments.

1 is an inner cylindrical material, as shown in FIGS. 4 to 6, a steel plate is bent to a predetermined curvature by rollers 2 in a factory, and the vertical seam is not welded to reduce the diameter, but the circumferential seam is Both end pieces in the direction are polymerized by Δl,
The two end pieces are temporarily fixed with tie bars 3 to form a rolled steel pipe. Note that a heat insulating material 4 is attached in advance to the outside of the inner cylinder material 1 if necessary.

On the other hand, in order to carry the inner cylinder material 1 into the chimney, the smoke collection section 5 at the top of the chimney is removed by the post crane 6. (See Figure 7) After removing the smoke collecting section 5, as shown in Figure 1, a support frame 8 is attached to the top of the chimney outer cylinder member 7, which serves as a gondola pedestal and a beam for lifting the inner cylinder member. .

In the figure, 9 is a sheave for raising and lowering the gondola 10 provided on the top beam of the support frame 8, 11 is a hoisting cable of the gondola, 12 is a sheave for lifting and drawing the inner cylinder material provided on the top beam of the support frame 8, 13 is a hoisting cable made of the same inner cylinder material, and each hoisting cable 11, 13 is wound in and unwound by a winch (not shown) provided on the ground side. Reference numeral 14 denotes a guide rope for raising and lowering the gondola, which is stretched from the top beam of the support frame 8 to the lower end inside the outer cylinder member 7.

To take in the inner cylinder 1, the gondola 10 is temporarily fixed to the top of the support frame 8, and the inner cylinder 1 is lifted up by a winch and shifted below the gondola 10. (See FIG. 1) Thereafter, the gondola 10 is inserted into the inner cylinder member 1, and as shown in FIG. 2, it is suspended and temporarily fixed onto the gondola 10 by the chain block 15.

Regarding the retraction of the inner cylinder member 1, as shown in FIG.
is removed and the rope 14 is temporarily fixed to the gondola. Next, the gondola 10 is lowered and the rope 14 is temporarily fixed to the outer cylinder member 7 as shown in FIG. 2B. Thereafter, as shown in FIG. 2C, the gondola 10 is lifted to the top again and the inner cylinder member 1 is drawn into the outer cylinder member 7. Further, the gondola 10 is lowered through the inner tube member 1, the guide rope 14 is picked up and temporarily fixed to the gondola 10, and the gondola 10 is raised again and the guide rope 14 is fixed at a predetermined top. At this time, the gondola 10 ascends and descends without a guide rope, but the work is possible because the top of the chimney is vertical and the vertical distance is short. After fixing the guide rope 14 to the top of the support frame 8, the gondola 10 is lowered within the inner tube member 1, and as shown in FIG. 2D, the inner tube member 1 is secured to the gondola 10 and guided by the gondola 10. The wheels 10a are set and preparations for descent are completed.

Next, the gondola 10 supporting the inner cylinder member 1 is suspended and moved to a predetermined mounting position within the outer cylinder member 7, and then the tie bar 3 is cut to enlarge the inner cylinder member 1 to a predetermined diameter. (See FIG. 3) Furthermore, a guide 16 and a chill plate 17 are attached in advance to the inner tube member 1', which has been previously attached, so that the inner tube member 1 can be easily attached.

After the inner cylinder member 1 is thus set in a predetermined position, the inner cylinder member 1 is fixed to the existing inner cylinder member 1' by vertical and circumferential seam welding, and the same steps as described above are repeated. Extend the inner cylinder to the top of the chimney.

After the installation of the inner cylinder is completed in the manner described above, the smoke collection section 5 is restored, and the entire process is completed. The inner cylinder of the smoke collection section will be constructed using conventional construction methods.

Furthermore, to remove the inner cylinder when replacing a double-tube type chimney, the inner cylinder is cut into small pieces from the upper part using the gondola 10, and the cut pieces of the inner cylinder are lowered into the chimney. This is done by taking it out from the duct connection at the bottom of the chimney.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

(Effects of the Invention) In the present invention, the chimney inner cylinder material is a rolled steel pipe whose diameter is reduced by partially polymerizing both ends in the same direction, so that it can be carried into the outer cylinder from the upper end of the chimney. It can be easily moved to a predetermined position within the outer cylinder, and by expanding the inner cylinder material to a predetermined diameter at the same position and joining it to the upper part of the lower inner cylinder, the repair process is shortened and the construction period is reduced. This reduces construction costs.

[Brief explanation of the drawing]

1, 2A to 2D, and 3 are longitudinal cross-sectional views showing steps of an embodiment of the method for constructing an inner cylinder of a double-tube chimney according to the present invention, and FIG. Fig. 5 is a cross-sectional plan view of the inner cylinder material, Fig. 5 is a partially cutaway slope view, Fig. 6 is a slope view showing its molded state, and Fig. 7 shows the smoke collection section removed. Front view,
FIG. 8 is a front view showing the state of implementation of the conventional method, and FIG. 9 is a view taken along the arrow in FIG. 1... Inner tube material, 3... Tie bar, 7... Outer tube material, 8... Support frame, 10... Gondola.

Claims (1)

[Claims] 1. After carrying the chimney inner cylinder material into the outer cylinder from the top end of the chimney as a rolled steel pipe whose diameter has been reduced by partially polymerizing both ends in the circumferential direction and moving it to a predetermined position, A method for constructing an inner cylinder of a double-tube type chimney, characterized by expanding a cylinder material to a predetermined diameter and attaching it to the upper part of a lower inner cylinder.