JPH0151625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a method of manufacturing a chimney for a stove used for heating a house.

In cold regions, indoor heating generally uses multiple large pot-type kerosene stoves, and the exhaust gas from each stove is discharged outdoors through a collective chimney. Traditionally, chimneys used for this purpose include stacking concrete blocks, placing a ceramic pipe, etc. in the center, and filling the space between them with concrete.
The exterior is mortared or
The method used in this application is to stack reinforcing bars vertically through lightweight cellular concrete blocks containing ceramic pipes and slate pipes.

However, in the former case, since the weight of the chimney is heavy, a foundation with sufficient strength is required, and there is a limit to the number of stacks that can be stacked at one time, so construction takes a long time and is expensive. Furthermore, there were other problems such as cracks in the exterior mortar, which impaired the aesthetic appearance. The latter is lighter in weight than the former and requires a shorter construction period, but it requires more time to manufacture as it involves drilling a through hole in the center of the lightweight cellular concrete block and burying the slate pipe or ceramic pipe, and it also requires a shorter construction time. It requires skill to stack up the blocks while joining them in multiple stages, and due to the difference in thermal expansion coefficient between the slate pipe and lightweight cellular concrete, and the temperature difference between the inside and outside surfaces of the lightweight cellular concrete block, it may be difficult to build up the blocks during long-term use. Cracks could occur.

The present invention aims to solve the above-mentioned drawbacks, and the outer cylinder is made of a long lightweight cellular concrete square timber with reinforcing bars installed in advance, and an inner cylinder made of heat-resistant and corrosion-resistant material is inserted into the center of the outer cylinder. To provide a method for manufacturing an integrated chimney by providing a cavity between a cylinder and an inner cylinder.

An example of a lightweight cellular concrete chimney manufactured by the method of the present invention will be explained in detail below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a lightweight cellular concrete chimney, and FIG. 2 is a sectional view taken along line A--A in FIG. Inside the lightweight cellular concrete outer cylinder 1, which has a substantially square cross-sectional shape, there are main reinforcing bars 2a in the longitudinal direction, which are fixed perpendicularly to the main reinforcing bars 2a to form a rectangle, thereby forming a cage-shaped reinforcing bar mat 2 as a whole. The auxiliary reinforcing bars 2b are arranged so that. Further, a cylindrical through hole 3 penetrates through the center in the longitudinal direction. Further, two ventilation holes 6 are penetrated toward the through hole 3 at opposing positions on the side surface near one end in the longitudinal direction.
Inside the through hole 3 is an inner cylinder 4 made of slate.
Near both ends in the longitudinal direction are held approximately at the center of the through hole 3 by a pair of semicircular supports 5 and 5a, and a gap 7 is formed between the outer cylinder 1 and the inner cylinder 4 over the entire length. Penetrating. The supports 5 and 5a are a set of flat iron whose central part is processed into a semicircular shape, and both ends of which are fixed to the main reinforcing bars 2a of the outer cylinder 1 and buried in lightweight cellular concrete. . The number of sets of supports used may be three or more. The inner tube 4 may be made of, for example, a stainless steel tube or a ceramic tube as long as it has heat resistance and corrosion resistance against exhaust gas from a stove or the like, but it is economical to use a slate tube alone or a slate tube covered with a thin iron plate. The dimensions of the chimney having the above structure are, for example, the outer diameter of the outer cylinder is 30 cm square, the length is 6 m, the diameter of the through hole 3 is 15 cm, the outer diameter of the inner cylinder 4 is 12 cm, and the diameter of the vent hole 6 is 3 cm. These can be manufactured by changing the dimensions and shape as desired, but the dimensions of the air hole 7 and the ventilation hole 6 between the inner cylinder 4 and the outer cylinder 1 should be at least 1 cm and 3 cm, respectively, to prevent the ventilation resistance from becoming excessive. It is desirable that

When installing this chimney, it should be placed vertically on a base that has an outlet for removing soot and ash that has adhered to the inside surface of the chimney, with the ventilation hole 6 facing downward, and the top should be installed horizontally, which is usually used. It is also possible to install a block with an opening in the chimney, and if necessary, support the side or middle part of the chimney on the building, or provide a branch part for inserting exhaust pipes from multiple stoves. In addition, if it is necessary to limit the weight of one piece, the overall length can be shortened and two to four through holes can be arranged in symmetrical positions near the outer periphery of the lightweight aerated concrete part of the outer cylinder 1 in the longitudinal direction. It is also possible to connect several bars by inserting reinforcing bars into the through holes and filling them with concrete.

Next, an embodiment of the method for manufacturing a chimney according to the present invention will be described (FIGS. 1 to 3).

First, the longitudinal main reinforcing bars 2a are fixed to the rectangular auxiliary reinforcing bars 2b arranged at predetermined intervals in the direction perpendicular to the longitudinal direction of the outer cylinder 1, and the elongated square cage-shaped reinforcing bar mat 2 is assembled. The tip of the vertical portion of the auxiliary reinforcing bar 2b shown in FIG.

Next, a pair of supports 5 and 5a, each made of flat iron with a semicircular center and a key shape at both ends, are attached so as to sandwich the slate cylinder 4 near both ends. The outer circumferential surface of is covered with a foamed thermoplastic resin 7a having a desired thickness. This resin may be used by covering the cylinder with styrofoam or urethane foam, which is divided into two parts, and adhering the joints with tape, or by wrapping a urethane foam tape of a desired thickness. Further, the openings at both ends of the inner cylinder 4 are covered with lids 3a, such as by pasting cardboard.

The inner cylinder 4 processed in this way is inserted into the reinforcing bar mat 2, and both ends of the support 5 are fixed to the main reinforcing bar 2a. Further, near one end of the reinforcing bar mat 2 in the longitudinal direction, one end of a foamed polystyrene cylinder 6a having approximately the same size as the ventilation hole 6 of the outer cylinder 1 abuts against the foamed thermoplastic resin 7a of the inner cylinder 4. Install vertically.

The reinforcing bar mat 2 with the inner cylinder 4 attached in this way is
Concrete is placed in a formwork 8 whose length in the longitudinal direction is slightly larger than the length of the inner cylinder 4, and is made into a slurry by mixing a foaming agent and water with silicic raw materials such as silica sand, cement, and calcareous raw materials such as lime. The raw material mixture is injected into the form and foamed. After a certain period of time has passed and the mold becomes semi-plastic, the mold 8 and the lid 3a of the inner cylinder 4 are removed, and the mold is placed in an autoclave and subjected to high temperature and high pressure steam curing at approximately 180° C. for several hours. Then, the foamed thermoplastic resin melts and shrinks due to the high temperature, and almost disappears, resulting in a lightweight cellular concrete chimney having voids 7 and ventilation holes 6 on the outer periphery of the inner cylinder 4. Furthermore, by placing a group of reinforcing bar mats of a desired size in a larger formwork, a large number of chimneys can be manufactured at once. Further, the ventilation holes 6 may not be provided in advance but may be bored from the outer periphery of the outer cylinder 1 during construction.

According to the above-described manufacturing method, a lightweight cellular concrete chimney having a void between the inner and outer cylinders can be manufactured in a simple process, and therefore industrial mass production is possible and extremely practical.

Since the chimney of the present invention is significantly lighter than conventional concrete chimneys and is formed into a monolithic structure with desired dimensions, the foundation can be simple and the installation work can be completed in a very short time. Further, since a space is provided between the outer cylinder and the inner cylinder, even if the materials of the inner and outer cylinders have different coefficients of thermal expansion, they do not adversely affect each other, thereby preventing the occurrence of cracks. In addition, outside air rises through the air space between the inner and outer cylinders by natural draft from the ventilation holes opened on the lower side of the outer cylinder, cooling the outer surface of the inner cylinder and the inner surface of the outer cylinder to prevent overheating. Since the temperature difference between the inner and outer surfaces of the outer cylinder is reduced, it can be used safely for a long time without causing cracks in the outer cylinder. It is also possible to forcefully ventilate the air between the inner and outer cylinders and use the heat-exchanged warm air to heat the building. It goes without saying that the chimney of the present invention can be used not only for heating purposes but also as a chimney for general combustion furnaces and kitchen ventilation.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a chimney manufactured by the method of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a diagram showing the arrangement within the formwork. 1...Outer cylinder, 2...Reinforced mat, 3...Through hole,
4...Inner cylinder, 5...Support, 6...Vent hole, 7...
...Void, 8...Formwork.

Claims (1)

[Claims] 1 The outer periphery of an inner cylinder made of heat-resistant and corrosion-resistant material is coated with foamed thermoplastic resin, and at least two sets of supports are installed with the longitudinal direction of reinforcing steel bars placed in a formwork for manufacturing lightweight cellular concrete, with the longitudinal direction horizontal. The inner cylinder is suspended, a concrete raw material mixture mixed with a foaming agent is injected into the mold and foamed, and the foamed thermoplastic resin is melted and shrunk by high temperature and high pressure steam curing, and the inner cylinder and lightweight A method for manufacturing a lightweight aerated concrete chimney, characterized by forming a void between the aerated concrete outer cylinder and the chimney.