Field of the Invention: The invention relates generally to a dual pipe in a boiler. More particularly, the invention relates to a dual pipe in a boiler, in which an inner pipe into which lagging materials are filled is twofold inserted into an outer pipe used as a water pipe and a hot-water pipe, so that the amount of water circulated within an outer pipe is reduced to raise the temperature of water up to a desired temperature at a short period of time.

Description of the Prior Art: Generally, boilers such as a coal boiler, a gas boiler, an oil boiler, or the like have a combustion chamber. The water pipe that is heated by a burner usually has a coil shape Water within the water pipe is heated using heat of the burner.

As the entire heated water is injected into the pipe (assuming that the diameter of the pipe is 20 cm), lots of time is required to heat the water. Therefore, there is a problem that lots of fuels are consumed in order to heat water up to a desired temperature.

SUMMARY OF THE INVENTION The present invention is contrived to solve the above problems and an object of the present invention is to provide a dual pipe in a boiler, in which an inner pipe into which lagging

materials are filled is twofold inserted into an outer pipe used as a water pipe and a hot-water pipe, so that the amount of water circulated within the outer pipe is reduced to raise the temperature of water up to a desired temperature at a short period of time.

Another object of the present invention is to provide a dual pipe in a boiler capable of preventing heated hot water from rapidly cooling due to lagging materials by filling the lagging materials into the inner pipe inserted into the outer pipe.

BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned aspects and other features of the present invention will be explained in the following description, taken in conjunction with the accompanying drawings, wherein: Fig. 1 is a perspective view of a dual pipe according to one embodiment of the present invention; Fig. 2 is a cross-sectional view of the dual pipe shown in Fig. 1; DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention will be described in detail by way of a preferred embodiment with reference to accompanying drawings, in which like reference numerals are used to identify the same or similar parts.

Fig. 1 is a perspective view of a dual pipe according to one embodiment of the present invention, Fig. 2 is a cross-sectional view of the dual pipe shown in Fig. 1.

The dual pipe 100 according to the present invention includes an inner pipe 11 that is

twofold inserted into an outer pile 10, and lagging materials 12 filled within the inner pipe 11, as major components.

The inner pipes 11 are spaced and supported a given distance by the welding, furthermore the inner pipe 11 is inserted into the outer pipe 10.

At this time, the dual pile 100 constructed above is installed at a combustion chamber of the boiler. Further, the inner pipe 11 (for example, assuming that the diameter of the outer pipe is 20cm and the diameter of the inner pipe is 10 cm) has the lagging materials that are inserted into the water outer pipe 10 heated by the burner. With this construction, it was found that the amount of water injected into the outer pipe 10 is reduced by half than those injected into the conventional outer pipe. Further, as the amount of heat is applied to the outer pipe with the same state, the injected and circulated water can be rapidly heated. In addition, the time to heat water is reduced.

The heated hot water is not rapidly cooled by means of the lagging materials 12 filled into the inner pipe 11 when the water is circulated.

As mentioned above, according to the present invention, the inner pipe that is supported by the support pole, for maintaining the distance of the support pole is installed within the outer pipe, thus reducing the amount of water circulated within the outer pipe.

Therefore, the present invention has outstanding advantages that water injected into the outer pipe can be heated within a short period of time, the time to heat water is reduced to reduce the fuel consumption and the temperature of water circulating through the hot- water pipe can be kept for a long period of time by lagging materials filled within the inner pipe.

The present invention has been described with reference to a particular embodiment in connection with a particular application. Those having ordinary skill in the art and access to the teachings of the present invention will recognize additional modifications and applications within the scope thereof.

It is therefore intended by the appended claims to cover any and all such applications, modifications, and embodiments within the scope of the present invention.