Note: Descriptions are shown in the official language in which they were submitted.
CA 02613575 2007-12-04
The invention relates to a protected carbon steel pipe for conveying
flue gases in a heat exchange apparatus.
It is known that there are heat exchange apparatuses, such as for
example fire tube boilers for generating hot water or another heat transfer
fluid, or different apparatuses of industrial thermal cycles, such as for
example condensers, economizers, heat exchangers, which provide for the
presence of pipes designed to convey flue gases produced by combustion in
appropriately provided furnaces, inserted within a vessel which contains the
fluid to be heated.
The pipes comprised within such apparatuses are made of carbon
steel in order to ensure optimum quality of the welded joints between the
pipes and the structures of the apparatuses, which are also made of carbon
steel, and in the case of apparatuses such as for example condensing boilers,
in which the water vapor contained in the flue gases condenses inside the
flue gas conveyance pipes, forming corrosive condensation, the internal
surface of the pipes is protected in different manners.
For example, pipes have been proposed which comprise an outer
jacket which is made of carbon steel and is provided internally with a
plurality of contiguous sectors which are made of corrosion-resistant
material and are provided with variously shaped fins, but in this
embodiment flue gases can penetrate between one sector and the other, with
the consequent possibility of contact of such flue gas, which has cooled and
therefore carries corrosive condensation, with the outer jacket, which
accordingly is not protected fully.
The aim of the present invention is to provide a protected carbon steel
pipe which comprises the elements described above and in which full
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protection of the outer jacket made of carbon steel is ensured.
The proposed aim is achieved by a protected carbon steel pipe for
conveying flue gases in a heat exchange apparatus, according to the
invention, comprising an outer jacket made of carbon steel, which is
provided internally with a plurality of contiguous sectors made of corrosion-
resistant material and provided with variously shaped fins, characterized by
the presence of a continuous layer made of corrosion-resistant material
which is interposed and in contact between said outer jacket and said
plurality of contiguous sectors.
Further characteristics and advantages of the present invention will
become better apparent from the description of two preferred but not
exclusive embodiments of the invention, illustrated by way of non-limiting
example in the accompanying drawings, wherein:
Figure 1 is a transverse sectional view of the protected carbon steel
pipe according to the invention;
Figure 2 is a transverse sectional view according to a different
embodiment.
With reference to Figure 1, the reference numeral 1 generally
designates a pipe according to the invention, which comprises an outer
jacket 2 made of carbon steel and provided internally with contiguous
sectors 3, 4, 5 made of corrosion-resistant material, such as for example
aluminum alloy or stainless steel, and which are provided with fins 3a, 4a,
5a respectively for the sectors 3, 4, 5.
An important feature of the invention is the presence of a continuous
layer 6 made of corrosion-resistant material, which is interposed between
the outer jacket 2 and the sectors 3, 4, 5 and adheres both to the jacket and
to the sectors.
In this manner, the outer jacket 2 made of carbon steel has a complete
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protection against corrosion, because any infiltrations of flue gases between
one sector and the other are blocked by the layer 6 and any contact between
the flue gases and the jacket is thus prevented.
The embodiment of Figure 2 illustrates a pipe 7 in which the outer
jacket 8 made of carbon steel is provided internally with a plurality of
sectors 9 which are made of corrosion-resistant material and are provided
with fins 9a, 9b, which are shaped so as to define a plurality of flue gas
conveyance modules which are substantially shaped like sectors.
In the second embodiment, the reference numeral 10 designates the
continuous layer made of corrosion-resistant material which, interposed so
as to adhere between the outer jacket 8 and the plurality of sectors 9,
provides full protection of the jacket against any infiltrations of flue gases
which may occur between one sector and another.
The described invention is susceptible of numerous modifications and
variations, all of which are within the scope of the appended claims; all the
details may further be replaced with other technically equivalent elements.
