JP2012063125A - Composite heat exchanger tube for exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite heat exchanger tube for exhaust gas, for preventing the progress of corrosion of a steel pipe due to corrosive gas produced in refuse incineration, in the steel pipe for hot-water supply or steam, installed in a refuse incinerator or the like.SOLUTION: The steel pipe 22 is protected by covering the outer periphery thereof with a ceramic tube 23 having an inner diameter larger than the outer shape of the steel pipe 22, and consequently the steel pipe 22 is not affected by the corrosive gas and only the combustion heat is transferred to the steel pipe 22.

Description

Detailed Description of the Invention

  The present invention relates to an exhaust gas composite heat transfer tube for excluding erosive gas for hot water supply provided in, for example, a waste incinerator or a steel tube for steam power generation.

  In a steel pipe provided in a garbage incinerator, flame or erosive gas directly burns into the steel pipe, and the corrosion of the steel pipe is fast and the life of the steel pipe is said to be about 10 years.

Problems to be solved by the invention

Garbage incineration is carried out not only in Europe and the United States but also in Japan, and even plastics such as plastic bottles are collected and collected, but most plastics such as other containers and trays are collected. Is collected as burning garbage.
In recent years, there is an opinion that plastic waste is more efficient to be used for power generation as fuel than to be recycled.
In other words, plastic among waste incineration has a particularly high calorific value and is an excellent fuel for steam power generation.
However, the erosive gas generated during this incineration is a problem, and the development of a long-lasting steel pipe that can withstand this is currently an issue.

Means for solving the problem

  In order to solve the above problems, a ceramic tube is placed on the outer periphery of the steel pipe as a protection so that the hot water supply installed in the incinerator or the steel pipe for steam (metal pipes) does not directly ignite flame or erosive gas. .

  The form of the exhaust gas composite heat transfer tube of the present invention is made of the ceramic tube and the steel tube which are covered with a ceramic tube (a tube made of clay baked at a high temperature) which is thicker than the conventional steel tube and is provided with a gap. In this case, a non-ferrous metal piece (gravel shape) such as lead having a melting point lower than that of the steel pipe is introduced into the space part to form a triple structure of the pipe and the tube.

  Or, the outer circumference of a conventional steel pipe is covered with a ceramic pipe slightly thicker than the steel pipe, and pipes of different materials are made into a double structure.

An embodiment of the present invention will be described with reference to FIGS.
1, a ceramic tube 3 is put on the outer periphery of the steel tube 2, a lead inlet 4 is provided at one end of the ceramic tube 3, and a lead outlet 5 is provided at the other end.

  And the lead 7 made into gravel is thrown into the space part of the steel pipe 2 and the ceramic pipe 3, However, It does not necessarily select lead but selects from the nonferrous metal lower than melting | fusing point of a steel pipe.

  The exhaust gas composite heat transfer tube 1 is not limited to a straight tube but may be connected in a meandering manner using a U-shaped tube or the like. In any case, the exhaust gas combined heat transfer tube 1 is provided with a gradient so that lead melted by heat can flow out. And the part provided in the inside of the incinerator 6 is always a composite pipe composed of the steel pipe 2, the ceramic pipe 3 and the lead 7. Further, the lead inlet 4 and the lead outlet 5 are always provided outside the incinerator 6.

In FIG. 2, a ceramic tube 23 is placed on the outer periphery of the steel tube 22 with a gap 24 provided. In this case, a U-shaped tube may be used to connect in a meandering manner. The method of providing the gap 24 is arbitrary.
In the case of the exhaust gas combined heat transfer tube 21 as well, when it is attached to the incinerator, the left and right end portions of the ceramic tube 23 are always provided outside the incinerator.

In FIGS. 1 and 2, when a U-shaped ceramic tube is covered, a tubular product is formed by combining molded parts by split molds, and the joint is packed with a similar putty material and joined.
However, when performing installation using only a plurality of straight pipes, the U-shaped part is provided outside the incinerator.

Action

  The exhaust gas combined heat transfer tube 1 of FIG. 1 is provided in the incinerator 6 part, and a pipe for water supply is connected to the left side of the steel pipe 2 extending outside the incinerator 6, and the right side is for steam Connect the piping.

When the waste in the incinerator 6 is combusted, the ceramic tube 3 is first heated, and the heat of the lead 7 heats up to become a melt. The heat of the lead 7 that becomes the melt heats the steel tube 2. The water flowing in the steel pipe 2 is boiled to generate steam.
At this time, even if a very small part of the erodible gas generated in the waste incinerator penetrates into the ceramic tube 3 and enters the lead 6 melt, the gas remains in the melt as bubbles. Therefore, the steel pipe 2 is not corroded because it is discharged from the lead inlet 4, and therefore the erosive gas does not have to touch the steel pipe 2.

  The lead 7 is oxidized by being heated, and the oxide becomes debris and floats up to the lead insertion port 4. The debris is removed and a new lead material is replenished.

  When the exhaust gas combined heat transfer tube 21 of FIG. 2 is provided in the incinerator, even if a part of the erodible gas penetrates into the ceramic tube and enters the gap 24, it is discharged from the openings on the left and right ends. Therefore, even if the steel pipe 22 is attacked by gas, the rate is very small.

The invention's effect

When the exhaust gas composite heat transfer tube 1 of FIG. 1 is used in an incinerator 6, erosive gas due to dust combustion first hits the ceramic tube 3, even if a very small amount of the gas penetrates the ceramic tube 3, The gas hits the melt of lead 7 and is generated as bubbles from the lead inlet 4, so that the steel pipe 2 has an excellent effect of not being attacked by the erodible gas.
Moreover, the incineration heat has an effect that the degree of adhesion between the ceramic tube 3 and the lead 7 and the steel tube 2 is high and the heat transfer effect is very large.

  The exhaust gas composite heat transfer tube 21 in FIG. 2 is provided with a gap 24 between the steel tube 22 and the ceramic tube 23 as small as possible (considering thermal expansion), has a high heat transfer effect, is easy to manufacture, The exhaust gas effect on the steel pipe can be sufficiently obtained.

The ceramic tube used is manufactured by baking clay at a temperature of about 1,100 ° C., and is excellent in strength, airtightness, heat resistance, gas resistance and chemical resistance, and is said to be semi-permanent.
Therefore, the effect of “heat transfer and exhaust gas” on the steel pipe, which is the object of the present invention, is very large, and the effect of prolonging the life of the steel pipe compared to the conventional method is also great.

  1 is a schematic cross-sectional view of an exhaust gas composite heat transfer tube 1 of the present invention installed in an incinerator 6. FIG.   2 is a cross-sectional view of an exhaust gas composite heat transfer tube 21. FIG.

1 Exhaust gas combined heat transfer tube 6 Incinerator 21 Exhaust gas combined heat transfer tube 2 Steel tube 7 Lead 22 Steel tube 3 Ceramic tube 8 Water supply port 23 Ceramic tube 4 Lead inlet 9 Steam port 24 Crevice 5 Lead outlet

Claims (2)

  The outer circumference of the steel pipe is made larger in diameter than the outer circumference of the steel pipe, and further, a ceramic pipe provided with a metal piece inlet on one end and an outlet for the metal piece on the other end is covered. The space formed by the steel pipe and ceramic pipe is made of a non-ferrous metal piece or non-ferrous metal particle such as zinc or lead having a melting point lower than that of the steel pipe, thereby forming a tube and tubular triple structure of different materials. Exhaust gas combined heat transfer tube.   An exhaust gas combined heat transfer tube characterized in that the outer periphery of the steel pipe is covered with a ceramic tube having an inner diameter larger than that of the outer periphery of the steel tube to form a double structure of tubes of different materials.

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