CN100564680C - snow melting board - Google Patents

Abstract

Snow melting board with pipes comprising straight lines and U-shaped bends. The plate has a size of 300 mm to 5000 mm in parallel length of straight pipes and 100 mm to 4000 mm in vertical span of straight pipes. The pipe has a hot-dip galvanized or highly corrosion-resistant galvanized coating formed only on the outer surface of the pipe. The gap between adjacent pipes of the straight pipeline is preferably 100-300mm. Straight lines and bends are preferably made from one long pipe. The pipe is preferably made of steel pipe with a silicon content of less than 0.05 wt%, or not less than 0.15 wt%, but not more than 0.20 wt%.

Description

snow melting board

technical field

The present invention relates to a snow-melting board having pipes for flowing a heating medium such as ground water, warm water or antifreeze to melt snow on roads, bridges, etc. to prevent roads, bridges, etc. in cold regions from freezing.

Priority is given to Japanese Patent Application No. 2004-239153 filed on August 19, 2004 and Japanese Patent Application No. 2005-181597 filed on June 22, 2005, the contents of which are incorporated herein by reference.

Background technique

Conventional snow melting devices use embedded hot water pipes or heating devices to heat the surface of roads to melt snow on roads, bridges, etc. to prevent freezing of roads, bridges, etc. (Japanese Unexamined Patent Application, First Publication No. H02- 194280). This snow melting device uses materials such as resin pipes (Japanese Unexamined Patent Application, First Publication No. H07-109704), metal pipes (Japanese Unexamined Patent Application, First Publication No. H02-3714) and plated Zinc steel pipes (Japanese Unexamined Patent Application, First Publication No. H03-42136; Japanese Unexamined Patent Application, First Publication No. H02-194280) are used to flow heating media such as groundwater, hot water, and the like.

The resin tube has problems of poor strength and heat resistance. Also, in the case of asphalt paving for roads, since water containing a snow-melting agent seeps into the ground from the asphalt, corrosion resistance is also necessary for snow-melting boards or pipes used in snow-melting boards.

Therefore, there is a need to use a galvanized steel pipe excellent in corrosion resistance. The method proposed in Japanese Unexamined Patent Application, First Publication No. H03-42136 is a method in which straight pipes hot-dip galvanized on the inner and outer surfaces are formed into a zigzag shape by bending work or welding.

Japanese Unexamined Patent Application, First Publication No. S54-41235; Japanese Unexamined Patent Application, First Publication No. H11-246942 and Japanese Unexamined Patent Application, First Publication No. H05-148607 discloses a steel pipe wherein only the outer surface or the inner surface thereof is galvanized and a manufacturing method thereof.

A device for bending long steel pipes into a zigzag shape without welding has been proposed (Japanese Unexamined Patent Application, First Publication No. S60-238041; Japanese Unexamined Utility Model Application, First Publication No. H03-18914). However, there is no disclosure therein of a method and apparatus for applying hot-dip galvanizing to long steel pipes.

It is time-consuming and costly to bend or weld straight pipes with inner and outer surfaces hot-dip galvanized to form a zigzag shape disclosed in Japanese Unexamined Patent Application, First Publication No. H03-42136. In addition, when antifreeze is used as the heating medium, the galvanized layer on the inside of the pipe will chemically react with the antifreeze, causing the galvanized layer to dissolve. The method disclosed in Japanese Unexamined Patent Application, First Publication No. H03-42136 requires bending hot-dip galvanized straight pipes and U-bend pipes together, which can damage the galvanized layer at the welded portion of the outer surface of the pipes, thereby Deterioration of corrosion resistance. Therefore, it is necessary to repair the damaged part of the galvanized layer.

Use of the bending device disclosed in Japanese Unexamined Patent Application, First Publication No. S60-238041 and Japanese Unexamined Utility Model Application, First Publication No. H03-18914, on hot-dip galvanized long steel pipes Performing bending work causes damage such as peeling off of the plating surface at the bent section, thereby impairing corrosion resistance.

The present invention, made in consideration of the above-mentioned problems, provides a snow-melting board capable of using antifreeze as a heating medium, which has excellent corrosion resistance since it is less susceptible to damage such as spalling of the coating on steel pipes used for the board , and has a minimal gray coating (a developed layer of Fe-Zn alloy exposed to the surface of the galvanized layer).

Contents of the invention

The above-mentioned problems can be solved by the following features of the present invention.

The pipeline of the snowmelting board of the present invention has a straight pipeline and a U-shaped curved section connecting the straight pipeline. The plate has a size of 300 mm to 5000 mm in parallel length of straight pipes and 100 mm to 4000 mm in vertical span of straight pipes. The pipe has a hot-dip galvanized (galvanized) layer or a highly corrosion-resistant galvanized layer formed only on its outer surface.

In the snow melting board, the gap between adjacent pipes of the straight pipe line may be 100-300mm.

In snowmelting boards, straight lines and curved sections can be made from one long tube.

In the snow-melting board, the pipes of the snow-melting board may be steel pipes with a silicon content of less than 0.05 wt%.

In the snow melting board, the pipe may be a steel pipe with a silicon content of not less than 0.15 wt% and less than 0.20 wt%.

The pipe used in the snow melting board may have a straight pipe line and a U-shaped curved section, wherein the pipe has such an external shape that the parallel length of the straight pipe line is 300 mm to 5000 mm, and the vertical span of the straight pipe line is 100 mm to 4000 mm. The pipe can have a hot-dip galvanized coating or a highly corrosion-resistant galvanized coating only on the outer surface of the pipe. For straight pipelines, the gap between adjacent pipes is preferably 100-300mm. Also, it is preferable to make one long pipe for straight lines and curved sections. Furthermore, it is preferred for steel pipes to have a silicon content of less than 0.05 wt % or greater than 0.15 wt % but less than 0.20 wt %.

The present invention can provide low-cost snow-melting slabs that can be embedded in asphalt that requires corrosion resistance and can use antifreeze as a heating medium, so its industrial impact is significant.

Description of drawings

Fig. 1 is a structural diagram of the snow melting board of the present invention.

Detailed ways

Figure 1 shows an embodiment of the snowmelting board of the present invention. The pipes 5 used in the snowmelting board 1 of the present invention have straight lines and U-shaped bends. In order to facilitate operation in the process of transportation and placement, the size of the plate is set so that the parallel length 3 of the straight pipeline is 300 mm to 5000 mm, and the vertical span 2 of the straight pipeline is 100 mm to 4000 mm. In addition, the pipe 5 used in the snowmelting board 1 of the present invention has a hot-dip galvanized layer only on the outer surface, and has no hot-dipped galvanized layer on its inner side. This produces excellent corrosion resistance even when embedded in asphalt into which water containing a deicing agent has permeated, and enables the use of antifreeze as a heating medium. According to the length of the road, the required number of snow melting boards are connected together for use.

In Fig. 1, the gap 4 between adjacent pipes of the straight pipeline is wider than 300mm, which will lead to insufficient snow melting and insufficient antifreeze effect on roads and bridges. On the contrary, a gap between adjacent pipes of a straight pipeline narrower than 100mm may cause a temperature drop of the heating medium near the outlet, thereby partially causing snow melting and insufficient antifreezing effect. Therefore, for straight pipelines, the gap between adjacent pipes is preferably in the range of 100-300 mm.

For bending it is preferred to use a long tube without welds between the straight line and the bend. Doing so inhibits corrosion of the weld. The use of long pipes can also greatly reduce the number of joints between pipes, thereby reducing engineering costs.

The galvanized layer on the outer surface of the pipe 5 used in the snowmelting board 1 of the present invention is a coating that is not easily damaged such as peeling off even at curved sections. Whether the pipe is made into a plate by welding straight steel pipes and U-shaped steel pipes together or by plugging the two ends and bending long steel pipes into a zigzag pattern by hot-dip galvanizing, it can be made only on the outer surface Sheets with a galvanized coating that do not suffer damage such as spalling even at bends.

Thus, in the case where the pipe 5 constituting the snowmelting board 1 of the present invention is made by bending a long steel pipe into a zigzag pattern, there is an advantage that there is no damage such as spalling of the galvanized coating or traces on the bent section of electroplating repair. Also, in the case of welding straight steel pipes and steel pipes bent into a U-shape into a plate shape, there is an advantage in repairing traces of welded portions of steel pipes without plating.

The electroplating layer of the outer surface of the pipe used in the snowmelting board of the present invention can be electroplated by a general hot-dip galvanizing method. As an electroplating layer, highly corrosion-resistant hot-dip galvanizing including 2-19% aluminum, 1-10% magnesium and 0.01-2% silicon (the total content of aluminum and magnesium not exceeding 20%) can also be used. This highly corrosion-resistant hot-dip galvanizing is used for a galvanized steel sheet sold under the trade name "SuperDyma (registered trademark)" by Nippon Steel Corporation.

Next, chemical composition conditions of a steel pipe used as a snow-melting board pipe are preferable.

There is a relationship between the silicon content in the steel pipe, the gray coating, and the amount of zinc deposited when the galvanized layer is formed on the outer surface of the steel pipe. The gray coating and the amount of deposited zinc reached a maximum at a silicon content of 0.07%. When the silicon content of the steel pipe is less than 0.05wt% or not less than 0.15wt%, the interdiffusion of iron and zinc is suppressed, the gray coating is improved, and the economic value is enhanced. However, a silicon content exceeding 0.20 wt% can cause welding cracks due to silicon oxide residues at joints between tubes. Therefore, the silicon content of the steel is preferably less than 0.05 wt%, or not less than 0.15 wt% and not more than 0.20 wt%.

Example

The snow melting board as an example was manufactured using long (about 50,000 mm) and short (about 2,500 mm) length carbon-steel pipes conforming to JISG3452, having an outer diameter of 21.7 mm and a wall thickness of 2.8 mm. The straight lines of the snowmelting board had a parallel length of 2,500 mm, a vertical span of 2,500 mm, and a gap between adjacent straight lines of 200 mm. The panels were then embedded in the road to evaluate their performance. Steel pipes with different silicon contents were used for the examples of the present invention and the comparative examples, the former tubes were galvanized only on the outer surface, and the latter tubes were galvanized on the inner and outer surfaces.

Table 1 lists the characteristics, manufacturing conditions, and evaluation results of the tubes of the plates.

In order to evaluate the state of flaking/corrosion of the plating, snow-melting panels were manufactured and the galvanizing of the plate piping was observed for the flaking/corroding state after running water containing antifreeze through the plate piping for about one year. In Examples 1 to 4 of the present invention, only the outer surface of the pipe was galvanized, so there was no peeling of the galvanized layer on the inner side, and no partial corrosion was observed at all. However, in Comparative Examples 1 to 4 in which both the inner and outer surfaces were galvanized, peeling of the galvanized layer inside the tube and partial corrosion were observed.

The gray coating was evaluated by hot dipping the galvanized pipe in each example and observing if there was any consumption of the plate. In a preferred embodiment of the invention, there is appreciably no plate consumption for steels with a silicon content of less than 0.05wt% or not less than 0.15wt% and not more than 0.20wt%. A small amount of gray coating was observed in the cases where the silicon content was 0.05 wt % or more and less than 0.15 wt % (inventive example 1 and comparative example 2).

Embodiments 1 to 4 of the present invention use long pipes, and since the galvanizing is only applied to the outer surface of the pipes, the consumption of galvanized materials and engineering costs are low. On the contrary, in Comparative Example 3 in which a long pipe is also used, the consumption of galvanized material and engineering cost can only be included in the middle, because the inner and outer surfaces of the pipe are galvanized. In Comparative Examples 1, 2, and 4 in which short pipes were used, consumption of galvanizing materials and construction costs were evaluated to be high.

Table 1

^* Outside the preferred scope of the present invention

1) Tube length: long tube (the whole length of one board) about 50,000mm

    Short pipe (parallel length of straight pipe line) about 2,500mm

While preferred embodiments of the invention have been described and illustrated, it should be understood that these are exemplary of the invention only and are not to be considered limiting. Additions, deletions, substitutions and other modifications can be made without departing from the spirit or intent of the present invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims (8)

1. A snow melting board, comprising: a pipe comprising a straight line and a U-shaped bend connecting said straight line; A hot-dip galvanized coating formed only on the outer surface of said pipe, wherein The plate has a size of 300-5000mm in parallel length of the straight pipeline and 100-4000mm in vertical span of the straight pipeline, and the pipe is made of steel pipe with a silicon content of less than 0.05wt%. 2. The snowmelting board according to claim 1, wherein the gap between adjacent pipes of the straight pipe line is 100-300 mm. 3. The snowmelting board according to claim 1, wherein the straight line and the curved section are made of one long pipe. 4. The snowmelting board according to claim 1, wherein said galvanized layer is a highly corrosion-resistant galvanized layer. 5. A snow melting board, comprising: a pipe comprising a straight line and a U-shaped bend connecting said straight line; A hot-dip galvanized coating formed only on the outer surface of said pipe, wherein The plate has a size of 300-5000mm parallel length of straight pipelines and 100-4000mm vertical span of straight pipelines, and the pipes are made of steel pipe with silicon content not less than 0.15wt% and not more than 0.20wt%. 6. The snowmelting board according to claim 5, wherein the gap between adjacent pipes of the straight pipe line is 100-300 mm. 7. The snowmelting board according to claim 5, wherein the straight line and the curved section are made of one long tube. 8. The snowmelting board according to claim 5, wherein said galvanized layer is a highly corrosion-resistant galvanized layer.

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