JP4241503B2 - Dust collector for ERW steel pipe production line - Google Patents

Description

  The present invention relates to a dust collector of an ERW steel pipe production line, and in particular, a steel strip to be plated is formed into a cylindrical shape by a forming roll, and both end portions in the width direction where the steel strip is abutted are formed in an induction heater. In addition, the present invention relates to a dust collecting device that collects fumes generated from plated metal when the tube is joined by a joining device constituted by a squeeze roll to improve the surrounding environment.

  As shown in FIG. 3, the ERW steel pipe is rewound the coiled steel strip 1 as a raw material by an uncoiler, and in a state in which the steel strip 1 is run, the forming roll group 2 is arranged in multiple stages in the traveling direction. After continuously forming into a cylindrical shape, the end portions in the width direction of the abutted steel strips are welded with a joining device including an induction heater 3 and a squeeze roll 4 to form a temporary tube 5. Then, a bead (not shown, but a bulge of the welded material that is formed in the longitudinal direction of the tube) formed on the inner and outer surfaces of the joining portion (referred to as a seam portion) is removed by the cutting means 6, and the ultrasonic flaw detector 7. After inspection with slag, annealing with seam-anilar annealing device 8 and water cooling with water injection nozzle 9, the dimensions of the tube are adjusted with a drawing mill 10 such as a stretch reducer or sizer to make a product. The

  By the way, in manufacture of this ERW steel pipe, the steel strip 1 which carried out the hot dip galvanizing to the raw material is utilized, and a to-be-plated ERW steel pipe may be manufactured. In that case, the steel strip to which the hot dip galvanization has been applied (hereinafter referred to as the steel strip 1 to be plated) is heated to about 1500 ° C. by the induction heater 3, so in the plated metal having a boiling point lower than that temperature. Zinc is scattered in the form of fume and dust, deteriorating the surrounding environment. Since this state does not meet recent work environment improvement requirements, improvement is eagerly desired.

In addition, the molten metal is sprayed on the trace after the bead cutting through a nozzle to repair the plating layer. In that case, a gas seal device has been developed to surround the joining device, the vicinity thereof, and the cutting means with a hood, and maintain the enclosed portion in a non-oxidizing atmosphere (see, for example, Patent Document 1). However, the gas seal device is a system in which a non-oxidizing gas is blown into the hood, which is not preferable for dust collection, and has a problem that the structure is complicated and maintenance is difficult.
JP-A 62-109958

  In view of such circumstances, an object of the present invention is to provide a dust collector for an ERW steel pipe production line that makes the surrounding environment of an induction heater and a squeeze roll better than before.

  The inventor has intensively studied to achieve the above object, and the results have been embodied in the present invention.

  That is, the present invention surrounds an induction heater and a squeeze roll that are installed in an ERW pipe manufacturing line made of a metal-plated steel strip and pass through the steel strip that is formed into a cylindrical shape by a forming roll. A box-type hood that cuts through the duct, and communicates with the box-type hood via a duct, sucks and decompresses the atmosphere inside the hood, and an exhaust that is provided in the middle of the duct and passes through the duct. And a collecting means for removing and collecting dust, the steel strip formed in a cylindrical shape on the upstream side wall surface of the box-shaped hood, and the width direction in which the steel band is abutted on the downstream side wall surface Through holes that pass through the tubular bodies after both ends are joined are opened, and each of the through holes can be expanded and contracted according to the steel strip formed into the cylindrical shape and the outer diameter of the joined tubular body. Attaching a seal plate DOO is a dust collector of the electric resistance welded steel pipe production line according to claim.

  ADVANTAGE OF THE INVENTION According to this invention, scattering of the fume of metal plating and dust from the circumference | surroundings of the induction heater and squeeze roll of an ERW steel pipe manufacturing line can be suppressed now. As a result, the surrounding environment of the induction heater and squeeze roll becomes better than before, and the work environment problem is solved.

  Hereinafter, the best embodiment of the present invention will be described based on the background of the invention.

  In order to improve the surrounding environment of the induction heater 3 and the squeeze roll 4 in the ERW steel pipe production line shown in FIG. 3, it is natural to install a dust collector. In general, a dust collector is a vacuum cleaner that draws and depressurizes the atmosphere inside the hood through various types of dust collection hoods that surround the place where contaminants such as dust are generated, a duct communicating with the dust collection hood, and the duct. The exhaust gas is drawn into the hood, and is composed of an exhaust fan that leads to a recovery device described later and a recovery means that removes and recovers the contaminant from the exhaust gas passing through the duct.

  Therefore, the inventor, as the dust collecting hood, shown in FIG. 1, the induction heater 3 is interposed between the fin pass roll 13 which is the final stage of the forming roll group 2 and the cutting means 6 for the inner and outer surface beads. The box-shaped hood 11 that surrounds the entire squeeze roll 4 and blocks outside air is employed. Thereby, even if zinc fumes and dust are generated from the cylindrical body passing through the induction heater 3 and the squeeze roll 4, they are prevented from being scattered to other places. The material of the box-shaped hood 11 can be steel, heat-resistant plastic resin, or the like. The duct 12 connected to the box-type hood 11 may be made of the same material. Furthermore, as a wind exhauster (not shown) that sucks and decompresses the atmosphere inside the box-type hood 11 through the duct 12, either a so-called “suction method” or “push-in method” may be used. In the case where the exhaust gas passing through the duct 12 is disposed downstream of the recovery means 14 for removing and recovering contaminants such as zinc fume and dust from the exhaust passing through the duct 12, the “suction method” is adopted. When it is arranged between the collection means 14 and the box-type hood 11, a “push-in method” is adopted. In the present invention, a negative pressure of about 5 to 10 mm water column is sufficient as the atmospheric pressure in the box hood 11 generated by the exhaust fan. In addition, well-known means such as a cyclone, a bag filter, a scrubber, etc. can be used for the collecting means 14.

  The dust collector of the ERW steel pipe production line according to the present invention is composed of the box-shaped hood 11, the duct 12, the air exhauster, and the pollutant collecting means 14 described above. The box-shaped hood 11 is made to run at a constant speed on a steel strip formed into a steel strip (both ends of the steel strip abutted against each other are joined to each other with an induction heater 3 and a squeeze roll 4). In order to pass through the inside, special consideration is required for the upstream side wall surface 15 and the downstream side wall surface 16 of the box-shaped hood 11. That is, the upstream side wall surface is formed so that the cylindrical steel strip or the like can pass through an appropriate gap (for example, about 10 mm) without contacting the upstream side wall surface 15 and the downstream side wall surface 16 of the box-shaped hood 11. 15 and the downstream side wall surface 16 must be provided with through holes. When contact occurs, the plated metal is peeled off and dust is generated, and the plating quality on the surface of the tube body after joining is deteriorated. If there is no appropriate gap, the atmosphere in the box-type hood 11 is desired. This is because the pressure cannot be adjusted. In addition, there are circumstances that the outer diameters of the cylindrical steel strip and the tubular body 5 vary depending on the product order.

  Therefore, the inventor has intensively studied the through hole, and shows the steel strip formed in a cylindrical shape on the upstream side wall surface 15 of the box-shaped hood 11 and the downstream side wall surface 16 shown in FIG. As described above, the through-hole 23 through which the tubular body after joining the both ends in the width direction in which the steel strips are joined passes is opened with a diameter larger than the maximum outer diameter of the ERW steel pipe standard to be manufactured. At the same time, each of the through holes 23 is provided with a seal plate 17 that can be expanded and contracted in accordance with the steel strip formed into the cylindrical shape and the outer diameter of the joined pipe body.

  As the seal plate 17 which can be expanded and contracted, those having various mechanisms can be used, but those equivalent to the iris diaphragm system of the camera are preferable. That is, the crescent-shaped steel plates 18 are combined in a ring shape, and the projections 19 attached to the steel plates 18 are moved by a driving means (not shown) along the grooves 21 provided on the other steel plates 20 stacked on them. Thus, a concentric or polygonal center hole 22 is formed at the center. Thereby, even if the outer diameter of the steel strip formed into a cylindrical shape and the joined pipe body is changed, the outer circumference of the pipe body etc. is in contact with the upstream side wall face 15 and the downstream side wall face 16 of the box-shaped hood 11. And a gap having an appropriate size can be formed from the outer periphery.

  The size shown in Table 1 in the production line for the ERW steel pipe shown in FIG. 3, using a medium carbon (C: containing 0.15 mass%) steel galvanized steel strip as the metal plated steel strip. An electric resistance welded steel pipe was manufactured. At that time, the dust collecting apparatus according to the present invention was adopted, and the result was observed in the surrounding environment of the induction heater 3 and the squeeze roll 4 and the amount of collected dust (kg / day) was measured. evaluated. In addition, as for the observation condition of the surrounding environment of Table 1, (circle) mark means that it is favorable and x mark means defect.

  From Table 1, it is clear that the dust collector of the ERW steel pipe production line according to the present invention can sufficiently collect dust and is effective in improving the surrounding environment.

It is a schematic diagram explaining the dust collector of the ERW steel pipe manufacturing line which concerns on this invention. It is a figure explaining the sealing plate of the through-hole provided in the box-type hood which concerns on this invention. It is a schematic diagram which shows the production line of an electric resistance steel pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coiled steel strip 2 Forming roll group 3 Induction heater 4 Squeeze roll 5 Tubing body 6 Bead cutting means 7 Ultrasonic flaw detector 8 Post-anilar 9 Water injection nozzle 10 Drawing mill 11 Box type hood 12 Duct 13 Fin pass roll 14 Recovery means 15 Upstream side wall surface 16 Downstream side wall surface 17 Seal plate 18 Crescent steel plate 19 Projection 20 Another steel plate 21 Groove 22 Concentric or polygonal center hole 23 Through hole 24 Breakdown roll

Claims (1)

  Box-shaped hood that is installed in an ERW steel pipe production line made of metal-plated steel strip and surrounds the induction heater and squeeze roll through which the steel strip formed into a cylindrical shape by a forming roll passes and blocks the outside air And an exhaust fan that sucks and depressurizes the atmosphere inside the hood through a duct, and removes and collects fumes and dust from the exhaust that is provided in the middle of the duct and passes through the duct. A steel strip formed in a cylindrical shape on the upstream side wall surface of the box-type hood, and the downstream side wall surface after joining both ends in the width direction where the steel band abuts each other. A through-hole that passes through the tubular body is opened, and each of the through-holes is provided with a steel strip formed into a cylindrical shape and a seal plate that can be expanded and contracted according to the outer diameter of the joined tubular body. Electric sewing characterized by Dust collector of the tube production line.

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