JPH0731264U - Shot blasting equipment for steel pipes - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the scattering of shots and to collect them. [Structure] Steel pipe P rotatably supported in the horizontal direction
A casing 2 that can be opened and closed to cover a part of the entire length of the casing, a shot projector 1 attached to the casing 2 toward the steel pipe P inside, and a shot that has fallen to the bottom of the casing. And a separator 7 and 9 that separates and eliminates small-diameter shots installed in two stages in this resupply path.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shot blasting device which is used as a ground treatment when coating a large diameter steel pipe used for a pipeline, a steel pipe pile, etc., and particularly, a shot suitable for performing these operations at a site where the steel pipe is used. Blast equipment

[0002]

[Prior art]

 When coating steel products, it is necessary to perform a shot blasting process in which small-diameter steel balls called shots are blown onto these objects to remove surface scales as a base treatment. It is stipulated in ISO etc. (For example, ISO 8501-1, preparation of steel material before construction of paint and related products (1988), etc.).

In the case of shot blasting performed in a factory at the stage of manufacturing steel strips, thick steel plates, steel pipes, etc., a stationary shot blasting device is used. As an example of the shot blasting treatment of steel pipes performed in a factory, the one described in Japanese Patent Laid-Open No. 59-120470 will be described with reference to FIG. 1a and 1b are shot blasting projectors, 2 is a casing (cabinet), 25 is an opening / closing door, 26 is an apron, P is a steel pipe, and T is a conveying roller.

At both ends of the casing 2, there are openings through which the steel pipe P comes in and out, and opening / closing doors 25a, 25b for closing the openings are provided. The opening / closing doors 25a, 25b are drive devices such as hoisting motors and support ropes. To move up and down to open and close the opening. Inside, apron 26a, 26b with a rubber sheet provided with an opening through which the steel pipe P can pass is attached to the round hole part of the thin plate with a slightly larger diameter than the outer diameter of the steel pipe P. Has been installed. Further, two shot blast projectors 1a and 1b are installed below the height at which the steel pipe P passes and are opposed to each other so as to project obliquely upward with respect to the traveling direction.

Since this steel pipe shot blasting apparatus is configured as described above, when the steel pipe P tries to enter the casing 2 from the right side of the drawing, the right opening / closing door 25a opens, and the steel pipe P moves to the casing. When the gun 1a passes through the opening of the apron 26a in 2 and reaches the projection area of the gun 1a, the gun 1a sharpens the surface of the steel pipe P, but the projection direction of the gun 1a is Since it is diagonally upward (forward), the shot does not enter the inner surface of the steel pipe from the opening at the tip of the steel pipe P 1. Similarly, when the steel pipe P is about to go out of the casing 2, only the gun 1b operates and projects obliquely upward (rearward) with respect to the traveling direction. Therefore, a shot is made from the opening at the rear end of the steel pipe P. Does not invade inside.

As described above, in the shot blasting device in which the steel pipe P of a finite length intermittently moves in and out of the casing 2, the shot is scattered out of the system through the opening at the front and rear ends of the steel pipe P or the opening in the casing 2. Preventing this is an important issue for environmental protection and cost management. By the way, when painting large-diameter steel pipes immediately before use at the site of driving large-diameter steel pipe piles or laying pipelines, conventionally, a dedicated shot blasting device was not installed, and the steel pipe was used as a turning roller. It was usual to use a hand-held shotgun while placing it and slowly rotating and moving it, and performing shot blast processing manually by the operator.

In such a manual shot blasting process, 1) a shot is a steel ball having a diameter of about 1 mm, and when the shot is blown by a gun, the shot shot bounces back to the worker and is extremely dangerous work. Therefore, it is necessary to wear a protective face and protective clothing, and continuous work is difficult depending on the region and season, which reduces work efficiency. 2) Due to manual work, it is inevitable that uniform spraying will not be possible and that the processing conditions will be uneven. 3) Since it is difficult to collect the shots that have been sprayed, the processing cost is high. There were problems such as these, and improvements were desired.

[0008]

[Problems to be solved by the device]

 SUMMARY OF THE INVENTION It is an object of the present invention to provide a shot blasting device having a simple structure that solves the above problems and is safe, high in quality, and low in cost.

[0009]

[Means for Solving the Problems]

 The present invention has a casing that can be opened and closed to cover a part of the length of a steel pipe that is rotatably supported in the horizontal direction over the entire circumference, and a shot projection attached to the casing toward the steel pipe inside. Machine, a shot collecting means for collecting shots that have fallen to the bottom of the casing and re-supplying them to the projector, and a separator that separates and eliminates small-diameter shots installed in two stages in this re-supply path. This is a shot blasting machine for steel pipes.

[0010]

[Work]

 First, in the present invention, the steel pipes to be processed are hung by a crane or the like in the casing of the shot blasting equipment and sprayed, so that the casing opening is blocked by the steel pipe itself. It is possible to complete the process from the start with no interruption, and there is no problem of the above-mentioned shot scattering outside the system.

Further, in the shot blasting device of the present invention, only the portion of the steel pipe surface to be shot blasted is surrounded by the casing, and the shot is blown inside the casing. Therefore, there is a risk that the shot bounces to the operator. No, and the collection of shots is easy. Further, since the projector is attached to this casing, not only can uniform treatment be performed by controlling the rotation and feed of the steel pipe, but also the degree of shot blast can be adjusted arbitrarily.

[0012]

Embodiment An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of this shot blasting apparatus, and FIG. 2 is a side view. The steel pipe P is placed on a turning roller with a traveling mechanism (not shown), and is rotatably supported while traveling in the axial direction.

1 is a projector, 2 is a box-shaped casing, there are openings through which the steel pipe P penetrates on both sides of the casing 2, and side seals 22 are provided in the gaps with the steel pipe. The casing 2 can be opened and closed by a hinge 23 on the back surface, and a steel pipe can be suspended or taken out with the upper lid opened. The projector 1 is attached to the casing 2 toward the cylindrical surface of the steel pipe P. As a projector for shots, one using compressed air, one rotating an impeller, and the like are known. In this embodiment, an impeller system is adopted to avoid moisture in the air. It is installed at a distance of about 0.8 to 1.0 m from the cylindrical surface of the steel pipe P, and a shot of 120 to 150 kg per minute can be projected for a width of about 0.7 m.

When performing shot blasting, when the upper lid of the casing 2 is opened and the steel pipe P is hung inside the casing 2, the steel pipe P is placed on the turning roller waiting outside the casing 2, The casing 2 has a shape that covers a part of the length of the steel pipe P over the entire circumference. The turning roller is run in the longitudinal direction of the steel pipe P, and the shot blasting process is started after adjusting the left end portion of the range where the shot blasting process is to be performed so that it is the front of the projector 1, and the steel pipe P is slowly rotated. While proceeding to the left in Fig. 1, the projection is stopped when the right end of the range where shot blasting is to be performed is the front of the projector 1.

With this arrangement, the openings on both sides of the casing 2 are always closed by the steel pipes P, and the openings at both ends of the steel pipe P do not come into the casing 2. Never dissipate. The bottom plate 21 of the casing 2 is inclined in one direction, and the shots dropped on the bottom plate 21 are collected by the shot collecting means 4 through the connected chute 24 and are circulated and used.

The recovery shot conveyed upward by the shot recovery means 4 such as a bucket conveyor is loaded into the hopper 8 through the loading port 41. The path between the input port 41 and the hopper 8 is the primary separator 7, and the blower 5 is opened on one side surface and the collector 6 is opened on the side opposite to the side surface, and it is worn or crushed by repeated use. The shots having a small diameter are sorted by specific gravity while falling through the primary separator 7, are blown away without falling to the hopper, are captured by the collector 6 and are discharged to the outside of the system.

Below the hopper 8, a lattice type secondary separator 9 is further provided, and only shots of a predetermined size or more are supplied to the projector 1 below and used for shot blasting. Fine powder such as scale that is separated from the surface of the steel pipe by the shot blasting process and is floating in the casing 2 is processed by the dust collector 10. In addition, dust, scale powder, etc. remaining or adhering to the steel pipe surface is removed by the cleaning means 3 such as a brush unit attached to the outlet side of the casing 2 in contact with the steel pipe surface. Be clean.

Since the steel pipe itself is rotating, the brush unit may be a fixed type, but a cleaning unit that brings the nylon brush or the like into contact with the steel pipe surface while rotating has a remarkable cleaning effect. When shot blasting was performed on a steel pipe having a diameter of 1000 mm and a length of 15,000 mm, which was obtained by mixing shots of # 120 and # 70 in a ratio of 1: 1 by the shot blasting apparatus of this embodiment, the finished state was B Sa- Near white equivalent to 3 was good, and the shot recovery rate was almost 100%.

Since the projector 1 is mounted so that the distance in the projection direction can be adjusted, the distance can be adjusted by observing the effect of shot blasting, or the side seal 22 can be replaced to replace the projection. By changing the mounting position of the machine 1, it is possible to handle various types of steel pipes P having different sizes. It should be noted that the position adjustment of the projector 1, such as a flexible structure, is performed not only in the connecting portion between the projector 1 and the casing 2 but also in any of the paths from the input port 41 on the outlet side of the shot collecting means 4 to the projector 1. It is necessary to have a structure that can support

[0020]

[Effect of device]

 According to the present invention, 1) the shot is not scattered outside the casing, and the environment is kept good. 2) Since the worker does not have to hold the shotgun, safety and productivity are improved, and the processing situation is stable and the quality is improved. 3) Costs are reduced because shots are collected and used repeatedly. 4) Since shots with a small diameter are eliminated, processing efficiency is improved. Has excellent effects such as.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a side view showing an embodiment of the present invention.

FIG. 3 is a sectional view in the front direction showing a conventional technology example.

[Explanation of symbols]

 1 Projector 2 Casing 21 Bottom plate 22 Side seal 23 Hinge 24 Chute 25 Open / close door 26 Apron 3 Cleaning means 4 Shot collecting means 41 Input port 5 Blower 6 Collector 7 Primary separator 8 Hopper 9 Secondary separator 10 Dust collector P Steel tube T Transport roller

Claims (3)

[Scope of utility model registration request] 1. A casing (2) which can be opened and closed so as to cover a part of the length of a steel pipe (P) which is rotatably in a horizontal direction in the entire lengthwise direction, and a steel pipe (P) inside the casing. A shot projector (1) attached to the casing (2), a shot collecting means (4) for collecting shots dropped at the bottom of the casing (2) and re-supplying them to the projector (1), and Separator (7,
9) A shot blasting device for steel pipe, which is composed of 2. The shot blasting device for steel pipes according to claim 1, wherein the projector (1) is attached so that the distance to the casing (2) can be adjusted. 3. A steel pipe (P) is provided outside the casing (2).
The shot blasting apparatus for steel pipes according to claim 1, wherein cleaning means (3) is provided in contact with the surface.