JPS625665B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a device for lining metal elbows with plastic powder. As is well known, a plastic fluid dipping method is known as a method for lining metal surfaces with plastic powder. In this method, a heated metal object is coated with synthetic resin powder, and the powder is fused to the metal surface to form a protective film. The present invention relates to an apparatus for lining the inner surface of a metal elbow using such a plastic fluid dipping method. [Conventional technology and its problems] Generally, when lining the inner surface of a metal tube with plastic, the plastic film is applied to a uniform thickness and has a structure and shape that allow it to exhibit its full performance. There must be. However, with the conventional apparatus for lining the inner surface of a metal elbow with plastic, a lining film of uniform thickness could not be obtained because the object to be lined had a curved shape. In particular, when lining the inner surface of a straight metal tube, the tube is sprinkled while rotating, so synthetic resin powder is sprayed using centrifugal force. Since centrifugal force could not be obtained, on the contrary, a lining film of uniform thickness could not be obtained. Therefore, an apparatus has been proposed in which an elbow mounted on a rotary plate is filled with synthetic resin powder, the rotary plate is rotated, and the elbow is reversed to line the inside of the elbow (Japanese Patent Publication No. 54-44019). However, with this proposal, there was a risk that the thickness of the lining film would differ between the part where the powder was stored and the other part. [Means for Solving the Problems] The present invention was created in order to eliminate such inconveniences, and the fluidizing tank of the plastic fluidizing immersion device is fixed in a relatively large-diameter metal elbow. To provide a device for lining the inner surface of an elbow with plastic by scattering synthetic resin powder from a fluidized tank while rotating the elbow around the center of its radius of curvature. DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained in detail below with reference to embodiments shown in the accompanying drawings. FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a diagram showing one operating state. In these illustrations, a horizontal shaft 4 fixed with a bearing 3 is driven from a drive device 1 via a gear 2 (or roller chain). A rotary disk 5 is fixed to the end of the horizontal shaft 4 and rotated by a drive device 1. A steel elbow 6 is detachably fixed to the front surface of the rotary disk 5 by fixing means 14. The elbow 6
When fixing, the center O of the radius R of the elbow 6 is fixed so as to be the center of rotation of the rotating disk 5. A fluidizing tank 9 of a plastic fluidizing immersion device is opposed to the front surface of the rotating disk 5 as shown in FIG.
The fluidization tank 9 has a radius R of the elbow 6 to be lined.
A support pipe 8 having a radius equal to that of the elbow 6 is connected to the pipe, and in order to use a support pipe 8 that matches the radius of the elbow 6 to be lined, a plurality of support pipes 8 are prepared and can be easily attached to and detached from the fluidization tank 9. It's like this.
The support tube 8 is supported by a support stand 15, and
It is connected to an air tank or blower (not shown). A contact plate 12 made of heat-resistant rubber is provided around the upper periphery of the fluidization tank 9, and the contact plate 12 separates the plastic fused portion from the unfused portion on the inner surface of the elbow 6. Moreover, since it is made of heat-resistant rubber, the fluidization tank 9 can be used regardless of the diameter of the elbow 6. A filter cloth 10 is placed in the lower stage of the fluidized tank 9.
are stretched, and polyethylene resin powder is accommodated on these filter cloths 10. Since this embodiment is configured as described above,
In the so-called first quadrant on the front surface of the rotating disk 5, there is a third
As shown in the figure, a prescribed elbow 6 with an auxiliary tube 7 attached
to fix. Next, when the rotary disk 5 is rotated in the direction of the arrow a in FIG. 3, the elbow 6 passes through the fixed fluidization tank 9, resulting in the state shown in FIG. 1. Next, air is supplied from the support tube 8 to operate the fluidized tank 9, and at the same time the rotary disk 5 is slowly rotated in the direction of the arrow b in FIG.
The polyethylene resin powder 11 inside is scattered and fused to the inner surface of the elbow 6, forming a lining. Note that the contact plate 12 prevents excess polyethylene resin powder from scattering or circulating to unfused areas, so that the uniformity of the lining is not impaired. Further, the polyethylene resin powder 11 fused to the inner surface of the elbow 6 and lost from the fluidization tank 9 is replenished through a pipe 13 from above. In the above embodiments, the elbow is made of a steel pipe, the plastic powder 11 is made of polyethylene resin powder, and the elbow is explained as having an angle of 90 degrees. However, the present invention is not limited to these. It can also be applied to elbows of 45°, 60°, 90° to 120°, etc. In addition, the diameter of the elbow can be applied to all elbows from small to large diameters, but it can also be applied to those with a diameter of 300 mm or more and up to 2 m, and is not limited to standard elbows, in short, any curved short pipe can be used. Test examples according to this example are shown in the table below.

[Table] Detailed examples of fluidized tank specifications in the above test examples are as follows. That is, (1) inner diameter φ530 mm, powder depth 200 mm (powder accommodation height before fluidization) (2) air pressure 0.5 Kg·f/cm ² , air flow rate 90 N./min. Further, the relationship among air pressure, powder height during fluidization, and surface shape is as follows.

〔Effect of the invention〕

The synthetic resin powder is scattered while moving the fluidized tank inside the elbow relative to the elbow, which is different from blowing resin powder through one opening of the elbow.
According to the present invention, a uniform plastic film can be formed on the inner surface of the elbow without creating a blind spot. In particular, since the movement is performed on the radius of the elbow, relative movement between the elbow and the fluidizing tank can be made continuous and smooth, and the amount of scattered synthetic resin powder can be the same at any location within the elbow. In addition, unlike the case where synthetic resin powder is introduced into the elbow using a pipe, the scattering distance from the synthetic resin powder scattering to the inner surface of the elbow is short, so that the synthetic resin Since there is no risk of the powder settling, a uniform plastic film can be formed.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a diagram showing one operating state. 5... Rotating disk, 6... Elbow, 8... Support tube, 9... Fluidization tank, 11... Polyethylene resin powder, R... Radius, O... Center.

Claims (1)

[Claims] 1. An elbow support device for removably fixing a heated metal elbow to be lined; a fluidization tank for storing synthetic resin powder supported by a curved support tube for air feeding; Elbow lining device. 2. According to claim 1, the metal elbow to be lined is removably fixed to an elbow support device consisting of a rotating body whose center of rotation is the center of its radius, and the fluidizing tank is fixed on the front surface of the rotating body. The described metal elbow lining device.