| 摘要 |
1,204,632. Coating apparatus. AQUITAINEORGANICO. 27 Jan., 1969 [2 Feb., 1968], No. 4463/69. Heading B2L. Apparatus for coating a tube internally and externally comprises means for heating the tube, hollow means for gripping the ends of the tube, means for fluidising and circulating coating powder, flexible pipes connecting said circulating means to said hollow gripping means, lifting and transport means for said gripping means, and a bath of fluidised powder, the heated tube being coated internally by the passage therethrough of fluidised powder and externally by introducing the tube into said bath. A furnace 1 is divided by internal partitions 2, 3 into compartments 4a, 4b, 4c which may be kept at different temperatures. Openings 5, 6 in the end walls are interconnected by an opening in the front wall, the latter opening being closed by collapsible plates 7. A. conveyor 8 within the furnace receives tubes 9 via a shoot 10 provided in the back wall. Each end wall supports a track 28a positioned above the respective openings 5, 6. A track 28b is secured to the piston of a fluid pressure jack 29 and may be thereby either raised to a position of alignment with an associated track 28a, or lowered. A carriage 18, traversable along the aligned tracks 28a, 28b by a motor 27, is provided with tracks 17. Carriages 13, 14, traversable along the latter by respective jacks 15, 16, support respective tube-gripping members 11, 12, each of which journals a hollow shaft provided at its inner end with tube-gripping jaws actuated by a jack, the outer ends of said shafts being connected to respective flexible pipes 21 and 25. The hollow shaft in member 12 is rotatable by a motor 19 mounted on carriage 14. Pipe 21 is connected via a valve 22 to a receptacle 20 containing coating powder. Pipe 25 is connected via a cyclone separator 24 to a vacuum pump 23. In operation, tracks 28a, 28b are initially aligned with carriages 18 engaging tracks 28a to align members 11, 12 with openings 5, 6, and carriages 13, 14 are retracted. Carriages 13, 14 are then advanced, whereby members 11, 12 engage and grip the ends of a heated tube 9 supported on conveyor 8 when the latter is operated to transfer the weight of tube 9 to members 11, 12. Motor 19 is then started for rotating tube 9, pump 23 is started, valve 22 is opened for a predetermined interval whereby coating powder is drawn through tube 9, and pump 23 is stopped after a further predetermined interval whereby excess powder is discharged by separator 24 into a receptacle 26. Carriages 18 are then moved into engagement with tracks 28b to position the internally-coated tube above a tank 30, and tracks 28b are lowered to immerse the tube for a predetermined period in a bed of fluidised powder mounted in tank 30 for coating the exterior of the tube. The latter is then raised and is finally freed from the members 11, 12 when the coating has sufficiently hardened. |
